[Independence of special forms of chloeophyll a and chlorophyll holochromes]. Zea mays L. seedlings were cultivated for 10 days with submission to 4 s illumination periods interspersed with dark periods varying in length from 30 min to 6 h depending on the lot analyzed.  The results show that, for the case in which the dark periods were shorter than 1 h, the relative proportions of different spectroscopic chlorophyll forms (maxima at 662, 670, 677.5, and 684 nm) were constant.  For longer durations of darkness between illuminations, the relative proportion of the form Da670 increases, while that of Ca684 diminishes with the length of darkness; to a lesser extent, the relative proportion of Ca662 increases and a form Ca692 disappears.  A scheme is proposed to explain the evolution of the relative proportions of the different spectral forms.  The different chlorophyll holochromes present in the chloroplasts were also analysed.  If the dark period was longer than 1 h, chlorophyll was associated with peptide chains of molecular weights 21 000 and 29 000.  If the dark period was shorter than 1 h chlorophyll was associated with four peptide chains of molecular weights 21 000, 25 000, 29 000 and 70 000.  The results taken together demonstrate that a given spectral chlorophyll a form cannot be associated with a definite chlorophyll holochrome.


Silicomolybdate and silicotungstate mediated dichlorophenyldimethylurea-insensitive photosystem II reaction: electron flow, chlorophyll a fluorescence and delayed light emission changes. We have investigated the possible role of silicomolybdate and silicotungstate as acceptors of electrons in chloroplasts directly from Q, the primary electron acceptor of Photosystem II.  Our data show: 1. Either of these compounds can accept electrons directly from Q in a 3-(3', 4'-dichlorophenyl)-1, 1-dimethylurea (DCMU)-insensitive electron transport; however, the DCMU insensitivity is only short-lived, so initial rates must be used exclusively.  2. High concentrations of these silico compounds act as direct chemical quenchers of chlorophyll a fluorescence, but lower concentrations which also mediate O2 evolution affect only the variable component of fluorescence in a manner suggestive of their electron-accepting capabilities.  3. Measurements of delayed light emission confirm the conclusions made from the fluorescence data.  Also, they show the role of Q in delayed light emission as hydroxylamine data of other investigations have shown the role of Z, the electron donor of Photosystem II.  4. Silico compounds appear to be acting as electron acceptors and not as simple membrane modifiers allowing other acceptors to support a DCMU-insensitive electron transport.


A large photoreactive particle from Chromatium vinosum chromatophores. Large photoreactive particles from Chromatium vinosum are obtained pure and in high yield by using a mixture of detergents at high ionic strength to dissociate the chromatophore membrane.  The particles contain all of the secondary electron acceptor of the chromatophores and about half of the cytochrome.  Their content of ubiquinone is greatly enridhed as compared with chromatophores.  Th individual particles have an estimated molecular weight of between 650,000 and 810,000.  Gel electrophoresis of the preparation in sodium dodecylsulfate shows polypeptides with molecular weights of 50-45,000, 30,000, 27,000, 22,000 and 12,000.  The 50-45,000 components are cytochromes.  The 30,000, 27,000 and 22,000 components may be analogous to the triad of polypeptides present in Rhodopseudomonas spheroides reaction centers.  The non-cytochrome components are partly soluble in chloroform/methanol.  Aggregates of particles appear in these preparations.  Electron microscopy of the aggregates demonstrates rectilinear lattices of isodiametric particles, 120 A in diameter.  These sheet-like structures are one unit thick and typically contain 9-16 members.  They appear to arise by aggregation during isolation but are probably similar to native aggregates apparent within chromatophores after treatment with detergents at low salt concentration.


A new site of bicarbonate effect in photosystem II of photosynthesis: evidence from chlorophyll fluorescence transients in spinach chloroplasts. Recent studies on oxygen evolution of corn chloroplast fragments in flashing light [Stemler, A., Babcock, G.T. and Govindjee (1974) Proc. Natl. Acad. Sci. 71, 4679-4683] have shown that the absence of bicarbonate ions increases the turnover time of the Photosystem II reaction center.  The rate limiting steps in Photosystem II turnover can be interpreted in terms of reactions either on the oxidizing (electron donor) or reducing (electron acceptor) side of the reaction center.  Experiments are reported here that suggest at least one site of bicarbonate action on the reducing side.  In Tris-washed spinach chloroplasts (incapable of O2 evolution), the chlorophyll a fluorescence transient in the presence of various artificial electron donors (hydroquinone, diphenylcarbazide, MnCl2 and NH2OH) and in the absence of bicarbonate ions shows a rapid initial rise; the addition of 10 mM NaHCO3 restores the transient to one characteristic of normal chloroplast.  Furthermore, the transients measured as a function of decreasing bicarbonate concentrations are qualitatively similar to those observed with increasing concentrations of 3-(3, 4-dichlorophenyl)-1, 1-dimethyl urea which imposes a block on the reducing side, rather than to transients observed with increasing concentrations of NH2OH or prolonged heat treatments, which impose a block on the oxidizing side.


The absence of an 8-desaturases in rat liver: a reevaluation of optional pathways for the metabolism of linoleic and linolenic acids. 11-[3- -14 C] Octadecenoic acid, 11,14-[1- -14C] nonadecadienoic acid, 11,14-[1- -14 C] eicosadienoic acid, 11,14-[1- -14 C] heneicosadienoic acid and 11,14,17-[3- -14 C] eicosatrienoic acid were fed and injected into tail veins of rats raised on balanced and fat-free diets. Analysis of the total liver lipids showed that 11-ated to 5,11,14-19:3; 11,14-20:2 was desaturated to 5,11,14-20:3; 11,14-21:2 was desaturated to 5,11,14-21:3 and 11,14,17-20:3 was desaturated to 5,11,14,17-20:4. In rats raised on balanced diets 11,14-19:2 and 11,14-21:2 were desaturated at very slow rates. The 11,14-20:2 and 11,14,17-20:3 were desaturated to 5,11,14-20:3 and 5,11,14,17-20:4but not as rapidly as in rats raised on fat-free diets. These findings strongly suggest that rat liver does not have a desaturase capable of introducing a double bond in the 8-position during polyunsaturated fatty acids biosynthesis. From these studies it can be concluded that linoleate is only converted to arachidonate via the following pathway:  9,12-18:2 yields 6,9,12-18:3 yields 8,11,14-20:3 yields 5,8,11,14-20:4. Linolenate is only metabolized as follows: 9,12,15-19:3 yields 6,9,12,15-18:4 yields 8,11,14,17-20:4yields 5,8,11,14,17-20:5 yields 7,10,13,16,19-22:5 yields 4,7,10,13,16,19-22:6. Optional pathways such as 9,12-18:2 yields 11,14-20:2 yields 8,11,14-20:3 yields etc. and 9,12,15-18:3 yields 11,14,17-20:3 yields 8,11,14,17-20:4 yields etc. are inoperative because 11,14-20:2 and 11,14,17-20:3 are probably not produced in vivo and if produced may well be converted to 9,12-18:2 and 9,12,15-19:3, respectively, by retroconversion.


Changes in phospholipids of ram spermatozoa during migration through the epididymis and possible origin of prostaglandin F2alpha in testicular and epididymal fluid. A study of the lipid composition of ram testicular and ejaculated spermatozoa was made in an attempt to resolve conflicting results in the literature. Testicular spermatozoa were found to contain more than double the amount of phospholipid present in ejaculated spermatozoa. Most phohpholipid components, including choline plasmalogen, decrease substantially in concentration during migration of the spermatozoa through the male reproductive tract. Phosphatidylserine, ethanolamine phosphoglycerides and cardiolipin components accounted for the greatest relative decreases in concentration, the former decreasing by approximately nine tenths. Of the phospholipid-bound fatty acids the most pronounced change occurs in palmitic during migration of spermatozoa through the reproductive tract. There is a net loss of approx. 500 mug of palmitic acid for every 10-9 spermatozoa. The loss of arachidonic acid was particularly interesting, and prompted a study of the prostaglandin content of testicular and epididymal fluids, since arachidonic acid can act as a precursor of prostaglandin. The concentration of prostaglandin F2alpha found in the testicular and epididymal fluid is considerably in excess of that found in venous plasma of the ram.


XLV. Metabolism of 3beta,7alpha-dihydroxy-5alpha-cholestanoic acid in the rat with a bile fistula. [25R]3beta,7alpha-Dihydroxy-[5alpha,6alpha- -3 H2]-5alpha-cholestanoic acid was prepared, purified and 0.34 mg was administered intraperitoneally as the potassium salt to each of three adult male rats with cannulated bile ducts. Bile collected in the first 24 h, containing 97% of the administered 3-H was hydrolysed and the free bile acids were separated by acetic acid partition chromatography. Of the chromatographed tritium 58% was associated with allochenodeoxycholic acid and 14% with its 3beta-isomer; only 5% of the 3-H was found in allocholic acid and 1% with the substrate or more polar unidentified materials. Thus, this dihydroxy-5alpha-cholestanoic acid is metabolized in the rat primarily to dihydroxy-5alpha-cholanic acids, comparable to the metabolism of 3alpha, 7alpha-dihydroxy-5beta-cholestanoic acid in man.


Blood group A active difucosyl glycolipid from hog gastric mucosa. A new difucosyl glycolipid exhibiting blood group A activity was isolated from water-soluble glycolipid fraction of hog gastric mucosa. The structure of this glycolipid was identified by partial acid hydrolysis, sequential degradation with specific glycosidases and methylation analysis, as: "see article".


Sialosphingolipids of sea urchin eggs and spermatozoa showing a characteristic composition for species and gamete. 1. Sialosphingolipids of four species of the Japanese sea urchin were compared. The composition of sialosphingolipids was characteristic for species and gamete. 2. It is suggested that sialosphingolipids may have a common carbohydrate backbone composed solely of hexoses and sialic acids.


Novel sialosphingolipids from spermatozoa of the sea urchin Anthocidaris crassispina. Sialosphingolipids obtained from spermatozoa of the sea urchin, Anthocidaris crassispina gave nine spots by thin-layer chromatography. Two of them were isolated by silicic acid column chromatography. The predominant one was proposed to be N-acetylneuraminyl (2 yields 8) N-acetylneuraminyl (2 yields 6) glucopyranosyl ceramide, and the second to be N-acetylneuraminyl (2 yields 6) glucopyranosyl ceramide.


Acute and chronic effects of ethanol on intestinal lipid metabolism. To assess the effects of ethanol on intestinal lipid metabolism, fatty acid oxidation and triacylglycerol synthesis were measured in intestinal slices incubated with ethanol. Ethanol, when used in concentrations likely to be achieved in the upper jejunum after moderate drinking, inhibited both palmitate and acetate oxidation, CO2 production and triacylglycerol synthesis, whereas it enhanced the esterification of fatty acid with ethanol. The concentrations required for the inhibitory effect were much higher than those needed to saturate enzyme systems known to participate in ethanol oxidation. In vivo administration of ethanol-containing diets produced persistent changes of the intestinal slices with respect to fatty acid oxidation and triacylglycerol synthesis. Acute intragastric administration of ethanol (3 g/kg) one hour prior to sacrifice, inhibited both processes in slices obtained from the jejunum, but not in those derived from the ileum. By contrast, chronic ethanol feeding increased the ability for fatty acid oxidation and triacylglycerol synthesis both in the jejunum and in the ileum. This stimulatory effect was associated with significant enhancement of palmitoyl-Co A synthetase activity, suggesting increased fatty acid activation. The inhibition by ethanol in high concentrations of intestinal fatty acid oxidation and triacylglycerol synthesis probably reflects epithelial cell damage; by contrast, prolonged administration of ethanol results in a persistent enhancement of lipid metabolism which may reflect the presence of a different cell population in the intestine.


Transfer of phosphatidylserine from liposomes or microsomes to mitochondria. Stimulation by a cell supernatant factor. Incubation of microsomes or sonicated dispersions of microsomal lipid containing (14-C)phosphatidylserine with rat liver mitochondria results in the transfer of radioactivity to the mitochondria. Transfer is time and temperature dependent and is stimulated by a factor in the 105 000 x g supernatant from liver homogenates. The supernatant factor is soluble at pH 5.1, stable to dialysis, and is inactivated by heating and by digestion with trypsin. Radioactivity accumulates in the mitochondria largley as phosphatidylethanolamine owing the activity of phosphatidylserine decarboxylase. Transfer to mitochondria, heat treated to inactivate the decarbosylase, is also promoted by the suppernatant factor, in which case the lipid appears to be incorporated into the mitochondrial membrane as unchanged phosphatidylserine.


Synthesis of prostaglandins by the rat renal papilla in vitro. Mechanism of stimulation by angiotensin II. 1. The biosynthesis of prostaglandins in the rat renal papilla was studied in a whole-cell preparation in vitro. Prostaglandins recovered from the incubation medium were identified by gas chromatography-mass spectrometry as prostaglandin E2 and prostaglandin F2alpha. Quantitative estimates of prostaglandin output were obtained by bioassay and confirmed by selected ion monitoring. 2. Prostaglandin biosynthesis was enhanced by exogenous arachidonic acid and also by triglyceride lipase, indicating that arachidonic acid released from papillary triglycerides is readily available for prostaglandin biosynthesis. 3. Angiotensin II (10--100 ng/ml) stimulated the biosynthesis of both prostaglandin E2 and prostaglandin F2alpha, thus increasing prostaglandin levels in both the incubation medium and the tissues. 4. The mechanism whereby angiotensin II stimulates prostaglandin biosynthesis was investigated using the isotope dilution technique. In the presence of [14-C]-arachidonic acid, angiotensin II stimulated the output of more prostaglandin that had a significantly lower specific activity than the controls. Angiotensin II therefore increased the availability of endogenous, non-labelled substrate for prostaglandin biosynthesis. This conclusion was supported by experiments in which enough arachidonic acid was added to make the kinetics of prostaglandin synthesis zero order. Under such conditions angiotensin II failed to cause any further increase in prostaglandin synthesis. 5. It is concluded that angiotensin II controls prostaglandin biosynthesis in the renal papilla by regulating the availability of free precursor. Possible mechanisms for increased levels of free arachidonic acid could be the activation of a tissue acyl hydrolase or decreased utilization of fatty acids.


Isolation and identification of prostaglandin E2 from gastrointestinal tract of shark Triakis scyllia. A prostaglandin was isolated from the gastrointestinal tract of the shark Triakis scyllia and identified as prostaglandin E2 by bioassay, thin-layer chromatography, gas-liquid chromatography, ultraviolet absorption spectrometry and mass spectrometry. The fatty acid composition of the tissue was also determined. The amount of eicosatetraenoic acid in this tissue was 17.2% of the total fatty acids, but the percentages of eicosatrienoic acid and eicospentaenoid acid were low.


Calcium-carbohydrate bridges composed of uncharged sugars. Structure of a hydrated calcium bromide complex of alpha-fucose. X-ray diffraction data were used to determine the crystal structure of a hydrated CaBr2 complex of alpha-fucose, a common terminal sugar of oligosaccharide chains on glycoproteins. Crystals of C6H12O5-CaBr2-3H2O are orthorhombic, space group P212121, with A equals 14.360(2), B equals 12.896(3), and C equals 8.043(1) A. Intensity data for 1442 independent reflections were measured with an automated diffractometer. A trial structure, obtained by the heavy-atom method, was refined by least-squares to R equals 0.052. Ca-2+ is chelated by a pair of hydroxyl groups from each of tow symmetry-related fucose molecules and is coordinated to three water molecules. Thus the structure consists of hydrated fucose-calcium-fucose bridges. The bridge geometry, which is dictated by the coordination requirements of Ca-2+, is like that of other calcium-carbohydrate complexes. Our results indicate that calcium-fucose interactions can provide an effective, sterospecific mechanism for cross-linking carbo hydrate chains. Similar calcium-carbohydrate bridges may be involved in a variety of Ca-2+-dependent agglutination and adhesion processes.


Voltage-dependent conductance induced by hemocyanin in black lipid films. When hemocyanin is added to a black lipid film, the conductance increases in discrete steps. For negative potentials the single step conductance is constant, but for positive potentials the step conductance appears to decrease as the potential increases. At high positive potentials the conductance fluctuates between several levels. These data suggest that, in lipid membranes, hemocyanin conducts ions through discrete channels. The voltage-dependent conductance observed at high levels of conductance seems to be a consequence of the properties of the conductance of the single channel.


Rapid preparative isolation of major erythrocyte membrane proteins using polyacrylamide gel electrophoresis in sodium dodecylsulfate. 1. We describe a simple method for preparative, sodium dodecylsulfate/polyacrylamide gel electrophoresis of the major proteins in human erythrocyte membranes. 2. The method is based on extraction of prestained proteins from gel slabs. Three different fluorescent dyes (o-phthalaldehyde, fluorescamine and 1-dimethyl-aminonaphthalene-5-sulfonylchloride) have been used for pretaining. The method allows separation of up to 75 mg membrane protein and isolation of mg quantities of all major erythrocyte ghost proteins, while preserving the high resolution of analytical polyacrylamide gel electrophoresis. 3. Yield depends on extraction conditions and the molecular weight of the proteins being eluted. It ranges from 43-48% for protein 1 (apparent mol. wt approx. 310000) and 72-78% for protein 3(apparent mol. wt 87 000-93 000) to 87-93% for protein 6 (apparent mol. wt 35 000). 4. The labile behaviour of the high molecular "spectrin" bands (bands 1 and 2) is described. Extraction at room temperature tends to split these proteins into products of lower molecular weight. In contrast, the minor protein components 2.1 and 2.2 tend to aggregate yielding components 1 and 2. 5. N-terminal amino acid analyses have been performed on proteins 1, 2, 3, 4A, 4B, 5 and 6. Each of these bands contains several N-terminals, most of which appear constant. Some additional N-terminal amino acids vary from one donor to the next.


Xeonon accumulation in the red blood cell. A process latered by suppressors of the membrane active transport function. Xenon passage across the erythrocyte membrane was investigated by performing several types of tests. The effects of some enzyme inhibitors (ouabain, NaF, dinitrophenol, low temperature), representing various modifications of the mentioned transport phenomenon, led to the conclusion of the existence of a strong correlation between the cellular energetic metabolism (and, hence, the energy supply for membrane processes) and the xenon accumulation into the erythrocyte. The experimental data obtained indicate that the xenon concentration in the cell water exceeds the concentration in the incubation solution by about 20%. The metabolic inhibitors practically equalise the xenon concentrations in the cell water and in the surrounding medium. The possible theoretical consequences of these facts are taken into account and analyzed.


Mechanism of the mutagenic action of hydroxylamine. VIII. Functional properties of the modified adenosine residues. The action of O-methylhydroxylamine in vitro upon some amber and rII ochre mutants of T4 phage leads to a considerable increase in the frequency of reversions and conversions of ochre and opal mutants presumably due to A yields G transitions. The transitions seem to be caused by modification of the adenine bases  of the genome to give N-6-methoxyadenine which has equivocal (A- and G-like) specificity. However, the functional activity of N-6-methoxyadenosine residues in the RNA polymerase system is low. We failed to detect any significant activity of these residues either as components of a template polyribonucleotide, or as nucleoside triphosphate precursors.


Isolation and purification of RNA polymerases from rye embryos. A procedure has been developed for the purification of soluble DNA-dependent RNA polymerase (EC 2.7.7.6) from rye embryos. The enzyme solubilized by high salt extraction with sonication and resolved by DEAE-cellulose chromatography yields two activities. Enzyme I eluted at 0.15 M (NN4)2SO4, was insensitive to alpha-amanitin and was extremely labile. Enzyme II eluted at 0.25 M (NH4)2SO4 was inhibited by alpha-amanitin. However, DEAE-Sephadex chromatography yields three DNA-dependent RNA polymerases. Enzyme I is resistant to amanitin, while II and III enzymes are inhibited by this poison. Partially purified on DEAE-cellulose, polymerase II was further purified by hydrophobic chromatography on an omega-aminobutyl-Sepharose column. After omega-aminobutyl-Sepharose chromatography, enzyme II was stable and was more active with denatured than with native DNA as template. The activity of purified RNA polymerase II is dependent on the DNA, Mn-2+ and Mg-2+ added and requires ATP, GTP, CTP and UTP for its maximum activity. Transcription is inhibited besides by alpha-amanitin, by chromomycin A3, daunomycin, ethidium bromide and actinomycin D. Rifampin and rifamycin SV do not inhibit the enzyme. Synthetic copolymers were also effective as templates.


Unique sequence DNA transcripts present in mature oocytes of Urechis caupo. DNA - DNA reannealing of sheared Urechis caupo DNA indicates that the genome is composed of two major repetitive sequence families. The repetitive sequence DNA families compose 8 and 7% of the DNA and are repeated in the genome on an average of 2.0 - 10-6 and 6.0 - 10-3 times, respectively. The unique sequence DNA composed a minimum of 75% of the genome and the rate of reannealing indicates a complexity of 2.6 - 10-8 nucleotide pairs per genome. Hybridization of isolated 3-H-labeled unique sequence DNA with an excess of unlabeled mature oocyte RNA provides a minimum estimate of the genetic diversity of the RNA present in the mature oocytes. The apparent saturation level of unique sequence DNA with RNA indicates that about 8.6% of the unique sequence DNA is expressed. Based on the fraction of the DNA that forms a stable hybrid and the complexity of the unique sequence DNA the RNA present in the mature oocyte is a complementary with 2.2 - 10-7 nucleotide pairs of unique sequence DNA.


A dissociation factor from embryos of Xenopus laevis. A dissociating factor has been extracted from the ribosomal KCl wash and from the cytosol of developing embryos of Xenopus laevis. No dissociating activity could be detected in the KCl wash of ribosomes from full grown oocytes and unfertilized eggs. As in bacteria, the acitivity of the dissociation factor seems to be correlated with the rate of protein synthesis suggesting a physiological role of the dissociation factor. The possibility that the dissociation factor might be one of the components which limits the rate of protein synthesis in the oocytes is discussed.


Attempts to detect Agrobacterium tumefaciens and bacteriophage PS8 DNA in crown gall tumors by DNA-DNA-filter hybridization. A systematic study of the DNA-DNA-filter reaction is presented which measures its ability to detect small amounts of simple DNA (bacterial or bacteriophage) in model mixtures of DNA immobilized on filters. Saturation curves show qualitatively that significant binding occurs when there is 10% Agrobacterium tumefaciens DNA on the filter but not 1%. PS8 bacteriophage DNA is detectable at a level of 0.1%. True saturation is not attained in the bacterial DNA reaction : radioactivity bound represents only 3% of the theoretical saturation value. The bacteriophage DNA reactions attain 15-30% of the expected saturation value. When crown gall tumor DNA filters were tested for the presence of A. tumefaciens or PS8 bacteriophage DNA by saturation reactions, an apparently significant amount of binding was observed compared with usual background levels for heterologous DNA filters. However thermal dissociation profiles revealed that no well-matched duplexes were formed. Normal tobacco callus DNA filters exhibited the same type of binding of labeled DNA to a similar extent (50-100% as much as tumor DNA filters). Both types of DNA-filters bound Bacillus subtilis and bacteriophage T4 DNA as efficiently as A. tumefaciens and PS8 DNA. The high non-specific background binding of labeled DNA by filters containing DNA isolated from plant tissue culture materials is ascribed to low single strand molecular weight of the filterbound DNA. This study provides no evidence for foreign DNA in crown gall tumors, and raises objections to the interpretation of the data of earlier investigators (Quetier, F., Huguet, T. and Guille, E. (1969) Biochem, Biophys. Res, Commun. 34, 128-133 and Srivastava, B.I.S. (1970) Life Sci. 9, 889-892) who claimed to detect A. tumefaciens DNA in crown gall tumors by DNA-DNA-filter hybridization.


Circular mitochondrial DNA from the avian malarial parasite Plasmodium lophurae. The avian malarial parasite, Plasmodium lophurae, was liberated from duck erythrocytes with antiduck erythrocyte serum and freed from host cell nuclei by differential centrifugation followed by treatment with trypsin and DNAase. Total as well as mitochondrial DNA isolated from such a preparation of free parasites showed overlapping densities of 1.679 g/ml in CsCl density gradients. To retain the structural integrity of mitochondrial DNA, the treatment of liberated parasites with trypsin and DNAase was eliminated and all steps of isolation of the mitochondrial fraction was performed at ice bath temperature. Under these conditions, mtDNA liberated by osmotic lysis appeared as super coiled molecules. After isolation of DNA from mitochondrial pellets prepared under the above conditions, only a single DNA band was apparent in ethidium bromide/CsCl gradients and open circular molecules with a mean contour length of 10.3 mum were observed.


Effect of the exotoxin of Bacillus thuringiensis on the biosynthesis and maturation of mouse liver nuclear RNA. The effect of the exotoxin of Bacillus thuringiensis on the in vivo incorporation of [14-C] orotic acid into mouse liver nuclear rRNA and low molecular weight RNA was studied. The following results were obtained. 1. The exotoxin does not inhibit the synthesis of 45 S pre-rRNA, but causes a breakdown of these molecules. 2. The exotoxin inhibits the conversion of 38 S pre-rRNA into 32 S and 21 S. 3. The exotoxin inhibits the labelling of nuclear 5 S RNA, whereas the labelling of 4.6 S pre-tRNA is not affected. It is suggested that 5 S RNA may control the processing of 45 S pre-rRNA.


Inhibitor of protein synthesis co-isolating with polyribosomal RNA. Although low concentrations of total polyribosomal RNA from porcine parotid glands or rat pituitary cells in culture (GH3) isolated by standard dodecylsulphate/phenol, chloroform extraction techniques can direct the incorporation of radiolabeled amino acids into proteins using a cell-free protein-synthesizing system derived from wheat germ embryos, higher concentrations inhibit the translation of endogenous wheat germ mRNA, or added rabbit globin mRNA or polyribouridylic acid. This inhibitory activity is separated from poly(A)-rich RNA by oligo(dT)-cellulose chromatography. The inhibitory activity appears to reside in a heat-stable protein since it is inactivated by incubation with various proteases but not by DNAase I, pancreatic ribonuclease, alkaline hydrolysis, or treatment with formamide. Specificity of the inhibition is suggested since the inhibitory fraction prepared from GH3 cells also inhibits protein synthesis in a cell-free protein-synthesizing system derived from porcine parotid gland, while the inhibitory fraction prepared from porcine parotid gland has no inhibitory activity in this homologous system. Radioiodination and dodecylsulphate/polyacrylamide gel electrophoresis reveal several protein bands, the most prominent with an apparent molecular weight of 78 000.


Amino acid incorporation into protein by ribosomes bound to chloroplast thylakoid membranes: formation of discrete products. A system which incorporates amino acids into proteins of chloroplast membranes of Chlamydomonas reinhardti is described. It consists of chloroplast ribosomes bound to thylakoid membranes and cell extract. mRNA is present in this thylakoid-ribosome complex, since neither initiation nor RNA synthesis seems to be required for amino acid incorporation. Incorporation requires ATP, GTP and a soluble portion of cell extract. It is inhibited by chloramphenicol, but not cycloheximide. Most incorporated radioactivity remains bound to the membranes. Although a large portion of this labeled membrane-bound protein occurs as nascent polypeptides, a portion appears at least four products of discrete molecular weights. The major in vitro product migrates as a polypeptide of 23 000 daltons. We conclude that a portion of chloroplast membrane proteins is not only made within the chloroplast, but directly on the membranes. We had previously observed that release of membrane-bound ribosomes is partially dependent on puromycin, and concluded that some membrane-bound ribosomes were attached to the membranes through nascent protein chains. Thus, our results suggest that some chloroplast membrane proteins are inserted into the membranes as they are synthesized. This chloroplast membrane amino acid incorporation system offers a promising tool for studying biosynthesis of membrane proteins, and how they become inserted into chloroplast thylakoids to form functional membranes.


Incorporation of amino acids into protein from an intracellular pool of lymphocytes. The nature of the precursor pool for protein synthesis in porcine lymphocytes has been investigated. Intracellular free glycine was found to be used in preference to its extracellular counterpart. It is suggested that a similar preference applies for all amino acids. However, with certain amino acids such as phenylalanine, this preference is difficult to demonstrate because of a rapid exchange occurring between intracellular and extracellular pools. A small portion of the intracellular phenylalanine pool was found not to exchange rapidly but this was not important in the maintenance of protein synthesis. A different type of compartmentation of the intracellular glycine pool was apparent, but this was less well defined. During the course of these investigations it was demonstrated that the nature of the incubation medium is an important consideration for enabling correct interpretation of kinetic experiments. To maintain what appeared to be a constant rate of protein synthesis, lymphocytes had to be incubated in a comprehensive culture medium (basal Eagle's medium without serum); a declining rate of synthesis was observed if a simple buffered salts medium (Krebs-Ringer bicarbonate buffer) was used.


Cytochalasin B: effect on phospholipid metabolism and lysosomal enzyme release by leukocytes;. The effect of cytochalasin B on phospholipid metabolism and beta-glucuronidase extrusion by polymorphonuclear leukocytes from guinea pid peritoneal exudates has been studied. Cytochalasin B inhibited the engulfing of starch granules by leukocytes, but it enhanced the incorporation of 32-Pi into phosphatidic acid and the phosphoinositidesmit also stimulated the release of beta-glucuronidase into the incubation medium in the presence or absence of starch granulesmkinetic studies showed that the effects of cytochalasin B on 32-Pi incorporation into phosphatidic acid and the phosphoinositides, and the release of beta-glucuronidase into the extracellular medium were comparablempulse-chase experiment revealed that cytochalasin B did not stimulate the isotopic decay of prelabeled lipids, indicating that cytochalasin B increased the radiophosphorus activity of phosphatidic acid and the phosphoinositides by increasing the synthesis of these lipidsmthe incorporation of myo-[2-3H]inositol into the phosphoinositides was also enhanced in the presence of cytochalasin B, but the incorporation of [methyl-14-C] choline into phosphatidylcholine and sphingogonyelin was unchanged;


Cell wall of Fusarium sulphureum; I. Chemical composition of the hyphal wall. The hyphae wall of Fusarium sulphureum Schlect. (Isolate 1) was isolated and purified. Electron microscopy studies showed that the isolated cell wall consisted of two distinct layers, an outer electron dense layer and a broader electron transparent inner layer. Chemical analysis revealed that the cell wall contained 66% carbohydrate, 7.3% protein, 5.5% lipid and 1.8% ash. The major cell wall component N-acetylglucosamine (39%) was shown by X-ray diffraction analysis to be present as chitin. Glucose constituted 14% of the cell wall, while mannose, galactose, and glucuronic acid, accounted for 15% of the cell wall. Glucuronic acid appears to be predominantly linked to galactose in the intact wall.


[35-S]sulfate incorporation into myelin glycoproteinsmi=entral nervous system. The in vivo incorporation of [35-S]sulfate and [3H]fucose into rat brain myelin was investigatedmmost of the 35S in the myelin was in sulfatide, but about 4% was associated with the residual proteins after chloroform/methanol extraction. Polyacrylamide gel electrophoresis of these proteins indicated that the major 35-S-labeled component corresponded to the major fucose-labeled glycoproteinmthe labeling of this predominant glycoprotein with sulfate was more selective than with fucose, since there was relatively little incorporation of sulfate into some of the minor fucose-labeled glycoproteins. There was little or no 35-S associated with proteolipid or basic protein on polyacrylamide gels. The fucose-labeled glycoproteins were converted to glycopeptides by pronase digestion and separated into two major classes by gel filtration on Sephadex-G-50. Only the higher molecular weight class contained significant amounts of 35-S. The association of 35-S with the glycopeptides was not due to binding of sulfatide or free inorganic sulfate. The results indicate that the predominant myelin-associated glycoprotein in rat brain is sulfated.


[35-S]sulfate incorporation into myelin clycoproteins; II. Peripheral nervous tissue. The in vivo incorporation of [35-S]sulfate, [3-H]fucose and [3-H]leucine into sciatic nerve myelin was investigatedmpolyacrylamide gel electrophoresis of thr proteins indicated that the 35-S-labeling of proteins occurred almost exclusively in the major myelin protein; A smaller myelin glycoprotein migrating just ahead of the major one was labeled with [3-H]fucose but did not incorporate 35-S to a detectable extent. There was little or no 35-S associated with basic proteins on polyacrylamide gels when the proteins were extracted with chloroform/methanol; Fucose-labeled myelin glycoproteins were converted to glycopeptides by pronase digestion; The glycopeptides gave a single peak on tsephadex G-50 in which the 3-H and 35-S coincided. The association of 35-S with glycopeptides was not caused by binding of sulfatide or free inorganic sulfate. This study shows that the major myelin protein in the sciatic nerve of the rat is glycosylated and sulfated.


A novel method for the follow-up of shape changes in erythrocyte and other particles. The absorbance of a suspension of asymmetrical particles fluctuates when the suspension is stirred in a circular motion. The effect is due to the fact that particles move in spiral orbits and present alternatively their short or long axis to the narrow beam of light used for measurement. Changes in the shape of erythrocytes such as flattening and swelling could be detected and quantitated by measuring the change in the amplitude of the fluctuating absorbance. The diagnostic value of this method is under investigation.


Erythropoietin effects on iron metabolism in rat bone marrow cells. This paper describes a study of the incorporation of 59-Fe from 59-Fe-labelled rat transferrin into rat bone marrow cells in culture. 59-Fe was found in both stroma and cytoplasm of marrow cells, and the cytoplasmic 59-Fe separated by polyacrylamide gel electrophoresis, into ferritin, haemoglobin and a low molecular weight fraction. The incorporation of 59-Fe into all three cytoplasmic fractions, but not into the stroma, increased progressively with time. Erythropoietin stimulated the increase of 59-Fe in ferritin within 1 h, the earliest time examined, and more than 3 h later in the stroma and haemoglobin. A proportion of the 59-Fe incorporated into the stroma and low molecular weight iron fractions during a 1 h incubation with 59-Fe-labelled transferrin was mobilised into ferritin and haemoglobin during a subsequent 4-h "cold-chase". Erythropoietin, when present during the "cold-chase", did not influence these 59-Fe fluxes. The erythropoietin stimulation of 59-Fe incorporation into ferritin, one of the earliest erythropoietin effects to be recorded, was therefore considered to be due to an increase of 59-Fe uptake by the hormone-responsive cells rather than a direct effect on ferritin synthesis. 20-h cultures containing erythropoietin when incubated with 59-Fe-labelled transferrin for 4 h, showed dose-related erythropoietin stimulation of 59-Fe incorporation into haemoglobin only. In the presence of 10 mM isonicotinic acid hydrazide, 59-Fe incorporation into haemoglobin was inhibited, as in reticulocytes (Ponka, P. and Neuwrit, J. (1969) Blood 33, 690-707), while that into the stroma, ferritin and low molecular weight iron fractions, was stimulated; there were no reproducible effects of erythropoietin.


Rapid uptake by liver sinusoidal cells of serum albumin modified with retention of its compact conformation. The clearance from the blood and the conformation of serum albumin modified by nitroguanidination and labeled with 125-I have been studied. Like formaldehyde-denatured albumin, but in contrast to native albumin, the nitroguanidinated derivative is rapidly cleared from the blood and taken up in lysosomes of liver sinusoidal cells. Although 94% of the free amino groups were blocked by nitroguanidination, we could not detect significant conformational changes using gel filtration, determination of reducible disulfide groups, and titration of tyrosine residues. It is concluded that extensive denaturation is no prerequisite for the uptake of albumin derivatives in liver sinusoidal cells. It is suggested that the nitroguanidinated protein, in contrast to native albumin, is bound on membrane receptors of sinusoidal cells. The nitroguanidino groups themselves might be bound on these receptors, but it seems equally possible that the blocking of positive charges of the albumin molecule or minor, local conformational changes of the protein are sufficient for the binding on the receptors.


Distribution of silicon in the adult rat and rhesus monkey. The distribution of silicon in tissues of the rat and rhesus monkey was determined using a colorimetric method specifically designed for biological materials. Soft-tissue silicon levels in both species varied from 1 to 33 mug silicon/g dry weight (ppm) excepting the primate lung and lymph nodes, which averaged 942 ppm and 101 ppm, respectively. This distribution may reflect flow-through of silicon in the form of particulates and water-soluble silicate contaminates in the environment and food effectively masking tissue or organ-specific silicon of functional significance. The silicon content of the whole rat femur was 38 ppm as determined by emission spectroscopy, whereas the monkey femur shaft was 43 ppm and the femur head containing the epiphysis was 456 ppm. This silicon may be functionally involved in the calcification process as suggested by others. The silicon content of rat liver subcellular fractions was also determined. The supernatant, nuclei/debris, and mitochondrial portions contained 0.6-1.0 mug silicon/g liver equivalents, whereas the microsomal fraction contained only 0.2 mug silicon/g liver equivalents.


Crystal structure of a compound featuring caffeine bound at C8 to ruthenium (III). The structure of a novel ruthenium purine compound, trans-chloro-8-caffeinechlorotriamminruthenium(III) chloride monohydrate, has been determined using single-crystal x-ray techniques. This compound crystallizes in space group Pbca (D152h) with cell dimensions a equal to 11.341 (3)A, b equal to 11.606 (5) A, c equal to 26.673 (7) A, Z equals to 8. The observed and calculated densities are 1.79 plus or minus 0.01 and 1.781 g/cm3, respectively. The structure has been refined using full-matrix least-squares methods to R equal to 0.059 based on 1314 independent observed reflections. The coordination geometry at the ruthenium atom is distorted octahedral. The carbon-ruthenium bond length is 2.03 (1) A. The chloride-ruthenium bond lengths are 2.350 (4) A and 2.427 (3) A for the cis and trans forms respectively suggesting a strong trans-influence due to the caffeine.


Properties of the red - violet complex of copper and penicillamine and further insight into its formation reaction. A characteristic red-violet chromophore which forms in the reaction of cupric ion with beta-sulfhydryl- alpha-amino acids has been attributed by several authors to a mixed-valence Cu3L2 structure. We have isolated and examined the analogous chromophore of the chelating drug penicillamine (beta, beta-dimethyl-cysteine), finding instead a polymeric anion with a mixed valence Cu2L2 repeating unit. Direct evidence for a mixed valence polymer cooroborates earlier conclusions of Wilson and Martin (9). Under oxygen-free conditions the anionic complex forms in essentially quantitative yield according to the following reaction: (see article). It has been established that this reaction is halide ion-dependent. The chromophore may be isolated as a sodium salt. This form was found to be stable, and it possessed no measurable activity as an oxidation catalyst. It was also demonstrated through biological experiments with rabbits that a significant amount of the complex- (between 6 percent and 39 percent) is recovered in the urinary tract following intravenous infusions attaining between 1.8 and 10 ppm copper.


A selective role for potassium in the phytotoxicity of thallium. The presence of K-ion prevents inhibition of Plantago maritima seed germination and Asperigillus flavus mycelial growth by Tl-ion. The effect of potassium could not be replaced by Na-ion in either system. Aspergillus was cultured in a medium low in light metal ions (Na+ and K+), and its growth was enhanced quantitatively by addition of Kminus but not Na-ions. Growth without added potassium was inhibited severely by Tl-ions, whereas K-enhanced growth was not. It is suggested that the thallium-potassium interaction is specific involving competition between ions of quite similar charge and radius.


A study of the temperature dependence of the electronic spectra of alkyl cobaloximes. The temperature dependence of the electronic spectra of the alkyl-pyridinatocobaloximes in benzene solution was found to be due to an equilibrium existing between two forms proposed to be inner-sphere and outer-sphere coordination compounds. Evidence is presented to rule out the possibilites of equilibria with pentacoordinated or dimeric forms, as well as a form with the cobalt out of the plane of the dimethylglyoxime.


Ethanolamine ammonia-lyase: inactivation of the holoenzyme by N2O and the mechanism of action of Coenzyme B12. Functional ethanolamine ammonia-lyase is inactivated by N2O as well as by O2, indicating that the active form of coenzyme B12 is an enzyme-bound corrin derivative in which the Co-C bond of the coenzyme is broken and the cobalt ion is in the +1 state of oxidation. The nucleoside fragment formed in the process of coenzyme activation is tentatively identified as 4',5'-didehydro-5'-deoxyadenosine. A mechanism of action of ethanolamine ammonia-lyase is formulated in analogy to that of DL-1,2-Propanediol dehydrase and compared to proposed alternative reaction schemes.


Influence of parenteral zinc and actinomycin D on tissue zinc uptake and the synthesis of a zinc - binding protein. Parenterally administered zinc markedly increased the incorporation of 14-C-cystine and 65-Zn into a low molecular weight zinc binding protein (ZnBP) isolated from liver cytoplasm of rats fed an adequate amount of zinc. This zinc load significantly increased the zinc content in the liver. The increase in hepatic zinc content was inhibited by actinomycin D indicating that DNA-dependent RNA synthesis is required for zinc uptake into liver. Antinomycin D also produced a concomitant decrease in ZnBP synthesis indicating that this protein may be involved in the uptake mechanism in cells. Zinc repletion also stimulated the synthesis of hepatic ZnBP in zinc deficient rats. This stimulation was also prevented by prior administration of actinomycin D. A similar effect was observed in the intestinal mucosal cells. The data collectively indicate that the control of the synthesis of ZnBP which occurs at the transcriptional level of protein synthesis is responsive to zinc status and thus may have a function in zinc metabolism.


An NMR relaxation study of polynucleotide - nucleotide interactions. A study has been made of the influence of polyuridylic acid (poly U)-adenosine (A) interactions upon the NMR proton relaxation behavior of H2O protons in aqueous solutions doped with Mn++ ions. Factors investigated included the effect of adenine oligonucleotide chain length, nucleoside concentration, and temperature upon the relaxation behavior of H2O. The results show that in all cases where solution and temperature conditions favor 2 poly U:A triple strand formation, a significant enhancement in H2O relaxation rate occurs over that for poly U or nucleotide solutions alone. Moreover, plots of relaxation enhancement versus temperature show well-defined transition regions with the enhancement approaching values for free poly U above the transition temperature, TM. The data also show that TM increases with increasing adenosine concentration and oligomer chain length. No comparable changes were observed for poly U solutions containing guanosine or cytidine derivatives. The increased relaxation rate in 2 poly U:A solutions is consistent with a more rigid secondary structure in the complex than in poly U; melting of this structure leads to an increase in polymer segmental mobility and a corresponding decrease in relaxation rate. The "melting" transitions and variation of TM with concentration and chain length have been interpreted quantitatively in terms of recent statistical models and yield values of delta H = -20 plus or minus 3 kcal/mol (base triplet) and delta S = -63 plus or minus 10 cal/mole degrees K (base triplet) in satisfactory agreement with results of optical studies.


Biological potency of organic selenium compounds: VI. Aliphatic seleninic acids and carboxyselenic acids. Straight-chain aliphatic seleninic acids, CH3-(CH2)n-SeOOH, with chain lengths from C4 to C17, a few dibasic acids of moderate chain length having seleninic acid groups on both ends of the molecule, HOOSe-(CH2)n-SeOOH, and a series of carbosyseleninic acids, HOOC-R-SeOOH, comprising chain lengths from C3 to C13 and several branched chains with 5 to 7 carbon atoms were tested for potency in the prevention of dietary liver necrosis in the rat. Alkylseleninic acids showed uniformly low activities, ranging from 18% to 56% of that of selenite selenium which served as a standard. There were no discernible trends or regularities with increasing chain lengths, in c-ntrast to other series of alkylselenium compounds. It is therefore unlikely that alkylseleninic acids are normal oxidation products of dialkyl mono- or diselenides in the organism. Compounds with seleninic acid groups at both ends of the chain were practically inactive. Carboxyseleninic acids carrying a carboxyl group distal to the seleninic acid group, on the other hand, were highly effective. A maximum of potency occurred at chain lengths C3 and C4, followed by a sharp decline between C4 and C6. A second maximum of activity occurred at C8. There was no alternating effect. This structure/activity pattern is analogous to that of the diselenodicarboxylic acids. However, the lower carboxyseleninic acids were, per atom of selenium, twice as active as the corresponding diseleno-dicarboxylic acids, of which the higher members were less potent. It is inferred that carboxyseleninic acids may be metabolically related to diseleno-dicarboxylic acids and that C3 and C4 carboxyseleninic acids may play a physiological role.


Structural and electronic effects on the polarographic half-wave potentials of copper (II) chelate complexes. Polarographic measurements in dimethylformamide solution have been performed on 37 bis-chelate Cu(II) complexes containing primarily salicylaldimine, geta-ketoamine, beta-iminoamine, and pyrrole-2-aldimine ligand systems. The complexes were selected in order to reveal the effect of stereochemical and donor atom variations on half-wave potentials. Mono- and binuclear complexes undergo one-and two-electron reductions, respectively, which were established for representative cases by controlled potential coulometry. The response of Cu(II)/Cu(I) potentials to these variations reveals that nonplanar bis-chelate complexes are easier to reduce than their planar analogs, rigid planar tetradentate or related planar bis-chelate complexes, and complexes differing only in donor atoms are more readily reduced in the order N4 less than N2O2 less than N2S2. Binuclear complexes are reduced in one two-electron or two resolvable one-electron steps depending on ligand structure. Potentials of these and other complexes previously examined are considered in relation to the markedly positive potentials of "blue" copper proteins and ligand structural features which might afford Cu(II)/Cu(I) potentials in the protein range are noted.


A catheter-tip capacitance pressure transducer. A simple miniature capacitance pressure transducer is described. The operational characteristics of the device when mounted on the tip of a 6.3 F catheter are discussed and results of in vivo trials illustrated, using a commercially available catheter-tip pressure transducer for comparison.


Delayed signal EEG trigger.

Delayed signal EEG trigger. Long EEG recordings are often necessary to capture the signals in the short period just before an epileptic attack. This procedure has many disadvantages. The equipment described  below enables only the signals of interest to be recorded. It is designed to operate in conjunction with a commercial electroencephalograph and consists of a signal store with a programmable series of logic gates for sensing the onset of an epileptic discharge and activating the chart recorder. The particular system described has a signal bandwidth of d.c. to 25 Hz in all 16 channels, and, because of their particular clinical diagnostic importance, all signals for the 20 seconds immediately preceding the discharge are recorded. The recording can take place for up to one hour after the attack and, if a second attack should occur, it can also be recorded similarly to the first one.


Porous surface layered prosthetic devices. The method of fabrication and properties of a dual structured implant system consisting of a metallic porous surface layer is described. The ingrowth of bone tissue into the outer porous surface layer results in part fixation, while the solid inner core region provides the necessary mechanical strength for a device used for the replacement of heavy load bearing joint regions such as the hip and knee. Additionally, novel implant systems are suggested using the porous coating concept.


Medical equipment hazards--practical experience in a large region. An investigation has been carried out into the cause of accidents involving patient interfaced medical equipment, in a large region over a period of 3 years. In a high proportion of accidents the cause is faulty design, or poor construction of equipment. However, a considerable number can also be attributed to lack of user appreciation of the hazards involved. A few accidents have been caused by inexperienced personnel attempting to service equipment about which they have little knowledge.


Engineering considerations in the design of an ankle joint. A prothesis has been designed to replace the articulating surfaces of the human ankle joint.  The prothesis is in two parts, each forming a segment of a right circular cylinder with a single axis of rotation.  The concave tibial component is manufactured from ultra-high molecular weight polyethylene and the talar component is manufactured from medical grade stainless steel.  It is likely, however, that the talar component will be commercially manufactured from cobalt chrome alloy (Vitallium or Vinertia).  The two components are secured to the cancellous bone by polymethylmethacrylate bone cement and laboratory tests have indicated that the bond should be strong enough to withstand the loads encountered at the ankle joint in vivo.  The tests have also shown that the stability and strength of the ankle are not seriously reduced by implantation of the prosthesis.  Laboratory wear tests and clinical experience over the last two years encourage optimism over the long term performance of the prothesis.


A catheter-manometer calibrator--a new clinical instrument. Although catheter-manometer systems are widely used in clinical medicine, little effert has been make to evaluate the accuracy of these systems.  There is consequently a need for an acceptable method of evaluating the complete pressure recording system under clinical conditions, i.e. a catheter-transducer system that be put together and kept sterilised during the preparation of the patient and applied promptly after static and dynamic calibration of pressure under sterile conditions is described.  All kinds of catheters, connectors, transducers, as well as the effect of different fluids or air bubbles on the measuring system, can be investigated.  The value of the instrument, especially in clinical practice, is demonstrated and discussed.


Biogenesis of chloroplast membranes in Chlamydomonas reinhardi: Chloroplast-controlled transfer of cytoplasmic proteins to the developing chloroplast membranes as visualized by quantitative radioautography. The light-induced formation of the photosynthetic membranes (greening) in y-1 mutant of Chlamydomonas reinhardi requires synthesis of new proteins which become incorporated into the growing membranes. It has been shown previously (Eytan and Ohad, 1970) that proteins synthesized by both chloroplast and cytoplasmic ribosomes concur in the formation of functional photosynthetic membranes, indicating the presence of a mechanism permitting the specific transfer of membrane proteins synthesized in the cytoplasm into the chloroplast. Transfer of such proteins cannot yet be identified by the usual biochemical techniques unless they become part of the growing photosynthetic membranes. However, it is possible to follow their synthesis and translocation between the different cellular compartments by use of quantitative electron microscopic radioautography. In the present work, the radioautographic grain distribution among chloroplast, chloroplast membrane, nucleus, mitochondria, and the remainder of the cytoplasm (cytosol) was carried out following short radioactive pulse-labeling and chase during greening of dark-grown mutants in the presence or absence of protein synthesis inhibitors. The results indicate that transport of some of the proteins of cytoplasmic origin to their final location within the chloroplast is at least partially controlled by concomitant synthesis of proteins by the chloroplast ribosomes.


Kinetics of lysosomal storage of indigestible matter. In lysosomal storage diseases and in accumulation of lipofusion in the lysosomes there is a gradual eroding of the lysosomal system due to overloading the lysosomes by molecules which cannot be digested or expelled. The kinetics of this accumulation is examined for tissue cultures in terms of the cell growth rate, lysosomal production rate, and of generation of the indigestible element.


Laser light-scattering investigations of the teleost swimbladder response to acoustic stimuli. When a laser pencil is directed through the teleost swimbladder fringe patterns can be seen in the far-field that are (a) highly sensitive to the orientation and position of the swimbladder with respect to the incident pencil and (b) a representation of contributions from each membrane through which the light passes. The fringe pattern fluctuates in intensity, and to some extent in position, in response to driving forces that distort the swimbladder. The spectrum of these very small distortions can be measured by standard light scattering techniques. This method was used to study the response of in situ swimbladders to imposed acoustic fields and evidence for a sharp roll-off of the response at frequencies above 1,000 Hz was found. Models for these effects are discussed.


Some self-consistent two-state sliding filament models of muscle contraction. The general formalism required to treat two-state sliding filament models of muscle contraction, including free energy considerations, is first reviewed and amplified. This formalism is then used to examine, and modify as needed, three models studied previously by Podolsky and Nolan, in which cross-bridge attachment-detachment and ATP turnover are not tightly coupled. No attempt is made here to establish an optimal, self-consistent model of this type because our interest is primarily in methadology rather than in fitting experimental results. But it appears from this preliminary study that such a model, with satisfactory mechanical and thermodynamic properties, could be found. An extremely simple but unrealistic two-state model is also studied which is of interest because it demonstrates the fact that it is possible, in principle at least, for sliding filament models to work with very high thermodynamic efficiencies (50-100 percent). An appendix is included that is concerned with the form of the dependence of certain first-order rate constants on the concentrations of ATP, ADP, and P.


Intercellular connectivity in the eight-cell Xenopus embryomcorrelation of electrical and morphological investigations. The distribution of individual intercellular electrical junctions has been examined in eight-cell Xenopus embryos using linear systems analysis. Morphological evidence for corresponding intercellular contacts has been sought by light microscopy and scanning electron microscopy. The electrical investigation indicated that each cell is directly coupled to each of the other seven cells by identical resistive junctions. Scanning electron microscopy of the cell surfaces of cleaved embryos revealed protrusions from the surfaces of the cells which could mediate such intercellular connections. Light microscopy of serial sections through the embryos also showed fine processes of the cell surfaces which come into contact with several other cells. The complete intercellular connectivity suggested by these results appears to be an extension of similarly close connectivity in the two- and four-cell embryos. The possible significance of this high connectivity to morphogenesis is discussed.


A model of myoglobin self-organization.

A model of myoglobin self-organization. The self-organization of helical regions of myoglobin into a compact tertiary structure is considered on the basis of the hypothesis on the step-wise mechanism of self-organization of protein molecules. It is assumed that the self-organization begins with the formation of "centers of crystallization" and proceeds with the growth of on such center or by a sequential collapse of two or more grown centers. Different pathways of self-organization of myoglobin are considered; the most favourable structures corresponding to the greatest number of dehydrated bulky hydrophobic groups and to all the strongly hydrophilic groups exposed to water are selected at every stage of the given pathway and the others are neglected. One of the two most favourable structures obtained in such a way coincides in rough resolution with the native tertiary structure of protein.


Determination of the equilibrium constants of self-associating protein systems. XI. The application of C-(r) in graphical analysis and the enumeration of interacting species in the ultracentrifuge. A greatly simplified procedure is proposed which employs C equals f(r) as determined from sedimentation equilibrium measurements in graphical analysis of self-associating protein systems and in the enumeration of interacting species in the ultracentrifuge. Basic equations given here are applicable to any self-associating system. A procedure is outlined for enumeration of interacting components independent of non-ideal behavior, using principal component analysis.


[Cholinergic and adrenergic innervation of the microvessels of serous membranes]. The morphological substrate of double (sympathetic and parasympathetic) innervation of the vessels of the microcirculatory bed of serous coat was studied in cats. The architectonics of both components of the vasomotor innervation in the pericardium, the pleura and the peritoneum was examined by histochemical methods used for revealing the cholinergic (Koelle-Gomori) and the adrenergic (Falck-Hillarp) neutral structures. the quantitative predominance of the elements of adrenergic innervation over the cholinergic ones was revealed in the identical portions of the arterial bed. Vegetative innervation of the terminal arteries and capillaries was unsteady in character and proved to be essentially confined to single synaptic contacts arising along the course of adrenergic and cholinergic terminals. Vegetative innervation of the venous supply including the postcapillary venules and small collecting veins was extremely poor and frequently not found at all.


[Surface electrical properties of the formed elements of the blood and blood coagulation properties]. Isoosomotic solutions of lithium, potassium and rubidium chlorides promoted hemocoagulation, and sodium chloride failed to influence the processes of blood coagulation. There proved to be no direct relationship between the changes in the processes of blood coagulation and the surface electrical charge of erythrocytes and platelets. Hemocoagulation changes were apparently associated with the whole complex of surface phenomena occuring on the border of division of phases (blood cells membrane-blood plasma), and also with specific influence of the ions under study on the functional properties of erythrocytes and platelets.


[The neuronal composition of the intramural nerve plexi of the gastrointestinal tract]. The neuronal population of the intramural ganglia of the gastrointestinal tract was studied in cats by the method of fluorescent microscopy. Three neuronal populations were revealed in the intramural ganglia of the intact animals. The first population showed no specific catecholamine fluorescence. The perikaria of the second population were not fluorescent, but there were adrenergic synapses on the surface of these nerve cells. The third population of the neurons displayed a specific catecholamine fluorescence of the perikarion and the processes. Intraperitonal injection of exogenic noradrenaline in a dose of 1 mg produced an increase in the number of the nerve cells with a specific fluorescence which permitted us to suggest that the intramural ganglia of the gastrointestinal tract contained, along with parasympathetic intramural neurons, also the sympathetic ones the majority of which were capable of specific fluorescence only after an induced elevation in them of the mediator content.


[The effect of hypoxia on the function and metabolism of alveolar macrophages]. Cytochysiological and cytophotometric studies carried out for 9-11 days on rabbits showed that hypoxic hypoxia (equivalent to the altitude of 5000 m) led to depression of the phagocytic activity of the alveolar macrophages. Simultaneously macrophages of the lungs displayed an increase in the activity of lactic and glucoso-6-phosphoric dehydrogenases, and a reduction of malic dehydrogenase activity. Experiments carried out in vitro with the macrophages of guinea pig lungs demonstrated that cell respiration served as the principal source of energy required for phagocytosis. A conclusion was drawn that respiratory inhibition in hypoxia was not compensated by activation of glucolysis and glucose metabolism in the pentose shunt and was the principal cause of disturbances of the phagocytic function of macrophages of the lungs.


[Ultrastructural changes in the nephron during ischemia and organ "survival"]. Ultrastructural analysis of the epithelium of the proximal and the distal portions of the kidney nephron of albino rats in "survival" of the organ in the cadaver and in experimental ischemia showed a different reaction of the cells to these actions. An intracellular edema and characteristic changes in the ultrastructure of the mitochondria appear in the tubular epithelium during the organ autolysis in the animal cadaver. Under conditions of experimental ischemia, against the background of intracellular edema, there develop marked changes in the lysosomal apparatus of the cells, swelling of the mitochondria and also a marked dilatation of the cysternae of the endoplasmic reticulum and of the Golgi complex.


[Mechanisms of the effect of orotic acid on the growth and development of young rats]. Chronic administration to ratlings of potassium orotate in a dose of 75 mg/kg from the 5th to the 14th day and of 150 mg/kg from the 15th to the 30th day after birth led to a significant acceleration of growth and functional maturation of the animals. The rate of growth in the experimental ratlings was much greater at periods of from the 5th to the 14th and from the 21st to the 30th days than in control animals, but showed no significant difference on the 14th-20th days. Growth acceleration at the period of from the 5th to the 14th days dues to a higher (in comparison with control) activity of the vegetative systems (increased oxygen consumption, frequency of respiration and cardiac contractions at rest). On the 21st-30th days growth acceleration in the experimental animals was associated with an earlier reduction in the activity of the vegetative systems and of the sympathico-adrenal regulation mechanisms, this being pointed to by a fall in catecholamine content in the adrenal glands and the brain.


[Post-tetanic hyperpolarization of lake-frog isolated nerve fibers]. Posttetanic hyperpolarization (PTH) parameters of a single node of Ranvier remained unchanged with increase of the stimulation duration of over 0.1 sec. PTH was insensitive to strophanthin, but was eliminated by tetraethylammonium. Resistance of the membrane of node of Ranvier measured by the amplitude of anode impacts proved to be lovered during the PTH by 50%. A conclusion was drawn that PTH of the isolated nerve fibers was caused by the persistence of increased potassium permeability during and after the end of tetanus. An increase in duration of tetanization failed to lead to the appearance of PTH associated with active ion transport.


[Dynamics of nucleic acid and protein concentration and synthesis during adaptation to hypoxia]. Adaptation of female Wistar rats to hypoxia was carried out in the altitude chamber (barochamber) for 40 days, 6 hours per day at the altitude of 7,000 meters. By the end of the adaptation the relative weight of the lungs increased by 37 per cent (this seeming to indicate hypertrophy of the lungs), and the concentration of RNA in the lung tissue increased by 30 per cent; at the same time the RNA concentration in the lungs as a whole increased by 85 per cent DNA concentration in the lung tissue showed no essential change, and its content in the lungs increased at the same rate as the lungs' weight. An increase in protein synthesis in the lungs determined by the S-35-methionine incorporation constituted 133% in the adapted rats in comparison with control.


[An autoradiographic study of kidney tissue with different frequency of exposure to a pathogenic factor]. The kidney tissue was examined under normal conditions and also with a single and repeated administration of mercuric bichloride at intervals of 1 day and 1 week, autoradiographically with the use of thymidine-H3. Male albino mice (26) weighing 25-30 g were used in these experiments. Control mice displayed a relatively greater label index in the epithelium of the proximal tubules. With a more frequent action of the pathogenic factor on the kidney there proved to appear more DNA-synthesizing cells. It is supposed that the existing interrelationship between the number of labeled cells of the epithelium of the proximal tubules and of the flattened cells lying under their basal membranes served as a peculiar index of the regenerative manifestations in the tissue of the injured kidney.


[A microfluorometric study of cell nucleus DNP-complex renaturation]. A study of the kinetics of renaturation of the DNP in the nuclei of human peripheral blood lymphocytes with the aid of modified Riglers method showed the absence of renaturation of the preparations preliminarily headed to 65 degrees C. Heating the preparations to higher temperatures (75, 85 and 100 degreesC) led to the appearance of characteristic renaturation profiles with the maximum at a two-minute incubation (direct measurement of the intensity of fluorescence of the nuclei of cells transfered into a cold citrate-salt solution, as a time function).


[The mechanism of the anticonvulsive action of diazepam]. Diazepam was shown to be highly efficient in preventing the convulsive siezures induced by thiosemicarbazide and connected with GABA insufficiency. In recording the recovery cycles of the intracortical response of the cat motor cortex it was found that diazepam induced a decrease of the testing respone. These data indicate the enhancement of the inhibitory processes. Using this test an antagonistic relationship was observed between diazepam on the one hand, and biculline and thiosemicarbazide--on the other Diazepam was capable of increasing GABA content in the brain by suppressing GABA-transaminase activity in the mitochondrial fraction of the brain tissue.


[The concentration of adenylic nucleotides in vescular walls following application of octadine and ornid]. It was shown in experiments on rabbits that administration of octadine (10 mg/kg) and of ornid (10 mg/kg) and 1 hour (respectively) before the assessment failed to cause and changes in the adenylic nucleotides and inorganic phosphorus content in the aortic wall. Octadine administration led to reduction of the catecholamine level, but ornid, administered once or repeatedly, failed to cause any changes in the tissue catecholamine content. Repeated administration of these drugs in the same doses for 10 days caused an increase in the adenosinmonophosphoric acid content alone, without any essential changes in the other adenylic nucleotides and inorganic phosphorus content. An increase in the adenosinmonophosphoric acid content can be regarded as one of the mechanisms of pharmaco-mechanical relaxation of the smooth muscles in the vascular wall.


[Pentacyclic triterpenes and ion excretion by rat kidneys]. Experiments were conducted on rats. A study was made of water, sodium, potassium and creatine excretion 3 hours after the administration into the stomach of a 5% load with a 0.9% NaCl solution. In comparison with control, sodium excretion decreased considerably in the animals given 2 mg per 100 g of weight of trioxylupane or heterobetulin; water, potassium and creatine excretion remained unchanged. Sodium and water excretion increased with administration of dioxylupenal in a dose of 2 mg per 100 g of weight. Heterobetulin also increased the urinary potassium excretion under conditions of administration to rats of a 5% load with a 1.25% KCl solution. The data obtained were of interest for the understanding of the interrelationship between the structure of the substances and their physiological activity.


[The effect of polysaccharide from typhoid bacteria on hemopoietic stem cells]. A study was made of dynamics of the content of colony-forming units (CFU) in the spleen and the bone marrow of the nonirradiated F1 (CBA times C57BL) mice to which polysaccharide (PS) from typhoid bacilli was administered. A method of exogenous colony formation was used in this work. A single PS administration increased the CFU count in the bone marrow (2-2 1/2 times) and in the spleen (3 times). Repeated (6- and 9- time) administration of PS was not more effective than a single one. Apparently PS acted as an inductor which caused proliferation of the stem hemopoietic cells and maintained this process for a definite period of time automatically.


[Restitution of the immune response by macrophages following administration of immunodepressants to mice]. A study was made of the restitution by peritoneal macrophages of the primary immune response in the organism of C3H mice immunized with bacteriophage T2 after the depressive effects of actinomycin D, olivomycin, rifamycin, chloroquin, chloramphenicol, of the histone F2a fraction and LPS. The cell transfer technique was used for studying the capacity of macrophages from normal mice to restitute the antibody synthesis in mice given immunosuppressive drugs. In cell transfer experiments the recipients immunosuppressed by drugs were capable of initiating a normal primary response to bacteriophage T2 when given macrophages from normal donors. The data obtained with the drug-treated recipients supported the concept that the antigen processing by the macrophage was necessary for initiating a primary type immune respones; they also demonstrated the selective susceptibility of macrophages to the immunosuppressive drugs.


[Formation of complete and incomplete antibodies by rabbits immunized with sheep erythrocytes]. A parellel determination of incomplete and complete antibodies in rabbits immunized by various doses of sheep erythrocytes demonstrated that reduction of the titres of complete antibodies occurred more rapidly than that of imcomplete ones. Complete 7S-antibodies appeared in the blood of animals immunized with high doses of erythrocytes or after a repeated injection of low antigen doses. Incomplete 7S-antibodies are determined in the blood of rabbits after a primary immunization with high and with low doses of sheep erythrocytes, The titres of incomplete hemagglutinins were almost the same in the reaction with crude and trypsinized erythrocytes. As to the titres of complete hemagglutinins, they were greater in the reaction with trypsinized erythrocytes than in the reaction with crude cells, and approached the titres of incomplete antibodies.


[Features of microcirculation in the liver during anaphylactic shock]. Microcirculation in the liver was studied in rats and dogs with anaphylactic shock. Injection of a reacting dose of the horse serum led to elevation of systemic arterial pressure by an average of 20 mm Hg; there also occurred spasm of the sinusoids, hepatic venules and an acceleration of blood flow in them With the following blood pressure reduction to 60-40 mm Hg there was blood congestion in the vessels, retarded circulation, intravascular aggregation of the blood formed elements, hemorrhages and ischemic changes. Restoration of systemic arterial pressure and of microcirculation occurred in parallel; no complete normalization of microcirculation in the liver ensued, yet.


[The effect of adrenaline and cyclophosphamide on the growth and blood supply of experimental Guérin carcinoma]. Tests were conducted on albino rats with experimental Guerin carcinoma. A method of the blood vessel injection and preparation of lucid and stained (with hematoxylin-eosine) sections, and determination of the density of the capillary network were used; intramuscular adrenaline injections proved to produce an inhibitory effect on the growth of Guerin carcinoma, this bein accompanied by its intensified microvascularization. Combined administration of cyclophosphan and adrenaline produced a marked antitumour effect on accout of an antiblastic actionof cyclophosphan enhanced by adrenaline. The detected direct relationship between the vascular system of Guerin carcinoma, the thickness of the capillary network and the effect of the theraputic action of cyclophospahan and adrenaline pointed to the role played by the blood supply of Guerin carcinoma in the antiblastic action of cyclophosphan in case of combined administration with adrenaline.


[Use of scanning electron microscopy for studying the intersection of lymphocytes with tumor cells]. With the aid of steroscan microscopy it was found that the state of surface membranes of the cells under study showed a significant change during the interaction of lymphocytes of BALB/C mice--bearers of methylcholantrene-induced sarcoma--with autologous tumour cells. Lymphocytes separated from the autologous tumour cells by a millipore filter formed long cytoplasmic processes which passed through the filter pores and came into close contact with tumour cells. Tumour cells acquired a spherical shape, and became swollen; "openings" appeared in the surface membrane, and this led to cell lysis.


[Diurnal changes in the duration of mitosis in several tissues of young white rats]. In the acinar cells of the pancreas of 7-day rats the duration of mitosis varied from 1.7 to 2.5 hours, in the hepatocytes--from 1.3 to 5.2 and in the epidermis--from 1.5 to 2.9 hours. The 24-hour variations in the mitotic index were expressed both by the changes in the duration of mitosis and by unequal rate of the cell entrance into mitosis. The peroid of renewal of the tissues under study markedly differing in adult animals proved to be approximately the same in rats aged 7 days (12,3 days in the pancreas and 20 days in the liver and the epidermis).


[Circadian rhythm of total histone concentration in noradrenalinergic and serotoninergic neurons and their glial satellite cells]. By means of photoelectric aperture cytospectrophotometry of fast green FCF strain sections the total histone content was determined in the nuclei and whole bodies of the neurons of the reticular formation, as well as in the nuclei of their glial satellite cells during various periods of the 24-hour cycle. In the noradrenalinergic neurons of the reticular formation of the lateral nucleus ther was revealed a circadian rhythm of the changes in the total histone content with the two maxima and the two minima per 24 hours in the neuronal bodies, but with only one period of fluctuations per 24 hours in their nuclei. On the contrary, in the 5-hydroxytryptaminergic (serotoninergic) neurons of the paragiant-cell nucleus of the reticular formation the total histone content changes once in 24 hours in the cell bodies, but twice within the same period in the neuronal nuclei. The amplitude of fluctuations was markedly lower than in the corresponding neurons in the cells of the perineuronal neuroganglia,


[A cytochemical study of the dynamics of RNA synthesis as revealed in the metaphase chromosomes of HeLa cells]. The rate of DNA and RNA synthesis was determined by autoradiography using selective procedure for obtaining large numbers of mitotic HeLa cells. It was shown that RNA which was resistant in situ to ribonuclease in solutions of high ionic strength was synthesized mainly at the end of the G1 period and the first part of the S period. The synthesis of RNAse-resistant RNA was not detected at the G2 period and during mitosis.


[The effect of partial hepatectomy on the quantity of somatotropes in rat adenohypophysis]. Two thirds of the liver was removed by Higgins and Andersons method in which male rat weighing from 100 to 150 g. Adenohypophysis of partially hepatectomized, sham-operated and intact rats was studied 2, 4, 8-10, 25 hours, 2, 3, 6, 10, 14, 21 days after the operation. There was revealed a significant increase in the number of somatotropes 8-10 hours after the partial hepatectomy and a decrease in their content 25 hours after the operation, in comparison with their number in the smham-operated rats. The content of somatotropes in the adenohypophysis of the partially hepatectomized rats returned to the normal by the second postoperative day and failed to show any significant changes at the subsequent observation periods. The data obtained permit a supposition to be made on the participation of somatotropic hormone in the regulation of the restorative processes in the liver.


Oxymetholone treatment for sickle cell anemia. Seven patients with sickle cell anemia were treated with oxymetholone for at least 2 mo. Markedly increased basal rates of hemolysis and erythropoiesis were confirmed. The urinary erythropoietin excretion was either normal or lower than expected for the red cell mass, and an expanded blood volume was due primarily to an increased plasma volume. After androgen therapy, six patients demonstrated more than a fivefold increase in urinary erythropoietin, with an increase in red cell mass ranging from 17%-75% above the control value. All showed a decline in serum iron level to the 25-75 mug/100 ml range within 4 wk after the start of therapy. Less marked changes followed lower oxymetholone doses. Reversible hepatic toxicity, with a serum bilirubin concentration exceeding 50 mg/100 ml, occurred in one patient. Androgenic hormone therapy may be useful for selected adult patients with sickle cell disease when severe anemia contributes to disease morbidity.


Metabolic effects of antisickling amounts of nitrogen and nor-nitrogen mustard on rabbit and human erythrocytes. Nitrogen mustard (NH2) and Nor-nitrogen mustard (Nor-HN2) both inhibit the polymerization of deoxyhemoglobin S in solution and in intact erythrocytes. Metabolic studies were undertaken to determine the feasability of an extracorporeal treatment with these or related agents. Glucose utilization, hexose monophosphate shunt activity, methemoglobin reduction, and incubation with acetylphenylhydrazine for Heinz body formation were performed, as well as specific assays for hexokinase, pyruvate kinase, glucose-6-phosphate dehydrogenase, glutathione reductase, ATP, reduced glutathione (GSH), and survival of autologous mustard-treated cells in rabbits. HN2 was found to enter red cells rapidly and bind to intracellular contents. Metabolic studies revealed no significant inhibition or alteration of function by Nor-HN2 at 10 mg/ml of whole blood. Rabbit red cell survival was also normal. HN2, however, inhibited glutathione reductase and blocked the free sulfhydryl group of GSH by forming serveral addition products of alkylated GSH. Heinz body test with acetylphenylhydrazine became positive in HN2-treated cells, and rabbit red cell survival was shortened considerably in the concentration range used to inhibit sickling. Ascorbic acid stimulation of the hexose shunt pathway was inhibited by HN2, but methylene blue stimulation remained unaffected. 14-C-HN2 remains bound to red cells in vivo, and the disappearance of radioactivity is similar to that found with 14-C-DFP (disopropylfluorophosphate). Oxygen affinity of both HN2 and Nor-HN2 treated human red cells remains virtually the same as that found in control samples. It is concluded that Nor-HN2 may be a suitable agent for an extracorporeal therapy, and that each mustard needs to be evaluated individually for its antisickling effects and its suitability for extracorporeal use.


Tolerance to the granulocyte-releasing and colony-stimulating factor elevating effects of endotoxin. Injection of Salmonella typhosa endotoxin into either CF1 or C57bl/6J mice leads to prompt increases in serum colony-stimulating factor (CSF). Repeated injections of endotoxin result in a dose-related hyporesponsiveness or tolerance to this effect. Tolerance is seen after either intravenous (i.v.) or intraperitoneal (i.p.) routes of administration or challenge and occurs after one to two preinjections. Cross-tolerance to heterologous endotoxin (Escherichia coli) was also shown. This cross-tolerance is complete immediately after cessation of preinjections, but partial at later time intervals. Levels of a serum inhibitor of colony growth were decreased in tolerant mice, although this decrease is not statistically significant. Tolerant mice injected with endotoxin release granulocytes from the bone marrow normally, in spite of the absence of a CSF response. This suggests that neutrophil releasing activity (NRA) and CSF are separate entities. A marked marrow granulocytic hyperplasia develops after 7 or 20 days of endotoxin injections, despite the tolerance to the CDF-elevating effect of endotoxin. This granulocytic hyperplasia could still be mediated by serum CSF increases. A negative medullary feed-back secondary to the repetitive release of marrow granulocytes, however, is an equally plausible mechanism for the stimulation of granulocyte production. It is also possible that the decrease in serum inhibitors played a role in the sustained increase in granulopoiesis seen here.


Selective damage to erythroblasts by 55-Fe. The low energy and short range of 55-Fe Auger electrons were utilized in mice to deliver lethal intracellular radiation to iron-incorporating erythropoietic precursors with minimal radiation damage to other bone marrow cells. The ensuing intramedullary, selective erythropoietic death was demonstrated by absolute and differential bone marrow cell counts and by decreased blood uptake of 59-Fe. The decreased number of colony-forming units in spleen colony assay and the decreased ability of tranplanted bone marrow to protect fatally irradiated mice shows that the bone marrow was partially depleted of pluripotent stem cells. These data are interpreted to indicate an increased pluripotent stem cell utilization in response to increased demand for differentiation of stem cells along the erythropoietic pathway.


Granulopoietic progenitors in suspension culture: a comparison of stimulatory cells and conditioned media. Kinetic studies have been carried out to investigate the functional heterogeneity previously observed in populations of human marrow or peripheral blood cells separated by velocity sedimentation. The results obtained confirm the earlier results, in that slowly-sedimenting cells were found to stimulate both colony formation by granulopoietic progenitors and an increase in numbers of granulopoietic progenitors in suspension culture, while rapidly-sedimenting cells stimulated only colony formation and not increased progenitors in suspension cultures. Investigations of the properties of media conditioned by these two subpopulations of cells revealed no clear differences between them; both stimulated suspension cultures as well as colony formation, and both lost the former activity, but not the latter, after dialysis. The results contribute to the evidence that more than one process is regulated in cultures of granulopoietic progenitor cells.


In vitro granulocyte production in patients with Hodgkin's disease and lymphocytic, histiocytic, and mixed lymphomas. The in vitro granulocyte colony formation (CFU-C) was examined in 19 untreated patients with advanced Hodgkin's disease and in 25 untreated patients with histiocytic, lymphocytic, and mixed lymphomas. The patients with Hodgkin's disease and diffuse histiocytic, lymphocytic, and mixed lymphomas produced decreased numbers of granulocyte colinies, whereas patients with nodular histiocytic, lymphocytic, and mixed histiocytic-lymphocytic lymphomas showed normal granulycote colony growth. The acute response of CFU-C to combination chemotherapy (MOPP) is described in two patients followed with sequential marrow cultures through their indiction chemotherapy. The long-term effect of MOPP chemotherapy was examined in five patients who had completed chemotherapy 1.5-6 yr priot to in vitro examination.


[Course and prognosis of panmyelopathy and isolated aplastic anemia. Retrospective study in 70 patients]. From 1967 to 1972, 70 patients with aplastic anemia were observed and followed up to death or at least two years. 3 cases of pure red cell anemia, and 2 cases of amegakaryocytic thrombocytopenia are included. Detailed investigation of drugs taken within 6 months before onset of the disease revealed chloramphenicol in 20, butazones in 11 cases. Acute viral hepatitis preceded the hemopoietic failure in 2 patients. In addition to various combinations of anemia, granulocytopenia and thrombocytopenia, monocytes were diminished in 35 and lymphocytes in 12 cases. Acid serum or sucrose tests were consistently negative. The patients were treated by short-term prednisone, long-term androgens and red cell and platelet substitution as needed. 2 years after onset of the disease, 33 per cent were in partial or complete remission, 30 per cent survived without remission, and 35 per cent had decreased. Correlation of various parameters with remission and survival showed the presence of a subgroup at risque, comprising patients with low marrow cellularity and clinically relevant diminution of all three cell lines at the time of diagnosis. Absolute lymphopenia and increase of plasma cells in the bone marrow were of poor prognostic significance. In this subgroup two years after the onset of the disease only 32 percent survivors and 16 per cent remissions were recorded. There was no conclusive evidence for the therapeutic value of prednisone or androgens in our series. The present situation in severe aplastic anemia requires more effective forms of treatment and justifies experimental therapies like bone marrow transplantation.


Two rare complications of chronic benzene poisoning: myeloid metaplasia and paroxysmal nocturnal hemoglobinuria. Report of two cases. Two patients, one with myeloid metaplasia and the other one with PNH, both due to chronic exposure to benzene are presented. The patient with PNH exhibited also marked monocytosis as a rare hematologic finding of chronic benzene exposure. The etiological relationship between myeloid metaplasia, PNH and chronic benzene exposure is discussed.


[Determination of purine derivatives in blood and plasma fractions]. A method is described for the separation of adenine and guanosine from whole blood and plasma fractions, containing purinderivatives as anticoagulant-additives. The highest concentration determined per gram human albumin or gamma-globulin was 0.5 mg. Due to interactions with blood cells guanosine could only be detected in plasma which was stored for more than one week as whole blood. The amount of adenine and guanosine to be expected in therapeutical products is uncritical according to published pharmacological investigations.


[Isolation and characterization of a 19S-alpha1-glycoprotein from human erythrocytes and its identification as placenta protein PP6]. A high molecular weight protein was isolated from the hemolysate of washed human erythrocytes by a procedure involving ion exchange chromatography, ammonium sulfate fractionation and gel filtration. The purified protein was found to have a sedimentation coefficient of 18,68S and a molecular weight of 8 times 10-5 to 1 times 10-6 daltons. In the presence of sodium dodezylsulfate the molecules are dissociated into at least four different subunits having molecular weights ranging from 12,000 to 30,000 daltons. The protein has the electrophoretic mobility of an alpha-1-globulin and an isoelectric point of pH 4.75. The chemical analysis revealed that the protein is chemical and immunochemical properties the 19S-alpha-1-glycoprotein from human erythrocytes was shown to be identical with the protein PP6 isolated from huamn placentae. The content of this protein in packed red blood cells was determined to be around 50 mg per 100 ml.


Studies on combined effects of organophosphates and heavy metals in birds. I. Plasma and brain cholinesterase in coturnix quail fed methyl mercury and orally dosed with parathion. We found that mercury potentiated the toxicity and biochemical effects of parathion. Male Coturnix quail (Coturnix coturnix japonica) were fed a sublethal concentration of morsodren (4 ppm as methyl mercury) for 18 weeks. This resulted in an accumulation of 21.0 ppm of mercury in the liver and 8.4 ppm in the carcass. Birds fed clean feed and those fed morsodren-treated feed were orally dosed with 2, 4, 6, 8,and 10 mg/kg parathion, and their 48-h survival times compared. The computed LD50 was 5.86mg/kg in birds not fed morsodren and 4.24 in those fed the heavy metal. When challenged with a sublethal, oral dose of parathion (1.0 mg/kg), morsodren-fed birds exhibited significantly greater inhibition of plasma and brain cholinesterase activity than controls dosed with parathion. Brain cholinesterase activity was inhibited 41% in morsodren-fed birds and 26in clean-fed birds dosed with parathion, which suggested that the increase in parathion toxicity in the presence of morsodren was directly related to the inhibitation of brain cholinesterase.


The effects of lapsed time since feeding upon the toxicity of zinc to fish. This study was undertaken to determine the effects of elapsed time from feeding to exposure upon the tolerance of goldfish (carassiu auratus l.) to zinc. Methods followed those in the 24 hour static bioassay of the Ohio River Valley Water Sanitation Commission (SMITH et al., 1973). Fish were fed for 25 minutes and at specific times after feeding (0, 1, 2, 4, 6, 12, 24, 72 hours) groups of 10 fish were placed into 18 liters of water containing a lethal concentration (100 mg/l) of zinc as ZnSO4. Time until death was recorded for individual fish. A total of 420 fish (excluding controls) were exposed to zinc in the course of seven experimental runs. Statistical analysis revealed a slight but non-significant increase in survival time as the interval between feeding and exposure to zinc increased. These variations in survival time do not appear to be of sufficient magnitude to support the standard acute bioassay requirement that fish not be fed for 24 or 48 hours prior to their exposure to a toxicant.


DDT: short term effects on osmoregulation in black surfperch (Embiotoca jacksoni). DDT injected intraperitoneally into black surfperch caused substantial increases in plasma osmotic concentration only at doses much larger than are likely to be encountered in nature. Increased plasma concentrations were below those tolerated by fish adapted to high salinities. Death of marine teleosts from DDT poisoning probably involves factors other than simply osmoregulatory failure.


Lead extraction from aluminum.

Lead extraction from aluminum. The lead content of various aluminum samples was determined. The amount of lead was found to be in the range from 28-45 ppm. The leaching of lead from aluminum products by 5% acetic acid was negligible at room temperature, but up to 2 mg/liter was leached at 85 degrees C. Although no significant health hazard exists in the usage of aluminum in contact with food items, it is recommended that aluminum containers be conditioned by several extractions with dilute acetic acid at higher temperatures.


Susceptibility of bluegil sunfish (Lepomis macrochirus) to nonionic surfactants. The present report provides a basis for direct comparison of the susceptibility of fish to alkylphenol and alcohol ethoxylates of various EO chain lengths. It is obvious from the data provided that susceptibility of bluegil to nonionic surfactants (both types) increases with decreasing EO chain length. Also it appears that bluegill are no more susceptible, and, in fact, are probably less susceptible to the acute effects of alkylphenol ethoxylates than of alcohol ethoxylates.


The technique of recording nasal pharyngoscopy. Nasal pharyngoscopy is a relatively simple and most informative technique requiring a small amount of very portable equipment. Recording the observations objectively is of considerable clinical and research value, but will require a two-man team, one of whom must be thoroughly versed in audio-visual communication techniques and apparatus. The equipment is more expensive and although it can be transported is probably best used at a routine site.


A simplified method of recording in nasal pharyngoscopy. In view of Pigott's work, it would appear that a pharyngoplasty without prior pharyngoscopy is similar to an operation on the bladder without cystoscopy. Now that a simple method of recording, which we consider invaluable, is available, we hope that nasal pharyngoscopy will become a routine examination in patients with speech defects.


The superomedial dermal pedicle for nipple transposition. A new method for nipple transposition employing a superomedial dermal pedicle is described for use in reduction mammaplasty and dermal mastopexy. The advantages include superior mobility, viability, sensation and normal appearing nipples and areolae.


Evidence that adrenergic nerves are responsible for the active uptake of noradrenaline in the guinea-pig isolated trachea. 1 6-Hydroxydopamine (50 mg/kg, i.p.) was given to guinea-pigs to destroy the adrenergic nerve terminals in the trachea. 2 The destruction was demonstrated by fluorescence histochemistry, which showed a marked loss of beaded fluorescent terminal fibres and by electrical transmural stimulation of the isolated atropinized trachea, which showed a marked reduction of dilator responses. 3 Such tracheae showed greatly reduced uptake-with-retention of (minus)-[3H]-noradrenaline in incubation experiments and the efflux curve of radioactive material showed a selective but incomplete reduction in the volume of the slowly exchanging compartment. 4 It is concluded that much, but perhaps not all, of the uptake-with-retention occurs into adrenergic nerves.