The influence of a granulocytic inhibitor(s) on hematopoiesis in an in vivo culture system. The in vivo diffusion chamber (DC) technique for mouse marrow culture was used to determine the effect of a granulocyte inhibitor on the proliferation of the pluripotent stem cell(CFU-s) and the granulocyte progenitor cell (CFU-c). Granulocyte conditioned medium was injected intraperitoneally into mice bearing DCs during the initial 48 hr of culture. The early injections of inhibitor resulted in a significantly reduced number of granulocytic progeny formed within the DCs while there was no growth inhibition of mouse fibroblasts cultured under identical conditions. The reduced cell production was due in part to a significant reduction in the self-renewal rate of the CFU-c while no apparent direct effect was observed upon the growth of the CFU-s within the same cultures. These data suggest that the granulocytic inhibitor(s) acted to reduce the proliferation within the CFU-c population and thereby diminished the amplification potential inherent in the initial cell inoculum.


Analysis of time dependent changes of lymphopoietic activity in organ cultures of embryonic chicken thymus. The time dependent development of lymphocytes in organ cultures of the thymus obtained from 10-day-old chick embryos was characterized by an initial phase of exponential increase of the number of lymphocytes per thymus followed by a plateau phase with no further increase in cell number. The proportion of cells in DNA synthesis dropped rapidly during the first 10 days of culture. Simultaneously the lymphocytes turned progressively smaller, as evidenced by both cell diameter and dry mass and constituted a homogeneous population of small cells at the end of the culture period. Thymic anlagen partially depleted of lymphoid precursor cells by a short hot pulse with 3H-TdR showed a prolonged exponential phase and reached normal plateau cell numbers 2-4 days later than usual. Furthermore, at least in the first part of the plateau phase, a reduction in the number of lymphoid cells per thymus resulted in a recovery in terms of the cell number which was associateed with increased DNA synthesis. These results are compatible with the regulation of thymic lymphopoiesis in organ culture through a mechanism operating via cell density.


Frequency of occurrence and position of cilia in fibroblasts of the periodontal ligament of the mouse incisor. Solitary cilia occur in motile as well as in non-motile fibroblasts of the peridontal ligament. The cells which moved with the erupting incisor are bipolar and oriented with their long axes parallel to the tooth surface. In cross section these cells have a flattened appearance. Cilia are localized in close vicinity to the nuclear area and show a definite orientation with respect to the transverse cell axis. The frequency of occurrence of this organelle was estimated from the percentage of diplosomes containing a basal body. Analysis of the composition of the paired structures indicated that at least 70 per cent of the fibroblasts are ciliated. The frequency of cilia in motile fibroblasts does not differ from that in non-motile cells suggesting that the presence of this organelle is not directly associated with cell locomotion.


Tanycyte absorption affected by the hypothalamic deafferentation in Japanese quail, Coturnix coturnix japonica. In Japanese quail, Coturnix coturnix japonica the tanycytes of the median eminence absorbed peroxidase injected into the third ventricle. The number of tanycytes showing peroxidase reaction was greater in the posterior median eminence than in the anterior median eminence. Following hypothalamic deafferentation, the tanycyte absorption was augmented both in the posterior and anterior median eminence. These findings suggest that axons of some neurons, which have inhibitory action on the tanycyte absorption, were transected by deafferentation resulting in augmentation of tanycyte absorption. A considerable number of ependymal cells lining the upper portion of the third ventricle and those of the pars nervosa also absorbed peroxidase. In birds with a deafferented hypothalamus, photostimulated ovarian growth was completely inhibited.


The organization of the lamina ganglionaris of the prawn, Pandalus borealis (Kröyer). The Lamina ganglionaris (first optic neuropile) of the decapod crustacean Pandalus borealis has its optic cartridges (synaptic compartments) arranged in horizontal rows. Each optic cartridge contains seven receptor axon terminals and the branching axis fibres of five monopolar second order neurons. Four types of monopolar neurons are classified. Their cell bodies are arranged in two layers. The inner layer contains the cell bodies of exclusively one of these types, and each cartridge is invaded by two neurons of this neuron type (type M 1:a and M 1:b). The outer layer contains the cell bodies of the remaining three types (M 2, M3 and M4). One gives rise to a large radially branched axis fibre in the centre of the cartridge. The other two have wide branches which may make inter-cartridge contacts, one proximally and the other distally in the plexiform layer, which is clearly bistratified. The receptor axons terminate in two levels corresponding to these strata. Two sets of tangenital fibres form networks in the proximal and the mid-portion of the lamina. Both networks have fibres with primary branches in the vertical plane and secondary branches in the horizontal plane. The fibres of the networks are derived from axons that pass from the second optic neuropile, the medulla externa.


Occurrence of oxyphil cells in suppressed parathyroid glands. Parathyroid glands from Mongolian gerbils cultured for 7 days at a high calcium concentration and examined by electron microscopy, were found to contain suppressed chief cells containing numerous mitochondria, and some oxyphil cells containing an abundance of medium-sized or large mitochondria with calcium-containing precipitates. It is suggested that parathyroid chief cells may be transformed into oxyphil cells, under certain conditions, and that the associated increase in the number and size of the mitochondria may be related to an intracellular accumulation of calcium.


Granule containing cells and fibres in the sinus venosus of elasmobranchs. The concentrations of catecholamines in the heart chambers of elasmobranchs were measured by the fluorimetric method of Bertler et al. (1958). Noradrenaline (NA) can be detected in all the chambers, but the sinus venosus is by far the richest in NA. This can either be due to the presence of storage sites for this amine in the sinus wall, or to a transport of amine to the sinus venosus from the anterior chromaffin bodies. The sinus wall contains large numbers of "granule containing cells" and axon-like processes, both with numerous dense-core vesicles of about 1800 A diameter. The dense-core vesicles contain a uranophilic matrix indicating the presence of protein, phospholipids and/or nucleic acid. The reactions failed to demonstrate amine, which may be due to a loss of amine by diffusion, to a relatively low intravesicular amine concentration, or, to the absence of amines in these granule-containing cells and processes. Heavy accumulations of granule-containing processes occur in the subendothelial area. The endothelium contains fenestrae and pores through which granule-containing fibres protrude into the venous cavity. Granule-containing cells are innervated by presumed cholinergic nerve endings. It is suggested that the granule-containing cells and fibres belong to the neurosecretory system with a cholinergic input, releasing the contents of the dense-core vesicles into the blood stream at the level of the venous cavity.


The effect of cervical vagotomy (decentralization) on the ultrastructure of the carotid body on the duck, Anas platyrhynchos. Carotid bodies of ducks show no detectable changes in ultrastructure up to periods of four weeks following the removal of 2-3 cm of the cervical vagus (decentralization). This indicates that the majority, and possibily all the nerves terminating on the glomus cells are afferent (sensory) in nature. These nerve endings are in reciprocal synaptic contact with the glomus cells and therefore have efferent and afferent functions. Theories concerning the carotid body receptor mechanism are discussed with particular reference to those theories which ascribe functions to the reciprocal synapses.


Comparative histochemical and electron microscopic studies of the sinus and venous walls of the human spleen with special reference to the sinus-venous connections. Sinus and venous walls of normal human spleens were studied with enzyme histochemical and electron microscopic methods. Particular attention was paid to the connections between sinuses and veins. Histochemically the sinus lining cells revealed a distinct naphthol-AS-acetate-esterase activity but no reaction for alkaline phosphatase. Venous endothelial cells were positive for the latter but negative for the former enzyme. In the sinus-venous junctional area there were no endothelial cells with reactivity for both enzymes. Electron microscopically both the sinus lining cells and the venous endothelial cells could be clearly characterized and therefore easily distinguished from one another on morphological grounds. There were no clear ultrastrural indications of transitional forms between sinus lining cells and venous endothelial cells in the sinus-venous area. According to these findings, sinus lining cells represent a specialized endothelium, but one with practically no morphological similarities to the venous endothelium.


Myoid cells in the peritubular tissue (Lamina propria) of the reptilian testis. The arrangement and fine structure of peritubular myoid cells was studied in the testes of three species of reptiles (Lacerta dugesi, Testudo graeca and Natrix natrix) during two short periods of the seasonal cycle (European spring and autumn) and correlated with some ultrastructural properties of Leydig cells. The lamina propria consists of myoid cells, fibroblasts and non-cellular components comprising collageneous and non-striated microfibrils. Both components are arranged in alternating layers surrounding seminiferous tubules. In spring the lamina propria of lacertilian testis shows 1-5 layers of myoid cells which are rich in 50-70 A filaments and exhibit plasmalemmal and intracellular dense patches, smooth vesicles along the cell membrane and a concentration of organelles in a juxtanuclear position. Leydig cells are rich in smooth ER profiles and have few lipid droplets. In atumumn most myoid cells are replaced by fibroblast-like elements. Leydig cells display large numbers of lipid droplets and dense bodies, but only small amounts of agranular ER. Similar changes are noted in Leydig cells of Testudo and Natrix. However, in these species the boundary tissue of seminiferous tubules fails to show significant alterations comparing spring and autumn animals. In both species the lamina propria exhibits a few fibroblast-like cells interspersed among myoid cells.


Observations on the fine structure, enzyme histochemistry, and innervation of parathyroid gland and ultimobranchial body of Chthonerpeton indistinctum (Gymnophiona, Amphibia). Fine structural and enzyme histochemical observations on ultimobranchial body and parathyroid gland of the caecilian Chthonerpeton are presented. The cell clusters and follicles of the ultimobranchial body consist mainly of granulated cells which are termed C-cells and obviously belong to the APUD cell series. In the larger follicles additional possibly exhausted degranulated cells and replacement cells occur. A rich supply of nerve fibres has been found in this gland. Frequently nerve terminals were observed to come into synaptic contact with the C-cells. Two categories of nerve fibres occur: a) fibres containing large polymorphic electron dense granules (probably purinergic fibres), b) fibres containing small electron transparent vesicles and a few electron dense granules (probably cholinergic fibres). The parathyroid gland consists of elongated cells (one cell type) poor in organelles and often containing fields of glycogen and lipid droplets. The cells are further characterized by fair amounts of lysosomal enzymes; they are interconnected by maculae adhaerentes and occludentes. No nerves and blood vessels have been found in the parathyroid gland of Chthonerpeton.


Electron microscope studies on the intermediate lobe of the embryonic mouse. The development of the intermediate lobe of the hypophysis was studied in the embryonic C3H mouse; at least four glands from embryos of every gestational day from 15 to 19 were examined. In the 16 day-old embryo prospective secretory cells proliferate at the centre of the intermediate lobe anlage. At the same stage cylindrical cells bordering the hypophyseal cleft begin to reorganize into marginal cells. By the end of fetal life marginal cells are well differentiated. In the 17 day-old embryo a few granular inclusions appear in some centrally located cells. Secretory cells increase in number during the following two embryonic days. Some of these cells contain polymorphic populations of granular and vesicular inclusions by gestational day 19. The possibility of a dual formation of secretory inclusions is discussed. The result implies that the onset of granule-formation by these cells is not contemporaneous with the start of production of melanophore-expanding substances, the presence of which has been detected by earlier biological assays.


Ultrastructural changes in spermatozoa of the brush-tailed possum, Trichosurus vulpecula (Marsupialia), during epididymal transit. Part I: The flagellum. During epididymal transit, a fibre network and an array of vesicles develop in the posterior two-thirds of the midpiece in sperm of the Brush-tailed possum, Trichosurus vulpecula. The fibre network is developed by the time the sperm reach the corpus epididymidis, and is composed of evenly spaced, helically arranged fibres lying immediately beneath the plasma membrane. The angle of these fibrous helices is always counter to that of the underlying mitochondrial helix. Separating the fibre network from the mitochondria is a layer of granular material which develops at the same time, and over the same length of the midpiece as the fibre network. A somewhat tenuous fibre network is found between the fibrous sheath and plasma membrane in the anterior principal piece of sperm from all regions of the epididymis. The array of vesicles is developed by the time sperm reach the cauda epididymidis. The vesicles resemble pinocytotic vesicles; some appear as invaginations of the plasma membrane, and are open to the medium surrounding the spermatozoon by a narrow neck, while others are entirely enclosed within the spermatozoon, and lie at varying distances between the plasma membrane and the layer of granular material.


Ultrastructure of the larval firefly light organ as related to control of light emission. The firefly larva has a pair of light organs consisting of a layer of interdigitating, light emitting cells, covered dorsally with a layer of opaque, white cells. Each light organ is ventilated by one large and several smaller tracheal branches and is innervated by a branch of the segmental nerve containing two axons. These axons branch profusely in the photocyte layer so that several nerve profiles are seen around any photocyte. Nerve terminals contain large dense-core vesicles and small light-core vesicles. Clusters of light-core vesicles surrounding irregularly shaped membrane densifications, presumably the synapses between nerve and photocyte, are common in nerve terminals. Light emitting cells in insects characteristically contain photocyte vesicles. In the larva there are both full and empty photocyte vesicles; the full vesicles contain a matrix with tubular membrane invaginations in contrast to the empty vesicles which contain amorphous membrane invaginations.


Junctions in the central nervous system of the cat. IV. Interendothelial junctions of cerebral blood vessels from selected areas of the brain. Interendothelial membrane contacts in different segments of brain blood vessels were investigated by the freeze-etching technique. The study demonstrated that the endothelial cells of the pre- and postcapillary segments were coupled by elaborate zonulae occludentes. These tight junction formations encompassed gap junctions of different sizes and distribution. The globules of the pre- and postcapillary tight junctions revealed a great fragility which led to an atypical distribution of the sealing elements. In the "typical" brain capillaries the endothelial cells were connected by continuous  tight junctions. In contrast to the structural continuity of these formations the fenestrated segments of capillaries in the choroid plexus and area postrema demonstrated discontinuous fasciae occludentes. They were composed of rows of individual particles which should be regarded primarily as focal in nature.


Responses of the ultimobranchial body in eels (Anguilla anguilla L.) maintained in sea water and experimentally matured, to injections of synthetic salmon calcitonin. The effect of a synthetic salmon calcitonin (SCT) treatment on ultimobranchial body (UB) activity in eels (Anguilla anguilla L.) maintained in seawater and submitted to experimental maturation, has been studied histologically. 2. The activity of the glands of a control group of eels maintained in sea water was taken as a reference. 3. The UB parenchyma showed a marked atrophy in the fish treated with SCT alone and serum calcium decreased significantly in this group. 4. Immature female silver eels receiving carp pituitary extract (CPE 1 mg/100 g body wt. per injections) until complete maturation presented high hypercalcemia associated with cellular hypertrophy and hyperplasia in the UB. 5. SCT treatment did not prevent the hypercalcemia provoked by CPE injections. UB activity was strongly increased in this case. 6. These data indicate that the activity of the UB in eels varies with both physiological and experimental hypercalcemia, and responds to SCT injections.


The ultrastructure of the swimbladder of the toadfish, opsanus tau L. The anterior chamber of the swimbladder of the toadfish Opsarmustau L. is lined by a single layer of columnar gas gland cells, cuboidal cells that resemble gas gland cells but are located outside of the gas gland region, and squamous cells. Multilamellar bodies are numerous in the gas gland cells and the cuboidal cells and are present in smaller numbers in the squamous cells. Capillaries lie in the lamina propria directly below the epithelial lining. A thick continuous muscularis mucosae and a submucosa consisting of tightly packed cells, cell processes, and connective tissue may contribute to the impermeability to gases of the wall of the anterior chamber. The posterior chamber of the swimbladder is lined by a single type of squamous epithelial cell. Multilamellar bodies were occasionally observed in these cells also. Other types of cells frequently form a partial second layer between the epithelial lining and the basement lamina. A thin muscularis mucosae lies directly below the basement lamina and the capillaries of the posterior chamber are located in the submucosa. The tunica externa is a layer of dense connective tissue that surrounds both the anterior and posterior chambers. Collagen fibrils in the form of tactoids are present in this layer.


Ultrastructural changes in granulosa lutein cells and progesterone levels during preimplantation, implatation, and early placentation in the western spotted skunk. The ultrastructure of corpora lutea obtained during the preimplantation implantation and early post-implantation periods has been studied in 20 western spotted skunks. Fine structure of granulosa lutein cells was correlated with progesterone levels. The corpus luteum of the prolonged (7 month) preimplantaion period contained undifferentiated small granulosa cells and differentiated large granulosa lutein cells. The former ranged in size between 12 and 20 mu and the latter between 20 and 45 mu. The ratio of small and large cells was about equal in an animal 2 days prior to nidation whereas only few small cells and numerous large cells were observed in an animal estimated to be 8 to 12 hours from nidation. Occasionally small cells were observed amidst large ones during the 24 hour nidation period, i.e. adhesion of trophoblast with the luminal uterine epithelium, but small cells were absent in animals after this period. Small cells had some smooth and rough endoplasmic reticulum rod-shaped mitochondria with plate-like cristae, small Golgi complex, and relatively smooth plasma membranes. Large lutein cells had abundant smooth endoplasmic reticulum, membranous whorls of smooth endoplasmic reticulum, usually round mitochondria with tubular and lamellar cristae, a well developed Golgi complex, variable amounts of lipid droplets, and highly plicated and ruffled plasma membranes. Peripheral plasma progesterone levels during the prolonged preimplantation period ranged between 1.1 and 7.9 ng/ml, but during implantation it was between 8 and 16.6 ng/ml. It is suggested that plasma progesterone levels fluctuate during the time of implantation and should not be regarded as a basis to predict actual nidation in the western spotted skunk.


The fine structure of the kidney of the hagfish (Myxine glutinosa L.): A thin section and freeze-fracture study. The fine structure of the kidney (glomerulus and archinephric duct) of the hagfish. Myxine glutinosa (L.) was studied in thin sections and by freeze-fracture technique. The glomerular filtration barrier is similar to that of mammalian kidneys. However, endothelial fenestrations are relatively scanty and the basement membranes of endothelial cells and podocytes always appear separated by a layer of collagen fibrils and microfibrils often surrounding numerous and extended mesangial cells. Between podocytes and their processes maculae occludentes and peculiar junctions of another type occur. The zonulae occludentes between epithelial cells of the archinephric duct are composed of five or more strands, occasionally of only one or two.


The development and fine structure of ultimobranchial glands in larval anurans. II. Bufo viridis, Hyla arborea, and Rana ridibunda. A comparative optical microscopic and ultrastructural study on the ultimobranchial (UB) glands of three common species of Israeli anurans: Bufo viridis, Hyla arborea, and Rana ridibunda during metamorphosis is presented. The UB glands typically consist of a single follicle with a central lumen, though occasionally secondary follicles are present in Hyla and Rana. A single UB cell type is found which appears either in a very electron-dense "dark" form or as a less dense "light" form, though the ratio of dark: light cells from gland to gland at any one stage of metamorphic development is quite variable. By the end of metamorphosis in Bufo and Hyla all the UB cells are usually of the light variety, whereas in Rana the dark cells persist. The organelles of these secretory cells including secretory granules, granular endoplasmic reticulum, free ribosomes, tonofilaments, microtubules, Golgi bodies, and lipid droplets, their distribution, abundance, and possible functions in relation to metamorphosis are described. Apocrine secretion into the central lumen of the gland is also described and discussed.


Sizes and numbers of nuclei in the cortex of thymus glands of red-billed weavers Quelea quelea. The cortex of the thymus glands of embryos, chicks, juveniles, fledglings and adults from several colonies of Quelea quelea were studied using an image analyser (Quantimet 720) to determine cell populations and nuclear sizes. Just prior to hatching the lobes showed a high level of mitosis and consisted of predominantly small lymphocytes. The larger glands of chicks and juveniles had higher cell populations; pyknotic cells and erythrocytes occurred free in the cortex. The lobes of adults were more variable but in general mitosis occurred in enlarging glands of adults from colonies with eggs; most lobes contained pyknotic cells but not in such high numbers as in lobes from chicks and fledglings. Erythrocytes were common, occurring in large numbers in the cortex in some birds. The factors affecting the interpretation of these data are discussed in detail.


The fate of N-dansyl-L-phenylalanine in the cerebrospinal fluid after intraventricular and intracisternal injection: a comparative fluorescence microscopic and analytical study. Absorption, accumulation and release of N-Dansyl-L-phenylalanine (DPA) through the ependyma, plexus choriodei and brain parenchyma after intraventricular and intracisternal injection was examined at different postinjection intervals by fluorescence microscopy. The following results were obtained: 1. After intraventricular injection, DPA is rapidly absorbed from the ependyma and plexus choriodei in all ventricles and subsequently disappears from the various points of the ventricles at different times. DPA is no longer evident in the ependyma after 40 min and the plexus after 90 min. Aborption and storage occur primarily in the dopaminergic centers of the brain. This stage begins 5 min p.i. attains a maximum after 40 min and is maintained up to 180 min p.i. 2. If DPA is administered intracisternally, fluorescence is initially restricted to the ependyma and choroid plexus of the fourth ventricle and to the wall of the aquaeduct. Only at 5-10 min p.i. are rostral ventricular portions labelled. Passage of the amino acid out of the ventricle only occurs to a limited extent. 40 min after intracisternal injection, DPA is no longer demonstrable in the ependyma and plexus or brain parenchyma. 3. Intrathecally administered DPA appears in the periglomerular tubules of the kidney as well 2.5 min p.i. and is stored there for up to 40 min. The kidney medulla remains free of fluorescence. 4. DPA injected into the CSF is protein-bound.


Fine structural demonstration of acid phosphatase in rabbit germinal epithelium prior to induced ovulation. The germinal or surface epithelium covering rabbit Graafian follicles contains occasional small, dark, lysosome-like bodies. After an ovulatory dose of human chorionic gonadotropin (HCG) such bodies gradually increase in size and number. At 8 hr after HCG there is a maximal accumulation in the apical follicle cells; then the dense bodies decrease and just prior to ovulation, 9.5 hr after HCG, only few of them remain in the attenuated surface epithelium. Most of the growing membrane-surrounded bodies probably represent lysosomes, since electron microscopy combined with cytochemistry revealed that many of them contain the lysosomal "marker" enzyme, acid phosphatase. The role of sex steroids and prostaglandins regarding lysosomal growth and LABILization is discussed. The close temporal relation between disappearance of the apical surface epithelial lysosomes and disintegration of the underlying tunica albuginea gives further support to our working hypothesis that at least part of the "ovulatory enzymes" emanate from the surface epithelium.


Luteinizing hormone, progesterone and the morphological development of normal and superovulated corpora lutea in sheep. The development of granulosa-lutein cells was studied in 27 normal and 32 superovulated ewes between days 0-4(day 0 began with the preovulatory LH peak in normal animals and the HCG injection in superovulated ewes). The pattern of differentiation was similar in both groups. Following initial hormonal stimulation (0-12 hours after LH or HCG), granulosa cells were approximately 100 mu2 and contained small, pleomorphic nuclei with large amounts of clumped chromatin. Elongate cells lining the basement membrane possessed large, heterogeneous dense bodies, and a well-developed Golgi apparatus. Mitotic figures were observed up to 6 hours prior to ovulation. Sixteen to 20 hours following the LH surge or HCG injection, hypertrophy of granulosa cells was evident. Nuclei contained definitive nucleoli. Blood vessels in the theca interna were abundant and highly dilated. Ovulation occurred approximately 24 hours after the LH peak or HCG injection. Visible signs of luteinization were evident 6-12 hours after ovulation. A slight increase in serum progesterone levels was detected. The second post-ovulatory day was characterized by continuing hypertrophy of granulosa cells and extensive proliferation of smooth endoplasmic reticulum and mitochondria. Nuclei of granulosa cells were larger and possessed extremely large nucleoli. Numerous mitotic figures were apparent within the corpus luteum. Serum progesterone concentrations began increasing at 60-72 hours after hormone stimulation. By the end of the third post-ovulatory day, the corpus luteum consisted of large, pleomorphic, parenchymal cells, interspersed between capillaries and connective tissue elements. Only an occasional mitotic figure was apparent within the corpus luteum at 100 hours. Light microscopic autoradiography of 5, 10, and 15 day corpora lutea taken from ewes pulsed with 3H thymidine at specific times before and after ovulation revealed that granulosa cells did not undergo secondary mitoses following ovulation. In contrast, thecal, mesenchymal and endothelial cells did mitose on day 3.


Junctions in the central nervous system of the cat. V. The junctional complex of the pia-arachnoid membrane. The leptomeningeal tissue of the choroid plexuses and of the brain surfaces have been studied by means of the freeze-etching technique. The pia-arachnoid membrane and the subdural neurothel represent the morphological barrier between the extracerebral tissue and the cerebrospinal compartment. The freeze-etch findings indicate that the arachnoid and neurothelial cells are coupled by extensive zonulae occludentes which seem to represent the structural basis of the barrier mechanism provided by these cell layers. Furthermore, it became evident that gap junctions of considerable structural heterogeneity occur on the pial and arachnoid cells of the interstitial choroidal compartment and of the free brain surfaces. The structural heterogeneity of the nexuses is taken as an indication of the plasticity of the leptomeningeal tissue. The different morphological characteristics of the nexal formations are discussed with respect to their probable functional meaning.


Ultrastructural studies on neuromuscular contacts and the formation of junctions in the flight muscle of Antheraea polyphemus (Lep.). II. Changes after motor nerve section. In the moth Antheraea polyphemed at the onset of adult development. The subsequent breakdown of the isolated motor stulongated vesicles similar in structure to channels of smooth ER, appear in large numbers in the axoplasm. Their nature as well as the functional aspects of early axonal changes are discussed. From the 7th day onward two types of axonal breakdown become prominent. The first is characterized 0y swelling axon profiles, distorted vesicles and strongly shrunken mitochondria, uhile shrinking axon profiles containing tightly packed mitochondria and unaltered vesicles are typical of the second. Both types presumably take place independently of each other in different axon terminals. Axons and the contents of at least the first type are finally removed by transformation into lamellar bodies. Glial processes obviously behave independently of degenerating terminals; they loose any contact with them and never act as phagocytes for axon remnants. During the whole period of breakdown undifferentiated contacts between nerve fibers and muscle anlagen are present but synaptic structures as in normal developing dlm have never been observed. This fact, in comparison with earlier studies, suggests a lack of trophic nervous activity on the muscle anlagen tissue. A short time after removal of the isolated stumps new nerve tracts appear between dlm-fibers (which are, of course, strongly retarded in development). They are presumably sensory wing nerves which lack a guide structure to the central target, due to axotomy. Neuromuscular contacts or even junctions formed by axons of these nerves have occasionally been detected on the dlm. Their nature is discussed. Wallerian axon degeneration is compared to the normal, metamorphic breakdown of the innervation of the larval dlm-precursor. In contrast to the former, glial processes here remain in contact with the terminals. Glia and axons first swell. Then most glial processes are transformed into lamellar bodies whereas neurites shrink and become electron-dense. Axonal organelles remain intact for a long period.


Scanning electron microscope observations on the muscle innervation of Oikopleura dioica Fol (Appendicularia, Tunicata) with notes on the arrangement of connective tissue fibres. Critical point dried and fractured appendicularia of the species Oikopleura dioica have been examined in the scanning electron microscope. The dorsal nerve cord with ganglion cells and peripheral nerve fibres could easily be observed. Thick peripheral nerve fibres leave the nerve cord as bilateral pairs at constant intervals along the tail. Most of these fibres branch from the naked nerve cord, but some evidently originate in ganglion perikarya bulging out from the nerve cord itself. These paired peripheral nerves always have elaborate end-arborizations on the medial surface of the lateral muscle cells. They are accordingly interpreted as motor axons. Some thinner peripheral nerve fibres originate at irregular intervals from both the nerve cord and the ganglion cells. Due to the numerous extracellular fibrils that connect the bilateral layers of the epidermal fins and the muscle cells to each other, these thin nerve fibres can seldom be traced to their termination. A few ones can, however, be traced ventrally between the notochord and the muscle cells and seem to end in singular bulb-like expansions. Clusters of synaptic vesicles are present in transmission electron micrographs of such nerves, and they are accordingly believed to carry efferent impulses. The extracellular fibrils are arranged in a highly ordered pattern with thick bundles crossing the gap between the structures to be interconnected and with numerous radiating insertions on the surface of the tissues.


A scanning electron microscopic study of the rat liver sinusoid: endothelial and Kupffer cells. The surface ultrastructure of Kupffer cells in the rat liver has been studied by scanning electron microscopy (SEM). The results demonstrate that Kupffer cells are both significantly different and clearly distinct from endothelial cells. Kupffer cells have neither pores (and/or "sieve plates") nor fenestrations, all of which are present in endothelial cells. They possess a stellate shape, and only indirectly, with slender and irregular evaginations, contribute to the lining of the sinusoidal wall. Furthermore, the luminal surface in some areas contains a large population of short microvilli, microphicae and invaginations. These elements form a kind of microlabyrinth which may correpond to the "worm-like" structures described by transmission electron microscopy (TEM). In the present study, transition forms between endothelial and Kupffer cells were never found. On the contrary, considering the highly fenestrated nature of the endothelial cells, the Kupffer cells may, by ameboid movements, easily cross the overlapping barrier of the sinusoid and protrude into the lumen. Thus, acting as activated macrophages, the Kupffer cells might function to prevent the entrance of foreign material into the tissues of the liver through the fragile and highly fenestrated endothelium. Finally, the topographical reconstruction of the sinusoid by correlated SEM and TEM studies demonstrates the Kupffer cells, with their protruding cytoplasm and ability to extend into the lumen of the sinusoid, may actually change the caliber of the vessel, and thus function as a "sphincter" which causes a temporary arrest of the blood flow when the diameter of the sinusoidal lumen is reduced.


A karyometric and stereologic study of the effects of gonadotrophin and testosterone on the interstitial gland of the testis of intact and endoxan treated rats. Adult male rats were treated daily for 18 days with endoxan in doses of 4 mg/kg of body weight or testosterone in doses 2.5 mg per rat. For the last 5 days of the experiment some of the rats received gonadotrophin injections in doses of 50 I.U. Karyometric and stereologic studies were undertaken on paraffin sections of the testes stained with haematoxylin and eosin. Endoxan treatment decrease the nuclear volume of the Leydig cells and lowers the volume fraction occupied by the interstitial gland in the testis. These changes were accompanied by a decrease in the intensity of reaction for acid phosphatase, non-specific esterases and 3-beta-hydroxy-steroid dehydrogenase. Testosterone injected alone or jointly with endoxan resulted in more pronounced changes than following treatment with endoxan alone. As expected, gonadotrophin injections into intact rats resulted in a marked increase in nuclear volume of the Leydig cells and in the volume fraction of the interstitial gland. This effect of gonadotrophin on the interstitial gland of the rat testis was partially inhibited by endoxan treatment. It follows from these experiments that endoxan impairs the functional activity of the interstitial gland of the rat testes by lowering the endogenous gonadotrophin levels, as well as by direct action on the Leydig cells.


Urinary enzyme excretion during renal papillary necrosis induced in rats with ethyleneimine. N-Acetyl-beta-glucosaminidase, beta-galactosidase, beta-glucosidase, acid and alkaline phosphatase were monitored in urine kidney homogenates and serum of rats with papillary damage induced with ethyleneimine. Serum urea levels, total protein in the urine and urine volume were monitored throughout the study. Histological studies showed that the injection of ethyleneimine caused immediate papillary necrosis, followed later by secondary cortical involvement. Minor papillary necrosis induced by a low dose (0.5 mul/kg) of ethyleneimine was characterised by a rise in urinary N-acetyl-beta-glucosaminidase activity which was followed later by an increase in the activity of the other enzymes monitored. More severe papillary necrosis induced with a higher dose of ethyleneimine (5.0 mul/kg) resulted in an immediate rise in the activities of all the urinary enzymes which then decreased only to rise again when cortical involvement occurred. Serum urea was unaltered but urine volume and protein were increased coincidentally with the urinary enzyme activities. The value of the assay of urinary enzymes in distinguishing papillary from glomerular and tubular damage is assessed. The possible relevance of the ethyleneimine model to the  etiology of papillary nephropathy is discussed.


Heterogeneous distribution of DNA alkylation products in rat liver chromatin after in vivo administration of N,N-di[14C]methylnitrosamine. Poly-l-lysine (PL) binds to about 50% of chromatin DNA, rendering it resistant to degradation by DNAase I. Separation of the unbound DNA as acid-soluble nucleotides allows the fractionation of chromatin DNA into two zones. After in vivo administration of N,N-di[14C]methylnitrosamine, the amount of alkylation in DNA was found to be lower in the polylysine-binding regions. Some possible reasons for this heterogeneous distribution are discussed.


The effects of O-acetylsterigmatocystin and related compounds on rat liver and cultured chicken embryonal liver cells. Fine structural nucleolar changes induced in rat liver and primary tissue culture cells from 10-day-old chicken embryonal liver by O-acetylsterigmatocystin (AcO-stg), related compounds and aflatoxin B1 were compared. (1) Male Wistar rats were given a single i.p. injection of sterigmatocystin (stg), AcO-stg, and aflatoxin B1. 3 days after the injection of 15 mg/kg of stg, sporadic single cell necrosis was observed in rat liver, whereas rats treated with 8 mg/kg AcO-stg or more, and 3 mg/kg of aflatoxin B1 showed massive liver necrosis. Acetylation resulted in a marked increase in solubility in polar organic solvents. This increased solubility could play an important role in determining toxicity. (II) Treatment with the compounds with an unsaturateddelta1,2-furobenzofuranring system, such as AcO-stg, demethyl-diacetyl-stg (deMe-diAc-stg), and aflatoxin B1, resulted in nucleolar segregation and fragmentation of primary culture cells. Both parenchymal and mesenchymal cells in culture were susceptible to AcO-stg and deMe-diAc-stg, while the mesenchymal cells were more resistant to aflatoxin B1 than the hepatocytes. The inhibition of RNA synthesis in both cell types as determined in radioautography was in accordance with the electron-microscopic observations. Acetyldihydrosterigmatocystin (AcO-dihyd-stg), a saturated delta1,2-furobenzofuranring compound, was less toxic to primary tissue culture cells.


Histone modification in liver after administration of inducers of mixed function oxidase activity. The phosphorylation and acetylation of rat liver histones in vivo were determined after administration of phenobarbital or 3-methylcholanthrene. No changes were observed in the phosphorylation profile of histones separated by gel electrophoresis after treatment with either of these two inducing agents. However, after 2h of treatment with either phenobarbital or 3-methylcholanthrene, a significant increase in acetylation of histones was noted, particularly in the F2a1 and (F3, F2b, F2a2) regions. It is suggested that this increase which precedes the enhancement in RNA synthesis may play a role in the alteration of transcription in liver.


Studies on lung tumours. III. Oxidative metabolism of dimethylnitrosamine by rodent and human lung tissue. The oxidative metabolism of the carcinogen dimethylnitrosamine (DMN) was studied in mouse, rat, hamster and human respiratory tissue. [14C]DMN was purified by Dowex-1-bisulfite column chromatography to remove a contaminant (probably [14C]formaldehyde) interfering with the enzyme assay. Since formaldehyde and methyl carbonium ions - yielding methanol with water - are considered to be the primary products of DMN metabolism, tissue slices were assayed for the production of [14C]CO2 from 14C-labelled methanol, formaldehyde, formate, and DMN. Oxidation of formaldehyde to formate was not, but oxidation of formate to CO2 was very much rate-limiting. This rate-limiting step was circumvented by introducing quantitative chemical oxidation of formate to CO2 by mercury(II)chloride following the enzymic reaction. Since oxidation of methanol to CO2 proved to be insignificant, production of CO2 from DMN by lung tissue enzymes and HgCl2 may serve as a parameter for N-demethylating activity and the production of the suspected carcinogenically active methyl carbonium ions. The DMN-N-demethylating activities of lung tissue slices of two mouse strains with widely different susceptibilities to formation of lung adenomas by DMN differed significantly, but the difference seemed too small to explain the divergence in tumourigenic response. The enzymatic activities decreased in hamster bronchus, hamster trachea, hamster lung, GRS/A mouse lung, C3Hf/A mouse lung, human lung, Sprague-Dawley rat lung, in that order. The reported resistance of the hamster respiratory system to tumour induction by DMN may therefore not be due to poor DMN-N-demethylating capacity.


The biological fate in rats of vinyl chloride in relation to its oncogenicity. The main eliminative route for [14C]vinyl chloride after oral, i.v. or i.p. administration to rats is pulmonary; both unchanged vinyl chloride and vinyl chloride-related CO2 are excreted by that route and the other [14C] metabolites via the kidneys. After intragastric administration, pulmonary output of unchanged vinyl chloride is proportional to the logarithm of reciprocal dose. Excretion patterns after i.v. and i.p. injections are predictable from the characteristics of excretion following oral administration. Pulmonary excretion of unchanged vinyl chloride after oral dosing is complete within 3-4 h, but pulmonary elimination of CO2 and renal excretion of metabolites occupies 3 days. In comparison, 99% of a small i.v. dose is excreted unchanged within 1 h of injection; 80% within 2 min. The rate of elimination of a single oral doses of [14C]vinyl chloride is uninfluenced by up to 60 days' chronic dosing with the unlabelled substance. The distribution volume of vinyl chloride as displayed by whole-animal autoradiography agrees with deductions from excretion data. Small localization of 14C in the para-auricular region of appropriate sections occurs in sectioned tubules, belonging possibly to the Zymbal glands. Biotransformation of vinyl chloride into S-(2-chloroethyl) cysteine and N-acetyl-S-(2-chloroethyl) cysteine occurs through addition of cysteine, and biotransformation into: (i) chloroacetic acid, thiodiglycollic acid and glutamic acid, and (ii) into formaldehyde (methionine, serine), CO2 and urea is explicable in terms of an associative reaction with molecular O2 involving a singlet oxygen bonded transition state in dynamic equilibrium with a cyclic peroxide ground state. There is no evidence for chloroethylene oxide formation. Thiodiglycollic acid is the major metabolite of chloroacetic acid in rats; more than 60% of the dose. The interaction of vinyl chloride and of its primary metabolites with the intermediates of mammalian metabolism is discussed in relation to the oncogenicity of that substance.


Protein chain initiation in vitro by liver cell components from DMNA-treated rats. The mechanism of inhibition of protein synthesis in rat liver after dimethylnitrosamine (DMNA) administration was studied at the level of peptide-chain initiation by use of initiation-dependent amino acid incorporating systems. Ribosomal monomers, poly(A)-concontaining loss of acticity due to the DMNA treatment. The poly(A) RNA from monosomes and polysomes, and crude initiation factors from microsomes were prepared 2 h after a single dose of DMNA (75 mg/kg), and their activities in the production of new protein chains determined under conditions of nearly linear response. Monosomes and crude initiation factors from DMNA-treated rats were at least as active as those from controls. Preparations of poly(A)-containing RNA had a consistently higher template activity when prepared from polysomes instead of monosomes. However, in neither case was there any ltaining RNA was methylated by DMNA to about the same extent as the 18S and 28S rRNA. The methylation was consistently somewhat higher in the RNA preparations from monosomes than in those from polysomes.


Evidence for a second arylhydroxamic acid acyltransferase species in the small intestine of the rat. The small intestine of the Sprague-Dawley rat has been shown to contain two species of arylhydroxamic acid acyltransferases. These enzymes were separable by gel filtration on Sephadex G-100. The smaller species had the mobility of rat liver acyltransferase and was precipitated with antiserum directed against the liver enzyme. The larger species was not precipitated with this antiserum. These species differ in their relative abilities to utilize N-hydroxy-N-2-acetylaminofluorene (N-hydroxy-AAF) and N-hydroxy-N-4-acetylaminobiphenyl (N-hydroxy-AABP) as substrates, and in their inhibition by non immune serum.


A reliable method for the simultaneous estimation of dopamine, noradrenaline and serotonin in discrete areas of brain. 1. Sub-microgram levels of dopamine (DA), noradrenaline (NA) and serotonin (5HT) were estimated simultaneously in small discrete areas of brain by a simple combined alumina adsorption-spectrofluorometric technique. 2. The method does not depend on the use of ninhydrin which is reported to interfere with the spectrofluorometric assay of 5HT nor does the method involve the use of phosphate buffers which reportedly are a source of error in catecholamine assays. 3. The method described is suitable for the measurement of amine levels both in normal conditions and when amino levels have been severly reduced by amine-depleting drugs. Neither reserpine nor alpha-methyl-p-tyrosine interfere in the assay.


Plasma free amino acids in the chronically uremic rat. Plasma free amino acids in the sub-totally nephrectomized chronic uremic rat have been quantitated. The concentrations of these substances in uremic rats have been compared to levels present in sham-operated controls, and to levels found in normal rats on a restricted diet. Phosphoserine, alpha-aminoadipic acid, 1-methylhistidine and 3-methylhistidine concentrations were found to be significantly higher in the uremic group. Sub-normal amounts of serine, valine, tryptophan, asparagine and anserine were present in the serum of the uremic animals. No changes were detected in serum amino acids which are ketogenic. Serum glutamic oxaloacetic transaminase activity was reduced in both uremic and restricted diet rats.


Uric acid estimation: a comparison of the manual uricase-UV and the phosphotungstate auto-analyzer methods. 1. Uric acid estimations by the uricase-UV and the autoanalyzer colorimetric procedures were compared. 2. At all levels of serum uric acid concentration measured, results with the uricase-UV method were significantly lower than those with the phosphotungstate method. 3. The data indicate that the critical uric acid level (measured by the autoanalyzer) at which allopurinol, uricosuric, and other agents are instituted should be decreased approximately 10 per cent when determinations are done by the uricase method.


The human hemoglobin variants in Canada. This report summarizes the results of a search for abnormal hemoglobin variants by use of a filter paper electrophoresis technique on 228,300 blood samples obtained from various parts of four Canadian provinces. Abnormal variants were found in 438 samples and were of 27 different varieties, including six new ones. In addition, the characteristics of beta-thalassemia were found in 147 samples. The types of variant found, and their geographical and ethnic origin are presented.


Systolic time intervals in thyroid disease. The systolic time intervals; total electro-mechanical systole (QS2), left ventricular ejection time (LVET), pre-ejection period (PEP), and ratio of PEP/LVET were measured from external readings in twenty hyperthyroid and fifteen hypothyroid patients. The hyperthyroid subjects showed shortening of the PEP and reduction in the PEP/LVET. The hypothyroid group showed lengthening of the PEP, shortening of the LVET and increased PEP/LVET. These changes returned towards normal in ten patients rendered euthyroid with appropriate therapy. The value of these measurements to predict the thyroid status was examined in a mixed group of seventy-four patients. There was close agreement between diagnosis predicted from systolic time intervals and that made independently from clinical and biochemical assessment, suggesting that the systolic time intervals may have been a useful place in the clinical assessment of thyroid patients.


Leucocyte chemotaxis: physiological considerations and abnormalities. Expression of the inflammatory process is dependent on mobilisation of leucocytes, which require leucocyte chemotaxis. Recent technological advances have enabled extensive in vitro biological characterisation of the chemotatic stimuli (factors) and the cellular events of migration. The chemotatic stimuli include products of complement activation, fibrinolytic and kinin generating systems, collagen products as well as products of bacterial growth and products released from virus-infected tissues. Chemotatic factors are also released as a result of lymphocyte activation and phagocytosis by neutrophils. Other neutrophils products released during phagocytosis activate the complement system. A complex mechanism for limiting production or activity of chemotactic factors has been identified. These antichemotatic agents include serum and cell-derived chemotactic factor inactivators as well as specific inhibitors of leucocyte migration and complement inactivators released from neutrophils during the phagocytic process. The mechanism by which cells respond to chemotatic factors is poorly understood by cell adherence to the substratum, cell deformability, random migration, and directed migration are required. These processes are complex and require modifications of the leucocyte surface, calcium and magnesium, activation of esterases, function of contractile elements and assembly of a cytoskeleton, which is probably modulated by cyclic nucleotide metabolism.


Microbe ingestion and killing by neutrophils: normal mechanisms and abnormalities. Microbial ingestion and killing by neutrophils involves the interaction between the phagocytic cells of the body and certain serum factors. The primary phagocytes of the blood are the polymorphonuclear neutrophil, eosinophil and monocyte. The fixed tissue macrophage of the reticuloendothelial system is responsible for phagocytosis and killing of encapsulated bacteria, viruses, and protozoans, whereas the blood phagocyte system is involved in killing of pyogenic bacteria and certain fungi. Proper ingestion of bacteria requires opsonisation of these bacteria by either complement of specific antibody, or an interaction of these two proteins. Opsonised bacteria are fixed to the surface of the phagocytic cells which contain receptors for IgG and C3. Following immune adherence ingestion of bacteria involves invagination of the plasmalemmal membrane. This process utilises ATP and a re-arrangement of lipids occurs during formation of the phagocytic vacuole. Granular enzymes containing peroxidase, hydrolases, and cationic proteins are transferred from the granule into the phagocytic vacuole. There is activation of oxidative metabolism with an increased consumption of oxygen leading to hydrogen peroxide production.


A prospective clinical trial of post-operative radiotherapy delivered in three fractions per week versus two fractions per week in breast carcinoma. The results are presented of a five-year prospective trial of 411 patients with breast carcinoma treated by mastectomy and post-operative radiotherapy. Twice or thrice weekly dose-fractionation techniques were used, i.e. 12 fractions in 28 days and six fractions in 18 days. The results show that, in terms of survival and control of local disease, the two techniques are very similar. The early and late radiation effects on the normal tissues up to five years are similar and acceptable. Dose levels thought to be biologically equivalent on the basis of experience at St Thomas's Hosiptal were selected. It is stressed that there is a narrower margin of normal tissue tolerance when six fractions over 18 days are used, that it is essential to treat all fields on each treatment occasion and that the total maximum tissue dose of 3600 R is not exceeded. Attention is drawn to the fact that the dose for six fractions, derived from the NSD formula which would be predicted to be equivalent to the 12-fraction dose is, in fact, over 10% higher than the dose used here and likely to produce unacceptable late radiation changes.


The accuracy of radiological diagnosis of benign, primarily and secondarily malignant gastric ulcers and their correlation with three simplified radiological types. Two radiologists individually gave 'blind' diagnoses of benignancy or malignancy to 145 radiographic representations of gastric ulcers, all with gastrectomy histological proof of benignancy or malignancy. A radiological diagnosis of malignancy was shown to be 98-6% reliable. A diagnosis of benignancy was less reliable (85-4% true positives) but this was a surgical series containing thereby an abnormally high proportion (over a third) of malignant ulcers. A correct diagnosis was mde in 99-5% of the proven benign ulcers, but in only 68-6% of the proven malignant ulcers. Analysis of the pathology reports on the malignant ulcers has shown that it was mainly those arising on the basis of pre-existing benign ulcers (i.e. secondarily malignant ulcers) that were wrongly diagnosed radiologically, thus suggesting that they have fundamentally different radiographic appearance from that of primarily malignant ulcers. It was then found that the ulcers could be divided into three simplified radiological types based on their in-profile appearances: type 1 (projecting), type 2 (intraluminal) and type 3 (so shallow as to be neither projecting nor intraluminal). Statistical association with the histological types led to the following conclusions: (a) radiological type 2 or 3 ulcers should be diagnosed as almost certainly malignant (usually primarily malignant) and (b) radiological type 1 ulcers are almost always benign but should be followed up until healed because the rare secondarily malignant ulcers are also usually of this type.


The radiology of the subtalar joint with special reference to talo-calcaneal coalition. Congenital talo-calcaneal coalition is one of the conditions responsible for spastic flat foot. The common site is across the middle talo-calcaneal joint, and although routine radiographic views of the foot do not show the coalition, important secondary signs may be present. The findings in 17 cases are reviewed, the following secondary signs being recognised: 1. A talar beak. 2. Narrowing of the posterior talo-calcaneal joint space. 3. Rounding of the lateral process of the talus. 4. Failure of visualisation of the middle subtalar joint in the lateral view, and 5. Asymmetry of the anterior subtalar joints in the lateral oblique vies. The differential diagnosis of these signs is discussed and the normal anatomy of the subtalar joints is illustrated. Some diagnostic pitfalls are described.


Pigmented villo-nodular synovitis: bone involvement of the fingers. Pigmented villo-nodular synovitis may occur in either diffuse or nodular form. In the latter the fingers are the commonest site to be involved. The disease is rare, and in only 15% is there bone involvement. Two cases showing bone involvement of the fingers are presented. One of the cases (Case 2) adds radiological support to the theory of Scott (1968), based on pathological studies, that suggested that the bone changes are due to invasion by the villo-nodular tissue through and along the nutrient foramina. The site of these bone changes appears sufficiently typical to be a radiological diagnostic aid. The differential diagnosis of the radiological appearances of the disease in the digits is discussed.


Radiological features of the skull in Klinefelter's syndrome and male hypogonadism. Skull radiographs were performed in 21 cases of Klinefelter's syndrome and in 30 cases of eunuchoidism. The radiographic changes of the skull in Klinefelter's syndrome are: temporal flattening, decreased width of the vault, narrowing of the mandible, decreased length of the skull, shortening of the anterior fossa cranii, decrease in the angle of the base, thinning of the vault bones at the major fontanelle, premature and excessive calcification of the coronal suture, deepening of the posterior fossa and shortening of the mandibular rami. In hypogonadotropic eunuchoidism the skull radiographs show: small mastoid processes, fine bones of the vault, small sella turcica, club-shaped clinoid processes, excessive development of sphenoidal sinuses and in the fourth and later decades of life a diminished bone density (osteoporosis).


The skull in gonadal dysgenesis. A roentgenometric study. Skull radiographs of 54 patients with Turner's syndrome have been studied. The following characteristic findings were frequently noted: mastoid processes of definitely decreased dimensions, small facial bones which were proportional to the stunted growth of the patients, enlargement and increased thickness of the mandible, extensive calcification of the petro-clinoid ligaments, excessive pneumatisation of the paranasal sinuses and increased angle of the base of the skull.


Angiography of high cervical extramedullary tumours. Vertebral angiography was performed in two cases of extramedullary tumour of the upper cervical spine. The technical feasibility and relatively low risk of catheter vertebral angiography makes it a useful procedure to be performed in addition to myelography in the pre-operative evaluation of such lesions. The information thus obtained includes the relationship of the tumour to the vertebral arteries and other vital structures, demonstration of the blood supply, and evidence as to tumour type.


Massive unilateral non-functioning hydronephrosis in horseshoe kidney. The occurrence of non-function in one half of a horseshoe kidney resulting from hydronephrosis can, if unrecognized, create a serious surgical as well as medical problem. The anterior position of the ureter in relation to the isthmus, as well as strictures and accessory vessels increase the incidence of hydronephrosis, which if severe enough, can go on to non-function. The key diagnostic factor is the observation of the visualised side, which shows the characteristic malrotation of the calyces and the deviation of the long axis of the kidneys; these are associated with a mass effect on the obstructed side, with or without a 'crescent' sign. Five cases of this unusual occurrence are presented.


The radiological diagnosis of analgesic nephropathy. A study was made of the radiological findings in 57 patients with a clinical diagnosis of analgesic nephropathy. The ages of the patients ranged from 27 to 72 years, and females predominated over males in the ratio 4-7 to 1. Renal failure varied from mild to very severe and the patients showed the usual high incidence of analgesic-induced gastro-intestinal, haematological and neurological disorders. In 82% of cases, kidneys were of normal size, but there was radiological evidence of reduced renal function in 85%. Thus, a small kidney with good renal function was unlikely to be due to analgesic nephropathy. Medullar necrosis was observed in 65%, and papillary atrophy and papillary necrosis each in 46%. Although usually gradual, acute massive sloughing of necrotic papillae could occur and occasionally led to ureteric obstruction. Papillary cavitation was seen in 39% but fistulae and ring shadows were observed in only 11% and 14% respectively, while renal calcification occurred in 26%. With the use of high dose techniques and retrograde pyelography, it is almost always possible to make a positive radiological diagnosis of analgesic nephropathy, even in patients with markedly reduced renal function.


Variations in bronchial movement.

Variations in bronchial movement. Studies of bronchial movement in bronchi and bronchioles following routine bronchography are presented with the aid of a magnification technique. Wide variations of calibre were demonstrated on full inspiration and extreme expiration, most marked in the smaller bronchi. During coughing, maximal differences of width were noted in the larger airways, with little change in the smallest bronchi. In order to assess the changes, reference is made to previous records when, using a three-channel writing oscillograph, bronchial measurements, intra-oesophageal pressures and lung volumes were estimated. Critical examination of the borders of the bronchial walls revealed that they were never straight nor truly parallel. They had smooth, undulating outlines, which were seen to alter on serial films. Irregularities in the airways without disease can be considerable, but when destructive changes are present, gross deformities may become apparent. With a full inspiratory effort, bronchial walls may be completely extended and appear normal, but on radiographs taken on expiration weakness of the bronchial wall may be revealed which otherwise would be missed. The inclusion of routine expiratory films on all bronchographic examinations is recommended.


The chest radiograph in ankylosing spondylitis. In a study of 42 patients with ankylosing spondylitis, upper lobe fibrosis was present in six (14-3%) patients. All the patients with upper lobe fibrosis had total spinal ankylosis, and half showed peripheral joint involvement. A further 13 patients (30-9%) had other focal pulmonary abnormalities compared with only six (14-3%) of a group of age-matched controls. There was no correlation between the radiological extent of the disease (spinal changes and pulmonary involvement) and any of the haematological or biochemical parameters measured. Treatment with radiotherapy was not responsible for these changes.


Pulmonary lesions due to opportunist mycobacteria. (Review includes 30 cases of M. kansasii infections). The apparent increase in the incidence of opportunist mycobacterial pulmonary infection is assessed. The clinical, bacteriological and radiological characteristics of 34 cases of such infections seen over a period of ten years in Sheffield are reviewed. The typical radiological appearances consisting of cavities, fibrosis and opacities are described and illustrated. There has been in the past conflicting reports on the specificity of such radiological features; it is concluded that although such appearances are not pathognomonic, their presence should arouse suspicion of such an infection and this should be confirmed or refuted by bacteriological investigations.


Localised aneurysms of the descending thoracic aorta. The clinical, roentgenographic and aortographic data were reviewed in 12 patients with localised descending, thoracic aortic aneurysms. The current study indicates that arteriosclerotic peripheral vascular disease not infrequently produced localised saccular aneurysms of the descending thoracic aorta. Characteristic symptomatology was unusual; most aneurysms were detected as incidental roentgenographic findings. The aneurysms projected from the posteroloteral aspect of the aorta and roentgenographically appeared as left hilar masses or left retrocardiac masses when located in the mid and lower descending thoracic aorta, respectively. Specific rim calcification or vertebral erosion was not encountered in any case. During aortography only a small portion of the aneurysm was outlined with contrast material due to partial obliteration of the aneurysmal cavity with thrombus.


Migration of epicardial pacemaker leads. The implantation of permanent pacemakers often gives rise to complications. Migration of leads, an unusual complication, occurred in two of our patients with epicardial pacemakers. In one case lead fracture and sussequent displacement due to heart action occurred after an automobile accident. In the second case looping and migration of the wire occurred within a day after implantation although the lead continued to function properly for six months. The probable cause of migration in this patient was excess slack.


The effect of penta-gastrin and cholecystokinin on radiological gastro-oesophageal competence. Fourteen patients with clinically obvious gastro-oesophageal reflux were examined by conventional barium meal radiology. Neither exogenous penta-gastrin nor cholecystokinin appeared to influence the radiological competence of the gastro-oesophageal junction in ten of thos patients. The remaining four patients were used as controls and normal saline was injected instead of the active preparation. Radiological competence was unaffected. The significance of these findings is discussed.


Multifocal carcinoma of the large intestine. Five cases of multifocal carcinoma of the large intestine are described, including one multifocal recurrence, the only one described in the literature. All of them were recognised radiologically before operation. The importance of a thorough examination of the whole colon in suspected cases is stressed, even when a single lesion has been demonstrated.


Sequential liver and biliary tract scanning with 131I labelled Rose Bengal. 131I labelled Rose Bengal is offered as an aid for estimating the functional state of the liver, gall bladder and patency of the biliary tree. When the tracer is injected intravenously, it is cleared from the blood by the polygonal cells of the liver, excreted into the bowel and discharged into the duodenum. The equipment used was a gamma camera and small digital image processing system with area of interest capability. The diagnostic criteria used were those of blood retention, maximum hepatic uptake, liver, gall bladder and biliary tree visualisation times and time of excretion into the duodenum. Preliminary results from the findings in 60 patients of whom 42 were jaundiced are presented to demonstrate the ability of the technique to disclose evidence indicating intra- or extrahepatic causes of jaudice. Of 33 patients with proven extrahepatic obstruction Rose Bengal scanning provided the correct evidence in 31 cases, the other two having intermittent obstruction by common bile duct stones. Of the 12 patients with proven diffuse parenchymal disease the technique disclosed the correct evidence in all cases. All four post-cholecystectomy patients with recurrence of symptoms showed good visualisation of the duct system and excretion into the bowel.


Correlation of intra-arterial contrast stasis with flow patterns at constrictions, branches and bends: an experimental model. Flow patterns at bends and branches have been studied in an easily constructed open channel model so as to determine whether zones of stasis and poor mixing at constrictions, bends and branches can be correlated with certain arteriographic appearances. At bends, spiral flow lines and static zones occur which resemble those seen occasionally in the aortic arch and carotid siphon. At branches, stasis occurs on the outer walls of the branch mouths both in the experiments and arteriography, and constrictions easily produce downstream stasis, previously demonstrated in both arteries and open-channel experiments. Upstream stasis, not previously recorded, can also occur in arteries and model associated with severe constrictions. Occasionally stasis may extend along the whole length of one wall of a vessel when there is a downstream constriction, resembling arteriographic appearances seen in the internal carotid artery in patients with raised intracranial pressure, in those undergoin hyperventilation and also in coronary and other arteries. Despite known rheological differences between blood and water, the experimental findings are thought to be meaningful, and to indicate that there are within arteries, areas where turbulent mixing forces are weak or absent, resulting in arterial stasis.


Vulval phlebography in the pelvic congestion syndrome. Twelve patients referred to a general surgeon with special interest in varicose veins were found to have vulval varices. All the patients were considered to be suffering from the pelvic congestion syndrome. Their radiological investigation by percutaneous vulval phlebography is described. It is suggested that patients with vulval varices should be examined radiologically by percutaneous vulval vein injection of contrast medium. It is postulated that pelvic vein thrombosis may precipitate the pelvic congestion syndrome. Whereas there is no established treatment of this syndrome, the radiological examination has proved helpful in planning the treatment of these patients.


The appearances of artefacts on lower limb phlebograms. The various artefacts that may be encountered in phlebograms and which may be confused with thrombus are described. Methods of avoiding these pitfalls are discussed. the conclusions are based on over 2500 phlebograms carried out for suspected deep vein thrombosis.


Large subarticular cysts (geodes) adjacent to the knee-joint in rheumatoid arthritis. Two patients with rheumatoid arthritis are described, who developed very large bone cysts or geodes adjacent to the knee-joint. The existence of cysts adjacent to joints involved by rheumatoid arthritis is well recognised, but the occurrence of very large cysts is unusual and may present diagnostic difficulties. Possible aetiological factors are discussed.


Choroidal metastases from breast carcinoma: a survey of 42 patients and the use of radiation therapy. Visual disturbances in patients with breast carcinoma may result from choroidal metastases. Metastases were bilateral in 41% of patients and the choroid was the first site of metastasis in 25%. Therefore awareness of this 'rare' condition is essential for any doctor seeing patients with breast cancer; consultation with an ophthalmologist and radiotherapist is mandatory. Radiation therapy is the treatment of choice, producing an 80% response rate (complete resolution in 25%). The final catastrophe of blindness in these patients can be prevented.


Initial experience with a small dedicated computer system in a diagnostic x-ray department. The operation of a small computer system involved in day to day management in an X-ray department is described. The system consists of the following equipment: PDP 8/F central processor with 8K core storage, 32K magnetic disc storage, High-speed paper tape reader (300 characters/s) and punch (50 characters/s), 3 Olivetti TE318 terminals with sprocket feed, paper tape reader and punch (10 characters/s). The system stores patient data relating to name, address, age, ward, referring physician, examination(s) requested, date of request, date of examination, date of report. From this data a large volume of relevant statistics is made available to the department and to the health authority. Labels for identifying record card, film envelope and X-ray films are automatically typed. During reporting coded phrases can be used by the radiologist. Interesting films can be recorded and recalled for library or consultation purposes as can research items. At report typing stage, the report heading is automatically recalled from the computer store. Coded phrases are typed automatically as is the radiologist's name and the date of the report. A 'DAYBOOK' IS TYPED AUTOMatically at the end of each working day. Problems encountered in running the system and future developments are described.


A general program to estimate gene-frequencies by the method of maximum-likelihood. The program estimates the optimal gene-frequencies from observed values of phenotypes by the method of maximum-likelihood. The program does not make assumptions about a specific blood-group-system. This information has to be supplied by input cards. A straightforward iteration process is used for obtaining initial estimates for the gene-frequencies in question. Then an iterative application of the Newton-Raphson method is used to solve the maximum-likelihood equations. The program yields the gene-frequencies and their standard deviations, expected values of the phenotypes, expected values of the genotypes. Finally the chi-square between observed frequencies and (optimal) expected values of phenotypes is computed.


A conversational program for analytical modelling of action potentials in nerve and muscle. A conversational program is described which is being used for exploratory modelling of digestive tract electrical activity. The structure of the mathematical model is based on the Hodgkin-Huxley equations for nerve axons and the Noble equations for Purkinje fibres of the heart. The parameters of the models are changed conversationally to investigate the effects of frequency, amplitude and waveshape. In this way it is intended to extend the models to include nervous control. The program is also being used to correlate the behaviour of H-H type equations with the simpler dynamics of Van der Pol's equation which is the basis of an oscillator-array model for the stomach and small intestines.


A set of fortran subroutines for optimizing radiotherapy plans. Quadratic Programming techniques have been applied to the optimization of radiation field weighting in Radiotherapy planning. Wedge selection has also been included by means of an exhaustive search. The radiation dose at any point in the patient may be constrained to be less than a stated percentage of the tumour dose. The routines have been successfully interfaced into a small computer interactive planning system, but they could represent an even more powerful tool in batch and time sharing systems. Minimum operator intervention is required in their use.


Application of a programmable pocket calculator to a single compartment mathematical model of solute kinetics. A single compartment mathematical model has been applied to kinetics of small solutes (urea and creatinine) in dialysis therapy. The model can be described by two equations requiring iterative solution of calculated values, given several measurable variables. The equations have been programmed onto a Hewlett-Packard 65 pocket calculator and recorded on 3 X 1/2" magnetic strips, facilitating clinical application to dialysis therapy.


Hemodynamic patterns in shock and critically ill patients. Nine variables were studied in 56 patients to analyze hemodynamic patterns of critically ill and shock patients. The variables were central venous pressure, mean arterial pressure, heart rate, cardiac index, left ventricular stroke work, strok index, total peripheral resistance, arteriovenous oxygen difference, and oxygen consumption. We observed six patterns; three with low cardiac index (hypodynamic) and three with high cardiac index (hyperdynamic). Group IA: Low cardiac index with increased central venous pressure and arteriovenous oxygen differences associated with myocardial infarction, cardiac insufficiency, and postoperative cardiac surgery: Group IB: Low cardiac index with normal arteriovenous oxygen difference associated with myocardial infarction or hypovolemia. Group IC: Low cardiac index and decreased arteriovenous oxygen difference in patients with hypodynamic septic shock. Group IID: High cardiac index and increased arteriovenous oxygen difference in patients with sepsis and stable hemodynamic conditions. Groups IIE and IIF: Increased cardiac index and normal or increased arteriovenous oxygen difference in septic patients, who were hemodymamically unstable or in shock. These hemodynamic observations were found to be useful for understanding physiological compensations, for deciding on therapy, and in evaluating the effectiveness of therapy.


Preferences of infants for regular and distorted facial stimuli. Kagan (1970a) and Lewis (1969) have proposed that infant preferences for regular and distorted face stimuli are determined by schema development. In order to test the schema model's predictions of infant preferences, changes in the methodological and statistical procedures of past research are necessary. Infants 3-14 months of age were tested for facial preferences using an operant response. The Coombs analysis showed that the predicted age changes in preferences for facial organization were not found. The preference data were interpreted as being based on stimulus variables other than the realism variables hypothesized by schema-model theorists.


The relation between nonnutritive sucking and visual information processing in the human newborn. This paper considers the relation between visual information processing and the burst-pause pattern of nonnutritive sucking in the human infant. Sucking and visual scanning activity were investigated in 2 independent studies. The results did not support the view that sucking is affected by ongoing processing activity. It is argued that previously reported effects of processing on sucking reflect a phasic component of the orientation reaction (OR) to stimuli, not a sustained processing of those stimuli. Additionally, no existing evidence supports the idea that the components of the natural burst-pause pattern of sucking differentially affect information processing in the human newborn.


The therapeutic intervention scoring system. An application to acutely ill cancer patients. The Therapeutic Intervention Scoring System (TISS) has been introduced (Cullen DJ, Civetta JM, Briggs BA, et al: Therapeutic intervention scoring system: A method for quantitative comparison of patient care. Crit Care Med 2:57-60, 1974) at the Massachusetts General Hospital as a means of quantifying the medical and nursing care required by critically ill patients. The method has been instituted in the Intensive Care Unit of Memorial Cancer Center to evaluate its applicability to patients who develop life-threatening complications of their disease or its treatment. This is a preliminary report of the system's use in 55 consecutive patients who averaged 33.4 intervention points per day. This average compares closely with that of postcardiac surgery patients (31.8 points), the group that required the most care of all patients in the initial study. The results indicate the usefulness of this sytem in evaluating severity of illness, predicting survival, and assessing cost benefits. It has proven to be a simple and accurate method of assessment when simple and accurate method of assessment when applied to this patient population, but certain modifications seem warranted and have been suggested herein.


Perceptual training of height and brightness seriation in kindergarten children. A study of seriation was conducted from the perspective of Gibson's theory of perceptual development. Kindergarten children who evidenced little seriation of height or brightness were assigned to either 1 of 3 perceptual training conditions or to a fourth, control condition. Training consisted of nonreinforced same-different judgments to wooden dowels varying in height, or in brightness, or simultaneously in height and brightness. The theoretical rationale for this training was that it would facilitate perception of the stimulus dimension(s) on which the dowels differed. It was found that perceptual training did facilitate seriation, particularly if both the height and brightness dimensions varied simultaneously in training.


Experience with a multidisciplinary critical care center in a community hospital. A multidisciplinary intensive care unit has been developed in a community hospital by planning techniques which are still not common in the hospital development environment. The resulting Acute Care Center has special attributes, especially in ongoing professional educational and consultation support, in continuous physician staffing aroung the clock, in equipment and in operational policies. The net result appears to be the provision of a higher standard of patient care, a lower mortality rate for the critically ill patient, and various cost benefits. The concepts and policies involved are being met with increasing acceptance in the local medical community.


Critical care problems of the newborn: insensible water loss in small premature infants. During the control period in this study, small premature infants, 1500 g in birth weight, had insensible water loss (IWL) of 2.28 g/kg/hr (equivlaent to 54 ml/kg/day), which is considerably higher than in full term infants. Under phototherapy, there was a significant increase in IWL (3.14 g/kg/hr) associated with increase of skin and rectal temperature. The heart rate and respiratory rates were comparable. Full term infants in stress situations such as phototherapy can compensate for water losses by increasing oral intake. In small premature infants, reliance must be placed upon increased amounts of parenteral fluids when under phototherapy.


Development of gender constancy and selective attention to same-sex models. 4 developmental levels of gender constancy were identified in 55 preschool-age children on the basis of a reproducible Guttman scale of answers to sets of questions pertaining to gender identity, gender stability over time, and gender consistency across situations. Children's developmental level of gender constancy was predictive of the amount and the proportion of time they attended to an adult male and an adult female film model. As boys developed gender constancy, their relative preference for watching the male model increased significantly; as girls developed gender constancy, their relative preference for watching the female model increased, though not significantly. At the more advanced levels of gender constancy, boys watched the male model more than did girls. It was suggested that same-sex social learning may develop as a function of children's cognitive understanding of gender as an identifiable, stable and consistent human attribute.


The function of shifting fixations in the visual perception of infants. The processes underlying infants' shifts of fixation from 1 stimulus to another were explored in 3 studies. The results suggest that infants 3 months and older shift more when the 2 stimuli of a pair are similar than when they are different. Shifting is affected by stimulus repetition as well. There were age differences in the number of shifts per trial, with older infants shifting more. The possibility that shifting may facilitate stimulus recognition is discussed.


Effects of varying laboratory conditions on behavioral-state organization in two- and eight-week-old infants. Previous studies have found that laboratory conditions influence sleep-waking behavior in older infants, children, and adults. The present study employed videotape recordings to monitor continuous 24-hr sleep-waking activity in 2- and 8-week-old infants before, during, and after 12 hr of polygraphic recordings. Sleep- and waking-state organization were affected by laboratory conditions. At both age levels, increased fussy-crying and decreased alertness occurred during the first 4 hr in the laboratory when they were video recorded only and during the first 4 hr that the leads were in place. Decreased fussy-crying and increased alertness were noted in the following periods, indicating adaptation. Latency to sleep was shorter, and drowsiness increased and active sleep decreased while the leads were in place. At 8 weeks, quiet sleep increased and active sleep decreased while the leads were in place. These data suggest that the unfamiliar laboratory conditions inherent in both observational and polygraphic studies are stressful and that time for adaptation is needed.


Behavior of narcotics-addicted newborns. The behavior of narcotics-addicted and nonaddicted newborns on the first 2 days of life was assessed with the Brazelton Neonatal Behavioral Assessment Scale. In addition to classic signs of narcotics abstinence, addicted infants were less able to be maintained in an alert state and less able to orient to auditory and visual stimuli. These deficits were especially pronounced at 48 hours of age. Addicted infants were as capable of self-quieting and responding to soothing intervention as normal neonates, although they were substantially more irritable. These characteristics and addicted infants' greater resistance to cuddling are discussed in terms of their potential impact on early infant-care-giver interaction.


Children's use of motives and intentionality in person perception and moral judgement. Preschool, second-, and fifth-grade children watched films and heard stories which portrayed an actor who intentionally or accidentally injured another for either good or bad motives. After each film or story, children were interviewed to determine their understanding of the actor motives and the intentionality of his act and their moral judgements. The results suggest that children of all ages understood the concepts of motive and intentionality, but that the ability to make accurate inferences about motives and intentionality develops with age. Motives affected children's evaluations at all ages, but intentionality affected only grade school children's evaluations. The results for moral judgment were discussed in terms of a theory which included features of both cognitive-developmental and social learning explanations of moral development.


Perceptual discriminability and communication performance in preschool children. The ability of preschool children to discriminate perceptually among novel forms frequently employed in referential communication tasks is examined. Results suggest that preschool children who are able to discriminate among the forms nevertheless perform poorly on a referential communication task involving these same forms. Asking children to provide names for the forms enhanced their discrimination performance but not their communication performance.


A test of the poor leader-member relation cells of the contingency model on elementary school children. The problem was to investigate the 4 poor leader-membrane relation cells of Fiedler's contingency model on fourth-grade elementary school groups. High and low least-preferred co-worker (LPC) leaders with strong and weak power were compared on structured and unstructured group tasks. When the task was structured, high LPC leaders were more effective than low regardless of position power. For the unstructured task, high LPC leaders were more effective than low for strong position power on 2 of 4 measures used, while low LPC leaders were more effective than high for weak position power on 1 of 4 measures.


Intentionality, degree of damage, and moral judgments. 153 first graders were given Piagetian moral judgment problems with a new simplified methodology as well as the usual story-pair paradigm. The new methodology involved making quantitative judgments about single stories and examined the influence of level of intentionality and degree of damage upon absolute punishment ratings. Contrary to results obtained with a story-pair methodology, it was found that with single stories even 6-year-old children responded to the level of intention in the stories as well as the quantity and quality of damage involved. This suggested that Piaget's methodology may be forcing children to employ a simplifying strategy while under other conditions they are able to perform the mental operations necessary to make complex moral judgments.


Developmental differences in children's preferences for high- and low-arousing forms of contact stimulation. In a 2-choice preference situation involving the availability of adult-administered cuddling versus tickling stimulation, overall preferences for cuddling steadily decreased across 4 groups of children from 3 to 7 years of age. This developmental decrease was most prevalent, for both boys and girls, when the contact agents were a female cuddler versus a male tickler. The reversal of these contact-sex roles (female tickler vs. male cuddler) did not affect the developmental preference for less cuddling stimulation of the 3 oldest groups of girls; however, the youngest girls now avoided male cuddlers, while the boys were found to prefer male cuddlers at all 4 age levels.


Dimensional salience and judgments of bigness by three-year-old children. 3-year-olds were shown triads of rectangles and asked to select the "big" one, where the biggest rectangle in each triad was neither the tallest nor the widest. Dimensional salience and response choice were highly related. In addition, as saliency of a particular dimension increased relative to the other dimension, significantly more responses were based on that dimension. The results support the notion that the young child does not rely on 1 specific dimension to make judgments of bigness but, rather, attends to the most salient differences among stimuli.


Visual information-processing speed in reflective and impulsive children. A backward-masking procedure was used to measure the rate of visual information processing in 8- and 10-year-old reflective and impulsive children. The test stimulus (TS) and the masking stimulus (MS) which followed it were presented tachistoscopially. The subject's information-processing threshold was defined as the next highest TS-MS interval above the interval where at least 3 of the 4 TSs were incorrectly identified. Reflective children were significantly faster than impulsive children at processing information. This finding was related to research indicating that reflective and impulsive children employ similar cognitive strategies; it was suggested that performance differences between these children might be related to reflective children employing their strategies with more adequate information.


[Indications and surgical technic for the correction of funnel chest and its results]. Treatment of funnel chest is only successful by surgical means. 425 funnel chest operations have been performed between 1956 and 1974 at the Surgical and Paediatric Surgical Department of the University Erlangen-Nürnberg. Different types of operative procedures have been compared with each other. The internal fixation of the elevated funnel chest with a metal strut is an operative procedure with the lowest infection rate, with less recurrences and the best anatomical and cosmetic results. The surgical procedure involves a double incision of the ribs parasternally and at the borderline of the funnel, the mobilised ventral part of the chest is elevated by a metal strut to an anatomically normal position. 235 patients have been operated on by this method. In 7% a local wound infection occured, there was one total recurrence and 15 partial recurrences. 4 years after operation 75% of the patients had an anatomically normal and well developed chest with an excellent cosmetic result.


[Clinical picture and treatment of carcinoid of the appendix]. The clinical syndrome of a carcinoid tumor of the appendix is presented in 7 such cases. In spite of its slow growth and late metastatic dissemination iliocoecal resection must be performed dependent on the extent and location of the tumor.


[Injuries of the rectum in barium contrast enema]. Perforation of the rectum during a barium enema can be catastrophic. Most reports and in our experience too, the lethality in these patients is more than 50%. This effect of barium is not widely appreciated. Injections of barium sulfate with faeces, of commercial barium both sterile and unsterile into the peritoneal cavity and barium perforation were fatal in 20--48 hours in the dog without further treatment. This study shows that the repair of a barium perforation should be considered as one of the most important emergency procedures. Operative methods and problems are described.


[Duckbill fractures of the tuber calcanei, etiology and treatment]. This report is of two cases of tuber calcanei fractures (fractures of group I according to Böhler). In one case the fracture occured after direct trauma, in the other after an uncorrdinated maximal contraction of the triceps muscle. The different origins of this type of fracture are discussed and the reported cases in the literature are reviewed. Both fractures were treated by osteosynthesis. Immediate operation is indicated because problems in the surrounding soft tissues are to be expected.


Intraspecific karyotypic differentiation in the Australian phasmatid Didymuria violescens (Leach). I. The chromosome races and their structural and evolutionary relationships. The phasmatid species Didymuria violescens comprises ten distinct chromosome races parapatrically distributed such that adjacent races meet in narrow zones of overlap. The interracial karyotypic variation is remarkable and involves both diploid number differences (in the range 26-40) and differences in the sex-chromosome mechanism. Karyotypic comparisons and analyses of the meiotic pairing relationships in interracial hybirds have shown that the differences derive in large part from a series of centric fusion events and X-autosome fusions, which together contribute to the reduction in chromosome number within the species. The origin and development of the current racial pattern can best be interpreted in terms of the stasipatric hypothesis of White.


The mitotic chromosomes of Notophthalmus (=Triturus) viridescens: localization of C banding regions and DNA sequences complementary to 18S, 28S and 5S ribosomal RNA. The metaphase chromosomes of Notophthalmus (Triturus) viridescens have been studied by C-banding and in situ hybridization. The chromosomes show the pericentric C-banding seen in many organisms and in addition have interstitial C-bands located a short distance from the pericentric C-bands on each chromosome arm. A few C-bands are seen in telomeric regions. Regions which hybridize in situ with 18S and 28S ribosomal RNA were found on three chromosome pairs. The animals studied fell into three groups with respect to which of the six possible sites showed detectable hybridization with 18S and 28S RNA. Individual animals differed not only in the pattern of in situ hybridization of ribosomal RNA but also in the number of ribosomal RNA cistrons in the genome as measured by saturation hybridization on purified DNA. In situ hybridization showed five pairs of chromosomes which contained DNA complementary to 5S RNA. The four pairs of subtelocentric chromosomes in the N. viridescens karyotype all have 5S DNA in the pericentric regions. The fifth cluster of 5S DNA is in the middle of one arm of the chromosomes in one of the two smallest submetacentric pairs in the genome. The five sites of 5S DNA differ markedly in the level of in situ hybridization with 5S cRNA.


Identification of the lampbrush chromosome loops which transcribe 5S ribosomal RNA in Notophthalmus (Triturus) viridescens. The loops which transcribe 5S ribosomal RNA in lampbrush chromosomes of the newt, Notophthalmus (Triturus) viridescens, were identified by hybridizing purified 5S DNA to nascent 5S RNA in situ. The genes which code for 5S RNA were found near the centromeres of chromosomes 1, 2, 6, and 7 by hybridizing iodinated 5S RNA to denatured lampbrush and mitotic chromosomes in situ. These genes and their intervening spacer DNA were isolated from Xenopus laevis using sequential silver-cesium sulfate equilibrium centrifugations. This purified 5S DNA was iodinated and hybridized to non-denatured lampbrush chromosomes in situ, where it bound to nascent 5S RNA on loops at the base of the centromeres of chromosomes 1, 2, 6, and 7. The number of 5S genes present in the haploid chromosome complement of N. viridescens was determined. - The 5S loops were chosen for study, since (1) the synthesis of 5S RNA has been demonstrated during the lampbrush stage, (2) both 5S RNA and 5S DNA could be isolated in pure form, and (3) the localization of the repetitive 5S genes could be verified by conventional in situ hybridization procedures. These methods may be applicable to the identification of other loops, leading to a better understanding of lampbrush chromosome function.