Evidence for a positional memory in the development of the chick wing bud. Grafts of quail zones of polarizing activity (ZPA), treated with 10000 rad gamma-radiation, tend to remain at the base of a limb. Their signalling ability is not passed on to more distal tissue, but the limb goes on to produce a reduplication. This suggests that the effect of a ZPA can be remembered in its absence, and explains why a normal limb can develop if its ZPA is removed.


Enzyme analysis of mouse extra-embryonic tissues. We have separated for enzyme analysis the following layers that surround the conceptus at midgestation: decidua, trophoblast, parietal endoderm (including Reichert's membrane), visceral endoderm, yolk-sac mesoderm and amnion. Measurement of several catabolic enzyme activities (N-acetyl-beta, D-hexosaminidase, beta-glucuronidase, alkaline and acid phosphatases and non-specific esterases) in these tissues indicates that they are biochemically distinct, perhaps reflecting the different functions that they perform in providing the embryo proper with a desirable environment for differentiation and development. Our studies also provide an example of how visceral endoderm cells can effectively block passage of maternal macromolecules (in this case a serum esterase) in the fetal circulation. Finally, since there is often difficulty in distinguishing among early embryonic and extra-embryonic cell types produced in teratocarcinoma cultures, we have considered how our observations might be of use in the respect, particularly in discriminating between visceral and parietal endoderm.


Foetal haemopoiesis during the hepatic period. II. Topographic histology. Serial sections of mouse foetal liver, during the 9th and 16th days of gestation, were studied. The erythropoietic process starts in the central area of the growing hepatic lobes, and subsequently spreads towards the periphery. Each lobe passes successfully through an undifferentiated, proliferating and differentiating period, but does not proliferate and differentiate in a homogeneously synchronized way, since the onset of both histogenesis and erythropoiesis is delayed at the periphery, when compared with the central area. As a consequence, in sections it is possible to find three different zones, namely: marginal, which is the most undifferentiated; intermediate (transitional); and a central area, which is the most mature, since it is the first site where erythropoiesis arises. These zones are distinguishable not only by their cell distribution, but also by the biological behaviour of their elements, specially in the transitional areas between undifferentiated and proliferating zones. The hepatic lobes do not start their organogenesis at the same time; but those of them in which histogenesis is delayed, repeat courses of development similar to those previously organized. The first interstitial erythropoiesis appears in the central area, after the development of an organized network of sinuses, and in close relation to vascular channels. Dynamic images of immature blood cells, between interstitial and vascular spaces, suggesting passage through the endothelium, are often seen. These steps are followed, in a concentric form and spreading towards the periphery, by each hepatic lobe.


Investigation of the fate of 4-5 day post-coitum mouse inner cell mass cells by blastocyst injection. Two distinct patterns of chimaerism were found in conceptuses produced by injecting dissociated 4.5-day inner cell mass cells into genetically dissimilar blastocysts. Pattern 1: donor cells were found in the endoderm layer of the visceral yolk sac, but not in the adjacent mesoderm layer of this organ or in the foetus itself. Pattern 2: donor cells were found in the mesoderm layer of the visceral yolk sac and/or foetus, but never in the yolk-sac endoderm as well. Primitive endoderm cells of donor inner cell masses are responsible for the first pattern and primitive ectoderm cells for the second. These results, together with those of previous studies, suggest that the entire foetus, including its endodermal components, is formed from the primitive ectoderm, and that primitive endoderm forms only extra-embryonic endoderm of the conceptus.


Investigation of the lethal yellow Ay/Ay embryo using mouse chimaeras. Chimaeric combinations of normal and mutant embryonic tissues were used to investigate the lethal effect of the yellow gene. The homozygous mutant embryos could not be identified before implantation. Therefore, embryos from both intercross matings and control backcross matings were used to provide inner cell masses (ICMs) for injection into genetically marked blastocysts of the CFLP random bred stock. All conceptuses obtained from reimplanted blastocysts were analysed at mid-gestation for the presence of donor isozyme of glucose phosphate isomerase. A similar proportion of chimaeras were found in the experimental and control series, indicating rescue of the lethal Ay/Ay ICM tissue. The reciprocal experiment also produced a similar proportion of chimaeras but there was a 25% postimplantational loss of injected embryos evidenced by empty decidual swellings. The results suggest that the yellow mutation primarily affects the trophectoderm which cannot be rescued by a normal ICM, whereas Ay/Ay ICM is capable of survival in a chimaera at least until mid-gestation.


An analysis of pigment cell development in the periodic albino mutant of Xenopus. The periodic al,bino mutant (apap) of Xenopus in which the development of melanophores is impaired, is further reported here to possess an aberrant pattern of iridophore differentiation. The development of mutant and wild-type neural crest explants isolated in vesicles derived from tissues from identical and different genotypes was examined to determine if the mutant effect resides in the pigment cells or is mediated by the environmental tissues. Mutant melanophores and iridophores cultured in either mutant or wild-type tissues exhibited mutant patterns of differentiation. Wild-type pigment cells cultured in both wild-type and mutant tissues exhibited wild-type patterns of differentiation. Hence the mutation affects the capacities of melanoblasts and iridoblasts to differentiate but not the ability of the environmental tissues to support pigment cell differentiation.


Regulation and limb regeneration: the effect of partial irradiation. The regulative ability of the regeneration blastema has been studied by the technique of partial irradiation. Longitudinal halves of fore- and hindlimbs were irradiated and the product of regeneration from the unirradiated halves characterized. Such half irradiated limbs could regulate only to a very limited extent. In the upper arms the anterior halves merely produced a few autopodial elements whereas complete limbs regenerated from the posterior halves. This striking regenerative inequality was less marked in the lower arm where the two halves each produced regenerates of two to three digits. In the hindlimb dorsal halves produced more than ventral halves and thus it was concluded that the posterior-dorsal quadrant has some special regenerative property. These results highlight the inadequacy of current models of limb regeneration and are discussed with reference to the arrangement of positional values in the limb and the question of the totipotency of blastemal cells.


Time-dependent effects of alpha-amanitin on blastocyst formation in the mouse. Early compacting mouse morulae were placed in alpha-amanitin at various times after HCG and the effect of this transcriptional inhibitor during formation of the blastocyst was noted. No cavitation was observed in those embryos transferred into alpha-amanitin before 77 h after HCG but the percentage of cavitation increased dramatically in those embryos transferred after 80 h post HCG. The large increase in amino acid incorporation which normally occurs during fomration of the blastocyst was blocked in those embryos placed in the inhibitor before 80 h post HCG. Two-dimensional polyacrylamide gel electrophoresis of radiolabelled embryos showed that the changes in synthesis of certain polypeptides normally associated with blastocyst formation did not occur in those embryos placed in alpha-amanitin before 80 h after HCG. Only one cleavage division appears to occur in the presence of alpha-amanitin. However, groups of embryos which had completed their fifth division before exposure to the drug subsequently were able to form blastocysts and showed the quantitative and qualitative changes associated with blastocyst formation despite the continued presence of the inhibitor. These results suggest that a critical transcriptional event concerned with blastocyst formation occurs around 80 h after HCG and may be associated with the fifth cleavage division.


Lethality of radioisotopes in early mouse embryos. The development of pre-implantation mouse embryos was found to be prevented by exposure of the embryos to [35S]methionine, but not to [3H]methionine. Such embryos have also been shown to be highly sensitive to [3H]thymidine. These observations are discussed with reference to the path lengths and energies of electrons emitted from the different radioisotopes.


Cytoplasmic and nuclear protein synthesis in preimplantation mouse embryos. Cytoplasmic and nuclear proteins synthesized by mouse embryos at different stages of preimplantation development were analyzed by two-dimensional polyacrylamide gel electrophoresis. Several nuclear-specific proteins (i.e. proteins more abundant in the nucleus than in the cytoplasm) and numerous cytoplasmic-specific proteins were observed. The trends of changes in the nuclear and cytoplasmic protein synthesis are similar. Moderate changes occur between the unfertilized egg and the zygote. Striking changes characterized by the disappearance of numerous major oocyte-specific proteins and the appearance of a large number of new, stage-specific proteins occur between the zygote and the 4- to 8-cell stages. In contrast, between the 4- and 8-cell and early blastocyst periods, only a few new proteins appear, and a small number of oocyte-specific or other stage-specific proteins disappear. Minor differences in protein synthesis were observed between the trophoblast and inner cell mass.


The development of hepatogenic potency in the endoderm of quail embryos. Hepatogenic potency of the endoderm is detectable in the anterior half of the endoderm of quail embryos older than 2-somite stage when endodermal fragments are cultured with or without heterologous chick mesenchymes, in the coelomic cavity of 3-day chick embryos. On the other hand, the posterior half of the endoderm never has hepatogenic potency. The hepatogenic potency of the endoderm is gradually stabilised with increasing age. However, expression of hepatogenesis can be affected when the endoderm is associated with inductively active digestive tract mesenchymes. Mesenchyme taken from the presumptive cardiac region ('cardiac' mesenchyme) of chick embryos is necessary for the uncommitted anterior endoderm to acquire hepatogenic potency, and this effect is specific for the 'cardiac' mesenchyme. The 'cardiac' mesenchyme, however, fails to induce hepatic epithelium in the allantoic endoderm, which can differentiate heterotypically when cultured in combination with digestive tract mesenchymes. The evidence presented in this study suggests that the effect of 'cardiac' mesenchyme on the acquisition of hepatogenic potency in the endoderm is limited.


The morphology of fetal gonads of spontaneous mouse hermaphrodites. The gonads of 107 spontaneous, chromosomal mosaic, day-15 fetal hermaphrodites derived from BALB/cWt strain male mice are described and photographs of seven gonads representative of the major types are presented. There were 16 ovaries, 15 testes, and 183 ovotestes. The ovotestes contained on the average more testicular tissue than ovarian, and the ovarian tissue was more frequently located at the gonad poles, particularly the craniad pole. There was no difference between left and right sides with regard to gonad type, but more pure gonads were found on the left than on the right side (21/10), Meioses were observed throughout the ovarian tissue and also in some testicular cords, particularly in the caudad pole of the gonad. Some meiotic figures contained sex vesicles. The significance of these findings is discussed in relation to several aspects of sex determination.


Marginal zone cells--the primitive streak-inducing component of the primary hypoblast in the chick. (1) Removal of both the area opaca and the marginal zone of the area pellucida from a blastoderm stripped of its hypoblast (type-IV operation) prevents the regeneration of a normally functioning primary hypoblast. (2) Stage-XIII E.G. & K blastoderms (prior to the appearance of PS) after a type-IV operation do not form a primitive streak. (3) In order type-IV operated blastoderms in which the primitive streak has already begun to appear, the regeneration of a non-functional hypoblast did not support the normal maturation of the primitive streak, and in many cases the already existing rudimentary streak was absorbed. (4) Type-IV operated blastoderms from stage 3+ H + H and on developed normally. (5) It is concluded that the cellular contribution of the marginal zone to the primary hypoblast is instrumental in the latter's capacity to induce a PS.


Interactions between optic fibres controlling the locations of their terminals in the goldfish optic tectum. Removal of the caudal half of a goldfish optic tectum induces optic fibres from the entire contralateral retina to terminate retinotopically within the remaining half. This compression has been viewed by some as the result of competition between the fibres and by others as a consequence of changes, induced by the surgery, in tectal labels guiding fibres to terminal sites. To distinguish between these possibilities, the time-course of compression has been measured by electrophysiological mapping of the visual projection. In some fish, fibres terminating in the rostral half-tectum remained intact when the caudal half was removed. In others, the optic nerve was cut at the time of tectal surgery: even after its regeneration into a half-tectum, optic terminals were first detected in the regions they normally occupy. The subsequent reorganization was gradual and retinotopic order was maintained. However, it was slower where some fibres had never been cut. In a third series the nerve was cut 18 days before the tectal halving to reveal any dependence of compression on progressive changes in the halved tectum; but its time-course from nerve section was found to be independent of the time within the regeneration period at which the tectum was halved. In a fourth series the nerve was cut at the time of tectal halving and then cut again after 85--97 days when compression was complete to reveal any permanent change in the halved tectum. No change was evident: the previous compression did not preclude subsequent regeneration of an uncompressed projection and its gradual recompression as before. In a fifth series, repeated crushing of fibres normally ending in the missing caudal tectum temporarily prevented compression among the remainder, while crushing of fibres destined for rostral tectum caused transposition of the remaining projection to the rostral half. Surgically induced changes in the labels which are thought to guide growing fibres to their normal tectal regions do not account for these results. Indeed, this guidance persists unchanged for fibres regenerating a second time after compression. Since compression is delayed while certain fibres are withheld, it appears instead to be the direct result of competition between the fibres. The maintenance of retinotopic order in compression, despite unchanged tectal guidance, may require selective interactions between fibres from different retinal regions which could contribute to the refinement of the normal visual projection.


Depth and elaboration of processing in relation to age. Processing at encoding and retrieval was jointly manipulated, and then the retrieval effectiveness of different cues was directly compared to uncover the relative pattern of deep and elaborate processing in relation to both age and different experimental manipulations. In experiment 1 phonemic and semantic cues were effective retrieval aids for to-be-remembered words in the youngest group; with increasing age, semantic cues decreased in effectiveness more than phonemic cues. These data showed phonemic features to have an importance that is not recognized in the data generated by the typical levels paradigm. When elaboration of the words was induced in Experiment 2 by presenting them in sentences, semantic and context cues were most effective in the youngest group whereas phonemic cues were most effective in the oldest group. Since the pattern of cue effectiveness in the elderly was similar to that in Experiment 1, where the same words were presented alone, it was concluded that aging results in poor elaboration, in particular, in inefficient integration of word events with the context of presentation. These age effects were mimicked in young subjects in Experiment 3 by experimentally restricting encoding time. The present approach uses somewhat modified views of depth and elaboration.


Response versus place learning by human infants. Two cross-setional studies examined how infants learn the location of visual events. In Experiment 1, infants of 4, 8, and 12 mo of age learned to turn one way to view a novel pattern. In a subsequent transfer task, they were rotated to face the opposite side of the room. The 4-mo-old infants tended to err by repeating their previously learned response, but within 16-20 trials their performance was comparable to the higher levels maintained by the older infants. These results suggest that young infants learn the location of the pattern primarily in terms of response cues, whereas older infants employ both response cues and place cues. Experiment 2 was designed to independently assess the use of response cues and place cues by infants of 4, 8, 12, and 16 mo of age. All infants were able to rapidly learn and remember the location of the novel pattern when they were given response cues. There was a gradual emergence of place-cue use associated with age. It is suggested that the decrease in infant egocentricity in such spatial localization tasks may in fact reflect an age-related increase in the variety of reliable cues responded to by infants.


A perspective on the brittle teenage diabetic. The brittle teenage diabetic presents a difficult problem well known to clinicians. It is the authors' contention that its major component is psychological and not biological, and that much of this poor control can be avoided by proper developmental planning from the onset of disease. Failure to modify transactional health care models appropriate for the child to that appropriate for the adolescent accounts for much of this difficulty. Anticipatory long-range planning is outlined to aid the physician in allowing the youth to isolate and insulate his diabetes from becoming either a focus for control contests and power struggles or a maladaptive, manipulative regressive behavior. The reasonable goal is to prevent any further hospitalizations for ketoacidosis or hypoglycemia beyond the first admission for diagnosis and initial stabilization. Five illustrative cases augment this discussion.


Depression in family practice: changes in pattern of patient visits and complaints during subsequent developing depressions. This study was done to characterize changes in patient behavior during specific time periods immediately before first, second, third, and fourth episodes of depression. Forty-three patients from a group of 154 depressed patients examined in an earlier study developed 59 subsequent episodes of depression, and these were the patients used in this study. Suitable age and sex matched controls were also examined for the same time periods. The depressed patients and controls were patients in a rural solo practice. The depressed patients showed increased number of patient initiated visits, increased incidence of hospitalization, increased number of functional complaints, increased number of pain complaints, and increased feelings of tension as compared to controls during the seven months prior to the diagnosis date of the first and each succeeding episode of depression. The study results indicate that increased numbers of office visits, functional complaints, pain complaints, and anxiety complaints can be harbingers of a clinical depression, whether it be the index (first) or a subsequent depressive illness.


Groups for bereaved parents-how they can help. The authors wished to establish an organized approach for helping parents of patients who had died. Over a 14-month period, 81 people participated in a series of groups. A closed-group, eight-meeting format was used, under professional leadership. Main topics covered in discussion were: problems and feelings associated with the death of the child; problems of coping with everyday life; and philosophical issues. Conclusions emphasize the need for professional leadership and screening of potential members. The groups were found to be an effective way to help normal people with normal grief. Participants saw their experience as extremely valuable, and as something which could not be gained through conventional therapy.


Attitudes of women toward the gynecologic examination. This study was undertaken to determine why patients feel uncomfortable during the gynecologic examination, to assess general knowledge about the procedures, and to find out what would make the patient feel better about the examination. Nine hundred seventy-seven women sampled in 14 different health care facilities in the Salt Lake area in Utah filled out a two-page, self-administered questionnaire while waiting for a medical appointment. Results show that women feel less comfortable during the pelvic examination than they do during the breast examination; physical discomfort of the pelvic examination is the reason most frequently cited. There were 77.1 percent who stated they would feel better about the examination if the physician told them what was going to happen. Over 70 percent wanted to know more about their female organs, normal sexual functions and emotions, and reasons and procedures for the pelvic examination; 68.3 percent felt that knowing more would make them more comfortable. There were 46.5 percent who thought the use of a mirror for the woman to observe the examination was a good idea. Only 28.9 percent knew the rectum was examined. This study shows that women need and want to be educated about the gynecologic examination.


An evaluation system for an undergraduate clerkship in family medicine. In 1970, all final year medical students at the University of Ottawa were required to complete a four-week clerkship in family medicine. The original evaluation system being used consisted of an ongoing assessment by the students' preceptor and a terminal test. This method was unsatisfactory, resulting in four new criteria for the terminal test being established: (1) that it be objective, reproducible, and reliable; (2) that it assess attitudes toward the patient; (3) that it be flexible and not rigidly structured; and (4) that it simulate actual family practice as closely as possible. A new preceptor's evaluation form was also developed. With annual assessment of the evaluation method since 1973, numberous modifications have been introduced to meet the criteria originally sought. Use of a mark sense data entry system and packaged analysis programs have facilitated ongoing evaluation of the system. Currently the preceptor's evaluation form meets both educational and assessment requirements, and the terminal tests meet the criteria developed in 1971.


The costs of a family practice residency ambulatory care program. The cost of patient care service and education occurring in a family practice residency unit of a community based prepaid health program was determined from accounting records. The cost of producing the same number of patient visits in comparable family practice units which did not have residents on-site was determined in a similar manner. The cost per visit in the residency unit was $15.53 while that in the nonresidency unit was $13.92. There was an excess cost of $1.61 per visit in the residency, or, based on the number of residents present, a net cost of $7 per resident per day. None of the costs of central residency program administration or of ambulatory based subspecialty rotations were included. While a small increase (ten percent) in productivity or efficiency would result in the residency patient care unit itself being self-sustaining, this study casts considerable doubt on the ability of the model family practice residency unit to offset the full costs of the ambulatory care portion of family practice residency training.


Resource requirements for teaching continuity in primary care: contrasts between a graduate and an undergraduate program. Two similar primary care training programs for family practice residents and for medical students are compared to find differences and similarities in costs and the use of certain nonmonetary resources. Both programs emphasize long-term continuity, and trainees in both programs average two half-days per week at ambulatory care practice sites. Comparisons of the resource requirements of teaching high-continuity primary care curriculum segments between graduate and undergraduate programs will help determine where scarce medical teaching resources can be most beneficially used. It is hypothesized that there would be lower faculty costs, higher auxiliary staff and space requirements, and larger patient panel requirements for the residency program than for the undergraduate program. Extent of these differences could not be predicted. In the residency program, faculty costs were one quarter of total expenses and in the undergraduate program they were half of the program expenses. The residency recouped 81 percent of expenses from practice revenues while the undergraduate program recouped only 59 percent. The residency program averaged 814 visits per trainee during one year; the undergraduate program had only 268 visits per student.


Differences in morbidity patterns among rural, urban, and teaching family practices: a one-year study of twelve Colorado family practices. An analysis of one year's data from family practices in Colorado tested the hypothesis that there are no significant differences in the proportion of patients with problems in each of the 18 major International Classification of Health Problems in Primary Care (ICHPPC) categories among visiting patients in rural, urban, and teaching family practices. Four rural, three urban, and five residency practices participated in the study from January 1, 1978, through December 31, 1978. Transient patients were excluded. There were 25,525 patients included in the study. Each setting was compared with the other two settings in each of the 18 ICHPPC categories. More than half of the comparisons differed at the .001 significance level, and the setting with a significantly greater proportion of visiting patients with diseases in a given category was identified. These differences may have implications for disease surveillance, the planning for delivery of primary health care in different settings, and the preparation of health care providers for practice.


Parotid gland swelling.

Parotid gland swelling. The salivary glands are seldom noticed by the physician when they are functioning properly, but they cause vexing problems in diagnosis and management during times of their disordered function. One reason for this is that numerous salivary diseases have similar onsets and patterns of symptomatology. Another reason is that the clinical expression of these diseases is often similar, including pain, diffuse swelling, and altered salivary discharge. This paper enumerates useful points of differentiation which may be elicited from the history and physical examination to distinguish among parotid diseases. If management is to be successful, it must be based on (1) identification of the etiology of the pathologic process, and (2) the institution of therapeutic measures designed to eliminate the etiology of the disease, and restore, as closely as possible, the normal physiology of the gland.


Regulation of glucosyl- and fructosyltransferase synthesis by continuous cultures of Streptococcus mutans. Streptococcus mutans strains Ingbritt, and its derivative B7 which had been passaged through monkeys, have been used to investigate how the synthesis of extracellular glucosyl- and fructosyltransferases is regulated. The most active enzyme from carbon-limited continuous cultures was a fructosyltransferase; enzymes catalysing the formation of water-insoluble glucans from sucrose were relatively inactive. Dextransucrase (EC 2.4.1.5), which catalyses soluble glucan synthesis, was most active in the supernatant fluid from cultures grown with excess glucose, fructose or sucrose, but full activity was detected only when the enzyme was incubated with both sucrose and dextran. Little dextransucrase activity was detected in carbon-limited cultures. It is concluded that glucosyl- and fructosyltransferases are constitutive enzymes in that they are synthesized at similar rates during growth with an excess of the substrate or of the products of the reactions which they catalyse. Although the Ingbritt strain was originally isolated from a carious lesion, it is now a poor source of glucosyltransferase activity. Glucosyltransferases were extremely active in cultures of a recent clinical isolate, strain 3209, and were apparently induced during growth with excess glucose.


A taxonomic study of clinical isolates of Pseudomonas pickettii, 'P. thomasii' and 'group IVd' bacteria. On the basis of cluster analysis, average similarities within and between groups, and DNA base composition of selected strains, Pseudomonas pickettii appeared to be a distinct species comprising several biotypes. Although some or all of these biotypes, represented by subclusters in our computer study, may ultimately warrant recognition as separate species, our results were not conclusive enough to warrant such a proposal at present. Most strains tentatively named 'P. thomasii' could be included in P. pickettii so that the name P. pickettii, which was validly published whilst 'P. thomasii' was not, takes priority over 'P. thomasii'. Strains of Group Va (Tatum et al., 1974) examined were also included in P. pickettii. Group IVd (King, 1964) did not appear to be a natural group but some of the strains could also be included in P. pickettii.


Genetics of actinorhodin biosynthesis by Streptomyces coelicolor A3(2). A series of 76 mutants of Streptomyces coelicolor A3(2) specifically blocked in the synthesis of the binaphthoquinone antibiotic actinorhodin were classified into seven phenotypic classes on the basis of antibiotic activity, accumulation of pigmented precursors or shunt products of actinorhodin biosynthesis, and cosynthesis of actinorhodin in pairwise combinations of mutants. The polarity of cosynthetic reactions, and other phenotypic properties, allowed six of the mutant classes to be arranged in the most probable linear sequence of biosynthetic blocks. One member of each mutant class was mapped unambigiguously to the chromosomal linkage map in the short segment between the hisD and guaA loci, suggesting that structural genes for actinorhodin biosynthesis may form an uninterrupted cluster of chromosomal genes.


Differential neutralization of spontaneous and centrifuge-assisted chlamydial infectivity. Neutralization by specific antibody of a fast-killing variant strain of Chlamydia trachomatis, which showed high spontaneous infectivity for cell monolayers, was examined. It appeared that in spontaneous infection antibody-treated chlamydiae were neutralized by inhibition of attachment to cells. Centrifugation imposed a different effect: infection was inhibited at some step at or subsequent to attachment.


Multi-factorial specification of virus-host interactions: studies with strains of Venezuelan equine encephalomyelitis virus in mice. Mice of different ages were infected i.p. or i.c. by 23 different strains of VEE virus. The course of the virus host interaction was specified in terms of the efficiency of infection, the outcome of infection as lethality or protection and the survival time. These separately quantifiable features all showed several host-maturation events that combine to provide a multifactorial specification of virus-strains and host-responses. This base-line for correlations with the responses of principal hosts (equidae and man) may be expanded to test correlations with the antigenic or in vitro characteristics of virus-strains.


Fer de Lance virus (FDLV): a probable paramyxovirus isolated from a reptile. A new virus has been isolated by inoculation of lung tissues of diseased snakes into snake embryos. Homogenates of infected embryo tissues caused c.p.e. in cell cultures incubated at 30 degrees C. The virus replicates in a wide variety of reptilian or mammalian cell types incubated at 30 degrees C, inducing either syncytium formation or minimal or no cytopathic changes. Efficient replication occurs in embryonated hens' eggs at 27 to 30 degrees C. The virus haemagglutinates guinea pig and chick erythrocytes; it possesses a neuraminidase similar to the receptor-destroying enzyme of Vibrio cholera. Electron microscopic observations of infected cells examined in thin section revealed pleomorphic viruses 146 to 321 nm in diam. resembling known myxoviruses. Internal nucleocapsid strands are 15 to 16 nm in diam.; nucleocapsid observed in negatively stained preparations measures 14 nm in diam. The virus was determined to possess a nucleoprotein core containing a 50S single-stranded unsegmented RNA genome. All characters of the virus are similar to those of the paramyxovirus group except that the nucleocapsid diam. is intermediate between that of paramyxoviruses and pneumoviruses. The virus is antigenically distinct from known myxoviruses and is unique among myxoviruses in its restriction to growth at temperature below 37 degrees C.


Comparative studies of wild-type and cold-mutant (temperature-sensitive) influenza viruses: independent segregation of temperature-sensitivity of virus replication from temperature-sensitivity of virion transcriptase activity during recombination of mutant A/Ann Arbor/6/60 with wild-type H3N2 strains. RNA 1 (see end of Summary) of a cold-adapted and temperature-sensitive (ts) influenza virus mutant A/Ann Arbor/6/60 has a different mobility from RNA 1 of wild-type (wt) A/Ann Arbor/6/60 when subjected to electrophoresis through acrylamide/agarose gels in the absence of denaturing agents. Detection of this lesion in RNA 1 of the mutant virus was dependent on the temperature of the gel during electrophoresis. Because RNA 1 is believed to code for a protein involved in virus-specific RNA synthesis we compared phenotypes of virion transcriptases in the wt and mutant viruses. The enzyme of the mutant virus was found to be about 40% less active at 40 degrees C than the enzyme of the wt virus when related to their activities at 31 degrees C. Two cold-adapted ts recombinants which derive their RNA 1 from the mutant A/Ann Arbor/6/60 have virion transcriptases with a phenotype similar to that of their mutant parent. Three different cold-adapted ts recombinants, however, which also derive their RNA 1 from the mutant A/Ann Arbor/6/60, have virion transcriptases with a phenotype similar to that of wt virus. We conclude, therefore, that the conditional-lethal ts property of A/Ann Arbor/6/60 mutant and its recombinants is independent of the phenotypic marker observed for the A/Ann Arbor/6/60 mutant virion transcriptase, and that the lesion in RNA 1 of the mutant may also be unrelated to the observed difference between virion transcriptases of the mutant and wt A/Ann Arbor/6/60 viruses. The phenotypes of the virion transcriptases in recombinants did, however, correlate with the derivation of their RNA 2. This suggests that the increased temperature-sensitivity of virion transcriptase of the A/Ann Arbor/6/60 mutant is caused by either (1) a lesion (not necessarily conditionally lethal) that occurred in its RNA 2 during the course of cold-adaptation, or (2) a lesion in another gene whose product is a component of the virion transcriptase complex, but which lesion is only expressed phenotypically when there is a synergistic interaction in the transcriptase complex with the product of A/Ann Arbor/6/60 rna 2.


Correlation of pathogenicity and gene constellation of influenza A viruses. III. Non-pathogenic recombinants derived from highly pathogenic parent strains. We have demonstrated by recombination of two highly pathogenic avian influenza viruses [A/FPV/Rostock (Hav1N1) x A/turkey/England/63 (Hav1Nav3)] that recombinants can be isolated which are pathogenic as well as non-pathogenic for chickens. They carried the glycoproteins of either parent strains, and all are produced in infectious form in chick embryo cells. Genetic analysis revealed that the non-pathogenic recombinants possess a mixed RNA polymerase complex, consisting of pol 1, pol 2, ptra and NP gene products, while, with one exception, the pathogenic recombinants have the genes coding for the polymerase activity from one or other parent virus. The biological properties of the recombinant viruses did not correlate with their pathogenicity for chickens.


The localization of influenza virus in the respiratory tract of ferrets: susceptible nasal mucosa cells produce and release more virus than susceptible lung cells. Infectious virus production by ferret nasal mucosa and lung organ cultures has been monitored in both tissue pieces and medium over 24 h following inoculation with an Asian (H2N2) strain of influenza virus. Freshly prepared cultures of nasal mucosa produced approx. 10-fold more virus per cell than fresh lung cultures. Also the nasal mucosa cells liberated into the medium a greater proportion (mean 31%) of the total virus produced than did fresh lung (mean 6%). Maintenance of lung explants for 24 h prior to inoculation resulted in a 20- to 100-fold increase in the amount of virus released. However, total virus production by fresh and maintained lung was similar. Trypsin did not increase the infectivity of virus released from any of the cultures, indicating that the haemagglutinin in the virus particles was cleaved. Similar results were obtained with a Hong Kong (H3N2) virus strain. Hence, one factor operating in the lower susceptibility of the lung compared with the nasal mucosa in vivo may be a lower capacity of lung cells both to produce and release influenza virus.


A marsupial oncovirus?

A marsupial oncovirus? A virus-like particle was observed in two continuous cell lines derived from the marsupial Sminthopsis crassicaudata (Fat-tailed Dunnart). The development of the particle was similar to the development of D-type oncoviruses. Initially, a crescentof nucleoid material was observed near the nucleus in the region of the Golgi apparatus. This crescent developed into a doughnut-shaped-A-type particle which migrated through the cytoplasm towards the cell membrane where it budded either into a smooth membrane cytoplasmic vacuole or from the cell membrane. Only enveloped A-type particles were observed; no mature B-type, C-type or D-type particles were detected.


Non-specific adsorption of interferon to immobilized serum immunoglobulin. Human leukocyte interferon attaches to hyperimmune serum immunoglobulins, coupled to agarose, even though the antibodies are not specific for interferon. Unless it is first washed off with ethylene glycol, the attached interferon elutes together with immune-specific antigens during immuno-affinity chromatography.


Two modes of entry of reovirus particles into L cells. Evidence is presented supporting the hypothesis that reovirus intermediate subviral particles (ISVP), which show increased infectivity relative to intact virions, can gain entry into host L cells by two alternative pathways. One pathway is by the process of viropexis, involving phagocytic vacuoles. A second entry pathway is via direct penetration of the plasma membrane of the cell, without involvement of a phagocytic vacuole. Using electron microscopy, a kinetic analysis of the uptake process was carried out. Results indicate that at 37 degrees C ISVP gain entry into host cells primarily by direct entry, although viropexis also occurs, while intact virions gain entry by viropexis almost exclusively. A second line of experimental evidence consistent with the idea that ISVP can 'melt' their way through the plasma membrane is provided by studies on the release of pre-loaded radioactive 51Cr from host cells following infection. 51Cr release data demonstrate that infection with ISVP leads to an immediate increased leakiness of the cell plasma membrane, whereas no such increase takes place following infection with an equivalent number of intact virions. This demonstrates that ISVP can interact with the plasma membrane of the cell in a manner which is qualitatively different from the interaction between intact virions and the plasma membrane. The ability of ISVP to directly penetrate the plasma membrane of the host cell, which intact virions apparently cannot do, could explain the decreased duration of the eclipse phase, as well as the increased infectivity of ISVP, relative to that observed for infection with intact virions.


Establishment of persistent infection in BHK-21 cells by temperature-sensitive mutants of Sindbis virus. Twelve temperature-sensitive (ts) mutants of Sindbis were examined for their ability to establish persistent infection in BHK-21 cells at 39 degrees C. Five of these mutants were able to initiate colony formation in infected cultures, which followed an extensive c.p.e. Two of the mutants were able to establish persistent infections which survived beyond the fifth cell passage p.i. The ability to initiate colony formation was correlated with low reversion of the ts mutation, or with ability to interfer with the multiplication of the wild-type virus. Virus released from persistently infected cultures was not temperature-sensitive. The restriction of virus multiplication in persistently infected cells operated prior to virus-specified RNA synthesis. It is concluded that in this system establishment of persistent infection depends on an inhibition of virus multiplication early in infection and occurs in only a small proportion of infected cells.


Differentiation of the haemagglutinin genes of variant influenza viruses by RNA-RNA hybridization. The genetic compositions of four antigenic variants of A/Memphis/1/71 (H3N2) influenza virus, which were selected by growth in the presence of monoclonal antibodies against the haemagglutinin, were compared. The results indicate that the mutant haemagglutinin genes can be differentiated by polyacrylamide gel electrophoresis of the double stranded RNA hybrids formed between virion RNA and transcripts isolated from infected cells.


Restriction endonuclease analysis of red cowpox virus and its white pock variant. The DNA of red cowpox virus strain Brighton or its white pock variant was analysed by cleavage with restriction endonucleases HindIII, XhoI, PstI or KpnI. Physical maps were constructed and the genomes compared with that of vaccinia virus strain DIE. The size of the red cowpox genome is 23 to 29 megadaltons greater than that of vaccinia and results from the presence of additional, near terminal sequences. An internal region of about 75 megadaltons appears to be highly conserved between the two viruses. The red cowpox genome contains near terminal, repetitive sequences which have some homology with those of vaccinia virus DNA. Rapid renaturation of red cowpox terminal restriction fragments indicates that these are covalently cross-linked. Viable white pock variants arise continually and map as deletion mutants lacking similar sequences from one specific terminus only of the parental genome. The deletion represents 11 to 12% of the red cowpox DNA and includes the terminal repetition which therefore is not required for replication. The deleted terminus of the white pock variant genome does not appear to be cross-linked.


Use of the 51chromium release test to demonstrate antigenic differences between extracellular and intracellular forms of vaccinia virus. Complement-dependent antibody lysis of vaccinia-infected cells was examined to demonstrate the antigenic differences between extracellular (ECV) and intracellular (ICV) forms of vaccinia virus. Cytolytic antibodies present in the antisera raised against ECV or live virus (LV) were completely removed by absorption with infected cell membranes or purified ECV but not with purified ICV. Absorption with infected cell membranes also abolished the neutralizing activity of ECV and LV antisera against ECV. On the other hand, antiserum against ICV did not contain cytolytic antibodies against vaccinia-infected cells, even though its neutralizing antibody titre against ICV was high. Moreover, both ECV and ICV antisera neutralized a small proportion of the heterologous form of virus, despite using purified preparations of ECV and ICV, respectively, for raising these antisera in rabbits. In contrast, the 51Cr release test only detected the antibodies against ECV and thus can be used to differentiate between the antibody activity of a serum against ECV and ICV.


Qualitative analysis of proteins rapidly transported in ventral horn motoneurons and bidirectionally from dorsal root ganglia. Two-dimensional electrophoresis has allowed a higher-resolution comparison of rapid transport in ventral horn motoneurons and bidirectionally in dorsal root sensory neurons. Dorsal root ganglia 8 and 9, or hemisected spinal cords, from frog were selectively exposed in vitro to 35S-methionine. Transported, labelled proteins that accumulated in 3 mm segments proximal to ligatures on dorsal roots and spinal nerves or sciatic nerves were subjected to two-dimensional gel electrophoresis. Comparisons were made of fluorographic patterns from dried gels. Sixty-five species of proteins were found to be rapidly transported in both bifurcations of dorsal root sensory neurons. No abundant species of protein was rapidly transported in dorsal roots that was not also found in spinal nerves. A comparison of proteins rapidly transported in the sciatic nerve from ventral horn motoneurons with those from dorsal root sensory neurons yielded 50 common species of polypeptides. At most four minor species were possibly transported only in ventral horn motoneurons. An overall comparison indicates that at least 45 species of proteins, including all of the more abundantly transported ones, were consistently common to both dorsal root bifuractions and to ventral horn motoneurons. This appears to be the case despite the very different functions carried out by motoneurons and sensory neurons.


The structure and function of serially homologous leg motor neurons in the locust. I. Anatomy. Twenty-one prothoracic and 17 mesothoracic motor neurons innervating leg muscles have been identified physiologically and subsequently injected with dye from a microelectrode. A tract containing the primary neurites of motor neurons innervating the retractor unquis, levator and depressor tarsus, flexor tibiae, and reductor femora is described. All motor neurons studied have regions in which their dendritic branches overlap with those of other leg motor neurons. Identified, serially homologous motor neurons in the three thoracic ganglia were found to have: (1) cell bodies at similar locations and morphologically similar primary neurites (e.g., flexor tibiae motor neurons), (2) cell bodies at different locations in each ganglion and morphologically different primary neurites in each ganglion (e.g., fast retractor unguis motor neurons), or (3) cell bodies at similar locations and morphologically similar primary neurites but with a functional switch in one ganglion relative to the function of the neurons in the other two ganglia. As an example of the latter, the morphology of the metathoracic slow extensor tibiae (SETi) motor neurons was similar to that of pro- and mesothoracic fast extensor tibiae (FETi) motor neurons. Similarly the metathoracic FETi bears a striking resemblance to the pro- and the mesothoracic SETi. It is proposed that in the metathoracic ganglion the two extensor tibiae motor neurons have switched functions while retaining similar morphologies relative to the structure and function of their pro- and mesothoracic serial homologues.


Some observations on habituation of the flexor reflex in the rat: the influence of strychnine, bicuculline, spinal transection, and decerebration. The involvement of inhibition in habituation of the flexor reflex was investigated in intact, spinal, and decerebrate rats. Strychnine and bicuculline were administered in order to determine the contribution of certain forms of central inhibition to the development of habituation. Both strychnine and bicuculline reduced habituation in the intact rat but did not do so in the spinal preparation. Strychnine, in fact, caused a facilitation of habituation in the spinal rat. The impairment of habituation by strychnine was related to the intensity of stimulation used to elicit the reflex. Thus, the effect of strychnine was only demonstrable when relatively high intensities were used. Flexor reflex habituation was shown to be more pronounced in the decerebrate than in the spinal preparation. This difference could be demonstrated only when stimuli of high intensity were given. It is concluded that, in the absence of supraspinal influences, habituation of the flexor reflex does not require inhibitory mechanisms. However, inhibition may play a role in habituation of the component of the reflex that utilizes descending influences.


Inhibition of spinal interneuronal activity by repeated cutaneous stimulation: a possible substrate of flexor reflex habituation. The responses of interneurones, situated in the lumbar region of the rat spinal cord, to repeated cutaneous stimulation, were studied. The main purpose of this investigation was to attempt to determine the extent to which habituation of the flexor reflex might be explained on the basis of a progressive development of inhibition. Spontaneously active interneurones, which were inhibited by cutaneous stimuli, were investigated in detail. In rats whose spinal cords were intact, the period of inhibition was shown to increase with successive stimuli. This increase in inhibition was directly related to the intensity and frequency of stimulation, occurred more rapidly during a second series of stimuli and was antagonized by strychnine. In spinal animals, an increase in the duration of the period of inhibition to repeated stimulation could not be demonstrated. In this preparation, a gradual decrease in inhibition occurred. It is tentatively concluded that inhibition of spinal interneurones, the development of which depends upon descending influences from supraspinal centres, may be partially responsible for habituation.


Plasticity of feeding behavior in the opisthobranch mollusc Navanax. Several forms of plasticity of feeding behavior were investigated in Navanax. Navanax is a gastropod mollusc which lacks a radula, and ingests prey with suction caused by rapid pharyngeal expansion. Feeding is little affected by handling or posture and is resistant to the noxious stimulus of cutting through the body wall. Feeding is affected by arousal, as shown by a decrease in latency following initial exposure to food. The feeding response also habituates, as shown by an increase in latency when feeding responses are elicited without allowing animals to engulf food. The latency increase is not likely to be due to motor fatigue, since it can be partially reversed by dishabituation with an alternate prey species. Continued feeding causes satiation, as shown by increased feeding latencies and eventual cessation of feeding after a mean weight gain of 42.0% of initial animal weight (N = 12). Another form of plasticity occurs when Navanax are presented with food too large to swallow whole. Navanax either cease to respond after a few presentations, perhaps due to habituation, or maintain suction on the partially swallowed prey for an extended period of time. During extended sucks, the more deeply ingested portions are digested.


The morphology and coupling of Aplysia bag cells within the abdominal ganglion and in cell culture. The bag cells in the abdominal ganglion of Aplysia californica control egg-laying behavior by releasing a polypeptide (ELH) during an afterdischarge of synchronous action potentials. We have used intracellular injection of Lucifer Yellow to study the morphology and interconnections of the bag cells. These neurosecretory cells are typically multipolar and their processes extend in all directions out from the bag cell clusters into the surrounding connective tissue, where they branch in a complex manner. In some of the dye injection experiments, dye transfer from the injected cell to neighboring cells was observed. Freeze fracture of the bag cell clusters and their surrounding connective tissue revealed numerous gap junctions on bag cell processes within the clusters as well as on more distal processes. We have also examined the morphology and coupling between bag cells in primary culture. As in the intact ganglion, bag cells in culture were found to be multipolar. All pairs of bag cells whose somata or processes had formed contacts in culture were electrically coupled. The strongest coupling was observed between pairs of cells whose somata appeared closely apposed. In these cases transfer of Lucifer Yellow between cells could also be observed. It is therefore likely that the synchrony of bag cell action potentials during a bag cell afterdischarge is a result of coupling between individual cells in the bag cell cluster.


Photomechanical migrations of pigment granules along the retinula cells of the crayfish. The light-dependent migrations of proximal pigment granules along the photoreceptors of the crayfish compound-eye were studied in isolated retinas and eyestalks. The extent and kinetics of movement in each direction were found quantitatively equivalent to those observed in the organ in situ. These and other features make these cells to appear as intrinsically independent pigmentary effectors, directly responsive to light. During dark adaptation (DA) the pigment migrates away from the cell nucleus and accumulates along the axon in two distinct steps. Each step constitutes half of the total distance of about 180 microns and proceeds at 0.30 micron/sec. Only prolonged metabolic impairment inhibited the first phase, while the second was blocked by hypoxia, cyanide, colchicine, and D2O. The maintenance of a full DA position was also shown to be highly dependent upon metabolism. Light incidence on DA eyes is followed by an apparently monophasic expansion of the pigment from the axon towards the perikaryl region at 0.38 micron/sec. This movement was not affected by any of the foregoing agents and seems to be a passive relaxation process. Cytochalasin B had no effect on either motion. The migration in either direction has an exponential time course and is temperature dependent. Electron microscopy revealed two separate patterns of cytoplasmic organization corresponding to the cell areas where the two phases of DA occur. In the region close to the nucleus the pigment appears irregularly scattered, whereas in the axon the granules are situated arond a thick longitudinal bundle of microtubules. These results suggest the existence of two different mechanisms of pigment granule translocation operating in two separate regions of the retinula cell.


Subcellular particles involved in the translocation of proteins in rat brain. Protein translocation systems which are inhibited by vinblastine, colchicine, and low calcium concentrations have been found in the cells of the brain slice. The early steps in the translocation pathways of newly synthesized protein have been studied by use of a double-label experiment in conjunction with subcellular fractionation. Certain subcellular particles have been positioned on the pathways with reference to vinblastine-sensitive translocation steps. There appears to be many subcellular organelles that are located downstream from a vinblastine-sensitive translocation step and which receive significant quantities of translocated protein within an hour of its synthesis. Some of these organelles co-enrich with the enzyme marker 5'-AMPase. Myelinated axons, Golgi derived vesicles, and smooth and rough endoplasmic reticulum all are enriched in fractions which contain a net vinblastine-sensitive importation of protein. The major particles, which lie upstream from a vinblastine-sensitive translocation step and are net exporters of protein on this system, are found in a brain capillary fraction. It is suggested that the most likely exporter present in these capillaries are the end feet of astrocyte glial cells.


Isolation and identification of a cannabinoid-like compound from Amorpha species. The petroleum ether extracts from several plants have been screened on the plates with the chromogenic reagent Fast Blue B. salt. Extracts from different plant parts of Amorpha fruticosa, A. nanna, and A. canescens gave several spots with color and Rf values similar to those of Cannabis sativa extract. The major compound, amorphastilbol (1), was isolated by column chromatography, purified, and characterized by mp, elemental analysis, uv, ir, mass, prm, and cmr spectroscopy. Further information was obtained by analyzing the oxidation products of the compound. The evidence indicates that amorphastilbol is a phenolic stilbene terpenoid with a molecular formula of C24 H28 O2 and structural formula: (E,E)-2-(3',7'-dimethyl-2'-6'-octadienyl)-5-(2-phenylethenyl)-1,3-benzenediol. This is the first report of the isolation of a naturally-occurring stilbene derivative possessing a terpenoid moiety.


Plant anticancer agents X. Isolation of camptothecin and 9-methoxycamptothecin from Ervatamia heyneana. The anticancer activity of the roots of Ervatamia heyneana (Apocynaceae) was found to be due principally to the known alkaloid, camptothecin (1). The closely related, but less active, 9-methoxycamptothecin (2) was also obtained. This is the first reported isolation of these biogenetically interesting alkaloids from the indole alkaloid rich Apocynaceae.


Cytotoxic principles from the sap of Kalmia latifolia. Examination of the sap of Kalmia latifolia has revealed Grayanotoxin I (1), phloretin (3), and 2',6'-dihydroxy-4-methoxyacetophenone (5) as cytotoxic components. Twenty-one dihydrochalcones have been synthesized and tested for cytotoxic activity. 2'3,3'4,4'-Pentahydroxydihydrochalcone (8) has been found to be cytotoxic and to have marginal activity in vivo. Seven new dihydrochalcones are described.


Two populations of type I fibres in striated muscle from a case of neutral lipid storage disease. Percutaneous needle biopsy of the vastus lateralis muscle was performed in a patient with a generalised accumulation of neutral triglyceride. Light microscopy revealed a type I fibre predominance, with neutral lipid droplets in both fibre types but larger and with a greater quantity of lipid per unit area in the type I fibre population. Within type I fibres there were at least two populations based on the lipid droplet size and total accumulated lipid per cell. These observations are discussed, and it is concluded that they support the hypothesis of metabolic differences within the type I fibre population with respect to the use of free fatty acids as a fuel source.


The Yakovlev Collection. A pilot study of its suitability for the morphometric documentation of the human brain. A pilot study on the Yakovlev Collection in Washington, D.C. was carried out in September/October, 1977, to determine its suitability for morphometric documentation of the growth of the human brain and its structural components. The Yakovlev Collection contains complete serial sections of approximately 800 human brains which are practically unexplored with morphometric methods. The extent and quality of the Collection present a unique opportunity for enlarging into a multinational data bank for morphometric brain research.


Plant anticancer agents. IX. Constituents of Hyptis tomentosa. The twigs, leaves, and flowers of Hyptis tomentosa were found to owe their major cytotoxic activity to the presence of desoxypodophyllotoxin (4), but the two weakly cytotoxic flavones 5-hydroxy-4',6,7,8-tetramethoxy flavone (3) and 5-hydroxy-4',3,6,7,8-pentamethoxy flavone (2) also contributed to the total cytotoxicity of the crude extracts. The flavones eupatorin (6) and 5-hydroxy-3',4',6,7-tetramethoxy flavone (5) were isolated as inactive constituents, together with the lignan sesamin (1).


TLC-spectrophotometric assay of the main glycosides of red squill, a specific rodenticide. Red squill bulbs, with reported specific rodenticidal properties, have been assayed for their content of the two main glycosides, scilliroside and scillaren A, by a method depending on the separation of the glycosides from purified plant extracts by tlc followed by spectrophotometric (uv and visible) determination of the individual glycosides in the eluates. The method was found convenient for assessment of the potency of red squill bulbs.


Anomalous reinnervation as a sequel to obstetric brachial plexus palsy. In 3 patients with sequelae of brachial plexus birth injury we observed associated movements and also synchronous motor unit potentials and motor axo-axonic reflexes between different muscles, sometimes with antagonist function. To explain these synkineses is necessary to assume that there is simultaneous innervation by the same motoneurone of 2 or more "motor subunits" in different muscles. Therefore we suggest that the motoneurone branches originate proximally from the primary trunk of the brachial plexus. Careful clinical and neurophysiological study can show these complex simultaneous innervations and also suggest correct kinesiotherapy.


Immune response to isolated oligodendrocytes. Oligodendrocytes were isolated from bovine white matter and were injected with complete Freund's adjuvant (CFA) into experimental animals. Indirect immunofluorescence studies using fluoresceinated goat anti-rabbit or anti-guinea pig immunoglobulin (GARIg; GAGPIg) showed that rabbit and guinea pig anti-oligodendrocyte (RAO, GPAO) sera reacted specifically with the surface of isolated oligodendrocytes in suspension, as well as with oligodendroglia in bovine and human brain sections, and in mouse cerebellum cultures. This activity of RAO was blocked by non-fluoresceinated GARIg and by GPAO, and absorbed by oligodendrocyte preparation (OP) or whole white matter, but not by purified myelin, neuroblastoma or non-brain tissue. Low levels of anti-basic protein antibodies were found in many RAO (but not GPAO) sera by radioimmunoassay, and a few showed significant anti-galactocerebroside antibody by agglutination and radioimmunoprecipation techniques. Guinea pigs sensitized with isolated oligodendrocytes in CFA showed cell-mediated immunity (CMI) to OP as manifested by delayed type skin test and induced in vitro lymphocyte transformation. CMI to purified myelin basic protein was not detected. The demonstration of humoral and CMI to the cell responsible for the production of CNS myelin may be related to some aspects of the immunopathogenesis of demyelinating disorders.


Measles antibodies and histocompatibility types in multiple sclerosis. Measles antibody titres and HLA antigens were determined in 71 White and 11 Coloured multiple sclerosis (MS) patients and 71 White and 11 Coloured age and sex-matched controls. Measles antibody titres were determined by the hemagglutination inhibition test and HLA antigens were determined serologically by a micro-lymphocytotoxicity test. Measles antibody titres were significantly higher in MS than in control cases and this was true for both female and male patients. No association was observed between the HLA antigens, especially HLA-A3 or HLA-B7 and measles antibody titres in the sera of MS patients or controls.


A mitochondrial myopathy with a deficiency of respiratory chain NADH-CoQ reductase activity. This paper presents data on two sisters with a mitochondrial myopathy characterised by weakness, marked exercise intolerance and a fluctuating lactic acidaemia. Both patients also experienced episodes of increased weakness which could be brought on by unaccustomed activity, going without food or by taking small quantities of alcohol. Metabolic studies during exercise showed a marked and sudden rise in blood lactate and pyruvate levels. Biochemical studies in one case showed that mitochondrial respiratory rates were markedly decreased with all NAD-linked substrates tested but were normal with succinate and with TMPD + ascorbate. The mitochondrial cytochrome components were normal as determined by low temperature spectroscopy and the addition of uncoupler did not enhance state 3 respiratory rates utilising NAD-linked substrates. It was concluded, therefore, that the mitochondrial lesion was located at the level of the NADH-CoQ reductase complex.


Multiple system atrophy with autonomic failure: clinical, histological and neurochemical observations on four cases. Four cases of progressive autonomic failure are described, in all of which there were additional non-autonomic neurological abnormalities, including pyramidal, extra-pyramidal and cerebellar features. Histological examination revealed cell degeneration in the substantia nigra, putamen and intermediolateral columns of the spinal cord as a common pathological finding. In addition, 3 cases showed loss of Purkinje cells in the cerebellum and degeneration of pontine nuclei and inferior olivary nuclei. In one case there was cell loss from the locus coeruleus, caudate nucleus, vestibular nuclei and dorsal vagal nuclei. These were, therefore, cases of multiple system atrophy. Neurochemically, a common feature was a profound depletion in dopamine and noradrenaline from brain regions which are normally rich in these catecholamines. Central cholinergic systems appeared to be involved also, but to a variable degree.


Roentgenmorphological aspects of muscular pseudohypertrophy. Using special soft tissue X-ray investigations the authors have found that the increase in volume of the calf musculature in progressive muscular dystrophy does not seem to be in complete accordance with the criteria of pseudohypertrophy. It has been demonstrated that this structural alteration of the musculature does not damage the various muscles to an equal extent. It has been shown that in two cases of motoneurone lesions the total decay of the calf musculature was not followed by loss of muscle bulk. The volume of the damaged musculature remained unchanged, or increased, in consequence of the enormous increase in the fat and connective tissue. This structural alteration corresponds to the generally accepted definition of pseudohypertrophy.


Conduction velocity in hexachlorophane neuropathy: correlation between electrophysiological and histological findings. After 2-3 weeks exposure to hexachlorophane, maximum motor nerve conduction velocity in sciatic nerves of rats was reduced by 7.5% and evoked muscle action potential amplitude by 9%. Histological examination at this stage showed intramyelin oedema affecting some fibres and axonal degeneration of other fibres. After longer periods of exposure velocity and amplitude fell further. Velocity was reduced by 27% after 6-7 months treatment. In addition to intramyelin oedema and axonal degeneration, segmental demyelination was present in animals intoxicated for more than three months. There was no correlation between the degree of oedema and reduction of conduction velocity. It is concluded that intramyelin oedema has little or no effect on conduction velocity. Nodes of Ranvier are normal in the early stages of the lesion and this may contribute to the preservation of normal conduction. The electrophysiological findings can be attributed to secondary changes of axonal degeneration and segmental demyelination.


Ultrastructural observations in experimental hydrocephalus in the rabbit. Changes in the ependyma and periventricular brain tissues of the lateral, 3rd and 4th ventricles and the cervical spinal canal were studied electron-microscopically in young rabbits on the 9th day after injecting kaolin into the cisterna magna. The ependyma of the lateral ventricle overlying the white matter was notably stretched causing increased egress of CSF and disorganisation of the normal architecture of the white matter and capillaries. The neurons and glial cells close to the white matter showed edematous changes. The changes in the ependymal lining and the underlying grey matter were less severe in the dorsal part of the 3rd and the 4th ventricle. The ventral part of the 3rd ventricle was the least affected. The height and the arrangement of the ependymal cells, the surrounding grey matter with narrow interstitial spaces and the absorbing tanycytes seemed to be factors which were responsible for the minimal changes in these regions. The changes appeared to be reversible if the CSF pressure was relieved at this stage. The spinal canal remained unaffected in the majority of our hydrocephalic animals, which could probably be attributed to the type of animal and the degree of hydrocephalus.


Myotonic dystrophy associated with thyroid disease. Two patients with hereditary, clinical, electromyographical and histological data typical of myotonic dystrophy are discussed. In both there was a thyroid disorder. The first patient had primary hypothyroidism, and the second a non-toxic multinodular goiter which necessitated total thyroidectomy. The EMG findings and the muscle histopathology of both patients are commented on and compared with the changes described in hypothyroidism. The disease processes in both patients are also discussed in relation to the muscle and metabolic changes described in myotonic dystrophy. The coexistence of these two diseases is not explicable in the light of present knowledge on the basis of a known genetic predisposition. Only two similar cases of myotonic dystrophy and hypothyroidism have been reported.


Neuronal ceroid lipofuscinosis: clinical and histochemical observations in 2 cases. Two cases of neuronal ceroid lipofuscinosis are presented with detailed accounts of the clinical, histopathological and histochemical changes in the brain. In one of them, neurochemical analysis of the brain was found to be essentially normal. Despite the pathological and histochemical similarity in these two cases, the clinical forms were quite distinct. The clinical patterns are attributed to differences in the topography of neuronal involvement. The pathogenesis of this extremely rare form of neurolipidosis is discussed with reference to recent literature.


Motor innervation of the gastrocnemius muscle of wobbler and dystrophic mice. Innervation of the gastrocnemius muscle of mice from the wobbler, dystrophic and C57/BL colonies has been studied. It was found that phenotypically normal mice from each of the colonies did not differ in their innervation properties, hence suggesting no heterozygote penetrance. However, the end-plate complexity increased with age of normal mice. Functional terminal innervation ratio for both the wobbler and dystrophic gastrocnemius muscle was raised above that of the normal and many dystrophic end-plates also appeared abnormal. A study of mice from the wobbler colony manifesting a late onset hind-limb muscle degeneration (Wr/HLD) has been included and the results suggest a relatively benign form of spinal muscular atrophy.


Alterations in [3H]spiperone binding in human caudate nucleus, substantia nigra and frontal cortex in the Shy-Drager syndrome and Parkinson's disease. [3H]Spiperone binding was investigated in the caudate nucleus, substantia nigra (s. nigra) and frontal cortex of control subjects and of patients with Parkinson's disease and the Shy-Drager syndrome. Binding sites for [3H]spiperone were interpreted as dopamine receptors in caudate and s. nigra, and as 5-hydroxytryptamine (5-HT) receptors in frontal cortex. Scatchard analysis showed that the Bmax (maximal number of binding sites) in caudate was similar in the 3 groups, whereas in s. nigra the Bmax was reduced by approximately 60% in both Parkinsons disease and Shy-Drager syndrome. The dissociation constant (Kd) for [3H]spiperone binding in s. nigra was similar in the 3 groups. In caudate nucleus, the Kd was similar in control and Parkinson groups; however, there was a significant increase in the dissociation constant in the caudate nucleus from cases of Shy-Drager syndrome. No differences in binding characteristics were observed in the frontal cortex. These results are taken to reflect a loss of dopamine receptor sites in the s. nigra in both Parkinson's disease and Shy-Drager syndrome, and a reduced affinity of dopamine receptor sites in the caudate nucleus in Shy-Drager syndrome.


Conduction velocity through the somesthetic pathway in chronic renal failure. The latencies of evoked potentials recorded at different levels of the peripheral and central nervous system by median nerve stimulation were measured before and after dialysis, and compared with similar recordings in normal volunteers. Abnormally slow conduction velocity was more often found in proximal rather than in distal segments of the peripheral pathway in patients with chronic renal failure. This abnormality was not correlated with the presence of clinical signs of neuropathy or low values of motor conduction velocity, neither was it affected by dialysis. These findings support the hypothesis of peripheral nerve dysfunction secondary to metabolic derangement in uraemic patients.


Fatty acid profiles in mental disease. Part 1. Linolenate variations in schizophrenia. Lipids were isolated from 6 patients suffering from schizophrenia and also from 6 age-matched healthy controls. The extracted lipids were fractionated into erythrocyte and plasma lipids. Column and thin-layer chromatography on silica gel were employed further to isolate the extracts into sub-classes within the major neutral and polar lipid classifications. The fatty acid composition of each sub-class was then monitored by gas chromatography after transmethylation. A significantly higher proportion of linolenic acid (18:3w3) was found in schizophrenics when compared with the controls. The change was reflected in both the neutral lipids and phospholipids from plasma and erythrocytes of the patients. On average, 8.7 +/- 2.6 and 3.9 +/- 1.5 mole % linolenate/100 mg lipid extract were obtained from the plasma of patients and healthy controls, respectively, while 8.6 +/- 2.3 and 3.0 +/- 1.2 mole/% linolenate/100 mg lipid were recorded from the red blood cells. The other fatty acids investigated did not show such significant differences between patient and healthy subject. A net increase in the amount of total fatty acid was recorded in the patients and it is thought that either linolenate alone or linolenate together with other polyunsaturated fatty acids not considered here are responsible for these observations. Correlations of these findings with the pathology of schizophrenia are discussed.


Immunological observations on patients with acute cerebral vascular disease. Cell-mediated and humoral immunity was studied in 74 patients with acute cerebral vascular disease. During the first two days after the onset of disease marked changes of cell-mediated immunity were observed, manifested as a decrease in total lymphocyte count in the peripheral blood, decrease in number of T lymphocytes, depression in lymphocyte blastogenesis and production of the migration inhibition factor, and a delayed-type skin reactivity. The changes were most evident in patients with severe lesions of brain tissue resulting from primary cerebral haemorrhage and cerebral infarction with fatal outcome. In the group of patients with cerebral infarction with improvement of neurological symptoms the immunological changes were not so pronounced as in the two above-mentioned groups, the smallest changes being found in patients with subarachnoid haemorrhage. We suppose that the depression in the immunne function was caused by severe stress during the course of disease. Impairment of the immune function may increase susceptibility to infection. The humoral immune response was not so evidently changed, and the observed increase of IgA in the sera was probably present before the stroke. In cases with good clinical course some improvement in the immunological parameters was observed, but full recovery did not occur until 3 weeks after the onset of disease.


Reduced adhesiveness between skin fibroblasts from patients with Duchenne muscular dystrophy. The intercellular adhesiveness of skin fibroblasts from patients with Duchenne muscular dystrophy and normal controls has been measured by determining the collision efficencies of cells using the couette viscometer. The collision efficencies for dystrophic cells were significantly lower that those for normal cells (0.01 greater than P greater than 0.005), indicating that dystrophic cells are less adhesive than normal cells.


Somatosensory and autonomic neuropathy as the only manifestation of long standing leprosy. The clinical and neuropathological findings in a patient with "neuritic" leprosy are described. In this rare form of leprosy, skin changes are only minimal or absent and the diagnosis can be established only by nerve biopsy.


Considerations on the operative results in a group of elderly neurosurgical patients. 536 patients from 60 to 84 years old, operated on for neurosurgical lesions, are evaluated with reference to post-operative mortality rate related to the type of pathology. 83 deaths (15.6%) occurred in this series. Mortality rate increases progressively with advancing age. It is outlined that the aged patients have lesser chances of surgical success, but the present data induce to consider with greater favour the outcome of these patients.


Uptake of L-ascorbic acid and L-dehydroascorbic acid by human erythrocytes and HeLa cells. Uptake of AsA and DAsA by human cells, i.e., erythrocytes and HeLa cells, was examined in vitro. AsA was taken up very slowly, but DAsA was taken up very rapidly by erythrocytes to establish equilibrium after 1 minute. Uptake of the vitamins by HeLa cells was similar to that by erythrocytes, except there was an uptake of DAsA that reached saturation after 5 minutes. The DAsA taken up was reduced in part to AsA and the concentrations of DAsA inside and outside the cells became almost equal. GSH was responsible for this reduction. Although DAsA was evidently a more permeant form than AsA in the case of human cells, the relevance of this to the uptake of vitamin C by the tissues in vivo remains uncertain.


Deep controlled hypotension with sodium nitroprusside in the surgical treatment of intracranial arterial aneurysms. The authors report 73 cases of intracranial arterial aneurysms operated on under deep controlled hypotension--i.e. hypotension below 60 mmHg of systolic arterial pressure (s.a.p.)--. Deep hypotension was induced by Sodium Nitroprusside (SNP). No problems were encountered in order to reach or to maintain deep hypotension. SNP showed to be an easy hypotensive agent, without toxicity at the recommended dosage. Fifty-nine patients were operated on between 40 and 25 mmHg of s.a.p. In 55 patients deep hypotension lasted for 30 minutes or more, reaching 2 hours in 3 patients. Surgical results were excellent, in regard either to the control of bleeding, either to the dissection of the aneurysm. Clinical results were evaluated by comparison with 146 patients operated on under normal pressure (group of control); no complications were clearly related to deep hypotension per se. However, the authors stress the risks of deep hypotension in early surgery, due to the possible association to vascular spasm.


Myoclonic syndrome and dentate nucleus lesion after excision of giant acoustic neurinoma. The authors describe one case of a Myoclonic Syndrome appeared after the excision  of a giant acoustic neurinoma. On the basis of autoptic studies, Myoclonic Syndromes, similar to the one reported here, have been shown to be associated to lesions of the Dentate Nucleus. Cranial computed tomography indicates, in our case, a cerebellar lesion localized in the Dentate Nucleus region. This figure allows the authors to correlate "in vivo" the anatomo-clinical data.


Brain tumor with ipsilateral cerebral hemiatrophy in children. A series of six cases of cerebral tumor with ipsilateral cerebral hemiatrophy, including four cases admitted at our institute, were studied. Various common clinical features were noted in these six cases. The mechanism whereby ipsilateral hemiatrophy of the cerebrum arises from brain tumor has been discussed on the basis of symptomatologic and clinicopathologic findings noted in these 6 cases. 1) The onset of the disease was between 8 and 14 years of age with a mean of 11 years and 8 months; thus all the 6 patients being juvenile. 2) Presenting symptoms developed from 1 year and 2 months to 4 years before admission, with an average of 2 years and 1 month. The clinical course was therefore relatively chronic in every case. 3) Presenting symptoms were: decline of school work, hemiparesis and loss of consciousness. These symptoms were all progressive throughout the course. The principal symptoms were hemiparesis, hemihypoesthesia, character and emotional changes, deterioration of mental faculties and behavioral abnormalities. No sign or symptom of significant increase of intracranial pressure were observed in any case. 4) Ipsilateral cerebral hemiatrophy on the tumor side was evidenced by carotid angiography and by pneumoencephalography. 5) The common site of tumor in this series was the thalamus and its surrounding areas. 6) The tumor was invariably a pinealoma which seemed to be ectopic in every case. 7) The obtained histopathological findings suggest that the ipsilateral cerebral hemiatrophy was due to thinning of the cerebral cortex with degeneration and disappearance of ganglion cells, demyelination in the subcortex and destruction of axons. Our speculated mechanism of ipsilateral cerebral hemiatrophy due to thalamic tumor is that thalamic tumor causes the degeneration and disappearance of thalamic ganglion cells and nerve fibers, consequently occurring secondary Waller's degeneration of afferent and projecting fibers from the thalamus as well as retrograde degeneration of efferent fibers, thus resulting in an extensive atrophy of the cerebral cortex and subcortical tissue.


Extravasation of contrast medium from cerebral aneurysmal rupture during angiography (remarks on four cases). The authors report four cases of contrast material extravasation during carotid angiography from cerebral aneurysmal rupture. The thesis of a coincidental event not due to an increase in the intraarterial pressure, is supported. The poor prognosis of these bleedings, detectable on angiography, is underlined and the questionable toxic effect of contrast material in the subarachnoidal space is discussed.


Cervical intramedullary abscess (extirpation by means of microsurgical techniques). A case of radical excision of an intramedullary abscess is described. Microsurgical techniques permit a bolder operation than the aspiration and/or drainage intervention currently performed.


Motion and vision. II. Stabilized spatio-temporal threshold surface. The stabilized contrast-sensitivity function measured at a constant retinal velocity is tuned to a particular spatial frequency, which is inversely related to the velocity chosen. The Fourier transforms of these constant-velocity passbands have the same form as retinal receptive fields of various sizes. At low velocities, in the range of the natural drift motions of the eye, the stabilized contrast-sensitivity function matches the normal, unstablized result. At higher velocities (corresponding to motions of objects in the environment), this curve maintains the same shape but shifts toward lower spatial frequencies. The constant-velocity passband is displaced across the spatio-temporal frequency domain in a manner that is almost symmetric about the constant-velocity plane at v = 2 deg/s. Interpolating these diagonal profiles by a suitable analytic expression, we construct the spatio-temporal threshold surface for stabilized vision, and display its properties in terms of the usual frequency parameters; e.g., at low spatial frequencies, the temporal response becomes nearly independent of spatial frequency, while at low temporal frequencies, the spatial response becomes independent of temporal frequency.


Choroid plexus carcinoma (a case report). The authors report one case of choroid plexus carcinoma of the fourth ventricle; they also review all cases reported in the literature and emphasize the histological criteria which must be followed employing the most modern radiological techniques in order to exclude especially metastatized tumors in other organs.


Response of visual mechanisms to stimulus onsets and offsets. Transient and sustained visual mechanisms were studied with single, flickering bars of various widths. Wide bars were largely detected on the basis of temporal luminance transients whereas thin bars were detected on the basis of the sustained contrast. A rapidly flickering uniform field selectively masked wide flickering bars, which suggests that different mechanisms detect wide versus thin flickering bars. For coarse spatial patterns, stimulus onsets were slightly more visible than stimulus offsets, and the response to onsets and offsets approximately summated.


Evaluation of color discrimination in the white region. Reference and test stimuli were produced on two separate color television screens to evaluate the color discrimination ability of the human eye for near-white colors. Each test stimulus had a luminance approximately equal to that of the reference, but was slightly different in chromaticity, e.g., [deltax] less than 0.01, [deltay] less than 0.01. The evaluation involved 20 persons observing 26 sets of color stimuli of 16-cd/m2 luminance, and 21 persons observing sets of color stimuli of 253 cd/m2. Observers were requested to categorize the color differences they perceived on a six-level rating scale. The results indicate that the differential thresholds for color difference of near-whites are between 4 and 8 CD (Color Difference), except in the bluish region.


Further evidence for four mechanisms mediating vision at threshold: sensitivities to complex gratings and aperiodic stimuli. It is now generally accepted that several mechanisms mediate contrast detection at threshold. Many attempts to measure the bandwidths of these mechanisms using subthreshold summation have yielded estimates suggesting very narrow frequency tuning. We have measured thresholds for three classes of stimuli: gratings containing two sinusoidal components, sums of "difference of Gaussian" (DOG) patterns, and square waves. The results of the subthreshold summation experiments with gratings are consistent with those of other studies. All of these thresholds can be predicted by a model requiring only four center-surround-type mechanisms at each retinal locus. These mechanisms have a full bandwidth at a half-height of about 1.75 octaves. Quantitative prediction of sensitivities depends critically upon spatial probability summation. It is this spatial nonlinearity that yields these somewhat conterintuitive results. The much narrower bandwidths inferred by others are due to the assumption of linearity used in their analyses.


Motion and vision. I. Stabilized images of stationary gratings. To demonstrate that eye movements have profound effects on the sine-wave contrast threshold, the author uses a new method of stabilizing the retinal image, in which the Purkinje reflections from the eye move the stimulus pattern displayed on a CRT screen. Calibration of this compensatory motion is very critical; a gain error greater than 1% may produce significant destablization. Under optimum conditions, image stabilization elevates the subject's contrast threshold by a factor of about 20; it also produces after-images with resolution greater than 12 c/deg. These results compare favorably with those obtained by other methods.


Latency of peripheral saccades.

Latency of peripheral saccades. Displaying the point of gaze to the observer in addition to a point target provides a secondary visual feedback (2VFB). Eccentric fixation is achieved using a biased 2VFB to yield an experimentally imposed "eccentric fovea." The target is suddenly moved to a new position and the task is to regain it, in the "eccentric fovea". It is found that the pattern of eye-movement response consistently starts with saccadric foveal exploration of the target, but its latency has twice the duration of a regular voluntary saccade. Practice, however, makes for the shortened latency tending asymptotically to the regular saccadic duration.


Vascular damage in acute experimental leptospirosis of the guinea-pig. The pathogenesis of the haemorrhagic diathesis in experimental leptospirosis of the guinea-pig was investigated in the lung, diaphragm and kidney. The vascular damage was found to be focal and mainly capillary. Swollen endothelium with dilated endoplasmic reticulum, enlarged mitochondriae and open junctions seemed to be the initial lesions and endothelial necrosis the final picture in all tissues. The lung capillaries showed endothelial and epithelial blebs and desquamation with many myelin figures. Capillary thrombosis was observed in the pulmonary microcirculation, probably acting as an aggravating factor and being partly responsible for the particularly impressive lung haemorrhages. The peritubular renal capillaries as well as open junctions and gaps due to necrosis also had enlarged fenestrae which were permeable to colloidal carbon particles. The paucity of micro-organisms in the vicinity of the lesions is in accordance with the toxic genesis postulated for the vascular damage in leptospirosis. It is suggested that the vascular lesions induced by leptospirosis begin with increased permeability prior to endothelial necrosis.


Persistent lymphocytosis and virus-like particles in lymphocytes of sheep inoculated with cell-free extracts derived from ovine malignant lymphomas. White cell counts of sheep inoculated in utero or at birth with cell-free extracts of ovine malignant lymphomas have been monitored for 5 yr. Of 28 inoculated sheep which have survived, 19 have shown persistent lymphocytosis. After 5 yr, no lymphomas had developed in the inoculated sheep. Electron-microscopic examination of short-term cultures of phytohaemaglutinin-stimulated lymphocytes from the sheep with persistent lymphocytosis has revealed virus-like particles in five of nine animals examined but none in similar cultures from 11 uninoculated sheep. The density of particles recovered from these cultures has been determined by centrifugation on caesium chloride isopycnic density as being 1.14--1.145 gm/microliter. These particles are not typical of oncornavirus as reported from sheep and cattle elsewhere and may represent a different type of virus or indeed be non-viral.


The morphology of serotonin-induced renal lesions in the rat. The progress of serotonin-induced renal lesions was studied over a period of 6 mth following a single intraperioneal injection of 40 mg/kg serotonin. The predominant lesion was ischaemic necrosis of tubules of patchy distribution. Parahilar areas were usually spared and a narrow subcapsular strip was less severely affected than deeper parts. The early tubular lesions appeared to be an accelerated form of the lesion of complete renal ischaemia. The necrotic tubules were soon relined by epithelium from surviving segments and became dilated. This phase of dilatation corresponded approximatly with the period of diuresis following serotonin injection and was followed by collapse and atrophy of tubules. Possible mechanisms concerned in the sequential appearance of tubular dilatation and collapse were discussed. Many collapsed tubules eventually atrophied and were associated with basement membrane thickening and round cell infiltration. Reflux of necrotic proximal tubule cytoplasm into glomerular capsular spaces occurred in the early stages of the lesion. This lesion is not specific for serotonin nephropathy and can be produced by allowing normal rat kidney to autolyse.


The development of the glands of the common bile duct. The number of glands at a constant level within the wall of the common bile duct was measured in the foetus, infant, child and adult. The number of glandular acini increases from foetal life to reach a maximum within the 1st year of life. Thereafter it remains remarkably constant. This is in contrast to the lumen and wall of the common bile duct which only reaches adult proportions in adult life. Conversely, the density of acini within the wall of the common bile duct is at a peak in early foetal life and decreases progressively throughout infancy and childhood.


The effects of dexamethasone on the cell kinetics of a murine malignant lymphoma. The effects of dexamethasone on the cell kinetics of a rapidly growing syngeneic B cell malignant lymphoma in Balb/c mice have been studied. Growth curves, stathmokinetic studies and frequency of labelled mitoses (FLM) experiments were performed in groups of dexamethasone treated and control animals. These studies showed that tumour growth was arrested after 8 days treatment at which time the tumour weights were approximately half those of control animals. Dexamethasone increased the duration of the cell cycle with a particular increase in the duration of DNA synthesis. The results indicated that the effect on tumour growth could be attributed to a reduction in the growth fraction.


An electron microscopic study of the changes induced by oestrogens on the lymph-node post-capillary venules. The changes induced in the lymph-node post-capillary venules of male and female mice, 1, 2, 4, 7, 10 and 14 days after oestrogen administration were studied in 1 micron sections and with the electron microscope. The endothelial cells of the post-capillary venules are higher in female than in male control mice. On the first and second days after Hexoestrol administration there is an increase in the number of ribosomes and polyribosomes lying free in the cytoplasm of the endothelial cells. These cells were significantly increased in height between day 2 and day 7, in both male and female Hexoestrol-receiving mice, remaining at high levels thereafter. The increase in height was accompanied by an increase in the Golgi elements which occupied the major part of the cytoplasm of the endothelial cells. Lysosomes, multivesicular bodies and signs of phagocytosis were more often seen. In contrast, the numbers of lymphocytes passing through the post-capillary venule wall were significantly decreased, probably due to a direct effect of Hexoestrol on the thymus. The relation of an oestrogenic effect on the ultrastructure of the post-capillary venules to the sex differences seen in the immune response is discussed. The possibility that this may constitute a part of a general oestrogenic effect on the reticuloendothelial system is also considered.


Oesophageal neoplasia in male Wistar rats due to parenteral di(2-hydroxypropyl)-Nitrosamine (DHPN): a combined histopathological, histochemical and electron microscopic study. Intraperitoneal di(2-hydroxypropyl)-Nitrosamine (DHPN) caused a high incidence of oesophageal squamous carcinoma in male Wistar rats, particularly in rats killed 11 or more months after the start of injections. No control rats (injected intraperitoneally with saline) developed an oesophageal neoplasms. Histopathologically, the tumours were moderately well differentiated. Histochemical studies showed minor increases in mucin staining and mast cell population and a marked increase in bacteria in tumour-bearing oesophaguses. Electron microscopy showed the tumours to be similar to, but to differ in some respects from squamous carcinomas at other sites in humans. The possible implications of this work for human disease are twofold. It could provide a model for further study of aspects of oesophageal carcinoma and it serves to remind us that all potential oesophageal carcinogens need not act during swallowing.


The cellular response to blood in the vitreous: an ultrastructural study. The cellular response to whole blood injected into the vitreous cavity of rabbits was studied by transmission and scanning electron microscopy. Inflammatory cell invasion was slow to commence (2--3 days) and was predominantly mononuclear. Although firmly established by 6 days, the cell response remained low-grade with a high proportion of giant macrophages. In addition, multinuclear giant cells were observed, even as long as 18 mth after blood injection into the vitreous, and their formation appeared to result from the fusion of young cells with older macrophages. Phagocytosis of red cells by macrophages was frequently observed, but the major pathway for red cell degradation appeared to be extracellular haemolysis. In general, the cell response was similar to that in a "low-turnover" granuloma, and it is suggested that this atypical response to blood deposits may be due to the unusual nature of the connective tissue matrix of the vitreous.


A functional assessment of macrophages from osteopetrotic mice. Macrophages from osteopetrotic mice caused less bone resorption than normal sib macrophages in culture. The bone-resorbing activity lay in the culture supernatant, and reduced activity in cultures of macrophages from osteopetrotic mice correlated with reduced glass spreading and reduced latex phagocytosis. We suggest that macrophages from osteopetrotic mice show defective phagocytic recognition of glass, latex, and bone and that this defective recognition may reflect the cause of the failure of resorption which results in osteopetrosis.