Occurrence of e antigen in acute hepatitis B. The occurrence of e antigen in 44 patients with acute hepatitis B was studied in order to determine if e was related to the outcome of the illness. In 13.6% of cases e was detected, and in none of these did the carrier state develop. The HBsAg carrier state developed in 4.6% of the patients and in none of these was e antigen detected. Anti-e was detected in only three cases. Only in the very early acute phase of illness e was detected and the time serum samples were taken for the detection of e was considered to be very significant. The occurrence of e was not found to affect the duration of HBs antigenaemia in those patients who recovered completely.


Streptococcus milleri in the appendix.

Streptococcus milleri in the appendix. The appendix was investigated as a possible habitat of Streptococcus milleri. Both normal and inflamed appendices were examined and the isolation rates compared. S. milleri was present in a quarter of the normal appendices and more than half of those associated with apendicitis--a difference that was statistically highly significant. The isolation rates throughout were indepencent of age. There was a pronounced connection between the presence of S. milleri in the appendix and the purulent manifestations of appendicitis. S. milleri was isolated from other abdominal sites associated with appendicitis. The frequency of isolation was increased by culture in an enrichment broth containing nalidixic acid and sulphadimidine.


Prolonged erythrocyte T-polyagglutination in two children with bowel disorders. In vivo erythrocyte polyagglutination of microbial origin is usually a transient condition. In two children with bowel disorders, erythrocyte T-polyagglutination persisted for 12 months in one case and for seven months in the other. Both cultures required both transfusions to support surgery. Washed red cell concentrates were transfused instead of whole blood to prevent dangerous destruction of T-transformed erythrocytes by anti-T antibodies normally present in the plasma of blood donors.


Dermatitis herpetiformis: a comparative assessment of skin and bowel abnormality. We reviewed 18 patients with a clinical diagnosis of dermatitis herpetiformis who were being treated with dapsone and were on an unrestricted diet. Diagnosis was confirmed by finding IgA deposits in the dermal papillae of unaffected skin. Dapsone was discontinued and biopsy of affected skin was carried out when the typical rash reappeared. The biopsy findings were graded according to the severity of the histological changes. Small bowel tissue from each patient was examined and graded by stereo- and routine microscopy. Thirteen specimens (72%) were stereomicroscopically abnormal; all 18 showed villous atrophy, either partial or subtotal; and in 13 (72%) the interepithelial lymphocyte count was increased. No correlation was found between the histological severity of the skin and the small bowel lesions. Seemingly the severity of the skin rash in dermatitis herpetiformis is no guide to the degree of small bowel abnormality.


A comparative study for the enumeration of peripheral blood white cell counts below 2.0 x 10(9)/1 using counting chambers and the Coulter Counter model "S". Low white cell counts are performed in many laboratories by a visual method as the method of choice. In this study, the visual count has been compared to that obtained by the Coulter Model "S". The results obtained by the two methods show very close correlation, thus allowing the Coulter Model "S" to be used with confidence for all low white cell counts provided certain precautions are taken.


Evaluation of a new test system for rubella haemagglutination inhibiting antibodies. A recently available kit for the determination of rubella haemagglutination inhibiting antibodies (Rubindex, Ortho diagnostics) was was compared with the method used routinely in this laboratory. Rubindex compared favourably in that no significant difference in titre was found in 95.1% of 287 sera tested. Difficulty occurred with some sera from cases of Mycoplasma pneumoniae infection, rheumatoid arthritis, and a small number of normal sera containing human "O" cell agglutinins. This was overcome by treatment of the sera with 2-mercaptoethanol. Rubindex had the advantage that all reagents were provided in kit form and the trypsinised human "O" cells provided had a longer shelf life than chick erythrocytes.


Light inactivation of metronidazole sensitivity discs. We found that daylight inactivated metronidazole sensitivity discs. They should therefore be stored in light-proof containers.


Endocarditis due to Cardiobacterium hominis. A case of bacterial endocarditis was caused by Cardiobacterium hominis in a 41-year-old man with mitral and aortic incompetence due to a previous episode of rheumatic fever. The main distinguishing characteristics of C. hominis are described, and the incidence of endocarditis is reviewed. After six weeks of treatment with effective bactericidal chemotherapy a microbiological cure was achieved and the patient successfully underwent mitral valve replacement and aortic valve plication.


Catecholamines and free fatty acids in myocardial infarction and angina. Total urinary catecholamines and plasma free fatty acids (FFA) were estimated serially in 50 patients with myocardial infarction (A) and in 27 cases of angina (B). A group of 24 normal healthy subjects (C) were also studied as controls. Catecholamines were significantly high (p is less than 0.001) in group A in the first 48 hours after infarction as compared to group C. Group B did not show significant variation from the normals (C). FFA also tended to increase only in group A in the first 48 hours. Both the parameters had returned to normal by 72 hours. The significance of the findings is discussed.


Aminopyrine breath test in alcoholic liver disease and in patients on enzyme-inducing drugs. The 14C-aminopyrine breath test was used to measure liver function in 14 normal subjects, 16 patients with alcoholic cirrhosis, 14 alcoholics without cirrhosis, and 29 patients taking a variety of drugs. The normal value for the breath test was 8.6 +/- 1.5%, whereas it was significantly lower (5.1 +/- 3.8%) in patients with alcoholic cirrhosis. Higher than normal values were found in some alcoholic patients without cirrhosis and in patients receiving enzyme-inducing drugs, such as phenobarbitone. There was a significant correlation between serum gamma-glutamyltransferase and breath test in these groups. Some patients with alcoholic cirrhosis may also be capable of enzyme induction.


Serum protein changes in breast cancer: a prospective study. Sixty women admitted to the King's College Hospital group for biopsy of a lump in the breast have been followed sequentially for one year. Thirty women had early operable breast cancer and 30 had benign breast disease. Each patient had 10 serum proteins measured preoperatively and postoperatively at three months and at one year. The patients with breast cancer had significantly higher levels of beta2 glycoprotein preoperatively and caeruloplasmin at one year postoperatively than those with benign breast disease. There were a number of significant correlations between serum protein levels and the progression of breast cancer as measured by the clinical score. There were significant correlations with caeruloplasmin preoperatively and at three months postoperatively. Prealbumin and haemopexin showed correlations preoperatively; alpha1 antitrypsin and beta2 glycoprotein only correlated at three months postoperatively. A longer follow-up will be required to establish the value of serum protein changes which could predict the development of metastases in patients with breast cancer.


Technique for microdissection and measurement in biopsies of human small intestine. A microdissection and measurement technique has been adapted for biopsy of human small intestine. Specimens fixed in alcohol and acetic acid are Schiff stained in bulk. Villi and crypts are then dissected out under a dissecting microscope, placed under a coverslip, examined, measured, and the number of mitoses in individual crypts counted. With this method specimens of normal small intestine have been found to have villi 500 microns to 1100 microns long and crypts 150 microns to 300 microns. These values were double those obtained when measuring sections of the same specimens stained with haematoxylin and eosin. The mean number of mitoses per crypt in normal duodenum and jejunum ranged from 1 to 12 and most of the cells in mitosis were in prophase or telophase. This rapid, sensitive, and inexpensive technique complements the available methods of measuring small intestinal architecture.


Report filing in histopathology.

Report filing in histopathology. An assessment of alternative methods of filing histopathology report forms in alphabetical order showed that orthodox card index filing is satisfactory up to about 100000 reports but, because of the need for long-term retrieval, when the reports filed exceed this number they should be copied on jacketed microfilm and a new card index file begun.


Renal histopathological changes in a child with Laurence-Moon-Biedl syndrome. This report describes a case of Laurence-Moon-Biedl syndrome identified in a 24-month-old boy. Significant renal involvement was present with right-sided vesicoureteral reflux, cystocele, urinary tract infections, and growth arrest of the right kidney. After the development of hypertension a left renal biopsy was performed to determine if bilateral renal disease was present. Histopathological and ultrastructural changes in the left kidney are described. These changes appear to be unrelated to pyelonephritis or hypertension and to be most consistent with the nephropathy of Laurence-Moon-Biedl syndrome.


Evaluation of the Hemalog D differential leucocyte counter. The main objectives of the evaluation were to (1) establish 'normal values' for the Hemalog D, (2) compare the Hemalog D with existing manual procedures, and (3) assess the machine's reliability. It proved to be a practical machine in a routine haematology laboratory. Comparison with established techniques showed systematic differences in the total white blood cell count and percentages of lymphocytes. An existing laboratory computer system was used to collect and file the data.


Cell proliferation in the Lichen planus infiltrate. Investigations by light- and electron-microscopic autoradiography. In seven patients suffering from lichen planus (LP) light- and electron-microscopic 3H-thymidine (3HT) labeling studies were performed and the following results were obtained. 1. Using the light-microscope, a large number of 3HT labeled cells can be observed in the dermal infiltrate of LP. Most of the labeled nuclei belong to mononuclear, 'round cells' while isolated endothelial cells, fibroblasts, histiocytes and mast cells could be found labeled. 2. The mean labeling index of 'round cells' in our patients was 4.27 +/- 1.57%. 3. The evaluation of the electron microscopic autoradiographs showed that, as far as 'round' cells were concerned, exclusively nuclei of cells showing the morphological criteria of stimulated lymphocytes were labeled. These findings support the view that in LP, as in allergic contact dermatitis, a high proliferative activity of lymphocytes takes place.


Effect of thiocyanate on mammary gland growth in rats. In growing rats from 3 weeks to 3 months old, 0.1% potassium thiocyanate (KSCN) decreased the plasma protein-bound iodine level by 47% and the total DNA in the mammary gland by 11%, but had no effect on the total RNA. Administration of thiocyanate in the form of 0.1, 0.3 and 0.5% KSCN during pregnancy and 14 d of lactation lowered the protein-bound iodine level by 48-66%, the total DNA by 11-47% and the total RNA by 14-63%, depending on the KSCN dosage. The 14-d-old litters of rats receiving thiocyanate weighed 4-41% less than those in the control group.


Recent advances in the pharmacology of catecholamines. The availability of dopamine and dobutamine and the possibility of combined use of sympathomimetic amines provides a broad spectrum of haemodynamic effects available for therapy. As shown in Table 2, isoproterenol produces the greatest vasodilation and norepinephrine, the greatest vasoconstriction with dobutamine and dopamine in intermediate positions. Greater flexibility can be obtained by conjoint administration of sympathomimetic amines or by administering alpha-adrenergic blocking agents or nitroprusside with dopamine or norepinephrine.


Description of the measurement of an individual's continuous sound exposure during a 31-day period. A dosimeter based on the equal energy rule with range from 55 to 110 dB was used to monitor continuously the noise exposure of one subject. The subject, who is the second author of this report, works in a relatively quiet laboratory area. The daily A-weighted average sound level was measured for each 24-h period [L(eq(24))] beginning at approximately 8:00 a.m. During the day the noise exposure associated with specific activities was noted. The 31-day average sound level was 76 dB while the daily L(eq)(24)) values varied from a low of 59 dB to a high of 83 dB. The type of activity that contributed most of the subject's total sound dose was night-time parties at private homes or nightclubs. Five such parties accounted for 42% of his total sound dose. One exposure at an automobile hobby shop and three outings at a bowling alley contributed another 27% to the total sound dose. If these outside recreational activities had been avoided, the 31-day average sound level would have been reduced to 71 dB. The problems involved in monitoring a 24-h noise exposure as well as future plans for more elaborate studies are discussed.


Signal-processing techniques in a computerized hearing aid test system. General background is given to describe the factors leading up to the implementation of a computerized hearing aid test system in a production environment. The digital measurement methods for determination of the required acoustal components such as fundamental, rms, distortion, etc., in the presence of noise are discussed. The use of the concept of the average cycle for repetitive signals is described with its advantages in a Fourier type system. An algorithm for measuring rms for nonrepetitive signals that trades off resolution for memory size is described. Features and advantages of computerized testing of hearing aids are listed.


Minimum auditory movement angle: binaural localization of moving sound sources. In the first experiment, subjects were asked to discriminate whether a sound was emanating from a moving or stationary source. The minimum audible movement angle (MAMA) thus defined was observed to increase as the source velocity increased. MAMA ranged from a low of 8.3 degrees with the slowest velocity employed (90 degrees/s) to a high of 21.2 degrees with the fastest velocity (360 degrees/s). In the second experiment, subjects were asked to localize where the moving source was, at signal on and offset. The results indicate that the apparent onset is displaced in the direction of motion and the amount of this displacement is directly related to source velocity. Less consistent results were observed with signal offset. The present results suggest that the binaural system is relatively insensitive to motion.


Piecewise--planar representation of vowel formant frequencies. The first three formant frequencies for 778 steady-state tokens of 30 nonretroflex vowel types uttered by a female speaker are found to lie close to a piecewise-planar surface (expressed numerically as 0.634F1 +0.603F2 -- 0.485F3 -- 366 = 0, for F2 greater than 0.027F1 +1692 and 0.686F1 -- 0.528F2 -- 0.501F3 +1569 = 0, otherwise). The rms distance of the vowels from this surface is only 86 Hz. The intersection between the two planes is a line of nearly constant F2, corresponding closely to the F2 of a uniform vocal tract of the same length as our speaker's. The piecewise-planar representation also suggests a way to test the hypotheses of uniform and nonuniform formant-frequency scaling between speakers.


The future of Blue Cross.

The future of Blue Cross. This paper analyzes the reasons for the rise and decline of Blue Cross, a unique American institution. Its inability to respond to the crisis in today's health system is described as nothing more than the failure of the ailing American health system to cure itself. The early rise of Blue Cross is attributed to its success in addressing pressing social needs: helping patients afford the costs of hospitalization and helping hospitals meet expenses. Its later decline is traced to several factors: the striking increase in the costs of health care; the rise of the state insurance commissioner; the anticipated passage of national health insurance; and the increased competition from commerical insurance carriers, specialty health care data and management firms and state governments. In concluding, the question is raised whether society should invest further in the future Blue Cross, a social institution which may have irrevocably lost the confidence of the general public, government and the health provider community. Four possible futures for Blue Cross are set forth: the outright collapse of several plans, a "Lockheed-type" bailout, a "Naderist" organization strongly allied with consumers, and a quasi-governmental agency.


Public policy for health manpower: nursing student loans. This paper seeks to determine the extent to which the Nursing Student Loan program (NSL) has accomplished its primary objectives of increasing the supply and effecting a more equitable geographic distribution of nurses. The history and provisions of the program are discussed and data from a survey of nursing schools on students' incomes, borrowing practices and withdrawal rates are analyzed. The major conclusion of the paper is that although NSL has fallen far short of its principal goals, it has produced some secondary benefits. A review of the program is recommended as a means of determining which activities should be emphasized to maximize its overall effectiveness.


Self-concept and psychological adjustment differences between self-identified male transsexuals and male homosexuals. Self-concept and adjustment data from anatomical males seeking sexual reassignment surgery were compared with that from a male homosexual group. Findings indicated that the homosexual group had a better self-image and was better adjusted than the sex change group. Other findings are presented that reinforce the view that the norm violations in homosexuality and transsexualism do not necessarily imply serious character damage.


Permanent partner priorities: gay and straight. Based on a design used in previous research with heterosexuals, this study assessed the permanent partner priorities of gay and straight men and women, as well as the perception of those priorities by each gender and sexual orientation. Heterosexuals and homosexuals did not differ in their rank-ordered priorities, but tended to misperceive the priorities of their own and the other groups studied. Differentials of misperception were explained by varying societal pressures experienced by homo- and heterosexual men and women. Implications based on the difference between the competitive nature of courtship and the cooperative nature of permanent pairing were drawn from the findings.


Tolerance as a correlate of experience with stigma: the case of the homosexual. Scales measuring attitudes toward various unconventional groups were presented to 100 college students and 51 homosexual respondents. Homosexual respondents expressed significantly more tolerant attitudes toward deviantly labeled groups than did student respondents. Homosexuals were also significantly less likely to place social restrictions on those who opted for unconventional alternatives. However, differences between student and homosexual respondents were smaller on the public tolerance scale. The findings suggest that although gays expressed a significantly higher amount of tolerance for other unconventional groups, they appeared to have reservations in terms of total personal acceptance.


Components of sexual identity.

Components of sexual identity. This paper examines the four components of sexual identity: biological sex, gender identity, social sex-role, and sexual orientation. Theories about the development of each component and how they combine and conflict to form the individual's sexual identity are discussed. As defined here, social sex-role includes the individual's femininity and masculinity. Sexual orientation includes the individual's physical and affectional sexual preferences for relationships with members of the same and/or opposite biological sex. This paper may help to clarify meanings of the following terms used in research on sexual identity; sex, gender, femininity, masculinity, heterosexuality, and homosexuality.


Going public: a study in the sociology of homosexual liberation. The complete process of resolving and announcing one's sexual orientation as "homosexual" is analyzed into three stages: signification, coming out, and going public. Each stage is further subdivided into steps. Not everyone passes through every step, and most persons stop well short of going public. However, the general process is found to be the same for 24 persons (the author and 23 respondents), all of whom have reached the final stage. Management of self-presentation in this process is discussed, using Goffman's concepts for "spoiled identity" (stigma). The motivation for going public is analyzed, using C. W. Mills' "vocabularies of motives."


Wastage of edible food in the home: a preliminary study. The potentially edible food which was wasted in 52 well-motivated households in and around London was collected and analysed. It contained 5 per cent of the food (and rather more of the fat) estimated to have been used during the week, although wide variations were found. Significant amounts of food were also given to animals and birds in some homes, but, when averaged over the whole sample, this only increased the wastage to 6 per cent. Wastage appeared to be related to household size with each person contributing, in effect, about 400 kJ (95 kcal) per day.


A sensitive radioimmunoassay for a component of mouse casein. Mouse casein (m.w. 22,000 daltons) has been purified by employing Sephadex G-100 and DEAE-cellulose column chromatographies. A sensitive radioimmunoassay method has been developed by using [125I]-labelled casein and antiserum elicited in rabbits after injection of glutaraldehyde-treated casein. The assay method is capable of detecting as little as 0.1 ng of casein. The use of the present radioimmunoassay method in detecting casein production in cultured mouse mammary explants has also been demonstrated.


New method for obtaining IgA-specific protease. A simple method for obtaining an active preparation of IgA-specific protease from a bacterial source is presented. In this method Streptococcus sanguis was inoculated onto the surface of a dialysis membrane on nutrient agar. Following growth, the membrane was removed from the agar surface and washed in a small volume of buffer. A solution with protease activity against IgA1 monoclonal proteins was obtained by clarification of the wash and appeared to be similar to enzyme preparations obtained by other methods.


Enhanced antibody responses to antigens presented on autologous erythrocytes. On a dose basis, antigen coupled to autologous red blood cells is 1,000--10,000-fold more efficient at inducing an antibody response than the soluble form. More than one antigen can be coupled simultaneously to the same red blood cells. Under these circumstances, prior immunization with one antigen enhances the antibody response to the other antigen, provided both antigens are coupled to the same red cell. Thus, the technique of coupling antigens to red blood cells is a means of producing high-titred antisera without the use of adjuvant and also represents a useful procedure for preparing composite antigens for probing cell-cell interaction in the immune response.


125I protein A: applications to the quantitative determination of fluid phase and cell-bound IgG. An improved method for the preparation of 125I-labelled Protein A (125I PA) of high specific and functional activity is described. 125I PA has been used in combination with purified rabbit IgG bound to a solid support to develop a competitive binding assay capable of detecting Protein A or human, rabbit and guinea pig IgG at the nanogram level. An optimal set of assay conditions was established and levels of IgG measured in normal human, rabbit and strain-2 guinea pig serum. 125I PA has also been used to detect IgG anti-Forssman antibody bound to sheep erythrocytes and to line-1 and line-10 tumor cells and as an indirect assay for tumor associated antigen in the ascitic fluid of tumor-bearing guinea pigs.


A method of increasing EA positive cells in mouse spleen lymphocytes. Treatment of mouse spleen lymphocytes with a high concentration of trypsin (1 mg/ml) increases the number of EA positive cells to include nearly all the B lymphocytes. It seems that all B lymphocytes express Fc receptors but in some cells these are hidden by other proteins present on the cell surfaces.


Otoadmittance measurements in patients with rheumatoid arthritis. Analysis of middle ear function has for many years been accomplished by acoustic impedance measurements and this has proved of great clinical value. The vectors which contribute to impedance are functions of mass, stiffness and resistance of the system and information about these components may be obtained by use of the otoadmittance meter. The shape of the tympanogram may be altered both by pathologies which change the relative magnitude of the vectors and by variation in the probe tone frequency. Patients with rheumatoid arthritis (55 ears) were compared with a series of controls (50 ears); 38% of 'rheumatoid ears' demonstrated a marked notch on the 660 Hz susceptance curve whilst only 8% of the control group showed this abnormality. The pattern suggests a decrease in the stiffness of the transducer mechanism in rheumatoid arthritis.


A multiple electrode cochlear implant.

A multiple electrode cochlear implant. The University of Melbourne Departments of Otolaryngology and Electrical Engineering (UMDOLEE) receiving and stimulating component of a multiple-electrode cochlear implant hearing prosthesis produces constant stimulation. It has a stimulating pulse shape that minimizes the production of toxic substances and loss of metal from the electrodes, and this is achieved with a biphasic rectangular waveform where the first phase is negative with respect to ground. The duration of each stimulus phase in 180 msec, which is long enough to allow low levels of current stimulation, and short enough to permit rates of 1000 pulses/second to be achieved. In order to be consistent with our present understanding of the perception of pitch, the device permits the independent stimulation of a number of electrodes. Furthermore, to electrically isolate the stimulus to small areas, there is the capacity to vary the current and set the threshold independently at individual electrodes. The phase and amplitude of the pulses to neighbouring electrodes with also be varied to assist in localizing the current flow. The pattern to stimulation to individual or groups of electrodes can also be altered to enable studies to be carried out to determine ways of conveying frequency and intensity information over a more normal dynamic range.


Tympanometric diagnosis of middle ear effusions. A review of medical records of unselected children in whom the otoscopic diagnosis of middle ear effusion was uncertain, showed that tympanometry resolved the diagnostic uncertainty with an accuracy of 88 per cent for the prediction of a dry middle ear and an accuracy of 85 per cent for predicting fluid in the middle ear. Tympanometry itself gave inconclusive findings in II per cent of cases. Tympanometry can greatly reduce the need for diagnostic aspiration of the middle ear.


A posterior pharyngeal web in sideropenic dysphagia. A case is presented in which a post-cricoid web was shown arising posteriorly instead of in the almost invariable anterior situation. The patient was not anaemic and some brief comments are made on the inconstant relationship between anaemia and the presence of a web.


The onset and establishment of spermatogenesis in rats in relation to gonadotrophin and testosterone levels. The concentrations of LH and FSH in the plasma and pituitary gland, and testosterone in the plasma and testes were measured in individual rats between 21 and 180 days of age. Spermatogenesis was quantitated in the same animals and correlations between the various parameters were calculated. The numbers of Sertoli and spermatogenic cells up to pathytene spermatocytes increased in parallel with the peripheral levels of FSH up to days 33 or 35. The concentration of FSH in the plasma started to decrease after day 55, but this decrease could not be correlated with the appearance of any cell type in the testes of the same animals; it was probably due to the high levels of peripheral testosterone at this age. Testicular and plasma levels of testosterone were closely correlated in all age groups studied. The first significant increase occurred between days 39 and 41 and coincided with an increased growth rate of the seminal vesicles and ventral prostate gland. The increase in the concentration of testosterone occurred 10 days after the concentration of LH in the plasma rose to a measurable level. Spermatogenesis had proceeded up to step 16 spermatids at this age.


Gonadotrophins, testosterone and spermatogenesis in neonatally irradiated male rats: evidence for a role of the Sertoli cell in follicle-stimulating hormone feedback. Peripheral concentrations of FSH in the male rat seem to be regulated in part by a protein hormone, inhibin, which originates from the testes. In an attempt to ascertain which type of testicular cell secretes inhibin, groups of male rats were irradiated prenatally or on days 4, 6 or 8 of postnatal life, and killed at 21, 51 or 81 days of age together with castrated and intact controls. The concentrations of FSH and LH in the pituitary gland, and FSH, LH and testosterone in the plasma were estimated for each animal, and the numbers of each class of intratubular cell in the testes were calculated. Rats irradiated neonatally had fewer Sertoli cells than controls at all ages studied, while the numbers of Sertoli cells in rats irradiated prenatally were higher than those in controls on day 21. The number of spermatogenic cells was usually decreased in rats irradiated postnatally. In the rats irradiated prenatally normal numbers of spermatogenic cells were found at day 51. Numbers of spermatogenic cells were significantly correlated with the number of Sertoli cells at the ages of 51 and 81 days. The concentrations of FSH in the plasma usually increased in the postnatally irradiated animals on days 21 and 51, but not on day 81; prenatal irradiation did not result in altered levels of FSH at any age. Peripheral levels of LH and testosterone were not affected by irradiation. The concentration of FSH in the plasma was negatively correlated with the number of Sertoli cells in all age groups, whereas significant correlations between the level of FSH and the number of spermatogenic cells were only found at days 51 and 81. It is concluded from these data that the Sertoli cell is the most likely source of inhibin.


Measurement of thyroid hormone in experimental thyroid tumours in rats. Rats treated with 131I and propylthiouracil were shown to develop thyroid tumours 7--9 months after treatment. In this group, the levels of total thyroxine and tri-iodothyronine, and free thyroxine and tri-iodothyronine in the serum were low, and that of TSH was raised. In a group of rats treated with 131I and then propylthiouracil and thyroxine, thyroid tumours were found despite normal concentrations of total and free thyroxine and tri-iodothyronine in the serum. The level of TSH in the serum was significantly raised in this group. Thyroid tumours were not found in the various control groups of rats.


A monohydroxylated metabolite of tamoxifen with potent antioestrogenic activity. The oestrogenic and antioestrogenic properties of tamoxifen and its monohydroxylated (monohydroxytamoxifen) and dihydroxylated (dihydroxytamoxifen) metabolites have been investigated in the immature rat. Whether administered orally or subcutaneously, monohydroxytamoxifen was more active than tamoxifen as an antioestrogen. Dihydroxytamoxifen was less active than tamoxifen as an antioestrogen, but this derivative alone was unable to induce a uterotrophic response. Both metabolites of tamoxifen were potent inhibitors of the binding of [3H]oestradiol to oestrogen receptors in vitro. It is possible that the metabolites play a supportive role in the antioestrogenic activity of tamoxifen. The potent activity of monohydroxytamoxifen in vivo and in vitro suggests that this compound could be an important new tool for the subcellular investigation of oestrogenic and antioestrogenic events.


Metabolism of testosterone in the anterior pituitary gland and the central nervous system of the European starling (Sturnus vulgaris). The metabolism of testosterone was studied in vitro in anterior pituitary, hypothalamic and hyperstriatal tissues taken from male European starlings in the autumn. In all the tissues studied, testosterone was converted into 5alpha-androstan-17beta-ol-3-one (5alpha-DHT), 5beta-androstan-17beta-ol-3-one (5beta-DHT), 5beta-androstane-3alpha,17beta-diol (5beta-THT), 5beta-androstane-3,-17-dione and androst-4-ene-3,17-dione. The 5alpha-DHT was produced in significantly greater amounts by the pituitary gland than by the hypothalamus and hyperstriatum. The amount of 5alpha-DHT produced, however, was very low in comparison with the amounts of 5beta-reduced metabolites. The amount of 5beta-reductase was also higher in the pituitary gland than in the two nervous tissues. The ratios between the production of 5beta-DHT, 5beta-THT and 5beta-androstane-3,17-dione were, however, different in the three tissues: 5beta-DHT was produced in the greatest quantities by the hyperstriatum, while the production of 5beta-THT, 5beta-androstane-3,17-dione and androst-4-ene-3,17-dione was greatest in pituitary tissue. The role of 5alpha- and 5beta-reduced metabolites in the pituitary gland and in the brain of birds is unknown, but some possibilities arising from the present results are discussed.


Metabolism of testosterone by forehead skin of the roebuck (Capreolus capreolus). Roebucks have a specialized region of skin on the forehead which contains sebaceous and apocrine glands that produce secretions used in territorial marking. These glands enlarge during the breeding season and regress after the rut as the testes regress. The metabolism of testosterone by this forehead skin in vitro was studied in two captive roebucks over the period of glandular enlargement and subsequent regression, and compared with that of dorsal skin. In May, June and July, both areas of skin actively metabolized testosterone and the metabolites detected were androstenedione, androstanedione, dihydrotestosterone, epiandrosterone, androsterone and 5alpha-androstanediols. There were no major differences in testosterone metabolism between the two body sites, although dorsal skin appeared to be more active in total metabolism than forehead skin. There was a peak in the extent of metabolism in June/July, with a subsequent gradual decline to December. The decline in metabolism occurred at a time when the associated glands were still enlarged, which suggests that the availability of androgen to the skin glands is determined not only by the amount of testosterone in the circulation, but also by a decrease in the metabolizing capacity of the tissue.


Effect of prostaglandin E2 on masculine sexual behaviour in the rat. Intracerebral infusion of prostaglandin E2 (PGE2) facilitated copulatory behaviour of long-term castrated rats. Castrated rats were given daily systemic injections of testosterone propionate (50 microgram) or oil vehicle, and then 30 min before behavioural testing they received an intrahypothalamic infusion of either PGE2 or saline. Rats receiving PGE2 in addition to systemic testosterone showed more copulatory behaviour than those receiving PGE2 or testosterone alone.


Effects of adrenalectomy on the release of follicle-stimulating hormone and the onset of puberty in female rats. The involvement of the adrenal gland in the release of gonadotrophins and the onset of puberty in female rats was studied. Two and four days after adrenalectomy (ADX) on either day 5 or 10 after birth, a significant decrease in the concentration of FSH was found; 4 days after ADX on either day 15 or 20, FSH concentrations had increased significantly compared with sham-operated and/or intact controls. However, in the rats adrenalectomized on day 15 or 20, the body weights were lower than in control rats. Relative uterine weights (mg/100 g body wt) in adrenalectomized rats never differed from those of control rats. A delay in the time at which vaginal opening and the first oestrus occurred was found in rats adrenalectomized at 20 or 25 days of age; however this delay was accompanied in these rats by a retardation in the gain in body weight. It is argued that the effects of ADX on both the release of gonadotrophins and the onset of puberty are primarily, and presumably exclusively, due to the effects on general bodily development (expressed in body weight). The lack of effect of ADX on uterine weight supports the hypothesis that 'oestrogen-like' products from the adrenal gland are not biologically active as oestrogens.


Concentration of transcortin in the pregnant rat and its foetuses. The concentration of transcortin in serum from foetal, neonatal, pregnant and lactating rats was measured by a single radial immunodiffusion method. A decrease in transcortin concentration in sera from foetuses and pregnant rats occurred starting on days 19 and 20 of pregnancy respectively. A more pronounced fall in transcortin concentration in foetal and maternal serum was observed after treating pregnant rats with dexamethasone. These results suggest that corticosterone may be responsible for the observed changes in transcortin concentration.


The role of Schwann cells in paradoxical regeneration in the axolotl. The experiments described here examine further the conditions under which paradoxical regeneration occurs and provide support for the hypothesis that a proximal migration of Schwann cells is responsible for the phenomenon. When only the hand is shielded from irradiation and the limb is denervated, amputation through the forearm or upper arm sometimes results in regeneration. The effects of variation in the time interval between denervation and amputation, the level of amputation and the method and number of denervations on the incidence of regeneration were investigated. The presence or absecce of viable Schwann cells at the amputation plane was deduced from the remyelination of nerves under conditions which do or do not permit paradoxical regeneration. The nerves of totally irradiated and denervated limbs remain unmyelinated following regrowth of axons and such limbs do not regenerate after amputation. When only the hand was shielded from irradiation before the limbs were denervated, the new axons became completely remyelinated and some of these limbs regenerated when amputated. It is suggested that under these conditions Schwann cells can migrate proximally and can then proliferate further to form a blastema, since they would be the only unirradiated tissue present at the amputation plane.


Growth of opossum embryos in vitro during organogenesis. Opossum embryos, explanted between primitive streak and late fetal stages, were grown in culture for periods of 20-30 H. Many of the explants had a good heartbeat and blood circulation in embryo and yolk sac after 12 h, and a few after 24 h. Growth of the embryos included formation of the neural tube and body flexures, increase in the number of somites, differentiation of the limbs and digits, and development of the amnion and allantois. Embryos explanted during the last day of gestation showed persistent and vigorous body movements in culture, particularly of the forelimbs, head and tongue.


The effects of thalidomide and two analogues on the regenerating forelimb of the newt. Oral administration (3 mg/day) of thalidomide during the dedifferentiation and early limb-bud stages of newt forelimb regeneration produced a variety of specific limb deformities. Proximal and preaxial skeletal elements were the most severely malformed, e.g. preaxial hemimelia, severe proximal deformities, and preaxial polydactyly. Likewise, oral, daily doses (3 mg) of the teratogenic analogue, EM12, on days 7 and 8 following bilateral amputation caused the same incidence and type of forelimb abnormalities as did thalidomide. Conversely, the non-teratogenic analogue, EM87, when orally administered (3 mg/day) on days 7 and 8 post-amputation resulted in a low rate of limb deformities, similar in type to those seen in control regenerates. The type of limb deformities observed in the regenerating newt forelimb following thalidomide treatment nearly mimic those seen in the human and monkey syndromes. Therefore, the newt represents a possible model for investigating some of the problems associated with thalidomide teratogenesis.


Regulation of the deficiencies along the proximal distal axis of the chick wing-bud: a quantitative analysis. The wing-bud shows zero regulation following removal of a whole slice of the proximal-distal axis from stage 22 or later. Prior to this it is possible that it may show some regulation. Some of the apparent regulation may be explained by the way in which the limb grows. The bud never shows perfect size regulation or morphallaxis. The proximal-distal axis of the bud between shoulder and wrist expands uniformly from stage 20.


Waves and periodic events during primitive streak formation in the chick. Morphogenetic movements occurring during formation of the primitive streak in the chick embryo are of a periodic nature, with a mean frequency of one pulse every 2.6 min. The period of the oscillatory movement is shown to be temperature-dependent. The onset of these pulses of movement can be seen as a slow wave starting at the posterior end of the embryo and making its way towards the anterior end. An interpretation of this behaviour is discussed.


Cytological and cytochemical studies of the necrotic area of the bulbus of the chick embryo heart: phagocytosis by developing myocardial cells. The muscular wall of the bulbus cordis of the chick embryo was studied by electron microscopy during H. H. stages 27--31. Results show that the muscle cells of the bulbus undergo necrosis during these stages. The morphology of dead cells in this area is similar to that described in other embryonic myogenic tissues. Although dead myocytes appear acid-phosphatase-negative, lysosomes may well be involved in this necrotic process as there is a significant number of cells with autolytic lesions among the neighbouring healthy muscle cells. The phagocytosis of the cell detritus resulting from the degenerative process appears to be carried out by neighbouring myocytes and by macrophages. The significance of these results is discussed both from the cytological and from the morphogenetic point of view.


Mesodermal expansion after arrest of the edge in the area vasculosa of the chick. To investigate whether mesodermal expansion in the area vasculosa is caused by tension produced by outward migration of cells either in the somatic mesoderm or at the mesodermal edge on an ectodermal substratum, stage 18--20 embryos were transferred to a culture dish. There mesodermal expansion proximal to an arrested edge could be compared with that proximal to a moving edge by measuring the amount of vascular elongation occurring in each. A proximo-distal gradient in vascular elongation rate was detected both in normal embryos in ovo and in explants. This gradient was reversed following arrest of the edge, and the rate of vascular elongation proximal to the arrested edge decreased to 60--70% of that proximal to a moving edge. Nearly all of the mesoderm producing this expansion was located in the proximal two-thirds of the area vasculosa, where vascular elongation rate on the stopped side of the explant was not significantly different from that on the moving side. Similar results were obtained in the absence of the ectoderm, and when liquid culture medium was used instead of semisolid medium. It is concluded that tensile force derived from mesodermal migration plays no role in expansion of the proximal two-thirds of the area vasculosa mesoderm.


The development of functional innervation in the chick wing-bud following truncations and deletions of the proximal-distal axis. Selections of the proximal-distal axis were removed so as to produce wings lacking entire skeletal levels. The innervation of the resulting limb from the appropriate spinal nerves was tested by electrophysiological recording, gross dissection and serial sections. Ther nerves form repeatable and ordered patterns in the modified limbs which can be readily related to the normal pattern. In general the segmental nerves only innervate their appropriate territory irrespective of its location; the route followed by the nerves is characteristic for the skeletal level they traverse. If a target is missing then so is the normal nerve branch to that region.


Development of interspecific hybrids of Mus. Artificial insemination has been used to produce interspecific mouse hybrids. Mus musculus x Mus cervicolor cervicolor hybrids failed to complete more than a few cleavage divisions but both M. musculus x M. dunni and M. musculus x M. caroli hybrids completed preimplantation development. These hybrid embryos are heterozygous for various X-linked enzymes and may provide a useful genetic system for studying X-chromosome inactivation during early development. Further development of M. muscuius x M. caroli hybrids was studied: several completed foetal development; a few survived to maturity but none has yet reproduced.


Limb-somite relationship: origin of the limb musculature. Quail-to-chick grafting experiments performed during the third day of incubation demonstrate that somites can contribute to limb development. In orthotopic recombinations, migrating cells originating from the grafted unsegmented or segmented somitic mesoderm adjacent to the wing or leg field end up in the musculature respectively of the wing or the leg, where they express exclusively myogenic properties. Thus, in these heterospecific recombinations, the anatomical muscle has a double origin: muscle bulk of somitic origin; tendons and connective tissues of somatopleural origin. Similar features are observed in heterotopic recombinations with (segmented or unsegmented) somitic mesoderm located cranially or caudally to the limb levels. In the reverse chick-to-quail grafting experiments, the somitc participation to the limb mesoderm can also be observed. But it is less regular than that obtained in the quail-to-chick recombinations, and the muscle bulk is made up in various proportions of graft-originated somitic cells and of host somatopleural cells. The possible existence of juxtaposed and interdigitated myogenic and tendinogenic compartments is discussed in view of the dissimilarity between the results of the two kinds of heterospecific recombinations.


Effects of cyclophosphamide treatment before implantation on the development of rat embryos after implantation. After treatment of pregnant rats 24 h before implantation with a single injection of cyclophosphamide (20--80 mg/kg), a dose-dependent increase in resorption was observed at term but no malformed fetuses could be found. The lowest cyclophosphamide dose that caused 100% resoprtion was 60 mg/kg. Somite number and wet weight indicated retardation of about 24 h during organogenesis. Determination of the time of implantation revealed that the developmental retardation in treated embryos was not due to delayed implantation. At implantation, 24 h after cyclophosphamide treatment, a significant and dose-dependent decrease of the cell number of blastocysts was found. Embryo transplantation experiments showed that early cyclophosphamide treatment interfered with the subsequent development of both the embryo and the mother. The decidual reaction seemed to be more affected by the treatment than the embryos. Most teratologists hold that mouse embryos after treatment in the preimplantation period either die before implantation or survive to term without being malformed. The present study, however, proves that the reaction of drugs at this early stage of pregnancy is more complex than is generally assumed.


Factors affecting the time of formation of the mouse blastocoele. In normal mouse embryos developing in vivo, the first appearance of the blastocyst cavity was found to be associated more closely with developmental age, judged by cell number, than with chronological age, i.e. elapsed time since ovulation. When development was slowed by in vitro culture, formation of the blastocoele was delayed. However, cell number itself was not a critical factor, since the number of cells per embryo could be doubled or tripled or halved by experimental manipulation without substantially affecting the timing of blastocoele formation. Experiments in which one cell division was suppressed with cytochalasin-B, leading to tetraploidy, showed that the number of cell divisions since fertilization was also not critical. A possible role is suggested either for nucleocytoplasmic ratio, or for the number of nuclear or chromosomal divisions or DNA replications since fertilization, all of which increase during cleavage.


An integrated medical record and data system for primary care. Part 8: the individual patient's medical record. This is the last in a series of eight articles describing an integrated system of recording medical data as developed and used by the Family Medicine Program at the University of Rochester-Highland Hospital. Compatability of manual and automated systems has been described. The total system allows the practicing family physician to assess morbidity patterns within his/her practice more effectively, to record and monitor patient care, to perform audit, and to conduct research in primary care.


Use of a rectal hook for perirectal abscess drainage. Drainage of various types of perirectal abscesses can be facilitated by the use of a rectal hook, allowing many of these infections to be easily handled in the outpatient setting. Several types of abscesses, including ischiorectal and pelvirectal abscesses, although usually originating at the crypts of Morgagni, cannot be drained adequately by this technique. Differential diagnosis of anal pain is considered.


Can perinatal regionalization be reconciled with family-centered maternal care? Perinatal regionalization is necessary because of the enhanced quality of the outcome of high-risk pregnancies in hospitals that either have their own units or who use such centers regularly. Antenatal transfer of high-risk mothers is necessary but creates potential problems relating to separation from spouse and family. These can be minimized through closer working relationships between family physicians and perinatologists. The family physician has a responsibility to help the perinatal center increase its sensitivity to the needs of families that wish to be more involved in maternal care--even in a high-risk situation. Separation of the sick neonate from mother and family raises a set of similar but more severe problems that can also be modified by active involvement of the family physician with the perinatal team. Awareness of the interactional issues consequent to separation and attachment failures will help the family physician to anticipate and modify these unfortunate consequences of both the high-risk pregnancy itself and the neonate separated from the mother/family.


The development of a "statement of policy regarding consultations". The use of consultations in family medicine has often been misunderstood by both the persons seeking the consultations and the persons acting as consultants. A policy regarding the use of consultants has been written by the Department of Family Medicine and Practice at the Center for Health Sciences, University of Wisconsin. The statement includes a definition of "consultation," the reasons and goals for consultation, and the manner in which consultations are obtained. The policy includes the family practice residents, faculty, and patients in the decision-making process prior to all consultations.


An in-training assessment examination in family medicine: report of a pilot project. A family medicine in-training assessment examination was developed and piloted in 20 programs across the country. Core Content Review questions were used for the examination. Reporting of scores used both the traditional, normative-referenced approach, and a criterion-referenced approach. The latter permitted family medicine faculty to set passing standards for the examination. The pilot project was well received and the examination will be offered to all family medicine residency programs this year.


Family utilization of a medical center.

Family utilization of a medical center. This study shows that "high utilization families" do exist and demonstrates a method, based on the calculation of expected contact rates for individuals and families, for identifying them. The high utilization families are not composed of chance combinations of high utilization individuals. This trend becomes apparent in two member families and is statistically significant for families of three or more. High utilization families were shown to have greater numbers of social problems, economic problems, and health maintenance problems when compared to a control group.


The Age/Sex Register: estimation of the practice population. Determination of the number of patients served by a family practice is important for health services delivery and research. A sound estimate of the practice population should enhance the patient management responsibilities of the family physician. This methodology uses the Age/Sex Register to provide a series of estimations of a "teaching" unit population. Results of a sample survey indicate that 21.3% of "inactive patients" (those who have not received services from the practice in two years) still consider themselves under the care of the practice. Replication of this approach is suggested for other practices to improve planning and resource allocation.


Orientation and behavior of epithelial cell muscle processes during Hydra budding. The reorientation of the muscle processes of the ectodermal epithelial cells in Hydra attenuata has been examined during bud morphogenesis and in grafts inserted at right angles to their original orientation. The muscle processes were observed in histological preparations after staining with Mallory's Triple Stain and, in freshly fixed hydra, with polarization microscopy. Since the bud forms as an outpocketing from the parent, the ectodermal muscle processes, which run longitudinally, must reorient at some stage in order to be in the proper orientation on the bud. During the early stages of bud development, the reorientation of the ectodermal muscle processes is a passive result of the deformation of the parental tissue. Later, active reorientation occurs. The means by which muscle processes are able to reorient was studied further in rectangular grafts placed at right angles to their original orientation. In these grafts, muscle processes become aligned with those of the host in two ways: (1) in groups through the rotation of the whole graft or (2) individually, probably by retracting and then reextending in the new direction.


An allelic variant of the sperm-specific lactate dehydrogenase C4 (LDH-X) isozyme in humans. An unusual pattern of LDH isozymes was observed by gel electrophoresis of an extract of a human testis. This isozyme composition is consistent with an allelic variant of Ldh-c.


Motility patterns in mouse spermatozoa before and after capacitation. The motility patterns of mouse spermatozoa before and after capacitation are described. The latter is very characteristic, with spermatozoa describing a figure-8 pattern while remaining relatively stationary within a 3-dimensional space.


Inactivation of the sodium channel. I. Sodium current experiments. Inactivation of sodium conductance has been studied in squid axons with voltage clamp techniques and with the enzyme pronase which selectively destroys inactivation. Comparison of the sodium current before and after pronase treatment shows a lag of several hundred microseconds in the onset of inactivation after depolarization. This lag can of several hundred microseconds in the onset of inactivation after polarization. This lag can also be demonstrated with double-pulse experiments. When the membrane potential is hyperpolarized to -140 mV before depolarization, both activation and inactivation are delayed. These findings suggest that inactivation occurs only after activation are delayed. These findings suggest that inactivation occurs only after activation; i.e. that the channels must open before they can inactivate. The time constant of inactivation measured with two pulses (tau(c)) is the same as the one measured from the decay of the sodium current during a single pulse (tau(h)). For large depolarizations, steady-state inactivation becomes more incomplete as voltage increases; but it is relatively complete and appears independent of voltage when determined with a two- pulse method. This result confirms the existence of a second open state for Na channels, as proposed by Chandler and Meves (1970. J. Physiol. [Lond.]. 211:653-678). The time constant of recovery from inactivation is voltage dependent and decreases as the membrane potential is made more negative. A model for Na channels is presented which has voltage-dependent transitions between the closed and open states, and a voltage-independent transition between the open and the inactivated state. In this model the voltage dependence of inactivation is a consequence of coupling to the activation process.


Inactivation of the sodium channel. II. Gating current experiments. Gating current (Ig) has been studied in relation to inactivation of Na channels. No component of Ig has the time course of inactivation; apparently little or no charge movement is associated with this step. Inactivation nonetheless affects Ig by immobilizing about two-thirds of gating charge. Immobilization can be followed by measuring ON charge movement during a pulse and comparing it to OFF charge after the pulse. The OFF:ON ratio is near 1 for a pulse so short that no inactivation occurs, and the ratio drops to about one-third with a time course that parallels inactivation. Other correlations between inactivation and immobilization are that: (a) they have the same voltage dependence; (b) charge movement recovers with the time coures of recovery from inactivation. We interpret this to mean that the immobilized charge returns slowly to "off" position with the time course of recovery from inactivation, and that the small current generated is lost in base-line noise. At -150 mV recover is very rapid, and the immobilized charge forms a distinct slow component of current as it returns to off position. After destruction of inactivation by pronase, there is no immobilization of charge. A model is presented in which inactivation gains its voltage dependence by coupling to the activation gate.


A quantitative comparison of the effects of intracellular calcium injection and light adaptation on the photoresponse of Limulus ventral photoreceptors. Calcium ions were iontophoretically injected into ventral photoreceptors of Limulus by passing current between two intracellular pipettes. Changes in sensitivity and photoresponse time course were measured for both light adaptation and Ca++ injection. We found for some photoreceptors that there was no significant difference in the photoresponse time course for desensitization produced by light adaptation or by Ca++ injection. In other photoreceptors, the time delay of photoresponse for Ca++ injection was slightly longer than for light adaptation. The variability of threshold response amplitude and time delay decreases when the photoreceptor is desensitized by either light adaptation or Ca++ injection. The peak amplitude versus log stimulus intensity relationships for controls, light adaptation, and Ca++ injection all could be described very closely by a single template curve shifted along the log intensity axis. A 40- to 50-fold change in sensitivity is associated with a 2-fold change in photoresponse time delay for both light adaptation and Ca++ injection.


Increased intracellular sodium mimics some but not all aspects of photoreceptor adaptation in the ventral eye of Limulus. The effects of the intracellular iontophoretic injection of Na+ ions have been quantitatively compared with adaptation in ventral photoreceptors of Limulus. We find that: (a) both light adaptation and sodium injection are associated with a decrease in the variability of the threshold response amplitued; (b) both light adaptation and sodium injection are associated with a decrease in the absolute value of the temporal dispersion of the threshold response time delay; (c) the same template curve adequately fits the intensity response relationships measured under light adaptation and Na+ injection; (d) both light adaptation and Na+ injection produce a fourfold decrease in response time delay for a desensitization of 3 log units; (e) the time coures of light adaptation and dark adaptation is significantly faster than the onset of and recovery from desensitization produced by Na+ injection; (f) unlike local illumination, Na+ injection does not produce localized desensitization of the photoreceptor. These findings suggest that a rise in intracellular Na+ concentration makes at most only a minor contribution (probably less than 5%) to the total adaptation of these receptors in the intensity range we have examined (up to 3 log units above absolute threshold). However, changes in intracellular Na+ concentration may contribute to certain components of light and dark adaptation in these receptors.


Electrophysiological measurement of the number of rhodopsin molecules in single Limulus photoreceptors. Two partly independent electrophysiological methods are described for measuring the number of rhodopsin molecules (R) in single ventral photoreceptors. Method 1 is based on measurements of the relative intensity required to elicit a quantal response and the relative intensity required to half-saturate the early receptor potential (ERP). Method 2 is based on measurements of the absolute intensity required to elicit a quantal response. Both methods give values of R approximately equal to 10(9). From these and other measurements, estimates are derived for the surface density of rhodopsin (8,000/micrometer2), the charge movement during the ERP per isomerized rhodopsin (20 X 10(-21) C), and the half-time for thermal isomerization of rhodopsin (36yr).


Accelerating effect of 2,4,6-trinitrophenol on the glycolytic rate of human red cells. A number of instantaneous changes occurred when picrate was added to a suspension of human red cells in steady state with respect to glycolysis and ion distribution across the membrane at pH 7.40. The rate of glycolysis increased, without change in glycolytic quotient, to a new steady-state value, the effect reaching a maximum of 1.75 times the rate of the control at 0.5 mM picrate. Inorganic phosphate (P(i)) was released at a relatively constant rate, increasing with picrate concentration to 1.0 mmol P(i)/liter cells x h at 5-6 mM picrate. The steady- state concentrations of ATP and 1,3-diphosphoglycerate (1,3-DPG) decreased to new stable values within 15-45 min after the addition of picrate. The ATP level was affected only at picrate concentrations of 1 mM or more, and the level of ATP stabilized at 75 percent of the control values at 4 mM of picrate. In contrast, 1,3-DPG concentrations decreased to 40 percent of the control value of 0.5 mM picrate. Higher concentrations of picrate resulted in only a small additional decrease in the stationary concentration of 1,3-DGP. A net efflux of cellular potassium at constant rate took place. This net efflux was an almost linear function of picrate concentration in the range of 0.1-3 mM. At the latter concentration the net efflux amounted to about 2.7 meq/liter cells x h and a further increase in picrate concentration caused only a minor increase in the potassium efflux. Possible mechanisms for the effects of picrate on human red cell glycolysis are discussed.


A mechanism for Na/Ca transport.

A mechanism for Na/Ca transport. A model is developed which requires the binding of 4 Na+ to a carrier before a Ca binding site is induced on the opposite side of the membrane. Upon binding Ca, this carrier translocates Na and Ca. The existence of partially Na-loaded but nonmobile forms for the carrier (NaX, Na2X, Na3X) suffices to explain both the activating and the inhibitory effects of Na on the Ca transport reaction. Analytical expressions for Ca efflux and influx in terms of [Na]o, [Na]i, [Ca]o, [Ca]i, and Em are developed for the Na/Ca exchange system at equilibrium; these provide for a quantitative description of Ca fluxes. Under nonequilibrium conditions, appropriate modifications of the flux equations can be developed. These show a dependence of Ca efflux on [Ca]o and of Ca influx on [Ca]i. The large effect of internal ATP on Ca efflux and influx in squid axons, with no change in net Ca flux, can be understood on the single assumption that ATP changes the affinity of the carrier for Na at both faces of the membrane without providing an energy input to the transport reaction.


Mechanical control of the rising phase of contraction of frog skeletal and cardiac muscle. The effect of shortening on contractile activity was studied in experiments in which shortening during the rising phase of an isotonic contraction was suddenly stopped. At the same muscle length and the same time after stimulation the rise in tension was much faster, if preceded by shortening, than during an isometric contraction, demonstrating an increase in contractile activity. In this experiment the rate of tension rise determined in various phases of contraction was proportional to the rate of isotonic shortening at the same time after stimulation. Therefore, the time course of the isotonic rising phase could be derived from the tension rise after shortening. The rate of isotonic shortening was found to be unrelated to the tension generated at various lengths and to correspond closely to the activation process induced by shortening. The length response explains differences between isotonic and isometric contractions with regard to energy release (Fenn effect) and time relations. These results extend previous work which showed that shortening during later phases of a twitch prolongs, while lengthening abbreviates contraction. Thus the length responses, which have been called shortening activation and lengthening deactivation, control activity throughout an isotonic twitch.


Sodium ions as blocking agents and charge carriers in the potassium channel of the squid giant axon. Instantaneous K channel current-voltage (I-V) relations were determined by using internally perfused squid axons. When K was the only internal cation, the I-V relation was linear for outward currents at membrane potentials up to +240 mV inside. With 25-200 mM Na plus 300 mM K in the internal solution, an N-shaped I-V curve was seen. Voltage-dependent blocking of the K channels by Na produces a region of negative slope in the I-V plot (F. Bezanilla and C. M. Armstrong. 1972. J. Gen Physiol, 60: 588). At higher voltages (greater than or equal to 160 mV) we observed a second region of increasing current and a decrease in the fraction of the K conductance blocked by Na. Internal tetraethylammonium (TEA) ions blocked currents over the whole voltage range. In a second series of experiments with K-free, Na-containing internal solutions, the I-V curve turned sharply upward about +160 mV. The current at high voltages increased with increasing internal Na concentration was largely blocked by internal TEA. These data suggest that the K channel becomes substantially more permeable to Na at high voltages. This change is apparently responsible for the relief, at high transmembrane voltages, of the blocking effect seen in axons perfused with Na plus K mixtures. Each time a Na ion passed through, vacating the blocking site, the channel would transiently allow K ions to pass through freely.


Two levels of resting potential in cardiac Purkinje fibers. In an appropriate ionic environment, the resting potential of canine cardiac purkinje fibers may have either of two value. By changing the external K concentration, [K](0), in small steps, it was shown that, in the low (1 mM) Cl, Na-containing solutions used in this study, the two levels of resting potential could be obtained only within a narrow range of [K](0) values; that range was usually found between 1 and 4 mM. Within the critical [K](0) range the resting potential could be shifted from either level to the other by the application of small current pulses. It was shown that under these conditions the steady-state current- voltage relationship was "N-shaped," and that a region of both negative slope, and negative chord conductance lay between the two stable zero-current potentials. The negative chord conductance was largely due to inward sodium current, only part of which was sensitive to tetrodotoxin (TTX). Under appropriate conditions, the negative chord conductance could be abolished by several experimental interventions and the membrane potential thereby shifted from the lower to the higher resting level: those interventions which were effective by presumably diminishing the steady-state inward current included reducing the external sodium concentration, adding TTX, or adding lidocaine; those which presumably increased the steady-state outward current included small increases in [K](0), brief depolarizations to around -20 mV, or the addition of acetylcholine chloride.


The growth and respiration of bacterial colonies. Young colonies of two swarming organisms, Bacillus subtilis and Proteus vulgaris, grew about as quickly on solid media as in liquid culture whilst four non-swarming organisms, Bacillus cereus, Enterobacter cloacae, Escherichia coli and Staphylococcus albus, all grew slower on solid than in liquid media. Oxygen uptake by young colonies of B. subtilis, followed manometrically, increased exponentially at about the same rate as unrestricted aerobic growth. All other colonies demonstrated accelerating respiration which was either not strictly exponential or, in the case of S. albus, definitely biphasic, with a fast then a slow exponential rate of increase. Actual and potential respiration was determined for each species by measuring oxygen uptake before and after resuspending the colony in liquid medium. The ratio of actual to potential respiration was largest in the flat, spreading B. subtilis and smallest in the small, hemispherical S. albus. Calculations suggest that oxygen penetrates between 31 and 41 micron into colonies of B. cereus, Ent. cloacae and E. coli and only 9 micron into colonies of S. albus.


[Genetic counselling (results of ten years experience). IV. Attitude of persons seeking counselling and reliability of the counsel (author's transl)]. The authors, from their personal experience arising from 766 consultations, show that the percentages of marriages or procreations in subjects themselves suffering from a disorder, or with affected relatives, are independent of the risk estimated for their offspring. The procreation rate in couples with affected children is lower in high risk cases and depends also on the family composition. It appears that this procreation is voluntary in the great majority of cases because there were very few terminations of pregnancy among the couples seen before procreation. The estimated risks correspond to the risks observed but the authors insist that there is a relatively high proportion (4.4 per cent) of children born with a disorder different from that which motivated the consultation.


[Bloom's syndrome. Discussion of the diagnosis concerning two cases of terminal leukemia in a sibship (author's transl)]. Two brothers developed acute leukemia, one at the age of 7 months and the other at the age of 14 months. Both suffered from a staturoponderal retardation and the same malformation syndrome. The karyotype carried out only on the second child revealed breaks and chromatid changes. A diagnosis of Fanconi's anaemia can be discarbed since no blood cytopenia preceded the leukemia. Finally, the diagnosis of Bloom's syndrome prevailed despite the absence of telangiectatic erythema and the atypical chromosomal anomalies.


[Cerebral gigantism: report on two familial cases (author's transl)]. Two cases of cerebral gigantism occurring in related boys (cousins of 3rd degree) are discussed. It is difficult to argue from these cases in favour of a precise type of hereditary transmission. The hypothesis of a dominant trait with weak penetrance cannot be excluded. A genetic heterogeneity of the Sotos syndrome is very likely.


Trisomy for the short arm of chromosome No. 10. To the authors knowledge there is a single previous report of confirmed trisomy for the short arm of chromosome No 10 (Hustinx et al., 1974). In this paper we present a further case of trisomy 10p, resulting from 3 : 1 segregation of maternal balanced translocation, t(3;10)(q;11), in a female infant aged 7 months and showing numerous somatic anomalies.


Visual perspective role-taking and field-independence among Anglo American and Mexican American children of two ages. Ability to take the perspective of another was studied among 97 5 to 6- and 7 to 9-year-old Anglo American and Mexican American boys and girls. These children were administered seven perceptual role-taking tasks and the Children's Embedded Figures Test of field-independence. Results indicated no significant cultural differences. Results were contrary to previous findings in three aspects: (a) children were able to take the role of another younger than originally theorized by Piaget; (b) role-taking and field-independence were not significantly related when age is controlled; and (c) low and inconsistent correlations among the visual perspective role-taking tasks indicate that visual perspective role-taking is not an established unidimensional construct.


Attitudes towards school among early and late maturing adolescent girls. The aim of this investigation was to test the hypothesis that early developing adolescent girls have a less favorable attitude towards school than late developers. The Ss were 104 grammar school girls of mean age 14 years 1 month. All Ss were given Fitt's test of attitude towards school. Twenty-two pairs of early and late developers, matched for chronological age, IQ, and social class, were compared with regard to their mean attitude score and their responses to individual items of the attitude scale. The early developers were found to have a significantly less favorable mean attitude score. There was also a tendency for more early developers to endorse unfavorable items and for more late developers to endorse favorable items.


Depressive mood and adolescent illicit drug use: a longitudinal analysis. Through the technique of Goodman's log linear method, longitudinal data are analyzed to clarify the relationship between depressive mood and illicit drug use among youths. A representative sample of adolescents (N = 8206) from New York State secondary schools was followed over one academic year. At one point in time, users of illicit drugs other than marihuana (multiple drug users) were significantly more depressed than either nonusers or users of marihuana only. Differing interactive relationships were found over time depending upon the drugs involved. Depressive mood was related to the onset of marihuana use among nonusers and to the termination of marihuana use among users. Depressive mood also predicted the use of other illicit drugs by marihuana users. While the beginning use of illicit drugs other than marihuana was positively associated with increased depressive mood, continued multiple drug use was related to reduced depressive mood.


Marijuana and memory intrusions.

Marijuana and memory intrusions. Sixteen college-educated male subjects were tested on free-recall lists during intoxication with marijuana extract calibrated to 0.3 mg/kg delta-9-tetrahydrocannabinol and during placebo conditions. On each testing day subjects studied six lists using a regular overt rehearsal procedure and six lists using an association-overt rehearsal procedure in which they were to rehearse alound both list items and associations to those items. Both marijuana and the association-rehearsal procedure reduced the number of correct recalls and increased the number of intrusions (nonlist items which were incorrectly recalled as having been on the list to be learned). The intrusions were divided into three categories: a) words found on prior lists; b) associates spoken during the rehearsal; or c) totally new works not previously mentioned. Marijuana significantly increased the number of new intrusions; the association-rehearsal procedure did not. This result suggests that one of the effects of marijuana on cognitive functions in humans is to increase the number of intrusive thoughts and this may be the mechanism involved in some of the thought disorder observed with marijuana intoxication.


The stress-buffering role of social support. Problems and prospects for systematic investigation. Over the pase 20 years, a sizable body of literature has developed which serves to establish that stressful life events are associated with the onset, incidence, and prevalence of a wide range of physical and psychiatric disorders. As measured by the Holmes and Rahe Social Readjustment Rating Scale, or similar instruments, the stressful life events are fundamentally sociological in nature. Yet, paradoxically, the research has been largely limited in the relevant basic sociological theory and data brought to or yielded from investigation. Recently, however, several prominent researchers have emphasized the importance of studying the role of social support systems as possible buffers or mediators of stress. The most basic objective of this paper is to contribute to the advancement of such studies by clearly identifying key empirical, theoretical and methodological problems and suggesting some approaches to their resolution. Specifically, this paper offers: a) a selective review of the essential status of empirical knowledge; b) an examination of the nature and significance of social support systems; c) clarification of methodological and theoretical problems; and d) detailed proposals for approaching problems of measurement and research design.


Personality connotations of psychiatric diagnoses. Implications for a similarity model. The major concern of this study was to identify the personality traits connotated by a number of diagnostic labels such as paranoid, schizoid, hysterical, and cyclothymic. Twenty psychiatrists were given a list of nonpsychotic personality disorders and were asked to indicate what personality traits were typically associated with them. Results showed good agreement among psychiatrists on the personality traits they believed to be implied by the diagnostic terms. A factor analysis of the ratings showed a circular configuration of relative similarity among the different diagnoses. The results are interpreted as indicating that diagnostic labels are types of codes for various sectors of an implicit space of traits, signs, and symptoms.


Mood change and magnesium. A possible interaction between magnesium and lithium? Magnesium and lithium are chemically related. Magnesium is an essential ion in many enzyme systems and lithium is of value in the treatment of manic-depressive disease. A significant sex difference in mean plasma magnesium levels is reported in 44 depressed patients. It is suggested that further studies of magnesium metabolism are indicated and that they may provide a better understanding of manic-depressive disease and the mode of action of lithium.


Strumpell's pure familial spastic paraplegia: case study and review of the literature. A family with pure Strumpell's familial paraplegia is presented. There were 11 afflicted members involving three generations. The mode of inheritance was dominant, the onset in the first decade, and in this family the disease was mild. Literature data from 104 families with 536 members dating from 1880 are tabulated. This report confirms others regarding mode of inheritance, age of onset, distribution between sexes, and disease manifestations. However, contrary to other reports, we found the dominant and recessive form of pure Strumpell's familial spastic paraplegia to be similar in severity. There are now clinical and pathological data supporting the separation of pure Strumpell's familial spastic paraplegia from the other heredodegenerative diseases of the nervous system.


Pattern reversal evoked visual potential in the diagnosis of multiple sclerosis. The pattern reversal evoked visual potential (VEP) was recorded in 37 normal subjects and in 186 patients in whom a diagnosis of multiple sclerosis (MS) was established or suspected. Taking the upper limit of normal as the mean +2.5 SD (111 ms), prolonged latency was found in 75% of definite cases of MS, 58% of probable cases, and 38% of possible cases. A smaller number of patients without prolonged latency had abnormal asymmetry of latency or low amplitude potentials. In patients with a single acute episode of neurological disease resembling MS the incidence of abnormal VEP was very low. In patients examined within three months of an episode of retrobulbar neuritis (RBN), latency was prolonged in 81% of affected eyes, a similar proportion being found in patients with a more remote history of RBN. The importance of establishing the normal for every laboratory engaged on this investigation is emphasised. Prolonged latency of the VEP is common in established MS but has not yet been shown to be a sensitive diagnostic test of the early case.


Cerebrospinal fluid absorption in primary hypoparathyroidism. Cerebrospinal fluid absorption has been studied in a patient with primary hypoparathyroidism, papilloedema, and epilepsy. A marked reduction of cerebrospinal fluid transport into plasma was demonstrated which returned to normal after correction of the hypocalcaemia.


Mood disorder as a specific complication of stroke. In an effort to discern whether cerebral vascular injuries provoke specific emotional disturbances, 20 consecutively admitted stroke patients were compared with 10 orthopaedic patients. Both groups were examined for functional disabilities (Activities of Daily Living) and for psychiatric symptoms. Reliable and valid instruments, the Hamilton Rating Scale, the Visual Analogue Mood Scale, the Present State Exam, and the Mini-Mental State Exam were employed to display the psychopathology. More of stroke patients than orthopaedic patients were depressed (45% versus 10%) even though the level of functional disability in both groups were the same. Patients with right hemisphere stroke seemed particularly vulnerable and and displayed a syndrome of irritability, loss of interest, and difficulty in concentration, in addition to depression of mood (70% of right hemisphere stroke patients versus 0% left hemisphere stroke patients and 0% orthopaedic patients). We conclude that mood disorder is a more specific complication of stroke than simply a response to the motor disability. We suggest that a controlled trial of antidepressant medication is indicated for patients with this complication.


Cerebrovascular incidents after myocardial infarction. Pathological studies show a high correlation between the degree of atheroma in coronary, cerebral, and carotid arteries. Necropsy evidence of myocardial infarction also shows a high prevalence of severe atheroma in the carotid arteries. A further pathological finding is that obstruction in cerebral and carotid circulations is commonly due to embolism from the heart. In contrast, long-term follow-up of survivors of myocardial infarction indicates a low prevalence of cerebrovascular disease. To test if this low prevalence is due to lack of clinical ascertainment, a study was made of 260 survivors of myocardial infarction followed for five years. Specific attention was given to eliciting any clinical manifestations of cerebrovascular disease. In this study it was confirmed that in survivors of myocardial infarction the prevalence of cerebrovascular disease is surprisingly low: completed strokes 4%, transient cerebral ischaemic attacks 2%. A possible explanation of the low prevalence is that after the acute episode of myocardial infarction attacks of cardiac dysrhythmia predisposing to systemic embolism become infrequent.


Clinical signs in diffuse cerebral dysfunction. Abnormal responses to 13 questions from a typical mental status examination and 32 signs of neurological dysfunction were correlated with increasing degrees of cognitive impairment as measured by the Halstead-Reitan Neuropsychological Battery. Thirteen of these factors were found to be useful predictors of diffuse cerebral dysfunction when combined into a brief screening examination for application at the bedside.


Measurement of prostaglandin E2 in cerebrospinal fluid in patients suffering from stroke. In 16 patients suffering from cerebrovascular events, prostaglandin (PG) E2 was measured in their cerebrospinal fluid and correlated with their clinical status and evolution. Prostaglandin E2 ranged from 200-3000 pg (picogram)/ml of cerebrospinal fluid. A positive correlation was found between PG E2 levels and the severity and clinical outcome of the stroke.


Excitability of lower limb myotatic reflex arcs under the influence of caloric labyrinthine stimulation. Analysis of the postural effects in man. The excitability changes of myotatic reflex arcs have been investigated in 36 volunteers by two methods (tendon reflex and tonic vibration reflex) in a bilateral invertigation of soleus, quadriceps, biceps femoris, and tibialis anterior after caloric stimulation of the labyrinth. The extensor myotatic reflexes are facilated during the irrigation and the nystagmus phases. Contrary to the soleus, quadriceps facilitation is not symmetrical during the phase of nystagmus but predominates on the side opposite to the expected axial deviation. The short biceps femoris reflexes are slightly facilitated. The postural modifications arise from differences in the degree of bilateral facilitation of the extensors.


Is malignant hyperpyrexia muscle denervated? To test the hypothesis that human muscular dystrophies may be secondary to denervation, the responses in vitro of muscle in human malignant hyperpyrexia to electrical and pharmacological stimuli have been compared with those of the denervated mouse soleus muscle. The results suggest that the muscle abnormality in malignant hyperpyrexia is different from that produced by denervation. This must cast doubt on the concept that other human muscular dystrophies are secondary to denervation.


Increased myofibrillar protein catabolism in Duchenne muscular dystrophy measured by 3-methylhistidine excretion in the urine. Myofibrillar protein catabolic rate was calculated in seven patients with Duchenne muscular dystrophy from the amount of 3-methylhistidine excreted in the urine, and found to be over three times that found in a control series when expresses as the percentage of myofibrillar protein catabolised per day. It is suggested that measurement of myofibrillar protein catabolic rate may add a useful parameter in the study of muscle disorders.


Haemorrhage into pituitary adenomas.

Haemorrhage into pituitary adenomas. Seventy cases of pituitary adenoma were analysed for evidence of haemorrhage. It was present in 18 cases. These are classified into four groups, acute, acute on chronic, chronic, and late sequelae of pituitary apoplexy, and an example of a patient in each group is given. The diagnosis and management are discussed.


Eccentric head positions reveal disorders of conjugate eye movement. The effect of head position on conjugate horizontal gaze was studied in healthy adults, in patients with multiple sclerosis without eye movement signs, and in patients with downbeat nystagmus indicative of low brain stem lesions. Displacements of gaze from primary position to 30 degrees left and right were recorded using the electro-oculogram, with the head in the primary position, and turned voluntarily to the left and right (in yaw). The quality of eye movements was noted and peak velocities of saccades were measured. The head turning test trebled the incidence of abnormal eye movements found in the multiple sclerosis patients and increased it by tenfold in the patients with downbeat nystagmus. Disorders of eye movement were also found in approximately 20--30% of healthy subjects tested. Weakness of abduction was the most common eye movement defect and appeared to be posterior internuclear ophthalmoplegia. A hypothesis is made which unifies the theoretical explanations of anterior and posterior internuclear ophthalmoplegia. The most likely cause of the disorders of eye movement observed is vertebrobasilar ischaemia induced by stretching and compression of the vertebral arteries during eccentric head posture.


Analysis of stereotyped voluntary movements at the elbow in patients with Parkinson's disease. Patients with Parkinson's disease performed several different stereotyped elbow flexion tasks, and the electromyographic (EMG) patterns from biceps and triceps were compared with previously established normal standards. The EMG pattern during a smooth flexion task was almost always abnormal and was characterized by alternating activity in biceps and triceps. The EMG patterns during a fast flexion task were also usually abnormal although they were always composed of bursts of EMG activity of normal duration appearing alternately in the agonist and antagonist muscles. These bursts, associated with movements of the limb, have a superficially similar appearance to the EMG bursts seen with tremor-at-rest, but certain physiological differences are demonstrated. This study demonstrates that both slow (ramp) and fast (ballistic) movements are clearly abnormal in these patients with disease of the basal ganglia. In a task designed to investigate antagonist inhibition before agonist activity, a majority of the patients performed normally. This suggests that, contrary to previous claims, slowness of movement (akinesia/bradykinesia) is not due either to failure to relax or to rigidity of antagonist muscle.


CSF studies on the relationship between dopamine and 5-hydroxytryptamine in Parkinsonism and other movement disorders. In Parkinson's disease, the concentration of homovanillic acid (HVA) was reduced in lumbar CSF from patients with idiopathic Parkinsonism (n = 54, P less than 0.05) and post-encephalitic Parkinsonism (n = 19, P less than 0.01). The reduction in the concentrations of 5-hydroxyindolylacetic acid (5-HIAA) was not significant, and there was no alteration in the levels of 4-hydroxy-3-methoxyphenylethylene glycol (MHPG). Treatment with L-dopa increased the concentration of HVA in the CSF (P less than 0.05) but had no effect on the levels of 5-HIAA and MHPG. Carbidopa given in combinations with L-dopa produced similar CSF concentrations of dopa as did L-dopa alone but caused less than half the rise in HVA. Fourteen patients who became functionally independent on treatment with L-dopa had higher 5-HIAA levels than 23 patients  who showed no such improvement (P less than 0.001), suggesting that intact 5-hydroxyltryptamine neurones may be important in the therapeutic response to L-dopa. In a variety of movement disorders, the levels of HVA, 5-HIAA, and MHPG were not significantly different from age-matched controls. Treatment with tetrabenazine did not significantly alter the metabolite levels in patients in whom it produced either improvement, or side effects.


Bromocriptine alone or associated with L-dopa plus benserazide in Parkinson's disease. Twenty-six patients affected by Parkinson's disease were treated with a 2-Br-alpha-ergocriptine (CB 154): 14 cases were given CB 154 alone, and 12 were given CB 154 along with L-dopa plus benserazide (Madopar). Both CB 154 and combined therapy (CB 154+Madopar) induced a significant improvement in total disability score, tremor, rigidity, akinesia, self-sufficiency, and some motor performance tests (dynamic tests). No significant difference was found between results obtained with CB 154 therapy and with Madopar treatment, while the improvement induced by combined therapy (CB 154+Madopar) was significantly higher than that obtained by Madopar alone. The averse reactions caused by CB 154 alone or associated with Madopar are similar to those observed during other dopaminergic treatment. CB 154 alone or combined with Madopar appears to be a useful advance in the management of Parkinson's disease.


Further motor unit studies in Duchenne muscular dystrophy. Numbers of functioning motor units have been estimated in 124 muscles of boys with Duchenne dystrophy; some of the patients were studied on several occasions. In the distal muscles examined (extensor digitorum brevis, thenar, and hypothenar muscles) the losses of units were probably present at birth and did not decrease with age. In contrast, the numbers of units and of excitable muscle fibres in the soleus muscles declined significantly, especially between the ages of 9 and 12 years.


Implications of longitudinal muscle fibre splitting in neurogenic and myopathic disorders. Histological and electromyographic studies indicate that longitudinal muscle fibre splitting is a common finding in neuromuscular disorders. Separated fragments derived by splitting may undergo degeneration or enlarge to become separate, innervated fibres, thus leading to an increased number of fibres within motor units. Splitting may, therefore, lead to the formation of clusters of fibres of uniform histochemical type, but of variable diameter and length, both in neurogenic and in myopathic disorders. Fibre splitting is thus a factor leading to functional compensation in these disorders.


Electrophysiological findings in pressure palsy of the brachial plexus. Two patients with signs and symptoms of paralysis of the brachial plexus, caused by compression during surgery in one (case 1) and by a knapsack in the other (case 2), were examined. The characteristic electrophysiological findings were: (i) severe attenuation of amplitude of motor and sensory nerve action potentials evoked or recorded above the site of nerve injury compared to those evoked or recorded below, and (ii) slowing of motor and sensory conduction across the damaged area. Case 1 made a complete recovery clinically and electrophysiologically; EMG in case 2 suggested the presence of Wallerian degeneration. The palsies were classified as a local demyelinating block alone (case 1) or combined with axonal loss (case 2).


Bilateral occlusion of basilar artery branches. In a case in which the patient became totally paralysed except for blinking and vertical eye movements, microscopic serial sections of the pons showed bilateral infarcts which were due to occlusion of two small basilar branch arteries, one on each side. One basilar branch was occluded by an atheroma lying at its junction with the basilar artery and the other by an intramural dissection within the wall of the basilar artery. This case provides the clinico-pathological correlation for two further basilar branch infarcts. An unusual finding was that one of the branch arteries supplied the basis pontis and medulla bilaterally.


Abducens nerve palsy as initial symptom of trigeminal schwannoma. The insidious onset and slow progression of symptoms may cause delay in the recognition of trigeminal schwannomas. Two cases with abducens nerve palsy as an initial symptom are reported, in both of whom the tumour was growing mainly below and anterior to the intracavernous portion of the internal carotid artery. Early detection of clinical symptoms and thorough radiological investigations are important in the early diagnosis of these lesions.


Passive ocular proptosis.

Passive ocular proptosis. Two patients with oculomotor neuropathy demonstrated passive ocular proptosis. In both instances, there was no evidence of a pathological process exerting a vector of force through the orbital opening. The proptosis is caused by a combination of the loss of the normal backward force exerted by the ocular recti muscles and the presence of a small anteriorly directed force exerted by the ocular obliques. Computerized tomography of the orbital and retro-orbital regions was of value in establishing the diagnosis and excluding orbital disease in one patient. The role of computerized tomography in the evaluation of the patient with ocular proptosis is discussed.


Histopathological variability in 'standardised' spinal cord trauma. Feline spinal cords were traumatised by the weight dropping technique. Five trauma groups were studied (5 g X 80 cm, 10 g X 40 cm, 20 g X 20 cm, 40 g X 10 cm, and 80 g X 5 cm), each having a 'standardised' injury of '400 g--cm.' The spinal cords were sectioned serially two hours after contusion and examined by light microscopy. Relative to the larger weights falling from lesser heights, the smaller weights falling from greater heights were associated with less haemorrhage, oedema, axonal disruption, and myelin fragmentation as well as a smaller volume of grey matter containing altered anterior horn cells. In all trauma groups the cortical evoked responses disappeared at the time of the injury and did not reappear. Even though each trauma group received a '400 g--cm' contusion, each weight--height combination was associated with differing degrees of histopathological alterations. A plea is made for more accurate quantitation of experimental spinal cord trauma than the 'g--cm' unit.