Anticonnective tissue and other antitissue 'antibodies' in the sera of patients with coeliac disease compared with the findings in a mixed hospital population.

Serum IgG specificities directed against various components of basement membrane and reticulin have been described, and their incidence in 138 patients with coeliac disease has been compared with that in 110 hospital inpatients, 100 normal blood donors, and 1441 other patients. A wide variety of antitissue specificities were observed but only a few appeared to be of any significance. The 'antireticulin' specificities have been subdivided into different groups according to their distinctive histological staining patterns. Specificity directed primarily against endothelial basement membrane was found most frequently in the sera of patients with hiatus hernia (35%) or coeliac disease (22%). The same specificity was also observed in patients with myasthenia gravis and to a lesser extent in Crohn's disease and in a mixed group of patients with unspecified organic gastrointestinal disease. An epithelial basement membrane reactivity was found in patients with rheumatoid arthritis but only rarely in other conditions. Staining of perivascular connective tissue represented a third type of 'antireticulin' specificity. It was found only rarely, although in coeliac disease this reactivity was found more frequently in combination with other connective tissue specificities.


A rapidly produced 125I labelled autologous fibrinogen: in vitro properties and preliminary metabolic studies in man.

The properties of fibrinogen extracted by a precipitation method using glycine at ambient temperatures near neutral pH are described. The simple and reproducible method gives a 73% yield of high purity plasminogen-free fibrinogen in 45 minutes from small volumes of plasma. The protein extract was labelled with 125I using chloramine-T under conditions optimal for fibrinogen stability. The extraction procedure, radio-iodination, desalting, and sterilization take only 70 minutes for completion from the time donor blood is received in the laboratory. The methods, using a specially developed extraction vessel and desalting/sterilizing column, can be used in a small hospital laboratory. Autologous fibrinogen can thus be extracted from patients' blood, eliminating the risk of transmitting hepatitis when it is re-administered. The autologous material, which is 97% clottable and contains less than 0-05% free iodide, is being routinely used as a diagnostic tool in the detection of deep vein thrombosis. The high purity of the preparation facilitates metabolic studies and in vitro experimental work. In vivo results show a mean half-life in three normal volunteers of 3-95 days and a catabolic rate of 25-23% per day with the extravascular space estimated as 24-86%. In 30 surgical patients an expected reduced half-life in plasma was determined with a mean of 3-1 days.


Iliac bone marrow mast cells in relation to the renal osteodystrophy of patients treated by haemodialysis.

Mast cells have been counted in iliac bone biopsies from patients with chronic renal failure treated by haemodialysis, and attempts made to relate mast cells to the various features of azotaemic renal osteodystrophy. There was a significant increase in the number of marrow mast cells in comparison with controls, and haemodialysis has no favourable effect on the marrow mast cell hyperplasia which occurs in chronic renal failure. There was a general tendency towards greater numbers of mast cells in cases with most marked ostetis fibrosa but it was not possible consistently to relate hyperparathyroidism to mast cell numbers. Patients treated by parathyroidectomy, aluminium hydroxide, or the newer vitamin D metabolites failed to show any consistent fall in marrow mast cell numbers in spite of improvement in the ostetis fibrosa. The number of marrow mast cells was related to the duration of haemodialysis and to the amount of osteoid present and iversely to the percentage mineralization of bone. It was not possible to identify any causal relationship between the presence or severity of osteomalacia and the number of mast cells in the haemodialysed patients although mast cell hyperplasia was also observed in patients with osteomalacia unassociated with renal disease.


Comparative study of two systems for detecting becteraemia and septicaemia.

Two blood culturing systems were compared in parallel-a semi-automated radiometric method, BACTEC1, and the conventional method used in our laboratory. BACTEC contains radioactive 14C labelled substrates and monitors the level of 14CO2 evolved by actively metabolizing bacteria. BACTEC was as efficient as the conventional method in detecting positive cultures and indicated that it was superior in detecting positive cultures earlier than the conventional system.


Isolation of oxidase-positive Gram-negative cocci not belonging to the genus Neisseria from the urogenital tract.

In a 12-month period, oxidase-positive, Gram-negative cocci showing similar characteristics in biochemical tests have been isolated from the urogenital tract of 39 male and female patients. Although these organisms superficially resemble Neisseria gonorrhoeae, biochemical characterization and the results of DNA base composition analysis indicate that they do not belong to the genus Neisseria. The relationship of these organisms to the genera Neisseria, Achromobacter, and Pseudomonas is discussed.


Computer printing and filing of microbiology reports. 1. Description of the system.

From March 1974 all reports from this microbiology department have been computer printed and filed. The system was designed to include every medically important microorganism and test. Technicians at the laboratory bench made their results computer-readable using Port-a-punch cards, and specimen details were recorded on paper-tape, allowing the full description of each specimen to appear on the report. A summary form of each microbiology phrase enabled copies of reports to be printed on wide paper with 12 to 18 reports per sheet; such copies, in alphabetical order for one day, and cumulatively for one week were used by staff answering enquiries to the office. This format could also be used for printing allthe reports for one patient. Retrieval of results from the files was easily performed and was useful to medical and laboratory staff and for control-of-infection purposes. The system was written in COBOL and was designed to be as cost-effective as possible without sacrificing accuracy; the cost of a report and its filing was 17-97 pence.


Computer printing and filing of microbiology reports. 2. Evaluation and comparison with a manual system, and comparison of two manual systems.

A manual system of microbiology reporting with a National Cash Register (NCR) form with printed names of bacteria and antiboitics required less time to compose reports than a previous manual system that involved rubber stamps and handwriting on plain report sheets. The NCR report cost 10-28 pence and, compared with a computer system, it had the advantages of simplicity and familarity, and reports were not delayed by machine breakdown, operator error, or data being incorrectly submitted. A computer reporting system for microbiology resulted in more accurate reports costing 17-97 pence each, faster and more accurate filing and recall of reports, and a greater range of analyses of reports that was valued particularly by the control-of-infection staff. Composition of computer-readable reports by technicians on Port-a-punch cards took longer than composing NCR reports. Enquiries for past results were more quickly answered from computer printouts of reports and a day book in alphabetical order.


Measuring outcomes of care in an ambulatory primary care population. A pilot study.

This study developed a practical method for determining the functional outcome status of patients in an ambulatory setting. Health status of 1,840 primary care patients in an ambulatory setting. Health status of 1,840 primary care patients was compared at three points in time: patient's usual status, status at the initial visit, and status at time of telephone follow-up. Follow-up status was also compared with the physician's expectation, which was estimated at the time of the initial visit. Of the patients, 62% showed improvement, 31% remained at the same level, and 7% deteriorated from the time of their initial clinic visit. Physicians tended to overestimate either the speed or degree with which patients return to their usual functional status; 32% of the patients studied reported themselves as being less well than usual at the time of follow-up.


Ideological goals of different health insurance plans.

Questionnaires sent to and interviews with managerial personnel in two types of health insurance organizations revealed substantial differences in their goals. Top policy makers, executive managers, and lower level management personnel (in all 165 people from four entities) were questioned. Although differences occurred among the various administrative levels, the commercial companies were more strongly oriented toward profit and growth and the prepaid group practice plans more strongly oriented toward service and community relations. These findings were confirmed by a study of the public statements of these organizations. The findings would seem to have relevance to the use of insurance companies by the government in implementation of any national health insurance program.


Self-instructional teaching of biostatistics for medical students.

A growing body of literature deals with the use of self-instructional methods for teaching biostatistics to medical students. The University of Tennessee Department of Community Medicine tested the hypothesis that, in controlled, randomized situations, learning of statistical material by self-instruction is equivalent to learning identical material by the lecture method. An analysis of student performance, in terms of the grades obtained on two separate examinations, showed that students learning by self-instruction did as well or better than their colleagues taking lectures. On the basis of these results, self-instructional biostatistics for medical students at the University of Tennessee has been selected as the major teaching method of that subject.


Medical manpower: criteria for surveillance.

A physician manpower surveillance project, undertaken in the Canadian province of Ontario, is presented as a feasible prototype, using five essential critera: 1. Personal data and population information must be linked. 2. Corresponding geographic jurisdictions must be small enough to permit the identification of manpower trends in catchment areas at the community level. 3. The type of practice must be distinguished into at least two categories: primary care physicians and second-line physicians. 4. Personal and educational data must be kept to a minimum. 5. Surveillance determinations must be made frequently, with prompt publication of data.


Regional specialization in the golden hamster's retina.

Ganglion cell swere counted and measured in whole mounts of the hamster's retina, stained with methylene blue. Their density varies between about 1,000/mm2 at the edge of the retina to about 5-6,000/mm2 in a broad area centralis centred about 1.9 mm(39 deg) directly temporal to the optic disk. Maps of cell density show a long horizontal extension of the dense area in the nasal direction. The sizes of ganglion cell somata fall into two main groups--small cells (5-11 mum diameter) and large cells (greater than 11 mum), the latter including a small proportion of giant cells (greater than 17 mum). All three classes of cells are maximal in density in the area centralis, although the small cells are relatively more numerous there. The total number of cells is about 114,000 with about 63,000 small cells and about 51,000 large. The optic nerve contains about 69,000 unmyelinated axons and about 50,000 myelinated axons, suggesting that the latter are the fibres of the larger ganglion cells. It is likely that the projections of the centres of the areae centrales of the two eyes are normally divergent in space; they are therefore not on "corresponding retinal points."


Functional organization in the visual cortex of the golden hamster.

The visual cortex of the golden hamster was studied by means of multi-unit and single unit recording, which revealed three separate retinotopic maps of the visual field in the posterior cortex. V1, corresponding to cyto-architectonic area 17, has the contralateral temporal field represented medially, the central visual field (extending about 10 deg ipsilateral) represented laterally and the lower field anteriorly. The borders of the map, especially for the upper field, seem to be more restricted than the whole visual field available to the contralateral hemiretina: V1 probably does not represent the extreme periphery of the field. A large fraction of V1 has binocular input, for up to about 50 deg lateral to the vertical midline. There is a retinotopic reversal near the representation of the vertical midline where V1 meets V2 (corresponding to the more lateral "area 18a"). There is another retinotopic reversal at the extremity of the contralateral field representation, where V1 meets Vm (the medial visual area, corresponding to "area 18"). V2 and Vm each contain a reduced mirror image version of the map in V1. Almost all isolated single units in V1 have receptive fields that can be classified as radially symmetrical (60%) or asymmetrical (35%). Symmetrical fields have ON (13%), OFF (4%), ON-OFF (30%) or "SILENT" (12%) central areas when plotted with flashing spots. There are minor but not striking differences between these groups in their field sizes, velocity preferences and so on. They almost invariably prefer moving to stationary stimuli but are not selective for orientation or direction of movement. Asymmetrical fields are of four types, three of which (type 1, 11%; type 2, 17%; and type 3, 2%) are orientation selective and resemble simple, complex and hypercomplex cells in the cat cortex. Some of these have direction as well as orientation preference. Axial movement detectors (5%) have a selectivity for one axis of motion, and thus prefer one orientation of edge, but respond equally well to movement of a spot. Vertical and horizontal orientation preferences, especially the latter, are much the most common. There is some evidence of clustering of cells according to receptive field type and, possibly, preferred orientation. Asymmetrical cells are, relatively somewhat rarer in the deeper cortical layers. Within the binocular segment, fully 89% of cells are binocularly driven and the receptive fields are similar in the two eyes. Receptive fields tend to increase in size away from the area centralis representation and, in a complementary fashion, the magnification factor decreases from up to 0.1 mm/deg at the area centralis representation to about 0.02 mm/deg for the peripheral field.


Functional organization in the superior colliculus of the golden hamster.

The superior colliculus of the golden hamster was investigated by means of multi-unit and single unit recording. The retinotopic map, which probably embraces a projection from the entire retina of the contralateral eye, is organized as in other vertebrates, with the central field represented in the anterior colliculus, the upper field medially. Magnification factor is fairly uniform and is about 0.02 mm/deg. There is a small binocular segment (where almost half of all neurones have input from the ipsilateral eye) in the anterior colliculus, representing the area of field around the area centralis and the anterior pole of the field. In the more superficial layers, units have small (about 10 deg diameter) receptive fields, which can be classified as symmetrical, responding to slow movement (80%), very fast movement detectors (6%), directional movement detectors (13%) and axial movement detectors (1%). In the deeper layers, below the stratum opticum, receptive field size increases dramatically and many cells habituate rapidly, making them sensitive only to new events. Receptive fields can be classified as movement detectors (89%), directional movement detectors (10%) and axial movement detectors (2%). All directional receptive fields, at least in the upper visual field, have an upward component in their directional preferences. About 42% of deeper layer cells have somatic sensory input, responding to light touch on the fur or whiskers of the contralateral half of the body. Some 5% of cells respond to complex sounds on the contralateral side of the animal. Many of these somatic and auditory cells also have visual receptive fields and, throughout the colliculus, there is general correspondence between the maps of visual space, auditory space and the body surface. This correlation may be important in the regulation of orienting behaviour towards novel peripheral stimuli.


Impulse conduction in the myelinated giant fibers of the earthworm. Structure and function of the dorsal nodes in the median giant fiber.

The dorsal openings in the myelin sheath of the median giant fiber (MGF) of the earthworm (Lumbricus terrestris L.) have been studied with electronmicroscopical and electrophysiological methods. The fine structure of the dorsal nodes (DN) resembles in many aspects the Ranvier nodes in vertebrate and crustacean nerve fibers. The nodal membrane directly faces the extracellular collagenous capsule of the ventral cord and displays a conspicuous electrondense undercoat. The myelin sheath of the paranode shows a characteristic differentiation into large desmosomal contracts. Recordings of the transmembrane and longitudinal surface currents along the dorsal side of the MGF during spike propagation support the view that an active inward current is restricted there to the DN. The inward current density in the DN reaches outstandingly high values similar to those measured in vertebrate nodes of Ranvier. The nodal activity can be blocked by application of tetrodotoxin and local anaesthetics. Local electrical stimulation of only one DN may suffice to elicit propagated actions potentials up and down the MGF. It is concluded that the dorsal nodes of the median giant fiber of the earthworm are highly specialized excitable structures mediating saltatory impulse conduction in these fibers.


Histochemical mapping of dopamine neurons and fiber pathways in dog mesencephalon.

A topographic mapping of dopamine (DA)-containing neurons and fibers was done mainly in the mesencephalon of the dog using the fluorescent histochemical technique of Falck and Hillarp. The extensive DA neuron system was found to be located in the ventral and medial regions of the mesencephalon; the pars compacta of the substantia nigra, the area almost corresponding to the ventral tegmental area of Tsai (which consists of three groups, a caudal, the nucleus parabrachialis pigmentosus, a ventral, the nucleus paranigralis and a rostral, the caudal part of the nucleus tegmentalis ventralis of Tsai), the nucleus linearis of the raphe, and the mesencephalic reticular formation. The nigro-neostriatal projection can be traced in the non-treated or nialamide plus L-dopa treated puppies without the lesion-degeneration technique. Most fibers arising from these DA cell groups assemble at the prerubral area and ascend just dorsal to the medial forebrain bundle. Most fibers turn laterally at the lateral hypothalamus and enter the neostriatum via the dorsal part of the subthalamic nucleus, the zona incerta and the capsula interna. These findings show that the distribution of DA neurons and the nigro-neostriatal pathway are fundamentally similar to those in other mammals. In this study, the processes of the nigral and paranigral DA neurons have been demonstrated to project into the pars reticulata in the dog.


Regeneration of Müller and Mauthner axons after spinal transection in larval lampreys.

The regeneration of large unmyelinated axons following transection of the spinal cord was studied in small larval sea lampreys (Petromyzon marinus). Individual Müller and Mauthner axons normally occur in a characteristic pattern in the spinal cord, but their positions were altered in the first several segments caudal to the lesion following regeneration. Müller axons grew out of the ventral tracts and sometimes looped back towards the brain or crossed the midline; maximum misdirection of axons occurred near the site of transection Mauthner axons frequently bifurcated. Despite the aberrant and incomplete regeneration of axons, the larvae exhibited normal coordinated swimming ,crawling, and coiling behavior.


The current status of silicone fluid in plastic and reconstructive surgery.

Sufficient experimental data have been accumulated to demonstrate that medical-grade liquid silicone in recommended doses, using proper techniques, is both safe and effective. The problem becomes one of developing a rational and safe set of treatment guidelines.


Surgery and coronary heart disease.

Surgeons are frequently confronted with a patient who has recently had a myocardial infarction, needs an operation urgently, or has a postoperative infarction. This paper examines the extreme caution necessary when surgery is scheduled for a patient with coronary heart disease.


Perspectives in malpractice.

Medical malpractice dates from Biblical days. And since then, much has been written on the subject. This article is a general overview of the historical, legal, and professional aspects of medical malpractice.


Transplantation of hair bulbs and melanocytes into leukodermic scars.

In performing transplantations of hair into places scarred and depigmented by discoid lupus erythematosus, it was found that considerable repigmentation in addition to growth of viable hairs was achieved.


Capsule anesthesiology: use of local anesthetics in dermatology.

This paper, the third of three articles, discusses the basic techniques of administering local anesthetics to the scalp, face, and neck.


Adventitious tattooing.

A hard-bristle toothbrush proves an efficient instrument for removing foreigh material impregnated into the skin via explosive or abrasive trauma.


Sex-related effects on clinicians' attributions of parental responsibility for child psychopathology.

An attempt was made to reproduce and extend previously reported data suggesting the operation of sex-related bias in clinicians' attributions of parental involvement in children's psychopathologies. More and less sex-role traditional male and female family-oriented practitioners were shown contrived profiles in which a boy or girl was described as masculine or feminine role-deficient, and apportioned maternal versus paternal blame, treatment focus, adjunctive therapy need, and likelihood of sabotage. As in the previous study, mothers were implicated slightly more than fathers and also were viewed as requiring relatively greater therapeutic attention by female than by male clinicians. However, several earlier findings were not replicated. Overall, the results offer only marginal support for the notion of sex-related practitioner bias.


Differential effects of task and reinforcement variables on the performance of three groups of behavior problem children.

In a test of Quay's model of differential response tendencies in three basic dimensions of discordant behavior, 36 delinquent boys divided into three behavior groups - Conduct Disorder, Personality Disorder, Inadequate-Immature-were compared on a verbal paired-associate task under four conditions of task structure: neutral and emotional content, simplicity and complexity; and two reward conditions: material and verbal. Predictions were that the Conduct Disorder and Inadequate-Immature group would perform optimally under conditions of simple emotional task structure and material reward as opposed to the Personality Disorder group, who would demonstrate optimal performance under verbal reinforcement and reflect an interaction effect for task complexity and emotionality. Results confirmed the basic hypothesis of differential responsiveness as a function of subject variables. Directions of the differences indicated that task variables also produced critical effects.


The effects of stress on state and trait anxiety in emotionally disturbed, normal, and delinquent children.

The effects of stress on trait and state anxiety of emotionally disturbed, normal, and delinquent children were assessed using the State-Trait Anxiety Inventory for Children (STAIC). This scale measures both transitory feelings of apprehension and tension that vary over time as a function of situational stress (A-State) and individual differences in the disposition to experience such anxiety states (A-Trait). Results indicated that A-State increased as a function of stress, whereas A-Trait was relatively stable and impervious to the temporary effects of stress. Use of the STAIC with normal and deviant populations was supported.


Standardized playroom measures as indices of hyperactivity.

A group of 16 children from a normal community population was compared with two groups of 16 children referred for clinical evaluation of hyperactivity. These three groups were matched on age, sex, and race. One of the clinic groups was matched with the community sample on IQ and social class as well, while the children in the other clinic group were mentally retarded and of somewhat lower social class. All children were observed in a standardized playroom for two 15-minute sessions, one under free play instructions and the other under instructions restricting activity and toy-changing behavior. The two groups of children referred for evaluation of hyperactivity had significantly higher playroom activity scores than controls under both instructional conditions and significantly higher toy-change scores under restrictive instructions. Parental ratings of activity were also significantly higher in both clinic groups than in the community group. The mentally retarded clinic sample did not differ from the other clinic sample on any of the measures of activity or toy switching.


Role vs. entry-level competencies in competency-based education.

The real strength of the competency-based education effort lies in its emphasis on the total program. No longer can we, as educators, ask ourselves merely: "What do I want students to learn in my course?" The studies and learning opportunities of students must meet specific objectives developed on assessed needs in the profession. The resulting output can then be evaluated against standards or a set of criteria. Since implementation of a competency-based education program requires "adaptation rather than adoption," both the role-competency and entry-level approaches are valuable. Few professionals are willing to accept totally a program or syllabus developed by someone else. However, effective adaptation requires understanding of the total concept of competency-based education. In fact, the search for totality is the heart of the competency-based movement. By viewing the framework of competency-based education and thoroughly understanding all of the components of the program, professionals should be able to utilize the ideas of others, even though they are presented in varying formats with constantly changing semantics.


Nutrition: an integral component in the health care of children. The interdisciplinary team in action.

The purpose of this paper is not to disseminate new findings or to review past research, but simply to state a progressive clinical philosophy in practical terms. Current emphasis on specialization and the simultaneous need for comprehensive health care seriously challenge the health professional's ability to provide adequate services without a well integrated interdisciplinary approach. In addition, clinical experience strongly points toward the need for individualization of treatment within this broad spectrum of interdisciplinary management. The problems of childhood allergies, epilepsy, and feeding problems are used to illustrate this concept, and the interplay between psychic and somatic factors has been highlighted as rationale for integration of nutrition in an interdisciplinary health care program for children.


Delegation of functions by dietitians to dietetic technicians.

Questionnaires were sent to 197 randomly selected hospitals in the continental United States. Replies were used as a basis for determinign the degree to which dietitians are willing to delegate tasks to dietetic technicians. No significant difference was found between the percentage of task functions clinical dietitians were willing to delegate to clinical dietetic techncians and the number that administrative dietitians were willing to delegate to administrative dietetic technicians. Dietitians who serve in both capacities are willing to delegate a significantly higher percentage of ther clinical task functions than their administrative functions. Comparing dietitians who graduated before 1968 with those graduating in 1968 or later, no significant difference was found between the two groups of administrative dietitians; however, the clinical dietitians who graduated in 1968 or later were willing to delegate significantly more duties. No significant difference was found in the average number of task functions dietitians working in different size hospitals were willing to delegate. For task functions which 33 per cent or more of dietitians were unwilling to delegate, it appears that those who do not feel this would be ideal also feel it is impractical. Dietitians who have performed a given function do not appear more or less willing to delegate it than those who have not performed that task. Thus, while a substantial number of dietitians were willing to delegate to the dietetic technician, there was also reservation as to the type of task functions, some of which the dietitians apparently feel should remain a function of the dietitian's role. This is especially true of the administrative dietitian.


Effects of rapid increase of phenylalanine intake in older PKU children.

Twelve children formerly on strick low-phenylalanine diets were allowed to change to a moderate-protein diet over a five-week period. They were observed at home by parents, in school by teachers, and in the clinic by team members, and were evaluated periodically for phenylalanine intake, serum phenylalanine levels, activity, irritability, growth, and intelligence. Growth patterns were normal for age. Dietary phenylalanine increased sharply for all children at the end of three months, then dropped at about six months, after which it rose above the three month level. Serum phenylalanine levels followed dietary intakes, and in nine cases are staying at about 20 mg. per 100 ml. or less. The three subject above 20 mg. have serum phenylalanine of 21, 23, and 25 mg. per 100 ml. One of these has had behavioral problems and excessive weight gains in the past two years.


Change in antikaliuretic response to potassium-sparing diuretics in patients with cirrhotic ascites.

In 2 elderly patients with ascites due to hepatic cirrhosis, potassium excretion decreased during re-administration of potassium-sparing diuretics after recurrence of ascites following withdrawal of previous prolonged treatment. An exaggerated antikaliuretic response and a paradoxic rise in potassium excretion are "unpredictable" changes which may occur during administration of potassium-sparing diuretics at different times in the same patient treated with the same drug.


Pharmacokinetic approach to drug dosing in the aged.

Data in the literature show that there is a constant ratio of total body fluid to lean cell mass with increasing age (1.15 for males and 1.31 for females). Since the drug receptors usually are found in the tissues, and since cell mass and total body fluid apparently decrease at a constant rate, it would seem that the volume of distribution of drugs decreases proportionally with increasing age. Kidney function, as measured by the glomerular filtration rate and transport maximum, apparently decreases with increasing age according to zero-order kinetics. Based on these data, correction factors were established for the change in volume of distribution and renal functions with increasing age. Equations were derived for calculating the loading dose and maintenance dosage of drugs in multiple-dose therapy in females and males. Equations are presented for drugs following the minimal inhibitory concentration (MIC) pattern and the log dose-response pattern, respectively. The MIC pattern is recommended in the use of bacteriostatic drugs, for which it is essential to maintain recommended in the use of bacteriostatic drugs, for which it is essential to maintain during the entire course of therapy a minimum inhibitory concentration. The log dose-response pattern is recommended for bactericidal and antiarrhythmia drugs, for which it is essential to obtain an average therapeutic steady-state concentration. Based on this pharmacokinetic approach, it would seem that elderly patients, during multiple-dose therapy, are exposed to dose sizes that are too large if no correction is made.


A mobile, mental-hospital-based team for geropsychiatric service in the community.

At Norristown State Hospital a mobile Team of workers was organized to give personalized and preventive psychiatric, medical and social attention to distressed elderly people within the communities served by this large psychiatric institution. The Team's mobility permitted flexible approaches to problem-solving at the person's own home or other places of residence. Over its 8.5 years of existence the Team evaluated 1,438 elderly persons and acted in a consultant capacity to 77 nursing or retirement homes. Most of these clients were treated successfully within the community; only 222 required admission to the parent hospital during that time. Those treated in their own homes usually were able to maintain or improve the quality of their lives. The timely psychiatric, medical and social help often uncovered physical and social factors that previously had been overlooked.


Importance of aortic dilatation in the genesis of the innocent systolic ejection murmur of the aged.

Aortic systolic murmurs and aortic dilatation were studied in a randomized sample of 100 hospital patients over the age of 60. Clinical, phonocardiographic, radiologic and carotid-pulse data provided the basis for graphic characterization of the murmurs. Senile aortic dilatation was common (66 patients). In a high percentage (39 patients), dilatation of the ascending aorta (and sometimes of the arch) was associated with an aortic systolic murmur. The "innocent" type was always associated with aortic dilatation. This "innocent murmur of the aged", even though caused by structural alterations, should be considered in the same light as the "innocent murmur of children", as it is not associated with dynamic embarrassment of the circulation.


Colonoscopy in the management of diseases of the colon and rectum.

This report covers a 2.5-year experience with colonoscopy in the management of 208 patients (104 men and 98 women, average age 58 years). Colonic bleeding of unknown cause and abnormal barium-enema findings were the most common indications for colonoscopic examination. During this period, 110 colonoscopic polypectomies were performed. Among the few complications was one case of perforation of the sigmoid from transcolonoscopic removal of a small carcinoma; the perforation was incidentally discovered at the time of subsequent laparotomy. Bleeding occurred in 6 patients, but only one of them required surgical intervention to arrest the hemorrhage. Colonoscopy is a safe, effective and reliable diagnostic and therapeutic procedure. Its use can reduce expense for the patient and obviate a long painful postoperative period.


Analysis of geriatric surgical experience in a veterans home.

Surgical experience at the hospital of a State Veterans Home is reviewed over a period of two and half years (1973-1975). The average age of the patients was 74 years, and many had severe pulmonary or cardiac disease. Of the operations performed, 283 were major and 301 were minor. For the major operations (including emergencies) the mortality rate was 4.2 percent, for the minor procedures the rate was zero, and for all types of procedures the overall mortality rate was 2 percent. Emergency operations increased the expected mortality tenfold. Colonic and biliary-tract operations bore the highest mortality. The incidence of malignant lesions was high. In the elderly, indicated surgical procedures are justified, provided they are carried out by an organized, highly trained health team.


Isozymes in androgenetic and gynogenetic white amur, gynogenetic carp, and carp-amur hybrids.

Gynogentic and androgenetic progeny appeared in crosses between white amur, Ctenopharyngodon idella, and carp, Cyprinus carpio. Hemoglobin, plasma general proteins, and plasma isoenzymes were studied by electrophoresis to determine inheritance patterns. Electrophoretic bands indicated that gynogenetic white amur had no paternal inheritance from carp and that adrogenetic white amur also were pure white amur. Gynogeneiss in carp was confirmed by the absence of paternal inheritance. Hemoglobins, general proteins, and esterases distinguished the two species. Within a species there were no differences in proteins between gynogenetic, adrogenetic and normal fish. Lactate dehydrogenase (LDH) differed between carp and white amur and was a good marker for detecting heterologous inheritance in adrogenesis or gynogenesis because expression of LDH alleles from white amur was inhibited by the carp genome. Alkaline phosphatase and malate dehydrogenase had similar electrophoretic mobility in the two species.


Genetics of red body polymorphism in the isopod, Venezillo evergladensis.

A red body morph with reddish-orange body and brownish-red eyes is described in the terrestrial isopod, Venezillo evergladensis. The alternate, non-red morph, has a brown body and black eyes and either gray or orange antennae. Breeding results show three alleles, rg, ro and r at an autosomal locus control the variation. The dominance hierarchy is rg less than ro less that r; the genotypes, rg/rg, rg/ro, and rg/r are non-red, grey, ro/ro and ro/r are non-red, orange, and r/r are red. The gray antennae of non-red, gray individuals is variable in expression although still objectively recognized. The red body morph and its inheritance is paralleled in related species, while the antennal variation identifies a new allele. Sperm storage, exceeding a full year, and multiple matings in nature are documented.


Victims of a rabid wolf in india: effect of severity and location of bites on development of rabies.

A rabid wolf attacked 12 humans and six animals in six villages in the course of a day before it was surrounded and killed. Of the 12 human victims, three had severe wounds to the face and head, five had severe lacerations, two had less severe wounds on the trunk and limbs, and two had minor wounds or scratches. Nine of these victims received antirabies treatment with Semple vaccine (preceded by immune serum in one case). No persons with trunk and limb bites died. All three patients with head wounds died. One of these patients received vaccine and serum, one received vaccine, and the third had no treatment. Neutralizing antibodies were demonstrated in blood samples drawn 58 days after the incident from five survivors who had received a full course of treatment, but such antibodies were absent from the blood of one untreated survivor (who had only minor scratches and had refused treatment) and of the wife of one man who died, who had been in close contact with her husband throughout his illness. All severely bitten animals died of rabies. A dog that the carcass of a pig which had died of rabies itself developed rabies 12 days later. This event raised the possibility of infection by the oral route.


Joint effects of mutation and selection on gametic frequencies in a panmictic population.

The classical theory of population genetics considers the situation when mutation rates are small relative to selection coefficients, and when selection acts only in previously mutated gametes and there is no back mutation. I have considered the effects of mutation and selection when the newly mutated gametes as well as the preexisting one are affected by selection. If the mutation rate m from A leads to a is greater than or equal to the selection coefficient, s, against a, the equilibrium frequency of A is zero. If m less than s, the equilibrium probability of A is m(1 - s)/s(1 - m). It is suggested that the solutions obtained here may be realistic in certain situations, particularly whey mutation is considered at the molecular level.


Myodystrophy, a new myopathy on chromosome 8 of the mouse.

A new recessive mutation, myd, causing a diffuse and progressive myopathy in the mouse is described. Histopathological comparisons with normal littermates showed widely distributed focal lesions in all skeletal muscles of myd/myd. Body and organ weights of affected mice were considerably less than those of normal littermates and the mean lifespan of myodystrophic mice that survived weaning was 17 weeks with a range of 5 to 39 weeks. Myodystrophy is located on chromosome 8; it is linked to Os with about 6 percent and to Eso with about 37 percent recombination.


Host immune responses after administration of inactivated Venezuelan equine encephalomyelitis virus vaccines. I. Description and characterization of adoptive transfer by immune spleen cells.

Cellular immune responses after immunization with a number of inactivated Venezuelan equine encephalomyelitis (VEE) virus vaccines were evaluated in mice by means of an adoptive transfer system. Formalin-inactivated, TC-83 strain VEE virus vaccine was immunogenic and highly effective in protecting recipient mice against challenge with virulent VEE virus. In contrast to immunization with live TC-83 VEE virus vaccine, however, immunization with inactivated VEE vaccine did not provide donor mice with the capacity to transfer adoptive immunity readily. Only when mice were immunized with inactivated VEE vaccine combined with specific adjuvants (particularly complete Freund's adjuvant or Bordetella pertussis) were donors capable of consistently transferring adoptive immunity. The total dose of inactivated VEE vaccine did not appear to influence the capacity to transfer adoptive immunity. On the other hand, weekly boosters of VEE vaccine and/or administration of vaccine with specific adjuvants did markedly influence donor immune responses.


Visible mutation induction in Mormoniella by low frequency ultrasonic energy.

Low frequency ultrasonic energy was utilized in an attempt to induce visible mutations in the parasitoid wasp Mormoniella vitripennis (Walker). Ultrasonic exposure at a frequency of 20,000 cycles per second was accomplished in aqueous medium with a commercially obtained energy source. Among the 22,396 progeny of exposed males and females, 63 phenotypically changed wasps were recovered. Three of these changes from exposed males and two from exposed females proved to be genetically transmissible. No transmissible changes were found among 4,739 control progeny. This study demonstrates that low frequency ultrasound may be used as an effective mutagenic agent with this organism, and suggests that it may have applications with other genetic systems.


Chemical and biological characterization of the lipopolysaccharide of Bacteroides fragilis subspecies fragilis.

Bacterial lipopolysaccharides extracted from Bacteroides fragilis subspecies fragilis lacked 2-keto-3-deoxyoctonate and heptose, sugars which make up part of the inner core of most bacterial endotoxins. Over 98% of the lipid portion of this material could be removed easily with chloroform-methanol and alcohol, a finding which indicates a loose association between the polysaccharide and lipid moieties. The lipopolysaccharides caused gelation of limulus lysate at a concentration significantly higher than that for the endotoxin of Salmonella typhi. None of the extracts was lethal in 10-day-old chick embryos at doses of greater than 200 mug per egg, whereas the endotoxin of Neisseria meningitidis was lethal at a dose of 1.2 mug per egg. The local Shwartzman reaction could not be induced by levels of B. fragilis endotoxin of up to 1,000 mug per rabbit, whereas a (control) endotoxin of S. typhi induced this phenomenon at a level of 3 mug per rabbit. Intact oxygen-killed B. fragilis failed to provoke the local Shwartzman reaction at doses of 2,500 mug. These results indicate that B. fragilis has a lipopolysaccharide different from that of most gram-negative bacteria. Although it retains some of the chemical and biologic properties of classical endotoxin, it seems to lack others. This observation may have significant clinical implications.


Chromosomes, hemoglobins, and transferrins of Iranian domestic sheep.

Twelve breeds of Iranian domestic sheep were cytogenetically analyzed. The diploid chromosome number of 2n = 54 is identical to that of most breeds of domestic sheep, which is comprised of 3 pairs of metacentric and 23 pairs of acrocentric autosomes. The sex chromosomes consist of a large acrocentric X and a small bi-armed Y. Hemoglobin analysis by isoelectric focusing for these 12 breeds resulted in the identification of 2 protein fractions: Hb AB and B. The A allele was observed in 7 percent of the 506 sheep sampled, in 6 of the 12 breeds, and then only in the heterozygous form. Transferrins were analyzed by starch-gel electrophoresis and comparisons made between breeds. Nine alleles, pooled frequency of occurrence in descending order, B, C, D, A, M, E, G, P, and I were identified and resulted in 19 phenotypes. Tfs A, B, C, and D were observed in all breeds, whereas I was found in 2,G in 1, M in 8, E in 6, and P in 2. Significant differences in allelic occurrence of Tfs A, B, C, and D were observed in seven breeds.


Pharmacokinetic model for serum concentrations of ampicillin in the newborn infant.

The time course of ampicillin concentrations in the sera of three newborn infants during and upon termination of intravenous infusion at a constant rate can be described by a two-compartment pharmacokinetic model. The parameters of the model were determined by simultaneously fitting the serum concentration data obtained during and after the infusion by means of a nonlinear regression program with the aid of a digital computer. The half-life of ampicillin in the infants ranged from 2.1 to 2.9 hr; these values are more than twice those observed in adults with normal renal function.


Dane particle-associated DNA polymerase and e antigen: relation to chronic hepatitis among carriers of hepatitis B surface antigen.

Thirty-nine carriers of hepatitis B surface antigen (HBs Ag) were studied with respect to e antigen and Dane particle-associated DNA polymerase activity and their relation to chronic hepatitis. Most of these individuals were followed for four or five years. A strong correlation between e antigen and DNA polymerase activity was found. Of the 22 e antigen-positive patients, 21 showed polymerase activity; none of the 13 e antigen-negative patients (one of whom had antibody to e antigen) had such activity. Three of four patients who became e antigen-negative after being e antigen-positive showed loss of polymerase activity. An independent clinical evaluation showed a strong correlation between chronic hepatitis and positive reactions in the tests for e antigen and DNA polymerase. The results emphasize the possibility of differentiating between groups of chronic carriers of HBs Ag by testing for e antigen and Dane particle-associated DNA polymerase activity. The differentiation may have important clinical implications.


Effects of lidocaine, phenytoin and quinidine on the ischemic canine myocardium.

The effects of therapeutic concentrations of lidocaine, quinidine and phenytoin on the electrograms and excitability of ischemic canine myocardium were investigated. The threshold stimulation current was determined as the minimum current necessary to drive the ventricles at 300 msec intervals. Administration of the drugs did not change the threshold stimulation current of the control myocardium, but lidocaine (P less than 0.002), quinidine (P less than 0.01) and phenytoin (P less than 0.05) all markedly increased the threshold stimulation current of the ischemic tissue. The effects on the electrograms were small but consistent with current electrophysiological knowledge. This selective depression of the electrical activity of the ischemic tissue may form an important mechanism of action of these antiarrhythmic agents. However, this same effect may under certain conditions precipitate serious arrhythmias.


Electrocardiographic changes in precordial leads during selective coronary angiography.

Precordial electrocardiographic leads V1, V2, V5, V6, and limb leads I and II were recorded simultaneously utilizing radio transparent electrodes and wire leads during coronary angiography in 35 patients with obstructive coronary disease and in 17 subjects with normal coronary angiograms. The pattern of electrocardiographic changes produced by injection of contrast material into either the right or left coronary artery was similar in both groups of patients. During injections into the left coronary artery a leftward shift of the QRS occurred. Injections into the right coronary artery also produced a leftward shift of depolarization forces but, in addition, the QRS became inferiorly directed more consistently than during left coronary injections. The changes produced by angiography in the pattern of repolarization consisted of a marked increase in T wave amplitude and the transient appearance of large U waves. The changes in T waves were consistently opposite in direction to those of the QRS. The polarity of the U wave coincided with that of the T wave in the majority of cases. No consistent differences in the pattern of electrocardiographic changes were observed in subjects with a dominant right coronary artery from those with a dominant left system nor in subjects with normal coronaries from those with occlusive coronary disease.


Correlation of polarcardiographic criteria for myocardial infarction with arteriographic and ventriculographic findings (substantiation of transmural and presentation of non-transmural criteria).

Sensitivity and specificity of polarcardiographic criteria for myocardial infarction were compared with those of electrocardiographic criteria in 108 patients with chest pain syndromes who were referred for coronary arteriography and left ventriculography. With the combination of total occlusion of at least one coronary artery and abnormal systolic contraction of at least part of the left ventricle as the best available documentation of myocardial disease, sensitivity and specificity were 70% and 67%, respectively, using electrocardiographic criteria and 80% and 73% using polarcardiographic criteria, for both anterior and inferior myocardial infarction. Another polarcardiographic criterion--rightward shift in R latitude at 10 msec after onset of QRS--occurred concurrently with vessel occulusion in 16 of 17 patients (94%), in four of whom this was the only objective evidence of myocardial infarction, and three of whom there was no manifest abnormality of wall contraction. This criterion is considered evidence of non-transmural myocardial infarction, probably in the subendocardial layer near the apex of the left ventricle. When such evidence is added, sensitivity of polarcardiographic criteria increased to 84%, and specificity decreased to equal that of the electrocardiographic criteria (67%).


Case studies: Chronic accelerated ventricular rhythm.

Two patients are presented with accelerated ventricular rhythms of unusually long duration. The clinical and electrophysiological aspects of this problem are discussed.


"Torsade de pointes" initiated by electrical ventricular stimulation.

Four cases are described in which electrical stimulation of the right ventricle produced the ventricular arrhythmia known as "torsade de pointes". This arrhythmia has previously been described as classically occurring in the context of the chronic bradycardias, particularly when there is also hypokalemia and a long QT interval, being most frequently initiated by a ventricular extrasystole occurring relatively late during ventricular repolarization. One patient had suffered a recent anterior myocardial infarction and developed the arrhythmia during rapid pacing for atrial flutter, when the electrode catheter had inadvertently entered the right ventricle. In the other three patients the arrhythmia was produced during the ventricular extrastimulus test performed during routine diagnostic electrophysiological investigation.


Recurrent tachycardias due to an accessory pathway.

A 48 year old female presented with a long history of palpitations and syncopal episodes. His bundle electrogram studies were performed in order to evaluate the conduction system. The electrocardiogram (ECG) revealed normal PR and QRS intervals, while the unpaced His electrogram was normal. With atrial pacing rates of 110 to 180 beats/min, the AH and HV intervals remained essentially unchanged. This signifies that there was an accessory conduction pathway which bypassed the AV node. Thus, pre-excitation can not be eliminated as a diagnostic possibility even if the ECG is normal.


Ventricular reciprocal rhythm occurring in succession in a patient with a variant angina pectoris.

A clinical surface electrocardiogram (ECG) in which ventricular reciprocal rhythm occurred occasionally three times and probably seven times in succession together with paroxysmal ventricular tachycardia and ventricular extrasystoles in competition with sinus rhythm causing incomplete A-V dissociation is described. An ECG tracing of ventricular reciprocal rhythm occurring in succession has never been reported previously as far as can be ascertained from published reports.


Clinical efficacy of a truncated exponential decay defibrillator.

Trans-chest electrical ventricular defibrillation was attempted in eight adult patients using a 400 watt-second truncated exponential decay waveform defibrillator. All attempts occurred in the immediate post-operative period after heart surgery. Five of the eight subjects were defibrillated (63% success). This success rate is similar to that of 300 watt-second damped sinusoidal waveform defibrillators.


[Reversibility of the morphological and functional dedifferentiation occurring in cultures of avian embryonic liver cells (author's transl)].

Primary cell cultures are established from 8-day quail embryo livers. During the first three days the culture is made up of areas of epithelial-like cells and scattered fibroblasts. The cytoplasm of the epithelial cells shows a high glycogen content as detected by the PAS reaction controlled with salivary amylase digestion. During the following days an important increase in the number of fibroblastic cells is observed. After 6-7 days of cultivation, the epithelial cells have disappeared and the culture is entirely fibroblastic. PAS technique does not show any trace of glycogen in these cultures which have been prolonged up to 45 days. Six-to 45-day primary cultures entirely made up of fibroblasts were associated with hepatic or pulmonary mesenchyme in organotypic culture for 3-4 days. In some cases the explant was first cultivated in vitro for 2 days and then grafted into a 5-day-old chick embryo on the chorioallantoic membrane for 6 days. In the secondary cultures hepatocytes showing an epithelial arrangement and a high glycogen content were observed. It appears from this observation that some of the primary culture fibroblasts are in fact dedifferentiated parenchymal cells. Such a dedifferentiation is a reversible phenomenon since the cells retain the ability to express their initial determination if they are placed in convenient environmental conditions. The role of the specific tissular arrangement in the stability of the differentiated state is discussed.


A descriptive study of the rate of elongation and differentiation of the skeleton of the developing chick wing.

Differentiation of the wing skeleton is clearly visible in whole mounts from stage 24. It proceeds in proximo-distal and postero-anterior sequence. It is possible to map the part of the limb giving rise to each skeletal element as it appears and subsequently. This enables one to estimate: (a) a rate of elongation curve for each segment level, (b) the intrinsic rate of change of elongation of the cartilage, (c) a definitive extrapolation back to classical presumptive fate maps, (d) the normal range of variation in the proportion of the limb occupied by the three main segmental levels (stylopod, autopod, zeugopod).


Adult haemoglobin in developmentally retarded tadpoles of Xenopus laevis.

Tadpoles of Xenopus laevis reared in water containing 0-01% propylthiouracil continue to grow but fail to develop or metamorphose. The haemoglobin of such tadpoles has been extracted in buffer, converted to a cyanmet form, and run on polyacrylamide gels. The developmentally retarded tadpoles are found to possess adult-type haemoglobin rather than the tadpole type which normally characterizes their developmental stage.


Leg regeneration in the cockroach, Blatella germanica. II. Regeneration from a non-congruent tibial graft/host junction.

The interactions occurring between host and graft leg epidermis at a non-congruent junction were studied in the cockroach, Blatella germanica. Graft and host tibia were cut perpendicular to the proximal-distal axis and two heteropleural combinations were used to reverse separately the two transverse axes of the graft relative to the host. Use of dark and light cuticle colour mutants gave a good indication of the graft or host origin of regenerated structures. Graft/host junctions regenerated segmented structures in various spatial arrangements, always comprising two copies of all structures distal to the level of the junction. It is concluded that the categories--two separate laterals, double lateral, completely and partially autonomous regeneration--reflect two processes. (i) If the graft tarsus is removed, graft and host may not heal together and interact, but form autonomous regenerates lying in mirror-image symmetry separating original graft and host levels. (ii) If interaction occurs between graft and host (or their developing autonomous regenerates) two laterals of dual origin are produced, one from each point of transverse axis incongruity. These laterals may secondarily fuse together to form a double structure originating from a point of congruity. The orientation and composition of the component tarsi of the double structure depend on the site of origin and the extent to which the two laterals fuse. It is argued that the four 'faces' and two 'transverse axes' of the leg are merely descriptive terms. A new model is developed whereby lateral regeneration arises directly from the circumferential organisation of the leg epidermis. Previous work has shown that position is specified continuously around the circumference, and that intercalary regeneration occurs by the shortest route between confronted positions. After reversal of one 'transverse axis' the shortest route between confronted graft and host positions is different on the two sides of each of the two points of 'axis' incongruity, and at these points the two halves of a complete circumference are formed. These lateral circumferences, like the terminal circumference exposed by amputation, cannot heal over by intercalary regeneration, and this leads to regeneration of distal structures. The model accounts for lateral regeneration after reversal of both 'transverse axes' by 180 degrees rotation of a homopleural graft. The possibility is discussed that there may be clonal restrictions on the circumferential positions which the progeny of a cell may occupy.


[Adult leg development of Tenebrio molitor: I. Experimental analysis of the restoration process during morphogenesis (author's transl)].

The leg of the last instar larva, and especially the pharate pupa, of Tenebrio molitor (Coleoptera) shows considerable restoration ability. Restoration refers to the regeneration of leg structures removed during the last larval instar. This process involves only those tissues adjacent to the cut surface. At each level of the leg, amputation before a characteristic time leads to the restoration of a complete leg, but thereafter the new segments formed are hypomorphic or just lobes. After an amputation close to the pupal ecdysis, fragments are obtained, and these incomplete structures show that the restoration process has ceased. Just before the pupal ecdysis the leg is withdrawn from the cuticle, so a very late amputation does not effect the leg tissue and a complete pupal and adult leg is formed. The whole of the larval leg participates in adult leg morphogenesis, and histological techniques demonstrate a great correspondence between larval and adult leg segments. The larval trochanter, however, forms the adult trochanter and the proximal part of the femur. The larval tibia forms the adult tibia plus tarsus, except for the adult claws which develop from the larval tarsal claw.


Cell specific events occurring during development.

Ultra-microfluorometric techniques were adapted to follow the time sequence of glycogen degradation during the differentiation of two cell types in Dictyostelium discoideum. Glycogen content, glycogen phosphorylase activity, and inorganic phosphate accumulation were localized in specific cell types during stalk and spore development. Glycogen levels in pre-stalk cells remained constant during the pseudoplasmodium and early culmination stages of development. However, as pre-stalk cells migrated into the position of stalk formation, a cell specific degradation of glycogen was observed. The loss of glycogen from pre-stalk cells was accompanied by an increase in the activity of glycogen phosphorylase. This increase in activity from 0-04 to 0-14 moles/h/kg dry wt. occurred as pre-stalk cells entered the position of stalk formation. An inverse relationship was found between glycogen levels and inorganic phosphate (Pi) levels in the developing stalk. During the process of stalk construction, a gradient of Pi levels occurred from the apex to the base of the developing stalk. Glycogen degradation from pre-spore cells lagged behind that of pre-stalk cells. No change in pre-spore cell glycogen levels was observed until stalk construction was nearly completed. The results emphasize the importance of the physical position of a cell with respect to its composition and fate during development.


Regeneration of amputated limb-buds in early rat embryos.

Rat embryos, dissected from the uterus at 11 1/2 days' gestation, have been used to study the regenerative powers of the embryonic limb. One forelimb-bud of each embryo was amputated, via an incision in the membranes. Embryos were subsequently grown in roller-bottle cultures for 44 h, then examined histologically. Twenty-nine out of 32 healthy embryos had formed limb-bud regenerates, 14 of which were of normal size and shape. Eight of them had a normal apical ectodermal ridge. It is concluded that at this stage of development there is sufficient versatility in the embryonic cells for a limb rudiment to be replaced by adjacent mesenchyme and epidermal cells. The implications of this finding are discussed in connexion with previous studies on the regeneration of appendages in vertebrate embryos.


Effect of dorsal and ventral limb ectoderm on the development of the limb of the embryonic chick.

Limb ectoderm plus a small amount of subjacent mesoderm obtained from the dorsal or the ventral surface of each of the four limbs of the chick embryo were grafted to the dorsal surface of the right wing in either reversed or normal orientation. The host wings developed in abnormal humerus in all cases except when the graft was obtained from the dorsal surface of the right wing and was in normal orientation. However, the nature of the abnormalities varied with the source of the graft and with the orientation of the graft. It is unlikely that the abnormalities were related solely to the small amount of mesoderm grafted since previous experiments have demonstrated that the mesoderm would regulate. Flank ectoderm plus a small amount of flank mesoderm did not cause limb abnormalities when grafted in the same manner.


The development of the notochord in the chick embryo, studied by scanning and transmission electron microscopy.

The notochord of the chick embryo between stages 5 and 23 inclusive has been studied by scanning electron microscopy, supplemented by transmission electron microscopy. Three main phases of development are described, and these have been designated: bilaminar; rod-like, unvacuolated; rod-like and vacuolated. The changes in shape of the organ from bilaminar to rod-like is accompanied by changes in the shape, orientation and position of the cells, an increase in the complexity of the cell contacts, and the laying down of a basal lamina. The change from the unvacuolated to the vacuolated phase is accompanied by increasing complexity within the cytoplasm. Most of the vacuoles are intracellular and appear empty though some contain a granular material. The notochordal sheath appears to be secreted by the notochordal cells and fine fibrillar material has been seen in the intercellular spaces. By stage 23, most of the notochordal cells have become so highly vacuolated that the cytoplasm has become closely packed around the nucleus.


[Gene activity during embryogenesis of the earthworm Eisenia foetida ((3H)uracil autoradiography and actinomycin D treatment) (author's transl)].

Embryos of Eisenia foetida (Spiralia) have been cultivated with [3H]uracil precursor of RNA at different stages of development from egg to gastrula. The results show that ribonucleic acid synthesis detected by autoradiography begins precociously. During segmentation messenger RNAs are produced by interphase nuclei and liberated in cytoplasm cyclically at mitosis. After the blastula stage rRNAs (nucleoli), which can migrate through the nuclear membranes, predominate. The blastomeres, which contain polar plasm and also mesoderm, already known for its controlling part in embryogenesis after gastrulation, are the seats of the increasingly important ribonucleic acid synthesis. These genetic transcriptions, which are inhibited by actinomycin D, are implicated in the determination of the blastomers and postblastular differentiation. Only the messages required for the segmentation divisions pre-exist in the undivided egg.


Long-term retention of the habituation of lick suppression and startle response produced by a single auditory stimulus.

Response decrement produced by a single, 2-sec, 98 dB, auditory stimulus in rats was retained without detectable loss for intervals ranging from approximately 30 sec to 30 days. Response decrements produced by stimulation over these intervals reached an apparent asymptote after 2 or 3 stimulus presentations. These response decrements were unambiguously associated with stimulus presentation for the lick suppression measure, but nonspecific decremental effects may have contributed to the startle response decrements. After these long-term decrements had reached asymptote, 300 stimulus presentations with 1-sec interstimulus intervals produced further response decrements, but these decrements recovered completely within 24 hr., responsiveness returning to the previously established long-term asymptote. The data show that unreinforced stimulus presentations can produce both relatively permanent response decrements and apparently independent short-term decrements. The data also suggest that long-term retention may be more generally characteristic of habituation than is usually assumed.


Interaction versus independence of startle-modification processes in the rat.

In a series of experiments it was found that the amount of inhibition produced by a weak acoustic stimulus occurring 64 msec prior to a startle-eliciting stimulus is unaffected by a second weak acoustic stimulus occurring 4 msec prior to the startle-eliciting stimulus. Likewise, the amount of latency reduction produced by an antecedent stimulus with a 4-msec lead time is unaffected by the presence of an antecedent stimulus with a 64-msec lead time. Finally, it was found that both the amount of inhibition produced by a prestimulus with a 64-msec lead time and the amount of latency reduction produced by a prestimulus with a 4-msec lead time are independent of the intensity of the startle-eliciting stimulus. These findings suggest that the inhibition effect is independent of the latency reduction effect and that both are independent of the absolute level of activation in the neural mechanisms responsible for the overt startle response.


Modification of ducklings' filial behavior by aversive stimulation.

Three experiments examined the effects of aversive stimulation in the context of imprinting. In Experiment 1, newly hatched ducklings were electrically shocked in either the presence or absence of an imprinting stimulus, and both their tendency to follow the stimulus when it was presented alone and their preference for it over novel stimuli were subsequently assessed. The results indicated that the shock enhanced the subjects' tendency to follow the imprinting stimulus in the nonchoice situation regardless of whether the ducklings were shocked in its presence or absence. If, however, the electrical shocks were associated with the presence of the imprinting stimulus, they also reversed the ducklings' usual preference for the imprinting object over the novel stimuli. Comparable effects were obtained in the second experiment in which 5-day-old ducklings were electrically shocked in either the presence or absence of a novel, fear-eliciting imprinting stimulus. In Experiment 3, electrical shock was administered to newly hatched ducklings independently of their exposure to an imprinting stimulus, and it was found that, relative to older ducklings that received the same treatment, the newly hatched subjects subsequently displayed less emotionally in fear-eliciting situations. The results were interpreted as suggesting that there are at least three distinct effects of aversive stimulation in the context of imprinting-motivational, associative, and developmental.


How x-rays inhibit amphibian limb regeneration.

The effects of an inhibiting dose of 2,000 rad of X-rays on the regenerating limbs of axolotl larvae have been examined in a histological and cytological study. Particular attention was paid to the mitotic indices of normal and irradiated epidermal and blastemal cells. Both the characteristic pattern of epidermal mitotic stimulation which normally follows amputation and the later increase in blastemal mitoses are suppressed by irradiation. In most cells the effects are permanent, but in a small proportion a mitotic delay is induced and upon subsequent division chromosome damage in the form of micronuclei is revealed. Thus irradiated cells which do divide almost certainly die. These results are discussed in relation to other theories of X-ray inhibition of regeneration with particular reference to the view that irradiated cells can be reactivated.


Sperm proteinase release during fertilization of rabbit ova.

Proteinase activity was found to be present along the sides of sperm penetration tunnels through the zonae pellucidae of rabbit ova using silver-proteinate staining techniques. This is the first direct confirmation of the generally accepted concept of sperm penetration by proteinase release and digestion of the zona pellucida.


Fertilization acid of sea urchin eggs is not a consequence of cortical granule exocytosis.

Sea urchin eggs treated with 10 mM NHC1 release a "fertilization acid" although cortical granule exocytosis does not take place. If the eggs are inseminated following ammonia activation, the cortical reaction occurs and a fertilization membrane elevates in the absence of detectable acid release. Examination by electron microscopy of eggs fixed between ammonia activation and insemination confirms the presence of intact granules. Thus, the fertilization acid is not caused by the release of the cortical granules. Ammonia treatment of fertilized eggs stimulates further release of acid. The release of acid can occur repeatedly in ammonia activated eggs if they are washed into normal seawater between successive ammonia treatments. Our results suggest that the release of fertilization acid is related to some metabolic process which can be turned "on or off".


Mouse sperm genotype and the rate of egg penetration in vitro.

(C57BL/10 X CBA)F1 mouse eggs were incubated in vitro with either F1 or outbred TO sperm for 15 minutes-6 hours. Upon removal from the sperm suspensions some eggs were treated with pronase to remove zonae and then cultured, while the remainder were simply cultured to allow a comparison of the fertilization rates in the two groups. Although a brief incubation was sufficient for a high rate of fertilization when the zonae remained intact, results from the zona-free eggs indicated that penetration, i.e., sperm fusion with the vitellus, had not been achieved in all eggs during the shorter incubations. Results from the latter groups of eggs indicated that a 1 hour incubation with TO sperm and a 2 hour incubation with F1 sperm were needed to obtain a mean fertilization rate of 50%. Fertilization was complete within 1.5 hours using TO sperm and 2.5 hours using F1 sperm, thus indicating that under similar environmental conditions sperm genotype can significantly affect the rate of penetration.


In vitro utilization of exogenous procollagen by embryonic tooth germs.

Embryonic mouse tooth germs treated with L-azetidine-2-carboxylic acid cease their development, undergo a regression of the enamel organ, and do not maintain the histological characteristics of the explanted dental organ. On the other hand if procollagen is added exogenously to explants continously treated with L-azetidine, the effects of the inhibitor are not seen and the tissue is maintained. Thus, exogenously supplied procollagen supports morphogenesis in tooth rudiments that are unable to synthesize procollagen.


Na is essential for activation of the inseminated sea urchin egg.

The presence of at least 2.5 mM Na during the first several min after insemination is required for the activation of sea urchin eggs. Of those chemical species examined that exist entirely as cations, and which did not activate the unfertilized egg, only Li substitutes for Na. Ammonium and other amines, with pKa values between 9 and 10.8, in the complete absence of Na (a) can induce nuclear activation of unfertilized eggs, and (b) permit the development of the early fertilized egg through the stage that normally requires Na.


Scanning electron microscope studies of sea urchin fertilization. I. Eggs with vitelline layers.

The surface coats of sea urchin eggs and the events of fertilization which take place on these surfaces were examined with the scanning electron microscope (SEM). Gametes of Stronglyocentrotus purpuratus and Lytechinus pictus were considered in detail; eggs of seven other echinoids were examined for comparative purposes. Jelly coats, preserved by varying the pH of fixation, were found to vary in morphology and solubility properties between species. The vitelline layers of the nine echinoids are characterized by arrays of projections which are impressions of cytoplasmic microvilli in the vitelline layer. After sperm bind to the egg surface via the acrosomal process, fine filaments, apparently an egg response to insemination, further connect some sperm heads and tails to the egg. The cortical reactions spread out as a wave from where the fertilizing sperm fused with the egg; separation of the vitelline layer proceeds as a smooth wave from S. purpuratus eggs and as a series of localized separations in L. pictus eggs. The fertilization membranes of S. purpuratus and Allocentrotus fragilis zygotes are expanded replicas of their respective vitelline layers, suggesting that fertilization membranes are formed by an unfolding of the vitelline layer.


Regional differences between nuclear concentration of (3H) estradiol and (3H) progesterone and their action on the uterus of rat during delayed implantation.

The cellular and subcellular localization of radioactivity by dry-mount autoradiography was studied at 5, 15 and 30 minutes after intraluminal or at 5, 15, and 60 minutes after subcutaneous administration of (3H) estradiol or (3H) progesterone to rats in which implantation was delayed by ovariectomy on day 3 post-coitum, followed by treatment with progesterone. After intraluminal instillation of (3H) estradiol or (3H) progesterone, radioactivity was cleared from the uterine lumen at 5 minutes. After intraluminal as well as subcutaneous injection of (3H) estradiol, radioactivity was concentrated at all time intervals in the nuclei of cells of the substantia propria, glands and muscularis, but not in the luminal epithelium. White blood cells and endothelial cells were unlabeled, while perivascular cells showed concentration of radioactivity. After intraluminal instillation of (3H) progesterone, radioactivity was retained in the cytoplasm of the luminal epithelium at 5 and 15 minutes, while no such concentration appeared after subcutaneous injection. No selective nuclear retention was observed in the luminal epithelium, in contrast to the substantia propria and muscularis. The autoradiographic results indicate that progesterone treatment simulating the conditions of early pregnancy, changes the uptake affinity of uterine tissues for (3H) estradiol. The lack of a detectable concentration of estrogen within nuclei of the luminal epithelium does not preclude hormone action. Possible mechanisms of metabolic activation of the uterine luminal epithelium in the apparent absence of concentration of (3H) estradiol to nuclei of the luminal epithelium are discussed.


Effects of seasonal and social factors on testicular activity and hormone levels in domestic pigeons.

Testicular morphology and plasma concentrations of luteinizing hormone (LH), testosterone, progesterone, and estradiol-17beta were compared in paired (n = 8) and unpaired (n = 7) racing pigeons killed in December. The birds were housed mixed together under natural lighting conditions in two unheated lofts which contained no nesting facilities, in Kiel (54 degrees N), Germany. The paired birds had been paired for at least two months. Testicular weights and diameters of tubules were significantly higher (p less than 0.05) in paired (1.64 +/- 0.25 gm; 218 +/- 12 mum) than in unpaired birds (0.79 +/- 0.25 gm; 165 +/- 20 mum). The testes of paired birds were spermatogenetically more active than those of unpaired birds. Plasma concentrations of some hormones concerned with reproduction were, in paired and unpaired birds respectively: LH, 2.28 +/- 0.43 ng/ml and 0.98 +/- 0.36 ng/ml (significantly different, p less than 0.1); testosterone, 1.24 +/- 0.51 ng/ml and 0.59 +/- 0.12 ng/ml (not significantly different); progesterone, 0.58 +/- 0.08 ng/ml and 0.90 +/- 0.12 ng/ml (sifnificantly different, p less than 0.05); and estradiol-17beta, 16.3 +/- 0.95 pg/ml and 18.7 +/- 2.25 pg/ml (not significantly different). Thus, the stimulatory effects of a mate on gonadotropin secretion and gonadal activity which have often been reported for female ring doves and domestic pigeons are also demonstrable in males during the late fall. Seasonal testicular regression in the unpaired males at this time of year was not prevented by the presence of paired females.


The effect of metabolites of testosterone on the development of fertilizing ability by spermatozoa in the epididymis of castrated hamsters.

The effects of testosterone, 17beta-hydroxy-5alpha-androstane-3-one (5alpha-dihydrotestosterone; 5alpha-DHT), 5alpha-androstane-3alpha, 17beta-diol (3alpha-androstanediol; 3alpha-diol) and 5alpha-androstane-3beta, 17beta-diol (3beta-androstanediol; 3beta-diol) on the development of fertilizing ability by spermatozoa in the epididymis were compared in castrated hamsters. The left corpus epididymidis was ligated for 14 days in intact and castrated animals to prevent the in-flow of spermatozoa into the cauda epididymidis and the ductuli efferentes were bilaterally ligated. The fertilization rate of spermatozoa in the left cauda epididymidis of control animals decreased to 71.1% after 14 days whereas that of spermatozoa in the unobstructed right cauda epididymis remained at the control level of 100%. After castration, 50 mug testosterone, 25 mug 5alpha-DHT and only 9 mug 3alpha-diol/day were the minimal doses that facilitated normal development of fertilizing ability but 75 mug testosterone, 37.5 mug 5alpha-DHT and 12.5 mug 3alpha-diol/day were required to maintain sperm survival at the control level. However, 3beta-diol was ineffective for both sperm maturation and survival.


The termination of thalamo-cortical fibres in the visual cortex of the cat.

An electron microscopic study has been made of the site and mode of termination of thalamo-cortical fibres in area 17 of the visual cortex of the cat. Thalamo-cortical fibres had been selectively interrupted 4-5 days before perfusion of the brain. In agreement with previous studies, degenerating axon terminals were found in layer I, in the deep part of layer III, and in layer IV of the cortex. In addition, a few degenerating thalamo-cortical axon terminals were found making synapses upon spines and small dendrites in layer VI. Two examples were seen of degenerating axon terminals making axo-dendritic synapses upon dendrites in continuity with their cell bodies. These neurons were not large stellate cells and were probably pyramidal.


Some cytochemical and cytological features of the so-called SIF cells of the superior cervical ganglion of the rat.

The properties of uptake and storage of dopamine and noradrenaline of the SIF cells of the superior cervical ganglion of the rat were tested, using the radioautographic method. Their ability to store exogenous catecholamines appears very poor under the present experimental conditions, in spite of the great number of storage vesicles they usually contain. This situation may be related either to the absence of a high affinity uptake mechanism in the SIF cell membrane or to a normal saturation of SIF cells in catecholamine. Cytological peculiarities of nerve terminals on SIF cells were pointed out. Dense patches attached to the inner face of the SIF cell membrane suggest a local release of vesicular contents, with further functional implications.


A method to correct adequately for the change in neuronal size when estimating neuronal numbers after nerve growth factor treatment.

A method is described to compute the correct distribution of nuclear diameters in thick sections of superior cervical ganglia of rats from the observed distribution of nuclear profiles. This method is applicable to the problem of correcting for the differing diameters of cells observed after treatment with nerve growth factor (NGF). It overcomes the errors due to the failure to count small fragments of nuclei too thin to be seen and the multiple counting of nuclei in more than one section. It has been shown that the changes in number of neurons after NGF treatment were not as large as previously supposed. An estimate of the volume occupied by the cell bodies suggests that the numbers calculated here are correct.


Morphometric analysis of rat superior cervical ganglion after axotomy and nerve growth factor treatment.

The changes in neuronal number, cell body size and nuclear size have been followed for 12 weeks after postganglionic axotomy of the rat superior cervical ganglion. Axotomy was carried out at 6 days post partum and treatment with nerve growth factor (NGF) was from 6-21 days. During normal development there is a 30% decrease in the number of neurons in the superior cervical ganglion; axotomy increases the loss of cells resulting in a 90% decrease by 28 days post partum. The normal decrease is prevented and the enhanced loss of cells after axotomy is decreased by administration of NGF. Thus the increased number of cells observed after NGF administration appears to be due to the survival of cells that otherwise would have degenerated. NGF causes a rapid enlargement of both the cell bodies and the nucleus in the normal and axotomized ganglia. This increase in size rapidly reverses after cessation of treatment. These changes in cell size may account for the previously observed changes in cell profile number with NGF. There is a large increase in the number of non-neuronal cells during normal development and axotomy prevents this increase. NGF treatment results in a 6 fold increase in the number of non-neuronal cells and it is suggested that these are required to support the massive fibre outgrowth that occurs in NGF treated ganglia. It is concluded that these results are consistent with a physiological role for NGF as the trophic substance supporting adrenergic neurons making the appropriate contact with their target cell.


On the occurrence of Schwann cells within the normal central nervous system.

The presence of Schwann cells and P.N.S. myelin are reported in subpial areas of apparently normal spinal cord from one control rabbit, two experimental rabbits and one experimental guinea pig. These P.N.S. elements exerted no adverse effects upon local C.N.S. components. The occurrence of ectopic Schwann cells in the normal C.N.S. has also been reported elsewhere in studies on normal human spinal cord tissue. The propensity for Schwann cells to reside in the normal C.N.S. of several species makes it necessary for experiments and hypotheses on the aetiology of Schwann cell invasion into the abnormal C.N.S. to take the present phenomenon into consideration.


Radiotherapy and CCNU in the treatment of high-grade supratentorial astrocytomas.

Forty-one consecutive patients with supratentorial primary brain tumors (38 Grade III and IV astrocytomas, one giant-cell astrocytoma, and two cases with insufficient tissue for diagnosis) were randomly allocated within 2 weeks of surgery to one of three therapeutic groups. Group 1 (15 patients) received radiation therapy totaling 4000 to 4500 rads in 4 to 5 weeks. Group 2 (13 patients) received 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea CCNU) 130 mg/sq m orally every 6 weeks. Group 3 (13 patients) received radiation therapy plus CCNU as for Groups 1 and 2. When the disease progressed, patients in Groups 1 and 2 were crossed over to receive CCNU and irradiation respectively. The median survival time in these groups was 188, 259, and 252 days, and the mean survival 263, 262, and 329 days. The median time from diagnosis to crossover (Groups 1 and 2) or to progression (Group 3) was 163, 99, and 220 days, and the mean time was 172, 108, and 231 days. There was no statistically significant difference between the means or medians in any of these situations.


Response to vincristine of recurrent brain tumors in children.

Seventeen children with clinical evidence of a recurrent brain tumor were treated with vincristine 1.5 mg/sq m weekly for 12 weeks with doses on alternate weeks thereafter. Eight of the 16 patients who received four or more doses of vincristine showed significant objective responses; these included patients with high-and low-grade astrocytomas and patients with medulloblastoma. Six of the eight who responded remained asymptomatic for more than 2 years. The toxicity encountered was minimal except for seizures possibly related to vincristine in three children, who were able to resume treatment. Vincristine therapy results in long-term regression in a wide variety of pediatric brain tumors and causes little or no toxicity.


Effect of dexamethasone on experimental brain edema in cats.

The authors studied the effects of dexamethasone, 0.3 mg/kg/hr administered intravenously beginning 1 hour before injury, in adult cats with brain edema secondary to cold-induced cortical lesions. Edema was quantitatively measured in cortex, gyral white matter, and central (deep) white matter at 3, 24, 48, and 72 hours, with and without dexamethasone, by determining specific gravity (density) of samples in a continuous gradient column. Cold-induced lesions resulted in edema, which was greatest in the white matter of the injured hemisphere but also present in the contralateral hemisphere. Except for a slight but significant increase in density (decreased edema) of cortex at 24 hours, dexamethasone therapy resulted in no reduction of cold-induced edema, and in some cases increased the edema.


Postoperative hypertension in the management of patients with intracranial arterial aneurysms.

Elevation of systemic arterial pressure in seven patients with intracranial arterial aneurysms has been shown to be effective in alleviating ischemic symptoms attributed to cerebral vasospasm. Autoregulation is at least partially lost in patients with cerebral hemodynamic crisis. Blood volume expansion was used to augment vasopressors in maintenance of systemic hypertension. The management of these cases is discussed. Caution in the use of this technique is advised, since the regimen is not without risk.


A method of estimating intracranial decompensation in man.

A new method of estimating intracranial decompensation in man is described. An on-line computer system is connected to an intracranial pressure (ICP) monitoring system to compute regression plots of mean ICP vs standard deviation; standard deviation is used as a measure of ICP instability. Two zones with distinctly different slopes are a characteristic feature of these plots. It is thought that the changes of slope signify intracranial decompensation.


Intercavernous connections of the cavernous sinuses. The superior and inferior circular sinuses.

Morphological features of the intercavernous connections of the cavernous sinuses are described and illustrated by photographs of vinylite casts. Surgeons should be aware of the course, potential size, and arrangement of the channels in the dura of the hypophyseal fossa. This is particularly important in exposure of pituitary gland by the transpheniodal route.


Anatomy of the cavernous sinus. A microsurgical study.

Fifty cavernous sinuses from cadavers were studied in detail using magnification, with special attention to the relationships important in surgical approaches on the intracavernous structures, and to understanding arterial contributions to arteriovenous fistulas involving the cavernous sinus. Significant findings were: 1) The three main branches of the intracavernous portion of the carotid artery were the meningohypopyseal artery, present in 100% of the specimens, the artery of the inferior cavernous sinus (84%), and McConnell's capsular arteries (28%). In addition, the ophthalmic and dorsal meningeal arteries arose from the carotid artery within the cavernous sinus in 8% and 6%, respectively. The three main branches of the meningohypopyseal trunk were the tentorial artery, present in 100%, the dorsal meningeal (90%), and the inferior hypophyseal (80%). 2) The carotid artery was separated from the trigeminal nerve just proximal to the sinus by only dura in 84% of the specimens, and the artery was exposed in the floor of the middle fossa lateral to the trigeminal nerve in 38%. 3) The intracavernous portion of the carotid artery indented the lateral side of the pituitary gland in 28% of dissections but could be as far as 7 mm from it. 4) A triangular area, described by Parkinson, through which the intracavernous portion of the carotid artery could be exposed surgically was found in all specimens. 5) The sixth cranial nerve may split into as many as five rootlets as it passes lateral to the intracavernous portion of the carotid artery. 6) The three major venous spaces within the sinus were posterosuperior, anteroinferior, and medial to the intracavernous portion of the carotid artery.


Radiosotope evaluation of experimental hydrosyringomyelia.

Kaolin-induced hydrosyringomyelia in dogs has been investigated by radioisotope ventriculography using both cerebrospinal fluid radioassay and scintigraphy. The hydromyelic central canal can be differentiated from the spinal subarachnoid space by scintigraphy, Serial studies show that hydromyelia arises rapidly to decompress the associated hydrocephalus in surviving animals. Syringomyelia, after a delayed onset, originates from the enlarged central canal. Radioisotope ventriculography may be a useful clinical aid in the diagnosis of hydrosyringomyelia.


Clinical radiosotope investigations in hydrosyringomyelia and myelodysplasia.

Radioisotope ventriculography was applied clinically in myelodysplastic hydromyelia in three groups of patients: two patients with normal ventricles, two with obstructive hydrocephalus, and 16 with myelodysplasia. In the myelodysplastic group, radioassay in one patient demonstrated flow of radioistope down the hydromyelic cavity. Twenty scintigraphic studies on 16 myelodysplastic patients showed hydromyelia was present in all patients with spontaneously compensated hydrocephalus but in none of those with functional ventricular shunts. This relation between the hydromyelia and disordered ventricular hydrodynamics supports the Gardner hypothesis of myelodysplasia. Radioisotope ventriculography appears a safe and useful method of diagnosing hydrosyringomyelia and evaluating treatment by means of ventricular decompression.


Late results of cervical disc surgery.

Late results of cervical disc surgery have been reported and statistically studied in 383 cases: 83% were lateral discs, 13% were central spondylosis discs, and 4% central soft discs. Central spondylosis occured at a higher spinal level, and caused cord compression with or without weakness of the hands, but no pain. A posterior approach was used in all lateral discs, and either an anterior or a posterior approach, with or without fusion, for central discs. Preoperative myelography was always done and is recommended postoperatively in central disc surgery to evaluate the results. Our results were good to excellent in 95% of lateral discs, in 64% of central spondylosis discs, and in an unexpected 91% of 11 cases of central soft discs. There were no recurrences and no serious complications, although 20% developed other cervical or lumbar disc herniations.


Posterior cervical fusion in chidren.

Six cases of posterior cervical fusion with rib grafts in children are reported. Four of the children had sustained cervical spine injuries in accidents, and two had congenital absence of the odontoid. Three-level fusions (C1-3) were done in four children, and four-level fusions (C1-4) in two. One child died of unrelated causes 3 months after the operation. The other five children have been followed for 5 to 13 years. All are doing well and each has a remarkably supple, stable neck and no neurological deficit.


Sciatic entrapment neuropathy. Case report.

A case of sciatic entrapment neuropathy is discussed. When evaluating patients with unilateral leg pain and paresthesias, one should consider the possibility of entrapment of peripheral nerve. Electrodiagnostic studies are helpful in establishing the diagnosis.


Hemorrhage in bilateral choroid plexus hemangiomas demonstrated by computed tomography. Case report.

The authors present a case in which bilateral posttraumatic hemorrhages in choroid plexus hemangiomas were demonstrated by computed tomography and histopathological study.


Cerebrospinal fluid fistula from fractured acrylic cranioplasty plate. Case report.

The authors report a patient who developed a cerebrospinal fluid fistula secondary to a fractured methyl methacrylate cranioplasty plate. There was no external evidence of trauma. X-ray films showed no evidence of the fracture. It is suggested that the impregnation of methyl methacrylate with a radiopaque material would result in visualization of such fractures.


Multifocal glioma of the brain. Case report.

A case is presented in which two separate concurrent astrocytomas of the brain in the same patient were successfully operated on. The patient has been followed for 3 years and remains well. The authors believe that the diagnosis of multifocal tumors can be established on clinical grounds when the tumors are remote from each other, and when there has been no recurrence of neoplasm between the lesions after a long follow-up period. It is felt that a more optimistic approach to the treatment of multifocal tumors may yield good results.


Adaptive response of lysine and threonine degrading enzymes in adult rats.

The mechanism of variation inlysine and threonine conservation was investigated by measuring the activity of the enzyme initiating the amino acid catabolism in adult rats adapted to different diets. Both liver threonine dehydratase and lysine-ketoglutarate reductase activities were increased by high protein intake. Supplementation with 2% L-lysine HCI to a 5% lactalbumin diet increased liver lysine-ketoglutarate reductase activity three-fold. Feeding a lysine-free diet or a 10% wheat gluten diet significantly decreased the activity below the level obtained by feeding a protein-free diet. In contrast, dietary threonine in either excess or deficiency did not change the liver threonine dehydratase activity. At the same level of lysine intake, an excess of dietary wheat gluten seemed to increase the liver lysine-ketoglutarate reductase activity much more than dietary lactalbumin. These data suggest that the activity of lysine-ketoglutarate reductase in rat liver might be influenced by dietary lysine as well as excesses of other amino acids in wheat gluten. The different response of these two catabolic enzymes to their substrate might explain the variation of lysine and threonine conservation during amino acid deficiency.