Biomedical subjects
Publications and source records attributed to R Cohen.
A procedure for the treatment of sliding esophageal hiatal hernia and gastroesophageal reflux has been successfully and safely performed upon 46 patients. It is based on the placement of a ringlike silicone prosthesis around the lower part of the esophagus, below the diaphragm.
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Two cases of solitary small intestinal lipoma are presented. One occured in the duodenum as a submucosal pedunculated polyp with a bleeding ulcerated surface. This was diagnosed by means of the fiberoptic duodenoscope (Olympus D1G2). The second involved a large massive submucosal lipoma which formed the leading edge of an intussusception resulting in small bowel obstruction. A brief review of the pathology, complications, symptoms, radiographic diagnosis and treatment of small intestinal lipomas is given.
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These studies were to evaluate the effects of humoral factors on amplification of nonrecognizable erythrocytic and granulocytic precursors by the in vivo plasma clot diffusion chamber and the in vitro plasma clot culture methods. Changes in the plasma erythropoietin levels in the reticulocyte concentration and hematocrits of irradiated and nonirradiated Long-Evans rats exposed to hypoxia were also determined. While erythropoietin plasma concentrations appeared to affect BFU-E and CFU-E growth, results suggest erythropoietin may not be the sole regulator of red cell production and that inhibitors of chalone-like mechanisms may be involved. Measurements made on granulocyte precursors treated with colony stimulating factor (CSF) containing L-cell-conditioned medium revealed granulocytic colonies and burst-like formations similar to those seen for erythrocytic growth. There is strong evidence suggesting that CSF is a regulator of granulopoiesis; however, it is not the sole regulator and it appears that inhibitors may play an in vivo role. Growth of colonies with cell numbers not a power of 2 implies either asymmetric mitosis due to loss of genetic information required for continuing division, or differences in concentrations of, or ability to recognize, inhibitory factors. These possibilities are examined in the light of results from in vivo and in vitro culture techniques.
A simple to operate, nontechnical quality assurance program was developed to evaluate the support services provided at this Veterans Administration hospital. The program has received unanimous support from the entire hospital staff and promises to be a highly effective, and practical, program.
The experimental literature on changes in verbal self-report, psychophyiological reactions and overt motor behavior under stress or therapy is reviewed. The concordance of changes across the systems is generally low, their order difficult to predict. The correlation of changes is interpreted to depend--besides crucial methodological issues--on the preparedness of the subject to test and to modify his propositions defining in which situations he might experience certain somato-visceral reactions and emit certain overt motor acts successfully.
The hydrolysis of D-erythro beef brain sphingomyelin and D,L-erythro-N-palmitoylsphingomyelin dispersed as multilamellar liposomes by sphingomyelinase of Staphylococcus aureus is correlated with the thermotropic behavior of the sphingomyelins. In both cases maximal enzymatic hydrolysis was achieved at the beginning of the gel to liquid crystalline phase transition (30 degrees C for beef brain sphingomyelin and 41 degrees C for N-palmitoylsphingosine-phosphorylcholine) with much lower activity both below and above these temperatures. The enzymatic activity was depressed in the presence of cholesterol in the bilayer which also depressed the phase-transition. The profile of the enzymatic activity is explained by the uniqueness of the lipid molecules arrangement at the phase transition.
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Broca's aphasics, Wernicke's aphasics, brain-damaged patients without aphasia, and chronic schizophrenics were tested on a task to match meaningful sounds to one of four pictures. One of the depicted objects was the natural source of the sound, one was an object belonging to the same semantic category as the correct object, one was an object producing acoustically similar sounds as the correct object, and one was an object not related either semantically or acoustically to the correct object. In one item set the "semantic" distractors produced a sound completely different from the presented one; in another item set the "semantic" distractors made practically no specific sounds at all. Broca's and Wernicke's aphasics were shown to have significantly higher total error scores than brain-damaged patients without aphasia and to make significantly more "semantic" errors only on the first item set and "acoustic" errors on both item sets than the brain-damaged patients without aphasia. However, after correcting for guessing the differences between groups with respect to "semantic" and "acoustic" errors vanished. The aphasics' difficulties in coping with the sound-picture matching task might be difficulties in processing the acoustic dimensions of the items. It is, however, suggested that the impairment is not perceptual but of the cognitive kind repeatedly demonstrated in tasks which require the analytic extraction of features of the stimulus or of the concept represented by the stimulus.
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Evoked potentials and reaction times were obtained from chronic schizophrenics and normal controls to light and sound stimuli presented in random order. In the 'certain' condition subjects were told what the next stimulus would be, in the 'uncertain' condition they were asked to guess. Amplitudes were usually larger for normals than for schizophrenics, for 'uncertain' than for 'certain' conditions, and in cross- than in ipsimodal stimulus-sequences. The effect of certainty was stronger in normals across 4 leads; so was the effect of modality shift at vertex. While these findings replicate earlier results from acute schizophrenics, no condition X group interactions could be found in the reaction time measures. Two additional results were interpreted as showing basically different attitudes with respect to the predictability of events: (1) there was a slow positivity between the verbal information and the following stimuli which was largest for schizophrenics in the conditions of certainty; (2) while normals showed long-term habituation only in N1- but not in P3-amplitudes, the reverse was true for schizophrenics.
One hundred and twenty seven randomly selected Polish Jews were studied for their HLA polymorphism. Gene frequencies exceeding 0.1 were detected for A1, A2, Aw19, B14, Bw16 and Bw17. Significant gametic association was observed for (A1, Bw17), (A2, B27), (Aw26, Bw16), (Aw19, B13) and (A28, B14). Although a predominantly Caucasoid population, the Polish Jews show greater resemblance to Middle Eastern rather than to Northern European Caucasoids.
One hundred and twenty three Iraqi Jews, now living in Israel, were studied for their HLA polymorphism. Gene frequencies exceeding .1 were found for A1, A3, Aw19, B5, B12, and Bw35. A28, B8 and B14 were relatively rare whereas Aw25 and Bw37 were not found at all. Significant gametic associations occurred for (Aw23, Bw21), (Aw26, Bw16), (A11, B5), (A28, B8) and (A28, B7). The Iraqi Jewish population was found to be typical of Asiatics and Middle Easterners.
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A study with chicks was conducted to compare the relative vitamin K3 stability of various menadione preparations in mash and pellets. The preparations assayed were menadione sodium bisulfite, menadione sodium bisulfite complex, menadione dimethylpyrimidinol bisulfite and Kastab (a physically stabilized preparation of menadione sodium bisulfite). Pelleting increased the stability of all preparations when measured by the partial thromboplastin assay. The general trend in stability obtained by both procedures was in decreasing order: Kastab, menadione dimethylpyrimidinol bisulfite, menadione bisulfite complex and menadione bisulfite. Stability, determined chemically in vitamin microelement premixes, gave similar results.
Research dealing with the public's perception of the quality of life of the dentist is not well developed. Generally, the approach of researchers to this topic has been to examine the public's image of the dental profession. Specifically, the degree of prestige attributed to the dental profession by the public has attracted major attention. A review of studies reveals that while the profession enjoys relatively high prestige, it is extrinsic factors rather than the intrinsic value of the service that determine the public's image. The dental health care system and dental education as presently structured do not appear to be serving the bast interest of the public. The paper concludes with a discussion of what are considered to be major issues that the dental profession both in Canada and elsewhere will have to deal with in the coming years, in order to bring about change both in its image and the generally low utilization of the services it provides.
Partial trisomy 18 is described in a two month old female with severe mental, motor and growth retardation, associated with multiple congenital anomalies characteristic of complete trisomy 18. Trisomy for almost all of 18q resulted from adjacent I segregation of a paternally inherited translocation t(13; 18)(q32:q11). The balanced translocation was observed in three generations of the family. Partial trisomy 18q identical to that observed in the proband was found in a subsequent miscarriage.