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Biomedical subjects

A Levy

Publications and source records attributed to A Levy.

At least 451 records · Page 25Linked to original sources

General porokeratosis associated with primary hypoparathyroidism.

A case of generalized porokeratosis occurring in a man with primary hypoparathyroidism is reported herein. This, apparently, is the first reported case of these two disorders co-existing in a single patient. His porokeratotic skin changes were of wide morphologic and clinical variation and presented in the following forms: 1. Mibelli's plaque-type; 2. superficial disseminated eruptive-form; and 3. clavi-like lesions.

Adult↗

Smooth pursuit pattern in schizophrenic patients during cognitive task.

Asymmetries in saccadic pursuit were studied, using EOG, ion 20 schizophrenic patients, as well as in two groups of normal subjects, screened for their patterns of lateral eye movements (LEM). Tracking performance was also examined while subjects were concurrently engaged in performing a cognitive task. Saccadic pursuit among schizophrenic patients was replicated in the present study. No asymmetry was observed in the quality of leftward as compared to rightward tracking. However, solving syllogisms while tracking resulted in further deterioration in tracking performance of the patients, with significantly more saccades and arrests in tracking occurring when following the target to the left as compared to rightward following. Similar asymmetry was observed in one group of controls who are believed to rely more on their left hemisphere on the LEM test, whereas no asymmetry was observed in the performance of the second control group. These results are interpreted as supporting the hypothesis of left hemispheric hyperactivity in schizophrenia. Saccadic pursuit in one subgroup of the normal sample is considered as suggesting that these individuals belong to the high-risk group.

Adolescent↗

Mössbauer spectroscopy of Escherichia coli and its iron-storage protein.

57Fe Mössbauer spectra of whole frozen Escherichia coli cells and of an iron storage protein isolated from iron-rich cells of E. coli have been measured over a range of temperatures down to 0.08 K. The spectra of E. coli cells with high iron content and of the iron storage protein were found to be very similar. Above 4 K these spectra consist of a quadrupole split doublet characteristic of Fe3+. Below 3.5 K, the spectra display magnetic hyperfine splitting which is temperature dependent, and point to the existence of an ordered magnetic phase associated with a saturation magnetic hyperfine field of 43 tesla in both samples. The results indicate that the bulk of iron in the iron-rich cells is in the form of aggregates similar in nature to the iron cores in the isolated protein, although the latter account for not more than 1% of the total iron in the cells. The Mössbauer spectra of the isolated protein are different from those observed in ferritin, the iron-storage protein of plants and higher animals, showing that the iron cores in these two proteins are different.

Escherichia coli↗

Efficient transfer of highly resolved small DNA fragments from polyacrylamide gels to DBM paper.

A procedure is described that combines high resolution of small DNA molecules (10 to 250 bases) with high transfer efficiency from polyacrylamide gels to diazobenzyloxymethyl (DBM) paper. The DNA fragments are separated electrophoretically in denaturing or nondenaturing step gels. These consist of a short gel of relatively high polyacrylamide concentration (8%) above a long gel of relatively low polyacrylamide concentration (4%). Step gels permit a high resolution of small DNA fragments in gels of sufficiently low polyacrylamide concentration from which efficient transfer to DBM paper is feasible. The combination of the step gel with a short treatment of the gel before transfer ensures a high transfer efficiency. As much as 30% and 50% of the DNA applied to nondenaturing and denaturing gels, respectively, are bound covalently to the DBM-paper. Optimal conditions for hybridization to DBM-linked DNA molecules of 30 to 250 base length are described.

DNA↗

Contact dermatitis in children.

It is generally admitted that contact dermatitis seldom appears in children. Eighty-seven cases, however, have been diagnosed at the Department of Allergology of the Dermatological Clinic in Strasbourg in the past 10 years (1969-1978). No element of atopic diathesis could be found in any of them. We have reviewed the cases with a positive patch test to try to derive both theoretical and practical conclusions.

Adolescent↗

Iron storage in Mycoplasma capricolum.

Considerable quantities or iron were incorporated into the Mycoplasma capricolum cell membrane. Mossbauer studies showed that the iron is in a form which becomes magnetically ordered at low temperatures. The iron-enriched cells contained membrane-bound electron-dense particles of about 6.0 nm in diameter.

Cell Membrane↗

Chromosome damaging agent of low molecular weight in the serum of New Zealand black mice.

Two substrains of NZB mice were developed by selective matings according to chromosome breakage frequencies in direct bone marrow preparations: HB, a line with increased chromosome breakage, and LB, a line with low or normal breakage rates. The serum of NZB mice from the HB strain contains a chromosome breaking factor that produces chromosome abnormalities in human lymphocytes. This clastogenic substance could not be detected in serum of NZB line. Nor does it exist in serum of Balb, C3H, C57 B1, Swiss, or AKR mice, in which no chromosomal breakage was observed in bone marrow. The breakage factor has a molecular weight between 1000 and 10,000 daltons.

Animals↗

Tumor incidence and development of autoimmune hemolytic anemia in two breeding lines of the NZB mouse strain that differ in chromosome breakage.

Increased chromosome breakage observed in NZB mice was studied. Breeding experiments with mice selected according to breakage frequencies provided evidence that the proportion of mice with high breakage (HB) and low breakage (LB) figures in the progeny depends on the phenotype of the parents. Selective breeding for the "chromosome breakage" characteristic was successful and resulted in the separation of a breeding line with LB incidence. However, the selection could not be continued beyond the fourth generation for the mice with HB incidence because of lethal factors. Comparative studies of HB mice from the HB line and LB mice from the LB line showed significant differences for tumor incidence and positivity of the Coombs' test.

Age Factors↗

The effect of propranolol treatment in shizophrenia on CSF amine metabolites and prolactin.

Recent reports have suggested that high doses of propranolol may be an effective treatment in schizophrenia. To determine whether such treatment has effects on cerebrospinal fluid (CSF) amine metabolites and prolactin similar to the effects of the neuroleptic drugs, we studied CSF from ten patients before and after propanolol therapy. The initial CSF sample was removed after a drug-free period and propranolol dosage was then increased over 1 week to 1000 mg daily in all ten patients. A second CSF sample was removed after 3 weeks of propranolol therapy. Propranolol levels and prolactin in CSF were measured by radioimmunoassay. Homovanillic acid, 5-hydroxyindoleacetic acid, and 3-methoxy-4-hydroxyphenylethylene glycol were measured by gas chromatography-mass spectrometry. Propranolol had no effect on the prolactin or amine metabolite concentrations. CSF propranolol levels averaged 40 ng/ml (range less than 1--78).

Adult↗

Chromosomal breakage in Crohn's disease: anticlastogenic effect of D-penicillamine and L-cysteine.

The incidence of chromosome breakage was found to be elevated in 42 patients with Crohn's disease. This phenomenon was much more striking in cultures set up with TCM 199 than in cultures set up with RPMI 1629 rich in L-cysteine. The drug D-penicillamine, a close analog of L-cysteine, gave an apparent therapeutic response in several patients and reduced the chromosome breakage frequency in the lymphocytes of these patients in vitro and in vivo.

Cells, Cultured↗

The Abortion and Sterilization Act in 1975--experience of the Johannesburg Hospital Pregnancy Advisory Clinic.

The experience of a Pregnancy Advisory Service operating in terms of the Abortion and Sterilization Act of 1975 is reviewed. A total of 454 applications for abortion were considered, of which 198 (44%) were accepted and the abortions performed. The urgent need for sex education at schools, colleges and universities is stressed, in view of the large number of scholars and students under the age of 17 who seek an abortion. There are also patients who discontinue contraception for a variety of reasons, on medical advice or otherwise, without an alternative being suggested or sought. Motivation of patient, nurse and doctor needs urgent improvement.

Abortion, Legal↗

Paget's disease with spinal cord compression. Favourable course after decompression and calcitonin treatment in two cases.

Two cases with spinal cord compression due to Paget's disease (osteodystrophia deformans) are reported, which were treated with calcitonin (Salmon Calcitonin) during 12 and 24 months after decompressive laminectomy. Both presented a favourable clinical course with improvement of sensory and bladder disturbances, paraparesis and pain. Diagnostic criteria as X-ray investigation, scintigraphy of bones, biochemical parameters and the long-term treatment whith calcitonin, are discussed.

Calcitonin↗