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Biomedical subjects

M Wolf

Publications and source records attributed to M Wolf.

At least 487 records · Page 27Linked to original sources

Long-term culture of neurones from human cerebral cortex in serum-free medium.

A method for cultivating neurones from the fetal human central nervous system in the absence of glial cells is described. Brain cells from 15-18-week-old human fetuses are plated on polylysine-coated surfaces and grown in a serum-free hormonally-defined medium. About 98% of the cells were identified as neurones using tetanus toxin as a marker. The cultures survive for up to 7 weeks and develop an extremely complex network of neurites.

Cells, Cultured↗

The genetic significance of accessory bisatellited marker chromosomes.

Ten new cases of accessory bisatellited marker chromosomes examined in different laboratories are reported. As a basis for genetic counseling in the context of prenatal diagnosis a cytogenetic categorization of such marker chromosomes is proposed and an estimation of the genetic risk associated with each category is carried out. The results are as follows: There is no increased risk for offspring with abnormal phenotype born to a healthy carrier of an accessory bisatellited marker chromosome with either a single or two closely adjacent C-bands (Category AI or AII). The unbiased sample of cases with de novo accessory bisatellited marker chromosomes of categories AI and AII is too small to allow a satisfactory estimation of the actual risk that, in case of such a prenatal finding, the foetus may not show a normal phenotype as a consequence of the marker chromosome. There is, however, evidence that this risk may be lower than 10%. Accessory bisatellited marker chromosomes showing a discrete pattern of G- and R-bands situated between two distant C-bands (Category AIII) usually indicate a chromosomal imbalance giving rise to an abnormal phenotype. Mosaic carriers of such dicentric marker chromosomes may, however, present a normal phenotype.

Abortion, Spontaneous↗

Lexical creativity during instances of word-finding difficulty: Broca's vs. Wernicke's aphasia.

Lexical innovation--the creation of a word by combining existing morphemes in a novel way (e.g. "map ball" for "globe")--was evaluated as a method for circumventing word-finding difficulty in Broca's and Wernicke's aphasia. Aphasic groups were matched for naming performance and compared to a control group of normal adults matched for age and education. Lexical innovations were collected during the administration of a confrontation naming test, and were then analyzed in terms of the correctness of morpheme combination, semantic accuracy, novelty, and communicative effectiveness. An innovation was considered to be communicatively effective when its intended referent was understood by a naive judge. The lexical innovations of the two aphasic groups were diametrically opposed: as compared to both Broca's aphasics and normal adults, Wernicke's aphasics innovated significantly less often, and their innovations were significantly inferior in terms of: semantic precision, the proper construction of morpheme combination, and communicative effectiveness. This pattern suggests that lack of verbal fluency may be compatible with lexical creativity, while empty logorrheic speech may be an impediment to lexical creativity. Similarly, we conclude that the agrammatism of Broca's asphasia does not interfere with lexical innovation, while the paragrammatism of Wernicke's aphasia does interfere with lexical innovation, thus suggesting that paragrammatism affects morpheme combination at the word level as well as the sentence level.

Aphasia↗

Electrophysiologic tests in assessment of senile macular degeneration.

Twelve patients with macular disease were studied. Mean age at the beginning stages of the disease was 61.75 years. They were examined by biomicroscopy, fluorescein angiography, and electrophysiological tests (ERG, EOG, VEP). No relevant correlation could be found between the routinely administered and evaluated ERG and EOG tests and the clinical stage of the disease. The VEP proved a more sensitive means of evaluating macular function in our patients. The possibility of the VEP's being of prognostic importance is raised.

Aged↗

Characterization of sister chromatid exchange induction by hydrogen peroxide.

Hydrogen peroxide (H2O2) induces SCEs in V-79 Chinese hamster cells. The incorporation of BrdUrd sensitizes the cells to the action of H2O2, but damage leading to the formation of SCEs can also be induced in DNA not substitued with BrdUrd. Catalase leads to a complete reduction of the SCE-producing as well as the toxic effect. The amino acid L-cysteine does not reduce the H2O2-induced SCE-frequencies. The results yield information about the relevance of SCE investigations in vitro for the determination of DNA-damaging substances and about the effects of antimutagenic SH-compounds.

Animals↗

Rosette inhibition test: a multicentre investigation of early pregnancy factor in humans.

The rosette inhibition test for the detection of early pregnancy factor is described in detail. The extended methodology presented here represents the cumulative experience of three independent laboratories. Special reference is made to the effect on the assay of varying the conditions of rosette formation between lymphocytes and sheep red blood cells. Antilymphocyte sera prepared for use in the rosette inhibition test fell into three categories: (i) with no rosette inhibiting activity, (ii) with rosette inhibiting activity which is not affected by the presence of EPF, and (iii) rosette inhibiting activity which is significantly increased in the presence of EPF. To date, this third reaction has been found to be a specific indication of the presence in serum of early pregnancy factor.

Animals↗

Treatment of congenital antithrombin III deficiency with concentrates.

Antithrombin III concentrates were administered to a patient with hereditary AT III deficiency undergoing orthopaedic surgery. The plasma AT III level (heparin cofactor activity) was maintained at values in excess of 100% postoperatively. A mean dose of 0.74 u/kg (range 0.64 - 0.83) of AT III resulted in a 1% increase in AT III level after concentrate infusion. The half-life of AT III (mean 66 h; range 58-76) was shorter during surgery and in the early postoperative period suggesting an increased consumption of the inhibitor. At III antigen was consistently higher than heparin cofactor activity during the first 24 h after concentrate infusions. This discrepancy was associated with the presence in the patient's plasma of an AT III fraction showing a slower mobility than the main AT III peak on two-dimensional immunoelectrophoresis in the presence of heparin. A biological assay is preferred to an immunological assay in monitoring replacement therapy with AT III concentrates.

Adult↗