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Biomedical subjects

M A Wolf

Publications and source records attributed to M A Wolf.

At least 37 records · Page 2Linked to original sources
PubMed1989

[Dopanergic agonists and schizophrenia].

The neutrotransmitter dopamine mediates its central nervous system actions via 2 types of receptors: D1 and D2, each of which exist in a low or a high affinity state. In schizophrenic patients, it appears that part of the symptomatology may be secondary to dopaminergic hyperactivity (the so called positive symptoms), whereas negative symptoms would be secondary to structural damage. Antipsychotic drugs that are used in clinics are antidopaminergic. It is interesting to note that those drugs are ineffective in part of the schizophrenic population, the chronic one. This inefficiency might be due to primary resistance or to adaptation of the central nervous system to the drugs. Some authors tried dopamine agonists to treat schizophrenic patients. Apomorphine, N-n-propylnorapomorphine, l-DOPA and bromocriptine were tried. The purpose of these substances was to desensitize dopaminergic system, or to inhibit it via presynaptic autoreceptor stimulation, depending of the study. Some authors hypothesized a drop in frontal cortical dopaminergic system to explain part of the schizophrenic symptomatology. Dopamine agonists might act at this level to enhance frontal dopaminergic activity. After those experimentations with dopamine agonist drugs, it appears that 2 of them might have efficiency and clinical use: l-DOPA and bromocriptine.

Bromocriptine↗
PubMed1987

[Current hypotheses on the mechanism of action of lithium].

This article aims to clarify and organize the recent advances in research on the central action mechanism of lithium. It begins by tackling the process of cellular transport of the cation, then it moves on to describe the effects of lithium on ionic distribution and on membranous functioning in general. Neurotransmission in this article is the object of a more detailed study. The metabolism of neurotransmitters (and their disturbances) is first discussed. The emphasis is placed on certain current domains, the gabaergic system in particular. Neurotransmitters, by themselves, do not satisfy any longer the curiosity of biologists. Technological progress has given these scientists access to the intimate functioning of receptors and to their natural support system, the membrane. The stabilizing effect of lithium is mentioned often. Initially seen at a superficial level, it leads to a study of the mechanisms of the transference of information from the receptor to the cell. The membranous phospholipids and the enzymatic systems controlling the metabolism of the second messengers (cyclic nucleotides but also calcium) will provide as many potential targets to the action of lithium.

Bipolar Disorder↗
PubMed1986

Play diversity and structural relationships in the play and language of language-impaired and language-normal preschoolers: preliminary data.

The purpose of this study was to compare structural play-language relationships and diversity of symbolic play skills in age matched language-impaired and language-normal children. The language-impaired and language-normal children differed in their play-language correspondences when the structural metrics of mean length of utterance (MLU) and mean length of sequence (MLS) were used. Differences between the groups were also found on specific quantitative and qualitative aspects of symbolic play. Suggestions for play intervention are discussed.

Child, Preschool↗
PubMed1980

A trial of two strategies to modify the test-ordering behavior of medical residents.

We studied two methods to reduce the ordering of laboratory and radiologic tests by medical residents in their first postgraduate year. Dividing the residents into three groups, we compared the effect of concurrent chart review and discussion in one group with the effect of a moderate financial incentive for limited ordering of tests in a second group. The third group of residents served as a concurrent control, and data on the testing patterns of residents at the same hospital during the year before the study provided a retrospective control.

Boston↗
PubMed1975

The melanocytotoxic action of 4-hydroxyanisole.

Cultured normal mammalian melanocytes exposed to a variety of antioxidants in the presence of millimolar concentrations of 4-hydroxyanisole exhibit dose-dependent modifications of cytotoxicity. While some antioxidants reduced the extent of damage produced by 4-hydroxyanisole, others appeared to increase it. Similar effects were found in a model system using lysis of human erythrocytes as an index of cell damage. Estimations on rat liver microsomes in the presence of tyrosinase and 4-hydroxyanisole showed increased peroxidation only at low substrate concentrations.

Aldehydes↗
PubMedDate not supplied

Chiasmopathy?

A 57-year-old man presented with progressive visual loss in both eyes, bitemporal field defect, and a history of poor nutrition, alcohol abuse, and excessive cigar smoking. Magnetic resonance imaging was normal. The visual acuity and field defect improved with supplementation with vitamins and reduction of alcohol and tobacco consumption. A diagnosis of toxic optic neuropathy was made. The authors discuss the differential diagnosis of bitemporal/pseudobitemporal field defects and the diagnosis and treatment of toxic optic neuropathy.

Amblyopia↗
PubMedDate not supplied

Neuropsychological impairments in the syndromes of schizophrenia: a comparison between different dimensional models.

This study investigates the associations between the different symptom dimensions of schizophrenia and neuropsychological performances. Globally, the results replicate previously described associations. The "negative" dimension correlates with impaired sustained attention and working memory, thus suggestive of dorsolateral frontal cortex dysfunction. "Disorganization" correlates with the ability to inhibit proactive interference. thus with ventromedial frontal dysfunction. The results also add support to the view that the "psychotic" dimension described in three-dimension models includes in fact two distinct dimensions, (1) "hallucinations," here associated to episodic memory measures, and (2) "delusions", here associated to visuospatial attention, thus suggestive of mediotemporal and posterior neocortical dysfunction, respectively.

Adult↗