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Biomedical subjects

M Petit

Publications and source records attributed to M Petit.

At least 127 records · Page 7Linked to original sources
PubMed1981

Study of rat lymphocytes by use of peanut agglutinin.

Peanut agglutinin (PNA) was used to identify rat lymphocyte subpopulations. The binding of PNA on the surface of lymphocytes was assessed by fluorescence microscopy using fluoresceinated PNA. It was shown that most of the thymocytes and bone marrow cells have receptors for PNA; in spleen and lymph nodes the percentages of PNA-positive cells are around 40%. PNA was also used as a potentially mitogenic lectin. It was ascertained that lymphocytes incubated with PNA are stimulated only if they are pretreated with neuraminidase, and that only 'immunocompetent' thymocytes exhibit a very weak response. The fact that PNA slightly inhibits the [3H]uridine uptake of resting thymocytes might explain the weak mitogenicity of PNA.

Animals↗
PubMed1981

Three-pool analysis for quality control: a method for daily differentiation of analytic error from random variability.

Using the Z statistic we have devised a novel, mathematically simple concept for daily quality control of laboratory procedures. The method allows rapid identification and differentiation of systematic errors from random variability on a daily basis, increases confidence in the accuracy of reported results, reduces the number of repeat analyses, and allows the analyst to detect a deteriorating quality control pool. Using three controls instead of one or two increases the chance of detecting out-of-control situations and uses simplified statistical calculations summarized on a single graphic wall chart to monitor the daily accuracy and precision of analytic procedures. The method is adaptable to any type of specimen quantitatively analyzed and can be used in large or small laboratories with light or heavy workloads. This paper reflects what happens in a small laboratory with only one run each day, but, the system has been tested in a large community hospital with a heavy workload and multiple runs each day. Although this procedure is presented for the clinical laboratory, the method would be equally useful in industry.

Laboratories↗
PubMed1979

[Cytolysis through cells dependent on immunization against cellular antigens: identification and enumeration of cytotoxic cells].

In this report we show how to identify and enumerate alloantigen-dependent killer cells. Individual effector cells are associated by micromanipulation to target cells and the doublets are incubated at 37 degrees C. Killers are identified by the lysis of the associated target. Killer cells can be subdivided into two subpopulations: cell responsible for the lysis of the specific target cells which bear the immunizing H-2 antigens and cells which kill only lectin pretreated targets.

Animals↗
PubMed1979

[The stimulant effect of neuroleptics: myth or reality?].

On the basis of clinical observations and animal pharmacology, the hypothesis of two types of neuroleptics may be considered. Some neuroleptics ("monopolars") are always sedatives, whatever will be the dosage used practically. Other neuroleptics ("bipolars") would be stimulating at a low dosage and sedatives at a high dosage. Stimulation and sedation would be in relation with pre- and post-synaptic dopaminergic receptors blockade.

Animals↗
PubMed1979

[Chronology of the extrapyramidal effects of neuroleptics, and the nigrostriatal dopaminergic system].

Authors after analysis of the data in literature describe the chronologic appearance of the extrapyramidal effects of neuroleptics. In order to restore a neurophysiological coherence to dissimilar or even contradictory clinical emergences this sequence is analysed in function of the actual data, relative to the mechanism and to the modalities of adaptation of the dopaminergic synapse of the nigro striatal system.

Akathisia, Drug-Induced↗
PubMed1979

[Depressive symptomatology and type of treatment (author's transl)].

Details of treatment remain imprecise in depression, as the trials of antidepressants have been more concerned with overall effectiveness than with specificity. The aetiology in depression does not provide sufficient guidance for treatment, even though drugs are preferred for endogenous depression and psychotherapy for neurotic depression. An unitary formulation of depression can be postulated on the basis of the concept of regression; endogenous and reactive depression would then stem from the nature of the depressed subject's personality. Such an approach can encompass the various possible aetiologies in depression: biochemical, psychological and social, without necessarily contrasting them. In this connection, depression is a psychobiological syndrome within which there may be different symptomatic pictures, depending notably upon the various monoamine hypotheses raised in numerous studies. In that event, possible correlations between biochemical abnormalities and certain clinical manifestations may better guide the selection of drugs.

Adjustment Disorders↗
PubMed1978

[Depressive states: clinical symptoms and monoaminergic hypothesis].

Twenty somatic symptoms are listed, that are often met in depressive states but that are presently neglected by clinicians and by the various depression rating scales. Thanks to the data provided by animal pharmacology and clinical studies, an attempt to correlate the clinical studies with the biochemical results is proposed between those symptoms and eventual monoaminergic dysfunctions. This study leads to a clinical observation scale. In the future, the authors envisage a multifactorial analysis of the data obtained by the use of the scale. Symptomatic groupings could help establish a new classification for depressive states. They could also guide the choice of the medication according to the monoaminergic dysfunctions that are pointed out.

Depression↗
PubMed1975

Continuous sutures in replacement of mitral and tricuspid valves with prostheses.

Four years' experience with 363 patients, in whom 360 mitral and 65 tricuspid prosthetic valves have been implanted with single continuous sutures, is presented. The occurrence of prosthetic valve detachment is particularly discussed. There were 4 cases of detachment of the prosthetic mitral valve and no cases of tricupsid dehiscence. All 4 patients with detached valves required reoperation. Calcifications that penetrate into the annulus and myxomatous degeneration of the valve are considered more important factors in the production of prosthetic cases so long as a uniform distribution of stitches is maintained (not too close to each other) and excessive tension in the suture line is avoided.

Adult↗
PubMed1975

Segmental urethrectomy and urethrorrhaphy for treatment of fresh and late traumatic urethral lesions.

For 16 years we have used segmental urethrectomy with end-to-end urethrorrhaphy for treatment of traumatic urethral lesions, in preference to two-stage urethroplasties. The approach has been transperineal, retropubic, and if necessary transpubic. Good results in 41 cases with long-term follow-up allow us to say that this is a good operation. It provides in two thirds of the patients a correct and stable urethral stream, complete bladder emptying, and does not affect urinary control or sexual function if this was normal following the injury.

Adult↗
PubMed1975

Symphysiotomy or transpubic approach to traumatic strictures of the posterior urethra.

The trans-symphyseal or transpubic approach is a useful technique which gives a very good exposure of the prostatic and membraneous urethra. We have used it on seven patients, for repair of post-traumatic strictures of the posterior urethra, complementary to the transperineal route in most difficult cases. This technique has allowed a correct anastomosis between the distal and the prostatic urethra in all these cases. The short-term results are good and no lasting orthopaedic sequelae have been observed.

Abdominal Muscles↗