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Biomedical subjects

M Plat

Publications and source records attributed to M Plat.

At least 19 recordsLinked to original sources
PubMed2002

Characterization of the fertility of Kit haplodeficient male mice.

The role of the proto-oncogene Kit expression during gonadal development, then in differentiated spermatogonia has been thoroughly established. The present study was designed to investigate the consequences of a partial defect in Kit gene expression on sperm fertilizing ability, using Kit haplodeficient mice (kitW-lacZ/+). Same inbred mice (kit+/+) were used as controls. Epididymal sperm characteristics and in vivo fertility were assessed, then in vitro-fertilization experiments were carried out for mice of both genotypes. Epididymal sperm count was drastically reduced, and sperm motility was also decreased in kitW-lacZ/+ compared with kit+/+ males. Both in vivo or in vitro fertility were greatly reduced in kitW-lacZ/+ compared with kit+/+ males. By contrast, the fertility of kitW-lacZ/+ females was apparently unaffected. Additionally, a higher number of spermatozoa with undetected acrosomal contents was revealed by fluorescein isothiocyanate-labelled Pisum sativum agglutinin acrosomal staining after epididymal sperm retrieval in kitW-lacZ/+ mice, whereas no difference was observed after induction of acrosomal reaction in mice of either genotype. Ultra-structural data confirmed the higher frequency of abnormal acrosome in spermatozoa of kitW-lacZ/+ mice. Thus, sperm production is impaired in Kit haplodeficient mice both on a quantitative and a qualitative basis. Finally, we show that one single copy of Kit gene is not sufficient to maintain genuine fertility in male mice.

Animals↗
PubMed1999

[Pulmonary malacoplakia caused by Rhodococcus equi in AIDS: a case report].

We describe the observation of a right upper lobe consolidation with cavitation produced by Rhodococcus equi in a patient suffering from AIDS. The inefficacy of a prolonged antimicrobial therapy adapted against R. equi led to a right upper lobectomy. The histopathology showed a pseudotumoral mass, with dense infiltration of macrophages containing Michaelis-Gutmann bodies, which was positive for the culture of R. equi. Pulmonary malacoplakia with Rhodococcus equi was diagnosed. This pathology should be evoked when a R. equi pneumonia persists despite a right management of treatment for several months. The features of pneumonia with Rhodococcus equi and of pulmonary malacoplakia are taken from a literature review.

AIDS-Related Opportunistic Infections↗
PubMed1994

6-Fluoro-serotonin as a substrate for the neuronal serotonin transporter.

6-Fluoro-serotonin (6F-5-HT) was previously identified in the rat brain after peripheral administration of 6-fluoro-DL-tryptophan, a serotonin (5-HT) synthesis inhibitor. These present studies, performed with rat brain synaptosomes show that: i-neuronal 6F-5-HT uptake partly involved the 5-HT transporter since it was inhibited by clomipramine, a 5-HT uptake inhibitor, ii-6F-5-HT blocked the synaptosomal uptake of 3H-5-HT, with an IC50 value of 98 +/- 13 nM, and iii- 6F-5-HT induced 3H-5-HT release from preloaded synaptosomes, with an EC50 value of 95 +/- 6 nM; this release was decreased in the presence of clomipramine, suggesting the involvement of the 5-HT transporter. This release was also reduced when using synaptosomes from reserpinized rats, suggesting that the vesicular pool also participates to the 3H-5-HT release induced by 6F-5-HT. So, 6F-5-HT behaved as a substrate for the 5-HT neuronal transporter.

Animals↗
PubMed1990

[Abdominal ultrasound diagnosis of malignant lymphomas].

The abdominal clinical staging in malignant lymphomas should be started from sonography. The size of detectable lymph nodes and focal lesions in liver and spleen (to 0.5 cm on favourable conditions of examination) reflects a comparable position of ultrasound, computed tomography and magnetic resonance imaging. The last called method seems to be advantageous only in the pelvic region. Involved lymph nodes in malignant lymphomas on the contrary to metastatic infiltration in carcinomas appear for the most part hypoechoic. The sonographic findings in liver, spleen, pancreas and kidneys infiltrated by lymphomas and other malignant diseases do not differ significantly. The involvement of gastrointestinal tract can be associated with the so called "bull's eye"-, "target"- or "pseudokidney"-sign. The endoscopic sonography could improve the preoperative staging by measuring thickened gastrointestinal wall structures and by detecting infiltrated neighbouring organs. Ultrasound-assisted needle biopsies are useful. However the favourable results reported (sensitivity, positive correlation, concordance-100%) seems to be connected with low number of cases involved. Remarkable proportion of false negative results should be expected. Laparotomy with splenectomy remains the most accurate staging method in Hodgkin's disease and non-Hodgkin's lymphomas.

Abdominal Neoplasms↗
PubMed1989

[The unusually favorable prognosis of multiple primary bronchial carcinoma--the consequence of natural killer cell elevation and increased interleukin 2 receptor expression?].

It is reported on a 65-years-old man with the metachronous type of multiple primary bronchogenic carcinoma: initial peripheral adenocarcinoma (RUL) was observed; after 7 years developed left central squamous cell carcinoma; within 5 following years no evidence for relapse. The only remaining sign of malignant disease seems to be the increase of copper-level measured in the patients serum. The elevated quantity of natural-killer-cells (CD 16) and the high-grade Interleukin-2-receptor-expression (CD 25) obtained in our patient are discussed as indicators of pathophysiological processes which could possibly lead to the favourable prognosis of this case.

Adenocarcinoma↗
PubMed1988

[Disorders in the contact phase system of blood coagulation as a cause of increased partial thromboplastin time].

Deficiency conditions in the contact phase system of the blood coagulation belong to the rare hereditary defects. Clinically, there is as a rule no inclination to haemorrhage but an increased risk of thrombosis. Therefore, the diagnosis is frequently made on the basis of incidental findings within the framework of routine examinations. Indicating sign is a greatly prolonged partial thromboplastin time (PTT) without clinical signs of haemorrhage. 3 patients with factor XII deficiency are presented and the diagnostic method in prolonged PTT is explained.

Blood Coagulation Tests↗
PubMed1988

[Primary extranodular non-Hodgkin's lymphomas--observations on etiopathogenesis, histology and prognosis].

The total non-Hodgkin's lymphoma-population treated between 1978 and 1986 by means of radiotherapy or combined chemo/radiotherapy was analysed as to primary extranodular manifestation. 39 cases, 16 women and 23 men, were observed (stage IE 12, stage IIE 22 and stage IIIE 5). Immunoblastic (10), lymphoblastic (9) and centroblastic (6) lymphomas are the most frequent with respect to histology. Gastroenteron (16) and otorhinolaryngological region (13) are in the lead with regard to localisation. 5-year-survival-rates are determined in dependence on clinical stage: IE 65.8%, IIE 39.2% (low, connected with the proportion of high-malignant histology) and IIIE 25.0%. The 5-year-survival-rate of primary gastrointestinal manifestation amounted to 51.5%. With respect to aetiopathogenesis of primary extranodular lymphomas gut-, mucosa- and bronchial-associated lymphoid tissue, aberrant lymph-nodes and the influence of viral- and immunologic factors seem to be important.

Adult↗
PubMed1988

[Hodgkin's disease--immunological aspects].

The significance of immunological aspects in lymphogranulomatosis for the pathophysiological understanding of the disease was confirmed recently. Moreover, immunologic knowledge increasingly influences diagnosis, prognosis and treatment of Hodgkin's disease. In this survey cell-markers and cell-function of subpopulations of cells, participating in the disease are described. The origin of Hodgkin's- and Reed-Sternberg-cells as well as the aetiopathogenesis of the disease are discussed.

Antigens, Differentiation↗
PubMed1988

[Hodgkin and Sternberg-Reed cells--cell origin, cell marker, cell function].

The controversy in literature with regard to the origin of Hodgkin's and Reed-Sternberg cells persists, however only two conceptions seem to be plausible at present: the first is based on the relation to histiocytic elements, the second postulates lymphocytic precursors. The significance of surface-markers of these malignant cells in cryostat-sections and in cell-cultures and the relevance of their functional properties are discussed with respect to pathophysiology, clinical appearance, diagnosis and prognosis of Hodgkin's disease. The authors present two tendencies in the classification of malignant lymphomas based on the present knowledge achieved especially by monoclonal antibodies: the first includes aspects of integration between non Hodgkin's lymphomas and Hodgkin's disease, illustrated by the Ki-1-lymphoma, the second is related to separation of entities of the group of Hodgkin's lymphomas (for example the nodular paragranuloma). The aetiopathogenesis of Hodgkin's disease is considered as a causal trinity of virus infection, genetic determination and immunologic predisposition.

Biomarkers, Tumor↗
PubMed1987

[Epidemiology of Hodgkin's disease from the pathophysiologic viewpoint--review].

The aetiology of Hodgkin's disease remains unclear, however epidemiological characteristics have led to directive conceptions. The description of the rare familiar appearance of lymphogranulomatosis among other things by two cases of our own population and the presentation of milieu factors influencing incidence and prevalence rates give a extensive basis of discussion to develop pathophysiological ideas and to prove it by clinical, pathological, genetical and immunological knowledge. Genetical determination by an autosomal-dominant allele, with incomplete penetrance, predisposing insufficiency of immune suppression and disease inducing virus infection seems less to be three competing aetiologic systems; they rather form a causing trinity, which internal connexions we are at present not able to understand.

Cross-Sectional Studies↗
PubMed1987

[Prognosis of non-Hodgkin's lymphomas in the Dresden district with special reference to combined radio-/chemotherapy].

The total population affected with non-Hodgkin's lymphoma and treated by means of radiotherapy or combined radio-chemotherapy between 1960 and 1985 at the Medical Academy Dresden was analysed as to prognosis. 247 patients were classified according to the previous German scheme, 79 were subdivided on the basis of the recommendations laid down in the Kiel classification. The remission rates and survival curves achieved will stand out the comparison with international literature (remission rates of the low malignancy group amounted to 85.3 p.c. and those of the high malignancy group to 80.0 p.c.; the 5-years survival rates of the low malignancy group amounted to 61.9 p.c. and those of the high malignancy group to 41.7 p.c.). The influence of histology, clinical stage and involvement of organs is discussed on the basis of our results and informations obtained in literature. Our analysis confirms the high importance which must be attached to a common radiologic-internal outpatient-department for co-ordinating the diagnostic and therapeutical programme.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

[Active principles of plant origin: a tool for studying membrane receptors].

Ever since ancient times, considerable interest has been shown in plants for therapeutic use. Nowadays, however, studies of plant extracts are no longer based on empiricism; they provide great support to fundamental research, especially for a better understanding of the mediator/receptor couples. This applies to the study of cholinergic (atropine, muscarine, etc.), adrenergic (yohimbine, rauwolscine, etc.), dopaminergic (apomorphine, bromocriptine, etc.), purinergic (caffeine, theophylline, etc.), opiate (morphine), GABA (strychnine, muscimol, bicuculline, etc.), cardiac glycosides (gitaloxin, digitoxin) and PAF-acether receptors (ginkgolides from Ginkgo biloba).

Cell Membrane↗
PubMed1986

A new potent inhibitor of lipid peroxidation in vitro and in vivo, the hepatoprotective drug anisyldithiolthione.

The drug anisyldithiolthione (ADT) acted as a good inhibitor of lipid peroxidation induced in rat liver microsomes either chemically by FeSO4 and reducing agents (cysteine or ascorbate) or enzymatically by NADPH and CC14. ADT was found as potent as propylgallate with IC50 around 2 microM and much more potent than vitamin E and levamisole. ADT was also found as a good inhibitor of ethane exhalation by rats treated by CCI4 (ID50 approximately 5mg per kg) and by mice intoxicated by acetaminophen (ID50 approximately 0.7 mg per kg). At doses as low as 5 mg per kg it completely suppressed ethane exhalation by acetaminophen-intoxicated mice and also protected them very efficiently against mortality caused by acetaminophen overdose. The inhibitory effect of ADT toward lipid peroxidation seems to be linked to the presence of its dithiolthione function.

Acetaminophen↗