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Biomedical subjects

M Martin

Publications and source records attributed to M Martin.

At least 901 records · Page 50Linked to original sources
PubMed1980

Effect of captan on DNA synthesis in the liver and testes of rats.

Rats were fed a diet containing 0.3% (w/w) captan for 2, 4 and 12 weeks and compared with controls, and with rats fed 0.02% (w/w) N-2-acetylaminofluorene (AAF). Cell loss was evaluated from the drop of previously [14C] labeled DNA and DNA synthesis was expressed as fractional incorporation of [3H] dThd into hepatic and testicular DNA. The feeding of AAF for 12 weeks produced in the liver a cell loss and a stimulation of DNA synthesis (+ 348%); in the testes, a cell loss but an inhibition of DNA synthesis (- 84%) occurred. The continuous feeding of captan produced no cytotoxic effect on the liver but increased hepatic DNA synthesis between 2 and 4 weeks of diet (+ 100%). Then, the synthesis induction seemed to reach a plateau until 12 weeks. The captan diet did not provoke any cytotoxic effect on testes until 4 weeks of feeding. At 12 weeks, some loss of testicular DNA and of [14C] labeling indicated a toxic effect of captan. The testicular DNA synthesis was clearly inhibited by captan diet at 4 weeks (- 22%), and the inhibition increased at 12 weeks (- 27%). Experiments done at a higher level of captan (1.5% in the diet) showed that the effect on DNA synthesis in liver and testes was dose-related.

2-Acetylaminofluorene↗
PubMed1980

Characterization of corticosterone-induced protein synthesis in hippocampal slices.

Corticosterone significantly increases the incorporation of [3H]leucine into specific cytosol protein(s) isolated from in vitro hippocampal slices prepared from adult male albino rats. The present study showed that in slices coincubated with glucocorticoid plus a protein synthesis inhibitor (1 mM-cycloheximide), no such enhancement of amino acid incorporation was observed, suggesting that the hormone acts in the hippocampus to increase de novo protein synthesis. Further experiments demonstrated that the steroid-induced protein synthesis was first detectable (+ 5.7%) following a 30-min exposure of slices to corticosterone; slices incubated for 1 or 2 h both showed a 12% increase in synthesis of the affected protein(s) when compared with controls. In an attempt to determine whether the glucocorticoid alteration of protein metabolism was receptor-mediated, hippocampal slices were also incubated with 10 nM-progesterone, a steroid known to compete for corticosterone binding to its cytosol receptor. Progesterone alone, which does not translocate cytoplasmic receptors to the nucleus, did not alter hippocampal protein metabolism and effectively blocked the induction by corticosterone of the 54K protein(s). These studies provide evidence that in the rat hippocampus corticosterone interacts with high-affinity steroid receptors to regulate the synthesis of specific protein(s).

Animals↗
PubMed1980

Ultrasonic Doppler measurement of systolic pressure in the quantitative evaluation of chronic arterial occlusions.

This study deals with a method of performing ultrasonic Doppler measurements in patients with chronic arterial occlusions. Ankle systolic pressures distal to occlusions (as diagnosed by angiography) were sampled and the mean values calculated. Standard deviations of the method were validated. The ultrasonic Doppler method for measurement of systolic pressure is a valuable new tool for assessing peripheral arterial occlusions. Especially in geriatric patients, with their high rate of vascular problems and the lingering danger of heel necrosis in the course of longstanding immobility, this method supplies the attending physician with quantitative data as a basis for diagnosis, prophylaxis, and treatment.

Aged↗
PubMed1980

Absorption and fate of canthaxanthin in chicken.

Male Hubbard chickens were fed on a diet supplemented with canthaxanthin. The carotenoid was chemically unmodified during its absorption of distribution. Pigment was preferentially stored in the skin of legs. The percent distribution of carotenoid in the different organs did not vary with the administered dose or during the treatment. Digestibility, expressed as the ratio absorbed: ingested pigment, was maximal in the first day, and then decreased. Digestibility was dependent on the animal body weight.

Animals↗
PubMed1980

Properties of human pluripotent hemopoietic progenitors.

Human pluripotent hemopoietic progenitors (CFU-GEMM) from mixed colonies when cultured in methylcellulose or agar in the presence of erythropoietin and PHA-LCM. The observed frequency is low and varies for different individuals between 0 and 4 mixed colonies/O5 mononuclear cells. CFU-GEMM do not adhere to glass or plastic surfaces; their density is less than 1.077 g/ml, and their sedimentation velocity profile peaks at 4.5 mm/h. They do not form rosettes with sheep red blood cells. These physical parameters can be used preparatively to enrich for CFU-GEMM to facilitate assessment of their biological properties such as cycle state analysis and measurement of self-renewal capacity. Preliminary information suggests that some CFU-GEMM are capable of self-replication. Cycle state data are available for a larger number of patients with various clinical conditions. CFU-GEMM were found to be quiescent under steady-state conditions. They proliferate actively during bone marrow regeneration and in stem cell disorders like Polycythemia rubra vera or CML. These changes in cycle state activity were not reflected in numerical alterations of CFU-GEMM. It was thus concluded that the assay may be used more meaningfully to assess biological properties of human pluripotent progenitors rather than their frequency.

Cell Adhesion↗
PubMed1980

[Hormonal control of vitellogenin synthesis in the Amphipoda Crustacea Orchestia gammarella (Pallas)].

The presence of a vitellogenin stimulating ovarian hormone (VSOH) in Orchestia gammarella has been demonstrated by gonadectomy and ovary grafting. Vitellogenin synthesis is not affected by molting hormone injection; it decreases after Y-organ (molting gland) cauterization. Studies in progress seem to indicate that the destruction of the median area of the protocerebrum is followed by a decrease of this synthesis.

Animals↗
PubMed1979

[Lung cancer with elevated amylase activity. One observation with study of amylase's isoenzymes (author's transl)].

Amylase is composed by two isoenzymes groups: pancreatic or salivary type. This last part can be increased in many diseases. A case of lung cancer with elevated amylase activity in blood, urine and pleural fluid is reported in a 74-year-old man. This increase was due to salivary type isoamylases with an unusual component which disappeared by neuraminidase treatment. The significance and the origin of this hyperamylasemia with non pancreatic cancer are discussed.

Adenocarcinoma↗
PubMed1979

Neutrophil enzyme activities in rheumatoid inflammation.

This study analyzed the neutrophils and sera of patients with rheumatoid arthritis and of normal controls. No significant differences were found in the activities of the granular enzymes beta-glucuronidase and lysozyme or the cytoplasmic enzyme lactic dehydrogenase (LDH). Normal neutrophils were found to release significant (P less than 0.05) amounts of the granular enzymes, but not of LDH in response to immunoglobulin G aggregates. There was no difference in the percent release exhibited by rheumatoid versus control neutrophils. Studies delineating the effects of rheumatoid factor sera and normal sera on aggregate-induced enzyme release revealed a significant negative correlation between the amount of rheumatoid factor in the sera and the percent release of beta-glucuronidase and lysozyme but not of LDH. These studies thus demonstrate no abnormalities in rheumatoid neutrophil or rheumatoid serum enzyme activities or in neutrophil response to immunoglobulin G aggregates. They suggest, however, that rheumatoid factor may partially inhibit the release of lysosomal enzymes, thus suppressing this important component of the rheumatoid inflammatory process.

Arthritis, Rheumatoid↗
PubMed1979

A new assay for the evaluation of antiplatelet antibody in idiopathic thrombocytopenic purpura.

A new approach to the study of antiplatelet antibodies is described. Purified IgG from sera or from the culture of splenic ells was radiolabeled with 125I. Incubation of radiolabeled splenic IgG from ITP patients showed significantly greater binding to target platelets when compared to control IgG samples; conversely, the binding to target platelets of 125I-labeled serum IgG from ITP patients did not differ from controls. In each of the six instances when the binding of splenic and serum IgG from the same ITP patients was compared, the splenic samples contained a much higher concentration of platelet-specific IgG. This suggests that intrasplenic platelets in ITP patients are exposed in vivo to high concentrations of antiplatelet antibody and may explain, in part, the importance of the spleen in platelet destruction in this disease. This assay should prove useful in the further study of immune thrombocytopenia.

Antibodies↗
PubMed1979

Negative recency and measurement of primary memory.

The technique of Waugh & Norman (1965) is widely used in measuring the capacity of primary memory. Watkins (1974) has proposed a modification of the technique which takes into account registration failure. A further modification is proposed which takes into account findings of negative recency in delayed recall.

Humans↗
PubMed1979

Dementia paralytica: deterioration from communicating hydrocephalus.

Five patients suffering from dementia paralytica who failed to improve or deteriorated after one or several high dosage courses of penicillin, had pneumoencephalographic patterns suggesting communicating hydrocephalus. Measurements of the ventricular index, ratio of cella media to width of the temporal horn, and the callosal angle differed from that in seven cases of dementia paralytica with associated cerebral atrophy. An isotope cisternogram in three cases with communicating hydrocephalus further confirmed a blockage of the cerebrospinal fluid (CSF) at the parasagittal subarachnoid space. Three patients exhibited the full syndrome of gait apraxia, incontinence, and pyramidal tract signs associated with a severe degree of dementia. Shunting of the CSF in three cases was followed by immediate improvement in two, one in a longlasting way. No active parenchymal inflammation was observed in any of three brain biopsy samples taken during surgery, except for leptomeningeal fibrosis in one. Chronic leptomeningitis in dementia paralytica may impair subarachnoid CSF absorption with subsequent communicating hydrocephalus. Progression or inadequate responses after therapeutic dose of penicillin in dementia paralytica should prompt investigation for this complication as an alternative, effective treatment could be offered.

Adult↗
PubMed1979

[Factors favouring necrosis after curietherapy for oral cavity epitheliomas (author's transl)].

The authors studied the factors which favour necrosis after curietherapy, in a series of 82 patients with epithelioma of the oral cavity and a previous series of 280 cases. The principal factor is the size of the tumor. The other factors (macroscopic appearance, dose, quantity of radioactive material, degree of inhomogeneity, distance between the lines, association with external irradiation), are or only moderate importance, as shown by the variations observed, though they are difficult to evaluate in an exact manner, partly for methodological reasons. The frequency of necrosis of bone tissue is directly relaxed to the number of radioactive lines in contact with the maxilla. Alcohol and tabacco abuse have a definite influence but this cannot be calculated. In conclusion, therefore, it would appear possible to reduce the frequency of necrotic lesions by reducing the tumoral size by curietherapy, by applying no more than 2 lines in contact with the mandible for bony necrotic lesions, and by stopping the abuse of alcohol and tobacco.

Humans↗
PubMed1979

[Doppler ultrasonic measurement for diagnosing carotid occlusions and stenoses (author's transl)].

Doppler ultrasonic measurements were performed in 74 patients suffering from cerebrovascular disorders. Flow direction was determined in the supratrochlear artery by using a directional Doppler sonographic instrument according to the method of Keller et al. 15 patients presented, unilateral or bilateral, with a flow reversal (i.e. direction of flow into the orbita via supratrochlear artery). In 8 of these patients carotis or aoitic arch angiographies were performed and in 4 cases necropsy reports were available. In all instances where flow reversal occurred severe carotid stenoses or occlusions were demonstrable. Thus 9 internal carotid occlusions, 1 common carotid occlusion, and 3 severe internal carotid stenoses were proved. One internal carotid occlusion and 3 internal carotid stenoses were operated on. Check-up sonograms after endarterectomy of carotid occlusions or stenoses showed a normal antegrade flow thus demonstrating patency of the carotid vessels. Obviously, supratrochlear flow reversal as measured by ultrasonic technique signals ipsilateral carotid vessel occlusion or stenoses. Furthermore, the method seems to be a reliable means for controlling carotid endarterectomy.

Aged↗
PubMed1979

[Heel necrosis: a complication of geriatric diseases (author's transl)].

12 heel necroses were seen in a group of 596 geriatric patients. The patients average age was 73 years. 3 tentative causes for the development of heel necrosis were investigated. 1. Imobility, 2. Arterial occlusive disease, and 3. Diabetes. Immobility was demonstrable in all cases. Additionally, arterial occlusions of the leg were present in 7 and diabetes in 6 patients. The percentage of arterial occlusion and diabetes was significantly higher in the heel necrosis group than in the overall hospital cohort. The two diseases can be looked upon as risk factors for the development of heel necrosis.

Age Factors↗