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Biomedical subjects

S Persson

Publications and source records attributed to S Persson.

At least 91 records · Page 5Linked to original sources
PubMed1989

The capacity of subgingival microbiotas to produce volatile sulfur compounds in human serum.

Hydrogen sulfide is formed by the subgingival microbiotas of periodontal pockets. The capacity of these microbiotas to form various volatile sulfur compounds in human serum was studied. Bacterial samples from nine deep periodontal pockets were incubated for 7 days in human serum and the amounts of volatile sulfur compounds and the degradation of serum proteins were determined. Hydrogen sulfide was the predominant volatile sulfur compound, but also methyl mercaptan was formed in significant amounts. Only traces of dimethyl sulfide and dimethyl disulfide were detected. There was an extensive degradation of the serum proteins. In most of the reaction mixtures hydrogen sulfide reached highly toxic levels.

Bacteria↗
PubMed1989

Muscular adaptation of horses during intensive training and detraining.

Five horses were studied during a five-week regime of controlled intensive daily training on a high-speed treadmill followed by five weeks of detraining. Muscle biopsies were taken weekly from both the right and left gluteus muscle and from the sternocephalicus muscle before, and at the end of, the training and detraining periods. Histochemical and biochemical analyses of the sternocephalicus muscle showed no metabolic adaptation with either training or detraining. No significant differences were observed in any of the analysed parameters in the gluteus muscle between contralateral sites. Glycogen levels decreased by 10 to 15 per cent after one to two weeks of training, remained low during the training period and increased to pretraining levels after one week's cessation of training. Citrate synthase activity increased rapidly and was 27 per cent higher after one week and 42 per cent higher after five weeks of training. Lactate dehydrogenase activity decreased by 15 per cent during this period. The changes seen in these enzyme levels persisted during the detraining period. No alterations were seen in fibre type composition but type IIA fibre areas decreased by 19 per cent after five weeks training and capillary density increased by 17 per cent. It is concluded that a period of intensive training will rapidly increase the oxidative capacity and the capillary density in an actively working muscle, and that these metabolic adaptations are well maintained during a subsequent period of detraining.

Animals↗
PubMed1989

Activity of polymorphonuclear leukocytes in the presence of sulfide.

Polymorphonuclear leukocytes (PMN) isolated from human blood were exposed to various levels of hydrogen sulfide. The effect on respiratory burst, myeloperoxidase activity, and capacity to phagocytose and kill bacteria were studied. A 1-h exposure of the PMN to 1 mM sulfide did not decrease their myeloperoxidase activity or their capacity to initiate a respiratory burst. Actually the products of the respiratory burst rapidly oxidized sulfide. The phagocytosis and killing of bacteria in the presence of 1 mM sulfide was only decreased to a minor extent. Myeloperoxidase in cell extract was, however, almost completely inhibited by 1 microM sulfide. These results indicate that hydrogen sulfide does not easily permeate PMN. PMN may be able to function in infected sites with high sulfide levels such as in the gingival pockets of periodontal disease. In the oxygenated areas of these sites the PMN may actually help in the detoxification of sulfide.

Blood Bactericidal Activity↗
PubMed1989

Studies on blood viscosity during the menstrual cycle and in the postmenopausal period in healthy women.

Blood viscosity was measured in 14 healthy, menstruating women, aged 17-51 years and in 10 healthy, postmenopausal women, aged 55-64 years. The fertile women were studied once a week during a normal menstrual cycle and the postmenopausal women twice with an interval of 2 weeks. Blood viscosity was measured at natural hematocrit as well as at hematocrit 45%. In the postmenopausal women no changes in blood viscosity were found. In the fertile women, blood viscosity at hematocrit 45% was lowest at the start of the menstrual bleeding and increased to a peak at day 7 (p less than 0.01), with a similar pattern when measured at natural hematocrit. Plasma viscosity also had its lowest value at the onset of menstrual bleeding, increasing to a maximum at day 21. Changes in plasma triglycerides, but not in fibrinogen or cholesterol, seemed to contribute to this increase. Plasma factors only partly explained the variations in blood viscosity, and changes in red cell properties were also found to be of importance. The clinical significance of these rheological changes remains to be established, but at least theoretically there may be an increased risk for thromboembolism, e.g. at surgery, during days 5-15 of the cycle. In studies on blood flow and rheological conditions in fertile women, it seems advisable to standardize for time in the menstrual cycle.

Adult↗
PubMed1988

Alveolar soft part sarcoma. An immunohistochemical, cytologic and electron-microscopic study and a quantitative DNA analysis.

The type, differentiation and histogenesis of the tumor cells of alveolar soft part sarcoma (ASPS) have been analyzed in a series of ten cases by a light-microscopic, ultrastructural, immunohistochemical and cytologic investigation and quantitative DNA analysis. Four tumors deviated from ordinary ASPS: three were wholly or partly of the so-called pleomorphic variant of ASPS and a fourth tumor showed calcifications of the psammoma body type. The ultrastructural findings and immunohistochemical demonstration of desmin supported the hypothesis of a rhabdomyomatous differentiation and gave no support to epithelial (negative immunoreactions for cytokeratins, epithelial membrane antigen, HMFG-1 and -2, tissue polypeptide antigen (TPA] or neuroectodermal (negative for S-100 protein, glial fibrillary acidic protein, neurofilaments) differentiation. The negative immunoreactions for vimentin and myoglobin and the positive reaction for neuron specific enolase (NSE) do not exclude a rhabdomyomatous differentiation since in rhabdomyosarcomas the undifferentiated rhabdomyoblasts generally contain vimentin and the differentiated tumor cells contain myoglobin and rhabdomyosarcoma has previously been reported as being positive for NSE. The production of external lamina material peripherally in the tumor cell nests and around vessels in the vascular septa was demonstrated both ultrastructurally and by immunohistochemistry using antibodies against collagen IV and laminin. The cytologic appearance in smears obtained by fine-needle aspiration from a case of the pleomorphic variant showed some resemblance to that of a carcinoma. The seven tumors with an ordinary cell appearance were found to show a diploid DNA-distribution at a quantitative analysis performed on paraffin sections, while the three tumors wholly or partly of the pleomorphic type showed an additional tetraploid peak.

Adolescent↗
PubMed1988

Catalase inhibition by sulfide and hydrogen peroxide-induced mutagenicity in Salmonella typhimurium strain TA102.

The lethal and mutagenic effects of hydrogen peroxide were studied in exponentially growing cultures of Salmonella typhimurium strain TA102. Exposure of the cultures to non-lethal levels of sodium sulfide significantly increased the lethality and mutagenicity of hydrogen peroxide. The catalase activity was decreased in cells exposed to sodium sulfide, but there were no changes in the cellular levels of superoxide dismutase, glutathione reductase, or NADPH-dependent alkyl hydroperoxide reductase. Hydrogen peroxide-induced mutagenesis and killing of S. typhimurium strain TA102 in the presence of sulfide may in part be explained by an inactivation of catalase by sulfide.

Catalase↗
PubMed1988

Increased whole blood and plasma viscosity in patients with angina pectoris and "normal" coronary arteries.

Blood and plasma viscosity was measured in eight patients with typical effort-induced angina pectoris who did not have coronary artery stenosis at angiography. The same variables were studied in 14 patients with angina pectoris and verified coronary artery disease that in most cases was extensive. Both groups of patients had significantly higher viscosity values in whole blood, at natural hematocrit as well as standardized hematocrit (45%), than 25 healthy subjects serving as a reference group. Plasma viscosity was also significantly elevated in both patient groups. The patients without coronary artery stenosis had as high blood and plasma viscosity values as had the stenosis group. It is concluded that increased blood and plasma viscosity should be added to the list of pathological findings in patients with angina pectoris in the absence of organic coronary artery stenosis.

Aged↗
PubMed1988

Protein synthesis and quantitative morphology in thyroid tissue from hyperthyroid patients after preoperative treatment with antithyroid or beta-adrenergic antagonist drugs.

The rate of protein synthesis was measured in thyroid tissue obtained from three groups of patients undergoing thyroid surgery: group I (n = 18), hyperthyroid patients preoperatively treated with an antithyroid drug and T4; group II (n = 11), hyperthyroid patients preoperatively treated with a beta-adrenergic antagonist drug; and group III (n = 9), euthyroid patients operated on for multinodular goiter or adenoma. Quantitative morphology was studied in the resected thyroid tissue from the patients in groups I (n = 15) and II (n = 6) who had Graves' disease. While serum thyroid hormone levels became normal during preoperative treatment in group I, they remained elevated in the group II patients. The rate of protein synthesis was 2-fold higher in thyroid tissue from patients in group II than in those in groups I and III. A tendency toward an increased amount of epithelium and a reduced amount of colloid was found in thyroid tissue from patients in group II. There was a positive correlation between the rate of protein synthesis, and distribution of epithelium, and the epithelium to colloid ratio, respectively, in thyroid tissue. These results suggest that the thyroid gland of hyperthyroid patients remains hyperactive during treatment with beta-adrenergic antagonist drugs.

Adrenergic beta-Antagonists↗
PubMed1988

Epithelioid sarcoma. An electron-microscopic and immunohistochemical study.

The present report is a light- and electron-microscopic and immunohistochemical study of 7 cases of epithelioid sarcoma. Formalin-fixed and paraffin-embedded material and in one case ethanol-fixed material from the tumors as well as control tissues were used for the immunohistochemical analysis. A positive reaction for cytokeratins was observed in all 7 tumors when using 3 different polyclonal antibodies and 1 of 3 monoclonal antibodies. All tumors were positively stained with monoclonal antibodies against the epithelial membrane antigen (EMA) and all except one with monoclonal antibodies against the human milk fat globule (HMFG 1 and 2). In all tumors there was a positive reaction for actin and vimentin, using monoclonal antibodies. Ultrastructurally the tumor cells were characterized by pinocytic vesicles, cytoplasmic projections surrounding lumen-like slits, desmosome-like cell junctions and abundant thin and intermediate filaments, sometimes forming condensed bundles and tonofilament-like structures. In one case there were numerous dense cytoplasmic bodies, up to 800 nm in diameter, apparently formed by condensed intermediated filaments. The tumor cells of epithelioid sarcoma share morphologic features and immunohistochemical properties with epithelial cells, which however does not exclude the possibility of a mesenchymal origin.

Actins↗
PubMed1987

Incidence of deep vein thrombosis in bedridden non-surgical patients.

In order to detect deep vein thrombosis (DVT), 101 patients with acute medical or infectious disorders were examined with the 125I-fibrinogen uptake test. All patients were bedridden on admission and were scanned daily from the second to the eighth day. Thirteen patients developed a positive fibrinogen uptake test. Thus, if a positive test is interpreted as DVT, the incidence of DVT was 13% in our bedridden patients. Of the patients admitted because of heart disease or pneumonia 20% had DVT, but only 4% of those admitted with other diagnoses. Other clinical "risk factors" studied, could not identify patients who developed DVT.

Acute Disease↗
PubMed1986

Noninvasive findings in patients with hypertrophic and dilative cardiomyopathy: a combined echocardiographic and radionuclide angiographic study.

Fifteen patients with hypertrophic (HCM) and 15 with dilative cardiomyopathy (DCM) were examined with radionuclide angiography and M-mode echocardiography to evaluate the combination of two noninvasive methods for measuring left ventricular performance. The patients with HCM had delayed myocardial relaxation and rapid filling time with preserved peak rate of early ventricular filling. DCM patients, on the contrary, had low values of left ventricular systolic performance and low peak filling rate. Myocardial relaxation and rapid filling time, however, were short, indicating compensatory mechanisms in the failing ventricle improving rapid filling.

Adolescent↗
PubMed1986

Primary parathyroid hyperplasia of water-clear cell type. Transformation of water-clear cells into chief cells.

An exceptional case of water-clear cell hyperplasia (WCCH) of the parathyroid glands is presented. Parathyroid tissue was excised at three operations during a period of twenty years before the patient eventually became normocalcemic. Microscopic evaluation of the parathyroids from the first operation showed typical WCCH-findings. However, the parathyroid tissue excised at the last operation was composed of chief cells. There were calcifications and even bone formation. A pigment with the staining and electron-microscopic characteristics of lipofuscin was found in abundance. There were also a few oxyphils. This case shows that clear cells, originally derived from chief cells, can transform into chief cells again.

Adult↗
PubMed1986

Endocrinology of cardiac failure. Pathophysiologic aspects--hemodynamics.

The hemodynamic situation in congestive heart failure (CHF) is greatly influenced by compensatory mechanisms within the heart itself as well as released from the central nervous system and from the kidneys. These measures are intended to maintain the cardiac output at a level as beneficial as possible and to distribute the blood flow to regions with the largest metabolic demands. Thus the hemodynamic consequences of CHF are reflected in the central circulation as well as in the periphery. Within the heart the Frank-Starling mechanism, adrenergic stimulation causing increase of heart rate and contractility, and during the chronic course also myocardial hypertrophy are operating. The central nervous and peripheral adaptive measures include increased sympathetic outflow bringing about an increased vasomotor tone with augmentation of pre- and afterload, and activation of the renin-angiotensin-aldosterone system, where angiotensin II further augments vasoconstriction directly and through central nervous stimulation. This vasoconstriction may be counteracted by humoral factors with vasodilatory properties, such as dopamine, bradykinin, acetylcholine and the metabolic products adenosine and lactic acid. The exact role of these and the possible importance of the antidiuretic hormone, arginine vasopressin, the prostaglandin system and the recently discovered atriopeptin remains to be established. As the compensatory mechanisms may maintain a fairly satisfactory hemodynamic situation at rest, investigations should be performed not only at rest but also during exercise to get an over-all impression of the cardiac functional state.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1985

Energy metabolism in relation to skeletal muscle fibre properties during treadmill exercise.

The skeletal muscle metabolism of horses with a wide range of cardiocirculatory capacities was studied during a standardised near-maximal exercise test in relation to muscle fibre composition. Although the same amount of work was performed by all horses the amount of triglycerides and glycogen utilised and lactate accumulated differed widely. Both blood and muscle lactate accumulation were positively related to the amount of glycogen utilised. These factors were in turn positively associated with the percentage of Type IIB fibres and consequently negatively associated with the percentage of Type IIA fibres. The percentage of Type IIB fibres was negatively correlated to the activities of the oxidative enzymes citrate synthase and 3-hydroxyacyl-CoA-dehydrogenase and positively associated with the lactate dehydrogenase activity. The results indicate that the horses with a high proportion of Type IIB fibres had a lower muscle oxidative capacity and were, therefore, for energy production, more dependent upon glycolysis with subsequent lactate accumulation than horses which had a high proportion of Type IIA fibres. The different metabolic properties of the muscle fibre types indicate that the pattern of muscle fibre recruitment could have a significant effect on intramuscular substrate utilisation.

3-Hydroxyacyl CoA Dehydrogenases↗