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Biomedical subjects

B Larsen

Publications and source records attributed to B Larsen.

At least 199 records · Page 11Linked to original sources
PubMed1982

Effect of estrogen treatment on the genital tract flora of postmenopausal women.

The anaerobic and aerobic flora of the vagina was identified in 79 postmenopausal women, 33 of whom received estrogen replacement. Four anaerobic species were more prevalent among estrogen-treated women than among untreated women, whereas 2 anaerobic species were less prevalent in the treated group. The types of organisms isolated from both groups are similar and all organisms isolated were considered usual inhabitants of the genital tract.

Aged↗
PubMed1981

Focal hyperemia followed by spreading oligemia and impaired activation of rCBF in classic migraine.

Regional cerebral blood flow (rCBF) was measured in 254 areas of a hemisphere with the xenon 133 intraarterial injection method. Six cases of classic migraine were followed from the normal state into the prodromal phase, and in 3 cases further into the headache phase. One patient with common migraine was similarly followed during his only classic attack. The attacks were initiated by focal hyperemia in 3 patients. During prodromes all patients displayed occipitoparietal rCBF reduction (oligemia), but in only 1 case did the reduction approach critical values. Oligemia gradually spread anteriorly in the course of 15 to 45 minutes. In 4 patients a global oligemia was observed. In 4 patients severe headache was present concomitantly with oligemia and with no sign of hyperemia or nonhomogeneous brain perfusion. The normal rCBF increase during cortical activity (hand movement, speech, and similar activities) was impaired in 6 patients. The results indicate that the vasospastic model of the migraine attack is too simplistic.

Adolescent↗
PubMed1981

Effects of basic proteins on spontaneous rosette formation between human lymphocytes and xenogeneic erythrocytes.

Two basic proteins (methylated human serum albumin, MHSA, and protamine sulphate, PS) were investigated for their modulatory capacities on a panel of human lymphocyte surface markers. MHSA and PS enhanced the spontaneous rosettes with mouse, sheep and horse erythrocytes, but did not affect the number of rosettes with zymosan particles coated with human complement, or with sheep erythrocytes sensitized with rabbit anti-sheep IgG antibody. Whereas the standard sheep (E) rosette test was not influenced by the negatively charged glycoprotein ceruloplasmin, this compound could, however, abolish the MHSA- and PS-induced enhancements of the number of sheep rosettes. By double marker studies it was furthermore demonstrated that a subset of B cells was induced by MHSA to form E rosettes, and that the same agent increased the number of B cells forming mouse rosettes, so that nearly all B cells were made positive for this marker.

Adult↗
PubMed1981

Corticosteroids decrease the expression of beta 2-microglobulin and histocompatibility antigens on human peripheral blood lymphocytes in vitro.

The in vitro effect of two different glucocorticoids (prednisolone and dexamethasone) on the expression of beta 2-microglobulin and HLA-A-A, -B and -C-antigens on the surface of cultured lymphocytes was measured by quantitative immunofluorescence (flow cytofluorometry) and by a radioimmunoassay. Both antigens were found to be decreased, dexamethasone typically in a concentration of 10-6 mol/l causing a decrease in surface beta 2-microglobulin of 15% after an incubation period of 24 hr. The expression of two other lymphocyte surface antigens, Igm and Thy antigens, measured in parallel with beta 2-microglobulin and HLA antigens, was not affected by the same culture conditions. The steroid effect was not due to masking of the affected antigens, but was completely abolished by inhibition of protein synthesis.

Adult↗
PubMed1980

Mass spectrometry of chlorambucil, its degradation products, and its metabolite in biological samples.

A sensitive and specific method for the determination of chlorambucil and its metabolite in biological fluids is reported. The method is based on selected-ion monitoring detection following simple extraction of the parent compound, its metabolite, and an internal standard (chlorambucil-d8) from plasma and urine samples. The precision (reproducibility) of the method was 94.3 +/- 1.3% with 200 ng of chlorambucil added to 1 ml of plasma. Chlorambucil degradation or alkylation of plasma proteins was minimal with plasma incubated at 24 degrees for 4 hr. However, chlorambucil recovery decreased to 56% after plasma incubation at 37 degrees for 4 hr. Three chlorambucil degradation products in ethyl acetate solution were found, and their structures were studied by mass spectrometry.

Animals↗
PubMed1980

Vaginal microbial flora: practical and theoretic relevance.

The bacterial flora of the female reproductive tract is a focal point for the study of infectious disease in obstetrics and gynecology, as it is recognized that many pelvic infections involve bacteria resident on the cervical-vaginal epithelium. The vaginal flora contains a large variety of bacterial species, including aerobic and anaerobic organisms, as revealed by modern microbiologic methods. Recent studies have indicated that certain organisms commonly involved in pelvic infections, particularly those following genital tract surgery, name Escherichia coli and Bacteroides fragilis, appear to be underrepresented in relationship to the infectious complications they cause. A possible explanation of this phenomenon has been suggested based on the finding that traumatic events in the reproductive tract, including parturition, surgery, and invasive malignancy, result in increased colonization by organisms commonly involved in pelvic infections. Other changes in the flora related to the host's hormonal milieu were identified and are generally less profound than those related to trauma. We have reviewed some of the newer aspects of our understanding of the genital flora, such as quantitation of the vaginal flora, which should continue to improve our understanding of the role of the genital flora in disease states.

Adolescent↗