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Biomedical subjects

B Winblad

Publications and source records attributed to B Winblad.

At least 523 records · Page 29Linked to original sources
PubMed1978

Pathogenicity in mice of strains of Candida albicans with different in vitro sensitivity to 5-fluorocytosine.

The pathogenicity in mice of 7 strains of Candida albicans with different in vitro susceptibility to 5-fluorocytosine (5-FC) was investigated. Resistant strains were not less virulent than susceptible strains. This is contradictory to findings reported for candida strains resistant to polyene antibiotics, which were less pathogenic than susceptible strains. The implications of these findings are discussed.

Animals↗
PubMed1977

Growth pattern and cell division in Neisseria gonorrhoeae.

The gram-negative coccus Neisseria gonorrhoeae was found to grow regularly in at least two dimensions. Growth proceeded at a linear rate sequentially in each dimension. Growth in the second dimension (former width) was initiated slightly before the pole-division plane distance equalled the cell width. Penicillin treatment localized presumptive growth zones to the existing septum region. It was suggested that new growth zones were always formed perpendicular to the longitudinal axis created in the incipient daughter cells of a dividing coccus. Neither penicillin nor nalidixic acid induced filaments of N. gonorrhoeae. Such structures could nevertheless be formed in the rod-shaped species Neisseria elongata. N. gonorrhoeae divides by septation; however, complete septal structures with separated cytoplasms were rather infrequent. It is proposed that N. gonorrhoeae be regarded as a short rod which always extends parallel to the actual longitudinal axis and which never undergoes a rod-sphere-rod transition.

Cell Division↗
PubMed1977

Scanning electron microscopy of surface changes on dispersed pancreatic beta-cells following stimulation of insulin release.

The surface structure of isolated, viable beta-cells was studied by scanning electron microscopy. Suspensions of islet cells wuse. Cells incubated with and without D-glucose were fixed while in suspension, filtered onto Nucleopore filters and prepared for scanning electron microscopy by the critical point drying procedure. After incubation in glucose-free medium the cells were spherical with surface blebs and occasional small pits. Cells stimulated with 20 mM D-glucose and 0.1 mM 3-isobutyl-1-methyl-xanthine exhibited a two-fold increase in the number of blebs and in insulin release. The increased number of blebs was still seen in a Ca++ deficient medium, and may, therefore, not necessarily reflect an insulin extrusion phenomenon. It is concluded that D-glucose induces alternations of the surface morphology in isolated beta-cells in suspension.

Animals↗
PubMed1977

Monoamine oxidase activity in gamma-irradiated rat brains.

The short-term effect of gamma-irradiation (single dose, 100 Gy = 10 000 rad) on tth monoamine oxidase activity in the rat brain was investigated. In contrast to other investigations virtually no changes in MAO-activity were found.

Animals↗
PubMed1976

Diagnostic aspects of bladder angiography in urinary bladder tuberculosis.

Histopathological and angiographic findings were correlated in 6 cases of tuberculosis of the urinary bladder. The number of vessels was only slightly increased in the initial and fibrotic stages, whereas hypervascularization was observed in the exudative and productive stages. Otherwise the angiographic changes were nonspecific. Thus it was not possible to distinguish tuberculous cystitis from cystitis of other genesis, and in some instances from tumours of the urinary bladder either.

Angiography↗
PubMed1976

Vascular changes in the urinary bladder wall after irradiation (an experimental study in rabbits with angiography and scanning electron microscopy of vascular casts).

Seven adult rabbits were used to study radiation-induced vascular changes in the urinary bladder by angiography and scanning electron microscopy of vascular casts. The angiographic studies, in which a magnification techniques was used, revealed a state of hypervascularization in the irradiated area of the bladder. With the angiographic method, however, it was not possible to visualize specific radiation-induced vascular changes within the irradiated area of the urinary bladder. Scanning electron microscopy of vascular casts made possible a detailed study of finer vessels in which typical radiation changes, teleangiectases, could be demonstrated.

Angiography↗
PubMed1976

Proteolytic activity of Streptococcus mutans (GS-5).

The potential proteolytic ability of cariogenic streptococci was assessed in a strain of Streptococcus mutans (GS-5). Blood-borne S. mutans from rats infected by mouth with GS-5 were cultured, and sterile rat tail tendons were placed on these cultured bacterial colonies. The collagenolytic ability of these organisms was examined under the scanning electron microscope and by testing for reduced tensile strength of the collagen fibers. These experiments showed that GS-5 cariogenic streptococcus can be conditioned to produce significant collagenolytic activity.

Animals↗
PubMed1976

Determination of monoamine and monoamine metabolites in the human brain: post mortem studies in a group of suicides and in a control group.

Different nuclei and regions of the brain from patients who had committed suicide and from controls were analysed for their content of monoamine and monoamine metabolites. There was a post mortem breakdown of 5-hydroxyindoleacetic acid (5-HIAA) which could be correlated to the time elapsed between the occurrence of death and autopsy. Homovanillic acid (HVA) and the monoamines did not decrease post mortem during the time observed (6-148 hours). There was no significant correlation between age and chemical variables in this investigation. There were no significant group differences between suicides and controls concerning dopamine, noradrenaline, 5-hydroxytryptamine, and HVA, 5-HIAA levels were significantly lower in the suicide group in six out of eight parts of the brain investigated. It was, however, also demonstrated that there was a longer time elapse between the occurrence of death and autopsy in the suicide group. The suicides came on average 48 hours later to autopsy than the controls. As there was a post mortem decrease of 5-HIAA, this time variable had to be kept constant when group differences were analysed. When the influence of this time variable was eliminated there were no longer any differences between suicides and controls. According to this investigation, there seem to be no differences in levels of monoamines and their metabolites between suicides and controls.

Adult↗
PubMed1976

Scanning electron microscopy of Neisseria gonorrhoeae. Age-induced changes in macro- and microstructure of virulent and avirulent colonies.

Virulent and avirulent gonococcal colonies were studied in the scanning electron microscope. Cells in virulent, in contrast to avirulent, colonies were found to be connected by numerous strands. After longer incubation periods, type 2 colonies segregated out regions of cells virtually lacking these strands. Cells within these areas probably represent avirulent segregants. The microstructure of individual colonies revealed no topographical differences. In certain colonies large smooth spherical cells were seen, probably representing wall-deficient gonococcal variants.

Microscopy, Electron, Scanning↗
PubMed1976

Late effects on rabbit brain morphology and monoamine metabolites produced by 60C0-irradiation.

Twenty-three rabbits were exposed with 60Co irradiation over the skull. Nineteen of the animals received 29.6 Gy over the right hemisphere and 4 animals received 20 Gy over both hemispheres. Six months after the exposure the cncentrations of 5-hydroxyindolacetic acid (5-HIAA) and homovanillic acid (HVA) in seven different brain regions were assayed. No significant differences in the levels of these monoamine metabolites as compared to nonirradiated control animals were found. In contrast to discrete biochemical changes, a relatively marked parenchymal destruction was demonstrated by means of light microscopy, microangiography and scanning electron microscopy of the vessels, which exhibited telangiectases, fibrinoid necroses and thrombosis due to the late effects of irradiation.

Animals↗