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Biomedical subjects

B Steiner

Publications and source records attributed to B Steiner.

At least 163 records · Page 9Linked to original sources
PubMed1983

Effect of syphilitic rabbit sera taken at different periods after infection on treponemal motility, treponemal attachment to mammalian cells in vitro, and treponemal infection in rabbits.

The time course of antibody synthesis during syphilis was studied in experimentally infected rabbits. A rapid antibody response was seen; the rabbits became positive in both the rapid plasma reagin (RPR) test and Treponema pallidum haemagglutination assay (TPHA) by nine days after infection. Treponemal immobilising antibodies were also seen as early as nine days after infection. Antibody inhibition of treponemal attachment to baby rabbit genital organ (BRGO) cells in culture occurred with immune sera taken 30 days after infection but not earlier. When T pallidum was mixed with immune syphilitic rabbit sera taken at different stages of the infection and used to infect normal rabbits the rabbits became partially resistant to T pallidum only when the treponemes were mixed with sera taken at least 30 days after syphilitic infection. This appearance correlated well with the development of antibodies which blocked attachment of T pallidum to host cells. These antibodies may be involved in the resistance to reinfection which develops in syphilis as the disease progresses.

Animals↗
PubMed1983

The role of respiratory protection on increased survival of Treponema pallidum (Nichols) when cocultivated with mammalian cells in vitro.

The ability of mammalian cells in tissue culture to protect against oxygen toxicity for Treponema pallidum was examined. Addition of catalase to the incubation medium enhanced T. pallidum survival when co-incubation was carried out under aerobic conditions. When co-incubation was carried out under 3% oxygen, catalase had no enhancing effect on survival despite the fact it was still highly stimulatory when T. pallidum was incubated under 3% oxygen in the same medium with no tissue culture cells present. Inactivation of the catalase present endogenously in the mammalian cells by the addition of the catalase inhibitor 3-amino-1,2,4-triazole largely eliminated the enhancing effect of mammalian cells on the survival of T. pallidum under 3% oxygen. Increasing the oxygen consumption of the host mammalian cells with 0.1 mM 2,4-dinitrophenol enhanced T. pallidum under both aerobic and microaerobic conditions; a much greater effect was seen under aerobic conditions. The results indicated that mammalian cells offer significant protection against toxic oxygen reduction products for T. pallidum in vitro under microaerobic conditions.

2,4-Dinitrophenol↗
PubMed1981

Redox potential and survival of virulent Treponema pallidum under microaerophilic conditions.

A strongly reduced culture medium, capable of maintaining the virulence of Treponema pallidum (Nichols) for several days, was exposed to an atmosphere of 3% oxygen in nitrogen for 2-3 days before inoculation with T pallidum. By using various volumes of medium in uniform tubes a range of redox potentials (Ecal) from -94 mV to -325 mV was produced depending on the surface area-to-volume ratios of the medium. The anaerobic medium had an Ecal value of -387 mV. The medium was inoculated with T pallidum and incubated in an atmosphere of 3% oxygen. The survival of treponemes at different redox potentials was monitored by observing the retention of motility and by measuring the latent period of infection after inoculation of the cultures into the shaved backs of rabbits. Under these conditions T pallidum survived longest at low (electronegative) redox potential. An inverse linear relationship was observed between the redox potential of the culture medium and the survival of T pallidum, as measured by the time required for a 90% reduction of virulent organisms. No optimum redox potential was detected, the most electronegative medium (-325 mV, Ecal) giving the best survival.

Bacteriological Techniques↗
PubMed1978

[Saralasin-induced changes of blood pressure, renin and aldosterone in essential and renal hypertension (author's transl)].

In 34 patients saralasin was infused after variable degrees of sodium depletion in order to differentiate between essential and renin-induced hypertension. After sodium-depletion of short duration mean arterial pressure dropped more than 10 mm Hg in 9 of 25 patients with essential and in 7 of 9 patients with renin-induced hypertension. After long-lasting sodium depletion the fall of mean arterial pressure exceeded 10 mm Hg in 11 of 16 patients with essential and in 8 of 9 patients with renin-induced hypertension. Thus saralasin did not discriminate essential and renin-induced hypertension. Also, plasma renin concentration before and after saralasin did not allow to differentiate between the two forms of hypertension. The changes of renin during infusion of saralasin was negatively correlated to the change of blood pressure. Renal vein renin ratio in patients with renovascular hypertension was not modified by saralasin. Renin and aldosterone changed inversely during saralasin infusion.

Aldosterone↗
PubMed1978

Gender identity problems of children and adolescents: the establishment of a special clinic.

Theoretical accounts of the origins of gender identity disturbance are reviewed and then followed by a description of the establishment of a child and adolescent gender identity clinic. Clinical impressions of 16 gender disturbed patients are presented and the position is taken that most patients manifested a confused, as opposed to fixed, core gender identity.

Adolescent↗
PubMed1977

Extension of the Gender Identity Scale for Males.

Our earlier Femine Gender Identity Scale for males appear to measure a strong single factor which was reliable and displayed substantial discriminant validity. However, the number of items was small and there was substantial overlap between items with respect to their meaning. In an attempt to overcome these limitations, in the present study the scale was extended and validated. Each item of the new scale differentiated among the groups in an experimental sample and, subsequently, in a cross-validation sample. A secondary finding was the significantly higher femine gender identity scores of homosexual patients over homosexual nonpatients.

Adolescent↗
PubMed1977

The clinical profile of male transsexuals living as females vs. those living as males.

The clinical profiles of five male groups were compared: transsexuals who live as females (FEM), those who live as males (MAL), homosexual patients (HOP), homosexual controls (HOC), and heterosexual controls (CON). The MAL group showed psychotic features on the MMPI and a greater frequency of suicide attempts than the other groups. Their sexual behavior was incongruous in that they have substantial sexual contact with men but less often desired sexual contact with men. They also less often desired to handle the penis of an adult man or to kiss him on the lips. They were more likely to find handling another's penis disgusting. However, they showed considerable involvement of their penis in sex relations with men. The FEM group, in contrast, had MMPI profiles suggestive of character disorders and tended to engage in antisocial behavior. Both MAL and FEM groups were similar in MMPI and 16 PF "femininity." The HOP group showed overall similarity to MAL but was not as pathological. The HOC and CON groups were similar in being normal but their sexual behavior differed, as expected. The paradoxical behavior of MAL is discussed as well as the parallel of the FEM group's behavior to that of criminals.

Adaptation, Psychological↗