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Biomedical subjects

R Kaiser

Publications and source records attributed to R Kaiser.

At least 235 records · Page 13Linked to original sources
PubMed1981

The cellular response of T and B dependent areas of the spleen after focal thermocoagulation of liver and kidney.

Using 3H-thymidine autoradiography, the cellular response of the white splenic pulp after single or repeated thermolesions on liver and kidney was studied. Sham operations served as controls, and did not induce any significant changes in the splenic white pulp. After single or repeated thermolesions, the labeling index increased distinctly in the B and T cell areas. The central T-dependent periarteriolar lymphatic sheath (PALS) showed an earlier rise of radioactively labeled lymphocytes after repeated thermolesions than after a single lesion. After a single heat coagulation of liver and kidney a dissociation of the germinal centers occurred with consecutive hyperplasia. However, compared with the splenic reaction after other surgical injuries, especially after cryosurgical operations, the response of the B-dependent splenic areas was weaker. The distinct reaction of the central T-dependent PALS supports the conception of a more prominent cell mediated immune response of the peripheral lymphatic system with temporary T cell dysfunctions. Possibly the inflammatory complications of burned patients and the delayed wound healing of thermosurgical tissue lesions may be caused by the alteration of the lymphatic system with a disturbed cooperation of T and B lymphocytes with macrophages.

Animals↗
PubMed1981

Catalytic mechanism of serine proteases: reexamination of the pH dependence of the histidyl 1J13C2-H coupling constant in the catalytic triad of alpha-lytic protease.

L-Histidine, 90% 13C enriched at the C2 position, was incorporated into the catalytic triad of alpha-lytic protease (EC 3.4.21.12) with the aid of histidine-requiring mutant of Lysobacter enzymogenes (ATC 29487), and the pH dependence of the coupling constant between this carbon atom and its directly bonded proton was reinvestigated. The high degree of specific 13C isotopic enrichment attainable with the auxotroph permits direct observation and measurement of this coupling constant in proton-coupled 13C NMR spectra at 67.89 MHz and at 15.1 MHz. In contrast to the earlier study, the present study indicate that this coupling constant does respond to a microscopic ionization with pKa near 7.0; moreover, the magnitude of the values of 1JC-H observed are in accord with those expected for titration of the histidyl residue. We conclude that the original measurement must be in error and that this coupling constant now also supports a histidyl residue that titrates more or less normally as a component of the catalytic triad of serine proteases.

Catalysis↗
PubMed1979

[The structure of decidual mucosa in the accessory horn of an uterus bicornis (author's transl)].

The loosely attached decidual mucosa in the accessory horn of an uterus bicornis does not principally differ from the mucosa in the horn containing the fetus. Structural studies show that the regression of decidual endometrium to a endothelium-like lining is a hormone-dependent process such as stromagland dissociation. Mechanical factors due to expansion of the fetus certainly play no major role. Degenerative phenomena, such as focal necrosis, sclerosing edema, thrombosis, and inflammatory infiltrates probably appear more frequently in the accessory horn. They may be explained by more pronounced regional disturbances concerning perfusion and the inferior sealing of the uterine cavity.

Adult↗
PubMed1979

Left ventricular volumes by gated equilibrium radionuclide angiography: a new method.

To compare radionuclide end-diastolic (EDV) and end-systolic (ESV) volumes with angiographic volume, we studied 52 patients with equilibrium radionuclide angiography using 99mTc-human serum albumin within 48 hours of contrast angiography. Each RR interval was divided into 20--28 equally timed frames and a time-activity curve generated. End-diastolic counts were taken at the early peak of the curve and end-systolic counts at its nadir. Counts were divided by the total number of processed heart beats and normalized for: 1) dose per body surface area; 2) plasma volume; and 3) counts/ml of plasma. A cardiac phantom was developed and serial volumes were studied using a normalization factor. Radionuclide values were expressed as dimensionless units and compared with either biplane angiographic volumes (in the patient studies) or known phantom volumes. Good correlations were obtained with methods 1 and 2 in 35 patients (r greater than 0.84), but the best correlation was obtained in 17 patients when normalization for counts/ml of plasma was used (r = 0.98; y = 0.255 x -0.121). The standard error of the estimate (SEE) was +/- 11.5 ml for EDV and +/- 7.3 ml for ESV. The phantom study also showed an excellent correlation (r = 0.99), with a SEE of +/- 6.5 ml. We conclude that a radionuclide method independent of geometric assumptions can be used to estimate left ventricular volume in man.

Adult↗
PubMed1979

[Ovarian function and vegetative complaints after hysterectomy in normally cycling women (author's transl)].

The assessment of the hormonal cycle after hysterectomy by means of radioimmunological determination of FSH, LH, Progesterone and Estradiol-17beta in serum and BBT-measurement revealed no obvious difference to a corresponding control-group of preclimacteric and climacteric women. The vegetative climacteric syndrome is much more frequently connected with the stable hypergonadotropic type than with the fluctuating hypergonadotropic or normogonadotropic type. Within the last two groups there is no correlation between vegetative complaints and the exent of ovarian function.

Adult↗
PubMed1978

[Hormonal status of women after hysterectomy compared with controls (author's transl)].

Plasma-FSH, -LH, -Estradiol-17beta, and -Progesterone were determined weekly in women aged between 28 and 43 years who had been hysterectomized 5-10 years before. The endocrine parameters were compared with those of women with a normal cycle and two groups of premenopausal women, the one showing a fixed hypergonadotropic state, the other slightly elevated but still cyclic fluctuations of FSH and normal LH values. After hysterectomy, normal ovulatory cycles were found in all women of up to 40 years, in 75% of those between 41 and 45 years and in 50% of those beyond 46 years. The average age of women with fluctuating or fixed hypergonadotropism was 2 years less in the hysterectomiced group. Thus, a certain acceleration of ovarian insufficiency caused by hysterectomy cannot be denied.

Adolescent↗
PubMed1978

Comparative study of lesions in the brain of rats exposed to heavy ions: accelerator and stratospheric flight research.

Irradiations of rat's brain with heavy ionized particles (12/6C, 291 Mev/nucleon, 100 to 300 ions/mm2) have been carried out at the Lawrence Berkeley Laboratory. Exposures were made with slowed ions which stopped within the brain as well as with more energetic particles which passed through. Histological examination of irradiated encephalons by optical microscopy showed zones of glial reaction and an increased number of darkly staining cells. By electron microscopy, intercellular edema, various alterations of nervous cells and macrophagy were observed, especially with stopped ions.

Animals↗
PubMed1978

[Vascularization and glial structures of the area postrema in sheep (Ovis aries) (author's transl)].

The area postrema of the sheep (Ovis aries) reveals the typical position and structure as seen in the domestic animals. The fetal development of the organ concerning especially the vascularization does not give any reference to a phylogenetic connection with the area postrema of birds. The glial border of the organ ist strikingly marked by the funiculus separans, which seems to be lacking in other domestic animals.

Animals↗