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Biomedical subjects

E Kaiser

Publications and source records attributed to E Kaiser.

At least 19 recordsLinked to original sources

Exons encoding the highly conserved part of human glutaminyl-tRNA synthetase.

Aminoacyl-tRNA synthetases are important components of the genetic apparatus. In spite of common catalytic properties, synthetases with different amino acid specificities are widely diverse in their primary structures, subunit sizes, and subunit composition. However, synthetases with given amino acid specificities are well conserved throughout evolution. We have been studying the human glutaminyl-tRNA synthetase possessing a sequence of about 400 amino acid residues (the core region) that is very similar to sequences in the corresponding enzymes from bacteria and yeast. The conserved sequence appears to be essential for the basic function of the enzyme, the charging of tRNA with glutamine. As a first step to a better understanding of the evolution of this enzyme, we determined the coding region for the conserved part of the human glutaminyl-tRNA synthetase. The coding region is composed of eight exons. It appears that individual exons encode defined secondary structural elements as parts of functionally important domains of the enzyme. Evolution of the gene by assembly of individual exons seems to be a viable hypothesis; alternative pathways are discussed.

Amino Acid Sequence

Hypoxia-mediated induction of endothelial cell interleukin-1 alpha. An autocrine mechanism promoting expression of leukocyte adhesion molecules on the vessel surface.

Tissue injury that accompanies hypoxemia/reoxygenation shares features with the host response in inflammation, suggesting that cytokines, such as IL-1, may act as mediators in this setting. Human endothelial cells (ECs) subjected to hypoxia (PO2 approximately 12-14 Torr) elaborated IL-1 activity into conditioned media in a time-dependent manner; this activity was completely neutralized by an antibody to IL-1 alpha. Production of IL-1 activity by hypoxic ECs was associated with an increase in the level of mRNA for IL-1 alpha, and was followed by induction of endothelial-leukocyte adhesion molecule-1 and enhanced expression of intercellular adhesion molecule-1 (ICAM-1) during reoxygenation. During reoxygenation there was a three- to five-fold increased adherence of leukocytes, partly blocked by antibodies to endothelial-leukocyte adhesion molecule-1 and ICAM-1. Suppressing endothelial-derived IL-1, using either antibodies to IL-1 alpha, specific antisense oligonucleotides or the IL-1 receptor antagonist, decreased leukocyte adherence to reoxygenated ECs, emphasizing the integral role of IL-1 in the adherence phenomenon. Mice subjected to hypoxia (PO2 approximately 30-40 Torr) displayed increased plasma levels of IL-1 alpha, induction of IL-1 alpha mRNA in the lung, and enhanced expression of ICAM-1 in pulmonary tissue compared with normoxic controls. These data suggest that hypoxia is a stimulus which induces EC synthesis and release of IL-1 alpha, resulting in an autocrine enhancement in the expression of adhesion molecules.

Animals

[The effect of arteriosclerosis on the wall elasticity of the human common carotid artery].

The arterial distensibility and the modulus of volume elasticity of more than 100 isolated human carotid arteries was measured and correlated with arteriosclerosis and aging. The loss of arterial distensibility progresses steadily with aging. Arteries with severe arteriosclerosis and arteries with minimal arteriosclerosis show almost similar distensibility. On the other side the differences between distensibility of arteries with moderate arteriosclerosis and arteries with minimal as well as severe arteriosclerosis, especially in the younger and middle ages, are significant.

Aging

[Decreased plasma carnitine in Type I diabetes mellitus].

Realizing the importance of carnitine for the lipid and carbohydrate metabolism and the possible role for glucose utilization and myocardial function carnitine concentrations in type I and type II diabetic patients in plasma, erythrocytes and 24 h urine were determined. The plasma levels of carnitine were significantly diminished in type I diabetic patients compared to controls, while carnitine concentrations in erythrocytes and 24 h urine did not differ from controls. Plasma carnitine levels did not change significantly during the diurnial profile. No correlation between HbA1c and carnitine levels was observed in the diabetic patients.

Adult

[Long-term studies with an anti-androgen/estrogen combination preparation of its effectiveness, liver tolerance and lipid metabolism in females].

The usefulness of antiandrogenic therapy with cyproterone acetate for androgenisation signs and symptoms in women, when tumours are definitely not the cause, has now been confirmed world-wide in about 100,000,000 therapy cycles using the hormonal contraceptive Diane and its follow-up preparation Diane-35, which contains a lower level of oestrogen. Nowadays, low-dose hormonal contraceptives are preferred in order to minimise the so-called "internal" risk by reducing the level of the oestrogen component and, by careful selection of the progestin, minimising the residual androgenic effect. In an open study on 150 women with moderately severe symptoms of androgenisation, we assessed, for treatment periods of up to 36 cycles, the effect of the only oestrogen-reduced hormonal contraceptive with anti-androgenic activity (Diane-35), and also monitored biochemical parameters, which are indicative of high risk metabolic activity and permit an accurate characterisation of the hormonal contraceptive, especially with long-term use. Although the parameters of liver and fat metabolism occasionally yielded values close to the limit of the normal range, it was particularly favourable to note, that the lipoprotein fraction HDL exhibited a slightly rising tendency, whereas, at the same time, the LDL fraction dropped. Special attention has been paid to ultrasonographic monitoring of the liver, since the influence on the function of this organ has been frequently discussed in conjunction with prolonged use of 17-alpha-alkylated steroidal compounds, and because a possible connection between sex steroids and the development of liver tumours has been a point of discussions.(ABSTRACT TRUNCATED AT 250 WORDS)

Acne Vulgaris

[Lafora disease (progressive myoclonic epilepsy) in the Bassett hound--possibility of early diagnosis using muscle biopsy?].

A progressive, hereditary disease has been observed in Basset Hounds, which appears clinically and neuromorphologically as myoclonus epilepsy (ME) and is similar to Lafora-Glueck disease in humans. The characteristic intracellular accumulations are typical myoclonus inclusion bodies. Four forms of inclusion bodies (IB) can be distinguished: a) very small, homogeneous, PAS-positive IBs, b) IBs consisting of an accumulation of PAS-positive particles, c) IBs with a concentric internal structure and a smooth or radial outer zone, and d) IBs with a homogeneous center, concentric layering, light intermediate zone, and a smooth outer zone. The occurrence of IBs is restricted largely to nerve cells. Here they are located mainly in pericarya, to a lesser extent in dendrites, and rarely in the neurites of the peripheral nervous system. IBs are also found in samples of skeletal muscle where they lie between myofibrils or beneath the sarcolemma. They are slightly basophilic in HE-staining and markedly PAS-positive. In transmission electron micrographs IBs prove to consist of chain-like filamentous material of varying density with focal concentrations. They are similar to IBs of the brain. Both muscular and neuronal IBs lack surrounding membranes. Diagnosis of Lafora disease in dogs by examination of muscle biopsies is discussed.

Animals

Pathomorphologic findings in short-tailed voles (Microtus agrestis) experimentally-infected with Frenkelia microti.

Following oral infection of Microtus agrestis with sporocysts of Frenkelia microti, transient focal necrosis and cellular infiltrations in the liver, hyperplasia of lymphoid organs, and inflammatory infiltrations in the heart, pulmonary veins, skeletal muscles and brain occurred during the first asexual multiplication period of the parasite in the liver. Frenkelia cysts were first observed in the brain 23 days after infection.

Animals

[Life cycle of Frenkelia. IV. Pathomorphological findings in the organs of experimentally infected bank voles].

In 1975 the buzzard (Buteo buteo) was found to be the final host of Frenkelia clethrionomyobuteonis. After this discovery it became possible to investigate systematically the pathomorphology of the infection in the intermediate host, the bank vole (Clethrionomys glareolus). Fifty bank voles were infected orally with a suspension of sporocysts recovered from the faeces of experimentally infected buzzards. Each rodent receive 7000 sporocysts. Six controls each were given a faecal suspension from a non-infected buzzard. The voles were killed between 1 and 140 days after infection and examined histologically. Between the 5th and 8th day of the infection during the schizogonic multiplication of the parasite a focal necrosis of liver cells and of the liver parenchyma is observed followed by a reversible resorptive inflammation associated with siderophagia and the occurrence of giant cells. The spleen was spodogenously enlarged up to twice its normal size. There also was haemosiderosis of the bone marrow, the liver and the spleen up to 25 days after infection. At the same time the erythropoiesis in the bone morrow, the spleen and in the lymph nodes increased; there also was a lymphoid hyperplasia in spleen and lymph nodes. About 10 days after infection a reversible infiltration with lymphocytes and plasma cells developed in the liver, heart and brain. This infiltration was again detectable as perivascular and meningeal reactions in the brain after the 49th day after infection. The second asexual multiplication of the parasite was seen histologically in the grey and white matter of the central nervous system after the 18th day of infection. The developing cysts increased in size continuously thereby compressing the surrounding nervous tissue. Disseminated focal necrosis with resorptive inflammatory components was prominent in the parenchyma of the brain after the 49th day of infection. It was possible to differentiate between damage in single organs and systemic pathological lesions. The lesions in single organs were directly connected with the development of parasitic stages in the liver (schizonts) and in the brain (cysts). The generalized lesions occurred in the haemopoietic system after an impairment of the blood during the first asexual multiplication. They also occurred in the immunocytic systems after the first and during the second asexual multiplication and during the relatively late cystic phase of the parasite in the brain. The pathogenesis of the disintegration of blood cells is not clear. The immunocytic reaction can be considered an immunological response of the host against the parasite. The effect of the development of the cysts on the function and structure of the central nervous system is expected to lead to an increasing impairment of the motility of the intermediate host.

Animals

[Effect of menstrual hygiene (tampons vs pads) and of the form of contraception on pH and bacterial infection of the vagina].

In menstrual hygiene vaginal tampons are preferred. Supposedly intravaginal application causes discharge. Healthy women using pads as well as tampons were examined before, during, and after menstruation. During two menstrual cycles vaginal pH was measured, bacteriological and mycological cultures were set up. The results indicated no changes of cervical-vaginal-secretion, nor was the pH changed. Taking the used contraceptive method into consideration, we found that intrauterine devices and oral contraceptives caused most of bacterial discharge and the expected shifting to alcaline pH. No increase of vaginal fungus was noted. The use of intravaginal tampons for menstrual bleeding therefore had no ill effects.

Adolescent