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Biomedical subjects

J Bauer

Publications and source records attributed to J Bauer.

At least 541 records · Page 30Linked to original sources
PubMed1986

Pre-stereoptic binocular vision in infants.

In a preferential looking experiment, identical patterns (vertical stripes) were presented to both eyes on one of two screens while orthogonal patterns (vertical stripes in one eye and horizontal stripes in the other) were presented on the other screen. Most infants younger than 3.5 months of age originally showed a preference for the dichoptic (interocularly orthogonal) pattern. At an average age of 3.5 months, however, they showed a sudden shift of preference from this pattern to the interocularly identical pattern. The full shift from a preference for one stimulus to the other (both statistically significant) occurred within a few weeks in most cases. The onset age of the shift in preference agreed with the onset age of fusion-rivalry discrimination found in a previous study (Birch et al., 1985). The original preference for the bincularly orthogonal patterns may be interpreted as a preference for a grid (interocularly emergent intersections) over a grating, judging from results of two control experiments. These data suggest that the pre-stereoptic system non-selectively combines information from the two eyes without regard to edge orientation because it loses eye-of-origin information at a relatively early stage of binocular visual processing. Thus, the pre-stereoptic system does not have the capability of interocular suppression. The theoretical and clinical significance of the new findings are discussed along with a neuronal model of cortical development of ocular segregation and binocular pathways.

Adult↗
PubMed1986

Studies on the activation mechanism of human mononuclear leukocytes isolated by physical methods.

Responder lymphocytes, accessory lymphocytes and monocytes were isolated using countercurrent centrifugal elutriation and free flow electrophoresis. The Concanavalin A (Con A) binding behaviour of the isolated cell populations was studied. Responder lymphocytes and accessory cells bound Con A by different mechanisms. Cells in all the isolated populations were able to interact directly with Con A. Con A binding to responder lymphocytes was inhibited by alpha-methylmannoside (alpha MM) and by a distinct plasma protein. Accessory lymphocytes and monocytes bound Con A even in the presence of 10% human plasma or 50 mM alpha MM. The plasma protein which inhibited interaction of responder lymphocytes with Con A also reduced lymphocyte proliferation, when resting monocytes were used as accessory cells. If, however, monocytes were used after activation by lipopolysaccharide no inhibition effect was observed. From the results we conclude that there is a distinct plasma protein which protects the organism against lymphocyte stimulation not controlled by accessory cells. This inhibitory plasma protein appears to be a euglobulin.

Blood Proteins↗
PubMed1986

The acute-phase induction of alpha 2-macroglobulin in rat hepatocyte primary cultures: action of a hepatocyte-stimulating factor, triiodothyronine and dexamethasone.

During inflammation a number of liver-derived plasma proteins increases in concentration. In the rat these so-called acute-phase proteins are mainly proteinase inhibitors, such as alpha 1-proteinase inhibitor, alpha 1-acute-phase globulin and alpha 2-macroglobulin. At present, the mechanisms responsible for the enhanced synthesis of acute-phase proteins are poorly understood. Therefore, we have studied the induction of alpha 2-macroglobulin synthesis in rat hepatocyte primary cultures. Adrenaline, triiodothyronine, estradiol and progesterone were tested for their ability to stimulate alpha 2-macroglobulin synthesis. Only triiodothyronine induced alpha 2-macroglobulin synthesis markedly. However, the presence of dexamethasone was a prerequisite for alpha 2-macroglobulin induction indicating a permissive action of glucocorticoids. Besides glucocorticoids and triiodothyronine a non-dialyzable factor (HSF) derived from rat Kupffer cells or human peripheral blood monocytes was found to be able to stimulate alpha 2-macroglobulin synthesis in hepatocytes. Equal amounts of HSF activity were found in conditioned media from lipopolysaccharide-stimulated and unstimulated rat Kupffer cells as well as in human monocytes. Since the supernatants of unstimulated rat Kupffer cells or human monocytes did not exhibit interleukin 1 activity, HSF activity distinct from interleukin 1 must exist. No HSF activity was found in media conditioned by rat Kupffer cells which had been treated with dexamethasone. Hepatocyte primary cultures were incubated with [35S]methionine-labeled proteins secreted by rat Kupffer cells. A 30 kDa polypeptide was found to be bound to or internalized by rat hepatocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

The effect of alcoholism on membrane lithium transport.

Red cell lithium efflux rates in major affective disorder and alcoholic patient groups were studied. Current alcoholism was associated with significant elevation of lithium transport in white but not black subjects. This effect of alcoholism on the characteristics of membrane ion transport was independent of the blood pressure elevating effects of alcoholism and the diagnosis of major affective disorder. A model to explain the mechanism of this race-specific membrane effect of alcoholism is proposed and discussed.

Alcoholism↗
PubMed1986

[Diagnosis and therapy of candidiasis in the premature infant].

Extension of intensive care seems to have increased the risk of systemic candida infection. We report the incidence of systemic candida infection in 8 low-birth-weight infants (gestational age 27-32 weeks, birth weight 710-1,550 g). All infants required respiratory treatment. Various silastic catheters were inserted. Antibiotic therapy was started on the first day of life, usually a combination of ampicillin and gentamycin. Candida septicaemia was diagnosed at the age of 8-69 days of life based on blood and urine cultures, in two children at autopsy. There were no specific clinical symptoms in regard to candida infection. Sonographic technique revealed hydronephrosis in 3 infants due to candida mycelium. Antimycotic therapy included amphotericin B (dosage 0.44-1.0 mg/kg X day) and 5-fluorocytosine (80-100 mg/kg X day) as well as a monotherapy of 5-fluorocytosine (100-200 mg/kg X day). Four children were treated successfully. We like to advice a regular search for candida in urine, blood, tracheal secretion, stool and skin in low-birth-weight infants under intensive care conditions. If antimycotic therapy is started in time, therapy can be successful.

Anti-Bacterial Agents↗
PubMed1985

Murine interleukin 1 stimulates alpha 2-macroglobulin synthesis in rat hepatocyte primary cultures.

In rat hepatocyte primary cultures recombinant interleukin 1 was found to stimulate alpha 2-macroglobulin synthesis, whereas albumin synthesis was decreased. Although recent experiments gave evidence that a hepatocyte-stimulating factor distinct from interleukin 1 must exist, we conclude that interleukin 1 exerts a direct effect on hepatocytes by inducing acute-phase protein synthesis.

Albumins↗
PubMed1985

Biosynthesis and secretion of alpha 1 acute-phase globulin in primary cultures of rat hepatocytes.

Experimental inflammation in rats led to a sevenfold increase in serum levels of alpha 1 acute-phase globulin. This increase is correlated with elevated levels of translatable mRNA for alpha 1 acute-phase globulin in the liver. Biosynthesis and secretion of alpha 1 acute-phase globulin were studied in rat hepatocyte primary cultures. An intracellular form of alpha 1 acute-phase globulin with an apparent relative molecular mass of 63 500 and a secreted form of 68 000 were found. The intracellular form of alpha 1 acute-phase globulin could be deglycosylated by endoglucosaminidase H treatment indicating that its oligosaccharide chains were of the high-mannose type. The secreted form of alpha 1 acute-phase globulin was not sensitive to endoglucosaminidase H, but was susceptible to the action of sialidase reflecting carbohydrate side-chains of the complex type. Pulse-chase experiments revealed a precursor-product relationship for the high-mannose and the complex type alpha 1 acute-phase globulin. In the hepatocyte medium newly synthesized alpha 1 acute-phase globulin was detected 30 min after the pulse. Unglycosylated alpha 1 acute-phase globulin was found in the cells as well as in the medium when the transfer of oligosaccharide chains onto the polypeptide chains was blocked by tunicamycin. Tunicamycin led to a marked delay in alpha 1 acute-phase globulin secretion.

Animals↗
PubMed1985

Spatial vision in Alzheimer's disease. General findings and a case report.

Visual contrast sensitivity to sinusoidal gratings of five spatial frequencies was measured in 15 patients with Alzheimer's disease and in eight control subjects. Contrast sensitivity thresholds were elevated at all frequencies in 14 patients compared with control subjects. The 15th patient was unique: she had an impairment in object and face recognition so severe that she could not recognize her husband visually. Her sensitivity to low and intermediate frequencies was markedly reduced in relation to that of other patients, whereas her sensitivity to the highest frequency tested equaled theirs. These observations emphasize the importance of low spatial frequency information for visual object and face recognition.

Blood Physiological Phenomena↗
PubMed1985

Distribution of colorectal cancer in patients with and without ulcerative colitis.

A comparison of the anatomic distribution of colorectal cancer in patients with and without CUC is difficult because of the unequal number of patients in each group and the changing epidemiologic parameters of colorectal cancer in general. In the present study, the distribution of colorectal tumors in patients with and without CUC was compared over two different time periods at a single hospital. In the early time period (1960 to 1975), there was a significantly higher percentage of proximal tumors in the group with cancer and CUC compared to the group with cancer alone. In the most recent time period (1975 to 1981), there was no difference in distribution of colorectal cancer regardless of whether the patient had CUC or not. We believe that the increased percentage of proximal tumors in patients with colorectal cancers and no CUC that has occurred in recent years has led to the present findings of a similar distribution of tumors in patients with and without CUC.

Adenocarcinoma↗