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Biomedical subjects

G Schulz

Publications and source records attributed to G Schulz.

At least 181 records · Page 10Linked to original sources
PubMed1984

Detection of ganglioside GD2 in tumor tissues and sera of neuroblastoma patients.

A murine monoclonal antibody (monoclonal antibody 126) produced against cultured human neuroblastoma cells (LAN-1) was found to be specifically directed to a disialoganglioside (GD2) antigen preferentially expressed on both cell lines and tissues derived from melanoma and neuroblastoma. In enzyme-linked immunosorbent assays, monoclonal antibody 126 failed to react with leukemic and lymphoblastoid cells as well as with a variety of carcinoma and sarcoma cell lines. Immunohistological analysis by the immunoperoxidase technique revealed strong reactivity of monoclonal antibody 126 with frozen and formaldehyde-fixed neuroblastoma and melanoma tissues. Tissues from patients with glioma or with small cell cancer of the lung showed faint staining, whereas those from individuals with sarcoma, lymphoma, and a variety of other neoplasms proved to be negative. Sera of neuroblastoma patients showed significantly elevated GD2 levels compared to normal children (p less than 0.001) and children with other tumors (p less than 0.001) as determined by a quantitative competitive enzyme-linked immunosorbent assay. Furthermore, the GD2 serum level of one neuroblastoma patient, when followed serially, was found to correlate with progression of disease, suggesting the potential usefulness of this assay for the diagnosis and monitoring of neuroblastoma.

Antibodies, Monoclonal↗
PubMed1983

Islet-activating protein discriminates the antilipolytic mechanism of insulin from that of other antilipolytic compounds.

In vivo administration of islet-activating protein to rats resulted in an increase in fat cell lipolysis in vitro, which was associated with almost complete resistance of adipocytes towards the antilipolytic effects of N6-phenylisopropyladenosine, prostaglandin E2 and nicotinic acid. Concomitantly, the inhibitory effects of these compounds on adenylate cyclase activity in membranes were impaired. In contrast, the antilipolytic action of insulin was not only preserved, but even augmented in cells from rats treated with islet-activating protein. The data suggest that insulin exerts its antilipolytic effects via mechanisms which are different from those involved in the effects of prostaglandin E2, N6-phenylisopropyladenosine and nicotinic acid.

Adenosine Deaminase↗
PubMed1983

Reticular formation of the lower brainstem. A common system for cardiorespiratory and somatomotor functions: discharge patterns of neighboring neurons influenced by cardiovascular and respiratory afferents.

Experiments were done in dogs with chloralose-urethane anesthesia. Long-lasting extracellular recordings were made from the medial parts of the reticular formation of the lower brainstem for up to 250 min. The study is based on reactions of 103 neurons. The activities of 2 or 3 neighbouring neurons recorded under identical conditions with one electrode or of neurons recorded with two electrodes at the same time could be changed regularly and synchronously by experimental changes of hemodynamic or ventilatory parameters. Action potentials were separated by amplitude discrimination. Rhythmic pulsatile modulations were proved to be present in 78% of all neurons by post-event-time histograms triggered by the R-wave of the ECG. In the 96 neurons tested 86% changed their activity when arterial pressure was raised by inflating a balloon in the abdominal aorta (79% decreased and 7% increased their activity). In post-event-time histograms triggered by the start of inspiration, 83% of the neurons showed modulations of their activity with respiratory rhythm. Experimental lung inflation decreased the activity in 75% of the tested neurons, while experimental lung deflation activated 47% of the tested neurons. Stimulation of arterial chemoreceptors activated 77% of the tested neurons. It was thus demonstrated that receptors in the cardiovascular and respiratory systems exert an influence on nearly all neurons from which recordings were made in that part of the reticular formation. Arterial baroreceptors and lung stretch receptors revealed a generalized depressing effect on the neuronal activity while chemoreceptors exert a generalized augmenting effect. At different times of recording these neurons did not always react to the same extent to comparable stimulations of afferents.

Action Potentials↗
PubMed1983

Reticular formation of the lower brainstem. A common system for cardiorespiratory and somatomotor functions: discharge patterns of neighboring neurons influenced by somatosensory afferents.

Extracellular recordings were made from 103 neurons located in the medial parts of the reticular formation of the lower brainstem of chloralose-urethane anesthetized dogs. Activities of 2 or 3 neighbouring neurons under identical conditions could be recorded with one electrode. In 9 recordings it was possible to register simultaneously up to 5 neurons with two electrodes placed in both halves of the medulla. Action potentials of individual neighbouring neurons were identified by amplitude discrimination. The influences of somatosensory afferents from skin, joints and muscles on neuronal discharge patterns were tested. Responses of single neurons were characterized by multisensory afferent spectra including afferents from various parts of the body. The combinations of afferents converging onto neighbouring neurons were similar, whereas neurons in more distant parts of the medulla revealed different combinations of converging afferents. In long-lasting recordings the influence of somatosensory afferents on the discharge behaviour changed from time to time. When the discharge behaviour was mainly determined by somatosensory afferents, neighbouring neurons were shown to be organized in sub-populations. The results led to the conclusion that in this part of the reticular formation different types of functional organization of the neuronal network are possible. The type of functional organization depends on the actual preponderances of different inputs to the neurons.

Animals↗
PubMed1983

Monoclonal antibody-directed effector cells selectively lyse human melanoma cells in vitro and in vivo.

Monoclonal antibody 9.2.27 (mAb 9.2.27) directed to a chondroitin sulfate proteoglycan on human melanoma cells was able to suppress tumor growth in athymic (nu/nu) mice more effectively when bound with polyethylene glycol to murine effector cells than when injected alone. These "armed" effector cells also proved more effective than the monoclonal antibody in eliciting antibody-dependent cellular cytotoxicity against human melanoma target cells in vitro.

Animals↗
PubMed1983

Effect of substituted benzimidazoles on acid secretion in isolated and enriched guinea pig parietal cells.

The inhibitory effect of the three benzimidazole derivatives timoprazole, picoprazole, and omeprazole on histamine and dbcAMP stimulated 14C-aminopyrine accumulation (= H+ secretion) has been studied in isolated and enriched guinea-pig parietal cells. All compounds tested inhibited H+ secretion in a concentration dependent manner with IC50 values of 8.5 +/- 1.9 mumol/l for timoprazole, 3.9 +/- 0.7 mumol/l for picoprazole, and 0.13 +/- 0.03 mumol/l for omeprazole. The IC50 of timoprazole, when dbcAMP was used as a stimulus, did not differ significantly from that of histamine stimulation. The type of inhibition was of a non-competitive nature. The full acid response to histamine after temporary exposure of the cells to the benzimidazoles could be restored by washing the cells twice; this suggests that the inhibition is reversible. The data - among others - indicate that the properties of the benzimidazoles described here would allow these compounds to be used as effective antisecretagogues.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1982

The effect of dietary fiber on pancreatic amylase activity in vitro.

In vitro the influence of wheat bran, guar gum, psyllium and lignin (2.5-50 g/l) on porcine pancreatic amylase (5-10 U/ml) was investigated. Enzyme activity was decreased in the presence of these substances with the exception of lignin. The reduction depended upon fiber concentration. In bran (50 g/l) it was 92 +/- 1%, in guar gum (25 g/l) 46.3 +/- 0.6%, and in psyllium (50 g/l) 41 +/- 1.4%. The effect was partly reversible if urea (1M) was added. Variations in pH (5.8-7.8) had no influence. Glucose formation from starch catalyzed by amylase was inhibited in the presence of bran, guar gum and psyllium, suggesting that the observed effect was also of functional significance.

Amylases↗
PubMed1981

[Blood-sugar-controlled insulin infusion systems for rapid adjustment of insulin-dependent diabetics (author's transl)].

Empirically obtained data could be verified and the basis for assessment of total insulin requirement, circadian distribution of insulin doses and contents of single insulin portions of old and delayed-action insulin could be established in a prospective study in 13 insulin-dependent diabetics. Assessment of insulin requirements was done after a 36-hour investigation period with the artificial endocrine pancreas using standardised conditions. Readjustment was complemented by dietary advice and rearrangement of total calory input and distribution of carbohydrates during the day. Therapeutic success in 55 patients justifies this procedure. Adjustment of insulin-dependent diabetics was thus obtained more rapidly, better and at less cost.

Adolescent↗
PubMed1981

Central control and interactions affecting sympathetic and parasympathetic activity.

Current thinking concerning the central control of the autonomic nervous system and the central interactions affecting sympathetic and parasympathetic activity is presented. Among the questions discussed are the following: are there neurons within the common brain stem system which exert an influence on preganglionic parasympathetic neurons and can they be differentiated from neurons which affect sympathetic preganglionic neuron functions? What interactions occur between sympathetic and parasympathetic tone-mediating neurons? In discussing these problems information is presented as obtained by recording from reticular formation (RF) neurons with discharge patterns similar to efferent parasympathetic activity. The general conclusion reached is that there is a common central control; interactions occur in the brain stem as well as peripherally; depending on the functional situation, these two systems can be organized to act either reciprocally or non-reciprocally.

Afferent Pathways↗
PubMed1980

[The value determination of serum aldolase for findings of metastases and relapses on bronchial carcinoma (author's transl)].

In 180 patients with histologically confirmed bronchial carcinoma exactitude of aldolase as a means for carrying out a screening test for metastases and relapses was checked. Enzyme activity was mostly normal in patients with limited extended local tumor growth including regional metastases as well as in tumour relapses. The group of patients with distant metastases, showed a distribution of increases and normal enzyme values which was equal; when differentiating further the majority of pathological aldolase values (79.4 per cent) was found in the group with liver metastases. We therefore regard as valuable the determination of serum aldolase when locking for liver metastases in confirmed bronchial carcinoma.

Adult↗
PubMed1980

[Stress and aging (author's transl)].

Under the influence of stress the function of hypothalamic-pituitary system seems to show aging changes, whereas the adrenocortical function is not changed in spite of degenerative morphological changes in aging. By the performance and interpretation of experiments it is necessary to pay attention to the different reaction of young and old animals.

Aging↗
PubMed1980

[The treatment of lung fibrosis (author's transl)].

D-Penicillamine is increasingly used for the treatment of lung fibrosis. The case-histories of 46 patients from 4 chest hospitals were analysed. All parameters being taken in consideration 13 patients showed an improvement, 17 patients no change and 16 patients a deterioration of their state of health. Side effects were observed in 22 patients.

Adult↗
PubMed1979

[Disorders of psychological performance in mentally normal school children].

The authors deal with such psychic factors as weaknesses in concentration, reading and spelling which are to a major degree responsible for failure at school. These factors often occur in combination and may indicate early brain damage, in complex interaction with milieu conditions. Ample evidence of this is given in a literature survey. Principles of concentration training and a diagnostic verification procedure are then outlined, which have been derived from an analysis of attention requirements made at school. A therapy for reading and spelling weaknesses is dealt with, followed by a presentation of the results of training and catamneses. Using the method of Kossow mistakes were reduced by 78 percent and spelling marks improved considerably, after the children had returned to their original schools. In conclusion information is given on future projects for better assistance and prevention in the case of reading and spelling weaknesses at the elementary stage.

Brain Damage, Chronic↗