Biomedical subjects

G Brunner

Publications and source records attributed to G Brunner.

At least 73 records · Page 4Linked to original sources

PubMed1983

Immobilization of S-methyltransferase.

S-methyltransferase was solubilized from pig liver microsomes by treatment with N-dodecyl-N,N-dimethyl-3-ammonio-1-sulfonate (Zwittergent). The soluble enzyme was immobilized by covalent binding to agarose and by copolymerization with acrylamide. The specific activity for the agarose-bound enzyme towards the substrate ethane thiol was 0.87 nmol/min/mg and for the acrylamide-bound enzyme 0.55 nmol/min/mg. The specific activity of the soluble enzyme was found to vary with increasing chain length of the substrate molecules from 0.5 nmol/min/mg for methane thiol (C1) to 6.3 nmol/min/mg for n-heptane thiol (C7). After binding of the enzyme to agarose beads, the increase in specific activity towards substrates with increasing chain length was no longer detectable. Instead, a relatively constant specific activity of 1.1 nmol/min/mg was observed for the whole range of substrates tested from C1 to C7. The stability of the agarose immobilized enzyme at -20 degrees C is twice as good as the soluble enzyme. The acrylamide immobilized enzyme is less stable than the soluble enzyme.

Animals↗

PubMed1983

Solubilization characteristics of pig liver S-methyltransferase.

S-methyltransferase was solubilized from pig liver microsomes by five different types of detergents: Triton X-100, zetyltrimethyl-ammonium bromide, sodium cholate, Zwittergent, and sodium dodecylsulfate. As regards enzyme activity, stability, and critical detergent concentration, Zwittergent proved superior to the four other detergents utilized. A striking difference was found in the catalytic activity relative to the chain length of homologous substrates between the microsomal and the solubilized enzyme. The microsomal enzyme preparation showed highest activity towards C1 substrate (methane thiol) while the solubilized enzyme had its maximal activity for C7 substrate. This observation accorded with the active site affinity for the corresponding substrates. From the reaction of the enzyme to the different detergents and the distribution coefficient of substrates in membranes and cytosol, it can be deduced that the enzyme is located on the surface of microsomal membranes with the active site directed towards the cytoplasm.

Animals↗

PubMed1983

Effect of sucralfate on peptic ulcer recurrence: a controlled double-blind multicenter study.

We entered 174 patients with healed duodenal ulcer and 77 with healed gastric ulcer into a double-blind, placebo-controlled, 6-month trial to investigate the efficacy of 1 g sucralfate twice daily in preventing ulcer recurrence. Endoscopy was performed after 6 months or earlier for symptoms compatible with ulcer disease. The relapse rate in the 126 patients with duodenal ulcer who could be evaluated for efficacy was 14/66 (21.2%) under sucralfate and 30/60 (50%) under placebo treatment (p less than 0.01). No significant difference in relapse rate was found in the 55 gastric ulcer patients who could be evaluated; 11 of 30 (37%) relapsed on sucralfate and 11 of 25 (44%) relapsed on placebo. Among the duodenal ulcer patients in the placebo group, those who had been treated initially with H2-receptor blockers for acute ulcer had significantly more relapses than patients who had been treated with other drugs. The recurrence rate was independent of prior treatment in the sucralfate group. Duodenal ulcer patients with a history of multiple episodes of active ulcer disease had a significantly higher rate of relapse than patients with only a few previous episodes. Both treatments were well tolerated. Two patients in each treatment group complained of nausea and epigastric pain immediately after drug intake. No other drug-related symptoms were observed. We conclude that sucralfate is effective in the prophylaxis of duodenal ulcer. No significant effect was found in the prevention of gastric ulcer recurrence.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum↗

PubMed1983

[Long-term EEG recording in comparison with sleep deprivation and other provocation methods in epilepsy patients].

37 epileptics with routine records without paroxysms were subject to 24 hours mobile long-term EEG registration and independently 24 hours sleep deprivation EEG including hyperventilation and photic stimulation. The anticonvulsive treatment was not changed. In 14 cases we could prove epileptiform discharges (= positive finding) by using both methods, in 13 after sleep derivation (10 at rest, 3 only during hyperventilation) in 7 in the long-term record and in 6 of them both after sleep deprivation and in long-term record. As epileptiform discharges we rated spikes, spikes ans slow waves, epileptic K-complexes, spike and waves and poly spike wave-paroxysms. We refer the small number of positive findings in the mobile long-term EEG mainly to the fact that only 3 EEG canals are disponible until now. Therefore on the one hand it is not definitely possible to distinguish sharp waves from sharp transients physiologically appearing in sleep, on the other hand focal EEG-changes often escape from being recorded.

Adolescent↗

PubMed1983

Encephalopathic effect of phenol in rats.

The coma-inducing effect of phenol was studied in normal 300 +/- 50 gm Sprague-Dawley rats. Dose-response curves were developed which showed that one-half the animals became deeply comatose with 540 mumol of intraperitoneal phenol and 100% with 600 mumol. Five stages of encephalopathy were readily distinguished. In stage I, spontaneous activity was noticeably decreased, posture was upright, back-leg control normal, muscle tonus slightly increased, and response to stimuli normal. In Stage V, activity was gone, the rats were deeply unconscious, righting reflex and back-leg control were gone, muscles were completely relaxed, and there was no response to stimuli. With a coma-inducing dose of phenol, spontaneous activity decreased. After 1 min a body tremor developed interspersed with unpredictable jumping, and all four limbs began to shake. Leg control and then the righting reflex were lost by 2 min. Within 5 min rats were deeply unconscious and muscles completely relaxed while shaking of limbs continued until recovery 20 to 60 min later or death. With 480 mumol or less, none of the rats became comatose, but the shaking of limbs was present. The coma-inducing dose of phenol was reduced by 10% to 20% with simultaneous injection of subcoma doses of NH4+ or OA and by 20% to 30% with simultaneous DMDS leads to 2 methanethiol. Conversely, a subcoma dose of phenol reduced the coma-inducing doses of NH4+, OA, and DMDS by approximately 20% to 25%. Thus phenol, which accumulates in human hepatic failure, induces coma by itself in rats and acts synergistically with other hepatic failure toxins.

Animals↗

PubMed1982

[Treatment of bleeding oesophageal varices. Results of combined medical and endoscopically selective intravascular sclerotherapy].

Combining careful medical preparation with subsequent selective intravascular sclerotherapy, one-year survival rate of patients with bleeding oesophageal varices was increased to 90%. Of 41 patients with bleeding oesophageal varices, class Child A-C, none died of bleeding from the varices within the first year after sclerotherapy. Four patients died within the first year, two from liver failure due to severe alcohol abuse, one from liver failure with terminal primary biliary cirrhosis and one from an undiagnosed bleeding duodenal ulcer. Improved results were obtained by two measures: (1) instead of immediate sclerosing at time of diagnosis, initial arrest of bleeding with a Sengstaken tube and, if necessary, administration of vasopressin and improvement in general status by intensive measures to stabilise the circulation and clotting mechanism; (2) selective radiologically controlled intravascular sclerotherapy with a flexible special endoscope 1-2 days after admission. The particular advantage of selective intravascular sclerosing, though it is complicated, lies in the fact that fundal varices and supplying veins to the stomach can also be sclerosed and severe early as well as late complications are exceedingly rare.

Adolescent↗

PubMed1982

[Acute liver failure--therapeutic aspects 1982].

Fulminant hepatic failure is a relatively rare disease. It develops in approximately 400 patients per year in the Federal Republic of Germany after viral hepatitis, toxic hepatitis or hypoxia of the liver. The mortality ranges between 80 - 90%. Therapy must start early. It consists mainly of intensive conservative care. Of the variety of invasive therapeutic measures only baboon liver perfusion and plasma exchange applied early in the disease seem to be of any benefit.

Acute Disease↗

PubMed1982

[Cerebral metastases as the first clinical manifestation of cancer].

A review of the case histories over the 10-year period 1969 to 1978 revealed 80 patients with cerebral metastases. Group 1 comprised 41 patients (43.9% carcinoma of the breast, 12.2% malignant melanoma, 9.8% hypernephroma, 9.8% carcinoma of the colon) in whom the primary site had been established before the manifestation of neurological deficit. Group 2 comprised 39 patients (56.4% bronchogenic carcinoma, 10.1% hypernephroma, 20.5% primary malignancy not identifiable) in whom the neurological symptoms due to metastasis had been first manifestation of malignancy. The sex distribution, age distribution, site of metastasis, cerebral symptoms and the time-lag before the diagnosis were analysed and compared with the literature. The patients in group 1 had an average survival time of 9 months, as compared with 7 months in group 2, from the time of the initial symptoms of cerebral metastasis. The survival time was not essentially different whether surgical or radiotherapeutic measures were undertaken.

Adenocarcinoma↗

PubMed1982

Differential specificity of substrate-attached lectins stimulating spreading of GH3-cells under serum-free, hormone-supplemented culture conditions.

Most mammalian cells are capable of growth in culture only when they are supplied with an appropriate substrate to which they can adhere and spread. To prepare suitable substrates different lectins were attached onto polystyrene tissue-culture dishes after coating with polylysine. GH3-cells (a pituitary-tumor-cell line) were seeded into the culture dishes containing serum-free, hormone-supplemented medium. When succinylated Concanavalin A (s-Con A), which binds specifically to mannose residues, is attached to the surface an extraordinary spreading of GH3-cells is induced within 15 to 20 min after seeding. Other lectins with a different sugar-binding specificity are less effective in inducing cell spreading. However, the cell spreading depends not only on the substrate-attached lectins but also on the hormones used in the proliferation-culture of GH3-cells. Both types of molecules found in the microenvironment of a cell, the matrix-fixed sugar-binding proteins and the diffusive hormones, are responsible for the regulation of the behaviour of the mammalian cell. It is suggested that the interaction of the cell-surface carbohydrates with the plasma-membrane-bound lectins of contiguous cells plays a central role in such processes, especially in in-vivo.

Animals↗

PubMed1982

Contracting striated muscle fibres differentiated from primary rat pituitary cultures.

Whole pituitaries or adenohypophyses alone of adult female Wistar/Furth rats were dissociated into single cells by means of two different enzymic disintegration methods. The single-cell suspension was then seeded out and cultured for up to 8 months in tissue culture dishes with untreated and polylysine-coated surfaces. The cells were cultured in different sera (horse serum, newborn-calf serum, fetal-calf serum, mixtures of horse and newborn-calf serum, and isogenic rat serum) and also in a serum-free, hormone-supplemented medium. When the cells were cultured in medium containing horse serum (15%) plus fetal-calf serum (3%) on polylysine-treated surfaces, cell fusion and the development of myotubes could be observed between day 5 and 10 after seeding and, on about day twenty, the formation of multicellular microstructures could be seen. Myotubes in such microstructures differentiate into muscle fibres, and show spontaneous contraction. Striation is visible both light and electron microscopyically. Such a differentiation into striated muscle cells depends on specific culture conditions: the serum used, the formation of microstructures, and the treatment of the culture dishes. There is apparently no previous report of striated muscle cells found in pituitary cultures.

Animals↗

PubMed1982

Mechanism of sulphate transfer from 4-nitrophenylsulphate to phenolic acceptors via liver cytosolic sulphotransferase.

Phenol sulphotransferase from cat and rabbit liver cytosol has been investigated using 4-nitrophenylsulphate as primary sulphate donor. The first stage of the reaction involves sulphation of cofactor adenosine 3',5'-diphosphate to adenosine 3'-phosphate 5'-phosphosulphate, which in turn acts as sulphate donor for other phenolic acceptors. Adenosine 3',5'-diphosphate is regenerated in this second stage, so that the overall reaction is a sulphate transfer from 4-nitrophenylsulphate to the phenolic acceptor. High acceptor concentrations lead to inhibition of the reaction; very low concentrations give deviation from Michaelis-Menten kinetics. From the kinetic data, a mechanism is suggested in which an enzyme-adenosine 3'-phosphate 5'-phosphosulphate complex is formed in situ, with which the acceptor then interacts to give the final sulphate transfer. The system employed here is useful for the study of phenol sulphotransferase in view of the difficulty in obtaining adequate amounts of adenosine 3'-phosphate 5'-phosphosulphate from commercial sources.

Animals↗

PubMed1981

Changes of the internal organization of the plasma membrane correlated to the regeneration potency of the cell.

Internal organization of the plasma-membrane of rat thymocytes and pituitary tumor cells (GH3) was experimentally altered by low temperature and either changing osmolarity or adding drugs destroying the cytoskeleton. These treatments induce reversible aggregation of intramembrane particles of the plasma membrane. Thin section electron microscopy of the hypotonically shocked cells show all the cell organelles to be extremely swollen and the cytoplasmic space to be rather empty. Returned to physiological conditions, the cells show normal morphological aspects, accompanied by 'normal' permeability properties of the plasma membrane; the aggregation of intramembrane particles is reversed. The proliferation behaviour of GH3-cell is not affected by this treatment. This demonstrates a high regeneration potency of the mammalian cell and leads to the assumption that molecular components which are important for the survival of the cell must be structural (membrane) bound.

Animals↗

PubMed1981

Isolation of surface lectins of GH3 cells from whole cells and isolated plasma membranes.

Lectins localized in the plasma membranes seem to be of special importance for the intercellular interaction mechanisms. We describe the isolation of mannose-binding proteins by Triton X-100 extraction and affinity chromatography on agarose-bound mannose. The isolation procedure was performed with whole GH3 cells as well as with isolated plasma membranes. For the isolation of plasma membranes of GH3 cells a mechanical pump was used for the disruption. After differential centrifugation an enriched plasma membrane fraction was achieved by discontinuous sucrose gradient centrifugation. The whole fractionation procedure was controlled by total balance sheets for the marker enzymes of the different cell organelles. The plasma membrane fraction was further characterized by gel electrophoresis and electron microscopy. The SDS gel electrophoresis patterns of the proteins, resulting from the Triton X-100 extraction and the affinity chromatography, are nearly identical for whole cells as well as for the enriched plasma membrane fraction. Therefore we presume these mannose-specific proteins to be plasma membrane bound, showing the molecular properties of integral proteins and having a molecular weight of Mr 67 000, 57 000, 47 000.

Animals↗

PubMed1981

[Differential diagnosis of chronic hepatitis. Active chronic hepatitis--chronic destructive cholangitis?].

Analysis of the enzyme pattern in 34 patients with liver histology indicating porto-periportal inflammation showed two statistically well differentiated groups: 20 patients with clinical suspicion of early chronic active hepatitis and 14 patients with suspected chronic destructive cholangitis. The course of the disease and the response to immunosuppressive treatment were quite different in the two groups. For differentiation of the early stages of chronic active hepatitis and chronic destructive cholangitis correct interpretation of the enzyme pattern is of great importance. It is also relevant for the decision to use long term immunosuppressive treatment.

Cholangitis↗

PubMed1981

[Lactate acidosis in the cerebrospinal fluid as a prognostic parameter of malacic cerebral insult (author's transl)].

The concentrations of lactate and pyruvate were determined in 111 CSF and blood samples. The CSF and blood chemistry of 43 patients with a lateralized ischaemic cerebral insult was compared with that of a control group of 18 patients. The first tests were carried out within 24 to 48 hours and 50 follow-up determinations were undertaken in the cerebral insult group. The patients were classified according to their level of consciousness (lucid-somnolent-soporous-comatose). Covariance analysis revealed a distinct relation between the CSF chemistry and the level of consciousness of the insult patients; accordingly, a continuous increase in the lactate level from 1.54 mmol/l to 3.48 mmol/l and in the pyruvate level from 0.11 mmol/l to 0.21 mmol/l was noted. Spearman's correlation analysis also pointed to a statistically significant correlation between decreasing levels of consciousness and the CSF lactate/pyruvate quotient. The increase in the CSF/blood quotient of lactate from 1.17 to 2.14, corresponding to the decrease in the level of consciousness, also indicates that during the early stages of the disease, cerebral tissue hypoxia is reflected in the CSF rather than in the blood. Further subdivision of the groups according to whether the patients survived or died, showed that the critical maximum concentrations from the prognostic point of view are 2.74 +/- 0.19 mmol/l in the case of CSF lactate, 0.186 +/- 0.017 in the case of CSF pyruvate and 1.92 +/- 0.65 for the CSF/blood quotient of lactate. None of the patients with a CSF lactate level of 3.1 mmol/l or more survived the ischaemic cerebral insult. Thus, the above-mentioned parameters are to be regarded as important indicators of the threat to the patient's life.

Acid-Base Equilibrium↗

PubMed1981

Selective cell culture of brain cells by serum-free, hormone-supplemented media: a comparative morphological study.

We cultured single cell suspensions derived from enzymatically digested rat and mouse brains in the serum-free, hormone-supplemented media originally established for culturing glioma (C6) and neuroblastoma cell lines (B104). We succeeded in selecting different cell types by varying the hormones added to the culture medium. In addition to the medium the attachment factors used for coating the culture dishes proved important for the establishment of a selective culture system. In a comparative morphological study we show that different particular microenvironmental conditions determine the growth and/or survival of different cell types of dissociated brain cells.

Animals↗

PubMed1981

Properties of agarose-encapsulated adsorbents. II. Elimination of endogenous and exogenous phenolic compounds from human serum.

Phenolic compounds derived from the amino acid tyrosine are endogenous toxins, which are believed to be involved in the pathogenesis of hepatic coma. There are also xenobiotic phenolic substances, such as p-hydroxy-acetanilide (paracetamol or acetaminophen), which can lead to serious complications if taken in an overdose. In both cases, a drastic therapeutic measure such as haemoperfusion may be indicated to eliminate the toxin from the blood. In the present work, human serum has been dosed with the phenolic compounds of immediate relevance in exogenous and endogenous intoxication, and the effectiveness of various adsorbent materials for the elimination of the toxins from the serum has been investigated. Resins and charcoal in the native state have been compared with those encapsulated into large agarose beads, a process which improves the haemocompatibility and thus the practicability of the adsorbents. A certain degree of specificity has been observed. Whereas phenolic acids are adsorbed quite effectively onto the strongly basic ion exchange resins of the Dowex 1X type, particularly 1X8 or 2X8, phenol or paracetamol are less effectively eliminated. In contrast to many other classes of toxin, the Amberlite XAD-type resins are ineffective for all the phenolic substances investigated. Charcoal is the most effective adsorber in most cases, particularly when encapsulated in powder form into agarose beads.

Absorption↗

PubMed1981

Properties of agarose-encapsulated adsorbents. I. Adsorption of digoxin from human serum.

The elimination of the cardioactive steroid, digoxin, from human serum by a range of adsorbent phases has been investigated. In the native state, the uncharged resins of the Amberlite XAD-type proved more effective than the ion-exchange resins, Dowex 1X, or active charcoal. Of the materials tested, Amberlite XAD-8 is by far the best suited resin for haemoperfusion in cases of digoxin overdose, whereby the less efficient XAD-4 is more commonly employed at present in clinics. In order to improve the haemocompatibility of the adsorbent materials, the technique of encapsulation into large agarose beads has been employed. In contrast to the effects observed with many other classes of xenobiotics, encapsulation into agarose beads results in a considerable loss of adsorptive capacity of digoxin by Amberlite XAD-8. The poor performance of active charcoal in form of granules can be improved by an order-of-magnitude using charcoal powder encapsulated in agarose. Thus, the latter material, or uncoated XAD-8 resin should be considered as a better alternative to materials in current use for extracorporeal detoxification in cases of digoxin overdose.

Anion Exchange Resins↗