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Biomedical subjects

K H Schmidt

Publications and source records attributed to K H Schmidt.

At least 109 records · Page 6Linked to original sources
PubMed1984

[T-proteins of Streptococcus pyogenes. IV. Isolation of T1-protein using affinity chromatography on immobilized fibrinogen].

T-protein of Streptococcus pyogenes, type 1 (strain SF 130 Griffith) was extracted by enzymatic treatment of the cells with trypsin and partially purified by ion exchange chromatography on DEAE cellulose and gel chromatography on ultrogel ACA 44. The crude T protein still showing serologically type specific and cross reactions finally was applied to a fibrinogen sepharose column. Components eluted with the neutral buffer (0.05 M phosphate, 0.2 M NaCl, 0.02% NaN3, pH 7.0) reacted serologically in the same manner as the crude T protein. By using 0.1 M citrate, 6 M urea pH 3.0 buffer a type specifically reacting protein (T1-TRYP-F) was eluted from the fibrinogen column. T1-TRYP-F showed identical precipitation lines with the recently characterized T1-protein (T1-TRYP-I) purified by immunochromatography on type specific anti-T antibodies. Comparison of the SDS-patterns of T1-TRYP-F and T1-TRYP-I revealed a less complex molecular size subunit structure for the fibrinogen binding T1-TRYP-F (two bands of 60000 and 70000) as found for T1-TRYP-I, which showed serologically active peptides between 30000 to about 500000. It is discussed that T protein also may be linked covalently with fibrinogen receptors as it has been reported for M protein.

Amino Acids↗
PubMed1984

Comparative studies on surface hydrophobicity of streptococcal strains of groups A, B, C, D and G.

Cell surface hydrophobicity of group A, B, C, D and G streptococcal strains has been studied and compared in a new test based on the fact that the degree of bacterial aggregation in ammonium sulphate depends on amphiphilic surface antigens. M-positive group A strains showing good growth in normal human blood aggregated in the standard salt aggregation test at very low concentrations of ammonium sulphate, while M-negative strains, which were killed in normal human blood, usually aggregated at high salt concentrations. Agents such as 2 M-KSCN, 2 M-guanidine. HC1 or 2 M-urea decreased the aggregation of the M-positive strains in the salt aggregation test while non ionic detergents such as Tween 20 (1%, w/v) and ethylene glycol (2 M) did not affect cell aggregation. Binding of fibrinogen and albumin resulted in a decrease of surface hydrophobicity of the group A M-positive strains. Group B strains possess a hydrophilic surface character and did not aggregate, while group C and G strains behaved in the salt aggregation test like M-negative strains of group A streptococci. Group D strains did not aggregate even at high ammonium salt concentrations. The results are discussed in relation to the influence of lipoteichoic acid and other surface antigens on strains of the various groups, and it is suggested that M protein and possibly also other surface proteins contribute to the high surface hydrophobicity of group A strains.

Ammonium Sulfate↗
PubMed1984

Comparative studies on the oxidative processes during phagocytosis measured by luminol-dependent chemiluminescence.

Four different methods, using luminol-enhanced chemiluminescence, are described for assessment of the oxidative processes associated with the phagocytosis of opsonized zymosan by granulocytes. The techniques described in the literature using whole blood as a substrate gave unreliable results due to quench effects of contaminating red blood cells, unpredictable serum interferences, or varying ratios of granulocytes and zymosan. In order to avoid these side effects, rapid and simple methods for the isolation of the granulocytes were applied, e.g. lysis of erythrocytes by ammonium chloride, or the isolation of granulocytes on a percoll gradient. The latter procedure proved to be reliable, simple and sufficiently quick for a routine application.

Ammonium Chloride↗
PubMed1984

[The value of arthroscopy in the diagnosis of knee injuries].

Arthrographic and arthroscopic findings of traumatized knee joints were compared by operation. It was found that endoscopic examination, particularly in case of damage to joint cartilage and cruciated ligaments, is superior to arthrographic examination. The lesions of meniscus could not always be detected radiologically. Hence, whenever there is a suspicious knee joint damage, arthroscopy should be performed liberally.

Adolescent↗
PubMed1984

[Experience with the use of an external fixator in patients with multiple injuries].

The authors report on experiences with fixateur extern according to Raoul Hoffmann in 110 open fractures of second-degree and third-degree severity. The patient material comprised 90 patients, of which a total of 71 (79 per cent) had polytraumas. It was shown that good results can be expected if fixateur extern is applied immediately. The advantages of good positioning and care of soft parts are emphasized. A detailed discussion is devoted to the specific problems of polytraumatized patients with second-degree and third-degree open fractures.

Adult↗
PubMed1983

Studies on the mechanism of bile salt-induced liposomal membrane damage.

The damage of phosphatidylcholine membranes by bile salts such as cholate, deoxycholate (DC), chenodeoxycholate (CDC), ursodeoxycholate (UDC), as well as their glyco- and tauroconjugates, and lithocholate (LC) were studied. The permeabilities of liposomes differing in size (700 and 1,700 A in diameter) were determined at increasing bile salt concentrations. The release of entrapped raffinose (3H) (MW: 594) or inulin (3H) (MW: 5,000) was measured by pelleting of the liposomes and subsequent determination of the radioactivities in the supernatant. The release of these uncharged volume markers of different size points to a formation of membrane leaks increasing in size with increasing bile salt concentration. Determination of the membrane damaging threshold concentrations of bile salts demonstrated a higher stability of the smaller liposomes. Incubation of the smaller liposomes with increasing DC concentrations results in a successive substitution of lecithin by DC. The predominantly DC-containing vesicles are of remarkable stability against higher DC concentrations. The damaging properties of bile salts increase with decreasing number of hydroxy groups, with the exception of UDC and its conjugates which are much less membrane toxic than the other dihydroxy bile salts. Conjugation with glycine or taurine slightly enhances the membrane toxicity of bile salts with the exception of UDC. Sulfation of the 3-alpha-hydroxy group of LC reduces the damaging effect to about 10%.

Animals↗
PubMed1982

Effectiveness of behavioral treatment methods compared to pharmacological therapy and self recordings of blood pressure in essential hypertensives (preliminary report).

48 essential hypertensives were randomly assigned to (1) a behavioral treatment (n = 20), (2) a pharmacological treatment (n = 20), or (3) self recordings of BP (n = 8). Group 1 and 2 showed during 1 year of therapy comparable significant decreases of systolic and diastolic BP, whilst group 3 showed significant increases after 3 months of therapy.

Behavior Therapy↗
PubMed1981

The present status of research in burn toxins.

Modern intensive care combined with current improvements in the specific, systemic and local therapy of burns has delayed the mortal effects of severe burns. Nor has there been any significant improvement in this mortality during the last decade. The occurrence of uncontrollable infection and sepsis due to gram-negative bacteria or fungi as the basic cause of death was not a satisfactory explanation. So, progress should only be expected from a new concept in burn treatment. This new concept should be to view the burn disease as being caused by toxic factors induced by thermal injury to the skin. Electron-microscope studies in mice and rats have revealed similar mitochondrial alterations in hepatocytes after either a sublethal controlled burn injury or an intraperitoneal application of an equivalent dose, of a cutaneous burn toxin. The intraperitoneal injection of different amounts of the burn toxin indicated, that the extent of the mitochondrial changes correlated directly with the dose of toxin. Investigations of liver metabolism suggested an inhibition of the oxygenation chain. The incubation of isolated liver cells together with the burn toxin demonstrated by scanning electron microscopy a direct cytotoxic effect of the burn toxin. In animal tests the pathogenic effect of the burn toxin could be prevented by treatment with an antitoxic IgG generated in sheep. The fatal sepsis of severely burned patients is the consequence of a decreased host defence against infections, which is caused by a primary and general toxic alteration of the whole organism. One important aspect of treatment should therefore be the elimination of burn toxins. To achieve this management should include primary excision of the burns, local application of nonabsorbable protein-complex-binding substances and specific passive immunotherapy with an antitoxic IgG.

Adenosine Diphosphate↗
PubMed1981

Interaction of streptococcal cell wall components with fibrinogen. I. adsorption of fibrinogen by immobilized T-proteins of streptococcus pyogenes.

Immobilized streptococcal T1-, T3- and T4-proteins to AH-Sepharose 4B were tested for their ability to absorb human fibrinogen. Purified fibrinogen and plasma samples were used for affinity chromatography. T1-protein was able to retain specifically fibrinogen from plasma. T4-protein bound fibrinogen in a similar manner, but it was not as specific as T1-protein. T3-protein failed to bind purified fibrinogen as well as fibrinogen from plasma. Adsorption of fibrinogen was accomplished using a 0.05 M phosphate/0.2 M NaCl/0.02% NaN3/pH 7.0 buffer system followed by elution with 0.05 M PO4/1 M NaCl/0.02% NaN3 to remove non specifically bound components. Retained components were eluted with 8 M Urea/0.025 M NaOAc, pH 5 and the fractions analyzed for fibrinogen content by SDS polyacrylamide gel electrophoresis. The presence of fibrinogen was determined by observations of the characteristic A alpha, B beta and gamma chain bands.

Adsorption↗
PubMed1981

Urinary oxalate excretion after large intakes of ascorbic acid in man.

The influence of high dose intake of ascorbic acid on the urinary excretion of oxalate was investigated in five healthy male volunteers. Oxalate was measured by a newly developed specific method using isotachophoresis. With intakes of 10 g ascorbic acid (5 X 2 g daily for 5 days; four subjects) mean urinary oxalate excretion was enhanced from about 50 mg to 87 mg (range 60 to 126 mg) per day. At least 25% of the ascorbic acid was absorbed and excreted with the urine. On discontinuing ascorbic acid administration, oxalate excretion returned to baseline values within 24 h. The time-course of oxalate excretion revealed that following the 3rd dose of 2 g ascorbic acid a plateau in urinary oxalate excretion was reached (0.6 microgram ml-1 min-1) which was not exceeded despite additional 2-g doses of ascorbic acid. On termination of ascorbic acid administration the oxalate excretion rate remained at this level for a further 6 h and then decreased to prestudy rates. No effect of high-dose ascorbic acid ingestion was found on the daily urinary excretion of creatinine, uric acid, and inorganic phosphate. Calcium excretion was slightly reduced. In comparison to the large amounts of ascorbic acid ingested, the increase in urinary oxalate excretion as measured by isotachophoresis in these healthy male volunteers was very low, and is thus similar to the change in urinary content of oxalate which results from consuming normal diets.

Ascorbic Acid↗
PubMed1981

[T-proteins of Streptococcus pyogenes. III. Communication: purification of T-proteins extracted with trypsin, pepsin and C-phage-associated lysin by means of immunochromatography (author's transl)].

T-proteins of Streptococcus pyogenes type 1 were extracted by enzymatic treatment of cells with trypsin, pepsin or C-phage-associated lysin and subsequently purified by ion exchange chromatography on DEAE cellulose as well as by immuno-adsorption on immobilized anti-T-type 1 antibodies. Immunochromatographical purified T1-proteins which were extracted by the different enzymes showed different properties in immuno-electrophoresis, SDS-electrophoresis and amino acid composition although a serological reaction of identity was found in Ouchterlony precipitation. Tryptic and peptic digestion was efficient for extraction of T protein while the extraction with C-phage-associated lysin was unsuitable for isolation of T-protein. The release of T-protein after treatment of cells with this lysin was very low and the preparation purified by this way exhibited cross-reaction with non-absorbed antisera of other types.

Bacterial Proteins↗
PubMed1981

[Test of efficacy of an oxalate-binding anion exchanger Colestid in healthy subjects for use in idiopathic calcium-oxalate urolithiasis].

Sodium oxalate (402 mg) was administered in a single dose to 10 healthy volunteers receiving a controlled diet. Half the group received 3 times 10 g Colestid and the other half 4 times 2 g Andursil. On the 5th day the oxalate load was repeated. Urine was collected within 32 hours following oxalate application in 8 fractions. In each fraction the levels of oxalate, calcium, phosphate and uric acid were determined. The amount of oxalate, phosphate and uric acid measured in the group receiving Colestid was lower in all fractions. Peak excretions of oxalate found in unmedicated volunteers were suppressed following oxalate load. In the group receiving Andursil, only the excretion of phosphate was decreased. The results presented suggest that Colestid may be promising in the prevention of calcium-oxalate-urolithiasis.

Anion Exchange Resins↗
PubMed1980

[T-proteins of Streptococcus pyogenes. II. Communication: Preparation of specific immunoadsorbents for isolation of anti-T-antibodies and investigations of the T4/24...pattern (author's transl)].

The T4-antigen(s) in Streptococcus pyogenes standard type strains of the T4/24...pattern was (were) investigated in regard to the uniformity or diversity of the antigen(s) in this T-complex. Tryptic T-extracts of types 4, 24, 26, 28, 29, 46, 48, 60 were purified by ion exchange chromatography on DEAE-cellulose. Anti-T4-antibodies were isolated by immunoadsorption chromatography on AH-sepharose linked T4-antigen. Purified T4-antigen showed in SDS-electrophoresis a similar multiple molecular size structure as T1-antigen described earlier. Comparative serological studies of T-antigens of types 4, 24, 29 and 46 revealed reactions of identity to anti-T4-antibodies in Ouchterlony tests. Extracts of types 26, 28, 48 and 60 did not precipitate with anti-T4-antibodies, but types 28 and 48 showed crossreaction to the relevant antisera (anti-T28 and anti-T48, resp.) obviously caused by traces of R-28 antigen in both antigen preparations. Strains of the types 4, 24, 29, 46, 48 and 60 were agglutinated by anti-T4-antibodies. The reaction could be inhibited by T4-antigen. The strains of type 26 and 28 used in our experiments did not contain T4-antigen. Agglutination as well as immunoprecipitation reactions with specific antibodies prepared by immunochromatography proved the existence of common T4-antigenic determinants in type 4, 24, 29, 46, 48 and 60.

Animals↗
PubMed1980

[T-proteins of Streptococcus pyogenes. I. Communication: Preparation of a serological type specific T1-antigen by ion exchange chromatography and its characterization (author's transl)].

The T-protein of Streptococcus pyogenes type 1 was trypsin-extracted and subsequently purified by ion exchange chromatography on CM and DEAE cellulose. Fractionation on CM cellulose by stepwise increase of the pH did not result in separation of type specific material from cross reacting components. The bulk of serologically active material was eluted at pH 5.6. On DEAE cellulose a type specific fraction was eluted with 0.05 m phosphate buffer, pH 8.2. A second fraction eluted with 0.25 m NaCl in the same buffer contained type specific as well as cross reacting material. Molecular weight distributions of type-specific T-protein were studied by gel chromatography on Ultrogel ACA44 and Biogel A 1.5 m. A multiple size subunit structure of T-protein was found and supported by SDS electrophoresis. Molecular weights of fragments serologically active in double diffusion were detected in a range of 37 000 to more than 200 000 Dalton. The isoelectric point was determined as to be pH 4.5. The purified T-protein was found to be free of cystein and of the amino sugars N-acetyl-glucosamine and N-acetyl-muramic acid.

Amino Acids↗