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S Zimmermann

Publications and source records attributed to S Zimmermann.

At least 19 recordsLinked to original sources
PubMed1992

Restriction fragment length polymorphisms associated with alpha-hemolysin determinants are correlating with the expression of alpha-hemolysin in strains of Escherichia coli.

Three different phenotypes of hemolysis on blood-agar were detected when 58 isolates of Escherichia coli were investigated for alpha-hemolysin synthesis. In strains with chromosomally encoded alpha-hly genes, phenotype I (large and clear hemolysis zones) corresponded with high hemolytic activity and with a 17.2 kb size BamHI restriction fragment hybridizing with an alpha-hly-specific gene probe. Phenotype II (small and turbid hemolysis zones) was associated with low hemolytic activity and generally with a 12.8 kb size hybridizing BamHI restriction fragment. An intermediate phenotype (type I/II) was found in a few strains with moderate hemolytic activity. This correlation between hemolytic phenotype and activity was not found in E. coli carrying alpha-hly plasmids. Type I strains differed from all others in the promotor region of their 17.2 kb size BamHI fragment associated chromosomal alpha-hly determinant. The relation between hemolytic phenotype and DNA hybridization pattern was found in unrelated E. coli isolates of human and animal origin. An association of alpha-hemolysin with other virulence factors was found in most strains of all three phenotypes.

Animals↗
PubMed1992

Polycystic ovary syndrome: lack of hypertension despite profound insulin resistance.

It has been hypothesized that insulin resistance and hyperinsulinemia contribute to the development of arterial hypertension. To further investigate this relationship, we compared arterial blood pressure in controls and women with polycystic ovary syndrome (PCO), an insulin-resistant state. Fourteen PCO women and 18 normal control women of similar age, body mass index, and race were studied. Plasma glucose and insulin levels were determined in an oral glucose tolerance test. The insulin sensitivity (SI) index was determined by the minimal model method. Systolic and diastolic blood pressure were measured by 24-h ambulatory monitoring. Left ventricular mass was assessed by echocardiography. The two groups had comparable fasting glucose levels, but the 2-h postload glucose was higher in PCO (8.0 +/- 0.5 vs. 5.6 +/- 0.3 mmol/L; P less than 0.001). Compared to controls, PCO women were significantly more insulin resistant by fasting insulin, 2-h insulin concentrations, and SI (28.3 +/- 6.7 vs. 68.3 +/- 10.0 min-1/nmol.mL; P less than 0.01). Average ambulatory systolic (121 +/- 2 vs. 118 +/- 2 mm Hg) and diastolic (76 +/- 2 vs. 73 +/- 2 mm Hg) blood pressures were similar for PCO and control women. No difference was found in left ventricular mass. Therefore, despite profound insulin resistance and hyperinsulinemia, women with PCO do not have increased arterial pressure or left ventricular mass.

Adult↗
PubMed1991

Identification of valine/leucine/isoleucine and threonine/alanine/glycine proton-spin systems of Escherichia coli adenylate kinase by selective deuteration and selective protonation.

Adenylate kinase from two types of Escherichia coli strains, a wild-type and a leucine-auxotrophic strain, was purified. On the one hand, growing the leucine-auxotrophic bacteria on a medium containing deuterated leucine yielded E. coli adenylate kinase with all leucine residues deuterated. On the other hand, by growing the wild-type bacteria on deuterated medium with phenylalanine, threonine and isoleucine present as protonated specimens, 80% randomly deuterated enzyme with protonated phenylalanine, threonine and isoleucine residues could be prepared. Use of these proteins enabled identification of the spin systems of these amino acid residues in the n.m.r. spectra of the protein.

Adenylate Kinase↗
PubMed1991

Effects of endothelin-1 in the isolated heart in ischemia/reperfusion and hypoxia/reoxygenation injury.

The effects of the vasoconstrictor peptide endothelin-1 were examined in the isolated heart during hypoxia, reoxygenation and reperfusion. Isovolumic rat hearts were perfused with Krebs-Henseleit buffer at constant pressure. Cumulative dose-response curves were obtained for endothelin-1 boluses of 0.04 to 400 pmol in five groups of hearts. Coronary flow declined with increasing dosages and was almost abolished at 400 pmol in control hearts. In hearts subjected to mild hypoxia (perfusate PO2 approximately 150 mmHg), the constrictor effect of endothelin-1 was attenuated at moderate dose compared to control hearts (4 vs. 16% flow reduction at 40 pmol; P less than 0.05). The constrictor effect was unaltered in hearts subjected to either 60 min of severe hypoxia (PO2 approximately 35 mmHg) followed by reoxygenation or to 10 min of total ischemia followed by reperfusion (stunning). When hearts were reperfused following 30 min of total ischemia (irreversible injury), the constrictor response to endothelin-1 was potentiated compared to control (e.g. 36 vs. 16% flow reduction at 40 pmol; P less than 0.05). We conclude that endothelin-1 is a potent coronary constrictor in hypoxic, reoxygenated and reperfused heart. The constrictor effect is attenuated during hypoxia, most likely due to the presence of counteracting vasodilator metabolites. During reperfusion, the constrictor effect is unchanged in stunned myocardium, but is augmented in irreversibly injured heart, due to either increased endothelin-1 binding sites or loss of counteracting vasodilator mechanisms such as prostaglandins and/or endothelium-derived relaxing factor.

Animals↗
PubMed1991

Characteristics of alpha-hemolytic strains of Escherichia coli isolated from dogs with gastroenteritis.

Twenty-four hemolysin producing (Hly+) strains of Escherichia coli isolated from dogs with gastroenteritis were investigated for their virulence markers and their phenotypic properties. The strains were distributed over eleven known E. coli O-serogroups and most of them were heterogeneous for their phenotypes. All strains were found to produce alpha-hemolysin which was detected by Southern hybridization and colony immunoblotting using a specific gene probe and a monoclonal antibody. Eight strains were carrying plasmids encoding alpha-hemolysin sequences (hly-plasmids) and 16 strains carried chromosomal hly-determinants. Twelve of the strains showed enterotoxic activities which were tested for in different assays. Among these, three O42:H37 and two O70:H-strains carrying hly-plasmids were found to harbour other plasmids encoding the heat-stable enterotoxin STA1. The other seven strains showing enterotoxicity in the ileal loop or the suckling mouse assay were negative for STA1, STA2, or LT. None of the 24 strains were positive for invasiveness or for production of Vero (Shiga-like) toxins. The production of alpha-hemolysin was closely associated with the production of cytotoxic necrotizing factor (CNF), which was detected in 17 of 24 strains. Of these, 16 elaborated CNF1 and one strain produced an unknown CNF type. Surprisingly, all strains carrying ST-plasmids and six of eight strains carrying hly-plasmids were negative for CNF. Thus, in canine E. coli strains CNF production seems to be closely associated with production of chromosomally encoded alpha-hemolysin whereas hly-plasmids are more often associated with ST-producing, CNF negative isolates.

Animals↗
PubMed1991

[The evaluation of the adhesive properties of dental materials by using radioactive-labelled bacteria].

Dental materials with different surfaces were incubated with 111In-oxine-labelled bacteria Streptococcus mutans 20 min respectively 2 h, 6 h and 24 h. To determine the amount of the bacteria accumulated on the specimens we measured the radioactivity with a scintillation counter. The same measuring was done after decontamination by the help of ultrasonication. The comparison of activities shows that different dental material surfaces adhere different amounts of bacteria. The adhesive properties are material and time dependent, but the surface processing has a lower influence on the bacterial adherence. The lowest degree of bacterial adherence has the cobalt base alloy Gisadent KCM 83. On the other hand the highest remaining activity was found after decontamination of cobalt base alloy and PMMA resin Kallocryl A.

Adhesiveness↗
PubMed1990

[Drug taking behavior of internal medicine inpatients].

There are only few publications about patient compliance in in-patients. The compliance of 134 female patients of a common hospital was detected after prescription of riboflavin tablets. Over a period of 10 days four examinations of the urine for signs of fluorescence were performed. 24% of the in-patients were noncompliant. Patients aged over 70 years or with chronic diseases like diabetes or hypertension were seen to have a good compliance compared with younger ones or patients without these diseases. In-patients with psychiatric or psychosomatic disorders were more incompliant than the other ones. In this group the intake must be controlled. A large number of prescribed tablets negatively influenced the compliance but the frequency of intake did not adversely affect the compliance. The history of individual patient compliance will indicate the future compliance. The results show that compliance should be taken into account in in-patients care especially according to a successful therapy.

Adult↗
PubMed1990

Clonal diversity and virulence factors in strains of Escherichia coli of the classic enteropathogenic serogroup O114.

Eighty-eight Escherichia coli strains of the enteropathogenic (EPEC) group O114 that were isolated from humans and animals in geographically different places and over more than 30 years were examined for virulence markers, O:H serotypes, and for electrophoretic types by multilocus enzyme electrophoresis. Four major genetically tightly related clusters of strains showed close correlation between electrophoretic types and other phenotypic characters. Cluster I contained 35 EPEC class II strains of serotypes O114:H9 and O114:H- and 5 enterotoxigenic E. coli belonging to O114:H21 and O114:H49. Clusters II and III comprised 36 O114:H4, O114:H32, and O114:H- strains; most were of doubtful pathogenicity except one Verotoxin-positive O114:H4 strain isolated from a human with diarrhea. Cluster IV contained 9 classic EPEC strains of serogroup O114:H2 that were characterized by localized adherence to HEp-2 cells and by the EPEC adherence factor.

Alleles↗
PubMed1990

Effects of endothelin-1 in the isolated heart under ischemic and cardioplegic conditions.

We examined the effects of the vasoconstrictor peptide endothelin-1 in isolated hearts under ischemic and cardioplegic conditions. Isolated isovolumic rat hearts were perfused with Krebs-Henseleit buffer at constant pressure. Cumulative dose-response curves were obtained for endothelin-1 boluses of 0.04-400 pmol in four groups of hearts. Coronary flow decreased with increasing dosages and was almost abolished at 400 pmol in control hearts perfused at a constant pressure of 100 mm Hg. In hearts made ischemic by reducing coronary perfusion pressure to 35 mm Hg, thus reducing coronary flow by 76%, the constrictor effect of endothelin-1 was well preserved. The endothelin-1 dose-response curve was unaltered when hearts were perfused with buffer containing 30 mM KCl to abolish mechanical activity without reducing extracellular Ca2+ concentration. A fourth group of hearts was perfused with Ca2(+)-free buffer, thus eliminating the source of extracellular Ca2+ as well as mechanical activity. In this group, the constrictor response to endothelin-1 was largely, but not completely, abolished, with a maximal constrictor effect of only 19% as opposed to 87% in control hearts. We conclude that in isolated rat heart endothelin-1 is a potent coronary constrictor under ischemic perfusion conditions and that absence of mechanical activity does not affect the action of endothelin-1, for which the presence of extracellular Ca2+ is essential. The small residual constrictor response with Ca2(+)-free perfusion is probably due to release of Ca2+ from intracellular stores.

Animals↗
PubMed1989

Close association of verotoxin (Shiga-like toxin) production with enterohemolysin production in strains of Escherichia coli.

Sixty-four verotoxin-producing (VT+) Escherichia coli strains were analyzed for VT1- and VT2-specific DNA sequences and for production of hemolysin. Strains of human origin were of the following serotypes: O157:H7 or H-, O111:H8 or H-, O26:H11, O114:H4, and rough:H7. Strains of serotypes O157:H7, O113:H21, O116:H21, and rough:H- were from cattle, while those of serotype O139:K12:H1 were from pigs. All 64 isolates carried either VT1 or VT2 or both genes. Sixty of the strains (93.8%) were hemolytic (Hly+). The three O139:K12:H1 strains examined produced alpha-hemolysin, as shown by their reaction with the alpha-hemolysin-specific monoclonal antibody h2A and by DNA hybridization with an alpha-hly gene probe. The remaining 57 Hly+ strains (95%) produced a different type of hemolysin (enterohemolysin), which is genetically and serologically unrelated to alpha-hemolysin. The two types of hemolysin are further distinguished by the appearance of the lysis zone on blood agar and by the time interval for the detection of hemolysis. In contrast to alpha-hemolysin, enterohemolysin can be detected only on blood plates containing washed erythrocytes. The frequent association of enterohemolysin with verotoxin production (89%) makes it useful as an epidemiological marker for rapid and simple detection of potential VT+ E. coli.

Animals↗
PubMed1988

[The clinical use of polyvalent immunoglobulin preparations].

A short survey is given of the indication for the use of polyvalent human immunoglobulin (human gamma globulin). The effect for the prophylaxis in hepatitis A is ascertained. The indication in the primary antibody deficiency syndrome is obligatory. In the secondary antibody deficiency syndrome with a moderate decrease of the immunglobulins as a rule a substitution is not indicated. A general prophylaxis or adjuvant therapy in surgical interventions, in polychemotherapy and in the framework of an intensive therapy without presence of an immune defect is to be refused. If in individual cases in sepsis, burn diseases or therapy-refractory infections additionally immunoglobulins are given, this must be done in high dosage. The modulation of immune reactions in autoimmunopathies is a new indication. Hyperimmunoglobulin and monoclonal antibodies will in future determine the immunoglobulin therapy.

Autoimmune Diseases↗
PubMed1988

Two-dimensional NMR studies of the porcine muscle adenylate kinase.

Porcine adenylate kinase was subjected to one- and two-dimensional proton NMR studies in order to identify amino acid spin systems and obtain sequence-specific resonance assignments. With a combination of results from a map of side-chain distances resulting from the refined X-ray crystallographic data and nuclear Overhauser effect spectroscopy (NOESY), assignments are suggested for all the aromatic spin systems.

Adenylate Kinase↗
PubMed1988

Enterohemolysin, a new type of hemolysin produced by some strains of enteropathogenic E. coli (EPEC).

42 Escherichia coli O26 strains which had been isolated at geographically different places and over a long time period were examined for hemolysin synthesis. 17 of these were found to be hemolysin-negative, nine strains were found to produce plasmid encoded alpha-hemolysin and 16 strains were shown to produce a phenotypically different hemolysin. This new type of hemolysin was called enterohemolysin and found to be genetically and immunologically non-related with the already described E. coli alpha-hemolysin. Enterohemolytic E. coli were not found in feces of 200 healthy infants under the age of two years. However, four E. coli O111 strains, one O121:H- and one O25:K5:H- strain, all from infants with diarrhoea were also enterohemolysin producers.

Animals↗
PubMed1987

[Variation in nocturnal blood pressure behavior in stage III (WHO) hypertension--a case report].

In some cases of hypertensive men the authors obtained 24-hour blood pressure profiles by easy non-invasive technique (Mercury manometer) and under the usual atmosphere and activities of a hospital. The control Group, 32 normotensive men, showed a normal circadian blood pressure variability with systolic acrophases at 10.00 h and 16.00 h and a bathyphase around 3.00 h. The diastolic blood pressure had a smaller variability. One patient with essential hypertension stage II (WHO), case 1, kept the normal day-night rhythm. By case 2, a man with essential hypertension stage III (WHO), the authors refer to the possibility of considerable differences of blood pressure behaviour during the night in cases of severe hypertension in contrary to normal blood pressure variability. After a supplementary fourth medication this patient showed a significant decrease of blood pressure during the night. Nevertheless he kept his acrophase at night. The recording of day-night profiles of blood pressure seems to be useful in relation to the judgement of classification of severity, of the mode of anti-hypertensive medication and of the success in therapy.

Antihypertensive Agents↗
PubMed1986

Characterization of hemolytic strains of Escherichia coli belonging to classical enteropathogenic O-serogroups.

147 isolates of enteropathogenic E. coli (EPEC) belonging to eleven different O-serogroups were examined for hemolysin-synthesis. Hemolysin-producing (Hly+) strains were found at high frequency in O-serogroups 26 and 114 and at low frequency in O-serogroup 126. The hemolytic activities of EPEC strains of different serogroups were found to be low when compared to Hly+ non-EPEC E. coli strains of different origins. Similarities between the hly determinants of EPEC strains and the hly region of an uropathogenic strain were detected by DNA-hybridization. By this method hly genes of EPEC strains belonging to O-serogroups 114 and 126 were localized on the bacterial chromosome. The hly determinants of O26 strains were localized on 100 +/- 5 MD size conjugative plasmids. The hly plasmid pEO5 of the O26 strain C4115 was transferred by conjugation into an E. coli K12 recipient and found to be stable inherited. The hemolytic activity of the transconjugant was comparable to the wildtype O26 donor. The plasmid pEO5 was found to be different in size, compatibility and hemolysin expression from a number of described hemolysin-plasmids.

Child↗
PubMed1986

[Immunomodulation with apheresis technics].

The use of apheresis therapy (plasmapheresis/plasmafiltration or cytopheresis) was successful in numerous immunological diseases. Autoimmune and immune complex diseases as well as paraproteinemias with hyperviscosity syndrome (M. Waldenström, plasmocytoma) are the main indications. The several modifications of apheresis and its indications are outlined, and possible immune regulatoric effects of apheresis therapy are discussed. Finally this paper refers to beginning changes from unspecific to more selective methods of apheresis (cascade filtration, cryofiltration, immunoadsorption, enzymatic degradation, continuous electrophoresis) and its significance for clinical and experimental immunology.

Adjuvants, Immunologic↗