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Biomedical subjects

G Schmidt

Publications and source records attributed to G Schmidt.

At least 235 records · Page 13Linked to original sources
PubMed1991

Increased accumulation of plasma albumin in the extracellular space of the heart during hypoxia.

The question which was investigated in this study is whether an augmented capillary protein permeability occurs during hypoxia, an effect which might worsen the supply conditions of the tissue during O2 deficiency. Anaesthetized and thoracotomized rats and mice received an i.v. injection of lissamine-rhodamine B200 (RB200)-conjugated albumin and were then ventilated with a gas mixture of 11 vol % O2 for 3 min. At the end of this period the heart was rapidly frozen and histological sections were subsequently scanned for changes in the distribution of labelled albumin. In the control hearts 4.6% (rats) and 4.5% (mice) of the microscopic fields showed penetration of labelled albumin into the extracellular space of the heart. Hypoxia, however, proved to induce an increased shift of plasma albumin into this space in localized areas with signs of increases in the extracellular volume in these areas. The changes in distribution were observed in 26.0 and 35.8% of fields scanned in the histological preparations of the hearts of rats and mice, respectively. Affected areas were found to be randomly distributed through all layers of the heart. The results show that localized accumulation of plasma albumin and edema formation is induced in the extracellular space of the myocardium by even moderate degrees of respiratory hypoxia.

Animals↗
PubMed1991

Effects of age and gender on fat-induced gallbladder contraction and gastric emptying of a caloric liquid meal: a sonographic study.

In this study, the gastric emptying of a liquid fatty meal and the consecutive gallbladder contraction were simultaneously measured by ultrasound in four different age- and sex-related groups of normal subjects: group A, 15 women less than 50 yr (premenopausal); group B, 15 women greater than 50 yr (postmenopausal); group C, 15 men less than 50 yr; and group D, 15 men greater than 50 yr. Apart from a significantly delayed gastric emptying in the premenopausal women, no significant differences in the postprandial relative gallbladder emptying rates were observed between the four study groups. Ninety-five percent of all study subjects had a gallbladder volume reduction of more than 50% after a liquid fatty meal. It is therefore concluded, that 1) endogenous or contraceptive female sex hormones may have a delaying effect on gastric emptying of caloric liquids in the premenopausal state, 2) aging or gender do not significantly influence the fat-induced gallbladder contraction in man, and 3) a 50% residual volume of the gallbladder after a fatty meal should be considered as the upper limit of normal gallbladder contractility (95 percentile of a normal collective).

Adult↗
PubMed1991

Effects of diltiazem and allopurinol in postischemic microcirculatory changes in the rat kidney.

The influence of diltiazem and/or allopurinol on kidney microcirculation was studied in anaesthetized rats, which were subjected to 60 min unilateral renal ischemia followed by 60 min reflow. In histological sections capillary plasma flow patterns were determined based on the distribution of two different fluorochrome-labelled globulins administered i.v.. In the outer medulla (OM) of untreated postischemic kidneys labelling of the capillary network was greatly diminished. Tissue areas occupied by red blood cells increased 4-6 fold. During reperfusion massive penetration of red cells in the urine was demonstrated by the occurrence of hemoglobin in the urine. Maintenance of the rats on allopurinol-saturated drinking water for six days prior to the experiment (daily intake approximately 50 mg allopurinol/kg body wt) combined with the i.v. administration of diltiazem during the pre- and postischemic period (16 mg/kg body wt) resulted in an almost complete normalization of capillary plasma flow patterns in the OM. In this region tissue areas occupied by red blood cells were much lesser in extent than in the untreated controls. Furthermore, urine hemoglobin content after the combined drug regimen was largely decreased when compared to the untreated ischemic group. Effects of the treatment with either of the drugs alone were qualitatively similar, but significantly less pronounced. In conclusion, a synergistic effect of diltiazem and allopurinol in improving postischemic renal microcirculation is clearly evident, whereas no improvement in kidney function was demonstrable. This supports the hypothesis that disturbed microcirculation is not a prerequisite for the generation of the renal functional deterioration in the clamp-induced ischemia model in the rat.

Allopurinol↗
PubMed1990

Infrared spectroscopy of phytochrome and model pigments.

Fourier-transform infrared difference spectra between the red-absorbing and far-red-absorbing forms of oat phytochrome have been measured in H2O and 2H2O. The difference spectra are compared with infrared spectra of model compounds, i.e. the (5Z,10Z,15Z)- and (5Z,10Z,15E)-isomers of 2,3,7,8,12,13,17,18-octaethyl-bilindion (Et8-bilindion), 2,3-dihydro-2,3,7,8,12,13,17,18-octaethyl-bilindion (H2Et8-bilindion), and protonated H2Et8-bilindion in various solvents. The spectra of the model compounds show that only for the protonated forms can clear differences between the two isomers be detected. Since considerable differences are present between the spectra of Et8-bilindion and H2Et8-bilindion, it is concluded that only the latter compound can serve as a model system of phytochrome. The 2H2O effect on the difference spectrum of phytochrome supports the view that the chromophore in red-absorbing phytochrome is protonated and suggests, in addition, that it is also protonated in far-red-absorbing phytochrome. The spectra show that protonated carboxyl groups are influenced. The small amplitudes in the difference spectra exclude major changes of protein secondary structure.

Fourier Analysis↗
PubMed1990

[The medical careers of the Nikolsburg Seligmann brothers in Vienna of the 19th century: Romeo (1808-1892), Franz (1809-1889) and Leopold (1815-1897)].

The achievements of two medical officers in the Austrian imperial military forces in the second half of the 19th century are enumerated and honoured. The distinguished services rendered by the brothers Franz and Leopold Seligmann in connection with the "Novara" expedition (1857-1859) and the prevention of a cholera epidemic (1873) are described in this paper to prevent their attainments from falling into oblivion. The eldest brother, Romeo Seligmann, founded the Chair of the History of Medicine at Vienna University in 1848 and was the first professor of this discipline.

Austria↗
PubMed1990

Non-uniform influence of transforming growth factor-beta on the biosynthesis of different forms of small chondroitin sulphate/dermatan sulphate proteoglycan.

The influence of transforming growth factor-beta (TGF-beta) on the expression of different forms of small proteoglycans was investigated in human skin fibroblasts and in a human osteosarcoma cell line. TGF-beta was not found to act as a general stimulator of small proteoglycan biosynthesis. In both cell types, an increased expression of the core protein of proteoglycan I was found. However, there was a profound decrease in the expression of a 106 kDa core protein, and either no alteration or a small decrease in the biosynthesis of the collagen-binding small proteoglycan II core protein. These results show that the production of individual members of the small proteoglycan family is differentially regulated.

Biglycan↗
PubMed1990

Influence of collagen lattice on the metabolism of small proteoglycan II by cultured fibroblasts.

Small dermatan sulphate proteoglycan II from cultured human skin fibroblasts interacts with type I collagen in vitro and in vivo. When fibroblasts are maintained in a type I collagen lattice the proteoglycan remains exclusively within the lattice, and its association with fibrils can be demonstrated immunocytochemically. On the basis of [35S]sulphate incorporation, small proteoglycan II comprises about 80% of total proteoglycans secreted by cells in monolayer culture. In a collagen lattice, fibroblasts down-regulate its synthesis to the level of large chondroitin sulphate/dermatan sulphate and of heparan sulphate proteoglycans, the synthesis of which remains unaffected. Compared with the product from monolayer cultures, small proteoglycan II from collagen gels contained a longer polysaccharide chain which is characterized by a larger proportion of disulphated and a smaller proportion of monosulphated glucuronic acid-containing disaccharides. The half-life varied between 60 and 110 h. It is suggested that the compositional differences between the proteoglycan from monolayer cultures and from cells in a collagen lattice are related to the slower intracellular trafficking of the proteoglycan under the latter culture conditions.

Adult↗
PubMed1990

Ultrasensitive enzymatic radioimmunoassay using a fusion protein of protein A and neomycin phosphotransferase II in two-chamber-well microtiter plates.

A new sensitive method for antigen detection employing a phosphorylation reaction is described using human serum albumin as a model. The antigen is initially bound to the surface of polystyrene microtiter plates and reacted with an antibody (rabbit). A microbiologically produced bifunctional fusion protein of protein A and neomycin phosphotransferase II (NPT II) serves as a second immunological reagent by virtue of its protein A component. The detection is based on the phosphorylation of an aminoglycoside antibiotic by the NPT II moiety of the fusion protein using [gamma-32P]ATP as a cosubstrate. This reaction is performed in solution and the evaluation is accomplished by dotting aliquots of the reaction mixture onto phosphocellulose paper, washing with water, and autoradiography. Microtiter plates with a specially designed 10 microliter-volume reaction chamber are particularly advantageous for this procedure. The sensitivity of detection is currently 10 fg (1 pg/ml) of antigen.

Animals↗
PubMed1990

[A new inhalation system for bronchodilatation. Study of the acceptance of the Ingelheim M inhaler in chronic obstructive respiratory tract diseases].

The aim of this study was to investigate the acceptance and convenience of a new inhalation system for the treatment of chronic obstructive pulmonary disease. The Ingelheim M inhalator, an inhalation system with a supply magazine for six powder-filled capsules represents a further development of the Ingelheim inhalator in which only a single capsule can be utilized. The study was designed as an open, randomized, crossover trial involving 60 ambulatory adult patients. Each treatment period lasted two weeks. The medication tested was Berodual Inhaletten. The success of treatment was checked on the basis of peak flow metering each morning prior to and after initial inhalation. The results of the study show a highly significant preference on the part of the patients for the new inhalation system. The advantage most emphasized by the patients was the fact that they were able to carry with them their entire daily dose. Differences in the symptomatology of chronic obstructive pulmonary disease were not observed with these inhalation systems.

Adolescent↗
PubMed1990

Extracellular accumulation of small dermatan sulphate proteoglycan II by interference with the secretion-recapture pathway.

Human skin fibroblasts were metabolically labelled in the presence of affinity-purified antibodies against the core protein of small dermatan sulphate proteoglycan II. The treatment resulted in a dose- and time-dependent accumulation of this proteoglycan in the culture medium, with a 2-3-fold increase found within an experimental period of 4 h. The presence of antibodies was without influence on the rate of biosynthesis of the proteoglycan. However, proteoglycan-antibody complexes were inefficiently endocytosed. Addition of unlabelled proteoglycan, which served as a competitor for uptake, similarly led to an accumulation of newly formed [35S]sulphate-labelled proteoglycans. Proteoglycan accumulation also occurred as a consequence of its binding to collagen fibrils which were physically separated from the cell layer. Together, these results establish the quantitative importance of the secretion-recapture pathway of small dermatan sulphate proteoglycan II in cultured fibroblasts.

Cells, Cultured↗
PubMed1990

The chloroplast CF0I subunit can replace the b-subunit of the F0F1-ATPase in a mutant strain of Escherichia coli K12.

The amino acid sequence of the CF0I subunit from the chloroplast F0F1-ATPase has only a low similarity to the amino acid sequence of the b-subunit of the E. coli F0F1-ATPase. However, secondary and tertiary structure predictions plus the distribution of hydrophobic and hydrophilic amino acids have indicated that these two subunits serve a similar function. This proposition was investigated directly. A cDNA clone for the chloroplast atpF gene, encoding the CF0I subunit, was altered by site-directed mutagensis such that the translation start site corresponded to the N-terminus of the mature protein. An E. coli mutant strain carrying a chain-terminating mutation in the uncF gene, encoding the b-subunit, was transformed with the plasmid carrying the altered atpF gene. The resultant transformant was able to grow on succinate and gave a growth yield similar to that of a wild-type control. Assays on membrane preparations from the transformant also clearly indicated that the mature CF0I subunit from spinach chloroplasts was able to replace the E. coli b-subunit in the E. coli F0F1-ATPase.

Amino Acid Sequence↗
PubMed1990

[Use of fermenter-dialysis culture for the cultivation of medically relevant microbes. III. Candida albicans].

For mass cultivation of Candida albicans (serotype A), a fermenter dialysis culture technique is described and compared with shaking culture and fermenter batch culture techniques. Important growth parameters such as yeast dry weight and viable cell counts demonstrate the advantage of the fermenter dialysis culture. Mannan, the major antigen from Candida albicans prepared by phenol-water extraction followed by gel chromatography was tested with the monoclonal IgM antibody H5.

Candida albicans↗
PubMed1990

[Roentgenologic heart volume determination for the diagnosis of fatal heart failure].

In order to investigate the connection between the cardiac volume and the cardiac shadow plane, 385 anterior-posterior radiographs of the thorax have been selected comparing their cardiac shadow plane with the corresponding cardiac volumes determined by the autopsy of the cadavers. The comparison showed a connection of both magnitudes by means of the formula Hvol = 0.49 x Fa x square root of Fa (Hvol = cardiac volume in cm3, Fa = cardiac shadow plane of the anterior-posterior radiograph in cm2, corrections were made from the radiation divergence). A verification of the formula showed a very high correlation (r = 0.984) in 25 cadavers to be dissected. The comparing volume of the cardiac shadow plane has been investigated by means of the water displacement method, in which the cardiac vessels were ligated and the heart taken out of the cadaver. The cardiac volume, evaluated from the cardiac shadow plane showed a significant correlation at the cardiac death by internal natural cause. The comparison of the mathematical evaluated cardiac blood volumes of the symptoms causing death showed that the cardiac blood volumes in the group of poisonings and the group of drowning, suffocations and hanging with 231 ml and 211 ml in the men collective were at the same level as the cardiac death (246 ml). About the same applied to the women collective.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Output↗
PubMed1990

High-sensitivity protein detection by a new "contact-copy" method using a protein A-neomycin phosphotransferase II fusion protein.

A new system for high-sensitivity protein detection by an immunoenzymatic "contact-copy" procedure is described. It is based on two components: (i) a microbiologically produced bifunctional fusion protein of protein A and neomycin phosphotransferase II (protein A-NPT II) in which the protein A moiety acts as a second immunological reagent while NPT II catalyzes the detection reaction and (ii) a novel kanamycin-loaded substrate matrix (kanamycin-cyanuric chloride-activated and sulfanilic acid-derivatized paper) brought into direct contact with a protein-carrying matrix after blot or dot application and initial immunoreaction--the NPT II enzyme reaction with [gamma-32P]ATP as cosubstrate leads to phosphorylation of the substrate kanamycin on the substrate matrix, which is used for further analysis. The contact-copy method has at least the same detection sensitivity as procedures employing 125I-protein A, but allows extremely short exposure times and avoids probe prelabeling. Twenty-five picograms of specific protein blotted from sodium dodecyl sulfate-polyacrylamide gels onto nitrocellulose is detected after 15 min of autoradiography. The limit of detection in dot tests was found to be 10 pg per dot (3 mm2). The method is suitable for quantitative determination of antigens in the range down to 100 pg. Several contact copies of the same original protein-carrying matrix can be produced and used for detection or quantitative analysis without destroying the original matrix.

Collodion↗
PubMed1990

Extracellular haemolysin of Proteus penneri coded by chromosomal hly genes is similar to the alpha-haemolysin of Escherichia coli.

Extracellular haemolysin of four Proteus penneri strains was characterized as a polypeptide of approximately 110 kD. The chromosomal DNAs of these strains cleaved with Hind III showed three fragments hybridizing with a DNA probe containing cloned haemolysin (hly) genes of Escherichia coli. The results presented here suggested that the haemolysin of P. penneri strains is chromosomally determined and similar to the alpha-haemolysin of E. coli.

Blotting, Southern↗
PubMed1990

K-antigen identification, hemolysin production, and hemagglutination types of Escherichia coli O6 strains isolated from patients with urinary tract infections.

Serotyping of 1918 Escherichia coli strains isolated in significant cell numbers from the urine of patients with urinary tract infections (UTI) revealed the presence of 117 O6 strains. The K antigens were identified by means of K-specific phages and serological methods. The phages used included a K1 phage pool (phi 1, A-E) and the separate phages phi 2, phi 5, phi 7, phi 12 and phi 13. The presence of H antigens, type 1 fimbriae formation, hemolysin production and mannose-resistant hemagglutination (MRHA) ability with human A, sheep, calf and pig erythrocytes were also analyzed. Six different MRHA types were defined and discussed in relation to the O6:K:H serotype. Remarkably, E. coli O6 strains were found to possess a whole arsenal of virulence factors (K antigens, MRHA, hemolysin). The most common serotypes - O6:K2:H1/H- (26), O6:K5:H1/H- (35) and O6:K13:H1/H- (20) - differed from each other in some cases in both MRHA type and hemolysin production.

Antigens, Bacterial↗