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Biomedical subjects

R Wagner

Publications and source records attributed to R Wagner.

At least 19 recordsLinked to original sources
PubMed1992

Human neutrophil mobilization during open heart surgery.

Phagocyte released reactive oxygen species are often discussed in connection with ischemic and reperfusion injuries to the myocardium. The kinetics of the accumulation and oxidative burst of human blood phagocytes was studied by chemiluminescence during open heart surgery in the myocardium of human patients. Direct evidence is presented for an accumulation of neutrophils along with their markedly increased metabolic activity (oxygen radical formation), especially following the reperfusion of the ischemic myocardium. Leukocyte numbers and activity remained significantly elevated even in the venous blood obtained 24 h after the operation.

Cardiac Surgical Procedures↗
PubMed1992

Opposite effects of enantiomers of clofibric acid derivative on rat skeletal muscle chloride conductance: antagonism studies and theoretical modeling of two different receptor site interactions.

The R-(+) enantiomer of 2-(p-chlorophenoxy) propionic acid (CPP) produces a biphasic effect on chloride channel conductance (GCl) of rat skeletal muscle, increasing GCl at low concentrations and decreasing it at concentrations greater than 10 microM; on the other hand, the S-(-) isomer mostly blocks GCl in a concentration-dependent manner. To explain the peculiar behavior of these compounds, a theoretical model based on the presence of two opposing receptor populations controlling chloride channel conductance has been used to fit the experimental data of the concentration-response curves of both S-(-) and R-(+) CPP. An analysis performed by means of the algebraic summation of two logistic terms suggests a reasonable merit of the proposed model and explains the resultant effect of each optical form as follows: S-(-) acts as a full agonist on an inhibitory sites, whereas R-(+) acts as a full agonist at both the inhibitory and excitatory sites. Antagonism studies appear to be consistent with the proposed model. Dose-response curves in which the block of GCl by the S-(-) isomer was evaluated in the presence of the R-(+) isomer (3-10 microM) clearly showed an antagonistic interaction between the two enantiomers, with an increase in the S-(-) concentration for half-maximal block. The antagonism was overcome by high concentrations of S-(-), and this might be consistent with the hypothesis that the block of GCl is modulated by an inhibitory site at which the two enantiomers compete.

2-Methyl-4-chlorophenoxyacetic Acid↗
PubMed1992

[Results of surgical therapy of bronchial cancers with reference to adjuvant therapeutic measures in an advanced stage].

UNLABELLED: The prognosis of bronchial carcinoma especially in advanced tumor stage is poor despite different methods of treatment. The 5-year survival rate after radical operation is about 25-40% for all stages, and between 17-20% in stage III. Without therapy it is 3.5-9.5%. T3-tumors and N2-lymphnodes represent the limit of surgical therapy. From 1980 to 1988 we operated 456 patients because of bronchial carcinoma, 80% men (mean age 59.2 y) and 20% women (mean age 56.9 y). 83.1% had been smokers, 16.9% had been exposed to contaminants. At admission to the hospital 36% were in stage I, 13% in stage II, 47% in stage III, and 4% in stage IV. HISTOLOGY: squamous cell carcinoma 40.9%, adenocarcinoma 26.1%, large cell carcinoma 21.9%, and small cell carcinoma 11.1%. Looking at all cases we mostly performed a lobectomy, in stage III tumors the most common operation was pneumonectomy. In this group only 57.5% of the patients were resectable. In 77 potentially curative operated patients in stage III with non-small cell carcinoma we performed an adjuvant radio-, chemo- or combined therapy. The cumulative survival rates for all patients in the 1st year were 85% in stage I, 67% in stage II, and 36% in stage III and IV. In the 3rd year 57%, 14% and 10%, and in the 5th year 41%, 7%, and 5%. In stage III the survival rates of the potentially curative operated vs. the exploratively operated patients were in the 1st year 50%/36%, in the 3rd year 16%/10%, and in the 5th year 11%/5%.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma, Non-Small-Cell Lung↗
PubMed1991

Enzyme sensor-FIA-system for on-line monitoring of glucose, lactate and glutamine in animal cell cultures.

Enzyme sensors for glucose, lactate and glutamine were connected via flow-injection analysis (FIA) devices to two different bioprocesses. They were used for on-line process control of perfused bioreactor systems containing mammalian cell lines producing a monoclonal antibody and recombinant interleukin-2. The biosensor system gives direct access to important process data which can be used as control parameters for long term cell cultivation systems.

Animals↗
PubMed1990

Production of recombinant human interleukin-2 with BHK cells in a hollow fibre and a stirred tank reactor with protein-free medium.

For the production of recombinant human interleukin-2 (IL-2) two different culture processes, a 1-2 liter homogeneous stirred bubble-free aerated system and a dense cell hollow fibre bioreactor were compared. Cultivations were carried out with serum- or protein-free medium formulations. In the stirred culture 0.75 mg IL-2 were produced with 1 l of perfused medium at a maximum cell number of 3 X 10(10). The product yield in the hollow fibre module was only 0.23 mg l-1 at a maximum cell number of 6 X 10(10). In contrast to results with hybridoma or EBV-transformed cell lines, in which hollow fibre bioreactors showed comparable efficiency to perfused stirred tank reactors, the tissue-like cell density is disadvantageous as adherent cells tend to stick together leaving insufficient intercellular space for removal of product.

Animals↗
PubMed1979

Phase transition characteristics of diphosphatidyl-glycerol (cardiolipin) and stereoisomeric phosphatidyldiacylglycerol bilayers. Mono- and divalent metal ion effects.

Synthesis and phase transition chaaracteristics of aqueous dispersions of the homologous (12 : 0, 14 : 0, 16 : 0) diphosphatidylglycerols (cardiolipins) and phosphatidyldiacylglycerols are reported. Electron microscopy of the negatively stained aqueous dispersions reveals a characteristic lamellar structure suggesting that these phospholipid molecules are organized as bilayers in the aqueous dispersions. The phase transition temperature (Tm) and the enthalpy of transition (delta H) increase monotonically with chain length in the cardiolipin and phosphatidyldiacylglycerol series; Tm for phosphatidyldiacylglycerol is higher than that for cardiolipin of the same chain-length. The transition temperatures for the enantiomeric sn-3,3- and sn-1,1-phosphatidyldiacylglycerol and for the diastereomeric, meso-sn-1,3-phosphatidyldiacylglycerol are approximately the same. The molar enthalpy for the transition of cardiolipin-NH+4 bilayers is approximately twice the value for the phosphatidylcholines of the same chain length, i.e., the molar enthalpy per acyl chain is approximately the same in the two systems. The transition temperatures for metal ion salts of C16-cardiolipin exhibit a biphasic dependence upon the unhydrated ionic radii, i.e., the highest Tm is observed for Ca2+-cardiolipin and decreases for the salts of ions with smaller and larger ionic radii than that of Ca2+. The lowest Tm is observed for Rb+-cardiolipin. Monovalent metal salts of cardiolipin exhibit two phase transitions. This effect may result from different conformational packing of the four acyl chains due to differences in metal-phosphate binding.

Cardiolipins↗
PubMed1979

A ribonuclease-resistant region of 5S RNA and its relation to the RNA binding sites of proteins L18 and L25.

An RNA fragment, constituting three subfragments of nucleotide sequences 1-11, 69-87 and 89-120, is the most ribonuclease-resistant part of the native 5S RNA of Escherichia coli, at 0 degrees C. A smaller fragment of nucleotide sequence 69-87 and 90-110 is ribonuclease-resistant at 25 degrees. Degradation of the L25-5S RNA complex with ribonuclease A or T2 yielded RNA fragments similar to those of the free 5S RNA at 0 degrees C and 25 degrees C; moreover L25 remained strongly bound to both RNA fragments and also produced some opening of the RNA structure in at least two positions. Protein L18 initially protected most of the 5S RNA against ribonuclease digestion, at 0 degrees C, but was then gradually released prior to the formation of the larger RNA fragment. It cannot be concluded, therefore, as it was earlier (Gray et al., 1973), that this RNA fragment contains the primary binding site of L18.

Base Sequence↗
PubMed1979

The mechanism of epithelial shedding after ischemic damage to the small intestinal mucosa. A light and electron microscopic investigation.

The intestinal mucosa of the rat was examined by light and electron microscopy 15, 30, 60 and 120 min after complete ligation of the vessel arcades of the proximal jejunum. The characteristic sign of ischemic damage to the small intestinal mucosa and the reason for epithelial shedding is the appearance of membrane enclosed cytoplasmic blebs which arise at the cell base of the enterocytes and detach the epithelium from the basement membrane. This process begins at the tip of the villi before the enterocytes display signs of irreversible damage and progress to the base of the villi with continuation of the ischemia.

Animals↗
PubMed1979

Selenium requirement for active xanthine dehydrogenase from Clostridium acidiurici and Clostridium cylindrosporum.

The xanthine dehydrogenase of Clostridium acidiurici and C. cylindrosporum was assayed with methyl viologen as acceptor. In C. acidiurici the basal activity level was about 0.3 mumol/min x mg of protein. Cells grown on uric acid in the presence of 10(-7) M selenite showed a 14-fold increase in xanthine dehydrogenase activity, which decreased with higher selenite concentrations (10(-5) M). The supplementation with 10(-7) M molybdate or tungstate was without effect. High concentrations of tungstate decreased the xanthine dehydrogenase if selenite was also present. In comparison, high concentrations of molybdate affected only a small decrease in activity level at the optimal concentration for selenite and relieved to some degree the inhibitory effect of 10(-5) M selenite. With hypoxanthine and xanthine as substrates for growth again only the addition of selenite was necessary to show a similar increase in xanthine dehydrogenase activity. C. acidiurici could be grown in a mineral medium. Both xanthine dehydrogenase and formate dehydrogenase exhibited the highest level of activity if selenite and tungstate were present in that medium. In C. cyclindrosporum the basal activity level of xanthine dehydrogenase was about 0.95 mumol/min x mg of protein. The addition of 10(-7) M selenite to the growth medium increased the activity level about 3-fold, but the highest level (3.7 U/mg) was reached if 10(-7) M molybdate was also added. The presence of tungstate resulted in a decreased enzyme activity.

Cell-Free System↗
PubMed1979

Carcinoma of the oral cavity: on the prognostic significance of the primary tumour site (by levels and areas).

The prognostic significance of primary tumour site in carcinomas of the oral cavity was investigated in a series of 585 cases. For the subsamples (levels and areas of oral cavity) studied, the numerical distribution of TNM categories, life tables and life table comparisons were computed. This produced the following results: Given an identical extension and analogous metastazising rate, there is no computationally demonstrable difference in prognosis between primary tumours sited at different levels and areas of the oral cavity. The exception are the T1Nx categories, for which a difference exists between precanine and retromolar sites. These results should be re-examined on the basis of a larger series.

Actuarial Analysis↗
PubMed1979

Chemical evidence for a codon-induced allosteric change in tRNALys involving the 7-methylguanosine residue 46.

[32P]TRNALys, from Escherichia coli, was modified with kethoxal, in the presence and absence of the oligonucleotide codon (A)4. The presence of the codon resulted in a faster modification rate of the tRNA at three guanine sites which were identified by a diagonal fingerprint method. A large increase in the modification rate occurred at the 7-methylguanosine residue 46 (m7G-46) in the presence of the codon: weakly enhanced modification was observed at G-15 and G-57. It is concluded that the formation of a codon-anticodon complex induces, primarily, a conformational change involving disruption of the m7G-46 from the m7G-46 . G-22 . C-13 base triple. Subsequently, the guanines of G-15 and G-57, in the D and T loops, respectively, become slightly more reactive, suggesting a weak tendency for these two interacting arms to unfold. The results are interpreted in terms of an equilibrium between two main conformers, and a third minor one; the possible significance of these conformers in protein biosynthesis, is considered.

Base Sequence↗
PubMed1979

[On the influence of thiocyanates on the delayed immune response in intact and epinephrectomised guinea pigs (author's transl)].

Daily application of 32 mg/kg sodium thiocynate from 1--11th respectively 12th--21st experimental day causes in epinephrectomised guinea pigs at the 26th experimental day an inhibition of cell-mediated immune response (sensitization was induced by intraperitoneal injection of horse serum at the 5th and 7th experimental day). The inhibition of cell-mediated immune response could be demonstrated by means of migration inhibition of spleen cells. Epinephrectomy was performed by operation procedures twice a week. Gluco- and mineralocorticoids were applied supplementary. -- Also other proved thiocyanates respectively compounds with thiocyanate groups such as potassium thiocyanate, ammonium thiocyanate and d,1-2-imino-3.4-dimethyl-5-phenyl-thiacolidinhydrothiocyanate showed the same effect. The results are only pointed out in intact animals, but distinct in epinephrectomised guinea pigs. Finally a significant weaker effect, but of the same kind was observed by potassium- and sodium iodate. Every used dose of prednisolone and cyclophosphamide suppress the migration inhibition. The influence of 2-iminothiacolidin-4-carbon acid and desoxycorticosteronacetat on the migration inhibition is different and depends on the antigen dose applied for sensitization. -- Simulated daily injections undertaken in form of stitches and application of aqua destillata are inefficacious.

Adrenal Glands↗
PubMed1979

Ultrasonic evaluation of the gallbladder in sickle cell disease.

The gallbladder is frequently diseased in sickle cell anemia. The distinction between cholecystitis and the abdominal crisis of sickle cell disease is difficult to make. Ultrasonography permits a rapid evaluation of the gallbladder in sickle cell disease.

Adult↗
PubMed1978

[Hormone dependent, functional gynecologic morphology in infancy and adolescence presented on the example of the cervix uteri].

Signs of different activities in the dynamic morphology of the epithelium and mucus of the cervix uteri are demonstrated in the female fetus, newborn, child and adolescent. Besides the morphological description of the ectropium, transitional zone, s.c. "reserve-cells", squamous cell nodes and production and secretion of mucus other investigations were done by allometry, caryometry and histochemistry. The examinations allow insight into the hormonal activities specially of the estrogenes in different periods of female life.

Adolescent↗