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Biomedical subjects

R Otto

Publications and source records attributed to R Otto.

At least 91 records · Page 5Linked to original sources
PubMed1982

[Ultrasound-controlled fine needle puncture of gastrointestinal tumors with continuous view].

On account of its principle, ultrasound tomography cannot be recommended as a screening method for intestinal tumors; nevertheless, it may sometimes demonstrate larger tumors not producing typical signs. These neoplasms show a characteristic pattern ("cockade phenomenon"). In the region of the antrum they appear occasionally as a rigid thickening of the gastric wall. The nature of such an expansive lesion may be evaluated quickly and safely by a fine-needle puncture performed under sonographic control. No complications have been observed so far.

Biopsy, Needle↗
PubMed1982

Plasmid DNA in Streptococcus cremoris Wg2: Influence of pH on Selection in Chemostats of a Variant Lacking a Protease Plasmid.

Cleared lysates of a proteolytic (Prt) strain and a naturally occurring non-proteolytic (Prt) variant of Streptococcus cremoris Wg2 contain equal amounts of covalently closed circular plasmid DNA. An analysis of this plasmid DNA by agarose gel electrophoresis revealed the presence of at least five different plasmid species in the Prt strain and only three plasmid species in the Prt variant. Curing studies with acriflavine indicated that a 16-megadalton plasmid determined proteolytic activity in the Prt strain. In energy-limited chemostats inoculated with both strains it was observed that the Prt strain was replaced by the Prt variant. This effect was most apparent when the pH of the culture was fixed at a value above 6.3. No selection for the Prt variant was observed at pH 5.9. Since the two types of organisms contain equal amounts of plasmid DNA, it was concluded that the energy gain of the Prt variants at pH values above 6.0 probably has to be found in protein synthesis rather than in plasmid DNA synthesis.

Journal Article↗
PubMed1982

Lactate efflux-induced electrical potential in membrane vesicles of Streptococcus cremoris.

We developed a procedure for isolating membrane vesicles from the homolactic fermentative bacterium Streptococcus cremoris. The membrane vesicles were shown to have a right-side-out orientation by freeze-etch electron microscopy and to be free of cytoplasmic constituents. The membrane vesicles retained their functional properties and accumulated the amino acids L-leucine, L-histidine, and L-alanine in response to a valinomycin-induced potassium diffusion gradient. Studies with these membrane vesicles strongly supported the possibility that there was a proton motive force-generating mechanism by end product efflux (Michels et al., FEMS Lett. 5:357-364, 1979). Lactate efflux from membrane vesicles which were loaded with L-lactate and diluted in a lactate-free medium led to the generation of an electrical potential across the membrane. The results indicate that lactate efflux is an electrogenic process by which L-lactate is translocated with more than one proton.

Amino Acids↗
PubMed1981

[Ultrasonic findings in renal diseases with hypertension (author's transl)].

Ultrasound investigations of the kidney were performed in a prospective study in 51 patients with hypertension. It was shown by means of characteristic changes that renovascular and renal parenchymatous diseases can be differentiated. The case of renal atrophy could be demonstrated in 14 out of 20 cases with renovascular changes and in 15 out of 18 cases wtih primary renal parenchymatous disease. There were false positive results in two out of 13 cases of essential hypertension. The importance of intrarenal cysts in the aetiology of hypertension requires further investigation.

False Positive Reactions↗
PubMed1981

[Sonography in the evaluation of reduced function of kidney transplants (author's transl)].

Sonography of 58 kidney transplants has been performed in 56 patients and morphological alterations have been registrated. These results have been compared with clinical examination, blood samples and histological evaluation whenever possible. It is our opinion that certain sonographical phenomena exist, which make the rejection of kidney transplants most probable and even allow for differentiation of different degrees. We found a correlation of right results between sonography and final pathological diagnosis in more than 80% of our patients. Moreover sonography permits the diagnosis of ureteral obstruction or leakage.

Adolescent↗
PubMed1981

[Vocational rehabilitation of heart patients. An analysis of "vocational rehabilitation cases" closed by the federal employment institute (author's transl)].

The number of heart/circulatory disease rehabilitation cases closed annually by the Federal Employment Institute has remained almost the same over the 1972-1978 period. In 1978 the national total of closed heart/circulatory disease cases amounted to 6,325, with 945 of the clients having attended vocational rehabilitation measures/courses. Some 25 percent of the cases are classified as "condition following myocardial infarction"; in male clients, this applies to about one third. Compared to the number of male clients, women are strongly under-represented in vocational rehabilitation of heart/circulatory disease patients. In relation to the structure of the gainfully employed population total, the frequency of vocational rehabilitation measures on heart/circulatory disease diagnoses varies strongly among the individual Laender employment office districts. Considerable differences are apparent when the age structure of heart/circulatory disease rehabilitation cases is compared with that of any other disability group. In case of the first, the number of cases increases with age, while the trend is the very opposite in the latter case. This fact shows that vocational rehabilitation measures for heart/circulatory disease patients need come up to special conditions, and that they have to be determined on different criteria. The rate of integrational solutions considered a positive outcome is considerably lower for heart/coronary disease rehabilitees than for the total of rehabilitees. The participation in vocational rehabilitation programmes of 14.9 percent equally is considerably lower than the corresponding percentage of the total number of rehabilitation cases (26.2 percent).

Female↗
PubMed1980

[Ultrasonically guided percutaneous fine needle aspiration biopsy of pancreatic tumours under permanent visual control (author's transl)].

Using a new method of ultrasonically guided fine needle biopsy under permanent visual control it is now possible to biopsy tumour-suspect changes of the pancreas and other abdominal organs reliably. The risk for the patient can thus be reduced to a minimum. The method leads to considerable improvement in obtaining biopsy material and is easily performed and may be repeated. The correct diagnosis could be established in all of 18 patients with pancreatic disease by cytological investigation. Sonographic interpretation of space occupying pancreatic lesions was successful in only 16 patients.

Adenocarcinoma↗
PubMed1980

[Experience with sonographically controlled fine-needle punctures with permanent visual control (author's transl)].

With our new biopsy-device it is now possible to perform fine-needle punctures of lesions in the abdomen, thoracic cage, cervical region and extremities under continuous visual control. This intervention can easily be done with low risk for the patient and can be repeated whenever necessary. It has proven its advantages for amniocentesis as well, especially in cases with a low amount of amniotic fluid. Moreover, our new device allows the combination of sonographical and radiological interventions, for example of the kidneys.

Aged↗
PubMed1980

Generation of an electrochemical proton gradient in Streptococcus cremoris by lactate efflux.

Recently an energy-recycling model was proposed that postulates the generation of an electrochemical gradient in fermentative bacteria by carrier-mediated excretion of metabolic end products in symport with protons. In this paper experimental support for this model is given. In batch cultures of Streptococcus cremoris with glucose as the sole energy source the maximal specific growth rate decreased by 30% when the external lactate concentration was decreased from 50 to 90 mM. In the same range of external lactate concentrations the molar growth yield Y for glucose as measured in energy-limited chemostat cultures also showed a 30% drop. From Y max lactose values of S. cremoris grown in the presence and absence of added lactate it was calculated that the net energy gain from the lactate efflux system was at least 12%. Lactate efflux from de-energized cells loaded with lactate could drive the uptake of leucine. This uptake was sensitive to carbonylcyanide p-trifluoromethoxyphenylhydrazone and was only partly inhibited by dicyclohexylcarbodiimide (DCCD). The limited inhibition by DCCD of lactate-induced leucine uptake indicates that ATP hydrolysis was not the driving force for transport of leucine. Uptake studies with the lipophilic cation tetraphenylphosphonium demonstrated that lactate efflux increased the electrical potential across the membrane by 51 mV. The generation of an electrical potential by lactate efflux and the demonstration of a potassium efflux-induced uptake of lactate indicates that lactate is translocated across the membrane by a symport system with more than one proton.

Biological Transport, Active↗