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Biomedical subjects

R Otto

Publications and source records attributed to R Otto.

At least 127 records · Page 7Linked to original sources
PubMed1976

S-formylgluthathione: the substrate for formate dehydrogenase in methanol-utilizing yeasts.

Formaldehyde dehydrogenase and formate dehydrogenase were purified 45- and 16-fold, respectively, from Hansenula polymorpha grown on methanol. Formaldehyde dehydrogenase was strictly dependent on NAD and glutathione for activity. The Km values of the enzyme were found to be 0.18 mM for glutathione, 0.21 mM for formaldehyde and 0.15 mM for NAD. The enzyme catalyzed the glutathione-dependent oxidation of formaldehyde to S-formylglutathione. The reaction was shown to be reversible: at pH 8.0 a Km of 1 mM for S-formylglutathione was estimated for the reduction of the thiol ester with NADH. The enzyme did not catalyze the reduction of formate with NADH. The NAD-dependent formate dehydrogenase of H. polymorpha showed a low affinity for formate (Km of 40 mM) but a relatively high affinity for S-formylglutathione (Km of 1.1 mM). The Km values of formate dehydrogenase in cell-free extracts of methanol-grown Candida biodinii and Pichia pinus for S-formylglutathione were also an order of magnitude lower than those for formate. It is concluded that S-formylglutathione rather than free formate is an intermediate in the oxidation of methanol by yeasts.

Aldehyde Oxidoreductases↗
PubMed1976

Growth of Hansenula polymorpha in a methanol-limited chemostat. Physiological responses due to the involvement of methanol oxidase as a key enzyme in methanol metabolism.

Hansenula polymorpha has been grown in a methanol-limited continuous culture at a variety of dilution rates. Cell suspensions of the yeast grown at a dilution rate of 0.16 h-1 showed a maximal capacity to oxidize excess methanol (QmaxO2) which was 1.6 times higher than the rate required to sustain the growth rate (QO2). When the dilution rate was decreased to 0.03 h-1, QmaxO2 of cells increased to a value of more than 20 times that of QO2. The enzymatic basis for this tremendous overcapacity for the oxidation of excess methanol at low growth rates was found to be the methanol oxidase content of the cells. The level of this enzyme increased from 7% to approximately 20% of the soluble protein when the growth rate was decreased from 0.16 to 0.03 h-1. These results were explained on the basis of the poor affinity of methanol oxidase for its substrates. Methanol oxidase purified from Hansenula polymorpha showed an apparent Km for methanol of 1.3 mM in air saturated reaction mixtures and the apparent Km of the enzyme for oxygen was 0.4 mM at a methanol concentration of 100 mM. The involvement of an oxygen dependent methanol oxidase in the dissimilation of methanol in Hansenula polymprpha was also reflected in the growth yield of the organism. The maximal yield of the yeast was found to be low (0.38 g cells/g methanol). This was not due to a very high maintenance energy requirement which was estimated to be 17 mg methanol/g cells X h.

Alcohol Oxidoreductases↗
PubMed1976

[Malignant peritoneal mesothelioma].

A case of diffused malignant mesothelioma of the peritoneum in a 64-year-old man is presented. This mesothelioma, of the papillary type, was complicated, after a year without significant clinical symptoms, by the development of ascites and obstructive upper bowel ileus. Physiological-anatomical and clinical aspects, as well as special radiologic findings and therapeutic regimens, are discussed in the light of the literature. It is recommended that all patients with malignant mesothelioma of the peritoneum be treated by total abdominal irradiation and intreperitoneal instillation of colloid P32.

Ascites↗
PubMed1976

[Directions for mammography from a radiological viewpoint].

A significant decrease in mortality due to breast cancer is feasible only by earlier diagnosis. The decisive screening method is mammography, which permits identification of a malignancy in its earliest stages. Indirect and direct signs of malignancy exist whose detection necessitates biopsy. Radiological examination of the tissue sample permits evaluation of the adequacy of excision and thus renders possible specific histological examination of the region of interest. Pneumocystography is a method for simultaneous diagnosis and therapy of benign cysts.

Adult↗
PubMed1976

[Bronchial carcinoids (author's transl)].

Of 35 patients with bronchial carcinoids seen at the Kantonsspital Zürich during 16 years, 33 underwent an operative resection. The endoscopic resection is not recommended because of the risk of hemorrhage recurrence, and that this operation results in only partial removal of carcinoids which develop extrabronchially. It is concluded that bronchial carcinoids are potentially malignant tumours and that resection should be most radical if they show recurrence, invasive growth or metastases. Controls are necessary for a long period of time because even in presence of metastases the growth is very slow.

Adolescent↗
PubMed1976

[The place of xerography combined with routine conventional mammography (author's transl)].

Xeroradiography is a valuable supplement to conventional mammography, especially in cases with dense glandular structure. In our patient material this new procedure was necessary for clarification of findings on conventional mammography in 16% of cases and improved diagnostic yield. Indirect and direct signs of carcinoma were more easely recognized with xeroradiography, since more detail is visualized because of greater latitude and edge contrast enhancement. Moreover the area visualized is considerably greater. The soft tissue structures can be seen to the level of the thoracic wall. Viewing the films is less tiring than reviewing conventional mammography films. A relatively greater exposure latitude and short exposure times are further advantages of this method.

Adenoma↗
PubMed1975

Oxidation of methanol, formaldehyde and formate by catalase purified from methanol-grown Hansenula polymorpha.

Catalase has been partially purified from cell-free extracts of methanol-grown Hansenula polymorpha and its peroxidative properties were studied. It was shown that the enzyme is capable of oxidizing methanol, formaldehyde and formate in the presence of hydrogen peroxide. The physiological significance of these reactions in the transduction of energy from the oxidation of methanol in yeasts is discussed.

Ascomycota↗
PubMed1975

[Pulmonary echinococcus cysticus].

A 23-year-old Spanish male presenting with hemoptysis, fever and radiologic signs of lung tumor was found to have hydatid disease of the lung with rupture into the bronchial system. Diagnosis was possible only by demonstration of scoleces in the sputum. The cyst was totally enucleated by surgery. The epidemiology, diagnosis and treatment of this quite rare disease are briefly reviewed with special reference to immunology, radiology and cytology.

Adult↗
PubMed1975

Correction of transposition of the great vessels with previous Baffes procedure.

Twenty-four patients with transposition of the great vessels who underwent a Baffes procedure in infancy were totally corrected by a modified Mustard procedure. There were three postoperative deaths and one major complication. All survivors have been followed from 2 to 8 yr and have done well except for one patient who required a tricuspid valve replacement because of tricuspid insufficiency. It is our conclusion that this group of patients can be corrected with a relatively low mortality and a favorable outcome.

Adolescent↗
PubMed1975

[A comparison of xero-tomography of the lung hilum with conventional tomography (author's transl)].

Because of its particular photoelectric properties, xero-tomography is particularly suited for the investigation of abnormalities in the hilar regions. It is superior to conventional tomography because of the improved edge contrast, which emphasises details of relatively non-opaque structures, and because of its high exposure latitude. This justifies its use despite the higher radiation dose that is necessary. The demonstration of relatively dense and of more transradient tissues on the same picture by xero-tomography, and the ability to read it by ordinary light, makes it less tiring to interpret than the translucencies of conventional radiographs.

Adult↗
PubMed1975

[Normal antistreptolysin titres and demonstration of rheumatoid factors in rhesus monkeys (Macaca mulatta) (author's transl)].

Rhesus monkeys are often used as experimental animals. Many clinical and biochemical parameters are known but there are only few papers dealing with the normal values of antistreptolysin O (ASL). Informations about antistreptococcal antibodies are necessary in order to follow the course of immunization and infection experiments. When non-absorbed sera were used, the mean value of antistreptolysin O in clinically healthy rhesus monkeys (Macacus rhesus) amounted to 178 +/- 52 ASU. After absorption with dextran sulphate, the mean value was 90 +/- 20 ASU. Absorption with dextransulphate is a necessary prerequisite to exact determinations of antistreptolysin titres because it removes unspecific inhibitors of streptolysin O. In the sera of rhesus monkey more inhibitors were present than in human sera. On an average, in monkeys 55% of the material reacting with streptolysin O was an inhibitor, compared with about 40% in human sera. As a result of common infections with streptolysin O-producing streptococcal groups C and G antistreptolysin titres can frequently be seen to increase above the average normal value. Using non-absorbed and dextran sulphate absorbed sera, respectively 350 and 200 ASU must be regarded as the normal upper limits for serum antistreptolysin-titres.

Animals↗