Search PubMed⌕ Search

Biomedical subjects

R Schmidt

Publications and source records attributed to R Schmidt.

At least 739 records · Page 41Linked to original sources
PubMed1979

[Therapy of a refractory idiopathic thrombocytopenic purpura by vinblastine-loaded thrombocytes (author's transl)].

A 15-year-old patient with ITP which was refractory to corticosteroids, splenectomy, and immunosuppressive therapy with vincristine was twice treated with platelets loaded with vinblastine. Five days after the application of the platelets vinblastine complex the platelets began to rise up to 600 X 10(9)/l. The remission has lasted until now for more than 15 weeks. The therapy showed no major side effects except for a transient granulocytopenia.

Adolescent↗
PubMed1979

Purification and characterization of the hypoxanthine-guanine phosphoribosyltransferase from Saccharomyces cerevisiae.

1. Hypoxanthine-guanine phosphoribosyltransferase (EC 2.4.2.8) from Saccharomyces cerevisiae was purified 9400-fold by affinity chromatography giving rise to an electrophoretically homogeneous preparation. 2. The molecular weight of the enzyme was determined by gel filtration with Sephadex G-100 and by sodium dodecylsulfate gel electrophoresis. Both methods reveal a molecular weight of 51,000. 3. The enzyme requires Mg2+ and has its pH optimum at 8.5. 4. Isoelectric focussing as well as gel electrophoresis of the purified extract reveals a single band which exhibits enzyme activity. The isoelectric point of the enzyme is 5.1. 5. The enzyme displays Michaelis-Menten kinetics with apparent Michaelis constants for hypoxanthine, guanine and phosphoribosylpyrophosphate of 23 microns, 18 microns, and 50 microns respectively.

Hypoxanthine Phosphoribosyltransferase↗
PubMed1979

Systemic promoting action and leukemogenesis in SWR mice by phorbol and structurally related polyfunctional diterpenes.

Phorbol and six structurally related compounds representing the polyfunctional diterpenes of the tigliane, ingenane, and lathyrane types were tested for systemic promoting and leukemogenic activity in SWR mice. For systemic initiation soon after birth, 15 microgram dimethylnitrosamine (DMN) was injected s.c. The diterpenes were administered i.p. either with or without prior systemic initiation with DMN. Systemic promotion was expressed for liver by induction of adenomas with all the diterpenes tested, some of them being more potent than phorbol. The relatively high dose of DMN used as initiator prevented an evaluation of promoting action in relation to lung carcinogenesis. The leukemogenic effect of phorbol in SWR mice was confirmed at three different dose levels. The other diterpenes tested had no significant leukemogenic activity. The leukemogenic action of phorbol was totally inhibited by prior DMN injection. The lack of correlation between promoting action in skin, systemic promoting action in liver and leukemogenic action, among the diterpenes tested, is discussed.

Animals↗
PubMed1979

Tumor initiators and promoters in the induction of Epstein-Barr virus.

The effect of various tumor initiators and promoters on induction of persisting Epstein-Barr virus (EBV) in different lines of lymphoblastoid cells was analyzed. Neither five polycyclic aromatic hydrocarbons, amongst them potent tumor initiators (e.g., 7,12-dimethylbenz[a]anthracene), nor the potent (ultimate) liver carcinogen N-acetoxy-N-2-acetylamino-fluorene induced EBV. A series of compounds, representing three classes of tumor-promoting diterpene esters (e.g., 12-O-tetradecanoylphorbol-13-acetate), efficiently induced EBV in persistently infected cells. The concentration required for maximal induction ranged between 0.5 and 100 nM. Some nonpromoting diterpenes (phorbol, 4alpha-phorbol-12,13-didecanoate, and ingenol) did not induce EBV. However, the nonpromoters, resiniferatoxin and 12-deoxyphorbol-13-decatrienoate, were effective, whereas anthralin, a tumor promoter, did not induce EBV. In three lines of EBV genome-carrying cells (Raji, NC-37, and RPMI 64-10) only abortive induction was noted, leading exclusively to synthesis of early antigen. In cells of lines with low spontaneous virus release (P3HR-1, B95-8, and QIMR-Wil), upon treatment with tetradecanoylphorbol acetate, approximately 20-40 times more viral DNA was recovered as compared to untreated controls. Viral DNA from tetradeca-noylphorbol acetate-induced cultures revealed the same restriction endonuclease cleavage pattern as viral DNA obtained from noninduced cells. Within 10 days after induction, release of infectious virus increased approximately by one order of magnitude. Prostaglandins, reported to be released after treatment with tumor promoters, were ineffective in virus induction under the conditions tested.

Carcinogens↗
PubMed1979

The usefulness of theophylline in nonasthmatic airway obstruction.

This study evaluated the effectivness of oral bronchodilator therapy using theophylline in patients with nonreversible chronic obstructive pulmonary disease. Twelve chronic obstructive pulmonary disease patients were entered into a doubleblind crossover study using either active drug theophylline in 200 mg capsules (Elixophyllin) or placebo for 3 months, followed by 3 months of the alternate capsule. At baseline and monthly visits, data were recorded, including history, physical examination, and pulmonary function testing. Clinically, 7 of 11 patients responded favorably to theophylline, 3 were unchanged, and 1 improved on placebo. Comparison of each sign and symptom individually revealed no statistically significant differences. Pulmonary function (FEV1 and FVC) showed slight deterioration with placebo, but not with active drug therapy. These findings suggest that nonasthmatic patients may improve clinically during theophylline therapy whereas their pulmonary function may deteriorate during placebo therapy.

Adult↗
PubMed1979

[Possibilities of using hemoperfusion in the treatment of chronic kidney insufficiency].

A survey of the administration possibilities of the activated charcoal haemoperfusion in the treatment of the chronic renal insufficiency is given. Various coating methods for activated charcoal as well as important adsorption abilities of the activated charcoal for uraemia-specific metabolites are described in detail. Then comes a classification of the haemoperfusion in the treatment of ureamia. The result is that at present the use of haemoperfusion with activated charcoal in the therapy of uraemia may be regarded only as a supplementary therapy of the haemodialysis and the haemofiltration, respectively.

Adsorption↗
PubMed1979

[Serum complement and protein metabolism in chronic dialysis patients].

1. When a so-called free diet is granted there is the danger of a protein deficit, which can be proved in a significant decrease of the serum transferrin and of the complement factor E3c, in patients in the chronic haemodialysis programme. 2. Within the group undergoing dialysis a correlation analysis did not result in a statistically ascertained connection between the complement factor C3c and the total haemolytic activity and the transferrin, respectively. 3. On the basis of a diet analysis a connection between the protein supply and the serum transferrin level could be established, which was not to be proved for the complement factor C3c and the total haemolytic activity, respectively. 4. Low transferrin values in the serum seem to be followed by a deterioration of the anaemia situation of the patient undergoing haemodialysis. 5. Compared with the total haemolytic activity and the complement factor C3c the determination of the serum transferrin allows an essentially exacter information about the protein metabolism of the patient undergoing a chronic haemodialysis.

Blood Proteins↗
PubMed1979

Serum complement and protein metabolism in chronic dialysis patients.

1. Patients receiving regular hemodialysis treatment who are permitted to select their own diets are in danger of a protein deficiency manifested by a significant reduction in serum transferrin and in complement C3c. 2. Correlation analysis within the dialysis group revealed no secure connexion between the complement C3c and total hemolytic activity respectively, and transferrin levels. 3. Analysis of diets showed that protein intake and the serum transferrin level correlate. No such correlation was found for the complement C3c or total hemolytic activity. 4. Low transferrin levels in the serum appear to result in more severe anemia among dialysis patients. 5. Knowledge of the serum transferrin level permits much more exact assessment of the protein metabolism in regular hemodialysis patients than knowledge of the total hemolytic activity or the level of the complement C3c.

Blood Proteins↗
PubMed1979

[Influence of strumectomy on preoperative tracheal compression (author's transl)].

Young persons and the groups of age past fifty years form the greatest portion of preoperative tracheal compressions caused by struma. In most cases there is no relationship between subjective complaints and objective findings. 80% of all retrosternal strumata showed a narrowing of the trachea. The age of the patients could be found to be the most important factor for restitutio ad integrum of the compression of the trachea.

Adolescent↗
PubMed1979

Determination of continuous neutron energy spectra for dosimetric purposes.

The energy distribution of 3H(d, n)4He neutrons from a neutron therapy facility has been studied in different depths in a lucite phantom with two methods. Thin foils of 8 different target materials with well-known excitation functions and reaction thresholds between 1.8 and 12.6 MeV for the reactions to be observed have been activated. Secondly, recoil proton spectra have been measured with a small stilbene crystal. In both cases neutron energy spectra have been determined with unfolding methods. The two techniques are compared with respect to the application in neutron dosimetry and for monitoring purposes in neutron therapy.

Mathematics↗
PubMed1978

[Specific characteristics of hairy cell leukemia].

Report on a now 58-year-old female patient who presented in 1969 with the following objective findings: anemia, thrombocytopenia, lymphocytosis and hepatosplenomegaly. The first first diagnosis was lymphosarcoma, but up to 1976 nearly ten other diagnoses were established, e.g. reticulum sarcoma, leukemic lymphosarcoma, CML, ALL, CLL and Waldenström's disease. The patient did not respond to combined chemotherapy, but splenectomy brought about significant improvement in anemia and thrombocytopenia. She is now doing well without cytotoxic treatment. Hairy cell leukemia was diagnosed on the basis of electron microscopic findings in peripheral lymphocytes and histologic findings in bone marrow and spleen. The tartrate-resistant acid phosphatase was positive. Immunologic tests in the hairy cells showed surface immunoglobulins of monoclonal origina and the T-cells were shown to be decreased. The tests for phagocytosis and nonspecific esterase were negative. The hairy cells in this patient exhibited no colony stimulating activity in culture studies with bone marrow from 4 normal donors, as compared with the stimulating activity of normal monocytes in the same assay. In the light of this case report the question is discussed whether the hairy cells are mainly cells with lymphocytic (B-lymphocytes) or monocytic characteristics. On this question the findings in our patient support the hypothesis of a B-cell nature for the hairy cells.

Acid Phosphatase↗
PubMed1978

The effect of position of patient on the passage of metrizamide (Amipaque), meglumine locarmate (Dimer X) and ioserinate (Myelografin) into the blood after lumbar myelography.

Lumbar myelography was carried out with the contrast media Amipaque, Dimer X and Myelografin in 10 patients each. Five of the patients treated with each contrast medium were kept in a sitting position after the examination, the others lay flat. Blood levels and excretion were measured up to 24 h. The results are interpreted as follows: 1. After lumbar injection of the contrast media there is a short phase of distribution in the subarachnoid space (lag time) and they then are transferred into the blood with a half-life of 3.9 +/- 2.4 h. The transport from the CSF is almost completed approximately after 24 h. The velocity of transport varies greatly between the individual patients. Watersoluble contrast media presumably flow passively with the CSF through the arachnoid villi into the venous blood. 2. The horizontal position of the patient reduces the lag time until the beginning of the actual transfer of the contrast medium. 3. The transfer of Dimer X begins somewhat later compared with Amipaque and Myelografin.

Contrast Media↗