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Biomedical subjects

R Richter

Publications and source records attributed to R Richter.

At least 199 records · Page 11Linked to original sources
PubMed1981

[The influence of observer-dependent properties upon the evaluation of fetal heart rate recordings (author's transl)].

The significance of the observer's experience in the evaluation of fetal heart rate (FHR) recordings has not yet been dealt with in the literature. Therefore the qualitative and quantitative determination of these subjective factors has been studied as follows at the University of Basle Department of Obstetrics and Gynecology: Twenty FHR recordings were simultaneously analyzed by twenty-five residents with different levels of obstetrical experience. The results were compared with those of physicians with expertise in FHR monitoring. It became obvious that ominous antepartum FHR tracings were significantly less often correctly identified than harmful intrapartum recordings (p less than 0.001). Harmless changes in intrapartum FHR tracings were more frequently misjudged as being ominous than normal antepartum FHR tracings (p less than 0.05). The following conclusions were made: - There is a real danger of a fatal error in the interpretation of ominous antepartum FHR recordings. - The presented data seem to reveal the source of the increased caesarean section rate described by others as to be associated with FHR monitoring. - The errors in the interpretation of FHR tracings decrease significantly (p less than 0.05) with increasing experience. Thus physicians' education is eminently important for the correct use of electronic fetal monitoring.

Cesarean Section↗
PubMed1981

[Tuberculosis of the calcaneus. Treatment and differential diagnosis (author's transl)].

Eight lesions in the calcaneus have been treated surgically between 1955 and 1979; of these, six were due to tuberculosis, one to chronic osteomyelitis and the other was a cyst. The diagnosis was confirmed bacteriologically and histologically. In all cases (average age 49.1 years) the human bacillus was proved to be the cause of an haematogenous infection. The lesion was confined to the posterior part of the bone and there was no extension into the calcaneo-navicular joint. Two patients presented with fistulae. The interval from the onset of symptoms to confirmation of the diagnosis averaged 9.1 months. Three patients had previously been treated for tuberculosis (lung, pleura, kidney) and another patient, who had a simultaneous tuberculous infection of a sternoclavicular joint had suffered from tuberculosis cervical lymphadenitis at the age of nine years.U

Bacteriological Techniques↗
PubMed1981

Alcohol-induced biphasic background and stimulus-elicited EEG changes in relation to blood alcohol levels.

The effects of 0.8 g alcohol kg-1 on CNS processes as reflected in EEG changes were studied in controlled experiments in 14 subjects in relation to BAC levels. A Two Period Change-Over Design with repeated trials over time allowed us to ascertain the time course and to isolate alcohol-induced changes from diurnal variations and effects of sequence and period. Based on spectral analysis of analog EEG recordings, the study has shown differential patterns of bi-phasic or tri-phasic alcohol-induced EEG changes over time in a number of parameters in background and in stimulus-elicited EEG responses varying with the BAC level and the metabolic phase of alcohol biotransformation. An increase in alpha activity during the absorption phase, a shift in the median of the total spectral power to the right (upwards), a decrease in slow activity in the delta and theta bands, and a decrease in variability of the background EEG on one hand and a reduction in stimulus-elicited EEg responses in total spectral alpha, theta and delta bands on the other are all interpreted as a stimulating excitatory effect during the absorption phase, parallel to the increase in BAC. The reverse pattern in the first part of the elimination phase infers a decrease in cerebral activation reflecting the sedative, depressant action of alcohol in this phase. The effects observed in the last trial, to a certain extent interpreted as stimulating, were simultaneous with the beginning of the post-alcohol hangover phase.

Adult↗
PubMed1981

Carcinoma of the cervix in Newark, New Jersey, 1970-76. A very low in situ: invasive ratio.

Both blacks and whites in Newark had significantly lowered incidences of in situ cervical cancer as compared to the Third National Cancer Survey (TNCS) population. In contrast, Newark blacks' invasive cancer rates were higher than those found in any individual geographic area surveyed in TNCS except for Minneapolis as compared to Newark whites, who had lower rates than all individual TNCS areas except Colorado and San Francisco. Newark blacks had a relative risk of 4.0 for invasive cancer as compared to Newark whites, whereas the corresponding relative risk for blacks versus whites in the TNCS population was 2.0. Newark blacks and whites together had the lowest in situ invasive ratio as compared to women in other parts of the United States. The invasive cancer incidence and mortality rates for both Newark blacks and whites were significantly higher than in the Surveillance, Epidemiology and End Results (SEER) population, but incidence:mortality ratios for Newark and SEER were not different. The most likely explanation for the low in situ rates and high invasive rates among Newark blacks is their failure to obtain Papanicolaou (Pap) smears. The low in situ rate among Newark whites in the absence of a high invasive rate is difficult to explain. It seems that the problem among blacks can be alleviated by the widespread use of Pap smears, which reduce the frequency of invasive cancer and the associated mortality.

Adolescent↗
PubMed1981

[Electrophysiological studies of in vitro cultured endothelial cells from the calf aorta].

The relation between membrane potential (MP) and cell number was studied on cells of a calf aortic endothelial cell line. The intracellular recording of membrane potentials was made with glass microelectrodes. From the 2nd to the 6th day of cultivation the membrane potential increased with the exponentially increasing cell number from --2.8 mV to --9.9 mV. Thereafter the membrane potential decreased. The membrane potential reached its maximum only 1 day after the cell culture had reached its stationary growth phase.

Animals↗
PubMed1980

Fc and C3 receptors as membrane differentiation markers of acute myelogenous leukaemia cells.

Acute myelogenous leukaemia cells (AML) and cells of chronic myelogenous leukaemia blast crisis (CGL-CB) were examined for the presence of receptors for Fc IgG fragment (FcR), receptors for the complement components (CR1 and CR2), and the surface immunoglobulins including the light kappa and lambda type chains. The leukaemia blasts were found to be the cells poor in receptors and poorly differentiated. As a rule, they contained very small amount of detectable FcR, CR2, and CR1. Analysis of AML cell populations separated on the discontinuous density gradient revealed that the appearance of FcR was followed by CR2 and CR1. The CGL-CB cells were more differentiated immunologically since, in comparison with the AML cells, in greater percentage they expressed the FcR, and the receptors for complement. Assays for surface immunoglobulins indicated that they were not an active product of the leukaemic blasts, but rather exogenous in origin.

Complement C3↗
PubMed1980

Gamma-glutamyltransferase in Morris hepatomas 5123D passaged in Buffalo and in F1 (Buffalo x Wistar) rats.

Comparative biochemical and immunological investigations were performed on purified gamma-glutamyltransferase from the Morris hepatoma 5123D and from the 5123D/AS variant passaged in F1 (Buffalo x Wistar) rats. The enzyme was also localized in hepatoma sections by immunofluorescent technique. The obtained results confirm the hypothesis that low gamma-glutamyltransferase activity in Morris hepatoma 5123D/AS is caused by the enzymatic protein defficiency and not by the inhibition of the enzyme.

Animals↗
PubMed1980

Antibody-dependent redistribution and release of immunological complexes in cells of human chronic leukemias.

Redistribution and the ability for removing immunological complexes in CLL and CGL cells treated with the specific anti-leukemia antigens were investigated. The immunofluorescence method at 4 and 37 degrees C was applied at different times of cell incubation with antigens. It was shown, that incubation at 4 degrees C even carried out for 18 h, neither caused a clear aggregation nor a release of immunological complexes from the leukemia cell surface, whereas at 37 degrees C considerable differences in mobility of CLL and CGL cells were observed. In CGL cells quite a rapid redistribution followed by the removal of antigen-antibody complexes was observed, while CLL cells have shown the ability for aggregation only, without clear polarization and without releasing the formed complex from the cell surface.

Antigen-Antibody Complex↗
PubMed1980

Surface immunoglobulins in human chronic leukemia cells.

By means of the cytotoxic and immunofluorescence tests, frequency of various classes of immunoglobulins (IgG, IgA, IgM, IgD, IgE) and light chains was examined in peripheral pathologic blood cells of patients with chronic granulocytic and lymphatic leukemia. The dominant immunoglobulins were of the IgD and IgE classes. Light chains of both types were present in cells of chronic granulocytic leukemia, and kappa type in chronic lymphatic leukemia. Use of the method of resynthesis of digested immunoglobulins in vitro confirmed the monoclonal origin of chronic lymphatic leukemia in humans.

Granulocytes↗