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Biomedical subjects

R Müller

Publications and source records attributed to R Müller.

At least 685 records · Page 38Linked to original sources
PubMed1983

[Catamnestic studies in sub- and infertile couples].

310 infertile couples have been studied retrospectively over a 15-year period from the andrological and gynaecological view. Teratozoospermia in men and tubal disturbances in women respectively turned out to be the most common causes. Isolated male infertility was found in 33%, that of the female partner in 19%. Both partners were involved in 40%. 93 women (30%) finally gave birth to a child after successful treatment.

Adult↗
PubMed1983

Expression of c-onc genes: c-fos transcripts accumulate to high levels during development of mouse placenta, yolk sac and amnion.

The c-onc genes c-fos and c-fms are expressed at high levels specifically in mouse extra-embryonal tissues. Here, we report the results of a detailed analysis of expression of these genes within the developing placenta and extra-embryonal membranes (i.e., yolk sac and amnion). (i) The c-fos gene is expressed at relatively high, but nearly constant levels in the undissected placenta throughout gestation. (ii) The level of c-fos transcripts is greater than or equal to 15-fold higher in the separated outer portion of the midgestation placenta (primarily undifferentiated fetus-derived cytotrophoblast maternal decidua) relative to the inner moiety (predominantly differentiated syncytiotrophoblast). (iii) In the inner placenta and in the extra-embryonal membranes c-fos transcripts accumulate as gestation proceeds. The abundance of c-fos transcripts in the micro-surgically isolated 18th day amnion reaches a level which is two orders of magnitude greater than that in midgestation fetuses, and is thus close to the level of v-fos transcripts in virus-transformed cells. (iv) The distribution of c-fos transcripts within the developing extra-embryonal tissues is markedly different from that of the c-fms gene. It is suggested that the c-fos and c-fms proteins may participate in differentiation, growth or transport processes occurring in mouse extra-embryonal tissues.

Amnion↗
PubMed1983

[Improvement of Y-values of Hansenula polymorpha growth on methanol by simultaneous utilization of glucose].

The simultaneous utilization of methanol and glucose by Hansenula polymorpha MH20 was investigated in chemostat (C-limited) cultivation. The mixed-substrate utilization results in biomass yields which are greater up to 20 to 25% as expected assuming an additive growth on both substrates. This is referred to as an auxiliary-substrate effect. Additionally, methanol can be utilized at higher growth rates in the presence of glucose compared to those obtained on this substrate alone. The extend of the auxiliary-substrate effect and the optimum ratio of substrates to reach this effect depend on dilution rate. The greatest stimulation in yield is obtained at D approximately 0.1 h-1, after raising the dilution rate this effect diminishes. At a rate of 0.1 h-1 the optimum mixed-substrate ratio of methanol: glucose is 7:1 (g). By increasing the growth rate the ratio changes toward glucose and reached a value of 1:1 (g) at D = 0.3 h-1. This change in the optimum ratio correlates with diminution in yield coefficient of methanol accompanying an increase in growth rate greater than 0.15 h-1. Energy balances of the utilization of the single substrates are used for interpretation of these results. From this it is evident that methanol does not play the role of an energy-rich substrate in the metabolism of yeast. Rather glucose is the energy-providing substrate in this combination.

Ascomycota↗
PubMed1983

Analysis of FBJ-MuSV provirus and c-fos (mouse) gene reveals that viral and cellular fos gene products have different carboxy termini.

The complete nucleotide sequence of the FBJ-MuSV proviral DNA and the cellular homolog (c-fos) of its oncogene (v-fos) have been determined. The 4026 nucleotide long FBJ-MuSV proviral DNA contains two long terminal repeats, a substitution of 1639 nucleotides of mouse cellular DNA (v-fos) and the 3' end of the env gene derived from FBJ-MuLV. The sequences of the parental FBJ-MuLV and the cellular c-fos (mouse) gene share five of five nucleotides at the 5' end and ten of 11 nucleotides at the 3' end of the v-fos substitution. When compared with the v-fos sequences, the c-fos gene contains four discontinuous regions, three of which are flanked by sequences characteristic of introns. Direct sequence analysis of c-fos (mouse) RNA by primer extension demonstrates that the fourth discontinuity is due to a 104 bp deletion in the v-fos gene. As a consequence of the deletion, the predicted v-fos and c-fos gene products differ at their C termini.

Amino Acid Sequence↗
PubMed1983

Physiological changes in carps induced by pollution.

Several pollutants like DDT, atrazine, PCP, and others induce changes of cortisol and glucose levels in serum, variations of the amount of liver glycogen and liver function, and exert changes of the activity of gill ATPase and acetylcholinesterase in brain and serum of carps. There is always a biphasic response, an increase of concentration or enzyme activity for a short time, and a decrease or inhibition of the enzymes after a longer exposure to the pollutants. The time scale, the duration of the period of increase and that of decrease, depends on the concentration and the toxicity of the pollutants. The influence of the pollutants in normal fresh water was compared with the effects occurring in carps acclimated to 1.2% salt water. This condition enables one to show that the carps are more sensitive to the pollutants under this condition. All responses are unspecific. Advice for the use of these tests as criteria for water quality are given.

Acetylcholinesterase↗
PubMed1983

[Computer tomographically guided stereotactic interstitial therapy of brain tumors using temporary or permanent 125iodine seed implantation].

Therapy resistance of inoperable malignant gliomas is an unsolved problem for radiotherapy. A combination of interstitial therapy and percutaneous high voltage therapy is described which should improve the prognosis of brain tumours when it has been perfected. For all tumours of low malignancy we recommend the permanent implantation of 125iodine seeds of low activity (10-60 mCi 125I, DO = 6-10 rad/h.) as the primary form of treatment, possibly supplemented by high voltage therapy. For tumours of higher malignancy, temporary implantation of high activity 125I is indicated (more than 200 mCi, DO = 25-100 rad/h.) as local boost before or after total volume irradiation of brain. Our experience of 30 patients up to date is encouraging.

Adult↗
PubMed1983

Complete nucleotide sequence of a human c-onc gene: deduced amino acid sequence of the human c-fos protein.

The complete nucleotide sequence of the c-fos(human) gene, the human cellular homolog of the oncogene (v-fos) of Finkel-Biskis-Jinkins murine osteosarcoma virus, has been determined. The c-fos(human) gene contains four discontinuous regions when compared with the v-fos gene. Three of the discontinuities are flanked by sequences characteristic of introns, while the fourth discontinuity is due to a deletion of 104 base pairs in the v-fos gene. As a consequence of the deletion, the predicted c-fos(human) and v-fos gene products differ at their carboxyl termini. Transcripts of 2.2 kilobases from the c-fos(human) gene have been identified in human cells. The sizes of these transcripts are in close agreement with the size expected from the nucleotide sequence after removal of introns.

Amino Acid Sequence↗
PubMed1983

Similar rate of O6-ethylguanine elimination from DNA in normal human fibroblast and xeroderma pigmentosum cell strains not transformed by SV40.

Using a highly specific rabbit antiserum (E3) directed against O6-ethyldeoxyguanosine in a competitive radioimmunoassay, we have measured the kinetics of removal of this alkylation product from the DNA of human fibroblasts treated with the N-nitroso carcinogen N-ethyl-N-nitrosourea. A very similar rate of elimination from DNA was found in two normal human fibroblast strains (GM730 and 54BR) and in the nonvirus-transformed xeroderma pigmentosum fibroblast strains XP2BI and XP3BR. This is in contrast to the SV40-transformed xeroderma pigmentosum fibroblast strain XP12RO-SV40 which had previously been shown to be defective in its ability to remove O6-ethylguanine from DNA.

Cell Line↗
PubMed1983

Transcription of c-onc genes c-rasKi and c-fms during mouse development.

We investigated the expression of cellular sequences c-rasKi and c-fms, which are homologous to the oncogenes of Kirsten rat sarcoma virus and the McDonough strain of feline sarcoma virus, during murine development and in a variety of mouse tissues. The c-rasKi gene was found to be transcribed into two mRNA species of approximately 2.0 and 4.4 kilobases, whereas a single c-fms-related transcript of approximately 3.7 kilobases was identified. The c-rasKi gene appeared to be expressed ubiquitously, since similar levels of transcripts were observed in embryos, fetuses, extraembryonal structures, and a variety of postnatal tissues. In contrast, significant expression of c-fms was found to be confined to the placenta and extraembryonal membranes (i.e., combined yolk sac and amnion). The concentration of c-fms transcripts in the placenta increased approximately 15-fold (relative to day-7 to day-9 conceptuses) during development before reaching a plateau at day 14 to 15 of gestation. The time course of cfms expression in the extraembryonal membranes appeared to parallel the stage-specific pattern observed in the placenta. The level of c-fms transcripts in the extraembryonal tissues reached a level which was approximately 20- to 50-fold greater than that in the fetus. These findings suggest that the c-fms gene product may play a role in differentiation of extraembryonal structures or in transport processes occurring in these tissues. Our results indicate that the c-onc genes analyzed in the present study exert essentially different functions during mouse development.

Animals↗
PubMed1983

Novel approach to quantify duodenogastric reflux in healthy volunteers and in patients with type I gastric ulcer.

A new method is described which allows simultaneous measurement of gastric emptying and duodenogastric reflux and avoids transpyloric intubation. After intragastric instillation of a liquid lipid meal in six healthy volunteers the fractional gastric emptying rate was 2.9 +/- 0.3 in the upright and 2.5 +/- 0.6 SEM X 10(-2)/min in the supine position, respectively (p greater than 0.5). The duodenogastric reflux rate (expressed as fraction of the intraduodenal amount of duodenal marker) was 0.30 (range 0.03-0.81) and 0.22 (0.01-0.55) X 10(-2)/min, respectively (p greater than 0.2). Atropine (40 micrograms/kg) decreased the supine gastric emptying rate to 1.1 +/- 0.2 (p less than 0.05) and increased the supine duodenogastric reflux rate to 2.74 (0.04-9.80) X 10(-2)/min (p less than 0.05). Fasting duodenogastric reflux rate was similar in the supine and upright position, 0.49 (0.04-0.89) and 0.42 (0.06-0.97) X 10(-2)/min, respectively (p greater than 0.5). Fractional gastric emptying rate was similar in 10 volunteers and 17 patients with type I gastric ulcer (2.1 +/- 0.4 vs 1.7 +/- 0.2 SEM X 10(-2)/min, p greater than 0.2). Their duodenogastric reflux rates were also similar, 0.65 (0.01-5.24) vs 1.10 (0.01-10.83) X 10(-2)/min (p greater than 0.5). We conclude therefore that (1) gastric emptying and both fasting and postprandial duodenogastric reflux are independent of the posture; (2) fasting and postprandial reflux are of similar magnitude; (3) atropine shows gastric emptying and increases duodenogastric reflux; and (4) patients with type I gastric ulcer have neither slowed gastric emptying nor increased duodenogastric reflux.

Adult↗
PubMed1983

[Visual evoked potentials in pattern motion].

Our intention was to obtain a visual evoked potential (VEP) consisting only of a movement-related component for the purpose of further investigations of movement detection. This was attempted by selection of appropriate stimulus conditions. Evoked by initial movement a VEP with five typical waves was observed at the human occipital scalp. The N2-wave with a peak latency of 180-200 ms was most prominent. Following results were yielded in the experiments carried out: 1. Adaptation to a pattern movement: The amplitude of N2 and P1 is significantly reduced (Fig. 4). 2. Relation between amplitude and velocity: The experimental data could be approximated by a power function with an exponent of m = 0.3 for N2 and lower m for later waves (Fig. 5). 3. Pattern variation (grating, checkerboard, zig-zag) had no influence on N2 but on P1 and possibly also on later waves (Fig. 6). These results suggest that the wave N2 is movement-related under our experimental conditions. A pattern-related component may additionally be assumed in wave P2. Components, evoked by further reasons, may be included in the waves following N2. Their specification demands supplementary experiments.

Evoked Potentials, Visual↗
PubMed1983

Elimination of O6-ethylguanine from the DNA of brain, liver, and other rat tissues exposed to ethylnitrosourea at different stages of prenatal development.

The magnitude of the neurooncogenic effect of N-ethyl-N-nitrosourea (EtNU) in the BD IX rat is strongly dependent on the developmental stage of the nervous system at the time of carcinogen exposure, with a maximum during late prenatal and early postnatal development. Both with increasing postnatal age and in the direction of early embryonic development (prior to Postnatal Day 15), the yield of neuroectodermal tumors in the brain and peripheral nervous system declines sharply. Using a competitive radioimmunoassay for O6-ethyldeoxyguanosine (O6-EtdGuo), we have ascertained that the initial degree of DNA ethylation in BD IX rat tissues (including brain) is independent of the developmental stage at the time of transplacental (i.v.) exposure to a constant single dose of EtNU over a time range from Prenatal Day 11 to a postnatal age of 102 days. O6-EtdGuo is highly persistent in the DNA of peri- and postnatal rat brain but enzymatically removed from the DNA of other tissues, notably liver. The present analyses by radioimmunoassay indicate that O6-EtdGuo is equally persistent in the DNA of prenatal BD IX rats exposed to EtNU (50 micrograms/g body weight) on the 11th, 13th, or 16th day of gestation but removed enzymatically from other prenatal tissues. The rate of removal from the DNA of liver (Prenatal Day 16) is higher than the corresponding rate in 10-day-old (postnatal) BD IX rats. On Prenatal Day 11 to 12 (when a neurooncogenic effect first became apparent after transplacental exposure of BD IX rats to EtNU; S. Ivankovic and H. Druckrey, Z. Krebsforsch., 71: 320-360, 1968), the number of cells per brain is approximately 2 X 10(5). When a limited number of experimental animals are used, and regardless of the incapacity of neural precursor cells to remove O6-EtdGuo from their DNA, this target population size may be incompatible with the manifestation of a rare event such as malignant transformation.

Animals↗