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Biomedical subjects

R Fuchs

Publications and source records attributed to R Fuchs.

At least 73 records · Page 4Linked to original sources
PubMed1997

Brain stem evoked potentials and visual evoked potentials in relation to the length of occupational exposure to low levels of toluene.

In 49 printing-press workers occupationally exposed to toluene for approximately 21.6 years, the values of BEAP and VEP parameters were examined in relation to the length of exposure. With the exception of P2 wave, there was a significant increase in the latencies of all the BEAP waves examined as well as in the interpeak latency (IPL) P3-P4, whereas IPL P4-P5 decreased significantly with the length of exposure. The amplitude of all the VEP examined decreased significantly with the length of exposure. Toluene exposure was evaluated by measuring the concentration of toluene in peripheral blood and of hippuric acid in urine on Wednesday morning prior to the workshift, and of hippuric acid in urine after the workshift on the same day. According to the average concentration of hippuric acid in urine after the workshift, the levels of toluene exposure were estimated to range from 40-60 ppm. Evoked potentials were determined on Mondays 10-12 hours after a nonworking weekend.

Adult↗
PubMed1997

Cognitive evoked potentials VEP P300 persons occupationally exposed to low concentrations of toluene.

Cognitive evoked potentials VEP P300 were examined in 49 workers at printing press occupationally exposed to low concentrations of toluene for averagely 20 years, and in 59 control subjects. The exposure level of toluene was evaluated in randomly selected subgroups comprising 36 exposed and 27 control subjects. The concentrations of toluene were measured in peripheral blood on Wednesday morning before entering the work area, while the hippuric acid in urine was measured before and after entering the work area. The results show that the absolute number of exposed subjects displaying lower amplitude of cognitive wave VEP P300R and prolonged latency of the accompanying spontaneous wave VEP P300F was significantly greater than that of the controls.

Adult↗
PubMed1996

Visual evoked potentials in relation to factors of imprisonment in detention camps.

Visual evoked potentials (VEPs) of the pattern shift reversal type were determined in a representative group of 57 prisoners of war (POWs) released in 1992 from detention camps in former Yugoslavia. The parameters were correlated with the conditions in four camps (1-4). All subjects were male, with a mean age of 34.75 years (SD +/- 8.92), average length of imprisonment 192.7 days (SD +/- 77.6), mean loss of body mass during imprisonment 19.32% (SD +/- 9.54), and the average number of reported blows to the head and neck was 25.7 (SD +/- 20.3). VEPs were determined on average 290.5 days after the last craniocerebral trauma caused by blows to the head and neck (SD +/- 152.0) i.e., on average 218.5 days after release from the camp (SD +/- 164.3). Although all the 57 POWs reported being maltreated to a certain extent, 14 reported being subjected to particularly brutal forms of torture, 5 had been held in solitary confinement and 25 had lost consciousness at least once. Solitary confinement and loss of consciousness had the most significant effect on VEPs, and the altered VEP parameters correlated significantly with the craniocerebral trauma experienced, loss of body mass and the length of time since the last craniocerebral trauma until examination, and from release until examination. However, the length of imprisonment and treatment in the camps did not have a significant effect on VEP parameters. The study confirmed that under such conditions the age of the subject is a risk factor. The results of this study also confirmed that prisoners in one camp had been subjected to the worst maltreatment.

Adult↗
PubMed1996

[Quality assurance by improved cooperation?--Results of a study of prenatal care in Berlin].

Cooperation between the various participants of Public Health services is now recognised as a significant factor to ensure quality in health services. The German system of prenatal care is, because of its heterogenic structure, particularly dependent on a functioning co-ordination between the individual providers of services to pregnant women. However, cooperation between gynaecologists, midwives, social workers and others working in this field in Germany has proved considerably deficient. Within the framework of a qualitative study on the situation of services available to pregnant women in four selected districts of Berlin, a number of decisive barriers to cooperation could be identified, e.g. deficient mutual information among providers, differing concepts of care, as well as different structural and economic conditions of the various members within the health system. On the other hand, a number of different approaches at different levels were perceived which may allow for a better cooperation between the various participants. The results of the study were discussed at conferences attended by regional experts. As a pragmatic aid for the advancement of cooperation, community guides orientated around the needs of pregnant women were drafted for each of the four districts.

Berlin↗
PubMed1995

Toxicokinetics of ochratoxin A in rat following intratracheal administration.

The toxicokinetic parameters of ochratoxin A in rat following intratracheal administration of 50 ng ochratoxin A/g body weight were studied. The absorption of ochratoxin A from the lungs was very efficient. The elimination pattern of the toxin was studied by the analysis of blood samples. The biological half-life of ochratoxin A was 127 h and the calculated apparent volume of distribution equalled 168 ml/kg. The bioavailability of the toxin was very high, 98%. The plasma clearance of the toxin was 0.92 ml/kg.h.

Absorption↗
PubMed1995

Visual evoked potentials in individuals exposed to long-term low concentrations of toluene.

An investigation of visual evoked potentials was carried out in two groups of subjects; 49 workers employed in a printing-prss where toluene has been used exclusively as an organic solvent for the last 30 years, and 59 workers not occupationally exposed to any known neurotoxic substances. The average length of work service in the printing-press was 21.4 years. The level of exposure was assessed by determination of the concentration of toluene in peripheral blood, the concentration of hippuric acid and ortho-cresol in urine in subgroups of subjects chosen at random from both groups. N75, P100 and N145 waves of the pattern reversal visual evoked potentials were analyzed. In the group of exposed subjects, significantly greater amplitudes were found in all waves, with significantly longer latency of the P100 wave.

Alcohol Drinking↗
PubMed1995

Virus-mediated release of endosomal content in vitro: different behavior of adenovirus and rhinovirus serotype 2.

Endosomal penetration by nonenveloped viruses might be accomplished by either local breakdown of the endosomal membrane (e.g., adenovirus) or formation of a membrane-spanning pore by capsid proteins. Uncoating of the nonenveloped virus human rhinovirus serotype 2 (HRV2) has been shown to occur from late endosomes and to be entirely dependent on the acidic pH in this compartment (Prchla, E., E. Kuechler, D. Blaas, and R. Fuchs. 1994. J. Virol. 68: 3713-3723). To investigate further the mechanism of uncoating of HRV2, an in vitro assay was established to test viruses or virus-derived peptides for their capacity to release cointernalized biotin-dextran of different molecular mass (10 and 70 kD) from isolated endosomes. The suitability of the assay was demonstrated by use of a fusogenic peptide derived from influenza virus hemagglutinin (GALA-INF3). Whereas adenovirus induced a low pH-dependent release of up to 46% of the internalized biotin-dextran and did not show any significant size selectivity (as expected for endosome disruption), HRV2 mediated release of 27% of the 10 kD dextran and only traces of the 70-kD dextran. Similarly, GALA-INF3-induced release of biotin-dextran was also size dependent. The potential role of the capsid protein VP1 in HRV2 uncoating in vivo was also substantiated in our in vitro system using an amphipathic, NH2-terminal peptide of VP1. Taken together, these data favor the model of a specific pore-forming mechanism for HRV2 uncoating which is in contrast to the membrane-disrupting mechanism of adenovirus.

Adenoviridae↗
PubMed1995

[Dermatomyositis as a complication of a metastatic melanoma-- case report and review of the literature].

In nearly 60% of men over 50 years of age, dermato-/polymyositis is induced by malignancies. Till now, 9 patients with melanoma-induced dermatomyositis have been reported in the literature. Here we report on a patient suffering from classic pelvic and pectoral girdle proximal weakness, typical heliotrope rash, increased serum CPK values, and biopsy-proven myositis, who died from metastasizing melanoma one year later.

Dermatomyositis↗
PubMed1994

Rat liver endocytic coated vesicles do not exhibit ATP-dependent acidification in vitro.

Coated vesicle fractions from a variety of tissues have been found to contain a vacuolar proton ATPase. Since these fractions contain both plasma membrane- and Golgi-derived coated vesicles, we sought to determine specifically whether endocytic coated vesicles from rat liver contain an active vacuolar proton ATPase. Endocytic vesicles (coated vesicles and endosomes) were selectively labeled with pH-sensitive endocytic tracers (fluorescein isothiocyanate-dextran or -asialoorsomucoid). Coated vesicles were then separated from endosomes by sucrose density gradient centrifugation. Although the endosomal fractions were found to exhibit significant ATP-dependent acidification activity, highly purified coated vesicles containing pH-sensitive endocytic tracers were unable to generate a pH gradient in response to ATP addition. The coated vesicles could be passively acidified, however, by creating potassium diffusion potentials, indicating that they were in fact capable of maintaining proton gradients. Moreover, significant ATP-dependent acidification activity was observed when the coated vesicle fractions were assayed using the nonselective externally added pH probe acridine orange. Thus, it appears that rat liver endocytic coated vesicles do not contain a functional proton pump. The active vacuolar proton ATPase found in these fractions instead reflected the presence of Golgi-derived coated vesicles or contaminating membranes.

Adenosine Triphosphate↗
PubMed1994

Cytokine efficiency in the treatment of high-grade malignant non-Hodgkin's lymphomas: results of a randomized double-blind placebo-controlled study with intensified COP-BLAM +/- rhGM-CSF.

In high-grade malignant non-Hodgkin's lymphomas (hNHL) recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) was evaluated as support to chemotherapy. In a phase III trial, 172 patients (age 18-73 years, stage II-IV) were risk-stratified according to LDH levels and lymphoma size and randomized to receive rhGM-CSF (400 micrograms) (87 patients) or placebo (85 patients) subcutaneously days 8-14 of each cycle of an intensified COP-BLAM regimen. RhGM-CSF significantly reduced the length and nadir of neutropenia, the length of fever episodes, the frequency of all and of severe infections, and of hospitalization and antibiotic requirements. Complete response rates were 63% for all patients and 64% vs. 61% (n.s.) in the rhGM-CSF vs. the control group. Deviations from protocol in applied dosages of myelotoxic drugs and in cycle intervals maintained differed slightly in favor of the rhGM-CSF arm. However, there were no significant differences in overall survival between the GM-CSF treatment and control groups (21 vs. 23 months). Early relapse rates were markedly lower than in the standard-dose COP-BLAM/IMVP-16 regimen. Thus, GM-CSF abates toxic side effects of chemotherapy and may help to maintain dose intensity in high-risk hNHL.

Adolescent↗
PubMed1994

Fast protein block searches.

Profile searches using aligned short protein blocks are an effective method for identifying putative protein functions. An algorithm is presented that accelerates block searches by a factor 2-5 with only limited lack of sensitivity; this algorithm is particularly suited for application in large-scale genome research.

Algorithms↗
PubMed1994

Predicting protein function: a versatile tool for the Apple Macintosh.

A tool is presented that helps to find biological functions for new protein sequences. Running on any Macintosh computer system, MacPattern provides a unique combination of different algorithms, speed and user-friendliness. It supports searches for protein patterns using the PROSITE database, protein block searches with the BLOCKS database, and the identification of statistically significant protein segments. MacPattern allows batch processing of sequences and automatic translations of nucleotide sequence data. It is particularly suited for genome analysis or cDNA sequencing projects.

Algorithms↗
PubMed1994

Sequence analysis by electronic mail: a tool for accessing Internet e-mail servers.

A new utility program, MSU, is described that simplifies the use of electronic mail servers for sequence analysis. Service descriptions are defined in external control files which can be changed without affecting the main program. This approach makes MSU a highly flexible tool that allows easy modification, extension and customization of service descriptions to suit users' personal requirements.

Databases, Factual↗
PubMed1994

Uncoating of human rhinovirus serotype 2 from late endosomes.

The internalization pathway and mechanism of uncoating of human rhinovirus serotype 2 (HRV2), a minor-group human rhinovirus, were investigated. Kinetic analysis revealed a late endosomal compartment as the site of capsid modification from D to C antigenicity. The conformational change as well as the infection was prevented by the specific V-ATPase inhibitor bafilomycin A1. A requirement for ATP was also demonstrated with purified endosomes in vitro. Capsid modifications occurred at a pH of 5.5 regardless of whether the virus was entrapped in isolated endosomes or free in solution. These findings suggest that the receptor is not directly involved in the structural modification of HRV2. Viral particles found in purified endosomes of infected cells were mostly devoid of RNA. This supports the hypothesis that uncoating of HRV2 occurs in intact endosomes rather than by a mechanism involving endosomal disruption with subsequent release of the RNA into the cytoplasm.

Anti-Bacterial Agents↗
PubMed1994

Prognosis of high dose chemotherapy/autologous bone marrow transplantation candidates not receiving this treatment after failure of primary therapy of Hodgkin's disease.

In a multicenter study on the therapy of Hodgkin's disease, in 88 out of 297 patients with primary advanced stages IIIB/IV, a failure to the treatment with the alternating chemotherapy COPP/ABVD +/- radiation was recorded. The cause of failure was as follows: tumor progression under current therapy (PD) 23/88, partial response at the end of therapy (PR) 28/88, early nodal relapses 13/88, late nodal relapses 16/88, extranodal relapses 7/88, undetermined localization 1/88.36 months after manifestation of the failure to treatment, 45% of all patients were still alive. In cases of primary PD the prognosis was the worst of all. Only 1/23 of these patients received a long-term continuous complete remission (cCR) with the salvage therapy. 11 patients with only a nodal relapse received a cCR with irradiation alone. These cases could be regarded as low risk relapses. For the high risk relapse group (n = 57) an indication for high dose chemotherapy with subsequent autologous bone marrow transplantation (HDC/ABMT) would have been imperative, following the present-day definition. The probability of survival of these patients who, however, only received a conventional salvage therapy was up to 38% (95% confidence interval 22-54%). Comparing these data with the literature our results seem not to be substantially worse than those for patients who underwent HDC/ABMT. Only in a randomized comparison can the decision be made on whether HDC/ABMT would be superior to high dose conventional chemotherapy supported by hematopoietic growth factors. It is suggested that such a therapy study be performed as soon as possible.

Adolescent↗
PubMed1994

Database of p53 gene somatic mutations in human tumors and cell lines.

A data base is described in which over 2,500 mutations in the p53 gene of human tumors and tumor cell lines are compiled from a systematic search of reports published before 1 January 1994. Data from 1994 are being added intermittently, with a systematic search and update scheduled for December, 1994. The compilation has been deposited with the EMBL Data Library and is available in electronic form free of charge. This report contains a rationale for the compilation, a brief summary of the major findings and a description of the data base.

DNA Mutational Analysis↗