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Biomedical subjects

R Fuchs

Publications and source records attributed to R Fuchs.

At least 55 records · Page 3Linked to original sources

Low-level cigarette smoking and longitudinal change in serum cholesterol among adolescents. The Berlin-Bremen Study.

The current study was conducted to determine if smokers and nonsmokers differ in serum concentrations of high-density lipoprotein cholesterol (HDL-C) before smoking initiation and if a decline in HDL-C levels could be detected among adolescents during the first two years of smoking. Changes in HDL-C levels and smoking were observed longitudinally in 1983, 1984, and 1985 among 691 seventh and eighth graders (age range, 12 to 14 years) from two German cities; 82% were nonsmokers at baseline. For these baseline nonsmokers, no differences in baseline HDL-C concentrations were found between those who became smokers and those who remained nonsmokers. In contrast, those who became light (one to 39 cigarettes per week) or moderate (greater than or equal to 40 cigarettes per week) smokers by one or two years after the initial examination evidenced lower mean HDL-C concentrations relative to persistent nonsmokers at follow-up, constituting a decrement of -0.016 mmol/L [SE = .035] (-0.6 mg/dL) [SE = 1.4] for light smokers and -0.114 mmol/L [SE = .064] (-4.4 mg/dL) [SE = 2.5] for moderate smokers. These findings suggest that short-term exposure to cigarette smoke at low levels may have atherogenic consequences.

Adolescent

Two distinct subpopulations of endosomes involved in membrane recycling and transport to lysosomes.

Functionally distinct subpopulations of endosomes involved in targeting internalized material to specific intracellular destinations were resolved as two distinct peaks by free-flow electrophoresis. The less anodally shifted peak contained a population of early endosomes selectively labeled by brief exposures to endocytic tracers or by receptor-bound transferrin. Late endosomes, labeled only after longer periods of internalization, migrated more toward the anode. While both fluid phase and certain receptor-bound markers could be rapidly chased from early to late endosomes, transferrin remained in vesicles comigrating with early endosomes even after prolonged uptake. Thus early and late endosomes are kinetically related but functionally distinct: early endosomes serve as the major site of recycling of membrane and surface receptors and late endosomes are involved in delivery to lysosomes. The subpopulations each contain unique polypeptides not found on the plasma membrane. Thus, endosomes cannot be derived entirely from internalized cell surface components, and may have at least partly independent biosynthetic origins.

Animals

Prognostic risk factors in advanced Hodgkin's lymphoma. Report of the German Hodgkin Study Group.

In a national multicentre trial in the FRG patients with Hodgkin's lymphoma in stages CS/PS III B/IV were entered into the HD 3 protocol and received induction chemotherapy with 3 x (COPP + ABVD). Patients in complete remission (CR) received consolidation therapy by either radiotherapy (20 Gy IF) or chemotherapy (COPP + ABVD). Patients not in CR received salvage therapy (40 Gy in case of persisting nodal disease, else 4 x CEVD chemotherapy). Between July 1983 and May 1987 230 untreated patients aged 15 to 60 qualified for this HD 3 protocol. This analysis is based on the first 137 patients evaluable for response. Of these, 86 (63%) achieved CR after induction chemotherapy. Including salvage therapy a total of 104 patients (76%) achieved CR. Univariate and multivariate prognostic risk factor analyses were performed using freedom from treatment failure (FFTF) as endpoint. Sex, age, splenectomy, bone marrow, liver and bone involvement had no prognostic impact nor had stage according to the Ann Arbor classification. In contrast, a pretreatment erythrocyte sedimentation rate (ESR) above 80 mm/h and a serum alkaline phosphatase (AP) above 230 IU/ml appeared as significant risk factors (p less than 0.01, relative risk 2.3). The two parameters were not independent. Comparing a group A (ESR less than or equal to 80 and AP less than or equal to 230) versus a pooled group B (ESR greater than 80 and/or AP greater than 230) increased the difference (p less than 0.001, relative risk of 2.8) which was also significant for survival (p less than 0.04).

Adolescent

Induction of the SOS function sfiA in E. coli by systems which generate triplet ketones.

Generation of triplet ketones, either chemically through thermal decomposition of 3-hydroxymethyl-3,4,4-trimethyl-1,2-dioxetane and 3-[N-(pyridino)carbamoyl]methyl-3,4,4-trimethyl-1,2-dioxetane++ + or enzymatically via the aerobic oxidation of isobutyraldehyde trimethylsilyl enol ether catalyzed by horse-radish peroxidase, triggers the SOS function sfiA in E. coli. Although the observed effects are relatively weak and the triplet ketone scavenger tryptophan was ineffective in this system, our results provide evidence for the involvement of triplet ketones in this type of DNA damage. Possible mechanisms are discussed.

Antioxidants

Patterns of physical activity among German adolescents: the Berlin-Bremen Study.

Patterns of leisure-time physical activity among 932 West German boys and girls from two distinct socioeconomic groups were examined longitudinally over a 2-year period beginning with seventh to eighth grade students. Activity indices reflect the weekly time spent in activities, the weekly frequency of participation, and the average duration per activity episode. The indices refer to all activities, to moderate or vigorous activities, or to each individual activity. The average seventh to eighth grade student spent 10.1 hr/week engaged in all of the activities measured. Overall, the time devoted to these activities declined by 10% during the 2-year study period, with the relative decrease being larger for vigorous than for moderate activities. The decline in time spent in vigorous activity was due to a decreased frequency of participation; whereas the decline in moderate activity was primarily attributable to the decreased average duration per episode. Boys spent about 3 hr/week more in all activities than girls, with the difference largely being due to the boys' greater participation in vigorous activities. Weekly activity time among girls did not vary substantially with socioeconomic status. However, compared with boys of higher socioeconomic status, boys in the lower socioeconomic grouping were 2-3 hr/wk more active because they devoted more time to moderate activities. The results indicate that the identified activity patterns in the population strongly depend on the activity dimensions on which the measure focuses.

Adolescent

Distribution of 14C-ochratoxin A in the mouse monitored by whole-body autoradiography.

The tissue distribution of 14C-labeled ochratoxin A was studied in mouse using whole-body autoradiography. The distribution was followed for 18 days after one single intravenous injection of 5 microCi/animal, corresponding to 160-230 ng toxin/g body weight. Very long persistence of 14C-ochratoxin A in the circulation was noticed and the toxin was detected in the blood even after 18 days when the experiment was finished. The radioactivity in the kidney was unequally distributed with a slightly higher concentration in the inner cortical and medullary parts. This was seen from 24 hrs and on after injection. Very high concentrations of radioactivity were found in the bile of treated animals. The radioactivity extracted from several sections was chemically characterized with thin-layer chromatography and was found to represent 14C-ochratoxin A.

Animals

Molecular cloning and sequencing of a cDNA coding for mature human kidney cathepsin H.

A cDNA library was established from human kidney RNA and screened with an extended oligonucleotide probe derived from the amino-acid sequence of human cathepsin H. A recombinant clone, pRF15, was isolated and characterized. DNA sequence analysis of its 1106-nucleotide-long insert revealed that pRF15 encodes the complete protein sequence of mature cathepsin H plus 28 amino acids of a propeptide, thus confirming that cathepsin H is synthesized as a larger precursor molecule and posttranslationally processed. Northern blot analysis indicated that cathepsin H is predominantly synthesized in kidney. A high degree of sequence homology was observed with rat cathepsin H, especially within the propeptide. The part of the prosequence coding for the "minichain" is conserved in the prosequence of aleurain, a plant thiol protease.

Amino Acid Sequence

Carbon-14-ochratoxin A distribution in the Japanese quail (Coturnix coturnix japonica) monitored by whole body autoradiography.

Tissue distribution of the nephrotoxic mycotoxin ochratoxin A was characterized in laying Japanese quail by whole body autoradiography and scintillation counting using 14C-labelled toxin. Periodically for 8 days after one intravenous injection of 14 microCi/bird, corresponding to 70 ng/g body weight, birds were killed, frozen, and sagittal sections of the whole body were placed on X-ray film. In general, the ochratoxin disappeared from the avian body rapidly. Specific retention of radioactivity was seen as a ring-like distribution in yolks and growing follicles. After sectioning, organs and intestinal contents were removed from carcasses in a frozen condition, homogenized, extracted, chromatographed, and the radioactivity in fractions was measured by scintillation spectroscopy. High concentrations of ochratoxin A were found in gastric intestinal contents, probably originating from toxin excreted in the bile.

Animals

[Clinical experience with bacterial contamination of Port-A-Cath systems in tumor patients].

In 33 cancer patients with subcutaneously implanted Port-A-Cath systems (Pharmacia) who developed bacteremia with rigor and high fever, aerobic and anaerobic cultures were prepared from aspirated chamber blood. Organisms were isolated from 19 patients of whom 10 had fever, but none life-threatening. In seven patients the fever was caused by infected chamber blood, while in three it was impossible to prove whether it was due to chamber contamination or the underlying disease. Almost all of the causative organisms were skin saprophytes, most frequently Staph. epidermidis, Acinetobacter Iwoffi and apathogenic Corynebacteria. The pathway of infection was probably exogenous (iatrogenic) inoculation. Removal of the catheter system was not necessary. Since strict hygienic measures were instituted when using the system no further chamber contamination has occurred.

Antineoplastic Agents

[The digestibility of crude nutrients in horses. 2. Comparative studies on the digestive capacity of a thoroughbred horse, pony and wether].

The digestibility of the crude nutrients of 6 rations on the basis of oat, hay and wheat straw (in one case a straw-concentrate mixture as sole feed) was compared at a nutrition level of 1.0 and 1.3 resp. with adult geldings of the species "Noble Crossbreed", adult pony geldings and wethers The energy concentration of the rations varied between 424 and 585 EFUcattle/kg DM, the crude fibre content between 17 and 25% of the DM. In the studied field, a good agreement between horse and pony could be ascertained as to the digestibility of the organic matter and NFE. There are partly considerable differences between the apparent digestibility of crude protein and crude fibre. The differences in the digestibility of crude fibre between horse and sheep increase with a growing crude fibre content. The differences of the apparent digestibility between horse and pony on the one hand and sheep on the other were highly significant in all cases.

Animal Feed