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K Biedermann

Publications and source records attributed to K Biedermann.

47 records · Page 3Linked to original sources
PubMed1987

Thermal stability of myosin rod from various species.

The radius of gyration and fraction helix as a function of temperature have been determined for myosin rod from four different species: rabbit, frog, scallop, and antarctic fish. Measurements from sodium dodecyl sulfate gel electrophoresis indicate that all particles have the same molecular weight (approximately 130K). All fragments are nearly 100% alpha-helical at low temperatures (0-5 degrees C). The melting profiles for each are qualitatively similar in shape, but their midpoints are shifted along the temperature axis in the following order: antarctic fish (Tm = 33 degrees C), scallop (Tm = 39 degrees C), frog (Tm = 45 degrees C), and rabbit (Tm = 49 degrees C). Corresponding radius of gyration vs temperature profiles for each species are shifted to lower temperatures (approximately 5-8 degrees C) with respect to the optical rotation melting curves. From plots of radius of gyration vs fraction helix, we find a marked drop in the radius of gyration (from 43 to approximately 34 nm) with less than a 5% decrease in fraction helix for rabbit, frog, and antarctic fish rods, whereas the radius of gyration of scallop rod never exceeds 34 nm. Results indicate hinging of the myosin rod of each species. The thermal stabilities of the myosin rods shift in parallel with the working temperature of their respective muscles.

Animals↗
PubMed1987

Two-level factorial screening for influence of temperature, pH, and aeration on production of Serratia marcescens nuclease.

Two high-nuclease-yielding mutants of Serratia marcescens, derived by chemical mutagenesis (W280, W355), and two strains with the pBR322 plasmid 403-SD2, carrying a nuclease gene and a chloramphenicol resistance gene [Escherichia coli CSH50(403-SD2) and S. marcescens CH30(403-SD2)] were investigated for nuclease production in a factorial shake flask experiment, with temperature (30 and 37 degrees C), pH (with or without CaCO3 tablets), and aeration (with or without baffles) as variable conditions. Yields varied 10-fold depending on the conditions investigated.

Aerobiosis↗
PubMedDate not supplied

[Premature labor in HIV infected women. Swiss "HIV and Pregnancy" Study Group].

In the Swiss Study "HIV and pregnancy" we observed 153 singleton pregnancies of HIV-positive women. 23 (15%) of those ended with a premature delivery. For drug addicts (n = 100), the incidence of prematurity, 20%, significantly higher than in those free of drugs (n = 53) with 5.6%. The most frequent cause of prematurity was premature labor or rupture of the membranes (n = 13), followed by maternal illness (n = 8) and fetal complications (n = 2). Women with premature delivery tended to have lower CD4 cell counts than those with term delivery (29.4% vs 12.0% with < 200 CD4 cells/microliters). Low CD4 cell counts and drug consumption are two independent but cumulative risks for severe infections. 16 of the 153 women (12 with, 4 without drug consumption) had severe infections during pregnancy; in 4 cases (25%), this led to prematurity. The most common infection was pneumonia (14/16), further one case of pyelonephritis and one of cerebral toxoplasmosis. Two of these 16 infants (12.5%) were HIV-positive. We could not confirm a relationship between prematurity and vertical HIV transmission. Of the HIV-classified children, 3/18 (16.7%) premature infants and 16/74 (21.6%) term infants were infected.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

[Sodium concentration and pre-eclampsia: is salt restriction of value?].

UNLABELLED: The significance of sodium metabolism with respect to preeclampsia is discussed in the literature with a wide range of diverging opinions. The presented work analyses the influence of a low salt diet on the symptoms of preeclampsia and the consequences for the newborn. MATERIAL AND METHODS: 160 patients with preeclampsia between 1989 and 1993 were retrospectively studied. Serum sodium values (at hospital admission, lowest prepartal level, immediate and 3-8 days postpartum) were compared with the corresponding gestosis symptoms. RESULTS: The mean sodium serum concentration at admission was 135.6 mmol/l (lower norm: 136 mmol/l). This was significantly different from the mean lowest prepartal value of 134.9 mmol/l (p < 0.0001). Postpartum the mean fell again significantly to 134.0 mmol/l (p < 0.0001). None of the parameters for gestosis symptoms, which were investigated (diastolic blood pressure, edema, proteinuria, serum protein levels and hyperreflexia) showed any statistically significant association with the serum sodium concentration. Five patients had very low serum natrium values, 130 mmol/l, either at admission or during hospitalisation. Three of the five infants of these patients had hyponatremia; two needed sodium supplementation. CONCLUSION: There seems to be no reason supporting a low salt diet as therapy for preeclampsia, since it does not affect the symptoms and might lead to hyponatremia in the newborn.

Adult↗