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At least 19 recordsLinked to original sources
PubMed1975

Zeta sedimentation ratio in rheumatic disease. Comparison of the zeta sedimentation ratio with the Wintrobe and Westergren sedimentation rates.

The zeta sedimentation ratios (ZSR) of 104 normal subjects and 106 rheumatology clinic patients were compared with their Westergren and Wintrobe erythrocyte sedimentation rates (ESR). The mean ZSR for normal subjects was 49.42 +/- 3.75%. The rheumatology clinic patients were separated into noninflammatory and inflammatory disease groups. The mean ZSR values for these groups were: noninflammatory, 51.60 +/- 5.33%; inflammatory, 59.43 +/- 7.32% (t = 5.5, p less than 0.001). The correlation between ZSR and ESR values was excellent. The ZSR determination has several advantages over the standard ESR in that it can be performed on blood anticoagulated with EDTA and need not be corrected for age, sex or packed cell volume. The ZSR is a rapid, reproducible test correlating well with rheumatic disease activity.

Adult↗
PubMed1978

Use of ethidium bromide fluorescence enhancement to detect duplex DNA and DNA bacteriophages during zone sedimentation in sucrose gradients: molecular weight of DNA as a function of sedimentation rate.

Duplex DNA molecules and DNA bacteriophages have been sedimented through 5--25% sucrose gradients containing ethidium bromide. The location of DNA within the gradients has been determined by illuminating gradients with ultraviolet light and observing the ethidium bromide fluorescence enhancement induced by the DNA. The relative sedimentation rates of linear, duplex DNAs from bacteriophages T4, T5, T7 and an 8.3% T7 deletion mutant have been determined. The distances sedimented by DNA have been corrected, when necessary, for a progressive decrease in sedimentation rate that occurs after the DNA has traversed 40% of the sucrose gradient. The corrected distances sedimented by two DNA molecules, r1' and r2', are related to the DNA molecular weights, m1 and m2, by the equation: r1'/r2' = (m1/m2)0.38 when 0.025--0.70 microgram of each type of DNA is sedimented. Intact bacteriophages were also sedimented in ethidium bromide--sucrose gradients and detected by fluorescence enhancement.

Centrifugation, Density Gradient↗
PubMed1975

[The mechanism of blood cell sedimentation. XVIII. Sedimentation effect of fibrinogen plasminolysis products].

Various high molecular weight plasmin degradation products of fibrinogen were isolated by chromatographic procedures and investigated to what extent they influence the sedimentation rate of erythrocytes in heparinized serum. Among the early plasminolysis products Fragment X accelerated the sedimentation rate considerably although it was less effective than fibrinogen. Fragment Y showed a weaker but clearly demonstrable agglomerine activity. The late plasminolysis products D and E were ineffective, if applied alone and in concentrations equivalent to the fibrinogen content of plasma. However, they promoted the sedimentation effect of fibrinogen. If present in considerably higher concentrations are Fragments D and E, in absence of fibrinogen, also accelerated the sedimentation rate of erythrocytes significantly. A mixture of D and E was not more effective than the single compounds.

Blood Sedimentation↗
PubMed1978

Sedimentation of multicomponent viruses: evaluation of sedimentation coefficient ratios.

Ratios of the sedimentation coefficients for alfalfa mosaic virus components are shown to be independent of the virus concentration and the density of the solvent. Different numbers of components are observed in solvents of different density. This implies that in sedimentation velocity experiments an estimate of the number of components of a multicomponent virus should involve centrifugation in solvents of different density. For some viruses, estimates of the sedimentation coefficients of individual components can be obtained from the coefficient ratios observed in unfractionated solutions and the sedimentation coefficient of the most easily purified component.

Centrifugation, Density Gradient↗
PubMed1975

Zeta sedimentation ratio (ZSR), a replacement for the erythrocyte sedimentation rate (ESR).

The zeta sedimentation ratio (ZRS) was evaluated and found to have advantages over the erythrocyte sedimentation rate (ESR). The normal range for the ZSR proved to be 41 to 54%. Elevated ESR's obtained with the modified Westergren technic were also associated with an increased ZSR, except when amenia spuriously elevated the ESR. Reproducibility after storage was slightly better for the ZSR than for the ESR, But for optimal results the test should be performed within two hours of phlebotomy. Increased concentrations od EDTA anticoagulant may falsely elevate the ZSR, especially if the ZSR is initially elevated.

Adult↗
PubMedDate not supplied

Comparison of zeta sedimentation ratio with Westergren sedimentation rate.

Zeta sedimentation ratio (ZSR) is a simple, rapid and reproducible test which is not influenced by variables like sex and anemia. There is good correlation with Westergren erythrocyte sedimentation ratio (ESR) in normal and hospital population. Limitation of packing force affects the use of the procedure in polycythemia and in patients with ZSR greater than 80%.

Anemia↗
PubMed1976

Temperature limitation of methanogenesis in aquatic sediments.

Microbial methanogenesis was examined in sediments collected from Lake Mendota, Wisconsin, at water depths of 5, 10, and 18 m. The rate of sediment methanogenesis was shown to vary with respect to sediment site and depth, sampling date, in situ temperature, and number of methanogens. Increased numbers of methanogenic bacteria and rates of methanogenesis correlated with increased sediment temperature during seasonal change. The greatest methanogenic activity was observed for 18-m sediments throughout the sampling year. As compared with shallower sediments, 18-m sediment was removed from oxygenation effects and contained higher amounts of ammonia, carbonate, and methanogenic bacteria, and the population density of methanogens fluctuated less during seasonal change. Rates of methanogenesis in 18-m sediment cores decreased with increasing sediment depth. The optimum temperature, 35 to 42 C, for sediment methanogenesis was considerably higher than the maximum observed in situ temperature of 23 C. The conversion of H2 and [14C]carbonate to [14C]methane displayed the same temperature optimum when these substrates were added to sediments. The predominant methanogenic population had simple nutritional requirements and were metabolically active at 4 to 45 C. Hydrogen oxidizers were the major nutritional type of sediment methanogens; formate and methanol fermentors were present, but acetate fermentors were not observed. Methanobacterium species were most abundant in sediments although Methanosarcina, Methanococcus, and Methanospirillum species were observed in enrichment cultures. A chemolithotropic species of Methanosarcina and Methanobacterium was isolated in pure culture that displayed temperature optima above 30 C and had simple nutritional requirements.

Cell Count↗