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Biomedical subjects

E Schilling

Publications and source records attributed to E Schilling.

84 records · Page 5Linked to original sources
PubMedDate not supplied

Enrichment of human X- and Y-chromosome bearing spermatozoa by density gradient centrifugation.

Human spermatozoa (120--180 Mill/0.6 ml Tyrode solution) were laid on the top of a continous density gradient column consisting of 4--16% bovine serum albumin. The columns were then centifuged at 1500--1600 rpm (200-240 g) at 20 degrees C or 4 degrees C for 15 min. By this procedure the spermatozoa sedimented within the tubes of normal distribution curves. The mean percentages of y-spermatozoa gradually decreased from 62,3 +/- 6,1% (max. 70%) in the upper fractions to 42,4 +/- 3,8% (min. 37%) in the bottom fractions. These results could be verified by inseminations of rabbit does with spermatozoa separated by the same technique.

Animals↗
PubMedDate not supplied

Failure to separate human x- and y-chromosome bearing spermatozoa by Sephadex gel-filtration.

Human spermatozoa has been filtered on Sephadex gel columns (G 50 fine powder). 50--70% of the spermatozoa put on the gel bed had been recovered within the filtrate, the remaining spermatozoa--not absorbed to gel particles--were found in the upper third of the column. The percentage of motile spermatozoa was higher (80--95%) in the first fraction as compared to the control samples (40--65%). This technique seems to be unsuitable for a successful separation of human x- and y-spermatozoa, an enrichment of x-spermatozoa couldn't be obtained within the first fractions of the filtrate.

Cell Separation↗
PubMedDate not supplied

Effects of sedimentation on soil nutrient dynamics in riparian forests.

The influence of sedimentation rates on biogeochemistry of riparian forests was studied near ephemeral streams at Fort Benning, GA. Upper reaches of seven ephemeral streams had received varying rates of sedimentation stemming from erosion along unpaved roadways at the military installation. Two reference catchments were also included in the study. Decomposition of foliar litter, microbial C and N, N mineralization, and arthropod populations were compared within and among catchments. Rates of sedimentation over the past 25 yr ranged from 0 in references to 4.0 cm yr(-1). Decomposition rates declined exponentially with sedimentation rates as low as 0.20 to 0.32 cm yr(-1) and appeared to reach an equilibrium at a sedimentation rate of 0.5 cm yr(-1). Nitrogen mineralization and microbial C and N followed the same trend. Sedimentation had no discernible effect on arthropod populations. These data suggest that biogeochemical cycles may be altered by sedimentation rates that commonly occur in some floodplain forests.

Animals↗