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PubMedDate not supplied

A new separation method of subcellular fractions of boar spermatozoa.

A new procedure for the isolation of acrosomal membranes of boar spermatozoa by centrifugation in modified colloidal silica gradients is described. The carbohydrate composition of the membrane fractions is reported. The acrosomal membrane fraction (Mf 1) contains about 10% carbohydrates which are composed of fucose, mannose, galactose, N-acetylglucosamine, N-acetylgalactosamine and N-acetylneuraminic acid in the molar ratio 1:3:6:4.5:2:3.

Acrosome↗
PubMed1987

Effects of cerebral ischemia on [3H]inositol lipids and [3H]inositol phosphates of gerbil brain and subcellular fractions.

Intracerebral injection of [3H]inositol into gerbil brain resulted in labeling of phosphoinositides and inositol-phosphates in various subcellular membrane fractions. Phosphatidylinositol (PI) comprised greater than 90% of the radioactivity of inositol lipids. However, the level of labeled poly-PI (with respect to PI) was higher in synaptosomes than in other membrane fractions. Ischemia induced in gerbils by ligation of the common carotid arteries resulted in a 30% decrease in labeled poly-PI in brain homogenates and this decrease was largely attributed to the poly-PI in synaptosomes (50% decrease). Among the inositol phosphates, the ischemia induction resulted in a decrease in labeling of inositol triphosphate (63%) and inositol biphosphate (38%), but labeling of inositol phosphate (IP) was increased by 59%. The results suggested a rapid turnover of the inositol phosphates in the gerbil brain. In general, changes in inositol lipids and inositol phosphates due to ischemia were attenuated after pretreatment with lithium (3 meq/kg) injected intraperitoneally 5 h prior to ligation. Surprisingly, lithium treatment alone did not cause an increase in IP labeling in the gerbil brain.

Animals↗
PubMed1978

Subcellular fractions for immunizing against pertussis.

Differential centrifugation was used to prepare fractions from broken cells of Bordetella pertussis strain 114. Whole cells and several fractions were then assayed for potency and for safety. Crude ribosomal fractions were uniformly protective. However, ribosomes purified by washing in high salt solution and recentrifugation were at least 40 fold less potent. Protective antigen was found in the wash fluid. Wash fluid was subjected to SDS-polyacrylamide gel electrophoresis. No specific protein or carbohydrate has yet been identified as a protective immunogen. It is clear that ribosomes are not protective, but copurify with protective antigen. SDS-polyacrylamide gel analysis of soluble material purified from ribosomes may be of value in experimental studies on pertussis vaccine. If the protective immunogen can be identified, this procedure may also be of value in vaccine standardization.

Animals↗
PubMed1977

Application of enzymehistochemical methods to isolated subcellular fractions and to sucrose-ficoll density gradients. A contribution to the comparison of histochemical and biochemical data.

To compare histochemical and biochemical determinations of enzyme activities, enzymehistochemical procedures are applied to sections of pellets of subcelluar fractions. These investigations are of value to determine the subcellular localization of histochemically demonstrable enzyme activities and to test the homogeneity of an isolated fraction. In homogenating duckling liver a great part of the endothelial cells is not destructed and consequently is found in the nuclear fraction. Kupffer cell lysosomes land in the heavy mitochondrial fraction, whereas hepatocyte lysosomes are chiefly found in the light mitochondrial fraction. beta-Glucuronidase activity shows a preferentially microsomal localization. Application of enzymehistochemical staining reactions to discontinuous gradients and comparison with biochemical data provides additional information about the validity of an enzymehistochemical reaction. In rat liver the tetrazolium reductases show a distinctly dual localization: activity in the mitochondrial band and in microsomal bands. As to their localization in different bands of the gradients non-specific esterases demonstrate a clear pH-dependency.

Acetylglucosaminidase↗