[Stimulated chemiluminescence and degranulation of human polymorphonuclear leukocytes: possible involvement in the mechanisms of tissue damage during inflammation]

A significant increase of polymorphonuclear leukocytes (PMN) chemiluminescence (CL) was observed when PMN was treated with rat C5ades Arg (r-C5ai), FMLP, opsozined zymosan (STZ) or a calcium ionophore A23487 separately. These stimuli, as well as aggregated IgG (A-IgG), could also cause the release of beta-glucuronidase (beta-g) and myeloperoxidase (MPO) from PMN, on the other hand, elastase (NE) release was not noticed when PMN was treated with r-C5ai and FMLP, which generally stimulated PMN in a cytochalasin B-dependent manner. These results suggest that the kinetics of PMN CL and degranulation vary depending upon the stimulus.

Direct electrophoretic detection of the allelic state of single DNA molecules in human sperm by using the polymerase chain reaction

We have developed a procedure that allows the detection of polymerase chain reaction (PCR) products derived from a single target DNA molecule in a human sperm without using radioactive probes. With this method, three genetic loci present in a single sperm can be amplified simultaneously. The amplification procedure is specific as well as efficient and permits detection of the PCR product by ethidium bromide staining after polyacrylamide gel electrophoresis. When allele-specific PCR primers that differ in length are used, the size of the PCR products of different alleles also vary in length, allowing the allelic state at each locus to be determined electrophoretically. Studies on individual sperm by using this procedure should facilitate the measurement of genetic recombination in humans over small physical distances. The ability to directly analyze the allelic state of PCR products from one cell rapidly and simply will also be useful for the prenatal diagnosis of genetic disease, especially in the analysis of single blastomeres taken from in vitro fertilized eggs prior to implantation.

The Escherichia coli Ras-like protein (Era) has GTPase activity and is essential for cell growth

The era gene of Escherichia coli encodes a protein (Era) which is similar to the eucaryotic RAS family of proteins. We report here that purified Era possesses both GTP-binding and GTPase activities. Era is also shown to be loosely associated with the inner membrane of E. coli. Overproduction of Era to 5% of the total cellular protein does not apparently alter either cell growth or cAMP levels. Disruption of the era gene by insertional inactivation is shown to be lethal by construction of a conditional lethal era mutant strain.