The effect of caffeine on repair was studied in the green alga Chlamydomonas reinhardtii. Treatment of UV-irradiated wild-type (UVS+) cells with a sublethal level of caffeine caused a significant increase in survival compared to untreated UV-irradiated cells. Caffeine did not affect survival in the repair-deficient strain UVSE1, which is deficient in repair of UV-induced damage carried out by enzymes associated with recombination during meiosis. A significant increase in survival in the presence of caffeine was observed in the repair-deficient strain UVSE4 in which recombination during meiosis is not affected. Treatment of zygotes homozygous for UVS+, UVSE1, or UVSE4 with sublethal levels of caffeine caused marked increases in recombination frequency in UVS+ and UVSE4 zygotes and no increase in recombination in UVSE1 zygotes. These results indicate that caffeine increases recombination in normal strains. Increased opportunity for recombination caused by caffeine would not result in increased recombination frequency in the UVSE1 strain, assuming limited-recombination enzyme activity in this strain. The observed increase in survival following UV-irradiation in the presence of caffeine in strains having normal recombination would therefore be associated with a caffeine-induced increase in opportunities for recombination repair.

Caffeine↗

PubMed1977

The (?) value of routine skull radiography in clinical evaluation of children with recurrent convulsions.

Explore the source record for details and available documents.

Child↗

PubMed1977

Nutritional effects of salmonellosis in mice.

Mice infected with a standard challenge of Salmonella typhimurium manifest a number of changes associated with endotoxemia. These changes result in profound alterations in the nutritional and metabolic status of the host. Food and water intake approaches levels of total inanition, blood glucose declines more rapidly than in fasted controls, hepatic phosphoenolpyruvate carboxykinase (the enzyme that is rate limiting in gluconeogenesis) shows diminished activity and loss of cortisol inducibility, and hypothermia, rather than hyperthermia, becomes acute. These changes occur at a time when bacteremia is first demonstrable. This occurs on the 3rd day after infection under the conditions employed. Death occurs in most mice within the next 24 to 48 hr. Mice vaccinated with a highly immunogenic ribosomal preparation and subsequently infected with the standard number of organisms did not manifest the above changes. Other work from this laboratory has established that effects of the type described are elicited by bacterial endotoxin as a result of mediating substances released into the blood by cells of the reticuloendothelial system. Presumably these substances appear in blood of infected mice as well.

Animals↗

PubMed1977

Some applications of the law of evidence to the specialty of radiology.

Certain rules or laws of evidence are particularly applicable to diagnostic images in whatever form they are used in court as evidence. The legal principles and precedents of this subject, including opinion evidence, hearsay evidence rule, best evidence rule, and the role of the radiologist as a medical expert witness, are discussed.

Expert Testimony↗

PubMed1976

The syndrome of bronchial atresia or stenosis with mucocele and focal hyperinflation of the lung.

Three cases of "the syndrome of bronchial atresia or stenosis with mucocele and focal hyperinflation of the lung" are added to 28 proven cases (26 with atresia and 2 with stenosis) previously reported in the English literature. One case is of particular interest since serial roentgenograms during the first week of life showed fetal lung fluid to be trapped distal to the atresia. The radiographic findings in this syndrome are reviewed and the presumed etiology and pathophysiology discussed.

Body Fluids↗

PubMed1975