Linda L. Nolan

Activity of Edible Mushrooms Against the Growth of Human T4 Leukemic Cancer Cells, HeLa Cervical Cancer Cells, and Plasmodium falciparum

ABSTRACT Several edible Hymenomycete mushroom species have been screened as possible inhibitors of human T4 leukemic cancer cells, HeLa cervical cancer cells, Plasmodium falciparum (a pyrimethamine resistant malarial parasite), and six pathogenic microorganisms. Grifola frondosa, Ganoderma lucidum, Lentinula edodes, and Laetiporus sulphureus demonstrated activity against human T4 leukemic cancer cells. Grifola frondosa, Ganoderma lucidum, Lentinula edodes, and Lentinula aurantiacum demonstrated activity against HeLa cervical cancer cells. Pofyporus umbellatus, Russula xerampelina, Ganoderma lucidum, Trametes versicolor, Lentinula aurantiacum, Laetiporus sulphureus, Boletus variipes. Boletus queletii, Grifola frondosa, and Lentinula edodes demonstrated activity against Plasmodium falciparum. No activity was observed against the pathogenic microorganisms.

Isolation and partial characterization of a high-molecular-weight DNA polymerase from Leishmania mexicana

This paper describes for the first time the isolation and characterization of a high-molecular-weight predominant DNA polymerase from the genus Leishmania, which are parasitic flagellated protozoa. Like mammalian DNA polymerase alpha, the leishmanial DNA polymerase, designated DNA polymerase A, is of high-molecular-weight, is sensitive to N-ethylmaleimide and is inhibited by high ionic strength. Unlike mammalian DNA polymerase alpha, but similar to the predominant DNA polymerase isolated from the related lower eukaryotic organisms, Trypanosoma cruzi and Crithidia fasciculata, the leishmanial DNA polymerase A is resistant to inhibition by aphidicolin, a potent inhibitor of DNA replication in mammalian cells and of DNA polymerase alpha. The DNA polymerase A was purified 28,000-fold and properties such as pH optimum, salt sensitivity, template requirements and response to DNA polymerase inhibitors were determined. A low-molecular-weight DNA polymerase was detected during the isolation procedures, but was separated from the polymerase A activity. Differences in responses to specific antisera and specific mammalian DNA polymerase alpha inhibitors suggest that the leishmanial high-molecular-weight A enzyme is sufficiently different to suggest this enzyme as a chemotherapeutic target.

Partial purification and characterization of guanine aminohydrolase fromtrypanosoma cruzi

Guanine deaminase (guanine aminohydrolase, EC 3.5.4.3) catalyzes the hydrolytic deamination of guanine to xanthine. A rapid procedure for the partial purification of guanine deaminase fromTrypanosoma cruzi using granulated bed electrofocusing was developed. Supernatants of cell sonicates (40,000 g) were subjected to electrofocusing with a broad range ampholyte (pH 4–9). Sections of the gel were eluted and assayed for xanthine production. Active fractions were pooled, concentrated, and again subjected to electrofocusing with a pH 5–7 range ampholyte. This procedure resulted in over 240-fold purification. The compounds 4-amino-5-imidazolecarboxamide andN6-methyladenine were found to be potent competitive inhibitors of the enzyme. Their respective Ki values were 3.5×10−6M and 9.5×10−6M. Irreversible inactivation of the enzyme was observed upon incubation withp-chloromercurophenylsulfonic acid andN-ethyl-maleamide at 5.0×10−4M. The enzyme was labile to heat; a substantial loss of activity occurred upon incubation at 55°C for 5 min. A broad pH range of activity (pH 7.5–8.5) was observed in Tris, citrate, and phosphate buffers.

A rapid in vitro system for screening the effect of experimental compounds on nonadhering cell lines

A simple in vitro method was developed to assess the toxic effect of experimental compounds, with two nonadhering cell lines, a parasitic protozoan,Leishmania mexicana (promastigote), and human lymphocyte CEM T4 cells. The technique developed involves growth of cells in a 96-well microwell plate and monitoring of turbidity. This technique requires the use of a chemically defined medium, nonadhering cells, and a microwell spectrophotometer. The method is rapid, simple, and can, in principle, be easily applied to determine the effect of test agents on any nonadhering cell line or microorganism.

The world's favorite beverage-coffee-and health

ABSTRACT Coffee, with its aromatic appeal and distinctive flavor, is the worlds favorite beverage. Throughout history, coffee has been known to delight and stimulate the senses, comfort the spirit, and encourage conversation and camaraderie. This review explores the legend, history, economics, and health of this drink from its origin in Ethiopia to its worldwide consumption today and summarizes current knowledge on its beneficial effects and possible risks. Caffeine, the major constituent of coffee, is also found in other popular beverages (cola-containing soft drinks, tea) and nonprescription pharmaceutical preparations; Innumerable studies have been conducted on the major ingredient of coffee-caffeine-and much experimental, clinical, and epidemiological data has been accumulated. This chapter summarizes current knowledge on the health effects of coffee/caffeine on the central nervous and cardiovascular systems and the effect of caffeine on reproduction, bone loss-and cellular division.

Radiation safety survey at universities, colleges and research facilities

Abstract Radiation Safety Programs at universities and colleges in the United States are responsible for the use, transport, and disposal of radioactive materials within the academic setting. The Radiation Safety Program must be designed in such a way as to ensure the safe use of radioactive material and minimum radiation exposure to radionuclide users. As part of a needs assessment to study the incidents and accidents related to use of radioactive material which occur in the academic setting, a Radiation Safety Questionnaire was sent to Radiation Safety Officers in the United States. Twenty percent of the surveys were addressed to research facilities for comparison purposes. Accidents and incidents involving the use of radiation were analyzed and correlated to the number of Radiation Safety Officers (RSOs) employed, support staff, and size of student body. Radiation Safety Program strength was compared with NRC violations to relate program capability with results. Data suggests an association between the...