Trypanosoma brucei: Miniature anion-exchange centrifugation technique for detection of low parasitaemias: Adaptation for field use.

The miniature anion-exchange/centrifugation (AEC) method, originally developed for the detection of submicroscopic trypanosomaemias in laboratory rodents, has been adapted for the diagnosis of trypanosomiasis in man in the field using blood samples obtained by finger-prick. It has been tested in a survey in The Gambia. The method is shown to be highly sensitive and to fulfil the first essential criteria for exploitation in the field, namely, that it can be operated in the open air under tropical conditions, and that an adequate number of subjects can be examined in a normal working day at an acceptable cost. The method also offers two advantages over the other highly sensitive method applicable to small blood samples, the microhaematocrit buffy-coat microscopy (MBCM) method, namely, that it minimized the requirements for highly critical microscopy and provides, in the same operation, samples of diluted plasma which can be used for serological study.     

Variance in resistance to natural and antibody-dependent cellular cytotoxicity and to complement-mediated lysis among K562 lines

Isolation of sub-populations of the NK-sensitive erythro-leukaemic cell line K562 by limiting dilution techniques has revealed marked clonal variation in susceptibility to natural cytotoxicity. Detailed examination of two such lines (E10/P2 and F9/P2) which differed significantly in their susceptibility to both native and activated NK-cell-mediated lysis revealed that their differences were stable and independent of culture conditions. The resistant (F9/P2) and sensitive (E10/P2) lines had comparable cold-inhibitory and effector-cell adsorption capacities, indicating that differential susceptibility was not attributable to variable expression of NK target structures. F9/P2 was also less susceptible to antibody-dependent cellular cytotoxicity (ADCC) and complement-mediated lysis, indicating the existence of variants with a generalized capacity to resist several immunolytic processes.     

Humoral and cell-mediated immune status in mice exposed to trichloroethylene in the drinking water

A 14-day study using male CD-1 mice exposed to trichloroethylene (TCE) by daily po gavage suggested inhibition of cell-mediated immunity. Therefore, an evaluation of the immune status was undertaken after exposure of male and female mice to TCE in the drinking water for either 4 or 6 months. The immunological parameters assessed were humoral immunity, cell-mediated immunity, lymphocyte responsiveness, bone marrow function, and macrophage function. Females were more affected than males by TCE, particularly after a 4-month exposure. In the female, humoral immunity was inhibited only at the highest concentrations of TCE (2.5 and 5 mg/ml), whereas cell-mediated immunity and bone marrow stem cell colonization were inhibited at all four concentrations of TCE (0.1, 1.0, 2,5, and 5 mg/ml). The males were relatively unaffected after both 4 and 6 months compared to effects observed in the 14-day study.     

The need to decide if all estrogens are intrinsically similar

We used gene expression profiling to investigate whether the molecular effects induced by estrogens of different provenance are intrinsically similar. In this article we show that the physiologic estrogen 17-beta-estradiol, the phytoestrogen genistein, and the synthetic estrogen diethylstilbestrol alter the expression of the same 179 genes in the intact immature mouse uterus under conditions where each chemical has produced an equivalent gravimetric and histologic uterotrophic effect, using the standard 3-day assay protocol. Data are also presented indicating the limitations associated with comparison of gene expression profiles for different chemicals at times before the uterotrophic effects are fully realized. We conclude that the case has yet to be made for regarding synthetic estrogens as presenting a unique human hazard compared with phytoestrogens and physiologic estrogens. Key words: diethylstilbestrol, estrogen, gene expression, genistein, microarray, phytoestrogen, toxicogenomics, uterus.