Inhibition of protein and lipid synthesis in muscle by 2,4-dinitrofluorobenzene, an inhibitor of creatine phosphokinase

A photoaffinity label, 4-azidobenzoyltrimethionine has been synthesized. It competitively inhibits trimethionine uptake in the yeast C. albicans. Upon UV irradiation it irreversibly and specifically blocks oligopeptide uptake. These results give the first example of photoinhibition of peptide uptake in yeast.     

Study of the gametocytocidal/sporontocidal action of qinghaosu (artemisinin) by electron microscopy

The gametocytocidal efficacy of artemisinin (qinghaosu) was evaluated and scanning electron microscopical evidence is given for gametocytocidal action of a single 5-10-mg/kg dose of artemisinin against simian malarial parasite (Plasmodium cynomolgi B). No sporontocidal effect of artemisinin was observed.     

Molecular integrity of monoclonal antibodies produced by hybridoma cells in batch culture and in continuous-flow culture with integrated product recovery

The molecular integrity of monoclonal antibodies (MCAB) produced by murine hybridoma cell line TB/C3 was studied in batch and continuous-flow cultures. In batch culture, one band of MCAB was detected initially by Western blotting of sodium dodecyl sulfate (SDS)-polyacrylamide gels run under unreduced conditions, but heterogenous MCAB bands appeared as the culture aged. The latter were due to the degradation of MCAB by proteases active at the neutral pH of the culture. The deleterious effect of proteases was minimized in the continuous-flow cultures which were integrated for product recovery. The MCAB of high quality was purified over 26 days from a culture grown at a dilution rate of 0.025 h(-1) (experiment 1). However, at a lower dilution rate of 0.015 h(-1) (experiment 2), the integrity of MCAB was compromised after the initial 13 days of culture. This was shown to be due to the variation in the carbohydrate content of MCAB produced, as judged by the increased sialylation of heavy chains and the varied reactivity of MCAB with lectins (Maackia amurensis agglutinin, Galanthus nivalis agglutinin, and Datura stramonium agglutinin) as the age of the culture increased. The concentration of the purified MCAB samples by enzyme-linked immunosorbent assay (ELISA) (used normally) was usually higher than that estimated by absorbance at 280 nm. Best correlation between the two methods (ELISA-280 nm ratio of 1.02-1.25) was obtained with experiment 1 samples. This ratio increased in experiment 2 and batch culture samples as the heterogeneity of MCAB produced increased, being 1.03-2.94 and 2.53-4.62, respectively. Therefore, ELISA overestimated MCAB concentration when the molecular integrity of the latter was compromised. The ELISA-A(280) nm ratio might hence provide a useful indicator for assessing the quality of MCAB produced. Comparison of SDS-polyacrylamide gels stained with Coomassie Brilliant Blue R and silver showed that the former correlated better with the MCAB activity stain, whereas the silver stained both the protein- and carbohydrate-rich components. Comparison of the patterns produced with these two stains might therefore offer another parameter to monitor the overall integrity of MCAB produced. Finally, the data presented have important implications on the validity of using long-term and intensive cultures for generating MCAB because such cultures would be subjected to the additive effects reported for batch and continuous modes of growth. (c) 1993 John Wiley & Sons, Inc.     

Radioimmunoassay of cortisol in peripheral blood plasma of buffaloes peripartum

Changes in the concentration of cortisol were observed in the jugular venous plasma of pregnant buffaloes on days 30, 15, 5, 2 and 1 prepartum, at partum, at regular 6-hr intervals up to 72 hr postpartum and on days 4, 6, 10, 18, 34 and 50 postpartum. A radioimmunoassay (RIA) procedure for cortisol standardized in the laboratory was used. Mean plasma cortisol levels showed little fluctuation (P<0.05) between days 30 and 2 prepartum with the values ranging from 1.28 +/- 0.23 to 1.46 +/- 0.13ng/ml. A small (but nonsignificant) rise in the hormone level was observed one day prepartum followed by a sharp increase to a high mean value of 3.78+/-0.36 ng/ml (P<0.05) at parturition. A sharp decline (P<0.05) to a low mean value was recorded within 6 hr postpartum followed by marked fluctuations in the hormone level up to 72 hr postpartum. The hormone levels subsequently varied narrowly between 1.74+/-0.39 and 2.01+/-0.27 ng/ml up to 50 days postpartum.     

Trace element studies on four species of Fusarium.

Trace element studies were carried out on four species of Fusarium: F. moniliforme, F. solani, F. poae and F. bulbigenum. Out of fifteen trace elements tested, Fe, Zn, Mn, Cu, Mo and B were found to be essential for growth and sporulation of all these species of Fusarium. Optimum concentrations in ppm of essential trace elements of these fungi were as follows: F. moniliforme Fe 1.0, Zn 0.1, Mn 0.1, Cu 0.1, Mo 0.1, B 1.0-10.0; F. solani Fe 1.0, Zn 10.0, Mn 0.1, Cu 0.01, Mo 1.0, B 0.1; F. poae Fe 1.0, Zn 0.1, Mn 0.1, Cu 1.0, Mo 0.1, B0.1, F. bulbigneum Fe 10.0, Zn 1.0, Mn 1.0, Cu 1.0, Mo 0.01, B 1.0. Concentrations higher than the optimum were inhibitory to the respective fungi.     

Balanced structural changes involving the human X: Effect on sexual phenotype

Summary A normal cell line arising from a translocation, t(12;21), possibly by dissociation, was observed in two brothers in early life. Each was conceived as trisomic 21 by their 45,XY,-12,-21,+t(12;21) father, who was phenotypically normal. Each brother showed morphologic manifestations of trisomy 21 syndrome, and each was mildly mentally retarded. Dermatoglyphic indices were not diagnostic of trisomy 21 syndrome. At 4 months the younger brother had a 50:50 proportion of trisomic:normal blood cells which became 25:75 of trisomic 21:normal at 36 months. The older brother had a 25:75 proportion of trisomic 21:normal when first studied at 41/2 years. A similar t(12;21) has not previously been reported. The occurrence of an apparently normal cell line arising spontaneously is unique.