The "Nobel": Prize and swindle. The betrayed testament

Human glutathione S-transferase pi (GST-pi) may serve as a useful tumor marker because of the high frequency with which it is found in elevated levels in several tumor types. To determine whether GST-pi is useful as an indicator for cancers of the head and neck, expression of GST-pi mRNA was investigated by Northern analysis in this tumor type. Overexpression of GST-pi mRNA was detected in 9 of 36 (25%) primary head and neck squamous cell carcinomas (HNSCCs). When Southern blot analysis was used to examine the relationship between overexpression and amplification of the GST-pi gene, only 3 of 36 tumors (8%) showed GST-pi gene amplification. Thus, gene amplification is not critical to GST-pi mRNA overexpression in HNSCCs. Moderately and poorly differentiated HNSCCs tended to manifest elevated GST-pi mRNA compared with well differentiated tumors (30% for moderately and poorly differentiated tumors versus none of the well differentiated tumors examined). However, there was no significant correlation between GST-% mRNA overexpression and clinical stage, T stage (tumor size), N stage (neck nodal status), pathological nodes, or patient survival.     

A role for B cells in the development of T cell helper function in a malaria infection in mice

B cell knockout mice are unable to clear a primary erythrocytic infection of Plasmodium chabaudi chabaudi. However, the early acute infection is controlled to some extent, giving rise to a chronic relapsing parasitemia that can be reduced either by drug treatment or by adoptive transfer of B cells. Similar to mice rendered B-cell deficient by lifelong treatment with anti-mu antibodies, B cell knockout mice (muMT) retain a predominant CD4+ Th1-like response to malarial antigens throughout a primary infection. This contrasts with the response seen in control C57BL/6 mice in which the CD4+ T-cell response has switched to that characteristic of Th2 cells at the later stages of infection, manifesting efficient help for specific antibodies in vitro and interleukin 4 production. Both chloroquine and adoptive transfer of immune B cells reduced parasite load. However, the adoptive transfer of B cells resulted in a Th2 response in recipient muMT mice, as indicated by a relative increase in the precursor frequency of helper cells for antibody production. These data support the idea that B cells play a role in the regulation of CD4+ T subset responses.     

The stationary-phase-exit defect of cydC (surB) mutants is due to the lack of a functional terminal cytochrome oxidase

The surB gene was identified as a gene product required for Escherichia coli cells to exit stationary phase at 37 degrees C under aerobic conditions. surB was shown to be the same as cydC, whose product is required for the proper assembly and activity of cytochrome d oxidase. Cytochrome d oxidase, encoded by the cydAB operon, is one of two alternate terminal cytochrome oxidases that function during aerobic electron transport in E. coli. Mutations inactivating the cydAB operon also cause a temperature-sensitive defect in exiting stationary phase, but the phenotype is not as severe as it is for surB mutants. In this study, we examined the phenotypes of surB1 delta(cydAB) double mutants and the ability of overexpression of cytochrome o oxidase to suppress the temperature-sensitive stationary-phase-exit defect of surB1 and delta(cydAB) mutants and analyzed spontaneous suppressors of surB1. Our results indicate that the severe temperature-sensitive defect in exiting stationary phase of surB1 mutants is due both to the absence of terminal cytochrome oxidase activity and to the presence of a defective cytochrome d oxidase. Membrane vesicles prepared from wild-type, surB1, and delta(cydAB) strains produced superoxide radicals at the same rate in vitro. Therefore, the aerobic growth defects of the surB1 and delta(cydAB) strains are not due to enhanced superoxide production resulting from the block in aerobic electron transport.     

Stable Oxygen and Carbon Isotopic Compositions of Lates stappersii Otoliths from Lake Tanganyika,East Africa

In this study, we measured growth trends in oxygen and carbon isotopic ratios in whole sagittal otoliths from three adult centropomid fish (Lates stappersii) from each of three sub-basins of Lake Tanganyika, East Africa. Sampling density was 20 to 50 samples per otolith. Both δ¹⁸O and δ¹³C values increase with age. The δ¹⁸O data suggest that otoliths were precipitated near the expected equilibrium with the ambient environment (ca. +3.5‰) and support a migration pattern from surface waters during larval stages to deeper waters (40 to 80 m) for mature fish. Relatively high δ¹⁸O values in the southern sub-basin are consistent with cooler temperatures in the region during seasonal upwelling. The δ13C increase from otolith core to edge is large (up to 4‰) and is interpreted as due to ontogenetic changes in diet and contributions from a decrease in the proportion of respired CO₂ incorporated into otolith carbonate as metabolic rates of the fish dropped with maturity. The data seem to successfully reveal life strategy and migration patterns of L. stappersii, document regional differences in lake conditions, and provide a record of temperature within the water column during which the fish lived. Higher resolution studies and analyses of historical samples could be used to constrain modern and past growth patterns, and to reconstruct past temperature gradients and productivity patterns in the lake.     

HPLC–MS analysis of the green food colorant sodium copper chlorophyllin

Five commercial samples of sodium copper chlorophyllin, a green food colorant, were analysed by high-performance liquid chromatography (HPLC) using diode-array detection (DAD) and mass spectrometry (MS). Some of the constituents were identified using authentic standards, whereas others were identified tentatively based on their absorption spectra and mass data. The composition of three of the samples was very similar, whereas the other two were quite different. In the three former samples, the three largest peaks could be assigned to Cu chlorin e₆, Cu chlorin p₆, and Cu isochlorin e₄. In one of the two other samples, these three compounds were also among the largest peaks, whereas Cu chlorin e₆ was a small peak in the last sample and Cu chlorin p₆ was absent altogether. Porphyrins were also present in the samples, while except in one of the samples chlorins derived from chlorophyll b were largely absent.Industrial relevanceSodium copper chlorophyllin is a green food colorant made from chlorophyll. Sodium copper chlorophyllin is made by saponifying chlorophyll and coppering the resulting product. This processing leads to a complex mixture of compounds. An analytical method was developed that can be used to identify many of these compounds and show the extent of coppering and degradation of sodium copper chlorophyllin, which may be used industrially to optimize the production of sodium copper chlorophyllin.