A laboratory approach for characterizing chronic fatigue: what does metabolomics tell us?

Metabolomics - Pre-eclampsia is a hypertensive gestational disorder that affects approximately 5% of all pregnancies. As the pathophysiological processes of pre-eclampsia are still uncertain, the...     

Effects of a prudent diet containing either lean beef and mutton or fish and skinless chicken on the plasma lipoproteins and fatty acid composition of triacylglycerol and cholesteryl ester of hypercholesterolemic subjects

In this two-phase crossover study, 39 hypercholesterolemic subjects followed a prudent diet with either lean red meat or fish and skinless chicken (treatment groups), and 13 subjects (reference group) followed their habitual diet. Fasting blood samples were analyzed for plasma total cholesterol, triacylglycerol (TAG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein one- and two-cholesterol, apolipoprotein-B, very low density lipoprotein cholesterol, and very low density lipoprotein TAG, and fatty acid composition of plasma TAG and cholesteryl ester (CE). Body mass and blood pressure were determined. Seven-day dietary records were kept once at baseline and twice during the treatment periods. Significant differences were observed in dietary intake between the baseline and treatment diets and between the two treatment diets. HDL-C (P < 0.05) and diastolic blood pressure (P < 0.01) were higher in patients on the red meat diet than in those on the chicken-fish diet. No other significant differences in lipoproteins were observed between the effects of the two treatment diets. The linoleic acid (%), eicosapentaenoic acid (%), and the eicosapentaenoic acid/arachidonic acid ratios in TAG and CE were higher (P < 0.01) in subjects on the chicken-fish diet than in those on the red meat diet. In conclusion, this study showed that the effect of two lipid-lowering diets containing either lean red meat or skinless chicken and fish on the atherogenic lipoproteins did not differ significantly. A prudent diet with skinless chicken and fish, however, had a more favorable effect on the fatty acid composition of the plasma TAG and the CE than did the lean red meat diet.     

In vitro effects of 2‐methoxyestradiol‐bis‐sulphamate on the non‐tumorigenic MCF‐12A cell line

A priority in recent anti‐cancer drug development has been attaining better side‐effect profiles for potential compounds. To produce highly specific cancer therapies it is necessary to understand both the effects of the proposed compound on cancer and on normal cells comprising the rest of the human body. Thus in vitro evaluation of these compounds against non‐carcinogenic cell lines is of critical importance. One of the most recent developments in experimental anti‐cancer agents is 2‐methoxyestradiol‐bis‐sulphamate (2ME‐BM), a sulphamoylated derivative of 2‐methoxyestradiol. The aim of this study was to evaluate the in vitro effects of 2ME‐BM on cell proliferation, morphology and mechanisms of cell death in the non‐carcinogenic MCF‐12A breast epithelial cell line. The study revealed changes in proliferative capacity, morphology and cell death induction in response to 2ME‐BM exposure (24 h at 0.4 µM). Microscopy showed decreased cell density and cell death‐associated morphology (increased apoptotic characteristics), a slight increase in acidic intracellular vesicles and insignificant ultra‐structural aberrations. Mitotic indices revealed a G₂M‐phase cell cycle block. This was confirmed by flow cytometry, where an increased fraction of abnormal cells and a decrease in cyclin B1 levels were observed. These results evidently demonstrate that the non‐carcinogenic MCF‐12A cell line is less susceptible when compared to 2ME‐BM‐exposed cancer cell lines previously tested. Further in vitro research into the mechanism of this potentially useful compound is warranted. Copyright © 2010 John Wiley & Sons, Ltd.     

A Dichotomy in Cortical Actin and Chemotactic Actin Activity between Human Memory and Naive T Cells Contributes to Their Differential Susceptibility to HIV-1 Infection

Human memory and naive CD4 T cells can mainly be identified by the reciprocal expression of the CD45RO or CD45RA isoforms. In HIV-1 infection, blood CD45RO memory CD4 T cells are preferentially infected and serve as a major viral reservoir. The molecular mechanism dictating this differential susceptibility to HIV-1 remains largely obscure. Here, we report that the different susceptibility of memory and naive T cells to HIV is not determined by restriction factors such as Apobec3G or BST2. However, we observed a phenotypic distinction between human CD45RO and CD45RA resting CD4 T cells in their cortical actin density and actin dynamics. CD45RO CD4 T cells possess a higher cortical actin density and can be distinguished as CD45RO⁺Actin^high. In contrast, CD45RA T cells are phenotypically CD45RA⁺Actin^low. In addition, the cortical actin in CD45RO memory CD4 T cells is more dynamic and can respond to low dosages of chemotactic induction by SDF-1, whereas that of naive cells cannot, despite a similar level of the chemokine receptor CXCR4 present on both cells. We further demonstrate that this difference in the cortical actin contributes to their differential susceptibility to HIV-1; resting memory but not naive T cells are highly responsive to HIV-mediated actin dynamics that promote higher levels of viral entry and early DNA synthesis in resting memory CD4 T cells. Furthermore, transient induction of actin dynamics in resting naive T cells rescues HIV latent infection following CD3/CD28 stimulation. These results suggest a key role of chemotactic actin activity in facilitating HIV-1 latent infection of these T cell subsets.     

HIV envelope-CXCR4 signaling activates cofilin to overcome cortical actin restriction in resting CD4 T cells

Binding of the HIV envelope to the chemokine coreceptors triggers membrane fusion and signal transduction. The fusion process has been well characterized, yet the role of coreceptor signaling remains elusive. Here, we describe a critical function of the chemokine coreceptor signaling in facilitating HIV infection of resting CD4 T cells. We find that static cortical actin in resting T cells represents a restriction and that HIV utilizes the Galphai-dependent signaling from the chemokine coreceptor CXCR4 to activate a cellular actin-depolymerizing factor, cofilin, to overcome this restriction. HIV envelope-mediated cofilin activation and actin dynamics are important for a postentry process that leads to viral nuclear localization. Inhibition of HIV-mediated actin rearrangement markedly diminishes viral latent infection of resting T cells. Conversely, induction of active cofilin greatly facilitates it. These findings shed light on viral exploitation of cellular machinery in resting T cells, where chemokine receptor signaling becomes obligatory.     

Pelargonium wonchiense (Geraniaceae): a new species from Ethiopia

Pelargonium wonchiense is described as new from Ethiopia. It is an annual species with minute flowers, and falls in the section Peristera of which the centre of diversity lies in the south-western Cape Province of South Africa.     

Tubers from potato lines expressing a tomato Kunitz protease inhibitor are substantially equivalent to parental and transgenic controls

Recombinant protease inhibitors represent useful tools for the development of insect‐resistant transgenic crops, but questions have been raised in recent years about the impact of these proteins on endogenous proteases and chemical composition of derived food products. In this study, we performed a detailed compositional analysis of tubers from potato lines expressing the broad‐spectrum inhibitor of Ser and Asp proteases, tomato cathepsin D inhibitor (SlCDI), to detect possible unintended effects on tuber composition. A compositional analysis of key nutrients and toxic chemicals was carried out with tubers of SlCDI‐expressing and control (comparator) lines, followed by a two‐dimensional gel electrophoresis (2‐DE) proteomic profiling of total and allergenic proteins to detect eventual effects at the proteome level. No significant differences were observed among control and SlCDI‐expressing lines for most chemicals assayed, in line with the very low abundance of SlCDI in tubers. Likewise, proteins detected after 2‐DE showed no quantitative variation among the lines, except for a few proteins in some control and test lines, independent of slcdi transgene expression. Components of the patatin storage protein complex and Kunitz protease inhibitors immunodetected after 2‐DE showed unaltered deposition patterns in SlCDI‐expressing lines, clearly suggesting a null impact of slcdi on the intrinsic allergenic potential of potato tubers. These data suggest, overall, a null impact of slcdi expression on tuber composition and substantial equivalence between comparator and SlCDI‐expressing tubers despite reported effects on leaf protein catabolism. They also illustrate the usefulness of proteomics as a tool to assess the authenticity of foods derived from novel‐generation transgenic plants.     

Phylogeny ofEncephalartos: Some eastern cape species

A group of eight species ofEncephalartos, comprisingE. altensteinii, E. arenarius, E. horridus,E. latifrons, E. lehmannii, E. longifolius, E. princeps, andE. trispinosus, from the Eastern Cape Province of South Africa, was studied by analysis of iso-enzymes, ribosome DNA, and ITS 1 and 2 genes. The reason for this investigation was that the morphology of the vegetative and reproductive parts, though very distinctive in this geographical region, do not correlate, and it was hoped that molecular data would elucidate evolutionary relationships. The three sets of molecular data were found to agree to a remarkable degree. It was concluded that the vegetative morphology was misleading but that the cone characteristics agree with molecular data and provide insight into the interrelationships of these species. Thus,E. princeps was concluded to be relatively remotely related to the vegetatively similarE. lehmannii, andE. arenarius is not at all close toE. latifrons even though the two species are easy to confuse when not in cone.     

The Correct Author Citation for Cycas hongheensis and C. parvula (Cycadaceae)

The names Cycas hongheensis and C. parvula were not validly published in 1994 when they were first proposed, but were validated in 1996 by a different author.