Plasma homocysteine levels in female patients with eating disorders

OBJECTIVE: To examine plasma homocysteine, vitamin B(12), and folate levels in females with restricting and bingeing/purging eating disorders (EDs). METHOD: Adolescent and adult female patients were compared to appropriate control groups with regard to plasma homocysteine levels. RESULTS: The plasma homocysteine level of the adult ED patients was higher than that of controls for all age groups examined. In adolescents, no significant difference was found comparing ED patients younger than 16 years of age to control data, whereas in the 16-20 year age group, the plasma homocysteine level was significantly higher among the ED group, regardless of the type of ED. Vitamin B(12) and folate levels were within normal limits in all ED groups. CONCLUSION: Elevated plasma homocysteine levels were found in adult and older adolescent female ED patients (but not in younger adolescents) compared to controls. This finding is not related to deficiencies in vitamin B(12) or folate.     

Pretreatment with corticosteroids attenuates the efficacy of colchicine in preventing recurrent pericarditis: a multi-centre all-case analysis.

AIMS: Effective prevention of recurrent pericarditis remains an important yet elusive goal. Corticosteroid therapy often needs to be continued for a prolonged period and causes severe side effects. We performed a multi-centre all-case analysis to investigate the efficacy of colchicine in preventing subsequent relapses of pericarditis, and addressed the hypothesis that pretreatment with corticosteroids may attenuate the beneficial effect of colchicine. METHODS AND RESULTS: One hundred and forty published and unpublished cases of patients treated with colchicine after at least two relapses of pericarditis were aggregated from European centres. Of those, 119 were included in the study group. Only 18% of the patients had relapses under colchicine therapy, and 30% after its discontinuation. There were significantly more relapses among male patients after colchicine treatment (36 vs. 17%, P=0.046), and those with previous corticosteroid treatment (43 vs. 13%, P=0.02). Multivariate logistic regression analysis identified previous corticosteroid therapy (OR 6.68, 95% CI: 1.65-27.02) and male gender (OR 4.20, 95% CI: 1.16-15.21) as independent risk factors for recurrence following colchicine therapy. CONCLUSION: Treatment with colchicine is highly effective in preventing recurrent pericarditis, while pretreatment with corticosteroids exacerbates and extends the course of recurrent pericarditis.     

The caspase-cleaved DAP5 protein supports internal ribosome entry site-mediated translation of death proteins

Apoptosis is characterized by a translation switch from cap-dependent to internal ribosome entry site (IRES)-mediated protein translation. During apoptosis, several members of the eukaryotic initiation factor (eIF)4G family are cleaved specifically by caspases. Here we investigated which of the caspase-cleaved eIF4G family members could support cap-independent translation through IRES elements that retain activity in the dying cell. We focused on two major fragments arising from the cleavage of eIF4GI and death-associated protein 5 (DAP5) proteins (eIF4GI M-FAG/p76 and DAP5/p86, respectively), because they are the only potential candidates to preserve the minimal scaffold function needed to mediate translation. Transfection-based experiments in cell cultures indicated that expression of DAP5/p86 in cells stimulated protein translation from the IRESs of c-Myc, Apaf-1, DAP5, and XIAP. In contrast, these IRESs were refractory to the ectopically expressed eIF4GI M-FAG/p76. Furthermore, our study provides in vivo evidence that the caspase-mediated removal of the C-terminal tail of DAP5/p97 relieves an inhibitory effect on the protein's ability to support cap-independent translation through the DAP5 IRES. Altogether, the data suggest that DAP5 is a caspase-activated translation factor that mediates translation through a repertoire of IRES elements, supporting the translation of apoptosis-related proteins.     

Stop codons affect 5' splice site selection by surveillance of splicing

Pre-mRNA splicing involves recognition of a consensus sequence at the 5' splice site (SS). However, only some of the many potential sites that conform to the consensus are true ones, whereas the majority remain silent and are not normally used for splicing. We noticed that in most cases the utilization of such a latent intronic 5' SS for splicing would introduce an in-frame stop codon into the resultant mRNA. This finding suggested a link between SS selection and maintenance of an ORF within the mRNA. Here we tested this idea by analyzing the splicing of pre-mRNAs in which in-frame stop codons upstream of a latent 5' SS were mutated. We found that splicing with the latent site is indeed activated by such mutations. Our findings predict the existence of a checking mechanism, as a component of the nuclear pre-mRNA splicing machine, to ensure the maintenance of an ORF. This notion is highly important for accurate gene expression, as perturbations that would lead to splicing at these latent sites are expected to introduce in-frame stop codons into the majority of mRNAs.     

High degree of inter-clade cross-reactivity of HIV-1-specific T cell responses at the single peptide level

OBJECTIVES: To determine HIV-1-specific T cell responses in clade B infected individuals recognizing the clade A, B and C consensus sequences in order to assess the degree of inter-clade cross-reactivity of these immune responses at the single epitope level. METHODS: HIV-1-specific T cell responses were assessed cross-sectionally in 27 chronically HIV-1-infected individuals from a population infected mainly with clade B viral strains, using an interferon-gamma Elispot assay with a total of 1230 overlapping peptides spanning the entire amino acid sequence of the clade A, B and C 2001 consensus sequences. RESULTS: No significant difference was observed between the total magnitude or breadth of T cell responses recognizing either the clade A, B or C consensus sequences. However, at the single peptide level, 194 T cell responses were identified that recognized only one of the three different clade-specific peptide variants (A: B: C, 34: 105: 55), 125 T cell responses recognized two of the three peptide variants (AB: AC: BC, 71: 15: 39) and 166 T cell responses (34%) were cross-reactive with all three different peptide variants. Peptides recognized in all three consensus sequence variants had a significantly lower entropy (P < 0.0001) and a significantly higher inter-clade homology (P < 0.0001). CONCLUSIONS: Viral epitopes within regions of low HIV-1 clade B diversity and high inter-clade homology can be recognized in the clade A, B and C variants and indicate a wide degree of cross-isolate and cross-clade recognition by HIV-1-specific T cells. These regions may therefore be of particular relevance for the design of HIV-1 vaccines.     

HIV-1-specific cytotoxicity is preferentially mediated by a subset of CD8(+) T cells producing both interferon-gamma and tumor necrosis factor-alpha

CD8(+) T cells play a crucial role in the control of viral infections by direct elimination of infected cells and secretion of a number of soluble factors. Recent data suggest that HIV-1-specific CD8(+) T cell subsets may differ in their ability to exert these effector functions. Here, we directly compared the cytokine secretion patterns and cytotoxic capacity of HIV-1-specific CD8(+) T cells, using a flow-cytometric cytotoxicity assay based on caspase-3 activation in dying target cells. These experiments revealed considerable intraindividual and interindividual differences among epitope-specific T-cell effector functions: while the frequency of HIV-1-specific CD8(+) T cells secreting interferon-gamma but no tumor necrosis factor-alpha (TNF-alpha) following antigenic stimulation was only weakly correlated to their cytotoxic activity (R = 0.05, P =.57), a subset of CD8(+) T cells secreting both inter-feron-gamma and TNF-alpha was substantially more strongly associated with cytotoxicity (R = 0.67, P <.001). This subset of CD8(+) T cells also exhibited stronger intracellular perforin expression and more pronounced direct ex vivo HIV-1-specific cytoxicity than CD8(+) T cells secreting solely interferon-gamma following sorting of these subpopulations according to their cytokine profile. These results suggest that HIV-1-specific cytotoxicity of CD8(+) T cells is preferentially mediated by a subset of CD8(+) T cells secreting both interferon-gamma and TNF-alpha.