T cell vaccination induces T cell receptor Vbeta-specific Qa-1-restricted regulatory CD8(+) T cells

Vaccination of mice with activated autoantigen-reactive CD4(+) T cells (T cell vaccination, TCV) has been shown to induce protection from the subsequent induction of a variety of experimental autoimmune diseases, including experimental allergic encephalomyelitis (EAE). Although the mechanisms involved in TCV-mediated protection are not completely known, there is some evidence that TCV induces CD8(+) regulatory T cells that are specific for pathogenic CD4(+) T cells. Previously, we demonstrated that, after superantigen administration in vivo, CD8(+) T cells emerge that preferentially lyse and regulate activated autologous CD4(+) T cells in a T cell receptor (TCR) Vbeta-specific manner. This TCR Vbeta-specific regulation is not observed in beta2-microglobulin-deficient mice and is inhibited, in vitro, by antibody to Qa-1. We now show that similar Vbeta8-specific Qa-1-restricted CD8(+) T cells are also induced by TCV with activated CD4(+) Vbeta8(+) T cells. These CD8(+) T cells specifically lyse murine or human transfectants coexpressing Qa-1 and murine TCR Vbeta8. Further, CD8(+) T cell hybridoma clones generated from B10.PL mice vaccinated with a myelin basic protein-specific CD4(+)Vbeta8(+) T cell clone specifically recognize other CD4(+) T cells and T cell tumors that express Vbeta8 and the syngeneic Qa-1(a) but not the allogeneic Qa-1(b) molecule. Thus, Vbeta-specific Qa-1-restricted CD8(+) T cells are induced by activated CD4(+) T cells. We suggest that these CD8(+) T cells may function to specifically regulate activated CD4(+) T cells during immune responses.     

Testing the degree of cross-sectional and longitudinal dependence between two discrete dynamic processes.

Developmental research often involves studying change across 2 or more processes or constructs simultaneously. A natural question in this work is whether change in these 2 processes is related or independent. Associative latent transition analysis (ALTA) was designed to test hypotheses about the degree to which change in 2 discrete latent variables is related. The ALTA model is a type of latent class model, which is a categorical latent variable model based on categorical indicators. In the ALTA approach, level and change on 1 variable is predicted by level and change in another. Two types of hypotheses are discussed: (a) broad hypotheses of dependence between the 2 discrete latent variables and (b) targeted hypotheses comparing specific patterns of change between levels of the discrete variables. Both types of hypotheses are tested via nested model comparisons. Analyses of relations between psychological state and substance use illustrate the model. Recent psychological state and recent substance use were found to be associated cross-sectionally and longitudinally, implying that change in recent substance use was related to change in recent psychological state. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multiplex polymerase chain reaction assay for the differential detection of trichothecene- and fumonisin-producing species of Fusarium in cornmeal

The genus Fusarium comprises a diverse group of fungi including several species that produce mycotoxins in food commodities. In this study, a multiplex polymerase chain reaction (PCR) assay was developed for the group-specific detection of fumonisin-producing and trichothecene-producing species of Fusarium. Primers for genus-level recognition of Fusarium spp. were designed from the internal transcribed spacer regions (ITS1 and ITS2) of rDNA. Primers for group-specific detection were designed from the TRI6 gene involved in trichothecene biosynthesis and the FUM5 gene involved in fumonisin biosynthesis. Primer specificity was determined by testing for cross-reactivity against purified genomic DNA from 43 fungal species representing 14 genera, including 9 Aspergillus spp., 9 Fusarium spp., and 10 Penicillium spp. With purified genomic DNA as a template, genus-specific recognition was observed at 10 pg per reaction; group-specific recognition occurred at 100 pg of template per reaction for the trichothecene producer Fusarium graminearum and at 1 ng of template per reaction for the fumonisin producer Fusarium verticillioides. For the application of the PCR assay, a protocol was developed to isolate fungal DNA from cornmeal. The detection of F. graminearum and its differentiation from F. verticillioides were accomplished prior to visible fungal growth at <10(5) CFU/g of cornmeal. This level of detection is comparable to those of other methods such as enzyme-linked immunosorbent assay, and the assay described here can be used in the food industry's effort to monitor quality and safety.     

Green fluorescent protein as a reporter to monitor gene expression and food colonization by Aspergillus flavus

Transformants of Aspergillus flavus containing the Aequorea victoria gfp gene fused to a viral promoter or the promoter region and 483 bp of the coding region of A. flavus aflR expressed green fluorescence detectable without a microscope or filters. Expression of green fluorescent protein fluorescence was correlated with resistance to aflatoxin accumulation in five corn genotypes inoculated with these transformants.     

Neurological deterioration following head injury: the eyes had it

We present a semiclassical treatment for the inclusion of kinetic energy-dependent variations in the moment of inertia for certain molecules exhibiting internal rotational motion. The model is applied to trifluoroacetyl bromide and the resulting dynamically modified transition energies yield an improved spectral deviation in contrast to the rigid model. Copyright 1998 Academic Press.     

Cross-reactivity in HIV-infected patients switched from trimethoprim-sulfamethoxazole to dapsone

STUDY OBJECTIVE: To evaluate the cross-reactivity of dapsone after a documented hypersensitivity reaction to trimethoprim-sulfamethoxazole (TMP-SMX) during prophylaxis for Pneumocystis carinii pneumonia. DESIGN: Retrospective, chart review, cohort study. SETTING: Two university-affiliated teaching hospitals. PATIENTS: Sixty patients infected with the human immunodeficiency virus. MEASUREMENTS AND MAIN RESULTS: Thirteen patients (21.7%) had cross-reactivity to dapsone after the reaction to TMP-SMX. No significant risk factors for this response were identified. Most reactions were of mild or moderate severity and rated as possibly or probably caused by one of the agents. Of the 13 patients, 4 (30.8%) continued therapy. CONCLUSIONS: Although cross-reactivity can occur, dapsone may be considered in patients with mild hypersensitivity reactions to TMP-SMX.     

Do alternative (acupuncture, herbalism, homeopathy etc) have a role in your practice?

Tension pneumothorax in a large man was inadequately drained by needle thoracocentesis with a 4.5 cm cannula. Unsuccessful needle thoracocentesis of a clinical tension pneumothorax in a large patient should be followed immediately by chest drain insertion, without local anaesthetic, as dictated by clinical urgency. If the clinical situation is still not improved other diagnoses should be considered.     

Simultaneous detection of X- and Y-bearing human sperm by double fluorescence in situ hybridization

Double fluorescence in situ hybridization (FISH) was used to detect sex chromosomes in decondensed human sperm nuclei. Biotinylated X chromosome specific (TRX) and digoxigenin-labeled Y chromosome specific (HRY) probes were simultaneously hybridized to sperm preparations from 12 normal healthy donors. After the hybridization, the probes were detected immunocytochemically, using two different and independent affinity systems. Ninety-six percent of the 12,636 sperm showed fluorescent labeling, of which 47.4% were haploid X and 46.8% were haploid Y. A frequency of 0.46% of XX-bearing sperm (0.28% disomic, 0.18% diploid) and 0.38% YY-bearing sperm (0.21% disomic, 0.17% diploid) was found. The overall proportions of X- and Y-bearing sperm in the ejaculates were 47.9% and 47.2%, respectively, which was not significantly different from the expected 50:50 ratio. In addition 0.21% of cells appeared to be haploid XY-bearing sperm, 0.62% were diploid XY-bearing cells, and 0.05% of cells were considered to be tetraploid cells. The application of double FISH to human sperm using X-chromosome and Y-chromosome probes has allowed a more accurate assessment of the sex chromosal complements in sperm than single FISH method and quinacrine staining for Y-bodies.     

Maturation of Qa-1b class I molecules requires beta 2-microglobulin but is TAP independent

Two conformationally distinct and stable forms of Qa-1b, one strongly associated with beta 2-microglobulin (beta 2m) and the other associated with a novel molecule, gp44, were observed during immunochemical studies on the expression of Qa-1b molecules in mouse spleen cells. Both forms are efficiently processed and expressed at the cell surface. However, a large proportion of Qa-1b was found to be disulfide linked to gp44 without any detectable beta 2m. In TAP1-deficient mice, both forms undergo carbohydrate processing and are expressed on the cell surface, suggesting that they may traffic using a pathway not requiring a TAP association step. Consistent with this, size exclusion chromatography of newly synthesized class I molecules shows that high molecular mass complexes containing H-2Kk do not contain Qa-1b. Although Qa-1b can be stably expressed without beta 2m, there was no maturation of either form in cells from beta 2m-deficient mice where heavy chains were rapidly degraded. These results suggest that Qa-1b, like most other class I molecules, requires beta 2m for an initial folding step. However, beta 2m is not essential for subsequent processing of Qa-1b molecules.