Chlamydia and gonorrhea screening using urine-based nucleic acid amplification testing among males entering New York City jails: a pilot study.

This article describes a pilot screening program to detect Chlamydia trachomatis (Ct) and Neisseria gonorrhoeae (Ng) sexually transmitted infections (STIs) in adolescent and adult males newly incarcerated in New York City jails using urine-based nucleic acid amplification technology (NAAT). Between December 8 and 22, 2003, 2,417 males were tested; 162 (6.7%) were found positive for Ct and/or Ng STIs, with 138 (86.8%) exhibiting no STI signs or symptoms and 102 (63%) treated prior to jail release. Younger age, positive urine leukocyte esterase test, and ≥11 recent sex partners were predictors of STI. Urine-based screening and treatment was feasible in this setting and identified STI that would otherwise have been undetected. Jails may thus be important venues for targeted male STI screening.

Impaired glutamate transport and glutamate-glutamine cycling: downstream effects of the Huntington mutation.

The pathogenesis of Huntington's disease is still not completely understood. Several lines of evidence from toxic/non-transgenic animal models of Huntington's disease suggest that excitotoxic mechanisms may contribute to the pathological phenotype. Evidence from transgenic animal models of Huntington's disease, however, is sparse. To explore potential alterations in brain glutamate handling we studied transgenic mice expressing an N-terminal fragment of mutant huntingtin (R6/2). Intracerebral microdialysis in freely moving mice showed similar extracellular glutamate levels in R6/2 and littermate controls. However, partial inhibition of glutamate transport by L-trans-pyrrolidine-2,4-dicarboxylate (4 mM) disclosed an age-dependent increase in extracellular glutamate levels in R6/2 mice compared with controls, consistent with a reduction of functional glutamate transport capacity. Biochemical studies demonstrated an age-dependent downregulation of the glial glutamate transporter GLT-1 mRNA and protein, resulting in a progressive reduction of transporter function. Glutamate transporters other than GLT-1 were unchanged. In addition, increased extracellular glutamine levels and alterations to glutamine synthetase immunoreactivity suggested a perturbation of the glutamate-glutamine cycle. These findings demonstrate that the Huntington's disease mutation results in a progressively deranged glutamate handling in the brain, beginning before the onset of symptoms in mice. They also provide evidence for a contribution of excitotoxicity to the pathophysiology of Huntington's disease, and thus Huntington's disease may be added to the growing list of neurodegenerative disorders associated with compromised glutamate transport capacity.

Inhibition of polyglutamine aggregation in R6/2 HD brain slices-complex dose-response profiles.

Huntington's disease (HD) is a late onset neurodegenerative disorder caused by a CAG/polyglutamine (polyQ) repeat expansion. PolyQ aggregates can be detected in the nuclei and processes of neurons in HD patients and mouse models prior to the onset of symptoms. The misfolding and aggregation pathway is an important therapeutic target. To better test the efficacy of aggregation inhibitors, we have developed an organotypic slice culture system. We show here that the formation of polyQ aggregates in hippocampal slices established from the R6/2 mouse follows the same prescribed sequence as occurs in vivo. Using this assay, we show that Congo red and chrysamine G can modulate aggregate formation, but show complex dose-response curves. Oral administration of creatine has been shown to delay the onset of all aspects of the phenotype and neuropathology in R6/2 mice. We show here that creatine can similarly inhibit aggregate formation in the slice culture assay.

Centrosome disorganization in fibroblast cultures derived from R6/2 Huntington's disease (HD) transgenic mice and HD patients.

Huntington's disease (HD) is a progressive neurological disorder caused by a CAG/polyglutamine repeat expansion. We have previously generated the R6/2 mouse model that expresses exon 1 of the human HD gene containing CAG repeats in excess of 150. These mice develop a progressive neurological phenotype with a rapid onset and progression. We show here that it is impossible to establish fibroblast lines from these mice at 12 weeks of age, whilst this can be achieved without difficulty at 6 and 9 weeks. Cultures derived from mice at 12 weeks contained a high frequency of dysmorphic cells, including cells with an aberrant nuclear morphology and a high frequency of micronuclei and large vacuoles. All of these features were also present in a line derived from a juvenile HD patient. Fibroblast lines derived from R6/2 mice and from HD patients were found to have a high frequency of multiple centrosomes which could account for all of the observed phenotypes including a reduced mitotic index, high frequency of aneuploidy and persistence of the midbody. We were unable to detect large insoluble polyglutamine aggregates in either the mouse or human lines. We have identified a novel progressive HD pathology that occurs in cells of non-central nervous system origin. An investigation of the pathological consequences of the HD mutation in these cells will provide insight into cellular basis of the disease.

Impaired glutamate uptake in the R6 Huntington's disease transgenic mice.

Huntington's disease (HD) is a late-onset neurodegenerative disease for which the mutation is CAG/polyglutamine repeat expansion. The R6 mouse lines expressing the HD mutation develop a movement disorder that is preceded by the formation of neuronal polyglutamine aggregates. The phenotype is likely caused by a widespread neuronal dysfunction, whereas neuronal cell death occurs late and is very selective. We show that a decreased mRNA level of the major astroglial glutamate transporter (GLT1) in the striatum and cortex of these mice is accompanied by a concomitant decrease in glutamate uptake. In contrast, the expression of the glutamate transporters, GLAST and EAAC1, remain unchanged. The mRNA level of the astroglial enzyme glutamine synthetase is also decreased. These changes in expression occur prior to any evidence of neurodegeneration and suggest that a defect in astrocytic glutamate uptake may contribute to the phenotype and neuronal cell death in HD.

Recombination signal sequences restrict chromosomal V(D)J recombination beyond the 12/23 rule.

The genes encoding the variable regions of lymphocyte antigen receptors are assembled from variable (V), diversity (D) and joining (J) gene segments. V(D)J recombination is initiated by the recombinase activating gene (RAG)-1 and -2 proteins, which introduce DNA double-strand breaks between the V, D and J segments and their flanking recombination signal sequences (RSSs). Generally expressed DNA repair proteins then carry out the joining reaction. The conserved heptamer and nonamer sequences of the RSSs are separated by non-conserved spacers of 12 or 23 base pairs (forming 12-RSSs and 23-RSSs). The 12/23 rule, which is mediated at the level of RAG-1/2 recognition and cutting, specifies that V(D)J recombination occurs only between a gene segment flanked by a 12-RSS and one flanked by a 23-RSS. Vbeta segments are appended to DJbeta rearrangements, with little or no direct Vbeta to Jbeta joining, despite 12/23 compatibility of Vbeta 23-RSSs and Jbeta12-RSSs. Here we use embryonic stem cells and mice with a modified T-cell receptor (TCR)beta locus containing only one Dbeta (Dbeta1) gene segment and one Jbeta (Jbeta1) gene cluster to show that the 5' Dbeta1 12-RSS, but not the Jbeta1 12-RSSs, targets rearrangement of a diverse Vbeta repertoire. This targeting is precise and position-independent. This additional restriction on V(D)J recombination has important implications for the regulation of variable region gene assembly and repertoire development.

Mechanisms that direct ordered assembly of T cell receptor beta locus V, D, and J gene segments.

T cell receptor (TCR) beta variable region genes are assembled in progenitor T cells from germ-line Vbeta, Dbeta, and Jbeta segments via an ordered two-step process in which Dbeta to Jbeta rearrangements occur on both alleles before appendage of a Vbeta to a preexisting DJbeta complex. Direct joining of Vbeta segments to nonrearranged Dbeta or Jbeta segments, while compatible with known restrictions on the V(D)J recombination mechanism, are infrequent within the endogenous TCRbeta locus. We have analyzed mechanisms that mediate ordered Vbeta, Dbeta, and Jbeta assembly via an approach in which TCRbeta minilocus recombination substrates were introduced into embryonic stem cells and then analyzed for rearrangement in normal thymocytes by recombinase-activating gene 2-deficient blastocyst complementation. These analyses demonstrated that Vbeta segments are preferentially targeted for rearrangement to Dbeta as opposed to Jbeta segments. In addition, we further demonstrated that Vbeta segments can be appended to nonrearranged endogenous Dbeta segments in which we have eliminated the ability of Dbeta segments to join to Jbeta segments. Our findings are discussed in the context of the mechanisms that regulate the ordered assembly and utilization of V, D, and J segments.

Predictors of screening for breast, cervical, colorectal, and prostatic cancer among community-based primary care practices.

BACKGROUND: As we enter the year 2000, it is worth looking at whether primary care practices are reaching the goals established in Healthy People 2000 for breast, cervical, colorectal, and prostatic cancer screening. The objectives of this study were (1) to determine the current rates of cancer screening; and (2) to determine which factors predict completion of a single screening test, of all tests for each cancer, and of all procedures for age and sex. METHODS: Medical records of 200 eligible patients (100 men and 100 women) from each of 24 community-based primary care practices were abstracted for cancer-screening events. RESULTS: We audited 5125 charts. A Papanicolaou smear was documented for 63.8% of women with an intact cervix within 3 years of the audit.. We found that 46.8% of women had documentation of ever having a discussion of breast self-examination. For breast cancer screening, 41.8% of the women had a clinical breast examination within 1 year, 48.2% aged 40 to 49 years had a mammogram within 2 years, and 38.5% aged 50 years and older had a mammogram within 1 year. Only 29% of women aged 40 to 49 years and 17% of women 50 years and older were current for all breast cancer-screening tests. Among patients 50 years and older, 33% of men and 38% of women had a digital rectal examination within 1 year, 26% of men and 28% of women had a fecal occult blood test within 1 year, and 22% of men and 16.8% of women had a flexible sigmoidoscopy within 5 years. Of all men 28.7% had a prostate-specific antigen test within 1 year. Completion of all tests relevant for age and sex were documented for 8.6% of women aged 40 to 49 years, 3% of women 50 years and older, and 5% of men 50 years and older. The single most significant predictor of documented cancer screening was a health maintenance visit. CONCLUSIONS: This sample of primary care clinicians has not reached the goals set in Healthy People 2000 for cancer screening. Interventions aimed at increasing the percentage of patients who schedule a health maintenance visit could serve to increase cancer screening and help us reach goals set for the year 2010.

The Pallister-Killian syndrome in an African individual.

We report for the first time an individual of Zulu origin with the Pallister-Killian syndrome. Apart from the commonly reported clinical signs, he also had frenula in all four quadrants of the mouth. A broad, short hallux was present. An unusually high level of mosaicism for the isochromosome 12p was found in the lymphocytes.