Individual- and area-level influence on suicide risk: a multilevel longitudinal study of Swedish schoolchildren.

BACKGROUND: Characteristics related to the areas where people live have been associated with suicide risk, although these might reflect aggregation into these communities of individuals with mental health or social problems. No studies have examined whether area characteristics during childhood are associated with subsequent suicide, or whether risk associated with individual characteristics varies according to childhood neighbourhood context. METHOD: We conducted a longitudinal study of 204,323 individuals born in Sweden in 1972 and 1977 with childhood data linked to suicide (n = 314; 0.15%) up to age 26-31 years. Multilevel modelling was used to examine: (i) whether school-, municipality- or county-level characteristics during childhood are associated with later suicide, independently of individual effects, and (ii) whether associations between individual characteristics and suicide vary according to school context (reflecting both peer group and neighbourhood effects). RESULTS: Associations between suicide and most contextual measures, except for school-level gender composition, were explained by individual characteristics. There was some evidence of cross-level effects of individual- and school-level markers of ethnicity and deprivation on suicide risk, with qualitative interaction patterns. For example, having foreign-born parents increased the risk for individuals raised in areas where they were in a relative minority, but protected against suicide in areas where larger proportions of the population had foreign-born parents. CONCLUSIONS: Characteristics that define individuals as being different from most people in their local environment as they grow up may increase suicide risk. If robustly replicated, these findings have potentially important implications for understanding the aetiology of suicide and informing social policy.

Performance of the Abbott RealTime CT/NG for detection of Chlamydia trachomatis and Neisseria gonorrhoeae.

A multicenter clinical study was conducted to evaluate the performance characteristics of the Abbott RealTime CT/NG assay, a multiplex real-time PCR assay, for simultaneous detection of Chlamydia trachomatis and Neisseria gonorrhoeae. The specimens were collected from a total of 3,832 male and female subjects at 16 geographically diverse sites. Specimens included male and female urine samples, male urethral swabs, female endocervical swabs, and self-collected and clinician-collected vaginal swabs. Specimens were tested with the automated Abbott RealTime CT/NG assay, Aptima Combo 2 assay (Gen-Probe), ProbeTec ET CT/GC assay (Becton Dickinson), and culture for N. gonorrhoeae. The Aptima Combo 2 assay, the ProbeTec assay, and the N. gonorrhoeae culture were used as the reference assays. For each subject, a patient infected status (PIS) was determined based on the combined results from the reference assays. The overall prevalence in female subjects was 8.9% for C. trachomatis and 3.8% for N. gonorrhoeae. The overall male prevalence was 18.2% for C. trachomatis and 16.7% for N. gonorrhoeae. The overall sensitivity and specificity of the Abbott RealTime CT/NG assay were 92.4% and 99.2% for C. trachomatis and 96.9% and 99.7% for N. gonorrhoeae, respectively. In comparison, the sensitivity and specificity, respectively, for the Aptima Combo 2 assay were 94.5% and 99.0% for C. trachomatis and 96.1% and 99.5% for N. gonorrhoeae, and those for the ProbeTec ET assay were 90.3% and 99.5% for C. trachomatis and 92.0% and 97.3% for N. gonorrhoeae in this study. The Abbott RealTime CT/NG assay offers C. trachomatis and N. gonorrhoeae dual detection with high sensitivity and specificity. The automated assay provides a useful alternative nucleic acid amplification assay for clinical laboratories and clinicians.

Prevalence of and risk factors for HIV infection in blood donors and various population subgroups in Ethiopia.

The aim was to determine the prevalence of HIV infection and risk factors for HIV infection in various population subgroups in Ethiopia. Serum panels from blood donors (n = 2610), from various population subgroups in Ethiopia were tested for anti-HIV-1/2 by ELISA. All ELISA repeatedly reactive samples were subjected for confirmation by immunoblot (IB) and anti-HIV-1 and anti-HIV-2 specific ELISAs. 155/2610 (5.9%) blood donors were HIV-1 infected. Of pregnant women, 84/797 (10.5%) were HIV-1 infected, and 1/797 (0.1%) was HIV-2 infected. 1/240 (0.4%) individuals from the rural population were HIV-1 infected. 198/480 (41.3%) female attendees, and 106/419 (25.3%) male attendees at sexual transmitted disease (STD) clinics were HIV-1 infected. One (0.2%) male, and 2 (0.4%) female STD patients were infected with both HIV-1 and HIV-2. It was concluded that the prevalence of HIV-1 infection varied from 0.4% among urban residents to 25.3-41.3% among STD attendees. There is a low prevalence of HIV-2 present in Ethiopian subjects. Risky sexual behaviour is significantly associated with HIV-infection in Ethiopia.

A new ultrasensitive assay for quantitation of HIV-1 RNA in plasma.

Nucleic acid-based diagnostic assays for the quantitation of plasma HIV-1 RNA levels are used to monitor disease progression and the response of patients to antiretroviral drug therapy. The LCx HIV RNA Quantitative Assay (Abbott Laboratories, North Chicago, IL) is an assay for the quantitation of HIV type 1 RNA in plasma that uses competitive reverse transcription PCR (RT-PCR) followed by Microparticle Enzyme Immunoassay, and includes an internal control for inhibition and RNA recovery, that is taken through the entire sample preparation procedure. The performance of the assay was assessed for 1 and 0.2 ml sample volumes. For a 1 ml sample volume, the lower limit of detection was found to be 50 copies/ml with a linear range from 50 to 1 million copies/ml. For a 0.2 ml sample volume, the lower limit of detection was found to be 178 copies/ml with a linear range from 178 to 5 million copies/ml. The assay is able to detect and quantitate HIV subtypes A-G and group O. LCx HIV RNA assay quantitation results are highly correlated to the standard and ultrasensitive Amplicor HIV-1 Monitor assay (Roche Molecular Systems) quantitation results. Assay performance is consistent with the use of this test for routine quantitation of HIV-1 RNA in plasma.

Method for reduction of inhibition in a Mycobacterium tuberculosis-specific ligase chain reaction DNA amplification assay.

The present study describes the identification of inhibitors of a Mycobacterium tuberculosis-specific gap ligase chain reaction (LCR) DNA amplification assay as well as a method for their removal. A major contributor to inhibition was deduced to be a calcium phosphate precipitate, CaHPO4. The precipitate forms during N-acetyl-L-cysteine-sodium hydroxide (NALC-NaOH) decontamination, digestion, and concentration of respiratory specimens. The solubility product of CaHPO4 precipitate at pH 7.8, the pH at which gap LCR is optimized, indicates that the precipitate releases an amount of phosphate ions sufficient to inhibit amplification. A method for removal of the precipitate was identified. The precipitate is dissociated by exposing it to a mildly acidic (pH 4.1) buffer during the first of two centrifugation steps; the inhibitory phosphate ions are removed by the centrifugation steps. When 100 NALC-NaOH respiratory sediments were tested by gap LCR, none of the sediments were inhibitory when the acidic buffer was used while 24 samples were inhibitory when TE buffer, pH 7.8, was used. In another study, when the acidic buffer wash was applied to 1,440 NALC-NaOH respiratory sediments, only 10 sediments were found to be inhibitory. None of the inhibited sediments were culture positive for M. tuberculosis. This work demonstrates that when inhibition mechanisms are identified, relatively simple protocols can be used to obtain low inhibition rates and to allow the use of larger volume equivalents in amplification reactions.

Analytic performance and contamination control methods of a ligase chain reaction DNA amplification assay for detection of Chlamydia trachomatis in urogenital specimens.

A ligase chain reaction (LCR) DNA amplification assay that targeted the cryptic plasmid of Chlamydia trachomatis was developed to detect C. trachomatis urogenital tract infection. The objectives of this study were to determine the cutoff and analytic performance of the LCR assay and to characterize the effectiveness of its postdetection contamination control method. The assay's cutoff was determined after receiver-operator characteristic (ROC) analysis of 4660 clinical data points. The assay detected one infectious unit per reaction of each of the 15 C. trachomatis serovars and did not cross-react with 13 Chlamydia pneumoniae strains, 13 Chlamydia psittaci strains, and 87 other bacteria, fungi, parasites, or viruses. In addition, the assay did not detect 77 processed urine specimens collected from patients with urinary tract infections caused by yeast or bacteria other than C. trachomatis. The assay was sufficiently precise to detect consistently two infectious units of C. trachomatis per reaction. False-positive assay results attributable to contamination with amplified product were minimized by the use of standard procedures as well as by a postdetection chemical inactivation method that could reduce the amount of amplified LCR product by a factor of > or = 10(7).

Diagnosis of Chlamydia trachomatis genitourinary infection in women by ligase chain reaction assay of urine.

Genitourinary infection with Chlamydia trachomatis is a common and potentially serious sexually transmitted disease. Diagnosis of C trachomatis infection in women typically relies on culture of endocervical swabs, an invasive and expensive procedure. The ligase chain reaction (LCR) is an in-vitro nucleic acid amplification technique that exponentially amplifies selected DNA sequences. We have compared an LCR-based assay to detect C trachomatis plasmid DNA in first void urine with culture of endocervical swabs for matched specimens from 1937 women from four geographic regions. Discordant specimen pairs were further tested by direct fluorescent antibody staining for elementary bodies and an alternative LCR assay based on the chlamydial outer membrane protein gene. An "expanded gold standard" was defined to include all culture-positive as well as culture-negative, confirmed LCR-positive women. The sensitivity and specificity of the LCR assay with first void urine samples compared with the expanded gold standard were 93.8% and 99.9%, respectively; the corresponding values for culture were 65.0% and 100%, respectively. Thus, an automated LCR assay of readily obtained urine samples showed a detection rate for infected women almost 30% greater than that of endocervical swab culture. The LCR assay was highly effective for the detection of C trachomatis in urine from women with or without signs or symptoms of chlamydial genitourinary tract infection.

Complete nucleotide sequence of HTLV-II isolate NRA: comparison of envelope sequence variation of HTLV-II isolates from U.S. blood donors and U.S. and Italian i.v. drug users.

The entire nucleotide sequence of human T-cell lymphotropic virus type II (HTLV-II) from a previously described isolate of patient NRA (HTLV-IINRA) was determined. Clones encoding the 5' LTR and gag, pol, env and tax/rex open reading frames were subcloned and sequenced on both strands. The provirus consisted of 8957 nucleotides and showed 95.2% homology with the HTLV-IIMo prototype at the nucleotide level. Less than 5% amino acid variation between HTLV-IINRA and HTLV-IIMo was observed for coding regions. Although isolate HTLV-IINRA had an additional 25 amino acids at the 3' end of tax/rex, this region was 96% homologous with the 5' end of HTLV-IIMo 3' LTR. To further investigate HTLV-II variability, a portion of the env gp46 gene derived from 9 HTLV-II infected persons was amplified by polymerase chain reaction and sequenced. Sequence was obtained for 320 nucleotides corresponding to HTLV-IIMo positions 5291 to 5610. Isolates similar to the HTLV-IIMo and HTLV-IINRA prototypes were identified, and sequences were highly conserved.

The prevalence of antibody to HTLV-I/II in United States plasma donors and in United States and French hemophiliacs.

Antibody to HTLV-I/II was detected in 19 (0.3%) of 6286 plasma donors from five regions of the United States (US). This seroprevalence rate is approximately 10 times that in whole blood donors. The regional distribution of infection was as follows: Southwest, 0.68 percent; Southeast, 0.45 percent; Midwest, 0.28 percent; Northwest, 0.1 percent; and Northeast, 0.0 percent. Rates of HTLV-I/II infection in blacks (0.74%) and Hispanics (0.66%) were higher (both, p less than 0.001) than those in whites (0.08%). All 19 infected units were donated by subjects aged 30 or older, even though 52.9 percent of the donations came from persons less than 30 years old. Equal rates of HTLV-I/II infection were found in men (0.31%) and women (0.29%). No HTLV-I/II antibody was detected in 154 French and 25 US hemophiliacs who were transfused regularly with noninactivated plasma or its derivatives. This suggests that the transfusion of HTLV-I/II-seropositive plasma products does not transmit the viral infection.

Rhinovirus detection using probes from the 5' and 3' end of the genome.

This study investigated the abilities of cDNA probes from the 5' and 3' ends of the genome of human rhinoviruses (HRV-) 14, 9, and 1B to detect RNA from 59 rhinovirus serotypes. The results show that probes from the 5' end of the genomes of HRV-14, 9, and 1 B detected a large number of serotypes but the detection rate was variable and depended on the degree of homology with the particular probe. In contrast, all the 3' end probes were specific for the homologous virus. However, a long HRV-9 probe detected a large number of serotypes. It was concluded that such cDNA probes would not detect all serotypes with equal efficiency. Synthetic oligonucleotides corresponding to short but highly conserved regions in the 5' non coding region may overcome this problem.

Simultaneous in situ carcinoma of the cervix, vulva and perineum after immunosuppressive therapy for renal transplantation.

A 31-year-old woman developed multiple synchronous in situ carcinomas of the cervix uteri, vulva and perineal skin, six years after successful renal transplantation for chronic renal failure due to chronic pyelonephritis. During this time she had been continuously treated with immunosuppressive drugs (azathioprine and prednisolone). The lesions were treated by local excision and there was no evidence of recurrence nearly two years after the primary treatment. The case history is compared to others recently described and highlights the risk of epithelial as well as lymphomatous malignancies in renal transplant recipients.

Aplasia of the first and second branchial arches.

This case report of an otocephalic monster gave the opportunity to study severe orofacial anomalies with a view to clarifying the present position in regard to the so-called first and second arch syndrome. Finding the causal mechanism of this syndrome will eventually lead to prevention and, it is hoped, eradication of this syndrome.