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Abstract Background Duplicated glucocorticoid receptors (GR) are present in most teleost fish. The evolutionary advantage of retaining two GRs is unclear, as no subtype specific functional traits or physiological roles have been defined. To identify factors driving the retention of duplicate GRs in teleosts, the current study examined GRs in representatives of two basal ray-finned fish taxa that emerged either side of the teleost lineage whole genome duplication event (WGD) event, the acipenseriform, Acipenser ruthenus, (pre-WGD) and the osteoglossimorph, Pantodon buchholzi, (post-WGD). Results The study identified a single GR in A. ruthenus (ArGR) and two GRs in P. buchholzi (PbGR1 and PbGR2). Phylogenetic analyses showed that ArGR formed a distinct branch separate from the teleosts GRs. The teleost GR lineage was subdivded into two sublineages, each of which contained one of the two P. buchholzi GRs. ArGR, PbGR1 and PbGR2 all possess the unique 9 amino acid insert between the zinc-fingers of the DNA-binding domain that is present in one of the teleost GR lineages (GR1), but not the other (GR2). A splice variant of PbGR2 produces an isoform that lacked these 9 amino acids (PbGR2b). Cortisol stimulated transactivation activity of ArGR, PbGR2b and PbGR1 in vitro; with PbGR2b and PbGR1, the glucocorticoid 11-deoxycortisol was a more potent agonist than cortisol. The hormone sensitivity of PbGR2b and PbGR1 differed in the transactivation assay, with PbGR2b having lower EC50 values and greater fold induction. Conclusions The difference in transactivation activity sensitivity between duplicated GRs of P. buchholzi suggests potential functional differences between the paralogs emerged early in the teleost lineage. Given the pleiotropic nature of GR function in vertebrates, this finding is in accordance with the hypothesis that duplicated GRs were potentially retained through subfunctionalisation followed by gene sharing. A 9 amino acid insert in the DNA-binding domain emerged in basal ray-finned fish GRs. However, the presence of a PbGR2 splice variant that lacks this insert, as well as the loss of the exon encoding these amino acids in the genes encoding for other teleost GR2 suggests the selection of two receptors with different DNA-binding domain structures in teleosts.

Abstract Background Zinc deficiency is detrimental to organisms, highlighting its role as an essential micronutrient contributing to numerous biological processes. To investigate the underlying molecular events invoked by zinc depletion we performed a temporal analysis of transcriptome changes observed within the zebrafish gill. This tissue represents a model system for studying ion absorption across polarised epithelial cells as it provides a major pathway for fish to acquire zinc directly from water whilst sharing a conserved zinc transporting system with mammals. Results Zebrafish were treated with either zinc-depleted (water = 2.61 μg L-1; diet = 26 mg kg-1) or zinc-adequate (water = 16.3 μg L-1; diet = 233 mg kg-1) conditions for two weeks. Gill samples were collected at five time points and transcriptome changes analysed in quintuplicate using a 16K oligonucleotide array. Of the genes represented the expression of a total of 333 transcripts showed differential regulation by zinc depletion (having a fold-change greater than 1.8 and an adjusted P-value less than 0.1, controlling for a 10% False Discovery Rate). Down-regulation was dominant at most time points and distinct sets of genes were regulated at different stages. Annotation enrichment analysis revealed that 'Developmental Process' was the most significantly overrepresented Biological Process GO term (P = 0.0006), involving 26% of all regulated genes. There was also significant bias for annotations relating to development, cell cycle, cell differentiation, gene regulation, butanoate metabolism, lysine degradation, protein tyrosin phosphatases, nucleobase, nucleoside and nucleotide metabolism, and cellular metabolic processes. Within these groupings genes associated with diabetes, bone/cartilage development, and ionocyte proliferation were especially notable. Network analysis of the temporal expression profile indicated that transcription factors foxl1, wt1, nr5a1, nr6a1, and especially, hnf4a may be key coordinators of the homeostatic response to zinc depletion. Conclusions The study revealed the complex regulatory pathways that allow the organism to subtly respond to the low-zinc condition. Many of the processes affected reflected a fundamental restructuring of the gill epithelium through reactivation of developmental programs leading to stem cell differentiation. The specific regulation of genes known to be involved in development of diabetes provides new molecular links between zinc deficiency and this disease. The present study demonstrates the importance of including the time-dimension in microarray studies.

Abstract Background Dietary zinc supplementation may help to promote growth, boost the immune system, protect against diabetes, and aid recovery from diarrhoea. We exploited the zebrafish (Danio rerio) gill as a unique vertebrate ion transporting epithelium model to study the time-dependent regulatory networks of gene-expression leading to homeostatic control during zinc supplementation. This organ forms a conduit for zinc uptake whilst exhibiting conservation of zinc trafficking components. Results Fish were maintained with either zinc supplemented water (4.0 μM) and diet (2023 mg zinc kg-1) or water and diet containing Zn2+ at 0.25 μM and 233 mg zinc kg-1, respectively. Gill tissues were harvested at five time points (8 hours to 14 days) and transcriptome changes analysed in quintuplicate using a 16 K microarray with results anchored to gill Zn2+ influx and whole body nutrient composition (protein, carbohydrate, lipid, elements). The number of regulated genes increased up to day 7 but declined as the fish acclimated. In total 525 genes were regulated (having a fold-change more than 1.8 fold change and an adjusted P-value less than 0.1 which is controlling a 10% False discovery rate, FDR) by zinc supplementation, but little overlap was observed between genes regulated at successive time-points. Many genes displayed cyclic expression, typical for homeostatic control mechanisms. Annotation enrichment analysis revealed strong overrepresentation of "transcription factors", with specific association evident with "steroid hormone receptors". A suite of genes linked to "development" were also statistically overrepresented. More specifically, early regulation of genes was linked to a few key transcription factors (e.g. Mtf1, Jun, Stat1, Ppara, Gata3) and was followed by hedgehog and bone morphogenic protein signalling. Conclusions The results suggest that zinc supplementation reactivated developmental pathways in the gill and stimulated stem cell differentiation, a response likely reflecting gill remodelling in response to its altered environment. This provides insight to the role of zinc during cell differentiation and illustrates the critical nature of maintaining zinc status. The study also highlights the importance of temporal transcriptomics analysis in order resolve the discrete elements of biological processes, such as zinc acclimation.

Abstract Background The large gene superfamily of ABC (ATP-binding cassette) transporters encodes membrane proteins involved in trafficking processes across biological membranes and further essential cell biological functions. ABC transporters are evolutionary ancient and involved in the biochemical defence against toxicants. We report here a genome-wide survey of ABC proteins of Daphnia pulex, providing for the first time information on ABC proteins in crustacea, a primarily aquatic arthropod subphylum of high ecological and economical importance. Results We identified 64 ABC proteins in the Daphnia genome, which possesses members of all current ABC subfamilies A to H. To unravel phylogenetic relationships, ABC proteins of Daphnia were compared to those from yeast, worm, fruit fly and human. A high conservation of Daphnia of ABC transporters was observed for proteins involved in fundamental cellular processes, including the mitochondrial half transporters of the ABCB subfamily, which function in iron metabolism and transport of Fe/S protein precursors, and the members of subfamilies ABCD, ABCE and ABCF, which have roles in very long chain fatty acid transport, initiation of gene transcription and protein translation, respectively. A number of Daphnia proteins showed one-to-one orthologous relationships to Drosophila ABC proteins including the sulfonyl urea receptor (SUR), the ecdysone transporter ET23, and the eye pigment precursor transporter scarlet. As the fruit fly, Daphnia lacked homologues to the TAP protein, which plays a role in antigene processing, and the cystic fibrosis transmembrane conductance regulator (CFTR), which functions as a chloride channel. Daphnia showed two proteins homologous to MDR (multidrug resistance) P-glycoproteins (ABCB subfamily) and six proteins homologous to MRPs (multidrug resistance-associated proteins) (ABCC subfamily). However, lineage specific gene duplications in the ABCB and ABCC subfamilies complicated the inference of function. A particularly high number of gene duplications were observed in the ABCG and ABCH subfamilies, which have 23 and 15 members, respectively. Conclusion The in silico characterisation of ABC transporters in the Daphnia pulex genome revealed that the complement of ABC transporters is as complex in crustaceans as that other metazoans. Not surprisingly, among currently available genomes, Daphnia ABC transporters most closely resemble those of the fruit fly, another arthropod.

Background: Risk of anal cancer is high in certain populations and screening involves collection of anal swabs for HPV DNA and/or cytology testing. However, barriers exist, such as the need for an intimate examination, and stigma around HIV status, sexual orientation, and sexual practices. Self-collected anal swabs (SCA) are a proposed alternative to clinician-collected swabs (CCA) to overcome these barriers., Methods: Participants were order-randomised to undergo SCA or CCA first, with a second swab taken immediately afterwards. Sample adequacy was assessed for HPV DNA and cytology testing. CCA was used as the gold standard to calculate sensitivity and specificity of SCA for cytology and HPV results. Acceptability of swab collection was assessed following the procedure., Results: There was no significant difference in sample validity for HPV DNA testing between SCA and CCA (p = 0.564). Concordance was >90% for detection of any HR-HPV and HPV16. There was no significant difference in cellular adequacy for cytological testing between SCA and CCA, (p = 0.162). Concordance for cytologic prediction was 88.2% for any cytologic abnormality. Almost half (48.5%) of participants expressed no preference for SCA versus CCA; 15.2% preferred SCA and 35.4% CCA., Conclusions: SCA may be an acceptable and feasible alternative to CCA for detecting HPV and cytological abnormalities in a clinic population., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2025 Dyer et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Finger-stick point-of-care and dried blood spot (DBS) hepatitis C virus (HCV) RNA testing increases testing uptake and linkage to care. This systematic review evaluated the diagnostic accuracy of point-of-care testing and DBS to detect HCV RNA., Methods: Bibliographic databases and conference presentations were searched for eligible studies. Meta-analysis was used to pool estimates., Results: Of 359 articles identified, 43 studies were eligible and included. When comparing the Xpert HCV Viral Load Fingerstick assay to venous blood samples (7 studies with 987 samples), the sensitivity and specificity for HCV RNA detection was 99% (95% confidence interval [CI], 97%-99%) and 99% (95% CI, 94%-100%) and for HCV RNA quantification was 100% (95% CI, 93%-100%) and 100% (95% CI, 94%-100%). The proportion of invalid results following Xpert HCV Viral Load Fingerstick testing was 6% (95% CI, 3%-11%). When comparing DBS to venous blood samples (28 studies with 3988 samples) the sensitivity and specificity for HCV RNA detection was 97% (95% CI, 95%-98%) and 100% (95% CI, 98%-100%) and for HCV RNA quantification was 98% (95% CI, 96%-99%) and 100% (95% CI, 95%-100%)., Conclusions: Excellent diagnostic accuracy was observed across assays for detection of HCV RNA from finger-stick and DBS samples. The proportion of invalid results following Xpert HCV Viral Load Fingerstick testing highlights the importance of operator training and quality assurance programs., Competing Interests: Potential conflicts of interest. J. G. is a consultant/advisor and has received research grants from AbbVie, Cepheid, Gilead, Hologic, Indivior, and Merck; and personal fees from AbbVie, Cepheid, Gilead, and Merck, outside the submitted work. G. D. reports grants from Cepheid, during the conduct of the study; grants, personal fees, and nonfinancial support from Gilead, Abbvie, Merck, Bristol-Myers Squibb, Janssen, and Roche; personal fees from GlaxoSmithKline and Abbott Diagnostics; and grants from Cepheid outside the submitted work. T. A. reports grants and personal fees from Cepheid during the conduct of the study; and grants from Abbott Diagnostics, outside the submitted work. J. F. consults for and owns intellectual property rights in Gilead; and consults for AbbVie. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2022. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: Dried blood spot (DBS) specimens are a useful serosurveillance tool particularly in hard-to-reach populations but their application for detecting SARS-CoV-2 infection is poorly characterised., Objectives: To compare detection of naturally acquired SARS-CoV-2 antibodies in paired DBS and serum specimens using commercially available serological immunoassays., Study Design: Specimens were collected through St Vincent's Hospital observational post COVID-19 cohort study (ADAPT). Laboratory spotted DBS from venepuncture were initially tested on seven assays, a DBS validation completed on three with clinically collected fingerstick DBSs tested on one., Results: Sensitivity for Euroimmun nucleocapsid (NCP) IgG ELISA from laboratory spotted DBS (n=145), Euroimmun spike, IgG ELISA from laboratory spotted DBS (n=161), and Binding Site total antibody ELISA from clinically collected fingerstick DBS (n=391) was 100% (95% CI: 95.8-100%), 100% (95% CI: 95.8-100%) and 92.9% (95% CI: 89.5-95.5%), respectively. Specificity was 66.2% (95% CI: 53.6-77.0%), 96% (95% CI: 88.7-99.1%) and 98.8% (95% CI: 93.3-99.9%), respectively. All three assays' results displayed a strong positive correlation between DBS compared to paired serum., Conclusions: The Binding Site™ spike total antibody and Euroimmun™ spike IgG ELISAs provided good analytical performance, demonstrating that DBS specimens could facilitate specimen collection in the epidemiological surveillance of SARS-CoV-2 infection. This is highly applicable in populations and settings where venepuncture is problematic (including community based regional/remote settings, nursing homes, prisons, and schools)., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors. Published by Elsevier Ltd.)

Background: Simplified diagnostic strategies are needed increase hepatitis C virus (HCV) testing to determine active infection and link people into treatment. Collection methods such as dried blood spots (DBS) have advantages over standard phlebotomy, especially within marginalized populations., Methods: We evaluated the diagnostic performance of the Aptima HCV Quant assay for the quantification and detection of HCV RNA from paired DBS and venepuncture samples. Specimens were collected from participants enrolled in an Australian observational study. We compared HCV RNA detection from DBS against venepuncture samples (gold standard)., Results: One hundred sixty-four participants had paired samples and HCV RNA was detected in 45 (27% [95% confidence interval, 21%-35%]) by the Aptima assay in venepuncture samples. Sensitivity of the Aptima assay for HCV RNA quantification from DBS (≥10 IU/mL in plasma) was 100% and specificity was 100%. Sensitivity for HCV RNA detection from DBS was 95.6% and specificity was 94.1%. A small bias in plasma over DBS was observed with good agreement (R2 = 0.96)., Conclusions: The Aptima HCV Quant assay detects active infection from DBS samples with acceptable diagnostic performance and is clinically comparable to plasma. These data will strengthen the case for the registration of a DBS kit insert claim, enabling future clinical utility., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

The global scale-up of hepatitis C virus (HCV) diagnosis requires simplified and affordable HCV diagnostic pathways. This study evaluated the sensitivity and specificity of the HCV Architect core antigen (HCVcAg) assay for detection of active HCV infection in plasma and capillary whole blood dried blood spots (DBS) compared with HCV RNA testing in plasma (Abbott RealTime HCV Viral Load). Samples were collected from participants in an observational cohort enrolled at three sites in Australia (two-drug treatment and alcohol clinics and one homelessness service). Of 205 participants, 200 had results across all samples and assay types and 186 were included in this analysis (14 participants receiving HCV therapy were excluded). HCV RNA was detected in 29% of participants ([95% CI: 22.6-36.1], 54 of 186). The sensitivity of HCVcAg for detection of active HCV infection in plasma was 98.1% (95% CI: 90-100) and 100% (95% CI: 93-100) when compared to HCV RNA thresholds of ≥12 and ≥1000 IU/mL, respectively. The sensitivity of the HCVcAg assay for detection of active HCV infection in DBS was 90.7% (95% CI: 80-97) and 92.5% (95% CI: 82-98) when compared to HCV RNA thresholds of ≥12 and ≥1000 IU/mL, respectively. The specificity of HCV core antigen for detection of active infection was 100% (95% CI: 97-100) for all samples and RNA thresholds. These data indicate that the detection of HCVcAg is a useful tool for determining active HCV infection; to facilitate enhanced testing, linkage to care and treatment particularly when testing plasma samples are collected by venepuncture., (© 2019 John Wiley & Sons Ltd.)

Two independent mol-ecules of the title solvated complex, [V(C16H14N2O2)O]·CH3OH, also known as [N,N'-bis-(salicyl-idene)ethyl-enedi-amine]-oxidovanadium(IV) or vanadyl salen, crystallize in the asymmetric unit. Each disordered methanol solvent mol-ecule [occupancy ratios 0.678 (4):0.322 (4) and 0.750 (5):0.250 (5)] is linked to a [N,N'-bis-(salicyl-idene)ethyl-enedi-amine]-oxidovanadium(IV) mol-ecule by an O-H⋯O hydrogen bond and to others by C-H⋯O hydrogen bonds. The resulting extended structure consists of a bilayer of mol-ecules parallel to the ab plane. Despite the fact that solvates are common in complexes derived from substituted analogues of the N,N'-bis-(salicyl-idene)ethyl-enedi-amine ligand, the title solvate is the first one of [N,N'-bis-(salicyl-idene)ethyl-enedi-amine]-oxidovanadium(IV) to be structurally characterized. The two vanadyl species have very similar inter-nal geometries, which are best characterized as distorted square-based pyramidal with the vanadium atom displaced from the N2O2 basal plane by 0.5966 (9) Å in the direction of the doubly-bonded oxide ligand.

Background: Concordance in plasma HIV-1 viral load quantification at the lower limit of quantification (LLOQ) is crucial for current commercial assays., Objective: To compare the performance of three commercial viral load assays and carry out a correlation study with the Roche Cobas AmpliPrep/Cobas TaqMan HIV-1 test, the Roche Cobas Amplicor HIV-1 MONITOR test, and the Abbott RealTime HIV-1 assay., Study Design: Assay agreement was analyzed using linear regression and Bland-Altman plots. Concordance near the clinically critical LLOQ was measured by Cohen's kappa statistics. Intra-assay precision was assessed, and assay reproducibility was measured at 50copies/mL across all three platforms., Results: While good overall correlation was observed between the assays (r≥0.93), quantitative differences exceeded 0.5log(10)copies/mL among paired results in 3.7 to 8.3% of specimens. The degree of concordance between the assays near the LLOQ was unsatisfactory, with Cohen's kappa ranging from 0.14 to 0.38. The intra-assay precision of the Abbott RealTime HIV-1 assay ranged from 0.04 to 0.15 (SD log(10)) and 1.34% to 8.37% (CV). Reproducibility at 50copies/mL for RealTime HIV-1, TaqMan, and Amplicor was 10.05, 11.04 and 5.07 (% CV), respectively., Conclusion: Although good correlation was observed between the assays across their linear range, their concordance at the clinically critical LLOQ was poor. The accurate quantification of low-level viremia remains elusive, and the lack of correlation of these assays presents a challenge to the interpretation of such results and in the clinical management of HIV-infected patients., (Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.)

Background: Pharyngeal gonorrhoea is common in homosexual men and may be important in maintaining community prevalence of anogenital infections., Methods: From 2003, all participants in the Health in Men cohort of HIV-negative homosexual men in Sydney were offered annual pharyngeal gonorrhoea screening by BD ProbeTec nucleic acid amplification (NAAT) assay with supplementary porA testing. Participants self-reported diagnoses of pharyngeal gonorrhoea made elsewhere between interviews. Detailed sexual behavioural data were collected 6-monthly., Results: Among 1427 participants enrolled, 65 study-visit-diagnosed pharyngeal gonorrhoea infections were identified (incidence 1.51 per 100 person-years, 95% CI 1.19 to 1.93) of which seven infections were identified on baseline testing (prevalence 0.57%, 95% CI 0.23 to 1.17%). Almost 85% of study-visit-diagnosed pharyngeal infections occurred without concurrent anogenital gonorrhoea. The combined incidence of study-visit-diagnosed and self-reported pharyngeal gonorrhoea (n=193) was 4.45 per 100 person-years (95% CI 3.86 to 5.12). On multivariate analysis, incident infection was associated with younger age (p-trend=0.001), higher number of male partners (p-trend=0.002) and reported contact with gonorrhoea (p<0.001). Insertive oro-anal sex ('rimming') was the only sexual behaviour independently associated with incident pharyngeal gonorrhoea (p-trend=0.044)., Conclusions: The majority of pharyngeal gonorrhoea occurred without evidence of concurrent anogenital infection, and the high incidence-to-prevalence ratio suggests frequent spontaneous resolution of NAAT-detected infection. The association of pharyngeal gonorrhoea with oro-anal sex indicates that a broader range of sexual practices are likely to be involved in transmission of gonorrhoea to the pharynx than previously acknowledged. Screening the pharynx of sexually active homosexual men could play a role in reducing the prevalence of anogenital Neisseria gonorrhoeae.

Background: We examined a range of common bacterial and viral sexually transmitted infections as risk factors for HIV seroconversion in a community-based cohort of HIV-negative homosexual men in Sydney, Australia., Methods: Detailed information about HIV risk behaviors was collected by interview twice yearly. Participants were tested annually for HIV, anal and urethral gonorrhea and chlamydia, herpes simplex virus types 1 and 2, and syphilis. In addition, they reported annual diagnoses of these conditions and of genital and anal warts., Results: Among 1427 enrolled participants, 53 HIV seroconverters were identified, giving an incidence of 0.78 per 100 person-years. After controlling for number of episodes of insertive and receptive nonseroconcordant unprotected anal intercourse, there were independent associations with anal gonorrhea (adjusted hazard ratio = 7.12, 95% confidence interval: 2.05 to 24.79) and anal warts (hazard ratio = 3.63, 95% confidence interval: 1.62 to 8.14)., Conclusions: Anal gonorrhea and anal warts were independently associated with HIV acquisition. The added HIV prevention value of more frequent screening of the anus to allow early detection and treatment of anal sexually transmitted infections in homosexual men should be considered.

Background: Circumcision status was examined as an independent risk factor for sexually transmissible infections (STIs) in the Health in Men cohort of homosexual men in Sydney., Methods: From 2001 through 2004, 1427 initially human immunodeficiency virus (HIV)-negative men were enrolled and followed up until mid-2007. All participants were offered annual STI testing. The history of STIs was collected at baseline, and information on sexual risk behaviors was collected every 6 months. At annual face-to-face visits, participants reported STI diagnoses received during the previous year., Results: Circumcision was not associated with prevalent or incident herpes simplex virus 1, herpes simplex virus 2, or self-reported genital warts. There was also no independent association of circumcision with incident urethral gonorrhea or chlamydia. Being circumcised was associated with a significantly reduced risk of incident (hazard ratio, 0.35 [95% confidence interval, 0.15-0.84]) but not prevalent (odds ratio, 0.71 [95% confidence interval, 0.35-1.44]) syphilis. The association was somewhat stronger among men who reported predominantly insertive unprotected anal intercourse (hazard ratio, 0.10 [95% confidence interval, 0.01-0.82])., Conclusions: These are the first prospective data obtained from homosexual men to assess circumcision status as a risk factor for STIs. Circumcised men were at reduced risk of incident syphilis but no other prevalent or incident STIs. Circumcision is unlikely to have a substantial public health impact in reducing acquisition of most STIs in homosexual men.

Objectives: To determine the prevalence, incidence and risk factors for pharyngeal Chlamydia trachomatis in the community based Health in Men (HIM) cohort of HIV negative homosexual men in Sydney, Australia., Methods: From January 2003, all HIM participants were offered annual screening for pharyngeal chlamydia using BD ProbeTec nucleic acid amplification testing (NAAT). Detailed sexual behavioural data were collected every 6 months, and risk factors for infection and hazard ratios were calculated using Cox regression., Results: Among 1427 participants enrolled, the prevalence of pharyngeal chlamydia on initial testing was 1.06% and the incidence rate was 0.58 per 100 person-years. More than 50% of all infections were identified on baseline testing and 68% of men with pharyngeal infection had no evidence of concurrent anogenital chlamydia. There was no association of pharyngeal chlamydia with sore throat. Infection was significantly associated with increasing frequency of receptive penile-oral sex with ejaculation with casual partners (p = 0.009), although approximately half of infections occurred in participants not reporting this risk behaviour. Neither kissing nor oro-anal practices were associated with infection., Conclusion: The incidence of pharyngeal chlamydia infection in the HIM study was relatively low; however, the relatively high prevalence on baseline testing compared to incidence suggests a long duration of infection. Occasional screening for pharyngeal chlamydia in homosexual men who frequently practise receptive oral sex with ejaculation may be warranted.

The diagnosis of nongenital Neisseria gonorrhoeae infection by the Becton Dickinson ProbeTec ET Chlamydia trachomatis and N. gonorrhoeae Amplified DNA assay had low positive predictive value among an Australian community-based sample of homosexual men. Only 30.4% of oropharyngeal samples and 73.7% of anorectal samples were positive for N. gonorrhoeae by the porA assay. The accuracy of nucleic acid amplification tests in this context is compromised without supplemental testing.

Background/objectives: Higher levels of sexual risk behaviours have been reported in HIV positive than in HIV negative homosexual men. In clinic based studies, higher rates of sexually transmitted infections (STIs) have also been reported. We compared rates of common STIs between HIV positive and HIV negative homosexual men from two ongoing community based cohort studies in Sydney, Australia., Methods: Participants in the two cohorts were recruited using similar community based strategies. They were interviewed face to face annually after enrollment. Comprehensive sexual health screening, including hepatitis A and B, syphilis, gonorrhoea, and chlamydia (in urethra and anus) was offered to participants in both cohorts., Results: In participants in the HIV positive cohort, 75% were hepatitis A seropositive, 56% had serological evidence of previous or current hepatitis B infection, and 24% had evidence of vaccination against hepatitis B infection. 19% of men tested positive for syphilis and 4% had evidence of recent infections. Compared with men in the HIV negative cohort, after adjustment for age, HIV positive participants had significantly higher prevalence of previous or current hepatitis B infection, syphilis, and anal gonorrhoea., Conclusion: This finding supports the need for frequent STI testing in HIV positive men to prevent morbidity and to decrease the risk of ongoing HIV transmission.

Background: Early detection and treatment of bacterial sexually transmitted infections has been advocated as an HIV prevention strategy., Aim: To inform screening guidelines, the incidence and risk factors for urethral and anal gonorrhoea and chlamydia were studied in a prospective cohort of community-based HIV negative homosexual men in Sydney, New South Wales, Australia., Methods: All participants were offered annual screening for gonorrhoea and chlamydia (study-visit diagnoses) on urine and anal swabs using nucleic acid amplification. Participants also reported diagnoses of gonorrhoea and chlamydia made elsewhere between interviews (interval diagnoses). All diagnoses were summed to create a combined incidence rate, and detailed data on specific sexual practices with casual and regular partners were collected., Results: Among 1427 men enrolled, the combined incidence rates were 3.49 and 2.96 per 100 person-years for urethral and anal gonorrhoea, respectively; and 7.43 and 4.98 per 100 person-years for urethral and anal chlamydia, respectively. Urethral infections were associated with unprotected anal intercourse (UAI) with HIV-positive partners (hazard ratio (HR) = 2.58, 95% CI 1.10 to 6.05 for urethral gonorrhoea) and with frequent insertive oral sex (p for trend 0.007 for urethral chlamydia). Anal infections were associated with receptive UAI (p for trend 0.001 for both anal gonorrhoea and chlamydia) and other receptive anal sexual practices. Stratified analyses showed the independence of the associations of insertive oral sex with urethral infections and of non-intercourse receptive anal practices with anal infections., Conclusion: Incident gonorrhoea and chlamydia were common. Risk behaviours for both urethral and anal infections were not restricted to UAI. Screening that includes tests for anal and urethral infections should be considered for all sexually active homosexual men, not just for those who report UAI.

Objective: To identify a specific marker of recent HIV-1 infection., Design: The humoral immune response in individuals recently infected with HIV-1 was followed by analysing the antibody isotype-specific response generated to HIV-1 antigens in sequential samples collected during and following seroconversion., Methods: Antibody isotype-specific HIV-1 Western blots were analysed to identify interactions indicative of recent HIV-1 infection. These responses were further quantified using an antibody isotype-specific enzyme-linked immunoabsorbent assay based on recombinant HIV-1 antigens., Results: During maturation of the immune response to HIV-1 infection, a rapid and enduring IgG1 isotype response was seen to all the major proteins transcribed by env, gag and pol. An early transient peak of IgG3 reactivity to p24 was observed over an interval of approximately 1-4 months following HIV-1 infection. The presence of IgG3 reactivity to p24 permitted established infection to be distinguished from recently infected individuals during this time period., Conclusion: An assay for anti-p24 IgG3 reactivity would provide an estimate of the incidence of HIV infection that may be applicable for epidemiological surveys as well as for monitoring new infections during vaccine trials and for managing treatment programmes.

In a prospective open-label study, 41 male subjects received nelfinavir, zidovudine, and lamivudine stratified as either: early stage (ES; negative/indeterminate Western blot; n = 19) or late stage (LS; positive Western blot; n = 22) primary HIV-1 infection. Despite higher median baseline HIV-1 RNA levels and lower CD4(+) cell numbers in the ES subjects, a significantly greater decline in viral load (-3.46 vs. -2.83 log(10) copies/ml; p = 0.023) and increase in CD4(+) cell number (+85 vs. +41 cells/month increase, p = 0.01) were observed over the first 3 months of therapy such that both groups had comparable results at 1 year. The proportion with HIV-1 RNA < 50 copies/mL at 1 year was similar (9 of 19 ES subjects and 11 of 22 LS subjects by intention-to-treat analysis). Memory CD4(+) cell numbers, and activated CD4(+) percentages, were also significantly improved in ES subjects. Despite poorer prognostic markers at baseline ES subjects achieved responses similar to those of LS subjects after 1 year of treatment.

CCR5 is the major coreceptor for human immunodeficiency virus (HIV) type 1 during primary infection. CCR5+ CD4 T lymphocytes were studied in subjects with primary HIV-1 infection (PHI) or acute Epstein-Barr virus (EBV) infection and in HIV-uninfected controls. The early decline of CD4 T lymphocytes during PHI resulted from depletion of CCR5- CD4 T lymphocytes. After antiretroviral therapy, Ki-67- CCR5- CD4 T cell counts rapidly increased in the circulation, which suggests that the initial decrease was due to an alteration in trafficking and/or sequestration. In the CCR5+ subset of CD4 T cells, there was an elevation in the proliferative (Ki-67+) fraction during PHI, yet their total number remained in the normal range. In contrast, in acute EBV infection, proliferating CCR5+ CD4 T cells accumulated to very high levels, suggesting they have an important role in the early antiviral response, which may be impaired in HIV-1 infection.

Objectives: To delineate and compare the nature and frequency of mutations known to confer resistance to HIV-1 nucleoside reverse transcriptase inhibitors in the cerebrospinal fluid (CSF) and blood compartments., Methods: Fifty-three paired CSF and plasma specimens had been prospectively collected and stored from 49 HIV-1 infected patients. These were tested using a commercially available line probe assay which allows the simultaneous detection of wild-type and drug selected variants conferring resistance to one or more drugs: zidovudine, didanosine, zalcitabine, and lamivudine., Results: Of the 53 (58%) paired samples, 31 could be amplified by nested PCR. The current assay's limitation for use with CSF is highlighted as 91% of blood samples amplified compared with 60% of CSF samples showing the assays inability to amplify viral loads below 1000 copies/ml. Of the 31 patients 21 (68%) had identical resistance patterns in the CSF and plasma; the other 10 (32%) patients had a resistance profile in the CSF that was different from that in their plasma. Of these, three samples demonstrated amino acid changes associated with high level zidovudine resistance in the CSF but the blood sample remained genotypically sensitive. Nine samples demonstrated resistance in blood but remained wild-type in the CSF. Resistant genotypes were detected in CSF for all nucleosides except didanosine., Conclusions: Differences in the positions and frequencies of wild-type and drug selected variants in specimens derived from the CSF and blood compartments were detected in a significant number of patients; this argues for the independent development of drug resistance in the CNS in some patients. These findings may have important implications in guiding antiretroviral therapy in HIV-1 infection.

Objectives: To describe point prevalence of HCV antibody and relevant risk behaviour among people who inject drugs and who attended selected needle and syringe programs throughout Australia in 1995, 1996 and 1997., Design and Setting: Repeated cross-sectional surveys of one week's duration were carried out in 21, 20 and 23 needle and syringe program sites throughout Australia in 1995, 1996 and 1997, respectively., Participants: All clients attending participating sites during the designated survey week were asked to complete a self-administered questionnaire and provide a finger-prick blood sample for HCV antibody testing., Main Outcome Measures: Prevalence of HCV antibody., Results: Survey response was 41% (n = 979) in 1995, 51% (n = 1463) in 1996 and 48% (n = 1699) in 1997. HCV prevalence declined significantly from 63% in 1995 to 51% in 1996 and 50% in 1997 (P < 0.001). Among respondents who reported injecting for less than three years, prevalence declined from 22% in 1995 to 13% in 1996 and 1997 (P < 0.001). Reported use of needles and syringes after someone else in the previous month declined from 31% in 1995 and 28% in 1996 to 15% in 1997 (P < 0.001)., Conclusions: Despite an apparent decline in HCV prevalence, carriage rates of HCV antibody remain high.

Antiretroviral therapy commenced during primary human immunodeficiency virus type 1 (HIV-1) infection (PHI) may limit the extent of viral replication and prevent early loss of HIV-specific CD4 lymphocyte function. We studied the effect of current standard therapy (2 nucleoside analogues and a protease inhibitor) in 16 patients with symptomatic PHI. In the 13 patients who completed 1 year of treatment, plasma HIV RNA was <50 copies/mL and median CD4 cell counts were comparable to HIV-uninfected controls, with naive (CD45RA+CD62L+), primed (CD45RO+), and T cell receptor Vbeta subsets all within normal ranges. However, HIV-1 DNA levels in treated and untreated PHI patients were similar. Furthermore, CD8 cell counts remained elevated, including activated (CD38+HLA-DR+), replicating (Ki-67+), and cytotoxic (perforin+CD28-) lymphocytes. In conclusion, early antiretroviral therapy resulted in clearance of viremia and prevented loss of crucial CD4 subsets. The persistence of HIV-1 DNA together with increased CD8 T lymphocyte turnover and activation indicate continued expression of viral antigens.

It is now apparent that a proportion of individuals (5-8%) remains clinically free of HIV-1 disease with normal levels of CD4+ lymphocytes (> or =500/microl) for more than 8 years following infection. However, the proportion of these individuals who ultimately progress to AIDS remains to be established. We determined the virological and immunological characteristics of a cohort of long-term nonprogressors in Australia and examined the role of these factors in predicting disease progression. Individuals with documented asymptomatic HIV-1 infection for at least 8 years with CD4+ lymphocyte counts >500 cells/microl were recruited from hospital clinics and general practices serving the eastern area of Australia. CD4+ lymphocyte count, rate of CD4+ lymphocyte change, CD8+ lymphocyte count, beta2-microglobulin, immune complex dissociated (ICD) HIV-1 p24 antigen, and plasma HIV-1 RNA were measured at baseline and multiple visits at 6-month intervals over an average period of 2 years. Up to November 1996, 67 study participants were recruited, of whom 72% had been infected with HIV-1 for at least 10 years. HIV-1 RNA correlated with beta2-microglobulin, ICD p24 antigen, and the ability to isolate virus in culture but not with levels of CD4+ or CD8+ lymphocytes. Serum beta2-microglobulin was a stronger predictor of CD4+ lymphocyte decline than HIV-1 RNA and the only factor significantly associated with CD4+ lymphocyte decline. These findings show that the serum concentration of beta2-microglobulin is a strong predictor of immunological progression in people with long-term asymptomatic HIV-1 infection and provides additional prognostic information to HIV-1 RNA in determining the risk of disease progression.

Objective: To determine whether needle and syringe exchange programs represent feasible sites to describe the prevalence of HIV and related risk behaviour among injecting drug users., Design: Cross-sectional survey., Setting: 21 needle and syringe exchange programs in all Australian jurisdictions., Participants: All persons attending the needle and syringe exchange programs over one week in March 1995 were eligible to participate in the study once., Intervention: Needle and syringe exchange attenders were asked to complete a brief, self-administered questionnaire and provide a finger-prick blood sample., Main Outcome Measures: Prevalence of HIV antibody, drug injecting and sexual behaviour, and survey cost., Results: Completed questionnaires with blood samples suitable for testing were provided by 1005 (42%) of 2373 individuals who attended the needle and syringe exchange programs during the survey week. Women were more likely than men to participate in the survey but there was no difference in the response rate by age group. The HIV prevalence was 2.1% and was significantly higher in men who described themselves as homosexual, compared to men who described themselves as heterosexual (22.5% v. 0.7%; P < 0.001). Thirty-one per cent of respondents reported using a syringe after someone else in the preceding month., Conclusion: Cross-sectional surveys of needle exchange clients offer a practical method for monitoring risk behaviour and seroprevalence of bloodborne viral infections.

The crystal structure, refractive indices, and phase-matching conditions for a new nonlinear optical material, L-histidine tetrafluoroborate (HFB), are reported. HFB grows readily, displays favorable mechanical characteristics, and has adequate birefringence to permit phase-matched parametric processes over much of its transparency range (250 nm to 1300 nm). The phase-matching loci and angular sensitivity for second-harmonic generation of 1064-nm light in single crystals of HFB were measured. The effective nonlinearity for HFB is comparable with that of beta-barium borate (~2 pm/V), and its angular sensitivity [delta(Deltak)/deltatheta] is somewhat smaller.

The presence of antibody to human immunodeficiency virus (HIV) in post-partum women may be inferred by screening the blood of their newborn babies, since maternal IgG antibodies freely cross the placenta. We tested a sample of 10,217 newborns from 10 hospitals covering three areas in Sydney and other metropolitan centres in New South Wales from April to July, 1989. None of the specimens gave a positive test for antibody to HIV. Thus, the prevalence of HIV positive serology in this sample of newborns was found to be zero. It was estimated that the seroprevalence of antibody to HIV among all neonates in the study area was between zero and 0.045% (99% confidence interval). Because newborns are an accessible group for the study of HIV, and can act as surrogates for their mothers, anonymous testing of this sentinel group will remove some of the limitations generalizing the information in the present database of HIV infection in Australia. This study provides baseline data and suggests that there is not a widespread epidemic of HIV infection among heterosexual persons in Australia at the present time and that routine antenatal testing of women for antibody to HIV may not be cost-effective. However, it will be important to repeat this study at regular intervals to detect any increase in HIV seroprevalence.

A study of five patients with severe rheumatoid vasculitis treated with cyclophosphamide was undertaken to determine whether immune complexes were present in serum and if their levels correlated with disease activity and response to treatment. Circulating immune complexes were measured by various techniques including the Clq binding and Raji cell radioimmunoassays and determination of the presence of cryoglobulins. Elevated levels of circulating immune complexes, hypocomplementemia, and high titer rheumatoid factor were present during active vasculitis. Clinical and serologic remissions were induced in all patients on cyclophosphamide. In two patients in remission, a rise in rheumatoid factor titer and immune complex levels was associated with an exacerbation of vasculitis and resolved on increased cyclophosphamide dosage. The Clq binding assay and rheumatoid factor titer correlated best with clinical activity. Thus, circulating immune complexes appear to be involved in the immunopathogenesis of rheumatoid vasculitis, which can be successfully treated with cyclophosphamide.

Sera from patients with progressive systemic sclerosis (PSS) and mixed connective tissue disease (MCTD) were studied for the presence of circulating immune complexes (CICs) by Clq precipitins, cryoglobulins and the Raji cell and Clq radioimmunoassays. The Raji cell assay was the most sensitive, detecting ICs in 82% of patients with MCTD and in 55% with PSS. However, the median value in MCTD was significantly higher than in PSS (79 vs 20 microgram equivalent AHG/ml serum), and in MCTD, unlike PSS, the CIC levels appeared to parallel disease activity. Ribonucleoprotein (RNP) antigen could not be demonstrated in the Raji cell bound complexes.