Characteristics of heterosexually-acquired compared to homosexually-acquired HIV and implications for clinical practice: results from the Australian HIV Observational Database.

Heterosexuals living with HIV report feeling additional HIV stigma compared to homosexual men, which may affect clinical outcomes. Yet, beyond routinely collected surveillance data, little is known about the characteristics of individuals who acquire HIV heterosexually and clinical outcomes by mode of sexual acquisition have not been directly compared. Using data from the Australian HIV Observational Database, we compared clinical characteristics of those with heterosexually-acquired (Het-HIV) to homosexually-acquired HIV (Hom-HIV) to investigate any differences and their implications for clinical management. 513 Het-HIV and 1467 Hom-HIV patients were included and contributed 3,127 and 9,457 person-years of follow-up, respectively. Compared with Hom-HIV, Het-HIV were more often born outside Australia (62.5% vs 39.9%, p<0.001), less likely to have Hepatitis C (4.8% vs 7.8%, p=0.029) and had lower median CD4 counts at diagnosis (292 vs 450 cells/µL, p<0.001) and cART initiation (270 vs 340 cells/µL, p<0.001). Despite these lower CD4 counts, there were no significant differences between groups for time to the major clinical endpoints of cART initiation, viral suppression, virological failure or all-cause mortality. Het-HIV had a lower risk of loss-to-follow-up than Hom-HIV (aHR 0.78; 95% CI 0.64-0.95). Further studies examining factors associated with, and interventions to inform retention in care are required.

MAP2 is differentially phosphorylated in schizophrenia, altering its function.

Schizophrenia (Sz) is a highly polygenic disorder, with common, rare, and structural variants each contributing only a small fraction of overall disease risk. Thus, there is a need to identify downstream points of convergence that can be targeted with therapeutics. Reduction of microtubule-associated protein 2 (MAP2) immunoreactivity (MAP2-IR) is present in individuals with Sz, despite no change in MAP2 protein levels. MAP2 is phosphorylated downstream of multiple receptors and kinases identified as Sz risk genes, altering its immunoreactivity and function. Using an unbiased phosphoproteomics approach, we quantified 18 MAP2 phosphopeptides, 9 of which were significantly altered in Sz subjects. Network analysis grouped MAP2 phosphopeptides into three modules, each with a distinct relationship to dendritic spine loss, synaptic protein levels, and clinical function in Sz subjects. We then investigated the most hyperphosphorylated site in Sz, phosphoserine1782 (pS1782). Computational modeling predicted phosphorylation of S1782 reduces binding of MAP2 to microtubules, which was confirmed experimentally. We generated a transgenic mouse containing a phosphomimetic mutation at S1782 (S1782E) and found reductions in basilar dendritic length and complexity along with reduced spine density. Because only a limited number of MAP2 interacting proteins have been previously identified, we combined co-immunoprecipitation with mass spectrometry to characterize the MAP2 interactome in mouse brain. The MAP2 interactome was enriched for proteins involved in protein translation. These associations were shown to be functional as overexpression of wild type and phosphomimetic MAP2 reduced protein synthesis in vitro. Finally, we found that Sz subjects with low MAP2-IR had reductions in the levels of synaptic proteins relative to nonpsychiatric control (NPC) subjects and to Sz subjects with normal and MAP2-IR, and this same pattern was recapitulated in S1782E mice. These findings suggest a new conceptual framework for Sz-that a large proportion of individuals have a "MAP2opathy"-in which MAP function is altered by phosphorylation, leading to impairments of neuronal structure, synaptic protein synthesis, and function.

Transcriptome alterations of prefrontal cortical parvalbumin neurons in schizophrenia.

Schizophrenia (SZ) is associated with dysfunction of the dorsolateral prefrontal cortex (DLPFC). This dysfunction is manifest as cognitive deficits that appear to arise from disturbances in gamma frequency oscillations. These oscillations are generated in DLPFC layer 3 (L3) via reciprocal connections between pyramidal cells (PCs) and parvalbumin (PV)-containing interneurons. The density of cortical PV neurons is not altered in SZ, but expression levels of several transcripts involved in PV cell function, including PV, are lower in the disease. However, the transcriptome of PV cells has not been comprehensively assessed in a large cohort of subjects with SZ. In this study, we combined an immunohistochemical approach, laser microdissection, and microarray profiling to analyze the transcriptome of DLPFC L3 PV cells in 36 matched pairs of SZ and unaffected comparison subjects. Over 800 transcripts in PV neurons were identified as differentially expressed in SZ subjects; most of these alterations have not previously been reported. The altered transcripts were enriched for pathways involved in mitochondrial function and tight junction signaling. Comparison with the transcriptome of L3 PCs from the same subjects revealed both shared and distinct disease-related effects on gene expression between cell types. Furthermore, network structures of gene pathways differed across cell types and subject groups. These findings provide new insights into cell type-specific molecular alterations in SZ which may point toward novel strategies for identifying therapeutic targets.

Cannabis-associated psychosis: Neural substrate and clinical impact.

Prospective epidemiological studies have consistently demonstrated that cannabis use is associated with an increased subsequent risk of both psychotic symptoms and schizophrenia-like psychoses. Early onset of use, daily use of high-potency cannabis, and synthetic cannabinoids carry the greatest risk. The risk-increasing effects are not explained by shared genetic predisposition between schizophrenia and cannabis use. Experimental studies in healthy humans show that cannabis and its active ingredient, delta-9-tetrahydrocannabinol (THC), can produce transient, dose-dependent, psychotic symptoms, as well as an array of psychosis-relevant behavioral, cognitive and psychophysiological effects; the psychotogenic effects can be ameliorated by cannabidiol (CBD). Findings from structural imaging studies in cannabis users have been inconsistent but functional MRI studies have linked the psychotomimetic and cognitive effects of THC to activation in brain regions implicated in psychosis. Human PET studies have shown that acute administration of THC weakly releases dopamine in the striatum but that chronic users are characterised by low striatal dopamine. We are beginning to understand how cannabis use impacts on the endocannabinoid system but there is much still to learn about the biological mechanisms underlying how cannabis increases risk of psychosis. This article is part of the Special Issue entitled "A New Dawn in Cannabinoid Neurobiology".

DNA methylation as a putative mechanism for reduced dendritic spine density in the superior temporal gyrus of subjects with schizophrenia.

Reduced dendritic spine density (DSD) in cortical layer 3 of the superior temporal gyrus (STG), and multiple other brain regions, is consistently observed in postmortem studies of schizophrenia (SZ). Elucidating the molecular mechanisms of this intermediate phenotype holds promise for understanding SZ pathophysiology, identifying SZ treatment targets and developing animal models. DNA methylation (DNAm), the addition of a methyl group to a cytosine nucleotide, regulates gene transcription and is a strong candidate for such a mechanism. We tested the hypothesis that DNAm correlates with DSD in the human STG and that this relationship is disrupted in SZ. We used the Illumina Infinium HumanMethylation450 Beadchip Array to quantify DNAm on a genome-wide scale in the postmortem STG from 22 SZ subjects and matched non-psychiatric control (NPC) subjects; DSD measures were available for 17 of the 22 subject pairs. We found DNAm to correlate with DSD at more sites than expected by chance in NPC, but not SZ, subjects. In addition, we show that the slopes of the linear DNAm-DSD correlations differed between SZ and NPC subjects at more sites than expected by chance. From these data, we identified 2 candidate genes for mediating DSD abnormalities in SZ: brain-specific angiogenesis inhibitor 1-associated protein 2 (BAIAP2) and discs large, Drosophila, homolog of, 1 (DLG1). Together, these data suggest that altered DNAm in SZ may be a mechanism for SZ-related DSD reductions.

Attention-deficit/hyperactivity disorder casts a long shadow: findings from a population-based study of adult women with self-reported ADHD.

BACKGROUND: To develop a sociodemographic and health profile of women with self-reported attention deficit/hyperactivity disorder (ADHD) in comparison to women without. METHODS: Chi-square tests and logistic regression analyses were conducted on data from the nationally representative Canadian Community Health Survey-Mental Health (2012) comparing 107 women aged 20 to 39 years (inclusive) with ADHD to 3801 without ADHD. Depression, generalized anxiety disorder and substance abuse were measured using the WHO-CIDI. RESULTS: Women with ADHD had triple the prevalence of insomnia, chronic pain, suicidal ideation, childhood sexual abuse and generalized anxiety disorder and double the prevalence of substance abuse, current smoking, depressive disorders, severe poverty and childhood physical abuse in comparison with women without ADHD (all P < 0.001). Even after adjustments for age, race, education and income, women with ADHD had substantially higher odds of a wide range of problems. CONCLUSION: Our results suggest that women with ADHD are particularly vulnerable to early adversities, health and mental health problems.

Cortical GABA markers identify a molecular subtype of psychotic and bipolar disorders.

BACKGROUND: Deficits in gamma aminobutyric acid (GABA) neuron-related markers, including the GABA-synthesizing enzyme GAD67, the calcium-binding protein parvalbumin, the neuropeptide somatostatin, and the transcription factor Lhx6, are most pronounced in a subset of schizophrenia subjects identified as having a 'low GABA marker' (LGM) molecular phenotype. Furthermore, schizophrenia shares degrees of genetic liability, clinical features and cortical circuitry abnormalities with schizoaffective disorder and bipolar disorder. Therefore, we determined the extent to which a similar LGM molecular phenotype may also exist in subjects with these disorders. METHOD: Transcript levels for GAD67, parvalbumin, somatostatin, and Lhx6 were quantified using quantitative PCR in prefrontal cortex area 9 of 184 subjects with a diagnosis of schizophrenia (n = 39), schizoaffective disorder (n = 23) or bipolar disorder (n = 35), or with a confirmed absence of any psychiatric diagnoses (n = 87). A blinded clustering approach was employed to determine the presence of a LGM molecular phenotype across all subjects. RESULTS: Approximately 49% of the subjects with schizophrenia, 48% of the subjects with schizoaffective disorder, and 29% of the subjects with bipolar disorder, but only 5% of unaffected subjects, clustered in the cortical LGM molecular phenotype. CONCLUSIONS: These findings support the characterization of psychotic and bipolar disorders by cortical molecular phenotype which may help elucidate more pathophysiologically informed and personalized medications.

Exploring the impact of sample flowrate on in vitro measurements of metered dose inhaler performance.

Pharmacopoeial methods for measurement of the aerodynamic particle size distribution (APSD) of metered dose inhalers (MDIs) by cascade impaction specify a sampling flow rate of 28.3L/min. However, there is little data within the literature to rationalize this figure, or to support its clinical relevance. In addition, the standard United States Pharmacopoeia Induction Port (USP IP) used for testing is known to inaccurately reflect deposition behavior in the upper airway, further compromising the relevance of testing, for product development. This article describes experimental studies of the effect of sampling flow rate on APSD data gathered using an Andersen Cascade Impactor (ACI). Tests were carried out using two different formulations to assess the influence of formulation composition. In addition, comparative testing with an Alberta Idealised Throat, in place of the USP IP, to ensure more realistic representation of the upper airway. The results show how measured APSD and fine particle dose, the dose than on the basis of size would be expected to deposit in the lung, vary as a function of test methodology, providing insight as to how the testing can be modified towards greater clinical relevance.

Will targeting oropharyngeal gonorrhoea delay the further emergence of drug-resistant Neisseria gonorrhoeae strains?

Gonorrhoea is an important sexually transmitted infection associated with serious complications and enhanced HIV transmission. Oropharyngeal infections are often asymptomatic and will only be detected by screening. Gonococcal culture has low sensitivity (<50%) for detecting oropharyngeal gonorrhoea, and, although not yet approved commercially, nucleic acid amplification tests (NAAT) are the assay of choice. Screening for oropharyngeal gonorrhoea should be performed in high-risk populations, such as men-who-have-sex-with-men(MSM). NAATs have a poor positive predictive value when used in low-prevalence populations. Gonococci have repeatedly thwarted gonorrhoea control efforts since the first antimicrobial agents were introduced. The oropharyngeal niche provides an enabling environment for horizontal transfer of genetic material from commensal Neisseria and other bacterial species to Neisseria gonorrhoeae. This has been the mechanism responsible for the generation of mosaic penA genes, which are responsible for most of the observed cases of resistance to extended-spectrum cephalosporins (ESC). As antimicrobial-resistant gonorrhoea is now an urgent public health threat, requiring improved antibiotic stewardship, laboratory-guided recycling of older antibiotics may help reduce ESC use. Future trials of antimicrobial agents for gonorrhoea should be powered to test their efficacy at the oropharynx as this is the anatomical site where treatment failure is most likely to occur. It remains to be determined whether a combination of frequent screening of high-risk individuals and/or laboratory-directed fluoroquinolone therapy of oropharyngeal gonorrhoea will delay the further emergence of drug-resistant N. gonorrhoeae strains.

Distinctive transcriptome alterations of prefrontal pyramidal neurons in schizophrenia and schizoaffective disorder.

Schizophrenia is associated with alterations in working memory that reflect dysfunction of dorsolateral prefrontal cortex (DLPFC) circuitry. Working memory depends on the activity of excitatory pyramidal cells in DLPFC layer 3 and, to a lesser extent, in layer 5. Although many studies have profiled gene expression in DLPFC gray matter in schizophrenia, little is known about cell-type-specific transcript expression in these two populations of pyramidal cells. We hypothesized that interrogating gene expression, specifically in DLPFC layer 3 or 5 pyramidal cells, would reveal new and/or more robust schizophrenia-associated differences that would provide new insights into the nature of pyramidal cell dysfunction in the illness. We also sought to determine the impact of other variables, such as a diagnosis of schizoaffective disorder or medication use at the time of death, on the patterns of gene expression in pyramidal neurons. Individual pyramidal cells in DLPFC layers 3 or 5 were captured by laser microdissection from 36 subjects with schizophrenia or schizoaffective disorder and matched normal comparison subjects. The mRNA from cell collections was subjected to transcriptome profiling by microarray followed by quantitative PCR validation. Expression of genes involved in mitochondrial (MT) or ubiquitin-proteasome system (UPS) functions were markedly downregulated in the patient group (P-values for MT-related and UPS-related pathways were <10(-7) and <10(-5), respectively). MT-related gene alterations were more prominent in layer 3 pyramidal cells, whereas UPS-related gene alterations were more prominent in layer 5 pyramidal cells. Many of these alterations were not present, or found to a lesser degree, in samples of DLPFC gray matter from the same subjects, suggesting that they are pyramidal cell specific. Furthermore, these findings principally reflected alterations in the schizophrenia subjects were not present or present to a lesser degree in the schizoaffective disorder subjects (diagnosis of schizoaffective disorder was the most significant covariate, P<10(-6)) and were not attributable to factors frequently comorbid with schizophrenia. In summary, our findings reveal expression deficits in MT- and UPS-related genes specific to layer 3 and/or layer 5 pyramidal cells in the DLPFC of schizophrenia subjects. These cell type-specific transcriptome signatures are not characteristic of schizoaffective disorder, providing a potential molecular-cellular basis of differences in clinical phenotypes.

Altered parvalbumin basket cell inputs in the dorsolateral prefrontal cortex of schizophrenia subjects.

Cortical circuitry dysfunction in schizophrenia has been studied at many different levels of resolution, but not at the most basic unit of network organization--synaptic inputs. Multi-label electron or confocal light microscopy is required to examine specific types of synaptic inputs, and application of these methods to quantitatively study disease-related changes in human postmortem tissue has not been feasible for technical reasons. We recently developed a multi-label confocal light microscopic approach that makes possible the systematic identification and quantification of synaptic inputs, and of the relative levels of proteins localized to these inputs, in human postmortem tissue. We applied this approach to quantify parvalbumin basket cell (PVBC) inputs in area 9 of the dorsolateral prefrontal cortex from schizophrenia and matched comparison subjects. Tissue sections were triple-labeled for the 65 kD isoform of glutamic acid decarboxylase (GAD65), PV and the GABA(A) receptor α1 subunit. PVBC axonal boutons were defined as PV/GAD65 dual-labeled puncta, and PVBC inputs were defined as a PVBC bouton that overlapped a GABA(A) receptor α1 subunit punctum. The density of PVBC inputs was unchanged in subjects with schizophrenia, but levels of PV protein were lower in PVBC boutons. In concert with prior reports, these findings indicate that PVBC dysfunction in schizophrenia reflects molecular and not structural alterations in these cells and their axon terminals.

Distribution and risk factors of Trichomonas vaginalis infection in England: an epidemiological study using electronic health records from sexually transmitted infection clinics, 2009-2011.

We used data from the Genitourinary Medicine Clinic Activity Dataset (GUMCAD) over a 3-year period (2009-2011) to investigate the distribution and risk factors of Trichomonas vaginalis infection in England. Socio-demographic and clinical risk factors associated with a diagnosis of T. vaginalis were explored using multivariable logistic regression. Rates of T. vaginalis infection were highest in London and the West Midlands. For men and women, T. vaginalis infection was significantly associated with: older age compared to those aged 20-24 years, non-white ethnicity (in particular black Caribbean and black 'other' ethnic groups), and birth in the Caribbean vs. birth in the UK. Current gonorrhoea or chlamydia infection was associated with a diagnosis of T. vaginalis in women. Further research is required to assess the public health impact and cost-effectiveness of introducing targeted screening for women at high risk of infection in areas of higher prevalence.

Towards the bioequivalence of pressurised metered dose inhalers 1: design and characterisation of aerodynamically equivalent beclomethasone dipropionate inhalers with and without glycerol as a non-volatile excipient.

A series of semi-empirical equations were utilised to design two solution based pressurised metered dose inhaler (pMDI) formulations, with equivalent aerosol performance but different physicochemical properties. Both inhaler formulations contained the drug, beclomethasone dipropionate (BDP), a volatile mixture of ethanol co-solvent and propellant (hydrofluoroalkane-HFA). However, one formulation was designed such that the emitted aerosol particles contained BDP and glycerol, a common inhalation particle modifying excipient, in a 1:1 mass ratio. By modifying the formulation parameters, including actuator orifice, HFA and metering volumes, it was possible to produce two formulations (glycerol-free and glycerol-containing) which had identical mass median aerodynamic diameters (2.4µm±0.1 and 2.5µm±0.2), fine particle dose (⩽5µm; 66µg±6 and 68µg±2) and fine particle fractions (28%±2% and 30%±1%), respectively. These observations demonstrate that it is possible to engineer formulations that generate aerosol particles with very different compositions to have similar emitted dose and in vitro deposition profiles, thus making them equivalent in terms of aerosol performance. Analysis of the physicochemical properties of each formulation identified significant differences in terms of morphology, thermal properties and drug dissolution of emitted particles. The particles produced from both formulations were amorphous; however, the formulation containing glycerol generated particles with a porous structure, while the glycerol-free formulation generated particles with a primarily spherical morphology. Furthermore, the glycerol-containing particles had a significantly lower dissolution rate (7.8%±2.1%, over 180min) compared to the glycerol-free particles (58.0%±2.9%, over 60min) when measured using a Franz diffusion cell. It is hypothesised that the presence of glycerol in the emitted aerosol particles altered solubility and drug transport, which may have implications for BDP pharmacokinetics after deposition in the respiratory tract.

Towards the bioequivalence of pressurised metered dose inhalers 2. Aerodynamically equivalent particles (with and without glycerol) exhibit different biopharmaceutical profiles in vitro.

Two solution-based pressurised metered dose inhaler (pMDI) formulations were prepared such that they delivered aerosols with identical mass median aerodynamic diameters, but contained either beclomethasone dipropionate (BDP) alone (glycerol-free formulation) or BDP and glycerol in a 1:1 mass ratio (glycerol-containing formulation). The two formulations were deposited onto Calu-3 respiratory epithelial cell layers cultured at an air interface. Equivalent drug mass (∼1000ng or ∼2000ng of the formulation) or equivalent particle number (1000ng of BDP in the glycerol-containing versus 2000ng of BDP in the glycerol-free formulation) were deposited as aerosolised particles on the air interfaced surface of the cell layers. The transfer rate of BDP across the cell layer after deposition of the glycerol-free particles was proportional to the mass deposited. In comparison, the transfer of BDP from the glycerol-containing formulation was independent of the mass deposited, suggesting that the release of BDP is modified in the presence of glycerol. The rate of BDP transfer (and the extent of metabolism) over 2h was faster when delivered in glycerol-free particles, 465.01ng±95.12ng of the total drug (20.99±4.29%; BDP plus active metabolite) transported across the cell layer, compared to 116.17ng±3.07ng (6.07±0.16%) when the equivalent mass of BDP was deposited in glycerol-containing particles. These observations suggest that the presence of glycerol in the maturated aerosol particles may influence the disposition of BDP in the lungs.

The role of core groups in the emergence and dissemination of antimicrobial-resistant N gonorrhoeae.

Core groups contain individuals who are regularly infected with Neisseria gonorrhoeae and are able to transmit their infection to a large number of sexual partners. Classical core groups, such as sex workers and their male partners, or men who have sex with men (MSM), have contributed to the emergence and spread of antimicrobial-resistant N gonorrhoeae over many years. Sex workers and their clients were the most important core group driving the dissemination of penicillinase-producing N gonorrhoeae in the 1970s. Such individuals have continued to contribute to penicillinase-producing N gonorrhoeae outbreaks as well as to the subsequent emergence of gonococcal resistance to fluoroquinolones, macrolides, spectinomycin and cephalosporins in various settings. MSM have been a very important core group since the 1980s, first with the spread of TetM-expressing N gonorrhoeae and, second, with the dissemination of fluoroquinolone-resistant N gonorrhoeae. MSM-associated sexual networks have most recently been critical to the spread of gonococci resistant to third generation extended spectrum cephalosporins, including cefixime and ceftriaxone. Individuals within other core groups have also been linked to the transmission of antimicrobial-resistant gonorrhoea, such as military personnel, travellers, drug users, young adults, older men and members of street gangs. Understanding core behaviours and their geospatial clustering is essential for an optimal public health response to the rising prevalence of antimicrobial-resistant gonorrhoea. Furthermore, rapid and effective treatment of N gonorrhoeae infections in core individuals and their sexual partners should be a priority for gonorrhoea control programmes.

Functional properties and short-term dynamics of unidirectional and reciprocal synaptic connections between layer 2/3 pyramidal cells and fast-spiking interneurons in juvenile rat prefrontal cortex.

The interactions between inhibitory fast-spiking (FS) interneurons and excitatory pyramidal neurons contribute to the fundamental properties of cortical networks. An important role for FS interneurons in mediating rapid inhibition in local sensory and motor cortex microcircuits and processing thalamic inputs to the cortex has been shown in multiple reports; however, studies in the prefrontal cortex, a key neocortical region supporting working memory, are less numerous. In the present work, connections between layer 2/3 pyramidal cells and FS interneurons were studied with paired whole-cell recordings in acute neocortical slices of the medial prefrontal cortex from juvenile rats. The connection rate between FS interneurons and pyramidal neurons was about 40% in each direction with 16% of pairs connected reciprocally. Excitatory and inhibitory connections had a high efficacy and a low neurotransmission failure rate. Sustained presynaptic activity decreased the amplitude of responses and increased the failure rate more in excitatory connections than in inhibitory connections. In the reciprocal connections between the FS and pyramidal neurons, inhibitory and excitatory neurotransmission was more efficient and had a lower failure rate than in the unidirectional connections; the differences increased during the train stimulation. These results suggest the presence of distinct preferential subnetworks between FS interneurons and pyramidal cells in the rat prefrontal cortex that might be specific for this cortical area.

Prenatal ontogeny as a susceptibility period for cortical GABA neuron disturbances in schizophrenia.

Cognitive deficits in schizophrenia have been linked to disturbances in GABA neurons in the prefrontal cortex (PFC). Furthermore, cognitive deficits in schizophrenia appear well before the onset of psychosis and have been reported to be present during early childhood and even during the first year of life. Taken together, these data raise the following question: Does the disease process that produces abnormalities in prefrontal GABA neurons in schizophrenia begin prenatally and disrupt the ontogeny of cortical GABA neurons? Here, we address this question through a consideration of evidence that genetic and/or environmental insults that occur during gestation initiate a pathogenetic process that alters cortical GABA neuron ontogeny and produces the pattern of GABA neuron abnormalities, and consequently cognitive difficulties, seen in schizophrenia. First, we review available evidence from postmortem human brain tissue studies characterizing alterations in certain subpopulations of prefrontal GABA neuron that provide clues to a prenatal origin in schizophrenia. Second, we review recent discoveries of transcription factors, cytokine receptors, and other developmental regulators that govern the birth, migration, specification, maturation, and survival of different subpopulations of prefrontal GABA neurons. Third, we discuss recent studies demonstrating altered expression of these ontogenetic factors in the PFC in schizophrenia. Fourth, we discuss the potential role of disturbances in the maternal-fetal environment such as maternal immune activation in the development of GABA neuron dysfunction. Finally, we propose critical questions that need to be answered in future research to further investigate the role of altered GABA neuron ontogeny in the pathogenesis of schizophrenia.

Determination of Neisseria gonorrhoeae susceptibility to ciprofloxacin in clinical specimens from men using a real-time PCR assay.

A real-time PCR (RT-PCR) assay was modified to simultaneously detect Neisseria gonorrhoeae and to determine gonococcal susceptibility to ciprofloxacin using clinical samples. The modified RT-PCR assay was validated using DNA extracted from 40 linked isolates and urethral swabs, 24 of which had linked first-pass urine samples, obtained from men presenting with urethral gonorrhoea. The RT-PCR assay enabled amplification of N. gonorrhoeae dcmH, gyrA and parC genes. The quinolone resistance-determining regions (QRDRs) of the isolates' gyrA and parC genes were sequenced. Following successful validation, 33 first-pass urine-derived DNA extracts, obtained from men with gonorrhoea, were tested with the assay and results were compared with blinded ciprofloxacin susceptibility data. Gonococcal susceptibility to ciprofloxacin correlated perfectly with gyrA amplicon generation. No gyrA amplicons were detected for gonococcal infections due to ciprofloxacin-intermediate/resistant organisms. Amplification of parC correlated less well with ciprofloxacin susceptibility phenotypes. Simultaneous non-generation of gyrA and parC amplicons consistently predicted the presence of ciprofloxacin-resistant gonococci. Characteristic point mutations in the gyrA/parC QRDRs were found in DNA amplified from those extracts that failed to produce gyrA/parC amplicons. The RT-PCR assay performed well with DNA extracted from first-pass urine specimens and results correlated perfectly with ciprofloxacin susceptibility phenotypes. In conclusion, the modified RT-PCR assay can detect N. gonorrhoeae in DNA extracted from first-pass urine specimens of men with urethral gonorrhoea and accurately predicts gonococcal susceptibility to ciprofloxacin. This molecular assay provides a useful tool for surveillance and patient management in settings where fluoroquinolones can still be used for treatment of gonorrhoea.

Dendritic spine pathology in schizophrenia.

Schizophrenia is a neurodevelopmental disorder whose clinical features include impairments in perception, cognition and motivation. These impairments reflect alterations in neuronal circuitry within and across multiple brain regions that are due, at least in part, to deficits in dendritic spines, the site of most excitatory synaptic connections. Dendritic spine alterations have been identified in multiple brain regions in schizophrenia, but are best characterized in layer 3 of the neocortex, where pyramidal cell spine density is lower. These spine deficits appear to arise during development, and thus are likely the result of disturbances in the molecular mechanisms that underlie spine formation, pruning, and/or maintenance. Each of these mechanisms may provide insight into novel therapeutic targets for preventing or repairing the alterations in neural circuitry that mediate the debilitating symptoms of schizophrenia.