Electrophysiological measures from human iPSC-derived neurons are associated with schizophrenia clinical status and predict individual cognitive performance.

Neurons derived from human induced pluripotent stem cells (hiPSCs) have been used to model basic cellular aspects of neuropsychiatric disorders, but the relationship between the emergent phenotypes and the clinical characteristics of donor individuals has been unclear. We analyzed RNA expression and indices of cellular function in hiPSC-derived neural progenitors and cortical neurons generated from 13 individuals with high polygenic risk scores (PRSs) for schizophrenia (SCZ) and a clinical diagnosis of SCZ, along with 15 neurotypical individuals with low PRS. We identified electrophysiological measures in the patient-derived neurons that implicated altered Na+ channel function, action potential interspike interval, and gamma-aminobutyric acid-ergic neurotransmission. Importantly, electrophysiological measures predicted cardinal clinical and cognitive features found in these SCZ patients. The identification of basic neuronal physiological properties related to core clinical characteristics of illness is a potentially critical step in generating leads for novel therapeutics.

SUFI: an automated approach to spectral unmixing of fluorescent multiplex images captured in mouse and post-mortem human brain tissues.

BACKGROUND: Multispectral fluorescence imaging coupled with linear unmixing is a form of image data collection and analysis that allows for measuring multiple molecular signals in a single biological sample. Multiple fluorescent dyes, each measuring a unique molecule, are simultaneously measured and subsequently "unmixed" to provide a read-out for each molecular signal. This strategy allows for measuring highly multiplexed signals in a single data capture session, such as multiple proteins or RNAs in tissue slices or cultured cells, but can often result in mixed signals and bleed-through problems across dyes. Existing spectral unmixing algorithms are not optimized for challenging biological specimens such as post-mortem human brain tissue, and often require manual intervention to extract spectral signatures. We therefore developed an intuitive, automated, and flexible package called SUFI: spectral unmixing of fluorescent images. RESULTS: This package unmixes multispectral fluorescence images by automating the extraction of spectral signatures using vertex component analysis, and then performs one of three unmixing algorithms derived from remote sensing. We evaluate these remote sensing algorithms' performances on four unique biological datasets and compare the results to unmixing results obtained using ZEN Black software (Zeiss). We lastly integrate our unmixing pipeline into the computational tool dotdotdot, which is used to quantify individual RNA transcripts at single cell resolution in intact tissues and perform differential expression analysis, and thereby provide an end-to-end solution for multispectral fluorescence image analysis and quantification. CONCLUSIONS: In summary, we provide a robust, automated pipeline to assist biologists with improved spectral unmixing of multispectral fluorescence images.

The world needs better male contraceptives: What is taking so long?

Forty percent of US pregnancies are unintended despite currently available contraceptives. A substantial number of men use the currently available methods of male contraception, condoms and vasectomy, and a large majority would be interested in novel forms of male contraception if available. Research into male contraception has been ongoing for more than 50 years, with hormonal contraceptives nearing clinical utility and non-hormonal methods hopefully becoming available, albeit with a longer time frame. However, uncertainly regarding benchmarks for the efficacy and safety of male contraception continue to be an issue with development and regulatory approval. In addition, pharmaceutical industry support is minimal with the NIH and Foundations being the main research funders. Given the continuing high rates of unintended pregnancy, many of which are now occurring in areas with extremely restricted access to legal abortion, additional focus and investment in male contraceptive development is imperative.

spatialLIBD: an R/Bioconductor package to visualize spatially-resolved transcriptomics data.

BACKGROUND: Spatially-resolved transcriptomics has now enabled the quantification of high-throughput and transcriptome-wide gene expression in intact tissue while also retaining the spatial coordinates. Incorporating the precise spatial mapping of gene activity advances our understanding of intact tissue-specific biological processes. In order to interpret these novel spatial data types, interactive visualization tools are necessary. RESULTS: We describe spatialLIBD, an R/Bioconductor package to interactively explore spatially-resolved transcriptomics data generated with the 10x Genomics Visium platform. The package contains functions to interactively access, visualize, and inspect the observed spatial gene expression data and data-driven clusters identified with supervised or unsupervised analyses, either on the user's computer or through a web application. CONCLUSIONS: spatialLIBD is available at https://bioconductor.org/packages/spatialLIBD . It is fully compatible with SpatialExperiment and the Bioconductor ecosystem. Its functionality facilitates analyzing and interactively exploring spatially-resolved data from the Visium platform.

Male Hormonal Contraception.

The economic and public health burdens of unplanned pregnancies are evident globally. Since the introduction of the condom >300 years ago, assumptions about male willingness to participate in contraception, as well as concerns about failure rates and side effects, have stagnated the development of additional reversible male contraceptives. However, changing attitudes and recent research advances have generated renewed interest in developing reversible male contraceptives. To achieve effective and reversible suppression of spermatogenesis, male hormonal contraception relies on suppression of testicular testosterone and sperm production using an androgen-progestin combination. While these may be associated with side effects-changes in libido, weight, hematocrit, and cholesterol-recently, novel androgens and progestins have shown promise for a "male pill" with reduced side effects. Here we summarize landmark studies in male contraceptive development, showcase the most recent advances, and look into the future of this field, which has the potential to greatly impact global public health.

CaPTure: Calcium PeakToolbox for analysis of in vitro calcium imaging data.

BACKGROUND: Calcium imaging is a powerful technique for recording cellular activity across large populations of neurons. However, analysis methods capable of single-cell resolution in cultured neurons, especially for cultures derived from human induced pluripotent stem cells (hiPSCs), are lacking. Existing methods lack scalability to accommodate high-throughput comparisons between multiple lines, across developmental timepoints, or across pharmacological manipulations. RESULTS: To address this need we developed CaPTure, a scalable, automated Ca2+ imaging analysis pipeline ( https://github.com/LieberInstitute/CaPTure ). CaPTuredetects neurons, classifies and quantifies spontaneous activity, quantifies synchrony metrics, and generates cell- and network-specific metrics that facilitate phenotypic discovery. The method is compatible with parallel processing on computing clusters without requiring significant user input or parameter modification. CONCLUSION: CaPTure allows for rapid assessment of neuronal activity in cultured cells at cellular resolution, rendering it amenable to high-throughput screening and phenotypic discovery. The platform can be applied to both human- and rodent-derived neurons and is compatible with many imaging systems.

Clinical utility and cost-effectiveness analysis of chromosome testing concomitant with chromosomal microarray of patients with constitutional disorders in a U.S. academic medical center.

Chromosomal microarray (CMA) is now widely used as first-tier testing for the detection of copy number variants (CNVs) and absence of heterozygosity (AOH) in patients with multiple congenital anomalies (MCA), autism spectrum disorder (ASD), developmental delay (DD), and/or intellectual disability (ID). Chromosome analysis is commonly used to complement CMA in the detection of balanced genomic aberrations. However, the cost-effectiveness and the impact on clinical management of chromosome analysis concomitant with CMA were not well studied, and there is no consensus on how to best utilize these two tests. To assess the clinical utility and cost-effectiveness of chromosome analysis concomitant with CMA in patients with MCA, ASD, DD, and/or ID, we retrospectively analyzed 3,360 postnatal cases for which CMA and concomitant chromosome analysis were performed in the Colorado Genetic Laboratory (CGL) at the University Of Colorado School Of Medicine. Chromosome analysis alone yielded a genetic diagnosis in two patients (0.06%) and contributed additional information to CMA results in 199 (5.92%) cases. The impact of abnormal chromosome results on patient management was primarily related to counseling for reproductive and recurrence risks assessment (101 cases, 3.01%) while a few (5 cases, 0.15%) led to changes in laboratory testing and specialist referral (25 cases, 0.74%). The incremental cost-effectiveness ratio (ICER) of combined testing demonstrated the cost of each informative chromosome finding was significantly higher for patients with clinically insignificant (CI) CMA findings versus clinically significant (CS) CMA results. Our results suggest that a stepwise approach with CMA testing with reflex to chromosome analysis on cases with CS CMA findings is a more cost-effective testing algorithm for patients with MCA, ASD, and/or DD/ID.

Human Immunodeficiency Virus Is Associated With Higher Levels of Systemic Inflammation Among Kenyan Adults Despite Viral Suppression.

BACKGROUND: Systemic inflammation independently predicts future cardiovascular events and is associated with a 2-fold increase in cardiovascular disease (CVD) risk among persons living with human immunodeficiency virus (PLHIV). We examined the association between inflammatory markers, HIV status, and traditional CVD risk factors. METHODS: We conducted a cross-sectional study of Kenyan adults with and without HIV seeking care at Kisumu County Hospital. Using a multiplex immunoassay, we measured interleukin (IL) 1ß, IL-6, tumor necrosis factor α (TNF-α), and high-sensitivity C-reactive protein (hsCRP) concentrations. We compared inflammatory marker concentrations by HIV status using the Wilcoxon rank-sum test. Multivariable linear regression was used to evaluate associations between inflammatory biomarkers and HIV status, adjusting for CVD risk factors. RESULTS: We enrolled 286 PLHIV and 277 HIV-negative participants. Median duration of antiretroviral therapy for PLHIV was 8 years (interquartile range, 4-10) and 96% were virally suppressed. PLHIV had a 51% higher mean IL-6 concentration (P < .001), 39% higher mean IL-1ß (P = .005), 40% higher mean TNF-α (P < .001), and 27% higher mean hsCRP (P = .008) compared with HIV-negative participants, independent of CVD risk factors. Male sex, older age, and obesity were associated with higher concentrations of inflammatory markers. Restricting to PLHIV, viral load of ≥1000 copies/mL was associated with higher TNF-α levels (P = .013). CONCLUSIONS: We found higher levels of systemic inflammatory biomarkers among PLHIV who were virally suppressed, and this was independent of traditional CVD risk factors. Further longitudinal analyses to determine whether these inflammatory markers predict future CVD events, and are possible therapeutic targets among PLHIV, are warranted.

Longitudinal changes in plasma sex hormone concentrations correlate with changes in CT-measured regional adiposity among Japanese American men over 10 years.

OBJECTIVE: Ageing in male adults is typically accompanied by adiposity accumulation and changes in circulating sex hormone concentrations. We hypothesized that an ageing-associated increase in oestrogens and decrease in androgens would correlate with an increase in adiposity. DESIGN: 10-year prospective, observational study. STUDY SUBJECTS: A total of 190, community-dwelling men in the Japanese American Community Diabetes Study. MEASUREMENTS: At 0 and 10 years, CT scanning quantified intra-abdominal fat (IAF) and subcutaneous fat (SCF) areas while plasma concentrations of oestradiol, oestrone, testosterone and dihydrotestosterone were measured by liquid chromatography-tandem-mass spectrometry at each time point. Multivariate linear regression analyses assessed correlations between 10-year changes in hormone concentrations and IAF or SCF, adjusting for age and baseline fat depot area. RESULTS: Participants were middle-aged [median 54.8 years, interquartile range (IQR) 39.9-62.8] men and mostly overweight by Asian criterion (median BMI 24.9, IQR 23.3-27.1) and with few exceptions had normal sex-steroid concentrations. Median oestradiol and dihydrotestosterone did not change significantly between 0 and 10 years (P = .084 and P = .596, respectively) while median oestrone increased (P < .001) and testosterone decreased (P < .001). Median IAF and SCF increased from 0 to 10 years (both P < .001). In multivariate analyses, change in oestrone positively correlated (P = .019) while change in testosterone (P = .003) and dihydrotestosterone (P = .014) negatively correlated with change in IAF. Plasma oestradiol and oestrone positively correlated with change in SCF (P = .041 and P = .030, respectively) while testosterone (P = .031) negatively correlated in multivariate analysis. CONCLUSION: Among 190 community-dwelling, Japanese American men, increases in IAF were associated with decreases in plasma androgens and increases in plasma oestrone, but not oestradiol, at 10 years. Further research is necessary to understand whether changing hormone concentrations are causally related to changes in regional adiposity or whether the reverse is true.

Disruption of TCF4 regulatory networks leads to abnormal cortical development and mental disabilities.

The TCF4 gene is the subject of numerous and varied investigations of it's role in the genesis of neuropsychiatric disease. The gene has been identified as the cause of Pitt-Hopkins syndrome (PTHS) and it has been implicated in various other neuropsychiatric diseases, including schizophrenia, depression, and autism. However, the precise molecular mechanisms of the gene's involvement in neurogenesis, particularly, corticogenesis, are not well understood. Here, we present data showing that TCF4 is expressed in a region-specific manner in the radial glia and stem cells of transient embryonic zones at early gestational ages in both humans and mice. TCF4 haploinsufficiency mice exhibit a delay in neuronal migration, and a significant increase in the number of upper-layer cortical neurons, as well as abnormal dendrite and synapse formation. Our research also reveals that TCF3 up-regulates Tcf4 by binding to the specific "E-box" and its flank sequence in intron 2 of the Tcf4 gene. Additionally, our transcriptome study substantiates that Tcf4 transcriptional function is essential for locomotion, cognition, and learning. By activating expression of TCF4 in the regulation of neuronal proliferation and migration to the overlaying neocortex and subsequent differentiation leading to laminar formation TCF4 fulfills its normal function, but if not, abnormalities such as those reported here result. These findings provide new insight into the specific roles of Tcf4 molecular pathway in neocortical development and their relevance in the pathogenesis of neuropsychiatric diseases.

Male Contraception.

Unintended pregnancy is a global public health problem. Despite a variety of female contraceptive options, male contraceptive options are limited to the condom and vasectomy. Condoms have high failure rates and surgical vasectomy is not reliably reversible. There is a global need and desire for novel male contraceptive methods. Hormonal methods have progressed the furthest in clinical development and androgen plus progestin formulations hold promise as a marketable, reversible male contraceptive over the next decade. Investigators have tested androgen plus progestin approaches using oral, transdermal, subdermal, and injectable drug formulations and demonstrated the short-term safety and reversibility of hormonal male contraception. The most commonly reported side effects associated with hormonal male contraception include weight gain, acne, slight suppression of serum high-density cholesterol, mood changes, and changes in libido. Efficacy trials of hormonal male contraceptives have demonstrated contraceptive efficacy rates greater than that of condoms. Although there has been less progression in the development of nonhormonal male contraceptives, potentially reversible vaso-occlusive methods are currently in clinical trials in some countries. Various studies have confirmed both men and women's desire for novel male contraceptives. Barriers to development include an absence of investment from pharmaceutical companies, concerns regarding side effects and spermatogenic rebound with hormonal methods, and lack of clear reversibility and proven effectiveness of nonhormonal methods. The ultimate availability of male contraceptives could have an important impact on decreasing global unintended pregnancy rates (currently 40% of all pregnancies) and will be a step towards reproductive justice and greater equity in family planning.

Comparative evaluation of the UMIC Colistine kit to assess MIC of colistin of gram-negative rods.

BACKGROUND: The recent description of the first plasmid-mediated colistin-resistant gene mcr-1, conferring transferable and low-level resistance to colistin, raised concern about the need to implement a rapid and reliable screening method to detect colistin-resistant clinical isolates. The only valid method to assess the MIC of colistin is the broth microdilution according to the joint CLSI-EUCAST Polymyxin Breakpoints Working Group. UMIC Colistine is a ready-to-use broth microdilution kit developed to easily assess colistin MIC by proposing unitary polystyrene strips containing 11 concentrations of dehydrated colistin. Here, we evaluated the UMIC Colistine kit on 235 Gram-negative rods (176 Enterobacterales, including 70 harboring a mcr gene, and 59 non-fermentative), through comparison to the reference broth microdilution method prepared in accordance with EN ISO 20776-1:2006 standard. Reproducibility of the UMIC Colistine was assayed with the three recommended quality control strains E. coli ATCC 25922, E. coli NCTC 13846 (mcr-1 positive), and P. aeruginosa ATCC 27853, as for stability testing. RESULTS: Categorical agreement was 100% with 63.4% (n = 149) of colistin-resistant strains, and 36.6% (n = 86) of colistin-susceptible strains with both methods (S ≤ 2 µg/mL and R > 2 µg/mL). No major error or very major error was reported. Essential agreement was 94.0% (n = 221), and 100% for detection of colistin-resistant strains as compared to the reference method. Pearson's correlation between UMIC Colistine and the reference method was 0.98. Reproducibility of the UMIC Colistine system was 97.8% with MICs of the quality control strains within the target ranges. However, some isolates had lower MIC with UMIC Colistine, but that did not change their categorization as colistin-susceptible, and this phenomenon should be further explored. CONCLUSIONS: The UMIC Colistine kit is an easy to perform unitary device that showed excellent results when compared to the reference method. The UMIC Colistine system is a rapid and reliable broth microdilution method that is suitable to assess the colistin MIC of clinical isolates in clinical microbiology laboratories.

No global increase in resistance to antibiotics: a snapshot of resistance from 2001 to 2016 in Marseille, France.

Since effective empirical antibiotic therapy is a key factor for survival, local antibiotic resistance epidemiology is critical. We aimed to identify current trends in antibiotic resistance for key antibiotics obtained over 16 years (2001-2016) for invasive infections corresponding to empirical treatment in a large hospital centre in Marseille, France.From January 2014 to December 2016, we have collected all data on antibiotic susceptibility from public laboratory hospitals, and a retrospective analysis was performed on key antibiotics in blood cultures since 2001. A total of 99,932 antibiotic susceptibility testings (ASTs) were analysed, and proportion of pan-drug resistant (PDR = resistant to all antibiotics tested) and extensively drug-resistant (XDR = resistant to all except for two classes) strains were < 0.03 and 0.5%, respectively. Between 2001 and 2016, we found an increase of resistance to third-generation cephalosporins for E. coli invasive strains (0% vs 17.8%; p < 10-5) and K. pneumoniae (8% vs 35.4%; p = 0.001) along with a decrease of methicillin-resistant S. aureus strains (31% vs 19.8%; p = 0.006). Moreover, during the 3-year period, a significant increase of wild-type strains, susceptible to all antibiotics tested, was observed in invasive infections. Regarding bacteraemia involving Enterobacteriaceae and S. aureus, empirical therapy is effective in > 99% cases. Active epidemiological surveillance is necessary because antibiotic resistance remains unpredictable.

The Intellectual Disability and Schizophrenia Associated Transcription Factor TCF4 Is Regulated by Neuronal Activity and Protein Kinase A.

Transcription factor 4 (TCF4 also known as ITF2 or E2-2) is a basic helix-loop-helix (bHLH) protein associated with Pitt-Hopkins syndrome, intellectual disability, and schizophrenia (SCZ). Here, we show that TCF4-dependent transcription in cortical neurons cultured from embryonic rats of both sexes is induced by neuronal activity via soluble adenylyl cyclase and protein kinase A (PKA) signaling. PKA phosphorylates TCF4 directly and a PKA phosphorylation site in TCF4 is necessary for its transcriptional activity in cultured neurons and in the developing brain in vivo We also demonstrate that Gadd45g (growth arrest and DNA damage inducible gamma) is a direct target of neuronal-activity-induced, TCF4-dependent transcriptional regulation and that TCF4 missense variations identified in SCZ patients alter the transcriptional activity of TCF4 in neurons. This study identifies a new role for TCF4 as a neuronal-activity-regulated transcription factor, offering a novel perspective on the association of TCF4 with cognitive disorders.SIGNIFICANCE STATEMENT The importance of the basic helix-loop-helix transcription factor transcription factor 4 (TCF4) in the nervous system is underlined by its association with common and rare cognitive disorders. In the current study, we show that TCF4-controlled transcription in primary cortical neurons is induced by neuronal activity and protein kinase A. Our results support the hypotheses that dysregulation of neuronal-activity-dependent signaling plays a significant part in the etiology of neuropsychiatric and neurodevelopmental disorders.

Circulating sex steroids coregulate adipose tissue immune cell populations in healthy men.

Male hypogonadism results in changes in body composition characterized by increases in fat mass. Resident immune cells influence energy metabolism in adipose tissue and could promote increased adiposity through paracrine effects. We hypothesized that manipulation of circulating sex steroid levels in healthy men would alter adipose tissue immune cell populations. Subjects (n = 44 men, 19-55 yr of age) received 4 wk of treatment with the gonadotropin-releasing hormone receptor antagonist acyline with daily administration of 1) placebo gel, 2) 1.25 g testosterone gel (1.62%), 3) 5 g testosterone gel, or 4) 5 g testosterone gel with an aromatase inhibitor. Subcutaneous adipose tissue biopsies were performed at baseline and end-of-treatment, and adipose tissue immune cells, gene expression, and intra-adipose estrogen levels were quantified. Change in serum total testosterone level correlated inversely with change in the number of CD3+ (ß = -0.36, P = 0.04), CD4+ (ß = -0.34, P = 0.04), and CD8+ (ß = -0.33, P = 0.05) T cells within adipose tissue. Change in serum 17ß-estradiol level correlated inversely with change in the number of adipose tissue macrophages (ATMs) (ß = -0.34, P = 0.05). A negative association also was found between change in serum testosterone and change in CD11c+ ATMs (ß = -0.41, P = 0.01). Overall, sex steroid deprivation was associated with increases in adipose tissue T cells and ATMs. No associations were found between changes in serum sex steroid levels and changes in adipose tissue gene expression. Circulating sex steroid levels may regulate adipose tissue immune cell populations. These exploratory findings highlight a possible novel mechanism that could contribute to increased metabolic risk in hypogonadal men.

LBJMR medium: a new polyvalent culture medium for isolating and selecting vancomycin and colistin-resistant bacteria.

BACKGROUND: Multi-drug resistant bacteria are a phenomenon which is on the increase around the world, particularly with the emergence of colistin-resistant Enterobacteriaceae and vancomycin-resistant enterococci strains. The recent discovery of a plasmid-mediated colistin resistance with the description of the transferable mcr-1 gene raised concerns about the need for an efficient detection method for these pathogens, to isolate infected patients as early as possible. The LBJMR medium was developed to screen for all polymyxin-resistant Gram-negative bacteria, including mcr-1 positive isolates, and vancomycin-resistant Gram-positive bacteria. RESULTS: The LBJMR medium was developed by adding colistin sulfate salt at a low concentration (4 µg/mL) and vancomycin (50 µg/mL), with glucose (7.5 g/L) as a fermentative substrate, to a Purple Agar Base (31 g/L). A total of 143 bacterial strains were used to evaluate this universal culture medium, and the sensitivity and specificity of detection were 100% for the growth of resistant strains. 68 stool samples were cultured on LBJMR, and both colistin-resistant Gram-negative and vancomycin-resistant Gram-positive strains were specifically detected. CONCLUSIONS: The LBJMR medium is a multipurpose selective medium which makes it possible to identify bacteria of interest from clinical samples and to isolate contaminated patients in hospital settings. This is a simple medium that could be easily used for screening in clinical microbiology laboratories.

Dose-response effects of sex hormone concentrations on body composition and adipokines in medically castrated healthy men administered graded doses of testosterone gel.

OBJECTIVE: Serum sex steroid concentrations may alter body composition and glucose homoeostasis in men in a dose-response manner. We evaluated these end-points in healthy men rendered medically castrate through use of a gonadotrophin-releasing hormone antagonist (acyline) with incremental doses of exogenous testosterone (T) gel. DESIGN: Subjects (n=6-9 per group) were randomly assigned to injections of acyline every 2 weeks plus transdermal T gel (1.25 g, 2.5 g, 5.0 g, 10 g or 15 g) daily or double placebo (injections and gel) for 12 weeks. PATIENTS: Healthy men, ages 25-55 years, with normal serum total T concentrations. MEASUREMENTS: Serum T, dihydrotestosterone (DHT) and oestradiol (E2) were measured at baseline and every 2 weeks. Body composition was analysed by dual-energy X-ray absorptiometry at baseline and week 12. Fasting serum adiponectin, leptin, glucose and insulin concentrations were measured at baseline and week 10. RESULTS: Forty-eight men completed the study. A significant treatment effect was observed for change in lean mass (ANOVAP=.01) but not fat mass (P=.14). Lean mass increased in the 15 g T group relative to all lower dose groups, except the 10 g T group. When all subjects were analysed together, changes in lean mass correlated directly and changes in fat mass correlated inversely with serum T, E2 and DHT. No changes were noted in serum glucose, insulin or adipokine levels. CONCLUSIONS: In healthy men, higher serum concentrations of T, DHT and E2 were associated with greater increases in lean mass and decreases in fat mass but not with changes in serum glucose, insulin or adipokines.

Evaluation of the Scan® 1200 as a rapid tool for reading antibiotic susceptibility testing by the disc diffusion technique.

OBJECTIVES: In clinical microbiology, some instruments are able to automatically read inhibition zone diameters for antibiotic susceptibility testing (AST) performed by the disc diffusion (DD) method. The actual resolution of commercial reader systems is low and high-resolution scanners have been developed for microbiology. Here, we evaluated and compared the reading and interpretation of AST by the DD method using the Scan® 1200 instrument as compared with the Sirscan® system on 211 clinical strains and the possibility to read AST after 6 or 8 h of incubation as compared with 24 h on 121 additional Gram-negative strains and 76 non-fermenter Gram-negative and Gram-positive strains. METHODS: Validation of the technique was assessed on three reference strains as requested by EUCAST for analysis of the repeatability and reproducibility of the method. RESULTS: Correlation between the two methods, assessed using 211 clinical isolates (n = 2439 zones of growth inhibition measured), was excellent with a correlation coefficient of 0.97. For the earlier reading experiments, preliminary results demonstrate the possibility of reading AST for drug-species combinations after 6 and 8 h for Gram-negative bacteria with rapid growth (correlation coefficient at 6 h = 0.96 and at 8 h = 0.98) and at 8 or 10 h for Gram-positive bacteria. CONCLUSIONS: The Scan® 1200 has many advantages thanks to its small size, rapidity of use and high-resolution imaging allowing the possibility to improve AST results after only 6-8 h of incubation. This AST reader system represents a robust alternative tool for routine use in clinical microbiology laboratories.

The association of obesity with sex hormone-binding globulin is stronger than the association with ageing--implications for the interpretation of total testosterone measurements.

OBJECTIVE: Total testosterone concentrations are influenced by sex hormone-binding globulin (SHBG) concentrations, which are decreased by obesity and increased with ageing. Therefore, we sought to understand and compare the associations of ageing and obesity with SHBG. DESIGN: We performed a retrospective, cross-sectional analysis of the associations of obesity and age on SHBG and testosterone measurements in men being evaluated for hypogonadism. PATIENTS, MEASUREMENTS AND ANALYSIS: A total of 3671 men who underwent laboratory testing for testosterone deficiency from the Veterans Administration Puget Sound Health Care System from 1997 through 2007 was included. Univariate and multivariate linear regression modelling of the associations between age and body mass index (BMI) and SHBG was performed. RESULTS: Obesity was associated with a significantly lower SHBG [ß = -1·26 (95% CI -1·14, -1·38) nmol/l] per unit increase in BMI. In contrast, ageing was associated with a significantly increased SHBG [ß = 0·46 (95% CI 0·39, 0·53) nmol/l per year] (P < 0·001 for both effects). The association of obesity with lower SHBG was two to three times larger than the association of ageing with increased SHBG in both univariate and multivariate modelling. On average, obese men (BMI >30 kg/m(2)) had significantly lower SHBG and total testosterone concentrations than nonobese men [(mean ± SD) SHBG: 36 ± 22 vs 50 ± 27 nmol/l and total testosterone: 10·5 ± 5·4 nmol/l vs 14·1 ± 7·4 nmol/l; (P < 0·001 for both comparisons)], but calculated free testosterone concentrations did not differ between obese and nonobese men. CONCLUSIONS: We found that the association between obesity and lowered SHBG is greater than the association of ageing with increased SHBG. These competing effects may impact total testosterone measurements for the diagnosis of low testosterone, particularly in obese men.