Androgens and spermatogenesis: lessons from transgenic mouse models

Transgenic mouse models have contributed considerably to our understanding of the cellular and molecular mechanisms by which androgens control spermatogenesis. Cell-selective ablation of the androgen receptor (AR) in Sertoli cells (SC) results in a complete block in meiosis and unambiguously identifies the SC as the main cellular mediator of the effects of androgens on spermatogenesis. This conclusion is corroborated by similar knockouts in other potential testicular target cells. Mutations resulting in diminished expression of the AR or in alleles with increased length of the CAG repeat mimick specific human forms of disturbed fertility that are not accompanied by defects in male sexual development. Transcriptional profiling studies in mice with cell-selective and general knockouts of the AR, searching for androgen-regulated genes relevant to the control of spermatogenesis, have identified many candidate target genes. However, with the exception of Rhox5, the identified subsets of genes show little overlap. Genes related to tubular restructuring, cell junction dynamics, the cytoskeleton, solute transportation and vitamin A metabolism are prominently present. Further research will be needed to decide which of these genes are physiologically relevant and to identify genes that can be used as diagnostic tools or targets to modulate the effects of androgens in spermatogenesis

Methotrexate safety and efficacy in combination therapies in patients with early rheumatoid arthritis : a post-hoc analysis of a randomized controlled trial (NORD-STAR)

This article is protected by copyright. All rights reserved.OBJECTIVE: To investigate methotrexate safety and influence of dose on efficacy outcomes in combination with three different biological treatments and with active conventional treatment (ACT) in early rheumatoid arthritis (RA). METHODS: This post-hoc analysis included 812 treatment-naïve early RA patients who were randomized (1:1:1:1) in the NORD-STAR trial (NCT01491815) to receive methotrexate in combination with ACT, certolizumab-pegol, abatacept, or tocilizumab. Methotrexate safety, doses, and dose effects on Clinical Disease Activity Index (CDAI) remission were assessed after 24 weeks of treatment. RESULTS: Compared with ACT, the prevalence of methotrexate-associated side effects was higher when methotrexate was combined with tocilizumab (HR 1.48 [95% CI 1.20 to 1.84]), but not with certolizumab-pegol (HR 0.99 [0.79 to 1.23]) or with abatacept (HR 0.93 [0.75 to 1.16]). With ACT as the reference, methotrexate dose was significantly lower when used in combination with tocilizumab (β -4.65 [95% CI -5.83 to -3.46], p<0.001), with abatacept (β -1.15 [-2.27 to -0.03], p=0.04), and numerically lower in combination with certolizumab-pegol (β -1.07 [-2.21 to 0.07], p=0.07). Methotrexate dose reductions were not associated with decreased CDAI remission rates within any of the treatment combinations. CONCLUSION: Methotrexate was generally well tolerated in combination therapies, but adverse events were a limiting factor in receiving the target dose of 25 mg/week, and these were more frequent in combination with tocilizumab versus active conventional treatment. On the other hand, methotrexate dose reductions were not associated with decreased CDAI remission rates within any of the four treatment combinations at 24 weeks. This article is protected by copyright. All rights reserved.Peer reviewe

Effects of age, BMI and sex on the glial cell marker TSPO - a multicentre [C-11]PBR28 HRRT PET study

Purpose The purpose of this study was to investigate the effects of ageing, sex and body mass index (BMI) on translocator protein (TSPO) availability in healthy subjects using positron emission tomography (PET) and the radioligand [C-11]PBR28. Methods [C-11]PBR28 data from 140 healthy volunteers (72 males and 68 females; N = 78 with HAB and N = 62 MAB genotype; age range 19-80 years; BMI range 17.6-36.9) were acquired with High Resolution Research Tomograph at three centres: Karolinska Institutet (N = 53), Turku PET centre (N = 62) and Yale University PET Center (N = 25). The total volume of distribution (V-T) was estimated in global grey matter, frontal, temporal, occipital and parietal cortices, hippocampus and thalamus using multilinear analysis 1. The effects of age, BMI and sex on TSPO availability were investigated using linear mixed effects model, with TSPO genotype and PET centre specified as random intercepts. Results There were significant positive correlations between age and V-T in the frontal and temporal cortex. BMI showed a significant negative correlation with V-T in all regions. Additionally, significant differences between males and females were observed in all regions, with females showing higher V-T. A subgroup analysis revealed a positive correlation between V-T and age in all regions in male subjects, whereas age showed no effect on TSPO levels in female subjects. Conclusion These findings provide evidence that individual biological properties may contribute significantly to the high variation shown in TSPO binding estimates, and suggest that age, BMI and sex can be confounding factors in clinical studies

Preoperative cerebrospinal fluid cytokine levels and the risk of postoperative delirium in elderly hip fracture patients

Aging and neurodegenerative disease predispose to delirium and are both associated with increased activity of the innate immune system resulting in an imbalance between pro- and anti-inflammatory mediators in the brain. We examined whether hip fracture patients who develop postoperative delirium have altered levels of inflammatory mediators in cerebrospinal fluid (CSF) prior to surgery. Patients were 75 years and older and admitted for surgical repair of an acute hip fracture. CSF samples were collected preoperatively. In an exploratory study, we measured 42 cytokines and chemokines by multiplex analysis. We compared CSF levels between patients with and without postoperative delirium and examined the association between CSF cytokine levels and delirium severity. Delirium was diagnosed with the Confusion Assessment Method; severity of delirium was measured with the Delirium Rating Scale Revised-98. Mann-Whitney U tests or Student t-tests were used for between-group comparisons and the Spearman correlation coefficient was used for correlation analyses. Sixty-one patients were included, of whom 23 patients (37.7%) developed postsurgical delirium. Concentrations of Fms-like tyrosine kinase-3 (P=0.021), Interleukin-1 receptor antagonist (P=0.032) and Interleukin-6 (P=0.005) were significantly lower in patients who developed delirium postoperatively. Our findings fit the hypothesis that delirium after surgery results from a dysfunctional neuroinflammatory response: stressing the role of reduced levels of anti-inflammatory mediators in this process. The Effect of Taurine on Morbidity and Mortality in the Elderly Hip Fracture Patient.Registration number: NCT00497978. Local ethical protocol number: NL16222.094.0