The pattern of structural brain alterations associated with major depressive disorder (MDD) remains unresolved. This is in part due to small sample sizes of neuroimaging studies resulting in limited ...statistical power, disease heterogeneity and the complex interactions between clinical characteristics and brain morphology. To address this, we meta-analyzed three-dimensional brain magnetic resonance imaging data from 1728 MDD patients and 7199 controls from 15 research samples worldwide, to identify subcortical brain volumes that robustly discriminate MDD patients from healthy controls. Relative to controls, patients had significantly lower hippocampal volumes (Cohen's d=-0.14, % difference=-1.24). This effect was driven by patients with recurrent MDD (Cohen's d=-0.17, % difference=-1.44), and we detected no differences between first episode patients and controls. Age of onset ⩽21 was associated with a smaller hippocampus (Cohen's d=-0.20, % difference=-1.85) and a trend toward smaller amygdala (Cohen's d=-0.11, % difference=-1.23) and larger lateral ventricles (Cohen's d=0.12, % difference=5.11). Symptom severity at study inclusion was not associated with any regional brain volumes. Sample characteristics such as mean age, proportion of antidepressant users and proportion of remitted patients, and methodological characteristics did not significantly moderate alterations in brain volumes in MDD. Samples with a higher proportion of antipsychotic medication users showed larger caudate volumes in MDD patients compared with controls. This currently largest worldwide effort to identify subcortical brain alterations showed robust smaller hippocampal volumes in MDD patients, moderated by age of onset and first episode versus recurrent episode status.
Summary
Background
Azathioprine (AZA)‐induced pancreatitis is an unpredictable and dose‐independent adverse event affecting 2%‐7% of patients with inflammatory bowel disease (IBD) patients treated ...with AZA. There are no tools in clinical practice to identify at‐risk individuals; however, a genome wide association study (GWAS) identified a strong association between the Class II HLA gene region polymorphism (rs2647087) and thiopurine‐induced pancreatitis.
Aim
To independently confirm the findings of the GWAS in an IBD cohort, to evaluate its utility in clinical practice and to offer a novel AZA treatment algorithm for IBD based on pharmacogenomic principles.
Methods
A retrospective cohort study evaluated 373 AZA‐exposed IBD patients from a tertiary care academic centre in London, Canada. Due to the limited number of patients taking mercaptopurine (MP), such patients were not included this cohort. All subjects underwent screening for the single nucleotide polymorphism (SNP) rs2647087 mapped to the HLA‐DQA1*02:01‐HLA‐DRB1*07:01 haplotype and were sub‐divided based on the presence (n = 13) or absence (n = 360) of an AZA‐induced pancreatitis diagnosis. The risk of AZA‐induced pancreatitis was assessed based on rs2647087 genotype.
Results
The risk of pancreatitis during AZA‐therapy was highly predictable and genotype dependent: 0.53% for wild type (A/A), 4.25% (OR = 4.19, 95% CI 1.02‐36.45, P = 0.044) for heterozygous (A/C), and 14.63% (OR = 15.83, 95% CI 3.80‐145.26, P = 0.0001) for homozygous variant (C/C) patients.
Conclusions
The class II HLA region (at rs2647087) is an important marker of AZA‐induced pancreatitis risk. We propose a simple and clinically implementable algorithm based on rs2647087 and TPMT genotypes for AZA selection and dosing for patients with IBD.
Linked ContentThis article is linked to Teich et al and Wilson et al papers. To view these articles visit https://doi.org/10.1111/apt.14545 and https://doi.org/10.1111/apt.14562.
Background. Previous observational studies found highly active antiretroviral therapy (HAART) to be associated with improved survival among human immunodeficiency virus (HIV)– infected children and ...adolescents. However, these studies had limited follow-up of HIV-infected children undergoing HAART. Given that HIV infection is chronic and that exposure to HAART is likely to be life-long, there is a need to evaluate the long-term effect of HAART on survival in this population. Methods. The study included 1236 children and adolescents who were perinatally infected with HIV, who were on study or enrolled after January 1996 in a United States-based multicenter prospective cohort study (Pediatric AIDS Clinical Trials Group 219/219C), and who were not receiving HAART at baseline; subjects were observed for a maximum of 10 years through June 2006. A weighted Cox regression model was used to estimate the effect of HAART on survival, appropriately adjusted for time-varying confounding by severity. Results. At the end of the 10-year follow-up period (median duration of follow-up, 6.3 years; interquartile range, 4.3– 9.8 years), 70% of participants had initiated HAART. Lower CD4 cell percentages, total lymphocyte counts, and albumin levels were associated with an increased probability of initiating HAART. Eighty-five deaths were observed, and the mortality hazard ratio associated with HAART, compared with non-HAART regimens, was 0.24 after adjusting for measured confounding by severity (95% confidence interval, 0.11– 0.51). Conclusions. The use of HAART was highly effective in reducing mortality during the period 1996– 2006 among children and adolescents infected with HIV. With improved long-term survival, continued follow-up is necessary to evaluate the effects of prolonged use of HAART on potential adverse events, immune function, growth, sexual maturation, and quality of life in this population.
Poly(ethylene glycol) (PEG)-mediated fusion of phosphatidylcholine model membranes has been shown to mimic the protein-mediated biomembrane process Lee, J., and Lentz, B. R. (1998) Proc. Natl. Acad. ...Sci. U.S.A. 95, 9274−9279. Unlike the simple model membranes used in this earlier study, the lipid composition of fusogenic biomembranes is quite complex. The purpose of this paper was to examine PEG-mediated fusion of highly curved (SUV) and largely uncurved (LUV) membrane vesicles composed of different lipids in order to identify lipid compositions that produce highly fusogenic membranes. Starting with liposomes composed of five lipids with different physical properties, dioleoylphosphatidylcholine (DOPC), dioleoylphosphatidylethanolamine (DOPE), dioleoylphosphatidylserine (DOPS), bovine brain sphingomyelin (SM), and cholesterol (CH), we systematically varied the composition and tested for the extent of PEG-mediated fusion after 5 min of treatment. We found that a vesicle system composed of four lipids, DOPC/DOPE/SM/CH, fused optimally at a 35/30/15/20 molar ratio. Each lipid seemed to play a part in optimizing the membrane for fusion. PE disrupted outer leaflet packing as demonstrated with TMA-DPH lifetime, C6-NBD-PC partitioning, and DPH anisotropy measurements, and thus significantly enhanced fusion and rupture, without significantly altering interbilayer approach (X-ray diffraction). An optimal ratio of PC/PE (35/30) produced a balance between fusion and rupture. CH and SM, when present at an optimal ratio of 3/4 in vesicles containing the optimal PC/PE ratio, reduced rupture without significantly reducing fusion. This optimal CH/SM ratio also enhanced outer leaflet packing, suggesting that fusion is dependent not only on outer leaflet packing but also on the properties of the inner leaflet. Addition of CH without SM enhanced rupture relative to fusion, while SM alone reduced both rupture and fusion. The optimal lipid composition is very close to the natural synaptic vesicle composition, suggesting that the synaptic vesicle composition is optimized with respect to fusogenicity.
Di-(2-ethylhexyl) phthalate (DEHP) is used industrially to add flexibility to polyvinyl chloride (PVC) polymers and is ubiquitously found in the environment, with evidence of prenatal, perinatal and ...early infant exposure in humans. In utero exposure to DEHP decreases circulating testosterone levels in the adult rat. In addition, DEHP reduces the expression of the angiotensin II receptors in the adrenal gland, resulting in decreased circulating aldosterone levels. The latter may have important effects on water and electrolyte balance as well as systemic arterial blood pressure. Therefore, we determined the effects of in utero exposure to DEHP on systemic arterial blood pressure in the young (2month-old) and older (6.5month-old) adult rats. Sprague-Dawley pregnant dams were exposed from gestational day 14 until birth to 300mg DEHP/kg/day. Blood pressure, heart rate, and activity data were collected using an intra-aortal transmitter in the male offspring at postnatal day (PND) 60 and PND200. A low (0.01%) and high-salt (8%) diet was used to challenge the animals at PND200. In utero exposure to DEHP resulted in reduced activity at PND60. At PND200, systolic and diastolic systemic arterial pressures as well as activity were reduced in response to DEHP exposure. This is the first evidence showing that in utero exposure to DEHP has cardiovascular and behavioral effects in the adult male offspring.
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► In utero exposure to 300mg DEHP/kg/day decreases activity at postnatal day 60. ► In utero exposure to DEHP decreases aldosterone levels at postnatal day 200. ► In utero exposure to DEHP decreases systolic blood pressure at postnatal day 200. ► An 8% salt diet recovers the decreased blood pressure at postnatal day 200.
Abstract We used a probabilistic reversal learning task to examine prediction error-driven belief updating in three clinical groups with psychosis or psychosis-like symptoms. Study 1 compared people ...with at-risk mental state and first episode psychosis (FEP) to matched controls. Study 2 compared people diagnosed with treatment-resistant schizophrenia (TRS) to matched controls. The design replicated our previous work showing ketamine-related perturbations in how meta-level confidence maintained behavioural policy. We applied the same computational modelling analysis here, in order to compare the pharmacological model to three groups at different stages of psychosis. Accuracy was reduced in FEP, reflecting increased tendencies to shift strategy following probabilistic errors. The TRS group also showed a greater tendency to shift choice strategies though accuracy levels were not significantly reduced. Applying the previously-used computational modelling approach, we observed that only the TRS group showed altered confidence-based modulation of responding, previously observed under ketamine administration. Overall, our behavioural findings demonstrated resemblance between clinical groups (FEP and TRS) and ketamine in terms of a reduction in stabilisation of responding in a noisy environment. The computational analysis suggested that TRS, but not FEP, replicates ketamine effects but we consider the computational findings preliminary given limitations in performance of the model.
Linked ContentThis article is linked to Wilson et al and Teich et al papers. To view these articles visit https://doi.org/10.1111/apt.14483 and https://doi.org/10.1111/apt.14545.
The cycle of spindle pole body (SPB) duplication, differentiation, and segregation in Schizosaccharomyces pombe is different from that in some other yeasts. Like the centrosome of vertebrate cells, ...the SPB of S. pombe spends most of interphase in the cytoplasm, immediately next to the nuclear envelope. Some gamma-tubulin is localized on the SPB, suggesting that it plays a role in the organization of interphase microtubules (MTs), and serial sections demonstrate that some interphase MTs end on or very near to the SPB. gamma-Tubulin is also found on osmiophilic material that lies near the inner surface of the nuclear envelope, immediately adjacent to the SPB, even though there are no MTs in the interphase nucleus. Apparently, the MT initiation activities of gamma-tubulin in S. pombe are regulated. The SPB duplicates in the cytoplasm during late G2 phase, and the two resulting structures are connected by a darkly staining bridge until the mitotic spindle forms. As the cell enters mitosis, the nuclear envelope invaginates beside the SPB, forming a pocket of cytoplasm that accumulates dark amorphous material. The nuclear envelope then opens to form a fenestra, and the duplicated SPB settles into it. Each part of the SPB initiates intranuclear MTs, and then the two structures separate to lie in distinct fenestrae as a bipolar spindle forms. Through metaphase, the SPBs remain in their fenestrae, bound to the polar ends of spindle MTs; at about this time, a small bundle of cytoplasmic MTs forms in association with each SPB. These MTs are situated with one end near to, but not on, the SPBs, and they project into the cytoplasm at an orientation that is oblique to the simple axis. As anaphase proceeds, the nuclear fenestrae close, and the SPBs are extruded back into the cytoplasm. These observations define new fields of enquiry about the control of SPB duplication and the dynamics of the nuclear envelope.
Most of the >50 000 different pharmacologically active peptides in Conus venoms belong to a small number of gene superfamilies. In this work, the M-conotoxin superfamily is defined using both ...biochemical and molecular criteria. Novel excitatory peptides purified from the venoms of the molluscivorous species Conus textile and Conus marmoreus all have a characteristic pattern of Cys residues previously found in the μ-, κM-, and ψ-conotoxins (CC−C−C−CC). The new peptides are smaller (12−19 amino acids) than the μ-, κM-, and ψ-conotoxins (22−24 amino acids). One peptide, mr3a, was chemically synthesized in a biologically active form. Analysis of the disulfide bridges of a natural peptide tx3c from C. textile and synthetic peptide mr3a from C. marmoreus showed a novel pattern of disulfide connectivity, different from that previously established for the μ- and ψ-conotoxins. Thus, these peptides belong to a new group of structurally and pharmacologically distinct conotoxins that are particularly prominent in the venoms of mollusc-hunting Conus species. Analysis of cDNA clones encoding the novel peptides as well as those encoding μ-, κM-, and ψ-conotoxins revealed highly conserved amino acid residues in the precursor sequences; this conservation in both amino acid sequence and in the Cys pattern defines a gene superfamily, designated the M-conotoxin superfamily. The peptides characterized can be provisionally assigned to four distinct groups within the M-superfamily based on sequence similarity within and divergence between each group. A notable feature of the superfamily is that two distinct structural frameworks have been generated by changing the disulfide connectivity on an otherwise conserved Cys pattern.
When treating individual patients, physicians may face difficulties using the evidence from center-based randomized control trials (RCTs) due to limitations in these studies' generalizability. ...Therefore, they often perform their own “informal” tests of treatment effectiveness. Single patient (“N-of-1”) trials provide a structured design for more rigorous assessment of medical treatments of chronic diseases, but are applied only to the index patient. We present a hierarchical Bayesian random effects model to combine N-of-1 studies to obtain an estimate of treatment effectiveness for the population and to use this population information to aid in the evaluation of an individual patient's trial results. The model's treatment effect estimates are adjustments between the population estimate and the individual's observed results. This adjustment is based upon the within-patient and between-patient heterogeneity. We demonstrate this patient-focused method using published data from 23 N-of-1 trial results comparing amitriptyline and placebo for the treatment of fibromyalgia.
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