94 research outputs found
Environmental factors, not plants, contribute to functional diversity of soil bacteria in the dunes of lake michigan.
Soil bacteria play important roles in nutrient cycling and other ecosystem functions, and many biotic and abiotic factors can influence bacterial functional diversity. The goal of this field study was to examine differences among bacterial communities in sand dunes of Lake Michigan. I used Biolog Ecoplates™ to compare bacteria functional diversity associated with four different plant species: the native dune-building grass Ammophila breviligulata, invasive species Leymus arenarius and Gypsophila paniculata, and native legume Lathyrus japonicus across 13 sites in Michigan, representing a gradient in abiotic factors such as precipitation and temperature. I found no differences in bacterial function associated with plant species, but did find strong effects of precipitation, elevation, organic matter, plot distance from forest, and latitude. I conclude that abiotic and edaphic factors played a much larger role in shaping bacteria community function than changes in plant species
Pichia pastoris Fep1 is a [2Fe-2S] protein with a Zn finger that displays an unusual oxygen-dependent role in cluster binding
Fep1, the iron-responsive GATA factor from the methylotrophic yeast Pichia pastoris, has been characterised both in vivo and in vitro. This protein has two Cys(2)-Cys(2) type zinc fingers and a set of four conserved cysteines arranged in a Cys-X-5-Cys-X-8-Cys-X-2-Cys motif located between the two zinc fingers. Electronic absorption and resonance Raman spectroscopic analyses in anaerobic and aerobic conditions indicate that Fep1 binds iron in the form of a [2Fe-2S] cluster. Site-directed mutagenesis shows that replacement of the four cysteines with serine inactivates this transcriptional repressor. Unexpectedly, the inactive mutant is still able to bind a [2Fe-2S] cluster, employing two cysteine residues belonging to the first zinc finger. These two cysteine residues can act as alternative cluster ligands selectively in aerobically purified Fep1 wild type, suggesting that oxygen could play a role in Fep1 function by causing differential localization of the [Fe-S] cluster
Correction: A Guideline and Checklist for Initiating and Managing Clozapine Treatment in Patients with Treatment-Resistant Schizophrenia
This article was published online on June 27, 2022. An error was subsequently identified in the article, and the following correction should be noted: In the original publication, section 4.6, page 667, the reference cited in the first full sentence in column 2 and in Table 5 on the same page that read: “This information can be used to optimize clozapine dosage (Table 5) [103].” “Table 5 Therapeutic drug monitoring (TDM)-informed decision-making algorithm for clozapine-treated patientsa [103]” “Adapted by permission from reference [103]” Should read: “This information can be used to optimize clozapine dosage (Table 5) [104].” “Table 5 Therapeutic drug monitoring (TDM)-informed decision-making algorithm for clozapine-treated patientsa [104]” “Adapted by permission from reference [104]” The original article has been corrected. © The Author(s) 2022
A Guideline and Checklist for Initiating and Managing Clozapine Treatment in Patients with Treatment-Resistant Schizophrenia
Treatment-resistant schizophrenia (TRS) will affect about one in three patients with schizophrenia. Clozapine is the only treatment approved for TRS, and patients should be treated as soon as possible to improve their chances of achieving remission. Despite its effectiveness, concern over side effects, monitoring requirements, and inexperience with prescribing often result in long delays that can expose patients to unnecessary risks and compromise their chances of achieving favorable long-term outcomes. We critically reviewed the literature on clozapine use in TRS, focusing on guidelines, systematic reviews, and algorithms to identify strategies for improving clozapine safety and tolerability. Based on this, we have provided an overview of strategies to support early initiation of clozapine in patients with TRS based on the latest evidence and our clinical experience, and have summarized the key elements in a practical, evidence-based checklist for identifying and managing patients with TRS, with the aim of increasing confidence in prescribing and monitoring clozapine therapy
Multicentre analysis of incidental findings on low-resolution CT attenuation correction images : an extended study
Objective: To review new incidental findings detected
on low-resolution CT attenuation correction (CTAC)
images acquired during single-photon emission CT-CT
myocardial perfusion imaging as an extension to our
initial study.
Methods: CTAC images acquired as part of myocardial
perfusion imaging performed using single-photon emission
CT at four UK nuclear medicine centres were evaluated as
part of a multicentre study. New incidental findings that
were considered to be clinically significant were evaluated
further. Positive-predictive value (PPV) was determined at
the time of definitive diagnosis.
Results: Out of 3485 patients, 962 (28%) patients had
a positive finding on the CTAC image, of which 824 (24%)
were new findings. 84 (2.4%) patients had findings
that were considered clinically significant at the time of
the CTAC report and which had not been previously
diagnosed. However, only 10 (0.29%) of these had
findings that were confirmed as clinically significant, with
the potential to be detrimental to patient outcome, after
follow-up and definitive diagnosis.
Conclusion: The overall PPV from all centres over the
2-year period was 12%. Each centre achieved what we
considered to be low PPVs with no significant difference
between the present and initial studies. The additional
data from the combined studies show that, statistically,
there is no significant difference between the PPVs from
any of the centres. We conclude that routine reporting of
CTAC images is not beneficial.
Advances in knowledge: This study combined with the
previous study offers a unique evaluation of new clinically
significant incidental findings on low-resolution CT images
in an attempt to determine the benefit of reporting the
CTAC images
Comparative effects of 18 antipsychotics on metabolic function in patients with schizophrenia, predictors of metabolic dysregulation, and association with psychopathology: a systematic review and network meta-analysis.
BACKGROUND
Antipsychotic treatment is associated with metabolic disturbance. However, the degree to which metabolic alterations occur in treatment with different antipsychotics is unclear. Predictors of metabolic dysregulation are poorly understood and the association between metabolic change and change in psychopathology is uncertain. We aimed to compare and rank antipsychotics on the basis of their metabolic side-effects, identify physiological and demographic predictors of antipsychotic-induced metabolic dysregulation, and investigate the relationship between change in psychotic symptoms and change in metabolic parameters with antipsychotic treatment.
METHODS
We searched MEDLINE, EMBASE, and PsycINFO from inception until June 30, 2019. We included blinded, randomised controlled trials comparing 18 antipsychotics and placebo in acute treatment of schizophrenia. We did frequentist random-effects network meta-analyses to investigate treatment-induced changes in body weight, BMI, total cholesterol, LDL cholesterol, HDL cholesterol, triglyceride, and glucose concentrations. We did meta-regressions to examine relationships between metabolic change and age, sex, ethnicity, baseline weight, and baseline metabolic parameter level. We examined the association between metabolic change and psychopathology change by estimating the correlation between symptom severity change and metabolic parameter change.
FINDINGS
Of 6532 citations, we included 100 randomised controlled trials, including 25 952 patients. Median treatment duration was 6 weeks (IQR 6-8). Mean differences for weight gain compared with placebo ranged from -0·23 kg (95% CI -0·83 to 0·36) for haloperidol to 3·01 kg (1·78 to 4·24) for clozapine; for BMI from -0·25 kg/m2 (-0·68 to 0·17) for haloperidol to 1·07 kg/m2 (0·90 to 1·25) for olanzapine; for total-cholesterol from -0·09 mmol/L (-0·24 to 0·07) for cariprazine to 0·56 mmol/L (0·26-0·86) for clozapine; for LDL cholesterol from -0·13 mmol/L (-0.21 to -0·05) for cariprazine to 0·20 mmol/L (0·14 to 0·26) for olanzapine; for HDL cholesterol from 0·05 mmol/L (0·00 to 0·10) for brexpiprazole to -0·10 mmol/L (-0·33 to 0·14) for amisulpride; for triglycerides from -0·01 mmol/L (-0·10 to 0·08) for brexpiprazole to 0·98 mmol/L (0·48 to 1·49) for clozapine; for glucose from -0·29 mmol/L (-0·55 to -0·03) for lurasidone to 1·05 mmol/L (0·41 to 1·70) for clozapine. Greater increases in glucose were predicted by higher baseline weight (p=0·0015) and male sex (p=0·0082). Non-white ethnicity was associated with greater increases in total cholesterol (p=0·040) compared with white ethnicity. Improvements in symptom severity were associated with increases in weight (r=0·36, p=0·0021), BMI (r=0·84, p<0·0001), total-cholesterol (r=0·31, p=0·047), and LDL cholesterol (r=0·42, p=0·013), and decreases in HDL cholesterol (r=-0·35, p=0·035).
INTERPRETATION
Marked differences exist between antipsychotics in terms of metabolic side-effects, with olanzapine and clozapine exhibiting the worst profiles and aripiprazole, brexpiprazole, cariprazine, lurasidone, and ziprasidone the most benign profiles. Increased baseline weight, male sex, and non-white ethnicity are predictors of susceptibility to antipsychotic-induced metabolic change, and improvements in psychopathology are associated with metabolic disturbance. Treatment guidelines should be updated to reflect our findings. However, the choice of antipsychotic should be made on an individual basis, considering the clinical circumstances and preferences of patients, carers, and clinicians.
FUNDING
UK Medical Research Council, Wellcome Trust, National Institute for Health Research Oxford Health Biomedical Research Centre
Parsing neurobiological heterogeneity of the clinical high-risk state for psychosis: A pseudo-continuous arterial spin labelling study
The impact of the clinical high-risk for psychosis (CHR-P) construct is dependent on accurately predicting outcomes. Individuals with brief limited intermittent psychotic symptoms (BLIPS) have higher risk of developing a first episode of psychosis (FEP) compared to individuals with attenuated psychotic symptoms (APS). Supplementing subgroup stratification with information from candidate biomarkers based on neurobiological parameters, such as resting-state, regional cerebral blood flow (rCBF), may help refine risk estimates. Based on previous evidence, we hypothesised that individuals with BLIPS would exhibit increased rCBF compared to APS in key regions linked to dopaminergic pathways. Data from four studies were combined using ComBat (to account for between-study differences) to analyse rCBF in 150 age- and sex-matched subjects (n=30 healthy controls [HCs], n=80 APS, n=20 BLIPS and n=20 FEP). Global grey matter (GM) rCBF was examined in addition to region-of-interest (ROI) analyses in bilateral/left/right frontal cortex, hippocampus and striatum. Group differences were assessed using general linear models: i) alone; ii) with global GM rCBF as a covariate; iii) with global GM rCBF and smoking status as covariates. Significance was set at pNo significant group differences were found in global (F(3,143)=1,41, p=0.24), bilateral frontal cortex (F(3,143)=1.01, p=0.39), hippocampus (F(3,143)=0.63, p=0.60) or striatum (F(3,143)=0.52, p=0.57) rCBF. Similar null findings were observed in lateralised ROIs (p>0.05). All results were robust to addition of covariates (p>0.05). No significant clusters were identified in whole-brain voxel-wise analyses (p>0.05FWE). Weak-to-moderate evidence was found for an absence of rCBF differences between APS and BLIPS in Bayesian ROI analyses.On this evidence, APS and BLIPS are unlikely to be neurobiologically distinct. Due to this and the weak-to-moderate evidence for the null hypothesis, future research should investigate larger samples of APS and BLIPS through collaboration across large-scale international consortia.<br/
Netazepide inhibits expression of Pappalysin 2 in type-1 gastric neuroendocrine tumors
Background & Aims: In patients with autoimmune atrophic gastritis and achlorhydria, hypergastrinemia is associated with the development of type 1 gastric neuroendocrine tumors (gNETs). Twelve months of treatment with netazepide (YF476), an antagonist of the cholecystokinin B receptor (CCKBR or CCK2R), eradicated some type 1 gNETs in patients. We investigated the mechanisms by which netazepide induced gNET regression using gene expression profiling. Methods: We obtained serum samples and gastric corpus biopsy specimens from 8 patients with hypergastrinemia and type 1 gNETs enrolled in a phase 2 trial of netazepide. Control samples were obtained from 10 patients without gastric cancer. We used amplified and biotinylated sense-strand DNA targets from total RNA and Affymetrix (Thermofisher Scientific, UK) Human Gene 2.0 ST microarrays to identify differentially expressed genes in stomach tissues from patients with type 1 gNETs before, during, and after netazepide treatment. Findings were validated in a human AGS GR gastric adenocarcinoma cell line that stably expresses human CCK2R, primary mouse gastroids, transgenic hypergastrinemic INS-GAS mice, and patient samples. Results: Levels of pappalysin 2 (PAPPA2) messenger RNA were reduced significantly in gNET tissues from patients receiving netazepide therapy compared with tissues collected before therapy. PAPPA2 is a metalloproteinase that increases the bioavailability of insulin-like growth factor (IGF) by cleaving IGF binding proteins (IGFBPs). PAPPA2 expression was increased in the gastric corpus of patients with type 1 gNETs, and immunohistochemistry showed localization in the same vicinity as CCK2R-expressing enterochromaffin-like cells. Up-regulation of PAPPA2 also was found in the stomachs of INS-GAS mice. Gastrin increased PAPPA2 expression with time and in a dose-dependent manner in gastric AGS GR cells and mouse gastroids by activating CCK2R. Knockdown of PAPPA2 in AGS GR cells with small interfering RNAs significantly decreased their migratory response and tissue remodeling in response to gastrin. Gastrin altered the expression and cleavage of IGFBP3 and IGFBP5. Conclusions: In an analysis of human gNETS and mice, we found that gastrin up-regulates the expression of gastric PAPPA2. Increased PAPPA2 alters IGF bioavailability, cell migration, and tissue remodeling, which are involved in type 1 gNET development. These effects are inhibited by netazepide
Trace amine-associated receptor 1 (TAAR1) agonists for psychosis: protocol for a living systematic review and meta-analysis of human and non-human studies
Background: There is an urgent need to develop more effective and
safer antipsychotics beyond dopamine 2 receptor antagonists. An
emerging and promising approach is TAAR1 agonism. Therefore, we
will conduct a living systematic review and meta-analysis to synthesize and triangulate the evidence from preclinical animal experiments and
clinical studies on the efficacy, safety, and underlying mechanism of
action of TAAR1 agonism for psychosis.
Methods: Independent searches will be conducted in multiple
electronic databases to identify clinical and animal experimental
studies comparing TAAR1 agonists with licensed antipsychotics or
other control conditions in individuals with psychosis or animal
models for psychosis, respectively. The primary outcomes will be
overall psychotic symptoms and their behavioural proxies in animals.
Secondary outcomes will include side effects and neurobiological
measures. Two independent reviewers will conduct study selection,
data extraction using predefined forms, and risk of bias assessment
using suitable tools based on the study design. Ontologies will be
developed to facilitate study identification and data extraction. Data
from clinical and animal studies will be synthesized separately using
random-effects meta-analysis if appropriate, or synthesis without
meta-analysis. Study characteristics will be investigated as potential
sources of heterogeneity. Confidence in the evidence for each
outcome and source of evidence will be evaluated, considering the
summary of the association, potential concerns regarding internal
and external validity, and reporting biases. When multiple sources of
evidence are available for an outcome, an overall conclusion will be
drawn in a triangulation meeting involving a multidisciplinary team of
experts. We plan trimonthly updates of the review, and any
modifications in the protocol will be documented. The review will be
co-produced by multiple stakeholders aiming to produce impactful
and relevant results and bridge the gap between preclinical and
clinical research on psychosis
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