57 research outputs found
Towards better care for women with schizophrenia-spectrum disorders
Women with a schizophrenia-spectrum disorder (SSD) have a better clinical profile than do men at the start of their illness but progress to the same state within the first few years of living with SSD. There are benefits to be gained across different areas in the care currently offered to women with psychosis. An important point for improvement is the early detection of female-specific signs of a first episode of psychosis, to shorten the duration of untreated psychosis, with prompt access to early intervention services. Special attention should be paid to sexual health, and to any history of childhood trauma. Antipsychotics require dosing and prescription tailored to the female physiology that consider hormonal life phases such as menopause. Switching to prolactin-sparing medications can benefit both mental and somatic health. Finally, hormone replacement therapy should be considered for postmenopausal women. By providing female-specific care, women with schizophrenia-spectrum disorders will have optimal chances to fare well
Efficacy of non-invasive brain stimulation on cognitive functioning in brain disorders:a meta-analysis
Background Cognition is commonly affected in brain disorders. Non-invasive brain stimulation (NIBS) may have procognitive effects, with high tolerability. This meta-analysis evaluates the efficacy of transcranial magnetic stimulation (TMS) and transcranial Direct Current Stimulation (tDCS) in improving cognition, in schizophrenia, depression, dementia, Parkinson's disease, stroke, traumatic brain injury, and multiple sclerosis. Methods A PRISMA systematic search was conducted for randomized controlled trials. Hedges' g was used to quantify effect sizes (ES) for changes in cognition after TMS/tDCS v. sham. As different cognitive functions may have unequal susceptibility to TMS/tDCS, we separately evaluated the effects on: attention/vigilance, working memory, executive functioning, processing speed, verbal fluency, verbal learning, and social cognition. Results We included 82 studies (n = 2784). For working memory, both TMS (ES = 0.17, p = 0.015) and tDCS (ES = 0.17, p = 0.021) showed small but significant effects. Age positively moderated the effect of TMS. TDCS was superior to sham for attention/vigilance (ES = 0.20, p = 0.020). These significant effects did not differ across the type of brain disorder. Results were not significant for the other five cognitive domains. Conclusions Our results revealed that both TMS and tDCS elicit a small trans-diagnostic effect on working memory, tDCS also improved attention/vigilance across diagnoses. Effects on the other domains were not significant. Observed ES were small, yet even slight cognitive improvements may facilitate daily functioning. While NIBS can be a well-tolerated treatment, its effects appear domain specific and should be applied only for realistic indications (i.e. to induce a small improvement in working memory or attention)
The evolution of photosynthesis in chromist algae through serial endosymbioses
Chromist algae include diverse photosynthetic organisms of great ecological and social importance. Despite vigorous research efforts, a clear understanding of how various chromists acquired photosynthetic organelles has been complicated by conflicting phylogenetic results, along with an undetermined number and pattern of endosymbioses, and the horizontal movement of genes that accompany them. We apply novel statistical approaches to assess impacts of endosymbiotic gene transfer on three principal chromist groups at the heart of long-standing controversies. Our results provide robust support for acquisitions of photosynthesis through serial endosymbioses, beginning with the adoption of a red alga by cryptophytes, then a cryptophyte by the ancestor of ochrophytes, and finally an ochrophyte by the ancestor of haptophytes. Resolution of how chromist algae are related through endosymbioses provides a framework for unravelling the further reticulate history of red algal-derived plastids, and for clarifying evolutionary processes that gave rise to eukaryotic photosynthetic diversity
Characterizing speech heterogeneity in schizophrenia-spectrum disorders
Schizophrenia-spectrum disorders (SSD) are highly heterogeneous in risk factors, symptom characteristics, and disease course outcome. Although speech anomalies have long been recognized as a core symptom of SSD, speech markers are an unexplored source of symptom heterogeneity that may be informative in recognizing relevant subtypes. This study investigated speech heterogeneity and its relation to clinical characteristics in a large sample of patients with SSD and healthy controls. Speech samples were obtained from 142 patients with SSD and 147 healthy controls by means of open-ended interviews. Speech was analyzed using standardized open-source acoustic speech software. Hierarchical clustering was conducted using acoustic speech markers. Symptom severity was rated with the Positive and Negative Syndrome Scale, and cognition was assessed with the Brief Assessment of Cognition for Schizophrenia. Three speech clusters could be distinguished in the patient group that differed regarding speech properties, independent of medication use. One cluster was characterized by mild speech disturbances, while two severely impaired clusters were recognized (fragmented speakers and prolonged pausers). Both clusters with severely impaired speech had more severe cognitive dysfunction than the mildly impaired speakers. Prolonged pausers specifically had difficulties with memory-related tasks. Prolonged pausing, as opposed to fragmented speaking, related to chronic active psychosis and refractory psychotic symptoms. Based on speech clustering, subtypes of patients emerged with distinct disease trajectories, symptomatology, and cognitive functioning. The identification of clinically relevant subgroups within SSD may help to characterize distinct profiles and benefit the tailoring of early intervention and improvement of long-term functional outcome. (PsycInfo Database Record (c) 2022 APA, all rights reserved).</p
Red and Problematic Green Phylogenetic Signals among Thousands of Nuclear Genes from the Photosynthetic and Apicomplexa-Related Chromera velia
The photosynthetic and basal apicomplexan Chromera velia was recently described, expanding the membership of this otherwise nonphotosynthetic group of parasite protists. Apicomplexans are alveolates with secondary plastids of red algal origin, but the evolutionary history of their nuclear genes is still actively discussed. Using deep sequencing of expressed genes, we investigated the phylogenetic affinities of a stringent filtered set of 3,151 expressed sequence tag-contigs by generating clusters with eukaryotic homologs and constructing phylogenetic trees and networks. The phylogenetic positioning of this alveolate alga was determined and sets of phyla-specific proteins extracted. Phylogenetic trees provided conflicting signals, with 444 trees grouping C. velia with the apicomplexans but 354 trees grouping C. velia with the alveolate oyster pathogen Perkinsus marinus, the latter signal being reinforced from the analysis of shared genes and overall sequence similarity. Among the 513 C. velia nuclear genes that reflect a photosynthetic ancestry and for which nuclear homologs were available both from red and green lineages, 263 indicated a red photosynthetic ancestry, whereas 250 indicated a green photosynthetic ancestry. The same 1:1 signal ratio was found among the putative 255 nuclear-encoded plastid proteins identified. This finding of red and green signals for the alveolate mirrors the result observed in the heterokont lineage and supports a common but not necessarily single origin for the plastid in heterokonts and alveolates. The inference of green endosymbiosis preceding red plastid acquisition in these lineages leads to worryingly complicated evolutionary scenarios, prompting the search for other explanations for the green phylogenetic signal and the amount of hosts involved
Raloxifene augmentation in men and women with a schizophrenia spectrum disorder:A study protocol
Although acute psychotic symptoms are often reduced by antipsychotic treatment, many patients with schizophrenia are impaired in daily functioning due to the persistence of negative and cognitive symptoms. Raloxifene, a Selective Estrogen Receptor Modulator (SERM) has been shown to be an effective adjunctive treatment in schizophrenia. Yet, there is a paucity in evidence for raloxifene efficacy in men and premenopausal women. We report the design of a study that aims to replicate earlier findings concerning the efficacy of raloxifene augmentation in reducing persisting symptoms and cognitive impairment in postmenopausal women, and to extend these findings to a male and peri/premenopausal population of patients with schizophrenia. The study is a multisite, placebo-controlled, double-blind, randomised clinical trial in approximately 110 adult men and women with schizophrenia. Participants are randomised 1:1 to adjunctive raloxifene 120 mg or placebo daily during 12 weeks. The treatment phase includes measurements at three time points (week 0, 6 and 12), followed by a follow-up period of two years. The primary outcome measure is change in symptom severity, as measured with the Positive and Negative Syndrome Scale (PANSS), and cognition, as measured with the Brief Assessment of Cognition in Schizophrenia (BACS). Secondary outcome measures include social functioning and quality of life. Genetic, hormonal and inflammatory biomarkers are measured to assess potential associations with treatment effects. If it becomes apparent that raloxifene reduces psychotic symptoms and/or improves cognition, social functioning and/or quality of life as compared to placebo, implementation of raloxifene in clinical psychiatric practice can be considered
A Hypothesis for the Evolution of Nuclear-Encoded, Plastid-Targeted Glyceraldehyde-3-Phosphate Dehydrogenase Genes in “Chromalveolate” Members
Eukaryotes bearing red alga-derived plastids — photosynthetic alveolates (dinoflagellates plus the apicomplexan Toxoplasma gondii plus the chromerid Chromera velia), photosynthetic stramenopiles, haptophytes, and cryptophytes — possess unique plastid-targeted glyceraldehyde-3-phosphate dehydrogenases (henceforth designated as “GapC1”). Pioneering phylogenetic studies have indicated a single origin of the GapC1 enzymes in eukaryotic evolution, but there are two potential idiosyncrasies in the GapC1 phylogeny: Firstly, the GapC1 tree topology is apparently inconsistent with the organismal relationship among the “GapC1-containing” groups. Secondly, four stramenopile GapC1 homologues are consistently paraphyletic in previously published studies, although these organisms have been widely accepted as monophyletic. For a closer examination of the above issues, in this study GapC1 gene sampling was improved by determining/identifying nine stramenopile and two cryptophyte genes. Phylogenetic analyses of our GapC1 dataset, which is particularly rich in the stramenopile homologues, prompt us to propose a new scenario that assumes multiple, lateral GapC1 gene transfer events to explain the incongruity between the GapC1 phylogeny and the organismal relationships amongst the “GapC1-containing” groups. Under our new scenario, GapC1 genes uniquely found in photosynthetic alveolates, photosynthetic stramenopiles, haptophytes, and cryptopyhytes are not necessarily a character vertically inherited from a common ancestor
Experimental design and statistical rigor in phylogenomics of horizontal and endosymbiotic gene transfer
A growing number of phylogenomic investigations from diverse eukaryotes are examining conflicts among gene trees as evidence of horizontal gene transfer. If multiple foreign genes from the same eukaryotic lineage are found in a given genome, it is increasingly interpreted as concerted gene transfers during a cryptic endosymbiosis in the organism's evolutionary past, also known as "endosymbiotic gene transfer" or EGT. A number of provocative hypotheses of lost or serially replaced endosymbionts have been advanced; to date, however, these inferences largely have been post-hoc interpretations of genomic-wide conflicts among gene trees. With data sets as large and complex as eukaryotic genome sequences, it is critical to examine alternative explanations for intra-genome phylogenetic conflicts, particularly how much conflicting signal is expected from directional biases and statistical noise. The availability of genome-level data both permits and necessitates phylogenomics that test explicit, a priori predictions of horizontal gene transfer, using rigorous statistical methods and clearly defined experimental controls
EEF2 Analysis Challenges the Monophyly of Archaeplastida and Chromalveolata
BACKGROUND: Classification of eukaryotes provides a fundamental phylogenetic framework for ecological, medical, and industrial research. In recent years eukaryotes have been classified into six major supergroups: Amoebozoa, Archaeplastida, Chromalveolata, Excavata, Opisthokonta, and Rhizaria. According to this supergroup classification, Archaeplastida and Chromalveolata each arose from a single plastid-generating endosymbiotic event involving a cyanobacterium (Archaeplastida) or red alga (Chromalveolata). Although the plastids within members of the Archaeplastida and Chromalveolata share some features, no nucleocytoplasmic synapomorphies supporting these supergroups are currently known. METHODOLOGY/PRINCIPAL FINDINGS: This study was designed to test the validity of the Archaeplastida and Chromalveolata through the analysis of nucleus-encoded eukaryotic translation elongation factor 2 (EEF2) and cytosolic heat-shock protein of 70 kDa (HSP70) sequences generated from the glaucophyte Cyanophora paradoxa, the cryptophytes Goniomonas truncata and Guillardia theta, the katablepharid Leucocryptos marina, the rhizarian Thaumatomonas sp. and the green alga Mesostigma viride. The HSP70 phylogeny was largely unresolved except for certain well-established groups. In contrast, EEF2 phylogeny recovered many well-established eukaryotic groups and, most interestingly, revealed a well-supported clade composed of cryptophytes, katablepharids, haptophytes, rhodophytes, and Viridiplantae (green algae and land plants). This clade is further supported by the presence of a two amino acid signature within EEF2, which appears to have arisen from amino acid replacement before the common origin of these eukaryotic groups. CONCLUSIONS/SIGNIFICANCE: Our EEF2 analysis strongly refutes the monophyly of the Archaeplastida and the Chromalveolata, adding to a growing body of evidence that limits the utility of these supergroups. In view of EEF2 phylogeny and other morphological evidence, we discuss the possibility of an alternative eukaryotic supergroup
Single cell genome analysis supports a link between phagotrophy and primary plastid endosymbiosis
Two cases of primary plastid endosymbiosis are known. The first occurred ca. 1.6 billion years ago and putatively gave rise to the canonical plastid in algae and plants. The second is restricted to a genus of rhizarian amoebae that includes Paulinella chromatophora. Photosynthetic Paulinella species gained their plastid from an α-cyanobacterial source and are sister to plastid-lacking phagotrophs such as Paulinella ovalis that ingest cyanobacteria. To study the role of feeding behavior in plastid origin, we analyzed single-cell genome assemblies from six P. ovalis-like cells isolated from Chesapeake Bay, USA. Dozens of contigs in these cell assemblies were derived from prey DNA of α-cyanobacterial origin and associated cyanophages. We found two examples of horizontal gene transfer (HGT) in P. ovalis-like nuclear DNA from cyanobacterial sources. This work suggests the first evidence of a link between feeding behavior in wild-caught cells, HGT, and plastid primary endosymbiosis in the monophyletic Paulinella lineage
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