Examination of Hippocampal N-Methyl-D-Aspartate Receptors Following Chronic Intermittent Ethanol Exposure In Vitro

Chronic intermittent ethanol exposure (CIE) is associated with degeneration of hippocampal neurons. The present study used hippocampal cultures to examine the loss of NeuN immunoreactivity, a relaible marker or neuronal density, after 1, 2, or 3 cycles of 5 days EtOH exposure (50 mM), followed by a 24-hour period of EWD or continuous EtOH exposure. NeuN immunoreactivity was decreased by 13%, 19%, and 16% in the CA1, CA3, and dentate gyrus after 3 cycles of CIE respectively; thionine staining confirmed significant cellular losses within each hippocampal subregion. Two cycles of CIE in aged tissue cultures resulted in significant decreases in NeuN immunoreactivity in all hippocampal subregions; however continuous ethanol exposure or exposure to one cycle of CIE did not. Further, exposure to the N-Methyl-D-aspartate receptor (NMDAR) antagonist 2-amino-7-phosphonvaleric acid (APV) (30 uM) during periods of EWD attenuated the loss of NeuN in all hippocampal subregions, while exposure to APV (40 uM) prevented the loss of NeuN in the CA1 and dentate gyrus. These results suggest that the loss of mature neurons after CIE is associated with the overactivation on the NMDAR

Gαq-ASSOCIATED SIGNALING PROMOTES NEUROADAPTATION TO ETHANOL AND WITHDRAWAL-ASSOCIATED HIPPOCAMPAL DAMAGE

Prolonged, heavy consumption of alcohol produces marked neuroadaptations in excitatory neurotransmission. These effects are accelerated following patterns of intermittent heavy drinking wherein periods of heavy consumption are followed by periods of abstinence. Studies have shown that neuroadaptive changes in the glutamatergic N-methyl-D-aspartate (NMDA) receptor produces excitotoxicity during periods of withdrawal; however, upstream targets were not adequately characterized. The present studies sought to identify these targets by assessing the role of group 1 metabotropic glutamate receptors (mGluR) and intracellular calcium in promoting cytotoxicity of hippocampal cell layers in vitro. It was hypothesized that ethanol-induced activity of mGluR1-and-5 contributes to hippocampal cytotoxicity and promotes the behavioral effects of withdrawal in vivo. In order to identify and test this theory, rat hippocampal explants were co-exposed to chronic intermittent ethanol exposure with or without the addition of a group 1 mGluR antagonist to assess cytotoxicity in neuronal cell types. In a second study, adult male rodents were co-exposed to chronic intermittent ethanol exposure with or without the addition of an mGluR5 antagonist to assess the role of these receptors in the development of dependence as reflected in withdrawal behaviors. Together, these studies help to identify and screen toxicity of putative pharmacotherapies for the treatment of ethanol dependence in the clinical population

Buspirone Maintenance Does Not Alter the Reinforcing, Subjective, and Cardiovascular Effects of Intranasal Methamphetamine

Background—Medications development efforts for methamphetamine-use disorder have targeted central monoamines because these systems are directly involved in the effects of methamphetamine. Buspirone is a dopamine autoreceptor and D3 receptor antagonist and partial agonist at serotonin 1A receptors, making it a logical candidate medication for methamphetamine-use disorder. Buspirone effects on abuse-related behaviors of methamphetamine have been mixed in clinical and preclinical studies. Experimental research using maintenance dosing, which models therapeutic use, is limited. This study evaluated the influence of buspirone maintenance on the reinforcing effects of methamphetamine using a self-administration procedure, which has predictive validity for clinical efficacy. The impact of buspirone maintenance on the subjective and cardiovascular response to methamphetamine was also determined. Methods—Eight research participants (1 female) reporting recent illicit stimulant use completed a placebo-controlled, crossover, double-blind protocol in which the pharmacodynamic effects of intranasal methamphetamine (0, 15, and 30 mg) were assessed after at least 6 days of buspirone (0 and 45 mg/day) maintenance. Results—Intranasal methamphetamine functioned as a reinforcer and produced prototypical stimulant-like subjective (e.g., increased ratings of Good Effects and Like Drug) and cardiovascular (e.g., elevated blood pressure) effects. These effects of methamphetamine were similar under buspirone and placebo maintenance conditions. Maintenance on buspirone was well tolerated and devoid of effects when administered alone. Conclusions—These data suggest that buspirone is unlikely to be an effective pharmacotherapy for methamphetamine-use disorder. Given the central role of monoamines in methamphetamine-use disorder, it is reasonable for future studies to continue to target these systems

Acceptance and commitment therapy for appearance anxiety: three case studies

Introduction: Due to scarring, appearance anxiety is a common psychological difficulty in patients accessing burns services. Appearance anxiety can significantly impact upon social functioning and quality of life; thus, the availability of effective psychological therapies is vital. Acceptance and Commitment Therapy (ACT) is considered useful for treating distress associated with other health conditions and may lend itself well to appearance anxiety. However, no published research is currently available. Methods: Three single case studies (two male burns patients; one female necrotising fasciitis patient) are presented where appearance anxiety was treated using ACT. A treatment protocol was followed and evaluated: the Derriford Appearance Scale measured appearance anxiety; the Work and Social Adjustment Scale measured impairment in functioning; the Acceptance and Action Questionnaire measured acceptance (willingness to open up to distressing internal experiences); and the Committed Action Questionnaire measured engagement in meaningful and valued life activities. Measures were given at every treatment session and patient feedback was obtained. One-month follow-up data were available for two cases. Results: After the intervention, all patients had reduced functional impairment and were living more valued and meaningful lives. No negative effects were found. Discussion: These case studies suggest that ACT may be a useful psychological therapy for appearance anxiety. The uncontrolled nature of the intervention limits the conclusions that can be drawn. Conclusion: A pilot feasibility study to evaluate the effectiveness of ACT for appearance anxiety is warranted

Prevalence and predictors of obstructive sleep apnea in young children with Down syndrome

BackgroundChildren with Down syndrome (DS) are vulnerable to obstructive sleep apnoea (OSA) because of their unique craniofacial anatomy and hypotonia. Understanding the predictors of OSA in DS may enable targeted screening.MethodsChildren with DS (n = 202) aged from six months to below six years (110 boys) were recruited from three UK children's hospitals. The clinical assessment included height, weight and tonsillar size. The parents either set up cardiorespiratory polygraphy at home or chose laboratory studies. Studies with less than four hours of interpretable data were repeated where possible. American Academy of Sleep Medicine (AASM) 2012 scoring criteria were used to derive an obstructive apnoea/hypopnoea index (OAHI). Predictors of moderate to severe OSA were examined.ResultsIn total, 188/202 (93%) participants were successfully studied. Of these, 169 studies were completed at home and 19 in a sleep laboratory. Moderate to severe OSA, defined by an OAHI of &gt;5/h, was found in 14% and mild to moderate OSA (1/h≥OAHI &lt;5/h) was found in 59% of the children. Male gender and habitual snoring predicted OSA but did not have independent predictive power in the presence of the other factors. Age in months, body mass index (BMI) centile and tonsillar size did not predict OSA.ConclusionsModerate to severe OSA is common in very young children with DS. Examination of tonsillar size did not predict OSA severity. Population-based screening for OSA is recommended in these children, and domiciliary cardiorespiratory polygraphy is an acceptable screening approach. Further research is required to understand the natural history, associated morbidity, optimal screening methodology and treatment modality for OSA in these children.</p

Apatinib for the treatment of gastric cancer

Apatinib, a small-molecule inhibitor of vascular endothelial growth factor receptor 2, has demonstrated encouraging anti-cancer activity in gastric cancer within both in vitro and in vivo models. AREAS COVERED: Apatinib's efficacy, tolerability and safety have been evaluated in one Phase II and one Phase III study in metastatic/advanced gastric cancer. In this review, we focus on the mechanism of action of apatinib, its pharmacokinetic profile and its clinical activity in the treatment of advanced/metastatic gastric cancer. Expert commentary: Unfortunately, as yet, there is no definitive biomarker data for apatinib in gastric cance

Listening to women: experiences of using closed-loop in type 1 diabetes pregnancy

Introduction: Recent high-profile calls have emphasized that women's experiences should be considered in maternity care provisioning. We explored women's experiences of using closed-loop during type 1 diabetes (T1D) pregnancy to inform decision-making about antenatal rollout and guidance and support given to future users. Methods: We interviewed 23 closed-loop participants in the Automated insulin Delivery Among Pregnant women with T1D (AiDAPT) trial after randomization to closed-loop and ∼20 weeks later. Data were analyzed thematically. Results: Women described how closed-loop lessened the physical and mental demands of diabetes management, enabling them to feel more normal and sleep better. By virtue of spending increased time-in-range, women also worried less about risks to their baby and being judged negatively by health care professionals. Most noted that intensive input and support during early pregnancy had been crucial to adjusting to, and developing confidence in, the technology. Women emphasized that attaining pregnancy glucose targets still required ongoing effort from themselves and the health care team. Women described needing education to help them determine when, and how, to intervene and when to allow the closed-loop to operate without interference. All women reported more enjoyable pregnancy experiences as a result of using closed-loop; some also noted being able to remain longer in paid employment. Conclusions: Study findings endorse closed-loop use in T1D pregnancy by highlighting how the technology can facilitate positive pregnancy experiences. To realize fully the benefits of closed-loop, pregnant women would benefit from initial intensive oversight and support together with closed-loop specific education and training. Clinical Trial Registration number: NCT04938557

Genome-wide association analysis reveals QTL and candidate mutations involved in white spotting in cattle

International audienceAbstractBackgroundWhite spotting of the coat is a characteristic trait of various domestic species including cattle and other mammals. It is a hallmark of Holstein–Friesian cattle, and several previous studies have detected genetic loci with major effects for white spotting in animals with Holstein–Friesian ancestry. Here, our aim was to better understand the underlying genetic and molecular mechanisms of white spotting, by conducting the largest mapping study for this trait in cattle, to date.ResultsUsing imputed whole-genome sequence data, we conducted a genome-wide association analysis in 2973 mixed-breed cows and bulls. Highly significant quantitative trait loci (QTL) were found on chromosomes 6 and 22, highlighting the well-established coat color genes KIT and MITF as likely responsible for these effects. These results are in broad agreement with previous studies, although we also report a third significant QTL on chromosome 2 that appears to be novel. This signal maps immediately adjacent to the PAX3 gene, which encodes a known transcription factor that controls MITF expression and is the causal locus for white spotting in horses. More detailed examination of these loci revealed a candidate causal mutation in PAX3 (p.Thr424Met), and another candidate mutation (rs209784468) within a conserved element in intron 2 of MITF transcripts expressed in the skin. These analyses also revealed a mechanistic ambiguity at the chromosome 6 locus, where highly dispersed association signals suggested multiple or multiallelic QTL involving KIT and/or other genes in this region.ConclusionsOur findings extend those of previous studies that reported KIT as a likely causal gene for white spotting, and report novel associations between candidate causal mutations in both the MITF and PAX3 genes. The sizes of the effects of these QTL are substantial, and could be used to select animals with darker, or conversely whiter, coats depending on the desired characteristics

The human gut symbiont <i>Ruminococcus gnavus</i> shows specificity to blood group A antigen during mucin glycan foraging:Implication for niche colonisation in the gastrointestinal tract

The human gut symbiont Ruminococcus gnavus displays strain-specific repertoires of glycoside hydrolases (GHs) contributing to its spatial location in the gut. Sequence similarity network analysis identified strain-specific differences in blood-group endo-β-1,4-galactosidase belonging to the GH98 family. We determined the substrate and linkage specificities of GH98 from R. gnavus ATCC 29149, RgGH98, against a range of defined oligosaccharides and glycoconjugates including mucin. We showed by HPAEC-PAD and LC-FD-MS/MS that RgGH98 is specific for blood group A tetrasaccharide type II (BgA II). Isothermal titration calorimetry (ITC) and saturation transfer difference (STD) NMR confirmed RgGH98 affinity for blood group A over blood group B and H antigens. The molecular basis of RgGH98 strict specificity was further investigated using a combination of glycan microarrays, site-directed mutagenesis, and X-ray crystallography. The crystal structures of RgGH98 in complex with BgA trisaccharide (BgAtri) and of RgGH98 E411A with BgA II revealed a dedicated hydrogen network of residues, which were shown by site-directed mutagenesis to be critical to the recognition of the BgA epitope. We demonstrated experimentally that RgGH98 is part of an operon of 10 genes that is overexpresssed in vitro when R. gnavus ATCC 29149 is grown on mucin as sole carbon source as shown by RNAseq analysis and RT-qPCR confirmed RgGH98 expression on BgA II growth. Using MALDI-ToF MS, we showed that RgGH98 releases BgAtri from mucin and that pretreatment of mucin with RgGH98 confered R. gnavus E1 the ability to grow, by enabling the E1 strain to metabolise BgAtri and access the underlying mucin glycan chain. These data further support that the GH repertoire of R. gnavus strains enable them to colonise different nutritional niches in the human gut and has potential applications in diagnostic and therapeutics against infection

Coevolved mutations reveal distinct architectures for two core proteins in the bacterial flagellar motor

Switching of bacterial flagellar rotation is caused by large domain movements of the FliG protein triggered by binding of the signal protein CheY to FliM. FliG and FliM form adjacent multi-subunit arrays within the basal body C-ring. The movements alter the interaction of the FliG C-terminal (FliGC) "torque" helix with the stator complexes. Atomic models based on the Salmonella entrovar C-ring electron microscopy reconstruction have implications for switching, but lack consensus on the relative locations of the FliG armadillo (ARM) domains (amino-terminal (FliGN), middle (FliGM) and FliGC) as well as changes during chemotaxis. The generality of the Salmonella model is challenged by the variation in motor morphology and response between species. We studied coevolved residue mutations to determine the unifying elements of switch architecture. Residue interactions, measured by their coevolution, were formalized as a network, guided by structural data. Our measurements reveal a common design with dedicated switch and motor modules. The FliM middle domain (FliMM) has extensive connectivity most simply explained by conserved intra and inter-subunit contacts. In contrast, FliG has patchy, complex architecture. Conserved structural motifs form interacting nodes in the coevolution network that wire FliMM to the FliGC C-terminal, four-helix motor module (C3-6). FliG C3-6 coevolution is organized around the torque helix, differently from other ARM domains. The nodes form separated, surface-proximal patches that are targeted by deleterious mutations as in other allosteric systems. The dominant node is formed by the EHPQ motif at the FliMMFliGM contact interface and adjacent helix residues at a central location within FliGM. The node interacts with nodes in the N-terminal FliGc α-helix triad (ARM-C) and FliGN. ARM-C, separated from C3-6 by the MFVF motif, has poor intra-network connectivity consistent with its variable orientation revealed by structural data. ARM-C could be the convertor element that provides mechanistic and species diversity.JK was supported by Medical Research Council grant U117581331. SK was supported by seed funds from Lahore University of Managment Sciences (LUMS) and the Molecular Biology Consortium