Positive AMPA receptor modulation in the treatment of neuropsychiatric disorders: A long and winding road

Glutamatergic transmission is widely implicated in neuropsychiatric disorders, and the discovery that ketamine elicits rapid-acting antidepressant effects by modulating α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) signaling has spurred a resurgence of interest in the field. This review explores agents in various stages of development for neuropsychiatric disorders that positively modulate AMPARs, both directly and indirectly. Despite promising preclinical research, few direct and indirect AMPAR positive modulators have progressed past early clinical development. Challenges such as low potency have created barriers to effective implementation. Nevertheless, the functional complexity of AMPARs sets them apart from other drug targets and allows for specificity in drug discovery. Additional effective treatments for neuropsychiatric disorders that work through positive AMPAR modulation may eventually be developed.     

Does perioperative biological therapy increase 30-day post-operative complication rates in inflammatory bowel disease patients undergoing intra-abdominal surgery? A systematic review

BackgroundBiopharmaceuticals revolutionised inflammatory bowel disease (IBD) treatment. However, it is postulated they compromise immunity, collagen production and angiogenesis resulting in infective post-operative complications and altered wound/anastomotic healing. Research has failed to agree on risks associated with perioperative biologics therefore it was anticipated that a systematic review may provide a consensus and contribute recommendations for clinical practice.MethodsA systematic review conducted as per PRISMA guidelines included a methodical search of PubMed, Google Scholar, EMBASE/Ovid and Cochrane Library using MeSH and/or keywords for papers published between 01/01/1998 and 04/02/2019.The population analysed included adult ulcerative colitis, Crohn's disease, Indeterminate Colitis or IBD unclassified patients. The intervention was intra-abdominal surgery in patients treated with biological therapy in the preceding 12 weeks compared to patients who had intra-abdominal surgery without biological therapy within the defined timeframe. The primary outcome was surgical site infection (SSI) with secondary outcomes including wound dehiscence, intra-abdominal sepsis/abscess, systemic infection and anastomotic breakdown within 30 days post-procedure. Papers were evaluated by two independent reviewers and those included were assessed for quality/bias using the Newcastle–Ottowa scale.Results2064 UC, Crohn's and IC patients were analysed across 8 included studies. Several studies' multivariate analyses demonstrated corticosteroids to be independent predictors of morbidity. There are no increased complications associated with anti-TNFα exposure while vedolizumab increased SSI and small bowel obstruction.ConclusionProspective studies and randomised control trials are required to clarify study outcomes and recommendations published to date. Presently, biologics should continue to be used and considered beneficial in this population.     

Effects of clonidine on breathing during sleep and susceptibility to central apnoea

We hypothesized that administration of clonidine would decrease the hypocapnic apnoeic threshold (HAT) and widen the CO₂ reserve during non-REM sleep.     

Histamine-4 receptor antagonist ameliorates Parkinson-like pathology in the striatum

Growing evidence indicates that microglia activation and a neuroinflammatory trigger contribute to dopaminergic cell loss in Parkinson’s disease (PD). Furthermore, increased density of histaminergic fibers and enhanced histamine levels have been observed in the substantia nigra of PD-postmortem brains. Histamine-induced microglial activation is mediated by the histamine-4 receptor (H₄R). In the current study, gene set enrichment and pathway analyses of a PD basal ganglia RNA-sequencing dataset revealed that upregulation of H₄R was in the top functional category for PD treatment targets. Interestingly, the H₄R antagonist JNJ7777120 normalized the number of nigrostriatal dopaminergic fibers and striatal dopamine levels in a rotenone-induced PD rat model. These improvements were accompanied by a reduction of α-synuclein-positive inclusions in the striatum. In addition, intracerebroventricular infusion of JNJ7777120 alleviated the morphological changes in Iba-1-positive microglia and resulted in a lower tumor necrosis factor-α release from this brain region, as well as in ameliorated apomorphine-induced rotation behaviour. Finally, JNJ7777120 also restored basal ganglia function by decreasing the levels of γ-aminobutyric acid (GABA) and the 5-hydroxyindoleactic acid to serotonin (5-HIAA/5-HT) concentration ratios in the striatum of the PD model. Our results highlight H₄R inhibition in microglia as a promising and specific therapeutic target to reduce or prevent neuroinflammation, and as such the development of PD pathology.     

Synergistic actions of pemphigus vulgaris IgG,Fas-ligand and tumor necrosis factor-α during induction of basal cell shrinkage and acantholysis

This study tested a recently proposed “Basal Cell Shrinkage” hypothesis of pemphigus acantholysis through a quantitative analysis of individual and cooperative effects of pemphigus vulgaris (PV) IgG, Fas-ligand (Fas-L) and tumor necrosis factor-α (TNFα) on keratinocyte (KC) volume (i.e. cell size) and adhesive properties. Exposure of KC monolayers and MatTek EpiDermFT? tissues cultures to the physiologic concentrations of Fas-L, TNFα or IgGs from two PV patients resulted in various degrees of reversible changes, which were not observed in control cultures either exposed to normal IgG or left intact. Within 12–24 h of exposure, basal cells in experimental cultures lost their ability to form stress fibers, retracted cytoplasmic aprons and formed keratin aggregates, indicating that their cytoskeleton collapsed. The cell volume decreased significantly (p < 0.05) as the polygonal cell shape changed to a round one. The shrunk cells detached from their neighbors and the substrate, resulting in a reciprocal increase of both the areas of acantholysis and the number of detached KCs, respectively. Since in the skin of PV patients, KCs are targeted by autoantibodies concomitantly with being exposed to autocrine and paracrine pro-apoptotic and pro-inflammatory cytokines, we combined PV IgG with Fas-L and/or TNFα in the cell culture experiments. This amplified several fold an ability of PV IgG to cause basal cell shrinkage and detachment. The obtained results demonstrated for the first time that PV IgG works together with Fas-L and TNFα to induce acantholysis via basal cell shrinkage, which provides a novel mechanism explaining successful treatment of PV patients with TNFα inhibitors.     

Steroid Hormone Action in Musculoskeletal Cells Involves Membrane Receptor and Nuclear Receptor Mechanisms

Steroid hormones regulate target cells through traditional nuclear mechanisms as well as by membrane mechanisms. 1 &#102 ,25(OH) 2 D 3 and 24R,25(OH) 2 D 3 bind membrane receptors (mVDR) and mediate their effects on the physiological responses of musculoskeletal cells via protein kinase C (PKC). In cultures of costochondral growth plate chondrocytes, 1 &#102 ,25(OH) 2 D 3 binds the 1,25-mVDR in growth zone cells, activating phospholipase C (PLC), leading to diacylglycerol (DAG) production and PKC translocation to the plasma membrane. It also activates PLA 2 , increasing arachidonic acid release and prostaglandin synthesis. 24R,25(OH) 2 D 3 binds its membrane receptor in resting zone chondrocytes, activating phospholipase D (PLD), and increasing DAG and PKC activity, but translocation does not occur. PLA 2 activity is decreased, reducing arachidonic acid and prostaglandin production. 17 &#103 -Estradiol (E 2 ) activates PKC in both cartilage cells, but DAG is not involved. 1 &#102 ,25(OH) 2 D 3 and 24R,25(OH) 2 D 3 also increase PKC in osteoblasts in a cell-specific manner. Antibodies to the 1,25-mVDR block PKC activation. Membrane-mediated events influence gene expression via signaling cascades, including the ERK1/2 MAP kinases. The ability of steroid hormones to initiate events nongenomically is important for regulation of matrix vesicle (MV) function in the extracellular matrix. MVs have mVDRs, but ligand binding inhibits PKC-zeta (PKC &#145 ) via a mechanism that differs from PKC &#102 activation in the plasma membranes. Treatment of MVs from growth zone chondrocyte cultures with 1 &#102 ,25(OH) 2 D 3 releases stromelysin-1 (MMP-3) and increases TGF- &#103 activation. MMP-3 is also involved in proteoglycan degradation, facilitating calcification. 24R,25(OH) 2 D 3 inhibits PKC &#145 in MV from resting zone cell cultures and inhibits MMP-3 release. Chondrocytes and osteoblasts produce 1,25(OH) 2 D 3 , 24,25(OH) 2 D 3 , and E 2 ; thus, locally produced steroids may function as autocrine regulators of matrix events, including matrix vesicle enzyme activity and matrix protein remodelling during longitudinal growth, calcification, and growth factor activation.     

The leaf extract of Spondias mombin L. displays an anti-inflammatory effect and suppresses inducible formation of tumor necrosis factor-α and nitric oxide (NO)

Extracts of Spondias mombin L. (Anacardiacea) is used in the traditional medicine of Africa and Latin America to treat many inflammatory conditions, with repeated claims of efficacy. However, there are no scientific data yet to support these claims and the mechanism through which the extract may be acting is still unknown. This study was undertaken to investigate the effects of the methanolic extract of the leaf of S. mombin (SM) on inflammation and to uncover some of the possible mechanisms that could explain any observed changes. The anti-inflammatory activity of the extract was investigated in Wistar rats using intraplantar injection of carrageenan as an in vivo model of inflammation. The effect of oral supplementation of the SM extract on tumor necrosis factor (TNF)-α levels after an intraperitoneal lipopolysaccharide (LPS; 1?mg/kg) challenge was investigated in mice. The effect of SM on TNF-α and inducible nitric oxide (iNO) production by LPS-stimulated bone marrow-derived macrophages (BM-MØ) was also investigated in vitro. BM-MØ were preincubated for 2?h with SM (0–100?µg/ml), activated with LPS, and then TNF-α and NO production measured in the cell-free conditioned culture supernatant after 24?h of incubation. The study showed that pre-treatment of rats with the SM extract (at 100, 200, and 400?mg/kg, per os) caused a significant dose-related inhibition of carrageenan-induced paw edema over a 4-h period. In treated mice, LPS-inducible (systemic) TNF-α levels were found to be significantly lower as a result of their receiving the SM extract. In vitro, SM treatment caused a dose-dependent decrease in LPS-inducible TNF-α and NO production by BM-MØ compared to the effects of treatment of the cells with LPS alone. Taken together, the results of these studies suggest that supplementation with SM extract can alleviate inflammatory responses and that this could possibly be via a suppression of the production of pro-inflammatory mediators and cytokines such as TNF-α and iNO.     

Preoperative Management of Endocrine,Hormonal, and Urologic Medications: Society for Perioperative Assessment and Quality Improvement (SPAQI) Consensus Statement

Perioperative medical management is challenging due to the rising complexity of patients presenting for surgical procedures. A key part of preoperative optimization is appropriate management of long-term medications, yet guidelines and consensus statements for perioperative medication management are lacking. Available resources utilize the recommendations derived from individual studies and do not include a multidisciplinary focus or formal consensus. The Society for Perioperative Assessment and Quality Improvement (SPAQI) identified a lack of authoritative clinical guidance as an opportunity to utilize its multidisciplinary membership to improve evidence-based perioperative care. SPAQI seeks to provide guidance on perioperative medication management that synthesizes available literature with expert consensus. The aim of this Consensus Statement is to provide practical guidance on the preoperative management of endocrine, hormonal, and urologic medications. A panel of experts with anesthesiology, perioperative medicine, hospital medicine, general internal medicine, and medical specialty experience was drawn together and identified the common medications in each of these categories. The authors then utilized a modified Delphi approach to critically review the literature and generate consensus recommendations.     

An Adrenal Incidentaloma Diagnosed as Dopamine-Secreting Pheochromocytoma: A Case Report

BackgroundDopamine-secreting pheochromocytomas are exceedingly rare.Case presentationA 28-year-old woman, who was admitted due to 4 hours of acute-onset abdominal pain, detected an adrenal mass incidentally. She was almost asymptomatic without a known family history. Laboratory assessments showed significant increases in dopamine levels of serum and 24-h urinary. By using preoperative a-adrenergic receptor blockers, she developed orthostatic hypotension and palpitations. When she underwent laparoscopic left adrenalectomy, she experienced rapid cyclic fluctuations in systolic blood pressure from 90 mmHg to 200 mmHg. Postoperatively, she exhibited prolonged hypotension, requiring vasopressor therapy and fluid replacement. According to histopathological diagnosis, it was a pheochromocytoma. Dopamine levels in 24-h urine and serum decreased to normal after operation. Analysis of specific gene SDHB, SDHD, RET, VHL and NF1 detected no pathogenic mutations.ConclusionPatients with dopamine-secreting pheochromocytomas are mostly asymptomatic, leading to a significant delay in diagnosis. There is a large possibility for dopamine-secreting pheochromocytomas to show a malignant tendency than the adrenergic and noradrenergic phenotypes. The a-adrenergic receptor blocker is not indicated for preoperative medical treatment because it can cause hypotension and cardiovascular failure. Calcium channel blockers or metyrosine may be better alternatives. All patients with pheochromocytomas should receive targeted genetic testing based on specific clinical features. SDHB, SDHD, RET, VHL and NF1 mutations are suggested for genetic testing of adrenal dopamine-secreting pheochromocytomas.