After the emergence of Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and Middle East Respiratory Syndrome Coronavirus (MERS-CoV) in the last two decades, the world is facing its new challenge in Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic with unprecedented global response. With the expanding domain of presentations in COVID-19 patients, the full range of manifestations is yet to unfold. The classical clinical symptoms for SARS-CoV-2 affected patients are dry cough, high fever, dyspnoea, lethal pneumonia whereas many patients have also been found to be associated with a few additional signs and clinical manifestations of isolated vasculopathy. Albeit a deep and profound knowledge has been gained on the clinical features and management of COVID-19, less clear association has been provided on SARS-CoV-2 mediated direct or indirect vasculopathy and its possible correlation with disease prognosis. The accumulative evidences suggest that novel coronavirus, apart from its primary respiratory confinement, may also invade vascular endothelial cells of several systems including cerebral, cardio-pulmonary as well as renal microvasculature, modulating multiple visceral perfusion indices. Here we analyse the phylogenetic perspective of SARS-CoV-2 along with other strains of β-coronaviridae from a standpoint of vasculopathic derangements. Based on the existing case reports, literature and open data bases, we also analyse the differential pattern of vasculopathy related changes in COVID-19 positive patients. Besides, we debate the need of modulation in clinical approach from a hemodynamical point of view, as a measure towards reducing disease transmission, morbidity and mortality in SARS-CoV-2 affected patients.
BackgroundGiven increasing rates of resistance to existing therapy, new options for treatment and prophylaxis of malaria are needed.MethodsTwo randomised, comparative, non-inferiority studies were conducted in Africa, one double-blinded and one open-label. Adults with fever, a positive peripheral blood smear, and a positive rapid diagnostic test for Plasmodium falciparum were randomised in both studies to either azithromycin (AZ) 1,000 mg plus chloroquine (CQ) 600-mg base (AZCQ 1,000 mg) once daily for three days or mefloquine hydrochloride (MQ) 1,250 mg (split dose). In the first study, an additional regimen of AZ 500 mg plus CQ 600-mg base (AZCQ 500 mg) once daily for three days was included. All study participants were hospitalised until three consecutive daily blood smears were negative for asexual P. falciparum parasitaemia. Study participants were evaluated weekly for 42 days, with Day 28 polymerase chain reaction (PCR)-corrected parasitological clearance rate as primary endpoint.ResultsA total of 467 subjects were randomised in the two studies. At 28 days’ follow-up, PCR-corrected parasitological clearance rates in the per protocol population in the first study were 101/103 (98%) with AZCQ 1,000 mg compared with 102/103 (99%) with MQ (95% confidence interval [CI]: -5.2, 3.3). The AZCQ 500-mg regimen was stopped during an interim study review (six [86%] clearance of seven evaluable; two lost to follow-up). In the second study, clearance rates were similar: AZCQ 1,000 mg 107/107 (100%) vs MQ 111/112 (99%; 95% CI: -1.8, 3.6). Among the participating countries, in vitro CQ resistance based on pfcrt mutation frequency in the baseline isolates across both studies ranged from 20.8% (Zambia) to 96.1% (Uganda). Serious adverse events (AEs; all causality) were observed more frequently with MQ compared with AZCQ (four vs one, respectively), though discontinuations for AEs were similar (four vs three, respectively). Common AEs in the AZ-containing arms included pruritus, vomiting, dizziness, and headache.ConclusionsAmong adults with symptomatic uncomplicated falciparum malaria in Africa, the combination of AZ 1,000 mg and CQ 600-mg base once daily for three days resulted in Day 28 PCR-corrected parasitological clearance rates of ≥98% and was non-inferior to treatment with MQ. AZCQ was well tolerated.Trial registrationClinicalTrials.gov identifiers NCT00082576 and NCT00367653Electronic supplementary materialThe online version of this article (doi:10.1186/1475-2875-13-458) contains supplementary material, which is available to authorized users.
Stromal cell-derived factor-1 (SDF-1 or CXCL12) is the physiologic ligand for the chemokine receptor CXCR4. CXCR4-mediated signalling regulates cell migration and apoptosis in certain haematopoietic and neuronal cells. Using gene profiling, we determined that CXCR4 is the only chemokine receptor for which mRNA expression is regulated during trophoblast differentiation in vitro. Based on the known effects of CXCR4 ligation, we hypothesized that CXCR4 activation may regulate placental trophoblast cell survival (i.e. protection from apoptosis), an important mechanism for the establishment and maintenance of the uteroplacental barrier. Human cytotrophoblasts (CTBs) were cultured in defined media and treated with graded doses of SDF-1 (10-100 ng/ml) or with an anti-CXCR4 neutralizing antibody. Exposure to anti-CXCR4 antibody reduced CTB cell numbers by 25-40%. Treatment with SDF-1 decreased the proportions of apoptotic terminal deoxynucleotidyl transferase-mediated dUTP-FITC nick-end labelling(+) cells (apoptotic index [AI] of 2.79+/-0.61% [control] versus 1.88+/-0.56% [SDF-1]; P<0.05) and caspase-activated cells (AI of 7.95+/-2.49% [control] versus 3.81+/-1.49% [SDF-1]; P<0.05). We determined that SDF-1 also activated the triple MAP Kinase isoforms ERK1/2 and p38 in trophoblasts. Immunocytochemistry confirmed SDF-1-induced nuclear translocation of phosphorylated ERK1/2. Blocking of ERK1/2 signalling with the specific inhibitor PD98059 reversed SDF-1-mediated inhibition of apoptosis (AI of 1.65+/-0.34 [SDF-1] versus 3.50+/-0.5 [SDF-1 + PD98059]; P<0.05), suggesting that SDF-1 acts through this pathway as a trophoblast survival factor. These results indicate that SDF-1/CXCR4 signalling stimulates anti-apoptotic pathways in cultured trophoblasts. This chemotactic ligand/receptor system may promote trophoblast survival during pregnancy. Alterations in SDF-1 and/or CXCR4 expression or function may be associated with specific pregnancy disorders.
The placenta expresses high levels of 11beta-hydroxysteroid dehydrogenase type 2 (11betaHSD2) that converts cortisol into inactive 11-keto metabolites and effectively protects the developing fetus from maternal cortisol during pregnancy. Impairment of this glucocorticoid barrier has adverse effects on fetal outcomes. A similar spectrum of adverse fetal effects is induced by antenatal stress during pregnancy. To examine the hypothesis that physiological stress may regulate placental 11betaHSD2 gene expression, we examined the effects of the catecholamines norepinephrine (NE) and epinephrine (E) on 11betaHSD2 expression in human trophoblastic cells. With the use of Northern blotting and semiquantitative RT-PCR, we determined that NE and E rapidly downregulate 11betaHSD2 steady-state mRNA levels in early- and late-gestation human trophoblasts and BeWo trophoblastic cells. Experiments using different adrenoceptor subtype-selective agonists and antagonists demonstrated that this catecholamine suppression of 11betaHSD2 mRNA expression is mediated via both alpha(1)- and alpha(2)-adrenoceptors and is independent of beta-adrenergic stimulation. To examine transcriptional regulation, BeWo cells were transiently transfected with a reporter construct in which an 11betaHSD2 human promoter sequence was inserted upstream of the luciferase gene. Treatment with 10(-7) M NE decreased luciferase activity by ~60% (n = 3, P < 0.01). These results suggest the NE/E-mediated decrease in placental 11betaHSD2 gene expression is an instance of alpha-adrenoceptor-specific rapid transcriptional inhibition of an adrenergic target gene. This molecular mechanism may be involved in the deleterious effects of antenatal physiological stress on fetoplacental growth and development.
BackgroundTo explore the use of azithromycin–chloroquine (AZCQ) for the treatment of malaria, we conducted double-blind, randomized, non-inferiority studies in India, Colombia, and Suriname comparing the combination of azithromycin 1 g and chloroquine (CQ) 600 mg base once daily (QD) for 3 days versus atovaquone–proguanil (AP) or chloroquine plus sulfadoxine–pyrimethamine (SPCQ) in adults with acute uncomplicated Plasmodium falciparum malaria.MethodsPatients were hospitalized until three documented negative blood smears and followed through Day 42. The primary end point was parasitologic cure at Day 28.ResultsIn India, parasite clearance rates were 84% and 94% for AZCQ and SPCQ, respectively (95% confidence interval [CI] for the difference: −22.6, 0.8). In Colombia and Suriname, parasite clearance rates were 57% and 99% for AZCQ and AP, respectively (95% CI: −52, −32). A subsequent open-label, non-comparative third study using a 2 g dose of azithromycin and 600 mg of CQ in India and Colombia resulted in an overall efficacy rate of 97%.ConclusionIn India, Colombia, and Suriname, 1 g azithromycin with CQ QD for 3 days was inferior to established comparator agents. An improved response rate was observed when the dose of azithromycin was increased to 2 g.
The aminoglycoside antibiotic kanamycin inhibits fibrillation of α-synuclein both in solution and in contact with lipid-membranes, forming amorphous/off-pathway aggregates instead.
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