Pulmonary Artery Diastolic Pressure as a Surrogate for Pulmonary Capillary Wedge Pressure in Cardiogenic Shock.

BACKGROUND: It is common for clinicians to use the pulmonary artery diastolic pressure (PADP) as a surrogate for the pulmonary capillary wedge pressure (PCWP). Here, we determine the validity of this relationship in patients with various phenotypes of cardiogenic shock (CS). METHODS AND RESULTS: In this analysis of the Critical Care Cardiology Trials Network registry, we identified 1225 people admitted with CS who received pulmonary artery catheters. Linear regression, Bland-Altman and receiver operator characteristic analyses were performed to determine the strength of the association between PADP and PCWP in patients with left-, right-, biventricular, and other non-myocardia phenotypes of CS (eg, arrhythmia, valvular stenosis, tamponade). There was a moderately strong correlation between PADP and PCWP in the total population (r = 0.64, n = 1225) and in each CS phenotype, except for right ventricular CS, for which the correlation was weak (r = 0.43, n = 71). Additionally, we found that a PADP ≥ 24 mmHg can be used to infer a PCWP ≥ 18 mmHg with ≥ 90% confidence in all but the right ventricular CS phenotype. CONCLUSIONS: This analysis validates the practice of using PADP as a surrogate for PCWP in most patients with CS; however, it should generally be avoided in cases of right ventricular-predominant CS.

An integrated buoy-satellite based coastal water quality nowcasting system: India's pioneering efforts towards addressing UN ocean decade challenges.

The Indian coastal waters are stressed due to a multitude of factors, such as the discharge of industrial effluents, urbanization (municipal sewage), agricultural runoff, and river discharge. The coastal waters along the eastern and western seaboard of India exhibit contrasting characteristics in terms of seasonality, the magnitude of river influx, circulation pattern, and degree of anthropogenic activity. Therefore, understanding these processes and forecasting their occurrence is highly necessary to secure the health of coastal waters, habitats, marine resources, and the safety of tourists. This article introduces an integrated buoy-satellite based Water Quality Nowcasting System (WQNS) to address the unique challenges of water quality monitoring in Indian coastal waters and to boost the regional blue economy. The Indian National Centre for Ocean Information Services (INCOIS) has launched a first-of-its-kind WQNS, and positioned the buoys at two important locations along the east (Visakhapatnam) and west (Kochi) coast of India, covering a range of environmental conditions and tourist-intensive zones. These buoys are equipped with different physical-biogeochemical sensors, data telemetry systems, and integration with satellite-based observations for real-time data transmission to land. The sensors onboard these buoys continuously measure 22 water quality parameters, including surface current (speed and direction), salinity, temperature, pH, dissolved oxygen, phycocyanin, phycoerythrin, Coloured Dissolved Organic Matter, chlorophyll-a, turbidity, dissolved methane, hydrocarbon (crude and refined), scattering, pCO2 (water and air), and inorganic macronutrients (nitrite, nitrate, ammonium, phosphate, silicate). This real-time data is transmitted to a central processing facility at INCOIS, and after necessary quality control, the data is disseminated through the INCOIS website. Preliminary results from the WQNS show promising outcomes, including the short-term changes in the water column oxic and hypoxic regimes within a day in coastal waters off Kochi during the monsoon period, whereas effluxing of high levels of CO2 into the atmosphere associated with the mixing of water, driven by local depression in the coastal waters off Visakhapatnam. The system has demonstrated its ability to detect changes in the water column properties due to episodic events and mesoscale processes. Additionally, it offers valuable data for research, management, and policy development related to coastal water quality.

The Bay of Bengal exposes abundant photosynthetic picoplankton and newfound diversity along salinity-driven gradients.

The Bay of Bengal (BoB) is a 2,600,000 km2 expanse in the Indian Ocean upon which many humans rely. However, the primary producers underpinning food chains here remain poorly characterized. We examined phytoplankton abundance and diversity along strong BoB latitudinal and vertical salinity gradients-which have low temperature variation (27-29°C) between the surface and subsurface chlorophyll maximum (SCM). In surface waters, Prochlorococcus averaged 11.7 ± 4.4 × 104 cells ml-1 , predominantly HLII, whereas LLII and 'rare' ecotypes, HLVI and LLVII, dominated in the SCM. Synechococcus averaged 8.4 ± 2.3 × 104 cells ml-1 in the surface, declined rapidly with depth, and population structure of dominant Clade II differed between surface and SCM; Clade X was notable at both depths. Across all sites, Ostreococcus Clade OII dominated SCM eukaryotes whereas communities differentiated strongly moving from Arabian Sea-influenced high salinity (southerly; prasinophytes) to freshwater-influenced low salinity (northerly; stramenopiles, specifically, diatoms, pelagophytes, and dictyochophytes, plus the prasinophyte Micromonas) surface waters. Eukaryotic phytoplankton peaked in the south (1.9 × 104 cells ml-1 , surface) where a novel Ostreococcus was revealed, named here Ostreococcus bengalensis. We expose dominance of a single picoeukaryote and hitherto 'rare' picocyanobacteria at depth in this complex ecosystem where studies suggest picoplankton are replacing larger phytoplankton due to climate change.

Echocardiographic Characteristics of Cardiogenic Shock Patients with and Without Cardiac Arrest.

BACKGROUND: Cardiac arrest (CA) is associated with worse outcomes in patients with cardiogenic shock (CS). To better understand the contribution of CA on CS, we evaluated transthoracic echocardiography (TTE) parameters in CS patients with and without CA. METHODS: We retrospectively identified CS patients with a TTE performed near cardiac intensive care unit admission between 2007 to 2018. We compared TTE measurements of left ventricular (LV) and right ventricular (RV) function in patients with and without CA. The primary outcome was all-cause in-hospital mortality, as determined using multivariable logistic regression. RESULTS: We included 1085 patients, 35% of whom had CA. Median age was 70 years and 37% were females. CA patients had higher severity of illness, more invasive mechanical ventilation and greater vasopressor/inotrope use. In-hospital mortality was 31% and was higher in CA patients (45% vs. 23%, p <0.001). Although LV ejection fraction (LVEF) was similar (35% vs. 37%, p = 0.05), CA patients had lower cardiac index, mitral valve E wave peak velocity, E/A ratio and E/e' ratio. TTE variables that were associated with hospital mortality varied, among patients with CA, these included measures of RV pressure and function and among patients without CA, these included parameters reflecting LV systolic function. CONCLUSIONS: Doppler assessments of RV systolic dysfunction were the strongest TTE predictors of hospital mortality in CS patients with CA, unlike CS patients without CA in whom LV systolic function was more important. This emphasizes the importance of RV assessment for mortality risk stratification after CA.

Shock Teams: A Contemporary Review.

PURPOSE OF REVIEW: Cardiogenic shock (CS) is a time-sensitive and often fatal condition. To address this issue, many centers have developed multidisciplinary shock teams with a common goal of expediting the recognition and treatment of CS. In this review, we examine the mission, structure, implementation, and outcomes reported by these early shock teams. RECENT FINDINGS: To date, there have been four observational shock team analyses, each providing unique insight into the utility of the shock team. The limited available data supports that shock teams are associated with improved CS mortality. However, there is considerable operational heterogeneity among shock teams, and randomized data assessing their value and best practices in both local and regional care models are needed.

Cardiovascular Mechanisms of Exercise Intolerance in Older Patients with Heart Failure.

Exercise intolerance, measured by peak oxygen consumption (V̇O2), is a hallmark feature of heart failure (HF). The effect is compounded in the elderly HF patient by aging-associated changes such as a reduction in lean muscle mass, an increase in adiposity, and a reduction in maximal heart rate and peripheral blood flow with exercise. There is a non-linear reduction in peak V̇O2 with age that accelerates in the later decades of life. Peak V̇O2 is further reduced due to central and peripheral maladaptation from HF. Central mechanisms include impaired peak heart rate, stroke volume, contractility, increased filling pressures, and a blunted vasodilatory response. Peripheral mechanisms include endothelial dysfunction, reduced blood flow to muscles, and impaired skeletal muscle oxidative capacity. This review presents a focused update on mechanisms leading to impaired aerobic capacity in older HF patients.

Attenuation of quorum sensing mediated virulence factors production and biofilm formation in Pseudomonas aeruginosa PAO1 by Colletotrichum gloeosporioides HM3.

Signal dependent microbial communication in Pseudomonas aeruginosa PAO1 is a typical phenomenon mediated by acyl homo-serine lactone molecules that helps in developing biofilm and enhance antibiotic resistance. Microbial sources provide insight to the hidden treasure of secondary metabolites, and these structurally diversified chemical motifs can be used as antimicrobial and anti-infective agents. In the present study, endophytic fungus, Colletotrichum gloeosporioides HM3 isolated from Carica papaya leaves was explored for anti-infective potential against P. aeruginosa PAO1. The crude extract of C. gloeosporioides HM3 displayed bacteriostatic effect on P. aeruginosa PAO1 growth at 750 µg/ml concentration. A significant decline was observed in the production of quorum sensing regulated virulence factors, i.e. 56.32%, 62.54%, and 66.67% of pyocyanin, chitinase, and elastase enzyme, respectively. A drastic reduction in pathogenic determinant behaviour after treatment with crude extract of C. gloeosporioides HM3 i.e. EPS, rhamnolipid, and HCN production was noted. Light microscopy and CLSM analysis revealed that fungal extract treatment has reduced bacterial ability to form dense biofilm architecture. In silico analysis demonstrated the binding efficiency of bioactive compound, 4-(2,3-dimethoxybenzylidene)-3-methyl-1-(4-nitrophenyl)-2-pyrazolin-5-one, which is equipotent to the natural ligand and displayed a docking score of -5.436 kcal/mol with QS transcriptional regulator (LasR). Whereas the compound Acetamide, n-[tetrahydro-3-(phenylmethyl) thieno [3,4-d]thiazol-2 (3 h)-ylidene]-, s,s-dioxide exhibits a docking score of -4.088 kcal/mol (LasR) and -1.868 kcal/mol (RhlR) with cognate receptor proteins. Henceforth, the research report suggests C. gloeosporioides HM3 derived metabolites could be considered as a potential inhibitors of QS regulated virulence factors and biofilm production in P. aeruginosa PAO1.

Flow cytometric evaluation of platelet-leukocyte conjugate stability over time: methodological implications of sample handling and processing.

Platelet activation and subsequent aggregation is a vital component of atherothrombosis resulting in acute myocardial infarction. Therefore, quantifying platelet aggregation is a valuable measure for elucidating the pathogenesis of acute coronary syndromes (ACS). Circulating platelet-monocyte conjugates (PMC) as determined by flow cytometry (FCM) are an important measure of in vivo platelet aggregation. However, the influence of sample handling on FCM measurement of PMC is not well-studied. The changes in FCM measurement of PMC with variation in sample handling techniques were evaluated. The stability of PMC concentrations over time with changes in fixation and immunolabeling intervals was assessed. The effect of Time-to-Fix and Time-to-Stain on FCM PMC measurements was investigated in five healthy volunteers. Time-to-Fix (i.e., interval between phlebotomy and sample fixation) was performed at 3, 30, and 60 min. Time-to-Stain (i.e., time of fixed sample storage to staining) was performed at 1, 24, and 48 h. Increasing Time-to-Stain from 1 to 24 or 48 h resulted in lower PMC measures (p < 0.0001). A statistically significant difference in PMC measurement with increasing Time-to-Fix was not observed (p < 0.41). Postponement of sample staining has deleterious effects on the measurement of PMC via FCM. Delays in immunolabeling of fixed samples compromised measurement of PMC by 30% over the first 24 h. Staining/FCM should be completed within an hour of collection.

Fungal diversity notes 1387-1511: taxonomic and phylogenetic contributions on genera and species of fungal taxa.

This article is the 13th contribution in the Fungal Diversity Notes series, wherein 125 taxa from four phyla, ten classes, 31 orders, 69 families, 92 genera and three genera incertae sedis are treated, demonstrating worldwide and geographic distribution. Fungal taxa described and illustrated in the present study include three new genera, 69 new species, one new combination, one reference specimen and 51 new records on new hosts and new geographical distributions. Three new genera, Cylindrotorula (Torulaceae), Scolecoleotia (Leotiales genus incertae sedis) and Xenovaginatispora (Lindomycetaceae) are introduced based on distinct phylogenetic lineages and unique morphologies. Newly described species are Aspergillus lannaensis, Cercophora dulciaquae, Cladophialophora aquatica, Coprinellus punjabensis, Cortinarius alutarius, C. mammillatus, C. quercoflocculosus, Coryneum fagi, Cruentomycena uttarakhandina, Cryptocoryneum rosae, Cyathus uniperidiolus, Cylindrotorula indica, Diaporthe chamaeropicola, Didymella azollae, Diplodia alanphillipsii, Dothiora coronicola, Efibula rodriguezarmasiae, Erysiphe salicicola, Fusarium queenslandicum, Geastrum gorgonicum, G. hansagiense, Helicosporium sexualis, Helminthosporium chiangraiensis, Hongkongmyces kokensis, Hydrophilomyces hydraenae, Hygrocybe boertmannii, Hyphoderma australosetigerum, Hyphodontia yunnanensis, Khaleijomyces umikazeana, Laboulbenia divisa, Laboulbenia triarthronis, Laccaria populina, Lactarius pallidozonarius, Lepidosphaeria strobelii, Longipedicellata megafusiformis, Lophiotrema lincangensis, Marasmius benghalensis, M. jinfoshanensis, M. subtropicus, Mariannaea camelliae, Melanographium smilaxii, Microbotryum polycnemoides, Mimeomyces digitatus, Minutisphaera thailandensis, Mortierella solitaria, Mucor harpali, Nigrograna jinghongensis, Odontia huanrenensis, O. parvispina, Paraconiothyrium ajrekarii, Parafuscosporella niloticus, Phaeocytostroma yomensis, Phaeoisaria synnematicus, Phanerochaete hainanensis, Pleopunctum thailandicum, Pleurotheciella dimorphospora, Pseudochaetosphaeronema chiangraiense, Pseudodactylaria albicolonia, Rhexoacrodictys nigrospora, Russula paravioleipes, Scolecoleotia eriocamporesi, Seriascoma honghense, Synandromyces makranczyi, Thyridaria aureobrunnea, Torula lancangjiangensis, Tubeufia longihelicospora, Wicklowia fusiformispora, Xenovaginatispora phichaiensis and Xylaria apiospora. One new combination, Pseudobactrodesmium stilboideus is proposed. A reference specimen of Comoclathris permunda is designated. New host or distribution records are provided for Acrocalymma fici, Aliquandostipite khaoyaiensis, Camarosporidiella laburni, Canalisporium caribense, Chaetoscutula juniperi, Chlorophyllum demangei, C. globosum, C. hortense, Cladophialophora abundans, Dendryphion hydei, Diaporthe foeniculina, D. pseudophoenicicola, D. pyracanthae, Dictyosporium pandanicola, Dyfrolomyces distoseptatus, Ernakulamia tanakae, Eutypa flavovirens, E. lata, Favolus septatus, Fusarium atrovinosum, F. clavum, Helicosporium luteosporum, Hermatomyces nabanheensis, Hermatomyces sphaericoides, Longipedicellata aquatica, Lophiostoma caudata, L. clematidis-vitalbae, Lophiotrema hydei, L. neoarundinaria, Marasmiellus palmivorus, Megacapitula villosa, Micropsalliota globocystis, M. gracilis, Montagnula thailandica, Neohelicosporium irregulare, N. parisporum, Paradictyoarthrinium diffractum, Phaeoisaria aquatica, Poaceascoma taiwanense, Saproamanita manicata, Spegazzinia camelliae, Submersispora variabilis, Thyronectria caudata, T. mackenziei, Tubeufia chiangmaiensis, T. roseohelicospora, Vaginatispora nypae, Wicklowia submersa, Xanthagaricus necopinatus and Xylaria haemorrhoidalis. The data presented herein are based on morphological examination of fresh specimens, coupled with analysis of phylogenetic sequence data to better integrate taxa into appropriate taxonomic ranks and infer their evolutionary relationships.

Efficacy and reusability of mixed-phase TiO2-ZnO nanocomposites for the removal of estrogenic effects of 17ß-Estradiol and 17α-Ethinylestradiol from water.

Photocatalytic removal of estrogenic compounds (ECs), 17ß-estradiol (E2), and 17α-ethinylestradiol (EE2) were assessed using a TiO2-ZnO nanocomposite (NC) over a range of initial EC concentration (Co; 10 mg/L - 0.05 mg/L). Photocatalytic removal was evaluated under UV and visible irradiation using 10 mg/L NC over 240 min duration. After 240 min, analysis using GCxGC TOF MS revealed 100% transformation at Co ≤ 1 mg/L and ≥25% transformation at Co ≤ 10 mg/L under visible irradiation. Degradation was accompanied by breakdown of the fused ring structure of E2, generating smaller molecular weight by-products which were subsequently mineralized as revealed through TOC removal. With UV photocatalysis, ~30% and ~20% mineralization was attained for E2 and EE2, respectively, for Co of 10 mg/L. Under visible irradiation, ~25% and ~10% mineralization was achieved for E2 and EE2, respectively. Estrogenicity variation was estimated using the E-screen assay conducted with estrogen receptor-positive MCF-7 breast cancer cells. Complete removal of estrogenicity of ECs was confirmed after 240 min of photocatalysis under UV and visible irradiation. FTIR spectroscopy-based analysis of the NC after E2 photocatalysis revealed the presence of sorbed organics. Desorption, followed by GC × GC TOF-MS analysis revealed these organics as by-products of photocatalysis. Desorption of sorbed organics followed by recalcination at 600 °C for 1 h regenerated the active sites on the NC, enabling its efficient reuse for 3 cycles under visible irradiation without loss in activity.

Short term response of plankton community to nutrient enrichment in central eastern Arabian Sea: Elucidation through mesocosm experiments.

Oligotrophic waters (OW), generally favour longer food chain facilitated by the microbial loop. In such ecosystems, physical mixing (e.g. upwelling, and winter convection) inject nutrients and propagules from subsurface to the photic zone. Such events are expected to alter the food chain through shifts in the plankton community. Mesocosm experiments were carried out to evaluate the influence of nutrient enrichment from the deep (100-150 m) on the surface plankton community for the first time in the Arabian Sea, through custom-designed enclosures in OW of the central-eastern Arabian Sea (CEAS). Surface water was characterized by low nutrients and phytoplankton biomass (chlorophyll-a of <0.2 µg m-3) and upon nutrient enrichment yielded differing response. Higher abundance of picophytoplankton, bacteria and protists was noticed at a depth of ~100 m than at surface. The inoculation of such a population to the surface, resulted in a significant enhancement of autotrophic (picophytoplankton) and heterotrophic (bacteria and protists) populations. However, significant changes in the abundance of larger plankton was not evident till three days of incubation. Even though autotrophic picophytoplankton responded positively, a distinct increase in chlorophyll-a was not evident. This study points out that the lack of sufficient viable microphytoplankton propagules, neither at the surface nor at the depth (inoculum) are the possible reasons for the lack of their distinct positive response. These experiments suggest the dominance of microbial community response to physical mixing in the OW regions of the Arabian Sea and the importance of propagule diversity. The insights from this experiment will serve as a precursor for appropriate modifications in ocean modelling and forecasting studies and help in building global environmental management tools.

Anti-quorum sensing and antibiofilm activities of Blastobotrys parvus PPR3 against Pseudomonas aeruginosa PAO1.

The bacterial cell communication also termed as Quorum sensing (QS) system was involved in the expression of several virulence traits during Pseudomonas infection. The attenuating of this bacterial cell communication system is an attractive approach for the management of bacterial infections without the complication of resistance development. In this respect, the marine environment has gained significant attention due to its biodiversity and as a source of novel bioactive compounds. The present study aimed to screening effective QS inhibitors from marine associated fungal species for QS inhibitors. Twelve morphologically distinct fungal isolates were isolated from the wood of Avicennia marina from marine ecosystem. The anti-QS potential of fungal crude extract from was investigated in biosensor strain and test bacterium, Chromobacterium violaceum and Pseudomonas aeruginosa PAO1, respectively. Promising anti-QS activity was observed in the crude extract of one of the fungal isolate and identified by molecular characterization using internal transcribed spacer (ITS) region as Blastobotrys parvus PPR3. The anti-virulence and antibiofilm effects of ethyl acetate fractions from PPR3 against P. aeruginosa PAO1 were evaluated. The fungal metabolites responsible for the anti-QS activity of fungal crude extract was identified using gas chromatography-mass spectrometry (GC-MS). Furthermore, molecular docking studies were performed to understand the interaction of bioactive compounds with as receptors of P. aeruginosa PAO1. The crude extract of PPR3 showed reduction in different virulence traits of P. aeruginosa PAO1 such as production of pyocyanin, elastase, protease, chitinase, swimming and swarming motility, biofilm formation, exopolysaccharide production and alginate production at different sub-MIC concentrations. Interaction of bioactive metabolites with LasR and RhlR receptors of P. aeruginosa PAO1 was reported. The findings of the present study suggested that metabolites of B. parvus PPR3 interfere with QS system of P. aeruginosa PAO1 and alters the production of virulence factors.

Change in matrix metalloproteinase 2, 3, and 9 levels at the time of and after acute atherothrombotic myocardial infarction.

Elevated measures of matrix metalloproteinases (MMPs) are associated with acute myocardial infarction (MI), but it is not known how long these changes persist post-MI or if these measures differ between atherothrombotic versus non-atherothrombotic MI. MMPs-2, 3, and 9 were measured in 80 subjects with acute MI (atherothrombotic and non-atherothrombotic MI) or stable coronary artery disease (CAD). Measurements were made at, the time of acute MI, and > 3-month following acute MI (quiescent phase). Outcome measures were compared between groups and between time of acute MI and quiescent post-MI follow-up using Wilcoxon's and repeated measures analysis of variance. Forty-nine subjects met the criteria for acute MI with clearly defined atherothrombotic (n = 22) and non-atherothrombotic (n = 12) subsets. Fifteen subjects met criteria for stable CAD. MMP-3 was higher in acute MI versus stable CAD subjects at the time of acute MI: (453 vs. 217 pg/mL, p = 0.010) but not at quiescent phase follow-up (p > 0.05). MMP-9 was higher in acute MI versus stable CAD subjects at the time of acute MI: (412 vs. 168 pg/mL, p = 0.002) but not at the quiescent phase follow-up (p > 0.05). MMP-9 was higher at the time of acute MI versus quiescent phase follow-up in acute MI (412 vs. 213 pg/mL, p = 0.001) and atherothrombotic MI specifically (458 vs. 212 pg/mL, p = 0.001). No difference in MMP-2, 3, or 9 was observed between atherothrombotic versus non-atherothrombotic MI subgroups. MMPs-3 and 9 are significantly elevated in acute MI verses stable CAD subjects at time of acute MI but not different at quiescent phase follow-up. MMP-9 is elevated at the time of acute MI and specifically in acute atherothrombotic MI at time of MI versus quiescent phase follow-up.

Phomopsis tersa as Inhibitor of Quorum Sensing System and Biofilm Forming Ability of Pseudomonas aeruginosa.

Endophytic fungi provide rich reservoir for novel antimicrobial compounds. An endophytic fungus, from Carica papaya plant identified as Phomopsis tersa, was investigated for attenuating the quorum sensing mediated pathogenicity of Pseudomonas aeruginosa PAO1. Crude extract of P. tersa was found to reduce the production of redox-active pigments-pyocyanin and pyoverdine in P. aeruginosa PAO1 by 92.46% and 71.55%, respectively at sub-MIC concentration of 900 µg/mL. In addition, the crude extract was also able to inhibit the expression of virulence factors involved in biofilm formation: exopolysaccharide (72.21%) and alginate (72.50%). Secretion of cell-lytic enzymes was also found to be reduced: chitinase by 79.73% and elastase by 74.30%. 3-Isobutylhexahydropyrrolo[1,2-a]pyrazine-1,4-dione identified from GC-MS analysis, displayed favorable molecular interactions with P. aeruginosa transcriptional regulators, LasR and RhlR with good docking scores of - 6.873 kJ/mol and - 6.257 kJ/mol, respectively. The study thus reveals the potential use of P. tersa for discovering drugs against infectious pathogens.

The evolution of apical hypertrophic cardiomyopathy: Development of mid-ventricular obstruction and apical aneurysm 11 years after initial diagnosis.

Asian hypertrophic cardiomyopathy (AHCM) is a rare variant of hypertrophic cardiomyopathy (HCM) that is more prevalent in the Asian population. There is significant overlap between AHCM, mid-cavitary obstruction, and apical aneurysms. Although more benign compared to HCM, the course of AHCM is not clearly defined. We present an interesting case of an African American male with known AHCM who develops symptomatic mid-cavitary obstruction and apical aneurysm 11 years after initial diagnosis.

Aspergillus ochraceopetaliformis SSP13 modulates quorum sensing regulated virulence and biofilm formation in Pseudomonas aeruginosa PAO1.

Pseudomonas aeruginosa is an opportunistic nosocomial pathogen causing the majority of acute and persistent infections in human beings. The ability to form biofilm adds a new dimension to its resistance to conventional therapeutic agents. In the present study, down-regulation of quorum sensing regulated virulence and biofilm development resulting from exposure to Aspergillus ochraceopetaliformis SSP13 extract was investigated. The in vitro results inferred impairment in the production of LasA protease, LasB elastase, chitinase, pyocyanin, exopolysaccharides and rhamnolipids. In addition, motility and biofilm formation by P. aeruginosa PAO1 was significantly altered. The in vitro results were further supported by molecular docking studies of the metabolites obtained from GC-MS analysis depicting the quorum sensing attenuation by targeting the receptor proteins LasR and RhlR. The in vitro and in silico studies suggested new avenues for the development of bioactive metabolites from A. ochraceopetaliformis SSP13 extract as potential anti-infective agents.

A curious case of an absent left atrial appendage.

The left atrial appendage (LAA) in the setting of non-valvular atrial fibrillation (NVAF) is the predominant location for intracardiac thrombus formation. An absent LAA is a very rare congenital cardiac anomaly. We present a case of a 79-year-old female with NVAF, high CHADS2VASC2 score, and high bleeding risk who presented for elective Watchman™ left atrial appendage closure device implant. A pre-procedural transesophageal echocardiography showed an absent LAA. This finding was confirmed with cardiac computed tomography and a left atrial angiogram. The patient was discharged on medical therapy with close outpatient follow-up.

The dehydrogenation mechanism during the incubation period in nanocrystalline MgH2.

The dehydrogenation mechanism during the incubation period in nanocrystalline MgH2 (low α: converted metal fraction and dα/dt) and the reasons for the occurrence of the incubation period at 320, 350, and 400 °C were investigated. Pre-existing Mg crystallites can enhance Mg nucleation during the incubation period, as suggested by the estimated activation energy for nucleation (12 ± 2 kJ per mol H). The released H-atoms enter MgH2 as interstitials, as indicated by the MgH2 unit-cell contraction, resulting in increased equatorial Mg-H bond length, decreased charge-density distribution in the interstitial region, as observed from the charge-density maps, and decreased H-H distance in the {001} plane up to the midway of the incubation period. Eventually, hydrogen vacancies are created, as indicated by the red shift in the Eg and A1g peaks of Raman spectra. The high estimated activation energy for the growth of Mg (209 ± 8 kJ per mol H) renders it difficult and explains the reason for the presence of an incubation period.

River discharge as a major driving force on spatial and temporal variations in zooplankton biomass and community structure in the Godavari estuary India.

Variability in horizontal zooplankton biomass distribution was investigated over 13 months in the Godavari estuary, along with physical (river discharge, temperature, salinity), chemical (nutrients, particulate organic matter), biological (phytoplankton biomass), and geological (suspended matter) properties to examine the influencing factors on their spatial and temporal variabilities. The entire estuary was filled with freshwater during peak discharge period and salinity near zero, increased to ~ 34 psu during dry period with relatively high nutrient levels during former than the latter period. Due to low flushing time (< 1 day) and high suspended load (> 500 mg L-1) during peak discharge period, picoplankton (cyanophyceae) contributed significantly to the phytoplankton biomass (Chl-a) whereas microplankton and nanoplankton (bacillariophyceae, and chlorophyceae) during moderate and mostly microplankton during dry period. Zooplankton biomass was the lowest during peak discharge period and increased during moderate followed by dry period. The zooplankton abundance was controlled by dead organic matter during peak discharge period, while both phytoplankton biomass and dead organic matter during moderate discharge and mostly phytoplankton biomass during dry period. This study suggests that significant modification of physico-chemical properties by river discharge led to changes in phytoplankton composition and dead organic matter concentrations that alters biomass, abundance, and composition of zooplankton in the Godavari estuary.