Molekularna karakterizacija iz psa izdvojenog izolata bakterije Escherichia coli koji proizvodi prošireni spektrum beta-laktamaza i New Delhi metalo-beta-laktamazu-1 (blaNDM1) - prikaz slučaja

In this article, we report the molecular characterization of extensively drug resistant (XDR), extended spectrum, class C beta-lactamases and NDM-1 carbapenemase producing E. coli, isolated from the scrotal fluid of a 3-year-old male dog. In an antibiotic susceptibility test the E. coli isolate was susceptible only to tigecycline and resistant to all clinically applicable antibiotics tested in the study. The minimum inhibitory concentration (MIC) of meropenem, cefotaxime and cefepime was 256, 128 and 64 µg/mL, respectively. On genotypic screening by PCR, the isolate was positive for blaNDM, blaCTX-M, blaAmpC, blaTEM and sul1 genes. The isolate was a ESBL, AmpC and metalo beta-lactamase producer. On molecular pathotyping, the isolate harbored the Shiga toxin producing gene (Stx2). The extensively drug resistant, carbapenem resistant and ESBL producing E. coli constitutes a major public health concern, since there is a great chance of dissemination of resistance genes to humans due to the close association of humans and companion animals. To the best of our knowledge, this is the first report of blaNDM1 isolated from a dog in India.U radu se izvješćuje o molekularnoj karakterizaciji bakterije E. coli izdvojene iz skrotalne tekućine psa, iznimno otporne na antibiotike širokog spektra, koja proizvodi klasu C beta-laktamaza i NDM-1 karbapenemazu. Pas je bio u dobi od od tri godine. Izolat E. coli bio je osjetljiv samo na tigeciklin, a otporan na sve antibiotike primjenjivane u kliničkoj praksi. Minimalna inhibicijska koncentracija (MIC) za meropenem iznosila je 256, cefotaksim 128 i cefepim 64 µg/mL. Pretragom genotipa lančanom reakcijom polimerazom izolat je bio pozitivan na gene blaNDM, blaCTX-M, blaAmpC, blaTEM i sul1. Proizvodio je ESBL, AmpC i metalo-beta-laktamazu. Molekularnom patotipizacijom dokazano je da posjeduje gen za shiga-toksin (Stx2). E. coli otporna na karbapenem, koja proizvodi beta-laktamaze širokog spektra, velika je prijetnja za javno zdravstvo s obzirom na to da postoji velika mogućnost prijenosa E. coli s genom za rezistenciju na ljude u bliskom dodiru s kućnim ljubimcima. Ovo je prvo izvješće o blaNDM1 dokazanom u psa u Indiji

Sirtuin 6 inhibition protects against glucocorticoid-induced skeletal muscle atrophy by regulating IGF/PI3K/AKT signaling

Chronic activation of stress hormones such as glucocorticoids leads to skeletal muscle wasting in mammals. However, the molecular events that mediate glucocorticoid-induced muscle wasting are not well understood. Here, we show that SIRT6, a chromatin-associated deacetylase indirectly regulates glucocorticoid-induced muscle wasting by modulating IGF/PI3K/AKT signaling. Our results show that SIRT6 levels are increased during glucocorticoid-induced reduction of myotube size and during skeletal muscle atrophy in mice. Notably, overexpression of SIRT6 spontaneously decreases the size of primary myotubes in a cell-autonomous manner. On the other hand, SIRT6 depletion increases the diameter of myotubes and protects them against glucocorticoid-induced reduction in myotube size, which is associated with enhanced protein synthesis and repression of atrogenes. In line with this, we find that muscle-specific SIRT6 deficient mice are resistant to glucocorticoid-induced muscle wasting. Mechanistically, we find that SIRT6 deficiency hyperactivates IGF/PI3K/AKT signaling through c-Jun transcription factor-mediated increase in IGF2 expression. The increased activation, in turn, leads to nuclear exclusion and transcriptional repression of the FoxO transcription factor, a key activator of muscle atrophy. Further, we find that pharmacological inhibition of SIRT6 protects against glucocorticoid-induced muscle wasting in mice by regulating IGF/PI3K/AKT signaling implicating the role of SIRT6 in glucocorticoid-induced muscle atrophy.Fil: Mishra, Sneha. No especifíca;Fil: Cosentino, Claudia. Harvard Medical School; Estados UnidosFil: Tamta, Ankit Kumar. No especifíca;Fil: Khan, Danish. No especifíca;Fil: Srinivasan, Shalini. No especifíca;Fil: Ravi, Venkatraman. No especifíca;Fil: Abbotto, Elena. Università degli Studi di Genova; ItaliaFil: Arathi, Bangalore Prabhashankar. No especifíca;Fil: Kumar, Shweta. No especifíca;Fil: Jain, Aditi. No especifíca;Fil: Ramaian, Anand S.. No especifíca;Fil: Kizkekra, Shruti M.. No especifíca;Fil: Rajagopal, Raksha. No especifíca;Fil: Rao, Swathi. No especifíca;Fil: Krishna, Swati. No especifíca;Fil: Asirvatham Jeyaraj, Ninitha. Indian Institute of Technology; IndiaFil: Haggerty, Elizabeth R.. Harvard Medical School; Estados UnidosFil: Silberman, Dafne Magalí. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Kurland, Irwin J.. No especifíca;Fil: Veeranna, Ravindra P.. No especifíca;Fil: Jayavelu, Tamilselvan. No especifíca;Fil: Bruzzone, Santina. Università degli Studi di Genova; ItaliaFil: Mostoslavsky, Raul. Harvard Medical School; Estados UnidosFil: Sundaresan, Nagalingam R.. No especifíca

An ab initio and AIM investigation into the hydration of 2-thioxanthine

<p>Abstract</p> <p>Background</p> <p>Hydration is a universal phenomenon in nature. The interactions between biomolecules and water of hydration play a pivotal role in molecular biology. 2-Thioxanthine (2TX), a thio-modified nucleic acid base, is of significant interest as a DNA inhibitor yet its interactions with hydration water have not been investigated either computationally or experimentally. Here in, we reported an <it>ab initio </it>study of the hydration of 2TX, revealing water can form seven hydrated complexes.</p> <p>Results</p> <p>Hydrogen-bond (H-bond) interactions in 1:1 complexes of 2TX with water are studied at the MP2/6-311G(d, p) and B3LYP/6-311G(d, p) levels. Seven 2TX^...H₂O hydrogen bonded complexes have been theoretically identified and reported for the first time. The proton affinities (PAs) of the O, S, and N atoms and deprotonantion enthalpies (DPEs) of different N-H bonds in 2TX are calculated, factors surrounding why the seven complexes have different hydrogen bond energies are discussed. The theoretical infrared and NMR spectra of hydrated 2TX complexes are reported to probe the characteristics of the proposed H-bonds. An improper blue-shifting H-bond with a shortened C-H bond was found in one case. NBO and AIM analysis were carried out to explain the formation of improper blue-shifting H-bonds, and the H-bonding characteristics are discussed.</p> <p>Conclusion</p> <p>2TX can interact with water by five different H-bonding regimes, N-H^...O, O-H^...N, O-H^...O, O-H^...S and C-H^...O, all of which are medium strength hydrogen bonds. The most stable H-bond complex has a closed structure with two hydrogen bonds (N(7)-H^...O and O-H^...O), whereas the least stable one has an open structure with one H-bond. The interaction energies of the studied complexes are correlated to the PA and DPE involved in H-bond formation. After formation of H-bonds, the calculated IR and NMR spectra of the 2TX-water complexes change greatly, which serves to identify the hydration of 2TX.</p

Heterogeneous treatment effects of therapeutic-dose heparin in patients hospitalized for COVID-19

Importance Randomized clinical trials (RCTs) of therapeutic-dose heparin in patients hospitalized with COVID-19 produced conflicting results, possibly due to heterogeneity of treatment effect (HTE) across individuals. Better understanding of HTE could facilitate individualized clinical decision-making. Objective To evaluate HTE of therapeutic-dose heparin for patients hospitalized for COVID-19 and to compare approaches to assessing HTE. Design, Setting, and Participants Exploratory analysis of a multiplatform adaptive RCT of therapeutic-dose heparin vs usual care pharmacologic thromboprophylaxis in 3320 patients hospitalized for COVID-19 enrolled in North America, South America, Europe, Asia, and Australia between April 2020 and January 2021. Heterogeneity of treatment effect was assessed 3 ways: using (1) conventional subgroup analyses of baseline characteristics, (2) a multivariable outcome prediction model (risk-based approach), and (3) a multivariable causal forest model (effect-based approach). Analyses primarily used bayesian statistics, consistent with the original trial. Exposures Participants were randomized to therapeutic-dose heparin or usual care pharmacologic thromboprophylaxis. Main Outcomes and Measures Organ support–free days, assigning a value of −1 to those who died in the hospital and the number of days free of cardiovascular or respiratory organ support up to day 21 for those who survived to hospital discharge; and hospital survival. Results Baseline demographic characteristics were similar between patients randomized to therapeutic-dose heparin or usual care (median age, 60 years; 38% female; 32% known non-White race; 45% Hispanic). In the overall multiplatform RCT population, therapeutic-dose heparin was not associated with an increase in organ support–free days (median value for the posterior distribution of the OR, 1.05; 95% credible interval, 0.91-1.22). In conventional subgroup analyses, the effect of therapeutic-dose heparin on organ support–free days differed between patients requiring organ support at baseline or not (median OR, 0.85 vs 1.30; posterior probability of difference in OR, 99.8%), between females and males (median OR, 0.87 vs 1.16; posterior probability of difference in OR, 96.4%), and between patients with lower body mass index (BMI 90% for all comparisons). In risk-based analysis, patients at lowest risk of poor outcome had the highest propensity for benefit from heparin (lowest risk decile: posterior probability of OR >1, 92%) while those at highest risk were most likely to be harmed (highest risk decile: posterior probability of OR <1, 87%). In effect-based analysis, a subset of patients identified at high risk of harm (P = .05 for difference in treatment effect) tended to have high BMI and were more likely to require organ support at baseline. Conclusions and Relevance Among patients hospitalized for COVID-19, the effect of therapeutic-dose heparin was heterogeneous. In all 3 approaches to assessing HTE, heparin was more likely to be beneficial in those who were less severely ill at presentation or had lower BMI and more likely to be harmful in sicker patients and those with higher BMI. The findings illustrate the importance of considering HTE in the design and analysis of RCTs. Trial Registration ClinicalTrials.gov Identifiers: NCT02735707, NCT04505774, NCT04359277, NCT0437258

Effect of plant growth regulators (PGRs) on micropropagation of a vulnerable and high value medicinal plant Hedychium spicatum

A complete micropropagation protocol was developed by applying different plant growth regulators (PGRs) of a vulnerable and high value aromatic medicinal plant, Hedychium spicatum. Three cytokinins, 6-benzyladenine (BA), kinetin (KN) and thidiazuron (TDZ) were used and among these, the lower concentration of TDZ (1.0 μM) was found to be the most effective treatment in relation to induction of high frequency shoot multiplication (83.33%), number of shoots per explant (3.86 shoots) and average number of shoots per flask (19.33 shoots). Indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) and α- naphthalene acetic acid (NAA) were the used auxins in this study for in-vitro rooting. Among these used auxins, the lower concentration of IBA (2.5 μM) was the prominent plant growth regulator regarding in vitro rooting. Well rooted and healthy plantlets were obtained after 2 months of hardening and transferred to the field (1990 m) with 90.0% survival. On the basis of available literature, this is the first and significant study regarding the comparative effect of different PGRs on in-vitro propagation study of H. spicatum. This significant study could be useful for large scale propagation and ex-situ conservation of this vulnerable Himalayan species.Key words: Cytokinins, thidiazuron, shoot multiplication, in-vitro propagation, ex-situ conservation