Abstract Background Limited therapeutic options are available for the treatment of multidrug resistant (MDR) organisms. Plazomicin (PLZ) is an aminoglycoside developed to overcome common aminoglycoside-resistance mechanisms. We evaluated the activity of PLZ and comparators against Enterobacterales isolates collected in 2018-2019 carrying genes encoding ESBLs, carbapenemases, and AMEs. Methods Among 3,899 Enterobacterales isolates from US hospitals susceptibility (S) tested using reference broth microdilution method, 619 isolates from selected species displaying elevated MIC values for cephalosporins, carbapenems and/or resistance (CLSI criteria) to amikacin (AMK), gentamicin (GEN) and tobramycin (TOB) were submitted to whole genome sequencing for detection of resistance genes. Results Most isolates producing ESBLs (n= 418) carried blaCTX-M (n= 386). The activity of PLZ (99.3% susceptible [S]) was comparable to that of colistin and higher than other comparators against ESBL isolates (Figure). AMK inhibited 96.4% of the isolates and GEN and TOB inhibited 57.9% and 43.5%, respectively. Only 34 isolates produced carbapenemases, including 19 KPC-2, 10 KPC-3, 1 each with VIM-1, OXA-181, NDM-5 and KPC-2-like plus 1 isolate carrying the genes encoding NDM-1 and OXA-232. These isolates displayed higher resistance rates to comparators and only PLZ, and tigecycline inhibited >90% of these isolates. AMK and GEN inhibited 67.6% and 55.9% of these isolates, respectively. PLZ was active against 97.7% of isolates carrying AME genes (n= 306) that carried aac(6’)-Ib-cr (n =177), aac(3)-IIa (n = 159) and aac(3)-IId (n =81), among others. Most of these isolates were resistant to GEN and TOB (only 10.8-14.1% S), but 92.8% were S to AMK. Three K. pneumoniae isolates carried 16S rRNA methyltransferases, 1 armA (also harboring NDM-1) and 2 rmtB1. Conclusion The activity of PLZ against Enterobacteriaceae isolates carrying AMEs, ESBLs, and carbapenemases was greater than the activity of other aminoglycosides tested and comparable to those of tigecycline and colistin against carbapenemase-producing organisms. Isolates carrying genes encoding ESBLs, AMEs and carbapenemases are usually MDR and PLZ had activity against these organisms collected in the US. Figure 1 Disclosures Mariana Castanheira, PhD, 1928 Diagnostics (Research Grant or Support)A. Menarini Industrie Farmaceutiche Riunite S.R.L. (Research Grant or Support)Allergan (Research Grant or Support)Allergan (Research Grant or Support)Amplyx Pharmaceuticals (Research Grant or Support)Cidara Therapeutics (Research Grant or Support)Cidara Therapeutics (Research Grant or Support)Cipla Ltd. (Research Grant or Support)Cipla Ltd. (Research Grant or Support)Fox Chase Chemical Diversity Center (Research Grant or Support)GlaxoSmithKline (Research Grant or Support)Melinta Therapeutics, Inc. (Research Grant or Support)Melinta Therapeutics, Inc. (Research Grant or Support)Melinta Therapeutics, Inc. (Research Grant or Support)Merck (Research Grant or Support)Merck (Research Grant or Support)Merck & Co, Inc. (Research Grant or Support)Merck & Co, Inc. (Research Grant or Support)Paratek Pharma, LLC (Research Grant or Support)Pfizer (Research Grant or Support)Qpex Biopharma (Research Grant or Support) Rodrigo E. Mendes, PhD, A. Menarini Industrie Farmaceutiche Riunite S.R.L. (Research Grant or Support)Allergan (Research Grant or Support)Allergan (Research Grant or Support)Basilea Pharmaceutica International, Ltd (Research Grant or Support)Cipla Ltd. (Research Grant or Support)Department of Health and Human Services (Research Grant or Support)GlaxoSmithKline (Research Grant or Support)Melinta Therapeutics, Inc. (Research Grant or Support)Merck (Research Grant or Support)Merck (Research Grant or Support)Pfizer (Research Grant or Support) Timothy B. Doyle, Allergan (Research Grant or Support)Allergan (Research Grant or Support)Cipla Ltd. (Research Grant or Support)Melinta Therapeutics, Inc. (Research Grant or Support)Pfizer (Research Grant or Support)Qpex Biopharma (Research Grant or Support) Valerie Kantro, n/a, Cipla Ltd. (Research Grant or Support) Helio S. Sader, MD, PhD, A. Menarini Industrie Farmaceutiche Riunite S.R.L. (Research Grant or Support)Allergan (Research Grant or Support)Allergan (Research Grant or Support)Allergan (Research Grant or Support)Cipla Ltd. (Research Grant or Support)Cipla Ltd. (Research Grant or Support)Melinta (Research Grant or Support)Merck (Research Grant or Support)Merck (Research Grant or Support)Paratek Pharma, LLC (Research Grant or Support)Pfizer (Research Grant or Support) Jaideep Gogtay, n/a, Cipla Ltd. (Employee) Sandhya Das, n/a, Cipla Ltd. (Research Grant or Support)
Impaired ocular blood flow is an important risk factor in the pathogenesis of open-angle glaucoma (OAG). Studies have reported that dorzolamide 2% may be effective in improving ocular blood flow (OBF) in OAG patients. The objective of this study was to determine the efficacy of dorzolamide 2% (DORZOX, Cipla Ltd.) in improving retrobulbar blood flow in an Indian setting.The study was conducted as an interventional pilot project in 24 healthy subjects and 19 OAG patients. Baseline OBF measurements were done for all glaucoma patients with color Doppler imaging (CDI). Baseline ocular perfusion pressure (OPP) was calculated for all participants. Glaucoma patients were given dorzolamide 2% thrice daily for 12 weeks. The primary efficacy endpoints were mean changes in the CDI parameters of the retrobulbar vessels and OPP posttreatment. The secondary endpoint was mean change in the intraocular pressure (IOP) and adverse events, if any.In comparison to healthy subjects, glaucoma patients displayed significantly reduced baseline OPP (P = 0.002). Treatment with dorzolamide 2% for 12 weeks led to a significant increase in OPP (P < 0.001) and a significant increase in end diastolic velocity (EDV) in all major ophthalmic arteries like ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary artery (SPCA) (P < 0.001, P = 0.04, and P = 0.0075, respectively). A significant reduction in the intraocular pressure (IOP; P = 0.007) was observed posttreatment, with no adverse events reported.Dorzolamide 2% significantly improved parameters such as the EDV and OPP in major ophthalmic arteries. This pilot study shows promising results on using dorzolamide for treating Indian patients with OAG.
Rapid mobilization of neutrophils from vasculature to the site of bacterial/viral infections and tissue injury is a critical step in successful resolution of inflammation. The chemokine CXCL8 plays a central role in recruiting neutrophils. A characteristic feature of CXCL8 is its ability to reversibly exist as both monomers and dimers, but whether both forms exist in vivo, and if so, the relevance of each form for in vivo function is not known. In this study, using a 'trapped' non-associating monomer and a non-dissociating dimer, we show that (i) wild type (WT) CXCL8 exists as both monomers and dimers, (ii) the in vivo recruitment profiles of the monomer, dimer, and WT are distinctly different, and (iii) the dimer is essential for initial robust recruitment and the WT is most active for sustained recruitment. Using a microfluidic device, we also observe that recruitment is not only dependent on the total amount of CXCL8 but also on the steepness of the gradient, and the gradients created by different CXCL8 variants elicit different neutrophil migratory responses. CXCL8 mediates its function by binding to CXCR2 receptor on neutrophils and glycosaminoglycans (GAGs) on endothelial cells. On the basis of our data, we propose that dynamic equilibrium between CXCL8 monomers and dimers and their differential binding to CXCR2 and GAGs mediates and regulates in vivo neutrophil recruitment. Our finding that both CXCL8 monomer and dimer are functional in vivo is novel, and indicates that the CXCL8 monomer-dimer equilibrium and neutrophil recruitment are intimately linked in health and disease.
KRAS mutant lung cancers are generally refractory to chemotherapy as well targeted agents. To date, the identification of drugs to therapeutically inhibit K-RAS have been unsuccessful, suggesting that other approaches are required. We demonstrate in both a novel transgenic mutant Kras lung cancer mouse model and in human lung tumors that the inhibition of Twist1 restores a senescence program inducing the loss of a neoplastic phenotype. The Twist1 gene encodes for a transcription factor that is essential during embryogenesis. Twist1 has been suggested to play an important role during tumor progression. However, there is no in vivo evidence that Twist1 plays a role in autochthonous tumorigenesis. Through two novel transgenic mouse models, we show that Twist1 cooperates with KrasG12D to markedly accelerate lung tumorigenesis by abrogating cellular senescence programs and promoting the progression from benign adenomas to adenocarcinomas. Moreover, the suppression of Twist1 to physiological levels is sufficient to cause Kras mutant lung tumors to undergo senescence and lose their neoplastic features. Finally, we analyzed more than 500 human tumors to demonstrate that TWIST1 is frequently overexpressed in primary human lung tumors. The suppression of TWIST1 in human lung cancer cells also induced cellular senescence. Hence, TWIST1 is a critical regulator of cellular senescence programs, and the suppression of TWIST1 in human tumors may be an effective example of pro-senescence therapy.
Asthma is one of the most prevalent chronic lung diseases, affecting 235 million individuals around the world, with its related morbidity and mortality increasing steadily over the last 20 years. Exposure to the environmental allergen, house dust mite (HDM), results in airway inflammation with a variable degree of airway obstruction. Although there has been much experimental work in the past using HDM challenge models to understand mechanistic details in allergic inflammation and airway hyperresponsiveness (AHR), there has been no study on reprogramming of lung or airways mediated through epigenetic mechanisms in response to an acute HDM exposure. Male mice, 6 weeks of age, were administrated HDM extracts or saline at Days 1, 14, and 21. Exposure of mice to HDM extracts caused significant airway inflammation and increased AHR. These HDM-challenged mice also exhibited a change in global DNA methylation as compared with saline-exposed (control) mice. Next, by employing methylation-sensitive restriction fingerprinting, we identified a set of genes, showing aberrant methylation status, associated with the HDM-induced AHR. These candidate genes are known to be involved in cAMP signaling (pde4 d), Akt-signaling (akt1 s1), ion transport (tm6 sf1, pom121l2, and slc8a3), and fatty acid metabolism (acsl3). Slc8a3 and acsl3 were down-regulated, whereas pde4 d, akt1 s1, tm6 sf1, and pom121l2 were up-regulated in the mice exposed to HDM. Hence, our results suggest that HDM exposure induces a series of aberrant methylated genes that are potentially important for the development of allergic AHR.
BACKGROUNDEctopic pregnancy (EP) always demands surgical management.But with advent of modern diagnostic approaches with serum ß-HCG with high resolution TVS, now it is possible to diagnose early EP.Methotrexate (Mtx) is a promising drug to manage these patients conservatively and results are equivalent to surgery.We have shown it in our study. MATERIALS AND METHODSUncontrolled clinical trial of 63 cases of medical management of EP was undertaken.These 63 patients fulfilled the selection criteria and rest were excluded from our study.Demographic data, clinical presentation and treatment outcome were captured.All patients were managed indoor and side effect of the treatment and treatment failures were identified early by followup and then managed. RESULTSFrom January 2013 to April 2016, 63 patients with EP were successfully treated with intramuscular Mtx, only 4 patients required laparotomy.No major side effects were noted, but mild pain in abdomen.Their fertility outcomes were also preserved. CONCLUSIONSystematic Mtx injection is safer and alternative to surgical procedure of selective early EP.But prior criteria must be fulfilled and constant followup is needed to identify failure cases and complications.