Discovery of novel dihydronaphthalene-imidazole ligands as potential inhibitors of Staphylococcus aureus multidrug resistant NorA efflux pump: A combination of experimental and in silico molecular docking studies.

Overexpression of the efflux pump is a predominant mechanism by which bacteria show antimicrobial resistance (AMR) and leads to the global emergence of multidrug resistance (MDR). In this work, the inhibitory potential of library of dihydronapthyl scaffold-based imidazole derivatives having structural resemblances with some known efflux pump inhibitors (EPI) were designed, synthesized and evaluated against efflux pump inhibitor against overexpressing bacterial strains to study the synergistic effect of compounds and antibiotics. Out of 15 compounds, four compounds (Dz-1, Dz-3, Dz-7, and Dz-8) were found to be highly active. DZ-3 modulated the MIC of ciprofloxacin, erythromycin, and tetracycline by 128-fold each against 1199B, XU212 and RN4220 strains of S. aureus respectively. DZ-3 also potentiated tetracycline by 64-fold in E. coli AG100 strain. DZ-7 modulated the MIC of both tetracycline and erythromycin 128-fold each in S. aureus XU212 and S. aureus RN4220 strains. DZ-1 and DZ-8 showed the moderate reduction in MIC of tetracycline in E. coli AG100 only by 16-fold and 8-fold, respectively. DZ-3 was found to be the potential inhibitor of NorA as determined by ethidium bromide efflux inhibition and accumulation studies employing NorA overexpressing strain SA-1199B. DZ-3 displayed EPI activity at non-cytotoxic concentration to human cells and did not possess any antibacterial activity. Furthermore, molecular docking studies of DZ-3 was carried out in order to understand the possible binding sites of DZ-3 with the active site of the protein. These studies indicate that dihydronaphthalene scaffolds could serve as valuable cores for the development of promising EPIs.

The role of CT brain findings in the early diagnosis of infantile encephalitic beriberi.

BACKGROUND: Thiamine deficiency disease may occur in infants from thiamine-deficient mothers in developing countries, as well as in infants fed solely with soy-based formula. Thiamine deficiency in infants may present with acute neurological manifestations of infantile encephalitic beriberi. OBJECTIVE: To review the role of noncontrast CT brain findings in infantile encephalitic beriberi in early diagnosis. MATERIALS AND METHODS: A retrospective review of noncontrast CT scans of the brain in 21 infants with acute-onset infantile encephalitic beriberi was carried out. RESULTS: On noncontrast-enhanced CT brain, hypodense lesions were seen symmetrically in the putamen in all the babies; symmetric hypodensities were seen in the caudate nuclei in 14/21 (67%), in dorsomedial thalami/hypothalamic/subthalamic area in 4/21 (19%), and in the globi pallidi in 2/21 (9.5%) of the infants. CONCLUSION: Recognition of symmetrical hypodense lesions in the basal ganglia and medial thalami/hypothalamic/subthalamic area on noncontrast CT scan of the brain are important early features to recognize in encephalitic beriberi in at-risk infants. ADVANCES IN KNOWLEDGE: IEBB is a cause of hypodense bilateral basal ganglia and may be identified by this finding in the appropriate clinical settings.

Spectroscopic characterization and pharmacokinetic evaluation of amorphous solid dispersions of glibenclamide for bioavailability enhancement in Wistar rats.

Oral bioavailability of glibenclamide (Glb) was appreciably improved by the formation of an amorphous solid dispersion with Poloxamer-188 (P-188). Poloxamer-188 substantially enhanced the solubility and thereby the dissolution rate of the biopharmaceutics classification system (BCS) class II drug Glb and simultaneously exhibited a better stabilizing effect of the amorphous solid dispersion prepared by the solvent evaporation method. The physical state of the dispersed Glb in the polymeric matrix was characterized by differential scanning calorimetry, X-ray diffraction, scanning electron microscope and Fourier transform infrared studies. In vitro drug release in buffer (pH 7.2) revealed that the amorphous solid dispersion at a Glb-P-188 ratio of 1:6 (SDE4) improved the dissolution of Glb by 90% within 3 h. A pharmacokinetic study of the solid dispersion formulation SDE4 in Wistar rats showed that the oral bioavailability of the drug was greatly increased as compared with the market tablet formulation, Daonil®. The formulation SDE4 resulted in an AUC0-24h ~2-fold higher. The SDE4 formulation was found to be stable during the study period of 6 months.

Sonoprocessing: mechanisms and recent applications of power ultrasound in food.

There is a growing interest in using green technologies in the food industry. As a green processing technique, ultrasound has a great potential to be applied in many food applications. In this review, the basic mechanism of ultrasound processing technology has been discussed. Then, ultrasound technology was reviewed from the application of assisted food processing methods, such as assisted gelation, assisted freezing and thawing, assisted crystallization, and other assisted applications. Moreover, ultrasound was reviewed from the aspect of structure and property modification technology, such as modification of polysaccharides and fats. Furthermore, ultrasound was reviewed to facilitate beneficial food reactions, such as glycosylation, enzymatic cross-linking, protein hydrolyzation, fermentation, and marination. After that, ultrasound applications in the food safety sector were reviewed from the aspect of the inactivation of microbes, degradation of pesticides, and toxins, as well inactivation of some enzymes. Finally, the applications of ultrasound technology in food waste disposal and environmental protection were reviewed. Thus, some sonoprocessing technologies can be recommended for the use in the food industry on a large scale. However, there is still a need for funding research and development projects to develop more efficient ultrasound devices.

Simultaneous quantification of losartan potassium and its active metabolite, EXP3174, in rabbit plasma by validated HPLC-PDA.

Herein, we report a novel, accurate and cost-effective validated analytical method for the quantification of losartan potassium and its active metabolite, EXP 3174, in rabbit plasma by reversed-phase high-performance liquid chromatography. Valsartan was used as an internal standard. The method was validated as per International Conference on Harmonization guidelines. The analytes were extracted in rabbit plasma using liquid-liquid extraction technique and analyzed at 247 nm after separation through a reverse-phase C18 column. The isocratic mobile phase used is a mixture of acetonitrile, water and glacial acetic acid in the ratio of 60:40:1 v/v/v maintained at pH 3.4. All calibration curves showed a good linear relationship (r > 0.995) within the test range. Precision was evaluated by intra- and interday tests with RSDs <1.91% and accuracy showed validated recoveries of 86.20-101.11%. Based on our results, the developed method features good quantification parameters and can serve as an effective quality control method for the standardization of drugs.

Daratumumab interference in flow cytometric anti-granulocyte antibody testing can be overcome using non-human blocking antibodies.

BACKGROUND: Daratumumab (DARA), a human IgG1K monoclonal antibody targeting CD38, is used to treat refractory multiple myeloma patients. CD38 is expressed on many cell types (RBCs, granulocytes, lymphocytes, etc.), and thus, DARA can interfere with serological tests. Information regarding how DARA affects anti-granulocyte antibody (AGA) testing and optimal neutralization of DARA will help laboratories perform accurate testing. METHODS: Screening of AGA was performed by the granulocyte agglutination test (GAT) and the flow cytometric granulocyte immunofluorescence test (Flow-GIFT). Samples were tested from patients on DARA (n = 7), non-transfused blood donors (healthy controls, n = 7) and AGA reactive samples (positive controls, n = 5). Two neutralization experiments, CD38 removal with DTT and DARA epitope blockage with mouse anti-CD38, were evaluated. RESULTS: Positive reactivity of human IgG binding was observed in 5/7 DARA cases when tested by Flow-GIFT; however, all 7 cases had negative GAT agglutination results. Further studies by Flow-GIFT revealed DARA concentrations >0·63 µg/ml bound to granulocytes. DARA binding was negated by DTT though a reduced Flow-GIFT sensitivity was observed in positive control samples due to increased background detection of human IgG. Mouse anti-CD38 neutralized the detection of human IgG observed in DARA-treated patient serum without effecting controls. CONCLUSION: We established that DARA can interfere with AGA testing, leading to false positive Flow-GIFT results without causing GAT agglutination. DTT treatment increased background binding of secondary antibodies causing a decrease in Flow-GIFT sensitivity. In comparison, blockage of the DARA binding epitope using mouse anti-CD38 antibody was effective in neutralizing DARA interference while maintaining Flow-GIFT sensitivity.

Sequential multicomponent site-selective synthesis of 4-iodo and 5-iodopyrrole-3-carboxaldehydes from a common set of starting materials by tuning the conditions.

A simple and straightforward method for the synthesis of 4-iodo and 5-iodopyrrole-3-carboxaldehydes is developed from a common set of starting materials by tuning the reaction conditions. This sequential multicomponent protocol involves I2-mediated regioselective C4-iodination and aromatization of intermediate dihydropyrrole, generated through proline-catalyzed direct Mannich reaction-cyclization sequence between succinaldehyde and imines, to access 4-iodopyrroles. While aerobic oxidative aromatization of dihydropyrrole to pyrrole followed by NIS-mediated regioselective iodination furnished 5-iodopyrroles in a two-pot fashion. A series of site-selective C4/C5-iodopyrroles have been synthesized in good to high yields (up to 78%) and DFT calculations of these compounds were also performed.

Management of Intussusception in the Era of Ultrasound-Guided Hydrostatic Reduction: A 3-Year Experience from a Tertiary Care Center.

INTRODUCTION: Ultrasound-guided hydrostatic reduction (HSR) is currently the initial management tool in the treatment of intussusception. HSR is, however, confronted with failures besides there are still a number of patients who primarily undergo surgical intervention for the management of intussusception. We undertook this study to assess the efficacy of HSR and also to look for factors demanding the surgical exploration in patients with intussusception. MATERIALS AND METHODS: A total of 215 patients with intussusception from June 2014 to June 2017 were prospectively studied. HSR was carried out in 203 patients, which was successful in 187 and unsuccessful in 16. These two groups were compared using the Student's t-test. Significance was set at P < 0.05. Twelve patients undergoing surgery primarily were also assessed for the factors affecting the decision-making. RESULTS: HSR was successful in 187 and unsuccessful in 16. The failed group was more likely to have symptoms over 24 h, appearance of crescent, and ≥10-cm length on ultrasonography (USG). Two of these patients had ischemic bowel, two had ileoileal intussusception, and eight had pathological lead points, whereas no obvious cause could be identified in the rest of the four patients. Among the 12 patients who were primarily operated, four patients had peritonitis and other four patients were neonates. Laparoscopic reduction was done in four patients. CONCLUSION: HSR is a safe and effective treatment modality for intussusception. However, it is met with higher failure rates in patients with risk factors such as delayed presentation, appearance of crescent on USG, and length >10 cm. The role of HSR is also dubious in situations such as neonatal intussusception, small-bowel intussusception, and multiple intussusceptions and also in preventing the future recurrence. Such patients ought to be managed by laparotomy or where feasible by laparoscopy. Furthermore, before embarking on HSR, peritonitis and bowel ischemia should be ruled out clinically and radiologically. In the suspicious cases of bowel ischemia, USG Doppler may be helpful.

Enantio- and Diastereoselective Two-Pot Synthesis of Isoquinuclidines from Glutaraldehyde and N-Aryl Imines with DFT Calculations.

A pot-economic method for the enantio- and diastereoselective synthesis of a [2.2.2] azabicyclic isoquinuclidine system is developed. This protocol involves the proline-catalyzed direct Mannich reaction-cyclization/IBX-mediated site-selective oxidation/NaBH4-reduction sequence between glutaraldehyde and imines to generate in situ chiral 1,2-DHPs, followed by the diastereoselective Diels-Alder reaction with N-aryl maleimides furnishing isoquinuclidines in overall five steps. A variety of isoquinuclidines having five-contiguous chiral centers, including an all-carbon quaternary, were prepared with high yields (up to 78%) and excellent stereoselectivity (>50:1 dr, and up to >99:1 er). DFT calculations support the observed high stereoselective reaction outcome.

Enantiospecific Total Syntheses of (+)-Hapalindole H and (-)-12-epi-Hapalindole U.

Enantiospecific total syntheses of (+)-hapalindole H and (-)-12-epi-hapalindole U as well as the formal syntheses of (+)-hapalindole Q and (+)-12-epi-fischerindole U isothiocyanate have been described. Key steps of our approach feature expedient, highly regio- and diastereoselective Lewis acid catalyzed Friedel-Crafts reaction of indole with cyclic allylic alcohols and intramolecular reductive Heck reaction. Efficiency of the synthetic route also relies on an alkynyl aluminate complex driven regioselective nucleophilic epoxide opening from a sterically hindered site.

Contrast venography vs. microwire assisted axillary venipuncture for cardiovascular implantable electronic device implantation.

Aims: This study was conducted to compare the safety and efficacy of microwire assisted technique with contrast venography guided axillary venipuncture in patients undergoing cardiovascular implantable electronic device (CIED) implantation. Methods and results: This prospective randomized study included 212 consecutive adult patients undergoing CIED implantation at our institute between 2013 and 2015. Patients were randomized to either venography guided technique (Group I; n = 105) or microwire assisted technique (Group II; n = 107) for axillary venipuncture. In Group I axillary venogram was used as a roadmap for guiding the puncture. In Group II, a 0.014 inch hydrophilic coronary guidewire ('microwire') was introduced through the ipsilateral antecubital vein and puncture needle was aimed to hit the microwire over the first or second rib. Outcome measures including technical success rates; number of attempts to successful puncture; puncture duration; fluoroscopy times and adverse events were compared in the two groups. Overall success rates were similar in both groups (97.4% in Group I and 100% in Group II, P = 0.061). We demonstrated significantly higher first attempt success rates; shorter puncture durations and fluoroscopy times; and lower number of attempts to successful puncture with microwire assisted technique (89.3% vs. 65.6%; 36.7 ± 23.1 s vs. 67.8 ± 44.9 s; 62.4 ± 35.3 s vs. 118.9 ± 63.2 s; and 1.21 ± 0.82 vs. 2.16 ± 1.54 respectively, P < 0.001). Adverse event rates were significantly lower with microwire assisted technique (0.9% vs. 8.6%, P = 0.009). Conclusion: Microwire assisted technique is a simple, quicker, safer and more efficacious alternative to contrast venography guided axillary venipuncture.

Activating STAT6 mutations in follicular lymphoma.

Follicular lymphoma (FL) is the second most common non-Hodgkin lymphoma in the Western world. FL cell-intrinsic and cell-extrinsic factors influence FL biology and clinical outcome. To further our understanding of the genetic basis of FL, we performed whole-exome sequencing of 23 highly purified FL cases and 1 transformed FL case and expanded findings to a combined total of 114 FLs. We report recurrent mutations in the transcription factor STAT6 in 11% of FLs and identified the STAT6 amino acid residue 419 as a novel STAT6 mutation hotspot (p.419D/G, p.419D/A, and p.419D/H). FL-associated STAT6 mutations were activating, as evidenced by increased transactivation in HEK293T cell-based transfection/luciferase reporter assays, heightened interleukin-4 (IL-4) -induced activation of target genes in stable STAT6 transfected lymphoma cell lines, and elevated baseline expression levels of STAT6 target genes in primary FL B cells harboring mutant STAT6. Mechanistically, FL-associated STAT6 mutations facilitated nuclear residency of STAT6, independent of IL-4-induced STAT6-Y641 phosphorylation. Structural modeling of STAT6 based on the structure of the STAT1-DNA complex revealed that most FL-associated STAT6 mutants locate to the STAT6-DNA interface, potentially facilitating heightened interactions. The genetic and functional data combined strengthen the recognition of the IL-4/JAK/STAT6 axis as a driver of FL pathogenesis.

Measurement of Blood Flow Velocity in the Middle Cerebral Artery During Spontaneous Migraine Attacks: A Systematic Review.

OBJECTIVE: To assess the evidence for blood flow velocity changes in the middle cerebral artery during and outside of spontaneous migraine attacks. METHODS: A systematic literature search on PubMed was performed and reference lists of assessed articles to identify studies on spontaneous migraine attacks that used transcranial Doppler on the middle cerebral artery with comparisons to interictal measurements were reviewed. Studies on non-spontaneous attacks and intervention studies were excluded. RESULTS: A total of 17 original articles reporting blood flow velocity values in the middle cerebral artery using transcranial Doppler in migraine patients both with and without aura were identified. A total of 24 subgroups (ie, migraine patients without aura = 11, migraine patients with aura = 9, and mixed = 4) of migraine patients were investigated during and outside spontaneous migraine attacks in the 17 studies. No change was reported in 15 subgroups (63%), while decreased blood flow velocity was found in 8 subgroups (33%) and increased blood flow velocity was found in one study (4%). Exploratory analysis revealed that studies showing decreased blood flow velocity were carried out earlier after onset of attack (mean time, 4.1 h) compared with those showing no change (mean time, 6.0 h). CONCLUSIONS: Overall, spontaneous migraine attacks are not accompanied by blood flow velocity changes in the middle cerebral artery. However, explorative analyses on the time from attack onset to examination revealed side-specific attack-related decrease in blood flow velocity in the early, but not late phases. This is the first systematic review focusing on the flow changes in the middle cerebral artery of spontaneous migraine attacks. Future studies should focus on the early blood flow velocity changes in migraine attacks.

An Innovation in Pacemaker Lead Implantation via Persistent Left Superior Vena Cava: The "3D Alpha Curve" Stylet.

Persistent left superior vena cava (PLSVC) draining into coronary sinus is typically detected incidentally during transcatheter interventions using left subclavian venous approach. In our experience, we have encountered this anomaly on a few occasions and in all these cases we successfully implanted leads in the right ventricle (RV) by shaping the stylet into a "U-shaped" or "pigtail-shaped" curve. Herein, we report a case of an adult male who underwent successful dual-chamber pacemaker implantation via PLSVC through left axillary venous approach. In this case, we were unable to deliver the lead into RV using aforementioned stylets. As an innovation, we used a "three-dimensional alpha curve"-shaped stylet that facilitated an easy entry of pacing lead into the RV.

Cancer somatic mutations cluster in a subset of regulatory sites predicted from the ENCODE data.

BACKGROUND: Transcriptional regulation of gene expression is essential for cellular differentiation and function, and defects in the process are associated with cancer. The ENCODE project has mapped potential regulatory sites across the complete genome in many cell types, and these regions have been shown to harbour many of the somatic mutations that occur in cancer cells, suggesting that their effects may drive cancer initiation and development. The ENCODE data suggests a very large number of regulatory sites, and methods are needed to identify those that are most relevant and to connect them to the genes that they control. METHODS: Predictive models of gene expression were developed by integrating the ENCODE data for regulation, including transcription factor binding and DNase1 hypersensitivity, with RNA-seq data for gene expression. A penalized regression method was used to identify the most predictive potential regulatory sites for each transcript. Known cancer somatic mutations from the COSMIC database were mapped to potential regulatory sites, and we examined differences in the mapping frequencies associated with sites chosen in regulatory models and other (rejected) sites. The effects of potential confounders, for example replication timing, were considered. RESULTS: Cancer somatic mutations preferentially occupy those regulatory regions chosen in our models as most predictive of gene expression. CONCLUSION: Our methods have identified a significantly reduced set of regulatory sites that are enriched in cancer somatic mutations and are more predictive of gene expression. This has significance for the mechanistic interpretation of cancer mutations, and the understanding of genetic regulation.

Induced resistance to ofatumumab-mediated cell clearance mechanisms, including complement-dependent cytotoxicity, in chronic lymphocytic leukemia.

Ofatumumab (OFA), a human CD20-targeting mAb, kills B lymphocytes using the innate immune system including complement-dependent cytotoxicity (CDC). The efficacy of OFA in patients with chronic lymphocytic leukemia (CLL) is limited by drug resistance, which is not well characterized. To better understand mechanisms of resistance, we prospectively studied CLL cells isolated from blood samples collected before and after in vivo exposure to the initial dose of OFA therapy in 25 patients undergoing their first treatment for progressive CLL. As previously reported, OFA therapy rapidly decreased the absolute lymphocyte count, CD20 expression by CLL cells, and serum complement levels. We now show that after administration of the first dose of OFA, there was a modest rebound in the absolute lymphocyte count and serum complement levels, but substantial ongoing loss of CD20 expression by CLL cells. These post-OFA treatment CLL cells were highly resistant to OFA-mediated CDC but retained sensitivity to alemtuzumab-mediated CDC in vitro. Posttherapy serum OFA levels correlated inversely with both the amount of pretreatment circulating cell-bound CD20 and with the decrease in this value following treatment. In vitro OFA-mediated CDC did not predict clinical responses, and the patients with first-dose reactions to OFA did not have markers of increased complement activation in vivo. We propose that optimal efficacy of CD20- targeted therapy for CLL requires determining an mAb dose size and frequency that optimizes CLL killing without exceeding the capacity of the cytotoxic mechanisms and thus minimizes loss of CD20 expression in the surviving CLL cells.

Infantile encephalitic beriberi: magnetic resonance imaging findings.

BACKGROUND: Thiamine deficiency in infants is still encountered in developing countries. It may present with acute neurological manifestations of infantile encephalitic beriberi. OBJECTIVE: To review brain MRI findings in infantile encephalitic beriberi from a single institution. MATERIALS AND METHODS: A retrospective review of MRI scans in 22 infants with acute-onset beriberi encephalopathy was carried out. RESULTS: Hyperintense lesions on T2-weighted images were seen symmetrically in the putamen in all patients, in the caudate nuclei in 16/22 (73%), the thalami in 7/22 (32%) and the globi pallidi in 3/22 (14%) of the infants. Altered signal intensity lesions in the cerebral cortex were seen in 7/22 (32%). The mammillary bodies were seen in one infant and the periaqueductal gray matter in two. There was restricted diffusion in 14/22 (64%), and 6/8 children with no evidence of restriction had been imaged ≥10 days after presentation. MR spectroscopy showed increased lactate peak in 6/8 infants (75%). CONCLUSION: Recognition of symmetrical T2-W hyperintense lesions in the basal ganglia with restricted diffusion and prominent lactate peak may allow early diagnosis of encephalitic beriberi in at-risk infants.

Linear dialdehydes as promising substrates for aminocatalyzed transformations.

Organocatalytic domino reactions involving amine activation of carbonyl compounds have become the latest chemical technology towards the design and development of useful synthetic methods. In this direction, linear dialdehydes such as succinaldehyde, glutaraldehyde, and other homologous compounds have attracted considerable attention as suitable substrates for amine catalyzed transformations. Due to their unique structural features, dialdehydes can easily engage in recreation of cascade/tandem transformations for the synthesis of valuable natural products and drug molecules. In this review article we discuss the current scenario and potential applications of linear dialdehydes as adequate synthetic substrates for amine catalyzed transformations to access biologically important complex scaffolds.