Emergence of vanA gene among vancomycin-resistant enterococci in a tertiary care hospital of North - East India.

BACKGROUND & OBJECTIVES: Vancomycin-resistant enterococci (VRE) have become one of the most challenging nosocomial pathogens with the rapid spread of the multi-drug resistant strain with limited therapeutic options. It is a matter of concern due to its ability to transfer vancomycin resistant gene to other organisms. The present study was undertaken to determine the emergence of vancomycin-resistant enterococci and the vanA gene among the isolates in a tertiary care hospital of North-East India. METHODS: A total of 67 consecutive enterococcal isolates from different clinical samples were collected and identified by using the standard methods. Antibiogram was done by disk diffusion method and VRE was screened by the disk diffusion and vancomycin supplement agar dilution method. The minimum inhibitory concentration (MIC) value for vancomycin was determined by E-test. The VRE isolates were analyzed by PCR for vanA gene. RESULTS: A total of 54 (81%) Enterococcus faecalis and 13 (19%) E. faecium were detected among the clinical isolates and 16 (24%) were VRE. The VRE isolates were multidrug resistant and linezolid resistance was also found to be in three. MIC range to vancomycin was 16-32 µg/ml among the VRE. The vanA gene was found in nine of 16 VRE isolates. INTERPRETATION & CONCLUSIONS: Emergence of VRE and presence of vanA in a tertiary care hospital setting in North-East India indicate toward a need for implementing infection control policies and active surveillance.

Prevalence and identification of extended spectrum ß-lactamases (ESBL) in Escherichia coli isolated from a tertiary care hospital in North-East India.

Extended-spectrum ß-lactamases (ESBLs) are rapidly evolving group of ß-lactamase enzymes produced by the Gram negative bacteria. In this study, we determined the antimicrobial sensitivity pattern of Escherichia coli isolates and prevalence of TEM, SHV and CTX-M genes in ESBL positive E. coli isolated from the patients admitted to a tertiary care hospital in North-East India. A total of 85 multidrug-resistant isolates of E. coli obtained from clinical samples; urine (n = 80), sputum (n = 3), body fluid (n = 1), vaginal discharge (n = 1) were screened for resistance to third generation cephalosporins. ESBL production in resistant isolates was determined by double disk synergy test (DDST) and phenotypic confirmatory test (PCT). ESBL positive isolates were subjected to PCR for detection of TEM, SHV and CTX-M genes. Imipenem was found to be most effective against E. coli (susceptible isolates 96.47%) while ciprofloxacin was the least effective antibiotic (resistant isolates 60%). Among 33 ESBL positive isolates confirmed via PCT, preponderance in female population (60.6%) was noted. The most prevalent gene was bla(SHV) (63.04%) followed by bla(TEM) and bla(CTX-M) (60.86 and 54.34%, respectively) in ESBL positive E. coli. Most of the extensively used antibiotics, appear to be ineffective against the ever-mutating bacteria. This resistance urges cautious antimicrobial management on priority. Further, it helps in effectively designing the chemotherapeutic regimen for patients of a particular geographic area.

Synthesis, characterization, and cancer cell-selective cytotoxicity of mixed-ligand cobalt(III) complexes of 8-hydroxyquinolines and phenanthroline bases.

Transition metal complexes exhibiting selective toxicity towards a broad range of cancer types are highly desirable as potential anticancer agents. Herein, we report the synthesis, characterization, and cytotoxicity studies of six new mixed-ligand cobalt(III) complexes of general formula [Co(B)2(L)](ClO4)2 (1-6), where B is a N,N-donor phenanthroline base, namely, 1,10-phenanthroline (phen in 1, 2), dipyrido[3,2-d:2',3'-f]quinoxaline (dpq in 3, 4), and dipyrido[3,2-a:2',3'-c]phenazine (dppz in 5, 6), and L is the monoanion of 8-hydroxyquinoline (HQ in 1, 3, 5) and 5-chloro-7-iodo-8-hydroxyquinoline (CQ in 2, 4, 6). The X-ray single crystal structures of complexes 1 and 2 as PF6- salts revealed a distorted octahedral CoN5O coordination environment. Complexes demonstrated good stability in an aqueous buffer medium and in the presence of ascorbic acid as a reductant. Cytotoxicity studies using a panel of nine cancer cell lines showed that complex 6, with the dppz and CQ ligands, was significantly toxic against most cancer cell types, yielding IC50 values in the range of 2 to 14 µM. Complexes 1, 3, and 5, containing the HQ ligand, displayed lower toxicity compared to their CQ counterparts. The phenanthroline complexes demonstrated marginal toxicity towards the tested cell lines, while the dpq complexes exhibited moderate toxicity. Interestingly, all complexes demonstrated negligible toxicity towards normal HEK-293 kidney cells (IC50 > 100 µM). The observed cytotoxicity of the complexes correlated well with their lipophilicities (dppz > dpq > phen). The cytotoxicity of complex 6 was comparable to that of the clinical drug cisplatin under similar conditions. Notably, neither the HQ nor the CQ ligands alone demonstrated noticeable toxicity against any of the tested cell lines. The Annexin-V-FITC and DCFDA assays revealed that the cell death mechanism induced by the complexes involved apoptosis, which could be attributed to the metal-assisted generation of reactive oxygen species. Overall, the dppz complex 6, with its remarkable cytotoxicity against a broad range of cancer cells and negligible toxicity toward normal cells, holds significant potential for cancer chemotherapeutic applications.

Characterization of nasopharyngeal isolates of type b Haemophilus influenzae from Delhi.

BACKGROUND & OBJECTIVES: Haemophilus influenzae is an important cause of mortality and morbidity among young children in developing countries. Increasing incidence of antibiotic resistance especially production of extended spectrum beta lactamase (ESBL) has made treatment and management of H. influenzae infection more difficult. Nasopharyngeal H. influenzae isolates are excellent surrogate for determination of antibiotic resistance prevalent among invasive H. influenzae isolates. In this study, we characterized nasopharyngeal H. influenzae isolates obtained from healthy school going children in Delhi. METHODS: Nasopharyngeal H. influenzae isolates were collected from healthy school going children and subjected to serotyping, fimbrial typing and antibiogram profiling. ESBL production was recorded using phenotypic as well as molecular methods. Multi locus sequence typing (MLST) of 13 representative nasopharyngeal H. influenzae isolates was performed as per guidelines. RESULTS: A significant proportion (26 of 80, 32.5%) of nasopharyngeal isolates of H. influenzae were identified as serotype b. Fimbrial gene (hifA) was detected in 23 (28.75%) isolates. Resistance against commonly prescribed antibiotics (Amp, Tet, Chloro, Septran, Cephalexin) were observed to be high among the nasopharyngeal commensal H. influenzae. Extended spectrum beta lactamase (ESBL) production was observed in a five (6.25%) isolates by both double disk diffusion and molecular typing. MLST identified several novel alleles as well as novel sequence types. INTERPRETATION & CONCLUSIONS: Our findings showed high resistance against common antibiotics and detection of ESBL in nasopharyngeal H. influenzae isolates collected from normal healthy school going children in Delhi. Detection of H. influenzae type b capsular gene and the presence of fimbrial gene (hif A) suggest virulence potential of these isolates. Discovery of novel alleles and presence of new sequence types (STs) among nasopharyngeal H. influenzae isolates may suggest wider genetic diversity.

"Spectrum of 46 XY Disorders of Sex Development": A Hospital-based Cross-sectional Study.

BACKGROUND: Disorders of sex development (DSD) are a wide range of relatively rare conditions having diverse pathophysiology. Identification of an underlying cause can help in treating any coexisting hormone deficiencies and can help with anticipating any other immediate or long-term health concerns. OBJECTIVE: To study the clinical and biochemical profile of patients with 46 XY DSD along with androgen receptor (AR) gene mutation status in selected group of patients. METHODS: A cross-sectional study was conducted after enrolling the eligible DSD patients. Thorough elicitation of history and detailed clinical examination was done. Assays for luteinizing hormone, follicle-stimulating hormone, testosterone, dihydrotestosterone, androstenedione, AMH & Inhibin B (where indicated), and human chorionic gonadotropin stimulation were done as per protocol. RESULTS: In total, 48 patients were included in the study. Ambiguous genitalia (58.3%) followed by hypospadias (33.3%) were common presentation. Androgen biosynthetic defect were the most commonly encountered diagnosis followed by androgen insensitivity syndrome (AIS). Swyer syndrome was diagnosed in 4.2% of cases; partial gonadal dysgenesis, ovotesticular DSD, and vanishing testis syndrome contributed to 2% of cases each. Eight cases (16.7%) who presented with isolated proximal and midshaft hypospadias for whom no diagnosis was found were categorized in the "etiology unclear" group. AR gene mutation analysis designed against specific exons did not yield any results. CONCLUSION: 46 XY DSD is a heterogeneous group of patients with a varying age of presentation and a diverse clinical profile. Most patients are reared as males and maintained the same gender identity except in isolated cases. Diagnosis of AIS remains a clinical challenge as a definite hormonal criterion does not exist and genetic mutations in AR gene may be negative. Flanking region sequencing, whole genome sequencing, and promoter region sequencing may reveal pathogenic variants. Variations in other genes regulating AR pathway may also be candidates to be studied.

Novel mitochondria targeted copper(ii) complexes of ferrocenyl terpyridine and anticancer active 8-hydroxyquinolines showing remarkable cytotoxicity, DNA and protein binding affinity.

Metal complexes with organelle specificity and potent but selective cytotoxicity are highly desirable. In this work, we report the synthesis, characterization and cytotoxicity of six novel copper(ii) complexes of the formula [Cu(R-tpy)(N-O)]NO3 (1-6), where R-tpy is 4'-phenyl-2,2':6',2''-terpyridine (Ph-tpy; 1-3) or 4'-ferrocenyl-2,2':6',2''-terpyridine (Fc-tpy; 4-6), N-O is the anion of 8-hydroxyquinoline (HQ in 1, 4), 5-chloro-7-iodo-8-hydroxyquinoline (CQ in 2, 5) or 5-nitro-8-hydroxyquinoline (NQ in 3, 6). The complex [Cu(Fc-tpy)2](ClO4)2 (7) has also been prepared as a control and structurally characterized. The optimized geometries and the frontier orbitals of the complexes have been obtained from DFT calculations. The ferrocenyl appended complexes having the anticancer active CQ (in 5) and NQ (in 6) ligands show remarkable cytotoxicity, giving the respective IC50 values of 0.75 µM and 0.52 µM in HeLa and 1.3 µM and 2.6 µM in MCF-7 cancer cells. The phenyl appended complexes 2 and 3 are less active than their ferrocenyl analogues in both the cells while the complexes of HQ (in 1, 4) are the least active. Interestingly, complexes 4-6 are significantly less toxic to MCF-10A normal cells. The DCFDA, annexin-V-FITC and propidium iodide nuclear staining assays reveal an apoptotic mechanism of cell death which is attributable to the metal-assisted generation of reactive oxygen species. Imaging experiments on HeLa cells reveals that complex 5 accumulates primarily inside the mitochondria. The complexes bind to calf thymus DNA with moderate affinity giving Kb values in the range of 6.3 × 104-7.4 × 104 M-1 and to HSA protein with significant affinity giving KHSA values in the range of 8.6 × 104-1.3 × 105 M-1. Their affinity for DNA suggests that mitochondrial DNA could be the target while their affinity for HSA suggests that they could be transported by HSA in the blood. This work is the first report to show that the ferrocenyl appended copper(ii) complexes of hydroxyquinoline ligands are remarkably cytotoxic to cancer cells but significantly less toxic to normal cells.

Long-term hepatic arterial infusion of 5-fluorodeoxyuridine for liver metastases using an implantable infusion pump.

Twenty-one patients with liver metastases of various histologies (predominantly colorectal carcinoma) underwent Infusaid pump implantation for long-term hepatic arterial 5-fluorodeoxyuridine (5-FUdR) infusion. Patients received 5-FUdR infusion on a 2-wk cycle alternating with a 2-wk saline--heparin infusion. A dosage of 0.2-0.3 mg/kg/day (average 0.23 mg/kg/day) was infused for a cumulative 5-FUdR administration of 1940 days. Six patients (29%) responded to therapy (five colorectal, one carcinoid); median response duration was 6 mo. Median survival for the treated group was 17 mo from diagnosis of liver metastases and 13 mo from pump implantation. Median survival among the six responding patients was 15 mo from diagnosis of liver metastases and 11 mo from pump implantation. Comparison of survival from the diagnosis of liver metastases of the treated group to ten patients found ineligible for the study by virtue of extrahepatic metastases revealed no significant difference in median (18 mo for ineligible group) or overall survival. However, median survival for the treated group after pump implantation (13 mo) was significantly better than the median survival of the ineligible group after evaluation for this study (4 mo). Toxicities of therapy included fatigue, anorexia, nausea, vomiting, toxic hepatitis, epigastric pain, and diarrhea. No patients died of toxicity, but six patients required hospitalization for management of pain or vomiting. No serious technical complications developed in any patient except separation of the infusion catheter at its junction with the pump in one patient, necessitating pump replacement for continuation of therapy. These survival data suggest identification of new anticancer agents for hepatic arterial infusion.

Hemodynamic evaluation of arterial stenoses by computer simulation.

A new method to assess the hemodynamic severity of arterial stenoses was proposed and evaluated. It is based on a previously developed finite element computer simulation model for laminar-separated flow in arteries of axially varying cross-section; the present modification allows use of angiographic stenosis shapes acquired by automatic edge-detection algorithms. The method was validated by comparing its results with published experimental and theoretic results for ideal stenosis shapes. At moderate flowrates (Reynolds number = 500), poststenosis flow separation was predicted for moderately severe (75% area reduction) but not for mild (25%) stenoses. For high flowrates (Reynolds number = 900) in a severe stenosis (89%), stagnation and reversed flow were predicted and the experimental nondimensional pressure drop of 48.5 was correctly determined. Bernoulli's Equation, which neglects viscosity, predicted a drop of only 40. For a severe stenosis (89%), even at low Reynolds numbers (50), reversed flow agreeing with other theoretic solutions was predicted. Predictions are especially useful at low flow rates, where experiments are difficult to conduct. The height of the curve on the graph of nondimensional pressure gradient vs. Reynolds number reflects the hemodynamic severity of a particular stenosis; these curves were predicted for moderate and severe ideal stenoses and agree with experiments. A similar analysis is applied to an actual human coronary artery stenosis, and the results are demonstrated to have use in assessing interventions during angiography.

Intravenous methylmethacrylate after total hip replacement.

In eight patients, radiographs made after total hip replacement revealed methylmethacrylate in the soft tissues of the thigh. In one of them the configuration of the density was that of a vein. In the other seven patients similar but less extensive soft-tissue densities were seen postoperatively. One patient had postoperative hypotension which was thought to be due to a myocardial infarction. In another patient, with a prior history of congestive heart failure, congestive heart failure developed again after total hip replacement. The relationship of these complications to the radiographic observations was not clear.

Study of catheter designs and drug mixing processes using 2D steady numerical simulations.

The effectiveness of substance delivery through catheters is an important issue in interventional radiology, especially for infusion therapies where the pharmacokinetic advantage of local intra-arterial drug administration has been firmly established. In principle, the procedure is used to provide appropriate local concentrations while maintaining low systemic values so as to minimise the global effect and toxicity of the intervention. However, poor drug mixing may produce excessive local concentrations potentially damaging for the surrounding tissues and may lead to unsuccessful therapies. These phenomena have been observed in the infusion therapies of liver cancers through the hepatic artery and with brain tumour therapies through the carotid artery. Many aspects of the drug delivery methodology have been explored in order to determine the infusion conditions that would provide optimal mixing: the catheter tip design is considered one of the most important characteristics to be investigated for this purpose. Interestingly, it turns out that angiographic procedures could also benefit from this, because better mixing properties are associated with designs that provide potentially less harmful flow conditions such as jets, whipping and recoil of the catheter on the vascular wall. A 2D steady numerical model is proposed, to simulate the main physical processes occurring during catheter substance infusion: blood dynamics is taken into account with the Navier-Stokes equations and substance dispersion by the flowing blood with the advection-diffusion equation. The model is used to evaluate mixing properties of certain catheter designs in different flow conditions. In particular, two types of side hole catheter are compared in the context of water bath injection and in the context of vessel injection. The simulations suggest that the improved mixing reported with water bath experiments would not be maintained in the clinical context of arterial circulation.

Value of spiral CT in hemodynamically stable patients following blunt chest trauma.

INTRODUCTION: Features of spiral CT (SCT)-fast scanning, dynamic injection of contrast allowing optimal vessel opacification, and supplemental multiplanar imaging-promises to provide increased accuracy in the diagnosis of acute and non acute thoracic vascular disease. Recent work demonstrating the cost effective triage of hemodynamically stable patients after blunt chest trauma for angiography based on dynamic CT findings has prompted an investigation into the accuracy of SCT in this clinical setting. METHODS: A retrospective review of all patients seen in the emergency department over the period of one year for aortic, thoracic, or blunt chest trauma evaluation was performed (74 patients) and all SCT scans available were reviewed and data reformatted for optimal delineation of pathology using maximum intensity projection and multiplanar reformation. The accuracy and predictive positive and negative values of SCT were calculated with respect to angiography, surgical, and/or clinical follow up evaluation. RESULTS: Twenty three (31%) patients went directly to angiography owing to mediastinal widening on chest film and hemodynamic instability, of which four were positive and required emergent surgery. Seven hemodynamically stable patients (9%) had noncontrast SCT owing to mediastinal widening on chest film, all of which had angiography with none having great vessel trauma. Fourty four hemodynamically stable patients (60%) had contrast enhanced SCT (ceSCT), of which five (11%) were abnormal and underwent angiography, four of these were positive for aortic damage, one for a subclavian artery laceration. Of the remaining 39 patients who had normal ceSCT; five had angiography, all of which were normal. Of the remaining 34 patients that had normal ceSCT none had adverse outcome on clinical follow-up, minimum of 12 months. CONCLUSION: The predictive positive value for aortic trauma of ceSCT in blunt trauma is 80%, with a predictive negative value of 100%, indicating that it is feasible for SCT to be a first line exam in blunt chest trauma in the future.

Improving the patient evaluation process in a cardiovascular and interventional radiology department.

Brigham & Women's Hospital (BWH) has adopted total quality management (TQM) to increase productivity and efficiency and to improve the quality of patient care services. This article reports on a quality improvement project in the department of radiology designed to improve the process of pre-procedure workup of patients referred for cardiovascular and interventional radiology (CVIR) procedures. The project was initiated, led, and conducted by a physician.

Identification of potential vaccine candidates against Streptococcus pneumoniae by reverse vaccinology approach.

In the past few decades, genome-based approaches have contributed significantly to vaccine development. Our aim was to identify the most conserved and immunogenic antigens of Streptococcus pneumoniae, which can be potential vaccine candidates in the future. BLASTn was done to identify the most conserved antigens. PSORTb 3.0.2 was run to predict the subcellular localization of the proteins. B cell epitope prediction was done for the immunogenicity testing. Finally, BLASTp was done for verifying the extent of similarity to human proteome to exclude the possibility of autoimmunity. Proteins failing to comply with the set parameters were filtered at each step. Based on the above criteria, out of the initial 22 pneumococcal proteins selected for screening, pavB and pullulanase were the most promising candidate proteins.

MDCT of 220 consecutive patients with suspected acute pulmonary embolism: incidence of pulmonary embolism and of other acute or non-acute thoracic findings.

PURPOSE: This study was undertaken to evaluate the incidence of pulmonary embolism (PE) and other clinically relevant thoracic findings discovered on contrast-enhanced multidetector computed tomography (MDCT) examination in patients with a suspicion of acute PE. MATERIALS AND METHODS: We retrospectively reviewed 220 reports of 40-row MDCT exams in consecutive patients (101 men, 119 women; mean age 55 years+/-18) suspected for acute PE. Presenting symptoms and risk factors were recorded. Image quality and incidence of PE and other clinically relevant thoracic findings were evaluated. RESULTS: MDCT were diagnostic in 96.8% of patients. Nineteen patients (8.6%) were positive for PE. Signs and symptoms were present in 82.7% (182) and risk factors in 38.2% (84) of the population. Clinically relevant thoracic findings were detected in 45.9% (101) of the patients. Ten patients had PE and other thoracic findings. Half of the patients (110) had neither PE nor other clinically relevant thoracic findings. CONCLUSIONS: Chest MDCT, with an excellent overall image quality, provided an explanation for the clinical presentation in about 50% of emergency department patients studied and was useful in detecting PE and other thoracic diseases with symptoms mimicking PE. However, half of the exams were negative.

Technical determinants of success in catheter-directed thrombolysis for peripheral arterial occlusions.

Local intraarterial thrombolytic therapy restores blood flow to the ischemic limb by dissolving the occlusive thrombus and identifies culprit lesions for treatment by means of surgical and/or percutaneous procedures. The techniques used for administration of the thrombolytic agent, the drug used, and the criteria for termination of the therapy are all factors that can influence both technical success and speed of lysis. This article discusses these factors and their influence on thrombolytic success.

Quantification in peripheral angiography.

The purpose of this report is to review the wide variety of quantitative methods that either augment the angiogram or improve the evaluation of peripheral vascular disease when used in conjunction with the angiogram. The term "quantitative angiography" has many connotations in this area. On the one hand it may refer to any type of measurement of vessel diameter and luminal narrowing from angiographic images, or to an analysis of relative blood flow using videodensitometric methods. In the broader context it may mean any objective hemodynamic measurement that is obtained at the time of angiography, for example, pressure drop across a stenosis or blood flow studies using Doppler techniques. Lastly there are the indirect, noninvasive measurements that angiographers use, in conjunction with the patient history and clinical examination, to interpret the angiographic images. Doppler pressure measurements and plethysmography are two examples in wide clinical use. Magnetic resonance imaging (MRI) represents a noninvasive imaging modality that can concomitantly quantitate blood flow; however, its clinical utility in the evaluation of peripheral vascular disease is yet to be established.

Percutaneous recanalization of peripheral arterial occlusions.

The aim of this paper is to summarize the current status of percutaneous methods for recanalizing peripheral arterial occlusions. Emphasis is placed on the role of peripheral intraarterial thrombolysis (PIAT) in the treatment of acute lower limb ischemia. Results of three prospective, randomized trials comparing PIAT with surgical revascularization are analyzed in the context of the existing, largely retrospective literature. The technique and recommendations for the application of PIAT are reviewed. Percutaneous aspiration thromboembolectomy, a technique that may be used alone or in conjunction with PIAT, is described in detail. We conclude with a brief description of various percutaneous mechanical thrombectomy devices, which may potentially see application in peripheral arterial occlusions.