Artificial intelligence-enabled electrocardiographic algorithm for the detection of left ventricular dysfunction in emergency department patients undergoing high-sensitivity cardiac troponin T

Background

Artificial intelligence-augmented electrocardiogram (AI-ECG) algorithms have been developed from the standard 12-lead ECG and validated for the recognition of left ventricular systolic dysfunction (LVSD), defined as LV ejection fraction (LVEF)≤35%. Whether AI-ECG facilitates identification of LVSD and is associated with adverse outcomes in emergency department (ED) patients undergoing high-sensitivity cardiac troponin (hs-cTnT) testing is uncertain.

Purpose

To investigate the diagnostic and prognostic performance of AI-ECG in ED patients undergoing hs-cTnT measurement.

Methods

Observational US cohort study of ED patients undergoing hs-cTnT measurement. Cases with hs-cTnT increases >sex-specific 99th percentiles were adjudicated following the Fourth Universal Definition of Myocardial Infarction (MI). Post-discharge major adverse cardiac events (MACE) included death, MI, heart failure (HF) hospitalization, stroke or transient ischemic attack, and new onset atrial fibrillation/flutter during 2-years follow-up. The AI-ECG network output, which is a continuous number between 0–1, that provides a probability of LVSD, was obtained for each patient from the first ECG during the index presentation. An AI-ECG threshold of ≥0.256 indicates a positive screen that correlates with a high probability of LVSD.

Results

Among 1977 patients, 1729 (87%) had a negative AI-ECG screen, while 248 (13%) had a positive AI-ECG screen. Patients with a positive AI-ECG screen were older and had more comorbidities. As compared to patients with hs-cTnT≤99th percentile in whom AI-ECG was positive in 5.8%, those with hs-cTnT>99th percentile had a positive AI-ECG in 22% of cases (p<0.0001). Based on adjudicated diagnoses, the frequency of a positive AI-ECG was 20% in myocardial injury, 38% in type 1 MI, and 20% in type 2 MI. At 2-years follow-up, as compared to patients with a negative AI-ECG, those with a positive AI-ECG had a higher risk for MACE (48% vs. 21%, p<0.0001, adjusted HR 1.39, 95% CI 1.11–1.75) (Figure 1), mainly because of more deaths (43% vs. 30%, p=0.004) and HF hospitalizations (36% vs. 13%, p<0.0001). A positive AI-ECG was associated with a higher risk for MACE (60% vs. 41%, p<0.0001, adjusted HR 1.30, 95% CI 1.02–1.64) in those with hs-cTnT increases >99th percentile, but not in those without hs-cTnT increases. Among patients with an echocardiogram during index presentation or within 30-days (n=452), the diagnostic accuracy of AI-ECG for LVEF ≤35% was 81.4% (95% CI 77.5, 84.9) with a negative predictive value of 96.5% (95% CI 94.0, 98.2). A normal LVEF (>50%) was observed in 87% of those with a negative AI ECG, whereas in those with a positive AI-ECG LVEF was reduced (<50%) in 60%.

Conclusions

Among ED patients evaluated with hs-cTnT, a positive AI-ECG screen for LVSD identifies patients at high risk of MACE. These findings are largely because of more deaths and HF hospitalizations in those with hs-cTnT increases >sex-specific 99th percentiles.

Funding Acknowledgement

Type of funding sources: None.

The use of warfarin as part of antithrombotic strategy after transcutaneous aortic valve replacement is not associated with better medium-term outcomes

Background

Bioprosthetic valve thrombosis is currently a well-recognized cause of bioprosthetic valve dysfunction. It was found to be associated with accelerated degeneration of the bioprosthesis with higher rates of valve re-replacement, even after treatment with anticoagulation. We hypothesized that the use of warfarin for three months after transcatheter aortic valve replacement (TAVR) protects against accelerated valve degeneration and is therefore associated with better outcomes compared to dual antiplatelet therapy (DAPT).

Methods

Consecutive adult patients who underwent TAVR in our clinic between 2012 and 2019 were identified retrospectively. Patients with atrial fibrillation were excluded. Subsequently, patients who received DAPT were propensity matched to up to 2 patients who received three months of warfarin as part of their anti-thrombotic regimen. Matching was performed for variables that were significantly different at baseline between the two groups and included diabetes mellitus, prior myocardial infarctions, chronic lung disease, peripheral arterial disease, hemoglobin at time of TAVR, kidney function [creatinine>2], use of angiotensin-converting enzyme inhibitors / angiotensin II receptor blockers, beta blockers, the Society of Thoracic Surgeons (STS) score [STS ≥8, STS 4–8, STS<4], and valve size. The two groups were then compared for outcomes of ischemic stroke, death, valve re-replacement/intervention, the composite endpoint of the aforementioned three outcomes, as well as the three-month outcome of hemorrhagic strokes. Kaplan Meier was used for outcome analysis, and discharge date was considered time zero. Patients who had their anti-thrombotic therapy interrupted were censored at that time point.

Results

A total of 1,373 patients who underwent TAVR were identified. Of these, 576 patients with atrial fibrillation were excluded. Baseline characteristics were compared between 633 patients who received three months of warfarin and 164 patients who received DAPT after TAVR. After matching the two groups, 435 patients were included in the final analysis [warfarin in 281, DAPT in 154; median time to last follow up 2.61 years], Table 1. There was no difference in matched (Figure 1) or unmatched analysis (not shown) in outcomes of ischemic stroke, death, valve re-replacement/intervention, their composite endpoint, or hemorrhagic strokes (p>0.05 for all).

Conclusion

Antithrombotic regimen including three months of warfarin after TAVR was not associated with better outcomes of ischemic strokes, deaths, and valve re-replacement/intervention or with increased risk of hemorrhagic strokes compared to DAPT.

Funding Acknowledgement

Type of funding sources: None.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Autoimmune polyendocrine syndrome type 1 (APECED) in the Indian population: case report and review of a series of 45 patients

BACKGROUND

Autoimmune polyendocrinopathy-candidiasis-ectodermal-dystrophy (APECED) or autoimmune polyglandular syndrome type 1 (APS-1) is a rare autosomal recessive genetic disease due to mutations in the AIRE (AutoImmune REgulator) gene. The clinical diagnosis is classically based on the presence of at least two of the three main components: chronic mucocutaneous candidiasis, hypoparathyroidism and primary adrenal insufficiency. Patients often suffer from other endocrine or non-endocrine autoimmune conditions throughout life. APECED etiopathogenesis is mediated by T lymphocytes. Autoantibodies against proteins of the affected organs are found in the serum of APECED patients as well as neutralizing antibodies against cytokines. We report here the clinical and genetic characteristics of 45 Indian APECED patients in comparison to Finnish, Sardinian, Turkish and North/South American cohorts from their published results. We also report a new case of APECED of Indian origin, a 2-year old child suffering from chronic mucocutaneous candidiasis since the age of 8 months, with confirmatory AIRE homozygous mutation c.274C > T (p.R92W).

CONCLUSION

With the inherent limitations of a retrospective study, analysis of Indian APECED patients suggested that compared to classic criteria, application of Ferre/Lionakis criteria validated in North/South American patients could help in earlier diagnosis in 3 of 8 (37.5%) patients for whom adequate information for evaluation was available.

Efficacy and safety of peroral cholangioscopy with intraductal lithotripsy for difficult biliary stones: a systematic review and meta-analysis

BACKGROUND : Peroral cholangioscopy with intraductal lithotripsy facilitates optically guided stone fragmentation of difficult biliary stones refractory to conventional endoscopic therapy. The aim of this study was to evaluate the efficacy and safety of peroral cholangioscopy with intraductal lithotripsy for difficult biliary stones. METHODS : Searches of PubMed, EMBASE, Web of Science, and Cochrane databases were performed in accordance with PRISMA and MOOSE guidelines. Measured outcomes included overall fragmentation success, single-session fragmentation and duct clearance, and rate of adverse events. Sensitivity and subgroup analyses were performed based upon cholangioscopy technique and type of lithotripsy (laser versus electrohydraulic). Heterogeneity was assessed with I ² statistics. Publication bias was ascertained by funnel plot and Egger regression testing. RESULTS : 35 studies were included with 1762 participants (43.4 % men; mean age 61.5 [standard deviation (SD) 11.0]). Prior cholecystectomy had been performed in 37 % of patients, with a mean number of 1.6 (SD 0.5) ERCPs performed prior to lithotripsy. Mean stone size was 1.8 (SD 0.3) cm. Peroral cholangioscopy with intraductal lithotripsy achieved an overall stone fragmentation success of 91.2 % (95 %CI 88.1 % - 93.6 %; I ² = 63.2 %) with an average of 1.3 [SD 0.6] lithotripsy sessions performed. Complete single-session fragmentation success was 76.9 % (95 %CI 71.6 % - 81.4 %; I ² = 74.3 %). The adverse events rate was 8.9 % (95 %CI 6.5 % - 12.2 %; I ² = 60.6 %). Mean procedure time for peroral cholangioscopy was 67.1 (SD 21.4) minutes. There was no difference in overall fragmentation rate or adverse events; however, laser lithotripsy was associated with a higher single-session fragmentation rate and shorter procedure time compared with electrohydraulic lithotripsy. CONCLUSIONS : Peroral cholangioscopy with intraductal lithotripsy appears to be a relatively safe and effective modality for difficult biliary stones.

Endoscopic removal and replacement of the same lumen-apposing metal stent for multiple endoscopic necrosectomy sessions

BACKGROUND

This study evaluated the feasibility, efficacy, and safety of removal and replacement of a lumen-apposing metal stent (LAMS) to facilitate direct endoscopic necrosectomy (DEN).

METHODS

Endoscopic ultrasound-guided LAMS placement for walled-off necrosis (WON) was performed. During subsequent endoscopy, the LAMS was removed, DEN was performed, and the same LAMS was redeployed across the transmural tract.

RESULTS

140 LAMS were placed for drainage (43 pseudocysts, 97 WON) from 10/1/2016 to 11/15/2019, and 40 patients (mean age 43.9 [SD 15.4] years; 70 % males; mean WON size 10.9 [SD 4.9] × 8.7 [SD 3.8] cm) underwent removal and replacement of the same LAMS for multiple DEN sessions. LAMS was successfully replaced across the transmural tract during all 81 DEN sessions. Complete resolution was achieved after a median of 2 DEN sessions (range 1-7; mean 2.4 [SD 1.5]), with stent retrieval after a mean of 64.1 (SD 31.6) days after initial placement. No stent damage, tissue ingrowth, or major bleeding occurred.

CONCLUSIONS

Removal and replacement of LAMS during multiple necrosectomies is feasible, safe, and facilitates DEN.

Colorizing and Captioning Images Using Deep Learning Models and Deploying Them Via IoT Deployment Tools

Neural networks and IoT are some top fields of research in computer science nowadays. Inspired by this, this article works on using and creating an efficient neural networks model for colorizing images and transports them to remote systems through IoT deployment tools. This article develops two models, Alpha and Beta, for the colorization of the greyscale images. Efficient models are developed to lessen the loss rate to around 0.005. Further, it also develops an efficient model for the captioning of an image. The paper then describes the use of tools like AWS Greengrass and Docker for the deployment of different neural networks models, providing a comparative analysis among them, combining neural networks with IoT deployment tools.

Bouncing off the balloon: A new trick for selective cystic duct cannulation

Selective cannulation of the cystic duct for endoscopic transpapillary gallbladder drainage can be challenging in cases with a caudally branching cystic duct. Gulati and Rustagi describe a novel and simple technique in which a guidewire is bounced off a stone extraction balloon and redirected into the cystic duct.

Enteral fish oil supplementation in the resolution of parenteral nutrition associated cholestasis

OBJECTIVE

To analyze safety, tolerance and efficacy of enteral omega-3 fatty acids (FAs) in the resolution of Parenteral Nutrition Associated Cholestasis (PNAC) and postnatal growth among preterm neonates.

STUDY DESIGN

This is a single center retrospective case-control study of all neonates born less than 32 weeks of gestation and developed PNAC (Direct bilirubin >2 mg/dl). Infants who received enteral omega-3 FAs supplementation (1 g/Kg/d) served as cases and were compared with gestational age, gender and direct bilirubin level matched controls who did not receive enteral omega-3 FAs supplementation.

RESULTS

A total of 48 infants were analyzed, 24 who received enteral omega-3 fatty acids were matched with 24 controls. The omega-3 FAs and control groups were similar in gestational age (weeks) and birth weight (gram). Overall there were no differences between the two groups in infants' demographics or clinical characteristics including risk factors for the development of PNAC. Infants who received enteral omega-3 FAs had significantly fewer days of cholestasis (p = 0.025) and a higher average daily weight gain (grams/day) (p = 0.011) than their controls. In a linear regression analysis with days of cholestasis as the dependent variable and Ursodeoxycholic acid (UDCA) and Omega-3 FAs as independent variables, enteral omega-3 FAs remained associated with a shorter duration of cholestasis, p < 0.001.

CONCLUSION

Enteral fish oil is inexpensive, safe & well tolerated in preterm neonates with no contraindications to enteral feeding. Enteral omega-3 FAs are easy to administer and help in rapid resolution of PNAC while promoting postnatal weight gain in preterm infants.

Activity of enzalutamide in men with metastatic castration-resistant prostate cancer is affected by prior treatment with abiraterone and/or docetaxel

BACKGROUND

Enzalutamide and abiraterone are new androgen-axis disrupting treatments for metastatic castration resistant prostate cancer (mCRPC). We examined response and outcomes of enzalutamide-treated mCRPC patients in the real-world context of prior treatments of abiraterone and/or docetaxel.

METHODS

We conducted a seven-institution retrospective study of mCRPC patients treated with enzalutamide between January 2009 and February 2014. We compared baseline characteristics, PSA declines, PSA progression-free survival (PSA-PFS), duration on enzalutamide, and overall survival (OS) across subgroups defined by prior abiraterone and/or docetaxel.

RESULTS

Of 310 patients who received enzalutamide, 36 (12%) received neither prior abiraterone nor prior docetaxel, 79 (25%) received prior abiraterone, 30 (10%) received prior docetaxel, and 165 (53%) received both prior abiraterone and prior docetaxel. Within these groups, respectively, ≥30% PSA decline was achieved among 67%, 28%, 43%, and 24% of patients; PSA-PFS was 5.5 (95% CI 4.2–9.1), 4.0 (3.2–4.8), 4.1 (2.9–5.4), and 2.8 (2.5–3.2) months; median duration of enzalutamide was 9.1 (7.3-not reached), 4.7 (3.7–7.7), 5.4 (3.8–8.4), and 3.9 (3.0–4.6) months. Median OS was reached only for patients who received both prior abiraterone and docetaxel and was 12.2 months (95% CI 10.7–16.5). 12-month OS was 78% (59%–100%), 64% (45%–90%), 77% (61%–97%), and 51% (41%–62%). Of 70 patients who failed to achieve any PSA decline on prior abiraterone, 19 (27%) achieved ≥30% PSA decline with subsequent enzalutamide.

CONCLUSIONS

The activity of enzalutamide is blunted after abiraterone, after docetaxel, and still more after both, suggesting subsets of overlapping and distinct mechanisms of resistance.

IRF5rs2004640 single nucleotide polymorphism is associated with susceptibility to rheumatoid arthritis in South Indian Tamils

Polymorphism of interferon regulatory factor 5 (IRF5), a latent transcription factor gene has been associated with various auto-immune diseases. Our aim was to study the IRF5rs2004640 gene polymorphism and its association with disease susceptibility, disease phenotype and treatment response in South Indian Tamil patients with rheumatoid arthritis (RA).The study was conducted on 217 RA patients fulfilling the American College of Rheumatology (ACR) 2010 criteria and 482 healthy controls (HCs) without family history of autoimmune disease. The IRF5rs2004640 genotyping was performed using a TaqMan 5' allelic discrimination assay. We found that the IRF5rs2004640T allele [P < 0.0001, odds ratio (OR) 3.25, 95% confidence interval (CI) 2.55-4.12] and TT genotype (P < 0.0001, OR 4.60, 95% CI 3.23-6.57) were significantly more frequent in RA patients as compared with HCs. No association was found between IRF5rs2004640 polymorphism, clinical manifestations, autoantibody profile and treatment response. IRF5rs2004640 T (mutant) allele may be a susceptibility factor conferring risk for RA in South Indian Tamils, whereas G allele (wild type) may be protective.

Interleukin 17-producing γδT cells promote hepatic regeneration in mice

BACKGROUND & AIMS

Subsets of leukocytes synergize with regenerative growth factors to promote hepatic regeneration. γδT cells are early responders to inflammation-induced injury in a number of contexts. We investigated the role of γδT cells in hepatic regeneration using mice with disruptions in Tcrd (encodes the T-cell receptor δ chain) and Clec7a (encodes C-type lectin domain family 7 member a, also known as DECTIN1).

METHODS

We performed partial hepatectomies on wild-type C57BL/6, CD45.1, Tcrd(-/-), or Clec7a(-/-) mice. Cells were isolated from livers of patients and mice via mechanical and enzymatic digestion. γδT cells were purified by fluorescence-activated cell sorting.

RESULTS

In mice, partial hepatectomy up-regulated expression of CCL20 and ligands of Dectin-1, which was associated with recruitment and activation of γδT cells and their increased production of interleukin (IL)-17 family cytokines. Recruited γδT cells induced production of IL-6 by antigen-presenting cells and suppressed expression of interferon gamma by natural killer T cells, promoting hepatocyte proliferation. Absence of IL-17-producing γδT cells or deletion of Dectin-1 prevented development of regenerative phenotypes in subsets of innate immune cells. This slowed liver regeneration and was associated with reduced expression of regenerative growth factors and cell cycle regulators. Conversely, exogenous administration of IL-17 family cytokines or Dectin-1 ligands promoted regeneration. More broadly, we found that γδT cells are required for inflammatory responses mediated by IL-17 and Dectin-1.

CONCLUSIONS

γδT cells regulate hepatic regeneration by producing IL-22 and IL-17, which have direct mitogenic effects on hepatocytes and promote a regenerative phenotype in hepatic leukocytes, respectively. Dectin-1 ligation is required for γδT cells to promote hepatic regeneration.

Immunoglobulin-like transcripts 6 (ILT6) polymorphism influences the anti-Ro60/52 autoantibody status in south Indian SLE patients

Introduction

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disorder with complex etiology. Loss of immune tolerance against self-antigens results in activation of the immune system to produce autoantibodies, which in turn contribute to the clinical manifestations of the disease. Immune cells harbor a plethora of regulatory receptors. Immunoglobulin-like transcripts (ILTs) exhibit both immune activation and inhibitory properties. Genetic defects in genes encoding these receptors may predispose to development of autoimmune diseases secondary to loss of their function. The aim of our study was to analyze the presence or absence of the 6.7 kb segment in the ILT6 gene and its association with susceptibility to SLE and its different manifestations.

Method

A total of 188 SLE patients and 192 age-, sex similar-, ethnicity-matched controls were recruited. They were genotyped to test the presence or absence of the 6.7 kb segment of the ILT6 gene by polymerase chain reaction.

Results

The mutant allele lacking the 6.7 kb gene segment had an equal frequency in patients as well as controls (20% and 18%, respectively). The mutant allele was not associated with SLE or its clinical manifestations. However, the mutant allele was associated with the presence of anti-Ro60 ( p = 0.0005, OR 3.5, 95% CI 1.8–7.1) and anti-Ro52 ( p = 0.0027, OR 2.99, 95% CI 1.5–6.06) autoantibodies.

Conclusion

ILT6 deletion polymorphism does not appear to be a lupus susceptibility gene in South Indian Tamils, but may behave as a genetic modifier of autoantibody phenotype by influencing the production of anti-Ro60 and anti-Ro52 autoantibodies and thus indirectly contribute to autoimmune responses in SLE.

The CTLA4 +49 A/G (rs231775) polymorphism influences susceptibility to SLE in South Indian Tamils

Systemic lupus erythematosus (SLE) is a prototype autoimmune disease with complex etiology. Loss of immune tolerance and synthesis of autoantibodies against nuclear antigens contributes to the disease. Genetic aberrations disrupting the functions of immune regulatory receptors may facilitate the development of autoimmune diseases. Cytotoxic T-lymphocyte antigen 4 (CTLA4) is an inhibitory receptor for T cells and this study was carried out to analyze the influence of CTLA4 +49A/G (rs231775) polymorphism on susceptibility to SLE in ethnic Tamils. Three hundred SLE patients and 460 age and sex similar, ethnicity-matched controls were screened for the +49 A/G polymorphism by real time polymerase chain reaction (PCR). The wild allele (A) frequency in controls and cases was 63% and 47%, respectively. The presence of heterozygous (AG) and homozygous mutant (GG) genotype was associated with a significant risk to develop SLE (P = 0.0001, OR-2.29, 95% confidence interval (CI), 1.6-3.3) and (P = 0.0001, OR-4.3, 95% CI, 2.8-6.99). The frequency of mutant allele (G) in patients was also significantly associated with SLE (P = 0.0001, OR-1.9, 95% CI, 1.5-2.4). However, this polymorphism did not influence the clinical or serological phenotypes in our study. Therefore the CTLA4 +49 A/G polymorphism is a potential genetic risk factor for lupus susceptibility in South Indian Tamils, but does not appear to influence either the clinical or serological phenotype.

Abstract WMP46: Rotational Ischemic Vertebral Artery Compression (RIVAC) Syndrome Due to Cervical Facet Hypertrophy and Uncinate Process Osteophyte: Review of Seven Consecutive Cases

Introduction: The authors propose a new terminology, Rotational Ischemic Vertebral Artery Compression (RIVAC) syndrome, to describe patients who present with TIA or stroke from compression of the cervical vertebral artery (VA) below C2 by facet hypertrophy or uncinate process osteophyte associated with rotation of the head. The authors review clinical presentation, radiological findings, and management of 7 consecutive cases.

Methods: Prospective analysis of 7 consecutive cases of RIVAC syndrome was performed between 2004 and 2012. We reviewed peri-operative imaging, method of treatment, and clinical and angiographic outcome.

Results: A total of 6 patients (mean 66+/- 4 years) presented with stroke (N=2) or TIA including reproducible dizziness, vertigo, or syncope (N=4) associated with rotation of the head. Pre-operative dynamic cerebral angiogram showed near complete occlusion of cervical VA (N=2) or severe stenosis (60 to 80%) (N=5) during rotation of the head. The location of cervical VA compression was as follows: right C3-4 (N=1), left C4-5 (N=3), left C5-6 (N=2) and left C6-7 (N=1). Treatment included endovascular stent placement of VA without open surgery (N=1), endovascular stent placement of VA followed by partial left C5-6 factectomy 2 years later (N=1), posterior surgical decompression of VA along with bilateral facet screw fixation (N=4), and anterior cervical discectomy and fusion (N=1). Follow up dynamic cerebral angiograms and CTA angiogram of neck (6 months to 3 years) showed resolution of VA compression on rotation of head in all patients except for one who had lost in follow up. Clinical evaluation (range of 1 to 48 months) showed no recurrent stroke or TIA in all patients (mRS score of 0, N=6 and mRS of 3, N=1).

Conclusion: RIVAC syndrome should be recognized as an important cause of posterior circulation TIA or stroke associated with rotation of head. Pre-operative dynamic cerebral angiogram and CT angiogram of neck are essential in localization and characterization of the level and cause of VA compression. Open surgical decompression and fixation appears to be safe and effective treatment of patients with RIVAC syndrome.

Deriving benefit of early detection from biomarker-based prognostic models

Many prognostic models for cancer use biomarkers that have utility in early detection. For example, in prostate cancer, models predicting disease-specific survival use serum prostate-specific antigen levels. These models typically show that higher marker levels are associated with poorer prognosis. Consequently, they are often interpreted as indicating that detecting disease at a lower threshold of the biomarker is likely to generate a survival benefit. However, lowering the threshold of the biomarker is tantamount to early detection. For survival benefit to not be simply an artifact of starting the survival clock earlier, we must account for the lead time of early detection. It is not known whether the existing prognostic models imply a survival benefit under early detection once lead time has been accounted for. In this article, we investigate survival benefit implied by prognostic models where the predictor(s) of disease-specific survival are age and/or biomarker level at disease detection. We show that the benefit depends on the rate of biomarker change, the lead time, and the biomarker level at the original date of diagnosis as well as on the parameters of the prognostic model. Even if the prognostic model indicates that lowering the threshold of the biomarker is associated with longer disease-specific survival, this does not necessarily imply that early detection will confer an extension of life expectancy.

Polymorphism (C677T) in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene: A preliminary study on north Indian men

An elevated level of plasma homocysteine, sulfur containing amino acid generated through demethylation of methionine has been widely accepted as a risk factor for cardiovascular disease (CVD). The increase can result from genetic and/or nutrient related disturbances in the remethylation or transsulfuration pathways for homocysteine metabolism. A common mutation (C677T) in the gene encoding for the enzyme 5, 10-methylenetetrahydrofolate reductase (MTHFR) or deficiency of the B vitamins namely folic acid, B(12), B(6) can lead to hyperhomocysteinemia.In the present study, we have investigated the incidence of the (C677T) MTHFR polymorphism in the North Indian males. 141 angiographically proven coronary artery disease (CAD) patients and 55 age and sex matched healthy volunteers were examined for the association between MTHFR gene polymorphism and CAD. The MTHFR genotyping was performed using polymerase chain reaction (PCR) followed by restriction-isotyping with Hinf 1 endonuclease. A trend for higher 'T' allele frequency (0.19) was observed in patients than in controls (0.16). However no significant association was found between C677T mutation and CAD severity. The lack of statistical significance could be due to the small sample size studied. Hence a larger study including various ethnic groups is warranted.

Peak expiratory flow rate of children working in lock factories

Peak expiratory flow rate (PEFR) of 106 children working in different units of lock factory was measured and compared with age and sex matched control group of same socio-economic status children. All the children worked for about ten hours per day. It was observed that there was a significant decrease in PEFR of children working in the different units of lock factories i.e. Hand press, Polishing, Lock fitting, Lock packing units as compared to control group (P>0.001). The reduction percentage of PEFR was maximum in children working in polishing unit (25.48%).

Raised serum TNF-alpha, blood sugar and uric acid in preeclampsia in third trimester of pregnancy

In preeclampsia, insulin resistance occurs but the exact cause is unknown. It is uncertain whether women destined to develop preeclampsia have preexisting insulin resistance or it is acquired with the development of the disease. Fasting blood samples were collected from 10 normal control pregnant women and from 30 cases of preeclampsia in the third trimester of pregnancy to measure circulating level of glucose, uric acid and tumor necrosis factor-alpha (TNF) concentrations. Preeclampsia was diagnosed as per standard guideline adapted from national high blood pressure education program working group. In control group (n=10) mean age was 25+/-3.71 years, mean sugar level was 86.73+/-13.06 mg/dl, uric acid level was 3.25+/-+/-.59 mg/dl and TNF-alpha level was 9.93+/-9.56 pg/dl. In preeclampsia group mean age was 25.56+/-3.96 years, mean sugar level was 93.46+/-18.6 mg/dl, uric acid was 6.00+/-1.64 mg/dl and TNF-alpha level was 67.66+/-61.83 pg/dl. Statistical analysis done using Kruskal Wallis's test showed significantly raised levels of TNF-alpha (p<0.001), uric acid (p<0.001) and blood sugar (p=0.201) in preeclampsia cases. In preeclampsia there was positive significant correlations of raised TNF-alpha with uric acid (p<0.005). Spearman's test for correlation showed positive correlation of TNF-alpha with blood sugar (p<0.043) in cases of preeclampsia. The findings suggest the involvement of cytokines (TNF-alpha) in preeclampsia and may have a role in gestational diabetes mellitus and insulin resistance. In the present study, there was positive association of raised level of TNF-alpha with blood sugar / and uric acid levels.

Lipoprotein(a) as a marker of coronary artery disease and its association with dietary fat

OBJECTIVE

The main objectives of the study were to evaluate the effect of dietary fat on plasma lipoprotein(a) [Lp(a)] levels and to study the potential of Lp(a) as a more reliable marker for CAD compared to other lipids and lipoproteins.

METHODS

Twenty CAD patients and 20 healthy controls were recruited for the study. Their fasting plasma Lp(a) levels and complete lipid profile were assayed. The fat intake was calculated using 24 hours dietary recall method. The patients and controls were each divided into two subgroups: Group A consuming dietary fat > 30% and Group B consuming dietary fat < or = 30% of the total kilo-calories/day.

RESULTS

Results indicated that plasma Lp(a), total serum cholesterol (TC), tryglyceride (TG), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and LDL-C/HDL-C ratio of CAD patients were significantly higher than the controls. High fat intake was found to be associated with higher plasma Lp(a) levels (p<0.05) in patients only. No significant correlation was found between Lp(a) levels and other conventional lipoproteins.

CONCLUSION

The lack of correlation between Lp(a) and other lipoproteins indicates its potential as an independent risk factor for CAD. High fat intake led to higher plasma Lp(a) levels in patients; hence it would be worthwhile to evaluate the effect of quality and quantity of fat intake on plasma Lp(a) levels in a larger sample size.

Biocatalytic potential of Fusarium globulosum lipase in selective acetylation/deacetylation reactions and in ester synthesis

AIMS

The present study was carried out to assess the potential of Fusarium globulosum lipase (FGL) for chemoselective and regioselective biotransformations for the synthesis of industrially important organic compounds.

METHODS AND RESULTS

Different acetylation/deacetylation reactions and ester synthesis reactions were carried out in organic media. Fusarium globulosum lipase showed exclusive selectivity for the acetylation of the alcoholic hydroxyl group over the phenolic hydroxyl group of the hydroxymethylated phenols and aryl alkyl ketones. This also led to the enantiomeric resolution of the aryl alkyl ketone. In contrast, the lipase showed reversed selectivity in deacetylation where it preferred the phenolic acetoxy group over the alcoholic acetoxy moiety of the peracetates of hydroxymethylated compounds. The enzyme also exhibited strict regioselection for deacetylation at the para position of the peracetate of an aryl alkyl ketone. In addition, the lipase also synthesized a variety of industrially important fatty acid esters of sugars, sugar alcohols, alcohols and ascorbic acid with high preference for middle-chain fatty acids.

CONCLUSION

Fusarium globulosum lipase shows versatile catalytic potential in terms of chemo-, enantio- and regioselectivity and fatty acid specificity in carrying out a variety of industrially important biotransformations.

SIGNIFICANCE AND IMPACT OF THE STUDY

The biocatalytic potential of FGL can thus be utilized for the synthesis and modification of different types of polyphenolic compounds and esters. These compounds find widespread uses as surfactants, bioactive analogues, antioxidants and flavour components in the food, detergent, pharmaceutical and cosmetic industries.

Giant congenital nevomelanocytic nevus with satellite lesions, vitiligo and lipoma : a rare association

A case of giant congential nevomelanocytic nevus with satellite lesions, vitiligo and lipoma is described, owing to the rarity of the association. The constellation of finding can be explained on the basis of a defect in the neural crest, which is considered to be a common origin of melanoblasts, Schwann cells, sensory ganglia, bone, fat, muscle and blood vessels.

Early onset of endocrine abnormalities in beta-thalassemia major in a developing country

Endocrine complications in patients with thalassemia major in developing countries may be frequent due to suboptimal iron chelation. Data from developing countries are scant. We prospectively evaluated growth, growth hormone (GH), insulin-like growth factor I, thyroid hormone, cortisol and glucose tolerance in 84 patients over one year. Height standard deviation (SD) score of patients > 8 years (-2.2 +/- 1.5 against National Center for Health Statistics references) was significantly lower than that of normal controls (-1.0 +/- 0.7, p < 0.001). 51% of patients had GH deficiency, 13% hypocortisolism and 7.9% diabetes/impaired glucose tolerance. Ten of 11 adolescents/young adults had hypogonadism. Of 54 preadolescent children who underwent dynamic testing, 18 (33%) had at least one endocrine deficiency other than short stature. We conclude that hypogonadism and hypocortisolism form important causes for morbidity in our thalassemic children. Thalassemic patients in developing countries may be at risk for endocrine deficiencies at younger ages.

Comparative bioavailability of two formulations of azithromycin

AIM

To compare the bioequivalence of two brands of azithromycin capsules in healthy male volunteers for regulatory purpose.

METHOD

A single oral dose of 500 mg of either test (Panacea Biotec Ltd.) or reference (Pfizer India Ltd.) preparation of azithromycin was administered to 12 volunteers in double blind randomised cross over fashion. Serum levels of azithromycin were analysed using microbiological assay. The pharmacokinetic parameters studied were Cmax, Tmax, AUC, t1/2, Ke, CL and MRT. In vitro dissolution tests were conducted for both the preparations and compared with in vivo absorption.

RESULTS

The mean peak serum azithromycin concentration of 0.516 +/- 0.008 microgram/ml was observed at 2.33 +/- 0.22 h with test brand and was similar to that of reference brand with Cmax of 0.494 +/- 0.011 microgram/ml at 2.71 +/- 0.26 h. The statistical difference between all the other paharmacokinetic parameters were insignificant.

CONCLUSION

Both the brands of azithromycin can be considered to be bioequivalent on the basis of results obtained.

Get the right mix of bricks & clicks

The bright line that once distinguished the dot-com from the incumbent is rapidly fading. Success in the new economy will go to those who can execute clicks-and-mortar strategies that bridge the physical and virtual worlds. But how executives forge such strategies is under considerable debate. Despite the obvious benefits that integration offers--cross-promotion, shared information, purchasing leverage, distribution economies, and the like--many executives now assume that Internet businesses have to be separate to thrive. They believe that the very nature of traditional business--its protectiveness of current customers, its fear of cannibalization, its general myopia--will smother any Internet initiative. Authors Ranjay Gulati and Jason Garino contend that executives don't have to make an either- or choice when it comes to their clicks-and-mortar strategies. The question isn't, "Should we develop our Internet channel in-house or launch a spin-off?" but rather, "What degree of integration makes sense for our company?" To determine the best level of integration for their companies, executives should examine four business dimensions: brand, management, operations, and equity. Drawing on the experiences of three established retailers--Office Depot, KB Toys, and Rite Aid--the authors show the spectrum of strategies available and discuss the trade-offs involved in each choice. By thinking carefully about which aspects of a business to integrate and which to keep distinct, companies can tailor their clicks-and-mortar strategy to their own particular market and competitive situation, dramatically increasing their odds of e-business success.

Apolipoprotein(a) polymorphism and its association with plasma lipoprotein(a) levels: a north Indian study

Elevated levels of lipoprotein(a) has been regarded as an independent risk factor for coronary, peripheral and cerebral atherosclerosis. The enormous intra-personal variation in the plasma concentration of lipoprotein(a) is almost entirely controlled by the apolipoprotein(a) i.e. gene locus on the chromosome 6q 26-27. The apolipoprotein(a) molecule is highly polymorphic and is known to exist in multiple, genetically determined isoforms. These polymorphisms may be responsible for difference in promoter activity, variable size of apolipoprotein(a) and thereby variation in plasma lipoprotein(a) concentration. We studied the effect of two types of polymorphisms, (i) variation in length of the pentanucleotide repeat in the 5' flanking region starting -1373 bp upstream of AUG codon, and (ii) the Kringle-4 type 2 size polymorphism, on plasma lipoprotein(a) levels in North Indian population. The study group consisted of 88 angiographically assessed male coronary artery disease patients (age range 30-70 years) and 83 age- and sex-matched healthy controls. The pentanucleotide repeat polymorphism was analysed using polymerase chain reaction. In all, 8/11 pentanucleotide repeat isoforms were observed. Using SDS-agarose gel electrophoresis and immunoblotting isoforms having 12-50 Kringle-4 type 2 repeats were detected. Our study indicates a strong association of elevated plasma lipoprotein(a) concentration with coronary artery disease. An inverse correlation was seen between lipoprotein concentration and isoform size for both the pentanucleotide repeat polymorphism and the Kringle-4 type 2 polymorphisms; statistically significant difference (p = 0.001) was, however, observed only for the later.

Hepatocyte growth factor induces rat ovarian surface epithelial cell mitosis or apoptosis depending on the presence or absence of an extracellular matrix

The present studies showed that sequential treatment with equine CG (eCG) and hCG not only induced an increase in ovarian weight, but also caused an estimated 4.6-fold increase in the number of ovarian surface epithelial cells. In addition, eCG-hCG treatment increased ovarian hepatocyte growth factor (HGF) messenger RNA levels. These studies also demonstrated that rat primary ovarian surface epithelial cells as well as a cell line derived from rat ovarian surface epithelium (i.e. ROSE-179 cells) do not express the LH (hCG) receptor. Both of these cells express c-Met, the receptor for HGF. To assess the effects of hCG and HGF on ovarian surface epithelial cell mitosis, ROSE-179 cells were cultured for 24 h in serum-supplemented medium on either glass or the synthetic fibronectin-like extracellular matrix protein, pronectin (RGD). The cells were then cultured for 24 h in serum-free medium in the presence or absence of hCG or HGF. The numbers of cells at 2, 24, and 48 h of culture were determined. The percentage of apoptotic cells was assessed by in situ DNA staining at 48 h of culture. In the serum-supplemented medium in the presence or absence of RGD, the number of ROSE-179 cells doubled. In serum-free medium, cell proliferation was reduced, and the percentage of apoptotic nuclei ranged between 10-15% regardless of the substrate. Neither mitosis nor apoptosis was influenced by hCG in the presence or absence of RGD. For ROSE-179 cells cultured in serum-free medium on RGD, HGF induced mitosis, resulting in a 2.8 +/- 0.2-fold increase in cell number compared with the 24 h control values. On a glass substrate in serum-free medium, HGF did not induce mitosis, but increased the percentage of apoptotic nuclei. Time-lapse photographic analysis revealed that on RGD, cells undergoing HGF-induced mitosis showed a transient reduction in cell contact. On glass, HGF caused many cells to completely lose contact and separate from each other. Collectively, these data suggest that in vivo gonadotropins stimulate HGF expression and ovarian surface epithelial cell proliferation. Based on in vitro studies, it is likely that the mitogenic action of hCG is mediated by HGF. However, HGF only induces mitosis in the presence of an extracellular matrix.

Silicone gel sheet dressings for prevention of post-minigraft cobblestoning in vitiligo

Punch grafting was performed in 15 patients using punches varying in size from 2 to 3 mm in diameter. Silicone gel sheets were used as a post-operative dressing. Removal of the dressings after 7 days revealed no lifting of grafts in 13 patients. A minimally raised surface seen in two patients flattened after 6 to 8 weeks of continuous use of the dressing. At two months of follow-up, no cobblestoning or any other untoward effect was evident. Firm pressure provided by silicone gel sheets probably prevents cobblestoning by counteracting forces which tend to lift the grafts. Additionally, the sheets act as a brace preventing graft dislocation, provide a sterile atmosphere underneath the grafts, facilitate periodic observation due to their transparency, and are easily removed at the time of follow-up.

A role for hepatocyte growth factor/scatter factor in regulating normal and neoplastic cells of reproductive tissues

OBJECTIVE

To review data regarding the expression, function, and signal transduction pathways associated with hepatocyte growth factor/scatter factor (HGF/SF) as related to normal and neoplastic cells of reproductive tissues.

METHODS

Studies involving HGF/SF were reviewed and the data were summarized.

RESULTS

Hepatocyte growth factor/scatter factor is generally expressed within the stromal components of the testis, prostate, placenta, mammary gland, uterine endometrium, and ovary. The receptor for HGF/SF, c-met, is expressed in the epithelial cells of these tissues. Ligand activation of c-met results in its autotyrosine phosphorylation and the subsequent stimulation of numerous signal transduction pathways. Which pathways are activated determine in part the effect that HGF/SF has on a specific tissue. Hepatocyte growth factor/scatter factor can promote a variety of biologic responses including mitosis, motogenesis (i.e., cell movement), differentiation, and apoptosis. In addition, both HGF/SF and c-met continue to be expressed during the neoplastic transformation of cells from these reproductive tissues.

CONCLUSION

Hepatocyte growth factor/scatter factor plays an important role in regulating the physiologic function of several reproductive tissues and may also be involved in the oncogenesis of cells within these tissues.