Association between homocysteine and coronary artery disease-trend over time and across the regions: a systematic review and meta-analysis

BACKGROUND

The association of homocysteine with coronary artery disease (CAD) has been explored previously with mixed findings. The present Systematic Review and Meta-Analysis (SRMA) has assessed the pooled estimate of association between homocysteine (Hcy) and CAD, and its variation over the period and geography.

METHODS

Systematic literature search was done in PubMed, Scopus and Cochrane to identify the observational studies that have reported mean Hcy among cases (CAD) and control. The SRMA was registered in PROSPERO (ID-CRD42023387675).

RESULTS

Pooled standardized mean difference (SMD) of Hcy levels between the cases and controls was 0.73 (95% CI 0.55-0.91) from 59 studies. Heterogeneity was high (I2 94%). The highest SMD was found among the Asian studies (0.85 [95% CI 0.60-1.10]), while the European studies reported the lowest SMD between the cases and controls (0.32 [95% CI 0.18-0.46]). Meta-regression revealed that the strength of association was increasing over the years (Beta = 0.0227, p = 0.048).

CONCLUSIONS

Higher homocysteine levels might have a significant association with coronary artery diseases, but the certainty of evidence was rated low, owing to the observational nature of the studies, high heterogeneity, and publication bias. Within the population groups, Asian and African populations showed a greater strength of association than their European and American counterparts, and it also increased over the years.

ENVINet5 deep learning change detection framework for the estimation of agriculture variations during 2012-2023 with Landsat series data

Remote sensing is one of the most important methods for analysing the multitemporal changes over a certain period. As a cost-effective way, remote sensing allows the long-term analysis of agricultural land by collecting satellite imagery from different satellite missions. Landsat is one of the longest-running world missions which offers a moderate-resolution earth observation dataset. Land surface mapping and monitoring are generally performed by incorporating classification and change detection models. In this work, a deep learning-based change detection (DCD) algorithm has been proposed to detect long-term agricultural changes using the Landsat series datasets (i.e., Landsat-7, Landsat-8, and Landsat-9) during the period 2012 to 2023. The proposed algorithm extracts the features from satellite data according to their spectral and geographic characteristics and identifies seasonal variability. The DCD integrates the deep learning-based (Environment for visualizing images) ENVI Net-5 classification model and posterior probability-based post-classification comparison-based change detection model (PCD). The DCD is capable of providing seasonal variations accurately with distinct Landsat series dataset and promises to use higher resolution dataset with accurate results. The experimental result concludes that vegetation has decreased from 2012 to 2023, while build-up land has increased up to 88.22% (2012-2023) for Landsat-7 and Landsat-8 datasets. On the other side, degraded area includes water (3.20-0.05%) and fallow land (1-0.59%). This study allows the identification of crop growth, crop yield prediction, precision farming, and crop mapping.

An Unusual Case of Post-partum Native Tricuspid Valve Infective Endocarditis

Native valve infective endocarditis during pregnancy or the peripartum period is a rare entity with significant morbidity and mortality. Rheumatic heart disease was previously considered a significant risk factor, changing to intravenous drug abuse in recent decades. We hereby report a case of tricuspid native valve endocarditis complicating the peri-partum period in a young female without underlying traditional risk factors, who improved with medical therapy alone.

Automated myocardial infarction and angina detection using second derivative of photoplethysmography

Photoplethysmography (PPG) based healthcare devices have gained enormous interest in the detection of cardiac abnormalities. Limited research has been implemented for myocardial infarction (MI) detection. Moreover, PPG-based detection of angina is still a research gap. PPG signals are not always informative. Therefore, this research work presents the use of PPG signals and their second derivative to evaluate myocardial infarction and angina using a novel set of morphological features. The obtained morphological features are fed onto the feed-forward artificial neural network for the identification of the type of MI and unstable angina (UA). The initial experiments have been carried out on non-ambulatory (public) subjects for feature extraction and later evaluated on ambulatory (self-generated) databases. The intended method attains accuracy, sensitivity, and specificity of 98%, 97%, 98% on the public database and 94%, 94%, 94% on the self-generated database. The result shows that the proposed set of features can detect MI and UA with significant accuracy.

Major Aortopulmonary Collaterals From Coronary Arteries and Dual Left Anterior Descending Artery in an Adult With Tetralogy of Fallot

Major aortopulmonary collaterals (APCs) are more common with tetralogy of Fallot (TOF) with pulmonary atresia. Collateral arteries, when present, arise most commonly from the descending thoracic aorta, less commonly from the subclavian arteries, and rarely from the abdominal aorta or its branches or from the coronary arteries. Collaterals arising from the coronary arteries can cause myocardial ischemia due to coronary steal phenomenon. They can be addressed either by endovascular interventions like coiling or surgical ligation during the intracardiac repair. Coronary anomalies are seen in 5%-7% of TOF patients. In approximately 4% of TOF patients, the left anterior descending artery (LAD) or an accessory LAD takes origin from the right coronary artery or right coronary sinus and crosses the right ventricular outflow tract in its course toward the left ventricle. Presence of such anomalous coronary anatomy poses certain challenges during intracardiac repair of TOF.

Long-term hepatic and cardiac health in patients diagnosed with Sheehan's syndrome

PURPOSE

Sheehan's syndrome (SS) is characterised by chronic pituitary insufficiency following a vascular insult to the pituitary in the peripartum period. There is a lack of substantial evidence on the long-term hepatic and cardiac consequences in these patients, following hormone replacement.

METHODS

Patients with a diagnosis of SS were recruited for the study. Detailed clinico-biochemical and radiological evaluation were performed in all patients (n = 60). Hepatic and cardiac complications were assessed using fibroscan and echocardiography (2D speckle-tracking) respectively, in a subset of patients (n = 29) as well as age-and BMI-matched controls (n = 26). Controlled attenuation parameter (for steatosis) and liver stiffness measurement (for fibrosis) were used to define non-alcoholic fatty liver disease (NAFLD). Diastolic cardiac function was evaluated using standard criteria and systolic function by ejection fraction and global longitudinal strain (GLS).

RESULTS

The mean age of the cohort was 42.7 ± 11.6 years. Multiple (≥ 2) hormone deficiencies were present in 68.8% of patients, with hypothyroidism (91.4%), hypocortisolism (88.3%), and growth hormone (GH) deficiency (85.7%) being the most common. At a mean follow-up of 9.8 ± 6.8 years, NAFLD was present in 63% of patients, with 51% having severe steatosis, which was predicted by the presence of GH deficiency and higher body mass index. Though the ejection fraction was similar, increased left ventricular GLS (18.8 vs. 7.7%) was present in a significantly higher number of patients versus controls.

CONCLUSION

NAFLD, especially severe hepatic steatosis, is highly prevalent in SS. Subclinical cardiac systolic dysfunction (impaired GLS) is also more common, but of mild intensity.

Successful Endovascular Rescue Using the Brockenbrough Needle Following Inadvertent Stent-Graft Deployment in the False Lumen

Inadvertent deployment of stent grafts into the false lumen during thoracic endovascular aortic repair (TEVAR) is rare and is associated with catastrophic consequences. We present a case of accidental stent-graft deployment from the true lumen into the false lumen during TEVAR, resulting in hemodynamic collapse and visceral malperfusion. We successfully performed a bailout using the Brockenbrough needle to create new access from the true lumen to the false lumen and implanted another overlapping stent graft.

Correlation of mortality with Pro-BNP and precipitating factors of acute heart failure in patients presenting to a medical emergency of tertiary care hospital: an observational study from north India

OBJECTIVE

Acute heart failure is a syndrome defined as the new onset de novo heart failure or worsening [acutely decompensated heart failure (ADHF)] leading to symptoms and signs of HF, mostly related to systemic congestion as based on the European Society of Cardiology (ESC) definition. India has a huge burden of heart failure patients. Several factors have been identified as precipitating acute HF hospitalizations. These include myocardial ischemia, no adherence to medications, arrhythmias, infection, uncontrolled hypertension (HTN), anemia, renal impairment, and diet. However, there is a dearth of studies assessing their effect on mortality in patients admitted with acute heart failure. Many previous studies have shown that BNP and NT-pro-BNP are independent predictors of mortality and other cardiac outcomes in patients with heart failure (HF) and ADHF. However, no studies have provided any clear direction with respect to the critical cut-off values that suggest high mortality. Comprehensive knowledge of the correlation of Pro-BNP and precipitating factors of heart failure with mortality can help in prognostication and clinical management of AHF patients.

PATIENTS AND METHODS

This was a prospective observational cross-sectional study conducted in the Emergency Department of the Postgraduate Institute of Medical Education and Research, Chandigarh which is a teaching and research hospital located in North India. Patients were enrolled from 1st August 2021 to 28th February 2022. Patients who met inclusion criteria were enrolled; they were followed for 5 days. After 5 days outcomes were recorded. Various precipitating factors for hospitalization were identified and their clinical impact on mortality was noted. Pro-BNP values were obtained at admission and their correlation with mortality and patient outcome after 5 days was noted. Values of Pro-BNP were compared among those who survived after 5 days vs. those who had fatal outcomes.

RESULTS

The most common precipitating factor for AHF was poor medical compliance which did not affect mortality. It was followed by sepsis which significantly increases mortality in patients of AHF. ACS was also an important precipitating factor for AHF, though it had no effect on mortality. The mortality in the group of patients with very high Pro-BNP levels ≥ 2000 pg/ml was significantly higher than in the group of patients who had moderately elevated Pro-BNP < 2000 pg/ml. The median value of Pro-BNP was significantly higher in patients who had fatal outcomes [3670 (IQR- 2745 to 3980)] as compared to patients who survived after 5 days of hospitalization [1340 (IQR- 987 to 1670)].

CONCLUSIONS

Poor compliance with medications and sepsis are the most common precipitating factors for acute heart failure in north Indian patients. Sepsis as a precipitating factor is a significant risk factor for in-hospital mortality in acute heart failure patients presenting to the emergency department. Pro-BNP values above 2000 pg/ml in patients with acute heart failure requiring emergency admission are associated with a poor prognosis.

Clinical profile and 90 day outcomes of 10 851 heart failure patients across India: National Heart Failure Registry

AIMS

Limited data on the uptake of guideline-directed medical therapies (GDMTs) and the mortality of acute decompensated HF (ADHF) patients are available from India. The National Heart Failure Registry (NHFR) aimed to assess clinical presentation, practice patterns, and the mortality of ADHF patients in India.

METHODS AND RESULTS

The NHFR is a facility-based, multi-centre clinical registry of consecutive ADHF patients with prospective follow-up. Fifty three tertiary care hospitals in 21 states in India participated in the NHFR. All consecutive ADHF patients who satisfied the European Society of Cardiology criteria were enrolled in the registry. All-cause mortality at 90 days was the main outcome measure. In total, 10 851 consecutive patients were recruited (mean age: 59.9 years, 31% women). Ischaemic heart disease was the predominant aetiology for HF (72%), followed by dilated cardiomyopathy (18%). Isolated right HF was noted in 62 (0.6%) participants. In eligible HF patients, 47.5% received GDMT. The 90 day mortality was 14.2% (14.9% and 13.9% in women and men, respectively) with a re-admission rate of 8.4%. An inverse relationship between educational class based on years of education and 90 day mortality (high mortality in the lowest educational class) was observed in the study population. Patients with HF with reduced ejection fraction and HF with mildly reduced ejection fraction who did not receive GDMT experienced higher mortality (log-rank P < 0.001) than those who received GDMT. Baseline educational class, body mass index, New York Heart Association functional class, ejection fraction, dependent oedema, serum creatinine, QRS > 120 ms, atrial fibrillation, mitral regurgitation, haemoglobin levels, serum sodium, and GDMT independently predicted 90 day mortality.

CONCLUSION

One of seven ADHF patients in the NHFR died during the first 90 days of follow-up. One of two patients received GDMT. Adherence to GDMT improved survival in HF patients with reduced and mildly reduced ejection fractions. Our findings call for innovative quality improvement initiatives to improve the uptake of GDMT among HF patients in India.

Changing spectrum of infective endocarditis in India: An 11-year experience from an academic hospital in North India

Objective

Several studies have demonstrated a shift in the spectrum of infective endocarditis (IE) in the developed world. We aimed to investigate whether demographic and microbiologic characteristics of IE have changed in India.

Design

A retrospective analysis of patients with in north India between 2010 and 2020.

Methods

The clinical and laboratory profiles of 199 IE admitted to an academic hospital patients who met the modified Duke criteria for definite IE were analysed.

Results

The mean age was 34 years, and 84% were males. The main predisposing conditions were injection drug use (IDU) (n = 71, 35.7%), congenital heart disease (n = 46, 21.6%), rheumatic heart disease (n = 25, 12.5%), and prosthetic device (n = 19, 9.5%). 17.1% of patients developed IE without identified predispositions. Among 64.3% culture-positive cases, the most prevalent causative pathogens were Staphylococcus aureus (46.1%), viridans streptococci (7.0%), enterococci (6.0%), coagulase-negative staphylococci (5.5%), gram negative bacilli (5.5%), polymicrobial (5.5%), and Candida (1.0%). The tricuspid (30.3%), mitral (25.6%), and aortic (21.6%) valves were the most common sites of infection, and 60.3% had large vegetations (>10 mm). Systemic embolization occurred in 55.3% of patients at presentation. Cardiac surgery was required for 13.1%. In-hospital mortality was 17.1% and was associated with prosthetic devices (p-value, 0.001), baseline leucocytosis (p-value, 0.036) or acute kidney injury (p-value, 0.001), and a microbial etiology of gram negative bacilli or enterococci (p-value, 0.005).

Conclusion

IDU is now the most important predisposition for IE in India, and S. aureus has become the leading cause of native valve endocarditis with or without IDU.

Real-World Clinical Outcomes of Indigenous Biodegradable Polymer Drug-Eluting Stents

Introduction

The durable polymer has been shown to cause neoatherosclerosis, and chronic local inflammation, predisposing individuals to in-stent restenosis and stent thrombosis (ST). The biodegradable polymer stents, which degrade after the desired function of drug release is achieved, allow for endothelial healing. Indigenous coronary stent manufacturing and its use are on the rise nowadays, and their safety and efficacy have been studied in well-structured clinical trials. However, data are scarce on their safety and efficacy in the real-world clinical setting. In this study, we examine the real-world one-year performance of bioresorbable or polymer-free stents manufactured in India.

Materials and methods

This was a single-center, single-arm prospective observational study involving 210 patients undergoing intracoronary stenting using bioabsorbable or polymer-free drug-eluting stents (DES) from Indian manufacturers. All patients were followed up for 12 months prospectively for any major clinical events.

Results

The mean age of the enrolled patients was 57.04 years (IQR: 34-84 years), among which 159 (75.7%) were male; 99 (43.8%) patients had presented with acute myocardial infarction (MI). A total of 294 stents were deployed with a mean diameter of 3.1 ±0.4 mm, and a mean length of 29.4 ±9.1 mm. Two patients had experienced major adverse cardiovascular events (MACE). After three months of follow-up, one patient developed ST, and the same patient developed a cerebrovascular accident (CVA) after six months. After one year of follow-up, one patient died of cardiac causes.

Conclusion

Based on our findings, in the real-world clinical setting, the indigenously made biodegradable polymer DES are both safe and effective.

Submitral aneurysm of varied aetiologies: a case series

Background

Submitral aneurysm is a rare disease initially described in the African population. It is usually considered congenital in origin, due to a defect in the posterior portion of the mitral annulus. However, it can be seen in other diseases like ischaemic heart disease, rheumatic heart disease, infective endocarditis, tuberculosis, and syphilis.

Case presentation

Case 1 was a 29-year-old female, hypertensive undergoing maintenance haemodialysis for chronic kidney disease and on anti-tubercular therapy. She was found to have a large submitral aneurysm with severe mitral regurgitation, moderate left ventricular dysfunction, and pericardial effusion on echocardiogram. Case 2 was a 58-year-old gentleman presented with inferior wall ST-elevation myocardial infarction and was thrombolyzed with streptokinase for the same. Echocardiogram done 6 months later for evaluation of dyspnoea showed a large inferobasal aneurysm. Case 3 was a 56-year-old hypertensive presented with dyspnoea on exertion and echocardiogram showed a large posterolateral region with transmural late gadolinium enhancement. Case 4 was a 13-year-old boy presented with fever and cerebrovascular accident. Echocardiogram revealed vegetation in the mitral valve and a small submitral aneurysm with vegetation inside it.

Discussion

Submitral aneurysm is usually considered congenital in origin. However, it can be due to ischaemic heart disease, rheumatic heart disease, Takayasu arteritis, and tuberculosis. Top dimensional echocardiogram is the investigation of choice. Cardiac magentic resonance imaging helps in identifying the underlying aetiology and delineating the surrounding structures.

Real world perspective of coronary chronic total occlusion in third world countries: A tertiary care centre study from northern India

OBJECTIVES

The aim of this study is to determine the prevalence, clinical characteristics, angiographic profile and predictors of outcome for percutaneous coronary interventions (PCI) of coronary chronic total occlusions (CTO) in a tertiary referral centre of north India.

BACKGROUND

There is no data on the prevalence and very few reports on clinical characteristics, angiographic profile and outcome of PCI in CTO from India.

METHODS

Retrospective analysis was done for the data of 12,020 patients undergoing coronary angiography (CAG) between January 2018 to January 2019 at our centre. Detailed baseline clinical, angiographic and revascularization data was collected. Outcome of CTO PCI was also noted. All baseline parameters were analysed for predicting the outcome of CTO PCI.

RESULTS

CTO was identified in 16.3% (1968) patients undergoing CAG and in 24.4% of patients with hemodynamically significant CAD. CTO was predominantly found in LAD (48%) followed by RCA (42.9%) and LCx (25.3%) arterial distribution. Mean JCTO score was 1.93 ± 0.7. PCI as a management strategy was adopted in 456 of 1968 patients (23.1%) and was successful in 340 of 456 (74.6%) of patients. Almost all CTO PCI were attempted by an antegrade approach only. Increasing age, male sex, CTO in LCx arterial distribution and higher J CTO score were associated with poorer outcome in CTO PCI.

CONCLUSIONS

CTO's are commonly encountered during CAG procedures. In patients undergoing CTO PCI, a fair success rate can be achieved in a high volume experienced centre.

Awareness and adherence to primary and primordial preventive measures among family members of patients with myocardial infarction-the unmet need for a "Preventive Clinic"

Cardiovascular diseases remain the most common cause of sudden death and cause significant morbidity. We planned this study to assess awareness of cardiovascular risk factors among kin of myocardial infarction patients. We assessed 382 individuals for their knowledge of cardiovascular risk factors. Less than 50% of subjects identified cardiovascular risk factors correctly. Amongst the kins of patients 19.1%, 18.5%, 15.4% were newly diagnosed to have hypertension, impaired fasting blood glucose, diabetes in this study. This study reveals that most of the subjects were unaware of risk factors and were reluctant to adopt a healthy lifestyle. This is a lost opportunity for community-level preventive interventions. There is an unmet need for active health education, follow up with electronic support systems, and a team approach for a model preventive clinic.

Giant right atrial myxoma presenting as right heart failure: a rare manifestation

A 37-year-old man was presented in outpatient clinic of cardiology department with symptoms of easy fatigability and progressive increasing generalised anasarca since 5 months. Echocardiogram showed large mass of 9.8×7.8 cm in size in right atrium, attached to interatrial septum. Urgent opinion of thoracic surgeon was taken and surgical excision of mass under cardiopulmonary bypass was done. The tumour was large, fragile and histology confirmed it as myxoma. The patient made a good recovery and his symptoms resolved completely on follow-up.

Integrated 3D Anatomical Model for Automatic Myocardial Segmentation in Cardiac CT Imagery

Segmentation of epicardial and endocardial boundaries is a critical step in diagnosing cardiovascular function in heart patients. The manual tracing of organ contours in Computed Tomography Angiography (CTA) slices is subjective, time-consuming and impractical in clinical setting. We propose a novel multi-dimensional automatic edge detection algorithm based on shape priors and principal component analysis (PCA). We have developed a highly customized parametric model for implicit representations of segmenting curves (3D) for Left Ventricle (LV), Right Ventricle (RV), and Epicardium (Epi) used simultaneously to achieve myocardial segmentation. We have combined these representations in a region-based image modeling framework with high level constraints enabling the modeling of complex cardiac anatomical structures to automatically guide the segmentation of endo/epicardial boundaries. Test results on 30 short-axis CTA datasets show robust segmentation with error (mean ± std mm) of (1.46 ± 0.41), (2.06 ± 0.65), (2.88 ± 0.59) for LV, RV and Epi respectively.

Inhaled insulin: A "puff" than a "shot" before meals

Diabetes is a metabolic disorder characterized by relative or absolute deficiency of insulin, resulting in hyperglycemia. The main treatment of diabetes relies on subcutaneous insulin administration by injection or continuous infusion to control glucose levels, besides oral hypoglycemic agents for type 2 diabetes. Novel routes of insulin administration are an area of research in the diabetes field as insulin injection therapy is burdensome and painful for many patients. Inhalational insulin is a potential alternative to subcutaneous insulin in the management of diabetes. The large surface area, good vascularization, immense capacity for solute exchange and ultra-thinness of the alveolar epithelium facilitates systemic delivery of insulin via pulmonary administration. Inhaled insulin has been recently approved by Food and Drug Administration (FDA). It is a novel, rapid-acting inhaled insulin with a pharmacokinetic profile that is different from all other insulin products and comparatively safer than the previous failed inhaled insulin (Exubera).

Abstract OT2-6-12: A randomized pacebo-controlled phase II trial evaluating the effect of hedgehog inhibitor LDE225 on bone marrow disseminated tumor cells in women with early stage estrogen receptor negative and HER2 negative breast cancer

Background: 20% of invasive breast cancers are triple negative (TN). Chemotherapy improves the outcome for a subset of these patients. Recurrence rates of 40-50% have been reported in those patients who do not achieve a complete pathological response to neoadjuvant therapy. Currently, there are no targeted therapies to TN cancers. Data suggest that micrometastases or disseminated tumor cells (DTCs) that persist despite chemotherapy are enriched with cells that have stem cell-like features. The Hedgehog (Hh) signaling pathway, which is involved in modulating epithelial-mesenchymal transition and maintenance of breast cancer stem cells, is an attractive therapeutic target for patients with TN tumors. In preclinical models, we have shown that Hh inhibition reduced breast cancer growth and metastasis.

Trial Design: This is a placebo-controlled, double blinded, randomized phase II trial in early stage TN breast cancer patients with detectable DTCs in their bone marrow (BM) at the completion of all therapy. LDE225 is administered at 400 mg orally daily for a 28 day cycle for 20 cycles. After 6 cycles, BM will be collected for analysis.

Specific Aims: The primary endpoint is the elimination of DTCs after 6 cycles of LDE225. Additional endpoints include: 2-year disease-free survival (DFS) and overall survival (OS), effect on BM Ptch1 gene expression, toxicity profile of LDE225, DFS and OS in patients with no DTCs at screening versus DTC-positive patients in the placebo arm.

Eligibility: Patients with ER-/Her2- stage I-III invasive breast cancers who have completed all therapy and have detectable DTCs, as defined by a molecular based assay for DTCs performed in a CLIA-licensed facility are eligible.

Statistical Methods: Based on preliminary data, 60% of patients in the LDE225 arm are expected to be Ptch1 positive, and 50% of these patients are expected eliminate DTCs after 6 cycles of treatment. The expected clearance rate in the remaining 40% of the LDE225 arm is 5% with an overall clearance rate of 32%. In the placebo arm, the expected clearance rate is 5% regardless of Ptch1 status. A sample of 68 patients, 34 in each treatment arm, will have power ∼ 0.8 at a 0.05 significance level, after adjusting for one interim analysis, to detect a difference in DTC clearance rate of 32% in the LDE225 arm versus 5% in the placebo arm. Assuming that 40% of patients screened have detectable DTCs, approximately 170 patients will be screened to identify 68 with detectable DTCs.

Enrollment will be suspended for 3 months after the first 6 patients have been randomized to LDE225 therapy to allow time to document toxicity and adverse events. One interim analysis will be conducted after 50% of the patients have completed 6 months on study. The proportion of patients who are DTC-positive at 6 months will be estimated. The power of the study power to achieve its primary goal will be calculated conditional on results obtained to that point. The significance level of the final analysis will be adjusted to 0.048 in order to maintain an overall 0.05 significance level.

Accrual: Accrual is anticipated to begin August 2013. Target = 34 per arm. NCT01757327.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT2-6-12.

Cloning, characterization and expression of the chitinase gene of Enterobacter sp. NRG4

A chitinase producing bacterium Enterobacter sp. NRG4, previously isolated in our laboratory, has been reported to have a wide range of applications such as anti-fungal activity, generation of fungal protoplasts and production of chitobiose and N-acetyl D-glucosamine from swollen chitin. In this paper, the gene coding for Enterobacter chitinase has been cloned and expressed in Escherichia coli BL21(DE3). The structural portion of the chitinase gene comprised of 1686 bp. The deduced amino acid sequence of chitinase has high degree of homology (99.0%) with chitinase from Serratia marcescens. The recombinant chitinase was purified to near homogeneity using His-Tag affinity chromatography. The purified recombinant chitinase had a specific activity of 2041.6 U mg(-1). It exhibited similar properties pH and temperature optima of 5.5 and 45°C respectively as that of native chitinase. Using swollen chitin as a substrate, the K(m), k(cat) and catalytic efficiency (k(cat)/K(m)) values of recombinant chitinase were found to be 1.27 mg ml(-1), 0.69 s(-1) and 0.54 s(-1)M(-1) respectively. Like native chitinase, the recombinant chitinase produced medicinally important N-acetyl D-glucosamine and chitobiose from swollen chitin and also inhibited the growth of many fungi.

Microbial alkaline pectinases and their industrial applications: a review

The biotechnological potential of pectinolytic enzymes from microorganisms has drawn a great deal of attention from various researchers worldwide as likely biological catalysts in a variety of industrial processes. Alkaline pectinases are among the most important industrial enzymes and are of great significance in the current biotechnological arena with wide-ranging applications in textile processing, degumming of plant bast fibers, treatment of pectic wastewaters, paper making, and coffee and tea fermentations. The present review features the potential applications and uses of microbial alkaline pectinases, the nature of pectin, and the vast range of pectinolytic enzymes that function to mineralize pectic substances present in the environment. It also emphasizes the environmentally friendly applications of microbial alkaline pectinases thereby revealing their underestimated potential. The review intends to explore the potential of these enzymes and to encourage new alkaline pectinase-based industrial technology.