1
|
Dusthackeer A, Kumar A, Mohanvel SK, Mahizhaveni B, Shivakumar S, Raghavi S, Azhagendran S, Vetrivel S, Rao VG, Yadav R, Paluru V, Purthy AJ, Hussain T, Kashyap V, Devi KR, Krishnan AKI, Anand P, Das P, Bansal AK, Das M, Kaur H, Raghunath D, Mondal R, Thomas BE. Mycobacterium tuberculosis strain lineage in mixed tribal population across India and Andaman Nicobar Island. World J Microbiol Biotechnol 2021; 37:192. [PMID: 34637049 DOI: 10.1007/s11274-021-03164-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 10/04/2021] [Indexed: 10/20/2022]
Abstract
In India, the tribal population constitutes almost 8.6% of the nation's total population. Despite their large presence, there are only a few reports available on Mycobacterium tuberculosis (M. tb) strain prevalence in Indian tribal communities considering the mobile nature of this population and also the influence of the mainstream populations they coexist within many areas for their livelihood. This study attempts to provide critical information pertaining to the TB strain diversity, its public health implications, and distribution among the tribal population in eleven Indian states and Andaman & Nicobar (A&N) Island. The study employed a population-based molecular approach. Clinical isolates were received from 66 villages (10 states and Island) and these villages were selected by implying situation analysis. A total of 78 M. tb clinical isolates were received from 10 different states and A&N Island. Among these, 16 different strains were observed by spoligotyping technique. The major M. tb strains spoligotype belong to the Beijing, CAS1_DELHI, and EAI5 family of M. tb strains followed by EAI1_SOM, EAI6_BGD1, LAM3, LAM6, LAM9, T1, T2, U strains. Drug-susceptibility testing (DST) results showed almost 15.4% of clinical isolates found to be resistant to isoniazid (INH) or rifampicin (RMP) + INH. Predominant multidrug-resistant (MDR-TB) isolates seem to be Beijing strain. Beijing, CAS1_DELHI, EAI3_IND, and EAI5 were the principal strains infecting mixed tribal populations across India. Despite the small sample size, this study has demonstrated higher diversity among the TB strains with significant MDR-TB findings. Prevalence of Beijing MDR-TB strains in Central, Southern, Eastern India and A&N Island indicates the transmission of the TB strains.
Collapse
|
2
|
Yadala A, Mukerjhi A, Vijayaprabhu N, Thiravayam E, Shivakumar S, Azhivahgan K. 850P Acute lymphoblastic leukemia patients receiving prophylactic cranial irradiation by volumetric modulated ARC therapy with hippocampal sparing: Dosimetric analysis. Ann Oncol 2021. [DOI: 10.1016/j.annonc.2021.08.143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
|
3
|
Sait U, K V GL, Shivakumar S, Kumar T, Bhaumik R, Prajapati S, Bhalla K, Chakrapani A. A deep-learning based multimodal system for Covid-19 diagnosis using breathing sounds and chest X-ray images. Appl Soft Comput 2021; 109:107522. [PMID: 34054379 PMCID: PMC8149173 DOI: 10.1016/j.asoc.2021.107522] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 04/20/2021] [Accepted: 05/21/2021] [Indexed: 12/23/2022]
Abstract
Covid-19 has become a deadly pandemic claiming more than three million lives worldwide. SARS-CoV-2 causes distinct pathomorphological alterations in the respiratory system, thereby acting as a biomarker to aid its diagnosis. A multimodal framework (Ai-CovScan) for Covid-19 detection using breathing sounds, chest X-ray (CXR) images, and rapid antigen test (RAnT) is proposed. Transfer Learning approach using existing deep-learning Convolutional Neural Network (CNN) based on Inception-v3 is combined with Multi-Layered Perceptron (MLP) to develop the CovScanNet model for reducing false-negatives. This model reports a preliminary accuracy of 80% for the breathing sound analysis, and 99.66% Covid-19 detection accuracy for the curated CXR image dataset. Based on Ai-CovScan, a smartphone app is conceptualised as a mass-deployable screening tool, which could alter the course of this pandemic. This app’s deployment could minimise the number of people accessing the limited and expensive confirmatory tests, thereby reducing the burden on the severely stressed healthcare infrastructure.
Collapse
|
4
|
Mulder F, van Es N, Kraaijpoel N, Di Nisio M, Carrier M, Duggal A, Gaddh M, Garcia D, Grosso M, Kakkar A, Mercuri M, Middeldorp S, Royle G, Segers A, Shivakumar S, Verhamme P, Wang T, Weitz J, Zhang G, Büller H, Raskob G. Corrigendum to “Edoxaban for treatment of venous thromboembolism in patient groups with different types of cancer: Results from the Hokusai VTE Cancer study” [Thromb. Res. vol. 185, January 2020, pages 13–19]. Thromb Res 2020; 191:156-159. [DOI: 10.1016/j.thromres.2020.02.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
5
|
Shivakumar S, Mohammadi L, Mangoni A. ADVERSE EFFECTS OF ENDOTHELIN RECEPTOR ANTAGONIST AND PHOSPHODIESTERASE-5 INHIBITOR COMBINATION THERAPY IN PULMONARY ARTERIAL HYPERTENSION: A SYSTEMATIC REVIEW AND META-ANALYSIS. Chest 2020. [DOI: 10.1016/j.chest.2020.05.397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
|
6
|
Mulder FI, van Es N, Kraaijpoel N, Di Nisio M, Carrier M, Duggal A, Gaddh M, Garcia D, Grosso MA, Kakkar AK, Mercuri MF, Middeldorp S, Royle G, Segers A, Shivakumar S, Verhamme P, Wang T, Weitz JI, Zhang G, Büller HR, Raskob G. Edoxaban for treatment of venous thromboembolism in patient groups with different types of cancer: Results from the Hokusai VTE Cancer study. Thromb Res 2019; 185:13-19. [PMID: 31733403 DOI: 10.1016/j.thromres.2019.11.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 11/06/2019] [Accepted: 11/07/2019] [Indexed: 12/21/2022]
Abstract
BACKGROUND The safety and efficacy of edoxaban and dalteparin is unclear for several cancer groups. METHODS We evaluated the occurrence of the primary outcome in large cancer groups. The primary outcome was the composite of recurrent VTE or major bleeding over 12 months. RESULTS In patients with gastrointestinal cancer, the primary outcome occurred in 19.4% patients given edoxaban and in 15.0% given dalteparin (risk difference [RD], 4.4%; 95%-CI, -4.1% to 12.8%). The corresponding rates for edoxaban and dalteparin were 10.4% and 10.7% for lung cancer (RD, -0.3%; 95%-CI, -10.0% to 9.5%), 13.6% and 12.5% for urogenital cancer (RD, 1.1; 95%-CI, -10.1-12.4), 3.1% and 11.7% for breast cancer (RD, -8.6; 95%-CI, -19.3-2.2), 8.9% and 10.9% for hematological malignancies (RD, -2.0; 95%-CI, -13.1-9.1), and 10.4% and 17.4% for gynecological cancer (RD, -7.0; 95%-CI, -19.8-5.7). In the subgroup of gastrointestinal cancer, edoxaban was associated with a 3.5% lower absolute risk of recurrent VTE and a 7.9% higher risk of major bleeding. CONCLUSION Edoxaban has a similar risk-benefit ratio to dalteparin in most cancer groups. In those with gastrointestinal cancer, the lower risk of recurrent VTE and the advantages of oral therapy need to be balanced against the increased risk of major bleeding.
Collapse
|
7
|
Shivakumar S, Joseph M, Swan A, Chew D, Jones D, Hecker T, Sinhal A. Is the Improvement in Mitral Regurgitation Post TAVR an Acute Phenomenon? Heart Lung Circ 2019. [DOI: 10.1016/j.hlc.2019.06.286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
8
|
Carrier M, Blais N, Crowther M, Kavan P, Le Gal G, Moodley O, Shivakumar S, Tagalakis V, Wu C, Lee AYY. Treatment algorithm in cancer-associated thrombosis: Canadian expert consensus. ACTA ACUST UNITED AC 2018; 25:329-337. [PMID: 30464682 DOI: 10.3747/co.25.4266] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Management of anticoagulant therapy for the treatment of venous thromboembolism (vte) in cancer patients is complex because of an increased risk of recurrent vte and major bleeding complications in those patients relative to the general population. Subgroups of patients with cancer also show variation in their risk for recurrent vte and adverse bleeding events. Accordingly, a committee of 10 Canadian clinical experts developed the consensus risk- stratification treatment algorithm presented here to provide guidance on tailoring anticoagulant treatment choices for the acute and extended treatment of symptomatic and incidental vte, to prevent recurrent vte, and to minimize the bleeding risk in patients with cancer. During a 1-day live meeting, a systematic review of the literature was performed, and a draft treatment algorithm was developed. The treatment algorithm was refined through the use of a Web-based platform and a series of online teleconferences. Clinicians using this treatment algorithm should consider the bleeding risk, the type of cancer, and the potential for drug-drug interactions in addition to informed patient preference in determining the most appropriate treatment for patients with cancer-associated thrombosis. Anticoagulant therapy should be regularly reassessed as the patient's cancer status and management change over time.
Collapse
|
9
|
Frazer J, Couban S, Doucette S, Shivakumar S. Characteristics predicting outcomes of allogeneic stem-cell transplantation in relapsed acute myelogenous leukemia. ACTA ACUST UNITED AC 2017; 24:e123-e130. [PMID: 28490935 DOI: 10.3747/co.24.3485] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Allogeneic hematopoietic stem-cell transplantation (ahsct) is associated with significant morbidity and mortality, but it can cure carefully selected patients with acute myeloid leukemia (aml) in second remission (cr2). In a cohort of patients with aml who underwent ahsct in cr2, we determined the pre-transplant factors that predicted for overall survival (os), relapse, and non-relapse mortality. We also sought to validate the prognostic risk groups derived by Michelis and colleagues in this independent population. METHODS In a retrospective chart review, we obtained data for 55 consecutive patients who underwent ahsct for aml in cr2. Hazard ratios were used to describe the independent effects of pre-transplant variables on outcome, and Kaplan-Meier curves were used to assess outcomes in the three prognostic groups identified by Michelis and colleagues. RESULTS At 1, 3, and 5 years post-transplant, os was 60%, 45.5%, and 37.5% respectively. Statistically significant differences in os, relapse mortality, and non-relapse mortality were not identified between the prognostic risk groups identified by Michelis and colleagues. Women were less likely than men to relapse, and a modified European Society for Blood and Marrow Transplantation (mebmt) score of 3 or less was associated with a lower non-relapse mortality. CONCLUSIONS The 37.5% 5-year os in this cohort suggests that, compared with other options, ahsct offers patients with aml in cr2 a better chance of cure. Our study supports the use of the mebmt score to predict non-relapse mortality in this population.
Collapse
|
10
|
Patil AR, Nandikoor S, De Marco J, Bhat R, Shivakumar S, Mallrajapatna G. Disorders of the lymphatic system of the abdomen. Clin Radiol 2016; 71:941-952. [PMID: 27450410 DOI: 10.1016/j.crad.2016.06.116] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 06/22/2016] [Accepted: 06/27/2016] [Indexed: 12/31/2022]
Abstract
The lymphatic system of the abdomen comprises of the cisterna chyli, its major and minor lymphatic tributaries, and lymph nodes. Disorders of the lymphatic system of the abdomen are rarely encountered and consist of primary and secondary types. Abdominal lymphangiomas constitute the majority and have characteristic imaging features. Complicated lymphangiomas may pose a diagnostic dilemma. Generalised systemic lymphangiomatosis is a rare condition and affects major organs with a poor prognosis. Retroperitoneal lymphangiectasia in the appropriate setting might predict underlying infection, such as filariasis. Other acquired conditions include iatrogenic or treatment-induced chylocoele. Chylous ascites can be secondary to multiple causes and can be confirmed by biochemical testing and lymphangiogram in appropriate settings.
Collapse
|
11
|
Tejesh CA, Manjunath AC, Shivakumar S, Vinayak PS, Yatish B, Geetha CR. Sonographic detection of tracheal or esophageal intubation: A cadaver study. Saudi J Anaesth 2016; 10:314-6. [PMID: 27375387 PMCID: PMC4916816 DOI: 10.4103/1658-354x.174922] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Background: The correct position of the endotracheal tube is confirmed by various modalities, most of which are not entirely reliable. Ultrasound is now increasingly available to anesthesiologists in the operating theater and is an attractive alternative. To investigate the usefulness of sonography in identifying the correct tracheal tube position in human cadavers. Materials and Methods: Endotracheal tubes placed randomly into trachea or esophagus was identified with a linear ultrasound probe placed transversely just above the suprasternal notch by a single anesthesiologist. Results: Of the 100 intubations performed at random, 99 were correctly identified to give a sensitivity of 100% and a specificity of 97.9%. Conclusion: Sonography is a useful technique to identify correct position of the tracheal tube.
Collapse
|
12
|
Linkins LA, Warkentin TE, Pai M, Shivakumar S, Manji RA, Wells PS, Wu C, Nazi I, Crowther MA. Rivaroxaban for treatment of suspected or confirmed heparin-induced thrombocytopenia study. J Thromb Haemost 2016; 14:1206-10. [PMID: 27061271 DOI: 10.1111/jth.13330] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Indexed: 11/29/2022]
Abstract
UNLABELLED Essentials Heparin-induced thrombocytopenia (HIT) is a thrombogenic condition that is difficult to treat. We evaluated rivaroxaban as a treatment option in patients with suspected or confirmed HIT. One patient had recurrent thrombosis and 9/10 patients with thrombocytopenia had platelet recovery. Rivaroxaban may be an effective and safe treatment option for HIT. SUMMARY Background Rivaroxaban is a direct oral anti-Xa inhibitor that has the potential to greatly simplify treatment of heparin-induced thrombocytopenia (HIT). Objectives To evaluate the efficacy and safety of rivaroxaban in this patient population, we conducted a multicenter, single-arm, prospective cohort study of patients with suspected or confirmed HIT. Patients/Methods Twenty-two consecutive adults with suspected or confirmed HIT received rivaroxaban 15 mg bid until a local HIT assay result was available. Participants with a positive local assay result continued rivaroxaban 15 mg bid until platelet recovery (or until day 21 if they had acute thrombosis at study entry), then stepped down to rivaroxaban 20 mg daily until day 30. Results and Conclusions The primary outcome measure, incidence of new symptomatic, objectively-confirmed venous and arterial thromboembolism at 30 days, occurred in one HIT-positive participant (4.5%; 95% confidence interval [CI], 0-23.5%) and one HIT-positive participant required limb amputation despite platelet recovery. Platelet recovery was achieved in nine out of 10 HIT-positive patients with thrombocytopenia. Rivaroxaban appears to be effective for treating patients with confirmed HIT, although the small number of patients enrolled limits precision.
Collapse
|
13
|
Easaw JC, Shea-Budgell MA, Wu CMJ, Czaykowski PM, Kassis J, Kuehl B, Lim HJ, MacNeil M, Martinusen D, McFarlane PA, Meek E, Moodley O, Shivakumar S, Tagalakis V, Welch S, Kavan P. Canadian consensus recommendations on the management of venous thromboembolism in patients with cancer. Part 2: treatment. ACTA ACUST UNITED AC 2015; 22:144-55. [PMID: 25908913 DOI: 10.3747/co.22.2587] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Patients with cancer are at increased risk of venous thromboembolism (vte). Anticoagulation therapy is used to treat vte; however, patients with cancer have unique clinical circumstances that can often make decisions surrounding the administration of therapeutic anticoagulation complicated. No national Canadian guidelines on the management of established cancer-associated thrombosis have been published. We therefore aimed to develop a consensus-based, evidence-informed guideline on the topic. PubMed was searched for clinical trials and meta-analyses published between 2002 and 2013. Reference lists of key articles were hand-searched for additional publications. Content experts from across Canada were assembled to review the evidence and make recommendations. Low molecular weight heparin is the treatment of choice for cancer patients with established vte. Direct oral anticoagulants are not recommended for the treatment of vte at this time. Specific clinical scenarios, including the presence of an indwelling venous catheter, renal insufficiency, and thrombocytopenia, warrant modifications in the therapeutic administration of anticoagulation therapy. Patients with recurrent vte should receive extended (>3 months) anticoagulant therapy. Incidental vte should generally be treated in the same manner as symptomatic vte. There is no evidence to support the monitoring of anti-factor Xa levels in clinically stable cancer patients receiving prophylactic anticoagulation; however, levels of anti-factor Xa could be checked at baseline and periodically thereafter in patients with renal insufficiency. Follow-up and education about the signs and symptoms of vte are important components of ongoing patient care.
Collapse
|
14
|
Shivakumar S, Ilango K, Dubey G, Subhasree N, Agrawal A. Evaluation of plant based formulation on adolescent obesity and its associated bio-markers: A randomized, double blind, placebo controlled study. Complement Ther Med 2015; 23:157-64. [DOI: 10.1016/j.ctim.2015.01.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 01/23/2015] [Accepted: 01/28/2015] [Indexed: 11/29/2022] Open
|
15
|
Easaw J, Shea–Budgell M, Wu C, Czaykowski P, Kassis J, Kuehl B, Lim H, MacNeil M, Martinusen D, McFarlane P, Meek E, Moodley O, Shivakumar S, Tagalakis V, Welch S, Kavan P. Canadian consensus recommendations on the management of venous thromboembolism in patients with cancer. Part 1: prophylaxis. Curr Oncol 2015; 22:133-43. [PMID: 25908912 PMCID: PMC4399610 DOI: 10.3747/co.22.2586] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Patients with cancer are at increased risk of venous thromboembolism (vte). Anticoagulation therapy has been shown to prevent vte; however, unique clinical circumstances in patients with cancer can often complicate the decisions surrounding the administration of prophylactic anticoagulation. No national Canadian guidelines on the prevention of cancer-associated thrombosis have been published. We therefore aimed to develop a consensus-based, evidence-informed guideline on the topic. PubMed was searched for clinical trials and meta-analyses published between 2002 and 2013. Reference lists of key articles were hand-searched for additional publications. Content experts from across Canada were assembled to review the evidence and make recommendations. Low molecular weight heparin can be used prophylactically in cancer patients at high risk of developing vte. Direct oral anticoagulants are not recommended for vte prophylaxis at this time. Specific clinical scenarios, including renal insufficiency, thrombocytopenia, liver disease, and obesity can warrant modifications in the administration of prophylactic anticoagulant therapy. There is no evidence to support the monitoring of anti-factor Xa levels in clinically stable cancer patients receiving prophylactic anticoagulation; however, factor Xa levels could be checked at baseline and periodically in patients with renal insufficiency. The use of anticoagulation therapy to prolong survival in cancer patients without the presence of risk factors for vte is not recommended.
Collapse
|
16
|
Carrier M, Lazo-Langner A, Shivakumar S, Tagalakis V, Gross PL, Blais N, Butts CA, Crowther M. Clinical challenges in patients with cancer-associated thrombosis: Canadian expert consensus recommendations. ACTA ACUST UNITED AC 2015; 22:49-59. [PMID: 25684988 DOI: 10.3747/co.22.2392] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Venous thromboembolism is a common complication in cancer patients, and thromboembolism is the second most common cause of death after cancer progression. A number of clinical practice guidelines provide recommendations for the management of cancer-associated thrombosis. However, the guidelines lack recommendations covering commonly encountered clinical challenges (for example, thrombocytopenia, recurrent venous thromboembolism, etc.) for which little or no evidence exists. Accordingly, recommendations were developed to provide expert guidance to medical oncologists and other health care professionals caring for patients with cancer-associated thrombosis. The current expert consensus was developed by a team of 21 clinical experts. For each identified clinical challenge, the literature in medline, embase, and Evidence Based Medicine Reviews was systematically reviewed. The quality of the evidence was assessed, summarized, and graded. Consensus statements were generated, and the experts voted anonymously using a modified Delphi process on their level of agreement with the various statements. Statements were progressively revised through separate voting iterations and were then finalized. Clinicians using these recommendations and suggestions should tailor patient management according to the risks and benefits of the treatment options, patient values and preferences, and local cost and resource allocations.
Collapse
|
17
|
Shivakumar S. Leptospirosis: need for diagnostic criteria. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2014; 62:547. [PMID: 25856929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
|
18
|
Lakshmi Ranganatha V, Bushra Begum A, Prashanth T, Gurupadaswamy H, Madhu S, Shivakumar S, Khanum SA. Synthesis and larvicidal properties of benzophenone comprise indole analogues against Culex quinquefasciatus. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.dit.2013.10.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
19
|
Wahid A, Sridhar BK, Shivakumar S. Preparation and evaluation of transdermal drug delivery system of etoricoxib using modified chitosan. Indian J Pharm Sci 2011; 70:455-60. [PMID: 20046770 PMCID: PMC2792537 DOI: 10.4103/0250-474x.44593] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Revised: 03/19/2008] [Accepted: 07/24/2008] [Indexed: 11/24/2022] Open
Abstract
In the present investigation chitosan has been chemically modified by treating with two different aldehydes like acetaldehyde and propionaldehyde to form Schiff’s bases. Schiff’s bases of chitosan with acetaldehyde and propionaldehyde were named as polymer A and polymer B, respectively. Fourier Transform Infra Red (FTIR) spectral data have confirmed the reaction carried out on chitosan. Drug free polymeric films of chitosan, chemically modified chitosan and chitosan/hydroxypropylmethylcellulose blend were prepared and evaluated for various physicochemical characters. Further, the films were incorporated with anti-inflammatory drug, etoricoxib using glycerol as plasticizer. The drug loaded films were cross-linked with sodium citrate and studied for permeation characteristics across dialysis membrane and rat skin. All the films were evaluated for bursting strength, swelling index, moisture uptake, thickness uniformity, drug content uniformity, tensile strength, percent elongation at break, percent flatness, water vapour transmission rate and in vitro drug permeation study.
Collapse
|
20
|
Loganathan N, Shivakumar S. Epidemiological Risk Factors of Urban Leptospirosis in North Chennai (Tamil Nadu) - A South India Study. Int J Infect Dis 2008. [DOI: 10.1016/j.ijid.2008.05.1185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
21
|
Shivakumar S, Prabhakar BT, Jayashree K, Rajan MGR, Salimath BP. Evaluation of serum vascular endothelial growth factor (VEGF) and microvessel density (MVD) as prognostic indicators in carcinoma breast. J Cancer Res Clin Oncol 2008; 135:627-36. [DOI: 10.1007/s00432-008-0497-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2008] [Accepted: 09/23/2008] [Indexed: 12/21/2022]
|
22
|
Sumathi G, Narayanan R, Shivakumar S. Leptospirosis laboratory, Madras Medical College: review of our experience (2004-2006). Indian J Med Microbiol 2008; 26:206-7. [PMID: 18445975 DOI: 10.4103/0255-0857.40553] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
23
|
Hema R, Senthil-Kumar M, Shivakumar S, Chandrasekhara Reddy P, Udayakumar M. Chlamydomonas reinhardtii, a model system for functional validation of abiotic stress responsive genes. PLANTA 2007; 226:655-70. [PMID: 17431668 DOI: 10.1007/s00425-007-0514-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2006] [Accepted: 03/13/2007] [Indexed: 05/02/2023]
Abstract
Stress tolerance is a multigenic character and there are many stress responsive genes, which are stress specific. Although many of these have been cloned, their functional significance remains fragmentary. Hence it is important to identify the relevant stress genes involved in altering the metabolism for adaptation. Overexpression is one of the several approaches and Chlamydomonas is a suitable system to study the functional relevance of stress genes. Stress responses can only be assessed on prior exposure to sublethal induction stress. In this study the acclimation response of Chlamydomonas was assessed for different abiotic stresses using physiological screens like chlorophyll stability, membrane damage, cell viability, accumulation of free radicals, survival and recovery growth. We demonstrate that Chlamydomonas responds to diverse stresses and is a potential system to study the relevance of stress genes. The relevance of choline oxidase A (codA), a key enzyme in glycinebetaine biosynthesis, was examined by developing transformants expressing codA gene from Arthrobacter globiformis. Southern positive transformants showed enhanced accumulation of glycinebetaine. The transformants also showed enhanced growth under salinity, high light coupled with methylviologen-induced oxidative stress, high temperature and cold stress. However the transgenics were not tolerant to PEG-mediated simulated osmotic stress, LiCl, menadione and UV stress. Increased cell survival and decreased chlorophyll degradation in transformants under acclimated conditions further confirmed the relevance of codA in imparting stress tolerance. Our results indicated that the relevance of stress responsive genes can be efficiently validated for diverse abiotic stresses using Chlamydomonas system.
Collapse
|
24
|
Shivakumar S. Leptospirosis in Chennai--changing clinical profile. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2006; 54:964-5; author reply 965. [PMID: 17334021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
|
25
|
Shivakumar S, Vijayendra SVN. Production of exopolysaccharides by Agrobacterium sp. CFR-24 using coconut water - a byproduct of food industry. Lett Appl Microbiol 2006; 42:477-82. [PMID: 16620206 DOI: 10.1111/j.1472-765x.2006.01881.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIMS The work is intended to explore the suitability of underutilized coconut water (a byproduct of food industry) for the production of exopolysaccharides (EPS) by Agrobacterium sp. CFR 24. METHODS AND RESULTS Besides checking the suitability of coconut water for the production of water-soluble (WS) and water-insoluble (WIS) EPS, certain fermentation parameters, such as initial pH, incubation period and kinetics of EPS production were investigated. The coconut water medium was found to support the production of both types of EPS. The optimal initial pH and temperature was found to be 6.0 and 30 degrees C, respectively. In shake flask (150 rev min(-1)) studies, high-cell density inoculum resulted in the production of 11.50 g l(-1) of WIS-EPS and 4.01 g l(-1) WS-EPS after 72 and 96 h of fermentation, respectively. CONCLUSIONS Coconut water was found suitable for the production of microbial EPS by Agrobacterium sp. CFR 24 strain. Under optimum conditions, it produced a good amount of WIS-EPS, which is comparable with that of the sucrose medium (11 g l(-1)). SIGNIFICANCE AND IMPACT OF THE STUDY This is the first report on the use of coconut water as a fermentation medium for the production of any microbial EPS. Besides producing value-added products, use of this food industry byproduct, which is often being drained out, can significantly reduce the problem of environmental pollution.
Collapse
|