Displaying publications 1 - 20 of 139 in total

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  1. Agarwal A, Vyas S, Kumar R
    Malays Fam Physician, 2015;10(3):35-7.
    PMID: 27570607
    Wellen's syndrome is a pre-infarction stage of coronary artery disease characterised by predefined clinical and electrocardiographic (ECG) criteria of a subgroup of patients with myocardial ischaemia. Early recognition and appropriate intervention of this syndrome carry significant diagnostic and prognostic value. We report this unusual syndrome in an elderly man who presented with recurrent angina and characteristic ECG changes as T-waves inversion in the precordial leads, especially in V2-V6 during pain-free periods and ECG obtained during episodes of pain demonstrating upright T-waves with possible elevated ST segments from V1-V4. Cardiac enzymes were positive and coronary angiography revealed critical stenosis in the proximal left anterior descending artery. It is important to timely identify this condition and intervene appropriately as these patients may develop extensive myocardial infarction that carries a significant morbidity and mortality.
  2. Anderson I, Kumar R, Patankar T, Tyagi A
    BMJ Case Rep, 2014;2014.
    PMID: 25257888 DOI: 10.1136/bcr-2014-205736
    We present the case of a 24-year-old man who presented with vertigo and right-sided weakness. Subsequent imaging demonstrated a lateral ventricle haemangioblastoma. This is the first case ever to be treated with surgical excision augmented by preoperative endovascular embolisation, as illustrated with perfusion CT scanning performed pre-embolisation and postembolisation. We present the case followed by a summary of the previously published cases and a discussion of the advantages of perfusion scanning and endovascular embolisation in these highly vascular (and therefore potentially dangerous) lesions.
  3. Segasothy M, Thyaparan A, Sivalingam S, Kamal A, Vijaya Kumar R
    Med. J. Malaysia, 1986 Mar;41(1):19-23.
    PMID: 3796342
    594 intravenous urograms done at the General Hospital, Ipoh, from January 1981 to March 1985 were reviewed for renal papillary necrosis (RPN). 11 cases (1.8%) of RPN were detected. Of these three were due to diabetes mellitus;eight were due to analgesic nephropathy. There was an equal incidence
    in males and females, contrary to the experience in the West and Australia. RPN was observed mainly in the older age groups. Five of the 11 cases of RPN presented as renal colic.
  4. Hashim R, How LS, Kumar RN, Sulaiman O
    Bioresour. Technol., 2005 Nov;96(16):1826-31.
    PMID: 16051090
    The flame retardancy of medium density fiberboard (MDF) made from mixture of rubberwood fibers and recycled old corrugated containers was studied. Aluminum trihydroxide (ATH) was used as a fire retardant additive and mixed with the fibers to manufacture experimental MDF panels using wet process. Phenol formaldehyde (PF) resin in liquid, 2% based on oven dry weight of fibers, was used along with 0%, 10%, 15% and 20% of ATH. The flame retardant test was done using the limiting oxygen index (LOI) test. The other properties investigated include internal bond strength, thickness swelling and water absorption. The results showed that ATH loading increased as the LOI of MDF increased. This demonstrated that ATH could improved the fire retardant property of MDF at sufficient loading. An increase in concentration of ATH showed an increase in the IB values of MDF made without resin. MDF panels made without resin showed a progressive increase in internal bond as the composition of recycled old corrugated containers fiber increased. Addition of resin improved internal bond strength and reduced thickness swelling, and water absorption. Thickness swelling of panel increased as the composition of recycled old corrugated containers fiber increased. Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX) showed that there is indication of ATH and resin filling the void space in between fibers.
  5. Wong YP, Tan GC, Kumar R
    Neuropathology, 2018 Dec;38(6):619-623.
    PMID: 30187570 DOI: 10.1111/neup.12511
    Xanthomatous changes can be observed in various conditions including primary xanthomatosis that is linked to an underlying hypercholesterolemia and more commonly associated with secondary xanthomatous degenerative processes in neoplasm and chronic inflammation. Meningioma with extensive xanthomatous change is exceedingly rare. The presence of cholesterol clefts within this peculiar meningioma subtype has not been described. Herein, we report an unusual case of xanthomatous meningioma in an 83-year-old normolipidemic woman, who presented to us with worsening lower limb weakness and global aphasia. There was increasing evidence to suggest that the presence of xanthomatous changes in long-standing meningioma is merely a sequela of cellular degeneration rather than true metaplastic change as previously hypothesized. Hence, the diagnosis of "xanthomatous meningioma" in the metaplastic category should be revisited and considered as a distinct histological subtype. The possible histogenesis of such intriguing phenomenon is discussed with a review of the literature.
  6. Kia Y, Osman H, Suresh Kumar R, Basiri A, Murugaiyah V
    Bioorg. Med. Chem. Lett., 2014 Apr 1;24(7):1815-9.
    PMID: 24594354 DOI: 10.1016/j.bmcl.2014.02.019
    Novel mono and bis spiropyrrolidine derivatives were synthesized via an efficient ionic liquid mediated, 1,3-dipolar cycloaddition methodology and evaluated in vitro for their AChE and BChE inhibitory activities in search for potent cholinesterase enzyme inhibitors. Most of the synthesized compounds displayed remarkable AChE inhibitory activities with IC50 values ranging from 1.68 to 21.85 μM, wherein compounds 8d and 8j were found to be most active inhibitors against AChE and BChE with IC50 values of 1.68 and 2.75 μM, respectively. Molecular modeling simulation on Torpedo californica AChE and human BChE receptors, showed good correlation between IC50 values and binding interaction template of the most active inhibitors docked into the active site of their relevant enzymes.
  7. Md Rezal RS, Hassali MA, Saleem F, Kumar R
    Value Health, 2015 Nov;18(7):A848-9.
    PMID: 26534536 DOI: 10.1016/j.jval.2015.09.420
    Conference abstrract
    Objectives: Antimicrobial resistance is associated with irrational use of antibiotics in general practice. We aimed to assess the frequency with which patients with Upper Respiratory Tract Infections were prescribed with antibiotics and the patterns of antibiotic prescription at primary healthcare centres in Malaysia.
    Methods: The study targeted all primary public healthcare centres in the district of Kota Setar, Kedah, Malaysia. A retrospective prescription analysis was conducted whereby prescriptions from 1st January 2014 to 31st March 2014 were screened and retrieved for antibiotics prescribed for upper respiratory infections. The data was entered into Microsoft Excel spread sheet, and exported to Statistical Package for Social Sciences, version 20 for further analysis. Frequencies and percentages were used to summarize the data. The Jonckheere–Terpstra test was used to evaluate the trend of antibiotic prescription. Where significant associations were reported, effect size was calculated by using Kendall tau correlation coefficient. P value of <0.05 was considered to be of statistical significance.
    Results: For the period of three months, 123,524 prescriptions were screened and analysed. 2270 (31.8%) prescriptions contained antibiotics prescribed for all URTIs visits. Among all antibiotics, macrolides were the most commonly prescribed antibiotic, constituting of 61% (n=1404) of total antibiotics prescribed for all cases. The Jonckheere–Terpstra test revealed a statistical relationship between prescribers and the diagnosis of the disease (p=0·001). Furthermore, a weak positive trend of association was reported with FMS being more accurate in diagnosis followed by MOs and AMOs (τ=0·122).
    Conclusions: Practicing physicians should adhere to the standard treatment practices, as antibiotic use in viral aetiology is ineffective, and encourages the persistence development of resistance. A comprehensive development of national antibiotic stewardship program is recommended to ensure organised and regulated control of antibiotic use in Malaysia.
  8. Tan BY, Shafie AA, Hassali MA, Saleem F, Kumar R
    Value Health, 2015 Nov;18(7):A831.
    PMID: 26534439 DOI: 10.1016/j.jval.2015.09.317
    Objectives: Medication adherence to treatment recommendations has major impact on health outcomes. Numerous interventions to improve medication adherence among the patients have been studied in clinical trials, including calendar packaging and patient reminder letters. Therefore, this study is aimed to explore hypertensive patient’s perceptions towards calendar packaging and its impact on medication adherence.
    Methods: A qualitative method was adopted, whereby two focus group sessions were conducted among 16 conveniently sampled hypertensive patients from a community based non-governmental organisation in the state of Penang, Malaysia. A pre validated focus group guide was constructed and used for data collection. Collected data was transcribed verbatim and analysed by thematic content analysis to identify the emerging themes.
    Results: Each focus group consisted of 8 hypertensive patients. Thematic content analysis resulted into 3 major themes (knowledge and familiarity with the medicines names and their packaging; perception about the packaging and labelling of medicines; knowledge and views of calendar packaging) and each theme was further divided into 2 sub themes. Majority of the hypertensive patients were not familiar with their medication names, however they were able to identify their medications based on the appearance and packaging. Participants agreed that calendar packaging is a great intervention to increase awareness among patients about regular medicine use and increase medication adherence.
    Conclusions: The study concluded that hypertensive patients relied on the packaging and labelling on the medications to identify their medications. Thus, packaging and labelling of the medications play an important role in improving medication adherence and reduce medication errors. This finding can help to enhance the drug manufacturers to pay attention on the drug packaging in order to increase medication adherence among the patients.
  9. Velmurugan C, Sundaram T, Sampath Kumar R, Vivek B, Sheshadrishekar D, Ashok Kumar BS
    Med. J. Malaysia, 2011 Mar;66(1):22-6.
    PMID: 23765138
    The hypoglycemic and hypolipidemic effect of Ethanolic extract of Ougeinia oojeinensis (200mg/kg) bark was evaluated with measurements including, Body weight, blood glucose level, urine glucose and biochemical parameters. The ethanolic extracts of the powdered bark was tested for its efficacy in alloxan-induced diabetic rats. Animals were induced for diabetes with Alloxan (150 mg/kg of body weight- i.p.) and treated orally with Ethanolic extract of Ougeinia oojeinensis. The extracts were also evaluated for acute oral toxicity studies and its effect on different biochemical parameters. The extracts showed significant (p<0.01) antihyperglycemic and hypolipidemic activity as compared to diabetic control. The extract shows beneficial effects on blood glucose and urine glucose level. It also reduces the elevated biochemical parameters such as triglycerides (TGL), low density lipoprotein (LDL), very low density lipoprotein (VLDL), Total Cholesterol (TC) and increased the reduced level of high density lipoprotein (HDL) and body weight, which might be due to presence of steroids, tannins, alkaloids and triterpenoids present in that extract. Thus ethanolic extract could serve as good oral hypoglycemic agents and seems to be promising for the development of phytomedicines for diabetes mellitus.
  10. Kumar R, Singh L, Zularisam AW, Hai FI
    Bioresour. Technol., 2016 Nov;220:537-542.
    PMID: 27614156 DOI: 10.1016/j.biortech.2016.09.003
    This study aims to investigate the potential of porous Co3O4 nanorods as the cathode catalyst for oxygen reduction reaction (ORR) in aqueous air cathode microbial fuel cells (MFCs). The porous Co3O4 nanorods were synthesized by a facile and cost-effective hydrothermal method. Three different concentrations (0.5mg/cm(2), 1mg/cm(2), and 2mg/cm(2)) of Co3O4 nanorods coated on graphite electrodes were used to test its performance in MFCs. The results showed that the addition of porous Co3O4 nanorods enhanced the electrocatalytic activity and ORR kinetics significantly and the overall resistance of the system was greatly reduced. Moreover, the MFC with a higher concentration of the catalyst achieved a maximum power density of 503±16mW/m(2), which was approximately five times higher than the bare graphite electrode. The improved catalytic activity of the cathodes could be due to the porous properties of Co3O4 nanorods that provided the higher number of active sites for oxygen.
  11. Kumar R, Singh L, Wahid ZA, Mahapatra DM, Liu H
    Bioresour. Technol., 2018 Apr;254:1-6.
    PMID: 29413909 DOI: 10.1016/j.biortech.2018.01.053
    The aim of this work was to evaluate the comparative performance of hybrid metal oxide nanorods i.e. MnCo2O4 nanorods (MCON) and single metal oxide nanorods i.e. Co3O4 nanorods (CON) as oxygen reduction catalyst in microbial fuel cells (MFC). Compared to the single metal oxide, the hybrid MCON exhibited a higher BET surface area and provided additional positively charged ions, i.e., Co2+/Co3+ and Mn3+/Mn4+ on its surfaces, which increased the electro-conductivity of the cathode and improved the oxygen reduction kinetics significantly, achieved an io of 6.01 A/m2 that was 12.4% higher than CON. Moreover, the porous architecture of MCON facilitated the diffusion of electrolyte, reactants and electrons during the oxygen reduction, suggested by lower diffusion (Rd), activation (Ract) and ohmic resistance (Rohm) values. This enhanced oxygen reduction by MCON boosted the power generation in MFC, achieving a maximum power density of 587 mW/m2 that was ∼29% higher than CON.
  12. Sharma V, Kaushik S, Kumar R, Yadav JP, Kaushik S
    Rev. Med. Virol., 2019 01;29(1):e2010.
    PMID: 30251294 DOI: 10.1002/rmv.2010
    Since emergence of the Nipah virus (NiV) in 1998 from Malaysia, the NiV virus has reappeared on different occasions causing severe infections in human population associated with high rate of mortality. NiV has been placed along with Hendra virus in genus Henipavirus of family Paramyxoviridae. Fruit bats (Genus Pteropus) are known to be natural host and reservoir of NiV. During the outbreaks from Malaysia and Singapore, the roles of pigs as intermediate host were confirmed. The infection transmitted from bats to pigs and subsequently from pigs to humans. Severe encephalitis was reported in NiV infection often associated with neurological disorders. First NiV outbreak in India occurred in Siliguri district of West Bengal in 2001, where direct transmission of the NiV virus from bats-to-human and human-to-human was reported in contrast to the role of pigs in the Malaysian NiV outbreak. Regular NiV outbreaks have been reported from Bangladesh since 2001 to 2015. The latest outbreak of NiV has been recorded in May, 2018 from Kerala, India which resulted in the death of 17 individuals. Due to lack of vaccines and effective antivirals, Nipah encephalitis poses a great threat to public health. Routine surveillance studies in the infected areas can be useful in detecting early signs of infection and help in containment of these outbreaks.
  13. Chattu VK, Kumar R, Kumary S, Kajal F, David JK
    J Family Med Prim Care, 2018 8 10;7(2):275-283.
    PMID: 30090764 DOI: 10.4103/jfmpc.jfmpc_137_18
    Nipah virus (NiV) encephalitis first reported in "Sungai Nipah" in Malaysia in 1999 has emerged as a global public health threat in the Southeast Asia region. From 1998 to 2018, more than 630 cases of NiV human infections were reported. NiV is transmitted by zoonotic (from bats to humans, or from bats to pigs, and then to humans) as well as human-to-human routes. Deforestation and urbanization of some areas have contributed to greater overlap between human and bat habitats resulting in NiV outbreaks. Common symptoms of NiV infection in humans are similar to that of influenza such as fever and muscle pain and in some cases, the inflammation of the brain occurs leading to encephalitis. The recent epidemic in May 2018 in Kerala for the first time has killed over 17 people in 7 days with high case fatality and highlighted the importance of One Health approach. The diagnosis is often not suspected at the time of presentation and creates challenges in outbreak detection, timely control measures, and outbreak response activities. Currently, there are no drugs or vaccines specific for NiV infection although this is a priority disease on the World Health Organization's agenda. Antivirals (Ribavirin, HR2-based fusion inhibitor), biologicals (convalescent plasma, monoclonal antibodies), immunomodulators, and intensive supportive care are the mainstay to treat severe respiratory and neurologic complications. There is a great need for strengthening animal health surveillance system, using a One Health approach, to detect new cases and provide early warning for veterinary and human public health authorities.
  14. Gujjar KR, van Wijk A, Kumar R, de Jongh A
    J Anxiety Disord, 2019 Mar;62:100-108.
    PMID: 30717830 DOI: 10.1016/j.janxdis.2018.12.001
    BACKGROUND: Although Virtual Reality Exposure Therapy (VRET) has proven to be effective in the treatment of various subtypes of specific phobia, there is limited evidence of its role in the treatment of dental phobia.

    METHOD: A single-blind RCT was conducted among 30 randomized patients with dental phobia to either VRET or informational pamphlet (IP) condition. Primary outcome anxiety measures (VAS-A, MDAS and DFS) were evaluated at baseline, pre- and post-intervention, 1-week, 3-months and 6-months follow-up. Secondary outcome measures assessed were pre-post behavioral avoidance, temporal variations of heart rate and VR-experience during and post-VRET, and dental treatment acceptance in both conditions at 6-month follow-up.

    RESULTS: Intention to treat analysis, using a repeated measures MANOVA, revealed a multivariate interaction effect between time and condition (p = 0.015) for all primary outcome measures (all ps 

  15. Shafiq N, Kumar R, Zahid M, Tufail RF
    Materials (Basel), 2019 Jul 17;12(14).
    PMID: 31319615 DOI: 10.3390/ma12142291
    This paper discussed the effects of modified metakaolin (MK) with nano-silica (NS) on the mechanical properties and durability of concrete. In the first phase, trial mixes of concrete were prepared for achieving the desired value of the 28 days compressive strength, and the charge passed in rapid chloride permeability test (RCPT). In the second phase, statistical analysis was performed on the experimental results using the response surface method (RSM). The RSM was applied for optimizing the mix proportions for the required performance by exploiting the relationship between the mix characteristics and the corresponding test results. A blend of 10% MK + 1% NS as part of cement replacement exhibited the highest mechanical properties and durability characteristics of concrete; concrete mix showed that the 28-days compressive strength (CS) was 103 MPa, which was 15% greater than the CS of the control mix without MK or NS. The same mix showed more than 40% higher flexural and split-tensile strength than the control mix; also it resulted in a reduction of 73% in the rapid chloride permeability value. ANOVA technique was used for optimizing the nano-silica and metakaolin content for achieving maximum compressive strength and minimum RCPT value. Statistical analysis using ANOVA technique showed that the maximum compressive strength and lowest RCPT value could be achieved with a blend of 10% MK and 1.55% NS.
  16. Gujjar KR, van Wijk A, Kumar R, de Jongh A
    J Evid Based Dent Pract, 2019 Jun;19(2):140-155.
    PMID: 31326046 DOI: 10.1016/j.jebdp.2019.01.009
    OBJECTIVES: The aim of this study was to evaluate the effectiveness of technology-based interventions for the treatment of dental anxiety in children and adults.

    DATA SOURCES: A systematic search using relevant keywords was conducted in PubMed-Medline, EMBASE, PsycINFO, CINAHL, Scopus, and The Cochrane Library.

    INCLUSION CRITERIA: Randomized controlled trials (RCTs) that compared technology-based interventions with inactive controls in the treatment of moderate to severe dental anxiety were included.

    RESULTS: A total of seven RCTs were included in the review. These studies investigated the effectiveness of video modeling, computerized cognitive behavioral therapy, virtual reality exposure therapy, and distraction with music and audiovisual video material. Six studies examining video modeling, computerized cognitive behavioral therapy, virtual reality exposure therapy, and distraction (audiovisual) showed significantly greater reductions in dental anxiety than inactive controls in both children and adults. None of the included studies followed Consolidated Standards of Reporting Trials guidelines completely or reported sufficient data, thereby precluding a possible meta-analysis. Four out of seven included studies were assessed to be at high risk of bias.

    CONCLUSIONS: A limited number of studies supported the effectiveness of technology-based interventions in the treatment of dental anxiety in children and adults.

    CLINICAL SIGNIFICANCE: The quality of the methods of studies on the effects of technology-based interventions allows only limited inferences on the effects of these interventions. However, within the limitations of the systematic review, the results converge to suggest that technology-based interventions may be useful as an adjunct to standard dental care. High-quality RCTs are needed to determine the (relative) effectiveness of these interventions.

    PROSPERO REGISTRATION NUMBER: CRD42017064810.

  17. Senthil Kumar R, Srinivasan R, Rawdzah MA, Malini P
    Genomics, 2019 Aug 23.
    PMID: 31450005 DOI: 10.1016/j.ygeno.2019.08.017
    Pieris rapae is a serious pest of brassicas worldwide. We performed de novo assembly of P. rapae transcriptome by next-generation sequencing and assembled approximately 65,727,422 clean paired-end reads into 32,118 unigenes, of which 13,585 were mapped to 255 pathways in the KEGG database. A total of 6173 novel transcripts were identified from reads directly mapped to P. rapae genome. Additionally, 1490 SSRs, 301,377 SNPs, and 29,284 InDels were identified as potential molecular markers to explore polymorphism within P. rapae populations. We screened and mapped 36 transcripts related to OBP, CSP, SNMP, PBAN, and OR. We analyzed the expression profiles of 7 selected genes involved in pheromone transport and degradation by quantitative real-time PCR; these genes are sex-specific and differentially expressed in the developmental stages. Overall, the comprehensive transcriptome resources described in this study could help understand and identify molecular targets particularly reproduction-related genes for developing effective P. rapae management tools.
  18. Ponnuchamy S, Kanchithalaivan S, Ranjith Kumar R, Ali MA, Choon TS
    Bioorg. Med. Chem. Lett., 2014 Feb 15;24(4):1089-93.
    PMID: 24472146 DOI: 10.1016/j.bmcl.2014.01.007
    A series of novel hybrid heterocycles comprising arylidene thiazolidine-2,4-dione and 1-cyclopropyl-2-(2-fluorophenyl)ethanone were synthesized. These compounds were evaluated for their antimycobacterial activity against Mycobacterium tuberculosis H37Rv in High Throughput Screen. Most of the hybrid arylidene thiazolidine-2,4-diones displayed moderate to good activity with MIC of less than 50 μM. Compound 1m exhibited maximum potency being 5.87 fold more active at EC50 and 6.26 fold more active at EC90 than the standard drug pyrimethamine.
  19. Suresh Kumar R, Almansour AI, Arumugam N, Altaf M, Menéndez JC, Kumar RR, et al.
    Molecules, 2016 Jan 29;21(2):165.
    PMID: 26840282 DOI: 10.3390/molecules21020165
    The microwave-assisted three-component reactions of 3,5-bis(E)-arylmethylidene]tetrahydro-4(1H)-pyridinones, acenaphthenequinone and cyclic α-amino acids in an ionic liquid, 1-butyl-3-methylimidazolium bromide, occurred through a domino sequence affording structurally intriguing diazaheptacyclic cage-like compounds in excellent yields.
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