Telomere length in human adults and high level natural background radiation

PLoS One. 2009 Dec 23;4(12):e8440.
Das B, Saini D, Seshadri M.

Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai, India. birajalaxmi@yahoo.co.in

BACKGROUND: Telomere length is considered as a biomarker of aging, stress, cancer. It has been associated with many chronic diseases such as hypertension and diabetes. Although, telomere shortening due to ionizing radiation has been reported in vitro, no in vivo data is available on natural background radiation and its effect on telomere length. METHODOLOGY/PRINCIPAL FINDINGS: The present investigation is an attempt to determine the telomere length among human adults residing in high level natural radiation areas (HLNRA) and the adjacent normal level radiation areas (NLNRA) of Kerala coast in Southwest India. Genomic DNA was isolated from the peripheral blood mononuclear cells of 310 individuals (HLNRA: N = 233 and NLNRA: N = 77). Telomere length was determined using real time q-PCR. Both telomere (T) and single copy gene (S) specific primers were used to calculate the relative T/S and expressed as the relative telomere length. The telomere length was determined to be 1.22+/-0.15, 1.12+/-0.15, 1.08+/-0.08, 1.12+/-0.11, respectively, among the four dose groups (5.00 mGy per year), which did not show any dose response. The results suggested that the high level natural chronic radiation did not have significant effect on telomere length among young adult population living in HLNRA, which is indicative of better repair of telomeric ends. No significant difference in telomere length was observed between male and female individuals. In the present investigation, although the determination of telomere length was studied among the adults with an age group between 18 to 40 years (mean maternal age: 26.10+/-4.49), a negative correlation was observed with respect to age. However, inter-individual variation was (0.81-1.68) was clearly observed. CONCLUSIONS/SIGNIFICANCE: In this preliminary investigation, we conclude that elevated level of natural background radiation has no significant effect on telomere length among the adult population residing in HLNRAs of Kerala coast. To our knowledge, this is the first report from HLNRAs of the world where telomere length was determined on human adults. However, more samples from each background dose group and samples from older population need to be studied to derive firm conclusions.

PMCID: PMC2793520

A cross cultural review of the ethical issues in dementia care in Kerala, India and The Netherlands

Int J Geriatr Psychiatry. 2009 Apr;24(4):329-34.

Sowmini CV, De Vries R.

HRRC/ICMR, Department of Obstetrics and Gynaecology Medical College, Trivandrum, Kerala, India. sowminicv@gmail.com

BACKGROUND: The paper explores the diverse ethical issues in the care of persons with dementia, in the Netherlands and Kerala, India. These cross-cultural data are used to suggest newer ways for addressing the ethical issues in a mutually enhancing manner. METHODS: A thorough review of the literature focusing on ethical aspects of the care for persons with dementia. RESULTS: The medical paradigm is dominant in the Netherlands and awareness of dementia as an organic brain disease is low in Kerala. Institutionalized care is more common in the Netherlands and home-based care is the norm in Kerala. Institutional care is costly, whereas home-based care is stressful for caregivers. The advanced directive plays an influential role in the Netherlands, but this mechanism is yet to evolve in Kerala. The legal and social setting of the Netherlands has a strong influence on physician decision-making concerning end of life issues. In Kerala, discussion of these matters is nearly unknown. CONCLUSION: Limited awareness of dementia in Kerala should be addressed in public forums, which can then be used to garner governmental support. The predominantly institutional model of care-giving in the Netherlands and home-based care-giving in Kerala, each have their strengths; policy makers in both societies can usefully apply the values and merits inherent in both models. A culturally appropriate implementation of the advanced directive will have beneficial medical, social, and economic impacts in Kerala. The remarkable disparity between the Netherlands and Kerala in dealing with end-of-life issues will allow more philosophically and socially informed ways of addressing the ethical questions that arise in those situations. (c) 2008 John Wiley & Sons, Ltd.

PMID: 18814200 [PubMed - indexed for MEDLINE]

Quantum chemical DFT study of 4-azatricyclo [5.2.2.0(2,6)] undecane-3,5,8-trione

Spectrochim Acta A Mol Biomol Spectrosc. 2010 Feb 23. [Epub ahead of print]

Panicker CY, Varghese HT, Pillai KM, Mary YS, Raju K, Manojkumar TK, Bielenica A, Van Alsenoy C.

Department of Physics, TKM College of Arts and Science, Kollam, Kerala 691005, India.

Fourier-transform-Raman and infrared spectrum of 4-azatricyclo [5.2.2.0(2,6)] undecane-3,5,8-trione were recorded and analyzed. The vibrational wavenumbers were examined theoretically using the Gaussian03 set of quantum chemistry codes, and the normal modes were assigned by potential energy distribution (PED) calculations. The first hyperpolarizability, predicted infrared intensities and Raman activities are reported. The calculated first hyperpolarizability is comparable with reported values of similar structures which makes this compound an attractive object for future studies of nonlinear optics. Optimized geometrical parameters of the compound are in agreement with similar reported structures. The red shift of the NH stretching wavenumber in the infrared spectrum from the computational wavenumber indicates the weakening of NH bond. Copyright © 2010 Elsevier B.V. All rights reserved.

PMID: 20226726 [PubMed - as supplied by publisher]

Rickettsial infections Indian perspective

Indian Pediatr. 2010 Feb 7;47(2):157-64.

Rathi N, Rathi A.

Correspondence to Dr Narendra Rathi, Rathi Childrens Hospital and Maternity Home, Civil Lines, Akola 444 001, MS, India. drnbrathi@hotmail.com.

Context: Underdiagnosed and misdiagnosed rickettsial infections are important public health problems. They also lead to extensive investigations in children with fever of undetermined origin contributing to financial burden on families. The present review addresses the epidemiology, clinical features, diagnosis and management issues of these infections, primarily for a practicing clinician. Evidence acquisition: We did a PubMed, Medline and Cochrane library search for literature available in last 40 years. Results: Rickettsial infections are re-emerging and are prevalent throughout the world. In India, they are reported from Maharashtra, Tamil nadu, Karnataka, Kerala, Jammu and Kashmir, Uttaranchal, Himachal Pradesh, Rajasthan, Assam and West Bengal. In view of low index of suspicion, nonspecific signs and symptoms, and absence of widely available sensitive and specific diagnosic test, these infections are notoriously difficult to diagnose. Failure of timely diagnosis leads to significant morbidity and mortality. With timely diagnosis, treatment is easy, affordable and often successful with dramatic response to antimicrobials. As antimicrobials effective for rickettsial disease are usually not included in empirical therapy of nonspecific febrile illnesses, treatment of rickettsial disease is not provided unless they are suspected. Knowledge of geographical distribution, evidence of exposure to vector, clinical features like fever, rash, eschar, headache and myalgia alongwith high index of suspicion are crucial factors for early diagnosis.

PMID: 20228429 [PubMed - in process]

Coronary artery dilatation in Incomplete Kawasaki disease

Indian Pediatr. 2009 Jul;46(7):607-9.

Vijayan AP, Dinesh KB, Nath KR.

Department of Pediatrics, Malabar Institute of Medical Sciences, Calicut 673 016, Kerala, India. drvijayan.ap@gmail.com

We conducted this study to compare the incidence of coronary artery dilatation in children with Incomplete and Classical Kawasaki disease, diagnosed as per AHA criteria. Subjects were included on a retrospective review of records (2002-2007); those with a discharge diagnosis of Kawasaki disease were enrolled. A total of 29 patients were identified (3.1 per 1000 pediatric admissions), out of which 22 were boys (median age: 4.8 years; range: 4 months-11 years). Seventeen (58.6%) had Classical KD and twelve (41.4%) children had Incomplete KD. All children received IVIG and underwent echocardiography. Coronary involvement was more in Incomplete KD (11/12 = 91.6%) as compared to Classical KD (7/17= 41.1%). The sensitivity, specificity and predictive value of AHA criteria to detect coronary artery dilatation was 39%, 9%, and 41%, respectively. We conclude that children presenting with Incomplete Kawasaki disease are at a higher risk of coronary artery abnormalities.

PMID: 19638661 [PubMed - indexed for MEDLINE]

Physico-chemical studies of River Pumba and distribution of prawn, Macrobrachium rosenbergii

J Environ Biol. 2009 Sep;30(5):709-12.

John E.

Department of Zoology, Kongunadu Arts and Science College, Bharathiar University, Coimbatore-641 029, India. elizabethmoji@gmail.com

Physico-chemical factors of river Pumba, Kerala has been analyzed to understand its relationship with the distribution of Giant river prawn, Macrobrachium rosenbergii in the water body. Water samples were taken from two sites on the basis of presence and absence of juveniles. Analysis of temperature, pH, turbidity, dissolved oxygen, dissolved carbon dioxide and salinity of the water samples revealed that except salinity all the other parameters were identical in both the regions. Salinity was high i.e., 5-8 per thousand in lower Kuttanad region, where juveniles were seen. In upper Kuttanad region, where only adults were located, the salinity was of freshwater pattern i.e., 2.1-2.9 per thousand. The gut content analysis of M. rosenbergii in both the regions showed similar food pattern. The study reveals the significance of a water body with high saline region for breeding purpose and low saline region i.e., freshwater pattern for adult prawns in the life cycle of M. rosenbergii.

PMID: 20136053 [PubMed - indexed for MEDLINE]

Population dynamics of the rubber plantation litter beetle Luprops tristis, in relation to annual cycle of foliage phenology of its host, the para rubber tree, Hevea brasiliensis

J Insect Sci. 2009;9:1-10.

Sabu TK, Vinod KV.

Litter Entomology Research Unit, Post Graduate and Research Department of Zoology, St Joseph's College, Devagiri, Calicut, Kerala, India. sabukthomas@gmail.com

The population dynamics of the rubber plantation litter beetle, Luprops tristis Fabricius 1801 (Coleoptera: Tenebrionidae) was assessed in relation to the phenology of leaf shedding and defoliation pattern of para rubber trees, Hevea brasiliensis Müll. Arg (Malpighiales: Euphorbiaceae), during a two year study period. The abundance of adults, larvae and pupae per 1m(2) of litter sample was recorded. Post dormancy beetles appeared in leaf litter following annual leaf shedding, whereas larvae, pupae and teneral adults were present after leaf flush. No stages were recorded from plantations following the summer rains until the annual litter fall in the next season. Parental adults peaked at the time of leaf sprouting and tender leaf fall. Larvae and teneral adults peaked at the time of premature fall of green leaves and flowers. Teneral adults of six age classes were recorded and all entered dormancy irrespective of the feeding time available to each age class. Females outnumbered males in the parent generation, while the sex ratio of new generation adults was not biased towards either sex. The phenological stages of rubber trees included leaf fall in late December and early January, leaf sprouting and new leaf production in January and flowering in February. All feeding stages of L. tristis peaked in abundance when premature leaves are most abundant in the leaf litter. Prediction of the timing of appearance of various developmental stages of L. tristis in plantations, invasion into buildings and intensity of population build up in rubber belts is possible by tracking the phenology of leaf fall in rubber plantations, time of return of post dormancy adults and the onset of summer rainfall. Perfect synchrony was recorded between the field return of parental adults with annual leaf shedding, the oviposition phase of parental adults with tender leaf fall at the time of leaf sprouting, and larval and teneral adult stages with premature fall of leaves. Premature leaf availability is suggested as contributing to the reproductive efficiency of parental adults, the survival of early developmental stages and of new generation adults during dormancy.

PMID: 20050775 [PubMed - indexed for MEDLINE]

Molecular dynamics simulation studies and in vitro site directed mutagenesis of avian beta-defensin Apl_AvBD2

BMC Bioinformatics. 2010 Jan 18;11 Suppl 1:S7.

Soman SS, Sivakumar KC, Sreekumar E.

Molecular Virology Laboratory, Department of Molecular Microbiology, Rajiv Gandhi Centre for Biotechnology, Thycaud PO, Thiruvananthapuram-695014, Kerala, India. soja.saghar@gmail.com

BACKGROUND: Defensins comprise a group of antimicrobial peptides, widely recognized as important elements of the innate immune system in both animals and plants. Cationicity, rather than the secondary structure, is believed to be the major factor defining the antimicrobial activity of defensins. To test this hypothesis and to improve the activity of the newly identified avian beta-defensin Apl_AvBD2 by enhancing the cationicity, we performed in silico site directed mutagenesis, keeping the predicted secondary structure intact. Molecular dynamics (MD) simulation studies were done to predict the activity. Mutant proteins were made by in vitro site directed mutagenesis and recombinant protein expression, and tested for antimicrobial activity to confirm the results obtained in MD simulation analysis. RESULTS: MD simulation revealed subtle, but critical, structural variations between the wild type Apl_AvBD2 and the more cationic in silico mutants, which were not detected in the initial structural prediction by homology modelling. The C-terminal cationic 'claw' region, important in antimicrobial activity, which was intact in the wild type, showed changes in shape and orientation in all the mutant peptides. Mutant peptides also showed increased solvent accessible surface area and more number of hydrogen bonds with the surrounding water molecules. In functional studies, the Escherichia coli expressed, purified recombinant mutant proteins showed total loss of antimicrobial activity compared to the wild type protein. CONCLUSION: The study revealed that cationicity alone is not the determining factor in the microbicidal activity of antimicrobial peptides. Factors affecting the molecular dynamics such as hydrophobicity, electrostatic interactions and the potential for oligomerization may also play fundamental roles. It points to the usefulness of MD simulation studies in successful engineering of antimicrobial peptides for improved activity and other desirable functions.

PMID: 20122244 [PubMed - in process]

Thioredoxin-1 Gene Therapy Enhances Angiogenic Signaling and Reduces Ventricular Remodeling in Infarcted Myocardium of Diabetic Rats

Circulation. 2010 Mar 1. [Epub ahead of print]

Samuel SM, Thirunavukkarasu M, Penumathsa SV, Koneru S, Zhan L, Maulik G, Sudhakaran PR, Maulik N.

Molecular Cardiology and Angiogenesis Laboratory, Department of Surgery, UCONN Health Center, Farmington, Conn; Department of Biochemistry, University of Kerala, Trivandrum, Kerala, India; and Department of Cancer Biology, Dana Farber Cancer Institute, Harvard Medical School, Boston, Mass.

BACKGROUND: -The present study evaluated the reversal of diabetes-mediated impairment of angiogenesis in a myocardial infarction model of type 1 diabetic rats by intramyocardial administration of an adenoviral vector encoding thioredoxin-1 (Ad.Trx1). Various studies have linked diabetes-mediated impairment of angiogenesis to dysfunctional antioxidant systems in which thioredoxin-1 plays a central role. Methods and Results-Ad.Trx1 was administered intramyocardially in nondiabetic and diabetic rats immediately after myocardial infarction. Ad.LacZ was similarly administered to the respective control groups. The hearts were excised for molecular and immunohistochemical analysis at predetermined time points. Myocardial function was measured by echocardiography 30 days after the intervention. The Ad.Trx1-administered group exhibited reduced fibrosis, oxidative stress, and cardiomyocyte and endothelial cell apoptosis compared with the diabetic myocardial infarction group, along with increased capillary and arteriolar density. Western blot and immunohistochemical analysis demonstrated myocardial overexpression of thioredoxin-1, heme oxygenase-1, vascular endothelial growth factor, and p38 mitogen-activated protein kinase-beta, as well as decreased phosphorylated JNK and p38 mitogen-activated protein kinase-alpha, in the Ad.Trx1-treated diabetic group. Conversely, we observed a significant reduction in the expression of vascular endothelial growth factor in nondiabetic and diabetic animals treated with tin protoporphyrin (SnPP, a heme oxygenase-1 enzyme inhibitor), even after Ad.Trx1 therapy. Echocardiographic analysis after 4 weeks of myocardial infarction revealed significant improvement in myocardial functional parameters such as ejection fraction, fractional shortening, and E/A ratio in the Ad.Trx1-administered group compared with the diabetic myocardial infarction group. Conclusions-This study demonstrates for the first time that impairment of angiogenesis and myocardial dysfunction can be regulated by Ad.Trx1 gene therapy in streptozotocin-induced diabetic rats subjected to infarction.

PMID: 20194885 [PubMed - as supplied by publisher]

Polycrystalline coating of hydroxyapatite on TiAl6V4 implant material grown at lower substrate temperatures by hydrothermal annealing after pulsed laser deposition

Proc Inst Mech Eng H. 2009 Nov;223(8):1049-57.

Saju KK, Reshmi R, Jayadas NH, James J, Jayaraj MK.

Department of Mechanical Engineering, Cochin University of Science and Technology, Kalamassery, Kochi, Kerala 682025, India. kksaju@cusat.ac.in

Hydroxyapatite (HA) is a bioactive ceramic material that mimics the mineral composition of natural bone. This material does not possess acceptable mechanical properties for use as a bulk biomaterial; however, it does demonstrate significant potential for use as a coating on metallic orthopaedic and dental prostheses. Pulsed laser deposition (PLD) of thin films of HA on TiAl6V4 have shown crystalline coatings to be obtained at temperatures of the order of 350-500 degrees C. This condition of high substrate temperature promoted the oxidation of the substrate surface prior to the growth of the HA layer and the oxidation layer degraded the adhesion of the coating to the substrate. In this study, thin films of HA were deposited on TiAl6V4 alloy at a lower temperature of 200 degrees C by PLD and crystallized by a hydrothermal treatment at 100 degrees C. The film was subjected to mechanical as well as cell viability tests in vitro. The thickness, roughness, crystallanity, composition ratio, adhesive strength, and cell adhesion of the film suggest the application of this technique for producing bioactive implants.

PMID: 20092101 [PubMed - indexed for MEDLINE]

Green synthesis of gold nanoparticles using Cinnamomum zeylanicum leaf broth

Spectrochim Acta A Mol Biomol Spectrosc. 2009 Oct 15;74(3):735-9. Epub 2009 Aug 12.

Smitha SL, Philip D, Gopchandran KG.

Department of Optoelectronics, University of Kerala, Thiruvananthapuram 695581, Kerala, India.

Development of biologically inspired experimental processes for the synthesis of nanoparticles is an important branch of nanotechnology. The synthesis of gold nanoparticles using Cinnamomum zeylanicum leaf broth as the reducing agent is reported. The morphology of the particles formed consists of a mixture of gold nanoprisms and spheres with fcc (111) structure of gold. At lower concentrations of the extract, formation of prism shaped Au particles dominates, while at higher concentrations almost spherical particles alone are observed. Good crystallinity of the nanoparticles with fcc phase is evident from XRD patterns, clear lattice fringes in the high resolution TEM image and bright circular rings in the SAED pattern. Au nanoparticles grown are observed to be photoluminescent and the intensity of photoemission is found to increase with increase in leaf broth concentration. The ability to modulate the shape of nanoparticles as observed in this study for gold nanoparticles opens up the exciting possibility of developing further synthetic routes employing ecofriendly sources.

PMID: 19744880 [PubMed - indexed for MEDLINE]

In vitro study on the influence of methyl parathion on soil bacterial activity

J Environ Biol. 2009 May;30(3):417-9.

Bindhya R, Sunny SA, Thanga VS.

Department of Environmental Sciences, University of Kerala, Kariavattom Campus, Thiruvananathapuram, India.

A study was conducted to find out the effect of different concentrations of Methyl parathion, an organophosphorus pesticide on soil bacterial population, soil respiratory activity and dehydrogenase activity, under laboratory conditions for a definite time period. The higher concentration (100 ppm) of Methyl parathion application, considerably reduced bacterial count, CO2 evolution and enzyme activity in soil but the microbial activities seemed to recover several weeks following pesticide application.

PMID: 20120470 [PubMed - indexed for MEDLINE]