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Madhusudan Das

Bio: Madhusudan Das is an academic researcher from University of Calcutta. The author has contributed to research in topics: Population & Single-nucleotide polymorphism. The author has an hindex of 14, co-authored 56 publications receiving 539 citations.


Papers
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Journal ArticleDOI
TL;DR: Evaluation of the micronuclei formation in oral mucosa cells, urothelial cells and peripheral blood lymphocytes was carried out in symptomatic individuals exposed to arsenic through drinking water in West Bengal, India and results indicate that the symptomatic Individuals exposed to arsenicism through drinkingWater in this region have significant cytogenetic damage.
Abstract: In West Bengal, India arsenic in ground water has been found to be above the maximum permissible limit in seven districts covering an area of 37,493km2. In the present study, evaluation of the micronuclei (MN) formation in oral mucosa cells, urothelial cells and peripheral blood lymphocytes was carried out in the symptomatic individuals exposed to arsenic through drinking water. Forty five individuals with cutaneous signs of arsenicism from four affected districts (368.11 microg/l of As in drinking water) were considered as the exposed group and 21 healthy individuals with no symptoms of arsenic poisoning and residing in two unaffected districts (5.49 microg/l of As) were considered as controls. The exposed and control groups had similar age distribution and socioeconomic status. Standardised questionnaires were utilised and medical examination was conducted to ascertain exposure history, sociodemographic characteristics, diet, health, medication, addiction and chief symptoms in the study participants. Arsenic exposure was confirmed by measuring the arsenic content in the drinking water, nails, hair and urine samples from the volunteers. Arsenic contents in the urine, nail and hair in the exposed group were 24.45 microg/l, 12.58 and 6.97 microg/g, respectively which were significantly high in comparison to corresponding control group values of 4.88 microg/l, 0.51 and 0.34 microg/g, respectively. Exposed individuals showed a statistically significant increase in the frequency of MN in oral mucosa, urothelial cells and lymphocytes (5.15, 5.74 and 6.39/1000 cells, respectively) when compared with the controls (0.77, 0.56 and 0.53/1000 cells, respectively). Thus, the above results indicate that the symptomatic individuals exposed to arsenic through drinking water in this region have significant cytogenetic damage.

104 citations

Journal ArticleDOI
24 Jun 2015-PLOS ONE
TL;DR: Genotype and allele frequency analysis of SNPs revealed that, rs1801725 (Ala986Ser), rs1042636 (Arg990Gly) of CaSR gene and rs219778, rs219780 (Thr229Thr) of CLDN14 gene were significantly associated with KSD.
Abstract: Kidney stone disease (KSD) is a major clinical problem imposing a large burden for both healthcare and economy globally. In India, the prevalence of kidney stone disease is rapidly increasing. This study aimed to evaluate the association between genetic defects in vitamin D receptor (VDR), calcium sensing receptor (CaSR) and claudin 14 (CLDN14) genes and kidney stone disease in patients from eastern India. We enrolled 200 consecutive kidney stone patients (age 18–60 years) (cases) and their corresponding sex and age matched 200 normal individuals (controls). To identify genetic variants responsible for KSD, we performed sequence analysis of VDR, CaSR and CLDN14 genes. Four non-synonymous (rs1801725, rs1042636, rs1801726 and rs2228570), one synonymous (rs219780) and three intronic single nucleotide polymorphisms (SNPs) (rs731236, rs219777 and rs219778) were identified. Genotype and allele frequency analysis of these SNPs revealed that, rs1801725 (Ala986Ser), rs1042636 (Arg990Gly) of CaSR gene and rs219778, rs219780 (Thr229Thr) of CLDN14 gene were significantly associated with KSD. Serum calcium levels were significantly higher in subjects carrying 986Ser allele and calcium excretion was higher in subjects bearing 990Gly allele. In conclusion, rs1801725, rs1042636, rs219778 and rs219780 SNPs were associated with kidney stone risk in patients from the eastern part of India.

49 citations

Journal ArticleDOI
TL;DR: In India, chloroquine has been replaced by a combination of artesunate and sulfadoxine-pyrimethamine (AS-SP) for uncomplicated P. falciparum malaria, and artemether-lumefantrine and artesUNate-mefloquine are effective alternatives to the artes unate-sulfadoxines-pyrethamines combination.
Abstract: In India, chloroquine has been replaced by a combination of artesunate and sulfadoxine-pyrimethamine (AS-SP) for uncomplicated P. falciparum malaria. Other available combinations, artemether-lumefantrine (AM-LF) and artesunate-mefloquine (AS-MQ), not included in the national program, are widely used by private practitioners. Little is known about the therapeutic efficacy of these artemisinin combinations and the prevalence of molecular markers associated with antimalarial drug resistance. A total of 157 patients with P. falciparum monoinfection were recruited and randomized into three study groups (AS-SP, AM-LF, and AS-MQ). All patients were followed up for 42 days to study the clinical and parasitological responses according to the WHO protocol (2009). We assessed the polymorphism of the pfATPase6 , pfcrt , pfdhfr , and pfdhps genes by the DNA-sequencing method. The PCR-corrected therapeutic efficacies of AS-SP, AM-LF, and AS-MQ were 90.6% (95% confidence interval [CI], 0.793 to 0.969), 95.9% (95% CI, 0.860 to 0.995), and 100% (95% CI, 0.927 to 1.00), respectively. No specific mutational pattern was observed in the pfATPase6 gene. All isolates had a K76T mutation in the pfcrt gene. In the pfdhfr-pfdhps genotype, quadruple mutation was frequent, and quintuple mutation was documented in 6.3% of P. falciparum isolates. The significant failure rate of AS-SP (9.5%), although within the limit (10%) for drug policy change, was due to SP failure because of prevailing mutations in pfdhfr , I 51 R 59 N 108 , with pfdhps , G 437 and/or E 540 . The efficacy of this ACT needs periodic monitoring. Artemether-lumefantrine and artesunate-mefloquine are effective alternatives to the artesunate-sulfadoxine-pyrimethamine combination.

38 citations

Journal ArticleDOI
TL;DR: It is not the quality of water, rather the quantity of water consumed that matters most in the occurrence of KSD.
Abstract: Purpose The combined interaction of epidemiology, environmental exposure, dietary habits, and genetic factors causes kidney stone disease (KSD), a common public health problem worldwide. Because a high water intake (>3 L daily) is widely recommended by physicians to prevent KSD, the present study evaluated whether the quantity of water that people consume daily is associated with KSD and whether the quality of drinking water has any effect on disease prevalence. Materials and Methods Information regarding residential address, daily volume of water consumption, and source of drinking water was collected from 1,266 patients with kidney stones in West Bengal, India. Drinking water was collected by use of proper methods from case (high stone prevalence) and control (zero stone prevalence) areas thrice yearly. Water samples were analyzed for pH, alkalinity, hardness, total dissolved solutes, electrical conductivity, and salinity. Average values of the studied parameters were compared to determine if there were any statistically significant differences between the case and control areas. Results We observed that as many as 53.6% of the patients consumed <3 L of water daily. Analysis of drinking water samples from case and control areas, however, did not show any statistically significant alterations in the studied parameters. All water samples were found to be suitable for consumption. Conclusions It is not the quality of water, rather the quantity of water consumed that matters most in the occurrence of KSD.

37 citations

Journal ArticleDOI
TL;DR: Low dose irradiation in combination with frozen storage effectively preserved the mechanical attributes, visual quality and improved the microbial safety of the prawns during long term storage and could satisfy the increasing consumer demand for high quality, minimally processed, additive-free sea foods.
Abstract: The study was carried out on two important species of prawns (Macrobrachium rosenbergii and Penaeus monodon) aimed at understating the effect of increasing irradiation doses (0.5, 1.5, 2.5, 3, 5, 10 and 20 kGy) on their structural components studied by histology and x-ray diffraction and to determine the effect of irradiation and frozen storage on the mechanical properties (shear force, toughness and cohesiveness), visual appearance and microbiological quality (total bacterial count, mould count, coliform count and detection of Salmonella) of prawns during storage for 56 days. Low dose irradiation (≤10 kGy) induced no significant changes in microstructure and mechanical properties in fresh prawns. Structural changes became apparent at 20 kGy, although they failed to induce any significant effect on the muscle firmness, toughness and cohesiveness. Irradiation with 2.5 kGy and above reduced melanosis in both the species. Low dose irradiation (1.5–3 kGy) significantly reduced the total bacterial and mould counts and eliminated coliforms and Salmonella. Low dose irradiation (2.5–5 kGy) in combination with frozen storage effectively preserved the mechanical attributes, visual quality and improved the microbial safety of the prawns during long term storage. The technique could satisfy the increasing consumer demand for high quality, minimally processed, additive-free sea foods.

31 citations


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Journal ArticleDOI
TL;DR: This review will try to integrate all of the issues of mechanism of arsenic carcinogenesis in the past, with a strong bias toward effects that are produced by environmentally relevant arsenic concentrations.
Abstract: Epidemiological evidence shows an association between inorganic arsenic in drinking water and increased risk of skin, lung and bladder cancers. The lack of animal models has hindered mechanistic studies of arsenic carcinogenesis in the past, but some promising new models for these cancers are now available. The various forms of arsenic to which humans are exposed, either directly or via metabolism of inorganic arsenic to various methylated forms, further complicate the issue of mechanism, since these compounds can have different effects, both genotoxic and non-genotoxic. This review will try to integrate all of these issues, with a strong bias toward effects that are produced by environmentally relevant arsenic concentrations.

526 citations

Journal ArticleDOI
TL;DR: The harmonization and standardization of the buccal MN assay will allow more reliable comparison of the data among human populations and laboratories, evaluation of the assay's performance, and consolidation of its world-wide use for biomonitoring of DNA damage.
Abstract: The micronucleus (MN) assay in exfoliated buccal cells is a useful and minimally invasive method for monitoring genetic damage in humans. This overview has concluded that although MN assay in buccal cells has been used since the 1980s to demonstrate cytogenetic effects of environmental and occupational exposures, lifestyle factors, dietary deficiencies, and different diseases, important knowledge gaps remain about the characteristics of micronuclei and other nuclear abnormalities, the basic biology explaining the appearance of various cell types in buccal mucosa samples and effects of diverse staining procedures and scoring criteria in laboratories around the world. To address these uncertainties, the human micronucleus project (HUMN; see http://www.humn.org) has initiated a new international validation project for the buccal cell MN assay similar to that previously performed using human lymphocytes. Future research should explore sources of variability in the assay (e.g. between laboratories and scorers, as well as inter- and intra-individual differences in subjects), and resolve key technical issues, such as the method of buccal cell staining, optimal criteria for classification of normal and degenerated cells and for scoring micronuclei and other abnormalities. The harmonization and standardization of the buccal MN assay will allow more reliable comparison of the data among human populations and laboratories, evaluation of the assay's performance, and consolidation of its world-wide use for biomonitoring of DNA damage.

512 citations

01 Jan 2012
TL;DR: PReVIously ClAssIfIed by IARC As “CARCInogenIC to humAns (gRoup 1)” And wAs deVeloped by sIx sepARAte woRkIng gRoups: phARmACeutICAls; bIologICAl Agents; ARsenIC, metAls, fIbRes, And dusts; RAdIAtIon; peRsonAl
Abstract: pReVIously ClAssIfIed by IARC As “CARCInogenIC to humAns (gRoup 1)” And wAs deVeloped by sIx sepARAte woRkIng gRoups: phARmACeutICAls; bIologICAl Agents; ARsenIC, metAls, fIbRes, And dusts; RAdIAtIon; peRsonAl hAbIts And IndooR CombustIons; ChemICAl Agents And RelAted oCCupAtIons. thIs Volume 100f CoVeRs ChemICAl Agents And RelAted oCCupAtIons, speCIfICAlly 4-AmInobIphenyl, benzIdIne, dyes metAbolIzed to benzIdIne, 4,4’-methylenebIs(2-ChloRoAnIlIne), 2-nAphthylAmIne, oRtho-toluIdIne, AuRAmIne And AuRAmIne pRoduCtIon, mAgentA And mAgentA pRoduCtIon, benzo[A]pyRene, CoAl gAsIfICAtIon, oCCupAtIonAl exposuRes duRIng CoAl-tAR dIstIllAtIon, CoAl-tAR pItCh, Coke pRoduCtIon, untReAted oR mIldly tReAted mIneRAl oIls, shAle oIls, soot, As found In oCCupAtIonAl exposuRe of ChImney-sweeps, oCCupAtIonAl exposuRes duRIng AlumInIum pRoduCtIon, AflAtoxIns, benzene, bIs(ChloRomethyl)etheR And ChloRomethyl methyl etheR, 1,3-butAdIene, 2,3,7,8-tetRAChloRodIbenzo-pARA-dIoxIn, 2,3,4,7,8-pentAChloRodIbenzofuRAn, And 3,3’,4,4’,5-pentAChloRobIphenyl, ethylene oxIde, foRmAldehyde, sulfuR mustARd, VInyl ChloRIde, IsopRopyl AlCohol mAnufACtuRe by the stRong-ACId pRoCess, mIsts fRom stRong InoRgAnIC ACIds, oCCupAtIonAl exposuRes duRIng IRon And steel foundIng, oCCupAtIonAl exposuRe As A pAInteR, oCCupAtIonAl exposuRes In the RubbeR mAnufACtuRIng IndustRy. beCAuse the sCope of Volume 100 Is so bRoAd, Its monogRAphs ARe foCused on key InfoRmAtIon. eACh monogRAph pResents A desCRIptIon of A CARCInogenIC Agent And how people ARe exposed, CRItICAl oVeRVIews of the epIdemIologICAl studIes And AnImAl CAnCeR bIoAssAys, And A ConCIse ReVIew of the Agent’s toxICokInetICs, plAusIble meChAnIsms of CARCInogenesIs, And potentIAlly susCeptIble populAtIons, And lIfe-stAges. detAIls of the desIgn And Results of IndIVIduAl epIdemIologICAl studIes And AnImAl CAnCeR bIoAssAys ARe summARIzed In tAbles. shoRt tAbles thAt hIghlIght key Results ARe pRInted In Volume 100, And moRe extensIVe tAbles thAt InClude All studIes AppeAR on the monogRAphs pRogRAmme websIte (http://monogRAphs.IARC.fR). It Is hoped thAt thIs Volume, by CompIlIng the knowledge ACCumulAted thRough seVeRAl deCAdes of CAnCeR ReseARCh, wIll stImulAte CAnCeR pReVentIon ACtIVItIes woRldwIde, And wIll be A VAlued ResouRCe foR futuRe ReseARCh to IdentIfy otheR Agents suspeCted of CAusIng CAnCeR In humAns. D es ig n by A ude la d es m ot s

378 citations

Journal ArticleDOI
TL;DR: The role of arsenic in the development of cancer is elucidated in the context of combined epidemiological and biological studies, however, further analyses by means of molecular epidemiology are needed to improve the understanding of cancer aetiology induced by arsenic.
Abstract: Arsenic, one of the most significant hazards in the environment affecting millions of people around the world, is associated with several diseases including cancers of skin, lung, urinary bladder, kidney and liver. Groundwater contamination by arsenic is the main route of exposure. Inhalation of airborne arsenic or arsenic-contaminated dust is a common health problem in many ore mines. This review deals with the questions raised in the epidemiological studies such as the dose-response relationship, putative confounders and synergistic effects, and methods evaluating arsenic exposure. Furthermore, it describes the metabolic pathways of arsenic, and its biological modes of action. The role of arsenic in the development of cancer is elucidated in the context of combined epidemiological and biological studies. However, further analyses by means of molecular epidemiology are needed to improve the understanding of cancer aetiology induced by arsenic.

303 citations

Journal ArticleDOI
TL;DR: The pathomechanisms of arsenic skin cancer and the relationship to its characteristic figures are discussed, critical for understanding the molecular mechanism for arsenic carcinogenesis in other internal organs.
Abstract: Chronic arsenic poisoning is a world public health issue. Long-term exposure to inorganic arsenic (As) from drinking water has been documented to induce cancers in lung, urinary bladder, kidney, liver and skin in a dose-response relationship. Oxidative stress, chromosomal abnormality and altered growth factors are possible modes of action in arsenic carcinogenesis. Arsenic tends to accumulate in the skin. Skin hyperpigmentation and hyperkeratosis have long been known to be the hallmark signs of chronic As exposure. There are significant associations between these dermatological lesions and risk of skin cancer. The most common arsenic-induced skin cancers are Bowen's disease (carcinoma in situ), basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Arsenic-induced Bowen's disease (As-BD) is able to transform into invasive BCC and SCC. Individuals with As-BD are considered for more aggressive cancer screening in the lung and urinary bladder. As-BD provides an excellent model for studying the early stages of chemical carcinogenesis in human beings. Arsenic exposure is associated with G2/M cell cycle arrest and DNA aneuploidy in both cultured keratinocytes and As-BD lesions. These cellular abnormalities relate to the p53 dysfunction induced by arsenic. The characteristic clinical figures of arsenic-induced skin cancer are: (i) occurrence on sun-protected areas of the body; (ii) multiple and recrudescent lesions. Both As and UVB are able to induce skin cancer. Arsenic treatment enhances the cytotoxicity, mutagenicity and clastogenicity of UV in mammalian cells. Both As and UVB induce apoptosis in keratinocytes by caspase-9 and caspase-8 signaling, respectively. Combined UVB and As treatments resulted in the antiproliferative and proapoptotic effects by stimulating both caspase pathways in the keratinocytes. UVB irradiation inhibited mutant p53 and ki-67 expression, as well as increased in the number of apoptotic cells in As-BD lesions which resulted in an inhibitory effect on proliferation. As-UVB interaction provides a reasonable explanation for the rare occurrences of arsenical cancer in the sun-exposed skin. The multiple and recurrent skin lesions are associated with cellular immune dysfunction in chronic arsenism. A decrease in peripheral CD4+ cells was noticed in the inhabitants of arsenic exposure areas. There was a decrease in the number of Langerhans cells in As-BD lesion which results in an impaired immune function on the lesional sites. Since CD4+ cells are the target cell affected by As, the interaction between CD4+ cells and epidermal keratinocytes under As affection might be closely linked to the pathogenesis of multiple occurrence of arsenic-induced skin cancer. In this review, we provide and discuss the pathomechanisms of arsenic skin cancer and the relationship to its characteristic figures. Such information is critical for understanding the molecular mechanism for arsenic carcinogenesis in other internal organs.

260 citations