Bidhan Chandra Ray

Environmental and Familial Risk Factors of Parkinsons Disease: Case-Control Study

BACKGROUND While the cause of Parkinsons disease (PD) remains unknown, evidence suggests certain environmental factors, such as well water drinking, herbicides, pesticides exposure and neurotoxins, may trigger the chain of oxidative reactions culminating in the death of dopaminergic neurons in substantia nigra to cause Parkinsonism. To investigate the possible impact of environmental risk factors for idiopathic PD, a case-control study was performed in the Eastern India. METHODS During the period from January 1st, 2006 and December 10th, 2009, 175 PD patients (140 men, 35 women) and 350 non-Parkinson age-sex matched controls were included in the study. Subjects were given a structured neurological examination and completed an administered questionnaire which elicited detailed information on demographic data, pesticides, herbicides family history, occupation, dietary and smoking habits. RESULTS The multivariate analysis revealed that family history of PD, pesticide exposure, exposure to toxins other than pesticides and herbicides, rural living and previous history of depression were associated with increased risk of PD, whereas, smoking appeared to be a protective factor. Well water drinking for at least five years, though a significant risk factor on univariate analysis (OR = 4.5, 95% CI = 2.1-9.9), could not be proved significant in multivariate analysis. Head trauma, vegetarian dietary habit, occupation involving physical exertion and exposure to domestic pets were not as significant risk factors. CONCLUSION Results of our study support the hypothesis of multifactorial etiology of PD with environmental factors acting on a genetically susceptible host.

A novel spectrofluorimetric method for the ultra trace analysis of nitrite and nitrate in aqueous medium and its application to air, water, soil and forensic samples

A highly sensitive and virtually specific method has been developed for the trace and ultra trace 5ngml(-1)-1mugml(-1) fluorimetric analysis of nitrite. The method is based on the quenching action of nitrite on the native fluorescence of murexide (ammonium purpurate) [lambda(ex)=349.0nm, lambda(em)=444.5nm] in the acid range of 0.045-0.315 (M) H(2)SO(4). The method is very precise and accurate (S.D.=+/-0.4877 and R.S.D.=0.4878% for the determination of 0.1mugml(-1) of nitrite in 11 replicates). Relatively large excesses of over 35 cations and anions do not interfere. The proposed technique has been successfully applied for the determination of nitrite and nitrate in ground water, surface water and sea water, nitrite in soil and nitrate in forensic samples. The method has also been extended for the analysis of NO(x) in air.

Rapid and sensitive method for simultaneous determination of six carcinogenic aromatic amines in mainstream cigarette smoke by liquid chromatography/electrospray ionization tandem mass spectrometry

Aromatic amines are one of the sources of carcinogenicity in cigarette and tobacco smoke. Accurate quantification of these chemicals is needed to assess public health risk. A new validated rapid, sensitive and analyte specific liquid chromatography/electrospray ionization tandem mass spectrometric (LC/MS/MS) method has been developed for the simultaneous determination of six aromatic amines in mainstream cigarette smoke using research reference cigarette 2R4F. Three popular Indian brand cigarettes were also analyzed using the same procedure. The limit of detection of this method ranged from 0.04 to 0.59 ng/cig using an injection volume of 7 microl. The identification of each amine was established by chromatographic retention times, analyte specific fragmentation pattern and relative peak area ratios of two product/precursor ion pairs. The method showed excellent reproducibility and was also rapid, selective and robust for aromatic amine determination from cigarette smoke.

A SELECTIVE KINETIC METHOD FOR THE ESTIMATION OF BENZYL ALCOHOL IN CLOSELY RELATED MIXTURES

Ethylenebis(biguanide)silver(III) ion quantitatively oxidises benzyl alcohol and its derivatives (XC6H4CH2OH; X = H, CH3, Cl or NO2, substituents in ortho or para position). The difference in reaction rates for different alcohols has been utilised in developing a kinetic method for the estimation of benzyl alcohol (2.0–40.0 mmol dm−3) in the presence of a large number of closely related alcohols and hydroxy compounds. The relative standard deviation for ten replicate measurements of 5 mmol dm−3 benzyl alcohol is 1.5%. The method was satisfactorily applied to analyse real samples.

Determination of pyridine, 2-picoline, 4-picoline and quinoline from mainstream cigarette smoke by solid-phase extraction liquid chromatography/electrospray ionization tandem mass spectrometry

The present paper describes the development and validation of a new reversed-phase liquid chromatography-electrospray ionization tandem mass spectrometric method (RP-HPLC-ESI-MS/MS) for simultaneous determination of pyridine, 2-picoline, 4-picoline and quinoline from mainstream cigarette smoke. Liquid-liquid extraction followed by solid-phase extraction was applied to extract the target analytes from cigarette smoke. Baseline chromatographic separation was achieved by utilizing a Zorbax SB-Aq (4.6x150 mm, 5 microm) column in gradient chromatographic conditions with acetonitrile and ammonium acetate buffer as mobile phases. Popular commercially available Indian brand filtered and non-filtered cigarettes were analyzed using the same method. The identification of each chemical was established by chromatographic retention times, analyte specific fragmentation patterns and relative peak area ratios of two product/precursor ion pairs. The limit of detection of this method ranged from 1.74 to 14.32 ng/cig using an injection volume of 20 microl. The reproducibility of this method is excellent and better standard deviations were obtained compared to literature reported values for these chemicals. RSD value is less than 9% for all analytes.

Peripheral markers for oxidative stress in Parkinson’s disease patients of Eastern India

Oxidative stress is thought to play a major role in the pathogenesis of Parkinson’s disease (PD). Neurons are highly susceptible to a defective antioxidant scavenging system, thus inducing oxidative changes in human red blood cells (RBCs), in vivo and in vitro. Previous studies on oxidative stress in RBCs in patients with PD have yielded controversial results claiming unaltered activity to reduced activity. We have thus undertaken this study to investigate the possibility of oxidative damage to the RBCs in PD by measuring the cytosolic antioxidant enzymes viz., catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (G-Px). The biochemical parameters were measured in erythrocytes of 80 PD patients and 80 normal age-matched healthy controls. The enzymes activities were correlated with age of patients, age of onset of disease, duration of disease, United Parkinson’s Disease Rating Scale (UPDRS) and Hoehn and Yahr stage. Patients with PD had higher red blood corpuscle (RBC) activity of SOD. The CAT, and G-Px activities were significantly lower in patients with PD compared to the controls. Erythrocyte SOD, CAT and G-Px were markedly lower in those PD patients who were suffering for a greater duration of the disease and in advanced cases of PD. A significant (P < 0.05) negative correlation of enzyme activities with disease duration, UPDRS score and Hoehn and Yahr stage of the disease was found. Results of our present study concludes the implication of oxidative stress as one of the risk factors, which can initiate or promote neurodegeneration in PD by playing a role in dopaminergic neuronal loss and was correlated to the severity of the disease.

Absence of Commonly Reported Leucine-Rich Repeat Kinase 2 Mutations in Eastern Indian Parkinson's Disease Patients

BACKGROUND Pathogenic mutations in leucine-rich repeat kinase 2 (LRRK2; PARK8) encoding dardarin, implicated in patients with autosomal dominant and sporadic Parkinsons disease (PD) among different ethnic groups (Ashkenazi Jews, North African Arabs, Basques) might be of some help in diagnostic screening and genetic counseling. AIM OF THE STUDY We investigated the seven common mutations spanning exons 31, 35, and 41 reported in the LRRK2 gene among Eastern Indian patients with PD. METHODS Mutations R1441G, R1441C, R1441H, G2019S, Y1699C, I2020T, and I2012T were screened in 320 individuals (PD, 150 and controls, 170) by direct sequencing. RESULTS We did not observe any of these abovementioned mutations in our studied individuals. CONCLUSION We conclude that these mutations are rare causes of PD in the Eastern Indian population and, therefore, of little help for genetic counseling and diagnostic purposes.

Selective liquid phase benzyl alcohol oxidation over Cu-loaded LaFeO3 perovskite

Copper loaded LaMO3 (M = Mn, Fe and Co) perovskites have been synthesized by a single-step solution combustion method. These materials have been investigated for liquid phase oxidation of benzyl alcohol using tertiary butyl hydrogen peroxide (TBHP) as oxidant in air at 80 °C under ambient pressure. Among these, the 10 at% Cu-loaded LaFeO3 has shown the best activity i.e., ∼99% conversion with complete benzaldehyde selectivity. The formation of perovskite phase was confirmed from XRD and the presence of Cu2+ was confirmed by XPS analysis. The higher activity of the combustion synthesized catalyst has been ascribed to the presence of a poorly defined surface structure containing an amorphous CuO phase wrapping the LaFeO3 particle, as evidenced from the HRTEM analysis. The catalyst recycling tests have shown a negligible loss of activity in the consecutive cycles.

Analytical Study of an Environmentally Hazardous Element, Arsenic, by Indirect Spectrofluorimetric Method in Diverse Fields

Abstract An inexpensive and virtually specific non‐extractive method for the determination of arsenic(III) at trace and ultra trace levels (5 ng mL−1–1 µg mL−1) in 0.09–0.45 (M) sulphuric acid has been developed. The method is based on the quantitative oxidation of arsenic(III) by chromium(VI) in the presence of iodine as catalyst. A known excess of chromium(VI) was taken and after oxidation of arsenic (III) the leftover chromium(VI) quantitatively quenches the fluorescence developed by murexide in acid medium. Measurement of the fluorescence intensity was carried out at 424 nm with excitation at 336 nm. The measurement is repeated without arsenic(III) addition and the increase in fluorescence intensity gives arsenic(III) concentration with the help of a calibration graph. The method is very precise and accurate [s.d. = ±0.71 and r.s.d. = 0.71% for the determination of 0.1 µg mL−1 of arsenic(III) in 11 replicates]. Relatively large excesses of over 35 cations and anions do not interfere. The method has been successfully applied for arsenic determination in various complex matrices, certified reference materials (alloys), and environmental and biological samples.

A novel indirect spectrofluorimetric method for the ultra trace analysis of a highly toxic metalloid-antimony in aqueous medium and its application to metallurgical, medicinal, and biological samples

ABSTRACT An inexpensive, virtually specific, non‐extractive method for the determination of antimony (III) at trace and ultra trace levels (5 ng mL−1–1 µg mL−1) in 0.09–0.45 (M) sulfuric acid has been developed. A known excess of chromium (VI) is allowed to quantitatively oxidise antimony (III) in the presence of iodine as catalyst, followed by addition of known excess of murexide (ammonium purpurate), where the unreacted chromium (VI) quantitatively quenches the fluorescence of murexide in acid medium, and measurement of the fluorescence intensity (λex = 336 nm, λem = 424 nm). The measurement is repeated without antimony (III) addition and the increase in fluorescence intensity gives the concentration of antimony (III) with the help of a calibration graph. The method is very precise and accurate (S.D. = ±0.2248 and R.S.D. = 0.2249% for the determination of 0.1 µg mL−1 of antimony (III) in 11 replicates). Relatively large excesses of over 35 cations and anions do not interfere. The method has been successfully applied for antimony determination in various complex matrices, certified reference materials (alloys), commercially available solder and lead samples, medicinal and biological samples.