Hydrogen peroxide induced genomic instability in nucleotide excision repair-deficient lymphoblastoid cells

Copyright @ 2010 Gopalakrishnan et al; licensee BioMed Central Ltd.Background The Nucleotide Excision Repair (NER) pathway specialises in UV-induced DNA damage repair. Inherited defects in the NER can predispose individuals to Xeroderma Pigmentosum (XP). UV-induced DNA damage cannot account for the manifestation of XP in organ systems not directly exposed to sunlight. While the NER has recently been implicated in the repair of oxidative DNA lesions, it is not well characterised. Therefore we sought to investigate the role of NER factors Xeroderma Pigmentosum A (XPA), XPB and XPD in oxidative DNA damage-repair by subjecting lymphoblastoid cells from patients suffering from XP-A, XP-D and XP-B with Cockayne Syndrome to hydrogen peroxide (H2O2). Results Loss of functional XPB or XPD but not XPA led to enhanced sensitivity towards H2O2-induced cell death. XP-deficient lymphoblastoid cells exhibited increased susceptibility to H2O2-induced DNA damage with XPD showing the highest susceptibility and lowest repair capacity. Furthermore, XPB- and XPD-deficient lymphoblastoid cells displayed enhanced DNA damage at the telomeres. XPA- and XPB-deficient lymphoblastoid cells also showed differential regulation of XPD following H2O2 treatment. Conclusions Taken together, our data implicate a role for the NER in H2O2-induced oxidative stress management and further corroborates that oxidative stress is a significant contributing factor in XP symptoms. Resistance of XPA-deficient lymphoblastoid cells to H2O2-induced cell death while harbouring DNA damage poses a potential cancer risk factor for XPA patients. Our data implicate XPB and XPD in the protection against oxidative stress-induced DNA damage and telomere shortening, and thus premature senescence.This research is supported by the Defence Innovative Research Programme, Defence Science and Technology Agency, Singapore (POD: 0613592) and the Academic Research Fund, Ministry of Education, Singapore (T206B3108). Supported in part by a grant from British Council, PMI2 Connect (Grant Number: RC134)

Marine prawn farming along the coast of the Gulf of Kutch its prospects and problems

Along the 250 kilometer coastline of the Gulf of Kutch, there are no prawn farming activities Millions of juveniles of prawns ascending the creeks in the little Rann of Kutch are trapped by staked bag nets are marketed for meagre revenue. The fishermen remain in perpetual poverty due to drought prone conditions of the coast during remaining period of the year. A tidal range of 2.6 metres and high salinity conditions of the Gulf of Kutch necessitate capital investment for supply, retention and exchange of seawater in farming operations. The available seed are not of quick growing variety of prawns. An experimental project was initiated in 1979 firstly to explore the feasibility of utilisation of low saline reservoirs of solar salt works in Okha mandal for extensive prawn farming using the indigenous seed and there after to assess the culturability, economic viability and management problems associated with small scale intensive farming. During September 1986 to IVIarch 1987, seed of Penaeus mergulensis and Metapenaeus kutchensis @ 36332 nos/hectare were stocked in three ponds of 1.92 hectare each. A growth rate of 0.437 mm/day length and 0.056 gm/day weight in respect of the former and 0.33 mm/day length and 0.037 gm/day weight in respect of the latter species in 187 days of rearing was achieved. The harvested prawns were acceptable to freezing industry and fetched Rs. 14000-23000 (Headon) per tonne. The advantages of employment generation, economic up liftment and utilisation of the monsoon seed resources for farming are discussed

കൊച്ചിയുടെ കുതിപ്പിനൊപ്പം സി.എം.എഫ്.ആർ.ഐ

കൊച്ചിയുടെ കുതിപ്പിനൊപ്പം സി.എം.എഫ്.ആർ.ഐ Today Kochi 2015 വികസനം തപസ്യയാക്കിയ അഞ്ചു വർഷങ്ങ

Bond percolation of polymers

We study bond percolation of $N$ non-interacting Gaussian polymers of $\ell$ segments on a 2D square lattice of size $L$ with reflecting boundaries. Through simulations, we find the fraction of configurations displaying {\em no} connected cluster which span from one edge to the opposite edge. From this fraction, we define a critical segment density $\rho_{c}^L(\ell)$ and the associated critical fraction of occupied bonds $p_{c}^L(\ell)$, so that they can be identified as the percolation threshold in the $L \to \infty$ limit. Whereas $p_{c}^L(\ell)$ is found to decrease monotonically with $\ell$ for a wide range of polymer lengths, $\rho_{c}^L(\ell)$ is non-monotonic. We give physical arguments for this intriguing behavior in terms of the competing effects of multiple bond occupancies and polymerization.Comment: 4 pages with 6 figure

Ground Water Quality Assessment in Paper Mill Effluent Irrigated Area - Using Multivariate Statistical Analysis

Paper mill effluent while flowing, percolates through soil and slowly mixes with ground water bodies (Open well), water samples were collected from three stations (S1, S2 and S3) in and around paper mill. This paper represents the characteristics of ground water quality and the effect of paper mill effluent, which is using recycled water for irrigation and domestic purpose. Cluster analysis (CA), principal component analysis (PCA) and multidimensional scale plot (MDS) appear were employed to evaluate the tropic status of water quality for three monitoring stations. High pollution load was observed in the ground water bodies due to continuous flow of effluent near the ground water sources. Effluent water consists of 3400 mg/l suspended solids. However, pH varied from 5.5-7.6. The biochemical oxygen demand and chemical oxygen demand ranged from 2-780 and 60 - 1520 mg/l respectively. SAR, RSC and SSP level was high from S2 and S3, both were unsuitable for both domestic and irrigation purposes. An elevated coliform bacterial count indicates that these water samples S2 and S3 were not suitable for domestic purpose. The dendrogram of the effluent water quality parameters evidently indicate that Maruthi Paper mill does not meet nominal National standard set by central pollution control board to discharge in agricultural fiel

New particle formation by ion-induced nucleation during dissipation stage of thunderstorm

A case of new particle formation observed during dissipation stage of a thunderstorm at a tropical station, Pune, India on 3 June 2008 is reported. The flash rate and rainfall intensity increased as high as 110 flashes per 5 minutes and 150 mm hour-1 respectively during the active stage of thunderstorm, and then gradually decreased during the dissipation stage. The number concentration of particles in the size range of 10-100 nm sharply increased from 350 particles cm-3 to ~8000 particles cm-3 during the dissipation stage of a thunderstorm and grew to larger diameter subsequently. Observations suggest that the atmospheric conditions such as (i) reduced background aerosol concentration after heavy rain, (ii) high humidity condition, and (iii) increased ion concentration during the dissipation stage by corona discharges, favoured generation of new particles by ion-induced nucleation (IIN). Observations also suggest that generation of unipolar ions by corona discharges may be more favourable for IIN and subsequent growth of the particles