Browsing by Author "Chandra, Abhishek"

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    Amniotic membrane transplantation in ocular surface disorders.
    (2005-07-22) Chandra, Abhishek; Maurya, O P S; Reddy, Bhaskar; Kumar, Gaurav; Pandey, Kshama; Bhaduri, Gautam
    In this prospective study, 81 eyes of 70 patients diagnosed with various ocular surface disorders were enrolled to document the use of amniotic membrane transplantation in various ocular surface disorders. Detailed history and ocular examination was done. Ocular photographs and consent from all patients were taken. Fluorescein staining and impression cytology was done preoperatively and postoperatively in selected cases. Amniotic membrane was prepared from the placenta of a donor (consent taken and negative for infectious disorders), after separating amnion from chorion. It was washed with antibiotic solutions, transferred over nitrocellulose paper and stored in Dulbecco's modified Eagle's minimum essential medium at -80 degrees C. Recipient bed was prepared by removing the fibrovascular pannus and necrosed conjunctiva. Amniotic membrane was transplanted with the epithelial side up and sutured. Sixty-four eyes had good result by clinical evaluation or impression cytology findings, 5 eyes later required limbal stem cell culture and transplantation. All the 3 eyes had failure of the fornix reconstruction and 5 eyes had recurrence of the pterygium. Amniotic membrane provides lower recurrence rate in cases of recurrent pterygium. Alkali injuries are more dangerous but showed good response to amniotic membrane transplantation combined with limbal autografting or ex-vivo expansion and later transfer. Initial proper assessment of limbal involvement, conjunctival necrosis and corneal involvement is the key to the management of acute cases. Contracted sockets showed no improvement. Shield ulcers and persistent epithelial defect and ocular surface defects secondary to tumour excision showed excellent results.
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    Conservation of groundwater by artificial recharge in Delhi and Haryana state of India – A review.
    (2010-11) Saxena, Pallavi; Chandra, Abhishek; Garg, Abhinav; Sharma, Gaurav; Varma, Prateek
    ABSTRACT: The water scarcity is one of the major issue which is yet to not solve completely and depletion of the water table has become a major problem across the world. Demands for water increases as our population grow. Though 75% of the earth is covered by water, only a small percentage of it is fit for human use. The excessive demand has put a strain on our water resources. In many areas groundwater, which makes about 20% of our fresh water supply, is being used extensively for a variety of human, agriculture and industrial use. The recharge rate is much less than the rate at which the water is being pumped out. This overexploitation has a lot of environmental effects which include degradation of water quality, reduced quantity of water in wells and springs, and land subsidence to name a few. In India the groundwater problem is more prominent in areas with a high agriculture economy, though it is high in urban areas also. The overexploitation in the National Capital Delhi has reduced the water table depth by a considerable amount in the last 5 years. Artificial methods to recharge the groundwater can be used to supplement our water resources. Different methods, based on the climatic and geographical conditions, can be used. In dry areas, for example, watersheds can and are being used to manage water resources. In this paper we have reviewed and summarized different studies to suggest a variety of methods to recharge groundwater. Artificial recharging of aquifer is one of the option, in order to improve groundwater crises which is sustainable in the long term. Some of the techniques are already been used and many could also be easily put in use by the villagers with local resources availability in terms of manpower and materials (www.megphed.gov.in). We have studied the groundwater recharge process in relation to the climatic and geographical conditions and make a list of pros and cons for different methods with secondary date available in literature. Moreover, in support of this we have also narrate the case studies of two states (Site–1 and Site–2) to explain the conservation of groundwater by artificial recharge. The overall efficiency of the methods used to artificially recharge groundwater have sufficiently explained.
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    Role of anti-oxidant enzymes superoxide dismutase and catalase in the development of cataract : study of serum levels in patients with senile and diabetic cataracts.
    (2006-07-24) Maurya, O P S; Mohanty, Lipa; Bhaduri, Gautam; Chandra, Abhishek
    Cataract is a universal phenomenon in old age and the most common cause of blindness worldover. Oxidative stress is believed to be a key factor in the gradual loss of transparency of lens. Free radicals formed result in derangement and opacification of lens fibres. Superoxide dismutase, catalase and glutathione peroxidase are major anti-oxidant enzymes, which protect against free radicals. The purpose of this study is to evaluate the role of anti-oxidant enzymes - superoxide dismutase and catalase in the development of cataract in senile and diabetic persons. Serum levels of major anti-oxidant enzymes-superoxide dismutase and catalase were estimated in 20 patients with diabetic cataract, and matched with another 20 patients of senile cataract taken as control. Estimation of superoxide dismutase was done by improved spectrophotometric assay based on epinephrine auto-oxidation at 480nm, while catalase estimation was done by the method of Hugo Aebi. The mean serum levels of superoxide dismutase and catalase were lower as age increased. These enzymes were also significantly lower in diabetic cataracts (9.13 and 16.42 units/ml) as compared to senile cataracts (25.30 and 57.27units/ml). Oxidative stress is one of the major factors contributing to cataract formation. In diabetics where there is increased oxidative stress, the serum levels of the major anti-oxidant enzymes decrease, which lead to early cataract formation. It may be concluded that oxidative stress is an important factor in the development of diabetic cataracts and anti-oxidants may have a role in decreasing the incidence of cataract.