<div align="justify">Working in night shifts may hinder the body's ability to repair DNA damage caused by normal cellular processes, scientists including one of Indian origin warn.<br /><br />Researches including those from Duke University in the US had previously had found that day sleep was associated with lower levels in their urine of a chemical by-product of active DNA tissue repair called 8-OH-dG than night sleep-potentially indicating reduced capacity to repair cellular damage.<br /><br />In the new study, they measured 8-OH-dG levels in the stored urine samples of 50 night out of the 223 night shift workers.<br /><br />These 50 people had exhibited the widest discrepancies in levels of circulating melatonin between night work and night sleep.<br /><br />Analysis of the urine samples showed that melatonin levels were much lower when taken during a night shift than when taken during a normal night's sleep, researchers said.<br /><br />After taking account of potentially influential factors, such as alcohol consumption and shorter sleep duration (average 5.5 hours) during the day preceding a night shift, 8 -OH-dG levels were only 20 per cent of those observed during a normal night's sleep (average 7.5 hours).<br /><br />"Our results indicate that, relative to night sleep, reduced melatonin production among shift workers during night work is associated with significantly reduced urinary excretion of 8-OH-dG," researchers including Parveen Bhatti from Fred Hutchinson Cancer Research Centre in the US said.<br /><br />A particular pathway called NER is thought to be involved in the repair of DNA damage caused by oxygen free radicals, which are produced during normal cellular activity, researchers said.<br /><br />Research has shown that melatonin production boosts the activity of the genes involved in the NER pathway, they said.<br /><br />The study was published in the British Medical Journal.</div>
<div align="justify">Working in night shifts may hinder the body's ability to repair DNA damage caused by normal cellular processes, scientists including one of Indian origin warn.<br /><br />Researches including those from Duke University in the US had previously had found that day sleep was associated with lower levels in their urine of a chemical by-product of active DNA tissue repair called 8-OH-dG than night sleep-potentially indicating reduced capacity to repair cellular damage.<br /><br />In the new study, they measured 8-OH-dG levels in the stored urine samples of 50 night out of the 223 night shift workers.<br /><br />These 50 people had exhibited the widest discrepancies in levels of circulating melatonin between night work and night sleep.<br /><br />Analysis of the urine samples showed that melatonin levels were much lower when taken during a night shift than when taken during a normal night's sleep, researchers said.<br /><br />After taking account of potentially influential factors, such as alcohol consumption and shorter sleep duration (average 5.5 hours) during the day preceding a night shift, 8 -OH-dG levels were only 20 per cent of those observed during a normal night's sleep (average 7.5 hours).<br /><br />"Our results indicate that, relative to night sleep, reduced melatonin production among shift workers during night work is associated with significantly reduced urinary excretion of 8-OH-dG," researchers including Parveen Bhatti from Fred Hutchinson Cancer Research Centre in the US said.<br /><br />A particular pathway called NER is thought to be involved in the repair of DNA damage caused by oxygen free radicals, which are produced during normal cellular activity, researchers said.<br /><br />Research has shown that melatonin production boosts the activity of the genes involved in the NER pathway, they said.<br /><br />The study was published in the British Medical Journal.</div>