Tuesday, December 23, 2008

South Indians have their paternal lineage in Europe, maternal genes in East Asia

December 24, 2008
By Syed Akbar
Hyderabad, Dec 23: The paternal lineage of South Indians is traceable to Europe while their maternal genes point to East Asia.
A joint study by a group of international research organisations on the caste populations in Tamil Nadu and Andhra Pradesh has revealed that South Indian paternal lineages have been more substantially influenced by western or central Eurasians compared to South Indian maternal lineages.
The study was conducted by the Department of Human Genetics, University of Utah, USA, Schizophrenia Research Foundation, India, Queensland Centre for Mental Health Research, Australia, and University of Washington School of Medicine, USA. The researchers suggested an affinity between Dravidian populations from South India
and populations in the north and west.
The research team led by senior scientist Dr LB Jorde studied Y-chromosomes (for paternal lineage) and found that Tamil castes showed higher affinity to Europeans than to eastern Asians, and that genetic distance estimates to the Europeans are ordered by caste rank.
And when the team studied the mitochondrial DNA (maternal lineage), it found that Tamil castes have higher affinity to eastern Asians than to Europeans. Same was the case with caste populations in Andhra Pradesh.
Certain South Asian lineages are common in Tamil and Andhra castes. One of the South Asian lineages, U7, is the most prevalent "U" lineage in both the groups. Interestingly, U7 is also common in Iran, Pakistan, and northern India. "This suggests an affinity between Dravidian populations from South India and populations to the north and west," Dr Jorde said.
Although other interpretations may be possible, Dr Jorde said their data from the research study is "consistent with a model in which nomadic populations from northwest and central Eurasia intercalated over millennia into an already complex, genetically diverse set of subcontinental populations."
As these populations grew, mixed, and expanded, a system of social stratification likely developed in situ, spreading to the Indo-Gangetic plain, and then southward over the Deccan plateau. The predominantly south and east Asian mtDNA (maternal) haplogroup M is found in more than half of individuals from a wide sampling of castes and is nearly fixed in some AustroAsiatic tribal populations. This maternal
haplogroup is uncommon in western European populations.
In contrast, some paternally-inherited Y-chromosome lineages are more closely related to lineages originating in central Asians and Europeans.Genetic distances estimated from autosomal polymorphisms have typically demonstrated that caste populations tend to occupy a position intermediate between European and East Asian populations.
"The genetic affinities among the more than 2000 extant caste populations of India, however, are complex. Genetic distances between caste populations from Andhra Pradesh are correlated with differences in caste rank, suggesting that endogamy and differential inter-caste gene flow influences genetic structure," the study noted.
The study reveals that in Tamil Nadu, genetic distances between castes are positively correlated with caste rank. A similar pattern was detected in upper, middle, and lower rank castes of Andhra Pradesh.

Monday, December 22, 2008

Musi pollution: Hookworm threat due to use of sewage in agriculture

December 22, 2008
By Syed Akbar
Hyderabad, Dec 21: Hyderabadis, who consume fruits and vegetables grown over 3,600 hectares under Musi ayacut, run the risk of severe worm infection that may cause appetite loss, abdominal pain, shortness of breath and a variety of skin diseases.
According to a joint study by the London School of Hygiene and Tropical Medicine and the International Water Management Institute, Hyderabad, farmers as well as consumers are hit by use of sewage or wastewater in agriculture in and around Hyderabad. As unpolluted water is not available in sufficient quantities in the State capital region for agriculture, scores of farmers in the downstream of Musi are increasingly going in for untreated water for their crops and orchards,
exposing their health as well as of consumers.
If the WHO standards are to be followed, wastewater used in Hyderabad to irrigate is unfit for crop production.
"Intestinal nematode infections have been identified as the main health risk associated with this practice. To protect consumer and farmer health, the World Health Organisation has established an intestinal nematode water quality standard... The use of wastewater poses a number of health risks. Predominant among these is the risk of intestinal helminth infection," Jeroen H J Ensink of London School of
Hygiene and Tropical Medicine, told this correspondent.
The study found that in Hyderabad around 250 households use wastewater from the Musi river to irrigate 500 hectares of land. Downstream of Hyderabad, farmers, with the help of weirs, irrigate 3,100 hectares of agricultural land.
For the purpose of the study, the research team divided the city and its suburbs into three zones, centre of Hyderabad (high concentration of hookworm eggs), peri-urban zone of Hyderabad (medium concentration of hookworm infection) and villages downstream of the river Musi.
The team found prevalence of hookworm and heavy hookworm infection and other intestinal parasites like Ascaris (giant round worms) and Trichuris (whip worms). Overall, 31.2 per cent of persons, who formed part of the study, were infected by at least one intestinal nematode infection. Of these, hookworm is the most prevalent (29.8 per cent), followed by Ascaris lumbricoides and Trichuris trichiura.
The mean intensity of infection ranged from 35 eggs per gram of faeces (epg) for hookworm to 1.7 epg for T. trichiura. The highest intensity of infection in a person was found for hookworm (1,789 epg), followed by A. lumbricoides (1,333 epg) and T. trichiura (336 epg).He said a significant difference in the prevalence of hookworm, Ascaris and Trichuris was found among the three city zones. Farming families
in centre of Hyderabad had a significantly higher prevalence of hookworm, Ascaris and Trichuris infection. In addition, they also exhibited a significantly higher intensity of infection for all three infections relative to farming families in other two zones.
"Among all persons, use of untreated wastewater, when controlled for confounding variables, was associated with an almost four-fold increased risk of hookworm and heavy hookworm infection. This result was in contrast to the use of partially treated wastewater, which showed no significant association with hookworm infection when controlled for confounding variables. Use of untreated wastewater further showed a greater than five-fold increased risk of Ascaris and Trichuris infection.
Use of partially treated wastewater was associated with a greater than three-fold increased risk of Ascaris infection," Jeroen Ensink said.
The highest risks were associated with use of untreated wastewater, and use of partially treated wastewater was associated only with an increased risk of Ascaris. Use of untreated wastewater was also associated with a higher intensity of infection, especially for hookworm infection.

Thursday, December 11, 2008

Metals in Ayurveda: Scientific evaluation and standardisation of herbal drugs

November 23, 2008
By Syed Akbar
Hyderabad, Nov 22: With the USA and European nations rejecting Ayurvedic drugs containing metals, the Central government has now embarked on a mega scientific mission to prove that metallic compounds in traditional Indian system of medicine are indeed helpful in fighting diseases.
Only Ayurveda system of medicine extensively utilises a variety of metals to treat certain health problems and boost immunity to fight diseases. But since there's no scientific evaluation of these drugs, developed nations have put a ban on them.
The Department of Science and Technology has entrusted the research, evaluation and standardisation work of Ayurvedic drugs containing metallic compounds to a number of scientific, research and pharma bodies across the country, including the city-based Indian Institute of Chemical Technology.
Ayurvedic medicines consist of ingredients of herbal, mineral, metallic and animal origin. While scientists in many countries are working on herbal products, no country is working on metallic products, which is an important strength area of Ayurveda. This is because, barring India, this knowledge does not exist anywhere else.
"Arsenic and mercury may be harmful. But when taken in minute quantities they have several health benefits. Ayurvedic drugs have been using these and other metals for centuries. What we need to prove is that these metallic compounds are beneficial to health in small quantities. We have taken up the evaluation and standardisation work.
Once our task is complete Ayurvedic drugs will get scientific backing," Dr J Madhusudhan Rao, director-grade scientist, IICT, told this correspondent. The DST believes that it is one area where India can make original contribution to the world and thus there's need for validation of claim of metallic products. "It is our heritage and needs to be subjected through well planned research in order to bring it to international fora as India’s unique contribution," he added.
The task before the scientific team is to identify different types of bhasmas and formulations for carrying out scientific studies with regard to the standardisation of raw materials, processes and finished products. It also involves chemical transformation, safety, efficacy evaluation, and validation through networking of the various institutions and industries having expertise in this area.
Ayurvedic drugs containing metals will be subjected to pre-clinical studies in animal models for pharmacological evaluation and toxicity,pharmacodynamic and tissue distribution studies. Later, the drugs will be used on human beings for clinical studies, though thousands of Indians have already been using them for centuries.
"It is essential to understand the chemical nature of the complexation taking place with metallic ions and organic phyto-constituents present in medicinal plants with which the metals are treated. Unless we understand the nature of the complex compounds formed during the processing of metals/minerals and medicinal plant material, it is not possible to evolve the quality parameters and understand the
mechanism of action of such important, potent and unique drugs of Ayurveda and Siddha," DST guidelines on Ayurveda research point out.