ICMR releases draft ethical guidelines
The Indian Council of Medical Research (ICMR) has issued draft ethical guidelines on biomedical research. The guidelines have been drawn up by an expert panel chaired by Justice M. N. Venkatachalaiah, former Chief Justice of the Supreme Court and currently chairperson of the National Human Rights Commission, and updates the earlier set of guidelines released in 1980. Of great significance are the proposed regulations in controversial areas such as genetic testing, assisted reproduction and organ transplantation.
As per the these guidelines screening for genetic disorders would be justified in circumstances that involve public safety. Airlines, for instance, can screen pilots for sickle-cell anaemia, since this condition may affect the individual's judgement and actions in atypical atmospheric conditions. Genetic screening in employment may be organised with the consent of employees. However, life and medical insurance companies cannot make genetic tests a prerequisite for taking out policies. Family members are not automatically entitled to know the results of one another's genetic tests. Prenatal diagnosis is permitted if relevant to the well-being of the mother and the foetus but not for sex determination. All human genetic research in India must adhere to guidelines laid down by the Indian government, including international collaborations. DNA samples cannot leave the country without conforming to established regulations.
Research on human embryos upto 14 days old has been allowed. So has been the creation of ‘abnormal' embryos using eggs and sperms obtained from high-risk parents to study the transmission of genetic disorders. But the transfer of any manipulated embryo to human uterus and the commercial exploitation of embryo research is to be prohibited. Foetuses from pregnancies terminated on medical grounds may be used for organ transplantation in patients for whom no alternative therapy is available or applicable. But animal-to-human transplantation is not permissible in general.
The proposed guidelines are long-awaited and are likely to have far-reaching impact. It merits careful scrutiny by all concerned researchers and individuals.
Source: Jayaraman KS. Indian guidelines allow limited genetic screening. Nature 1998; Jan 8.

New treatment for caries to make the dentist's drill all but obsolete ?
Dental caries is the process of tooth decay. It has no dramatic or easily identified starting point, nor end-point, unless the latter be regarded as an acute pulpitis resulting in tooth extraction. The process is highly dynamic, with periods of progression alternating with periods of arrest or even partial repair of damaged tissue. Periods of disease activity vary widely in their duration and intensity between different population groups, between different individuals and even in single patients at different ages or different hours of the day. In the same mouth, individual teeth may vary greatly in their susceptibility. The initiation of carious lesion on a given tooth surface, be it enamel of the tooth crown or the cementum of the exposed root, is customarily attributed to acids produced by dental plaque bacterial metabolism, that cause subsurface demineralisation of tooth tissue. Progression, arrest or repair depends on the balance between relevant physicochemical factors such as the solubility of tooth mineral, pH of the microenvironment, permeability and ionic concentration at the tooth surface. Whatever the background phenomena, dentists try to arrest further tooth decay by removing the diseased dental tissue and replacing it by inert filling material. To remove the diseased tissue they make use of their trademark instrument — the drill.
Researchers of a Swedish company, Medi-team of Gothenberg, have reported the development of a new preparation to fight tooth decay that makes dentists much less dependent on their drill. It comes in 2 vials, one containing three amino acids, and the other a weak solution of sodium hypochlorite. These are mixed together and a few drops applied to the decayed tooth. It is claimed that the mixture dissolves the decayed dentine and diseased tooth tissue in 30 seconds, allowing the dentist to scrape the cavity and clean it out with warm water and cotton wool before filling it. Some drilling may still be needed for cavities with limited access such as those underneath fillings, but even in these cases, the drill will usually only be used to remove tissue in the least sensitive areas, far from nerves. The hypochlorite is the chemical that actually dissolves the decayed tooth while the amino acids act as buffer to check damage to healthy tissue.
Cost, needles and fear of the drill are among the prime reasons why people avoid going to their dentist. If this new preparation can relegate the drill to the sidelines it would be a significant development indeed.
Source: The Statesman 1998, Jan 9.

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