Epigenetics and epigenetic mechanisms in disease with emphasis on autoimmune diseases.

Epigenetics deals with molecular heritable patterns relating to chromatin, which exists in two alterable and inter-convertible states. The two conformations of chromatin i.e., compact and relaxed are due to epigenetic regulation. The alterations in chromatin normalize gene expression patterns. Thus, the epigenetic marks on chromatin are the deciding factors for either gene silencing or activation. The epigenetics introduced a new term viz., epiallele which deviates from the classical Mendelian allele. The remodeling of chromatin during embryonic phase, post-translational aberrations of chromatin proteins causing cellular dysfunction and possible epigenetic therapies are discussed in the present article. The role of epigenetic mechanisms in triggering / progression of several autoimmune diseases is being emphasized off late. The study of such complex epigenetic processes becomes very important in understanding the etiopathology of the disease as well as in designing target therapies.

Copper & biological health.

Cu being a transition metal is ubiquitously engaged in biological systems to derive electrons through its participation in several enzymatic reactions. Upon bestowing the significance of Cu in biological systems, an elaborate mechanism is set forth by nature for maintaining Cu homeostasis. As a consequence, a wide variety of proteins viz., family of Cu bearing proteins, cuproenzymes, Cu transporters and Cu chaperone proteins have been manifested for enabling Cu to show its relevance in biological health. In addition, understanding the role of Cu in hepatic and neuronal functions and also in angiogenesis keeps progressing with the advent of novel molecular tools. The studies on genetic defects in Cu metabolism causing abnormalities are providing insights leading to the possible prognostic cues to alleviate the sufferings.

Gestational diabetes mellitus in India.

BACKGROUND: Glucose intolerance during pregnancy predisposes the offspring for increased risk of developing glucose intolerance in the future. This vicious cycle is likely to influence and perpetuate the incidence and prevalence of glucose intolerance in any population. AIM: No data is available about the prevalence of glucose intolerance during pregnancy in our country and hence a study was undertaken on this aspect. METHODS: This study was performed in the antenatal clinic of Government Maternity Hospital, Chennai, India. As a pregnant woman in second or third trimester checks into the antenatal clinic, she was given 50 gm oral glucose load and blood sample was collected after one hour. This test was performed on 1251 pregnant women. They were requested to come after 72 hours for the 75 gm OGTT recommended by WHO. Among the 1251 women, 891 responded. The blood sample was taken in the fasting state and at 2 hours after 75 gm of oral glucose. Diagnosis was based on the WHO criteria for gestational diabetes mellitus (GDM). RESULTS: The mean age of these pregnant women was 23+/-4 years. There was a significant increase in the prevalence of GDM in relation to gravida. The effect of BMI did not quite reach statistical significance (chi2 (df=1) = 3.659, P = 0.055), but a model of linear trend was significant. Of the 1251 women who underwent the 50 gm oral glucose challenge test, 670 (53.55%) had one hour plasma glucose > or = 130 mg/dl. Among the 891 pregnant women who had 75 gms OGTT, 168 (18.9%) were diagnosed as GDM, taking both FPG > or = 126 mg/dl and/or 2 hr PPG > or = 140 mg/dl as cut-off values. Taking only 2 hr plasma glucose for analysis, 144 (16.2%) had a value > or = 140 mg/dl. A similar study was conducted in different parts of the country taking only the 2 hr 75 gm post-glucose value of > or = 140 mg/dl as diagnostic criteria for GDM. Of the total number of pregnant women (n = 3674) screened, 16.55% of them found to have GDM. CONCLUSION: Our study has documented the increased prevalence of GDM in our population necessitating universal screening for glucose intolerance in pregnancy. Using 2 hr plasma glucose > or = 140 mg/dl as a one step procedure is simple and economical, particularly for the countries ethnically more prone to high prevalence of diabetes.

Antifilarial and anti PPD IgM antibodies in cord blood.

Tuberculosis and Filariasis are commonly encountered in South India, more so in the low socio-economic group. This study was undertaken to find out the fetal immune response to maternal filariasis and tuberculosis. The presence of anti-filarial and anti-PPD IgG and IgM antibodies in the mother and cord blood at the time of delivery was identified by ELISA. Six out of 29 cases showed IgM against Brugia malayi antigen in the cord blood. In both instances, 6 out of 29 for PPD and 7 out of 29 for B. malayi, the maternal blood too showed the presence of IgM to these two antigens. Comparison with anti-Ascaris lumbricoides IgM antibodies in mother and cord blood in these (6 out of 29 against PPD and 7 out of 29 against B. malayi) cases did not show a similar distribution of IgM antibodies in mother and cord blood, indicating that there is a fetal response to maternal filariasis and tuberculosis.