Low prevalence of latent autoimmune diabetes in adults in northern India

AIM

To study the frequency of islet antibodies in a large cohort of clinic- and community-based patients with Type 2 diabetes in northern India.

METHODS

We measured glutamic acid decarboxylase (GAD) antibodies in 618 adults with Type 2 diabetes (378 patients with diabetes attending a hospital clinic, 240 patients diagnosed in a community survey) and in 192 healthy subjects residing in north India. Islet antigen 2 (IA2) antibodies were also studied in a proportion of the patients with diabetes (n = 492) and in a control population (n = 191). GAD and IA2 antibodies were measured by immunoprecipitation of the respective (35) S-labelled recombinant antigen.

RESULTS

We found that GAD antibodies were present in nine (1.5%) patients with diabetes (clinic population: 0.8%, community study: 2.5%), a prevalence similar to that among the subjects without diabetes (n = 2; 1%). IA2 antibodies were detected in seven patients with Type 2 diabetes (1.4%) and in two healthy control subjects (1.0%). The frequency of either GAD or IA2 antibodies was similar in people with and without diabetes (3.2 vs 2.1%). No subject was found to have both antibodies. Insulin requirement was higher among antibody-positive than among antibody-negative patients (GAD antibody: 33 vs 6.3%; P = 0.001; GAD or IA2 antibody: 23.1 vs 6.4%; P = 0.02); however, other clinical features were similar in the two groups.

CONCLUSIONS

In the present north-Indian population with Type 2 diabetes, the overall prevalence of GAD antibodies and the prevalence of either GAD or IA2 antibodies were considerably lower than those reported in white European populations.

Vitamin B12 levels are not affected by radioiodine ablation of the thyroid

OBJECTIVE

Radioiodine administered for the treatment of hyperthyroidism and thyroid cancer can be taken up by many non-thyroid tissues which express sodium iodide symporter. Though gastric mucosa takes up radioiodine, its impact on parietal cell has not been evaluated. The aim of the present study was to compare vitamin B12 and homocysteine concentrations in patients with thyroid disorders treated by radioiodine ablation with those in control population without radioiodine exposure.

METHODS

Patients with Graves' disease, toxic multinodular goiter (TMNG), toxic adenoma (TA) or differentiated thyroid cancer (DTC) who had received 131I were included as "patients". Healthy persons and patients having Graves' disease but without exposure to radioiodine were recruited as "controls". A total of 35 patients and 35 controls were included. Patients were divided into Graves' disease and non-Graves' disease (TMNG, TA, DTC) groups. Graves' disease patients were compared with Graves' disease controls while non-Graves' disease patients were compared with healthy controls.

RESULTS

In the Graves' disease group, median vitamin B12 concentration was 240 pg/ml (IQR: 148 - 371) in patients (n=23) and 195 pg/ml (IQR: 140 - 291 pg/ml) (p=0.13, ns) in controls (n=24). In the non-Graves' disease group, median serum vitamin B12 concentration was 147 pg/ml (IQR: 124 - 325pg/ml) in patients (n=12) and 190 pg/ml (IQR: 157 - 373 pg/ml) (p=0.34, ns) in healthy controls (n=11). Homocysteine concentrations were also similar in compared groups of patients and controls.

CONCLUSIONS

Radioiodine ablation does not cause vitamin B12 deficiency. However, a prospective study with a larger number of patients is required to confirm this finding.

Antioxidant defense in overt and subclinical hypothyroidism

Oxidative stress as a result of disequilibrium between free radical generation and antioxidant status has been implicated in several pathologies including thyroid diseases. Studies on antioxidant status in overt (OHT) and subclinical hypothyroidism (SHT) are controversial and limited. The aim of this study was to determine the effect of OHT and SHT on antioxidant status. Thirty-six patients with OHT, 36 patients with SHT, and 39 healthy euthyroid subjects as the control group were included in the study. Plasma levels of malondialdehyde (MDA), reduced glutathione (GSH) and total antioxidant capacity (TAC) as ferric reducing ability of plasma (FRAP), and erythrocyte antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx), SOD/GPx ratios, catalase (CAT), and glutathione reductase (GR) were analyzed in all groups. MDA and GPx values were elevated, while GSH, FRAP, SOD, and SOD/GPx ratio were decreased in both patient groups compared with controls. No change in activities of CAT and GR were observed in both the patient groups. Significant differences were observed between OHT and SHT groups with high MDA, GPX and low GSH, FRAP, SOD, and SOD/GPx ratio in OHT group. Thus, hypothyroid patients have a deficient antioxidant defense in the form of decreased activity of SOD, decreased levels of FRAP and GSH along with an increase in GPx activity. The severity of the disease appears to decide the degree of deficiency and our findings also point to this, in the form of decrease in SOD, FRAP, and GSH observed being more in OHT than in SHT patients. Hormonal changes and increased lipid peroxidation, which also vary with severity of disease, appear to contribute to the antioxidant deficiency.

Association of lipid peroxidation with endothelial dysfunction in patients with overt hypothyroidism

Hypothyroidism is associated with increased oxidative stress. The mechanism underlying the endothelial dysfunction in thyroid disease is not yet clear. This study aims to investigate lipid peroxidation and its association with endothelial dysfunction in overt hypothyroidism (OHT).Plasma malondialdehyde (MDA) as a marker of oxidative stress and plasma nitrates and asymmetric dimethyl arginine levels (ADMA) as markers of endothelial dysfunction were estimated in 25 OHT patients in comparison to 25 euthyroid controls. Plasma MDA, ADMA levels were significantly increased, whereas plasma nitrates were significantly decreased in the patient group compared to control group (p<0.01). Moreover, a significant positive association between plasma MDA and ADMA was found in the patient group (ρ=0.472, p=0.036). Our results reveal the presence of endothelial dysfunction in OHT patients as evidenced by decreased plasma nitrates and increased ADMA levels. Increased levels of MDA represent an increased generation of reactive oxygen species in these patients. A finding of significant direct relation of plasma MDA with ADMA indicates that oxidative stress has a strong impact on endothelial dysfunction in overt hypothyroidism. Further studies focusing on the role of oxidative stress in endothelial dysfunction and the effects of antioxidant supplementation on endothelial function in OHT patients are required.

Risk and outcome of multidrug-resistant tuberculosis: vitamin D receptor polymorphisms and serum 25(OH)D

SETTING

All India Institute of Medical Sciences and Rajan Babu Institute of Pulmonary Medicine and Tuberculosis, New Delhi, India.

OBJECTIVE

To investigate the association of vitamin D receptor (VDR) polymorphisms and serum 25(OH)D with susceptibility to, and response to treatment of, multidrug-resistant tuberculosis (MDR-TB) in comparison with drug-susceptible pulmonary TB (DS-PTB) and healthy controls.

DESIGN

Cross-sectional study.

METHODS

A total of 897 participants from northern India were consecutively enrolled into three groups (MDR-TB 354, DS-PTB 338, controls 205). Genotypic and allelic frequencies of FokI, BsmI and TaqI VDR polymorphisms, and serum 25(OH)D, calcium and intact parathyroid hormone were measured in all participants. In those with active TB, disease severity, time to sputum smear and culture conversion were correlated with VDR genotype and biochemical parameters.

RESULTS

FokI Ff genotype and TaqI t allele correlated positively with MDR-TB; Ff genotype and f allele of FokI frequency were higher in both TB groups. BsmI Bb genotype correlated inversely with MDR-TB. Serum 25(OH)D concentrations were significantly lowest in MDR-TB, correlating inversely with time to sputum smear conversion.

CONCLUSIONS

VDR gene polymorphisms and hypovitaminosis D may predispose to MDR-TB. Lower serum 25(OH)D may increase time to MDR-TB sputum smear negativity.

Swyer Syndrome : A Case Report with Literature Review

Gonadoblastomas are known to develop in dysgenetic gonads, especially so, if Y chromosome material is present. A 20-years- old girl who noticed breast development since the age of 12 years presented with primary amenorhoea, distension of lower abdomen and intermittent pain for two months. She had breakthrough bleeding with six months of estrogen replacement. Tanner breast stage was fi ve and pubic hair stage was also fi ve. Examination revealed a mass in the lower abdomen extending into hypogastrium, umbilical and lumbar regions. Her gonadotropin levels were grossly elevated. Karyotyping showed 46XY. CT scan of abdomen showed a 17X11 cm mass in the pelvis without visible gonads. Surgical excision of the mass along with bilateral salpingophorectomy was performed. Histopathology revealed the mass to be a dysgerminoma, while the right gonad lodged gonadoblastoma. She was diagnosed as a rare case of Swyer syndrome. Keywords: Dysgerminoma, gonadoblastoma, Swyer syndrome, XY gonadal dysgenesis.

Swyer syndrome: a case report with literature review

Gonadoblastomas are known to develop in dysgenetic gonads, especially so, if Y chromosome material is present. A 20-years-old girl who noticed breast development since the age of 12 years presented with primary amenorhoea, distension of lower abdomen and intermittent pain for two months. She had breakthrough bleeding with six months of estrogen replacement. Tanner breast stage was five and pubic hair stage was also five. Examination revealed a mass in the lower abdomen extending into hypogastrium, umbilical and lumbar regions. Her gonadotropin levels were grossly elevated. Karyotyping showed 46XY. CT scan of abdomen showed a 17X11 cm mass in the pelvis without visible gonads. Surgical excision of the mass along with bilateral salpingophorectomy was performed. Histopathology revealed the mass to be a dysgerminoma, while the right gonad lodged gonadoblastoma. She was diagnosed as a rare case of Swyer syndrome.

Biotransformation of p-coumaric acid by Paecilomyces variotii

AIMS

To investigate the biotransformation of p-coumaric acid into p-hydroxybenzoic acid (p-HBA) by Paecilomyces variotii Bainier MTCC 6581.

METHODS AND RESULTS

As a result of p-coumaric acid degradation by P. variotii, three phenolic metabolites, p-hydroxybenzaldehyde (p-HBAld), p-HBA and protocatechuic acid were formed. These phenolics were detected using TLC and HPLC. The identity of p-HBA and p-HBAld was further confirmed by mass spectrometry. Various analyses showed that 10.0 mmol l(-1) concentration of p-coumaric acid produced a maximum amount of p-hydroxybenzoic acid, 200 mg l(-1), into the medium at 37 degrees C with high-density cultures.

CONCLUSIONS

A catabolic pathway of p-coumaric acid by the fungus P. variotii is suggested for the first time. During the process of p-coumaric acid degradation, p-HBA accumulated in the medium as the major degradation product.

SIGNIFICANCE AND IMPACT OF THE STUDY

Microbial degradation of cinnamic acid and hydroxycinnamic acid has continued to be the focus of intensive study. The main goal was to identify the microbial species capable of converting these substances into commercially value-added products such as benzoic acid derivatives or aromatic aldehydes.