Electrochemical immunosensor for label free epidermal growth factor receptor (EGFR) detection

This paper presents an electrochemical immune sensor for label free detection of epidermal growth factor receptor (EGFR) by immobilizing anti-EGFR antibody (Anti-EGFRab) on dithiobissuccinimidyl propionate (DTSP) self-assembled monolayer (SAM) on gold (Au) electrode. Electrochemical studies show that increased surface concentration of redox moieties onto Anti-EGFRab/DTSP immuno-electrode leads to high electron transport and improved sensing performance. The antigen-antibody complex demonstrates a high association constant (5×10(12)L/mol) that results in high affinity of Anti-EGFRab to EGFR, confirming that the DTSP-SAM provides a conducive environment for anti-EGFR immobilization. The electrochemical response of EA/Anti-EGFRab/DTSP/Au electrode as a function of EGFR concentrations exhibits a linear range from 1pg/mL to 100ng/mL, a detection limit of 1pg/mL at a sensitivity of 2.02μAM(-1)at a regression coefficient of 0.99.     

Ultrasensitive detection of cortisol with enzyme fragment complementation technology using functionalized nanowire

Cortisol is a member of the glucocorticoid hormone family and a key metabolic regulator. Increased intracellular cortisol levels have been implicated in type 2 diabetes, obesity, and metabolic syndrome. Cortisol is an important bio-marker of stress and its detection is also important in sports medicine. However, rapid methods for sensitive detection of cortisol are limited. Functionalized gold nanowires were used to enhance the sensitivity and selectivity of cortisol detection. Gold nanowires are used to improve the electron transfer between the electrodes. Moreover, the large surface to volume ratio, small diffusion time and high electrical conductivity and their aligned nature will enhance the sensitivity and detection limit of the biosensor several fold. The biosensor was fabricated using, aligned gold (Au) nanowires to behave as the working electrode, platinum deposited on a silicon chip to function as the counter electrode, and silver/silver chloride as reference electrode. The gold nanowires were coupled with cortisol antibodies using covalent linkage chemistry and a fixed amount of 3alpha-hydroxysteroid dehydrogenase was introduced into the reaction cell during each measurement to convert (reduce) ketosteroid into hydroxyl steroid. Furthermore, the micro-fluidic, micro-fluid part of the sensor was fabricated using micro-electro-mechanical system (MEMS) technology to have better control on liquid flow over Au nanowires to minimize the signal to noise ratio. The biosensor was characterized using SEM, AFM and FTIR technique. The response curve of the biosensor was found to be linear in the range of 10-80 microM of cortisol. Moreover, the presence of hydrocortisone is sensitively detected in the range of 5-30 microM. It is concluded that the functionalized gold nanowires with micro-fluidic device using enzyme fragment complementation technology can provide an easy and sensitive assay for cortisol detection in serum and other biological fluids.     

Low serum PON1 activity: an independent risk factor for coronary artery disease in North-West Indian type 2 diabetics

Posttranslational modifications of proteins have profound effects on many aspects of their function and have received much attention due to the importance of these processes in epigenetic regulation. In this study, we report that deleted azoospermia associated protein 1 (DAZAP1)/proline-rich RNA binding protein (Prrp), a multifunctional RNA binding protein which is essential for spermatogenesis and normal cell growth, is acetylated at Lysine 150 within its RNA binding domain. The acetylation is predominantly observed in nuclear Prrp, and the nonacetylated form is in cytoplasm. Considering that Prrp is a shuttling protein, we suggest that the acetylation cycle at Prrp K150 regulates nucleocytoplasmic transport in cells.     

Association of educational, occupational and socioeconomic status with cardiovascular risk factors in asian indians: a cross-sectional study

Background

To determine correlation of multiple parameters of socioeconomic status with cardiovascular risk factors in India.

Methods

The study was performed at eleven cities using cluster sampling. Subjects (n = 6198, men 3426, women 2772) were evaluated for socioeconomic, demographic, biophysical and biochemical factors. They were classified into low, medium and high socioeconomic groups based on educational level (<10, 10–15 and >15 yr formal education), occupational class and socioeconomic scale. Risk factor differences were evaluated using multivariate logistic regression.

Results

Age-adjusted prevalence (%) of risk factors in men and women was overweight or obesity in 41.1 and 45.2, obesity 8.3 and 15.8, high waist circumference 35.7 and 57.5, high waist-hip ratio 69.0 and 83.8, hypertension 32.5 and 30.4, hypercholesterolemia 24.8 and 25.3, low HDL cholesterol 34.1 and 35.1, high triglycerides 41.2 and 31.5, diabetes 16.7 and 14.4 and metabolic syndrome in 32.2 and 40.4 percent. Lifestyle factors were smoking 12.0 and 0.5, other tobacco use 12.7 and 6.3, high fat intake 51.2 and 48.2, low fruits/vegetables intake 25.3 and 28.9, and physical inactivity in 38.8 and 46.1%. Prevalence of > = 3 risk factors was significantly greater in low (28.0%) vs. middle (23.9%) or high (22.1%) educational groups (p<0.01). In low vs. high educational groups there was greater prevalence of high waist-hip ratio (odds ratio 2.18, confidence interval 1.65–2.71), low HDL cholesterol (1.51, 1.27–1.80), hypertriglyceridemia (1.16, 0.99–1.37), smoking/tobacco use (3.27, 2.66–4.01), and low physical activity (1.15, 0.97–1.37); and lower prevalence of high fat diet (0.47, 0.38–0.57),overweight/obesity (0.68, 0.58–0.80) and hypercholesterolemia (0.79, 0.66–0.94). Similar associations were observed with occupational and socioeconomic status.

Conclusions

Low educational, occupational and socioeconomic status Asian Indians have greater prevalence of truncal obesity, low HDL cholesterol, hypertriglyceridemia, smoking or tobacco use and low physical activity and clustering of > = 3 major cardiovascular risk factors.     

Dopaminergic influence on thyrotropin secretion in primary hypothyroidism.

This study was conducted to assess the influence of dopamine on thyrotropin secretion in patients with primary hypothyroidism before and after optimized L-thyroxin replacement therapy. Thyrotropin responses to dopamine infusion (4 microg/kg/min over 3 hours) and IV metoclopramide (10 mg bolus), a dopamine receptor blocker were studied in 25 consecutive patients with primary hypothyroidism before and after achieving stable euthyroid state and compared with 15 normal age-matched controls. Thyrotropin response to both dopamine infusion (decremental) and IV metoclopramide bolus (incremental) was greater in patients with primary hypothyroidism than that in the control subjects. Thyrotropin response was greater in women than in men. The magnitude of decremental thyrotropin response to dopamine infusion and the incremental response to IV metoclopramide bolus significantly correlated with the basal T3 and T4 levels. Thyrotropin response was blunted to dopamine infusion but not to metoclopramide at follow-up after six-month replacement with L-thyroxin, and both the responses were comparable in women and men in patient group. We conclude that modulation of dopaminergic system by dopamine or by dopamine receptor blocker has a greater influence on thyrotropin secretion in patients with primary hypothyroidism than euthyroid normal subjects.     

Serum paraoxonase-1 (PON1) activities (PONase/AREase) and polymorphisms in patients with type 2 diabetes mellitus in a North-West Indian population

Objective

Paraoxonase-1 (PON1), an HDL-C associated enzyme, protects lipoproteins from oxidation. There is evidence that PON1 enzyme activity is reduced in the patients with type 2 diabetes mellitus (T2DM). North-West Indian Punjabis, a distinct ethnic group has high incidence of T2DM. However till date there is no information regarding PON1 enzyme activities and PON1 polymorphisms in T2DM patients of this ethnic group.

Methods

We identified polymorphisms in the coding Q192R, L55M and promoter − 909G/C, − 162A/G, − 108C/T of the PON1 gene by using PCR-RFLP, multiplex PCR and allele specific oligonucleotide PCR assays in 250 T2DM patients and 300 healthy controls. We also assessed paraoxonase (PONase) and arylesterase (AREase) activities of PON1 enzyme.

Results

The serum PONase (114.2 vs. 178.0 nmol/min/ml) and AREase (62.7 vs. 82.5 μmol/min/ml) activities were significantly lower (p < 0.0001) in patients as compared to controls. PONase activity was affected by all the studied PON1 polymorphisms. However, AREase activity was not affected by any of these polymorphisms. Coding Q192R and promoter − 909G/C polymorphisms showed significant differences in genotypic distribution. QR, RR (Q192R) and GC, CC (− 909G/C) genotypes and L-C-A-R-G, L-T-A-R-G, L-T-G-Q-C haplotypes showed significant association with type 2 diabetes. No significant linkage disequilibrium was observed among the five polymorphisms.

Conclusion

Both PONase and AREase activities are lower in patients and this could lead to increased lipid peroxidation and accelerated atherosclerosis in them. PONase activity, but not AREase activity is influenced by PON1 polymorphisms. QR, RR, GC, CC genotypes and L-C-A-R-G, L-T-A-R-G, L-T-G-Q-C haplotypes are commoner in diabetics as compared to controls and may be related to genetic susceptibility to type 2 diabetes.     

Prevalence of Dyslipidemia in Urban and Rural India: The ICMR–INDIAB Study

Aim

To study the pattern and prevalence of dyslipidemia in a large representative sample of four selected regions in India.

Methods

Phase I of the Indian Council of Medical Research–India Diabetes (ICMR-INDIAB) study was conducted in a representative population of three states of India [Tamil Nadu, Maharashtra and Jharkhand] and one Union Territory [Chandigarh], and covered a population of 213 million people using stratified multistage sampling design to recruit individuals ≥20 years of age. All the study subjects (n = 16,607) underwent anthropometric measurements and oral glucose tolerance tests were done using capillary blood (except in self-reported diabetes). In addition, in every 5th subject (n = 2042), a fasting venous sample was collected and assayed for lipids. Dyslipidemia was diagnosed using National Cholesterol Education Programme (NCEP) guidelines.

Results

Of the subjects studied, 13.9% had hypercholesterolemia, 29.5% had hypertriglyceridemia, 72.3% had low HDL-C, 11.8% had high LDL-C levels and 79% had abnormalities in one of the lipid parameters. Regional disparity exists with the highest rates of hypercholesterolemia observed in Tamilnadu (18.3%), highest rates of hypertriglyceridemia in Chandigarh (38.6%), highest rates of low HDL-C in Jharkhand (76.8%) and highest rates of high LDL-C in Tamilnadu (15.8%). Except for low HDL-C and in the state of Maharashtra, in all other states, urban residents had the highest prevalence of lipid abnormalities compared to rural residents. Low HDL-C was the most common lipid abnormality (72.3%) in all the four regions studied; in 44.9% of subjects, it was present as an isolated abnormality. Common significant risk factors for dyslipidemia included obesity, diabetes, and dysglycemia.

Conclusion

The prevalence of dyslipidemia is very high in India, which calls for urgent lifestyle intervention strategies to prevent and manage this important cardiovascular risk factor.     

Metformin upregulates mitophagy in patients with T2DM: A randomized placebo-controlled study

Impaired mitochondrial autophagy (mitophagy) and NLRP3 inflammasome activation have been incriminated in the pathogenesis of T2DM. Metformin besides being an insulin sensitizer also induces autophagy; however, its effect on mitophagy and NLRP3 activation in patients with T2DM still remains elusive. Forty-five drug-naïve T2DM patients with HbA_1C 7%-9% (53-75 mmol/mol) were randomly assigned to receive either metformin, voglibose, or placebo for 3 months, and were also recommended for lifestyle intervention programme (n = 15 each). Mitochondrial oxidative stress (MOS) parameters, qPCR and immunoblotting of mitophagy-related markers (PINK1, PARKIN, MFN2, NIX, LC3-II, LAMP2), p-AMPKα (T172), and NLRP3 proteins, as well as transmission electron microscopy (TEM) for assessing mitochondrial morphology were performed in the mononuclear cells of study patients. Both metformin and voglibose showed a similar efficacy towards the reduction in HbA_1c and MOS indices. However, multivariate ANCOVA divulged that mRNA and protein expression of mitophagy markers, NLRP3 and p-AMPKα (T172), were significantly increased only with metformin therapy. Moreover, PINK1 expression displayed a significant positive association with HOMA-β indices, and TEM studies further confirmed reduced distortions in mitochondrial morphology in the metformin group only. Our observations underscore that metformin upregulates mitophagy and subsequently ameliorates the altered mitochondrial morphology and function, independent of its glucose-lowering effect. Further, restoration of normal mitochondrial phenotype may improve cellular function, including β-cells, which may prevent further worsening of hyperglycaemia in patients with T2DM.     

Accuracy of glycated haemoglobin in screening for pre-diabetes in Asian Indians-a community survey: the Chandigarh Urban Diabetes Study (CUDS)

Aim To compare American Diabetes Association and International Expert Committee recommended cut-off values of HbA(1c) for detecting the presence of pre-diabetes against plasma glucose values obtained from oral glucose tolerance tests in Asian Indians. Methods A cross-sectional randomly sampled population survey involving 2368 adults, aged ≥?20?years. HbA(1c) was measured on a Bio-Rad 10 system in 1972 subjects. Results Of the 1972 subjects studied, 329 were detected to have pre-diabetes based on isolated impaired fasting glucose in 125 subjects (6.3%), isolated impaired glucose tolerance in 141 subjects (7.1%) and the presence of both in 63 subjects (3.2%). The HbA(1c) cut-off of 34?mmol/mol (5.7%), as recommended by the American Diabetes Association for detecting the presence of pre-diabetes, showed sensitivity of 62%, specificity 77%, with a positive predictive value of 34.7%, a negative predictive value of 89.5% and accuracy of 67.8%; whereas the HbA(1c) cut-off recommended by the International Expert Committee of 42?mmol/mol (6%) had a sensitivity of 36%, specificity of 90%, positive predictive value of 42.7%, negative predictive of 85.4% and an accuracy of 77%. However, both these HbA(1c) cut-offs underdiagnosed the presence of pre-diabetes in 38 and 64% of these subjects, respectively. Conclusions The American Diabetes Association and the International Expert Committee recommended HbA(1c) cut-off values and oral glucose tolerance tests identify different pre-diabetes cohorts. Long-term prospective studies are required to define the usefulness of one over the other.