Electrodermal signal analysis using continuous wavelet transform as a tool for quantification of sweat gland activity in diabetic kidney disease.

Sympathetic innervation of the sweat gland (SG) manifests itself electrically as electrodermal activity (EDA), which can be utilized to measure sudomotor function. Since SG exhibits similarities in structure and function with kidneys, quantification of SG activity is attempted through EDA signals. A methodology is developed with electrical stimulation, sampling frequency and signal processing algorithm. One hundred twenty volunteers participated in this study belonging to controls, diabetes, diabetic nephropathy, and diabetic neuropathy. The magnitude and time duration of stimuli is arrived by trial and error in such a way it does not influence controls but triggers SG activity in other Groups. This methodology leads to a distinct EDA signal pattern with changes in frequency and amplitude. The continuous wavelet transform depicts a scalogram to retrieve this information. Further, to distinguish between Groups, time average spectrums are plotted and mean relative energy (MRE) is computed. Results demonstrate high energy value in controls, and it gradually decreases in other Groups indicating a decline in SG activity on diabetes prognosis. The correlation for the acquired results was determined to be 0.99 when compared to the standard lab procedure. Furthermore, Cohen's d value, which is less than 0.25 for all Groups indicating the minimal effect size. Hence the obtained result is validated and statistically analyzed for individual variations. Thus this has the potential to get transformed into a device and could prevent diabetic kidney disease.

Aldosterone synthase gene is not a major susceptibility gene for progression of chronic kidney disease in patients with autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common heritable kidney disease and is characterized by bilateral renal cysts. Hypertension is a frequent cause of chronic kidney disease (CKD) and mortality in patients with ADPKD. The aldosterone synthase gene polymorphisms of the renin-angiotensin-aldosterone system have been extensively studied as hypertension candidate genes. The present study is aimed to investigate the potential modifier effect of CYP11B2 gene on the progression of CKD in ADPKD. One hundred and two ADPKD patients and 106 healthy controls were recruited based on Ravine inclusion and exclusion criteria. The three tag-SNPs within CYP11B2 gene (rs3802230, rs4543, and rs4544) were genotyped using FRET-based KASPar method. Cochran-Armitage trend test was used to assess the potential associations between these polymorphisms and CKD stages. Mantel- Haenszel stratified analysis was used to explore confounding and interaction effects of these polymorphisms. Of the three tag-SNPs genotyped, rs4544 polymorphism was monomorphic and rs3802230 deviated Hardy-Weinberg equilibrium. The CYP11B2 tag-SNPs did not show significant association with ADPKD or CKD. Further, these polymorphisms did not exhibit confounding effect on the relationship between CKD progression and hypertension. Our results suggest that aldosterone synthase gene is not a major susceptibility gene for progression of CKD in South Indian ADPKD patients.

Influence of angiotensin converting enzyme (ACE) gene rs4362 polymorphism on the progression of kidney failure in patients with autosomal dominant polycystic kidney disease (ADPKD).

BACKGROUND & OBJECTIVES: Autosomal dominant polycystic kidney disease (ADPKD) is an inherited systemic disorder, characterized by the fluid filled cysts in the kidneys leading to end stage renal failure in later years of life. Hypertension is one of the major factors independently contributing to the chronic kidney disease (CKD) progression. The renin-angiotensin aldosterone system (RAAS) genes have been extensively studied as hypertension candidate genes. The aim of the present study was to investigate the role of angiotensin converting enzyme tagging - single nucleotide polymorphisms (ACE tag-SNPs) in progression of CKD in patients with ADPKD. m0 ethods: In the present study six ACE tagSNPs (angiotensin converting enzyme tag single nucleotide polymorphisms) and insertion/deletion (I/D) in 102 ADPKD patients and 106 control subjects were investigated. The tagSNPs were genotyped using FRET-based KASPar method and ACE ID by polymerase chain reaction (PCR) and electrophoresis. Genotypes and haplotypes were compared between ADPKD patients and controls. Univariate and multivariate logistic regression analyses were performed to assess the effect of genotypes and hypertension on CKD advancement. Mantel-Haenszel (M-H) stratified analysis was performed to study the relationship between different CKD stages and hypertension and their interaction. RESULTS: All loci were polymorphic and except rs4293 SNP the remaining loci followed Hardy-Weinberg equilibrium. Distribution of ACE genotypes and haplotypes in controls and ADPKD patients was not significant. A significant linkage disequilibrium (LD) was observed between SNPs forming two LD blocks. The univariate analysis revealed that the age, hypertension, family history of diabetes and ACE rs4362 contributed to the advancement of CKD. INTERPRETATION & CONCLUSIONS: The results suggest that the ACE genotypes are effect modifiers of the relationship between hypertension and CKD advancement among the ADPKD patients.

Renin gene rs1464816 polymorphism contributes to chronic kidney disease progression in ADPKD.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a monogenic disorder and is a common genetic cause of chronic renal failure in children and adults. The enzyme renin plays a key role in the RAAS cascade and an important role in the development of hypertension and progression of renal disease in ADPKD. The present study is aimed to investigate the potential modifier effect of REN gene polymorphisms on the progression of chronic kidney disease (CKD) in ADPKD. METHODS: We analyzed 102 ADPKD patients and 106 healthy controls from the same geographic area. FRET-based KASPar single-nucleotide polymorphism (SNP) genotyping assays for REN gene tag-SNPs (rs2887284, rs2368564, rs1464816, rs7521667, rs10900555, rs6693954, rs6676670 and rs11571078) were performed. Cochran-Armitage trend test was used to assess the potential associations between these polymorphisms and CKD stages. Haplotype frequencies and LD measures were estimated by using the software Haploview. Mantel-Haenszel stratified analysis was used to explore confounding and interaction effects of these polymorphisms. RESULTS: Of the eight tag-SNPs genotyped, the rs10900555 polymorphism deviated from the Hardy-Weinberg equilibrium in controls. The presence of ADPKD in general was not significantly associated with the REN tag-SNPs included in this study. Linkage disequilibrium analysis yielded three haplotype blocks and the haplotypes of the respective blocks are not statistically different between ADPKD and controls. In multivariate analysis, the rs1464816 TG genotype showed a significant association with the advancement of CKD in ADPKD (OR = 4.80; 95 % CI = 1.30-17.82; p = 0.019). CONCLUSIONS: The present study provides evidence that the rs1464816 polymorphism in REN is associated with CKD progression in ADPKD.

Endothelin 1 gene is not a major modifier of chronic kidney disease advancement among the autosomal dominant polycystic kidney disease patients.

Introduction: Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the presence of numerous cysts in the kidney and manifest with various renal and extra-renal complications leading to ESRD. Endothelin may contribute to various renal and extra-renal manifestations pointing to genetic and environmental modifying factors that alter the risk of developing chronic kidney disease (CKD) in ADPKD. In the present study we investigated six genes coding for endothelin 1 ( EDN1 ) tagging-single nucleotide polymorphisms (tag-SNPs) to unravel the EDN1 gene modifier effect for renal disease progression in ADPKD. Materials and Methods: The tag-SNPs were genotyped using FRET-based KASPar method in 108 ADPKD patients and 119 healthy subjects. Cochran-Armitage trend test was used to determine the association between ADPKD and EDN1 tag-SNPs. Multivariate logistic regression analysis was performed to assess the effect of tag-SNPs on CKD progression. The relationship between different CKD stages and hypertension and their interaction Mantel-Haenszel stratified analysis was performed. Results: All loci are polymorphic and followed Hardy-Weinberg equilibrium. Distribution of EDN1 genotypes and haplotypes in control and ADPKD is not statistically significant. Five SNPs covering 3.4 kb forming single LD block, but the LD was not strong between SNPs. The EDN1 genotypes are not contributing to the CKD advancement among the ADPKD patients. Conclusion: These results suggest that the EDN1 gene is not a major modifier of CKD advancement among ADPKD patients.

Role of renin-angiotensin-aldosterone system gene polymorphisms and hypertension-induced end-stage renal disease in autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited disease of the kidneys and is marked by progressive cyst growth and decline in kidney function, resulting in end-stage renal disease (ESRD). Hypertension is thought to be a significant modifying factor in the progression of renal failure in ADPKD. A number of genetic variations involved in renin-angiotensin-aldosterone system (RAAS) pathway genes have clinical or physiological impacts on pathogenesis of hypertension-induced ESRD in ADPKD. Information on RAAS pathway gene polymorphisms and their association with ESRD and ADPKD, published till March 2013, was collected using MEDLINE search. The present review deals with RAAS gene polymorphisms focused on hypertension-induced ESRD in ADPKD in different populations. The results were inconclusive and limited by heterogeneity in the study designs and the population stratification. In lieu of applying next generation sequencing technologies to study complex diseases, it is also possible to apply the same to unravel the complexity of ESRD in ADPKD.

NOS3 tagSNPs does not modify the chronic kidney disease progression in autosomal dominant polycystic kidney disease.

AIM: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary and progressive renal disorder. It is also recognised as the most frequent genetic cause of chronic kidney diseases (CKD). In the present study, four tagging SNPs and two more well studied polymorphisms (Intron 4 VNTR and Glu298Asp) the NOS3 gene were investigated to unravel the potential modifier effect of NOS3 gene on the progression of CKD in ADPKD. METHODS: A total of 102 ADPKD patients and 106 controls were selected for the study. The tagSNPs and Glu298Asp polymorphisms were genotyped using FRET-based KASPar method and intron-4 VNTR by polymerase chain reaction electrophoresis. The genotypes and haplotypes in the controls and ADPKD subjects were analysed by χ(2) tests and haploview software. Mantel-Haenszel stratified and univariate analyses were performed to estimate the influence of different genotypes between different CKD stages and hypertension. RESULTS: The tagSNPs of NOS3 genotypes and haplotypes did not exhibit any significant differences between controls and ADPKD patients. The significant linkage disequilibrium was observed between the rs3918184 and rs2853796 by forming LD block. In univariate analysis, the age and family history of Diabetes mellitus (DM) showed significant association with advancement of CKD, but not with the eNOS polymorphisms. CONCLUSIONS: Our data suggests that there is no evidence for the involvement of NOS3 tag SNPs in the progression to CKD in ADPKD patients. A systematic study using well validated functional SNPs is necessary to clarify the role of the NOS3 gene in the development of CKD in ADPKD.

Improved detection of Mycobacterium tuberculosis using two independent PCR targets in a tertiary care centre in South India.

INTRODUCTION: Tuberculosis (TB) causes significant morbidity and mortality worldwide as one of the leading infectious diseases. In India, more than 1.8 million new cases occur every year. Rapid and accurate diagnosis of TB would improve patient care and limit its transmission. This study aimed to evaluate a dual target polymerase chain reaction (PCR) diagnostic assay to detect Mycobacterium tuberculosis from pulmonary and extra-pulmonary samples at a tertiary care centre in South India. METHODOLOGY: Samples were collected from patients with a low index of suspicion of TB. Acid-fast smears were performed by Auramine O fluorescent microscopy and PCR was performed by using two site-specific primer pairs targeting IS6110 by nested PCR and TRC4 by conventional PCR. Amplified products for IS6110 and/or TRC4 were indicative of M. tuberculosis. RESULTS: Among 114 (19 pulmonary and 95 extra-pulmonary) samples tested by PCR assay, 12 (11%) were positive for both IS6110 and TRC4, of which 11 (10%) were non-respiratory and one was (1%) respiratory in origin. PCR for TRC4 alone was positive for eight (7%) non-respiratory and two (2%) respiratory samples, while IS6110 alone tested positive for six (5%) non-respiratory samples and one (1%) respiratory sample. Of a total of 29 PCR positive samples, 17 (15 %) were acid-fast smear positive. CONCLUSION: Although the target site of IS6110 is specific for M. tuberculosis, some strains from South India may lack this region. Therefore, the use of an additional target site (TRC4) is required for improved detection of M. tuberculosis.