[Show abstract][Hide abstract] ABSTRACT: Altered glycosylation has been associated with oncogenic potential. Relationships of blood types (where expression is due to glycosylation pattern) and HER2/neu (where expression arises due to altered glycosylation) and breast cancer-associated markers like estrogen receptor/progesterone receptor (ER/PR) were examined and related to outcomes in patients with breast cancer.
A population-based retrospective study of 426 surgical breast cancer patients examined relationships between (1) patient characteristics, (2) breast tumor characteristics, and (3) outcomes of women diagnosed at the same medical center over a 10-year period relative to specific molecules defined by glycosylation patterns (eg. blood group, HER2/neu) and (4) ER/PR status.
Following stratification by blood group, subjects exhibited significant differences in tumor size with persons in blood groups A and B having greater numbers of tumors ≤ 2 cm and those with blood types AB and O having tumors >2 cm. After adjusting for age, disease stage, and treatment with trastuzumab, tamoxifen, or aromatase inhibitors, no significant differences were observed in 5-year overall and disease-free survival based on blood type grouping. Blood group B was over-represented among the breast cancer cohort compared to the reference population, while blood group AB was under-represented.
No significant differences were observed in overall and disease-free survival based on blood group. No correlation was noted between HER2/neu, ER or PR status, and blood group type. Among this cohort, HER2/neu positivity was less than 20% and correlated with a 5-year disease-free survival rate ≥ 75% and overall survival of >80% across all blood groups.
Clinical Medicine & Research 11/2011; 9(3-4):111-8. DOI:10.3121/cmr.2011.907
[Show abstract][Hide abstract] ABSTRACT: Although some genes associated with increased risk of Alzheimer Disease (AD) have been identified, few data exist related to gene/gene and gene/environment risk of AD. The purpose of this pilot study was to explore gene/gene and gene/environment associations in AD and to obtain data for sample size estimates for larger, more definitive studies of AD.
The effect of gene/gene and gene/environment interaction related to late onset Alzheimer Disease (LOAD) was investigated in 153 subjects with LOAD and 302 gender matched controls enrolled in the Personalized Medicine Research Project, a population-based bio-repository. Genetic risk factors examined included APOE, ACE, OLR1,and CYP46 genes, and environmental factors included smoking, total cholesterol, LDL, HDL, triglycerides, C-reactive protein, blood pressure, statin use, and body mass index.
The mean age of the cases was 78.2 years and the mean age of the controls was 87.2 years. APOE4 was significantly associated with LOAD (OR=3.55, 95%CL=1.70, 7.45). Cases were significantly more likely to have ever smoked cigarettes during their life (49.3% versus 38.4%, p=0.03). The highest recorded blood pressure and pulse pressure measurements were significantly higher in the controls than the cases (all P<0.005). Although not statistically significant in this pilot study, the relationship of the following factors was associated in opposite directions with LOAD based on the presence of an APOE4 allele: obesity at the age of 50, ACE, OLR1, and CYP46.
These pilot data suggest that gene/gene and gene/environment interactions may be important in LOAD, with APOE, a known risk factor for LOAD, affecting the relationship of ACE and OLR1 to LOAD. Replication with a larger sample size and in other racial/ethnic groups is warranted and the allele and risk factor frequencies will assist in choosing an appropriate sample size for a definitive study.
Clinical Medicine & Research 03/2011; 9(1):17-25. DOI:10.3121/cmr.2010.894
[Show abstract][Hide abstract] ABSTRACT: We previously reported the association of the Z-2 allele of the promoter dinucleotide repeat in the Aldose reductase (ALR2) gene, the (CCTTT)₁₅ allele in the promoter of inductible nitric oxide synthase (iNOS) gene, and the (GT)₁₃ promoter polymorphism in the tumor necrosis factor β (TNFB) gene with an increased risk for diabetic retinopathy (DR), and the Gly82Ser polymorphism in the receptor for advanced glycation end products (RAGE) gene and the (GT)₉ allele of the TNFB gene with low-risk for DR in a hospital-based self-reported type 2 diabetes mellitus (T2DM) patients. We have repeated the study in a population-based south Indian cohort to validate the same variations in these genes.
Type 2 diabetic patients with and without retinopathy (DR+ and DR- respectively) were recruited. (CA)(n) repeat, Gly82Ser, (CCTTT)(n) repeat and (GT)(n) repeat in ALR2, RAGE, iNOS and TNFB genes respectively were genotyped and their frequencies were analyzed using the relevant statistical tests.
Different allelic associations were observed in the present study as compared to our previous reports. Z+2 allele of ALR2, 13-repeat genotype of iNOS, 15-repeat genotype of TNF-β, genes were associated with susceptibility to DR. Gly82Ser polymorphisms of the RAGE gene were not associated with DR in the present study.
The present data show a difference in the association of variations in ALR2, iNOS and TNFB genes with DR, when compared to our previous reports; this could be attributed to differences between the study populations of the past and present report.
[Show abstract][Hide abstract] ABSTRACT: This prospective case study assessed the additional impact of environmental changes (E) within the SAFE strategy in controlling trachoma in two Aboriginal communities (populations 315 and 385) in Central Australia. Baseline levels for trachoma, facial cleanliness, and nasal discharge were measured in children <15 years old. Health and facial cleanliness promotion were initiated in each community and housing and environmental improvements were made in one community. Azithromycin was distributed to all members of each community (coverage 55-73%). Assessments of trachoma and facial cleanliness were made at 3, 6, and 12 months post-intervention. Baseline trachoma rates were similar for the two communities (48 and 50%). Rates were significantly lower at 3, 6, and 12 months compared to baseline, but there was no significant difference between the two communities. The A/F components of the SAFE strategy significantly reduced the prevalence of trachoma; however, while the E intervention did not bring any apparent benefits, several factors might have masked them.
International Ophthalmology 04/2010; 30(4):367-75. DOI:10.1007/s10792-010-9360-5 · 0.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Polymorphisms in protein kinase C beta (PRKCB1) and pigment epithelium derived factor (PEDF) genes have been associated with diabetic nephropathy and retinopathy respectively. Association of promoter polymorphisms-1504C/T and-1440G/T in PRKCB1 gene and sequence variations in exon 4 of PEDF gene are studied with diabetic retinopathy (DR) in a south Indian population based cohort.
Type 2 diabetic patients with and without retinopathy (DR+ and DR- respectively) were recruited. The promoter region of PRKCB1 gene and exon 4 of PEDF genes were sequenced by polymerase chain reaction based direct sequencing and their frequencies were analyzed using relevant statistical tests.
The genotype and alleles of the two promoter polymorphisms of PRKCB1 gene were uniformly distributed among DR+ and DR- and hence were not associated with the disease. The haplotypes were also not significantly associated with DR. A T130T polymorphism observed in the PEDF gene showed modest association with absence of diabetic retinopathy.
Our results suggest lack of association of PRKCB1 gene promoter polymorphisms and moderate protective association of PEDF gene polymorphism with DR in the south Indian population.
[Show abstract][Hide abstract] ABSTRACT: In vitro and in vivo animal studies suggest that dietary carbohydrates play a role in cataractogenesis. Few epidemiologic studies have been conducted to evaluate this association. The objective of this study was to examine the cross-sectional associations between total carbohydrate intake, dietary glycemic index (dGI), and the risk of cortical and nuclear cataracts.
After excluding 864 persons from 2473 eligible participants, 1609 eligible nondiabetic participants (mean age, 57.6 years, 55.9% female) in the Melbourne Visual Impairment Project (VIP) were enrolled. Dietary information derived from a semiquantitative food-frequency questionnaire and cataract status graded by the Wilmer protocol (cortical cataract: opacity >or=4/16; nuclear cataract grade >or=2) were collected. With the use of the generalized estimating approach to logistic regression to account for the lack of independence between the eyes of an individual, the associations between dietary carbohydrates and risk of cataract in eyes with no or a single type (pure) of cataract were examined.
Multivariate adjustment showed that pure cortical cataract (197 eyes) was significantly associated with total carbohydrate intake (odds ratio [OR] comparing the highest quartile with the lowest quartile = 3.19, 95% confidence interval [CI] = 1.10-9.27; P(trend) = 0.017). The OR for nuclear cataract (366 eyes) comparing the third quartile of dGI with the first quartile (OR = 1.64, 95% CI = 1.02-2.65) was significant, but there was not a consistent dose-response association (P(trend) = 0.75).
Carbohydrate intake may be optimized to prolong eye lens function. Because of the high proportion of subjects with missing covariates, these results warrant further study.
[Show abstract][Hide abstract] ABSTRACT: We tested the hypothesis that genetic variation in vitamin D-dependent signaling is associated with congestive heart failure in human subjects with hypertension.
Functional polymorphisms were selected from five candidate genes: CYP27B1, CYP24A1, VDR, REN and ACE. Using the Marshfield Clinic Personalized Medicine Research Project, we genotyped 205 subjects with hypertension and congestive heart failure, 206 subjects with hypertension alone and 206 controls (frequency matched by age and gender).
In the context of hypertension, a SNP in CYP27B1 was associated with congestive heart failure (odds ratio: 2.14 for subjects homozygous for the C allele; 95% CI: 1.05-4.39).
Genetic variation in vitamin D biosynthesis is associated with increased risk of heart failure.
[Show abstract][Hide abstract] ABSTRACT: To explore the attitudes of staff caring for institutionalised dementia residents and the variables associated with these attitudes.
Fourteen nursing homes and one hospital-based geriatric ward in Bergen, Norway were surveyed, using the translation of an Approach to Dementia Questionnaire. The study population (n = 291) was a mixture of registered nurses, auxiliary nurses, nursing assistants and non-trained aides.
Significant differences in hope and person-centred attitudes were identified in this study. Nursing assistants, compared with registered nurses (p = 0.02), had significantly lower hope attitudes. Staff over 50 years of age reported significantly lower hope attitudes (p = 0.01) than those under 40 years of age. Staff with 10 and fewer years of work experience reported significantly lower hope attitudes (p = 0.02) than those with more than 10 years of experience. Nurses with specialised training in geriatrics, psychiatry or dementia care had significantly higher hope attitudes, compared with nurses without any special training (p = 0.04). The person-centred attitude was lower among participants who were over 50 years old, compared with their counterparts under the age of 40 (p < or = 0.01).
Education, age, work experience, care unit size and specialised training are associated with differences in attitudes. We recommend that employers be proactive in encouraging and facilitating staff development by offering further training that aims to impart more positive attitudes.
Improvements in staff competency levels will be more important in the future, as a result of the forecasted increase in the percentage of the population who will suffer from dementia and reside in nursing homes.
[Show abstract][Hide abstract] ABSTRACT: To compare the clinicopathologic features and survival in the four breast cancer subtypes defined by immunohistochemistry (IHC) expression of estrogen receptor (ER) or progesterone receptor (PR) and human epidermal growth factor receptor 2 (Her2): ER/PR+, Her2+; ER/PR+, Her2-; ER/PR-, Her2+; and ER/PR-, Her2-.
A 7-year retrospective study of 1134 invasive breast cancer subjects. Clinical and pathologic features and survival of the four subtypes were compared.
Using ER/PR+ and Her2- as a reference, ER/PR-, Her2- had the worst overall survival (hazard ratio, 1.8; 95% confidence interval [CI], 1.06-3.2) and the worst disease-free survival (hazard ratio, 1.5; 95% CI, 0.8-3.0). In ER/PR+, Her2-, chemotherapy conferred significant overall and disease-free survival advantages. Subtype comparison revealed statistically significant differences in outcomes.
The triple negative subtype has the worst overall and disease free survival. Efforts should be directed at standardization of current testing methods and development of more reliable and reproducible testing.
Clinical Medicine & Research 07/2009; 7(1-2):4-13. DOI:10.3121/cmr.2009.825
[Show abstract][Hide abstract] ABSTRACT: A cohort of postmenopausal osteoporotic females and controls with normal bone mineral density, the interleukin 6 (IL6) -634G > C (rs1800796) C allele of the promoter region showed association with osteoporosis. The lipoprotein receptor-related protein 5 (LRP5) gene showed association between C135242T C/T alleles and osteoporosis only in smokers, suggesting a role for environmental interaction.
A nested case-control study within a population-based cohort was undertaken to assess the relative impact of cigarette smoking, statin use, genetic polymorphisms, and one-way interaction of these factors on development of osteoporosis in postmenopausal women.
Genotyping of 14 single-nucleotide polymorphisms (SNPs) corresponding to vitamin D receptor gene, estrogen receptor 1, collagen type 1 alpha 1, IL6, transcription growth factor beta, apolipoprotein E, and LRP5 genes was performed in cases (n = 309) with osteoporosis and controls (n = 293) with normal bone mineral density drawn from a homogeneous Caucasian population. SNPs were chosen based on known functional consequences or prior evidence for association and genotyped using matrix-assisted laser desorption ionization time-of-flight technology.
Cases differed from controls relative to body mass index, age, and smoking but not statin use. After adjusting for age, the IL6 -634G > C (rs1800796) allele showed association with osteoporosis (odds ratio (OR) for CC + CG = 2.51, p = 0.0047)), independent of statin use or smoking status. On stratification for smoking, association with LRP5 C135242T (rs545382) and osteoporosis emerged (OR 2.8 in smokers for CT alleles, p = 0.03)), suggestive of potential environmental interaction.
Evidence suggested a role for genetic variation in IL6 and LRP5 in conferring risk for osteoporosis in Caucasian women, with the latter manifest only in smokers.
Osteoporosis International 06/2009; 21(3):467-77. DOI:10.1007/s00198-009-0981-3 · 4.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective Four breast cancer subtypes defined by immunohistochemistry (IHC) expression of estrogen receptor (ER) or progesterone receptor (PR) and human epidermal growth factor receptor 2 (Her2) are ER/PR+,Her2+; ER/PR+,Her2-; ER/PR-,Her2+; and ER/PR-,Her2-. Methods A 7-year retrospective study of 1134 invasive breast cancer subjects. Clinical and pathologic features and survival of the four subtypes were compared. Results Using ER/PR+ and Her2- as a reference, ER/PR-,Her2- had worst overall survival (hazard ratio, 1.8; 95% confidence interval [CI], 1.06-3.2), and worst disease-free survival (hazard ratio, 1.5; 95% CI, 0.8-3.0). In ER/PR+,Her2-, chemotherapy conferred significant overall and disease-free survival advantages. Subtype comparison revealed statistically significant differences in outcomes. Conclusion Triple negative subtype having worst overall and disease free survival. Efforts should be directed at standardization of current testing methods and development of more reliable and reproducible testing.
Clinical Medicine & Research 02/2009; 7(1-2). DOI:10.3121/cmr.2008.825
[Show abstract][Hide abstract] ABSTRACT: Small cell lung cancer (SCLC) represents 15% to 25% of lung cancers. Despite favorable initial treatment response rates, recurrence is likely and long-term prognosis dismal. Accurate measurement of therapy response is critical to determine which patients might be spared additional treatment, and potential side effects. (18)F-fluorodeoxyglucose positron emission tomography (PET) may help distinguish necrotic or fibrous tissue from residual cancer, thus informing further treatment and prognosis. DESIGN/SETTING/PARTICIPANTS AND METHODS: Retrospective chart review study of limited stage SCLC patients with PET scanning within 4 months post-chemotherapy at Marshfield Clinic, Marshfield, Wisconsin. Diagnosis of SCLC occurred from December 1, 2001 through December 31, 2007.
Twenty-two patients (approximately 7%) had post-treatment PET: 11 positive, 11 negative. Median duration from last chemotherapy to PET was 36 days (range, 3 to 125 days). Median follow-up for all patients was 34.4 months (range, 6.8 to 65.9 months). Estimated median progression-free survival for all patients was 8.1 months (95% confidence intervals [CI], 4.3 to 11.9 months), 10.5 months for PET negative (95% CI, 8.1 to >57.8 months) and 4.3 months for PET positive patients (95% CI, 2.8 to >7.2 months) (P<0.007, log-rank test). Median survival for all patients was 19.2 months (95% CI, 10.3 to >65.8 months). Estimated median survival for PET negative patients was longer than PET positive (29.2 versus 10.3 months, P=0.10).
Post-treatment PET, prognostically significant, may be underutilized.
Clinical Medicine & Research 10/2008; 6(2):72-7. DOI:10.3121/cmr.2008.797
[Show abstract][Hide abstract] ABSTRACT: To estimate glaucoma and ocular hypertension prevalence and to describe temporal trends in prescribing patterns and intraocular pressure (IOP) response to topical medications used in glaucoma and ocular hypertension.
The medical records of adult subjects enrolled in the population-based Marshfield Clinic Personalized Medicine Research Project were searched to identify participants who had been diagnosed with ocular hypertension or glaucoma and prescribed agent(s) to lower IOP. All IOPs before and after prescription of the IOP agents were recorded.
As of December 31, 2005, 18,773 adults were enrolled in the Personalized Medicine Research Project, 57.1% were female, and their mean age was 50.3 years (range, 18 to 101 y). The overall rate of definite glaucoma in subjects aged 50 years and above was 2.1% (95% confidence interval=1.2, 2.4) and the rate of treated ocular hypertension was 1.4% (95% confidence interval=1.2, 1.7). Topical beta-blockers were the agents prescribed for the majority of subjects until the year 2000, when prostaglandins, first used in 1995, became the primary agent prescribed. In 2005, 75% of subjects used prostaglandin analogs and 46% used topical beta-blockers. The largest relative reduction in IOP in the first 3 months after prescription was observed for prostaglandin analogs (21.4% mean relative reduction), followed by beta-blockers (20.9% mean relative reduction). There has been a significant decrease over time in mean IOP before initiating medical therapy (linear regression beta coefficient=-0.30, P<0.0001, r=0.09).
In this clinic-based setting, we found that treatment of glaucoma has changed over the past 20 years, with ophthalmologists more likely to begin treatment at lower baseline levels of IOP, and prostaglandin analogs the most commonly prescribed and agent to lower IOP.
Journal of glaucoma 08/2008; 17(5):372-7. DOI:10.1097/IJG.0b013e31815c5f3f · 2.43 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To determine whether candidate pharmacodynamic (beta-adrenergic receptor) and pharmacokinetic (cytochrome P450 2D6) gene polymorphisms are associated with the intraocular pressure (IOP) response to topical beta-blockers.
Medical records of 18,773 adults in the Personalized Medicine Research Project were searched to extract all IOP measurements for subjects who had been prescribed a topical beta-blocker. Five single-nucleotide polymorphisms in the beta(1)-, beta(2)-, and beta(3)-adrenergic receptor genes and 6 polymorphisms in the CYP2D6 gene were genotyped.
A total of 58.1% of the subjects were female; the mean age was 63.8 years. Topical beta-blockers were prescribed for 343 eyes of 215 subjects. An IOP reduction of 20% or more in 1 or both eyes was observed in 61.0% of subjects. Men were significantly more likely than women to have an IOP decrease of 20% or more (69.3% vs 54.9%, respectively; chi(2) = 4.48; P = .04). After adjusting for sex, family history of glaucoma, and use of systemic beta-blockers, subjects with the CC genotype at coding single-nucleotide polymorphism rs1042714 in the ADRB2 gene were significantly more likely to experience an IOP decrease of 20% or more (odds ratio, 2.00; 95% confidence interval, 1.00-4.02).
We found that a coding single-nucleotide polymorphism in ADRB2 is associated with an increased likelihood of a clinically meaningful IOP response to topical beta-blockers. Clinical Relevance Because topical beta-blockers are the least expensive class of agents used to lower IOP, genotype-based drug prescribing could save health care dollars.
Archives of ophthalmology 08/2008; 126(7):959-63. DOI:10.1001/archopht.126.7.959 · 4.49 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: THE INSTITUTIONAL REVIEW BOARD-RESEARCHER ASSESSMENT TOOL (IRB-RAT) was designed to assess the relative importance of various factors to the effective functioning of IRBs. We employed the IRB-RAT to gain insight into the ways in which our IRB is perceived to be deficient by those who routinely interact with our Office of Research Integrity and Protections. Respondents ranked qualities thought to be characteristic of an "ideal" IRB and then compared our IRB to that internal standard. We observed that the rate of study participation varied by role. The composite relative ranking of the 45 items that comprise the IRB-RAT differed significantly from the rank order reported by Keith-Spiegel et al. Our data furthermore suggest that role influences scoring of the IRB-RAT (e.g., investigators awarded our IRB significantly higher scores in several areas than did research coordinators). Additional research is warranted to determine if the observed role-dependent differences in the perceived quality of our IRB simply reflect the local research culture or if they are indicative of a more fundamental and generalizable difference in outlook between investigators and research coordinators.
Journal of Empirical Research on Human Research Ethics 04/2008; 3(1):25-34. DOI:10.1525/jer.2008.3.1.25 · 1.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Barrett's esophagus (BE) predisposes to adenocarcinoma of the esophagus and survival in esophageal adenocarcinoma is low. We studied patients diagnosed with BE in the Marshfield Epidemiologic Study Area (MESA). Our objectives were to estimate the prevalence of diagnosed BE, estimate the annual incidence of initial diagnosis of BE, and characterize the demographics of patients diagnosed with BE.
We retrospectively reviewed medical records of patients diagnosed with BE until December 31, 2002. The esophagogastroduodenoscopy (EGD) reports were reviewed to establish the presence of columnar epithelium. All slides were retrieved and reviewed by a gastrointestinal pathologist to establish the presence of intestinal metaplasia and dysplasia. Chart abstraction was conducted using a standardized form.
BE was histologically confirmed in 216 patients. All were white, 165 (76%) were male, and 81% had a hiatal hernia. Median age at diagnosis was 65.5 yr (range 17-94). Long-segment BE (LSBE) was present in 112 (51.9%) patients. The prevalence of histologically confirmed BE in MESA was 261.8 (95% CI 222.5-301.1) per 100,000 people. The incidence of an initial diagnosis of BE between 1996 and 2002 was 32.7 per 100,000 person-years (95% CI 27.1-38.2) and did not change significantly over the study period despite an increase in EGD rates. At the initial diagnosis, 41.7% of the patients were on proton pump inhibitors. Dysplasia was present in 24.5% of patients.
The incidence of initial diagnosis of BE in a stable white population did not change significantly over a 7-yr period, despite an increase in EGD rates.
The American Journal of Gastroenterology 04/2008; 103(3):516-24. DOI:10.1111/j.1572-0241.2007.01599.x · 9.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Polymorphisms in vascular endothelial growth factor (VEGF) gene have been associated with diabetic retinopathy (DR) in various populations. A promoter polymorphism and a 3'UTR variation are studied for association with DR.
Type 2 diabetic patients with and without retinopathy were recruited. The -634C/G and 936C/T polymorphisms were genotyped by direct sequencing and their frequencies were analyzed using relevant statistical tests.
No significant association was observed between genotypes, alleles and haplotypes of -634C/G and 936C/T polymorphisms and DR or its severity. However, C(-634)G genotype was found to increase the risk for DR in patients with microalbuminuria (OR: 8.9, 95% CI: 1.4, 58.3).
Our study broadly suggests lack of association of VEGF gene polymorphisms with DR.
[Show abstract][Hide abstract] ABSTRACT: There are different teaching styles for delivering competency-based curricula. The education literature suggests that learning is maximized when teaching is delivered in a style preferred by learners.
To determine if dermatology residents report learning style preferences aligned with adult learning.
Dermatology residents attending an introductory cutaneous biology course completed a learning styles inventory assessing self-reported success in 35 active and passive learning activities. The 35 learning activities were ranked in order of preference by learners.
Mean overall ratings for active learning activities were significantly higher than for passive learning activities (P = 0.002).
Trends in dermatology resident learning style preferences should be considered during program curriculum development. Programs should integrate a variety of curriculum delivery methods to accommodate various learning styles, with an emphasis on the active learning styles preferred by residents.
Medical Teacher 02/2008; 30(4):420-5. DOI:10.1080/01421590801946988 · 2.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A 27-bp variable number tandem repeat (VNTR) in intron 4 of endothelial nitric oxide synthase (eNOS) gene has been associated with the risk for developing diabetic retinopathy (DR) in various ethnic populations. Hundred and eighty seven patients with retinopathy (cases; DR+) and 188 patients without retinopathy (controls: DR-) from southern India who had type 2 diabetes mellitus (T2DM) for more than 10 years, were included in the study. We could neither find significant allelic association with clinical severity of DR nor with macular edema. Our results suggest lack of association of intron 4 VNTR of eNOS gene with DR in southern India.