Oxidative stress, endothelial function, carotid artery intimal thickness and their correlates among chronic peritoneal dialysis patients

We evaluated important nontraditional cardiovascular risk factors, endothelial function and oxidative stress (OS) among stable peritoneal dialysis (PD) patients. Their association with carotid intimal medial thickness (CIMT) was also assessed. Thirty-eight adult patients (13 diabetics, 20 males) on PD for >6 months and 15 age and sex-matched controls were studied. Duration of dialysis (DOD), residual urine output (UO), weekly Kt/V urea, detailed biochemical and lipid profile were noted. OS was measured by serum concentration of antioxidants; vitamin C and ferric reducing ability of plasma (FRAP) and pro-oxidant; thiobarbituric acid-reactive substances (TBARS). High-resolution ultrasonography was used to determine CIMT and flow-mediated dilatation of brachial artery [endothelium-dependent dilatation (EDD)] and dilatation subsequent to nitrate spray [endothelium-independent dilatation (EID)]. Mean age, DOD, UO and Kt/V of study population were 49.3 ± 11.6 years, 19.4 ± 11.8 months, 508.2 ± 422.9 ml/day and 1.73 ± 0.24, respectively. As compared to controls PD patients had higher CIMT (0.46 ± 0.05 vs 0.50 ± 0.07 mm, P = 0.003) and TBARS (1.5 ± 0.4 vs 5.1 ± 2.3 nM/ml, P < 0.001) but lower Vitamin C (1.7 ± 0.3 vs 0.6 ± 0.2 mg%, P < 0.001), FRAP (990.8 ± 78.1 vs 328.7 ± 183.5 μM/L, P < 0.001) and EDD (26.2 ± 5.4 vs 9.8 ± 4.6 %, P < 0.001). TBARS correlated positively with DOD and negatively with hemoglobin. Vitamin C and FRAP correlated positively with serum albumin. EDD correlated positively with UO, Kt/V and hemoglobin. CIMT correlated negatively with Kt/V and hemoglobin. Among themselves CIMT correlated negatively with EDD and vitamin C. EDD correlated positively with vitamin C, while FRAP correlated positively with vitamin C and negatively with TBARS. PD patients have higher OS, poorer endothelial function and higher structural atherosclerosis. These parameters are closely linked to each other, hemoglobin, DOD, residual UO, serum albumin and small solute clearances.

Type 2 diabetes, glucose homeostasis and incident atrial fibrillation: the Atherosclerosis Risk in Communities study

BACKGROUND

Type 2 diabetes has been inconsistently associated with the risk of atrial fibrillation (AF) in previous studies that have frequently been beset by methodological challenges.

DESIGN

Prospective cohort study.

SETTING

The Atherosclerosis Risk in Communities (ARIC) study.

PARTICIPANTS

Detailed medical histories were obtained from 13 025 participants. Individuals were categorised as having no diabetes, pre-diabetes or diabetes based on the 2010 American Diabetes Association criteria at study baseline (1990-2).

MAIN OUTCOME MEASURES

Diagnoses of incident AF were obtained to the end of 2007. Associations between type 2 diabetes and markers of glucose homeostasis and the incidence of AF were estimated using Cox proportional hazards models after adjusting for possible confounders.

RESULTS

Type 2 diabetes was associated with a significant increase in the risk of AF (HR 1.35, 95% CI 1.14 to 1.60) after adjustment for confounders. There was no indication that individuals with pre-diabetes or those with undiagnosed diabetes were at increased risk of AF compared with those without diabetes. A positive linear association was observed between HbA1c and the risk of AF in those with and without diabetes (HR 1.13, 95% CI 1.07 to 1.20) and HR 1.05, 95% CI 0.96 to 1.15 per 1% point increase, respectively). There was no association between fasting glucose or insulin in those without diabetes, but a significant association with fasting glucose was found in those with the condition. The results were similar in white subjects and African-Americans.

CONCLUSIONS

Diabetes, HbA1c level and poor glycaemic control are independently associated with an increased risk of AF, but the underlying mechanisms governing the relationship are unknown and warrant further investigation.

White blood cell count, C-reactive protein, and incident heart failure in the Atherosclerosis Risk in Communities (ARIC) Study

PURPOSE

To test the hypothesis that inflammation measured by white blood cell count (WBC) and C-reactive protein (CRP) is associated positively with incident heart failure (HF).

METHODS

Using the Atherosclerosis Risk in Communities (ARIC) Study, we conducted separate Cox proportional hazards regression analyses for WBC (measured 1987-1989) and CRP (measured 1996-1998) in relation to subsequent heart failure occurrence. A total of 14,485 and 9,978 individuals were included in the WBC and CRP analyses, respectively.

RESULTS

There were 1647 participants that developed HF during follow-up after WBC assessment and 613 developed HF after CRP assessment. After adjustment for demographic variables and traditional HF risk factors, the hazard ratio (95% confidence interval) for incident HF across quintiles of WBC was 1.0, 1.10 (0.9-1.34), 1.27 (1.05-1.53), 1.44 (1.19-1.74), and 1.62 (1.34-1.96), p trend < .001; hazard ratio across quintiles of CRP was 1.0, 1.03 (0.68-1.55), 0.99 (0.66-1.51), 1.40 (0.94-2.09), and 1.70 (1.14-2.53), p trend .002. Granulocytes appeared to drive the relation between WBCs and heart failure (hazard ratios across quintiles: 1.0, 0.93 [0.76-1.15], 1.26 [1.04-1.53], 1.67 [1.39-2.01], and 2.19 [1.83-2.61], p trend < .0001), whereas lymphocytes or monocytes were not related.

CONCLUSIONS

Greater levels of WBC (especially granulocytes) and CRP are associated with increased risk of heart failure in middle-aged adults, independent of traditional risk factors.

Collapsing glomerulopathy in renal allograft biopsies: A study of nine cases

Collapsing glomerulopathy (CG) is considered to be a distinct clinicopathologic pattern of proliferative podocyte injury. The clinical significance of CG in renal allograft biopsies is yet not clear due to the scant data on the occurrence of CG in renal transplant recipients. We identified nine cases of CG in allograft biopsies over a period of 2 years. Detailed clinical information, including follow-up data, was collected and histopathological analysis performed. All the nine patients were males with a mean age at diagnosis of 32.4±11.2 years. The median posttransplantation duration at diagnosis of CG as 52 (range 12–98) months. All the patients presented with severe proteinuria and graft dysfunction. Histological analysis showed a median number of 8 glomeruli. The collapse of the glomerular tuft with visceral epithelial cell hyperplasia involved median of 2 glomeruli (range 1–4). At the last follow-up (mean duration 6 months), four patients had graft failure (return to dialysis) while four had functioning grafts. One patient was lost to follow-up. This series emphasizes the importance of this rare glomerular pathology as an important cause of graft dysfunction that may lead to allograft failure.

The impact of VKORC1-1639 G>A polymorphism on the maintenance dose of oral anticoagulants for thromboembolic prophylaxis in North India: A pilot study

BACKGROUND

The dose requirements for oral anticoagulants in thromboembolic events are influenced by promoter polymorphism in the VKORC1 gene. However, limited data are available on the influence of the polymorphism in various Indian populations. The present study aimed at determining the relationship between the VKORC1-1639 G>A genotypes and maintenance doses of oral anticoagulants for therapeutically stable INR values in patients taking Acitrom after valve replacement surgery.

MATERIALS AND METHODS

Fifty patients from the northern Indian region were genotyped for VKORC1-1639 G>A by polymerase chain reaction and restriction fragment length polymorphism. Means of the weight-normalized daily Acitrom dose were calculated for every patient.

RESULTS AND DISCUSSION

The VKORC1 1639G>A minor allele frequency in the study population (n = 50) was found to be 22%. The patients with a wild type genotype required the maximum drug dose as suggested for full functionality of the enzyme. Heterozygous patients were found to have an intermediate drug dose and the patients with a variant homozygous genotype had the minimum maintenance drug dose requirement. These findings are in concurrence with the effect of the promoter polymorphism on vitamin K epoxide reductase activity.1639G>A minor allele frequency in the study population (n = 50) was found to be 22%. The patients with a wild type genotype required the maximum drug dose as suggested for full functionality of the enzyme. Heterozygous patients were found to have an intermediate drug dose and the patients with a variant homozygous genotype had the minimum maintenance drug dose requirement. These findings are in concurrence with the effect of the promoter polymorphism on vitamin K epoxide reductase activity.

CONCLUSION

The VKORC1-1639 G>A status can be indicative of establishing the therapeutic dose of oral anticoagulants in Indian patients.

Tuberculin skin test for the diagnosis of latent tuberculosis during renal replacement therapy in an endemic area: A single center study

Patients on renal replacement therapy (RRT) are at-risk for developing tuberculosis (TB). There is limited information on tuberculin skin test (TST) and its predictability for development of TB. In this prospective cohort study, patients taken for RRT were included. Patients with active TB were excluded. TST was done with 5-tuberculin unit. In addition to TST, age, sex, diabetes as basic disease, number of dialysis and blood transfusion (BT), pre-transplant TB, hepatitis B and C infections and type of immunosuppression were correlated with the development of TB. Of the 200 patients included, TST was positive in 21 and negative in 179. In TST negative group, 20 (11.1%) and in TST positive group 5 (23.8%) patients developed TB. TB free survival in two groups was similar (P = 0.08). On multivariate Cox regression analysis, hazard of development of TB by TST was 2.7 [P = 0.11, confidence interval (CI) 0.78-9.7]. There was no difference between TST non-responsive and TST negative patients (P = 0.18). Sensitivity and specificity of TST for predicting TB was only 20 and 9%, respectively. Our study shows that TST in patients on dialysis is an insensitive and nonspecific test to predict development of active TB.

Efficacy and tolerability of lamivudine in hepatitis B infected renal transplant recipients: A single center study

Hepatitis B virus (HBV) infection in patients on hemodialysis and renal transplantation (RT) usually has an unfavorable course. Lamivudine is a synthetic nucleoside analog with a potent action on HBV replication. There is limited data on lamivudine in renal transplant patients with HBV infection and no published report from India. Present study reports on lamivudine therapy in these patients. Patients with HBV infection taken for RT were included. Hepatitis B surface antigen (HBsAg), hepatitis B envelope antigen (HBeAg), HBV-DNA, and liver biopsy before RT were done in all patients. Lamivudine was given in the dose of 50 mg daily during the dialysis and 100 mg daily following successful transplant. Response was evaluated at one year. Of the 739 adult RTs during study period, 35 (4.7%) had HBV infection. Mean age of patients was 30.7 +/- 9.8 (16-55 years) and 88.5% were males. Four (11.4%) patients had HCV coinfection. HCV was not treated in any patient. All patients were HBsAg and HBV-DNA positive, while 27 (77%) were HBeAg positive. Mean ALT was 77.8 +/- 90 IU/dl; 11 (31.4%) patients had normal ALT. Mean liver biopsy grade was 5.2 +/- 1.5 (3-9) and stage was 0.7 +/- 0.6 (0-2). At one year following transplantation, ALT was normal in 27 (77%) cases, HBV-DNA undetectable in 16 (45.7%), HBeAg and HBsAg seroconversion in 8 (22.8%), and 3 (8.6%) cases, respectively. All patients tolerated the drug without any significant side effects. Treatment with lamivudine in dialysis and renal transplant patients is well tolerated and safe with efficacy comparable to patients with normal renal function.

Chronic kidney disease is associated with the incidence of atrial fibrillation: the Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND

Chronic kidney disease is associated with the incidence of cardiovascular disease. Chronic kidney disease may also increase the risk of atrial fibrillation (AF), but existing studies have reported inconsistent results.

METHODS AND RESULTS

We estimated cystatin C-based glomerular filtration rate (eGFR(cys)) and measured urinary albumin-to-creatinine ratio (ACR) in 10 328 men and women free of AF from the Atherosclerosis Risk in Communities (ARIC) Study in 1996 to 1998. Incidence of AF was ascertained through the end of 2007. During a median follow-up of 10.1 years, we identified 788 incident AF cases. Compared with individuals with eGFR(cys) ≥90 mL · min(-1) · 1.73 m(-2), multivariable hazard ratios and 95% confidence intervals (CIs) of AF were 1.3 (95% CI, 1.1 to 1.6), 1.6 (95% CI, 1.3 to 2.1), and 3.2 (95% CI, 2.0 to 5.0; P for trend <0.0001) in those with eGFR(cys) of 60 to 89, 30 to 59, and 15 to 29 mL · min(-1) · 1.73 m(-2), respectively. Similarly, the presence of macroalbuminuria (ACR ≥300 mg/g; hazard ratio, 3.2; 95% CI, 2.3 to 4.5) and microalbuminuria (ACR, 30 to 299 mg/g; hazard ratio, 2.0; 95% CI, 1.6 to 2.4) was associated with higher AF risk compared with those with ACR <30 mg/g. Risk of AF was particularly elevated in those with both low eGFR(cys) and macroalbuminuria (hazard ratio, 13.1; 95% CI, 6.0 to 28.6, comparing individuals with ACR ≥300 mg/g and eGFR(cys) of 15 to 29 mL · min(-1) · 1.73 m(-2) and those with ACR <30 mg/g and eGFR(cys) ≥90 mL · min(-1) · 1.73 m(-2)).

CONCLUSION

In this large population-based study, reduced kidney function and presence of albuminuria were strongly associated with the incidence of AF independently of other risk factors.

Sources of variability in measurements of cardiac troponin T in a community-based sample: the atherosclerosis risk in communities study

BACKGROUND

Application of cardiac troponin T (cTnT) as a marker of myocyte damage requires knowledge of its measurement variability. Using a highly sensitive assay for measurement, we evaluated the long-term storage stability of plasma cTnT at -70 °C and the sources of cTnT variability.

METHODS

Samples from the Atherosclerosis Risk in Communities study collected in 1996-1998 and 2005-2006 were assayed centrally to quantify variability in cTnT attributable to processing (replicates from same blood draw, n = 87), laboratory (replicates after freeze thaw, n = 29), short-term (n = 40) and long-term biological variation (repeat visit, n = 38), and degradation in frozen storage (n = 7677).

RESULTS

Approximately 30% of this population-based cohort had cTnT concentrations below the detection limit (3 ng/L). Reliability coefficients for all paired comparisons exceeded 0.93 except for samples drawn 8 years apart (r = 0.36). Sources of cTnT variation (as CVs) were: laboratory, 2.1% and 11.2% in those with and without heart failure, respectively; processing, 18.3%; biological, 16.6% at 6 weeks and 48.4% at 8 years. The reference change value at 6 weeks (68.5%) indicated that 4 samples are needed to determine a homeostatic set point within ±25%. The estimated cTnT degradation rate over the first year in long-term frozen storage was 0.36 ng/L per year.

CONCLUSIONS

cTnT was detectable in approximately 70% of community-dwelling middle-aged study participants and stable in -70 °C storage. The variability in cTnT attributable to 1 freeze-thaw cycle is of small magnitude. The observed high laboratory and intraindividual (biological) reliability of cTnT support its use for population-based research, and in clinical settings that rely on classification and serial measurements.

Absolute and attributable risks of atrial fibrillation in relation to optimal and borderline risk factors: the Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND

Atrial fibrillation (AF) is an important risk factor for stroke and overall mortality, but information about the preventable burden of AF is lacking. The aim of this study was to determine what proportion of the burden of AF in blacks and whites could theoretically be avoided by the maintenance of an optimal risk profile.

METHODS AND RESULTS

This study included 14 598 middle-aged Atherosclerosis Risk in Communities (ARIC) Study cohort members. Previously established AF risk factors, namely high blood pressure, elevated body mass index, diabetes mellitus, cigarette smoking, and prior cardiac disease, were categorized into optimal, borderline, and elevated levels. On the basis of their risk factor levels, individuals were classified into 1 of these 3 groups. The population-attributable fraction of AF resulting from having a nonoptimal risk profile was estimated separately for black and white men and women. During a mean follow-up of 17.1 years, 1520 cases of incident AF were identified. The age-adjusted incidence rates were highest in white men and lowest in black women (7.45 and 3.67 per 1000 person-years, respectively). The overall prevalence of an optimal risk profile was 5.4% but varied according to race and gender: 10% in white women versus 1.6% in black men. Overall, 56.5% of AF cases could be explained by having ≥ 1 borderline or elevated risk factors, of which elevated blood pressure was the most important contributor.

CONCLUSION

As with other forms of cardiovascular disease, more than half of the AF burden is potentially avoidable through the optimization of cardiovascular risk factors levels.

Smoking and incidence of atrial fibrillation: results from the Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND

Cigarette smoking increases the risk of coronary heart disease, but whether smoking increases atrial fibrillation (AF) is uncertain.

OBJECTIVE

The purpose of this study was to determine the association of cigarette smoking with incident AF in a population-based cohort of blacks and whites.

METHODS

We determined the risk of incident AF through December 2002 in relation to baseline (1987-1989) smoking status and cigarette-years of smoking in over 15,000 participants of the prospective Atherosclerosis Risk in Communities (ARIC) study.

RESULTS

Over a mean follow-up of 13.1 years, 876 incident AF events were identified. Compared to never smokers, the multivariable-adjusted hazard ratios (HRs) for AF were 1.32 (95% confidence interval [CI] 1.10-1.57) in former smokers, 2.05 (95% CI 1.71-2.47) in current smokers, and 1.58 (95% CI 1.35-1.85) in ever smokers. In the highest tertile of accumulated smoking amount (>675 cigarette-years), the incidence of AF was 2.10 times greater (95% CI 1.74-2.53) than in those who never smoked. Associations were similar by gender, race, type of event (AF and atrial flutter), and when only AF events identified by study exam ECGs were included. Finally, individuals who quit smoking exhibited a trend indicating a slightly lower risk of developing AF (HR 0.88, 95% CI 0.65-1.17) compared to those who continued to smoke.

CONCLUSION

Smoking was associated with the incidence of AF, with more than a two-fold increased risk of AF attributed to current smoking. In addition, a trend toward a lower incidence of AF appeared among smokers who quit compared to continued smokers.

Phenotypic and genotypic methods for the detection of methicillin resistant coagulase negative staphylococci: a comparative study

CONS are the major cause of nosocomial infection in last decade and methicillin resistant CoNS has emerged as a major clinical problem. The present study was to compare different phenotypic methods with genotypic method PCR, for the detection of methicillin resistance in CoNS. 100 CoNS isolates from different samples were studied for the detection of mecA gene. PCR was considered as "gold standard". Oxacillin and cefoxitin antibiotics were used for different phenotypic tests (DD, Agar dilution and MHOX). The sensitivities of oxacillin and cefoxitin disks for all CONS were found to be 92.30% and 88.46% respectively and the specificities were 87.5% and 100% respectively. The sensitivities of the agar dilution test for oxacillin and cefoxitin were 86.53% and 80.76%, respectively, where as the specificities were 79.16% and 85.41%, respectively. The sensitivity of MHOX was observed to be 96.16% and specificity 72.91%. Cefoxitin D.D and oxacillin AD methods could be used as initial test for the determination of methicillin resistance in CoNS isolates. The result of MHOX shows that it could be the best single method for the evaluation of oxacillin resistance mediated by the mecA gene for all CoNS species.

Characterization and In Silico Analysis of Pregnancy-Associated Glycoprotein-1 Gene of Buffalo (Bubalus bubalis)

Pregnancy-Associated Glycoproteins (PAGs) are trophoblastic proteins belonging to the Aspartic proteinase family secreted by different placental cells of many mammalian species. They play a pivotal role in placentogenesis, foetomaternal unit remodeling, and implantation. The identification of the genes encoding those proteins will be helpful to unravel the intricate embryogenomic functions during pregnancy establishment. Considering importance of these proteins, the present study was undertaken to characterize the pregnancy associated glycoprotein-1 gene of buffalo. An 1181 base pairs buffalo Pregnancy-Associated Glycoprotein PAG-1 gene was PCR amplified from the RNA obtained from the fetal cotyledons. BLAST analysis of the buffalo PAG-1 sequence retrieved a total of 20 cattle, 5 goat, and 4 sheep PAG sequences, exhibiting more than 80% similarity. Buffalo PAG-1 gene contained an uninterrupted open reading frame of 1140 base pairs encoding 380 amino acids that possess a 15 amino acid signal peptide and mature peptide of 365 amino acids. The phylogenetic study of the buffalo PAG-1 gene revealed buffalo PAG-1 is more related to cattle, goat, and sheep PAG-1 sequences. By this study characterization of buffalo PAG-1 gene and its evolutionary relationship was deduced for the first time.

Correlates of hypertension among urban Asian Indian adolescents

OBJECTIVE

Primary hypertension has become increasingly common in children but remains largely understudied, underdiagnosed and undertreated. This study examines the relationship between hypertension in adolescents and various markers of obesity, serum lipid levels, fasting blood glucose (FBG), haemoglobin A1c (HbA1c) and family history of hypertension. DESIGN/SETTINGS: A cross-sectional population-based study of 1022 students aged 14-19 years in New Delhi, India. MAIN OUTCOME/EXPOSURES: Those with age, gender and height specific blood pressure >95th percentile (derived from study data) or >130/85 mm&emsp14;Hg were considered hypertensive. Various markers of obesity, FBG, HbA1c and serum lipid levels were divided into quartiles and the odds ratios of hypertension calculated for the highest quartiles with reference to the lowest.

RESULTS

Hypertension was seen in 65 (6.4%) adolescents (2.7% isolated systolic, 2.0% isolated diastolic and 1.7% both). The odds of having hypertension were higher for those in the highest versus lowest quartiles of various measures of obesity such as body mass index (OR 2.90; 95% CI 1.40 to 6.12) and waist circumference (OR 5.21; 95% CI 2.14 to 12.17). A parental history of hypertension was associated with diastolic hypertension in the child (OR 2.21; 95% CI 1.13 to 4.33); the odds ratio decreased after simultaneous adjustment for salt intake (OR 1.98; 95% CI 1.00 to 3.94). In a multivariable model with backward elimination, waist circumference and triglycerides were the strongest predictors of hypertension, further suggesting that the relationship is stronger with central than peripheral obesity.

CONCLUSION

Hypertension in Asian Indian adolescents is associated with obesity, higher serum lipids and a family history of hypertension.

Hemodialysis of patients with HCV infection: isolation has a definite role

HCV infection in patients on hemodialysis varies from 10 to 60% in various centers. There is controversy regarding the isolation of patients with HCV infection during hemodialysis. Guidelines developed by the Centers for Disease Control and Prevention do not suggest isolation of these patients. In this opposite view, evidence is being given to support the view that there is a definite role of isolation of HCV-infected patients during hemodialysis.

Perceived weight status, overweight diagnosis, and weight control among US adults: the NHANES 2003-2008 Study

OBJECTIVES

To examine the association between perceived overweight status and weight control, discrepancies between perceived and measured weight status, and opportunities for health care professionals (HCPs) to correct weight perception among US adults.

DESIGN

Population-based cross-sectional study.

SUBJECTS

In all, 16,720 non-pregnant adults from the 2003 to 2008 National Health and Nutrition Examination Survey.

RESULTS

Overall, 64% (73% women, 55% men) reported a desire to weigh less and 48% (57% women, 40% men) reported pursuing weight control. Weight control was positively associated with overweight perception (odds ratio (OR) women 3.74; 95% confidence interval (CI) 2.96, 4.73; OR men 2.82; 95% CI 2.11, 3.76) and an HCP diagnosis of overweight/obesity (OR women 2.22; 95% CI 1.69, 2.91; OR men 2.14; 95% CI 1.58, 2.91), independent of measured weight status. A large proportion of overweight individuals (23% women, 48% men) perceived themselves as having the right weight. Also, 74% of overweight and 29% of obese individuals never had an HCP diagnosis of overweight/obesity. Although the majority of overweight/obese individuals (74% women, 60% men) pursued at least one weight management strategy, fewer (39% women, 32% men) pursued both dietary change and physical activity. Among overweight/obese adults, those with an HCP diagnosis of overweight/obesity were more likely to diet (74 versus 52%), exercise (44 versus 34%), or pursue both (41 versus 30%, all P<0.01) than those who remained undiagnosed.

CONCLUSION

HCPs have unused opportunities to motivate their patients to control and possibly lose weight by correcting weight perceptions and offering counseling on healthy weight loss strategies.

Hemostatic markers are associated with the risk and prognosis of atrial fibrillation: the ARIC study

BACKGROUND

Various hemostatic markers are associated with the risk of cardiovascular disease; however, limited information exists on their relationship with the occurrence and prognosis of atrial fibrillation (AF).

OBJECTIVES

To assess whether hemostatic markers are associated with the incidence and prognosis of AF.

METHODS

We studied 14,858 men and women in the Atherosclerosis Risk in Communities cohort, aged 45-64 and free of AF at baseline (1987-1989). Fibrinogen, von Willebrand factor (vWf), factor VII activity (VIIc), factor VIII activity (VIIIc), protein C, antithrombin III (ATIII), and activated partial thromboplastin time (aPTT) were measured in blood samples at baseline. AF and other cardiovascular outcomes through 2005 were determined following standardized protocols.

RESULTS

During a median follow-up of 16.8 years, 1209 cases of AF were identified. In multivariable Cox models, the hazard ratios (HR) and 95% confidence intervals (CI) of incident AF associated with a 1-standard deviation (SD) increase in each marker were 1.13 (1.07-1.20) for fibrinogen, 1.17 (1.11-1.23) for vWf, 1.17 (1.11-1.24) for factor VIIIc, 0.93 (0.88-1.00) for factor VIIc, 0.98 (0.92-1.04) for protein C, 1.00 (0.94-1.06) for aPTT and 1.00 (0.95-1.06) for ATIII. Greater factor VIIIc, fibrinogen and vWf were consistently associated with a higher risk of cardiovascular outcomes and mortality in those with and without incident AF, while greater protein C was associated with a lower risk of ischemic stroke.

CONCLUSION

Several hemostatic markers are associated with the incidence of AF independently of other cardiovascular risk factors. Their role in the risk stratification of AF patients should be further studied.

Evaluation of cognitive function and P300 in patients undergoing cardiac surgery

OBJECTIVE

This study reports cognitive, P300 and MRI changes in the patients undergoing open heart surgery.

DESIGN

18 patients undergoing open heart surgery were included who were aged > or = 18 years of age and educated at least up to 5th standard. Patients with preoperative neuropsychiatric, and metabolic illnesses were excluded. The operative and post operative events wer recorded Cognitive tests included Mini Mental State examination (MMSE), forward and backward digit span, trail making test (TMT), motor speed and precision test (MSPT), Luria's 3 step, Benton visual retention test (BVRT) and hospital anxiety and depression (HAD). P300 study was carried out using auditory oddball paradigm and recording from Cz, Fz and Pz referred to mastoids. Clinical psychometry, MRI and P300 studies were repeated after 6 weeks.

RESULTS

The median age of the patients was 51 years and 7 were females. Coronary artery bypass graft (15) was done off pump and valve replacement (7) and atrial septal defect (2) were done on pump. Clinical psychometric tests did not change significantly after surgery except BVRT and MSPT were improved significantly after the surgery. The pre and post surgical P300 latency and amplitude were also not different. Follow up MRI in 10 patients also did not reveal any additional findings.

CONCLUSION

Cognitive decline was not observed after open heart surgery as assessed by clinical psychometry and P300 studies.

Massive pulmonary embolism and acute limb ischaemia in a patient of hereditary spherocytosis and patent foramen ovale

Paradoxical embolism accounts for 2% of patients who present with acute arterial embolism of extremities. We report a case of a 41 year-old male with hereditary spherocytosis who presented to the emergency department with acute limb ischaemia and pulmonary embolism. On further evaluation, he was found to have patent foramen ovale (PFO) and deep vein thrombosis (DVT), leading to paradoxical embolism. The purpose of this report is to emphasise that in a patient presenting with acute limb ischaemia without an obvious systemic arterial embolic source, an evaluation for a right-to-left shunting lesion, especially PFO, should be performed.

Methylosinus trichosporium OB3b Mutants Having Constitutive Expression of Soluble Methane Monooxygenase in the Presence of High Levels of Copper

The methanotrophic bacterium Methylosinus trichosporium OB3b is unusually active in degrading recalcitrant haloalkanes such as trichloroethylene (TCE). The first and rate-limiting step in the degradation of TCE is catalyzed by a soluble methane monooxygenase (sMMO). This enzyme is not expressed when the cells are grown in the presence of copper at concentrations typically found in polluted groundwater. Under these conditions, M. trichosporium OB3b expresses a particulate form of the enzyme (pMMO), which has a narrow substrate specificity and does not degrade TCE at any significant rate. We have isolated M. trichosporium OB3b mutants that are deficient in pMMO and express sMMO constitutively in the presence of elevated concentrations of copper. One mutant (PP358) exhibited a TCE degradation rate which was almost twice as high as that of the wild-type strain grown under optimal conditions (without copper). All of the mutants lost the ability to express pMMO activity and to form stacked intracellular membranes characteristic of wild-type cells expressing pMMO.

Nephrogenic systemic fibrosis: UK survey of the use of gadolinium-based contrast media

AIM

To identify the current practice of administration of gadolinium-based contrast media (Gd-CM) within the UK with respect to the European Society of Urogenital Radiology (ESUR) guidelines on nephrogenic systemic fibrosis (NSF).

MATERIALS AND METHODS

One hundred and fifty-two institutions were contacted to request details regarding the use of Gd-CM at their institution, their awareness of NSF, and of the ESUR guidelines, and their departmental policy on the administration of Gd-CM agents associated with NSF (high-risk agents) in patients with diminished renal function.

RESULTS

Of the 100 institutions that replied, 72% used a cyclic agent as a first-line Gd-CM. The majority of institutions used more than one Gd-CM, and 57% used a high-risk Gd-CM. Seventy percent were aware of the ESUR guidelines, and of the 57% that used a high-risk Gd-CM, 9% did not check renal function at all prior to administration. The course of action of the remaining 48% was varied in patients with diminished renal function with some changing to a low-risk Gd-CM and others electing not to use Gd-CM at all. Five percent continued to use a high-risk Gd-CM with an estimated glomerular filtration rate <30ml/min.

CONCLUSION

The present survey shows that the majority of institutions use a low-risk Gd-CM as a first-line agent; however, a number of institutions do use a high-risk Gd-CM and their course of action for patients with diminished renal function is varied. Given current evidence, it is advisable to use a low-risk Gd-CM, such as a cyclic agent, in patients with diminished renal function.