The association of uterine cervical microbiota with an increased risk for cervical intraepithelial neoplasia in Korea

Recent studies have suggested potential roles of the microbiome in cervicovaginal diseases. However, there has been no report on the cervical microbiome in cervical intraepithelial neoplasia (CIN). We aimed to identify the cervical microbiota of Korean women and assess the association between the cervical microbiota and CIN, and to determine the combined effect of the microbiota and human papillomavirus (HPV) on the risk of CIN. The cervical microbiota of 70 women with CIN and 50 control women was analysed using pyrosequencing based on the 16S rRNA gene. The associations between specific microbial patterns or abundance of specific microbiota and CIN risk were assessed using multivariate logistic regression, and the relative excess risk due to interaction (RERI) and the synergy index (S) were calculated. The phyla Firmicutes, Actinobacteria, Bacteroidetes, Proteobacteria, Tenericutes, Fusobacteria and TM7 were predominant in the microbiota and four distinct community types were observed in all women. A high score of the pattern characterized by predominance of Atopobium vaginae, Gardnerella vaginalis and Lactobacillus iners with a minority of Lactobacillus crispatus had a higher CIN risk (OR 5.80, 95% CI 1.73-19.4) and abundance of A. vaginae had a higher CIN risk (OR 6.63, 95% CI 1.61-27.2). The synergistic effect of a high score of this microbial pattern and oncogenic HPV was observed (OR 34.1, 95% CI 4.95-284.5; RERI/S, 15.9/1.93). A predominance of A. vaginae, G. vaginalis and L. iners with a concomitant paucity of L. crispatus in the cervical microbiota was associated with CIN risk, suggesting that bacterial dysbiosis and its combination with oncogenic HPV may be a risk factor for cervical neoplasia.

Genetic analysis of Nicotiana pollen-part mutants is consistent with the presence of an S-ribonuclease inhibitor at the S locus

Self-incompatibility (SI) is a genetic mechanism that restricts inbreeding in flowering plants. In the nightshade family (Solanaceae) SI is controlled by a single multiallelic S locus. Pollen rejection in this system requires the interaction of two S locus products: a stylar (S)-RNase and its pollen counterpart (pollen S). pollen S has not yet been cloned. Our understanding of how this gene functions comes from studies of plants with mutations that affect the pollen but not the stylar SI response (pollen-part mutations). These mutations are frequently associated with duplicated S alleles, but the absence of an obvious additional allele in some plants suggests pollen S can also be deleted. We studied Nicotiana alata plants with an additional S allele and show that duplication causes a pollen-part mutation in several different genetic backgrounds. Inheritance of the duplication was consistent with a competitive interaction model in which any two nonmatching S alleles cause a breakdown of SI when present in the same pollen grain. We also examined plants with presumed deletions of pollen S and found that they instead have duplications that included pollen S but not the S-RNase gene. This finding is consistent with a bipartite structure for the S locus. The absence of pollen S deletions in this study and perhaps other studies suggests that pollen S might be required for pollen viability, possibly because its product acts as an S-RNase inhibitor.

Serum uric acid is associated with microalbuminuria in prehypertension

Serum uric acid is associated with cardiovascular disease. However, the independent role of uric acid in the development of cardiovascular disease is uncertain. This study examined the cross-sectional association of serum uric acid level with microalbuminuria among 6771 subjects without diabetes or hypertension. Blood pressure was categorized as prehypertension (systolic blood pressure, 120 to 140 mm Hg or diastolic blood pressure, 80 to 90 mm Hg) and normotension (systolic blood pressure, <120 mm Hg and diastolic blood pressure, <80 mm Hg). Microalbuminuria was found in 4.0% of normotensive subjects (n=4819) and in 7.9% of prehypertensive subjects (n=1952). Prehypertensive subjects with microalbuminuria had higher uric acid level than those with normoalbuminuria (men, 387 [68] mmol/L versus 371 [69] mmol/L; P=0.017; women 286 [56] mmol/L versus 262 [54] mmol/L; P=0.006). However, the difference in serum uric acid level according to the presence or absence of microalbuminuria was not found in the normotensive group. Multiple logistic regression models showed that, in the prehypertensive group, after adjustment for other cardiovascular risk factors, the highest uric acid quartile entailed >2 times greater risk for microalbuminuria than the lowest quartile in both men (odds ratio, 2.12; 95% CI, 1.16 to 3.87) and women (odds ratio, 3.36; 95% CI, 1.17 to 9.69). In the normotensive group, serum uric acid quartile did not show the independent association with microalbuminuria. In conclusion, serum uric acid level was strongly associated with microalbuminuria in prehypertensive subjects.

Predictors of acute kidney injury associated with intravenous colistin treatment

Colistimethate sodium (CMS) was recently re-introduced into clinical practice as a last resort for the treatment of nosocomial infections caused by multiresistant bacteria. This retrospective cohort study was designed to identify predictors of acute kidney injury (AKI) associated with intravenous (i.v.) CMS treatment. From March 2007 to July 2008, 71 adult patients receiving CMS for > or = 72h were enrolled. AKI was defined using Risk, Injury, Failure, Loss and End-stage kidney disease (RIFLE) criteria according to serum creatinine. The median total dose of CMS was 54.3mg/kg (range 27.5-94.5mg/kg). AKI developed in 38 patients (53.5%). Cox regression analysis based of cumulative CMS dose (mg/kg) identified four independent predictors of AKI: male sex [hazard ratio (HR)=3.55, 95% confidence interval (CI), 1.47-8.55]; concomitant use of a calcineurin inhibitor (HR=6.74, 95% CI 2.49-18.24); hypoalbuminaemia (serum albumin level <2.0g/dL) (HR=6.29, 95% CI 2.04-19.39); and hyperbilirubinaemia (total bilirubin level >5mg/dL) (HR=3.53, 95% CI 1.17-10.71). In conclusion, AKI was a common complication of i.v. CMS treatment. Male sex, concomitant use of calcineurin inhibitors, hypoalbuminaemia and hyperbilirubinaemia were independent predictors of AKI. The effect of AKI on patient outcomes was not determined.

Post-operative acute kidney injury in patients with renal cell carcinoma is a potent risk factor for new-onset chronic kidney disease after radical nephrectomy

BACKGROUND

Radical nephrectomy is a significant risk factor for chronic kidney disease (CKD). There are few reports on the renal outcome of acute kidney injury (AKI) after radical nephrectomy. The aim of this study was to determine the incidence of AKI and whether post-operative AKI is associated with new-onset CKD after radical nephrectomy for renal cell cancer (RCC).

METHODS

We conducted a retrospective study of 519 adult patients (>40 years old) with normal renal function who underwent unilateral radical nephrectomy for a solitary renal cortical tumour and were pathologically diagnosed with RCC between January 2000 and February 2007. Post-operative AKI was classed using risk, injury, failure, loss and end-stage kidney disease (RIFLE) criteria. CKD was defined as a decrease in estimated glomerular filtration rate (GFR) to <60 mL/min/1.73 m(2).

RESULTS

According to the RIFLE criteria, 165 of 175 patients fell into the AKI risk category, 8 patients fell into the AKI injury category and 2 patients fell into the AKI failure category. Multivariate analysis revealed that older age [odds ratio (OR) 1.02, 95% confidence interval (CI) 1.00-1.05], male gender (OR 3.13, 95% CI 1.91-5.12), higher body mass index (OR 1.08, 95% CI 1.01-1.15), smaller RCC size (OR 0.87, 95% CI 0.81-0.93) and higher preoperative GFR (OR 1.04, 95% CI 1.03-1.06) were independent risk factors for post-operative AKI. CKD was more prevalent in the AKI risk group than in patients without AKI 1 year after surgery (54.7% versus 43.9%, respectively; P = 0.006) and 3 years after surgery (50% versus 32%, respectively; P = 0.003). Patients who experienced post-operative AKI had a 4.24-fold higher risk of new-onset CKD after multiple adjustments were made to the data (95% CI 2.28-7.89, P < 0.001).

CONCLUSION

AKI after radical nephrectomy in patients with RCC is a potent risk factor for new-onset CKD. Prevention of post-operative AKI is essential for reducing the incidence of CKD after nephrectomy.

Incidence and clinical significance of human parvovirus B19 infection in kidney transplant recipients

Human parvovirus B19 (B19) infection has been known to cause chronic anemia, pure red cell aplasia (PRCA), glomerulopathy, and allograft dysfunction in kidney transplant (KT) recipients. The aim of this study was to evaluate the incidence and clinical significance of B19 infection in KT recipients. A total of 537 serum samples from 167 KT recipients were included in the present study. The incidence of B19 infection was based on either qualitative polymerase chain reaction (PCR) or quantitative PCR with LightCycler Parvovirus B19 Quantitation kit. Clinical significance of B19 infection was investigated by a retrospective review of hemoglobin (Hb) levels and the results of kidney and bone marrow biopsies. The overall PCR positive rate was 18.3% (98/537), and 52 of 167 (31.1%) KT recipients showed at least one positive PCR. In addition, 20 of 167 subjects (12.0%) showed PCR-positivity more than two consecutive times, and they had significantly lower Hb levels than those with negative or one positive PCR (p < 0.0001). Furthermore, two patients suffered from PRCA, which was confirmed by bone marrow biopsy. However, B19 infection did not seem to affect the graft outcome. In conclusion, the B19 infection in KT recipients was not uncommon and was associated with low Hb levels and PRCA after KT.

The impact of early and late acute rejection on graft survival in renal transplantation

Background

Advances in immunosuppression after kidney transplantation have decreased the influence of early acute rejection (EAR) on graft survival. Several studies have suggested that late acute rejection (LAR) has a poorer effect on long-term graft survival than EAR. We investigated whether the timing of acute rejection (AR) influences graft survival, and analyzed the risk factors for EAR and LAR.

Methods

We performed a retrospective cohort study involving 709 patients who underwent kidney transplantation between 2000 and 2009 at the Samsung Medical Center, Seoul, Korea. Patients were divided into three groups: no AR, EAR, and LAR. EAR and LAR were defined as rejection before 1 year and after 1 year, respectively. Differences in graft survival between the three groups and risk factors of graft failure were analyzed.

Results

Of the 709 patients, 198 (30%) had biopsy-proven AR [EAR=152 patients (77%); LAR=46 patients (23%)]. A total of 65 transplants were lost. The 5-year graft survival rates were 97%, 89%, and 85% for patients with no AR, EAR, and LAR, respectively. These differences were significant (P<0.001 for both by log-rank test). In time-dependent Cox regression analysis, EAR (hazards ratio, 3.37; 95% confidence interval, 1.90–5.99) and LAR (hazards ratio, 5.32; 95% confidence interval, 2.65–10.69) were significantly related to graft failure. When we set LAR as standard and compared it with EAR, there was no statistical difference between EAR and LAR (P=0.21).

Conclusion

AR, regardless of its timing, significantly worsened graft survival. Treatments to reduce the incidence of AR and improve prognosis are needed.

Increased risk of acute kidney injury associated with higher infusion rate of mannitol in patients with intracranial hemorrhage

Object

Mannitol, an osmotic agent used to decrease intracranial pressure, can cause acute kidney injury (AKI). The objectives of this study were to assess the impact of mannitol on the incidence and severity of AKI and to identify risk factors and outcome for AKI in patients with intracranial hemorrhage (ICH).

Methods

The authors retrospectively evaluated 153 adult patients who received mannitol infusion after ICH between January 2005 and December 2009 in the neurosurgical intensive care unit. Multivariate analysis was used to evaluate the risk factors for AKI after ICH. Based on the odds ratio, weighted scores were assigned to predictors of AKI.

Results

The overall incidence of AKI among study participants was 10.5% (n = 16). Acute kidney injury occurred more frequently in patients who received mannitol infusion at a rate ≥ 1.34 g/kg/day than it did in patients who received mannitol infusion at a rate < 1.34 g/kg/day. A higher mannitol infusion rate was associated with more severe AKI. Independent risk factors for AKI were mannitol infusion rate ≥ 1.34 g/kg/day, age ≥ 70 years, diastolic blood pressure (DBP) ≥ 110 mm Hg, and glomerular filtration rate < 60 ml/min/1.73 m2. The authors developed a risk model for AKI, wherein patients with a higher risk score showed a graded association with a higher incidence of AKI.

Conclusions

The incidence of AKI following mannitol infusion in patients with ICH was 10.5%. A higher mannitol infusion rate was associated with more frequent and more severe AKI. Additionally, age ≥ 70 years, DBP ≥ 110 mm Hg, and established renal dysfunction before starting mannitol therapy were associated with development of AKI.

Medullary nephrocalcinosis associated with long-term furosemide abuse in adults

BACKGROUND

The use of furosemide is well recognized as a predisposing factor of nephrocalcinosis in infants. Although furosemide is widely used for various medical conditions in adults, its association with nephrocalcinosis in adults is not well established.

METHODS

We studied 18 consecutive adult patients (male:female ratio 1:17, age range 21-59 years) who habitually took furosemide to control weight or oedema for long periods of time (range 3-25 years). The daily dose of continuous intake of furosemide ranged from 40 to 2800 mg. Nephrocalcinosis was evaluated using renal ultrasonography (US), computed tomography (CT), or kidney biopsies.

RESULTS

Renal US and CT revealed bilateral nephrocalcinosis of the medullary pyramids in 15 (83.3%) out of 18 patients. The duration of furosemide abuse was similar between nephrocalcinosis positive (NC(+)) and nephrocalcinosis negative (NC(-)) groups. The daily dose of furosemide was nearly 10 times higher in the NC(+) group (range 120-2800 mg, mean 538 mg) than the NC(-) group (range 40-80 mg, mean 67 mg). All patients showed variable degrees of renal insufficiency and there was no difference in creatinine clearance between the NC(+) and NC(-) groups (P>0.05). Kidney biopsies performed in three patients showed focal tubulo-interstitial fibrosis and atrophy and calcifications were observed in outer medullary tubulo-interstitium.

CONCLUSIONS

Long-term furosemide abuse can cause medullary nephrocalcinosis in adults, and the risk of developing of nephrocalcinosis seems to be correlated with the daily dose of furosemide. We suggest that long-term furosemide abuse should be suspected in adult patients when medullary nephrocalcinosis is incidentally detected by US or CT.

Assessment of extent of breast cancer: comparison between digital breast tomosynthesis and full-field digital mammography

AIM

To compare the accuracy of digital breast tomosynthesis (DBT) and full-field digital mammography (FFDM) in preoperative assessment of local extent of breast cancer.

MATERIALS AND METHODS

Lesion sizes of breast cancers on DBT and FFDM images were independently evaluated by breast radiologists. Each lesion was flagged as either mis-sized or not depending on whether the assessment of size at imaging was within 1 cm of the lesion size at surgery. Additional analyses were made by mammographic parenchymal density and by lesion size, using 2 cm as the boundary to separate the two subgroups. Statistical comparisons were performed using a repeated measures linear model on the percent mis-sized. P-values < 0.05 were considered statistically significant.

RESULTS

The dataset included 173 malignant breast lesions (mean size 23.8 mm, 43% of lesions were ≤2 cm in size) in 169 patients, two-thirds of which had heterogeneously or extremely dense breasts. Overall, the percentage of lesions mis-sized at DBT was significantly lower than at FFDM (19% versus 29%, p = 0.003). There was significantly less mis-sizing at DBT in both heterogeneously dense breasts (11.1% difference between DBT and FFDM, p = 0.016) and extremely dense breasts (15.8% difference, p = 0.024). DBT also had significantly less mis-sizing than FFDM in the subgroup of lesions that were ≤2 cm in size (14.7% difference, p = 0.005).

CONCLUSION

DBT was significantly superior to FFDM for the evaluation of lesion size overall, and specifically for small lesions and for lesions in dense breasts. The superiority of DBT versus FFDM increased with parenchymal density.

Unilateral renal cystic disease in adults

Unilateral renal cystic disease (URCD) is morphologically indistinguishable from autosomal dominant polycystic kidney disease (ADPKD) except for its unilaterality. Unlike ADPKD, URCD patients show neither a genetic background nor progressive deterioration in renal function; thus, the differential diagnosis of URCD from ADPKD is important. Only a few cases of URCD have been reported. This study reports two cases of URCD in adults together with a literature review. We identified these two cases using abdominal computerized tomography and family screening with renal ultrasonography.

Effect of preemptive treatment with human umbilical cord blood-derived mesenchymal stem cells on the development of renal ischemia-reperfusion injury in mice

Human umbilical cord blood-derived mesenchymal stem cells (HUCB-MSCs) have been studied in several models of immune-mediated disease because of their unique immunomodulatory properties. We hypothesized that HUCB-MSCs could suppress the inflammatory response in postischemic kidneys and attenuate early renal injury. In 8- to 10-wk-old male C57BL/6 mice, bilateral ischemia-reperfusion injury (IRI) surgery was performed, and 1 × 10(6) HUCB-MSCs were injected intraperitoneally 24 h before surgery and during reperfusion. Renal functional and histological changes, HUCB-MSC trafficking, leukocyte infiltration, and cytokine expression were analyzed. Renal functional decline and tubular injury after IRI were attenuated by HUCB-MSC treatment. PKH-26-labeled HUCB-MSCs trafficked into the postischemic kidney. Although numbers of CD45-positive leukocytes in the postischemic kidney were comparable between groups, the expression of interferon-γ in the postischemic kidney was suppressed by HUCB-MSC treatment. The rapid decrease in intrarenal VEGF after IRI was markedly mitigated by HUCB-MSC treatment. In inflammatory conditions simulated in a cell culture experiment, VEGF secretion from HUCB-MSCs was substantially enhanced. VEGF inhibitor abolished the renoprotective effect of HUCB-MSCs after IRI. Flow cytometry analysis revealed the decreased infiltration of natural killer T cells and increased number of regulatory T cells in postischemic kidneys. In addition, these effects of HUCB-MSCs on kidney infiltrating mononuclear cells after IRI were attenuated by VEGF inhibitor. HUCB-MSCs attenuated renal injury in mice in the early injury phase after IRI, mainly by humoral effects and secretion of VEGF. Our results suggest a promising role for HUCB-MSCs in the treatment of renal IRI.

Higher mitochondrial DNA copy number is associated with lower prevalence of microalbuminuria

It has been suggested that mitochondrial dysfunction contributes to the initiation and development of atherosclerosis and cardiovascular disease. We examined the association between mitochondrial DNA (mtDNA) copy number and microalbuminuria in a cross-sectional community-based study. We measured peripheral blood mtDNA copy number in 694 adults without chronic kidney disease by a real-time PCR method. The overall prevalence of microalbuminuria (defined as an albumin creatinine ratio of 30 to 299 mg/g) was 4.5%. The prevalence of microalbuminuria decreased progressively from the lower to the upper quartiles of mtDNA copy number (6.9%, 5.7%, 2.9%, and 2.3% in quartiles 1, 2, 3, and 4, respectively, P=0.017 for trend). Multiple logistic regression models showed that the quartile of mtDNA copy number was independently associated with the prevalence of microalbuminuria (P=0.01 for trend). Compared with the lowest quartile, the highest quartile had an odds ratio of 0.22 for microalbuminuria (95% confidence interval, 0.05 to 0.87; P=0.03). Higher mtDNA copy number was associated with the lower prevalence of microalbuminuria in a community-based population.

Association between diuretics and successful discontinuation of continuous renal replacement therapy in critically ill patients with acute kidney injury

BACKGROUND

Despite aggressive application of continuous renal replacement therapy (CRRT) in critically ill patients with acute kidney injury (AKI), there is no consensus on diuretic therapy when discontinuation of CRRT is attempted. The effect of diuretics on discontinuation of CRRT in critically ill patients was evaluated.

METHODS

This retrospective cohort study enrolled 1176 adult patients who survived for more than 3 days after discontinuing CRRT between 2009 and 2014. Patients were categorized depending on the re-initiation of renal replacement therapy within 3 days after discontinuing CRRT or use of diuretics. Changes in urine output (UO) and renal function after discontinuing CRRT were outcomes. Predictive factors for successful discontinuation of CRRT were also analyzed.

RESULTS

The CRRT discontinuation group had a shorter duration of CRRT, more frequent use of diuretics after discontinuing CRRT, and greater UO on the day before CRRT discontinuation [day minus 1 (day - 1)]. The diuretics group had greater increases in UO and serum creatinine elevation after discontinuing CRRT. In the CRRT discontinuation group, continuous infusion of furosemide tended to increase UO more effectively. Multivariable regression analysis identified high day - 1 UO and use of diuretics as significant predictors of successful discontinuation of CRRT. Day - 1 UO of 125 mL/day was the cutoff value for predicting successful discontinuation of CRRT in oliguric patients treated with diuretics following CRRT.

CONCLUSIONS

Day - 1 UO and aggressive diuretic therapy were associated with successful CRRT discontinuation. Diuretic therapy may be helpful when attempting CRRT discontinuation in critically ill patients with AKI, by inducing a favorable fluid balance, especially in oliguric patients.

Tissue expression of tubular injury markers is associated with renal function decline in diabetic nephropathy

AIMS

The pathogenesis of diabetic kidney disease (DKD) is complex and multifactorial; increasing evidence suggests that tubular injury and inflammatory process are involved in disease progression. We investigated the potential association of renal expression of tubular injury markers, neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and inflammatory markers, tumor necrosis factor receptor (TNFR) 1 and 2 with renal progression in pathologically proven diabetic nephropathy (DN).

METHODS

We identified 122 patients with confirmed DN. After excluding patients with other coexisting renal disease or estimated glomerular filtration rate (eGFR) <30mL/min/1.73m², 35 patients were included. Annual decline of (GFR decline slope) was calculated using linear regression analysis. Tissue tubular and glomerular expressions of NGAL, KIM-1, TNFR1, and TNFR2 were assessed using immunohistochemistry.

RESULTS

Median baseline urinary protein to creatinine ratio (uPCR) was 6.76 (2.18-7.61) mg/mg Cr, median baseline eGFR was 50 (43-66) mL/min per 1.73m², and median GFR decline slope was 15.6 (4.4-35.1) mL/min per 1.73m² per year. Positive correlations were observed between tubular expressions of NGAL and KIM-1, and GFR decline slopes (r=0.601, p<0.001; r=0.516, p=0.001, respectively), and between tubular expressions of KIM-1 and uPCR (r=0.596, p<0.001), and between NGAL and interstitial fibrosis and tubular atrophy (IFTA) score (r=0.391, p=0.024). No correlations were found between glomerular or tubular expressions of TNFRs, and clinical parameters including GFR decline slopes. On multivariate analysis, the association between tubular expressions of KIM-1 and GFR decline slopes was dependent on uPCR. Tubular expressions of NGAL were independently associated with GFR decline slopes, with an adjusted coefficient factor of 0.290 (95% confidence interval, 0.009-0.202, p=0.038).

CONCLUSIONS

These findings suggest that tubular injury plays a key role in the pathogenesis of DKD in high-risk patients. Further studies are warranted to determine whether tubular injury could be a therapeutic target in DKD.

Verapamil prevents chronic renal failure-induced abnormalities in lipid metabolism

Hypertriglyceridemia is common in chronic renal failure (CRF); this derangement is due to decreased peripheral removal of triglycerides. Certain data indicate that the state of secondary hyperparathyroidism of CRF is, at least in part, responsible for derangements in lipid metabolism. It has been proposed that chronic excess of parathyroid hormone exerts its deleterious effects on many organs through its ability to raise basal levels of cytosolic calcium. Prevention of the latter by a calcium channel blocker is followed by the correction of organ dysfunctions. The present study examined the effect of treatment of CRF rats with verapamil on several parameters of lipid metabolism. Chronic renal failure rats displayed hypertriglyceridemia, fat intolerance, reduced postheparin plasma lipoprotein and hepatic lipase activities, decreased hepatic lipase in liver homogenate, and elevated calcium content in liver and epididymal fat. Treatment of the CRF rats with verapamil prevented all these derangements in lipid metabolism. These effects of verapamil were similar to those produced by parathyroidectomy of CRF rats. The data are consistent with the formulation that chronic excess of parathyroid hormone increases the calcium burden of liver and adipose tissue and consequently impairs the synthesis and/or release of lipoprotein and hepatic lipases. Reduced availability of these enzymes in plasma results in impared peripheral removal of triglycerides, leading to hypertriglyceridemia.

Variant metabolizing gene alleles determine the genotoxicity of benzo[a]pyrene

Understanding the mechanisms involved with genetic susceptibility to environmental disease is of major interest to the scientific community. We have conducted an in vitro study to elucidate the involvement of polymorphic metabolizing genes on the genotoxicity of benzo[a]pyrene (BP). Blood samples from 38 donors were treated with BP and the induction of sister chromatid exchanges (SCE) and chromosome aberrations (CA) were evaluated. The latter is based on the tandem-probe fluorescence in situ hybridization (FISH) assay. The data indicate that the induction of genotoxicity was clearly determined by the inherited variant genotypes for glutathione-S-transferase (GSTM1) and microsomal epoxide hydrolase (EH). In a comparison of the two biomarkers, the CA biomarker shows a more definite association with the genotypes than does SCE. For example, the presence of the GSTM1 null genotype (GSTM1 0/0) is responsible for the highest level and significant induction of CA, irrespective of the presence of other genotypes in the different donors. This effect is further enhanced significantly by the presence of the excessive activation EH gene allele (EH4*) and decreased by the reduced activation EH gene allele (EH3*). Overall, the modulation of genotoxicity by the susceptibility genotypes provides support of their potential involvement in environmental cancer. Furthermore, the data indicate that the variant enzymes function independently by contributing their metabolic capability toward the expression of biologic activities. Therefore, studies like this one can be used to resolve the complexity of genetic susceptibility to environmental disease in human.

Association between changes in N-terminal pro-brain natriuretic peptide levels and changes in left ventricular mass index in stable hemodialysis patients

BACKGROUND/AIMS

Left ventricular (LV) hypertrophy is a powerful predictor of mortality in dialysis patients. Serial measurements of LV mass provide prognostic information. We evaluated the association between changes in biomarkers and changes in LV mass index (LVMI) in hemodialysis (HD) patients.

METHODS

This was a prospective study of 21 stable HD patients with preserved LV ejection fraction (> or =50%). Echocardiography and measurements of N-terminal pro-brain natriuretic peptide (NT-proBNP), brain natriuretic peptide (BNP) and cardiac troponin T were performed on the same day and repeated 6 and 12 months later.

RESULTS

At baseline, the NT-proBNP and BNP levels correlated with LVMI. Percent changes in LVMI were positively associated with those in log-transformed NT-proBNP levels during both the first (baseline vs. month 6, r = 0.78, p < 0.001) and the second 6 months (months 6 vs. 12, r = 0.73, p < 0.001). Among the 3 biomarkers, NT-proBNP was the only one that was related to changes in LVMI by multivariate correlation analysis, including age, sex, blood pressure, predialysis weight and use of angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker.

CONCLUSION

Our results show that changes in LVMI are closely correlated with variation in NT-proBNP levels in HD patients. These data have significant implications for the application of NT-proBNP as a biomarker for assessing changes in LVMI in HD patients.

Early, but not late, treatment with human umbilical cord blood-derived mesenchymal stem cells attenuates cisplatin nephrotoxicity through immunomodulation

Preemptive treatment with mesenchymal stem cells (MSCs) can attenuate cisplatin-induced acute kidney injury (AKI). However, it is uncertain whether MSC treatment after the development of renal dysfunction prevents AKI progression or if MSC immunomodulatory properties contribute to MSC therapy. In this study, human umbilical cord blood (hUCB)-derived MSCs were used to compare the effects and mechanisms of early and late MSC therapy in a murine model. After cisplatin injection into C57BL/6 mice, hUCB-MSCs were administered on day 1 (early treatment) or day 3 (late treatment). With early treatment, cisplatin nephrotoxicity was attenuated as evidenced by decreased blood urea nitrogen (BUN) and reduced apoptosis and tubular injury scores on day 3 Early treatment resulted in downregulation of intrarenal monocyte chemotactic protein-1 and IL-6 expression and upregulation of IL-10 and VEGF expression. Flow cytometric analysis showed similar populations of infiltrated immune cells in both groups; however, regulatory T-cell (Treg) infiltration was 2.5-fold higher in the early treatment group. The role of Tregs was confirmed by the blunted effect of early treatment on renal injury after Treg depletion. In contrast, late treatment (at a time when BUN levels were 2-fold higher than baseline levels) showed no renoprotective effects on day 6 Neither the populations of intrarenal infiltrating immune cells (including Tregs) nor cytokine expression levels were affected by late treatment. Our results suggest that early MSC treatment attenuates renal injury by Treg induction and immunomodulation, whereas a late treatment (i.e., after the development of renal dysfunction) does not prevent AKI progression or alter the intrarenal inflammatory micromilieu.

The origin and the clinical significance of urinary angiotensinogen in proteinuric IgA nephropathy patients

BACKGROUND

Urinary angiotensinogen (AGT) was reported as a marker of renal injury in chronic kidney disease patients. However, the main source of urinary AGT is unknown in proteinuric patients because the disrupted filtration barrier might cause AGT filtration. We investigated the origin and the clinical importance of urinary AGT in proteinuric IgA nephropathy (IgAN) patients.

METHODS

In patients with biopsy-proven IgAN, urinary and plasma AGT was measured using a sandwich ELISA and compared with intrarenal AGT expression. The patients were followed up for 3 years.

RESULTS

Natural logarithm of the urinary AGT/creatinine (ln (urinary AGT/Cr)) was positively correlated with intrarenal expression of AGT (ln (urinary AGT/Cr) versus AGT/β-actin, r = 0.620, P < 0.0001; ln (urinary AGT/Cr) versus AGT density, r = 0.452, P = 0.007). Ln (urinary AGT/Cr) showed a positive correlation with urinary protein/creatinine ratio (PCR) but a negative correlation with estimated glomerular filtration rate (eGFR). Regression analyses showed that ln (urinary AGT/Cr) was a significant determinant of urinary PCR and eGFR 3 years after biopsy.

CONCLUSIONS

Urinary AGT reflects intrarenal AGT expression and correlates with the extent of proteinuria and renal function. Our study indicates the intrarenal compartment as the main source of urinary AGT, suggesting its clinical implication as an important biomarker in proteinuric IgAN patients.

Usefulness of genetic susceptibility and biomarkers for evaluation of environmental health risk

Recent attention is focused on understanding the genetic basis for individual susceptibility to the development of chronic disease. An emphasis is concentrated on establishing an association between inheritance of polymorphic chemical metabolizing genes and development of environmental cancer (e.g., lung cancer among cigarette smokers). The early reports of such associations have been very encouraging. However, some reported positive associations were not substantiated in subsequent studies using larger sample sizes and different ethnic populations. In this review, some confounding factors that contribute to the discrepancies are presented (e.g., ethnic-dependent distribution of variant gene alleles, differential expression of metabolizing genes, and inadequate study design). It is possible that the precision of the association can be improved if the mentioned investigations are complemented with concurrent studies of biological activities/effects. The usefulness of integrating metabolic susceptibility with biomarker measurement for understanding the development of lung cancers is presented. The importance of using adequate sample size and experimental design is emphasized. Development of a reliable approach for prediction of environmental disease not only will provide fundamental information regarding the genetic basis of human disease but will be useful for reducing disease burden in the population and for advancing patient care. Environ. Mol. Mutagen. 37:215-225, 2001. &copy 2001 Wiley-Liss, Inc.