Kidney Transplantation, Cardiovascular Risk, and Long-Term Dialysis in Japan

BACKGROUND

The waiting time for deceased-donor kidney-only transplantations in Japan is long. Herein, we assessed the effect of length of dialysis on the outcomes of these patients.

METHODS

We divided patients into 2 groups based on length of dialysis (Group A, <15 years, and Group B, ≥15 years), and compared the background and outcomes after kidney transplantation.

RESULTS

Group A included 210 patients and Group B included 35 patients. In Group B, 20% of transplants were from living donors. Patient age (P = .017) and the hepatitis C infection rate (P = .018) were significantly higher in Group B, whereas hypertension (P = .011), diabetes (P = .041), and ABO-incompatibility rates (P = .015) were significantly higher in Group A. The 5- and 10-year survival rates were 97.0% and 95.4%, respectively, in Group A and 97.1% and 97.1%, respectively, in Group B. The 5- and 10-year graft survival rates were 95.4% and 84.8%, respectively, in Group A and 97.1% and 73.1%, respectively, in Group B. There were no significant differences between the groups in patient survival (P = .74) and graft survival (P = .72). The 5- and 10-year cardiovascular event-free survival rates were 95.9% and 92.4%, respectively, in Group A and 88.6% and 76.8%, respectively, in Group B. Cardiovascular event-free survival was significantly higher in Group A (P = .038). Cox stepwise multivariate analysis indicated that length of dialysis was a significant predictor of cardiovascular events (hazard risk, 1.007; range, 1.001-1.012; P = .012).

CONCLUSION

The prognosis after kidney transplantation is promising even after a long length of dialysis, although evaluation of the cardiovascular risk is needed in these cases.

Polyphenols and fatty acids responsible for anti-cyanobacterial allelopathic effects of submerged macrophyte Myriophyllum spicatum

Myriophyllum spicatum is known to inhibit the growth of cyanobacteria such as Microcystis aeruginosa by releasing anti-cyanobacterial allelochemicals. The allelochemicals possibly responsible for the inhibition include five polyphenols and three fatty acids, but the extent to which these are indeed responsible for the anti-cyanobacterial effects is unclear. The goal of this research was to determine the contribution of these compounds to the allelopathic effect of M. spicatum on M. aeruginosa. We first collected information on the release rates of these compounds and then added the compounds to a cyanobacterial medium on the basis of their release rates so as to simulate their excretion by M. spicatum. Addition of the polyphenols and fatty acids inhibited the growth of M. aeruginosa, and the interaction of the polyphenols and fatty acids was additive. The EC50 of a polyphenol and fatty acid mixture was compared with that of M. spicatum itself as previously determined in a mixed culture system in which M. spicatum and M. aeruginosa were incubated. The former was about 1.9 times higher than that of the latter, the implication being that the inhibitory effect of the polyphenols and fatty acids contributed about 53% of the allelopathic effect of M. spicatum. This paper is the first to describe allelochemicals that account for a half of the anti-cyanobacterial allelopathic effect of a macrophyte.

Reduction of Alzheimer's disease amyloid-β in plasma by hemodialysis and its relation to cognitive functions

BACKGROUND/AIMS

Rapid removal of plasma amyloid-β (Aβ) by blood purification may serve as a peripheral Aβ sink from the brain for Alzheimer's disease therapy. We investigated the reduction of plasma Aβ during hemodialysis and cognitive states.

METHODS

Aβ concentrations and Mini-Mental State Examinations (MMSE) were investigated in 37 hemodialysis patients (68.9 ± 4.1 years).

RESULTS

The dialyzers effectively removed Aβ(1-40) and Aβ(1-42), 63.9 ± 14.4 and 51.6 ± 17.0% at 4 h dialysis, resulting in the reduction of Aβs in whole-body circulation by 51.1 ± 8.9 and 32.7 ± 12.0%, respectively. Although the plasma Aβs before dialysis (750.8 ± 171.3 pg/ml for Aβ(1-40)) were higher than those reported for Alzheimer's disease patients, the cognitive states of hemodialysis patients were relatively normal, especially of longer dialysis vintages.

CONCLUSIONS

Dialyzers effectively reduced Aβs in whole-body circulation. Repeated rapid decrease of plasma Aβs might maintain cognitive state.

Prevention of lead leaching from fly ashes by mechanochemical treatment

Fly ashes from a municipal solid waste incinerator were subjected to mechanochemical (MC) treatment in a planetary ball mill, and the treated fly ashes were cemented with a binder. The leachability of lead (Pb) from the treated fly ashes and from the cement product were investigated, and the speciation of lead in the treated and untreated ashes was determined by X-ray absorption fine structure (XAFS) analysis. MC treatment of the fly ashes and subsequent cementation prevented Pb leaching by 99.9%, whereas MC treatment alone prevented Pb leaching by 92.8%. Analysis of the X-ray absorption near-edge spectrum of the untreated fly ashes revealed that the predominant Pb species in the ashes was PbCl(2). In contrast, the counterpart in the treated fly ashes was Pb(3)O(4) insoluble in water. The formation of a species of Pb with a lower solubility in water than that of PbCl(2) was confirmed by MC treatment of PbCl(2)-spiked fly ashes for 48h, indicating the reduction of PbCl(2) in the spiked fly ashes to Pb via Pb(3)O(4) during MC treatment. Our results indicate that such reduction to an insoluble species prevented Pb from leaching and that MC treatment followed by cementation is a feasible method for the recycling of fly ashes.

Higher survival rates of chronic hemodialysis patients on anti-hypertensive drugs

BACKGROUND

The effects of anti-hypertensive drugs on survival have not been examined in a large cohort of hemodialysis (HD) patients.

METHODS

We examined the relationship between blood pressure, anti-hypertensive drug therapy, and survival using the nationwide HD registry of the Japanese Society for Dialysis Therapy. Outcomes were confirmed using the coded ID numbers of the 2005 and 2006 registries. Logistic analyses were performed to determine the effect of anti-hypertensive drug therapy on survival.

RESULTS

A total of 163,668 patients (50.6% men; 31.5% with diabetes mellitus; mean age 63.6 years) on HD 3 times a week in 2005 were studied. Mean (SD) levels of systolic and diastolic blood pressure were 153.4 (24.1) and 78.7 (13.7) mm Hg, respectively, before the HD session. Two-thirds of the HD patients were prescribed anti-hypertensive drugs and the numbers of anti-hypertensive medications were: 1 in 26.8%, 2 in 24.4%, and 3 or more in 14.5% of the total patients. The 1-year mortality rate was 6.6% overall: 8.5% in patients not prescribed anti-hypertensive drugs and 5.6% among those prescribed anti-hypertensive drugs. The odds ratio (95% confidence interval) for the 1-year mortality rate was 0.724 (0.681-0.770, p < 0.0001) for patients prescribed anti-hypertensive drugs, after adjusting for age, sex, diabetes mellitus, body mass index, HD duration, serum albumin, and systolic blood pressure.

CONCLUSION

Survival was better in patients prescribed anti-hypertensive drugs, particularly renin-angiotensin system inhibitors, than in those not prescribed anti-hypertensive drugs. The causality on this association remained to be determined and prospective studies on blood pressure target levels and the effects of anti-hypertensive drug class in HD patients are warranted.