Present quantitative analysis clearly provided the first evidence that arterial calcification of lower limbs' arteries was closely associated with the prevalence and severity of PAD in HD patients. Furthermore, arterial calcification of below-knee arteries and micro-inflammation represented as CRP were the independent associating factors for low TBI, which was the independent associating factor for PAD and CLI in HD patients.

Employing a yeast two-hybrid screen with the COOH terminus of polycystin-2, one of the proteins mutated in patients with polycystic kidney disease, we were able to isolate a novel protein that we call PIGEA-14 (polycystin-2 interactor, Golgi-and endoplasmic reticulum-associated protein with a molecular mass of 14 kDa). Molecular modeling only predicts a coiled-coil motif, but no other functional domains, in PIGEA-14. In a subsequent two-hybrid screen using PIGEA-14 as a bait, we found GM130, a component of the cis-compartment of the Golgi apparatus. Co-expression of the PIGEA-14 and PKD2 cDNAs in LLC-PK 1 and HeLa cells resulted in a redistribution of PIGEA-14 and polycystin-2 to the trans-Golgi network, which suggests that PIGEA-14 plays an important role in regulating the intracellular location of polycystin-2 and possibly other intracellular proteins. Our results also indicate that the intracellular trafficking of polycystin-2 is regulated both at the level of the endoplasmic reticulum and that of the trans-Golgi network.

The risk factors of coronary artery calcification (CAC) and the impact of CAC on cardiovascular events, cardiovascular deaths, and all-cause deaths in hemodialysis (HD) patients have not been fully elucidated. We examined the CAC score (CACS) in 74 HD patients using electron-beam computed tomography. Fifty-six patients underwent a second electron-beam computed tomography after a 15-month interval to evaluate CAC progression. We evaluated (1) the risk factors for CAC and its progression and (2) the impact of CAC on the prognosis. In the cross-sectional study, HD vintage and high-sensitive C-reactive protein (hsCRP) were the independent risk factors for CAC. In the prospective cohort study, delta CACS (progression of CAC) was significantly correlated with hsCRP, fibrinogen, and serum calcium level in the univariate analysis. Stepwise multiple regression analysis revealed that only hsCRP was the independent risk factor for CAC progression in HD patients. Kaplan-Meier survival analysis revealed that cardiovascular events (P<0.0001), cardiovascular deaths (P=0.039), and all-cause deaths (P=0.026) were significantly associated with CACS. In conclusion, CAC had significantly progressed in HD patients during the 15-month observation period. Microinflammation was the only independent risk factor for CAC progression in HD patients. The advanced CAC was a significant prognostic factor in HD patients, i.e., which was strongly associated with future cardiovascular events, cardiovascular deaths, and all-cause deaths.

Clusterin is a secreted glycoprotein that is synthesized after several types of tubular injury. We therefore wondered whether the urinary excretion of clusterin could serve as a parameter to determine the severity of tubular damage. Using an affinity-purified rabbit antiserum raised against recombinant clusterin, we established an enzyme-linked immunosorbent assay to measure the urinary excretion of clusterin after bilateral renal ischemia, in the (cy/ +) rat model of autosomal-dominant polycystic kidney disease and in the FHH rat model of focal segmental glomerulosclerosis. After bilateral renal ischemia, the urinary excretion of clusterin paralleled the excretion of total protein and albumin and correlated with the extent of tubular damage. Male (cy/ +) rats, but not female (cy/ +) rats, excreted more clusterin than age-matched (+/ +) rats, a finding consistent with the more rapid course of the disease in males. FHH rats presented with pronounced proteinuria and albuminuria but did not excrete increased levels of clusterin. Urinary clusterin levels could therefore serve as a valuable marker for the severity of tubular damage. Furthermore, clusterin may also help to differentiate between tubular and glomerular forms of proteinuria.

This pilot study suggested that LC delayed progression of CAC in patients on HD compared with CC.

Atherosclerotic complications have a significant effect on mortality in patients undergoing hemodialysis (HD) therapy. However, anti-atherosclerotic and cardioprotective effects of on-line hemodiafiltration (HDF) remain to be elucidated. We prospectively compared the anti-atherosclerotic and cardioprotective effects in two randomly divided groups, i.e. on-line HDF group (n = 13) and conventional HD group (n = 9) for 1 year. Surrogate markers were brachial-ankle pulse wave velocity (baPWV), intima-media thickness (IMT) of carotid artery as an atherosclerosis marker, and cardiac functional surrogate markers included left ventricular mass index (LVMI), ejection fraction (EF), and LV diastolic capacity represented as E/A and deceleration time (DT). LVMI in on-line HDF patients showed significant regression after 1 year of treatment (131.9 Ϯ 25.8 to 116.5 Ϯ 24.7 g/m ). Levels of baPWV in HD patients showed a significant increase (11.4%) from basal levels, while on-line HDF groups showed no significant increase. Furthermore, HD patients showed significant worsening of LV diastolic capacity (E/A: from 0.87 Ϯ 0.12 to 0.79 Ϯ 0.08, P = 0.03), while it was not shown in on-line HDF patients. Ejection fraction and IMT did not show any significant change in both groups. Serum albumin, C-reactive protein, b2 microglobulin, blood pressure, and anti-hypertensive drug use did not change in both groups. On-line HDF showed a significant improvement in LVMI and prevented a significant worsening of baPWV or LV diastolic capacity compared with patients on conventional HD therapy.

The passage of various endogenous proteins [such as albumin, transferrin, immunoglobulin G (IgG), and immunoglobulin M (IgM)] across GBM was studied in vivo in normal Munich-Wistar rats. Glomeruli were fixed by three different methods: in situ drip-fixation, perfusion- and immersion-fixation; then they were processed for immunogold electron microscopy. The most reproducible results were obtained with in situ drip-fixation. Albumin, transferrin and IgG penetrated into GBM, but IgM did not. Morphometry revealed that density of albumin increased towards the inner 1/5 to 1/3 of GBM (junction of lamina rara interna and lamina densa) and decreased towards the subepithelial region of GBM, whereas density of IgG and transferrin was the highest at the subendothelial site and declined towards the subepithelial side of GBM. These findings suggest that central and/or outer zone of GBM constitute the main filtration barrier for albumin, and that subendothelial zone may contribute also to the charge-selective barrier. It is also suggested that the subendothelial zone acts more effectively as a filtration barrier for IgG and transferrin than for albumin. In the outer zone of GBM, which roughly corresponds to lamina rara externa visualized by conventional electron microscopy, the relative density of IgG and transferrin was higher than that of albumin. Since the pI of albumin was lower than that of IgG and transferrin, this finding suggests that subepithelial zone of GBM also acts as a charge-selective barrier. In conclusion, the main GBM filtration barrier for albumin might be the central and outer zones of GBM, and that for transferrin and IgG might be the entire width of GBM.(ABSTRACT TRUNCATED AT 250 WORDS)

AKI is more common among hospitalized patients and patients with AKI are more severely ill in winter.