Oxidative stress induced by iron released from transferrin in low pH peritoneal dialysis solution

Background. Transferrin binds extracellular iron and protectstissues from iron-induced oxidative stress. The binding of ironand transferrin is pH dependent and conventional peritonealdialysis (PD) solutions have unphysiologically low pH values.Herein, we investigated whether conventional PD solution releasesiron from transferrin and if the released iron causes oxidativestress. Methods. Effects of PD solutions on iron binding to transferrinwere examined with purified human transferrin and transferrinin dialysates drained from PD patients. Oxidative stress inducedby iron released from transferrin was evaluated in terms ofthe formation of thiobarbituric acid reactive substance (TBARS)and protein carbonylation in the human red blood cell (RBC)membrane. The iron deposition in peritoneal tissue from PD patientswas evaluated by Perls' staining with diaminobenzidine intensification. Results. Low pH PD solution released iron from transferrin.This iron release occurred within 1 min. Iron release was notobserved in neutralized PD solution. Iron released from transferrinin low pH PD solution increased TBARS formation and proteincarbonylation in the human RBC membrane. Iron deposition, whichis prominent in the fibrotic area facing the peritoneal cavity,was observed in the peritoneum of PD patients. Conclusions. Iron released from transferrin in low pH PD solutioncan produce oxidative stress in the peritoneum of a PD patient.Neutralizing PD solution can avoid this problem. Iron depositionin the peritoneum may participate in the pathogenesis of peritonealfibrosis in PD patients.     

Comparison of Near-Infrared Spectroscopy and Laser Doppler Flowmetry for Detecting Decreased Hepatic Inflow in the Porcine Liver

Hepatic artery and portal vein thrombosis are devastating complications of partial liver transplantation. Early detection of inflow complications is important, as re-reconstruction can salvage the graft. Near-infrared spectroscopy or laser Doppler flowmetry can be used to detect tissue oxygenation or microcirculation on the liver surface. The aim of this study was to examine which of these two methods better detects changes in hepatic inflow. Sangen-strain pigs (n = 5) were used. The tips of the near-infrared spectroscopy and laser Doppler flowmetry probes were placed separately on the surface of the right liver. Inflow to the liver was controlled during the following seven conditions: control (not clamped), half- and totally clamped portal vein, half- and totally clamped hepatic artery, and half- and totally clamped portal vein and artery. Tissue blood flow was calculated using laser Doppler flowmetry. Oxyhemoglobin, deoxyhemoglobin, and the tissue oxygenation index were measured and calculated using a near-infrared spectroscopy system. The tissue blood flow and oxygenation index could not be used to differentiate between the half-clamped portal vein, half-clamped hepatic artery, and totally clamped portal vein conditions. The oxyhemoglobin minus deoxyhemoglobin value was significantly decreased after half or total clamping of the portal vein or hepatic artery (p <. 001 for each condition). The findings of the present study indicate that near-infrared spectroscopy was more sensitive than Doppler flowmetry for detecting changes in hepatic tissue inflow from the liver surface.     

Clinical impact of amyloid PET using 18F-florbetapir in patients with cognitive impairment and suspected Alzheimer’s disease: a multicenter study

Annals of Nuclear Medicine - Amyloid positron emission tomography (PET) can reliably detect senile plaques and fluorinated ligands are approved for clinical use. However, the clinical impact of...     

Platelet-rich plasma combined with hydroxyapatite for lumbar interbody fusion promoted bone formation and decreased an inflammatory pain neuropeptide in rats

STUDY DESIGN.: A prospective interventional trial, using a rat model of lumbar interbody fusion. OBJECTIVE.: To examine the potential efficacy of platelet-rich plasma (PRP) for lumbar interbody fusion, using hydroxyapatite (HA). SUMMARY OF BACKGROUND DATA.: PRP is an autologous product containing a high concentration of platelets in a small volume of plasma and has osteoinductive effects. HA has osteoconductive ability and has been used in combination with autogenous bone for spine fusion. However, reports using PRP with HA for spine fusion are very few. The purpose of this study was to examine the efficacy of PRP with HA for spinal interbody fusion and at the same time to estimate the change in immunoreactivity of the inflammatory neuropeptide, calcitonin gene-related peptide (CGRP), in dorsal root ganglion (DRG) neurons innervating spinal discs. METHODS.: A total of 35 Sprague-Dawley rats were used in this study. Twenty-one rats were used for conducting interbody fusion experiments, 7 rats were used as immunostaining controls, and 7 other rats were used as blood donors for making PRP. L5-L6 interbody fusion was performed on 21 rats using HA + PRP (n = 7), HA + platelet-poor plasma (n = 7), or HA + saline (n = 7). Simultaneously, Fluoro-Gold neurotracer was applied to the intervertebral space to detect DRG neurons innervating the discs. L5-L6 lumbar radiographs were obtained and lumbar DRGs were immunostained for CGRP. The rate of bone union and the change in CGRP immunoreactive DRG neurons innervating the discs were evaluated and compared among groups. RESULTS.: All L5-L6 lumbar discs were fused in the PRP + HA group (fused 7/total 7), whereas only 1 case was fused in the platelet-poor plasma group (1 of 7) and no cases in the HA-only group (0 of 7), which was a significant difference. Upon immunohistochemical analysis, CGRP-positive neurons innervated L5-L6 intervertebral discs in nonunion cases, and these were significantly increased compared with those in union cases. CONCLUSION.: Our study suggests that using PRP with HA was beneficial for spine fusion. This combination may promote bone union and also decrease inflammatory neuropeptide in sensory neurons innervating the discs.     

Median nerve deformation in differential finger motions: ultrasonographic comparison of carpal tunnel syndrome patients and healthy controls

We investigated the median nerve deformation in the carpal tunnel in patients with carpal tunnel syndrome and controls during thumb, index finger, middle finger, and a four finger motion, using ultrasound. Both wrists of 29 asymptomatic volunteers and 29 patients with idiopathic carpal tunnel syndrome were evaluated by ultrasound. Cross‐sectional images during motion from full extension to flexion were recorded. Median nerve cross‐sectional area, perimeter, aspect ratio of the minimal enclosing rectangle, and circularity in extension and flexion positions were calculated. Additionally, a deformation index was calculated. We also calculated the intra‐rater reliability. In both controls and patients, the median nerve cross‐sectional area became significantly smaller from extension to flexion in all finger motions (p < 0.05). In flexion and extension, regardless of the specific finger motion, the median nerve deformation, circularity and the change in perimeter were all significantly greater in CTS patients than in controls (p < 0.05). We found excellent intra‐rater reliability for all measurements (ICC > 0.84). With this study we have shown that it is possible to assess the deformation of the median nerve in carpal tunnel syndrome with ultrasonography and that there is more deformation of the median nerve in carpal tunnel syndrome patients during active finger motion. These parameters might be useful in the evaluation of kinematics within the carpal tunnel, and in furthering our understanding of the biomechanics of carpal tunnel syndrome in the future. © 2011 Orthopaedic Research Society. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:643–648, 2012     

Clinical, histological, and genetic features of fourth ventricle ependymoma in the elderly

A 71-year-old woman presented with a rare case of geriatric ependymoma originating from the fourth ventricle manifesting as progressive gait and memory disturbance. Imaging studies revealed an extraaxial mass in the fourth ventricle protruding into the right cerebellomedullary cistern, with concomitant obstructive hydrocephalus. Surgery achieved subtotal removal since the tumor tightly adhered to the right vestibular area of the fourth ventricular floor. The histological diagnosis was ependymoma, which was also confirmed by comparative genetic hybridization. Although she developed severe laryngeal edema and worsening of the hydrocephalus postoperatively which required additional treatment, she recovered with residual mild gait disturbance, and was transferred to a rehabilitation facility. Fourth ventricle ependymoma in the elderly is rare. Comparative genetic hybridization may be important in the diagnosis of geriatric ependymoma and in the choice for adjuvant therapy as well as in estimating the prognosis for patients with rare types of ependymoma.     

Early and late outcomes of coronary artery bypass surgery versus percutaneous coronary intervention with drug-eluting stents for dialysis patients

Abstract Background: Advances in percutaneous coronary intervention (PCI) using drug‐eluting stents (DES) have impacted clinical practice. However, the efficacy of DES for dialysis patients still remains controversial. This study compares the early and long‐term clinical outcomes of coronary artery bypass grafting (CABG) and PCI with DES in dialysis patients. Methods: A retrospective review was performed in 125 dialysis patients treated between 2004 and 2007. Fifty‐eight patients underwent CABG and 67 underwent PCI with DES. The overall death, cardiac death, and cardiac‐related event rates were analyzed using the Kaplan‐Meier method. For the risk‐adjusted comparisons, multivariable logistic and Cox regression analyses were used. Results: The preoperative characteristics of the patients were similar except for the ejection fraction (p = 0.002) and the number of diseased vessels (p < 0.001). The 30‐day mortality was 0 in both groups. The overall survival rates at one, three, and five years were 84.2%, 64.7%, and 56.2% in CABG group and 88.2%, 75.5%, and 61.7% in DES group, respectively (p = 0.202). The rates of freedom from cardiac‐related events at one, three, and five years were 76.6%, 68.1%, and 48.6%, and 63.0%, 31.4%, and 0% in CABG and DES groups (p < 0.001), respectively, including seven (10%) late thromboses in the DES group. Although the risk‐adjusted analysis showed no significant difference for overall and cardiac death rates, the rates of cardiac‐related events and graft/stent failure were significantly higher in the DES group. Conclusions: CABG is superior for revascularization in dialysis patients compared with PCI using DES in terms of freedom from cardiac‐related events. (J Card Surg 2012;27:281‐287)     

Impact of pre‐implant lower urinary tract symptoms on postoperative urinary morbidity after permanent prostate brachytherapy

Objectives: To assess the impact of baseline lower urinary tract symptoms on postoperative urinary morbidity in patients being treated for prostate cancer with 125‐I permanent prostate brachytherapy. Methods: A total of 104 prostate cancer patients were enrolled in this study. Their urinary morbidity was followed up using the International Prostate Symptom Score and Expanded Prostate Cancer Index Composite for 12 months or more after permanent prostate brachytherapy. Patients were classified into two groups based on their baseline International Prostate Symptom Score: the low International Prostate Symptom Score group (score ≤ 7) and the high International Prostate Symptom Score group (score ≥ 8). Urinary morbidity was estimated in each group based on the results of the International Prostate Symptom Score and Expanded Prostate Cancer Index Composite measured before permanent prostate brachytherapy, and at 1, 3, 6, 9 and 12 months after the end of all radiation therapy. Results: The overall mean total International Prostate Symptom Score, International Prostate Symptom Score quality of life score, and urinary‐related scores for Expanded Prostate Cancer Index Composite were significantly worse at 1 month after the end of treatment, but they improved gradually after the treatment and recovered to the baseline level within 12 months. Even in the high‐International Prostate Symptom Score group, the International Prostate Symptom Score and International Prostate Symptom Score Quality of Life score were significantly worse at 1–3 months after permanent prostate brachytherapy, and then recovered to the baseline level without prolongation. Although the urination‐related Expanded Prostate Cancer Index Composite score in the high‐International Prostate Symptom Score group was significantly worse at 1 month after permanent prostate brachytherapy in comparison with that in the low‐International Prostate Symptom Score group, it recovered to the baseline level without prolongation. Conclusions: The present findings suggest that the presence of lower urinary tract symptoms before implantation does not prolong urinary morbidity after permanent prostate brachytherapy.     

Impaired expression of hepatic multidrug resistance protein 2 is associated with posthepatectomy hyperbilirubinemia in patients with biliary cancer

Background and aims Hyperbilirubinemia is a critical complication following hepatectomy for biliary cancer. Hepatic multidrug resistance protein 2 (MRP2), a bilirubin transporter, is shown to be down-regulated by acute biliary obstruction in rats. However, little is known about the effect of chronic obstruction by malignancy on the MRP2 expression in patients or the association of MRP2 expression with posthepatectomy hyperbilirubinemia.Materials and Methods The MRP2 expression before hepatectomy was determined by immunostaining and Western blotting in patients with biliary cancer. To directly determine the effect of chronic bile duct obstruction on the MRP2 expression, the expression levels were compared between the cholestatic and noncholestatic lobes in each of seven patients. In another 39 patients, the correlation of the MRP2 expression of the anticipated remnant liver with the posthepatectomy severe hyperbilirubinemia, defined as a serum total bilirubin concentration200 mol/l, was evaluated.Results The MRP2 staining in the cholestatic lobes was weak and not restricted to the canalicular membrane, unlike the noncholestatic lobes. The expression levels in the cholestatic lobes were 45% of those in the noncholestatic lobes. Postoperative maximum bilirubin levels were significantly correlated with MRP2 expression of the anticipated remnant liver. The MRP2 expression had been already impaired before hepatectomy in all patients who eventually developed severe hyperbilirubinemia.Conclusions Decreased MRP2 expression, caused by biliary obstruction due to cancer, is a possible risk factor for posthepatectomy severe hyperbilirubinemia.