In vivo klotho gene transfer ameliorates angiotensin II-induced renal damage

The klotho gene, originally identified by insertional mutagenesis in mice, suppresses the expression of multiple aging-associated phenotypes. This gene is predominantly expressed in the kidney. Recent studies have shown that expression of renal klotho gene is regulated in animal models of metabolic diseases and in humans with chronic renal failure. However, little is known about the mechanisms and the physiological relevance of the regulation of the expression of the klotho gene in the kidney in some diseased conditions. In the present study, we first investigated the role of angiotensin II in the regulation of renal klotho gene expression. Long-term infusion of angiotensin II downregulated renal klotho gene expression at both the mRNA and protein levels. This angiotensin II-induced renal klotho downregulation was an angiotensin type 1 receptor-dependent but pressor-independent event. Adenovirus harboring mouse klotho gene (ad-klotho, 3.3x10(10) plaque forming units) was also intravenously administered immediately before starting angiotensin II infusion in some rats. This resulted in a robust induction of Klotho protein in the liver at day 4, which was still detectable 14 days after the gene transfer. Ad-klotho gene transfer, but not ad-lacZ gene transfer, caused an improvement of creatinine clearance, decrease in urinary protein excretion, and amelioration of histologically demonstrated tubulointerstitial damage induced by angiotensin II administration. Our data suggest that downregulation of the renal klotho gene may have an aggravative role in the development of renal damage induced by angiotensin II, and that induction of the klotho gene may have therapeutic possibilities in treating angiotensin II-induced end organ damage.     

Peculiar mechanisms of graft recovery through anti-inflammatory responses after rat lung transplantation from donation after cardiac death

BackgroundAlthough lung transplantation from donation after cardiac death (DCD), especially uncontrolled DCD, is limited by warm ischemic periods, the molecular mechanism of warm ischemia–reperfusion-injury (IRI) has not been well elucidated. The purpose of this study was to clarify the particular longitudinal mechanisms of molecular factors involved in warm IRI.MethodsCold ischemic-time (CIT)-group lungs were retrieved and subjected to 3-h of cold preservation, whereas warm ischemic-time (WIT)-group lungs were retrieved after 3-h of warm ischemia. Orthotopic rat lung transplantation was performed and the grafts were reperfused for 1 or 4-h. The graft functions, gene expression, and activation of inflammatory molecules in the grafts were analyzed. Exhaled-carbon-monoxide-concentration (ExCO-C) was measured during reperfusion.ResultsOnly the WIT-group showed obvious primary graft dysfunction at 1-h reperfusion, but the graft function was recovered during 4-h reperfusion. Most of pro-inflammatory cytokines and stress-induced molecules showed different expression and activation patterns between CIT and WIT groups. In the WIT-group, the expressions of anti-inflammatory molecules, IL-10 and HO-1, were significantly increased at 1-h reperfusion compared to the CIT-group, and these high levels were maintained through 4-h reperfusion. Furthermore, ExCO-C levels in the WIT-group increased immediately after reperfusion compared to the CIT-group.ConclusionsThis study indicates that warm IRI may involve a different mechanism than cold IRI and anti-inflammatory pathways may play important roles in the graft recovery after lung transplantation from uncontrolled DCD.     

Intrathoracic irrigation with arbekacin for methicillin-resistant Staphylococcus aureus empyema following lung resection

OBJECTIVES Empyema is a well-known complication following lung resection. In particular, empyema caused by methicillin-resistant Staphylococcus aureus (MRSA) is difficult to treat. Here, we present our experience of MRSA empyema treated with local irrigation using arbekacin. METHODS Six patients consisted of 4 males and 2 females with an average age of 65.7 years. They developed MRSA empyema following lung resection and were treated at our institution between 2007 and 2011. Cases comprised four primary and one metastatic lung cancer, and 1 patient was a living lung transplantation donor. The surgical procedure consisted of four lobectomies, one segmentectomy and one wedge resection. After diagnosis of MRSA empyema, anti-MRSA drugs were administered intravenously in all cases. In addition, arbekacin irrigation at a dose of 100?mg dissolved in saline was performed after irrigation with saline only. RESULTS The average number of postoperative days for the diagnosis of MRSA empyema was 13 (range 4-19). The period of irrigation ranged from 6 to 46 days. Arbekacin irrigation did not induce nephrotoxicity or other complications, and no bacteria resistant to arbekacin was detected in the thoracic cavity. We re-operated on 1 case because he had pulmonary fistula and severe wound infection. At the time of removing the thoracic catheter, MRSA in the pleural effusion disappeared completely in 3 patients. The period until MRSA concentration in the pleural effusion became negative after starting arbekacin irrigation ranged from 4 to 9 days. In the remaining cases, in which MRSA did not disappear, the catheter was removed because of no inflammatory reaction after stopping irrigation and clamping the catheters. All patients were discharged from our institution without thoracic catheterization and no patients had relapsed during the follow-up period ranging from 6 to 44 months. CONCLUSIONS Irrigation of the thoracic cavity with arbekacin proved to be an effective, safe and readily available method for treating MRSA empyema following lung resection.     

Antitachycardia burst pacing for pleomorphic reentrant ventricular tachycardias associated with non-coronary artery diseases: a morphology specific programming for ventricular tachycardias

To study the role of antitachycardia burst pacing in patients with reentrant pleomorphic ventricular tachycardia (VT) associated with non-coronary artery diseases, the efficacy of antitachycardia pacing and appropriate antitachycardia pacing cycle length were evaluated in each pleomorphic VT morphology of seven patients. Seven patients were included in this study. Clinically documented pleomorphic VTs were reproduced in an electrophysiologic study. For each VT, rapid ventricular pacing was attempted from the apex of the right ventricle at a cycle length which was 20 ms shorter than that of VT and repeated after a decrement of the cycle length in steps of 10 ms until the VT was terminated or accelerated. All 16 VTs could be entrained by the rapid pacing, and 13 of the 16 VTs (81%) were terminated, whereas pacing-induced acceleration was observed in the other 3 VTs of the 3 patients. VT cycle length (VTCL), block cycle length (BCL) which was defined as the longest VT interrupting paced cycle length, %BCL/VTCL and entrainment zone which was defined as VTCL minus BCL, varied in each VT morphology of each patient. In two patients, antitachycardia pacing was effective in all VT morphologies and the maximum difference of the %BCL/VTCL among the pleomorphic VTs was less than 10%. Thus, antitachycardia pacing seemed to be beneficial for these patients. In the other 5 patients, a difference of more than 10% in %BCL/VTCL was observed among the pleomorphic VT morphologies and/or at least one VT morphology showed pacing-induced acceleration. Compared to the 13 terminated VTs, three accelerated VTs had a wide entrainment zone [160 +/- 44 vs 90 +/- 48 ms, p < 0.04] and small %BCL/VTCL [61 +/- 6 vs 77 +/- 11%,p<0.03]. In pleomorphic VTs associated with non-coronary artery diseases, responses to rapid pacing was not uniform; VT might be terminable or accelerated even in the same patient. We need to pay close attention when programming antitachycardia pacing in patients with pleomorphic VT.     

Proarrhythmic effects of antiarrhythmic drugs assessed by electrophysiologic study in recurrent sustained ventricular tachycardia

Proarrhythmic responses were evaluated in repeated electrophysiologic studies (EPS) in 27 patients with inducible ventricular tachycardia (VT). Class Ia drugs were administered to 23, Ib to 6, Ic to 4, III to 5 and IV to 9 patients. The mean age was 53 years, and 18 patients had structural heart diseases. Pleomorphism was observed in 11 patients. In 4 patients (15%), the VT cycle length (CL) shortened by 50 ms or more in EPS during the administration of antiarrhythmic drugs. VT was inducible by a less aggressive induction mode than the control study in 9 patients (33%). In 4 patients (15%), the induced VT changed to the incessant form, and the other 2 patients (7%) required DC shocks due to hemodynamic deterioration. Patients with pleomorphic VT and/or structural heart diseases seemed to develop proarrhythmia more frequently. In total, some proarrhythmic response was observed in 13 (48%) of the 27 patients. Therefore, it should be kept in mind that proarrhythmic effects are frequently observed during antiarrhythmic therapy in patients with sustained VT. The action of the drugs on the slow conduction zone may vary, which may provide a basis for the development of proarrhythmia.     

Loss of cellular viability in areas of ground-glass opacity on computed tomography images immediately after pulmonary radiofrequency ablation in rabbits

Purpose  

To determine cellular viability of lung parenchyma and neoplastic cells in areas of ground-glass opacity (GGO) on computed tomography (CT) images immediately after pulmonary radiofrequency ablation (RFA) in rabbits.     

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.     

Tumor budding is predictive of lymphatic involvement and lymph node metastases in submucosal invasive colorectal adenocarcinomas and in non-polypoid compared with polypoid growths

Objective. Early colorectal carcinomas (submucosal invasive adenocarcinomas) can be classified into polypoid and non-polypoid growth types, the latter progressing more rapidly to advanced malignancy. The aim of this study was to investigate the differences between invasive features of the two types of carcinoma by focusing on tumor budding (isolated single cells or small cell clusters (up to four cells) scattered at invasive tumor margins). Material and methods. The number of foci in the field with the most frequent tumor budding was regarded as “activity”. Tumor budding was examined using anti-cytokeratin antibodies in 98 colorectal submucosal invasive adenocarcinomas and compared with the clinicopathological findings. In addition, the relationships between tumor budding and β-catenin and laminin-5γ2 expression were analyzed. Results. Tumor budding activity was significantly higher in non-polypoid growth carcinomas compared with polypoid growth carcinomas (p = 0.0006) and values for left-sided lesions were higher than those for right-sided lesions of the colon (p = 0.0108). Positive links with tumor budding were evident for lymphatic involvement and lymph node metastasis in non-polypoid growth carcinomas, and with laminin-5γ2 cytoplasmic expression in polypoid growth carcinomas. Multivariate logistic analysis revealed that the activity of tumor budding was an independent risk factor for lymphatic involvement. Conclusions. The results indicate that tumor budding makes a greater contribution to progression in non-polypoid than in polypoid growth carcinomas, with possible involvement of lymph node metastasis.