Factors associated with leisure-time physical activity among patients undergoing hemodialysis

Intermedin (IMD) is a novel member of the calcitonin/calcitonin gene-related peptide family. Endoplasmic reticulum stress (ERS) has been implicated in the pathology of renal ischemia/reperfusion (IRI). In the present study, we investigated whether IMD could reduce ERS damage after renal ischemia. The kidneys of SD rats were subjected to 45 min of warm ischemia followed by 24 h of reperfusion. The hypoxia/reoxygenation(H/R) model in NRK-52E cells consisted of hypoxia for 1 h and reoxygenation for 2 h. IMD was over-expressed in vivo and in vitro using the vector pcDNA3.1-IMD. The serum creatinine concentration and lactate dehydrogenase (LDH) activity in the plasma were determined. Histologic examinations of renal tissues were performed with PAS staining. Real-time PCR and Western blotting were used to determine the mRNA and protein levels, respectively. Additionally, ER staining was used to detect the ERS response. In the rat renal IRI model, we found that IMD gene transfer markedly improved renal function and pathology and decreased LDH activity and cell apoptosis compared with the kidneys that were transfected with the control plasmid. IMD significantly attenuated the ERS stress parameters compared with IRI group. Indeed, IMD down-regulated glucose-regulated protein 78 (GRP78), C/EBP homologous protein(CHOP), and caspase 12 protein and mRNA levels. Moreover, in the NRK-52E cell H/R model, IMD overexpression prevented the apoptosis induced by H/R. Furthermore, IMD ameliorated the ER structural changes and concomitantly decreased the levels of GRP78, CHOP and caspase-12. This study revealed that IMD protects against renal IRI by suppressing ERS and ERS-related apoptosis.     

Activation of A2A adenosine receptor attenuates intestinal inflammation in animal models of inflammatory bowel disease

BACKGROUND & AIMS: Adenosine has been implicated as an important regulator of the inflammatory response. Four subtypes of adenosine receptors (A 1 , A 2A , A 2B , and A 3 ) have been described, of which A 2A potentially inhibits inflammation. The aim of this study was to investigate the role of A 2A in mucosal inflammation by administering a selective A 2A agonist (ATL-146e) to experimental models of inflammatory bowel disease. METHODS: The anti-inflammatory effects of ATL-146e were studied in the acute and chronic rabbit formalin-immune complex models of colitis and the SAMP1/YitFc mouse model of spontaneous ileitis. RESULTS: ATL-146e significantly reduced the acute inflammatory index and tissue necrosis compared with vehicle ( P < .01) in the acute model of rabbit immune colitis. In the chronic rabbit immune colitis model, ATL-146e significantly suppressed inflammatory cell infiltration into the colonic mucosa ( P < .05) and prevented mortality. The administration of ATL-146e significantly decreased the chronic inflammatory index ( P < .01) and villus distortion index ( P < .01) in the ileum of SAMP1/YitFc mice, and ameliorated adoptively transferred ileitis in severe combined immunodeficient mice injected with CD4 + T cells from SAMP1/Yit mice ( P < .05). Tumor necrosis factor, interferon gamma, and interleukin 4 concentrations were significantly suppressed by ATL-146e treatment in supernatants from cultures of mesenteric lymph node cells of SAMP1/YitFc mice ( P < .05 vs vehicle-treated mice). CONCLUSIONS: A 2A adenosine receptor activation by ATL-146e significantly reduced inflammation in the intestinal mucosa. This effect was associated with decreased leukocyte infiltration and inhibition of proinflammatory cytokines. Activation of A 2A by selective agonism may therefore serve as a novel therapy for the treatment of inflammatory bowel disease.     

The effect of finite patient dimensions and tissue inhomogeneities on dosimetry planning of Ir HDR breast brachytherapy: A Monte Carlo dose verification study

PURPOSE: To evaluate the accuracy of clinical dosimetry planning using commercially available treatment planning systems in (192)Ir high-dose-rate (HDR) breast brachytherapy, with emphasis on skin dose, in view of potential uncertainties owing to the patient finite dimensions and the presence of the lung. METHODS AND MATERIALS: A patient-equivalent mathematical phantom was constructed on the basis of the patient computed tomography scan used in the clinical treatment planning procedure. The actual treatment plan delivered to the patient, involving an implant of six plastic catheters and 26 programmed source dwell positions, was simulated by means of the Monte Carlo method. Results are compared with corresponding dose calculations of a commercially available treatment planning system in the form of prescribed dose percentage isodose contours and cumulative dose-volume histograms. RESULTS: The comparison of Monte Carlo results and treatment planning system calculations revealed that all percentage isodose contours greater than 60% of the prescribed dose are not affected by the finite breast dimensions or the presence of the lung. Treatment planning system calculations overestimate dose in the lung as well as lower isodose contours at points lying both close to the breast or lung surface and relatively away from the implant. In particular, skin dose is overestimated by 5% in the central breast region and within 10% at all other points. CONCLUSIONS: Dose-volume histogram and all other relevant planning quality indices for the planning target volume calculated by the treatment planning system are credible. Skin and lung dose calculations by the treatment planning system can be thought of as a conservative approach in view of the reported dose overestimation.     

High frequency stimulation of the subthalamic nucleus increases c-fos immunoreactivity in the dorsal raphe nucleus and afferent brain regions

High frequency stimulation (HFS) of the subthalamic nucleus (STN) is the neurosurgical therapy of choice for the management of motor deficits in patients with advanced Parkinson’s disease, but this treatment can elicit disabling mood changes. Our recent experiments show that in rats, HFS of the STN both inhibits the firing of 5-HT (5-hydroxytryptamine; serotonin) neurons in the dorsal raphe nucleus (DRN) and elicits 5-HT-dependent behavioral effects. The neural circuitry underpinning these effects is unknown. Here we investigated in the dopamine-denervated rat the effect of bilateral HFS of the STN on markers of neuronal activity in the DRN as well as DRN input regions. Controls were sham-stimulated rats. HFS of the STN elicited changes in two 5-HT-sensitive behavioral tests. Specifically, HFS increased immobility in the forced swim test and increased interaction in a social interaction task. HFS of the STN at the same stimulation parameters, increased c-fos immunoreactivity in the DRN, and decreased cytochrome C oxidase activity in this region. The increase in c-fos immunoreactivity occurred in DRN neurons immunopositive for the GABA marker parvalbumin. HFS of the STN also increased the number of c-fos immunoreactive cells in the lateral habenula nucleus, medial prefrontal cortex but not significantly in the substantia nigra. Collectively, these findings support a role for circuitry involving DRN GABA neurons, as well as DRN afferents from the lateral habenula nucleus and medial prefrontal cortex, in the mood effects of HFS of the STN.     

A rare RET gene exon 8 mutation is found in two Greek kindreds with familial medullary thyroid carcinoma: implications for screening

OBJECTIVE: Familial medullary thyroid carcinoma (FMTC) is caused by germ-line mutations in the RET proto-oncogene. These mutations concern mainly cysteine residues in exons 10 and 11, whereas noncysteine mutations in exons 13-16 are rare. Mutations in other exons have been reported only in isolated families. In this study we have analysed the RET gene in two FMTC families negative for mutations in the above exons. DESIGN: We have analysed exons 7-19 and 21 in one index patient from each family using DNA sequencing. PATIENTS: Twenty-eight subjects from both families were clinically assessed and subsequently molecularly analysed for the presence of RET gene mutations. RESULTS: We have found the mutation c.1597G-->T (Gly533Cys) in two Greek families with FMTC. The mutation was detected in all seven MTC patients of both families as well as in 13 asymptomatic relatives in the heterozygote state, although one of the patients was also a homozygote due to consanguinity. The mutation shows a wide clinical heterogeneity, as there are carrier patients with age of diagnosis ranging from 23 to 88 years. CONCLUSIONS: It is likely that this mutation causes FMTC, as no other mutation was found in the RET gene, the mutation co-segregates with FMTC, and family members without the mutation are clinically unaffected. As the same point mutation was previously found in a large Brazilian family, it may be present in other populations as well. Therefore, exon 8 of RET should be screened in FMTC families with no identified common RET mutations.     

Activation of p38 MAPK is a key step in tumor necrosis factor-mediated inflammatory bone destruction

OBJECTIVE: To investigate whether activation of p38 MAPK is a crucial signaling factor in inflammatory bone destruction mediated by tumor necrosis factor (TNF). Mice overexpressing TNF were treated with 2 different inhibitors of p38 MAPK, and the effect of this treatment on joint inflammation and structural damage was assessed. METHODS: Human TNF-transgenic mice received systemic treatment with 2 different p38 MAPK inhibitors (RO4399247 and AVE8677). Treatment was started at the time of symptom onset and lasted for 6 weeks. Mice were assessed for clinical signs of arthritis, bone erosion, and cartilage damage. In addition, the effect of these inhibitors on osteoclast generation in vitro and in vivo was assessed. RESULTS: Both p38 MAPK inhibitors significantly reduced clinical signs of TNF-mediated arthritis. This was attributable to reducing synovial inflammation by 50% without affecting the cellular composition of the infiltrate. Synovial expression of interleukin-1 and RANKL was reduced upon p38 MAPK blockade, and activation of the molecular target MAPK-activated protein kinase 2 (MAPKAP-2) was also inhibited. Proteoglycan loss of articular cartilage was reduced by 50%, although p38 MAPK inhibition did not change matrix molecule synthesis by cultivated chondrocytes. Importantly, bone loss was almost completely prevented by p38 MAPK inhibition. The numbers of synovial osteoclasts and precursors were dramatically reduced, and both p38 MAPK inhibitors also inhibited in vitro osteoclastogenesis at micromolar concentrations and blocked activation of MAPKAP-2 as well as differentiation markers in cultured osteoclast precursors. CONCLUSION: These results suggest the major importance of p38 MAPK for TNF-mediated inflammatory bone destruction in arthritis and suggest that inhibition of p38 MAPK might be an important tool for reducing structural damage in rheumatoid arthritis.     

Management of hepatitis B virus infection in patients with inflammatory bowel disease under immunosuppressive treatment

Hepatitis B remains a significant global clinical problem, despite the implementation of safe and effective vaccination programs. The prevalence of hepatitis B virus (HBV) in patients with inflammatory bowel disease (IBD) largely follows the regional epidemiologic status. Serological screening with hepatitis B surface antigen (HBsAg), and antibodies to hepatitis B surface (anti-HBs) and core (anti-HBc) proteins is a key element in the management of IBD patients and, ideally, should be performed at IBD diagnosis. Stratification of individual cases should be done according to the serologic profile and the IBD-specific treatment, with particular emphasis in patients receiving immunosuppressive regimens. In patients who have not contracted HBV, vaccination is indicated to accomplish protective immunity. Vaccination in immunosuppressed patients, however, is a challenging issue and several strategies for primary and revaccination have been proposed. The risk of HBV reactivation in patients with IBD should be considered in both HBsAg-positive and HBsAg-negative/anti-HBc-positive patients, when immunosuppressive therapies are administered. HBV reactivation is preventable via the administration of prophylactic nucleot(s)ide analogues and should be the standard approach in HBsAg-positive patients. HBsAg-negative/anti-HBc-positive patients represent a non-homogeneous group and bear a significantly lower risk of HBV reactivation. Biochemical, serological and molecular monitoring is currently the recommended approach for anti-HBc patients. Acute HBV infection is rarely reported in IBD patients. In the present review, we outline the problems associated with HBV infection in patients with IBD and present updated evidence for their management.