893 research outputs found

    Early elimination of cyclosporine in kidney transplant recipients receiving sirolimus prevents progression of chronic pathologic allograft lesions

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    Cyclosporine elimination in a regimen including sirolimus has been shown to be a safe and effective approach to improve graft function. Nevertheless, it is still unknown whether the functional benefit of CyA withdrawal coincides with a subsequent reduction in histologic lesions of chronic damage or development of chronic allograft nephropathy. This consideration would forecast a reduction in the rate of long-term graft loss. We analyzed 114 graft biopsies from a subgroup of 57 patients that had been included in a randomized study to eliminate CyA at 3 months posttransplant from a regimen including sirolimus either in group A CyA + SRL vs group B of SRL with CyA elimination at 3 months. Every patient had two biopsies, one at transplantation and another at 1 year. The biopsy reading was performed in a blinded manner by a central pathologist using the Banff 1997 and the CADI classifications. A significantly lower rate of progression of tubular and interstitial chronic lesions between basal and 1-year biopsies was observed for group B patients. In addition, the incidence of new cases of chronic allograft nephropathy during the first year was significantly lower in the group in which CyA had been eliminated at 3 months posttransplant. We conclude that early elimination of CyA in the first months posttransplant, when SRL is used as the main immunosuppressant, reduces the appearance or worsening of chronic histologic lesions, probably as a consequence of long-term CyA toxicity prevention

    Early cyclosporine a withdrawal in kidney-transplant recipients receiving sirolimus prevents progression of chronic pathologic allograft lesions

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    BACKGROUND: Nephrotoxicity of calcineurin inhibitors (CNIs) is partially responsible for the development of chronic allograft nephropathy (CAN). Sirolimus has demonstrated its potential to substitute for CNIs because it lacks significant nephrotoxicity and shows a short-term immunosuppressive capacity comparable with that of cyclosporine. This results in the maintenance of better renal function when cyclosporine is eliminated, but it has not been demonstrated whether this benefit is associated with an improvement in the pathologic substrate and a reduction in CAN. METHODS: We analyzed pretransplant and 1-year renal-allograft biopsies from 64 patients enrolled in a multicenter trial. Patients received cyclosporine and sirolimus during the first 3 months after transplant and were then randomly assigned to continue with cyclosporine or have it withdrawn. Histologic chronic allograft lesions were compared between groups. RESULTS: The percentage of patients in whom chronic pathologic lesions progressed was lower in the group of cyclosporine elimination. Significant differences were observed in chronic interstitial and tubular lesions (70% vs. 40.9% [P<0.05] and 70% vs. 47.8% [P<0.05], respectively), whereas no differences were observed in acute lesions (subclinical rejection). Prevalence of CAN at 1 year was lower in this group, as was the severity and incidence of new cases (P<0.05). CONCLUSIONS: Early cyclosporine withdrawal associated with sirolimus administration is followed by an improvement in renal function, a reduction in the progression of chronic pathologic allograft lesions, and a lower incidence of new cases and severity of CAN during the first year after transplantation. This benefit may result in better long-term graft outcome

    Estrogen receptor, progesterone receptor, and bcl-2 are markers with prognostic significance in CIN III

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    There are no known biological markers or technologies to predict the natural history of an individual CIN III. The probability of progression is considered greater with the persistence of high-risk human papillomavirus (HPV) infection and age. p53 polymorphism has been associated with cervical carcinogenesis. Hormone-induced cervical cancer is mediated by estrogen receptor (ER) and progesterone receptor (PR). In cervical cancer, increased bcl-2 and Bax immunoreactivity is generally associated with a better prognosis. The purpose of this study was to evaluate the value of HPV 16 and HPV 18 typing and p53 codon polymorphism genotyping by polymerase chain reaction and ER, PR, bcl-2, and Bax expression by immunohistochemistry in predicting the CIN III clinical behavior of CIN III lesions. We studied the expression of these prognostic factors in the CIN III adjacent to squamous cell microinvasive carcinomas of the cervix (MIC) from 29 patients with FIGO stage IA1 cervical cancer and in 25 patients with CIN III and no documented focus of invasion. In the MIC group, only the CIN III was considered at least 2 mm away from the microinvasive complex. The ER, PR, bcl-2, and Bax immunoreactivity was scored as positive (>10% staining cells) and negative (<10% staining cells). No significant difference was observed between MIC and CIN III group concerning HPV infection and p53 polymorphism. The ER, PR, bcl-2, and Bax immunohistochemical expression was stronger and more frequent in the CIN III group. After multivariable analysis, coexpression of ER, PR, and bcl-2 was the only independent factor in defining low risk of progression for CIN III. Our study suggests that coexpression of ER, PR, and bcl-2 may be a useful tool in identifying the CIN III lesions with low risk of progression to cervical cance

    Transition of plasmodium sporozoites into liver stage-like forms is regulated by the RNA binding protein pumilio

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    Many eukaryotic developmental and cell fate decisions that are effected post-transcriptionally involve RNA binding proteins as regulators of translation of key mRNAs. In malaria parasites (Plasmodium spp.), the development of round, non-motile and replicating exo-erythrocytic liver stage forms from slender, motile and cell-cycle arrested sporozoites is believed to depend on environmental changes experienced during the transmission of the parasite from the mosquito vector to the vertebrate host. Here we identify a Plasmodium member of the RNA binding protein family PUF as a key regulator of this transformation. In the absence of Pumilio-2 (Puf2) sporozoites initiate EEF development inside mosquito salivary glands independently of the normal transmission-associated environmental cues. Puf2- sporozoites exhibit genome-wide transcriptional changes that result in loss of gliding motility, cell traversal ability and reduction in infectivity, and, moreover, trigger metamorphosis typical of early Plasmodium intra-hepatic development. These data demonstrate that Puf2 is a key player in regulating sporozoite developmental control, and imply that transformation of salivary gland-resident sporozoites into liver stage-like parasites is regulated by a post-transcriptional mechanism

    Peptides Derived from Vascular Endothelial Growth Factor B Show Potent Binding to Neuropilin-1

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    Vascular endothelial growth factors (VEGFs) regulate significant pathways in angiogenesis, myocardial and neuronal protection, metabolism, and cancer progression. The VEGF-B isoform is involved in cell survival, anti-apoptotic and antioxidant mechanisms, through binding to VEGF receptor 1 and neuropilin-1 (NRP-1). We employed surface plasmon resonance technology and X-ray crystallography to analyse the molecular basis of the interaction between VEGF-B and the b1 domain of NRP-1, and developed VEGF-B - C-terminus derived peptides to be used as chemical tools for studying VEGF-B - NRP-1 related pathways. Peptide lipidation was used as a means to stabilise the peptides. VEGF-B - derived peptides containing a C-terminal arginine show potent binding to NRP1-b1. Peptide lipidation increased binding residence time and improved plasma stability. A crystal structure of a peptide with NRP-1 demonstrated that VEGF-B peptides bind at the canonical C-terminal Arginine binding site. VEGF-B C-terminus imparts higher affinity for NRP-1 than the corresponding VEGF-A_{165} region. This tight binding may impact on the activity and selectivity of the full-length protein. The VEGF-B_{167} derived peptides were more effective than VEGF-A_{165} peptides in blocking functional phosphorylation events. Blockers of VEGF-B function have potential applications in diabetes and non-alcoholic fatty liver disease

    Block of NMDA receptor channels by endogenous neurosteroids: implications for the agonist induced conformational states of the channel vestibule

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    N-methyl-D-aspartate receptors (NMDARs) mediate synaptic plasticity, and their dysfunction is implicated in multiple brain disorders. NMDARs can be allosterically modulated by numerous compounds, including endogenous neurosteroid pregnanolone sulfate. Here, we identify the molecular basis of the use-dependent and voltage-independent inhibitory effect of neurosteroids on NMDAR responses. The site of action is located at the extracellular vestibule of the receptor's ion channel pore and is accessible after receptor activation. Mutations in the extracellular vestibule in the SYTANLAAF motif disrupt the inhibitory effect of negatively charged steroids. In contrast, positively charged steroids inhibit mutated NMDAR responses in a voltage-dependent manner. These results, in combination with molecular modeling, characterize structure details of the open configuration of the NMDAR channel. Our results provide a unique opportunity for the development of new therapeutic neurosteroid-based ligands to treat diseases associated with dysfunction of the glutamate system

    IFNAR1-Signalling Obstructs ICOS-mediated Humoral Immunity during Non-lethal Blood-Stage Plasmodium Infection

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    Funding: This work was funded by a Career Development Fellowship (1028634) and a project grant (GRNT1028641) awarded to AHa by the Australian National Health & Medical Research Council (NHMRC). IS was supported by The University of Queensland Centennial and IPRS Scholarships. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Metabolic risk factors, physical activity and physical fitness in azorean adolescents: a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>The prevalence of metabolic syndrome has increased over the last few decades in adolescents and has become an important health challenge worldwide. This study analyzed the relationships between metabolic risk factors (MRF) and physical activity (PA) and physical fitness (PF) in a sample of Azorean adolescents.</p> <p>Methods</p> <p>A cross-sectional school-based study was conducted on 417 adolescents (243 girls) aged 15-18 from the Azorean Islands, Portugal. Height, weight, waist circumference, fasting glucose, HDL-cholesterol, triglycerides, and blood pressure were measured. A sum of MRF was computed, and adolescents were classified into three groups: no MRF, one MRF and two or more MRF. PA was assessed by a sealed pedometer. PF was assessed using five tests from the Fitnessgram Test Battery. Dietary intake was obtained using a semi-quantitative food frequency questionnaire.</p> <p>Results</p> <p>Mean daily steps for girls and boys were 7427 ± 2725 and 7916 ± 3936, respectively. Fifty-nine percent of the adolescents showed at least one MRF and 57.6% were under the healthy zone in the 20 m Shuttle Run Test. Ordinal logistic regression analysis showed that after adjusting for sex, body mass index, socio-economic status and adherence to a Mediterranean diet, adolescents who were in the highest quartile of the pedometer step/counts (≥9423 steps/day) and those who achieved the healthy zone in five tests were less likely to have one or more MRF (OR = 0.56;95%CI:0.33-0.95; OR = 0.55;95%CI:0.31-0.98, respectively).</p> <p>Conclusions</p> <p>Daily step counts and PF levels were negatively associated with having one or more MRF among Azorean adolescents. Our findings emphasize the importance of promoting and increasing regular PA and PF to reduce the public health burden of chronic diseases associated with a sedentary lifestyle.</p
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