960 resultados para Type-1 Fimbriae


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Alveolar bone resorption results from the inflammatory response to periodontal pathogens. Systemic diseases that affect the host response, such as type 1 diabetes mellitus (DM1), can potentiate the severity of periodontal disease (PD) and accelerate bone resorption. However, the biological mechanisms by which DM1 modulates PD are not fully understood. The aim of this study was to determine the influence of DM1 on alveolar bone resorption and to evaluate the role of receptor activator of nuclear factor-kappaB ligand (RANKL)/osteoprotegerin (OPG) in osteoclastogenesis in rats. PD was induced by means of ligature in nondiabetic and in streptozotocyn-induced DM1 rats. Morphological and morphometric analyses, stereology and osteoclast counting were performed. RANKL and OPG mRNA levels, protein content, and location were determined. PD caused alveolar bone resorption, increased the number of osteoclasts in the alveolar bone crest and also promoted changes in RANKL/OPG mRNA expression. DM1 alone showed alveolar bone destruction and an increased number of osteoclasts at the periapical and furcal regions. DM1 exacerbated these characteristics, with a greater impact on bone structure, resulting in a low OPG content and a higher RANKL/OPG ratio, which correlated with prominent osteoclastogenesis. This work demonstrates that the effects of PD and DM1 enhance bone destruction, confirms the importance of the RANKL signaling pathway in bone destruction in DM1 in animal models and suggests the existence of alternative mechanisms potentiating bone degradation in PD.

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Summary: Neuropathic pain (NP) is a well-recognized feature of leprosy neuropathy. However, the diagnosis of NP is difficult using only clinical criteria. In the study reported here, by means of conventional nerve conduction studies, the authors sought for an association between long-latency responses and NP complaints in leprosy patients with type 1 and 2 reactions. Of the 27 ulnar nerves of leprosy patients, 18 with type 1 reaction (T1R) and 9 with type 2 reaction (T2R) were followed-up for 6 months before and after steroid treatment. Clinical characteristics of pain complaints and clinical function were assessed, as well as the presence of F- and A-waves of the ulnar nerve using nerve conduction studies. The clinical and the neurophysiologic findings were compared to note positive concordances (presence of NP and A-waves together) and negative concordances (absence of NP and A-waves together) before and after treatment. Both reactions presented a high frequency of A-waves (61.1% in T1R and 66.7% in T2R, P < 0.05) and prolonged F-waves (69.4% in T1R and 65.8% in T2R, P = 0.4). No concordances were seen between pain complaints and F-waves. However, significant concordances between NP and A-waves were observed, although restricted to the T2R group ([chi]2 = 5.65, P = 0.04). After treatment, there was a significant reduction in pain complaints, as well as the presence of F- and A-waves in both groups (P < 0.05 for all comparisons). In conclusion, the presence of A-waves correlates well with pain complaints of neuropathic characteristics in leprosy patients, especially in those with type 2 reaction. Probably, such response shares similar mechanisms with the small-fiber dysfunction seen in these patients with NP, such as demyelination, intraneural edema, and axonal sprouting. Further studies using specific tools for small-fiber assessment are warranted to confirm our findings.

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Neurofibromatosis type 1 (NF1) is an autosomal dominant multisystem disorder affecting approximately 1 in 3500 individuals. Patients with the disorder can develop carcinoid tumors, medullary thyroid carcinoma, pheochromocytoma and tumor of the hypothalamus. The association of NF1 with Primary Hyperparathyroidism (HPP) is very rare. We report a 56-year-old woman with NF1 who was referred to our service because of nephrolithiasis. Physical examination revealed the characteristic signs of NF1, and her laboratory calcium profile was compatible with HPP. The patient was referred for parathyroidectomy, but during the surgical work-up she underwent spontaneous remission of her HPP. This case is significant not only for the rarity of this presentation in NF1 patients, but also because of the spontaneous remission of HPP.

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Malignant triton tumor (MTT) is an aggressive peripheral nerve sheath tumor with rhabdomyoblastic differentiation. Less than 100 cases have been described, being mostly male children with type 1 neurofibromatosis. We report a 6-year-old female with MTT and no diagnostic criteria for neurofibromatosis type 1. Cytogenetic analysis showed a 46,X,-X[4]/46,XX[16] karyotype. She underwent a transfemoral amputation and chemotherapy and is free of disease 15 months after diagnosis. The few cytogenetic studies of MTT described in the literature have been inconclusive. Further cytogenetic analyses are needed to understand the role of chromosome X monosomy in the pathogenesis of this rare tumor. Pediatr Blood Cancer 2012; 59: 13201323. (C) 2012 Wiley Periodicals, Inc.

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Leukotrienes (LTs) are lipid mediators involved in several inflammatory disorders. We investigated the LT pathway in human T-lymphotropic virus type 1 (HTLV-1) infection by evaluating LT levels in HTLV-1-infected patients classified according to the clinical status as asymptomatic carriers (HACs) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients. Bioactive LTB4 and CysLTs were both increased in the plasma and in the supernatant of peripheral blood mononuclear cell cultures of HTLV-1-infected when compared to non-infected. Interestingly, CysLT concentrations were increased in HAM/TSP patients. Also, the concentration of plasma LTB4 and LTC4 positively correlated with the HTLV-1 proviral load in HTLV-1-infected individuals. The gene expression levels of LT receptors were differentially modulated in CD4(+) and CD8(+) T cells of HTLV-1-infected patients. Analysis of the overall plasma signature of immune mediators demonstrated that LT and chemokine amounts were elevated during HTLV-1 infection. Importantly, in addition to CysLTs, IP-10 was also identified as a biomarker for HAM/TSP activity. These data suggest that LTs are likely to be associated with HTLV-1 infection and HAM/TSP development, suggesting their putative use for clinical monitoring.

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We report for the first time the genetic and biological characterization of 10 HIV-1 primary isolates representing CRF28_BF and CRF29_BF together with additional unique BF recombinant forms (URFs) obtained by PBMC cocultivation. Recombination is an important factor promoting the increase in the genetic diversity of HIV-1. Notably, more than 20% of HIV-1 sequences worldwide were recombinants. Several recombinant viruses were reported in Brazil, and six circulating recombinant forms (CRFs) have been identified (CRF28_BF, CRF29_BF, CRF31_BC, CRF39_BF, CRF40_BF, and CRF46_BF). CRF28_BF and CRF29_BF were found to infect almost 30% of the patients in Sao Paulo State. The near full-length genomes of these 10 primary isolates were amplified by nested PCR in three overlapping segments, purified, and sequenced. Three samples were related to CRF28_BF, three to CRF29_BF, and four were unique recombinant forms (URFs), as determined by their breakpoint profile determined with the jpHMM program. Additionally, the coreceptor usage of these isolates was investigated in vitro using GHOST assays, which revealed three dual-tropic (X4/R5) viruses, four lymphotropic (X4) viruses, and three macrophage-tropic (R5) viruses with different V3-loop motifs, which challenges the notion that GWGR-carrying viruses are macrophage-tropic only. In sum, we report a much-anticipated well-characterized panel of viruses representing CRF28_BF, CRF29_BF, and URFs from Sao Paulo State, Brazil.

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Objective: To determine the prevalence of patients with type 1 diabetes mellitus who meet the glycemic and cardiovascular (CV) risk factors goals and the frequency of screening for diabetic complications in Brazil according to the American Diabetes Association guidelines. Research design and methods: This was a cross-sectional, multicenter study conducted between December 2008 and December 2010 in 28 public clinics in 20 Brazilian cities. Data were obtained from 1774 adult patients (56.8% females, 57.2% Caucasians) aged 30.3 +/- 9.8 years with diabetes duration of 14.3 +/- 8.8 years. Results: Systolic blood pressure was at goal in 40.3% and diastolic blood pressure was at goal in 26.6% of hypertensive patients. LDL cholesterol and HbA1c were at the goal in 45.2% and 13.2% of the patients, respectively. Overweight was presented in 25.6% and obesity in 6.9%. Among those with more than 5 years of disease, screening for retinopathy was performed in the preceding year in 70.1%. Nephropathy and feet complications were screened in 63.1% and 65.1%, respectively. Conclusions: The majority of patients did not meet metabolic control goals and a substantial proportion was not screened for diabetic complications. These issues may increase the risk of chronic complications and negatively impact public health. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

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Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by T cell-mediated destruction of pancreatic beta cells, resulting in insulin deficiency and hyperglycaemia. Recent studies have described that apoptosis impairment during central and peripheral tolerance is involved in T1D pathogenesis. In this study, the apoptosis-related gene expression in T1D patients was evaluated before and after treatment with high-dose immunosuppression followed by autologous haematopoietic stem cell transplantation (HDI-AHSCT). We also correlated gene expression results with clinical response to HDI-AHSCT. We observed a decreased expression of bad, bax and fasL pro-apoptotic genes and an increased expression of a1, bcl-xL and cIAP-2 anti-apoptotic genes in patients' peripheral blood mononuclear cells (PBMCs) compared to controls. After HDI-AHSCT, we found an up-regulation of fas and fasL and a down-regulation of anti-apoptotic bcl-xL genes expression in post-HDI-AHSCT periods compared to pre-transplantation. Additionally, the levels of bad, bax, bok, fasL, bcl-xL and cIAP-1 genes expression were found similar to controls 2 years after HDI-AHSCT. Furthermore, over-expression of pro-apoptotic noxa at 540 days post-HDI-AHSCT correlated positively with insulin-free patients and conversely with glutamic acid decarboxylase autoantibodies (GAD65) autoantibody levels. Taken together, the results suggest that apoptosis-related genes deregulation in patients' PBMCs might be involved in breakdown of immune tolerance and consequently contribute to T1D pathogenesis. Furthermore, HDI-AHSCT modulated the expression of some apoptotic genes towards the levels similar to controls. Possibly, the expression of these apoptotic molecules could be applied as biomarkers of clinical remission of T1D patients treated with HDI-AHSCT therapy.

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Human T-cell lymphotropic virus type 1 (HTLV-1) is-an RNA virus responsible for diseases such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and adult T-cell leukemia/lymphoma (ATL). Cell-to-cell contact and Tax-induced clonal expansion of infected cells are the main modes of virus replication, making virus detection during the viremic stage difficult. Consequently, the proviral load is the current virologic marker for disease monitoring, but the mechanisms of progression have not been established yet. Thus, this study investigated the presence of virus in plasma from asymptomatic HTLV-1 carriers and from HAM/TSP patients. Real-time PCR was performed on DNA from 150 plasma samples; 12(8%) had detectable DNA amplification, including 6(4%) asymptomatic HTLV-1 carriers and 14(26%) HAM/TSP patients (p < 0.005). Of the 33 samples submitted for nested PCR, six (18%, p = 0.02) were positive for HTLV-1 RNA in the plasma. Additionally, 26 plasma samples were treated with DNAse enzyme to eliminate any DNA contamination before RNA extraction. Two of them (8%) showed amplification for HTLV-1 (p = 0.5). Therefore, this study described for the first time the detection of free HTLV-1 RNA in plasma from HTLV-1-infected subjects, regardless of their clinical status. Thus, HTLV-1 viral replication does occur in plasma, and other transmission pathways for HTLV-1 should be investigated further. (C) 2011 Elsevier B.V. All rights reserved.

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An optimal control strategy for the highly active antiretroviral therapy associated to the acquired immunodeficiency syndrome should be designed regarding a comprehensive analysis of the drug chemotherapy behavior in the host tissues, from major viral replication sites to viral sanctuary compartments. Such approach is critical in order to efficiently explore synergistic, competitive and prohibitive relationships among drugs and, hence, therapy costs and side-effect minimization. In this paper, a novel mathematical model for HIV-1 drug chemotherapy dynamics in distinct host anatomic compartments is proposed and theoretically evaluated on fifteen conventional anti-retroviral drugs. Rather than interdependence between drug type and its concentration profile in a host tissue, simulated results suggest that such profile is importantly correlated with the host tissue under consideration. Furthermore, the drug accumulative dynamics are drastically affected by low patient compliance with pharmacotherapy, even when a single dose lacks. (C) 2012 Elsevier Inc. All rights reserved.

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The tax gene of human T-lymphotropic virus type 1 (HTLV-1) diverges among isolates according to geographic regions and has been classified into two genotypes: taxA and taxB. In Brazil, taxA is the most prevalent genotype in symptomatic and asymptomatic carriers. Few studies have been conducted in HIV-infected patients. The present study characterized the tax gene (1059 bp) in 13 Brazilian HIV-1/HTLV-1-coinfected patients from the south and southeast regions. The results confirmed the transcontinental HTLV-1 subgroup A of the Cosmopolitan subtype and showed high nucleotide similarity both among Brazilian sequences and in relation to the ATK prototype (99.5% and 99.2%, respectively). Six nucleotide substitutions were highly conserved among isolates, ranging from 76.9% to 100%: C7401T, T7914C, C7920T, C7982T, G8231A, and A8367C. The presence of the Brazilian molecular signature of genotype taxA was confirmed in all of the isolates, and they clustered into two Latin American clusters, which confirms the double introduction of HTLV-1 in Brazil.

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Objective: To study the activation of an inflammatory cascade through leukocyte mRNA expression of TLR2, TLR4, MyD88, and pro-inflammatory cytokines in individuals with childhood onset type 1 diabetes. Design and methods: Seventy-six type 1 diabetic patients and 100 normoglycemic subjects (NG) 6 to 20 years old were recruited. Type 1 diabetic patients (DM1) were considered to have good (DM1G) or poor (DM1P) glycemic control according to the values of glycated hemoglobin. TLR2, TLR4, MyD88, interleukin-1 beta (IL-1 beta), IL-6, and tumor necrosis factor alpha (TNF-alpha) mRNA expressions were measured in peripheral blood leukocytes (PBL) by real-time polymerase chain reaction (PCR). Urea, creatinine, albumin, and total protein serum levels were determined. Urinary albumin-to-creatinine ratio (ACR) was calculated. Results: DM1 and DM1P patients showed higher glycated hemoglobin (10 and 11%, respectively) and serum glucose concentrations (208 and 226 mg/ dL, respectively) compared to NG (Glycated hemoglobin: 7% and glucose: 76 mg/ dL) (p < 0.05). PBL mRNA expressions of TLR2, MyD88, IL-1 beta, IL-6, and TNF-alpha were higher in DM1 and TLR2, IL-1 beta, and IL-6 expressions were higher in DMP1 compared to NG (p < 0.05). In DM1, serum albumin and total protein were lower, while serum urea and ACR were higher in comparison to NG (p < 0.05). However, these differences compared to NG were more pronounced in DM1P, which included nine individuals with microalbuminuria. Conclusions: Increased mRNA expression of TLR2, MyD88, and pro-inflammatory cytokines in leukocytes of patients with childhood onset type 1 diabetes indicates the development of a TLR2-mediated pro-inflammatory process, which may also be associated with an early inflammatory process in the kidney and the occurrence of microalbuminuria.

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Hypoglycemia is a well recognized cause of acute symptomatic seizures. The fact that hypoglycemia can cause peripheral neuropathy is less appreciated. We describe a case of insulinoma associated peripheral neuropathy. A 17 year-old previously healthy man was referred for investigation of refractory epilepsy. A history of recurrent seizures, slowly progressive weakness of his feet and hands, and weight gain was obtained. Physical examination showed signs of a chronic sensory-motor polyneuropathy. He was diagnosed with insulinoma and primary hyperparathyroidism, characterizing multiple endocrine neoplasia, type 1 syndrome. Cases of insulinoma associated peripheral neuropathy are very rare. The more characteristic clinical picture appears to be distal weakness, worse in the intrinsic hand and feet muscles, and no or mild sensory signs. Peripheral nervous system symptoms may not completely resolve, despite removal of the cause of hyperinsulinism/hypoglycemia and full reversion of central nervous system symptoms. Mechanisms underlying hypoglycemic neuropathy are still poorly understood. (C) 2011 Elsevier B.V. All rights reserved.

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The midbrain dorsal periaqueductal gray (dPAG) has an important role in orchestrating anxiety-and panic-related responses. Given the cellular and behavioral evidence suggesting opposite functions for cannabinoid type 1 receptor (CB1) and transient receptor potential vanilloid type-1 channel (TRPV1), we hypothesized that they could differentially influence panic-like reactions induced by electrical stimulation of the dPAG. Drugs were injected locally and the expression of CB1 and TRPV1 in this structure was assessed by immunofluorescence and confocal microscopy. The CB1-selective agonist, ACEA (0.01, 0.05 and 0.5 pmol) increased the threshold for the induction of panic-like responses solely at the intermediary dose, an effect prevented by the CB1-selective antagonist, AM251 (75 pmol). Panicolytic-like effects of ACEA at the higher dose were unmasked by pre-treatment with the TRPV1 antagonist capsazepine (0.1 nmol). Similarly to ACEA, capsazepine (1 and 10 nmol) raised the threshold for triggering panic-like reactions, an effect mimicked by another TRPV1 antagonist, SB366791 (1 nmol). Remarkably, the effects of both capsazepine and SB366791 were prevented by AM251 (75 pmol). These pharmacological data suggest that a common endogenous agonist may have opposite functions at a given synapse. Supporting this view, we observed that several neurons in the dPAG co-expressed CB1 and TRPV1. Thus, the present work provides evidence that an endogenous substance, possibly anandamide, may exert both panicolytic and panicogenic effects via its actions at CB1 receptors and TRPV1 channels, respectively. This tripartite set-point system might be exploited for the pharmacotherapy of panic attacks and anxiety-related disorders. Neuropsychopharmacology (2012) 37, 478-486; doi:10.1038/npp.2011.207; published online 21 September 2011