156 resultados para Early-emerging genotype
Resumo:
In this study, morphological changes in the optic nerve were determined by light microscopy in Wistar rats on an iron-deficient diet for 32 days or for 21 days followed by 10 days on an iron-recovery diet. The morphometric findings showed significantly fewer blood vessels and oligodendrocytes in the iron-deficient rats and iron-recovery rats than in the control group, as well as more astrocytes in the iron-recovery rats. Serum iron levels of the iron-deficient rats were significantly lower than those of the controls. On the other hand, iron-recovery rats had normal serum iron levels, but no change in the abnormal morphology of the myelinated axons and morphometric parameters. Our data indicate that iron is necessary for maintenance of the optic nerve cell structure, and morphological damage from iron-deficiency is not easily reverted by iron reposition.
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Folic acid (FA) supplementation during carcinogenesis is controversial. Considering the impact of liver cancer as a public health problem and mandatory FA fortification in several countries, the role of FA supplementation in hepatocarcinogenesis should be elucidated. We evaluated FA supplementation during early hepatocarcinogenesis. Rats received daily 0.08 mg (FA8 group) or 0.16 mg (FA16 group) of FA/100 g body weight or water (CO group, controls). After a 2-week treatment, animals were subjected to the ""resistant hepatocyte"" model of hepatocarcinogenesis (initiation with diethylnitrosamine, selection/promotion with 2-acetylaminofluorene and partial hepatectomy) and euthanized after 8 weeks of treatment. Compared to the CO group, the FA16 group presented: reduced (p < 0.05) number of persistent and increased (p < 0.05) number of remodeling glutathione S-transferase (GST-P) positive preneoplastic lesions (PNL); reduced (p < 0.05) cell proliferation in persistent GST-P positive PNL; decreased (p < 0.05) hepatic DNA damage; and a tendency (p < 0.10) for decreased c-myc expression in microdissected PNL. Regarding all these parameters, no differences (p > 0.05) were observed between CO and FA8 groups. FA-treated groups presented increased hepatic levels of S-adenosylmethionine but only FA16 group presented increased S-adenosylmethionine/S-adenosylhomocysteine ratio. No differences (p > 0.05) were observed between experimental groups regarding apoptosis in persistent and remodeling GST-P positive PNL, and global DNA methylation pattern in microdissected PNL. Altogether, the FA16 group, but not the FA8 group, presented chemopreventive activity. Reversion of PNL phenotype and inhibition of DNA damage and of c-myc expression represent relevant FA cellular and molecular effects.
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Since circulating leukocytes, mainly B and T cells, continuously maintain vigilant and comprehensive immune surveillance, these cells could be used as reporters for signs of infection or other pathologies, including cancer. Activated lymphocyte clones trigger a sensitive transcriptional response, which could be identified by gene expression profiling. To assess this hypothesis, we conducted microarray analysis of the gene expression profile of lymphocytes isolated from immunocompetent BALB/c mice subcutaneously injected with different numbers of tumorigenic B61 fibrosarcoma cells. Flow cytometry demonstrated that the number of circulating T (CD3(+)CD4(+) or CD3(+)CD8(+)) or B (CD19(+)) cells did not change. However, the lymphocytes isolated from tumor cell-injected animals expressed a unique transcriptional profile that was identifiable before the development of a palpable tumor mass. This finding demonstrates that the transcriptional response appears before alterations in the main lymphocyte subsets and that the gene expression profile of peripheral lymphocytes can serve as a sensitive and accurate method for the early detection of cancer. Exp Biol Med 234:802-812, 2009
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Background: Environmental factors may influence the development of allergen sensitization and asthma. The aim of this study was to evaluate the role of endotoxin and allergen exposure in early life as a risk factor for recurrent wheezing. Methods: One hundred and four infants from low-income families, at high risk of asthma, were enrolled at birth. Dust samples were collected from the bedding and bedroom floor within 6 months after birth. Recurrent wheezing was defined as 3 or more wheezing episodes in the past year. Endotoxin was determined by Limulus amebocyte lysate assay, and major indoor allergens were quantitated by ELISA in dust extracts. IgE antibodies were measured by ImmunoCAP at 30 months of age. Results: At 30 months, 51 of the 99 infants who completed the study (51.5%) had recurrent wheezing. Respiratory infection was strongly associated with recurrent wheezing (OR 6.67, 95% CI 1.96-22.72), whereas exclusive breastfeeding for at least 1 month was a protective factor (OR 0.09, 95% CI 0.01-0.51). Exposure to high levels of mouse allergen was more frequent among non-recurrent wheezers, approaching significance (OR 0.12, 95% CI 0.01-1.13; p=0.064). None of the children were sensitized to mouse. Sensitization to mite was found in 26/90 (28.8%) children, with no association with recurrent wheezing. Conclusion: Respiratory infection was strongly associated with recurrent wheezing in the first 30 months of life, in children at high risk of asthma, living in a socially deprived community in Brazil. Copyright (C) 2009 S. Karger AG, Basel
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Type 1 diabetes mellitus (T1DM) is the result of the autoimmune response against pancreatic insulin producing cells. This autoimmune response begins months or even years before the first presentation of signs and symptoms of hyperglycemia and at the time of clinical diagnosis near 30% of -cell mass still remains. In daily clinical practice, the main therapeutic option for T1DM is multiple subcutaneous insulin injections that are shown to promote tight glucose control and reduce much of diabetic chronic complications, especially microvascular complications. Another important aspect related to long-term complications of diabetes is that patients with initially larger -cell mass suffer less microvascular complications and less hypoglycemic events than those patients with small -cell mass. In face of this, -cell preservation is another important target in the management of type 1 diabetes and its related complications. For many years, various immunomodulatory regimens were tested aiming at blocking autoimmunity against -cell mass and at promoting -cell preservation, mainly in secondary prevention trials. In this review, we summarize some of the most important studies involving -cell preservation by immunomodulation and discuss our preliminary data on autologous nonmyeloablative hematopoietic stem cell transplantation in newly-diagnosed T1DM.
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Aims: To evaluate the C-reactive protein (CRP) and interleukin-6 (IL-6) as diagnostic tools for early onset infection in preterm infants with early respiratory distress (RD). Methods: CRP and IL-6 were quantified at identification of RD and 24 h after in 186 newborns. Effects of maternal hypertension, mode of delivery, Apgar score, birth weight, gestational age, mechanical ventilation, being small for gestational age (SGA), and the presence of infection were analyzed. Results: Forty-four infants were classified as infected, 42 as possibly infected, and 100 as uninfected. Serum levels of IL-6 (0 h), CRP (0 h), and CRP (24 h), but not IL-6 (24 h) were significantly higher in infected infants compared to the remaining groups. The best test for identification of infection was the combination of IL-6 (0 h) 36 pg/dL and/or CRP (24 h) 0.6 mg/dL, which yielded 93% sensitivity and 37% specificity. The presence of infection and vaginal delivery independently increased IL-6 (0 h), CRP (0 h) and CRP (24 h) levels. Being SGA also increased the CRP (24 h) levels. IL-6 (24 h) was independently increased by mechanical ventilation. Conclusions: The combination of IL-6 (0 h) and/or CRP (24 h) is helpful for excluding early onset infection in preterm infants with RD but the poor specificity limits its potential benefit as a diagnostic tool.
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The fact that the diagnosis of infection with dengue virus is usually made by detecting IgM antibodies during the convalescent phase of the disease interferes with disease management and, consequently, with reducing mortality rates. This study evaluated the sensitivity and specificity of detection of NS1 in samples of patients suspected of acute dengue virus infection in Brazil. The results were used to institute treatment and the sensitivity and specificity of detection of NS1 were compared to the results of detection of IgM, virus isolation, and RT-PCR. Detection of NS1 yielded better results than RTPCR and virus isolation. When considering IgM detection and RT-PCR positive results as ""gold standards,"" the sensitivity and specificity of the NS1 assay were 95.9% and 81.1%, respectively. All patients enrolled in the study were treated promptly and had an uneventful course of the disease. The detection of NS1 provided better results than the diagnostic techniques used currently during the acute phase of disease (RT-PCR and virus isolation). Detection of NS1 is an important tool for the diagnosis of acute dengue infection, particularly in highly endemic areas, allowing for rapid treatment of patients and reduction of disease burden. J. Med. Virol. 82: 1400-1405, 2010. (C) 2010 Wiley-Liss, Inc.
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Context: Mutations in TAC3 and TACR3 (encoding neurokinin B and its receptor) have been identified in Turkish patients with idiopathic hypogonadotropic hypogonadism (IHH), but broader populations have not yet been tested and genotype-phenotype correlations have not been established. Objective: A broad cohort of normosmic IHH probands was screened for mutations in TAC3/TACR3 to evaluate the prevalence of such mutations and define the genotype/phenotype relationships. Design and Setting: The study consisted of sequencing of TAC3/TACR3, in vitro functional assays, and neuroendocrine phenotyping conducted in tertiary care centers worldwide. Patients or Other Participants: 345 probands, 18 family members, and 292 controls were studied. Intervention: Reproductive phenotypes throughout reproductive life and before and after therapy were examined. Main Outcome Measure: Rare sequence variants in TAC3/TACR3 were detected. Results: In TACR3, 19 probands harbored 13 distinct coding sequence rare nucleotide variants [three nonsense mutations, six nonsynonymous, four synonymous (one predicted to affect splicing)]. In TAC3, one homozygous single base pair deletion was identified, resulting in complete loss of the neurokinin B decapeptide. Phenotypic information was available on 16 males and seven females with coding sequence variants in TACR3/TAC3. Of the 16 males, 15 had microphallus; none of the females had spontaneous thelarche. Seven of the 16 males and five of the seven females were assessed after discontinuation of therapy; six of the seven males and four of the five females demonstrated evidence for reversibility of their hypogonadotropism. Conclusions: Mutations in the neurokinin B pathway are relatively common as causes of hypogonadism. Although the neurokinin B pathway appears essential during early sexual development, its importance in sustaining the integrity of the hypothalamic-pituitary-gonadal axis appears attenuated over time. (J Clin Endocrinol Metab 95: 2857-2867, 2010)
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Chagas disease is a chronic, systemic, parasitic infection caused by the protozoan Trypanosoma cruzi, and was discovered in 1909. The disease affects about 8 million people in Latin America, of whom 30-40% either have or will develop cardiomyopathy, digestive megasyndromes, or both. In the past three decades, the control and management of Chagas disease has undergone several improvements. Large-scale vector control programmes and screening of blood donors have reduced disease incidence and prevalence. Although more effective trypanocidal drugs are needed, treatment with benznidazole (or nifurtimox) is reasonably safe and effective, and is now recommended for a widened range of patients. Improved models for risk stratification are available, and certain guided treatments could halt or reverse disease progression. By contrast, some challenges remain: Chagas disease is becoming an emerging health problem in non-endemic areas because of growing population movements; early detection and treatment of asymptomatic individuals are underused; and the potential benefits of novel therapies (eg, implantable cardioverter defibrillators) need assessment in prospective randomised trials.
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To better understand the early events regulating lineage-specific hematopoietic differentiation, we analyzed the transcriptional profiles of CD34+ human hematopoietic stem and progenitor cells (HSPCs) subjected to differentiation stimulus. CD34+ cells were cultured for 12 and 40 h in liquid cultures with supplemented media favoring myeloid or erythroid commitment. Serial analysis of gene expression (SAGE) was employed to generate four independent libraries. By analyzing the differentially expressed regulated transcripts between the un-stimulated and the stimulated CD34+ cells, we observed a set of genes that was initially up-regulated at 12 h but were then down-regulated at 40 h, exclusively after myeloid stimulus. Among those we found transcripts for NFKB2, RELB, IL1B, LTB, LTBR, TNFRSF4, TGFB1, and IKBKA. Also, the inhibitor NFKBIA (IKBA) was more expressed at 12 h. All those transcripts code for signaling proteins of the nuclear factor kappaB pathway. NFKB2 is a subunit of the NF-kappa B transcription factor that with RELB mediates the non-canonical NF-kappa B pathway. Interference RNA (RNAi) against NFKB1, NFKB2 and control RNAi were transfected into bone marrow CD34+HSPC. The percentage and the size of the myeloid colonies derived from the CD34+ cells decreased after inhibition of NFKB2. Altogether, our results indicate that NFKB2 gene has a role in the early commitment of CD34+HSPC towards the myeloid lineage. (C) 2010 International Society of Differentiation. Published by Elsevier Ltd. All rights reserved.
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Objective: The etiology of cutaneous melanoma is complex, involving both heterogeneous genetic and environmental components. The aim of our study was to verify if single polymorphic sites within IGF2 and H19 genes and their consequent haplotypes influence risk and/or prognosis of familial melanoma. Design: Twenty one patients with clinical criteria of hereditary melanoma (early onset, presence of multiple primary melanoma, and/or one or more affected first- or second-degree relatives) and previously screened for CDKN2A mutations were genotyped by IGF2/ApaI and H19/RsaI PCR-RFLPs. Data were compared between patients and a control group (100 healthy young individuals) using Chi-square and Fisher`s exact tests. We also investigated if these polymorphic sites could be microRNAs potential targets, using RegRNA software. Results: Although the IGF2 and HI9 genotypes/haplotypes were not significantly associated with melanoma, two of the most severe cases (very early onset or multiple melanomas) showed to be heterozygous for both genes. We found an overlap between IGF2/ApaI and miR-615-5p, and between H19/RsaI and miR-574-3p. Conclusions: Some studies have shown H19, and IGF2 genes (or related genes or protein, for example, IGF2R and IMP-3) differential expression in melanoma. However, no study has attempted to examine markers across this cluster in relation to melanoma until now. Since the base change may impair the pairing of microRNA and its binding site, our results suggest a new window for future studies of IGF2 and H19 genetic variability and posttranscriptional regulation. Due to the importance and based on the present results, we suggest that the genotype/haplotype analysis of IGF2 and H19 polymorphisms should be better investigated in large populations with cutaneous melanoma, attempting to tie the association with progression of the disease. (C) 2010 Growth Hormone Research Society. Published by Elsevier Ltd. All rights reserved.
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Werner syndrome (WS) is a premature aging disorder characterized by early onset of symptoms related to normal aging and by a high predisposition to various types of cancer, including gliomas. WS is caused by inherited recessive mutations in the WRN gene, which encodes a helicase considered a caretaker of the genome. Aiming to study the role of WRN Cys1367Arg in glioma susceptibility and oncologic prognosis of patients, we investigated the genotype distribution of this single nucleotide polymorphism in 94 glioma patients and 100 healthy subjects. Comparisons of genotype distributions and allele frequencies did not reveal any significant difference between the groups. Overall and disease-free survival rates were calculated, but no statistically significant difference was observed. Our data suggest that WRN Cys1367Arg SNP is not involved either in susceptibility to developing gliomas or in patient survival, at least in the Brazilian population.
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von Hippel-Lindau (VHL) disease is an autosomal dominant hereditary cancer syndrome that predisposes to the development of a variety of benign and malignant tumours, especially cerebellar haemangioblastomas, retinal angiomas and clear-cell renal cell carcinomas (RCC). The etiology and manifestations are due to germline and somatic mutations in the VHL tumour suppressor gene. VHL disease is classified into type 1 and type 2, showing a clear genotype-phenotype correlation, as type 2 is associated with phaeochromocytoma and essentially caused by missense mutations. The aim of this study is to characterize the phenotype and genotype of families with VHL disease. Eighteen of twenty patients from ten unrelated families underwent genetic testing, nine of them fulfilled VHL disease criteria and one had an apparently sporadic cerebellar haemangioblastoma. Four different germline mutations in the VHL gene were identified: c.226_228delTTC (p.Phe76del); c.217C > T (p.Gln73X); IVS1-1 G > A and IVS2-1 G > C. The first three mutations were associated with type 1 disease and the last one with type 2B, which had never been identified in the germline. The transcriptional processing of a novel splice-site mutation was characterised. Three type 1 VHL families showed large deletions of the VHL gene, two of them encompassed the FANCD2/C3orf10 genes and were not associated with renal lesions. We also suggest that such families should be subclassified according to the risk of RCC and the extent of the VHL gene deletions. This study highlights the need for a through clinical and molecular characterisation of families with VHL disease to better delineate its genotype-phenotype correlation.
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Objective: To assess whether the -11391G > A polymorphism in the regulatory region of the adiponectin gene (ADIPOQ) is associated with birth size, postnatal growth, adiponectinemia, and cardiometabolic risk in adult life. Design: Case-control study nested within a prospective cohort of 2063 community subjects born in 1978/1979 and followed since birth to date. Methods: ADIPOQ -11391G > A genotype-phenotype associations were evaluated in 116 subjects born large for gestational age (LGA) and 392 gender-matched controls at birth (birth size), at 8-10 years (catch-down growth), and at 23-25 years of age (cardiometabolic profile). Results: The -11391A variant allele frequency was higher in LGA subjects (P=0.04). AA genotype was associated with augmented probability of being born LGA (odds ratio=4.14; 95% confidence interval: 1.16-16.7; P=0.03). This polymorphism was associated neither with body composition nor with postnatal growth pattern. At the age of 23-25 years, the -11391A variant allele was associated with higher serum adiponectin levels (GG: 10.7 +/- 6.2 versus GA: 12.2 +/- 6.5 versus AA: 14.2 +/- 6.8 mu g/ml; P < 0.01). Subjects born LGA presented higher body mass index (BMI; P=0.01), abdominal circumference (P=0.04), blood pressure (P=0.04), and homeostasis assessment model for insulin resistance (P=0.01) than adequate for gestational age. Symmetry at birth did not influence these variables. The occurrence of catch-down of weight was associated with lower BMI and abdominal circumference (P < 0.001) at 23-25 years. Conclusions: The -11391A ADIPOQ gene variant was associated with increased chance of being born LGA and with higher adiponectin levels in early adult life.
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The identification of early markers that predict the response to anti-tuberculosis treatment would facilitate evaluation of new drugs and improve patient management. This study aimed to determine whether selected acute phase proteins and micronutrients measured at the time of diagnosis and during the first weeks of treatment could predict treatment responses during the 2-month standard intensive phase of therapy. For this purpose, alpha 1-antitrypsin, alpha 1-acid gtycoprotein, alpha 2-macroglobutin, C-reactive protein, C3, C4, zinc, copper and selenium concentrations were measured in Brazilian patients with smear-positive tuberculosis at the time of diagnosis and 1, 3, 5 and 8 weeks after initiation of therapy. Patients were classified into fast (n = 29), intermediate (n = 18) and slow responders (n = 10) if they were smear-negative at 3, 5 or 8 weeks of treatment. alpha 1-acid gtycoprotein on enrolment and 1 week of treatment, alpha 1-antitrypsin at week 1 and C-reactive protein and C3 after 3 weeks of therapy were higher in slow responders than in fast responders. alpha 1-antitrypsin and alpha 1-acid glycoprotein may be helpful in predicting treatment response at the time of initiation of therapy, and could be used as early markers to identify patients with an increased likelihood of treatment failure. (C) 2008 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.