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AIM: The aim of this study was the assessment of the anatomical thickness of danger zone in the cervical third of mesial canals of mandibular molars. MATERIALS AND METHODS: Fifty mandibular molars were selected and scanned with cone-beam computed tomography. Data were compared using a length tool provided by scanner software. The measured areas were the mesial and distal walls of the cervical third of the mesial roots, which correspond to the safety and danger zones, respectively. In addition, dentin thickness at the furcation was evaluated. RESULTS: Dentin thicknesses of the safety zone were higher than in the danger zone in all teeth examined. The thinnest dentin of the safety zone was found at a point located 4 mm below the canal orifice, with a mean value of 1.03 mm; conversely, in the danger zone, the thinnest point was located 3 mm below the orifice, with a mean value of 0.81 mm. As for the distance from the pulp chamber floor to the furcation, the average value was 2.23 mm. CONCLUSION: These results show that mean thicknesses at the danger zone of mandibular molar mesial roots were <1.0 mm. These data reinforce the importance of understanding anatomy and the need for conservative preparations when assessing and instrumenting these root canals.
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Atypical hemolytic uremic syndrome (aHUS) and C3 glomerulopathy (C3G) are associated with dysregulation and overactivation of the complement alternative pathway. Typically, gene analysis for aHUS and C3G is undertaken in small patient numbers, yet it is unclear which genes most frequently predispose to aHUS or C3G. Accordingly, we performed a six-center analysis of 610 rare genetic variants in 13 mostly complement genes (CFH, CFI, CD46, C3, CFB, CFHR1, CFHR3, CFHR4, CFHR5, CFP, PLG, DGKE, and THBD) from >3500 patients with aHUS and C3G. We report 371 novel rare variants (RVs) for aHUS and 82 for C3G. Our new interactive Database of Complement Gene Variants was used to extract allele frequency data for these 13 genes using the Exome Aggregation Consortium server as the reference genome. For aHUS, significantly more protein-altering rare variation was found in five genes CFH, CFI, CD46, C3, and DGKE than in the Exome Aggregation Consortium (allele frequency < 0.01%), thus correlating these with aHUS. For C3G, an association was only found for RVs in C3 and the N-terminal C3b-binding or C-terminal nonsurface-associated regions of CFH In conclusion, the RV analyses showed nonrandom distributions over the affected proteins, and different distributions were observed between aHUS and C3G that clarify their phenotypes.
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Síndrome Hemolítico-Urêmica Atípica/genética , Complemento C3/genética , Fator H do Complemento/genética , Via Alternativa do Complemento/genética , Glomerulonefrite Membranoproliferativa/genética , Síndrome Hemolítico-Urêmica Atípica/patologia , Complemento C3/metabolismo , Via Alternativa do Complemento/fisiologia , Feminino , Frequência do Gene/genética , Predisposição Genética para Doença/genética , Glomerulonefrite Membranoproliferativa/patologia , Humanos , Masculino , Mutação de Sentido Incorreto/genéticaRESUMO
IgA nephropathy (IgAN), a frequent cause of chronic kidney disease worldwide, is characterized by mesangial deposition of galactose-deficient IgA1-containing immune complexes. Complement involvement in IgAN pathogenesis is suggested by the glomerular deposition of complement components and the strong protection from IgAN development conferred by the deletion of the CFHR3 and CFHR1 genes (ΔCFHR3-CFHR1). Here we searched for correlations between clinical progression and levels of factor H (FH) and FH-related protein 1 (FHR-1) using well-characterized patient cohorts consisting of 112 patients with IgAN, 46 with non-complement-related autosomal dominant polycystic kidney disease (ADPKD), and 76 control individuals. Patients with either IgAN or ADPKD presented normal FH but abnormally elevated FHR-1 levels and FHR-1/FH ratios compared to control individuals. Highest FHR-1 levels and FHR-1/FH ratios are found in patients with IgAN with disease progression and in patients with ADPKD who have reached chronic kidney disease, suggesting that renal function impairment elevates the FHR-1/FH ratio, which may increase FHR-1/FH competition for activated C3 fragments. Interestingly, ΔCFHR3-CFHR1 homozygotes are protected from IgAN, but not from ADPKD, and we found five IgAN patients with low FH carrying CFH or CFI pathogenic variants. These data support a decreased FH activity in IgAN due to increased FHR-1/FH competition or pathogenic CFH variants. They also suggest that alternative pathway complement activation in patients with IgAN, initially triggered by galactose-deficient IgA1-containing immune complexes, may exacerbate in a vicious circle as renal function deterioration increase FHR-1 levels. Thus, a role of FHR-1 in IgAN pathogenesis is to compete with complement regulation by FH.
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Proteínas Inativadoras do Complemento C3b/análise , Via Alternativa do Complemento/genética , Glomerulonefrite por IGA/sangue , Rim Policístico Autossômico Dominante/sangue , Insuficiência Renal Crônica/sangue , Adulto , Proteínas Sanguíneas/genética , Estudos de Coortes , Proteínas Inativadoras do Complemento C3b/genética , Fator H do Complemento/análise , Fator H do Complemento/genética , Progressão da Doença , Feminino , Taxa de Filtração Glomerular , Glomerulonefrite por IGA/genética , Humanos , Masculino , Pessoa de Meia-Idade , Rim Policístico Autossômico Dominante/genética , Insuficiência Renal Crônica/genética , Adulto JovemRESUMO
Introduction: Cervical preflaring is an important step of the canal system instrumentation, but can lead to excessive enlargement or root perforation. Objective: Evaluate the remaining dentin thickness in the mandibular molars of mesial roots using cone beam computed tomography: Gates-Glidden (crown-down); Gates-Glidden (step-back); LA Axxess and Easy Pro-Design. Material and method: Were selected 40 lower molars mesial roots, which were scanned in a cone beam CT scanner before and after preparation. Were obtained five sections of the CT images with an interval of 1 mm from the furcation, and measured the thickness variation between the root canal to the root external portion in analysis software. Result: The evaluation of the different levels showed no significance within the same group for the Gates-Glidden group. On the other hand, were observed difference for LA Axxess (p=0.002) and Easy Pro-Design (p=0.005). In the intergroup analysis, were observed difference in all levels, especially for Gates-Glidden in the ascendant order (ANOVA and Tukey). Conclusion: Within the limitations of these study, is possible to conclude that the protocol with greater wear in the cervical risk area was the Gates-Glidden in step-back sequence, as the other groups were equivalent (p>0.05).
Introdução: O preparo cervical é uma etapa importante da instrumentação do sistema de canais, mas pode levar ao alargamento excessivo ou rasgo da raiz. Objetivo: Avaliar, em tomografia computadorizada cone beam, da espessura remanescente de dentina cervical da raiz mesial de molares inferiores, após o preparo com diferentes técnicas: Gates-Glidden (ordem crescente); Gates-Glidden (ordem decrescente); LA Axxess e Easy Pro-Design. Material e método: Foram selecionadas 40 raízes mesiais de molares inferiores, que foram escaneadas em tomógrafo cone beam antes e após o preparo. Das imagens tomográficas foram obtidos cinco cortes com intervalo de 1 mm a partir da furca e, então, mensurada a variação da espessura entre o canal radicular até a porção externa da raiz em software de análise. Resultado: Avaliação dos diferentes níveis demonstraram ausência de significância dentro do mesmo grupo para o grupo das Gates-Glidden. Por outro lado, foi notada diferença para LA Axxess (p=0,002) e para Easy Pro-Design (p=0,005). Na avaliação entre os grupos, foi observada diferença em todos os níveis, sobretudo, para Gates-Glidden na ordem crescente (ANOVA e Tukey). Conclusão: Considerando as limitações desse estudo, concluiu-se que o protocolo que apresentou maior desgaste da área de perigo cervical foi o da Gates-Glidden em ordem crescente, sendo que os demais grupos foram equivalentes (p>0,05).
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Raiz Dentária , Análise de Variância , Preparo de Canal Radicular , Instrumentos Odontológicos , Dentina , Tomografia Computadorizada de Feixe Cônico , Dente MolarRESUMO
The complement factor H (FH) mutation R1210C, which was described in association with atypical hemolytic uremic syndrome (aHUS), also confers high risk of age-related macular degeneration (AMD) and associates with C3 glomerulopathy (C3G). To reveal the molecular basis of these associations and to provide insight into what determines the disease phenotype in FH-R1210C carriers, we identified FH-R1210C carriers in our aHUS, C3G, and AMD cohorts. Disease status, determined in patients and relatives, revealed an absence of AMD phenotypes in the aHUS cohort and, vice versa, a lack of renal disease in the AMD cohort. These findings were consistent with differences in the R1210C-independent overall risk for aHUS and AMD between mutation carriers developing one pathology or the other. R1210C is an unusual mutation that generates covalent complexes between FH and HSA. Using purified FH proteins and surface plasmon resonance analyses, we demonstrated that formation of these FH-HSA complexes impairs accessibility to all FH functional domains. These data suggest that R1210C is a unique C-terminal FH mutation that behaves as a partial FH deficiency, predisposing individuals to diverse pathologies with distinct underlying pathogenic mechanisms; the final disease outcome is then determined by R1210C-independent genetic risk factors.
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Síndrome Hemolítico-Urêmica Atípica/genética , Complemento C3 , Nefropatias/genética , Glomérulos Renais , Degeneração Macular/genética , Mutação , Fator H do Complemento/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , LinhagemRESUMO
Atypical hemolytic uremic syndrome (aHUS) is a severe thrombotic microangiopathy affecting the renal microvasculature and is associated with complement dysregulation caused by mutations or autoantibodies. Disease penetrance and severity is modulated by inheritance of "risk" polymorphisms in the complement genes MCP, CFH and CFHR1. We describe the prevalence of mutations, the frequency of risk polymorphisms and the occurrence of anti-FH autoantibodies in a Spanish aHUS cohort (n=367). We also report the identification of a polymorphism in CFHR3 (c.721C>T; rs379370) that is associated with increased risk of aHUS (OR=1.78; CI 1.22-2.59; p=0.002), and is most frequently included in an extended risk haplotype spanning the CFH-CFHR3-CFHR1 genes. This extended haplotype integrates polymorphisms in the promoter region of CFH and CFHR3, and is associated with poorer evolution of renal function and decreased FH levels. The CFH-CFHR3-CFHR1 aHUS-risk haplotype seems to be the same as was previously associated with protection against meningococcal infections, suggesting that the genetic variability in this region is limited to a few extended haplotypes, each with opposite effects in various human diseases. These results suggest that the combination of quantitative and qualitative variations in the complement proteins encoded by CFH, CFHR3 and CFHR1 genes is key for the association of these haplotypes with disease.
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Síndrome Hemolítico-Urêmica Atípica/genética , Proteínas Sanguíneas/genética , Proteínas Inativadoras do Complemento C3b/genética , Fator H do Complemento/genética , Predisposição Genética para Doença , Variação Genética , Haplótipos/genética , Adolescente , Adulto , Anticorpos/imunologia , Sequência de Bases , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Rim/patologia , Rim/fisiopatologia , Masculino , Dados de Sequência Molecular , Mutação , Taxa de Mutação , Penetrância , Polimorfismo de Nucleotídeo Único/genética , Prevalência , Fatores de Risco , Espanha , Adulto JovemRESUMO
BACKGROUND: Glomerulonephritis is one of the most severe complications of lupus, a systemic disease with multi-organ involvement, with tissue damage produced mainly by complement activation. As a result of this activation, patients with active lupus present hypocomplementemia during disease flares, but C3 and C4 levels are recovered between episodes. CASE PRESENTATION: We present a patient who suffered two lupus nephritis episodes in 5 years, achieving complete remission with treatment after both of them, but with C3 levels persistently below normal range. Genetic study revealed that the patient carried a mutation in heterozygosis in the C3 gene. Serial sera samples were analyzed, and autoantibodies to complement alternative pathway proteins (Factor I, Factor B, C3 and Properdin) were found. Functional assays showed that these autoantibodies cause alternative pathway activation. CONCLUSION: This case is the first reported of a heterozygous C3 mutation associated with lupus nephritis and autoantibodies against complement alternative pathway proteins (Factor I, Factor B, C3 and Properdin).These autoantibodies cause activation of this pathway and this fact could explain that the tissue damage is restricted to the kidney.
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Autoanticorpos/imunologia , Complemento C3/genética , Rim/patologia , Nefrite Lúpica/genética , Complemento C3/imunologia , Fator B do Complemento/imunologia , Feminino , Fibrinogênio/imunologia , Heterozigoto , Humanos , Nefrite Lúpica/imunologia , Nefrite Lúpica/patologia , Mutação , Properdina/imunologia , Adulto JovemRESUMO
Atypical hemolytic uremic syndrome (aHUS) associates with complement dysregulation caused by mutations and polymorphisms in complement activators and regulators. However, the reasons why some mutations in complement proteins predispose to aHUS are poorly understood. Here, we have investigated the functional consequences of three aHUS-associated mutations in C3, R592W, R161W and I1157T. First, we provide evidence that penetrance and disease severity for these mutations is modulated by inheritance of documented "risk" haplotypes as has been observed with mutations in other complement genes. Next, we show that all three mutations markedly reduce the efficiency of factor I-mediated C3b cleavage when catalyzed by membrane cofactor protein (MCP), but not when catalyzed by factor H. Biacore analysis showed that each mutant C3b bound sMCP (recombinant soluble MCP; CD46) at reduced affinity, providing a molecular basis for its reduced cofactor activity. Lastly, we show by electron microscopy structural analysis a displacement of the TED domain from the MG ring in C3b in two of the C3 mutants that explains these defects in regulation. As a whole our data suggest that aHUS-associated mutations in C3 selectively affect regulation of complement on surfaces and provide a structural framework to predict the functional consequences of the C3 genetic variants found in patients.
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Síndrome Hemolítico-Urêmica Atípica/genética , Complemento C3/genética , Predisposição Genética para Doença , Proteína Cofatora de Membrana/genética , Mutação , Adolescente , Adulto , Síndrome Hemolítico-Urêmica Atípica/imunologia , Síndrome Hemolítico-Urêmica Atípica/patologia , Sequência de Bases , Sítios de Ligação , Criança , Complemento C3/química , Complemento C3/imunologia , Fator H do Complemento/genética , Fator H do Complemento/imunologia , Feminino , Fibrinogênio/genética , Fibrinogênio/imunologia , Expressão Gênica , Haplótipos , Humanos , Masculino , Proteína Cofatora de Membrana/imunologia , Modelos Moleculares , Dados de Sequência Molecular , Ligação Proteica , Estrutura Terciária de Proteína , Proteólise , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Índice de Gravidade de DoençaRESUMO
BACKGROUND AND OBJECTIVES: Atypical hemolytic uremic syndrome is characterized by vascular endothelial damage caused by complement dysregulation. Consistently, complement inhibition therapies are highly effective in most patients with atypical hemolytic uremic syndrome. Recently, it was shown that a significant percentage of patients with early-onset atypical hemolytic uremic syndrome carry mutations in diacylglycerol kinase-ε, an intracellular protein with no obvious role in complement. These data support an alternative, complement-independent mechanism leading to thrombotic microangiopathy that has implications for treatment of early-onset atypical hemolytic uremic syndrome. To get additional insights into this new form of atypical hemolytic uremic syndrome, the diacylglycerol kinase-ε gene in a cohort with atypical hemolytic uremic syndrome was analyzed. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Eighty-three patients with early-onset atypical hemolytic uremic syndrome (<2 years) enrolled in the Spanish atypical hemolytic uremic syndrome registry between 1999 and 2013 were screened for mutations in diacylglycerol kinase-ε. These patients were also fully characterized for mutations in the genes encoding factor H, membrane cofactor protein, factor I, C3, factor B, and thrombomodulin CFHRs copy number variations and rearrangements, and antifactor H antibodies. RESULTS: Four patients carried mutations in diacylglycerol kinase-ε, one p.H536Qfs*16 homozygote and three compound heterozygotes (p.W322*/p.P498R, two patients; p.Q248H/p.G484Gfs*10, one patient). Three patients also carried heterozygous mutations in thrombomodulin or C3. Extensive plasma infusions controlled atypical hemolytic uremic syndrome recurrences and prevented renal failure in the two patients with diacylglycerol kinase-ε and thrombomodulin mutations. A positive response to plasma infusions and complement inhibition treatment was also observed in the patient with concurrent diacylglycerol kinase-ε and C3 mutations. CONCLUSIONS: Data suggest that complement dysregulation influences the onset and disease severity in carriers of diacylglycerol kinase-ε mutations and that treatments on the basis of plasma infusions and complement inhibition are potentially useful in patients with combined diacylglycerol kinase-ε and complement mutations. A comprehensive understanding of the genetic component predisposing to atypical hemolytic uremic syndrome is, therefore, critical to guide an effective treatment.
Assuntos
Síndrome Hemolítico-Urêmica Atípica/genética , Proteínas do Sistema Complemento/genética , Diacilglicerol Quinase/genética , Mutação , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , LinhagemRESUMO
Hemolytic uremic syndrome (HUS) is a rare, life-threatening disease characterized by thrombocytopenia, microangiopathic hemolytic anemia, and acute renal failure. The atypical form of HUS (aHUS), representing 5 to 10% of cases, lacks the association with infection by Shiga toxin producing Escherichia coli strains that characterizes the commonest clinical presentation of HUS. In the majority of aHUS cases, the disease results from the complement-mediated damage to the microvascular endothelium because of inherited defects in complement genes or autoantibodies against complement regulatory proteins. Incomplete penetrance of aHUS in carriers of mutations is common to all aHUS-associated complement genes and it is now established that the overall genetic predisposition to aHUS of an individual results from the combination of different inherited factors. Moreover, the patient's genotype influences the clinical evolution, the response to plasma therapies, and the recurrence after transplantation. Here, we describe the genetic component of aHUS, the lessons that we have learned from the functional characterization of the aHUS-associated mutations, and the benefits of a comprehensive genetic analysis of the patients.
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Síndrome Hemolítico-Urêmica Atípica/genética , Proteínas do Sistema Complemento/genética , Mutação , Autoanticorpos/imunologia , Complemento C3/genética , Fator B do Complemento/genética , Fator H do Complemento/genética , Diacilglicerol Quinase/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Heterozigoto , Humanos , Íntrons , Splicing de RNA , Trombomodulina/genética , Microangiopatias Trombóticas/genéticaRESUMO
BACKGROUND: Atypical hemolytic uremic syndrome (aHUS) is a form of thrombotic microangiopathy (TMA) caused by dysregulation of the complement system. Outcomes of kidney transplantation are poor owing to aHUS recurrence and loss of graft. Patients carrying CFH mutations or CFH/CFHR1 hybrid genes present a very high risk of recurrence despite preventive plasmapheresis. Evaluation of recent data suggests that prophylactic eculizumab pretransplant might be the preferred therapy if available. CASE-DIAGNOSIS/TREATMENT: We report 3-year follow-up data in a 9-year-old boy with aHUS and successful renal transplant treated with prophylactic eculizumab without recurrence. He presented with aHUS at age 3, irreversible renal failure and uncontrolled severe hypertension with concentric left ventricular hypertrophy, recurrent acute pulmonary edema, and congestive heart failure despite five hypotensive agents and bilateral nephrectomy. Complement analysis demonstrated the presence of a CFH/CFHR1 hybrid gene inherited from his mother and a SNP risk CFH haplotype inherited from his father. Kidney transplant was performed with prophylactic eculizumab and subsequent fortnightly administration. Three years post-transplant, graft function remains stable (serum creatinine 0.9 mg/dl), hypertension is controlled, no left ventricular hypertrophy, no opportunistic infections, and negative clinical chemistry parameters for hemolysis. CONCLUSION: Eculizumab is a safe and effective therapy for preventing TMA recurrence and provides long-term graft function in aHUS with the CFH/CFHR1 hybrid gene.
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Anticorpos Monoclonais Humanizados/uso terapêutico , Síndrome Hemolítico-Urêmica/terapia , Transplante de Rim , Proteínas Mutantes Quiméricas/genética , Síndrome Hemolítico-Urêmica Atípica , Criança , Síndrome Hemolítico-Urêmica/genética , Humanos , MasculinoRESUMO
Several abnormalities in complement genes reportedly contribute to atypical hemolytic uremic syndrome (aHUS), but incomplete penetrance suggests that additional factors are necessary for the disease to manifest. Here, we sought to describe genotype-phenotype correlations among patients with combined mutations, defined as mutations in more than one complement gene. We screened 795 patients with aHUS and identified single mutations in 41% and combined mutations in 3%. Only 8%-10% of patients with mutations in CFH, C3, or CFB had combined mutations, whereas approximately 25% of patients with mutations in MCP or CFI had combined mutations. The concomitant presence of CFH and MCP risk haplotypes significantly increased disease penetrance in combined mutated carriers, with 73% penetrance among carriers with two risk haplotypes compared with 36% penetrance among carriers with zero or one risk haplotype. Among patients with CFH or CFI mutations, the presence of mutations in other genes did not modify prognosis; in contrast, 50% of patients with combined MCP mutation developed end stage renal failure within 3 years from onset compared with 19% of patients with an isolated MCP mutation. Patients with combined mutations achieved remission with plasma treatment similar to patients with single mutations. Kidney transplant outcomes were worse, however, for patients with combined MCP mutation compared with an isolated MCP mutation. In summary, these data suggest that genotyping for the risk haplotypes in CFH and MCP may help predict the risk of developing aHUS in unaffected carriers of mutations. Furthermore, screening patients with aHUS for all known disease-associated genes may inform decisions about kidney transplantation.
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Proteínas do Sistema Complemento/genética , Síndrome Hemolítico-Urêmica/genética , Síndrome Hemolítico-Urêmica/imunologia , Mutação , Adulto , Síndrome Hemolítico-Urêmica Atípica , Criança , Pré-Escolar , Complemento C3/genética , Fator B do Complemento/genética , Fator H do Complemento/genética , Feminino , Fibrinogênio/genética , Estudos de Associação Genética , Haplótipos , Humanos , Lactente , Masculino , Proteína Cofatora de Membrana/genética , Pessoa de Meia-Idade , Linhagem , Penetrância , Fatores de Risco , Adulto JovemRESUMO
Mutations and polymorphisms in the gene-encoding factor H (CFH) are associated with atypical hemolytic uremic syndrome, dense deposit disease, and age-related macular degeneration. Many of these CFH genetic variations disrupt the regulatory role of factor H, supporting the concept that dysregulation of complement is a unifying pathogenic feature of these disorders. Evidence of a causal relationship with the disease is, however, not available for all CFH genetic variations found in patients, which is a potential cause of misinterpretations with important consequences for the patients and their relatives. CFH I890 and L1007 are two genetic variations repeatedly associated with atypical hemolytic uremic syndrome and also found in patients with dense deposit disease and age-related macular degeneration. Here we report an extensive genetic and functional analysis of these CFH variants. Our results indicate that I890 and L1007 segregate together as part of a distinct and relatively infrequent CFH haplotype in Caucasians. Extensive analysis of the S890/V1007 (control) and I890/L1007 (disease-associated) factor H protein variants failed to provide evidence that these amino acid changes have functional implications. Thus, the presence of the I890 and L1007 variants in healthy individuals and their high frequency in sub-Saharan African and African-American populations strongly suggest that I890 and L1007 are rare factor H polymorphisms unrelated to disease.
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Variação Genética , Síndrome Hemolítico-Urêmica/genética , Adulto , África Subsaariana , Negro ou Afro-Americano/genética , Substituição de Aminoácidos , Síndrome Hemolítico-Urêmica Atípica , População Negra/genética , Pré-Escolar , Fator H do Complemento/genética , Frequência do Gene , Predisposição Genética para Doença , Glomerulonefrite Membranoproliferativa/genética , Haplótipos , Síndrome Hemolítico-Urêmica/sangue , Humanos , Lactente , Degeneração Macular/genética , Masculino , Pessoa de Meia-Idade , Mutação , Polimorfismo Genético , EspanhaRESUMO
Dense deposit disease (DDD) is a severe renal disease characterized by accumulation of electron-dense material in the mesangium and glomerular basement membrane. Previously, DDD has been associated with deficiency of factor H (fH), a plasma regulator of the alternative pathway (AP) of complement activation, and studies in animal models have linked pathogenesis to the massive complement factor 3 (C3) activation caused by this deficiency. Here, we identified a unique DDD pedigree that associates disease with a mutation in the C3 gene. Mutant C(3923ΔDG), which lacks 2 amino acids, could not be cleaved to C3b by the AP C3-convertase and was therefore the predominant circulating C3 protein in the patients. However, upon activation to C3b by proteases, or to C3(H2O) by spontaneous thioester hydrolysis, C(3923ΔDG) generated an active AP C3-convertase that was regulated normally by decay accelerating factor (DAF) but was resistant to decay by fH. Moreover, activated C(3b923ΔDG) and C3(H2O)(923ΔDG) were resistant to proteolysis by factor I (fI) in the presence of fH, but were efficiently inactivated in the presence of membrane cofactor protein (MCP). These characteristics cause a fluid phase-restricted AP dysregulation in the patients that continuously activated and consumed C3 produced by the normal C3 allele. These findings expose structural requirements in C3 that are critical for recognition of the substrate C3 by the AP C3-convertase and for the regulatory activities of fH, DAF, and MCP, all of which have implications for therapeutic developments.
Assuntos
Ativação do Complemento , Complemento C3/genética , Glomerulonefrite Membranoproliferativa/genética , Mutação , Adulto , Complemento C3/análise , Convertases de Complemento C3-C5/fisiologia , Complemento C3b/metabolismo , Fator H do Complemento/metabolismo , Feminino , Glomerulonefrite Membranoproliferativa/etiologia , Glomerulonefrite Membranoproliferativa/imunologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Serotonin (5-HT) plays a key role in controlling food intake and feeding behaviour and drugs targeting the 5-HT transporter (SERT) at the synaptic cleft have been used to treat feeding related disorders. To test the hypothesis that SERT might be one of the etiologic factors in the rebound hyperphagia that frequently follows the abandoning of calorie restriction diets, brain SERT content and gene expression were assessed in a restricted feeding/repletion (RFR) protocol in female rats. Animals were food-restricted (2 h access to food per day) for 7 consecutive days and then allowed constant free access to food (FAF). This intermittent fasting protocol resulted in rebound hyperphagia. Higher levels of plasma corticosterone during fasting in food-deprived rats were used as an index of hypothalamic-pituitary-adrenal axis activation. Neither brain SERT density nor expression was modified following the RFR protocol. Nevertheless, with respect to other messengers involved in eating behaviour, in the presence of low plasma leptin levels, an increase in NPY expression and a parallel decrease in POMC expression were observed in the hypothalamic arcuate nucleus of rats killed just before rebound hyperphagia. Food-restricted animals provide a tool for the further study of neurochemical alterations and for the development of new drugs to treat alterations that may occur in humans when dieting is abandoned.
Assuntos
Encéfalo/fisiologia , Jejum/fisiologia , Comportamento Alimentar/fisiologia , Neuropeptídeo Y/metabolismo , Pró-Opiomelanocortina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Animais , Núcleo Arqueado do Hipotálamo/fisiologia , Corticosterona/sangue , Dieta Redutora , Jejum/sangue , Feminino , Expressão Gênica , Hiperfagia/sangue , Hiperfagia/etiologia , Hiperfagia/metabolismo , Leptina/sangue , Neuropeptídeo Y/genética , Pró-Opiomelanocortina/genética , Ratos , Ratos Sprague-Dawley , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Fatores de TempoRESUMO
As there are few comparative studies on mammalian red cell metabolism, it was decided to study the glycolytic enzyme activities aswell as related ones, and the metabolites adenosine-5´-triphosphate(ATP) and 2,3-bisphosphoglycerate (2,3-BPG). Mammalia representatives from Primates, Rodentia, Carnivora, Lagomorpha,Artyodactyla, Didelphimorphia and Xenarthra orders, obtained from Fundação Parque Zoológico de São Paulo and Centro de Bioterismoda Faculdade de Medicina da USP, were studied. The blood was collectedin EDTA and ACD, the red cells were washed in saline at 4o C, lysed1:20 in hemolysing solution by freeze-and-thaw, and the followingenzymes were assayed according to standard procedures: hexokinase,glucose-6-phosphate isomerase, phosphofructokinase, aldolase, triosephosphate isomerase, glyceraldehyde-3-phosphate dehydrogenase,phosphoglycerate kinase, monophosphoglycerate mutase, enolase,pyruvate kinase, lactate dehydrogenase, as well as 2,3-bisphosphoglycerate mutase, glucose-6-phosphate dehydrogenase,6-phosphogluconate dehydrogenase activities at 37oC , and adenosine-5´-triphosphate and 2,3-bisphophoglycerate concentrations. Are markable variation among the studied species was observed.However, it was detected a significant positive correlation between the adenosine-5´-triphosphate concentrations and triose phosphate isomerase and 2,3-bisphosphoglycerate mutase activities, as well assignificant positive correlation between 2,3-bisphosphoglycerate concentration and 2,3-bisphosphoglycerate mutase activity in all studied species as a whole. Most of studied species exhibited a steady ATP concentration range between 4 and 6 μ moles.g Hb 1 except the Artiodactyla (Cervus elaphus) and Carnivora (Panthera leo, Leoparduspardalis, Canis Lupus and Chrysocyon brachyurus,) which presented values between 2 and 3 μ moles g Hb 1. However, the 2,3-BPG concentration showed remarkable variation among the studied ...
Como há poucos estudos comparativos sobre o metabolismo eritrócitário dos mamíferos propôs-se estudar as atividades das enzimas glicolíticas, anexas e os metabólitos adenosina-5-trifosfato e2,3-difosfoglicerato. Foram estudados mamíferos das ordens Primata,Rodentia, Carnivora, Lagomorpha, Artiodactyla, Didelphimorphia eXenarthra oriundos da Fundação Parque Zoológico de São Paulo e Centro de Bioterismo da Faculdade de Medicina da USP. O sangue foicolhido em EDTA e ACD, os eritrócitos foram lavados em soluçãofisiológica a 4o C e hemolisados em solução hemolisante 1:20 porcongelamento e descongelamento e as atividades das seguintes enzimasforam determinadas de acordo com procedimentos padronizados:hexoquinase, glicose-6-fosfato isomerase , fosfofrutoquinase, aldolase,triose fosfato isomerase, gliceraldeído-3-fosfato desidrogenase,fosfoglicerato quinase, 2,3-difosfoglicerato mutase,monofosfogliceromutase, enolase, piruvato quinase, lactatodesidrogenase, bem como a glicose-6-fosfato desidrogenase, 6-fosfogluconato desidrogenase a 37ºC e os metabólitos intermediários2,3-difosfoglicerato e adenosina-5-trifosfato. As enzimas e os compostos intermediários estudados apresentaram grande variabilidade entre as espécies de mamíferos estudadas. Foi observada correlação positiva entre a atividade da triose fosfato isomerase e a 2,3-difosfoglicerato mutase e os teores de adenosina-5-trifosfato das espécies, bem como correlação positiva entre a 2,3-difosfogliceratomutase em relação ao 2,3-difosfoglicerato. Os teores de adenosina-5-trifosfato mantiveram-se dentro de uma faixa estável, ao redor de 4 a6 μ moles / gHb, com as exceções das espécies das ordens Carnivora(Panthera leo, Leopardus pardalis, Canis lupus and Chrysocyonbrachyurus) e Artiodactyla (Cervus elaphus), que exibiram 2 a 3 μmoles / g Hb. Já os valores da concentração de 2,3-difosfoglicerato apresentaram, por sua vez, variação considerável entre as..
Assuntos
Bisfosfoglicerato Mutase/efeitos adversos , Enzimas/efeitos adversos , Mamíferos , Trifosfato de Adenosina/efeitos adversosRESUMO
The floristic variations of shrub and tree components were studied in two sites of Semideciduous Forest, initial forest and mature forest, located in the Mata do Paraíso Forest Reserve, in Viçosa, State of Minas Gerais, Southeastern Brazil, in order to analyze the floristic similarity and the correlations between environmental variables and the distribution of tree species in these forests. Individual trees with a diameter at breast height (DBH) ≥ 4.8 cm were sampled in twenty 10 x 30 m plots (10 plots in each site). The plots were distributed systematically at 10 m intervals. The environmental variables analyzed were: the canopy openness and soil chemical and texture characteristics. The two forest sites showed clear differences in the levels of canopy openness and soil fertility, factors that reflect the floristic and successional differences of the shrub and tree component, revealed by the low similarity between these forests by cluster analysis. The canonical correspondence analysis (CCA) of environmental variables and species abundance indicated that the species in these forests studied are distributed under strong influence of canopy openness, moisture and soil fertility. Rev. Biol. Trop. 56 (3): 15571569. Epub 2008 September 30.
Estudiamos las variaciones florísticas de arbustos y árboles en dos sitios de un bosque semicaducifolio, bosque primario y bosque maduro, en la Reserva Forestal Mata do Paraíso, en Viçosa, Estado de Minas Gerais, Sudeste de Brasil, para analizar la similitud florística y las correlaciones entre las variables ambientales y la distribución de tres especies en estos bosques. Árboles individuales con diámetro a la altura del pecho (DAP) ≥ 4.8 cm. fueron muestreados en veinte parcelas de 10 x 30 m (10 parcelas en cada sitio). Las parcelas se distribuyeron sistemáticamente a intervalos de 10 m. Las variables ambientales fueron analizadas así: la abertura del dosel y características químicas y de textura del suelo. Los dos sitios de bosque mostraron diferencias evidentes en la abertura del dosel y fertilidad del suelo, factores que reflejan las diferencias florísticas y sucesionales de arbustos y árboles, revelado por la baja similitud entre estos bosques por medio de análisis de conglomerados. El análisis de correspondencia canónica (CCA) de variables ambientales y abundancia de especies indican que las especies en los bosques estudiados están distribuidas bajo una fuerte influencia de la abertura del dosel, humedad y fertilidad del suelo.
Assuntos
Ecossistema , Árvores/classificação , Brasil , Conservação dos Recursos Naturais , Umidade , SoloRESUMO
O presente estudo teve como objetivo apresentar um caso clínico de traumatismo dentário com fratura radicular horizontal apresentando mau prognóstico devido à qualidade do atendimento inicial. O tratamento proposto constitui-se a terapia endodôntica ortógrada com medidas para o controle da infecção presente no sistema de canais radiculares e realização da obturação endodôntica por compartimentos, sendo a porção apical selada com guta-percha e o segmento coronário com MTA. Após cinco anos de acompanhamento, há sinais significativos de sucesso na terapia proposta.
Assuntos
Humanos , Masculino , Adulto , Fraturas dos Dentes/classificação , Tratamento do Canal Radicular , Traumatismos DentáriosRESUMO
The floristic variations of shrub and tree components were studied in two sites of Semideciduous Forest, initial forest and mature forest, located in the Mata do Paraíso Forest Reserve, in Viçosa, State of Minas Gerais, Southeastern Brazil, in order to analyze the floristic similarity and the correlations between environmental variables and the distribution of tree species in these forests. Individual trees with a diameter at breast height (DBH) > or = 4.8 cm were sampled in twenty 10 x 30 m plots (10 plots in each site). The plots were distributed systematically at 10 m intervals. The environmental variables analyzed were: the canopy openness and soil chemical and texture characteristics. The two forest sites showed clear differences in the levels of canopy openness and soil fertility, factors that reflect the floristic and successional differences of the shrub and tree component, revealed by the low similarity between these forests by cluster analysis. The canonical correspondence analysis (CCA) of environmental variables and species abundance indicated that the species in these forests studied are distributed under strong influence of canopy openness, moisture and soil fertility.
Assuntos
Ecossistema , Árvores/classificação , Brasil , Conservação dos Recursos Naturais , Umidade , SoloRESUMO
A hiperglicemia näo-cetótica é uma doença genética, de herança autossômica recessiva, que causa distúrbios graves em recém-nascidos, podem levar à morte. Níveis aumentados de glicina no cérebro produzem lesäo neurológica irreversível. O diagnóstico clínico é confirmado por cromatografia líquida (HPLC), comparando-se os níveis de glicina em plasma e líquido cefalorraquidiano - uma relaçäo LCR/plasma maior do que 0,09 fecha o diagnóstico. O presente estudo relata dois casos de hiperglicemia neonatal com quadro clínico e evoluçäo neurológica semelhantes. Nos dois casos, os sintomas começaram nas primeiras 48 horas de vida, e näo havia antecedentes familiares, pré-natais ou perinatais. Os dois recém-nascidos apresentaram boas condiçöes ao nascimento. Além disso, em ambos os casos, o daignóstico laboratorial (HPLC) foi bastante tardio: as amostras de sangue total e liquor foram colhidas 55§ e no 17§ dia, respectivamente. As concentraçöes de glicina em LCR e plasma, e a relaçäo LCR/plasma, foram (em mg/dl), para as crianças número 1 e número 2, repectivamente: 2,8 e 3,3 (R=0,85); 2,4 e 8 (r=0,3). Muito embora os recém-nascidos tenham permanecido em unidade de terapia intensiva e suporte ventilatório e tenham sido medicados com benzoato de sódio e diazepam, o diagnóstico tardio da hiperglicinemia acarretou lesöes neurológicas graves e irreversíveis nas duas crianças. No entanto, a importância do diagnóstico laboratorial para o aconselhamento genético dos dois casais é inquestionável