935 resultados para MOLYBDENUM COFACTOR DEFICIENCY


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Muscle coenzyme Q(10) (CoQ(10) or ubiquinone) deficiency has been identified in more than 20 patients with presumed autosomal-recessive ataxia. However, mutations in genes required for CoQ(10) biosynthetic pathway have been identified only in patients with infantile-onset multisystemic diseases or isolated nephropathy. Our SNP-based genome-wide scan in a large consanguineous family revealed a locus for autosomal-recessive ataxia at chromosome 1q41. The causative mutation is a homozygous splice-site mutation in the aarF-domain-containing kinase 3 gene (ADCK3). Five additional mutations in ADCK3 were found in three patients with sporadic ataxia, including one known to have CoQ(10) deficiency in muscle. All of the patients have childhood-onset cerebellar ataxia with slow progression, and three of six have mildly elevated lactate levels. ADCK3 is a mitochondrial protein homologous to the yeast COQ8 and the bacterial UbiB proteins, which are required for CoQ biosynthesis. Three out of four patients tested showed a low endogenous pool of CoQ(10) in their fibroblasts or lymphoblasts, and two out of three patients showed impaired ubiquinone synthesis, strongly suggesting that ADCK3 is also involved in CoQ(10) biosynthesis. The deleterious nature of the three identified missense changes was confirmed by the introduction of them at the corresponding positions of the yeast COQ8 gene. Finally, a phylogenetic analysis shows that ADCK3 belongs to the family of atypical kinases, which includes phosphomositide and choline kinases, suggesting that ADCK3 plays an indirect regulatory role in ubiquinone biosynthesis possibly as part of a feedback loop that regulates ATP production.

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Introduction: Periapical lesions are chronic inflammatory disorders of periradicular tissues caused by etiologic agents of endodontic origin. The inflammatory chemokines are thought to be involved in the latter observed osteolysis. With a murine model of experimental periapical lesion, the objective of this study was to evaluate the role of the chemokine receptor CCR2 in the lesion progression, osteoclast differentiation and activation, and expression of inflammatory osteolysis-related mediators. Methods: For lesion induction, right mandibular first molars were opened surgically with a (1)/(4) carbine bur, and 4 bacterial strains were inoculated in the exposed dental pulp; left mandibular first molars were used as controls. Animals were killed at 3, 7, 14, and 21 days after surgeries to evaluate the kinetics of lesion development. Results: CCR2 KO mice showed wider lesions than WT mice. CCR2 KO mice also expressed higher levels of the osteoclastogenic and osteolytic factors, receptor activator of nuclear factor kappa B ligand (RANKL) and cathepsin K, of the proinflammatory cytokine tumor necrosis factor alpha, and of the neutrophil migration related chemokine, KC. Conclusions: These results suggest that CCR2 is important in host protection to periapical osteolysis. (J Endod 2010;36:244-250)

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Trypanosoma cruzi, the etiologic agent for Chagas` disease, has requirements for several cofactors, one of which is heme. Because this organism is unable to synthesize heme, which serves as a prosthetic group for several heme proteins (including the respiratory chain complexes), it therefore must be acquired from the environment. Considering this deficiency, it is an open question as to how heme A, the essential cofactor for eukaryotic CcO enzymes, is acquired by this parasite. In the present work, we provide evidence for the presence and functionality of genes coding for heme O and heme A synthases, which catalyze the synthesis of heme O and its conversion into heme A, respectively. The functions of these T. cruzi proteins were evaluated using yeast complementation assays, and the mRNA levels of their respective genes were analyzed at the different T. cruzi life stages. It was observed that the amount of mRNA coding for these proteins changes during the parasite life cycle, suggesting that this variation could reflect different respiratory requirements in the different parasite life stages.

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We identified a 4-year-old Brazilian boy from a family of Japanese descent and history of consanguinity, who suffered from severe recurrent pneumonia. He carries factor H (FH) deficiency associated with reduced levels of component C9 and low serum levels of C3 and factor B. His mother also presented low levels of these proteins and factor I, while his father and sister had only lower levels of FH. Western blot assays confirmed the complete absence of FH and FHL-1 polypeptides in this patient. Sequencing of the proband`s FH cDNA revealed a homozygous G453A substitution, encoding an Arg(127)His change. His mother, father and sister are heterozygous for this substitution. Despite the absence of FH in the plasma, this protein was detected in the patient`s fibroblasts, suggesting that Arg(127) may be important for FH secretion. Low concentrations of C9 were detected in the proband serum but no mutations in the patient`s C9 gene or promoter have been identified, suggesting that this is a consequence of uncontrolled complement activation and high C9 consumption.

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The metastable phase diagram of the BCC-based ordering equilibria in the Fe-Al-Mo system has been calculated via a truncated cluster expansion, through the combination of Full-Potential-Linear augmented Plane Wave (FP-LAPW) electronic structure calculations and of Cluster Variation Method (CVM) thermodynamic calculations in the irregular tetrahedron approximation. Four isothermal sections at 1750 K, 2000 K, 2250 K and 2500 K are calculated and correlated with recently published experimental data on the system. The results confirm that the critical temperature for the order-disorder equilibrium between Fe(3)Al-D0(3) and FeAl-B2 is increased by Mo additions, while the critical temperature for the FeAl-B2/A2 equilibrium is kept approximately invariant with increasing Mo contents. The stabilization of the Al-rich A2 phase in equilibrium with overstoichiometric B2-(Fe,Mo)Al is also consistent with the attribution of the A2 structure to the tau(2) phase, stable at high temperatures in overstoichiometric B2-FeAl. (C) 2009 Elsevier Ltd. All rights reserved.

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Aim: The aim of the study was to evaluate the association between Helicobacter pylori infection and iron deficiency (ID) in adolescents attending a public school. Patients and Methods: From March to June 2001, a cross-sectional study was conducted among adolescents (10-16 years) enrolled in a single public school in Sao Paulo, Brazil. Of 400 eligible students, 195 agreed to participate, but 1 was excluded due to sickle cell disease. A blood sample was collected from each subject to measure hemoglobin and ferritin. H pylori status was investigated with the 13 C-urea breath test. All of the subjects with either anemia or ID were given iron therapy. Results: H pylori prevalence was 40.7% (79/194), being higher in male subjects (45/90 vs 34/104, P = 0.014). There was no relation between infection and nutritional status. Abnormally low serum ferritin was observed in 12 subjects, half of whom were positive for H pylori (odds ratio [OR] 1.49, 95% confidence interval [CI] 0.38-5.81). The median serum ferritin was 33.6 ng/mL (interquartile range 23.9-50.9) in infected subjects and 35.1 ng/mL (interquartile range 23.7-53.9) in uninfected subjects. Anemia was detected in 2% (4/194) of the students, half of whom were infected (OR 1.47, 95% CI 0.1-20.6). The mean hemoglobin value in infected subjects was 13.83 g/dL +/- 1.02 versus 14 g/dL +/- 1.06 in uninfected subjects. Conclusions: The study was not able to find a relation between H pylori infection and ID or anemia.

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The deficiency of complement C5 is rare and frequently associated with severe and recurrent infections, especially caused by Neisseria spp. We observed the absence of component C5 in the serum of 3 siblings from a Brazilian family with history of consanguinity. The patients had suffered from recurrent episodes of meningitis and other less severe infections. Sera from these patients were unable to mediate hemolytic activity either by the classical or alternative pathways and presented extremely low levels of C5 protein (13, 0.9 and 1.0 mu g/ml-normal range: 45-190 mu g/ml). Hemolytic activity could be restored by the addition of purified C5 to deficient serum. Sequencing of sibling C5 cDNA revealed a homozygous 153 bp deletion that corresponds precisely to exon 30. The parents carried the same deletion but only in one allele. Sequencing of the corresponding region in the genomic DNA revealed a C to C substitution within intron 30 and, most significantly, the substitution of GAG(4028) for GAA(4028) at the 3` end of exon 30 which is most likely responsible for skipping of exon 30. The resulting in-frame deletion in the C5 mRNA codes for a mutant C5 protein lacking residues 1289-1339. These residues map to the CUB and C5d domains of the C5 alpha chain. This deletion is expected to produce a non-functional and unstable C5 protein which is more susceptible to degradation. (C) 2009 Published by Elsevier Ltd.

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A deficiência de B é muito comum nos cafezais brasileiros, mas as respostas do cafeeiro ao B têm sido erráticas, dependendo do ano, do modo e época de aplicação e, ainda, da fonte de B empregada. Um melhor entendimento dos efeitos do B na fisiologia e anatomia do cafeeiro é importante para o desenvolvimento de um programa racional de adubação boratada, uma vez que a anatomia da planta pode influenciar a translocação do nutriente. Neste experimento, plantas de dois cultivares foram cultivadas em soluções nutritivas com 0,0 (deficiente), 5,0 (adequado) e 25,0 µM (alto) de B. Quando os primeiros sintomas de deficiência apareceram, as folhas foram cortadas e tiveram suas paredes celulares isoladas e analisadas quanto aos teores de B e Ca. Cortes foram feitos em folhas novas e no ápice de ponteiros e fotografados em microscópio eletrônico de varredura. A resposta dos dois cultivares ao B foi semelhante, não tendo sido observados sintomas de toxidez. O teor de B nas paredes celulares foi aumentado com o incremento da concentração desse elemento na solução, enquanto o teor de Ca não foi afetado. A relação Ca/B decresceu com o aumento da concentração de B na solução. Com deficiência de B, os tecidos vasculares foram desorganizados e as paredes do xilema ficaram mais finas. Folhas de café com deficiência deste nutriente apresentaram menos estômatos, os quais se encontravam.

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The objective of this work was to evaluate the effect of foliar application of molybdenum on agronomic characteristics and yield of wheat in a no-till system. The experiment was carried out in a clayey Rhodic Hapludox, in Maripa, State of Parana, Brazil. The experimental design was randomized blocks with five replications. Treatments consisted of four doses of molybdenum (0, 13.8, 27.6 and 55.2 g ha(-1) Mo), divided into two foliar applications, the first at tillering (18 days after plant emergence) and the second at the boot stage (65 days after emergence). The foliar application of Mo up to a dose of 35 g ha-1 increased the number of spikes per square meter and yield of wheat; however, it had no effect on the agronomic characteristics of the crop in a no-till system.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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OBJETIVO: O presente estudo teve como objetivo avaliar os genes PROP1 e HESX1 em um grupo de pacientes com displasia septo-óptica (DSO) e deficiência hormonal hipofisária (combinada - DHHC; ou deficiência isolada de GH - DGH). Onze pacientes com apresentação clínica e bioquímica consistente com DHHC, DGH ou DSO foram avaliados. SUBJECTS and METHODS: em todos os pacientes, o gene HESX1 foi analisado pelo sequenciamento direto e, nos casos de DHHC, o gene PROP1 foi também sequenciado. RESULTADOS: Um polimorfismo no gene HESX1 (1772 A > G; N125S) foi identificado em um paciente com DSO. Foram encontrados três pacientes portadores da variação alélica 27 T > C; A9A e 59 A > G; N20S no éxon 1 do gene PROP1. Mutações no gene PROP1 e HESX1 não foram identificadas nesses pacientes com DGH, DHHC e DSO esporádicos. CONCLUSÃO: Alterações genéticas em um ou diversos outros genes ou mecanismos não genéticos devem estar implicados nesse processo patogênico.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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PURPOSE. Amniotic membrane transplantation (AMT) has been used as a graft or as a dressing in ocular surface reconstruction, facilitating epithelization, maintaining normal epithelial phenotype, and reducing inflammation, vascularization, and scarring. The corneal transparency is due, at least in part, to the arrangement in orthogonal lamellae of collagen fibrils, surrounded by proteoglycans (PGs). These PGs regulate fibrilogenesis, the matrix assembly, and ultimately the corneal transparency. The purpose of the present study was to investigate the effects of AMT upon the corneal PGs after severe limbal injury.METHODS. Experiments were performed on the right corneas of 22 New Zealand female albino rabbits, and their left corneas were used as matched controls. These animals were divided into 3 groups: G1 (n = 10): total peritomy and keratolimbectomy, followed by application of 0.5 M NaOH; G2 (n = 10): submitted to the same trauma as G1, and treated by AMT; G3: no trauma, only AMT (n = 2). The right corneas of G2 and G3 were covered by DMSO 4 cryopreserved human amniotic membrane, fixed by interrupted 9-0 mononylon sutures, with its stromal face toward the ocular surface. After 7 or 30 days, the corneas were removed and PGs were extracted.RESULTS. Normal corneas contained approximately 9 mg of PGs per gram of dry tissue. AMT on intact cornea (G3) did not cause any changes in the concentration of PGs. In contrast, injured corneas contained much less PGs, both on the seventh and on the 30th day posttrauma. The PG concentration was even lower in injured corneas treated by AMT. This decrease was due almost exclusively to dermatan sulfate PGs, and the structure of dermatan sulfate was also modified, indicating changes in the biosynthesis patterns.CONCLUSIONS. Although beneficial effects have been observed on clinical observation and concentration of soluble proteins after AMT, the normal PG composition of cornea was not attained, even 30 days postinjury, indicating that the normal ocular surface reconstruction, if possible, is a long-term process. (Eur J Ophthalmol 2010; 20: 290-9)

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Objective. This study evaluated the influence of estrogen deficiency and its treatment on bone density around integrated implants.Study design. Implants were placed in female rat tibiae. The animals were assigned to 5 groups: control, sham, ovariectomy, estrogen, and alendronate. The control group was humanely killed to confirm integration of the implant. The others were submitted to ovariectomy or sham surgery. Bone density was measured by digital radiographs at 6 points on sides of the implant.Results. The analysis of radiographic bone density revealed estrogen privation had a negative impact only in the cancellous bone. The estrogen group differed significantly ( P <.05) from the ovariectomy and alendronate groups. The alendronate group presented the highest density for all evaluated regions.Conclusion. Ovariectomy caused a decrease in the radiographic bone density in the cancellous region. Estrogen replacement therapy and alendronate were effective treatments in preventing bone mass loss around integrated implants.