977 resultados para Bone development


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The longest open reading frame of PKHD1 (polycystic kidney and hepatic disease 1), the autosomal recessive polycystic kidney disease (ARPKD) gene, encodes a single-pass, integral membrane protein named polyductin or fibrocystin. A fusion protein comprising its intracellular C-terminus, FP2, was previously used to raise a polyclonal antiserum shown to detect polyductin in several human tissues, including liver. In the current study, we aimed to investigate by immunohistochemistry the detailed polyductin localization pattern in normal (ductal plate [DP], remodelling ductal plate [RDP], remodelled bile ducts) and abnormal development of the primitive intrahepatic biliary system, known as ductal plate malformation (DPM). This work also included the characterization of polyductin expression profile in various histological forms of neonatal and infantile cholestasis, and in cholangiocellular carcinoma (CCC) and hepatocellular carcinoma (HCC). We detected polyductin expression in the intrahepatic biliary system during the DP and the RDP stages as well as in DPM. No specific staining was found at the stage of remodelled bile ducts. Polyductin was also detected in liver biopsies with neonatal cholestasis, including mainly biliary atresia and neonatal hepatitis with ductular reaction as well as congenital hepatic fibrosis. In addition, polyductin was present in CCC, whereas it was absent in HCC. Polyductin was also co-localized in some DP cells together with oval stem cell markers. These results represent the first systematic study of polyductin expression in human pathologies associated with abnormal development of intrahepatic biliary tree, and support the following conclusions: (i) polyductin expression mirrors developmental properties of the primitive intrahepatic biliary system; (ii) polyductin is re-expressed in pathological conditions associated with DPM and (iii) polyductin might be a potential marker to distinguish CCC from HCC.

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Purpose: Animal models of diseases are extremely important in the study of the physiopathogenesis of human diseases and for testing novel therapeutic interventions. The present study aimed to develop an animal model that simulates human allergic conjunctivitis and to study how allergic response may be influenced by the allergen dose used for immunization and by genetic factors. Methods: Sixty C57Bl/6 mice and 60 BALB/c mice were immunized with placebo, or 5 mu g or 500 mu g of allergen derived from Dermatophagoides pteronyssinus. After ocular challenge, the mice were examined in order to clinically verify the occurrence or not of conjunctivitis. Material obtained from animals was used for total and specific IgE and IgG1 dosage, for assays of Der p-specific lymphocyte proliferation and supernatant cytokine dosage, and for histopathological evaluation of conjunctiva. Results: We developed a murine model of allergic conjunctivitis induced by D. pteronyssinus. The model is similar to human disease both clinically and according to laboratory findings. In mouse, conjunctivitis was associated with a Th2 cytokine profile. However, IL-10 appeared to be involved with disease blockade. Mice of different strains have distinct immune responses, depending on the sensitization dose. Conclusions: The murine model developed is suitable for the study of immunopathogenesis and as a template for future therapies. Using BALB/c and C57BL/6 mice, we demonstrated that genetic factors play a role in determining susceptibility and resistance, as well as in establishing the allergen concentration needed to induce or to block disease development.

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Lipid emulsions that mimic natural lipoproteins help to understand the metabolism and the constitutional organization of circulating lipids. Chylomicrons synthesised by enterocyte cells usually contain oxysterols such as 7-ketocholesterol (7-KC). Here we describe the development of a 7-KC-containing emulsion as a model for oxisterol-rich chylomicron. Different amounts of 7-KC were used. Emulsion characteristics as effective diameter, lipid saturation with radiolabeled lipids was evaluated. In conclusion, the production of a synthetic 7-KC-rich emulsion resembling hylomicrons was feasible, being a model for in vivo metabolism studies.

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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.

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Objective: To analyse bone mineral density (BMD) in juvenile dermatomyositis (JDM) and its possible association with body composition, disease activity, duration of disease, glucocorticoid (GC) use, and biochemical bone parameters, including osteoprotegerin (OPG) and receptor activator of nuclear factor B (RANKL). Methods: Twenty girls with JDM and 20 controls matched for gender and age were selected. Body composition and BMD were analysed by dual-energy X-ray absorptiometry (DXA) and bone mineral apparent density (BMAD) was calculated. Duration of disease, cumulative GC, and GC pulse therapy use were determined from medical records. Disease activity and muscle strength were measured by the Disease Activity Score (DAS), the Childhood Myositis Assessment Scale (CMAS), and the Manual Muscle Test (MMT). Inflammatory and bone metabolism parameters were also analysed. OPG and RANKL were measured in patients and controls using an enzyme-linked immunosorbent assay (ELISA). Results: A lower BMAD in the femoral neck (p< 0.001), total femur (p< 0.001), and whole body (p=0.005) was observed in JDM patients compared to controls. Body composition analysis showed a lower lean mass in JDM compared to controls (p=0.015), but no difference was observed with regard to fat mass. A trend of lower serum calcium was observed in JDM (p=0.05), whereas all other parameters analysed, including OPG and RANKL, were similar. Multiple linear regression analysis revealed that, in JDM, lean mass (p< 0.01) and GC pulse therapy use (p< 0.05) were independent factors for BMAD in the hip region. Conclusions: This study has identified low lean mass and GC pulse therapy use as the major factors for low hip BMAD in JDM patients.

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Objective: To evaluate the importance of receptor activator of nuclear factor kappa B (RANK)/receptor activator of nuclear factor kappa B ligand (RANKL)/osteoprotegerin (OPG) modulation in active polyarticular juvenile idiopathic arthritis (pJIA) patients with and without bone erosions. Methods: Thirty female patients (mean age 11.07 +/- 3.77 years, range 4-17 years) with active pJIA and 30 healthy gender-and age-matched controls were consecutively selected for this study. All involved articulations were assessed by X-ray and examined for the presence of bone erosions. The serum levels of RANKL and OPG were measured using an enzyme-linked immunosorbent assay (ELISA). Results: Patients with active pJIA had higher levels of serum RANKL than controls [2.90 (0.1-37.4) vs. 0.25 (0.1-5.7) pg/mL, p=0.007] and a lower OPG/RANKL ratio [21.25 (1.8-897.6) vs. 347.5 (9-947.8), p=0.005]. However, levels of OPG were comparable in both groups [55.24 (28.34-89.76) vs. 64.42 (30.68-111.28) pg/mL, p=0.255]. Higher levels of serum RANKL and a lower OPG/RANKL ratio were also observed in active pJIA patients with bone erosions compared to controls [3.49 (0.1-37.4) vs. 0.25 (0.1-5.7) pg/mL, p=0.0115 and 14.3 (1.8-897.6) vs. 347.5 (9-947.8), p=0.016]. However, RANKL levels and OPG/RANKL ratio were similar in pJIA patients without bone erosion and controls [1.75 (0.1-10.9) vs. 0.25 (0.1-5.7) pg/mL, p=0.055 and 29.2 (3.3-756.8) vs. 347.5 (9-947.8), p=0.281]. Conclusion: These data suggest that active pJIA with bone erosions is associated with high serum levels of RANKL and a low OPG/RANKL ratio, indicating that these alterations may reflect bone damage in this disease.

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Immunohistochemistry of undecalcified bone sections embedded in methyl methacrylate (MMA) is not commonly employed because of potential destruction of tissue antigenicity by highly exothermic polymerization. The aim of the present study was to describe a new technique in which a quick decalcification of bone sections embedded in MMA improves the results for immunohistochemistry. The quality of interleukin 1 alpha (IL-1 alpha) immunostaining according to the present method was better than the conventional one. Immunostaining for osteoprotegerin (OPG) and the receptor activator of NF-kappa B ligand (RANKL) in bone sections of chronic kidney disease patients with mineral bone disorders (CKD-MBD) was stronger than in controls (postmortem healthy subjects). The present study suggested that this method is easy, fast, and effective to perform both histomorphometry and immunohistochemistry in the same bone fragment, yielding new insights into pathophysiological aspects and therapeutic approaches in bone disease.

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The aim of this study was to evaluate risk factors for low bone mineral density (BMD) and vertebral fractures, in juvenile systemic lupus (JSLE). Thirty-one consecutive patients with JSLE were compared with 31 gender- and age-matched healthy controls. BNID and body composition from all participants were measured using dual-energy X-ray absorptiometry. Vertebral fractures were defined as a reduction of >= 20% of the vertebral height for all patients. Lumbar spine and total femur BMD was significantly decreased in patients compared with controls (P = 0.021 and P = 0.023, respectively). A high frequency of vertebral fractures (22.58%) was found in patients with JSLE. Analysis of body composition revealed lower lean mass (P = 0.033) and higher fat mass percentage (P = 0.003) in patients than in controls. Interestingly, multiple linear regression using BMD as a dependent variable showed a significant association with lean mass in lumbar spine (R(2) = 0.262; P = 0.004) and total femur (R(2) = 0.419, P = 0.0001), whereas no association was observed with menarche age, SLE Disease Activity Index, Systemic Lupus International Collaborating Clinics/American College of Rheumatology, and glucocorticoid. This study indicates that low BMD and vertebral fractures are common in JSLE, and the former is associated with low lean mass, suggesting that muscle rehabilitation may be an additional target for bone therapeutic approach.

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Juvenile onset systemic sclerosis (JoSSc) is a rare disease, and there are no studies focusing in bone mineral density and biochemical bone parameters. Ten consecutive patients with JoSSc and 10 controls gender, age, menarche age, and physical activity matched were selected. Clinical data were obtained at the medical visit and chart review. Laboratorial analysis included autoantibodies, 25-hydroxyvitamin D (25OHD), intact parathyroid hormone, calcium, phosphorus, alkaline phosphatase and albumin sera levels. Bone mineral density was analyzed by dual-energy X-ray absorptiometry, and bone mineral apparent density (BMAD) was calculated. A lower BMAD in femoral neck (0.294 +/- A 0.060 vs. 0.395 +/- A 0.048 g/cm(3), P = 0.001) and total femur (0.134 +/- A 0.021 vs. 0.171 +/- A 0.022 g/cm(3), P = 0.002) was observed in JoSSc compared to controls. Likewise, a trend to lower BMAD in lumbar spine (0.117 +/- A 0.013 vs. 0.119 +/- A 0.012 g/cm(3), P = 0.06) was also found in these patients. Serum levels of 25OHD were significantly lower in JoSSc compared to controls (18.1 +/- A 6.4 vs. 25.1 +/- A 6.6 ng/mL, P = 0.04), and all patients had vitamin D insufficiency (< 20 ng/mL) compared to 40% of controls (P = 0.01). All other biochemical parameters were within normal range and alike in both groups. BMAD in femoral neck and total femur was correlated with 25OHD levels in JoSSc (r = 0.82, P = 0.004; r = 0.707, P = 0.02; respectively). We have identified a remarkable high prevalence of 25OHD insufficiency in JoSSc. Its correlation with hip BMAD suggests a causal effect and reinforces the need to incorporate this hormone evaluation in this disease management.

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Purpose This study evaluated the effect of severe magnesium (Mg) dietary deficiency on systemic bone density and biomechanical resistance of bone tissue to the removal torque of osseointegrated implants Materials and Methods The sample consisted of 45 rats, each received a titanium implant in their tibial metaphysis After 60 days, the animals were divided into three groups (n = 15) according to their dietary Mg the control group received the recommended content of Mg, group Mg1 received a 75% reduction in dietary Mg content, and group Mg2 was fed a diet with a 90% reduction in Mg con tent Animals were sacrificed 150 days after implant placement Serum concentrations of Mg were measured and the effect of Mg deficiency on systemic bone density was evaluated by densitometry of the lumbar vertebrae and femur Biomechanical characteristics were measured by resistance of the bone tissue to removal of the implants Results Lower Mg serum concentrations were found for the Mg1 and Mg2 groups, however, densitometric analysis and torque evaluations showed a statistically significant difference only in the Mg2 group (P < 05) There was a statistically significant difference in removal torque between the Mg2 group and the control group Conclusions This study showed that a severe deficiency of Mg decreased the systemic bone density and removal torque of osseointegrated implants INT J ORAL MAXILLOFAC IMPLANTS 2010 25 1125-1130

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We have studied gene expression during ascidian embryonic development using the technique of differential display and isolated partial cDNA sequences of 12 genes. Developmental regulation of these genes has been confirmed by northern hybridization analysis. Further cDNA cloning and sequence analysis of an mRNA that is present during gastrulation, neurulation and tailbud formation reveals that it encodes a novel serine protease containing a single kringle motif and catalytic domain. The spatial expression of this gene, designated Hmserp1, is restricted to precursor cells of the epidermis. The structure and expression of Hmsery1 is discussed in relation to possible functions during development.

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The aim of this study was to analyze vitamin D levels and their association with bone mineral density and body composition in primary antiphospholipid syndrome. For this cross-sectional study 23 premenopausal women with primary antiphospholipid syndrome (Sapporo criteria) and 23 age- and race-matched healthy controls were enrolled. Demographic, anthropometric, clinical and laboratorial data were collected using clinical interview and chart review. Serum 25-hydroxyvitamin D levels, parathormone, calcium and 24-hour urinary calcium were evaluated in all subjects. Bone mineral density and body composition were studied by dual X-ray absorptiometry. The mean age of patients and controls was 33 years. Weight (75.61 [20.73] vs. 63.14 [7.34] kg, p=0.009), body mass index (29.57 [7.17] vs. 25.35 [3.37] kg, p=0.014) and caloric ingestion (2493 [1005.6] vs. 1990 [384.1] kcal/day, p=0.03) were higher in PAPS than controls. All PAPS were under oral anticoagulant with INR within therapeutic range. Interestingly, biochemical bone parameters revealed lower levels of 25-hydroxyvitamin D [21.64 (11.26) vs. 28.59 (10.67) mg/dl, p=0.039], serum calcium [9.04 (0.46) vs. 9.3 (0.46) mg/dl, p=0.013] and 24-hour urinary calcium [106.55 (83.71) vs. 172.92 (119.05) mg/d, p=0.027] in patients than in controls. Supporting these findings, parathormone levels were higher in primary antiphospholipid syndrome than in controls [64.82 (37.83) vs. 44.53 (19.62) pg/ml, p=0.028]. The analysis of osteoporosis risk factors revealed that the two groups were comparable (p>0.05). Lumbar spine, femoral neck, total femur and whole body bone mineral density were similar in both groups (p>0.05). Higher fat mass [28.51 (12.93) vs. 20.01 (4.68) kg, p=0.005] and higher percentage of fat [36.08 (7.37) vs. 31.23 (4.64)%, p=0.010] were observed in PAPS in comparison with controls; although no difference was seen regarding lean mass. In summary, low vitamin D in primary antiphospholipid syndrome could be secondary to higher weight and fat mass herein observed most likely due to adipocyte sequestration. This weight gain may also justify the maintenance of bone mineral density even with altered biochemical bone parameters. Lupus (2010) 19, 1302-1306.

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Six Burkholderia solanacearum (formerly Pseudomonas solanacearum) genomic DNA fragments were isolated, using RAPD techniques and cloning, from the three genetically diverse strains: ACH092 (Biovar 4), ACH0158 (Biovar 2) and ACH0171 (Biovar 3) (1). One of these cloned fragments was selected because it was present constantly in all bacterial strains analysed. The remaining five clones were selected because Southern hybridisation revealed that each showed partial or complete specificity towards the strain of origin. A seventh genomic fragment showing a strain-specific distribution in Southern hybridisations was obtained by differential restriction, hybridisation and cloning of genomic DNA. Each of these clones was sequenced and primers to amplify the insert were designed. When DNA from the strain of origin was used as template, PCR amplification for each of these fragments yielded a single band on gel analysis. One pair of primers amplified the species-constant fragment of 281 bp from DNA of all B. solanacearum strains investigated, from DNA of the closely related bacterium which causes ''blood disease'' of banana (BDB) and in P. syzigii. The sensitivity of detection of B. solanacearum using these ubiquitous primers was between 1.3 and 20 bacterial cells. The feasibility and reliability of a PCR approach to detection and identification of B. solanacearum was tested in diverse strains of the bacterium in several countries and laboratories.

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Background: Since the cell therapy benefits for myocardial infarction are mainly related to infarct reduction by regenerating lost myocardium or increasing survival of tissues at risk, we evaluated the effects of bone marrow-derived mononuclear cells (MNC), implanted after the completion of necrosis, on infarct progression and cardiac remodeling. Methods: After 48 h of induction of myocardial infarction (MI), Lewis-inbred rats were injected with 6 x 10(6) cells (MI + MNC) or saline (MI). After six weeks, scar dimension, ventricular morphology and function were analyzed by echocardiography followed by histomorphology of the infarcted and border zones. Results: After therapy, the relative size of the infarct was smaller in MI + MNC (37 +/- 1% of the left ventricle) than in MI (43 +/- 1%). While the MI group exhibited parallel elongation of the infarcted (31.6 +/- 3.8% increase) and reminiscent ventricular portions (33.5 +/- 3.7%), MNC therapy preserved the initial infarct length. Infarcted walls were thicker (979 +/- 31 mm) in the MNC group than in the untreated group (709 +/- 41 mm), also demonstrating an absence of infarct expansion. In the border zones, MNC led to increased capillary densities and capillary/myocyte ratios. The cardiac systolic function remained depressed in MI, but improved by 19 +/- 5% in MI + MNC which reduced the incidence of pulmonary arterial hypertension (37.5% in MI and 6.25% in MI + MNC). Conclusion: MNC therapy prevented the infarct expansion and thinning related to cardiac remodeling and was associated with an improvement of border zone microcirculation: as a result, MNC therapy reduced typical MI dysfunctional repercussions. (C) 2009 Elsevier Ireland Ltd. All rights reserved.