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51.
The aim of this study was to determine the age of appearance of secondary sexual characteristics in Iranian girls living in Tehran. A cross-sectional study was conducted between 2003 and 2004 on 1420 6–17-year-old females in different parts of Tehran. Data were collected on the basis of a multistage probability sampling. Secondary sexual characteristics were evaluated by inspection and palpation, and were recorded according to Tanner staging. The subjects were asked about the occurrence of menarche and the age of its onset. Generalized additive logistic modelling was used for the analysis of data. The median age (percentile 10–percentile 90) of Tanner 2 of breast development (B2) and Tanner 2 of pubic hair growth (P2) among 1136 girls was 9.74 years (8.23–11.94) and 10.49 years (8.86–12.17), respectively. The ages of the 2.5 percentile for B2 and P2 were 7.42 and 7.03 years, respectively, so the onset of puberty at <7 years and 5 months is considered precocious in this population. The median age of menarche in 399 girls was 12.68 years (11.27–15.96).  相似文献   
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Clinical Autonomic Research - Orthostatic intolerance (OI) is a group of disorders characterized by symptoms that occur upon standing and resolve with recumbence. Although well established but not...  相似文献   
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IntroductionEndodontic sealers play a vital role in the obturation of root canal space. The aim of this study was to evaluate the utility of a recently developed polyurethane expandable sealer (PES), along with its cytotoxicity and dimensional changes.MethodsL929 fibroblasts and an cell viability assay (MTS assay) were used to determine the cytotoxicity of dental sealers (AH Plus [Dentsply Maillefer, Ballaigues, Switzerland], Sure-Seal Root [Sure Dent Corporation, Gyeonggi-do, South Korea], and the PES) at 24, 48, 72, and 96 hours. An advanced choroidal neovascularization model was used to assess the effect of these sealers on angiogenesis. Thirty-six extracted single-rooted human teeth were prepared and randomly divided into 3 groups (n = 12). Obturation was performed with gutta-percha and a sealer using lateral compaction as follows: group 1, AH Plus; group 2, Sure-Seal; and group 3, PES. The average depth of sealer penetration into dentinal tubules was measured with a scanning electron microscope. Data were analyzed using 1-way analysis of variance and post hoc Tukey tests (level of significance, P < .05).ResultsThe values of MTS, choroidal neovascularization, and the penetration depth of PES were significantly higher than in other experimental groups (P < .05). The lowest values were noted in specimens of AH Plus, whereas the highest were detected in the PES group.ConclusionsPES showed promising results in terms of biocompatibility and dentinal tubule adaptation and penetration.  相似文献   
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OBJECTIVES: We tested whether long-term administration of antioxidant vitamins C and E improves coronary and brachial artery endothelial function in patients with coronary artery disease (CAD). BACKGROUND: Endothelial function is a sensitive indicator of vascular health. Oxidant stress and oxidized low-density lipoprotein (LDL) impair endothelial function by reducing nitric oxide bioavailability in the artery wall. METHODS: We randomly assigned 30 subjects with CAD to combined vitamin E (800 IU per day) and C (1000 mg per day) or to placebos in a double-blind trial. Coronary artery endothelial function was measured as the change in coronary artery diameter to acetylcholine infusions (n = 18 patients), and brachial artery endothelial function was assessed by flow-mediated dilation (n = 25 patients) at baseline and six months. Plasma markers of oxidant stress (oxidized LDL and autoantibodies) were also measured. RESULTS: Plasma alpha-tocopherol (p < 0.001) and ascorbic acid (p < 0.02) increased with active therapy. Compared to placebo, there was no improvement in coronary and brachial endothelial vasomotor function over six months. Although vitamins C and E tended to reduce F2-isoprostanes (p = 0.065), they failed to alter oxidized LDL or autoantibodies to oxidized LDL. CONCLUSIONS: Long-term oral vitamins C and E do not improve key mechanisms in the biology of atherosclerosis or endothelial dysfunction, or reduce LDL oxidation in vivo.  相似文献   
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PurposeDevelopmental dysplasia of the hip (DDH) is a term used to cover a broad spectrum of anomalies ranging from mild dysplasia to high-riding dislocations. We report the management of DDH in children using the Dega osteotomy and their long-term follow-up.MethodsFifty-eight hips from 48 children younger than 8 years treated using the Dega osteotomy between January 1988 and October 2000 were included in this multcenter study. Both prospective (41 hips) and retrospective (17 hips) cases were included, and follow-up was for a minimum of 13 years. Radiographs were made preoperatively, immediately postoperatively, after 6 weeks or at removal of the spica cast if any, at 6-month intervals and/or as indicated for 3 years postoperatively and then on annual basis until the last follow-up. A single-cut computed tomographic scan was performed for all prospective patients. Special attention was paid to the predictive measures of hip arthrosis and the survival of the hip after Dega osteotomy. ResultsThe final clinical outcome was favorable in 44 hips (75.9 %). Eleven hips needed a second surgery (acetabuloplasty and/or arthroplasty) during the follow-up period.Conclusions In our pediatric patient population the Dega osteotomy proved to be an adequate measure for the management of this complex condition. The worst complication was avascular necrosis, and all of the affected hips ended with failure (pain, another surgery, or both).  相似文献   
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Background and study aims

Helicobacter pylori (H. pylori) has been implicated in the pathogenesis of most important gastro-duodenal diseases, such as gastritis, peptic ulcer disease (PUD) and gastric cancer. H. pylori upregulates the expression and activity of several matrix metalloproteinases (MMPs) in the gastric mucosa, but the role of MMP-3 and MMP-9 in infected patients with H. pylori have not been clearly defined yet. We examined mucosal MMP-3 and MMP-9 mRNA levels in gastric mucosa of H. pylori infected patients and evaluated the effects of virulence factors cagA and vacA allelic variants on these levels. We also determined correlation between mucosal MMP-3 and MMP-9 mRNA levels and types of disease.

Patients and methods

Total RNA was extracted from gastric biopsies of 50 H. pylori-infected patients and 50 H. pylori-negative patients. Mucosal MMP-3 and MMP-9 mRNA expression level in H. pylori-infected and non-infected gastric biopsies were determined by real time-polymerase chain reaction (PCR). Presence of vacA (vacuolating cytotoxin A) and cagA (cytotoxin associated gene A) virulence factors were evaluated using PCR.

Results

The levels of MMP-3 in gastric mucosa were not different between H. pylori-positive and H. pylori-negative patients. There was no correlation between MMP-3 mRNA expression and virulence factor (cagA and vacA allelic variants) and the different types of disease (gastritis and PUD) in infected patients. But MMP-9 mRNA expression was significantly higher in biopsies of H. pylori-infected patients compared to H. pylori-negative patients. Also mucosal MMP-9 mRNA expression in H. pylori-infected patients was significantly associated with cagA status PUD.

Conclusion

Our results suggest that MMP-9 might be involved in the pathogenesis of H. pylori. PUD could be associated with cag PAI-dependent MMP-9 upregulation.  相似文献   
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