BACKGROUND:Constant magnetic field of proper intensity can inhibit the proliferation of vascular smooth muscle cells,and it can be used to inhibit the restenosis following percutaneous coronary intervention.OBJECTIVE: To observe the effect of constant magnetic field of different intensities on the expression of osteopontin gene in rat aorta smooth muscle cells, so as to investigate whether magnetic field can be used to prevent and treat restenosis following percutaneous coronary intervention.DESIGN: A randomly grouping and controlled observation.SETTING: Department of Cardiology, Xijing Hospital of the Fourth Military Medical University of Chinese PLA.MATERIALS: The experiments were carried out in the laboratory of Department of Cardiology (Military Institute of Cardiovascular Disease), Xijing Hospital of the Fourth Military Medical University of Chinese PLA from February to December in 2006. Male pure SD rats of 200-250 g were used.METHODS : Rat aorta smooth muscle cells were cultured in vitro in DMEM medium containing fetal bovine serum (0.1 in volume serum), and then the cells were randomly divided into control group, constant magnetic field of 1, 5, 10 and 50 Gs groups, those in the control group were not treated with magnetic field, and those in the other groups were treated with magnetic field and cultured for another 48 hours. Reverse transcription-polymerase chain reaction and Western blotting were combined with absorbance (A) scanning analysis to observe the effect of constant magnetic field on the expressions of osteopontin and its mRNA in smooth muscle cells.MAIN OUTCOME MEASURES: Expressions of osteopontin and its mRNA in smooth muscle cells.RESULTS: The expressions of osteopontin and osteopontin genes in the constant magnetic field groups were significantly decreased as compared with that in the control group (P ＜ 0.05), there were also significant differences among the constant magnetic field groups of different intensities (P ＜ 0.05). It was indicated that the stimulation of constant magnetic field was in an intensity-dependent manner, and the expressions of osteopontin and osteopontin mRNA were enhanced as the intensity of magnetic field was increased.CONCLUSION: Constant magnetic field of proper intensity can inhibit the osteopontin expression in vascular smooth muscle cells on the gene level, and magnetic field may play a role in preventing and treating the restenosis following percutaneous coronary intervention.

Objective To introduce a new economical method which can be used for determination of urinary iodine of batch samples with low cost of arsenic trioxide,and decrease environmental pollution.Methods A catalytic spectrophotometry for measuring iodine content in a small volume of urine samples with low cost of arsenic and cerium was established based on the principle of ammonium persulfate digestion As3+-Ce4+ catalytic spectrophotometry.Ninety-six well polypropylene microplate was utilized as digestion and catalysis reaction vessel,conventional laboratory oven was used as a tool to digest and heat,ice plate was used to cool,and the absorbance was read with the Multimode Reader.The accuracy of the new method was evaluated with the current standard method (WS/T 107-2006) by simultaneous determination of urinary iodine of 24 urine samples.Results The linear range of this method was 0-300 μg/L,the linear correlative coefficient (r) was higher than 0.999,and the detection limit was 8.67 μg/L.The coefficient of variations was 2.15％,4.33％ and 3.48％ when measuring urine samples with high,medium and low iodine concentration,respectively.The test results of three national standard urinary iodine samples were all within the given value range and the relative deviation (RD) was-0.16％,1.81％ and-2.82％,respectively.The average recovery of the low concentration was 97.51％,and that of the high concentration was 96.01％.The two methods correlated well (r =0.995,P ＜ 0.01).Conclusions This method greatly reduces the arsenic waste,environmental pollution,consumables and labor.The new method is simple and efficient,accurate and reliable;it is suitable for application as a supplementary method for analyzing urinary iodine of a large number of samples.

OBJECTIVEThe term "premature thelarche" refers to isolated breast development before 8 years of age in female, without any other signs of sexual maturation, while "gynecomastia" is the presence of breast tissue in males. This study aimed to investigate the prevalence of premature thelarche and gynecomastia in Chinese infants and toddlers, identify the potential risk factors, and explore the influence of early breast development on physical growth, mental development and psychomotor development.

METHODA total of 1 510 full term and healthy children at the age of 0-48 months were sampled by stratified cluster random sampling method from 8 provinces from 2011-2012. Weight, height and breast development were assessed by senior primary pediatricians, while Bayley Scale of Infant Development-I (BSID-I) was used to measure the mental developmental index (MDI) and psychomotor developmental index (PDI) for children aged 2-30 months. Social-demographic Questionnaires were completed by the caregivers.

RESULTThe combined prevalence of premature thelarche and gynecomastia was 1.6% (23/1 475), girls 2.2% (15/695), boys 1.0% (8/780), all within 2 years of age. The birth weight, feeding patterns in first 4 months, delivery mode, weaning time and social economic status were not significantly associated with the breast development. However, lower father's education level (OR = 3.632, 95%CI = 1.565-8.432) as well as smoking mother (OR = 18.960, 95%CI = 1.590-226.304) were significantly related to breast development even after adjusting for potential confounders. Lower weight (-0.479 ± 0.648 vs. 0.005 ± 0.987, P < 0.05) and height (-0.602 ± 1.042 vs. 0.008 ± 0.986, P < 0.05) Z score were found in breast development group, even after adjusting for age, gender and father' education level. Neither mental development (t = -0.082, P > 0.05) nor psychomotor development (t = 1.054, P > 0.05) was associated with breast development.

CONCLUSIONWe showed a similar prevalence of premature thelarche with the data reported in similar studies reported from other countries. Among the 0-48 months old infants and toddlers, Father's education level and smoking mother were both related to breast development. Breast development was significantly associated with physical growth, but had no correlation with the mental or psychomotor development.

African Continental Ancestry Group ; Body Height ; Body Weight ; Breast ; growth & development ; Child Development ; Child, Preschool ; Cross-Sectional Studies ; Environmental Exposure ; Female ; Gynecomastia ; epidemiology ; etiology ; Humans ; Infant ; Infant, Newborn ; Male ; Multivariate Analysis ; Prevalence ; Puberty, Precocious ; epidemiology ; etiology

Objective : To explore the technology and efficacy of fabrication of a guide and removal of a fiber post by tetrahedron positioning technology at the chair side. Methods: For one patient with acute chronic periapical periodontitis of the left maxillary lateral incisor who needed to have the fiber post removed, the chair side tetrahedral positioning technique was used to make a guide plate to remove the fiber post. Cone beam CT (CBCT) data were imported into the software to design the guide plate for fiber post removal. The guide plate design on CBCT was transferred to a solid model by using tetrahedral positioning technology. The guide plate was made to guide the removal of the fiber post, and then left maxillary lateral incisor root canal was performed. We evaluated the effect of fiber post removal with tetrahedral positioning technology by reviewing the literature. Results : The guide plate made by tetrahedral positioning technology can accurately locate the position and direction of fiber posts at a low cost and with high speed. After the fiber post was removed, the root canal could be dredged by using root canal preparation instruments. After root canal preparation, the root canal was filled with warm gutta-percha to complete the root canal treatment. After 3 months, the apical radiograph showed that the transmission shadow of the apical area was reduced. The results of the literature review showed that the fiber post removal with guide plates provides a predictable result and a lower risk of iatrogenic damage. Minimally invasive treatment can be carried out, and chair time can be reduced. Conclusion On the basis of CBCT data, using tetrahedral positioning technology to make fiber post removal guides can help reduce the risk of fiber post removal and has the characteristics of speed, low cost and short chair side processing. However, the accuracy comparison between tetrahedral positioning technology and 3D printing guides needs further study.