Objective To explore the effects of iodine on apoptosis and proliferation of the thyroid cells. Methods Wistar rats of one month wean were randomly divided into five groups(low iodine-LI, normal iodine-NI, fivefold high iodine-5 HI, tenfold high iodine-10 HI, fiftyfold high iodine-50 HI), and fed on water containing different concentration of iodine. All groups got prospective iodine intake, that is 0.6, 6.15, 30.75, 61.5, and 307.5 mg/d. After 7 days, 14 days, 28 days, the rats were sacrificed. The proliferation, apoptosis, and apoptosis related genes expression in the thyroid cells were determined by TUNEL, immunohistochemistry and RT-PCR. Results As for short-term of iodine deficiency, no significant change was seen in the mRNA expression of fas and fasL genes, while in the iodine excess groups,the expreesion showed an up-regulation trend as iodine intake increased. Fas and FasL proteins expressions were consistent in LI and NI groups and all of them were negative or weak positive. In the HI groups the stain density increased with iodine intake and treatmnet period increased. Expression of PCNA was enhanced by short-term iodine deficiency, but not by short-term iodine excess. Apoptosis was not observed in all groups. Conclusion Both short-term iodine deficiency and iodine excess have no obvious effects on thyrocytes apoptosis. Proliferation can be induced by short-term iodine deficiency, not by iodine excess. Wistar rats present a strong tolerance to long-term iodine excess.

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.

Objective To achieve the fusion expression of the entire human beta-defensin-3(hBD-3) gene. Method We synthesized two oligonucleotide primers accor ding to the codon preference of Escherichia coli. The gene was cloned into p GEX -4T-2 to establish the pGEX-4T-2-hBD-3 as the fusion expression vector by PCR. Transformed into E.coli strain DH5α, the express vector was induced an d ex pressed by IPTG. The fusion protein GST-hBD-3 was obtained by repeated cycles of freezing and thawing, cut by thrombin to attain the recombinant hBD-3 protei n. Result The result of the antibacterial peptide agarose diffu sion assay shows the antibacterial activity of the rhBD-3 against the S.aureu s exists, and it reaches 0.843U. Conclusion The fusion expr ession of the hBD-3 gene is successful.

Objective To investigate the sodium iodide symporter (NIS) gene expression during different iodine intakes and its function in thyroid autoregulation. Methods BabL/c mice were randomly divided into five groups according to their different iodine intake levels : low iodine (LI), normal iodine (NI), five-fold iodine (5HI) ,ten-fold iodine (10 HI) and fifty-fold iodine (50 HI). After three months and six months administration, they were sacrificed and thyroids were excised. The mRNA and protein expression level were determined by real time quantitative PCR and immunohistochemistry respectively. Iodine content in thyroid tissue was measured with spectrophotometry and thyroid hormone level was measured with radioimmunoassay. Results Compared with NI group, NIS mRNA and protein expression was greatly increased in LI groups. Immunohistochemistry analysis indicated that NIS was mostly located at the basolateral membrane of thyrocyte,suggesting the improved activity in transporting iodine. But when faced with long-term and severe iodine deficiency, the iodine content in thyroid was finally decreased ,and hormone level lowered. On the other hand, in HI groups NIS mRNA and protein expression was greatly down-regulated. There was a tendency of decreasing NIS gene expression level with increasing doses of iodine intakes. In addition, NIS protein was found mainly in intracellular vesicles, rather than at the cell membrane,suggesting the loss of its activity. The iodine content in thyroid tissue was only slightly increased and was not consistent with the iodine intake levels. Conclusion These findings indicate that NIS may be. regulated at transcription, translation and post-translation levels. This phenomenon constitutes a highly specialized intrinsic autoregulatory system that protects thyroid from high doses of iodine, but at the same time ensures adequate iodine uptake for hormone biosynthesis. NIS plays a critical role in thyroid autoregulation mechanism.

Objective To study mother and infant's iodine metabolism and thyroid function during lactation with different iodine intakes. Methods Wistar rats were randomly assigned to four groups with severe iodine deficiency (SID), mild iodine deficiency (MiID), normal iodine (NI), and excessive iodine (ExI) intake respectively. All rats were fed on an iodine deficient food and drinking water with different quantities of potassium iodide for 3 months until mating. The urinary iodine, milk iodine, blood iodine, and thyroid hormones (TH) were detected in lactating mother and the offspring rats 14 days after birth. Thyroid weight of mother rats was determined. Thyroid morphology of mother and their offsprings was observed. Results ( 1) Iodine contents in urine, milk, and blood of lactating rats and the offsprings were increased with the increase of iodine supplied in diet. But the change in amplitude between groups was decreased in the other; urine iodine > milk iodine > blood iodine. (2) Serum TT4[ (16. 7±12. 0 vs 36.4±15. 0) nmol/L, P<0.05] was significantly decreased, but TSH [(5.73±2.90vs 1. 38±0.30)mIU/L, P<0.01]and TT3/TT4(6.6±2.7 vs 2. l±0.3,P<0.01) were increased in lactating rats of SID group compared with NI, so as TT4( 10.6±2. 3 vs 16.4±4. 7) nmol/L, P<0.05 ] of offspring rats in SID, but were not in MiID and ExI groups. (3 ) Histological studies showed that small follicular thyroid nodules with follicular hyperplasia occurred in both lactating rats and their offsprings in the SID group, mild swelling in MiID group and polymorphism changes appeared in mother rats of ExI group, but no significant difference appeared in offsprings compared with NI group. Conclusions Severe iodine deficiency will lead to hypothyroidism in mother and infant, but normal iodine nutrition and thyroid function in mother and offspring were maintained through the compensatory action of mother and child in mild iodine deficiency and iodine excess.

ObjectiveTo investigate the effects of maternal thyroid dysfunction during pregnancy caused by iodine deficiency of different degrees on doublecortin ( DCX ) and synaptophysin ( p38 ) expressions in fetal brain.Methods Wistar female rats were randomly divided into four groups:adequate iodine ( AI),mild iodine deficiency ( MiID ),moderate iodine deficiency ( MoID ),and severe iodine deficiency ( SID ),according to the total daily iodine supply( fed on an iodine deficient diet with different dosages of KI added in drinking water).Three months later the rats were mated.Serum TSH and thyroid hormones were determined in maternal rats on gestational day 20 using chemiluminescent immunoassay.The iodine contents in urine and histological changes of thyroid gland were observed in pregnant rats.The mRNA and protein levels of DCX and synaptophysin ( p38 ) were analyzed in fetal brain by using real time quantitative RT-PCR and western blotting respectively.Results( 1 ) Iodine contents in urine of pregnant rats were reduced with the decrease of their iodine supply.Compared with group AI,serum TSH was significantly increased [ ( 2.95 ± 1.70 vs 1.31 ± 0.55 ) mU/L,P ＜ 0.05 ],and both TT4 and FT4 were significantly decreased [ ( 14.3±4.1 vs 28.4±19.3 ) nmol/L,P＜0.05 ] and [ ( 10.8±3.6 vs 20.2±8.0) pmol/L,P＜0.01 ] in pregnant rats of SID group.Whereas,a slight rise in TSH,and a mild decline in both TT4and FT4 were found in MoID and MiID groups.However,there were no significant changes in TT3 and FT3 levels among these four groups.( 2 )Histological characteristics of thyroid gland in pregnant rats showed a typical goiter with small follicular hyperplasia and lack of colloid in SID group,moderate follicular hyperplasia with decreased colloid in MoID group; but mild cellular hyperplasia without decrease in follicular size and colloid in MiID group.( 3 ) The mRNA levels of DCX were increased in fetal brains of three iodine deficiency groups compared with AI group,but a statistical significance was found in MoID group.The protein levels of DCX in all experiment groups were significantly increased.Both mRNA and protein expressions of synaptophysin ( p38 )were significantly down-regulated in three iodine deficiency groups.Conclusions Maternal thyroid dysfunction caused by iodine deficiency,even by mild or moderate iodine deficiency,may lead to retardation of fetal neuronal and synaptic growth.

Objective To investigate therapeutic effects of β-TCP/PLGA scaffolds seeded bone marrow mesenchymal stem cells (BMSCs) combing with hyperbaric oxygen (HBO) on bone defect with seawater immersing in rabbit radius.Methods BMSCs were seeded into the β-TCP/PLGA scaffolds to construct tissue engineering bone.60 New Zealand rabbits were created 1.5 cm bone defect in bilateral radius,and then bilateral wound limbs were immersed in seawater for 3 h.After debridement,all rabbits were randomly divided into 4 groups.In group A nothing was implanted into the bone defect.Only BMSCs was implanted in group B.BMSCs + HBO was given in group C.β-TCP/PLGA BMSCs + HBO was given in group D.At postoperative 4,8,12 weeks rabbits were sacrificed after radiography radius.X-ray radiography,HE staining,immunohistochemical observation were used to evaluate repairing effect of bone defect with seawater immersing.Results Radiographic analysis demonstrated that the bone defects were completely repaired with recanalization of the medullary cavity in group D,bone defects were partially repaired with partal recanalization of the medullary cavity in group C,bone defects were incompletely repaired in group B;bone defect repair unfinished and the broken ends were sclerous in group A.Each time point group D＞group C＞group B＞group A in callus grey value (P＜0.05).HE staining indicated after 12 weeks,a small amount of lainellar bone formated in group A;a small amount of lamellar bone formated in group B;a large amount of lamellar bone formated in group C;a large amount of lamellar bone formated in group D.Immunohistoehemical result indicated at postoperative 4 weeks,the expressions of osteocalcin(OCN) in each group were at high levels,the expressions decreased significantly at Postoperative 8 weeks,the expressions were at a low level at postoperative 12 weeks.At postoperative 4 and 8 weeks,the expression levels of OCN were group D＞ group C＞ group B＞group A (P＜0.05),there was no significant difference at postoperative 12 weeks between the 4 groups (P＞0.05).Conelusion the β-TCP/PLGA composite BMSCs combined hyperbaric oxygen is the effective method to repair seawater immersed bone defect in rabbit.

Background: Job performance is known as an essential reflection of nursing quality. Colleague solidarity, positive emotion, and turnover intention play effective roles in a clinical working environment, but their impacts on job performance are unclear. Investigating the association between nurses’ colleague solidarity and job performance may be valuable, both directly and through the mediating roles of positive emotion and turnover intention. Methods: In this cross-sectional study, a total of 324 Chinese nurses were recruited by convenience sampling method from July 2016 to January 2017. Descriptive analysis, Spearman’s correlation analysis, and the structural equation model were applied for analysis by SPSS 26.0 and AMOS 24.0. Results: A total of 49.69% of participants were under 30 years old, and 90.12% of participants were female. Colleague solidarity and positive emotion were positively connected with job performance. The results indicated the mediating effects of positive emotion and turnover intention in this relationship, respectively, as well as the chain mediating effect of positive emotion and turnover intention. Conclusions In conclusion, dynamic and multiple supportive strategies are needed for nurse managers to ameliorate nursing job performance by improving colleague solidarity and positive emotion and decreasing turnover intention based on the job demand-resource model.