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 analyze the association between mtDNA mutations and photodamagc after ultraviolet B (UVB) irradiation. Methods Primary human skin fibroblasts (HSF) and primary human epi- dermal keratinocytes of adult (HEKa) were irradiated by sub-lethal doses of UVB thrice a day for 4-5 days. Thereafter, genomic DNA was extracted from irradiated cells and conventional PCR was applied to detect the frequency rates of 4977 bp and 3895 bp mtDNA deletion. To quantitatively analyze the mutation levels, SYBR Green real-time PCR method was performed. Results In both cell lines, the frequency rates and relative copy number of deletions increased with the cumulative doses of UVB exposure (P<0.05). The prevalence rate of 3895 bp deletion peaked 53.3% and and relative copy number reached (49.63±4.38)×10-5, showing a more intense response to the accumulation of UVB radiation than 4977 bp deletion. In HSF, the minimum cumu- lative dose of UVB radiation was 150 mJ/cm2 for the induction of 3895 bp deletion, and 200 mJ/cm2 for the induction of 4977 bp deletion. It seemed that mtDNA deletion was more readily to be induced by UVB radia- tion in HSF than in HEKa. Conclusions The development and accumulation of mtDNA mutation are intimately related with cumulated UVB dose received by skin cells, and the 3895 bp deletion is more reliable in moni- toring the photodamage caused by UV than 4977 bp deletion. Therefore, the 3895 bp deletion may serve as a biomarker for the detection of photodamagc in skin cells. HSF appear to have an increased susceptibility to UVB radiation, which results in a higher frequency and level of mtDNA mutations compared with HEKa.

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 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.

Objective To study the effects of iodine deficiency during pregnancy on fetal iodine metabolism and thyroid function. Methods Wistar dams were randomly divided into four groups: severe iodine deficiency(SID), moderate iodine deficiency(MoID), mild iodine deficiency(MiID) and normal iodine(NI). All the dams were fed with iodine deficient food(iodine contents: 50 μg/kg) and drinking water with different doses of KI (0,54.9,163.8,381.7 μg/L) for 3 months till mating. Iodine was supplied at the dose of 1.24 μg/d(SID), 2.50 μg/d(MoID), 5.00 μg/d(MiID) and 10.00 μg/d(NI), respectively. The dams and their fetuses on gestation of 20 days were studied. Urine iodine of dams and iodine contents in fetal amniotic fluid were measured by As3+-Ce4+catalytic spectrophotometry using ammonium persulfate digestion. And blood iodine in pregnant rats and iodine contents in placental tissue were measured by As3+-Ce4+catalytic spectrophotometry in dry ash of samples in KClO3-ZnSO4-K2CO3-NaCl. Thyroid hormone levels in mother serum and in fetal amniotic fluid were detected by chemiluminascent assay, and their thyroid glands were weighted and carefully observed. Results ①Iodine content in urine and blood of pregnant rats and amniotic fluid of fetal rats reduced along with their decrease of iodine supply. Urine iodine median of rats in 4 groups(NI: 353.7 μg/L; MiID: 115.9 μg/L; MoID: 26.9 μg/L; SID: 0 μg/L) were statistically significant(χ2=32.884, P < 0.01). Blood iodine level in MoID and SID[(29.4±18.6), (11.7± 7.0)μg/L]was significantly lower than that in NI[(49.1±23.0)μg/L, P < 0.05 or < 0.01]. In iodine deficiency groups, there was a decreasing trend in iodine contents of fetal amniotic fluid[MiID: (48.3±23.1)μg/L; MoID: (29.2±14.7)μ/L; SID:(19.5±6.7)μg/L]and an increasing tendency in iodine contents of placental tissue [MiID: (0.57±0.26)μg/g, MoID: (0.53±0.34)μg/g; SID: (0.53±0.15)μg/g], but there was no statistical significance(P>0.05). ②In SID, TT4[(14.3±4.1)nmol/L]and FT4[(10.8±3.6)pmol/L]were lower than that in NI[(28.4±19.3)nmol/L, (20.2±8.0)pmol/L, P < 0.05 or < 0.01], while that in MoID[(22.1±6.1)nmol/L, (18.5±4.1)pmol/L]and MiID[(25.5±13.1)nmol/L, (18.6±8.4)pmol/L]were decreased without statistical significance(P > 0.05). And FT3/FT4 ratio(0.34±0.16), absolute[(48.4±22.7)mg]and relative weights[(144± 76)mg/kg]of thyroid gland in pregnant rats were respectively higher than that in NI[0.16±0.02, (19.5±3.1)mg, (66±10)mg/kg, P<0.01]. But that in MoID[0.19±0.04, (27.0±5.7)mg, (84±19)mg/kg]and MiID[0.17± 0.06, (25.0±8.9)mg, (78±25)mg/kg]were increased without statistical significance(P > 0.05). A visibly congestive enlargement thyroid was found in SID, while thyroid mildly enlarged in MoID and MiID. ③Compared with NI [(2.38±1.55)pmol/L,0.50±0.18], the FT4 levels [(1.07±0.87) pmol/L]in amniotic fluid were significantly decreased (P < 0.05) and the FT3/FT4 ratio (1.96±0.61) was significantly increased (P < 0.01) in SID. There were no statistical significances(P > 0.05) in other 3 groups[MiID: (2.77±0.90)pmol/L,0.46±0.15; MoID: (2.35±0.76)pmoL/L,0.61±0.21]. A visible thyroid enlargement with hyperemia was observed in SID fetus while in other 2 experiment groups their thyroids were only mildly congested. Conclusions Severe iodine deficiency during pregnancy can result in both mother and fetus overt hypothyroidism. The fetal thyroid hormone levels in mild iodine deficiency status is close to normal levels because of maternal and placental compensation. Moreover, both the dam and the fetus suffer from the negative effects in moderate iodine deficiency during pregnancy.

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 compare the proliferation and osteogenic differentiation between human bone marrow mesenchymal stem cells from orofacial bone(OMMSCs)and those from long bone(BMMSCs).Methods:OMMSCs were isolated from orthognathic surgical sites and cultured by limited dilution.BMMSCs were obtained from bone marrow of volunteers and isolated by density gradient centrifugation method.The surface markers of the cells were detected by flowcytometry.Single-colony formation,CCK assay and cell circle analyses were conducted.Osteogenic differentiation ability was evaluated by ALP activity test and Alizarin red staining after osteogenic induction culture.Results:The cell surface markers STRO-1 and CD105 of both stem cells were positive,CD34,CD31 and CD45 were negative. OMMSCs generated significantly higher numbers of colonies than BMMSCs.In addition,OMMSCs had a higher proliferation rate and more cells in proliferative(S +G2 )stage than BMMSCs.After osteogenic induction for 3,5,7 and 10 d,OMMSCs showed higher levels of ALP activity.OMMSCs formed significantly more mineralized nodules than BMMSCs after 21-day ostogenic induction.Conclusion:The proliferation and osteogenic differentiation capacity of OMMSCs are higher than those of BMMSCs.

Objective To evaluate the ability of diffusion-weighted imaging (DWI)in differentiating pancreatic carcinoma from chronic lump type pancreatitis. Methods Totally 38 cases of pancreatic cancer, 9 cases of chronic lump type pancreatitis, 15 cases of normal patients underwent DWI. DWI with b value＝0, 500, 1 000 s/mm2 was performed twice. Apparent diffusion coefficient (ADC) was measured by analysis of imagines of ADC. Results The mean ADC value of 38 subjects with pancreatic carcinoma was (1.411± 0.101)×10-3 mm2/sec, the mean ADC value of 9 subjects with lump type pancreatitis was (1.053±0.113) ×10-3 mm2/sec, and the mean ADC value of normal pancreas subjects was (1.245±0.112)×10-3 mm2/s. The difference between the three groups were statistically significant (P＜0.05). Conclusions DWI may have the clinical potential to differentiate chronic lump type pancreatitis from pancreatic carcinoma.

ABSTRACT:Objective To explore the clinical value of improved body position in improving one-time success rate of PICC and reducing incidence rate of complications during PICC.Methods A total of 120 patients with lung cancer surgery were randomly divided into traditional body po-sition group and improved body position group.One-time success rate and incidence rate of com-plications during PICC were compared between two groups.Results There was significant differ-ence in one-time success rate of PICC between semi-reclining position group and supine group (P <0.05).Compared with the supine group,the time of PICC in the semi-reclining position group was significantly shorter (P <0.05),and the incidence rates of local edema and local inflam-mation around puncture point was significantly lower (P <0.05).Conclusion The modified semi-reclining position can effectively improve one-time success rate of PICC and reduce the inci-dence rates of misplaced PICC and complications.

ABSTRACT:Objective To explore the clinical value of improved body position in improving one-time success rate of PICC and reducing incidence rate of complications during PICC.Methods A total of 120 patients with lung cancer surgery were randomly divided into traditional body po-sition group and improved body position group.One-time success rate and incidence rate of com-plications during PICC were compared between two groups.Results There was significant differ-ence in one-time success rate of PICC between semi-reclining position group and supine group (P <0.05).Compared with the supine group,the time of PICC in the semi-reclining position group was significantly shorter (P <0.05),and the incidence rates of local edema and local inflam-mation around puncture point was significantly lower (P <0.05).Conclusion The modified semi-reclining position can effectively improve one-time success rate of PICC and reduce the inci-dence rates of misplaced PICC and complications.