[The relationship between homocysteine, coagulation dysfunction and breast cancer risk]

Objective: To investigate the correlation of homocysteine (HCY) and coagulation function index with the risk of breast cancer and its clinicopathological characteristics. Methods: The HCY, coagulation function test index, and clinicopathological information of female breast cancer patients (333 cases) treated in Tianjin Medical University Cancer Hospital from January 2018 to December 2018 were collected, and female patients with benign breast (225 cases) were selected during the same period for the control group. The t-test was used to compare measurement data with normal distribution, D-Dimer data were distributed discreetly and described by median, non-parametric Mann-Whitney U test was used to compare the two groups. The chi-square test was used to compare enumeration data, and the Logistic regression analysis was used for the risk analysis. Results: The levels of HCY, fibrinogen (Fbg), protein C (PC), and median D-Dimer (D-D) in peripheral blood of breast cancer patients group [(13.26±5.24) μmol/L, (2.61±0.83) g/L, (117.55±19.67)%, and 269.68 ng/ml, respectively] were higher than those in the control group [(11.58±0.69) μmol/L, (2.49±0.49) g/L, (113.42±19.82)% and 246.98 ng/ml, respectively, P<0.05]. The prothrombin time (PT), PT(INR), α2-antiplasmin (α2-AP) levels [(10.19±0.63) s, 0.91±0.07 and (110.64±13.93)%, respectively] were lower than those in the control group [(10.58±0.65) s, 0.93±0.01 and (123.81±14.77) %, P<0.05]. The serum levels of PC and median D-D in premenopausal breast cancer patients [(112.57±17.86)% and 242.01 ng/ml, respectively] were higher than those in the control group [(105.31±22.31)% and 214.75 ng/ml, respectively, P<0.05]. The levels of PT(INR), α2-AP [0.91±0.07 and (111.29±12.54)%, respectively] were lower than those of the control group[0.98±0.15 and (120.17±16.35)%, respectively, P<0.05]. The levels of HCY and median D-D in postmenopausal breast cancer patients [(14.25±5.76) μmol/L and 347.53 ng/ml, respectively] were higher than those in the control group [(11.67±2.38) μmol/L and 328.28 ng/ml, P<0.05]. The levels of PT, PT(INR), antithrombin Ⅲ (AT-Ⅲ), α2-AP levels [(10.18±0.66) s, 0.87±0.09, (97.30±12.84)% and (110.13±14.96)%] were lower than those in the control group [(10.38±0.61) s, 0.90±0.08, (102.89±9.12)%, and (127.05±12.38)%, respectively, P<0.05]. The levels of α2-AP and median D-D in T2-4 stage breast cancer patients [(111.69±14.41)% and 289.25 ng/ml, respectively] were higher than those in Tis-1 stage patients [(108.05±12.37)% and 253.49 ng/ml, respectively, P<0.05]. The levels of PT, PT (INR), Fbg, AT-Ⅲ, α2-AP, median D-D [(10.62±0.63) s, 0.95±0.06, (3.04±1.52) g/L, (103.21±9.45)%, (118.72±14.77)% and 331.33 ng/ml, respectively] in breast cancer patients with lymph node metastasis were higher than those of patients without lymph node metastasis [(10.42±0.58) s, 0.93±0.06, (2.52±0.54) g/L, (95.20±13.63)%, (106.91±13.13)% and 263.38 ng/ml, respectively, P<0.05]. In non-menopausal breast cancer patients, the level of HCY [(12.63±4.41) μmol/L] in patients with T2-4 stage was higher than that of patients with Tis-1 stage [(10.70±3.49) μmol/L, P=0.010], and the level of thrombin time [(19.35±0.90) s] of patients with T2-4 stage was lower than that of patients with Tis-1 stage [(19.79±1.23) s, P=0.015]. The levels of PT(INR), Fbg, AT-Ⅲ, α2-AP [0.97±0.56, (3.37±2.34) g/L, (102.38±8.77)% and (120.95±14.06)%] in patients with lymph node metastasis were higher than those of patients without lymph node metastasis [0.94±0.05, (2.36±0.48) g/L, (94.56±14.37)% and (109.51±11.46)%, respectively, P<0.05]. Among postmenopausal breast cancer patients, the levels of AT-Ⅲ and α2-AP in T2-4 stage patients [(98.48±11.80)% and (111.84±15.35)%, respectively] were higher than those in patients with the Tis-1 stage [(94.12±14.98)% and (105.49±12.89)%, respectively, P<0.05]. The levels of AT-Ⅲ and α2-AP in N1-3 stage patients [(103.74±9.94)% and (117.29±15.23)%] were higher than those in N0 stage patients [(95.75±13.01)% and (108.39±14.42)%, P<0.05]. Conclusions: HCY and abnormal coagulation function are related to the risk of breast cancer, T stage and lymph node metastasis in breast cancer patients.

[Mechanism of Mycobacterium tuberculosis on interleukin-6 receptor 3'-untranslated region methylation in CD4+T cells]

Objective: To investigate the role and mechanism of DNA methylation in Mycobacterium tuberculosis (MTB lysate) -induced downregulation of interleukin-6 receptor(IL-6R) expression in CD4⁺T cells. Methods: A prospective study was conducted. Bisulfite sequencing (BSP) was applied to determine the methylation levels of CpG island in IL-6R promoter region and 3'untranslated region (3'UTR) region in CD4⁺T cells from peripheral blood mononuclear cells (PBMC) of control group (healthy person, n=10) and TB group (tuberculosis patients, n=10) in Shenzhen Third People's Hospital between 2019 and 2020. Quantitative reverse transcription-PCR (RT-qPCR) and Western blotting were used to detect the expression of IL-6R, DNMT1, DNMT3A and DNMT3B in MTB lysate-stimulated CD4⁺T cells and Jurkat E6-1 cells. Furthermore, PBMC in control group and Jurkat E6-1 cells activated by anti-CD3/CD28 antibody were stimulated by MTB lysates to detect the methylation levels of CpG island and IL-6R and DNMT expression. Transcriptional activity of differently methylation regions of IL-6R 3'UTR was detected by using luciferase reporter gene system. Results: IL-6R expression in TB group was lower than that in control group, but DNMT1 and DNMT3B expressions were higher than those in control group in CD4⁺T cells isolated from PBMC. There was no significant difference in the methylation rate of IL-6R promoter CpG island of CD4⁺T cells between control and TB group. However, the methylation rates of CpG island in 3'UTR region were significantly higher (P<0.001) in TB (69.5%±3.4%), compared with control (54.3%±4.7%). Besides, IL-6R expression was lower than unstimulated, while DNMT1 and DNMT3B expression was higher than unstimulated after MTB lysate-stimulation of activated control PBMC in vitro. The methylation rate of CpG island in IL-6R 3'UTR region of CD4⁺T cells increased from 58.8%±11.6% to 79.4%±10.9% (P<0.001) after MTB lysate-stimulated PBMC of the control. The same results were observed in the MTB lysate-stimulated CD4⁺T cells isolated from PBMC in control and Jurkat E6-1 cell line. Furthermore, IL-6R expression after co-treatment of the DNA methyltransferase inhibitor decitabine (5-aza) with MTB lysate was higher than that stimulated by MTB lysate alone. In addition, the methylation levels of CpG islands in the 3' UTR region of IL-6R were lower than those stimulated by MTB lysates alone after co-treatment of the DNA methyltransferase inhibitor decitabine (5-aza) with MTB lysates. The transcriptional activity of the fully unmethylated IL-6R 3'UTR CpG island reporter gene was higher than that of the fully methylated IL-6R 3'UTR CpG island. Conclusions: MTB lysates stimulation inhibited IL-6R expression transcriptionalely as well as on the protein level by inducing hypermethylation of CpG island in IL-6R 3'UTR region of CD4⁺T cells. The hypermethylation of CpG island in IL-6R 3'UTR region of CD4⁺T cells induced by MTB may be related to the increased expression of DNMT1 and DNMT3B.

[Survey on tobacco use and associated factors in population in Shandong province, 2016-2017]

Objective: To understand the status of tobacco use and related influencing factors in population in Shandong province. Methods: Stratified multi-stage cluster sampling was used to select respondents from 216 villages (communities) of 36 districts (counties) in Shandong province. Influencing factors on smoking were analyzed by logistic regression model. Results: The adequate sample size was 6 271 participants. After complex weighted, the current smoking prevalence was 23.93%,45.58% in males and 1.18% in females. The Public's smoking rates varied widely among different groups in the population. 45-64 age group had the highest smoking rate (25.07%). Smoking rates were substantially different in education levels, with the highest in junior high school (28.94%). The rate was higher in the rural area (24.98%) than that in the urban areas (23.08%). The average daily smoking rate was 20.23%. The average age of initiating smoking was 21.21 years. The average daily cigarette intake was 16.31 cigarettes. Among all the former and current smokers, the quitting rate was 20.79%. Multiple logistic regression model analysis showed that gender, age, occupation, region, and health knowledge score were correlated with smoking behavior. The current smoking rate of men was much higher than that of women (OR=49.625, 95%CI: 37.832-65.093). The current smoking rate in 45-64 age group was higher than that in the 15-24 age group (OR=1.830, 95%CI: 1.048-3.194). The current smoking rate of medical (OR=0.403, 95%CI: 0.187-0.866) and retired personnel (OR=0.648, 95%CI: 0.481-0.873) were lower than those engaging in agriculture, forestry, animal husbandry and the fishery ,respectively. The prevalence of residents living in the central part showed lower rate on current smoking than that in the eastern region (OR=0.724, 95%CI: 0.606-0.865). The current smoking prevalence of smoke hazard in 1-3 score group was higher than that in the group with 4-6 score (OR=1.432, 95%CI: 1.240-1.654). Conclusions: Smoking rate in adults in Shandong remained stable and at a high level. Comprehensive intervention measures such as tobacco control and health education should be carried out to reduce the smoking rate.

[Study on the relationship between smoking behavior and health literacy among grade 4-6 primary students in Shandong province]

Objective: To investigate the associations between smoking and literacy on health among 4-6 grade primary school students. Methods: A questionnaire survey was conducted to research on health literacy and smoking among 4-6 grade pupils in Shandong province, through a multi-stage stratified cluster random sampling method. Sociodemographic characteristics, health literacy level and smoking rate were collected from respondents. Binary logistic regression analysis was used to evaluate the association of smoking and health literacy. Results: A total of 9 240 questionnaires were distributed, with the rate of valid response as 99.7%. The current smoking rate of the students was 2.6%, on higher in boys (3.1%) than in girls (2.0%). 60.8% of 4-6 grade students were found to have adequate health literacy level. Levels of literacy health in both boy and girl school students appeared 56.7% and 64.9%, respectively. Results indicated that health literacy in smokers (14.4%) was lower than that in non-smokers (62.0%). Results from the binary logistic regression analysis showed that the independent influencing factors would include grade, father's education level, economic situation of the family, self-assessment on the school record and literacy on health (P<0.01). After controlling the other independent variables, the smoking rate was 8.62 (1/0.116) times in students with low literacy level on health, than those with high literacy level. Conclusions: Literacy on health was significantly associated with smoking in the 4-6 grade pupils of Shandong province.

Overexpression of EPS8L3 promotes cell proliferation by inhibiting the transactivity of FOXO1 in HCC

The homology of epidermal growth factor receptor pathway substrate 8 (EPS8), EPS8L3, is elevated significantly in hepatocellular carcinoma (HCC) tissues and cell lines compared with the normal liver tissues and cell lines. The MTT and colony formation assays demonstrated that overexpressing EPS8L3 enhances, while silencing reduces the proliferation of HCC cells. Further experiments illustrated that overexpressing EPS8L3 promotes the expression of p-AKT, Cyclin D1, but inhibits the transcriptional activity of FOXO1. Besides, colony formation assay demonstrated that AKT inhibitor suppresses the effect of EPS8L3 on proliferation in EPS8L3-overexpressing cells, whereas AKT restores the proliferation of EPS8L3-silenced cells, suggesting that EPS8L3 might promote proliferation by hyperactivating the AKT signaling pathway and subsequently inhibiting the FOXO1 transcriptional activity. Our results provide new view between EPS8L3 and progression of human HCC, suggesting that EPS8L3 may be a novel therapeutic target for HCC.

[Clinicopathological and ultrasound characteristics of extranodal extension in metastatic papillary thyroid carcinoma patients]

Objective: To explore clinicopathological and ultrasound characteristics of extranodal extension in metastatic papillary thyroid carcinoma patients. Methods: 176 patients with papillary thyroid carcinoma who were diagnosed in Tianjin Medical University Cancer Institute and Hospital between March 2011 and March 2016 were identified and recruited in the study. Among the 176 patients, 59 patients were diagnosed with regional lymph nodes metastasis accompanied with extranodal extension (extranodal extension positive group), 117 patients were regional lymph nodes metastasis without extranodal extension (extranodal extension negative group). The clinicopathological and ultrasound characteristics between extranodal extension positive group and extranodal extension negative group were also discussed in this article. Results: 59 patients were diagnosed with regional lymph nodes metastasis accompanied with extranodal extension (extranodal extension positive group). Single lymph node region of extranodal extension was identified in 40 patients, while 19 patients were confirmed with more than 2 regions of extranodal extension. The most frequent extranodal extension were detected in region Ⅵ lymph nodes(32 cases), following by Ⅲ(25 cases), Ⅳ(16 cases), Ⅱ(11 cases). In the aspect of ultrasound characteristics, metastatic papillary thyroid carcinoma with extranodal extension showed a higher incidence of node matting[13.6%(8/59) vs 3.4%(4/117), P=0.022], micro-calcification[66.1%(39/59) vs 46.2%(54/117), P=0.016], cystic[28.8%(17/59) vs 12.8%(15/117), P=0.013], aspect ratio(L/S)<2[88.1%(52/59) vs 75.2%(88/117), P=0.032] and larger diameter(1.95±1.01 cm vs 1.63±0.94 cm, P=0.028). Logistic multivariate analysis demonstrated that node matting (P=0.025) and cystic (P=0.026) were independent risk factors for extranodal extension. Conclusion: Node matting, micro-calcification, cystic, aspect(L/T)>2 and larger diameter were associated with extranodal extension in metastatic papillary thyroid carcinoma patients, especially node matting and cystic, which might help topre-operative ultrasound diagnosis of extranodal extension.

Structural and dynamical characteristics of flow units in metallic glasses

The metallic glasses (MGs) are conjectured to be heterogeneous—their microscopic structures are embedded with localized, soft and loosely packed atomic regions, which are termed as flow units (FUs). Detailed knowledges on the structure and dynamical features of FUs are essential for understanding the plasticity of MGs. In our study, by performing dynamical tests on MGs in molecular dynamics simulations, we show that mechanical hysteretic loops are formed in the strain-stress curves due to the undergoing plastic events. By analyzing the activated times of each atom in different dynamical tests, we map the exact locations of FUs and the distribution of their activation probability in the initial structure of MGs. More importantly, we demonstrate that the FUs are indeed liquid-like according to the Lindemann criterion of melting.

Identification of genes associated with castration‑resistant prostate cancer by gene expression profile analysis

Prostate cancer (CaP) is a serious and common genital tumor. Generally, men with metastatic CaP can easily develop castration‑resistant prostate cancer (CRPC). However, the pathogenesis and tumorigenic pathways of CRPC remain to be elucidated. The present study performed a comprehensive analysis on the gene expression profile of CRPC in order to determine the pathogenesis and tumorigenic of CRPC. The GSE33316 microarray, which consisted of 5 non‑castrated samples and 5 castrated samples, was downloaded from the gene expression omnibus database. Subsequently, 201 upregulated and 161 downregulated differentially expressed genes (DEGs) were identified using the limma package in R and those genes were classified and annotated by plugin Mcode of Cytoscape. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using Database for Annotation, Visualization and Integrated Discovery and KEGG Orthology Based Annotation System 2.0 online tools to investigate the function of different gene modules. The BiNGO tool was used to visualize the level of enriched GO terms. Protein‑protein interaction network was constructed using STRING and analyzed with Cytoscape. In conclusion, the present study determined that aldo‑keto reductase 3, cyclin B2, regulator of G protein signaling 2, nuclear factor of activated T‑cells and protein kinase C a may have important roles in the development of CRPC.

[A case of congenital cyst of epiglottis caused by severe upper respiratory tract obstruction]

The main clinical manifestations were respiratory distress，perioral cyanosis and Upper respiratory obstruction symptoms.The epiglottis opened by laryngoscope,can see a gray white semi elliptical sacs.Clinical diagnosis:congenital cyst of epiglottis.

Mechanical Relaxation-to-Rejuvenation Transition in a Zr-based Bulk Metallic Glass

The relaxation of amorphous materials, i.e., aging, would largely endanger their performances in service. Here we report a mechanical relaxation-to-rejuvenation transition of a Zr35Ti30Be27.5Cu7.5 bulk metallic glass (BMG) in elastostatic compression at ambient temperature, thus provide an accessible way to tailor the mechanical properties of amorphous materials. To unravel the structural evolution underlying the observed transition, atomistic simulations parallel with the experimental tests on a typical model glass system Zr60Cu40 were performed, which successfully reproduced and thus upheld the experimentally observed mechanical relaxation-to-rejuvenation transition. The variations of coordination number and atomic volume during the transition are evaluated to indicate a de-mixing tendency of the constituent atoms in the rejuvenation stage. This de-mixing tendency largely explains the difference between mechanical rejuvenation and thermal rejuvenation and reveals a competitive relationship between activation enthalpy and activation entropy in the stress-driven temperature-assisted atomic dynamics of BMG, such as diffusion and plastic deformation etc.

Protein-protein interaction between ezrin and p65 in human breast cancer cells

Our study aimed to investigate the co-localization and protein-protein interactions between ezrin and p65 in human breast cancer cells. Liquid chromatography-mass spectrometry (LCMS) was used to uncover novel protein interactions with ezrin in MDA-MB-231 cells. Endogenous co-immunoprecipitation was used to validate protein-protein interactions between ezrin and p65 in MDA-MB-231. Exogenous interactions between ezrin and p65 were validated in MDA-MB-231 cells via Flag-ezrin and HA-p65 co-transfection and followed by co-immunoprecipitation. Immunofluorescence staining was used to visualize ezrin and p65 co-localization in MDA-MB-231. LCMS results showed that there were 1000 proteins interacting with ezrin in MDA-MB-231 cells. Ezrin and p65 interactions were confirmed with both endogenous and exogenous methods. We were also able to visualize ezrin and p65 co-localization in MDA-MB-231. In summary, we found protein-protein interactions between Ezrin and p65 in human breast cancer cells.

Homology-based cloning and expression analysis of Rf genes encoding PPR-containing proteins in tobacco

As a model plant, mechanisms of the cytoplasmic male sterility/restoration of fertility (CMS/Rf) system in tobacco are seldom studied. Using Rf gene sequences from other Solanaceae plants and the draft genome of Nicotiana benthamiana, degenerate primers were designed to amplify the cDNA pool of N. tomentosiformis. In total, six possible Rf sequences were identified, two of which contained base-deletion mutations. The other four were intact open reading frames, of which NtomPPR5 harbored a 3-pentatricopeptide repeat (PPR) motif deletion. Structure analysis revealed that they all encoded a PPR-containing protein with putative mitochondrial targeting signals at their N-terminus, and they all belong to the P subfamily. Phylogenetic analysis showed that all of the Rf-coding PPRs clustered together, and recent duplication events might have occurred in tobacco after the divergence of the species. Quantitative reverse transcription polymerase chain reaction analysis demonstrated that the NtomRfs were expressed in all tissues of N. tomentosiformis and (CMS) K326, although the expression levels varied with gene, organ, and developmental stage. Furthermore, the expression levels of Rf sequences in K326 were lower than those in CMS K326. The molecular basis of the CMS/Rf system in tobacco requires further investigation.

Genomic instability in phenotypically normal regenerants of medicinal plant Codonopsis lanceolata Benth. et Hook. f., as revealed by ISSR and RAPD markers

Codonopsis lanceolata Benth. et Hook. f., commonly known as bonnet bellflower, is a high-valued herb medicine and vegetable. In this study, a large number of plants were regenerated via organogenesis from immature seed-derived calli in C. lanceolata by a simple and efficient method. Compared with the mother donor plant, the regenerated plants did not exhibit visible phenotypic variations in six major morphological traits examined at the stage of one-season-maturity under field conditions. To gain insight into the genomic stability of these regenerated plants, 63 individuals were randomly tagged among a population of more than 2,000 regenerants, and were compared with the single mother donor plant by two molecular markers, the inter-simple sequence repeats (ISSR) and randomly amplified polymorphic DNA (RAPD). Apparent genomic variation was detected in the 63 regenerants, whereas preexisting heterozygosiy in the donor plant was deemed minimal by testing 30 seedlings germinated from selfed seeds of the same donor plant. The percentages of polymorphic bands (PPB) in the ISSR and RAPD analysis were respectively 15.7 and 24.9% for the 63 regenerated plants. Cluster analysis indicates that the genetic similarity values calculated on the basis of RAPD and ISSR data among the 64 plants (63 regenerated and one donor) were respectively 0.894 and 0.933, which allow classification of the plants into distinct groups. Nineteen randomly isolated bands underlying the changed RAPD or ISSR patterns were sequenced, and three of them showed significant homology to known-function genes. Detailed pairwise sequence comparison at one locus between the donor plant and a regenerant revealed that insertion of two short (24 and 19 bp) stretches of nucleotides in the regenerated plant relative to the donor plant occurred in an apparently stochastic manner.

String vibration dampers do not reduce racket frame vibration transfer to the forearm

In this study, we examined the effect of string vibration damping devices on reducing racket frame vibration transfer to the forearm. Twenty participants volunteered to hold a tennis racket stationary in a forehand and backhand stroking position while tennis balls were fired at 20 m x s(-1) towards two impact locations, the node of vibration and the dead spot. A three-way analysis of variance with repeated measures on damping condition, impact location and stroke condition was performed on the data. The resonant frequency of the hand-held racket was found to be approximately 120 Hz. No significant differences in amplitude of vibration at the resonant frequency were found for the wrist or the elbow when damped and non-damped impacts were compared. Impacts at the dead spot produced greater amplitudes of vibration (P < 0.01) but no interaction between impact location and string dampers was evident. The string dampers had no effect on the grip force used or the muscle electrical activity in the forearm after impact. In conclusion, we found that string dampers do not reduce the amount of racket frame vibration received at the forearm. We suggest that string dampers remain a popular accessory among tennis players because of their acoustic effects and psychological support rather than any mechanical advantage.

Global gene profiling analysis of mouse uterus during the oestrous cycle

Many genes related to the cyclic changes of the uterus during the oestrous cycle have been identified using a one-by-one approach. In the present study, cDNA microarray technology was applied to investigate the global profile of gene expression of mouse uterus at the oestrous and dioestrous stages. At a certain stage of the oestrous cycle, the uteri of mature CD-1 mice (n=10) were removed, pooled and snap-frozen in liquid nitrogen. Total RNA was extracted to synthesize cDNA probes for microarray assay. By screening 8192 mouse genes and expressed sequence tags (ESTs), 51 upregulated and 51 downregulated genes were identified in oestrous uterus, of which 62 are well characterized and 40 are ESTs. The known genes were assigned to various gene categories according to their main function. The microarray was performed three times with three independent sets of uterine tissue pools. The results of northern blot analysis for small proline-rich protein 2 (Sprr2), 17beta-hydroxysteroid dehydrogenase type 2 (17betaHSD-2), high mobility group 2 (Hmg2), mitotic checkpoint component 2 (Mad2) and an EST AW555366 mRNA were consistent with that of microarray analysis. In situ hybridization was performed to localize the transcript of the EST AW555366. Most of the upregulated genes encode secreted immune-related proteins, proteinases and their inhibitors, indicating their potential involvement in sperm viability as well as capacitation. The downregulated genes mainly encode cell cycle-related factors, implying the active proliferation of uterus at dioestrus.

Prevalence of thyroid diseases in Nevada counties with respect to perchlorate in drinking water

Perchlorate is well-known to inhibit the uptake of iodine by the thyroid and has been shown to do so at doses in the milligrams-per-day range and higher. Perchlorate has been found in the water supply of Clark County (Las Vegas), Nevada, at 4 to 24 micrograms/L (parts per billion) and may provide exposure dosages in the tens of micrograms per day. An analysis of the Medicaid database from Nevada was undertaken to determine whether an increase in the prevalence of any thyroid disease was associated with that level of perchlorate content. The prevalence of persons being seen for thyroid disease or for specific thyroid diseases (goiter, nodule, thyrotoxicosis, congenital hypothyroidism, acquired hypothyroidism, thyroiditis, and other thyroid disorders) and for thyroid cancer among the Medicaid-eligible population of each county was calculated for the 2-year period 1997 to 1998. The prevalences in Clark County were compared with those in Washoe County (i.e., Reno), the second most populous county in the state, and with those for the rest of the state. There was no evidence of an increased rate of thyroid disease (or of any specific thyroid disease) associated with perchlorate exposure. Generally, the prevalences in the metropolitan parts of the state were lower than for the rest of the state, particularly for acquired hypothyroidism. This analysis found no evidence that perchlorate-containing drinking water at the given level increased the prevalence of acquired hypothyroidism or of any other thyroid condition.

Use of 'chalk' in rock climbing: sine qua non or myth?

Magnesium carbonate, or 'chalk', is used by rock climbers to dry their hands to increase the coefficient of friction, thereby improving the grip of the holds. To date, no scientific research supports this practice; indeed, some evidence suggests that magnesium carbonate could decrease the coefficient of friction. Fifteen participants were asked to apply a force with the tip of their fingers to hold a flattened rock (normal force), while a tangential force pulled the rock away. The coefficient of friction--that is, the ratio between the tangential force (pulling the rock) and the normal force (applied by the participants)--was calculated. Coating (chalk vs no chalk), dampness (water vs no water) and rock (sandstone, granite and slate) were manipulated. The results showed that chalk decreased the coefficient of friction. Sandstone was found to be less slippery than granite and slate. Finally, water had no significant effect on the coefficient of friction. The counter-intuitive effect of chalk appears to be caused by two independent factors. First, magnesium carbonate dries the skin, decreasing its compliance and hence reducing the coefficient of friction. Secondly, magnesium carbonate creates a slippery granular layer. We conclude that, to improve the coefficient of friction in rock climbing, an effort should be made to remove all particles of chalk; alternative methods for drying the fingers are preferable.

Estimating the minimum grip force required when grasping objects under impulsive loading conditions

As an aid to studying the efficiency of grip force scaling in the context of collisions, we present a simple cost-effective approach to estimating the slip ratio--that is, the minimum grip-to-load-force ratio needed to prevent object slippage. The grip apparatus comprises a sturdy load cell to measure grip force and two linear potentiometers to provide detailed description of finger movements. The slip ratio was estimated by plotting the magnitude of finger movement against the grip-to-load-force ratio at the time of impact. The slip ratio was dependent on the direction of loading, which stresses the importance of estimating slip ratios in a context similar to that of the experiment in which the efficiency of subjects' behavior is to be assessed.

Neonatal thyroid-stimulating hormone level and perchlorate in drinking water

BACKGROUND

The effect of perchlorate in drinking water on neonatal blood thyroid-stimulating hormone (thyrotropin; TSH) levels was examined for Las Vegas and Reno, Nevada.

METHODS

The neonatal blood TSH levels in Las Vegas (with up to 15 microg/L (ppb) perchlorate in drinking water) and in Reno (with no perchlorate detected in the drinking water) from December 1998 to October 1999 were analyzed and compared. The study samples were from newborns in their first month of life (excluding the first day of life) with birth weights of 2, 500-4,500 g. A multivariate analysis of logarithmically transformed TSH levels was used to compare the mean TSH levels between Las Vegas and Reno newborns, with age and sex being controlled as potential confounders.

RESULTS

This study of neonatal TSH levels in the first month of life found no effect from living in the areas with environmental perchlorate exposures of </=15 microg/L (P = 0.97).

CONCLUSIONS

This study, which was sensitive enough to detect the effects of age and gender on neonatal blood TSH levels, detected no effect from environmental exposures to perchlorate.

Sex differences and action scaling in overhead reaching

Specifications of affordances is independent of the anthropometric scale of the perceiver. It is therefore predicted that sex differences disappear when perceptual performance is scaled relative to the relevant physical properties of the system formed by performer and environment in a particular action. 24 women and 30 men were compared for their ability to perceive the boundaries for overhead reaching for a ball suspended above them. Perceived and actual maximum action boundaries were measured in two height conditions, with and without wearing 15-cm high blocks under their feet. On average the men reached higher than the women; however, when perceived maximum reachable height was expressed as a ratio of actual maximum reachable height, the difference between the groups disappeared. The participants showed an identical fit between environment and performer in both height conditions. The results indicate that the specification of affordances for overhead reaching is independent of the height and the sex of the performer.

Neonatal thyroxine level and perchlorate in drinking water

Environmental contamination of drinking water has been observed for perchlorate, a chemical able to affect thyroid function. This study examines whether that exposure affected the thyroid function of newborns. Neonatal blood thyroxine (T4) levels for days 1 to 4 of life were compared for newborns from the city of Las Vegas, Nevada, which has perchlorate in its drinking water, and those from the city of Reno, Nevada, which does not (detection limit, 4 micrograms/L [ppb]). This study is based on blood T4 analyses from more than 23,000 newborns in these two cities during the period April 1998 through June 1999. No difference was found in the mean blood T4 levels of the newborns from these two cities. Drinking water perchlorate levels measured monthly for Las Vegas ranged during this study period from non-detectable for 8 months to levels of 9 to 15 ppb for 7 months. Temporal differences in mean T4 level were noted in both cities but were unrelated to the perchlorate exposure. This study was sufficiently sensitive to detect the effects of gender, birth weight, and the day of life on which the blood sample was taken on the neonatal T4 level, but it detected no effect from environmental exposures to perchlorate that ranged up to 15 micrograms/L (ppb).

A role for E2F1 in the induction of ARF, p53, and apoptosis during thymic negative selection

E2F transcriptional activity controls the expression of many of the genes required for G1 to S phase progression. E2F1, one member of the E2F family, plays an important role in the induction of apoptosis. We have examined the role of the E2F1 transcription factor in apoptosis during T-cell maturation in the thymus. We show that E2F1 is required for the apoptosis of autoimmune immature T cells during thymic negative selection in vivo. This T-cell receptor-mediated apoptosis coincides with the E2F1-dependent increase of p19-ARF mRNA and p53 protein levels. In contrast, E2F1 is not required for the induction of apoptosis by glucocorticoids or DNA damage. These results demonstrate a specific role for E2F1, which triggers a pathway leading to ARF and p53 induction, in a physiological apoptosis pathway that is uncoupled from a normal proliferative event.

Grip force dynamics in the approach to a collision

This experiment investigated the prediction of load force (LF) in impulsive collisions inferred from anticipatory adjustments of grip force (GF) used to stabilise a hand-held object. Subjects used a precision grip to hold the object between thumb and index finger of their right hand and used the arm either: (1) to move the object to produce a collision by hitting the lower end of a pendulum, causing it to swing to one of three target angles, or (2) to hold the object still while receiving a collision produced by the experimenter releasing the pendulum from one of three angles. Visual feedback of the pendulum's trajectory was available in the production task only. In all conditions, subjects increased GF in advance of the collision. In receiving the collision without advance information, subjects set GF levels to the mid-range of the experienced forces. When subjects possessed knowledge about the maximum angle of pendulum swing - either because they were going to produce it or because they were verbally informed - magnitude of the anticipatory-GF magnitude response was scaled to the predicted LF magnitude. Furthermore, GF was scaled to LF with a higher gain when producing compared to receiving the collision. This suggests that updating forward models through a semantic route is not as powerful as when the updating is achieved through the more direct route of dynamic exploration.

Thyroid health status of ammonium perchlorate workers: a cross-sectional occupational health study

Since pharmaceutical exposures to perchlorate are known to suppress thyroid function in patients with hyperthyroidism, a study of employees at a perchlorate manufacturing plant was conducted to assess whether occupational exposure to perchlorate suppresses thyroid function. Exposure to perchlorate was assessed by measurement of ambient air concentrations of total and respirable perchlorate particles, and systemic absorption was assessed by measurement of urinary perchlorate excretion. Airborne exposures ranged from 0.004 to 167 mg total particulate perchlorate per day. Urinary perchlorate measurements demonstrated that exposure to the airborne particulate perchlorate resulted in systemic absorption. Workers were grouped into four exposure categories with mean absorbed perchlorate dosages of 1, 4, 11 and 34 mg perchlorate per day. Thyroid function was assessed by measurement of serum thyroid-stimulating hormone, free thyroxine index, thyroxine, triiodothyronine, thyroid hormone binding ratio, thyroid peroxidase antibodies, and by clinical examination. No differences in thyroid-function parameters were found between the four groups of workers across approximately three orders of magnitude of exposure and of dose. Thus human thyroid function was not affected by these levels of absorbed perchlorate. In addition, no clinical evidence of thyroid abnormalities was found in any exposure group. The blood-cell counts were normal in all groups, indicating no evidence of hematotoxicity in this exposure range. The absence of evidence of an effect on thyroid function or blood cells from occupational airborne perchlorate exposure at a mean absorption of 34 mg/day demonstrates a no-observed-adverse-effect-level (NOAEL) that can assist in the evaluation of human health risks from environmental perchlorate contamination.

Expertise and the regulation of gait in the approach phase of the long jump

In the approach phase of the long jump, athletes attempt to strike the take-off board accurately with minimum loss of speed, and in an optimum body position for take-off. Previous research has shown that skilled long jumpers demonstrate an ascending-descending trend of variability rather than a consistent pattern of foot placement over trials. The present study examined whether non-long jumpers showed a similar pattern of variability in footfall placement between trials to skilled long jumpers. Consistency of foot placement over trials for non-long jumpers (n = 11) was determined using a panned video camera. Digitization of the foot position provided toe-board distances during the run-up phase. Our results showed that non-long jumpers have a similar pattern of descending variability near to the take-off board to expert long jumpers, suggesting the use of visual regulation. However, in comparison to more skilled subjects, non-long jumpers accumulated a considerably larger maximum mean standard deviation in footfall placement between trials (58 cm). Since non-long jumpers had no previous task-specific training, these data extend our current understanding of the regulation of goal-directed gait.

[Comparative study of applying tiaoxue yisui recipe and SSL regimen in treating infantile chronic aplastic anemia and analysis of its therapeutical mechanism]

OBJECTIVE

To explore the effective method in treating infantile chronic aplastic anemia (ICAA) by using traditional Chinese medicine (TCM).

METHODS

Seventy-eight cases of ICAA were observed, 48 of them were treated with Tiaoxue Yisui recipe (treated group), 30 cases were treated with SSL regimen (control group).

RESULTS

The remission rate and total effective rate in treated group were 52.08% and 81.25% respectively, they were higher than those in control group (P < 0.05). After one year treatment the ratio of hemopoietic and non-hemopoietic cells in treated group was higher than that in control group (P < 0.05). The number of megakaryocyte in treated group was more than those in control group (P < 0.05).

CONCLUSION

Tiaoxue Yisui recipe could improve the quality of the patient's life. The therapeutical mechanism of the Tiaoxue Yisui recipe might promote the proliferation of hemopoietic stem cells and regulate the immune function.

[Separation and identification of the llungianin A and B from the root of Pimpinella thellungiana Wolff]

Two compounds were isolated from the roots of Pimpinella thellungiana wolff. On the basis of spectral analysis (UV, IR, MS, 1HNMR, 1H-1H COSY, 13CNMR, 1H-13C COSY, DEPT), they were identified as 2-(1-ethoxy-2-hydroxy) propyl-4-methoxyphenol(I); 2-(1-ethoxy-2-hydroxy) propyl-4-methoxyphenyl-2-methyl-butyrate (II). They are new compounds named the llungianin A and B. Pharmacological tests showed that they have some hypotensive effects.

Occlusion rate of ball texture as a source of velocity information

When a ball is rolling on the ground toward an observer, its elements of texture are successively occluded. The number of the elements of texture occluded per unit of time determines the occlusion rate. The aim of this study was to examine the role of the occlusion rate of ball texture and the velocity of the ball in the perception of the time remaining before the arrival. If the occlusion rate is used to perceive the time to arrival, then timing the initiation of movement should depend on occlusion rate. On the other hand, if the optical variable tau is exclusively used, then no variation is expected. 20 subjects were required to avoid balls rolling directly toward them. Three different ball textures and five ball velocities were used, leading to 10 different occlusion rates. The results showed that the timing of the initiation of the movement was not modified by variations of occlusion rate. However, the velocity of the avoidance movement increased with occlusion rate. The role of timing initiation and movement velocity in the control of the action are discussed, and it is suggested that occlusion rate is perceived and taken into account in the control of avoidance movements.