Lack of causal association between epilepsy and dementia: A Mendelian randomization analysis

OBJECTIVE

Epidemiological studies have reported an association between epilepsy and dementia. However, the causal relationship between epilepsy and the risk of dementia is not clear. We aimed to inspect the causal effect of epilepsy on memory loss and dementia.

METHODS

We analyzed summary data of epilepsy, memory loss, and dementia from the genome-wide association study (GWAS) using the two-sample Mendelian randomization (MR) method. We used the estimated odds ratio of memory loss and dementia associated with each of the genetically defined traits to infer evidence for a causal relationship with the following exposures: all epilepsy, focal epilepsy (including focal epilepsy with hippocampal sclerosis, lesion-negative focal epilepsy, and focal epilepsy with other lesions), and genetic generalized epilepsy (including childhood absence epilepsy, generalized tonic-clonic seizures alone, Juvenile absence epilepsy, and Juvenile myoclonic epilepsy).

RESULTS

According to the result of MR using the inverse variance weighted method (IVW), we found that genetically predicted epilepsy did not causally increase the risk of memory loss and dementia (p > 0.05). Results of the MR-Egger and weighted median method were consistent with the IVW method.

CONCLUSIONS

No evidence has been found to support the notion that epilepsy can result in memory loss and dementia. The associations observed in epidemiological studies could be attributed, in part, to confounding or nongenetic determinants.

Quantifying the contributions of natural and anthropogenic dust sources in Shanxi Province, northern China

Dust storms have direct or indirect impacts on climate change and human health. Identifying and quantifying natural/anthropogenic dust sources can facilitate effective prevention and control of dust events. Based on surface real-time PM10 monitoring data, satellite remote sensing and the HYSPLIT model, this study determined the specific timing, coverage and sources of dust events in Shanxi Province, Northern China. Thus, a composite fingerprinting technique was established to quantify potential dust sources and dust contributions of single dust events. The dust oxidation model was validated, indicating that the composite fingerprinting technique was well suited to the study region. The results show that natural dust sources (67%) contributed more to the study region than anthropogenic dust sources. They were mainly from the northwest and north of the study region. Particularly, the contributions of Taiyuan (TY) and Linfen (LF) accounted for the largest (82%) and smallest (55%) proportions, respectively, both exceeding 50%. Anthropogenic dust sources contributed 33%, mainly from the east and south of the study region. The contribution of anthropogenic dust sources increased in the study region from north to south. In terms of potential dust sources, the Tengger Desert and Badain Jaran Desert (TDBD) contributed the most (26%), followed by the Otindag Sandy Land (OL) (22%). The Taklimakan Desert (TD) contributed the least (2%). The Middle Farmland region of the Hexi Corridor (HMF) in the west (15%) had the largest proportion of anthropogenic dust sources. Differences in the regional contribution of potential dust sources mainly resulted from winter winds, surface drought severity and particle size. At an insignificant distance from the study region, the contribution of potential dust sources was larger in the west than in the east and increased from south to north overall. These methods and findings can contribute to improving the ecological environment in Northern China.

[The effect of unexpected follicular development in artificial cycles on the clinical outcomes in frozen thawed embryo transfer based on propensity score matching]

Objective: To study the effect of unexpected follicular development in artificial cycles on the clinical outcomes in frozen thawed embryo transfer based on propensity score matching(PSM). Methods: The retrospective cohort study analyzed the clinical data of 7 064 cycles (5 716 patients) of artificial cycle frozen-thawed embryo transfer (AC-FET) in the Reproduction Center of the Third Affiliated Hospital of Zhengzhou University from January 1, 2016 to December 31, 2020. The clinical data were divided into three groups according to the degree of follicular development in AC-FET: no follicular growth group (group A, 6 349 cycles), small follicular growth group (group B, 248 cycles), and large follicular growth group (group C, 467 cycles). Differences in clinical outcomes between the small follicle growth group (Group B) and the large follicle growth group (Group C) were compared with the no follicle growth group (Group A) after PSM and logistic regression to adjust for confounding factors at baseline. A binary logistic regression model was used to analyze the factors related to the unanticipated follicular development in AC-FET. Results: Age [M(Q1,Q3)] was [31.0 (28.0, 36.0)] years in Group A, [34.5 (30.0, 40.0)] years in Group B, and [36.0 (31.0, 41.0)] years in Group C. After adjusting for confounders, the differences between Groups A and B in clinical pregnancy rate (P=0.169), live birth rate (P=0.318), early abortion rate (P=0.470), and miscarriage rate (P=0.783) were not statistically significant. The differences in clinical pregnancy rate (P=0.743), live birth rate (P=0.486) and miscarriage rate (P=0.080) between Groups A and C were not statistically significant, while early miscarriage rate (P=0.034) differences were statistically significant. The age, BMI, basal AFC, AMH and starting dose of estrogen were correlates of the emergence of non-expected small follicles in Groups B and A. The adjusted OR (AOR) values (95%CI) were 1.03 (1.01-1.06), 0.93 (0.90-0.98), 0.97 (0.95-0.99), 0.96 (0.95-0.97), and 0.59 (0.45-0.77), all P<0.05. Age, basal AFC, AMH and starting dose of estrogen were the associated factors of the appearance of non-expected large follicles in Groups C and A. The AOR values (95%CI) were 1.03 (1.01-1.05), 0.93 (0.91-0.95), 0.96 (0.95-0.97), and 0.52 (0.42-0.64), all P<0.05. Conclusions: In AC-FET, the clinical outcome of small follicular growth is similar to that of unfollicular growth; Compared with the growth without follicles, the growth and development of large follicles can reduce the early abortion rate; Patients with older age, less AFC, lower AMH, and lower initial dose of estrogen could be more likely to have unanticipated follicular development during endometrial preparation.

[Effect of preimplantation genetic testing for aneuploidies on pregnancy outcome in patients with unexplained recurrent spontaneous abortion]

Objective: To investigate the effect of preimplantation genetic testing for aneuploidies (PGT-A) on pregnancy outcome and perinatal outcome of single live birth in patients with unexplained recurrent spontaneous abortion (URSA). Methods: The clinical data of 351 cycles of the first transfer of a blastocyst through whole embryo freezing in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from 2019 to 2021 were retrospectively analyzed. According to whether PGT-A was performed before the transfer, the patients were divided into two groups: the PGT-A group (160 cycles) and the control group (191 cycles) were treated with in vitro fertilization/intracytoplasmic sperm microinjection (IVF/ICSI). To adjust for confounding factors, propensity score matching (PSM) was carried out in a 1∶1 ratio between the two groups of patients. After matching, 98 patients in the PGT-A group and 98 patients in the control group were compared for pregnancy outcome and perinatal outcome of singleton live births. Results: Before PSM, the female age in the PGT-A group was (33.6±4.0) years, lower than that in the control group (34.5±4.5) years (P=0.049). Male age in the PGT-A group was (33.6±4.1) years, lower than that in the control group (35.3±5.1) years (P<0.001). There were statistically significant differences between the two groups in infertility factors, female body mass index (BMI), years of infertility, number of spontaneous abortions, basal follicle stimulating hormone (FSH), endometrial thickness on the day of transfer and the percentage of high-quality blastocysts (all P values<0.05); After PSM, there was a statistically significant difference in fertilization methods and infertility factors between the two groups (P<0.05), while other differences were not statistically significant (all P values>0.05); There were statistically significant differences between the two groups in implant rate [63.3% (62 cycles) vs. 49.0% (48 cycles), P=0.044], clinical pregnancy rate [63.3% (62 cycles) vs. 49.0% (48 cycles), P=0.044], and live birth rate [42.9% (42 cycles) vs. 28.6% (28 cycles), P=0.037]. There was no statistically significant difference in perinatal outcomes between the PGT-A group and the control group in obtaining single birth live births (P>0.05). Conclusion: Compared with conventional IVF/ICSI assisted pregnancy, PGT-A assisted pregnancy significantly improves implantation rate, clinical pregnancy rate, and live birth rate in URSA patients. PGT-A improves the pregnancy outcomes in URSA patients but not perinatal outcomes in patients with singleton live births.

The causal relationship between circulating biomarkersand the risk of bipolar disorder: A two-sample Mendelian randomization study

OBJECTIVE

To identify susceptible biomarkers for the development of bipolar disorder (BD), we conducted a Mendelian Randomization (MR) design to screen circulating proteins for the potential risk of bipolar disorder systematically.

METHODS

We performed a two-sample Mendelian randomization (MR) analysis to estimate the causality of 4782 human circulating proteins on the risk of bipolar disorder. 376 circulating biomarkers were selected in MR estimation (4406 circulating proteins with less than 3 SNPs were excluded) with 5368 European descents. GWAS meta-analysis of the potential role of all-cause bipolar disorder arose from the Psychiatric Genomics Consortium (41,917 cases, 371,549 controls).

RESULTS

After IVW and sensitivity analysis, 4 circulating proteins having causal effects on bipolar disorder were identified. ISG15, as a key player in the innate immune response, decreased the risk of bipolar disorder causally (OR = 0.92, 95% CI = 0.89-0.94, P = 1.46e-09). Furthermore, MLN decreased the risk of bipolar disorder causally (OR = 0.94, 95% CI = 0.91-0.97, P = 1.04e-04). In addition, SFTPC (OR = 0.91, 95% CI = 0.86-0.96, P = 4.47e-04) and VCY (OR = 0.86, 95% CI = 0.77-0.96, P = 8.55e-03) presented a suggestive association with bipolar disorder.

CONCLUSIONS

Our findings indicated that ISG15 and MLN showed evidence of causality in bipolar disorder and provided a promising target for the diagnosis and treatment of diseases.

[Progress in research of etiology of childhood obesity based on interaction between genes and environment]

Childhood obesity is a global public health problem, which can not only endangers children's health, but also might be an important cause of chronic diseases in adulthood. In recent years, with the in-depth development of precision medicine research, more and more research evidences have shown that there are interactions between environmental factors, such as early intrauterine environment, children's diet, physical activity and children's gene factor on the incidence of childhood obesity, which can result in or inhibit the incidence and development of childhood obesity. This paper summarizes the progress in research in this field to reveal the effects and potential mechanisms of genetic factors and environmental factors on the incidence of childhood obesity in order to provide reference for the precise prevention and control of childhood obesity under different genetic backgrounds.

HPV 16 E6 promotes growth and metastasis of esophageal squamous cell carcinoma cells in vitro

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal malignancies worldwide. Increasing evidence suggests that human papillomavirus (HPV) infection may be associated with the etiology of ESCC. However, the precise role of HPV in ESCC remains unclear.

METHODS AND RESULTS

Proliferation and apoptosis of ESCC cells upon infection with HPV16 E6 were detected using CCK-8 assays and Western blot analyses. The migration rate was measured with a wound healing assay, and a Transwell Matrigel invasion assay was used to detect the invasive ability. RT-qPCR was performed to detect the expression of E6AP, p53, and miR-34a. The proliferation rates were significantly higher in HPV16E6-transfected cell groups compared with the negative control groups. Bax protein expression was downregulated in HPV16E6-treated groups compared to the controls. The wound healing and Transwell Matrigel invasion assays indicated that HPV16 E6 infection could increase ESCC cell migration and invasion. Furthermore, E6AP, p53 and miR-34a expression were decreased in HPV16 E6-transfected cell lines.

CONCLUSION

Our results not only provide evidence that HPV16 E6 promotes cell proliferation, migration, and invasion in ESCC, but also suggests a correlation between HPV infection and E6AP, p53 and miR-34a expression. Consequently, HPV16 E6 may play an important role in ESCC development.

Tyrosine Sulphation of CXCR4 Induces the Migration of Fibroblast in OSF

Oral submucous fibrosis (OSF) caused by areca nut chewing is a prevalent fibrotic disease in Asia-Pacific countries. Arecoline-induced migration of fibroblasts (FBs) plays a vital role in the development of OSF. However, the specific molecular mechanisms involved remain unclear. Many studies have shown that tyrosine sulphation of chemokines can influence cell migration. Herein, we demonstrated that arecoline stimulates tyrosine sulphation of the chemokine receptor 4 (CXCR4) through the tyrosylprotein sulphotransferase-1 (TPST-1) to enhance the migration ability of FBs. Moreover, by RNA-Seq analysis, we found that the most significantly altered pathway was the EGFR pathway after the arecoline stimulation for FBs. After the knockdown of arecoline-induced EGFR expression, the tyrosine sulphation of CXCR4 was significantly decreased by the inhibition of TPST-1 induction. Finally, in human OSF specimens, TPST-1 expression was directly correlated with the expression of CXCR4. These data indicate that the arecoline-induced tyrosine sulphation of CXCR4, which is regulated by TPST-1, might be a potential mechanism that contributes to FB migration in OSF.

[Identification of Synthetic Cannabinoid New Psychoactive Substances 4F-MDMB-BUTINACA and MDMB-4en-PINACA]

Abstract

Objective To establish a method that combines a series of techniques including Fourier transform infrared spectrum （FTIR）, gas chromatography-mass spectrometry （GC-MS）, high resolution mass spectrometry and nuclear magnetic resonance spectroscopy （NMR） for identification of unknown substances. Methods The unknown samples （off-white powder and yellow crystal） seized in the actual cases were detected by FTIR, GC-MS （methanol as solvent）, high resolution mass spectrometry （methanol as solvent） and NMR （deuterated methanol as solvent）. Results The mass spectrum characteristic ions m/z of the main components in the samples measured by GC-MS were 219 （base peak）, 363, 307, 304, 275, 145, 131 and 213 （base peak）, 357, 301, 298, 269, 185, 171, 145 and 131, respectively. The accurate mass numbers [M+H]⁺ measured by high resolution mass spectrometry were 364.203 61 and 358.212 34, respectively. The unknown samples were identified as synthetic cannabinoid new psychoactive substances 4F-MDMB-BUTINACA and MDMB-4en-PINACA after data consultation and database retrieval and comparison, combined with infrared analysis and mass spectrometry data analysis, and their structures were confirmed by ¹H-NMR. Conclusion The established multi-technology joint identification method can be used to identify 4F-MDMB-BUTINACA and MDMB-4en-PINACA in unknown samples. This method is fast, convenient, accurate, reliable and practical, and can provide reference for the identification of cases involving such substances in the future.

[The distribution of peripheral anterior synechiae in patients with primary angle-closure glaucoma]

Objective: To describe the distribution and characteristics of peripheral anterior synechiae (PAS) in patients with primary angle-closure glaucoma (PACG). Methods: Retrospective case study. A total of 285 PACG patients (406 eyes) diagnosed in the Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University from January 2017 to August 2019 were included. They were 102 males and 183 females, with a median age of 67 years old (range, 21 to 95 years old). The PAS range was detected by gonioscopy examination, and the frequency distribution of PAS at 12 clock points was counted by clockwise. The PAS distribution at the middle point of PAS with continuous distribution and ≤6 clock points was assessed. Results: In all cases, PAS of the right eye was concentrated at 11:00 to 4:00 regions [range, 62.0% (129/208) to 78.8% (164/208)]. PAS of the left eye was concentrated at 7:00 to 1:00 regions [range, 50.0% (99/198) to 75.8% (150/198)]. When the PAS range of the atrial angle was ≤6 clock regions, it was mainly at 12:00 to 3:00 [range, 58.3% (74/127) to 67.7% (86/127)] in the right eye and at 10:00 to 12:00 [range, 54.8% (68/124) to 66.1% (82/124)] in the left eye. Among 121 cases (242 eyes) with both eyes involved, the PAS region was at 11:00 to 5:00 [range, 52.1% (63/121) to 79.3% (96/121)] in the right eye and at 8:00 to 1:00 [range, 50.4% (61/121) to 76.9% (93/121)] in the left eye. When the PAS range of the atrial angle was ≤6 clock regions, it was mainly at 12:00 to 4:00 [range, 53.2% (41/77) to 71.4% (55/77)] in the right eye and at 10:00 to 12:00 [range, 50.6% (39/77) to 64.9% (50/77)] in the left eye. In all cases, there were 171 cases of right eyes and 175 cases of left eyes with continuous angle PAS. The central PAS clock position of the right eye was mainly at 11:00 to 3:00 [range, 15.2% (26/171) to 24.0% (41/171)], and that of the left eye was mainly at 8:00 to 12:00 [range, 15.4% (27/175) to 20.6% (36/175)]. Among cases with both eyes involved, there were 98 cases of right eyes and 104 cases of left eyes with continuous angle PAS. The clock distribution of the middle position of the right eye angle PAS was concentrated at 11:00 to 3:00 [range, 17.3% (17/98) to 26.5% (26/98)], and that of the left eye was concentrated at 8:00 to 12:00 [range, 13.5% (14/104) to 20.2% (21/104)]. Conclusions: The PAS of PACG patients is mainly located in the upper and nasal sides, and the closer to the temporal side, the smaller the PAS frequency, showing a gradual downward trend. The PAS distribution of binocular angles is of obvious mirror symmetry. (Chin J Ophthalmol, 2021, 57: 666-671).

[Analysis for the breast cancer screening among urban population in Hebei province, 2018-2019]

From 2018 to 2019, 3 453 cases of high-risk population were screened by the Cancer Screening Program in Urban China (CanSPUC) in Hebei Province, with the age of (53.94±8.00). 147 and 686 cases of breast cancer positive and suspicious positive patients were found, with the positive rate and suspicious positive rate of 4.26% and 19.87% respectively. The suspicious positive rate of 45-49 years old age group was the highest (28.32%), and the positive rate of over 70 years old age group was the highest (7.32%). The positive detection rate of mammography combined with ultrasound was 5.16%, which was higher than that of ultrasound alone (2.46%) (χ²=30.28,P<0.001) or mammography alone (3.06%) (χ²=14.56,P<0.001).

[Relationship between both quality and duration of sleep and type 2 diabetes in middle-aged and elderly people in Shanghai]

Objective: To analyze the relationship between both quality and duration of sleep and type 2 diabetes in middle-aged and elderly people in Shanghai. Method: Baseline data was from the '2017 epidemiological survey in Shanghai community residents aged 35 and above on type 2 diabetes'. Restricted cubic splines were used to draw dose-response curves to show the relationship between PSQI score, sleep duration and type 2 diabetes. Logistic regression model was used to analyze the effects of quality and duration of sleep as well as the interaction, on type 2 diabetes. Results: Results showed that the average PSQI score was (4.09±0.10) points, the proportion of poor sleep quality was 12.55% (95%CI: 10.77-14.58) and the average sleep duration was (7.19±0.03) hours. The relationship between PSQI score and diabetes appeared linear, with the relationship between sleep duration and diabetes as U-shaped. After adjusting for confounders, both poor sleep quality (>7 for PSQI score) and short sleep duration (sleep duration <6 hours) significantly increased the risk of type 2 diabetes, with OR=1.17 (95%CI: 1.06-1.30) and 1.20 (95%CI: 1.01-1.41), respectively. From the interaction analysis, data showed that after adjusting for confounders, both sleep duration <6 hours (OR=1.30, 95%CI: 1.12-1.52) and ≥8 hours (OR=1.79, 95%CI: 1.04-3.07) with poor sleep quality would increase the risks on diabetes. Conclusion: Both poor sleep quality and short sleep duration were associated with the risk of diabetes, while long sleep duration was only associated with the risk of diabetes when accompanied by poor quality of sleep.

Identification of the New Psychoactive Substance Dibutylone

Abstract

Objective To establish a method to identify unknown samples based on combined use of gas chromatography-mass spectrometry （GC-MS）, high resolution mass spectrometry （HRMS） and nuclear magnetic resonance spectrum （NMR） technique. Methods The unknown samples were dissolved in methanol solution containing internal standard SKF525A and detected by GC-MS and HRMS. The mixed samples were separated and purified by silica gel column chromatography, and then dissolved in methanol-d4 solution for structural analysis of ¹H nuclear magnetic resonance spectroscopy （¹H NMR）. Results The characteristic fragment ions （m/z） were 86.1 （base peak）, 71.2, 121.1, and 149.0, and the accurate mass number of molecular ion peak was measured by HRMS to be 236.128 89. By combined use of data analysis and database comparison, a new psychoactive substance of the cathinone class, Dibutylone, was detected in the sample, and the sample also contained a small amount of caffeine. The sample was purified, then identified using ¹H NMR, and was further confirmed to be Dibutylone. In addition, the GC-MS retention time and characteristic fragment ions of the main components of the sample were consistent with those of Dibutylone reference material. Conclusion The method established in this study can be used for the identification of Dibutylone in mixed samples.

Interhemispheric functional connectivity for Alzheimer's disease and amnestic mild cognitive impairment based on the triple network model

The purpose of this study was to explore the differences in interhemispheric functional connectivity in patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI) based on a triple network model consisting of the default mode network (DMN), salience network (SN), and executive control network (ECN). The technique of voxel-mirrored homotopic connectivity (VMHC) analysis was applied to explore the aberrant connectivity of all patients. The results showed that: (1) the statistically significant connections of interhemispheric brain regions included DMN-related brain regions (i.e. precuneus, calcarine, fusiform, cuneus, lingual gyrus, temporal inferior gyrus, and hippocampus), SN-related brain regions (i.e. frontoinsular cortex), and ECN-related brain regions (i.e. frontal middle gyrus and frontal inferior); (2) the precuneus and frontal middle gyrus in the AD group exhibited lower VMHC values than those in the aMCI and healthy control (HC) groups, but no significant difference was observed between the aMCI and HC groups; and (3) significant correlations were found between peak VMHC results from the precuneus and Mini Mental State Examination (MMSE) and Montreal Cognitive Scale (MOCA) scores and their factor scores in the AD, aMCI, and AD plus aMCI groups, and between the results from the frontal middle gyrus and MOCA factor scores in the aMCI group. These findings indicated that impaired interhemispheric functional connectivity was observed in AD and could be a sensitive neuroimaging biomarker for AD. More specifically, the DMN was inhibited, while the SN and ECN were excited. VMHC results were correlated with MMSE and MOCA scores, highlighting that VMHC could be a sensitive neuroimaging biomarker for AD and the progression from aMCI to AD.

[The application of pediatric voice handicap index in children with voice disorders]

Objective: To access the influence of voice disorders on children's voice-related quality of life through the parental version of pediatric voice handicap index (pVHI). Methods: From April 2017 to March 2018, a total of 192 children with voice disorders (dysphonic group) and 111 children without voice disorders (control group) were enrolled in this work. Parents of children in both groups were asked for fill out the questionnaire containing the parental version of pVHI and the data of non-normal distribution were analyzed by Mann-Whitney U test. Spearman test was used for correlation analysis. Results: (1)Vocal cord nodule was the most common voice disorder in children, and boys were more susceptible to voice disorder than girls in this study (70.3%(135/192) vs 29.7%(57/192)). (2)The most common voice abuse or misuse habit was "Shouting loudly". (3)In dysphonic group, the scores of function, physiology, emotion and total were higher than those in control group (all P<0.05). (4)In dysphonic group, there was a weak correlation between the parents' overall evaluation of the children's voice status and the three dimensions of the parental version of pVHI (function: r=0.339, physiology: r=0.334, emotion: r=0.208, all P<0.001). Conclusions: Voice disorders can cause a negative impact on children's quality of life. Parental version of pVHI can be used to assess the voice-related quality of life in children with voice disorders.

[Prospective association between early adiposity rebound and adolescent development in girls]

Objective: To determine possible relations between early adiposity rebound and adolescent development. Methods: Prospective children cohort from 2 kindergartens selected through clustering convenience sampling method in Anhui Province was established since Sep. 2010. Participants were classified as Cohort 1 (2010), Cohort 2 (2011) and Cohort 3 (2012) according to the recruiting year. Till Sep. 2015, a toal of 802 girls were included in this study, and received follow-up till primary school. During kindergarten period, physical examination was carried out every 3 months, 8 times in total. In primary school, physical examination was carried out annually; till Sep.2015, the cohort 1, 2, 3 took physical examination for 12, 11, 10 times, respectively. Information on household economic status and child physical activity was acquired through parents questionnaire survey, and breast development were assessed through visual inspection and palpation. Adiposity rebound was determined according to Rolland-Cachera's method for each girl. Differences between early adiposity rebound and normal adiposity rebound groups were compared by using t test and χ(2) test. Multivariate regression analysis was applied to explore the association between early adiposity rebound and breast development. Results: The average age of participants was (8.90±0.87) years old and the BMI was (17.48±2.70) kg/m(2). The average age at adiposity rebound was (6.16±0.90) years old and the BMI was (15.33±1.82) kg/m(2). Premature breast development was found significantly higher in girls in early adiposity rebound group (27.8%, 54/802) than it in normal adiposity rebound group (13.7%) (P<0.001). After current adiposity, age, household economic status, childhood physical activity adjusted, the OR of premature beast development in early adiposity rebound group was 2.41(95%CI: 1.41-4.12). Conclusion: Early adiposity rebound increases the risk of premature puberty in girls.

Salidroside protects PC-12 cells against amyloid β-induced apoptosis by activation of the ERK1/2 and AKT signaling pathways

Alzheimer’s disease (AD) is one of the most frequent diseases in elderly people and causes high mortality. Its incidence is increasing annually and no effective therapeutic treatment currently exists. In the present study, salidroside, a major active ingredient of Rhodiola rosea, was able to protect PC-12 cells from the toxicity and apoptosis induced by AD inducer amyloid (A)β_1--42. Salidroside significantly protected PC-12 cells by inhibiting Aβ_1-42-induced cytotoxicity and mitochondria-mediated endogenous caspase apoptotic pathways. Mechanistic studies demonstrated that salidroside significantly activated the extracellular signal regulated kinase (ERK)1/2 and protein kinase B (AKT) signaling pathways. This observation was further confirmed using the ERK1/2 inhibitor PD98059 and the AKT inhibitor LY294002, which demonstrated that salidroside promoted PC-12 cell survival and proliferation by activating the ERK1/2 and AKT signaling pathways. Salidroside is a therapeutic candidate for the treatment of AD and provides a basis for further drug development.

[Prospective association between childhood abuse experiences and depressive symptoms in adolescence]

Objective: To evaluate the prospective association between childhood abuse experiences and depressive symptoms in adolescence. Methods: Students in grade 3 and 4 from three primary schools were selected, with informed consent, through convenience cluster sampling in Bengbu, Anhui province in May 2013. The students' body height, weight were assessed. Childhood abuse experiences including emotional, physical or sexual abuses, as well as depressive symptoms were reported by children themselves. Data on parental educational background and household economic status were collected through parent questionnaire. A follow up was conducted 4 years later after baseline survey. Depressive symptoms were evaluated by using Children's Depression Inventory at baseline survey, and by using Mood and Feeling Questionnaire at follow-up. Logistic regression model was used to analyze the relationship between childhood abuse experiences and depressive symptoms in adolescence. Results: A total of 1 172 students were included in baseline survey, and a follow-up was conducted for 87.1% of them (n=1 021). Among 1 126 students with complete information on childhood abuse experiences at baseline survey, the reported rates of physical, emotional and sexual abuses were 12.8% (144/1 126), 11.1% (125/1 126) and 10.9% (123/1 126), respectively. The prevalence of depressive symptoms at baseline survey and follow-up was 7.0% (82/1 172) and 12.3% (126/1 021), respectively. After adjusted for baseline depressive symptoms, age at follow-up, sex, the only-child in family, household economic status, divorce of parents and BMI, childhood emotional and physical abuse experiences were significant risk factors for depressive symptoms in mid-adolescence, with the ORs were 1.86 (95%CI: 1.03-3.36, P=0.039) and 2.37 (95%CI: 1.39-4.03, P=0.001), respectively. Conclusion: Childhood physical and emotional abuse might increase the risk of depressive symptoms in adolescence.

[Developmental characteristics of circadian rhythms in hypothalamic-pituitary-adrenal axis during puberty]

Objective: To explore the developmental characteristics of circadian rhythms in hypothalamus-pituitary-adrenal (HPA) axis during puberty. Methods: A total of 1 070 students from Grade 2-3 in 3 primary schools in Ma'anshan city, Anhui province, were selected for physical examination and circadian rhythm of HPA axis checked from 2015 to 2017. Saliva samples were collected at each of the following three time points: immediately upon wakening, 30 minutes after wakening and bedtime, with the index of circadian rhythm of HPA axis calculated, which including cortisol awake response (CAR), cortisol in puberty priming and diurnal cortisol slope (DCS). Testicular volume, palpation and visual inspection of breast development were used to assess the state of purbety development on boys and girls. Information on gender, date of birth, time to fall asleep, wake-up time and weekly physical activity were gathered through questionnaire survey. Non-parametric test was used to compare the differences of baseline, follow-up period and different adolescent developmental processes of each index on circadian rhythm of HPA axis. Results: During the period of follow-up program and comparing with the continuous undeveloped group, CAR and the changes of CAR showed significantly increase, both in the puberty priming group and continuous development group, with statistically significant differences (CAR: Z=8.551, 4.680, respectively; P<0.01; the changes of CAR: Z=4.079, 2.700, respectively, P<0.01). There were no significant differences noticed in CAR and the changes of CAR between puberty priming group or continuous development group. The area under the curve (AUC) of cortisol in puberty priming group was slightly higher than that in the persistent undeveloped group (Z=2.591, P=0.010). Both the changes of daily cortisol slope (DCS) in puberty priming group and continuing developed group decreased significantly, when comparing with those in continuous undeveloped group (Z=-2.450, Z=-2.151; all P<0.05). There was no significant difference noticed in the changes of cortisol in puberty priming and DCS between different puberty development stages (the changes of AUC: χ(2)=2.747, P=0.253; DCS: χ(2)=4.554, P=0.032). Conclusions: The indexes of circadian rhythm of HPA axis were associated with the development of puberty. Both the cortisol awakening response and the total amount of diurnal cortisol secretion showed an increase, along with the puberty development. The change of diurnal cortisol slope declined with the development of puberty.

Long noncoding RNA LINC00313 modulates papillary thyroid cancer tumorigenesis via sponging miR-4429

Mounting evidence indicates that long noncoding RNAs (lncRNAs) play a critical role in tumorigenesis. LncRNA LINC00313 has been found to be up-regulated and associated with poor prognosis in lung cancer. However, the potential role and clinical value of LINC00313 in human papillary thyroid cancer (PTC) remain elusive and therefore require examination. The aim of this study is to investigate the role of LINC00313 in papillary thyroid cancer (PTC). We found its expression was significantly up-regulated in PTC tissues and cell lines and that this up-regulation correlated with poor prognosis. In vitro experiments indicated that down-regulation of LINC00313 inhibited proliferation and the migratory and colony-forming abilities of PTC cells. Moreover, silencing LINC00313 induced cell cycle arrest and apoptosis in the PTC cells. In addition, mechanism studies showed that LINC00313 down-regulates miR-4429 expression, and that miR-4429 over-expression can abrogate the oncogenic role of LINC00313 in PTC cells. In summary, our data revealed that LINC00313 acts as an oncogene in PTC via sponging miR-4429, and this suggests that LINC00313 may be successfully applied as a therapeutic target in PTC.

Post-targeting strategy for ready-to-use targeted nanodelivery post cargo loading

Based on boronate formation, this study reports a post-targeting methodology capable of readily installing versatile targeting modules onto a cargo-loaded nanoplatform in aqueous mediums. This permits the targeted nanodelivery of broad-spectrum therapeutics (drug/gene) in a ready-to-use manner while overcoming the PEGylation-dilemma that frequently occurs in conventional targeting approaches.

[Association between hair cortisol concentration and overweight and obesity in 6-9 years old childhood]

Objective: To determine the possible relations between hair cortisol concentration (HCC) as a biomarker of chronic stress and childhood overweight and obesity. Methods: Children from grade 1 to 3 from 2 primary schools in Bengbu were invited to participate in the study; and those who suffer from mental disorders, endocrine diseases and those who took hormone drugs were excluded. Parental questionnaire was implemented to collect information on physical activity, screen time, sleep duration, sugar-beverage consumption, as well as socio-economic status. Height and weight were examined. Eligible hair samples from 1 263 children (598 boys and 665 girls) were obtained, and the cortisol content was determined. Multivariate logistic regression model analysis was recruited to examine the association between HCC quartiles and overweight and obesity among boys and girls, respectively. Results: HCC in P(50) (P(25)-P(75)) among girls and boys was separately 11.86 (10.57-13.15) and 11.71 (10.54-13.09) µg/kg (Z=-0.886, P=0.376); HCC in P(50) (P(25)-P(75)) among non-overweight, overweight and obesity boys was separately 11.62 (10.45-12.82), 12.24 (10.88-13.55) and 12.30 (10.99-13.53) µg/kg (χ(2)=8.24, P=0.016); HCC in P(50) (P(25)-P(75)) among non-overweight, overweight and obesity girls was separately 11.35 (10.06-12.62), 12.07 (11.04-13.21) and 12.59 (11.12-13.63) µg/kg (χ(2)=36.16, P<0.001). After age, physical activity, screen time, sleep duration, sugared beverages and socio-economic status adjusted, compared with HCC in Q1 level, girls whose HCC in Q2, Q3 Q4 level had higher rates in overweight, with OR (95%CI) at 1.10 (1.04-3.32), 2.59 (1.51-4.45) and 3.16 (1.79-5.57), respectively. Girls with HCC in Q3 and Q4 level had higher rates in obesity, with OR (95%CI) at 2.22 (1.16-4.26) and 5.62 (3.04-10.41). Among boys, highest quartiles in HCC was risk factor for overweight, OR (95%CI) was 2.14 (1.18-3.90). Conclusion: Hair cortisol had a significant relation with overweight and obesity in 6-9 years old childhood especially among girls.

Morphology, Molecular Characteristics, and Demonstration of a Definitive Host for Sarcocystis rommeli from Cattle (Bos taurus) in China

Sarcocysts of Sarcocystis rommeli were found for the first time in 6 of 34 (17.6%) cattle (Bos taurus) in China. With light microscopy, sarcocysts of S. rommeli were up to 1,130 μm long, with a striated, 4-8-μm-thick cyst wall. Using transmission electron microscopy, the villar protrusions (vp) were 4.7-5.2 × 0.2-0.3 μm, and 0.3-0.5 μm apart from each other. The vp contained microtubules extending from the top of the vp to the middle of the ground substance layer (gsl). A BLAST search of the near full-length 18S rRNA and partial mitochondrial cox1 sequences of S. rommeli revealed 98.7% identity and 99.2% identity with sequences of Sarcocystis bovini in GenBank, respectively. Two domestic cats (Felis catus) fed sarcocysts of S. rommeli shed oocysts/sporocysts in their feces with a prepatent period of 14 to 15 days; the partial mitochondrial cox1 sequences of these oocysts/sporocysts shared the high identities, that is, 99.4% and 99.5%, with cox1 sequences of S. rommeli sarcocysts and S. bovini sarcocysts, respectively. This is the first demonstration of a definitive host for S. rommeli.

Prognostic value of miR-141 downregulation in gastric cancer

Previous research has shown that microRNA-141 (miR-141) expression levels are associated with survival in several types of cancer. In the present study, we investigated the clinical significance and prognostic value of miR-141 in gastric cancer. Paired tissue specimens (tumor and adjacent normal mucosa) from 95 patients with gastric cancer were obtained at the Department of General Surgery, Xiangya Hospital, Central South University from March 2009 to February 2014. The levels of miR-141 in cancerous and corresponding non-cancerous tissues were detected by quantitative reverse transcription-polymerase chain reaction. Associations between clinicopathological parameters and miR-141 expression were evaluated using chi-square tests. Overall survival was calculated and survival curves were plotted using the Kaplan-Meier method; differences between groups were compared using log-rank tests. Compared to the matched normal gastric mucosa, gastric cancer tissues had significantly lower miR-141 expression levels (P < 0.001). This decreased miR-141 expression was significantly associated with tumor differentiation (P = 0.044), positive lymph node metastasis (P = 0.010), distant metastasis (P < 0.001), and advanced tumor-node-metastasis (TNM) stage (P < 0.001). Furthermore, a significant relationship was found between miR-141 expression and overall survival (P = 0.012, log-rank test). Cox regression analysis revealed that lymph node metastasis (P = 0.003), distant metastasis (P = 0.001), TNM stage (P < 0.001), and miR- 141 expression (P = 0.007) were independent prognostic factors in patients with gastric cancer. Our data provide evidence that the downregulation of miR-141 may contribute to the aggressive progression and poor prognosis of human gastric cancer.

Genetic analysis of STR markers on chromosome 21 in a Han population from southeast China

Short tandem repeats (STRs) are highly polymorphic sequences and have been extensively used as genetic markers in mapping studies, disease diagnosis, and human identity testing. In this study, 11 STR markers on chromosome 21, including D21S1432, D21S11, D21S1246, D21S1412, D21S1437, D21S1442, D21S2039, D21S1270, D21S1435, D21S1409, and D21S1446, were analyzed in 740 unrelated Han individuals from southeast China. A total of 132 alleles, ranging from 7-21 for each locus, were named according to the guidelines of the International Society for Forensic Haemogenetics. The distributions of allelic frequencies for the 11 STRs and population genetic parameters were determined. All 11 STR markers showed high polymorphism and heterogeneity in the southeast Han population, with polymorphism information content of 0.61-0.87, heterogeneity of 64.5-86.1%, and power of discrimination of 0.835-0.973. Among the 11 STR markers, D21S1412, D21S1270, D21S11, and D21S1442 showed relatively higher heterogeneity. Their combination was relatively informative and was used in a quantitative fluorescence-polymerase chain reaction assay to diagnose Down syndrome (trisomy 21) in a southeast Chinese Han population. The genetic information and population data for these 11 STRs may be used not only in quantitative fluorescence-polymerase chain reaction assays but also in forensic studies and other genetic tests.

Cohn process influences the functional anticoagulant activity of human protein C

Cohn fraction IV (CFIV) is a byproduct of a plasma fractionation process known as the Cohn process. It is an inexpensive source of protein C, retaining about 90% of protein C (PC) in human plasma. We investigated whether PC is affected during the Cohn process and evaluated correlations among coagulant activity, amidolytic activity and PC antigen during the Cohn process. CFIV was redissolved with citrate-buffered saline for 5 h at 4°C, and then centrifuged at 3500 g for 40 min at 4°C. Functional anticoagulant activity was measured with a one-stage coagulation method based on activated partial thromboplastin time. The functional amidolytic activity of PC was determined using chromogenic substrate assay, and measurement of PC antigen was performed by ELISA. In CFIV, anticoagulant activity declined significantly, with a loss of >80%, while amidolytic activity was not significantly altered, compared to PC antigen. Prior to the Cohn process, high-rank correlations were observed in cryosupernatant, with rs = 0.921 for anticoagulant and amidolytic activities (P = 0.009), 0.896 for anticoagulant activity and antigen (P = 0.014) and 0.832 for amidolytic activity and antigen (P = 0.031). After the Cohn process in CFIV, there was also a high correlation between amidolytic activity and antigen (rs = 0.782, P = 0.038). There were no significant correlations between anticoagulant activity and antigen (rs = 0.223, P = 0.653), or anticoagulant and amidolytic activity (rs = 0.236, P = 0.675). We conclude that the Cohn process significantly influences the anticoagulant activity of PC. Compared to the antigen, PC lost greater than 80% of its anticoagulant activity, but retained its amidolytic activity, during the Cohn process.

A LiFSI-LiTFSI binary-salt electrolyte to achieve high capacity and cycle stability for a Li-S battery

LiFSI and LiTFSI are combined to form a binary-salt electrolyte with higher ionic conductivity and lower viscosity for a Li-S battery. A high capacity and stable cycle performance of the sulfur-based composite with high sulfur content are realized in the electrolyte, accompanied simultaneously by the homogeneous lithium deposition on the anode.

A case-control study indicates that the TRIB1 gene is associated with pancreatic cancer

Pancreatic cancer is a malignant neoplasm originating from transformed cells arising in tissues that form the pancreas. To investigate whether the tribbles homolog 1 (Drosophila) gene (TRIB1) is associated with pancreatic cancer in the Chinese Han population, we conducted this case-control study and genotyped 3 single nucleotide polymorphisms (rs2980879, rs2980874, and rs2235108) of the TRIB1 gene in 182 patients and 359 normal controls of Chinese Han origin and analyzed their association. The results showed that the rs2980879 polymorphism was associated with pancreatic cancer [allele: P = 0.023434, genotype: P = 0.03005; odds ratio (OR) and 95% confidence interval (CI) = 0.727788 (0.552664-0.958404)], whereas the rs2980874 polymorphism had no association with pancreatic cancer [allele: P = 0.749885, genotype: P = 0.699533; OR and 95%CI = 1.041981 (0.809196-1.341734)], and the rs2235108 polymorphism was not associated with the disease [allele: P = 0.629475, genotype: P = 0.547534, OR and 95%CI = 1.128290 (0.690829-1.842770)]. Haplotype analyses and linkage disequilibrium tests were also conducted, and the results showed that these 3 loci are not in the same block. In conclusion, our study indicated that the TRIB1 gene is associated with pancreatic cancer. More studies with larger samples are needed in order to support this finding.

Meta-analysis demonstrates lack of an association of microsomal epoxide hydrolase 1 polymorphisms with esophageal cancer risk

Epoxide hydrolases metabolize exogenous chemicals, including carcinogens such as polycyclic aromatic hydrocarbons. The relationship between microsomal epoxide hydrolase 1 (EPHX1) polymorphisms and esophageal cancer risk has been investigated in various ethnic populations, but the results have been contradictory. We investigated the association of EPHX1 Tyr113His and His139Arg polymorphisms with esophageal cancer via a comprehensive meta-analysis. Publications before August 20, 2012 were included. Eight studies concerning Tyr113His polymorphism associated with 1158 esophageal cancer cases and 1868 controls were identified; 7 studies concerning association of His139Arg with 901 esophageal cancer cases and 1615 controls were also included. A random-effect model was applied, irrespective of between-study heterogeneity. Data and study quality were assessed in duplicate. No significant association was found in either the allele or genotype models for Tyr113His or His139Arg polymorphism with risk for esophageal cancer. Lack of association was also identified in stratified analyses by ethnicity. No publication bias was observed. We conclude that current evidence does not demonstrate association of EPHX1 Tyr113His or His139Arg polymorphisms with risk for development of esophageal cancer.

Lack of association between the interleukin 6 gene -174G>C polymorphism and colorectal cancer: evidence from a meta-analysis

Interleukin 6 (IL6) is a pleiotropic cytokine involved in physiological processes and in a variety of human malignancies. It is thus a logical candidate for being a causative factor underlying colorectal cancer (CRC). The association between the IL6 -174G>C polymorphism and CRC has been widely evaluated; yet, there is a lack of agreement between studies on the role of this polymorphism in CRC. We performed a meta-analysis to evaluate this association signal. Articles published before May 10, 2012 were included in the meta-analysis. A total of 11 populations incorporating 6481 cases and 7935 controls were included in our analysis. A random-effect model was applied irrespective of between-study heterogeneity. Data and study quality were assessed in duplicate. Overall, the association of the -174G>C polymorphism with CRC was not significant in an allelic comparison model [odds ratio (OR) = 0.99; 95% confidence interval (95%CI) = 0.90-1.09; P = 0.827], a homozygote model (OR = 0.98; 95%CI = 0.83-1.15; P = 0.805), a dominant model (OR = 0.99; 95%CI = 0.87-1.13; P = 0.906), or a recessive model (OR = 0.97; 95%CI = 0.88-1.08; P = 0.610). Furthermore, the analyses of subgroups created based on common study design, genotyping methods, and ethnicity failed to find a significant association of this polymorphism with CRC. Therefore, our results collectively suggest that the IL6 -174G>C polymorphism might not be a potential candidate for CRC risk.

Development and characterization of 70 novel microsatellite markers for the sea cucumber (Apostichopus japonicus)

The sea cucumber (Apostichopus japonicus) is an important item in Asian cuisine. It is currently produced through aquaculture, especially in China, after being overexploited in the wild in the 1990s. We isolated 70 novel polymorphic microsatellite loci using an enrichment-colony hybridization protocol. All loci were characterized in 48 individuals from a natural population in Rongcheng (Shandong, China) using genomic DNA isolated from muscle tissue. The number of alleles ranged from 2 to 17 (mean 7.0), and the observed and expected heterozygosities varied from 0.0010 to 1.0000 and from 0.2125 to 0.9477, respectively. Thirty-one of the 70 loci exhibited departure from Hardy-Weinberg equilibrium. These microsatellite markers should be useful resources for population genetic studies and for molecular marker-assisted breeding of A. japonicus.

Two novel NPHS1 mutations in a Chinese family with congenital nephrotic syndrome

Congenital nephrotic syndrome of the Finnish type (CNF) is a lethal, autosomal recessive disorder mainly caused by mutations in the NPHS1 gene; it is found at a relatively high frequency in Finns. We investigated the disease-causing mutations in a Chinese family with CNF and developed a prenatal genetic diagnosis for their latest pregnancy. Mutation analysis was made of all exons and exon/intron boundaries of NPHS1 in the fetus, parents and 50 unrelated controls using PCR and direct sequencing. A heterozygous nonsense mutation within exon 20 (c.2783C>A) and a missense mutation within exon 17 (c.2225T>C) in NPHS1 were detected in the proband's father and mother, respectively, but were not found in the fetus or in 50 unrelated controls. Two novel mutations of c.2783C>A and c.2225T>C in NPHS1 were found to be causative in this Chinese CNF family with no known Finnish ancestry. The most recent sibling did not inherit these two mutations and hence was unaffected with CNF. Determining the cumulative number and ethnic distribution of known mutations can help expedite further study of the pathogenesis of CNF.

Magic-sized diamond nanocrystals

The 2D structural transformation of a heavily boron-doped diamond surface has been revealed using scanning tunneling microscopy (STM). We found that at boron densities above the metal-insulator transition the diamond surface is comprised of spatially ordered magic-sized nanocrystals. The development of quantized electron gas inside these nanocrystals is directly confirmed by STM observation of standing electron waves. The experimental comparison of metallic and insulating diamond reveals the existence of the Fermi-sea-induced quantum selection rules for the self-assembly of nanostructures.

Establishment of a cell-based assay to screen insulin-like hypoglycemic drugs

This study sought to establish a cell based assay to screen insulin analogs. Previous studies have proposed that up-regulation of glucose consumption may have the same anti-diabetic effects as insulin. Here, the amount of glucose that disappeared in culture medium after incubation with insulin or drugs was determined and served as an indicator of the glucose consumption of the cells. In order to establish a cellular model to screen insulin analogs, the sensitivities of four cell lines - BALB/c 3T3, HepG2, NIH3T3, and Bel7402 - to insulin were evaluated by detecting glucose consumption after incubation with insulin (0-125 nM) for 24 h. BALB/c 3T3 was more sensitive to insulin than the other three cell lines. Insulin elevated glucose consumption of BALB/c 3T3 in a concentrationand time- manner. Glucose consumption of BALB/c 3T3 increased by 30% after incubation with insulin (30 nM) for 24 h. Insulin increased the proliferation of BALB/c 3T3 at 48 h. A model was established by detecting glucose consumption after treating BALB/c 3T3 with drugs for 24 h. Using the cell-based assay, we screened more than two thousand samples from Traditional Chinese Medicine (TCM). Five extracts exhibiting glucose absorbance in medium were identified, indicating a hit rate of 0.5%. Results suggested that a cell-based assay by detection of glucose consumption in BALB/c 3T3 was suitable for high-throughput screening and was feasible to identify insulin-like hypoglycemic drugs. Five hits were discovered from natural products. Further characterization of these active extracts could help to identify potential anti-diabetic drugs.

Pulsed Laser Syntheses of Layer-Structured WS2 Nanomaterials in Water

We used water as an environmental friendly medium for the synthesis of hexagonal WS2 nanoparticles by the pulsed laser method. The materials collected on substrates were oriented with the 2H-WS2 basal planes parallel to the surface. The use of water, UV lasers, and large WS2 targets prevented the nanoparticles from restructuring into inorganic fullerenes, which were observed in research using hydrocarbon solvents, longer wavelength lasers, and dispersed powder targets. Fairly good dispersion of nanoparticles suggests that large surface areas are available for chemical reactivity.

Experimental Sarcocystis hominis infection in a water buffalo (Bubalus bubalis)

A water buffalo (Bubalus bubalis) was fed 5.0 x 10(5) Sarcocystis hominis sporocysts from a human volunteer who had ingested S. hominis cysts from naturally infected cattle. A necropsy was performed on the buffalo 119 days after inoculation, and a large number of microscopic sarcocysts (approximately 5,000/g) were found in skeletal muscles. Ultrastructurally, the sarcocyst wall from buffalo muscles has upright villar protrusions measuring about 5.6 x 0.8 microm with numerous microtubules that run from the base to the apex. Sarcocysts from this buffalo were infective to 2 human volunteers, confirming their identity as S. hominis. Therefore, we believe that buffaloes can act experimentally as the intermediate host for S. hominis.

Symposium overview: genetic polymorphisms in DNA repair and cancer risk

A symposium, Genetic Polymorphisms in DNA Repair and Cancer Risk, was presented at the 40th Annual Meeting of the Society of Toxicology, held in San Francisco, California, in March 2001. A brief report of the symposium was published (Kaiser, Science 292, 837-838, 2001). Molecular epidemiological studies have shown that polymorphic variants of genes involved in the metabolism and repair of carcinogens can act as cancer susceptibility genes. These variants of drug metabolic and DNA-repair enzymes either increase the activation of chemical carcinogens or decrease the cells' ability to detoxify/repair mutagenic damages. Although on an individual basis these variant alleles may only slightly change catalytic activity and increase cancer risk, their polymorphic frequency in the human population may contribute to a high proportion of cancer cases. Studies conducted over the past few years have identified variant alleles for a number of DNA-repair genes, some of which have been shown to change DNA-repair capacity. Identifying these genotypic alterations in DNA-repair enzymes and their association with cancer may help to elucidate the mechanisms of cancer etiology and to predict both disease risk and response to cancer therapy, since most antineoplastic treatments mediate their effects through DNA damage.

Amino acid substitution variants of APE1 and XRCC1 genes associated with ionizing radiation sensitivity

Although several variants of DNA repair genes have been identified, their functional significance has not been determined. Using samples collected from 135 cancer-free women, this study evaluated whether amino acid substitution variants of DNA repair genes contribute to ionizing radiation (IR) susceptibility as measured by prolonged cell cycle G2 delay. PCR-restriction fragment length polymorphism (RFLP) assays were used to determine four genotypes: X-ray repair cross complementing group 1 (XRCC1, exon 6, C/T, 194 Arg/Trp and exon 10, G/A, 399 Arg/Gln), XRCC group 3 (XRCC3, exon 7, C/T, 241 Thr/Met) and apurinic/apyrimidinic endonuclease 1 (APE1, exon 5, T/G, 148 Asp/Glu). Fluorescence-activated cell sorter (FACS) analysis was used to measure cell cycle delay. APE1 (exon 5) genotype was significantly associated with mitotic delay (P = 0.01), with the Glu/Glu genotype having prolonged delay compared with the other two genotypes. The mitotic delay index (mean +/- SD) in women with the APE1 codon 148 Asp/Asp, Asp/Glu and Glu/Glu genotypes was 30.95 +/- 10.15 (n = 49), 30.65 +/- 10.4 (n = 60) and 39.56 +/- 13.12 (n = 21), respectively. There was a significant interaction between family history (FH) and APE1 (exon 5) genotype (P = 0.007) as well as FH and XRCC1 (exon 10) genotype (P = 0.005) in mitotic delay. Lastly, prolonged cell cycle delay was significantly associated with number of variant alleles when APE1 Asp148Glu and XRCC1 Arg399Gln genotypes were evaluated in a four-level model (chi(2) for linear trend = 10.9; P = 0.001). These results suggest that amino acid substitution variants of XRCC1 and APE1 may contribute to IR hypersensitivity.

Statistical dynamical direct methods. II. The three-phase structure invariant

The triplet distribution used for kinematical diffraction is extended to the complex case appropriate for dynamical transmission electron diffraction. It is demonstrated that this gives good results if the distributions are handled statistically rather than relying upon single triplet relationships. As a consequence, conventional statistical direct methods will yield a reasonable approximation to the effective dynamical potential for thicknesses when kinematical theory is not appropriate. The recovered effective dynamical potential may be similar to the kinematical potential, but does not have to be and in general will not be.

Alpha-tocopherol dietary supplement decreases titers of antibody against 5-hydroxymethyl-2'-deoxyuridine (HMdU)

This study evaluated the effects of vitamin E (alpha-tocopherol) on oxidative DNA damage in a randomized double-blind Phase II chemoprevention trial. Oxidative DNA damage was measured by the level of auto-antibody (Ab) against 5-hydroxymethyl-2'-deoxyuridine (HMdU) in plasma. After the baseline screening, eligible subjects (n = 31; plasma samples from 28 subjects were available for this study) were randomized to receive 15, 60, or 200 mg of alpha-tocopherol per day for 28 days. Biomarkers were measured twice at baseline--on day 1 (visit 1) and day 3 (visit 2)--and twice after intervention--on day 17 (visit 3) and day 31 (visit 4). At baseline, there was a highly significant inverse correlation between anti-HMdU Ab titer and plasma vitamin E level (r = -0.53; P = 0.004; n = 28). Smoking did not affect baseline anti-HMdU Ab titer; however, anti-HMdU Ab titer levels at baseline were significantly lower in subjects with above-median (0.75 ounce/day) alcohol consumption (P = 0.008). No significant change in anti-HMdU Ab level occurred at either visit 3 or visit 4 for subjects on the lowest dose, 15 mg alpha-tocopherol per day. Subjects receiving 60 mg of alpha-tocopherol per day had a significant decrease in anti-HMdU Ab level at visits 3 and 4 compared with baseline (P = 0.049 and P = 0.02, respectively). However, subjects receiving the highest dose, 200 mg/day, had less consistent results: a significant decrease in anti-HMdU Ab level was seen at visit 4 (P = 0.04) but not at visit 3. Our results demonstrate an inverse relationship between alpha-tocopherol and anti-HMdU Abs in plasma; oxidative DNA damage can be modulated by short-term dietary supplementation of alpha-tocopherol in some subjects.

Transmission of HIV to the placenta, fetus and mother and implications of gametic infection

Therapeutic interventions and public education are reducing pediatric AIDS cases in developed countries, but the number of HIV-infected women and children is still a major global concern. The finding that human sperm-associated HIV can be transmitted to oocytes following in vitro fertilization provides a novel viewpoint from which to consider not only the problem of HIV transmission to children but also transmission to women. In the present paper we will first discuss some recent findings that offer new perspectives on the role of the placenta, and particularly the trophoblast, in maternal-fetal transmission of HIV. Results will be presented showing that cell-mediated infection of syncytiotrophoblast cells requires direct contact between infected lymphocytes and trophoblast. We will also discuss possible routes of transmission of HIV to both mothers and their offspring in the light of data providing evidence of gametic infection. These hypothetical routes include trophoblast-mediated infection of maternal uterine cells during implantation and trophoblast-mediated infection of maternal blood cells during pregnancy. Clearly, more studies are needed in order to assess the significance and relative contribution of these routes in the transmission of HIV.

Collagen gel overlay induces apoptosis of polarized cells in cultures: disoriented cell death

In this study, we attempted to investigate the response of polarized cells to inappropriate interaction with the extracellular matrix. Cell lines of epithelial [Madin-Darby canine kidney (MDCK) and LLC-PK1], endothelial [bovine aortic endothelial cells (BAEC)], and mesenchymal (ESK-4 and NIH/3T3) origins were employed. With collagen gel overlay, MDCK cells underwent membrane remodeling and gradually developed lumen formation within 24 h. Apoptosis could also be observed following cell remodeling. The ratio of apoptosis was enhanced from 12.1 +/- 2.4% within 24 h to 58.4 +/- 9.8% at day 3, and finally the monolayer was disintegrated. Collagen gel overlay-induced apoptosis was not a result of physical stress, since agarose gel overlay did not induce any morphological alterations. All epithelial and endothelial cells examined developed apoptosis in response to collagen overlay. In contrast, collagen overlay did not affect growth of fibroblasts at all, although their growth under agarose gel was slightly hindered due to physical stress. Collagen overlay-induced apoptosis seems to be a unique phenomenon for polarized cells and thus is defined as "disoriented cell death." Furthermore, anti-alpha2-integrin antibody could abolish collagen overlay-induced morphological changes and apoptosis in MDCK cells, indicating that signals through alpha2-integrin on the apical membrane are required for disoriented cell death. Finally, Bcl-2 overexpression prolonged survival of MDCK cells in response to collagen overlay, but these cells eventually developed apoptosis due to downregulation of Bcl-2 protein. These findings indicate that inappropriate cell-matrix interaction results in apoptosis, which may account for cell death mechanisms during developmental processes or under pathological conditions.

Differential expression of cytochrome P4502E1 (CYP2E1) in Morris hepatomas and livers of tumor bearing rats

The objective of this investigation was to determine if the decrease of cytochrome P4502E1 (CYP2E1) in hepatomas is related to the tumor growth rate. There was a significant correlation between N-nitrosodimethylamine (NDMA) demethylase activities and CYP2E1 protein levels in rat liver and hepatomas. The levels of NDMA demethylase activities and CYP2E1 protein content were lower in hepatomas than in the corresponding host livers. NDMA demethylase activities and CYP2E1 protein levels were greater in hepatomas of slow and intermediate growth rate than in fast growing hepatomas. A similar trend was also observed with CYP2E1 mRNA levels. The results demonstrated an inverse relationship between growth rate of rat hepatomas and the expression of CYP2E1.

Poly(ADP-ribose) polymerase in human breast cancer: a case-control analysis

The importance of a genetic polymorphism (A/B allele) of poly(ADP-ribose) polymerase (PARP) pseudogene on chromosome 13q34-qter, and PARP enzyme activities in the development of human breast cancer were evaluated in a cancer case-control study. A total of 309 Caucasian women (> or = 50 years old) were evaluated for the PARP genotype, 70 of whom had histologically confirmed breast cancer, 128 women with benign breast diseases as study controls, and 111 reference controls. Age was significantly associated with case-control status (p < 0.0001), but family history of breast cancer, age at menarche, age at first live birth and parity were not. The frequency of the PARP B allele was similar in breast cancer cases (0.14), study controls (0.13), and reference controls (0.15). In a subset of 14 breast cancer cases and 32 study controls, the mean PARP enzyme activities (induced by H2O2 or oligonucleotide) were observed to be lower in cancer cases; an age-adjusted odds ratio of 3.40 (95% confidence interval = 0.70-19.54) for the below-median oligonucleotide-induced PARP was suggestive of an association. In subjects with the AB or BB genotype, the mean H2O2-induced PARP enzyme activity was significantly higher (p = 0.02, adjusted for case-control status and age) compared with that in subjects with the AA genotype. These findings indicate that: (a) the genetic polymorphism of the PARP pseudogene on chromosome 13 is not associated with the development of breast cancer in our study population; (b) oligonucleotide-induced PARP activity may be useful for identifying postmenopausal women at increased risk for breast cancer; and (c) there is a possible functional link between the genotype of the PARP pseudogene and enzyme activation.

Protective effects of diallyl sulfide on acetaminophen-induced toxicities

Diallyl sulfide (DAS), a major flavour component of garlic, is known to modulate drug metabolism and may protect animals from chemically induced toxicity and carcinogenesis. In this study the effects of DAS on the oxidative metabolism and hepatotoxicity induced by acetaminophen (APAP) in rats were investigated. In the hepatotoxicity evaluation of Fischer 344 rats there was a dose-dependent increase in the odds of mortality rate by APAP (P = 0.009); DAS treatment significantly protected rats from APAP-related mortality (P = 0.026). Liver toxicity determined by lactate dehydrogenase activity was significantly increased by APAP treatment (0.75 g/kg). Pretreatment with DAS protected animals from APAP-induced liver toxicity in a time- and dose-dependent fashion. Treatment of DAS (50 mg/kg) 3 hr after APAP dosing significantly (P < 0.05) protected rats from APAP-induced liver toxicity. The metabolism of APAP (50 microM) in vitro was significantly inhibited by DAS (0.3-1 mM) in liver microsomes isolated from F344 rats. As the effect of DAS on APAP-induced hepatotoxicity in vivo was observed only when DAS was administered before or shortly after (< 3 hr) APAP dosing, data suggested that the protective effect of DAS is mainly at the metabolic activation step of APAP. However, the possibility that DAS may also have effects on other drug metabolism systems, such as glutathione (GSH) and glutathione S-transferases, cannot be ruled out.

Effects of dietary supplementation of alpha-tocopherol on plasma glutathione and DNA repair activities

In a randomized double-blind trial of alpha-tocopherol (vitamin E), we investigated the effects of alpha-tocopherol supplementation on lipid- and water-soluble antioxidants in plasma and DNA repair activities in peripheral mononuclear leukocytes. Baseline levels of antioxidants and DNA repair activities were assessed twice before alpha-tocopherol intervention: on day 1 (visit 1) and day 3 (visit 2). During the second visit, participants were randomized to receive one of three dosages of alpha-tocopherol, 15, 60, or 200 mg/day for 4 weeks. The same biochemical measurements as at baseline were repeated twice after intervention: on day 17 (visit 3) and day 31 (visit 4). A total of 31 healthy volunteers were eligible for the study, completed all four visits and were included in the final data analysis. At baseline, no appreciable differences of dietary intake of vitamin E and plasma alpha-tocopherol were observed among the three dosage groups. In general, supplementation of alpha-tocopherol for 2-4 weeks resulted in a dose-dependent increase of plasma level of alpha-tocopherol (compared to baseline); significant increases of plasma alpha-tocopherol at visits 3 and 4 were observed in the two higher dosage groups, 60 and 200 mg, but not in the lowest dosage group, 15 mg. At visit 4 (but not visit 3), plasma glutathione levels were significantly elevated (compared to baseline) in the two higher dosage groups, 60 and 200 mg, but not in the lowest dosage group, 15 mg. In addition, there was an increase in the lipid protection ratio by supplementation of alpha-tocopherol for 2-4 weeks in the two higher dosage groups, 60 and 200 mg, but not in the lowest dosage group, 15 mg. In general, there were no consistent effects of alpha-tocopherol on DNA repair activities in peripheral mononuclear leukocytes after being adjusted for baseline DNA repair activities. Results from this study demonstrate the interrelationship between alpha-tocopherol and other antioxidants in plasma; total plasma antioxidants can be modulated by short-term dietary supplementation of alpha-tocopherol.