ABSCISIC ACID-INSENSITIVE 5-KIP-RELATED PROTEIN 1-SHOOT MERISTEMLESS modulates reproductive development of Arabidopsis

Soil (or plant) water deficit accelerates plant reproduction. However, the underpinning molecular mechanisms remain unknown. By modulating cell division/number, ABSCISIC ACID-INSENSITIVE 5 (ABI5), a key bZIP (basic (region) leucine zippers) transcription factor, regulates both seed development and abiotic stress responses. The KRP (KIP-RELATED PROTEIN) cyclin-dependent kinases (CDKs) play an essential role in controlling cell division, and SHOOT MERISTEMLESS (STM) plays a key role in the specification of flower meristem identity. Here, our findings show that abscisic acid (ABA) signaling and/or metabolism in adjust reproductive outputs (such as rosette leaf number and open flower number) under water-deficient conditions in Arabidopsis (Arabidopsis thaliana) plants. Reproductive outputs increased under water-sufficient conditions but decreased under water-deficient conditions in the ABA signaling/metabolism mutants abscisic acid2-1 (aba2-1), aba2-11, abscisic acid insensitive3-1 (abi3-1), abi4-1, abi5-7, and abi5-8. Further, under water-deficient conditions, ABA induced-ABI5 directly bound to the promoter of KRP1, which encodes a CDK that plays an essential role in controlling cell division, and this binding subsequently activated KRP1 expression. In turn, KRP1 physically interacted with SHOOT MERISTEMLESS (STM), which functions in the specification of flower meristem identity, promoting STM degradation. We further demonstrate that reproductive outputs are adjusted by the ABI5-KRP1-STM molecular module under water-deficient conditions. Together, our findings reveal the molecular mechanism by which ABA signaling and/or metabolism regulate reproductive development under water-deficient conditions. These findings provide insights that may help guide crop yield improvement under water deficiency.

Glucose status within dark-grown etiolated cotyledons determines seedling de-etiolation upon light irradiation

Exposure of dark-grown etiolated seedlings to light triggers the transition from skotomorphogenesis/etiolation to photomorphogenesis/de-etiolation. In the life cycle of plants, de-etiolation is essential for seedling development and plant survival. The mobilization of soluble sugars (glucose [Glc], sucrose, and fructose) derived from stored carbohydrates and lipids to target organs, including cotyledons, hypocotyls, and radicles, underpins de-etiolation. Therefore, dynamic carbohydrate biochemistry is a key feature of this phase transition. However, the molecular mechanisms coordinating carbohydrate status with the cellular machinery orchestrating de-etiolation remain largely opaque. Here, we show that the Glc sensor HEXOKINASE 1 (HXK1) interacts with GROWTH REGULATOR FACTOR5 (GRF5), a transcriptional activator and key plant growth regulator, in Arabidopsis (Arabidopsis thaliana). Subsequently, GRF5 directly binds to the promoter of phytochrome A (phyA), encoding a far-red light (FR) sensor/cotyledon greening inhibitor. We demonstrate that the status of Glc within dark-grown etiolated cotyledons determines the de-etiolation of seedlings when exposed to light irradiation by the HXK1-GRF5-phyA molecular module. Thus, following seed germination, accumulating Glc within dark-grown etiolated cotyledons stimulates a HXK1-dependent increase of GRF5 and an associated decrease of phyA, triggering the perception, amplification, and relay of HXK1-dependent Glc signaling, thereby facilitating the de-etiolation of seedlings following light irradiation. Our findings, therefore, establish how cotyledon carbohydrate signaling under subterranean darkness is sensed, amplified, and relayed, determining the phase transition from skotomorphogenesis to photomorphogenesis on exposure to light irradiation.

Modular gene analysis reveals distinct molecular signatures for subsets of patients with cutaneous lupus erythematosus

BACKGROUND

Cutaneous lupus erythematosus (CLE) is a heterogeneous autoimmune disease with clinical sequelae such as itching, dyspigmentation and scarring.

OBJECTIVES

We applied a previously described modular analysis approach to assess the molecular heterogeneity of patients with CLE.

METHODS

Whole-blood transcriptomes of RNA sequencing data from a racially and ethnically diverse group of patients with CLE (n = 62) were used to calculate gene co-expression module scores. An unsupervised cluster analysis and k-means clustering based on these module scores were then performed. We used Fisher's exact tests and Kruskal-Wallis tests to compare characteristics between patient clusters.

RESULTS

Six unique clusters of patients with CLE were identified from the cluster analysis. We observed that seven inflammation modules were elevated in two clusters of patients with CLE. Additionally, these clusters were characterized by interferon, neutrophil and cell-death signatures, suggesting that interferon-related proteins, neutrophils and cell-death processes could be driving the inflammatory response in these subgroups. Three different clusters had a predominant T-cell signature, which were supported by lymphocyte counts.

CONCLUSIONS

Our data support a diverse molecular profile in CLE that further adds to the clinical variations of this skin disease, and may affect disease course and treatment selection. Future studies with a larger and diverse cohort of patients with CLE are warranted to confirm these findings.

[The pH-Sensitive Potassium Channel TASK-1 Is a Chemosensor for Central Respiratory Regulation in Rats]

TWIK-related acid-sensitive potassium channel-1 (TASK-1) is a "leak" potassium channel sensitive to extracellular protons. It contributes to setting the resting potential in mammalian neurons. TASK-1 channels are widely expressed in respiratory-related neurons in the central nervous system. Inhibition of TASK-1 by extracellular acidosis can depolarize and increase the excitability of these cells. Here we describe the distribution of TASK-1 in the rat brainstem and show that TASK-1 mRNAs are present in respiratory-related nuclei in the ventrolateral medulla, which have been proposed as neural substrates for central chemo-reception in rats. After inhalation of 8% CO2 for 30 and 60 min, TASK-1 mRNA levels in positive-expression neurons were remarkably upregulated. Injection of the TASK-1 blocker anandamide (AEA) into the rat lateral cerebral ventricle, showed a significant excitement of respiratory at 10 min posttreatment, with a marked decrease in inspiratory and expiratory durations and an increased frequency of respiration. We suggest that TASK-1 channel may serve as a chemosensor for in central respiration and may contribute to pH-sensitive respiratory effects. TASK-1 channel might be an attractive candidate for sensing H^(+)/CO2 in several respiratory-related nuclei in the brainstem. It is likely that TASK-1 participates in pH-sensitive chemical regulation in the respiratory center under physiological and pathological conditions.

[Evaluation of the influenza vaccine effectiveness among children aged 6 to 72 months based on the test-negative case control study design]

Objective: To assess the effectiveness of seasonal influenza vaccine among children aged 6 to 72 months. Methods: The test-negative case control study was conducted based on available surveillance data which was from China Influenza Surveillance Information system (CSIS). From October 2016 to April 2017 and from October 2017 to April 2018,1 161 cases aged 6-72 months with influenza-like illness in Yongkang and Yiwu city, were selected as the study subjects, and the cases with influenza test-positive were selected as the case group (403 cases). Test-negative subjects were selected as control group (758 cases). The etiology and immunization data of the subjects were obtained from CSIS and Immune Information and Management System (IIMS) respectively. Vaccine effectiveness was estimated using multivariate logistic regression model,and the mixed effects of non-randomized control in TNCC study were equalized by using the propensity score (PS) method in the statistical analysis. Results: The age of the subjects was (2.44±1.60) years,and there were 681 boys (58.66%). The age of case group was (2.62±1.58) years, and there were 246 boys (61.04%). The case group was including of 237 cases (58.81%) of influenza A (H3N2), 92 cases (22.83%) of influenza A (H1N1) pmd09, 62 cases (15.38%) of influenza B(Victoria) lineage, 11 cases (2.73%) of influenza B (Yamagata) lineage and one case (0.25%) co-infection of influenza [A(H(3)N(2))+B (Victoria)]. The mean age of the control group was (2.35±1.61) years,and there were 435 boys (57.39%). Overall vaccine effectiveness (VE) against all type influenza for two seasons combined was 58% (95%CI: 31%-74%). An analysis by age groups showed 68% (95%CI:41%-82%) of the VE estimate among children aged 36-72 months while it was 28%(95%CI:-80%-71%)of the VE estimate among children aged 6-35 months. The VE estimate value was 54% (95%CI:16%-75%) against all type influenza and 65% (95%CI:24%-83%) against influenza A (H(3)N(2)) during the 2016-2017 season. During the 2017-2018 season, the VE estimate value was 69% (95%CI:18%-88%) against all type influenza. Conclusion: Influenza vaccine is effective in preventing influenza virus infection during the flu season,especially the effect among children aged 36-72 months is higher compared to that among children aged 6-35 months.

[Correlation between the expression of STOX1 in placenta of patients with early onset preeclampsia]

Objective: To investigate the relationship of STOX1expression and pathogenesis of early onset preeclampsia. Methods: 65 cases of preeclampsia women who delivered in Shanghai Pudong Hospital from October 2015 to June 2018, were recruited, which included 31 cases with early onset preeclampsia (early onset group, gestational week<34 weeks) and 34 patients with late onset preeclampsia (late onset group, gestational week ≥34 weeks). 34 cases women who received caesarean section because of pelvic structural deformities, breech presentation, macrosomia and social factors were included as the control group(gestational week ≥34 weeks) were selected as control group.The expression and localization of STOX1 mRNA and protein in placenta of three groups of maternal were evaluated by immunohistochemistry SP, RT-qPCR and Western blotting. Results: (1) The expression of STOX1 in placenta mainly distributed in the cytoplasm of placental syncytiotrophoblasts, cytotrophoblasts, vascular endothelial and mesenchymal cells, a few in the cell nucleus.The staining intensity of STOX1 in early onset group was significantly stronger than that in late onset group, the staining intensity of the late onset group was similar to that of the control group. The positive expression rates of STOX1protein in early onset group, late onset group and control group were 96.8%(30/31), 70.6%(24/34), 67.6%(23/34) respectively, which was higher in early onset group than that in late onset group(P=0.005). There was no statistical difference of STOX1 level between the late onset group and the control group(P=0.793). (2)Relative expression of STOX1 mRNA in early onset group, late onset group and control group were 0.054 3±0.003 5,0.037 5±0.000 7,0.035 2±0.000 4 respectively, which was significantly higher in early onset group than that in late onset group(P<0.05), while there was no statistical difference between the late onset group and the control group(P>0.05).(3)Relative expression level of STOX1 protein in early onset group, late onset group and control group were 0.78±0.04,0.59±0.020 and 0.54±0.018 respectively, which is higher in early onset group than that in late onset group(P<0.05). There was no statistical difference of STOX1 level between the late onset group and the control group(P>0.05). Conclusions: The pathogenesis of early onset and late onset preeclampsia may be different. Up-regulated expression of STOX1 in placenta may be associated with the pathogenesis of early onset preeclampsia.

[Expression and significance of STOX1 in villi and placenta at different stages of normal gestation]

Objective: To investigate the expression and significance of STOX1 in different stages of gestation villi and placenta. Methods: Totally 137 cases of normal villi and placenta of pregnant women were collected from the Department of Obstetrics of Shanghai Pudong Hospital from October 1(st) 2015 to February 28(th) 2018, including 64 cases of early pregnancy (early pregnancy group) which consists of 32 cases of 5-7(+6) weeks gestation (early pregnancy group A) and 32 cases of 8-11(+3) weeks gestation (early pregnancy group B), 28 cases of 14-26 weeks gestation(middle pregnancy group) and 45 cases of 37-41 weeks gestation (late pregnancy group). The expression and localization of STOX1 mRNA and protein in placenta were evaluated by RT-qPCR, Western blotting and immunohistochemistry. Results: (1)STOX1 was positively expressed in the cytotrophoblasts and syncytiotrophoblasts as well as interstitial and vascular endothelial cells of all groups. (2)STOX1 mRNA expression in each group was significantly different (P<0.05), the lowest was in the early pregnancy group A(0.007 8±0.000 4), which increased along with the progression of gestational age(P<0.05),and reached the highest level in the third trimester(0.064 4±0.001 3). (3)The protein level of STOX1 in different stages of normal pregnancy was 0.53±0.20 in early pregnancy group A;0.62±0.37 in early pregnancy group B;0.70±0.03 in middle pregnancy group and 0.81±0.04 in late pregnancy group respectively; which was positively related with the progression of gestational age (P<0.05). Conclusion: The expressions of STOX1 is gradually increasing along with the normal pregnancy progression, suggesting that it might be involved in proliferation, differentiation and infiltration and (or) apoptosis of trophoblast cells and the development of the placenta.

A meta-analysis to predict the concentration of standardized ileal digestible amino acids in distillers dried grains with solubles for poultry

High variability in amino acid (AA) content and digestibility among sources of distillers dried grains with solubles (DDGS) create challenges for nutritionists when using it in precision nutrition feeding programs. The objective of this meta-analysis was to develop prediction equations for standardized ileal digestible content (SIDC) of AA in DDGS for poultry. A meta-analysis based on 86 observations from 19 publications was conducted to develop equations for predicting SIDC of AA based on chemical composition in DDGS. A mixed model was used to develop prediction equations for SIDC of AA, and a backward selection of variables was conducted based on chemical composition of DDGS. Each total AA content was the best predictor of SIDC for all indispensable AA. The prediction equations for SIDC of Met and Lys were y = -0.12 + 1.05 × Met (R2 = 0.899) and y = -0.22 + 0.91 × Lys (R2 = 0.870), respectively. The prediction equations for SIDC of Met and Lys using data from broiler chick assays were y = -0.16 + 1.12 × Met (R2 = 0.809) and y = -0.24 + 0.90 × Lys (R2 = 0.731), respectively, and equations derived from rooster assay data for Met and Lys were y = -0.05 + 0.97 × Met (R2 = 0.996) and y = -0.20 + 0.97 × Lys (R2 = 0.982), respectively. For all the prediction equations, the intercept (=0) and slope (=1) were not different (P > 0.10) between predicted and observed SID AA values, indicating high accuracy of the models. In conclusion, equations for predicting SIDC of AA in DDGS were developed and showed that total concentration of each AA was the best predictor of SDIC. These prediction equations can be used by animal nutritionists to more accurately estimate SIDC of AA among DDGS sources in diet formulations for precision poultry nutrition feeding programs.

[Screening different HPV genotypes infection and type-specific in cervical exfoliated cells of women in Yili area of Xinjiang Uygur Autonomous Region, China]

Objective: To investigate the infection status and genotype distribution of cervical human papillomavirus (HPV) in women of different ethnic groups and different ages in Yili, Xinjiang Uygur Autonomous Region (Xinjiang). Methods: By using the convenient sampling method, 54 760 women from November 2015 to May 2017 seeking for service in gynecological clinics in a general hospital in Yili, Xinjiang, were selected as the research subjects, and 3 445 samples of cervical mucous exfoliative cells were collected, and the social information of their ethnic and age was collected at the same time. The inclusion criteria were those with sexual life, cervical integrity, and ethnic groups for Han or Uygur or Kazak. PCR-reverse dot blot hybridization was used to detect HPV genotyping in exfoliated cells, and chi-square test was used to compare the difference of HPV positive rate among different ethnic groups. Then, according to ethnicity and age, the differences in positive rates of different ages and ethnic groups were compared in each layer. Results: The positive rate of HPV was 25.6% (882 cases), of which the Han, Uygur and Kazakh were 27.9% (564 cases), 22.9% (196 cases) and 21.6% (122 cases), and the difference was statistically significant (χ(2)=13.80, P=0.001). The most prevalent high-risk genotypes of Han women were HPV16/52/58, accounting for 24.8% (140 cases), 17.7% (100 cases) and 9.8% (55 cases), respectively. The most prevalent high-risk genotypes of Uygur women were HPV16/52/53, accounting for 34.2% (67 cases), 12.8% (25 cases), 9.2% (18 cases), respectively. The most prevalent high-risk genotypes of Kazak were HPV16/52/53, accounting for 37.7% (46 cases), 17.2% (21 cases), 12.3% (15 cases), respectively. The highest rate of HPV in Uygur patients aged ≥61 years was 41.5% (22 cases), and the lowest in group 36-40 years old, 15.9% (21 cases), the difference between different age groups was statistically significant (χ(2)=35.01, P<0.001). Conclusion: The positive rate of HPV infection among Han, Uygur and Kazak in Yili Prefecture of Xinjiang was different, and the HPV positive genotype differs among different ethnic groups.

[Value of modified TI-RADS in the diagnosis of medullary thyroid carcinoma]

Objective: To investigate the value of modified thyroid imaging reporting and data system (TI-RADS) in the sonographic diagnosis of medullary thyroid carcinoma (MTC), and to evaluate the sonographic differences among MTC, papillary thyroid carcinoma (PTC) and benign nodules in order to improve the ultrasound diagnostic accuracy of MTC. Methods: 646 cases of thyroid lesions confirmed by pathology in our hospital were divided into the MTC group (64 cases), PTC group (414 cases) and benign group (168 cases). The ultrasonographic characteristics of these groups were retrospectively analyzed. All of the 646 cases were classified by modified TI-RADS grading criteria. The diagnostic accuracy of MTC and ultrasonic manifestations of MTC, PTC and benign nodular were assessed. Results: The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of modified TI-RADS for MTC were 87.5%, 89.9%, 72.6%, 88.8%, and 67.2%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of modified TI-RADS for PTC were 96.1%, 59.5%, 85.4%, 86.2% and 85.6%. The intraclass correlation coefficient (ICC) of three different physicians for thyroid nodules was 0.983 by the modified TI-RADS. MTC were mostly located in middle and upper parts of the thyroid (85.9%, 55/64), hypoechoic or extremely hypoechoic (89.1%, 57/64), with relatively smooth margin (35.9%, 23/64), aspect ratio<1 (53.1%, 34/64), abundant blood flow (31.2%, 20/64), and high lymph node metastasis rate (51.6%, 33/64). These differences were statistically significant when compared to PTC (P<0.05). Conclusions: Repeatability of modified TI-RADS for MTC was high, and is slightly lower than that for PTC. MTC had specific features: mostly located in middle and upper parts of the thyroid, hypoechoic or extremely hypoechoic, relatively smooth margin, aspect ratio<1, abundant blood flow and high lymph node metastasis rate.

Salinicola tamaricis sp. nov., a heavy-metal-tolerant, endophytic bacterium isolated from the halophyte Tamarix chinensis Lour

A Gram-stain-negative, rod-shaped bacterium, strain F01T, was isolated from leaves of Tamarix chinensis Lour. The isolate grew optimally at 30 °C, at pH 7.0 and with 5.0 % (w/v) NaCl, and showed a high tolerance to manganese, lead, nickel, ferrous ions and copper ions. The major fatty acids were C18 : 1ω7c and C16 : 0, and the predominant respiratory quinone was Q-9. Polar lipids were dominated by diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, unidentified aminoglycolipids and phospholipids. The DNA G+C content was 65.8 %. Based on multilocus phylogenetic analysis, strain F01T belonged to the genus Salinicola, with highest 16S rRNA gene sequence similarity to Salinicola peritrichatus CGMCC 1.12381T (97.7 %). The level of DNA-DNA hybridization between strain F01T and closely related Salinicola strains was well below 70 %. According to the phenotypic, genetic and chemotaxonomic data, strain F01T is considered to represent a novel species in the genus Salinicola, for which the name Salinicola tamaricis sp. nov. is proposed. The type strain is F01T (=CCTCC AB 2015304T=KCTC 42855T).

The antimicrobial peptide sublancin ameliorates necrotic enteritis induced by Clostridium perfringens in broilers

Sublancin is an antimicrobial peptide produced by 168 containing 37 amino acids. The objective of this study was to investigate its inhibitory efficacy against both in vitro and in vivo. In the in vitro study, we determined that sublancin had a minimum inhibitory concentration of 8 μM against , which was much higher than the antibiotic lincomycin (0.281 μM). Scanning electron microscopy showed that sublancin damaged the morphology of . The in vivo study was conducted on broilers for a 28-d period using a completely randomized design. A total of 252 chickens at 1 d of age were randomly assigned to 1 of 6 treatments including an uninfected control; an infected control; 3 infected groups supplemented with sublancin at 2.88, 5.76, or 11.52 mg activity/L of water; and an infected group supplemented with lincomycin at 75 mg activity/L of water (positive control). Necrotic enteritis was induced in the broilers by oral inoculation of on d 15 through 21. Thereafter, the sublancin or lincomycin were administered fresh daily for a period of 7 days. The challenge resulted in a significant decrease in ADG ( < 0.05) and a remarkable deterioration in G:F ( < 0.05) during d 15 to 21 of the experiment. There was a sharp increase of numbers in the cecum ( < 0.05). The addition of sublancin or lincomycin reduced caecal counts ( < 0.05). The counts had a tendency to decrease in the lincomycin treatment ( = 0.051) but were the highest in the sublancin treatment (5.76 mg activity/L of water). A higher villus height to crypt depth ratio in the duodenum and jejunum as well as a higher villus height in the duodenum were observed in broilers treated with sublancin or lincomycin ( < 0.05) compared with infected control broilers. It was observed that sublancin and lincomycin decreased IL-1β, IL-6, and tumor necrosis factor-α levels ( < 0.05) in the ileum compared with the infected control. In conclusion, although sublancin's minimum inhibitory concentration is much higher than lincomycin in vitro, less sublancin is needed to control necrotic enteritis induced by in vivo than lincomycin. These novel findings indicate that sublancin could be used as a potential antimicrobial agent to control necrotic enteritis.

Effects of dietary Lactobacillus plantarum B1 on growth performance, intestinal microbiota, and short chain fatty acid profiles in broiler chickens

Two experiments were conducted to determine the effects of Lactobacillus plantarum B1 on broiler performance, cecal bacteria, and ileal and cecal short chain fatty acids (SCFA). The study also determined whether it was necessary to feed Lactobacillus throughout the entire growth period or if the beneficial effects could be obtained by supplementation during the starter or finisher period only. Experiment 1 was conducted with 72 broilers assigned to 2 treatments (N=6). One treatment was the basal diet (Con), and the other was the basal diet supplemented with 2×10(9) cfu/kg L. plantarum B1 (Wh). In experiment 2, 144 one-day-old broilers were assigned to 4 treatments (N=6) including a basal diet (Con), the basal diet supplemented with 2×10(9) cfu/kgL. plantarum B1 during d one to 21 only (St), the basal diet supplemented with L. plantarum B1 during d 22 to 42 only (Fn), and, finally, the basal diet supplemented with L. plantarum B1 from d one to 42 (Wh). Experiment 1 showed that L. plantarum B1 enhanced broiler average daily gain (ADG) and feed conversion ratio (FCR). In experiment 2, during the starter period, broilers in the Wh and St treatments had higher ADG (P<0.05) than broilers in the Con and Fn, while during the finisher period, broilers in the Wh and Fn had higher ADG (P<0.01) and improved FCR (P<0.01) compared with broilers in the Con and St. On d 42, broilers in the Wh and Fn had decreased E. coli (P<0.05) and increased lactic acid bacteria (P<0.05) in their cecal digesta. L. plantarum B1 also increased (P<0.05) ileal mucosal sIgA as well as ileal and cecal SCFA. However, L. plantarum B1 had no effect on intestinal morphology. In conclusion,L. plantarum B1 plays a positive role in broilers. Supplementation during the finisher period or the entire growth period is superior to supplementation during the starter period only.

Significant concentration changes of chemical components of PM1 in the Yangtze River Delta area of China and the implications for the formation mechanism of heavy haze-fog pollution

Since the winter season of 2013, a number of persistent haze-fog events have occurred in central-eastern China. Continuous measurements of the chemical and physical properties of PM1 at a regional background station in the Yangtze River Delta area of China from 16 Nov. to 18 Dec., 2013 revealed several haze-fog events, among which a heavy haze-fog event occurred between 6 Dec. and 8 Dec. The mean concentration of PM1 was 212μgm(-3) in the heavy haze-fog period, which was about 10 times higher than on clean days and featured a peak mass concentration that reached 298μgm(-3). Organics were the largest contributor to the dramatic rise of PM1 on heavy haze-fog days (average mass concentration of 86μgm(-3)), followed by nitrate (58μgm(-3)), sulfate (35μgm(-3)), ammonium (29μgm(-3)), and chloride (4.0μgm(-3)). Nitrate exhibited the largest increase (~20 factors), associated with a significant increase in NOx. This was mainly attributable to increased coal combustion emissions, relative to motor vehicle emissions, and was caused by short-distance pollutant transport within surrounding areas. Low-volatility oxidized organic aerosols (OA) (LV-OOA) and biomass-burning OA (BBOA) also increased sharply on heavy haze-fog days, exhibiting an enhanced oxidation capacity of the atmosphere and increased emissions from biomass burning. The strengthening of the oxidation capacity during the heavy pollution episode, along with lower solar radiation, was probably due to increased biomass burning, which were important precursors of O3. The prevailing meteorological conditions, including low wind and high relative humidity, and short distance transported gaseous and particulate matter surrounding of the sampling site, coincided with the increased pollutant concentrations mainly from biomass-burning mentioned above to cause the persistent haze-fog event in the YRD area.

[Clinical research of percutaneous vertebroplasty or percutaneous kyphoplasty for treating osteoporotic vertebral compression fractures induced by glucocorticosteroid]

OBJECTIVE

To investigate the clinical characteristics of vertebral compression fracture (VCF) in glucocorticosteroid-induced osteoporosis (GIOP) and risk of vertebral refracture after percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP).

METHODS

In the study, 570 cases who received PVP or PKP as treatments of VCF from January 2010 to December 2013 were retrospective reviewed, of which 42 were GIOP and 21 were followed up as GIOP group, and the other 528 were primary osteoporosis and 391 were followed up, of which 84 were selected as Control group based on age and gender. The fracture location, ratio of single segment fracture and multiple segments fracture in the two groups were compared. In the final follow up, the reoperation rates for vertebral refractures by the Kaplan-Meier method in the two groups were compared.

RESULTS

The follow up periods were (24.0± 13.1) months in GIOP group and (25.8±14.4) months in control group(P>0.05). In GIOP group, there were 11 cases with one-segment fracture, 2 with two-segments fracture, 3 with three-segments fracture, 2 with four-segments fracture, 2 with five-segments fracture and 1 with eight-segments fracture. In Control group, there were 67 cases with one-segment fracture, 12 with two-segments fracture, 3 with three-segment fracture, and 2 with four-segments fracture. The ratio of single segment fracture in GIOP group was significantly lower than that in Control group(52.4% vs. 79.8%,P=0.01). There were 50 fracture segments in GIOP group and 109 fracture segments in Control group. The ratios of fracture segments located in thoracic segments(T1-T10), thoracolumbar segments(T11-L1)and lumbar segments(L2-L5)were 18%, 46% and 36% in GIOP group and 11.9%, 58.7% and 29.4% in Control group (P>0.05). The refracture rate in GIOP group was higher than that in control group (23.8% vs. 6.0%). The survival rate was lower in GIOP group than that in control group (P<0.01).

CONCLUSION

The predilection site of VCF was similar in GIOP and primary osteoporosis (thoracolumbar segments> thoracic segments> lumbar segments). The risk of multiple segments VCF was higher in GIOP than in primary osteoporosis. The risk of vertebral refractures after PVP or PKP was higher in GIOP than in primary osteoporosis.

Developmental milestones in children born post-term in the Danish National Birth Cohort: a main research article

OBJECTIVE

To examine the timing of reaching developmental milestones in children born post-term.

DESIGN

Cohort study.

SETTING

The Danish National Birth Cohort: children born between 1997 and 2003.

POPULATION

Data were obtained from a cohort of 92 892 pregnancies participating in the first pregnancy interview. All singletons born in gestational weeks 39-45 were identified. The study was then restricted to children who participated in an interview at the age of approximately 18 months and had information on at least one developmental milestone. We excluded children of mothers with chronic diseases from the final analysis. The remaining study population constituted of 43 915 singletons (27 503 born at term; 16 412 born post-term).

METHODS

Logistic regression was used to calculate odds ratios of late achievement of these developmental milestones, adjusted for potential confounding factors.

MAIN OUTCOME MEASURES

Achieving developmental milestones at the time of interview or at a certain age.

RESULTS

More children born post-term achieved the assessed developmental milestones compared with children born at term (39-40 weeks). A test for trend for gestational ages 39, 40, and 41 weeks also showed a positive trend at achieving developmental milestones with gestational age at birth in nine out of 14 milestone items.

CONCLUSIONS

Children born post-term appear to reach the main developmental milestones at an earlier age than children born at term. The association could also result from bias related to a longer time between conception and interviewing, misclassification of end points, or selection bias.

Superconductivity in topological insulator Sb2Te3 induced by pressure

Topological superconductivity is one of most fascinating properties of topological quantum matters that was theoretically proposed and can support Majorana Fermions at the edge state. Superconductivity was previously realized in a Cu-intercalated Bi₂Se₃ topological compound or a Bi₂Te₃ topological compound at high pressure. Here we report the discovery of superconductivity in the topological compound Sb₂Te₃ when pressure was applied. The crystal structure analysis results reveal that superconductivity at a low-pressure range occurs at the ambient phase. The Hall coefficient measurements indicate the change of p-type carriers at a low-pressure range within the ambient phase, into n-type at higher pressures, showing intimate relation to superconducting transition temperature. The first principle calculations based on experimental measurements of the crystal lattice show that Sb₂Te₃ retains its Dirac surface states within the low-pressure ambient phase where superconductivity was observed, which indicates a strong relationship between superconductivity and topology nature.

Magnetic and structural transitions of SrFe2As2 at high pressure and low temperature

One of key issues in studying iron based superconductors is to understand how the magnetic phase of the parent compounds evolves. Here we report the systematic investigation of paramagnetic to antiferromagnetic and tetragonal to orthorhombic structural transitions of “122” SrFe₂As₂ parent compound using combined high resolution synchrotron Mössbauer spectroscopy and x-ray diffraction techniques in a cryogenically cooled high pressure diamond anvil cell. It is found that although the two transitions are coupled at 205 K at ambient pressure, they are concurrently suppressed to much lower temperatures near a quantum critical pressure of approximately 4.8 GPa where the antiferromagnetic state transforms into bulk superconducting state. Our results indicate that the lattice distortions and magnetism jointly play a critical role in inducing superconductivity in iron based compounds.

Resolvin D1 improves survival in experimental sepsis through reducing bacterial load and preventing excessive activation of inflammatory response

Sepsis is characterized as an uncontrolled inflammatory response. Spite et al. (Nature 461(7268):1287-1291, 2009) had demonstrated that resolvin D2, which is derived from docosahexaenoic acid (DHA), improves survival in cecal ligation and puncture (CLP)-initiated sepsis and enhances bacterial clearance without immune suppression. Resolvin D1, which is also derived from DHA and homologous with resolvin D2, is an endogenous anti-inflammatory and proresolving lipid molecule. We sought to investigate the effects of resolvin D1 on sepsis and to explore the mechanism of action. Six-to-eight-week-old male C57BL/6 mice were randomly divided into three groups: the sham group underwent the sham operation followed by tail vein injection of vehicle (0.1 % ethanol); the CLP group received vehicle (0.1 % ethanol) after CLP; the resolvin D1 group received resolvin D1 (100 ng) after CLP. Blood, peritoneal lavage fluid, and organs of mice were harvested 24 h after treatment for cytokine analysis, cell counts, bacterial cultures, histopathological studies, and apoptosis quantification. Compared with the vehicle control group, the survival rate and bacterial clearance of mice with sepsis induced by CLP were improved after resolvin D1 treatment, but the numbers of neutrophils in peritoneal lavage fluid, the inflammatory cytokines, the phosphorylation of the nuclear factor-κB (NF-κB) (P65) pathway, and the apoptosis rate of CD3(+) T lymphocytes of the thymus were suppressed. Resolvin D1 treatment improved survival in mice with sepsis induced by CLP, enhanced organism bacterial clearance, suppressed the increase of the numbers of neutrophils in peritoneal lavage fluid, reduced the release of inflammatory cytokines, and decreased the apoptosis rate of CD3(+) T lymphocytes of the thymus. These results suggest that resolvin D1 may attenuate the degree of inflammatory reaction in sepsis caused by CLP, without harming the host defense response.

Superconductivity of the topological insulator Bi2Se3 at high pressure

The pressure-induced superconductivity and structural evolution of Bi2Se3 single crystals are studied. The emergence of superconductivity at an onset transition temperature (Tc) of about 4.4 K is observed at around 12 GPa. Tc increases rapidly to a maximum of 8.2 K at 17.2 GPa, decreases to around 6.5 K at 23 GPa, and then remains almost constant with further increases in pressure. Variations in Tc with respect to pressure are closely related to the carrier density, which increases by over two orders of magnitude from 2 to 23 GPa. High-pressure synchrotron radiation measurements reveal structural transitions at around 12, 20, and above 29 GPa. A phase diagram of superconductivity versus pressure is also constructed.

Maternal cigarette smoking during pregnancy and pubertal development in sons. A follow-up study of a birth cohort

Epidemiological studies have raised concern about the reproductive consequences of prenatal cigarette smoking exposure, possibly affecting semen quality and onset of pubertal development of the offspring. The aim of this study was to further investigate pubertal development in young men exposed to cigarette smoking in foetal life. In a Danish pregnancy cohort, information on maternal smoking during pregnancy was available from questionnaires administered in 1984-1987, and information on pubertal development, assessed by age at first nocturnal emission, acne, voice break and regular shaving, was obtained from a follow-up questionnaire administered in 2005 to the young men (age: 18-21). We found no significant association between prenatal cigarette smoking exposure and earlier onset of puberty, but we did observe a tendency towards earlier age of first nocturnal emission, acne and voice break, indicating an accelerated age of pubertal development. Men exposed to ≥15 cigarettes/day had 3.1 months (95% CI: -6.4; 0.2) earlier age at acne and 2.2 months (95% CI: -7.3; 3.0) earlier age at first nocturnal emission, 1.2 months (95% CI: -4.6; 2.2) earlier age at voice break, however, 1.3 months (95% CI: -1.6; 4.3) later age at regular shaving, compared with unexposed men. Prenatal cigarette smoking exposure may induce an earlier age at onset of puberty in young men, but larger studies with prospectively collected data on pubertal development are needed to explore this hypothesis further.

Superconductivity above 33 K in (Ca(₁ - x)Na(x))Fe₂As₂

We report the synthesis of (Ca₀.₃₃Na₀.₆₆)Fe₂As₂ showing a superconducting transition with T(c) above 33 K. Both dc magnetic susceptibility or specific heat measurements indicated the bulk superconductivity nature of the sample. We also have successfully grown single crystals of the (Ca₀.₃₃Na₀.₆₆)Fe₂As₂ superconductors. The single crystals exhibit sharp superconducting transitions with T(c) above 33 K. The effects of magnetic field on the superconducting transitions are studied, giving rise to high upper critical fields with H(c₂)(c)≈85 T and H(c₂)(ab)≈172 T, respectively. The anisotropy parameter was calculated to be around 2.

Laboratory work and pregnancy outcomes: a study within the National Birth Cohort in Denmark

AIMS

To examine pregnancy outcomes in women doing laboratory work.

METHODS

Using data from the Danish National Birth Cohort (1997-2003), the authors conducted a prospective cohort study of 1025 female laboratory technicians and 8037 female teachers (as reference). The laboratory technicians were asked about laboratory work tasks during pregnancy in an interview (at around 16 weeks of gestation). Pregnancy outcomes were obtained by linking the cohort to the national registers. Hazard ratios (HRs) of late fetal loss and diagnosing of congenital malformations were calculated by using Cox regression, and odds ratios (ORs) of preterm birth and small for gestational age were calculated by using logistic regression.

RESULTS

Overall, there were no significant differences in pregnancy outcomes between laboratory technicians and teachers. However, we found that laboratory technicians working with radioimmunoassay or radiolabelling had an increased risk of preterm birth (OR = 2.2, 95% CI 0.8 to 6.2 for radioimmunoassay, and OR = 1.9, 95% CI 0.8 to 4.6 for radiolabelling) and "major" malformations (HR = 2.1, 95% CI 1.0 to 4.7 for radioimmunoassay, and HR = 1.8, 95% CI 0.9 to 3.7 for radiolabelling). The ORs of preterm birth doubled for women working with these tasks every day or several times a week. When an exposure matrix was applied, an increased risk of "major" malformations for exposure to organic solvents was seen.

CONCLUSIONS

The results did not indicate any high risk of reproductive failures in laboratory technicians in general. Exposure to radioisotopes may carry a high risk of preterm birth and congenital malformations. This finding deserves further investigation.

Shift work and subfecundity: a causal link or an artefact?

AIMS

The Danish National Birth Cohort (DNBC) was used to examine whether shift work is associated with reduced fecundity as estimated by time to pregnancy (TTP).

METHODS

From 1 March 1998 to 1 May 2000, 39 913 pregnant women were enrolled in the DNBC. Data on job characteristics and TTP (0-2, 3-5, 6-12, and >12 months) were used for 17 531 daytime workers and 3907 shift workers who had planned the pregnancy. Fecundity odds ratios (ORs) were calculated with 95% confidence intervals using the discrete time survival analysis techniques performed by logistic regression. An OR above 1 expresses a shorter TTP and then a higher fecundity. Potential confounders, such as age at conception, gravidity, prepregnant body mass index, smoking, and alcohol consumption, as well as occupational characteristics, were also included in the model.

RESULTS

Fixed evening workers and fixed night workers had a longer TTP. Compared with daytime workers, the adjusted ORs were 0.80 (95% CI 0.70 to 0.92) for fixed evening workers, 0.80 (95% CI 0.63 to 1.00) for fixed night workers, 0.99 (95% CI 0.91 to 1.07) for rotating shift (without night) workers, and 1.05 (95% CI 0.97 to 1.14) for rotating shift (with night) workers. When analysis was restricted to nulliparous women, the estimates remained unchanged. The proportions of unplanned pregnancies and contraceptive failures were higher among fixed evening and fixed night workers.

CONCLUSIONS

There was no unequivocal evidence of a causal association between shift work and subfecundity. The slightly reduced fecundity among fixed evening workers and fixed night workers may be mediated by pregnancy planning bias or differential options for sexual contacts.

Do parents of children with congenital malformations have a higher cancer risk? A nationwide study in Denmark

To investigate whether parents of children with congenital malformations more often developed cancer after birth of the child, a population-based case-control study in Denmark was undertaken. By linking the Cancer Registry with the Central Population Registry, we identified 8783 cancer patients having their first child born between 1977 and 1995 before the cancer was diagnosed. Parents of 41 206 firstborn children of a 10% random sample of newborns from the Birth Registry between 1980 and 1995 were identified as controls. We obtained malformation diagnoses of children of cases and controls by linking to the Hospital Discharge Registry. We estimated the association between malformation and cancer by using logistic regression, adjusting for maternal age at birth and sex of child. We found no increased risk of cancer in parents having children with malformations in general, but a higher cancer risk in parents of children born with cleft lip/palate, odds ratio (OR) for all cancer=1.8 (95% confidence interval 1.0-3.2), OR for lymphomas=4.2 (1.3-13.5) and OR for leukaemia=8.1 (2.0-33.7). This association was not restricted to cancer cases diagnosed shortly after birth of the child. Our results suggest a common genetic association between these diseases, but further studies are needed.

Insulin-responsive nuclear proteins facilitate Sp1 interactions with the insulin-like growth factor-I gene

The diabetes-induced decrease in insulin-like growth factor-I transcription appears to be mediated by footprint region V in exon 1. Since region V contains both an Sp1 site and an AT-rich element that recognizes an insulin-responsive binding protein (IRBP), we tested the hypothesis that Sp1 interactions are facilitated by an IRBP. Binding of nuclear extracts to region V probes was reduced by mutational or chemical interference with the AT-rich element. Blocking the AT site also reduced interactions of Sp1 with region V in vitro and blunted transactivation of region V reporter constructs by Sp1 in vivo. Sp1 binding was enhanced by small quantities of hepatic nuclear extracts, but enhancement was reduced by the AT mutation and abolished by a 5-base pair insertion between the AT-rich and GC-rich sites, and transactivation by Sp1 in vivo was diminished by inserting bases between the AT-rich and GC-rich elements. However, treating cells with insulin increased the ability of nuclear extracts to enhance Sp1 binding. These findings indicate that the presence of the AT-rich element is essential for the actions of Sp1 in vitro and in vivo, and the combination of both spacing requirements and insulin responsiveness suggests that IRBP may interact directly with Sp1.

[Relationship between protein loss and dialysis duration results of PET and KT/Vurea in CAPD patients]

The study focused on the relationship between protein loss and dialysis duration, results of PET and KT/Vurea in two groups of CAPD patients. 16 patients of one group were included in CAPD for only 30 days while 19 patients of the other group were included in CAPD for more than one year. The results showed that value of protein loss had no obvious significance between both groups. Compared with the patients with value of PET D/Pcr < 0.65, the patients with value of PET D/Pcr > or = 0.65 had no significant protein loss. Between the patients whose index of urea clearance > or = 2.0, and those index of uera clearance < 2.0 the protein loss had no difference. It is suggested that, in routine dialysis duration peritoneal transport of small solutes and dialysis adequency. The conclusion shows furtherly that transportion of large protein and small solutes through different ways.

Physiological concentrations of insulin promote binding of nuclear proteins to the insulin-like growth factor I gene

Limitations in understanding the mechanism of transcriptional regulation by insulin are due in part to lack of models in which there is insulin-responsive binding of nuclear factors to critical promoter regions. The insulin-like growth factor I (IGF-I) gene responds to diabetes status via a footprinted sequence, region V, which contains an AT-rich element and a GC-rich site. We tested the hypothesis that insulin regulates nuclear factor binding to the AT-rich site. Gel shift analysis with liver nuclear extracts and a region V probe showed binding of Sp1, Sp3, and B(1), which persisted despite the presence of antibodies against Sp1 and Sp3. B(1) was detected by a probe mutated in the GC-rich site (VmSp1), but not by a probe mutated at the AT-rich site (VmAT). We then asked whether B(1) was responsive to insulin. For both region V and VmSp1 probes, nuclear extracts from normal rat hepatocytes, H4IIE cells, and CHO-IR cells exposed to 10(-6) M insulin exhibited an increase in binding, designated insulin-responsive binding protein (IRBP); IRBP comigrated with B(1) from liver extracts. IRBP binding to region V was competed by VmSp1, but not by VmAT, indicating specific interactions with the AT-rich sequence; insulin response elements from other genes also failed to compete. After addition of insulin, IRBP began to increase by 1 h and rose further at 24 h, suggesting involvement of both posttranslational and transcriptional mechanisms. IRBP responded to as little as 10(-10) M insulin, indicating physiological relevance. Induction of IRBP was blunted by the phosphatidylinositol 3'-kinase inhibitor LY294002, whereas other signal transduction inhibitors had little effect. IRBP interacts with an important sequence in the IGF-I gene and may participate in the metabolic regulation of IGF-I expression. As most insulin-responsive genes do not exhibit insulin-responsive nuclear factor binding, further studies of IRBP may also contribute to understanding of the mechanism of insulin action on gene transcription.

Fatal occupational injuries in a new development area in the People's Republic of China

Fatal occupational injuries in a new development region in Shanghai in east China are described. All occupational deaths in the East Pujiang New Area during the period 1991 through 1997 were abstracted from multiple, overlapping source documents. There were 426 deaths and a crude mortality rate of 9.1 per 100,000 workers. The death rate was highest in 1995 (14.6%), when expansion in the area was most rapid. The construction sector accounted for 55% of the deaths, followed by manufacturing (23%) and transport, storage, and telecommunications (11%). Falls, collisions, struck by/against incidents, and electrocutions accounted for 80% of all deaths. Falls led all other causes of deaths (33%) and were particularly prevalent in the construction industry (46% of all deaths in construction). The development of ongoing, comprehensive injury surveillance systems in the People's Republic of China will be essential to target and evaluate injury prevention activities in the future.

Roles of tissue transglutaminase in ethanol-induced inhibition of hepatocyte proliferation and alpha 1-adrenergic signal transduction

The mechanisms by which ethanol inhibits hepatocyte proliferation have been a source of some considerable investigation. Our studies have suggested a possible role for tissue transglutaminase (tTG) in this process. Others have shown that tTG has two distinctly different functions: it catalyzes protein cross-linking, which can lead to apoptosis and enhancement of extracellular matrix stability, and it can function as a G protein (Galpha(h)). Under that circumstance, we speculated that the cross-linking activity would be decreased and that it would function to enhance hepatocyte proliferation in response to adrenergic stimulation. Ethanol treatment inhibited hepatocyte proliferation and led to enhanced tTG cross-linking activity, whereas treatment of hepatocytes with an alpha1 adrenergic agonist, phenylephrine, enhanced hepatocyte proliferation while decreasing tTG cross-linking. However, phenylephrine treatment of several hepatoma cell lines had no effect on cellular proliferation or tTG cross-linking activity, and of note, Northern blot analysis demonstrated that whereas primary hepatocytes had high levels of the alpha1beta adrenergic receptor (alpha1BAR) mRNA, the hepatoma cell lines did not have this mRNA. When the Hep G(2) cell line was stably transduced with an expression vector containing the alpha1BR cDNA, the cell line responded to phenylephrine treatment with enhanced proliferation and with decreased tTG cross-linking activity. Ethanol treatment of the alpha1BAR-transfected cells suppressed the phospholipase C-mediated signaling pathways, as detected in the phenylephrine-induced Ca(2+) response. These results suggest that phenylephrine stimulation of hepatocyte proliferation appears to be occurring through the alpha1BAR, which is known to be coupled with the tTG G protein moiety, Galpha(h), and that tTG appears to play a significant role in either enhancing or inhibiting hepatocyte proliferation, depending on its cellular location and on whether it functions as a cross-linking enzyme or a G protein.

Involvement of Sp1 in the transcriptional regulation of the rat insulin-like growth factor-1 gene

Most insulin-like growth factor-I (IGF-I) transcripts are initiated in exon 1, but mechanisms of regulation are not well understood. Since potential Sp1 sites are found in footprinted regions within approximately 360 bp upstream and downstream from the major initiation sites in exon 1, we explored the involvement of Sp1 and Sp3 in regulation of IGF-1 expression. Gel shift assays showed strong Sp1 binding to the downstream site, but binding to the upstream site was weak; Sp1 bound to a CCTGCCCA sequence in downstream footprint region V, and Sp3 binding was centered on the same sequence. IGF-I basal promoter constructs containing a mutation in the downstream Sp1 site exhibited a 32% decrease in expression in CHO cells and a 75% decrease in HepG2 cells, indicating the importance of Sp1 for expression in vivo. Sp1 and Sp3 expression vectors provided three- to five-fold stimulation of wild-type IGF-I constructs, but had little effect on a construct containing a mutation in the downstream Sp1 site, and Sp1 had comparable effects in Drosophila SL2 cells. IGF-I heterologous promoter constructs exhibited similar responses: in both SL2 cells and CHO cells, stimulation by Sp1 was enhanced with constructs containing downstream region V. Since Sp1 also stimulated expression of concatamers of putative cis-acting sites fused to the SV40 promoter enhancer in pGL3, the results in combination indicate that the presence of IGF-I region V is sufficient to permit stimulation by Sp1.

CONCLUSION

Sp1 and related factors may play an important role in the regulation of IGF-I gene transcription, through interactions with region V downstream from the major initiation sites in exon 1.

[Epidemiology of dental caries and periodontal diseases in middle school students in Suzhou City]

OBJECTIVE

To assess the prevalence of dental caries and periodontal diseases in middle school students at the ages of 11 to 13 and 15 to 17.

METHODS

Dental caries and periodontal diseases were assessed strictly by "national survey table of dental caries and periodontal diseases for school students".

RESULTS

The study group consisted of 20 581 students. The percentage of dental caries, DMFT and DMFS in students 11 to 13 years of age were 23.6%,0.40 and 0.54, respectively. The corresponding results were 29.76%, 0.64 and 0.87 for students 15 to 17 years of age, respectively. The percentage of gingivitis and dental calculus in students 11 to 13 years were 75.33% and 35.86%, respectively. The corresponding values in students 15 to 17 years of age were 73.1% and 44.91%, respectively. Female students have significantly few gingivitis and dental calculus than male students in both groups.

CONCLUSION

Compared with the students at the same ages in other cities, students in Suzhou city have low percentage of dental caries and periodontal diseases.

Identification of core sequences involved in metabolism-dependent nuclear protein binding to the rat insulin-like growth factor I gene

In the liver, most insulin-like growth factor I (IGF-I) transcripts originate in exon 1, where important cis-regulatory regions are located downstream from the major transcription initiation sites. Within these regions, we have attempted to identify sequences which are involved in the decrease in IGF-I gene transcription associated with diabetes mellitus. The function of different genomic templates was assessed by in vitro transcription, which revealed a consistent 50-80% decrease in the activity of nuclear extracts from streptozotocin-diabetic as compared with normal rats. The disparity in transcriptional activity between normal and diabetic nuclear extracts was reduced with templates containing 11-bp mutations within DNase I protected regions III or V (+42 and +129 bp, respectively, from the major transcription initiation site), but a mutation between regions IV and V had little effect. Within region III, gel mobility shift analysis and methylation interference studies indicated that DNA-protein interactions involve a GCGC core sequence. In region V, gel mobility shift studies and uracil interference analysis revealed interactions involving a TTAT core. While gel mobility shift analysis and transient transfection studies indicate that the GCGC core sequence in region III recognizes C/EBP, the AT-rich sequence in region V is likely to recognize a protein with homeodomain characteristics. Identification of the nuclear factor(s) interacting with regions III and V, downstream from exon 1 initiation sites, will be important for understanding the mechanism of reduced IGF-I gene transcription due to diabetes mellitus.

Analysis of 541 cases of occupational acute chemical injuries in a large petrochemical company in China

The authors carried out a descriptive analysis of acute chemical intoxication in a large petrochemical corporation with 38,000 employees, located in a suburban district of Shanghai, China, to determine the chemicals involved and the primary causes of the incidents. Between 1977 and 1997, 350 cases of acute chemical-intoxication were recorded, resulting in a total of 541 workers with symptoms. Of these, 483 were male and 58, female, with over half the victims under 30 years old. Two hundred and seventy-five cases were serious enough to necessitate hospital admission. There were 266 cases of chemical irritation or inhalation responses (49.2%), 215 cases of mild chemical poisoning (39.7%), 31 cases of moderate poisoning (5.7%), and 29 cases resulting in critical injury (5.4%), including eight deaths (1.5%). The main causes of injury reported by patients were lack of training about safety (63%) and equipment failure (23%). The chemicals involved were asphyxiating gases (302 cases; 55.8%), irritating gases (111 cases; 20.5%), and other toxins. Intervention strategies for the prevention of acute chemical exposures were suggested to the corporation.

A study on oxidative stress in lead-exposed workers

To explore the possible oxidative stress induced by lead, heparinized whole blood and urine of 66 secondary smelter lead workers (46 for Comet assay) and 28 controls were collected. The concentrations of blood lead (BPb) and urinary lead (UPb) and alpha-aminolevulinic acid (alpha-ALA), indices of lead exposure level of the body, were determined. Malondialdehyde (MDA) concentrations and superoxide dismutase (SOD) activity of plasma were also measured. Single-cell gel (SCG, Comet assay) was used to measure the DNA damage of peripheral blood cells. There was a positive correlation between the presence of Pb in blood and significant increases in MDA levels and SOD activity. Alcohol consumption and smoking with increased exposure to Pb was associated with enhanced DNA damage. A positive correlation was found between MDA and DNA damage.

Effects of class III antiarrhythmic agents in an in vitro rabbit model of spontaneous torsades de pointe

Acquired long QT syndrome develops as a result of pharmacological interventions that prolong action potential duration. Excessive action potential prolongation may lead to torsade de pointes, a potentially fatal arrhythmia. To study this arrhythmia, in vivo models have been developed, but are difficult to interpret due to the complex nature of the intact metabolic, nervous and humoral systems. To more clearly examine the propensity of various Class III agents to elicit torsades de pointe, an in vitro model of spontaneous torsades de pointe was used in isolated perfused rabbit hearts. Male New Zealand white rabbits were anesthetized with sodium pentobarbital, and hearts isolated and perfused in a Langendorff apparatus. Electrocardiogram and epicardial monophasic action potentials were continuously recorded, and methoxamine (30 nM) and acetylcholine (0.3 microM) were given throughout the experiment. After 10 min of methoxamine and acetylcholine perfusion, Class III agents, dofetilide (0.1 to 0.7 microM), E-4031 (0.1 to 0.5 microM), D-sotalol (10 to 30 microM), or clofilium (0.1 to 0.3 microM), were given. All agents, except D-sotalol, induced torsades de pointe in 100% of hearts tested. D-Sotalol (30 microM) elicited a low incidence of torsades de pointe (25%). This could be explained by the limited prolongation of action potential duration with D-sotalol as compared to other Class III agents under these conditions. Dofetilide, a selective Class III agent, alone did not induce torsades de pointe. Nadolol (3 microM), a beta-adrenoceptor antagonist, increased the propensity of dofetilide to elicit torsades de pointe. In conclusion, increases in action potential duration (i.e., using Class III agents) in combination with a low heart rate (muscarinic receptor stimulation) and increases in intracellular Ca2+ (alpha-adrenoceptor stimulation) are needed to develop torsades de pointe in this model. Modulating these systems may provide us with new insights into preventing the initiation or maintenance of this arrhythmia.

Increased liver uptake of liposomes and improved targeting efficacy by labeling with asialofetuin in rodents

To improve liposome-directed therapy of liver disease and gene delivery, it would be beneficial to selectively target hepatocytes. For this purpose, conventional liposomes (CL) were labeled with asialofetuin (AF), an asialoglycoprotein. The biodistribution of AF-labeled liposomes (AF-L) in mice and their incorporation into rat hepatocytes, and their potential use in acute liver injury, were investigated. AF-L displayed a quicker plasma clearance than CL, and 25.4%, 2.7%, and 1.2% of the injected dose remained in the plasma versus 47.0%, 26.1%, and 9.5% of CL, respectively at 2, 4, and 20 hours after the injection. Total liver uptake of AF-L (73%+/-3.9%) was markedly higher (P < .005) than CL (16.5%+/-1.8%) 4 hours after the injection. Liposomal radioactivity (cpm/mg) was greatly enhanced in the liver (11-fold) during the first 4 hours after the administration of 14C-AF-L, and was much higher than in 14C-CL-injected mice (1.5-fold). In vitro incubation of isolated rat hepatocytes with 14C-AF-L or intravenous injection of 14C-AF-L in rats resulted in higher hepatocyte-bound radioactivity compared with 14C-CL (P < .01-.005). AF-L-associated 1,1'-dilinoleyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) fluorescent signals were not only located in Kupffer cells, but also in hepatocytes, in which bile canaliculus networks were imaged. Intravenous administration of vitamin E (VE)-associated CL (VE-CL, 1 mg/mouse) significantly lowered alanine transaminase (ALT) levels in CCl4-treated mice (196+/-79 vs. 2,107+/-235 U/mL; P < .01). The ALT level in CCl4 + VE-AF-L group was decreased to 38+/-16 units/mL, which was significantly lower than the CC14 + VE-CL group (P < .05). In conclusion, labeling liposomes with AF led to a shortened liposome plasma half-life and greatly enhanced uptake of AF-L liposome by the liver. The enhanced uptake resulted from an increased incorporation of hepatocytes with AF-L liposomes. VE-associated AF liposomes further improved the protective effect of VE liposomes on CC14-induced acute liver injury in mice. Preferential hepatocyte incorporation of AF-L liposomes suggests a useful hepatocyte-targeting approach for drug delivery and gene transfection.

Proarrhythmic effects of pinacidil are partially mediated through enhancement of catecholamine release in isolated perfused guinea-pig hearts

The contribution of adrenergic stimulation to the proarrhythmic effects of pinacidil (30 microM), an opener of ATP-sensitive potassium channels (K+ATP), was tested in an isolated guinea-pig heart model of global ischemia (10 min) and reperfusion (10 min). None (0%) of the control hearts (n=10) elicited arrhythmias during ischemia or reperfusion. In the pinacidil-treated group, one heart (5%) experienced episodes of ventricular tachycardia (VT)/fibrillation (VF) during normoxia. During ischemia, 63% (12 out of 19) of pinacidil-treated hearts exhibited episodes of VT or VF. Hearts not in VT or VF (n=7) at the time of reperfusion, exhibited 71% VT and 43% VT/VF upon reperfusion. Proarrhythmic effects of pinacidil during ischemia or reperfusion were completely reversed by glyburide (n=9; 10 microM), a K+ATP antagonist, or nadolol (n=9; 3 microM), a beta-adrenergic antagonist. Isoproterenol (n=10; 50 nM), a beta-adrenergic agonist, induced a 20% incidence of ischemic VT and VF, and a 70% incidence of reperfusion VF, while methoxamine (n=10; 10 microM), an alpha-adrenergic agonist, demonstrated little proarrhythmia (20% VT/VF at reperfusion only). Proarrhythmic effects of isoproterenol were reversed by nadolol, but not glyburide. Pinacidil caused a slight potentiation of tachycardia induced by a bolus injection of tyramine (30 micro g), an indirectly acting sympathomimetic, but bolus injections of pinacidil (100 micro g) had no effect on heart rate. Nisoxetine, a catecholamine uptake 1 inhibitor, had no proarrhythmic effects when given alone. Catecholamine levels were reduced in pinacidil-treated hearts relative to vehicle-treated. In conclusion, it is suggested that the proarrhythmic effects of pinacidil following global ischemia and reperfusion in the isolated perfused guinea-pig heart appears to involve stimulation of beta-adrenoceptors. These proarrhythmic effects of pinacidil do not appear to be mediated solely through direct opening of K+ATP, but rather through an indirect enhancement of catecholamine release.

Prior immunity-related medical conditions and pancreatic-cancer risk in Shanghai

To investigate the role of immunity-related medical conditions in the etiology of pancreatic cancer, we analyzed data from a population-based case-control study of pancreatic cancer conducted in Shanghai during 1992 and 1993. Information on prior histories of selected auto-immune diseases and allergic conditions was obtained from 108 incident pancreatic-cancer cases and 275 age- and gender-frequency matched controls by face-to-face interviews using a structured questionnaire. A prior history of auto-immune diseases was associated with a 2-fold elevated risk of pancreatic cancer (95% CI = 1.0-4.2), with an indication of a dose-response relation for the number of reported diseases. In contrast, a prior history of allergic condition was related to reduced risk (OR = 0.6, 95% CI = 0.4-1.1). With the possible exception of drug allergy, such an inverse association was seen for virtually all allergic conditions., although none of the OR was statistically significant. This study suggests that host immune function may be involved in the etiology of pancreatic cancer. Further investigations into the mechanism of these observed associations are warranted.

Transcriptional regulation of the rat insulin-like growth factor-I gene involves metabolism-dependent binding of nuclear proteins to a downstream region

Insulin-like growth factor-I (IGF-I) gene transcription is mediated largely via exon 1. In an initial search for regulatory regions, rat hepatocytes were transfected with IGF-I constructs. Since omission of downstream sequences led to reduced expression, we then used in vitro transcription to evaluate potential metabolic regulation via downstream regions. With templates including 219 base pairs of downstream sequence, transcriptional activity was reduced 70-90% with hepatic nuclear extracts from diabetic versus normal rats. However, activity was comparable with templates lacking downstream sequences. The downstream region contained six DNase I footprints, and templates with deletion of either region III or V no longer provided reduced transcriptional activity with nuclear extracts from diabetic rats. Nuclear protein binding to regions III and V appeared to be metabolically regulated, as shown by reduced DNase I protection and activity in gel mobility shift assays with nuclear extracts from diabetic rats. Southwestern blotting probes corresponding to regions III and V recognized a approximately 65-kDa nuclear factor present at reduced levels in diabetic rats. These findings indicate that a downstream region in exon 1 may be important for both IGF-I expression and metabolic regulation. Altered concentration or activity of a transcription factor(s) binding to this region may contribute to reduced IGF-I gene transcription associated with diabetes mellitus.

Loss of the C-terminal serine residue from bovine beta B2-crystallin

Electrospray mass spectrometric (ES-MS) examination of bovine beta-crystallins showed a significant component corresponding in mass to beta B2-crystallin less one serine residue. Tryptic digestion, followed by isolation and characterisation of the C-terminal peptide, demonstrated that this new species has arisen by the loss of the C-terminal serine residue. This phenomenon appears to be age-related since no truncation was detected in beta B2-crystallin from foetal lenses and the proportion of the truncated form, as judged by ES-MS, was lower in beta-crystallin isolated from calf lenses than that from the lenses of 3-year-old animals. This process therefore is similar to a recently reported loss of the C-terminal serine from alpha A-crystallin, which we have confirmed using ES-MS. Loss of a C-terminal serine from both crystallins may indicate the presence of carboxypeptidase-A-like activity in bovine lenses. ES-MS data provided no evidence for a significant degree of phosphorylation of beta B2-crystallin.

5-Fluoro-2-pyrimidinone, a liver aldehyde oxidase-activated prodrug of 5-fluorouracil

5-Fluorouracil (5-FU) is an effective antitumor agent used in treating various cancers. Because of its metabolism by intestinal and other cells, 5-FU has an inconsistent bioavailability that limits its oral use. 5-Fluoro-2-pyrimidione (5-FP), a 5-FU prodrug, was synthesized and found to be converted to 5-FU by aldehyde oxidase, an enzyme present in high concentrations in the livers of mice and humans but not in the gastrointestinal tract. Using BDF1 mice, the pharmacokinetics of 5-FP were studied and compared with those of 5-FU. The bioavailability of 5-FP given orally was 100% at a dosage of 25 mg/kg and 78% at a dosage of 50 mg/kg. The half-lives of both doses of 5-FP were at least 2-fold longer than the half-lives of the same doses of 5-FU, and the clearance rates of 5-FP were 3-fold slower. 5-FP was converted rapidly to 5-FU, in vivo. The resulting 5-FU was measured at a steady-state level of 40-70 microM in plasma, at a dosage of 25 mg/kg, that was sustained for at least 4 hr. Also, when given orally, 5-FP was shown to have potent activity against Colon 38 tumor cells and P388 leukemia cells in mice. The therapeutic index of 5-FP was similar to that of 5-FU in these mouse tumor models. The potential clinical use of 5-FP as a prodrug of 5-FU should be considered.

Contribution of cardiac and arterial baroreceptors to enhanced vasopressin release during hemorrhage with autonomic blockade

During episodes of blood loss, several apparently redundant mechanisms are activated to maintain arterial blood pressure. This study was designed to examine one such compensatory mechanism involving enhanced vasopressin release during hemorrhage when the autonomic nervous system (ANS) is pharmacologically blocked. First, to confirm that this compensatory mechanism exists in canines, conscious dogs were hemorrhaged under normal conditions and during ANS blockade. In dogs with intact cardiac nerves (intact, n = 7), hemorrhage at 0.8 ml/kg/min increased plasma vasopressin (PAVP) from 3.0 +/- 0.7 to 6.6 +/- 2.4 and 78 +/- 50 pg/ml at blood losses of 10 and 20 ml/kg, respectively. At the same amount of blood loss during hemorrhage with ANS blockage, PAVP was enhanced significantly from 33 +/- 17 to 230 +/- 90 and 610 +/- 270 pg/ml. ANS blockade did not, however, alter the hemorrhage-induced increases in plasma renin activity. Next, to examine the afferent mechanisms responsible for the enhanced PAVP response, cardiac-denervated dogs (CD, n = 9) were hemorrhaged with and without ANS blockade. Without blockade, PAVP increased from 3.7 +/- 0.9 to 5.2 +/- 0.8 and 26 +/- 11 pg/ml at blood losses of 10 and 20 ml/kg. PAVP was significantly higher in response to hemorrhage with ANS blockade, increasing from 17 +/- 6 to 76 +/- 18 and 330 +/- 80 pg/ml. The rise in PAVP in the CD dogs suggested that peripheral baroreceptors were involved in eliciting vasopressin release under these conditions. Therefore, the influence of arterial baroreceptors was examined by infusing norepinephrine during hemorrhage in order to maintain blood pressure constant. Under these conditions, PAVP increased significantly in the intact dogs at 10 ml/kg blood loss, but did not change in the CD dogs. These results demonstrate that the enhanced release of AVP during hemorrhage with ANS blockade can be mediated either by cardiac or arterial baroreceptors; however, the maximum response is elicited only when both sets of receptors are functioning normally.

In vitro effects of capsaicin: antiarrhythmic and antiischemic activity

The antiarrhythmic effects of vehicle (0.1% dimethyl sulfoxide: DMSO) or capsaicin were evaluated in isolated perfused rat and guinea pig heart preparations. In the rat, capsaicin reduced ischemic ventricular tachycardia from 100% in control to 0%, and ischemic ventricular fibrillation from 60% in control to 0% at 30 microM, and diltiazem reduced the incidence of ischemic ventricular tachycardia and ventricular fibrillation to 55% and 0%, respectively. Reperfusion ventricular fibrillation was reduced from 90% to 20% and 33% for capsaicin and diltiazem, respectively, at these concentrations. In isolated perfused globally ischemic rat hearts, antiischemic efficacy was assessed as a significant extension (36% and 50%) in time to contracture with 30 microM capsaicin and 1 microM diltiazem, respectively. Capsaicin reduced left ventricular developed pressure by 35% in non-ischemic rat hearts, and increased coronary flow by 40%. The increased time to contracture for either compound was not blocked by glyburide (0.1 microM) suggesting a lack of any involvement of ATP-sensitive K+ channels. In isolated guinea pig hearts subjected to global ischemia, capsaicin and diltiazem reduced reperfusion ventricular fibrillation from 100% to 10% and 0% at 30 and 3 microM, respectively. Electrophysiologic evaluation in guinea pig papillary muscles using standard microelectrode techniques demonstrated significant (P < 0.05) action potential durations at 90% repolarization shortening at 1 Hz by 9%, 28% and 39%, and 23%, 37% and 51% at 10, 30, and 100 microM of capsaicin or diltiazem, respectively. Unlike diltiazem, no changes in action potential duration were observed with capsaicin (up to 100 microM) at faster stimulation rates (5 Hz). In conclusion, capsaicin displays both antiarrhythmic and antiischemic efficacy. These data suggest that the effects of capsaicin are mediated primarily through block of Ca2+ channels in these preparations.