[Analysis of developmental coordination disorder in Chinese children]

Objective: To investigate the prevalence of children's developmental coordination disorder (DCD) and its distribution based on different family socioeconomic characteristics in China, in order to provide a theoretical basis for early prevention, diagnosis, and intervention for DCD. Methods: From June to October, 2016, 1 887 children aged 3-10 years from 20 kindergartens and 10 elementary schools from 8 cities in seven geographic areas of China using a stratified cluster sampling method were recruited. With a cross-sectional design, parents were asked to report on their basic information. Children' s motor ability was assessed using the movement assessment battery for children-second edition (MABC-2). Children were grouped by age, sex, body mass index (BMI), one-child status, and family structure. Chi-square test and one-way ANOVA were used to compare family socioeconomic characteristics of children between different groups. Results: Among the 1 887 children, there were 1 110 (58.8%) preschool children (3-6 years of age) and 777 (41.2%) school-aged children (7-10 years of age). There were 982 males (52.0%) and 905 females (48.0%). A total of 5.5% (104 cases) children were diagnosed with DCD, 10.4% (197 cases) with suspected DCD, and 84.1% (1 586 cases) as typical motor developing children. There were no significant differences in prevalence of diagnosed and suspected DCD among different regions (χ²=17.342 and 4.877, P=0.173 and 0.560), total motor coordination score (F=2.759, P<0.05), and the scores of all dimensions (manual dexterity, positioning and grabbing, balance: F=9.276, 5.277, 3.706, all P<0.01). The prevalence of DCD in preschool children was significantly higher than that in school-age children (χ²=11.891, P<0.01). Girls were significantly better than boys in total motor coordination, manual dexterity, and balance (all P<0.01). Boys were significantly better than girls in positioning and grabbing (P<0.01). The prevalence of DCD in boys was significantly higher than that in girls (70 boys (7.1%) and 34 girls (3.8%), χ²=28.508, P<0.01). The total motor coordination ability, manual dexterity and balance of children who are overweighted (BMI>18 kg/m²) were significantly lower than those of children of normal weight (BMI≤18 kg/m²) (all P<0.01). The prevalence of suspected DCD children who are overweighted was significantly higher than that of children of normal weight (χ²=4.369, P<0.05). The difference of total motor coordination ability (F=6.811, P<0.01) and the prevalence of DCD (χ²=14.902, P<0.01) among different family structures were statistically significant. The total motor coordination ability and balance ability of children from multi-child family were better than those of children from one-child family (both P<0.05). Conclusion: The motor coordination ability of Chinese children is well-developed, with differences among different regions, gender, age, BMI, and family structure.

A survey on parasites in wild rodents in Xiji County, a northwestern part of China

Rodents act as an indicator for evaluation of environment contaminations and public health risks caused by parasites. A survey of parasites in wild rodents was conducted in 14 villages in Xijin County, where alveolar echinococcosis by Echinococcus multilocularis is epidemic. In total, 72 rodents including 25 mice, 16 Citellus dauricus (Daurian ground squirrel), 12 squirrels and 19 mole rat (Myospalax fontanieri) were captured. Infections (2.8%) of Taenia taeniaeformis, which is transmitted mainly between mice and cats, were found in mice in Wangping (WP) and Miaoping (MP) villages, but other cestodes' infections were not observed. WP and MP isolates were principally similar in morphology but, unlike WP isolate, MP isolate had no hooks on the scolex. Using 18S rRNA as a biomarker, the phylogenetic analysis showed that WP and MP isolates grouped together with European and Asian isolates and formed a separate cluster. These results highlights the prevalence of T. taeniaeformis in cats or/and dogs and a risk of opportunistic infections in human populations.

High expression of long non-coding RNA ATB indicates a poor prognosis and regulates cell proliferation and metastasis in non-small cell lung cancer

BACKGROUND AND AIM

Long non-coding RNAs (lncRNAs) have been demonstrated to act as a critical regulator in the processes of tumor biology. In this study, whether lncRNA-ATB is a potential indicator for non-small cell lung cancer (NSCLC) was investigated and its biological function in NSCLC was also determined.

METHODS

The expression levels of lncRNA-ATB in NSCLC tissues and cell lines were measured. A549 cell line was explored to investigate the functions of lncRNA-ATB in NSCLC.

RESULTS

Real-time PCR results showed that lncRNA-ATB expression was up-regulated in both in NSCLC tissues and cell lines. High lncRNA-ATB expression in tumor tissue was associated with larger tumor size, lymph node metastasis, and distant metastasis in patients with NSCLC, respectively. In addition, the patients with high expression of lncRNA-ATB presented a lower survival probability. In vitro experiments showed that down-regulation of lncRNA-ATB promoted the cell apoptosis, whereas inhibited the cell viability, cell migration, and cell invasion.

CONCLUSION

High expression of lncRNA-ATB indicated a poor prognosis and led to the cell proliferation and metastasis in NSCLC.

The prevalence of hepatitis A virus and parvovirus B19 in source-plasma donors and whole blood donors in China

AIMS

To compare the prevalence of hepatitis A virus (HAV) and human parvovirus B19 (B19V) between source-plasma (SP) donors and whole blood (WB) donors.

BACKGROUND

In China, source plasma is in severe shortage while plasma recovered from WB is in surplus. Thus, the government is considering transferring the recovered plasma (RP) to produce plasma derivatives. HAV and B19V are two pathogens threatening the safety of plasma-based derivatives. However, there is no data about if transferring of the RP to produce plasma derivatives will increase the risk of HAV and B19V infection. Thus, we compared the prevalence of HAV and B19V between SP donors and WB donors in this study.

METHODS

A total of 5030 samples from SP donors and 5040 samples from WB donors were collected. All the samples were tested for HAV RNA and B19V DNA and tested for HAV IgM by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The prevalence of B19V DNA was 0.06% (95% confidence interval (CI), 0-0.09%) in WB donors and 0.079% (95% CI, 0-0.12%) in SP donors, respectively. No significant difference was found in the prevalence of B19V DNA between SP donors and WB donors. The prevalence of anti-HAV IgM in SP donors was 0.079% whereas no WB donor sample was found anti-HAV IgM reactive.

CONCLUSIONS

The transfer of RP to producing plasma derivatives will not increase the risk of transmission of HAV and B19 through plasma products.

Role of surgery in the management and prognosis of limited-stage small cell carcinoma of the esophagus

Small cell carcinoma of the esophagus (SCCE) is a rare, highly aggressive tumor characterized by early dissemination and a poor prognosis. Surgery, chemotherapy, and radiotherapy have been used alone or in combination for the treatment of this rare disease. The aim of this retrospective study was to analyze the role of surgery in the management of limited-stage SCCE at a high-volume center. We retrospectively evaluated 73 patients with limited-stage SCCE who received an esophagectomy at our center from January 1994 to December 2011. The clinical characteristics, median survival times (MSTs), overall survival (OS), and relevant prognostic factors were analyzed. The overall MST was 23.0 months, and the 1-, 2-, 3-, and 5-year OS rates were 61.6%, 47.9%, 22.7%, and 10.6%, respectively. The MST for patients without lymph node involvement (33.0 months) was greater than the MST for patients with lymph node involvement (17.0 months) (P = 0.014). Similarly, patients who underwent radical resection had a greater MST (25.0 months) than patients who underwent palliative resection (7.0 months) (P = 0.004). Patients who received chemotherapy had a greater MST (27.0 months) than patients who did not receive chemotherapy (13.0 months) (P = 0.021). Survival analysis confirmed that a radical operation, chemotherapy, and lymph node involvement were independent prognostic factors. This study suggests that radical resection combined with chemotherapy should be recommended for patients with limited-stage SCCE, especially patients with negative regional lymph nodes. A lack of lymph node metastasis was a good prognostic factor because patients without lymph node involvement had greater OS.

Vitamin D and parathyroid hormone status in a representative population living in Macau, China

Associations between documented sun-exposure, exercise patterns and fish and supplement intake and 25-hydroxyvitamin D (25OHD) and parathyroid hormone (PTH) were investigated in a random household survey of Macau residents (aged 18-93). Blood samples (566) taken in summer were analyzed for 25OHD and PTH. In this Chinese population, 55% were deficient (25OHD <50nmol/L: median (interquartile range)=47.7 (24.2) nmol/L). Vitamin D deficiency was greatest in those aged <50 years: median (interquartile range)=43.3 (18.2) nmol/L, females: median (interquartile range)=45.5 (19.4) nmol/L and those with higher educational qualifications: median (interquartile range)=43.1 (18.7) nmol/L. In the total Macau population, statistically significant (p<0.01) modifiable associations with lower 25OHD levels were sunlight exposure (β=0.06), physical activity (PA) (measured as hours(hrs)/day: β=0.08), sitting (measured as hrs/day β=-0.20), intake of fish (β=0.08) and calcium (Ca) supplement intake (β=0.06) [linear regression analysis adjusting for demographic risk factors]. On similar analysis, and after adjustment for 25OHD, the only significant modifiable associations in the total population with PTH were sitting (β=-0.17), Body Mass Index (β=0.07) and Ca supplement intake (β=-0.06). In this Macau population less documented sun exposure, fish and Ca supplement intake and exercise were associated with lower 25OHD levels, especially in the younger population, along with the interesting finding that more sitting was associated with both lower 25OHD and high PTH blood levels. In conclusion, unlike findings from Caucasian populations, younger participants were significantly more vitamin D deficient, in particular highly educated single females. This may indicate the desire of young females to be pale and avoid the sun. There are also big differences in lifestyle between the older generation and the younger, in particular with respect to sun exposure and PA. This article is part of a Special Issue entitled '17th Vitamin D Workshop'.

Feedback control of TET system with variable coupling coefficients for a novel artificial anal sphincter

For treating severe faecal incontinence, the authors developed an intelligent artificial anal sphincter system (AASS) equipped with a feedback sensor that utilized a transcutaneous energy transfer system (TETS). To deliver the correct amount of power (i.e. to match the load demand under variable coupling conditions caused by changes in positioning between the coils due to fitting and changes in posture), a regulating method to stabilize output voltage with a closed loop variable-frequency controller was developed in this paper. The method via which the voltage gain characteristics of a voltage-fed series-tuned TETS were derived is also described. The theoretical analysis was verified by the results of the experiment. A numerical analysis method was used as a control rule with respect to the relationship between operating frequency and output voltage. To validate the feedback control rules, a prototype of the TET charging system was constructed, and its performance was validated with the coupling variation between 0.12-0.42. The results show that the output voltage of the secondary side can be maintained at a constant 7 V across the whole coupling coefficient range, with a switching frequency regulation range of 271.4-320.5 kHz, and the proposed controller has reached a maximal end-to-end power efficiency of 67.5% at 1 W.

Hypertension, pulse, and other cardiovascular risk factors and vitamin D status in Finnish men

BACKGROUND

Debate exists about the relationship between hypovitaminosis D and cardiovascular (CVD) risk.

METHODS

This study investigated baseline (n=2,271) 25-hydroxyvitamin D (25(OH)D) and baseline and 4 year (n=1,957) CVD risk in a cohort of Finnish middle-aged male smokers.

RESULTS

The prevalences of measured hypertension, high pulse rate, diabetes, and coronary heart disease were 63%, 16%, 5%, and 10% at baseline and were 64%, 20%, 6%, and 16% at 4 years after baseline. The mean 25(OH)D was 41±18 nmol/L. At baseline, systolic blood pressure (β = -0.048; P = 0.02), and pulse rate (β = -0.043; P = 0.04) were both associated with lower 25(OH)D levels but not coronary heart disease or diabetes prevalence. On remeasuring CVD risk 4 years after baseline, the only significant association with baseline 25(OH)D levels was high pulse rate (β = -0.077; P = 0.001). In addition, a higher 25(OH)D level at baseline was associated with a change in pulse rate (β = -0.055; P = 0.01). These trends for hypertension (baseline) and high pulse rate (baseline and 4 years after baseline) were also seen on adjusted categorical analysis (P trend < 0.05).

CONCLUSIONS

Vitamin D deficiency at baseline was associated with hypertension in Finnish male smokers, but not after 4 years. These results are consistent with recent findings in other large cohort studies with measured blood pressure. Change in pulse rate over time continued to be significantly associated with lower 25(OH)D baseline levels; this new finding should be investigated further.

Prevalence, awareness, treatment, and control of hypertension among herdsmen living at 4,300 m in Tibet

BACKGROUND

Studies on blood pressure (BP) in high-altitude areas are scarce and the results are controversial. Tibetans live in regions at high altitudes, and data on the prevalence of hypertension in this population is not currently well known.

METHODS

All Tibetans aged 40 years and older living in the township of Yangbajing (4,300 m) in Tibet, China were invited to participate in the 2009 survey. BP was measured with electronic sphygmomanometers (calibrated by the results of a previous study). Histories of hypertension and medication use were collected through face-to-face interviews. Hypertension was defined as systolic BP (SBP) ≥140 mm Hg and/or diastolic BP (DBP) ≥90 mm Hg, or antihypertensive medication use in the past 2 weeks.

RESULTS

A total of 701 adults (aged 40-89, 42.9% male, 94.9% herdsmen) were recruited. The mean (s.d.) SBP/DBP was 146.6 (31.3)/92.0 (15.7) mm Hg and the prevalence of hypertension was 55.9%. Of note, 61.2% of those with hypertension had stage 2 hypertension (SBP ≥160 or DBP ≥100 mm Hg). At age 70 years and older, the mean (s.d.) SBP/DBP were 182.8 (30.9)/102.6 (13.4) mm Hg. Among those with hypertension (n = 392), only 19.9% were aware of their condition, 2.6% were taking medication, and only one participant had controlled BP.

CONCLUSION

According to our survey in Yangbajing, Tibetan adults aged 40 years and older living at high altitudes had high BP and prevalence of hypertension with low awareness, treatment, and control. Future studies are needed to clarify the association between BP, altitude, and other possible causes.

Ultrasmooth silver thin film on PEDOT:PSS nucleation layer for extended surface plasmon propagation

Poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) layers are used as the nucleation (seed) layer to reduce surface roughness of the overlying silver (Ag). The technique leads to ultrasmooth Ag thin films with a minimum surface roughness of 0.8 nm. The mechanism contributing to the improvement is explained on the basis of better wetting of Ag on PEDOT:PSS, and properties of the nucleation layer on the aspects of surface energy, surface adhesive force, and surface morphology influencing Ag wetting and growth pattern are being discussed. The surface plasmon resonance (SPR) shows significant improvement, in terms of the Figure of Merits (FOM), as the surface roughness on Ag films is reduced. A lower light scattering and longer plasmon propagation of maximum 15.3 μm are also realized on a smoother Ag surface. The results indicate great potential on the application of combined PEDOT:PSS/Ag structure as an effective and economically feasible design solution for plasmonic and optical metamaterials devices.

Low vitamin D status is associated with physical inactivity, obesity and low vitamin D intake in a large US sample of healthy middle-aged men and women

The aim of this study was to investigate modifiable predictors of vitamin D status in healthy individuals, aged 55-74, and living across the USA. Vitamin D status [serum 25-hydroxyvitamin D (25(OH)D)] was measured along with age and season at blood collection, demographics, anthropometry, physical activity (PA), diet, and other lifestyle factors in 1357 male and 1264 female controls selected from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) cohort. Multivariate linear and logistic regression analyses were used to identify associations with vitamin D status. Three%, 29% and 79% of the population had serum 25(OH)D levels<25, <50 and <80 nmol/L, respectively. The major modifiable predictors of low vitamin D status were low vitamin D dietary and supplement intake, body mass index (BMI) >30 kg/m2, physical inactivity (PA) and low milk and calcium supplement intake. In men, 25(OH)D was determined more by milk intake on cereal and in women, by vitamin D and calcium supplement and menopausal hormone therapy (MHT) use. Thus targeting an increase in vigorous activity and vitamin D and calcium intake and decreasing obesity could be public health interventions independent of sun exposure to improve vitamin D status in middle-aged Americans.

Elevated circulating free fatty acids levels causing pancreatic islet cell dysfunction through oxidative stress

BACKGROUND

Elevated plasma free fatty acids (FFA) concentration is predictive of the conversion from normal glucose tolerance and impaired glucose tolerance to diabetes.

AIMS

To evaluate the effects of prolonged exposure to FFA on basal and glucose-stimulated insulin secretion (GSIS) of pancreatic beta-cell, and to investigate the role of oxidative stress in FFA-induced decrease in beta-cell function.

METHODS

Rats were assigned to 3 groups and underwent 96-h infusions of normal saline (NS), intralipid plus heparin (IH), or intralipid plus heparin and N-acetylcysteine (IH+NAC). The plasma insulin, malonyldialdehyde (MDA), reduced glutathione (GSH), and oxidized glutathione (GSSG) were measured. In vivo intravenous glucose tolerance test (IVGTT) and ex vivo isolated pancreatic tissues perfusion were performed.

RESULTS

In IH group GSIS both in IVGTT and perifused pancreatic tissues were impaired (p<0.05), the GSH/GSSG ratio was declined and MDA levels increased (p<0.05), the volume density score of nuclear factor kappaB and inducible nitric oxide synthase in pancreatic islets were increased compared to the NS group (p<0.01). In IH+NAC group, NAC intervention partly restored the GSH/GSSG ratio and MDA level, and improved FFA induced GSIS impairment.

CONCLUSION

Elevated circulating FFA levels may contribute to causing the abnormalities of pancreatic islet cell function through active oxidative stress and oxidative stress-sensitive signaling pathway, which may play a key role in the development of impaired insulin secretion seen in obese Type 2 diabetes.

Predictors of vitamin D biochemical status in a large sample of middle-aged male smokers in Finland

BACKGROUND/OBJECTIVES

As vitamin D deficiency is considered to be more common in regions with little solar ultraviolet (UV) light in winter, the aim of this study was to analyze predictors of vitamin D status by season within a large sample of male smokers from Finland, a country where there is negligible solar UV light in winter.

SUBJECTS/METHODS

Vitamin D (measured by 25-hydroxyvitamin D (25(OH)D) nmol/l) and other serum constituents were assayed. Measured anthropometry, and self-reported dietary intake and physical activity (PA) were obtained and analyzed using stepwise multiple linear and logistic regression in 2271 middle-aged Finnish male smokers.

RESULTS

In all, 27% of the population in winter and 17% in summer had serum 25(OH)D levels of <25 nmol/l, respectively. In summer, in multiple logistic regression analyses with adjustment for confounding and other predictors, high vitamin D intake (odds ratios (OR) 3.6; 95% confidence interval (CI) 1.5-8.5), some leisure time PA (OR 2.0; 95% CI 1.3-3.1) and having a body mass index (BMI) of >or=21 kg/m(2) compared with <21 kg/m(2) (OR 2.6; 95% CI 1.3-5.0), were associated with 25(OH)D >or=25 nmol/l. In winter, additional modifiable factors were occupational PA (OR 1.6; 95% CI 1.1-2.5) and high fish (OR 3.1; 95% CI 1.7-6.2) or poultry consumption (OR 1.7; 95% CI 1.2-2.5). Predictors from linear regression analyses of continuous levels of 25(OH)D were similar to the logistic regression analyses of 25(OH)D >or=25 nmol/l.

CONCLUSION

In this Finnish sample more vitamin D intake, PA and having a BMI of >or=21 may have important modifiable roles in maintaining an adequate vitamin D status.

Effect of N-cadherin knock-down on invasiveness of esophageal squamous cell carcinoma

e15571

Background: Cell adhesion molecules are of crucial importance in cancer invasion and metastasis. Epithelial to mesenchymal transition, characterized by reduced E-cadherin and increased N-cadherin expression, has been recognized as a feature of aggressive tumors, but the importance of this phenotype has not been settled in esophageal squamous cell carcinoma. Aim: To examine the expressions of N-cadherin and E-cadherin in 62 normal esophageal epithelium specimens, 31 adjacent atypical hyperplasia epithelium specimens and 62 esophageal squamous cell carcinoma specimens, and to investigate the roles of N-cadherin in the invasiveness of esophageal squamous cell carcinoma cell line EC9706 transfected by N-cadherin shRNA.. Methods: PV immunohistochemistry was used to detect the expression pattern of N-cadherin and E-cadherin in 62 normal esophageal epithelium specimens, 31 adjacent atypical hyperplasia epithelium specimens and 62 esophageal squamous cell carcinoma specimens. The invasiveness of esophageal squamous cell carcinoma cell line EC9706 in vitro and in vivo was determined by transwell assay and nude mice experiments after EC9706 was transfected by N-cadherin shRNA. Results: The positive rates of N-cadherin decreased in the sequence of carcinoma, adjacent atypical hyperplasia and normal esophageal tissue, which were 75.8%, 61.3%, 29.0% (P < 0.05), respectively, while those of E-cadherin increased in sequence, which were 40.3%, 71.0% and 95.2% (P < 0.05). The increased expression of N-cadherin and decreased expression of E-cadherin were related to the invasion, differentiation, and lymph node metastasis (P < 0.05). The expression level of N-cadherin decreased in the N- cadherin knocked down cells, and the invasiveness of those cells decreased significantly as well in vitro and in vivo. Conclusions: These results suggest that N-cadherin is an important factor in the invasiveness of esophageal squamous cell carcinoma and N-cadherin may serves as a potential molecular target for biotherapy of esophageal squamous cell carcinoma.

No significant financial relationships to disclose.

Spatial and vertical distribution of polycyclic aromatic hydrocarbons in mangrove sediments

The distribution and historical changes of polycyclic aromatic hydrocarbons (PAHs) contamination in mangrove sediments in Hong Kong SAR were investigated. Surface sediments (2-3 cm) collected from four mangrove swamps exhibited significant spatial variations in concentrations of total PAH (with SigmaPAHs ranging from 56 to 3758 ng g(-1) dry wt), as well as the composition of 16 USEPA priority PAH compounds. Within a small swamp with an area of 0.68 ha, the total PAH concentrations also differed from sampling site to site, indicating that the PAH contamination is localized and confined to a very small area within the same swamp. Discharges from municipal and industrial wastewater, urban runoff, oil leakage from boats and ships, and accidental oil spill are possible sources of the PAH contamination. The sediment depth profiles reveal that the surface sediment layer (0-5 cm) had lower total PAH concentrations than that in the bottom layer (15-20 cm), and PAH composition also changed with the sediment layers. Based on the estimated annual sediment deposition rate in Hong Kong SAR of around 0.4-0.5 cm, the present findings suggest that the PAH contamination was most serious between 1958 and 1979 but started to decline thereafter. Such decline was probably due to changes in petroleum usage in urban areas and a better control of wastewater discharges from 1980 onwards in this region.

Degradation of polycyclic aromatic hydrocarbons by a bacterial consortium enriched from mangrove sediments

The biodegradability of a polycyclic aromatic hydrocarbons (PAHs) mixture consisted of fluorene (Fl), phenanthrene (Phe) and pyrene (Pyr) by a bacterial consortium enriched from mangrove sediments under sediment-free and sediment slurry conditions was investigated. The enriched consortium made up of three bacterial strains, namely Rhodococcus sp., Acinetobacter sp. and Pseudomonas sp., had a good PAH degradation capability with 100% degradation of Fl and Phe in sediment-free liquid medium after 4 weeks of growth. The Fl and Phe degradation percentages in sediment slurry were higher than that in liquid medium. Autochthonous microorganisms in sediments also possessed satisfactory PAH degradation capability and all three PAHs were almost completely degraded after 4 weeks of growth. Bioaugumentation (inoculation of the enriched consortium to sediments) showed a positive effect on PAH biodegradation after 1 week of growth. Complete biodegradation of pyrene took longer time than that for Fl and Phe, indicating the enriched bacterial consortium had preference to utilize low-molecular weight PAHs.

Negative effects of humic acid addition on phytoremediation of pyrene-contaminated sediments by mangrove seedlings

Vegetated (with Kandelia candel seedlings) and non-vegetated mangrove microcosms were employed to remove pyrene from contaminated sediments, and the effects of adding 6.7% humic acid (HA) on such removal were investigated. At the end of 6-month treatment, residual pyrene concentrations in surface sediments (0-2 cm) of the contaminated microcosms reduced from an initial 5.82 to 0.63 microg g(-1) dw, and the reduction was less in HA amended microcosms with the residual pyrene concentration remained at 3.12 microg g(-1) dw. The pyrene removal percentages in microcosms with HA amendment were 29% for surface aerobic sediments and 41% for bottom (anaerobic) sediments, while the respective removal percentages in microcosms without HA amendment were 89% (surface sediments) and 53% (bottom sediments). Microcosms planted with K. candel seedlings had a significantly higher pyrene removal when compared to the non-vegetated ones, and the average removal percentages were 70.9% and 61.4%, respectively. However, when humic acid was added, no significant difference was found between vegetated and non-vegetated microcosms in pyrene removal, both had less than 40% removal, probably because plant growth in humic acid amended contaminated microcosms, in terms of total biomass, was reduced by 50%. Roots of K. candel could accumulate pyrene from contaminated microcosms, and pyrene concentrations in roots harvested from microcosms with and without humic acid addition were 6.01 and 3.46 microg g(-1) dw, respectively. These results suggest that the addition of HA to contaminated sediments decreased the mangrove microcosm's ability to remove pyrene as pyrene was more tightly bound to the organic matter and plant growth was reduced.

Removal of pyrene from contaminated sediments by mangrove microcosms

The potential of mangrove wetland systems to remove pyrene from surface- or bottom-contaminated sediments was investigated by microcosm studies. The performance of two mangrove plant species, Kandelia candel and Bruguiera gymnorrhiza in pyrene removal was also compared. During the six-months experimental period, the growth of both species in the surface-contaminated microcosms was not significantly different from that in the bottom-contaminated ones, and was comparable to the control (without any pyrene contamination). At the end of six-months treatment, pyrene concentrations in contaminated sediments declined from an initial 3 microg g(-1) to less than 0.4 microg g(-1), indicating that pyrene was successfully removed by mangrove microcosms. Around 96.4% and 92.8% pyrene in microcosms planted with K. candel were removed from the surface- and bottom-contaminated sediments, respectively. The removal percentages were slightly lower in microcosms planted with B. gymnorrhiza. Significant accumulation of pyrene in roots was only found in microcosms having bottom-contaminated sediments, and pyrene concentrations were 3.05 microg g(-1) and 4.50 microg g(-1) in roots of K. candel and B. gymnorrhiza, respectively. These values were much higher than that in control microcosms (without pyrene contamination, root pyrene concentrations were 0.27 microg g(-1) for K. candel and 0.34 microg g(-1) for B. gymnorrhiza) and in microcosms with contaminated sediments placed at the surface layer. Nevertheless, the overall contribution of root accumulation and plant uptake to the removal of pyrene from contaminated sediments was insignificant.

Biodegradation of polycyclic aromatic hydrocarbons (PAHs) by microbial consortia enriched from mangrove sediments

Surface sediments from two mangrove swamps in Hong Kong were enriched to obtain PAH-degrading microbial consortia. The consortium from sediments enriched with phenanthrene (Phe) in Ma Wan, a mangrove swamp next to a boat anchorage, was effective in degrading PAH with 96.7% and 89.9% Phe degradation at 0 and 10 ppt salinities, respectively. The Phe-enriched microbial consortium could also use pyrene (Pyr) as the sole carbon source but the degradation was much less (around 15%). On the other hand, the Phe-enriched consortium from sediments in Yi O, a mangrove swamp recently polluted by an oil spill, completely removed Phe and Pyr at both 0 and 10 ppt salinities. This suggests that different consortia were selected in two sediments using the same PAH substrate. Not only sediments, PAH substrate used for enrichment also selected different consortia. The Pyr- and Fla-enriched Yi O consortia only achieved 10.5 and 4.5% Phe degradation, respectively and the corresponding pyrene degradation was 7 and 40%. Among the three PAH compounds, fluoranthene (Fla) was most difficult to degrade, and 21.1, 11.3, and 36.8% Fla were degraded by Phe-, Fla- and Pyr-enriched cultures, respectively.

Congou tea drinking and oesophageal cancer in South China

The study from a large hospital-based case-control for 1248 cases with oesophageal cancer and the same number of controls in South China showed that Congou, a grade of Chinese black tea, may protect against cancers of the oesophagus and reduce the risk of a combination of alcohol drinking and smoking (especially smoking), regardless of temperature when drinking.

Fate of polycyclic aromatic hydrocarbon (PAH) contamination in a mangrove swamp in Hong Kong following an oil spill

The fate of polycyclic aromatic hydrocarbon (PAH) contamination in a mangrove swamp (Yi O) in Hong Kong after an oil spill accident was investigated. The concentrations and profiles of PAHs in surface sediments collected from five quadrats (each of 10 m x 10 m) covering different degrees of oil contamination and the most contaminated mangrove leaves were examined in December 2000 (30 days after the accident) and March 2001 (126 days later). The concentrations of total PAHs in surface sediments ranged from 138 to 2,135 ng g(-1), and PAHs concentrations decreased with time. In the most contaminated sediments, total PAHs dropped from 2,135 (30 days) to 1,196 ng g(-1) (120 days), and the decrease was smaller in less contaminated sediments. The percentage reduction in sediment PAHs over three months (44%) was less significant than that in contaminated leaves (85%), indicating PAH in or on leaves disappeared more rapidly. The PAH profiles were very similar in sediments collected from quadrats Q1 and Q2 with benzo[a]anthracene and pyrene being the most abundant PAH compounds, but were different in the other three quadrats. The proportion of the light molecular weight PAHs to total PAHs increased after three months, especially phenanthrene. Results suggest that physical and photo-chemical weathering (tidal washing and photo-oxidation) of crude oil in surface sediments and on plant leaves were important processes in the first few months after the oil spill. The PAH contamination in Yi O swamp came from both petrogenic and pyrolytic sources. The petrogenic characteristic in the most contaminated sediment was confirmed with high values of phenanthrene to anthracene ratio (>10) and low values of fluoranthene to pyrene ratio (0.3-0.4).

Contamination of polycyclic aromatic hydrocarbons in surface sediments of mangrove swamps

The concentrations of total polycyclic aromatic hydrocarbons (sigmaPAHs) and 15 individual PAH compounds in 20 surface sediments collected from four mangrove swamps in Hong Kong were analysed. sigmaPAH concentrations ranged from 356 to 11,098 ng g(-1) dry weight with mean and median values of 1992 and 1,142 ng g(-1), respectively. These values were significantly higher than those of marine bottom sediments of Hong Kong harbours, suggesting that more PAHs were accumulated in mangrove surface sediments. The concentrations of sigmaPAHs as well as individual PAH compound varied significantly among mangrove swamps. The swamps heavily polluted by livestock and industrial sewage, such as Ho Chung and Mai Po, had much higher concentrations of total PAHs and individual PAH than the other swamps. The PAH profiles were similar among four mangrove swamps, and were dominated by naphthalene (two-ring PAH), fluorene and phenanthrene (three-ring PAH). The mangrove sediments had higher percentages of low-molecular-weight PAHs. These indicated that PAHs in mangrove sediments might originate from oil or sewage contamination (petrogenic input). Ratio values of specific PAH compounds such as phenanthrene/anthracene and fluoranthene/ pyrene, were calculated to evaluate the possible source of PAH contamination in mangrove sediments. These ratios varied among samples, suggesting that mangrove sediments might have a mixed pattern of pyrolytic and petrogenic inputs of PAHs. Sediments collected from Ho Chung mangrove swamp appeared to be more dominated by pyrolytic input while those from Tolo showed strong petrogenic contamination.

Comparison on the effects of three sex hormones on the fetal rat calvarial osteoblasts

17 beta-estradiol (E2), progesterone (P) and testosterone (T) were investigated for their effects on the proliferation and differentiation of primary rat calvarial osteoblasts in vitro. Rat calvarial osteoblasts were cultured with 10(-10) mol/L E2, 10(-9)-10(-6) mol/L P and 10(-10) mol/L T for 20 days. Cell proliferation was determined by 3H-thymidine incorporation and cell counting. Cell differentiation was examined by measuring alkaline phosphatase (ALP) activity, osteocalcin gene expression and production, bone nodule formation in different periods of culture. Our results showed that no effect of three sex hormones was observed on cell proliferation, but, the responses of cell differentiation to the hormones were more or less different. Among these three hormones used in this study, P appeared to have multi-stimulating effect on cell differentiation. Effect of T seemed not so significant as that of P on cell differentiation. Although ALP activity and osteocalcin production were increased significantly by T, it had slight effect on osteocalcin mRNA and bone nodule formation. Besides, E2 did not demonstrate any effect on cell differentiation. It is concluded that the proliferation of rat calvarial osteoblasts was independent of the presence of sex hormones. However, the differentiation of these cells were stimulated in different levels and to different extent either by P or T. P appeared to be a multi-stimulator on differentiation of such cells.

Economic status and occupational correlates of stomach cancer in the rubber industry

Associations between stomach cancer and occupational exposure to rubber remain uncertain, and thus far only a few studies have been carried out to investigate risks of stomach cancer in different jobs in the rubber industry, and confounding of the risk/exposure relationship by non-occupational risk factors, especially by the economic status. This study was aimed to explore these questions. Following a case-cohort design, we used the data of 36 stomach cancer deaths in 1973-95 and a random sample (sub-cohort) of 188 from among 1598 subjects employed in a rubber plant in Shanghai, China. We analysed stomach cancer risks by the economic status, smoking, alcohol consumption, and residential exposure to coal burning-related pollution, etc., and assessed by jobs and years, unadjusted and adjusted. The rate ratios for stomach cancer were found to be 1.70 for 1-19 yr of employment and 1.79 for 20 or more yr of employment in the inner tire tube department. After the economic status was adjusted, the rate ratios were 1.54 and 1.64, respectively. Although the front processing of rubber was also included in our analysis no evidence of any excess risk of stomach cancer was found. Rate ratios adjusted for four job groups were the highest in the low income group. The association followed a pattern of a dose-response relationship--increasing rate ratios correlated with decreasing annual income (statistic trend: chi 2(1) = 8.35, p = 0.004). The data obtained suggest that excess risks of stomach cancer in the rubber workers were mainly related to their economic status and only slightly (some 1.6) to the talc powder exposure. Results of this study fail to provide any statistically significant evidence to support the hypothesis that there was high risk of death from stomach cancer among the rubber workers employed in high dusty departments.

Effects of chronic nicotine treatment on expression of diverse nicotinic acetylcholine receptor subtypes. I. Dose- and time-dependent effects of nicotine treatment

Nicotinic acetylcholine receptors (nAChRs) exist as a diverse family of physiologically important ligand-gated ion channels active in classic, excitatory neurotransmission and perhaps in more novel forms of neurochemical signaling. Because of their critical functional roles centrally and peripherally, nAChRs are ideal targets for the regulation of nervous system function. nAChRs also are targets of nicotine, which acts acutely like acetylcholine to stimulate nAChR function. Here, we report studies using model cell culture systems testing the general hypothesis that more chronic nicotine exposure has unique effects on nAChRs. Chronic nicotine treatment induces increases in numbers of human muscle-type nAChRs containing alpha-1, beta-1, gamma and delta subunits, a human ganglionic nAChR subtype containing alpha-3 and beta-4 subunits and a human ganglionic nAChR containing alpha-7 subunits in intracellular and (except for alpha-7 nAChRs) in cell surface pools. However, the half-maximal potency with which nicotine has these effects differs across these nAChR subtypes, as do rates and magnitudes of the "nicotine-induced nAChR up-regulation." These changes in nAChR numbers are not attributable to either transient or sustained changes in nAChR subunit mRNA levels. Nicotine exposure more potently, more rapidly, and with nAChR-subtype specificity, induces two phases of losses in functional responsiveness of muscle-type nAChRs and alpha-3 beta-4 nAChRs, including a "persistent inactivation" that is distinct from classicly defined "desensitization." Based on these results, we hypothesize that chronic nicotine treatment induces persistent functional inactivation and numerical up-regulation of all nAChR subtypes via distinct post-transcriptional mechanisms and with potencies, at rates and with magnitudes that are nAChR-subtype specific. We also hypothesize that chronic nicotine exposure produces long-lasting changes in nervous system function, at least in part, by disabling rather than activating nicotinic cholinergic signaling.

Near-lossless image compression: minimum-entropy, constrained-error DPCM

A near-lossless image compression scheme is presented. It is essentially a differential pulse code modulation (DPCM) system with a mechanism incorporated to minimize the entropy of the quantized prediction error sequence. With a "near-lossless" criterion of no more than a d gray-level error for each pixel, where d is a small nonnegative integer, trellises describing all allowable quantized prediction error sequences are constructed. A set of "contexts" is defined for the conditioning prediction error model and an algorithm that produces minimum entropy conditioned on the contexts is presented. Finally, experimental results are given.

Effects of steroid exposure on ligand binding and functional activities of diverse nicotinic acetylcholine receptor subtypes

Nicotinic acetylcholine receptors (nAChR) are diverse members of the ligand-gated ion channel superfamily of neurotransmitter receptors and play critical roles in chemical signaling throughout the nervous system. The present study tests whether nAChR are potential targets for steroids. Acute or short-term (5 min) preexposure to steroids such as progesterone (which acts most potently), estradiol, corticosterone, or dexamethasone inhibits function of human muscle-type (alpha 1 beta 1 gamma delta) or ganglionic (alpha 3 beta 4) nAChR measured using 86Rb+ efflux assays in TE671/RD clonal or SH-SY5Y neuroblastoma cells. Absolute (high nanomolar to intermediate micromolar range) and rank-order potencies for steroid-mediated functional inhibition are similar across nAChR subtypes but differ for some steroid derivatives. At concentrations that produce blockade of nAChR function, steroids do not affect binding of radioligands such as 125I-labeled alpha-bungarotoxin or [3H] acetylcholine to muscle-type or ganglionic nAChR or to neuronal toxin-binding nAChR that contain alpha 7 subunits (alpha 7-nAChR). Steroid-mediated blockade of nAChR function is insurmountable by increasing agonist concentrations, and cell-impermeant progesterone:bovine serum albumin conjugates have full potency as inhibitors of ganglionic or muscle-type nAChR function. Chronic (48 h) exposure to progesterone or estradiol, but not the other steroids, also produces blockade of nAChR function, without significant effects on numbers of nAChR radioligand-binding sites. Collectively, these results suggest that steroids act noncompetitively at extracellular sites to inhibit nAChR function with unique potencies for different steroid-nAChR subtype combinations. Thus, nAChR could be among the targets mediating physiologically relevant effects of steroid action in the nervous system.

Polyvalent and monoclonal antibodies identify major immunogenic proteins specific for human herpesvirus 7-infected cells and have weak cross-reactivity with human herpesvirus 6

Hyperimmune rabbit and mouse sera raised to human herpesvirus 7 (HHV-7)-infected cells and an immune human serum identified 20[35S]methionine-[35S]cysteine-labelled proteins specific for HHV-7-infected cord blood mononuclear cells, ranging in apparent M(r) from 136K to 30K. The major proteins had apparent M(r) values of 121K, 100K, 87K, 85K, 60K, 51K, 46K, 42K, 40K and 36K. The human serum also identified seven [3H]glucosamine-labelled glycoproteins, with apparent M(r) values of 100K, 89K, 82K, 67K, 63K, 53K and 41K. Four monoclonal antibodies (MAbs) specific for HHV-7-infected cells were derived. Two reacted with a family of five antigenically related polypeptides (87K, 85K, 70K, 61K and 57K in apparent M(r)), designated as the p85 complex. Two reacted with 121K and 51K M(r) proteins designated as p121 and p51, respectively. Human sera react with high frequency with the p85 complex and to a lesser extent with p121; hence these two proteins appear to be immunodominant for both humans and laboratory animals. The hyperimmune mouse serum and some of the MAbs showed some cross-reactivity with HHV-6A(U1102)- and 6B(Z29)-infected cells. The implications of cross-reactivity with respect to the human immune response to HHV-6 and -7 infections and prevalence analyses are discussed.

The phosphonic acid analog of phosphatidylglycerol phosphate: influence on Escherichia coli growth and physiology

At 20 microM, rac-3,4-dihydroxybutyl-1-phosphonate (DBP) has only a slight bacteriostatic effect on Escherichia coli. However, cells lose viability when the medium also contains either 20 mM magnesium or calcium ions. Magnesium ions stimulate the incorporation of DBP into (1,2-diacyl)-sn-glycerol-D-4'-phosphoryloxy-3'-hydroxybutyl-1'-pho sphonate, the phosphonate analog of phosphatidylglycerol phosphate. Much higher DBP concentrations are needed to block the growth of a pgsA3 mutant than to block the growth of an isogenic wild-type strain. The DBP-treated pgsA mutant also has a much higher survival rate when stored in the cold than does the DBP-treated wild-type strain. Furthermore, the pgsA3 mutant grows normally in the presence of DBP and magnesium ions. Treatment with DBP and magnesium ions does not appear to disrupt the cell's inner or outer membranes. However, it does block macromolecular and phosphoglyceride synthesis. A combination of 20 microM rac-DBP and 0.5 mM spermidine or 0.125 mM spermine is bacteriostatic. These studies indicate that the PGP analog contributes to DBP's bacteriostatic effect when the growth medium contains low concentrations of magnesium or calcium ions and is responsible for its bactericidal effect when the medium contains high concentrations of these ions.

The identification of female sandflies of the subgenus Larroussius by the morphology of the spermathecal ducts

The complete spermathecae of 13 species of Larroussius were dissected and examined. The base of the duct of 4 species (aculeatus, guggisbergi, tobbi, wui) is bell-shaped: they are easily distinguished by differences in shape. Five other species (perniciosus, pedifer, longicuspis, perfiliewi, galilaeus) have lateral structures at the base of the duct: slight differences between perniciosus, pedifer and longicuspis distinguish these species: the structures of perfiliewi and galilaeus are the same. Species of a third group (neglectus, syriacus) have a common duct with no lateral structures: they are distinguishable by minor differences. Two species (ariasi, orientalis) from a fourth group with expanded distal parts of the duct; the size and shape of the expanded parts easily separates the species. The study shows a great variation in the morphology of the base of the spermathecal ducts of Larroussius and confirms the value of this feature in identifying otherwise indistinguishable females of the subgenus.

Determination of estriol and creatinine in urine by high performance liquid chromatography

A quantitative method for the determination of estriol (E3) and creatinine (C) in random urine by high performance liquid chromatography is described. The mobile phase was a mixed solution of methanol and phosphate buffer (0.025 M, pH 6.5) and the detection wavelength was at 205 nm. The method was simple, rapid and accurate. The OCV for E3 and C using this method were 1.7-3.4% and 2.2-2.5%, respectively. The RCV for E3 and C were 6.2-7.0% and 4.5-6.9%, respectively. The recoveries were 87-104% for E3 and 98-103% for C, respectively. The method has been used for clinical determinations.