Web-based distance learning for nurse education: a systematic review

BACKGROUND

Web-based distance learning is considered a promising approach to replace or supplement conventional nursing instruction. However, no systematic review has been seen to explore the effect of web-based distance education in nursing.

AIM

To examine the efficacy of the web-based distance education for nursing students and employed nurses.

METHODS

A systematic review of randomized controlled studies was undertaken. Multiple search strategies were performed in PubMed and Embase until July 2012. Two reviewers independently selected trials, conducted quality critical appraisal, and extracted the data from the included studies.

RESULTS

Nine randomized controlled trials met inclusion criteria, among which five studies were rated as A quality level, and the other four studies as B quality level. The results showed that web-based distance learning has produced equivalent or better effects in knowledge acquisition. For nursing skill performance, four studies revealed a positive role for the new teaching mode, and one study showed a negative viewpoint. This review also demonstrated that participants generally accepted web-based education with high satisfaction rates. Two studies reported a more positive trend for self-efficacy in performing nursing skills in the experiment group compared with control group. Some negative feedbacks were also expressed.

CONCLUSION

Web-based education has encouraging effects in improving both participants' knowledge and skills performance, and in enhancing self-efficacy in performing nursing skills, with a high satisfaction rate expressed by participants. More rigorous experimental studies are advocated.

Effect of FK506 in reducing scar formation by inducing fibroblast apoptosis after sciatic nerve injury in rats

We previously demonstrated that FK506, a generally applied immunosuppressant in organ transplantation, could promote peripheral nerve regeneration through reducing scar formation. However, little is known about how FK506 reduces scar formation. Herein we investigated the influence of FK506 on fibroblast proliferation and its correlation with scar formation after sciatic nerve injury in rats, and further explored the effect of FK506 on fibroblast proliferation and apoptosis in vitro. Masson staining and immunohistochemistry revealed that scar area and fibroblast number in the nerve anastomosis of sciatic nerve-injured rats were significantly reduced after FK506 administration. The scar area had a significant positive correlation with the fibroblast number, as detected by linear correlation analysis. CCK-8 assay and flow cytometry indicated that FK506 also inhibited proliferation and induced apoptosis of fibroblasts in vitro. It was primarily phosphorylation of JNK and ERK that were activated during the apoptosis of fibroblast. Pretreatment of cells with JNK inhibitor, SP600125, or ERK inhibitor, PD98059, could inhibit FK506-induced fibroblast apoptosis, respectively. Moreover, simultaneous application of both inhibitors had additive roles in cell protection from apoptosis. These results suggest that FK506-induced fibroblast apoptosis contributes to the suppression of fibroblast proliferation and then results in the reduction of scar formation in sciatic nerve-injured rat, and that JNK and ERK are involved in FK506-induced fibroblast apoptosis.

The expanding burden of cardiometabolic risk in China: the China Health and Nutrition Survey

China faces a major increase in cardiovascular disease, yet there is limited population-based data on risk factors, particularly in children. Fasting blood samples, anthropometry and blood pressure were collected on 9,244 children and adults aged ≥7 years in late 2009 as part of the national China Health and Nutrition Survey. Prevalent overweight, elevated blood pressure, and cardiometabolic risk factors: glucose, HbA1c, triglycerides (TG), total cholesterol (TC), high- and low-density lipoprotein cholesterol (HDL-C and LDL-C), and C-reactive protein (CRP) are presented. We found that 11% of Chinese children and 30% of Chinese adults are overweight. Rates of diabetes, dyslipidaemia, hypertension and inflammation are high and increased with age and were associated with urbanization. Approximately 42% of children have at least one of the following: pre-diabetes or diabetes, hypertension, high TC, LDL-C, TG, and CRP and low HDL-C, as do 70% men and 60% women aged 18-40 years and >90% of men and women ≥60 years. In sum, the HbA1c findings suggest that as many as 27.7 million Chinese children and 334 million Chinese adults may be pre-diabetic or diabetic. The high prevalence in less urban areas and across all income levels suggests that cardiometabolic risk is pervasive across rural and urban China.

The protective effect of curcumin on Aβ induced aberrant cell cycle reentry on primary cultured rat cortical neurons

OBJECTIVES

Alzheimer's disease (AD) is a neurodegenerative disorder marked by progressive loss of memory and impairment of cognitive ability. One current hypothesis for AD pathogenesis is that neuronal death is linked to aberrant cell-cycle re-entry. In AD, neurons have been shown to enter the cell cycle inappropriately without the ability to complete it fully and the aberrant re-entry leads to its death. Curcumin has been reported as having a neural protective effect on the AD model, and could modulate the proliferation of tumor cells through the regulation of cyclin D1 and c-myc cell signaling pathways. In this study, we first observed the protective action of curcumin on Abeta-induced neuron damage, and then investigated whether this protective effect was a result of the inhibition of cell cycle advance.

MATERIALS AND METHODS

We used MTT assay and TUNEL assay to observe the effect of curcumin on Abeta-induced neuron death, and then examined the activated caspase-3 protein level to further confirm the protective effect of curcumin against Abeta-induced neuron toxicity. Next, we further investigate whether the inhibition of cell cycle reentry was mediated by the therapeutic effect of curcumin on Abeta induced primary cultured neuron damage by Brdu label assay and western blot assay.

RESULTS

The results showed that administration of curcumin (1-10 microM) could inhibit Abeta25-35 (40 microg/ml) induced primary cultured rat cortical neuron death, down-regulating activated caspase-3 protein expression. Furthermore, treatment with curcumin could inhibit abnormal activated cyclin D1 protein level, and decrease the Brdu positive cells in proportion to the Abeta25-35 treatment neurons.

CONCLUSIONS

All the results suggest that curcumin has a protective effect against Abeta-induced toxicity in cultured rat cortical neurons, the inhibition of cell cycle re-entry at least partly mediating the therapeutic effect of curcumin in the AD model in vitro.

Effects of interval between fusion and activation, cytochalasin B treatment, and number of transferred embryos, on cloning efficiency in goats

To improve the efficiency of somatic cell nuclear transfer (SCNT) in goats, we evaluated the effects of the interval between fusion and activation (1 to 5 h), cytochalasin B (CB) treatment after electrofusion, and the number of transferred embryos on the in vivo and in vitro development of cloned caprine embryos. The majority of the reconstructed embryos had condensed chromosomes and metaphase-like chromosomes at 2 and 3 h after fusion; cleavage and blastocyst rates from those two groups were higher (P < 0.05) than those of embryos activated 1, 4, or 5 h after fusion. Treatment with CB between fusion and activation improved in vitro and in vivo development of nuclear transfer (NT) goat embryos by reducing the fragmentation rate (P < 0.05). Although there were no significant differences in NT efficiency, pregnancy rate and kids born per recipient were increased by transfer of 20 or 30 embryos per recipient compared with 10 embryos. We concluded that CB treatment for 2 to 3 h between fusion and activation was an efficient method for generating cloned goats by somatic cell NT. In addition, increasing the number of embryos transferred to each recipient resulted in more live offspring from fewer recipients.

Evaluation of patient self-management outcomes in health care: a systematic review

BACKGROUND

The importance of self-management and its intervention for improving the ability and skill of self-management has been discussed in literatures. It is, however, unclear how to choose the fitted, objective and accurate evaluation system when assessing the outcome.

AIM

The aim of this article was to establish a general evaluation system for skill and ability of self-management in chronic diseases through systematic review on different evaluation indicators and scales.

METHOD

A systematic search of six electronic databases was conducted. Two authors independently reviewed each qualified study for relevance and significance. Subsequently, main evaluation indicators and scales were identified and categorized into themes and sub-themes.

RESULTS

Nineteen articles were identified in this review. Among them, six main evaluation indicators of self-management, including frequently used scales, were extracted and tabulated. Self-efficacy, health behaviour/attitude, health status, health service utilization, quality of life and psychological indicators were the main indicators in evaluating self-management outcome, and they could be used alone or in combination flexibly according to the different goals of programmes.

CONCLUSION

Accurate evaluation of skill and ability of self-management is crucial not only in baseline data collection but also in proving the effectiveness of intervention. The outcomes of this study provide future researchers or caregivers with a better understanding and a series of good choices in self-management outcome evaluation.

Progress in the remediation of hazardous heavy metal-polluted soils by natural zeolite

Hazardous heavy metal pollution of soils is an increasingly urgent problem all over the world. The zeolite as a natural amendment has been studied extensively for the remediation of hazardous heavy metal-polluted soils with recycling. But its theory and application dose are not fully clear. This paper reviews the related aspects of theory and application progress for the remediation of hazardous heavy metal-polluted soils by natural zeolite, with special emphasis on single/co-remediation. Based on the comments on hazardous heavy metal behavior characteristics in leaching and rhizosphere and remediation with zeolite for heavy metal-polluted soils, it indicated that the research of rhizosphere should be strengthened. Theory of remediation with natural zeolite could make breakthroughs due to the investigation on synthetic zeolite. Co-remediation with natural zeolite may be applied and studied with more prospect and sustainable recycling.

Co-remediation of the lead-polluted garden soil by exogenous natural zeolite and humic acids

The current study reported the co-remediation effect on the lead-polluted garden soil by zeolite and humic acids (HA), which was from comparing with the remediation of single zeolite in term of the lead fraction of sequential extraction in the soil and the distribution of lead in different parts of rape. Mixed treatment (zeolite and HA) and single treatment (zeolite) were, respectively, applied to the artificially polluted garden soil to examine the difference of their remediation effects in pot experiment. Results indicated that the co-remediation led to significantly greater (p<0.01) reduction in the lead concentration in plants than by singly adding to zeolite. The co-application of zeolite and HA reduced the available fraction of lead compounds, but slightly increased (p<0.01) the water-soluble fraction of lead compounds in the garden soil, compared with the application of single zeolite, especially in the severe lead-polluted soil (> or =1000 mg kg(-1)). This method might be an efficient way to remediate the lead-polluted soils on a large scale, although zeolite is a kind of hazardous material.

Influence of rumen escape starch on pancreatic exocrine secretion of goats

The objective of the experiment was to evaluate the effect of rumen escape starch (RES), accomplished by altering dietary starch concentrations on pancreatic exocrine secretion of goats. Four goats (36.8 +/- 3.2 kg) with common bile duct re-entrant and duodenal catheters were used in a 4 x 4 Latin square. Goats were fed diets containing 20%, 30%, 40% and 50% starch. Periods consisted of 10 day adaptation followed by 3 day of sample collection. Juice was collected in 1-h fractions continuously for 72 h. Total juice secreted was recorded, and 3% sub samples were retained to form a composite sample. The remaining fluid was returned to the duodenum. Juice composite samples were analyzed for activities of alpha-amylase, trypsin, chymotrypsin and lipase. Secretion of pancreatic alpha-amylase was lower (p < 0.05) when comparing lambs fed 20% starch diet with 30%, 40% and 50% starch diets. Lipase secretion was greater (p < 0.05) in lambs fed 40% starch diet compared with the other diets. Total secretion of juice, trypsin and chymotrypin was not affected (p > 0.05) by dietary starch concentration. Rumen escape starch increased with increasing dietary starch concentration (p < 0.05). Regression analysis showed that increasing RES results in a quadratic increase (p < 0.05) in pancreatic alpha-amylase and lipase secretion, and the secretion of alpha-amylase and lipase is maximum when RES is 113 and 83 g/day respectively. These results suggest that optimal RES for pancreatic secretion of alpha-amylase and lipase is 80-110 g/day in adult goats.

First measurement of the neutron beta asymmetry with ultracold neutrons

We report the first measurement of an angular correlation parameter in neutron beta decay using polarized ultracold neutrons (UCN). We utilize UCN with energies below about 200 neV, which we guide and store for approximately 30 s in a Cu decay volume. The interaction of the neutron magnetic dipole moment with a static 7 T field external to the decay volume provides a 420 neV potential energy barrier to the spin state parallel to the field, polarizing the UCN before they pass through an adiabatic fast passage spin flipper and enter a decay volume, situated within a 1 T field in a 2x2pi solenoidal spectrometer. We determine a value for the beta-asymmetry parameter A_{0}=-0.1138+/-0.0046+/-0.0021.

Cross-sectional comparison of physical activity and inactivity patterns in Chinese and Filipino youth

BACKGROUND

To compare and contrast youth physical activity (PA) and inactivity patterns in two developing Asian countries: the Philippines and China.

METHODS

Comparative analysis of 1997-1999 Cebu Longitudinal Health and Nutrition Survey and the 1997 China Health and Nutrition Survey, large-scale surveys that included questions on type, frequency and duration of: commuting mode to school, sports/exercise in and outside of school, select sedentary activities and chores.

RESULTS

Filipino data included 760 males and 872 females aged 14-16 years. The comparable Chinese sample consisted of 202 males and 197 females. Active commuting is proportionately high in both countries (70-71% in the Philippines vs. 77-90% in China), although commuting by bicycling is rare in the Philippines (<1%) vs. China ( approximately 35%). Patterns of school sport/exercise participation differ between countries by gender; more Filipino males report school sport/exercise than females (63 vs. 49%) vs. China, where more females participate than males (75 vs. 69%). Sport/exercise outside of school is proportionately low (6-12%) for youth from both countries with a single exception: 74% of Filipino males participate in extra-curricular sport/exercise. Although a higher percentage of Filipino youth report watching television >4 h/day (<10%) vs. Chinese youth (<1%), both are lower than comparable US reports.

CONCLUSION

In the Philippines, continued modernization augurs a decrease in local primary PA sources (chores and active commuting). In China, where youth already are not expected to perform chores, shifts to more passive commuting modes (i.e. increased motorized transportation) are anticipated.

Studies on the encapsulation of oxymatrine into liposomes by ethanol injection and pH gradient method

Oxymatrine is the major active alkaloid constituent extracted from traditional Chinese herb medicine Sophora flavescens Ait (Kushen) and Sophora alopecuroides (Kudouzi). In recent years, oxymatrine had been found to posses remarkable anti-hepatic activity and has been used for treating hepatitis B in clinical therapy in China. In this study, we attempted to entrap oxymatrine into liposomes to facilitate the delivery of oxymatrine to the liver and enhance the therapeutic efficiency for hepatitis. Preformulation investigation was performed to obtain the drug physicochemical properties such as solubility, pKa, and logP for rational liposomes preparation design. Liposomes were prepared with soybean lecithin by ethanol injection and pH gradient loading methods. At the same time the factors affecting the entrapment efficiencies were investigated and compared. Ethanol injection method yielded liposomes with entrapment efficiency less than 20%. The lipid composition and aqueous medium had some effects on entrapment efficiency. However, liposomes could be produced with entrapment efficiency above 50% by pH gradient method. The internal pH buffer capacity, the lipid composition, and drug-to-lipid ratio greatly influenced the entrapment efficiency, while the incubation temperature had almost no effect on entrapment efficiency in the active loading procedure.

Measuring the full economic costs of diet, physical activity and obesity-related chronic diseases

Most studies that have focused on the costs of obesity have ignored the direct effects of obesity-related patterns of diet and physical activity. This study reviews the full effects of each component--poor dietary and physical activity patterns and obesity--on morbidity, mortality and productivity. The direct healthcare costs are based on a review of the effects of these factors on key diseases and the related medical care costs of each disease. The indirect costs on reduced disability, mortality and sickness during the period of active labour force participation prior to retirement are also examined. A case study is prepared for China to provide some guidance in the utilization of this review for economic analysis of obesity. The case study shows that the indirect costs are often far more important than the direct medical care costs. The Chinese case study found that the indirect effects of obesity and obesity-related dietary and physical activity patterns range between 3.58% and 8.73% of gross national product (GNP) in 2000 and 2025 respectively.

Trends in the distribution of body mass index among Chinese adults, aged 20-45 years (1989-2000)

OBJECTIVE

To describe body mass index (BMI, in kg/m(2)) distribution patterns and trends among Chinese adults, aged 20-45 years (1989-2000).

DESIGN

A descriptive, population-based study of BMI change.

SETTING

Chinese provinces (eight in 1989 and 1997; nine in 2000), representative of the household-based surveys (the China Health and Nutrition Survey, 1989-2000) using multistage, random cluster sampling, supplemented with annual household consumption survey data of the State Statistical Bureau (SSB).

SUBJECTS

A total of 4527, 4507 and 4046 adults, aged 20-45 years, in 1989, 1997 and 2000, respectively.

MEASUREMENTS

BMI (underweight: BMI<18.5 kg/m(2) and overweight: BMI>/=25 kg/m(2)). Percentile curves for BMI in 1989 and 2000 were constructed by gender and age using the LMS (lambda, mu, sigma) method.

RESULTS

Compared with 1989, the 2000 BMI distribution curves flattened at higher levels of BMI (men and women). There was a 13.7% increase in the proportion of men and a 7.9% increase of women who were overweight or obese with a resulting greater change in the annualized prevalence rate for men. This increase in the prevalence of overweight and obesity was far greater than the decrease (2.1% for men; 2.2% for women) in that of underweight. Age-gender-specific percentile curves showed BMI increases mainly among women, aged 35-45 years, and among men at all age groups.

CONCLUSIONS

Chinese BMI dynamics show much greater rates of change among men, aged 20-45 years, than among women, with the increase among women concentrated between ages 35 and 45 years. These changes portend large shifts in other diet-related non-communicable diseases in China over the following decades. Controlling the increasing trends of BMI, especially in men, is an important public health problem facing China.

Enhanced oral bioavailability of breviscapine after encapsulation in a liposomal formulation

This report firstly describes the pharmacokinetic study of liposomal breviscapine (LB) after oral administration in rats. The mean Cmax and AUC(0-->t) of LB were 3.3 and 3.1-fold higher than those of breviscapine solution (BS). The oral absorption of breviscapine was significantly increased after encapsulation in the liposomal formulation.

Endogenous indole-3-acetic acid and ethylene evolution in tilted Metasequoia glyptostroboides stems in relation to compression-wood formation

Eight-year-old Metasequoia glyptostroboides seedlings were tilted at a 45 degrees angle to induce compression-wood formation on the lower side of the stems. After 2 weeks of treatment, half of the seedlings were sampled and the remaining half were tilted to the opposite orientation to exchange the upper and lower sides and were kept for 2 more weeks until sampled. Cambium-emitted ethylene was analyzed by gas chromatography with flame-ionization detection. Endogenous indole-3-acetic acid (IAA) was measured by gas chromatography-mass spectrometry. Tracheid production and compression-wood formation were determined by light microscopy. Anatomical studies showed that tracheid production was promoted and compression-wood tracheids always developed on the gravitationally lower side of tilted stems in both the original tilting and the subsequent reverse-tilting periods. These were accompanied by an increase in IAA content in and an accelerated ethylene-evolution rate from the cambial region of the same side.

Histological measurement of human retinal thickness

The fresh eye balls from the accidental death adults were placed on low temperature slicer to cut into slices. The fresh sections was subjected to the direct measurement of retinal thickness by using CMIAS multi-function real color pathologic imaging analysis system. The results showed that in the total of 6 eye balls measured, the mean retinal thickness was 310.92 +/- 34.14 microns. It was concluded that it was simple and had high confidence for the fresh eye ball low temperature frozen sections to directly measure the retinal thickness, which provided a histological method for the measurement of retinal thickness and the reference of retinal thickness of Chinese adults.

Physical activity and inactivity in Chinese school-aged youth: the China Health and Nutrition Survey

OBJECTIVE

To describe physical activity (PA) and inactivity levels and patterns in Chinese school children (aged 6-18 y).

DESIGN

PA and inactivity were assessed in a youth cohort enrolled in the China Health and Nutrition Survey (CHNS) in 1997.

SUBJECTS

A total of 1423 males (11.5+/-3.2 y) and 1252 females (11.5+/-3.3 y).

MEASUREMENTS

PA and inactivity were assessed by self-reported usual activity (questionnaire). Children under 10 y were assisted by parents.

RESULTS

Approximately 84% of Chinese youth actively commute to school for a median of 100-150 min/week. A total of 72% engage in in-school moderate/vigorous (MOD/VIG) PA for a median of 90-110 min/week. Relatively few children ( approximately 8%) participate in any MOD/VIG PA outside of school. A total of 72% engage in study-related activities outside of school for a median of 420 min/week. Only 8% of Chinese school children, regardless of gender, watch television > or =2 h/day; less than 1% watch > or =4 h/day. Chores related to housework are not a part of life for Chinese school children; fewer than 20% performed these tasks.

CONCLUSION

Chinese youth are unique compared to those in other developing countries because they do not perform household chores. Instead, they are under pressure to achieve scholastically. Participation in MOD/VIG PA outside of school is almost nonexistent. Current television watching habits are relatively low compared to developed countries and walking/biking is a common form of commuting. The descriptive analysis herein represents the foundation upon which future longitudinal studies of PA in this population will be based.

[Use of transcranial Doppler in monitoring cerebral blood flow velocity during peri-operation]

Transcranial Doppler was used to monitor 45 patients' middle cerebral artery blood flow velocity during anesthesia and cardiopulmonary bypass. The result was that the change in middle cerebral artery blood flow velocity was in correspondence with cerebral blood flow. This paper suggests that transcranial Doppler is a simple and practical instrument for monitoring cerebral blood flow.

Synthesis and reactivity of the monocarbon molybdenacarborane anion [1,2-mu-NHBu(t)-2,2,2-(CO)(3)-closo-2,1-MoCB(10)H(10)](-)

The reagent Li[7-NHBu(t)()-nido-7-CB(10)H(12)] reacts with [Mo(CO)(6)] in NCMe at reflux temperatures, followed by addition of [N(PPh(3))(2)]Cl, to give [N(PPh(3))(2)][1,2-mu-NHBu(t)-2,2,2-(CO)(3)-closo-2,1-MoCB(10)H(10)] (1). The tungsten (2) and chromium (3) analogues were similarly obtained, but the latter is unstable and was isolated in low yield. An X-ray diffraction study of 2 confirmed that the exo-polyhedral NHBu(t) group forms a bridge between the cage-carbon atom and the tungsten. For 1, this intramolecular donor bond is lifted on protonation in the presence of donor molecules L (CO, PPh(3), PMe(3), PEt(3), PMe(2)Ph) when zwitterionic complexes [1-NH(2)Bu(t)()-2,2,2-(CO)(3)-2-L-closo-2,1-MoCB(10)H(10)] (4) are formed. In contrast, protonation with HCl gives a salt [N(PPh(3))(2)][1-NH(2)Bu(t)()-2,2,2-(CO)(3)-2-Cl-closo-2,1-MoCB(10)H(10)] (5). Complex 1 in CH(2)Cl(2) with CNBu(t) is oxidized by iodine, affording [1,2-mu-NHBu(t)()-2,2,2-(CNBu(t)())(3)-2-I-closo-2,1-MoCB(10)H(10)] (6a). Treatment of 1 with [CuCl(PPh(3))](4) in the presence of Tl[PF(6)] yields the bimetallic compound [exo-[Cu(PPh(3))]-1,2-mu-NHBu(t)-2,2,2-(CO)(3)-closo-2,1-MoCB(10)H(10)] (8), whereas reaction with [AuCl(PPh(3))] and Tl[PF(6)] affords a mixture of [1,2-mu-NHBu(t)-2-[Au(PPh(3))]-2,2,2-(CO)(3)-closo-2,1-MoCB(10)H(10)] (9) and [Au(PPh(3))(2)][2,2'-mu-Au-[1,2-mu-NHBu(t)-2,2,2-(CO)(3)-closo-2,1-MoCB(1)(0)H(10)](2)] (10a). In solution, 9 disproportionates, giving 10a. The [N(PPh(3))(2)](+) salt (10b) is readily prepared by treating 1 with [AuCl(THT)] (THT = tetrahydrothiophene) and Tl[PF(6)], and its structure was determined by X-ray diffraction.

Vaccinia virus telomeres: interaction with the viral I1, I6, and K4 proteins

The 192-kb linear DNA genome of vaccinia virus has covalently closed hairpin termini that are extremely AT rich and contain 12 extrahelical bases. Vaccinia virus telomeres have previously been implicated in the initiation of viral genome replication; therefore, we sought to determine whether the telomeres form specific protein-DNA complexes. Using an electrophoretic mobility shift assay, we found that extracts prepared from virions and from the cytoplasm of infected cells contain telomere binding activity. Four shifted complexes were detected using hairpin probes representing the viral termini, two of which represent an interaction with the "flip" isoform and two with the "flop" isoform. All of the specificity for protein binding lies within the terminal 65-bp hairpin sequence. Viral hairpins lacking extrahelical bases cannot form the shifted complexes, suggesting that DNA structure is crucial for complex formation. Using an affinity purification protocol, we purified the proteins responsible for hairpin-protein complex formation. The vaccinia virus I1 protein was identified as being necessary and sufficient for the formation of the upper doublet of shifted complexes, and the vaccinia virus I6 protein was shown to form the lower doublet of shifted complexes. Competition and challenge experiments confirmed that the previously uncharacterized I6 protein binds tightly and with great specificity to the hairpin form of the viral telomeric sequence. Incubation of viral hairpins with extracts from infected cells also generates a smaller DNA fragment that is likely to reflect specific nicking at the apex of the hairpin; we show that the vaccinia virus K4 protein is necessary and sufficient for this reaction. We hypothesize that these telomere binding proteins may play a role in the initiation of vaccinia virus genome replication and/or genome encapsidation.

[Distributions of body mass index of Chinese adults]

Based on the Third China National Nutrition Survey conducted in 1992, the distribution of body mass index (BMI) in 44,485 adults aged 20-60 y was analyzed, and the cutoff points of BMI for overweight and obesity were also explored. The results showed that the BMI of Chinese adults was in logarithmic normal distribution. The average BMI of this population was 22.1 +/- 3.1. The 50th, 85th and 95th percentiles of BMI were 21.6, 24.9 and 27.4 kg/m2 respectively. The 85th percentile of BMI was much closer to the BMI cutoff points for overweight recommended by WHO, but the 95th percentile was much lower than WHO's cutoff points for obesity. The distribution of BMI based on age, gender and urban/rural areas was different and with statistical significance. It is considered that age and gender should be taken into account while setting up BMI cutoff points for the overweight and obesity of a population, as well as considering the relationships among BMI and morbidity and mortality, body fat composition, and some blood biochemical indexes.

The neuroprotective agent ebselen modifies NMDA receptor function via the redox modulatory site

Ebselen is a seleno-organic compound currently in clinical trials for the treatment of ischemic stroke and subarachnoid hemorrhage. Its putative mode of action as a neuroprotectant is via cyclical reduction and oxidation reactions, in a manner akin to glutathione peroxidase. For this reason, we have investigated the effects of ebselen on the redox-sensitive NMDA receptor. We have found that ebselen readily reversed dithiothreitol (DTT) potentiation of NMDA-mediated currents in cultured neurons and in Chinese hamster ovary (CHO) cells expressing wild-type NMDA NR1/NR2B receptors. In contrast, ebselen was unable to modulate NMDA-induced currents in neurons previously exposed to the thiol oxidant 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), or in CHO cells expressing a mutant receptor lacking the NR1 redox modulatory site, suggesting that ebselen oxidizes the NMDA receptor via this site. In addition, ebselen was substantially less effective in modifying NMDA responses in neurons exposed to alkylating agent N-ethylmaleimide (NEM) following DTT treatment. Ebselen also reversed DTT block of carbachol-mediated currents in Cos-7 cells expressing the alpha(2)beta delta epsilon subunits of the acetylcholine receptor, an additional redox-sensitive ion channel. Ebselen was observed to significantly increase cell viability following a 30-min NMDA exposure in cultured neurons. In contrast, other more typical antioxidant compounds did not afford neuroprotection in a similar paradigm. We conclude that ebselen may be neuroprotective in part due to its actions as a modulator of the NMDA receptor redox modulatory site.

[Transition of dietary pattern in China]

The implications of dietary transition in China during the past 50 years were investigated. Data were collected from the representative national surveys, China Health and Nutrition Survey (1989-1997), China National Nutrition Survey (1982 and 1992), the Annual Household Consumption Surveys of the State Statistic Bureau and the Annual Death Report of China. In the early part of the major economic transformation, cereal intake increased before 1985 and decreased thereafter. There was also a long-term reduction of vegetable consumption, which has stabilized now. Intakes of animal foods increased slowly before 1979 and more quickly after the economic reforms occurred. The total energy intake has reduced, as energy expenditure has, large changes in the composition of energy have occurred. The proportion of energy from fat increased quickly and reached 27.3% in average and 32.8% in urban residents in 1997. More than one third of all Chinese adults and 58.4% of adults in urban areas consuming over 30% of their energy from fat. These changes resulted in rapid increases the prevalence of overweight and obesity and dietary-related chronic non-communicable diseases in urban residents. The traditional Chinese diet is shifting towards a diet with high fat, high energy density and low dietary fiber. The Chinese diets have entered into a new stage of transition.

Measurement of CP-violating asymmetries in B0 decays to CP eigenstates

We present measurements of time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurement uses a data sample of 23x10(6) Upsilon(4S)-->BbarB decays collected by the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we find events in which one neutral B meson is fully reconstructed in a CP eigenstate containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the standard model is proportional to sin2beta, is derived from the decay time distributions in such events. The result is sin2beta = 0.34+/-0.20 (stat)+/-0.05 (syst).

Structural and mechanistic investigation of 3-deoxy-D-manno-octulosonate-8-phosphate synthase by solid-state REDOR NMR

15N¿(31)P¿ REDOR NMR experiments were applied to lyophilized binary complexes of 3-deoxy-D-manno-2-octulosonate-8-phosphate synthase (KDO8PS), with each of its natural substrates, phosphoenolpyruvate (PEP) and arabinose-5-phsophate (A5P), and with a mechanism-based inhibitor (K(i) = 0.4 microM), directly characterizing the active site basic residues involved in the binding of their carboxylate and phosphate moieties. KDO8PS was labeled uniformly with (15)N or [eta-(15)N(2)]Arg, and the ligands were selectively labeled with (13)C and (15)N. The NMR data established that PEP is bound by KDO8PS via a preserved set of structurally rigid and chemically unique Arg and Lys residues, with 5 A (upper limit) between epsilon-(15)N of this Lys and (31)P of PEP. A5P is bound in its cyclic forms to KDO8PS via a different set of Lys and Arg residues. The two sets arise from adjacent subsites that are capable of independent and sufficiently strong binding. The inhibitor is best characterized as an A5P-based substrate analogue inhibitor of KDO8PS. Five mutants in which highly conserved arginines were replaced with alanines were prepared and kinetically characterized. Our solid-state NMR observations complement the crystallographic structure of KDO8PS, and in combination with the mutagenesis results enable tentative assignment of the NMR-identified active site residues. Lys-138 and Arg-168 located at the most recessed part of the active site cavity are the chemically distinct and structurally rigid residues that bind PEP phosphate; R168A resulted in 0.1% of wild-type activity. Arg-63, exposed at the opening of the active site barrel, is the flexible residue with a generic chemical shift that binds A5P; R63A resulted in complete deactivation. The mechanistic implications of our results are discussed.

NMDA and glutamate evoke excitotoxicity at distinct cellular locations in rat cortical neurons in vitro

The development of cortical neurons in vivo and in vitro is accompanied by alterations in NMDA receptor subunit expression and concomitant modifications in the pharmacological profile of NMDA-activated ionic currents. For example, we observed that with decreasing NR2B/NR2A subunit expression ratio, the block of NMDA receptor-mediated whole-cell responses by the NR2B-selective antagonist haloperidol was also decreased. In mature cultures (>22 d in vitro), however, NMDA responses obtained from excised nucleated macropatches, which comprised a large portion of the soma, remained strongly antagonized by haloperidol. These results suggest that in more mature neurons NR1/NR2B receptors appear to be preferentially expressed in the cell body. As predicted from the whole-cell recording pharmacological profile, NMDA-induced toxicity was largely unaffected by haloperidol in mature cultures. However, haloperidol effectively blocked glutamate toxicity in the same cultures, suggesting that the neurotoxic actions of this amino acid were mostly due to the activation of somatic NMDA receptors. In experiments in which the potency of glutamate toxicity was increased by the transport inhibitor l-trans-pyrrolidine-2,4-dicarboxylic acid, the neuroprotective effects of haloperidol were significantly diminished. This was likely because of the fact that glutamate, now toxic at much lower concentrations, was able to reach and activate dendritic receptors under these conditions. These results strongly argue that exogenous glutamate and NMDA normally induce excitotoxicity at distinct cellular locations in mature mixed neuronal cultures and that NR1/NR2B receptors remain an important component in the expression of glutamate, but not NMDA-induced excitotoxicity.

Role of tumor necrosis factor-alpha in neuronal and glial apoptosis after spinal cord injury

We investigated the role of tumor necrosis factor (TNF)-alpha in the onset of neuronal and glial apoptosis after traumatic spinal cord crush injury in rats. A few TUNEL-positive cells were first observed within and surrounding the lesion area 4 h after injury, with the largest number observed 24-48 h after injury. Double-labeling of cells using cell type-specific markers revealed that TUNEL-positive cells were either neurons or oligodendrocytes. One hour after injury, an intense immunoreactivity to TNF-alpha was observed in neurons and glial cells in the lesion area, but also seen in cells several mm from the lesion site rostrally and caudally. The level of nitric oxide (NO) also significantly increased in the spinal cord 4 h after injury. The injection of a neutralizing antibody against TNF-alpha into the lesion site several min after injury significantly reduced both the level of NO observed 4 h thereafter as well as the number of apoptotic cells observed 24 h after spinal cord trauma. An inhibitor of nitric oxide synthase (NOS), N(G)-monomethyl-l-arginine acetate (l-NMMA), also reduced the number of apoptotic cells. This reduction of apoptotic cells was associated with a decrease in DNA laddering on agarose gel electrophoresis. These results suggest that: (i) TNF-alpha may function as an external signal initiating apoptosis in neurons and oligodendrocytes after spinal cord injury; and (ii) TNF-alpha-initiated apoptosis may be mediated in part by NO as produced by a NOS expressed in response to TNF-alpha.

[Pressure influence on mRNA expression and protein synthesis of inducible nitric oxide synthetase in bovine trabecular meshwork cell]

OBJECTIVE

To investigate the inducible nitric oxide synthetase (iNOS) mRNA expression and protein synthesis in bovine trabecular meshwork cell and discuss the possible effects of nitric oxide (NO) in the development of glaucoma.

METHODS

20 mm Hg, 40 mm Hg, 60 mm Hg and 80 mm Hg pressure were respectively added on cultured trabecular cells of new born bovine. No pressure group was set as the control. The changes of iNOS mRNA and protein in trabecular meshwork cells under different pressures were demonstrated qualitatively and quantitatively by in situ hybridization and nicotinamide-adenine dinucleotide phosphate diaphorase (NADPH-d) histochemical assay.

RESULTS

The expression of iNOS mRNA and its protein synthesis became higher and higher as the pressure was increased. There was weak iNOS mRNA expression in the control and 20 mm Hg groups, and no significant difference between them. 40 mm Hg and 60 mm Hg groups had a statistical difference from the control group. And 80 mm Hg group had a very significant difference from the control group. There was no difference between 40 mm Hg and 60 mm Hg groups, but they had significant difference from 80 mm Hg group. NADPH-d histochemical assay showed almost the same results except that there was significant difference between 40 mm Hg and 60 mm Hg groups.

CONCLUSIONS

Pressure can evoke the expression of iNOS mRNA, and the nitric oxide thus produced can be one of the causes of trabecular meshwork destruction, that may induce or aggravate glaucoma.

The inhibitory effects of IFN alpha-2b on EGFR expression and growth of cultured subconjunctival fibroblasts

To investigate to what extent the growth of cultured subconjunctival fibroblasts was regulated by epidermal growth factor receptor (EGFR), we observed the expression of EGFR inhibited by interferon alpha-2b (IFN alpha-2b) and determined the growth of cultured subconjunctival fibroblasts by immunohistochemical and MTT methods. The linear relationships between the concentration of IFN alpha-2b and EGFR expression or growth were y = 1252.7-554.61 lgx (r = -0.98, P < 0.01), y = 0.523-0.0421 lgx (r = -0.93, P < 0.05) respectively. The concentration of IFN alpha-2b at doubled IC50 to EGFR (6.55 x 10(3) IU/ml) only inhibited the cell growth by 25.13%. The results suggested that the growth of subconjunctival fibroblasts may be controlled by many other growth factors because it was only partially inhibited by decreasing EGFR expression.

Rapid increase in immunoreactivity to GFAP in astrocytes in vitro induced by acidic pH is mediated by calcium influx and calpain I

In higher vertebrates, reactive gliosis resulting from injury to the central nervous system (CNS) is characterized by a rapid increase in immunoreactivity (IR) to glial fibrillary acidic protein (GFAP). Little is known about the extracellular signals that initiate the increase in GFAP-IR following CNS injury. We demonstrated recently [T.H. Oh, G.J. Markelonis, J.R. Von Visger, B. Baik, M.T. Shipley, Acidic pH rapidly increases immunoreactivity of glial fibrillary acidic protein in cultured astrocytes, Glia 13 (1995) 319-322] that a rapid increase in GFAP-IR can be evoked in mature astrocyte cultures by exposing the cells to an acidic medium. We investigated the intracellular pathway(s) involved in initiating increased GFAP-IR, a hallmark of reactive astrocytes. The increase in GFAP-IR produced by exposure to acidic medium was blocked by pretreatment with nickel ions, by such blockers of L-type calcium channels as nifedipine, verapamil and diltiazem, by calpain inhibitor I, or by the intracellular calcium chelator, BAPTA-AM. At physiological pH, treatment with the calcium ionophore, A23187, resulted in increased GFAP-IR which could be blocked by pretreatment with calpain inhibitor I. Astrocytes exposed to low pH exhibited a marked increase in a GFAP fragment with a molecular weight of 48 kDa. In astrocytes exposed to acidic medium, alpha-fodrin, a selective endogenous substrate of calpain, was also found to be hydrolyzed producing fragments with molecular weights of 120-150 kDa. As anticipated, pretreatment with calpain inhibitor I prevented the proteolytic degradation of both GFAP and alpha-fodrin in these samples. These results suggest that the initial increase in GFAP-IR after CNS injury appears to be linked to Ca(++) influx, and is mediated further by a proteolytic process that seemingly involves the activation of the calcium-dependent protease, calpain I.