Cytotoxic constituents from Plumbago zeylanica

The bioassay-guided fractionation of the dichloromethane extract of aerial parts of Plumbago zeylanica led to the isolation of beta-sitosterol, beta-sitosteryl-3beta-glucopyranoside, beta-sitosteryl-3beta-glucopyranoside-6'-O-palmitate (1), lupenone, lupeol acetate, plumbagin and trilinolein. Compound 1 showed cytotoxic activity against MCF7 and Bowes cancer cell lines (IC50 113 microM and 152 microM, respectively), beta-sitosterol inhibited Bowes cell growth (IC50 36.5 microM) and plumbagin was cytotoxic against MCF7 and Bowes cells (IC50 1.28 microM and 1.39 microM, respectively).     

Crinum L. (Amaryllidaceae)

Alkaloids isolated from Crinum species have been reviewed for the period 1985-2000. Non-nitrogenous compounds have been surveyed for the first time. Botanical classification and biological activity are discussed. Spectral data literature sources are listed.     

Melatonin Supplementation During In Vitro Maturation and Development Supports the Development of Porcine Embryos

Melatonin has been reported to improve the in vitro development of embryos in some species. This study was conducted to investigate the effect of melatonin supplementation during in vitro maturation (IVM) and development culture on the development and quality of porcine embryos. In the first experiment, when the in vitro fertilized embryos were cultured with different concentrations of melatonin (0, 10, 25 and 50 ng/ml) for 8 days, the blastocyst formation rate of embryos cultured with 25 ng/ml melatonin (10.7%) was significantly increased (p < 0.05) compared to the control embryos cultured without melatonin (4.2%). The proportion of DNA‐fragmented nuclei in blastocysts derived from embryos cultured with 50 ng/ml melatonin was significantly lower (p < 0.05) than that of embryos cultured without melatonin (2.1% vs 7.2%). In the second experiment, when oocytes were cultured in the maturation medium supplemented with different concentrations of melatonin (0, 10, 25 and 50 ng/ml), fertilized and then cultured with 25 ng/ml melatonin for 8 days, there were no significant differences in the rates of cleavage and blastocyst formation among the groups. However, the proportions (2.7–5.4%) of DNA‐fragmented nuclei in blastocysts derived from oocytes matured with melatonin were significantly decreased (p < 0.05) compared to those (8.9%) from oocytes matured without melatonin, irrespective of the concentration of melatonin. Our results suggest that supplementation of the culture media with melatonin (25 ng/ml) during IVM and development has beneficial effects on the developmental competence and quality of porcine embryos.     

A study of experimental autoimmune encephalomyelitis in dogs as a disease model for canine necrotizing encephalitis

In the present study, the use of dogs with experimental autoimmune encephalomyelitis (EAE) as a disease model for necrotizing encephalitis (NE) was assessed. Twelve healthy dogs were included in this study. Canine forebrain tissues (8 g), including white and grey matter, were homogenized with 4 mL of phosphate-buffered saline for 5 min in an ice bath. The suspension was emulsified with the same volume of Freund''s complete adjuvant containing 1 mg/mL of killed Mycobacterium tuberculosis H37Ra. Under sedation, each dog was injected subcutaneously with canine brain homogenate at four sites: two in the inguinal and two in the axillary regions. A second injection (booster) was administered to all the dogs using the same procedure 7 days after the first injection. Clinical assessment, magnetic resonance imaging, cerebrospinal fluid analyses, necropsies, and histopathological and immunohistochemical examinations were performed for the dogs with EAE. Out of the 12 animals, seven (58%) developed clinically manifest EAE at various times after immunization. Characteristics of canine EAE models were very similar to canine NE, suggesting that canine EAE can be a disease model for NE in dogs.     

Trends in overweight by socio-economic status in Vietnam: 1992 to 2002

OBJECTIVE: To explore socio-economic factors associated with rising rates of overweight among Vietnamese adults. DESIGN: The study was based on three national surveys of socio-economic factors and health conducted over a 10-year period. The studies were: the Vietnamese Living Standard Survey 1992-1993 (11 982 participants); the Vietnamese Living Standard Survey 1997-1998 (15 975 participants); and the Vietnamese National Health Survey 2001-2002 (94 656 participants). SUBJECTS: Male and female adults >18 years old were stratified by gender, age group, area of residence, occupation, education and relative food expenditures. Overweight was defined using body mass index (BMI) > or = 25 kg m(-2). RESULTS: Overweight rates in Vietnam more than doubled between 1992 and 2002 (from 2.0 to 5.7%). Significant increases were observed for men and women, in urban and rural areas, and for all age groups. In univariate analyses, both age and higher socio-economic status were associated with higher rates of overweight. Using the most recent survey, urban populations were more likely to be overweight than rural ones (odds ratio (OR) = 1.79), white-collar workers were more likely to be overweight than manual labourers (OR = 1.95) and persons in the top level of food expenditures were more likely to be overweight than persons in the bottom level (OR = 4.96) after adjustment for other factors. Education was inversely associated with overweight after adjusting for covariates. CONCLUSION: Economic growth and improved standard of living are associated with higher rates of overweight in nations in early stages of economic development. In Vietnam, higher rates of overweight were observed among the higher income and occupation groups.     

Molecular epidemiology of Newcastle disease viruses in Vietnam

Newcastle disease virus (NDV) causes significant economic losses to the poultry industry in Southeast Asia. In the present study, 12 field isolates of NDV were recovered from dead village chickens in Vietnam between 2007 and 2012, and were characterized. All the field isolates were classified as velogenic. Based on the sequence analysis of the F variable region, two distinct genetic groups (Vietnam genetic groups G1 and G2) were recognized. Phylogenetic analysis revealed that all the 12 field isolates fell into the class II genotype VII cluster. Ten of the field isolates, classified as Vietnam genetic group G1, were closely related to VIIh viruses that had been isolated from Indonesia, Malaysia, and Cambodia since the mid-2000s, while the other two field isolates, of Vietnam genetic group G2, clustered with VIId viruses, which were predominantly circulating in China and Far East Asia. Our results indicate that genotype VII viruses, especially VIIh viruses, are predominantly responsible for the recent epizootic of the disease in Vietnam.     

Comparison of arylalkylamine N-acetyltransferase and melatonin receptor type 1B immunoreactivity between young adult and aged canine spinal cord

Melatonin affects diverse physiological functions through its receptor and plays an important role in the central nervous system. In the present study, we compared immunoreactivity patterns of arylalkylamine N-acetyltransferase (AANAT), an enzyme essential for melatonin synthesis, and melatonin receptor type 1B (MT2) in the spinal cord of young adult (2~3 years) and aged (10~12 years) beagle dogs using immunohistochemistry and Western blotting. AANAT-specific immunoreactivity was observed in the nuclei of spinal neurons, and was significantly increased in aged dog spinal neurons compared to young adult spinal neurons. MT2-specific immunoreactivity was found in the cytoplasm of spinal neurons, and was predominantly increased in the margin of the neuron cytoplasm in aged spinal cord compared to that in the young adult dogs. These increased levels of AANAT and MT2 immunoreactivity in aged spinal cord might be a feature of normal aging and associated with a feedback mechanism that compensates for decreased production of melatonin during aging.     

Preparation and characterization of electroless nickel-coated cellulose fibres

The aim of this project was to fabricate electroless nickel-coated cellulose fibres. Ultimately, these nickel-coated cellulose fibres will be used to develop a cost-effective polymer composite for electromagnetic interference (EMI) shielding and/or electrostatic discharge (ESD) applications. An attempt has been made to impart electrical conductivity onto cellulose fibres via an electroless nickel plating process. The aim was to achieve a homogeneous, continuous layer of Ni on the cellulose fibres, and the plating conditions were optimized to achieve this. The relationship between the coating morphology and the performance of the coated fibre was also of interest. Testing was carried out using cellulose filter paper and then loose cellulose fibres. Scanning electron microscopic (SEM) images of nickel-coated filter paper showed that nickel particles are bonded to the cellulose fibres. The coating appeared more compacted and continuous as plating time increased, corresponding to lower surface resistivity. This observation suggested a correlation between morphology and electrical conductivity of the coating. For nickel-coated cellulose fibres, after optimization of plating conditions, a uniform deposition of nickel particles around the cellulose surfaces was confirmed by SEM images. EDS and XRD results confirmed similar coating could be produced on filter paper and cellulose fibres. SEM images of cross-sectioned nickel-coated cellulose fibres illustrated nickel particles had penetrated into the inner walls of the cellulose fibres. This impregnation of the fibres should act to increase the bonding between nickel coating and cellulose fibres. These nickel-impregnated cellulose fibres could now be incorporated into a polymer matrix to create an electrically conducting composite with the right processing parameters.     

越南安息香的低温半致死温度与抗寒适应性

以越南河内(Hanoi)、江西吉水(Jishui)、湖南资兴(Zixing)3个产地1年生越南安息香幼苗为试材,采用人工模拟低温处理技术进行低温处理,测定电解质外渗率,并配合Logistic方程对不同产地枝条的半致死温度(LT50)进行了拟合;测定低温处理下各产地越南安息香的MDA含量、根系活力,并观察不同产地越南安息香1年生幼苗的恢复情况.结果表明,3个产地越南安息香耐低温能力差异显著,半致死温度值LT50在-14.93～-9.48℃之间,抗寒性强弱排序依次为:Zixing＞ Jishui＞ Hanoi;幼苗叶片MDA含量、根系活力及抽条指数均反映出产地抗寒性强弱与半致死温度基本一致.