1999 Vol. 12, No. 4
Four kinds of assays were used to study the effect of a fat-soluble extract of spinach powder(SPFE) on the proliferation of human gastric adenocarcinoma cell line (SGC-7901) in vitro.These studies included: ( i ) cell growth assay, ( ii ) colony forming assay, ( iii ) MTT colorimetric assay, and ( iv ) 3H-TdR incorporation assay. The concentrations of SPFE expressed as the level of β-carotene in the medium were 2 × 10-s, 2 × 10-7 and 2 × 10-6 mol/L β-carotene in assays ( i ) ～ ( iii ), but 4 × 10-8, 4 × 10-7 and 4 × 10-6 mol/L β-carotene in assay ( iV ) respectively. The results indicated that SPFE inhibited the proliferation and colony forming ability of SGC-7901 cells. And in MTT assay, SPFE inhibited the viability of SGC-7901 cells, but no inhibitory effect of SPFE was observed on the viability of lymphocytes in peripheral blood of healthy people. Finally, in the 3H-TdR incorporation test, both SPFE and β-carotene showed significant inhibitory effects on DNA synthesis in SGC-7901 cells, but SPFE was more effective than 3-carotene.
This study was designed to explore the possibility of using ascitic mouse sarcoma cell line(S180) to validate the mouse tumor cell attachment assay for developmental toxicants, and to test the inhibitory effects of various developmental toxicants. The results showed that 2 of 3 developmental toxicants under consideration, sodium pentobarbital and ethanol, significantly inhibited S180cells attachment to Concanavalin A-coated surfaces. Inhibition was dependent on concentration, and the IC5o(the concentration that reduced attachment by 50% ), of these 2 chemicals was 1.2 ×10-3 mol/L and 1.0 mol/L, respectively. Another developmental toxicant, hydrocortisone, did not show inhibitory activity. Two non-developmental toxicants, sodium chloride and glycine were also testedand these did not decrease attachment rates. The main results reported here were generally similar to those obtained with ascitic mouse ovarian tumor cells as a model. Therefore, this study added further evidence to the conclusion that cell specificity does not limit attachment inhibition to Con A-coated surfaces, so S180 cell may serve as an alternative cell model, especially when other cell lines are unavailable. Furthermore, after optimal validation, it can be suggested that an S180 cell attachment assay may be a candidate for a series of assays to detect developmental toxicants.
The objective of the current study is to discuss the problems related to how data is used to calculate Years Lost with Disability (YLD) with the method recommended by the World Bank. The study includes collecting useful data, estimating disease duration and average age of disease onset,adjusting incidence and prevalence data by means of a software programme, DISMOD ( Harvard University Incidence & Prevalence Model), and assessing the importance of YLD calculation for different diseases.Remission and fatality rates of 3 diseases were estimated by experts at 2 round consultations.Incidence rates, disease duration and average age of disease onset were calculated and adjusted by DISMOD. YLD due to schizophrenia is the highest among 4 diseases in two regions. YLD is18.88% in disability adjusted life year for 4 diseases in Xiacheng District, and 19.97% in Fuyang County.Available data can be used for the calculation of YLD after being adjusted. DISMOD is a useful instrument to test the internal consistency of incidence, prevalence, remission and fatality rate. The adjusted data are acceptable to experts and DISMOD. To get rational remission and fatality rates, we can use a cohort method through expert consultations. To reflect overall burden of disease, YLD calculation should be used.
1999, 12(4): 270-284.
Triplet surveys were conducted in the city of Xi' an and two villages (one in the vicinity and the other at a distance) in Shaanxi Province in China in October-November (when agricultural activitis were low), 1997, to elucidate nutrient intakes with a focus on possible urban-rural differences. Total food duplicate samples were collected from non-smoking and non-habitually drinking adult healthy women (about 50 subjects per site and 149 in total). The nutrient intakes were estimated from the weight of food items in reference to national food composition tables. On average, the women took 1873 kcal energy, 54 g protein and 37 g lipid per day, with a lipid energy ratio of18.4%. Both excess and insufficient energy intake was observed as a result of food intake analysis and body mass index determination. With regard to minor nutrient intakes, insufficiency was serious in the case of calcium, vitamin A and vitamin B2, but not with iron. Whereas dependency on plant foods for sources of energy and protein was common to the three regions, Xi' an people consumed more animal foods than those in the villages. Intake of fish and shellfish was quite low throughout the three regions. Among the four types of cereals, wheat was consumed most substantially in the three regions and in three meals (except for the village where people essentially did not take lunch in reflection of low agricultural activities), whereas rice was consumed more in Xi' an than in the two villages. Maize consumption was higher in the two villages (especially for breakfast) than in the city.In contrast, foxtail millet (although in small amounts) was taken primarily in Xi'an and only at the time of breakfast.
The therapeutic efficacy of a combination of meso 2,3-dimercaptosuccinic acid (DMSA) and calcium disodium EDTA in protecting testicular disorders in chronic lead intoxication was investigated. The results indicate that two five-days courses of the combined therapy produced a more effective recovery in the lead induced biochemical and histopathological disorders compared to conventional single 5 days therapy. No adverse effect of the chelators, when administered individually or in combination, was noticed in the testes of control (without lead exposure) animals.
Propoxur is a widely used dithiocarbamate insecticide. In this study, the clastogenic effect of propoxur has been evaluated using chromosomal aberration assay in mouse bone marrow cells. Singlei. p. administration of propoxur, at 25 nag/kg b.wt., a maximum tolerated dose (MTD) and 12.5mg/kg b.wt (50% of MTD) have significantly induced different types of aberrations after 24 h of treatment. The aberrations were dose and time dependent and reached a maximum after 24 h of exposure. The sresult suggest a genotoxic potential of propoxur.
1999, 12(4): 296-303.
The objective of the present study is to purify oligasaccharides (OSs) from serogroup B meningacocci (3407 or 542852) with common lipooligosaccharide (LOS) immunotypes prevalent in China and to successfully conjugate them to their outer membrane protein complexes ( OMPCs).Conjugates possessing broad cross-reactivity with different serogroup B meningacocci were obtained.Both LOSs from the above two strains were purified on a Sephadex G75 column and hydrolyzed with acetic acid, and then the pure OSs were obtained by using a Sephedex G50 chromatographic column. The pure OSs were conjugated to corresponding OMPCs by carbodiimide mediated condensation. Mice were immunized with the OS-OMPC conjugates to produce antibodies. Immunogenicities of the conjugates were tested by ELISA, bactericidal test and Western-blotting. The titers of antibodies against OS and LOS elicited by the two OS-OMPC conjugates increased respectively by 2.5 and 2 to 10 times as compared with those of antibodies against unconjugated OS and LOS. The sera elicited by the conjugates possessed a stronger bactericidal activity to the strains (3407,542852,29021) with the same LOS immunotype than to the strain with different LOS immunotype (86155).The results determined by ELISA indicated that the sera against the conjugates showed strong response to the strains with the same or different LOS immunotypes. It was confirmed by western-blotting analysis that the sera elicited by the two conjugates reacted with 42, 39 and 26 kDa proteins from the OMPC. Among the reactive bands, the 42kDa proteins were class I OMPs. The two serogroup B meningococcal OMPCs were strong immunogans and good carriers coupling with OSs as well. The immtmogancity of the conjugated OS was increased and the OS-OMPC conjugates of the serogroup B mengingococci showed a broad antigenic response to the strains tested.
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