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Biomedical subjects

L H Song

Publications and source records attributed to L H Song.

11 recordsLinked to original sources

Low frequency of mutations in the X gene, core promoter and precore region of hepatitis B virus infected Vietnamese.

Numerous mutations in the hepatitis B virus (HBV) genome have been described, but in most cases their role in the pathogenesis of HBV infection is still unclear. Therefore, we analysed specific mutations in HBV-infected Vietnamese patients and assessed their potential relationship with their clinical outcome. A total of 153 HBV-infected Vietnamese patients with well-characterised clinical profiles were enrolled. None of the study participants had a history of alcohol or drug use and none received any antiviral or immunosuppressive therapy before or during the course of this study. The HBx- and core promoter regions were analysed by sequencing. The majority of isolates corresponded to genotype A. The presence of hepatitis B e antigen (HBeAg) was associated with significantly higher viral loads in the chronic HBV-infection group (P = 0.026). Double mutations in the core promoter (1762/1764) were more frequent in those with cancer than in noncancer patients (P < 0.01). Mutations at nucleotide (nt) 1766/1773 were found at low prevalence but with no obvious association to clinical presentation. Cytosine at nt 1858 was predominant but the stop codon mutation in the precore region was not detected. In the study, 4/48 hepatocellular carcinoma (HCC) patients revealed truncated HBx, whilst the serine to alanine mutation (codon 31) of HBx was more prevalent in cancer patients than in asymptomatic HBV carriers (P < 0.01). Thus, the low frequency of mutations indicates the relation of the absence of antiviral pressure in this population. The exclusively found prevalence of certain mutations detected in those with HBV-related carcinoma nevertheless indicates a degree of association with disease progression.

Adult↗

Technical aspect of ThinPrep.

AIM OF STUDY: To analyze the common technical problems encountered in ThinPrep preparations. METHOD: A prospective and retrospective study of eight hundred and fifty (n = 850) conventional cervical smears with its corresponding paired ThinPrep specimens from July 1998 to December 1998. RESULTS: 139 ThinPreps were found to be technically suboptimal. Of these, 81 showed "patchy cells lost"; 18 showed "thick preparations"; 24 demonstrated "halo effect'" where the cellular material collected at the periphery of the cell circle, and 16 had "obscuring blood and amorphous debris", rendering the preparations "satisfactory for evaluation but limited" by the presence of the above artifacts. CONCLUSION: Despite its many advantages in providing standardization of specimen preparation, superb cellular presentation, reduction in the number of unsatisfactory reports and increased lesion detection rate, ThinPrep has its own limitations in terms of technical problems, ease of operation and cost effectiveness.

Culture Techniques↗

Urban-rural comparison on cadmium exposure among general populations in Shandong Province, China.

In 1996, peripheral blood samples and 24-h food duplicate samples together with samples of wheat, rice, foxtail millet and maize were collected from 50 non-smoking women each from Jinan (a provincial capital) and Baiquan (a nearby basically self-sustaining farming village) in China. The samples were analyzed for cadmium (Cd) contents by graphite furnace atomic absorption spectrometry after wet digestion. The dietary Cd intake of the people in the city was 6.4 micrograms/day as a geometric mean (GM) and 5.9 micrograms/day for the villagers. The Cd level in blood was 0.48 and 0.29micrograms/l (as GMs) for the city and village people, respectively. Thus, Cd burden of the people in the city tended to be greater than that for those in the village. Nevertheless, the Cd burden of the Jinan citizens was lower than the values published for people in large cities in China. When Cd intake via the four cereals was compared with Cd in total food to estimate the total contribution of the four cereals (combined) in total dietary Cd intake, the cereals accounted for 60% of total dietary Cd intake among the city people and as high as 78% among the villagers. Cadmium contents in the four cereals were in a narrow range and it was considered acceptable to combine all cereals in evaluating them as dietary Cd sources.

Adult↗

Inhibition of the specific 3H-DL-Glu binding in the hippocampus of rat brain by lead.

The effect of Pb2+ on 3H-DL-Glutamate (3H-DL-Glu) binding in the membrane preparations from the hippocampus of rat brain was investigated with a view to explaining the cognitive and learning deficits produced by the heavy metal. The results indicated that Pb2+ (3.1-25.0 mumol.L-1) inhibited 3H-DL-Glu binding in a concentration-dependent manner. Scatchard analysis further revealed that at a concentration of 6.3 mumol.L-1 Pb2+ interfered with binding mainly through significantly decreasing the density of binding sites. This finding provided an important insight into Pb2(+)-induced impairments in learning and memory previously documented in children and in experimental animals chronically exposed to Pb2+.

Animals↗

Maize and foxtail millet as substantial sources of dietary lead intake.

In 1996, 24-h food duplicate samples were collected from two groups of 50 non-smoking women each; one group was in Jinan, the capital city of Shandong Province in China, and the other in a farming village in the Zhangqiu area some 30 km away from the city. The people in the village took significantly more dietary lead (46 micrograms/day) than their counterparts in the city (26 micrograms/day), and blood lead concentrations (35 and 50 micrograms/l for the urban and the rural people, respectively) were in parallel with the dietary lead intake. Search for cereals as the determinants of dietary lead intake and blood lead concentration by multiple regression analysis showed that maize was the most influential source of dietary lead intake among the four common cereals of wheat, rice, foxtail millet (to be called just millet) and maize, whereas millet was the leading determinant of the blood lead level among the four cereals although the influential power was weaker than millet for dietary lead. Lead content in maize (47 ng/g) and millet (47 ng/g) was twice or even more times higher than the levels in wheat (26-30 ng/g) and rice (20-21 ng/g). The significant roles of non-rice/non-wheat cereals such as millet and maize as possible dietary lead sources for farming populations are discussed.

Adult↗

Urban-rural comparison of nutrient intake by adult women in Shandong Province, China.

In 1996, 24-hour food duplicate samples were collected from two groups of 50 nonsmoking women each; one group was in Jinan, the capital city for of Shandong Province in China, and the other in a farming village in Zhangqiu area some 30 km away from the city. They had also physical examinations including hematology and serum biochemistry tests. Nutritional analysis of the duplicate samples were conducted utilizing standard food composition tables for Chinese populations. The urban-rural comparison between the two groups showed that women in Zhangqiu took significantly less lipid (54 g/day) and more carbohydrate (335 g/day) than Jinan counterparts (76 g lipid and 254 g carbohydrate/day), although there was no significant difference in total energy and protein intake (1968 kcal/day in Jinan vs. 2071 kcal/day in Zhangqiu, and 67 g protein/day in Jinan vs. 61 g/day in Zhangqiu). The intakes of the three major nutrients were sufficient in majorities of members in both groups. Iron intake was also sufficient (22 and 25 mg/day in Jinan and Zhangqiu, respectively), but intake of calcium was insufficient in more than a half of the subjects in both groups. Zhangqiu women heavily depended on plant-based foods both for protein and lipid, whereas the dependency was less remarkable among Jinan women.

Adult↗

Urban-rural difference in cereal consumption by people in Shandong Province, China.

In October, 1996, 24-hour food duplicate samples were collected from two groups of 50 adult women each; one group was in Jinan, the capital city of Shandong Province in China, and the other in a farming village of Baiquan in Zhangqiu area some 30 km away from the city. Perusal of food menus showed that wheat, rice, foxtail millet and maize were major cereals for the two groups. Nutritional analysis of the food duplicate samples were conducted taking advantage of weight of each food item and the standard food composition tables for Chinese populations. Whereas wheat was the leading source in both groups (73% of cereal-based energy in the city and 64% in the village), further urban-rural comparison showed that women in the village took substantial amounts of millet (19%) and maize (12%) in contrast to small consumption by the city people (millet by 5% and maize by 2%). Rice consumption was larger in the city (20%) than in the village (5%). The differences between the two groups were all significant for each of the four cereals. Nutritional significance of consumption of maize in particular and also that of millet were discussed.

Adult↗

Urban-rural comparison of HBV and HCV infection prevalence among adult women in Shandong Province, China.

In order to make urban-rural comparison of the prevalence of hepatitis B and C virus (HBV and HCV, respectively) infection in China, a twin survey was conducted in 1996 on two groups (50 subjects each) of 21-55 year-old, apparently healthy women for infection markers and serum enzyme levels; one group (the urban group) was in Jinan, the provincial capital of Shandong Province, and the other (the rural group) was in a farming village in Zhangqiu area some 30 km away from Jinan City. Comparison between the two groups showed that there was no significant (p > 0.10) difference in the prevalence of HBsAg+, anti-HBs+, anti-HBc+ and the cases positive to any of three HBV infection markers (i.e. HBV+). No age-dependent difference was detected within or between the groups. Thus the overall positivity rate was 8% for HBsAg+, 47% for anti-HBs+, 48% for anti-HBc+, and 64% for HBV+. No anti-HCV+ case was found either in the urban group or in the rural group. Liver function remained normal in all cases studied. The results together with perusal of published data suggest the urban-rural difference will not be remarkable, if present, in HBV and HCV infection in the regions studied, and possibly in China as a whole.

Adult↗

Nutritional status in Linxian, China: effects of season and supplementation.

The ability of a supplement to counteract seasonal alterations in nutritional status for certain vitamins was studied in Linxian, an area in northern China with high rates of esophageal cancer. 150 subjects took one daily pill from April to August (16 weeks), whereas 50 subjects did not take any supplement. Deficiencies of ascorbic acid, riboflavin, folic acid, retinol and tocopherol were prevalent at the outset of the study. The changes in diet occurring between the end of the winter (April) and the start of the autumn vegetable harvest (August) were reflected in greatly improved ascorbic acid status and slightly improved riboflavin status. Plasma retinol, tocopherol, alpha-carotene and beta-carotene were little affected by season, whereas erythrocyte folate levels declined. The ascorbic acid, riboflavin, folate, retinol and tocopherol status of the supplemented subjects was significantly improved. After 16 weeks of supplementation, erythrocyte folate levels of subjects with esophageal dysplasia were improved but remained significantly lower than those of normal supplemented subjects, targeting folic acid as a nutrient of particular interest in this precancerous condition.

Anthropometry↗