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Biomedical subjects

S H Lu

Publications and source records attributed to S H Lu.

45 records · Page 3Linked to original sources
PubMed1982

Recent research on the etiology of esophageal cancer in China.

China could be expected to offer good opportunities for the investigation of esophageal cancer since it has both high and low incidence areas. However, it seems impossible to attribute the induction of esophageal cancer to one particular substance--it rather seems to be caused by a variety of factors. To the authors' opinion, esophageal cancer may originate from exposure to N-nitroso compounds or mycotoxins. Lack of certain trace elements or essential vitamins may also play a role. Contrary to France, which also has high incidence areas of esophageal cancer, excessive alcohol consumption is of no importance in China. It is not clear whether genetic factors can be discussed.

Cell Transformation, Neoplastic↗
PubMed1981

Mutagenicity of extracts of pickled vegetables collected in Linhsien County, a high-incidence area for esophageal cancer in Northern China.

Extracts of pickled vegetables commonly consumed in Linhsien County, a high-incidence area for esophageal cancer in Northern China, were studied for mutagenicity. The liquid residue from ethereal extracts produced a dose-dependent increase of mutants in Salmonella typhimurium TA98 and TA100 strains; mutagenicity required the presence of a fortified liver microsomal activation system induced by Aroclor 1254 in adult male BD VI inbred rats. An amount of extract equivalent to 2.8 g fresh pickled vegetables produced sixfold (75 revertants/g) and twofold (45 revertants/g) increases in revertant frequencies in strains TA98 and TA100, respectively. Roussin's red methyl ester, a tetranitroso compound, [(NO)2Fe(CH3S)]2, not previously reported to occur in nature, was isolated and identified from the ethereal extracts. The synthetic compound was mutagenic in strain TA100 in the presence of a liver activation system, producing 25 revertants/mumol. Findings on the presence of mutagenic compounds in pickled vegetables were discussed in relation to their possible etiologic role in cancer of the esophagus in Linhsien County.

China↗
PubMed1980

Mutagenicity in Salmonella typhimurium of N-3-methylbutyl-N-1-methyl-acetonyl-nitrosamine and N-methyl-N-benzylnitrosamine, N-nitrosation products isolated from corn-bread contaminated with commonly occurring moulds in linshien county, a high incidence area for oesophageal cancer in Northern China.

Two synthetic N-nitrosamines (N-3-methylbutyl-N-1-methyl acetonylnitrosamine and N-methyl-N-benzylnitrosamine), previously isolated from corn-bread which had been inoculated with moulds occurring in Linshien county, Northern China and subsequent nitrosation by sodium nitrite, were tested in Salmonella typhimurium strains TA1535 and TA100 in the presence of a liver postmitochondrial supernatant from Aroclor-treated rats. A concentration-dependent increase in the number of mutant colonies in both bacterial strains was observed when N-3-methylbutyl-N-1-methylacetonyl-nitrosamine was assayed in liquid suspension and N-methyl-N-benzylnitrosamine in plate incorporation assays. Our finding that mutagenic N-nitrosamines are present in foodstuffs that may be consumed in Linshien county are discussed in relation to the possible etiological role of these compounds in cancer of the oesophagus in that area.

Animals↗
PubMedDate not supplied

Placement matching: challenges and technical progress.

Although it is highly desirable, standardized placement matching for substance use disorders poses challenges due to variability in settings, services, and syndromes; multidimensionality of clinical problems; multiplicity of outcome constructs; and temporal phenomena in the course of recovery. Despite these obstacles, progress is being made in developing patient placement criteria that are comprehensive with adequate reliability, feasibility, and resolution. With these methodological advances, it has been possible to initiate controlled research with placement criteria. The first such studies provide early evidence supporting such criteria and indicate areas for refinement.

Combined Modality Therapy↗
PubMedDate not supplied

Characterization of chemoresistance mechanisms in a series of cisplatin-resistant transitional carcinoma cell lines.

We explored the mechanisms of cisplatin resistance in a series of bladder transitional carcinoma cells that are either sensitive or progressively resistant to cisplatin. Resistant lines were raised by chronic exposure of the parental cells to progressively increased concentrations of cisplatin. The cisplatin IC50s of the sensitive and the three resistant cells were 4.3, 25.0, 40.4, and 52.2 microM, respectively. The expressions of glutathione S-transferase pi (GST-pi) and multidrug resistance-associated protein (MRP) were enhanced in a dose-response manner as cells acquired progressive cisplatin resistance. Expression of mdr-1 transcript was detected in the three resistant lines but not in the sensitive line. Glutathione contents were increased in resistant cells, yet the trend of increase did not reach statistical significance (p = 0.061). In conclusion, transitional carcinoma cells may gain cisplatin resistance through multiple pathways including up-regulation of GST-pi, MRP and possibly mdr-1. Glutathione contents may play a less significant role in cisplatin chemoresistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗