OBJECTIVETo study toxic effects of 2,5-hexanedione (2,5-HD) on pathology and lipid peroxidation in mouse retina.

METHODSForty-eight mice were randomly divided into blank control group (12 mice), negative control group exposed to normal solution (12 mice) and group exposed to 2,5-HD for 2. 4 and 8 weeks, respectively (24 mice) by intraperitoneal injection (2.5% 2,5-HD) at the dose of 400 mg/kg. The pathological changes of mouse retina were examined under light microscope. The activity of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) in mouse retina were detected.

RESULTSThe retinal structure in the blank and negative control groups was normal. In mice exposed to 2,5-HD for 8 weeks, the swelling of outer and inner segments and disorder arrangement of the segments without clear boundary were found. The staining of outer plexiform layers was uneven and the irregular loose structure appeared. The hyperchromatic pyknotic and necrosis nuclei were presented in ganglion cells layer. Compared with the control and blank groups, the activities of SOD gradually and significantly reduced and the concentrations of MDA increased in group exposed to 2,5-HD (P < 0.05).

CONCLUSION2,5-HD can induce the injury of retina tissues of mice, which may be associated with the lipid peroxidation.

Animals ; Hexanones ; toxicity ; Lipid Peroxidation ; drug effects ; Malondialdehyde ; metabolism ; Mice ; Mice, Inbred Strains ; Retina ; drug effects ; metabolism ; pathology ; Superoxide Dismutase ; metabolism

OBJECTIVETo study the effect of occupational exposure to traffic exhaust and smoking on DNA damage in traffic policemen.

METHODS812 traffic policemen (741 men and 71 women, 130 of office-work and 682 of outside work) from 8 districts in Guangzhou were investigated. Blood samples were taken by venipuncture and lymphocytes were collected by using lymphocyte separation medium and centrifugation. The comet assay was used to measure DNA damage.

RESULTSThe office-work policemen [(37.7 +/- 9.5) years] were older than the outside-work ones [(32.3 +/- 8.1) years, P < 0.001]. No significant difference was observed in sex (P = 0.08) and age (P = 0.45). Comet assay showed that occupational exposure to traffic exhaust significantly increased tail length [4.20 micro m, 95% CI: (3.98 - 4.42) micro m vs 3.23 micro m, 95% CI: (2.82 - 3.7) micro m, P < 0.001]. Smokers had longer tail length [4.66 micro m, 95% CI: (4.37 - 4.97) micro m] than ex-smokers [3.28 micro m, 95% CI: (2.57 - 4.17) micro m] and nonsmokers [3.47 micro m, 95% CI: (3.21 - 3.75) micro m, P < 0.001]. In nonsmokers, significant increase in tail length was observed by passive smoking at home (P = 0.004) but not at work (P = 0.22). When out-door nonsmokers were excluded, passive smoking at work also significantly increased tail length (P = 0.007). Analysis of covariance showed that occupational exposure to traffic exhaust, tobacco smoking, and female had independent effect on lymphocyte DNA damage (P < 0.001) after these factors were adjusted. Passive smoking and age had no effect on lymphocyte DNA damage.

CONCLUSIONSOccupational exposure to traffic exhaust and tobacco smoking respectively increase lymphocyte DNA damage. Female traffic policemen may have more severe DNA damage than male.

Adult ; DNA Damage ; Female ; Humans ; Lymphocytes ; metabolism ; Male ; Occupational Exposure ; Oxidation-Reduction ; Police ; Smoking ; adverse effects ; Vehicle Emissions ; adverse effects

OBJECTIVETo study the effect of NP9 on the growth of transplanted nasopharyngeal carcinoma (NPC) in nude mice and explore the mechanisms involved.

METHODSRecombinant pRc/CMV2-NP9 plasmid was constructed and transfected into the NPC cell lines by lipofectamine 2000. Cell clones stably expressing NP9 were obtained by detecting the mRNA expression of NP9 in G418-resistant clones with RT-PCR. The tumorigenicity and size of transplanted tumors were assessed after inoculation of NPC cells and their transgene clones into Balb/C mice. The expression of PCNA and cyclin D1 in transplanted tumors was detected by immunohistochemistry.

RESULTSThe expression of NP9 was detected in some of NP9 gene-transfected G418-resistant clones of CNE1 and SUNE1. In vivo experiments showed that the tumorigenicity of CNE19 clone was decreased significantly compared to that of CNE1 and its vector control, and the transplanted tumors grew more slowly from SUNE1/NP9 than from SUNE1 and SUNE1/vector. Compared with the vector control, the expression of cyclin D1 and PCNA in CNE1/NP9 transplants was decreased.

CONCLUSIONNP9 inhibits tumorigenicity and growth of NPC transplanted tumor by down-regulating the expression of cyclin D1 and PCNA.

Animals ; Cyclin D1 ; biosynthesis ; genetics ; Endogenous Retroviruses ; genetics ; Female ; Gene Products, env ; biosynthesis ; genetics ; Genes, Tumor Suppressor ; Humans ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Nasopharyngeal Neoplasms ; genetics ; metabolism ; pathology ; Neoplasm Transplantation ; Proliferating Cell Nuclear Antigen ; biosynthesis ; genetics ; Tumor Cells, Cultured

OBJECTIVETo evaluate the expression of three different RASSF1 transcripts and its clinical significance in lung carcinomas.

METHODSThe mRNA expression of RASSF1A, RASSF1B and RASSF1C was detected by RT-PCR in 51 human lung cancer tissues and 51 matched normal tissues.

RESULTS1. The mRNA expression of three RASSF1 transcripts was detectable in all non-cancer tissues. However, high rate of expression loss of RASSF1A and RASSF1B existed in lung cancer tissues, which was 53.2% (2851) and 37.3% (19/51), respectively. RASSF1C was expressed in all of the tumor tissues. 2. Loss or abnormal down-regulation of RASSF1A was positively related with lymph node metastasis and TNM stage (P < 0.05) and 3. RASSF1B and RASSF1C mRNA expression was not correlated with TNM stage, histological type, differentiation grade or smoking index.

CONCLUSIONThere is a significant expression difference among the three RASSF1 transcripts in lung carcinoma. RASSF1A, closely associated with lymph metastasis and TNM stage of lung carcinoma, should be a new tumor suppressor gene.

Chromosome Deletion ; Chromosomes, Human, Pair 3 ; Genes, Tumor Suppressor ; Humans ; Lung Neoplasms ; genetics ; pathology ; Lymphatic Metastasis ; Neoplasm Staging ; RNA, Messenger ; analysis ; Tumor Suppressor Proteins ; genetics

OBJECTIVETo explore the relationship between the overexpression of PKA RIalpha mRNA and cliniopathological parameters in lung cancer.

METHODSRT-PCR was used to detect the expression of PKA RIalpha mRNA in 54 cases with human lung cancer and matched normal tissues.

RESULTS(1) The expression of PKA RIalpha mRNA was significantly higher in cancer tissue (66.7%) than in normal tissues (20.4%) (P < 0.01). (2) The expression was significantly correlated with TNM stage (P < 0.01), being increased with TNM stage. (3) The expression was significantly higher in patients with positive lymph nodes than in those with negative lymph nodes (P < 0.01). (4) There were no significant associations of PKA RIalpha mRNA expression with histological type, differentiation grade or size of the tumor.

CONCLUSIONThis study indicates that the overexpression of PKA RIalpha mRNA may play an important role in the progression, metastasis and prognosis of lung cancer.

Adenocarcinoma ; metabolism ; secondary ; Adult ; Aged ; Carcinoma, Squamous Cell ; metabolism ; secondary ; Cyclic AMP-Dependent Protein Kinase RIalpha Subunit ; Cyclic AMP-Dependent Protein Kinases ; biosynthesis ; genetics ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Lung Neoplasms ; metabolism ; pathology ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Staging ; Prognosis ; RNA, Messenger ; biosynthesis ; genetics

Objective Throush identify biochemical characteristics and virulence factors of 2 strains suspected Yersinia pestis(Y.pestis)isolated from the dead Marmota himalayana(M.himalayana)to confirm the nature epidemic focus in Dege County,Sichuan Province.Methods Y.pestis was analyzed by specific staining and shape,culturing characteristics,splitting-test by bacteriophage,test of biochemical characteristics and glycolysis ability,virulence factors,virulence,nutritional requirement,plasmid,genetic test and genetic type. Results The tested strains were Gram staining bacilus.The main biochemical characteristics were Arabinose(+)、 Rhamnose(-),Maltose(+),Melibiose(-),Glycerol(+),Denitrification(+).The virulence factors with FI+.VW+, Pgm+,Pst I+;and with the common 6.0×106,45.0×106,65.0×106 plasmids,also with the virulence-relative plasmid gene.Both their absolutely lethal dose(LD100)in mice were 50 bacteria.The nutritional requirement appeared which were depended on Phenylalanine and Methionine.With the Genomovar 5 genotype characteristics of M.himalayana plague foci of Qinghai-Tibet plateau.The difference between tested strains and Yersinia pseudotubercuosis on the 3 different culture medium was obvious.The tested strains had a Y.pestis' specific 3a fragment,Pst I and FI-Ag,at 22 ℃,the strains could be split by bacteriophage completely.Conclusions According to the diagnostic criteria of plague in China,the 2 suspected strains isolated from Dege County,Sichuan Province ale confirmed as Y.pestis.both with powerful virulenceand with the characteristics of the Y.pestis of M.himahtyana in Qinghai-Tibet plateau plague natural focus.