OBJECTIVETo investigate the effects of time varied stress on the proliferation of myoblast in rats and provide the basic experimental data for the remodeling of tissue in functional orthopaedics.

METHODSBased on the pulsatile mechanical system founded, this study loaded different strain (2.5, 5.0, 10.0 kPa) to the myoblast of lateral pterygoid muscle. The proliferation of myoblast was detected by 3H-TDR.

RESULTSAfter 6 hours under time varied strain, the significant proliferation of myoblast (P < 0.05) was observed, and the 5.0 kPa group expressed the best proliferation. After 12 hours under time varied strain, all groups expressed a better proliferation. Meanwhile, the lower frequency (0.40 Hz) had the bigger effect on the proliferation more than in the higher frequency (1.25 Hz) under the same time varied strain.

CONCLUSIONThe frequency of time varied strain had also the important influence on the proliferation, the lower frequency (0.40 Hz) had the bigger effect on the proliferation more than in the higher frequency (1.25 Hz) under the same time varied strain. In the certain period of time and certain magnitude of time varied strain, the proliferation of myoblasts rised.

Animals ; Myoblasts ; Orthopedics ; Rats ; Time

ObjectiveTo observe the distribution of vitamin D receptor(VDR) gene polymorphisms in coal-burning borne fluorosis in Guizhou province and investigate the relationship between VDR gene polymorphisms and the susceptibility to coal-burning borne fluorosis.MethodsOne hundred and fifty villagers from non-improving cooking stove villages were selected as a non-intervention group in Bijie area,Guizhou province where coal-burning borne fluorosis was prevailing; 150 villagers were chosen from cooking stove improved villages as a intervention group; 150 villagers were selected from non-endemic area Changshun county as a control group.DNA was extracted from peripheral blood samples of these people.Genotype of VDR gene Bsm Ⅰ and Fok Ⅰ loci were detected using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).ResultsDistribution of Bsm Ⅰ polymorphism site of VDR gene of control group [AA:19.3％ (29/150),AG:39.3％ (59/150),GG:41.3％(62/150)],was compared with that[AA:4.7％(7/150),AG:14.0％(21/150),GG:81.3％(122/150)] of the non-intervention group and that[AA:7.3％(11/150),AG:23.3％(35/150),GG:69.3％(104/150)] of intervention group,and the difference was statistically significant(X2 =56.6,P ＜ 0.05).The frequency of VDR-Fok Ⅰ loci in non-intervention group [TT:29.3％(44/150),TC:55.3％(83/150),CC:15.3％(23/150)] and intervention group [TT:32.7％(49/150),TC:55.3％(83/150),CC:12.0％(18/150)] was compared with that [TT:45.3％(68/150),TC:48.7％(73/150),CC:6.0％(9/150)] of control group,and the difference was statistically significant(X2 =11.9,P ＜ 0.05).Univariate analysis showed that individuals carrying the GG genotype had increased risk of suffering fluorosis than individuals carrying the AA and AG genotypes(OR values were 6.2,3.2,all P ＜ 0.05),while carrying the TC and CC genotype had increased risk of suffering fluorosis than individuals carrying the TT genotype (OR values were 1.3,2.8,1.3,2.1,all P ＜ 0.05).ConclusionVDR gene polymorphisms may be one of the predisposing factors of coal-burning borne fluorosis.

OBJECTIVETo construct a recombinant plasmid pIRES-GM-CSF-IL-21, and to investigate its antitumor effect on tumors in the mice.

METHODSFifty Bal b/c mice were included in this study. Cultured hepatoma H22 cells were inoculated in the left lobe of the liver to develop orthotopically transplanted liver tumor models. The mice with orthotopically transplanted liver tumor were randomly divided into 5 groups (n = 10): (1) Each mouse received injection of recombinant plasmid pIRES-GM-CSF-IL-21; (2) Received injection of plasmid pIRES-GM-CSF; (3) pIRES-IL-21; (4) Received injection of ampty plasmid pIRES (H22/neo group); (5) Received injection of PBS (H22 group) via the tail vein, respectively. Therefore, the anti-tumor effect was induced by both GM-CSF and IL-21, or by either of them alone. The serum levels of IFN-γ and IL-2 were detected by ELISA, and the cytotoxicity of spleen NK and CTL cells were tested by MTT colorimetry.

RESULTSComparing with the H22 and H22/Neo groups, the tumor weight in the mice of H22/GM-CSF group was (0.603 ± 0.223) g, H22/IL21-treated group (0.583 ± 0.290) g and H22/GM-CSF-IL21-treated group (0.303 ± 0.323) g, significantly lower than that in the H22 group [(1.591 ± 0.280) g] and H22/Neo group [(1.489 ± 0.155) g]. Among them the tumor growth was most significantly inhibited in the H22/GM-CSF-IL-21 group (0.303 ± 0.323) g, compared with that of H22 and H22/neo groups (P < 0.01). But there was no significant difference between the tumor weights of the H22/GM-CSF group and H22/IL-21 group, and between the tumor weights of the H22 and H22/Neo groups (P > 0.05). The levels of IFN-γ and IL-2 in peripheral blood of mouse models treated with H22/GM-CSF-IL-21 were significantly increased than that in the H22/GM-CSF group and H22/IL-21 group (all P < 0.01), but significantly decreased in the H22group and H22/Neo group (P < 0.01). The anti-tumor activity of splenic NK cells and CTLs in the H22/GM-CSF-IL21 group was significantly enhanced (P < 0.01), compared with the significantly decreased in the H22 and H22/Neo groups.

CONCLUSIONSOur results demonstrate apparent antitumor effect of the plasmid pIRES-GM-CSF-IL-21 on the orthotopically transplanted liver tumor in mice. The combination of both pIRES-GM-CSF and IL-21 is more effective than that of pIRES/IL21 or pIRES/GM-CSF treatment alone. In addition, the plasmid pIRES-GM-CSF-IL-21 can also promote the secretion of IFN-γ and IL-2 in vivo, and enhance the cytotoxic activity of splenic NK and CTLs against the transplanted liver tumor.

Animals ; Carcinoma, Hepatocellular ; blood ; pathology ; therapy ; Cell Line, Tumor ; Female ; Granulocyte-Macrophage Colony-Stimulating Factor ; genetics ; Immunotherapy ; Interferon-gamma ; blood ; Interleukin-2 ; blood ; Interleukins ; genetics ; Killer Cells, Natural ; immunology ; Liver Neoplasms ; blood ; pathology ; therapy ; Mice ; Mice, Inbred BALB C ; Neoplasm Transplantation ; Plasmids ; therapeutic use ; Random Allocation ; Recombinant Proteins ; therapeutic use ; T-Lymphocytes, Cytotoxic ; immunology ; Tumor Burden

Objective To investigate the effects of smoking on chronic obstructive pulmonary disease(COPD) and respiratory symptoms. Methods A multi-stage, stratified cluster sampling strategy was used to select participants aged 40 or older in 5 surveillance points of Anhui Province. Questionnaires, body measurements and spirometry were used to collect data. Based on complex sampling design, Logistic regression model was conducted to analyze the effects of smoking on COPD and respiratory symptoms. Results The smokers who had smoked for ≥30 pack-years accounted for 13.9% (95% CI:10.3%-17.5%, P＜0.001) of the total population. And the smokers who had smoked for ≥40 years accounted for 8.5% (95% CI:6.7%-10.3%, P＜0.001) of the total population. On average, one smoker had smoked for 32.4 years (95% CI:31.2-33.5). Average daily cigarette consumption of daily smokers was 21.1 cigarettes (95% CI:19.6-22.7). As shown by multiple-variables Logistic regression analyses, the risk of COPD and respiratory symptoms increased with the increment of smoking pack-years and duration (all Ptrend <0.001). Conclusions Smoking was associated with COPD and respiratory symptoms. The risk of developing COPD and respiratory symptoms was greater with the increment of smoking pack-years and duration.