Structure and dynamics of an active polymer adsorbed on the surface of a cylinder.

The structure and dynamics of an active polymer on a smooth cylindrical surface are studied by Brownian dynamics simulations. The effect of an active force on the polymer adsorption behavior and the combined effect of chain mobility, length N, rigidity κ, and cylinder radius, R, on the phase diagrams are systemically investigated. We find that complete adsorption is replaced by the irregular alternative adsorption/desorption process at a large driving force. Three typical (spiral, helix-like, and rod-like) conformations of the active polymer are observed, dependent on N, κ, and R. Dynamically, the polymer shows rotational motion in the spiral state, snake-like motion in the intermediate state, and straight translational motion without turning back in the rod-like state. In the spiral state, we find that the rotation velocity ω and the chain length follow a power-law relation ω ∼ N-0.42, consistent with the torque-balance theory of general Archimedean spirals. And the polymer shows super-diffusive behavior along the cylinder for a long time in the helix-like and rod-like states. Our results highlight that the mobility, rigidity, and curvature of surface can be used to regulate the polymer behavior.

[Cognitive behavioral therapy for depression in advanced schistosomiasis patients].

OBJECTIVE: To evaluate the efficacy of cognitive behavioral therapy for depression in advanced schistosomiasis patients. METHODS: A total of 60 advanced schistosomiasis patients with major depressive disorder were divided into a combination therapy group (30 cases) who received sertraline plus cognitive behavior therapy and a monotherapy group (30 cases) who received sertraline only. Before the treatment and at the 1st, 2nd, 4th, 8th week after the treatment, the efficacy and safety were assessed with the HAMD17 item score and the related factor points and TESS. The effective rate, side effect rate and relapse rate in six months were calculated and compared between the two groups. RESULTS: At the end of 8th week after the treatment, the total scores of HAMD, factor scores of cognitive impairment, retardation factor scores and sleep disturbance factor scores in the 2 groups were statistically decreased compared with those before the treatment (P < 0.05 or P < 0.01). The factor scores in the combined therapy group were lower than those in the monotherapy group. The effective rate in the combination therapy group was 86.7% (26/30), and it was significantly higher than that in the monotherapy group (56.7%, 17/30), (chi2 = 6.65, P < 0.05). The doses of the drug were lower in the combination therapy group than those in the monotherapy group (t = 2.25, P < 0.05). Within six months, the relapse rate was 13.3% in the combination therapy group, and it was significantly lower than that in the monotherapy group (46.7%) (chi2 = 7.937, P < 0.025). The side effect rate was 23.3% in the combination therapy group and that was 26.7% in the monotherapy group, and there was no statistically significant difference between the two groups (P > 0.05). CONCLUSION: The combination therapy (drug combined with cognitive behavioral therapy) is effective in advanced schistosomiasis patients with depression, and it also can reduce the amount of medication and the relapse.

Glutathione-S-transferases M1 (GSTM1) and GSTT1 genotype, smoking, consumption of alcohol and tea and risk of esophageal and stomach cancers: a case-control study of a high-incidence area in Jiangsu Province, China.

To evaluate interactions between lifestyle factors and glutathione-S-transferases M1 (GSTM1) and GSTT1 genotypes with reference to development of esophageal and stomach cancers, we conducted a case-control study of 141 cases of esophageal cancer, 153 cases of stomach cancer and 223 population-based controls in Huaian City of Jiangsu Province, China. GSTM1 and GSTT1 genotypes were identified by multiplex polymerase chain reaction. The GSTM1 null genotype was associated with an increased odds ratio for esophageal cancer (2.17, 95% confidence interval=1.35-3.50), but not for stomach cancer. A combined effect was also observed between smoking and the GSTM1 null genotype with regard to esophageal risk. Tea drinking was a protective factor for both cancers, its effect being independent of the GSTT1 and GSTM1 genotypes. These findings suggest the GSTM1 polymorphism is involved in the susceptibility to esophageal cancer development, and tea consumption reduces the risk of esophageal and stomach cancers.

hOGG1 Ser(326)Cys polymorphism and modification by environmental factors of stomach cancer risk in Chinese.

Oxidative stress is involved in many types of DNA damage, e.g., resulting in 8-hydroxyguanine adducts. Since a human counterpart exists for the yeast gene OGG1 (hOGG1) encoding an enzyme that repairs 8-hydroxyguanine, its polymorphism, Ser(326)Cys, might have potential as a genetic marker for cancer susceptibility. To investigate its association with stomach cancer risk and possible interactions with environmental factors, we conducted a case-control study of 101 stomach cancer cases and 198 controls using PCR-single-strand conformation polymorphism and a questionnaire approach. The proportional distribution of the Cys/Cys alleles did not differ between stomach cancer cases and controls, but subgroup analyses revealed that a frequent drinking habit elevated the odds ratio (OR) for stomach cancer in Cys/Cys compared to Ser/Ser and Ser/Cys carriers. The ORs with frequent consumption of pickled vegetables and meat tended to be higher in Cys/Cys than in Ser/Ser and Ser/Cys carriers, these interactions being on the borderline of statistical significance. Our findings suggest that the hOGG1 Ser(326)Cys polymorphism may alter the impact of some environmental factors on stomach cancer development. For confirmation, an additional study with a larger number of subjects is now required.