Objective To observe the dynamic changes of prevalence of Keshan disease (KD) in Hebei province from 1990 to 2007, to provide scientific basis for its prevention and treatment. Methods The surveillance data of KD was analyzed according to "the National Scheme of KD Surveillance and the Surveillance of KD" (W/T 78-1996) in Hebei province from 1990 to 2007 by the Institute for Prevention of Endemic Disease in Hebei Province Center for Disease Control and Prevention. The data included physical examination, electrocardiogram (ECG), the chest X-ray film of KD patients and the suspected patients, as well as selenium contents of hair collected in 1990, 1992 and 1999. Results No new cases of acute and subacute types of KD patients were found at the surveillance sites from 1990 to 2007. Thirty-five cases of new latent KD and one case of spontaneous chronic KD were identified respectively. Prevalence of chronic and latent KD ranged from 1.12% (8/713) to 8.18% (27/330) and 2.29% (19/831) to 8.20% (45/549) in Hebei province from 1990 to 2007, respectively. The prevalence of KD in children aged 3 - 14 years old and childbearing woman aged 20 - 45 years old decreased year by year, however population over 45 years old were more likely suffering from KD. The major abnormal changes of ECG in KD) patients were complete fight bundle branch block, ST-T change frequent premature ventricular contraction, and left anterior faseicular block. The prevalence of the heart enlargement in KD patients was 47.00% (211/449) averagely, and the prevalence of heart enlargement of medium grade increased remarkably after 2005 [28.57%(8/28) - 48.39%(15/31)]. The average mortality in chronic KD patients was 18.0%(18/100) from 1990 to 2007. Conclusions The prevalence of KD decreased slowly in Hebei province. Hebei province is still the region with higher prevalence of KD around the country, and the tasks of prevention and treatment of KD is still urgent. Enhancing the surveillance of of KD and carrying out management and treatment of KD patients should be emphasized in the future.

Objective To explore the regularity of time-dependent changes in morphology and biomechanical properties of brain tissues in pigs,and value the feasibility of deducing the postmortem interval (PMI).Methods Brain tissues were taken from 42 pigs and kept in an artificial climate chamber with the temperature of 25 ℃ and humidity of 75％.The samples were collected from telencephalon at sequential time intervals (0,12,24,36,48,60 h;n =6) according to the principle of predefined time,position,direction,ratio,quantity and shape.The samples fixed with formaldehyde were then immediately tested by mechanical testing machine to obtain their biomechanical parameters and the histological sections were prepared.Results With the extension of PMI (0-60 h),brain tissues gradually became discolored,weak,mudding and liquefied under the influence of autolysis and putrefaction.Both clearance area of the white matter and its integrated optical density (IOD) significantly increased during 0-48 h.Biomechanical properties of brain tissues including the limit load,average force,elastic modulus and fracture energy all presented a declining tendency at the interval of 12-60 h.The limit load was considered highly statistically significant,and statistical differences were found in average force,elastic modulus and fracture energy.Conclusions There exists a significantly negative structure-activity relationship between the morphology of brain tissues and biomechanical properties.The limit load of postmortem brain tissues in 60 h is the optimum in the window period,which can be used as a new method for estimating PMI.

Objective To evaluate the effectiveness of health education on iodine deficiency disorders (IDD) in Hebei, and to provide basic information for development of control strategies. Methods A total of 34 project counties were selected in Hebei province, and 3 townships were chosen in each project county. Heath educational activities were carried out in the classes of grade 5 in the central primary school of each selected township. In the meantime, 3 villages were chosen in each selected township where the health education for women of childbearing age in the community was carried out. Sureys on knowledge of IDD control were conducted in the 34 project counties before and after the health educational activities. Results The knowing rates of IDD control among pupils in all 34 project counties increased from 71.10%(7835/11 019) to 94.84%(10 840/11 430) after health education, with a average increase of 23.74%. The knowing rates of IDD control among housewives increased from 77.02%(4531/5883) to 95.32%(5902/6192), with a average increase of 18.30%. Of which, the knowing rates of IDD control among pupils in Hengshui city increased from 55.56% (750/1350) to 94.89% (1281/1350),with a average increase of 39.33%. The knowing rates of IDD control among housewives in Handan city increased from 65.68%(532/810) to 96.50%(909/942), with a average increase of 30.82%. Conclusions The knowing rates of IDD control among pupils and housewives are remarkably increased after implementing the health education projects. They have better life and health habits, and the project achieves desired effect.

Objective To assess the therapeutic effect of gamma knife radiosurgery for residual tumors after surgical resection of hemangioblastoma in children. Methods The clinical data were retrospectively analyzed in 9 children who received gamma knife radiosurgery for the residual tumors after a previous surgery for hemangioblastoma resection. Results The 9 children were followed up for 12-48 months, and 6 children showed a tumor volume reduction by over 50% with obviously improved clinical symptoms. One child showed no response to the treatment and received a second gamma knife radiosurgery. In 2 children, the tumor volume increased progressively after the radiosurgery, and a second radiosurgery was performed in 1 case and open surgery in the other. Conclusion Gamma knife radiosurgery is safe and effective for treatment of the residual tumors in children with previous surgical resection of hemangioblastoma.