Imaging and pathological features of atypical teratoid/rhabdoid tumors in the central nervous system / 实用放射学杂志

Objective To investigate the imaging and pathological features of atypical teratoid/rhab doid tumor (AT/RT)occur-ring in the central nervous system (CNS).Methods The CT and MRI findings of 1 6 patients with CNS AT/RT were retrospectively analyzed,and their pathological and immunohistochemical results were studied.Results There were 12 males and 4 females. Tumors located is at supratentorial in 10 and infratentorial in 6.Cystic changes in tumors were noted in 12 cases.The solid portion of tumors was isointense on T2-weighted images relative to normal brain grey matter in 9 patients.Extensive peritumoral edema was observed in 1 1 lesions.The tumors showed bandlike rim of significant enhancement in 10 cases.The incidence of hemorrhage and calcification in tumors were 43.8% and 41.7% respectively.Histopathologically,AT/RT was characterized by the presence of rhab-doid cells associated with variable components of epithelial,primitive neuroectodermal and mesenchymal differentiation.Conclusion Atypical teratoid/rhabdoid tumor is several imaging findings which are relatively specific on CT and MR images.CT and MRI may provide valuable information for pre-operation diagnosis and prognostic evaluation in patients with CNS AT/RT.

An international collaborative study on influenza viruses antibody titers and contact patterns of individuals in rural and urban household of Guangzhou / 中华流行病学杂志

<p><b>OBJECTIVE</b>To describe the influenza viruses antibody levels and contact patterns of individuals in rural and urban regions of Guangzhou and to understand how contact patterns and other factors would correlate with the levels on the titers of antibody.</p><p><b>METHODS</b>"Google Map" was used to randomly select the study points from the administrative areas in Guangzhou region. Each participant was required to provide 5 ml blood serum sample to be tested against different strains of H1N1 and H3N2 influenza viruses.</p><p><b>RESULTS</b>1) Using "Google map", 50 study points were selected but only 40 study points would meet the inclusion criteria. The cohort of this study consisted 856 households with 2 801 individuals. 1 821 participants (65% of the total number individuals in the cohort) completed the questionnaires. Among the 1 821 participants, 77.3% (1 407/1 821) and 22.7% (414/1 821) of them were from rural and urban areas respectively. There were more male participants in the rural but more female participants in the urban regions. Majority of the participants were from age group 18-59 followed by group 60 with aged 2-17 the least, in both rural and urban areas. 2) 78.1% (1 423/1 821) of the participants provided their serum samples. There appeared a strong correlation between age of the participants and the strength of their antibodies against that strain when a strain first circulated. In particular, seroprevalence was the highest at the age group 2-17. 3) 'Contact' was defined as persons having physical touch or/and conversation within one meter with the participants. Participants reported all having had large number of contacts. The proportion of participants having contacts with ten persons or above was the highest, ranging from 49.8% to 72.6%, particularly in age group 6-17. Compared to weekdays, participants had fewer contact persons on weekends.</p><p><b>CONCLUSION</b>There was a strong correlation between the age of participants at the time when the strains first circulated and the seroprevalence against influenza virus strains of H1N1 and H3N2. Also, age of the participants and the frequencies of their contacts to people, was also correlated.</p>

The emergence of pandemic influenza viruses

Pandemic influenza has posed an increasing threat to public health worldwide in the last decade. In the 20th century, three human pandemic influenza outbreaks occurred in 1918, 1957 and 1968, causing significant mortality. A number of hypotheses have been proposed for the emergence and development of pandemic viruses, including direct introduction into humans from an avian origin and reassortment between avian and previously circulating human viruses, either directly in humans or via an intermediate mammalian host. However, the evolutionary history of the pandemic viruses has been controversial, largely due to the lack of background genetic information and rigorous phylogenetic analyses. The pandemic that emerged in early April 2009 in North America provides a unique opportunity to investigate its emergence and development both in human and animal aspects. Recent genetic analyses of data accumulated through long-term influenza surveillance provided insights into the emergence of this novel pandemic virus. In this review, we summarise the recent literature that describes the evolutionary pathway of the pandemic viruses. We also discuss the implications of these findings on the early detection and control of future pandemics.