Zong Xing Zhang

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Comparison of Parkinson's disease (PD) prevalence and incidence in various parts of the world is difficult because methods of case ascertainment, diagnostic criteria, classification, medical facilities, and age distribution of the populations vary broadly in different studies. We minimized these differences by adjusting available data to a single standard(More)
Mortality attributed to multiple sclerosis (MS) was analyzed for 35 countries around the world using World Health Organization reports from 1965 to 1984. Trends were plotted for the United States and Canada, for various regions of Europe, Israel, South America, Asia, Australia and some Pacific countries. In general, MS mortality has declined steadily in(More)
Average annual age-adjusted incidence rates of parkinsonism-dementia complex were obtained for the 19 election districts of Guam from 1956 through 1985. The highest rates were found in the southern and central districts, and the lowest rates were found in the northern and western districts. Geographic and temporal patterns of incidence were associated with(More)
Comparison of stroke incidence in various parts of the world is difficult because differences in diagnostic criteria, medical facilities and age-sex distributions are often not taken into account. We calculated age-sex standardized incidence ratios (SIR) of stroke in 37 regions based on recent reports. The USA (1976) was taken as the standard population. In(More)
OBJECTIVE To evaluate the performance of vaporized hydrogen peroxide (VHP) for the bio-decontamination of the high efficiency particulate air (HEPA) filter unit. METHODS Self-made or commercially available bioindicators were placed at designated locations in the HEPA filter unit under VHP fumigation. The spores on coupons were then extracted by 0.5 h(More)
For 1944 through 1985, documented clinical descriptions compatible with a diagnosis of parkinsonism-dementia complex were found in 363 Chamorros (including mixed Chamorros) and three Filipino immigrants who had lived on Guam before onset. Downward trends in age-adjusted incidence rates and upward trends in age at onset were seen for Chamorros of both sexes.(More)
Using a case registry, we investigated the temporal occurrence of motor neuron disease (MND) on Guam. MND with onset during 1941-85 was documented in 434 Chamorros and 9 non-Chamorro migrants who had lived on Guam before onset. Increased median age at onset and decreased age-adjusted incidence rates (since the early 1960s) were observed for Chamorros of(More)
A cross-sectional epidemiological study was conducted to assess the prevalence and etiology of mental retardation (MR) among children under 14 years of age. The definition of MR and the criteria for diagnosis were adopted from WHO (1985). The IQ/DQ was evaluated with standardized psychological tests. The etiology of MR was specified by medical, genetic and(More)
We investigated the geographic and familial occurrence of motor neuron disease (MND) on Guam, and then considered etiologic hypotheses related to cycad use and metal intoxication. The research was based on 303 Chamorros from Guam and 3 Chamorros from other Mariana Islands, all with MND onset on Guam during 1956-85. Inarajan and Umatac, two southern(More)
We investigated the seasonal pattern of stroke using the Lehigh Valley Stroke Register. This register includes all patients hospitalized with stroke or transient ischemic attack (TIA) from among the 600,000 Lehigh Valley residents. Meterological data were obtained from the National Oceanic and Atmospheric Administration. The study, which uses 18 months of(More)