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Biomedical subjects

E S Nicholls

Publications and source records attributed to E S Nicholls.

9 recordsLinked to original sources

Cardiovascular disease mortality in the Americas.

Despite subregional differences, mortality profiles have undergone major changes in most countries of the Americas. While the proportion of deaths caused by noncommunicable diseases, particularly cardiovascular diseases, has increased, overall age-adjusted mortality rates attributable to all cardiovascular disease are declining in 13 of the 15 countries selected for the present study. About half the countries showed decreasing mortality rates for ischaemic heart disease; the other half had increasing rates. The mortality rates for cerebrovascular disease and hypertensive disease declined in all but four countries. The ischaemic heart disease/cerebrovascular disease mortality ratio increased as a consequence of a greater decline in deaths due to cerebrovascular disease, except in two countries that exhibited a greater decline for ischaemic heart disease. With few exceptions the male-to-female mortality ratios increased for all cardiovascular disease, ischaemic heart disease and cerebrovascular disease, reflecting a greater decline in female mortality. In general there was a decline in all cardiovascular disease mortality for almost every age group in the North American, Southern Cone, English-speaking Caribbean, and Andean subregions, while there were increases in the Central American and Latin Caribbean subregions. The magnitude of the changes was related to the initial level of mortality and the date of onset of the decline. Change began earlier and the declines were largest in the countries with the highest initial mortality levels, whereas in the countries that initially had comparatively low values the mortality rates are still increasing. Insufficient information is available to permit elucidation of the determinants of the changes reported. There has been speculation about the possible role of factors such as demographic and sociocultural changes, changes in lifestyle and subsequently in the prevalence of risk factors for cardiovascular disease, and the increased utilization of advanced diagnostic and therapeutic technologies.

Adolescent↗

Hepatitis B follow-up among Indochinese refugees.

During 1979 and 1980 the Department of National Health and Welfare carried out a survey and later routine testing to determine the prevalence of serologic markers of hepatitis B in Indochinese refugees entering Canada. Between March and July 1981 the hepatitis-B-marker status of 220 selected refugees in the Ottawa-Hull area was reassessed. Overall, 173 (79%) of the participants had the same serologic markers when retested, but in 47 (21%) the markers had changed. The most significant changes were the loss of antigenemia in 22% of those who had been HBsAg-positive and the appearance of evidence of infection in 18% of those who had been seronegative. Most of these changes occurred among persons under 30 years of age, especially females aged 10 to 19 years.

Adolescent↗

Rabies control and management.

Since the 1950s rabies has become a familiar threat in southern Canada. Periodic outbreaks remind us how slight our control over it is. Although new vaccines such as human diploid-cell rabies vaccine have greatly improved the management of rabies in humans, true control must be sought through knowledge of the disease in or wildlife. A guide to rabies prophylaxis in humans is presented, courtesy of the National Advisory Committee on Immunization.

Animals↗

Prevalence of hepatitis B markers in Indochinese refugees.

The prevalence of hepatitis B surface antigen (HBsAg) in 14 347 Indochinese refugees was 11.6%; the rate was significantly higher (P less than 0.01) in males (14.0%) than in females (8.8%). Most of the HBsAg-positive refugees were in the age group 20 to 29 years. Antibody to HBsAg was detected in 50.9% of the males and 46.6% of the females, a significant difference (P less than 0.01). Antibody to core antigen alone was found in 2.4% of the males and 2.2% of the females. The cumulative prevalence of one or more hepatitis B markers was significantly higher (P less than 0.001) in the males (67.3%) than in the females (57.5%). The hepatitis B e antigen and its antibody were detected in 54.8% and 39.2% respectively of 1050 HBsAg-positive blood samples. The adw, adr and ayw determinants of HBsAg were found in 23%, 35% and 42% respectively of 74 samples.

Adolescent↗

Cardiovascular disease mortality in Canada.

During the past two decades approximately one half of all deaths in Canada were due to cardiovascular diseases. Ischemic heart disease and cerebrovascular disease caused more than 60% and 20% of those deaths respectively. The mortality rates for ischemic heart disease in males increased slightly until 1965 and then dropped substantially, whereas the rates for females, which were declining at least since the early 1960s, accelerated in their decline. As a consequence, the rates for males remain almost twice as high as those for females. The reductions were initially observed in males 25 to 34 years old and in all age groups of females, but became apparent in a wider range of ages in the second period reviewed (1969 through 1977). The mortality of cerebrovascular disease has gradually diminished for both sexes since the 1950s, but the decline has been more pronounced among females, who originally had the higher rate. Marked geographic differences in mortality rates still exist in Canada despite the decline in death rates for both ischemic heart disease and cerebrovascular disease in all regions of the country. Surprising regional differences in times of onset of these declines have been demonstrated. For ischemic heart disease Ontario maintains the highest and the Prairies the lowest mortality rates. Quebec, despite a sustained decline, still ranks third, while the Pacific region shows the second-lowest rates in the country. The Atlantic region showed the lowest rates of decline in the period reviewed. The reduction in the mortality of ischemic heart disease in Canada (16.4% between 1969 and 1977) must be considered real for a variety of reasons. Direct evidence is not available to elucidate whether the reduction is the consequence of reduced incidence, increased survival or a combination of the two factors. The potential role of various factors that may have contributed to this decline is briefly discussed in this article.

Adult↗