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At least 919 records · Page 51Linked to original sources
PubMed2005

Vitamin D insufficiency in North America.

Vitamin D insufficiency is a term that has been used to describe the finding of biochemical evidence of deficiency, without obvious clinical signs or symptoms, such as rickets or osteomalacia. The condition is most commonly diagnosed by a serum 25-hydroxyvitamin D below 40 nmol/L (16 microg/L). This paper reviews North American studies addressing the prevalence of the problem, and the growing body of evidence that vitamin D insufficiency predisposes individuals to poor bone and muscle health. The term insufficiency is somewhat misleading, as patients with this condition are really just part of the spectrum of vitamin D deficiency. If the more generous definition of this condition is used (serum 25-hydroxyvitamin D < 80 nmol/L), a much larger proportion of the population has the problem. The response to vitamin D supplementation in clinical trials suggests current recommendations for dietary intake of this vitamin are too low and that a higher adequate intake should be recommended.

Adult↗
PubMed1980

[Lung cancer mortality and cigarette smoking in Europe, North America, Japan, and Australia: regional differences and chronological development].

Trends and regional differences in lung cancer mortality and cigarette smoking are examined for 26 developed countries. "In 1975, lung cancer mortality figures for females aged 55 to 64 years...showed 12 to 60 deaths per 100,000 inhabitants, for males 60 to 270 deaths. In nearly all countries the mortality rates of males have been increasing since 1958.... For females the rise in lung cancer mortality is particularly steep...." An increase in cigarette smoking between 1935 and 1973 is also noted, and it is found that "the ranking of the countries by cigarette consumption essentially corresponds to that by lung cancer mortality." (summary in ENG)

Americas↗
PubMed2005

Update on pediatric perfusion practice in North America: 2005 survey.

The devices and techniques used for pediatric cardiopulmonary bypass (CPB) undergo continuous change. New techniques and clinical comparisons of devices are frequently reported in the literature; however, information about the extent to which these techniques and devices are adopted into clinical practice at pediatric heart centers are not well described. We conducted a mail survey of North American pediatric cardiac surgery centers to gain perspective on the extent to which various devices and techniques were used for CPB along with program demographic data. In January 2005, surveys were mailed to 180 North American open heart centers. The survey was nearly identical in format and content to three earlier surveys completed in 1989, 1994, and 1999, with the exception that new questions were added to address new techniques and devices that have emerged over the years. Responses were received from 76 hospitals, for an overall response rate of 42%. Of the responding centers, 53 were performing pediatric open heart surgery and 23 were not. Twenty centers performed only pediatric open heart surgery, and 33 performed both pediatric and adult open heart surgery. The mean pediatric annual caseload of responding centers was 195 procedures/yr (range, 20-650 procedures/yr; median, 154 procedures/yr). A total of 9943 pediatric open heart procedures were performed at responding centers in 2004. Most of the centers surveyed reported use of an open venous reservoir system (88%), use of roller pumps (90%), and use of arterial line filtration (98%). Most centers used circuits that have surface treatments with heparin or some other surface-modifying agent (74%). There has been an increase in the use of all types of safety devices. Modified ultrafiltration is used at 75% of the centers surveyed. Centers reported an increase in the availability of all types of cardiac support devices including extracorporeal membrane oxygenation for postcardiotomy cardiac support (90%). This survey provides an overview of clinical practice in 2004. The series of surveys document the historical progression of clinical practice over the past 16 years. Practice surveys may also be useful for identifying gaps between evidence-based knowledge and clinical practice. These surveys document the diffusion of innovation related to CPB during the past 16 years and areas of variation in practice that need further study.

Adult↗
PubMed2005

Postglacial expansion of the southern red-backed vole (Clethrionomys gapperi) in North America.

Dynamic climatic oscillations of the Pleistocene dramatically changed the distributions of high latitude species. Molecular investigations of a variety of organisms show that processes of postglacial colonization of boreal regions were more complex than initially thought. Phylogeographical and coalescent analyses were conducted on partial sequences of the cytochrome b gene (600 bp) from 64 individuals of Clethrionomys gapperi from North Carolina, Pennsylvania, Minnesota, Idaho, Washington, British Columbia, Northwest Territories, and Alaska to test hypotheses relating to Pleistocene refugia and postglacial colonization routes. Three divergent clades (east, west, central) were identified with highest net divergence (dA = 5.2%) between the eastern and western clades. Populations from the recently deglaciated higher latitudes of Canada and Alaska are closely related to lower latitude populations of the central clade (dA = 1.2%) suggesting recent expansion from this midwestern region. No representatives from the east or west clade were found at latitudes higher than 50 degrees N, indicating that postglacial colonization occurred through a midcontinental route. The high latitude population from the Northwest Territories exhibited demographic patterns and genetic diversity consistent with a stable noncolonizing population. This population is found near the Mackenzie range, where the two continental ice sheets were believed to have coalesced. Molecular variation observed in this population may be the result of leading edge population diversifying in the continental corridor or may reflect the signal of a high latitude refugial population.

Animals↗