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PubMed2006

A history of biological disasters of animal origin in North America.

This paper examines past occurrences in North America relevant to the possibility of biological disasters with animal origins. With respect to naturally occurring animal disease outbreaks, North America, while not as adversely affected by epizootics as other regions, has had its fair share of such outbreaks of both 'traditional' and emerging animal diseases. The traditional category includes such diseases as anthrax, classical swine fever, bluetongue, brucellosis, foot and mouth disease, and the family of equine encephalomyelitis viruses. The emerging diseases include relatively more recent culprits such as postweaning multisystemic wasting syndrome, poultry enteritis mortality syndrome, and newly discovered examples of the transmissible spongiform encephalopathies. Additionally, several serious diseases of human beings that involve animal vectors or reservoirs occur naturally in North America or have emerged in recent decades; these include plague, hantavirus, monkeypox, West Nile virus and avian-derived influenza. At the same time, there have been very few intentional attacks on livestock using biological agents and no recorded cases in North America of animals intentionally being used to transmit disease to humans. According to the historical record, therefore, naturally occurring emerging zoonoses probably constitute the greatest threat in terms of biological disasters with animal origins. However, some of the general trends in terrorist activity, such as the intensification of activities by animal rights extremists against facilities undertaking animal research, mean that the possibility of intentional animal-related biological disasters should not be discounted.

Animal Diseases↗
PubMed2005

Integrating complementary and alternative medicine into academic medical centers: experience and perceptions of nine leading centers in North America.

BACKGROUND: Patients across North America are using complementary and alternative medicine (CAM) with increasing frequency as part of their management of many different health conditions. The objective of this study was to develop a guide for academic health sciences centers that may wish to consider starting an integrative medicine program. METHODS: We queried North American leaders in the field of integrative medicine to identify initial sites. Key stakeholders at each of the initial sites visited were then asked to identify additional potential study sites (snowball sampling), until no new sites were identified. We conducted structured interviews to identify critical factors associated with success and failure in each of four domains: research, education, clinical care, and administration. During the interviews, field notes were recorded independently by at least two investigators. Team meetings were held after each visit to reach consensus on the information recorded and to ensure that it was as complete as possible. Content analysis techniques were used to identify key themes that emerged from the field notes. RESULTS: We identified ten leading North American integrative medical centers, and visited nine during 2002-2003. The centers visited suggested that the initiation of an integrative medicine program requires a significant initial outlay of funding and a motivated "champion". The centers had important information to share regarding credentialing, medico-legal issues and billing for clinical programs; identifying researchers and research projects for a successful research program; and strategies for implementing flexible educational initiatives and establishing a functional administrative structure. CONCLUSION: Important lessons can be learned from academic integrative programs already in existence. Such initiatives are timely and feasible in a variety of different ways and in a variety of settings.

Academic Medical Centers↗
PubMed2000

Structural genomics in North America.

Structural genomics in North America has moved remarkably quickly from ideas to pilot projects. Just three years ago, the field was only a concept, independently being discussed by its many inventors. Now it is already a well-organized, increasingly-funded, consortium-based effort to determine protein structures on a large scale.

Animals↗
PubMed1988

Curricular trends in North America.

Curricular changes in North America are at present being stimulated by changing disease patterns, changes in the needs of the patients attending dental schools, the desire to broaden educational experience without overloading the curriculum and overstressing the students. Curricula are changing in their content, their format, in the methodology used and in the targets that students are set. The evaluation of curricula and the planning of change are processes that are themselves undergoing revision.

Clinical Competence↗
PubMed2000

An abbreviated history of orthopaedic oncology in North America.

Orthopaedic oncology in North America has its roots in European medicine of the 1800s where sarcomas were first classified on the basis of their gross characteristics (1804) and amended on the basis of their histologic features (1867). Surgical treatment, local excision, with unacceptable mortality led to amputation in the 1870s and remained so until limb-sparing resection was cautiously embarked on in the mid-1900s. Nonsurgical adjuvant therapy was first devised in the 1880s (as Coley's toxins) but remained largely ineffective until the advent of chemotherapy in the 1970s. The combination of these techniques in the past 30 years, and the vastly improved staging and reconstructive techniques has led to the current preponderance of limb-salvaging surgery and greatly improved survival rates. The application of these treatments has been enhanced by the development of orthopaedic oncology fellowships, orthopaedic oncology societies, and federally funded regional cancer centers and multidisciplinary teams to treat patients with sarcomas.

Bone Neoplasms↗
PubMedDate not supplied

Pulmonary rehabilitation program survey in North America, Europe, and Tokyo.

PURPOSE: To study a comparison of problems arising in pulmonary rehabilitation programs in North America, Europe, and Tokyo. METHODS: The survey instrument was a 13-item questionnaire sent in December 1994 to institutions in North America (n = 178), Europe (n = 179), and Tokyo (n = 399). RESULTS: Response rates were 51%, 40%, and 51% for North America, Europe, and Tokyo, respectively. Pulmonary rehabilitation programs were available at 56% of hospitals in North America and 74% in Europe, but at only 20% of hospitals in Tokyo. Most PRPs were conducted in an outpatient setting in North American (98%), whereas both outpatient (55%) and inpatient programs (65%) were adopted in Europe. Although the type of lung disease for which patients in both North America and Europe were referred to PRPs was mainly chronic obstructive pulmonary disease, this accounted for only 34% of referrals in Tokyo. However, referrals for primary tuberculosis sequelae (P = 0.028) and bronchiectasis (P = 0.021) were more common in Europe, similar to the situation in Tokyo. The following PRP items were available at significantly higher rates in North America than in Europe, and most were unavailable in Tokyo: family education, psychological support, nutritional instruction, treadmill, bicycle ergometer, walking training, and increasing the activity of daily living. CONCLUSION: Pulmonary rehabilitation programs in North America are more multidimensional. However, target diseases differ among North America, Europe, and Tokyo. Pulmonary rehabilitation programs in Tokyo differed from those in North America and Europe and were poorly programmed. Problems arising in PRPs in the three regions include lack of staff and insufficient reimbursement.

Canada↗
PubMed2002

A dynamic mass budget for toxaphene in North America.

A continental-scale dynamic mass budget for toxaphene in North America is presented, based on available information on physicochemical properties, usage patterns, and reported environmental concentrations and using the Berkeley-Trent North American mass balance contaminant fate model (BETR North America). The model describes contaminant fate in 24 ecological regions of North America, including advective transport between regions in the atmosphere, freshwater, and near-shore coastal water. The dynamic mass budget accounts for environmental partitioning, transport, and degradation of the estimated 534 million kg of toxaphene that were used in North America as an insecticide and piscicide between 1945 and 2000. Satisfactory agreement exists between model results and current and historically reported concentrations of toxaphene in air, water, soil, and sediments throughout North America. An estimated 15 million kg of toxaphene are believed to remain in active circulation in the North American environment in the year 2000, with the majority in soils in the southern United States and Mexico, where historic usage was highest. Approximately 70% of total toxaphene deposition from the atmosphere to the Great Lakes is attributed to sources outside the Great Lakes Basin, and an estimated total of 3.9 million kg of toxaphene have been transported to this region from other parts of the continent. The toxaphene mass budget presented here is believed to be the first reported continental-scale multimedia mass budget for any contaminant.

Agriculture↗
PubMed1996

Acceptance of Surgery for Obesity by Academic Surgeons in North America.

BACKGROUND: Have surgeons in North America accepted operations for the treatment of severe obesity? This question was posed by organizers of the Ninth International Symposium on Obesity Surgery that met in Stockholm in September, 1995. Study design: In order to obtain opinions which might help to answer the question posed, a 1-page questionnaire was sent to 151 chairmen of academic departments of surgery in North America in December 1994 asking about the acceptance and use of surgical operations for the treatment of severe obesity. RESULTS: Answers, received from 112 or 74%, indicated that operative treatment should be used (74%), was effective (77%) and safe (71 %). However, only 65% of departments provided such operations. Operative treatment for obesity was available outside the department in 53%. The operations most frequently used were Roux-en-Y gastric bypass (RGB) and vertical banded gastroplasty (VBG). A single operation was offered by 44 departments and a choice of two or more operations in 30 departments. RGB and VBG were equally in use. Gastric banding was used as an alternative to VBG in six departments. Other operations were in use in six departments either alone (three) or as alternatives to RGB and VBG (three). CONCLUSIONS: It appears that surgical treatment of obesity is accepted and available in the majority of academic departments of surgery.

Journal Article↗
PubMed2005

Changes in the epidemiology of thalassemia in North America: a new minority disease.

OBJECTIVE: Changing patterns of immigration to North America, along with improved treatment, have altered the clinical spectrum of thalassemia, one of the world's most common genetic diseases. The new demography of the disease, with its widely variable phenotypes, has implications for its diagnosis, counseling, and management. Characterization of the new spectrum of this ancient disease, now predominated by minority groups, is essential for optimizing survival. METHODS: The National Institutes of Health-sponsored North American Thalassemia Clinical Research Network (TCRN) conducted a cross-sectional study of 721 patients with thalassemia syndromes. A detailed chart review was undertaken to define the relationships between ethnic origins, genotype, and phenotype. These results were compared with 3 previous surveys of similar regions. To determine if the TCRN patient epidemiology is representative of North American patients, 87 additional programs were reviewed, and hemoglobinopathy programs from the 2 largest thalassemia regions, Ontario and California, were analyzed. RESULTS: A total of 721 patients completed analysis in the TCRN study, including 389 (54%) patients with beta-thalassemia major, 105 (15%) patients with beta-thalassemia intermedia, 95 (13%) patients with hemoglobin E-beta-thalassemia, and 132 (18%) patients with alpha-thalassemia. beta-Thalassemia predominated in Eastern North America. Hemoglobin E-beta-thalassemia and alpha-thalassemia were common on the Western continent. Genotype broadly correlated with the clinical phenotype. However, there was marked heterogeneity in clinical phenotype among patients with similar globin mutations. In beta-thalassemia disorders, coinheritance of the alpha-thalassemia trait, triplication of alpha-thalassemia genes, and heterozygosity for the dominant beta-thalassemia allele affected the clinical phenotype. In alpha-thalassemia disorders, structural mutations such as hemoglobin H-Constant Spring resulted in a severe hemoglobin H phenotype. Sixty percent of patients received regular transfusions, and 86% received regular iron-chelation therapy. Increased survival and decreasing birth rates of Mediterranean patients resulted in an aging Greek/Italian population being replaced by a young Asian/Middle Eastern population. Now, Asian patients account for >50% of the thalassemia population. Evidence of increasing survival is reflected in an advancing mean age of white patients with thalassemia major (25 years, up from 11 years in 1974). The results of the non-TCRN thalassemia survey confirm these observations and describe a young multiethnic thalassemia population distributed throughout North America. Newborn-screening results suggest that thalassemia births in North America are increasing and reflect the change in genotype and phenotype observed in the TCRN populations. CONCLUSIONS: The epidemiology of thalassemia in North America reflects a heterogeneous group of diseases with new ethnicities, genotypes, and phenotypes. In these communities, physicians will need to provide education, prenatal diagnosis, counseling, and management of this newly diverse group of patients.

Adolescent↗
PubMed2006

Skin chemistry of nudibranchs from the west coast of North America.

The Pacific coastline of North America extends from Alaska in the north to Panama in the south. Chemical studies of skin extracts from nudibranchs collected along this coast have resulted in the isolation of over 100 chemically diverse secondary metabolites. The majority of the compounds are terpenoids, but polyketides, steroids, and alkaloids have also been found. Observations of geographic variation in metabolite content and stable isotope-feeding experiments have provided information about the de novo biosynthetic or dietary sequestration origins of the skin extract metabolites.

Animals↗
PubMed1999

Colonization history and introduction dynamics of capsella bursa-pastoris (Brassicaceae) in north america: isozymes and quantitative traits

Multilocus isozyme genotypic composition for aspartate aminotransferase (AAT), leucine aminopeptidase (LAP) and glutamate dehydrogenase (GDH) was studied for Capsella in the source continent, Europe (9000 plants from 593 populations), and in the colonized continent, North America (2700 plants from 88 populations). North America was depauperate in the number of genotypes (by approximately 50%), but in terms of frequencies, a few genotypes were common and shared by both continents. Although some, very rare, genotypes were, however, unique for North America, our data provided no evidence to indicate that the introduced gene pools were reconstructed on a multilocus genetic basis after introduction. Instead, they argued for a considerable number of independent introduction events. Geographical distribution patterns of multilocus genotypes in Europe and North America were pronounced and enabled us to trace the colonization history of Californian Capsella back to Spanish ancestral populations and those of temperate North America back to temperate European gene pools. A random-block field experiment with 14 Californian populations from different climatic regions revealed that variation patterns of quantitative traits reflect ecotypic variation, and the ecological amplitude of Capsella in North America is similar to that in Europe, which can be traced back to the introduction of preadapted genotypes. It appears that certain multilocus isozyme genotypes are associated with certain ecotypes. The variable European gene pool of Capsella was essentially introduced into North America without major genetic changes.

Journal Article↗
PubMed1975

The frequency of contact sensitivity in North America 1972-74.

Three thousand subjects in North America were patch-tested with 19 allergens. The most frequent sensitizers observed include nickel sulfate, caine mixture, potassium dichromate, balsam of Peru, thimerosal, ethylenediamine hydrochloride, paraphenylenediamine and thiram. The prevalence data compared with an earlier study indicates that the initial allergens reported warrant their continued inclusion in a routine patch test screening series in North America.

Balsams↗
PubMed2004

Seed dispersal by white-tailed deer: implications for long-distance dispersal, invasion, and migration of plants in eastern North America.

For many plant species in eastern North America, short observed seed dispersal distances (ranging up to a few tens of meters) fail to explain rapid rates of invasion and migration. This discrepancy points to a substantial gap in our knowledge of the mechanisms by which seeds are dispersed long distances. We investigated the potential for white-tailed deer ( Odocoileus virginianus Zimm.), the dominant large herbivore in much of eastern North America, to disperse seeds via endozoochory. This is the first comprehensive study of seed dispersal by white-tailed deer, despite a vast body of research on other aspects of their ecology. More than 70 plant species germinated from deer feces collected over a 1-year period in central New York State, USA. Viable seeds included native and alien herbs, shrubs, and trees, including several invasive introduced species, from the full range of habitat types in the local flora. A mean of >30 seeds germinated per fecal pellet group, and seeds were dispersed during all months of the year. A wide variety of presumed dispersal modes were represented (endo- and exozoochory, wind, ballistic, ant, and unassisted). The majority were species with small-seeded fruits having no obvious adaptations for dispersal, underscoring the difficulty of inferring dispersal ability from diaspore morphology. Due to their broad diet, wide-ranging movements, and relatively long gut retention times, white-tailed deer have tremendous potential for effecting long-distance seed dispersal via ingestion and defecation. We conclude that white-tailed deer represent a significant and previously unappreciated vector of seed dispersal across the North American landscape, probably contributing an important long-distance component to the seed shadows of hundreds of plant species, and providing a mechanism to help explain rapid rates of plant migration.

Animals↗
PubMed2006

Intercontinental biogeography of subfamily Orontioideae (Symplocarpus, Lysichiton, and Orontium) of Araceae in Eastern Asia and North America.

Symplocarpus, Lysichiton, and Orontium (Orontioideae) are three of the few north temperate genera of the primarily tropical Araceae. Symplocarpus is disjunctly distributed in eastern Asia (3 spp.) and eastern North America (1 sp.); Lysichiton has an intercontinental discontinuous distribution in eastern Asia (1 sp.) and northwestern North America (1 sp.); and the monotypic Orontium is restricted to eastern North America. Phylogenetic analysis of the trnL-F and ndhF sequences supports (1) the monophyly of both Symplocarpus and Lysichiton, (2) the sister-group relationship of Symplocarpus and Lysichiton, and (3) the clade of Orontium, Symplocarpus, and Lysichiton. Although Symplocarpus shows a much wider disjunction than Lysichiton, the estimated divergence time of the former [4.49+/-1.69 or 6.88+/-4.18 million years ago (mya)] was similar to that of the latter (4.02+/-1.60 or 7.18+/-4.33 mya) based on the penalized likelihood and the Bayesian dating methods, respectively. Eastern Asia was suggested to be the ancestral area of the Symplocarpus-Lysichiton clade based on the dispersal-vicariance analysis. Our biogeographic results support independent migrations of Symplocarpus and Lysichiton across the Bering land bridge in the late Tertiary (Pliocene/late Miocene). Fossil evidence suggests Orontioideae dated back to the late Cretaceous in the temperate Northern Hemisphere (72 mya). The relative rate test shows similar substitution rates of the trnL-F sequences between the proto and the true aroids, although the latter has substantially higher species diversity. The proto Araceae perhaps suffered from a higher rate of extinction in the temperate zone associated with periods of climatic cooling in the Tertiary.

Animals↗
PubMed2004

Lyme borreliosis in Europe and North America.

Since the discovery of the Lyme disease spirochete in North America in 1982 and in Europe in 1983, a plethora of studies on this unique group of spirochetes that comprise Borrelia burgdorferi sensu lato has been accumulated. In an attempt to compare and contrast Lyme borreliosis in Europe and North America we have reviewed the biology of the aetiologic agents, as well as the clinical aspects, diagnosis and treatment of this disease on both continents. Moreover, we have detailed the ecology of the Ixodes ticks that transmit this infection and the reservoir hosts that maintain the spirochete cycle in nature. Finally, we have examined the transmission dynamics of the spirochete on both continents, as well as the available prevention strategies. Although it has been over two decades since the discovery of the Lyme disease spirochete, Lyme borreliosis is an expanding public health problem that has defied our attempts to control it. By comparing the accumulated experience of investigators in North America and Europe, where the disease is most frequently reported, we hope to advance the cause of developing novel approaches to combat Lyme borreliosis.

Animals↗
PubMed2002

A multicenter evaluation of linezolid antimicrobial activity in North America.

Overall, 141 centers in North America enrolled in this international surveillance study designed to evaluate the in vitro antimicrobial activity and spectrum of linezolid, a new oxazolidinone. Each participant tested the susceptibility of clinical isolates of staphylococcal species (n = 85) against 12 drugs, and enterococcal species (n = 40) against 6 drugs using reference broth microdilution trays; and of streptococcal species (n = 25) against 6 drugs using Etests (AB BIODISK, Solna, Sweden). Quality control testing was conducted using recommended strains, and verification of resistance to linezolid and select other agents was performed by a regional monitor. Of the 20,161 isolates collected from sites across the United States (US; n = 132) and Canada (n = 9), 18,307 were included in this analysis. Oxacillin resistance occurred in 38.7 and 70.6% of Staphylococcus aureus and coagulase-negative staphylococcal (CoNS) isolates, respectively. Vancomycin resistance was reported in 65.9 and 2.6% of Enterococcus faecium and E. faecalis, respectively. Penicillin resistance occurred in 37.2% of Streptococcus pneumoniae, 17.5% constituting high-level resistance (MIC, > or =2 microg/ml). The MIC(90) for linezolid was 1 microg/ml for streptococci, 2 microg/ml for enterococci and CoNS isolates, and 4 microg/ml for S. aureus. Using the US FDA-recommended susceptible breakpoints for linezolid, there were no confirmed reports of linezolid resistance (i.e., MIC > or =8 microg/ml). The occurrence of linezolid MICs was unimodal and generally varied between, 1-4 microg/ml for staphylococci (94% of recorded results), 1-2 microg/ml for enterococci (93%), and 0.5-1 microg/ml for streptococci (85%). Susceptibility to linezolid was not influenced by susceptibility to other antiicrobials such as vancomycin, beta-lactams or macrolides. Only linezolid was universally active against essentially all tested Gram-positive specimens. The unimodal susceptibility pattern is indicative of excellent and near complete activity against key Gram-positive pathogens including multiply resistant strains, but surveillance for emerging resistances (rare) and the performance of routine susceptibility tests to guide patient therapy seems prudent.

Acetamides↗
PubMed2000

Gene flow and genetic diversity: a comparison of freshwater bryozoan populations in Europe and North America.

We have used microsatellite and mitochondrial sequence data to gain insight into patterns of gene flow and genetic diversity among North American and European populations of the freshwater bryozoan Cristatella mucedo. Mitochondrial sequence data reveal numerous, widely distributed, divergent genetic lineages in North America that can be broadly categorized into two groups, one of which is genetically homogeneous and relatively similar to the European haplotypes, the other of which is more diverse. The maximum North American sequence differentiation translates into a divergence time of approximately 1.5 Myr BP. In contrast, European populations contained only three haplotypes that are all closely related. Microsatellite data reveal higher overall levels of genetic diversity in North America than Europe, although levels of within-population genetic variation are similar on the two continents. In North America, two of the three microsatellite loci show bimodal distributions of allele sizes which are significantly associated between the two loci. As a result, two microsatellite lineages are evident, and these are assortatively distributed between the mitochondrial haplotype groupings. The combined mitochondrial and microsatellite data suggest two distinct genetic lineages in North America that may represent cryptic species. Hybridization between the two presumptive species or subspecies may have contributed to the high levels of genetic diversity in North America. The overall lower levels of genetic diversity in Europe can be attributed to postglacial derivation of extant populations from a single mitochondrial lineage, and conformation to a metapopulation structure.

Animals↗
PubMed1993

The systematics of nematodes that cause ostertagiasis in domestic and wild ruminants in North America: an update and a key to species.

Studies of medium stomach worms (Subfamily Ostertagiinae) of domestic and wild ruminants in North America have refined our understanding of the systematics, host distribution and biogeography of these nematodes. Strong support for recognition of monophyly for the Ostertagiinae has resulted from preliminary phylogenetic analyses of morphological characters among these and other trichostrongylids. Evaluation of morphological and biochemical characters in our laboratory and elsewhere has not refuted the polymorphism hypothesis where paired major and minor morphotypes are postulated to represent polymorphic species within the genera Ostertagia (Ostertagia ostertagi/Ostertagia lyrata; Ostertagia leptospicularis/Ostertagia kolchida; Ostertagia gruehneri/Ostertagia arctica; Ostertagia mossi/Ostertagia dikmansi), Teladorsagia (Teladorsagia circumcincta/Teladorsagia trifurcata (= Teladorsagia davtiani), and Marshallagia (Marshallagia marshalli/Marshallagia occidentalis). The minor morphotype of Ostertagia bisonis, recognized in Eurasia (considered to be Teladorsagia kazakhstanica), has yet to be discovered in North America. The taxonomy of these species has remained stable since an earlier overview of Ostertagia spp. and Teladorsagia spp. in North American domestic stock at the 1986 Ostertagia Workshop. Investigations since 1986 have focused on comparative morphology and the clear differentiation of Ostertagiinae, primarily from wild ruminants, that have been reported or may potentially occur in domestic bovids. Among these are species which infect wild and domestic sheep (Marshallagia marshalli/Marshallagia occidentalis), bovids (Ostertagia bisonis), and cervids (Ostertagia mossi/Ostertagia dikmansi, Ostertagia leptospicularis/Ostertagia kolchida, Ostertagia gruehneri/Ostertagia arctica, Mazamastrongylus odocoilei and Mazamastrongylus pursglovei) in North America. A key is presented for identifying 15 species of the Subfamily Ostertagiinae that are parasitic in domestic and wild ruminants of North America. Four exotic species (Camelostrongylus mentulatus, Spiculopteragia spiculoptera (= Spiculopteragia boehmi), Spiculopteragia asymmetrica and Longistrongylus curvispiculum) have been reported in North America, but only in game farms and are not included in the key. Hyostrongylus rubidus, a member of the Ostertagiinae normally parasitic in pigs and only rarely reported from domestic ruminants, is not included in the keys. Additional data from comparative morphology and molecular analyses will promote a reassessment of the generic-level systematics of the Ostertagiinae and allow an evaluation of host-parasite evolution and historical biogeography.

Animals↗