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PubMed2005

Genome analysis of Cryphonectria hypovirus 4, the most common hypovirus species in North America.

Many different viruses that reduce virulence and alter the phenotype to varying extents have been identified in the chestnut blight fungus Cryphonectria parasitica. Most viruses identified in this fungus fall within the Hypoviridae family of positive-sense RNA viruses, which contains one genus and four species. Different species predominate in different geographic locations in chestnut-growing areas around the world. In this paper, we describe the genome organization and some variants of Cryphonectria hypovirus 4 (CHV-4), the species most commonly found in eastern North America. CHV-4 is distinguished from other hypoviruses by having little effect on fungal virulence and colony morphology. The 9.1-kb genome of strain CHV-4/SR2 is the smallest of any member of the family characterized to date. Like the recently characterized species CHV-3, a single ORF was predicted from deduced translations of CHV-4/SR2. Sequence analysis revealed the presence of a putative glucosyltransferase domain in both CHV-4 and in CHV-3, but no such homolog was detected in the more thoroughly examined CHV-1 or in CHV-2. Alignments with 8 other CHV-4 isolates from different regions of eastern North America revealed sequence diversity within the species and the likelihood that RNA recombination has led to this diversity.

Ascomycota↗
PubMed2002

Post-glacial colonization of northwestern North America by the forest-associated American marten (Martes americana, Mammalia: Carnivora: Mustelidae).

Phylogeographic patterns were used to assess intraspecific diversification of American martens (Martes americana). Within martens, two morphological groups (americana and caurina) have been recognized, though the level of distinction between them has been debated. We examined mitochondrial cytochrome b gene haplotypes from 680 martens to explore the colonization history of the Pacific Northwest and found two clades that correspond to the morphological groups. The widespread americana clade extends from interior Alaska south to Montana and eastward to Newfoundland and New England (i.e. northwestern, north-central and northeastern North America). The caurina clade occurs in western North America, minimally extending from Admiralty Island (southeastern Alaska) south to Oregon and Wyoming. Our data indicated two colonization events for the Pacific Northwest (one by members of each clade) and were consistent with the persistence of populations throughout past glacial periods in eastern and western refugia. Due to vegetational and geological history following the past deglaciation, we hypothesize that martens of the caurina clade spread along the North Pacific Coast, and into southeastern Alaska, earlier than martens of the americana clade. Mismatch distributions for the americana clade were indicative of populations that recently experienced demographic expansion, while mismatch distributions for the caurina clade suggested that populations were at equilibrium. These clades are reciprocally monophyletic and distinctive (interclade divergence ranged from 2.5 to 3.0% (uncorrected p), whereas, intraclade divergence was < 0.7%), and two regions of sympatry have been identified. Genetic signatures of past admixture in hybrid zones may have been extinguished during subsequent glacial periods when ranges contracted. This recurrent pattern of relatively restricted western, or Pacific coastal, lineages and more widespread eastern, or interior continental, lineages exists across broad taxonomic groups and suggests a shared biogeographical history.

Animals↗
PubMed2004

Myxobolus cerebralis internal transcribed spacer 1 (ITS-1) sequences support recent spread of the parasite to North America and within Europe.

Molecular approaches for resolving relationships among the Myxozoa have relied mainly on small subunit (SSU) ribosomal DNA (rDNA) sequence analysis. This region of the gene is generally used for higher phylogenetic studies, and the conservative nature of this gene may make it inadequate for intraspecific comparisons. Previous intraspecific studies of Myxobolus cerebralis based on molecular analyses reported that the sequence of SSU rDNA and the internal transcribed spacer (ITS) were highly conserved in representatives of the parasite from North America and Europe. Considering that the ITS is usually a more variable region than the SSU, we reanalyzed available sequences on GenBank and obtained sequences from other M. cerebralis representatives from the states of California and West Virginia in the USA and from Germany and Russia. With the exception of 7 base pairs, most of the sequence designated as ITS-1 in GenBank was a highly conserved portion of the rDNA near the 3-prime end of the SSU region. Nonetheless, the additional ITS-1 sequences obtained from the available geographic representatives were well conserved. It is unlikely that we would have observed virtually identical ITS-1 sequences between European and American M. cerebralis samples had it spread naturally over time, particularly when compared to the variation seen between isolates of another myxozoan (Kudoa thyrsites) that has most likely spread naturally. These data further support the hypothesis that the current distribution of M. cerebralis in North America is a result of recent introductions followed by dispersal via anthropogenic means, largely through the stocking of infected trout for sport fishing.

Animals↗
PubMed2005

A survey of emergency medical services in mountain areas of Europe and North America: official recommendations of the International Commission for Mountain Emergency Medicine (ICAR Medcom).

Survey of on-site treatment of patients in mountain areas of 14 countries in Europe and North America (nonresponder rate 33%) to compare emergency medical services. Around 37,535 ground rescuers and 747 helicopters are ready for evacuation of casualties and patients in mountain areas. And 1316 physicians and 50,967 paramedics take part in ground and air mountain rescue operations. In Europe, 63.2% of helicopters have a physician on board, 17.8% are staffed with a paramedic, and 19% have no medically trained personnel on board. In North America, 31.6% (p < 0.001) of helicopters are staffed with a doctor, 59.3% (p < 0.001) with a paramedic, and 9.1% (p < 0.001) have no medical personnel. The percentage of on-site treatment according to the recommendations of the International Liaison Committee on Resuscitation (ILCOR) or International Commission for Alpine Rescue (ICAR) varies among all countries (p < 0.001) and is positively related to the percentage of physician-staffed helicopters (r = 0.76, p < 0.001). Paramedics in 90.9% countries are obliged to be medically trained, but physicians only need to have a standardized training in emergency medicine in 50% (p < 0.042). On-site treatment according to ILCOR or ICAR recommendations is performed more often in countries where physicians are regularly involved in mountain rescue operations. However, no conclusions can be drawn from the data as to the efficiency of treatment. The data show a lack of medical education in specific, mountain rescue-related problems. Physicians involved should undergo suitable training.

Air Ambulances↗
PubMed2003

Mutagenic characteristics of river waters flowing through large metropolitan areas in North America.

The hanging technique using blue rayon, which specifically adsorbs mutagens with multicyclic planar structures, has the advantages over most conventional methods of not having to bring large volumes of water back to the laboratory for extraction of organic materials. Therefore, for the same effort the hanging blue rayon technique allows for the analysis of more samples from remote sites, although it has a disadvantage of not allowing quantitative analysis. In this study, the blue rayon hanging technique was used to collect organic mutagens in river waters that flow through metropolitan areas in northeastern North America. Monitoring was performed at a total of 21 sites: the Providence River system (4 sites), the Charles River (2 sites), the Potomac River (6 sites), the St. Lawrence River (5 sites), the Hudson River (3 sites), and the East River (1 site). Mutagenicity was evaluated using the Salmonella assay with strains TA98, TA100, YG1024, YG1041, and YG1042 with and without metabolic activation. The results demonstrated that strains YG1041 and YG1024 were much more sensitive than TA98 with S9 mix. Fifteen samples out of 21 were positive in YG1041 with S9 mix. Six samples gave 5000-18,400 revertants/g blue rayon equivalent. YG1042 was also much more sensitive than TA100. Eight samples were positive in YG1042 with S9 mix. The highest activity was 10,200 revertants/g blue rayon equivalent. The overall results showed that rivers flowing through major cities in North America contain frameshift-type, aromatic amine-like mutagenic activity. However, the levels of mutagenic activity in these rivers were much lower than expected based on prior analyses and calculated population-to-discharge ratios. Further research, such as detailed chemical analyses and/or simultaneous comparisons of several different adsorbents (e.g. XAD and blue rayon), will be needed to clarify the observed differences between North American blue rayon values and published values for European and Asian river systems.

Environmental Monitoring↗
PubMed2002

A 10-year review of pediatric perfusion practice in North America.

In December 1999, 145 North American pediatric open-heart institutions were mailed an updated survey as a follow-up of two earlier surveys, 1989 and 1994. The survey consisted of 81 questions pertaining to demographics, equipment, techniques and patient monitoring. This survey, following a similar format of the two earlier surveys, provides a 10-year review encompassing both new and founded practices performed during the conduct of pediatric cardiopulmonary bypass. Responses were received from 83 hospitals, for a 57% response rate. Of the respondents, 72 were active pediatric open-heart centers, 67% performing both adult and pediatric cardiac surgery and 33% performing pediatric surgery exclusively. The mean number of pediatric cases performed in 1999 was 169, compared to 101 cases in 1989 and 145 cases in 1993. Of the 72 respondents, 51% were performing greater than 100 cases/year, whereas 3% of centers were performing under 25 cases/year. As the decade progressed, bubble oxygenators were completely replaced by their membrane counterpart. The use of ultrafiltration, reported first in the 1989 survey, has risen by over 30%. The use of colloids in the prime, specifically 25% albumin, has increased in use from 34% in 1989 to 85% in 1999. Rewarming gradients are used by 100% of respondents with a mean gradient of 9.4 degrees C between the patient and water bath. Myocardial protection has seen an increase of close to 20% in the use of blood cardioplegia. The use of safety devices is also on the rise with more centers using level detectors (79%), bubble detectors (88%) and arterial line filters (96%). Centers relying on the use of cardiac assist devices have increased by 25% since 1989. Results of this survey suggest a movement toward a higher volume of cases being performed at fewer centers. While some diversity is seen, movement toward greater homogeneity, first noted in the 1994 survey, continues in 1999.

Adolescent↗
PubMed1996

An analysis of the food plants and drug plants of native North America.

This paper compares the medicinal and food floras of the native peoples of North America. There is a surprising overlap of these floras by both family and taxon. Yet there are also substantial differences-food and medicine tend to involve different plant parts, plant habit, and plant character. The similarities and differences are considered in an evolutionary context and a theoretical perspective is suggested to account for these facts.

Indians, North American↗
PubMed2006

Characterization of fluoroquinolone-resistant beta-hemolytic Streptococcus spp. isolated in North America and Europe including the first report of fluoroquinolone-resistant Streptococcus dysgalactiae subspecies equisimilis: report from the SENTRY Antimicrobial Surveillance Program (1997-2004).

Beta-hemolytic streptococci are common bacterial pathogens that can cause serious invasive disease, and although this group of species has remained susceptible to the fluoroquinolone class, resistant strains have been reported. This multicenter investigation determined the rate of fluoroquinolone-resistant beta-hemolytic streptococci using the SENTRY Antimicrobial Surveillance Program network data (1997-2004). Forty-seven surveillance culture isolates of beta-hemolytic streptococci from North America and Europe with elevated levofloxacin MIC results (2 to >32) microg/mL were tested for susceptibility to other fluoroquinolones including ciprofloxacin, garenoxacin, gatifloxacin, gemifloxacin, and moxifloxacin using reference broth microdilution and Etest (BIODISK, Solna, Sweden) methods. Strains were characterized using polymerase chain reaction and sequencing to detect mutations in the quinolone-resistance determining region (QRDR). The beta-hemolytic streptococci isolates with reduced fluoroquinolone susceptibility included the following Lancefield groups: A (Streptococcus pyogenes; 9 strains), B (Streptococcus agalactiae; 24 strains), C and G (14 strains). Vitek and API 20 strep (bioMerieux, Hazelwood, MO) identification systems, as well as conventional biochemical methods and colony morphology, were used to confirm the organism identifications. The overall potency (MIC90 in microg/mL) for the fluoroquinolones against all tested beta-hemolytic streptococci showed the following rank order: gemifloxacin (0.06) > garenoxacin (0.12) > moxifloxacin (0.25) > gatifloxacin (0.5) > levofloxacin = ciprofloxacin (1). The rate of levofloxacin-resistant beta-hemolytic streptococci in the SENTRY program was 0.14% (Europe) and 0.51% (North America) during the study period. All levofloxacin-resistant strains tested by molecular methods had significant mutations in either parC (position 79 or 83) and/or gyrA (position 81 or 85). All but 2 isolates with high-level resistance to levofloxacin (>32 microg/mL) had gyrA mutations. Strains with lower MIC values to levofloxacin (2-4 microg/mL) only had mutations in parC. The increasing rate of fluoroquinolone-resistant streptococci including Streptococcus pneumoniae, viridans group streptococci, and the more recently reported beta-hemolytic streptococci, is becoming a clinical concern due to the morbidity and mortality caused by these pathogens.

Adolescent↗
PubMed2002

Twenty-five years of clinical research for patients with limited-stage small cell lung carcinoma in North America.

BACKGROUND: To determine the changes in clinical trials and outcomes of patients with limited-stage small cell lung carcinoma (SCLC) treated on Phase III randomized trials initiated in North America between 1972 and 1992. METHODS: Phase III trials from 1972 to 1992 for patients with limited-stage SCLC were identified. Patients with limited-stage SCLC treated during a similar time interval were also evaluated in the Surveillance, Epidemiology, and End Results (SEER) database. Trends were tested in the number of trials, in the number and gender of patients entered on trial, and in survival duration over time. RESULTS: Thirty trials involving 6564 patients were eligible for analyses. Nineteen trials (61%) involving 3626 patients were initiated within the first half of this time period (1972-1981). The median of median survival times of all patients treated on the control arms of the Phase III trials initiated between 1972 and 1981 and between 1982 and 1992 were 12.0 months (range, 10-16 months) and 17.0 months (range, 11-20 months), respectively (P < 0.001). Of 26 studies available for survival analysis, 5 (19%) showed a statistically significant survival prolongation in the experimental arm compared with the control arm with a median prolongation of 3.4 months (range, 1-5.2 months). All five evaluated some aspect of thoracic radiation therapy. Over a similar time period, there was a 6.4-month increase in the median survival of limited-stage SCLC patients listed in the SEER database (P < 0.0001) and a more than doubling of the 5-year survival from 5.2% to 12.1% (P = 0.0001). CONCLUSIONS: Analyses of the patients with limited-stage SCLC treated on Phase III trials in North America initiated between 1972 and 1992 and those listed in the SEER database show significant improvements in median survivals. Furthermore, the 5-year survival of patients with limited-stage SCLC listed in the SEER database has more than doubled over the last 25 years. Further research will be needed to determine the relative contribution of improved therapy, supportive care, and stage migration to this prolongation in survival.

Adult↗
PubMed1999

Molecular epidemiological survey of penicillin-resistant Streptococcus pneumoniae from Asia, Europe, and North America.

One hundred penicillin-resistant Streptococcus pneumoniae (PRSP) strains from Asia, Europe, and North America were analyzed using pulsed-field gel electrophoresis; fingerprinting of penicillin binding protein (pbp) genes; and BOX PCR. Results show that six PFGE patterns (three patterns comprising > or = 2 serotypes) were found widespread and accounted for 64 of the 100 PRSP strains.

Anti-Bacterial Agents↗
PubMed1976

Intracranial neoplasms in children: a comparison of North America, Europe, Africa, and Asia.

Series of intracranial neoplasms in childrem from four continents (North America, Europe, Africa, and Asia) are presented and their histopathological distributions are compared. Findings include a proportion of craniopharyngiomas in Japan and Africa about double that of other areas, with a relative deficit of medulloblastomas. Pinealomas also occurred approximately three times as often in Japan and Africa as elsewhere. A incidence of ependymomas in India double that of other parts of the world was noted. Astrocytomas were the most frequently occurring neoplasms in all series except the Japanese. Possible interpretations of the differences among the series, as well as proposals for further investigation, are discussed.

Africa↗
PubMed2002

Impact of COPD in North America and Europe in 2000: subjects' perspective of Confronting COPD International Survey.

To date, no international surveys estimating the burden of chronic obstructive pulmonary disease (COPD) in the general population have been published. The Confronting COPD International Survey aimed to quantify morbidity and burden in COPD subjects in 2000. From a total of 201,921 households screened by random-digit dialling in the USA, Canada, France, Italy, Germany, The Netherlands, Spain and the UK, 3,265 subjects with a diagnosis of COPD, chronic bronchitis or emphysema, or with symptoms of chronic bronchitis, were identified. The mean age of the subjects was 63.3 yrs and 44.2% were female. Subjects with COPD in North America and Europe appear to underestimate their morbidity, as shown by the high proportion of subjects with limitations to their basic daily life activities, frequent work loss (45.3% of COPD subjects of <65 yrs reported work loss in the past year) and frequent use of health services (13.8% of subjects required emergency care in the last year), and may be undertreated. There was a significant disparity between subjects' perception of disease severity and the degree of severity indicated by an objective breathlessness scale. Of those with the most severe breathlessness (too breathless to leave the house), 35.8% described their condition as mild or moderate, as did 60.3% of those with the next most severe degree of breathlessness (breathless after walking a few minutes on level ground). This international survey confirmed the great burden to society and high individual morbidity associated with chronic obstructive pulmonary disease in subjects in North America and Europe.

Age Distribution↗
PubMed2005

Prevalence and correlates of hepatitis C infection among users of North America's first medically supervised safer injection facility.

BACKGROUND: North America's first medically supervised safer injection facility (SIF) for illicit drug users was opened in Vancouver, Canada on 22 September 2003. We examined the prevalence and correlates of hepatitis C (HCV) infection among a representative cohort of SIF users. METHODS: Users of the Vancouver SIF were selected at random and asked to enrol in the Scientific Evaluation of Supervised Injecting (SEOSI) cohort. At baseline, venous blood samples were collected and an interviewer-administered questionnaire was performed. Participants who were HCV-positive were compared with HCV-negative subjects using bivariate and logistic regression analyses. RESULTS: Between 1 December 2003 and 30 July 2004, 691 participants were enrolled into the SEOSI cohort, among whom 605 (87.6%) were HCV-positive at baseline. Factors independently associated with HCV infection in logistic regression analyses included: involvement with the sex trade [adjusted odds ratio (AOR) 3.7, 95% confidence interval (CI) 2.1-6.1], history of borrowing syringes (AOR 1.8, 95%CI 1.1-2.9), and history of incarceration (AOR 2.6, 95%CI 1.5-4.4). Daily heroin use was protective against HCV infection (AOR 0.6, 95%CI 0.3-0.9). CONCLUSION: The SIF has attracted injection drug users with a high burden of HCV infection and a substantial proportion of uninfected individuals. Although cross-sectional, this study provides some insight into historical risks for HCV infection among this population, and prospective follow-up of this cohort will be useful to determine if use of the SIF is associated with reduced risk behaviour and HCV incidence.

Canada↗
PubMed1998

Field efficacy of doramectin pour-on against naturally-acquired, gastrointestinal nematodes of cattle in North America.

Seven studies were conducted under field conditions in North America to evaluate the therapeutic efficacy of doramectin in a pour-on formulation at a dosage of 500 microg/kg (1 ml/10 kg) for cattle harboring naturally-acquired infections of gastrointestinal nematodes, including species of Haemonchus, Ostertagia, Trichostrongylus, Bunostomum, Cooperia, and Oesophagostomum. In each study, 40 to 100 cattle were randomly allocated to a saline- or doramectin-treated group in a tiered manner based on Day -7 bodyweight. On Day 0, the cattle received either saline or doramectin topically, according to their treatment group. Weather and safety observations were made following treatment. No adverse reaction to treatment was observed at any time during these studies. Fecal egg count (FEC) determinations were carried out on each animal on Days -7, 0, 7, 14, and 21. Reductions in FEC for the doramectin-treated animals compared to saline-treated cattle were > or = 96.0% by Day -7 and > or = 99.0% on Days 14 and 21 for each study. Across all studies regardless of weather conditions, the reduction by Day 21 for the doramectin-treated animals compared to saline controls was 99.7% (p < or = 0.0001) and compared to pretreatment levels in doramectin-treated cattle was 99.9% (p < or = 0.0001). Doramectin pour-on should provide a useful new treatment for controlling nematode parasites of cattle.

Animals↗
PubMed1987

Aedes albopictus in North America: probable introduction in used tires from northern Asia.

North American strains of Aedes albopictus, an Asian mosquito recently introduced into the Western Hemisphere, exhibit photoperiodic sensitivity and cold-hardiness characteristics similar to strains originating from temperate zone Asia. Trade statistics for used tire imports, the most likely mode of introduction, also indicate a north Asian origin. Aedes albopictus, an important vector of dengue and a potential vector of many other arboviral diseases, may therefore have the capability of infesting much of temperate North America.

Aedes↗
PubMed1985

Viral diseases of fish: first report of carp pox in golden ide (Leuciscus idus) in North America.

Carp pox, a putative viral disease exotic to North America, occurred in golden ide 1 yr after the fish were imported into the United States from the Federal Republic of Germany. The raised, white, plaque-like lesions, which occurred on about 5% of the fish, healed spontaneously and caused no mortality. Electron micrographs showed herpesvirus-like particles associated with lesion specimens; however, no infectious viruses were detected in tests with seven warmwater fish cell lines.

Animals↗
PubMed1998

Paleoindian large mammal hunters on the plains of North America.

From approximately 11,200 to 8,000 years ago, the Great Plains of North America were populated by small Paleoindian hunting groups with well developed weaponry and the expertise to successfully hunt large mammals, especially mammoths and bison. Mammoths became extinct on the Plains by 11,000 years ago, and, although paleoecological conditions were worsening, their demise may have been hastened by human predation. After this, the main target of the Plains Paleoindian hunters consisted of subspecies of bison, Bison antiquus and Bison occidentalis. As bison populations gradually diminished, apparently because of worsening ecological conditions, by approximately 8,000 years ago, human subsistence was forced into a greater dependence on small animal and plant foods. Human paleoecology studies of the Paleoindian time period rely heavily on multidisciplinary efforts. Geomorphologists, botanists, soil scientists, palynologists, biologists, and other specialists aid archaeologists in data recovery and analysis, although, with few exceptions, their contributions are derived from the fringes rather than the mainstream of their disciplines.

Animals↗
PubMed1996

Germline mutations in the Von Hippel-Lindau disease (VHL) gene in families from North America, Europe, and Japan.

Germline mutation analysis was performed in 469 VHL families from North America, Europe, and Japan. Germline mutations were identified in 300/469 (63%) of the families tested; 137 distinct intragenic germline mutations were detected. Most of the germline VHL mutations (124/137) occurred in 1-2 families; a few occured in four or more families. The common germline VHL mutations were: delPhe76, Asn78Ser, Arg161Stop, Arg167Gln, Arg167Trp, and Leu178Pro. In this large series, it was possible to compare the effects of identical germline mutations in different populations. Germline VHL mutations produced similar cancer phenotypes in Caucasian and Japanese VHL families. Germline VHL mutations were identified that produced three distinct cancer phenotypes: (1) renal carcinoma without pheochromocytoma, (2) renal carcinoma with pheochromocytoma, and (3) pheochromocytoma alone. The catalog of VHL germline mutations with phenotype information should be useful for diagnostic and prognostic studies of VHL and for studies of genotype-phenotype correlations in VHL.

Adrenal Gland Neoplasms↗