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PubMed2001

Patterns of evolution in Discula fungi and the origin of dogwood anthracnose in North America, studied using arbitrarily amplified and ribosomal DNA.

The anthracnose epidemic caused by exotic filamentous fungi of the genus Discula threatens the future of the prized flowering (Cornus florida L.) and Pacific (C. nuttalli Aud.) dogwoods in North America. A cross-section of fungi that cause anthracnose in broadleaf temperate trees was characterized using DNA amplification fingerprinting, sequence and secondary structure analysis of the internal transcribed spacers (ITS) of nuclear ribosomal DNA (rDNA), and compatibility of hyphal anastomosis. ITS-inferred phylogenies rejected the null hypothesis of only one fungal lineage, by defining four monophyletic and well differentiated groups, corresponding to Discula sp., D. quercina, D. umbrinella and D. destructiva, with the last two species sharing a common and recent ancestor. In turn, they showed that the dogwood pathogen, D. destructiva, did not evolve directly from an indigenous population related to Discula sp. In this study, rDNA spacers that are generally considered important for protein synthesis but are selectively neutral, appeared functionally constrained and subject to selective sequence diversification. Results confirmed the high variability of D. umbrinella and the remarkable homogeneity and exotic nature of D. destructiva at the genetic level, clarified the taxonomy and phylogeny of Discula, and provided clues as to the origin and diversification of dogwood anthracnose-causing fungi.

Base Sequence↗
PubMed1998

An analysis of approaches to the management of endometrial cancer in North America: a CTF study.

OBJECTIVE: The aim of this study was to define the clinical-therapeutical approach to endometrial cancer now being followed in some of the most important centers of reference for gynecological cancer in North America by means of a questionnaire. STUDY DESIGN: The questionnaire focused on four principal areas: (1) surgical staging and therapy; (2) adjuvant treatment; (3) treatment modifications; and (4) management of advanced stages (FIGO III-IV). RESULTS: There were 48 evaluable responses (77%) received by the end of December 1994 which were considered for this analysis. Lymphadenectomy is utilized routinely in 26/48 centers (54.2%) and in selective clinical-pathological conditions in another 21/48 centers (43.5%). In the majority of centers (31/48; 64.6%) radical surgery is utilized for selected indications such as cervical involvement. Only 3/48 (6.2%) centers consider the vaginal approach totally inappropriate. The great majority (40/48; 83.3%) of the centers considered postsurgical adjuvant therapy to be necessary in FIGO Stage Ic. Brachytherapy is routinely performed in 3 centers (6.2%) in postsurgical management of Stage I endometrial cancer, while the majority of the centers (31/48; 64.6%) perform brachytherapy of the vaginal vault in certain clinical-pathological conditions. A wide variety of treatments are used for advanced stages (FIGO III-IV). CONCLUSIONS: It emerges that some controversial aspects exist on endometrial cancer treatment, and these conflicting data need a large-scale multicenter randomized clinical trial.

Adult↗
PubMed1998

Porphyria cutanea tarda, hepatitis C, and HFE gene mutations in North America.

In some, but not all countries, porphyria cutanea tarda (PCT) has been associated with chronic infection with the hepatitis C virus (HCV). Recently, PCT has also been associated with mutations in the HFE gene that are associated with HLA-linked hereditary hemochromatosis. Until now, few studies of these associations have been reported from North America. The aims of this study were: 1) to assess the prevalence of HCV infection and HFE mutations in North American patients with PCT; 2) to compare demographic and laboratory features between those who are HCV-positive and HCV-negative; and 3) to study urinary porphyrin excretions in American HCV-positive patients without clinically manifest PCT. Clinical and laboratory data, including tests for HCV and urinary porphyrins, were collected from 70 unselected patients with typical PCT. Urinary porphyrins were also measured in 110 non-PCT patients with chronic hepatitis C. Mutational analyses of the HFE gene were performed in 26 PCT patients. Thirty-nine of 70 (56%) of the PCT patients had evidence of HCV infection. Thirty-two of 39 PCT patients with HCV were men, all of whom used alcohol. In contrast, 22 of 31 PCT patients without HCV infection were women, 12 of whom had taken estrogens. The HCV-positive group was more likely to have used illicit intravenous drugs (45% vs. 0%; P = 0.01), to have had several (>4) sex partners (48% vs. 13%; P = 0.005), and less likely to have no known risk factors for HCV infection (33% vs. 78%; P = 0.004). Total urinary porphyrin excretion was the same in the two groups, but those with HCV infection had a significantly lower percentage of uroporphyrin and higher percentages of hepta-and hexa-carboxy porphyrins in urine. Sixteen of 110 (15%) HCV-positive subjects without PCT had increased urinary porphyrins, but, unlike PCT, these were mainly coproporphyrin. Forty-two percent of PCT patients carried the C282Y mutation of HFE (15% homozygous), and another 31% carried the H63D mutation (8% homozygous). Thus, 73% of PCT patients had one of these mutations. The prevalence of HCV infection (56%) and mutations in the HFE gene (73%) are high among North American patients with PCT. Alcohol and estrogen use are important additional risk factors. All PCT patients should be tested for HCV infection and for HFE gene mutations. Although HCV infection is a trigger for PCT, preclinical PCT is rare in chronic HCV hepatitis C in the United States.

Adult↗
PubMed2002

Publication rates of presentations made at annual meetings of the American Orthopaedic Society for Sports Medicine and the Arthroscopy Association of North America.

The purpose of this study was to determine the publication rates of presentations made at the annual meetings of 2 sports medicine specialty societies--the American Orthopaedic Society for Sports Medicine (AOSSM) and the Arthroscopy Association of North America (AANA). We created a database covering annual AOSSM meetings from 1990 to 1993 (4 years) and annual AANA meetings from 1991 to 1993 (3 years) and searched the Melvyl Medline Plus database for abstracts from 1990 through 1998 to determine which had been published in peer-reviewed journals. Of the 333 abstracts listed for the 1990 to 1993 meetings, 198 (59.5%) were published in peer-reviewed journals. Publication rates of the AOSSM and AANA meetings were 68.1% and 50.9%, respectively. The majority of articles were published in American Journal of Sports Medicine (40.1%) and Arthroscopy (30.3%). Publication rates of presentations made at meetings of these sports medicine specialty societies are high and exceed the publication rates associated with meetings of other medicine specialty societies.

Arthroscopy↗
PubMed2004

Multivariate discrimination among cryptic species of the mite genus Chaetodactylus (Acari: Chaetodactylidae) associated with bees of the genus Lithurgus (Hymenoptera: Megachilidae) in North America.

Twenty-seven morphological characters from 111 heteromorphic deutonymphs of the mite genus Chaetodactylus Rondani (Acari: Chaetodactylidae) were analyzed. The mites were collected from four species of bees of the genus Lithurgus Berthold (Hymenoptera: Megachilidae) in continental North America. Principal component and canonical variates analyses on Darroch and Mosimann shape and size-and-shape variables revealed the presence of three cryptic species. Chaetodactylus gibbosi sp. n. (Florida) is geographically isolated from C. lithurgi sp. n. distributed in Texas, New Mexico, Arizona, Colorado, and Idaho. Sympatric C. lithurgi and C. abditus sp. n. (USA: Arizona, Mexico: Socorro Is.) are seasonally isolated in Arizona. Chaetodactylus gibbosi is associated with a single bee species, Lithurgus gibbosus Smith in Florida. The host range of C. lithurgi includes bees flying predominantly in the spring: L. apicalis Cresson, L. littoralis Cockerell, and western L. gibbosus. Chaetodactylus abditus sp. n. is associated with L. planifrons Friese and L. echinocacti Cockerell, flying predominantly in the fall in Arizona. No distinct groups separated by geographic locality or size were detected in any species. A six-variable model developed by the canonical variates analysis and estimated using jackknife resampling and external validation (n = 100) is capable of classifying the three species with 100% accuracy. Factors that influenced speciation of cryptic species of Chaetodactylus associated with Lithurgus are discussed. Based on morphological and geographical data and data on mite associates, the western and eastern populations of the bee L. gibbosus are distinct. Therefore, the taxonomic status of L. gibbosus s. lat. should be reevaluated.

Animals↗
PubMed2004

Huntington's Disease-like 2 (HDL2) in North America and Japan.

Huntington's Disease-like 2 (HDL2) is a progressive, autosomal dominant, neurodegenerative disorder with marked clinical and pathological similarities to Huntington's disease (HD). The causal mutation is a CTG/CAG expansion mutation on chromosome 16q24.3, in a variably spliced exon of junctophilin-3. The frequency of HDL2 was determined in nine independent series of patients referred for HD testing or selected for the presence of an HD-like phenotype in North America or Japan. The repeat length, ancestry, and age of onset of all North American HDL2 cases were determined. The results show that HDL2 is very rare, with a frequency of 0 to 15% among patients in the nine case series with an HD-like presentation who do not have the HD mutation. HDL2 is predominantly, and perhaps exclusively, found in individuals of African ancestry. Repeat expansions ranged from 44 to 57 triplets, with length instability in maternal transmission detected in a repeat of r2=0.29, p=0.0098). The results further support the evidence that the repeat expansion at the chromosome 16q24.3 locus is the direct cause of HDL2 and provide preliminary guidelines for the genetic testing of patients with an HD-like phenotype.

Adult↗
PubMedDate not supplied

The Pediatric Orthopaedic Society of North America pediatric orthopaedic functional health questionnaire: an analysis of normals.

Several questionnaires have been developed in an attempt to measure real-life functional levels of pediatric orthopaedic patients. One in particular was developed by the Pediatric Orthopaedic Society of North America (POSNA) in 1994. This POSNA instrument yields four functional assessment scores, a global function score, and a happiness score (each having a possible range from 0 to 100). In this study, the POSNA questionnaire was administered to the parents of 57 normal children and 27 normal adolescents to determine how normal respondents can be expected to score. Means, standard deviations, and other statistics were derived for the functional scores. It was concluded that normal children should respond quite high on all the scores, possibly 100. These results allow us to understand that a child scoring in the low 80s or less is functioning at a different level than the normal child.

Adolescent↗
PubMed2000

Epidemiology of lower extremity amputation in centres in Europe, North America and East Asia

BACKGROUND: This study was established to enable a comparison of lower extremity amputation incidence rates between different centres around the world. METHODS: Ten centres, all with populations greater than 200 000, in Japan, Taiwan, Spain, Italy, North America and England collected data on all amputations done between July 1995 and June 1997. Patients were identified from at least two data sources (to allow checks on ascertainment); denominator populations were based on census figures. RESULTS: The highest amputation rates were in the Navajo population (43.9 per 100 000 population per year for first major amputation in men) and the lowest in Madrid, Spain (2.8 per 100 000 per year). The incidence of amputation rose steeply with age; most amputations occurred in patients over 60 years. In most centres the incidence was higher in men than women and the incidence of major amputations was greater than that of minor amputations. Diabetes was associated with between 25 and 90 per cent of amputations. CONCLUSION: Apart from the Navajo centre, differences in the known prevalence of diabetes could not account for the differences in overall incidence of amputation. Differences in the prevalence of peripheral vascular disease are likely to be important, but this and the role of other factors, including availability of health care, are worthy of further investigation.

Adolescent↗
PubMed2000

Genetic characterization of H3N2 influenza viruses isolated from pigs in North America, 1977-1999: evidence for wholly human and reassortant virus genotypes.

Since 1998, H3N2 viruses have caused epizootics of respiratory disease in pigs throughout the major swine production regions of the U.S. These outbreaks are remarkable because swine influenza in North America had previously been caused almost exclusively by H1N1 viruses. We sequenced the full-length protein coding regions of all eight RNA segments from four H3N2 viruses that we isolated from pigs in the Midwestern U.S. between March 1998 and March 1999, as well as from H3N2 viruses recovered from a piglet in Canada in January 1997 and from a pig in Colorado in 1977. Phylogenetic analyses demonstrated that the 1977 Colorado and 1997 Ontario isolates are wholly human influenza viruses. However, the viruses isolated since 1998 from pigs in the Midwestern U.S. are reassortant viruses containing hemagglutinin, neuraminidase and PB1 polymerase genes from human influenza viruses, matrix, non-structural and nucleoprotein genes from classical swine viruses, and PA and PB2 polymerase genes from avian viruses. The HA proteins of the Midwestern reassortant swine viruses can be differentiated from those of the 1995 lineage of human H3 viruses by 12 amino acid mutations in HA1. In contrast, the Sw/ONT/97 virus, which did not spread from pig-to-pig, lacks 11 of these changes.

Animals↗
PubMed2001

Ozone air quality over North America: part I--a review of reported trends.

Ozone and precursor trends can be used to measure the effectiveness of regulatory programs that have been implemented. In this paper, we review trends in the concentrations of O3 NOx, and HCs over North America that have been reported in the literature. Although most existing trend studies are confounded by meteorological variability, both the raw data trends and the trends adjusted for meteorology collectively indicate a general decreasing trend in O3 concentrations in most areas of the United States during 1985-1996. In Canada, mean daily maximum 1-hr O3 concentrations at urban sites show mixed trends with a majority of sites showing an increase from 1980 to 1993. Mean daily maximum 1-hr O3 at most regionally representative Canadian sites appears to decrease from 1985 to 1993 or shows no significant change. There are far fewer data and analyses of NOx and HC trends. Available studies covering various ranges of years indicate decreases in ambient NO and HC concentrations in Los Angeles, CA, decreases in HC concentrations in northeastern U.S. cities, and decreases in NOx concentrations in Canadian cities. Two key needs are long-term HC and NOx measurements, particularly at rural sites, and a systematic comparison of trend detection techniques on a reference data set.

Air Pollution↗
PubMed1992

Progress in blood lipid reporting practices by clinical laboratories in North America. Changes from 1985 to 1990.

In an attempt to assess the impact of the National Cholesterol Education Program recommendations and to provide follow-up to a 1985 survey of blood lipid reporting practices in 152 academic clinical laboratories in North America, the same laboratories were resurveyed regarding current blood lipid-reporting practices. All 97 laboratories that responded to our survey routinely measured serum total cholesterol, while 94% measured high-density lipoprotein cholesterol, 99% measured triglycerides, 26% apolipoproteins A1 and B, and a single laboratory measured apolipoprotein E. There was a marked downward shift in reference ranges for serum total cholesterol used by laboratories in 1990 compared with 1985. Of the laboratories responding to both surveys, 90% lowered their reported reference values. Changes in the sources of reference ranges were also noted. The percent of laboratories using reference ranges based on age and sex fell from 52% to 21% and from 31% to 10%, respectively. The number of laboratories designating patient risk for coronary heart disease rose from 31% to 72%. Currently, 61% of laboratories designating risk use the National Cholesterol Education Program guidelines for serum total cholesterol. The use of other risk designations, including high-density lipoprotein--cholesterol, total cholesterol to high-density lipoprotein cholesterol ratio, low-density lipoprotein cholesterol, and apolipoproteins changed only modestly during the 5-year interval. The current reporting patterns reflect simplified and more uniform practices apparently in response to the National Cholesterol Education Program.

Adult↗
PubMed2004

Biological control of cereal aphids in north america and mediating effects of host plant and habitat manipulations.

The predator and parasitoid fauna associated with cereal aphids is described, emphasizing the fauna associated with classical biological control efforts against the greenbug and Russian wheat aphid. We focus on literature from North America and include work from Europe and elsewhere when it is desirable to draw contrasts between approaches that affect cereal aphid biological control. Effects on natural enemies of cereal aphids are described that appear associated with plant traits that are innate, bred, or induced by aphid feeding. Examples of habitat manipulations, within and bordering cereal fields and within the broader landscape in which cereal production resides, affecting predators and parasitoids of cereal aphids are presented. These mediating effects of host plant and habitat manipulations on cereal aphid biological control provide significant and underexplored avenues to optimize cereal aphid management.

Animals↗
PubMed2003

Snowmobile injuries in North America.

The snowmobile was developed to move people and supplies, and for emergencies in regions where heavy snow prohibited the use of conventional vehicles. Today, snowmobiling has become a popular winter sport enjoyed by more than 2 million people of all ages in North America. However, the modern snowmobile can weigh in excess of 600 pounds and travel at speeds exceeding 90 miles per hour. Each year snowmobile accidents produce approximately 200 deaths and 14,000 injuries. Excess speed, alcohol, driver inexperience, and poor judgment are the leading causes of accidents. Injuries incurred in children and adults often are extremity fractures, but can involve any organ system. Similar to motor vehicle accidents, multisystem trauma occurs frequently with head injury the leading cause of death. Reduction in injury and death rates is urgently needed and can be accomplished through education and legislation.

Adolescent↗
PubMed1989

The teaching of clinical pharmacology in Europe and North America.

A recent survey conducted under the auspices of the WHO shows that on average in European medical schools only 28 hours of teaching are devoted to clinical pharmacology, whereas over 100 hours are devoted to pharmacology. In many schools no clinical pharmacology is taught, and there is a lack of trained individuals and posts in clinical pharmacology. In North America there is a similar lack of clinical pharmacology teaching.

Europe↗
PubMed2005

Phylogenetic analyses of type A influenza genes in natural reservoir species in North America reveals genetic variation.

The matrix (M) (98 isolates), nucleoprotein (NP) (67 isolates), non-structural (NS) (107 isolates), H4 subtype HA1 (21 isolates) and H6 (38 isolates) subtype HA1 region of the hemagglutinin (HA) gene were sequenced from avian influenza viruses isolated from North American wild aquatic birds between 1969 and 2003. Sequences were compared phylogenetically with all available wild aquatic bird isolate sequences and sequences from isolates from gallinaceous poultry and mammalian host species. Among the wild aquatic bird isolates the NS subtype B NS1 and subtype B NS2 proteins were the most conserved with minimum amino acid identities of 98.0 and 99.0%, respectively. The H6 HA1, M and NS subtype A genes were more divergent; both nucleotide and amino acid divergence levels were similar to those of the same genes from gallinaceous poultry and mammalian origin type A influenza isolates. Phylogenetically none of the genes assorted geographically (within North America), chronologically or by species of origin, unlike isolates from non-natural host species, suggesting that selection pressure is low. A lack of clear temporal or spatial grouping shows that multiple lineages of virus co-circulate and precludes the development of an epidemiological map for influenza virus from these species.

Animals↗
PubMed1987

Infections associated with milk and dairy products in Europe and North America, 1980-85.

Outbreaks of infection associated with milk and other dairy products in Europe and North America from 1980 to 1985 are reviewed. Salmonella spp. and Campylobacter spp. were the most commonly identified etiological agents, while other infections of animal origin, in particular listeriosis and yersiniosis, were increasingly reported. Most infections were attributed to untreated cows' milk or cheese, but also increasingly to contaminated "heat-treated" products. Heat-treatment is highly effective in controlling foodborne disease, but may be insufficient if not complemented by high standards of hygiene throughout production and processing. Large community outbreaks of salmonellosis, listeriosis, and yersiniosis in Canada, Sweden, the United Kingdom, and the USA that were associated with contaminated "heat-treated" liquid milk, powdered milk, or cheese emphasize the vulnerability of dairy produce.

Animals↗
PubMed1976

Cystobranchus meyeri sp. n. (Hirudinea: Piscicolidae) from Catostomus commersoni Lacépède in North America.

Cystobranchus meyeri sp. n. (Hirudinea: Piscicolidae) is described from the white sucker, Catostomus commersoni Lacépède (Osteichthyes: Catostomidae) from the Mohawk River drainage of eastern New York. Size, details of internal anatomy, and the presence of 8 ocelli on the posterior sucker distinguish it from the 3 other species in North America. A table compares the members of this genus and a key to the species is included. Problems of classification, host records, and host specificity are discussed.

Animals↗
PubMed2004

Complete DNA sequence analyses of the first two varicella-zoster virus glycoprotein E (D150N) mutant viruses found in North America: evolution of genotypes with an accelerated cell spread phenotype.

Varicella-zoster virus (VZV) is considered to be one of the most genetically stable of all the herpesviruses. Yet two VZV strains with a D150N missense mutation within the gE glycoprotein were isolated in North America in 1998 and 2002. The mutant strains have an accelerated cell spread phenotype, which distinguishes them from all wild-type and laboratory viruses. Since the VZV genome contains 70 additional open reading frames (ORFs), the possibility existed that the phenotypic change was actually due to an as-yet-undiscovered mutation or deletion elsewhere in the genome. To exclude this hypothesis, the entire genomes of the two mutant viruses were sequenced and found to contain 124,883 (VZV-MSP) and 125,459 (VZV-BC) nucleotides. Coding single-nucleotide polymorphisms (SNPs) were identified in 14 ORFs. One missense mutation was discovered in gH, but none was found in gB, gI, gL, or gK. There were no coding SNPs in the major regulatory protein ORF 62. One polymorphism was discovered which could never have been anticipated based on current knowledge of herpesvirus genomics, namely, the origins of replication differed from those in the prototype strain but not in a manner expected to affect cell spread. When the two complete mutant VZV sequences were surveyed in their entirety, the most reasonable conclusion was that the increased cell spread phenotype was dependent substantially or solely on the single D150N polymorphism in glycoprotein gE. The genomic results also expanded the evolutionary database by identifying which VZV ORFs were more likely to mutate over time.

Aged↗