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Molecular and serologic evidence of Anaplasma phagocytophilum infection in cats in North America.

Anaplasma phagocytophilum DNA was detected in blood of clinically ill cats from Massachusetts (n = 4) and Connecticut (1) by use of polymerase chain reaction assay and DNA sequencing. All 5 cats were allowed outdoors, and Ixodes scapularis were found on 3 cats. Clinical signs of fever, anorexia, and lethargy resolved quickly after treatment with doxycycline or tetracycline. Serum samples from each cat reacted with A. phagocytophilum morulae via an indirect fluorescent antibody assay; positive antibody titers persisted even after 21 to 30 days of treatment with tetracycline. To the authors' knowledge, this is the first report of A. phagocytophilum infection of domestic cats in North America. Results suggest that infection with the organism may be associated with clinical illness in some cats.

Anaplasma phagocytophilum↗

Classification, epidemiology and implications of chronic prostatitis in North America, Europe and Asia.

The last decade has seen a resurgence of interest and exciting new research on chronic prostatitis and related syndromes. One important reason for this enthusiasm is the recognition that chronic prostatitis syndromes represent an important worldwide health care problem. New data suggesting that chronic prostatitis syndromes may have important long-term consequences are a second reason for the resurgence of research interest. This article reviews the new classification of chronic prostatitis syndromes. Emphasis is then given to summarizing new data on the epidemiology of chronic prostatitis. We concentrated on population-based studies employing reasonable case-definitions to survey various populations from North America, Europe and Asia. These studies suggest that prostatitis syndromes are common, with 2-10% of adult men suffering from symptoms compatible with chronic prostatitis at any time. Approximately 15% of men suffer from symptoms of prostatitis at some point in their lives. Preliminary epidemiological and biological studies also suggest that chronic prostatitis may be associated with an increased risk for development of benign prostatic hyperplasia and prostate cancer. These findings support the conclusions that chronic prostatitis is an important international health care problem that merits increased priority from clinicians as well as increased clinical and basic science research.

Acute Disease↗

A sharp lithosphere-asthenosphere boundary imaged beneath eastern North America.

Plate tectonic theory hinges on the concept of a relatively rigid lithosphere moving over a weaker asthenosphere, yet the nature of the lithosphere-asthenosphere boundary remains poorly understood. The gradient in seismic velocity that occurs at this boundary is central to constraining the physical and chemical properties that create differences in mechanical strength between the two layers. For example, if the lithosphere is simply a thermal boundary layer that is more rigid owing to colder temperatures, mantle flow models indicate that the velocity gradient at its base would occur over tens of kilometres. In contrast, if the asthenosphere is weak owing to volatile enrichment or the presence of partial melt, the lithosphere-asthenosphere boundary could occur over a much smaller depth range. Here we use converted seismic phases in eastern North America to image a very sharp seismic velocity gradient at the base of the lithosphere-a 3-11 per cent drop in shear-wave velocity over a depth range of 11 km or less at 90-110 km depth. Such a strong, sharp boundary cannot be reconciled with a purely thermal gradient, but could be explained by an asthenosphere that contains a few per cent partial melt or that is enriched in volatiles relative to the lithosphere.

Journal Article↗

Correspondence of soldier defense secretion mixtures with cuticular hydrocarbon phenotypes for chemotaxonomy of the termite genus Reticulitermes in North America.

Soldier defense secretions from samples of Reticulitermes collected in California, Nevada, Arizona, New Mexico, and Georgia were characterized and correlated with cuticular hydrocarbon phenotypes. Twenty-seven cuticular hydrocarbon phenotypes have been defined, and soldier defense secretion (SDS) phenotypes have been described for 25 of these. Forty-five terpenoid compounds were found, including monoterpenes, sesquiterpenes, and a few diterpenes. The monoterpenes include (-)-alpha-pinene, (-)-beta-pinene, (-)-camphene, myrcene, (Z)- and (E)-ocimene, and (-)-limonene. The major sesquiterpenes produced are (+)-gamma-cadinene, (+)-gamma-cadinene aldehyde, (-)-germacrene A, germacrene B, gamma-himachalene, and beta-bisabolene. Some SDS phenotypes pair with more than one cuticular hydrocarbon phenotype; however, with two exceptions, each hydrocarbon phenotype is associated with only one SDS phenotype. These chemical characterizations lend support to the conclusion that there are numerous undescribed species of Reticulitermes in North America.

Adaptation, Physiological↗

Multivariate morphometric discrimination of nymphal and adult forms of the blacklegged tick (Acari: Ixodidae), a principal vector of the agent of Lyme disease in eastern North America.

A morphological study of postlarval stages of the blacklegged tick, Ixodes scapularis Say, was conducted to examine congruence between northern (formerly I. dammini Spielman, Clifford, Piesman & Corwin) and southern morphotypes. The character set totaled 17 for females, 25 for males, and 28 for nymphs. Populations from 6 geographic areas, F1 progeny from reciprocal crosses between I. scapularis from Massachusetts and Georgia, and I. pacificus Cooley & Kohls from California were measured. Characters, except cornua length in nymphs, were positively correlated with PC1, indicating it was a general-size eigenvector. Characters used previously by others to distinguish northern and southern forms had a highly positive allometric relationship to general size. In canonical variate analysis (CVA) of nymphs, canonical score 1 (CAN1) discriminated I. pacificus from all other groups, canonical score 2 (CAN2) discriminated the remaining groups in a pattern that correlated with latitude, and canonical score 3 (CAN3) separated the western (Minnesota and Missouri) from the eastern groups. Size-free CVA indicated that north-south discrimination was size dependent, but that variation between Missouri and all other groups was not size related. Mahalanobis distances between groups within stages were significant with the exception of the 2 groups of female progeny of reciprocal crosses (Massachusetts x Georgia). Analysis of variance and Student-Newman-Keuls tests revealed that each geographic population differed from all other groups in at least 1 nymphal character. Nymphs from northern areas (Minnesota, Massachusetts, Maryland) differed from those from southern areas (Missouri, North Carolina, Georgia) in characters associated with the basis capitulum (longer intercornua and interauricular distances, basis capituli, and hypostome internal files, larger auriculae, but shorter cornua). Western populations (Minnesota, Missouri) differed from eastern populations in idiosomal characters (broader scutum, larger coxae III and IV). Frequency polygons of characters with the greatest differences indicated that data are continuous and geographic variation is overlapping. Thus, the data support the previous contention of conspecificity of I. scapularis and I. dammini. I. scapularis appears to be a polytypic species with a widespread geographic distribution exhibiting north-south and east-west morphological clines in eastern North America.

Animals↗

Survey of forceps delivery in North America in 1990.

OBJECTIVE: To determine whether opinions and practice patterns have markedly changed over the past decade and whether clinicians are cognizant of the new ACOG definitions for forceps deliveries. METHODS: Two hundred ninety-five United States and Canadian residency programs were surveyed via a questionnaire; 203 (69%) responded. Statistical analysis was performed using the chi 2 test, Yates correction factor, and the extended Mantel-Haenszel test. RESULTS: All but two program directors (99%) were familiar with the new definitions, which were being used by 162 (80%) of the programs. All institutions used outlet and low forceps, although 14% no longer performed midforceps deliveries. Attending faculty were the primary instructors in 67% of United States and 100% of Canadian programs. Simpson forceps were the most commonly used for outlet (46%) and low (43%) forceps deliveries. Kielland (27%) and Simpson (24%) instruments were most commonly used for midforceps deliveries. CONCLUSION: Although the rate of midforceps use decreased, operative vaginal delivery was still commonly taught in residency programs in North America in 1990.

Canada↗

Toxin production by an emerging strain of Clostridium difficile associated with outbreaks of severe disease in North America and Europe.

BACKGROUND: Toxins A and B are the primary virulence factors of Clostridium difficile. Since 2002, an epidemic of C difficile-associated disease with increased morbidity and mortality has been present in Quebec province, Canada. We characterised the dominant strain of this epidemic to determine whether it produces higher amounts of toxins A and B than those produced by non-epidemic strains. METHODS: We obtained isolates from 124 patients from Centre Hospitalier Universitaire de Sherbrooke in Quebec. Additional isolates from the USA, Canada, and the UK were included to increase the genetic diversity of the toxinotypes tested. Isolate characterisation included toxinotyping, pulsed-field gel electrophoresis (PFGE), PCR ribotyping, detection of a binary toxin gene, and detection of deletions in a putative negative regulator for toxins A and B (tcdC). By use of an enzyme-linked immunoassay, we measured the in-vitro production of toxins A and B by epidemic strain and non-dominant strain isolates. FINDINGS: The epidemic strain was characterised as toxinotype III, North American PFGE type 1, and PCR-ribotype 027 (NAP1/027). This strain carried the binary toxin gene cdtB and an 18-bp deletion in tcdC. We isolated this strain from 72 patients with C difficile-associated disease (58 [67%] of 86 with health-care-associated disease; 14 [37%] of 38 with community-acquired disease). Peak median (IQR) toxin A and toxin B concentrations produced in vitro by NAP1/027 were 16 and 23 times higher, respectively, than those measured in isolates representing 12 different PFGE types, known as toxinotype 0 (toxin A, median 848 microg/L [IQR 504-1022] vs 54 microg/L [23-203]; toxin B, 180 microg/L [137-210] vs 8 microg/L [5-25]; p<0.0001 for both toxins). INTERPRETATION: The severity of C difficile-associated disease caused by NAP1/027 could result from hyperproduction of toxins A and B. Dissemination of this strain in North America and Europe could lead to important changes in the epidemiology of C difficile-associated disease.

Bacterial Proteins↗

Computerized scientific exhibit utilization: observations from infoRAD at the radiologic society of North America Scientific Assembly.

No publication has discussed utilization of computer scientific exhibits (CSE) at national symposia, despite their growing numbers. The hypothesis of this project was that, when given a choice, viewers initially would prefer a more conventional paper presentation of a scientific exhibit over that of an electronic presentation. A nearly identical paper version of the introductory screen to an infoRAD CSE was placed adjacent to the workstation. Utilization of the paper introduction, computer introduction, and both, as well as subsequent behavior, was recorded. Of 67 visitors, initial user choice was 56.7% paper and 43.3% computer. Over the entire time at the exhibit 25.4% only looked at the handout, 25.4% only at the computer, and 49.3% perused both. Only 10.5% completed the entire exhibit, and 0.94% of total registrants visited the CSE. Overall, 74.7% perused the CSE when leaving the exhibit area. Upon arrival, viewers preferred the more conventional paper presentation, confirming the project hypothesis. Surprisingly, about 75% eventually perused at least a portion of the computer presentation. Although a small fraction of Radiologic Society of North America (RSNA) registrants visited the CSE, the findings presented are promising and suggest that CSE presence at national meetings is justifiable, providing a "first step" toward CME outcomes analysis of CSE. Overall, these findings are promising and suggest that computer scientific exhibit presence at national meetings is justifiable.

Audiovisual Aids↗

delta-Aminolevulinate dehydratase (ALAD) porphyria: the first case in North America with two novel ALAD mutations.

The molecular basis of the enzymatic defect responsible for delta-aminolevulinate dehydratase (ALAD) porphyria (ADP) was investigated in a 14-year-old male who presented clinical and laboratory findings typical of ADP. Nucleotide sequence analysis of ALAD cDNAs from the proband revealed two novel mutations, a 265G to A base transition (C1) and a 394C to T base transition (C2), resulting in amino acid substitutions, Glu89Lys and Cys132Arg, respectively. Both mutations were present within exon 5 of the ALAD gene, and appeared to influence the binding of zinc to the enzyme which is essential for enzyme activity. It was found that the C1 mutation was inherited from his father, while the C2 mutation was from his mother. Expression of these mutant ALAD cDNAs in Chinese hamster ovary cells produced normal ALAD mRNA levels, but markedly decreased ALAD protein and enzyme activity. These results suggest that the combination of the two aberrant ALADs with little enzyme activity accounts for the markedly decreased ALAD activity observed in the proband. This case represents the molecular analysis of the ALAD gene defects in the first case of ADP identified in North America, who is a compound heterozygote for two novel ALAD gene defects.

Adolescent↗

Molecular epidemiology of urinary tract isolates of vancomycin-resistant Enterococcus faecium from North America.

Vancomycin-resistant Enterococcus faecium (VRE) are a common cause of nosocomial infections and are important agents of gastrointestinal colonisation. As the prevalence of VRE in hospitalised patients continues to increase, implementation of appropriate infection control measures requires routine surveillance of VRE transmission patterns. The purpose of the present study was to investigate the molecular epidemiology of VRE isolates within the USA and Canada. Two hundred and eighty-three urinary tract isolates of VRE were collected in the year 2000 from ten Canadian hospitals and 28 US tertiary care medical centres representing seven of the nine geographic regions of the United States Bureau of the Census. The in vitro activity of vancomycin, teicoplanin and nine comparators was determined by broth microdilution. The genetic relatedness among isolates was evaluated by pulsed-field gel electrophoresis (PFGE). Resistance rates (intermediate and resistant) were 100% for vancomycin and 78.7% for teicoplanin. Resistance was lowest with linezolid, chloramphenicol and nitrofurantoin at 0.3%, 0.3% and 0.5%, respectively. PFGE revealed that genetic heterogeneity amongst isolates from each of the medical centres varied considerably. Despite some intracentre and intercentre VRE dissemination, the present study found no evidence for the emergence of a dominant clonal strain. This suggests that the spread of VRE within North America is a complex process involving both the horizontal transfer of glycopeptide resistance determinants and polyclonal dissemination.

Canada↗

[Regulation of reproductive medicine in North America or the Wild West of Medicine (Part I)].

The objective of this work is to offer a general introduction of the legal regulation of the Reproductive Medicine that is practiced in the United States of America. In the United States, besides the Federal Administration, there are also fifty state juridical instances who have competence in Assisted Reproduction subjects. The first section studies the limits of the Right to Reproduction. The American Constitution, interpreted by the Supreme Court, has been useful to establish the limits. Then, will be analyzed the reasons that have been taken by the legislator to adopt a permission with regard to issues appeared by the Medicine of the Fertility. Once studied the general context of the regulation of the Procreation Technology, it is exposed the state legislation and jurisprudence about the matter, and it is also made a review to the most relevant doctrine opinions of the american jurist in relation to Assistance to Reproduction. The cultural and juridical answers that these new clinic methods have used to control, improve or limit the reproduction capacity of human beings are almost as interesting as the Reproductive Technology. Contrary to what happens in Europe, where the legislator has firmly establish the regulation of the Reproductive Medicine since the late 80's, in North-America the lack of regulation has caused a free market where all kind of treatments of fertility are offered, just up to the point that an American author has called the sector "wild west of the Medicine".

Human Rights↗

Genomic sequences of low-virulence avian paramyxovirus-1 (Newcastle disease virus) isolates obtained from live-bird markets in North America not related to commonly utilized commercial vaccine strains.

Avian paramyxovirus 1 (APMV-1), also referred to as Newcastle disease virus (NDV), variants of low virulence were isolated from chickens, ducks and other unidentified species found in live-bird markets of the northeastern United States. These isolates were characterized as APMV-1 by the hemagglutination-inhibition (HI) assay utilizing NDV-specific polyclonal antisera. However, the isolates failed to react with a monoclonal antibody that has specificity for a wide variety of APMV-1 isolates. Although only highly virulent isolates require reporting to international regulatory agencies, the ability to correctly identify APMV-1 types is important for control and regulatory purposes. Protein gel patterns of the purified isolates resembled previously reported APMV-1 and anti-NDV polyclonal sera recognized the viral proteins. For three isolates oligonucleotide primers specific for the nucleoprotein, fusion protein and polymerase genes of NDV were utilized to synthesize cDNA using viral RNA as a template. Approximately 12kb of the genome was subsequently sequenced for the three isolates that included the nucleoprotein, phosphoprotein, matrix protein, fusion (F) protein, hemagglutinin-neuraminidase protein genes and a 5' portion of the polymerase gene. The isolates had an F protein cleavage site sequence of ERQER/LVG indicating low-virulence viruses that phylogenetically separated with other unique NDV isolates designated as a lineage 6 genotype. Additionally, a four amino acid insert was detected in the predicted phosphoprotein which complies with the "rule of six" among paramyxoviruses. These APMV-1 genotypes have not been previously reported in North America and further substantiate the heterogeneous genetic nature of these commercially important pathogens found worldwide.

Amino Acid Sequence↗

Former diversity of Ephedra (Gnetales): evidence from Early Cretaceous seeds from Portugal and North America.

BACKGROUND AND AIMS: The extant species of the seed plant group Gnetales (Ephedra, Gnetum and Welwitschia) have been considered a remnant of a much greater, now extinct, diversity due to the pronounced differences in form and ecology among the genera. Until recently, this hypothesis has not been supported by evidence from the fossil record. This paper adds to the expanding information on Gnetales from the Early Cretaceous and describes coalified seeds from Barremian-Albian localities in Portugal and USA. METHODS: The fossils were extracted from sediment samples by sieving in water. Adhering mineral matrix was removed by chemical treatment. Seeds were investigated using light and scanning electron microscopy. Morphology and anatomy of the seeds were documented and compared with those of extant species. KEY RESULTS: The fossils share characters with extant Ephedra, for example papillae on the inner surface of the seed envelope and in situ polyplicate pollen grains that shed the exine during germination. They differ from extant Ephedra seeds in morphological and anatomical details as well as in their smaller size. Two new species of Ephedra are described together with one species assigned to a new genus of Gnetales. Other Ephedra-like seeds, for which pollen and critical morphological details are currently unknown, are also present in the samples. CONCLUSIONS: These Cretaceous seeds document that key reproductive characters and pollen germination processes have remained unchanged within Ephedra for about 120 million years or more. There is sufficient variety in details of morphology to suggest that a diversity of Ephedra and Ephedra-like species were present in the Early Cretaceous flora. Their presence in Portugal and eastern North America indicates that they were widespread on the Laurasian continent. The fossil seeds are similar to seeds of Erdtmanithecales and this supports the previously suggested relationship between Erdtmanithecales and Gnetales.

Biological Evolution↗

Bacterial pathogens isolated from patients with skin and soft tissue infections: frequency of occurrence and antimicrobial susceptibility patterns from the SENTRY Antimicrobial Surveillance Program (United States and Canada, 1997). SENTRY Study Group (North America).

As part of the SENTRY Antimicrobial Surveillance Program, 1562 bacterial isolates were recovered from hospitalized patients with skin and soft tissue infections (SSTIs) in 30 United States (U.S.) and 8 Canadian medical centers between October and December, 1997. The overall rank order of recovery of the six most common pathogens was Staphylococcus aureus (42.6%) > Pseudomonas aeruginosa (11.3%) > Enterococcus spp. (8.1%) > Escherichia coli (7.2%) > Enterobacter spp. (5.2%) > beta-hemolytic streptocci (5.1%). With one exception, essentially the same order was observed in both the U.S. and Canada. The single exception was the Enterococcus group, which were the third most common isolate in the U.S. (9.6%), but the seventh most common isolate in Canada (3.7). Of note, 24.0% of S. aureus isolates were oxacillin resistant; vancomycin was uniformly active. Vancomycin resistance among Enterococcus spp. (16.5%) was observed only in the U.S. Several antimicrobial agents remained broadly active for SSTI isolates of P. aeruginosa, including meropenem, amikacin, tobramycin, and piperacillin with or without tazobactam. Imipenem resistance (MICs, > or = 8 micrograms/mL) was observed in 11.9% of isolates of P. aeruginosa and ceftazidime, and cefepime had equivalent activity (85.2% and 85.8% susceptible, respectively). Numerous beta-lactams, aminoglycosides and fluoroquinolones were broadly active against E. coli SSTI isolates (i.e. < 5% resistance). Extended-spectrum beta-lactamase production was uncommon both with E. coli and Klebsiella spp. in both nations. Cefepime, imipenem, and meropenem; the aminoglycosides; and fluoroquinolones were conspicuously more active against Enterobacter spp. than other agents tested. High-level, stably derepressed Amp C beta-lactamase production was commonly observed in this group (26.8%), but cefepime generally retained activity against these ceftazidime-resistant organisms. The results of this study serve to define the most common bacterial causes of SSTIs in North America, elucidate patterns of antimicrobial resistance and can be used as a basis for making initial empiric antimicrobial management decisions in hospitalized patients with such infections.

Anti-Bacterial Agents↗

Internationalization of general surgical journals: origin and content of articles published in North America and Great Britain from 1983 to 1998.

HYPOTHESIS: The origin and characteristics of articles published in the 6 highest rated (Institute for Scientific Information classification) English-language general surgical journals have changed significantly during the past 15 years. DESIGN: All articles published in 1983, 1988, 1993, and 1998 in 5 US surgical journals and 1 British surgical journal were reviewed and characterized. MAIN OUTCOME MEASURES: Absolute numbers and proportions of national and international articles published in each journal. RESULTS: Articles reviewed included 4868 in US journals and 1380 in the British journal. The total number of US journal articles decreased by 15.1%. The total number of British journal articles increased by 58.9%. The percentage of national articles decreased from 87.5% to 68.8% in US journals (P<.001) and constituted the minority of freely submitted articles in 1998 in 3 of 5 US journals. The percentage of national articles also decreased from 74.8% to 47.1% in the British journal (P<.001). Articles by European and Asian authors showed the most striking increases in all journals. The percentage of basic research articles declined in US journals from 23.3% to 17.9% (P =.001) owing to a 14.9% decline in national basic research articles. The percentage of clinical randomized studies increased from 2.2% to 4.1% (P<.008), but the increase was attributable to international articles. Government funding alone decreased from 13.6% to 11.2%, and government plus another source of funding decreased from 19.2% to 16.7% for national articles in US journals. CONCLUSIONS: Internationalization of the highly rated British and the 5 highest rated US general surgical journals has occurred. The decrease in the number of national articles in the US journals has been accompanied by significant decreases in government funding and basic research articles and a static output of clinical randomized studies from North America.

Authorship↗