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1.
J Urban Health ; 99(1): 28-54, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34997433

RESUMO

We reviewed research that examines racism as an independent variable and one or more health outcomes as dependent variables in Black American adults aged 50 years and older in the USA. Of the 43 studies we reviewed, most measured perceived interpersonal racism, perceived institutional racism, or residential segregation. The only two measures of structural racism were birth and residence in a "Jim Crow state." Fourteen studies found associations between racism and mental health outcomes, five with cardiovascular outcomes, seven with cognition, two with physical function, two with telomere length, and five with general health/other health outcomes. Ten studies found no significant associations in older Black adults. All but six of the studies were cross-sectional. Research to understand the extent of structural and multilevel racism as a social determinant of health and the impact on older adults specifically is needed. Improved measurement tools could help address this gap in science.


Assuntos
Racismo , Segregação Social , Negro ou Afro-Americano/psicologia , Idoso , População Negra , Humanos , Pessoa de Meia-Idade , Racismo/psicologia , Racismo Sistêmico
2.
Stud Mycol ; 100: 100131, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34934463

RESUMO

Paracoccidioidomycosis (PCM) is a life-threatening systemic fungal infection acquired after inhalation of Paracoccidioides propagules from the environment. The main agents include members of the P. brasiliensis complex (phylogenetically-defined species S1, PS2, PS3, and PS4) and P. lutzii. DNA-sequencing of protein-coding loci (e.g., GP43, ARF, and TUB1) is the reference method for recognizing Paracoccidioides species due to a lack of robust phenotypic markers. Thus, developing new molecular markers that are informative and cost-effective is key to providing quality information to explore genetic diversity within Paracoccidioides. We report using new amplified fragment length polymorphism (AFLP) markers and mating-type analysis for genotyping Paracoccidioides species. The bioinformatic analysis generated 144 in silico AFLP profiles, highlighting two discriminatory primer pairs combinations (#1 EcoRI-AC/MseI-CT and #2 EcoRI-AT/MseI-CT). The combinations #1 and #2 were used in vitro to genotype 165 Paracoccidioides isolates recovered from across a vast area of South America. Considering the overall scored AFLP markers in vitro (67-87 fragments), the values of polymorphism information content (PIC = 0.3345-0.3456), marker index (MI = 0.0018), effective multiplex ratio (E = 44.6788-60.3818), resolving power (Rp = 22.3152-34.3152), discriminating power (D = 0.5183-0.5553), expected heterozygosity (H = 0.4247-0.4443), and mean heterozygosity (H avp  = 0.00002-0.00004), demonstrated the utility of AFLP markers to speciate Paracoccidioides and to dissect both deep and fine-scale genetic structures. Analysis of molecular variance (AMOVA) revealed that the total genetic variance (65-66 %) was due to variability among P. brasiliensis complex and P. lutzii (PhiPT = 0.651-0.658, P < 0.0001), supporting a highly structured population. Heterothallism was the exclusive mating strategy, and the distributions of MAT1-1 or MAT1-2 idiomorphs were not significantly skewed (1:1 ratio) for P. brasiliensis s. str. (χ2 = 1.025; P = 0.3113), P. venezuelensis (χ2 = 0.692; P = 0.4054), and P. lutzii (χ2 = 0.027; P = 0.8694), supporting random mating within each species. In contrast, skewed distributions were found for P. americana (χ2 = 8.909; P = 0.0028) and P. restrepiensis (χ2 = 4.571; P = 0.0325) with a preponderance of MAT1-1. Geographical distributions confirmed that P. americana, P. restrepiensis, and P. lutzii are more widespread than previously thought. P. brasiliensis s. str. is by far the most widely occurring lineage in Latin America countries, occurring in all regions of Brazil. Our new DNA fingerprint assay proved to be rapid, reproducible, and highly discriminatory, to give insights into the taxonomy, ecology, and epidemiology of Paracoccidioides species, guiding disease-control strategies to mitigate PCM.

3.
JAC Antimicrob Resist ; 3(1): dlab026, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34223100

RESUMO

BACKGROUND: Individuals with cystic fibrosis (CF) have an increased susceptibility to fungal infection/allergy, with triazoles often used as first-line therapy. Therapeutic drug monitoring (TDM) is essential due to significant pharmacokinetic variability and the recent emergence of triazole resistance worldwide. OBJECTIVES: In this retrospective study we analysed the 'real-world' TDM of azole therapy in a large CF cohort, risk factors for subtherapeutic dosing, and the emergence of azole resistance. METHODS: All adults with CF on azole therapy in a large single UK centre were included. Clinical demographics, TDM and microbiology were analysed over a 2 year study period (2015-17) with multivariate logistic regression used to identify risk factors for subtherapeutic dosing. RESULTS: 91 adults were treated with azole medication during the study period. A high prevalence of chronic subtherapeutic azole dosing was seen with voriconazole (60.8%) and itraconazole capsule (59.6%) use, representing significant risk factors for subtherapeutic levels. Rapid emergence of azole resistance was additionally seen over the follow-up period with a 21.4% probability of CF patients developing a resistant fungal isolate after 2 years. No significant relationship was found however between subtherapeutic azole dosing and azole resistance emergence. CONCLUSIONS: Our study demonstrates a high prevalence of subtherapeutic azole levels in CF adults with increased risk using itraconazole capsules and voriconazole therapy. We show rapid emergence of azole resistance highlighting the need for effective antifungal stewardship. Further large longitudinal studies are needed to understand the effects of antifungal resistance on outcome in CF and the implications of subtherapeutic dosing on resistance evolution.

5.
Stud Mycol ; 100: 100129, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35027980

RESUMO

Sporothrix (Ophiostomatales) comprises species that are pathogenic to humans and other mammals as well as environmental fungi. Developments in molecular phylogeny have changed our perceptions about the epidemiology, host-association, and virulence of Sporothrix. The classical agent of sporotrichosis, Sporothrix schenckii, now comprises several species nested in a clinical clade with S. brasiliensis, S. globosa, and S. luriei. To gain a more precise view of outbreaks dynamics, structure, and origin of genetic variation within and among populations of Sporothrix, we applied three sets of discriminatory AFLP markers (#3 EcoRI-GA/MseI-TT, #5 EcoRI-GA/MseI-AG, and #6 EcoRI-TA/MseI-AA) and mating-type analysis to a large collection of human, animal and environmental isolates spanning the major endemic areas. A total of 451 polymorphic loci were amplified in vitro from 188 samples, and revealed high polymorphism information content (PIC = 0.1765-0.2253), marker index (MI = 0.0001-0.0002), effective multiplex ratio (E = 15.1720-23.5591), resolving power (Rp = 26.1075-40.2795), discriminating power (D = 0.9766-0.9879), expected heterozygosity (H = 0.1957-0.2588), and mean heterozygosity (Havp  = 0.000007-0.000009), demonstrating the effectiveness of AFLP markers to speciate Sporothrix. Analysis using the program structure indicated three genetic clusters matching S. brasiliensis (population 1), S. schenckii (population 2), and S. globosa (population 3), with the presence of patterns of admixture amongst all populations. AMOVA revealed highly structured clusters (PhiPT = 0.458-0.484, P < 0.0001), with roughly equivalent genetic variability within (46-48 %) and between (52-54 %) populations. Heterothallism was the exclusive mating strategy, and the distributions of MAT1-1 or MAT1-2 idiomorphs were not significantly skewed (1:1 ratio) for S. schenckii (χ2 = 2.522; P = 0.1122), supporting random mating. In contrast, skewed distributions were found for S. globosa (χ2 = 9.529; P = 0.0020) with a predominance of MAT1-1 isolates, and regional differences were highlighted for S. brasiliensis with the overwhelming occurrence of MAT1-2 in Rio de Janeiro (χ2 = 14.222; P = 0.0002) and Pernambuco (χ2 = 7.364; P = 0.0067), in comparison to a higher prevalence of MAT1-1 in the Rio Grande do Sul (χ2 = 7.364; P = 0.0067). Epidemiological trends reveal the geographic expansion of cat-transmitted sporotrichosis due to S. brasiliensis via founder effect. These data support Rio de Janeiro as the centre of origin that has led to the spread of this disease to other regions in Brazil. Our ability to reconstruct the source, spread, and evolution of the ongoing outbreaks from molecular data provides high-quality information for decision-making aimed at mitigating the progression of the disease. Other uses include surveillance, rapid diagnosis, case connectivity, and guiding access to appropriate antifungal treatment.

6.
Stud Mycol ; 97: 100095, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33335607

RESUMO

Histoplasmosis is a serious infectious disease in humans caused by Histoplasma spp. (Onygenales), whose natural reservoirs are thought to be soil enriched with bird and bat guano. The true global burden of histoplasmosis is underestimated and frequently the pulmonary manifestations are misdiagnosed as tuberculosis. Molecular data on epidemiology of Histoplasma are still scarce, even though there is increasing recognition of histoplasmosis in recent years in areas distant from the traditional endemic regions in the Americas. We used multi-locus sequence data from protein coding loci (ADP-ribosylation factor, H antigen precursor, and delta-9 fatty acid desaturase), DNA barcoding (ITS1/2+5.8s), AFLP markers and mating type analysis to determine the genetic diversity, population structure and recognise the existence of different phylogenetic species among 436 isolates of Histoplasma obtained globally. Our study describes new phylogenetic species and the molecular characteristics of Histoplasma lineages causing outbreaks with a high number of severe outcomes in Northeast Brazil between 2011 and 2015. Genetic diversity levels provide evidence for recombination, common ancestry and clustering of Brazilian isolates at different geographic scales with the emergence of LAm C, a new genotype assigned to a separate population cluster in Northeast Brazil that exhibited low diversity indicative of isolation. The global survey revealed that the high genetic variability among Brazilian isolates along with the presence of divergent cryptic species and/or genotypes may support the hypothesis of Brazil being the center of dispersion of Histoplasma in South America, possibly with the contribution of migratory hosts such as birds and bats. Outside Brazil, the predominant species depends on the region. We confirm that histoplasmosis has significantly broadened its area of occurrence, an important feature of emerging pathogens. From a practical point of view, our data point to the emergence of histoplasmosis caused by a plethora of genotypes, and will enable epidemiological analysis focused on understanding the processes that lead to histoplasmosis. Further, the description of this diversity opens avenues for comparative genomic studies, which will allow progress toward a consensus taxonomy, improve understanding of the presence of hybrids in natural populations of medically relevant fungi, test reproductive barriers and to explore the significance of this variation.

7.
Transbound Emerg Dis ; 65(2): 309-314, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29205924

RESUMO

Emerging fungal diseases represent a threat to food security, animal and human health worldwide. Amphibian chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has been associated with catastrophic and well-documented amphibian population declines and extinctions. For the first time, Bd was cultured from native and non-native wild amphibians in Chile. Phylogenomic analyses revealed that Chilean isolates AVS2, AVS4 and AVS7 group within the global panzootic lineage of Bd (BdGPL) in a single highly supported clade that includes a genotype previously isolated from the United Kingdom. Our results extend the known distribution of BdGPL in South America and suggest a single and relatively recent introduction of BdGPL into the country, providing additional support to the role of anthropogenic activity in the global spread of this panzootic lineage.


Assuntos
Quitridiomicetos/genética , Doenças Transmissíveis Emergentes/veterinária , Genoma Fúngico/genética , Genômica , Micoses/epidemiologia , Micoses/veterinária , Xenopus laevis/microbiologia , Anfíbios , Animais , Animais Selvagens/microbiologia , Chile/epidemiologia , Quitridiomicetos/isolamento & purificação , DNA Fúngico/genética , Genótipo , Espécies Introduzidas
8.
Science ; 346(6209): 630-1, 2014 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-25359973

RESUMO

Emerging infectious diseases are reducing biodiversity on a global scale. Recently, the emergence of the chytrid fungus Batrachochytrium salamandrivorans resulted in rapid declines in populations of European fire salamanders. Here, we screened more than 5000 amphibians from across four continents and combined experimental assessment of pathogenicity with phylogenetic methods to estimate the threat that this infection poses to amphibian diversity. Results show that B. salamandrivorans is restricted to, but highly pathogenic for, salamanders and newts (Urodela). The pathogen likely originated and remained in coexistence with a clade of salamander hosts for millions of years in Asia. As a result of globalization and lack of biosecurity, it has recently been introduced into naïve European amphibian populations, where it is currently causing biodiversity loss.


Assuntos
Quitridiomicetos , Doenças Transmissíveis Emergentes/veterinária , Espécies em Perigo de Extinção , Micoses/veterinária , Urodelos/microbiologia , Animais , Biodiversidade , Doenças Transmissíveis Emergentes/microbiologia , Micoses/microbiologia , Filogenia , Urodelos/classificação
9.
Mol Ecol ; 20(20): 4288-301, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21951491

RESUMO

Eighty years ago, Alexander Fleming described the antibiotic effects of a fungus that had contaminated his bacterial culture, kick starting the antimicrobial revolution. The fungus was later ascribed to a putatively globally distributed asexual species, Penicillium chrysogenum. Recently, the species has been shown to be genetically diverse, and possess mating-type genes. Here, phylogenetic and population genetic analyses show that this apparently ubiquitous fungus is actually composed of at least two genetically distinct species with only slight differences detected in physiology. We found each species in air and dust samples collected in and around St Mary's Hospital where Fleming worked. Genotyping of 30 markers across the genome showed that preserved fungal material from Fleming's laboratory was nearly identical to derived strains currently in culture collections and in the same distinct species as a wild progenitor strain of current penicillin producing industrial strains rather than the type species P. chrysogenum. Global samples of the two most common species were found to possess mating-type genes in a near 1:1 ratio, and show evidence of recombination with little geographic population subdivision evident. However, no hybridization was detected between the species despite an estimated time of divergence of less than 1MYA. Growth studies showed significant interspecific inhibition by P. chrysogenum of the other common species, suggesting that competition may facilitate species maintenance despite globally overlapping distributions. Results highlight under-recognized diversity even among the best-known fungal groups and the potential for speciation despite overlapping distribution.


Assuntos
Especiação Genética , Penicillium chrysogenum/genética , Filogenia , Genes Fúngicos Tipo Acasalamento/genética , Genética Populacional , Humanos , Dados de Sequência Molecular
10.
Clin Exp Rheumatol ; 27(3): 395-401, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19604430

RESUMO

OBJECTIVE: To examine effects of the COX-2 inhibitor market withdrawals on NSAID utilization among patients at increased risk of gastrointestinal (GI) and cardiovascular (CV) toxicities. METHODS: A prospective cohort study was conducted using patients enrolled in the Consortium of Rheumatology Researchers of North America (CORRONA) Registry. The study population included rheumatoid arthritis (RA) and psoriatic arthritis (PsA) patients prescribed NSAIDs by rheumatologists from 1/1/2003 to 12/31/2005. Three cohorts were defined based on calendar year. The primary outcome assessed whether or not an NSAID gastroprotective strategy was prescribed. Secondary outcomes included rates of COX-2 inhibitor utilization and gastroprotective co-therapy utilization, stratified by the presence of cardiac and GI risk factors. RESULTS: NSAID gastroprotection utilization decreased from 65.1% in 2003 to 47.7% (p<0.001) in 2005. COX-2 inhibitor use decreased from 55.1% to 29.2% (p<0.001), whereas nonselective NSAIDs (nsNSAIDs) use increased from 50.2% to 73.9% (p=<0.01). Among patients with two or more risk factors for NSAID related GI bleeding, gastroprotection decreased from 74.4% in 2003 to 60.9% (p<0.01). For patients with two or more CV risk factors from 2003 to 2005, COX-2 inhibitor utilization decreased significantly, whereas nsNSAID utilization increased significantly. CONCLUSIONS: The COX-2 inhibitor withdrawals resulted in a rapid decline in NSAID gastroprotection prescribed by participating U.S. rheumatologists despite the availability of other gastroprotective options. Channeling toward nsNSAID use was widespread, including among patients at increased CV risk. Longer term follow-up is required to determine the clinical significance of these changes in NSAID prescribing, particularly for NSAID-related GI and CV-related toxicities.


Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Doenças Cardiovasculares/induzido quimicamente , Doenças Cardiovasculares/epidemiologia , Inibidores de Ciclo-Oxigenase 2/efeitos adversos , Gastroenteropatias/induzido quimicamente , Gastroenteropatias/epidemiologia , Adulto , Idoso , Anti-Inflamatórios não Esteroides/uso terapêutico , Artrite Psoriásica/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Estudos de Coortes , Inibidores de Ciclo-Oxigenase 2/uso terapêutico , Uso de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sistema de Registros , Fatores de Risco , Resultado do Tratamento , Estados Unidos
11.
Dis Aquat Organ ; 84(2): 163-6, 2009 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-19476287

RESUMO

Chytridiomycosis, an emerging infectious disease of amphibians caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd), is associated with amphibian population declines worldwide. Investigation of the origin and spread of the pathogen requires examination of archived museum specimens of amphibians. Examination for Bd infection is usually done using histological techniques, which are often too destructive for valuable museum material. Three alternative methods for Bd detection (skin swabbing, brushing and scraping) were evaluated for ability to yield Bd DNA and destructiveness to specimens. Archived amphibians known to be Bd positive and which had been preserved in either formalin or ethanol for many years were used. Samples were analysed using a Bd-specific quantitative real-time Taqman PCR (qPCR) assay. There was no difference in the ability of each of the techniques to detect Bd infection, with the pathogen being detected in 75 to 81% of the 16 ethanol-fixed frogs examined. Visible evidence of sampling was left by scraping, but not by swabbing or brushing. The brush-qPCR technique detected higher counts of genomic equivalents than the other 2 sampling methods, although differences were not statistically significant. The qPCR assay did not detect Bd from any of the 6 formalin-fixed frogs examined, regardless of the sampling method. Nondestructive sampling techniques enable qPCR analysis of ethanol-preserved museum specimens for Bd. Recently, the incorporation of DNA cleanup steps allowed the detection of Bd in destructively sampled tissues from formalin preserved specimens. Further studies using nondestructive sampling incorporating DNA cleanup steps for the detection of Bd in formalin preserved specimens are warranted.


Assuntos
Anfíbios/microbiologia , Quitridiomicetos/isolamento & purificação , Animais , Etanol , Formaldeído , Museus , Sensibilidade e Especificidade , Manejo de Espécimes
12.
Dis Aquat Organ ; 83(3): 257-60, 2009 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-19402457

RESUMO

Batrachochytrium dendrobatidis (Bd) is a global threat to amphibian biodiversity. Current calls for conservation through captive breeding require that efficient and reliable antifungal treatments be developed for target species. Here we confirm that the antifungal itraconazole is an effective treatment for infection in larval Alytes muletensis. Exceptionally low doses applied as few as 7 times were effective at clearing infection from tadpoles for up to 28 d after treatment. However, we cannot recommend itraconazole as a treatment for this species as depigmentation of tadpoles was observed. Further research is required to determine the putative hepatotoxicity of this treatment.


Assuntos
Anuros/fisiologia , Quitridiomicetos/efeitos dos fármacos , Itraconazol/efeitos adversos , Itraconazol/uso terapêutico , Micoses/veterinária , Animais , Antifúngicos/efeitos adversos , Antifúngicos/uso terapêutico , Micoses/tratamento farmacológico , Pigmentos Biológicos
13.
Med Mycol ; 45(5): 385-93, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17654264

RESUMO

The ribosomal Internal Transcribed Spacer (ITS) regions of the two recognized species of Coccidioides were studied using a reference set of strains that had been previously identified with species defining microsatellite polymorphisms. Unambiguous identification of the two species proved to be possible by amplifying and sequencing the ITS region. PCR-reactions are sensitive to amplification conditions requiring their careful optimization. Stable amplification and sequencing was achieved with primers ITS3 and 4, enabling species diagnosis. Alternatively, Restriction Fragment Length Polymorphism (RFLP) of the entire ITS region using an annealing temperature of 52 degrees C with the restriction enzymes BsrI and XcmI can also distinguish the species. Three strains typifying the species, Glenospora meteuropaea, G. metamericana and Geotrichum louisianoideum, were analyzed and found to be conspecific with C. posadasii. Although these species have nomenclatural priority over C. posadasii, the latter will be proposed for conservation as it has been included in the US select agent list. In addition, Coccidioides immitis is neotypified in this report. Results of antifungal susceptibility testing did not reveal differences between the two species.


Assuntos
Coccidioides/classificação , Coccidioidomicose/diagnóstico , DNA Espaçador Ribossômico/análise , Marcadores Genéticos , Antifúngicos/farmacologia , Coccidioides/efeitos dos fármacos , Coccidioides/genética , Coccidioidomicose/microbiologia , Primers do DNA , DNA Fúngico/análise , DNA Fúngico/genética , DNA Fúngico/isolamento & purificação , Humanos , Testes de Sensibilidade Microbiana , Técnicas de Tipagem Micológica , Polimorfismo de Fragmento de Restrição , Especificidade da Espécie
14.
Science ; 315(5814): 998-1000, 2007 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-17303757

RESUMO

Chemoautotrophic endosymbionts are the metabolic cornerstone of hydrothermal vent communities, providing invertebrate hosts with nearly all of their nutrition. The Calyptogena magnifica (Bivalvia: Vesicomyidae) symbiont, Candidatus Ruthia magnifica, is the first intracellular sulfur-oxidizing endosymbiont to have its genome sequenced, revealing a suite of metabolic capabilities. The genome encodes major chemoautotrophic pathways as well as pathways for biosynthesis of vitamins, cofactors, and all 20 amino acids required by the clam.


Assuntos
Bivalves/microbiologia , Gammaproteobacteria/genética , Genoma Bacteriano , Simbiose , Animais , Carbono/metabolismo , Crescimento Quimioautotrófico , Gammaproteobacteria/isolamento & purificação , Gammaproteobacteria/metabolismo , Gammaproteobacteria/ultraestrutura , Dados de Sequência Molecular , Fotossíntese
16.
Mycologia ; 94(1): 73-84, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-21156479

RESUMO

Coccidioides posadasii sp. nov., formerly known as non-California (non-CA) Coccidioides immitis, is described. Phylogenetic analyses using single nucleotide polymorphisms, genes, and microsatellites show that C. posadasii represents a divergent, genetically recombining monophyletic clade. Coccidioides posadasii can be distinguished from C. immitis by numerous DNA polymorphisms, and we show how either of two microsatellite loci may be used as diagnostic markers for this species. Growth experiments show that C. posadasii has significantly slower growth rates on high-salt media when compared with C. immitis, suggesting that other phenotypic characters may exist.

17.
J Midwifery Womens Health ; 46(5): 313-20, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11725904

RESUMO

The American College of Nurse-Midwives (ACNM) Certification Council periodically conducts a task analysis study as evidence supporting the content validity of the national certification examination in nurse-midwifery and midwifery. The purpose of this article is to report findings related to the examination of the relationship between professional issues and safe beginning-level midwifery as measured by the 1999-2000 Task Analysis of American Nurse Midwifery and Midwifery Practice. Study findings suggest that newly certified midwives place strong emphasis on the importance of tasks related to the ACNM "Hallmarks of Midwifery," which characterize the art and science of the profession: these include tasks dealing with health promotion and cultural competency. The beginning midwives, however, gave consistently low ratings to tasks related to ACNM "Core Competencies" that mirror the professional responsibilities of midwives; these include tasks related to the history of midwifery, research, or health policy. The study has implications for nurse-midwifery/midwifery educators, experienced midwifery mentors, and other persons interested in reinforcing the relevance of these important professional issues to the new midwife.


Assuntos
Tocologia/educação , Tocologia/normas , Adulto , Certificação , Feminino , Grupos Focais , Humanos , Projetos Piloto , Gravidez , Reprodutibilidade dos Testes , Análise e Desempenho de Tarefas
19.
Teratology ; 64(2): 114-22, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11460263

RESUMO

BACKGROUND: Choline is an essential nutrient in methylation, acetylcholine and phospholipid biosynthesis, and in cell signaling. The demand by an embryo or fetus for choline may place a pregnant woman and, subsequently, the developing conceptus at risk for choline deficiency. METHODS: To determine whether a disruption in choline uptake and metabolism results in developmental abnormalities, early somite staged mouse embryos were exposed in vitro to either an inhibitor of choline uptake and metabolism, 2-dimethylaminoethanol (DMAE), or an inhibitor of phosphatidylcholine synthesis, 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine (ET-18-OCH(3)). Cell death following inhibitor exposure was investigated with LysoTracker Red and histology. RESULTS: Embryos exposed to 250-750 microM DMAE for 26 hr developed craniofacial hypoplasia and open neural tube defects in the forebrain, midbrain, and hindbrain regions. Embryos exposed to 125-275 microM ET-18-OCH(3) exhibited similar defects or expansion of the brain vesicles. ET-18-OCH(3)-affected embryos also had a distended neural tube at the posterior neuropore. Embryonic growth was reduced in embryos treated with either DMAE (375, 500, and 750 microM) or ET-18-OCH(3) (200 and 275 microM). Whole mount staining with LysoTracker Red and histological sections showed increased areas of cell death in embryos treated with 275 microM ET-18-OCH(3) for 6 hr, but there was no evidence of cell death in DMAE-exposed embryos. CONCLUSIONS: Inhibition of choline uptake and metabolism during neurulation results in growth retardation and developmental defects that affect the neural tube and face.


Assuntos
Anormalidades Induzidas por Medicamentos/etiologia , Antidiscinéticos/toxicidade , Colina/antagonistas & inibidores , Colina/metabolismo , Deanol/toxicidade , Embrião de Mamíferos/efeitos dos fármacos , Desenvolvimento Embrionário e Fetal/efeitos dos fármacos , Defeitos do Tubo Neural/induzido quimicamente , Animais , Embrião de Mamíferos/patologia , Feminino , Masculino , Camundongos , Defeitos do Tubo Neural/embriologia , Defeitos do Tubo Neural/patologia , Técnicas de Cultura de Órgãos , Inibidores de Fosfodiesterase/farmacologia , Inibidores de Fosfodiesterase/toxicidade , Éteres Fosfolipídicos/farmacologia , Éteres Fosfolipídicos/toxicidade , Gravidez
20.
Proc Natl Acad Sci U S A ; 98(8): 4558-62, 2001 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-11287648

RESUMO

Long-distance population dispersal leaves its characteristic signature in genomes, namely, reduced diversity and increased linkage between genetic markers. This signature enables historical patterns of range expansion to be traced. Herein, we use microsatellite loci from the human pathogen Coccidioides immitis to show that genetic diversity in this fungus is geographically partitioned throughout North America. In contrast, analyses of South American C. immitis show that this population is genetically depauperate and was founded from a single North American population centered in Texas. Variances of allele distributions show that South American C. immitis have undergone rapid population growth, consistent with an epidemic increase in postcolonization population size. Herein, we estimate the introduction into South America to have occurred within the last 9,000-140,000 years. This range increase parallels that of Homo sapiens. Because of known associations between Amerindians and this fungus, we suggest that the colonization of South America by C. immitis represents a relatively recent and rapid codispersal of a host and its pathogen.


Assuntos
Coccidioides/isolamento & purificação , Migrantes , Sequência de Bases , Portador Sadio , Coccidioidomicose/epidemiologia , Primers do DNA , Geografia , Humanos , Repetições de Microssatélites/genética , América do Norte/epidemiologia , América do Sul/epidemiologia
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