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1.
Clin Infect Dis ; 2023 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-37739479

RESUMEN

BACKGROUND: Public health officials are responding to an outbreak of fungal meningitis among patients who received procedures under epidural anesthesia at two clinics (River Side Surgical Center and Clinica K-3) in Matamoros, Mexico, during January 1-May 13, 2023. This report describes outbreak epidemiology and outlines interim diagnostic and treatment recommendations. METHODS: Interim recommendations for diagnosis and management were developed by the Mycoses Study Group Research Education and Consortium (MSGERC) based on the clinical experience of clinicians caring for patients during the current outbreak or during previous outbreaks of healthcare-associated fungal meningitis in Durango, Mexico, and the United States. RESULTS: As of July 7, 2023, the situation has evolved into a multistate and multinational fungal meningitis outbreak. A total of 185 residents in 22 U.S. states and jurisdictions have been identified who might be at risk of fungal meningitis because they received epidural anesthesia at the clinics of interest in 2023. Among these patients, 11 suspected, 10 probable, and 10 confirmed U.S. cases have been diagnosed, with severe vascular complications and eight deaths occurring. Fusarium solani species complex has been identified as the causative agent, with antifungal susceptibility testing of a single isolate demonstrating poor in vitro activity for most available antifungals. Currently, triple therapy with intravenous voriconazole, liposomal amphotericin B, and fosmanogepix is recommended. CONCLUSIONS: Efforts to understand the source of this outbreak and optimal treatment approaches are ongoing, but infectious diseases physicians should be aware of available treatment recommendations. New information will be available on CDC's website.

2.
Ecol Evol ; 13(2): e9800, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36861027

RESUMEN

Despite significant population declines and targeted European Union regulations aimed at Anguilla anguilla conservation, little attention has been given to their status at their easternmost range. This study applies wide-scale integrated monitoring to uncover the present-day eel distribution in Cyprus' inland freshwaters. These are subject to increasing pressures from water supply requirements and dam construction, as seen throughout the Mediterranean. We applied environmental DNA metabarcoding of water samples to determine A. anguilla distribution in key freshwater catchments. In addition, we present this alongside 10 years of electrofishing/netting data. Refuge traps were also deployed to establish the timing of glass eel recruitment. These outputs are used together, alongside knowledge of the overall fish community and barriers to connectivity, to provide eel conservation and policy insights. This study confirm the presence of A. anguilla in Cyprus' inland freshwaters, with recruitment occurring in March. Eel distribution is restricted to lower elevation areas, and is negatively associated with distance from coast and barriers to connectivity. Many barriers to connectivity are identified, though eels were detected in two reservoirs upstream of dams. The overall fish community varies between freshwater habitat types. Eels are much more widespread in Cyprus than previously thought, yet mostly restricted to lowland intermittent systems. These findings make a case to reconsider the requirement for eel management plans. Environmental DNA-based data collected in 2020 indicate that "present-day" eel distribution is representative of 10-year survey trends. Suggesting that inland freshwaters may act as an unrealized refuge at A. anguilla's easternmost range. Conservation efforts in Mediterranean freshwaters should focus on improving connectivity, therefore enabling eels to access inland perennial refugia. Thus, mitigating the impact of climate change and the growing number of fragmented artificially intermittent river systems.

3.
J Am Acad Orthop Surg ; 31(8): 421-427, 2023 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-36735417

RESUMEN

INTRODUCTION: The importance of sociodemographic factors such as race, education, and income on spine surgery outcomes has been well established, yet the representation of sociodemographic data within randomized controlled trials (RCTs) in spine literature remains undefined in the United States (U.S). METHODS: Medical literature was reviewed within PubMed for RCTs with "spine" in the title or abstract published within the last 8 years (2014 to 2021) in seven major spine journals. This yielded 128 results, and after application of inclusion criteria (RCTs concerning adult spine pathologies conducted in the U.S), 54 RCTs remained for analysis. Each article's journal of publication, year of publication, and spinal pathology was recorded. Pathologies included cervical degeneration, thoracolumbar degeneration, adult deformity, cervical trauma, and thoracolumbar trauma. Sociodemographic variables collected were race, ethnicity, insurance status, income, work status, and education. The Fisher's exact test was used to compare inclusion of sociodemographic data by journal, year, and spinal pathology. RESULTS: Sociodemographic data were included in the results and in any section of 57.4% (31/54) of RCTs. RCTs reported work status in 25.9% (14/54) of results and 38.9% (21/54) of RCTs included work status in any section. Income was included in the results and mentioned in any section in 13.0% (7/54) of RCTs. Insurance status was in the results or any section of 9.3% (5/54) and 18.5% (10/54) of RCTs, respectively. There was no association with inclusion of sociodemographic data within the results of RCTs as a factor of journal ( P = 0.337), year of publication ( P = 0.286), or spinal pathology ( P = 0.199). DISCUSSION: Despite evidence of the importance of sociodemographic factors on the natural history and treatment outcomes of myriad spine pathologies, this study identifies a surprising absence of sociodemographic data within contemporary RCTs in spine surgery. Failure to include sociodemographic factors in RCTs potentially bias the generalizability of outcome data.


Asunto(s)
Etnicidad , Columna Vertebral , Adulto , Humanos , Estados Unidos , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del Tratamiento
4.
Sci Rep ; 12(1): 14871, 2022 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-36050352

RESUMEN

A hotspot of subterranean Collembola in ferruginous rock caves and Mesovoid Shallow Substratum is revealed by the analysis of pseudocryptic diversity. The diversity is accessed by detailed description of chaetotaxy and slight variation in morphology of 11 new species of Trogolaphysa Mills, 1938 (Collembola, Paronellidae, Paronellinae) and the 50 previously recorded species of springtails from caves, using optical and electronic microscopy. When combined with recent subterranean surveys, our results show an important reservoir of cave diversity in the Mesovoid Shallow Substratum. Contrastingly the conservation policy for subterranean fauna in metallogenic areas in Brazil prioritizes the caves instead the cave species, which may be extremely detrimental to the fauna in the shallow subterranean habitats not accessible to humans.


Asunto(s)
Artrópodos , Animales , Artrópodos/anatomía & histología , Brasil , Cuevas , Ecosistema , Humanos , Políticas
5.
J Arthroplasty ; 37(8S): S803-S806, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-34998907

RESUMEN

BACKGROUND: Component positioning in total hip arthroplasty (THA) may be improved with utilization of intraoperative imaging. The purpose of this study is to determine if intraoperative imaging during THA is cost-effective. METHODS: A break-even analysis was used as a model for cost-effectiveness, which incorporates cost of imaging (including direct charges and the additional time required for imaging), rate of revision surgery, and cost of revision surgery, yielding a final revision rate that needs to be achieved with use of intraoperative imaging in order for its use to be cost-effective. Absolute risk reduction (ARR) is determined by the difference between the initial revision rate and final revision rate. RESULTS: At an anticipated institutional cost of $120 and requiring 4 additional minutes, intraoperative fluoroscopy would be cost-effective if the baseline rate of revision due to component mispositioning (0.62%) is reduced to 0.46%. Intraoperative flat plate radiographs ($127) are cost-effective at an ARR of 0.16%. Cost-effectiveness is achieved with lower ARR in the setting of lower imaging costs ($15, ARR 0.02%), and higher ARR with higher imaging costs ($225, ARR 0.29%). ARR for cost-effectiveness is independent of baseline revision rate, but varies with the cost of revision procedures. CONCLUSION: At current revision rates for component malpositioning, only 1 revision among 400 THAs needs to be prevented for the utilization of fluoroscopy (or 1 in 385 THAs with flat plate imaging), to achieve cost-effectiveness.


Asunto(s)
Artroplastia de Reemplazo de Cadera , Prótesis de Cadera , Artroplastia de Reemplazo de Cadera/métodos , Análisis Costo-Beneficio , Fluoroscopía , Humanos , Radiografía , Reoperación
6.
Mycopathologia ; 187(1): 103-111, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34762221

RESUMEN

Cryptococcosis is an infection caused by encapsulated basidiomycetous yeasts belonging to the Cryptococcus neoformans/Cryptococcus gattii species complexes. It is acquired through inhalation of infectious propagules, often resulting in meningitis and meningoencephalitis. The ecological niche of these agents is a wide variety of trees species, as well as pigeon, parrot and passerine excreta. The objective of this study was to isolate Cryptococcus yeasts from excreta of commercially traded parrots and passerines. The 237 samples were collected between October 2018 and April 2019 and processed using conventional methodologies. Nineteen colonies with a dark brown phenotype, caused by phenol oxidase activity, were isolated, suggesting the presence of pathogenic Cryptococcus yeasts. All isolates tested positive for urease activity. URA5-RFLP fingerprinting identified 14 isolates (68.4%) as C. neoformans (genotype AFLP1/VNI) and 5 (26.3%) as C. deuterogattii (genotype AFLP6/VGII). Multi-locus sequence typing was applied to investigate the relatedness of the C. deuterogattii isolates with those collected globally, showing that those originating from bird-excreta were genetically indistinguishable from some clinical isolates collected during the past two decades.


Asunto(s)
Criptococosis , Cryptococcus gattii , Cryptococcus neoformans , Antifúngicos , Criptococosis/veterinaria , Cryptococcus gattii/genética , Cryptococcus neoformans/genética , Genotipo , Humanos , Tipificación de Secuencias Multilocus , Técnicas de Tipificación Micológica
7.
Zookeys ; 996: 93-105, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33312047

RESUMEN

Two new species of Bohayella Belokobylskij, 1987 from Costa Rica are described: Bohayella geraldinae Kang, sp. nov. and Bohayella hansoni Kang, sp. nov. These are new distribution records for the genus in the Neotropical region. In addition, a key to species of the genus Bohayella of Costa Rica is presented. The current work elevates the number of species included in Bohayella from nine to eleven.

8.
Hepatology ; 69(1): 245-257, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30063078

RESUMEN

Osteopenia and bone fractures are significant causes of morbidity in children with cholestatic liver disease. Dual-energy X-ray absorptiometry (DXA) analysis was performed in children with intrahepatic cholestatic diseases who were enrolled in the Longitudinal Study of Genetic Causes of Intrahepatic Cholestasis in the Childhood Liver Disease Research Network. DXA was performed on participants aged >5 years (with native liver) diagnosed with bile acid synthetic disorder (BASD), alpha-1 antitrypsin deficiency (A1AT), chronic intrahepatic cholestasis (CIC), and Alagille syndrome (ALGS). Weight, height, and body mass index Z scores were lowest in CIC and ALGS. Total bilirubin (TB) and serum bile acids (SBA) were highest in ALGS. Bone mineral density (BMD) and bone mineral content (BMC) Z scores were significantly lower in CIC and ALGS than in BASD and A1AT (P < 0.001). After anthropometric adjustment, bone deficits persisted in CIC but were no longer noted in ALGS. In ALGS, height-adjusted and weight-adjusted subtotal BMD and BMC Z scores were negatively correlated with TB (P < 0.001) and SBA (P = 0.02). Mean height-adjusted and weight-adjusted subtotal BMC Z scores were lower in ALGS participants with a history of bone fractures. DXA measures did not correlate significantly with biliary diversion status. Conclusion: CIC patients had significant bone deficits that persisted after adjustment for height and weight and generally did not correlate with degree of cholestasis. In ALGS, low BMD and BMC reference Z scores were explained by poor growth. Anthropometrically adjusted DXA measures in ALGS correlate with markers of cholestasis and bone fracture history. Reduced bone density in this population is multifactorial and related to growth, degree of cholestasis, fracture vulnerability, and contribution of underlying genetic etiology.


Asunto(s)
Densidad Ósea , Colestasis/etiología , Trastornos del Crecimiento/etiología , Hepatopatías/complicaciones , Hepatopatías/fisiopatología , Absorciometría de Fotón , Adolescente , Niño , Enfermedad Crónica , Correlación de Datos , Femenino , Humanos , Estudios Longitudinales , Masculino
9.
PLoS Negl Trop Dis, v. 13, n. 12, e0007935, dez. 2019
Artículo en Inglés | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-2962

RESUMEN

Objectives Although more than 1.8 million people survive snakebite envenomation each year, their recovery is understudied. Obtaining long-term follow-up is challenging in both high- and low-resource settings. The Patient-Specific Functional Scale (PSFS) is an easily administered, well-accepted patient-reported outcome that is validated for assessing limb recovery from snakebite envenomation. We studied whether the PSFS is valid and reliable when administered by telephone. Methods This is a secondary analysis of data from a randomized clinical trial. We analyzed the results of PSFS collected in-person on days 3, 7, 14, 21, and 28 and by telephone on days 10, 17, and 24. We assessed the following scale psychometric properties: (a) content validity (ceiling and floor effects), (b) internal structure and consistency (Cronbach’s alpha), and (c) temporal and external validity using Intraclass Correlation Coefficient (ICC). Temporal stability was assessed using Spearman’s correlation coefficient and agreement between adjacent in-person and telephonic assessments with Cohen’s kappa. Bland Altman analysis was used to assess differential bias in low and high score results. Results Data from 74 patients were available for analysis. Floor effects were seen in the early post-injury time points (median: 3 (IQR: 0, 5) at 3 days post-enrollment) and ceiling effects in the late time points (median: 9 (IQR: 8, 10). Internal consistency was good to excellent with both in-person (Cronbach a: 0.91 (95%CI 0.88, 0.95)) and telephone administration (0.81 (0.73, 0.89). Temporal stability was also good (ICC: 0.83 (0.72, 0.89) in-person, 0.80 (0.68, 0.88) telephone). A strong linear correlation was found between in-person and telephone administration (Spearman’s Ró: 0.83 (CI: 0.78, 0.84), consistency was assessed as excellent (Cohen’s capa 0.81 (CI: 0.78, 0.84), and Bland Altman analysis showed no systematic bias. Conclusions Telephone administration of the PSFS provides valid, reliable, and consistent data for the assessment of recovery from snakebite envenomation.

10.
Hematology Am Soc Hematol Educ Program ; 2018(1): 348-352, 2018 11 30.
Artículo en Inglés | MEDLINE | ID: mdl-30504331

RESUMEN

The direct oral anticoagulants (DOACs) have a wide therapeutic index, few drug interaction, no dietary interactions and do not require dose adjustment according to the results of routine coagulation testing. Despite these advantages over warfarin, the DOACs remain high risk medications. There is evidence that non-adherence, off-label dosing and inadequate care transitions during DOAC therapy increase the risk of bleeding and thromboembolic complications. Although DOACs are approved for a growing number of indications, there remain patient populations who are not good candidates. Existing expertise within an Anticoagulation Management Service (AMS) should be leveraged to optimize all anticoagulant therapies including the DOACs. The AMS can facilitate initial drug therapy selection and dose management, reinforce patient education and adherence as well as managing drug interactions and invasive procedures. In the event that a transition to warfarin is warranted, the AMS is already engaged which limits the risk of fragmented patient care and ensures that therapeutic anticoagulation is re-established in a timely manner. The AMS of the future will provide comprehensive management for all patients receiving anticoagulant medications and continue to provide anticoagulation expertise to the healthcare team.


Asunto(s)
Anticoagulantes/farmacocinética , Anticoagulantes/uso terapéutico , Monitoreo de Drogas/métodos , Warfarina , Administración Oral , Humanos
11.
Transl Psychiatry ; 5: e540, 2015 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-25826115

RESUMEN

Psychotic disorders such as schizophrenia are biologically complex and carry huge population morbidity due to their prevalence, persistence and associated disability. Defined by features such as delusions and hallucinations, they involve cognitive dysfunction and neurotransmitter dysregulations that appear mostly to involve the dopaminergic and glutamatergic systems. A number of genetic and environmental factors are associated with these disorders but it has been difficult to identify the biological pathways underlying the principal symptoms. The endophenotype concept of stable, heritable traits that form a mechanistic link between genes and an overt expression of the disorder has potential to reduce the complexity of psychiatric phenotypes. In this study, we used a genetically sensitive design with individuals with a first episode of psychosis, their non-affected first-degree relatives and non-related healthy controls. Metabolomic analysis was combined with neurocognitive assessment to identify multilevel endophenotypic patterns: one concerned reaction times during the performance of cognitive and emotional tests that have previously been associated with the glutamate neurotransmission system, the other involved metabolites involved directly and indirectly in the co-activation of the N-methyl-D-aspartate receptor, a major receptor of the glutamate system. These cognitive and metabolic endophenotypes may comprise a single construct, such that genetically mediated dysfunction in the glutamate system may be responsible for delays in response to cognitive and emotional functions in psychotic disorders. This focus on glutamatergic neurotransmission should guide drug discovery and experimental medicine programmes in schizophrenia and related disorders.


Asunto(s)
Endofenotipos/sangre , Aminoácidos Excitadores/sangre , Predisposición Genética a la Enfermedad/genética , Trastornos Psicóticos/sangre , Trastornos Psicóticos/genética , Transmisión Sináptica/genética , Adulto , Análisis de Varianza , Cromatografía Liquida , Femenino , Ácido Glutámico/sangre , Humanos , Espectroscopía de Resonancia Magnética , Masculino , Espectrometría de Masas , Metabolómica , Pruebas Neuropsicológicas , Análisis de Componente Principal , Trastornos Psicóticos/fisiopatología , Tiempo de Reacción , Receptores de N-Metil-D-Aspartato/sangre , Transmisión Sináptica/fisiología , Adulto Joven
13.
PLoS One ; 10(2): e0118614, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25705876

RESUMEN

Climate change can profoundly alter species' distributions due to changes in temperature, precipitation, or seasonality. Migratory monarch butterflies (Danaus plexippus) may be particularly susceptible to climate-driven changes in host plant abundance or reduced overwintering habitat. For example, climate change may significantly reduce the availability of overwintering habitat by restricting the amount of area with suitable microclimate conditions. However, potential effects of climate change on monarch northward migrations remain largely unknown, particularly with respect to their milkweed (Asclepias spp.) host plants. Given that monarchs largely depend on the genus Asclepias as larval host plants, the effects of climate change on monarch northward migrations will most likely be mediated by climate change effects on Asclepias. Here, I used MaxEnt species distribution modeling to assess potential changes in Asclepias and monarch distributions under moderate and severe climate change scenarios. First, Asclepias distributions were projected to extend northward throughout much of Canada despite considerable variability in the environmental drivers of each individual species. Second, Asclepias distributions were an important predictor of current monarch distributions, indicating that monarchs may be constrained as much by the availability of Asclepias host plants as environmental variables per se. Accordingly, modeling future distributions of monarchs, and indeed any tightly coupled plant-insect system, should incorporate the effects of climate change on host plant distributions. Finally, MaxEnt predictions of Asclepias and monarch distributions were remarkably consistent among general circulation models. Nearly all models predicted that the current monarch summer breeding range will become slightly less suitable for Asclepias and monarchs in the future. Asclepias, and consequently monarchs, should therefore undergo expanded northern range limits in summer months while encountering reduced habitat suitability throughout the northern migration.


Asunto(s)
Migración Animal/fisiología , Asclepias/parasitología , Mariposas Diurnas/fisiología , Cambio Climático , Ecosistema , Animales , Cruzamiento , América Central , Clima , Ambiente , Femenino , Geografía , Interacciones Huésped-Parásitos , Larva/fisiología , Masculino , Modelos Teóricos , América del Norte , Dinámica Poblacional , Estaciones del Año , América del Sur
14.
Am J Trop Med Hyg ; 91(1): 89-91, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24865674

RESUMEN

After 6 months of a trip to Haiti, a 25-year-old healthy man presented with a 6-week history of a very slow progressive intermittent bilateral testicular pain and swelling. The biopsies in both testicles revealed the presence of a dead filarial parasite. Polymerase chain reaction products of the DNA from the biopsy were shown to have a 100% identity to Wuchereria bancrofti. Despite being uncommon in travelers, this presentation of W. bancrofti highlights the possibility of acquiring W. bancrofti during short-term trips to highly endemic regions of the world (i.e., Haiti).


Asunto(s)
Filariasis Linfática/parasitología , Testículo/parasitología , Wuchereria bancrofti/fisiología , Adulto , Animales , Filariasis Linfática/diagnóstico , Filariasis Linfática/patología , Haití , Humanos , Masculino , Testículo/patología , Viaje , Wuchereria bancrofti/patogenicidad
15.
Int J Parasitol Parasites Wildl ; 2: 124-30, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24533325

RESUMEN

In the eastern Gulf of Mexico, off the coast of Florida, grey snapper, Lutjanus griseus was found to be infected with the myxozoan parasite Sphaerospora motemarini n. sp., with high prevalence (83%) and intensity of infection occuring in age-0 fish, and with parasite levels decreasing with age (age-1 snapper 40%; age-2 snapper 0%). The morphological, molecular and phylogenetic characterisation of the myxozoan showed that it is a member of the typically marine, polysporoplasmid Sphaerospora spp. which form a subclade within the Sphaerospora sensu stricto clade of myxozoans, which is characterised by large expansion segments in their SSU rDNA sequences. Presporogonic stages of S. motemarini n. sp. were detected in the blood, using PCR. Pseudoplasmodia and spores were found to develop in the renal corpuscles of the host, causing their massive expansion. Macroscopic and histopathological changes were observed in age-0 fish and show that S. motemarini n. sp. causes severe glomerulonephritis in L. griseus leading to a compromised host condition, which makes it more susceptible to stress (catch-and-release, predators, water quality) and can result in mortalities. These results are discussed in relation to the exploitation of grey snapper populations by commercial and recreational fisheries and with the observed increased mortalities with temperature along the coast of Florida. In the future, we would like to determine prevalence and intensity of infection with S. motemarini n. sp. in juvenile L. griseus in different areas of the Gulf of Mexico in order to be able to estimate the temperature dependence of S. motemarini n. sp. proliferation and to be able to predict its distribution and severity during climatic changes in the Gulf.

16.
J Pediatr ; 160(2): 291-6, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21911225

RESUMEN

OBJECTIVES: To describe the risk of seizures in children with acute stroke and identify factors predicting their later risk of epilepsy. STUDY DESIGN: Data for patients >3.5 years of age at a tertiary care children's hospital with acute stroke were collected and reviewed. RESULTS: Seventy-seven patients were identified (mean age, 8.4 years); 21% had clinical seizures. An additional 10% of patients had a clinical seizure during the acute hospitalization. Status epilepticus was common in infants and patients with cortical strokes. Non-convulsive status epilepticus was captured only in patients with prolonged electroencephalograms and always within 24 hours of monitoring. Six months after their stroke, 24% of our patients had epilepsy, all of whom experienced seizures at initial presentation with stroke. CONCLUSION: In our series of pediatric patients with stroke, most of the clinical seizures occurred within the first 24 hours of presentation and did not vary in stroke subtype. Status epilepticus was common, especially in infants. Epilepsy had a high likelihood of developing in the next 6 months in children with seizures in the first 24 hours of stroke onset. Prolonged electroencephalogram monitoring was useful in detecting non-convulsive status epilepticus, but not in predicting the risk of epilepsy at 6 months.


Asunto(s)
Electroencefalografía , Convulsiones/etiología , Convulsiones/fisiopatología , Accidente Cerebrovascular/complicaciones , Adolescente , Factores de Edad , Niño , Preescolar , Epilepsia/etiología , Epilepsia/fisiopatología , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Guías de Práctica Clínica como Asunto , Estudios Prospectivos , Factores de Riesgo , Convulsiones/diagnóstico , Estado Epiléptico/etiología , Estado Epiléptico/fisiopatología , Accidente Cerebrovascular/fisiopatología , Factores de Tiempo
17.
Am Nat ; 174(1): 34-45, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19438322

RESUMEN

Numerous studies of wild populations have shown that phenotypic traits can change adaptively on short timescales, but very few studies have considered coincident changes in major fitness components. We here examine adaptive changes in life-history traits and survival rates for wild guppies introduced into new environments. Female life-history traits in the derived (Damier River) populations diverged from the ancestral (Yarra River) population, as a result of adaptation to predation regime (high vs. low) and other aspects of the local river. Moreover, some components of the derived Damier populations, particularly juveniles, now show higher survival in the Damier than do contemporary representatives from the ancestral Yarra population. These results suggest that adaptive change can improve survival rates after fewer than 10 years (fewer than 30 guppy generations) in a new environment.


Asunto(s)
Ecosistema , Poecilia/fisiología , Animales , Poecilia/genética , Poecilia/crecimiento & desarrollo , Conducta Predatoria , Ríos , Trinidad y Tobago
18.
J Nat Prod ; 64(10): 1326-31, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11678660

RESUMEN

The aerial parts of Trixis pallida afforded seven known trixanolides (18-24) together with 17 new trixanolides (1-17). Their structures were determined by 1D and 2D NMR techniques, while the absolute configuration of the trixane skeleton was determined using the Mosher method and turned out to be enantiomeric to that reported using the Horeau method. This result is further discussed from the biosynthetic point of view.


Asunto(s)
Asteraceae/química , Plantas Medicinales/química , Sesquiterpenos/aislamiento & purificación , Argentina , Cromatografía Líquida de Alta Presión , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Conformación Molecular , Estructura Molecular , Sesquiterpenos/química , Espectrofotometría Infrarroja , Estereoisomerismo
19.
Fitoterapia ; 72(6): 692-4, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11543972

RESUMEN

The antibacterial activity of the hexane, ethyl acetate and methanol extracts of the flowers, leaves and stems of Gnaphalium oxyphyllum var. oxyphyllum, G. liebmannii var. monticola and G. viscosum was investigated. The hexane extracts showed in all cases the higher inhibitions, G. oxyphyllum flower extract exhibiting the wider spectrum of activity.


Asunto(s)
Antibacterianos/farmacología , Asteraceae , Bacterias/efectos de los fármacos , Extractos Vegetales/farmacología , Diterpenos/farmacología , Flavonoides/farmacología , Humanos , Pruebas de Sensibilidad Microbiana , Hojas de la Planta/química , Tallos de la Planta/química
20.
J Nat Prod ; 63(10): 1323-8, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11076545

RESUMEN

The aerial parts of an Argentinian collection of Acanthospermum hispidum afforded 26 sesquiterpene lactones, including the two guaianolides (1 and 2) having a novel oxygen bridge between C-4 and C-14, three new cis,cis-germacranolides (4, 7, and 8), and two new melampolides (25 and 26). Guaianolides 1 and 2 seem to derive biosynthetically from the germacranolide 27 having the (1)D(14, 15)D(5) conformation. The structures were elucidated using extensive spectroscopic analysis.


Asunto(s)
Ésteres/aislamiento & purificación , Furanos/aislamiento & purificación , Lactonas/aislamiento & purificación , Magnoliopsida/química , Argentina , Ésteres/química , Furanos/química , Lactonas/química , Espectroscopía de Resonancia Magnética
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