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2.
J Hosp Infect ; 114: 117-125, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33930487

RESUMEN

BACKGROUND: Healthcare workers (HCWs) are at the front line of the ongoing coronavirus 2019 (COVID-19) pandemic. Comprehensive evaluation of the seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) among HCWs in a large healthcare system could help to identify the impact of epidemiological factors and the presence of symptoms on the immune response to the infection over time. AIM: To determine the seroprevalence of SARS-CoV-2-specific antibodies among HCWs, identify associated epidemiological factors and study antibody kinetics. METHODS: A longitudinal evaluation of the seroprevalence and epidemiology of SARS-CoV-2-specific antibodies was undertaken in approximately 30,000 HCWs in the largest healthcare system in Connecticut, USA. FINDINGS: At baseline, the prevalence of SARS-CoV-2 antibody among 6863 HCWs was 6.3% [95% confidence interval (CI) 5.7-6.9%], and was highest among patient care support (16.7%), medical assistants (9.1%) and nurses (8.2%), and lower for physicians (3.8%) and advanced practice providers (4.5%). Seroprevalence was significantly higher among African Americans [odds ratio (OR) 3.26 compared with Caucasians, 95% CI 1.77-5.99], in participants with at least one symptom of COVID-19 (OR 3.00, 95% CI 1.92-4.68), and in those reporting prior quarantine (OR 3.83, 95% CI 2.57-5.70). No symptoms were reported in 24% of seropositive participants. Among the 47% of participants who returned for a follow-up serological test, the seroreversion rate was 39.5% and the seroconversion rate was 2.2%. The incidence of re-infection in the seropositive group was zero. CONCLUSION: Although there is a decline in the immunoglobulin G antibody signal over time, 60.5% of seropositive HCWs had maintained their seroconversion status after a median of 5.5 months.


Asunto(s)
Anticuerpos Antivirales/sangre , COVID-19 , SARS-CoV-2 , Adulto , COVID-19/inmunología , Connecticut/epidemiología , Femenino , Personal de Salud , Humanos , Cinética , Masculino , Persona de Mediana Edad , SARS-CoV-2/inmunología , Estudios Seroepidemiológicos
3.
Sol Phys ; 292(2): 26, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-32269392

RESUMEN

Magnetoacoustic gravity (MAG) waves have been studied for some time. In this article, we investigate the effect that a shear flow at a tangential discontinuity embedded in a gravitationally stratified and magnetised plasma has on MAG surface waves. The dispersion relation found is algebraically analogous to the relation of the non-flow cases obtained by Miles and Roberts (Solar Phys. 141, 205, 1992), except for the introduction of a Doppler-shifted frequency for the eigenvalue. This feature, however, introduces rather interesting physics, including the asymmetric presence of forward- and backward-propagating surface waves. We find that increasing the equilibrium flow speed leads to a shift in the permitted regions of propagation for surface waves. For most wave number combinations this leads to the fast mode being completely removed, as well as more limited phase speed regimes for slow-mode propagation. We also find that upon increasing the flow, the phase speeds of the backward propagating waves are increased. Eventually, at high enough flow speeds, the wave's direction of propagation is reversed and is in the positive direction. However, the phase speed of the forward-propagating wave remains mainly the same. For strong enough flows we find that the Kelvin-Helmholtz instability can also occur when the forward- and backward-propagating modes couple.

4.
J Clin Microbiol ; 48(2): 554-8, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20007387

RESUMEN

We present data on the use of the Hybrid Capture 2 (HC2) test for the detection of high-risk human papillomavirus (HR HPV) with different thresholds for positivity within a primary screening setting and as a method of triage for low-grade cytology. In the ARTISTIC population-based trial, 18,386 women were screened by cytology and for HPV. Cervical intraepithelial neoplasia lesions of grade two and higher (CIN2+ lesions) were identified for 453 women within 30 months of an abnormal baseline sample. When a relative light unit/cutoff (RLU/Co) ratio of > or = 1 was used as the threshold for considering an HC2 result positive, 15.6% of results were positive, and the proportion of CIN2+ lesions in this group was 14.7%. The relative sensitivity for CIN2+ lesion detection was 93.4%. When an RLU/Co ratio of > or = 2 was used as the threshold, there was a 2.5% reduction in positivity, with an increase in the proportion of CIN2+ lesions detected. The relative sensitivity decreased slightly, to 90.3%. Among women with low-grade cytology, HPV prevalences were 43.7% and 40.3% at RLU/Co ratios of > or = 1 and > or = 2, respectively. The proportions of CIN2+ lesions detected were 17.3% and 18.0%, with relative sensitivities of 87.7% at an RLU/Co ratio of > or = 1 and 84.2% at an RLU/Co ratio of > or = 2. At an RLU/Co ratio of > or = 1, 68.3% of HC2-positive results were confirmed by the Roche line blot assay, compared to 77.2% of those at an RLU/Co ratio of > or = 2. Fewer HC2-positive results were confirmed for 35- to 64-year-olds (50.3% at an RLU/Co ratio of > or = 1 and 63.2% at an RLU/Co ratio of > 2) than for 20- to 34-year-olds (78.7% at an RLU/Co ratio of > or = 1 and 83.7% at an RLU/Co ratio of > 2). If the HC2 test is used for routine screening as an initial test or as a method of triage for low-grade cytology, we would suggest increasing the threshold for positivity from the RLU/Co ratio of > or = 1, recommended by the manufacturer, to an RLU/Co ratio of > or = 2, since this study has shown that a beneficial balance between relative sensitivity and the proportion of CIN2+ lesions detected is achieved at this threshold.


Asunto(s)
Técnicas de Laboratorio Clínico/métodos , Técnicas de Diagnóstico Molecular/métodos , Hibridación de Ácido Nucleico , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/diagnóstico , Neoplasias del Cuello Uterino/virología , Adulto , Femenino , Humanos , Persona de Mediana Edad , Infecciones por Papillomavirus/patología , Infecciones por Papillomavirus/virología , Sensibilidad y Especificidad , Neoplasias del Cuello Uterino/patología , Adulto Joven
5.
Equine Vet J ; 41(3): 229-32, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19469226

RESUMEN

REASONS FOR PERFORMING STUDY: Radial strain in normal hooves has been found to vary with strain gauge location, limb posture and sample limb but reported magnitudes were considered to be low. More accurate measurement of radial strain may enhance the understanding of hoof function. OBJECTIVES: To explore in vitro radial hoof strain in relation other kinetic and kinematic variables that may be related. METHODS: Five normal forelimbs were removed at the proximal articular surface of the third metacarpal bone (McIII). The limbs were loaded using a modified Instron test machine. Six calibrated infrared cameras captured movement from markers on the hoof and bone fixed markers on the second and first phalanxes and McIII, whilst radial hoof strain was measured using a calibrated instrumented plug. Change in strain, joint angle and load were found at simulated walking postures and bivariate correlations were used to compare the relationships between them. RESULTS: Radial strain was moderately correlated with proximal interphalangeal joint (PIPJ) rotation (r = -0.519). Large reductions in radial strain were found in loading and midstance with 10 degrees of heel lift postures. CONCLUSIONS AND POTENTIAL RELEVANCE: PIPJ rotation has previously been linked to the magnitude of deep digital flexor tendon (DDFT) loads and it is therefore suspected that these loads may have the greatest influence on radial strain magnitudes. Further investigation of radial strain is needed to describe the patterns fully during the stance phase in vivo.


Asunto(s)
Miembro Anterior/anatomía & histología , Miembro Anterior/fisiología , Pezuñas y Garras/anatomía & histología , Pezuñas y Garras/fisiología , Caballos/fisiología , Animales , Fenómenos Biomecánicos/fisiología
6.
Br J Cancer ; 98(10): 1704-9, 2008 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-18392052

RESUMEN

Human papillomavirus (HPV) infection causes cervical cancer and premalignant dysplasia. Type-specific HPV prevalence data provide a basis for assessing the impact of HPV vaccination programmes on cervical cytology. We report high-risk HPV (HR-HPV) type-specific prevalence data in relation to cervical cytology for 24,510 women (age range: 20-64; mean age 40.2 years) recruited into the ARTISTIC trial, which is being conducted within the routine NHS Cervical Screening Programme in Greater Manchester. The most common HR-HPV types were HPV16, 18, 31, 51 and 52, which accounted for 60% of all HR-HPV types detected. There was a marked decline in the prevalence of HR-HPV infection with age, but the proportion due to each HPV type did not vary greatly with age. Multiple infections were common below the age of 30 years but less so between age 30 and 64 years. Catch-up vaccination of this sexually active cohort would be expected to reduce the number of women with moderate or worse cytology by 45%, but the number with borderline or mild cytology would fall by only 7%, giving an overall reduction of 12% in the number of women with abnormal cytology and 27% in the number with any HR-HPV infection. In the absence of broader cross-protection, the large majority of low-grade and many high-grade abnormalities may still occur in sexually active vaccinated women.


Asunto(s)
Alphapapillomavirus/aislamiento & purificación , Cuello del Útero/virología , Tamizaje Masivo , Infecciones por Papillomavirus/epidemiología , Infecciones Tumorales por Virus/epidemiología , Neoplasias del Cuello Uterino/virología , Adulto , Factores de Edad , Alphapapillomavirus/genética , Cuello del Útero/patología , Inglaterra/epidemiología , Femenino , Humanos , Tamizaje Masivo/métodos , Persona de Mediana Edad , Infecciones por Papillomavirus/complicaciones , Reacción en Cadena de la Polimerasa , Prevalencia , Infecciones Tumorales por Virus/complicaciones , Neoplasias del Cuello Uterino/epidemiología , Neoplasias del Cuello Uterino/patología , Frotis Vaginal
7.
J Chem Ecol ; 34(4): 558-74, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18317843

RESUMEN

Plants defend themselves against herbivores and pathogens with a suite of morphological, phenological, biochemical, and biotic defenses, each of which is presumably costly. The best studied are allocation costs that involve trade-offs in investment of resources to defense versus other plant functions. Decreases in growth or reproductive effort are the costs most often associated with antiherbivore defenses, but trade-offs among different defenses may also occur within a single plant species. We examined trade-offs among defenses in closely related tropical rain forest shrubs (Piper cenocladum, P. imperiale, and P. melanocladum) that possess different combinations of three types of defense: ant mutualists, secondary compounds, and leaf toughness. We also examined the effectiveness of different defenses and suites of defenses against the most abundant generalist and specialist Piper herbivores. For all species examined, leaf toughness was the most effective defense, with the toughest species, P. melanocladum, receiving the lowest incidence of total herbivory, and the least tough species, P. imperiale, receiving the highest incidence. Although variation in toughness within each species was substantial, there were no intraspecific relationships between toughness and herbivory. In other Piper studies, chemical and biotic defenses had strong intraspecific negative correlations with herbivory. A wide variety of defensive mechanisms was quantified in the three Piper species studied, ranging from low concentrations of chemical defenses in P. imperiale to a complex suite of defenses in P. cenocladum that includes ant mutualists, secondary metabolites, and moderate toughness. Ecological costs were evident for the array of defensive mechanisms within these Piper species, and the differences in defensive strategies among species may represent evolutionary trade-offs between costly defenses.


Asunto(s)
Conducta Alimentaria , Piper/fisiología , Animales , Imidas/aislamiento & purificación , Piper/química , Piper/clasificación , Especificidad de la Especie , Árboles
8.
Cytopathology ; 17(2): 65-72, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16548990

RESUMEN

OBJECTIVE: Cervical screening programmes in England and Wales were advised by the National Institute for Clinical Excellence in 2003 to adopt liquid-based cytology (LBC) in place of conventional Papanicolaou (Pap) cytology to facilitate laboratory efficiency. Pilot evaluations in England and Scotland monitored daily or weekly workloads of smear readers and concluded that LBC could increase hourly throughput rates. This study, instead, used timing surveys to determine screening rates. METHODS: Two National Health Service cytology laboratories in Manchester and Stockport were partially converted to the LBC ThinPrep process for a cervical screening trial. Three 1-week timing surveys were conducted over 7 months. The surveys covered all LBC-trained staff. The first survey in Manchester also covered staff undertaking conventional Pap screening. The smear readers used timers to record time taken for examining and reporting each slide. RESULTS: In Manchester, in the first survey, nearly 1 minute per slide was saved by the LBC method during primary microscopy. In both laboratories, the mean microscopy time for primary screening of LBC slides was reduced by almost 1 minute between the first and second surveys. There was no difference between the second and third surveys. Microscopy by cytopathologists was also 1 minute per slide quicker with LBC than conventional Pap. The LBC inadequate rates for both laboratories were <2.0%. Organizational factors impacted on the hourly LBC primary screening rates in the laboratories, the rate for Stockport being higher than the rates in the pilot evaluations. CONCLUSIONS: The timing surveys confirm that the LBC ThinPrep technology can improve laboratory efficiency. However, decision-makers should also consider the overall costs and benefits of introducing the technology in screening programmes, including the capital investment and workforce implications.


Asunto(s)
Prueba de Papanicolaou , Enfermedades del Cuello del Útero/diagnóstico , Frotis Vaginal/métodos , Eficiencia , Femenino , Humanos , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , Tiempo
9.
Nature ; 438(7064): 45-50, 2005 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-16267547

RESUMEN

The deepest space- and ground-based observations find metal-enriched galaxies at cosmic times when the Universe was less than 1 Gyr old. These stellar populations had to be preceded by the metal-free first stars, known as 'population III'. Recent cosmic microwave background polarization measurements indicate that stars started forming early--when the Universe was < or =200 Myr old. It is now thought that population III stars were significantly more massive than the present metal-rich stellar populations. Although such sources will not be individually detectable by existing or planned telescopes, they would have produced significant cosmic infrared background radiation in the near-infrared, whose fluctuations reflect the conditions in the primordial density field. Here we report a measurement of diffuse flux fluctuations after removing foreground stars and galaxies. The anisotropies exceed the instrument noise and the more local foregrounds; they can be attributed to emission from population III stars, at an era dominated by these objects.

10.
Ann N Y Acad Sci ; 1017: 66-80, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15220141

RESUMEN

We numerically investigate the migration of dust particles with initial orbits close to those of the numbered asteroids, observed trans-Neptunian objects, and comet Encke. The fraction of silicate asteroidal particles that collided with the Earth during their lifetime varied from 11% for 100 micron particles to 0.008% for 1 micron particles. Almost all asteroidal particles with diameter d >/= 4 microns collided with the Sun. For migrating asteroidal dust particles, the peaks in semimajor axis distribution at the n:(n + 1) resonances with Earth and Venus, and the gaps associated with the 1:1 resonances with these planets are more pronounced for larger particles. The probability of collisions of cometary particles with the Earth is smaller than for asteroidal particles, and this difference is greater for larger particles.

11.
Ann N Y Acad Sci ; 1017: 46-65, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15220140

RESUMEN

The orbital evolution of about 26,000 Jupiter-crossing objects and 1,500 resonant asteroids under the gravitational influence of planets was investigated. The rate of their collisions with terrestrial planets was estimated by computing the probabilities of collisions based on random-phase approximations and the orbital elements sampled with a 500 yr step. The Bulirsh-Stoer and a symplectic orbit integrator gave similar results for orbital evolution, but sometimes give different collision probabilities with the Sun. For orbits close to that of Comet 2P, the mean collision probabilities of Jupiter-crossing objects with terrestrial planets were greater by two orders of magnitude than for some other comets. For initial orbital elements close to those of Comets 2P, 10P, 44P, and 113P, a few objects (about 0.1%) entered Earth-crossing orbits with semi-major axes a < 2 AU and aphelion distances Q < 4.2 AU, and moved in such orbits for more than 1 Myr (up to tens or even hundreds of Myr). Some of them even got inner-Earth orbits (Q < 0.983 AU) and Aten orbits. A few comets achieve typical asteroidal orbits for hundreds of Myr. Most former trans-Neptunian objects that have typical near-Earth object orbits moved in such orbits for millions of years; thus, during most of this time they were extinct comet, if they did not disintegrate.

12.
Ecotoxicol Environ Saf ; 57(1): 89-99, 2004 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-14659371

RESUMEN

Pesticide-induced changes in surface migration by earthworms in grassland were investigated using trapping and the fungicide benomyl. Traps were tended daily for 15 days after spraying, resulting in 2152 earthworms, five species, and juvenile predominance which reflected species/life-stage composition in the soil. Significant increases in migration (all worms) occurred already by day 2 due to spraying, final treatment level being 2.8 x control. Life-stage composition indicated an increased juvenile proportion from 55% to 75% due to treatment. Spraying caused surfacing juveniles to increase significantly by day 2, reaching a final level 3.8 x control, whereas for mature worms a significant increase did not occur until day 4. Species rank-order was Aporrectodea longa>A. rosea>Lumbricus terrestris>A. caliginosa in control areas, but A. longa>L. terrestris>A. rosea>A. caliginosa in sprayed areas; spraying altered the rank-order such that the anecic A. longa and L. terrestris dominated, jointly increasing from 59% to 78%. At species level, L. terrestris and A. longa exhibited significant increases of 4.6 x and 3.6 x in final migration levels in treated areas, the endogeic A. rosea and A. caliginosa having trends for increase. Species-specific differences for reaction time occurred, with significantly elevated migration already by day 1 for L. terrestris, and day 2 for A. longa and A. caliginosa. For each species, juveniles consistently showed greater increases than mature worms due to spraying, significantly so for juvenile L. terrestris, A. longa, and A. caliginosa, the two anecics reaching as high as 5.3 x and 4.7 x. The response of mature worms differed: A. longa and A. rosea increased surfacing due to treatment, L. terrestris showed a delayed reaction, whereas A. caliginosa exhibited suppressed migration. Results are discussed relative to behavior, ecological category, and risk of toxic exposure.


Asunto(s)
Benomilo/toxicidad , Ecosistema , Fungicidas Industriales/toxicidad , Movimiento/efectos de los fármacos , Oligoquetos/efectos de los fármacos , Contaminantes del Suelo/toxicidad , Animales , Estadios del Ciclo de Vida , Movimiento/fisiología , Oligoquetos/clasificación , Oligoquetos/fisiología , Especificidad de la Especie
13.
Equine Vet J ; 36(8): 683-8, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15656496

RESUMEN

REASONS FOR PERFORMING STUDY: Strains during stance on the hoof wall surface have been measured by a number of authors in vitro and in vivo. Histological structure and mechanical properties vary through the wall thickness (radially); radial strain measurements may therefore aid the understanding of mechanical function of the capsule and adjacent tissues. OBJECTIVES: To develop instrumentation capable of measuring internal hoof strain, and to carry out a preliminary comparison of normal and laminitic hooves. METHODS: Six forelimbs from 4 horses, including 2 with laminitis from the same horse, were tested using an Instron test rig designed to simulate the walk at impact, midstance and breakover. Internal strains were measured at a dorsal site using strain gauges moulded into a plug made of 007 fast-set structural adhesive. In addition, kinetic and kinematic data were collected from each specimen. RESULTS: When simulating the walk, a significant (P<0.0001) increase in gradient of radial tensile strain was found in a normal hoof wall, from 5.6 +/- 73.9 microepsilon at the outer gauge to 418.5 +/- 170.6 microepsilon at the inner gauge. However, radial strains measured at the inner gauge site in limbs with laminitis were found to be significantly (P<0.0001) compressive, with values of -406.7 +/- 156.3 and -109.9 +/- 72.4 microepsilon for Specimens 1 and 2, respectively. CONCLUSIONS AND POTENTIAL RELEVANCE: These preliminary data indicate that a marked redistribution may well occur in the wall of laminitic hooves. With a larger sample size, the results should have relevance to the treatment and management of laminitis.


Asunto(s)
Enfermedades del Pie/veterinaria , Pezuñas y Garras/fisiología , Enfermedades de los Caballos/fisiopatología , Caballos/fisiología , Cojera Animal/fisiopatología , Animales , Fenómenos Biomecánicos , Enfermedades del Pie/fisiopatología , Miembro Anterior/fisiología , Técnicas In Vitro , Presión , Zapatos , Estrés Mecánico
14.
Chemosphere ; 47(5): 547-54, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-11996130

RESUMEN

Groundwater is a complex mixture of chemicals that is naturally variable. Current legislation in the UK requires that groundwater quality and the degree of contamination are assessed using chemical methods. Such methods do not consider the synergistic or antagonistic interactions that may affect the bioavailability and toxicity of pollutants in the environment. Bioassays are a method for assessing the toxic impact of whole groundwater samples on the environment. Three rapid bioassays, Eclox, Microtox and ToxAlert, and a Daphnia magna 48-h immobilisation test were used to assess groundwater quality from sites with a wide range of historical uses. Eclox responses indicated that the test was very sensitive to changes in groundwater chemistry; 77% of the results had a percentage inhibition greater than 90%. ToxAlert, although suitable for monitoring changes in water quality under laboratory conditions, produced highly variable results due to fluctuations in temperature and the chemical composition of the samples. Microtox produced replicable results that correlated with those from D. magna tests.


Asunto(s)
Bioensayo/métodos , Daphnia/efectos de los fármacos , Agua Dulce/química , Contaminantes Químicos del Agua/toxicidad , Abastecimiento de Agua/análisis , Amoníaco/toxicidad , Animales , Cloruros/toxicidad , Urbanización , Contaminantes Químicos del Agua/análisis
15.
Dev Biol ; 233(1): 95-108, 2001 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-11319860

RESUMEN

The prostate undergoes branching morphogenesis dependent on paracrine interactions between the prostatic epithelium and the urogenital mesenchyme. To identify cell-surface molecules that function in this process, monoclonal antibodies raised against epithelial cell-surface antigens were screened for antigen expression in the developing prostate and for their ability to alter development of prostates grown in serum-free organ culture. One antibody defined a unique expression pattern in the developing prostate and inhibited growth and ductal branching of cultured prostates by inhibiting epithelial cell proliferation. Expression cloning showed that this antibody binds fucosyltransferase1, an alpha-(1,2)-fucosyltransferase that synthesizes H-type structures on the complex carbohydrate modifications of some proteins and lipids. The lectin UEA I that binds H-type 2 carbohydrates also inhibited development of cultured prostates. These data demonstrate a previously unrecognized role for fucosyltransferase1 and H-type carbohydrates in controlling the spatial distribution of epithelial cell proliferation during prostatic branching morphogenesis. We also show that fucosyltransferase1 is expressed by epithelial cells derived from benign prostatic hyperplasia or prostate cancer; thus, fucosyltransferase1 may also contribute to pathological prostatic growth. These data further suggest that rare individuals who lack fucosyltransferase1 (Bombay phenotype) should be investigated for altered reproductive function and/or altered susceptibility to benign prostatic hyperplasia and prostate cancer.


Asunto(s)
Antígenos de Diferenciación/metabolismo , Células Epiteliales/citología , Fucosiltransferasas/metabolismo , Lectinas de Plantas , Próstata/crecimiento & desarrollo , Andrógenos , Animales , Animales Recién Nacidos , Anticuerpos Monoclonales , Secuencia de Bases , División Celular , Línea Celular , Fucosiltransferasas/genética , Fucosiltransferasas/inmunología , Humanos , Lectinas , Masculino , Datos de Secuencia Molecular , Morfogénesis , Técnicas de Cultivo de Órganos , Comunicación Paracrina , Próstata/citología , ARN Mensajero/aislamiento & purificación , Ratas , Ratas Sprague-Dawley , Galactósido 2-alfa-L-Fucosiltransferasa
16.
J Comp Psychol ; 115(4): 351-64, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11824898

RESUMEN

During their 3rd week of life, 73 Octopus bimaculoides were observed to test whether discrete behaviors could be grouped reliably to reflect dimensions of temperament. Frequencies of behaviors during Week 3 were subjected to principal-components analysis (PCA), resulting in 4 components (active engagement, arousal/readiness, aggression, and avoidance/disinterest) that explain 53% of the variance. Levels of temperamental traits were then evaluated for 37 octopuses using composite scores at 3 time points across the first 9 weeks of life. Profile analysis revealed significant change for the testing group as a whole in trait expression levels from Week 3 to Week 6. Results also suggest a significant effect of relatedness on developing temperamental profiles of octopuses. Discussion focuses on how results apply to the life history of O. bimaculoides and what temperament can reveal about adaptive individuality in a protostome.


Asunto(s)
Octopodiformes/crecimiento & desarrollo , Temperamento , Factores de Edad , Agresión/psicología , Animales , Nivel de Alerta , Atención , Reacción de Prevención , Femenino , Individualidad , Masculino , Modelos Psicológicos
17.
Ultrasound Obstet Gynecol ; 16(2): 123-7, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11117080

RESUMEN

OBJECTIVES: To prospectively and quantitatively grade intracardiac echogenic focus/foci (ICEF) using sonographic gain reduction and to determine the association of ICEF by grade with fetal aneuploidy. METHODS: Women referred for raised maternal age (> or = 35 years), or > 18 years of age and with a Down syndrome risk > or = 1/270, increased trisomy 18 risk by second trimester serum screen or a prior aneuploid offspring were included in this institutionally approved protocol. Only pregnancies of gestational age between 14 and 24 weeks were included. All women had a targeted ultrasound and were offered fetal chromosome analysis. The classification of ICEF was made from a four-chamber view of the fetal heart. The echo amplitude of the ICEF was compared to that of the thoracic spine and categorized according to the comparative gain setting at which the image of the relevant structure disappeared: Grade O = no ICEF present, Grade 1 = ICEF image lost before thoracic spine when gain was reduced, Grade 2 = ICEF image lost at same gain setting as thoracic spine, Grade 3 = thoracic spine image lost before ICEF. The primary outcome was a prenatally or post-natally detected chromosomal abnormality. RESULTS: A total of 885 eligible women were examined during the 21-month study period. ICEF were seen in 29 (3.3%) fetuses: 24(83%) in the left ventricle and five (17%) in the right ventricle. A chromosome abnormality was identified in 13/671 (1.9%) fetuses without ICEF (Grade 0) and 0/21 (0%) fetuses with Grade 1 ICEF. In contrast, two of five (40%) fetuses with Grade 2 ICEF were aneuploid (P = 0.005). No Grade 3 ICEF were observed. Additional sonographic abnormalities were seen in both aneuploid fetuses with Grade 2 ICEF. Interobserver agreement on ICEF grading was noted in 50/50 (100%) examinations (kappa = 1.0). CONCLUSIONS: Sonographic grading of ICEF is feasible and highly reliable. Grade 2 ICEF, especially when accompanied by additional sonographic markers of a chromosomal abnormality, are associated with aneuploidy significantly more frequently than Grade 1 ICEF.


Asunto(s)
Aneuploidia , Síndrome de Down/diagnóstico por imagen , Corazón Fetal/diagnóstico por imagen , Embarazo de Alto Riesgo , Ultrasonografía Prenatal/métodos , Adulto , Estudios de Factibilidad , Femenino , Edad Gestacional , Humanos , Tamizaje Masivo/métodos , Edad Materna , Persona de Mediana Edad , Músculos Papilares/diagnóstico por imagen , Embarazo , Estudios Prospectivos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Índice de Severidad de la Enfermedad
19.
Anticancer Drugs ; 11(7): 591-601, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11036964

RESUMEN

Randomized trials comparing the aromatase inhibitors, anastrozole and letrozole, to megestrol acetate (MA) in postmenopausal women with advanced breast cancer demonstrated that both agents are better tolerated than MA with comparable efficacy. In addition, one trial revealed that tumor response and time to treatment failure were significantly better with letrozole. Since oncologists are faced with a choice between three agents with at least comparable efficacy but different toxicity profiles and cost, a cost-utility analysis was conducted to quantify these differences and to determine if the new agents are more cost-effective than MA. In the absence of a randomized three-arm trial, a decision model was developed to simulate the most common therapeutic outcomes. The clinical data were obtained from an overview analysis of randomized trials. Total hospital resource consumption was collected from 87 patients with advanced disease that had failed second-line hormonal therapy. Utility estimates were obtained from interviewing a random sample of 25 women from the general public and 25 female health care professionals using the Time Trade-Off technique. The model suggested a similar duration of quality-adjusted progression-free survival between drugs (letrozole 150 days, anastrozole 153 days and MA 146 days). Letrozole had an overall cost of Can$2949 per patient which was comparable to MA at Can$2966 per patient. In contrast, anastrozole was slightly more costly than MA at $Can3149 per patient, respectively. The analysis revealed that letrozole has comparable overall costs relative to MA while providing at least equivalent quality-adjusted progression-free survival. These outcomes were largely related to its higher tumor response rate, which translated to a lower proportion of patients requiring chemotherapy. Anastrozole was slightly more costly than MA and did not demonstrate superiority in quality-adjusted progression-free survival in this palliative setting.


Asunto(s)
Antineoplásicos/uso terapéutico , Inhibidores de la Aromatasa , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/economía , Técnicas de Apoyo para la Decisión , Acetato de Megestrol/uso terapéutico , Nitrilos/uso terapéutico , Triazoles/uso terapéutico , Anastrozol , Canadá , Costos y Análisis de Costo , Femenino , Humanos , Letrozol , Calidad de Vida , Ensayos Clínicos Controlados Aleatorios como Asunto
20.
J Ultrasound Med ; 19(10): 689-94, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11026581

RESUMEN

We sought to assess prospectively the efficacy of community-based genetic ultrasonography in detecting chromosomally abnormal fetuses in a high-risk population and determine independent markers of aneuploidy. Patients 18 years old and older who were between 14 and 24 weeks' gestation were included if referred for maternal age greater than 35 years, increased risk of Down syndrome or trisomy 18 by second trimester serum screen, or prior affected offspring. All women had a targeted ultrasonographic examination between April 1997 and June 1999 and were offered fetal chromosomal analysis. Markers of aneuploidy and pregnancy outcomes were recorded prospectively. The primary outcome was prenatally or postnatally detected chromosomal abnormalities. Of the 1030 fetuses seen during the study, 789 had outcome data available and constituted the study group. In this group, 694 (87.9%) ultrasonograms were normal, 73 (9.2%) had one marker present, 17 (2.2%) had two markers present, and 5 (0.6%) had three or more markers present. Fourteen of 17 (82.3%) aneuploid fetuses had an abnormal ultrasonogram (one or more markers present), including 5 of 7 (71.4%) with Down syndrome. Logistic regression showed abnormal four-chamber view, structural anomaly, and intracardiac echogenic focus to be significant aneuploidy markers. The amniocentesis rate was 334 of 1030 (32.4%), and it increased with the number of sonographic markers noted (0 = 29.9%, 1 = 60.2%, 2 = 70.6%, 3 or more = 80%). Genetic ultrasonography is highly effective in identifying chromosomally abnormal fetuses in a community-based practice.


Asunto(s)
Amniocentesis , Aberraciones Cromosómicas/diagnóstico por imagen , Aberraciones Cromosómicas/embriología , Ultrasonografía Prenatal , Adolescente , Adulto , Aneuploidia , Aberraciones Cromosómicas/genética , Trastornos de los Cromosomas , Servicios de Salud Comunitaria , Síndrome de Down/diagnóstico , Femenino , Humanos , Embarazo , Segundo Trimestre del Embarazo , Estudios Prospectivos
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