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1.
J Dairy Sci ; 105(4): 3615-3632, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35181140

RESUMEN

Accurate and timely pregnancy diagnosis is an important component of effective herd management in dairy cattle. Predicting pregnancy from Fourier-transform mid-infrared (FT-MIR) spectroscopy data is of particular interest because the data are often already available from routine milk testing. The purpose of this study was to evaluate how well pregnancy status could be predicted in a large data set of 1,161,436 FT-MIR milk spectra records from 863,982 mixed-breed pasture-based New Zealand dairy cattle managed within seasonal calving systems. Three strategies were assessed for defining the nonpregnant cows when partitioning the records according to pregnancy status in the training population. Two of these used records for cows with a subsequent calving only, whereas the third also included records for cows without a subsequent calving. For each partitioning strategy, partial least squares discriminant analysis models were developed, whereby spectra from all the cows in 80% of herds were used to train the models, and predictions on cows in the remaining herds were used for validation. A separate data set was also used as a secondary validation, whereby pregnancy diagnosis had been assigned according to the presence of pregnancy-associated glycoproteins (PAG) in the milk samples. We examined different ways of accounting for stage of lactation in the prediction models, either by including it as an effect in the prediction model, or by pre-adjusting spectra before fitting the model. For a subset of strategies, we also assessed prediction accuracies from deep learning approaches, utilizing either the raw spectra or images of spectra. Across all strategies, prediction accuracies were highest for models using the unadjusted spectra as model predictors. Strategies for cows with a subsequent calving performed well in herd-independent validation with sensitivities above 0.79, specificities above 0.91 and area under the receiver operating characteristic curve (AUC) values over 0.91. However, for these strategies, the specificity to predict nonpregnant cows in the external PAG data set was poor (0.002-0.04). The best performing models were those that included records for cows without a subsequent calving, and used unadjusted spectra and days in milk as predictors, with consistent results observed across the training, herd-independent validation and PAG data sets. For the partial least squares discriminant analysis model, sensitivity was 0.71, specificity was 0.54 and AUC values were 0.68 in the PAG data set; and for an image-based deep learning model, the sensitivity was 0.74, specificity was 0.52 and the AUC value was 0.69. Our results demonstrate that in pasture-based seasonal calving herds, confounding between pregnancy status and spectral changes associated with stage of lactation can inflate prediction accuracies. When the effect of this confounding was reduced, prediction accuracies were not sufficiently high enough to use as a sole indicator of pregnancy status.


Asunto(s)
Lactancia , Leche , Animales , Bovinos , Femenino , Análisis de los Mínimos Cuadrados , Leche/química , Nueva Zelanda , Embarazo , Espectrofotometría Infrarroja/veterinaria
2.
J Dairy Sci ; 102(7): 6357-6372, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31030929

RESUMEN

The use of Fourier-transform mid-infrared (FTIR) spectroscopy is of interest to the dairy industry worldwide for predicting milk composition and other novel traits that are difficult or expensive to measure directly. Although there are many valuable applications for FTIR spectra, noise from differences in spectral responses between instruments is problematic because it reduces prediction accuracy if ignored. The purpose of this study was to develop strategies to reduce the impact of noise and to compare methods for standardizing FTIR spectra in order to reduce between-instrument variability in multiple-instrument networks. Noise levels in bands of the infrared spectrum caused by the water content of milk were characterized, and a method for identifying and removing outliers was developed. Two standardization methods were assessed and compared: piecewise direct standardization (PDS), which related spectra on a primary instrument to spectra on 5 other (secondary) instruments using identical milk-based reference samples (n = 918) analyzed across the 6 instruments; and retroactive percentile standardization (RPS), whereby percentiles of observed spectra from routine milk test samples (n = 2,044,094) were used to map and exploit primary- and secondary-instrument relationships. Different applications of each method were studied to determine the optimal way to implement each method across time. Industry-standard predictions of milk components from 2,044,094 spectra records were regressed against predictions from spectra before and after standardization using PDS or RPS. The PDS approach resulted in an overall decrease in root mean square error between industry-standard predictions and predictions from spectra from 0.190 to 0.071 g/100 mL for fat, from 0.129 to 0.055 g/100 mL for protein, and from 0.143 to 0.088 g/100 mL for lactose. Reductions in prediction error for RPS were similar but less consistent than those for PDS across time, but similar reductions were achieved when PDS coefficients were updated monthly and separate primary instruments were assigned for the North and South Islands of New Zealand. We demonstrated that the PDS approach is the most consistent method to reduce prediction errors across time. We also showed that the RPS approach is sensitive to shifts in milk composition but can be used to reduce prediction errors, provided that secondary-instrument spectra are standardized to a primary instrument with samples of broadly equivalent milk composition. Appropriate implementation of either of these approaches will improve the quality of predictions based on FTIR spectra for various downstream applications.


Asunto(s)
Bovinos/metabolismo , Leche/química , Espectroscopía Infrarroja por Transformada de Fourier/normas , Animales , Industria Lechera , Leche/metabolismo , Nueva Zelanda , Fenotipo , Estándares de Referencia , Espectroscopía Infrarroja por Transformada de Fourier/instrumentación , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Espectroscopía Infrarroja por Transformada de Fourier/veterinaria
3.
J Dairy Sci ; 101(5): 4650-4659, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29454693

RESUMEN

The genetic merit of a herd is a key determinant in productivity for dairy farmers. However, making breeding decisions to maximize the rate of genetic gain can be complex because there is no certainty about which cows will become pregnant with a heifer calf. In this study, breeding worth (BrW) was used as a measure of genetic merit, and several mating strategies were evaluated. These strategies included randomly mating whole herds to the entire bull team, excluding low-ranked cows from producing replacement heifers, and nominating high-ranked cows to the most highly ranked bulls. Simulations were undertaken using 4 bull teams generated from bulls currently marketed in New Zealand and a selection of New Zealand dairy herds. Average replacement heifer BrW was calculated for 1,000 iterations of each combination of mating strategy, herd, and bull team (scenario). Variation in resulting average replacement heifer BrW within scenarios was due to random sampling of which cows became pregnant with a heifer calf. Relative to mating the whole herd to an entire bull team, excluding the lowest ranked cows from producing replacements resulted in the greatest increase in average replacement heifer BrW across all herds and bull teams, with a gain of approximately 0.4 BrW point for each 1% of cows excluded. Nominating top-ranking cows to the highest ranking bulls in the team had little effect (0.06-0.13 BrW increase for each 1% of top cows nominated) in improving BrW of replacement heifers. The number of top bulls nominated had a variable effect depending on the BrW spread of the entire bull team. Although excluding cows with the lowest BrW from producing replacement heifers is most effective for improving BrW, it is important to ensure that the number of heifers born is sufficient to replace cows leaving the herd. It is likely that optimal strategies for improving BrW will vary from farm to farm depending not only on the BrW structure of the herd, the bull team available, and the reproduction success on farm but also on farm management practices. This simulation study provides expected outcomes from a variety of mating strategies to allow informed decision making on farm.


Asunto(s)
Cruzamiento/métodos , Bovinos/fisiología , Animales , Bovinos/genética , Industria Lechera , Femenino , Masculino , Nueva Zelanda , Parto , Embarazo , Reproducción
4.
J Dairy Sci ; 100(7): 5491-5500, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28477999

RESUMEN

X chromosome inactivation (XCI) is a process by which 1 of the 2 copies of the X chromosomes present in female mammals is inactivated. The transcriptional silencing of one X chromosome achieves dosage compensation between XX females and XY males and ensures equal expression of X-linked genes in both sexes. Although all mammals use this form of dosage compensation, the complex mechanisms that regulate XCI vary between species, tissues, and development. These mechanisms include not only varying levels of inactivation, but also the nature of inactivation, which can range from being random in nature to driven by parent of origin. To date, no data describing XCI in calves or adult cattle have been reported and we are reliant on data from mice to infer potential mechanisms and timings for this process. In the context of dairy cattle breeding and genomic prediction, the implications of X chromosome inheritance and XCI in the mammary gland are particularly important where a relatively small number of bulls pass their single X chromosome on to all of their daughters. We describe here the use of RNA-seq, whole genome sequencing and Illumina BovineHD BeadChip (Illumina, San Diego, CA) genotypes to assess XCI in lactating mammary glands of dairy cattle. At a population level, maternally and paternally inherited copies of the X chromosome are expressed equally in the lactating mammary gland consistent with random inactivation of the X chromosome. However, average expression of the paternal chromosome ranged from 10 to 90% depending on the individual animal. These results suggest that either the mammary gland arises from 1 or 2 stem cells, or a nongenetic mechanism that skews XCI exists. Although a considerable amount of future work is required to fully understand XCI in cattle, the data reported here represent an initial step in ensuring that X chromosome variation is captured and used in an appropriate manner for future genomic selection.


Asunto(s)
Regulación de la Expresión Génica , Glándulas Mamarias Animales , Inactivación del Cromosoma X , Animales , Bovinos , Compensación de Dosificación (Genética) , Femenino , Lactancia , Masculino , Factores Sexuales , Cromosoma X/genética
5.
Allergy ; 70(9): 1039-51, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25808296

RESUMEN

Precautionary allergen labelling (PAL) was introduced by the food industry to help manage and communicate the possibility of reaction from the unintended presence of allergens in foods. However, in its current form, PAL is counterproductive for consumers with food allergies. This review aims to summarize the perspectives of all the key stakeholders (including clinicians, patients, food industry and regulators), with the aim of defining common health protection and risk minimization goals. The lack of agreed reference doses has resulted in inconsistent application of PAL by the food industry and in levels of contamination that prompt withdrawal action by enforcement officers. So there is a poor relationship between the presence or absence of PAL and actual reaction risk. This has led to a loss of trust in PAL, reducing the ability of consumers with food allergies to make informed choices. The result has been reduced avoidance, reduced quality of life and increased risk-taking by consumers who often ignore PAL. All contributing stakeholders agree that PAL must reflect actual risk. PAL should be transparent and consistent with rules underpinning decision-making process being communicated clearly to all stakeholders. The use of PAL should indicate the possible, unintended presence of an allergen in a consumed portion of a food product at or above any proposed action level. This will require combined work by all stakeholders to ensure everyone understands the approach and its limitations. Consumers with food allergy then need to be educated to undertake individualized risk assessments in relation to any PAL present.


Asunto(s)
Alérgenos , Etiquetado de Alimentos/normas , Hipersensibilidad a los Alimentos/prevención & control , Industria de Alimentos , Personal de Salud , Humanos , Medición de Riesgo
6.
BJOG ; 118(5): 624-8, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21392225

RESUMEN

Sildenafil citrate therapy for severe early-onset intrauterine growth restriction. BJOG 2011;118:624-628. Currently, there is no effective therapy for severe early-onset intrauterine growth restriction (IUGR). Sildenafil citrate vasodilates the myometrial arteries isolated from women with IUGR-complicated pregnancies. Women were offered Sildenafil (25 mg three times daily until delivery) if their pregnancy was complicated by early-onset IUGR [abdominal circumference (AC)< 5th percentile] and either the gestational age was <25(+0) weeks or an estimate of the fetal weight was <600 g (excluding known fetal anomaly/syndrome and/or planned termination). Sildenafil treatment was associated with increased fetal AC growth [odds ratio, 12.9; 95% confidence interval (CI), 1.3, 126; compared with institutional Sildenafil-naive early-onset IUGR controls]. Randomised controlled trial data are required to determine whether Sildenafil improves perinatal outcomes for early-onset IUGR-complicated pregnancies.


Asunto(s)
Retardo del Crecimiento Fetal/tratamiento farmacológico , Piperazinas/uso terapéutico , Sulfonas/uso terapéutico , Vasodilatadores/uso terapéutico , Adulto , Velocidad del Flujo Sanguíneo/efectos de los fármacos , Estudios de Casos y Controles , Femenino , Retardo del Crecimiento Fetal/mortalidad , Retardo del Crecimiento Fetal/fisiopatología , Humanos , Recién Nacido , Mortalidad Perinatal , Placenta/irrigación sanguínea , Embarazo , Resultado del Embarazo , Purinas/uso terapéutico , Citrato de Sildenafil , Útero/irrigación sanguínea
7.
Early Hum Dev ; 84(4): 237-42, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17662542

RESUMEN

BACKGROUND: More mothers are choosing to return to work during the first 2 years of their child's life with an uncertain impact on early developmental outcomes. AIMS: To determine the association between duration of maternity leave and motor and social development of toddlers. STUDY DESIGN: Population-based, retrospective cohort study. SUBJECTS: The Canadian National Longitudinal Survey on Children and Youth (NLSCY) Cycle 3 provides data on the characteristics and life experience of Canadian children. For sampled households, the person most knowledgeable about the child completed a survey on demographics, parent characteristics and family environment. The analysis was limited to 6664 families with children up to 2 years. OUTCOME MEASURES: Logistic regression was used to assess the association between duration of maternity leave and impaired performance (<-1 SD below the mean) on the Motor and Social Development (MSD) scale adjusted for multiple covariates including maternal age, gender, breastfeeding and socioeconomic status. RESULTS: One month of maternity leave increased the odds of impaired performance on the MSD by 3% (OR 1.03, 95% CI 1.02, 1.04). This was also seen with categorized maternity leave duration. Being male (OR 1.53, 95% CI 1.35, 1.74) and having a younger mother (OR 1.48, 95% CI 0.98, 2.23) increased the risk of impaired performance on the MSD while being of higher SES reduced the risk (OR 0.96, 95% CI 0.93, 1.00). CONCLUSIONS: There is an association between duration of maternity leave and impaired performance in motor and social development in children up to 2 years.


Asunto(s)
Desarrollo Infantil/fisiología , Madres/estadística & datos numéricos , Destreza Motora/fisiología , Conducta Social , Mujeres Trabajadoras/estadística & datos numéricos , Adolescente , Adulto , Canadá , Preescolar , Estudios Transversales , Femenino , Humanos , Lactante , Recién Nacido , Estudios Longitudinales , Masculino , Madres/psicología , Permiso Parental/estadística & datos numéricos , Estudios Retrospectivos , Mujeres Trabajadoras/psicología
8.
J Dairy Sci ; 91(12): 4560-70, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19038931

RESUMEN

This study explored the potential value of in-line composite somatic cell count (ISCC) sensing as a sole criterion or in combination with quarter-based electrical conductivity (EC) of milk, for automatic detection of clinical mastitis (CM) during automatic milking. Data generated from a New Zealand research herd of about 200 cows milked by 2 automatic milking systems during the 2006-2007 milking season included EC, ISCC, monthly laboratory-determined SCC, and observed cases of CM that were treated with antibiotics. Milk samples for ISCC and laboratory-determined SCC were taken sequentially at the end of a cow milking. Both samples were derived from a composite cow milking obtained from the bottom of the milk receiver. Different time windows were defined in which true-positive, false-negative, and false-positive alerts were determined. Quarters suspected of having CM were visually checked and, if CM was confirmed, sampled for bacteriological culturing and treated with an antibiotic treatment. These treated quarters were considered as gold-standard positives for comparing CM detection models. Alert thresholds were adjusted to achieve a sensitivity of 80% in 3 detection models: using ISCC alone, EC alone, or a combination of these. The success rate (also known as the positive predictive value) and the false alert rate (number of false-positive alerts per 1,000 cow milkings) were used to evaluate detection performance. Normalized ISCC estimates were highly correlated with normalized laboratory-determined SCC measurements (r = 0.82) for SCC measurements >200 x 10(3) cells/mL. Using EC alone as a detection tool resulted in a range of 6.9 to 11.0% for success rate, and a range of 4.7 to 7.8 for the false alert rate. Values for the ISCC model were better than the model using EC alone with 12.7 to 15.6% for the success rate and 2.9 to 3.7 for the false alert rate. Combining sensor information to detect CM, by using a fuzzy logic algorithm, produced a 2- to 3-fold increase in the success rate (range 21.9 to 32.0%) and a 2- to 3-fold decrease in the false alert rate (range 1.2 to 2.1) compared with the models using ISCC or EC alone. Results suggest that the performance of a CM detection system improved when ISCC information was added to a detection model using EC information.


Asunto(s)
Industria Lechera/métodos , Mastitis Bovina/diagnóstico , Leche/citología , Reconocimiento de Normas Patrones Automatizadas/métodos , Animales , Bovinos , Recuento de Células , Femenino
9.
Mar Biol ; 164(1): 20, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28042175

RESUMEN

Bathochordaeus mcnutti sp. nov. is described from the mesopelagic northeast Pacific Ocean (Monterey Bay, California, USA). Larvaceans in the genus Bathochordaeus are large, often abundant zooplankters found throughout much of the world ocean, but until recently it was unclear whether more than a single species of Bathochordaeus existed. Using remotely operated vehicles, we have made hundreds of in situ observations, compiled two decades of time-series data, and carefully collected enough specimens to determine that three species of Bathochordaeus occur in Monterey Bay: B. charon (Chun), B. stygius (Garstang), and B. mcnutti sp. nov. Bathochordaeus mcnutti is readily distinguished from its two congeners by the distinct blue outline visible around the periphery of its tail, and by other aspects of its morphology, ecology, and genetics. The abundance of larvaceans means they are ecologically important as particle processors. Species within the genus, Bathochordaeus, comprise the largest of described larvaceans.

10.
J Perinatol ; 37(2): 188-193, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27763630

RESUMEN

OBJECTIVE: To determine the effect of concomitant administration of prophylactic indomethacin and early enteral feeds on the risk of spontaneous intestinal perforation (SIP) in extremely low-birth-weight (ELBW) infants, and to describe the variation in prophylactic indomethacin use in Canada. STUDY DESIGN: A retrospective cohort study of 4268 ELBW infants born at <30 weeks' gestation admitted to Canadian neonatal units between 2010 and 2014 was conducted. Prophylactic indomethacin (I+ or I-, administered within 24 h) and early feeding (E+ or E-, initiated in the first 2 days) exposures were studied concurrently and independently. The primary outcomes were SIP and death before discharge. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated. RESULTS: Compared with the I-/E+ reference group (n=1829), infants in I+/E+ (n=285; aOR 2.92, 95% CI 1.41 to 6.08) and I+/E- (n=213; aOR 2.84, 95% CI 1.35 to 5.98) groups had higher odds of SIP, whereas those in the I-/E- group had similar odds (n=1941; aOR 1.37, 95% CI 0.88 to 2.14). Odds of SIP were higher in the indomethacin exposed group (I+) compared with the unexposed (I-) group when controlled for early feeding (aOR 2.43, 95% CI 1.41 to 4.19), but not in the early feeding group when controlled for indomethacin. The use of prophylactic indomethacin ranged from 0% usage in 13 sites to 78% use in one site. CONCLUSION: Prophylactic indomethacin was associated with increased odds of SIP independently from early feeding in this cohort; however, early enteral feeding was not associated with SIP. Marked variation in the use of prophylactic indomethacin was identified.


Asunto(s)
Hemorragia Cerebral Intraventricular/epidemiología , Nutrición Enteral , Indometacina/administración & dosificación , Recien Nacido con Peso al Nacer Extremadamente Bajo , Perforación Intestinal/epidemiología , Canadá/epidemiología , Hemorragia Cerebral Intraventricular/prevención & control , Bases de Datos Factuales , Femenino , Edad Gestacional , Humanos , Indometacina/efectos adversos , Recien Nacido Extremadamente Prematuro , Recién Nacido , Masculino , Alta del Paciente/estadística & datos numéricos , Estudios Retrospectivos , Resultado del Tratamiento
11.
Chem Biol ; 6(3): 133-41, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10074468

RESUMEN

INTRODUCTION: Ras is one of the major oncogenes. In order to function properly it has to undergo post-translational processing at its carboxyl terminus. It has been shown that inhibitors of farnesyl transferase, the first enzyme in the processing chain, can suppress the transforming activity of oncogenic Ras. RESULTS: We have identified molecular forceps, branched peptidic molecules, from combinatorial libraries that bind to the carboxyl terminus of Ras and interfere with its farnesylation without inhibiting the farnesyl transferase. The active molecules were selected by a screening against the carboxy-terminal octapeptide of Ras. CONCLUSIONS: The implications of our findings are twofold. First, we demonstrate that it is possible to prevent enzymatic transformations by blocking the enzyme's access to its substrate using a synthetic small molecule to mask the substrate. Second, we show that it is feasible to derive molecules from combinatorial libraries that bind a specific epitope on a protein by selecting these molecules with the isolated peptide epitope.


Asunto(s)
Transferasas Alquil y Aril/antagonistas & inhibidores , Genes ras/genética , Proteínas ras/metabolismo , Transferasas Alquil y Aril/metabolismo , Secuencia de Aminoácidos , Epítopos/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Fluoresceína , Biblioteca de Genes , Histamina/metabolismo , Datos de Secuencia Molecular , Proteínas de Fusión Oncogénica/química , Proteínas de Fusión Oncogénica/genética
12.
Early Hum Dev ; 81(11): 909-16, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16126353

RESUMEN

BACKGROUND: Major grades of intraventricular haemorrhage (IVH) are associated with adverse neurodevelopmental sequelae in early childhood but the extent of problems in specific cognitive areas, such as executive function, and the contribution of lesser grades of IVH to neurodevelopmental problems at school age are not well described. AIMS: To determine the neuromotor, cognitive and educational outcome of extremely low birthweight (ELBW, birthweight <1000 g) or very preterm (<28 weeks) infants at 8 years of age related to the severity of IVH diagnosed in the newborn period. DESIGN: Regional cohort study. PATIENTS: Consecutive surviving children of either birthweight <1000 g or gestational age <28 weeks born in the state of Victoria in 1991 or 1992. MAIN OUTCOME MEASURES: Neurological impairments and disabilities, cognitive function and academic progress. RESULTS: Of 298 consecutive ELBW/very preterm survivors 270 (90.6%) with cranial ultrasound data were assessed at 8 years of age. Cerebral palsy, poor motor performance and major neurosensory disability were more prevalent with increasing severity of IVH. Cognitive functioning across domains was worse with increasing severity of IVH. Most of the differences were attributable to the few (n=6) survivors who had grade 4 IVH; there were few substantial differences between survivors with lesser grades of IVH. CONCLUSIONS: Neurodevelopmental dysfunction at school age in ELBW/very preterm survivors varies little with increasing severity of IVH, with the exception of grade 4 IVH.


Asunto(s)
Retardo del Crecimiento Fetal/fisiopatología , Recién Nacido de muy Bajo Peso , Hemorragias Intracraneales/fisiopatología , Enfermedades del Sistema Nervioso/epidemiología , Niño , Preescolar , Trastornos del Conocimiento/epidemiología , Trastornos del Conocimiento/fisiopatología , Escolaridad , Humanos , Recién Nacido , Enfermedades del Sistema Nervioso/fisiopatología
13.
Am J Surg Pathol ; 17(10): 1062-6, 1993 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8372944

RESUMEN

An aneurysmal bone cyst-like reaction involving the left common carotid artery bifurcation in an otherwise healthy 7-year-old boy is described. The patient presented with a 6-week history of an enlarging pulsatile neck mass. The mass was excised with connection of arteries on either side with a saphenous vein graft. There were no associated intracranial arterial aneurysms or associated skeletal lesions. A history of trauma could not be elicited. To the best of our knowledge this is the first report of an aneurysmal cyst, bone type, involving a large blood vessel.


Asunto(s)
Aneurisma/patología , Quistes Óseos/patología , Enfermedades de las Arterias Carótidas/patología , Aneurisma/diagnóstico , Aneurisma/cirugía , Quistes Óseos/diagnóstico , Enfermedades de las Arterias Carótidas/diagnóstico , Enfermedades de las Arterias Carótidas/cirugía , Niño , Diagnóstico Diferencial , Humanos , Masculino
14.
Neurosurgery ; 41(3): 669-72, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9310986

RESUMEN

OBJECTIVE AND IMPORTANCE: A persistent hypoglossal artery, one of the embryonic carotid-basilar anastomoses that can fail to regress in the embryo and can be observed past birth, is one of the only congenital anatomic variations of the internal carotid artery (ICA) that can complicate the performance of carotid endarterectomy. When associated with atherosclerotic carotid artery disease, the recognition and intraoperative management of a persistent hypoglossal artery is important. CLINICAL PRESENTATION: A 72-year-old man presented with a symptom of transient right hemisphere ischemia, and although ultrasonography indicated a right ICA stenosis (and no other abnormality), angiography also demonstrated that the atherosclerotic plaque extended into the origin of a large right persistent hypoglossal artery arising 1.5 cm from the origin of the ICA. In this patient, the persistent hypoglossal artery was the only arterial supply to the basilar artery. INTERVENTION: The patient underwent a right ICA endarterectomy, and intraoperative angiography was necessary to ensure that the persistent hypoglossal artery was the vessel shunted during the arterial repair. CONCLUSION: Recognition of the primitive carotid-basilar anastomoses is important to surgeons who perform carotid endarterectomy and is not possible with ultrasonography alone. Intraoperative angiography enables the surgeon to accurately catheterize a persistent hypoglossal artery with a carotid shunt.


Asunto(s)
Estenosis Carotídea/cirugía , Endarterectomía Carotidea/métodos , Malformaciones Arteriovenosas Intracraneales/cirugía , Arteria Basilar/anomalías , Arteria Basilar/diagnóstico por imagen , Arteria Basilar/cirugía , Arteria Carótida Común/anomalías , Arteria Carótida Común/diagnóstico por imagen , Arteria Carótida Común/cirugía , Estenosis Carotídea/diagnóstico por imagen , Angiografía Cerebral , Humanos , Malformaciones Arteriovenosas Intracraneales/diagnóstico por imagen , Masculino , Persona de Mediana Edad
15.
Gen Hosp Psychiatry ; 6(1): 71-6, 1984 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-6693029

RESUMEN

Psychiatrists working in consultation-liason services are often called upon to assess the competency of patients who are under the primary care of other physicians. Despite the frequency with which this sort of problem is encountered, no clinically useful guidelines seem to exist to aid the clinician in making such an assessment. In fact, a number of very different sorts of "tests" for competency to consent to medical care seem to exist and are used in practice. This essay attempts to make some headway in defining a general set of clinically useful criteria for the determination of competency to consent to medical care. This is done by looking at the central elements of informed consent itself and then asking what capabilities are required by anyone seeking to give consent to medical care.


Asunto(s)
Testimonio de Experto/legislación & jurisprudencia , Psiquiatría Forense , Consentimiento Informado/legislación & jurisprudencia , Adulto , Anciano , Femenino , Humanos , Masculino , Trastornos Mentales/diagnóstico , Trastornos Mentales/terapia , Persona de Mediana Edad , Defensa del Paciente/legislación & jurisprudencia
16.
J Biochem Biophys Methods ; 12(4): 213-25, 1986 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-3711586

RESUMEN

A novel non-invasive technique for measuring the transmembrane currents during action potential depolarizations of stalk segments of the giant unicellular alga Acetabularia mediterranea is described. This involves measurement of spatial samples of the time-dependent potential in the external medium (sea water) and an inverse transformation to give the current distribution at the cell surface. A detailed description of the method of regularization needed to handle this ill-conditioned inversion problem is presented in this paper, along with the results of test experiments to demonstrate its validity. An example of its application to the data recorded from an actual cell is also given.


Asunto(s)
Potenciales de la Membrana , Acetabularia/fisiología , Potenciales de Acción , Electrodos , Electrónica Médica
17.
J Environ Qual ; 31(2): 515-24, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-11931442

RESUMEN

A new technique is presented for the rapid, high-resolution identification and quantification of multiple trace gases above soils, at concentrations down to 0.01 microL L(-1) (10 ppb). The technique, selected ion flow tube mass spectrometry (SIFT-MS), utilizes chemical ionization reagent ions that react with trace gases but not with the major air components (N2, O2, Ar, CO2). This allows the real-time measurement of multiple trace gases without the need for preconcentration, trapping, or chromatographic separation. The technique is demonstrated by monitoring the emission of ammonia and nitric oxide, and the search for volatile organics, above containerized soil samples treated with synthetic cattle urine. In this model system, NH3 emissions peaked after 24 h at 2000 nmol m(-2) s(-1) and integrated to approximately 7% of the urea N applied, while NO emissions peaked about 25 d after urine addition at approximately 140 nmol m(-2) s(-1) and integrated to approximately 10% of the applied urea N. The monitoring of organics along with NH3 and NO was demonstrated in soils treated with synthetic urine, pyridine, and dimethylamine. No emission of volatile nitrogen organics from the urine treatments was observed at levels >0.01% of the applied nitrogen. The SIFT method allows the simultaneous in situ measurement of multiple gas components with a high spatial resolution of < 10 cm and time resolution <20 s. These capabilities allow, for example, identification of emission hotspots, and measurement of localized and rapid variations above agricultural and contaminated soils, as well as integrated emissions over longer periods.


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente/métodos , Agricultura , Gases , Iones , Espectrometría de Masas/métodos , Sensibilidad y Especificidad , Contaminantes del Suelo , Volatilización
18.
Pain Res Manag ; 6(1): 16-20, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11854757

RESUMEN

PURPOSE: To describe the results of an audit of patients who received epidural analgesics postoperatively and the subsequent development of a formal acute pain management service in a community hospital. METHODS: To understand how epidural analgesia was being used to treat postoperative pain at the Peterborough Regional Health Centre, Peterborough, Ontario, a retrospective chart review was performed. Audits were performed on 178 patients who had received epidural analgesia postoperatively from October 1994 to May 1995. Data pertaining to demographics, epidural analgesia, pain scores and side effects were collected. RESULTS: Sixty-one per cent of patients received bupivacaine/ fentanyl infusions, and 39% received epidural morphine boluses. More than 60% of patients reported no pain postoperatively. Patients who received bupivacaine/fentanyl were more likely than those who received epidural morphine to also receive co-analgesia and transitional analgesia. Patients who received epidural morphine were more likely than those who received bupivacaine fentanyl to experience respiratory depression, hypotension and pruritus. Patients were followed by the anesthesiologist who provided the anesthetic. Anesthesiologists practised independently, and formal policies and procedures did not exist. CONCLUSIONS: As a result of the audit, an acute pain management service was developed. This included a team that did daily rounds and consisted of a nurse clinician and an anesthesiologist who was assigned to the service on a weekly basis. A committee was created, and formalized policies and procedures were established. Standardized order sheets, data sheets and a computerized database were developed. Reports for administrative and quality improvement purposes were generated monthly. Education programs were developed. Co-analgesia and transitional analgesia are now part of routine care, and epidural catheter placement close to the site of incision is encouraged. A postoperative nausea and vomiting algorithm, and a treatment regimen for pruritus have also been implemented.


Asunto(s)
Analgesia Epidural , Hospitales Comunitarios , Auditoría Médica , Clínicas de Dolor/tendencias , Adulto , Anciano , Anciano de 80 o más Años , Analgesia Epidural/estadística & datos numéricos , Distribución de Chi-Cuadrado , Femenino , Hospitales Comunitarios/estadística & datos numéricos , Humanos , Masculino , Auditoría Médica/estadística & datos numéricos , Persona de Mediana Edad , Clínicas de Dolor/estadística & datos numéricos , Dolor Postoperatorio/tratamiento farmacológico , Estudios Retrospectivos
19.
Hastings Cent Rep ; 12(6): 18-20, 1982 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-7161074

RESUMEN

KIE: A 60-year-old man suffering from delusions and depression improved after an initial course of electroconvulsive therapy but then refused to continue the treatment. Doctors told him he could be committed and they eventually gained consent. Sherlock and Haykal believe the patient was treated in a morally justifiable manner. They argue that discharging the patient without treatment would have shown disrespect for his welfare, limiting rather than fostering autonomy. In contrast, Dresser contends that the physicians violated the law in administering ECT to a voluntary patient without his consent. Two legal mechanisms could have been considered: a competency hearing or a commitment proceeding.^ieng


Asunto(s)
Trastorno Depresivo/terapia , Terapia Electroconvulsiva , Ética Médica , Enfermos Mentales , Aceptación de la Atención de Salud , Humanos , Masculino , Persona de Mediana Edad , Obligaciones Morales , Autonomía Personal
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