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1.
Brain Stimul ; 15(3): 536-545, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35318122

RESUMEN

BACKGROUND: In the past decade, a rising interest in transcranial electrical stimulation has emerged owing to its advantageous capacity to facilitate the extraction of casual links between neuromodulation and the obtained behavioral effects in cognitive performance. However, an insufficient number of direct comparative studies between transcranial alternating current stimulation (tACS) and transcranial direct current stimulation (tDCS) effects on associative memory have caused optimal parameters and procedural application to remain undefined. OBJECTIVE: The current study aimed to comparatively investigate the effects of tDCS and tACS applied to the occipital nerve (ON), targeting the locus coeruleus, on associative memory performance. METHODS: We employed a randomized, double-blind, two-visit, active-controlled study design. 85 cognitively normal adults were assigned to receive either active ON-tDCS, 40 Hz ON-tACS, sham ON-tDCS, or 1 Hz ON-tACS during encoding of a 50-word Swahili-English associative memory recall task. To evaluate the effects of electrical stimulation, we measured the cumulative rate of learning on Day 1 and to assess possible long-term effects, we measured the number of words recalled on Day 7. RESULTS: Results presented two notable findings: (1) participants who received 40 Hz ON-tACS learned significantly more words on Day 1 (F3,81 = 4.37, p = .007, η2 = 0.14), and (2) participants who received 40 Hz ON-tACS or active ON-tDCS recalled significantly more words on Day 7 (F3,81 = 11.08, p < .001, η2 = 0.29). CONCLUSIONS: The evidence from this study alludes to 40 Hz ON-tACS and active ON-tDCS inducing distinct behavioral effects, whereby 40 Hz ON-tACS generated an effect during memory encoding via enhanced attention, however, active ON-tDCS elicited an offline effect transpiring during consolidation. Further neuroimaging studies are needed to validate these findings and proposed mechanisms of action.


Asunto(s)
Estimulación Transcraneal de Corriente Directa , Adulto , Humanos , Aprendizaje/fisiología , Memoria a Largo Plazo , Recuerdo Mental/fisiología , Nervios Periféricos , Estimulación Transcraneal de Corriente Directa/métodos
2.
Brain Stimul ; 14(4): 1005-1014, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34182233

RESUMEN

BACKGROUND: Previous studies show that activity in the posterior default mode network (pDMN), including the posterior cingulate cortex and the precuneus, is correlated with the success of long-term episodic memory retrieval. However, the role of the anterior DMN (aDMN) including the medial prefrontal cortex is still unclear. Some studies show that activating the medial prefrontal cortex improves memory retrieval while other studies show deactivation of the medial prefrontal cortex in successful retrieval of episodic memories, suggesting a possible functional dissociation between the aDMN and pDMN. OBJECTIVE: In the current study, we aim to causally explore this probable dissociation using high-definition transcranial direct current stimulation (HD-tDCS). METHODS: We perform a randomised double-blinded two-visit placebo-controlled study with 84 healthy young adults. During Visit 1 they learn 75 Swahili-English word-associations. Seven days later, they randomly receive either anodal, cathodal or sham HD-tDCS targeting the pDMN or aDMN while they recall what they have previously learned. RESULTS: We demonstrate that anodal stimulation of the pDMN and cathodal stimulation of the aDMN, equally improve the percentage of Swahili-English word-associations recalled 7 days after learning. CONCLUSIONS: Modulating the activity in the aDMN and pDMN causally affect memory retrieval performance. HD-tDCS of the aDMN and pDMN shows that anodal stimulation of the pDMN and cathodal stimulation of the aDMN increases memory retrieval performance one week after the learning phase. Given consistent evidence, it is highly likely that we are increasing the activity in the pDMN with anodal pDMN stimulation. However, it is not clear if cathodal HD-tDCS targetting aDMN works via decoupling from the pDMN or via indirectly disinhibit pDMN.


Asunto(s)
Memoria Episódica , Estimulación Transcraneal de Corriente Directa , Red en Modo Predeterminado , Humanos , Memoria a Largo Plazo , Recuerdo Mental , Corteza Prefrontal , Adulto Joven
3.
Eur J Neurosci ; 53(9): 3125-3141, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33738836

RESUMEN

Episodic memory retention and retrieval decline are the most common impairments observed in amnestic mild cognitive impairment (aMCI) patients who progress to Alzheimer's disease (AD). Clinical electroencephalography research shows that patients with dementia due to AD exhibit a slowing of neural electrical activity in the parietal cortex. Memory research has further suggested that successful memory performance is associated with changes in a posterior cingulate-parahippocampal cortical network together with increased θ-γ oscillatory coupling, where θ oscillations act as carrier waves for γ oscillations, which contain the actual information. However, the neurophysiological link between the memory research and clinical studies investigating aMCI and AD is lacking. In this study, we look at brain activity in aMCI and how it relates to memory performance. We demonstrate decreased γ power in the posterior cingulate cortex and the left and right parahippocampus in aMCI patients in comparison to control participants. This goes together with reduced θ coherence between the posterior cingulate cortex and parahippocampus associated with altered memory performance aMCI patients in comparison to control participants. In addition, comparing patients with aMCI to control participants reveals an effect for θ-γ coupling for the posterior cingulate cortex, and the left and right parahippocampus. Taken together, our results show that parahippocampus and posterior cingulate cortex interact via θ-γ coupling, which is associated with memory recollection and is altered in aMCI patients, offering a potential candidate mechanism for memory decline in aMCI.


Asunto(s)
Disfunción Cognitiva , Memoria Episódica , Encéfalo , Disfunción Cognitiva/diagnóstico por imagen , Giro del Cíngulo/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Trastornos de la Memoria
4.
Sci Adv ; 6(45)2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33148657

RESUMEN

An ongoing debate surrounding transcranial direct current stimulation (tDCS) of the scalp is whether it modulates brain activity both directly and in a regionally constrained manner enough to positively affect symptoms in patients with neurological disorders. One alternative explanation is that direct current stimulation affects neural circuits mainly indirectly, i.e., via peripheral nerves. Here, we report that noninvasive direct current stimulation indirectly affects neural circuits via peripheral nerves. In a series of studies, we show that direct current stimulation can cause activation of the greater occipital nerve (ON-tDCS) and augments memory via the ascending fibers of the occipital nerve to the locus coeruleus, promoting noradrenaline release. This noradrenergic pathway plays a key role in driving hippocampal activity by modifying functional connectivity supporting the consolidation of a memory event.

5.
Neurorehabil Neural Repair ; 34(11): 1020-1029, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32964776

RESUMEN

Transcutaneous electrical stimulation (tES) is a new approach that aims to stimulate the brain. Recently, we have developed tES approaches to enhance plasticity that modulate cortical activity via the greater occipital nerve (ON) in a "bottom-up" way. Thirty subjects between the ages of 55 and 70 years were enrolled and tested using a double-blind, sham-controlled, and randomized design. Half of the participants received active stimulation, while the other half received sham stimulation. Our results demonstrate that ON-tES can enhance memory in older individuals after one session, with effects persisting up to 28 days after stimulation. The hypothesized mechanism by which ON-tES enhances memory is activation of the locus coeruleus-noradrenaline (LC-NA) pathway. It is likely that this pathway was activated after ON-tES, as supported by observed changes in α-amylase concentrations, a biomarker for noradrenaline. There were no significant or long-lasting side effects observed during stimulation. Clinicaltrial.gov (NCT03467698).


Asunto(s)
Memoria/fisiología , Nervios Espinales/fisiología , Estimulación Eléctrica Transcutánea del Nervio , Anciano , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad
6.
CJEM ; 21(3): 391-394, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30295218

RESUMEN

OBJECTIVE: The objective of this study was to determine the outcomes of women who presented to the emergency department (ED) with suspected ectopic pregnancy and received methotrexate as first-line treatment. METHODS: This was a retrospective chart review of pregnant (< 12 week' gestational age) women from an academic tertiary care ED with a diagnosis of ectopic pregnancy, rule-out ectopic pregnancy, or pregnancy of unknown location over a 7-year period. RESULTS: Of 612 patients with a suspected ectopic pregnancy at initial ED presentation, 326 (53.3%) had non-ectopic pregnancy outcomes, 30 (4.9%) were diagnosed with a ruptured ectopic pregnancy at the index ED visit, and 18 (2.9%) were diagnosed and managed as non-tubal ectopic pregnancies and excluded from further analyses; 238 patients were diagnosed with a tubal ectopic pregnancy, and 152 (63.9%) were treated with methotrexate at the index ED visit or in follow-up. Of patients treated with methotrexate, 27 (17.8%) went on to require surgical management, with 17 (11.2%) documented as having ruptured on surgical evaluation. CONCLUSION: The proportion of patients failing methotrexate as first-line treatment was higher than previously reported. Further investigation is needed to determine whether methotrexate failure was due to non-adherence to recommended guidelines.


Asunto(s)
Abortivos no Esteroideos/uso terapéutico , Metotrexato/uso terapéutico , Embarazo Ectópico/tratamiento farmacológico , Embarazo Tubario/tratamiento farmacológico , Servicio de Urgencia en Hospital , Femenino , Humanos , Embarazo , Embarazo Ectópico/cirugía , Embarazo Tubario/cirugía , Estudios Retrospectivos , Rotura/cirugía
7.
Adv Health Sci Educ Theory Pract ; 20(5): 1303-24, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25835325

RESUMEN

Clinical education is foundational to health professional training. However, it is also a time of increased stress for students. A student's perception of stressors and their capacity to effectively manage them is a legitimate concern for educators, because anxiety and decreased coping strategies can interfere with effective learning, clinical performance and capacity to care for patients. Resilience is emerging as a valuable construct to underpin positive coping strategies for learning and professional practice. We report the development and evaluation of a psycho-education resilience program designed to build practical skills-based resilience capacities in health science (physiotherapy) students. Six final year undergraduate physiotherapy students attended four action research sessions led by a clinical health psychologist. Resilience strategies drawn from cognitive behavioural therapy, and positive and performance psychology were introduced. Students identified personal learning stressors and their beliefs and responses. They chose specific resilience-based strategies to address them, and then reported their impact on learning performance and experiences. Thematic analysis of the audio-recorded and transcribed action research sessions, and students' de identified notes was conducted. Students' initial descriptions of stressors as 'problems' outside their control resulting in poor thinking and communication, low confidence and frustration, changed to a focus on how they managed and recognized learning challenges as normal or at least expected elements of the clinical learning environment. The research suggests that replacing stressful challenges with positive coping strategies offers a potentially powerful tool to build self-efficacy and cognitive control as well as greater self-awareness as a learner and future health practitioner.


Asunto(s)
Prácticas Clínicas , Educación del Paciente como Asunto/métodos , Especialidad de Fisioterapia/educación , Estrés Psicológico/prevención & control , Estrés Psicológico/terapia , Estudiantes/psicología , Adaptación Psicológica , Concienciación , Comunicación , Humanos , Atención Plena , Percepción , Resiliencia Psicológica , Autoeficacia
8.
Child Care Health Dev ; 39(4): 481-9, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23763249

RESUMEN

OBJECTIVE: The aim of this study was to establish the construct validity of the Focus on the Outcomes of Communication Under Six (FOCUS©). This measure is reflective of concepts in the International Classification of Functioning Disability and Health--Children and Youth framework. It was developed to capture 'real-world' changes (e.g. communicative participation) in preschoolers' communication following speech-language intervention. METHOD: A pre-post design was used. Fifty-two parents of 3- to 6-year-old preschoolers attending speech-language therapy were included as participants. Speech-language therapists provided individual and/or group intervention to preschoolers. Intervention targeted: articulation/phonology, voice/resonance, expressive/receptive language, play, and use of augmentative devices. Construct validity for communicative participation was assessed using pre-intervention and post-intervention parent interviews using the FOCUS© and the communication and socialization domains of the Vineland Adaptive Behavior Scales-II (VABS-II). RESULTS: Significant associations were found between the FOCUS©, measuring communicative participation, and the VABS-II domains for: (i) pre-intervention scores in communication (r = 0.53, P < 0.001; 95% CI 0.30-0.70) and socialization (r = 0.67, P < 0.001; 95% CI 0.48-0.80); (ii) change scores over-time in communication (r = 0.45, P < 0.001; 95% CI 0.201-0.65) and socialization (r = 0.39, P = 0.002; 95% CI 0.13-0.60); and (iii) scores at post-intervention for communication (r = 0.53, P < 0.001; 95% CI 0.30-0.70) and for socialization (r = 0.37, P = 0.003; 95% CI 0.11-0.50). CONCLUSIONS: The study provided evidence on construct validity of the FOCUS© for evaluating real-world changes in communication. We believe that the FOCUS© is a useful measure of communicative participation.


Asunto(s)
Trastornos del Desarrollo del Lenguaje/terapia , Evaluación de Resultado en la Atención de Salud/normas , Reproducibilidad de los Resultados , Niño , Preescolar , Trastornos de la Comunicación , Estudios de Evaluación como Asunto , Femenino , Humanos , Terapia del Lenguaje , Masculino , Participación Social , Logopedia , Resultado del Tratamiento
9.
J Comp Physiol B ; 183(6): 843-58, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23386120

RESUMEN

We used doubly labelled water to measure field metabolic rates (FMR) and water turnover rates (WTR) in one of Australia's largest native herbivores, the red kangaroo (Macropus rufus) and one of Australia's dominant livestock species, the wool-breed Merino sheep, under free-living conditions in a typical Australian rangeland. Also, we used GPS technology to examine animal space use, along with the comparisons of urine concentration, diet, diet digestibility, and subsequent grazing pressures. We found smaller space-use patterns than previously reported for kangaroos, which were between 14 and 25 % those of sheep. The FMR of a 25-kg kangaroo was 30 % that of a 45-kg sheep, while WTR was 15 % and both were associated with smaller travel distances, lower salt intakes, and higher urine concentration in kangaroos than sheep. After accounting for differences in dry matter digestibility of food eaten by kangaroos (51 %) and sheep (58 %), the relative grazing pressure of a standard (mature, non-reproductive) 25-kg kangaroo was 35 % that of a 45-kg sheep. Even for animals of the same body mass (35 kg), the relative grazing pressure of the kangaroo was estimated to be only 44 % that of the sheep. After accounting for the energetic costs of wool growth by sheep, the FMRs of our sheep and kangaroos were 2-3 times their expected BMRs, which is typical for mammalian FMR:BMRs generally. Notably, data collected from our free-living animals were practically identical to those from animals confined to a semi-natural enclosure (collected in an earlier study under comparable environmental conditions), supporting the idea that FMRs are relatively constrained within species.


Asunto(s)
Metabolismo Energético/fisiología , Macropodidae/fisiología , Oveja Doméstica/fisiología , Agua/metabolismo , Animales , Australia , Deuterio , Ecología , Ambiente , Femenino , Sistemas de Información Geográfica , Macropodidae/sangre , Macropodidae/orina , Concentración Osmolar , Isótopos de Oxígeno , Oveja Doméstica/sangre , Oveja Doméstica/orina
10.
Eye (Lond) ; 26(9): 1226-31, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22744392

RESUMEN

PURPOSE: To analyse predictors of clinical outcome in fungal keratitis. METHODS: Data was collected during a prospective, randomized, controlled, double-masked clinical trial of treatment for fungal keratitis. Clinical features at presentation and demographics were collected at the enrollment visit for all patients. Pre-specified clinical outcomes included 3-month visual acuity and infiltrate/scar size, time to re-epithelialization, and corneal perforation. A separate multivariable model with each outcome as the dependent variable included all predictor variables. RESULTS: Predictors for worse 3-month visual acuity include older age (P=0.024), worse presentation visual acuity (P<0.001), larger infiltrate size at presentation (P<0.001), and pigmented ulcer (P=0.030). Larger infiltrate size at presentation was a significant predictor of worse 3-month infiltrate/scar size (P<0.001). Larger epithelial defect size was a significant predictor of perforation (P=0.0013). Predictors of longer time to re-epithelialization include infiltrate size at presentation (P<0.001) and older age (P=0.025). CONCLUSION: Ulcer severity at presentation is highly predictive of worse outcomes. Presentation of clinical characteristics such as baseline acuity and infiltrate scar can provide important information to clinicians about prognosis, and may help guide management and treatment decisions. Prevention of corneal ulcer remains important, as it is difficult to change the course of the ulcer once it has begun.


Asunto(s)
Úlcera de la Córnea/diagnóstico , Infecciones Fúngicas del Ojo/diagnóstico , Administración Tópica , Antifúngicos/uso terapéutico , Perforación Corneal/diagnóstico , Úlcera de la Córnea/tratamiento farmacológico , Úlcera de la Córnea/microbiología , Desbridamiento , Método Doble Ciego , Infecciones Fúngicas del Ojo/tratamiento farmacológico , Infecciones Fúngicas del Ojo/microbiología , Femenino , Humanos , Masculino , Natamicina/uso terapéutico , Soluciones Oftálmicas , Evaluación de Procesos y Resultados en Atención de Salud , Pronóstico , Estudios Prospectivos , Pirimidinas/uso terapéutico , Repitelización , Factores de Riesgo , Factores de Tiempo , Triazoles/uso terapéutico , Agudeza Visual/fisiología , Voriconazol
11.
J Viral Hepat ; 19(2): 112-9, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22239500

RESUMEN

Hepatitis C virus (HCV) is commonly transmitted by intravenous drug use (IDU) but drug users are under represented in many treatment cohorts, this is because of the assumption of lowered treatment success. We assessed HCV treatment outcomes in active intravenous drug users and patients on opiate substitution therapy. The Tayside HCV treatment database was retrospectively analysed for consecutively treated patients based on risk factor for acquisition of HCV. Primary end point was sustained virological response (SVR). Two hundred and ninety-one consecutively treated patients were assessed. The overall SVR rate was 55.3%. The SVR rates by risk factor were; Non-IDU 61.4%, Ex-IDU 54.8% and Active IDU 47.1% (P = n/s). In the groups G1 patients SVR was; Non-IDU 52.7%, Ex-IDU 30.7% and active IDU 35.4% (P = n/s). In the non-G1 patients: non-IDU 65.1%, Ex-IDU 76.7% and active IDU 53.5%. Ex-IDU had a significantly better SVR than active IDU, other differences were not significant. Our results demonstrate that SVR rates in the active drug users and those on opiate substitution therapy can be achieved which are comparable with non-IDU infected individuals. Intravenous drug use in those engaged with treatment services should not be seen as a barrier to treatment of HCV.


Asunto(s)
Antivirales/administración & dosificación , Hepatitis C/complicaciones , Hepatitis C/tratamiento farmacológico , Abuso de Sustancias por Vía Intravenosa/complicaciones , Abuso de Sustancias por Vía Intravenosa/tratamiento farmacológico , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento , Carga Viral
12.
Artículo en Inglés | MEDLINE | ID: mdl-22079103

RESUMEN

Feral goats (Capra hircus) are ubiquitous across much of Australia's arid and semi-arid rangelands, where they compete with domestic stock, contribute to grazing pressure on fragile ecosystems, and have been implicated in the decline of several native marsupial herbivores. Understanding the success of feral goats in Australia may provide insights into management strategies for this and other invasive herbivores. It has been suggested that frugal use of energy and water contributes to the success of feral goats in Australia, but data on the energy and water use of free-ranging animals are lacking. We measured the field metabolic rate and water turnover rate of pregnant and non-pregnant feral goats in an Australian rangeland during late summer (dry season). Field metabolic rate of pregnant goats (601 ± 37 kJ kg(-0.73)d(-1)) was 1.3 times that of non-pregnant goats (456 ± 24 kJ kg(-0.73)d(-1)). The water turnover rate of pregnant goats (228 ± 18 mL kg(-0.79)d(-1)) was also 1.3 times that of non-pregnant goats (173 ± 18 kg(-0.79)d(-1)), but the difference was not significant (P=0.07). There was no significant difference in estimated dry matter digestibility between pregnant and non-pregnant goats (mean ca. 58%), blood or urine osmolality, or urine electrolyte concentrations, indicating they were probably eating similar diets and were able to maintain osmohomeostasis. Overall, the metabolic and hygric physiology of non-pregnant goats conformed statistically to the predictions for non-marine, non-reproductive placental mammals according to both conventional and phylogenetically independent analyses. That was despite the field metabolic rate and estimated dry matter intake of non-pregnant goats being only 60% of the predicted level. We suggest that general allometric analyses predict the range of adaptive possibilities for mammals, but that specific adaptations, as present in goats, result in ecologically significant departures from the average allometric curve. In the case of goats in the arid Australian rangelands, predictions from the allometric regression would overestimate their grazing pressure by about 40% with implications for the predicted impact on their local ecology.


Asunto(s)
Ecosistema , Metabolismo Energético/fisiología , Cabras/anatomía & histología , Cabras/fisiología , Especies Introducidas , Agua/fisiología , Animales , Metabolismo Basal/fisiología , Agua Corporal/fisiología , Peso Corporal/fisiología , Digestión/fisiología , Electrólitos/sangre , Electrólitos/orina , Femenino , Concentración Osmolar , Filogenia , Embarazo , Análisis de Regresión , Especificidad de la Especie
13.
Eye (Lond) ; 25(9): 1155-60, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21637300

RESUMEN

AIMS: The purpose of this study was to estimate the duration of treatment necessary for sequential acanthamoeba laboratory tests from corneal scrapings to become negative, and to assess predictors that affect this duration period. METHODS: We included all patients with at least one positive acanthamoeba culture or Giemsa stain at the F.I. Proctor Foundation Microbiology Laboratory from 1996 to 2009. A parametric survival analysis was performed among patients with repeat cultures to assess significant predictors for extended clearance time. Simulations were performed to estimate clearance time in the entire patient population, assuming imperfect sensitivity. RESULTS: Thirty-seven patients with laboratory evidence of acanthamoeba had testing at 69 time points. The median clearance time among eyes with repeat cultures was 42.5 days (interquartile range (IQR) 22.0-82.0 days; unadjusted parametric model). Initial visual acuity was the only predictor significantly associated with clearance time in univariate analyses (P<0.0001). Using initial visual acuity as a predictor for clearance time among the entire patient population, the estimated clearance time decreased to 38.7 days (95% confidence interval (CI) 27.9-53.5 days). When the imperfect sensitivity of the culture technique was also taken into account, the estimated clearance time was 44.1 days (95% CI 31.9-61.0 days). CONCLUSION: The duration of infection with acanthamoeba keratitis undergoing treatment has not been well characterized. In this report we estimate a median clearance time of approximately 6 weeks, with an IQR of 22-82 days.


Asunto(s)
Queratitis por Acanthamoeba/microbiología , Acanthamoeba/aislamiento & purificación , Queratitis por Acanthamoeba/tratamiento farmacológico , Queratitis por Acanthamoeba/fisiopatología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antiparasitarios/uso terapéutico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Tiempo , Agudeza Visual/fisiología , Adulto Joven
14.
J Dairy Sci ; 93(10): 4774-80, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20855011

RESUMEN

Eight primiparous and 8 multiparous Holstein cows were used to determine the effects of Cr supplementation, in the form of Cr propionate (Cr Prop), on milk and tissue Cr concentrations. Cows were randomly assigned by parity to one of 2 diets: 1) control diet or 2) 2 mg of supplemental Cr/kg of DM. The level of Cr Prop supplemented exceeded by 4-fold the concentration of 0.5 mg of Cr/kg permitted by the FDA. Experimental diets were fed from approximately 30 d prepartum until at least 91 d postpartum, resulting in a minimum of 121 d of exposure to supplemental Cr. The control prepartum and postpartum diets analyzed 0.48 and 0.38 mg of Cr/kg of DM, respectively. Milk samples were obtained from the a.m. milking on d 0 (colostrum), 7, 14, 21, 28, 42, 56, 77, and 90 and on the final day of the study for Cr analysis. Cows were harvested after lactating for a minimum of 91 d and samples of liver, kidney, semitendinosus muscle, and fat were obtained for Cr analysis. Chromium was measured using electrothermal atomic absorption spectrophotometry. Milk Cr concentration averaged 1.7 ng/mL and was affected by day of lactation but not by Cr or a Cr × day interaction. Supplementation of 2 mg of Cr/kg of DM increased kidney Cr by approximately 3-fold and liver Cr concentrations by approximately 2-fold. Chromium concentrations in muscle and fat were not affected by Cr supplementation. In summary, supplementation of Cr Prop at a level of 2 mg of Cr/kg of DM did not affect Cr concentration in milk, muscle, or fat, the major bovine products consumed by humans.


Asunto(s)
Bovinos/metabolismo , Suplementos Dietéticos , Leche/química , Propionatos/administración & dosificación , Alimentación Animal , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Dieta/veterinaria , Femenino
15.
Endocrinology ; 151(6): 2689-99, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20392837

RESUMEN

Inflammatory molecules, such as cyclooxygenase (COX), a prostaglandin synthetic enzyme, have been identified as a marker of depressive symptomology. Previously, we have observed elevated basal COX-2 expression in the hypothalamus of adult male rats treated neonatally with lipopolysaccharide (LPS), which might suggest a phenotype for disrupted hedonic behavior, a symptom of depression. However, COX-2 and its contribution to the expression of anhedonic behavior has not been investigated in these males or in female rats across the estrous cycle, which is the purpose of the current work. Here, we examine the effects of a neonatal LPS challenge or saline on the sucrose preference test as a measure of anhedonia, and hypothalamic COX-2 expression, in adult male and freely cycling female rats. Our data indicate a sex difference in that neonatal LPS at postnatal d 14 causes elevated basal expression of hypothalamic COX-2 in male, but not in female, rats. Additionally, baseline sucrose preference in male and female rats was unaltered as a function of neonatal LPS treatment or estrous cycle stage. In both male and female animals, 50 microg/kg LPS in adulthood caused elevated plasma IL-6 and hypothalamic COX-2 expression in neonatally saline-treated rats but significantly less so in neonatally LPS-treated rats of both sexes; this neonatal programming was not evident for sucrose preference or for total fluid intake (even after much higher doses of LPS). Our data are suggestive of a dissociation between inflammation and anhedonic behavior and a differential effect of neonatal inflammation in males and females.


Asunto(s)
Inflamación/metabolismo , Factores Sexuales , Animales , Animales Recién Nacidos , Western Blotting , Ciclooxigenasa 2/metabolismo , Ensayo de Inmunoadsorción Enzimática , Ciclo Estral/efectos de los fármacos , Femenino , Hipotálamo/efectos de los fármacos , Hipotálamo/metabolismo , Inflamación/sangre , Inflamación/inducido químicamente , Interleucina-6/sangre , Lipopolisacáridos/toxicidad , Masculino , Embarazo , Ratas
16.
J Viral Hepat ; 17(10): 698-704, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20002561

RESUMEN

Infection with the hepatitis C virus commonly occurs in patient groups who have difficulty accessing conventional medical care, reducing their chance of successful antiviral therapy. Managed care networks (MCNs) have been suggested as a mechanism of improving access to care; however, there is little evidence to support their use in patients with hepatitis C. The aim of this study was to evaluate the impact of a MCN for patients with hepatitis C. This was a retrospective cohort study of all individuals in our area who had received a positive hepatitis C antibody test between August 1994 and June 2008. The MCN introduced a new referral pathway, which included nonmedical referrals and outreach nurse-led clinics. These interventions were introduced in 2004 and evaluated in 2008. After the introduction of the MCN, the proportion of individuals who accessed care increased from 61% (280/430) to 82.4% (721/875). There was an increase in nonmedical referrals with 81 (18.3%) being directly referred from Drug Problem Services and 75 (17%) from the Prison Service. The changes to referral did not have a negative impact on treatment outcomes as the number who completed treatment increased from 66.1% (43/65) to 73.7% (98/133) and the sustained virological response increased from 50.7% (33/65) to 60.9% (81/133). This study provides evidence that the collaboration of health care professionals within a network can have a radical effect in improving access to care in a traditionally hard to reach population. This has been achieved with little additional resource, but rather working smarter with existing staff.


Asunto(s)
Investigación sobre Servicios de Salud , Hepatitis C/terapia , Programas Controlados de Atención en Salud , Adolescente , Adulto , Estudios de Cohortes , Femenino , Humanos , Masculino , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
18.
Br J Ophthalmol ; 93(1): 116-9, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18952649

RESUMEN

BACKGROUND/AIMS: To study the susceptibility of Fusarium and Aspergillus isolated from keratitis to amoxicillin, cefazolin, chloramphenicol, moxifloxacin, tobramycin and benzalkonium chloride (BAK). METHODS: 10 isolates of Fusarium and 10 isolates of Aspergillus from cases of fungal keratitis at Aravind Eye Hospital in South India were tested using microbroth dilution for susceptibility to amoxicillin, cefazolin, chloramphenicol, moxifloxacin, tobramycin and BAK. The minimum inhibitory concentration (MIC) median and 90th percentile were determined. RESULTS: BAK had the lowest MIC for both Fusarium and Aspergillus. Chloramphenicol had activity against both Fusarium and Aspergillus, while moxifloxacin and tobramycin had activity against Fusarium but not Aspergillus. CONCLUSIONS: The susceptibility of Fusarium to tobramycin, moxifloxacin, chloramphenicol and BAK and of Aspergillus to chloramphenicol and BAK may explain anecdotal reports of fungal ulcers that improved with antibiotic treatment alone. While some of the MICs of antibiotics and BAK are lower than the typically prescribed concentrations, they are not in the range of antifungal agents such as voriconazole, natamycin and amphotericin B. Antibiotics may, however, have a modest effect on Fusarium and Aspergillus when used as initial treatment prior to identification of the pathological organism.


Asunto(s)
Antibacterianos/uso terapéutico , Antifúngicos/uso terapéutico , Aspergillus/efectos de los fármacos , Fusarium/efectos de los fármacos , Aspergilosis/microbiología , Úlcera de la Córnea/microbiología , Farmacorresistencia Fúngica/efectos de los fármacos , Infecciones Fúngicas del Ojo/microbiología , Femenino , Humanos , India , Masculino , Pruebas de Sensibilidad Microbiana , Micosis/microbiología , Estudios Prospectivos
19.
Br J Ophthalmol ; 93(2): 198-202, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18829631

RESUMEN

AIMS: The aim of the study was to conduct a preliminary clinical trial to assess whether adjunctive topical corticosteroids improve outcomes in bacterial keratitis and, if no difference was found, to determine the feasibility and sample size necessary for conducting a larger trial to answer this question. METHODS: In this single centre, double-masked clinical trial, 42 patients with culture-confirmed bacterial keratitis at Aravind Eye Hospital in India were randomised to receive either topical prednisolone phosphate or placebo. All patients received topical moxifloxacin. The primary outcome was best spectacle-corrected visual acuity (BSCVA) at 3 months, adjusting for enrolment BSCVA and arm. Other pre-specified outcomes included re-epithelialisation time, infiltrate/scar size and adverse events. RESULTS: Compared with placebo, patients in the steroid group re-epithelialised more slowly (hazard ratio 0.47, 95% CI 0.23 to 0.94). There was no significant difference in BSCVA or infiltrate/scar size at 3 weeks or 3 months. To have 80% power to detect a two-line difference in acuity, 360 cases would be required. CONCLUSIONS: Although corticosteroid treatment resulted in a statistically significant delay in re-epithelialisation, this did not translate to a significant difference in visual acuity, infiltrate/scar size or adverse events. To assess the effect of steroids on acuity, a larger trial is warranted and feasible.


Asunto(s)
Úlcera de la Córnea/tratamiento farmacológico , Infecciones Bacterianas del Ojo/tratamiento farmacológico , Glucocorticoides/uso terapéutico , Prednisolona/análogos & derivados , Adulto , Anciano , Úlcera de la Córnea/microbiología , Úlcera de la Córnea/fisiopatología , Método Doble Ciego , Epitelio Corneal/fisiología , Infecciones Bacterianas del Ojo/fisiopatología , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Soluciones Oftálmicas , Prednisolona/uso terapéutico , Resultado del Tratamiento , Agudeza Visual/efectos de los fármacos , Cicatrización de Heridas/efectos de los fármacos
20.
Br J Ophthalmol ; 93(3): 322-8, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18621790

RESUMEN

BACKGROUND: To compare the ability of Glaucoma Progression Analysis (GPA) and Threshold Noiseless Trend (TNT) programs to detect visual-field deterioration. METHODS: Patients with open-angle glaucoma followed for a minimum of 2 years and a minimum of seven reliable visual fields were included. Progression was assessed subjectively by four masked glaucoma experts, and compared with GPA and TNT results. Each case was judged to be stable, deteriorated or suspicious of deterioration RESULTS: A total of 56 eyes of 42 patients were followed with a mean of 7.8 (SD 1.0) tests over an average of 5.5 (1.04) years. Interobserver agreement to detect progression was good (mean kappa = 0.57). Progression was detected in 10-19 eyes by the experts, in six by GPA and in 24 by TNT. Using the consensus expert opinion as the gold standard (four clinicians detected progression), the GPA sensitivity and specificity were 75% and 83%, respectively, while the TNT sensitivity and specificity was 100% and 77%, respectively. CONCLUSION: TNT showed greater concordance with the experts than GPA in the detection of visual-field deterioration. GPA showed a high specificity but lower sensitivity, mainly detecting cases of high focality and pronounced mean defect slopes.


Asunto(s)
Diagnóstico por Computador/métodos , Glaucoma de Ángulo Abierto/diagnóstico , Campos Visuales , Anciano , Competencia Clínica , Gráficos por Computador , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Glaucoma de Ángulo Abierto/fisiopatología , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Sensibilidad y Especificidad , Pruebas del Campo Visual
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