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1.
Hum Brain Mapp ; 45(14): e70002, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39365253

RESUMEN

Subtle motor signs are a common feature in children with attention-deficit/hyperactivity disorder (ADHD). It has long been suggested that white matter abnormalities may be involved in their presentation, though no study has directly probed this question. The aim of this study was to investigate the relationship between white matter organization and the severity of subtle motor signs in children with and without ADHD. Participants were 92 children with ADHD aged between 8 and 12 years, and 185 typically developing controls. Subtle motor signs were examined using the Physical and Neurological Examination for Soft Signs (PANESS). Children completed diffusion MRI, and fixel-based analysis was performed after preprocessing. Tracts of interest were delineated using TractSeg including the corpus callosum (CC), the bilateral corticospinal tracts (CST), superior longitudinal fasciculus, and fronto-pontine tracts (FPT). Fiber cross-section (FC) was calculated for each tract. Across all participants, lower FC in the CST was associated with higher PANESS Total score (greater motor deficits). Within the PANESS, similar effects were observed for Timed Left and Right maneuvers of the hands and feet, with lower FC of the CST, CC, and FPT associated with poorer performance. No significant group differences were observed in FC in white matter regions associated with PANESS performance. Our data are consistent with theoretical accounts implicating white matter organization in the expression of motor signs in childhood. However, rather than contributing uniquely to the increased severity of soft motor signs in those with ADHD, white matter appears to contribute to these symptoms in childhood in general.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad , Sustancia Blanca , Humanos , Niño , Masculino , Trastorno por Déficit de Atención con Hiperactividad/diagnóstico por imagen , Trastorno por Déficit de Atención con Hiperactividad/fisiopatología , Trastorno por Déficit de Atención con Hiperactividad/patología , Femenino , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/patología , Imagen de Difusión por Resonancia Magnética , Tractos Piramidales/diagnóstico por imagen , Tractos Piramidales/patología , Tractos Piramidales/fisiopatología , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Encéfalo/fisiopatología
2.
J Int Neuropsychol Soc ; 28(4): 371-381, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-33998435

RESUMEN

OBJECTIVES: The presence of excessive mirror overflow in children with Attention Deficit/Hyperactivity Disorder (ADHD) is discussed in numerous published reports. These reports, however, include a limited age range in their samples. The objective of this study is to examine the effects of diagnosis and sex on mirror overflow and standard deviation (SD) of tap time in children with and without ADHD across a larger age range (5-12 years) of children. METHODS: One-hundred and forty-eight children with ADHD and 112 age- and sex-matched typically developing (TD) children completed a finger sequencing task. Mirror overflow, SD of tap time, and mean tap time were measured using finger twitch transducers. RESULTS: Results reveal a significant diagnostic effect on mirror overflow such that boys and girls with ADHD demonstrate increased overflow compared to same-sex TD children. Boys with ADHD demonstrated more variable tap times compared to TD boys; no diagnostic effect was observed in the girls. CONCLUSIONS: Boys with ADHD exhibit anomalous motor variability; girls with ADHD show similar levels of variability as TD girls. Boys and girls with ADHD exhibit similar levels of excessive mirror overflow. This lack of sex differences on mirror overflow is distinct from reports finding sex effects on overflow and could result from an examination of a broader age range than is included in prior reports. Adolescent data would provide a greater understanding of the trajectory of anomalous mirror overflow across development. Examination of functional and structural connectivity would expand the current understanding of the neurobiological foundation of motor overflow.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad , Adolescente , Niño , Preescolar , Femenino , Humanos , Masculino
3.
J Undergrad Neurosci Educ ; 17(2): A125-A129, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31360128

RESUMEN

Undergraduate students studying neuroscience have limited opportunities to develop and apply teaching skills before joining a graduate program. Once in a graduate program, students in neuroscience programs are often hired as teaching assistants, adjuncts, or instructors of record. We propose that a low-cost, mentored, short-term summer neuroscience brain academy with high school student participants provides undergraduate students with critical introductory neuroscience teaching experience. Additionally, the experience serves as a service-learning opportunity for faculty and student personnel in a neuroscience laboratory. In this specific program, undergraduate students generate and deliver neuroscience lessons to high school students under the mentorship of a faculty member. This article contains an overview of the purpose of the summer academy, budgetary considerations, materials required, and the roles of faculty and students, with the goal that this model can be replicated at other universities. We propose that this experience addresses a critical gap in early neuroscience professional training.

4.
Cereb Cortex ; 26(5): 1997-2005, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-25681421

RESUMEN

Many theories of visual object perception assume the visual system initially extracts borders between objects and their background and then "fills in" color to the resulting object surfaces. We investigated the transformation of chromatic signals across the human ventral visual stream, with particular interest in distinguishing representations of object surface color from representations of chromatic signals reflecting the retinal input. We used fMRI to measure brain activity while participants viewed figure-ground stimuli that differed either in the position or in the color contrast polarity of the foreground object (the figure). Multivariate pattern analysis revealed that classifiers were able to decode information about which color was presented at a particular retinal location from early visual areas, whereas regions further along the ventral stream exhibited biases for representing color as part of an object's surface, irrespective of its position on the retina. Additional analyses showed that although activity in V2 contained strong chromatic contrast information to support the early parsing of objects within a visual scene, activity in this area also signaled information about object surface color. These findings are consistent with the view that mechanisms underlying scene segmentation and the binding of color to object surfaces converge in V2.


Asunto(s)
Percepción de Color/fisiología , Visión de Colores/fisiología , Percepción de Forma/fisiología , Sensibilidad de Contraste , Femenino , Humanos , Masculino , Análisis Multivariante , Estimulación Luminosa , Propiedades de Superficie
5.
Intern Med J ; 44(9): 903-10, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24963727

RESUMEN

BACKGROUND: Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are an important cause of acute hospital admissions and incur significant costs, which include antibiotic costs. AIMS: This study aimed to (i) define antibiotic prescribing practice in patients admitted to a tertiary hospital with AECOPD and compare this with current locally and nationally recognised antibiotic prescribing guidelines and (ii) correlate variations in guideline-concordant antibiotic prescribing with mean length of stay (LOS) and rates of unplanned readmission to hospital. METHODS: Retrospective case series of 84 consecutive patients with uncomplicated AECOPD who met pre-specified selection criteria. RESULTS: Seventy-two of 84 participants (85.7%) received guideline-discordant antibiotics, of whom the majority (76%) received intravenous antibiotics. Mean LOS was significantly lower among patients receiving guideline-concordant therapy compared with those receiving guideline-discordant therapy (mean 1.6 days vs 3.7 days; P = 0.002). There was no significant difference between groups in rates of readmission. Estimated excess costs per patient associated with guideline-discordant therapy equalled $2642 which, if eliminated, would save approximately $300 000 per annum. CONCLUSION: In a tertiary hospital, Australian guidelines for treating patients with an AECOPD were rarely followed. The use of guideline-discordant therapy resulted in longer hospital stays and incurred greater costs. Studies are required to determine the reasons behind such discordant practice and to develop initiatives to improve antibiotic prescribing.


Asunto(s)
Antibacterianos/administración & dosificación , Adhesión a Directriz , Infecciones por Haemophilus/prevención & control , Infecciones Neumocócicas/prevención & control , Infecciones por Pseudomonas/prevención & control , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Infecciones Estafilocócicas/prevención & control , Corticoesteroides/administración & dosificación , Corticoesteroides/economía , Anciano , Antibacterianos/economía , Australia/epidemiología , Progresión de la Enfermedad , Femenino , Costos de la Atención en Salud , Hospitalización/estadística & datos numéricos , Humanos , Tiempo de Internación/estadística & datos numéricos , Masculino , Terapia por Inhalación de Oxígeno/economía , Terapia por Inhalación de Oxígeno/estadística & datos numéricos , Readmisión del Paciente/estadística & datos numéricos , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Estudios Retrospectivos , Centros de Atención Terciaria/estadística & datos numéricos
6.
J Laryngol Otol ; 137(4): 408-412, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35606896

RESUMEN

BACKGROUND: Epistaxis can be life-threatening. Simple first aid management can stem bleeding. This study compared knowledge of first aid management methods of epistaxis between the general public and healthcare workers. METHOD: A cross-sectional study of 100 healthcare workers and 103 adult members of the public was conducted at a large London teaching hospital. Respondents completed a survey assessing knowledge on nasal pinching site, head tilt and appropriate adjunct treatment use for first aid management of epistaxis. RESULTS: Twenty-four per cent and 68 per cent of healthcare workers compared with 25.2 per cent and 37.9 per cent of the public answered correctly on nasal pinching position and head tilt position, respectively, with a statistical difference for head tilt position. Two per cent, 2 per cent and 24 per cent of healthcare workers mentioned ice use on the nose, ice use in the mouth or ice use but not site, respectively, compared with 0 per cent, 0 per cent and 4.9 per cent of the public, with a statistical difference for ice without site. CONCLUSION: Healthcare workers and the public lack knowledge on first aid management of epistaxis. Improved education on first aid management is required, targeting healthcare workers and the public.


Asunto(s)
Epistaxis , Primeros Auxilios , Adulto , Humanos , Epistaxis/terapia , Estudios Transversales , Hielo , Nariz
7.
J Laryngol Otol ; 136(11): 1044-1050, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34674777

RESUMEN

OBJECTIVE: Granular myringitis is a chronic and difficult-to-treat condition of the tympanic membrane. This paper presents a minimally invasive treatment technique using the potassium titanyl phosphate laser. DESIGN: A retrospective case review of patients who underwent potassium titanyl phosphate laser treatment between 2015 and 2020 was performed. All patients underwent final telephone follow up in 2020 to ascertain whether they had any ongoing myringitis symptoms, and all were offered further face-to-face follow up. RESULTS: Fourteen patients with myringitis were identified, with one patient having both ears affected. Of the 15 affected ears, 2 required a second treatment, resulting in a total of 17 laser treatment cases. At the first post-operative review, the appearance of the drum had improved in 10 out of 17 treatments (59 per cent). CONCLUSION: Potassium titanyl phosphate laser surface tympanoplasty may provide safe, quick and effective resolution of myringitis.


Asunto(s)
Láseres de Estado Sólido , Otitis Media , Timpanoplastia , Humanos , Enfermedad Crónica , Láseres de Estado Sólido/uso terapéutico , Otitis Media/cirugía , Estudios Retrospectivos , Resultado del Tratamiento , Membrana Timpánica , Timpanoplastia/métodos
8.
Radiats Biol Radioecol ; 51(1): 76-80, 2011.
Artículo en Ruso | MEDLINE | ID: mdl-21520619

RESUMEN

The purpose of this work was the analysis of the effects of bystander factors from blood sera of people affected by the Chernobyl accident on human keratinocyte cell culture (HPV-G cells). A new method was developed for evaluation of the bystander factor presence in vivo in blood of the people irradiated by the Chernobyl accident. Affected population groups included liquidators of the Chernobyl accident and people living and working in areas of the Gomel region contaminated by radionuclides. The analysis has shown that bystander factors persist in Chernobyl liquidator blood samples for more than 20 years since irradiation. The data suggest that blood sera contain bystander factors, which are able to induce micronuclei and decrease the metabolic activity of HPV-G cells.


Asunto(s)
Factores Biológicos/farmacología , Efecto Espectador/genética , Accidente Nuclear de Chernóbil , Suero/efectos de la radiación , Factores Biológicos/sangre , Estudios de Casos y Controles , Técnicas de Cultivo de Célula , Línea Celular , Humanos , Queratinocitos/efectos de los fármacos , Queratinocitos/metabolismo , Queratinocitos/ultraestructura , Melaninas/farmacología , Melatonina/farmacología , Micronúcleos con Defecto Cromosómico/efectos de la radiación , Pruebas de Micronúcleos , Protectores contra Radiación/farmacología , Suero/química , Ucrania
9.
Physiotherapy ; 110: 77-84, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33153764

RESUMEN

OBJECTIVE: To explore the clinical reasoning of physiotherapists using PDSAFE; according to disease severity and their experiences of treatment delivery in a large fall-prevention trial for people with Parkinson's (PwP). DESIGN: A descriptive study of delivering PDSAFE. Semi-structured interviews explored therapists' experiences. SETTING: A two-group, home-based, multi-centred, single-blinded, randomised controlled trial showed no overall effect on fall reduction between groups but demonstrated a significant secondary effect relating to disease severity with benefits to balance, falls efficacy and near-falls for all. PARTICIPANTS: Physiotherapists with a background in neurology and older-person rehabilitation were trained in the delivery of PDSAFE INTERVENTION: A multi-dimensional, individually tailored and progressive, home-based programme. RESULTS: Fifteen physiotherapists contributed to the 2587 intervention sessions from the PDSAFE trial and six of those physiotherapists took part in the interviews. The personalised intervention was reflected in the range of strategies and exercises prescribed. Most commonly prescribed fall-avoidance strategies were 'Avoiding tripping', 'Turning' and 'Freezing Cues' and all possible combinations of balance and strength training within the programme were selected. PwP with greater disease severity were more likely to have received less challenging strategies, balance and strengthening exercises than those with lower disease severity. Therapists considered the focus on fall events and fall avoidance strategies an improvement on 'impairment only' treatment. The presence of cognitive deficits, co-morbidities and dyskinesia were the most challenging aspects of delivering the intervention. CONCLUSION: Falls management for PwP is complex and compounded by the progressive nature of the condition. Physiotherapists both delivered and positively received PDSAFE. (248 words) The trial registration number is ISRCTN 48152791.


Asunto(s)
Accidentes por Caídas/prevención & control , Toma de Decisiones Clínicas , Terapia por Ejercicio/métodos , Enfermedad de Parkinson/rehabilitación , Fisioterapeutas , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Método Simple Ciego , Encuestas y Cuestionarios
10.
Surgeon ; 8(3): 132-5, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20400021

RESUMEN

BACKGROUND & AIM: Current Laparoscopic simulators have limited usefulness and patients have been used for training since the dawn of surgery. NUGITS (Northumbrian Upper Gastro Intestinal Team of Surgeons) Laparoscopic Skills courses utilise hands-on experience with simulators moving to live operating on volunteer patients. It is vital to know that the volunteer patient is not disadvantaged by greater surgical risk. METHODS: This was a case-controlled prospective comparison of patients undergoing both Laparoscopic Cholecystectomy (LC) [n=51] and Laparoscopic Inguinal Hernia (LIH) [n=62] during NUGITS training courses. They are compared with a matched (age, sex and ASA grade) control group LC (n=51) and LIH (n=62) operated on by consultants. The outcome measures were surgical peri-and post-operative complications, post-operative hospital stay, readmission and early recurrence of inguinal hernia (<6 months). RESULTS: In the LC cohort, there was no significant difference in the length of hospital stay (p=0.07) or readmission (p=0.16) in both the groups. The mean operating time was higher in the trainee compared to the control group (p=0.001). There was no difference in the post-operative morbidity or mortality in either group. In LIH cohort, the mean operating time was higher in the trainee compared with the control group. There was no significant difference in post-operative complications (p>0.05) and early post-operative recurrence of hernia (p>0.05). CONCLUSION: The post-operative outcomes of patients undergoing laparoscopic surgery during laparoscopic training courses are similar to consultant-operated patients. Thus, it is acceptable and safe to encourage patients to volunteer for laparoscopic training courses.


Asunto(s)
Competencia Clínica , Educación Médica Continua/normas , Laparoscopía/métodos , Colecistitis/cirugía , Hernia Inguinal/cirugía , Humanos , Estudios Prospectivos , Resultado del Tratamiento
11.
J Laryngol Otol ; 134(3): 205-212, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32122408

RESUMEN

OBJECTIVE: To review the management of temporal bone fractures at a major trauma centre and introduce an evidence-based protocol. METHODS: A review of reports of head computed tomography performed for trauma from January 2012 to July 2018 was conducted. Recorded data fields included: mode of trauma, patient age, associated intracranial injury, mortality, temporal bone fracture pattern, symptoms and intervention. RESULTS: Of 815 temporal bone fracture cases, records for 165 patients met the inclusion criteria; detailed analysis was performed on the records of these patients. CONCLUSION: Temporal bone fractures represent high-energy trauma. Initial management focuses on stabilisation of the patient and treatment of associated intracranial injury. Acute ENT intervention is directed towards the management of facial palsy and cerebrospinal fluid leak, and often requires multidisciplinary team input. The role of nerve conduction assessment for immediate facial palsy is variable across the UK. The administration of high-dose steroids in patients with temporal bone fracture and intracranial injury is not advised. A robust evidence-based approach is introduced for the management of significant ENT complications associated with temporal bone fractures.


Asunto(s)
Práctica Clínica Basada en la Evidencia/métodos , Grupo de Atención al Paciente , Fracturas Craneales/terapia , Hueso Temporal/lesiones , Adulto , Pérdida de Líquido Cefalorraquídeo/etiología , Pérdida de Líquido Cefalorraquídeo/terapia , Niño , Protocolos Clínicos , Parálisis Facial/etiología , Parálisis Facial/terapia , Femenino , Humanos , Masculino , Estudios Retrospectivos , Fracturas Craneales/complicaciones , Fracturas Craneales/diagnóstico por imagen , Hueso Temporal/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Centros Traumatológicos , Reino Unido
12.
Rhinology ; 47(1): 75-8, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19382500

RESUMEN

INTRODUCTION: Primary Ciliary Dyskinesia (PCD) describes a group of inherited disorders which result in functional ciliary defects leading to mucous stasis. Clinical manifestations include otitis media with effusion and chronic rhinosinusitis. Nasal polyposis has previously been thought to be linked to PCD, and current theories of 'polypogenesis' suggest that early and severe polyp formation could be expected among sufferers of this condition. METHODS: Cross-sectional observational review of all children attending the multi-disciplinary clinic at a national tertiary-referral centre for PCD across a 3-month period. Careful examination was undertaken, and the SNOT-20 questionnaire administered. RESULTS: Thirty patients were included. No nasal polyps were found, despite children clearly suffering rhinosinusitis and being debilitated by their symptoms. The rhinologically orientated questions of the SNOT-20 produced the most positive responses; however some other questions were found not to be useful in a paediatric population. CONCLUSIONS: Nasal polyps do not occur in children with PCD, despite the presence of rhinosinusitis. Given that many current theories of polyp pathogenesis hinge on prolongation of proinflammatory stimuli, further investigations are needed into why this should not occur in the situation of chronic mucous stasis which is the hallmark of PCD.


Asunto(s)
Trastornos de la Motilidad Ciliar/complicaciones , Trastornos de la Motilidad Ciliar/patología , Pólipos Nasales/epidemiología , Rinitis/complicaciones , Sinusitis/complicaciones , Adolescente , Niño , Preescolar , Estudios de Cohortes , Estudios Transversales , Femenino , Humanos , Lactante , Masculino , Prevalencia , Calidad de Vida , Estudios Retrospectivos , Rinitis/patología , Sinusitis/patología
13.
Arch Gen Psychiatry ; 45(7): 623-9, 1988 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-3382322

RESUMEN

Experimental neuropsychologic tests were administered to acute patients with schizophrenia and affective psychosis and to normal controls. Patients had remitting illnesses. Tests included memory for recurring digit and block spans (left and right temporohippocampal), digit and block spans (lateralized parietal/frontal), spatial and nonspatial conditional associate learning (frontohippocampal), and oral word fluency to letter-designated categories (frontal) and semantic-designated categories (left-sided). In 81% of schizophrenic patients patterned deficits incompatible with generalized losses of function were disclosed. Patterns were heterogeneous and characterized by (1) the frequency and severity of left temporohippocampal impairment; (2) asymmetric frontohippocampal function such that severity of bilateral impairment was associated with poorer nonspatial learning and superior performance with better nonspatial learning; (3) syndrome relationships predicted by the hemisphere imbalance syndrome model pertaining to positive and negative symptoms and the catatonic syndrome; (4) a generalized deficit independent of temporohippocampal functions; and (5) no relationship between performance and computed tomographic signs or medication. Patients with affective disorders had patterned deficits characterized by bilateral impairments that disclosed a preponderance of deficits in spatial learning and memory; depressives demonstrated impairments in digit span.


Asunto(s)
Trastornos Psicóticos Afectivos/fisiopatología , Lóbulo Frontal/fisiopatología , Hipocampo/fisiopatología , Pruebas Neuropsicológicas , Esquizofrenia/fisiopatología , Psicología del Esquizofrénico , Lóbulo Temporal/fisiopatología , Trastornos Psicóticos Afectivos/psicología , Trastorno Bipolar/fisiopatología , Trastorno Bipolar/psicología , Trastorno Depresivo/fisiopatología , Trastorno Depresivo/psicología , Humanos , Pruebas de Inteligencia , Memoria a Corto Plazo/fisiología
14.
Eur J Prosthodont Restor Dent ; 13(2): 69-74, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16011234

RESUMEN

Ten impressions of a metal implant abutment were made with each of three addition-cured silicone impression materials. Using the technique of co-ordinate metrology, the shoulder region of the abutment and corresponding regions of both impressions and dies made from these impressions were scanned and measured. Comparison of these measurements indicated that the mean dimension measured from the shoulder region for each group of impression materials was significantly different from those taken from the original metal implant abutment. However, when these impressions were cast in a gypsum based die material, none of the measured dimensions taken from the casts were significantly different from those taken from the original metal implant abutment. Thus, any change in measured dimensions occurring during impression making, was compensated for in some way by the casting process.


Asunto(s)
Materiales de Impresión Dental/química , Siliconas/química , Sulfato de Calcio/química , Pilares Dentales , Revestimiento para Colado Dental/química , Técnica de Colado Dental , Implantes Dentales , Técnica de Impresión Dental , Humanos , Procesamiento de Imagen Asistido por Computador , Rayos Láser , Ensayo de Materiales , Polivinilos/química , Elastómeros de Silicona/química , Siloxanos/química , Propiedades de Superficie
15.
J Nucl Med ; 39(8): 1327-34, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9708501

RESUMEN

UNLABELLED: The purpose of this study was to validate an axially distributed blood-tissue exchange model for the quantitation of cardiac presynaptic sympathetic nervous system function that could be applied to PET images. The model accounts for heterogeneity in myocardial blood flow, differences in transport rates of 11C-meta-hydroxyephedrine (mHED) across the capillary endothelium and/or neuronal membranes, the virtual volumes of distribution in the interstitial space and neuron and retention of mHED in the neuronal vesicles. METHODS: Multiple indicator outflow dilution and residue detection methods were used to measure the kinetics of radiolabeled intravascular space and interstitial space markers and 11C-mHED in isolated perfused rat heart at baseline and during norepinephrine neuronal transporter blockade with desipramine (DMI). The outflow dilution and residue detection data were modeled with a multiple pathway, four-region, axially distributed model of blood-tissue exchange describing flow in the capillary and exchange between regions using permeability-surface area products with units of clearance of milliliters per minute per gram. Meta-hydroxyephedrine may enter the nerve terminal via membrane transport, where it may be sequestered by first-order unidirectional uptake within vesicles. Release of mHED from the vesicles is modeled via exchange with the interstitial space. RESULTS: After intracoronary injection, mHED transport across the capillary endothelium and in the interstitial space closely followed that of sucrose. Subsequently, mHED was retained in the heart, whereas sucrose washed out rapidly. With DMI the outflow dilution curves more closely resembled those of sucrose. Model parameters reflecting capillary-interstitial kinetics and volumes of distribution were unchanged by DMI, whereas parameters reflecting the neuronal transporter process and volumes of distribution in the nerve terminal and vesicular sequestration were markedly decreased by DMI. Application of the model to a pilot set of canine PET images of mHED suggests the feasibility of this approach. CONCLUSION: Meta-hydroxyephedrine kinetics in the heart can be quantitated using an axially distributed, blood-tissue exchange model that accounts for heterogeneity of flow, reflects changes in neuronal function and is applicable to PET images.


Asunto(s)
Radioisótopos de Carbono , Efedrina/análogos & derivados , Corazón/diagnóstico por imagen , Sistema Nervioso Simpático/diagnóstico por imagen , Tomografía Computarizada de Emisión , Inhibidores de Captación Adrenérgica , Animales , Permeabilidad Capilar/fisiología , Medios de Contraste , Circulación Coronaria/fisiología , Desipramina , Perros , Estudios de Factibilidad , Corazón/inervación , Masculino , Modelos Cardiovasculares , Ratas , Ratas Sprague-Dawley , Sistema Nervioso Simpático/fisiología
16.
Biochem Pharmacol ; 53(7): 943-50, 1997 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-9174107

RESUMEN

The triazine antifolates, cycloguanil and 4,6-diamino-1,2-dihydro-2,2-dimethyl-1-[(2,4,5-trichlorophenoxy)propy loxy]-1,3,5-triazine hydrobromide (WR99210), and their parent biguanide compounds, proguanil and N-[3-(2,4,5-trichlorophenoxy)propyloxy]-n-(1-methylethyl)-imido dicarbonimidic-diamine hydrochloride (PS-15), were tested in combination with a series of antimalarial drugs for synergism against Plasmodium falciparum growing in erythrocytic culture. Four synergistic combinations were found: cycloguanil dapsone, WR99210-dapsone, proguanil-atovaquone, and PS-15-atovaquone. Cycloguanil-dapsone or WR99210-dapsone had a profound suppressive effect on the concentration of dTTP in parasites while that of dATP increased. Depletion of dTTP is consistent with cycloguanil or WR99210 inhibiting dihydrofolate reductase and dapsone inhibiting dihydropteroate synthase. For the combinations proguanil-atovaquone and PS-15-atovaquone, the levels of nucleoside triphosphates (NTPs) and dNTPs were generally suppressed, suggesting that inhibition is not through nucleotide pathways but probably through another metabolic mechanism(s). Combinations of two synergistic pairs of antimalarial drugs, (proguanil-atovaquone)-(cycloguanil-dapsone) and (PS-15-atovaquone)-(WR99210-dapsone), were tested, and it was found that NTPs and dNTPs decreased much more than for a single synergistic combination. Dual synergistic combinations could play an important role in the therapy of multidrug-resistant malaria, just as combination chemotherapy is used to treat cancer.


Asunto(s)
Antimaláricos/farmacología , Dapsona/farmacología , Antagonistas del Ácido Fólico/farmacología , Naftoquinonas/farmacología , Plasmodium falciparum/efectos de los fármacos , Adenosina Trifosfato/análisis , Animales , Atovacuona , Células Cultivadas , Citidina Trifosfato/análisis , Combinación de Medicamentos , Farmacorresistencia Microbiana , Sinergismo Farmacológico , Eritrocitos/parasitología , Guanosina Trifosfato/análisis , Humanos , Plasmodium falciparum/genética , Plasmodium falciparum/metabolismo , Uridina Trifosfato/análisis
17.
Br J Surg ; 87(3): 362-73, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10718814

RESUMEN

AIMS: The aim of ipsilateral portal vein embolization is to induce hypertrophy of normal tissue when resection of a cancerous portion of the liver is contraindicated only by the volume of liver that would remain following surgery. This study reports its use in primary and metastatic liver tumours. METHODS: Eight patients with inoperable liver tumours (three women and five men of median age 68. 5 years; three colorectal hepatic metastases, two cholangiocarcinomas and three hepatocellular cancers) were selected for portal vein embolization. Selected portal branches were occluded distally with microbeads and proximally with coils. Liver volumes were determined by magnetic resonance imaging before embolization and again before surgery, 6-8 weeks later. RESULTS: Embolization was performed successfully in seven patients by the percutaneous-transhepatic route; one further patient required an open cannulation of the inferior mesenteric vein. Management was altered in six patients, who proceeded to 'curative' surgery. The projected remaining (predominantly left lobe) liver volumes increased significantly from a median of 350 to 550 ml (P < 0.05, Wilcoxon matched pairs test). Two patients had disease progression such that surgery was no longer indicated. One patient, whose disease progressed, had the left portal branch occluded unintentionally by a misplaced coil that was successfully retrieved, although the left portal branch remained occluded. CONCLUSIONS: Portal vein embolization produced significant hypertrophy of the normal liver and extended the option of 'curative' surgery to six of the eight patients in whom it was attempted. It appears to be equally effective for primary and metastatic liver tumours in selected patients.

18.
Obes Surg ; 8(4): 429-33, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9731678

RESUMEN

BACKGROUND: The effects of surgery for morbid obesity on the function of the upper gastrointestinal (GI) tract are of interest to bariatric surgeons. This study was undertaken to determine any changes in esophageal function, following vertical banded gastroplasty (VBG) in morbidly obese patients, as detected by esophageal scintigraphy. METHODS: Ten consecutive morbidly obese patients (six female and four male) underwent preoperative esophageal scintigraphy and upper GI endoscopy. These investigations were repeated 12 months after VBG to coincide with expected appreciable weight reduction. The results were tabulated together with body mass indices, crude weights and percentage excess weight lost. RESULTS: Before VBG one patient gave a history of mild heartburn, one had mild dyspepsia and the remaining eight patients had no GI symptoms. No patient had a hiatus hernia or endoscopic evidence of reflux esophagitis. Preoperatively all patients had abnormal scintiscans. The abnormalities were esophageal retention (all) and intraesophageal reflux (five out of 10 patients). Gastroesophageal reflux was not identified in any patient. Postoperatively scintiscans were normal or improved in six out of 10 patients and unchanged in four out of 10 patients. In three patients the scans were normal and three showed overall improvement in esophageal function, although in one of these latter patients gastroesophageal reflux was observed. CONCLUSIONS: In this series of morbidly obese patients, esophageal function as assessed by scintigraphy was abnormal. Following VBG it improved in six out of 10 patients and was unchanged in four out of 10. However, in one patient, who had shown an overall improvement in esophageal function, gastroesophageal reflux was demonstrated when it had not been seen preoperatively. This was asymptomatic. Thus, adverse changes in esophageal function after VBG were uncommon.


Asunto(s)
Esófago/diagnóstico por imagen , Esófago/fisiopatología , Gastroplastia , Obesidad Mórbida/fisiopatología , Adolescente , Adulto , Niño , Trastornos de la Motilidad Esofágica/diagnóstico por imagen , Trastornos de la Motilidad Esofágica/etiología , Femenino , Gastroplastia/métodos , Humanos , Masculino , Persona de Mediana Edad , Obesidad Mórbida/cirugía , Complicaciones Posoperatorias , Cintigrafía
19.
Colorectal Dis ; 4(4): 240-245, 2002 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12780593

RESUMEN

OBJECTIVE: Untreated malignant large bowel obstruction is rapidly fatal. Short-term palliation of symptoms can be achieved by formation of a stoma in those patients for whom resection surgery is inappropriate. In the final months of life, a stoma represents a significant burden for both patients and carers. Palliative endoluminal stenting may therefore be an attractive alternative option for this poor prognosis group. In this paper, we examine our experience of palliative endoluminal colonic stenting. PATIENTS: Twenty patients, 11 males and 9 females of median age 81 years were referred for stenting. All had left sided colonic cancers. Ten patients had confirmed metastases on presentation, four had fixed rectal cancers and the remainder had severe comorbidity limiting surgical options. Stents were placed endoscopically using a radiologically controlled 'stent over wire' technique. RESULTS: Stenting successfully relieved the obstruction in 18 of the 20 patients attempted. In one patient the stricture could not be negotiated and the procedure was abandoned. Eleven patients have died of their disease, their median duration of palliation was 50 days (3-152 days). The rest of the patients continue in follow-up and have had 80 days median palliation (14-257 days). One stent-related complication has been observed in a patient who suffered anal pain due to fracture and migration of part of a stent into the low rectum. This complication occurred after 250 days and the distal stent fragment was removed with further symptom relief. CONCLUSION: Carefully selected patients benefit from colonic endoluminal stenting with relief of obstructive symptoms. They may be spared the potential problems associated with palliative stoma formation.

20.
Br Dent J ; 197(4): 205-9, 2004 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-15375414

RESUMEN

OBJECTIVE: To explore how dental undergraduates with different levels of emotional intelligence (EI) cope with stress. DESIGN: Qualitative unstructured depth interviews. SETTING: A dental teaching hospital in the UK, 2002. SUBJECTS AND METHODS: Subjects selected from the undergraduate population of a 5-year dental degree course. A questionnaire survey was carried out to determine the EI scores of the subjects. In each year of study, subjects were divided into low and high EI groups at the median score. From each EI group in each year, one male and one female subject were recruited. DATA COLLECTION: Unstructured face-to-face interviews. DATA ANALYSIS: Transcribing, sifting, indexing and charting data according to key themes. RESULTS: 10 males and 10 females with low and high EI, representing all 5 years of study were interviewed. The experience of stress, expressed in emotional terms, ranged from anger and frustration to hatred. Four sets of coping strategies, adopted at varying degrees according to EI, were identified. High EI students were more likely to adopt reflection and appraisal, social and interpersonal, and organisation and time-management skills. Low EI students were more likely to engage in health-damaging behaviours. CONCLUSIONS: Future research needs to establish whether the enhancement of EI in dental students would lead to improved stress-coping, and better physical and psychological health.


Asunto(s)
Adaptación Psicológica , Emociones , Inteligencia , Estrés Psicológico/psicología , Estudiantes de Odontología/psicología , Ira , Actitud , Emoción Expresada , Femenino , Frustación , Odio , Conductas Relacionadas con la Salud , Humanos , Relaciones Interpersonales , Entrevistas como Asunto , Masculino , Autoevaluación (Psicología) , Conducta Social , Administración del Tiempo
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