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1.
Lab Invest ; 101(8): 1098-1109, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33859335

RESUMEN

Steatosis is the most important prognostic histologic feature in the setting of liver procurement. The currently utilized diagnostic methods, including gross evaluation and frozen section examination, have important shortcomings. Novel techniques that offer advantages over the current tools could be of significant practical utility. The aim of this study is to evaluate the accuracy of surface color spectrophotometry in the quantitative assessment of steatosis in a murine model of fatty liver. C57BL/6 mice were divided into a control group receiving normal chow (n = 19), and two steatosis groups receiving high-fat diets for up to 20 weeks-mild steatosis (n = 10) and moderate-to-severe steatosis (n = 19). Mouse liver surfaces were scanned with a hand-held spectrophotometer (CM-600D; Konica-Minolta, Osaka, Japan). Spectral reflectance data and color space values (L*a*b*, XYZ, L*c*h*, RBG, and CMYK) were correlated with histopathologic steatosis evaluation by visual estimate, digital image analysis (DIA), as well as biochemical tissue triglyceride measurement. Spectral reflectance and most color space values were very strongly correlated with histologic assessment of total steatosis, with the best predictor being % reflectance at 700 nm (r = 0.91 [0.88-0.94] for visual assessment, r = 0.92 [0.88-0.95] for DIA of H&E slides, r = 0.92 [0.87-0.95] for DIA of oil-red-O stains, and r = 0.78 [0.63-0.87] for biochemical tissue triglyceride measurement, p < 0.0001 for all). Several spectrophotometric parameters were also independently predictive of large droplet steatosis. In conclusion, hepatic steatosis can accurately be assessed using a portable, commercially available hand-held spectrophotometer device. If similarly accurate in human livers, this technique could be utilized as a point-of-care tool for the quantitation of steatosis, which may be especially valuable in assessing livers during deceased donor organ procurement.


Asunto(s)
Hígado Graso , Hígado , Espectrofotometría/métodos , Animales , Modelos Animales de Enfermedad , Hígado Graso/diagnóstico por imagen , Hígado Graso/patología , Técnicas Histológicas , Hígado/diagnóstico por imagen , Hígado/patología , Trasplante de Hígado , Masculino , Ratones , Ratones Endogámicos C57BL , Espectrofotometría/instrumentación
2.
J Intellect Disabil Res ; 62(2): 150-155, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28980362

RESUMEN

BACKGROUND: The Strengths and Difficulties Questionnaire (SDQ) is widely used to measure emotional and behavioural problems in typically developing young people, although there is some evidence that it may also be suitable for children with intellectual disability (ID). The Developmental Behaviour Checklist - Parent version (DBC-P) is a measure of emotional and behavioural problems that was specifically designed for children and adolescents with an ID. The DBC-P cut-off has high agreement with clinical diagnosis. The aim of this study was to estimate the relationship between DBC-P and SDQ scores in a sample of children with ID. METHOD: Parents of 83 young people with ID aged 4-17 years completed the parent versions of the SDQ and the DBC-P. We evaluated the concurrent validity of the SDQ and DBC-P total scores, and the agreement between the DBC-P cut-off and the SDQ cut-offs for 'borderline' and 'abnormal' behaviour. RESULTS: The SDQ total difficulties score correlated well with the DBC-P total behaviour problem score. Agreement between the SDQ borderline cut-off and the DBC-P cut-off for abnormality was high (83%), but was lower for the SDQ abnormal cut-off (75%). Positive agreement between the DBC-P and the SDQ borderline cut-off was also high, with the SDQ borderline cut-off identifying 86% of those who met the DBC-P criterion. Negative agreement was weaker, with the SDQ borderline cut-off identifying only 79% of the participants who did not meet the DBC-P cut-off. CONCLUSION: The SDQ borderline cut-off has some validity as a measure of overall levels of behavioural and emotional problems in young people with ID, and may be useful in epidemiological studies that include participants with and without ID. However, where it is important to focus on behavioural profiles in children with ID, a specialised ID instrument with established psychometric properties, such as the DBC-P, may provide more reliable and valid information.


Asunto(s)
Escala de Evaluación de la Conducta/normas , Síntomas Conductuales/diagnóstico , Trastornos de la Conducta Infantil/diagnóstico , Discapacidad Intelectual/diagnóstico , Escalas de Valoración Psiquiátrica/normas , Adolescente , Síntomas Conductuales/etiología , Lista de Verificación , Niño , Trastornos de la Conducta Infantil/etiología , Preescolar , Femenino , Humanos , Discapacidad Intelectual/complicaciones , Masculino , Problema de Conducta , Reproducibilidad de los Resultados
3.
J Intellect Disabil Res ; 61(1): 75-82, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27868264

RESUMEN

BACKGROUND: Recent research suggests that around 16% to 18% of children with Down syndrome (DS) also meet diagnostic criteria for autism spectrum disorder (ASD). However, there are indications that profiles of autism symptoms in this group may vary from those typically described in children with ASD. METHOD: Rates of autism symptoms and emotional and behavioural problems among children with DS who screened positive for ASD on the Social Communication Questionnaire (SCQ) (n = 183) were compared with a group of children with clinical diagnoses of ASD (n = 189) attending specialist schools in the UK. Groups were matched for age and approximate language level (use of phrase speech). RESULTS: Profiles of autistic symptoms in the two groups were generally similar, but children with DS meeting ASD cut-off on the SCQ tended to show fewer problems in reciprocal social interaction than those in the ASD group. They also showed slightly lower rates of emotional and peer-related problems. The results mostly confirm findings from a previous study in which the original validation sample for the SCQ was used as a comparison group. CONCLUSION: Findings suggest that children with DS who meet screening criteria for ASD show similar profiles of communication and repetitive behaviours to those typically described in autism. However, they tend to have relatively milder social difficulties. It is important that clinicians are aware of this difference if children with DS and ASD are to be correctly diagnosed and eligible for specialist intervention and education services.


Asunto(s)
Trastorno del Espectro Autista/epidemiología , Trastorno del Espectro Autista/fisiopatología , Síndrome de Down/epidemiología , Adolescente , Adulto , Niño , Preescolar , Comorbilidad , Educación Especial/estadística & datos numéricos , Femenino , Humanos , Masculino , Reino Unido/epidemiología , Adulto Joven
4.
J Intellect Disabil Res ; 61(6): 594-603, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-27862512

RESUMEN

BACKGROUND: Recent studies have indicated an increased risk of autism, behavioural and emotional problems and attention-deficit/hyperactivity disorder in individuals with Down syndrome. METHOD: In a large-scale survey-based study, we examined the rates of these problems and their relationship to age and gender, in a sample of 674 individuals (4-18 years) with Down syndrome. The relationship with IQ level was also explored in a subsample (n = 175). The Strengths and Difficulties Questionnaire and the Social Communication Questionnaire were used to assess behavioural and emotional problems and autism traits. RESULTS: On the Strengths and Difficulties Questionnaire, peer problems were the most frequently reported difficulty (48% > cut-off), followed by hyperactivity/inattention (34% > cut-off). On the Social Communication Questionnaire, 37% scored at or above cut-off (≥15) for autism spectrum disorder; 17% were at or above the suggested cut-off (≥22) for autism. Little association between age and behavioural or emotional problems or with severity of autistic symptomatology was found. However, peer problems were more common in adolescents than in junior school children (P < 0.001); Hyperactivity/inattention was less prevalent among adolescents (P < 0.001). CONCLUSIONS: High rates of autistic features, emotional and behavioural problems are documented. These problems are related to age, gender and degree of intellectual disability.


Asunto(s)
Síntomas Afectivos/fisiopatología , Trastorno del Espectro Autista/fisiopatología , Síndrome de Down/fisiopatología , Problema de Conducta , Conducta Social , Adolescente , Síntomas Afectivos/epidemiología , Trastorno del Espectro Autista/epidemiología , Niño , Preescolar , Comorbilidad , Síndrome de Down/epidemiología , Femenino , Humanos , Masculino , Noruega/epidemiología , Reino Unido/epidemiología
5.
Am J Med Genet A ; 164A(5): 1213-7, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24610892

RESUMEN

Yunis-Varon syndrome is a rare autosomal recessive condition initially characterized by specific skeletal and ectodermal abnormalities, and a poor prognosis, due to neurological and cardiovascular involvement. We describe the cardiovascular and endocrine complications in a 26-year-old man who had been reported previously, adding dilated cardiomyopathy to the clinical features consistent with Yunis-Varon syndrome. Short stature, successfully treated with growth hormone, and hypertension secondary to bilateral renal artery stenosis expand the phenotype.


Asunto(s)
Displasia Cleidocraneal/diagnóstico , Displasia Ectodérmica/diagnóstico , Deformidades Congénitas de las Extremidades/diagnóstico , Micrognatismo/diagnóstico , Anomalías Múltiples/diagnóstico , Anomalías Múltiples/genética , Anomalías Cardiovasculares/diagnóstico , Anomalías Cardiovasculares/genética , Niño , Preescolar , Displasia Cleidocraneal/genética , Diagnóstico Diferencial , Displasia Ectodérmica/genética , Electrocardiografía , Enfermedades del Sistema Endocrino/congénito , Enfermedades del Sistema Endocrino/diagnóstico , Gráficos de Crecimiento , Humanos , Deformidades Congénitas de las Extremidades/genética , Masculino , Micrognatismo/genética , Fenotipo , Radiografía Torácica
6.
Nat Med ; 2(6): 703-7, 1996 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8640566

RESUMEN

Nerve growth factor (NGF) is trophic to sensory and sympathetic fibers. In animal models, NGF is depleted in diabetic nerves and NGF deprivation produces hypoalgesia. Exogenous NGF can reverse some of the pathological changes in diabetic nerves and NGF excess leads to hyperalgesia. We have quantified sensory and autonomic function in early diabetic polyneuropathy and correlated changes with levels of NGF and neuropeptides in affected skin. We describe an early length-dependent dysfunction of sensory small-diameter fibers, prior to dysfunction of sympathetic fibers, with depletion of skin NGF and the sensory neuropeptide substance P. We describe a significant correlation between NGF depletion and decreased skin axon-reflex vasodilation, mediated by small sensory fibers partly via substance P release. Immunostaining shows depletion of NGF in keratinocytes in diabetic skin. We propose that a decrease in endogenous skin-derived NGF influences the presentation of diabetic polyneuropathy, although metabolic or vascular abnormalities may be the cause of the neuropathy. As loss of nociception and axon-reflex vasodilation contribute to diabetic foot ulceration, early and prolonged NGF treatment at an appropriate dose may provide rational prophylaxis for this condition.


Asunto(s)
Neuropatías Diabéticas/metabolismo , Neuropatías Diabéticas/patología , Factores de Crecimiento Nervioso/análisis , Factores de Crecimiento Nervioso/metabolismo , Adolescente , Adulto , Axones/patología , Axones/fisiología , Femenino , Pie/fisiología , Humanos , Masculino , Reflejo , Sensación , Piel/química , Sustancia P/análisis
7.
Prehosp Disaster Med ; 25(2): 188-90, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20468002

RESUMEN

INTRODUCTION: During deployment following Hurricane Ike in September 2008, bites from domestic animals were among the top three trauma complaints seen at the National Disaster Medical System (NDMS) Disaster Medical Assistance Team (DMAT) base of operations. PROBLEM: Unlike previous reports of frightened, misplaced dogs and cats biting strangers and rescue workers, there was an increase in bites associated with presumed non-rabid pets who were known to the bite victim. METHODS: This was an observational sampling of all patients presenting for medical care during deployment to the AL-3 DMAT base of operations in Webster, Texas, following Hurricane Ike. Findings were compared with unofficial local norms and observations from the literature. RESULTS: Of the people with animal bites presenting to the field hospital, dog bites accounted for 55%, cat bites, 40%, and snake bites, 5%. Most of the wounds required suturing and were not simple punctures. Most bites (70%) involved the hand(s). Some patients presented >24 hours after the bite, and already had developed cellulitis. One patient required transfer and inpatient admission for intravenous antibiotics and debridement of a hand injury with spread into the metacarpophalangeal space. CONCLUSIONS: Most of the bites were severe and occurred within the first 72 hours after the hurricane, and waned steadily over the following weeks to baseline levels. No animal bites caused by misplaced dogs and cats biting strangers were seen. There was an increase in bites associated with domesticated pets known to the bite victim. The current NDMS cache is stocked adequately to care for most wounds caused by animal bites. However post-exposure rabies treatment is not part of the routine medications offered. For future disaster preparedness training, pet owners should be aware of the increased potential for dog and cat bites.


Asunto(s)
Mordeduras y Picaduras/epidemiología , Gatos , Tormentas Ciclónicas , Perros , Incidentes con Víctimas en Masa , Animales , Mordeduras y Picaduras/terapia , Humanos , Incidencia , Guías de Práctica Clínica como Asunto , Mordeduras de Serpientes/epidemiología , Mordeduras de Serpientes/terapia , Texas/epidemiología
8.
Prehosp Disaster Med ; 25(1): 87-91, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20405469

RESUMEN

OBJECTIVE: The impact of the use of mask continuous positive airway pressure (CPAP) on patients with acute respiratory distress in the prehospital, rural setting has not been defined. The goal was to test the use of CPAP using the Respironics WhisperFlow CPAP in patients presenting with acute respiratory distress. This was a collaborative evaluation of CPAP involving a rural EMS agency and the regional medical center. Patient outcomes including the overall rate of intubation-both in the field and in the emergency department (ED), and length of stay in the hospital and Intensive Care Unit (ICU) were tracked. METHODS: The study was an eight-month, crossover, observational, non-blinded study. RESULTS: During the four months of baseline data collection, 7.9% of patients presenting with respiratory distress were intubated within the first 48 hours of care. Their average ICU length of stay was 8.0 days. During the four months of data collection when CPAP was available in the prehospital setting, intubation was not required for any patients in the field or in the ED. Admissions to the ICU decreased. Those patients admitted to the ICU, the average ICU length of stay deceased to 4.3 days. CONCLUSIONS: The use of the CPAP in the prehospital setting is beneficial for patients in acute respiratory distress.


Asunto(s)
Presión de las Vías Aéreas Positiva Contínua , Servicios Médicos de Urgencia , Síndrome de Dificultad Respiratoria/terapia , Apoyo Vital Cardíaco Avanzado , Servicio de Urgencia en Hospital , Indicadores de Salud , Humanos , Unidades de Cuidados Intensivos/estadística & datos numéricos , Tiempo de Internación/estadística & datos numéricos , Estados Unidos
9.
J Clin Invest ; 103(9): 1243-52, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-10225967

RESUMEN

Engagement of the B7 family of molecules on antigen-presenting cells with their T cell-associated ligands, CD28 and CD152 (cytotoxic T lymphocyte-associated antigen-4 [CTLA-4]), provides a pivotal costimulatory signal in T-cell activation. We investigated the role of the CD28/CD152 pathway in psoriasis in a 26-week, phase I, open-label dose-escalation study. The importance of this pathway in the generation of humoral immune responses to T cell-dependent neoantigens, bacteriophage phiX174 and keyhole limpet hemocyanin, was also evaluated. Forty-three patients with stable psoriasis vulgaris received 4 infusions of the soluble chimeric protein CTLA4Ig (BMS-188667). Forty-six percent of all study patients achieved a 50% or greater sustained improvement in clinical disease activity, with progressively greater effects observed in the highest-dosing cohorts. Improvement in these patients was associated with quantitative reduction in epidermal hyperplasia, which correlated with quantitative reduction in skin-infiltrating T cells. No markedly increased rate of intralesional T-cell apoptosis was identified, suggesting that the decreased number of lesional T cells was probably likely attributable to an inhibition of T-cell proliferation, T-cell recruitment, and/or apoptosis of antigen-specific T cells at extralesional sites. Altered antibody responses to T cell-dependent neoantigens were observed, but immunologic tolerance to these antigens was not demonstrated. This study illustrates the importance of the CD28/CD152 pathway in the pathogenesis of psoriasis and suggests a potential therapeutic use for this novel immunomodulatory approach in an array of T cell-mediated diseases.


Asunto(s)
Antígenos de Diferenciación/uso terapéutico , Inmunoconjugados , Activación de Linfocitos , Psoriasis/terapia , Linfocitos T/inmunología , Abatacept , Adulto , Formación de Anticuerpos , Antígenos CD , Antígenos de Diferenciación/sangre , Antígeno CTLA-4 , Estudios de Cohortes , Relación Dosis-Respuesta Inmunológica , Femenino , Humanos , Inmunohistoquímica , Queratinocitos/metabolismo , Queratinocitos/patología , Masculino , Persona de Mediana Edad , Psoriasis/inmunología , Resultado del Tratamiento
10.
Rev Biol Trop ; 53 Suppl 1: 61-6, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-17465145

RESUMEN

The purpose of this study was to record the species of Antipatharia on Jamaican reefs and to carry out limited studies on densities and sizes of the common species. In addition, a cliff face created by dredging in 2002 provided the opportunity to study growth of newly settled colonies. Observations since 1998 and measurements since 2001 were made using SCUBA at depths down to 35 m. Seven species of Antipatharia were observed on steep coral reef escarpments below 25 m depth. The commonest species was the unbranched "wire coral" Stichopathes lutkeni. Other common species included the fan-shaped black corals Antipathes atlantica and A. gracilis. Frequently encountered species included commercially important A. caribbeana and a species with an unusual, scrambling growth form, A. rubusiformis. The other major commercial species in the Caribbean, Plumapathes pennacea, and a cave-dwelling species, A. umbratica, were rarely observed. Greatest black coral abundance occurred on steep slopes of hard substrata in low light intensity but exposed to the long-shore current. Combined densities of the commoner Antipatharia at 30 m deep at Rio Bueno on the north coast, ranged from 0.1 to 2.5 m(-2) (eleven 10 m x 1 m belt transects, 1-25 colonies per transect, 68 colonies in total). Forty-six of the 68 colonies were S. lutkeni, while nearby at Discovery Bay at 30-35 m, 55 out of 59 colonies were S. lutkeni. There was a significant difference between the mean length of colonies in these two populations of S. lutkeni (100 cm and 80 cm, respectively), probably relating to habitat. A third population of S. lukeni growing at 15-20 m deep on the recently dredged cliff had a much smaller mean length of 36.6 cm (n= 27). The largest individual measured 83 cm long, indicating a minimum growth rate of the unbranched corallum of 2.1 mm per day.


Asunto(s)
Antozoos/crecimiento & desarrollo , Ecosistema , Análisis de Varianza , Animales , Antozoos/clasificación , Biodiversidad , Biometría , Tamaño Corporal , Jamaica , Densidad de Población , Dinámica Poblacional , Especificidad de la Especie
11.
J Steroid Biochem Mol Biol ; 148: 256-60, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25448734

RESUMEN

There have been observational reports that maternal vitamin D status at baseline and not closest to delivery is a better predictor of pregnancy outcomes, suggesting that a cascade of events is set into motion that is not modifiable by vitamin D supplementation during later pregnancy. To address this issue, in this exploratory post-hoc analysis using correlation and logistic regression, we sought to measure the strength of the association between serum 25(OH)D concentrations at 3 timepoints during pregnancy: baseline, 1st trimester (<16 weeks); 2nd trimester (16-26 weeks); and 3rd trimester (≥27 weeks) and preterm birth. It was hypothesized that the 25(OH)D value closest to delivery would be most significantly associated with preterm birth. To accomplish this objective, the datasets from NICHD (n=333) and Thrasher Research Fund (n=154) vitamin D supplementation pregnancy studies were combined. The results of this analysis were that 25(OH)D values closer to delivery were more strongly correlated with gestational age at delivery than earlier values: 1st trimester: r=0.11 (p=0.02); 2nd trimester: r=0.08 (p=0.09); and 3rd trimester: r=0.15 (p=0.001). When logistic regression was performed with preterm birth (<37 weeks) as the outcome and 25(OH)D quartiles as the predictor variable, adjusting for study and participant race/ethnicity, as with the correlation analysis, the measurements closer to delivery were more significantly associated and had a higher magnitude of effect. That is, at baseline, those who had serum concentrations <50nmol/L (20ng/mL) had 3.3 times of odds of a preterm birth compared to those with serum concentrations ≥100nmol/L (40ng/mL; p=0.27). At 2nd trimester, the odds were 2.0 fold (p=0.21) and at the end of pregnancy, the odds were 3.8 fold (p=0.01). The major findings from this exploratory analysis were: (1) maternal vitamin D status closest to delivery date was more significantly associated with preterm birth, suggesting that later intervention as a rescue treatment may positively impact the risk of preterm delivery, and (2) a serum concentration of 100nmol/L (40ng/mL) in the 3rd trimester was associated with a 47% reduction in preterm births. This article is part of a Special Issue entitled '17th Vitamin D Workshop'.


Asunto(s)
Complicaciones del Embarazo/prevención & control , Nacimiento Prematuro/prevención & control , Deficiencia de Vitamina D/tratamiento farmacológico , Vitamina D/sangre , Suplementos Dietéticos , Femenino , Humanos , Embarazo , Resultado del Embarazo , Factores de Riesgo , Vitamina D/administración & dosificación , Deficiencia de Vitamina D/sangre
12.
Biochem Soc Symp ; 61: 259-71, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-8660400

RESUMEN

New atherosclerosis causative factors and preventive modalities have been identified. Atherogenic factors include lipid oxidation products, such as cholesterol oxidation products, malonaldehyde and other aldehydes; trans-fatty acids; some saturated fatty acids (lauric, myristic and possibly palmitic acids); and myristic acid plus cholesterol. Lipid oxidation products are well suited to induce arterial damage, based on their known cytotoxic effects; evidence also indicates the possibility of plaque promotion and stimulation of thrombogenesis. Anti-atherogenic factors include antioxidants, fish oils and other polyunsaturates (if protected from oxidation), fibre and trace minerals such as copper, manganese, selenium and zinc. Iron is unique, being considered as both a potential promoter of atherosclerosis (component of ferritin, conceivably inducing lipid oxidation) and a possible anti-atherogenic component (of antioxidant enzyme catalase). It is apparent that an entire new series of research challenges has been uncovered.


Asunto(s)
Antioxidantes/farmacología , Arteriosclerosis/etiología , Enfermedad Coronaria/etiología , Dieta Aterogénica , Grasas de la Dieta/farmacología , Arteriosclerosis/prevención & control , Colesterol/metabolismo , Enfermedad Coronaria/prevención & control , Humanos , Oxidación-Reducción
13.
Neurology ; 41(3): 450-2, 1991 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2006019

RESUMEN

Disinhibited, exaggerated responses to objects and environmental cues (utilization behavior) occur predominantly with frontal lobe damage. We report a striking example associated with paramedian thalamic infarction suggesting a thalamofrontal component to environmental interactions that require inhibition, self-monitoring, and cognitive flexibility.


Asunto(s)
Conducta/fisiología , Infarto Cerebral/psicología , Lóbulo Frontal/fisiopatología , Enfermedades Talámicas/psicología , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Examen Neurológico , Pruebas Neuropsicológicas , Enfermedades Talámicas/diagnóstico por imagen , Enfermedades Talámicas/fisiopatología , Tomografía Computarizada por Rayos X
14.
J Immunol Methods ; 105(2): 171-7, 1987 Dec 24.
Artículo en Inglés | MEDLINE | ID: mdl-3693905

RESUMEN

Lymphocyte 51Cr release and [3H]thymidine uptake assays were evaluated with respect to measurement of sample radioactivity using the flat-bed scintillation counter. 51Cr lysates were spotted onto a glass fibre filter sheet while [3H]thymidine-labelled cells were filtered onto a similar sheet using a cell harvester. The 96 samples were rapidly processed for counting, without removal of individual sample areas. Either form of preparation showed good linearity of count rate with the quantity of material on the filter. Reproducibility was good; the coefficient of variation for 96 samples being within 5%. The low background and high efficiency of this counter results in increased assay sensitivity and allows considerable economies in materials to be made. A commercial version of the counter has six counting heads permitting a high rate of sample throughput.


Asunto(s)
Pruebas Inmunológicas de Citotoxicidad , Activación de Linfocitos , Conteo por Cintilación/instrumentación , Partículas beta , Radioisótopos de Cromo , Rayos gamma , Humanos , Tritio
15.
Pediatrics ; 88(1): 145-50, 1991 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2057250

RESUMEN

These are case reports of two children with structurally normal hearts and with normal coronary arteries, who survived myocardial infarction in the early neonatal period. They are only the third and fourth reported survivors of neonatal myocardial infarction and the first in which hypercholesterolemia is postulated to have played an important role. The most likely cause of the myocardial infarction was thrombosis or thromboembolism. Changes in hemostatic function associated with hypercholesterolemia may be relevant.


Asunto(s)
Infarto del Miocardio/diagnóstico , Angiografía Coronaria , Ecocardiografía , Electrocardiografía , Femenino , Corazón/diagnóstico por imagen , Humanos , Hiperlipoproteinemia Tipo II/complicaciones , Hiperlipoproteinemia Tipo II/diagnóstico , Recién Nacido , Masculino , Infarto del Miocardio/etiología , Trombosis/complicaciones , Trombosis/diagnóstico
16.
J Nucl Med ; 17(9): 836-9, 1976 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-956898

RESUMEN

These phantom studies and computer calculations provide a direct means of estimating the radiation dose to the embryo resulting from the administration of a radiopharmaceutical to the mother during organogenesis. The specific absorbed fractions to the embryo from 19 source organs were computed for 12 monoenergetic photon energies. Tables of absorbed dose per unit cumulated activity, S, for the embryo as a target organ have been assembled for 99mTc, 111In, 113mIn, 123I, 131I, and 133Xe. In addition, the dose to the embryo was calculated for several of the radiopharmaceuticals for which the MIRD Committee has published dose estimate reports.


Asunto(s)
Embrión de Mamíferos , Dosis de Radiación , Radioisótopos , Femenino , Humanos , Radioisótopos de Yodo , Modelos Estructurales , Embarazo , Tecnecio
17.
Biochem Pharmacol ; 40(8): 1747-56, 1990 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-2242011

RESUMEN

The profile of nicotine metabolites produced by freshly isolated hepatocytes from rats, hamsters, guinea pigs, mice and humans was investigated after a 30-min exposure to nicotine ([2-14C]pyrrolidine). Large species differences occurred in the extent of nicotine metabolism; these ranged from 95% metabolism in guinea pig hepatocytes to only 30% metabolism in human and rat hepatocytes. The spectrum of metabolites formed also varied widely in different species. In hepatocytes from obese human subjects, nicotine was metabolized most extensively in smokers, least in nonsmokers, and to an intermediate degree in exsmokers, suggesting that cigarette smoking enhances the rate of nicotine metabolism. Pretreatment of all nonhuman species studied with phenobarbital and beta-naphthoflavone and with Aroclor in rats produced distinctive inductive patterns. Phenobarbital pretreatment of nonsmokers for 2 days prior to liver biopsy doubled the extent of nicotine conversion to cotinine by their hepatocytes. Rat and hamster hepatocytes exhibited sex and stereoselectivity differences in nicotine metabolism. Collectively, these studies indicate that hepatocytes offer some advantages over in vivo systems in investigating certain aspects of nicotine metabolism.


Asunto(s)
Hígado/metabolismo , Nicotina/metabolismo , Animales , Células Cultivadas/metabolismo , Cromatografía Líquida de Alta Presión , Cricetinae , Femenino , Cobayas , Humanos , Cinética , Hígado/efectos de los fármacos , Masculino , Mesocricetus , Ratones , Ratas , Ratas Endogámicas , Factores Sexuales , Fumar , Especificidad de la Especie
18.
J Clin Psychiatry ; 58 Suppl 16: 32-9, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9430507

RESUMEN

BACKGROUND: Functional magnetic resonance imaging (fMRI) techniques were used to identify the neural circuitry underlying emotional processing in control and depressed subjects. Depressed subjects were studied before and after treatment with venlafaxine. This new technique provides a method to noninvasively image regional brain function with unprecedented spatial and temporal resolution. METHOD: Echo-planar imaging was used to acquire whole brain images while subjects viewed positively and negatively valenced visual stimuli. Two control subjects and two depressed subjects who met DSM-IV criteria for major depression were scanned at baseline and 2 weeks later. Depressed subjects were treated with venlafaxine after the baseline scan. RESULTS: Preliminary results from this ongoing study revealed three interesting trends in the data. Both depressed patients demonstrated considerable symptomatic improvement at the time of the second scan. Across control and depressed subjects, the negative compared with the positive pictures elicited greater global activation. In both groups, activation induced by the negative pictures decreased from the baseline scan to the 2-week scan. This decrease in activation was also present in the control subjects when they were exposed to the positive pictures. In contrast, when the depressed subjects were presented with the positive pictures they showed no activation at baseline, whereas after 2 weeks of treatment an area of activation emerged in right secondary visual cortex. CONCLUSION: While preliminary, these results demonstrate the power of using fMRI to study emotional processes in normal and depressed subjects and to examine mechanisms of action of antidepressant drugs.


Asunto(s)
Encéfalo/fisiología , Ciclohexanoles/farmacología , Trastorno Depresivo/diagnóstico , Emociones/fisiología , Imagen por Resonancia Magnética , Inhibidores Selectivos de la Recaptación de Serotonina/farmacología , Adolescente , Adulto , Encéfalo/anatomía & histología , Encéfalo/efectos de los fármacos , Ciclohexanoles/uso terapéutico , Trastorno Depresivo/tratamiento farmacológico , Trastorno Depresivo/psicología , Imagen Eco-Planar , Emociones/efectos de los fármacos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica , Inhibidores Selectivos de la Recaptación de Serotonina/uso terapéutico , Resultado del Tratamiento , Clorhidrato de Venlafaxina , Corteza Visual/anatomía & histología , Corteza Visual/efectos de los fármacos , Corteza Visual/fisiología , Percepción Visual/fisiología
19.
Radiat Res ; 59(3): 665-78, 1974 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-4428015

RESUMEN

PIP: A portable unit was developed to provide uniform irradiation of the human testes. The device had built-in radiological protection and provided a dosage independent of the subject geometry, uniform to within +or- 5%. Single doses, between 8-600 rad were administered to the testes of human subjects. Observations were made both before and following irradiation. Parameters evaluated included sperm concentration, motility and morphology, seminal fluid volume, plasma and urinary gonadotropin and testosterone levels, urinary estrogens, and comparison of testicular biopsies taken before and after irradiation in the same subject. Dose-response relationships and recovery times were determined for each dose range studied.^ieng


Asunto(s)
Efectos de la Radiación , Testículo/efectos de la radiación , Adulto , Relación Dosis-Respuesta en la Radiación , Estrógenos/orina , Hormona Folículo Estimulante/sangre , Hormona Folículo Estimulante/orina , Humanos , Células Intersticiales del Testículo/efectos de la radiación , Hormona Luteinizante/sangre , Hormona Luteinizante/orina , Masculino , Persona de Mediana Edad , Células de Sertoli/efectos de la radiación , Espermatogénesis/efectos de la radiación , Espermatozoides/efectos de la radiación , Testosterona/sangre , Testosterona/orina
20.
J Appl Physiol (1985) ; 62(6): 2201-11, 1987 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-3610915

RESUMEN

We studied the effect of hypoxia-induced unstable and periodic breathing on the incidence of obstructed breaths in nine subjects who varied widely in their increase in total pulmonary resistance (RL) during non-rapid-eye-movement (NREM) sleep. During normoxic NREM sleep, all subjects showed hypoventilation, augmented diaphragmatic electromyogram (EMGdi), and increased RL. This response varied: two subjects doubled their mean RL (range 6-9 cmH2O X l-1 X s); four moderate snorers increased RL four- to eightfold (RL = 16-48 cmH2O X l-1 X s); three heavy snorers showed high RL (31-89 cmH2O X l-1 X s) plus cyclical obstructive hypopnea as their predominant breathing pattern. In seven of nine subjects, hypoxia and coincident hypocapnia initially caused an irregular cyclical breathing pattern with obstructed breaths (RL greater than 50 cmH2O X l-1 X s). The incidence of obstructed breaths induced by unstable breathing was closely correlated with the level of RL experienced in the control condition of normoxic sleep (r = 0.91). The obstructed breaths had relatively high O2 saturation (90-96%) and markedly reduced EMGdi activity and peak flow rate (less than 0.2 l/s) compared with breaths immediately after the obstructed breaths, which showed lower O2 saturation (81-93%) and markedly augmented EMGdi and flow rates. After 3-6 cycles of obstructive hypopnea, periodic breathing occurred in most subjects. During periodic breathing in six of seven subjects, the incidence of obstructed or high-resistance breaths was decreased or eliminated since each central apneic period was followed by breath clusters characterized by very high EMGdi, very low RL, and high flow rates. The remaining subject showed a high incidence of obstructed breaths during all phases of normoxic and hypoxic sleep. These data show that hypoxia-induced instability in breathing pattern can cause obstructed breaths during sleep coincident with reduced motor output to inspiratory muscles. However, this obstruction is only manifested in subjects susceptible to upper airway atonicity and narrowing (such as snorers) and can be prevented in most cases if respiratory drive is permitted to reach sufficiently high levels (as during central apnea).


Asunto(s)
Obstrucción de las Vías Aéreas/fisiopatología , Hipoxia/fisiopatología , Respiración , Sueño , Ronquido/fisiopatología , Adulto , Apnea/fisiopatología , Electromiografía , Femenino , Humanos , Masculino , Volumen de Ventilación Pulmonar
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