RESUMEN
A large number of studies in recent years have described protein and nitrogen metabolism in the neonate. However, the majority of these data are difficult to interpret because of a number of confounding variables, particularly in very low birth weight (VLBW) infants. In contrast, application of state-of-the-art tracer isotopic and molecular biology methods in isolated cell system and whole animals has resulted in major advances in our understanding of the regulation of protein breakdown, synthesis, and protein accretion. The following workshop summary reviews the recent developments in basic physiology of protein metabolism in cellular and animal models in relation to human preterm infants, and identifies the important areas toward which future basic and clinical research should be directed to provide for optimal nitrogen accretion and growth of the VLBW infant.
Asunto(s)
Aminoácidos/metabolismo , Fenómenos Fisiológicos Nutricionales del Lactante , Recién Nacido de muy Bajo Peso/metabolismo , Proteínas/metabolismo , Femenino , Humanos , Recién Nacido , Masculino , Nitrógeno/metabolismo , Necesidades NutricionalesAsunto(s)
Fenómenos Fisiológicos Nutricionales del Lactante , Recién Nacido de muy Bajo Peso/metabolismo , Aminoácidos/metabolismo , Grasas de la Dieta/metabolismo , Proteínas en la Dieta/metabolismo , Sacarosa en la Dieta/metabolismo , Metabolismo Energético , Humanos , Alimentos Infantiles , Recién Nacido , Necesidades NutricionalesAsunto(s)
Desarrollo Embrionario y Fetal/fisiología , Retardo del Crecimiento Fetal , Animales , Femenino , Retardo del Crecimiento Fetal/diagnóstico , Retardo del Crecimiento Fetal/epidemiología , Retardo del Crecimiento Fetal/terapia , Humanos , Placenta/fisiología , Embarazo , Diagnóstico PrenatalRESUMEN
Brain imaging has become an integral part of the evaluation of neurological and psychiatric disorders. Functional imaging techniques, SPECT and PET, together with structural modalities, CT and MRI, are widely employed. Functional imaging studies are routinely used in the diagnostic workup of patients with well-characterized neurological disorders, such as epilepsy and brain tumors, and have a growing role in research on psychiatric disorders without known mechanisms such as depression and schizophrenia. Furthermore, many well-defined neurological disorders manifest prominent psychiatric symptomatology which may pose difficulties in differential diagnosis. This review addresses the current knowledge of SPECT findings in patients who present with psychiatric phenomena, associated with disorders at the interface of neurology and psychiatry.
Asunto(s)
Daño Encefálico Crónico/diagnóstico por imagen , Encefalopatías/diagnóstico por imagen , Neoplasias Encefálicas/diagnóstico por imagen , Trastornos Neurocognitivos/diagnóstico por imagen , Tomografía Computarizada de Emisión de Fotón Único , Enfermedad de Alzheimer/diagnóstico por imagen , Encéfalo/irrigación sanguínea , Encéfalo/diagnóstico por imagen , Lesiones Encefálicas/diagnóstico por imagen , Demencia/diagnóstico por imagen , Diagnóstico Diferencial , Epilepsia del Lóbulo Temporal/diagnóstico por imagen , Humanos , Enfermedad de Huntington/diagnóstico por imagen , Compuestos de Organotecnecio , Oximas , Enfermedad de Parkinson/diagnóstico por imagen , Flujo Sanguíneo Regional , Exametazima de Tecnecio Tc 99mRESUMEN
Pulmonary blood volume increase during systole was measured in patients by analysing chest images obtained during ECG gated radionuclide angiography examination. The difference in the total radiation counts between systole and diastole in regions of interest, which included the lungs and the left ventricle, was measured and the relative pulmonary systolic blood volume increase (SBVI)-the ratio between the pulmonary SBVI and the cardiac stroke volume-was calculated. The relative pulmonary SBVI, which is a measure for the compliance of the pulmonary blood vessels, was found to be 0.26-0.85, and the average value was 0.57 +/- 0.15. The relative pulmonary SBVI was inversely correlated with the patient age (r = 0.27, p < 0.05) and with the left ventricular ejection fraction and stroke volume (r = 0.36, p < 0.01) due to decreased arterial compliance for older patients and for increased pulmonary blood volume respectively. The correlation coefficients were not high, indicating that the compliance of the patients is determined mainly by other individual factors. Radionuclide plethysmography enables qualitative assessment of pulmonary arterial compliance.
Asunto(s)
Determinación del Volumen Sanguíneo/métodos , Electrocardiografía/métodos , Imagen de Acumulación Sanguínea de Compuerta/métodos , Circulación Pulmonar/fisiología , Envejecimiento/fisiología , Volumen Sanguíneo/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Pulmón/diagnóstico por imagen , Pletismografía , Volumen Sistólico/fisiología , Sístole/fisiología , Resistencia Vascular/fisiologíaRESUMEN
The epidemic of HIV infection and disease in women, adolescents and children represents a complexly intertwined biological and social challenge to health care workers and researchers alike. When considering various issues in confronting this epidemic, women must be viewed as individuals important in their own right, as the primary caretaker of their family members (both infected and uninfected), and as the sexual partners of men who may or may not be infected. Of the myriad of compelling biological questions facing AIDS researchers today, two of the most interesting involve the timing and determinants of vertical transmission and the natural history of HIV infection and disease in women. Scientifically, confronting this epidemic involves research into pathogenesis, epidemiology, natural history, treatment, and prevention of HIV infection. Primary emphasis in the research arena in HIV/AIDS in the United States is focused on therapeutic and prophylactic research. Other research issues are very important, including studies of early diagnostic techniques, behavioral research concerning reproductive choices, the role of breastfeeding in HIV transmission, HIV-specific adolescent issues, and surrogate markers of disease progression.
Asunto(s)
Síndrome de Inmunodeficiencia Adquirida , Síndrome de Inmunodeficiencia Adquirida/diagnóstico , Síndrome de Inmunodeficiencia Adquirida/tratamiento farmacológico , Síndrome de Inmunodeficiencia Adquirida/epidemiología , Síndrome de Inmunodeficiencia Adquirida/prevención & control , Síndrome de Inmunodeficiencia Adquirida/transmisión , Adolescente , Adulto , Niño , Ensayos Clínicos como Asunto , Femenino , Predicción , Humanos , Transmisión Vertical de Enfermedad Infecciosa , Masculino , Embarazo , Complicaciones Infecciosas del Embarazo/epidemiología , Complicaciones Infecciosas del Embarazo/virología , Proyectos de Investigación , Conducta Sexual , Estados Unidos/epidemiologíaRESUMEN
The US Food and Drug Administration (FDA) has proposed new labelling regulations that describe alternative approaches for providing additional information to support labelling a drug, already approved for use in adults, for use in children. Therefore, the study of drugs in paediatric populations may now be encouraged. Paediatric pharmacokinetic studies are an important part of these trials. This action by the FDA may help resolve the ethical and technological concerns about the performance of clinical trials in children, and may render paediatric clinical trials more feasible. Most investigations in children are opportunistic in nature and their design is often constrained by a requisite noninvasive approach. Appropriately applied population-based techniques for both pharmacokinetic and pharmacodynamic data analysis may represent the most robust approach for generating a sufficiently large and accurate database for the use of new or old drugs in paediatric patients. Accordingly, this information, which is crucial for paediatric labelling of any drug product, must be obtained in infants and children if we are to truly individualize therapy for paediatric patients. The funding of 6 Pediatric Pharmacology Research Units by the US National Institutes of Health, and guidelines for application of pharmacokinetic methods to children may further contribute to the performance of paediatric clinical trials.
Asunto(s)
Etiquetado de Medicamentos/legislación & jurisprudencia , Pediatría , Farmacocinética , Envejecimiento/metabolismo , Niño , Preescolar , Relación Dosis-Respuesta a Droga , Humanos , Lactante , Recién Nacido , Estados Unidos , United States Food and Drug AdministrationRESUMEN
In-111 DTPA octreotide, a labeled somatostatin analog, was reported to be superior to I-123 octreotide for detection of somatostatin-receptor-bearing tumors because of longer half-life and better labeling characteristics. In addition, renal rather than hepatobiliary clearance decreases intestinal interference and greatly reduces accumulation of the tracer in the gallbladder. Using the In-111 labeled octreotide, the authors noted distinct gallbladder visualization in one patient with an insulinoma who was studied following an overnight fast. In two additional patients scanned in the fasting state gallbladder uptake was also demonstrated. In all 3 patients, this uptake disappeared following a meal. The authors conclude that when using this imaging modality, abdominal scans should not be performed in the fasting state. Furthermore, if significant uptake is demonstrated in the gallbladder area, imaging should be repeated several hours later, following a fatty meal. Both false-positive and false-negative findings of pathologic uptake in this area will thus be avoided.
Asunto(s)
Vesícula Biliar/diagnóstico por imagen , Radioisótopos de Indio , Octreótido/análogos & derivados , Ácido Pentético/análogos & derivados , Reacciones Falso Negativas , Reacciones Falso Positivas , Ayuno , Femenino , Humanos , Insulinoma/diagnóstico por imagen , Neoplasias Pancreáticas/diagnóstico por imagen , Factores de Tiempo , Tomografía Computarizada de Emisión de Fotón ÚnicoAsunto(s)
Infecciones Bacterianas , Recien Nacido Prematuro , Micosis , Complicaciones Infecciosas del Embarazo , Enfermedades Vaginales , Infecciones Bacterianas/complicaciones , Infecciones Bacterianas/tratamiento farmacológico , Método Doble Ciego , Femenino , Humanos , Recién Nacido , Micosis/complicaciones , Micosis/tratamiento farmacológico , Embarazo , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Complicaciones Infecciosas del Embarazo/microbiología , Resultado del Embarazo , Vagina/microbiología , Enfermedades Vaginales/complicaciones , Enfermedades Vaginales/tratamiento farmacológico , Enfermedades Vaginales/microbiologíaRESUMEN
Image registration is a correlation procedure that allows the matching of images obtained by different imaging modalities, both structural and functional. Once registered, they can be combined in a single "fused" image. This technique can be used to improve the interpretation and the quantification of relatively low resolution images obtained in nuclear medicine or to achieve a better diagnosis and treatment planning when high resolution anatomical images are registered. Matching images obtained by different imaging modalities is a major challenge and the various registration techniques are briefly described. The extracranial head and neck region is a challenging field for image registration. A preliminary retrospective experience is presented emphasizing the technique feasibility in a routine clinical context. 2-D and 3-D approaches were used. The requirements for transferring registration technology from the image processing laboratory to clinical practice are discussed, and the contribution of this method to medical interdisciplinary communication is emphasized.
Asunto(s)
Diagnóstico por Imagen , Cabeza/anatomía & histología , Procesamiento de Imagen Asistido por Computador , Cuello/anatomía & histología , Anciano , Anciano de 80 o más Años , Presentación de Datos , Femenino , Neoplasias de Cabeza y Cuello/diagnóstico , Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Humanos , Aumento de la Imagen , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Tomografía Computarizada de Emisión de Fotón Único/métodosRESUMEN
During cardiac systole the stroke volume of blood which is ejected from the right ventricle increases the pulmonary blood volume. This systolic pulmonary blood volume increase is measured by using ECG gated chest scintigrams obtained with 99Tcm-labelled red blood cells. The total radiation counts in a region of interest that includes either the right or the left lung increases during systole. On the average, the increase of the total pulmonary systolic radiation was found to be 62% of the systolic radiation decrease in the left ventricle region of interest. The discrepancy between the value of the systolic pulmonary blood volume increase and that of stroke volume is attributed to blood flow from the lungs into the left atrium during the cardiac systole period.
Asunto(s)
Determinación del Volumen Sanguíneo/métodos , Pulmón/fisiología , Pletismografía/métodos , Sístole/fisiología , Adulto , Anciano , Eritrocitos , Humanos , Persona de Mediana Edad , TecnecioRESUMEN
Temporal lobe epilepsy is diagnosed by clinical symptoms and signs and by localization of an epileptogenic focus. A brain SPECT study of two patients with temporal lobe epilepsy, using 99mTc-HMPAO, was used to demonstrate a perfusion abnormality in the temporal lobe, while brain CT and MRI were non-contributory. The electroencephalogram, though abnormal, did not localize the diseased area. The potential role of the SPECT study in diagnosis and localization of temporal lobe epilepsy is discussed.
Asunto(s)
Encéfalo/diagnóstico por imagen , Epilepsia del Lóbulo Temporal/diagnóstico por imagen , Tomografía Computarizada de Emisión de Fotón Único , Adulto , Encéfalo/patología , Epilepsia del Lóbulo Temporal/patología , Femenino , Humanos , Imagen por Resonancia Magnética , Tomografía Computarizada por Rayos XRESUMEN
Phenobarbital, when administered prenatally in a small dose to animals, produced profound, and permanent effects on reproductive function in the offspring. Preliminary analysis of a unique cohort of adolescents who were exposed to phenobarbital in utero, suggests that long-term effects are also evident in the human. The precise nature of these effects is currently being determined and will be reported separately. These effects may be qualitatively and quantitatively different from effects seen in animals because of species difference in the timing or neuroendocrine differentiation. Of greater importance, however, is the fact that biologic and pharmacologic effects can be seen in the human following exposure to xenobiotics perinatally. Implications for other pharmacologic agents await further investigation. The rat model appears to have validity for extrapolation to man.
Asunto(s)
Desarrollo Embrionario y Fetal/efectos de los fármacos , Ictericia Neonatal/prevención & control , Intercambio Materno-Fetal , Fenobarbital/toxicidad , Fenobarbital/uso terapéutico , Animales , Método Doble Ciego , Estro/efectos de los fármacos , Femenino , Estudios de Seguimiento , Genitales Masculinos/anomalías , Humanos , Recién Nacido , Masculino , Fenobarbital/efectos adversos , Embarazo , Valores de ReferenciaRESUMEN
Phenobarbital, when administered prenatally to animals, produced profound and prominent effects on reproduction. Preliminary analysis of a unique cohort of adolescents who were exposed to phenobarbital in utero suggests that long-term effects may be evident in the human as well.