RESUMEN
When a massive star explodes as a supernova, substantial amounts of radioactive elements--primarily (56)Ni, (57)Ni and (44)Ti--are produced. After the initial flash of light from shock heating, the fading light emitted by the supernova is due to the decay of these elements. However, after decades, the energy powering a supernova remnant comes from the shock interaction between the ejecta and the surrounding medium. The transition to this phase has hitherto not been observed: supernovae occur too infrequently in the Milky Way to provide a young example, and extragalactic supernovae are generally too faint and too small. Here we report observations that show this transition in the supernova SN 1987A in the Large Magellanic Cloud. From 1994 to 2001, the ejecta faded owing to radioactive decay of (44)Ti as predicted. Then the flux started to increase, more than doubling by the end of 2009. We show that this increase is the result of heat deposited by X-rays produced as the ejecta interacts with the surrounding material. In time, the X-rays will penetrate farther into the ejecta, enabling us to analyse the structure and chemistry of the vanished star.
RESUMEN
The Houston Diabetes Control Program is part of an effort by the State of Texas and approximately 30 other programs throughout the United States to ensure that persons with diabetes-related complications receive ongoing state-of-the-art preventive care and treatment. For the past 5 years, this program has served an urban, high-risk patient population with special cultural, ethnic, and economic challenges. The intervention has included the development and implementation of protocols for the prevention and care of diabetes-related complications of the eyes, lower extremities, and cardiovascular system, as well as general management of diabetes and patient and professional education. The program is ongoing in nine community health centers located in low-income neighborhoods of a large metropolitan area. The results thus far indicate an increase in sensitive eye examinations from 8 percent to 26 percent of the patient population, a reduction in incidence of legal blindness from 9.5 to 2.7 per 1,000 during a 4-year period, an increase in foot examinations from 18 percent to 44 percent of the patient population, and 77 percent of hypertensive patients in good control of blood pressure at less than 160 over 95 mmHg (millimeters of mercury). On the average, there have not been significant long-term improvements in weight reduction or blood glucose control. The major challenges for this program are (a) improvement in control of glycemia, hypertension, and cholesterol; (b) more effective diet and physical activity interventions; and (c) more effective education approaches that help patients to understand metabolic and cardiovascular functions. These challenges will require collaboration of health care professionals in constructive and imaginative ways through their unselfish commitment toward common goals.
Asunto(s)
Diabetes Mellitus/terapia , Oftalmopatías/prevención & control , Enfermedades del Pie/prevención & control , Educación del Paciente como Asunto , Anciano , Enfermedades Cardiovasculares/prevención & control , Centros Comunitarios de Salud , Ahorro de Costo , Complicaciones de la Diabetes , Educación Médica Continua , Oftalmopatías/economía , Oftalmopatías/etiología , Femenino , Enfermedades del Pie/etiología , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Programas y Proyectos de Salud , Factores de Riesgo , Texas , Salud UrbanaRESUMEN
The role of the stomach in regulating appetite in bulimia nervosa was examined. Subjects were nine normal and nine bulimic women of similar age, height, and weight. Gastric capacity was estimated by filling a balloon in the stomach. The mean stomach capacity of bulimic subjects was significantly larger than that of normal subjects, as revealed by the larger balloon volume tolerated (P less than 0.01) and by the larger volume needed to produce a 5 cm H2O increase in intragastric pressure (P = 0.07). The intake of a liquid meal was also significantly larger for the bulimic subjects. Gastric-emptying rate of a liquid meal was significantly delayed in the bulimic subjects during the initial 5-15 min. In all subjects, test-meal intake correlated significantly with gastric capacity (r = 0.53). In the bulimic subjects, self-reported binge intake (J) also correlated significantly with gastric capacity (r = 0.75). Binge eating in bulimic subjects may enlarge gastric capacity, which could then promote even larger binges through positive feedback.
Asunto(s)
Bulimia/fisiopatología , Ingestión de Alimentos , Vaciamiento Gástrico , Estómago/patología , Adulto , Bulimia/patología , Femenino , Humanos , CinéticaRESUMEN
A study was conducted to test the efficacy and safety of a 300 ml silicone-rubber gastric balloon for weight reduction. Eighty-six obese subjects were distributed into four groups: (1) gastric balloon only, (2) gastric balloon and prescribed 1000 kcal/day (239 kJ) diet, (3) 1000 kcal/day diet only, and (4) no treatment. The intervention period was 3 months. The balloon only group lost 3.2 kg +/- 0.9 (s.e.), the balloon and diet group lost 5.1 +/- 1.0 kg, the diet group lost 6.9 +/- 1.4 kg and the control group gained 0.6 +/- 0.5 kg. The three intervention groups each lost significantly more weight than the control group. The diet only group lost significantly more weight than the balloon only group. Body densitometry showed that the treatment groups lost a significant amount of body fat. Gastroscopy revealed three ulcers and two superficial erosions at balloon removal. The gastric balloons were well tolerated despite gastric spasms and nausea which abated after the initial 24-48 hours. Gastric capacity was determined in a subset of 19 subjects from the two balloon groups before the intervention by distending the stomach with a balloon and calculating the volume required to produce an increase in intragastric pressure of 5 cm H2O. Subjects with a smaller gastric capacity lost more weight with the balloon than subjects with a large capacity (r = 0.45, P less than 0.05). These results suggest that for improved efficacy, balloon volume may need to be larger than 300 ml or adjusted to the individual's gastric capacity.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Balón Gástrico , Obesidad/terapia , Composición Corporal , Dieta Reductora , Ingestión de Energía , Femenino , Estudios de Seguimiento , Gastrinas/sangre , Humanos , Masculino , Obesidad/tratamiento farmacológico , Estómago/anatomía & histología , Úlcera Gástrica/etiología , Pérdida de PesoRESUMEN
To determine its efficacy and safety in treating obesity, a silicone-rubber balloon was passed into the stomach of 10 nondieting, obese subjects. In a counterbalanced sequence, the balloon was inflated with 400 mL for 1 mo and deflated for 1 mo. Lower intakes of solid and liquid test meals (NS), significantly slower gastric emptying, and concomitant changes in glucose, insulin, glucagon, and cholecystokinin concentrations consistent with slower emptying resulted during balloon inflation. After balloon inflation, one small gastric ulcer developed, which subsequently healed. Significant weight loss occurred during the second and third week of the inflation period (F[1,9] = 5.0, p less than 0.05). However, the weight loss was small and the significant effect did not continue through the fourth week.
Asunto(s)
Balón Gástrico , Obesidad/terapia , Adulto , Método Doble Ciego , Ingestión de Alimentos , Femenino , Balón Gástrico/efectos adversos , Vaciamiento Gástrico , Glucagón/metabolismo , Glucosa/metabolismo , Humanos , Insulina/metabolismo , Masculino , Obesidad/metabolismo , Factores de Tiempo , Pérdida de PesoRESUMEN
Treatment of duodenal ulcer with the histamine H2-receptor antagonist, ranitidine, was assessed in a double-blind, randomized, multicenter trial in which patients were treated for two consecutive 4-week periods with ranitidine 150 mg b.i.d. or a placebo. All patients were allowed to take antacids as necessary for symptoms. Three hundred eighty-two patients were entered and 355 completed the first 4-week trial period. Ranitidine significantly improved healing at 2 weeks (37 versus 19%, p less than 0.01) and at 4 weeks (73 versus 45%, p less than 0.01), with better relief of pain and lower use of antacids. In the second 4-week trial period, 124 unhealed patients from the first 4 weeks were re-randomized. Ranitidine treatment resulted in a greater healing rate regardless of previous treatment (p less than 0.05). In this trial, side effects were uncommon and not different between placebo and the tested drug. One case of hepatitis in the ranitidine treated group was presumed on the evidence to be non-A non-B. Ranitidine is effective and appears to be safe in the treatment of duodenal ulcer and its symptoms.
Asunto(s)
Úlcera Duodenal/tratamiento farmacológico , Ranitidina/uso terapéutico , Adulto , Anciano , Antiácidos/uso terapéutico , Ensayos Clínicos como Asunto , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Distribución Aleatoria , Estados Unidos , Cicatrización de HeridasAsunto(s)
Estenosis Esofágica/terapia , Gastrostomía , Anciano , Dilatación/métodos , Nutrición Enteral , Esofagoscopía , Femenino , HumanosRESUMEN
This study compared the pain-relieving effects of shortwave diathermy and moist heat on trigger points. Patients with trigger points on the neck or back were randomly assigned one of these treatments. The sensitivity of each trigger point was measured with a pressure algometer before treatment, 5 minutes after treatment, and 30 minutes after treatment. Sensitive trigger points, at which 2000 grams of force or less caused pain, were more responsive to treatment than moderate trigger points (painful only at 2000 grams or greater force). Both treatments were effective in relieving the pain of sensitive trigger points but shortwave diathermy was more effective at decreasing the sensitivity of both sensitive and moderate trigger points (P > 0.0581). The pressure algometer was shown to be a useful device for objectively measuring pain and may be useful in selecting the most effective type of treatment for trigger points.J Orthop Sports Phys Ther 1984;5(4):175-178.