Asunto(s)
Coronavirus , Neumonía Viral , Betacoronavirus , COVID-19 , Infecciones por Coronavirus , Humanos , Pandemias , SARS-CoV-2 , TermómetrosRESUMEN
BACKGROUND AND PURPOSE: IAs are found in 2.3% of adults; the mean age at detection is 52 years. Prevalence is <0.5% in young adults. Early studies suggest that 10%-50% of patients with aortic coarctation have IAs. Screening recommendations are variable. We sought to examine the prevalence of IAs through screening with MRA. MATERIALS AND METHODS: Consecutive patients older than 16 years of age with coarctation undergoing brain MRA between May 1999 and October 2007 were included. MRA was performed by using a 1.5T scanner with a 3D time-of-flight protocol; simultaneous MR imaging was performed of the heart and aorta. Cerebral MRAs were double-reported by a neuroradiologist. Statistics are described as mean ± SD and median ± range. Continuous variables were compared by using Student t tests and Mann-Whitney U tests (categoric variables, by using the Fisher exact test). RESULTS: One hundred seventeen MRAs were double-reported. The median age was 29 ± 11 years (range, 16-59 years). IAs were found in 12 patients (10.3%). The mean diameter of IAs was 3.9 mm (range, 2.0-8.0 mm). Patients with aneurysms were older (median, 37 years; range, 16-50 years) than those without (median, 23 years; range, 16-59 years; Z = -2.01, P = .04). Hypertension was more common in those with IAs (IA 83% versus no IA 43%, P = .01). There was no association between ascending aortopathy, bicuspid aortic valves, and IAs. CONCLUSIONS: Patients with coarctation have a higher prevalence of IAs, occurring at an earlier age than in population studies. Whether routine screening is appropriate for this group of patients is unclear. Hypertension is likely to be an important pathophysiologic factor.
Asunto(s)
Coartación Aórtica/diagnóstico , Coartación Aórtica/epidemiología , Aneurisma Intracraneal/diagnóstico , Aneurisma Intracraneal/epidemiología , Angiografía por Resonancia Magnética/estadística & datos numéricos , Tamizaje Masivo/estadística & datos numéricos , Adolescente , Adulto , Anciano , Causalidad , Comorbilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Factores de Riesgo , Reino Unido/epidemiologíaRESUMEN
Papillary carcinoma is the most common form of thyroid cancer. It is a relatively indolent disease, which commonly remains clinically silent until its incidental histological diagnosis in surgical material or at autopsy. A tumour less than 10 mm in size is termed a papillary microcarcinoma. Papillary microcarcinoma may present with clinical symptoms, most commonly jugulodigastric and pretracheal lymphadenopathy with or without palpable thyroid nodules. Isolated submandibular metastases are rare. We present the case of a submandibular metastasis arising from a solitary 3 mm papillary microcarcinoma of the thyroid on the contralateral side in a 46-year-old woman. We describe the ultrasound and MRI characteristics of the submandibular mass. The ultrasound findings in particular were suggestive of a thyroid malignancy and prompted detailed examination of the thyroid gland. Clinical and radiological examination of the thyroid was normal. To the best of our knowledge, we present the first report of a papillary microcarcinoma of the thyroid presenting as a contralateral and isolated submandibular mass.
Asunto(s)
Carcinoma Papilar/secundario , Neoplasias de la Glándula Submandibular/secundario , Neoplasias de la Tiroides/patología , Biopsia con Aguja Fina , Carcinoma Papilar/diagnóstico por imagen , Carcinoma Papilar/patología , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Neoplasias de la Glándula Submandibular/diagnóstico por imagen , Ultrasonografía Doppler en ColorRESUMEN
Humans and some birds and insects sometimes prefer alternatives associated with greater past cost or need, sometimes affording losses. It has been proposed that this is widespread because learning may include knowledge about both the physical properties of alternatives and state-dependent fitness gains. We examine the phenomenon for the first time in a fish, the banded tetra (Astyanax fasciatus). During training we paired two different color cues to identical food rewards, one under greater deprivation than the other. We then tested preference between these cues under both deprivation states. Consistent with previous results in other taxa, the fish preferred the cue associated with previous greater deprivation regardless of the condition under which they were tested. These results provide further support to the view that organisms assign value using state-dependent increments in fitness during learning. Although generally adaptive, under experimental conditions state-dependent valuation learning can lead to paradoxical choices.
Asunto(s)
Condicionamiento Operante/fisiología , Peces/fisiología , Privación de Alimentos/fisiología , Aprendizaje/fisiología , Animales , Color , Señales (Psicología) , Toma de Decisiones/fisiología , Alimentos , Hambre/fisiología , Desempeño Psicomotor/fisiología , Refuerzo en Psicología , RecompensaRESUMEN
We report a case of a 79-year-old woman with long-standing achalasia that resulted in respiratory stridor and dyspnea. She was evaluated for tracheal compression with use of CT on inspiration and expiration. Airway obstruction and acute respiratory distress secondary to achalasia have been reported in the clinical literature. The importance of recognizing these rare manifestations is crucial for the appropriate treatment of these patients. In this patient, the CT evaluation of tracheal compression provided useful information on the degree of narrowing caused by the dilated esophagus.
Asunto(s)
Acalasia del Esófago/complicaciones , Acalasia del Esófago/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Estenosis Traqueal/diagnóstico por imagen , Estenosis Traqueal/etiología , Anciano , Disnea/etiología , Femenino , Humanos , Ruidos Respiratorios/etiologíaRESUMEN
We report a case of pneumocephalus, as a complication of diverticulitis, in a 48-year-old man who presented with back pain and mild disorientation. There are no previous reports of diverticulitis causing this phenomenon.
Asunto(s)
Diverticulitis del Colon/complicaciones , Neumocéfalo/etiología , Absceso/complicaciones , Absceso/diagnóstico por imagen , Dolor de Espalda/etiología , Diverticulitis del Colon/diagnóstico por imagen , Humanos , Hidronefrosis/diagnóstico por imagen , Hidronefrosis/etiología , Masculino , Persona de Mediana Edad , Neumocéfalo/diagnóstico por imagen , Tomografía Computarizada por Rayos XRESUMEN
Hypoxia-inducible factor-1alpha (HIF-1alpha) is a transcription factor that regulates the oxygen-dependent expression of a number of genes. This transcription factor may contribute to the abundant expression of many genes in renal medullary cells that function normally under hypoxic conditions. The present study was designed to determine the characteristics of HIF-1alpha cDNA cloned from the rat kidney and the expression profile of HIF-1alpha in different kidney regions and to explore the mechanism activating or regulating HIF-1alpha expression in renal medullary cells. A 3,718-bp HIF-1alpha cDNA from the rat kidney was first cloned and sequenced using RT-PCR and TA cloning technique. It was found that 823 amino acids deduced from this renal HIF-1alpha cDNA had 99%, 96%, and 90% identity with rat, mouse, or human HIF-1alpha deposited in GenBank, respectively. The 3'-untranslated region of HIF-1alpha mRNA from the rat kidney contained seven AUUUA instability elements, five of which were found to be conserved among rat, mouse, and human HIF-1alpha. Northern blot analyses demonstrated a corticomedullary gradient of HIF-1alpha mRNA expression in the kidney, with the greatest abundance in the renal inner medulla. Western blot analyses also detected a higher HIF-1alpha protein level in the nuclear extracts from the renal medulla than the renal cortex. A classic loop diuretic, furosemide (10 mg/kg ip), markedly increased renal medullary Po(2) levels from 22.5 to 52.2 mmHg, which was accompanied by a significant reduction of HIF-1alpha transcripts in renal medullary tissue. In in vitro experiments, low Po(2), but not elevated osmolarity, was found to significantly increase HIF-1alpha mRNA in renal medullary interstitial cells and inner medullary collecting duct cells. These results indicate that HIF-1alpha is more abundantly expressed in the renal medulla compared with the renal cortex. Increased abundance of HIF-1alpha mRNA in the renal medulla may represent an adaptive response of renal medullary cells to low Po(2).