The sodium concentration gradient in the kidney (from the cortex to the medulla) serves to regulate fluid homeostasis and is tightly coupled to renal function. It was previously shown that renal function and pathophysiology can be characterized in rat kidneys by measuring the sodium gradient with (23)Na MRI. This study demonstrates for the first time the ability of (23)Na MRI to map the distribution of sodium in the human kidney and to quantify the corticomedullary sodium gradient. The study was performed on a 3T Signa LX scanner (GE) using an in-house-built quadrature surface coil. (23)Na images of volunteers were acquired using a 3D coronal gradient-echo sequence at a spatial resolution of 0.3 x 0.3 x 1.5 cm(3) in a 25-min scan time. The signal intensity (relative to the noise) increased linearly from the cortex to each of the medullae with a mean slope of 1.6 +/- 0.2 in relative arbitrary units per mm (Rel.u./mm, N = 6) and then decreased, as expected, toward the renal pelvis. Water deprivation (12 hr) induced a significant increase of 25% (P < 0.05) in this gradient. Based on these results, we suggest that sodium MRI can serve as a valuable noninvasive method for functional imaging of the human kidney. 相似文献
L1 disease is the most common genetic cause of congenital hydrocephalus. Mutations in the L1CAM gene are associated with an overlapping clinical spectrum of four X-linked neurological conditions, characterized by hydrocephalus, mental retardation, lower limb spasticity and adducted thumbs. Brain anomalies are frequently present in L1 disease. We describe these anomalies by reporting a case of a male newborn presenting with congenital hydrocephalus along with corpus callosum agenesis and enlargement of the massa intermedia. These findings, in association with the presence of clasped thumbs, raised the suspicion of L1 disease, which was confirmed by the detection of a mutation in the L1CAM gene. In cases of congenital hydrocephalus, recognition of the brain anomalies associated with L1 disease may contribute to pursuing the genetic analysis needed for the diagnosis and genetic counseling. 相似文献
OBJECTIVE: The authors examined the accuracy of certain neuropsychological tests in the prediction of harm resulting from self-neglect in cognitively impaired seniors who lived alone. METHODS: The study included 130 participants, aged 65 and older, who scored less than 131 on the Dementia Rating Scale. Neuropsychological tests were administered at baseline, resulting in eight predictive scores. Informants and primary care physicians provided information about harm that occurred to the participants during the 18-month prospective follow up. An incident was defined as harmful if it occurred as the result of self-neglect or disorientation and resulted in physical injury or property loss or damage and required emergency interventions. Proportional hazard regression analysis was conducted to examine the predictive relationship between the eight neuropsychological tests and time to incident harm with age, sex, education, the Charlson Comorbidity Index, and the Mini-Mental State Examination included in the model as covariates. RESULTS: Twenty-seven participants experienced harm during the 18-month follow-up period. A proportional hazards model indicated that three neuropsychological tests, which measured recognition memory, executive functioning, and conceptualization, were independent risk factors for harm. CONCLUSIONS: These findings provide insight into why harm occurred in these cognitively impaired elders who lived alone. They also support the ecologic validity of these tests and suggest directions for the development of intervention strategies for harm prevention. 相似文献
Background: Anesthesiologists and anesthesia residents are expected to acquire and maintain skills to manage a wide range of acute intraoperative anesthetic events. The purpose of this study was to determine whether an inventory of simulated intraoperative scenarios provided a reliable and valid measure of anesthesia residents' and anesthesiologists' skill.
Methods: Twelve simulated acute intraoperative scenarios were designed to assess the performance of 64 residents and 35 anesthesiologists. The participants were divided into four groups based on their training and experience. There were 31 new CA-1, 12 advanced CA-1, and 22 CA-2/CA-3 residents as well as a group of 35 experienced anesthesiologists who participated in the assessment. Each participant managed a set of simulated events. The advanced CA-1 residents, CA-2/CA-3 residents, and 35 anesthesiologists managed 8 of 12 intraoperative simulation exercises. The 31 CA-1 residents each managed 3 intraoperative scenarios.
Results: The new CA-1 residents received lower scores on the simulated intraoperative events than the other groups of participants. The advanced CA-1 residents, CA-2/CA-3 residents, and anesthesiologists performed similarly on the overall assessment. There was a wide range of scores obtained by individuals in each group. A number of the exercises were difficult for the majority of participants to recognize and treat, but most events effectively discriminated among participants who achieved higher and lower overall scores. 相似文献
PURPOSE: To determine whether 3-dimensional ultrasonography (3D US) provides information about anatomy and position of extraocular muscles to better guide surgeons approaching strabismus in patients with craniosynostosis who often have anomalous or absent eye muscles. METHODS: The 4 rectus eye muscles were imaged using 3D US for 7 children with craniosynostosis before or after strabismus surgery. Reconstructed 3D images were interpreted as having normal or abnormal anatomy and position, based on comparison with images acquired from 6 normal eyes. Interpretation was validated against the intraoperative findings from strabismus surgery. RESULTS: A total of 34 scans from the study group were used for comparison and validation purposes. Accuracy of anatomical assessments was 85% +/- 12% (percentage +/- confidence interval) and of positional assessments was 62% +/- 16%. Sensitivity and specificity of anatomical assessments was 80% +/- 14% and 88% +/- 10%, respectively. Anatomic anomalies detected by 3D US included excessively thick, thin, scarred and fibrotic, and absent muscles. Sensitivity and specificity of positional assessments was 48% +/- 17% and 85% +/- 12%, respectively. Positional anomalies such as muscle displacement off the normal clock hour axis or posteriorly displaced insertion were also detected. CONCLUSIONS: The 3D US may have an adjunctive role in determining anatomy and position of rectus muscles in patients with craniosynostosis, although it was more accurate in assessing anatomic features rather than positional features of rectus muscles. 相似文献
The purpose of the present study was to evaluate the haemostatic efficacy of fibrin sealant in patients with hereditary haemorrhagic telangiectasia (HHT) or Rendu-Osler-Weber disease suffering epistaxis. A retrospective observational study of patients with HHT who were admitted to an emergency room for anterior or posterior epistaxis during May 2000-March 2003. A total of 24 patients were evaluated, of whom 15 were managed with foam nasal packing during May 2000-March 2002 and another nine were treated during March 2002-March 2003 with 0.3 ml fibrin sealant spray (Quixil; Omrix, Belgium). The immediate and the distant results were compared. Immediate haemostasis was achieved in all seven patients treated with fibrin glue, with good healing of bleeding sites, no secondary bleeding, no inflammation, and no plaque or crists. Twelve months of follow-up monitoring (until October 2003) of atrophic changes of nasal mucosa, bleeding frequency and intensity proved absence of atrophy of nasal mucosa and decreased bleeding frequency. In this group, the bleeding episode duration averaged 2 min 35 s since the moment of admittance. In the nasal packing group, we found local swelling, pain, and slow healing of the bleeding site with accidental atrophy of nasal mucosa and no effect on further bleeding frequency and intensity. Removal of nasal packing frequently initiates secondary bleeding. The rates of these side effects were higher in comparison with the fibrin glue group. The bleeding episode duration was also longer. In patients with HHT suffering profuse epistaxis, fibrin glue is more effective and convenient for the patients as compared with foam nasal packing. It is also safer, since it lacks the complications that usually accompany packing as swelling, atrophy of the nasal mucosa, and secondary bleeding provoked by the removal of the pack. 相似文献