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Local treatment options for ductal carcinoma in situ (DCIS) are virtually identical to those for early invasive breast cancer, despite the fact that the survival from this condition is much higher. Our ability to more appropriately tailor therapy for DCIS is hampered by a lack of understanding of the natural history of DCIS, our limited ability to predict the rate of progression to invasive cancer and the response to therapy, and the absence of tools to follow patients who have not had invasive treatments. Neoadjuvant therapy, which has been proven to be both safe and effective in tailoring treatments for invasive cancer, could be ideally suited to DCIS. However, neoadjuvant therapy requires that doctors and patients delay surgical treatment that has known benefits. In order to successfully introduce this approach into clinical practice, risk assessment and decision support tools will be needed to help physicians and patients feel comfortable that they are not being exposed to unnecessary or excessive risk. In addition, we need better imaging to track extent and progression of disease. Among the possible benefits of the neoadjuvant approach, we may discover that many lesions are responsive and some even reversible, leaving us with treatments that might be tailored to biology and with important clues for breast cancer prevention in high-risk women.  相似文献   
94.
Before meaningful conclusions can be drawn from clinical measures of cerebral blood perfusion, the precision of the measurement must be determined and set in the context of inter- and intrasubject sources of variability. This work establishes the reproducibility of perfusion measurements using the noninvasive MRI technique of continuous arterial spin labeling (CASL). Perfusion was measured in 34 healthy normal subjects. Intersubject variability was assessed, and age and gender contributions were estimated. Intersubject variation was found to be large, with up to 100% perfusion difference for subjects of the same age and gender. Repeated measurements in one subject showed that perfusion remains remarkably stable in the short term when compared with intersubject variation and the large capacity for perfusion change in the brain. A significant decrease in the ratio of gray-matter to white-matter perfusion was found with increasing age (0.79% per year (P < 0.0005)). This appears to be due mainly to a reduction in gray-matter perfusion, which was found to decrease by 0.45% per year (P = 0.04). Regional analysis suggested that the gray-matter age-related changes were predominantly localized in the frontal cortex. Whole-brain perfusion was 13% higher (P = 0.02) in females compared to males.  相似文献   
95.
Sphingolipid metabolites in neural signalling and function   总被引:8,自引:0,他引:8  
Sphingolipid metabolites, such as ceramide, sphingosine, sphingosine-1-phosphate (S1P) and complex sphingolipids (gangliosides), are recognized as molecules capable of regulating a variety of cellular processes. The role of sphingolipid metabolites has been studied mainly in non-neuronal tissues. These studies have underscored their importance as signals transducers, involved in control of proliferation, survival, differentiation and apoptosis. In this review, we will focus on studies performed over the last years in the nervous system, discussing the recent developments and the current perspectives in sphingolipid metabolism and functions.  相似文献   
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Multiple vascular lesions in the brain were identified by angiography in a 45-year-old woman with Von Hippel Lindau disease. One of these lesions was a histologically-proven hemangioblastoma. The occurrence of such lesions in a cerebral hemisphere is exceedingly rare and is usually related to Von Hippel Lindau disease.  相似文献   
98.
Methadone maintenance therapy for the treatment of opioid dependence continues to carry a social stigma. Until recently, patients on methadone were not considered for liver transplantation. We describe the first case of a patient on methadone who received a liver transplant for end stage liver disease and was successfully treated for recurrent hepatitis C. More than five years post transplant and three years post viral clearance, the patient continues to do well and is stable on low-dose methadone. This case emphasizes the need to reconsider the non-evidence based policy adopted by transplant centers that require methadone maintenance therapy patients to stop methadone prior to consideration for transplant evaluation.  相似文献   
99.
OBJECTIVE: Transmission of Staphylococcus aureus via air may play an important role in healthcare settings. This study investigates the impact of barrier precautions on the spread of airborne S. aureus by volunteers with experimentally induced rhinovirus infection (ie, the common cold). DESIGN: Prospective nonrandomized study. SETTING: Wake Forest University School of Medicine (Winston-Salem, NC).Participants. A convenience sample of 10 individuals with nasal S. aureus carriage selected from 593 students screened for carriage. INTERVENTION: Airborne S. aureus dispersal was studied in the 10 participants under the following clothing conditions: street clothes, surgical scrubs, surgical scrubs and a gown, and the latter plus a face mask. After a 4-day baseline period, volunteers were exposed to a rhinovirus, and their clinical course was followed for 12 days. Daily swabs of nasal specimens, pharynx specimens, and skin specimens were obtained for quantitative culture, and cold symptoms were documented. Data were analyzed by random-effects negative binomial models. RESULTS: All participants developed a common cold. Incidence rate ratios (IRRs) indicated that, compared with airborne levels of S. aureus during sessions in which street clothes were worn, airborne levels decreased by 75% when surgical scrubs were worn (P<.001), by 80% when scrubs and a surgical gown were worn (P<.001), and by 82% when scrubs, a gown, and a face mask were worn (P<.001). The addition of a mask to the surgical scrubs and gown did not reduce the airborne dispersal significantly (IRR, 0.92; P>.05). Male volunteers shed twice as much S. aureus as females (incidence rate ratio, 2.04; P=.013). The cold did not alter the efficacy of the barrier precautions. CONCLUSIONS: Scrubs reduced the spread of airborne S. aureus, independent of the presence of a rhinovirus-induced cold. Airborne dispersal of S. aureus during sessions in which participants wore surgical scrubs was not significantly different from that during sessions in which gowns and gowns plus masks were also worn.  相似文献   
100.
Forty-eight cases of tracheal agenesis have been reported to date. Previous authors have studied gross postmortem laryngeal specimens. Of 37 cases wherein laryngeal findings were mentioned, only 14 were reported to be abnormal. This report details two more cases of tracheal agenesis and includes a detailed histopathologic study of the laryngeal anomalies by serial horizontal section. Although one of these specimens appeared normal at autopsy, both were found to have several abnormalities when studied microscopically in horizontal section. Both have an elliptical cricoid cartilage, an abnormality originally discovered by one of us (G.F.T.) using the same technique.  相似文献   
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