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101.
The current article reviews the most recent literature addressing the definitions, ethical considerations, and potential strengths and limitations of online therapy. In addition, a framework is provided for how to conceptualize and categorize different aspects of online therapy for research purposes. Relevant studies of both online and face-to-face therapy as well as suggestions for future research are outlined.  相似文献   
102.
103.
HYPOTHESIS: En bloc esophagectomy (EBE) provides improved survival over transhiatal esophagectomy (THE) in patients with similarly sized transmural tumors (T3) and lymph node metastases (N1). DESIGN: A retrospective case-control study of 2 methods of esophageal resection for cancer. SETTING: University hospital (tertiary referral center for esophageal disease). PATIENTS: There were 49 patients (27 who underwent EBE and 22 who underwent THE) with similar T3 N1 disease and the following matched criteria: tumors of similar size and location, more than 20 lymph nodes in the surgical specimen, R0 resection, no previous chemotherapy or radiation therapy, and follow-up until death or for a minimum of 5 years.Main Outcome Measure Survival adjusted for differences in demographic and patient characteristics. RESULTS: The number of nodes harvested was greatest after EBE vs THE (median, 52 vs 29 [range, 21-85 vs 20-60]; P<.001). The median number of involved nodes was similar after EBE vs THE (median, 5 vs 7 [range, 1-19 vs 1-16]). The only 2 independent factors that affected survival in a Cox analysis were the number of involved lymph nodes (P =.01) and the type of resection (P =.03). Patients who underwent EBE had a survival benefit over those who underwent THE (P =.01). The survival benefit of EBE was seen only in patients with fewer than 9 involved lymph nodes (P<.001). CONCLUSION: En bloc esophagectomy confers a better survival than THE in patients with T3 N1 disease and fewer than 9 lymph node metastases.  相似文献   
104.
In previous rat studies, the use of mixed allogeneic chimerism (MAC) to induce host tolerance to hind limb allografts has resulted in severe graft-versus-host disease (GVHD). The purpose of this study was to determine if immunocompetent cells in bone marrow (BM) and/or lymph nodes (LNs) of transplanted limbs were responsible for inducing GVHD in mixed chimeric hosts. [ACIWistar Furth] chimeric rats received ACI hind limbs that were non-irradiated, irradiated (1050 cGy) or lymphadenectomized. Rejection, GVHD and donor chimerism was assessed. Chimeric hosts rejected none of their limbs. However, hosts of non-irradiated hind limbs succumbed to GVHD 22.4±0.8 days after transplantation. In contrast, chimeras that received irradiated or lymphadenectomized ACI hind limbs showed no clinical or histological signs of GVHD at 5 months. We conclude that mixed chimeric hosts are susceptible to GVHD due to the immunocompetent cell load provided by the LNs, not the BM, of hind limb allografts.Abbreviations BM Bone marrow - CPM Counts per minute - CTA Composite tissue allograft - FACS Fluorescence activated cell sorter - FITC Fluorescent iso-thiocyanate - GVH Graft-versus-host - GVHD Graft-versus-host disease - HVG Host-versus-graft - LN Lymph node - MAC Mixed allogeneic chimerism - MHC Major histocompatibility complex - MLR Mixed lymphocyte reaction - MoAb Monoclonal antibody - PBL Peripheral blood lymphocytes - SEM Standard error of mean - TBI Total body irradiation - TCD T-cell depletion/T-cell depleted - TCR T-cell receptor  相似文献   
105.
PURPOSE: There is now convincing evidence that prostate cancer cells lack the ability to produce and accumulate citrate. Using magnetic resonance spectroscopy imaging (MRSI), regions of absent or low citrate concentration in the prostate can be visualized at a resolution of a few mm. This new advancement provides not only a tool for early diagnosis and screening but also the opportunity for preferential targeting of radiation to regions of high tumor burden in the prostate. The differences in the shape and location of the prostate between MRSI imaging and treatment have been the major obstacle in integrating MRSI in radiation therapy treatment planning. The purpose of this study is to develop a reliable method for deforming the prostate and surrounding regions from the geometry of MRSI imaging to the geometry of treatment planning, so that the regions of high tumor burden identified by the MRSI study can be faithfully transferred to the images used for treatment planning. METHODS AND MATERIALS: Magnetic resonance spectroscopy imaging studies have been performed on 2 prostate cancer patients using a commercial MRSI system with an endorectal coil and coupling balloon. At the end of each study, we also acquired the MRI of the pelvic region at both the deformed state where the prostate is distorted by the endorectal balloon and the resting state with the endorectal balloon deflated and removed. The task is to find a three-dimensional matrix of transformation vectors for all volume elements that links the two image sets. We have implemented an optimization method to iteratively optimize the transformation vectors using a Newton-Ralphson algorithm. The objective function is based on the mutual information. The distorted images using the transformation vectors are compared with the images acquired at the resting conditions. RESULTS AND DISCUSSION: The algorithm is capable of performing the registration automatically without the need for intervention. It does not require manual contouring of the organs. By applying the algorithm to multiple image sets of different patients, we found a good agreement between the images transformed from those acquired at the deformed state and those acquired at resting conditions. The computation time required for achieving the registration is in the range of a half-hour (for image size: 256 pixels x 256 pixels x 25 slices). However, the space of registration can be restricted to speed up the process. CONCLUSION: In this article, we described a three-dimensional deformable image registration method to automatically transform images from the deformed imaging state to resting state. Our examples show that this method is feasible and useful to the treatment planning system.  相似文献   
106.
Congenital ptosis and amblyopia: a retrospective study of 130 cases   总被引:3,自引:0,他引:3  
PURPOSE: To provide supplementary data on the association between congenital ptosis and amblyopia. METHODS: In a retrospective chart study of 130 patients whose congenital ptosis was surgically corrected between 1987 and 1999, 27 (20.8%) had strabismus and 30 (23%) had amblyopia. In 9 patients (6.3%), it was not attributable to any cause except ptosis. RESULTS: There was a high incidence (6.9%) of amblyopia in patients with congenital ptosis. CONCLUSION: We recommend early examination and follow-up of patients with congenital ptosis to diagnose and treat any subsequent amblyopia. Surgery may be indicated should stimulus deprivation amblyopia develop.  相似文献   
107.
PURPOSE: The action spectrum of ultraviolet radiation mainly responsible for melanoma induction is unknown, but evidence suggests it could be ultraviolet A (UVA), which has a different geographic distribution than ultraviolet B (UVB). This study assessed whether melanoma mortality rates are more closely related to the global distribution of UVA or UVB. METHODS: UVA and UVB radiation and age-adjusted melanoma mortality rates were obtained for all 45 countries reporting cancer data to the World Health Organization. Stratospheric ozone data were obtained from NASA satellites. Average population skin pigmentation was obtained from skin reflectometry measurements. RESULTS: Paradoxically, melanoma mortality rates decreased with increasing UVB in men (r = -0.48, p < 0.001), and women (r = -0.57, p < 0.001), and with increasing UVA in both sexes. By contrast, rates were positively associated with increasing UVA/UVB ratio in men (r = + 0.49, p < 0.001) and women (r = + 0.55, p < 0.001). After multiple adjustment that included controlling for skin pigmentation, only UVA was associated with melanoma mortality rates in men (p < 0.02) with a suggestive but non-significant trend present in women (p = 0.12). CONCLUSIONS: UVA radiation was associated with melanoma mortality rates after controlling for UVB and average pigmentation. The results require confirmation in observational studies.  相似文献   
108.
Stereotactic Radiosurgery (SRS) has evolved as a unique discipline that combines aspects of both surgery and radiation oncology. Technological developments in the past few decades have provided a wide array of treatment techniques, including (i) the Gamma Knife; (ii) Linac-based stereotactic techniques using circular collimators or using micro multileaf collimators (mMLCs); (iii) the Cyber Knife, using an x-band linac mounted on a robotic arm; and (iv) serial and spiral tomotherapy. This paper provides a review of the treatment planning methods for stereotactic radiosurgery. Because of the differences in planning strategies used for each SRS technique, this paper will provide both a general review of the pre-requisites and common features of SRS treatment planning and the planning techniques specific to each of the SRS techniques.  相似文献   
109.
The actual incidence of true multicentric glioblastoma multiforme (GBM) varies between 2.4 and 4.9% of all GBMs. True multicentric tumors are described as widespread lesions in different lobes or hemispheres, which cannot be explained by spreading along the cerebrospinal fluid or blood pathways. We present here a case of multicentric GBM identified with positron emission tomography. CASE REPORT: A 73-year-old woman with sudden onset headaches, balance problems, and one episode of syncope was diagnosed as having an irregular, contrast-enhancing, space-occupying lesion in the left-temporal-parietal region on magnetic resonance imaging (MRI). The tissue diagnosis was confirmed as GBM, and she received stereotactic radiosurgery using the Leksell Gamma Knife (Elekta Instruments, Atlanta, GA). A 3-month, follow-up, MRI scan showed a remarkable decrease in the size of the contrast-enhancing area that was targeted during radiosurgery. A suspicious area of enhancement was detected on the right side, although no surrounding edema was evident. Fluorodeoxyglucose (FDG)-PET scanning revealed a large irregular neoplasm extending from the inferior left-temporal lobe into the deep parietal lobe with extremely intense FDG uptake, suggesting a very aggressive tumor. A smaller lesion was also discovered in the deep right-frontal lobe, representing a second neoplastic focus. The patient refused any further treatment. CONCLUSION: PET scans, in conjunction with MRI scans, allow for the best possible and most comprehensive diagnosis and treatment plans.  相似文献   
110.
The integrin VLA-4 has been shown to play a key role in the entry of antigen-specific T cells into the CNS during autoimmune demyelination. Treatment of animals with experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis, with antibodies to VLA-4 is known to suppress acute disease. In the present study, a synthetic antagonist of VLA-4 (TBC 3486) was injected subcutaneously into mice adoptively sensitized for chronic relapsing EAE. TBC 3486 was administered daily for 14 days at early (before acute signs) and late time points (during chronic disease). Early treatment led to marked delay in disease onset and reduction in clinical severity and demyelination. After termination of treatment, clinical severity remained lower than in controls for more than 1 week. TBC 3486-treated animals showing no clinical signs (at the height of disease in controls) displayed moderate levels of inflammation but little damage to myelin. Late administration of TBC 3486 to animals with chronic EAE had no effect clinically. Immunocytochemistry and Western blotting of CNS tissue from acutely treated animals supported a moderate shift toward a Th2-type cytokine profile after treatment. Thus, TBC 3486 effectively delayed and reduced the acute (but not chronic) phase of EAE, and this amelioration correlated with changes in the inflammatory molecule profile.  相似文献   
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