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BACKGROUND: Computer-assisted image analysis has been proposed for human hair growth studies. METHODS: The performances of Trichoscan, a commercially available automated system combining epiluminiscence microscopy with digital image analysis, developed for office-based hair growth measurements, have been evaluated comparatively on the same skin sites using standardized photographic equipment and calibrated processing for contrast-enhanced phototrichogram (CE-PTG) analysis. This reference method has been validated with scalp biopsies and histological examination of serial sectioning. RESULTS: Besides edge effects, hair fibres escaped the Trichoscan analysis for various reasons including, but not limited to, thickness, pigmentation, closeness and crossing. CONCLUSION: Most of these problems have been identified in the late 1980s and remain largely unsolved by the processing software that was evaluated in 2004. Therefore claims promoting the Trichoscan method for accurate hair measurements in clinical trials on scalp and body hair are not supported by the present investigation. The speed at which the analysis is performed is outweighed by the errors in signal detection. Therefore we suggest that improvements must be clearly documented before Trichoscan is established for quantified diagnostic purposes and detailed hair cycle monitoring during hair trials.  相似文献   
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The accurate estimation of the spin-spin relaxation time T2 is an important goal in magnetic resonance imaging particularly because it can be used for quantitative tissue characterization. The spin-spin relaxation time T2 may be estimated using multiecho pulse sequences, but the accuracy of the estimate is dependent on the fidelity of the spin-echo amplitudes, which may be severely compromised by rf pulse and static field imperfections. In this paper, the effects of static field inhomogeneities are investigated. The propagation of the errors introduced by off-resonance effects are analyzed through computer simulations and analytical solutions of the Bloch equations. A series of experiments performed on a simple tissue phantom using a whole-body imaging system operating at 6.35 MHz corroborates the simulation and analytical results. For accurate measurements of T2 using a whole-body imaging system it is necessary to correct for these inhomogeneities. A correction scheme which would enable a more accurate estimate of T2 is currently under investigation.  相似文献   
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Retrospectively we analyzed the histocompatibility data and clinical results of bone marrow transplantation in 51 patients who received marrow from unrelated donors (UD) from 1977 to 1987 at one of four UK BMT centers. We compared the results with those obtained in 51 transplants carried out at the same centers using HLA-identical (ID) sibling donors. Of the UD/recipient pairs 32 (63%) were serologically identical for HLA A, B, and DR antigens, and 37% showed varying degrees of mismatch. UD-BMT primary diagnoses were: severe aplastic anemia or Fanconi's anemia (n = 17), acute leukemia (n = 11), chronic myeloid leukemia (n = 21), and other conditions (n = 2). T cell depletion of the graft was associated with a significant improvement in survival in both UD and ID-BMT. Graft failure was more common in recipients of UD than of ID transplants (13 [25%] vs. 5 [10%] P = 0.05) but there was no significant difference in the frequency of acute or chronic graft-versus-host disease. Actuarial survival was superior for recipients of ID transplants (UD vs. ID: 49% vs. 78%, respectively, at 3 months; 32% vs. 63% at one year). Reduced survival for recipients of UD-BMT was confirmed in case control regression analysis (relative risk 3.0, P = 0.01). Nevertheless in patients whose only alternative is a partially mismatched family donor we think that UD-BMT is justified.  相似文献   
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Neck pain: a long-term follow-up of 205 patients   总被引:7,自引:0,他引:7  
Two hundred five patients with neck pain were evaluated clinically and roentgenographically for a minimum of 10 years after onset of symptoms. Seventy-nine percent had a decrease in pain, and 43% were free of pain; however, 32% had moderate or severe residual pain. Patients who had been injured and initially had severe pain were the most likely to have an unsatisfactory outcome; however, no other clinical features were of value in predicting the final result. The presence or severity of pain was not related to the presence of degenerative changes, the sagittal diameter of the spinal canal, the degree of cervical lordosis, or to any changes in these measurements over the evaluation period.  相似文献   
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Despite reports demonstrating the safety of laparoscopic donor nephrectomy (LDN) for pediatric recipients of renal transplants, recent evidence has challenged using LDN for recipients 5 years of age or younger. We retrospectively reviewed the records of all pediatric recipients of living donor renal transplants from September 2000 through August 2004. We compared those who received allografts recovered by LDN (n = 34) with those recovered by open donor nephrectomy (ODN, n = 26). Outcomes of interest included operative complications, postoperative renal function, the incidence of delayed graft function or episodes of acute rejection and long-term graft function. Donor and recipient demographic data were similar for the LDN and ODN groups. Serum creatinine and calculated creatinine clearance were not significantly different between groups both in the early postoperative period and at long-term follow-up (p > 0.142). Rates of delayed graft function and acute rejection did not differ between groups. Among recipients aged 5 years old or younger stratified by donor technique (9 LDN, 5 ODN recipients), no difference was noted in graft outcomes both early and long-term (p > 0.079). At our center, pediatric LDN recipients have graft outcomes comparable to those of ODN recipients. At experienced centers, we recommend continued use of LDN for pediatric recipients of all ages.  相似文献   
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