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This study was designed to directly compare the accuracy, reproducibility, and efficiency of three methods commonly used to measure blood-stage malaria parasite density from Giemsa-stained blood films. Parasites and white blood cells (WBCs) were counted in 154 thick films by two independent microscopists. Forty-six slides were read by counting parasitized red blood cells (RBCs) in the thin film. Using these same slides, parasites were again counted by two independent microscopists using an ocular grid. Overall, parasite densities were significantly lower and discrepancy between readers was higher when using the grid method compared to the WBC method, but there was no difference when compared to the RBC method. When one reader who had difficulty with the grid method was excluded, the discrepancy between readers was equivalent for the three methods. Densities and discrepancy between readers were indistinguishable when parasites were counted until 200 or 500 WBCs. Counting beyond 200 WBCs may not significantly improve parasite density measurements. Using an ocular grid directly measures parasites per volume rather than using a WBC per microliter conversion factor and eliminates the need to switch from the thick film to the thin film for high parasitemias. However, significant differences in densities measured by the grid method and the WBC method need to be evaluated.The opinions or assertions contained herein are the private views of the author, and are not to be construed as official, or as reflecting true views of the Department of the Army or the Department of Defense  相似文献   
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BACKGROUND: Lymph node involvement is one of the most significant prognostic factors of patients with rectal cancer. However, the distribution of mesorectal lymph nodes is not well known. This study was designed to assess lymph nodes in the mesorectum and to evaluate the correlation between the volume and weight of the mesorectum and the number of lymph nodes. METHODS: The mesorectums of 20 human cadavers were studied. The volume and weight of the superior rectal mesentery, superior mesorectum and inferior mesorectum were measured. Lymph nodes were sought by manual dissection and were submitted for histological examination. The correlation between the number of lymph nodes and the volume and weight of the mesorectum was evaluated by non-parametric Spearman test. RESULTS: A total of 178 lymph nodes were identified. The mean number of lymph nodes per specimen was 9.2 +/- 4.5. The lymph nodes were mostly smaller than 3 mm and located in the superior and posterior parts of the mesorectum. A positive correlation was found between the number of mesorectal lymph nodes and the volume and weight of the mesorectum. The number of lymph nodes in the superior rectal mesentery was independent of its volume and its weight. CONCLUSIONS: Mesorectal lymph nodes are mainly located above the peritoneal reflection within the posterior mesorectum. The positive correlation between the volume or the weight of the mesorectum and the number of mesorectal lymph nodes should be considered as a possible means to determine the minimum number of mesorectal lymph nodes required for histological examination.  相似文献   
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Primary leiomyosarcoma of bone is a rarely reported tumor of elderly subjects. It usually shows an aggressive osteolytic pattern on plain radiographs and involves predominantly the metaphyses of long bones. We report a case of primary leiomyosarcoma of bone, which is atypical by its epiphyseal location, a non-aggressive pattern on plain radiographs and its MR imaging features.  相似文献   
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STUDY AIM: The aim of this retrospective study was to report three cases of retrorectal vestigial cyst in adults. PATIENTS AND METHOD: From 1977 to 1999 retrorectal vestigial cyst (RVC) was diagnosed in our department in three women who were 28, 57 and 53 years of age, respectively. RVC was revealed by either pain (n = 2) that occurred in one case in a pregnant woman, or acute intestinal obstruction (n = 1). The patients were operated on using a perineal approach in two cases and an abdominal approach in one case. RESULTS: One epidermoid cyst and two mixed cysts without any sign of malignancy were observed. Postoperative follow-up was simple in two patients, while complications occurred in the third one via an uretero-vaginal fistula which required uretero-vesical reimplantation. The first two patients, reviewed after a 1-year follow-up, had no functional trouble and no sign of recurrence. CONCLUSION: Retrorectal vestigial cysts are very rare tumors with a risk for degeneration. Computerized tomography on nuclear magnetic resonance and endorectal ultrasonography allow detection of their structure and topography and help guide their surgical approach. In the absence of malignancy, wide excision, if possible without opening of the cystic wall, leads to good results.  相似文献   
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This report addresses the difficult situation in which a patient or surrogate decision maker wishes cardiopulmonary resuscitation to be attempted even though the physician believes that resuscitation efforts would be futile. It also reviews current controversies surrounding the subject of do-not-resuscitate (DNR) orders and medical futility, discusses the complex medical, legal, and ethical considerations involved, and then offers recommendations as a guide to clinicians and ethics committees in resolving these difficult issues. Conflicts over DNR orders and medical futility should not be resolved through a policy that attempts to define futility in the abstract, but rather through a predefined and fair process that addresses specific cases and includes multiple safeguards. As it examines these issues, the report focuses on the Veterans Health Administration (VHA). Current national VHA policy constrains physicians from entering a DNR order over the objection of a patient or surrogate even if the physician believes cardiopulmonary resuscitation to be futile. The VHA National Ethics Committee recommends that VHA policy be changed to reflect the opinions expressed in this report. The National Ethics Committee, which is composed of VHA clinicians and leaders, as well as veterans advocates, creates reports that analyze ethical issues affecting the health and care of veterans treated in the VHA, the largest integrated health care system in the United States. This report does not change or modify VHA policy.  相似文献   
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