CD4+ T-cell induction of Fas-mediated apoptosis in Burkitt's lymphoma B cells

Cytotoxic function of CD4+ Th1 cells is mediated by Fas (CD95, APO-1) and its ligand (Fas ligand). Recent studies using nontransformed B cells and the Ramos Burkitt's lymphoma (BL) B-cell line cells show that CD40 ligation at the B-cell surface by activated, CD40 ligand (CD40L)- bearing, CD4+ T cells upregulates Fas expression on B cells and primes B cells for Fas-mediated death signals. In this work, we examine whether this CD4+ T-cell-dependent molecular pathway for Fas upregulation and B-cell apoptosis reflects a peculiarity of the Ramos B- cell line or is applicable to other Burkitt's tumors as well. In 5 of the 6 Epstein-Barr virus-negative BL cell lines examined, the cells constitutively express undetectable or low levels of Fas and are resistant to Fas-mediated signals induced by monoclonal anti-Fas antibody. All 6 of the BL cell line B cells upregulate Fas in response to CD40 ligation, and in 4 of the cases they become sensitive to Fas- mediated death signals. In one BL cell line, the cells are constitutively sensitive to Fas-mediated cytolysis and are unaffected by CD40 signals. Next, we applied these immunologic manipulations to cells from a refractory clinical sample and observed that the tumor cells could be induced to express Fas and undergo apoptosis in our system. These results establish CD4+ T cells and the Fas-Fas ligand system as important immune regulators of Burkitt's lymphoma B cells and indicate that the susceptibility of tumor cells to Fas-mediated death signals can be modulated by specific activation events at the cell surface.     

Methylthioadenosine phosphorylase deficiency in acute leukemia: pathologic, cytogenetic, and clinical features

Blast cells from 100 cases of acute leukemia were evaluated for the presence of methylthioadenosine phosphorylase (MTAase), an enzyme important in polyamine metabolism. Ten cases (10%) had undetectable levels of MTAase activity. Of the 10, 5 had acute lymphoblastic leukemia (ALL), 3 had acute myeloblastic leukemia (AML) and 2 expressed mixed lineage markers as determined by immunophenotyping. A relatively high frequency (38%) of MTAase deficiency was seen in ALL of T-cell origin. Nonmalignant hematopoietic cells from three patients with MTAase-deficient leukemias had readily detectable enzyme activity. Chromosomal abnormalities were detected in four of the seven MTAase- deficient cases in which karyotypic analysis was performed. No consistent karyotypic defect was apparent, and only one case displayed changes in chromosome 9, the putative location of the MTAase structural gene. The clinical findings among the enzyme-deficient cases were unremarkable except that all patients were male (P less than .01). Only one patient had "lymphomatous" features. We conclude that MTAase deficiency occurs in a wide variety of acute leukemias, that the lack of enzyme activity is specific to the malignant cells, and that an increased incidence occurs in ALL of T-cell origin. Furthermore, no specific gross chromosomal abnormality is associated with the enzyme deficiency. The marked male predominance in patients with MTAase- deficient acute leukemias suggests involvement of the X chromosome in the loss of enzyme activity. The absence of MTAase in some leukemias may be therapeutically exploitable.     

Significance of Some Non-Invasive Biomarkers in the Early Diagnosis and Staging of Egyptian Breast Cancer Patients

Introduction: Breast cancer is one of the most relevant malignancies among women. Early diagnosis and accurate staging of breast cancer is important for the selection of an appropriate therapeutic strategy and achieving a better outcome. Aim: This study aimed to explore the significance of some non-invasive biomarkers in the early diagnosis and staging of Egyptian breast cancer patients. Subjects and Methods: A total of 135 female patients with physically and pathologically confirmed breast cancer and 40 unrelated controls as well as 40 patients with benign breast mass were enrolled in this study. The malignant breast cancer group was further divided into four groups according to tumor size. Serum levels of carcinoembryonic antigen-related cell adhesion molecule-1 (CEACAM1), resistin and visfatin were determined by enzyme immunoassay. Results: Elevated levels of CEACAM1, resistin and visfatin were observed in breast cancer patients when compared with normal control and benign groups. The cutoff values, sensitivities and specificities of these biomarkers were appropriate for the discrimination of breast cancer from controls. Additionally, the serum levels of visfatin increased positively with tumor size and consequently with breast cancer stages. Conclusion: CEACAM1, resistin and visfatin are valuable in early diagnosis of breast cancer, with visfatin being preferentially used in staging.     

不同温度体外循环对血栓栓塞的影响

探讨不同温度体外循环中血小板血栓栓塞情况。方法将１８只猪均分为３组行体外循环。Ⅰ组,１８℃深度温停循环;Ⅱ组,２８℃中度低温体外循环;Ⅲ组,３７℃常温体外循环。用铟－１１１标记的自体血小板测定３组心、肺、脑、肝,脾、肾和体外循环设备的血栓栓塞情况。     

Dialyzer-dependent changes in solute and water permeability with bleach reprocessing

The effects of bleach reprocessing on the performance of high-flux dialyzers have not been comprehensively characterized. We compared the effects of automated bleach/formaldehyde reprocessing on solute and hydraulic permeability for cellulose triacetate (CT190) and polysulfone (F80B) dialyzers using an in vitro model. Dialyzers were studied after initial blood exposure (R0) and after 1 (R1), 5 (R5), 10 (R10), and 15 (R15) reuse cycles. Ultrafiltration coefficient (K(uf)), serial clearances, and/or sieving coefficients (SCs) of urea, creatinine, vancomycin, inulin, myoglobin, and albumin were determined. Urea, creatinine, and vancomycin clearances and SCs did not significantly differ from R0 to R15 with either dialyzer. Inulin clearances and SC also did not significantly change from R0 to R15 for the CT190. However, these same values for the F80B significantly increased (P < 0.05). The inulin clearance and SC values for the CT190 dialyzer were significantly higher than those for the F80B at all stages except R15. Myoglobin clearances significantly increased over 15 reuses for both dialyzers (P < 0.01). However, CT190 myoglobin clearances were significantly higher at all stages (R0 = 37.7 +/- 9.7; R15 = 52.5 +/- 8.8 mL/min) than the F80B (R0 = negligible; R15 = 41.3 +/- 16.5 mL/min; P < 0.01). Albumin pre- and postdialysis SCs significantly increased for both dialyzers (P < 0.01). K(uf) for R0 and R15 were 52.3 +/- 3.3 and 52.6 +/- 7.6 mL/h/mm Hg for CT190 (P = not significant) and 48.8 +/- 4.4 and 87.3 +/- 7.0 mL/h/mm Hg for F80B (P < 0.0001). We conclude that bleach reprocessing significantly increases larger solute and hydraulic permeability of high-flux cellulosic and polysulfone dialyzers. This effect is more pronounced for the polysulfone membrane. Until 10 reuses or greater, the removal of solutes greater than 1,500 d is significantly compromised with the polysulfone dialyzer used in this study.     

Using accelerometers to characterize recovery after surgery in children

Background

Assessment of recovery after surgery in children remains highly subjective. However, advances in wearable technology present an opportunity for clinicians to have an objective assessment of postoperative recovery. The aims of this pilot study are to: (1) evaluate acceptability of accelerometer use in pediatric surgical patients, (2) use accelerometer data to characterize the recovery trajectory of physical activity, and (3) determine if postoperative adverse events are associated with a decrease in physical activity.

Paget disease: MR imaging findings

Magnetic resonance (MR) images of 13 patients with Paget disease were reviewed, and findings were correlated with those from computed tomographic (CT) scans, radiographs, and, in two patients, surgical biopsy. MR imaging findings correlated with CT and radiographic findings of cortical thickening, increased size of bone, and coarse thickened trabeculae. Focal or diffuse decreased signal intensity, representing dense bone, was seen on images obtained with short and long repetition times (TRs) and echo times (TEs); high-signal foci, representing fat collections, were seen on short TR/TE images; and high-signal foci, representing fibrovascular marrow in active Paget disease, were seen on long TR/TE images. Complications of Paget disease-including basilar invagination, spinal stenosis, and sarcoma--were well identified on MR images. Although MR imaging is not generally used in diagnosis of Paget disease, the disease will be encountered more frequently as more MR imaging examinations are performed. An awareness of the range of findings in Paget disease is useful in evaluating MR images of the musculoskeletal and other systems.     

Chronic wrist pain: evaluation with high-resolution MR imaging

The diagnostic performance of magnetic resonance (MR) imaging in the evaluation of the triangular fibrocartilage complex and the intrinsic and extrinsic ligaments of the wrist was assessed in 43 patients with chronic wrist pain. Forty-one patients underwent correlative arthrography. Twenty-three patients underwent arthroscopy or arthrotomy or both. The normal anatomy of the triangular fibrocartilage and the intrinsic and extrinsic ligaments could be demonstrated effectively with MR imaging. MR imaging was effective in the evaluation of triangular fibrocartilage tears with a sensitivity of 1.0, a specificity of 0.93, and an accuracy of 0.95 when compared with arthrography; 0.89, 0.92, and 0.90, respectively, when compared with arthroscopy and arthrotomy. MR imaging could also be used effectively to evaluate tears of the intercarpal ligaments, particularly the scapholunate ligament. Disruptions of the extrinsic ligaments, articular cartilage defects, and subluxations of the distal radioulnar joint were also well demonstrated. MR imaging is an effective procedure in assessing patients with chronic wrist pain.