Detection of bone marrow infiltration of lymphoma cells by fluorescence in situ hybridization

BACKGROUND: It is sometimes difficult to detect the bone marrow infiltration of lymphoma cells, because lymphoma cells are not distinguishable from normal lymphocytes due to the similarity of their phenotype. METHODS: Bone marrow involvement of 17 samples of 15 patients with follicular lymphoma, whose lymphoma cells were confirmed to harbor the translocation of chromosome14q32, were examined by microscopic analysis of bone marrow smear and biopsy, flow cytometorical analysis (FCM), chromosomal analysis of G-banding and fluorescence in situ hybridization (FISH). FISH was performed using a probe, which detects the split of IGH gene on 14q32. RESULTS: The positivity of FISH was highest among these methods and FISH was able to detect the bone marrow involvement in one case who was defined as negative by bone marrow biopsy. CONCLUSIONS: FISH can be used for detection of bone marrow involvement of malignant lymphoma that carries chromosomal rearrangement involving 14q32.     

Studies on immune adherence (C3b) receptor activity of human erythrocytes: relationship between receptor activity and membrane osmotic fragility

Although human erythrocytes (E) possess C3b receptors (C3b-R), their in vivo functions are unknown. We had observed that E from patients with immune complex diseases had defective or impaired C3b-R activity when circulating immune complexes (CIC) could be demonstrated. This phenomenon has been investigated in relation to membrane osmotic fragility of such E by a coil planet centrifugation (CPC) system. Osmotic fragility was defined by the hemolysis starting point (HSP), peak point (HPP) and end point (HEP) using NaCl osmotic gradient (150-30 mOsM) coiled tubes. It was observed that E with low C3b-R activity showed high osmotic fragility. Hemolysis of E with low C3b-R activity started at 104 +/- 8 mOsM (n = 133) compared to 97 +/- 3 mOsM (n = 18) of patients' E with normal C3b-R activity and 96 +/- 5 mOsM of E from normal healthy donors (n = 128). Furthermore, we observed that HSP shifted towards lower osmolarity with clinical and immunological improvement of disease activity after treatment with corticosteroids. When osmotic gradients were lower to 120-50 mOsM, 52 out of 116 E samples with low C3b-R activity separated into 2 E populations. In contrast, none of 18 E samples with normal C3b-R activity separated into 2 E populations. However, we observed broadened fragility patterns in these 18 E samples. Serial studies of C3b-R activity, osmotic fragility and the presence of CIC were performed in 7 patients. Improvement of disease activity was associated with increased C3b-R activity, decreased osmotic fragility and the disappearance of CIC.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of graded mechanical compression of rabbit sciatic nerve on nerve blood flow and electrophysiological properties

Entrapment neuropathy is a frequent clinical problem that can be caused by, among other factors, mechanical compression; however, exactly how a compressive force affects the peripheral nerves remains poorly understood. In this study, using a rabbit model of sciatic nerve injury (n = 12), we evaluated the time-course of changes in intraneural blood flow, compound nerve action potentials, and functioning of the blood–nerve barrier during graded mechanical compression. Nerve injury was applied using a compressor equipped with a custom-made pressure transducer. Cessation of intraneural blood flow was noted at a mean compressive force of 0.457 ± 0.022 N (±SEM), and the compound action potential became zero at 0.486 ± 0.031 N. Marked extravasation of Evans blue albumin was noted after 20 min of intraneural ischemia. The functional changes induced by compression are likely due to intraneural edema, which could subsequently result in impairment of nerve function. These changes may be critical factors in the development of symptoms associated with nerve compression.     

Small solid pseudopapillary tumor of the pancreas in a 32-year-old man: Report of a case

A solid pseudopapillary tumor (SPT) of the pancreas is a rare neoplasm that mainly occurs in young women. We herein report the case of a small SPT arising from the head of the pancreas in an asymptomatic 32-year-old man, plus a literature review of this tumor. A 32-year-old man was admitted to our department at Kumamoto University Hospital for the evaluation of a pancreatic mass. The tumor had central necrosis, which was poorly perfused on contrast-enhanced computed tomography (CT) and which had a high intensity on T2-weighted magnetic resonance imaging (MRI). Histology revealed the lesion to be a solid pseudopapillary tumor of the pancreas, with the characteristic pseudopapilla formation and central degeneration. However, no capsule formation was observed. The tumor was positive for CD56, CD10, α1-antitrypsin, α1-antichymotrypsin, β-catenin, and progesterone receptor. However, the tumor was negative for pancreatic hormones, chromogranin-A, carcinoembryonic antigen, and carbohydrate antigen 19–9. We diagnosed the patient to have an SPT based on these histological findings. Small-sized solid pseudopapillary tumors of the pancreas are being increasingly recognized because of the recent advances in CT and MRI. We should also consider SPT even if it occurs in a male when the tumor contains necrosis-suspected areas which are poorly perfused on contrast-enhanced CT with a high intensity on T2-weighted MRI.     

5-azacytidine, a chemotherapeutic drug, induces TRAIL-mediated apoptosis in mouse thymocytes in vivo

5-azacytidine (5AzC) is a cytidine analogue with two main effects on cellular conditions; DNA damage, resulting in apoptosis, and DNA hypomethylation, restoring normal growth control and differentiation. However, the molecular mechanism of 5AzC-induced apoptosis is not fully understood. The aim of the present study is to clarify this mechanism in mouse thymocytes in vivo. Ten-week-old, male C57BL/6J mice were injected with 5AzC (100 mg/kg) intraperitoneally, and thymuses were examined for apoptotic changes. In the 5AzC-treated thymus, increases of TUNEL-positive thymocytes and cleaved caspase-3 protein, both biochemical features of apoptosis, were detected. 5AzC-induced apoptosis was observed even in the thymuses of mice deficient in p53, a critical factor in the intrinsic apoptotic pathway, and mice with mutated Fas, a death receptor. Furthermore, levels of p53 and Fas proteins were unchanged in the thymus following 5AzC-treatment in wild-type mice. In the 5AzC-treated thymus, the level of cleaved caspase-8 protein, an initiator of the extrinsic apoptotic pathway, increased with the cleavage of its target protein, Bid. Moreover, the level of TRAIL protein, which induces apoptosis through the cleavage of caspase-8, robustly increased in the thymus treated with 5AzC. In conclusion, the 5AzC-induced apoptosis of thymocytes in vivo is implemented through the extrinsic pathway with the activation of TRAIL.     

Three-dimensional analysis of computed tomography-based navigation system for total knee arthroplasty: the accuracy of computed tomography-based navigation system

We evaluated the postoperative alignment of 37 primary total knee arthroplasties performed using a computed tomography–based navigation system (Vector Vision Knee 1.5; Brain Lab, Germany) with a new 3-dimensional analysis. The mean coronal femoral angle was 89.0° ± 1.4° (85.5°-92.8°), and the coronal tibial component was 89.2° ± 1.0° (87.4°-91.6°). The hip-knee-ankle angle was observed to be 178.2° ± 1.5° (173.9°-181.8°). The external rotational alignment of the femoral component relative to the surgical epicondylar axis was −0.5° ± 1.7° (−3.2° to 3.4°). The results demonstrated that a computed tomography–based navigation system provided a reasonably satisfactory component alignment. The discrepancy between the 2-dimensional and 3-dimensional evaluations was 1.0° ± 0.9° (0.1°-3.4°). Three-dimensional analysis is necessary to evaluate the accuracy of the navigation system.