TUMOR CELL PHAGOCYTOSIS AND CYTOTOXICITY OF LYMPHOBLASTOID CELLS FOLLOWING CONCANAVALIN A TREATMENT

Cell-to-cell interaction was investigated in various malignant tumor cells (human ovarial tumor, lung cancer, carcinoma of larynx and hamster melanoma cell) and in human lymphoblastoid cells (T-cell (MOLT-4 cell), thymoma cells and B-cells (Burkitt lymphoma cell)). Live lymphoblastoid cells did not adhere to the cell surfaces of tumor cells nor the lymphoblastoid cells were ingested by tumor cells wihout immunologic and specific treatment. Tumor cells as well as T-cells and B-cells had receptors to concanavalin A on their surfaces, and they showed marked cell binding of tumor cells and lymphoblastoid cells. Moreover, tumor cells that phagocytized lymphoblasts underwent marked cell destruction within 4 hours of cell binding. The cytolytic mechanism of the target tumor cell was probably related to contact with the lymphoblastoid cells and was increased by ingestive activity, and metabolic disturbance by lymphotoxin in tumor cells.     

Detection of alternatively spliced variant messages of Fas gene and mutational screening of Fas and Fas ligand coding regions in peripheral blood mononuclear cells derived from silicosis patients

Silicosis is clinically characterized not only by respiratory disorders but by immunological abnormalities such as the appearance of autoantibodies and complications of autoimmune diseases. Dysregulation of apoptosis, particularly in the Fas/Fas ligand (FasL) pathway, has been considered to play a role in the pathogenesis of autoimmune diseases. It has been found that serum soluble Fas (sFas) levels are elevated in silicosis patients (SIL) and the sFas message is dominantly expressed in peripheral blood mononuclear cells (PBMC) derived from these individuals. In the present study, one tried to detect alternatively spliced variant messages including typical sFas message and found four that were highly and frequently expressed, and which possess a signal peptide domain, but not transmembrane and signal transducing domains, in PBMC derived from SIL. Functional mutations were not detected in Fas and FasL genes in silicosis PBMC. Still, alternative spliced variants of the Fas gene including typical sFas message appear to play an important role in the immunological dysregulation in SIL.     

Elevated binding activity of CD8+ cells with phytohaemagglutinin by asbestos fibre in vitro.

Asbestos fibres are known to depress the mitogenic stimuli of phytohaemagglutinin (PHA) to lymphocytes. We examined effects of asbestos (chrysotile) fibre on the proliferation of PHA-stimulated lymphocytes and the PHA binding activity of lymphocytes in vitro. The incorporation of 3H-thymidine and the expression of interleukin-2 receptor were depressed when the cells were exposed to 50 micrograms/ml of chrysotile fibre. The PHA binding activity of lymphocytes was significantly enhanced after chrysotile fibre exposure, as compared with non-exposed group. These results indicate that the depression of PHA stimuli with chrysotile fibre was not due to blocking of PHA binding to lymphocytes. The enhancement of PHA binding activity by chrysotile fibre was observed on CD8+ but not on CD4+ cells. It is possible, therefore, that treatment of peripheral blood mononuclear cells with chrysotile fibre induces increased reactivity of CD8+ cells with PHA, and that intensely activated CD8+ cells suppress proliferation of lymphocytes.     

Early-stage rheumatoid arthritis: prospective study of the effectiveness of MR imaging for diagnosis

PURPOSE: To assess the effectiveness of magnetic resonance (MR) imaging for the diagnosis of early-stage rheumatoid arthritis (RA). MATERIALS AND METHODS: Fifty subjects (nine men and 41 women) with polyarthralgia who were suspected of having early-stage RA on the basis of clinical and radiographic findings were selected to undergo gadolinium-enhanced MR imaging of the hands. The MR imaging criterion for the diagnosis of early RA was bilateral enhancement in both wrists and/or the metacarpophalangeal and/or proximal interphalangeal joints. Follow-up continued until a final diagnosis was determined. Two patients left the study before the end of follow-up. RESULTS: Final diagnoses were established after a mean follow-up of 776 days: rheumatoid arthritis in 26 patients and nonrheumatoid disease in 22. Use of the MR imaging criterion yielded the correct diagnosis in 25 patients with RA and three false-positive results in three patients without RA. As compared with the traditional format and classification tree criteria of the American Rheumatism Association, the MR imaging criterion allowed detection of seven and six additional patients with true RA, respectively. CONCLUSION: The introduction of MR imaging into the diagnostic criteria for early RA may contribute to more accurate diagnosis in patients suspected of having RA and thus allow an earlier decision to start proper medication.     

Creation of individual ideally shaped stents using multi-slice CT: in vitro results from the semi-automatic virtual stent (SAVS) designer

To plan stent-grafting for thoracic aortic aneurysm with complicated morphology, we created a virtual stent-grafting program [Semi Automatic Virtual Stent (SAVS) designer] using three-dimensional CT data. The usefulness of the SAVS designer was evaluated by measurement of transformed anatomical and straight stents. Curved model images (source, multi-planer reconstruction and volume rendering) were created, and a hollow virtual stent was produced by the SAVS designer. A straight Nitinol stent was transformed to match the curved configuration of the virtual stent. The accuracy of the anatomical stent was evaluated by experimental strain phantom studies in comparison with the straight stent. Mean separation length was 0 mm in the anatomical stent [22 mm outer diameter (OD)] and 5 mm in the straight stent (22 mm OD). The straight stent strain voltage was four times that of the anatomical stent at the stent end. The anatomical stent is useful because it fits the curved structure of the aorta and reduces the strain force compared to the straight stent. The SAVS designer can help to design and produce the anatomical stent.Electronic Supplementary Material Supplementary material is available in the online version of this article at     

Magnetic resonance angiographic localization of the artery of Adamkiewicz for spinal cord blood supply

Background

The purpose of this study was to determine whether the artery of Adamkiewicz (ARM) can be detected by magnetic resonance angiography and to determine the usefulness of preoperative magnetic resonance angiography evaluation of the ARM.

Methods

Between April 2000 and December 2003, 120 patients underwent magnetic resonance angiography for detection of the ARM. The morphology of the anterior spinal artery at the ARM junction, as revealed by magnetic resonance angiography, in 99 patients in whom ARM was preoperatively detected was classified into the following three types: noncontinuation of the anterior spinal artery above the ARM junction (type A), continuation of the anterior spinal artery above and below the ARM junction (type B), and noncontinuation of the anterior spinal artery below the ARM junction (type C).

Results

The ARMs were detected in 99 (83%) of 120 patients, and from a total of 110 ARMs 105 (95%) originated from intercostal arteries branching from the left side and 94 (86%) originated between Th9 and Th11. Two ARMs were found in 11 (11%) of 99 patients in whom ARMs were detected. In 107 patients, who underwent magnetic resonance angiography to reveal the morphology of the anterior spinal artery at the ARM junction, the patterns of the anterior spinal artery were type A in 59 patients (55%), type B in 21 patients (20%), type C in 3 patients (3%) and not classified in 24 patients (22%). No spinal cord injury occurred in patients in whom the ARM had been preoperatively detected.

Conclusions

Preoperative detection of the ARM is possible by magnetic resonance angiography and is very useful for reducing the incidence of ischemic injury of the spinal cord.