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Biomedical subjects

M Kurosaka

Publications and source records attributed to M Kurosaka.

At least 73 records · Page 4Linked to original sources

Lipid microspherules in synovial fluid of patients with pigmented villonodular synovitis.

We describe 2 patients with pigmented villonodular synovitis. In both patients, synovial fluids (SF) were characterized by the presence of abundant, strongly birefringent lipid microspherules, which appeared as Maltese crosses and were found both inside foam cells and free in the SF. Histologically, the synovial membranes showed pigmented villonodular synovitis, with aggregation of foam cells containing abundant lipid microspherules in their cytoplasm. Observation of numerous birefringent lipid microspherules and foam cells in SF may be a clue to the diagnosis of pigmented villonodular synovitis.

Adult↗

Knee arthroscopy using local anesthetic.

The purpose of this study was to examine the effectiveness and safety of local anesthetics (a mixture of lidocaine and bupivacaine) in knee arthroscopy. Local anesthetic agents were shown to be effective and safe, based on chart review and measurement of blood levels of the anesthetic drugs.

Adult↗

Electron microscopic study of HLA-DR and monocyte/macrophage staining cells in the rheumatoid synovial membrane.

We examined synovial membrane samples from 6 rheumatoid arthritis (RA) and 3 osteoarthritis patients and from 1 normal subject, by an immunoelectron microscopic technique using anti-HLA-DR (anti-Ia) and anti-monocyte/macrophage (63D3) monoclonal antibodies. In the lining layer, the type A macrophage-like cells were strongly DR+ and 63D3+, whereas the type B fibroblast-like cells were almost completely negative. Lymphocyte-rich areas (containing more than 90% densely packed lymphocytes) showed weak and patchy DR staining of the lymphocytes. In these areas, 3-5% of the cells were macrophage-like cells which were 63D3-, a type of staining compatible with that of the interdigitating cell (IDC). In the plasma cell-containing (transitional) areas, many strongly DR+ macrophage-like cells were observed in close contact with lymphocytes and plasma cells. Ten to twenty percent of these cells were 63D3-, which suggests that they were IDC. Cells with the structural appearance of IDC were most frequently seen in those transitional areas which contained elevated concentrations (50-70%) of lymphocytes. In uninfiltrated interstitial areas, approximately 50% of the cells stained strongly with both anti-DR and 63D3 antibody, indicating that they were cells of monocyte/macrophage lineage, presumably histiocytes. This investigation has demonstrated the presence of the DR antigen in the RA synovial membrane on 1) phagocytic cells of the lining area, 2) lymphocytes and small numbers of IDC-like cells in dense, lymphocyte-rich areas, 3) large numbers of macrophage-like cells, of which some had the morphologic appearance of IDC, in transitional or plasma cell-containing areas, and 4) histiocytic cells in uninfiltrated interstitial areas. The observation of large numbers of DR+ macrophages and IDC-like cells in close contact with lymphocytes and plasma cells in the RA synovial membrane emphasizes their role in an active immune response. The observation of substantial numbers of potentially immunocompetent, DR+ histiocytic cells in uninfiltrated regions of the synovial membrane suggests that such cells may play a role in the progression of the synovial inflammatory reaction.

Arthritis, Rheumatoid↗

Augmentation of anterior cruciate ligament reconstruction in dogs with prostheses of different stiffnesses.

The purpose of this study was to investigate the biological and biomechanical properties of anterior cruciate ligament (ACL) reconstruction augmented with Dacron prostheses of three different stiffnesses. The ACLs of 36 adult mongrel dogs were removed and the ligament was reconstructed. In 18 dogs, one knee was reconstructed with patellar tendon alone, and the contralateral knee with Dacron augmented patellar tendon. In the remaining 18 dogs, reconstruction was with Dacron augmented patellar tendon with Dacron alone being used for the contralateral control knee. Death was 3 months after surgery, and the reconstructions were examined biologically and biomechanically. The mechanical data were compared with immediate postoperative data obtained from 45 reconstructed fresh cadaveric knees. Tensile testing demonstrated that an increase in failure load was found when the implanted patellar tendon graft was compared with the cadaveric reconstruction. The strength of the Dacron augmented reconstruction showed little change while the Dacron alone graft decreased in strength during the period of implantation. No clear difference was found between the performance of augmentation devices of different stiffnesses. Microangiography showed that grafts were totally revascularized in patellar tendon alone, but not well revascularized in Dacron augmented patellar tendon and Dacron alone reconstruction. The presence of the Dacron appeared to have an adverse effect on revascularization.

Animals↗

Immunoelectron microscopic study of the distribution of T cell subsets in rheumatoid synovium.

The perivascular mononuclear cell collections of the rheumatoid synovium were examined both at the light and electron microscopic level by an immunoperoxidase staining technique using monoclonal antibodies directed against T cell subsets. These accumulations were variable in composition and size, not only in specimens from different patients but in the same specimen. Some areas (lymphocyte-rich areas) contained mainly small lymphocytes in clusters and others (transitional areas) contained blast cells, macrophages, and plasma cells in addition to lymphocytes. The percentage of T4 staining cells correlated positively and the percentage of T8 staining cells correlated negatively with the percentage of lymphocytes in any given area. In contrast, the percentage of T4 cells correlated negatively and the percentage of T8 cells correlated positively with the percentage of macrophage-like cells in these areas. Approximately 80% of the total lymphocytes, both in the lymphocyte-rich areas and transitional areas, were T lymphocytes (OKT3 staining). In lymphocyte-rich areas, helper/inducer T lymphocytes (OKT4 staining) were predominent over suppressor/cytotoxic lymphocytes (OKT8 staining), and in such areas the mean T4:T8 ratio was 2.9. Macrophage-like cells were seen only in small numbers in this type of area. In the transitional areas, suppressor/cytotoxic lymphocytes (OKT8 staining) predominated over helper/inducer lymphocytes (OKT4 staining). In such areas the mean T4:T8 ratio was 0.8. The T8 cells in the transitional areas tended to be large in size and often had a blastic appearance, and the abundant macrophage-like cells infiltrating these areas were frequently in close contact with T8 lymphocytes. These findings indicate that the ratio of T4 to T8 lymphocytes in rheumatoid synovium varies with the type of area examined. In lymphocyte-rich collections, made up largely of quiescent small lymphocytes, T4 cells are predominant. In areas of apparent immunological reactivity, T8 cells are predominant. It is suggested that T8 cells proliferate in immunologically active areas of the synovium as a result of local stimulation of a T cell-mediated immune response.

Animals↗

Phenotype of the accessory cell necessary for mitogen-stimulated T and B cell responses in human peripheral blood: delineation by its sensitivity to the lysosomotropic agent, L-leucine methyl ester.

The lysosomotropic compound L-leucine methyl ester (Leu-OMe) was utilized to delineate the phenotype of the accessory cells involved in human B and T cell activation in vitro. Leu-OMe was shown to cause lysosomal disruption and selective death of human monocytes (M phi). After 30-45 minute incubations with this agent, human peripheral blood mononuclear cells (PBM) were nearly completely depleted of M phi. Associated with this M phi depletion, PBM were rendered unresponsive to a variety of T and B cell mitogens including the plant lectins phytohemagglutinin, concanavalin A, and pokeweed mitogen as well as the oxidative mitogens sodium periodate and neuraminidase plus galactose oxidase. Leu-OMe mediated loss of responsiveness was the result of a selective loss of an accessory cell necessary for each of these responses since reconstitution was accomplished by the addition of a M phi-enriched adherent cell population. While intact adherent cells could reconstitute responsiveness, crude M phi supernatants or highly purified human IL 1 alone were ineffective. Further identification of the Leu-OMe sensitive accessory cell indicated that it was entirely contained within the fraction of the adherent population identified by the monoclonal anti-M phi antibody, 63D3. The mechanism by which Leu-OMe Killed M phi was dependent on the lysosomal content of these cells, since agents that altered lysosomal enzyme activity such as chloroquine or NH4Cl protected M phi from Leu-OMe. Thus, the selective killing of M phi by Leu-OMe appeared to relate to the characteristically rich endowment of lysosomes within these cells. These results support the conclusion that a lysosome-rich, leucine methyl ester-sensitive, intact M phi identified by the monoclonal anti-M phi antibody 63D3 is the circulating accessory cell required for mitogen-triggered human B and T cell activation.

Adult↗

A true aneurysm of the femoral artery in acromegaly.

We report on an acromegalic patient who developed a true aneurysm in the right femoral artery. Plain computed tomography (CT) showed a soft tissue mass with low density adjacent to the right femoral artery. T1-weighted magnetic resonance (MR) images exhibited the lesion with moderate hypointensity peripherally, and hypointensity centrally. T2-weighted images showed the lesion to have areas of hypointensity, moderate hyperintensity, and marked hyperintensity. Surgery revealed an ectasia of the common femoral artery and a true aneurysm from the lateral femoral circumflex artery.

Acromegaly↗

Ossified intramuscular hemangioma: multimodality imaging findings.

Whereas calcification of hemangiomas is common, ossification is unusual. Multimodality imaging findings of a rare case of an ossified intramuscular hemangioma in the calf of a 24-year-old woman are presented. Radiographic, computed tomographic, magnetic resonance (MR), scintigraphic, and histologic features of this case are reported. The radiologic differential diagnosis of an ossified mass in soft tissue is also discussed.

Adult↗

Periosteal chondroma presenting as a subcutaneous mass in the thumb.

We describe an unusual case of periosteal chondroma of the distal phalanx in the left thumb presenting as a subcutaneous mass in an 81-year-old woman. Magnetic resonance (MR) imaging demonstrated a subcutaneous lesion with hypointensity on T1-weighted images and marked hyperintensity on T2-weighted images, eroding the underlying cortical bone. Computed tomographic (CT) scans showed an erosive change in the dorsal cortex of the distal phalanx. Bone tumors arising from bone surface should be considered in the differential diagnosis of subcutaneous finger masses.

Aged↗