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Biomedical subjects

K Hirohata

Publications and source records attributed to K Hirohata.

At least 91 records · Page 5Linked to original sources
PubMed1984

Genu recurvatum: a complication of prolonged femoral skeletal traction.

Genu recurvatum is a rare complication of prolonged skeletal traction. The literature reports very few cases, the majority secondary to wire traction applied to the tibia in the treatment of femoral shaft fractures. A case of genu recurvatum in a 12-year-old girl as a complication of prolonged femoral skeletal traction was treated at the Kobe University Hospital. A proximal open wedge tibial osteotomy using iliac bone grafts was the surgical treatment initiated at the time of diagnosis. Follow-up after 1 year showed recurrence of the genu recurvatum. Early surgical intervention, prolonged casting and application of knee orthosis were all contributory factors in the recurrence of genu recurvatum in our patient. It should be emphasized that extreme care should be taken in treating femoral shaft fractures in children, especially those requiring wire traction in the tibia or femur, in order to prevent genu recurvatum.

Adolescent↗
PubMed1984

Bilateral peroneal nerve palsy secondary to posterior dislocation of the proximal tibiofibular joint in rheumatoid arthritis.

Bilateral peroneal nerve palsy due to posterior dislocation of the proximal tibiofibular joint in a 72-year-old rheumatoid patient is described. Operative findings showed thickening of the synovial membrane of the proximal tibiofibular joint and a neuroma at the peroneal nerve at the fibular head. The cause of posterior dislocation of this joint in the wake of rheumatoid inflammation is discussed.

Aged↗
PubMed1984

An electron microscopic study of the synovial-bone junction in rheumatoid arthritis.

The cellular characteristics of the rheumatoid synovial-bone junction (SBJ) were examined in the electron microscope. Large numbers of mononuclear inflammatory cells along the bone suggested the advance of the rheumatoid inflammatory lesion into bone tissue. The SBJ contained macrophage-rich and osteoclast-rich areas. The presence of the macrophage as a predominant cell type and the marked collagenolysis of the eroded bone matrix suggested that collagenase released by macrophages was responsible for a major portion of the bone erosion. The observation of osteoclasts with ruffled borders, containing free bone crystals in close contact with the bone, indicated that these osteoclasts were stimulated by the rheumatoid synovium. It seems likely that articular bone resorption depends upon the local host response to the macrophage and osteoclast in the rheumatoid joint.

Arthritis, Rheumatoid↗
PubMed1984

An immunoelectron-microscopic study of the immunoglobulin-synthesizing cells of the rheumatoid synovial membrane.

Immunoglobulin (Ig)-synthesizing cells were examined in the transitional areas of rheumatoid synovial membrane infiltrates, which are rich in lymphocytes undergoing blastic transformation, by an electron-microscopic immunoperoxidase-labeling technique. Peroxidase reaction products, indicating the presence of Ig, were initially observed in the perinuclear cisternae of lymphoblasts. These products were subsequently observed in the rough endoplasmic reticulum in parallel to cellular maturation. In highly differentiated plasma cells Ig was rarely seen in the endoplasmic reticulum. Blastic lymphocytes containing Ig in transitional areas were in close association with macrophages, indicating that the transitional area is a major site of immunologic induction of Ig synthesis in rheumatoid synovial membrane.

Arthritis, Rheumatoid↗
PubMed1984

Use of the Wagner apparatus in the treatment of compound fractures with segmental bone loss.

Treatment of non-union of long bone fractures with segmental bone loss is difficult problem. Fracture healing is commonly delayed due to the severe associated soft tissue injuries, deep wound infections and poor osteogenesis. The slow healing time often necessitates prolonged joint immobilization resulting in joint stiffness. In order to obtain satisfactory fracture union without adjacent joint contractures, the Wagner apparatus in conjunction with massive cancellous bone grafting has been employed at the Kobe University Hospital. Autogenous cancellous grafts provide a scaffolding for rapid vascular ingrowth and viable osteoblasts for osteogenesis. Graft incorporation and fracture union can be monitored by serial radiographs and radioisotope studies.

Adult↗
PubMed1984

Electron and immunoelectron microscopic investigation of basal lamina thickening in synovial capillaries and post-capillary venules in rheumatoid arthritis.

Capillaries and post-capillary venules in the synovium obtained from 12 rheumatoid arthritis (RA) patients have been investigated by electron microscopy and immunoelectron microscopy with a monoclonal antibody against human type IV collagen, which is one of the major basal lamina (BL) components. The level of BL thickening in RA synovial vessels is roughly parallel with that of cellular exudation. The BL thickening may be due to excessive production of BL components, in which the accelerated rate of death and replenishment of endothelial cells and pericytes plays an important role. These cells may not only produce a single layer of BL in their life-time but also produce excessive amounts of BL components to make several layers in their life-time.

Adult↗
PubMed1984

Role of the fibula in weight-bearing.

To investigate the weight-bearing function of the fibula, weight-loading experiments were performed on autopsy specimens. With the ankle joint in neutral position, the weight distribution to the fibula amounted to 6.4%. With dorsiflexion of the ankle joint, the weight on the fibula increased. With plantar flexion of the ankle joint, the weight on the fibula decreased. Lateral and posterior loading of the tibia produced increased weight on the fibula. With eversion of the ankle joint, the weight on the fibula increased. The weight-bearing function increased with augmentation of the tibiofibular articular angle. These characteristics of the fibular weight-bearing function should be considered carefully in the treatment of the knee joint or the fibula.

Adolescent↗
PubMed1983

Interaction of polymorphonuclear leukocytes with immune complexes trapped in rheumatoid articular cartilage.

When rheumatoid articular cartilage samples were incubated with normal polymorphonuclear leukocytes (PMN) in vitro, large numbers of PMN were seen attached to the articular surface. As observed by electron microscopy, significant numbers of these cells invaded the cartilage tissue and phagocytosed amorphous material which presumably contained immune complexes. In control cartilage from osteoarthritic, pyogenic, and normal subjects, only a few PMN were attached to the articular surface after incubation with PMN. These results demonstrate that immune complexes trapped in the superficial region of the rheumatoid articular cartilage may play an important role in the destruction of cartilage by the release of lysosomal enzymes from PMN.

Antigen-Antibody Complex↗
PubMed1983

Inhibition of concanavalin A-induced phosphatidylinositol turnover and lysosomal enzyme release by cyclic AMP-elevating agents in rat peritoneal macrophages.

When rat peritoneal macrophages were stimulated with concanavalin A (Con A), phosphatidylinositol (PI) turnover was rapidly induced and concomitantly N-acetylglucosaminidase was released. These two reactions were markedly inhibited by prostaglandin E1, which elevated the cellular cyclic AMp levels. This effect was mimicked by dibutyryl cyclic AMP. These results suggest that the elevation of the cellular cyclic AMP levels might play a role in the inhibition of the early stages of Con A-induced activation of macrophages through the inhibition of PI turnover.

Acetylglucosaminidase↗
PubMed1983

The role of phosphatidylinositol turnover in initiation of prostaglandin biosynthesis in concanavalin A-induced activation of rat peritoneal macrophages.

When macrophages were stimulated by concanavalin A (50 micrograms/ml) in the presence of 32Pi and 3H-arachidonic acid (AA), rapid incorporation of these radiolabeled substances into phosphatidylinositol (PI) and phosphatidic acid (PA) were induced within 10 min. The pool of PI and PA incorporating 3H-AA was the same as that of PI and PA which incorporated 32P. However, significant increase in incorporation of 32P and 3H-AA did not occur in phosphatidylcholine, phosphatidylethanolamine or phosphatidylserine within this time interval as compared with control levels. These results indicate that PI turnover might play a role in the initiation of prostaglandin biosynthesis in the early stages of macrophage activation induced by concanavalin A.

Animals↗
PubMed1983

[T gamma lymphocytes in rheumatoid synovial membrane].

The proportion of T lymphocytes with receptors for the Fc portion of IgG (T gamma cells), revealed by mixed rosette assay, was determined in the synovial membrane and peripheral blood of 11 patients with rheumatoid arthritis. The percentage of T gamma cells in the lymphocytic infiltration of rheumatoid synovium was significantly lower than that found in peripheral blood (p less than 0.005). There was no significant difference between the percentage of T lymphocytes in the synovial tissue and that in peripheral blood. Depressed supressor activity of T lymphocytes in rheumatoid synovial membrane might lead B-lymphocytes to blastic transformation to the plasma cell series with consequent production of large amounts of immunoglobulins in the joint.

Adult↗
PubMed1983

Diagnosis of recurrent traumatic anterior subluxation of the shoulder.

Recurrent traumatic anterior subluxation of the shoulder has been infrequently documented. Subluxations have usually been included in reports of recurrent dislocation of the shoulder. There has also been confusion between traumatic and atraumatic subluxation. The authors diagnosed 45 cases of recurrent traumatic anterior subluxation of the shoulder at Kobe University Hospital during an eight-year period. Most patients were injured during sports activities. Patients complained of severe pain with episodes of locking when the shoulder was in abduction, external rotation, and hyperextension. Reduction could be accomplished by the patient. Arthrography demonstrates leaking of contrast medium on the anteroposterior view, and a detached labrum is noted on the posterior tangential view. Arthroscopy reveals Bankart lesions consisting of a ruptured capsule, detached labrum, and erosion of glenoid cartilage. Thirty-five of the patients underwent surgery, including Bankart and Putti-Platt reconstructions. Symptoms were relieved in all patients.

Adolescent↗
PubMed1982

Histologic and histochemical investigation of Gaucher cells.

Electron microscopic investigations suggest that morphologically, Gaucher cells and histiocytes are very similar. The fact that there are tubular elements in the lysosomes strongly suggests the possibility of lysosomes as the precursors of Gaucher bodies. By means of the lectin staining methods, the localization of glucocerebroside is clearly demonstrable in Gaucher cells. Lectin staining is the significant diagnostic feature of both Gaucher's and Krabbe's diseases.

Biopsy↗