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Biomedical subjects

A Minami

Publications and source records attributed to A Minami.

At least 19 recordsLinked to original sources

Identification of macrophage migration inhibitory factor (MIF) in rat peripheral nerves: its possible involvement in nerve regeneration.

Macrophage migration inhibitory factor (MIF) is known as a pluripotent immunoregulatory cytokine involved in T-cell activation and inflammatory responses; however, no study on this protein in the peripheral nervous systems has been carried out. We here demonstrated for the first time expression of MIF mRNA and MIF protein in rat sciatic nerves by reverse transcription-polymerase chain reaction, Western blotting, and immunohistochemistry. Immunohistochemical analysis revealed positive staining of MIF, which was largely observed in Schwann cells. Furthermore, we examined MIF mRNA expression in the sciatic nerves by Northern blot analysis in the case of nerve transection. In both proximal and distal segments, the level of MIF mRNA started to increase 12 h after the nerve transection. The level remained high from 24 h up to day 7 after the injury. During the period from days 14 to 21, MIF mRNA sharply decreased to the pre-transection level. In immunohistochemistry, positive staining of MIF was largely observed in axons as well as non-neuronal cells in proximal segments at day 4 after transection. In the distal segments, contrastingly, endoneurial fibroblasts or Schwann cells migrating into neuronal fibers showed positive staining with Wallerian degeneration. Although the precise functions of MIF in the peripheral nerves remain to be elucidated, the present results could represent a major departure from the current state of knowledge, revealing a novel function in the degenerative-regenerative process.

Animals

The effects of wrist distraction on carpal kinematics.

Changes in carpal kinematics under wrist distraction were studied in fresh cadaveric specimens. A magnetic tracking device measured kinematic motions of the scaphoid, lunate, and third metacarpal relative to the fixed radius in 3 planes of passive motion (coronal, sagittal, and "dart throwers") under progressive distraction loads. The change in percent contribution of the radiocarpal and midcarpal joints was calculated. Radiocarpal motion during extension was decreased as increasing traction was applied, but it increased with flexion. Motion of the scaphoid relative to the lunate was smaller in the oblique plane, resulting in less radiocarpal motion than in the sagittal plane. In the coronal plane, traction had little effect on radial deviation, but ulnar angulation of the scaphoid was greater with ulnar deviation of the wrist. These results suggest that different degrees of tension exist in the palmar and dorsal ligaments with the wrist under traction and during different planes of wrist motion. If wrist motion is desired during fixed traction, such as used clinically with external fixation, the dart-throwers motion (wrist extension with radial deviation and wrist flexion with ulnar deviation) appears to have the least impact on radiocarpal motion. If greater radiocarpal motion is desired, however, such as during postoperative mobilization, flexion-extension and radioulnar deviation will create more radiocarpal motion than the dart-thrower's motion.

Biomechanical Phenomena

Limited wrist fusions: comparison of results 22 and 89 months after surgery.

Limited wrist arthrodeses were performed to treat wrist diseases other than rheumatoid arthritis. The purpose of this study was to evaluate whether clinical and radiographic results noted 22 months after the procedure were maintained on re-examination an average of 89 months (range, 66-148 months) after the procedure. The study comprised 17 wrists. The average patient age was 42 years (range, 11-65 years). Two patients, both with Kienböck's disease, were lost to follow-up. Four radiocarpal and 11 intercarpal arthrodeses were performed. The range of motion between the first and second follow-up examination showed no significant difference. Grip strength likewise was nearly identical at both visits. At the last follow-up visit, progression of osteoarthrosis about the fusion area was noted in only 1 patient. These results suggest that the clinical and radiographic results at 22 months were maintained at the final follow-up visit and that the effect of limited wrist fusion does not deteriorate.

Adolescent

Late fracture of vascularized fibular grafts.

Subsequent fractures following the bone union were analyzed in 62 cases of vascularized fibular graft reconstruction. Fifteen cases (24%) of fractures, including four cases of two fractures, were observed. All fractures but one occurred within a year after obtaining bone union. Eighteen fractures occurred in the lower extremity. In the patients with tibial reconstructions, a significantly higher incidence of fractures was demonstrated in cases where there was a large bone defect and an inaccurate alignment of the graft. Proper graft alignment is an important factor in preventing stress fractures. Vascularized fibular grafts should be protected against excessive mechanical stresses during the first year following bony graft union.

Adult

Biomechanical analysis of limited intercarpal fusion for the treatment of Kienböck's disease: a three-dimensional theoretical study.

Although several types of intercarpal fusion have been advocated for the treatment of Kienbock's disease, the clinical outcome of each procedure is still inconclusive. The joint load and ligament tension based on a three-dimensional model were measured to determine which intercarpal fusion procedures unload the lunate and whether they alter the force transmission through the entire wrist joint. Ten theoretical models of wrists were used to simulate three different operative procedures: capitate-hamate fusion, scapho-trapezial-trapezoidal fusion, and scaphocapitate fusion. A discrete element analysis technique was used to perform these investigations. The joint force and ligament tension of normal wrists and of simulated operative procedures were calculated according to the deformation of each spring element, simulating the articular cartilage and the carpal ligaments. Scaphocapitate and scapho-trapezial-trapezoidal fusions significantly decreased the joint force at the radiolunate joint and the lunocapitate joint compared with the intact wrist. In contrast, these fusions significantly increased this value at the radioscaphoid joint in comparison with the intact wrist. In the midcarpal joint, scaphocapitate fusion also increased the joint force at the scapho-trapezial-trapezoidal joints and at the triquetral-hamate joint, whereas scapho-trapezial-trapezoidal fusion increased it at the scapho-capitate joint. Capitate-hamate fusion yielded no significant changes of the joint forces through the entire wrist joint. In the analysis of ligament tension, scaphocapitate and scapho-trapezial-trapezoidal fusions significantly decreased the tension only in the dorsal scapholunate ligament. These findings demonstrate that scaph-ocapitate and scapho-trapezial-trapezoidal fusions are effective in decompressing the lunate. By contrast, capitate-hamate fusion is ineffective in reducing lunate compression. Although scaphocapitate and scapho-trapezial-trapezoidal fusions are recommended for the treatment of Kienbock's disease, clinicians should consider that the increase of force transmission through the radioscaphoid and the midcarpal joints may lead to early degenerative changes after these procedures have been performed.

Arthrodesis

Clinical features and management of traumatic posterior interosseous nerve palsy.

The clinical features and results of treatment were reviewed in 17 traumatic palsies of the posterior interosseous nerve. Variations in clinical features depended on whether the recurrent branch or descending branch of the posterior interosseous nerve was injured. Seven patients had nerve repair, and two were treated by tendon transfers. Eight patients were treated conservatively. Sixteen of 17 patients recovered to more than M4 motor power at final follow-up. Associated muscle damage worsened the functional result.

Adolescent

Force transmission through the wrist joint in Kienböck's disease: a two-dimensional theoretical study.

This study quantifies the changes in force and pressure distributions across the wrist joint in different stages of Kienböck's disease using a 2-dimensional computer simulation model. Twenty-four cases classified as Lichtman's stage II, IIIA, or IIIB (8 cases in each category) were analyzed using the rigid body spring model technique. A 2-dimensional model in the posteroanterior plane of the wrist was loaded through the metacarpals under a total force of 142 N. The joint forces, peak pressures, and ligament tensions calculated on the involved side were normalized against the contralateral normal side values of the same patient. The results demonstrated that significant changes of the force transmission across the wrist joint occurred only from stage IIIA to IIIB, in which scaphoid rotation was prominent. On the basis of this study, scaphoid rotation plays an important role in affecting the wrist joint contact pressure distribution. This may be responsible for the progression of Kienböck's disease.

Biomechanical Phenomena

Functional results of low median and ulnar nerve repair with intraneural fascicular dissection and electrical fascicular orientation.

Twenty-eight low median nerve injuries and 23 low ulnar nerve injuries were repaired using intraneural fascicular dissection and electrical fascicular orientation. Eleven freshly lacerated nerves were seen within 48 hours after injury; 40 nerve lacerations were chronic. Fascicular orientation between sensory and motor fascicles at the proximal nerve end could be accurately differentiated in 47 nerves (92%) independent of whether it was acute or chronic. At the distal nerve end in fresh lacerations, the motor fascicles could be determined conclusively by muscle contraction with sequential electrical stimulation of the fascicles. In chronic nerve lacerations, the distal fascicles could be estimated anatomically after internal neurolysis. After fascicular orientation, nerves were repaired with end-to-end group fascicular suture or interfascicular sural nerve grafting. Twenty-four nerves repaired with end-to-end suture and 13 nerves repaired with nerve grafting were monitored more than 25 months. Satisfactory sensory results (i.e., S3+ or S4 functions) were obtained in 29 nerves (78%) and M4 or M5 motor functions were achieved in 29 nerves (78%). There were no patients who needed additional tendon transfers to reconstruct thumb opposition or to correct claw finger deformity. These results suggest that low median or ulnar nerve lacerations, whether acute or chronic, partial or complete, may be successfully repaired with the aid of electrical fascicular orientation with or without intraneural fascicular dissection.

Adolescent

Ulnar shortening for triangular fibrocartilage complex tears associated with ulnar positive variance.

Twenty-five patients with triangular fibrocartilage complex (TFCC) tears associated with ulnar positive variance who did not respond to conservative management were treated by ulnar shortening. The follow-up period averaged 35 months. All patients complained of pain, restricted forearm rotation, and weakness of grip. Arthroscopy was performed in 23 of 25 wrists to assess the status of the TFCC and the degree of the degenerative change of the proximal aspect of the lunate and triquetrum. Arthroscopic findings consisted of 15 class 1 and 8 class 2 tears according to Palmer's classification. When the TFCC showed a traumatic flap tear, only the torn flap was removed arthroscopically. Ulnar shortening averaged 3 mm. Transverse osteotomies healed in all patients at a mean postoperative time of 7 weeks. Twenty-three patients had either complete relief or occasional mild pain of the wrist. Two patients with persistent pain had additional procedures performed. Postoperative x-ray films revealed slight degenerative changes at the distal radioulnar joint in 7 patients. Complications included 1 reflex sympathetic dystrophy and 2 fractures through the osteotomy site after early plate removal. Ulnar shortening is a useful procedure for TFCC tears associated with ulnar positive variance.

Adolescent

Complete removal plus dorsalis pedis flap for arteriovenous malformation in the hypothenar region.

Complete removal of arteriovenous malformations of the hand, without functional impairment of the hand and fingers, is extremely difficult. A dorsalis pedis flap was used to reconstruct a soft-tissue defect, following complete removal of a malformation in the hypothenar region. This method allowed sufficient excision to militate against postoperative recurrence of the abnormality, while maintaining finger function. Two years after the operation, there has been no recurrence of the malformation and nearly normal finger function.

Adolescent

Endoscopic papillary dilation by balloon and isosorbide dinitrate drip infusion for removing bile duct stone.

BACKGROUND: Endoscopic papillary dilation (EPD) by balloon in the management of bile duct stones has recently been claimed to be effective for removing bile duct stones. METHODS: Without endoscopic sphincterotomy, we attempted to remove large or multiple bile duct stones through EPD combined with drip infusion of isosorbide dinitrate in 35 patients. Isosorbide dinitrate, at a rate of 5 mg/h, was administered intravenously, and a balloon dilator with a 10-mm diameter was inflated within 3 min across the papilla. Stones were then smashed using a mechanical lithotriptor, and the fragments were extracted with a basket or the balloon. RESULTS: Extraction of stones was successful in 33 (94%) of 35 patients by the combined therapy. Two of them (6%) developed mild pancreatitis. CONCLUSION: EPD combined with medical sphincter dilation was effective for large and multiple bile duct stones.

Adult

Second fracture of the distal humerus after varus malunion of a supracondylar fracture in children.

Nine children sustained a second fracture of the distal humerus after union of an ipsilateral supracondylar fracture which had healed with cubitus varus. There were eight boys and one girl with a mean age of five years (1 to 8) at the time of the second fracture which occurred at a mean of 1.5 years after the first. In all patients, the second fracture was an epiphyseal injury of the distal humerus, either associated with a fracture of the lateral metaphysis below the site of the previous supracondylar fracture, or a fracture-separation of the entire distal humeral epiphysis. This suggests that the physis and epiphysis tend to be more subject to injury than the metaphysis of the distal humerus in children who have had a previous supracondylar fracture with varus malunion.

Child

Treatment of flexor tendon sheath ganglions using ultrasound imaging.

Forty-one patients with a symptomatic digital mass or swelling of suspected ganglionic origin were examined by ultrasound. Findings were classified into 4 groups: group 1, solitary cyst appearing as a well-defined solitary oval anechoic mass (27 digits); group 2, multiple cysts having multiple oval anechoic masses (3 digits); group 3, solid tumor indicating a heterogeneous hypoechoic mass (6 digits); and group 4, tenosynovitis with no abnormal echoic mass (5 digits). Treatment was determined by lesion classification. In group 1, 26 of the 27 solitary cysts were punctured, and a jellylike material was aspirated from 24 cysts. Postaspiration ultrasound examination revealed that a cyst was still present in 2 cases, and these were excised surgically. In group 2, all the cysts were surgically removed. A ganglion with multiple cysts was confirmed on pathological examination. In group 3, the lesions were removed surgically; among the diagnoses were tendon sheath ganglion, giant-cell tumor of tendon sheath, neurilemmoma, and hemangioma. In group 4, no abnormal masses had appeared at follow-up examination. The 24 patients whose ganglions were treated by aspiration, as well as the 8 patients whose ganglions were excised, were monitored for more than 12 months. None of these 32 patients experienced residual pain or lesion recurrence. These results indicate that ultrasound is useful, in cases in which flexor tendon sheath ganglion are suspected, for assisting in diagnosis and determining whether patients should undergo aspiration or surgical excision.

Adolescent

Left brachial approach for transcatheter arterial embolization therapy in patients with hepatocellular carcinoma.

We evaluated the efficacy of the lipiodol-transcatheter arterial embolization (L-TAE) technique for hepatocellular carcinoma (HCC) performed using a left brachial approach. A total of 64 procedures were performed using the brachial route in 53 patients with HCC between 1989 and 1996 using a 4-French catheter and these patients were retrospectively studied. The technical success rate was 95.3%. The overall complication rate was 31.3%: fever of over 38.0 degrees C lasting longer than three days (18.8%), transient neurologic complications (4.7%), and pancreatitis (1.6%). Complications such as lumbago, back pain, and dissection of the celiac artery or its branches, which frequently complicated femoral approaches, were avoided. These data indicate that L-TAE using the left brachial approach may be a safe and effective alternative to the transfemoral approach in patients with HCC.

Adult

Free vascularised fibular strut graft for anterior spinal fusion.

A vascularised fibular strut graft was used for anterior spinal fusion in 16 patients with spinal kyphosis. The procedure was abandoned in three because of difficulty in establishing a vascular anastomosis and in one because the grafted fibula dislodged two days after operation. One patient died after five days. Of the 11 remaining patients, there were seven males and four females. Their ages at the time of operation averaged 30.9 years (12 to 71). The number of vertebrae fused averaged 6.7 (5 to 9) and the length of fibula grafted averaged 10.9 cm (6.5 to 18). Average follow-up was 54 months (27 to 84). Bone union occurred at both ends of the grafted fibula in all 11 patients, with an average time to union of 5.5 months (3 to 8). We did not see a fracture of the grafted fibula. Two patients had postoperative complications; the graft dislodged in one and laryngeal oedema occurred two days after operation in the other. A vascularised fibular strut graft provides a biomechanically stable and long-standing support in spinal fusion because the weak phase of creeping substitution does not take place in the graft.

Adolescent

Endoscopic lithotomy of common bile duct stones with sublingual nitroglycerin and guidewire.

OBJECTIVE: In 21 patients, our objective was the endoscopic removal of common bile duct stones by sphincter dilation with the application of sublingual nitroglycerin. METHODS: Nitroglycerin 0.3-0.6 mg was needed for proper dilation of the orifice and for successful cannulation of the Dormia basket into the bile duct. Cannulation of the Dormia basket was simplified by placing the guidewire in the common bile duct beforehand. Because of possible stone impaction, a mechanical lithotriptor was applied smoothly in two patients. RESULTS: Complete stone removal was successful in 18 of the 21 (86%) patients. One patient who developed a mild form of acute pancreatitis recovered in a few days by conservative management with drip infusion of protease inhibitor. Blood pressure dropped transiently in a patient receiving nitroglycerin, but the general condition of the patient was stable. CONCLUSIONS: This procedure was found to be safe, easy, and effective in extracting common bile duct stones.

Acute Disease