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Biomedical subjects

K Kaneda

Publications and source records attributed to K Kaneda.

At least 289 records · Page 16Linked to original sources
PubMed1992

The microvasculature of the human bone marrow correlated with the distribution of hematopoietic cells. A computer-assisted three-dimensional reconstruction study.

Surgical specimens of ordinary bone marrow from eight patients were submitted to computer-assisted three-dimensional reconstruction from resin-embedded, semi-thin serial sections. This was undertaken with the aim of contributing to a better understanding of hematopoietic microenvironment by establishing the basic architecture of the bone marrow, particularly the microvasculature and its relation to the hematopoietic cell series. The basic vascular structure was found to consist of mutually intertwining sinuses and hematopoietic cords (or compartments), the latter with an arteriole running along the axis. This allowed to define the unitary structure of the bone marrow as a hematopoietic cord with a central arteriole and surrounded by sinuses. Here granulopoietic cells were distributed mostly along the wall of the central arteriole. Erythropoietic cells, located mainly around the sinus wall, proved to be forming a continuous network of cord instead of separate "islands" as usually assumed, justifying a designation of "erythroblastic cords". Megakaryocytes were positioned in close vicinity to the sinus wall. These findings appear not only to be helpful in analyzing factors involved in the in vivo hematopoiesis of man, but also to visualize the importance of structural studies of bone marrow.

Adult↗
PubMed1992

A ten- to 15-year follow-up observation of high tibial osteotomy in medial compartment osteoarthrosis.

High tibial osteotomy (HTO) was performed on 86 medially osteoarthritic knees in 78 patients. Twelve patients died during the follow-up period. Fifty-six knees of 51 patients were evaluated twice postoperatively: once at six years after surgery and again after ten to 15 years. Results were satisfactory in 88% of the knees at the six-year follow-up evaluation and in 63% at the post-ten-year follow-up evaluation. Ten-year follow-up results significantly deteriorated. The femorotibial angle (FTA) at the time of bone union after HTO was a significant factor that contributed to the ten-year results. In patients maintaining excellent improvement of knee function at the post-ten-year follow-up evaluation, the mean FTA at one year after surgery was 165 degrees; this value was constant through ten years after HTO. An FTA of 164 degrees-168 degrees should be attained to ensure favorable long-term results in HTO.

Bone Nails↗
PubMed1992

Modified Chiari pelvic osteotomy: a long-term follow-up study.

In a series of 100 modified Chiari pelvic osteotomies in ninety-six patients, who were followed for an average of nine years and three months (range, six years to fourteen years and eight months), an excellent or good clinical result was obtained in seventy-eight hips. The level of the osteotomy line on postoperative radiographs was compared with the clinical result. The average clinical result was good in seventy-four (84 per cent) of the eighty-eight patients in whom the osteotomy was at the I-I, I-II, or II-II level, according to the classification of levels by Azuma et al., but was good in only four of the twelve patients in whom the osteotomy was at another level (p = 0.0003). We found that smooth anterior and lateral coverage can be obtained by the use of a dome-shaped osteotomy line.

Adolescent↗
PubMed1992

[Intra-atrial implantation of mitral valve prosthesis in 2 patients with active infective endocarditis complicated by mitral annular destruction].

This is a report of two patients with extensive destruction of the mitral annulus due to active infective endocarditis. Patient 1 was a 66-year-old female and the patient 2 was a 59-year-old male. In both patients medical therapy had failed to control endocarditis and emergency mitral valve replacements were carried out. At the operation special surgical techniques were necessitated, since insertion of artificial valves in the annulus was impossible because of the lack of the annular tissue due to destruction and excision. On the posterior commissure side, mitral valve prosthesis were sutured to the left atrial wall just above the anatomical mitral ring. Furthermore, in patient 2, a bovine pericardium collar attached to the prosthetic valve was sutured to the left atrial wall to secure fixation of the prosthetic valve. The postoperative courses were uneventful in both patients. This technique seems to be useful in patients with mitral annular destruction.

Aged↗
PubMed1992

[Chromosome and DNA analyses of peripheral blood lymphocyte from the quadruple cancer patient].

The patient with quadruple cancer was a 32 year-old female who had osteosarcoma, bilateral breast cancer and adenocarcinoma of the lung. When chromosomal analysis of peripheral blood lymphocyte was performed, two abnormal cells were detected among 42 cells examined. The first cell showed a translocation involving chromosome 1 and 20 and trisomic for chromosome 19. The second cell was trisomic for chromosome x. Southern blot analysis of DNA from peripheral blood lymphocyte revealed that there was no difference in the expression of Rb gene between the patient and healthy adult.

Adenocarcinoma, Papillary↗
PubMed1992

The value of hepatic artery reconstruction as a technique in rat liver transplantation.

The importance of hepatic artery reconstruction in the success of liver transplantation in the rat has been studied. Rat liver grafts were performed with or without reanastomosis of the hepatic artery, both in rejector and nonrejector donor/recipient combinations. No significant improvement in recipient survival was found when arterialization was performed, and histologic studies showed no differences in hepatocyte or bile duct architecture between arterialized and nonarterialized groups. Thus, arterialization does not make an important contribution to the outcome of liver transplantation in the rat; biliary complications associated with the nonarterialized method appear to be technique-related rather than the result of ischemia.

Anastomosis, Surgical↗
PubMed1991

Treatment of osteoarthritis of the knee with heel wedges.

Sixty-two patients with early medial compartment osteoarthritis of the knee were treated with lateral heel wedges and followed for from 7 years and 5 months to 12 years. Those who were treated with heel wedges and analgesics showed a significantly greater improvement in pain score than those treated with analgesics only, but not in the walking ability score at the second follow up. The lateral heel wedge had no effect on the progress of the radiographic changes. The lateral heel wedge is useful for patients with early medical compartment osteoarthritis provided it is used with an understanding of the indications and its limitations.

Adult↗
PubMed1991

Localization and ultrastructure of the Kupffer cells in orthotopically transplanted liver grafts in the rat.

Kupffer cells play an important role in the acceptance or rejection of liver grafts. We examined the ultrastructure of the Kupffer cells in transplanted rat livers, from an early to a late stage where the graft is accepted, using a DA-to-PVG combination. Two days after surgery, endocytic activity of the Kupffer cells had increased, as evidenced by worm-like structures and many endocytic vacuoles. There was often close apposition to the monocytes or lymphocytes. By day 4, infiltration of mononuclear cells into the sinusoids was readily noticeable. By day 7, several Kupffer cells had migrated into the space of Disse through the openings in endothelial linings. The number of Kupffer cells reached a maximum at 14 days. They were located mostly outside the sinusoid, adhering to the hepatocytes. At this point in time, however, the Kupffer cells contained few endocytic vacuoles and phagolysosomes, in contrast to those at 2 days. The number and location of Kupffer cells became almost normal at 2 months. The present results indicate that Kupffer cells are highly activated before mononuclear cell infiltration becomes manifest in the sinusoid, and that when a rejecting reaction reaches a peak, they are usually located extrasinusoidally and show a morphologically immature profile.

Animals↗
PubMed1991

The practical use and evaluation of picture archiving and communication system in the Department of Orthopaedic Surgery.

A picture archiving and communication system (PACS) was started in June 1989 in the outpatient clinic of the Department of Orthopaedic Surgery, Hokkaido University, Sapporo, Japan. The PACS system has several advantages: space savings for storage of images, safe custody and quick access to image data, simultaneous access to image data, the possibility of obtaining good quality data on utilization of images, and applications for medical education and resident training. However, this system has just begun, and several problems must still be solved. In this article, we describe our experiences with the PACS system in the outpatient clinic of the department of orthopaedic surgery.

Hospital Departments↗
PubMed1991

Hemiresection-interposition arthroplasty of the distal radioulnar joint associated with repair of triangular fibrocartilage complex lesions.

Sixteen wrists of 15 patients with traumatic triangular fibrocartilage complex tears were treated by hemiresection-interposition arthroplasty of the distal radioulnar joint combined with repair of the torn triangular fibrocartilage complex. The surgical procedure was performed to avoid impingement of the ulnar head against the reconstructed triangular fibrocartilage complex. Most of the wrists showed a positive ulnar variance. The average age of the patients was 39 years. Follow-up averaged 41 months. Complete relief of pain was obtained in 10 wrists. Slight pain persisted in 6 wrists, although it was less than before surgery. The range of motion of the wrist joint and forearm improved postoperatively. Grip strength in all wrists increased. Postoperative complications occurred in 7 wrists of 6 patients: reoperation in 2 wrists, fracture in 1, and tendinitis of the extensor carpi ulnaris in 4. All 15 patients subsequently returned to their previous occupations.

Adult↗
PubMed1991

A biomechanical analysis of Zielke, Kaneda, and Cotrel-Dubousset instrumentations in thoracolumbar scoliosis. A calf spine model.

A biomechanical study was performed in order to evaluate the initial stability of three spinal instrumentation systems, applied to a scoliosis model. Five calf spines (T11-L2) were destabilized anteriorly, and, by inserting a wedge-shaped resin disc within each destabilized intervertebral space, a thoracolumbar scoliosis was created. Three spinal instrumentation systems (Zielke anterior instrumentation, Kaneda anterior multisegmental fixation device, and Cotrel-Dubousset posterior instrumentation) were applied to correct the simulated scoliotic condition. Mechanical nondestructive cyclical testing in axial compression, rotation, flexion, and extension was performed on each spinal construct. The Kaneda device was the most stable instrumentation in all four loading conditions. Zielke instrumentation failed to restore the stability to the level of the intact spine in rotation, and was the least rigid instrumentation in flexion and extension. The Cotrel-Dubousset instrumentation demonstrated favorable stability in flexion and extension, but became the least rigid instrumentation in axial compression and rotation. This study suggests that a one-stage procedure with Zielke instrumentation and a two-stage procedure (anterior release with bone graft and posterior stabilization) with Cotrel-Dubousset instrumentation applied for the correction of scoliosis, should be supplemented with additional external or internal supports. The Kaneda device may offer enough stability with an anterior procedure alone in the correction of scoliosis.

Animals↗
PubMed1991

Protection of mice from lethal endotoxemia by use of an ornithine-containing lipid or a serine-containing lipid.

The effects of an ornithine-containing lipid [alpha-N-(3-acyloxyacyl)-ornithine (Orn-L)] or a serine-containing lipid [alpha-N-(3-acyloxyacyl)-serine (Ser-L)] from Flavobacterium meningosepticum on lethal endotoxemia in mice were examined. When 500 micrograms of Orn-L was intravenously administered 1 h before intravenous administration of a lethal dose of endotoxin, none of the mice died. The protective effect of Ser-L was weaker than that of Orn-L. Light and electron microscopic studies demonstrated that necrosis of hepatocytes caused by endotoxin was prevented by pretreatment with Orn-L. Furthermore, Kupffer cells were activated morphologically 1 h after the administration of Orn-L or Ser-L, and the liposomes of the lipoamino acids were incorporated into phagolysosomes in activated Kupffer cells. The activity of tumor necrosis factor in sera of endotoxin-treated mice was decreased markedly by pretreatment of mice with Orn-L. In vitro, the lipoamino acids suppressed endotoxin-induced tumor necrosis factor generation but did not suppress tumor necrosis factor generation induced by zymosan and whole cells of Staphylococcus aureus. These results suggested that Orn-L and Ser-L can be used as specific blocking agents against endotoxin. The blocking mechanism may be antagonistic, because of the structural similarities between the lipoamino acids and endotoxin lipid A.

Animals↗
PubMed1991

Ultrastructural characteristics of lymphokine-activated killer cells of the rat in comparison with natural killer cells.

Lymphokine-activated killer (LAK) cells with a broad spectrum of tumor cell killing have been reported to be related to natural killer (NK) cells morphologically and phenotypically. We here examine the ultrastructural characteristics of LAK cells of the rat, comparing them to those of normal and OK-432-activated NK cells. Results show that, five days after the culturing of spleen lymphocytes with human recombinant interleukin-2, there were induced LAK cells, which were large granular lymphocytes and had a cytotoxic capacity against NK-resistant P-815 tumor cells. They were larger in size than NK cells and richer in cell organelles such as ribosomes, rough endoplasmic reticulum, a Golgi apparatus, granules and vesicles. The granules of LAK cells were shown to be related to multivesicular bodies as those of NK cells; they included multivesicular bodies, fully dense granules and intermediate forms between them. The average numbers and sizes of the granules and the proportion of multivesicular bodies and intermediate forms among the total granules were greater in LAK cells than in NK cells. The density of the small vesicles packed in multivesicular bodies and intermediate forms was much higher in LAK cells. At the contacting surface of the LAK cells bound to the target cells, exocytosis of multivesicular bodies was shown to occur. We recognized here two populations of LAK cells with different types of vesicles, one containing rod-cored vesicles and the other a new type of vesicles termed "demilune-cored vesicles". The latter vesicles were the same in size as the rod-cored ones and contained a dense core located eccentrically. Between these two populations of LAK cells, there was no difference concerning the profile of the dense granules. The present study indicates that, although LAK and NK cells share several ultrastructural features, the former show markedly enriched cell organelles, which indicate an accelerated metabolism of the cell for continuous proliferation.

Animals↗
PubMed1991

The intracellular distribution of cell organelles in natural killer cells during the cytolysis of bound tumor cells, with special reference to the rod-cored vesicles.

The secretory function of the natural killer (NK) cells has been considered to be essential for cytolytic activity against their target cells. In this study, the distribution and spatial relationship of various cell organelles which participate in the secretory process, i.e., Golgi apparatus, vesicles, granules and microtubules, were examined ultrastructurally in non-treated and OK-432-activated rat NK cells bound to the tumor cells, with special reference to the rod-cored vesicles which are the most characteristic structure of the NK cells. Rod-cored vesicles and their closely related structures, "empty" vesicles, were derived from the end portion of the Golgi trans cisternae and became accumulated in the central area which was surrounded by the Golgi apparatus, nucleus and contact surface. Some of the vesicles appeared to be further transported to the contact area along the microtubules extending from the centrioles toward the bound targets. The access of the vesicles to the contact surface occurred at that portion where subplasmalemmal actin lattice was thin. The distribution of the dense granules and multivesicular bodies was similar to that of the vesicles, but the area of their occurrence was a little wider. At the outer aspect of the Golgi apparatus was situated the endoplasmic reticulum from which transitional vesicles came to the inner or cis cisternae of the apparatus. The present observations indicate that the cell organelles of the conjugated NK cells are purposefully arranged in the cytoplasm in such order that the generated rod-cored vesicles and "empty" ones are efficiently directed toward the bound tumor cells.

Animals↗
PubMed1991

Muscle weakness after anterior cruciate ligament reconstruction using patellar and quadriceps tendons.

Eighty-five knees of 85 patients who underwent anterior cruciate ligament reconstruction with autologous patellar and quadriceps tendon grafts were followed for 3-7 years. Hamstrings strength improved to normal. Quadriceps strength in men returned to the preoperative level, but not to normal strength. Quadriceps strength in women, at the final follow-up, was significantly less than it had been preoperatively. This weakness may be a consequence of impairment of the knee extensor mechanism resulting from harvesting the graft. Although favorable postoperative stability of the knee was obtained, we do not recommend this technique for ACL reconstruction because of the quadriceps weakness.

Adolescent↗
PubMed1991

Long-term evaluation of high tibial osteotomy for medial osteoarthritis of the knee.

Fifty-five medial osteoarthritic knees in 50 patients who had undergone high tibial osteotomies (HTO) were followed up twice: once, six years after surgery, and again, 10-15 years postoperatively. The results were satisfactory in 85% of the knees at the six-year follow-up and in 62% of the knees at the 10-year follow-up. The results post 10 or more years had deteriorated significantly compared to those seen six years postoperatively. In patients maintaining excellent improvement of knee function post 10 or more years, the mean femorotibial angle (FTA) one year after surgery had been 165 degrees; this value remained constant for 10 years postoperatively. The authors believe that an FTA of 164 degrees - 168 degrees should be set as a goal when performing a high tibial osteotomy to ensure favorable long-term results in HTO.

Aged↗
PubMed1991

[Blind ending bifid ureter with stone in the blind branch: report of a case].

Blind ending bifid ureter is a rare anomaly in the urinary tract. This anomaly may result from failure of a premature branch of the ureteral bud to join with the metanephric blastema. A 21-year-old man was admitted with macroscopic hematuria and colic pain in the left flank region. Urinalysis demonstrated hematopyuria and excretory urography suggested bifid ending accessory ureter with a stone on the left side. Surgical exploration showed that the accessory ureter was bifurcated from the left ureter at about 5 mm from the bladder wall and ran parallel with the left ureter. Although dense adhesions to the surrounding tissue existed, the accessory ureter was resected at the site of the junction. It measured 3 cm in length and 1 cm in greatest diameter. The stone found at the tip of the accessory ureter was composed of calcium oxalate (24%) and calcium phosphate (76%). Histological examination revealed that the ureter had all layers of normal ureteral structure and no renal tissue was identified in the specimen resected. During a follow-up period of 22 months after the operation, he was free of urinary tract infection and abdominal pain. Of 77 cases with blind ending bifid ureter reported in the Japanese literature, a ureteral stone was found in the blind branch in only 5 cases.

Adult↗