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Biomedical subjects

K Kaneda

Publications and source records attributed to K Kaneda.

At least 253 records · Page 14Linked to original sources
PubMed1994

Administration of recombinant human interleukin-7 to mice induces the exportation of myeloid progenitor cells from the bone marrow to peripheral sites.

The administration of recombinant human interleukin-7 (rhIL-7) to mice twice a day for 7 days does not appreciably change bone marrow (BM) cellularity, but does result in a threefold to fivefold increase in the total number of leukocytes in the spleen, an eightfold to 10-fold increase in the total number of nonparenchymal cells (NPC) obtained from the liver, and up to a 20-fold increase in the total number of peripheral white blood cells (WBC). This regimen of rhIL-7 administration also causes a profound reduction in the total number of progenitors in the BM for both single-lineage colony-forming units-culture (CFU-c) (> 90%) and multilineage CFU-granulocyte, erythroid, monocyte, megakaryocyte (CFU-GEMM) (> 99%) colonies. In contrast, mice treated with rhIL-7 exhibited increases in both CFU-c (20- to 40-fold, 20-fold, and 15- to 40-fold) and CFU-GEMM (8- to 10-fold, 30-fold, and 6- to 10-fold) cultured from the peripheral blood, spleen, and NPC, respectively. The increase in CFU in the NPC was accompanied by a fivefold increase in the number of MAC-1+ cells and a ninefold increase in the number of 8C5bright+ cells. Splenectomy of mice before the administration of rhIL-7 further increased the total number of WBC, NPC, and myeloid progenitors as compared with the rhIL-7-treated nonsplenectomized mice. Finally, selective depletion of the BM by intraperitoneal administration of 89Sr (98% reduction in BM cellularity and > 99% reduction in BM myeloid progenitors) abrogated the rhIL-7-induced increases in cellularity and myeloid progenitor number in the peripheral blood, spleen, and NPC. These results show that the changes in myelopoiesis observed after in vivo administration of rhIL-7 to mice result largely from the emigration of myeloid progenitors from the BM through the blood to the spleen, liver, and, possibly, other peripheral organs.

Animals↗
PubMed1994

Quantitative analysis of rod-cored vesicles and dense granules of large granular lymphocytes in the liver, spleen, and peripheral blood of rats.

Large granular lymphocytes (LGL) comprise a natural defense system in the liver and exert an inhibitory effect on tumor cell metastasis. In order to demonstrate the maturation of LGL in the liver from the morphological aspect, we evaluated electron-microscopically the frequency of 0.2 micron vesicles (rod-cored and "empty" vesicles) and dense granules in LGL from the liver, spleen, and peripheral blood of the rat. Both of these cell organelles are characteristic to LGL and may relate to natural killer-mediated cytolysis. On the average, there were 12.7 of the 0.2 micron vesicles and 4.3 rod-cored vesicles (RCV) per cell section in the liver, 6.6 0.2 micron vesicles and 1.6 RCV in the spleen, and 8.6 0.2 micron vesicles and 0.9 RCV in the peripheral blood. The number of 0.2 micron vesicles per cell section ranged from 0 to 19 with the exception of a few higher instances. Therefore, LGL were divided into vesicle-rich (> 9 0.2 micron vesicles per cell section) and vesicle-poor (< 8 per cell section) populations. Hepatic LGL consisted mainly of a vesicle-rich population while splenic LGL consisted mainly of a vesicle-poor population, and peripheral blood contained equal proportions of both populations. In addition to diversity with regard to the number of 0.2 micron vesicles, LGL obtained from various organs also displayed heterogeneity in the number and size of dense granules.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Low content of estrogen receptors in human giant cell tumors of bone.

We tried to identify estrogen receptors (ERs) in human giant cell tumors of bone. Samples from eight patients were used for biochemical and immunohistochemical studies using [125I]17 beta-estradiol and monoclonal antibody against the human ER. Estradiol binding sites were detected in seven cases out of eight. The dissociation constant of the higher affinity binding site was 0.5 nM. Nonlabeled 17 beta-estradiol and synthetic estrogen, diethyl-stilbestrol, inhibited the binding of labeled 17 beta-estradiol to the tumor cytosol, while dexamethasone did not inhibit the binding. Using a monoclonal antibody. Western blotting identified bands of M(r) 68,000 and 59,000. No ERs were observed in any case examined immunohistochemically. These results suggest that human giant cell tumors of bone have a low level of ERs that cannot be detected immunohistochemically.

Adolescent↗
PubMed1994

Reconstruction of an iliac crest defect with a bioactive ceramic prosthesis.

Between June 1987 and December 1990, an iliac crest prosthesis made of bioactive apatite- and wollastonite-containing glass ceramic (A-W.GC) was used in 60 patients for the reconstruction of the iliac crest defect after harvesting autogenous tricortical iliac bone graft. The clinical results of this prosthesis were satisfactory. No patients felt spontaneous pain in the reconstructed area, and 93% of the patients had no tenderness there. In the radiological evaluation at the final follow-up, no apparent "radiolucent clear zone" was detected at the prosthesis-iliac bone junction in 98% of the patients. Excellent new bone formation between the prosthesis and the iliac crest was also noticed in 96% of the patients. The A-W.GC iliac crest prosthesis was beneficial for reconstruction of the iliac crest defect.

Adolescent↗
PubMed1994

Extensive subcutaneous calcification of the forearm in systemic lupus erythematosus.

We report two cases with long-standing systemic lupus erythematosus (SLE) who developed widespread calcification in subcutaneous tissue and peri-articular structures. To our knowledge only 26 case reports have appeared concerning this abnormality in SLE. However, there has been no report of calcification in an SLE patient in the literature of orthopaedic surgery. The calcifications of the forearm were marginally removed because of pain surrounding them. X-ray analysis revealed that the calcification was made of pure calcium phosphate.

Adult↗
PubMed1994

Monitoring the evolution of intramedullary lesions in cervical spinal cord injury. Qualitative and quantitative analysis with sequential MR imaging.

The evolution of intramedullary lesions following an acute spinal cord injury was monitored with sequential magnetic resonance (MR) imaging. Seven patients who had sustained cervical spinal cord injuries were followed up from the acute to the chronic phase of the cord injury. MR images were evaluated not only qualitatively but also quantitatively. All intramedullary lesions were quantitatively analysed by T2 values. In the qualitative analysis, the regions with hyperintensity on T2-weighted images and isointensity on T1-weighted images were consistent with the region of simple oedema or gliosis. The former gradually disappeared after the acute phase, whereas the latter remained until the chronic phase. The regions with hyperintensity on T2-weighted images and hypointensity on T1-weighted images may represent cysts filled with necrotic tissue or clear fluid, or necrosis. The evolution of these lesions was also able to be monitored quantitatively by T2 values.

Adult↗
PubMed1994

Post-tetanic count and single twitch height at the onset of reflex movement after administration of vecuronium under different types of anaesthesia.

We have studied post-tetanic count (PTC) and single twitch height at the onset of reflex movement to carinal stimulation after administration of vecuronium with five different types of anaesthesia. Seventy-five adult patients were allocated randomly to five groups of 15 patients each, to receive one of the following anaesthetics: neuroleptanaesthesia (fentanyl and droperidol) or 1 MAC of either halothane, isoflurane, enflurane or sevoflurane with 66% nitrous oxide in oxygen. During spontaneous recovery from vecuronium-induced neuromuscular block, the carina was stimulated with a suction catheter every 150 s. Single twitch heights at the onset of reflex movement were similar (2.0-2.7% of control values) between the five groups. In contrast, PTC at the onset of reflex movement to carinal stimulation differed (7.4-17.0) between groups.

Adult↗
PubMed1994

Transpedicular screw fixation for traumatic lesions of the middle and lower cervical spine: description of the techniques and preliminary report.

Thirteen patients with fractures and/or dislocations of the middle and lower cervical spine were treated by transpedicular screw fixation using the Steffee variable screw placement system. Postoperative immobilization was either not used or simplified to short-term use of a soft neck collar. Recovery of nerve function and correction of kyphotic and/or translational deformities were satisfactory. All patients had solid fusion without loss of correction at the latest follow-up. There were no neurovascular complications. It was concluded that transpedicular screw fixation is as strong a fixation procedure for the cervical spine as it is for the thoracic and lumbar spine. This surgical procedure is associated with some risks of major neurovascular injuries; however, safety is adequate if the procedure is performed by experienced surgeons using meticulous surgical techniques.

Adolescent↗
PubMed1994

Significance of Gd-DTPA-enhanced magnetic resonance imaging for lumbar disc herniation: the relationship between nerve root enhancement and clinical manifestations.

Gd-DTPA-enhanced magnetic resonance (MR) imaging can depict not only the morphology but also the pathological changes of a nerve root compressed by herniated disc. Enhanced MR imaging was performed on 115 patients treated surgically for lumbar disc herniation. Nerve root enhancement was seen in 39.1% of the patients preoperatively and in 58.7% postoperatively. Preoperative root enhancement reflects the radicular pain intensity rather than the degree of neurological deficits, whereas postoperative enhancement did not correlate with the radicular symptoms. Nerve root enhancement represents an intraneural edema in the affected nerve root. Enhanced MR imaging is a potential method for the identification of an affected nerve root in patients with a discrepancy between the level of disc herniation and neurological manifestations.

Adolescent↗
PubMed1994

Light and electron microscopic analysis of liver sinusoids during hepatocarcinogenesis with 2-acetylaminofluorene in rats.

To clarify the sequential changes and morphological differences of the sinusoidal structures between hepatocellular carcinoma (HCC) and hepatocellular adenoma (HA), we examined morphological changes of sinusoidal cells and related structures such as basement membrane during hepatocarcinogenesis in the rat. During continuous feeding of carcinogenic diets containing 2-acetylaminofluorene to rats, HA appeared at the 8th week in the peripheral area and then extended toward the centrolobular area. The appearance of HCC was recognized at the 27th week. In the HA lesion, the morphology of sinusoidal cells and related structures was basically the same as that of normal liver except for a slight thickening of the basement membrane and a decreased amount of vitamin A-lipid droplets of stellate cells. In HCC, the fenestrations of endothelial cells disappeared and the basement membrane became continuous, thick and often multilayered. Stellate cells contained almost no vitamin A-lipid droplets and were associated with abundant collagen fibers. Kupffer cells and pit cells were not seen inside the sinusoid. All these features of the sinusoids in HCC resembled the morphological characteristics of the capillary. The present study has revealed that HCC possesses sinusoid structures distinct from those of HA. This suggests that HCC may not derive directly from HA but may develop newly within the HA.

2-Acetylaminofluorene↗
PubMed1994

[Involutional osteoporosis].

Involutional osteoporosis has been divided into two types. Type-1 osteoporosis, known as postmenopausal osteoporosis, occurs in women after menopause. Type-2 osteoporosis, known as senile osteoporosis, occurs in men and women over 70 years of age. The general symptoms are back pain in patients with Type-1 osteoporosis and back pain with spinal deformity in Type-2. Vertebral fractures occur in Type-1 and fractures of the femoral neck are common in Type-2. Post-traumatic vertebral collapse following compression fractures is recently recognized as one of the important and serious complications in osteoporotic fractures. Other fractures such as femoral neck, wrist (distal radius) and proximal humerus are common in this disease. Study of bone metabolism and its pharmaceutical reaction has advanced, but the treatment of osteoporosis is still not satisfactory.

Aged↗
PubMed1994

The effects of independent living on persons with chronic mental illness: an assessment of the Section 8 certificate program.

The feasibility of the Section 8 certificate program for individuals with chronic mental illness (CMI) and the outcomes associated with independent housing are examined. The analysis is based on data from a longitudinal survey of Section 8 certificate users in Baltimore and Hamilton County (Cincinnati) and on information from Section 8 application forms in each site. A pre-post research design was used to examine changes in hospitalization, residential stability, and mental health service outcomes. Four key dimensions of the CMI certificate program are examined: affordability, housing conditions, neighborhood conditions, and service gaps. Results suggest that the certificate program has a positive effect on independent living, that certificate use is associated with positive mental health outcomes, and that there is no evidence of "creaming" among program applicants.

Activities of Daily Living↗
PubMed1993

Effects of complete stress-shielding on the mechanical properties and histology of in situ frozen patellar tendon.

The effects of freezing and stress-shielding on the mechanical properties and histology of the patellar tendon (PT) were studied with the use of 28 mature Japanese white rabbits. The PT was frozen in situ by liquid nitrogen to kill the fibroblasts and then, for stress-shielding, a stainless-steel wire, installed between the patella and the tibial tubercle, was stretched to release all tension in the PT. After being allowed unrestricted activity in their cages for 1, 2, 3, or 6 weeks, the animals were killed, and the PTs were excised for mechanical and histological study. The cross-sectional area of the frozen and stress-shielded PT started to increase significantly 1 week after the treatment and leveled off at 3 weeks. In contrast, the tensile strength and elastic modulus began to decrease significantly at 1 week, falling to 15% of the control values at 6 weeks. Histologically, cells were absent until 2 weeks after freezing and stress-shielding, although new cells appeared by 3 weeks. Splitting and fragmentation of collagen bundles were observed beginning at 2 weeks. These results indicate that complete stress-shielding led to substantial changes in the mechanical properties of the once-frozen PT, even in the absence of the tissue remodeling process by fibroblasts.

Animals↗
PubMed1993

Repair and/or reconstruction of scapholunate interosseous ligament in lunate and perilunate dislocations.

This study was undertaken to ascertain whether repair and/or reconstruction of the scapholunate interosseous ligament can prevent or reduce the occurrence of carpal instability and improve the clinical results. Thirty-two patients with lunate and perilunate dislocations were treated in the last 12 years. Of the 32, only 2 patients were seen within 4 weeks of injury, and the remaining 30 patients were seen and treated more than 4 weeks after the dislocation. Patients were followed for an average of 5 years. The scapholunate interosseous ligament was repaired and reconstructed in 12 patients (group 1). In 20 patients the ligament was not repaired or reconstructed (group 2). Clinical results were expressed by a modification of the point score method of Green and O'Brien. The scapholunate angles were measured on the lateral x-ray films with the wrist in neutral position. In group 1 clinical results averaged 82 points, while in group 2 they averaged 59 points. The scapholunate angles in group 1 averaged 50 degrees whereas in group 2 they averaged 69 degrees. These clinical and x-ray film results suggest that scapholunate interosseous ligament repair and/or reconstruction can prevent or reduce the occurrence of carpal instability and improve clinical results.

Adolescent↗
PubMed1993

Correlation between histopathologic features and magnetic resonance images of spinal cord lesions.

The authors report a correlation between histopathologic features and magnetic resonance images of spinal cord lesions in 19 human spinal cords with various types of lesions. Abnormally high T2-weighted image signal intensities appeared nonspecifically in mildly altered lesions or areas with edema. In the gray matter, a low T1-weighted image in addition to a high T2-weighted image signal intensity appeared in severely altered lesions with necrosis, myelomalacia, or spongiform change. In the white matter, abnormally high T1-weighted image intensities appeared in severely altered lesions. Based on these preliminary results, it appears that a correlation between the degree of histopathologic alteration of the spinal cord and magnetic resonance images in clinical cases can be made. This is the first study to clarify the correlation between histopathologic features and magnetic resonance images of the diseased human spinal cord.

Aged↗
PubMed1993

A biomechanical definition of spinal segmental instability taking personal and disc level differences into account.

The biomechanical definition of spinal segmental instability has not been clarified sufficiently, because of the great personal and level differences in intervertebral disc deformation. This article proposes a new method of judging spinal segmental instability regardless of these differences, using lateral functional radiographs. The linear relationship between the disc geometry and the disc deformation was confirmed in the normal intervertebral discs. The degree of spinal segmental instability could be evaluated statistically by calculating a regression residual from the regression line of the normal discs. Strain distributions of an intervertebral disc in the sagittal plane also were investigated to make sure of the differences in the deformation behaviors between normal spines and unstable lumbar spines. Although normal lumbar spines showed the consistent deformation pattern, the patterns of the unstable lumbar spines were different.

Adult↗
PubMed1993

Effects of stress shielding on the mechanical properties of rabbit patellar tendon.

Mechanical properties of the stress-shielded patellar tendon were studied in the rabbit knee. Stress shielding was accomplished by stretching a stainless-steel wire installed between the patella and tibial tubercle and thus, releasing the tension in the patellar tendon completely. Tensile tests were carried out on the specimens obtained from the patellar tendons which were exposed to the stress shielding for 1 to 6 weeks. The stress shielding changed the mechanical properties of the patellar tendon significantly: it decreased the tangent modulus and tensile strength to 9 percent of the control values after 3 weeks. There was a 131 percent increase in the cross-sectional area and a 15 percent decrease in the tendinous length. Remarkable changes were also observed in the structural properties: for example, the maximum load of the bone-tendon complex decreased to 20 percent of the control value after 3 weeks. Histological studies showed that the stress shielding increased the number of fibroblasts and decreased the longitudinally aligned collagen bundles. These results imply that if no stress is applied to the autograft in the case of augmentative reconstruction of the knee ligament, the graft strength decreases remarkably.

Animals↗