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Biomedical subjects

N H Kim

Publications and source records attributed to N H Kim.

At least 19 recordsLinked to original sources
PubMed1992

On detecting the presence of fetal R-wave using the moving averaged magnitude difference algorithm.

An efficient algorithm detecting the presence of a fetal QRS complex is presented. The proposed fetal QRS detection method computes the averaged magnitude of the difference between the fetal ECG signal and the reference signal to detect the fetal QRS event. The detected fetal QRS complexes are exponentially averaged to generate the template signal which can track the slowly varying shape of the fetal ECG signal. As an effort to obtain improved detection performances, two approaches of normalizing the fetal ECG signal and the template are considered.

Algorithms↗
PubMed1992

Effect of porcine bone morphogenetic protein on healing of bone defect in the rabbit radius.

Segmental long bone defects due to infection or trauma is a difficult problem to manage in patients. We studied the effect of porcine bone morphogenetic protein (pBMP) on healing of defects in the rabbit radius. Porcine BMP was separated and purified from the tibia and femur of pigs by repeated solubilization and precipitation of the protein with different concentrations of urea and GuHCl. The osteoinductive activity of pBMP was confirmed by bioassay using No. 615 mice. In rabbits, about a 15 mm length of radii were removed and 20 mg of pBMP was implanted in the defected area with fibrin sealant (FS), while only FS was implanted in controls. Union of the affected area was observed in 6 weeks in the experimental side. There was no definite evidence of bone bridging across the affected area in the controls. This suggests that pBMP has a bone forming activity in other species and the clinical use of pBMP in treating patients with segmental bone defects is promising.

Animals↗
PubMed1991

An experimental intraarticular implantation of woven carbon fiber pad into osteochondral defect of the femoral condyle in rabbit.

The defects of the articular cartilage structure are not replaced unless the subchondral plate has been breached. However, following the creation of a defect in the subchondral plate, the area is filled in with a fibrous tissue which gradually transforms to hyaline cartilage. The porous nontoxic materials of both biologic and synthetic origin have reportedly been used as matrices for repairing bone and cartilage. Following implantation, carbon fibre, chemically inert and well-tolerated by the body, induces a proliferation of ordered fibrous tissue. We implanted carbon fiber pads in osteochondral defects in rabbits. Those repairs were compared to control holes with no implants. The pads appeared to induce the gross appearance of a restored joint surface, mechanically strong to loading for periods from 2 to 6 weeks. Also, carbon fiber pads promoted the healing of the osteochondral defects in the rabbit femoral condyle, supplying well-organized cartilagenous tissue over repaired subchondral bone. The use of carbon fiber pads as implant material is suggested for the restoration of articular surface in osteoarthritis and osteochondritis dissecans.

Animals↗
PubMed1991

Effect of sodium hyaluronate on prevention of osteoarthritis.

The changes in the surface of articular cartilage of femoral condyle from rabbits were evaluated after degenerative changes were made by the technique advocated by Hulth. The medial collateral and both cruciate ligaments were excised, and a medial menisectomy was done. Then the right knee joint was injected with 1 ml of Na-hyaluronate gel every two weeks. The animals were sacrificed at two, four, six, eight, or sixteen weeks postoperatively. After sacrifice, the medial femoral condyle was excised and prepared for the light microscopic and scanning electron microscopic study. At eight to sixteen weeks, there were chondrocyte clones with clefts to the radial zone and increased loss of the height of articular cartilage on the control side; but, on the experimental side there was a significant delay and lessening of the arthritic response. The biocompatibility and the protective effect of joint degeneration of this device make this material a valuable adjuvant in the treatment of osteoarthritis and the traumatized joints.

Animals↗
PubMed1991

Anterior interbody fusion for spondylolisthesis.

We evaluated the clinical and radiologic results and the immobilizing effect of the Knight-Kim brace for bony union in 75 consecutive cases of spondylolisthesis treated by anterior interbody fusion. The fifth lumbar vertebra was the most common site involved (55%). The patients were followed for a minimum of 2 1/2 years (range: 2 1/2 to 14; average: 4.5). All cases were approached retroperitoneally, and autogenous bone graft was obtained from the iliac crest. The donor site was reconstructed by polymethylmethacrylate bone cement. Among the 75 cases of grade I, II, and III slippage according to Meyerding's grading system, 58 cases (77%) showed complete bony union after 1 year follow up. Excellent and good clinical results were obtained in 65 cases (87%) at 1 year postoperatively. The state of bony union did not always correlate with the clinical symptoms. We conclude that the simple Knight-Kim back brace was valuable for postoperative immobilization.

Adult↗
PubMed1990

Deltoid sensory flap.

Eight patients were treated using the deltoid sensory flap for soft-tissue injury of the extremities. The results were one-stage reconstructions of soft tissue extremity injuries. Protective sensibility was provided to the reconstructed area; there was no limitation of motion of the shoulder after the procedure; and primary closure of the donor site was feasible. The advantages of the deltoid sensory flap exceed those of other reconstructive procedures that are used in areas where sensibility is essential.

Adolescent↗
PubMed1990

3-D model of vascular network in rat skin obtained by stereo vision techniques.

The quantitative analysis of the depth of injury, penetration of therapeutic agents in tissues, and the regeneration of vascular patency after a graded degree of thermal injury requires a knowledge of the shape and spatial configuration of the vascular networks in the tissue. We have applied computational stereo vision techniques to describe the 3-D configuration of microvessels in full thickness rat skin vascular casts produced by perfusion of Yellow Microfil latex solution through the aorta. The principal concern is to describe the 3-D structure of vascular networks using a set of 3-D space curves. This representation is computed by integrating monocular and binocular processing; the 2-D curve representation of blood vessels computed through monocular analysis is integrated with disparity data to yield a space curve representation for each vessel. A connection diagram is also computed to indicate the connections existing among the computed space curve representations.

Algorithms↗
PubMed1990

Treatment of bone tumors around the shoulder joint by the Tikhoff-Linberg procedure.

The Tikhoff-Linberg procedure is a limb-sparing surgical option to be considered for bony and soft tissue tumors in and around the proximal humerus and shoulder girdle. The authors reported 6 cases of the Tikhoff-Linberg procedure for tumors around the shoulder joint at the Department of Orthopedic Surgery of Severance Hospital from March 1988 to May 1989. The results of the study are as follows: The 6 cases were composed of: osteogenic sarcoma 2 cases, chondrosarcoma 2 cases, chondroblastoma 1 case, and giant cell tumor 1 case. The tumors were completely removed by the Tikhoff-Linberg procedure without amputation or disarticulation of the upper extremity. The distal clavicle, upper humerus and part of all of the scapula were resected. The Tikhoff-Linberg procedure was performed for patients whose tumors did not involve the neurovascular bundle in the axilla. The function of the hand and forearm after the Tikhoff-Linberg procedure was nearly normal in all cases. The Tikhoff-Linberg procedure would be recommended as a limb-sparing operation for tumors around the shoulder joint that require wide resection without disarticulation or forequarter amputation of the upper extremities.

Adolescent↗
PubMed1990

Congenital dislocation of the hip--a long-term follow-up in Korea.

The results of fifty-eight congenitally dislocated hips in fifty-four children, who were between two months and eleven years old when treatment was begun, have been reviewed. Thirteen hips were treated by closed reduction, seventeen hips by open reduction, seventeen hips by Salter's innominate osteotomy, five hips by Klisic operation, and six hips by other operations. At an average 5.1 year follow-up (range, three to twelve years), a 91% satisfactory result was obtained when treatment was started under two years of age. With preoperative traction, in the cases when the femoral head was pulled down below to the zero station, the clinical result was satisfactory in 83%. We think that the treatment of congenital dislocation of the hip should be started before two years of age and that the femoral head should be pulled down below to the zero station to prevent avascular necrosis, and to obtain a satisfactory result.

Age Factors↗
PubMed1990

Autolysed antigen-extracted allogeneic bone for repair of diaphyseal bone defects in rabbits.

Autolysed antigen-extracted allogeneic bone (AAA bone) was used to bridge a large osteoperiosteal gap in the diaphysis of the radius of 50 rabbits. Periodic observations of the graft were made clinically, radiologically and histologically every week up to fourteen weeks. The continuity of the radius was evaluated macroscopically and histologically. The AAA bones were progressively resorbed and replaced by the new bone. The bone remodelled to the mature tubular bone and did not undergo absorption during the experimental period. The AAA bone proceeded to be an osteoinductive and osteoconductive material. There were no appreciable histologic signs of immune or foreign body reaction.

Animals↗
PubMed1990

Spinal cord injury caused by a stab wound--a case report.

The authors present a case of incomplete spinal cord injury (Brown Sequard syndrome) after a stab wound. A direct history and examination revealed that the patient was stabbed in the back while fighting with his friends. He immediately lost motor and sensory function in the lower extremities and collapsed to the ground. The patient was given primary closure after wound toilet and was treated with antibiotics. With rehabilitation he became ambulatory with a cane and long leg brace two months after the stabbing.

Adult↗
PubMed1990

An experimental study on prevention of postlaminectomy scar formation.

In repeat lumbar surgery for failed back syndrome, well organized fibrous scar tissue is often noted, binding together the dura, nerve roots, and paraspinal muscles. An animal experimental study was done to investigate the prevention of scar formation after lumbar laminectomy by using dacron and sodium hyaluronate. The experimental animals consisted of three groups: 1) control group, 2) D group (covering the laminectomy defect with dacron sheet), and 3) H group (covering the laminectomy defect with sodium hyaluronate gel). Animals were sacrificed at varying intervals (3-12 weeks) and the lumbar spines were evaluated with histologic preparations. Scar adhesion to the dura was most significantly suppressed in the D group, followed by the H group and the control group.

Animals↗
PubMed1989

Clinical significance of the immunological tests in rheumatoid arthritis.

Of the many theoretical causes of rheumatoid arthritis(RA), the most widely held theory is the autoimmune mechanism. In order to clarify the clinical significance of the immunological tests in RA, we studied immunoglobulin and complement levels in sera and synovial fluids of 118 RA patients and the following results were obtained. 1) The levels of immunoglobulins were elevated in both serum and synovial fluid and this was more prominent in the seropositive cases than the seronegative ones. 2) The levels of C3 component were decreased in both serum and synovial fluid, while those of C4 were decreased only in synovial fluid. Serum C3 and C4 component levels were more decreased in the seropositive cases than the seronegative ones. 3) The immunoglobulin levels in serum (IgG, IgM and IgA) and synovial fluid (IgG and IgA) and the levels of C3, C4 component in serum were well correlated with the clinical forms of rheumatoid arthritis. 4) The IgA level in serum and IgM level in synovial fluid were more increased in the exacerbated cases than the chronic ones. 5) Serum IgG level was decreased after steroid medication over one month.

Arthritis, Rheumatoid↗
PubMed1987

A microcomputer-based vision system for area measurement.

A vision system for measuring the area of an arbitrarily shaped object is described. The algorithm consists of a gray-level thresholding technique combined with a region correction procedure based on mathematical morphology. All processing steps are carried out on a microcomputer system equipped with a video digitizer. The algorithm has been successfully applied to a number of images of medical interest including skin wounds and various microscopic-scale objects such as cell cross-sections and multicellular tissues. Excellent agreement between results obtained by the automatic method and by using standard mechanical means has been established experimentally. The approach is demonstrated by a number of experimental examples.

Algorithms↗