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Biomedical subjects

N H Choi

Publications and source records attributed to N H Choi.

At least 19 recordsLinked to original sources
PubMed2001

Semitendinosus tenodesis for medial instability of the knee.

A new technique of semitendinosus tenodesis has been developed to treat medial instability of the knee. The semitendinosus tendon was sectioned at the musculotendinous junction. The accessory insertion of the tendon was dissected to be overlapping and parallel to the anterior band of the medial collateral ligament. An isometric point on the femur was located around the medial epicondyle. A bony trough was created just above the isometric point and a screw with washer was placed. The semitendinosus tendon was looped around the screw and the screw was tightened to hold the tendon in place. The free end of the tendon was pulled obliquely backward and passed through the insertion of the direct head of the semimembranosus tendon to reconstruct the posterior oblique ligament. The semitendinosus tendon reinforced both the medial collateral ligament and the posterior oblique ligament.

Bone Wires↗
PubMed2001

Arthroscopically assisted treatment of avulsion fractures of the posterior cruciate ligament from the tibia.

BACKGROUND: The attachment of the posterior cruciate ligament to the posterior intercondylar fossa of the tibia is in a location that is difficult to access for arthroscopic surgical procedures. This report presents a variety of arthroscopically assisted reduction and fixation methods for managing avulsion fractures of the posterior cruciate ligament from the tibia. METHODS: Thirteen patients (fourteen knees) who had an avulsion fracture of the posterior cruciate ligament were treated with an arthroscopic procedure. Eleven patients underwent the operation in the acute phase (four to ten days after the injury), and two patients had delayed surgery (at nineteen and twenty months after the injury) because of nonunion. The choice of fixation method was based on the size of the avulsed fragment. Six knees that had a small bone fragment (<10 mm) with comminution were fixed with use of multiple sutures. Two knees that had a small bone fragment without comminution were fixed with 23-gauge wires. Two knees that had a medium-sized fragment (10 to 20 mm) were fixed with Kirschner wires. Four knees that had a large single fragment of bone (>20 mm) that involved the condyles were fixed with one or two cannulated screws. RESULTS: All patients had osseous union as determined on radiographs. Three injured knees in two patients showed limitation of motion after the operation. These patients had been immobilized for two or three months after the surgery because of concomitant fractures. The eleven patients who had undergone the operation in the acute phase, including two in whom postoperative arthrofibrosis had developed, showed no or trace posterior instability following the procedure. However, the two patients in whom the surgery had been delayed had residual grade-I posterior instability. The postoperative side-to-side differences, when measured with use of the KT-2000 arthrometer and posterior stress radiographs, showed better results in the patients in whom the surgery had been performed in the acute phase than in the patients in whom the operation had been delayed. CONCLUSION: Arthroscopic procedures can be used to treat tibial avulsion fractures of the posterior cruciate ligament.

Accidental Falls↗
PubMed2000

Arthroscopic treatment for localized pigmented villonodular synovitis of the knee.

This study investigated 11 patients with localized pigmented villonodular synovitis of the knee that was diagnosed and treated by arthroscopic technique. There were six male and five female patients between the ages of 15 and 59 years (mean, 34.6 years). Seven patients reported extension limitation without joint line tenderness. Four of the 11 patients had a history of trauma before the onset of knee symptoms. All patients were treated by arthroscopic resection with partial synovectomy. The most common involved site was the anteromedial synovium near the anterior horn of the medial meniscus (five patients). The remaining cases were located in the anterior fat pad (two patients), suprapatellar pouch, posteromedial compartment, medial gutter, and the anterior horn of the lateral meniscus. Nine patients had one mass, and the remaining patients each had two or three masses. There was no evidence of recurrence at followup for an average of 29.9 months (range, 24-48 months). Arthroscopy is effective in the diagnosis of localized pigmented villonodular synovitis with minimal morbidity, and complete arthroscopic excision can be considered the definitive treatment for localized pigmented villonodular synovitis.

Adolescent↗
PubMed1999

Tibial tuberosity avulsion fracture combined with meniscal tear.

Avulsion fractures of the tibial tuberosity are uncommon injuries. They usually occur during athletic activities in adolescents. The classification of these injuries has been divided into three types. Only two cases of avulsion fractures of tibial tuberosity have previously been reported with associated damages to menisci. We report a type III fracture of the tibial tuberosity associated with tear of the medial meniscus.

Adolescent↗
PubMed1998

Operative hip arthroscopy.

Twenty patients underwent operative arthroscopic procedures of the hip joint. All procedures were performed with the patient in the supine position on a standard fracture table using fluoroscopy through three arthroscopic portals (anterolateral, anterior paratrochanteric, and posterior paratrochanteric). The initial indications were therapeutic in 16 patients: loose bodies in four, synovial chondromatosis in three, rheumatoid arthritis in five, ankylosing spondylitis in one, septic arthritis in one, avascular necrosis of femoral head in one, and primary osteoarthritis in one. In four patients who had unexplained hip pain, the initial indications were diagnostic: minimal synovial change was seen in two patients, a synovial chondromatosis was present in another, and a tear of the acetabular labrum and hypertrophy of ligament teres were present in a fourth patient. In one patient who had primary osteoarthritis, the insertion of the arthroscopic instrument into the hip joint failed because of profuse osteophytes along the acetabular rim. Twelve of the 19 patients showed significant improvement of the symptoms after the arthroscopic procedure, but seven patients had no benefit from the procedure. One patient had a postoperative reflex sympathetic dystrophy.

Adolescent↗
PubMed1997

Arthroscopic reduction and fixation of bony avulsion of the posterior cruciate ligament of the tibia.

Bony avulsion fractures of the posterior cruciate ligament of the tibia have commonly been treated by open reduction and internal fixation using the posterior approach. However, this approach, using the prone position, makes it difficult to investigate and treat other combined injuries of the knee joint. We report a case of posterior cruciate ligament avulsion of the tibia that was arthroscopically reduced and firmly fixed with two cannulated screws. The posterior sag was absent after the operation and the result was excellent. By arthroscopy, we got rigid fixation of the avulsed fragment for early rehabilitation, and detection of a concomitant injury was also possible.

Arthroscopy↗
PubMed1991

Isolation of two forms of decay-accelerating factor (DAF) from human urine.

Decay-accelerating factor (DAF) was purified from human pooled urine by conventional techniques. The urine DAF was separated into two peaks, pool I and pool II, by gel chromatography. DAF-U1 was isolated from pool I by hydrophobic chromatography, and DAF-U2 from pool II by anti-DAF IgG column. The specific activities of DAF-U1 and DAF-U2 to decay membrane-phase C5 convertase were about 3% and 70% of membrane form DAF, respectively. However, both urine DAFs revealed a similar activity to each other and slightly higher activity than that of membrane form DAF in decay-accelerating fluid-phase C3 convertase of the alternative pathway.

Amino Acid Sequence↗
PubMed1991

Assignment of a human serum glycoprotein SP-40,40 gene (CLI) to chromosome 8.

SP-40,40 is a serum glycoprotein consisting of two different subunits (alpha and beta) assembled into a dimer by disulfide bonds. Northern blot hybridization, using total RNA from several cell lines, showed that SP-40,40 is expressed in glioblastoma and testicular tumor cells, as well as hepatoma cells. Spot blot hybridization of flow-sorted human chromosomes, using a SP-40,40 cDNA fragment as a probe, localized the gene for SP-40,40 to human chromosome 8. This gene has been given the designation CLI, for complement lysis inhibitor, by the Human Gene Nomenclature Committee.

Blood Proteins↗
PubMed1991

Functional and structural domains of the sixth component (C6) of human complement.

The effects of serine protease inhibitors, diisopropyl fluorophosphate (DFP) and phenylmethanesulfonyl fluoride (PMSF), on hemolytic activity of C6 were reinvestigated. C6 was inactivated in a range of 1-10 mM by both of the inhibitors as previously reported. Limited proteolytic digestion was also studied to elucidate the functional and structural domains of C6. The major fragments produced by trypsin, plasmin, or lysyl endopeptidase could not be separated unless disulfide bonds were disrupted, but Staphylococcus aureus V8 protease yielded several fragments, each of which was not linked by disulfide bond. When C6 labeled with [3H]DFP was subjected to limited digestion with V8 protease, a fragment with a molecular weight of 38 kilodaltons (kDa) was mainly labeled and other fragments of 53 kDa and 26.4 kDa were also faintly labeled, while fragment 35 kDa wasn't labeled, indicating specific domains reactive with DFP. On the other hand, when C6 with or without DFP treatment was digested with V8 protease and those fragments were incubated with C5 and subjected to sucrose density ultracentrifugation, fragments 53, 38, 35 and 27.5 kDa interacted with C5 in both cases. These results suggest that C6 modified by DFP can interact with C5, and the amino-terminal sequences of fragment 38 and 35 kDa suggest the binding domain of C6 with C5 takes place within the two short consensus repeats.

Complement C6↗
PubMed1990

Sandwich ELISA assay for quantitative measurement of SP-40,40 in seminal plasma and serum.

SP-40,40 was purified from human plasma by PEG fractionation, DEAE-Sephacel, Phenyl-Toyopearl 650M, Bio-Gel A-0.5m and hydroxylapatite chromatographies. Three monoclonal antibodies (IF12, IID9 and IVF4) to this protein were prepared: IF12 and IID9 were specific for the beta subunit and IVF4 for the alpha subunit. The concentrations of SP-40,40 in seminal plasmas and sera were determined using a sandwich ELISA method. The results showed that the average concentrations of SP-40,40 were 438 +/- 285 micrograms/ml in seminal plasmas and 111 +/- 50 micrograms/ml in sera of normal donors. SP-40,40 concentrations in seminal plasmas of Klinefelter and excretory azoospermia patients were similar to those of normal donors. However, those of oligozoospermia and idiopathic azoospermia patients were about half the normal value.

Animals↗
PubMed1990

Incorporation of SP-40,40 into the soluble membrane attack complex (SMAC, SC5b-9) of complement.

When SC5b-7 was prepared from the C8-depleted serum activated with inulin, it contained SP-40,40 as well as S-protein. From the densitometry of each component in SC5b-9 after SDS-PAGE, it was estimated that SC5b-9 was constituted of one molecule each of C5b, C6, C7, C8, S-protein, and SP-40,40 and two molecules of C9. SP-40,40 was depleted from normal serum with an affinity column using mouse monoclonal anti-SP-40,40 antibody. When the resulting SP-40,40-depleted serum was activated with inulin, SC5b-9 lacking SP-40,40 could be formed. S-Protein-depleted serum was also prepared with an affinity column using mouse monoclonal anti-S-protein antibody. Similarly, SC5b-9 lacking S-protein could be formed by the inulin activation of the S-protein-depleted serum. These results indicate that either SP-40,40 or S-protein should be able to form a soluble C5b-9 complex.

Blood Proteins↗
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

[Influence of stress experience on change of attention].

For a man to maintain attention, he needs to keep a certain level of arousal. An inordinate increase or decrease in the level of arousal eventually has a negative influence on attention. Precedent research has shown that the degree of attention changes when an experience of stress is related to anxiety resulting in a rise in arousal. This research was done to examine this hypothesis by looking at the 27 female students, 14 of whom had failed in the annual examination. The results of the investigation are as follows: The stress of failure in the examination was seen to raise the level of physiological arousal. Although pulse and electromyography showed no significant change, further inquiries should be made based on other types of methodology. In spite of the rise of arousal, the performance of selective task was degraded. This suggests those students failed to give moderate attention to given information for that kind of task. But the exact reason of that failure was not identified: that is it was difficult decide whether they gave too much attention to the anxiety brought about by stress. Performance of integral tasks, however, did not show any degradation. Judging from these results, stress seems to exert significant influence on attention in the selection of the appropriate information among the various options given. This offers an important hint in relation to the health care situation where nursing information is offered. Clients who receive nursing information in stressful situations may have difficulty in separating and selecting this helpful information from other options which they have acquired through their life experience. The content and terminology of nursing information may be strange and unintelligible to clients, although they are quite familiar and distinct to nurses. So, it is desirable for nurses to give, in addition and at the same time when nursing information is given, some certain related information as devices for selection, instead of merely giving nursing informations as such. So far it is not clear whether the concepts of information processing theory can be suitably applied to nursing. However, it is obvious, according to this research, that the quality of attention is disturbed in the stress situation. This is why further inquiries should be made into attention in practical nursing situation.

Arousal↗