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Biomedical subjects

Y S Yoon

Publications and source records attributed to Y S Yoon.

At least 55 records · Page 3Linked to original sources
PubMed1993

Liver involvement in multiple myeloma proven by peritoneoscopy--a case report.

Liver involvement in multiple myeloma has been known to be common in autopsied series. However, since its clinical significance is uncertain yet, invasive procedure confirming plasma cell infiltration of the liver has been rarely performed. We report a case with multiple myeloma which had plasma cell infiltration of a liver. A peritoneoscopic biopsy of the liver for the purpose of disclosing the nature of the aggravating liver function in a carrier of the hepatitis B virus showed infiltration of lymphoreticular cell which were identified later as lambda-light chain producing primitive plasma cells by immunohistochemical stain.

Adult↗
PubMed1993

Primary idiopathic chylopericardium: report of a case and review of the literature.

Primary or isolated chylopericardium of unknown etiology is considered a rare cause of pericardial effusion. Its etiology is obscure but certain communication between the lymphatic system and pericardial sac was suggested. Up to 1991, there was only one case report that successfully showed the direct communication by a lymphangiogram. We report a case of chylopericardium occurring in a nearly asymptomatic 22-year-old man with no apparent history of trauma, infection or mediastinal neoplasm, in which we succeeded in visualizing the communication between the thoracic duct and pericardial sac by lymphangiography and computed tomography of the chest. A review of the previous cases is described also.

Adult↗
PubMed1993

The effect of HLA mismatching on graft survival in living-donor kidney transplants: Catholic Medical Center, 1984 to 1993.

This study focuses on the beneficial effect of HLA matching on long-term graft survival rates in CsA-treated living primary kidney transplants at Catholic Medical Center, 1984 to 1993. 1. An impressive 26% difference in kidney graft survival was observed at 5 years between recipients who received 0 and 2 HLA-DR mismatches (79% vs 53%). 2. Five-year kidney graft survival rates in the 0, 1, 2, and 3-HLA-B+DR mismatches were 87%, 76%, 77%, and 74%, respectively, which was significantly different from 54% survival rates in the 4-HLA-B+DR mismatch group. 3. The 5-year kidney graft survivals in the 0, 1, 2, HLA-DR-mismatched living-nonrelated donor group were 84%, 76%, and 39%, respectively, which were significant differences. 4. The 5-year kidney graft survivals in the 0, 1, 2, HLA-DR-mismatched living-related donor group were 75%, 79%, and 72%, respectively, which were not significant. 5. The effect of HLA-A, B, A+B, A+DR, and A+B+DR mismatches showed little difference among the groups with different mismatch numbers. In conclusion, better matching for the HLA-DR, B+DR antigens significantly improved kidney graft survivals in our CsA-treated primary living-donor transplant recipients.

Academic Medical Centers↗
PubMed1992

Thrombotic thrombocytopenic purpura-like syndrome associated with systemic lupus erythematosus--combined treatment with plasmapheresis and fresh frozen plasma infusion.

We report on a patient with systemic lupus erythematosus, who, during the course of the illness, developed thrombotic thrombocytopenic purpura. In this case, the coexistence of these two conditions was confirmed by laboratory and pathologic findings. The infusion of fresh frozen plasma with plasmapheresis reversed the course of thrombotic thrombocytopenic purpura.

Adult↗
PubMed1992

Factors influencing long-term outcome of living-donor kidney transplantation in the cyclosporine era.

To evaluate the effect that CsA has had on the weight of some factors previously considered influential on kidney graft survival rates in conventionally immunosuppressed recipients, we analyzed patient and graft survival rates for 524 consecutive living-donor first kidney transplants. All patients were transplanted at the Catholic Medical Center between 1984 and 1991 and treated with CsA. The data were stratified to reflect differences in a) HLA matching; b) acute graft rejection within 3 months posttransplant; c) donor sources; d) age; e) sex; f) graft number; g) diabetics; h) HBV status; i) DST; and j) number of pretransplant transfusions. Overall actuarial 5-year patient and graft survival rates were 86% and 77%. The actuarial 5-year graft survival rates for the HLA-identical, haploidentical, and mismatched groups were 93%, 75% and 80% (p = 0.3858), respectively. The actuarial 5-year graft survival rates in recipients with acute graft rejection (< 3 months) and without acute graft rejection were 55% and 80% (p = 0.0001). The actuarial 5-year graft survival rates for the HBV-positive and -negative groups were 55% and 80% (p = 0.0048). The actuarial 5-year graft survival rates according to the number of pretransplant blood transfusions--0, 1-4, and over 5 units groups--were 65%, 80%, and 81% (p = 0.0026), respectively. We conclude that a) acute graft rejection within 3 months, b) HBV-positive, and c) pretransplant nontransfusion had a significant negative influence on long-term graft survival, whereas little or no effect was attributable to HLA matching, donor source, age, sex, graft number, diabetes, and DST.

Academic Medical Centers↗
PubMed1989

Shape optimal design of the stem of a cemented hip prosthesis to minimize stress concentration in the cement layer.

An optimal shape of the metal stem of a cemented total hip prosthesis minimizing stress concentration in the cement layer was searched for. A gradient projection method of numerical optimization and a finite element method of stress analysis were employed. A two-dimensional model of the femoral part of a total hip prosthesis was derived equivalent to a simplified three-dimensional axisymmetric model. The result of the stress analysis of the two-dimensional model compared favorably with that of the three-dimensional axisymmetric model. Using this two-dimensional model, an optimal shape of the stem, minimizing stress concentration in the cement layer, was obtained by a gradient projection method and the shape was checked again by the three-dimensional finite element analysis. The resulting optimal shape of the stem profile was in good agreement with conventional ones, except in the proximal region where a significant amount of stress reduction in the cement layer was achieved by tapering the stem to the limit that the stem still could withstand the increased stem stress.

Bone Cements↗
PubMed1989

Red cell sodium and ionic fluxes in patients with hyper- and hypothyroidism.

To investigate the status of the Na+ concentrations [Na+]i, K+ concentrations [K+]i and ionic fluxes in red cells of human subjects with abnormal thyroid function, we measured the Na(+)-K+ pump activity as well as Na(+)-K+ cotransport (CoT), Na(+)-Li+ countertransport (CTT) and Na+ passive permeability in erythrocytes of 37 normal subjects, 19 untreated hyperthyroid patients, 12 treated hyperthyroid patients and 9 hypothyroid patients with T4 replacement. The mean [Na+]i value in the untreated hyperthyroidism group was significantly higher than that in the normal subjects (p less than .05), but not significantly different from that in the treated hyperthyroidism group. The mean [Na+]i value in the hypothyroidism with T4 replacement group, however, was significantly lower than that in the normal group (p less than .01). We did not find any significant difference of [K+]i in comparing each group. It was found that the Na(+)-K+ pump activity in erythrocytes was significantly increased in untreated hyperthyroidism (mean; 23.4% above control, p less than 10(-5], but there was no significant difference in treated hyperthyroidism and hypothyroid patients with T4 replacement. The rate constant for ouabain-sensitive Na+ efflux in the hypothyroidism with T4 replacement group was markedly higher than that in normal subjects (p less than .01), but not significantly different in the untreated hyperthyroidism group. We observed a significant increase of the Na+ CoT value in the patients with untreated hyperthyroidism as compared with that of the normal subjects (p less than .05), but there was no significant difference in the patients treated for hyperthyroidism and the hypothyroidism with T4 replacement group. However, the rate constant for Na(+)-CoT in the patients with hypothyroidism with T4 replacement was significantly higher than that in normal subjects (p less than .05). We observed a marked decrease of Na(+)-Li+CTT value in the patients with untreated hyperthyroidism versus that in the normal group (p less than .01). Passive Na+ permeability in the patients with untreated hyperthyroidism was markedly increased (p less than .05), and was markedly decreased in the patients with hypothyroidism with T4 replacement compared to normal subjects (p less than .01). It can be concluded from these studies that an increase in Na(+)-K+ pump activity in the patients untreated for hyperthyroidism might then be regarded as a secondary adaptive cellular response to higher [Na+]i values due to enhanced passive Na+ permeability, rather than a direct effect of the thyroid hormone.

Adult↗
PubMed1989

Erythrocyte sodium transport in dialyzed uremic patients.

To investigate the status of the Na+ concentration and ionic fluxes in red cells of human subjects with dialyzed chronic uremia, the authors measured the Na(+)-K+ pump activity as well as Na(+)-K+ cotransport (CoT), Na(+)-Li+ countertransport (CTT) and Na+ passive permeability in erythrocytes from 37 normal subjects and 23 chronic uremic patients receiving maintenance hemodialysis. The mean intracellular Na+ concentration [Na+]i value in the pre-dialytic group was significantly lower than that in control subjects (p less than .0001), but tended to recover to the normal value of [Na+]i in the post-dialytic group. The mean intracellular K+ concentration value in the post-dialytic group was significantly higher than that of the control group (p less than .001), but not significantly different from that of the pre-dialytic group. It was found that the Na(+)-K+ pump activity of erythrocytes in the pre- and post-dialytic groups markedly decreased over that of the normal control group with statistical significance (p less than .0001, respectively). The Na(+)-K+ pump activity in the post-dialytic group, however, tended to recover, but not significantly. The rate constant for ouabain-sensitive Na+ efflux in the post-dialytic group was significantly decreased over that of the normal controls (p less than .05). The authors observed a significant decrease of the Na+ CoT value (p less than .001 respectively) and rate constant for Na+ CoT (p less than .05, respectively) in the patients with pre- and post-dialytic uremia vs. that of normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Charnley low friction arthroplasty in tuberculosis of the hip. An eight to 13-year follow-up.

We report 60 patients with tuberculosis of the hip treated by Charnley low friction arthroplasty and followed for eight to 13 years. Eight of them had active tuberculosis of the hip at the time of operation, and all were covered by relatively short courses of antituberculous drugs. Our study suggests that arthroplasty can be recommended for these patients provided that adequate chemotherapy is given both before and after operation.

Adult↗
PubMed1987

Percutaneous pulmonary valvuloplasty with a double-balloon technique.

Percutaneous pulmonary valvuloplasty with a double-balloon technique was used in eight patients, aged 10-40 years, in whom valvuloplasty with a single 20-mm balloon resulted in inadequate dilatation of the stenosis. The diameters of the additional balloon varied from 10 to 20 mm. Balloons were inflated manually at about 30-45 psi (206.7-310.1 kPa) and deflated immediately after disappearance of the balloon waist. The mean peak systolic pressure gradient was 85 mm Hg +/- 37 before valvuloplasty, and it decreased to 38 mm Hg +/- 28 afterward (P less than .05). Double-balloon dilation and simultaneous computed tomography were done in two cardiac specimens from adult cadavers. At inflations at 30 and 45 psi (206.7 and 310.1 kPa), the outflow tract was elongated, and the balloons also deformed into ovoid shape at the lower pressure. The double-balloon technique appears to be safe and effective for relief of pulmonary valvular stenosis in those cases in which single-balloon technique is inadequate, especially in older children and adults.

Adolescent↗
PubMed1986

Arthroplasty using the Charnley prosthesis in old tuberculosis of the hip. Clinical experience with 8-10-year follow-up evaluation.

Twenty patients with tuberculosis of the hip joint were treated by low-friction arthroplasty (LFA) and followed for eight to ten years. Five of the patients had reactivation of the infection and subsequent failure despite the use of chemotherapy. Successful revision arthroplasties have been performed on two of the five hips. LFA can be recommended for patients with old tuberculous hips, provided it is combined with adequate chemotherapy both before and after surgery.

Adult↗
PubMed1985

Salvage procedures in failed hip arthroplasties.

Results and observations based on a series of 90 patients who underwent revision hip arthroplasty are reported, including engineering notes on the removal of cement within the femur and assessment of the mechanisms of failure of the original arthroplasties. The authors state a preference for performing revision in two stages, and leaving original cement in the bottom of the femoral canal.

Adult↗