Biomedical subjects

C H Yung

Publications and source records attributed to C H Yung.

At least 37 records · Page 2Linked to original sources

PubMed1991

Platelet crossmatching with lymphocytotoxicity test: an effective method in alloimmunized Chinese patients.

Fifty-three patients receiving long-term platelet transfusions were regularly screened for platelet-associated antibodies by a platelet suspension immunofluorescence test (PSIFT) and a lymphocytotoxicity test (LCT). Subsequently, 24 patients became alloimmunized; all of their antibodies were of HLA specificity. Eighty-two single-donor platelet transfusions were given, and the clinical responses were considered satisfactory if the 18-hour corrected count increment was 7.5 x 10(3) per microL or higher. In the meantime, 82 pairs of patient sera and donor lymphocytes were crossmatched. Among 63 crossmatched transfusions, 53 (84%) resulted in a satisfactory increment, with a mean (+/- SEM) of 17.71 +/- 1.96 (x 10(3)/microL), and 10 did not result in a satisfactory increment. The increments after 19 unmatched transfusions and 25 random-donor (uncrossmatched) transfusions were 0.7 +/- 0.3 and 2.39 +/- 0.66, respectively. The difference was not significant (p greater than 0.05). The agreement between the LCT results and clinical response was 88 percent. Retrospectively, the corrected count increments showed no significant differences (p greater than 0.05) among three groups of HLA grading: the increments for A/BU/BX, C/D, and random HLA matches were 22.97 +/- 4.07, 15.1 +/- 1.97, and 14.85 +/- 2.04, respectively. These results suggest that platelet crossmatching by LCT is an effective method for use in alloimmunized patients, especially Chinese patients.

Blood Grouping and Crossmatching↗

PubMed1991

Successful management of alloimmunized patients by transfusing HLA compatible and crossmatched platelets.

An average of three (range 0-22) perfect matches for 65 patients could be found in 1490 filed HLA-typed donors. It could increase to 8.7 (0-45) if strong cross-reactive antigens were added. Three methods of platelet crossmatching, i.e, lymphocytotoxicity test (LCT), platelet suspension immunofluorescence test (PSIFT) and solid phase red cell adherence test (SPRCA), were used to search for compatible donors. Forty episodes of apheresis platelet transfusion were evaluated in seven patients. Using one-hour posttransfusional corrected count of increment (CCI), greater than 7500 microliters as a guideline to assess the reliability of these three methods, we found that the efficiency of PSIFT, LCT and SPRCA were 67.5%, 97.5% and 97.5% respectively. Retrospectively, we did the HLA-A, B typing of those matched donors. There was no significant difference in CCI among different HLA match grades. The concordance of LCT and SPRCA was 100%, indicating that all the antibodies were of HLA specificity and there was no platelet specific antibody. We concluded that HLA donor-file and platelet crossmatching technique could be used together in selecting suitable donors for alloimmunized patients.

Antibody Formation↗

PubMed1991

Platelet antibody screening in patients with leukemia and aplastic anemia.

Twenty-three patients with leukemia and ten patients with aplastic anemia who needed long-term platelet transfusion were regularly screened for platelet associated antibodies by a combination of platelet suspension immunofluorescence test (PSIFT) and lymphocytotoxicity test (LCT). Subsequently 13 of the patients (56.5%) with leukemia and 7 of the patients with aplastic anemia (70%) became alloimmunized. The overall incidence was 60.6% (20/33). The concordance of PSIFT and LCT was 100%, suggesting that all the platelet associated antibodies were of HLA specificity. The identified antibodies were anti-A2, A11, A24, B5, B40, B46, B57, B60 and B62. Most of them were antibodies against the high frequency HLA antigens in the Chinese population. There was no dose-response relationship in the development of alloimmunization. The interval between the initiation of platelet transfusion and the development of antibody varied from 10 to 192 days. The immunization is of all or none response. In our study group, about 40% of the patients who did not develop alloantibody within six months will never do so. We concluded that platelet transfusion should not be withheld for fear of alloimmunization and that HLA matched or lymphocytotoxic compatible platelet-donors may be helpful to alloimmunized patients.

Adolescent↗

PubMed1991

Hemolysis after ABO-incompatible platelet transfusions.

An 18 year old girl, with acute myeloid leukemia, developed progressive hemolysis after receiving multiple transfusions with ABO-incompatible platelets. It was caused by passive transfusion of anti-A and -B isoagglutinin from the donor plasma. Her hemoglobin level returned to normal after giving group compatible or pooled and reduced volume platelet concentrates. Transfusing group-incompatible platelets is not contraindicated, but donor plasma reduction should be considered for those patients who need prolonged platelet support. Testing for isoagglutinin titer in group O donors is an alternate method to reduce the incidence of plasma-induced hemolysis in group-incompatible platelet transfusions.

ABO Blood-Group System↗

PubMed1991

HIV, HBV and HCV seropositivity in hemophiliacs.

Eleven cases of severe type hemophiliacs who had received long-term factor VIII injections were tested for the serological markers of human immunodeficiency virus (HIV), hepatitis B virus and hepatitis C virus (HCV). The period of factor VIII concentrate injections ranged from 2 to 32 years. The seropositive rates of HIV and HCV were 9/11(82%) and 11/11(100%), respectively. The seropositive rate of hepatitis B surface antigen was only 1/11(9%), while the seropositive rates of antibody to hepatitis B core antigen and antibody to hepatitis B surface antigen were 9/11(82%) and 7/11(64%), respectively, Although the patients had no symptoms related to acquired immunodeficiency syndrome, they were noted to have inverted helper/suppressor T-lymphocyte ratio, suggesting that hemophiliacs with long-term factor VIII injections have a high incidence of HIV and HCV infection, with immunological aberration.

Adult↗

PubMed1991

[The property of filamentous hemagglutinin of Bordetella pertussis].

For the purpose to clarifying the biologically active substance of B. pertussis, we prepared the filamentous hemagglutinin (FHA) from culture supernatant of the strain Tohama phase I and purified it through chromatography columns of hydroxylapatite, fetuin-Sepharose 4B and Sepharose CL 6B. There are several bands appeared in the polyacrylamide gel after SDS-PAGE, especially between 98 kD and 210 kD. The amount of 210 kD component is not proportional to hemagglutination (HA) activity of FHA among five different lots. Irons et al. reported that FHA preparation degraded the 220 kD and 210 kD polypeptides during the storage would be reduced the specific HA activity. Our result pointed out that the HA activity of purified Foffdid not relate to 210 kD component only. For the quality control of FHA purity in the B. pertussis acellular vaccine, we suggest that it would be necessary to test both HA titer and SDS-PAGE results.

Adhesins, Bacterial↗

PubMed1990

Induction of thymidine kinase activity and clonal growth of certain leukemic cell lines by a granulocyte-derived factor.

Normal polymorphonuclear neutrophils (PMNs) constitutively secrete a mediator designated granulocyte-derived factor (GDF) that can enhance the uptake of 3H-thymidine (3- to 20-fold) by the molt-3, CTV-1, and K562 leukemic cell lines in a dose-dependent manner. GDF is heat labile (56 degrees C for 30 minutes) and acid labile (pH 2.0) and is sensitive to treatment with bacterial protease type IV. Our preliminary studies suggest that GDF is non-dialyzable (molecular weight cutoff, 12,000), binds to diethylaminoethyl (DEAE), and has an apparent molecular weight (mol wt) of about 40 Kd. Production of GDF is unaffected by treatment of PMN with activating agents (interferon gamma, OK432, phorbol ester, calcium ionophore, poly I:C) or metabolic inhibitors (actinomycin-D and cyclohexamide), suggesting that GDF is constitutively secreted. Despite the marked enhancement of 3H-thymidine uptake, cell number and the rate of DNA synthesis in GDF responsive cultures remain unchanged. In contrast, the clonogenic efficiency of the responsive cells is greatly increased in the presence of GDF. These phenomena occur in parallel to an amplification of the level of thymidine kinase activity in the sensitive cells. GDF is distinct from a panel of different lymphokines and monokines in antigenicity and biochemical and functional characteristics, and is possibly a novel cytokine that can alter the pattern of DNA synthesis and growth characteristics of certain hematopoietic cells. However, its biologic and physiologic significance remains to be determined.

Biological Transport↗

PubMed1990

Iron overload in Chinese patients with hemoglobin H disease.

We examined the iron status of 23 adult patients with hemoglobin H (Hb H) disease. None of them had received multiple blood transfusions or prolonged iron therapy. Studies included serum iron and ferritin concentrations, transferrin saturation, a desferrioxamine test, computed tomography (CT) scan of the liver, and liver biopsy. Iron overload was found in 17 patients (73.9%), especially in males and in patients with splenomegaly (92.9% and 100%, respectively). Four patients with excessive alcohol consumption had clinical manifestations of severe iron overload. Idiopathic hemochromatosis associated HLA antigens, i.e., HLA-A3, -B7, or -B14, were not found in any of the 15 patients tested. These findings indicate that iron overload is common in adult patients with Hb H disease; such patients should abstain from alcohol and be considered for treatment with an iron chelating agent before irreversible organ damage occurs.

Adult↗

PubMed1990

Iron overload in untransfused patients with hemoglobin H disease.

Two Chinese patients with hemoglobin (Hb) H disease without a history of blood transfusion developed iron overload at the age of 45 and 53 years, respectively. Human leukocyte antigen (HLA) system types of these 2 patients were A19, A11, B13, B62 and A2, A24, BW55, respectively, which are not related to the common haplotypes for idiopathic hemochromatosis. Since severe iron loading is a rare clinical manifestation in untransfused patients with Hb H disease, the iron overload in both patients may be due to environmental or underlying genetic factors.

Humans↗

PubMed1990

[Setting up a CMV negative donor file].

Cytomegalovirus (CMV) infection is serious to immunocompromized individuals such as recipients of bone marrow transplantation, preterm infants and other immunosuppressed patients. Since there is no effective treatment as yet, prevention is the most effective way so far to avoid CMV infection. Blood transfusion is one of the dangerous sources and screening for CMV negative donors is mandatory, therefore, to provide blood components for immunocompromized patients. We have screened 2,015 donors at various ages for CMV antibody by using passive latex agglutination test (PLA). The results showed that the CMV antibody positive rate was 91.7% in Taiwan. It differs from those of the western countries (40-79%) and the countries of Africa and Asia (96-100%). It has also shown that the positivity rate is closely related to the age of donors. The seronegative rates of ages among 18-20, 21-30, 31-40, 41-50 and 51-60 years old were 10.7%, 9.8%, 3.9%, 1.2% and 0% respectively. It has suggested thus that the older the donor is, the higher the seropositive rate will be. Therefore, we should choose the donors of younger age as candidates for making CMV negative donor file.

Adolescent↗

PubMed1990

Hemoglobin H disease complicated iron overload and HLA expression in Chinese.

HLA-A,B antigens were typed in 15 patients with Hemoglobin H disease; 10 of them had iron overloading. No significant HLA antigen specificity was identified to be at risk as compared with 170 controls. However, HLA-A11 was suggested to have significant negative risk, and may have a protective effect. (RR = 0.1, p = 0.0015). It seems that increased iron absorption in Hemoglobin H disease is not genetically associated with idiopathic hemochromatosis and certain HLA antigen expressions.

Adult↗

PubMed1990

Clinical application of therapeutic hemapheresis.

Hemapheresis has been used in a variety of clinical states, primarily for its ability to remove an offending component, likely be either plasma or cellular elements. We have reviewed 43 cases of therapeutic hemapheresis over the past two years at Veterans General Hospital. There were 20 cases of plasmapheresis, 7 cases of leukapheresis and 16 cases of thrombocytapheresis. Most of them had satisfactory and desirable effects except a few cases in therapeutic plasmapheresis. Among 20 cases of therapeutic plasmapheresis, all but 2 cases of systemic lupus erythrematosus had transient clinical improvement. Average decrease of leukocyte count in 11 procedures of leukemic patients was 37%. As for the myeloproliferative disorders with thrombocytosis, the average drop of platelet count was 41%. The side effects of therapeutic hemapheresis were not infrequent. There were 56 recorded side effects with one sudden death among 94 procedures. Hemapheresis is useful in certain clinical conditions but more judicious application should be considered.

Blood Component Removal↗

PubMed1990

Family study of Rh haplotype frequencies in Taiwan.

Two hundred and two families (404 parents and 448 children) were typed for Rh antigens. The most common Rh haplotype is R1R1 followed by R1R2 and R1r. R1r', R2r', R0r', R0r and r'r are all very rare. The results of observed and expected haplotype frequencies do not differ significantly except few rare phenotypes. However, there are some major differences between Caucasian and Chinese populations in certain Rh genotypes. Although r is the second common genotype in Rh system among Caucasian but is rather rare in Chinese.

Chi-Square Distribution↗

PubMed1990

HLA haplotype frequencies of Taiwan-Chinese families.

HLA haplotype frequency was studied by typing 201 members of 32 unrelated families. Linkage disequilibrium was determined by observed and expected haplotype frequencies. The two-locus haplotype frequencies with most significant linkage disequilibrium were A30-B13, Aw33-B17, Bw46-Cw11, B12-Cw8, A1-Cw6 and A33-Cw3. No locus recombination was noted among 137 children.

Asian People↗

PubMed1989

Alloantibodies other than anti-D in pregnant women.

Alloantibodies other than ant-D in two primigravidas have been reported. There was no history of exposure to risk factors. One of these primigravida developed anti-E and anti-c of IgM specificity and another developed anti-Jkb of IgG specificity. No evidence of hemolytic disease of the newborn was noted in both cases. From the family studies of both cases, the maternal alloantibodies seem to have been induced by the fetal red cell antigens. Although alloantibodies can occur in primigravidas, the incidence is very low. It seems unnecessary to do routine prenatal antibody screening in our population.

Female↗

PubMed1989

[Blood group phenotyping and their application in Taiwan].

During the 1950's and 60's as new blood group systems were identified, antigen distribution studies were performed in Europe and North America among Caucasians and American Blacks. However, to date only limited studies have been performed in Africa and Asia. Because of lack of knowledge of the antigen distribution of most other than ABO and Rho (D) blood group systems within these areas and among the people of non-Caucasian races, questions of testing needs and problems have occurred. In recent years, three big matters have been encountered off and on in blood banking in Taiwan. First, multiple-transfusion recipients develop so many alloantibodies that finding compatible donors becomes a difficult task. Second, since bone marrow transplantation technology is being instituted in many teaching hospitals, it is a task of blood banks to monitor the antigen changes of other blood group systems (including of Rh system other than D) before and after transplantation. Third, more than enough disputed paternity cases that can not be resolved by simple ABO testing. Therefore, blood banks should be staffed with suitable backgrounds to cope with the procedures needed for analysing all blood group antigens. In order to resolve all the problems effectively, we ran the tests for blood group antigens other than ABO and D in our blood bank from 1984 to 1986. A total of 31 sets of antisera were used to identify the specificity of 13 blood group system antigens of the Chinese population ranging from 99 to 2257. Based on the datum obtained, we found a significant difference between Chinese and Caucasians in the distribution of eight blood group systems (Rhesus, MNSs, Kell, Duffy, Kidd, P, Lutheran and Colton). The antigen frequency of Fya and s are 99.74, 99.91 respectively. The results are higher than those of the Caucasian population. On the other hand, Fyb and S are 9.22 and 6.56, much lower than those in Caucasians. We found no K, Lua and Cob antigens among the Chinese. We conclude that this study is a significant contribution to the knowledge of blood group antigen systems and antigen distribution, and also will benefit this population in many areas of medical care.

Adolescent↗

PubMed1989

Treatment of severe aplastic anemia: comparison of bone marrow transplantation to immunotherapy.

Between February 1985 and May 1988, sixteen patients with severe aplastic anemia (SAA) post multitransfusion were treated with either allogeneic bone marrow transplantation (BMT) (9) or immunosuppression (7). The latter group was further divided into two subgroups: horse anti-human thymocyte-lymphocyte globulin (ATG-ALG) (2) and high dose methylprednisolone (HDMP) (5). There were 8 males and 8 females, age ranged from 10 to 35 years for the BMT group and 19 to 56 for the immunosuppression group. As of analysis, 9 patients in the BMT group had been followed from 1 to 31 months after transplant (median,24). Graft rejection was noted in 2, both had positive mixed lymphocyte culture (MLC) index. Seven had full recovery of hematopoiesis. Of these 7 survivals, none developed acute graft-versus-host disease (GVHD), whereas 2 had chronic GVHD which resolved completely after a 9-month treatment with azathioprine and prednisolone. Kaplan-Meier survival probability at 31 month was 75%. In the immunosuppressive therapy group 2, who received ATG-ALG both failed the treatment, died 7 and 29 months later, respectively. There were 3 responders in the HDMP subgroup, 1 complete, 2 partial. The 1-year survival probability for this group was 42.9% compared with 75% in the BMT group (p greater than 0.10). However, the hematologic reconstitution and Karnofsky performance were complete in all 7 transplant survivals vs one of 3 in the immunosuppression group (p less than 0.01). This experience supports that for patients with SAA under the age of 40, BMT is the treatment of choice if an HLA-identical MLC-nonreactive marrow donor is available, if not, immunosuppression is an alternative approach.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

Release of colony-stimulating activity by resting and activated monocytes, T cells and B cells.

Purified populations of monocyte, T lymphocyte, and B lymphocyte from normal human peripheral blood were used for the investigation of elaboration/release of granulocyte-macrophage colony-stimulating activity (GM-CSA). Cell separation was performed by a series of techniques including density-cut centrifugation, adhering incubation, carbonyl iron ingestion and E rosette formation. The purity of the isolated cell population was over 95% with a mean viability of 98%. After collection, the cells were resuspended at a concentration of 1 x 10(6)/ml in RPMI-1640 medium containing 5% fetal calf serum and incubated for 7 days at 37 degrees C to prepare conditioned media (CM) for assay of GM-CSA. The results showed that the monocytes could constitutively secrete a considerable amount of GM-CSA, whereas no CSA was produced by T cells or B cells under normal conditions. All the three cell populations released GM-CSA when activated by mitogen stimulation. Monocyte-derived GM-CSA production was greatly enhanced by zymosan (Zym), lipopolysaccharide (LPS) and concanavalin A (Con A), resulting in an augmentation approaching 3 to 4 times the untreated control. For T lymphocytes, the most contributive stimulants to induce GM-CSA release were phytohemagglutinin (PHA) and Con A, while Zym and LPS were not effective. B lymphocytes, after treatment with pokeweed mitogen (PWM) or PHA, were also capable of releasing large amounts of GM-CSA with a peak level near to PHA-stimulated T lymphocytes. The finding suggested that, when activated, B cells may participate in the inflammatory response and in the regulation of granulopoiesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗