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Biomedical subjects

D Chandanayingyong

Publications and source records attributed to D Chandanayingyong.

At least 37 records · Page 2Linked to original sources
PubMed1995

The presence of the HLA class II allele DPB1*0501 in ethnic Thais correlates with an enhanced vaccine-induced antibody response to a malaria sporozoite antigen.

In this study, we examined the correlation between the frequency of allelic variants of the class II human leukocyte antigen (HLA) DR, DQ and DP gene loci and the quantitative humoral immune response observed in 71 Thai volunteers, subsequent to vaccination with a conjugated subunit vaccine. This vaccine was designed to induce antibodies directed against the immunodominant repeat region of the Plasmodium falciparum circumsporozoite (CS) protein. The presence of the DPB1*0501, a relatively common allele in Asian populations, was found to be associated with high vaccine-induced CS repeat-specific antibody responses in the volunteers. Given the increasing focus on the use of subunit vaccines in the control of infectious diseases, consideration of the influence of class II allele frequencies in ethnically diverse recipient populations may be important.

Adult↗
PubMed1995

Collection of cord blood stem cells for transplantation in thalassemic patients.

Thalassemia is widely distributed throughout the world and is one of the major public health problems. The use of bone marrow transplantation, the only curative therapy for thalassemia, is limited because less than 30% of the patients have unaffected and HLA-identical siblings as donors. Cord blood stem cells, an alternative source of stem cells for transplantation, have been successfully transplanted into patients with several diseases after myeloablative therapy. Twenty cord blood samples from unaffected neonates whose siblings had severe thalassemia were collected. The median volume was 80 ml. The median number of cells and colony forming units-granulocyte-macrophage in cord blood was 9.2 x 10(8) and 3.4 x 10(5), respectively. Four of 20 cord blood samples had HLA-matched to the affected siblings. One patient underwent cord blood transplantation with success; one patient is waiting for transplantation.

Blood Specimen Collection↗
PubMed1994

HLA-DPB1 polymorphism in the Thais of Southeast Asia.

In this study we examined DPB1 allele frequencies in five ethnic Thai populations resident in different regions of Thailand and neighboring countries. In contrast to other Asian and Pacific populations such as the Japanese, Chinese, Korean, and Papua New Guineans, where DPB1*0501 has consistently been shown to be the most frequent allele, NE Thais and Thai-Khmers demonstrate a prevalence of DPB1*1301. Comparison of DPB1 allele frequencies in the Thais of SE Asia, with known frequencies in the Chinese and Japanese populations of E Asia, would appear to confirm previous calculations of genetic divergence between these Oriental populations.

Alleles↗
PubMed1994

Potential deferral criteria predictive of human immunodeficiency virus positivity among blood donors in Thailand.

BACKGROUND: To develop deferral criteria to prevent human immunodeficiency virus (HIV) transmission by recently infected blood donors in the seronegative "window" phase, routine data on donors at a university hospital were examined for factors predicting seropositivity. STUDY DESIGN AND METHODS: Records of all 281 HIV-positive blood donors from August 1987 through September 1991 were retrospectively compared with those of 1076 randomly selected control donors matched only by year of donation. Four controls were selected for each HIV-positive donor. RESULTS: The prevalence of HIV in 102,684 donor units during the period rose from 0.02 percent in 1987 to 0.52 percent in 1991. Multivariable analysis revealed that male sex (odds ratio [OR] = 26.4), VDRL test positivity (OR = 3.0), age 21 to 30 years (OR = 2.2; referent: 16-20-year-old group), and replacement donorship (OR = 1.4; referent: voluntary donors) were independent factors significantly associated with HIV positivity among these donors (p < 0.05). Since replacement donorship cannot be avoided, only male sex, age 21 to 30 years, and VDRL test positivity were considered as potential criteria. When these findings were extrapolated to all donors in 1990 and 1991, those with all three or only two (excluding VDRL test, because the results are known only after donation) of these high-risk factors had HIV positivity probabilities of 2.2 and 1.0 percent, respectively. These probabilities were, respectively, 4.9 times (95% CI: 2.9 8.3) and 4.1 times (3.1, 5.4) the risk among other donors. However, applying such criteria would have eliminated 1.5 and 31.2 percent, respectively, of all HIV-negative donors in 1990 and 1991. The latter deferral proportion is too high to be acceptable. CONCLUSION: In Thailand, improved donor deferral criteria addressing sexual risk factors could lead to decreased probability of window-period donation, with an acceptable rate of deferral. Additional p24 antigen testing may be indicated for donors at increased risk for HIV infection, specifically, men aged 21 to 30.

Adolescent↗
PubMed1993

Factor VIII, factor IX and fibrinogen content in cryoprecipitate, fresh plasma and cryoprecipitate-removed plasma.

In order to provide accurate information for physicians, factor VIII, factor IX and fibrinogen content were determined in 40 bags of cryoprecipitate, fresh plasma and cryoprecipitate-removed plasma. A cryoprecipitate bag with a volume of 21.8 +/- 5.3 ml contained 139.5 +/- 42.9 units of factor VIII and 200.0 +/- 80.0 mg of fibrinogen. Fresh plasma with a volume of 208.0 +/- 22.5 ml contained 180.9 +/- 45.3 of factor IX, significantly higher than in cryoprecipitate-removed plasma. It was also found in this study that group O blood showed a significantly lower level of factor VIII.

ABO Blood-Group System↗
PubMed1993

Preoperative autologous blood collection and haemodilution with gelatin solution (gelifundol).

Autologous blood collection and haemodilution with gelatin solution had an effect on the decrease in red blood cells, haemoglobin, haemotocrit, fibrinogen and platelets; however, this technique had no effect on coagulograms, platelet function and haemostasis. In conclusion, this technique is suitable and possibly practical in obtaining sufficient blood for elective surgical patients and is without any undesirable side effects.

Adolescent↗
PubMed1993

Bone marrow transplantation for thalassemia in Thailand.

We report our experience of bone marrow transplantation for thalassemia in Thailand. From July 1988 to September 1992, 10 thalassemic patients underwent allogeneic bone marrow transplantation. Two of them were homozygous beta-thalassemia and 8 were beta-thalassemia/Hb E disease. Seven were male and 3 female. The age ranged from 1.8-14 years. The conditioning regimen comprised busulfan 14 mg/kg and cyclophosphamide 200 mg/kg. For GVHD prophylaxis, either cyclosporine alone or in combination with short methotrexate was given. Five patients were alive and well 104-1534 days after transplantation. Three patients with severe manifestations at the time of transplant had partial engraftment, and lost their graft within 3 months. They survived with thalassemia 1041-1357 days after transplantation. One patient who received one antigen mismatched marrow from her brother had no engraftment and was alive with thalassemia 1429 days posttransplant. One patient died early on day 9 from CNS complication. No GVHD was observed in this series. These results indicate that bone marrow transplantation can cure thalassemia but there is still high autologous recovery rate in those with severe manifestations.

Adolescent↗
PubMed1990

Massive chemotherapy and autologous bone marrow transplantation in Burkitt's lymphoma: the first two patients successfully treated in Thailand.

Massive chemotherapy and autologous bone marrow transplantation (ABMT) have been successfully used for the treatment of Burkitt's lymphoma. We report our first success with such treatment in two children with Burkitt's lymphoma in Thailand. Both patients had massive abdominal tumors with ascites and minimal bone marrow metastasis at the first presentation. They received induction chemotherapy and intensive treatment including central nervous system prophylaxis with cranial irradiation and intrathecal methotrexate until being in complete remission before starting massive chemotherapy, comprising the combination of BCNU, cytosine arabinoside, cyclophosphamide and 6-thioguanine followed by ABMT. Both patients recovered completely following intensive supportive treatments post ABMT and are still good health without evidence of the disease for 18 and 8 months after transplantation respectively. The role of massive chemotherapy and ABMT for the treatment of non-Hodgkin's lymphoma especially Burkitt's lymphoma was discussed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Immune responses to the circumsporozoite protein of Plasmodium falciparum in relation to HLA-DR type.

Associations between HLA-DR/DQ phenotypes and immune responses to the circumsporozoite (CS) protein of the human malaria parasite, Plasmodium falciparum, were investigated in Thai adults. The frequency of DR and DQ types did not differ between 15 high antibody responders and 16 antibody non-responders. Initial results which suggested that lymphocyte responses to a CS-derived peptide (R32tet32) might be HLA-DR associated were not confirmed by subsequent extension of the study. Thus, MHC restriction appears not to be a major factor in the frequently observed unresponsiveness of the immune system to the P. falciparum sporozoite. Based on these results, it is expected that MHC restriction will not be a major obstacle to the application of a malaria vaccine in outbred human populations.

Adult↗
PubMed1988

HLA antigen profiles in Thai tuberculosis patients.

HLA antigens were studied in 35 Thai patients suffering from active pulmonary tuberculosis. An increase in the frequency of HLA-Bw46 and -DR4 and a decrease in the frequency of HLA-B12 were found when compared with the matched controls. These findings suggest that the pathogenetic role of HLA-B12 is to confer resistance and that HLA-Bw46 and -DR4 are associated with susceptibility. In addition it provided further information on HLA antigen profiles in pulmonary tuberculosis patients in another ethnic group (viz. Thais). Conclusions regarding genetic control over therapeutic efficacy must await further study.

Adolescent↗