PubMed Health⌕ Search

Biomedical subjects

V Suvatte

Publications and source records attributed to V Suvatte.

At least 37 records · Page 2Linked to original sources

Abnormal hemostasis in dengue hemorrhagic fever.

Abstract. Abnormal hemostasis in dengue hemorrhagic fever includes:- 1. Vasculopathy which occurs during the early febrile to pre-shock and shock phase. The evidences support are: 1.1 Increased anaphylatoxin, released by complement activation causing leakage of intravascular fluid in to serous space. 1.2 Positive tourniquet test, some of which occur preceeding thrombocytopenia in the acute phase of DHF. 1.3 Excessive increased in PGI2 which is the most potent vasodilator and platelet aggregation inhibitor. 2. Platelets: 2.1 Thrombocytopenia due to 2.1.1 The bone marrow hypocellularity with increased in all forms of megakaryocytes but the vacuolated and disintegrated ones. 2.1.2 Destruction by the liver and spleen. 2.1.3 Immune-mediated injury as demonstration of dengue antibody complexes on the platelet surface. 2.1.4 The in vitro spontaneous aggregation to vascular endothelial cell pre-infected by dengue virus inducing platelet aggregation, causing lysis and platelet destruction. 2.2 Dysfunction shown by 2.2.1 Increased release of betathromboglobulin (BTG), PF4 and PGI2. 2.2.2 In vitro hypoaggregation stimulated by ADP and defect in ADP-releasing ability. 3. Coagulopathy including: 3.1 Prothrombin complex deficiency due to liver damage. 3.2 Consumptive coagulopathy due to the activation by mononuclear phagocytes, PF3 released from platelet aggregation. DIC is seen in prolonged shock cases of DSS.

Dengue↗

Immunogenicity and efficacy of a recombinant DNA hepatitis B vaccine, GenHevac B Pasteur in high risk neonates, school children and healthy adults.

The immunogenicity and the protective efficacy of a recombinant DNA hepatitis B vaccine, GenHevac B Pasteur with or without passive immunization with hepatitis B immunoglobulin (HBIG) in high risk neonates born from HBsAg and HBeAg positive mothers was evaluated. Twenty-six neonates (group A) received HBIG 100 IU intramuscularly at birth plus GenHevac B Pasteur 20 micrograms at birth, 1, 2 and 12 months of age while another 23 neonates (group B) received only GenHevac B Pasteur vaccine. Forty high risk newborns who received no immunization served as control group. It was found that at months 4, 12, 13 and 24 the seroconversion rate in both group A and B were very high in the range of 95-100% with the GMT ranging from 10-160,000 mlU/ml. In the control group of infants, 85% had HBsAg positive at one year of age but it was only 3.8% and 8.7% in vaccinated groups A and B, respectively. The protective efficacy in neonates group A and B were 95.5% and 89.8% at one year, respectively, with no statistically significant difference. In 46 normal school children (group C) and 48 healthy adults (group D) who received the same dose of GenHevac B Pasteur the seroconversion rates at month 4 after receiving 3 doses of vaccination were 97.8% and 83.3% in group C and group D, respectively. At month 12, the seroconversion rate in group C rose to 100% and was significantly higher than the 89.6% of group D.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

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↗

Long term efficacy of hepatitis B immunoprophylaxis in neonates at risk: using different vaccine and schedule.

Passive and active immunization for the prevention of hepatitis B virus (HBV) transmission in neonates born to HBeAg positive carrier mothers was studied using different kinds and dosages of combined hepatitis B immunoglobulin (HBIG) and hepatitis B vaccine. The long term efficacy of these various immunoprophylaxis programmes was evaluated up to 3 years of age. Eight groups of neonates, 20 in each group, received HBIG either the usual dose of 100 IU intramuscularly or intravenously or increased dose to 200 IU, combined with different kinds of hepatitis B vaccine either in full dose or half dose given in different schedules of 0, 1, 2 or 0, 1, 6 months, in some groups also received a booster dose at 12 months. After follow-up for 3 years, there were no statistical significant differences of the results between these 8 different immunoprophylaxis programmes, either in the rate of seroconversion or the protective efficacy as well as the antibody response (anti-HBs titer). The seroconversion rates after 3 years of age in all 8 groups were in the range of 63.6 to 92.9 per cent. The protective efficacy rates at 3 years of age were in the range of 69.7 to 100 per cent.(ABSTRACT TRUNCATED AT 250 WORDS)

Carrier State↗

Immunogenicity and protective efficacy of low dose recombinant DNA hepatitis B vaccine in normal and high-risk neonates.

A low dose of recombinant DNA hepatitis B vaccine (HB-VAX II, MSD) was tested for efficacy in the prevention of perinatal hepatitis B virus (HBV) transmission in normal and high-risk neonates born from HBsAg carrier mothers. A dose of 2.5 micrograms recombinant vaccine was injected intramuscularly at 0, 1, 2 and 12 months of age to 30 newborns from HBsAg negative mother (group I), 30 from HBeAg negative/HBsAg carrier mother (group II) and 30 from HBeAg positive/HBsAg carrier mother (group III). The incidence of persistent HBsAg carrier infants at 13 months of age was 0, 0, and 30.4 percent in groups I, II and III, respectively. The protective efficacy in high risk infants in group III was 65.7 percent. The seroconversion at month 4, after the third dose of vaccination was 96.3, 95.7 and 100 percent in group I, group II and group III, respectively. After a booster dose of vaccination at 12 months of age, the seroconversion rose to 100 percent at month 13 in all three groups. The geometric mean titer (GMT) of anti-HBs antibody at 13 months of age were 2,092, 1,657 and 1,938 mIU/ml in group I, group II and group III, respectively. It is concluded that the low dose (2.5 micrograms) recombinant hepatitis B vaccine using alone is effective in prevention of perinatal HBV transmission in low risk infants (groups I and II), but it is less effective in high risk infants (group III).(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗

Subcutaneous mucormycosis caused by Saksenaea vasiformis in a thalassaemic child: first case report in Thailand.

A first case of subcutaneous infection caused by Saksenaea vasiformis in an 11-year-old Thai thalassaemic boy was described. The specific diagnosis of infection was attained from microscopic demonstration of the causal agent as well as the isolation of the fungus. The patient was successfully treated by debridement of the lesion and parenteral amphotericin B. The predisposing factors, source of infection and regimen for treatment are discussed.

Child↗

Sinus histiocytosis with massive lymphadenopathy: the first three cases reported in Thailand.

Three cases of sinus histiocytosis with massive lymphadenopathy are reported in Thai children and is probably a first report in Thailand. They were clinically characterized by bilateral massive cervical lymphadenopathy. Other lymph node groups were also involved but no extranodal manifestations could be detected. Leukocytosis with neutrophilia, hypergammaglobulinemia and polyclonal gammopathy were common features. The characteristic histopathologic findings in the involved lymph nodes included pericapsular fibrosis, markedly dilatation of subcapsular and medullary sinuses which were filled with numerous histiocytes showing active phagocytosis of lymphocytes and lymphoplasmacytoid proliferation in paracortical strands and medullary cord. The disease characteristically has a benign protracted clinical course, and does not respond to either irradiation or chemotherapy. The etiology and pathogenesis of this disorder are unknown. The possible pathologic mechanisms include an abnormal response to a specific infectious process and an immune deficiency status.

Child↗

Hormonal and growth status in long term survivors of acute lymphoblastic leukemia (ALL) in children.

Nineteen children and adolescents in long-term complete remission from acute lymphoblastic leukemia (ALL) were studied for hormonal and growth status after cessation of therapy. Cranial irradiation of 600-2,400 cGy was given for C.N.S. prophylaxis in 18 out of 19 patients, and additional irradiation of 2,000 cGy was given to both testes of a prepubertal boy because of testicular infiltration. The time ranges after cranial irradiation and cessation of therapy at the time of study were 61-137 months and 5-127 months respectively. Thyroid hormone, cortisol and peak cortisol response after ACTH stimulation were normal in every tested children. Basal serum gonadotropin and sex steroid values were appropriate in the majority of patients. A child who received testicular irradiation, had elevated levels of gonadotropins. Glucagon stimulation test (GST) and/or L-Dopa propranolol test (DP test) were used to study growth hormone (GH) response. None had peak GH value less than 7 ng/ml. Ten patients had peak GH values of over 15 ng/ml. Nine female patients had normal puberty and regular menstruation. Eight out of ten male children also had normal puberty. All except two male patients had normal linear growth within 2 standard deviations of the mean. The mean attained final height of 11 children was not significantly different when compared to the mean predicted heights obtained from Bayley-Pinneau and Tanner methods. Excessive weight gain during and after cessation of chemotherapy was observed in the majority of children. Continuing long-term review of these children is essential.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

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↗

Molecular basis of beta-thalassemia in Thailand: analysis of beta-thalassemia mutations using the polymerase chain reaction.

beta-Thalassemia mutations in 71 chromosomes of Thai patients from the northeast, the middle and the south of the country were investigated using dot blot hybridization of PCR (polymerase chain reaction)-amplified DNA with allele-specific oligonucleotide probes. Eight different known molecular defects were detected, at different frequencies. There was an amber mutation in codon 17, a C-T transversion at position 654 of IVS-2, a frameshift mutation between codons 71 and 72, an A-G transition at nucleotide -28 within the TATA box (known as Chinese mutations), a G-T transversion at position 1 of IVS-1 (an Indian mutation), a 4 bp deletion in codons 41/42 and a G-C transversion at position 5 of IVS-1 (described as both Chinese and Indian mutations) and a Thai original mutation, an ochre mutation in codon 35. Analysis of the three unknown alleles by DNA sequencing of the cloned DNA fragment amplified by PCR revealed an A-G substitution at the second position of the codon for amino acid 19 (AAC-AGC). The analytic approach used in the present study and the characteristic distribution of mutations in each region of Thailand will prove useful for setting up a prenatal diagnosis program.

Alleles↗

Hepatitis B immunization in high risk neonates born from HBsAg positive mothers: comparison between plasma derived and recombinant DNA vaccine.

A half dose recombinant hepatitis B vaccine (HBVax II, MSD, 5 micrograms) was investigated for efficacy in the prevention of perinatal hepatitis B virus (HBV) transmission in high risk neonates born from e-antigen positive HBsAg carrier mothers as compared to the half-standard dose regimen of plasma derived hepatitis B vaccine (HBVax, MSD, 10 micrograms). Forty infants born to carrier mothers were given hepatitis B immune globulin (HBIG) 100 IU intramuscularly immediately after birth, combined with either the recombinant or plasma derived hepatitis B vaccine. The infants were randomly divided into two groups of 20 infants each. The plasma derived vaccine (10 micrograms) was given to group I, while infants in group II received the recombinant vaccine (5 micrograms) at birth, 1 and 6 months of age. There were no statistically significant differences in the efficacy and the seroconversion rate of these two combined prophylaxis regimens. The protective efficacy rate of both kinds of HBV vaccine was found to be 94.6 and 89.2 percent in group I and group II respectively. At twelve months of age, the anti-HBs seroconversion rates were 95.0 percent in group I and 84.2 percent in group II. However, the geometric mean titres in group I (179.55 mIU/ml) was significantly higher than those in group II (42.2 mIU/ml) but the anti-HBs titre was still above protective level (10 mIU/ml) in most of the infants.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗

Studies on the pathogenesis of aplastic anemia in Thailand: evidence of immune-mediated mechanism.

The pathogenesis of aplastic anemia in Thailand was studied by using in vitro progenitor cells culture. In 37 patients who had active disease, the numbers of colonies derived from erythroid and granulocyte-macrophage progenitor cells (BFU-E and CFU-GM) were markedly decreased both in the blood and bone marrow as compared to normal controls. Co-culture of patients' cells with normal blood cells was performed in order to verify an immunologically mediated mechanism. In 8 of 26 patients, there were very low numbers of colonies both BFU-E and CFU-GM in the blood and bone marrow with significant suppression of colony formation in co-culture. Suppressor cells may have caused the aplasia in these patients. The rest had low colony formation and no suppression in co-culture. These patients may have absent or defective stem cells. None had normal colony formation. Therefore, aplastic anemia in Thailand may result mostly from defects involving the stem cells. Only some patients had cell mediated suppression of hematopoiesis as detected by co-culture.

Adolescent↗

Hepatitis B immunization in high risk neonates born from HBsAg and HBeAg positive mothers: comparison of standard and low dose regimens.

A reduced dose of plasma derived hepatitis B vaccine (Hevac B) was tested for efficacy in the prevention of perinatal hepatitis B virus (HBV) transmission in high risk neonates born from e-antigen positive HBsAg carrier mothers. Forty newborn infants born of these mothers were given hepatitis B immune globulin (HBIG) 100 IU intramuscularly immediately after birth, combined with either standard or reduced doses of HBV vaccine. The infants were divided into two groups of 20 infants each. The standard dose of HBV vaccine (5 micrograms) was given to group I, while infants in group II received reduced dose (2 micrograms) at birth and at 1, 2 and 12 months of age. There was no statistically significant difference in the efficacy and antibody responses of these two combined prophylaxis regimens. The protective efficacy rate of HBV vaccine was found to be 94.0 and 93.2 percent in group I and group II, respectively. At twelve months of age, the anti-HBs seroconversion rates were 80.0 percent in group I and 86.7 percent in group II, with geometric mean titres of 84.57 mlU/ml and 78.56 mlU/ml, in group I and group II, respectively. One month after a booster at one year of age, anti-HBs could be detected in 86.7 percent of the infants in both groups. The geometric mean titres were 429.04 and 664.81 mlU/ml, in group I and group II, respectively. Anti-PreS2 antibody was detected in high titre as early as 4 months after the first dose of HBV vaccine, with a geometric mean titre of 116.30 mlU/ml and 107.97 mlU/ml, in group I and group II, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Carrier State↗

Natural killer cells in dengue hemorrhagic fever/dengue shock syndrome.

Natural killer (NK) cell activity against K-562 target cells and HNK-1+ cell levels were serially determined in peripheral blood of 62 Thai children with dengue hemorrhagic fever/dengue shock syndrome aged 4-12 years and 59 age-matched normal controls. The studies were performed on febrile stage, 1st and 2nd day of subsidence of fever (shock stage), 3rd and 4th day of subsidence of fever (early convalescent stage) and once again on the late convalescent stage (approximately 14-18 days after subsidence of fever). The study revealed that during the course of disease the NK cell activity was not changed significantly from the normal controls. In contrast, the levels of HNK-1+ cells, which exhibited almost all NK and killer cell functional activities, were significantly decreased in the febrile and the shock stages and were normal in the early and late convalescent stages. The NK cell activity, on the per-cell basis, was significantly increased in the early disease stage when compared to that of the later period of the disease and of the normal controls. The study also revealed that patients with grade III of disease severity exhibited significantly more NK cell functional activities per cell than grade II on febrile stage and the first day of shock. These results suggest that natural killer cells were active in defense against dengue viral infection and might play some role in the pathogenesis of dengue hemorrhagic fever/dengue shock syndrome. Their functions might also determine the severity of the disease.

Child↗