Lymphocyte subpopulations in malaria infected individuals living in an endemic area.

Development of partial immunity in people living in malaria endemic area is complex. For better understanding, the lymphocyte subpopulations from infected patients were evaluated by flow cytometer before any antimalarial treatment. In P. vivax infection, the frequency of T-helper type 1 (Th1) was decreased significantly (p = 0.042). In contrast, the number of T- helper type 2 (Th2) was increased significantly (p = 0.001). These trends have also been observed in P. faciparum infection. The Th2 predominant response to the natural malaria infection is likely due to persistent stimulation by Plasmodium species. In P. falciparum infection, CD8+ cytotoxic lymphocytes were significantly reduced (p = 0.007). However, such changes were not found in P. vivax infection. This might suggest that CD8+ cell responses to different Plasmodium spp in a different way. Both Th2 activation and CD8+ cell suppression may reflect less protective effects and chronic malaria infection could be established.

Evaluation of the effect of steviol on chromosomal damage using micronucleus test in three laboratory animal species.

The chromosomal damage activity of steviol, a product of enzymatic alteration of stevioside, a natural non-caloric sweetener was reevaluated by using a bone marrow micronucleus test in both male and female hamsters, rats and mice. The micronucleus test is used widely as a rapid and efficient alternative in chromosome analysis for detecting in vivo cytogenetic damage. Steviol at the dose of 4 g/kg body weight for hamsters and 8 g/kg body weight for rats and mice showed no effect on the frequencies of micronucleus formation in bone marrow erythrocytes of both male and female hamsters, rats and mice. Moreover, there was also no apparent change in the PCEs:NCEs (polychromatic erythrocytes:normochromatic erythrocytes) ratio of the male animals of all three treated species at 24, 30, 48 and 72 hour intervals. However, steviol at the given dose can cause significant reduction of PCEs to NCEs ratio of the female hamsters at 72 hours and female rats and mice at 48 and 72 hours after receiving steviol orally. From these results, it could be proposed that steviol at the given dose to the treated animals produced adverse metabolites and these metabolites could reach the bone marrow, the target organ for micronucleus test. These metabolites also exhibited a slightly cytotoxic effect but not clastogenic effect to the bone marrow erythrocytes.

The effects of cigarette smoking on peripheral blood leukocytes and lymphocyte subpopulations: an urban population-based study in Thailand.

Preliminary studies for peripheral blood leukocytes and lymphocyte subsets were done in smokers and non-smokers. There were 20 smokers (smoked more than 10 cigarettes per day) for more than a year and 20 non-smokers (smoked less than 20 cigarettes/20 years). Ages of smokers and non-smokers were respectively 21-57, and 18-55 years. Cigarette smoking was associated with a statistically significant increase in the number of neutrophils, activated lymphocytes, CD25 and CD19; but a statistical decrease in the percentage of CD7 and CD3. (P < 0.05)

Lack of mutagenicity of stevioside and steviol in Salmonella typhimurium TA 98 and TA 100.

Stevioside, a sweet-tasting diterpene glycoside derived from Stevia rebaudiana, and steviol, a product from enzymatic hydrolysis of stevioside, were tested for mutagenic activity by the in vitro Ames test, a preincubation method, using Salmonella typhimurium TA 98 and TA 100 as the tester strains, either in the presence or absence of metabolic activating system derived from the sodium phenobarbital and 5,6-benzoflavone pretreated liver S9 fractions from various animal species including rat, mouse, hamster and guinea pig. Stevioside and steviol at the concentrations up to 50 mg and 2 mg per plate, respectively showed no mutagenic effect on both tester strains either in the presence or absence of metabolic activating system. However, at the high concentration both stevioside and steviol showed some toxic effects on both tester strains. The toxic effect was decreased in the presence of the metabolic activating system.

The effect of standardized ginseng extract on peripheral blood leukocytes and lymphocyte subsets: a preliminary study in young health adults.

The present study was undertaken in twenty young, healthy Thai males to investigate the effects of prolonged administration of standardized ginseng extract on peripheral blood leukocytes and lymphocyte subsets. The subjects were divided into two equal groups as ginseng and placebo groups. The first group received two capsules daily of standardized ginseng extract 150 mg per capsule for 8 weeks. The second group received placebo and served as control. Circulatory levels of total and differential leukocyte counts and percentage of lymphocyte subsets were determined prior to and at the 4th and 8th week of the experimental period. There were no significant differences in the total and differential leukocyte counts as well as the lymphocyte subpopulations: CD3 (T cells), CD 19 (B cells), CD4 (T-helper cells), CD8 (T-suppression cells), CD4/CD8 ratio, and CD25 (Interleukin-2-receptor cells) between the two subject groups throughout the experimental period. We concluded that oral administration of standardized ginseng extract, 300 mg/day for 8 weeks caused no significant changes in peripheral blood leukocytes and lymphocyte subsets in young, healthy Thai males.

Cytochemical and immunological phenotying of acute nonlymphoblastic leukemia in Thai patients.

Using morphology and cytochemical reaction, we could subclassify-according to FAB classification, 51 of our 56 cases of acute nonlymphoblastic leukemia (ANLL) as M1-M5. Five cases were undifferentiated. Using the immunophenotypic method, we could subclassify 51 of these patients as M1-M4. In addition, 3 cases of undifferentiated leukemia by the prior method were each classified as M1, M3, and myelo-megakaryoblastic leukemia. Correlation of ANLL subtype classification according to each method was not good. However, combination of both methods, using immunophenotypic analysis as a supplement would better subclassify the disease. One of the remaining 2 cases of undifferentiated leukemia was also shown to be myelo-megakaryoblastic leukemia by a positive platelet peroxidase reaction by ultrastructural cytochemistry. Thus, combination of these 3 methods could diagnose and subclassify 55 of the 56 cases (98%) of our ANLL patients.

Cell analysis of bronchoalveolar lavage.

Ninety bronchoalveolar lavage (BAL) of Thai cancerous cases (28), tuberculous cases (24); non-tuberculous cases (17) and miscellaneous diseases cases (13) was performed for total and differential BAL cell count. This technique could be initially used as a guideline for suggestive diagnosis in some suspicious cases particularly cancer from tuberculous BAL. The combination in the ratio of macrophages to dusty and foamy macrophages below 1.25 and total BAL cell count lower than 0.85 x 10(3)/mm3 could suggest a diagnostic indication of cancerous BAL rather than tuberculous BAL or other diseases. Tuberculous BAL revealed a high percentage of macrophages, low level of dusty and foamy macrophages. Non-tuberculous BAL could be distinguished from other diseases by the higher percentage of neutrophil over 55% and lower percentage in every type of macrophages, whereas, a high level in every type of macrophages was found in miscellaneous BAL.

Effect of zinc supplementation on zinc status, copper status and cellular immunity in elderly patients with diabetes mellitus.

This preliminary study was to investigate the effects of zinc supplementation on Zn status, Cu status, serum macrominerals and lymphocyte subsets in elderly diabetic patients. The results of Zn supplementation can correct plasma Zn levels to normal values. However, this treatment did not affect the cellular Zn, copper status and serum macrominerals. Enhancement of the percentage of CD4 cells was observed after Zn therapy but had no effect on the percentage of CD8 cells and CD4/CD8 ratios. Our finding implicated that zinc supplementation might be useful to enhance the immune status in these patients.

Fetal red cell staining: method evaluation.

Acid elution methods have been extensively used for the identification of fetal red cells in pregnant women with fetomaternal hemorrhage. A number of methods have been described: Kleihauer-Betke, Boehringer Mannheim, Fetaldex, Nierhaus-Betke modification and Sanguansermsri amido black B. A comparative evaluation of these methods was performed in this study. The technique of Sanguansermsri using amido black B was found to be more advantageous than the others in terms of simplicity, accuracy, precision and time taken.

Cytochemical reactions of homozygous beta-thalassemic spleens.

Splenic cells from 10 homozygous beta-thalassemic patients were stained using cytochemical reactions: non specific esterase and acid phosphatase. Spleens from nonthalassemic subjects: a normal case who underwent gastric surgery and 5 idiopathic thrombocytopenic purpura, were also studied to serve as the control. In thalassemic spleens, no positive dot cell was shown in periarteriolar lymphocyte sheaths (PALS) when they were stained with both nonspecific esterase and acid phosphatase. In contrast, dot positive reaction was demonstrated in 92 per cent of cells from a normal spleen. These cells were presumably T lymphocytes. There were two possibilities to explain our study 1) the absence of T lymphocytes in the PALS of white pulps in homozygous thalassemia may have an impact on the immune system related to infection complication in thalassemia 2) T lymphocytes in the thalassemic spleen may be present but they do not give a positive ANAE dot reaction.

Immunophenotype and cytochemical reactions of acute lymphoblastic leukemia in Thai children.

The immunophenotypes of acute lymphoblastic leukemia (ALL) in 28 Thai children were studied by the APAAP technique using a panel of eight specific monoclonal antibodies: HLA-DR, CD 19, CALLA (CD 10), IgM, CD 7, CD 3, CD 4, and CD 8. Sixty-eight, 18, 3.5, 3.5, and 7 per cent were respectively shown to be common, null, pre-B, B, and mature thymocyte T subtypes. Cytochemical reactions (beta-glucuronidase, alpha naphthyl acetate esterase, and acid phosphatase) in this study could identify null, common, and T ALLs with confidence, and could be used in the process of ALL subtyping to reduce cost.

Clinical features of acute lymphoblastic leukemia subclasses in 28 Thai children--a preliminary study.

Twenty-eight Thai children with newly diagnosed acute lymphoblastic leukemia were evaluated for pretreatment characteristic, including immunophenotype of lymphoblast, outcome of treatment, and the correlation among them. By APAAP technique using a panel of eight monoclonal antibodies (HLA-DR, CD 19, CALLA (CD 10), IgM, CD 7, CD 3, CD 4, and CD 8), five subclasses were identified: 67.9, 17.9, 7.1, 3.6, and 3.6 per cent were respectively shown to be common-, null-, mature thymocyte T-, pre B-, and B-ALLs. Clinical features in each subclass conformed to previous reports. All of the 27 evaluable patients attained initial complete remission, but subsequent relapses were noted in 7 patients (25.9%). Three of the 19 cases in the common ALL group relapsed at 6-12 months, whereas, 4 of the 8 cases in the non-common ALL group relapsed at 2-15 months. Probability of relapse at 12 months in the common and non-common ALL groups were 19 and 49 per cent respectively. Disease-free survival from time of remission was shorter in the non-common ALL group. Multivariate analysis of the 6 factors predicting disease-free survival showed that the only strong factor was the immunophenotype of lymphoblast.

Silicosis in ceramic-industry workers with particular reference to the diagnostic value of bronchoalveolar lavage.

We could identify, via bronchoalveolar lavage, crystals in the lavage fluid and in the alveolar macrophages. Thus, BAL could be another method for diagnosing silicosis patients.

Blood cell production and hemostatic mechanism in Thai vegetarians.

The activity of hemostatic mechanism and blood cell production of 50 Thai vegetarians and 30 nonvegetarians were compared. The hemostatic mechanism of both vegetarians and nonvegetarians showed no significant difference, whereas, a significant decrease in hemoglobin, hematocrit and red blood cell count with significant increase in hypersegmented neutrophils were found in vegetarians who had taken vegetarian diets for over 4 years.

Increased ovalocytic red cells and their low parasitemia in malaria infected subjects.

Ovalocytic red blood cells were significantly increased in the peripheral blood films of patients infected with P. falciparum (mean +/- S.D. = 6.3 +/- 8.4%) and P. vivax (8.3 +/- 14.0%), whereas, there was only 0.6 +/- 0.4 per cent ovalocytes in normal individuals. Per cent parasitemia of ovalocytes counted at least 100 ovalocytes of the blood films of malaria infected individuals was significantly reduced when compared with that of discocytes which revealed at least 100 discocytes in the same blood smears. Relative increase in ovalocyte and their low parasitemia might be the response of malaria infected individuals to cope with malaria multiplication in their circulation.

Cytochemical evaluation of neutrophil components in beta thalassemia hemoglobin E.

The mean +/- S.D. of LAP score in neutrophil of the normal control, non splenectomised patients and splenectomised patients were 116 +/- 78, 94 +/- 48 and 37 +/- 23 Kaplow units, respectively. The significant reduction in the leukocyte alkaline phosphatase level (P less than 0.05) was found in beta thalassemia/HbE patients. The degree of reduction was greater in the splenectomised patients (P less than 0.05). The decreased LAP levels in PMN was persistent. This was in contrast to the LAP in PMN of other patients where as LAP returned to normal after splenectomy. The relevance to the increased susceptibility to infection and low LAP in beta thalassemia/HbE should be further investigated.