Suphan Soogarun

Anti-oxidant activity of holo- and apo-c-phycocyanin and their protective effects on human erythrocytes.

This study was conducted to investigate the anti-oxidant activity of the recombinant apo-c-phycocyanin (c-PC) β-subunit compared to native c-PC purified from Spirulina sp. The gene encoding the β-subunit of c-PC was successfully cloned and expressed in Escherichia coli. The anti-oxidant capacities of recombinant apo-c-PC(β) and native c-PC were evaluated by measuring their Trolox equivalent antioxidant capacities and examining their protective effects on erythrocytes from normal and homozygous haemoglobin E individuals against peroxyl radicals and hydrogen peroxide. The results demonstrated that the anti-oxidant capacities are native c-PC≫Trolox>recombinant apo-c-PC(β). Both anti-oxidant proteins can potentially protect erythrocytes from oxidative damage. Expression of c-PC in bacteria reduces the cost and time for protein production, and the recombinant protein could be further developed to obtain a more efficient protein for therapeutic purposes.

Multilayer film assembled from charged derivatives of chitosan: physical characteristics and biological responses.

Polyelectrolyte multilayer films were successfully assembled from each of the three charged derivatives of chitosan; N-[(2-hydroxyl-3-trimethylammonium)propyl]chitosan chloride (HTACC), N-succinyl chitosan (SCC) and N-sulfofurfuryl chitosan (SFC), paired with one of the two oppositely charged polyelectrolytes, poly(acrylic acid) (PAA) and poly(allylamine hydrochloride) (PAH) on surface-treated poly(ethylene terephthalate) (treated PET) substrates by alternate layer-by-layer adsorption. Surface coverage and wettability of the multilayer films were determined by AFM and water contact angle measurements, respectively. Analysis by quartz crystal balance with dissipation (QCM-D) has suggested that all multilayer films are relatively rigid and have a high water content associated within their structures, accounting for up to 85-90% (w/w) for films having 7-10 layers. In vitro cytocompatibility tests for the fibroblast-like L929 cell line revealed a slight dependency for cell adhesion and proliferation on the outermost layer. The multilayer film containing HTACC exhibited moderate antibacterial activity against E. coli and S. aureus. Bearing negative charges, the multilayer films terminating with SFC and having at least 10 layers were capable of suppressing the adsorption of plasma proteins and platelet adhesion at a comparable level to the multilayer film assembled from heparin, a well-known antithrombogenic polymer.

Effect of smoking on platelet count and platelet parameters: An observation

Arterial thrombosis occurs with increased frequency in cigarette smokers. It is believed that disturbance of platelet function, especially aggregation, is the essential mechanism responsible for this pathology. However, the effect of smoking on the quantity of platelets might be another contributing factor. The effect of smoking on platelet count is still controversial. We performed a cross sectional study to compare the platelet count and platelet parameters in Thai police who are smokers and non-smokers. A total of 30 Thai police in Bangkok were included in this study. Of the 30 police, there are 5 non-smokers and 25 smokers. The platelet counts and platelet parameters of the subjects were not significantly different between smokers and non-smokers.

Effects of Tai Chi Training on Antioxidant Capacity in Pre- and Postmenopausal Women

The risk of oxidative stress-related metabolic diseases increases with menopause and physical inactivity. We hypothesized that an 8-week Tai Chi (TC) training program (2 sessions in class; 2 sessions at home; 1-1:15/session) would improve antioxidant capacity and reduce cardiovascular risks in both pre- (n = 8) and postmenopausal (n = 7) sedentary women. Selected measures of physical fitness and blood parameters were analyzed before and after the program. Besides the well-known effects of TC on balance, flexibility, and maximum leg extensor strength, TC (1) increased erythrocyte glutathione peroxidase activity—an aerobic training-responsive antioxidant enzyme—and plasma total antioxidant status and (2) decreased plasma total homocysteine, a cardiovascular risk marker. In addition to being a low-velocity, low-impact, and relatively safe, TC is a suitable physical activity design for pre- and postmenopausal women to increase antioxidant defenses. Investigating breathing effects during TC movements would be an interesting area for further research in diseases prevention.

Red cell and platelet‐derived microparticles are increased in G6PD‐deficient subjects

In response to oxidative stress and during apoptosis, cells often shed microparticles (MPs), submicron elements carrying phosphatidylserine and protein antigens. Glucose‐6‐phosphate dehydrogenase (G6PD)‐deficient cells are extremely sensitive to oxidative damage that may lead to the formation of MPs. To determine whether G6PD deficiency alters membrane phospholipid asymmetry and increases MPs production, we determined the concentrations and cellular origins of MPs in G6PD‐deficient individuals using flow cytometry. G6PD‐deficient individuals showed an increase in circulating MPs concentrations as compared with G6PD‐normal individuals [1051/μL (865–2532/μL) vs. 258/μL (235–575/μL), P < 0.01]. MPs concentrations were significantly increased with the severity of G6PD deficiency. Median MPs concentrations from individuals with severe G6PD deficiency, and individuals with moderate G6PD deficiency were 2567/μL (1216–2532/μL) and 984/μL (685–2107/μL), respectively (P < 0.01). Importantly, G6PD enzymatic activity was significantly correlated with MPs concentrations with r2 = 0.731. MPs found in G6PD deficiency individuals were largely derived from red blood cells (RBCs) (45%) and platelets (30%). Additionally, Atomic Force Microscopy was used to study the morphology and measures the diameter of MPs found in G6PD‐deficient individuals. The mean (SD) width and height of RMPs were 0. 41 (0.18) and 2.04 (0.14) μm, respectively. Together, these results indicate that MP concentration is significantly correlated with G6PD enzymatic activity and is increased in G6PD‐deficient as compared with G6PD‐normal individuals. Our data also provide an evidence for an alteration in cell membrane associated with a decreased in G6PD activity. However, the significance of MPs in G6PD deficiency needs further clarification.

A Correlative Study on Red Blood Cell Parameters and Urine Trans, Trans-Muconic Acid in Subjects with Occupational Benzene Exposure

Benzene is of particular concern because of recent research indicating that benzene exposure can result in toxicity. The hematotoxic effect of benzene is mentioned. However, there is little knowledge about the correlation between the biomarker of benzene exposure and changes in red blood cell parameters. Here, the correlation between the urine trans, trans-muconic acid (ttMA) level and red blood cell parameters were studied in 30 Thai subjects at risk. The regression analysis shows no significant correlation between urine ttMA and any studied red cell parameters (Hb, MCV or MCH). Based on our hematologic data, we proposed that only investigation for the urine ttMA might be not sufficient in detection of alteration in red blood cell parameters in the exposed population. Combinations between biomarker and hematological test are recommended.

A Trend of Platelet Indices in Patients with Green Pit Viper Toxin

The green pit viper (Trimeresurus albolabris and Trimeresurus macrops) is a common venomous snake in Thailand. The green pit viper venom has major effects on the hematologic system. The venom is found to have a thrombin-like effect in vitro but cause a defibrination syndrome in vivo. Unlike other pit viper snakes (such as Malayan pit viper and Russels pit viper), the venomous effect on red blood cells is rarely mentioned. Clinical features of venomous snake bites vary from asymptomatic to fatal bleeding. In this study, an attempt was made to discern hematologic parameters in green pit viper envenomation and to characterize the changes in blood cells. The study included data from 40 patients who were hospitalized at the King Chulalongkorn Memorial Hospital during 1995 to 1999 and 40 normal, healthy subjects as control. Concerning platelet determination, significantly decreased (p < 0.05) total platelet count and mean platelet volume (MPV) were demonstrated in envenomous blood. The changes in blood cells may be partly due to the effect of green pit viper toxin on the platelet morphology. However, the explanation of this phenomenon requires further investigation for the specific pathophysiology. The components of green pit viper venom that have these hematologic effects in humans are interesting and should be further identified.

Urine phenol and myeloperoxidase index: an observation in benzene exposed subjects.

Benzene is a colorless poisonous liquid with a sweet odor. At present, it is documented as a known inducer of leukemia. Potential metabolic mechanisms underlying the hemopoietic toxicity of benzene include bioactivation of phenolic metabolites of benzene by myeloperoxidases in bone marrow, which results in hydroquinolone, a major leukemogen. There is no previous correlative study between the level of phenol, urine benzene metabolite, and the myeloperoxidase index (MPXI). Here, the correlation between the urine phenol and MPXI were studied in 24 Thai subjects occupationally exposed to benzene. Of interest, the regression analysis show no significant correlation between urine phenol level and MPXI (r = -0.05, P = 0.81).

White blood cell sister chromatid exchange among a sample of thai subjects exposed to toluene, an observation

There is a particular concern with toluene because some research has indicated that toluene exposure could result in chronic toxicity including mutagenesis and carcinogenesis. This study aimed to determine the rate of sister chromatid exchanges (SCE), a marker for genotoxicity, and its correlation to the classical urine biomarker for toluene exposure, urine hippuric acid, among a sample of Thai exposed subjects. A total of 26 police (all males) were included in this study. The average (mean ± SD) urine hippuric acid level in these police was 0.8 ± 0.4 mg/g creatinine. The average (mean ± SD) SCE level in these police was 4.5 ± 1.0/cell. The average SCE among the police with high urine hippuric acid levels was non‐significantly higher than the average SCE level of those without (P = 0.41). This implies that the cytogenetic response to toluene was not different between the subjects with and without high toluene exposure. High exposure to toluene seems not to be related to high SCE.

The Urine Trans, Trans Muconic Acid Biomarker and Platelet Count in a Sample of Subjects with Benzene Exposure

Benzene exposure is of particular concern because of ongoing exposure to thousands of workers. Prolonged exposure can cause chronic toxicity, especially hematologic disorders. The effects of benzene on red blood cells and white blood cells have been clearly proposed; however, the effect of benzene on platelets has not been studied. The correlation between the level of trans, trans muconic acid (ttMA), a urine metabolite of benzene, and the platelet count of subjects occupationally exposed to benzene was studied. Thirty volunteers who were occupationally exposed to benzene were investigated for both urine ttMA levels and platelet parameters. According to the regression analysis, no significant correlation existed between urine ttMA level and any platelet parameters (p > 0.05). However, although there is no statistical significance, the platelet count and PCT decreased while the urine ttMA increased. In addition, using the upper normal limit ttMA level as the cutoff level, the statistically significant lower platelet count and PCT was observed in the subjects with urine ttMA higher than upper normal limit. This report is the first world report on this topic and the results from this study can provide good basic data for further understanding the effect of benzene exposure on the platelet.