The effect of green pit viper (Trimeresurus albolabris) venom on platelet morphology by electron microscopy.

The incidence of venomous snake bites increases every year in Thailand, especially due to green pit viper. After the bite, there is bleeding due to thrombin-like property of the venom. The mean platelet volume has been reported to be decreased in those who have been bitten by this snake. In this study we investigate the effect of green pit viper venom (Trimeresurus albolabris) on platelet volume (MPV), number and morphology of platelets in vitro. The test was carried out by washing platelets in phosphate buffer at pH 7.2 to remove fibrinogen, then the washed platelets were mixed with green pit viper venom. Platelet morphology was examined by scanning electron microscope (SEM).The morphology of platelets was smaller than normal which ranges from 1.1- 1.2 microm. Green pit viper venom can directly effect platelet morphology, decreasing platelet volume.

Detection of Cryptococcus neoformans in bird excreta.

We evaluated 14 samples of bird excreta from pigeons, parrots, open billed storks and crows obtained from thirteen places in Bangkok and nearby areas between April and July 2004. These bird excreta were examined for Cryptococcus neoformans by direct plating method to inspect their ability to grow at 37 degrees C. Capsule production was examined by Indian ink preparation. They were also tested for urease and phenoloxidase enzymes. Cryptococcus neoformans var neoformans was recovered from pigeon excreta in 9.09%. This implies those having impaired immunity may get this fungus from the environment.

Preliminary study of the effect of vitamin E supplementation on the antioxidant status of hemoglobin-E carriers.

The antioxidant status of hemoglobin-E carriers was studied pre- and post-treatment with vitamin E for 3 months. Fourteen hemoglobin-E carriers (age = 21.36 +/- 1.08 years, BMI = 18.32 +/- 1.22 kg/m2) were treated with vitamin E 200 I.U. daily for 3 months. Fasting blood samples were collected and analyzed for erythrocyte superoxide dismutase activity, total antioxidant activity, hemoglobin concentration, hematocrit, MCV, Heinz body formation and osmotic fragility test. The blood parameters before and after vitamin E treatment were compared. The results showed that superoxide dismutase activity in the erythrocytes was significantly decreased, while total antioxidant activity in plasma, and the osmotic fragility of the erythrocytes, was significantly increased after vitamin E supplementation. However, hematocrit, MCV, and Heinz body formation did not change significantly. This demonstrated that vitamin E 200 IU could be used as a lipophilic antioxidant in red blood cells and could help increase the level of antioxidant in hemoglobin-E carriers.

High sister chromatid exchange among a sample of traffic policemen in Bangkok, Thailand.

There are several volatile substances from the traffic, including benzene, toluene, carbon monoxide, lead and formaldehyde. Most of these substances are considered carcinogens. Police are at occupational risk for toxic fume exposure. This study compared sister chromatid exchange (SCE), a marker for genotoxicity, among a sample of Thai traffic policemen in Bangkok with healthy control subjects. Thirty police officers (all male) and 20 controls were included in this study. The average (mean+/-SD) SCE for policemen and controls were 4.40+/-0.93/cell and 0.24+/-0.12/cell, respectively. A significantly higher SCE among the policemen was observed. Concern for and prevention of toxic substance exposure in traffic police officers should be made a national goal.

Feasibility of using papaya skin extract for digestion of swamp eel viscera for harvesting infective stage larva of Gnathostoma spp.

In this study, we reported the feasibility of using papaya skin extract (Carica papaya L.) as an alternative to enzyme pepsin in harvesting Gnathostoma spinigerum third-stage larvae. From experimental digestion, we found that the different numbers of recovered larvae between papaya skin extract and pepsin were not statistically significant (p >0.05). When the derived larvae from pepsin and papaya skin extract digestion were cultivated in BME medium for 7 days, the survival rates were not significantly different either (p >0.05). Thus, papaya skin extract might be another choice for recovering Gnathostoma spinigerum third-stage larvae.

Antioxidant in plasma of hemoglobin-E trait.

A study of antioxidant levels among Thai subjects with a hemoglobin E trait was undertaken. The objective of this study was to determine whether the antioxidant level would be disturbed in the HbE condition. All 185 volunteer subjects, 171 normal healthy subjects and 14 HbE carriers were recruited. For each case, an antioxidant determination was performed using the Trolox equivalent antioxidant capacity (TEAC) method. According to this study, the average antioxidant level in the healthy group was 3.439 +/- 0.220 mM Trolox equivalent, and in HbE trait group was 3.276 +/- 0.209 mM Trolox equivalent. There was a significant decrease of the antioxidant level in the HbE trait group (p = 0.008).

Inhibition of Heinz body induction in an in vitro model and total antioxidant activity of medicinal Thai plants.

Herbs have been used for medicinal purposes for centuries and known to possess antioxidant properties that may help to reduce the risk of chronic diseases, cardiovascular disease, and cancer. We screen aqueous extracts from 20 medicinal plants in Thailand that were believed to possess anti-tumor activity, help immune-stimulating property and maintain blood stasis. The antioxidant activities were investigated in two bioassays. Firstly, we demonstrated inhibition of Heinz bodies induction caused by oxidants under in vitro condition. The percentages of Heinz body inhibition activity in plant extracts from Terminalia citrina, Cassia timoriensis, and Derris elliptica were the highest followed by Anamirta cocculus, and Oroxylum indicum respectively. In addition, we investigated total antioxidant activity in plant extracts by improved ABTS radical cation decolorization assay. The total antioxidant activity of the extract from Terminalia citrina was also the highest activity followed by Ficus pubigera, Derris elliptica, Anamirta cocculus, Caesalpinia sappan, and Oroxylum indicum respectively. Our results suggest medicinal Thai plants as valuable sources of antioxidants, which may have a potential anti-carcinogenic activity.

Cancer risk for Thai traffic police exposed to traffic benzene vapor.

Benzene exposure is of particular concern because recent research indicates that it can result in chronic toxicity, with an elevated risk of carcinogenesis. Exposure to benzene from automobile exhaust can be an important occupational problem for police. The present study was conducted to estimate risk of Thai traffic police developing cancer due to contact with traffic benzene vapor during daily work. According to the data obtained, the estimated predicted cancer incidence for traffic police is 0.05 case per 70-year period, simply translated as 1.8 cancer cases per 100,000 traffic police per year. This is clearly a cause of concern and annual check up and monitoring for benzene exposure among traffic police should be set up as part of a program for primary prevention of occupation -- related cancer.

Urine phenol levels among Thai police, implications for occupational health.

In this study, we study an at-risk occupation, the police. Forty-five urine samples were obtained from 45 Thai police working close to traffic in an urban area, for analysis of urine phenol levels. The average (mean +/- SD) urine phenol level in these police was 16.94 +/- 11.72 mg/g-Cr. Significantly higher urine phenol levels were found among police who had worked for longer durations (p < 0.05).

Pineapple juice for digestion of swamp eel viscera for harvesting infective-stage larva of Gnathostoma spp.

Third-stage larvae were used as antigen in the diagnosis of gnathostomiasis in Western blot analysis. Normally, the larvae were obtained from digestion of eel's liver (Fluta alba) by the enzyme pepsin. We used pineapple juice (Ananus comosus) instead of enzyme pepsin in harvesting Gnathostoma spinigerum third-stage larvae. The difference in recovered larvae numbers, between pineapple juice and pepsin, were not statistically significantly different (p>0.05). The larvae from pepsin and pineapple juice digestion were cultivated on BME for 7 days; the survival rates were not significantly different (p>0.05). Thus, pineapple juice is another enzyme of choice for recovering Gnathostoma spinigerum third-stage larvae.

Report on blood cholinesterase among vegetable growers.

We report our study on serum cholinesterase in vegetable growers, a risk occupation in a rural area of Thailand. In this study, 70 subjects (35 vegetable growers and 35 controls) were studied. The mean blood cholinesterase level in vegetable growers (17.7 +/- 7.0 U/ml) was significantly lower than that of the control group (24.7 +/- 12.4 U/ml) (p=0.01).

Facilities for the disabled in the commercial districts of Bangkok--are they adequate?

Equal rights for the disabled are widely accepted, at least in principle. Basic public facilities for these people are minimum requirements. We performed a cross-sectional descriptive survey of three basic facilities (wheelchair ramps, elevators and modified toilet) in public buildings, of more than 5 floors in the Silom and Siam business areas of Bangkok. Of a total of 62 buildings surveyed, no building had all three facilities. The slope ramps, elevators and modified toilets were found in 26, 49, and 1 buildings respectively. Facilities for the disabled in this area of Bangkok were inadequate. All public buildings should provide appropriate facilities: special legislation may be warranted.

The formol-ether concentration technique for intestinal parasites: comparing 0.1 N sodium hydroxide with normal saline preparations.

The formol-ether method is a widely used technique for stool examination. We performed a comparative study of 0.1 N sodium hydroxide (NaOH) and normal saline preparation for the formol-ether technique in the detection of intestinal parasites. Of 30 parasite-containing stool samples, 22 (73%) were positive by 0.1 N NaOH and 18 (60%) were positive by normal saline. The detection rate of both preparations was not significantly different (p>0.05).

Using reticulocyte indices to identify alpha-thalassemia--a preliminary report.

Thalassemia poses an important public health problem in Thailand. The Ministry of Public Health of Thailand has conducted many programs for the control of thalassemia. These programs are useless if there is no effective, affordable method of screening for carriers. We report on the possibility of using an automated reticulocyte analyzer in order to identify alpha-thalassemia. Thirty-one control subjects and 14 couples, whose offsprings were affected with thalassemia H (7 alpha-thalassemia-1 and 7 alpha-thalassemia-2) were studied. We found that almost all reticulocyte parameters could be used as diagnostic marker of alpha-thalassemia-1 carriers. Unfortunately, alpha-thalassemia-2 had only 5 parameters that were significantly different when compared to normal controls. This is the report to focus attention on the use of reticulocyte parameters in the screening of alpha-thalassemia.

Vaccinating Thai adolescents against hepatitis A: is it cost-effective?

Hepatitis A infection is a common disease in tropical countries, including Thailand. Hepatitis A vaccination of children and adolescents has been recommended by many countries. We performed a cost-benefit analysis in order to determine the best strategy for Thailand. Three strategies were tested: a) no intervention; b) vaccination without screening; c) vaccination after screening. A review of the literature was performed in order to set the path probability of each strategy. The cost of intervention of each strategy was identified; the outcome cost was the total economic loss due to hepatitis A infection as the result of each strategy. Benefit was the final total cost according to each strategy (cost of intervention and economic loss due to possible hepatitis A infection). Surprisingly, the most benefit was gained from a strategy of no intervention. Vaccination after screening was the worst strategy. Our results indicated that hepatitis A vaccination for Thai adolescents was not cost-effective.