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.

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.

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.

Preparation of Gnathostoma protein by ultrafiltration method using Nanosep membrane.

We report our experience with Gnathostoma protein preparation by the ultrafiltration method. Crude antigen was sonicated and ultrafiltrated using the Nanosep 100 K membrane. SDS-PAGE electrophoresis showed protein bands at 43, 41, 24, 22, 21, 19.5 kDa. Use of the ultrafiltration method can provide specific protein (24 kDa), similar to the non-ultrafiltration method, with the other 5 non-specific proteins. Using the non-ultrafiltration method, there were more (20) non-specific protein. The ultrafiltration method can be an alternative method for the preparation of protein, which can provide better results than non-ultrafiltration.

Study of factors influencing intestinal parasitic infections in a rural community in northeastern Thailand.

We performed a survey in a rural village, in Nam Som District, Udon Thani Province, northeastern Thailand, focusing on intestinal parasitic infections and possible related personal factors. From a survey of the 178 villagers, we found the intestinal parasitic infection rate equal to 26.4% (47 cases). Further factor analysis was performed to find whether factors were related to the intestinal parasitic infections among the subjects. Of the total 20 factors analyzed, only three factors showed significant correlations with intestinal parasitic infections. The three factors were average annual income (p = 0.007), having a toilet (p = 0.040) and eating undercooked food (p = 0.010). The factors identified are the common problem described in many studies, the poor sanitation of the villagers. The economic status of the subjects is still an important factor influencing intestinal parasites among this sample of the Thai rural population.

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).

High urine ttMA levels among fishermen from a Thai rural village.

The ongoing industrialization of Thailand, a developing country in Southeast Asia, has put many occupations at high risk of benzene exposure. However, there are few reports about monitoring the biomarkers of benzene exposure among Thais. In this study, we report on high urine trans, trans-muconic acid (ttMA) levels among the fishermen of a rural community. Using high-performance liquid chromatography (HPLC) for urine ttMA determination, 49 subjects (30 fishermen and 19 control subjects) were studied. The mean urine ttMA level in fisherman (0.180 +/- 0.130 mg/g creatinine) was significantly higher than that of the control group (0.015 +/- 0.053 mg/g creatinine) (p < 0.05). We recommend the monitoring of urine ttMA in these workers. The monitoring of the possible benzene contamination of the water and fish is recommended for further study.

High levels of hippuric acid in the urine of Thai press workers.

Toluene is an important toxic volatile agent found in many modern industrial processes. Toluene exposure is of particular concern because of the ongoing exposure of thousands of workers in industrial plants and recent research has indicated that toluene/exposure can result in chronic toxicity. The monitoring and control of toluene exposure among at-risk workers is necessary. Urine hippuric acid determination is a helpful test monitoring groups of at-risk workers. In this study, urine samples were obtained from 20 control subjects and 48 press workers from a factory in Bangkok. Each subject gave a specimen of urine; each specimen was analyzed for hippuric acid level by the Ohmori method. The average urine hippuric acid level in the control group was 0.23 +/- 0.15 mg/gCr (range = 0.05 - 0.58 mg/gCr) while that of the experimental group was 0.37 +/- 0.37 mg/gCr (range = 0.06 - 0.18 mg/gCr). A significant higher urine hippuric acid level among the press workers was found (p = 0.03). Based on this study, the prevention of exposure to toluene among high-risk workers is recommended.

The effect of cigarette smoking on urinary hippuric acid concentration in Thai workers with occupational exposure to toluene.

Urine hippuric acid determination is helpful for monitoring of group of workers at risk for exposure to toluene. However, some problems about the external source of variation are mentioned. Some studies have indicated that smoking is an important external source of variation for determination of urine hippuric acid level while the others stated the opposite findings. This study was conducted in an attempt to study the difference of urine hippuric acid between smoking and non smoking subjects in a press workers group. Urine samples were obtained from 46 workers (all male) who worked as press workers in the same press factory in Bangkok. The individuals were classified as control (non smoking, N = 26) and experimental (smoking, N = 20) according to their smoking. All samples were analyzed for hippuric acid level. The average urine hippuric acid level for the control were (0.35 +/- 0.31 mg/gCr) and experimental group (0.40 + 0.45 mg/gCr) were respectively. No significant difference was found between urine hippuric acid level between both groups. The data from the current study indicates that smoking does not influence the urinary hippuric acid levels in this study group.

Prevalence and intensity of third stage Gnathostoma spinigerum larvae in swamp eels sold in three large markets in Bangkok, Thailand.

Gnathostoma spinigerum is a common human tissue parasite in Thailand. The swamp eel is the major intermediate or paratenic host for this parasite. The high prevalence of the infective third stage larvae (L3) of this parasite in the rainy season has been noted in previous studies. During June 1999 (rainy season), we performed a cross-sectional survey of the prevalence and the intensity of G. spinigerum L3s in the livers of swamp eels that were obtained from three large Bangkok markets (Klong Toey, Pran Nok, and Tevej). Of a total of 785 livers, G. spinigerum L3s were found in 97: an infection rate of 12%. The prevalence rates in Klong Toey, Pran Nok, and Tevej markets were 13%, 10% and 14% respectively. There was no significant difference in the proportion of infected eels between the markets (p > 0.05). The intensity of L3 burden in the livers ranged from 1-17 larvae, with an average of 2.60 +/- 0.24 larvae (mean +/- SE). In this study a high prevalence of G. spinigerum L3s was found; there was no significant difference in the intensity of larvae in swamp eels between markets. These findings emphasize the importance of public health education: people need to be aware of the dangers of consuming raw or undercooked food.

A survey of trematode cercariae in Bithynia goniomphalos in northeast Thailand.

A survey of trematode larvae in the fresh water snail, Bithynia goniomphalos in the main water reservoir of Huai Thalaeng district, Nakhon Ratchasima Province, Thailand, was conducted. The study site is in an area with a high prevalence of Opisthorchis viverrini infection. Malacological samplings were made during the year 2000 to study the prevalence and intensity of infection. Parasitological examinations of 527 live snails were performed at the Veterinary Parasitology Laboratory, Chulalongkorn University. Of the 527 snails, only 16 (3.04%) were found to be infected with cercariae. Of these 16 snails, 75% were infected with Amphistome cercariae, 6.25% with Armatae cercariae and 18.75% with Virgulate cercariae. Most infected snails (75%) had a density of infection of less than 100 cercariae/snail. No snail was infected with cercariae of Opisthorchis spp. This snail was, therefore, unlikely to be the intermediate host of Opisthorchis viverrini in the main water reservior of Huai Thalaeng district.

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.

A survey of metacercariae in cyprinoid fish in Nakhon Ratchasima, northeast Thailand.

Metacercariae were recovered from freshwater fish taken from a stream in Lum Cha Muak, Nakhon Ratchasima Province, northeast Thailand during the year 2000. Seventy-nine cyprinoid fish comprising 3 species (52 Puntius leiacanthus, 22 Cyclocheilichthys armatus, and 5 Hampla dispar) were collected. The prevalence of infection with metacercariae was 51.9%. Only two genera of metacercariae were found: Haplochinae spp and Heterophyidae spp. Haplochinae metacercariae were found in all 3 species of fish, giving rates of infection of 95.5%, 20% and 1.9% for Puntius leiacanthus, Cyclocheilichthys armatus and Hampla dispar respectively. Heterophyidae metacercariae were found only in Puntius leiacanthus, whose infection rate was 30.77%. There were fish intected at the rate of 3.8% with unclassified metacercariae. Interestingly, no fish infected with Opisthorchis viverrini metacercariae were found, which is at odds with previous reports from Thailand in which a higher infection rate was given. This is the first report of fish infected with Haplorchinae spp in Thailand.

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).