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Biomedical subjects

Viroj Wiwanitkit

Publications and source records attributed to Viroj Wiwanitkit.

At least 163 records · Page 9Linked to original sources
PubMed2002

Motility of minute intestinal fluke, Haplorchinae spp, metacercariae in fish dishes prepared by different uncooked methods.

CONTEXT: Fish-borne trematode is a worldwide problem, with the number of people infected by liver flukes alone estimated at 21 million. In addition to the major liver flukes, Opisthorchis viverrini and Clonorchis sinensis, several types of intestinal flukes also use cyprinoid fish as the intermediate host. Traditional ingestion of undercooked and uncooked fish preparations is a major factor in pathogen acquisition. OBJECTIVE: To examine the motility of Haplorchinae spp metacercariae in matched minnows using a number of preparation methods that mimic traditional practices. DESIGN: Several freshly killed freshwater fish, Cyclocheilichthys armatus, were purchased from the local market and sent to the authors' laboratory to be examined under a stereoscopic microscope for active Haplorchinae spp metacercariae. A total of 10 fish were infected with many active metacercariae and used in the preparation of uncooked fish dishes. Five different raw fish dishes that mimic traditional meals (2 fishes/dish) were prepared using the following methods: 1) left to dry at room temperature; 2) frozen at -20 Celsius; 3) refrigerated at 4 Celsius; 4) marinated in saline (5% sodium chloride solution); and 5) marinated in 5% acetic acid solution to mimic traditional vinegar. The motility of the metacercariae in each of these dishes was examined under a stereoscopic microscope. Motility was estimated as the level of activity or degeneration of the metacercariae at the start of the experiment and then every 30 minutes until all the parasites appeared degenerate (and therefore, presumably not viable). RESULTS: Degeneration of the parasites was slowed by cooling: degeneration of all metacercariae took approximately 5 hours in the refrigerated or frozen fish, compared with 3 hours in all other dishes left at room temperature. CONCLUSION: The study substantiates the epidemiologic data demonstrating transmission of these types of pathogens despite freezing, pickling, and salting. Although the tradition of eating uncooked fish is deeply rooted in Thailand, constant efforts need to be made to discourage this practice.

Acetic Acid↗
PubMed2002

LDL-cholesterol lowering effect of a generic product of simvastatin compared to simvastatin (Zocor) in Thai hypercholesterolemic subjects -- a randomized crossover study, the first report from Thailand.

BACKGROUND: It is commonly agreed that people with a high blood LDL-cholesterol will have a higher risk of coronary artery disease (CAD) than people with low blood LDL-cholesterol. Due to the increasingly high costs of medication in Thailand, the government has set up several measures to combat the problem. One of such strategies is to promote the utilization of locally manufactured drug products, especially those contained in the National Drug List. Simvastatin, an HMG-CoA reductase inhibitor, is listed as an essential drug for the treatment of hypercholesterolemia. Here, we reported the study on the LDL-cholesterol-lowering effect of a generic simvastatin product in comparison with the Zocor, in 43 healthy thai volunteers. METHOD: The generic product tested was Eucor, locally manufactured by Greater Pharma Ltd., Part, Thailand, and the reference product was Zocor (Merck Sharp & Dohme, USA). The two products were administered as 10-mg single oral doses in a two-period crossover design. After drug administration, serial blood samples were collected every 4 weeks for 16 weeks. The major parameter monitored in this study was blood LDL-cholesterol. RESULT: After taking the drugs for the first 8 weeks, no statistically significant difference was detected in blood LDL-cholesterol between the first (Zocor-treated) and the second (Eucor-treated) groups. After crossover and taking drugs for further 8 weeks, a similar result was obtained, i.e., no significant difference in blood LDL-cholesterol between the first (Eucor-treated) and the second (Zocor-treated) groups was observed. Upon completion of the 16-week study, there was also no statistically significant difference in the changes of all tested blood parameters between the two products (randomized block ANOVA, N = 37). Only minor side effects, mainly dizziness and nausea, were observed in both products. CONCLUSION: Our study demonstrated no significant differences in the therapeutic effect and safety between the generic and original simvastatin products.

Adult↗
PubMed2002

High blood lead level among garage workers in Bangkok, public concern is necessary.

Lead is an important toxic metal agent found in many industrial processes in the present day. Lead exposure must be of particular concern because of ongoing exposure to thousands of workers in the industrial plants and recent research indicating that asymptomatic lead exposure can result in chronic toxicity manifestations. Therefore, determination and control lead exposure among the risk workers is very necessary. Like other developing countries, lead pollution becomes an important public health problem of Thailand, especially for the big cities as Bangkok but relatively few of these countries have introduced policies and regulations for significantly combating the problem. We set this pilot study to determine the blood lead levels by anodic stripping volammetry (ASV) method as a marker for lead exposure among the occupational exposed and control subjects. Totally 89 subjects, 20 control subjects and 69 garage workers (52 mechanics and 17 dye sprayers), as the representatives of occupational exposed subjects, were included into this preliminary study. The mean blood lead level in the control group was 0.32 +/- 0.07 micromol/l. The mean blood lead level in the mechanics group was 0.42 +/- 0.13 micromol/l. The mean blood lead level in the dye sprayers was 0.58 +/- 0.07 micromol/l. Significant higher blood lead levels among the mechanics and dye sprayer groups were observed (P < 0.05). Based on this study, the considerations for prevention of possibly exposure to lead among the high-risk workers as public health policies was recommended.

Air Pollutants, Occupational↗
PubMed2002

An overview of hepatitis B serology screening check-up program among Thai workers.

In Thailand, hepatitis B virus (HBV) infection is hyperendemic; approximately 5 million Thais are chronic HBV carriers. Here, an overview of hepatitis B serology among Thai workers who got the screening check-up program of King Chulalongkorn Memorial Hospital during January 1998 to December 2000 is reported. The data from hepatitis B serology examinations of 650 Thai workers who visited the Out-Patient Division, King Chulalongkorn Memorial Hospital during the study period for the screening program before starting work was analyzed. Among the subjects examined, 107 were HBsAg-, anti-HBc-; 64 were HBsAg+, anti-HBc+; and 479 were HBsAg-, anti-HBc+. Not unexpectedly, in the present study, the rate of chronic hepatitis B infection among the subjects is high (9.8%). Screening for parasitic infection among this population can help decrease the development of late complications as well as rejection of laborers by their employers.

Employment↗
PubMed2002

A note on the prevalence of anti-HIV seropositivity in the Preadmission Clinic of the largest Thai Red Cross Society clinic.

Clinical decision-making regarding operative procedures will be influenced when the patient is known to be anti-HIV, so his or her status should be discussed with the patient and clinician responsible for other aspects of his or her care. Here, we reviewed serology screening for anti-HIV in a 1-year period at the PreAdmission Clinic of King Chulalongkorn Memorial Hospital, the largest Thai Red Cross Society hospital. A total of 463 patients, 215 males and 248 females, were investigated, and four cases (all males) were determined to have anti-HIV seropositivity. The infection rate was 0.86%, similar to that of previous surveys of the general population. According to our study, 75% of the HIV-seropositive patients did not know their HIV status before our screening, and most of the infected cases (50%) underwent sex change surgery. The patients who underwent elective surgery in our clinic were usually anti-HIV seronegative. The risk group of our patients seems to be the sexual dysphorian patients who underwent sex change surgery. Additional screening tests for other infectious agents such as hepatitis B and hepatitis C virus is recommended. However, in a setting where HIV infection is common, such as in Thailand, the physician should practice universal precautions since any serological test poses dangers during diagnosis.

Ambulatory Care↗
PubMed2002

The prevalence of hepatitis B seropositivity among patients with cholangiocarcinoma.

Cholangiocarcinoma is a malignancy of the biliary duct system. Presently, these malignant biliary tract diseases are common among the people in Southeast Asia, with the world's highest prevalence in northeastern Thailand and Laos. This carcinoma tends to grow slowly and to infiltrate the walls of the ducts, dissecting along tissue planes and leading to biliary tract obstruction. Recently, hepatitis virus-associated chronic hepatitis or cirrhosis has been suggested to be involved in the pathogenesis of cholangiocarcinoma. Here, we report the prevalence of hepatitis B seropositivity among Thai patients with cholangiocarcinoma. A total of 55 patients with cholangiocarcinoma, who were admitted to King Chulalongkorn Memorial Hospital, Thailand, during 1992-2001, with known hepatitis B serology was selected for further prevalence study. Of the 55 cases (32 males and 22 females), hepatitis B seropositivity was found in five cases (three males and two females), giving a total prevalence rate equal to 9.1% (9.4% for male and 9.2% for females). Since hepatitis B infection is believed to be a risk factor in the development of cholangiocarcinoma, and both cholangiocarcinoma and hepatitis B infection are common in Thailand, screening and vaccination for hepatitis B may be a useful strategy to decrease the high rate of cholangiocarcinoma in Thailand. Further long-term study to study the relation of hepatitis B infection and cholangiocarcinoma is recommended.

Bile Duct Neoplasms↗
PubMed2002

The rate of anti-HIV seropositivity among donated cadavers: experience in a cadaver donation center.

Cadavers are crucial for the medical education provided by medical schools. However, currently, donation is the only way to obtain cadavers for education in Thailand. Moreover, some traditional beliefs result in insufficient numbers of cadavers. Apart from finding donors, the occupational health of the workers in the cadaver donation center and the users, the medical students, residents, and staffs should be addressed. Screening for anti-HIV in donated organs is the current trend in transplantation medicine. Therefore, screening for anti-HIV in donated cadavers is useful. Here, we report the rate of anti-HIV seropositivity in cadavers in a 1-year period in our setting, the largest Thai Red Cross Society hospital. Of the total 84 cadavers received, two cadavers (2.4%) were anti-HIV seropositive. With the increasing rate of anti-HIV, screening for anti-HIV serology in donated cadavers for medical teaching is of great benefit.

Cadaver↗
PubMed2002

Prevalence of anti-HIV seropositivity in Myanmar migrators in a rural area of Thailand.

Although the prevalence of anti-HIV seropositivity in the Thai population has decreased in the recent years, migration of Myanmar labors as carriers into Thailand may increase the prevalence of anti-HIV seropositivity. Screening is recommended for the Myanmar migrators. Of interest, the epidemiology of anti-HIV seropositivity in Myanmar migrators has not been precisely determined. In this study, we report the prevalence of anti-HIV seropositivity in Myanmar migrators in a rural community in the Southern Region of Thailand with a high density of Myanmar migrators as fishermen. We analyzed the screening data for anti-HIV seropositivity among 250 Myanmar migrators (169 males and 81 females) who were in Thailand for less than 1 month. The anti-HIV seropositivity rate among these Myanmar migrants was 3.2%. The rates in males and females were 4.1% and 1.2%, respectively. Since these migrants can carry the disease into Thailand, screening tests as a prevention strategies are necessary.

Adult↗
PubMed2002

A randomized crossover study to evaluate LDL-cholesterol lowering effect of a generic product of simvastatin (Unison Company) compared to simvastatin (Zocor) in hypercholesterolemic subjects.

It is agreed that people with a high blood LDL-cholesterol level will have a higher risk of coronary heart disease (CAD) than those with low blood LDL-cholesterol level. Because of the present National Drug Strategy of Thailand, the promotion of "in-country production" of a generic drug has been established. Simvastatin is one of the drugs in this strategy. In this, the primary report of a randomized crossover study with washout period for a cholesterol lowering effect in a generic product of simvastatin (Unison company) which was compared to the original simvastatin (Zocor) hypercholesterolemic to the subjects were presented. Simvastatin used in this study were derived from two sources. The first group was the original product (Zocor), dosage 10 mg, Lot No IC4/36(N) from Merck Sharp & Dohme Company and the second group was a generic product, dosage 10 mg, Lot No T05/080 and T06/109 from Unison Company. All simvastatin tablets from the first and second sources were inserted into closed capsule of the same shape and called drug A and drug B, respectively. Both the physician in-charge and the subjects in this study were blinded for the content inside the capsule (Double blind). Thirty drug capsules were put into a sachet and distributed to the subject at each visit. The interval between each visit was 4 weeks. All subjects were asked to bring back the residual capsule within the sachet to the researcher at each visit in order to evaluate the subject's compliance. All subjects had physical examination and blood tests at each visit. Furthermore, all subjects were advised to practice diet control and regular in-take of the drug capsule daily after their evening meal. All 48 subjects were randomly allocated into 2 groups. This study was run as a randomized crossover study. After taking the drugs for the first 8 weeks, no statistically significant difference of blood LDL-cholesterol between the first and second group was detected. After a 4 week washout period, crossover and taking the drugs for the last 8 weeks, no statistically significant difference of blood LDL-cholesterol between the first and second group was detected. At the end of this study, comparing both groups by ANOVA crossover test, no statistically significant difference of blood LDL-cholesterol between the first and second group was detected.

Adult↗
PubMed2002

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.

Adult↗
PubMed2002

Expected value of serum soluble transferrin receptor, erythropoietin and ferritin and their correlation among healthy non-anemic Thai children.

Transferrin receptor (TfR) is a glycoprotein which mediates the entry of ferric transferrin from the extracellular compartment into the cells. The measurement of sTfR has become a widely used tool in assessing erythropoiesis but its use has mainly been restricted to research laboratory settings. In Thailand, there are only a few reports concerning the sTfR. The authors studied the expected value of sTFR as well as other basic parameters for monitoring of erythropoiesis as erythropoietin (EPO) and ferritin among a sample of non-anemic healthy Thai children. In addition, correlation was done between each pair of studied parameters. Expected range for sTfR level for the healthy controls in this study was 1.761 to 2.034 mg/L. Expected range for serum EPO level for the healthy controls in this study was 19.445 to 34.176 mU/ml. Expected range for serum ferritin level for the healthy control from this study was 67.895 to 96.692 ng/ml. Of interest, poor correlation among the three studied parameters, sTfR, serum EPO and serum ferritin was observed in this study.

Adolescent↗
PubMed2002

Evaluation of the Sysmex UF-100 automated urinalysis analyzer and comparative study with JCCLS reference method.

Microscopic urine sediment analysis has been accepted as the mainstay test for examining urine cells and particles. Although it provides essential information for clinicians about disease states in the patients, it is a high-volume and laborious procedure. Therefore, an automated analyzer was developed recently and has just been introduced to Thailand. In this study, the authors evaluated the analytical performance of this new automated urine analyze. Also a comparative study was performed between the UF-100 test results and those of JCCLS reference method. In evaluation of the Sysmex UF-100 automated urinalysis analyzer, both precision and linearity studies were performed. Between-run CVs for RBCs (mean = 182.46/microl), WBCs (mean = 193.37/microl), ECs (mean = 70.05/microl) and casts (mean = 12.21/microl) were 7.74 per cent, 5.52 per cent, 21.32 per cent and 7.69 per cent, respectively. Concerning the within-run CVs for the RBC analysis, the CV ranged from 16.28 per cent for low numbers of RBCs (35.67/microl) to 2.93 per cent at RBC concentrations (712.13/microl). Concerning within-run precision for the WBC analysis, the CV ranged from 22.31 per cent for low numbers of WBCs (WBCs 12.53/microl) to 2.07 per cent at a WBC count of 211.01/microl. Within-run precision ranged from 11.36 per cent at 24.99 ECs/microl to 6.18 per cent at 53.08 ECs/microl. Within-run precision for casts varied from 35 per cent for samples with 1.33 casts/microl to 12.38 per cent for samples with 4927.35 casts/microl. From the comparative study, good agreements (p < 0.05) were obtained between UF-100 and JCCLS reference method for RBCs counts (p = 0.000, r = 0.974) and WBCs counts (p = 0.000, r = 0.913). However, fair agreement (p > 0.05) was obtained between UF-100 and JCCLS reference method for ECs counts (p = 0.017, r = 0.212) and casts counts (p = 0.624, r = 0.044). In conclusion, the UF-100 analyzer is a new useful analyzer although it cannot be a substitute for microscopic sediment examination.

Automation↗
PubMed2002

A prevalence of Cryptosporidium infections among Thai HIV-infected patients.

The prevalence of Cryptosporidium in 156 HIV-infected Thai patients who had acute diarrheal illness at Bamrasnaradura Infectious Diseases Hospital, was studied. This cross-sectional study was performed from March to August in year 2001. The patients ranged in age from 1 month-65 years old. A stool sample from each subject was stained to find the oocysts by modified Ziehl Nelson carbolfuchsin staining. According to the present study, a diagnosis of Cryptosporidium parvum infection was found in 20 patients (11 males and 9 females). The prevalence of cryptosporidiosis in the present series was 12.8 per cent (10.0% in males and 19.1% in females). This infection rate between males and females was not significantly different. Comparing this prevalence to a report in the previous 5 years in the same hospital, the same high rate can be seen.

AIDS-Related Opportunistic Infections↗