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Biomedical subjects

Viroj Wiwanitkit

Publications and source records attributed to Viroj Wiwanitkit.

At least 181 records · Page 10Linked to original sources
PubMed2002

Cost-effective study of determination methods for low-density lipoprotein by new direct assay compared to Friedewald's formula calculation in hypercholesterolemic subjects.

OBJECTIVE: To study the cost effectiveness of determination methods for low-density lipoprotein by new direct assay compared to Friedewald's formula calculation. DESIGN: descriptive study. MATERIAL: Fasting serum from 100 subjects with a history of hypercholesterolemia. METHOD: Specimens were determined for total cholesterol, high-density lipoprotein (HDL) and triglyceride using automated clinical chemistry, as the basic information in calculation of LDL level. Each specimen was also processed by direct LDL assay by the same automation. Correlation of the results from both methods was analyzed. Cost effectiveness analysis was then performed. RESULTS: The least-squares equation from comparing direct LDL assay to calculation method gave Y = 0.897X + 20.42 (r = 0.996, p < 0.05). According to the present study, the cost per utility of the direct assay method (47.54 baht) was more expensive than the calculation method (29.59 baht). CONCLUSION: The results from both methods were well related. However, the cost per utility of the calculation method is cheaper, therefore, the authors recommend the use of the calculation method rather than the direct assay for follow-up of LDL level in hypercholesterolemic patients.

Blood Chemical Analysis↗
PubMed2002

Leukocyte counts in cerebrospinal fluid with the automated hematology analyzer, Technicon H*3.

BACKGROUND: Presently, the counting of leukocytes in cerebrospinal fluid (CSF) is still performed manually. This requires sufficiently experienced medical technologists. At present, specific automated systems for CSF cell counting are not available. In this study, we evaluated the use of the automated hematology analyzer, Technicon H*3 in the analysis of cerebrospinal fluid (CSF). METHODS: We tested the hematology analyzer, Technicon H*3, which was not designed for CSF analysis. Sixty CSF samples were analyzed by the analyzer, Technicon H*3. Then the counts obtained were compared with the manual microscopic method. RESULTS: Linearity was tested by both plasma and normal saline solution (NSS). Concerning the NSS dilution, a good correlation can be observed at theoretical number of WBC > 30 cells/microL and so did the plasma dilution. The results of the comparison of both methods used for the determination of total leukocytes in the CSF gave a good correlation (r = 0.984). Concerning the determinations of neutrophils and lymphocytes, the correlation coefficients were 0.855 and 0.835, respectively. CONCLUSIONS: According to our study, the use of this automated analyzer for cell counting in CSF is probably feasible. The high degree of accuracy and linearity that is offered by the analyzer should prompt us and the manufacturers to remedy the interfering factors as described by improving the algorithms. Once this is done, these analyzers may be very useful for cell counts in CSF.

Automation↗
PubMed2002

Serum erythropoietin levels in pediatric patients with beta-thalassemia/hemoglobin E.

Presently, the assays for serum erythropoietin (EPO) seem valuable tools for clinical research, but their roles in routine clinical practice remain undefined. Some studies mentioned that serum EPO measurements, which are now easily and reliably performed, should be used in monitoring the therapy of beta-thalassemia major. Here, we report our experience in the determination of serum EPO in children with beta-thalassemia/Hb E and also compared the results with those in hemoglobin E trait, beta-thalassemia/Hb E as well as healthy non-anemic controls of similar age. Fifty five transfusion-dependent beta-thalassemia/Hb E, fifteen hemoglobin E trait, five beta-thalassemia trait cases and twenty five controls were studied for their serum EPO levels. The mean (S.D.) EPO concentrations were 19.94 (17.40) U/L for the controls, 16.13 (8.47) U/L for the hemoglobin E trait, 24.40 (8.20) U/L for the beta-thalassemia trait and 372.19 (432.04) U/L for the beta-thalassemia/Hb E cases. The mean EPO concentration for the normal controls was near to that of the hemoglobin E trait (P = 0.06) and beta-thalassemia trait (P = 0.25) but eighteen times less than that for the beta-thalassemia major cases (P<0.0005).

Blood Transfusion↗
PubMed2002

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.

Case-Control Studies↗
PubMed2002

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.

Animals↗
PubMed2002

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.

Animals↗
PubMed2002

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).

Animals↗
PubMed2002

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.

Animals↗
PubMed2002

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.

Animals↗
PubMed2002

Parasitic infections in Thai workers that pursue overseas employment: the need for a screening program.

Stool examination is a requirement of the screening program for Thai workers seeking overseas employment. We report on the prevalence of intestinal parasitic infections among these workers; the stool examination results of 2,213 Thai workers who visited the Out-patients Department of the King Chulalongkorn Memorial Hospital between September 2000 and January 2001 were analysed. One hundred and thirty-five (6.1%) were found to be infected with 1 or 2 species of parasite. There were 54 (40%), 47 (34.8%), and 25 (18.5%) cases infected with nematodes, platyhelminths and protozoa, respectively. The commonest parasite was Opisthorchis viverrini (28.9%). Most nematode infections were due to Strongyloides stercoralis (19.2%); most protozoal infections were due to Giardia lamblia (17.0%). Mixed infections were found in 9 cases. Not unexpectedly, the rate of intestinal parasitic infection among Thai workers remains high. Screening for the parasitic infections among these workers can help to decrease their rate of rejection by the countries in which overseas employment is sought.

Employment↗
PubMed2002

Biological false reactive VDRL tests: when to re-test?

Syphilis serology is a basic screening test for the workers who want to go abroad. Many countries reject migrant workers who have reactive syphilis serology. Biological false reactives warrant repeated syphilis serology. We prospectively studied 30 patients (25 males and 5 females) who had biological false reactive VDRL tests (VDRL reactive, confirmatory TPHA negative). Affirmative tests for syphilis serology for all cases were performed every two weeks. On follow-up, the expected range (95% CI) for seroconversion was between 9.25 and 10.49 weeks. Most cases (25 cases) completely returned to the VDRL non-reactive stage within 10 weeks; three cases completely returned within 6 weeks; 2 cases completely returned within 14 weeks. It is recommended that repeat syphilis serology be conducted 10 weeks after an initial biological false reactive VDRL test.

Cardiolipins↗
PubMed2002

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.

Adolescent↗
PubMed2002

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.

Case-Control Studies↗
PubMed2002

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.

Architectural Accessibility↗
PubMed2002

Cadaver donation: a retrospective review at the King Chulalongkorn Memorial Hospital, Bangkok.

Cadavers are a crucial resource for medical education. Currently, donation is the only means of obtaining cadavers for use in Thai medical schools. Some traditional beliefs result in an insufficient number of donated cadavers. This shortage of cadavers may affect the quality of medical training. We report on the present situation regarding the quantity and usage of donated cadavers in the King Chulalongkorn Memorial Hospital, Bangkok, during the eight years between 1993 and 2000. During this period, 19,674 cadavers became available (2.459.3 +/- 1,243.7 cadavers/year) as the result of advanced donation. However, only 619 cadavers (3.1%) were actually obtained. Poor preservation and delayed delivery contributed to the underutilization; furthermore, some cadavers were reclaimed. In order to increase the number of cadavers and maintain the quality of medical education, the appropriateness and importance of cadaver donation should be emphasized to the public.

Attitude to Health↗
PubMed2001

Types and frequency of preanalytical mistakes in the first Thai ISO 9002:1994 certified clinical laboratory, a 6 - month monitoring.

BACKGROUND: Reliability cannot be achieved in a clinical laboratory through the control of accuracy in the analytical phase of the testing process alone. Indeed a "mistake" can be defined as any defect occuring during the testing process. In the analysis of clinical specimens, there are many possible preanalytical sources of error. Therefore, the application of quality system to laboratory testing requires total quality management throughout the laboratory process, including the preanalytical and postanalytical phases. ISO 9002:1994 is a model for quality assurance in production, installation, and servicing, which includes a number of clauses providing guidance for implementation in clinical laboratories. Our laboratory at King Chulalongkorn Memorial Hospital, the largest Thai Red Cross Society hospital, is the first clinical laboratory in Thailand with ISO 9002:1994 certified for the whole unit. METHOD: In this study, we evaluated the frequency and types of preanalytical mistakes found in our laboratory, by monitoring specimens requested for laboratory analyses from both in-patient and out-patient divisions for 6 months. RESULT: Among a total of 935,896 specimens for 941,902 analyses, 1,048 findings were confirmed as preanalytical mistakes; this was a relative frequency of 0.11 % (1,048/935,896). A total of 1,240 mistakes were identified during the study period. Comparing the preanalytical mistakes to other mistakes in the laboratory process monitored in the same setting and period, the distribution of mistakes was: preanalytical 84.52 % (1,048 mistakes), analytical 4.35 % (54 mistakes), and postanalytical 11.13 % (138 mistakes). Of 1,048 preanalytical mistakes, 998 (95.2%) originated in the care units. All preanalytical mistakes, except for 12 (1.15 %) relating to the laboratory barcode reading machine, were due to human error. CONCLUSION: Most mistakes occurred before samples were analysed, either during sampling or preparation for analysis. This suggests that co-operation with clinicians and personnel outside the laboratory is still the key to improvement of laboratory quality.

Journal Article↗
PubMedDate not supplied

Energy consumption for the formation of hemoglobin A1c: a reappraisal and implication on the poor-control diabetes mellitus patients.

Diabetes mellitus (DM) is a frequent disorder affecting individuals of all ages. Glycohemoglobin has a key role in the assessment of glycemic control in diabetic patients. Several studies have clearly shown that improved glycemic control is strongly associated with decreased development and/or progression of diabetic complications. The chemical reaction of glycosylation in formation of hemoglobin A(1c) (HbA(1c)) has been described for decades. Here, the author performed a reappraisal on the bonding energy based on quantum chemical analysis. The author calculated the bonding energy of the reaction and found that the reaction is a type of "energy-consuming reaction." In addition, the author gives further implication of the findings on the poor-control DM patients. The author hereby proposed that the nature of energy-consuming reaction in formation of hemoglobin A(1c) (HbA(1c)) is a main underlying for the energy loosing in poorly controlled DM patients. Gathering of the energy from the nearby cellular compartment during formation of HbA(1c) might be an important pathological process.

Diabetes Mellitus↗