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Biomedical subjects

S Pungpak

Publications and source records attributed to S Pungpak.

At least 19 recordsLinked to original sources
PubMed2001

Prevalence of Opisthorchis viverrini infection among villagers harboring Opisthorchis-like eggs.

The precise occurrence of Opisthochis viverrini infection in humans, who were positive for Opisthorchis-like eggs in a stool examination, was determined using the potassium permanganate staining method. In the 68 specimens examined, there were more individual O. viverrini eggs (38.24%) than singular Haplorchis taichui eggs (29.41%). One-fourth of the total specimens contained a mixed infection of O. viverrini and H. taichi eggs. The median ratio of O. viverrini: H. taichui eggs in mixed infection cases was 2.29 (min = 1, max = 17.5). It is suggested that chemotherapy with praziquentel treatment should be given to patients who are positive for O. viverrini-like eggs.

Animals↗
PubMed1998

Treatment of Opisthorchis viverrini and intestinal fluke infections with Praziquantel.

The study was carried out from September to November 1997 in Phrae Province of northern Thailand. A total of 95 adult patients with Opisthorchis-like ova in their stools were randomly treated with two different manufactured Praziquantels. Group 1, consisting of 49 patients, received a single dose of 40 mg per kg Praziquantel manufactured by the Thai Government Pharmaceutical Organization. Group 2 (46 patients) received Biltricide at the same dosage. Haplorchis taichui, H. yokogawai, Echinostome spp., O. viverrini, Taenia saginata and Enterobius vermicularis were expelled in the stools after treatment. Minute intestinal flukes were detected in 64% of patients. O. viverrini was found in lower proportion of 17%. By formalin-ether concentration examination one stool specimen from each patient, the cure rate in both groups on the 30th day of treatment was 100%. The side effects of the two different Praziquantel treatments were mild with no significant difference. Praziquantel, regardless of its manufacture, proved effective against O. viverrini and other minute intestinal flukes (H. taichui, H. yokogawai and Echinostome spp).

Adolescent↗
PubMed1997

Opisthorchis viverrini infection in Thailand: studies on the morbidity of the infection and resolution following praziquantel treatment.

A community study on opisthorchiasis was conducted in Prachinburi Province in eastern Thailand during 1990-1992. The morbidity from opisthorchiasis in the community and reversibility of biliary pathology following treatment with praziquantel at a single dose of 40 mg/kg were assessed by longitudinal investigations of clinical, laboratory, and ultrasonographic changes. A total of 913 voluntary subjects infected with Opisthorchis viverrini were randomly selected for longitudinal study, and 579 subjects without liver fluke infection were recruited as controls. The majority of the study group suffered from mild and moderate infections that were associated with nonspecific gastrointestinal symptoms. Grade I and II ultrasonographic changes, which indicated chronic inflammation of the biliary tract and gallbladder, were detected in 32% of the infected individuals. Clinical symptoms and ultrasonographic changes were common in subjects 21-40 years of age and older. Satisfactory resolution of morbidity was observed during two years follow-up on days 0, 60, 180, 360, and 720, as shown by significant clinical improvement, normalization of laboratory parameters, and downgrading of ultrasonographic abnormalities. Portable ultrasonography has proved to be a reliable noninvasive technique in the evaluation of the morbidity due to opisthorchiasis in rural areas.

Adolescent↗
PubMed1997

Two doses of artemether/mefloquine or artesunate/mefloquine combination for multidrug resistant falciparum Malaria.

Plasmodium falciparum in Southeast Asia is highly resistant to chloroquine, sulfadoxine/ pyrimethamine, quinine and even mefloquine. The use of two doses of short course artemether/mefloquine combination has been shown to be effective in a recent study. In the present study, we have assessed the efficacy of short course treatment with artesunate/mefloquine, in comparison with artemether/mefloquine in patients with multidrug resistant falciparum malaria. Ninety-nine Thai male patients who sought consultation at Makham Malaria Clinic, Chantaburi (eastern part of Thailand), were randomized to receive either the combination of artemether (150 and 100 mg; group A) or artesunate (150 and 100 mg; group B) with mefloquine (750 and 500 mg) at 24 hours apart. The follow-up was on days 1, 2, 7, 14, 21, 28, 35 and 42. Patients in both groups showed a rapid initial response to treatment; fever and parasite were cleared within 48 hours in 100 and 100% vs 91.8 and 96%, for group A vs B, respectively. All patients in group A had completed the 42 day-follow up; however, two patients in group B did not finish the 42-day follow-up. The cure rate was 100% in either group. No serious adverse effects were found. Artemether or artesunate with mefloquine given two doses at 24 hours apart can be used as effective alternative treatment regimens for multidrug resistant falciparum malaria.

Acute Disease↗
PubMed1995

Serum antibody responses in opisthorchiasis.

We evaluated an enzyme-linked immunosorbent assay using crude parasite homogenates as a diagnostic test for Opisthorchis viverrini infection in humans. Serum antibody (Ab) responses to O. viverrini adult worm homogenate (AWH) and metacercaria homogenate (MH) were studied in 83 infected residents of an opisthorchiasis-endemic area in Thailand. Elevated levels of Ab persisted for over 1 year following curative treatment with praziquantel, and cross-reactivity to O. viverrini AWH and MH antigens was observed in sera from individuals with other parasitic infections. Serum Ab to crude AWH and MH are therefore unsuitable for immunodiagnosis since they may be non-specific and would not differentiate between ongoing and past infection.

Animals↗
PubMed1994

Possible protective immunity in human opisthorchiasis.

Chronic infections with the liver flukes Opisthorchis viverrini and Clonorchis sinensis affect over 30 million people in southeastern Asia. With ongoing exposure, reinfection readily occurs following curative treatment and cumulative infections result in significant morbidity and a predisposition to cholangiocarcinoma. Though protective immunity has never been described in human opisthorchiasis, heterogeneity in worm burden occurs and a small number of exposed residents of endemic areas remain apparently uninfected. To explore the nature of this heterogeneity, we compared levels of serum antibody (Ab) to O. viverrini measured by an enzyme-linked immunosorbent assay in 83 stool egg-positive and 49 stool egg-negative residents of an O. viverrini-endemic area in Thailand. Compared to the egg-positive residents, the egg-negative group had significantly higher levels of immunoglobulin (Ig)G, IgA and IgM to adult worm homogenate (AWH) and total Ab to metacercaria homogenate (MH). Furthermore, immunoblot analyses revealed that a significantly higher proportion of sera from the egg-negative residents had IgA reactivity against a 38-kDa AWH antigen and IgM reactivity against carbohydrate epitopes of a 42-kDa AWH glycoprotein antigen. These findings support a hypothesis that the egg-negative group includes individuals who may be immunologically resistant to this usually chronic infection.

Adolescent↗
PubMed1993

Pharmacokinetics of praziquantel in patients with opisthorchiasis.

The pharmacokinetics of praziquantel was investigated in 9 Thai male patients with asymptomatic opisthorchiasis (stool positive) and 9 patients (6 males, 3 females) with moderately advanced infection (hepatomegaly). The geometric means of the pretreatment Opisthorchis viverrini egg count in these patients were 2,950 vs 4,468 eggs per gram of stool. The results indicate the impairment of metabolism of praziquantel in the moderately advanced stage opisthorchiasis. The pharmacokinetics of the drug in these patients during the acute infection was markedly altered when compared with that after recovery and in patients with early stage of the infection. The clearance rate (Cl/f) was significantly reduced [medians and ranges of 106 (43-242) vs 192 (112-692) and 171 (133-427) ml/min/kg] and the t1/2z and MRT were prolonged [t1/2z: 3.8 (2.0-6.2) vs 2.7 (1.7-4.3) and 2.3 (1.7-2.8) hours; MRT: 6.2 (3.2-11.0) vs 4.6 (2.7-6.2) and 4.5 (2.9-5.1) hours]. In addition, AUCo-alpha was significantly greater [6.0 (2.5-15.6) vs 3.5 (0.6-6.0) and 3.9 (1.6-5.0) micrograms hour/ml].

Adult↗
PubMed1993

Trematode infections. Opisthorchiasis, clonorchiasis, fascioliasis, and paragonimiasis.

The parasitic diseases of the liver and lung are caused by trematodes or flukes--Opisthorchis viverrini, O. felineus, Fasciola hepatica, and Paragonimus westermani. Humans get infected by eating the second intermediate host of the fluke, for example, fish, crab, or water plant. The disease runs a chronic course. The diagnosis is made by the recover of eggs in stools or sputum, or by serodiagnosis. Praziquantel is the drug of choice except in falcioliaisis.

Adult↗
PubMed1992

Detection of Opisthorchis viverrini antigens in stools using specific monoclonal antibody.

Detection of Opisthorchis viverrini antigens in stools using specific monoclonal antibody. International Journal for Parasitology 22: 527-531. A sandwich enzyme-linked immunosorbent assay (ELISA) was developed for detecting Opisthorchis viverrini antigen in faecal extracts of four groups of individuals. These were 24 patients with O. viverrini infection only (group 1), 31 patients with O. viverrini and other parasitic infections (group 2), 141 patients with other parasitic infections (group 3) and 21 normal, parasite-free individuals (group 4). The first antibody used in the ELISA was polyclonal immunoglobulin G prepared from the serum of a rabbit previously immunized with crude extract of O. viverrini. The second antibody was monoclonal antibody specific to an antigen located in the worm tegument and muscular tissue. Sensitivity of the assay was 31% while specificity was 100%. Considerations for improving the sensitivity are discussed.

Animals↗
PubMed1992

Separation and characterization of adult worm proteins and glycoproteins from the liver fluke Opisthorchis viverrini.

Detailed studies of liver fluke proteins and antigens are necessary to facilitate further investigation of the human immune responses to these parasites. Accordingly, Opisthorchis viverrini antigens were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. We initially encountered excessive background smearing, vertical streaking, and indistinct bands that were similar to problems previously described by investigators studying this and other trematodes including Schistosoma mansoni. These problems were especially evident with silver staining of proteins and occurred despite the extensive use of protease inhibitors. They were minimized by using mini (vs. large) SDS-PAGE and Coomassie blue protein staining. With the latter 2 techniques, adult worm somatic proteins and excretory-secretory products were separated and characterized. Immunoblots using rabbit anti-adult worm sera demonstrated that some of these proteins were antigens common to both the adult and metacercarial stages. Several of these antigens also corresponded (according to molecular weight) to glycoproteins, detected by concanavalin A blotting. These findings form a base for subsequent studies of the human immune response to liver fluke infection.

Animals↗
PubMed1991

Specific monoclonal antibodies to Opisthorchis viverrini.

A Balb/c mouse was immunized with a crude soluble antigen of Opisthorchis viverrini adult worms (OVAA) over a period of 7 months. Spleen cells from the immune mouse were fused with Sp2/0 myeloma cells. Among the 264 tissue culture wells containing the fused cells, cells of 96 wells (36%) produced antibodies to the immunizing agent. Antibodies produced by cells in several wells reacted with antigens from other species of parasite. Cells of 17 wells produced antibodies specific only to OVAA, thus cells from three representative wells were cloned by limiting dilution. Hybrids obtained produced antibodies which could be classified according to their tissue specificities into three groups. The first group of antibodies reacted strongly to the worm integument and weakly with the muscles while those belonging to the second group reacted only to muscles of the worms. The monoclonal antibodies of the third group gave a positive reaction to both muscles and tegument.

Animals↗
PubMed1990

Fecal egg output in relation to worm burden and clinical features in human opisthorchiasis.

A study of the relation of fecal egg excretion to worm burden and clinical features was carried out in 45 opisthorchiasis patients who had no signs of biliary obstruction. The fecal egg excretion was consistent and correlated with the worm burden. Although there was no definite association between clinical signs and intensity of infection, mild hepatomegaly and thickened wall or dilatation of the gallbladder were found more commonly in heavily infected patients. Eosinophilia was observed more often than previous reports. Concomitant parasitic infections were found in 82% of the patients. After praziquantel treatment, egg counts increased greatly during the first few days then decreased to very low levels in 7 days.

Adolescent↗
PubMed1989

Ultrasonographic study of the biliary system in opisthorchiasis patients after treatment with praziquantel.

Ultrasonographic examination of the liver and biliary system using a portable ultrasound unit was performed in 1987 in 647 opisthorchiasis patients who had been treated with praziquantel during 1981 to 1986. Treatments was repeated annually in those reinfected. The reinfection rate was 53.9% in the first year and gradually declined. Ultrasonographic findings were normal in 80.6% of subjects. The most common abnormal finding was liver enlargement (14.8%), followed by dilatation of the gallbladder (3.5%), sludge formation (2.1%) and thickening of the wall of the gallbladder (1.0%). Gallstones were found in 7 cases (1.0%). Dilatation of intrahepatic bile ducts was detected in one subject (0.1%). The incidence of gallstones in treated patients was similar to that reported in a large necropsy series of the general population. Prospective studies will be needed to further investigation the association between opisthorchiasis, treatment and gallstone formation.

Adolescent↗
PubMed1989

Human pathology of Opisthorchis viverrini infection: a comparison of adults and children.

The pathology of human opisthorchiasis in 22 adults (20 to 68 years) and 7 children (7 to 15 years) at autopsy is described. The changes of the liver in adults and children are similar and are summarized as follows: Enlargement of the liver was a common finding. Pericholangitis was observed in most cases. The pathology was confined to the large and medium-sized bile ducts where the flukes inhabited. The small interlobular bile ducts had minimal or unremarkable changes. Dilatation of the bile ducts with hyperplasia, desquamation and proliferation of the bile duct epithelial cells, glandular formation and fibrous connective tissue infiltration of the walls were the most common features. The pathological changes were well established within 7 to 15 years. Dilatation of the gallbladder, chronic cholecystitis and carcinoma were found only in adults. Eight of ten cases were cholangiocarcinoma and two were hepatocellular carcinoma.

Adolescent↗
PubMed1988

Incidence of bacteremia in patients with opisthorchiasis during recurrent cholangitis.

A total of 257 haemocultures were performed in 50 patients with opisthorchiasis when they presented signs and symptoms of biliary tract infection. 19 patients showed positive haemoculture. There are no significant relationship between the age of the patient and the incidence of positive haemoculture. Septic shock occurred in 5 patients, one patient died. Out of 221 aerobic cultures, 14% were positive and of the 36 anaerobic cultures 11% were positive. The most common organism was Staphylococcus followed by Klebsiella and Bacillus spp. Anaerobic bacterias were Streptococcus spp. Clostridia spp. was not found in this study. Most organisms were sensitive to cefotaxime, cephalothin, kanamycin and chloramphenicol, and the least sensitive to ampicillin.

Adult↗