Biomedical subjects

N Thammapalerd

Publications and source records attributed to N Thammapalerd.

29 records · Page 2Linked to original sources

PubMed1989

Assessment of putative tests for protective immunity to falciparum malaria.

Sera from clinically immune individuals comprising 10 hospitalised patients (Group I), 30 persons residing in a malaria endemic area in Thailand (Group II) and 8 persons from a hyperendemic area in Ivory Coast (Group III) were tested by the parasite growth inhibition (PGI), indirect fluorescent antibody test of ring-infected erythrocyte surface antigen (RESA-IFA), urease-ELISA and Western blot. Paired sera from patients recovering from malaria (Group IV) as well as sera from blood donors were also tested. In the PGI test, sera were tested against three uncloned isolates of P. falciparum comprising SO, I4 and AE9 (PGI-SO, PGI-I4 and PGI-AE9 respectively). When growth inhibition of greater than or equal to 30% against any one of the three isolates was considered positive, the positive rate for the combined Groups I, II and III was 78.7%. Further analysis showed that the positive rates for PGI-SO, PGI-I4 and PGI-AE9 were 63.8%, 59.5% and 59.5% respectively and were not significantly different (p greater than 0.05). Comparison between PGI-SO, PGI-I4 and PGI-AE9 activities of Groups I, II and III sera showed no significant differences in any comparison groups except with PGI-AE9 in which Group III sera were more frequently positive than Group II sera (p = 0.004). Follow-up of PGI-SO and PGI-AE9 activities in Group IV patients showed mostly a decrease or no change in the activities of the convalescent sera taken 63 days later. RESA-IFA positive rate in the combined Groups I, II and III sera was 91.7%. There were no significant differences either in the seropositive rates or in the geometric mean antibody titers (GMT) between Groups I, II and III sera. Follow-up in Group IV patients showed no change in antibody titers in 64% of cases, decrease and increase in titers in 29% and 7% of cases respectively. The urease-ELISA seropositive rate in the combined Groups (I, II and III) was 89.5% which is not significantly different from that of RESA-IFA (p greater than 0.05). Comparison between individual Groups (I, II and III) likewise showed no significant differences in both GMT and seropositive rates. Follow-up in Group IV sera showed either no change or a decrease in antibody titers in 55.6% and 44.4% of cases respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

PubMed1988

Detection of antibodies against Opisthorchis viverrini in patients before and after treatment with praziquantel.

Levels of antibody in sera of 78 patients with opisthorchiasis, 30 patients with other liver diseases, 10 patients with schistosomiasis and 30 healthy individuals were compared using three serodiagnostic tests, namely indirect haemagglutination (IHA), enzyme-linked immunosorbent assay (ELISA) and lectin immuno test (LIT). The geometric mean reciprocal titer in sera of opisthorchiasis patients was significantly higher than patients with other diseases, patients with schistosomiasis and healthy individuals (p less than 0.00001). After treatment with praziquantel, the antibody titers were decreased and became lowest 120 days after treatment. A statistically significant decrease from the pre-treatment sample was observed only at 120 days after infection and not earlier and only with ELISA (p = 0.03) and not with IHA and LIT (p greater than 0.05). Even with ELISA, significant decrease in antibody titer was apparent only when the pre-treatment sera had high enough antibody titer. ELISA was therefore better than the other two tests for the assessment of cure provided that the titer of pre-treatment sera was high.

Animals↗

PubMed1987

Immunoprecipitating antibodies against blood stage antigens of Plasmodium falciparum in cerebral and non-cerebral malaria patients.

Immunoprecipitating antibodies were determined in paired sera of 31 patients with cerebral malaria (CM), of whom 14 had complicated cerebral malaria (CCM) and 17 had uncomplicated cerebral malaria (UCCM), 15 single specimens of patients with acute uncomplicated (AM) malaria taken on the day of admission and 8 healthy controls. All but one patient were admitted within the first three days of the onset of fever. More than 20 precipitating bands were observed, of which the predominating molecules were the Mr greater than 200, 180, 157, 135, 130, 115, 103, 96, 91, 73, 71, 61, 49, 45, 43, 41 and 14.3 Kd. In general, there were no significant differences in the positive rates among the AM, CCM and UCCM patients except for the pf135 Kd molecule which was more frequently reactive in UCCM patients than the AM and CCM patients. If immunological naiveness in term of protective immunity is the feature in CM patients, the immunoprecipitation test used is inadequate to demonstrate the fundamental differences in immune responses between CM and AM patients.

Animals↗

PubMed1986

A comparative study of four methods for detecting antibody in asymptomatic giardiasis.

Four immunological methods for diagnosis of giardiasis comprising complement fixation (CF) test, indirect hemagglutination (IHA) test, enzyme-linked immuno sorbent assay (ELISA) and lectin immuno test (LIT) were studied. Fifty sera from asymptomatic giardiasis patients, 40 from patients with other diseases and 50 from healthy controls were evaluated. The seropositive rates in asymptomatic giardiasis were 36% for CF, 58% for LIT, 30% for IHA and 72% for ELISA. The seropositive rates in patients with other diseases were 22.5% for CF, 52.5% for LIT, 12.5% for IHA and 67.5% for ELISA. The results suggest that the test of choice for giardiasis was CF with 88% specificity, nevertheless this test showed low sensitivity (36%). Other two tests, ELISA and LIT were more sensitive than CF with percent sensitivity of 72 and 58 respectively, but these two tests had severe disadvantages in being less specific with percentage specificity of 48 and 60 respectively.

Antibodies↗

PubMed1982

Mouse IgE response to an allergen from Entamoeba histolytica.

Attempts were made to demonstrate the presence of allergenic components in an extract of axenically cultured Entamoeba histolytica (HK 9). Various strains of mice were immunized i.p. with a low dose of the extract mixed with Al(OH)3 and boosted with the same mixture 4 wk later. A high titer of IgE antibody response was demonstrated in BALB/c, DBA/2 (H-2d), CBA (H-2k), and SWM strains but not in C3H/He (H-2k) strain. The extract was fractionated by gel filtration with Sephadex G-200 and then by DEAE-cellulose chromatography with a gradient buffer with progressive increase in molarity. Fractions having the strongest activity to stimulate the IgE antibody response in the mouse were subjected to SDS polyacrylamide gel electrophoresis. From the results of gel filtration and polyacrylamide gel electrophoresis, the molecular weight on the partially purified allergen was estimated to be 25,000 to 27,000 daltons.

Allergens↗

PubMed1981

Cellulose acetate membrane precipitin (CAP)test in amoebiasis using antigens from four different strains of Entamoeba histolytica.

A simple cellulose acetate membrane precipitin (CAP) test was evaluated against immunoelectrophoresis (IEP) test using saline extract from 4 different strains (HK-9, HT-10, HT-12 and HT-31) of axenically grown Entamoeba histolytica as the antigens. All 81 sera from patients with amoebic liver abscess were positive in the IEP against the antigens from all 4 strains. With the CAP test the number positive against antigens from HK-9, HT-10, HT-12 and HT-31 were 79,77,79 and 71 respectively Sera from 100 blood donors were negative by both IEP and CAP tests against antigens from all 4 strains. Comparison between the number of precipitating bands demonstrated by either IEP or CAP test showed that strain HT-12 was the best source of antigen in exhibiting significantly more number of precipitating bands, strain HT-31 was the poorest. The strain HT-10 was comparatively superior to strain HT-31 in the CAP test whereas in the IEP test strain HK-9 and HT-31 were both inferior to strain HT-10.

Antigens, Viral↗

PubMed1981

Leucocyte migration agarose test to study cell-mediated immunity in amoebiasis.

The leucocyte migration agarose test (LMAT) was used to measure quantitatively the magnitude of cell-mediated immunity (CMI) in 35 patients with amoebic liver abscess and 22 healthy controls. LMAT was positive in 65.7% and 85.7% of patients with amoebiasis in the presence of 200 microgram and 400 microgram of the amoeba extract respectively, whereas the test in all 22 healthy controls was negative. Time course studies showed that within 10 days after the onset of clinical illness, only 1 of 4 patients was positive. Thereafter the percentage positivity was raised, especially when 400 microgram antigen was used. Maximum CMI response was apparent between 31-60 days after the onset of clinical illness. The indirect haemagglutination (IHA) test showed that all patients and 5 of 22 healthy controls were positive. These was no correlation between IHA titers and the magnitude of LMAT reaction.

Antibody Formation↗

PubMed1981

Humoral immune response of cats to Paragonimus infection.

The time course of humoral immune response to Paragonimus siamensis was studied in 10 cats experimentally infected with either 30 or 60 matacercariae and the antibody produced was detected by enzyme linked immunosorbent assay (ELISA), complement fixation test (CFT), and immunoelectrophoresis (IEP) test. With ELISA and CFT, antibodies was detected as early as 2nd week after infection and the cats remained positive throughout the 12 week period of observation. In contrast, the IEP test was persistently negative. With respect to sensitivity, both ELISA and CFT are equally sensitive but the mean ELISA titer was consistently higher than that of CFT. THe magnitude of the antibody response appeared to be related to duration of the infection but not to the infective dose and the number of worms recovered. There was variability in titers among cats infected with equal numbers of metacercariae. The tests can not be used for differential diagnosis of infections by P. siamensis and P. heterotremus because of the cross-reaction. Such cross-reaction did not not occur against unrelated parasites including hookworm. Toxocara cati and Spirometra mansoni.

Animals↗

PubMed1980

Purification of the antigen specific for amoebiasis.

Two methods used for the purification of specific antigen for amoebiasis were affinity chromatography and agarose gel electrophoresis. The IgG fraction of the serum from a patient with amoebic liver abscess showing a specific band in the IEP test was coupled to CNBr-activated Sepharose 4B. After passage through the immunoadsorbent column of the crude or partially purified extract of Entamoeba histolytica, followed by acid dissociation, specific antigen was obtained. This antigen gave only one band in the IEP test against the serum which gave multiple bands upon testing with the crude antigen. With the agarose gel electrophoresis, fraction 2 from the slit was found to contain specific antigen. Rabbits immunized with the excised agarose strip of this fraction produced antibodies giving 2 precipitating bands in the IEP test, one of which was specific for amoebiasis.

Amebiasis↗

PubMed1977

Total serum IgE level in patients with amoebic liver abscess and other parasitic infections.

Total serum IgE level was determined by the radioactive single radial diffusion technique in blood donors, nurse-aid students with the stool positive and negative for parasites, and in patients with helminthic infections. A geometric mean of 445.1 IU/ml in the sera from blood donors was found. Patients with helminthic infections had significantly higher levels than the blood donors and the nurse-aid students with the stool negative for parasites. Intestinal protozoal infections did not cause an increase in IgE level.

Helminthiasis↗

PubMedDate not supplied

Enzyme-linked immunosorbent assay based on monoclonal and polyclonal antibodies for the detection of Entamoeba histolytica antigens in faecal specimens.

A murine monoclonal antibody (MAb) (Eh208C2-2) raised against crude lysate of the pathogenic HM-1:IMSS strain of Entamoeba histolytica was used in an enzyme-linked immunosorbent assay for the detection of E. histolytica antigens in faecal specimens. The detection limit of the assay was 110 and 280 amoebae/ml of the HM-1:IMSS and HK-9 strains in phosphate-buffered saline, respectively. The assay was applied to single stool samples from 3 groups of individuals comprising 40 patients whose stools were positive for E. histolytica trophozoites and/or cysts (group I), 48 patients whose stools were negative for E. histolytica but positive for other parasites (group II), and 36 parasitologically-negative healthy controls (group III). Positivity rates of 77.5%, 2.1% and 2.7% were found in samples from groups I, II and III respectively. Specificity, positive and negative predictive values, and efficiency of the assay were 97.6%, 93.9%, 90.1% and 91.1% respectively. When group I samples were further divided into a trophozoite-positive subgroup IA (13 samples) and a cyst-positive subgroup IB (27 samples), the positive rates were 100% and 66.7%, respectively (P < 0.025).

Animals↗