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Biomedical subjects

S Tharavanij

Publications and source records attributed to S Tharavanij.

88 records · Page 5Linked to original sources
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

Prevalence of genital herpesvirus infection in Thai women.

Specimens from uterine cervices were collected from 157 women patients from a Venereal Disease Clinic for isolation of Herpesvirus hominis type 2. None of these women had detectable herpetic lesions. Virus was isolated from 14 cases, 6 of whom also had gonorrhoea. These results indicated that a large number of women are shedding the virus asymptomatically. The sera from these patients as well as sera from 101 healthy controls were subjected to serological tests for herpesvirus antibody using the indirect haemagglutination (IHA) test and the enzyme linked immunosorbent assay (ELISA). It was found that both IHA titer and ELISA value of the sera from the patients were significantly higher than those of the control sera. Positive correlation between IHA and ELISA value was also found. Likewise was the demonstration of positive correlation between the positive virus isolation and the positive serological tests.

Adolescent↗
PubMed1980

Susceptibility of Salmonella typhi to chloramphenicol, ampicillin and cotrimoxazole.

Salmonella typhi isolated from the patients admitted to the Hospital for Tropical Diseases, Bangkok, were tested by the tube dilution method and the disc diffusion method against chloramphenicol, ampicillin and cotrimoxazole. Forty-five percent of the S.typhi were resistant to chloramphenicol (MIC greater than or equal to 50 microgram/ml) while 5% were resistant to ampicillin (MIC greater than or equal to 12.5 microgram/ml). Only 1% of the S. typhi was found to be resistant to cotrimoxazole (MIC greater than or equal to 168 microgram of trimethoprim + sulfamethoxazole per ml.) Based on these results, the drug of choice for typhoid fever would be cotrimoxazole, especially when drug sensitivity test is not immediately available.

Ampicillin↗
PubMed1980

Prevalence of enterotoxigenic Escherichia coli in patients with diarrhoea in Bangkok.

Enterotoxigenic Escherichia coli (ETEC) were recovered from 17 of 82 patients (20.7%) with diarrhoea admitted to Bamrajnaradura Hospital. Six patients (7.3%) were infected with LT + ETEC, 6 patients (7.3%) with ST + ETEC, 2 patients (2.4%) with LT + ST + ETEC and 3 patients with mixed ETEC infection, two of them had LT + ST + and LT + and one had LT + and ST + ETEC infections. There was no significant differences between the age group and the positive isolation of ETEC. Only 33 of 63 isolates could be typed. Two of 4 patients with LT + ST + ETEC had 078 serotype. There was no correlation between enteroxigencity and enteropathogenicity as determined by the antisera used. Antibiotic sensitivity testing showed that 51.6% of ETEC isolates were resistant to ampicillin, chloramphenicol, streptomycin and tetracycline, and all ETEC were sensitive to gentamicin and cotrimoxazole.

Adolescent↗
PubMed1980

Immunological study of typhoid fever in man: humoral immune response.

Widal and indirect haemagglutination test were used to study the humoral immune response of 45 patients with typhoid fever. The Widal and IHA tests were positive in 41 (91.1%) and 42 (93.3%) of patients with typhoid fever after the second week of illness. Comparison between the Widal and IHA test showed that the latter was more sensitive as assessed by Wilcoxon matched-pairs signed-ranks test (p less than 0.01). The anti-LPS antibody belongs to all three classes of immunoglobulins namely IgG, IgM and IgA with the confinement mostly to IgG and IgM. It was found that the level of haemagglutinating enhancement activity was strongest in IgG class. The low level of anti LPS-antibody was found in healthy persons with the pattern of immunoglobulin class of antibody similar to that in patients with typhoid fever.

Adolescent↗
PubMed1979

Tachypleus lysate test for endotoxin in patients with Gram negative bacterial infections.

Amoebocyte lysate from the horseshoe crabs (Tachypleus gigas) which abounds in the Gulf of Thailand was used to detect endotoxin in patients with Gram-negative bacteremia, in patients with Gram-positive bacterial infections as well as in the control. The Tachypleus lysate test (TLT) was positive in 94.4% of 36 patients with Gram-negative bacteremia before initiation of antibiotic therapy. Only 4% of 50 healthy individuals were positive and all 7 patients with Gram-positive bacterial infections were negative. The threshold sensitivity of TLT was 0.625 micrograms endotoxin per ml of the plasma. In comparison with the commercial Limulus lysate test (LLT), the TLT was slightly more sensitive in exhibiting higher grade of reaction, eventhough the threshold sensitivity was the same.

Endotoxins↗
PubMedDate not supplied

Diagnosis of Plasmodium vivax malaria using a specific deoxyribonucleic acid probe.

A deoxyribonucleic acid (DNA) probe which specifically distinguishes Plasmodium vivax from P. falciparum malaria has been derived from a P. vivax genomic DNA library. This probe, VPL101, consists of 3.2 kilobase pairs and does not hybridize with up to 6 micrograms of human or P. falciparum DNA. VPL101 contains at least two copies of a 205 base pair repeat sequence. The subcloned repeat probe, VPL101/5, reacted with 73 of 76 microscopically diagnosed P. vivax samples but not with any of 17 human DNA samples or any of 8 P. falciparum DNA samples from cultured parasites. It was possible to detect P. vivax in mixed infections in which only P. falciparum parasites were identifiable by microscopy. This P. vivax DNA probe provides a useful epidemiological tool for malaria control programmes.

Animals↗
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↗