Search PubMed⌕ Search

Biomedical subjects

E R Chen

Publications and source records attributed to E R Chen.

At least 73 records · Page 4Linked to original sources
PubMed1985

[Immune responses in rabbits infected with Clonorchis sinensis].

Experimental rabbits were divided into single infection group, reinfection group and treatment group. Both eggs per gram of feces and serum antibody were determined periodically by antiformin-ether concentration method and ELISA technic, respectively. Two rabbits were observed 72 weeks and 76 weeks after infection in single infection occasion. Antibody elevated to the maximum during 8 and 14 weeks after infection, and then gradually decreased but still kept in detectable level till the termination of observation. EPG kept in lower intensity and no apparent variation during the period of observation. In periodically re-infected groups, both antibody and EPG increased after every occasion of re-infection. But in rabbits re-infection every month, its antibody were maintained in a high level and kept this level even at the 5th to 7th re-infection. In general, EPG increased less rapidly after several times re-infection. Stool examinations showed negative results, but in antibody variations were not concordant in rabbits after treatment. In un-infected rabbits, antibody kept in negative reaction during the course of observation.

Animals↗
PubMed1985

[Human clonorchiasis survey in Taiwan and its immunodiagnostic technics].

In a series of control study on human clonorchiasis, surveys had been carried out for four years. During the fourth year of study, immunodiagnosis was also tried. Skin test and stool examination were performed as a routine epidemiological survey in this study. The result of skin test revealed that 7 out of 738 primary school children and 2 out of 274 inhabitants in Tong-ho Township, Taitung County showed positive reaction. Four out of 500 children and none of 9 teachers tested from the primary school of Nan-hua Township, Hualien County were positive. For stool examinations, only one was found with Clonorchis eggs among 34 children from Nan-hua school, Hualien County, but none of 549 children from Tong-ho school, Taitung County was found with eggs. When stool examination was performed to those who had history of eating raw fresh water fish, positive cases increased in numbers, such as in Pingtung County, 19 out of 96 children and in Meinung Township of Kaohsiung County, 52 out of 86 children and 14 out of 19 teachers were shown positive for Clonorchis eggs. Immunodiagnosis by means of ELISA had been carried out in 72 sera of clonorchiasis patients and CFT, CIE in 30 sera. Results showed that ELISA detectable antibody titer was between 1,600 and 25,600, CFT, between 16 and 128 and CIE, under 4. In 8 sera of non-infected and 6 infected with various intestinal helminths, negative reactions were obtained from each technic.

Adult↗
PubMed1984

[A preliminary study on epidemiology of fasciolopsiasis in Tainan Hsien, south Taiwan].

Stool samples of 817 children (grades 4-6) from 3 primary schools, were collected and examined by the antiformin-ether concentration technique. Results showed no cases of Fasciolopsis were found from Liu-Ying primary school (Liu-Ying Hsiang), but infection rates of this fluke were found to be 13.0% and 3.5% for Ho-Chien and Tung-Hsing primary schools (Hsia-Ying Hsiang) respectively. Fourteen infected children had recent experience of eating raw water caltrops. On the other hand, only 8(21.6%) of 37 non-infected children had eaten raw water caltrops. Examination of intermediate host (Segmentina hemisphaerula, Trapa bispinosa) results showed that neither cercaria nor metacercaria was found. Intestines and stool samples from pigs were examined for worms and eggs of Fasciolopsis, the results were also negative.

Animals↗
PubMed1984

[Immunodiagnosis of human clonorchiasis by a micro-enzyme-linked immunosorbent assay].

A micro-enzyme-linked immunosorbent assay (ELISA) utilizing antigen from lyophilized Clonorchis sinensis adult worms extracted with triethanolamine buffered saline (TBS), veronal buffered saline (VBS) or phosphate buffered saline (PBS) were used to test 66, 31 and 9 sera from clonorchiasis patients, uninfected normal humen and patients with other parasitic infections, respectively. Four different combinations of incubation time between serum with antigen and serum with conjugate at either 37 degrees C or room temperature were tried. The combination of 6 hours and 16 hours reaction time processed at room temperature with shaking was chosen in this study because it revealed no pseudo-negative and cross reactions with high sensitivity, specificity and predictive value. There were no statistic difference among mean optical densities in micro-ELISA reactions of 66 sera (in 800 X dilution) from clonorchiasis patients with TBS, VBS or PBS antigen, respectively, but results obtained from TBS antigen seemed better than other two antigens. Good correlation was observed between the antibody titer or ELISA readings of sera form clonorchiasis patients and their worm burden expressed as eggs per gram of feces (EPG).

Antibodies↗
PubMed1983

[Immunodiagnosis of rabbit clonorchiasis by enzyme-linked immunosorbent assay].

Enzyme-linked immunosorbent assay (ELISA) was successfully applied to the immunodiagnosis of parasitic disease in 1974 by Engvall and Perlmann. In our study, this technic was used to test rabbits infected with Chonorchis sinensis metacercariae experimentally. The optimal conditions for the test were determined and summarized as follows: 1. The optimal concentration of VBS antigen was 4 micrograms/ml, showing the highest O.D. in the detection of ELISA test. 2. Four hundred-fold diluted alkaline phosphatase conjugated goat antirabbit IgG (Sigma company) was selected for the test. 3. One hundred times diluted sera of 15 pre-infected rabbits were tested by ELISA and their mean and standard deviation of O.D. was 0.083 +/- 0.004, which was used as the cut-off value for testing post-infected rabbits. Fifteen rabbits were divided into two groups. Group A and B rabbits were infected one hundred and three hundred metacercariae respectively. Sera and stools were collected from all rabbits before and after infection. In serum examination, antibody was detectable by ELISA test during seven and twenty-one and twenty-eight days after infection. Optical density of fifteen infected rabbits detected by ELISA was significantly higher than before infection. ELISA test was successfully applied to the immunodiagnosis of Clonorchis sinensis infected rabbits.

Animals↗