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Biomedical subjects

E R Chen

Publications and source records attributed to E R Chen.

At least 55 records · Page 3Linked to original sources
PubMed1990

A survey of Ampullarium canaliculatus for natural infection of Angiostrongylus cantonensis in south Taiwan.

Ampullarium canaliculatus were collected monthly from the field in five areas in Pintung County and examined for larvae of Angiostrongylus cantonensis. Snails from one area showed the highest positive rate (30.8%) and the highest number (31) of larvae per snail. Snails were placed in four groups according to size. The positive rates in snails increased from 10.0 to 29.4% and the average number of larvae per snail increased from 11 to 40 as the size of snails increased from 1.0 to 4.0 cm height or more. In the seasonal fluctuation of snails in the field, positive snails could be examined every month; however, the positive rate in snails (28.2%) and the average number of larvae per snail (33) in the dry season (November to April) were significantly higher than those (15.2% and 23 respectively) in the rainy season (May to October). Ampullarium canaliculatus were confirmed naturally infected with A. cantonensis in this investigation so more attention should be paid to the snails to prevent the infection in humans.

Angiostrongylus↗
PubMed1990

[Survey of Enterobius vermicularis infection among school children in Tainan City].

A survey was conducted for enterobiasis, in six primary schools at Tainan city. The survey was conducted in 1986, involving 8,120 school children. The manner of testing, was two consecutive day, adhesive cellophane paper perianal swabs. The test resulted in general infection rate of 30.4%. The positive rates among those primary school children were significantly different (chi 2-test, p less than 0.001). The highest rate (40.3%), was in Shih-Men primary school and the lowest rate (18.7%) in Pao-Jeng primary school. Gender occurrence of enterobiasis was determined by making a statistic analysis between sex. We found significantly higher occurrence in males (32.4%) as opposed to females (28.3%) (chi 2-test, p less than 0.001). The infection rates were also significantly different by grade (chi 2-test, p less than 0.001). The highest rate was found in the lower grades (35.3%), the next in the middle grades (32.4%), and the lowest in the higher grades (21.6%). A questionnaire demonstrated that the family status and personal hygiene are the most important factors in transmission of pinworm infection, among the group surveyed. Moreover, the educational levels, occupations of parents, and facilities of bathrooms, (between both primary schools) were also found significantly associated with the transmission of pinworm infection. Therefore, we believe that these factors play a role in transmission of pinworm infection among school children.

Age Factors↗
PubMed1989

Seroepidemiology of hepatitis B virus, hepatitis D virus, and human immunodeficiency virus infections among parenteral drug abusers in southern Taiwan.

A total of 390 parenteral drug abusers (PDAs) at the Kaohsiung Municipal Narcotics Abstention Institute were examined for markers of hepatitis B virus (HBV), hepatitis D virus (HDV), and human immunodeficiency virus (HIV). All sera were tested for hepatitis B surface antigen (HBsAg), surface antibody (anti-HBs), and core antibody (anti-HBc) by radioimmunoassay (RIA) and for antibody to HIV (anti-HIV) by enzyme-linked immunosorbent assay (ELISA). Hepatitis B e antigen (HBeAg) and antibody to HDV (anti-HDV) were also tested for HBsAg-positive serum samples. Although the HBsAg-positive rate (22.1%) among PDAs was similar to that of the general population in southern Taiwan, the HBV infection rate (99.2%) and the anti-HDV-positive rate (78.5%) among HBsAg-positive subjects were significantly higher than those of the general population in southern Taiwan (P less than 0.0001). None of the PDAs studied were positive for anti-HIV. The levels of serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) among PDAs were significantly higher than those of the general population in southern Taiwan (P less than 0.0001). The more frequent the institutionalisation, the higher the infection rates with HBV and HDV and elevated levels of SGOT and SGPT. Horizontal transmission through parenteral drug abuse may be considered a possible reason for the significantly higher rates of HBV and HDV among parenteral drug abusers.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Acquired immunity in rats against Angiostrongylus cantonensis infection.

Acquired immunity against Angiostrongylus cantonensis was induced by immunizing rats with somatic antigens from fifth-stage larvae and adult worms and live third-stage larvae. Rats immunized twice had significantly fewer worms than rats immunized three times. Fewer worms were recovered from rats immunized with 200 live third-stage larvae than from any other groups. Rats immunized with somatic antigens had higher enzyme-linked immunosorbent assay (ELISA) antibody levels than rats immunized with live larvae. Rats immunized with live third-stage larvae of Angiostrongylus cantonensis were more strongly protected against challenge infections (62-92%) than rats immunized with antigens extracted from fifth-stage larvae (0-30%) and adult worms (11-24%).

Angiostrongylus↗
PubMed1989

Study on the immunity to measles in pre-school children.

One hundred and ninety-seven pre-school children, composed of 109 boys and 88 girls, who resided in a rural community in southern Taiwan were studied. The age range was from 6 months to 5 years old (y/o) and vaccination coverage was determined by home visits and the vaccination records of the health station. Immunological status was tested by an enzyme-linked immunosorbent assay (ELISA) to determine the positive rate of measles-specific IgG. The results were as follows: 1, vaccination coverage in the studied sample was 87.9%; 2, the educational level of fathers had a significant influence on vaccination; 3, the positive rate of measles antibody in the vaccinated children was 73.9%; 4, the measles immunity level in the studied sample was 67.8%; and 5, the positive rate of measles antibody, as analyzed by a stratified test, indicated that vaccination age, the current age, and the number of siblings were the significant influence factors. When adjusted to the above variables, it was found that the number of siblings was the significant influencing factor.

Age Factors↗
PubMed1989

The ultrasound survey of gallstone diseases of patients infected with Clonorchis sinensis in southern Taiwan.

Ultrasonography was used to evaluate the relationship between the gallstone diseases and infection with Clonorchis sinensis. One thousand and ninety-one Hakkanese in southern Taiwan were examined in the past 2 years. Among the 947 cases infected with clonorchiasis, 89 cases were found to have gallstone diseases, which included gallbladder stones (85 cases), common bile duct stones (three cases) and one case of intrahepatic duct stone, indicating a prevalence of 8.97, 0.32 and 0.11% respectively. The overall prevalence of gallstones in the infected group was 9.39%. In the other 144 cases without clonorchiasis infection, eight patients were found to have gallstone disease, which included gallbladder stone (six cases) and intrahepatic duct stone (two cases), indicating an incidence of gallstone of 4.16 and 1.39% respectively. The overall prevalence of gallstones in the non-infected group was 5.56%. A comparison between the infected and non-infected groups was made and showed no significant relationship between gallstone disease and clonorchiasis.

Adolescent↗
PubMed1989

Counterimmunoelectrophoresis test on human Clonorchis sinensis infection.

A counterimmunoelectrophoresis test was used to detect antibodies against the adult worm antigen of Clonorchis sinensis in sera from 70 clonorchiasis patients, 20 uninfected healthy persons and 7 patients infected with other helminths. A constant voltage of 10 V/cm and a running time of 30 minutes was chosen in carrying out detection. Antibody titers of 1, 1:2 and 1:4 were obtained from 35, 21 and 14 clonorchiasis patients, respectively. Significant correlation was observed between worm burden in patients and antibody titer, the higher the antibody titer in patients, the more eggs per gram feces in their stool. Although cross reaction was observed with toxocariasis and angiostrongyliasis in this study, high (100%) sensitivity made it possible to screen the subjects in endemic areas to shorten the survey period.

Animals↗
PubMed1989

Preparation of monoclonal antibody against Angiostrongylus cantonensis antigen.

Monoclonal antibodies (MAb) against A cantonensis were produced through fusion of immunised spleen cells from BALB/c mice with NS-1 myeloma cells at a ratio of 10:1. The successful fusion rate on the 3rd day of fusion was 90.1%. Ten MAb were characterised, six of which were IgG1 and the remaining four were IgG2a, IgG2b, IgM and IgA respectively. Among 6 IgG1 MAb, four were A. cantonensis-specific, of which three reacted to adult worm antigen only and one reacted to both adult worm and juvenile worm antigens. Two other IgG1 MAb showed cross-reaction with other helminthic antigens of Toxocara canis. Ascaris suum. Paragonimus westermani, Dirofilaria immitis, Anisakis Spp, Gnatostoma Spinigerum and Clonorchis sinensis.

Angiostrongylus↗
PubMed1989

[Experimental control study of fasciolopsiasis in Taiwan].

This study was conducted from March 1985 to September 1987 among the pupils of Chung-Ying Primary School of Hsia-Ying township in Tainan Country, Southern Taiwan. Health education revealed the preferred control method against Fasciolopsis infection in this study. The education method included lectures, demonstrations of parasites and home visits at regular intervals. The subjects included the staff and children of the school and all family members. At the same time, the children infected with Fasciolopsis were treated with praziquantel in June, 1986. Fecal material of the all primary school children of Hsia-Ying township was examined with the antiformin-ether concentration method. One year before control the positive rate of Fasciolopsis was 25.1%. One year after control in March 1986, it was decreased to 9.5%. Two and a half years after control in September 1987, it was farther brought down to 1.0%. The x2-test of positive rate showed statistically different. Health education with medication is recommended for the control of fasciolopsiasis.

Animals↗
PubMed1988

Orosomucoid 1 and orosomucoid 2 types in the Taiwanese and Japanese: evidence for five new orosomucoid variants.

The genetic polymorphisms of orosomucoid, ORM1 and ORM2, were analyzed by isoelectric focusing on polyacrylamide gels and subsequent immunoprinting. Sera from 600 unrelated individuals in Taiwan and Japan were examined. Five new alleles, designated ORM1*7, ORM1*8, ORM1*4.2, ORM2*8 and ORM2*10, were observed together with common and rare alleles that have been found in the Japanese and the Filipinos. As compared with the Japanese, the Taiwanese have a higher frequency of ORM1*1, and a significantly lower frequency of ORM1*2.1.

Alleles↗
PubMed1988

Seroepidemiological studies on hepatitis B and D viruses infection among five ethnic groups in southern Taiwan.

In order to compare the prevalence of hepatitis B virus (HBV) and hepatitis D virus (HDV) infection among five ethnic groups in Pingtung County of southern Taiwan, a total of 240 serum samples were collected from September to October, 1985, from the following five ethnic groups: Taiwanese, Hakka, Mainland Chinese, aboriginal Paiwanese, and aboriginal Rukaiese. Ages of subjects ranged from 5 to 69 years. All sera were tested for hepatitis B surface antigen (HBsAg), surface antibody (anti-HBs), and core antibody (anti-HBc) by radioimmunoassay (RIA). Hepatitis B e antigen (HBeAg) and antibody to hepatitis D antigen (anti-HDV) were also tested for those with HBsAg-positive sera. Results showed that 44.1% of all sera examined were negative for HBsAG but positive for both anti-HBs and anti-HBc; additionally, 24.6% were negative for both HBsAg and anti-HBs but positive for anti-HBc. Only 134 serum samples showed negative results for HBV markers, indicating an HBV infection rate of 88.8%. The anti-HDV positive rate was estimated to be 2.7% among HBsAg-positive subjects. The HBsAg-positive rates among Rukaiese, Paiwanese, Hakka, Taiwanese, and Mainland Chinese were 25.8, 22.5, 16.7, 12.9, and 10.0%, respectively; while the prevalence rates of HBV infection among the above five groups were 94.2, 94.6, 85.4, 87.5, and 82.5%, respectively. Differences in the HBsAg-positive rate and HBV infection rate among these ethnic groups were statistically significant. We conclude that people living in Pingtung County are more frequently infected with HBV when compared with inhabitants in northern Taiwan.

Adolescent↗
PubMed1988

Larvicidal effect of albendazole against Angiostrongylus cantonensis in mice.

Mice were infected with 50 third stage larvae of Angiostrongylus cantonensis and treated orally with albendazole (Zentel) in dosages of 5, 10, and 25 mg/kg/day begun 5, 10, or 15 days post-infection for 7, 14, or 21 consecutive days. The mice in each group were killed 3 days after cessation of treatment and the brains examined for parasites. Worms were recovered from the brains of all mice treated for 7 days, but recoveries from treated mice were significantly lower than from controls. Worm reduction was nearly 100% in mice treated for 14 days when treatment was initiated 5 and 10 days post-infection. Worms were found in the brain of mice treated for 14 days when treatment began at 15 and 20 days, but recovery rates were significantly lower than in controls. Similar results were obtained in animals treated for 21 days. Worm reduction rates were lower in animals given 5 mg/kg/day, but there was no significant difference in animals given higher dosages. Albendazole was effective in the treatment of A. cantonensis in mice when given within 15 days post-infection.

Albendazole↗