Showing papers by "Chung-Ang University published in 1983"

Allelopathic effects ofPinus densiflora on undergrowth of red pine forest.

Abstract: Correlation between the distributional frequency of undergrowth species of red pine forest and their germination and growth effected by pine extracts and leachates was found. It was made clear by germination and growth tests that pine toxic substances inhibit the germination and growth of low frequency species more than high frequency species in a red pine forest and that these substances are contained in descending concentration in fresh and fallen leaves, roots, pine forest soil, and pine rain. The concentration of pine toxic substances in extracts or leachates was affected by extracting or leaching within a given period of time, requiring a few hours for extracts or a few days for leachates. The amount of dry weight inhibition of the undergrowth treated by pine leachates was expressed as a growth inhibition index (GII) for the comparison of tolerance in various species. GII is a relative value (%) of the test groups against the control and it is an exponential function of the amount of pine toxic substances affecting the dry weight of the undergrowth. The substances were analyzed by paper and gas chromatography. Benzoic acid and 11 phenolic acids were identifed by gas chromatography. Benzoic acid was considered to be a key factor of allelopathy in the red pine forest.

A Study On Intestinal Lesions Of Experimentally Reinfected Dogs With Metagonimus Yokogawai.

Abstract: The intestinal lesions were studied in dog metagonimiasis by reinfection. The metacercariae of M. yokogawai were collected from naturally infected sweetfish. A total of twenty dogs were divided into three groups; control, primary infection and reinfection groups. The 18 dogs were infected with 10,000 metacercariae; the 5 dogs in primary infection group were killed at the 5 days in 1 week, 4 weeks, 6 weeks after the infection. The remaining 13 dogs were kept for nine weeks, and challenged again with 5,000 metacercaricae. The reinfected dogs were killed at the 1 day, 3 days, 5 days and 1 week, 2 weeks, 4 weeks, 6 weeks, 8 weeks respectively. The chronologic changes of the intestinal lesions in both groups, the worm recovery rate, and distribution patten were examined by gross observation, light and scanning electron microscopies. The results were summarized as follows: 1. Worm recovery rate in primary infection group ranged from 19.8% to 37.8%. The rates were 6.3% to 16.3% in reinfected dogs within 5 dats. And the ratio of young worms collected to old ones was 1:1.83. In primary infection group, the collected worms were distributed in upper portion of the small intestine, while the distribution of worms shifted down to the lower portion of the small intestine in reinfection group. 2. In primary infection group, gross pathologic findings of intestinal mucosa began to appear in the 5th day and the 1st week after infection. The changes were effacement of transverse folds, watery or serous intestinal content, and enlargement of Peyer's patches as well as mesenteric lymph nodes. After the 4 week of infection, these findings returned to normal. In the reinfection group, these findings did occur again, but were lighter in degree when compared with primary infection group in early phase of infection. Again the gross changes returned to normal in two weeks which resolved earlier than in promary infection groups. 3, By histopathologic observations, mucosal changes such as blunted, adhered villi with hyperplasia of crypt epithelium, stromal changes, edema, and inflammatory cell infiltration were observed. These regressed mucosal changes were returned to almost normal, except for inflammatory cell infiltration. The reinfected dogs showed less severe lesions of the small intestine, with shorter period of the changes especially in aspect of villous changes. 4. By the scanning electron microscopy, the histopathological findings of villi lesions were also confirmed. From the above results, it was inferred that the so-called spontaneous and/or self cure phenomena were of negligible importance in metagonimiasis in dogs. In the chronologic observations of pathologic process in intestine, it was also suggested that the host immunity tend to recover the intestinal integrity. And early invasion of young worms to the Lieberkuhn's crypt was considered as the primary cause of lesions of villi.

[An Epidemiological Study Of Human Paragonimiasis By Means Of Micro-ELISA]

Abstract: As epidemiological parameters of human paragonimiasis, the positive rates of intradermal test and the sputum/stool examination have long been employed in population surveys. However, both the specificity of the intradermal test and the sensitivity of sputum/stool examination have been gradually declined as the endemicity was lowered; thus the gap between above two parameters widened. In such context, the development of a new epidemiological parameter or tool which makes it possible to accurately discriminate the active paragonimiasis cases was necessary. In the present study, the detection rate of Paragonimus-specific IgG antibody by micro-ELISA was evaluated as an indicator of epidemiologic status of human paragonimiasis in a population. A total of 4,285 students and inhabitants living in Bukpyeong Myeon and Bukil Myeon, Haenam Gun, Jeonlanam Do was surveyed in October 1983 by intradermal test first. Out of them, 244 case (5.7 %) were found positively reacted to VBS antigen of P. wetermani. Out of 168 positive reactors, 7 cases (4.2 %) were egg positive either by two times of sputum examination or by one stool examination. That indicated that only 0.16 % of total surveyed were confirmed as active paragonimiasis by egg detection. When sera collected from 239 positive reactors of intradermal test were tested by micro-ELISA for their specific IgG antibody, 40 cases (16.7 %) were found to be positive. All of 7 eggs positive cases were again positive for specific IgG antibody. Among remaining 232 intradermal test positive cases, 33 cases were positive for IgG antibody. In contrast to those, none of 42 positive reactors to intradermal test for Clonorchis and of 128 intradermal test negative cases showed positive for Paragonimus- specific IgG antibody. The rate of specific IgG antibody as detected by micro-ELISA appeared to be increased with the wheal size of the intradermal test. When the wheal size was over 13 mm in diameter, about 50 % of them were positive for specific IgG antibody. Thirty-one specific antibody positive cases were clinically evaluated by laboratory examinations (repeated sputum examination, peripheral eosinophil count and chest roentgenogram) and by history taking. Out of them 24 cases were associated with one or more positive laboratory findings; thus considered as active paragonimiasis cases. Out of 7 lab. finding-free cases 3 revealed past history of typical paragonimiasis symptoms, suggesting that they were in chronic or in convalescent stages. The remaining 4 cases were considered as either mild or ectopic infection cases; the possibility of cross-reaction with other helminthiases could not be ruled out. From the above results, it was inferred that the detection of Paragonimus-specific IgG antibogy by micro-ELISA was very much helpful in detecting the active cases as well as in proper evaluation of the endemicity of human paragonimiasis in a population. The convenience of mass handling of sera in micro-ELISA was considered another superiority as an epidemiologic tool.

On The Applicability Of Partially Purified Antigenic Preparations Of Paragonimus Westermani

Abstract: In order to obtain more specific antigenic preparation for the diagnosis of human paragonimasis, crude saline extract of whole worm (=PwWWE), secretory-excretory components (PwSEC) and secretion-excretion-free somatic extract (PwSM) of 12 week-old Paragonimus westermani were filtrated through Sephadex G-200 gel column. The adult Paragonimus worms were obtained from experimentally infected dogs. A total of 11 antigenic solutions was lyophilized or diluted to adjust protein content of 1 mg/ml. To evaluate the antigenicity of crude antigens and fractions, micro-ELISA was done with the sera from P. westermani infected cases, C. sinensis infected cases and non-infected control cases to detect Paragonimus specific IgG antibody. The results were as follows: When the PwWWE was filtrated through Sephadex G-200 gel, it was separated into three fractions; PwWWE Fr. 1, PwWWE Fr. 2 and PwWWE Fr. 3. The percentage of protein content was 28.0 %, 21.6 % and 50.4 % respectively. The PwSM was also separated into three fractions; PwSM Fr. 1, PwSM Fr. 2, PwSM Fr. 3 and their percentage of protein content was 41.3 %, 38.6 % and 20.1 %. However, the PwSEC showed different fractionation pattern; i.e. fraction 1 (=PwSEC Fr. 1) and 3 (PwSEC Fr. 3) without fraction 2. The percentage of protein content was 14.0 % in PwSEC Fr. 1 and 86.0 % in PwSEC Fr. 3. When the antigenicity of each Paragonimus crude antigen and fractionated antigen was evaluated for specific IgG antibody by micro-ELISA in 10 human paragonimiasis sera, PwSEC Fr. 1 was the most potent antigen showing the mean absorbance 1.98. The PwWWE Fr. 1, PwSEC, PwWWE were next to that; their mean absorbance were 1.72, 1.38 and 0.83, respectively. The antigenicity of fractions 2 and 3 was much weaker in binding specific IgG antibody. When the antigens were reacted in micro-ELISA with 10 human clonorchiasis sera, most antigens showed weak reactivity. Each fraction 1 of crude antigens reacted higher than other fractions or crude antigens; the mean absorbance was 0.17 in fraction 1, but in others the absorbances were about 0.06. With non-infected control sera, the result of micro-ELISA revealed almost same pattern with those of the clonorchiasis sera. From the above results, it became apparent that PwWWE Fr. 1, especially PwSEC Fr. 1 was the most potent antigen reacted with Paragonimus specifc IgG antibody.

Lipofuscin Pigment In Adult Clonorchis Sinensis.

Abstract: Adult Clonorchis sinensis from infected human cases may have black pigment in their parenchyme. In present paper, the nature of the pigment was investigated. The pigment distributed in cytoplasm of parenchymal cells of the worms. Histochemically the pigment was positive by periodic acid-Schiff, Ziehl-Neelsen, and lipofuscin stainings. The pigment particle contained many, various sized membrane structure as well as electron dense granules when observed by electron microscopy. Staining characteristics of the black pigment, together with electron microscopic findings, strongly indicated that the pigment was lipofuscin.

Aspartate And Alanine Aminotransferase In Fasciola Hepatica

Abstract: The activity and distribution of aspartate aminotransferase (EC 2.6.1.1) and alanine aminotransferase (EC 2.6.1.2) in adult Fasciola hepatica have been studied. Fasciola hepatica was fractionated by differential centrifugation into nuclear, mitochondrial and cytosolic fractions. The activity of GOT and GPT was measured by the method of Reitman and Frankel. Isozyme patterns of those enzyme were also examined by DEAE-cellulose column chromatography. The results obtained were as follows: 1. The activity of aspartate and alanine aminotransferase was about 0.55 unit and 0.92 unit per 1 g of Fasciola hepatica, respectively. 2. The activity of those enzymes was relatively low compared with those in mammalian tissues. 3. The distribution of aspartate aminotransferase in the subcellular organelles showed that 71 % of the activity was in cytosolic, 24 % in mitochondrial and 5 % was in nuclear fraction. 4. About 22 % of the total alanine aminotransferase activity was found in the mitochondrial fraction, about 66 percent in the cytosolic fraction. 5. Aspartate aminotransferase from cytosolic fraction was separated into two types of isozymes, whereas alanine aminotransferase from cytosolic fraction gave only one active peak on DEAE-cellulose column chromatography.

Purification And Properties Of Branched Chain Amino Acid Aminotransferase From Fasciola Hepatica

Abstract: The distribution and properties of branched chain amino acid aminotransferase(EC 2.6.1.42) was investigated in adult Fasciola hepatica. Fasciola hepatica was fractionated by differential centrifugation into nuclear, mitochondrial and cytosolic fractions. The activity of branched chain amino acid aminotransferase was measured by the method of Ichihara and Koyama (1966). Isozyme patterns of this enzyme was also examined by DEAE-cellulose column chromatography. The results obtained were as follows: 1. The activity in homogenate was found to be 12.69 units/g wet tissue. The activity of this enzyme was relatively high compared with those in rat tissues. 2. The distribution of branched chain amino acid aminotransferase in the subcellular organelles showed that 87.8 % of the activity was in cytosolic, 10.9 % in mitochondrial and 1.3 % was in nuclear fraction. 3. Cytosolic fraction of Fasciola hepatica contained Enzyme I, but not Enzyme II and III, of branched chain amino acid aminotransferase. Enzyme I was eluted by 50 mM phosphate buffer from DEAE-cellulose column and catalyzed the transamination of all three branched chain amino acids. 4. The Enzyme I was purified about 22-folds increase in specific activity after chromatography on DEAE-cellulose. 5. The best substrate among three amino acids (leucine, isoleucine and valine) was L-isoleucine. 6. The optimal temperature of Enzyme I was 45 degrees C and the optimal pH was 8.2. 7. The Km value for leucine of Enzyme I was 4.17 mM. 8. The Km values for alpha-ketoglutarate and pyridoxal phosphate of Enzyme I were 0.41 mM and 4.76 x 10(-3) mM, respectively.