• Parasites, Hosts and Diseases
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• v.27 no.2
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• pp.87-100
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• 1989

Eimeria tenella, an intracellular protozoan parasite infecting the epithelial cells of the ceca of chickens, causes severe diarrhea and bleeding that can lead its host to death. It is of interest that 2. tenezla first penetrate into the mucosal intraepithelial Iymphocytes (IEL) before they parasitize crypt or villous epithelial cells. This in vitro study was undertaken to know whether the penetration of E. tenella into such a lymphoid cell is a beneficial step for the parasite survival and development. Three sequential experiments were performed. First, the in vitro established bovine kidney cell line, MDBK cells, were evaluated for use as host cells for E. tenella, through morphological observation. Second, the degree of parasite development and multiplication in MDBK cells was quantitatively assayed using radioisotope labelled uracil ($^3H-uracil$) . Third, the E. tenella sporozoites viability was assayed after preincubation of them with thicken spleen cells. E. tenella oocysts obtained from the ceca of the infected chickens were used for the source of the sporozoites. Spleen cells (I) obtained from normal chickens (FP strain) were preincubated with the sporozoites (T) at the E:T ratio of 100:1, 50:1 or 25:1 for 4 or 12 hours, and then the mixture was inoculated into the MDBK cell monolayer. Morphologically the infected MDBK cells revealed active schisogonic cycle of E. tenella in 3~4 days, which was characterized by the appearance of trophozoites, and immature and mature schizonts containing merogoites. The 3H-uracil uptake by E. tenella increased gradually in the MDBK cells, which made a plateau after 48~60 hours, and decreased thereafter. The uptake amount of $^3H-uracil$ depended not only upon the inoculum sixte of the sporozoites but also on the degree of time delay (preincubation; sporozoites only) from excystation to inoculation into MDBK cells. The 3H-uracil uptake became lower as the preincubation time was prolonged. In comparison, after preincubation of sporozoites with spleen cells for 4 or 12 hours, the 3H-uracil uptake was significantly increased compared with that of control group. From the results, it was inferred that, although the penetration of E. tenella sporozoites into the lymphoid cells such as IEL is not an essential step, it should be at least a beneficial one for the survival and development of sporozoites in the chicken intestine.

• Journal of Gastric Cancer
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• v.20 no.2
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• pp.139-151
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• 2020

Purpose: Globally, there is a high incidence of gastric cancer (GC). Leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) is reported to play a vital role in several human malignancies. However, there is limited understanding of the role of LETM1 in GC. This study aims to investigate the effects of LETM1 on proliferation, migration, and invasion of GC cells. Materials and Methods: The expression levels of LETM1 in the normal gastric mucosal epithelial cells (GES-1) and GC cells were analyzed by quantitative real-time polymerase chain reaction and western blotting. CCK-8, wound healing, and Transwell invasion assays were performed to evaluate the effect of LETM1 knockdown or overexpression on the proliferation, migration, and invasion of the GC cells, respectively. Additionally, the effect of LETM1 knockdown or overexpression on GC cell apoptosis was determined by flow cytometry. Furthermore, the effect of LETM1 knockdown or overexpression on the expression levels of PI3K/Akt signaling pathway-related proteins was evaluated by western blotting. Results: The GC cells exhibited markedly higher mRNA and protein expression levels of LETM1 than the GES-1 cells. Additionally, the knockdown of LETM1 remarkably suppressed the GC cell proliferation, migration, and invasion, and promoted the apoptosis of GC cells, which were reversed upon LETM1 overexpression. Furthermore, the western blotting analysis indicated that LETM1 facilitates GC progression via the PI3K/Akt signaling pathway. Conclusions: LETM1 acts as an oncogenic gene to promote GC cell proliferation, migration, and invasion via the PI3K/Akt signaling pathway. Therefore, LETM1 may be a potential target for GC diagnosis and treatment.

• Journal of Aquaculture
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• v.17 no.3
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• pp.215-220
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• 2004

Using light microscopy, the digestive tract of the parrot fish, Oplegnathus fasciatus was studied histologically. The tract consists of esophagus, stomach, intestine and fifty or sixty pyloric caecae. Each pyloric caecum is a blind sac of banana shape, and is originated from pyloric end of the stomach. The relative length of gut (RLG), that is length of digestive tract to standard length, is 1.78 (n=30). Esophagus has an undeveloped submucosa and a well developed muscularis mucosae. Its mucosa displays primary and secondary folds lined with a cuboidal or columnar epithelium and numerous acidic mucous secretory cells. The stomach has muscularis, which consists of longitudinal and circular muscular layers; its submucosa and muscularis mucosae are well developed. Only primary folds are present in the stomach. Microvilli are present in the epithelial layer. The stomach has a well-developed gastric gland and relatively more secretory granules. Mucosal epithelium of the pyloric caeca is composed of neutral mucous secretory cells and columnar epithelium with developed microvilli in the apical portion. Using the morphological and histological features, the intestine may be divided into anterior, mid and posterior parts. It has an advanced striated border and abundant acidic mucous secretory cells and some neutral mucous secretory cells. The mid intestine has more abundant acidic mucous secretory cells than the anterior and posterior parts. A thick longitudinal muscle is formed in the intestine and its thickness is progressively increased towards the posterior end.

• Journal of Microbiology
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• v.42 no.4
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• pp.255-266
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• 2004

Papillomaviruses infect a wide variety of animals, including humans. The human papillomavirus (HPV), in particular, is one of the most common causes of sexually transmitted disease. More than 200 types of HPV have been identified by DNA sequence data, and 85 HPV genotypes have been well char­acterized to date. HPV can infect the basal epithelial cells of the skin or inner tissue linings, and are, accordingly, categorized as either cutaneous or mucosal type. HPV is associated with a panoply of clin­ical conditions, ranging from innocuous lesions to cervical cancer. In the early 1980s, studies first reported a link between cervical cancer and genital HPV infection. Genital HPV infections are now rec­ognized to be a major risk factor in at least $95\%$ of cervical cancers. 30 different HPV genotypes have been identified as causative of sexually transmitted diseases, most of which induce lesions in the cervix, vagina, vulva, penis, and anus, as the result of sexual contact. There is also direct evidence demon­strating that at least four of these genotypes are prerequisite factors in cervical cancer. The main aim of this review was to evaluate the current literature regarding the pathovirology, diagnostics, vaccines, therapy, risk groups, and further therapeutic directions for HPV infections. In addition, we reviewed the current status of HPV infections in South Korean women, as evidenced by our data.

• Journal of Plant Biotechnology
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• v.36 no.3
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• pp.268-274
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• 2009

Porphyromonas gingivalis, the gram-negative anaerobic oral bacterium, initiates periodontal disease by binding to saliva-coated oral surface. The cholera toxin B subunit (CTB) genetically linked to FimA1 (1-200 aa) or FimA2 (201-337 aa) of the P. gingivalis fimbrial antigen were introduced into Solanum tuberosum cells by Agrobacterium tumefaciens-mediated transformation method. The integration of CTB-FimA1 or CTB-FimA2 fusion genes were confirmed in the chromosome of transformed leaves by genomic DNA PCR amplification method. Synthesis and assembly of the CTB-FimA fusion proteins into oligomeric structures with pentamer size was detected in transformed tuber extracts by immunoblot analysis. The binding activities of CTB-FimA fusion proteins to intestinal epithelial cell membrane receptors were confirmed by GM1-ganglioside enzyme-linked immunosorbent assay (GM1-ELISA). The ELISA showed that the expression levels of the CTB-FimA1 or CTB-FimA2 fusion proteins were 0.0019, 0.002% of the total soluble protein in transgenic tuber tissues, respectively The synthesis of CTB-FimA monomers and their assembly into biologically active oligomers in transformed potato tuber tissues demonstrates the feasibility of using edible plants for the production of enterocyte targeted fimbrial antigens that could elicit mucosal immune responses.

• Korean Journal of Veterinary Research
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• v.31 no.4
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• pp.501-507
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• 1991

Diagnosis of cryptosporidiosis is currently confirmed by the detection of the oocysts or endogenous stages in fecal or tissue samples. Various conventional staining methods and serodiagnostic techniques have been reported, but the latter has far been limited to a few laboratories. Cryptosporidium has recently been reported in mice and chiekens in Korea, but there has been no report on staining methods to the oocysts. The present study was performed by light and scanning electron microscopic observations, and discussed with staining properties of four conventional methods such as dichromate solution floatation method, Carbol fuchsin stain, Auramine-O stain and Giemsa stain method. Cryptosporidial oocysts were isolated from the laboratory mouse. In tissue sections of duodenum, jejunum, ileum, cecum and upper colon, numerous very small, basophilic bodies were observed on the border of mucosal epithelial cells. In scanning electron microscopic observations, a few of developmental stages of Cryptosporidium were seen. Two types of thick and thin-walled oocysts were recognized in the intestinal contents. Mean size of its were $5.19{\pm}0.23{\times}4.31{\pm}0.32{\mu}m$ and $5.14{\pm}0.25{\times}4.27{\pm}0.4{\mu}m$, respectively. Carbol fuchsin and Auramine-O stain methods are recommended as the satisfactory ones for the identification of Cryptosporidium oocysts. Giemsa stain was also recommended as available in the laboratory, because a few of developmental stage fo Cryptosporidium could be seen by it.

• Parasites, Hosts and Diseases
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• v.35 no.3
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• pp.181-188
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• 1997

In order to clarify the effect of cryptosporidiosis on immune response, histopathological changes associated with experimentally occurring bursal cryptosporidiosis in chickens were chronologically observed as the first step. A total of 150 2-day-old chickens was each inoculated orally with a single dose of 5 × 105 Cryptospori,mum bailevi oocysts. The chickens showed a normal profile of oocyst shedding in droppings. The bursa indices throughout the experimental period indicated negligible reactions. Numerous cryptosporidia occurred in the microvillous border of bursal epithelium between days 4 and 16 postinoculation (PI). Appearance of the most mast cells was followed by a dramatic loss of the protozoa in the bursa of Fabricius (BF). The distribution of the coccidium coincided with heterophil infiltration in the epithelium and adjacent lamina propria. The histopathological lesion was marked diffuse chronic superficial purulent bursitis with heterophil infiltration in the epithelium and adjacent lamina proprla and mucosal epithelial hyperplasia. These results suggest that the bursitis may induce immunosuppressive effect.

• Journal of Veterinary Science
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• v.22 no.3
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• pp.31.1-31.12
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• 2021

Background: Blackened intestines in slaughtered pigs have been commonly observed in China in recent years. However, no cause has been reported. Objectives: We attempted to determine whether the blackening of the pig intestine was related to an excess of copper (Cu) in their feed. Methods: In this study, we observed and collected porcine intestines in small- and large-scale pig slaughterhouses in Shandong province from May to October 2018. Twelve types of metal ions were detected in the black intestinal samples. Results: The Cu level in the intestine samples was mostly higher than the Chinese national limit for food. Further study showed that Cu supplementation in most commercial porcine feed also exceeded the national standard. An animal model (mouse) that could mimic the intestinal blackening in pigs was established. Compared to control mice, Cu accumulated in the liver and intestines of mice fed an excessive Cu level, confirming the excessive Cu in the feed may be considered the major cause of blackened porcine intestines. Microscopic examination revealed that black intestines had many particles containing Cu in the lamina propria of the intestinal mucosa, and the intestinal mucosal epithelial cells showed degeneration and necrosis. Conclusions: In conclusion, overuse of Cu in animal feed can lead to animal poisoning and Cu accumulation in animal products. Such overuse not only harms the health of livestock but can also affect public health.

• Journal of Life Science
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• v.17 no.12
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• pp.1669-1674
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• 2007

The conventional histochemical stains were used to study the properties of mucosubstances of the intestine in four teleostean species, i. e., Agramus agramus, Inimicus japonicus, Epinephelus chlorostigma, and Helicolenus dactylopterus, all belonging to the order Perciformes. The following methods were used; periodic acid Schiff (PAS), alcian blue (AB) pH at 2.5, AB pH at 1.0, AB pH at 2.5-PAS, and aldehyde fuchsin (AF) pH at 1.7-AB pH at 2.5 stain. The mucosal folds of intestines show differences in species and regions. Widely distributed in all portions studied, goblet cells situated between cylinderical epithelial cells are round or ovoid in shape. They were most densely distributed in distal intestine. In the middle and. distal intestine of Epinephelus chlorostigma and all regions of intestines of Agramus agramus, Inimicus japonicus, and Helicolenus dactylopterus, the presence of both acidic and neutral mucin was confirmed. The property of acidic mucosubstance was sialomucin. Neutral mucin was only encountered in the proximal intestine of Epinephelus chlorostigma. The amount and property of mucin showed differences in species and regions. In the distal intestine of Inimicus japonicus, the amount of acidic mucin is similar to that of neutral mucin. In all regions of intestine of Agramus agramus, proximal and middle intestine of lnimicus japonicus, middle and distal intestine of Epinephelus chlorostigma, and distal intestine of Helicolenus dactylopterus, acidic mucin occured more frequently than neutral mucin. The proximal and middle intestine of Helicolenus dactylopterus have more neutral mucin than acidic mucin.

• Parasites, Hosts and Diseases
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• v.28 no.1
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• pp.45-52
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• 1990

Intestinal histopathological changes due to infection with Echinostcma hortense (Trematoda) were studied in rats after experimental infection with the metacercariae. The metacercariae were obtained from the tadpoles of Rana nigrcmaculata, a second intermediate host infected in the laboratory. Total 18 albino rats(Sprague-Dawley) were given 200 matacercariae each and sacrificed on the day 1, 3, 7, 11, 22 or 44 post-infection(PI) Segments of- the small intestine at 1, 3, 5, 8 and 30 cm posterior to the pylorus(PTP) were rejected and studied histopathologically. 1. The flukes were seen to have intruded into the intervillous space in the upper small intestine at early stages(1∼3 days PI), however, they were located mainly in the intestinal lumen at later stages(7∼44 days PI) . The flukes were sucking and destroying the epithelial layers of villi with their oral and ventral suckers. 2. Histopathological changes of the intestine were recognizable in as early as 1∼3 days after infection, and the changes became severer as the infection progressed. 3. The intestinal mucosa was histopathologically characterized by villous atrophy and crypt hyperplasia throughout the infection period. Major villous changes were blunting, fusion, severe destruction and loss of epithelial layers of villi. Villous/crypt(V/C) height ratio was remarkably reduced from 3 : 1 in controls to 1 : 1 in severely infected animals. In the stroma of villi, inaamma- tory cell infiltrations, vascular congestion, edema, and/or fibrosis were recognized. The goblet cells were increased in number after 11 days PI. It was revealed in the present study that the pathological changes in the intestine of rats infected with E. hortense were chieay confined to the mucosal layer of the upper small intestine, however, the changes were very severe accompanying remarkable destruction of villi and loss of mucosal integrity, and persistent until 44 days PI.