The present experimental study was undertaken to observe the chronological change of the worm structure of Clonorchis sinensis and the pathological findings of the liver when this fluke was inoculated to the mouse intraperitoneally. The recovery rate, survival rate, location and size of the inoculated worms as well as the pathological changes of the liver were investigated for the comparison among the groups of mice, classified by number of worms and the duration of experiment. The results obtained were summarized as follows: The recovery and survival rates of the worms decreased especially 28 days after the inoculation. Most of worms (90.l percent) were collected from the peritoneal cavity and some of worms were found tightly adherent to the capsules of the liver, spleen, stomach, intestine and diaphragm. There were no worms recovered penetrated in the parenchymes of these organs. The mean worm size after inoculation was smaller than that before inoculation. At the 10th day after the inoculation, the shrinkage of posterior portion of the worm body was observed. Remarkable atrophy in the reproductive organs of the worm, such as spermatheca, testes, vitelline glands and ovary was frequently observed at the 10th day of inoculation. Histopathologically the liver failed to show any parasitic worm inside the intrahepatic biliary system. However, multiple well formed egg-containing granulomas were present along the liver capsule. These necrotic granulomas were occasionally found under the fibrotic liver capsule. Focal necrosis and focal phlebitis together with vascular dilatation were prominent features seen in the liver. The bile duct in the liver showed mild dilation of the lumen, flattening of epithelial cells and periductal small round cell infiltration. Neither adenomatous hyperplasia nor portal fibrosis was seen in the whole experimental groups. Foci of intralobular micro-granulomas were found in some experimental animals. The worms recovered in the capsule of the liver were degenerated and necrotized. Usually, there were remarkable capsulitis and granuloma formation around the eggs.
parasitology-helminth-trematoda ; Clonorchis sinensis ; pathology ; liver ; spleen ; stomach ; intestine ; diaphragm ; granuoma ; peritoneal cavity

Leishmania (L.) tropica is a causative agent of cutaneous leishmaniasis, and occasionally of visceral or viscerotropic leishmaniasis in humans. Murine models of Leishmania infection have been proven to be useful for elucidation of mechanisms for pathogenesis and immunity in leishmaniasis. The aim of this study was to establish a murine model for human viscerotropic leishmaniasis, and the growth pattern of L. tropica was studied in different tissues of BALB/c mice in order to find out whether the parasite visceralizes in this murine model. L. major was used as a control as this species is known to cause a progressive infection in BALB/c mice. L. tropica or L. major was injected into the footpad of mice, and thickness of footpad, parasite loads in different tissues, and the weight of the spleen and lymph node were determined at different intervals. Results showed that L. tropica visceralizes to the spleen and grows there while its growth is controlled in footpad tissues. Dissemination of L. tropica to visceral organs in BALB/c mice was similar to the growth patterns of this parasite in human viscerotropic leishmaniasis. The BALB/c model of L. tropica infection may be considered as a good experimental model for human diseases.
Animals ; *Disease Models, Animal ; Female ; Foot/parasitology ; Humans ; Leishmania major/growth & development ; Leishmania tropica/*growth & development ; Leishmaniasis/*parasitology ; Lymph Nodes/parasitology/pathology ; Mice ; Mice, Inbred BALB C ; Organ Size ; Spleen/parasitology/pathology

To determine alteration of immune responses during visceral larva migrans (VLM) caused by Toxascaris leonina at several time points, we experimentally infected mice with embryonated eggs of T. leonina and measured T-helper (Th) cell-related serial cytokine production after infection. At day 5 post infection (PI), most larvae were detected from the lungs, spleen, intestine, and muscle. Expression of thymic stromal lymphopoietin (TSLP) and CCL11 (eotaxin) showed a significant increase in most infected organs, except the intestine. However, expression of the CXCL1 (Gro-alpha) gene was most highly enhanced in the intestine at day 14 PI. Th1-related cytokine secretion of splenocytes showed increases at day 28 PI, and the level showed a decrease at day 42 PI. Th2-related cytokine secretion of splenocytes also showed an increase after infection; in particular, IL-5 level showed a significant increase at day 14 PI, and the level showed a decrease at day 28 PI. However, levels of Th17-related cytokines, IL-6 and IL-17A, showed gradual increases until day 42 PI. In conclusion, Th1, Th2, and Th17-related cytokine production might be important in immune responses against T. leonina VLM in experimental mice.
Animals ; Brain/parasitology ; Cytokines/*metabolism ; Female ; Gene Expression Regulation ; Heart/parasitology ; Interleukins/*metabolism ; Intestines/parasitology ; Larva Migrans, Visceral/*immunology/parasitology ; Liver/parasitology ; Lung/parasitology/pathology ; Mice ; Mice, Inbred C57BL ; Muscles/parasitology ; Spleen/parasitology ; Th1 Cells/immunology ; Th17 Cells/immunology ; Th2 Cells/immunology ; Toxascaris/*immunology

In order to understand the tissue responses of albino rat host against Paragonimus iloktsuenensis infection, the histopathological changes of the spleen and the lungs in 6 experimental groups of rats were observed in relation with the growth, maturation and migration of this lung fluke. Rats of the experimental groups, each group consisted of 5 rats, were infected with the metacercariae of P. iloktsuenensis which were isolated from brackish water crab, Sesarma dehaani, and were kept for 3 days, 3 weeks, 4 weeks, 7 weeks, 10 weeks and 14 weeks of infection period. Peripheral blood smear slides for the differential leukocyte count were prepared and also worm collection was completed immediately after the infection period. Paraffin sections of the spleen and the lung tissue were stained with hematoxylin-eosin and methyl-green-pyronin (MGP) stain. Those materials from the experimental groups were examined in comparison with the materials obtained from control group, with special reference to immunologic aspects of host response. The results obtained were as follows: The counts of large pyroninophilic cell (LPC) in the periarterial sheath of spleen were rapidly increased in earlier period of infection, and those of peribronchial lymphatic tissue started to increase after the penetration of lungfluke into the lungs. The LPC counts of both the spleen and the lungs were on the decrease in conjunction with the necrosis of the lung fluke in 14th week of infection. On observing differential leukocyte count of peripheral blood smear, the fluctuation of lymphocyte count was proportional to that of LPC count, and the lymphocyte count was consistently higher than that of normal rats. On the other hand, neutrophil count of experimental group showed reciprocal relation to the LPC counts. The nature and characteristics of pulmonary lesion produced by the P. iloktsuenensis were just the same as those produced by P. westermani. The lesions were represented by thick and fibrosclerotic cavern, granuloma due to eggs, pneumonic process and cellular infiltrations.
parasitology-helminth-trematoda ; paragonimiasis ; Paragonimus iloktsuenensis ; histology ; pathology ; lung ; spleen ; granuloma ; pneumonia ; hematoxylin-eosin ; methyl-green-pyronin

Hydatid disease (HD) is an endemic illness in many countries, and it poses an important public health problem that's influenced by peoples' socioeconomic status and migration that spreads this disease. Although rare, it may occur in any organ or tissue. The most common site is the liver (59-75%), followed in frequency by lung (27%), kidney (3%), bone (1-4%) and brain (1-2%). Other sites such as the heart, spleen, pancreas and muscles are very rarely affected. Unusual sites for this disease can cause diagnostic problems. This pictorial essay illustrates various radiological findings of HD in the liver, spleen, kidney, pancreas, peritoneal cavity, omentum, adrenal, ovary, lung, mediastinum and retroperitoneum. Familiarity with the imaging findings of HD may be helpful in making an accurate diagnosis and preventing potential complications.
Abdominal Cavity/parasitology/radiography ; Adolescent ; Adult ; Child ; Child, Preschool ; Contrast Media/administration & dosage ; Digestive System/pathology/radiography/ultrasonography ; Digestive System Diseases/diagnosis/parasitology ; Echinococcosis/*diagnosis/parasitology/*radiography ; Endocrine Glands/parasitology/radiography ; Female ; Humans ; Kidney/parasitology/pathology ; Liver/parasitology/radiography ; Lung/parasitology/radiography ; Magnetic Resonance Imaging/methods ; Male ; Mediastinum/parasitology/radiography ; Middle Aged ; Pancreas/parasitology/radiography ; Radiographic Image Enhancement/methods ; Spleen/parasitology/radiography ; Tomography, X-Ray Computed/methods

In intestinal helminth infections, Th2 immune respones are generally associated with mucin secretion for worm expulsion from the host intestine. In particular, IL-4 and IL-13 are the important cytokines related with intestinal mucus production via STAT6 signalling in nematode infections. However, this perspective has never been studied in Gymnophalloides seoi infection. The present study aimed to observe the STAT6 signalling and cytokine responses in C57BL/6 mice, a mouse strain resistant to infection with this trematode. The results showed that worm expulsion occurred actively during days 1-2 post-infection (PI), when goblet cells began to proliferate in the small intestine. The STAT6 gene expression in the mouse spleen became remarkable from day 2 PI. Moreover, G. seoi infection induced a significant increase of IL-13 from day 4 PI in the spleen of infected mice. Our results suggested that goblet cell hyperplasia and worm expulsion in G. seoi-infected mice should be induced by STAT6 signalling, in which IL-13 may be involved as a dominant triggering cytokine.
Animals ; Crassostrea ; Female ; Goblet Cells/*pathology ; Hyperplasia/pathology ; Interleukin-13/*metabolism ; Interleukin-4/*metabolism ; Intestine, Small/immunology ; Metacercariae ; Mice ; Mice, Inbred C57BL ; STAT6 Transcription Factor/*metabolism ; Signal Transduction ; Specific Pathogen-Free Organisms ; Spleen/immunology ; Trematoda/*immunology ; Trichinellosis/*immunology/parasitology

In order to know the effect of pre-existing Trichinella spiralis infection on experimentally induced intestinal inflammation and immune responses, we induced colitis in T. spiralis-infected mice and observed the severity of colitis and the levels of Th1, Th2, and regulatory cytokines and recruitment of CD4+CD25+Foxp3+ T (regulatory T; Treg) cells. Female C57BL/6 mice were infected with 250 muscle larvae; after 4 weeks, induction of experimental colitis was performed using 3% dextran sulfate sodium (DSS). During the induction period, we observed severity of colitis, including weight loss and status of stool, and evaluated the disease activity index (DAI). A significantly low DAI and degree of weight loss were observed in infected mice, compared with uninfected mice. In addition, colon length in infected mice was not contracted, compared with uninfected mice. We also observed a significant increase in production of pro-inflammatory cytokines, IL-6 and IFN-gamma, in spleen lymphocytes treated with DSS; however, such an increase was not observed in infected mice treated with DSS. Of particular interest, production of regulatory cytokines, IL-10 and transforming growth factor (TGF)-beta, in spleen lymphocytes showed a significant increase in mice infected with T. spiralis. A similar result was observed in mesenteric lymph nodes (MLN). Subsets of the population of Treg cells in MLN and spleen showed significant increases in mice infected with T. spiralis. In conclusion, T. spiralis infection can inhibit the DSS-induced colitis in mice by enhancing the regulatory cytokine and Treg cells recruitment.
Animals ; Colitis/chemically induced/*immunology/pathology ; Cytokines/genetics/*immunology/metabolism ; Dextran Sulfate/adverse effects ; Disease Models, Animal ; Female ; Forkhead Transcription Factors/immunology/metabolism ; *Gene Expression Regulation ; Larva ; Mice ; Mice, Inbred C57BL ; Spleen/immunology ; T-Lymphocytes, Regulatory/*immunology ; Trichinella spiralis/*immunology ; Trichinellosis/*immunology/parasitology