Search PubMed⌕ Search

Biomedical subjects

M Kamiya

Publications and source records attributed to M Kamiya.

At least 127 records · Page 7Linked to original sources
PubMed1992

Natural Echinococcus multilocularis infection in a Norway rat, Rattus norvegicus, in southern Hokkaido, Japan.

Forty-two rats, Rattus norvegicus, captured at a garbage dump in southern Hokkaido, Japan, were examined, and one was found to be infected with Echinococcus multilocularis. The lesions were found in the liver, lung, mesenteric lymph nodes, greater omentum and also free in the abdominal cavity. No necrosis was observed in any of the lesions, and inflammatory reactions were mild. Protoscoleces were observed in the large liver cysts. A homogenate of these cysts, when transplanted into the abdominal cavity of three Mongolian gerbils and a rat, yielded numerous fully developed protoscoleces at 4-7 months post-inoculation. Judging from this, it is postulated that the rat could become a natural intermediate host for E. multilocularis in this area.

Animals↗
PubMed1992

Secondary Echinococcus multilocularis infection in severe combined immunodeficient (scid) mice: biphasic growth of the larval cyst mass.

E. multilocularis infection was suppressed in C.B-17 mice after intraperitoneal inoculation of protoscoleces, with larval cysts weighing no more than 1.0 g. In scid mice, which are genetically identical to C.B-17 except for a deficiency in functional lymphocytes, infection progressed and larval cysts reached a mass of 17.5 g at 15 weeks post-infection. The growth of the larval cyst mass in scid mice was similar to that in other susceptible mouse strains, with a biphasic pattern. Histological observations revealed giant cells and granulomatous inflammation in the C.B-17, but not in the scid mice. These results led to the conclusion that suppression of the growth of the larval cyst mass in the initial stage of infection in susceptible mice strains is caused by factors other than the host's lymphocytic immune response.

Animals↗
PubMed1992

A thymocytotoxic autoantibody reacts with the mouse brain cells in culture.

Autoimmune-prone New Zealand Black mice produce a large amount of autoantibodies cytotoxic for thymocytes (natural thymocytotoxic autoantibodies, NTA). A monoclonal NTA (NTA260) has been found to react with brain tissues as well as the cell surface of thymocytes. We investigated the expression of NTA 260 antigen in the primary culture of fetal brain cells. NTA260 labeled strongly the cytoplasm of nerve cells after fixation, but failed to stain the living cells. Western blot analysis revealed that NTA260 recognized predominantly a band at approximately 53 kDa in brain and thymic extracts. These findings indicate that neuronal NTA260 antigen, which has a molecular mass similar to that of thymocytes, is likely an intracellular component.

Animals↗
PubMed1992

Responses to larval Taenia taeniaeformis in mice with severe combined immunodeficiency (scid).

Responses to Taenia taeniaeformis infection were studied in mice with severe combined immunodeficiency (scid), which lack functional T and B lymphocytes. In the early phase of infection, accumulation of polymorphonuclear leucocytes (PML) occurred around the larvae in the liver of scid mice and their immunocompetent counterparts, C.B-17, (a BALB/c strain, genetically resistant to this parasite). PML accumulation continued until encapsulation of developing larvae by fibroblasts (14 days p.i.), and subsequent fibrosis resulted in granuloma formation. No infiltration of eosinophils or macrophages around larvae was observed in scid mice prior to granuloma formation, while in C.B-17 mice infiltration was observed as early as 5 days p.i., when specific antibodies could not be detected in the circulation. Most larvae were destroyed by 14 days p.i. in C.B-17 mice. In scid mice the larvae survived but the host capsules (cysts) were thin and most contained blood at 42 days p.i. In these cysts, inflammatory cells were observed on the larval surface and in invaded parasite tissue. Hepatocyte coagulation necrosis adjacent to larvae was commonly found in C.B-17 mice by 5 days p.i., while it did not occur in scid mice throughout these experiments. These results suggest that in host responses to larval T. taeniaeformis, PML accumulation and encapsulation by fibrosis are T and B cell independent, while eosinophil and macrophage infiltration, as well as resistance to infection, are T and/or B cell dependent. Additionally, there may be an association between host cell necrosis around larvae and T and/or B cell responses.

Animals↗
PubMed1992

Development of a 2,048 x 2,048-pixel image intensifier-TV digital radiography system. Basic imaging properties and clinical application.

RATIONALE AND OBJECTIVES: A 2,048 x 2,048-pixel matrix image intensifier (II)-TV digital radiography system has been developed. Potential clinical applications of this new II-TV system were investigated. METHODS: Basic imaging properties were assessed with clinical applications to gastrointestinal (GI) tract and chest examinations. RESULTS: Basic imaging properties showed improvement of modulation transfer functions (MTFs) from the 1,024 x 1,024- to the 2,048 x 2,048-pixel matrix and approximated the screen-film system at low spatial frequencies. Receiver operating characteristic (ROC) curves of simulated linear shadows improved similarly. Clinical applications showed that the image quality of the 2,048 x 2,048-pixel matrix was comparable with that of the screen-film system for upper GI and chest radiography, but the image quality of the screen-film system was better for the lower GI tract. CONCLUSIONS: The authors' II-TV digital radiography system is clinically applicable to gastrointestinal and chest examinations.

Digestive System↗
PubMed1992

Gastrointestinal examinations with digital radiography.

Basic imaging properties and clinical usefulness of an upgraded digital radiography system were evaluated. The system, which has 1,024 x 1,024 and 2,048 x 2,048 matrices, was upgraded with smaller focal spots (0.3 and 0.8 mm) and reduced thickness of the photoconductive layer of the video camera. Screen-film and digital images (with and without postprocessing) of the upper and lower gastrointestinal (GI) tract were used in the clinical evaluation. Overall modulation transfer functions of the upgraded digital system were comparable to those of the screen-film system, especially at the lower spatial frequency. Threshold contrasts of the two systems were similar despite a 50% reduction in incident exposure for the digital system. For the upper GI tract, digital images processed with unsharp masking techniques were comparable in quality to screen-film images before and after upgrade of the system. For the lower GI tract, screen-film images were better than digital images, except for those produced with a 2,048 x 2,048 matrix with unsharp masking. Further evaluation of the system for examination of other parts of the body seems warranted.

Digestive System↗
PubMed1992

[Laboratory breeding of the red-backed vole (Clethrionomys rufocanus bedfordiae)].

Laboratory matings were attempted to establish breeding colonies of red-backed voles (Clethrionomys rufocanus bedformidae) as experimental animals. For these mating, 10 pairs of red-backed voles which were captured in the Tohbetsu region of Hokkaido, Japan and their litters were used. In the results for two years, 1987 to 1988, the rates of pregnancy, birth and weaning were 35.4%, 94.5% and 79.5%, respectively. The mean litter size was 5:1 +/- 1.6 with a range of 1 to 9. The mean gestation period was 20.0 +/- 0.7 days with a range of 18 to 22. These results suggest that planned production of red-backed voles in the laboratory is possible. To determine intraregional variations of red-backed voles with a view to the establishment of a strain by inbreeding, restriction patterns of mitochondrial DNAs using seven restriction endonucleases were compared. Four different patterns were obtained from wild red-backed voles used in the present study.

Animals↗
PubMed1992

Occurrence of a Syngamus sp. in tundra voles (Microtus oeconomus) collected on St. Lawrence Island, Bering Sea.

A species of syngamid nematode belonging to the genus Syngamus was found in the respiratory tract (terminal trachea to bronchi) of tundra voles (Microtus oeconomus) collected on St. Lawrence Island, Alaska (USA). Its prevalence in June 1989 was greater than 29% (12 of 41 male voles and seven of 24 females) in the village of Savoonga, while no nematodes were found from 41 voles collected in the village of Gambell. Lesions included dilatation of parasitized respiratory ducts and peribronchial and perivascular cuffing by lymphoid cells, mainly plasma cells, in parasitized lobes. Morphologically, this syngamid species differed from S. microtinae reported previously from the same host species as well as from other syngamids known from avian hosts.

Alaska↗
PubMed1992

Experimental evaluation of mink and Apodemus speciosus in the Echinococcus multilocularis life-cycle in Hokkaido, Japan.

The epizootiological status of mink (Mustela vison) as definitive hosts and Apodemus speciosus as intermediate hosts in the transmission of Echinococcus multilocularis in Hokkaido, Japan, were evaluated by orally inoculating mink with protoscoleces, and A. speciosus with eggs of the cestode, respectively. No tapeworms were recovered from the alimentary tract of the mink, and no hydatid cysts were recovered from the viscera of the egg-inoculated A. speciosus. We conclude that mink and A. speciosus cannot serve as definitive hosts and intermediate hosts of E. multilocularis, respectively, in Hokkaido.

Animals↗
PubMed1992

Immune response to Echinococcus multilocularis infection in the mouse model: a review.

Echinococcus multilocularis is a cestode helminth which, along with E. granulosus, E. oligarthus and E. vogeli is a causative agent of hydatid disease in man. In the intermediate host (including man), cysts formed by the metacestode (larval stage) develop in the internal organs, causing functional impairment which often leads to the death of the host. In this review larval E. multilocularis infection in mice, the most popular experimental intermediate host, is examined, and the immune response to the organism is described in detail. Evidence is presented which suggests that cell-mediated immunity (CMI) plays a large role in suppression of larval growth. Congenitally athymic nude mice, and mice treated to remove thymocytes had high susceptibility to infection, while mice strains assessed as having high helper T lymphocyte function showed resistance to infection. The degree of antibody response shown by the host does not correlate with the susceptibility to E. multilocularis. Infection with E. multilocularis is accompanied by immunosuppression, manifested by inhibition of effector cell chemotaxis and receptor expression, suppressor macrophage and lymphocyte activity, decline in helper T-lymphocyte activity and immune-complex deposition.

Animals↗
PubMed1991

Lice and easy.

Explore the source record for details and available documents.

Animals↗
PubMed1991

Congenital angiotropic lymphoma (intravascular lymphomatosis) of the T-cell type.

The autopsy of a stillborn infant showed an extensive intravascular proliferation of atypical cells throughout the body. There was no infiltration by these cells of the parenchyma of the bone marrow, lymph nodes, or thymus. By histochemistry, these cells were negative for naphthol-ASD-chloroacetate esterase, a marker of granulocytes. By immunohistochemistry, they were reactive with MT-1 and anti-Leu-22, but unreactive with MB-1, L26, anti-Leu-M1, Tü-9, and antihemoglobin antibodies. A few cells reacted with antileukocyte common antigen and UCHL-1. Based on these findings, the lesion was diagnosed as angiotropic lymphoma (intravascular lymphomatosis) of the T-cell type, which occurred congenitally. Most angiotropic lymphomas in the literature are of the B-cell type, and no leukemia virus type I antibody was negative in the mother.

Female↗
PubMed1991

Vaccination against Taenia taeniaeformis infection in rats using a recombinant protein and preliminary analysis of the induced antibody response.

Primary screening of a cDNA expression library of Taenia taeniaeformis oncospheres in lambda gt11 bacteriophage was carried out using rabbit anti-T, taeniaeformis oncosphere serum affinity-purified from oncosphere pellets. From approximately 1.6 x 10(5) plaques, 21 single clones that were positive with the affinity-purified antibodies were isolated. Sibling analysis revealed that 17 clones out of the 21 could be assigned to five different antigen families. Only family 1 was strongly recognized by a serum prepared in a rabbit against a partially purified host-protective oncosphere antigen fraction. The fragments of lambda DNA were inserted into a pGEX plasmid vector that encodes glutathione S-transferase (GST) of Schistosoma japonicum. Clones designated TtO-18, -49.53 (family 1), 46 (family 2), 15 (family 3), 40 (family 4) and 66 (family 5) were established as subclones in pGEX-1 plasmid vectors which produced GST fusion proteins. All GST fusion proteins were soluble and recognized by anti-GST and anti-TtO sera. Three vaccination experiments with these fusion proteins using specific-pathogen-free Wistar rats revealed that all three fusion proteins of family 1 were exclusively effective against T. taeniaeformis oncosphere challenge with approximately 95% and 91% reductions in cystic metacestode and total metacestode recoveries, respectively. Rats vaccinated with fusion proteins of family 1 produced antibodies which reacted with a 21-kDa oncosphere antigen component which appeared to be a major oncosphere stage-specific antigen.

Animals↗
PubMed1991

Phenotypic changes in hepatic mast cells accumulating around the metacestodes of Taenia taeniaeformis in rats.

Staining properties, kinetics and degranulation of the hepatic mast cells (HMC) accumulating around the metacestodes of Taenia taeniaeformis in the liver of rats were studied. Two different types of HMC, designated as Type I and Type II, could be classified according to histochemical properties and response to compound 48/80. Type I cells resembled mucosal mast cells (MMC), whereas Type II did not. HMC, mostly Type I, were observed from day 14 postinfection (PI), while Type II were seen only from day 28 PI. On day 28 PI, Type II represented a transitional staining pattern between MMC and connective tissue mast cells (CTMC). The ratio of Type II to Type I increased gradually with the course of infection and was about 1 to 1 on day 70 PI. At this time, most of the HMC that constituted Type II as well as CTMC could be stained with berberine sulfate. While the phenotypic change of HMC to CTMC was found in the middle and inner capsular layers, most of the HMC in the outer capsular layer maintained the phenotype of MMC. The present results suggest that hepatic mast cells increased as the MMC phenotype, then showed the heterogeneity in which the transitional form of mast cells emerged followed by the appearance of the CTMC type.

Animals↗
PubMed1991

Laboratory rodent models for the tapeworm-stage of Taenia saginata and other related taeniid species.

Attempts were carried out to establish alternative definitive host systems for Taenia saginata, T. crassiceps, T. hydatigena, Echinococcus multilocularis and E. granulosus, in rodents. Following oral inoculation of cysticerci or protoscoleces, the tapeworm-stage development and sexual maturation of the 5 taeniid species in the intestine of a golden hamster (GH) and Mongolian gerbil (MG), both treated with prednisolone, were examined. Sexually mature T. saginata tapeworms were recovered from MG pretreated with prednisolone. The life cycles of E. multilocularis can be completed in MG and T. crassiceps in both MG and GH. T. hydatigena and E. granulosus developed to a certain extent at the tapeworm stage in MG pretreated with prednisolone. Potential use of rodents as an alternative definitive host for taeniid species is discussed.

Animals↗
PubMed1991

Current status of food-borne parasitic zoonoses in Japan.

Progress in public sanitation over the past four decades has greatly decreased the prevalence of soil-transmitted gastrointestinal parasites in Japan. Although food-borne zoonotic parasites also show a similar trend, there continues to be a steady flow of patients infected with the latter parasites. This stems from the traditional popularity among the Japanese of eating raw food, coupled with an increasing fondness for rare delicacies, overseas travel, and consumption of exotic food. These factors have given rise to many reports of anisakiasis, angiostrongyliasis, trichinellosis, capillariasis, gnathostomiasis, paragonimiasis, sparganosis, etc. Food-borne parasitic zoonoses in Japan can be roughly divided into three categories according to the type of food consumed, namely, livestock meat, wild game meat, and aquatic food. The current status of these diseases, including a discussion of the retro- and prospective trends are presented.

Animals↗
PubMed1990

Growth of a Japanese isolate of Taenia crassiceps in intermediate and definitive hosts.

Higher infection rates were observed in gerbils and voles than in ICR mice after oral inoculation with eggs of a Japanese isolate of Taenia crassiceps. Asexual reproduction of T. crassiceps cysticerci was observed in all gerbils and voles infected i.p. with the cysticerci. However, ICR mice and Wistar rats were not suitable for the asexual proliferation of T. crassiceps. The hooks of cysticerci from mice were smaller than those from gerbils. In experimentally infected puppies, parasite development was noted as follows: strobilation and initial differentiation of the genital primordia on day 7 postinoculation (p.i.), appearance of the testes on day 9, observation of the ovaries on day 10, and development of the lateral branches of the uterus on day 15. The prepatent period was 27-31 days. After day 15 p.i., most of the worms were recovered from the middle third of the small intestine. The number of proglottids shed per day by each strobila was about 1. The number of eggs contained in a gravid segment was about 13,000.

Animals↗