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Biomedical subjects

M Kamiya

Publications and source records attributed to M Kamiya.

At least 19 recordsLinked to original sources
PubMed2006

14-3-3- and II/3-10-gene expression as molecular markers to address viability and growth activity of Echinococcus multilocularis metacestodes.

The present study aimed to search for and characterize parasite molecules, whose expression levels correlate with the viability and growth activity of Echinococcus multilocularis metacestodes. We focused on the expression profiles of 2 parasite-derived genes, 14-3-3 and II/3-10, as putative molecular markers for viability and growth activity of the larval parasite. In experiments in vivo, gene expression levels of 14-3-3 and II/3-10 were relatively quantified by real-time reverse transcription-PCR using a housekeeping gene, beta-actin, as a reference reaction. All three reactions were compared with growth activity of the parasite developing in permissive nu/nu and in non-permissive wild type BALB/c mice. At 2 months p.i., the transcription level of 14-3-3 was significantly higher in parasites actively proliferating in nu/nu mice compared to parasites moderately growing in wild type mice. Immunoblotting experiments confirmed at the protein level that 14-3-3 was over-expressed in parasites derived from nu/nu mice at 2 months p.i. In vitro treatment of E. multilocularis with an anti-echinococcal drug nitazoxanide resulted in a significant decrease of both 14-3-3 and II/3-10 transcription levels found after 8 days of treatment, which correlated with the kinetics of a housekeeping gene, beta-actin. The conclusion is that 14-3-3, combined with II/3-10, exhibits good potential as a molecular marker to assess viability and growth activity of the parasite.

14-3-3 Proteins↗
PubMed2006

Development of Taenia asiatica cysticerci to infective stage and adult stage in Mongolian gerbils.

The development of metacestodes and adult worms of Taenia asiatica in Mongolian gerbils (Meriones unguiculatus) were observed. Cysticerci were recovered from gerbils subcutaneously injected with hatched oncospheres. The recovery rate ranged from 0.1 to 3.2%. No cysticerci were recovered from the orally inoculated gerbils. The infectivity of the cysticerci recovered at 48 weeks post-infection was evaluated. Tapeworms were recovered on day 14 post-infection from the small intestine of 5 of 11 gerbils, with a recovery rate of 27% (6 worms recovered/22 worms inoculated). Three and four adult worms were recovered from two human volunteers who ingested five cysticerci after 4 months post-infection. In worms recovered from gerbils, segmentation and genital primordia in the posterior proglottids and hooklets in the residual rostellum were observed. The results indicate that gerbils can serve as an alternative intermediate host and that partial development of the adult worm stage occurs in gerbils.

Adult↗
PubMed2005

Development of Taenia saginata asiatica metacestodes in SCID mice and its infectivity in human and alternative definitive hosts.

Development of Taenia saginata asiatica metacestodes in SCID mice, and its infectivity in humans, golden hamsters, and Mongolian gerbils as alternative definitive hosts, were investigated. Cysticerci were recovered from SCID mice that were subcutaneously injected with hatched oncospheres of T. s. asiatica. The morphological changes of metacestodes were observed. The recovered cysticerci were fed to gerbils, hamsters and humans, to check for their infectivity. Tapeworms were recovered from gerbils and hamsters fed with 20 to 45 week-old cysticerci, and proglottids excretions were observed in human volunteers fed with 45 week-old cysticerci. However, no tapeworms were recovered from gerbils fed with 10 week-old cysticerci. Our results suggest that T. s. asiatica oncospheres needed more than 20 weeks to develop to maturity in SCID mice to be infective to both their natural and alternative definitive hosts.

Animals↗
PubMed2005

Structural analysis of leucine-rich-repeat variants in proteins associated with human diseases.

A number of human diseases have been shown to be associated with mutation in the genes encoding leucine-rich-repeat (LRR)-containing proteins. They include 16 different LRR proteins. Mutations of these proteins are associated with 19 human diseases. The mutations occur frequently within the LRR domains as well as their neighboring domains, including cysteine clusters. Here, based on the sequence analysis of the LRR domains and the known structure of LRR proteins, we describe some features of different sequence variants and discuss their adverse effects. The mutations in the cysteine clusters, which preclude the formation of sulfide bridges or lead to a wrong paring of cysteines in extracellular proteins or extracellular domains, occur with high frequency. In contrast, missense mutations at some specific positions in LRRs are very rare or are not observed at all.

Genetic Diseases, Inborn↗
PubMed2003

A case of germinoma in the septum pellucidum manifesting as amnesia and hemiparesis.

BACKGROUND: We report a rare case of germinoma mainly located in the septum pellucidum. CASE DESCRIPTION: A 19-year-old man presented with germinoma located in the septum pellucidum manifesting as amnesia and right hemiparesis. Magnetic resonance imaging demonstrated a heterogeneously enhanced mass in the septum pellucidum and abnormal T2-weighted signals in the left basal ganglia. An anterior transcallosal approach was performed to remove the mass in the septum pellucidum. The histological diagnosis was germinoma. Radiotherapy and chemotherapy were given. He was discharged with slight amnesia and right hemipareis. INTERPRETATION: Intracranial germinoma can arise from the septum pellucidum.

Adult↗
PubMed2003

Detection of nonmelanoma skin cancer micrometastases in lymph nodes by using reverse transcriptase-polymerase chain reaction for keratin 19 mRNA.

BACKGROUND: A new sensitive method for the detection of skin cancer micrometastases in lymph nodes is based on amplification of keratin 19 (K19) mRNA by reverse transcriptase-polymerase chain reaction (RT-PCR). OBJECTIVES: To compare results of RT-PCR with those of histological examination in terms of the detection rate of skin cancer micrometastases. METHODS: Twenty-six lymph nodes obtained from 13 patients with squamous cell carcinoma (SCC), eccrine porocarcinoma and Paget's disease were investigated by histological examination (haematoxylin and eosin sections) and RT-PCR. RT-PCR was performed on extracted RNA by using K19 primer pairs. RT-PCR products were visualized by ethidium bromide staining and confirmed by non-radioactive hybridization with K19-specific probes. RESULTS: All of 10 histologically positive lymph nodes yielded the expected 460-bp band. Of the 16 histologically negative lymph nodes, one (6%) was found by RT-PCR to express K19 mRNA, indicating the presence of micrometastases which could not be detected by histological examination. A serial dilution study using RNA extracted from SCC cells mixed with RNA extracted from normal lymph node cells showed a detection sensitivity of K19 RT-PCR of 10-5 micro g cancer cell RNA in 1 micro g lymph node RNA. Nested RT-PCR showed a detection sensitivity of one tumour cell in 106 lymphocytes. CONCLUSIONS: These results demonstrate the usefulness of K19 RT-PCR for the detection of skin cancer micrometastases in lymph nodes.

Biomarkers, Tumor↗
PubMed2002

Retarded gastric acid secretion in rats infected with larval Taenia taeniaeformis.

The influence of hepatic larval Taenia taeniaeformis infection on gastric acid secretory activity and gastric mucosal integrity was investigated. After 12 weeks of infection with 2,000 T. taeniaeformis eggs, the gastric pH values of control and infected rats were 4.1+/-0.6 (mean +/- SD) and 8.4+/-0.2, respectively. There was no difference in the basal acid secretion between control (1.7+/-0.7 micro Eq.H(+)/15 min) and infected (1.9+/-0.3) rats. However, infected rats failed to respond to histamine stimulation, the maximum acid output level being 2.8+/-0.4 in the infected rats, compared to 12.9+/-3.3 in control rats. Larval T. taeniaeformis infection resulted in the suppression of gastric acid secretion leading to hypergastrinemia.

Animals↗
PubMed2002

Potential remedy against Echinococcus multilocularis in wild red foxes using baits with anthelmintic distributed around fox breeding dens in Hokkaido, Japan.

The effect of bait-delivered anthelmintic to reduce the prevalence of Echinococcus multilocularis in wild red foxes was evaluated in Koshimizu, in the eastern part of Hokkaido, Japan. The study area (200 km2) was divided into baited and non-baited sections. The anthelmintic baits were distributed around fox den sites in the baited section every month for 13 months. After 1 year of the anthelmintic bait distribution, the prevalence of E. multilocularis in foxes, evaluated either by the parasite egg examination (from 27.1 to 5.6%) or coproantigen ELISA (from 59.6 to 29.7%), decreased in the baited section contrasting to that in the non-baited section (parasite egg: from 18.8 to 24.2%; ELISA: from 41.9 to 45.8%). The prevalence of E. multilocularis in grey red-backed vole Clethrionomys rufocanus, caught around fox dens, born after bait distribution also decreased and was significantly lower than that in non-baited section. However, within the study periods, the coproantigen-positive rate in fox faeces sporadically increased, while egg-positive rate constantly decreased. Since coproantigen ELISA can detect pre-patent infection, this observation indicates that reinfection pressure in the baited section was still high even after the 13 months of anthelmintic bait distribution. Therefore, the bait distribution longer than our study period is required for the efficient control of E. multilocularis in wild red fox population.

Animals↗
PubMed2001

Association between a polymorphism of the transforming growth factor-beta1 gene and genetic susceptibility to ossification of the posterior longitudinal ligament in Japanese patients.

STUDY DESIGN: A study was conducted to determine the association between polymorphism of the transforming growth factor-beta1 (TGF-beta1) gene and ossification of the posterior longitudinal ligament (OPLL) prevalence. OBJECTIVE: To examine whether the T869-->C polymorphism of the TGF-beta1 gene is associated with genetic susceptibility to OPLL in Japanese subjects. SUMMARY OF BACKGROUND DATA: In the posterior longitudinal ligament, OPLL is associated with abnormal calcium metabolism. Several candidate genes are associated with the prevalence of OPLL. In the ossified matrix and chondrocytes of adjacent cartilaginous areas of OPLL, TGF-beta1 is overexpressed. METHODS: The TGF-beta1 genotype was identified with an allele-specific polymerase chain reaction method in 319 Japanese subjects (46 subjects with OPLL and 273 control subjects). RESULTS: There was a significant association between the T869-->C genotype and the prevalence of OPLL in the cervical spine. Multivariable logistic regression analysis, adjusted for gender, age, height, and body weight, showed that the frequency of the C allele was significantly higher in subjects with OPLL than in control subjects. CONCLUSIONS: The T869-->C polymorphism of the TGF-beta1 gene is a genetic determinant of a predisposition to OPLL, with the C allele representing a risk factor for genetic susceptibility to OPLL in Japanese subjects. Therefore, TGF-beta1 genotyping may be useful in the prevention of OPLL.

Aged↗
PubMed2001

Functional annotation of a full-length mouse cDNA collection.

The RIKEN Mouse Gene Encyclopaedia Project, a systematic approach to determining the full coding potential of the mouse genome, involves collection and sequencing of full-length complementary DNAs and physical mapping of the corresponding genes to the mouse genome. We organized an international functional annotation meeting (FANTOM) to annotate the first 21,076 cDNAs to be analysed in this project. Here we describe the first RIKEN clone collection, which is one of the largest described for any organism. Analysis of these cDNAs extends known gene families and identifies new ones.

Animals↗
PubMed2001

Inhibitory effect of different UV lamps on the infectivity of taeniid eggs.

The expanding distribution of alveolar echinococcosis in Hokkaido, Japan necessitates a search for control measures, particularly for killing Echinococcus eggs; and UV radiation is a potential tool. To determine the effective UV lamp and its optimum duration of exposure to inhibit the infectivity of taeniid eggs, three UV lamps (UVA, UVB and UVC) with peak emissions at different wavelengths were used to irradiate eggs of Taenia taeniaeformis. Irradiation was done in durations of 30, 90, 270, 810, 2,430 and 7,290 s. Infectivity of the irradiated eggs was tested by oral inoculation into rats. The inhibitory effect of the UV lamps at different exposure durations was determined by the reduction in the larval cyst establishment and by the delay of larval development. The UVC lamp (narrow peak at 254 nm) was found to be the most effective lamp at an exposure duration of more than 2,430 s (2,430 mJ/cm2), attaining 100% reduction. Also, shorter exposure durations produced a significant effect on the development of irradiated eggs in a greater percentage of small cysts (> 1 mm) among the metacestodes. Irradiation delayed the development of some cysts, as observed in histopathological sections. UVA and UVB lamps were not able to attain 100% reduction. It is concluded that the UVC lamp can be used as a tool in sterilizing taeniid eggs and is thus a promising method to control echinococcosis, although it may require a higher intensity of exposure.

Animals↗
PubMed2001

Effects of cyclodextrins on photodegradation of organophosphorus pesticides in humic water.

Cyclodextrin (CyD) effects on photodegradations of organophosphorus pesticides in humic water were monitored on the basis of the increase percentage of the photodegradation rate constant for CyD-containing humic water. Remarkable promotion effects of CyDs were observed in humic water for photo-induced radical generation. The promotion effects could be mainly assigned to the inclusion effects of CyDs to catalyze interactions of pesticides with reactive radicals generated by the humin photosensitizer and inclusion-trapped in CyDs.

Cyclodextrins↗
PubMed2001

Effects of selected metal ions on photodegradation of organophosphorus pesticides sensitized by humic acids.

Selected metal ions having paramagnetic property were found to exert inhibition effects on aquatic photodegradation of organophosphorus pesticides sensitized by humic acids, according to the increasing order of Cr(III) < Co(II) < Mn(II) < Cu(II). Basic factors dominating the metal-ion effects were clarified on the basis of the fluorescence quenching as well as radical scavenging abilities of metal ions complexed with humic acids.

Humic Substances↗
PubMed2001

First report of Trichinella nativa in red foxes (Vulpes vulpes schrencki) from Otaru City, Hokkaido, Japan.

Forty-three red foxes (Vulpes vulpes schrencki) and nine raccoon dogs (Nyctereutes procyonoides viverrinus) were captured in Otaru City, Hokkaido, Japan and examined by muscle digestion for the presence of Trichinella sp. larvae. Of the foxes, five (11.6%) were positive for larvae of Trichinella nativa while none of the raccoon dogs were found to be positive. This finding suggests that the red foxes are important reservoir hosts of sylvatic trichinellosis in Otaru, Hokkaido. This is the first report on Trichinella nativa in wild red foxes of Hokkaido, Japan.

Animals↗
PubMed2001

Congestion of superior mesenteric veins and small bowel mucosal injury after endoscopic treatment of esophageal varices in patients with portal hypertension.

We investigated treatment-induced changes in venous return from the small bowel and small bowel intestinal mucosal injury induced by the treatment of esophageal varices in patients with portal hypertension. A total of 14 patients (age 59.8+/-9.5 years, five women and 9 men) who received prophylactic treatment of esophageal varices between December 1998 and March 1999 were investigated. Diamine oxidase (DAO) activity was measured before and after treatment. Changes in blood flow of the portal and superior mesenteric veins were investigated by Doppler ultrasonography in six patients. A significant decrease in DAO activity was observed three days after treatment (11.5+/-1.6 units/liter prior to treatment versus 8.6+/-1.6 units/liter three days after treatment; P < 0.001). Decreases in superior mesenteric and portal venous flow velocity were observed in four and three patients, respectively. In two patients with an increase in the cross-sectional area of the superior mesenteric vein with delayed venous return, a marked decrease in DAO activity was observed three days after treatment. In patients with portal hypertension, rapid reduction of pooling of portal flow caused by the treatment of esophageal varices can induce transient congestion of the mesenteric venous system which can produce some small bowel mucosal injury.

Amine Oxidase (Copper-Containing)↗