Biomedical subjects

K Uchida

Publications and source records attributed to K Uchida.

At least 145 records · Page 8Linked to original sources

PubMed2001

Characterization of mumps virus isolated in saitama prefecture, Japan, by sequence analysis of the SH gene.

Mumps virus (MuV) strains isolated from cerebrospinal fluid and throat swabs from patients in Saitama Prefecture and Tokyo, Japan, from 1997 to 2000 were examined by analyzing the SH gene nucleotide sequence (316-nt). Eighteen of the 20 strains studied were divided into three genotypes, recognized as B, G, and H in previous reports. Two genotypes (G and H) are believed to be new in Japan. Two of the 20 strains belonged to none of the previously reported genotypes (A-I), but were closely related to two known strains, MP94-H and Loug1/UK97. We propose that the two strains identified in this study together with the previously reported strains, MP94-H and Loug1/UK97, form a new genotype, designated J, based on the divergence of the SH gene nucleotide sequences between these four strains and other strains reported (genotypes A-I). Our results also suggest that more than two genotypes circulated in Saitama Prefecture from 1997 to 1999, but only one, genotype G, was in evidence in 2000. Genotype B was earlier reported as the predominant strain in Japan, but it became undetectable by the year 2000. These results provide important epidemiological data on mumps in Japan.

Amino Acid Sequence↗

PubMed2001

Effect of sealing and Tween 80 on the antifungal susceptibility testing of essential oils.

Concentrations of essential oils showing high volatility decreased substantially in broth and agar media when incubated under open conditions. The decrease in the half life was from 0.7 to 38 hr in broth medium at 27 C. When evaporation was prevented by sealing, MIC values against Aspergillus fumigatus, Candida albicans and Trichophyton mentagrophytes by broth or agar dilution assay were lowered two to eight-fold, as compared with those obtained under open conditions. Addition of Tween 80 caused a rise of the MICs against A. fumigatus by two to four-fold in broth dilution assay, but little affected the MICs in agar dilution assay.

Antifungal Agents↗

PubMed2001

Cluster analysis of human and animal pathogenic Microsporum species and their teleomorphic states, Arthroderma species, based on the DNA sequences of nuclear ribosomal internal transcribed spacer 1.

We performed a cluster analysis of human and animal pathogenic Microsporum species and their teleomorphic states, Arthroderma species, including A. otae-related species (M. canis, M. audouinii, M. distortum, M. equinum, M. langeronii, and M. ferrugineum) and M. gypseum complex (A. fulvum, A. gypseum, and A. incurvatum) using DNA sequences of nuclear ribosomal internal transcribed spacer 1 (ITS1). The dendrogram showed the members of A. otae-related species to be monophyletic and to construct an extremely closely related cluster with a long horizontal branch. This ITS1-homologous group of A. otae was organized in 6 unique genotypes, while sequences of the members of the ITS1-homologous group of M. gypseum complex are more diverse. This ITS1-based database of Microsporum species and their teleomorphic states will provide a useful and reliable species identification system: it is time-saving (takes two to three days), accurate and applicable even to strains with atypical morphological features or in a non-culturable state.

Animals↗

PubMed2001

Fungal flora on board the Mir-Space Station, identification by morphological features and ribosomal DNA sequences.

This report is on the morphological and molecular biological identification, using 18S- and ITS1-rDNA sequences, of the "space fungi" isolated on board the Russian Mir-Space Station as the major constituents of the fungal flora. The six fungal strains were isolated from air by using an air sampler or from condensation. Strains were identified as Penicillium chrysogenum, Aspergillus versicolor, or Penicillium sp. by both methods. The species of space fungi were common saprophytic fungi in our living environment, potential pathogens, and allergens. This study concluded that the environment on board the space station Mir allows the growth of potentially pathogenic fungi as true in residential areas on the earth. Therefore, to prevent infection or other health disorders caused by these fungi, easy and reliable methods should be established to survey the fungal flora in a space station.

Aspergillus↗

PubMed2001

Cell-free entry of human T-cell leukemia virus type 1 to mouse cells.

Human T-cell leukemia virus type 1 (HTLV-1) is the etiologic agent for adult T-cell leukemia and HTLV-1-associated myelopathy / tropical spastic paraparesis. Recently we infected newborn mice by inoculating HTLV-1-producing human cells, and found that T-cells, B-cells and granulocytes were infected in vivo. To understand the mechanism of viral-cell interaction and the pathogenesis of HTLV-1 using the mouse model, it is important to clarify the cellular tropism using a cell-free HTLV-1 transmission system. We employed a highly transmissible cell-free HTLV-1 produced by a feline kidney cell line, c77, and studied the susceptibility of 9 kinds of mouse cell lines, EL4, RLm1, CTLL-2, J774.1, DA-1, Ba / F3, WEHI-3, NIH3T3 and B1, and two kinds of human cell lines, Molt-4 and Hut78. HTLV-1 proviral sequence was found by PCR in all 9 mouse cell lines as well as in 2 human cell lines and viral entry was blocked with sera from an HTLV-1 carrier and an adult T-cell leukemia patient. Unexpectedly, mouse cell lines EL4 and RLm1 and human cell lines Molt-4 and Hut78 showed similar efficiency for viral entry. These results suggest a wide distribution of HTLV-1 receptor in mouse cells.

3T3 Cells↗

PubMed2001

[Characterization of enterovirus type 71 isolated in Saitama Prefecture in 2000].

Coxsackievirus A16 (CA16) has been isolated mainly from hand, foot and mouth disease patients for the past several years in Saitama Prefecture, Japan, but in 2000, enterovirus 71 (EV71) was isolated with high frequency. Also, many cases with aseptic meningitis were reported unusually. We determined partial nucleotide sequences of EV71 isolated in this year and compared them with those of the viruses isolated previously. Eighteen strains of EV71 were isolated from May to September in 2000. The sequence analysis of about 700 nucleotides between 5' NCR and VP2 region indicated that the EV71 strains isolated in Saitama Pref. in 2000 were classified into three groups. The first group was consisted of the strains which showed 89 to 91% nucleotide similarity with TW/2086/98, NCKU 9822 isolated in Taiwan and strain SA/448/99 isolated in Saitama Pref. in 1999. The second group was highly similar to both Taiwan strains and SA/448/99 (92 to 93% nucleotide similarity). The first and second groups were also considered to be subgroups belonging to the same group. And the third group was highly similar to 18/Sin/97, 13/Sin/98 isolated in Singapore. These viruses were genetically close to MS7423/87, which has shown neurovirulence. Furthermore, from geographical origin of specimens, we found that the Taiwan like strains were isolated in the west area (Kawagoe, Tokorozawa) and Singapore like strains were isolated in the south area (Urawa, Kawaguchi, Toda). Also, almost every EV71 strains isolated from the patient with aseptic meningitis were close to Singapore strains. It was found that EV71 strains isolated in 2000 were different from the strains isolated past in Saitama Pref. and some of them were close to the neurovirulent strain.

Base Sequence↗

PubMed2001

Analysis of cytokines in the early development of gastric secondary lymphoid follicles in Helicobacter pylori-infected BALB/c mice with neonatal thymectomy.

Immunological interaction between the host and Helicobacter pylori seems to play a critical role in follicular formation in gastric mucosa. We reported H. pylori-induced follicular gastritis model using neonatally thymectomized mice. In this study, we investigated the involvement of various cytokines in this model. BALB/c mice were thymectomized on the third day after birth (nTx). At 6 weeks old, these mice were orally infected with H. pylori. Histological studies showed that follicular formation occurred from 8 weeks after the infection and that most of the infiltrating lymphocytes were CD4(+) and B cells. Neutrophils increased transiently at 1 week after the infection. Gamma interferon, interleukin-7 (IL-7), and IL-7 receptor were expressed in the stomach of the nTx mice irrespective of the infection. In contrast, expressions of the tumor necrosis factor alpha, IL-4 and lymphotoxin-alpha genes were remarkably upregulated by the infection. Our findings suggest that follicular formation may require cooperative involvement of a Th2-type immune response, tumor necrosis factor alpha and lymphotoxin-alpha in addition to the Th1-type immune response in H. pylori-induced gastritis in nTx mice.

Animals↗

PubMed2001

Human T-cell leukemia virus type 1 (HTLV-1) infection of mice: proliferation of cell clones with integrated HTLV-1 provirus in lymphoid organs.

Human T-cell leukemia virus type 1 (HTLV-1) is suggested to cause adult T-cell leukemia after 40 to 50 years of latency in a small percentage of carriers. However, little is known about the pathophysiology of the latent period and the reservoir organs where polyclonal proliferation of cells harboring integrated provirus occurs. The availability of animal models would be useful to analyze the latent period of HTLV-1 infection. At 18 months after HTLV-1 infection of C3H/HeJ mice inoculated with the MT-2 cell line, which is an HTLV-1-producing human T-cell line, HTLV-1 provirus was detected in spleen DNA from eight of nine mice. No more than around 100 proviruses were found per 10(5) spleen cells. Cellular sequences flanking the 3' long terminal repeat (LTR) and the clonalities of the cells which harbor integrated HTLV-1 provirus were analyzed by linker-mediated PCR. The results showed that the flanking sequences are of mouse genome origin and that polyclonal proliferation of the spleen cells harboring integrated HTLV-1 provirus had occurred in three mice. A sequence flanking the 5' LTR was isolated from one of the mice and revealed the presence of a 6-nucleotide duplication of cellular sequences, consistent with typical retroviral integration. Moreover, PCR was performed on DNA from infected tissues, with LTR primers and primers derived from seven novel flanking sequences of the three mice. Data revealed that the expected PCR products were found from lymphatic tissues of the same mouse, suggesting that the lymphatic tissues were the reservoir organs for the infected and proliferating cell clones. The mouse model described here should be useful for analysis of the carrier state of HTLV-1 infection in humans.

Animals↗

PubMed2001

Oxidative and nitrosative stress in acute renal ischemia.

Generation of reactive oxygen species and nitric oxide in hypoxia-reperfusion injury may form a cytotoxic metabolite, peroxynitrite, which is capable of causing lipid peroxidation and DNA damage. This study was designed to examine the contribution of oxidative and nitrosative stress to the renal damage in ischemic acute renal failure (iARF). iARF was initiated in rats by 45-min renal artery clamping. This resulted in lipid peroxidation, DNA damage, and nitrotyrosine modification confirmed both by Western and immunohistochemical analyses. Three groups of animals were randomly treated with an inhibitor of inducible nitric oxide synthase (NOS), L-N(6)-(1-iminoethyl)lysine (L-Nil), cell-permeable lecithinized superoxide dismutase (SOD), or both. Each treatment resulted in amelioration of renal dysfunction, as well as reduced nitrotyrosine formation, lipid peroxidation, and DNA damage, thus suggesting that peroxynitrite rather than superoxide anion is responsible for lipid peroxidation and DNA damage. Therefore, in a separate series of experiments, a scavenger of peroxynitrite, ebselen, was administered before the reperfusion period. This treatment resulted in a comparable degree of amelioration of iARF. In conclusion, the present study provides the first attempt to elucidate the role of peroxynitrite in initiation of the cascade of lipid peroxidation and DNA damage to ischemic kidneys. The results demonstrate that L-Nil, lecithinized SOD, and ebselen treatments improve renal function due to their suppression of peroxynitrite production or its scavenging, consequently preventing lipid peroxidation and oxidative DNA damage.

Animals↗

PubMed2001

AgNOR count in resting cells (resting NOR) is a new prognostic marker in invasive bladder tumor.

PURPOSE: We have previously demonstrated that the AgNOR count in proliferating cells is a predictor of tumor recurrence in superficial bladder tumor (J. Urol. 162 (1999), 63-68). In the present study, we evaluate the type of AgNOR associated with cell cycles as a prognostic factor in invasive bladder tumor using a double staining technique employing both AgNOR and MIB-1 labelling. MATERIALS AND METHODS: Forty-four paraffin sections of invasive bladder tumors were stained simultaneously with AgNOR and MIB-1. The number of AgNORs in proliferating (MIB-1 positive) or resting (MIB-1 negative) cells were counted from a total of 100 nuclei. Correlations between MIB-1 associated AgNOR count and clinicopathological parameters were statistically analyzed. RESULTS: The AgNOR count in proliferating cells (proliferating NOR) was significantly higher than that in resting cells (resting NOR) (p<0.01). The resting NOR in tumors with distant metastases was significantly higher than that in tumors without metastases (p<0.05). Patients with a low resting NOR tumor had a better prognosis than those with a high resting NOR tumor, whereas the proliferating NOR was not associated with survival. Survival analysis revealed that the resting NOR was the most powerful prognostic marker in patients with invasive bladder tumor (p<0.05). CONCLUSIONS: Resting NOR had a predictive value in the prognosis of patients with invasive bladder tumor.

Adult↗

PubMed2001

Identification of T helper cell subsets in continuous ambulatory peritoneal dialysis patients.

BACKGROUND/AIM: End-stage renal failure induces a clinical state of immunodeficiency with a higher incidence of infections and a higher mortality due to infectious complications as compared with the normal population. A crucial element in this immune response is the development of a network of cytokines. CD4-positive T helper (Th) cells differentiate into either Th1 or Th2 cells in response to various stimuli. It is important to examine whether the impaired immune responses in patients with end-stage renal disease are due to an enhanced Th1 response or a reduced number of Th2 cells. METHOD: Using a newly developed immunofluorescence staining of intracellular cytokines for flow cytometric analysis, we studied Th subsets in 24 patients on continuous ambulatory peritoneal dialysis (CAPD). RESULTS: The proportions of Th1 cells did not differ between CAPD patients (18.7 +/- 1.8%) and controls (19.6 +/- 1.5%). Unlike Th1 cells, a significantly higher proportion of CD4 cells in CAPD patients is characterized by a Th2-type cytokine secretion pattern as compared with healthy controls: 2.9 +/- 0.8% versus 1.7 +/- 0.4%. CONCLUSION: These data demonstrate that Th cells from CAPD patients manifest a dysregulated differentiation profile characterized by a major increase in the percentage of Th2 cells and by a normal percentage of Th1 cells.

Flow Cytometry↗

PubMed2001

Soluble osteopontin and vascular calcification in hemodialysis patients.

BACKGROUND: Vascular calcification often occurs in patients with uremia. As osteopontin (OPN) is not only involved in the physiological but also the pathological calcification of tissues, OPN may be associated with the pathogenesis of aortic calcification in hemodialysis (HD) patients. METHODS: We examined the expression of OPN in atherosclerotic aortas of HD patients. In addition, we performed a prospective longitudinal study by using CT scans to detect aortic calcifications and by measuring the plasma OPN concentration by ELISA in HD patients (20 men, 16 women; mean age 55.2 +/- 21.3 years) and in healthy volunteers (18 men, 17 women; mean age 54.0 +/- 13.2 years). RESULTS: By immunohistochemical staining, OPN was abundantly localized in atherosclerotic plaques of HD patients. The macrophages surrounding the atheromatous plaques were identified as the OPN-expressing cells. We furthermore found that the concentration of soluble plasma OPN was significantly higher in HD patients as compared with the concentrations in age-matched healthy volunteers (837.3 +/- 443.2 vs. 315.1 +/- 117.4 ng/ml, p < 0.01). The OPN concentration was positively correlated with the aortic calcification index in HD patients (r = 0.749, p < 0.01). CONCLUSION: These data suggest that OPN, secreted by macrophages, plays a role in the calcification of atheromatous plaques in HD patients.

Adult↗

PubMed2001

In vivo complex formation of oxidized alpha(1)-antitrypsin and LDL.

An inactivated form of alpha(1)-antitrypsin (AT) and LDL coelutes in gel permeation chromatography. To characterize and to quantify the amount of this fraction of AT, a monoclonal antibody was established against chloramine T-oxidized AT and named OxAT-4. OxAT-4 recognized the oxidatively modified AT, including hexylaldehyde- or 4-hydroxy-2-nonenal-modified AT, but neither normal active AT nor trypsin/AT complex. Comigration of apoB and oxidized AT was demonstrated by Western blotting analysis of AT-LDL by means of anti-apoB monoclonal antibody and OxAT-4. A complex of oxidized AT and LDL (AT-LDL) was isolated from human plasma LDL by affinity column with an OxAT-4 antibody-coated carrier. AT-LDL was degraded 4 times more effectively by mouse peritoneal macrophages, but this was not mediated by scavenger receptor class A type I. Localization of AT-LDL was detected in human atherosclerotic lesions of the coronary artery, but distribution of it was not completely identical to that of macrophages. In situ hybridization revealed AT expression by macrophages, which were present in intimal layers of the coronary artery. From these findings, we concluded that AT is produced and oxidized by macrophages, then attached to LDL in the intimal layer of the arterial wall. Although AT-LDL that escapes into the blood stream can be cleared by hepatocytes, the remaining AT-LDL may be taken up by macrophages and contribute to the lipid accumulation in arterial wall cells as the early stage of atherogenesis.

Animals↗

PubMed2001

Transglycosylation to ginseng saponins by cyclomaltodextrin glucanotransferases.

Ten new alpha-glucosylginsenosides were found to be synthesized from dextrin and four ginsenosides, -Rb1, -Rc, -Re, and -Rg1, by the successive actions of B. stearothermophilus cyclomaltodextrin glucanotransferase and Rhizopus glucoamylase. Seven of them were isolated in the pure state by extraction with n-butanol saturated with water, silica gel column chromatography, and high pressure liquid chromatography, and identified as 3-O-[alpha-D-glcp-(1-->4)-beta-D-glcp-(1-->2)-beta-D-glcp]-20-O-[beta-D-glcp-(1-->6)-beta-D-glcp]-20(S)-protopanaxadiol, 3-O-[beta-D-glcp-(1-->2)-beta-D-glcp]-20-O-[alpha-D-glcp-(1-->4)-beta-D-glcp-(1-->6)-beta-D-glcp]-20(S)-protopanaxadiol, 3-O-[alpha-D-glcp-(1-->4)-beta-D-glcp-(1-->2)-beta-D-glcp]-20-O-[alpha-L-araf-(1-->6)-beta-D-glcp]-20(S)-protopanaxadiol, 3-O-[beta-D-glcp-(1-->2)-beta-D-glcp]-20-O-[(4G-alpha-D-glcp)-alpha-L-araf-(1-->6)-beta-D-glcp]-20(S)-protopanaxadiol, 6-O-[alpha-L-rhap-(1-->2)-beta-D-glcp]-20-O-[alpha-D-glcp-(1-->4)-beta-D-glcp]-20(S)-protopanaxatriol, 6-O-[alpha-D-glcp-(1-->4)-beta-D-glcp]-20-O-(beta-D-glcp)-20(S)-protopanaxatriol, and 6-O-[alpha-D-glcp-(1-->3)-beta-D-glcp]-20-O-(beta-D-glcp)-20(S)-protopanaxatriol, by spectroscopy (FAB-MS, IR, 1H-NMR and 13C-NMR) and hydrolysis products in 50% acetic acid. The bitterness of these alpha-glucosyl-ginsenosides was less than that of ginsenosides.

Chromatography, High Pressure Liquid↗

PubMed2001

A case of canine primitive neuroectodermal tumor (PNET).

A 2-year and 6 month-old, female, Golden Retriever showed circling behavior and seizure. By magnetic resonance imaging (MRI) examination, a mass was found on the surface of the left cerebral hemisphere, invading to the left temporal muscle. The skull bone between them was destroyed. The dog was euthanized and necropsied. Histologically, the mass contained a lot of undifferentiated anaplastic cells, forming Homer-Wright rosettes and pseudopalisading patterns. Thus, the case was diagnosed as primitive neuroectodermal tumor (PNET).

Animals↗

PubMed2001

Amebiasis in four ball pythons, Python reginus.

Between September 13th and November 18th in 1999, four ball pythons, Python reginus kept in the same display, showed anorexia and died one after another. At necropsy, all four snakes had severe hemorrhagic colitis. Microscopically, all snakes had severe necrotizing hemorrhagic colitis, in association with ameba-like protozoa. Some of the protozoa had macrophage-like morphology and others formed protozoal cysts with thickened walls. These protozoa were distributed throughout the wall in the large intestine. Based on the pathological findings, these snakes were infested with a member of Entamoeba sp., presumably with infection by Entamoeba invadens, the most prevalent type of reptilian amoebae.

Animals↗

PubMed2001

A mucinous histochemical study on malignancy of aberrant crypt foci (ACF) in rat colon.

The relationship between malignancy and number of crypts (crypt multiplicity) comprising aberrant crypt foci (ACF) was investigated, by studying changes in the mucous nature of ACF with 5 crypts or less, ACF with 6-13 crypts, adenomas and invasive adenocarcinomas induced by 1,2-dimethylhydrazine in distal colon of rats. A paradoxical Con A-staining was performed for goblet cell mucins. Of the sulfomucin-dominant ACF with 1-3 crypts, 82.6% had labile class III mucin, similar to the distal colon in the normal rats. However, in most of the goblet cell mucin produced by the ACF with 4-5 crypts with an indicated relation to colorectal carcinoma or the sialomucin (SiM) -dominant ACF with 1-3 crypts, mucin types other than class I were rarely present. The incidence of class I mucin decreased with the increase in crypt multiplicity of ACF or in the degree of histological malignancy, with the lowest incidence of 40% in adenocarcinomas. In contrast, the incidence of class II mucin increased markedly with the increase in crypt multiplicity of ACF or in the degree of histological malignancy, with the highest incidence in adenocarcinomas (95%). The ACF with 6-13 crypts had a mucous profile similar to that of adenomas. These results suggested that malignancy of ACF related to the crypt multiplicity. In the ACF with 1-3 crypts, SiM-dominant ACF had the potential to progress to malignant lesions.

Adenocarcinoma, Mucinous↗

PubMed2001

Diffuse bilateral hemangiosarcoma of the uterus in a dog.

A 15-year-old female mongrel dog showed abdominal swelling, marked hemorrhagic ascites and vulvar discharge, and ovariohysterectomy was performed. Grossly, the uterus was enlarged bilaterally without apparent mass formation. Histologically, the uterine muscular wall was composed of proliferated sinusoidal vessels. In some areas, irregular and small vessels proliferated markedly, while in others, pleomorphic and atypical tumor cells forming irregular vascular structures were predominant. From these findings, the case was diagnosed as diffuse bilateral hemangiosarcoma of the uterus that invaded to the ovary and broad ligament. The relationship between the tumor and angiomatosis was discussed.

Animals↗