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Biomedical subjects

K Ichimura

Publications and source records attributed to K Ichimura.

At least 55 records · Page 3Linked to original sources
PubMed2000

Cryopreservation of viable human glioblastoma xenografts.

Human tumour xenografts maintained in nude mice are a valuable research tool. The passaging and maintenance of human tumour xenografts in immune-deficient animals are expensive and labour-intensive. This study presents a protocol that permits long-term cryopreservation of viable glioblastoma xenograft tissue pieces in liquid nitrogen. Twenty different human glioblastoma xenografts that have been successfully transplanted and repeatedly passaged in nude mice were cryopreserved to validate the method. Different passages were cryopreserved for up to 40 months. On retransplantation of the tumours, all cases except one grew successfully. In order to ensure that the individual tumours did grow (not induced mouse tumours) restriction fragment length polymorphism analysis with variable number of tandem repeats (VNTR) probes was carried out. The method permits the long-term storage of viable, retransplantable glioblastoma xenografts. It minimizes animal use for the maintenance of xenografts and permits cryo-back-up of valuable tumours, thus markedly reducing the cost and increasing the accessibility of human tumour xenografts as a research tool in biology and genetics.

Animals↗
PubMed2000

Various abiotic stresses rapidly activate Arabidopsis MAP kinases ATMPK4 and ATMPK6.

Mitogen-activated protein kinase (MAP kinase, MAPK) cascades play pivotal roles in signal transduction of extracellular stimuli, such as environmental stresses and growth regulators, in various organisms. Arabidopsis thaliana MAP kinases constitute a gene family, but stimulatory signals for each MAP kinase have not been elucidated. Here we show that environmental stresses such as low temperature, low humidity, hyper-osmolarity, touch and wounding induce rapid and transient activation of the Arabidopsis MAP kinases ATMPK4 and ATMPK6. Activation of ATMPK4 and ATMPK6 was associated with tyrosine phosphorylation but not with the amounts of mRNA or protein. Kinetics during activation differ between these two MAP kinases. These results suggest that ATMPK4 and ATMPK6 are involved in distinct signal transduction pathways responding to these environmental stresses.

Abscisic Acid↗
PubMed2000

Two cases of histiocytic necrotizing lymphadenitis (Kikuchi-Fujimoto's disease) following diffuse large B-cell lymphoma.

Histiocytic necrotizing lymphadenitis (HNL) is often mistaken for malignant lymphoma clinically and is also sometimes difficult to differentiate from lymphoma even histopathologically. In this report, we describe the first 2 reported cases of HNL following non-Hodgkin's lymphomas. The patients were 27- and 30-year-old women who developed cervical and axillary lymph node swellings, respectively, in the course of remission of diffuse large B-cell lymphoma. The affected lymph nodes showed the typical histology of HNL: irregular-shaped "necrotic" foci with histiocytes engulfing apoptotic bodies intermingled with large-sized blastic lymphocytes. These findings mimicked the partial involvement of large-cell lymphoma. However, the blastic cells were almost exclusively T cells, and numerous apoptotic bodies were present, which excluded the possibility of recurrence of diffuse large B-cell lymphoma.

Adult↗
PubMed2000

Multiple deleted regions on the long arm of chromosome 6 in astrocytic tumours.

Chromosome 6 deletions are common in human neoplasms including gliomas. In order to study the frequency and identify commonly deleted regions of chromosome 6 in astrocytomas, 159 tumours (106 glioblastomas, 39 anaplastic astrocytomas and 14 astrocytomas malignancy grade II) were analysed using 31 microsatellite markers that span the chromosome. Ninety-five per cent of cases with allelic losses had losses affecting 6q. Allelic losses were infrequent in astrocytomas malignancy grade II (14%) but more usual in anaplastic astrocytomas (38%) and glioblastomas (37%). Evidence for clonal heterogeneity in the astrocytomas and anaplastic astrocytomas was frequently observed (i.e. co-existence of subpopulations with and without chromosome 6 deletions). Clonal heterogeneity was less common in glioblastomas. Five commonly deleted regions were identified on 6q. These observations suggest that a number of tumour suppressor genes are located on 6q and that these genes may be involved in the progression of astrocytic tumours.

Astrocytoma↗
PubMed2000

Mutations of the Pendred syndrome gene (PDS) in patients with large vestibular aqueduct.

A recent report demonstrated the presence of a mutation in the Pendred syndrome gene (PDS) of patients with large vestibular aqueducts but without goitre. We studied PDS mutations in members of four Japanese families, among which five affected members showed bilateral enlarged vestibular aqueducts. All affected members exhibited moderate to severe bilateral fluctuating sensorineural hearing loss and the absence of goitre. Three members also suffered from recurrent episodic vertiginous spells. Analysis of PDS mutation revealed two single base changes (mis-sense mutations) in exons 19 and 10. The first was an A-->G transition at nucleotide position 2168, resulting in a predicted His-->Arg substitution at position 723 (H723R), whereas the second was a C-->T transition at nucleotide position 1229, resulting in a predicted Thr-->Met substitution at position 410 (T410M). Both mutations are situated in the extracellular domain close to the C terminal. It thus appears that PDS mutations can lead not only to classic Pendred syndrome, but also to large vestibular aqueduct syndrome.

Adolescent↗
PubMed2000

The complexity of the 7p12 amplicon in human astrocytic gliomas: detailed mapping of 246 tumors.

Approximately 30%-35% of human glioblastomas have epidermal growth factor receptor (EGFR) gene amplification. Amplicons containing the EGFR gene frequently include several unidentified adjacent genes. Amplification of adjacent genes in the absence of EGFR amplification has been documented. To define the region in detail, we produced a YAC contig map, determining the orientation of the EGFR gene and the general order of 11 STS and EST markers. Seventy-six tumors with amplification of the region were found in a series of 246 human astrocytic gliomas. The amplicons showed amplification of contiguous or noncontiguous loci both telomeric and centromeric to the EGFR gene. Six percent (12/190) of the glioblastomas and 1 anaplastic astrocytomas had amplicons excluding the EGFR gene. These amplicons commonly contain amplified loci telomeric to the EGFR gene. Some of the amplified loci were found to be consistently overexpressed. The findings suggest that there may be other gene target(s) for amplification in the 7p12 region in addition to EGFR.

Astrocytoma↗
PubMed2000

Increased incidence of follicular lymphoma in the duodenum.

The incidence of indolent lymphomas in the lymph nodes and extranodal regions is quite different. Follicular lymphoma (FL) is most common in the nodes, and it seems to be least common in the gastrointestinal (GI) tract, where mucosa-associated lymphoid tissue lymphoma arises most frequently. The authors report that the incidence of FL is unexpectedly high in the duodenum compared with other portions of the GI tract. FL was detected in only eight of 222 cases of GI lymphoma (3.6%). However, five cases of FL arose in the duodenum, which accounted for 38.5% of 13 duodenal lymphomas. Only in two patients did FL arise in either the stomach or the colorectum, and in the remaining patients FL was widespread with lymphomatous polyposis. Duodenal FL was composed of neoplastic follicles with small cleaved cells in dominance, and the immunophenotype of the lymphoma cells was CD10+, BCL-2+, CD20+, CD75+, CD79+, CD3-, CD5-, cyclin D1-, CD23-, and CD45RO-. All the patients were women age 37 to 66 years (average age, 52.4 yrs). In all patients the lymphoma was present around the ampulla of Vater, and four of five patients showed multiple small-size polyps. Although lymphoma cell infiltration was confined to the submucosa in the four patients examined, the regional lymph nodes were involved partially in two patients without distant metastasis. All patients are alive at 2 to 50 months of follow up (average, 27 mos), which is comparable with the prognosis for indolent nodal lymphomas. These results suggest that the duodenum has a distinct background of histogenesis of the lymphomas and that biopsy specimens from the duodenum with multiple polyps should be examined carefully.

Adult↗
PubMed2000

Effect of photoisomerization of azobenzene dopants on the flexoelectric properties of short-pitch cholesteric liquid crystals

The flexoelectric properties of short-pitch cholesteric mixtures doped with three different azobenzenes, 4,4'-dihexyloxyazobenzene (4,4'-azo), 3,3'-dihexyloxy-2,2'-dimethylazobenzene (3,3'-azol), and 3,3'-dihexanoyloxy-2,2'-dimethylazobenzene (3,3'-azo2), respectively, were studied upon illumination with uv light. Their effective flexoelectric coefficients were derived from the flexoelectro-optic response of the mixtures aligned in uniform lying helix texture. Considering the fact that the pitch of the mixtures became shorter upon uv illumination, an increase of their effective flexoelectric coefficients was found to take place due to the photoisomerization of the dyes. The largest change was found for the coefficient of the guest-host mixture containing 4,4'-azo dye, most probably due to the bent shape of the dye cis-isomer. This observation is in good agreement with our previous studies on the influence of the molecular shape on the liquid-crystal flexoelectric properties and it suggests a possible way for enhancement of the amplitude of flexoelectro-optic response in cholesterics by using liquid-crystal materials with pronounced molecular shape dissymmetry.

Journal Article↗
PubMed2000

Changes in epidermal growth factor receptors in olfactory epithelium associated with aging.

To clarify the mechanisms of age-related changes in the olfactory epithelium, we investigated age-related changes in epidermal growth factor receptors (EGFRs) in the epithelium. We examined 3 mice at each of the following stages: embryonal (embryonic days 14 and 16), neonatal (postnatal days 1 and 7), adult (postnatal weeks 5 and 12), and aged (postnatal years 1.5 to 2). The olfactory epithelium of each mouse was stained with sheep anti-human EGFR polyclonal IgG by an immunohistochemical method. The EGFRs were observed in all layers of the olfactory epithelium at the embryonal and neonatal stages. They were identified only in the basal layer of the olfactory epithelium at adult and aged stages, and the number of regions in which EGFRs were identified in the basal layer of the olfactory epithelium decreased in aged mice compared to adult mice. We believe that a decrease in EGFRs in the olfactory epithelium induces the inhibition of cell proliferation, with resultant atrophy of the olfactory epithelium.

Aging↗
PubMed2000

Proliferation markers, proliferating cell nuclear antigen, Ki67, 5-bromo-2'-deoxyuridine, and cyclin D1 in mouse olfactory epithelium.

We immunohistochemically identified proliferating cells in the olfactory epithelium of mice, using an anti-proliferating cell nuclear antigen (PCNA) antibody, an anti-Ki67 antibody, an anti-5-bromo-2'-deoxyuridine (BrdU) antibody, and an anti-cyclin D antibody. Positive cells stained by the 4 antibodies were identified mainly in the basal layer. The mean numbers of positive cells stained by the 4 antibodies in 500 olfactory epithelium cells from each animal were as follows: PCNA-positive cells 42, Ki67-positive cells 23, BrdU-positive cells 13.7, and cyclin D1-positive cells 9.2. PCNA may be detected in both proliferating and resting cells. Ki67 is an intranuclear antigen expressed in proliferating, but not resting, cells. Anti-BrdU antibodies might stain proliferating cells only following the S-phase, but not the G1-phase. Cyclin D1 is a protein that works during the G1-phase of the cell cycle. When we stain proliferating cells using proliferating cell markers, it is important to consider the cell cycle phases during which each marker stains.

Animals↗
PubMed2000

Identification of L-inositol and scyllitol and their distribution in various organs in chrysanthemum.

Two unidentified soluble carbohydrates were isolated from chrysanthemum (Dendranthema x grandiflorum (Ramat.) Kitamura) leaves using HPLC. The compounds were identified as 1 L-chiro-inositol, called L-inositol (1) and scyllo-inositol, called scyllitol (2) from the results of 1H-NMR, 13C-NMR, and CI-MS spectra. L-Inositol and scyllitol were distributed in four cultivars tested. L-Inositol concentration of petals gradually decreased during the flower bud development, but the L-inositol content increased by about 7 times. Scyllitol was detected only at an early stage of flower bud.

Carbohydrate Metabolism↗
PubMed2000

[Bilateral facial palsy in a patient with human immunodeficiency virus infection--a case report].

We report a 37-year-old male with bilateral peripheral facial palsy associated with HIV infection. He was serologically tested for HIV and was found to be positive (by Western blot and ELISA). Serum chemistry studies showed elevated HIV RNA and were negative for p24 antigen. The CD4+ count was 533 cells x 10(6) per liter, with a CD4+:CD8+ ratio of 0.47. Since there was no evidence of any other underlying systemic illness, his facial palsy was considered to be secondary to HIV infection.

Adult↗
PubMed2000

[Chemotherapy for unresectable recurrent or metastatic squamous cell carcinomas of the head and neck].

The efficacy of chemotherapy for unresectable recurrent or metastatic squamous cell carcinomas of the head and neck can not be proved by survival periods. However, the efficacy of chemotherapy has been observed in some select patients. We investigated the effect of chemotherapy for unresectable recurrent squamous cell carcinomas of the head and neck. Four patients with a good performance status (PS) were treated with high-doses of leucovorin (LV), cisplatin (CDDP), and 5-fluorouracil (5-FU). The regimen consisted of 25 mg/m2 of CDDP on days 1-5; 600 mg/m2 of 5-FU of days 2-6; and 200 mg/m2 of LV on days 1-6. Patients received 3 cycles of this regimen at 28-day intervals. Ten patients with a poor PS were treated with low-doses of CDDP and tegafur.uracil upon admission. The regimen of seven poor PS patients consisted of 8 mg/m2 of CDDP on days 1-5 and 8-12, and 400 mg/body of tegafur.uracil administered orally on days 1-14. The other three patients received chemotherapy on an outpatient basis for ten weeks. The weekly regimen consisted of 7.5 mg/m2 of CDDP on days 3 and 6 and 400 mg/body of tegafur.uracil administered orally on days 1-7. With respect to the LV + CDDP and 5-FU treatment, complete remission was obtained in one patient. Two patients showed no change (NC), while one patient developed a progressive disease (PD). This regimen is highly toxic, has severe side effects including myelosuppression, oral mucositis, and diarrhea, and has a survival period of between 16 and 32 weeks. The low-dose CDDP + tegafur.uracil treatment produced a partial response in three patients, NC in three patients, and four patients developed a PD. This regimen doses not have any severe side effects and has a survival period of between 4 and 67 weeks.

Aged↗
PubMed2000

[Ki-1 lymphoma].

ALCL is widely recognized with its broad morphologic and phenotypic spectrum causing controversy in the diagnosis of this peculiar neoplasm. It is now beyond doubt that a significant proportion(64 to 84%) of the cases diagnosed as ALCL is closely associated with the expression of chimeric NPM-ALK protein activated by the (2;5) (p23;q35) chromosomal translocation, which can be detected by anti-p80NPM/ALK or ALK1 antibodies. Recently, some investigators including us asserted that these p80NPM/ALK or ALK1-positive(p80/ALK+) ALCLs represent a distinct genetic entity with occurrence in young patients and a favorable prognosis, and should be differentiated from the p80/ALK- tumors with the relatively aggressive clinical course. The p80/ALK+ lymphomas also revealed the characteristic morphology such as horseshoe-like, kidney-like or doughnut-like nuclei and frequent expression of EMA and cytotoxic molecules. However, these features are shared, though to a lesser degree, by other p80/ALK-negative lymphoid neoplasms. Indeed, it is indicated that cytotoxic ALCL cases may be either p80/ALK positive or negative, suggesting that the cytotoxicity and expression of p80/ALK are independent phenomena among the cases of ALCL of T- and null-cell type. Thus, several areas of disagreement and controversy that surround the diagnosis and categorization of ALCL remain.

Biomarkers, Tumor↗
PubMed2000

[Effect of a leukotriene antagonist, pranlukast hydrate, on exercise-induced asthma for 14 days].

Exercise is a common stimulus of bronchoconstriction in subjects with asthma. Exercise-induced asthma (EIA) may be caused by heat loss and/or water loss during exercise. These changes cause the release of mediators and the development of bronchoconstriction. Recent studies have implicated the cysteinyl leukotrienes in the pathogenesis of EIA. Therefore we investigated the effect of a leukotriene antagonist, pranlukast hydrate, on EIA. Subjects were 11 EIA positive patients and were all atopic type bronchial asthma. 450 mg of pranlukast hydrate was given for 14 days and the exercise test was performed before and after treatment. Pulmonary function tests were done before and 0, 5, 15 and 30 min after completion of the each exercise. Prostaglandin E2, thromboxane B2, leukotriene E4 and B4 in urine were measured before and after the treatment. Pranlukast hydrate did not affect FEV1.0, PF and Flow volume curve at rest and also levels of mediators in urine. The mean maximal percentage fall in FEV1.0 after exercise was--54.9 +/- 5.7% without therapy and--30.1 +/- 7.5% after pranlukast hydrate therapy. There was a significant difference between FEV1.0 values before and treatment at each time (p < 0.05). This study demonstrated that pretreatment with a potent and selective leukotriene antagonist, pranlukast hydrate, attenuated EIA, and it suggests that leukotriene plays a role in EIA.

Adult↗
PubMed2000

[A case of tuberculous aneurysm of the aorta].

We reported a rare case of tuberculous aneurysm of the aorta managed successfully with urgent surgical therapy. A 35-year-old woman was admitted to our hospital complaining of fatigue and hemoptysis. Laboratory tests showed severe anemia, slight liver dysfunction, elevated level of C-reactive protein, and negative syphilis serologies. The chest roentgenogram revealed widening of right upper mediastinum, two nodular shadows in right middle lobe, and left-sided infiltration shadow with pleural effusion. The pleural effusion was bloody and its level of adenosine deaminase was normal. Culture of pleural effusion specimen remained negative. A computed tomography scans of the chest revealed an aortic aneurysm on the aortic hiatus. Rapid increase in pleural effusion was followed by hemothorax a few hours later. After operation, she received antituberculosis therapy. Histopathologically, the resected lung showed inflammatory process including granulation of giant cells and epithelioid cells. The specimens of the aortic aneurysm revealed rupture of whole layer of aortic wall and inflammatory cell infiltrations. These findings suggested that the case to be a tuberculous aneurysm of the aorta. Therefore, we diagnosed the case as the rupture of tuberculous aneurysm of the aorta.

Adult↗
PubMed1999

Evaluation of a cDNA scanning method concerning the fidelity and efficiency of cDNA selection using the YAC CIC3B1-S region of Arabidopsis thaliana chromosome 5.

We previously reported a cDNA selection method using DNA latex particles to identify expressed genes in specific regions of genomes and named this cDNA scanning method (Hayashida et al., 1995 Gene 155 161). We applied the cDNA scanning method to the YAC CIC3B1-S DNA on Arabidopsis thaliana chromosome 5, and constructed a region-specific sublibrary in which cDNAs for genes on the YAC CIC3B1-S DNA were concentrated. We isolated 545 cDNA clones from the sublibrary, and determined partial sequence of them to produce expressed sequence tags (ESTs) derived from the YAC region. In total, 74 nonredundant groups of cDNAs were obtained from 545 cDNA clones. Forty-seven percent of these EST clones had significant homology to functional proteins such as protein kinases, LON protease, nucleic acid binding protein and chloride channel protein. We compared the cDNA sequences isolated by the cDNA scanning method to the Arabidopsis genomic sequence corresponding to the YAC CIC3B1-S region, and found that 69% of the selected cDNAs are located in the region. We discuss the fidelity and efficiency of the cDNA scanning method for cloning region-specific cDNAs and its useful application in positional cloning.

Arabidopsis↗