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Biomedical subjects

Y Uchida

Publications and source records attributed to Y Uchida.

At least 55 records · Page 3Linked to original sources
PubMed2002

Invasive pulmonary aspergillosis resulting in respiratory failure during neutrophil recovery from postchemotherapy neutropenia in three patients with acute leukaemia.

Respiratory failure is a severe complication of invasive pulmonary aspergillosis (IPA). Its pathogenesis is not well understood. We herein describe three cases of subacute respiratory failure that occurred during the recovery phase of neutropenia following induction chemotherapy for acute leukaemia with IPA. In each case, severe neutropenia (19-85 days), high-grade fever, severe anaemia, the use of granulocyte-colony-stimulating factor and increasing infusion volume were noted. As the neutrophil count was recovering, the shadows on the chest X-ray expanded with progressing hypoxia. We should pay attention to the respiratory failure during the recovery phase of neutropenia in patients with IPA.

Acute Disease↗
PubMed2002

Radial closing wedge osteotomy for Kienböck's disease: an over 10 year clinical and radiographic follow-up.

Thirteen patients with Kienböck's disease who had undergone a radial closing wedge osteotomy were reviewed clinically and radiologically at a follow-up mean of 14 years. Good long-term results were obtained in all patients. Their levels of pain were improved, and significant increases were seen in the range of motion and grip strength. Radiographic stage, as assessed by Lichtman's classification, improved in one, did not change in four, and advanced in eight patients. The radial inclination angle significantly decreased and the carpal-ulnar distance and lunate covering ratios both increased, demonstrating that radial shift in the alignment of the carpal bones occurs and that the joint contact area of the lunate increases in proportion to the decrease in radial inclination. The preoperative radiolunate and radioscaphoid angles, which were significantly larger than those of the unaffected wrist, did not change postoperatively which shows that this technique was not able to correct the flexion deformity of the lunate and the scaphoid.

Adolescent↗
PubMed2002

Preferential transcription of a gene for alpha amylase in the carcinoid tumor of African rodent Mastomys natalensis.

The carcinoid tumor in Mastomys natalensis provides a useful animal model of tumorigenesis. We investigated preferentially transcribed genes in this carcinoid tumor by differential hybridization. Fourteen clones corresponding to high levels of transcription were isolated from a cDNA library. Sequencing analysis and a homology search revealed that the clones corresponded to genes for chromogranin and alpha-amylase. High-level transcription of a gene for alpha-amylase gene in Mastomys carcinoid tumor was confirmed by Northern blotting analysis. Furthermore, Western blotting analysis confirmed the expression of alpha-amylase in tumors at the protein level. Immunohistochemical staining revealed alpha-amylase in the cytoplasm of Mastomys carcinoid tumors. Our results demonstrated that an exocrine enzyme 'amylase' could be produced ectopically by a neuroen docrine tumor.

Africa↗
PubMed2001

Fusion of ETV6 to fibroblast growth factor receptor 3 in peripheral T-cell lymphoma with a t(4;12)(p16;p13) chromosomal translocation.

Fusions of the ETV6/TEL gene to receptor or protein tyrosine kinases (TKs), such as PDGFRbeta, JAK2, ABL, ABL2, TRKC, and Syk, have been reported in various hematological malignancies. Expression of the resultant chimeric proteins is believed to lead to constitutive TK activity through activation by the helix-loop-helix (HLH) domain of ETV6. We identified a novel ETV6 partner gene, fibroblast growth factor receptor 3 (FGFR3), in a patient with peripheral T-cell lymphoma (PTCL) with a t(4;12)(p16;p13) translocation. The ETV6-FGFR3 transcript showed a fusion of exon 5 of ETV6 to exon 10 of FGFR3, resulting in an open reading frame for a chimeric protein consisting of the HLH domain of ETV6 and the TK domains of FGFR3. This is the first report of ETV6 and FGFR3 involvement in PTCL.

Amino Acid Sequence↗
PubMed2001

ABCA3 is a lamellar body membrane protein in human lung alveolar type II cells.

The ABCA3 gene, of the ABCA subclass of ATP-binding cassette (ABC) transporters, is expressed exclusively in lung. We report here the cloning, molecular characterization, and distribution of human ABCA3 in the lung. Immunoblot analysis using the specific antibody reveals a 150-kDa protein in the crude membrane fraction of human lung. Immunohistochemical analyses of alveoli show that ABCA3 is expressed only in the type II cells expressing surfactant protein A. At the ultrastructural level, ABCA3 immunoreactivity was detected mostly at the limiting membrane of the lamellar bodies. Since members of the ABCA transporter family are known to be involved in transmembrane transport of endogenous lipids, our findings suggest that ABCA3 plays an important role in the formation of pulmonary surfactant in type II cells.

ATP-Binding Cassette Transporters↗
PubMed2001

Exposure to diesel exhaust exacerbates allergen-induced airway responses in guinea pigs.

Diesel exhaust (DE) is a major air pollutant in urban areas. To clarify the effects of DE on the exacerbation of asthma, guinea pigs were exposed 12 h daily to 3 mg/m(3) DE or air for 8 wk with or without sensitization to ovalbumin (OVA). In the DE-exposed sensitized animals, both immediate (IAR) and late (LAR) airway responses were enhanced after the inhalation challenge by OVA, compared with the DE-unexposed sensitized animals. Mucus was greatly accumulated in the airways of DE-exposed sensitized animals during IAR. The number of eosinophils and level of sialic acid concentration in bronchial lavage fluids were also significantly higher in the DE-exposed sensitized animals than in the DE-unexposed control animals. During LAR, intercellular spaces of the bronchial epithelium became enlarged in the DE-exposed sensitized animals, showing infiltration by numerous eosinophils. Albumin concentration was significantly higher in the bronchial lavage fluids from the DE-exposed sensitized animals than in those from the DE-unexposed control animals. These results suggest that exposure to DE enhances mucus hypersecretion and eosinophilic inflammation during IAR. DE exposure also increases airway permeability and airway inflammation during LAR. Thus, DE exposure exacerbates allergen-induced airway responses in guinea pigs.

Allergens↗
PubMed2001

Difference in binding by isolectin B4 to trkA and c-ret mRNA-expressing neurons in rat sensory ganglia.

The neurons labeled by isolectin B4 (IB4) in rat and mouse sensory ganglia are often regarded as non-nerve growth factor (NGF)-dependent and non-peptidergic neurons, but a considerable number of IB4-positive neurons in the dorsal root ganglion (DRG) are also shown to be immunoreactive to substance P (SP) and calcitonin gene-related peptide (CGRP), which are synthesized by NGF-dependent neurons. Therefore, we examined the relationships between the IB4-binding neurons and NGF/glial cell line-derived neurotrophic factor (GDNF)/GDNF-related proteins(GDNFs)-dependent neurons in rat DRGs by use of in situ hybridization histochemistry in serial sections. Of the DRG neurons, 42% and 22% were intensely and weakly labeled by IB4, respectively. The former neurons were small, and the latter varied in size. Of the trkA mRNA-expressing neurons, 29% and 57% were intensely and weakly labeled by IB4, respectively. On the other hand, 66% and 10% of the c-ret mRNA-expressing neurons were intensely and weakly labeled, respectively. The mRNA of somatostatin, another major neuropeptide in the sensory neurons, was exclusively expressed in the intensely IB4-labeled neurons. These findings suggest that many NGF-dependent and peptidergic sensory neurons are labeled by IB4 in rats.

Animals↗
PubMed2001

Association of the mitochondrial DNA 5178 A/C polymorphism with serum lipid levels in the Japanese population.

As one approach to exploring whether the mitochondrial DNA 5178 adenine/cytosine (mt5178 A/C) polymorphism is associated with atherosclerosis, we genotyped 461 healthy Japanese individuals and studied the relationship of mt5178 A/C genotypes to serum lipid levels. Blood specimens were obtained after at least a 12-h fasting period from the subjects. The mt5178 A/C was genotyped by the polymerase chain reaction/restriction fragment length polymorphism method. The relative frequency of mt5178 A was 41.6% (192/461) and of mt5178 C was 58.4% (269/461). After adjustments for age and body mass index, the high-density lipoprotein cholesterol concentration in males carrying mt5178 A was significantly higher than that in males carrying mt5178 C ( P=0.026). The tryglyceride (TG) concentration in females carrying mt5178 A was significantly lower than that in females carrying mt5178 C ( P=0.012). This difference in the TG level between the two genotypes was more evident in postmenopausal females than in premenopausal females. Mt5178 A seems to have an antiatherogenic effect. This is the first genetic epidemiological report on the association of mt5178 A/C polymorphism with serum lipid levels in the Japanese population.

Adenine↗
PubMed2001

Preferential degradation of osteoclasts by titanium tetrachloride.

Although titanium alloys are known to be biocompatible with bone tissue after implantation in human beings, the effect of titanium on osteoclasts remains to be studied. We examined the effect of titanium salt on the formation and survival of osteoclasts in cell culture. The addition of 10 microM titanium tetrachloride caused a decrease in the cell number of osteoclast-like cells induced in bone marrow cell cultures taken from mice. The addition of 10 microM titanium tetrachloride caused degradation of the disaggregated osteoclasts taken from neonatal rats and a decrease in bone resorption. Along with the increase in the degradation of osteoclasts, the number of apoptotic cells increased. Titanium tetrachloride dose-dependently decreased the cell number and alkaline phosphatase activity of osteoblastic cell cultures taken from rat calvaria. However, these concentrations were 30-40 times higher than those in the case of osteoclast-like cell formation. These results showed that titanium ions caused a preferential degradation of osteoclasts rather than osteoblasts, most likely by apoptosis.

Alkaline Phosphatase↗
PubMed2001

Expression of IL-1 beta and IL-8 by human gingival epithelial cells in response to Actinobacillus actinomycetemcomitans.

The interaction between epithelial cells and microorganisms is the most important step in bacterial infections. Epithelial cells in response to exposure to pathogenic bacteria produce cytokines that initiate inflammation. However, little is known about the cytokine response of gingival epithelial cells to periodontopathogenic bacteria. Actinobacillus actinomycetemcomitans is thought to play a significant role in the initiation of periodontitis because of its bacteriological characteristics. In the present study, we investigated the cytokine induction by human gingival epithelial cells (HGEC) following exposure to A. actinomycetemcomitans in comparison with human gingival fibroblasts (HGF) in culture. Northern blot analysis showed that mRNAs of interleukin 1beta (IL-1beta) and IL-8, but not IL-6, in HGEC were induced in response to A. actinomycetemcomitans. Secretion of IL-8 by HGEC was also increased following A. actinomycetemcomitans challenge, whereas production of IL-1beta could not be detected. The levels of IL-8 and its mRNA were increased depending on the concentration of A. actinomycetemcomitans. The co-culture with HGF and A. actinomycetemcomitans resulted in an increase in the levels of IL-6 and IL-8 mRNA in HGF. However, HGF exposed to A. actinomycetemcomitans, showed no expression of IL-1beta mRNA. These findings demonstrated that HGEC and HGF stimulated with A. actinomycetemcomitans have different profiles in cytokine mRNA expression. Furthermore, A. actinomycetemcomitans may play an important role in amplifying the local immune response and in initiating inflammatory reaction through release of IL-8 from gingival epithelial cells.

Aggregatibacter actinomycetemcomitans↗
PubMed2001

Magnetohydrodynamic production of relativistic jets.

A number of astronomical systems have been discovered that generate collimated flows of plasma with velocities close to the speed of light. In all cases, the central object is probably a neutron star or black hole and is either accreting material from other stars or is in the initial violent stages of formation. Supercomputer simulations of the production of relativistic jets have been based on a magnetohydrodynamic model, in which differential rotation in the system creates a magnetic coil that simultaneously expels and pinches some of the infalling material. The model may explain the basic features of observed jets, including their speed and amount of collimation, and some of the details in the behavior and statistics of different jet-producing sources.

Journal Article↗
PubMed2001

Co-infection by serologically-silent hepatitis B virus may contribute to poor interferon response in patients with chronic hepatitis C by down-regulation of type-I interferon receptor gene expression in the liver.

Intrahepatic mRNA levels of type-I interferon (IFN) receptor genes have been shown to correlate with the clinical efficacy of IFN therapy in patients with chronic hepatitis C. Recently, co-infection by serologically-silent hepatitis B virus (HBV) has been assumed to be associated with the poor IFN response in patients with chronic hepatitis C. The aim of this study was to investigate the relationship between the co-infection of serologically-silent HBV and type-I IFN receptor gene expression in the liver of patients with chronic hepatitis C. The intrahepatic mRNA levels of IFNAR2, one of the two subunits of the type-I IFN receptor, were quantified and compared with both the prevalence of HBV DNA and the hepatitis C virus (HCV) genotype in 45 patients with chronic hepatitis C, who were negative for hepatitis B surface antigen. Co-infection, as evaluated by a nested polymerase chain reaction, was present in 22 patients (48.9%), with dominance of the HCV genotype 1b (65.2%) over genotype 2a (31.8%). Co-infection was associated with lower IFNAR2 mRNA levels, higher levels of serum HCV RNA, and a poor IFN response, regardless of the HCV genotype. The findings suggest the possibility that co-infection by serologically-silent HBV is one of the factors that can lead to an unfavorable IFN response in chronic hepatitis C by down-regulation of IFN receptor gene expression in the liver.

Adult↗
PubMed2001

Disparity between the macroglobulin-producing components of 2 cases of follicular lymphoma with Waldenström's macroglobulinemia.

We report 2 patients with follicular lymphoma (FL) which was accompanied by Waldenström's macroglobulinemia (WM). One patient was a 65-year-old woman and the other a 60-year-old man. Both patients showed a high level of circulating macroglobulin (4.6 g/dL and 3.6 g/dL, respectively) and bone marrow involvement of small lymphoid cells. Moreover, in each case, the macroglobulin-producing component and the follicular component were determined to be of the same clone based on their identical light-chain restriction pattern and other factors. However, there was a difference in the histopathological characteristics of the macroglobulin-producing components of the 2 patients, especially the cytoplasmic immunoglobulin (Ig)M+ cell distribution in the biopsied lymph nodes. Test results for the female patient showed intrafollicular proliferation of those cells. The male patient's test results showed that IgM+ cells were located in the narrow extrafollicular areas of the lymph nodes. Our observations suggest that at least 2 different subtypes of FL may also be causative of a WM presentation.

Aged↗
PubMed2001

Primary adenocarcinoma of the cervical esophagus arising from heterotopic gastric mucosa.

Most esophageal malignancies are either squamous cell carcinomas or adenocarcinomas arising from Barrett's esophagus. We report a case of adenocarcinoma of the upper esophagus (cervical esophagus) that was derived from heterotopic gastric mucosa. In a 73-year-old man cervical esophagectomy was performed, followed by pharyngectomy, laryngectomy, and palliative dissection of lymph nodes on both sides of the neck, after an accurate diagnosis has been made by esophagography and endoscopy. The resected tumor was smoothly elevated (2.5 cm x 2.0 cm) and was microscopically identified as a well differentiated adenocarcinoma with invasion to the submucosa. The origin of the carcinoma was found to be a heterotopic gastric mucosa, by hematoxylin-eosin (H&E), immunohistochemical, and enzyme histochemical staining. To our knowledge, only 18 similar cases have been reported previously.

Adenocarcinoma↗
PubMed2001

Gastrointestinal stromal tumor of the duodenal ampulla: report of a case.

We report herein the case of a 77-year-old woman with a gastrointestinal stromal tumor (GIST) of the duodenal ampulla. The tumor, which was removed by pancreatoduodenectomy due to its malignant potential, showed expansive growth in the muscular coat of the duodenal ampulla. Histologically, the tumor cells were spindle-shaped or round, and exhibited fascicular or storiform growth pattern with frequent mitotic figures. The immunohistochemical and ultrastructural results suggested that the tumor may have originated from the interstitial cells of Cajal in the muscular coat of the duodenal ampulla. To our knowledge, this is the first case of malignant GIST of the duodenal ampulla to be reported in Japan.

Aged↗
PubMed2001

Analysis of the survival period in resectable stage IV gastric cancer.

BACKGROUND: Patients with stage IV gastric cancer usually have a poor prognosis, but some patients with resectable cancer survive for more than 5 years. We aimed to study the correlation of protein expression and survival in resectable stage IV gastric cancer. PATIENTS AND METHODS: Tissue samples of 42 patients with resectable stage IV gastric cancer were stained immunohistochemically for the mutant p53 protein and heat shock protein-27 (hsp27). The correlation between protein expression and clinicopathological factors was investigated. Furthermore, prognostic value of each factor was analyzed. RESULTS: Univariate analysis showed that pN factors (Japanese classification, P = .028; International Union Against Cancer classification, P = .024), blood vessel invasion (P = .043), hsp27 overexpression (P = .019), and the index of p53 and hsp27 overexpression (P = .0026) had a prognostic influence. Only Lauren classification, however, revealed the prognostic influence in multivariate analysis (P = .046). CONCLUSIONS: These results suggest that immunostaining of tumor specimens for p53 and hsp27 and clinicopathological analysis may help predict the survival of patients with resectable stage IV gastric cancer.

Adult↗
PubMed2001

Analysis of early (pT1) gastric cancer with submucosal invasion: surgical management and possibility to schedule less invasive surgery.

BACKGROUND: Early gastric cancer (EGC) is one of the popular targets of less invasive surgery. The aim of the present study is to clarify the possibility of scheduling a less invasive surgery for EGC cases with submucosal (SM) invasion. METHODS: Eighty cases of EGC with SM invasion were analyzed clinicopathologically and immunohistochemically. Correlations between factors that reflect cancer progression and data from endoscopic examination were investigated. RESULTS: Thirteen cases (16.3%) showed lymph node metastasis and the numbers of metastasis-positive lymph nodes ranged from 1 to 18. Two cases showed lymph node metastasis not only in the perigastric area, but also along the left gastric artery and the common hepatic artery. Only the tumor size showed a significant correlation with lymph node metastasis (P = .014) using the data from preoperative endoscopic examination. With respect to p53 overexpression, there was no significant correlation with pathologic factors in EGC with SM invasion. The simple protuberance types that were <2 cm in diameter had no lymph node metastasis. CONCLUSIONS: It seems difficult to predict the progression of EGC with SM invasion from the data currently obtained by preoperative endoscopic examination. It was suggested that less invasive surgery could be scheduled only for simple protuberance type cases that were <2 cm in diameter. Radical gastrectomy and D2 lymph node dissection is required, in open surgery or laparoscopic surgery, for any other type of EGC with SM invasion.

Adult↗