Search PubMed⌕ Search

Biomedical subjects

E Yamada

Publications and source records attributed to E Yamada.

At least 55 records · Page 3Linked to original sources
PubMed1999

Prevalence of asthma and related symptoms in school-age children in São Paulo, Brazil--International Study of Asthma and Allergies in Children (ISAAC).

We studied the prevalence of asthma and related symptoms using a standard written questionnaire designed for the International Study of Asthma and Allergies in Children (ISAAC). The written questionnaire (questions 1-8 related to asthma) was applied to 3005 children aged 6-7 years and to 3008 children aged 13-14 years. The parents of the 6-7-year-old children answered the questionnaire, whereas the 13-14-year-old children answered the questionnaire themselves. Response rates were 72% in the 6-7-year-old group and 94% in the 13-14-year-old group. There was a slight predominance of females in the population studied (male:female ratio 0.94). In the group of the 6-7-year-old children, the prevalence of diagnosed asthma was 7.3% for boys and 4.9% for girls, and in the group of the 13-14-year-old children, the prevalence was 9.8% and 10.2% for boys and girls, respectively. Asthma severity was similar for both age groups, and wheezing following exercise was more frequent among the adolescents. In keeping with studies in other parts of the world, comparison between reported symptoms and diagnosed asthma revealed significantly lower frequency of diagnosed asthma, suggesting that in the population we have studied, asthma is underdiagnosed. Using a global cut-off score to define asthma, we found a significantly higher prevalence of asthma among 6-7-year-old boys, as compared to girls (23.8% vs. 20.4%), and no significant differences among adolescent boys and girls (22.5% and 21.9%, respectively).

Adolescent↗
PubMed1999

Tryptophan-niacin metabolism in liver cirrhosis rat caused by carbon tetrachloride.

We investigated the change of tryptophan-niacin metabolism induced by carbon tetrachloride (CCl4) in rats with liver cirrhosis. The rats were injected with CCl4 (0.5 or 1 mL of 50% olive oil solution/kg body weight) twice a week for 1 or 2 mo and given phenobarbital water simultaneously. The urinary excretions of nicotinamide (Nam) and its metabolites were assayed. As the result, the urinary excretion of Nam, N1-methyl-4-pyridone-3-carboxamide (4-Py), Nam + N1-methylnicotinamide (MNA) + N1-methyl-2-pyridone-5-carboxamide (2-Py) + 4-Py was lower in the CCl4-treated groups than in the non-treated group (control) regardless of the experimental period (1 mo and 2 mo) or dosing amount of CCl4 (0.5 and 1 mL). Moreover, we investigated which pathway of tryptophan-niacin metabolism was affected in CCl4-treated rat. As the result, the possibility that the MNA-->4-Py reaction is inhibited by CCl4 treatment was suggested in this experiment.

Alanine Transaminase↗
PubMed1998

Myocardial Doppler velocity imaging--a quantitative technique for interpretation of dobutamine echocardiography.

Myocardial Doppler velocity (MDV) imaging was evaluated as a quantitative method for interpretation of dobutamine echocardiography by comparison with regional wall motion abnormalities in 70 patients with known or suspected coronary artery disease. Ischemic segments had the lowest increment of systolic MDV from rest to peak dose, and using a peak MDV of <12 cm/s to define an abnormal response, the sensitivity and specificity of MDV for ischemia was 86% and 96% for basal segments, and 81% and 89% for mid segments.

Aged↗
PubMed1998

X-ray microprobe system for XRF analysis and spectroscopy at SPring-8 BL39XU.

An X-ray microprobe system for X-ray fluorescence (XRF) analysis and spectroscopy has been developed at SPring-8 BL39XU; it comprises an X-ray focusing or collimation system, energy-dispersive (ED) and wavelength-dispersive (WD) XRF spectrometers, and a sample-scanning system. The conventional ED spectrometer will be utilized for qualitative and quantitative trace-element analysis, and the WD spectrometer will be used both for trace-element analysis and XRF spectroscopy. A combination of monochromated undulator radiation and the WD spectrometer will enable resonant XRF spectroscopy using brilliant hard X-ray undulator radiation.

Journal Article↗
PubMed1998

Platelet-derived growth factor B-chain expression in the rat retina and optic nerve: distribution and changes after transection of the optic nerve.

To test the possible involvement of platelet-derived growth factor B-chain (PDGF-B) in anterograde and retrograde degenerations of the CNS neurons, we studied the changes of PDGF-B localization and its mRNA expression in the rat retina and optic nerve (ON) after unilateral ON transection, using immunohistochemistry and in situ hybridization. In the control retinas immunoreactivity for PDGF-B and its mRNA expression were localized in the retinal ganglion cells (RGCs) and the nerve fiber layer. After ON transection PDGF-B immunoreactivity in the nerve fiber layer started to decrease on post-injury day 3 or 4. Atrophic changes in the RGCs started on day 5 just after the decrease of PDGF expression, and thereafter the RGC number decreased. In the longitudinal section of the ON rostral to the transected site, swollen axons showed intense PDGF-B immunoreactivity and macrophages, and some glial cells revealed a significant increase in both immunoreactivity and hybridization signals. Based on these findings, we hypothesized that the decrease in PDGF-B in RGCs after axotomy causes the loss of RGCs, and that increased PDGF-B expression in the ON plays a role in the cascade of tissue reactions following ON transection.

Animals↗
PubMed1998

Application of the polymerase chain reaction for the diagnosis of malignant lymphoma of the nasal and oral cavities.

Difficulties are often encountered in the diagnosis of malignant lymphoma of the oral and nasal cavities by histology and immunohistochemistry because these malignancies may be complicated by inflammation and necrosis. In the present study, immunoglobulin heavy chain (IgH) and T-cell receptor (TCR) gene rearrangements were examined by the polymerase chain reaction (PCR) in formalin-fixed and paraffin-embedded specimens obtained from 18 patients; the advantages of this method were evaluated. Twelve of these patients were diagnosed as having malignant lymphoma and six had tumors highly suggestive of malignant lymphoma. Fourteen (78%) of the 18 cases were diagnosed as malignant lymphoma histologically and immunohistochemically. Sixteen (89%) of the 18 cases were shown to be monoclonal by PCR. The four cases that could not be histologically or immunohistochemically diagnosed as malignant lymphoma showed monoclonal gene rearrangement by PCR. As a result, six patients suspected of having a malignant lymphoma were diagnosed as having one. The diagnosis of malignant lymphoma by PCR alone still has various problems. However, when the results of PCR are evaluated together with histopathological and immunohistochemical results, PCR makes a useful contribution to the diagnosis of malignant lymphomas of the nasal and oral cavities.

DNA, Neoplasm↗
PubMed1998

Effect of 26,26,26,27,27,27-Hexafluoro-1,25-dihydroxyvitamin D3 on the expression of vitamin-D-responsive genes in vitamin-D-deficient mice.

26,26,26,27,27,27-Hexafluoro-1,25-dihydroxyvitamin D3 (ST-630) is a newly developed agent to maintain the levels of calcium and phosphorus in blood. Herein, we investigated the effect of this compound on the expression of vitamin-D-responsive genes in vitamin-D-deficient mice. ST-630 was more effective than 1, 25-dihydroxyvitamin D3 [1,25(OH)2D3] with respect to the induction of Cyp24 and calbindin-D9k mRNAs in the kidney and in the small intestine. Moreover, the increase in mRNA levels of vitamin-D-responsive genes induced by ST-630 lasted longer than that induced by 1,25(OH)2D3. These results indicate that ST-630 was more effective in inducing Cyp24 and calbindin-D9k gene expression than 1, 25(OH)2D3 when both compounds were injected into vitamin-D-deficient mice.

Animals↗
PubMed1998

Overexpression of the ERK/MAP kinases in oral squamous cell carcinoma.

Mitogen-activated protein kinase (MAPK) is a serine-threonine kinase that is activated by various extracellular stimuli. Extracellular signal-regulated kinases (ERK1 and ERK2), an MAPK subfamily, are activated by many oncogenes, such as ras and raf, and they induce cell proliferation. myc is also an oncogene and one of the targets of ERKs. Mutations of ras and overexpression of myc were found in various human cancers, and ERKs were also reported to play a role in carcinogenesis. In this study, we examined 39 biopsy specimens of oral squamous cell carcinoma (OSCC) and 5 of normal gingival mucosa for the expression of ERK protein and the proliferation marker, MIB-1 (Ki-67 antibody). Thirteen OSCC specimens and five normal gingival biopsies were also examined for the expression of ERKs mRNA by in situ hybridization. Double staining for ERKs and MIB-1 was also performed. Histologically, 18 patients (46%) were diagnosed with well-differentiated SCC, 17 (44%) with moderately differentiated SCC, and 4 (10%) with poorly differentiated SCC. The histologic grade correlated with the MIB-1 index. The localization of ERK1 was similar to that of ERK2. Positive signals for ERK proteins were localized in superficial keratinocytes in normal gingival mucosa, whereas these mRNAs were weakly positive in the basal and spinous layer. Basal and suprabasal cells were positive for MIB-1. In well-differentiated and moderately differentiated OSCC, positive signals for ERK mRNA and proteins were found at higher levels than in normal gingival mucosa in keratotic cells around cancer pearls. Some cells showed positive signals for ERKs and MIB-1. Furthermore, most cancer cells in poorly differentiated SCC were positive for both ERK and MIB-1. The histologic grade was statistically related to the percentage of cells positive for both ERK and MIB-1. This suggested that ERKs might be related to proliferation in OSCC.

Antigens, Nuclear↗
PubMed1997

Increased expression of extracellular signal regulated kinase 1 after axotomy in the dorsal motor nucleus of the vagus nerve and the hypoglossal nucleus.

The extracellular signal regulated kinases (Erks) cascade is a major signalling system by which cells transduce extracellular signals into intracellular responses. To obtain information about the role of Erks in retrograde neuronal reaction, we investigated the changes of Erk 1 and Erk 2 with in situ hybridization and immunohistochemical study in the dorsal motor nucleus of vagus nerve, which shows degenerative changes, and the hypoglossal nucleus, which shows regenerative changes, of adult rats after axotomy. The expression of mRNA and protein of Erk 1 increased between 7 and 28 days after axotomy both in the vagal and hypoglossal nuclei, however, there was no remarkable change in those of Erk 2. The increased expression of Erk 1 is common to both regenerative hypoglossal and degenerative vagal neurons. These findings indicate that Erk 1 is closely related with the retrograde neuronal reaction but whether neurons are destined to survive or die depends on some other factors.

Animals↗
PubMed1997

Molecular cloning and characterization of a novel putative STE20-like kinase in guinea pigs.

Protein kinases play a key role in cell growth and differentiation. We have isolated the cDNA of a novel protein serine/threonine kinase (referred to as STE20-like kinase (SLK) from a guinea pig liver cDNA library with a probe generated by a cloning approach based on the polymerase chain reaction. The encoded polypeptide (1231 amino acids, M(r) 141,079) contains all conserved subdomains characteristic of the protein serine threonine kinase family. A hemagglutinin-tagged SLK expressed artificially in COS7 cells was hyperphosphorylated by anisomycin. By Northern blot analysis, SLK mRNA was detected in all organs examined: brain, lung heart, liver, kidney, spleen, testis, and eosinophils. Sequence comparisons of its catalytic domain related SLK to p21-activated kinase family of protein serine/threonine kinases. Its noncatalytic domain comprises several intriguing structural features, including the acidic region and the nuclear targeting sequence. This noncatalytic domain exhibited no extended similarity with other proteins. Thus, SLK is a protein serine/threonine kinase which contains an unknown regulatory domain(s).

Amino Acid Sequence↗
PubMed1997

Usefulness of transesophageal echocardiography in detecting changes in flow dynamics responsible for malperfusion phenomena observed during surgery of aortic dissection.

Intraoperative transesophageal echocardiography (TEE) was performed in order to study the flow dynamics in the descending aorta during surgery of aortic dissection Stanford A. TEE was seen to be a sensitive and accurate method to promptly detect severe decrease in retrograde pump flow and to clarify some of the mechanisms that can result in malperfusion during cardiopulmonary bypass.

Adult↗
PubMed1997

Simultaneous expression of ferredoxin, ferredoxin reductase and P450 in COS7 cells.

cDNA fragments encoding mouse ferredoxin and ferredoxin reductase were simultaneously introduced into COS7 cells by using an expression vector, pUC-SR alpha plasmid. When using the mitochondrial fraction prepared from the transfected cells, cytochrome-c reductase activity was detected. This activity was highest when 7.5 micrograms of the ferredoxin expression plasmid (pSR alpha F) and 2.5 micrograms of the ferredoxin reductase expression plasmid (pSR alpha FR) were transfected into COS7 cells. In this system, NADPH could be replaced by NADH as a cofactor for the reduction of cytochrome-c although the cytochrome-c reductase was more dependent on NADPH than NADH at a low concentration. When CYP24 expression plasmid was transfected into COS7 cells along with both pSR alpha F and pSR alpha FR, the transfected cells revealed a 3-fold higher 25-hydroxyvitamin D3-24-hydroxylase activity than COS7 cells transfected with CYP24 expression plasmid.

Animals↗
PubMed1997

Altered expression of src tyrosine kinase after axotomy.

Although most peripheral neurons show regenerative changes after axotomy, neurons of some nuclei show degenerative changes. To study the mechanisms responsible for such differences in neuronal reactions after axotomy, we investigated the changes of pp60c-src and phosphotyrosine (pTyr) in the dorsal motor nucleus of the vagus nerve and the hypoglossal nucleus after transection of each nerve in adult rats using immunohistochemistry. Polyclonal antibody against pp60v-src stained the cytoplasm of neurons homogeneously in both the severed and non-severed sides of the vagal and hypoglossal nuclei from days 1 to 56 after axotomy. On the other hand, the monoclonal antibody against pp60v-src (mAb327, which recognizes src homology 3 region in pp60src as an epitope) showed different immunoreactivities. No pp60c-src immunoreactivity was observed in neurons in either the vagal and hypoglossal nuclei of the non-severed side between days 1 and 56, whereas in the severed side of the hypoglossal nucleus intense pp60c-src immunoreactivity was observed along the plasma membrane of neurons from days 5 to 28 after axotomy. In contrast, in the severed side of the vagal nucleus pp60c-src immunoreactivity appeared along the plasma membrane of neurons on day 5 and remained until day 7. Conformational changes accompanying the activation of pp60c-src are suggested to cause differences in immunoreactivities of these antibodies. The expression (or activation) of pp60c-src in the neurons was stronger and longer lasting in the hypoglossal nucleus, which regenerates successfully after axotomy, than in the dorsal motor nucleus of the vagus nerve, which undergoes necrobiotic reaction. These results indicate that pp60c-src plays an important role in regeneration after axotomy.

Animals↗
PubMed1997

Three-dimensional images of the mouse submandibular gland: an HRSEM study.

The three-dimensional characteristics of the intracellular components of acinar cells were revealed using the osmium-DMSO-osmium method. The specimens were macerated in diluted osmium after being fractured in DMSO solution. The stacks of the Golgi apparatus, the rough endoplasmic reticulum and mitochondria are clearly seen. The lamellae of the rough endoplasmic reticulum, located around the nuclei and the Golgi apparatus, are shown in three-dimensional images. At high magnification, the mitochondria clearly reveal their cristae mitochondriales.

Animals↗
PubMed1997

Structural changes of immunoglobulin G oligosaccharides with age in healthy human serum.

Age-related changes of IgG N-linked oligosaccharides isolated from normal human serum are reported for 403 individuals (male 227 and female 176), varying in age from 0 to 85 years. The IgG N-linked oligosaccharides were released from the protein by digestion with a glycoamidase and reductively aminated with the fluorescent reagent, 2-aminopyridine. The mixture of pyridylaminated oligosaccharides was separated at high resolution by HPLC using a reverse-phase column. From the results of neutral oligosaccharide analysis, agalactosyl glycoform and bisecting GlcNAc-containing glycoform were shown to increase with increasing age. Spearman's correlation coefficients were 0.503 and 0.473, respectively. Thus, in healthy people, an increase of both types of glycoforms correlates weakly with age. In addition, differences were demonstrated between male and female groups in their twenties. The quantity of agalactosyl glycoform was found to be lower in females than in males. No significant differences, however, were observed in the quantity of bisecting GlcNAc-containing glycoforms between males and females.

Adolescent↗
PubMed1997

Differential display analysis of murine collagen-induced arthritis: cloning of the cDNA-encoding murine ATPase inhibitor.

We used the differential display technique in order to detect a new gene involved in murine type II collagen-induced arthritis (CIA). In this study, we have identified a novel gene, IF1, whose expression level is increased during the natural course of CIA. Northern blot analyses suggest that IF1 is involved in the natural course of CIA but is not involved as a trigger of CIA. IF1 is considered to be the murine ATPase inhibitor gene for several reasons. First, IF1 shows an extremely high homology to the rat ATPase inhibitor; the highly conserved region between rat and bovine amino acid residues 22-45, which is the minimum sequence showing ATPase inhibitory activities, is also highly conserved in IF1. Second, IF1 possesses a histidine-rich region in the same area, which is thought to be important for regulation of mammalian inhibitors. Third, the tissue distribution of IF1 is very suggestive. The expression of IF1 was very strong in energetic organs such as the heart, brain and kidney, and the development of arthritis requires great amounts of ATP. As arthritis develops rapidly, the cellular ATP pool may be decreased. Before the ATP pool is exhausted, the ATPase inhibitor may serve as a brake for ATP hydrolysis. If the supply of free energy can be reduced, the inflammation of arthritis may in turn be restored. Our hypothesis is that the ATPase inhibitor is involved in regulating the inflammatory responses.

Amino Acid Sequence↗