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Biomedical subjects

Y Yamashiro

Publications and source records attributed to Y Yamashiro.

At least 73 records · Page 4Linked to original sources
PubMed1999

The precise breakpoints of a Filipino-type alpha-thalassemia-1 deletion found in two Japanese.

The breakpoints of alpha-thalassemia-1 were thoroughly characterized in two Japanese families. The crossover occurred between Alu repeats at about 1.28 kb 5' to the zeta2 gene and about 1.2 kb 3' to the theta1 gene, resulting in the deletion of a 30.656 kb-long segment. These breakpoints are consistent with those surmised for the "Filipino type (--FIL)" deletion by Southern blot analysis. Also the length of the 3' hypervariable region of the alpha-globin gene conformed to that of --FIL. The two Japanese families are related to the Taiwanese and Filipino families.

Adolescent↗
PubMed1999

[The detection of apoptosis cells by TUNEL stain in peripheral blood smears].

We have determined the fixative conditions for TUNEL stain in peripheral blood smears. Murine IL-3 dependent B cell line (BAF-3) was used as positive control. The intensity of fixing solutions effected on the positivity/negativity for TUNEL stain. Alive cells showed positivity for TUNEL stain (false positive), when 70% methyl alcohol, acetone or carnoy fluid was used. In contrast to the strong fixation by high concentrated glutaraldehyde and the phosphate buffer, denatured cells showed to be negative (false negative). The fixation by 0.4% glutaraldehyde and 70% methyl alcohol for 15 min at room temperature, followed by the treatment by 20 micrograms/ml proteinase K for 15 min at 37 degrees C was most suitable for TUNEL stain to detect the apoptotic cells in peripheral blood smears. The frequency of TUNEL positive cells increased significantly in peripheral blood cells treated by apoptosis induced reagents, or infected by CMV. This is a new approach for the techniques to detect the apoptotic cells in peripheral blood smears.

Apoptosis↗
PubMed1998

Molecular cloning and characterization of the gene encoding human NeuroD.

NeuroD is a basic helix-loop-helix transcription factor that binds to an E-box sequence, CANNTG, in the target gene promoter region. The gene encoding NeuroD is expressed specifically in brain, intestine, and pancreatic cells and plays a pivotal role in tissue-specific differentiation. To investigate the regulation of human NeuroD gene expression, we isolated and sequenced a genomic DNA containing two exons and flanking regions of the NeuroD gene. The sizes of exons 1 and 2 were 168 and 2404 bp, respectively. CAT reporter analysis showed that the elements responsible for basal promoter activity lay in the proximal 408-bp region. Cotransfection of the CAT reporter plasmids with a NeuroD expression plasmid resulted in 5-fold enhancement of the CAT activity, indicating an autoregulatory mechanism is involved in human NeuroD gene expression.

Amino Acid Sequence↗
PubMed1998

Dystrophin acts as a transplantation rejection antigen in dystrophin-deficient mice: implication for gene therapy.

Duchenne muscular dystrophy is a lethal and common X-linked recessive disease caused by a defect in dystrophin. Normal myoblast transplantation and dystrophin gene transfer have been expected to correct the deficiency in the muscles, but their clinical application has been hampered by the limited preservation of dystrophin-positive myofibers. In this study we investigated the mechanism for immunologic rejection of normal C57BL/10 (B10) myoblasts transplanted into dystrophin-deficient mdx mice, an animal model of Duchenne muscular dystrophy. We found that mdx mice develop CTL specific for dystrophin itself, which were CD8 dominant and restricted by H-2Kb. We identified several antigenic peptides derived from dystrophin that bind to H-2Kb and are recognized by the mdx anti-B10 CTL. Immunologic tolerance against dystrophin was successfully induced by i.v. injection of these peptides before B10 myoblast transplantation, which resulted in sustained preservation of dystrophin-expressing myofibers in mdx mice. These results demonstrate that dystrophin is antigenic in dystrophin-deficient mice and that immunologic regimen would be necessary to achieve the persistent expression of introduced dystrophin in the muscles of dystrophin-deficient individuals.

Amino Acid Sequence↗
PubMed1998

Combined angioplasty and valvuloplasty for coexisting coarctation of the aorta and aortic stenosis in an infant.

The patient was a 1-month-old male infant. Echocardiography showed left ventricular hypertrophy with coarctation of the aorta (CoA) and aortic valve stenosis (AVS). Left ventricular systolic function was poor. At catheterization, the gradient of AVS was 25 mmHg and the annulus size of the aortic valve was 7 mm. There was a CoA measuring 2.1 mm in diameter. Balloon valvuloplasty of the CoA was then performed using the same balloon; the pressure gradient decreased to 0 mmHg, and CoA diameter decreased from 2.1 to 5.5 mm.

Angioplasty, Balloon↗
PubMed1998

Increased serum trypsin and elastase-1 levels in patients undergoing L-asparaginase therapy.

UNLABELLED: Although there is abundant literature on the association of L-asparaginase and acute pancreatitis in patients undergoing chemotherapy, few studies have investigated the usefulness of pancreatic enzyme measurement in the early diagnosis of L-asparaginase-induced acute pancreatitis. We measured levels of serum pancreatic enzymes before, during, and after L-asparaginase therapy in nine children with acute lymphocytic leukaemia or non-Hodgkin lymphoma. Serum levels of amylase, pancreatic isoamylase, and lipase did not change between the 1st and 30th day of L-asparaginase administration. However, the serum trypsin and elastase- levels, 10 and 20 days after beginning L-asparaginase therapy, were significantly higher than those prior to therapy. CONCLUSION: L-asparaginase may induce subclinical pancreatitis and the estimation of serum trypsin and elastase-1 may be useful in the early diagnosis of L-asparaginase-induced acute pancreatitis.

Acute Disease↗
PubMed1998

Correlation of prostaglandin E2 production and gastric acid secretion in infants with hypertrophic pyloric stenosis.

PURPOSE: The aim of this study was to evaluate the relationship between gastric acid secretion and prostaglandin E2 (PGE2) generation in gastric mucosa and the role of PGE2 in the pathogenesis of hypertrophic pyloric stenosis (HPS). METHODS: The authors measured the levels of PGE2 and gastric acidity in the gastric juice of HPS patients before and after a Ramstedt operation. RESULTS: The PGE2 concentration in the gastric juice of nine HPS patients before the Ramstedt operation was significantly higher than that of eight controls, and the concentration significantly decreased after the operation. A significant inverse correlation between the PGE2 concentration and the pH level in the gastric juice was shown in HPS patients before and after the operation. CONCLUSION: These results suggest that the enhanced generation of PGE2 in gastric mucosa in cases of HPS is a secondary phenomenon caused by hyperacidity and is not responsible for the pathogenesis of HPS.

Dinoprostone↗
PubMed1998

Inhaled corticosteroid reduced lamina reticularis of the basement membrane by modulation of insulin-like growth factor (IGF)-I expression in bronchial asthma.

BACKGROUND: Pathological studies of bronchial biopsy specimens have confirmed the apparent thickening of lamina reticularis of the epithelial basement membrane. Corticosteroids have proven to be most effective in modifying airway inflammation. However, there is not much data on the effects of corticosteroid-treatment on the basement membrane. OBJECTIVE: To investigate the effects of inhaled beclomethasone dipropionate (BDP) on the thickness of basement membrane and cellular infiltration into the bronchial mucosa, and the expression of growth factors in patients with asthma. METHODS: We studied bronchial biopsies from 24 asthmatic patients before and after treatment with inhaled BDP, 400 microg twice a day or placebo, for 6 months in a double-blind manner. Each subject recorded daily asthma symptoms and peak expiratory flow (PEF). Lung function and bronchial responsiveness to methacholine were measured before and after treatment. The thickness of the basement membrane was determined by electron microscopy. Inflammatory cells and the expression of growth factors were examined by immunohistochemistry in endobronchial biopsy specimens. RESULTS: After 6 months of treatment, we observed a significant improvement of asthma symptoms (P<0.01), PEF (P<0.01), diurnal variation of PEF (P<0.05), and airway responsiveness (P< 0.05) in the BDP group compared with the placebo group. This was accompanied by a significant decrease in the thickness of the lamina reticularis (P < 0.001), and in the number of activated eosinophils (P<0.01), T-lymphocytes (P<0.01), and fibroblasts (P < 0.05) in BDP-treated patients. There was also a reduction in the expression of insulin-like growth factor (IGF)-I (P < 0.01). Significant correlation was found between the IGF-I expression and collagen thickening (rs = 0.34, P<0.01), and the number of fibroblasts (rs = 0.45, P < 0.01). CONCLUSION: These results suggest that corticosteroid treatment in asthma can reduce the lamina reticular thickness by modulation of IGF-I expression with consequent inhibition of the airway infiltration by inflammatory cells, and therefore may help to prevent remodelling of the airways.

Administration, Inhalation↗
PubMed1998

Nephropathy and hypertension as manifestations in a 13-y-old girl with primary antiphospholipid syndrome.

Severe renal hypertension due to both unilateral renal arterial occlusion and renal thrombotic microangiopathy developed in a 13-y-old girl as a manifestation of primary antiphospholipid antibody syndrome. The combination of the intravenous high-dose urokinase therapy and oral anticoagulation therapy, comprising aspirin, warfarin and dipyridamole, was significantly effective in improving her renal function and preventing thrombotic events during an 18-month follow-up period.

Adolescent↗
PubMed1998

Usefulness of arousal for the diagnosis of sleep breathing disorder.

We hypothesize that breathing disorder related arousal index (B-ArI) can differentiate sleep breathing disorder from simple snorer when apnea hypopnea index (AHI) is low. We studied 54 patients using polysomnography. Breathing disorder related arousal (B-Ar) was defined as arousal accompanied by apnea, hypopnea, desaturation or snort. Mean AHI was 44.2+/-34.0/h, and B-ArI correlated significantly with AHI, desaturation index, percentage total sleep time with SpO2 below 90%. Breathing disorder related arousal index was greater than AHI when AHI was below 20. In 11/54 patients, AHI was below 10, and B-ArI more than 10. Nasal continuous positive airway pressure was applied to six patients and showed reduced B-ArI. Breathing disorder related arousal index may be one of the useful indices for the diagnosis of sleep breathing disorder when AHI is less than 10.

Adult↗
PubMed1998

Clinical electroencephalographic study of nine pediatric patients with convulsion induced by the TV animation, Pocket Monster.

BACKGROUND: To determine the usefulness of a few types of photic stimulation in patients with photo-convulsive response. METHODS: A clinical electroencephalographic study was conducted in nine children who developed convulsions and other symptoms while they watched the TV animation and were subsequently treated at the hospital. Photic stimulation was applied with their eyes open or closed. Another photic stimulation was applied with the video tape of the animation. RESULTS: A photoparoxysmal response (PPR) was never seen in the electroencephalographs (EEG) in any of these patients when photic stimulation was applied with their eyes closed, while PPR was seen in three of seven patients when photic stimulation was applied with their eyes open. Two patients (siblings) showed no specific abnormality when photic stimulation was applied with their eyes either open or closed. However, myoclonus and PPR appeared when the EEG was conducted while they watched the video tape of the animation under supervised conditions. CONCLUSIONS: In a society where people are exposed to abundant TV games, TV animation or videos, self-restraint or regulations of frequent use of flickering scenes is thought to be necessary. However, it is also thought to be necessary to conduct EEG by applying photic stimulation, not only with the eyes closed, but also with the eyes opened or by applying flickering red light stimulation, which is emitted from a strong light source, or a combination of two colors, such as red and blue or red and green, in patients with suspected photosensitivity.

Adolescent↗
PubMed1998

Experimental study of coil embolization using a new atelocollagen spring coil.

Spring steel coils have been used to occlude abnormal vessels in patients with a congenital heart malformation. However, long-term adverse effects of steel spring coils remain uncertain, although some long-term results appear to be good. The purpose of this study was to evaluate the angiographic and histologic results of coil embolization experimentally using a biodegradable atelocollagen coil that we have recently developed. The spring coil was made from a 30% atelocollagen solution mixed with a contrast medium. The delivery system consisted of a 5-F end-hole catheter and a 3-F modified biotome catheter as a catch and release system. Coil embolization was percutaneously attempted in 12 dogs, and only one coil was placed in each dog so that a variety of endothelial coverage could be evaluated both in complete and incomplete occlusion. At 1 wk to 5 mo after the procedure, the occluded vessels were resected and examined histologically. Postprocedural angiography showed complete occlusion in 6 of the 12 vessels and partial occlusion in 6. Follow-up angiography showed complete occlusion in 8 and incomplete occlusion in 4. Histologic examination revealed that diffuse thrombosis around the coil loops and the exchange between blood and contrast medium were detectable as early as 7 d after embolization. Atelocollagen was gradually replaced with fibrous tissue and became markedly degraded by 5 mo. Atelocollagen spring coils can be used to occlude abnormal vessel effectively and safely. The histologic reactions and the fate of the coil seem to be within tolerable limits. This experimental study supports the feasibility of a clinical trial of this coil embolization in patients with an aorticopulmonary collateral artery.

Animals↗