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Biomedical subjects

A Miyoshi

Publications and source records attributed to A Miyoshi.

At least 37 records · Page 2Linked to original sources
PubMed2001

Simultaneous expression of guinea pig UDP-glucuronosyltransferase 2B21 and 2B22 in COS-7 cells enhances UDP-glucuronosyltransferase 2B21-catalyzed morphine-6-glucuronide formation.

Although UDP-glucuronosyltransferases (UGTs) act as an important detoxification system for many endogenous and exogenous compounds, they are also involved in the metabolic activation of morphine to form morphine-6-glucuronide (M-6-G). The cDNAs encoding guinea pig liver UGT2B21 and UGT2B22, which are intimately involved in M-6-G formation, have been cloned and characterized. Although some evidence suggests that UGTs may function as oligomers, it is not known whether hetero-oligomer formation leads to differences in substrate specificity. In this work, evidence for a functional hetero-oligomer between UGT2B21 and UGT2B22 is provided by studies on the glucuronidation of morphine in transfected COS-7 cells. Cells transfected with UGT2B21 cDNA catalyzed mainly morphine-3-glucuronide formation although M-6-G was also formed to some extent. In contrast, cells transfected with UGT2B22 cDNA did not show any significant activity toward morphine. When UGT2B21 and UGT2B22 were expressed simultaneously in different ratios in COS-7 cells, extensive M-6-G formation was observed. This stimulation of M-6-G formation was not observed, however, when microsomes containing UGT2B21were mixed with those containing UGT2B22 in the presence of detergent. Furthermore, this effect was not very marked when human UGT1A1 and UGT2B21 were coexpressed in COS-7 cells. This is the first report suggesting that UGT hetero-oligomer formation leads to altered substrate specificity.

Amino Acid Sequence↗
PubMed2001

Activation of Na+/H+ exchanger is associated with hyperinsulinemia in borderline hypertensive rats.

Activation of Na+/H+ exchanger (NHE) is known to be related to elevated blood pressure in hyperinsulinemia. To test whether there is the change in NHE activity in insulin resistance, we measured NHE activity of platelets in fructose-induced hyperinsulinemia in Wistar-Kyoto rats (WKY), in borderline hypertensive rats (BHR), and in spontaneously hypertensive rats (SHR). All rats were fed a 60% fructose diet for 4 weeks to induce hyperinsulinemia and hypertriglyceridemia. Intracellular pH (pHi) was measured with a pH-sensitive fluorescent dye 2'7'-bis (2-carboxyethyl)-5-carboxyfluorescein acetoxymethyl ester. NHE activity was evaluated by the recovery of pHi following addition of sodium propionate (Vmax). Measurement of intracellular calcium ([Ca2+]i) was performed using fura2/acetoxymethylester. Systolic blood pressure in fructose diet BHR elevated significantly greater than that in control diet BHR with the increase of both [Ca2+]i and Vmax. In WKY, there was no significant increase in systolic blood pressure and [Ca2+]i except Vmax in a fructose diet. Vmax in control diet SHR was greater than in control diet WKY and BHR, and we found no additional increase in Vmax with a fructose diet in SHR. In BHR, a high salt diet increased systolic blood pressure and Vmax to a similar degree as a fructose diet or a high salt combined with a fructose diet. Plasma insulin concentration correlated positively with Vmax in WKY and BHR, but not SHR. A fructose diet induces hyperinsulinemia and elevates blood pressure in BHR. Hyperinsulinemia appears to activate NHE in a different manner in SHR, and might be associated with an elevation in blood pressure in BHR.

Animals↗
PubMed2000

Headspace solid-phase microextraction and gas chromatographic-mass spectrometric screening for volatile hydrocarbons in blood.

Optimization for headspace solid-phase microextraction (SPME) was studied with a view to performing gas chromatographic-mass spectrometric (GC-MS) screening of volatile hydrocarbons (VHCs) in blood. Twenty hydrocarbons comprising aliphatic hydrocarbons ranging from n-hexane to n-tridecane, and aromatic hydrocarbons ranging from benzene to trimethylbenzenes were used in this study. This method can be used for examining a burned body to ascertain whether the victim had been alive or not when the burning incident took place. n-Hexane, n-heptane and benzene, the main indicators of gasoline components, were found as detectable peaks through the use of cryogenic oven trapping upon SPME injection into a GC-MS instrument. The optimal screening procedure was performed as follows. The analytes in the headspace of 0.2 g of blood mixed with 0.8 ml of water plus 0.2 microg of toluene-d8 at -5 degrees C were adsorbed to a 100-microm polydimethylsiloxane (PDMS) fiber for 30 min, and measured using the full-mass-scanning GC-MS method. The lower detection limits of all the compounds were 0.01 microg per 1 g of blood. Linearities (r2) within the range 0.01 to 4 microg per 1 g of blood were only obtained for the aromatic hydrocarbons at between 0.9638 (pseudocumene) and 0.9994 (toluene), but not for aliphatic hydrocarbons at between 0.9392 (n-tridecane) and 0.9935 (n-hexane). The coefficients of variation at 0.2 microg/g were less than 8.6% (n-undecane). In conclusion, this method is feasible for the screening of volatile hydrocarbons from blood in forensic medicine.

Burns↗
PubMed2000

Effect of age and Helicobacter pylori infection on gastric acid secretion.

BACKGROUND: Whether gastric acid secretion decreases with age is still controversial. With the discovery of Helicobacter pylori, the association of this bacterium with gastric acid secretion has also been discussed. The aim of this study was to investigate the relationship between gastric acid secretion, age and H. pylori infection. METHODS: The presence of H. pylori infection, the grade of fundic atrophic gastritis (FAG), and gastric acid secretion were investigated in 280 subjects without localized lesions in the upper gastrointestinal tract. Helicobacter pylori infection was confirmed by Giemsa and immunohistochemical staining, and FAG of biopsy specimens was graded on a scale of 0-4. RESULTS: Both basal and maximal acid output decreased with age in H. pylori-positive subjects, while they did not change with age in H. pylori-negative subjects. Gastric acid secretion decreased with the progression of FAG. An age-correlated decrease in gastric acid secretion in H. pylori-positive subjects depended on an increasing prevalence of FAG with age. CONCLUSIONS: In the population studied, advancing age had no influence on gastric acid secretion in H. pylori-negative subjects. Gastric acid secretion decreases with age in H. pylori-positive subjects because of the increasing prevalence of FAG with age.

Adolescent↗
PubMed2000

[A preliminary study on the incidence of cedar pollinosis in district of Wuhan].

OBJECTIVE: To investigate the incidence of cedar pollinosis in district of Wuhan. METHOD: A survey relative to cedar pollinosis was carried out in 309 students in Hubei Medical University in 1999, including questionnaire investigation, nasal inspection and scratch test. From February to April of 2000, a clinical investigation of cedar pollinosis was adopted among 205 patients of allergic rhinitis including scratch test and nasal mucosa test. RESULT: 1. The positive rate of cedar pollen scratch test of 309 students was 7.8%. 2. 59 cases (28.8%) was hypersensitive to cedar pollen clinically in allergen test. CONCLUSION: Cedar pollinosis is one kind of important pollinosis in district of Wuhan and should be paid high attention to.

Adolescent↗
PubMed1999

Main features of DNA-based immunization vectors.

DNA-based immunization has initiated a new era of vaccine research. One of the main goals of gene vaccine development is the control of the levels of expression in vivo for efficient immunization. Modifying the vector to modulate expression or immunogenicity is of critical importance for the improvement of DNA vaccines. The most frequently used vectors for genetic immunization are plasmids. In this article, we review some of the main elements relevant to their design such as strong promoter/enhancer region, introns, genes encoding antigens of interest from the pathogen (how to choose and modify them), polyadenylation termination sequence, origin of replication for plasmid production in Escherichia coli, antibiotic resistance gene as selectable marker, convenient cloning sites, and the presence of immunostimulatory sequences (ISS) that can be added to the plasmid to enhance adjuvanticity and to activate the immune system. In this review, the specific modifications that can increase overall expression as well as the potential of DNA-based vaccination are also discussed.

Enhancer Elements, Genetic↗
PubMed1999

[Anesthetic management of a morbidly obese patient with intestinal obstruction].

We managed a morbidly obese patient [body weight 150 kg, body height 157 cm (body mass index, 61 kg.m-2)] with intestinal obstruction due to incarcerated postoperative ventral hernia. The trachea was intubated while applying cricoid pressure. The SpO2 decreased rapidly down to 30% during intubation, but increased to 100% after ventilation with oxygen. Potential problems in the anesthetic management of morbidly obese patients for emergency surgery are discussed.

Adult↗
PubMed1999

[Epidemiological survey on orchard pollinosis].

OBJECTIVE: To investigate the prevalence of Orchard Pollinosis in China. METHOD: From 1995 to 1998, an epidemiological survey on orchard pollinosis was carried on among 1,660 primary and middle school students and 2,167 university students, including questionnaire investigation, nasal inspection and scratch test. From April to June of 1998, a clinical investigation of orchard pollinosis was adopted among 30 patients of allergic rhinitis including scratch test and nasal mucosa test. RESULT: 1. The total positive rate of orchard pollen scratch test was 6.7%, and the prevalence of orchard pollinosis was 0.37%. 2. 5 cases (16.7%) were hypersensitive to orchard pollen clinically in allergen test. CONCLUSION: Orchard pollinosis is one kind of important pollinosis and should be paid high attention to.

Adolescent↗
PubMed1997

Impairment of endothelial function in salt-sensitive hypertension in humans.

In this study, we evaluated the relationship between the endothelium-dependent vasodilation and salt sensitivity in patients with essential hypertension. Fifteen untreated hypertensive male patients (age, 29 to 54 years) were sodium restricted (5 g/day) for 1 week, and placed on a high salt diet (20 g/day) the second week. At the end of each period, measurements of forearm vascular responses to drugs (acetylcholine, 3 to 24 microg/min; sodium nitroprusside, 0.15 to 1.2 microg/min; norepinephrine, 0.15 to 1.2 microg/min; and N(G)-monomethyl-L-arginine [L-NMMA], 1 to 8 micromol/min) were obtained by using strain-gauge venous plethysmography. Subjects were divided into two groups according to the blood pressure response to sodium loading: salt-sensitive hypertensive group (24-h mean increase of arterial pressure > or = 10%; n = 6) and salt-resistant group (< 10%; n = 9). The two groups showed no significant difference in clinical data or mean arterial pressure during low salt intake. The dose-dependent vasodilation induced by acetylcholine was significantly reduced (P < .05) in the salt-sensitive hypertensive patients v the salt-resistant patients regardless of sodium loading. There were no differences between the two groups in response to sodium nitroprusside, norepinephrine, or L-NMMA. These results indicate that vasodilation to acetylcholine is reduced in salt-sensitive hypertensive patients even on restricted sodium diets. This may contribute to blood pressure elevation when sodium intake is increased.

Acetylcholine↗
PubMed1997

Histopathological study on bone changes induced by recombinant granulocyte colony-stimulating factor in rats.

Histopathological bone changes were examined in growing rats intravenously administered with high doses (100 and 1000 micrograms/kg/day) of recombinant human granulocyte colony-stimulating factor (rG-CSF) for 28 days. The changes were observed in the region where physiological bone resorption actively occurs in the growth phase, that is the trabeculae of metaphyseal spongy bone and the endosteum region of diaphyseal compact bone. Histologically, the changes involved accelerated osteoclastic bone resorption and osteogenesis due to intramembranous ossification. While osteoclastic bone resorption was observed in almost all lesions, about half of which were accompanied by osteogenesis. Bone changes which appeared after administration of rG-CSF were characterized by frequent occurrence at the site of highly osteoclastic activity and by initial osteoclastic resorption followed by osteogenesis due to intramembranous ossification. These results suggest that the main action of rG-CSF on bone may be an acceleration of osteoclastic bone resorption.

Animals↗
PubMed1997

Immunohistochemical localization of cathepsin D, proliferating cell nuclear antigen and epidermal growth factor receptor in human breast carcinoma analysed by computer image analyser: correlation with histological grade and metastatic behaviour.

AIMS: The purpose of this study is to examine the relationship between immunohistochemical localization of cathepsin D (CD), proliferating cell nuclear antigen (PCNA) and epidermal growth factor receptor (EGF-R) in 65 cases of breast carcinoma in Japanese women and traditional prognostic factors such as histological grade, lymph node status, mitotic rate and clinical stage, in order to possibly identify some indicator(s) that may be specifically associated with prognosis. METHODS AND RESULTS: Serial sections of 5-micron thick were cut from the archival formalin-fixed, paraffin-embedded tissue blocks, and processed for CD, PCNA and EGF-R immunostaining. The results were analysed by computer-based image analysis system. All samples showed a positive immunoreaction for cathepsin D in both the parenchyma and stroma. However, the staining area and intensity varied from cell to cell in the parenchyma and stroma as well as among samples. Subsequently, the evaluation of immunostaining for CD was separately performed in both the parenchyma and stroma (CDpar and CDstr, respectively) and the combination of both components (CDtotal). PCNA and EGF-R showed positive immunostaining almost exclusively in the parenchymal component of the carcinoma tissue specimens. CDtotal significantly correlated with the histological grade, PCNA index (PI), mitotic rate (MR), EGF-R and lymph node metastasis. Significant correlation was also demonstrated between CDpar and the histological grade. EGF-R and lymph node metastasis, or between CDstr and MR, EGF-R and lymph node metastasis. EGF-R correlated highly with the histological grade, MR score, lymph node metastases and recurrence-free survival. CONCLUSIONS: Both the CD parameters and EGF-R are valuable indicators for predicting the biological behaviour of human breast carcinoma.

Breast Neoplasms↗
PubMed1997

[Recurrent hypertensive intracerebral hemorrhage: characteristics and risk factors].

From January 1978 to December 1995, a total of 269 patients with hypertensive intracerebral hemorrhage were treated in our institution. We reviewed 23 patients with recurrence to analyze their characteristics and risk factors. RECURRENCE RATE: The recurrence rate was 8.6%, showing it is not so rare. HEMORRHAGIC SITE: In the first hypertensive intracerebral hemorrhage, the hemorrhagic site was putaminal in 60.9%, subcortex in 13.0%, thalamic in 8.7% and cerebellar in 8.7%. In the second episode, the site was putaminal in 39.1%, thalamic in 34.8%, cerebellar in 13.0%, and subcortex in 8.7%. Therefore, during recurrence, hemorrhage occurred relatively more frequently in the thalamus than in the initial site. INTERVAL TO REBLEEDING: The Interval between the first and second hemorrhage ranged from 2 months to 15 years (average 4 years and 7 months). BLOOD PRESSURE AND RECURRENCE: In patients in whom hypertensive intracerebral hemorrhage recurred in less than 3 years from the initial hemorrhage, blood pressure was well controlled by antihypertensive drugs during the interval. This indicates that factors other than blood pressure control are concerned in the prevention of recurrence. In patients in whom hemorrhage recurred 3 years or more after the initial episode, blood pressure was poorly controlled, indicating that strict antihypertensive therapy is necessary to prevent recurrence after a long interval. RISK FACTORS FOR RECURRENCE: The following risk factors for recurrence of hypertensive intracerebral hemorrhage have been reported in the literature: diastolic blood pressure > or = 100 mmHg; unstable-hypertension (blood pressure abruptly rising from the normal range) : uncontrollable hypertension; and hypoproteinemia. Of these, we emphasize that unstable hypertension is the most important risk factor, as illustrated in our series of patients.

Adult↗
PubMed1996

Spinal giant intradural perimedullary arteriovenous fistula: clinical and neuroradiological study in one case with review of literature.

BACKGROUND: Giant intradural perimedullary arteriovenous fistula with massive spinal cord compression is rare. The therapeutic difficulties include whether endovascular embolization or direct surgical excision should be selected. We present a patient with the largest giant spinal intradural perimedullary arteriovenous fistula shown by magnetic resonance imaging so far reported, who was successfully treated by a combination of endovascular embolization and direct surgery. CASE DESCRIPTION: A 16-year-old girl presented with a giant intradural arteriovenous fistula (perimedullary Type II) at the C4-5 level, manifesting as progressive cervical myeloradiculopathy. The single-hole fistula was supplied by the anterior spinal artery and an ascending artery arising from both the costocervical and highest intercostal arteries with a rapid transit time, and drained superiorly to the foramen magnum, and inferiorly to the thoracic spinal canal, through a huge venous lake at the site of the arteriovenous connection. The patient was treated by transarterial embolization with platinum coils and silk, followed by surgical excision with excellent results at 12 months' follow-up. CONCLUSIONS: We recommend that such a huge perimedullary arteriovenous fistula with a rapid transit time, and severe cord and root compression, should be treated with embolization followed by surgical excision.

Adolescent↗
PubMed1996

Immunohistochemical localization of cathepsins D and E in human gastric cancer: a possible correlation with local invasive and metastatic activities of carcinoma cells.

The immunohistochemical localization of cathepsins D and E in 44 cases of human gastric carcinoma, using antibodies specific for each enzyme, were investigated. Cathepsin D- and E- positive carcinoma cells were present in all samples. However, the staining intensity varied from cell to cell in the same carcinoma tissue as well as among samples. The most intense immunostaining of both cathepsins was often found in the cells, which were present at the advancing margin of the carcinoma tissues. The incidence of this peculiar localization of intensely stained carcinoma cells significantly correlated with the progression of the carcinoma tissue (D, P < .05; E, P < .01) and with occurrence of the lymph node metastasis (D and E, P < .05). There was no statistical significance between this localization and the histological type (differentiation) of the carcinoma tissues. Cathepsin-positive inflammatory cells infiltrated in and around the carcinoma tissue, and intensely stained inflammatory cells were often located in the stroma at the border of the carcinoma tissue. However, no statistical correlation was noted between the localization of cathepsin-positive inflammatory cells at the border and the stage of progression or the incidence of metastasis. These results indicated that cathepsins D and E in the carcinoma cells located at the advancing margin play an important role in the invasion and subsequent metastasis of human gastric carcinoma. Meanwhile, cathepsin-positive inflammatory cells seem to be less responsible for the biological behavior of carcinoma cells than those in the carcinoma cells themselves.

Adenocarcinoma↗
PubMed1995

[Successful treatment with combined chemotherapy (carboplatin, etoposide, adriamycin, bleomycin) and radiotherapy for recurrent intracranial malignant germ cell tumor: case report].

We report a case of a patient with recurrent malignant germ cell tumor who was successfully treated with carboplatin combination followed by radiation therapy. A 13 year-old female presented with diabetes insipidus six years ago. From the homogeneous tumor intensity on CT scan and negative titer of AFP and HCG, we made a diagnosis of suprasellar germinoma, and treated her with radiation therapy (40Gy), which resulted in almost complete disappearance of the tumor. The tumor recurred six years later in the primary region and in the cervical spinal cord with elevated AFP titer (160ng/ml) and HCG titer (404mlU/ml). She was treated with multi-agents chemotherapy consisting of carboplatin (450mg/m2, day 1), etoposide (150mg/m2, days 1-3), adriamycin (30mg/m2, day 1), and bleomycin (20mg/m2, days 1 and 8), followed by radiation therapy to the whole brain (20Gy), the whole spine (30Gy) and the cervical spine (20Gy). The tumors completely disappeared. We discuss treatment failures of clinically diagnosed germinoma without histological verification, and effective aggressive chemotherapy for recurrent malignant germ cell tumors.

Adolescent↗