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Biomedical subjects

H Ebihara

Publications and source records attributed to H Ebihara.

At least 19 recordsLinked to original sources
PubMed1998

Combination latissimus dorsi and rectus abdominis musculocutaneous flap for primary repair of a large upper limb defect.

The usefulness of flap transfer in reconstructive surgery is well established, and various types of flaps have been reported. However, concomitant use of skin grafts or repair by plural flaps must be utilized for large defects. We have obtained satisfactory results in the primary repair of a large defect covering the entire length of the upper limb by using a combination flap consisting of latissimus dorsi and rectus abdominis musculocutaneous flaps. This surgical procedure is relatively easy, safe, and reliable. Moreover, it is possible to harvest a combination flap possessing a wide arc of rotation with either the latissimus dorsi muscle or the rectus abdominis muscle as a pedicle. This reconstructive method should be considered for large defects.

Adult↗
PubMed1998

Four geographically distinct genotypes of JC virus are prevalent in China and Mongolia: implications for the racial composition of modern China.

JC polyomavirus (JCV) is ubiquitous in humans, persisting in renal tissue and excreting progeny in urine. It has been shown that the genotyping of urinary JCV offers a novel means of tracing human migrations. This approach was used to elucidate the racial composition of modern China. JCV isolates in the Old World were previously classified into nine distinct genotypes. One of them (B1) has a wide domain, encompassing part of Europe and the entirety of Asia. By constructing a neighbour-joining phylogenetic tree, all B1 isolates detected so far were classified into four distinct groups (B1-a to -d), each occupying unique domains in the world. According to this revised classification system of JCV DNAs, four genotypes (CY, SC, B1-a and -b) were found to be prevalent in China and Mongolia (Mongolia was studied instead of Inner Mongolia, which is part of China). There was a remarkable variation in the incidence of genotypes among the sites of sample collection. CY was more frequently detected in Northern China, SC was predominant in Southern China and B1-b was detected only in Mongolia. B1-a was spread throughout China. These data were statistically analysed and the observed regional differences in the incidence of genotypes were found to be significant. It is likely that these differences in JCV distribution in China reflect the intermingling of different population groups that constitute modern China.

Base Sequence↗
PubMed1998

Characterization of Bacillus sp. endo-beta-N-acetylglucosaminidase and its application to deglycosylation of hen ovomucoid.

A bacterial strain isolated from soil and identified as a Bacillus species produced two endo-beta-N-acetylglucosaminidases in the culture broth when it was cultivated on medium containing only hen ovomucoid. Almost no production of the enzymes occurred when the bacterium was grown on glucose medium. The two endo-beta-N-acetylglucosaminidases, named Endo-BI and Endo-BII, were separated and purified to homogeneity by preparative gel electrophoresis after partial purification by column chromatography on DEAE-resins. Endo-BI hydrolysed oligosaccharides of both hen ovalbumin and ovomucoid. In contrast, Endo-BII could act only on oligosaccharides of hen ovalbumin and showed almost no activity towards those of hen ovomucoid. Deglycosylation of hen ovomucoid was performed with the partly purified endo-beta-N-acetylglucosaminidase preparation, with the aid of contaminating beta-N-acetylhexosaminidase. The deglycosylated ovomucoid exhibited no changes in trypsin inhibitory activity but was very unstable to heat treatment in comparison with native ovomucoid. These results suggest that oligosaccharides of ovomucoid have an important role in the stabilization of the protein against heat.

Animals↗
PubMed1997

Xenopus cyclin A1 can associate with Cdc28 in budding yeast, causing cell-cycle arrest with an abnormal distribution of nuclear DNA.

BACKGROUND: Cyclins play a regulatory role in cell cycle progression, associated with cyclin-dependent kinases. We have investigated the structure-function relationships of cyclin A, mainly using Xenopus egg extracts in vitro. To further analyse the function and structure of cyclin A in vivo, we expressed Xenopus cyclin A1 in the budding yeast Saccharomyces cerevisiae. RESULTS: We herein show that vertebrate cyclin A1 can associate with endogenous Cdc28 to form histone H1 kinase. The growth of the yeast was inhibited by the expression of indestructible cyclin A1, but not by a non-Cdk binding cyclin A1 mutant. The induction of cyclin A1 expression in yeast caused cell cycle arrest with an abnormal distribution of nuclear DNA to the daughter bud. Suppressors of the cyclin A1-mediated growth arrest were identified as new alleles of the cdc28 mutation that reduced the binding of cyclin A1 and possessed different affinities for the cyclin-Cdc28 complexes. The temperature-sensitivity of the cdc28 mutation was thus preferentially suppressed by the endogenous cyclins CLN2 and CLB2. CONCLUSIONS: These results suggest that the Cdc28 protein kinase activity mediated by vertebrate cyclin A1 may be involved in the process of nuclear movement in the yeast, and thereby affect the dependence of the M phase on the completion of the S phase through a preferential binding affinity of the cyclin-Cdc28 complex.

Amino Acid Sequence↗
PubMed1996

Geographical distribution of the human polyomavirus JC virus type A and B and isolation of a new type from Ghana.

The JC polyomavirus (JCV) is ubiquitous in humans infecting children asymptomatically, then persisting in renal tissue. Since JCV DNA can be readily isolated from urine, it should be a useful tool with which to study the evolution of DNA viruses in humans. We showed that JCV DNA from the urine of Japanese, Taiwanese, Dutch and German patients can be classified into A and B types, based upon restriction fragment length polymorphisms (RFLPs). This work was extended in the present study. We established multiple JCV DNA clones from the UK, Spain, Italy, Sweden, South Korea, People's Republic of China, Malaysia, Indonesia, Mongolia, India, Sri Lanka, Saudi Arabia, Ethiopia, Kenya, Zambia, South Africa and Ghana. Using type-specific RFLPs, most clones except the four clones from Ghana were classified as either type A or B. We constructed a molecular phylogenetic tree for the Ghanaian clones and several representative type A and B clones. According to the phylogenetic tree, the Ghanaian clones constituted a major new group, tentatively named type C. From the findings presented here and elsewhere, the following conclusions were drawn: (i) type A is prevalent only in Europe; (ii) type B is found mainly in Asia and Africa; and (iii) type C is localized to part of Africa. Our findings should help to clarify how JCV evolved in humans.

Base Sequence↗
PubMed1995

[Study on middle ear ventilation using positional tympanometry--normal ear].

The middle ear is a cavity surrounded by solid bones, lined with mucosa, which has a gas-filled lumen. Cavernous organs such as the ear should have their own ventilation system under atmospheric pressure. The mechanism of ventilation in the middle ear has not been sufficiently clarified. Ventilation performed in the middle ear may be classified into two types: 1) passive ventilation via the Eustachian tube, required in cases of abnormal pressure and 2) unique physiological active ventilation of the middle ear performed under atmospheric pressure and not involving the Eustachian tube. The purpose of the present study is to prove the existence of this active ventilation under atmospheric pressure. The subjects were 50 normal ears and elevation of middle ear pressure in the lateral position (determined by positional tympanometry) was studied. The change in the peak level, on tympanometry, was used as an index. The results were continuously recorded every 12 seconds. The following results were obtained. 1. Middle ear pressure was elevated by changing from the sitting to the lateral position. Venous pressure was regarded as a causative factor in this pressure elevation. 2. The elevated middle ear pressure in the lateral position suggested gas production from mastoid cells of the middle ear. The observation that the middle ear pressure was stabilized with the increase in pressure, up to a level of 85-90 mm H2O, indicated the existence of gas leakage from the Eustachian tube and a mechanism for controlling gas production from the mastoid cells of the middle ear.

Acoustic Impedance Tests↗
PubMed1995

[Study on middle ear ventilation using positional tympanometry--post mastoidectomy ear].

The middle ear is a cavity surrounded by solid bone, lined with mucosa with a lumen filled with gas. To examine this unique ventilation system under atmospheric pressure, the middle ear pressure of 50 normal ears was previously examined. Positional tympanometry, whereby the middle ear pressure is increased as the subject assumes the lateral position under atmospheric pressure was used. As a result, (1) The middle ear pressure was elevated by the change from the sitting position to the lateral position. Venous pressure was regarded as causative factor of this pressure elevation. (2) The elevation of the middle ear pressure in the lateral position suggested gas production from the mastoid cells of the middle ear. In this study, a proportion of the mastoid cells were removed to resect a tumor of the internal acoustic meatus in conjunction with resection of an acoustic tumor. After resection the area was filled with fascia and fatty tissue. The middle ear pressure of each subject was monitored to determine the effect of a decrease in the mastoid cell volume on middle ear pressure. The results were continuously recorded every 12 seconds for the lower ear when the subjects were in the lateral position. The following results were obtained. (1) The elevation of the middle ear pressure due to positional change among subjects which had had acoustic tumors resected was noticeably greater than the elevation in normal ears. This is thought to have been the result of an elevation in cerebrospinal fluid pressure attributable to positional change, along with an elevation in intravenous pressure. (2) We made comparisons of increases in middle ear pressure 10 minutes after assuming the lateral position in 14 ears after acoustic tumor resection and in 21 normal ears. No noticeable differences were found in the middle ear pressure increases between the two groups despite the fact that the volume of the mastoid cells in the group that had tumors resected had been greatly reduced.

Acoustic Impedance Tests↗
PubMed1993

Pressor response to microinjection of clonidine into the hypothalamic paraventricular nucleus in conscious rats.

We have reported that intracerebroventricular (i.c.v.) injection of clonidine causes pressor response in conscious rats. To determine the effective brain site, cardiovascular responses induced by unilateral microinjection of clonidine into various hypothalamic nuclei of conscious rats were studied. Microinjection of clonidine (5-20 micrograms/0.5 microliter) into the paraventricular nucleus (PVN) of conscious rats dose-dependently produced a long-lasting pressor response with a decrease in heart rate, which mimicked the response to i.c.v. injection of clonidine. However, clonidine (10 micrograms) injection into various hypothalamic nuclei (anterior, posterior, ventromedial and dorsomedial nucleus) caused a small or no pressor response. In anesthetized rats, clonidine injected into the PVN induced a long-lasting depressor response concomitant with bradycardia. PVN pretreatment with the alpha 2-adrenoceptor antagonist, yohimbine (1 and 10 micrograms), dose-dependently inhibited the pressor response to PVN injected clonidine, but the alpha 1-adrenoceptor antagonist, prazosin (1 microgram), had no significant effect. Central (i.c.v.) pretreatment with the vasopressin (AVP) V1-receptor antagonist, [d(CH2)5Tyr(Me)]-AVP (0.5 and 2.0 micrograms), dose-dependently inhibited the pressor response to PVN injection of clonidine (10 micrograms), while systemic (i.v.) and local (intra-PVN injection) pretreatments with V1-receptor antagonist (2.0 micrograms) had no effect. These results suggest that the pressor response to microinjection of clonidine into the PVN of conscious rats is mediated by endogenous brain AVP, which is released by activation of alpha 2-adrenoceptors. It is also suggested that the PVN is a possible brain site for the pressor response to i.c.v. injected clonidine.

Adrenergic alpha-Antagonists↗
PubMed1993

Pulmonary clearance and toxicity of intratracheally instilled cupric oxide in rats.

Pulmonary clearance and toxicity of cupric oxide (CuO) dusts, which are probably formed in refining and smelting factories, were investigated. Groups of three rats received intratracheal (i.t.) instillation of CuO at a dose of 20 micrograms Cu/rat in time-course experiments (up to 7 days post-instillation). Other groups of three rats received i.t. instillation of CuO at doses of 2.5, 5, 10, 30, 50 and 100 micrograms Cu/rat and were killed at 2 days post-instillation in dose-effect experiments. Intratracheally instilled CuO particles were cleared from the lung with a half-time of 37 h. Copper binding metallothionein (MT) was induced in a dose-dependent manner and detected at 12 h to 3 days post-instillation. Rapid clearance of CuO from the lung and induction of MT at 12 h post-instillation suggest that CuO particles were solubilized and then cleared from the lung. The acute pulmonary toxicity of CuO was evaluated by cytological (numbers of macrophages and polymorphonuclear leukocytes), biochemical and elemental inflammatory indices (lactate dehydrogenase and beta-glucuronidase activities and protein, sulfur, phosphorus and calcium contents) in the bronchoalveolar lavage (BAL) fluid. These inflammatory indices peaked at 12 h to 3 days post-instillation, and increased with dose over the dose range, except for phosphorus content. Dose-effect relationships in BAL inflammatory indicators of CuO-injected (i.t.) groups were compared to those of CuSO4-injected (i.t.) groups. The results of the comparison indicated that there was no significant difference in acute inflammatory potency between CuSO4 (soluble form of Cu) and CuO (insoluble form of Cu) in the rat lung.

Air Pollutants, Occupational↗
PubMed1993

Performance test of PDM-101 electronic pocket dosimeters using a 60Co source.

The performance tests of one type (named PDM-101) of silicon semiconductor dosimeter were carried out by using a 60Co point source (approximately 500 kBq). The dosimeter responds to dose equivalents on the order of 0.02 microSv although measured data show a large error for values < 0.08 microSv. The deviation of measured dose equivalents from calculated ones was < 10% in the region > or = 0.08 microSv. The deviation of measured dose equivalent rates from calculated ones was generally < 10%. The average value of measured dose equivalents for 31 directional exposures without underside exposure was 0.92 +/- 0.06 of the calculated value. The difference of measured data for the front and back exposure was < 10%. The background and noise level of the dosimeter was 0.092 +/- 0.005 microSv h-1. All measured data showed that dosimeter response for radiation was symmetric between the front (left) and the back (right) sides of the dosimeter within 10% tolerance.

Cobalt Radioisotopes↗
PubMed1991

Prediction of degree of residual stenosis in coronary thrombolysis.

In order to predict the residual stenosis in coronary thrombolysis, the factors easily obtained from clinical history--age, gender, history of angina before acute myocardial infarction (AMI), family history, hypertension, diabetes, hypercholesterolemia, smoking, and interval between onset of AMI and recanalization--were observed in 114 patients with successful coronary thrombolysis. In 55 patients with angina before AMI, 29 patients had residual stenosis greater than or equal to 75% and 26 patients had residual stenosis less than 75%. In 59 patients without angina before AMI, 15 patients had residual stenosis greater than or equal to 75%, and 44 patients had residual stenosis less than 75%. The presence or absence of angina before AMI was the main variable that discriminated the groups of residual stenosis of more or less than 75%, which was the only significant independent variable to predict the residual stenosis. These data suggest that the presence of angina pectoris before AMI is likely to be associated with a significant degree of residual stenosis after thrombolysis.

Angina Pectoris↗
PubMed1991

A case of cardiac amyloidosis presenting with symptoms of exertional syncope.

A 54-year-old man presented with symptoms of exertional syncope. Cardiac amyloidosis was diagnosed by endomyocardial biopsy. Exercise tolerance test revealed a failure of increased heart rate followed by sinus arrest, associated with syncope. Autopsy revealed amyloid deposits in the sinoatrial node.

Amyloidosis↗
PubMed1990

Metabolism and pulmonary toxicity of intratracheally instilled cupric sulfate in rats.

Though copper (Cu)-handling workers are known to be at risk to develop metal fume fever and acute respiratory failure, very little is known about the metabolic fate and pulmonary toxicity of Cu compounds deposited in the lung. We have investigated time-course and dose-related changes in Cu contents, the production of metallothionein (MT) and inflammatory responses in the rat lung following intratracheal instillation of cupric sulfate (CuSO4). Intratracheally instilled Cu was cleared rapidly from the lung with a half-time of 7.5 h. Copper-binding MT was induced in the lung tissue following Cu instillation and the amount of MT increased with the dose of CuSO4. However, the production of MT contributed little to the accumulation of Cu in the lung. The pulmonary toxicity of CuSO4 was evaluated by examining time-course and dose-effect profiles of cytological and biochemical inflammatory indices (enzymes, protein and elements) retrieved in bronchoalveolar lavage fluids. These results revealed that the inflammatory indices reached maximum values in their activities and contents at 12 h to 3 days after instillation and a dose of 5 micrograms Cu/rat was sufficient to produce acute inflammatory responses in the rat lung.

Animals↗
PubMed1990

V-Y advancement flaps in the reconstruction of skin defects of the posterior heel and ankle.

A V-Y advancement pedicle flap including fascia has been used for reconstruction of soft-tissue defects of the posterior heel and ankle region. This flap has been used to cover 17 defects in 16 patients ranging in age from 4 to 58 years, and results have been good. We limited this application to patients without systemic disease and under 60 years of age and did not apply it to the elderly, debilitated, or systemic vascular damaged patients. There were no complications or loss of overlying skin, with the exception of one superficial tip necrosis of the flap. The results indicate the reliability and usefulness of this procedure in coverage of the posterior heel and ankle regions. It is a relatively quick and simple procedure that is without a free skin graft, and it involves only one stage that adequately corrects the skin defect at the posterior heel and ankle without prolonged splintings and results in negligible deformity of the donor site.

Adolescent↗
PubMed1990

[Shielding ability of lead loaded radiation resistant gloves].

The shielding ability of radiation resistant gloves was examined. The gloves are made of lead loaded (as PbO2) polyvinyl chloride resin and are about 0.4 mm in thickness (70 mg/cm2). Eleven test pieces were sampled from each of three gloves (total 33) and the transmission rates for radiations (X-ray or gamma-ray) through the test pieces were measured with radiation sources, 99mTc, 57Co, 133Ba, 133Xe and 241Am. The differences of the transmission rates for radiations by the positions of the gloves were smaller than 15%, and the differences by three gloves were smaller than 5% in the case of 60 keV and 141 keV radiations. The average transmission rates for radiations in the 33 test pieces were about 40% for 30 keV radiation, about 90% for 80 keV and 140 keV radiations. The shielding characteristic of the gloves is equivalent to about 0.026 mm thick lead plate.

Hand↗