PubMed Health⌕ Search

Biomedical subjects

K Shirahama

Publications and source records attributed to K Shirahama.

At least 19 recordsLinked to original sources
PubMed2004

Anomalous suppression of superfluidity in 4He confined in a nanoporous glass.

We explore the superfluidity of 4He confined in a porous glass, which has nanopores of 2.5 nm in diameter, at pressures up to 5 MPa. With increasing pressure, the superfluidity is drastically suppressed, and the superfluid transition temperature approaches 0 K at some critical pressure, Pc approximately 3.4 MPa. The feature suggests that the extreme confinement of 4He into the nanopores induces a quantum phase transition from a superfluid to a nonsuperfluid at 0 K and at Pc.

Journal Article↗
PubMed2001

Spirituality in nursing from a Japanese perspective.

The purpose of this study was to explore the concept of spirituality and its expression among persons in a Japanese farming community. It was found that spirituality was described as "living in harmony with nature and surrounding people." Common expressions of this spirituality were through faith and ways of worship, prayer, search for inner peace, hope and thanksgiving, including spiritual well-being. The latter was defined as showing thanks to nature, ancestors, and people; caring for surrounding people; and peacefully embracing the concept of death. To provide congruent spiritual care, it was suggested that nurses need to expand their own knowledge and understanding of spirituality; integrate spirituality in their nursing care; and improve communication with their clients and their families.

Adult↗
PubMed2000

Multiple duodeno-jejunal diverticula causing massive intestinal bleeding.

A case of massive intestinal blood loss from multiple duodeno-jejunal diverticula is described. A 39-year-old man was referred to our hospital because of recurrent bloody stool and worsening anemia. Upper and lower endoscopy, selective abdominal angiography, and radionuclide scanning were performed to seek the cause of the intestinal bleeding, but none of these studies revealed the source of bleeding. Small-bowel barium follow-through examination showed numerous diverticula in the distal duodenum and proximal jejunum. Excision of the duodenal diverticulum and resection of the involved portion of the jejunum cured the patient. On histopathological examination, an ulcerative lesion with an exposed vessel suggestive of the source of bleeding was seen in the resected duodenal diverticulum. Although duodeno-jejunal diverticula are rare, the importance of a careful search for this malformation in a patient with intestinal blood loss is stressed.

Adult↗
PubMed2000

Three-dimensional measurement of rolling in tetraplegic patients.

OBJECTIVE: To investigate the differences between traumatic tetraplegic patients who can roll and those who cannot. DESIGN: Motion analysis using 3-dimensional measurement. SETTING: Rehabilitation centers in southwestern Japan. PARTICIPANTS: Nineteen male participants, all of whom had traumatic C6 complete injury. METHODS: We used an electromagnetic device to examine the degree of spinal movement in axial rotation during rolling (shifting from supine to side lying). This system (3-Space Win) measures the position and orientation of sensors in space. Two sensors were mounted on a subject over the spinous process of T1 and L5. RESULTS: The spinal rotation of patients who could not roll was significantly lower than that of patients who could roll. (The average rotation of non-rollers was 31.5+/-17.5 degrees, while the average rotation of rollers was 66.3+/-17.3degrees). In this study, there were no statistically significant differences in the members of the two groups in terms of age, height, weight or time after injury. CONCLUSION: Rolling requires greater and adequate flexibility in the back of tetraplegic patients.

Adult↗
PubMed2000

[Psychological characteristics of unsuccessful pilot trainees].

Some pilot trainees can not pass flight examinations and are obliged to give up their flight training because of their insufficient technical skills. We investigated their results of group Rorschach test (a multiple-choice test with ink blots which are similar to those for face-to-face Rorschach test). Subjects were 20 male pilot trainees (F (fail) group: mean age 22.6 +/- 1.5 years) who were obliged to give up their flight trainings between 1985 and 1996 because of their insufficient technical skills. The control group was made up of 125 male pilot trainees (P (pass) group: mean age 22.4 +/- 1.7 years) who were the successful classmates of the unsuccessful trainees. We investigated the differences of the results of group Rorschach test given for employment screening between the two groups. All results of the scores in group Rorschach test were within normal limits both in P group and F group. There, however, were following significant differences between the two groups: (1) F group showed more Key- responses than P group (F group: 4.9 +/- 2.1 P group: 3.4 +/- 2.0, p<0.01). (2) F group showed more k responses than P group (F group: 0.2 +/- 0.4 P group: 0.02 +/- 0.1, p<0.01). (3) P group showed more FC' responses than F group (F group: 1.4 +/- 1.0 P group: 2.2 +/- 1.2, p<0.01). (4) F group showed more cF responses than P group (F group: 1.6 +/- 1.2 P group: 1.0 +/- 0.9, p<0.05). (5) P group showed higher form level than F group (F group: 120.6 +/- 15.8 P group: 128.2 +/- 12.6, p<0.05). The pilot trainees in F group were suggested to have vulnerability to be nervous and anxious in an inexperienced situation, to decline their ability to cope objectively and effectively with a new situation, and to increase desire for dependence upon others.

Adaptation, Psychological↗
PubMed1999

Binding of Photosurfactant (4-butyl-azobenzene-4'-oxyethyltrimethylammonium bromide) to Polyelectrolyte.

The binding of a photosurfactant, 4-butyl-azobenzene-4'-oxyethyltrimethyl ammonium bromide (BZTABr), to a linear polymer, sodium poly(2-acrylamide-2-methylpropane sulfonate) (PAMPS), has been studied by using a surfactant selective electrode. The photosurfactant undergoes a trans-cis transition on UV/vis irradiation. The binding behavior changes by varying the composition of the trans and cis forms in the solution. The ideal mixing-ideal cooperative binding model we had proposed previously for the binding of binary surfactants was applied to successfully predict the binding isotherms and the critical aggregation concentrations of the present systems. The binding of a trans-cis mixture of BZTABr to a polymer is analogous to the ideal mixed micelle formation. A sort of synergetic effect was found in the binding process. Copyright 1999 Academic Press.

Journal Article↗
PubMed1998

Hepatocyte growth factor stimulates DNA synthesis in rat preneoplastic hepatocytes but not in liver carcinoma cells.

BACKGROUND & AIMS: It is not well clarified whether hepatocyte growth factor (HGF) stimulates the growth of preneoplastic hepatocytes and liver carcinoma cells in vivo. The effect of HGF on in vivo DNA synthesis in these cells and also its effect on tyrosine phosphorylation of the HGF receptor protein (c-Met) in liver carcinoma were examined. METHODS: Lesions were induced in rats using 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB). The rats were given intravenous recombinant human HGF or vehicle, and DNA synthesis was assessed by the 5-bromo-2'-deoxyuridine labeling index. Tyrosine phosphorylation of c-Met by HGF was analyzed by Western blot. RESULTS: The labeling indices were significantly higher in the HGF group than in the vehicle control group in altered foci and hyperplastic nodules (preneoplastic hepatic lesions). No significant differences in the labeling indices were observed between the two groups with carcinoma. Tyrosine phosphorylation of c-Met in carcinoma cells was unaffected by HGF administration. CONCLUSIONS: HGF promotes the growth of preneoplastic hepatocytes but does not affect the growth of liver carcinoma cells in 3'-Me-DAB-treated rats.

Animals↗
PubMed1997

Mutational analysis of Csc1/Vps4p: involvement of endosome in regulation of autophagy in yeast.

In the yeast Saccharomyces cerevisiae, autophagy, a bulk protein degradation in the vacuole, is induced in response to nutrient starvation. In a screen for mutations that result in induction of autophagy even in the presence of nutrients, we have isolated four mutants representing two csc complementation groups. These mutants induce autophagy of which activity is represented by activation of truncated alkaline phosphatase that is designed to be expressed in the cytosol. CSC1 was cloned by complementation of loss of viability phenotype of csc1-1 mutant and shown to be identical to END13/VPS4/GRD13. Though csc1-1 mutation is recessive, cells of delta csc1 do not induce autophagy in rich media, suggesting that csc1-1 allele is not a complete loss-of-function. Csc1p is a member of novel ATPase family named AAA protein including Sec18p/NSF, Cdc48p/p97, and Pas8p. Mutation site in csc1-1 is found in the SRH region that is highly conserved among AAA proteins. Cells of csc1-1 show sorting defect of CPY and the appearance of the class E compartment. These mutant phenotypes suggest the role of the protein that is involved in the traffic among the Golgi, endosome, and the vacuole in autophagy.

Adenosine Triphosphatases↗
PubMed1996

Vacuolar function in the phosphate homeostasis of the yeast Saccharomyces cerevisiae.

We studied physiological roles of the yeast vacuole in the phosphate metabolism using 31P-in vivo nuclear magnetic resonance (NMR) spectroscopy. Under phosphate starvation wild-type yeast cells continued to grow for two to three generations, implying that wild-type cells contain large phosphate pool to sustain the growth. During the first four hours under the phosphate starved condition, the cytosolic phosphate level was maintained almost constant, while the vacuolar pool of phosphate decreased significantly. 31P-NMR spectroscopy on the intact cells and perchloric acid (PCA) extracts showed that drastic decrease of polyphosphate took place during this phase. In contrast, delta slp1 cells, which were defective in the vacuolar compartment, thus lacked polyphosphate, ceased their growth immediately when they faced to phosphate starvation. Taken together, we conclude that vacuolar polyphosphate provides an active pool for phosphate and is mobilized to cytosol during phosphate starvation and sustained cell growth for a couple rounds of cell cycle.

Cytosol↗
PubMed1993

[An operative case of empyema necessitatis].

A case of empyema necessitatis presenting a mass in the retroperitoneal space is reported. Computer tomography preoperatively revealed the transdiaphragmatic abscess with calcified capsule. The operation was performed by means of resection of the abscess together with overlying ribs. Dead space after resection of the lesion was filled up with intercostal muscles. Empyema necessitatis is rare after introduction of antituberculous drugs. However, recognition of this disease is necessary for an appropriate surgical management. Total resection of the abscess followed by filling of the dead space with the intercostal muscles should be considered as a useful alternative method.

Aged↗
PubMed1991

Effect of inhalation anesthetics on swimming activity of artemia salina.

The swimming movement of artemia salina in the artificial sea water was measured by using the video camera system in the absence and presence of anesthetics, i.e. enflurane, halothane, and isoflurane. The movement of artemia looked random at a glance but the obtained distribution curve for the swimming speed was skewed toward the high speed side somewhat resembling a Maxwellian distribution curve seen in the statistics of ideal gases. When anesthetic were added, the distribution curve became sharpened and shifted to the low speed side, which is similar to a behavior of ideal gases when they are cooled down. The mean swimming-speed was decreased eventually leading to an irreversible death with increasing the anesthetic dose. The activity was analyzed by using the hydrodynamic equation. The ED(50), which is a dose that causes a 50% reduction in the activity, of all anesthetics used in this study was quite similar to the MAC values for human. It was also suggested that an interaction between anesthetics and artemia was highly cooperative since the larger Hill coefficients were obtained for all three anesthetics used.

Journal Article↗
PubMed1987

Origin of calcium-induced minimum in bulk compressional modulus of lipid membranes. Configurational entropy of adsorbed Ca2+.

Addition of Ca2+ to a dipalmitoylphosphatidylcholine lamellar system decreases the bulk compressional modulus (increases compressibility) of the membrane (S. Aruga, R. Kataoka and S. Mitaku, Biophys. Chem. 21 (1985) 265). The bulk modulus was reported to show a minimum value at 10 mM Ca2+ within the temperature range 20-45 degrees C. In the present report, the occurrence of this minimum in the bulk modulus is explained quantitatively as a result of fluctuation in the number of Ca2+ adsorbed onto the lipid bilayer surface. From this theory, the change in apparent molal volume of Ca2+ upon surface adsorption is estimated to be 5.7 cm3 mol-1, which appears to be a reasonable value. The number of adsorbed Ca2+ at the concentration where the bulk modulus assumes the minimum value is half of the number of allowable adsorption sites on lipid membranes. The configurational entropy of the adsorbed Ca2+ attains a maximum at the minimum point.

1,2-Dipalmitoylphosphatidylcholine↗