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Biomedical subjects

M Yasui

Publications and source records attributed to M Yasui.

At least 55 records · Page 3Linked to original sources
PubMed2000

[A case of adenocarcinoma complicated with massive leukocytosis and hypercalcemia].

A 66-year-old man was admitted to our hospital complaining of non-productive cough and low-grade fever. Chest X-ray examination revealed a mass shadow in the right hilum. Transbronchial lung biopsy of the tumor mass yielded a diagnosis of adenocarcinoma. Despite repeated chemotherapy using CDDP and VDS, metastasis to the right adrenal gland and right femur occurred, and was accompanied by hypercalcemia and hypophosphatemia. Serological study revealed elevated levels of PTH-rP and G-CSF. Six months after adenocarcinoma was diagnosed, multiple skin metastases of the cancer were observed. Immunohistochemical staining for PTH-rP and G-CSF indicated that production of cytokines had caused a paraneoplastic syndrome including hypercalcemia and leukocytosis. It appeared that the elevation of G-CSF was induced by IL-6 produced from PTH-rP in cancer tissue. Documentation of similar cases is required.

Adenocarcinoma↗
PubMed1999

TEMPO radicals showing magnetic interactions. II. 4-(Benzylideneamino)-TEMPO and related compounds.

X-ray crystal structure analyses were performed on 4-(Ar-methyleneamino)-TEMPO radicals at room temperature (TEMPO = 2,2,6,6-tetramethylpiperidyl-1-oxyl): Ar = Ph [4-(benzylideneamino)-2,2,6,6-tetramethylpiperidyl-1-oxyl], 4-MeS-Ph [2,2,6,6-tetramethyl-4-(4-methylthiobenzylideneamino)piperidyl-1-oxyl], 4-Me-Ph [4-(4-methylbenzylideneamino)-2,2,6,6-tetramethylpiperidyl-1-oxyl], 4-PhO-Ph [2,2,6,6-tetramethyl-4-(4-phenoxybenzylideneamino)piperidyl-1-oxyl], 4-MeSO(2)-Ph [2,2,6,6-tetramethyl-4-(4-methylsulfonylbenzylideneamino)piperidyl-1-oxyl], 3-Py [2,2,6,6-tetramethyl-4-(3-pyridylmethylideneamino)piperidyl-1-oxyl] and 2-Naph [2,2,6,6-tetramethyl-4-(2-naphthylideneamino)piperidyl-1-oxyl]. Structures of Ph and 4-Me-Ph derivatives were also determined at 100 K. Some of these crystals have been revealed to show intermolecular ferromagnetic interactions at an extremely low temperature. Structural features of crystals of Ph, 4-MeS-Ph and 3-Py derivatives, which show ferromagnetic interactions, are very similar to each other. In these crystals, O atoms are arranged to form a sheet. The ferromagnetic interactions are considered to be transferred through O.H van der Waals' interactions of the beta-H atoms of the neighboring TEMPO rings within the sheet. Between O.O sheets, the aryl groups are arranged in a herringbone manner. The crystal structure of the 4-Me-Ph derivative, which shows an antiferromagnetic interaction, is also pseudo-isostructural with those of Ph, 4-MeS-Ph and 3-Py derivatives, while the arrangement of the aryl groups is different. The packing mode of the crystals of the 4-MeSO(2)-Ph derivative, of which the Weiss constant straight theta is nearly zero, is very different from those of the other derivatives showing magnetic interactions. The fact that the crystal structure of the paramagnetic 4-MeSO(2)-Ph derivative does not show the O.O sheet structure accompanying the O.beta-H interactions indicates that the intermolecular ferromagnetic interactions through beta-H atoms within the O.O sheet are important for these TEMPO radical crystals.

Journal Article↗
PubMed1999

Rapid gating and anion permeability of an intracellular aquaporin.

Aquaporin (AQP) water-channel proteins are freely permeated by water but not by ions or charged solutes. Although mammalian aquaporins were believed to be located in plasma membranes, rat AQP6 is restricted to intracellular vesicles in renal epithelia. Here we show that AQP6 is functionally distinct from other known aquaporins. When expressed in Xenopus laevis oocytes, AQP6 exhibits low basal water permeability; however, when treated with the known water channel inhibitor, Hg2+, the water permeability of AQP6 oocytes rapidly rises up to tenfold and is accompanied by ion conductance. AQP6 colocalizes with H+-ATPase in intracellular vesicles of acid-secreting alpha-intercalated cells in renal collecting duct. At pH less than 5.5, anion conductance is rapidly and reversibly activated in AQP6 oocytes. Site-directed mutation of lysine to glutamate at position 72 in the cytoplasmic mouth of the pore changes the cation/anion selectivity, but leaves low pH activation intact. Our results demonstrate unusual biophysical properties of an aquaporin, and indicate that anion-channel function may now be explored in a protein with known structure.

Animals↗
PubMed1999

Aquaporin-6: An intracellular vesicle water channel protein in renal epithelia.

All characterized mammalian aquaporins (AQPs) are localized to plasma membranes where they function chiefly to mediate water transport across cells. Here we show that AQP6 is localized exclusively in intracellular membranes in renal epithelia. By using a polyclonal antibody to the C terminus of AQP6, immunoblots revealed a major 30-kDa band in membranes from rat renal cortex and medulla. Endoglycosidase treatment demonstrated presence of an intracellular high mannose glycan on each subunit. Sequential ultracentrifugation of rat kidney homogenates confirmed that AQP6 resides predominantly in vesicular fractions, and immunohistochemical and immunoelectron microscopic studies confirmed that >98% of AQP6 is located in intracellular membrane vesicles. In glomeruli, AQP6 is present in membrane vesicles within podocyte cell bodies and foot processes. In proximal tubules, AQP6 is also abundant in membrane vesicles within the subapical compartment of segment 2 and segment 3 cells, but was not detected in the brush border or basolateral membranes. In collecting duct, AQP6 resides in intracellular membrane vesicles in apical, mid, and basolateral cytoplasm of type A intercalated cells, but was not observed in the plasma membrane. Unlike other members of the AQP family, the unique distribution in intracellular membrane vesicles in multiple types of renal epithelia indicates that AQP6 is not simply involved in transcellular fluid absorption. Moreover, our studies predict that AQP6 participates in distinct physiological functions such as glomerular filtration, tubular endocytosis, and acid-base metabolism.

Amidohydrolases↗
PubMed1999

TEMPO radicals showing magnetic interactions. I. 4-(4-Halobenzylideneamino)TEMPO and related compounds.

X-ray crystal structure analyses of the 4-(4-halobenzylideneamino)TEMPO (TEMPO = 2,2,6,6-tetramethylpiperidyl-1-oxyl) radicals 4-(4-fluorobenzylideneamino)-2,2,6,6-tetramethylpiperidyl-1-oxyl, 4-(4-chlorobenzylideneamino)-2,2,6,6-tetramethylpiperidyl-1-oxyl, 4-(4-bromobenzylideneamino)-2,2,6,6-tetramethylpiperidyl-1-oxyl and 4-(4-iodobenzylideneamino)-2,2,6,6-tetramethylpiperidyl-1-oxyl, and other 4-Ar-CH=N-TEMPO [Ar = 4-Ph-Ph, 2,2,6,6-tetramethyl-4-(4-phenylbenzylideneamino)piperidyl-1-oxyl, 4-Py, 2,2,6,6-tetramethyl-4-(4-pyridylmethylideneamino)piperidyl-1-oxyl, and 3,5-diCl-Ph, 4-(3,5-dichlorobenzylideneamino)-2,2,6,6-tetramethylpiperidyl-1-oxyl] radicals have been performed at room temperature. Some of these radicals show intermolecular ferromagnetic interactions at extremely low temperatures. X-ray analysis revealed that crystals of the 4-I-Ph derivative showed two modifications [(a) and (b)]; measurements of the magnetic properties of these crystals showed a ferromagnetic transition at an extremely low temperature for modification (a) and an antiferromagnetic interaction for modification (b). The structural features of these TEMPO radical crystals can be classified into three groups: (i) the crystal structures of the 4-Cl-Ph, 4-I-Ph(a) and 4-Ph-Ph derivatives, which show a ferromagnetic transition; (ii) the structures of the 4-Br-Ph and 4-Py derivatives, which show a ferromagnetic interaction (straight theta > 0); (iii) miscellaneous: the antiferromagnetic 4-F-Ph and 4-I-Ph(b) derivatives (straight theta < 0) and the ferromagnetic 3,5-diCl-Ph (straight theta > 0) derivative. Sheet-like arrangements of O atoms and intra-sheet interactions through the CH(2) or CH(3) groups of the TEMPO rings are related to the mechanisms of the ferromagnetic interactions.

Journal Article↗
PubMed1999

Presumption of a suspect based on the skin fragment attached the rope.

An eight-year-old girl (second-year of elementary school) was strangled in an irrigation canal near her house and was left unconscious. The body of a male who hanged himself to death was discovered on the next day. The hanging mark on the neck of the man and the ligature mark on the neck of the girl were caused by double nooses of a rope, the width of the rope mark was nearly the same, and similar Zwischenkammblutung (subcutaneous bleeding in the middle of the rope mark) was observed in both cases. Therefore, we evaluated whether the marks were caused by the same rope. As a result, the DNA type of the skin fragment (keratinized epithelial cells) attached to the rope used by the man to hang himself was identical to that of the girl. On the basis of this evidence, the man who hanged himself to death was presumed to be the suspect who strangled the girl.

Journal Article↗
PubMed1999

Comparison of bronchoalveolar lavage cell findings in complete-resolution pneumonia and delayed-resolution pneumonia.

BACKGROUND: In some patients with bacterial pneumonia, the resolution of chest radiograph shadows are delayed. There have been many clinical and pathological studies on delayed-resolution pneumonia (DR). However, there are no reports concerning inflammatory cell findings of bronchoalveolar lavage (BAL) fluid in patients with DR. We compared the BAL fluid cell findings in patients with DR with those in patients with complete-resolution pneumonia (CR). METHODS: The subjects included six patients whose chest radiograph shadows were completely resolved within 2 weeks after an appropriate antibiotic administration (CR), and nine patients whose chest radiograph shadows were unresolved more than 2 weeks after the treatment (DR). BAL was done 2-3 weeks after the antibiotic treatment in both groups. We compared differential counts and lymphocyte subsets in BAL fluid among patients with CR, patients with DR, and asymptomatic subjects. RESULTS: There were no significant differences in BAL fluid cell findings between CR groups and asymptomatic groups. On the other hand, the percentages of lymphocytes, neutrophils and eosinophils in DR group were significantly increased compared with those in CR and normal groups. There was no significant difference in the CD4+/CD8+ ratio of BAL lymphocytes among the three groups. CONCLUSIONS: It is suggested that infiltration of inflammatory cells in the lung exists in DR, despite the disappearance of inflammatory reaction in the peripheral blood.

Adult↗
PubMed1999

Arginine vasopressin stimulates phosphorylation of aquaporin-2 in rat renal tissue.

Aquaporin-2 (AQP2), the protein that mediates arginine vasopressin (AVP)-regulated apical water transport in the renal collecting duct, possesses a single consensus phosphorylation site for cAMP-dependent protein kinase A (PKA) at Ser256. The aim of this study was to examine whether AVP, and other agents that increase cAMP levels, could stimulate the phosphorylation of AQP2 in intact rat renal tissue. Rat renal papillae were prelabeled with 32P and incubated with vehicle or drugs, and then AQP2 was immunoprecipitated. Two polypeptides corresponding to nonglycosylated (29 kDa) and glycosylated (35-48 kDa) AQP2 were identified by SDS-PAGE. AVP caused a time- and dose-dependent increase in phosphorylation of both glycosylated and nonglycosylated AQP2. The threshold dose for a significant increase in phosphorylation was 10 pM, which corresponds to a physiological serum concentration of AVP. Maximal phosphorylation was reached within 1 min of AVP incubation. This effect on AQP2 phosphorylation was mimicked by the vasopressin (V2) agonist, 1-desamino-[8-D-arginine]vasopressin (DDAVP), or forskolin. Two-dimensional phosphopeptide mapping indicated that AVP and forskolin stimulated the phosphorylation of the same site in AQP2. Immunoblot analysis using a phosphorylation state-specific antiserum revealed an increase in phosphorylation of Ser256 after incubation of papillae with AVP. The results indicate that AVP stimulates phosphorylation of AQP2 at Ser256 via activation of PKA, supporting the idea that this is one of the first steps leading to increased water permeability in collecting duct cells.

Animals↗
PubMed1999

[A case of intra-arterial infusion chemotherapy for liver metastases of breast cancer].

A 55-year-old woman was seen in our clinic for liver metastases of breast cancer. She underwent a standard radical mastectomy in June, 1987. Five years and 3 months after the operation, multiple bone metastases were found on bone scintigram and 10 years after the operation multiple liver metastases on CT. She was treated with a combination of intra-arterial chemotherapy using 20-30 mg/body epirubicin every 2 weeks and chemo-endocrine therapy using medroxyprogesterone acetrate (MPA) 600 mg/day + 5'-DFUR 600 mg/day. The treatment seemed to be very useful. The liver metastases regressed by 99% in size, and the duration of response was 9 months. Bone metastases did not progress from the treatment.

Administration, Oral↗
PubMed1998

N-copine: a novel two C2-domain-containing protein with neuronal activity-regulated expression.

Neuronal activity is often associated with changes in gene expression. By a two-dimensional cDNA-display system, restriction landmark cDNA scanning, we identified a novel gene whose expression in the hippocampus was up-regulated by kainate stimulation. The mRNA expression was detected only in brain and up-regulated by the stimulation evoking CA3-CA1 long-term potentiation. The encoded protein contains two copies of C2-domain, known as the Ca2+-binding domain of PKC-gamma, and shows 49% identity with human copine I. We designated this protein N-copine (neuronal-copine). N-copine may have a role in synaptic plasticity.

Amino Acid Sequence↗
PubMed1998

Aluminum decreases the magnesium concentration of spinal cord and trabecular bone in rats fed a low calcium, high aluminum diet.

Current epidemiological surveys in the Western Pacific (Guam, and Kii Peninsula and West New Guinea) have suggested that low calcium (Ca), magnesium (Mg) and high aluminum (Al) and manganese (Mn) in river, soil and drinking water may be implicated in the pathogenetic process of foci of amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia (PD). The condition of unbalanced minerals was experimentally mimicked in this study using rats. Male Wistar rats, weighing 200 g, were maintained for 60 days on the following diets: (A) standard diet, (B) low Ca diet, (C) low Ca diet plus high Al. Magnesium concentrations were determined in spinal cord and trabecular bone using inductively coupled plasma emission spectrometry (ICP). In the experimental group maintained on a low Ca, high Al diet, magnesium concentration of the spinal cord was lower than the group fed a standard diet. Also, magnesium concentration of lumbar vertebra showed lower values in the experimental group fed a low Ca, high Al diet than did those on a standard diet or low Ca diet without supplemental aluminum. Our data indicate that low Ca, high Al diet influences Mg concentration in bone and central nervous system (CNS) tissues and that a low Ca, high Al diet diminishes Mg in bone and CNS tissues, thereby inducing loss of calcification in bone and degeneration of CNS tissue due to alteration of the normal biological effects of Mg.

Aluminum↗
PubMed1998

Cough receptor sensitivity to capsaicin and tartaric acid in patients with Mycoplasma pneumonia.

There has been no detailed study of cough sensitivity during acute lower respiratory infection. The aim of this study was to clarify cough sensitivity in Mycoplasma pneumonia, which is a well known acute lower respiratory infection with persistent nonproductive cough. We examined cough sensitivity to inhaled capsaicin and tartaric acid in both the acute and the convalescent phases of Mycoplasma pneumonia, cell differentials in bronchoalveolar lavage fluid, and pathologic findings of transbronchoscopic bronchial biopsy specimens. Although dry cough was observed in all patients during Mycoplasma pneumonia, cough sensitivity in the acute phase [capsaicin: 19.8 (GSEM, 0.214) microM, tartaric acid: 0.26 (GSEM, 0.356) M] were not enhanced compared with those in both control subjects [capsaicin: 27.9 (GSEM, 1.24) microM, tartaric acid: 0.316 (GSEM, 0.079) M] and patients in the convalescent phase [capsaicin: 15.7 (GSEM, 0.219) microM, tartaric acid: 0.50 (GSEM, 0.326) M] when all symptoms including cough had disappeared. The percentage of lymphocytes and neutrophils in bronchoalveolar lavage fluid BALF was significantly greater than in the control subjects, and lymphocyte-dominant bronchitis was observed in biopsied specimens. We conclude that cough threshold to inhaled capsaicin or tartaric acid was not enhanced during acute Mycoplasma pneumonia with lymphocyte-predominant bronchitis. This is the first report examining cough sensitivity in patients with acute lower respiratory infection with pneumonia.

Adult↗
PubMed1998

CD34+ progenitor cell transplantation from two HLA-mismatched healthy fathers to two infants with severe aplastic anemia.

Pluripotent stem cells of hematopoiesis are included among CD34+ cells in the blood and bone marrow. After granulocyte-colony stimulating factor (G-CSF) mobilization, 1-2% of the mononuclear cells in the blood are CD34+ cells, which can be obtained by leukapheresis. We performed CD34+ progenitor cell transplantation in two children with severe aplastic anemia (SAA) who lacked HLA-matched donors. The donors were treated with G-CSF, 600 micrograms/body/day subcutaneously, for 4-5 days. CD34+ cell selection was performed from the apheresis concentrate with mouse anti-CD34 antibody 9C5 and magnet beads coated with sheep anti-mouse IgG1. After the transplantation, the patients received tacrolimus to prevent graft-versus-host disease (GVHD). G-CSF was given to both patients. A mean number of 4.96 x 10(6) CD34+ cells per kilogram of body weight were transplanted. The hematopoietic recovery after the CD34+ cell transplantation was rapid, except for platelets, and acute GVHD was less than or equal to grade I. Case 1, who demonstrated mixed chimerism, anemia and thrombocytopenia after the graft, received a second transplant with intensified preconditioning, and now sustains complete and stable hematopoiesis after a follow-up of 314 days posttransplant. Although Case 2 showed early rejection and received a second transplant, sustained engraftment was never achieved. However, the patient's own hematopoiesis appeared. For SAA patients who do not have HLA-matched donors, this type of approach seems to be a feasible and useful method. However, an intensified preconditioning regimen to overcome the high likelihood of rejection should be employed.

Adult↗
PubMed1998

Bronchoalveolar lavage cell findings in three types of eosinophilic pneumonia: acute, chronic and drug-induced eosinophilic pneumonia.

There are clinically different types of eosinophilic pneumonia (EP) but no study to date has compared pulmonary inflammatory cells between different types of EP, such as acute eosinophilic pneumonia (AEP), chronic eosinophilic pneumonia (CEP) and drug-induced eosinophilic pneumonia (drug-EP). The present study compared bronchoalveolar lavage fluid (BALF) cell findings to elucidate whether the profiles of the pulmonary inflammatory cells were different among the three types of EP. Clinical records of 28 patients with EP, consisting of eight AEP patients, 10 CEP patients and 10 drug-EP patients, were examined retrospectively. The differential cell counts, the CD4+/CD8+ ratio of lymphocytes, the percentage of HLA-DR+ in CD4+ and CD8+ lymphocytes, and the mean number of nuclear segmentations in cosinophils in BALF were compared among the three types of EP. The numbers of total cells, lymphocytes, neutrophils and eosinophils in BALF from patients with AEP were increased compared with those from normal subjects, and patients with CEP and drug-EP. The CD4+/CD8+ ratio of the BALF lymphocytes in patients with AEP, which exceeded 1.0 in all patients, was significantly higher than that in normal subjects. The percentages of HLA-DR+ cells in CD8+ lymphocytes in BALF from patients with CEP were significantly higher than those from patients with AEP and drug-EP. There was no significant difference in the mean number of nuclear segmentations in eosinophils in BALF among the three types of EP. The BALF cell findings in patients with EP showed some characteristics in accordance with type of EP. It is suggested that pulmonary neutrophils and lymphocytes, rather than eosinophils, may be related to the pathogenesis of the different types of EP.

Acute Disease↗
PubMed1998

Atopy in cough sensitivity to capsaicin and bronchial responsiveness in young females.

We have shown previously that female sex is a determinant of cough sensitivity to inhaled capsaicin, but the relationship between atopy and the cough sensitivity has not been examined. The capsaicin cough threshold, defined as the lowest concentration of capsaicin causing five or more coughs, nonspecific bronchial responsiveness, defined as the provocative concentration of methacholine causing a 20% fall in the forced expiratory volume in one second (PC20), total immunoglobulin E (IgE) and specific IgEs to eight common aeroallergens (house dust 1, 2 and 6, Dermatophagoides pteronyssinus and D. farinae, Japanese cedar, ragweed and orchard grass) in the serum were measured in 71 nonsmoking, healthy young women aged 20.6+/-0.1 yrs (mean+/-EM). A structured interviewer-led questionnaire on allergic diseases revealed that one and six subjects had mild current and past asthma, respectively. These seven subjects were excluded from the data analysis. PC20 was significantly lower in 42 subjects showing a positive specific IgE than in 22 subjects showing a negative specific IgE to any of the eight allergens (p<0.05), while the capsaicin cough threshold was not significantly different between the subgroups. PC20 was significantly lower in subjects with positive specific IgE to Dermatophagoides and house dust, but not to the three kinds of pollen examined. It was confirmed that atopy indicated by specific immunoglobulin E to mite-related antigens, but not to pollen antigens, is associated with nonspecific bronchial responsiveness, and it is suggested that atopy is not a determinant of airway cough sensitivity in healthy, nonasthmatic subjects.

Adult↗
PubMed1998

[Efficacy of multidirection MRCP].

Pancreatobiliary system has complex and thin structure except for gallbladder, thereby MRCP having lower spatial resolution gives sufficient information compared with the direct cholangiopancreatography. Multidirection MRCP using HASTE sequence obtains the data in plane to compensate the lower spatial resolution, thus high detectability of all over pancreatobiliary system is performed in a few minutes. This technique overcomes the demerits pointed by former investigators and gives sufficient information to diagnose the pancreatobiliary diseases.

Biliary Tract↗