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Biomedical subjects

S Kawamura

Publications and source records attributed to S Kawamura.

At least 109 records · Page 6Linked to original sources
PubMed1999

[Public health nurses' disaster responses for intractable neurological patients at home].

OBJECTIVE: This paper describes the 1995 Hanshin-Awaji Earthquake experience of the local public health nurses. The purpose of the study was to identify problems regarding assistance of intractable neurological patients at home during and after the earthquake and to discuss ways to improve future local disaster responses by public health nurses for those patients. METHODS: Approximately 2 hours of a group interview of public health nurses from 2 public health centers in Kobe City was conducted in August, 1996. Interview data was collected via audio-tape and transcribed. The data was organized according to phases of the earthquake. The acute phase of the earthquake disaster ended within 72 hours. The data was then analyzed to identify problems in assisting intractable neurological home patients in order to discuss disaster responses by public health nurses. RESULTS: There was a delay in confirming the safety of and providing needed assistance for intractable neurological patients at home by public health nurses. During the first 3 days after the earthquake, the majority of public health nurses were unable to commute to work due to the shutdown of transportation systems. In addition, nurses, who were able to come to work, were preoccupied with treating earthquake casualties and distributing medical supplies. Other factors associated with the delay included the following: lack of a registration list for intractable neurological patients at home; lack of close contacts between public health nurses and patients, and between public health nurses and patient support groups; and sparing nurses for guiding volunteers and for coordinating between shelters and hospitals. CONCLUSION: Measures to improve future disaster responses are as follows: a) teaching patients and their families how to safeguard against disaster; b) preparing registration lists; c) establishing support networks and cooperating with network members; and d) upon disaster, assigning some nurses to assess the needs of patients.

Disaster Planning↗
PubMed1998

Purification and molecular cloning of a novel calcium-binding protein, p26olf, in the frog olfactory epithelium.

Olfactory adaptation requires the change of intracellular calcium concentration during stimuli. To contribute in the study of the molecular mechanism of calcium-dependent regulations in olfactory receptor cells, we isolated a novel 26-kDa Ca2+-binding protein named p26olf from the frog olfactory epithelium after four chromatographical steps. Based on the partial amino acid sequences of the proteolysed fragments of p26olf, we obtained a cDNA clone that encodes p26olf. The analysis of its amino acid sequence revealed that p26olf consists of two S-100-like regions aligned sequentially with a calculated molecular mass of 24,493. Northern blot analysis showed that p26olf is expressed in the frog olfactory epithelium and also in other tissues. Immunoreactivity against p26olf was detected in the cilia layer of the olfactory epithelium. These results suggest that p26olf is a dimeric form of S-100 proteins and is involved in the olfactory transduction or adaptation.

Adaptation, Physiological↗
PubMed1998

Investigation of the structural basis for thermostability of DNA-binding protein HU from Bacillus stearothermophilus.

Site-directed mutagenesis was used to identify amino acid residues essential for the thermostability of the DNA-binding protein HU from the thermophile Bacillus stearothermophilus (BstHU). Two mutants, BstHU-A27S and BstHU-V42I, in which Ala27 and Val42 in BstHU were replaced by the corresponding amino acids Ser27 and Ile42, respectively, in the homologue from a mesophile B. subtilis (BsuHU), were less stable than the wild-type BstHU (63.9 degreesC), showing Tm values of 58.4 degreesC and 60.1 degreesC, respectively, as estimated by circular dichroism (CD) analysis at pH 7.0. The denaturation of two mutants was further characterized using differential scanning calorimetry; the Tm values obtained by calorimetric analysis were in good agreement with those estimated by CD analysis. The results suggest that Ala27 and Val42 are partly responsible for enhancing the thermostability of BstHU. When considered together with previous results, it is revealed that Gly15, Ala27, Glu34, Lys38, and Val42 are essential for the thermostability of thermophilic protein BstHU. Moreover, five thermostabilizing mutations were simultaneously introduced into BsuHU, which resulted in a quintuple mutant with a Tm value of 71.3 degreesC, which is higher than that of BstHU, and also resulted in insusceptibility to proteinase digestion.

Bacterial Proteins↗
PubMed1998

N-linked glycosylation of Drosophila rhodopsin occurs exclusively in the amino-terminal domain and functions in rhodopsin maturation.

Immature Drosophila rhodopsin is N-glycosylated, but undergoes complete deglycosylation during the process of protein maturation. In order to elucidate the site of glycosylation and its role in rhodopsin synthesis, we investigated the in vitro and in vivo synthesis of rhodopsin whose putative N-glycosylation sites (Asn-20 and Asn-196) were replaced by isoleucine. The results demonstrated that immature rhodopsin binds a single oligosaccharide chain exclusively at Asn-20 in the N-terminal extracellular domain. Furthermore, the results gave the first evidence directly indicating that deletion of the oligosaccharide chain markedly impedes rhodopsin maturation.

Amidohydrolases↗
PubMed1998

Enhanced invasion of Tyzzer's organism into cultured mouse hepatocytes by cytochalasin D.

The effects of cytoskeleton inhibitors on the invasion of Tyzzer's organism, an obligate intracellular bacterium, into cultured mouse hepatocytes were examined by double immunofluorescence observation and plaque assay. The two techniques gave comparable results. Invasion of bacteria was significantly enhanced by cytochalasin D, a microfilament disrupting drug, and markedly suppressed by vinblastine, a microtubule inhibitor. Another microtubule inhibitor, colchicine, did not show any substantial effect. However, the cytoskeletal system of cultured mouse hepatocytes was sensitive to these three drugs, as judged by inhibition of FITC-dextran uptake. These results suggest that Tyzzer's organisms invade host cells by a unique mechanism that is suppressed by the normal functions of host cell microfilaments.

Animals↗
PubMed1998

Regeneration of ultraviolet pigments of vertebrates.

We report here the regeneration of the visual pigments of mouse, rat, goldfish and pigeon, which have wavelengths of maximal absorption at 359 nm, 358 nm, 359 nm, and 393 nm, respectively. The construction and functional assays of the ultraviolet or near-ultraviolet pigments from a wide range of vertebrate species will allow us to study the molecular bases of ultraviolet vision for the first time.

Amino Acid Sequence↗
PubMed1998

Determining the breast-feeding interruption schedule after administration of 123I-iodide.

Radioactivity after administration of 123I-sodium iodide was measured in breast milk samples obtained from a patient with postpartum thyroiditis. The breast milk was collected over 93 h during the infant's regular feeding times. The radioactivity in the breast milk was calculated with a 123I capsule of the same lot number as the standard source. 123I was excreted exponentially with an effective half-life of 5.5 h; 2.5% of the total radioactivity administered was excreted in the breast milk over the 93 h, 95% of which was excreted within the first 24 h, and 98.2% within 36 h. The first milk sample collected at 7 h after administration of the radiopharmaceutical contained 48.5% of the total radioactivity excreted. We estimated the potential absorption of radioactivity to an infant's thyroid in uninterrupted breast-feeding to be 30.3 mGy. With a 24-hour interruption, the absorbed radioactivity would be 1.25 mGy; with a 36-hour interruption, it would be 0.24 mGy. According to our calculations, breast feeding should be curtailed for 36 h to reduce the infant's exposure to 123I radioactivity. By using a correction factor based on maximum radioactivity from another 123I capsule of the same lot, we were able to ascertain the appropriate protocol for our patient and establish a measurement method that can be applied in similar clinical situations.

Adult↗
PubMed1998

Microorganism inactivation using high-pressure generation in sealed vessels under sub-zero temperature.

In order to test the possibility of utilizing high pressure in bioscience and biotechnology, a simple method for high-pressure generation and its use for microbial inactivation have been studied. When a pressure vessel was filled with water, sealed tightly and cooled to sub-zero temperatures, high pressure was generated in the vessel. The pressure generation was 60 MPa at -5 degrees C, 103 MPa at -10 degrees C, and 140 MPa at -15 degrees C, -20 degrees C, and -22 degrees C. The high pressure generated inactivated microorganisms effectively: yeasts (Saccharomyces cerevisiae and Zygosaccharomyces rouxii), bacteria (Lactobacillus brevis and Eschericia coli), and fungi (Aspergillus niger and Aspergillus oryzae) were completely inactivated when stored in sealed vessels -20 degrees C for 24 h. However, Staphylococcus aureus was only partly inactivated under the same conditions. This method opens up a new application of high pressure for storing, transporting, and sterilizing of foods and biological materials.

Bacteria↗
PubMed1998

Intrameatal tumours presenting as a hearing disturbance: case reports of meningioma and lymphoma.

This paper presents two patients with chronic progressive hearing disturbance. Each patients had an intrameatal tumour, part of which extended to the cerebellopontine (CP) angle. In both cases, the patients were initially diagnosed with an acoustic neurinoma. A 63-year-old male experienced a hearing disturbance in the left ear for 1.5 years prior to visiting our hospital. Magnetic resonance (MR) imaging revealed a mass which was surgically resected. The tumour originated from the intrameatal dura mater. Histologically, the tumour was a meningioma. Similarly, a 53-year-old male presented with systemic lymphoma diagnosed 10 months earlier, and a hearing disturbance in the right ear that began 3 months prior to visiting our hospital. MR imaging prior to chemotherapy revealed a mass which extended to the CP angle. Part of the tumour in the CP angle disappeared after chemotherapy, suggesting a secondary lymphoma. Another tumour appeared later in Meckel's cave on the left side; however, it decreased in size following repeated chemotherapy. The present results indicate that differential diagnosis of intrameatal tumours and acoustic neurinomas may be difficult due to the small tumour size. Recent progress in neuroradiology may allow distinction of intrameatal tumours as a separate tumour classification. Our second patient is the sixth reported case of a CP angle lymphoma in the literature.

Diagnosis, Differential↗
PubMed1998

Effect of protein kinase C inhibitors on cardioprotection by ischemic preconditioning depends on the number of preconditioning episodes.

OBJECTIVES: This study examined the possibility that the role of PKC in [corrected] PC, and thus the response to PFC inhibitors, may differ depending on how many ischemic episodes are employed to precondition the heart. METHODS: In the first series of experiments, myocardial infarct was induced by 30 min of coronary occlusion and 3 h of reperfusion in the rabbit. Infarct size was determined by tetrazolium staining and expressed as a percentage of area at risk (%IS/AR). Prior to the 30-min ischemia, rabbits were subjected to no PC, single PC (i.e., PC with an episode of 5 min ischemia/5 min reperfusion), and repetitive PC (2 cycles of 5 min ischemia/5 min reperfusion) with or without one of three treatments: polymyxin B (PolyB), staurosporine (Stauro), and 8-sulfophenylthephylline (SPT). In the second series of experiments, the rabbits received 5 min of coronary occlusion after repetitive PC with or without PolyB or Stauro treatment. Then, myocardial tissue in the ischemic region was sampled for assay of PKC activity. Untreated rabbits served as controls. RESULTS: Single and repetitive PC limited %IS/AR to the same extent (%IS/AR = 9.8 +/- 1.9 and 10.4 +/- 2.3, both p < 0.05, vs. the control value of 44.5 +/- 3.4), and single PC was blocked by PolyB (%IS/AR = 43.9 +/- 2.7) and Stauro (%IS/AR = 31.5 +/- 3.2). Although the protocol of PolyB injection maintained the plasma PolyB level during sustained ischemia well above its Ki for PKC, this agent and also Stauro failed to abolish the protection by repetitive PC (%IS/AR = 21.6 +/- 3.0 and 11.4 +/- 4.3, respectively). SPT, an adenosine receptor antagonist, not only blocked single PC (%IS/AR = 44.4 +/- 4.4) but also attenuated protection by repetitive PC (%IS/AR = 28.3 +/- 3.6). Infarct sizes in non-preconditioned hearts were not modified by PolyB, Stauro, or SPT. The ratio of membrane fraction PKC activity to cytosolic fraction PKC activity was elevated by repetitive PC plus 5 min ischemia, and this change in PKC was inhibited in hearts given PolyB and Stauro. CONCLUSIONS: In contrast to single PC, repetitive PC protects the heart against infarction even when PolyB and Stauro are administered to inhibit PKC during ischemic insult. This difference may be attributable to a PKC-independent mechanism, in which the adenosine receptor may be partly involved.

Animals↗
PubMed1998

Functional characterization of visual and nonvisual pigments of American chameleon (Anolis carolinensis).

Using only 11-cis 3, 4-dehydroretinal as a chromophore in the pure-cone retina, American chameleon (Anolis carolinensis) detects a wide range of color from ultraviolet (UV) to infrared. We previously characterized its visual opsin genes sws1Ac, sws2Ac, rh1Ac, rh2Ac, and LwsAc that encode SWS1Ac, SWS2Ac, RH1Ac, RH2Ac, and LWSAc opsins, respectively, and the pineal gland-specific opsin (PAc) gene. Here we present the light absorption profiles of the visual pigments obtained by expressing these opsins and reconstituting them with 11-cis retinal using the COS1 cell cDNA expression system. The purified SWS1Ac, SWS2Ac, RH1Ac, RH2Ac, LWSAc, and PAc pigments have the wavelengths of maximal absorption at 358, 437, 491, 495, 560, and 482 nm, respectively. SWS1Ac is the first vertebrate UV opsin whose spectral sensitivity has been directly evaluated. RH1 pigments, orthologous to the rod pigments of other vertebrates, are sensitive to hydroxylamine in the dark, exhibiting a cone pigment-like characteristic, probably reflecting their adaptation to the pure cone retina. Interestingly, the blue-sensitive SWS2Ac pigment shows an exceptionally low level of sensitivity to hydroxylamine, possessing a rod pigment-like characteristic.

Animals↗
PubMed1998

Pregnancy among long-term survivors of acute leukemia. A second nationwide survey.

A second nationwide survey was conducted to determine the outcome of pregnancy in long-term survivors of acute leukemia and to clarify the influence of treatment on the offspring of long-term survivors. In July 1996, 336 survey responses were received from the 498 Japanese institutions surveyed. A total of 89 cases (39 spouses of male patients and 50 female patients) who had babies during their first remission were analyzed, including 43 patients from the first survey in 1991. Median age at the birth of first baby was 30.7 years for male patients and 28.6 years for female patients. A total of 109 of the 117 pregnancies resulted in live births and eight resulted in abortions. A total of 58 cases had single children and 23 cases had two or more, generally from separate pregnancies, but including two pairs of twins. The infant was male in 59 cases, female in 37 and gender was not reported in 13 cases. Ages of children ranged from 2 months to 20 years at the time of this study and all children were in good health. There were two minor anomalies, both of which were surgically corrected. Of the 81 parents bearing live infants, 75 remained in complete remission. Five fathers died (four of relapse and one of another disease). In conclusion, there was no apparent increase in pregnancy complications or congenital anomalies in the children of long-term survivors with acute leukemia.

Acute Disease↗
PubMed1998

Combination chemotherapy in a patient with severe multiple systemic autoimmune disease.

We describe the occurrence of autoimmune haemolytic anaemia (AIHA) in a patient who had had both idiopathic thrombocytopenic purpura (ITP) and bullous pemphigoid (BP) for about 10 years. All of these diseases worsened rapidly, and the patient's clinical condition became critical after an episode of acute pneumonia. His AIHA, ITP and BP were responsive to combination chemotherapy consisting of cyclophosphamide, vincristine and prednisolone (CVP therapy).

Anemia, Hemolytic, Autoimmune↗
PubMed1998

Differential expression of genes involved in the biosynthesis and perception of ethylene during ripening of passion fruit (Passiflora edulis Sims).

An increase in the enzyme activity of 1-aminocyclopropane-1-carboxylic acid (ACC) synthase and ACC oxidase induces the evolution of ethylene during the ripening of passion fruit. A much higher level of ethylene is produced in arils than in seeds or peels during ripening. The pattern of expression of two ACC synthase genes (PE-ACS1 and PE-ACS2), one ACC oxidase gene (PE-ACO1), and two ethylene receptor genes (PE-ETR1 and PE-ERS1) revealed that the expression of these genes is differentially regulated. Expression of PE-ACS1 and PE-ACO1 was enhanced during ripening and after ethylene treatment. However, prominent expression of PE-ACS1 was delayed compared to that of PE-ACO1. Much larger quantities of PE-ACS1 mRNA and PE-ACO1 mRNA were seen in arils than in seeds; this corresponds well with an increase in the amount of ethylene produced by the plant tissue itself. The level of PE-ACS2 mRNA was detectable in arils of the preclimacteric fruit, although it decreased during ripening. These results suggest that expression of PE-ACS1 and PE-ACO1 is required to increase the activity of ethylene biosynthetic enzymes during ripening. The level of expression of PE-ETR1 and PE-ERS1 did not significantly change over the course of ripening; however, the mRNA levels of PE-ETR1 and PE-ERS1 were much higher in arils than in seeds.

Amino Acid Oxidoreductases↗
PubMed1998

Lack of selectin-dependent adhesion in prostate cancer cells expressing sialyl Le(x).

BACKGROUND: Recently, it has been reported that upregulation of the oligosaccharide sialyl Le(x) (SLe[x]) in prostate cancer is associated with hormone-resistant, aggressive disease. However, it is not clear that SLe(x) expressed on prostate cancer cells has a biological function related to metastatic potential. METHODS: The expression levels of SLe(x), sialyl Le(a) (SLe[a]), disialosyl galactosylgloboside (DSGG), monosialosyl galactosylgloboside (MSGG) and variousfucosyltransferases in 3 prostate cancer cell lines were determined. The function of SLe(x) expressed on prostate cancer cell lines was determined by a selectin-dependent adhesion assay. RESULTS: No prostate cancer cell lines expressed SLe(a), DSGG, or MSGG, but all prostate cancer cells moderately expressed SLe(x). Fucosyltransferase expression did not correlate with the expression of SLe(x), and all prostate cancer cells failed to bind immobilized selectin. CONCLUSION: The expression of SLe(x) on these prostate cancer cells does not correlate with selectin-dependent adhesion.

Cell Adhesion↗
PubMed1998

Ischemic preconditioning translocates PKC-delta and -epsilon, which mediate functional protection in isolated rat heart.

Protein kinase C (PKC) plays an important role in mediating ischemic preconditioning (PC). However, the relationship between PKC isoforms and PC is still uncertain. We analyzed subcellular localization of PKC isoforms by Western blot analysis in isolated rat heart and demonstrate that PKC-alpha, -delta, and -epsilon were translocated to the membrane fraction associated with the improvement of cardiac function. Translocation of PKC-delta and -epsilon persisted after a 30-min period following PC, but the translocation of PKC-alpha was transient. Under low Ca2+ perfusion (0.2 mmol/l), PC improved the cardiac function associated with the translocation of PKC-delta. Chelerythrine (1.0 micromol/l) suppressed the translocation of all PKC isoforms associated with the loss of improvement of the cardiac function. On the other hand, bisindolylmaleimide (0.1 micromol/l) did not inhibit the improvement of cardiac function induced by PC, which was associated with the translocation of PKC-epsilon. These results indicate that the effect of PC on cardiac function is mediated by the translocation of either PKC-delta or -epsilon independently in rat hearts.

Alkaloids↗
PubMed1998

Enhanced responses of the chorda tympani nerve to nonsugar sweeteners in the diabetic db/db mouse.

Genetically diabetic db/db mice show greater neural and behavioral responses to sugars than lean control mice. The present study examined chorda tympani responses of db/db mice to nonsugar sweeteners and their inhibition by a sweet response inhibitor, gurmarin. The results showed that responses to sucrose, saccharin, glycine, L-alanine, and D-tryptophan, but not to D-phenylalanine, were approximately 1.5 times greater in db/db mice than in control mice. Treatment of the tongue with gurmarin suppressed responses to these sweeteners in db/db and control mice, but the extent of suppression was considerably smaller in db/db mice. The magnitudes of gurmarin-sensitive components of the response to sweeteners in db/db mice were not significantly different from those in control mice, whereas the magnitudes of gurmarin-insensitive components in db/db mice were about twice as large as those in control mice. These results suggest that the enhancement of chorda tympani responses in db/db mice to sucrose and other nonsugar sweeteners may occur through gurmarin-insensitive membrane components.

Animals↗