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Biomedical subjects

Y Morimoto

Publications and source records attributed to Y Morimoto.

At least 163 records · Page 9Linked to original sources
PubMed1999

A low-resolution structure of rice dwarf virus determined by ab initio phasing.

Rice dwarf virus crystals belong to space group I222 with cell parameters a = 770 (2), b = 795 (5), c = 814 (5) A and alpha = beta = gamma = 90 degrees. The unit cell of the crystal contains two viruses at the origin and body-centred positions. Using data synthesized from a rice dwarf virus model crystal in the space group I222, the possibility of ab initio phasing was thoroughly examined. The centric nature of the initial phases was unexpectedly broken by extensive iteration of the non-crystallographic symmetry averaging. The structure of rice dwarf virus was then solved with ab initio phasing up to 20 A resolution. The triangulation number determined by the present study is T = 13, which is different from the triangulation number, T = 9, previously determined by electron microscopy [Uyeda & Shikata (1982). Ann. Phytopathol. Soc. Jpn, 48, 295-300].

Capsid↗
PubMed1999

Forearm heating band used in apheresis therapy that employs a positive-temperature coefficient polymer heater.

For standard apheresis therapy, blood is withdrawn from the ante-cubital vein of one arm and processed blood is returned to a vein of the opposite arm. For low-density lipoprotein apheresis or for the treatment of patients with Guillain-Barré syndrome, a sufficient quantity of blood is readily obtained by this method. In some patients with collagen diseases, however, it may be difficult to secure a reliable vein due to vasospasm or it may not be possible to obtain sufficient blood flow. We constructed a forearm heating band by employing a positive-temperature coefficient heater and evaluated the device to determine whether the application of heat to the forearm is effective in securing a sufficient quantity of blood in those patients with collagen disease (eight with systemic lupus erythematosus and one with multicentric Castleman's disease). Both forearms were heated by using this heating band, in addition to systemic warming with an electric blanket, starting 30 minutes before apheresis. The body surface temperature was sequentially monitored by employing a needle-type thermometer. The surface temperature of the heated area became constant at 37.6+/-0.3 degrees C within approximately 20 minutes (34.7+/-1.3 degrees C at the control site, P<0.001). It was found that this heating band makes it possible to obtain the quantity of blood that is necessary for apheresis and reduce the time required for the treatment. No adverse effects attributable to heating of the forearm were recognized.

Blood Component Removal↗
PubMed1999

Prilocaine induces apoptosis in osteoblastic cells.

PURPOSE: To determine whether prilocaine, a local anesthetic, induces apoptosis in osteoblastic cells. METHODS: After reaching subconfluence, human osteoblastic Saos-2 and MG63 cells and mouse osteoblastic MC3T3-E1 cells were exposed for 48 hr to varying concentrations of prilocaine up to 10 mM and the cytotoxicity of the cells was analyzed by phase-contrast microscopy and WST-1 assay. Saos-2 cells treated for 48 hr with 5 mM prilocaine were stained with Hoechst 33342 and nuclear fragmentation was examined under a fluorescence microscope. DNA was extracted from the cells treated with 5 mM prilocaine and DNA ladder formation (a hallmark of apoptosis) was analyzed by agarose gel electrophoresis. RESULT: Prilocaine induced cell death in Saos-2 cells in a dose- and time-dependent manner up to the concentration of 10 mM. Marked nuclear condensation and fragmentation of chromatin were observed in the prilocaine-treated cells. DNA ladder formation also was induced by prilocaine treatment. Prilocaine-induced DNA ladder formation was dose-dependent with maximal effect at a concentration of 5 mM and was time-dependent from 12 to 48 hr. DNA ladder formation was also induced by prilocaine treatment in human osteoblastic MG63 cells and mouse osteoblastic MC3T3-E1 cells. Cycloheximide prevented prilocaine-induced apoptosis in Saos-2 cells in a dose-dependent fashion up to 20 microM as determined by WST-1 assay and DNA ladder formation in agarose gel electrophoresis. CONCLUSION: Osteoblastic cells treated with prilocaine exhibit both morphological and biochemical features indicative of apoptosis. The apoptotic mechanisms involve transcriptional regulation of specific proteins or protein synthesis.

Anesthetics, Local↗
PubMed1999

Alterations of soluble L- and P-selectins during cardiac arrest and CPR.

OBJECTIVE: To investigate the relationship between cytokines and the inflammatory responses in patients with out-of-hospital cardiac arrest, we examined the changes of cytokines as well as alterations in the markers of neutrophil activation, platelet and endothelial activation, and endothelial injury. DESIGN: Prospective, cohort study. SETTING: General intensive care unit of a tertiary care center. PATIENTS AND PARTICIPANTS: 26 out-of-hospital cardiac arrest patients were classified into two groups: those who achieved return of spontaneous circulation (ROSC) (n = 10) and those with no ROSC (n = 16). Eight normal healthy volunteers served as control subjects. MEASUREMENTS AND RESULTS: Serial levels of soluble L-selectin (sL-selectin), soluble P-selectin (sP-selectin), neutrophil elastase, and soluble thrombomodulin were measured during and after cardiopulmonary resuscitation (CPR). Serial levels of tumor necrosis factor alpha (TNFalpha) and interleukin-1beta (IL-1beta) were also measured. We could not find any elevations in either cytokine during the study period. In both groups, sP-selectin levels were significantly higher than those in control subjects from the time of arrival at the emergency department to 24 h after admission. sL-selectin levels in the two groups were markedly lower compared to those in control subjects at all sampling points. In patients with ROSC, cardiac arrest and CPR led to an increase in the levels of neutrophil elastase and soluble thrombomodulin that peaked 6 h or 24 h after arrival at the emergency department. No statistical differences in the levels of the two selectins, neutrophil elastase, and soluble thrombomodulin between the two groups were found during CPR. CONCLUSIONS: Out-of-hospital cardiac arrest and CPR induces platelet, neutrophil, and endothelial activation and is associated with endothelial injury. Inflammatory cytokines may not have an important role in human whole-body ischemia-reperfusion injury.

Aged↗
PubMed1999

Inhibitors of protein synthesis and RNA synthesis protect against okadaic acid-induced apoptosis in human osteosarcoma cell line MG63 cells but not in Saos-2 cells.

In a previous study, we demonstrated that the protein phosphatase inhibitors, okadaic acid and calyculin A, induced apoptosis in human osteosarcoma cell lines, Saos-2 and MG63 cells. In the present study, to determine if new gene transcription and protein synthesis are required for okadaic acid-induced apoptosis in Saos-2 and MG63 cells, the cells were treated for 48h with varying concentrations of the inhibitors of protein or RNA synthesis, i.e., cycloheximide, actinomycin D, and puromycin, in the presence of a fixed dose of okadaic acid. All these reagents in different concentrations prevented the okadaic acid-induced apoptosis in MG63 cells in a dose-dependent fashion. The same concentrations of cycloheximide, actinomycin D, or puromycin alone did not induce any apoptotic features in MG63 cells. However, not all the aforementioned reagents affected okadaic acid-induced apoptosis in Saos-2 cells. Okadaic acid-induced and cycloheximide-prevented apoptosis was shown by phase-contrast microscopy, WST-1 assay, direct visualization of nuclear condensation and fragmentation of chromatin, and the characteristic DNA ladder formation on agarose gel electrophoresis. The present results indicate that the induction of new cell death genes and ongoing protein synthesis may have a role in okadaic acid-induced apoptosis in MG63 cells and that such proteins are not required in Saos-2 cells.

Apoptosis↗
PubMed1999

MUC1 mucin mRNA expression in stage I lung adenocarcinoma and its association with early recurrence.

BACKGROUND: MUC1 is a membrane-bound mucin with an extensively O-glycosylated core protein and is developmentally regulated and aberrantly expressed by carcinomas. A high level of MUC1 mucin expression and secretion is associated with high metastatic potential and a poor prognosis. We studied the expression of MUC1 messenger ribonucleic acid (mRNA) in stage I lung adenocarcinoma by reverse transcriptase-polymerase chain reaction and examined its correlation with early recurrence. METHODS: The expression of MUC1 mRNA, in surgical specimens from 33 patients with stage I lung adenocarcinoma was determined by reverse transcriptase-polymerase chain reaction. The MUC1 and beta-actin sequences were subsequently coamplified to analyze the semiquantitative determination by polymerase chain reaction. The ratio of MUC1 to beta-actin product was used for further analysis. RESULTS: An analysis of the disease-free survival (median follow-up, 33.4 months) revealed that a high expression of MUC1 was associated with early recurrence (p = 0.0191). Six of the 33 patients had recurrence within 2 years after operation. The recurrence sites suggested hematogenic metastasis. CONCLUSIONS: Our results indicate that MUC1 mRNA level may be useful as a marker of early recurrence in stage I lung adenocarcinoma.

Adenocarcinoma↗
PubMed1999

Binding affinity of sarpogrelate to 5-HT(2A) receptor ligand recognition sites in rat renal cortical and mesangial cells in culture.

We detected specific binding of 3H-ketanserin (0.6 nM) in rat renal cortical membrane preparations (4.70 +/- 0.57 fmol/mg protein) and mesangial cells (7.55 +/- 0.92 fmole/10(6) cells). Thus, the value in the renal cortical membrane corresponded to 15% of that in the cerebral cortical membranes (30.0 +/- 2.9 fmole/mg protein). The affinity of 3H-ketanserin binding displacement activities by sarpogrelate, a selective 5-HT2A receptor antagonist, in the renal cortical membrane (IC50; 0.448 +/- 0.061 microM) and mesangial cells (IC50; 0.656 +/- 0.187 microM) were almost 100-fold less than that in the cerebral cortical membrane (IC50; 4.62 +/- 1.02 nM). In the renal cortical membranes and mesangial cells, methysergide displaced a tiny fraction of 3H-ketanserin binding at concentrations up to 10 microM. These results did not explain the functional activity of 5-HT in the mesangial cells, and we conclude that specific 3H-ketanserin binding sites in the mesangial cells consisted of methysergide-resistant and non-serotonergic sites with low affinity for sarpogrelate.

DOM 2,5-Dimethoxy-4-Methylamphetamine↗
PubMed1999

A novel panoramic machine for photofluorography.

OBJECTIVE: To describe the main features of a prototype panoramic X-ray machine modified for photofluorography. METHODS: The prototype PTM 2001 (Asahi Roentgen, Kyoto, Japan) consists of a conventional panoramic machine with a modified X-ray generator and incorporating a 9-inch image intensifier and a photofluorographic camera. RESULTS: The photofluorographic panoramic radiograph is reduced in size by 60% compared with conventional images. Using 10 cm x 45.7 m photoradiographic film 250 panoramic images can be continuously obtained. Examination time is shorter since cassette changes are not necessary. The radiation dose-in-air, measured in front of the secondary collimator, is 174 muGy. CONCLUSIONS: The advantages of the photofluorographic panoramic radiography include cost economy, shorter examination time and lower radiation exposure.

Equipment Design↗
PubMed1999

Pilocarpine-induced cholinergic sweat secretion compared with emotional sweat secretion in atopic dermatitis.

We studied pilocarpine-induced cholinergic sweating, emotional sweating and sympathetic reflex sweating in atopic dermatitis (AD) patients. Secreted sweat was measured both with equipment that continuously records sweat rate and with a filter paper method that measures sweat weight absorbed. Comparison of the two methods revealed that the filter paper method underestimated the sweat secretion in AD patients. While AD patients showed no significant abnormalities in emotional sweating and sympathetic reflex sweating, the duration of pilocarpine-induced sweating was prolonged. The time from the maximal sweat rate until the sweat rate fell to half of the maximal rate was significantly longer in AD patients than in control subjects. In contrast, the time from the beginning of sweat secretion until the maximal sweat rate was not significantly different between AD patients and control subjects. There was no significant difference between AD patients and control subjects in sweat volume secreted in 20 min after pilocarpine iontophoresis. In AD patients, the total sweat volume secreted after pilocarpine iontophoresis was greater than in control subjects, although not significantly. These results suggest that the system of deactivation of pilocarpine-induced sweat secretion is impaired in AD patients whereas the activation system is not altered.

Adult↗
PubMed1999

Functional expression of Fas and Fas ligand on human intestinal intraepithelial lymphocytes.

Intestinal intraepithelial lymphocytes (IEL) constitute the first lymphoid compartment to encounter dietary antigens and intestinal pathogens. IEL are proposed to be involved in the defence against bacterial and viral invasion and to play an important role in mucosal immunity. Fas (CD95/APO-1) is a surface receptor that induces apoptotic cell death upon ligation with Fas ligand (FasL). The aim of this study was to examine the expression and function of Fas and FasL on freshly isolated normal human colonic IEL. The expression and function of Fas and FasL on IEL isolated from 40 normal colonic specimens were examined by flow cytometry, reverse transcriptase-polymerase chain reaction, immunohistochemistry, and DNA-release cytotoxicity assay. Virtually all CD3+ IEL (95.2 +/- 4.3%) expressed Fas and were sensitive to agonistic anti-Fas antibody, whereas only 56.6 +/- 8.4% of peripheral T lymphocytes expressed Fas and were resistant to the antibody. We also detected FasL mRNA and protein (40.1 +/- 4.2%) on IEL, and found that IEL exerted FasL-mediated cytotoxicity against Fas-expressing target cells. These findings suggest that human IEL are activated in situ but are tightly regulated by the constitutive expression of functional Fas and FasL to maintain homeostasis of the mucosal immune system.

Adult↗
PubMed1999

Detection of Escherichia coli O157:H7 from Musca domestica (Diptera: Muscidae) at a cattle farm in Japan.

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 was isolated for the first time from Musca domestica L. A total of 310 fly samples was collected from 4 different farms in Obihiro-City, Hokkaido, in the summer and autumn of 1997;5 samples carried E. coli serotype O157:H7. Using ELISA and Vero cell cytotoxicity assay, 3 isolates from 1 cattle farm produced both active Shiga-toxin type 1 (Stx1) and 2 (Stx2). These isolates also carried hemolysin and eaeA genes and harbored the 90-kb virulence plasmid of EHEC O157:H7. Based on plasmid profiles, antibiotic patterns, polymerase chain reaction (PCR)-based DNA finger printing analysis using random amplified polymorphic DNA, pulsed field gel electrophoresis analysis, and DNA sequences of stx1 and stx2, all 3 isolates from fly samples were identical. These results indicate that the house fly is capable of carrying the toxigenic EHEC O157:H7 involved in human disease.

Animals↗
PubMed1999

End-tidal carbon dioxide and resuscitation.

In this review, we attempted to summarize the effectiveness and the limitation of end-tidal carbon dioxide monitoring during cardiopulmonary resuscitation. End-tidal carbon dioxide can be an indicator of the real return of spontaneous circulation and can also be an indicator of the effectiveness of cardiac massage. We cannot, however, estimate the prognosis of cardiopulmonary resuscitation from the end-tidal carbon dioxide value. We concluded that cardiopulmonary resuscitation should never be abandoned for the sole reason that the end-tidal carbon dioxide value is low.

Journal Article↗
PubMed1999

Systemic activation of tissue-factor dependent coagulation pathway in evolving acute respiratory distress syndrome in patients with trauma and sepsis.

BACKGROUND: Extravascular coagulation and fibrin deposition coupled with perturbations of intravascular coagulation occurs in association with acute respiratory distress syndrome (ARDS). To evaluate the pathogenetic role of an extrinsic coagulation pathway in the intravascular coagulation of ARDS patients and to explore the time course of the changes of tissue factor levels, platelet counts, and disseminated intravascular coagulation (DIC), we performed a prospective cohort study. METHODS: The study subjects consisted of 113 patients: 27 patients with ARDS, 31 patients at risk for but not developing the syndrome, and 55 patients without ARDS. According to the underlying disease, the patients were further subdivided into two groups: patients with trauma (n = 76) and patients with sepsis (n = 37). Ten normal healthy volunteers served as control subjects. Plasma tissue factor antigen (tissue factor) levels and platelet counts were measured on the day of admission and on days 1 through 4 after admission. Simultaneously, the DIC scores were determined. RESULTS: The values of tissue factor in the patients with ARDS were significantly more elevated than those measured in the other two groups (p < 0.001) and control subjects (p < 0.001) on the day of admission. The values continued to be markedly high up to day 4 of admission. On the day of admission, the platelet counts in the ARDS patients showed significantly lower values (p < 0.05) than those in the other two groups. The incidence of DIC and the DIC scores in ARDS patients were significantly higher than those in the other two groups. The tissue factor levels (r(s) = 0.428, p < 0.0001) and DIC scores (r(s) = 0.357, p < 0.0002) correlated significantly with Lung Injury Score. When the patients were subdivided into two subgroups, i.e., trauma and sepsis, some differences of the tissue factor levels were noted between the two groups. CONCLUSION: We demonstrated that tissue-factor dependent coagulation pathway of plasma is extensively activated in patients with ARDS, followed by intravascular coagulation and platelet consumption. We further provide precise information on the time course of tissue factor levels and DIC in patients with ARDS and those at risk for developing this syndrome.

APACHE↗
PubMed1999

Structure determination of rubredoxin from Desulfovibrio vulgaris Miyazaki F in two crystal forms.

The structures of two crystal forms (form I, P3221, a = b = 43.7, c = 50.7 A; form II, P21, a = 27.3, b = 44.9, c = 51.2 A and beta = 90. 6 degrees ) of the rubredoxin from Desulfovibrio vulgaris Miyazaki F have been solved by the molecular-replacement method. Form I has been refined at a resolution of 2.0 A to an R value of 20.8% and includes 32 water molecules. Form II includes 86 water molecules and has been refined at 1.9 A resolution to an R value of 17.5%. In form II, there are three molecules in the asymmetric unit with the molecules related by a non-crystallographic 32 symmetry axis. In both crystal forms, it was found that only a few residues effectively participate in the formation of intermolecular contacts along both the crystallographic (form I) and the non-crystallographic (form II) 32 axes. The crystal structure of the form II crystal is compared with those of other rubredoxin molecules from anaerobic bacteria. From this comparison, a similarity in the core region, which is composed of aromatic residues and includes the active centre, has been revealed.

Amino Acid Sequence↗
PubMed1999

Crystallization and preliminary x-ray study of two crystal forms of Klebsiella oxytoca diol dehydratase-cyanocobalamin complex.

Two crystal forms of Klebsiella oxytoca diol dehydratase complexed with cyanocobalamin have been obtained and preliminary crystallographic experiments have been performed. The crystals belong to two different space groups, depending on the crystallization conditions. One crystal (form I) belongs to space group P212121 with unit-cell parameters a = 76.2, b = 122.3, c = 209. 6 A, and diffracts to 2.2 A resolution using an X-ray beam from a synchrotron radiation source. The other crystal (form II) belongs to space group P21 with unit-cell parameters a = 75.4, b = 132.7, c = 298.8 A, beta = 91.9 degrees, and diffracts to 3.0 A resolution. For the purpose of structure determination, a heavy-atom derivative search was carried out and some mercuric derivatives were found to be promising. Structure analysis by the multiple isomorphous replacement method is now under way.

Bacterial Proteins↗
PubMed1999

Crystallization and preliminary crystallographic studies of FMN-binding protein from Desulfovibrio vulgaris miyazaki F.

The flavin mononucleotide binding protein from Desulfovibrio vulgaris (Miyazaki F) was crystallized using the vapour-diffusion method. The crystal belongs to the monoclinic space group P21 with unit-cell parameters a = 37.2, b = 84.6, c = 41.1 A, beta = 94.1 degrees, contains two molecules per asymmetric unit and diffracts beyond 1.2 A resolution with a synchrotron radiation X-ray source.

Bacterial Proteins↗
PubMed1999

The protein phosphatase inhibitors, okadaic acid and calyculin A, induce apoptosis in human submandibular gland ductal cell line HSG cells.

OBJECTIVE: To investigate a possible relationship between protein phosphorylation or dephosphorylation status and apoptosis in salivary gland cells, we examined the effects of okadaic acid and calyculin A, the protein phosphatase inhibitors, on cultured human submandibular gland ductal cell line, HSG cells. METHODS: HSG cells at subconfluent stages were exposed to varying concentrations of okadaic acid or calyculin A. Apoptoses were analysed in HSG cells by phase-contrast microscopy, WST-1 cytotoxicity assay, Hoechst 33342 staining, and DNA ladder formation. RESULT: Both okadaic acid and calyculin A induced cell death in HSG cells in a dose-dependent fashion. Marked nuclear condensation and fragmentation of chromatin was observed in HSG cells. DNA ladder formation was also detected in HSG cells by treatment with okadaic acid or calyculin A. The induced DNA ladder formation was dose-dependent with maximal effect at concentrations of 50 nM okadaic acid and 2 nM calyculin A, respectively, and were time-dependent from 14 h to 48 h. To further determine if new gene transcription and protein synthesis regulate okadaic acid-induced apoptosis in HSG cells, the cells were treated with cycloheximide or actinomycin D in the presence of 20 nM okadaic acid. Neither inhibitor protected the cells against okadaic acid-induced apoptosis. CONCLUSION: Based on the known selectivity of okadaic acid and calyculin A, our results indicate that the pathway of the apoptosis in the cultured salivary gland cells is regulated by protein phosphatase type 1 or type 2A. Our results also suggest that new protein synthesis and/or mRNA expression are not involved in okadaic acid-induced apoptosis in HSG cells.

Apoptosis↗