Biomedical subjects

H Yano

Publications and source records attributed to H Yano.

At least 163 records · Page 9Linked to original sources

PubMed1999

[A case of right ventricular rupture due to blunt trauma].

A 33-year-old male was involved in a single motor vehicle accident and was referred to our hospital 135 minutes after injury. He had a sign of cardiac tamponade and immediately pericardial window was performed at the emergency department, but hypotension went worse. We transferred him to the operating room, and a median sternotomy could be done after cardiopulmonary resuscitation. There was a 4 cm tear in the right ventricular outlet and that was repaired primarily. Cardiac rupture due to blunt trauma is highly lethal, and prompt diagnosis is necessary for a favorable outcome. A high index of suspicion, avoidance of unnecessary diagnostic studies, and immediate surgical intervention are critical for successful management.

Accidents, Traffic↗

PubMed1999

[Predictive evaluation and efficient management of medical examinations using Mahalanobis Taguchi System Method].

UNLABELLED: The Mahalanobis-Taguchi System (MTS), an evaluative technique used in quality engineering, was utilized in a system analysis of medical examinations to determine practicability, to differentiate cost reduction benefits of specific components for increasing efficiency, and to determine possibility of utility on forecasting of future health condition of individuals. METHODS: 1. Medical examination date over a two year period were utilized to differentiate subject into two groups: Group A--Healthy or normal; and Group C--Patient group requiring treatment or currently undergoing treatment. The Mahalanobis distance for Group C from the Mahalanobis space of Group A was calculated for each subject to determine differentiability. 2. Utilizing the MTS method specific components of the examination system were selected and analyzed for effectiveness in diagnosis and screening to enhance efficiency of the examination. 3. Group A subjects (determined from the two year data), were analyzed using the data at the end of 1 year to develop the Mahalanobis space and the Mahalanobis distance at the 2nd year point was calculated and analyzed. RESULTS: 1. Subjects who were classified as group A at both 1st and 2nd year points numbered 159. With a cutoff point of 2.0 for Mahalanobis distance 98.1% of the healthy subjects (Group A) were classified as belonging to the healthy group, and 91.9% of C group as belonging to the patient group. 2. Blood pressure, GOT, GPT, gamma-GTP, T Chol, TG, UA, Cr, BS, HbA1c, Hb, and MCH were found to be effective components in the examination. Based on this result the items included in the examination can be reduced by approximately 60%. 3. With cutoff value of 1.5, the results of 90% of subjects 1 year later could be predicted. The prediction that 15% of Group C subjects would improve to join Group A could be made. Overall, the results 1 year later could be predicted at a level of 90% accuracy. CONCLUSION: These results suggest that the Mahalanobis-Taguchi System technique can accurately assess medical examination quality and can also be used, with reasonable accuracy, to predict the condition of individuals one year later. Therefore, the MTS can be used to help determine which patients should be receiving the examination 1 year later. In addition, components of the examination can be assessed using the MTS for benefits and costs to determine levels of essentiality of components. As a result, it can be used an effective tool for development and improvements in the examination system. With further development in the technique, it may become possible for use as a tool in disease diagnosis and treatment.

Cost-Benefit Analysis↗

PubMed1999

Formaldehyde treatment suppresses ruminal degradation of phytate in soyabean meal and rapeseed meal.

Most of the P in oilseed meal is in the form of phytate P, and phytate forms complexes with protein. Phytate P has been considered to be absorbed easily in ruminants because of phytate degradation in the rumen. Treatment of oilseed meals with formaldehyde improves the nutritional value of protein through suppressing its ruminal degradation. The present experiment was conducted to study the effects of formaldehyde treatment on phytate degradation in the rumen. The ruminal degradation of phytate in formaldehyde-treated soyabean meal or rapeseed meal was determined by a nylon-bag technique in sheep. Soyabean meal and rapeseed meal were treated with formaldehyde at levels of 3, 5 or 10 g/kg. Treatment with formaldehyde suppressed phytate and protein degradation in both the oilseed meals. Compared with the regular soyabean meal, the regular rapeseed meal showed lower degradability of phytate in the rumen. These results suggest that treatment with formaldehyde suppresses ruminal degradation of phytate in oilseed meal. Thus, the absorption of P from oilseed meal is probably decreased by this treatment in ruminants.

Analysis of Variance↗

PubMed1999

[Antibacterial activity of beta-lactam antibiotics against extended-spectrum beta-lactamase producing bacteria].

MICs of various beta-lactam antibiotics by themselves and in combination with beta-lactamase inhibitor (clavulanic acid) against extended spectrum beta-lactamase (ESBL) producing strains of Escherichia coli and Klebsiella pneumoniae which were isolated from clinical materials were investigated. Furthermore, based on the results obtained, a procedure to detect ESBL producing strains was proposed. The MICs of beta-lactam antibiotics against beta-lactamase producing strains were investigated. At first, beta-lactamase was investigated by the drug sensitivity pattern (MIC) to beta-lactam antibiotics and by the substrate profiles of beta-lactamase extracted from the transconjugant of E. coli K-12 strains. After that, we classified the beta-lactamase producing gene by PCR method. Furthermore, a proposal was made for an antibiotic to be used in the confirmation of mixed type beta-lactamase. The data obtained by the above investigations were compiled and used to determine the limit concentration of each beta-lactam against beta-lactamase producing strains including ESBL. By using beta-lactam antibiotics at the following concentrations, it is considered possible to classify beta-lactamase; ampicillin (64 micrograms/ml), ampicillin/clavulanic acid (32/5 micrograms/ml), piperacillin (64 micrograms/ml), cefotaxime (1 microgram/ml), cefpodoxime (2 micrograms/ml), ceftazidime (1 microgram/ml), cefmetazole (4 micrograms/ml), cefminox (2 micrograms/ml), cefepime (0.5 microgram/ml), aztreonam (1 microgram/ml) and imipeneme (1 microgram/ml). This method may be used as a reference in investigating the prevalence of beta-lactam resistant isolates by ESBL producing E. coli and K. pneumoniae.

Anti-Bacterial Agents↗

PubMed1999

Effects of long-term bed rest on H-reflex and motor evoked potential in lower leg muscles during standing.

Maximal H-reflex amplitude (Hmax) compared with maximal M-response (Mmax) has been generally used to assess the efficacy of the monosynaptic transmission from Ia afferents to alpha motoneurons in spinal cord. In previous studies, it has been demonstrated that H-reflex in soleus muscle (SOL) is inhibited during free standing due to an increase in presynaptic inhibition of the Ia afferent terminals to SOL motoneurones (Katz et al. 1988, Koceja et al. 1993). Transcranial magnetic stimulation (TMS) of human motor cortex excites the corticospinal system monosynapticaly connecting to spinal alpha motoneurones. However, it is not clear whether or not the motor evoked potentials (MEPs) in SOL and tibialis anterior (TA) muscles induced by TMS are modulated during standing (Ackermann et al. 1991, Lavoie et al. 1995). Considering that postural control functions change with exposure to weightlessness, we supposed that the excitability of SOL and TA spinal motoneurons from Ia afferents and/or corticospinal tracts during free standing would change after long-term bed rest (BR). The aim of this study was to investigate the effect of BR on H-reflex and MEP in SOL and TA during free standing.

Adult↗

PubMed1999

Gravity-dependent modulation of Ia afferent in human.

Recent work has shown that the H-reflex excitability of the human soleus motoneurones is modulated in reduced gravity and accompanied by a corresponding change in electromyographic (EMG) activity during space flight mission or different gravitational load. Spinal reflexes are often viewed as stereotyped motor patterns with limited scope for modification. However, recent evidence suggests that even short-latency, largely monosynaptic reflexes show a high degree of modulation during simple human motor activities such as walking and standing, and that the pattern of modulation can be specifically altered for the different functional requirements of each activity. Capady and Stein have demonstrated that H-reflex amplitude of the soleus increases progressively during the stance phase and reaches its peak amplitude late in the stance phase during walking. However, during running, the H-reflex is found to be significantly smaller than during walking, suggestion a modified spinal reflex gain for the different functional requirements of the motor behaviors. It is well documented that gravitational loads on the human body, spinal cords are much higher during standing in the water than standing in land. Little is known about the occurrence and influence of neural modulation in spinal cord during different gravitational load, which was not induced by posture but by voluntary background activity. The purpose of the present study was consequently to investigate how to effect is controlled H-reflex modulated during reduced gravity standing in a water in normal subjects.

Adult↗

PubMed1998

Transport of fragmented DNA in apical dendrites of gerbil CA1 pyramidal neurons following transient forebrain ischemia.

Transport of fragmented DNA in apical dendrites of the CA1 pyramidal neurons of gerbil hippocampus is observed in the apoptotic process following transient forebrain ischemia. The time-course of specific DNA fragmentation was examined after the ischemic insult by in situ nick-end-labeling method and fluorescence detection technique by DAPI. Although the role of the fragmented DNA movement is unclear, the transport mechanism of fragmented DNA is still active in the late phase of apoptotic process.

Animals↗

PubMed1998

Mutational analysis of the PTEN gene in head and neck squamous cell carcinoma.

Loss of heterozygosity (LOH) at chromosome band 10q23 occurs frequently in a wide variety of human tumors. A recently identified candidate tumor suppressor gene, PTEN located on 10q23, is mutated in multiple advanced cancers. To explore whether PTEN is associated with human squamous cell carcinoma of the head and neck (SCCHN), DNAs from both normal muscle and tumor tissue in 19 SCCHN were used for detecting LOH at chromosome 10q23 and mutational analysis of PTEN by direct polymerase chain reaction (PCR)-DNA sequencing. LOH at 10q23 was identified in 6/15 SCCHN. Mutation of PTEN was identified in 3/19 SCCHN. Of these 3 patients, 2 had stage IV disease; the third patient, with recurrent, metastatic and stage III disease, showed a 36 bp germline heterozygous deletion within intron 7. Furthermore, a missense mutation at codon 501 (TCT --> TTT: Ser --> Phe) in exon 8 was also found in tumor from the same patient. Our results suggest that PTEN may play a role in the genesis of some SCCHNs.

Amino Acid Substitution↗

PubMed1998

Microglial cells prevent nitric oxide-induced neuronal apoptosis in vitro.

Apoptotic neuronal death is known to occur in the developing brain and in the mature brain of patients with ischemic and degenerative disorders. Although microglial cells are known to become activated in specific conditions, it has not been elucidated whether they enhance or prevent neuronal apoptosis. The present study was intended to observe how microglial cells are involved in neuronal death. When rat primary cortical neurons were incubated with a nitric oxide (NO) donor sodium nitroprusside (SNP; 300 microM) for 10 min, neuronal death occurred 12-16 hr later. The NO-induced neuronal death was inhibited by cycloheximide, and the SNP-treated neurons were characterized by nuclear fragmentation and intact cell membrane under electron microscopy. Agarose gel electrophoresis demonstrated DNA fragmentation of the SNP-treated neurons. Thus, the NO-induced neuronal death appeared to be apoptosis. When neurons were cocultured with rat primary microglial cells, the SNP treatment failed to induce the neuronal death. Because microglia-conditioned medium also prevented apoptotic neuronal death, microglial cells were considered to secrete antiapoptotic factors. The microglia-conditioned medium rescued neurons even when they were added to neuronal cultures after the SNP treatment, implying that the factors acted on neurons in a manner other than scavenging NO. Interleukin-3, interleukin-6, macrophage colony-stimulating factor, and basic fibroblast growth factor, which are known to be secreted by microglial cells, were not effective in preventing NO-induced neuronal death. Among microglia-derived substances, tumor necrosis factor alpha and plasminogen, which are heat-labile proteins, inhibited neuronal apoptosis. The neuroprotective action of the microglia-conditioned medium, however, still remained, even after it was heated. These findings suggest that microglial cells protect neurons against NO-induced lethal damage by secreting heat-labile and heat-stable neuroprotective factors in vitro.

Animals↗

PubMed1998

Alpha1-adrenoceptor stimulation enhances experimental gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The effect of prolonged administration of the norepinephrine-mimicking agent metaraminol, the alpha1-adrenergic agonist phenylephrine and the alpha2-adrenergic agonist clonidine on the incidence of gastric cancers induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), the ornithine decarboxylase activity of the gastric cancer and the labeling index of the gastric mucosa were investigated in Wistar rats. Rats received s.c. injections of metaraminol, phenylephrine or clonidine every other day after 20 weeks of oral treatment with MNNG. At week 52, administration of metaraminol and phenylephrine at the higher dose significantly increased the incidence of gastric cancers, the ornithine decarboxylase activity of the gastric cancers and the labeling index of the antral epithelial cells. Administration of phenylephrine at the lower dose and clonidine at both doses had no significant effect on the incidence of gastric cancers, the ornithine decarboxylase activity of the gastric cancers or the labeling index of the gastric mucosa. Our results suggest that adrenoreceptor stimulation enhances gastric carcinogenesis and that such enhancement is mediated through alpha1-adrenoceptors without alpha2-adrenoceptor involvement.

Adrenergic alpha-Agonists↗

PubMed1998

Relationship between magnitude of hypothermia during ischemia and preventive effect against post-ischemic DNA fragmentation in the gerbil hippocampus.

Protective effect of hypothermia against DNA fragmentation in hippocampal CA1 field after transient forebrain ischemia in gerbils was evaluated by changing the magnitude of hypothermia. Inhibition of DNA fragmentation was proportional to the magnitude of hypothermia. The result indicates that, in terms of susceptibility to ischemia, hippocampal CA1 neurons are sensitive to a relatively small decrement of temperature, with temperatures </=35 degreesC being critical for the prevention of apoptotic process following transient forebrain ischemia.

Animals↗

PubMed1998

Attenuation by methionine of monochloramine-enhanced gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

Helicobacter pylori appears to play a major role in the development of gastric cancer in humans. The mechanism behind the carcinogenic or co-carcinogenic effects of H. pylori has not been established. Ammonia, generated by urea from H. pylori, has been studied as a possible cause. However, the ammonia-monochloramine system has been shown to play a more important role in H. pylori-associated mucosal injury. Therefore, the effects of combined administration of monochloramine and methionine, singly or together, on the development of gastric cancers induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) were investigated in inbred Wistar rats. After receiving oral MNNG and regular chow pellet for 25 weeks, rats received regular chow pellets or chow pellets containing 20% ammonium acetate, and normal tap water or water containing 30 mM sodium hypochlorite, with or without a subcutaneous injection of methionine, until the end of the experiment (week 52). Treatment with both ammonium acetate and sodium hypochlorite, which produce monochloramine, significantly increased the incidence of gastric cancers in week 52, whereas the concomitant administration of methionine with ammonium acetate and sodium hypochlorite significantly attenuated such enhanced gastric carcinogenesis. Spectrophotometric examination revealed that methionine scavenged monochloramine. Our findings suggest that H. pylori-associated gastric carcinogenesis may be mediated by monochloramine.

Animals↗

PubMed1998

Effects of noradrenaline on the cell-surface glucose transporters in cultured brown adipocytes: novel mechanism for selective activation of GLUT1 glucose transporters.

Glucose transport into rat brown adipocytes has been shown to be stimulated directly by the sympathetic neurotransmitter, noradrenaline, without a significant increase in the protein content of either GLUT1 or GLUT4 glucose transporter in the plasma membrane [Shimizu, Kielar, Minokoshi and Shimazu (1996) Biochem. J. 314, 485-490]. In the present study, we labelled the exofacial glucose-binding sites of GLUT1 and GLUT4 with a membrane-impermeant photoaffinity reagent, 2-N-[4-(1-azitrifluoroethyl)benzoyl]-[2-3H]1,3-bis- (D-mannos-4-yloxy)-2-propylamine (ATB-[3H]BMPA), to determine which isoform is responsible for the noradrenaline-induced increase in glucose transport into intact brown adipocytes in culture. Insulin stimulated the rate of hexose transport by increasing ATB-[3H]BMPA-labelled cell-surface GLUT4. In contrast, the noradrenaline-induced increase in glucose transport was not accompanied by an increased ATB-[3H]BMPA labelling of GLUT4, nor with an increased amount of GLUT4 in the plasma membrane fraction as assessed by Western blotting, indicating that noradrenaline does not promote the translocation of GLUT4. However, noradrenaline induced an increase in photoaffinity labelling of cell-surface GLUT1 without an apparent increase in the immunoreactive GLUT1 protein in the plasma membrane. This is suggestive of an increased affinity of GLUT1 for the ligand. In fact, the Ki value of non-radioactive ATB-BMPA for 2-deoxy-D-glucose uptake was significantly decreased after treatment of the cells with noradrenaline. The increased photoaffinity labelling of GLUT1 and increased glucose transport caused by noradrenaline were inhibited by a cAMP antagonist, cAMP-S Rp-isomer. These results demonstrate that noradrenaline stimulates glucose transport in brown adipocytes by enhancing the functional activity of GLUT1 through a cAMP-dependent mechanism.

Adipose Tissue, Brown↗

PubMed1998

Inhibition by galanin of experimental carcinogenesis induced by azaserine in rat pancreas.

The effects of galanin on pancreatic carcinogenesis induced by azaserine and on the norepinephrine concentration in the pancreas were investigated in male Wistar rats. Rats were given weekly injections of 10 mg/kg body weight of azaserine for 25 weeks and 8 microg/kg body weight of galanin in depot form every other day for 62 weeks. Azaserine-induced pancreatic lesions were examined with hematoxylin and eosin and histochemical techniques. In week 62, quantitative histological examination showed that prolonged administration of galanin significantly reduced the number and size (as percent of parenchyma) of adenosine triphosphatase-positive pancreatic lesions, which are correlated closely with the ultimate development of pancreatic cancer. The number of pancreatic adenocarcinomas in rats treated with galanin was significantly less than in controls. Galanin also significantly decreased the bromodeoxyuridine-labeling index of azaserine-induced pancreatic lesions and the norepinephrine concentration in the pancreas. Our findings indicate that galanin inhibits pancreatic carcinogenesis and that such inhibition may be related to the suppression of sympathetic nervous system activity and subsequently to the inhibition of cell proliferation in neoplastic lesions of the pancreas.

Animals↗

PubMed1998

Promotion by the alpha-adrenoceptor agonist phenylephrine, but not by the beta-adrenoceptor agonist isoproterenol, of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The effects of prolonged administration of the alpha-adrenoceptor agonist phenylephrine and the beta-adrenoceptor agonist isoproterenol on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine and on the labeling index of gastric mucosa were compared in Wistar rats. Rats received subcutaneous injections of 3 or 6 mg/kg body weight of phenylephrine or 0.1 or 0.2 mg/kg body weight of isoproterenol every other day after 25 weeks of oral treatment with the carcinogen. Long-term administration of phenylephrine at a high dose, but not at a low dose, significantly increased the incidence of gastric cancers and the labeling index of antral epithelial cells at the end of the experiment in week 52. However, administration of isoproterenol at either dosage had no significant effect on the incidence of gastric cancers and the labeling index of antral epithelial cells. These findings indicate that increased activity of the sympathetic nervous system enhances gastric carcinogenesis through alpha-adrenoceptors.

Adrenergic alpha-Agonists↗

PubMed1998

Expression of vascular endothelial growth factor in human hepatocellular carcinoma.

Vascular endothelial growth factor (VEGF) is thought to take an important role in tumor angiogenesis. The present study examined VEGF expression immunohistochemically in hepatocellular carcinomas (HCCs) in various histological grades and sizes. In HCCs that were composed of cancerous tissues of single histological grade, VEGF expression was the highest in well-differentiated HCCs, followed by moderately differentiated HCCs, and then poorly differentiated HCCs. VEGF positivity gradually decreased with the increase in tumor size. In the nodules larger than 3.0 cm, 36.8% were VEGF-negative. In HCCs consisting of cancerous tissues of two different histological grades, the expression was less intensive in the higher-grade HCC component. VEGF was not expressed in sarcomatous areas, while VEGF was expressed in the surrounding HCC tissues. The expression was also remarkable in the noncancerous tissues in which inflammatory cell infiltration was apparent. VEGF expression was also examined in six HCC cell lines. In reverse-transcription polymerase chain reaction (RT-PCR) analysis, expressions of the two secretion types (VEGF121 and VEGF165) were the highest. Thus, VEGF protein in culture supernatant was measured by using enzyme-linked immunosorbent assay (ELISA) with or without inflammatory cytokines, i.e., interleukin (IL)-1beta, interferon (IFN)-alpha, IFN-gamma, and tumor necrosis factor (TNF)-alpha; and growth factors, i.e., epidermal growth factor (EGF), platelet-derived growth factor (PDGF)-BB, basic fibroblast growth factor (bFGF), and transforming growth factor (TGF)-alpha. As a result, secretion of VEGF from the cell lines was upregulated at various degrees. Based on these findings, VEGF expression in HCC tissues was thought to be related to the histological grade. The findings also indicate that various cytokines and growth factors could cooperatively act to enhance VEGF expressions in HCC.

Aged↗

PubMed1998

Thiazolidinedione induces the adipose differentiation of fibroblast-like cells resident within bovine skeletal muscle.

To investigate the role of peroxisome proliferator-activated receptor gamma (PPARgamma) in adipocyte formation within the skeletal muscle of beef cattle, fibroblast-like cells were isolated from the longissimus muscle of cattle and cultured with activators of murine PPARgammaA thiazolidinedione T-174, which is a specific ligand for PPARgamma, stimulated adipose differentiation (evaluated by counting differentiated adipocytes under microscopic observation) in a dose-dependent fashion. A peroxisome proliferator Wy14,643 which strongly activates the alpha isoform of murine PPAR also stimulated differentiation but its potency was weaker than that of T-174. Unexpectedly, 15-deoxy-Delta12,14-prostaglandin J2, which is believed to be an endogenous ligand for PPARgamma, could not induce adipose differentiation in doses which have been found to be effective on rodent cells. Immunoblotting analysis confirmed the significant expression of PPARgamma protein in fibroblast-like cell cultures prepared from bovine skeletal muscle. In conclusion, bovine skeletal muscle contains adipose precursor cells expressing functionally active PPARgamma.

Adipocytes↗

PubMed1998

Fermentation of soybean meal with Aspergillus usamii improves zinc availability in rats.

Soybean meal was fermented with Aspergillus usamii to improve zinc availability through the degradation of phytic acid. Rats fed a diet containing fermented soybean meal showed greater femoral zinc than did animals fed a diet containing regular soybean meal. Zinc solubility in the small intestine was higher in the rats fed fermented soybean meal than in the rats fed regular soybean meal. These results suggested that fermentation with Aspergillus usamii improved zinc availability in dietary soybean meal, which was induced by the increase of zinc solubility in the small intestine. Adding the same amount of phytate that was contained in the regular soybean meal-based diet did not affect the amount of zinc present in rats fed a fermented soybean meal-based diet with sodium phytate. Phytase activity was found in fermented soybean meal, and this activity may degrade added phytate in fermented soybean meal-based diet.

Animal Feed↗