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Biomedical subjects

S Miyazaki

Publications and source records attributed to S Miyazaki.

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

Paradoxical synergistic effects of tumour necrosis factor and interleukin 1 in murine gut-derived sepsis with Pseudomonas aeruginosa.

The authors evaluated the synergistic effect of tumour necrosis factor (TNF) and interleukin 1 (IL-1) in gut-derived sepsis in mice. After colonization of Pseudomonas aeruginosa strain D4 in the gastrointestinal tract, cyclophosphamide was administered to induce bacterial translocation of the P. aeruginosa and thereby to cause gut-derived sepsis. In this model, treatment either with 8 microg/kg of recombinant human TNF-alpha (rhTNF-alpha) or 2 microg/kg of recombinant human interleukin 1alpha (rhIL-1alpha) solely did not affect the mortality, whereas combined administration of the same doses of rhTNF-alpha and rhIL-1alpha significantly increased the mortality rate in comparison with saline-treated mice. Bacterial counts in liver and blood were significantly higher in rhTNF-alpha and rhIL-1alpha treated mice than in saline-treated mice. Endogenous TNF-alpha and IL-1beta productions were stimulated after combined treatment with rhTNF-alpha and rhIL-1alpha. On the contrary to these adverse effects, combined treatment with 500 microg/kg of rhTNF-alpha and 50 microg/kg of rhIL-1alpha on the day before the administration of cyclophosphamide significantly reduced the mortality from septic infection. We conclude that TNF and IL-1 synergistically affect the mortality of mice after gut-derived sepsis due to P. aeruginosa in mice and the timing of treatment with these cytokines causes both extremes in their effects.

Animals↗
PubMed1999

Biological functions of recombinant bovine interleukin 6 expressed in a baculovirus system.

The cDNA encoding bovine interleukin 6 (IL-6) was obtained from messenger RNA extracted from lipopolysaccharide-stimulated bovine Kupffer cells by the reverse transcription polymerase chain reaction (RT/PCR), and cloned into the baculovirus vector pVL 1392. Insect cells (Sf21AE derived from Spodoptera frugiperda) infected with the recombinant baculovirus secreted a large amount of 23.7 kD protein into the culture medium. This protein was capable of causing increased haptoglobin production and decreased albumin production in primary cultured bovine hepatocytes. The swine and human IL-6s were also able to decrease albumin production in bovine hepatocytes. This recombinant IL-6 did not stimulate the proliferation of 7TD1 cells (a murine IL-6-dependent cell line), whereas the recombinant swine IL-6 which was expressed in the same baculovirus system, and recombinant human IL-6 derived from Escherichia coli were each capable of stimulating proliferation of 7TD1 cells, respectively. This suggests a species restriction between bovine IL-6 and murine IL-6 dependent cell lines.

Acute-Phase Proteins↗
PubMed1999

Acute health problems among the people engaged in the cleanup of the Nakhodka oil spill.

To determine if the Nakhodka oil spill and subsequent cleanup efforts had any health effects on the residents along the oil-contaminated coast, we investigated the health status of Anto residents who resided nearest to the coast where the bow ran aground. Two hundred eighty-two men and women involved in the cleanup activities between January 7 and January 20 were interviewed and examined by public health nurses to determine whether they suffered physical symptoms after exposure to the oil spill. Urine examinations for hydrocarbon toxicological markers were performed on 97 residents. The average number of days worked on cleanup activities was 4.7 days for men and 4.3 for women. Seventeen percent of the subjects had worked on cleanup activities for more than 10 days. Protective equipment was used against direct exposure to oil during the cleanup jobs and consisted of gloves used by almost 100% of the subjects and masks used by 87.1% of women and by only 35.4% of men. Glasses were worn by less than 30% of the subjects. Many symptoms emerged after the beginning of cleanup activities. The principal symptoms included low back pain and leg pain, headache, and symptoms of eyes and throat. Among the subjects undergoing urine tests, only three people showed a higher level of hippuric acid, although they returned to normal in the second examination. Accordingly, the exposure to the oil and the subsequent cleanup efforts were suggested to inflict acute health problems on local residents.

Acute Disease↗
PubMed1999

Tissue- and environmental response-specific expression of 10 PP2C transcripts in Mesembryanthemum crystallinum.

Ten transcripts (Mpc1-10) homologous to protein phosphatases of the 2C family have been isolated from the halophyte Mesembryanthemum crystallinum (common ice plant). Transcripts range in size from 1.6 to 2.6 kb, and encode proteins whose catalytic domains are between 24% and 62% identical to that of the Arabidopsis PP2C, ABI1. Transcript expression is tissue specific. Two isoforms are present only in roots (Mpc1 and Mpc5), three in young leaves (Mpc6, 8 and 9), two in old leaves (Mpc6 and Mpc8), and two in post-flowering leaves (Mpc8 and Mpc9). Mpc2 is strongly expressed in roots and also in seeds, meristematic tissues and mature flowers. Mpc3 is specific for leaf meristems, and Mpc4 is found in root and leaf meristems. Mpc7 is restricted to meristematic tissues. Mpc10 is only present in mature flowers. Mpc2 (in roots and leaves), Mpc5 (in roots) and Mpc8 (weakly in leaves) are induced by salinity stress and drought conditions with different kinetics in different tissues, but other Mpcs are downregulated by stress. Cold stress (4 degrees C) leads to a decline in Mpc5 and Mp6, but low temperature provoked a long-term (days) increase in Mpc2 levels in leaves and a transient increase (less than 24 h) in roots. Four full-length transcripts have been obtained. In each case, after over-expression in E. coli, the isolated proteins exhibited (Mg2+-dependent, okadeic acid-insensitive) protein phosphatase activity, although activity against 32P-phosphocasein varied among different PP2Cs. Determination of tissue developmental and stress response specificity of PP2C will facilitate functional studies of signal-transducing enzymes in this halophytic organism.

Base Sequence↗
PubMed1999

Exercise-induced QRS prolongation in patients with mild coronary artery disease: computer analysis of the digitized multilead ECGs.

Although exercise-induced QRS prolongation has been reported as a possible marker for inducible ischemia, subtleness of the prolongation makes it unidentifiable from standard, chart-recorded electrocardiograms (ECGs). To overcome such a limitation, we measured the QRS width using high-resolution ECGs and examined the diagnostic value of the exercise-induced QRS prolongation in patients before and after percutaneous transluminal coronary angioplasty (PTCA). In 16 patients with single- (n = 12) or double-vessel disease (n = 4), treadmill exercise ECG tests were performed before and after PTCA, while continuously recording 8-lead ECGs at 500 Hz. The onset of the QRS complexes was defined by the earliest deflection, and the end was defined as the latest deflection among 8 leads with the use of algebraic sum of the absolute voltage and their time derivatives (dV/dt) from all 8 leads. We compared QRS complexes before and 1 minute after exercise. Before PTCA, exercise prolonged the QRS width in all but 3 patients (unchanged in 2, decreased in 1) (84 +/- 7 to 87 +/- 8 ms, P < .005). After PTCA, it decreased in 4, was unchanged in 5, and increased in 7 (83 +/- 7 to 83 +/- 6 ms, not significant). PTCA shortened postexercise QRS width in all but 3 (unchanged in 2, increased in 1: 83 +/- 6 to 87 +/- 8 ms, P < .001). High-resolution ECGs enabled us to measure subtle QRS prolongation induced by mild ischemia. Because the QRS prolongation and ST-segment changes would reflect different aspects of myocardial ischemia, incorporating this measure into ST segment criteria might significantly improve the diagnostic accuracy for coronary artery disease.

Adult↗
PubMed1999

Effects of nucleotides on learning and memory in a Morris water maze test in normal and basal forebrain-lesioned rats.

The effects of nucleotides on learning and memory were studied in normal and basal forebrain-lesioned rats using a Morris water maze test. Chronic oral administration of a nucleotide mixture (500 mg/kg), containing an equal weight of the disodium salts of adenosine 5'-monophosphate, guanosine 5'-monophosphate, inosine 5'-monophosphate, cytidine 5'-monophosphate, and uridine 5'-monophosphate facilitated learning acquisition in normal rats. In basal forebrain-lesioned rats, administration of the nucleotide mixture showed a tendency to improve learning acquisition and memory retrieval. In the biochemical studies, no significant changes were observed in brain choline and acetylcholine levels by treatment with the nucleotide mixture at the doses tested in both normal and basal forebrain-lesioned rats. The nucleotides did not affect the monoaminergic systems in normal rats, but did cause some changes in these systems in basal forebrain-lesioned rats. The present studies indicate that nucleotides ameliorate learning and memory processes in normal rats, but not in basal forebrain-lesioned rats, and they also modulate the activity of the central monoaminergic systems under certain conditions.

Acetylcholine↗
PubMed1999

Cerebrospinal fluid cytokine levels and dexamethasone therapy in bacterial meningitis.

OBJECTIVES: cerebrospinal fluid (CSF) levels of interleukin (IL)-1 beta and tumor necrosis factor (TNF) alpha were measured to assess the effect and application of dexamethasone (Dex) therapy for bacterial meningitis. METHODS: associations between clinical findings and CSF parameters were first investigated, and prognosis was compared between 25 patients with Dex and 12 without Dex therapy. RESULTS: patients with the presence of disturbed consciousness showed higher CSF levels of TNF alpha (mean: 3015 pg/ml) or protein (mean: 215 mg/dl) than those without it (both, P < 0.O5). Simultaneous increase of TNF alpha (> 1000 pg/ml) and protein (> 100 g/dl) was observed in 80%, of patients with profoundly disturbed consciousness. Patients with Dex therapy presented higher TNF alpha/protein levels at diagnosis than those without Dex therapy (P < 0.05). Despite worse conditions at diagnosis, only one of 14 Dex-treated patients whose initial CSF TNF alpha levels exceeded 1000 pg/ml developed deafness. On the other hand, two of four patients without Dex therapy who had the same TNF alpha level suffered from psychomotor retardation. The differences in the frequency of sequelae between those with and without Dex therapy were significant in patients showing high TNF alpha level (P < O.05), but not in those showing high CSF levels of IL-1 beta or protein. The logistic regression analysis indicated that high CSF protein level (P < O.0001), or no Dex therapy (P=0.0001) was the independent risk factor for sequelae. CONCLUSIONS: although the study number was small, our observations suggested that CSF TNF alpha/protein levels reflected the neurologic severity, and implied that early Dex therapy might be beneficial for patients with prominently high TNF alpha levels.

Adolescent↗
PubMed1999

The laminin-derived peptide YIGSR (Tyr-Ile-Gly-Ser-Arg) inhibits human pre-B leukaemic cell growth and dissemination to organs in SCID mice.

The YIGSR (Tyr-Ile-Gly-Ser-Arg) laminin beta1 chain sequence has an inhibitory effect on tumour growth and the metastasis of melanoma and fibrosarcoma cells. In the present study, we investigated whether the multimeric YIGSR peptide (Ac-Y16) has an antiproliferative effect and/or prevents the metastasis of human pre-B acute lymphoblastic leukaemia cells (NALM6) in severe combined immune deficient (SCID) mice. In in vitro studies, Ac-Y16 significantly inhibited leukaemic cell colony formation and the invasion of NALM6 cells in a Matrigel-based assay. The tumour growth and leukaemic infiltration in peripheral tissues were also analysed in SCID mice 9 weeks after NALM6, Matrigel and Ac-Y16 were subcutaneously co-injected. The weight of the subcutaneous tumours was significantly suppressed by Ac-Y16 in a dose-dependent manner. Flow cytometry analysis showed that the leukaemic infiltration was significantly inhibited in all organs with 1.5-2.0 mg of Ac-Y16. Leukaemic infiltrations in the brain were inhibited with 0.5 mg of Ac-Y16, and those in brain and bone marrow were also inhibited with 1.0 mg of Ac-Y16. With Ac-S16, a control-scrambled peptide, the only significant inhibition of the leukaemic infiltration was observed in bone marrow at a much higher dose. These data suggest that the multimeric YIGSR peptide can inhibit the tumour growth and metastasis of leukaemic cells and may be useful as a potential therapeutic reagent for leukaemic infiltrations.

Actins↗
PubMed1999

Chronic radiodermatitis following repeated percutaneous transluminal coronary angioplasty.

We review three patients who developed chronic radiodermatitis subsequent to undergoing multiple percutaneous transluminal coronary angioplasties (PTCAs). All patients had had chronic ischaemic heart disease (IHD) and had undergone lengthy PTCA on several occasions. The skin eruption was characterized by an atrophic rectangular plaque on the left upper back, presenting as mottled hyper- and hypopigmentation with reticulate telangiectasia. Histologically, the eruption demonstrated epidermal atrophy, hyalinized and irregularly stained collagen, and telangiectasia of superficial vessels in the dermis. Although the risk of radiation injury in most patients undergoing cardiac catheterization is low, this danger should not be ignored. In particular, patients with long-standing IHD and numerous repeated catheterizations to only one or two occluded coronary arteries should be considered at high risk.

Angioplasty, Balloon, Coronary↗
PubMed1999

ATP-induced Ca2+ response mediated by P2U and P2Y purinoceptors in human macrophages: signalling from dying cells to macrophages.

The activation of macrophages by various stimuli leading to chemotactic migration and phagocytosis is known to be mediated by an increase in intracellular Ca2+ concentration ([Ca2+]i). We measured changes in [Ca2+]i using a Ca2+ imaging method in individual human macrophages differentiated from freshly prepared peripheral blood monocytes during culture of 1-2 days. A transient rise in [Ca2+]i (duration 3-4 min) occurred in 10-15 macrophages in the vicinity of a single tumour cell that was attacked and permeabilized by a natural killer cell in a dish. Similar Ca2+ transients were produced in 90% of macrophages by application of supernatant obtained after inducing the lysis of tumour cells with hypo-osmotic treatment. Ca2+ transients were also evoked by ATP in a dose-dependent manner between 0.1 and 100 microm. The ATP-induced [Ca2+]i rise was reduced to less than one-quarter in Ca2+-free medium, indicating that it is mainly due to Ca2+ entry and partly due to intracellular Ca2+ release. UTP (P2U purinoceptor agonist) was more potent than ATP or 2-chloro-ATP (P2Y agonist). Oxidized ATP (P2Z antagonist) had no inhibitory effect. Both cell lysate- and ATP-induced Ca2+ responses were inhibited by Reactive Blue 2 (P2Y and P2U antagonist) to the same extent, but were not affected by PPADS (P2X antagonist). Sequential stimuli by cell lysate and ATP underwent long-lasting desensitization in the Ca2+ response to the second stimulation. The present study supports the view that macrophages respond to signal messengers discharged from damaged or dying cells to be ingested, and ATP is at least one of the messengers and causes a [Ca2+]i rise via P2U and P2Y receptors.

Adenosine Triphosphate↗
PubMed1999

Difficulty in writing Japanese semantic characters in a 9-year-old boy with Williams syndrome.

A 9-year-old boy diagnosed as having Williams syndrome was evaluated using psychological test batteries in order to clarify his ability in language and visual cognition. The subject had difficulty in writing some of the Japanese semantic characters (called Kanji) which he could otherwise read and understand. Although he could write the small components of which the Kanji characters were composed, he could not locate these correctly. This phenomenon is considered to be very similar to the difficulty in copying a figure observed clinically. The Kaufmann Assessment Batteries for Children clearly revealed that the boy had difficulty with the sub-test of spatial memory compared to his average score for simultaneous processing. This result is considered to be closely related to the difficulty in copying figures or writing Kanji characters. On the Illinois Test of Psycholinguistic Abilities, the present authors found that the subject's vocabulary was relatively good, although semantic and pragmatic problems remained. Clarifying the strong and weak points of the abilities of such patients will help to determine the most appropriate mode of education for them.

Apraxia, Ideomotor↗
PubMed1999

Endoscopic management of gastric varices using a detachable snare and simultaneous endoscopic sclerotherapy and O-ring ligation.

BACKGROUND: Cyanoacrylate injection is highly effective and is regarded as the treatment of choice in bleeding gastric varices in Europe, but intravenous injection of cyanoacrylate is not allowed in the USA and Japan because it may cause embolisms in other organs. Accordingly, we developed a new endoscopic combined treatment of endoscopic management of gastric varices using a detachable snare (EVLs) and simultaneous endoscopic sclerotherapy and O-ring ligation (EISL) (i.e. EVLs + EISL), and we prospectively evaluated its efficacy and safety. METHODS: Gastric varices were ligated with the loop of a detachable snare that opened to a diameter of 4 cm (EVLs). Then the residual varices around the ligated portion were sclerosed by ethanolamine oleate and the injected vessel was ligated using a pneumo-activated EVL device (EISL). The EVLs + EISL was performed in 35 patients: on an emergency basis in eight patients, on an elective basis in six patients and as primary prophylaxis in 21 patients. Liver function was classified as Child-Pugh class A in 12 patients, class B in 12 patients and class C in 11 patients. RESULTS: Endoscopic disappearance of gastric varices was obtained in 97.1% of the patients and they regressed in all patients. Haemostasis was achieved in all eight emergency cases. The 2-year cumulative non-recurrence rate was 85%, the 2-year cumulative non-bleeding rate was 92% and the 2-year cumulative survival was 80%. No patients died of bleeding from gastric varices. There were no serious short-term complications, such as haemorrhage, gastro-oesophageal perforation, ileus, or renal impairment. CONCLUSION: Combined EVLs + EISL appears to be a useful treatment for gastric varices due to its safety and good clinical outcome.

Endoscopy↗
PubMed1999

Intensity of snoring in patients with sleep-related breathing disorders.

The intensity of snoring was measured in 73 patients with snoring or sleep apnea using a noise meter. The mean intensity of snoring at 50 cm in front of the mouth was 61.7 dB in the supine position and 53.7 dB in the lateral position. There existed a definite correlation between the logarithmic transformation of the intra-esophageal pressure amplitude and the intensity of snoring in the supine and lateral decubitus positions. These findings suggest that the intensity of snoring may be a useful index for sleep-related breathing disorders.

Adult↗
PubMed1999

Evaluation of the auto continuous positive airway pressure efficacy by upper airway pressure measurement.

The efficacy of auto continuous positive airway pressure (CPAP) was prospectively evaluated in 11 obstructive sleep apnea cases by the upper airway pressure measurement. Their apnea plus hypopnea index decreased from 68.3+/-20.2/h to 0.5+/-0.9/h during manually adjusted and 9.6+/-14.5/h during auto CPAP The intraesophageal pressure decreased from -88.0+/-34.0 cm H2O to 11.9+/-7.2 cm H2O during manually adjusted and -26.0+/-13.7 cm H2O during auto CPAP. The manually adjusted CPAP level was 9.1+/-1.7 cm H2O and the maximum pressure of the auto CPAP was 9.4+/-2.0 cm H2O. Auto CPAP could automatically detect the optimal CPAP level. However, the efficacy of the auto CPAP was less than that of the manually adjusted CPAP.

Aged↗
PubMed1999

Magnolol inhibits leukotriene synthesis in rat basophilic leukemia-2H3 cells.

We have observed an inhibitory action of magnolol on the production of leukotriene (LT) C4 and LTB4, important lipid mediators in allergy and inflammation. IgE- and A23187-stimulated production of LTC4 and LTB4 was measured by radio-immunoassay (RIA) in the absence or presence of various concentrations of magnolol in intact rat basophilic leukemia (RBL)-2H3 cells. Magnolol dose-dependently inhibited synthesis of LTC4 and LTB4. Magnolol inhibited the IgE-mediated increase of intracellular calcium ion concentration, resulting in the inhibition of cytosolic phospholipase A2 (cPLA2) and possibly 5-lipoxygenase (5-LO), both calcium ion-dependent enzymes. In cell-free studies magnolol inhibited LTC4 synthase activity. LTA4 hydrolase activity was only inhibited at the higher concentration (2.5 x 10(-5)M). These results indicate that magnolol inhibits production of LTs by inhibiting PLA2, 5-LO, LTC4 synthase and LTA4 hydrolase which are essential for LT-synthesis. Magnolol may have anti-allergic effect by blocking LT-synthesis.

Animals↗
PubMed1999

Efficacy of beta-lactam antibiotics combined with gentamicin against penicillin-resistant pneumococcal pneumonia in CBA/J mice.

We examined the efficacy of gentamicin combined with beta-lactam antibiotics against penicillin-resistant Streptococcus pneumoniae (PRSP) in a noncompromised mouse model of pneumonia. In the presence of 8 mg/L (0.25 x MIC) and 16 mg/L (0.5 x MIC) of gentamicin, MICs of penicillin G against 23 strains of PRSP decreased from 1-4 mg/L to 0.03 mg/L in 14 (61%) and 23 strains (100%), respectively. A short-time killing study using strain 741 showed that 8 mg/L of gentamicin (0.25 x MIC) increased the killing activity of penicillin G, cefotaxime and imipenem (at 0.25, 1 and 4 x MIC) during a 6 h incubation period. Survival studies showed that the combined treatment of penicillin-G (160 mg/kg) and gentamicin (10 mg/kg), which commenced 2 days after infection (twice a day for 5 days), provided complete protection, while no animal survived when either antibiotic was used alone. A significant improvement in mortality was observed when a small dose of imipenem (2.5 and 10 mg/kg) was used with gentamicin. Our results suggest that gentamicin, when combined with beta-lactam antibiotics, especially imipenem, may be potentially useful against PRSP pneumonia in noncompromised individuals.

Animals↗