Complete anterior fracture-dislocation of the fourth lumbar vertebra.
Explore the source record for details and available documents.
Adolescent↗
Biomedical subjects
M Yoshioka
Publications and source records attributed to M Yoshioka.
The functional role of opioid receptors in acetylcholine release in the rat adrenal medulla.
The functional role of opioid receptors in acetylcholine release from splanchnic nerve terminals in the adrenal medulla was investigated in halothane-anesthetized rats. The extracellular acetylcholine level was measured by a newly developed in vivo adrenal microdialysis method. The potassium (K+)-evoked acetylcholine release from the splanchnic nerve terminals was inhibited by morphine (10 microM), a mu-opioid receptor agonist, and [D-Pen2,D-Pen5]enkephalin (DPDPE, 1 and 10 microM), a delta-opioid receptor agonist. These inhibitory effects of morphine and DPDPE were significantly abolished by naltrexone (9 mg/kg i.p.), a mu-opioid receptor antagonist, and naltrindole (9 mg/kg i.p.), a delta-opioid receptor antagonist, respectively. 5 alpha,7 alpha-beta-(-)- N-methyl-N-[7-(1-pyrrolidinyl)-1-oxaspiro(4,5)dec-8-yl]benzene acetamide (U69593, 10 microM), a kappa-opioid receptor agonist, had no influence on the K(+)-evoked acetylcholine release. The findings suggest that both mu- and delta-opioid receptors might have a functional role in acetylcholine release from splanchnic nerve terminals in the adrenal medulla of the rat. The present study indicates that adrenal microdialysis is a useful method for studying the control mechanism of adrenomedullary function in the rat in vivo.
Acetylcholine↗
mu-Opioid receptors modulate noradrenaline release from the rat hippocampus as measured by brain microdialysis.
The modulation of noradrenaline (NA) release via presynaptic opioid receptors in the hippocampus of freely moving rats was studied by the use of brain microdialysis. Extracellular levels of NA were estimated by assaying its concentrations in the perfusion fluid using high-performance liquid chromatography (HPLC) with electrochemical detection (ECD). Spontaneous NA levels were reduced by tetrodotoxin (1 microM) co-perfusion and were increased by peripheral administration of desipramine (5 and 10 mg/kg, i.p.). Addition of potassium (K+, 60 and 120 mM) to the perfusion fluid evoked a concentration-dependent release of NA. K+ (120 mM)-evoked NA release was markedly reduced by removal of calcium (Ca2+) from the perfusion fluid. These results indicate that both the spontaneous and the K(+)-evoked NA release measured by the use of brain microdialysis coupled with HPLC-ECD can be used as indices of neuronal release from the noradrenergic nerve terminals. A mu-opioid receptor agonist, morphine (0.01-10 microM), when co-perfused with K+ (120 mM), produced a reduction of K(+)-evoked NA release in a concentration-dependent manner. Neither co-perfusion with a high concentration of [D-Pen2, D-Pen5]-enkephalin (DPDPE) (10 microM), an agonist selective for delta-opioid receptors, nor with U-69593 (10 microM), an agonist selective for kappa-opioid receptors, modified the K+ (120 mM)-evoked release of NA. Morphine-induced (1 microM) inhibition of NA release was blocked by a mu-opioid receptor antagonist, naltrexone (3 and 9 mg/kg, i.p). Naltrexone by itself did not alter the spontaneous NA levels or the K(+)-evoked NA release.(ABSTRACT TRUNCATED AT 250 WORDS)
Analgesics↗
Neurochemical profiles in cerebrospinal fluid of stroke-prone spontaneously hypertensive rats.
The purpose of the present study was to evaluate stroke-prone spontaneously hypertensive rats (SHRSP) neurochemically by determining the cerebrospinal fluid (CSF) levels of acetylcholine (ACh), norepinephrine (NE) and serotonin (5-HT) as an index of central neuronal activity. The CSF ACh levels of 15- to 20-week-old SHRSP were significantly lower than those of age-matched Wistar Kyoto rats (WKY) both under the urethane/alpha-chloralose anesthesia and in freely moving conditions. The difference in the CSF ACh levels between SHRSP and WKY was more marked at 30-40 weeks. Sustained changes were not observed in the CSF NE and 5-HT levels. Thus, the progressive dysfunction in the central cholinergic system may characterize the pathophysiological state of this animal model with cerebral lesions caused by continuous high blood pressure.
3,4-Dihydroxyphenylacetic Acid↗
pH-independent controlled-release microspheres using polyglycerol esters of fatty acids.
The release of a drug having low solubility in a certain pH range from controlled-release microspheres using tetraglycerol pentastearate and tetraglycerol monostearate in combination as the matrix base showed pH dependence. Trepibutone, an acidic drug having lower solubility in an acidic medium, was released pH-independently from the microspheres which incorporated magnesium oxide, a solid base. It might have resulted from the pH inside the matrix being kept in an optimum range for drug release due to the incorporation of a solid base. On the other hand, the addition of water soluble acidic or basic excipients was ineffective to achieve pH-independent release. For papaverine, a basic drug, pH-independent drug-release characteristics could be achieved by adding Eudragit L100-55, an enteric polymer. It is thought that the enteric polymer increased the pores for drug release by dissolving in a higher pH range, where the solubility of papaverine is low, and thereby made the release pH-independent. Further, selecting a polyglycerol ester of a fatty acid with an appropriate hydrophile-lipophile balance as the matrix could yield a drug with the desired release rate at any pH.
Acrylic Resins↗
Crystallization of indomethacin from the amorphous state below and above its glass transition temperature.
The solid state crystallization of amorphous polymers, sugars, and inorganic glasses is often thought to be restricted to the region above the glass transition temperature, Tg, because insufficient molecular mobility (high viscosity) exists below Tg for nucleation and crystal growth. Here we report on the isothermal and nonisothermal crystallization of dry amorphous indomethacin in the temperature range of 20 degrees C above and below its Tg. These studies were carried out with two amorphous samples having different degrees of metastability relative to the crystalline state. It was shown that in both samples significant crystallization to the most stable polymorphic form occurred over several days when stored below Tg, and in some cases this process was preceded by the relaxation of one amorphous form to the other. At storage temperatures near to and above Tg the rates of crystallization increased as expected but a second less thermodynamically stable polymorph also appeared with the more stable crystal form. This behavior was explained by the possible relationship between the degree of metastability relative to the crystalline state of each amorphous form and the interfacial energy existing at the respective nucleation sites, in accord with the Ostwald step rule.
Calorimetry, Differential Scanning↗
Verotoxin induces hemorrhagic lesions in rat small intestine. Temporal alteration of vasoactive substances.
E. coli O157:H7 produces a cytotoxin active against Vero cells that has been termed verotoxin. In this study, we demonstrated that local intraarterial injection of verotoxin induced a decrease in blood flow and an increase in hemorrhagic lesions in rat small intestine. Significant increases in the area of hemorrhagic lesions were observed at 120 min after verotoxin injection. These lesions were produced by either verotoxin 1 or 2, but verotoxin 2 produced more extensive lesions. The temporal alteration of vasoactive substances in microcirculatory beds was determined after the administration of culture filtrate of E. coli O157:H7. Tissue-type plasminogen activator activity in regional plasma was significantly elevated as early as 30 min, suggesting that local fibrinolytic activation mediated by microvascular endothelium occurred. There was also early elevation of platelet-activating factor content in the ileal mucosa and its level remained significantly elevated thereafter. Intestinal blood flow, as determined by a laser Doppler flowmeter, started to decrease at about 45 min. The platelet-activating factor antagonist CV6209 was shown to attenuate the decrease in blood flow as well as the development of hemorrhagic lesions, demonstrating that platelet-activating factor is an important mediator for the microcirculatory damage. Accumulation of neutrophils demonstrated by myeloperoxidase activity in the intestinal mucosa and overproduction of oxygen-radicals from neutrophils of the mesenteric veins determined by the luminol-dependent chemiluminescence assay were observed at 60 min, corresponding with the decreased blood flow. Platelet-activating factor may be closely involved in the process of leukocyte accumulation and increased oxygen radical generation, because CV6209 also significantly attenuated these changes.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Involvement of muscarinic M1 receptor in the central pathway of the serotonin-induced Bezold-Jarisch reflex in rats.
The involvement of central muscarinic receptors in mediating the Bezold-Jarisch reflex elicited by injection of 5-hydroxytryptamine (5-HT) was studied in urethane/chloralose-anesthetized rats. Intravenous bolus injection of 5-HT (3.1 to 50 micrograms/kg) evoked a short-lasting dose-related bradycardia and hypotension, the Bezold-Jarisch reflex, accompanied with bursts of the efferent cervical vagus nerve. Systemic administration of atropine (0.1 and 1 mg/kg) blocked not only the cardiac responses but also the efferent cervical vagus nerve activity changes. Although the afferent cervical vagus nerve was also activated by an intravenous bolus injection of 5-HT, these responses were not altered by the systemic administration of even a high dose of atropine (1 mg/kg). Intracerebroventricular (i.c.v.) administration of pirenzepine (1 and 10 micrograms/10 microliters), a selective M1 receptor antagonist, caused a rightward shift of the 5-HT dose-response curve for efferent vagus nerve activity. In contrast, i.c.v. administration of muscarinic type 2 receptor antagonist, gallamine, and type 3 receptor antagonist, p-fluorohexahydrosiladifenidol, failed to alter the response in nerve activity to 5-HT. These results suggest that the activation of central nervous muscarinic receptors might be involved in mediating the Bezold-Jarisch reflex and that the subtype might belong to type 1.
Animals↗
Chromosome studies in 70 brain tumors with special attention to sex chromosome loss and single autosomal trisomy.
Chromosome analysis was performed on 70 brain tumors. Thirty-six tumors showed clonal karyotypes characterized by many autosomal abnormalities; 20 meningiomas revealed monosomy 22 as a consistent abnormality, and 12 gliomas showed various abnormalities frequently involving chromosomes 3, 7, and 22. Of the remaining 34 tumors, 24 had normal karyotypes and 10 had clonal cells with loss and/or an extra sex chromosome with single trisomy of chromosomes 3, 6, 7, or 14. Sex chromosome aneuploidy was mostly due to loss of the Y or an X chromosome and was observed in 25 tumors, usually together with autosomal abnormalities. In these tumors the average frequency of cells with sex chromosome aneuploidy was 52%, with a range from 12% to 100%. Loss of the Y was found significantly more frequently in tumors of aged patients. Chromosome analysis in materials subcultured for a long period showed a tendency for cellular selection in which clonal cells with many autosomal abnormalities disappeared rapidly and karyotypes having loss or an extra sex chromosome and/or trisomy 7 were present in an increasing proportion with advance of cell generations in vitro. We infer that the cells having loss of one sex chromosome or trisomy 7 have a proliferative advantage. And that cells bearing only these abnormalities may exist in normal brain tissue more abundantly than in any other body tissue. The possibility of tissue-specific aneuploid mosaicism in the normal tissue would allow an alternative interpretation for simple autosomal trisomy in solid tumors.
Adult↗
Dietary polydextrose affects the large intestine in rats.
We compared the effects of dietary polydextrose with those of dietary fibers on the luminal pH and morphology of the large intestine in rats. In Experiment 1, animals were fed diets supplemented with two levels (5 and 10 g/100 g) of polydextrose or dietary fiber (cellulose or galactomannan derivatives) for 52 d. Polydextrose and galactomannan derivatives significantly lowered large intestinal pH and increased the cecal weight and surface area compared with cellulose. However, the thickness of the cecal muscular layer was significantly less in the polydextrose-fed groups than in the cellulose-fed groups. In Experiment 2, rats were fed either a fiber-free diet or a diet containing 5, 10 or 20 g/100 g polydextrose for 92 d. Dietary polydextrose significantly acidified the cecal contents and promoted cecal mucosal growth but thinned the cecal muscular layer. The shape of colonic mucosa of the group fed the 20 g/100 g polydextrose diet was clearly different from that of the group fed the fiber-free diet. These findings indicate that the effect of polydextrose on the morphology of the large intestine is different from the effect of dietary fibers.
Animals↗
Coherent transition radiation in the far-infrared region.
Explore the source record for details and available documents.
Journal Article↗
Anti-hypertensive effect of oral controlled-release microspheres containing an ACE inhibitor (delapril hydrochloride) in rats.
An oral controlled-release drug delivery system based on microspheres of polyglycerol esters of fatty acids (PGEFs), was applied to an anti-hypertensive, delapril hydrochloride. The in-vitro release profile was controlled by selecting a PGEF with an appropriate hydrophilic-lipophilic balance value for the matrix. The microspheres from which 80% of the drug was released in 6 h were orally administered to rats. The plasma concentration of the active metabolite was sustained after administration of the microspheres in comparison with administration of a solution. The in-vivo release profile was in good agreement with the in-vitro release profile. When the microspheres were administered, the pharmacological effect of delapril hydrochloride on the angiotensin I-induced pressor response was also sustained showing consistency with the plasma concentration-time curve.
Administration, Oral↗
Involvement of 5-HT3 receptors in the initiation of pharyngeal reflex.
Activation of peripheral serotonin (5-HT) receptors, classified as 5-HT3, was shown to elicit the pharyngeal reflex in anesthetized rats. Intravenous bolus injection of 5-HT (6.25-50 micrograms/kg) evoked rhythmic bursts in the efferent pharyngeal branch of the vagus nerve in a dose-related manner, whereas afferent superior laryngeal nerve activity was not altered by even a high dose of 5-HT. The pharyngeal branch response was blocked by pretreatment with a selective 5-HT3-receptor antagonist YM060 (1 and 10 micrograms/kg). A 5-HT3-receptor agonist, 2-methyl-5-HT, also produced a rhythmic burst in the pharyngeal branch, and this effect was blocked by YM060. Intrapharyngeal pressure was rhythmically increased by both 5-HT (12.5-50 micrograms/kg) and 2-methyl-5-HT (6.25-50 micrograms/kg) in a dose-related manner. Both of these effects were antagonized by YM060 (10 micrograms/kg). In addition, a neuromuscular blocking agent vecuronium (1 mg/kg iv) completely inhibited the 5-HT-induced increase in pharyngeal pressure. After a bilateral vagotomy was performed below the nodose ganglia, the 5-HT-induced increase in pharyngeal branch activity was abolished, whereas a bilateral sectioning of the superior laryngeal nerve did not alter the 5-HT-induced increase in pharyngeal branch activity. Retrograde tracing with fluorescent dye (fast blue) was used to identify the cell bodies of the pharyngeal branch. Pharyngeal motoneuron cell bodies were distributed along the entire length of the nucleus ambiguus. Our results suggest that exogenous 5-HT-induced increases in pharyngeal branch activity and intrapharyngeal pressure may be initiated by the peripheral 5-HT3-receptors of the vagal nervous system and that this may be a viscerosomatic reflex.
Animals↗
Expression of cytokines in brain lesions in subacute sclerosing panencephalitis.
We analyzed frozen brain specimens from three patients with subacute sclerosing panencephalitis (SSPE) for the presence of interleukin (IL)-1 beta, IL-2, IL-6, tumor necrosis factor (TNF), lymphotoxin (LT), and interferon (IFN)-gamma using immunocytochemical techniques. We detected these cytokines in SSPE brain lesions demonstrating extensive cellular infiltrates, demyelination, and gliosis. Double-label immunocytochemistry, using cell-specific markers, showed that positive immunoreactivity for these cytokines was present on both infiltrating cells and resident brain cells. We also found IL-6, TNF, and IFN-gamma at lower levels in brain tissue from a patient with progressive multifocal leukoencephalopathy. In contrast, normal control brain sections showed no reactivity for any of the cytokines. These findings indicate that IL-1 beta, IL-2, IL-6, TNT, LT, and IFN-gamma may be produced in SSPE lesions and may be involved in the lesion pathogenesis of SSPE.
Adult↗
Expression of HIV-1 and interleukin-6 in lumbosacral dorsal root ganglia of patients with AIDS.
We examined the immunopathology and the expression of human immunodeficiency virus type 1 (HIV-1) in lumbosacral dorsal root ganglia (DRGs) from 16 patients with acquired immunodeficiency syndrome (AIDS) and 10 HIV-1-seronegative controls. Using in situ hybridization, we detected HIV-1 RNA in a few perivascular cells in DRGs from five of 16 AIDS patients (31%). In addition, using polymerase chain reaction, we detected HIV-1 DNA more frequently in DRGs from four of five AIDS patients (80%) examined. We detected interleukin-6 (IL-6) immunoreactivity in endothelial cells in DRGs from seven of 16 AIDS patients (44%) but from none of 10 HIV-1-seronegative controls (0%). We found more nodules of Nageotte, CD8+ T lymphocytes, and intercellular adhesion molecule-1 (ICAM-1)-positive endothelial cells and mononuclear cells in DRGs from AIDS patients than in DRGs from controls. Increased numbers of nodules of Nageotte in DRGs of AIDS patients were associated with detection of HIV-1 RNA by in situ hybridization and detection of IL-6 by immunohistochemistry. We conclude that low levels of replication of HIV-1, through cytotoxic T lymphocytes or expression of cytokines, may play a role in the subclinical degeneration of sensory neurons frequently observed in DRGs of AIDS patients.
Acquired Immunodeficiency Syndrome↗
Identification of a previously unknown compound as 2'-deoxycytidine found in the plasma of breast cancer patients under combined chemotherapy.
In an attempt to find an end-point for cancer chemotherapy, this study was designed to measure the adenine compounds in the plasma of breast cancer patients using HPLC with a selective reagent for adenine bases. The patients were treated by chemotherapy using cyclophosphamide, methotrexate and 5-fluorouracil. Blood was collected in tubes containing EDTA, the plasma separated by centrifugation and analysed by HPLC. An early peak due to the fluorescent derivative of an unknown compound reacted with bromoacetoaldehyde and its concentration appeared proportional to the chemotherapeutic courses of treatment. The compound in its native state without fluorescent derivatization was efficiently purified by using columns of DEAE- and CM-Sephadex. Its UV spectrum revealed maxima at 271, 280 and 272 nm in solutions of pH 7, pH 3 and pH 12, respectively. The electrophoretograms showed that it was neutral, positively and negatively charged at pH 7, pH 3 and pH 12, respectively. Thin-layer chromatograms showed that it had the same Rf as 2'-deoxycytidine (dCyd) which was confirmed by a positive reaction for deoxyribose. It was concluded that bromoacetoaldehyde formed a weakly fluorescent product with dCyd which gave rise to the early peak in the anion exchange chromatograms. From the calculation of the recovery obtained by the purification process, the cancer patients undertaking more than 12 courses had a dCyd level of approximately 20 mM while the corresponding figure in normal volunteers was less than 1 mM. These results may be useful in assessing the status of the cancer patients.
Antineoplastic Combined Chemotherapy Protocols↗
Analyses of metal ions in spider venoms in relation to insecticidal activity of clavamine.
To elucidate insecticidal activity of spider toxins, metal ions in venoms and in the bodies were determined by thin layer chromatography, spark source mass spectrometry, ion chromatography, inductively coupled plasma emission spectrometry and atomic absorption spectrometry. Two kinds of spiders were used, Nephila clavata and Nephila maculata. Metals from their venom glands were extracted with hydrochloric acid and the metal concentrations were almost the same in the two species. Many kinds of metals, Fe, Zn, Pb, Cu, Ca, Mg, Na, P and S were found at higher levels in the venoms at concentrations higher than in the bodies. The contents of metal ions were low in the dragonfly and the cicada which are considered to be preys. Clavamine, the main insecticidal component in N. clavata, was effective on larvae of a mosquito with Ca2+, Fe3+ or Pb2+, but ineffective with Mg2+, Zn2+, Fe2+ or Cu2+. It is suggested that the metal chelates play an important role in the intoxication and detoxication of the spider toxins.
Animals↗
Finding of primitive polyamine toxins in the venom of a joro spider, Nephila clavata.
A series of joro spider toxins, novel polyamines sharing a common moiety of 2,4-dihydroxyphenylacetyl cadaverine, have been identified using various bioassays, such as inhibition of a glutamatergic transmission and insecticidal activity. In this paper, we tried to chemically find still unknown polyamine toxins in the venom of a joro spider, N. clavata, by several analytical methods based on the characteristics of the common moiety. An aqueous extract from 3000 venoms was separated by preparative high performance liquid chromatography (HPLC). The polyamine toxins were detected by monitoring the fluorescence produced in an on-line reaction of o-phthalaldehyde with amino groups and UV absorption of the phenol group. Two compounds in minute quantity were purified and analyzed by gas-liquid chromatography (GC) and HPLC, which we specifically developed for the simultaneous determination of amino acids and polyamines of the toxins. Judging from the constituents of the hydrolysate by GC and HPLC and the molecular weights determined by fast atom bombardment mass spectrometry, the two compounds were estimated to be N-(2,4-dihydroxyphenylacetyl-L-asparaginyl)-N'- (3-aminopropyl-beta-alanyl) cadaverine and N-(4-hydroxyphenylacetyl-L-asparaginyl)-N'-(3-aminopropyl-beta-ala nyl) cadaverine. These compounds were small in content and molecular weight compared with hitherto known toxins. Both were presumed to be biochemically primitive toxins and were named spidamine and joramine, respectively.
Animals↗