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Biomedical subjects

F Honda

Publications and source records attributed to F Honda.

At least 19 recordsLinked to original sources
PubMed2001

Central neurocytoma with unusually intense FDG uptake: case report.

Central neurocytoma is a benign neuronal tumor with a favorable prognosis. This tumor is typically characterized by decreased uptake of 18F-fluorodeoxy glucose (FDG) and any increased uptake of FDG in patients suffering from this tumor would be highly unusual. A case of central neurocytoma with an intense FDG uptake, combined with atypical histopathological features and a high proliferation index is reported in this paper. A 45-year-old male had a two months' history of right hemiweakness. Magnetic resonance (MR) imaging showed a large tumor in the right lateral ventricle. Positron emission tomography (PET) with FDG revealed high glucose metabolism in the tumor. The histological diagnosis was central neurocytoma with atypical features characterized by microvascular proliferation. The MIB-1 labeling index, ordinarily smaller than 2.0%, was 7.0%. Conventional radiotherapy, with a total dose of 50 Gy, was administered after the surgical treatment. The patient returned to his normal daily activities after the cessation of radiation therapy.

Cerebral Ventricle Neoplasms↗
PubMed1998

Properties of cattle bone powder-coated composite particles as high-performance and open column liquid chromatographic column packings.

Cattle bone powder (CBP) from natural resources was employed as a protein adsorbent instead of chemically synthesized hydroxyapatite (HA). Though a small amount of impurities was detected, CBP possessed a crystallinity similar to HA. Using CBP/40PE prepared from CBP and polyethylene beads (40 microns) by dry impact blending as an HPLC column packing, considerable correlation was observed between the elution concentrations of proteins and their pI. Such behavior was caused by the relatively large adsorption capacity for basic proteins. CBP/40PE could completely separate gamma-globulin from BSA also as an open column chromatographic support, under relatively low concentration.

Adsorption↗
PubMed1998

High-pressure system for Compton scattering experiments.

High-pressure apparatus for Compton scattering experiments has been developed to study the momentum distribution of conduction electrons in metals and alloys at high pressure. This apparatus was applied to observe the Compton profile of metallic Li under pressure. It was found that the Compton profile at high pressure could be obtained within several hours by using this apparatus and synchrotron radiation. The result on the pressure dependence of the Fermi momentum of Li obtained here is in good agreement with that predicted from the free-electron model.

Journal Article↗
PubMed1997

Resin glycosides. XXV. Multifidins I and II, new jalapins, from the seed of Quamoclit x multifida.

Alkaline hydrolysis of the ether-soluble resin glycoside fraction of seeds of Quamoclit (Q.) x multifida, a hybrid between Q. pinnata and Q. coccinea, gave new glycosidic acids, multifidinic acids A and B, along with two known glycosidic acids, quamoclinic acid A and operculinic acid A, and three organic acids, (2S)-2-methylbutyric acid, n-decanoic acid and n-dodecanoic acid. Further, as major ether-soluble resin glycosides, new jalapins named multifidins I and II, were isolated accompanied by quamoclins I-IV, which were previously obtained from seeds of Q. pinnata. The structures of multifidins I and II, and multifidinic acids A and B have been determined on the basis of chemical and spectral data.

Butyrates↗
PubMed1997

Chemical synthesis of H-phosphonate DNA without using N-protecting groups.

Oligodeoxyribonucleotides were synthesized by using N-unprotected H-phosphonate monomers. It was found that the amino groups of nucleosides were not modified during condensation where benzotriazolyloxy carbonium and phosphonium types of compounds were employed as condensing reagents. The most effective condensing reagent for rapid internucleotidic bond formation was found to be 2-(benzotriazol-1-yloxy)-1,1-dimethyl-2-(pyrrolidin-1- yl)-1,3,2- diazaphospholidinium hexafluorophosphate (BOMP). In the present H-phosphonate approach, 2-benzenesulfonyl-3-(3-nitrophenyl)oxaziridine (BNO) was successfully employed as a new oxidizing reagent for oxidation of the H-phosphonate linkages under anhydrous conditions.

Base Sequence↗
PubMed1993

[Experimental study on local cooling of the eyeball in ocular surgery (4). The local cooling effect on uveal blood circulation, intraocular pressure, and intravitreous pressure].

The effects of local cooling on the uveal blood circulation, intraocular pressure, and intravitreous pressure were evaluated. Saline solutions maintained at 10 degrees C and 35 degrees C were dripped on the rabbit ocular surface. After 5-minute dripping of 10 degrees C saline solution, the temperature decreased by 10.6 degrees C at the ciliary body, 7.7 degrees C at the choroid and 2.9 degrees C at the central region of the vitreous. Hydrogen clearance with electrolytically generated hydrogen gas was employed to measure the tissue blood flow, which fell to 82.9% of normo-thermal value at the ciliary body and 86.3% at the choroid. The intravitreous pressure dropped by 2.8 mmHg. After 30-minute dripping of 10 degrees C saline solution, the intraocular pressure dropped by 3.0 mmHg. We consider that the reduction of intraocular and intravitreous pressure during local cooling of the ocular surface is related to decrease in the uveal blood flow.

Animals↗
PubMed1989

[The local cooling effect of anterior chamber irrigation on the blood-aqueous barrier].

Local cooling effect on the breakdown of the blood-aqueous barrier (BAB) following anterior chamber irrigation, including additional direct irritation of the iris, was evaluated fluorophotometrically. The rabbit anterior chamber was irrigated with simulated aqueous humor (S-MA 2) the temperature of which was maintained at 35 degrees C or 10 degrees C. The fluorophotometry was performed before and 4, 24, 48 hours and 7 days after irrigation for 30 or 60 minutes. The temperature changes in the anterior chamber, retrolental vitreous body and posterior retina were also measured with a thermocouple during irrigation at 10 degrees C. The temperature of the anterior chamber and the retrolental vitreous fell to 15.0 degrees C and 28.2 degrees C, respectively, within 30 minutes after starting irrigation, whereas the temperature drop in the posterior retina was only 2.0 degrees C after 60 min. At 4 hours after 60-minute irrigation, the breakdown of the BAB was greater than following 30-minute irrigation. There was no significant difference in the BAB breakdown between eyes irrigated at 10 degrees C and 35 degrees C.

Animals↗
PubMed1981

Backward walking induced by L-5-hydroxytryptophan in mice.

An intraperitoneal administration of large doses of L-5-hydroxytryptophan (L-5HTP) induced dose-dependently a behaviour characterized by backward walking in mice. D-5-hydroxytryptophan (D-5HTP) and L-3,4-dihydroxyphenylalanine (L-DOPA) in the same doses failed to induce such behaviour. The backward walking induced by L-5HTP was blocked by a decarboxylase inhibitor, DL-alpha-methyl-DOPA, but was potentiated by a monoamine oxidase inhibitor (MAOI), tranylcypromine or pargyline. An intracerebral injection of L-5-hydroxytryptamine (5-HT) induced a similar backward walking which was potentiated by a MAOI. The backward walking induced by L-5HTP was completely inhibited by 5-HT and dopamine (DA) receptor blockers, but was not inhibited by alpha- or beta-adrenergic blocker, antihistamine or anticholinergic drug. On the other hand, zimelidine and clomipramine, 5-HT uptake inhibitors, markedly potentiated the backward walking, while desipramine had no effect. From the results, it appears that excess amounts of 5-HT formed from L-5HTP produced the backward walking by directly stimulating the central 5-HT receptors, and DA is also involved in the behaviour. This behaviour may serve as a good model to assess the central serotonergic activity of drugs.

5-Hydroxytryptophan↗
PubMed1980

A simple histochemical screening method for amine uptake.

A simple histochemical method for screening amine uptake in vitro is described. The filum terminale and the Vibratome sections of the caudate nucleus of reserpinized rats were used as the sources of noradrenaline (NA) and 5-hydroxytryptamine (5-HT), and as the sources of dopamine (DA) containing neurons, respectively. When incubated in an oxygenated medium (Krebs-Ringer) containing the corresponding amines, these preparations effectively accumulated the amines. 6-Hydroxytryptamine (6-HT) was used instead of 5-HT because of its stronger fluorescence and lower photo-decomposition of beta-carboline formed from 6-HT. The inhibitory patterns of representative uptake inhibitors obtained by the present method agreed well with those reported previously by biochemical methods. Effects of other types of drugs were also studied. The present method is a simple, rapid and non-radioisotopic method for determining amine uptake inhibiting action of a drug and the degree and selectivity in which it acts on the three kinds of amines.

Animals↗
PubMed1980

Dopamine receptor blocking activity of sulpiride in the canine exocrine pancreas.

The inhibitory effect of sulpiride on dopamine receptors was investigated in the exocrine pancreas of dogs anesthetized with pentobarbital and with the stomach ligated at the pylorus. All test substances were given intravenously. Dopamine, acetylcholine, histamine and secretin produced a dose-related increase in pancreatic juice secretion, though the dose-effect curves of these secretagogues differed in shape. Epinephrine, norepinephrine, isoproterenol, methamphetamine and serotonin had no secretagogue effects. The effects of acetylcholine and histamine were inhibited by atropine and cimetidine, respectively. The effect of dopamine was blocked by haloperidol, but not by atropine, cimetidine, phentolamine and propranolol. These results suggest that dopamine acts on specific dopamine receptors related to the exocrine pancreatic secretion. Haloperidol had no effect on the effects of acetylcholine and histamine, but did inhibit the secretin-induced secretion, though the inhibitory effect was to a lesser extent than on the dopamine response. Sulpiride and chlorpromazine also suppressed dose-dependently the dopamine-induced secretion. The inhibitory activity of sulpiride was almost the same as that of haloperidol, and 12 times more potent than that of chlorpromazine. Sulpiride was found to be a potent dopamine antagonist in the canine exocrine pancreas.

Acetylcholine↗