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Biomedical subjects

H Noguchi

Publications and source records attributed to H Noguchi.

At least 451 records · Page 25Linked to original sources
PubMed1978

[On deffect of cobalt-chromium-nickel alloy for dental castings (author's transl)].

We studied about castability and microporosity of cobalt-chromium-nickel alloy for dental casting in various methods of fusion and casting. The combinations of fusion and casting were induction fusion and centrifugal casting, arc discharge fusion and argon gas pressure casting and oxy-acetylene flame fusion and centrifugal casting. The following results were obtained. 1. The amount of microposity was smaller, when only mold temperature was low, and as mold temperature and casting temperature were high, castability was better. 2. The arc discharge fusion and argon gas pressure casting was the best method about castability and microporosity in three methods. Second method was the induction fusion and centrifugal casting. 3. In the induction fusion and centrifugal casting, blowing arong gas of 1 l/min to molten metal to protect the metal from oxidization improved the castability the best, but amount of microporosity was large, so that it was needed to lower the mold temperature in this condition. 4. The oxyacetylene flame fusion and centrifugal casting was not suitable for the casting of Co-Cr alloy "Regalloy No. 3", for the alloy was made for the induction fusion casting.

Chromium Alloys↗
PubMed1977

Optimum humidification of air administered to a tracheostomy in dogs. Scanning electron microscopy and surfactant studies.

The effect of the inhalation of dried (less than 40% water-saturation) or humidified air (100% water-saturation at 25, 30, 35 and 40 degrees C) was studied in dogs in which a tracheostomy had been performed to determine the optimal humidity. After inhalation for various periods, the dogs were killed and pieces of lung tissue were excised for analysis of surfactant. Sections of the trachea and the primary to tertiary bronchi were taken for scanning electron microscopic examination. Structural changes were observed in the trachea of dogs inhaling dried at and in the tertiary bronchi of dogs inhaling 100% water-saturated air at 35 degrees C. No changes was observed after 24 h in dogs which had inhaled 100% water-saturated air at 25 degrees C under anaesthesia or at 30 degrees C without anaesthesia. Consequently, the optimal range of humidity was determined to be 100% water-saturation between 25 and 30 degrees C.

Air↗
PubMed1977

Dopamine receptor blocking activity of sulpiride in the central nervous system.

Effects of sulpiride on the central nervous system were studied in catalepsy induction (I) and antagonism to gnawing behaviour (II) induced by apomorphine and methamphetamine in normal rats, and in antagonism to rotational behaviour (III) induced by apomorphine and methamphetamine in rats with substantia nigra unilaterally lesioned chronically by microinjection of 6-hydroxydopamine. Sulpiride was administered orally and intraventricularly, and the effects of sulpiride were compared to those of haloperidol and chlorpromazine administered through the same routes. In oral administration, sulpiride was almost inactive in (I), and was several hundreds to a thousand times less potent than haloperidol in (II) and (III), while chlorpromazine was 20 to 150 times stronger than sulpiride. In intraventricular administration, sulpiride was almost equipotent to haloperidol in (I), and was equally effective to or 2 to 3 times more effective than halopridol in (III), although several times less in all respects. These findings suggest that sulpiride is essentially a potent inhibitory substance on dopamine receptors in the central nervous system and the rather weak central effects of peripherally given sulpiride are due to poor penetration through the blood brain barrier.

Administration, Oral↗
PubMed1977

Species differences in metabolism of tiaramide hydrochloride, a new anti-inflammatory agent.

1. Urinary excretion of the radioactivity in 24 h after oral administration of [14C]tiaramide hydrochloride was 67% of the dose in mice, 59% in rats, 41% in dogs and 74% in monkeys. 2. The serum half-lives of tiaramide after intravenous administration were approximately 0-2 h in mice, 0-8 h in rats and 0-5 h in dogs. 3. Marked species variations were noted in the composition of metabolites in the serum and urinary radioactivity. The major metabolites found were 1-[(5-chloro-2-oxo-3(2H)-benzothiazolyl)acetyl]-piperazine (DETR) and 4-[(5-chloro-2-oxo-3(2H)-benzothiazolyl)acetyl]-1-piperazineacetic acid (TRAA) in mice, TRAA and 4-[(5-chloro-2-oxo-3(2H)-benzothiazolyl)acetyl]-1-piperazineethanol 1-oxide (TRNO) in rats, TRNO and tiaramide-O-glucuronide (TR-O-Glu) in dogs, and TRAA and TR-O-Glu in monkeys. 4. The binding of tiaramide to plasma protein of the various species of animals and human was about 24-34% and the extent of the binding of tiaramide to human plasma protein was independent of drug concentration within the range of 1-100 micron.

Animals↗
PubMed1977

[Studies on the contract of the casting. (II) Influence of core inside the cast (author's transl)].

A alloy has its constant coefficient of casting shrinkage, but its value is changed by casting conditions. This time, we studied with effect of core which exist inside the cast. The results obtained were as follows: 1. The more the strength of core material increases, the smaller the coefficient of casting shrinkage becomes. 2. The smaller the thermal expansion coefficient of core material in solid state, the smaller the casting shrinkage. 3. In case of Silver-Palladium-Gold casting alloy, its actual casting shrinkage (y) has a multiple correlation with the compressive strength (x1) of core material in high temperature, and with the difference (x2) of the original casting shrinkage of the alloy from the casting shrinkage of core material, that is, y = -0.0023x1 + 0.0087x2 + 1.4927 4. Silver-Indium casting alloy is hard to be influenced by the quality of core material, for the alloy has a small shrinkage force.

Dental Alloys↗
PubMed1976

Synthesis of apoferritin in mouse peritoneal macrophages. Characterization of 20 S particles.

Apoferritin particles were found in mouse peritoneal macrophages cultured in vitro. They were found as 20S particles in the "ribosomal fraction" of macrophages labeled with L-[14C]glutamic acid. Possibilities that they were breakdown products of ribosomes or of other well-known contaminants of the ribosomal fraction were excluded because they did not incorporate [5-3H]uridine. They were resistant to RNase and were relatively resistant to detergent. The antibody against horse spleen apoferritin precipitated about 70% of the particles in the 20S region, judging by measurement of radioactivity. On in vitro incubation with Fe2+ and suitable oxidizing agents the sedimentation coefficient of 80% of the 20S particles changed to about 60S, which corresponds to that of ferritin. SDS-polyacrylamide gel electrophoresis revealed the presence of subunit structures with the same molecular size as that of mouse liver apoferritin. Under the electron microscope, the particles appeared spherical with a relatively uniform diameter of about 130 A.

Animals↗
PubMed1976

PC-904, a novel broad-spectrum semisynthetic penicillin with marked antipseudomonal activity: microbiological evaluation.

PC-904, sodium 6-{d(-)-alpha-(4-hydroxy-1,5-naphthyridine-3-carboxamido) phenylacetamido}-penicillanate, is a novel semisynthetic penicillin derivative that possesses a broad spectrum of in vitro and in vivo antibacterial activities. In low concentrations, PC-904 inhibits growth against large proportions of the gram-positive and gram-negative organisms susceptible to carbenicillin and gentamicin. In addition, PC-904 is several times more potent than carbenicillin against organisms such as Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Proteus vulgaris, Shigella, Salmonella, Neisseria gonorrhoeae, and Bacteroides fragilis. Most striking are the inhibitory effects of PC-904 against P. aeruginosa and K. pneumoniae. Against these two clinical isolates, PC-904 is, respectively, 35 and 100 times more active than carbenicillin. The minimum inhibitory concentrations of PC-904 against P. aeruginosa are comparable to those of gentamicin. PC-904 acts bactericidally. The effect of inoculum size on the antibacterial activity is often small and generally comparable to carbenicillin. The rate of binding to serum protein is high (88 to 98%), but the effect of the addition of serum on the drug's activity is not marked, because such binding is reversible. It is confirmed that PC-904 has a very potent in vivo antibacterial activity against gram-negative and gram-positive organisms. Against systemic infections with P. aeruginosa, K. pneumoniae, and E. coli in mice, PC-904 is 7 to 10 times, over 8 times, and 2 to 15 times more active than carbenicillin, respectively.

Ampicillin↗