Search PubMed⌕ Search

Biomedical subjects

Y Hatano

Publications and source records attributed to Y Hatano.

At least 127 records · Page 7Linked to original sources
PubMed1992

Effects of sea water pollution on chicken embryos.

Organic matter and heavy metal contamination in sea water obstruct vital functions of chicken embryos and interrupt their growth. Histological examination of contaminated fetuses showed a menacing growth of abnormal protuberances in the lungs as well as highly impeded formation of capillaries, although the windpipes exhibited normal expansion. Compared with controls, liver tissue also showed retarded growth accompanied by decrease in liver weight. Consequently, vital metabolic functions were impaired, hydropsy and evisceration developed, and fetuses were deformed.

Abnormalities, Drug-Induced↗
PubMed1992

Direct vasoconstrictor and vasodilator effects of propofol in isolated dog arteries.

We have measured the direct effects of propofol 10(-7)-10(-4) mol litre-1 on isolated canine cerebral, coronary, mesenteric, femoral and renal arteries. In arterial strips precontracted submaximally with potassium chloride or prostaglandin F2 alpha (PGF2 alpha), propofol induced further contractions at low concentrations (10(-6)-10(-5) mol litre-1) and relaxation at high concentrations (10(-4) mol litre-1). Intrafat, which contains soya bean oil, egg phosphatide and glycerol in similar concentration to the emulsion formulation of propofol, had a small relaxant effect at a concentration corresponding to propofol 10(-4) mol litre-1. In humans, clinically relevant plasma concentrations of propofol have been reported to be 1-5 x 10(-5) mol litre-1, 97-99% of which is bound to plasma proteins. Therefore, the results obtained in this study demonstrated that clinically relevant concentrations of propofol did not have direct vasodilator effects.

Animals↗
PubMed1992

Mechanism underlying mannitol-induced relaxation in isolated monkey cerebral arteries.

The addition of mannitol (25, 50, and 100 mM) increased osmotic pressures of the bathing media from 293 to 317, 340 and 383 mosmol, respectively, and elicited a dose-related relaxation in monkey cerebral artery strips precontracted with K+ or prostaglandin F2 alpha. This relaxation was attenuated by ouabain, amiloride, catalase and oxyhemoglobin but was not influenced by superoxide dismutase and indomethacin. Combined treatment of the strips exposed to ouabain and amiloride with catalase produced an additional inhibition. H2O2 produced a contraction, which was abolished by catalase. Replacement of entire NaCl with choline chloride markedly suppressed the mannitol-induced relaxation. Relaxations caused by the addition of hypertonic NaHCO3 (25 and 50 mM) were also attenuated by ouabain and amiloride but were unaffected by catalase and oxyhemoglobin. It may be concluded that the mannitol-induced cerebroarterial relaxation is associated with an activation of the electrogenic Na+ pump and the Na(+)-H+ exchange and probably with scavenging of hydroxyl radicals responsible for the arterial contraction. On the other hand, hypertonic NaHCO3 relaxes monkey cerebral arteries, possibly due to an activation of the Na+ pump and the Na(+)-H+ exchange.

Amiloride↗
PubMed1992

Attenuation of gastric effects of famotidine by preoperative administration of intravenous fluids.

Effects of preoperative administration of intravenous crystalloids on the gastric effects of famotidine were studied in 89 patients scheduled for elective surgery in the afternoon. Patients were randomly assigned to one of six groups. Groups P1, P2, and P3 received 2.0 mL of intramuscular saline (placebo) and groups F1, F2, and F3 received 20 mg of intramuscular famotidine 1 h before anesthesia. All patients fasted for 14-18 h before surgery. No fluid was administered to groups P1 and F1 preoperatively, whereas 500 mL of intravenous fluid was given to the other groups over a period of 4-5 h before anesthesia: a maintenance fluid with 10% glucose to groups P2 and F2, and lactated Ringer's solution without glucose to groups P3 and F3. After anesthetic induction, the stomach was aspirated using a nasogastric tube and volume and pH of the contents were measured. The gastric volume was significantly less in F2 (4.2 +/- 1.2 mL, mean +/- SEM) than in P1 (30.7 +/- 5.5 mL) (P less than 0.01) and in F3 (12.7 +/- 2.1 mL) than in P3 (26.8 +/- 4.4 mL) (P less than 0.05). There was no significant difference between P2 (23.4 +/- 4.6 mL) and F2 (17.5 +/- 3.5 mL). Mean pH values were significantly higher in F1 (6.82 +/- 0.48) than in P1 (3.21 +/- 0.72) (P less than 0.01). No significance was observed between P2 (3.65 +/- 0.62) and F2 (4.53 +/- 0.77), or P3 (3.17 +/- 0.81) and F3 (5.03 +/- 0.80).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Halothane and isoflurane inhibit endothelium-dependent relaxation elicited by acetylcholine.

The purpose of this study was to determine whether volatile anesthetics modify the release of endothelium-derived relaxing factor. We examined the effects of halothane and isoflurane on endothelium-dependent relaxation and 3',5'-cyclic guanosine monophosphate formation elicited by acetylcholine and ionophore A23187 in isolated rat aorta. Halothane and isoflurane (1%-2%) significantly attenuated acetylcholine-induced relaxation of the phenylephrine-contracted aorta but had no significant effect on relaxation induced by A23187, nitroprusside, and nitroglycerin. Basal and A23187 (10(-7) M)-stimulated levels of 3',5'-cyclic guanosine monophosphate were slightly lowered by halothane and isoflurane (2%). In contrast, the increase of 3',5'-cyclic guanosine monophosphate elicited by acetylcholine (10(-5) M) was significantly attenuated by halothane (2%) and abolished by isoflurane (2%). These findings indicate that halothane and isoflurane strongly inhibit the release of endothelium-derived relaxing factor elicited by acetylcholine.

Acetylcholine↗
PubMed1992

Multiplication and immunogenicity of a temperature-sensitive and thymidine kinase-deficient strain of Aujeszky's disease virus in pigs.

Hysterectomy-produced colostrum-deprived 5- and 27-day-old pigs were inoculated intramuscularly (IM) or intranasally (IN) with the temperature-sensitive and thymidine kinase-deficient ZHtsTK- strain of Aujeszky's disease virus (ADV), and the nasal swabs and organs of the pigs were periodically collected for virus isolation. No abnormal clinical signs were observed in these pigs, except for a mild febrile response. Viral shedding in the nasal swabs with low titers was detected in the pigs inoculated IN between postinoculation day (PID) 1 and 5, but not in those of the pigs inoculated IM. No contact infection, however, occurred in the cohabiting pigs. Viruses with low titers were isolated only from the muscles and lymph nodes at the site of inoculation in the pigs inoculated IM on PID 2 and 4, but not from any organs of the pigs inoculated IN. To investigate the ability of the ZHtsTK- strain to establish a latent infection in pigs, the pigs inoculated IM or IN with the ZHtsTK- strain were treated with prednisolone. No virus was detected in the trigeminal ganglia or the nasal swabs collected after prednisolone treatment by the cocultivation method. The immunological evaluation demonstrated that immunization of pigs with this strain was effective in preventing clinical signs caused by ADV infection. The duration of virus shedding was markedly shortened in immunized pigs, particularly in those immunized twice and the total quantity of virus recovered from immunized pigs was reduced in comparison with unimmunized pigs.

Animals↗
PubMed1992

Analysis of swinepox virus antigens using monoclonal antibodies.

Seventeen monoclonal antibodies (MAbs) against swinepox virus (SPV) were produced and characterized. These MAbs were classified into eight groups (A through H) on the basis of the molecular weight of the polypeptides which they recognized and the staining patterns of antigens in SPV-infected cells by the indirect immunofluorescent (IF) technique. The MAbs belonging to groups A, B, C and G recognized late antigens in cytoplasmic inclusion bodies with molecular weights of 97 kD, 65 kD, 48 kD and 15 kD, respectively. The MAbs belonging to groups D and H respectively recognized 35 kD and 12 kD late antigens, which first appeared in cytoplasmic inclusion bodies and spread to the cytoplasms and surface membranes of the infected cells. The MAb of group F recognized an 18 kD late antigen with granular distribution in the cytoplasm. The MAbs of group E recognized a 32 kD early antigen. Although all the MAbs belonging to the six groups (A, D through H) were specific for SPV, some of those belonging to groups B and C showed cross-reactivity with members of the other genera of poxviridae. An MAb in group B, SP14, cross-reacted with orf and rabbit fibroma viruses. Two MAbs in group C, SP24 and SP32, cross-reacted with vaccinia, cowpox, ectromelia, and rabbit fibroma viruses. These findings indicate that at least two SPV antigens contain cross-reactive epitopes with different genera of poxviridae.

Animals↗
PubMed1992

[Annual changes of bacteria isolated from urinary tract infections and their susceptibility to new quinolone agents].

Statistical analyses were conducted on bacterial strains isolated from the urine of patients with urinary tract infections (UTI) in the Department of Urology at Aichi Medical University from January 1988 through December 1991. The drug sensitivity of the bacterial strains isolated from patients with complicated UTI between 1988 and 1991 was analyzed and compared. Among the outpatients with uncomplicated UTI, a total of 352 strains were isolated. E. coli was isolated the most frequently (90.1%). Among the outpatients with complicated UTI, a total of 829 strains were isolated. Enterococcus sp. was isolated the most frequently (21.2%). P. aeruginosa and S. aureus showed a tendency to increase. Among the inpatients with complicated UTI, a total of 671 strains were isolated. Enterococcus sp. was isolated the most frequently (22.5%). P. aeruginosa and S. aureus showed a tendency to increase, while E. coli and Enterobacter sp. showed a tendency to decrease. E. coli was highly sensitive to all drugs except ampicillin (ABPC). Proteus sp. and Klebsiella sp. were highly sensitive to norfloxacin (NFLX). P. aeruginosa was highly sensitive to gentamicin (GM). The frequency of NFLX-sensitive P. aeruginosa significantly dropped from 84.6% to 40.9% among the outpatients (P < 0.01), and from 75.0% to 44.4% among inpatients (P < 0.05). S. aureus was highly sensitive only to minocycline (MINO). The frequency of NFLX-sensitive S. aureus significantly dropped from 66.6% to 23.3% among inpatients (P < 0.05). Enterococcus sp. was highly sensitive to ABPC and MINO. Of the new quinolones, tosufloxacin (TFLX) had the strongest antimicrobial activity followed by (ciprofloxacin) CPFX on all the bacterial strains tested.

Bacteria↗
PubMed1991

Monensin-mediated antiport of Na+ and H+ across liposome membrane.

The mechanism of monensin-mediated transport of Na+ and H+ across large unilamellar liposome membrane was investigated. The inside negative membrane potential (delta psi) was generated by the addition of monensin to the liposomes with an outward Na+ gradient. The effects of intravesicular H+ bufferring power and medium pH on the initial rates of delta psi formation, Na+ efflux and H+ influx were examined. The results showed that (i) the initial Na+ flux (JNa) was larger than the initial H+ flux (JH) at any H+ bufferring power, (ii) the JH increased with increasing inner buffer concentration, but the effect of H+ bufferring power on the JNa was small, (iii) the initial rate of delta psi formation increased linearly with the increase in the value of (JNa-JH), and (iv) the JNa increased with increasing H+ concentration. The generation of delta psi was not due to H+ leak from the liposome, since the delta psi was generated even when H+ concentration gradient was inwardly directed. The monensin-mediated transport of Na+ and H+ in this system occurred at the ratio of Na+/H+ greater than 1.0 and the resultant net electric charge efflux is the cause of the inside negative membrane potential. Tetraphenylphosphonium retarded both the delta psi formation and the H+ influx, but did not affect the Na+ efflux, suggesting that the driving force of H+ influx is the inside negative membrane potential generated by Na+ efflux. This idea also well accounts for the observed H+ bufferring power effects on the Na+ efflux, H+ influx and delta psi formation. It was suggested that Na+ was transported in the form of 1:1 complex between protonated monensin and Na+.

Arylsulfonates↗
PubMed1991

Molecular cloning and analysis of forked locus in Drosophila ananassae.

Drosophila ananassae, in spite of its unique genetic characters including high mutability and high frequency of male recombination has been little studied at the molecular level. Since the species is very similar to D. melanogaster, it is natural to expect that the high spontaneous mutation rate and male recombination may be caused by inserted mobile DNA elements, as in D. melanogaster. The present study was designed to determine whether or not most spontaneous mutations of the forked locus of D. ananassae are caused by insertion sequences as is found in D. melanogaster. I cloned the forked locus of D. ananassae, using forked DNA from D. melanogaster as a probe and investigated the molecular structure and transcription of the gene by Southern and Northern analyses. The results suggest that the restriction map and transcriptional patterns of the forked locus of D. ananassae are similar to those of D. melanogaster, while the spontaneous mutations available in D. ananassae are induced quite differently from those that have been described in D. melanogaster; in four (f;cd, f10-14, f49 and f86) out of eight forked alleles, neither insertions nor deletions were detected around the forked coding region. Forked transcripts are expressed in a pattern which is very similar to that of D. melanogaster and were all of normal size in these mutants. The other four mutants (f10-3, f9-10, f83i and f79b) had insertion sequences upstream of the forked coding region, while transcripts of the forked gene were of normal size. Hence, none of the eight mutations studied appear to affect the structure of the forked transcripts.

Animals↗
PubMed1991

Age-dependent alterations in the response of isolated rat aortas to thiobarbiturates.

Responses to thiamylal and thiopental were compared in helical strips of rat thoracic aortas of different ages (5-6, 10-12 and 20-22 weeks old), precontracted partially with phenylephrine or prostaglandin F(2alpha) (PGF(2alpha)). Thiamylal and thiopental, in concentrations of 3 x 10(-5) to 10(-4) M, produced a dose-dependent relaxation in aortas at 5-6 weeks of age, no significant change of tension in those at 10-12 weeks of age, and a marked constriction in those at 20-22 weeks of age. These thiobarbiturates, in a high concentration of 10(-3) M, produced a profound relaxation in aortas at any age studied. It is concluded that the responses to thiobarbiturates of thoracic aorta precontracted with phenylephrine or PGF(2alpha) alter with age.

Journal Article↗
PubMed1991

The relaxing effects of barbiturates in vascular smooth muscle of rat aorta.

The effects of thiamylal and pentobarbital on contractions mediated through the influx of extracellular Ca(++) and the release of intracellularly stored Ca(++) were compared in rat aortic strips. Thiamylal (3 x 10(-5) M to 10(-3) M) and pentobarbital (10(-4) to 10(-3) M) significantly attenuated the contraction induced by KCl (20 mM), and shifted the dose-response curve for Ca(++) of KCl (20 mM)-treated strips downwards and to the right. Caffeine (10(-2) M)-induced contraction was significantly attenuated by thiamylal at concentrations greater than 10(-4) M and by pentobarbital at 3 x 10(-4) M. Only a high concentration (10(-3) M) of these barbiturates significantly inhibited the contractions induced by norepinephrine (NE, 10(-6) M) in Ca(++)-free medium. Contraction of strips without endothelium by a Ca(++) ionophore, A23187 (5 x 10(-6) M), in the presence of a Ca channel blocker, was relaxed by high concentrations of thiamylal (3 x 10(-4) M to 10(-3) M) and pentobarbital (10(-3) M). It is concluded that thiamylal inhibits contraction through an intracellular action as well as a Ca channel-blocking action in vascular smooth muscle of rat aorta. However, the intracellular action of pentobarbital is less potent than that of thiamylal.

Journal Article↗
PubMed1991

The vasodilator effect of thiamylal in dog mesenteric artery: contribution of intracellular action.

The effects of thiamylal on contractions induced by various mechanisms were investigated in mesenteric arteries isolated from dogs. Thiamylal (10(-4) to 10(-3) M) significantly inhibited contractions induced by KCl (20 mM) in normal media, and those induced by norepinephrine (10(-5) M) in normal and Ca(2+)-free media. Caffeine-induced contraction was significantly inhibited by thiamylal in the concentrations greater than 3 x 10(-5) M in intact fibers and 10(-5) M in chemically skinned fibers. Chemically skinned fibers that were precontracted with Ca2+ were relaxed by thiamylal in concentrations lower than those required to relax intact fibers that were precontracted with KCl (20 mM); the ED50 was 1.52 x 10(-5) M in skinned fibers and 5.50 x 10(-4) M in intact fibers. These results suggest that intracellular mechanisms are involved in thiamylal-induced vasodilatation of dog mesenteric artery.

Animals↗
PubMed1991

Halothane-induced relaxation of vascular smooth muscle: a possible contribution of increased cyclic GMP formation.

Halothane (0.75 to 2.25%) dose-dependently relaxed the vascular smooth muscle of endothelium-denuded rat aortae previously contracted with KCl, and the relaxing effect was not significantly affected by indomethacin nor dexamethasone, but partly inhibited by methylene blue. The cyclic GMP levels were increased by treatment with halothane (2.25%). It was suggested that halothane-induced relaxation of vascular smooth muscle is partly mediated by cyclic GMP formation.

Animals↗
PubMed1991

[The effect of intravenous injection of isosorbide dinitrate on the hypertension during general anesthesia: a multi-center controlled study].

The antihypertensive effect of intravenous injection of isosorbide dinitrate (ISDN) was evaluated in 137 patients undergoing elective surgery during general anesthesia [neuroleptanesthesia (NLA) or enflurane-nitrous oxide-oxygen-anesthesia (GOE)]. ISDN in dose of 20 micrograms.kg-1 or 40 micrograms.kg-1 was given as a bolus injection in 30 sec. ISDN produced a significant decrease in arterial pressure and central venous pressure; the maximum decrease was observed in 7 min after administration of ISDN. The antihypertensive effect of ISDN was dose-dependent, but there was no significant difference between two groups of patients given 20 or 40 micrograms.kg-1, or between those anesthetized with NLA or GOE. ISDN did not significantly alter heart rate, thereby causing a significant decrease in rate pressure product which reflects myocardial oxygen demand. The results suggest that a bolus injection of ISDN is a simple, practical and effective means of controlling hypertension during general anesthesia.

Adult↗