Search PubMed⌕ Search

Biomedical subjects

Y Inagaki

Publications and source records attributed to Y Inagaki.

At least 91 records · Page 5Linked to original sources
PubMed1997

Effects of vasodilators guanethidine, nicardipine, nitroglycerin, and prostaglandin E1 on primary afferent nociceptors in humans.

Although vasodilator agents have been used to alleviate the pain of complex regional pain syndromes, the precise mechanism of pain relief is not well known. In this study the effects of various kinds of vasodilators on primary afferent nociceptors were investigated by measuring the thermal pain threshold. Evaluated in the study were the effects of guanethidine (2 mg/mL), nicardipine (0.2 mg/mL). Nitroglycerin (0.3 mg/mL), and prostaglandin E1 (1 microgram/mL) on the cutaneous pain threshold and blood flow at 7-day intervals in six healthy volunteers. Each aliquot of 0.5 mL of the test vasodilator or lidocaine (10 mg/mL) and saline (control) were intradermally injected at three sites each on both forearms. The pricking-pain threshold and skin tissue blood flow were determined using a radiant heat-stimulating system and a laser-Doppler tissue-blood flowmeter, respectively. The pain threshold increased with lidocaine, guanethidine, and nicardipine; remained unchanged with Nitroglycerin; but decreased with prostaglandin E1. In contrast, the skin tissue blood flow increased by four to nine times with all vasodilators. These results indicate that the effect of vasodilators on primary afferent nociceptors is not related to the vasodilating effect and may not involve a common mechanism of action for pain relief in complex regional pain syndromes.

Adult↗
PubMed1997

Use of a deviant mitochondrial genetic code in yellow-green algae as a landmark for segregating members within the phylum.

Several algae that were previously classified in the phylum Xanthophyta (yellow-green algae) were assigned in 1971 to a new phylum, Eustigmatophyta. It was anticipated that the number of algae reclassified to Eustigmatophyta would increase. However, due to the fact that the morphological characteristics that segregate eustigmatophytes from other closely related algae can be only obtained through laborious electron microscopic techniques, the number of members in this phylum have increased rather slowly. We attempted, therefore, to segregate two closely related groups of algae, eustigmatophytes and yellow-green algae, on the basis of a molecular phylogenetic tree as a means of providing an alternative method of distinguishing these phyla. We analyzed the mitochondrial cytochrome oxidase subunit I (COXI) gene sequences of eight algae classified as xanthophyceans and found that six manifested the expected deviant genetic code where AUA codes for methionine (AUA/Met), but not for isoleucine (AUA/Ile) as in the universal genetic code. The other two, Monodus sp. (CCMP 505) and Ophiocytium majus (CCAP 855/1), which were presumed to be yellow-green algae, and all the examined eustigmatophytes utilized AUA for Ile. In addition, the phylogenetic tree of COXI gene sequences showed that the six yellow-green algae bearing the AUA/Met deviant code composed a tight clade with a bootstrap value of 100%. The phylogenetic tree of the corresponding sequences from Monodus sp. and Ophiocytium majus and the eustigmatophytes also composed a tight cluster, but with a bootstrap value of 92%. These results strongly suggest that two previously classified members of yellow-green algae belong to the phylum Eustigmatophyta. Therefore, examination of the mitochondrial genetic code in algae appears to be a potentially very useful genetic marker for classifying these organisms, especially when it is considered with the results obtained through a molecular phylogenetic tree.

DNA, Mitochondrial↗
PubMed1997

Algae or protozoa: phylogenetic position of euglenophytes and dinoflagellates as inferred from mitochondrial sequences.

The chloroplasts of euglenophytes and dinoflagellates have been suggested to be the vestiges of endosymbiotic algae acquired during the process of evolution. However, the evolutionary positions of these organisms are still inconclusive, and they have been tentatively classified as both algae and protozoa. A representative gene of the mitochondrial genome, cytochrome oxidase subunit I (coxI), was chosen and sequenced to clarify the phylogenetic positions of four dinoflagellates, two euglenophytes and one apicomplexan protist. This is the first report of mitochondrial DNA sequences for dinoflagellates and euglenophytes. Our COXI tree shows clearly that dinoflagellates are closely linked to apicomplexan parasites but not with algae. Euglenophytes and algae appear to be only remotely related, with euglenophytes sharing a possible evolutionary link with kinetoplastids. The COXI tree is in general agreement with the tree based on the nuclear encoded small subunit of ribosomal RNA (SSU rRNA) genes, but conflicts with that based on plastid genes. These results support the interpretation that chloroplasts present in euglenophytes and dinoflagellates were captured from algae through endosymbioses, while their mitochondria were inherited from the host cell. We suggest that dinoflagellates and euglenophytes were originally heterotrophic protists and that their chloroplasts are remnants of endosymbiotic algae.

Animals↗
PubMed1997

A deviant mitochondrial genetic code in prymnesiophytes (yellow-algae): UGA codon for tryptophan.

The sequence of a representative mitochondrial gene COXI, encoding cytochrome c oxidase subunit I, was determined in five species that cover all the orders of the Prymnesiophyta with the exception of the Pavlovales. Through this analysis, we noticed that the 'stop' codon UGA appears frequently and, specifically, at conserved tryptophan (Trp) sites of the gene. We showed these sites were not edited in the corresponding mRNA in one of these species, Isochrysis galbana. Therefore, it is most likely that the UGA codon is used for Trp, and not as a stop codon, in prymnesiophytes. All the analyzed prymnesiophytes made a tight cluster on the COXI phylogenetic tree which includes representative species of green-algae, land plants, yellow-green algae, eustigmatophytes and a red-alga. This suggests a monophyletic origin for the prymnesiophytes. The same deviant genetic code, i.e. UGA for Trp, has also been found in the red-alga, Chondrus crispus. In spite of the fact that this red-alga and the prymnesiophytes, share the same deviant genetic code for Trp, close affinity between the two groups was not statistically supported by the phylogenetic analysis of COXI sequences.

Base Sequence↗
PubMed1997

Serotyping of Streptococcus pyogenes isolated from common and severe invasive infections in Japan, 1990-5: implication of the T3 serotype strain-expansion in TSLS. The Working Group for Group A Streptococci in Japan.

To clarify the relationship between the epidemics of severe invasive group A streptococcal infections (streptococcal Toxic Shock-Like Syndrome: TSLS) and common group A streptococcal infections in Japan, we examined the T serotypes of S. pyogenes strains (group A streptococci) isolated from clinical specimens of the streptococcal infections (17999 cases) in the period 1990-5, including the severe infections (TSLS) (29 cases) in the period 1992-5. Characteristic points of the analyses were: (1) dominant serotypes of the infections in these periods were T12, T4, T1, T28 and TB3264, which were consistently isolated; (2) isolates of T3 rapidly increased through 1990 to 1994 while T6 decreased in the period 1990-3; (3) when Japanese area was divided into three parts, T3 serotype tended to spread out from the north-eastern to the south-western area; (4) strains of T3 and T1 serotypes were dominant in the TSLS. Dominant-serotype strains of streptococcal infections did not always induce severe infections and dominance of T3 serotype in the TSLS seemed to be correlated with the increase of T3 in streptococcal infections. These results may indicate that certain clones of S. pyogenes are involved in the pathogenesis of the TSLS.

Adolescent↗
PubMed1997

The gene encoding flavanone 3-hydroxylase is expressed normally in the pale yellow flowers of the Japanese morning glory carrying the speckled mutation which produce neither flavonol nor anthocyanin but accumulate chalcone, aurone and flavanone.

The Japanese morning glory carrying the recessive mutable speckled allele with the dominant speckled-activator bears colorless flowers with fine and round colored spots distributed over the corolla whereas the plant without the speckled-activator produces pale yellow flowers. Previous chemical analysis has indicated that a mutation in the gene for flavanone 3-hydroxylase (F3H) is a likely candidate for the speckled allele. However, the F3H mRNA without sequence alteration accumulates normally in the pale yellow flowers, indicating that the speckled allele is neither the F3H gene nor a regulatory gene acting on the F3H gene expression.

Amino Acid Sequence↗
PubMed1997

Effects of epidural and intravenous buprenorphine on halothane minimum alveolar anesthetic concentration and hemodynamic responses.

There is limited information regarding the effects of epidural or intravenous (i.v.) buprenorphine on minimum alveolar anesthetic concentration (MAC) of volatile anesthetic and hemodynamic responses to tracheal intubation and surgical incision. This study was conducted to find the effects of i.v. and epidural buprenorphine required for postoperative pain relief on halothane MAC and hemodynamic responses to tracheal intubation and surgical incision in 126 female patients. Patients were randomly assigned to the four groups: Group I received i.v. and epidural saline as a control; Group II was given buprenorphine 4 micrograms/kg i.v.; and Groups III and IV received buprenorphine 2 and 4 micrograms/kg epidurally, respectively. Groups II-IV were divided into the two subgroups according to the timing of administration, either at induction of anesthesia in the operating room (OR) (OR group) or 90 min before anesthetic induction in the ward (Ward group). Anesthesia was induced with only halothane in oxygen, and the trachea was intubated without other drugs. Halothane MAC was determined by logistic regression analysis and the Dixon up-and-down method. Halothane MAC in the seven study groups was as follows: 0.75% +/- 0.05% (mean +/- SE) in Group I; 0.49% +/- 0.03% and 0.59% +/- 0.04%, respectively, in Groups II OR and Ward; 0.65% +/- 0.003% and 0.49% +/- 0.07%, respectively, in Groups III OR and Ward; and 0.51% +/- 0.07% and 0.37% +/- 0.02%, respectively, in Groups IV OR and Ward. Halothane MAC decreased significantly (P < 0.05) in groups that received buprenorphine except Group III-OR compared with Group I. Systolic blood pressure did not change significantly in Groups II-OR and IV-OR after tracheal intubation and in Group III-Ward and IV-Ward after surgical incision but increased significantly (P < 0.05) in the remaining groups in response to noxious stimuli. Heart rate responses to tracheal intubation and surgical incision were similar to those in systolic blood pressure. These results indicate that preanesthetic administration of epidural or IV buprenorphine required for postoperative analgesia reduces halothane MAC and attenuates hemodynamic responses to tracheal intubation and surgical incision according to the dose, route, and timing of administration.

Adult↗
PubMed1997

Laser Doppler skin blood flow and sympathetic nervous responses to surgical incision during halothane and isoflurane anesthesia.

The aim of the present study was to evaluate whether a sudden decrease in skin blood flow measured using a laser Doppler velocimeter reflects sympathetic nervous response to surgical skin incision during halothane (n = 17) and isoflurane (n = 16) anesthesia in 33 ASA physical status I or II patients scheduled for laparotomy. Plasma norepinephrine concentrations in the responding patients who showed a sudden decrease in the skin blood flow after surgical incision increased significantly and continued to increase 1-10 min after skin incision under halothane and isoflurane anesthesia. Although plasma norepinephrine concentrations in the nonresponders did not increase after surgical incision with halothane, the concentrations increased significantly at 1 min, but not at 3 and 10 min, after skin incision with isoflurane. The results indicate that the sudden decrease in laser Doppler flow reflects the sympathetic response to surgical incision. However, these also suggest that the factors that control the skin blood flow may not be simply sympathetic but may reflect other modulators as well. Plasma epinephrine concentration increased during skin incision, but the concentrations did not differ between the patients with and without a sudden decrease in skin blood flow. Increases in systolic blood pressure and rate-pressure product on skin incision were also significantly more in patients with skin blood flow response compared with those without the response. The magnitude of changes in plasma norepinephrine concentration and hemodynamic variables with skin incision was greater with isoflurane than with halothane at the same minimum alveolar anesthetic concentration level.

Adult↗
PubMed1997

The effects of epidural fentanyl on hemodynamic responses during emergence from isoflurane anesthesia and tracheal extubation: a comparison with intravenous fentanyl.

To investigate the effects of epidural fentanyl infusion on hemodynamic responses to recovery of consciousness and tracheal extubation, we studied 50 unpremedicated patients scheduled for abdominal hysterectomy. All patients underwent epidural catheterization and blind infusion of placebo and study drug. Patients were assigned randomly to three groups: Group I received epidural and intravenous (i.v.) bolus injections and infusion of saline at the rate of 0.2 mL x kg(-1) x h(-1); Group II received an i.v. injection of fentanyl 2 microg/kg for 30 s followed by 25 ng x kg(-1) x min(-1), and Group III received epidural injection and infusion using the same administration regimen as Group II. Anesthesia was induced with and maintained by isoflurane alone in an air-oxygen mixture. The study drug was administered at the start of retroperitoneal suturing. Hemodynamic variables, including systolic and diastolic arterial pressures (SAP and DAP, respectively) and heart rate (HR), were recorded every minute between the start of administration of the study and 5 min after tracheal extubation. During emergence from anesthesia and tracheal extubation, the increases in SAP, DAP, and HR in Groups II and III were significantly diminished (P < 0.05) compared with those in Group I. Arterial pressures, but not HR, were attenuated more significantly in Group III than in Group II during and after tracheal extubation, although the plasma fentanyl concentration was significantly lower (P < 0.01) in Group III (0.64 +/- 0.03 ng/ mL, [mean +/- SD]) than in Group II (1.15 +/- 0.09 ng/mL). The incidence of coughing during and after extubation was also lower with Group III. Suppression of respiratory rate prior to tracheal extubation was similar in the two groups receiving fentanyl. These findings suggest that the significant reduction in arterial pressures responses to tracheal extubation due to epidural fentanyl infusion may arise from more suppression of cough reflex than i.v. fentanyl infusion, which could be provided by the spinal action of epidural fentanyl as well as the supraspinal action.

Adjuvants, Anesthesia↗
PubMed1997

Use of the laryngeal mask airway as an alternative to the tracheal tube during ambulatory anesthesia.

UNLABELLED: We designed a prospective, randomized, multicenter study to compare anesthetic requirements, recovery times, and postoperative side effects when a laryngeal mask airway (LMA) was used as an alternative to the tracheal tube (TT) during ambulatory anesthesia. After induction of anesthesia with midazolam 2 mg, fentanyl 1 microg/kg, and propofol 2 mg/kg, 381 patients were randomly assigned to receive either an LMA (n = 207) or TT (n = 174) for airway management. In patients assigned to the TT group, succinylcholine 1 mg/kg or a nondepolarizing muscle relaxant was administered to facilitate tracheal intubation. Anesthesia was maintained with volatile anesthetics in combination with nitrous oxide 60% and oxygen. The average time to placement of the two airway devices (5 min) and the failure rates (1%) were similar in the two groups. Although there was a significant decrease in the intraoperative fentanyl requirement in the LMA group, the difference was of little clinical significance. Furthermore, there were no differences in the volatile anesthetic requirements. The time from end of surgery to removal of the airway device (5 min) was also similar in the two study groups. Although duration of the postanesthesia care unit stay and time to ambulation were significantly shorter in the LMA group, there were no differences in the times to "home readiness." The incidence of nausea and vomiting and the need for rescue antiemetic treatments in the postoperative period were similar in the two airway management groups. However, the incidence of postoperative sore throat was significantly greater in patients receiving the TT (versus the LMA). In conclusion, this study suggests that the LMA is a useful alternative to the TT for airway management during ambulatory anesthesia. IMPLICATIONS: Use of the laryngeal mask airway can obviate the need for insertion of a tracheal tube for many ambulatory surgery procedures, and thereby decrease the incidence of postoperative sore throats.

Adult↗
PubMed1997

A comparative study of the antinociceptive action of xenon and nitrous oxide in rats.

UNLABELLED: We attempted to clarify the mechanism of antinociceptive action induced by xenon and nitrous oxide. Eighty percent of nitrous oxide or 80% xenon was applied to rats inside enclosed clear plastic glass cylinders with their tails protruding for assessment of the tail-flick response to radiant heat. With repeated testing, there was a rapid reduction to nitrous oxide antinociception within 90 min, which was interpreted as development of tolerance, but not to xenon antinociception. Nitrous oxide antinociception was blocked by the intraperitoneal administration of 0.1 or 1.0 mg/kg yohimbine, but not by 1.0 or 5.0 mg/kg L659-066 or by 5.0 or 10 mg/kg naloxone. Xenon antinociception was not affected by any of these drugs. Yohimbine and L659-066 are characterized as alpha 2-adrenoceptor antagonists. Although yohimbine penetrates the blood-brain barrier after systemic administration, L659-066 does not penetrate it and act peripherally. Therefore, the results indicate that alpha 2-adrenoceptors, but not opioid receptors, may play a key role in antinociception induced by nitrous oxide in the central nervous system. Furthermore, the mechanism of xenon antinociception differs from that of nitrous oxide because it does not involve either alpha 2 or opioid receptors. IMPLICATIONS: The precise mechanism of antinociceptive action of nitrous oxide and xenon remains unknown. It is still controversial whether an opioid system plays a role in antinociception induced by nitrous oxide. The results of the study showed that antagonism of central alpha 2-adrenoceptors, but not opioid receptors, reverses the antinociception induced by nitrous oxide but not by xenon, which indicates that alpha 2-adrenoceptors may play a key role in nitrous oxide antinociception.

Analgesics, Non-Narcotic↗
PubMed1997

Contribution of the spinal cord to arousal from inhaled anesthesia: comparison of epidural and intravenous fentanyl on awakening concentration of isoflurane.

UNLABELLED: To investigate the contribution of modulation of afferent nociceptive inputs by an opioid in the spinal cord to arousal from inhaled anesthesia, we determined the awakening concentration of isoflurane in 50 unpremedicated patients scheduled for abdominal hysterectomy. Patients were assigned randomly to three groups. Group I received bolus injections of both epidural and intravenous (I.V.) saline, followed by both epidural and I.V. infusions at the rate of 0.2 mL x kg(-1) h(-1). Group II received an I.V. injection of fentanyl 2 microg/kg, followed by an infusion at the rate of 25 ng x kg(-1) x min(-1), and Group III received an epidural injection and infusion in the same administration regimen as Group II. Anesthesia was induced with and maintained by isoflurane in an air/oxygen mixture (fraction of inspired oxygen = 0.5) with no adjuvant drugs. The study drug was administered at the start of retroperitoneal suturing. The awakening concentrations of isoflurane in Groups I, II, and III (mean +/- SD) were 0.32% +/- 0.07%, 0.31% +/- 0.06%, and 0.24% +/- 0.06%, respectively. At that time, plasma fentanyl concentrations in Groups II and III were 1.12 +/- 0.09 ng/mL and 0.65 +/- 0.04 ng/mL, respectively. Epidural fentanyl infusion reduced the awakening concentration of isoflurane more (P < 0.01) than I.V. fentanyl infusion, despite the lower plasma concentration (P < 0.01) in the epidural group. These findings suggest that epidural fentanyl delays arousal from inhaled anesthesia by modulating the afferent nociceptive inputs in the spinal cord. The spinal cord may contribute to arousal from inhaled anesthesia through the regulation of afferent inputs by opioids along with the supraspinal region of the central nervous system (CNS), even if the effects of subarachnoid fentanyl on the higher CNS via the cephalad migration is taken into consideration. IMPLICATIONS: The present study revealed that the spinal cord, the lower level of central nervous system, contributed to arousal from general anesthesia, along with the higher central nervous system, by comparing the concentrations of an inhaled anesthetic, isoflurane, in the expiration of patients receiving systemic or regional administration of an opioid, fentanyl.

Adult↗
PubMed1997

Case report: haemorrhagic colitis associated with royal jelly intake.

The case report of a 53-year-old woman with abdominal pain and bloody diarrhoea is described. Prior to the onset of symptoms the patient had taken royal jelly for 25 days. Colonoscopy revealed that the mucosa was haemorrhagic and oedematous throughout the 20 cm long sigmoid colon. Histopathologically, mucosal haemorrhage, oedema, and infiltration of inflammatory cells were observed. Transmission electron microscopic examination revealed platelet aggregation in 30% of capillaries in the mucosal lesions. The drug-induced lymphocyte stimulation test was slightly positive for royal jelly (847 c.p.m., SI = 147%) compared with the control (576 c.p.m.). The patient's signs and symptoms disappeared within a few days after the initiation of conservative therapy, and the colonic lesions disappeared after 2 weeks of this therapy. This is the first reported case of haemorrhagic colitis associated with royal jelly intake.

Colitis↗
PubMed1997

Molecular typing of enterohemorrhagic Escherichia coli O157:H7 isolates in Japan by using pulsed-field gel electrophoresis.

Pulsed-field gel electrophoresis (PFGE) was applied for molecular typing of 825 enterohemorrhagic Escherichia coli (EHEC) O157:H7 isolates, most of which were from 19 outbreaks and 608 sporadic cases in Japan, mainly in May to August 1996. By PFGE, the EHEC O157:H7 isolates were classified into six types (type I to V and ND [nondescript]) and UT untypeable isolates. Fifty isolates from seven outbreaks in May to June and 60 isolates from patients with sporadic cases of infection showed almost identical PFGE patterns which differed in only 1 of 22 DNA fragments. They were classified into type I. Ninety-nine isolates from 10 other outbreaks and 156 isolates from patients in the Kinki area with sporadic cases of infection obtained in the early summer of 1996 showed identical PFGE patterns, suggesting that they were derived from one huge outbreak. They were classified into type II. Type IV EHEC isolates, which had only the stx2 gene, caused another outbreak in a primary school in June. EHEC isolates of two other types, types III and V, were not related to the outbreak but were isolated in several parts of Japan. ND EHEC isolates included a variety of patterns which could not be classified into either of the types mentioned above. Twenty-five isolates could not be analyzed due to degradation of their genomic DNAs and were represented as UT. These results indicate that EHEC O157:H7 strains with various PFGE types have already spread to Japan and caused the multiple outbreaks and sporadic infections in Japan in the summer of 1996.

Bacterial Typing Techniques↗
PubMed1997

[Hemodynamic effects of amrinone combined with dopamine in patients undergoing living renal transplantation].

Systemic hypertension is a constant feature of chronic renal failure, mediated by renin and exacerbated by salt and fluid loading. Vascular atherosclerosis appears to accelerate in patients on long-term dialysis. Therefore, it is important to control hypertension and keep appropriate renal blood flow during living renal transplantation surgery. Amrinone, a phosphodiesterase inhibitor, produces vasodilation in arterial smooth muscle as well as venodilation in the capacitance bed. By increasing myocardial contractility it increases inotropic effect. Amrinone has potent inodilator effects because of its dual mechanism of action. The current study is aimed to compare hemodynamic effects between amrinone (3-5 mg.kg-1.min-1) (AMR group, n = 4) and nitroglycerin (0.3-1.0 mg.kg-1.min-1) (NTG group, n = 5), combined with dopamine (3-5 mg.kg-1.min-1) in nine patients undergoing living renal transplantation. Increase in cardiac index in AMR group was significantly larger than that in NTG group. Values of systemic and pulmonary vascular resistance in AMR group were significantly smaller than those in NTG group. No significant difference was found in renal function in the post-operative period.

3',5'-Cyclic-AMP Phosphodiesterases↗