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Biomedical subjects

A Shigematsu

Publications and source records attributed to A Shigematsu.

At least 19 recordsLinked to original sources
PubMed2002

Positive pressure ventilation during fibreoptic intubation: comparison of the laryngeal mask airway, intubating laryngeal mask and endoscopy mask techniques.

BACKGROUND: The efficacy of delivery of mechanical ventilation through different airway devices during fibreoptic intubation is not known. METHODS: We compared the laryngeal mask airway (LMA), intubating laryngeal mask (ILM) and endoscopy mask for positive pressure ventilation (PPV) during fibreoptic intubation. In 80 adult paralysed patients, fibreoptic intubation was performed during PPV using a combination of a size 3 or 4 LMA with a 6.0 mm nasal RAE tracheal tube (LMA3/4 group; n=22), a size 5 LMA with a 7.0 mm nasal RAE tube (LMA5 group; n=18), an ILM with an 8.0 mm special reinforced tracheal tube (ILM group; n=20) or an endoscopy mask (Patil mask) with a 7.5 mm standard tracheal tube (Patil group; n=20). The inspiratory and expiratory tidal volumes (VI and VE) with a ventilation pressure of 20 cm H2O were measured using a pneumotachograph. RESULTS: Mean VE values during fibreoptic intubation in the LMA5 [5.3 (SD 1.5) ml kg(-1)] and ILM [7.1 (2.3) ml kg(-1)] groups were greater than in the LMA3/4 group [2.6 (1.0) ml kg(-1), P<0.0001]. The mean VE was greater in the Patil group [20.6 (4.9) ml kg(-1)] than in the other three groups (P<0.0001). Gastric insufflation during intubation was more frequent in the Patil group (30%) than in the other three groups (4.5-5.6%) (P<0.05). CONCLUSION: PPV is possible with the LMA, ILM or endoscopy mask during fibreoptic intubation. With an airway pressure of 20 cm H2O, ventilation during intubation using a size 3 or 4 LMA was almost insufficient, while ventilation using a size 5 LMA or an ILM was almost acceptable. Ventilation during intubation with the endoscopy mask was greater than that with the LMA or ILM, but gastric insufflation was more frequent.

Adult↗
PubMed2001

[Results of treatment of out-of-hospital cardiopulmonary arrest patients transferred to the UOEH hospital].

We have accepted patients suffering out-of-hospital cardiopulmonary arrest (CPA) since September 1997. In this study, we retrospectively reviewed the etiology of CPA and the outcome of the patients. We also investigated the effects of the pre-hospital cardiopulmonary resuscitation (CPR) by a bystander or emergency life-saving technicians (ELST) on the restoration of spontaneous circulation. Seventy-seven patients were transferred to our hospital from September 1997 to April 2000, 10 of who underwent bystander (basic) CPR. All the patients underwent advanced CPR by the attending physician immediately after admission to the emergency room. The etiology of CPA was categorized into three groups: (1) unknown endogenous disease (43 patients, 56%), (2) exacerbation of previous disease such as heart, respiratory or cerebrovascular disease (12 patients, 15%), (3) accident or suicide (22 patients, 29%). Spontaneous circulation of 30 patients was restored temporary, but only two patients recovered fully and were discharged from the hospital. The rate of restored spontaneous circulation of the CPA patients with bystander CPR was higher compared to that of the CPA patients without bystander CPR. The two fully recovered patients underwent bystander CPR. The CPR by ELST did not affect the resuscitated rate significantly. These results indicate that the most common etiology of CPA is unknown endogenous disease, and the rate of full recovery is very low (2.6%). This study suggests that bystander CPR may contribute to an improved outcome of the patients suffering out-of-hospital CPA.

Adolescent↗
PubMed2001

Ketamine isomers suppress superantigen-induced proinflammatory cytokine production in human whole blood.

PURPOSE: To investigate the efficacy of S(+)-ketamine and R(-)-ketamine on staphylococcal enterotoxin B (SEB)-induced tumour necrosis factor (TNF)-, interleukin (IL)-6, and IL-8 production in human whole blood in vitro. METHODS: After Ethics Committee approval and informed consent, blood samples were obtained from ten healthy volunteers and diluted with five volumes of RPMI 1640. After adding different doses of ketamine isomers (0-1000 microM), the blood was stimulated with SEB (10 ng x mL(-1)). After a six-hour incubation period, the plasma TNF- activity was determined by the L929 cell cytotoxic assay and IL-6 and IL-8 concentrations were measured using an enzyme-linked immunoassay. RESULTS: Ketamine isomers significantly suppressed SEB-induced TNF- production at concentrations exceeding 50 microM. Ketamine isomers at concentrations exceeding 100 microM also significantly suppressed SEB-induced IL-6 production. Furthermore, ketamine isomers at concentrations exceeding 500 microM significantly suppressed SEB-induced IL-8 production. There were no significant differences between the suppressive effects of S(+)-ketamine and R(-)-ketamine on SEB-induced proinflammatory cytokine production. CONCLUSION: This study demonstrated that ketamine isomers suppressed SEB-induced TNF-, IL-6, and IL-8 production in human whole blood.

Anesthetics, Dissociative↗
PubMed2001

Transdermal ketoprofen mitigates the severity of postoperative sore throat : [Le kétoprofène transdermique réduit le mal de gorge postopératoire].

PURPOSE: To evaluate prospectively the incidence and severity of postoperative sore throat in 63 orotracheally intubated patients undergoing general anesthesia for various surgical procedures and to determine whether postoperative sore throat could be attenuated by treatment with the transdermal nonsteroidal anti-inflammatory drug ketoprofen applied on the anterior skin of the neck during operation. METHOD: Patients were randomly assigned to have treatment with ketoprofen (ketoprofen group) or to have placebo tape treatment (control group). Postoperative analgesia was obtained by continuous epidural infusion of local anesthetics, and no narcotics were administered intraoperatively or postoperatively. All patients were interviewed postoperatively after 12-20 hr using a scoring scale questionnaire. Sore throat was scored as 0=no sore throat, 1=minimal, 2=mild, 3=moderate, 4=severe. RESULTS: In the control group, 16 of 32 patients had a sore throat. In the ketoprofen group, less patients (ten of 31 patients) had a sore throat (not significant). The severity of sore throat was alleviated significantly in the ketoprofen group (P <0.05). CONCLUSION: This study suggests the pain caused by tracheal intubation is relieved by intraoperative topical use of transdermal ketoprofen.

Administration, Cutaneous↗
PubMed2001

Comparison of no airway device, the Guedel-type airway and the Cuffed Oropharyngeal Airway with mask ventilation during manual in-line stabilization.

STUDY OBJECTIVE: To compare two different types of oropharyngeal airway: the Guedel-type oral airway and the Cuffed Oropharyngeal Airway (COPA), with respect to the effectiveness of positive-pressure ventilation (PPV) through a face mask in patients with in-line stabilization of the head and neck. DESIGN: Prospective, randomized, crossover study. SETTING: University hospital. PATIENTS: 30 ASA physical status I and II patients undergoing elective surgery. INTERVENTIONS: General anesthesia was induced with propofol and muscle relaxation was produced with vecuronium. In a random sequence, no airway device, the Guedel-type airway, and the COPA were used in each patient while applying a face mask and lifting the jaw forward. MEASUREMENTS AND MAIN RESULTS: Tidal volumes were measured during PPV in each option. The position of the distal tip of each airway was assessed using a fiberscope, and the resulting views were graded and compared. When the Guedel-type airway was used, tidal volumes (V(T)s; means +/- SD) were significantly greater (12.3 +/- 4.5 mL/kg) than those with no airway device (8.5 +/- 4.5 mL/kg) (p < 0.001). When the COPA was used, V(T)s (14.6 +/- 4.4 mL/kg) were significantly greater than those with the Guedel-type airway (p < 0.05). The grade of the fiberscopic view through the distal tip was significantly better with the COPA than with the Guedel-type airway (p < 0.05). CONCLUSIONS: Although clinical differences often appear trivial, the COPA is more effective on mask ventilation than the Guedel-type airway when used in patients with manual in-line stabilization.

Adult↗
PubMed2001

Surgical stress induces endotoxin hyporesponsiveness and an early decrease of monocyte mCD14 and HLA-DR expression during surgery.

UNLABELLED: It is generally accepted that major surgery is associated with severe alterations of the host-defense mechanisms. We investigated the effect of surgical stress on the immune system. Specifically, we studied the relationship between perioperative lipopolysaccharide (LPS) hyporesponsiveness and monocyte human leukocyte antigen-DR (HLA-DR) and CD14 expression during the perioperative period in 20 patients who underwent partial gastrectomy. This study demonstrated that surgical stress rapidly depressed monocyte mCD14 and HLA-DR expression in comparison with preanesthesia levels. Monocyte mCD14 expression recovered to preoperative levels on the first postoperative day, and monocyte HLA-DR expression recovered by the seventh postoperative day. Consistent with our previous study, LPS-induced tumor necrosis factor (TNF)-alpha production ex vivo was significantly suppressed from the beginning of the operation. On the contrary, the plasma interleukin-10 concentration started to increase after the surgical incision was made. LPS hyporesponsiveness was least at the end of the operation and returned to preoperative levels on the first postoperative day. In conclusion, the present study demonstrated that LPS responsiveness, plasma interleukin-10 concentration, and monocytes mCD14 and HLA-DR expression altered from the early period of surgery. These alterations may be related to the impairment of the immune system during the perioperative period. IMPLICATIONS: Recent studies demonstrate that surgical stress induces immune dysfunction. We found that surgical stress rapidly decreased monocyte mCD14 and human leukocyte antigen-DR expression, and endotoxin responsiveness. These findings suggest that early changes of the immune system caused by surgical stress contribute to postoperative complications such as sepsis and multiple organ failure.

Gastrectomy↗
PubMed2001

The influence of the laryngeal mask airway on the shape of the submandibular gland.

UNLABELLED: Although transient sialadenopathy of the submandibular gland associated with insertion of the laryngeal mask airway (LMA) has been described, the influence of the LMA on the submandibular gland is unknown. We measured the width and length of the submandibular glands by using ultrasonography in patients in whom the LMA was used. An increased intracuff pressure of the LMA, up to 150 cm H2O, was used in a prospective study of adult patients scheduled for elective surgery. The width of the gland increased with an increasing intracuff pressure from 50 to 100 cm H2O (P < 0.01) and 100 to 150 cm H2O (P < 0.01) but did not change from 0 to 50 cm H2O. There was no change in the length of the gland. We conclude that the submandibular gland was deformed by the insertion of the LMA. IMPLICATIONS: The findings in our study show that the submandibular triangle can be easily compressed by the insertion of the laryngeal mask airway (LMA). When inserting the LMA, it is important to consider that the LMA cuff may alter these tissues, which are situated between the lingual root and the submandibular triangle.

Adult↗
PubMed2001

Inhibitory effects of nicorandil on rat mesangial cell proliferation via the protein kinase G pathway.

We investigated the effects of nicorandil, which is a hybrid between a nitrate and an ATP-sensitive potassium channel (K(ATP)) opener, on cultured rat mesangial cell proliferation. Nicorandil (1 microM to 1 mM inhibited [(3)H]thymidine incorporation into rat mesangial cells in a concentration-dependent manner. Nicorandil (1 microM to 1 mM) also inhibited the number of cells. Nicorandil increased cyclic guanosine 3',5'-cyclic monophosphate accumulation in mesangial cells. A protein kinase G inhibitor, KT5823, partially eliminated the inhibition of mesangial cell proliferation by nicorandil. Methylene blue, a guanylate cyclase inhibitor, blocked the inhibitory effect of nicorandil on mesangial cell proliferation. We also examined the effects of K(ATP) mediators. Cromakalim, a K(ATP) activator, and glibenclamide, a K(ATP) inhibitor, had little effect on the proliferation of mesangial cells. These results suggest that the inhibitory effects of nicorandil on mesangial cell proliferation are mediated via the protein kinase G pathway.

Alkaloids↗
PubMed2001

Adrenomedullin inhibits the pressor effects and decrease in renal blood flow induced by norepinephrine or angiotensin II in anesthetized rats.

Adrenomedullin (AM), a hypotensive peptide originally isolated from human pheochromocytoma, has been reported to regulate renal functions. In patients with glomerulonephritis, the serum levels of AM are elevated as well as hypertensive agents norepinephrine (NE) and angiotensin II (AII). The effects of AM on the NE- or AII-induced pressor effects and renal blood flow responses, however, are not well clarified. We examined the effects of AM on blood pressure and renal blood flow induced by NE or AII in anesthetized rats. Arterial blood pressure and renal blood flow were measured using a calibrated pressure transducer and a laser Doppler flowmeter, respectively. Drugs were injected into the tail vein with a syringe. Intravenous administration of AM (1-3 nmol/kg) decreased the arterial blood pressure in anesthetized rats in a dose-dependent manner, whereas it did not affect the renal blood flow. NE or AII administration in anesthetized rats caused both increases in blood pressure and decreases in renal blood flow. Simultaneous administration of AM with NE or All prevented the increasing effects of blood pressure and inhibited the decreases in renal blood flow caused by NE or AII. These findings suggest that AM may have a protective role against the pressor effects and decrease in renal blood flow caused by NE or AII.

Adrenomedullin↗
PubMed2001

A possible relationship between abortions and placental embolism in pregnant rabbits given human granulocyte colony-stimulating factor.

Developmental toxicity studies were conducted in rats and rabbits with a human G-CSF derivative (NTG). As reported for G-CSF, increases in abortions and fetal mortality were observed in rabbits, but not in rats given NTG. Histopathological examination of the rabbit placenta revealed accumulation of neutrophils in vessels and necrosis of the tissues surrounding these vessels. To assess the mechanism of abortion and fetal death in rabbits given G-CSF, 125I-labeled NTG was given intravenously on Day 18 of pregnancy after repeated administration of cold NTG on Days 6 through 17 of pregnancy, and the feto-maternal distribution of radioactivity was examined. In a rabbit given 20 micrograms/kg, high radioactivity was observed in the endometrium, placenta, and some parts of the decidua at 6 hr when the concentration of radioactivity in maternal blood had already decreased. At 24 hr after administration of 200 micrograms/kg NTG, high radioactivity was still detected in parts of the maternal placenta. These patterns of distribution suggest that embolism occurred in parts of the uterus and placenta which might have caused congestion. Radioactivity in the TCA precipitates in the fetus was low, suggesting that NTG does not readily transfer to the fetus. These results strongly suggest that neutrophils accumulated in the vessels of placenta and induced embolism leading to abortions and fetal mortality in the rabbits given G-CSF.

Absorption↗
PubMed2001

[Anesthesia for patients with unexpected pulmonary embolisms due to a large abdominal tumor obstructing with inferior vena cava].

Several reports have highlighted the risk of pulmonary embolisms during the preoperative period in patients with large abdominal tumors obstructing the inferior vena cava. We describe a patient who developed pulmonary embolism just before surgery. A 68[correction of 64]-year-old female was scheduled to undergo elective resection of a large abdominal tumor under general anesthesia. She had no signs of deep venous thrombosis, but on the day of the operation, pulmonary embolism developed suddenly. Anticoagulant therapy was performed. Capnography and pulmonary artery pressure were monitored during the perioperative period to detect the recurrence of pulmonary embolism. The percutaneous cardio-pulmonary support (PCPS) was also prepared. The operation was performed successfully. In this patient, the pulmonary embolism occurred suddenly during the preoperative period, even though we had ruled out the existence of deep venous thrombosis. This case report emphasizes the risk of pulmonary embolism in any patient with a large abdominal tumor obstructing the inferior vena cava. This case of a large abdominal tumor suggests that capnography, monitoring of pulmonary artery pressure and preparation of a PCPS in case of pulmonary embolism during surgery are necessary even in patients without signs of deep venous thrombosis.

Abdominal Neoplasms↗
PubMed2001

[Anesthesia using propofol for a patient with arthrogryposis multiplex congenita].

Arthrogryposis multiplex congenita (AMC) is a syndrome with multiple persistent limb contractures, often accompanied by associated anomalies. Pediatric patients with AMC frequently require operations, necessitating general endotracheal anesthesia. We report on the anesthesia used for a 14-year-old male with AMC, who required the surgical removal of soft tissue from both hip joints. We used propofol and vecuronium bromide to induce anesthesia, and maintained anesthesia with 40% nitrous oxide, oxygen, and propofol at 6 mg.kg-1.1 hr-1. Both induction and maintenance were smooth, and no hyperthermia occurred perioperatively. Propofol can be safely used for anesthesia in AMC patients.

Adolescent↗
PubMed2001

[Difficult ventilation during induction of anesthesia in a patient with Arnold-Chiari malformation type II].

Arnold-Chiari malformation is a congenital disorder with caudal displacement of the cerebellar tonsils through the foramen magnum into the cervical canal. We report difficulty with ventilation during the induction of anesthesia due to apnea and laryngospasm in a 5-year-old female with Arnold-Chiari malformation type II diagnosed at birth. She had had short periods of apnea during infancy, but was asymptomatic recently. Slow induction of anesthesia was performed using sevoflurane, but just after induction, the patient developed apnea and we could not ventilate her due to laryngospasm. We woke her up, and induced anesthesia with barbiturates. The operation was performed without complications, but she had another apnea attack with laryngospasm at extubation. This case suggests that it is important to be aware of the possibility of apnea due to disorder of the respiratory center in patients with Arnold-Chiari deformity.

Anesthesia, Inhalation↗
PubMed2001

Inhibition by tramadol of muscarinic receptor-induced responses in cultured adrenal medullary cells and in Xenopus laevis oocytes expressing cloned M1 receptors.

Tramadol is a widely used, centrally acting analgesic, but its mechanisms of action are not completely understood. Muscarinic receptors are known to be involved in neuronal function in the brain and autonomic nervous system, and much attention has been paid to these receptors as targets of analgesic drugs in the central nervous system. This study investigated the effects of tramadol on muscarinic receptors by using two different systems, i.e., a Xenopus laevis oocyte expression system and cultured bovine adrenal medullary cells. Tramadol (10 nM-100 microM) inhibited acetylcholine-induced currents in oocytes expressing the M1 receptor. Although GF109203X, a protein kinase C inhibitor, increased the basal current, it had little effect on the inhibition of acetylcholine-induced currents by tramadol. On the other hand, tramadol did not inhibit the current induced by AlF4-, a direct activator of GTP-binding protein. In cultured bovine adrenal medullary cells, tramadol (100 nM-100 microM) suppressed muscarine-induced cyclic GMP accumulation. Moreover, tramadol inhibited the specific binding of [3H]quinuclidinyl benzilate (QNB). Scatchard analysis showed that tramadol increases the apparent dissociation constant (Kd) value without changing the maximal binding (Bmax), indicating competitive inhibition. These findings suggest that tramadol at clinically relevant concentrations inhibits muscarinic receptor function via QNB-binding sites. This may explain the neuronal function and anticholinergic effect of tramadol.

Acetylcholine↗