Kazuo Hanaoka

Molecular Cloning and Functional Analysis of a Novel P2 Nucleotide Receptor

The cDNA encoding a novel P2 receptor was isolated from rat aortic smooth muscle cell library and functionally characterized. The cloned P2 receptor exhibits structural features characteristic of the G protein-coupled receptor family and shows 44 and 38% amino acid identity with previously cloned rat P2U and chicken P2Y receptors, respectively. The cloned P2 receptor is functionally coupled to phospholipase C but not to adenylate cyclase in C6 rat glioma cells transfected with the cloned P2 expression vector. The rank order of agonist potency as judged by intracellular Ca2+ mobilization responses is UTP > ADP = 2-methylthioATP > ADPβS > ATP = ATPγS, which is not compatible with any of the previously characterized P2 receptor subtypes. The nonselective P2 antagonists, suramin and reactive blue-2, inhibit nucleotide-induced phospholipase C activation in cells expressing the cloned P2 receptor. The cloned P2 receptor mRNA is abundantly expressed in various rat tissues including lung, stomach, intestine, spleen, mesentery, heart, and, most prominently, aorta. The results indicate that the novel metabotropic P2 receptor has pharmacological characteristics distinct from any of P2 receptor subtypes thus far identified and suggest the existence of a novel regulatory system by extracellular nucleotides of potential significance.

Analgesic requirements after major abdominal surgery are associated with OPRM1 gene polymorphism genotype and haplotype

AIMS The association between SNPs of the human OPRM1 gene encoding the micro-opioid receptor and postoperative analgesic requirements in surgical patients remains controversial. Here, we evaluate whether any of the five tag SNPs (A118G, IVS2+G691C, IVS3+G5953A, IVS3+A8449G and TAA+A2109G) representing the four linkage disequilibrium blocks of the OPRM1 gene influences postoperative analgesic requirements. MATERIALS & METHODS We studied 138 adult Japanese patients who underwent major open abdominal surgery under combined general and epidural anesthesia and received continuous postoperative epidural analgesia with opioids. RESULTS The 118G homozygous (GG) patients required 24-h postoperative analgesics more than 118A homozygous (AA) and heterozygous (AG) patients. Tag SNP haplotypes also were associated with 24-h postoperative analgesic requirements. CONCLUSIONS These results suggest that OPRM1 gene tag SNP genotypes and haplotypes can primarily contribute to prediction of postoperative analgesic requirements in individual patients undergoing major open abdominal surgery.

Changes in cerebral blood flow estimated after stellate ganglion block by single photon emission computed tomography

The validity of the hypothesis that the cerebral vasculature is under the control of sympathetic innervation was investigated using brain scintigraphy imaging before and after stellate ganglion block (SGB). The experiment with HM-PAO showed a definite increase in the blood flow of the brain on the block side on both by the dynamic images and the SPECT images. The tympanic temperature (Tty) of the block side decreased significantly after SGB, compared to the unblock side in this study, as had been reported before. This change in Tty coinsided with the increase in cerebral blood flow as mentioned above. This study demonstrated that the cerebral vasculature is under the control of sympathetic innervation, the pathway of which is relayed and/or passes through the stellate ganglion. We conclude that SGB increases intracerebral blood flow and can also exert secondary effects systemically due to CNS blood flow changes as have been previously reported.

Clinical study of OKY-046, a thromboxane synthetase inhibitor, in prevention of cerebral vasospasms and delayed cerebral ischaemic symptoms after subarachnoid haemorrhage due to aneurysmal rupture: a randomized double-blind study

A double-blind study was conducted at 48 neurosurgical services in Japan to investigate the usefulness of OKY-046, an imidazole derivative and a thromboxane synthetase inhibitor, on cerebral vasospasm and cerebral ischaemic symptoms in patients with ruptured cerebral aneurysms. OKY-046 was administered in two daily doses of 80 mg (L group) and 400 mg (H group), and compared with a group given a placebo (P group). The following results were obtained: the occurrence of cerebral vasospasm was significantly lower in the L group than in the P group; the development of low density area (LD) in CTs was significantly lower in both the L and H groups than in the P group; motor paralysis in the L group improved significantly sooner, and that in the H group tended to improve sooner than that in the P group; in subjects with severe vasospasm, the incidence of LD was significantly lower, with better functional prognosis, in the L group than in the P group; in subjects with severe grades on the Glasgow Coma Scale (GCS), Japan Coma Scale (JCS) or High Density (HD) Score the functional prognosis at 1 month after the aneurysmal rupture was significantly better in the L group than in the P group, though no significant differences were seen in the overall investigation; there were no significant differences among the three groups in the development of either laboratory-determined abnormality or of adverse reactions. It is thus concluded that OKY-046 is clinically useful at a dose of 80 mg/d for cerebral vasospasm and cerebral ischaemic symptoms after subarachnoid haemorrhage (SAH) caused by aneurysmal rupture.

Propofol-induced bronchoconstriction: two case reports.

IMPLICATIONS Bronchoconstriction was induced by anesthetic induction with propofol in two patients with allergic diseases. One had severe bronchospasm improved by epinephrine. Propofol should be used with caution in patients with allergic disease.

Molecular Cloning, mRNA Expression and Chromosomal Localization of Mouse Angiotensin-converting Enzyme-related Carboxypeptidase (mACE2)

We isolated two mouse cDNA clones which show significant similarities with human angiotensin-converting enzyme-related carboxypeptidase (ACE2). The cDNAs were 2746 and 1995 bp in length and seemed to arise from the same gene by alternative splicing. The longer cDNA encoded a 798-amino acid protein containing the sequence motif conserved among zinc metallopeptidases. Mouse ACE2 showed 83% identity with human ACE2. Northern blot analysis revealed that 2.8- and 2.0-kb transcripts were expressed mainly in the kidney and the lungs. The mouse ACE2 gene was mapped to chromosome X 70.5 cM.

Efficiency of a New Fiberoptic Stylet Scope in Tracheal Intubation

BACKGROUND Failed or difficult tracheal intubation is an important cause of morbidity and mortality during anesthesia. Although a number of fiberoptic devices are available to circumvent this problem, many do not allow manual control of the flexion of the tip and necessitate time-consuming preparation, special training, or the use of an external light source. To improve these limitations, the authors designed a new fiberoptic stylet scope (FSS) that has a simple form of a standard stylet with the fiberoptic view and maneuverability of its tip. This study was undertaken to prospectively evaluate the effectiveness of the FSS in tracheal intubation. METHODS Thirty-two patients undergoing general surgery participated in this study. The authors used a standard laryngoscope only to elevate the tongue, then tracheal intubation was attempted with the glottic opening being viewed only through the FSS. The success rate, time necessary for intubation, hemodynamics, and adverse effects were recorded. RESULTS The success rate of tracheal intubation on the first attempt using the FSS was 94% (30 of 32 patients), and the remaining two patients were intubated successfully on the second attempt. The mean time necessary for the intubation procedure was 29+/-14 s in all patients (mean +/- SD). Changes in hemodynamics during intubation were well within acceptable ranges. There were no major adverse effects, but minor sore throat (28%) and minor hoarseness (25%) on the first postoperative day. CONCLUSIONS Tracheal intubation using the FSS proved to be a simple and effective technique for airway management.

Free hemoglobin concentrations in patients receiving massive blood transfusion during emergency surgery for trauma

Purpose: To determine free hemoglobin concentration in patients who received massive blood transfusion during emergency surgery for trauma with consideration of the storage of the transfused blood.Methods: Fifteen patients undergoing emergency surgery for multiple trauma and who received blood transfusion of more than 5,000 mL were studied. Transfusion of the stored whole blood in citrate-phosphate glucose solution using a micropore filter was started before surgery. Serum concentrations of hemoglobin (total: THb and free:fHb) and total haptoglobin (THp) were measured until 5,000 mL of blood had been transfused. Serum free haptoglobin (fHp) concentration was calculated. The correlation between the changes in hemoglobin or haptoglobin concentrations and total storage days of the transfused blood was analyzed by a simple regression analysis.Results: Free hemoglobin was detected after 2,000 mL transfusion. The THp and fHp decreased after 1,000 mL transfusion. Total storage time (days) of transfused blood had correlated with the changes of THp (P<0.0001) and fHp (P=0.0027) but not with the changes of THb (P=0.984) and fHb (P=0.834).Conclusion: After blood transfusion during surgery for trauma, serum haptoglobin concentration decreased with transfusion of ≥1,000 mL of whole blood with mean storage time of 12.2 dy. Free hemoglobin was detected after 2,000 mL transfusion when THp decreased to 1,000 mg·L−1. Serum haptoglobin concentrations correlated negatively with storage time (days) of transfused blood.RésuméObjectif: Déterminer la concentration d’hémoglobine libre chez des patients qui reçoivent une transfusion sanguine massive, pendant une opération urgente pour trauma, en considérant le temps de conservation du sang transfusé.Méthode: L’étude a porté sur 15 patients polytraumatisés, opérés d’urgence, qui ont reçu une transfusion de plus de 5 000 mL de sang. Avant l’intervention, on a commencé la transfusion de sang complet, conservé dans une solution de glucose citrate-phosphate, en utilisant un filtre micropore. Les concentrations sériques d’hémoglobine (totale: HbT et libre: Hbl) et d’haptoglobine totale (HpT) ont été mesurées jusqu’à ce que 5 000 mL de sang aient été transfusés. On a aussi noté l’haptoglobine sérique libre (Hpl). la corrélation entre les changements de concentrations d’hémoglobine ou d’aptoglobine et le nombre de jours de conservation du sang transfusé a été analysée par une analyse de régression simple.Résultats: L’hémoglobine libre a été détectée après 2 000 mL de transfusion. L’HpT et l’Hpl ont baissé après 1 000 mL de transfusion. Le temps total de conservation (jours) du sang transfusé était en corrélation avec les modifications d’HpT (P<0,0001) et d’HpI (P=0,0027), mais non avec les changements d’HbT (P=0,984) ni d’Hbl (P=0,834).Conclusion: Après la transfusion de sang pendant une opération pour trauma, la concentration sérique d’haptoglobine décroît avec une quantité ≥1 000 mL de sang complet transfusé et selon un temps moyen de conservation de 12,2 jours. L’hémoglobine libre est détectée après la transfusion de 2 000 mL tandis que l’Hp T baisse à 1 000 mg·L−1. Les concentrations sériques d’haptoglobine sont en corrélation négative avec le temps de conservation du sang transfusé.

Cerebrovascular carbon dioxide reactivity during general anesthesia : a comparison between sevoflurane and isoflurane

UNLABELLED We compared cerebrovascular carbon dioxide reactivity during the administration of sevoflurane and isoflurane anesthesia by measuring cerebral blood flow velocity (CBFV) as an indirect measurement of cerebral blood flow. Thirty patients, 20-70 yr old, undergoing lower abdominal surgery and without known cerebral or cardiovascular system disease, were randomly assigned to either sevoflurane or isoflurane treatment groups. Anesthesia was induced with thiopental 5 mg/kg IV and maintained with either sevoflurane or isoflurane in 67% nitrous oxide and oxygen. The CBFV and pulsatility index (PI) of the left middle cerebral artery were monitored with transcranial Doppler. The P(ETCO)2 was increased stepwise from 20 to 50 mm Hg by changing the respiratory rate with a constant tidal volume. At every 5-mm Hg stepwise change in P(ETCO)2, CBFV and PI were recorded. CBFV increased with increasing P(ETCO)2. CBFV was significantly smaller in the isoflurane group at P(ETCO)2 = 20-40 mm Hg than in the sevoflurane group. The rate of change of CBFV with changes in CO2 was larger in the isoflurane group than in the sevoflurane group. PI was constant over time and was not different between groups. In conclusion, hypocapnia-induced reduction of intracranial pressure might be more effective during the administration of isoflurane than sevoflurane. IMPLICATIONS Changes in cerebral blood flow caused by the changes of carbon dioxide tension are greater during the administration of isoflurane anesthesia compared with sevoflurane anesthesia. Attempts to decrease intracranial pressure by decreasing carbon dioxide tension may be more successful during isoflurane than sevoflurane anesthesia administration.

Is protease inhibitor a choice for the treatment of pre- or mild disseminated intravascular coagulation?

Objective: To investigate the effect of a protease inhibitor, gabexate mesylate, on patients with pre‐ or mild disseminated intravascular coagulation (DIC) in comparison with a control group receiving no anticoagulation therapy. Design: Prospective, randomized, controlled study. Setting: General intensive care unit at a general hospital. Patients: Adult patients (40) with a DIC score between 6 and 8 (pre‐ or mild DIC). Interventions: In 20 patients, gabexate mesylate (2 mg/kg/hr) was administered as 2 mL/hr in saline (treated group) and in another 20 patients, saline (2 mL/hr; control group) was administered during the study (7 days). Measurements and Main Results: The following variables were determined at the time of admission to the intensive care unit before treatment and 1, 3, 5, and 7 days thereafter: platelet count, antithrombin III activity, serum or plasma concentrations of fibrinogen, fibrin degradation product, D‐dimer, fibrin monomer, thrombin‐antithrombin III complex, and plasmin‐plasmin inhibitor complex, prothrombin time ratio, and DIC score. Two patients in the treated group and four in the control group were excluded from the study because they died during the study; therefore, 34 patients were analyzed. The measured variables of coagulation and fibrinolysis were not significantly different between the two groups, except for the D‐dimer on day 3 (the treated group showed a higher concentration). D‐dimer concentration and DIC score went down more quickly in the control group than the treated group, but not significantly. The mortality rate at 1 month was 40% (8 of 20) in the treated group and 35% (7 of 20) in the control group, without any differences between the two groups. Conclusions: In a limited number of patients (n = 34), gabexate mesylate (2 mg/kg/hr) could not inhibit coagulation or fibrinolysis and gabexate mesylate could not improve the DIC score or mortality rate in pre‐ or mild DIC.