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Sumio Hoka

Publications and source records attributed to Sumio Hoka.

49 records · Page 3Linked to original sources
PubMed2002

Porcine Fas-ligand gene: genomic sequence analysis and comparison with human gene.

Thymic Fas-ligand (FasL) cDNA and hepatic FasL genomic sequences were obtained from a 2-month-old LW pig. From these nucleotide sequences, amino acid sequence was deduced and compared with FasL sequences obtained from various animals. This comparison reveals that porcine FasL is closer to that of human, macaca and cat, and differs more from mouse and rat. The extracelluar domains of porcine and human FasL proteins appear to be functionally compatible. The complete genomic DNA sequence of porcine FasL was also compared with its human counterpart. Exons showed 80-89% nucleotide homology between pig and human, while introns showed 64-69% nucleotide homology. Sequence comparison by Harr plot analysis revealed many stretches within introns having identical sequences, suggesting that the sites may have unidentified common functions. One potential extra exon between exons 2 and 3 was located within porcine intron 2. This potential exon has no counterpart in human FasL intron 2. Whether or not this extra exon can be expressed and could cause additional immunological responses remains to be investigated. For future xenotransplantation, it is important to compare porcine and human genomic sequences, and to investigate their system compatibilities.

Amino Acid Sequence↗
PubMed2002

Role of kinin and prostaglandin in cutaneous thermal nociception.

Involvements of kinin and prostaglandin and their interaction in noxious thermal stimuli were investigated in noninflamed and inflamed rats. The nociceptive response was evaluated from the escape latency of foot withdrawal to the thermal stimuli with a beam of light. The escape latency in kininogens-deficient Brown Norway (B/N-) Katholiek rats was significantly longer than that in the normal strain, B/N-Kitasato rats. The latency in B/N-Kitasato rat was prolonged by administration of a bradykinin (BK) B2 receptor antagonist, FR173657 (30 mg/kg, p.o.), whereas it was shortened by pretreatment with a kininase II inhibitor, captopril (10 mg/kg, i.p.). Both agents did not affect the latency in B/N-Katholiek rats. In normal Sprague-Dawley (SD) rat, administration of indomethacin did not change the escape latency against the thermal stimuli. In contrast, administration of indomethacin or a relatively cyclooxygenase-1-selective inhibitor, mofezolac (10 mg/kg, p.o.) significantly reduced numbers of writhing reaction in mice induced by acetic acid solution. Injection of lipopolysaccharide (1 mg/kg, i.v.) resulted in shortening escape latency at 8 h after the injection in B/N-Kitasato rats. This hyperalgesia could be reversed by pretreatment of the rats with indomethacin, a cyclooxygenase-2-selective inhibitor JTE-522 (10 mg/kg, p.o.), or FR173657, but not with mofezolac. The hyperalgesia was not seen in B/N-Katholiek rats. These results indicate that kinin has major participation in peripheral skin thermal nociception under noninflamed condition, although cyclooxygenases may have little participation. Prostaglandins produced by cyclooxygenase-2 could coordinate with BK to elicit hyperalgesia during inflammation induced by lipopolysaccharide.

Animals↗
PubMed2002

[New algorithm for oscillometric noninvasive automatic arterial pressure measurement in patients with atrial fibrillation].

Oscillometric noninvasive arterial pressure monitoring devices frequently fail to measure pressure precisely in patients with arrhythmia, such as atrial fibrillation, because beat-by-beat changes in pulse pressure and mean pressure level distort the relation between cuff pressure and oscillometric wave amplitude. To overcome this problem, we developed a new algorithm for oscillometric measurement in which oscillometric wave amplitude is corrected according to changes in pulse pressure and mean arterial pressure level. In 7 patients with atrial fibrillation, we compared systolic pressure thus estimated with that simultaneously measured invasively in the radial artery and averaged during oscillometric measurement. Correction based on invasively obtained beat-by-beat pulse pressure and mean pressure level decreased the ratio of unmeasurable cases from 11 to 4%. Correction based on plethysmographically estimated pulse pressure decreased unmeasurable cases to 6% (P < 0.01). Standard error of systolic pressure estimates was 6.44 +/- 1.83, 4.10 +/- 0.85, and 4.75 +/- 1.26 mmHg with no, invasive, and plethysmographical correction in this order (P < 0.01). We conclude that oscillometric wave amplitude correction based on beat-by-beat pulse pressure and mean arterial pressure level lessened the number of unmeasurable cases and improved measurement precision in patients with atrial fibrillation.

Algorithms↗
PubMed2002

[Clinical characteristics of perioperative pulmonary thromboembolism: analysis of 18 patients in Kitasato University Hospital].

Clinical characteristics of perioperative pulmonary thromboembolism (PTE) at Kitasato University Hospital in Japan were analyzed. Eighteen patients were documented as apparent diagnosis of PTE which developed perioperatively in the period of 1991-1999. The incidence of PTE was 18 out of approximately 50,000 surgical cases. Mean age of patients was 48 years (range, 21 to 79 years). There were 4 men and 14 women. Perioperative risk factors included obesity with body mass index over 26.4 (6/18), and prolonged bed rest after surgery more than 4 days (6/18). Perioperative PTE tended to occur in patients with laparoscopic cholecystectomy (3/18) and cesarean section (3/18). Seven out of 18 PTE patients died. It should be noted that perioperative PTE is prevalent in patients with risk factors of obesity and prolonged bed rest after surgery, and that laparoscopic cholecystectomy and cesarean section may become additional risk factors in patients who are otherwise healthy young adults.

Adult↗
PubMed2002

[Serum and urinary inorganic fluoride concentrations with renal and hepatic functions after repeated sevoflurane anesthesia].

The purpose of this study is to examine changes in serum and urinary inorganic fluoride (F) concentrations with their effects on renal and hepatic functions after repeated sevoflurane anesthesia with relatively short time interval. Eight patients received sevoflurane anesthesia twice within 7 days for gynecological surgery. Serum and urine F levels before induction, 0.5 and 1 hour after induction, and 0.5 hour after anesthesia were compared between first and second anesthesia. There were no significant differences in serum and urine F concentrations at the same point between first and second anesthesia. Two obese patients exhibited peak concentrations greater than 50 mumol.l-1 of F. Laboratory findings of renal function remained stable throughout 2 operations, whereas hepatic function deteriorated in the two obese patients after the first anesthesia, and resolved within 14 days after the second anesthesia. In conclusion, it is suggested that the second exposure to sevoflurane within 7 day interval does not alter the sevoflurane metabolism. However, obesity may contribute to a rise in serum inorganic fluoride after repeated sevoflurane anesthesia.

Adult↗
PubMed2002

[Paravertebral block for labor analgesia in a parturient with idiopathic thrombocytopenia].

A parturient with idiopathic thrombocytopenia received labor analgesia with bilateral paravertebral blocks, because epidural analgesia was contraindicated due to her low platelet count (69,000.microliter-1) even after intravenous administration of freeze-dried sulfonated human normal globulin (400 mg.kg-1.day-1) and transfusion of platelet (20 units.day-1). In spite of predonisolone (1 mg.kg-1.day-1) p.o., her platelet counts could not increase at early gestation period. Prior to the induction of the labor, two catheters were inserted into T 11 bilateral paravertebral spaces, then 0.2% ropivacaine 10 ml was administered in each side, followed by the infusion at 5 ml.hr-1 each for the management of first stage of labor pain. Labor was induced with oxytocin infusion at 2.5-5.0 mU.min-1. As she requested additional analgesia in the second stage of labor, fentanyl 50 micrograms was administered twice intravenously. The labor course was uneventful with adequate analgesia, and the neonate (2,826 g) was vigorous with Apgar scores 9/10. Complications associated with this block such as hypotension, vascular or pleural punctures and pneumothorax were not seen. Bilateral paravertebral blocks may provide adequate analgesia as an alternative method for labor analgesia in a parturient with thrombocytopenia when conventional epidural analgesia is contraindicated.

Adult↗
PubMed2002

[A case of cardiac arrest at induction of anesthesia for postpartum hysterectomy].

Although peripartum cardiac arrest is rare, the prognosis of the event may be worse than in nonpregnant patients because the events is often associated with pulmonary or amniotic embolisms. The following report is a case of cardiac arrest which occurred at the induction of anesthesia for the postpartum hysterectomy. A 31-year-old woman was treated with infusion of ritodrine chloride for preterm labor and placenta previa. Elective cesarean section was performed at 37 weeks' gestation for her delivery under epidural anesthesia. Following the operation, the total hysterectomy was scheduled due to the continuous massive bleeding. She rapidly developed ventricular tachycardia, following trachea intubation with propofol and suxamethonium. Since she was not resuscitated with cardiac massage, we started intravenous epinephrine, electronic cardioversion, the percutaneous cardiopulmonary support and intra-aortic balloon pumping with epinephrine and dopamine infusions leading to a successfully outcome. In this case, we believe that the combination of propofol and suxamethonium had the most impact on producing the cardiac arrest. Therefore, the case emphasizes the potential danger of using these combination for patients who have been treated with ritodrine.

Adult↗
PubMedDate not supplied

Labour analgesia guided by echocardiography in a parturient with primary dilated cardiomyopathy.

PURPOSE: To evaluate the effects of intrathecal analgesics on cardiac function during labour analgesia using echocardiography in a parturient with idiopathic dilated cardiomyopathy (DCM). CLINICAL FEATURES: Induction of labour was planned in a 35-yr-old primiparous woman suffering from DCM. In order to stabilize hemodynamics in this patient, we induced continuous spinal analgesia with an infusion of fentanyl and epinephrine. Although her analgesia was well maintained for three hours during the first stage of labour, the patient complained of pain towards the second stage of labour. At this point, we administered bupivacaine intrathecally to alleviate her pain. Transthoracic echocardiography showed that the left ventricular end-diastolic and systolic dimensions, as well as the ejection fraction were not impaired by use of these analgesic medications. CONCLUSION: Measurement of left ventricular dimensions by echocardiography allowed us to monitor the patient's response to intrathecal analgesic medications. In this patient with DCM, analgesia with intrathecal fentanyl and bupivacaine was well tolerated.

Adult↗
PubMedDate not supplied

Intrathecal mepivacaine and prilocaine are less neurotoxic than lidocaine in a rat intrathecal model.

BACKGROUND AND OBJECTIVES: Histologic evidence of the comparative neurotoxicity of lidocaine, mepivacaine, and prilocaine is incomplete. We compared the intrathecal neurotoxicity in rats among these 3 drugs based on morphologic and neurofunctional findings. METHODS: Rats (n=169) randomly received 0.12 microL/g of 0%, 2%, 5%, 7.5%, 10%, or 20% lidocaine, mepivacaine, or prilocaine or 25% glucose dissolved in distilled water via a chronically implanted intrathecal catheter. The effect of the agents on neurofunction was evaluated by movement of the hind limb (behavior test) and by sensory threshold (paw-stimulation test). The L1 spinal cord, the posterior and anterior roots, and the cauda equina were removed en bloc 5 days later and examined by light and electron microscopy. RESULTS: A significant decrease in sensory threshold or irreversible hind-limb limitation was observed only in rats receiving 20% lidocaine. Morphologic abnormalities characterized by axonal degeneration were observed in rats receiving > or =7.5% lidocaine, 20% mepivacaine, and 20% prilocaine, at the posterior white matter and the proximal portion of the posterior root just at the entrance into the spinal cord. The incidence of lesions was significantly higher in rats receiving lidocaine than mepivacaine and prilocaine. CONCLUSION: It is suggested that intrathecal mepivacaine and prilocaine are less neurotoxic than highly concentrated lidocaine in a rat intrathecal model.

Anesthetics, Local↗
PubMedDate not supplied

Neurotoxicity of intrathecally administered bupivacaine involves the posterior roots/posterior white matter and is milder than lidocaine in rats.

BACKGROUND AND OBJECTIVES: Clinical and laboratory studies suggest that lidocaine is more neurotoxic than bupivacaine. However, histological evidence of their comparative neurotoxicity is sparse. We thus pathologically and functionally compared the intrathecal neurotoxicity of these agents. METHODS: Rats received 0.12 microL/g body weight lidocaine (0%, 2%, 10%, or 20%) or bupivacaine (0%, 0.5%, 2.5%, or 5%) in distilled water via an intrathecal catheter. The influence of high osmolarity was also examined using 5% bupivacaine in 20% glucose solution (5% BG) and a control 25% glucose solution. The L3 spinal cord, the posterior and anterior roots, and the cauda equina were examined by light and electron microscopy. Walking behavior and sensory threshold were investigated as neurofunctional tests. RESULTS: The posterior root and posterior white matter showed axonal degeneration in rats treated with 10% and 20% lidocaine and 5% bupivacaine in distilled water (5% BDW) and in 5% BG, but not in rats treated with 2% lidocaine, 0.5% and 2.5% bupivacaine, distilled water, or 25% glucose solution. The histological damages were more severe in 20% lidocaine-treated rats than in 5% bupivacaine-treated rats. The damage of posterior white matter was observed only when the posterior root was severely injured. No significant difference of histological findings was observed between 5% BDW and 5% BG. Functional abnormalities were found only in rats treated with 20% lidocaine. CONCLUSIONS: The neurotoxic lesions caused by bupivacaine and lidocaine were indistinguishable in the primary site and the extending pattern, such as axonal degeneration originating from the posterior roots and extending to the posterior white matter. The intrathecal neurotoxicity is greater in lidocaine than in bupivacaine.

Anesthesia Recovery Period↗
PubMedDate not supplied

Intrathecal lidocaine causes posterior root axonal degeneration near entry into the spinal cord in rats.

BACKGROUND AND OBJECTIVES: The neurotoxicity of lidocaine is not fully understood, and the primary lesion of lidocaine-induced spinal neurotoxicity has not been defined. Here we examine the effects of various concentrations of intrathecally administered lidocaine. METHODS: Forty-seven Wistar rats received 20%, 10%, 7.5%, 5%, 3%, or 0% lidocaine dissolved in distilled water, or 25% glucose solution via a chronically implanted intrathecal catheter. The spinal cord at L1, posterior and anterior roots, and cauda equina were dissected out 5 days later, sectioned, and prepared for light and electron microscopy. The effect of the agent on function was evaluated by movement of the hind limb (behavior test) and by sensory threshold (paw stimulation test). Another 7 rats were used to establish the precise locus of lesion within the posterior root after intrathecal 20% lidocaine injection. RESULTS: Rats treated with 10% or 20% lidocaine developed lesions both in the posterior roots and posterior columns, characterized by axonal degeneration. Rats injected with 7.5% lidocaine developed degenerative lesions limited to the posterior roots. Lesions in the posterior roots were localized to the proximal portion of the roots. Injections of 5% or less lidocaine did not cause any pathological changes. One of 5 rats receiving 20% lidocaine showed hind-limb paralysis for 4 days, but the remaining 4 rats recovered within 4 days after drug injection. Rats injected with < or = 10% lidocaine were completely recovered within 4 hours. The threshold for paw stimulation was significantly decreased in rats injected with 20% lidocaine. CONCLUSION: Our results suggest that spinal lidocaine neurotoxicity after supra-clinical concentrations of lidocaine is limited initially to the posterior roots at their entry to the spinal cord, and the extent and severity of the lesions are closely associated with lidocaine concentration. Unlike severe lesions in rats injected with 20% lidocaine, mild lesions caused by lower concentrations may not manifest neurofunctional deficits.

Anesthetics, Local↗