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T Kumazawa

Publications and source records attributed to T Kumazawa.

At least 91 records · Page 5Linked to original sources
PubMed1998

Determination of solvent thinner components in human body fluids by capillary gas chromatography with trapping at low oven temperature for headspace samples.

A simple and sensitive method is presented for determination of solvent thinner components in human body fluids by capillary gas chromatography (GC) with a low oven temperature for trapping headspace vapor components. After heating a blood or urine sample containing ethyl acetate, benzene, butan-1-ol, toluene, butyl acetate, isoamyl acetate and ethylbenzene (internal standard) in a 7.5 ml vial at 90 degrees C for 30 min, 5 ml of headspace vapor were drawn into a glass syringe. All vapor was introduced through an injection port in the splitless mode into a DB-624 medium-bore capillary column at a 5 degrees C oven temperature for trapping the volatile compounds, and the oven temperature was programmed up to 110 degrees C for their detection by GC. These conditions gave sharp peaks, a good separation of each peak and low background noise for both whole blood and urine samples. As much as 3.58-55.1 and 3.52-57.9% of the six compounds, which had been added to vials, could be introduced to the GC instrument for whole blood and urine, respectively. The intra-day RSD values in terms of the introduction rate (net recovery) of the six compounds in whole blood and urine samples were < or = 8.1%. The calibration curves showed linearity in the range 0.78-400 ng per 0.5 ml whole blood or urine. The detection limits were 0.5-5 ng per 0.5 ml. The data on toluene in post mortem blood in an actual case are also presented.

Adult↗
PubMed1998

Effects of sevoflurane and isoflurane on free radical formation in the post-ischaemic reperfused heart.

Sevoflurane has been reported to generate oxygen free radicals. We have investigated whether sevoflurane or isoflurane enhances oxygen free radical formation in the post-ischaemic reperfused heart. An isolated rat heart-lung preparation was used. Thirty male Wistar rats were allocated to four groups: control, no drug, 2.5% sevoflurane and 1.4% isoflurane. The heart was perfused initially at a cardiac output of 30 mL min-1 and a mean arterial pressure of 70 mmHg. Ten minutes after the start of perfusion, the heart was rendered globally ischaemic for 10 min by reducing the preload and afterload to zero. Then, the heart was reperfused for 10 min. At the end of reperfusion, the heart was freeze dried for 6 days. The perfusate blood was collected just before and just after ischaemia and at the end of reperfusion. The formation of hydroxyl radicals in perfusate blood and heart was measured with high-performance liquid chromatography using salicylic acid. Hydroxyl radicals react with salicylic acid, yielding 2,3-, 2,4-, 2,5- and 3,4-dihydroxybenzoic acid (DHBA). Before and after ischaemia, there were no significant differences in cardiac output, systolic pressure, heart rate and right arterial pressure among the groups. The concentrations of 2,3-, 2,4-, 2,5- and 3,4-DHBA in the perfusate blood after ischaemia and reperfusion were significantly higher than those before ischaemia in all groups. However, there were no differences in the DHBA levels among groups. This study indicates that sevoflurane and isoflurane do not enhance hydroxyl radical formation in the post-ischaemic reperfused heart.

Anesthetics, Inhalation↗
PubMed1998

Accuracy and precision of "deep sternal" and tracheal temperatures at high- and low-fresh-gas flows.

The accuracy of tracheal temperature as a measure of core temperature is relatively poor during high-flow ventilation (6 litre min-1 fresh-gas flow). It is unknown if accuracy improves when lower fresh-gas flow rates are used. We tested the hypothesis that tracheal temperature accuracy would improve with low-flow ventilation (1 litre min-1). We studied 20 ASA Physical Status I and II patients undergoing general anaesthesia for lower abdominal surgery. Deep body temperatures were measured at the middle of the sternum using a Coretemp "deep-tissue" thermometer. Tracheal temperatures were monitored from thermistors incorporated into the tracheal tube cuffs. Oesophageal temperatures were measured from thermocouples incorporated into stethoscopes positioned at the point of maximal heart sounds. Sternal temperature correlated reasonably well with distal oesophageal temperatures, both being within the 0.5 degree C cut-off for accuracy and precision. Tracheal temperatures were lower than oesophageal temperatures during both high- and low-flow ventilation. Tracheal temperatures were 0.7 degree C less during high-flow ventilation and 0.9 degree C less during low-flow ventilation. The precision in both cases was adequate. We conclude that tracheal temperatures were insufficiently accurate for routine clinical use, even when fresh- gas flow was restricted to 1 litre min-1. In contrast, the deep temperatures were sufficiently accurate and precise for routine clinical use.

Adult↗
PubMed1998

Hypoxemia decreases the shivering threshold in rabbits anesthetized with 0.2 minimum alveolar anesthetic concentration isoflurane.

UNLABELLED: Shivering has been proposed as an etiology of postoperative hypoxemia. The difficulty with this theory is that hypoxemia inhibits shivering in unanesthetized cats, rats, and humans. However, anesthesia inhibits many protective reflexes, including the ventilatory response to hypoxemia. We therefore tested the hypothesis that arterial hypoxemia fails to inhibit shivering in lightly anesthetized rabbits. Rabbits were intubated and instrumented during exposure to surgical concentrations of anesthesia, and anesthesia was then maintained with 0.2 minimum alveolar anesthetic concentration isoflurane. The core was cooled at a rate of 2-3 degrees C/h by perfusing water at 10 degrees C through a colonic thermode. Core temperatures were recorded from the distal esophagus. Sustained, vigorous shivering was considered physiologically significant. The core temperature that triggering significant shivering identified the thermoregulatory threshold for this response. Arterial blood was sampled for gas analysis at the shivering threshold in each rabbit. Hypoxemia linearly reduced the shivering threshold from 36.7 degrees C at 130 mm Hg to 35.4 degrees C at 50 mm Hg (threshold = PaO2.0.019 + 34.3; r2 = 0.49). We failed to confirm our hypothesis: instead, even mild hypoxemia reduced the shivering threshold >1 C. A 1 C decrease in the shivering threshold is likely to prevent or stop most postoperative shivering because it exceeds the reduction produced by many effective anti-shivering drugs. These data do not support the theory that shivering causes postoperative hypoxemia. IMPLICATIONS: Shivering has been proposed as an etiology of postoperative hypoxemia. Our data, in contrast, show that mild hypoxemia inhibits shivering. Shivering is thus unlikely to be a cause of postoperative hypoxemia.

Anesthesia, Inhalation↗
PubMed1998

The accuracy and precision of four infrared aural canal thermometers during cardiac surgery.

BACKGROUND: Four infrared aural canal thermometers are currently available in Japan: Genius, Thermoscan, Quickthermo, and Thermopit. We therefore tested the hypothesis that each is sufficiently accurate and precise for clinical use. METHODS: For the purpose of this investigation, we considered accuracy to be the mean difference between the test thermometers and the reference thermocouple. Precision was considered to be the standard deviation of the difference between the test and reference values. We evaluated ten patients undergoing cardiopulmonary bypass with moderate hypothermia (approximately 30 degrees C). Aural canal temperatures were measured in random order with each infrared thermometer, and compared with readings from a thermocouple positioned at the contralateral tympanic membrane. RESULTS: Compared to the thermocouple, the Genius and Thermoscan both had regression slopes > 0.85 and correlation coefficients near 0.87; in contrast, slopes of the Quickthermo and Thermopit regressions were 0.68 and 0.53, respectively. The correlation coefficients for each were < 0.65. The accuracy (offset, or bias) was near 0 degree C with both the Genius and Thermoscan thermometers. In contrast, it was 1.1 degrees C with the Quickthermo and a full 2.3 degrees C with the Thermopit. The precision (standard deviation) of the measurements, however, was approximately 0.8 degree C in each case. CONCLUSION: We conclude that none of the tested aural canal infrared thermometers was sufficiently accurate and precise for perioperative use.

Aged↗
PubMed1998

Monoamine oxidase activities in catfish (Parasilurus asotus) tissues.

The substrate- and inhibitor-related characteristics of monoamine oxidase (MAO) were studied for catfish brain and liver. The kinetic constants for MAO in both tissues were determined using 5-hydroxytryptamine (5-HT), tyramine and beta-phenylethylamine (PEA) as substrates. For both tissues, the Vmax values were highest with 5-HT and lowest with PEA. The Km value for the brain was highest with 5-HT, followed by tyramine and PEA; but for the liver its value was highest with PEA, followed by 5-HT and tyramine, although all values were in the same order of magnitude. The inhibition of MAO by clorgyline and deprenyl by use of 5-HT, tyramine and PEA as substrates showed that the MAO-A inhibitor clorgyline was more effective than the MAO-B inhibitor deprenyl for both catfish tissues; a single form was present since inhibition by clorgyline or deprenyl with 1000 microM PEA showed single phase sigmoid curves. It is concluded that catfish brain and liver contain a single form of MAO, relatively similar to mammalian MAO-A.

Animals↗
PubMed1998

Quantitation of postmortem profenofos levels.

CASE REPORT: An 88-year-old woman was found dead, and suicidal ingestion of profenofos, an organophosphate pesticide, was suspected. METHOD: Gas chromatography-nitrogen phosphorus detection was employed for quantitation of profenofos after its identification by gas chromatography/mass spectrometry. RESULTS: The levels of profenofos in whole blood, urine, and gastric contents were 1200 ng, 350 ng, and 3.35 mg/mL, respectively.

Administration, Oral↗
PubMed1998

[The effect of carboplatin combined chemotherapy on renal function in patients with ovarian carcinoma].

OBJECTIVE: To investigate the changes of renal function during carboplatin (CBDCA) combined chemotherapy in patients with ovarian carcinoma. METHODS: 26 courses of postoperative systemic CBDCA therapy were carried out in 7 patients with ovarian carcinoma. During chemotherapy both systolic maximum and diastolic minimum blood flow velocity (Vmax, Vmin) and resistance index (RI) in renal segmental artery (SA) and interlobular artery (ILA) were meaured by color doppler weekly. Meanwhile renal creatinine clearance rate (Ccr) were also determined. 14 healthy women were taken as controls. RESULTS: From the 1st week to the 3rd week at the begining of CBDCA therapy, Vmax and Vmin in SA and ILA were significantly decreased (P < 0.01). A significant positive correlation was found between Ccr and the values of Vmin in SA and ILA (r = 0.52, P < 0.01). CONCLUSIONS: The results indicated that carboplatin combined chemotherapy could induce disturbances of renal function. The changes of renal function were related to renal blood flow velocity which could be used as a monitoring index of renal function.

Adult↗
PubMed1998

[Effects of lactated Ringer solution and acetated Ringer solution on hepatic ATP and L/P ratio in rats subjected to acute hemorrhage].

This study aimed to clarify the difference in the effects of lactated Ringer solution (LR) and acetated Ringer solution (AR) on hepatic ATP level and L/P ratio during acute hemorrhage in rats. There were no significant differences in the hepatic ATP levels and L/P ratios among 3 groups. Glycogen in LR group was higher than that in the control group. However pH and the base excess in LR and AR group were significantly higher than those in the C group. These results suggest that LR as well as AR may improve the metabolic acidosis, and LR may be more useful than AR with regard to glucose supply during acute hemorrhage.

Acute Disease↗
PubMed1998

[Comparative effect of tranexamic acid on the reduction of bleeding during and after cardiac surgery].

The administration of tranexamic acid (TA), an antifibrinolytic agent, prior to cardiopulmonary bypass (CPB) has been reported to reduce bleeding after cardiac surgery. In a retrospective clinical trial, 99 adults patients undergoing open heart surgery received TA (CABG, TA (+): n = 20; Valve replacement, TA (+): n = 20) or did not receive TA (CABG, TA (-): n = 20: Valve replacement, TA (-): n = 19). In the TA group, just after induction of general anesthesia, a 160 mg.kg-1 dose of TA was administered intravenously. In each group, bleeding volumes during operation, and at 6 and 24 hours after operation, were compared. Patients of [CABG, TA (+)] group had significantly less intraoperative and total blood loss [total blood loss 608 g : 313 g, intraoperatively, 134 g at 6 hours, and 296 g at 24 hours] compared with [CABG, TA (-)] group (total blood loss 1043 g: 640 g, intraoperatively, 232 g at 6 hours, and 403 g at 24 hours). Additionally, in patients of Valve replacement, TA (+) group had less but not significant total blood loss (total blood loss 903 g: 523 g, intraoperatively, 173 g at 6 hours, and 380 g at 24 hours) compared with TA (-) group (total blood loss 1237 g: 863 g, intraoperatively, 214 g at 6 hours, and 374 g at 24 hours). TA administered prior to CPB may reduce the amount of bleeding during and after cardiac surgery.

Adult↗
PubMed1998

[A case of air embolism during tubal insufflation].

Air embolism occurred immediately after tubal insufflation in a 40-yr-old female patient following abdominal total hysterectomy under general anesthesia. Abrupt decreases in Etco2, Spo2, and blood pressure were observed. Blood gas analysis revealed a marked difference between PaCO2 and EtCO2. The patient recovered soon and was extubated in the operating room. The post operative course was uneventful. Monitoring of EtCO2 was effective for early detection of air embolism.

Adult↗
PubMed1998

[Effects of hypertonic lactated Ringer's solution on hepatic ATP and L/P ratio in rats subjected to acute hemorrhage].

This study aimed to clarify the difference in the effects of hypertonic lactated Ringer's solution (HLS) on hepatic ATP level and L/P ratio during acute hemorrhage in rats. The hepatic ATP level in HLS 230 group was lower, and L/P ratio in HLS 300 group was higher than those in the control group. There was no significant difference in glycogen among 4 groups. However, pH and the base excess in HLS 230 and HLS 300 group were significantly higher than those in the C group. Heart rate in HLS 300 group was significantly lower than that in the C group. These results suggest that HLS may not be useful with regard to the hepatic energy metabolism, although it improves the metabolic acidosis during acute hemorrhage.

Acute Disease↗
PubMed1997

Capillary gas chromatography with cryogenic oven temperature for headspace samples: analysis of chloroform or methylene chloride in whole blood.

A new and sensitive gas chromatography (GC) method for measurement of chloroform or methylene chloride in whole blood is presented. Trace levels of these analytes present in the headspace of samples were cryogenically trapped prior to on-line GC analysis. After heating of a blood sample containing chloroform and methylene chloride (internal standard, and vice versa) in a 7.0-mL vial at 55 degrees C for 20 min, 5 mL of the headspace vapor was drawn into a glass syringe. All vapor was introduced into an Rtx-Volatiles middle-bore capillary column in the splitless mode at -30 degrees C oven temperature to trap the entire analytes, and the oven temperature was programmed up to 280 degrees C for detection of the compounds and for cleaning of the column. The present conditions gave sharp peaks for both chloroform and methylene chloride and very low background noises for whole blood samples. As much as 11.5 and 20.0% of chloroform and methylene chloride, respectively, which had been added to whole blood in a vial, could be introduced into the GC column. The calibration curves showed linearity in the range of 0.05-5.0 micrograms/0.5 mL of whole blood. The detection limit was estimated to be about 2 ng/0.5 mL. The coefficients of intraday and interday variations were 1.31 and 8.90% for chloroform and 1.37 and 9.03% for methylene chloride, respectively. The data on chloroform or methylene chloride in rat blood after inhalation of each compound were also presented.

Animals↗
PubMed1997

Evidence that protein kinase C activation is involved in the excitatory and facilitatory effects of bradykinin on canine visceral nociceptors in vitro.

The involvement of protein kinase (PK) C activation in the effects of bradykinin (BK) on peripheral nociceptors, polymodal receptors, was examined using canine testis-spermatic nerve preparations in vitro. Phorbol 12,13-dibutyrate 0.1 microM, which activates PKC, suppressed the BK-induced excitation when applied for 3-5 min prior to BK application, but facilitated it when applied simultaneously with BK. Neither effect was induced by an inactive phorbol ester, 4alpha-phorbol 12, 13-didecanoate, demonstrating that both effects were mediated through the activation of PKC. In addition, staurosporine 1 microM, a PK inhibitor, suppressed both BK-induced excitation and facilitation of the heat response of testicular polymodal receptors without influencing on-going activities and the heat response itself. These results suggest that PKC activation is involved in the excitatory and facilitatory effects of BK on peripheral nociceptors.

Adaptation, Physiological↗
PubMed1997

Calcitonin gene-related peptide- and substance P-like immunoreactive fibers in the spermatic nerve and testis of the dog.

In order to determine if calcitonin gene-related peptide (CGRP) and substance P (SP) coexist in peripheral spermatic nerve fibers, we carried out a double-staining immunofluorescence study using confocal microscopy and fluorescence microscopy. CGRP- and SP-like immunoreactivity (LI) coexisted in the spermatic nerve trunk and in the single fibers running along the surface of the testis. The great majority of the SP-containing fibers also held CGRP-LI, although some fibers contained CGRP-LI without SP-LI. These observations are consistent with previous observations on testicular dorsal root ganglion neurons. Additionally, we carried out an immunogold silver staining for CGRP and found CGRP-containing nerve bundles, single nerve fibers and their nerve terminals. Some CGRP-containing nerve terminals were located very superficially in the tunica albuginea (<5 microm from the surface).

Animals↗
PubMed1997

Comparison of distal oesophageal temperature with "deep" and tracheal temperatures.

PURPOSE: To compare distal oesophageal (reference) temperature with "deep-sternal," "deep-forehead," and tracheal temperatures, establishing the accuracy and precision of each. METHODS: We studied 20 patients undergoing general anaesthesia for gynaecological surgery. Their lungs were mechanically ventilated with a circle system, at a fresh-gas flow rate of 6 L.min-1 Respiratory gases were not warmed or humidified. Tracheal temperatures were recorded from a Trachelon tube inserted approximately 21 cm. Deep-body temperatures were measured at the sternum and forehead using a Coretemp thermometer. The principle of the method is to null thermal flux through a cutaneous disk, thus obliterating thermal gradients between the sides of the disk, skin surface, and subcutaneous tissues. Distal oesophageal temperatures were measured from thermocouples incorporated into oesophageal stethoscopes. Tracheal and deep-tissue temperatures were compared with oesophageal temperature using regression and Bland and Altman analyses. RESULTS: Tracheal, sternal, and forehead temperatures correlated similarly with distal oesophageal temperature, correlation coefficients (r2) being 0.7 in each case. The offset (oesophageal temperature minus study site) was considerably larger for tracheal temperature (0.7 degree C) than for the other sites (0.2 degree C). However, the precision was only 0.3 degree C at each site. CONCLUSION: Our data suggest that tracheal temperatures may not be an adequate substitute for conventional core-temperature monitoring sites. In contrast, the accuracy and precision of deep-tissue temperature monitoring at the sternum and forehead was sufficient for clinical use.

Anesthesia, General↗
PubMed1997

Increased stress response and beta-phenylethylamine in MAOB-deficient mice.

MAOA and MAOB are key iso-enzymes that degrade biogenic and dietary amines. MAOA preferentially oxidizes serotonin (5-hydroxytryptamine, or 5-HT) and norepinephrine (NE), whereas MAOB preferentially oxidizes beta-phenylethylamine (PEA). Both forms can oxidize dopamine (DA). A mutation in MAOA results in a clinical phenotype characterized by borderline mental retardation and impaired impulse control. X-chromosomal deletions which include MAOB were found in patients suffering from atypical Norrie's disease, which is characterized by blindness and impaired hearing. Reduced MAOB activity has been found in type-II alcoholism and in cigarette smokers. Because most alcoholics smoke, the effects of alcohol on MAOB activity remain to be determined. Here we show that targetted inactivation of MAOB in mice increases levels of PEA but not those of 5-HT, NE and DA, demonstrating a primary role for MAOB in the metabolism of PEA. PEA has been implicated in modulating mood and affect. Indeed, MAOB-deficient mice showed an increased reactivity to stress. In addition, mutant mice were resistant to the neurodegenerative effects of MPTP, a toxin that induces a condition reminiscent of Parkinson's disease.

Animals↗