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Biomedical subjects

T Matsukawa

Publications and source records attributed to T Matsukawa.

At least 37 records · Page 2Linked to original sources
PubMed2001

Atropine prevents midazolam-induced core hypothermia in elderly patients.

STUDY OBJECTIVE: To test the hypothesis that core temperature is well preserved when atropine and midazolam are combined. DESIGN: Randomized, blinded study. SETTING: Department of Anesthesia, Yamanashi Medical University. PATIENTS: 40 elderly, ASA physical status I and II patients (aged more than 60 years). INTERVENTIONS: Patients were randomly assigned (n = 10 per group) to premedication with: 1) saline control; 2) midazolam 0.05 mg/kg; 3) atropine 0.01 mg/kg; and 4) midazolam 0.05 mg/kg combined with atropine 0.01 mg/kg. All premedication was given on the ward at approximately 8:30 am, approximately 30 minutes before induction of anesthesia. MEASUREMENTS AND MAIN RESULTS: Core temperatures were measured at the right tympanic membrane. Mean skin temperature was calculated as 0.3 x (T(chest) + T(arm)) + 0.2 x (T(thigh) + T(calf)). Fingertip perfusion was evaluated using forearm minus fingertip and calf minus toe, skin-surface temperature gradients. Temperatures were evaluated at the time of premedication and 30 minutes later, just before induction of anesthesia. Core temperature remained nearly constant in the control patients (0.1 +/- 0.2 degrees C; mean +/- SD), whereas it decreased significantly in the patients given midazolam alone (-0.3 +/- 0.1 degrees C). Atropine alone increased core temperature (0.3 +/- 0.2 degrees C), although the increase was not statistically significant. The combination of midazolam and atropine attenuated the hypothermia induced by midazolam alone (0.0 +/- 0.2 degrees C). Initial skin-temperature gradients exceeded 0 degrees C in all groups, indicating that the patients were vasoconstricted. The gradients were unchanged by premedication with saline or atropine. Midazolam significantly decreased the gradient (-1.8 +/- 1.1 degrees C), as did the combination of midazolam and atropine (-1.4 +/- 0.9 degrees C). CONCLUSIONS: The thermoregulatory effects of benzodiazepine receptor agonist and cholinergic inhibitors oppose each other, and the combination leaves core temperature unchanged.

Aged↗
PubMed2001

Preoperative blood pressure and intraoperative hypothermia during lower abdominal surgery.

BACKGROUND: Preoperative factors including age and body habitus affect intraoperative hypothermia during general anesthesia. We hypothesized that preoperative blood pressure also plays a contributory role in the induction of intraoperative hypothermia. METHODS: We evaluated the effect of preoperative systolic blood pressure (SBP) on core temperature during lower abdominal surgery under general anesthesia. In 36 female patients under 65 years of age, patients with a preoperative SBP of 140 mmHg or greater upon arrival in the operating theater were assigned to the high SBP group (n=18), while those with SBP below 140 mmHg were assigned to the normal SBP group (n=18). Anesthesia was maintained with isoflurane and nitrous oxide combined with epidural buprenorphine, and routine thermal care was provided intraoperatively. RESULTS: There were no significant differences in age, height or weight between the two groups. Tympanic membrane temperature in the normal SBP group started to decrease significantly from 15 min after induction of anesthesia compared to that in the high SBP group, and continued to decrease further at two hours after induction. Vasoconstriction threshold, determined to be tympanic membrane temperature at the time when a forearm minus finger skin surface gradient exceeded 0 degrees C, was significantly higher in the high SBP group than in the normal SBP group. CONCLUSION: These results suggest that preoperative SBP has some preventive effect on the decrease in intraoperative core temperature during lower abdominal surgery under general anesthesia.

Adult↗
PubMed2001

Intravenous ketamine attenuates arterial pressure changes during the induction of anaesthesia with propofol.

BACKGROUND AND OBJECTIVE: To investigate whether the administration of ketamine before induction with propofol produces a smaller decrease in arterial pressure. METHODS: Twenty-two patients were assigned to one of two groups to receive either propofol with ketamine (n = 11) or propofol alone (n = 11, control). Anaesthesia was induced with 2 mg kg-1 propofol and 0.5 mg kg-1 ketamine or 2 mg kg-1 propofol alone. Ketamine was administered 1 min prior to induction with propofol. Immediately after induction with propofol, vecuronium (0.15 mg kg-1) was administered. Four minutes after administration of vecuronium, tracheal intubation was performed. Anaesthesia was maintained using sevoflurane (0.5%) in 66% nitrous oxide until 3 min after intubation. Systolic, diastolic and mean arterial pressure and heart rate were recorded on arrival, directly before induction with propofol, prior to tracheal intubation, immediately after intubation and at 3 min after intubation. RESULTS AND CONCLUSIONS: Administration of ketamine before induction with propofol preserved haemodynamic stability compared with induction with propofol alone.

Anesthesia↗
PubMed2001

Up-regulation of upstream stimulatory factors by protein malnutrition and its possible role in regulation of the IGF-binding protein-1 gene.

Protein malnutrition drastically induces the expression of the IGF-binding protein-1 (IGFBP-1) gene. We have previously shown that the region between -77 and -112 bp upstream of the rat IGFBP-1 gene contributes to the response of this gene to amino acid limitation. In an attempt to elucidate the basis of the responsiveness of this putative amino acid response unit (AARU), we searched the nucleus of the rat liver for a trans-acting factor whose binding to AARU was dependent on protein nutrition. Liver nuclear extracts of rats fed a protein-free diet and of those fed a control diet were compared by EMSA using the AARU as probe. One of the protein-probe complexes underwent a drastic increase after dietary protein deprivation. Assays using specific antibodies and several competitor oligonucleotides led to identification of the protein composing the complex as upstream stimulatory factor-1 (USF) and USF-2. The binding site of the USF proteins in the AARU turned out to be a CACGGG sequence that was homologous to the consensus USF-binding sequence (E box; CANNTG). Further, Western blot analyses showed that a protein-free diet caused significant increases in USF-1 and USF-2 levels. Thus, elevated expression of the IGFBP-1 gene under protein malnutrition can be attributable to increased binding of USF to its promoter, which results from increased USF levels. The data suggest that the changes in these ubiquitously distributed transcription factors play an important role in the nutritional regulation of expression of mammalian genes.

Animals↗
PubMed2001

Localization of nitric oxide synthase activity in unfertilized oocytes and fertilized embryos during preimplantation development in mice.

Changes in the activities of nitric oxide synthase (NOS) during embryonic development, and the distribution of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) isoforms were examined in unfertilized mouse oocytes at the second meiotic metaphase (MII) stage and in fertilized mouse embryos during preimplantation development. In addition, the effects of NOS inhibitors on mouse preimplantation development in vitro were investigated. The activities of NOS in MII oocytes and fertilized embryos during the preimplantation period were determined by NADPH-diaphorase staining. Although NOS activity was detected in unfertilized MII oocytes, the intensity of staining was much weaker than that of fertilized embryos at the one-cell stage. There was a decrease in NOS activity in embryos from the four-cell to the eight-cell stage; however, NOS activity increased again in embryos at the morula stage, particularly in the inner cell population. In the expanded blastocysts, staining was confined to the inner cell mass. Immuno-cytochemical staining showed that eNOS and iNOS were expressed in the cytoplasm of oocytes and embryos during the preimplantation period, and eNOS was also distributed in the nuclei of the embryos. When one-cell embryos were treated with 1 mmol N(omega)-nitro-L-arginine methyl ester (L-NAME) l(-1), their development in vitro was arrested at the two-cell stage. This inhibition of development was overcome by the addition of 1 mmol L-arginine l(-1) to the medium. These observations indicate that nitric oxide plays an important role as a diffusible regulator of cell proliferation and differentiation, especially at the developmental transition from the two-cell to the four-cell stage during preimplantation development of mice.

Animals↗
PubMed2001

[The effect of sedation with propofol and fentanyl during epidural catheter insertion on intraoperative temperatures].

General anesthesia inhibits thermoregulation by suppressing tonic vasoconstriction and facilitates a core-to-peripheral redistribution of body heat, which is the major cause of core hypothermia during the first hour of anesthesia. We randomly assigned 16 patients to two groups; 1) patients who received fentanyl (1 microgram.kg-1, i.v.) and propofol (1.5 mg.kg-1.h-1) during insertion of epidural catheters (P group), and 2) no drug (control) group (C group). We measured tympanic (Ttym) and skin temperatures at the time of admission to operating rooms, after dural catheter insertion, before induction of anesthesia, just after induction of anesthesia, and one hour after induction. After dural catheter insertion, forearm-finger tip skin temperature gradient of P group was significantly smaller than C group. One hour after induction of anesthesia, Ttym of P group was significantly higher than C group. We can conclude that a sedative dose of propofol and fentanyl before induction of general anesthesia inhibits redistribution hypothermia during general anesthesia.

Aged↗
PubMed2001

[Anesthetic management of a child with congenital sensory neuropathy with anhydrosis].

Congenital sensory neuropathy with anhydrosis is a rare disorder characterized by insensitivity to pain with normal tactile perception, self-mutilation, anhydrosis, recurrent unexplained fever, mental retardation and variable autonomic abnormality. We managed a 14-year-old boy with this syndrome who underwent repair of right femur fracture. Anesthesia was induced with propofol and ketamine. Adequate depth of anesthesia was carefully controlled by processed electroencephalogram, and core body temperature was maintained at 37.0 degrees C during the surgery. The patient was well sedated, and nausea and vomiting were not noted postoperatively. Use of droperidol and propofol may be beneficial for anesthetic management of this syndrome, because droperidol exerts residual hypnotic effect postoperatively, and both drugs have antiemetic property.

Adolescent↗
PubMed2000

Diversity of N-acetylglucosamine-6-O-sulfotransferases: molecular cloning of a novel enzyme with different distribution and specificities.

N-Acetylglucosamine-6-O-sulfotransferase (GlcNAc6ST) transfers sulfate to the C-6 position of non-reducing N-acetylglucosamine (GlcNAc) residues. We cloned human and mouse cDNAs encoding a novel GlcNAc6ST, designated as GlcNAc6ST-4, which showed sequence identities of 26 to 41% to other GlcNAc6STs. Human organs with strong expression of the enzyme mRNA were the heart, spleen, and ovary, while in the mouse strong expression was detected in the kidney. The enzyme expressed in CHO cells preferentially acted on mannose-linked GlcNAc, while a core 2 mucin-type oligosaccharide and an N-acetyllactosamine oligomer also served as acceptors. The distribution and the specificity of GlcNAc6ST are different from those of GlcNAc6STs identified previously.

Animals↗
PubMed2000

Continuous nicardipine infusion to control blood pressure after evacuation of acute cerebral hemorrhage.

PURPOSE: To explore the long-term effects of the calcium antagonist, nicardipine, on cerebral hemodynamics in patients with acute cerebral hemorrhage, we investigated the effects of nicardipine infusion on intracranial pressure (ICP), middle cerebral arterial blood flow velocity (Vmca) , and computed tomographical (CT) findings of bleeding and edema. METHODS: Twenty-two patients with acute cerebral hemorrhage were infused with nicardipine for > 72 hr to decrease blood pressure. Blood pressure, heart rate, conscious level, Vmca, pulsatility index (PI, using transcranial Doppler), ICP, cerebral perfusion pressure (CPP) and platelet counts were monitored. CT examination was also performed to detect the changes of bleeding (hematoma) and/or brain edema. RESULTS: Blood pressure decreased (20 to 30% from control, P < 0.05) without any changes in heart rate. Platelet count did not change neither did Vmca and PI change on either the intact or injured side. The ICP decreased 24 hr after the end of infusion from 30 +/- 12 mmHg to 20 +/- 9 mmHg (P = 0.036) but was still higher than normal. The CPP decreased at 24 hr (75 +/- 14 mmHg, P = 0.026) and 72 hr (73 +/- 15 mmHg, P = 0.024) from the baseline (99 +/- 17 mmHg). Conscious level improved but not significantly and CT findings did not show any exacerbation in bleeding or edema. CONCLUSION: In patients with acute cerebral hemorrhage, nicardipine infusion to decrease blood pressure by 20 to 30% had no effect on Vmca, ICP, cerebral bleeding and edema, but decreased CPP.

Aged↗
PubMed2000

"Deep-forehead" temperature correlates well with blood temperature.

PURPOSE: To evaluate the accuracy and precision of "deep-forehead" temperature with rectal, esophageal, and tympanic membrane temperatures, compared with blood temperature. METHODS: We studied 41 ASA physical status 1 or 2 patients undergoing abdominal and thoracic surgery scheduled to require at least three hours. "Deep-forehead" temperature was measured using a Coretemp thermometer (Terumo, Tokyo, Japan). Blood temperature was measured with a thermistor of a pulmonary artery. Rectal, tympanic membrane, and distal esophageal temperatures were measured with thermocouples. All temperatures were recorded at 20 min intervals after the induction of anesthesia. We considered blood temperature as the reference value. Temperatures at the other four sites were compared with blood temperature using correlation, regression, and Bland and Altman analyses. We determined accuracy (mean difference between reference and test temperatures) and precision (standard deviation of the difference) of 0.5 degrees C to be clinically acceptable. RESULTS: "Deep-forehead" temperature correlated well with blood temperature as well as other temperatures, the determination coefficients (r2) being 0.85 in each case. The bias for the "deep-forehead" temperature was 0.0 degrees C, which was the same as tympanic membrane temperature and was smaller than rectal and esophageal temperatures. The standard deviation of the differences for the "deep-forehead" temperature was 0.3 degrees C, which was the same as rectal temperature. CONCLUSIONS: We have demonstrated that the "deep-forehead" temperature has excellent accuracy and clinically sufficient precision as well as other three core temperatures, compared with blood temperature.

Aged↗
PubMed2000

Slow recovery of goldfish retinal ganglion cells' soma size during regeneration.

The goldfish optic nerve regenerates after sectioning. Recently both short-term (30 days) and long-term (4 months) recovery of various goldfish behaviors were observed after optic nerve section. Using intracellular injection of Lucifer Yellow (LY) the morphology of regenerating ganglion cells in goldfish retina after optic nerve section over a 4 month period have been investigated. In normal retinas, most cells (96-98%) were 7-10 microm in soma diameter which increased with increasing distance from the optic disc. Only two or three short, thin processes could be traced with LY. The remaining cells (2-4%) were 13-16 microm in soma diameter and all of the long dendritic trees could be traced with LY. The most conspicuous morphological change observed was cellular hypertrophy, which occurred for 20-90 days after axotomy. Neuronal processes were also hypertrophic in this period. The percentage increase in hypertrophy of the central ganglion cells tended to be slightly higher compared to cells from other regions. These morphological changes peaked at 60 days after axotomy and fully disappeared by 120 days after axotomy. The slow recovery of ganglion cells' soma size may reflect the slow return to the normal number of optic axon terminals in the tectum during regeneration.

Animals↗
PubMed2000

Effects of aging on cardiovascular responses to gravity-related fluid shift in humans.

BACKGROUND: Fluid shift induced by postural change causes autonomic neural responses of the cardiovascular system that buffer blood pressure fluctuation. The aim of the study was to clarify the effects of aging on cardiovascular autonomic functions in response to gravity-related fluid shift that unloads or loads the baroreceptors in human subjects. METHODS: A chest electrocardiogram, blood pressure by Finapres, and stroke volume by impedance method were measured in healthy young men (23-31 years old) and healthy elderly men (74-80 years old) during supine rest, at 90 degrees head-up tilt and thermoneutral head-out water immersion. Spectral analysis was applied to the time series data of the R-R intervals (heart rate variability [HRV]) and systolic blood pressure (blood pressure variability [BPV]). The arterial baroreflex gain for heart rate was estimated using frequency transfer function analysis. RESULTS: The young subjects had stable blood pressure, despite the larger amount of fluid shift induced by both tilt and immersion, and had marked changes in HRV and BPV. The elderly subjects failed to maintain stable blood pressure during these perturbations, despite less fluid shift and no significant changes in HRV and BPV. The arterial baroreflex gain for heart rate was not changed in the elderly subjects, whereas the gain decreased with upright in the young subjects and showed an increasing tendency during immersion compared with upright posture. CONCLUSIONS: These findings suggest that the adaptivity of the autonomic nervous system to gravity-related fluid shift is reduced in elderly people, and this may cause blood pressure instability.

Adult↗
PubMed2000

Comparison of infrared thermometer with thermocouple for monitoring skin temperature.

OBJECTIVE: To test the hypothesis that the infrared thermometer (Genius) is comparably useful with thermocouples that are routinely used for skin temperature monitoring. DESIGN: Prospective, controlled, not blinded study. SETTING: Operating room of a university hospital. SUBJECTS: Ten healthy male volunteers. INTERVENTIONS: Volunteers were minimally clothed and were initially warmed by a forced air warmer until they became vasodilated at the finger and the foot for approximately 30 mins. Subsequently, they were kept in the room with no blanket. MEASUREMENTS AND MAIN RESULTS: Skin temperatures were measured continuously with the Mon-a-Therm thermocouple and were also measured with the Genius thermometer just before and after the warming and subsequently every 10 mins for 70 mins. Forearm and finger-tip skin temperatures and skin-surface temperature gradients (from arm to finger and from calf to toe) measured by the Genius thermometer were compared with those measured by the Mon-a-Therm thermocouple using linear regression and Bland and Altman statistics. Forearm temperature and finger-tip temperature ranged from approximately 31 degrees to approximately 36.5 degrees C (87.8-97.7 degrees F) and approximately 22.5 degrees to approximately 36 degrees C (72.5-96.8 degrees F), respectively. Gradients (from arm to finger and from calf to toe) ranged from approximately -3 degrees to approximately 10 degrees C (26.6-50.0 degrees F) and approximately -3 degrees to approximately 11 degrees C (26.6-51.8 degrees F), respectively. Correlations between the temperatures measured by the Genius thermometer and those by the Mon-a-Therm thermocouple were similar and reliable. The correlation coefficients were as follows: 0.78 at forearm, 0.97 at finger-tip, and 0.97 at skin-surface temperature gradients. CONCLUSIONS: The infrared thermometer with a special probe is useful to measure the change of skin-surface temperatures and to evaluate the severity of shock in patients.

Adult↗
PubMed2000

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.

Adult↗
PubMed2000

Induction of N-hydroxycinnamoyltyramine synthesis and tyramine N-hydroxycinnamoyltransferase (THT) activity by wounding in maize leaves.

Both N-p-coumaroyl- and N-feruloyltyramine accumulated in response to wounding in leaf segments of maize. The amount of N-hydroxycinnamoyltyramines started to increase 3-6 h after wounding and peaked at 12 h. Thereafter, the amount of N-p-coumaroyltyramine decreased rapidly, while the N-feruloyltyramine content remained at a high level. The accumulation of N-hydroxycinnamoyltyramines was accompanied by an increase in the tyramine N-hydroxycinnamoyltransferase (THT) activity. This increase was initially detected 3 h after wounding and reached a maximum at 36 h, the level of activity being 40 and 11 times that in the leaves before wounding and in the control leaves, respectively. Partial purification of THT from wounded leaves by (NH4)2SO4 precipitation and subsequent two steps of anion-exchange chromatography resulted in a 12.5-fold increase in specific activity. Kinetic studies with this partially purified enzyme revealed that the best substrates were tyramine and feruloyl-CoA, although tryptamine and sinapoyl-CoA also efficiently served as substrates. The apparent native molecular weight of the enzyme was determined by gel filtration as 40 kDa.

Acyltransferases↗
PubMed2000

Assessment of the metabolic chiral inversion of D-leucine in rat by gas chromatography-mass spectrometry combined with a stable isotope dilution analysis.

The stereoselective pharmacokinetics of leucine enantiomers in rats has been investigated to evaluate the inversion of D-leucine to L-enantiomer. After a bolus i.v. administration of D- or L-[2H7]leucine to rats, blood samples were obtained over 6 h after administration and analyzed by a stereoselective gas chromatography-mass spectrometry method. Racemic [2H3]leucine was used as an internal standard. The method involved methyl esterification and subsequent chiral derivatization with (+)-alpha-methoxy-alpha-trifluoromethylphenylacetyl chloride to form the diastereomeric amide. The derivatization made possible the separation of leucine enantiomers with good gas chromatographic behavior. Plasma concentration of both D- and L-[2H7]leucine declined biexponentially, with elimination half-lives of 60 and 14 min, respectively. In contrast to the L-enantiomer, the D-enantiomer had a lower systemic clearance. When D-[2H7]leucine was administered, the L-enantiomer was found to rapidly appear in plasma. About 30% of an administered dose of the D-isomer was stereospecifically inverted to the L-enantiomer. There was no measurable inversion of the L- to D-enantiomer. This methodology has made it possible to evaluate the pharmacokinetics of each enantiomer of amino acids and estimate of chiral inversion after administration of D-amino acids.

Animals↗
PubMed2000

[Use of modified infrared aural canal thermometers during cardiac surgery].

Two kinds of modified infrared aural canal thermometers (Mimippi, Superthermo) are currently available in Japan. We therefore evaluated their accuracy and precision for clinical use. For the purpose of this investigation, we considered accuracy to be the mean difference between the test thermometers and the reference thermocouple. Precision was examined from the standard deviation of the difference between the test and reference values. We evaluated ten patients for cardiopulmonary bypass surgery under mild hypothermia (approximately 32 degrees C). Aural canal temperatures were measured in a random order with each infrared thermometer, and compared with readings from a thermocouple positioned at the contralateral tympanic membrane. Compared with the thermocouple, the Mimippi had regression slope 0.87 and correlation coefficient 0.79. In contrast, slope of the Superthermo regression was 0.74. The correlation coefficient for the Superthermo was 0.71. The accuracy (offset, or bias) was 0.91 degree C with the Mimippi. In contrast, it was 1.32 degrees C with the Superthermo. The precision (standard deviation) of the Mimippi was 0.65. In contrast, it was 0.73 degree C with the Superthermo. We conclude that both thermometers were moderately accurate and precise for perioperative use.

Body Temperature↗