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Biomedical subjects

Shigeru Saito

Publications and source records attributed to Shigeru Saito.

At least 19 recordsLinked to original sources
PubMed2003

Cadmium exposure and trace elements in human breast milk.

The interrelations of the seven elements, calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), phosphorus (P), copper (Cu), zinc (Zn), and cadmium (Cd) in human breast milk were examined in Japanese mothers to clarify the effects of Cd exposure on these important elements for infant growth. Breast milk and urine samples were obtained from 68 mothers, aged 19-38 years, at 5-8 days postpartum. The concentrations were determined by inductively-coupled plasma atomic emission spectrometry for Ca, Mg, Na, K, P, by flame atomic absorption spectrophotometry for Cu and Zn, and by flameless atomic absorption spectrophotometry for Cd. Geometrical mean Cd concentrations were 0.28 (geometrical standard deviation=1.82) microg/l in breast milk and 1.00 (1.93) microg/g creatinine in urine. Among the above elements only Cd concentration in breast milk was significantly correlated with urinary Cd concentration (r=0.451, P<0.001). Significant positive correlations were found between Cu and Ca (r=0.500, P<0.001), Cu and Mg (r=0.378, P<0.01), and Zn and Mg (r=0.355, P<0.01) in breast milk. Cd concentration in breast milk showed an inverse relationship with Ca concentration in breast milk (r=-0.248, P<0.05). These results indicate that the Cd concentration in breast milk closely reflects Cd body burden, with increased Cd in breast milk possibly affecting Ca secretion in breast milk.

Adult↗
PubMed2003

Interactions of 5-HT2 receptor agonists with acetylcholine in spinal analgesic mechanisms in rats with neuropathic pain.

Serotonin type 2 (5-HT(2)) receptors reportedly inhibit neuropathic pain in the spinal cord, but little is known about how spinal 5-HT(2) receptors might act against such abnormal sensitivity. We examined whether the cholinergic and tachykinin systems were involved in the antiallodynic effect of intrathecally administered 5-HT(2) receptor agonists in rats with nerve injury. Allodynia was produced by tight ligation of the left L5 and L6 spinal nerves, and determined by applying von Frey hairs to the left hindpaw. Effects of intrathecal pretreatment with 5-HT(2) receptor antagonists (ketanserin and RS-102221), muscarinic receptor antagonists (atropine and scopolamine), a choline uptake blocker (hemicholium-3), and an NK(1) receptor antagonist (L-706336) were assessed in rats subsequently given a 100- micro g intrathecal dose of a 5-HT(2) receptor agonist either alpha-methyl-5-HT or iododimethoxy aminopropane (DOI). Antiallodynic effects of 5-HT(2) receptor agonists were attenuated by the 5-HT(2A) receptor antagonist ketanserin (30 micro g), but not by the 5-HT(2C) receptor antagonist RS-102221 (40 micro g). Muscarinic receptor antagonists (30 micro g each), the choline uptake blocker (10 micro g), and the NK(1) receptor antagonist (30 micro g) also inhibited the antiallodynic effects of 5-HT(2) receptor agonists. Antiallodynic effects of intrathecally administered 5-HT(2) receptor agonists may be mediated by spinal release of acetylcholine induced via 5-HT(2A) and NK(1) receptors.

Acetylcholine↗
PubMed2003

Comparative study on transradial approach vs. transfemoral approach in primary stent implantation for patients with acute myocardial infarction: results of the test for myocardial infarction by prospective unicenter randomization for access sites (TEMPURA) trial.

Transradial coronary intervention (TRI) can be performed in elective patients with low incidence of access site complications. However, the feasibility of primary stent implantation by TRI is still not clear in patients with acute myocardial infarction (AMI). We prospectively randomized 149 patients out of 213 patients with AMI within 12 hr from onset into two groups: 77 patients treated by TRI (TRI group) and 72 patients by transfemoral coronary intervention (TFI; TFI group). We compared the incidences of major adverse cardiac events (MACE; repeat MI, target lesion revascularization, and cardiac death) during the initial hospitalization and 9-month follow-up periods in both groups. There were one patient who crossed over to the opposite arm, and two patients with severe bleeding complications in the TFI group. Background characteristics of patients were similar between the two groups. The success rate of reperfusion and the incidence of in-hospital MACE were similar in both groups (96.1% and 5.2% vs. 97.1% and 8.3% in TRI and TFI groups, respectively). In selected patients with AMI, primary stent implantation by TRI is feasible as compared to TFI.

Aged↗
PubMed2003

Angioplasty for chronic total occlusion by using tapered-tip guidewires.

Percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) is still technically challenging. The use of tapered-tip guidewires in these lesions may improve the success rate of PCI. In order to avoid the needless radiation exposure or contrast consumption, we have to determine a guideline for the termination of procedures in these lesions. We retrospectively analyzed the data of 182 patients between April 1997 and December 1999 (phase 1) and 80 patients between January and August 2001 (phase 2) who underwent angioplasty for CTO lesions >/= 3 months. There were no significant differences in clinical or lesion characteristics except the use of tapered-tip guidewires. Tapered-tip guidewires were used in 60% of patients in phase 2 period but no patients in phase 1 period. The overall success rate of PCI was improved from 67% in phase 1 to 81% in phase 2 (P = 0.019). In the phase 2 period, the success rate was higher in tapered-type occlusion (P = 0.002) and shorter length of occlusion (P = 0.004). Total procedure time was 46 +/- 17 min and total volume of contrast dye was 180 +/- 63 ml. The success rate was higher in patients treated by transradial coronary intervention (TRI) than transfemoral coronary intervention (89% vs. 64%; P = 0.008). The use of tapered-tip guidewires can improve the success rate of PCI in CTO lesions. The following guideline for the termination of the procedures is reasonable: time from arterial access to successful penetration of a guidewire through occlusion </= 30 min; total procedure time </= 90 min; and total dye volume </= 300 ml. TRI can achieve a high success rate even in CTO lesions provided that the case selection is adequate.

Aged↗
PubMed2003

Epidural abscess in a patient with dorsal hyperhidrosis.

PURPOSE: To report the management of a patient who developed a lumbar epidural abscess when an epidural catheter was placed three years after a thoracic sympathectomy. The possible contribution of hyperhidrosis is discussed. CLINICAL FEATURES: A 62-yr-old male had compensatory hyperhidrosis in his back after thoracic sympathectomy. The patient, who suffered from thromboangeitis obliterans, underwent lumbar (L2-3) epidural catheterization in order to improve arterial circulation and ameliorate resting pain in his left leg. On the third day after catheterization, the patient complained of a dull pain in his back. Emergency magnetic resonance imaging revealed a 12-mm abscess in the epidural space. On the tenth day after catheterization, laminotomy at the 3-4 lumbar vertebrae and local drainage were performed. A 14-mm abscess was removed from the epidural space. The patient was discharged on day 21 after catheterization without any disability. CONCLUSION: Special precautions against infection may be necessary in patients with hyperhidrosis in the area where continuous epidural catheterization is attempted.

Anesthesia, Epidural↗
PubMed2003

Comparative effects of propofol versus fentanyl on cerebral oxygenation state during normothermic cardiopulmonary bypass and postoperative cognitive dysfunction.

BACKGROUND: The purpose of this study was to examine the comparative effects of propofol and fentanyl on cerebral oxygenation during normothermic cardiopulmonary bypass and postoperative cognitive dysfunction. METHODS: One hundred eighty patients scheduled for elective coronary artery bypass grafting were randomly divided into two groups: propofol group (n = 90) and fentanyl group (n = 90). After induction of anesthesia, a fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb to monitor jugular venous oxygen hemoglobin saturation continuously. Hemodynamic measurements and arterial and jugular venous blood gases were measured at seven time points. All patients underwent a battery of neurologic and neuropsychological tests on the day before the operation and at 6 months after the operation. RESULTS: Cerebral desaturation (defined as a jugular venous oxygen hemoglobin saturation value less than 50%) during cardiopulmonary bypass was more frequent in the fentanyl group than in the propofol group. Cerebral desaturation time (duration when jugular venous oxygen hemoglobin saturation was less than 50%) and the ratio of cerebral desaturation time to total cardiopulmonary bypass time in the fentanyl group differed significantly from those in the propofol group (fentanyl group: 27 +/- 14 minutes, 20% +/- 9%; propofol group: 18 +/- 11 minutes, 14% +/- 7%, respectively, p < 0.05). There was no significant difference in postoperative cognitive dysfunction at 6 months after operation between the two groups (propofol group: 5 of 77, 6%; fentanyl group: 5 of 75, 7%). CONCLUSIONS: Propofol preserved cerebral oxygenation state estimated by jugular venous oxygenation during cardiopulmonary bypass compared with the fentanyl group. However, propofol did not affect postoperative cognitive dysfunction.

Aged↗
PubMed2003

The preterm labor index and fetal fibronectin for prediction of preterm delivery with intact membranes.

OBJECTIVE: To compare the preterm labor index with the biochemical marker fetal fibronectin in predicting preterm delivery. METHODS: In 185 women with preterm labor and intact membranes, the preterm labor index was determined based on clinical findings of uterine contractions, bleeding, and cervical dilatation. An immunosorbent assay was used to measure oncofetal fibronectin. RESULTS: A significant negative correlation was noted between the preterm labor index and the interval from hospitalization to delivery. Based on a receiver operating characteristic curve, a preterm labor index 4 or higher was defined as positive. Rates of preterm delivery overall and of delivery within 1 week in the preterm labor index-negative group were 55.2% and 13.8%, respectively. Those in the preterm labor index-positive group were significantly higher (88.4% and 56.5%). With respect to predicting when a delivery would occur during the first week of hospitalization, the preterm labor index and fetal fibronectin did not differ in sensitivity (77.7% and 73.8%, respectively), specificity (79.5% and 74.2%), positive predictive value (66.7% and 60.8%), or negative predictive value (84.5% and 83.9%). However, within the preterm labor index-negative group, the rates of preterm delivery (68.4%), delivery within 1 week (28.9%), and neonatal treatment in an intensive care unit (36.8%) were significantly higher in fetal fibronectin-positive than in fibronectin-negative cases (46.2%, 9.0%, and 10.3%, respectively). CONCLUSION: The preterm labor index was similar to the fetal fibronectin assay in its ability to predict preterm delivery.

Adult↗
PubMed2003

Maternal total parenteral nutrition and fetal subdural hematoma.

BACKGROUND: Fetal subdural hematoma is rare, and no case resulting from vitamin K deficiency secondary to maternal total parenteral nutrition has been reported. CASE: A 28-year-old woman was managed with total parenteral nutrition from 28 weeks' gestation because of continuous vomiting due to esophageal hiatal hernia. A sinusoidal pattern by cardiotocogram was observed at 31 weeks' gestation. Serial sonograms showed a fetal subdural hematoma, and cesarean delivery was performed. Although the maternal hepaplastin test result was normal and the maternal PIVKA-II concentration was only slightly elevated, the neonate was severely anemic and had severe vitamin K deficiency. CONCLUSION: Severe fetal vitamin K deficiency can develop even when the maternal deficiency is mild. When maternal total parenteral nutrition is necessary, supplemental vitamin K should be administered.

Adult↗
PubMed2003

Th1/Th2 balance in preeclampsia.

The syndrome of preeclampsia has previously been ascribed to generalized maternal endothelial dysfunction, poor placentation and excessive maternal inflammatory response. Recent reports suggest that preeclampsia is associated with a Th1 predominant profile and may be considered as a failure of the tolerance system allowing the second physiological trophoblastic invasion. In this review, we discuss that Th1 predominant immunity is closely related to inflammation, endothelial dysfunction and poor placentation.

Endothelium, Vascular↗
PubMed2003

Usefulness of a new radiofrequency thermal balloon catheter for pulmonary vein isolation: a new device for treatment of atrial fibrillation.

INTRODUCTION: A rapidly firing or triggered ectopic focus located within a pulmonary vein (PV) or close to the PV ostium could induce atrial fibrillation (AF). The aim of this study was to evaluate the efficacy and safety of a radiofrequency thermal balloon catheter for isolation of the PV from the left atrium (LA). METHODS AND RESULTS: Twenty patients with drug-resistant paroxysmal AF were treated by isolating the superior PVs using an RF thermal balloon catheter. Using a transseptal approach, the balloon, which had an inflated diameter 5 to 10 mm larger than that of the PV ostium, was wedged at the LA-PV junction. It was heated by a very-high-frequency current (13.56 MHZ) applied to the coil electrode inside the balloon for 2 to 3 minutes, and the procedure was repeated up to four times. The balloon center temperature was maintained at 60 degrees to 75 degrees C by regulating generator output. Successful PV isolation was achieved in 19 of the 20 left superior PVs and in all 20 of the right superior PVs and was associated with a decrease in amplitude of the ostial potentials. Total procedure time was 1.8 +/- 0.5 hours, which included 22 +/- 7 minutes of fluoroscopy time. After a follow-up period of 8.1 +/- 0.8 months, 17 patients were free from AF, with 10 not taking any antiarrhythmic drugs and 7 taking the same antiarrhythmic agent as before ablation. Electron beam computed tomography revealed no complications, such as PV stenosis at ablation sites. CONCLUSION: The PV and its ostial region can be safely and quickly isolated from the LA by circumferential ablation around the PV ostia using a radiofrequency thermal balloon catheter for treatment of AF.

Aged↗
PubMed2003

A free radical initiator, 2,2'-azobis (2-aminopropane) dihydrochloride enhances hyperthermia-induced apoptosis in human uterine cervical cancer cell lines.

Hyperthermia-induced apoptosis and its enhancement in the presence of a temperature-dependent free radical initiator, 2,2'-azobis (2-aminopropane) dihydrochloride (AAPH) were examined in human uterine cervical cancer cell lines, CaSki and HeLa. When both cell lines were treated with hyperthermia at 44 degrees C for 60 min, minimal apoptosis was observed. When combined with nontoxic AAPH (50mM), significant enhancement of apoptosis was observed, where the initial rate of free radical formation was about twice as high than that at 37 degrees C. Augmentation of the growth delay, lipid peroxidation (LPO), activation of caspase-3 and increase in [Ca2+]i were also observed after the combined treatment. A water-soluble vitamin E, Trolox, blocked the increase in [Ca2+]i and an intracellular Ca2+ chelator, BAPTA-AM, prevented the DNA fragmentation induced by the combination. Cytochrome c release was also revealed by fluorescence microscopy. However, no significant change in mitochondrial membrane potential and expression of Bax and Bcl-2 was observed. A slight increase in Fas expression was observed only in CaSki cells after the combined treatment. These results indicate that hyperthermia and AAPH induce enhanced apoptosis and subsequent cell killing via two pathways; a pathway dependenton increase in LPO and [Ca2+]i, and a pathway associated with cytochrome c release and subsequent caspase activation without changes of mitochondrial membrane potential and Bax/Bcl-2 expression in these cell lines. Since it is known that cancer cells are generally resistant to physical and chemical stress-induced apoptosis, free radical generators like AAPH appear to be a useful thermosensitizer for hyperthermic cancer therapy.

Amidines↗
PubMed2003

The effects of volatile anesthetics on nonadrenergic, noncholinergic depressor responses in rats.

UNLABELLED: The effects of volatile anesthetics on nonadrenergic, noncholinergic (NANC) transmission mediated by calcitonin gene-related peptide (CGRP) are unclear. We studied the effects of isoflurane, halothane, and sevoflurane on NANC depressor responses to electrical spinal cord stimulation in pithed rats whose mean arterial blood pressure was maintained near 120 mm Hg by continuous infusion of methoxamine. Autonomic outflow was blocked by hexamethonium. After 30 min of inhalation of different concentrations of anesthetics, spinal cord stimulation at the lower thoracic level (10 V at 4 Hz; duration, 1 ms) was applied for 30 s to induce a NANC depressor response. Isoflurane at 2% and halothane at 1.5% attenuated NANC depressor responses significantly, whereas isoflurane at 1%, halothane at 0.75%, and sevoflurane at 2% or 4% did not. Volatile anesthetics did not attenuate the release of CGRP after spinal cord stimulation, whereas isoflurane at 2% and halothane at 1.5% significantly inhibited depressor responses to exogenously administered CGRP. Sevoflurane at 4% did not significantly affect CGRP-induced depressor responses. Thus, isoflurane and halothane at large concentrations attenuate NANC depressor responses by attenuating the depressor action of CGRP, not CGRP release. IMPLICATIONS: The anesthetics isoflurane and halothane attenuate nonadrenergic, noncholinergic depressor responses mediated by calcitonin gene-related peptide in the rat without affecting the release of the peptide.

Anesthetics, Inhalation↗
PubMed2003

Anesthetic management for clipping a giant basilar artery aneurysm with moderate hypothermia, extracorporeal circulation assistance, and propofol infusion.

A 65-year-old female patient underwent surgery to clip a giant basilar artery aneurysm with closed-chest extracorporeal circulation using femorofemoral bypass. Moderate hypothermia (27 degrees C-30 degrees C), retention of spontaneous circulation, and propofol infusion (3-5 mg. kg(-1). h(-1)) were used under general anesthesia. Blood outflow via femoral vein was sufficient to maintain cardiopulmonary bypass and to induce hypothermia. Hemodynamics were controlled with dopamine and noradrenaline. In this case, extracorporeal circulation under moderate hypothermia was used to assist rather than substitute for spontaneous circulation, and spontaneous circulation was maintained at all times. We think that this method had advantages over deep hypothermic circulatory arrest with regard to intraoperative risks and postoperative complications.

Aged↗
PubMed2003

End-tidal carbon dioxide monitoring stabilized hemodynamic changes during ECT.

Accumulation of carbon dioxide (CO2) can disturb systemic and cerebral hemodynamics in patients receiving electroconvulsive therapy (ECT). The purpose of this study was to identify the effects of end-tidal CO2 monitoring on hemodynamic changes in patients who received ECT under propofol anesthesia. ECT was prescribed to 40 patients under propofol anesthesia. Ventilation was assisted using a face mask and 100% oxygen, with or without end-tidal CO2 monitoring. Heart rate was significantly increased in patients without end-tidal CO2 monitoring at 1 to 5 minutes after electrical stimulation (p < 0.01). Mean arterial blood pressure and middle cerebral artery blood flow velocity in the group without end-tidal CO2 monitoring were significantly larger than the values in the group with the monitor at 1 to 5 minutes after electrical stimulation. Arterial CO2 tension in the group without end-tidal CO2 monitoring was larger than the value in the group with the monitoring at 1 minute (45+/-5 mm Hg with the monitor and 56+/-8 without the monitor) and 5 minutes (37+/-4 mm Hg with the monitor and 51+/-8 without the monitor) after electrical stimulation (p < 0.01). Application of end-tidal CO2 monitoring is considered beneficial for safe and effective anesthesia management of patients undergoing ECT, especially patients with an intracranial disorder or ischemic heart disease.

Adult↗
PubMed2003

Antinociception with intrathecal alpha-methyl-5-hydroxytryptamine, a 5-hydroxytryptamine 2A/2C receptor agonist, in two rat models of sustained pain.

UNLABELLED: Type 2 serotonin (5-hydroxytryptamine [5-HT](2)) receptors in the spinal cord have been reported to mediate antinociception using pain threshold tests, but little is known about the actions of spinal 5-HT(2) receptors in sustained pain. In rats, we examined antinociceptive effects of the intrathecal administration of a 5-HT(2A/2C) receptor agonist, alpha-methyl-5-HT maleate (alpha-m-5-HT), using the formalin test and the chronic constriction injury (CCI) model. An intrathecal catheter was implanted for injection of drugs. In the formalin test, flinches were counted from Minute 1 to 2 and Minute 5 to 6 (Phase 1) and then for 1-min periods at 5-min intervals from 10 to 60 min (Phase 2). In rats with CCI, hind paw withdrawal latency after thermal stimulation was measured. In the formalin test, intrathecal administration of alpha-m-5-HT (1 to 100 microg) dose-dependently suppressed the number of flinches in both Phases 1 and 2. In the CCI model, intrathecally administered alpha-m-5-HT (10 to 100 microg) attenuated thermal hyperalgesia in a dose-dependent manner. These effects were reversed by intrathecal pretreatment with a 5-HT(2A/2C) antagonist, ketanserin (30 microg), or a muscarinic receptor antagonist, atropine (30 microg). These findings suggest that spinal 5-HT(2A/2C) receptors mediate antinociception in inflammatory pain and neuropathic pain, and the muscarinic receptors contribute to this action. IMPLICATIONS: Activation of spinal 5-hydroxytryptamine(2A/2C) receptors mediate antinociception in rat-sustained pain models such as inflammatory pain and neuropathic pain, and spinal muscarinic receptors are involved in this action.

Animals↗