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Biomedical subjects

Shigeru Saito

Publications and source records attributed to Shigeru Saito.

At least 91 records · Page 5Linked to original sources
PubMed2004

Jugular venous oxygen saturation during mild hypothermic versus normothermic cardiopulmonary bypass in elderly patients.

PURPOSE: Age is known to be a major risk factor for adverse postoperative cognitive dysfunction after cardiac surgery. We conducted this study to determine if jugular venous oxygen saturation (SjvO(2)) differed during mild hypothermic (32 degrees C) and normothermic cardiopulmonary bypass (CPB) in elderly patients. METHODS: Sixty patients aged over 70 years who underwent elective coronary artery bypass grafting were randomly divided into two groups. Group 1 ( n = 30) underwent normothermic CPB (>35 degrees C) and group 2 ( n = 30) underwent mild hypothermic CPB (32 degrees C). For the continuous monitoring of SjvO(2), a fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb after the induction of anesthesia. Hemodynamic parameters, and arterial and jugular venous blood gases were measured at seven time points. RESULTS: The SjvO(2) in the normothermic group was lower at the onset of CPB and 20 min after the onset, than from the time of induction of anesthesia until the start of surgery (period 1), the respective SjvO(2) values being 50.3% +/- 1.0%, 50.1% +/- 1.6%, and 59.5% +/- 1.9% ( P < 0.05). However, in the mild hypothermic group there were no changes in the SjvO(2) value throughout the study. The cerebral desaturation time (when the SjvO(2) value was <50%) and the ratio of the cerebral desaturation time to the total CPB time in the normothermic group differed significantly from those in the hypothermic group, being 19 +/- 11 min and 17% +/- 10%, and 9 +/- 3 min and 8% +/- 4%, respectively ( P < 0.05). CONCLUSIONS: The SjvO(2) value was better during mild hypothermic CPB than during normothermic CPB in elderly patients.

Aged↗
PubMed2004

Cerebrovascular carbon dioxide reactivity with propofol anesthesia in patients with previous stroke.

STUDY OBJECTIVE: To examine whether patients with previous stroke have impaired cerebrovascular carbon dioxide (CO2) reactivity when receiving propofol anesthesia. DESIGN: Prospective, controlled study. SETTING: University hospital. PATIENTS: 34 consecutive patients, 17 of whom had previous stroke and were scheduled for elective cardiac surgery, and 17 control age-matched patients without previous stroke who were also scheduled for cardiac surgery. INTERVENTIONS: Anesthesia was induced and a 2.5-MHz pulsed transcranial Doppler probe was attached to the patient's head at the right temporal window. Mean blood flow velocity of the middle cerebral artery (Vmca) was measured continuously. MEASUREMENTS: After establishing baseline Vmca, arterial blood gases and cardiovascular hemodynamic values, partial pressure of end-tidal CO2 (PETCO2) was increased by changing the ventilatory frequency by 2 to 5 breaths/min. The measurements were repeated when PETCO2 increased and remained stable for 5 to 10 minutes. MAIN RESULTS: Values for absolute CO2 reactivity in the control patients and in those with previous stroke were 2.6 +/- 0.5 and 2.9 +/- 0.7 cm/sec/mmHg, respectively, a nonsignificant difference in these values. Values for relative CO2 reactivity in control patients and in patients with previous stroke were 6.4 +/- 1.4 and 6.1 +/- 1.4%/mmHg, respectively, with no significant difference noted. CONCLUSIONS: Cerebrovascular CO2 reactivity in patients with previous stroke is normal during propofol anesthesia.

Anesthetics, Intravenous↗
PubMed2004

The ratio of interleukin (IL)-18 to IL-12 secreted by peripheral blood mononuclear cells is increased in normal pregnant subjects and decreased in pre-eclamptic patients.

Interleukin (IL)-18 acts in synergy with IL-12 to promote development of T helper 1 (Th1) responses. On the other hand, IL-18 alone has the capacity to induce Th2 responses. Here, we have measured IL-18 and IL-12 secretion by non-stimulated peripheral blood mononuclear cells (PBMC) from 17 non-pregnant women, 21 healthy pregnant women, 9 mildly pre-eclamptic patients and 15 severely pre-eclamptic patients. Th1/Th2 ratios in PBMC were determined by flow cytometry. PBMC from healthy pregnant subjects secreted more IL-18 and less IL-12 than non-pregnant women. PBMC from severely pre-eclamptic patients secreted more IL-12 than those from healthy pregnant women, while IL-18 secretion in mildly pre-eclamptic patients resembled that in normal pregnancy. The ratios of IL-18 to IL-12 were significantly higher in healthy pregnant women than non-pregnant women. These ratios were significantly lower in severely pre-eclamptic cases than in normal pregnancy subjects, while these ratios in mild pre-eclampsia resembled those in normal pregnancy. Interestingly, Th1/Th2 ratios were negatively correlated with the ratios of IL-18/IL-12. These results suggest that elevated IL-18 secretion and decreased IL-12 secretion by PBMC may induce Th2 dominance in normal pregnancy, while elevated secretion of both IL-18 and IL-12 by PBMC may cause Th1 dominance in severe pre-eclampsia.

Biomarkers↗
PubMed2004

Antiallodynic effects of intrathecally administered 5-HT(2C) receptor agonists in rats with nerve injury.

Intrathecal administration of serotonin type 2 (5-HT(2)) receptor agonists, alpha-methyl-5-hydroxytryptamine maleate (alpha-m-5-HT) or (+/-)-1-(4-iodo-2,5-dimethoxyphenyl)-2-aminopropane hydrochloride (DOI), produces antiallodynic effects in a rat model of neuropathic pain. In the present study, we examined the antiallodynic effects of intrathecally administered agents which are selective for 5-HT(2C) receptors. Allodynia was produced by tight ligation of the left L5 and L6 spinal nerves, and was measured by applying von Frey filaments to the left hindpaw. Administration of the 5-HT(2C) receptor agonist, 6-chloro-2-(1-piperazinyl)-pyrazine (MK212; 3-100 microg), 1-(m-chlorophenyl)-piperazine (mCPP; 30-300 microg), or 1-(m-trifluoromethylphenyl)-piperazine (TFMPP; 30-300 microg), produced antiallodynic effects in a dose-dependent manner with no associated motor weakness. The ED(50) values of MK212, mCPP, and TFMPP were 39.2, 119.9, and 191.9 microg, respectively. Intrathecal pretreatment with the selective 5-HT(2C) receptor antagonist RS-102221 (30 microg) diminished the effects of the highest doses of 5-HT(2C) receptor agonists. The preferential 5-HT(2A) receptor antagonist ketanserin (30 microg) did not reverse the effects. In contrast to 5-HT(2C) receptor agonists, the antiallodynic effects of intrathecally administered alpha-m-5-HT (30 microg) and DOI (100 microg) were reversed by ketanserin, but not by RS-102221. These results indicate that 5-HT(2C) receptors have a role in spinal inhibition of neuropathic pain, and the effects produced by intrathecal administration of 5-HT(2C) receptor agonists are mediated by a mechanism different from that of alpha-m-5-HT or DOI, which seem to produce their effects through 5-HT(2A) receptors.

Amphetamines↗
PubMed2004

Cerebral metastasis from a primary adenocarcinoma of the fallopian tube.

BACKGROUND: Primary adenocarcinoma of the fallopian tube is a rare disease, and cerebral metastasis from this tumor is an extremely rare event. CASE: A 61-year-old female, who had been thought to be in a disease-free state after the initial treatment for stage IIIc fallopian tube adenocarcinoma, presented with severe headache, dizziness, nausea, and vomiting. Brain CT and MRI revealed solitary metastatic lesion in the cerebrum, which was the only site of recurrence. It was removed surgically, followed by platinum-based combination chemotherapy, and a clinical remission was achieved for 36 months. CONCLUSION: Attention should be paid to the possibility of cerebral metastasis in patients who develop neurogenic signs and symptoms. Prolonged survival could be achieved with aggressive treatment containing surgical debulking and adjuvant chemotherapy for solitary cerebral metastasis.

Adenocarcinoma↗
PubMed2004

Elevated interleukin-8 in cervical mucus as an indicator for treatment to prevent premature birth and preterm, pre-labor rupture of membranes: a prospective study.

PROBLEM: We investigated whether cervical shortening and high interleukin (IL)-8 in cervical mucus were valuable indications for treatment to prevent premature birth and preterm, pre-labor rupture of membranes (pPROM). METHOD OF STUDY: Pregnant women were divided into group A, in which neither cervical IL-8 nor cervical length was measured in the middle trimester; and groups B and C, in which cervical length and cervical IL-8 were measured, and bed rest or cerclage was performed when cervical shortening was detected. In group B, vaginal washing with povidone iodine and insertion of chloramphenicol vaginal tablets were carried out in women with IL-8 elevations. RESULTS: In group B, duration of pregnancy was significantly prolonged compared with group A and C, and occurrence of pPROM was significantly lower. No significant differences were found in those rates between groups A and C. CONCLUSION: Successful treatment for women with IL-8 elevations in cervical mucus decreased rates of premature birth or pPROM.

Cervix Mucus↗
PubMed2004

Relationship between cervical mucus interleukin-8 concentrations and vaginal bacteria in pregnancy.

PROBLEM: High interleukin (IL)-8 concentration in cervical mucus in the second trimester is a risk factor for premature birth. We investigated the relationship between vaginal pathogens and IL-8 in cervical mucus. METHOD OF STUDY: In 501 women with single pregnancy, vaginal secretions were cultured for bacteria and cervical mucus IL-8 concentrations were measured between 20 and 24 gestational weeks. RESULTS: Lactobacillus species were detected in 56.0% of 84 subjects with high IL-8 (> or =377 ng/mL), significantly less often than in 417 subjects with IL-8 below 377 ng/mL (84.7%; P < 0.0001). Anaerobic pathogens were detected in 83.3% of high IL-8 subjects, significantly more often than in normal IL-8 subjects (43.9%; P < 0.0001). By multivariate analysis, cervical IL-8 was significantly high only in subjects without Lactobacillus species; they showed a significantly higher prematurity rate than Lactobacillus-positive subjects. CONCLUSIONS: Absence of vaginal Lactobacilli was associated with increased cervical IL-8 and increased risk of premature delivery.

Adult↗
PubMed2004

Matrix Gla protein is associated with coronary artery calcification as assessed by electron-beam computed tomography.

Matrix Gla protein (MGP) is an extracellular matrix protein with wide tissue distribution. It has been demonstrated that the expression of MGP is detected not only in the normal blood vessels but also calcified atherosclerotic plaques, and that MGP deficient mice develop extensive arterial calcification. MGP is thought to be a regulator of vascular calcification. A recent clinical study demonstrates the association between polymorphisms of the MGP gene and increased risk of myocardial infarction. However, there are no reports of the relationship between serum MGP levels and coronary artery calcification (CAC). We evaluated the severity of CAC using electron-beam computed tomography (EBCT), and measured serum MGP levels by enzyme-linked immunosorbent assay in 115 subjects with suspected coronary artery disease. CAC scores were correlated with traditional risk factors, such as age, gender, hyper-tension, diabetes, hyperlipidemia and smoking. The serum MGP levels were lower in patients with CAC than in those without CAC (p<0.001). As the severity of CAC increased, there was a significant decrease in serum MGP levels. Serum MGP levels (U/L) were 116.7 +/- 20.3, 104.9 +/- 19.2, 95.2 +/- 15.2 and 82.2 +/- 19.7, (medians 115.5, 105.0, 94.8, and 81.9) for the subjects with normal (CAC score=0), mild (CAC score=1 to 99), moderate (CAC score=100 to 400), and severe (CAC score >400) coronary calcification, respectively. We found that serum MGP levels are inversely correlated with the severity of CAC. These data suggest a possible role for MGP in the development of vascular calcification.

Aged↗
PubMed2004

Intracellular calcium increases in growth cones exposed to tetracaine.

UNLABELLED: Neurotoxicity of local anesthetics has been reported for both matured and growing neurons. In the present study, we examined if tetracaine increases Ca(2+) concentration during growth cone collapse. Intracellular Ca(2+) concentration was measured by fura 2/AM after exposure to tetracaine. Tetracaine (1-2 mM) induced increases in intra-growth cone Ca(2+) concentration (P < 0.01). The Ca(2+) hot spot was expanded into the neurite from the periphery towards the cell body. When tetracaine was applied to growth cones in Ca(2+) free media, the increase was minor. However, tetracaine induced growth cone collapse even in the culture media, which did not contain Ca(2+). Ni(2+) (100 microM; a general Ca(2+) channel inhibitor) and BAPTA-AM (5 microM; intracellular Ca(2+) chelator) could not inhibit growth cone collapse induced by 1-2 mM tetracaine. Tetracaine (>1 mM) induces collapse and Ca(2+) increase at growth cones simultaneously; however, these two phenomena might be provoked independently. IMPLICATIONS: Tetracaine induced intracellular Ca(2+) increases and growth cone collapse in dorsal root ganglion neurons. The Ca(2+) hot spot in the growth cone expanded into the neurite from periphery towards the cell body.

Anesthetics, Local↗
PubMed2004

Pilot study of the effects of ONO-5046 in patients with acute respiratory distress syndrome.

Evidence has linked neutrophil elastase to acute respiratory distress syndrome (ARDS), suggesting that inhibiting the activity of this enzyme could prevent the development and progression of ARDS. However, few clinical trials have examined this notion. We therefore examined the effects of ONO-5046 (sivelestat, a specific inhibitor of neutrophil elastase; sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylaminobenzoyl]amino-acetate tetrahydrate]) in a randomized, double-blinded trial in patients with ARDS. We randomly assigned 24 patients with ARDS to groups that received conventional therapy without or with sivelestat (0.2 mg. kg(-1). h(-1)) for 14 days. The variables of interest associated with clinical outcome were the duration of mechanical ventilation; changes in oxygenation from baseline; changes in cytokine levels from baseline; number of patients alive at 30 days who did not need mechanical ventilation; and mortality rate. The length of intensive care unit stay, number of ventilation days, and mortality rates did not statistically differ between groups. ARDS was more persistent in the control than in the sivelestat group (control, 19.5 +/- 7.4 days; sivelestat, 13.5 +/- 5.9 days; P = 0.039). Neutrophil elastase activity significantly differed between groups at 72 h after treatment. Levels of interleukin-6 were lower in the sivelestat group than in the controls at 24, 48, and 72 h after treatment. ONO-5046 apparently did not affect survival or the duration of mechanical ventilation.

Adult↗
PubMed2004

The effect of diabetes on the interrelationship between jugular venous oxygen saturation responsiveness to phenylephrine infusion and cerebrovascular carbon dioxide reactivity.

In this study, we examined whether cerebrovascular carbon dioxide (CO(2)) reactivity was related to the response of jugular venous oxygen saturation (SjvO(2)) to phenylephrine infusion in diabetic patients during cardiopulmonary bypass. Forty diabetic patients scheduled for coronary artery bypass graft surgery were studied, and 40 age-matched nondiabetic cardiopulmonary bypass patients served as controls. Cerebrovascular CO(2) reactivity was measured continuously using transcranial Doppler. Mean arterial blood pressure (MAP) was increased by repeated phenylephrine infusion until reaching 100% of baseline values. There was a significant difference in absolute CO(2) reactivity between the diabetic and control groups (controls, 2.8 +/- 0.7 cm. s(-1). mm Hg(-1); diabetics, 2.2 +/- 1.1 cm. s(-1). mm Hg(-1); P = 0.02). Among the diabetics, absolute CO(2) reactivity in insulin-dependent patients was less than that in noninsulin-dependent patients (diet therapy group, 3.2 +/- 0.7; glibenclamide group, 2.6 +/- 0.7; insulin-dependent group, 1.0 +/- 0.7; P < 0.01). There was a correlation between absolute CO(2) reactivity and the mean slope of SjvO(2) versus MAP for increasing MAP (r = 0.54; P < 0.0001). In conclusion, we found that the interrelationship between SjvO(2) responsiveness to phenylephrine infusion and cerebrovascular CO(2) reactivity, as well as impaired cerebrovascular autoregulation, were associated with previous hyperglycemia.

Aged↗
PubMed2004

Relationship between newborn size and mother's blood cadmium levels, Toyama, Japan.

The effect of blood cadmium (Cd), which reflects not only Cd body burden but also recent Cd exposure and communicates with fetal blood in the placenta, on newborn size at birth was investigated. Blood Cd of 55 mothers from Toyama, Japan, at 30-32 gestational weeks was measured using a flameless atomic absorption spectrophotometer. The relationship between blood Cd and newborn size was analyzed after adjustment for gestational age and maternal build. A significant inverse correlation was found between infant height and maternal blood Cd. After adjustment for gestational age and maternal weight at 30-32 gestational weeks, the significant inverse relationship between maternal blood Cd and infant height was shown using the multiple regression analysis. Newborn size might be influenced by maternal blood Cd levels to which infants may be exposed during gestation.

Adult↗
PubMed2004

[Molecular mechanism of morphine tolerance and biological approaches to resolve tolerance].

One of the major problems associated with the chronic use of morphine is tolerance. Repeated uses of morphine to relieve pain often cause patients to develop increasing resistance to the effects of the drugs, so that progressively higher doses are required to achieve the same analgesic effects. Acquired tolerance is thought to be different from dependence or addiction, but molecular mechanism underlying the development of tolerance is still unclear. Tolerance has been explained by desensitization of opioid receptor signaling and loss of functional receptors in the cell surface. The classical hypothesis was that phosphorylation and arrestin binding resulted in uncoupling of the receptor from G proteins, and reduced agonist efficacy. The receptor internalization would then result in fewer functional receptors at the cell surface. These events would cause so-called signaling desensitization. However, recent molecular biological studies have led researchers to revise the classical view of tolerance from observations that morphine does not always promote efficient receptor internalization. Among several key processes, the sequestration and subsequent internalization of the opioid receptor may play an important role for morphine tolerance. In fact, recent studies have suggested that receptor internalization can reduce tolerance. In addition, activation of the NMDA subtype of the glutamate receptor has been suggested as an anti-opioid system in the development of morphine tolerance. In this review, we focus on recent research progress on the morphine tolerance, and molecular biological and clinical approaches to resolve morphine tolerance.

Animals↗
PubMed2004

Cisplatin enhances the p53-independent apoptosis induced by a topoisomerase I inhibitor (CPT-11) in the lens epithelial tumors in transgenic mice.

We reported that CPT-11 could induce apoptosis in mouse lens epithelial tumors when it was administered to pregnant alphaT3 mice which developed epithelial cell carcinoma in situ in the lens in the perinatal period. p53-deficient alphaT3 mice were generated to analyze the influence of p53 status on tumor cells under combined chemotherapy. On the 16-18th gestational day, alphaT3 received a single i.p. administration of both CPT-11 and Cisplatin, and fetal lens epithelial tumors were examined two days later. Apoptosis in the p53-wild-type alphaT3 tumors was observed in a Cisplatin dose-dependent manner. In addition, it was found that Cisplatin augmented CPT-11-induced p53-independent apoptosis in p53-deficient alphaT3 mice.

Animals↗
PubMed2004

[Postoperative laryngeal edema presumably due to hypoalbuminemia causing acute airway obstruction after extubation in a patient after nephrectomy].

We report here a case of upper airway obstruction occurring after extubation in a 55-yr-old 60 kg man after elective nephrectomy. Anesthesia was maintained with O2 (33%), N2O, sevoflurane (1.5-2%), and propofol infusion (2 mg x kg(-1) x hr(-1)). Blood loss was 1,965 ml, part of which was substituted by blood transfusion and albumin infusion. After surgery, the patient recovered uneventfully and could be extubated shortly. Twenty minutes after extubation, he developed dyspnea progressively with stridor and became cyanotic despite the use of oxygen mask and assisted ventilation. Oxygen saturation decreased gradually, and bradycardia (<30 beats x min(-1)) and severe hypotension were also observed. Cardiopulmonary resuscitation using epinephrine was immediately started. Re-intubation of the trachea was difficult due to severe edema, but eventually performed using a tube of a smaller size (internal diameter 7.0 mm). Subsequent investigations using a fiberscope confirmed extensive soft tissue swelling, maximal at the level of the vocal cord and extending up- and down-wards to the trachea, indicating that the obstruction is caused by severe laryngeal edema. We believe that edema may have been caused by hypoalbuminemia (1.3 g x dl(-1)) at the end of operation. Therefore, it should be noted that hypoalbuminemia may cause laryngeal edema leading to acute airway obstruction.

Acute Disease↗
PubMed2004

[Ventricular tachycardia induced by the change of position for epidural catheter insertion in a patient with hypertrophic obstructive cardiomyopathy].

We report here a case of ventricular tachycardia (VT) induced by the change of position for insertion of an epidural catheter before the induction of general anesthesia. A 79-yr-old woman was scheduled for elective right lung surgery. Past history included hypertension and hypertrophic obstructive cardiomyopathy (HOCM), which were treated with a calcium channel blocker and an anti-arrhythmic drug. Preoperative echocardiogram (ECG) showed first degree arterio-ventricular block and left ventricular hypertrophy. Before the induction of general anesthesia, the patient was turned into the left lateral position for the insertion of an epidural catheter. Shortly after the change of position, ECG showed transient VT, which lasted for approximately 40 sec, and she was forced to be turned to the supine position and required recovery for a time. VT was successfully treated and terminated by changing to the supine position and intravenous injection of 2% lidocaine (2 ml). The left radial artery was cannulated for monitoring arterial blood pressure and sampling. Since no abnormality was observed in ECG for the next twenty minutes, the patient was turned to the left lateral position again and epidural catheterization was performed through T 7-8 interspace. Considering some risk factors such as intraoperative change of position, the surgery was cancelled on that day. Postoperatively amiodarone was used and an implantable cardioverter defibrillator (ICD) was planted for risk reduction of sudden cardiac death due to ventricular arrhythmia. The cause of VT in our case is not certain; we believe that VT might be closely related to the left lateral position, especially keeping of the forward-bending position, which might cause compression to the heart and produce stenosis of the left ventricular outflow tract. It should be noted that severe tachyarrhythmia might occur after turning patients with HOCM.

Aged↗
PubMed2004

[Comparison of the effects of colloid and crystalloid solution for volume preloading on maternal hemodynamics and neonatal outcome in spinal anesthesia for cesarean section].

BACKGROUND: The role of crystalloid or colloid preloading to prevent hypotension associated with spinal anesthesia in parturients during cesarean section has recently been questioned. The aim of the current study was to investigate the effects of volume preload with either crystalloid or colloid, or with no preload on changes of maternal hemodynamics and neonatal outcomes. METHODS: After written informed consent had been obtained from each patient, thirty-two healthy parturients undergoing cesarean section were randomized to receive either acetated Ringer's solution (1,000 ml, n=8, AR group), 6% hydroxyethylstarch (1,000 ml, n=9, HES group), or no preload (n=10) before spinal anesthesia. In addition, emergency cases (n=5) such as prolonged labor without any maternal complication were also included for analysis. The incidence of hypotension, systolic blood pressure <80% of baseline or <100 mmHg, and the amount of ephedrine used to treat hypotension were compared. Neonatal outcome was also assessed measuring pH and lactate concentration in umbilical arterial blood samples. Apgar score was also measured at 1 and 5 min after delivery. RESULTS: There was no difference in demographic characteristics among the four groups. Minimal systolic arterial pressure (SAP) after spinal anesthesia did not differ among AR, HES, and no preload groups. However, a significant decline in SAP was observed in emergency group (82.2 +/- 14.3 mmHg, P<0.05). Although there was no difference in umbilical arterial blood pH, lactate concentration was significantly higher in emergency group (3.7 +/- 1.0 mmol x l(-1), P<0.01) than those of other groups. Apgar score at 1 min after delivery was significantly lower in emergency group. CONCLUSION: In healthy patients with full-term pregnancy, volume preloading has little effect on maternal hemodynamics and neonatal outcomes, suggesting that stable perioperative management is possible with or without volume preload before spinal anesthesia. However, preloading may be needed for prevention of hypotension in emergency cases.

Adult↗