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Biomedical subjects

R Shimizu

Publications and source records attributed to R Shimizu.

At least 19 recordsLinked to original sources
PubMed1996

Role of c-jun in the inhibition of erythropoietin receptor-mediated apoptosis.

Human bone marrow cells express both a truncated and full-length form of the erythropoietin receptor (EpoR-T and EpoR-F, respectively). Transfection experiments using the murine interleukin (IL)-3-dependent cell line, Ba/F3, revealed that the cells coexpressing EpoR-F and EpoR-T (Ba/F3-FT) were more likely to undergo programmed cell death (apoptosis) than cells expressing EpoR-F (Ba/F3-FF), even in the presence of erythropoietin (Epo). When Ba/F3-FF cells were stimulated with Epo or IL-3, rapid induction of c-myc, c-fos, c-jun and junB genes was observed. A similar effect was also seen in IL-3 stimulated Ba/F3-Ft cells. However, in Ba/F3-FT cells expression of the c-jun gene was not induced by Epo stimulation. Administration of Epo could prevent apoptosis induced by IL-3 deprivation in Ba/F3-FT cells expressing ectopic c-Jun protein. These results indicate that induction of c-Jun through the Epo signaling pathway has an important role in the inhibition of apoptosis.

Animals↗
PubMed1996

Anatomical configuration of the spinal column in the supine position. III. Comparison of adolescent and adult volunteers.

To clarify the anatomical configuration of the spinal column in the adolescent in the supine position, we have studied 10 adolescent (13-17 yr) and 10 adult (26-38 yr) volunteers using magnetic resonance imaging. T1-weighted sagittal midline magnetic resonance images of the spinal column were obtained with subjects in the supine position. The maximum angles of decline of the lumbar spinal canal did not differ between the adolescent (mean 13.6 (SD 3.3) degrees) and adult (12.4 (3.8) degrees) groups. The maximum angles of incline of the upper thoracic spinal canal were smaller in the adolescent group (15.9 (4.7) degrees) than in the adult group (26.4 (5.8) degrees). The median highest point of the lumbar spinal canal was located at L4 (range L3-4 to L4-5) in both groups. The lowest points of the thoracic spinal canal in the adolescent and adult groups were located at T8-9 (T7 to T9) and T8 (T6-7 to T9), respectively. This study showed that thoracic kyphotic curvature in adolescents was reduced significantly in the supine position compared with that in adults. This minimized thoracic kyphosis may explain, in part, the enhanced cephalad spread of subarachnoid hyperbaric anaesthetic solutions in adolescents.

Adolescent↗
PubMed1996

Airway management for patients with a tracheal bronchus.

A tracheal bronchus is an aberrant, accessory or ectopic bronchus arising almost invariably from the right lateral wall of the trachea, causing hypoxaemia, atelectasis, or both, during anaesthesia. We describe two patients with a tracheal bronchus found before anaesthesia. One tracheal bronchus was found by tracheobronchoscopy and the other by chest x-ray. Because of recognition of the anomaly before operation, anaesthesia was uneventful in each patient.

Anesthesia, General↗
PubMed1996

The effects of sevoflurane and isoflurane anesthesia on renal tubular function in patients with moderately impaired renal function.

Increasing evidence indicates that sevoflurane anesthesia does not impair renal function in healthy patients despite higher concentrations of plasma inorganic fluoride. However, whether sevoflurane further affects renal tubular function in patients with impaired renal function is not known. We compared the effect of sevoflurane anesthesia with that of isoflurane anesthesia on renal tubular function in patients with moderately impaired renal function. Fourteen patients with creatinine clearance between 10 and 55 mL/min were anesthetized with either sevoflurane or isoflurane using a semiclosed circuit system. Plasma inorganic fluoride concentrations and urine N-acetyl-beta-D-glucosaminidase (NAG), gamma-glutamyltranspeptidase (gamma-GTP), and beta 2-microglobulin (beta 2MG) excretions were measured up to post-anesthetic day 14. Although both the peak plasma inorganic fluoride concentrations and the areas under the curve of plasma inorganic fluoride concentration versus time were significantly greater in the sevoflurane group than in the isoflurane group, urine NAG, gamma-GTP, and beta 2MG excretions per day did not differ between the two groups. These results indicate that sevoflurane and isoflurane may have similar effects on the renal tubules in patients with moderately impaired renal function.

Acetylglucosaminidase↗
PubMed1995

[Psychological evaluation of out-patients in our pain clinic using self-rating depression scale and state-trate anxiety inventory questionnaire].

In 98 out-patients who visited our pain clinic, we evaluated their psychological status before the first examination and one month after the treatment, using self-rating depression scale (SDS) and state-trate anxiety inventory (STAI). SDS, state anxiety, and trate anxiety scores were significantly higher in the patients with pain (trigeminal neuralgia, neck-shoulder-arm pain syndrome, lumbago and psychological pain, n = 55) compared with the patients without pain (sudden deafness and facial nerve palsy, n = 43) (P < 0.01, 0.05, 0.01). Of the patients with pain, patients with psychogenic pain showed the highest score in every test. The scores of SDS and state anxiety became significantly lower one month after the treatments compared with ones before the first examination (P < 0.01). It was considered that the decline in every score was due to the treatments in our pain clinic. In patients whose score of trate anxiety before the first examination was more than 50 points, the SDS and state anxiety showed high scores even one month after the treatments. This finding suggests that these patients need psychosomatic managements.

Adult↗
PubMed1995

[Reevaluation of hypothermia as protective measures against cerebral ischemia].

Two patients underwent carotid artery ligation for the purpose of surgical hemostasis either under hypothermia or under normothermia. One was 56-year-old man with rupture of brachiocephalic artery following esophagectomy. The bilateral common carotid arteries were ligated for bypass-grafting between the right internal carotid artery and the left common carotid artery for 35 min under surface-induced hypothermia at a rectal temperature of 30.7 degrees C. No postoperative neurological deficit developed. The other was 40-year-old woman with a malignant parotid tumor involving left internal carotid artery. The left carotid artery was ligated for 20 min at a rectal temperature of 37.3 degrees C. Cerebral ischemia developed postoperatively. Mild to moderate hypothermia should be reevaluated as one of useful measures to protect the brain from cerebral ischemia.

Adult↗
PubMed1995

Role of nitric oxide in anaphylactic shock.

Nitric oxide, synthesized from the guanidino group of L-arginine by nitric oxide synthase, has an important role in pathophysiological changes associated with anaphylaxis. Nitric oxide production due to activation of constitutive nitric oxide synthase is detected using a nitric oxide-selective electrode in anaphylactic rabbits in vivo. A nitric oxide synthase inhibitor attenuates hypotension and hemoconcentration and decreases venous return but does not improve cardiac depression. Nitric oxide functionally antagonizes the effects of vasoconstrictors released by anaphylaxis in vitro. In animals pretreated with a nitric oxide synthase inhibitor, the cardiac output falls significantly, although venous return is increased. Pulmonary resistance is significantly increased with a nitric oxide synthase inhibitor, and L-arginine attenuates the bronchospasm. These findings suggest that production of nitric oxide may reduce the pathophysiologic changes, except for vasodilatation, associated with anaphylaxis.

Anaphylaxis↗
PubMed1995

Combination chemotherapy of carboplatin and cytosine arabinoside for high-risk leukemia: a pilot study.

Fourteen patients with high-risk leukemia (six with relapsed AML, three with relapsed ALL, one with AML-M0, four with CML in myeloid blastic crisis) were treated with a combination chemotherapy of carboplatin (200-300 mg/m2/day) and cytosine arabinoside (100 mg/m2/day) by 24 h continuous infusion for 5-7 days. Five patients (35.7%) achieved complete remission including two patients complicated with myelofibrosis (one with AML-M0 and one with CML in myelo-megakaryocytic crisis). Thirteen patients had nausea and vomiting, five patients had severe, prolonged neutropenia for which it was necessary to administer granulocyte colony-stimulating factor and six patients had severe thrombocytopenia. We concluded that this regimen is effective for the treatment of high-risk leukemia.

Adolescent↗
PubMed1995

Suppressive effects of volatile anesthetics on cytokine release in human peripheral blood mononuclear cells.

This study investigated the effects of three volatile anesthetics (sevoflurane, isoflurane, and enflurane) on cytokine release by human peripheral mononuclear cells (PBMCs) stimulated by natural killer (NK)-sensitive tumor cells, K562, in vitro. PBMCs, as effector cells, obtained from 31 volunteers were randomly allocated to two groups in the first set of experiments. One group was incubated with K562 (n = 21) and the other with medium alone as a control (n = 10). In a second set of experiments, PBMCs from each volunteer (n = 21) were divided into three groups: nonanesthetic, 1.5-MAC, and 2.5-MAC groups (n = 7 for each anesthetic). After 2 h exposure to anesthetic gas or air, K562 cells were added to the effector cells. After 4 h incubation, interleukin-1 beta (IL-1 beta), interleukin-2 (IL-2), tumor necrosis factor-alpha (TNF-alpha), and interferon-alpha (INF-alpha) in the supernatant were assayed. IL-1 beta and TNF-alpha levels were significantly increased in comparison with those in the control group. IL-2 levels tended to be higher than those in the control group. No effect on IFN-alpha levels was found. After anesthetic exposure, the releases of IL-1 beta and the release of TNF-alpha were significantly inhibited compared with those after air exposure. None of the anesthetics inhibited IL-2 release. The anesthetics studied are capable of altering the release of cytokines by NK and NK-like cells in response to tumor cells.

Anesthetics, Inhalation↗
PubMed1995

Infrared angiography of the anterior ocular segment.

We performed angiography with indocyanine green (ICG) and fluorescein using a scanning laser ophthalmoscope (SLO) in the anterior segments of seven normal and 35 diseased eyes. ICG angiography revealed the radical stromal vessels and minor arterial circle in brown irides, which were not detected by fluorescein angiography. High penetration of infrared fluorescence through the pigmented tissue and absence of extravasation of ICG facilitated demonstration of the fine structure of iris rubeosis and its origins from stromal vessels. In 11 diabetic eyes, the iris rubeosis showed three basic patterns of location: along the pupillary margin; originating from the iris root; and arising from stromal radial vessels near the collarette. ICG gonioangiography with SLO showed fine structure of angle rubeosis because of its high resolution and greater depth in focus. Rubeotic vessels in the chamber angle were perfused by neovascular trunks which arose from the iris root in all 12 rubeotic eyes. Rubeosis in the iris and the angle consistently showed no extravasation of the ICG dye, while fluorescein quickly leaked out. ICG angiography with SLO in the anterior ocular segment proved to be a useful means to study the structure and the hemodynamics of normal and newly formed vessels.

Adult↗
PubMed1995

Spread of subarachnoid hyperbaric amethocaine in adolescents.

We have compared the spread of subarachnoid hyperbaric amethocaine in adolescents with that in adults. Amethocaine 8 mg in 2 ml of 10% glucose was injected through a 25-gauge spinal needle inserted at the L3-4 interspace in 21 adolescents aged 12-16 yr and in 111 adults aged 17-82 yr. Although we found no differences in height, weight or body mass index between the adolescents and adults, maximum spread of analgesia was significantly higher in the adolescents (median T3 (range T4-C5) than in the adults (T4 (T9-C7)). We conclude that subarachnoid injection of hyperbaric amethocaine produces an unexpectedly higher level of analgesia in adolescents than in adults.

Adolescent↗
PubMed1995

Spread of subarachnoid hyperbaric amethocaine in pregnant women.

In order to examine how the gestational period influences the spread of spinal anaesthesia, we have measured the extent of spinal block produced by hyperbaric amethocaine 8 mg in 90 women. The patients were allocated to one of five groups according to the gestational period: non-pregnant group (n = 17), first trimester group (6-12 weeks, n = 14), second trimester group (13-24 weeks, n = 26), third trimester group (25-36 weeks, n = 15) and term group (37-41 weeks, n = 18). Maximum cephalad spread of analgesia was significantly higher in the second trimester (median T3 (range T9-C6)), third trimester (T3 (T4-C7)) and term groups (T2.5 (T4-C8)) than in the nonpregnant (T4 (T8-T2)) and first trimester groups (T4 (T11-C7)). We found that not only term pregnancy but also second and third trimester pregnancies enhanced the spread of spinal anaesthesia, and that first trimester pregnancy did not affect the spread of spinal anaesthesia.

Adult↗
PubMed1995

Anatomical configuration of the spinal column in the supine position. I. A study using magnetic resonance imaging.

In order to clarify the anatomical configuration of the spinal column in the supine position, we have examined T1-weighted sagittal midline magnetic resonance images of the spinal column in 20 healthy volunteers (11 men, nine women) in the supine position. The mean maximum angles of decline of the lumbar spinal canal in men and women were 12.6 (SD 3.9) degrees and 13.4 (3.3) degrees in the cephalad direction, respectively. The maximum angles of incline of the upper thoracic spinal canal in men and women were 20.3 (4.0) degrees and 18.5 (2.5) degrees, respectively. The median highest points of the lumbar spinal canal in men and women were located at L4 (range L3-4 to L4) and L4 (L4), respectively. The lowest point of the thoracic spinal canal was located at T8 (T7-T9) in both men and women. We have demonstrated that both lumbar lordosis and thoracic kyphosis differ between individuals, particularly with respect to the lowest point of the thoracic spinal canal, which is located between T7 and T9.

Adolescent↗
PubMed1995

Anatomical configuration of the spinal column in the supine position. II. Comparison of pregnant and non-pregnant women.

To assess the changes in the curvature of the spinal column in the supine position during pregnancy, we studied seven pregnant (32-37 weeks of pregnancy) and seven non-pregnant women using magnetic resonance imaging. T1-weighted sagittal midline magnetic resonance images of the spinal column were obtained with subjects in the supine position with left tilt. There was no significant difference in the maximum angle of decline of the lumbar spinal canal between the pregnant (mean 12.4 (SD 3.3) degrees) and non-pregnant (13.4 (3.9) degrees) groups. The maximum angle of incline of the upper thoracic spinal canal was smaller in the pregnant (15.8 (2.9) degrees) than in the non-pregnant (22.7 (6.0) degrees) group. The highest point of the lumbar spinal canal was located at a lower lumbar region in the pregnant (median L4-5 (range L4 to L4-5)) than in the non-pregnant (L4 (L3-4 to L4)) group. The lowest point of the thoracic spinal canal was located at a higher thoracic region in the pregnant (T6-7 (T6 to T7-8)) than in the non-pregnant (T8 (T6-7 to T9)) group. This study revealed that the apex of lumbar lordosis was caudad and thoracic kyphosis was reduced in the supine position in the later stages of pregnancy. These changes in the curvature of the spinal column may explain, in part, the enhanced cephalad spread of subarachnoid hyperbaric anaesthetic solutions in the later stages of pregnancy.

Adult↗
PubMed1995

Visceral pain during caesarean section: effect of varying dose of spinal amethocaine.

The aim of this study was to determine how varying the dose of spinal amethocaine influences the incidence of visceral pain associated with exteriorization of the uterus after delivery. In a double-blind study, we examined the incidence of visceral pain in 40 parturients undergoing Caesarean section under spinal anaesthesia with amethocaine 8, 10, 12 or 14 mg in 2 ml of 5% glucose. The dose of spinal amethocaine was found to influence the incidence of visceral pain associated with exteriorization of the uterus after delivery. The incidence of visceral pain was lower in the 12-mg (P < 0.05) and 14-mg (P < 0.01) groups than in the 8-mg group, although there were no differences in maximum spread of analgesia and circulatory changes between the four groups. This study suggests that a slightly higher dose of spinal amethocaine (12-14 mg) is preferable for Caesarean section.

Adult↗
PubMed1995

Effects of graded infusion rates of propofol on cardiovascular haemodynamics, coronary circulation and myocardial metabolism in dogs.

We have studied the effects of a 30-min infusion of propofol 6, 9, 12, 15, 18 and 21 mg kg-1 h-1 on cardiovascular haemodynamics, coronary circulation and myocardial metabolism in 12 mongrel dogs. Mean plasma concentrations of propofol after infusion of 6 and 21 mg kg-1 h-1 increased from 2.9 (SEM 0.3) to 11.5 (0.1) micrograms ml-1. Propofol produced a progressive decrease in arterial pressure. Heart rate tended to decrease at 15, 18 and 21 mg kg-1 h-1 and cardiac index decreased significantly at infusion rates > or = 9 mg kg-1 h-1. Systemic vascular resistance tended to increase except at 21 mg kg-1 h-1 and left ventricular systolic and diastolic function were depressed. Both coronary sinus blood flow and myocardial oxygen consumption decreased in parallel with a decrease in left ventricular minute work index without producing lactate. Propofol produced progressive decreases in coronary blood flow and myocardial oxygen consumption but did not exert adverse effects on the coronary circulation.

Anesthetics, Intravenous↗