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Biomedical subjects

R Shimizu

Publications and source records attributed to R Shimizu.

At least 199 records · Page 11Linked to original sources
PubMed1993

Plasma histamine levels during induction of anesthesia with propofol in dogs.

We examined a property of emulsion formation of propofol (ICI 35868) to release histamine into circulating plasma in dogs. Plasma histamine was measured with radioimmunoassay before (baseline), and 1, 5 and 10 min after the administration of 15 mg.kg(-1) propofol. There were no significant differences between the plasma histamine levels at 1, 5 and 10 min after the administration of propofol and the baseline level. We conclude that the emulsion formation of propofol of 15 mg.kg(-1) does not release histamine during induction of anesthesia in dogs.

Journal Article↗
PubMed1993

Effect of age on extradural dose requirement in thoracic extradural anaesthesia.

We have investigated the effect of age on thoracic extradural dose requirements in 62 patients aged 20-79 yr. Fifteen millilitre of 2% mepivacaine was administered at a constant rate (1 ml s-1) by syringe pump through an extradural needle at the T9-10 interspace. A mean of 15.5 (SD 4.2) spinal segments were blocked 15 min after completion of the administration. The extradural dose requirement decreased with increasing age (r = -0.7, P < 0.001), the requirement in the elderly (60-79 yr) being about 40% smaller than that in young adults (20-39 yr).

Adult↗
PubMed1993

Partial improvement of Olmsted syndrome with etretinate.

An 11-year-old Japanese boy with Olmsted syndrome was seen at our clinic. He had a sharply marginated, painful keratoderma with a red border on his palms and soles. Flexion contractures of the fingers were also observed. Hyperkeratotic plaques were present below the lower lip, on the elbows and knees, and in the sacral area. Localized alopecia, leukokeratosis on the tongue, shortness of stature, and laxity of the large joints corresponded to the clinical features of Olmsted syndrome. Treatment with etretinate was effective for the palms and fingers, but resulted in no improvement of the keratoderma of the soles. Because of periosteal thickening of the tibia, presumably caused by etretinate, therapy was terminated one year after it began.

Child↗
PubMed1993

Selective beta 1-adrenoceptor agonist activity of denopamine and its derivatives in dogs.

Cardiovascular effects of intravenously administered denopamine and its derivatives were investigated in anesthetized dogs and their positive inotropic and hypotensive effects were compared. Structure-activity relationships were examined by modifying the methoxy group in ring B and the hydroxy group in ring A in structure II, a ring-fissioned product of trimetoquinol. Almost all test compounds demonstrated positive inotropic and chronotropic effects as well as hypotensive effects which were mediated by beta-adrenoceptors. With modification of the methoxy group in ring B, only 3,4-dimethoxy, 2,3,4-trimethoxy and 3,4,5-trimethoxy derivatives exhibited beta 1-adrenoceptor selectivity. The 3,4-dimethoxy derivative showed the most potent positive inotropic effect and the highest selectivity to beta 1-adrenoceptor. By structural modification of the hydroxyl group in ring A of the 3,4-dimethoxy derivatives, the potency of positive inotropic effect was affected, while beta 1-adrenoceptor selectivity of the derivatives with 3,5-dihydroxy, 3- and 4-monohydroxy groups were essentially maintained. Among beta 1-adrenoceptor selective compounds, the dose ratios between intravenous and intraduodenal administrations of catechol derivatives like isoproterenol were higher than those of non-catechol derivatives. The 4-monohydroxy derivative (racemic denopamine) exhibited the smallest dose ratio with a long-lasting action. Thus, we could identify selective beta 1-adrenoceptor agonists by the structural modification of a selective beta 2-adrenoceptor agonist, trimetoquinol. In this group of compounds, beta-hydroxy moiety was suggested to be requisite to potent beta-adrenoceptor stimulating action and 3,4-dimethoxyphenethyl structure was important for manifestation of beta 1-adrenoceptor selectivity.

Adrenergic beta-Agonists↗
PubMed1993

Evaluation of phlebotomy-induced erythropoietin production in the dog.

Erythropoietin (EPO) production in dogs was studied by reducing red blood cells with phlebotomy. In this study, the hemoglobin reduction rate (delta %Hb) was newly taken into account as the regulating factor for EPO production, and its usefulness to estimate the stimulating intensity to EPO production was examined. As the result, plasma EPO was highly correlated with delta %Hb showing the importance related to regulation of EPO production, in the increasing plasma EPO by different degrees of phlebotomy, in the change of plasma EPO through the anemia progress and recovery period after severe phlebotomy, and in the initial variation of plasma EPO induced by chronic mild phlebotomy. On the other hand, increasing EPO production appeared at least within 6 hr after acute severe phlebotomy, which revealed significantly higher plasma level compared with the mild chronic phlebotomy, suggesting the effect of time leading to red blood cell reduction on EPO production response. Simultaneously, considering an in vivo EPO half life of 8.4 hr calculated from plasma EPO disappearance after bilateral nephrectomy, endogenous plasma EPO accumulation should be taken into consideration in rapidly increasing of delta %Hb.

Anemia↗
PubMed1993

Evaluation of erythropoietin production in dogs with reduced functional renal tissue.

This study was designed to determine the quantity of functional renal tissue needed to maintain homeostasis of red blood cell production by evaluating the erythropoietin (EPO) production response to phlebotomic stimulation in the 1/2- and 1/4-kidney dogs surgically prepared. The results showed that the reduction in functional renal tissue caused a decrease in EPO production, which led to the delay in recovery from anemia. In the anemic progress stage, the plasma EPO level showed a transition proportional to the quantity of functional renal tissue immediately after the operation for tissue reduction. The 1/2-kidney dog group still kept such proportional relation even in the recovery stage. Thus, the half of the normal renal tissue was considered sufficiently contributory to EPO production needed to maintain homeostasis of red blood cell production. However, the 1/4-kidney dog group precipitously decreased in plasma EPO level in the recovery stage and fell into an extremely unfavorable anemia. This indicated that homeostatic maintenance in erythropoiesis would be impossible more below a quarter of normal renal tissue. These findings disclosed that reduction in functional renal tissue quantity would sensitively influence homeostatic maintenance of red blood cell production through the decrease in EPO production, even if it does not affect renal function concerned with urine production.

Anemia↗
PubMed1993

Left ventricular wall thickness in normal mongrel dogs.

To clarify the normal value of ventricular wall thickness we directly measured the ventricular wall thickness of 50 normal mongrel dogs of one year old. Because of a wide range in body weight from 6.0 to 16.0 kg of these 50 dogs, we selected 34 dogs weighing 8 to 12 kg to calculate the mean ventricular wall thickness as normal value of one year old. The results obtained were as follows; (1) The mean and standard deviation of the left ventricular wall thickness was 7.1 +/- 1.2 mm at anterior, 6.3 +/- 1.6 mm at posterior, 7.1 +/- 1.3 mm at lateral, 10.3 +/- 1.8 mm at the interventricular septum, and that of the right ventricular wall thickness was 3.4 +/- 1.0 mm. (2) Although any site of the ventricular wall thickness correlated significantly to heart weight, only the anterior left ventricular wall and interventricular septum barely correlated to body weight. (3) There was no significant correlation between arterial blood pressure and the ventricular wall thickness. Further study should be necessary to clarify influences of aging on the ventricular thickness and to determine the criteria of ventricular hypertrophy.

Alanine Transaminase↗
PubMed1993

Assessment of pulmonary edema based on extravascular thermal volume in dogs.

To establish criteria of pulmonary edema by extravascular thermal volume (ETV), ETV and a roentgenogram of the thorax were compared in normal and experimental hydrostatic pulmonary edema dogs. ETV was measured by the double indicator dilution technique using heat as a diffusible indicator and sodium ions as a non-diffusible indicator (thermal-Na method). Mean ETV in 14 dogs under physiologic conditions was 8.20 +/- 1.44 ml/kg. Comparison of ETV with the roentgenogram indicated the density of thoracic the roentgenogram to increase when ETV exceeded 11 ml/kg. Pulmonary edema was recognized clearly in the thoracic roentgenogram at more than 15 ml/kg of ETV. Further increase in ETV did not occur with additional radiographic change. ETV was significantly (P < 0.01) correlated with arterial oxygen tension (PaO2) but not statistically correlated with colloid oncotic pressure (COP), pulmonary arterial wedge pressure (PAWP) or PAWP-COP. Measurement of ETV would thus, appear to be a reliable method for evaluating the severity of pulmonary edema, which has been difficult to diagnose by roentgenography and should facilitate the early diagnosis and management of pulmonary edema.

Animals↗
PubMed1993

[The spread of spinal anesthesia in young patients].

We have studied the spread of spinal anesthesia with Neo-percamine S, containing hyperbaric dibucaine, in 20 younger patients (13-18 yr) and 20 older patients (22-61 yr). In younger patients, 2.17 +/- 1.7 (mean +/- SD) ml of the anesthetic solution blocked 19.4 +/- 1.7 spinal segments. In older patients, 2.22 +/- 0.18 ml of the solution blocked 16.3 +/- 0.18 spinal segments. Spinal anesthesia higher than T3 level was observed in 45% of the younger patients, whereas such level of spinal anesthesia was not observed in the older patients. Our results suggest that hyperbaric dibucaine solution for spinal anesthesia may have a tendency to produce an unexpectedly extensive spread of anesthesia in young patients.

Adolescent↗
PubMed1993

[Comparison of the severity of postoperative pain in patients after thoracic, upper abdominal or lower abdominal surgery].

Different factors influence the severity of postoperative pain. Personality and cultural factors as well as anxiety and fear modify the degree of postoperative pain. The site of surgery is also a major determinant. We evaluated the severity of postoperative pain in patients after three different surgeries, thoracic, upper abdominal and lower abdominal surgeries, from 24 h to 72 h postoperatively. Thirty patients were divided into three groups: thoracic, upper abdominal and lower abdominal groups (n = 10, respectively). All patients received continuous epidural infusion of 0.25% bupivacaine (2 ml.h-1) and buprenorphine (0.2 mg x 24 h-1). Additional analgesics were given when the patient complained of pain. Analgesia was evaluated by 100 mm visual analog scale and demands of analgesics. Pain scores at rest were not different among three groups. Pain after lower abdominal surgery tended to be less severe compared with that after thoracic surgery. Demands of analgesics were not different among three groups at any evaluated point. Pain after thoracic surgery was consistent during 72 postoperative hs, but in the upper and lower abdominal surgery groups pain at 72 hs was significantly weaker than that at 24 hs. We conclude that postoperative pain was not different among the three surgery groups, but pain after upper and lower abdominal surgery decreased more rapidly compared with that after thoracic surgery.

Abdomen↗
PubMed1993

[Continuous epidural buprenorphine for postoperative pain relief in patients after lower abdominal surgery].

Postoperative analgesia with epidurally injected buprenorphine and its side effects were investigated in 100 patients who had received lower abdominal surgery. All patients received initially 8 ml of bupivacaine and 0.1 mg of buprenorphine. Following bolus epidural injection, five different groups of 20 patients each received either bupivacaine alone (group A), 5 micrograms.ml-1 buprenorphine.bupivacaine mixture (group B), 8 micrograms.ml-1 buprenorphine.bupivacaine mixture (group C), 12 micrograms.ml-1 buprenorphine.bupivacaine mixture (group D), or 15 micrograms.ml-1 buprenorphine.bupivacaine mixture (group E) by a portable disposable device at a rate of 1 ml.h-1 for 48 h. The analgesic efficacy in group E was superior to those in groups A, B, C or D. No significant difference in the incidence of side-effect was found among groups C, D, E. We conclude that a dose of a approximately 15 micrograms.h-1 might be optimal for postoperative pain relief after lower abdominal surgery.

Abdomen↗
PubMed1993

[Patient-controlled analgesia with epidural pethidine or buprenorphine plus bupivacaine for postoperative analgesia].

We evaluated the efficacy of epidural patient-controlled analgesia (PCA) with pethidine or buprenorphine plus 0.25% bupivacaine for postoperative analgesia after laparotomy with a midline incision under general anesthesia. Twenty patients were randomly allocated to two groups. In one group (PCEA-P group; n = 10), epidural pethidine plus 0.25% bupivacaine by PCA with 5 mg of pethidine and 2.5 ml of 0.25% bupivacaine bolus with a lockout interval of 20 min was added to a continuous epidural infusion of 0.25% bupivacaine (2 ml.h-1) plus pethidine (100 mg.24h-1) for 72 h. In the other group (PCEA-B group; n = 10), epidural buprenorphine plus 0.25% bupivacaine by PCA with 0.03 mg of buprenorphine and 2.5 ml of 0.25% bupivacaine bolus with a lockout interval of 20 min was added to a continuous epidural infusion of 0.25% bupivacaine (2 ml.h-1) and buprenorphine (0.6 mg.24 h-1) for 72 h. Analgesia was evaluated by 100 mm visual analog scale and verbal descriptor scale. In PCEA-B group, 90% of the patients did not complain of pain at rest, and in PCEA-P group, all the patients did not complain of pain at rest for 72 h. There were no significantly different analgesic effects between PCEA-P and PCEA-B for 48 h. The average doses of epidural PCA were 1.9 mg.kg-1.24 h-1 of pethidine, and 0.012 mg.kg-1.24 h-1 of buprenorphine, respectively. We conclude that PCEA-P and PCEA-B were effective for postoperative pain to the same degree for the first 48 h, but PCEA-P was superior to PCEA-B for the last 24 h.

Abdomen↗
PubMed1993

[Spread of spinal anesthesia with 0.5% isobaric bupivacaine].

The effects of age, weight, height, weight.height ratio, and body mass index on the spread of spinal anesthesia with 3.0 ml of 0.5% isobaric bupivacaine was examined in 185 patients. No significant correlation was found between the spread of analgesia and the age, weight, height, weight.height ratio, or body mass index. A significant correlation was found between the decrease in mean arterial pressure and the height of sensory analgesia (rho = -0.21, P < 0.05) as well as the aging (rho = -0.35, P < 0.001).

Adolescent↗
PubMed1993

[Rapid induction of anesthesia with inhalation of sevoflurane].

Induction of anesthesia with inhalation of sevoflurane was evaluated in 45 patients. Inhalation anesthesia was induced by a single vital capacity breath followed by spontaneous breathing. The compositions of anesthetic gases were as follows: 5% sevoflurane in oxygen, 5% sevoflurane in 67% nitrous oxide and oxygen, and 7% sevoflurane in 67% nitrous oxide and oxygen. The time (mean +/- SEM) necessary for the loss of consciousness was 85 +/- 6, 56 +/- 4, and 42 +/- 3 seconds, and breathing frequency was 8 +/- 1, 5 +/- 0.6, 1.4 +/- 0.2, in each composition of anesthetic gasses, respectively. Changes in blood pressure and heart rate were relatively small. The technique was found to be acceptable to all of the patients studied. We conclude that the technique of single breath induction with sevoflurane is a safe and acceptable alternative to intravenous induction in cooperative adult patients.

Adult↗
PubMed1993

[Postoperative pain therapy: a survey of patient attitudes to postoperative pain relief].

We surveyed the attitudes of general surgical patients to the management of their postoperative pain relief. Elective surgical patients (n = 232) were asked postoperatively about their experienced pain which was expressed according to verbal pain scale, the duration of experienced pain, satisfaction with pain relief and medication, and expectations of pain on the 5th to 7th postoperative day. Thirteen percent of the patients had no pain, 47% of whom had no rest pain but pain on moving or coughing, 32% of whom had rest and moving pain, and 0.4% of whom experienced horrible and excruciating pain. Duration of postoperative pain was 2.5 +/- 1.9 days, and 76% of the patients experienced pain only for 3 postoperative days. Results of the interviews indicated that 80% of these patients were satisfied with their postoperative pain relief. Although 80% expressed satisfaction, 39% of whom did have rest pain. In the patients with continuous epidural infusion of buprenorphine and 0.25% bupivacaine, incidence of complained rest pain was significantly low compared with those with intermittent i.v. and/or im injection of analgesics on demands of patients. Lag between patient's demand and nurse's response concerning medication correlated significantly to the satisfaction. There was no relation between satisfaction and age, the nature of operation or sex. Fifty-two percent of the patients reported that degree of experienced pain had been less than expected preoperatively. In conclusion, 80% of the patients were satisfied, but our postoperative pain therapy was still insufficient because 39% of them had rest pain.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[Serum nitroglycerin concentrations during extracorporeal circulation with a membrane oxygenator incorporated with a cardiopulmonary bypass circuit].

The effect of a cardiopulmonary bypass circuit (CPB) on serum nitroglycerin (TNG) concentrations was studied in eight patients scheduled for cardiac surgery. The CPB consisted of polyvinyl chloride tubes and polypropyrene membrane oxygenator. TNG was administered intravenously at a rate of 1 microgram.kg-1.min-1 after induction of anesthesia. Blood samples were obtained from the radial artery, central vein, venous inlet of the CPB, and arterial outlet of the CPB. No significant difference in serum TNG concentration was found between the venous inlet of the CPB and arterial outlet of the CPB. Serum TNG concentration tended to increase during complete extracorporeal circulation. This suggests that the hypothermic inhibition of TNG metabolism may be greater than the adsorption of TNG by the CPB.

Adolescent↗
PubMed1993

[Effect of age on dose requirement for lumbar epidural anesthesia].

In 161 patients, aged 19-75 yr and subjected to epidural anesthesia for extracorporeal shock wave lithotripsy, the relationships between the spread of lumbar epidural analgesia with 10 ml of 2% mepivacaine and age, height, weight, weight/height ratio, and body mass index were studied. The highest correlation was found between the age and the spread (r = 0.67, P < 0.001). The next higher correlation was found between the height and the spread (r = -0.32, P < 0.001). The lowest but a statistically significant correlation was found between the body mass index and the spread (r = 0.16, P < 0.05). A strong inverse linear relationship was found between the age and the epidural dose requirement (r = -0.59, P < 0.001).

Adult↗