Biomedical subjects

M Miyamoto

Publications and source records attributed to M Miyamoto.

At least 361 records · Page 20Linked to original sources

PubMed1991

[Anesthetic management of a patient with Chubby Puffer syndrome].

Chubby Puffer syndrome produces symptoms such as sleep apnea, cor pulmonale and upper airway obstruction due to adenotonsillar enlargement. We gave anesthesia for adenotonsillectomy in a 6-year-old boy with this syndrome. The child was massively obese. Anesthesia was induced with thiamylal, nitrous oxide and enflurane by monitoring SaO2. Tracheostomy was performed following orotracheal intubation because of possible difficult postoperative course. At the beginning of operation arterial blood studies showed hypoxemia. Positive end-expiratory pressure ventilation was effective to improve oxygenation. After adenotonsillectomy the symptoms were relieved.

Adenoidectomy↗

PubMed1991

[Histochemical changes of islet cells of Langerhans after hepatectomy and effect of glucagon and insulin].

It has been made by a number of studies that after hepatic resection, portal factors such as insulin and glucagon play an important role in liver regeneration. We have reported hypertrophy of Langerhans islands of dogs after partial hepatectomy. In the present study we attempted to clarify the mechanism of this hypertrophy. In a control group, a forty-percent hepatectomy was carried out. One and four weeks after surgery, 0.5g/kg of glucose was administered intravenously followed by a blood sampling from the portal vein to measure the changes of glucose, insulin and glucagon respectively. In addition area changes of the islets of Langerhans after the operation were measured with PAP technique. In a GI group, the same experiment as in the control group was done and 1mg of glucagon and 2IU/kg of insulin were administered every morning after the operation. The following results were obtained. In the GI group, there were no decrease in portal plasma insulin level and no enlargement of the sizes of the islets four weeks after surgery.

Animals↗

PubMed1991

[Centrifugal pump as right ventricular assist pump in the treatment of right ventricular failure following resection of left atrial myxoma].

A 31-year-old woman had a left atrial myxoma associated with severe pulmonary hypertension and respiratory failure because of incarceration of the tumor to the mitral valve. Emergency surgery was performed, but the patient could not be weaned from cardiopulmonary bypass because of right ventricular failure. A Biomedicus centrifugal pump was used as a right ventricular assist pump. The result was a successful termination of cardiopulmonary bypass. With the support of an intra-aortic balloon pump, the right ventricular assist pump was removed 38 hours after the operation, and the intra-aortic balloon pump was terminated 2 days later. The centrifugal pump is very useful at the majority of centers where the pneumatically activated bi-valved ventricular assist device is unavailable. The Biomedicus centrifugal pump can be easily applied for treatment of perioperative right ventricular failure and is very useful for short-term use without systemic anticoagulants.

Adult↗

PubMed1990

[A case of prolonged jaundice after surgical treatment of obstructive jaundice caused by a carcinoma of the head of the pancreas relieved with dibutyryl cyclic AMP].

Recently, we experienced a case of obstructive jaundice caused by a carcinoma of the head of the pancreas which could not be relieved by reduction surgery. The operation performed was a cholecystectomy and supraduodenal choledochotomy with T-tube insertion. Glucagon and insulin were, therefore, administered with the aim towards the recovery of the liver function to be induced by the enhancement of the liver regeneration. The treatment, however, was not effective. Then, dibutyryl cyclic AMP was administered to the case by intravenous drip infusions at the rate of 5 micrograms/kg/min. Thereafter, the value of serum total bilirubin was reduced remarkably. A prolonged and intense obstructive jaundice is generally accompanied by damage to the liver function, and the condition carries a high risk of postoperative complication. In this paper, the effectiveness of dibutyryl cyclic AMP on liver cell damage caused by prolonged obstructive jaundice are reported.

Aged↗

PubMed1990

Absence of the type I IFN system in EC cells: transcriptional activator (IRF-1) and repressor (IRF-2) genes are developmentally regulated.

Interferons (IFNs) are a heterogeneous family of cytokines that exhibits multiple biological activities. Upon viral infection, expression of type I IFNs (i.e., IFN-alpha and IFN-beta) is induced in a variety of differentiated cells but not in cells of embryonal origin. IRF-1 and IRF-2, which bind to the same cis-elements within the promoters of type I IFN and IFN-inducible MHC class I genes, were identified previously. Here we demonstrate that the expression of both IRF and IFN genes is developmentally regulated in mouse EC cells; these genes become functional only after cell differentiation. Furthermore, cDNA-directed IRF-1 produced in undifferentiated but not differentiated EC cells efficiently activates the transfected IFN-alpha and IFN-beta and endogenous IFN-alpha genes, whereas IRF-2 represses the IRF-1 effects. These findings emphasize the dual function of the IRF-responsive cis-elements as positive and negative regulators, since they can be occupied by transcriptionally active or inactive IRF molecules. This type of regulatory mechanism might operate in other cytokine systems.

Animals↗

PubMed1990

A single dose-response effect of aflatoxin B1 on rapid liver cancer induction in two strains of rats.

To investigate rapid liver cancer induction in rats by aflatoxin B1 (AFB1), different single oral doses of AFB1 were given to 3 groups of 1-year-old Buffalo and Wistar rats. The animals were treated once and all survivors were killed 6 weeks later. Control animals received an equal volume of solvent (DMSO), and both groups of animals were maintained under identical conditions throughout the period of experiment. The survival rates were 40% with low and medium doses in AFB1-treated Buffalo and Wistar rats, and 0% in the high-dose Buffalo rats. Slight ante-mortem elevations in serum concentrations of glutamic pyruvic transaminase (SGOT) and glutamic oxaloacetic transaminase (SGPT) were indicative of the persistent damage effect of AFB1 at week 6. Total protein and albumin concentrations were not altered. The percent incidence of altered cell foci (areas) and neoplastic nodules was higher in Wistar than in Buffalo rats given a similar low dose. Various stages of well differentiated hepatocellular carcinomas (0.1-0.2 cm in diameter) developed in 3 of 8 Wistar rats. It thus appears that Wistar rats are more susceptible to hepatocarcinogenesis following a single oral dose of AFB1 than Buffalo rats.

Aflatoxin B1↗

PubMed1990

Establishment of a human undifferentiated thyroid cancer cell line producing several growth factors and cytokines.

A cell line was established from undifferentiated giant cell carcinoma of the thyroid. The authors obtained cells from a 44-year-old patient admitted because of a rapidly growing anterior neck mass. The patient had significant leukocytosis and hypercalcemia shortly before her death. An autopsy revealed epidermoid metaplasia of the tumor cells. The cells (HTC/C3) had lost most of their differentiated functions. However, their thyroid nature was shown by peroxidase staining and by enzyme-linked immunostaining with Hashimoto patients' sera. The tumor extract was found to contain parathyroid (PTH)-like activity. Significant amounts of colony stimulating factor (CSF), which was further defined to be GM-CSF, and interleukin-1 alpha (IL-1 alpha) were detected in the conditioned media. Epidermal growth factor (EGF) binding to the HTC/C3 showed rich EGF receptors. Furthermore, the conditioned medium inhibited the binding of 125I-mEGF to HeLa cells, and transforming growth factor (TGF) was found repeatedly in the media.

Adult↗

PubMed1990

Effect of glucagon on bile acid metabolism after resection of liver cancer in patients with cirrhosis.

After hepatectomy patients with cirrhosis and liver cancer may develop progressive hepatic dysfunction and eventually hepatic failure. Insulin and glucagon are often used to treat certain kinds of hepatic dysfunction and hepatic insufficiency. We investigated the effect of glucagon on bile acid metabolism and pancreatic endocrine function. In 7 patients with severe cirrhosis and cancer of the liver, 1 mg of glucagon was injected intravenously pre- and post-operatively, and total bile acids, C-AMP, and bile acid fractions were determined. In the pre-operative glucagon tolerance test, the C-AMP level rose from a baseline of 14 +/- 0.8 PMol/ml to 362 +/- 94 PMol/ml 30 min after the injection of glucagon (p less than 0.01); and the level of total bile acids decreased from a baseline of 28 +/- 9 microMol/ml to 11 +/- 3 microMol/ml 60 min after the injection of glucagon. The post-operative C-AMP level increased from a baseline of 13 +/- 1 PMol/ml to 192 +/- 58 PMol/ml level of 30 min after the injection of glucagon (p less than 0.01), and the post-operative level of total bile acids decreased from a baseline of 64 +/- 20 microMol/ml to 26 +/- 7 microMol/ml 60 min after the injection of glucagon. There was a significant correlation between the 5-min increment ratio of C-AMP and the decrement ratio of total bile acids (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Bile Acids and Salts↗

PubMed1990

Assessment of antimicrobial penetration into the pancreatic juice in dogs.

The pancreatic ductal penetration of piperacillin, cefuzonam, fosfomycin and netilmicin, injected intravenously, was studied in four dogs with chronic pancreatic fistula. Serum and pancreatic juice were collected simultaneously, frozen, and later assayed for antibiotic concentration. Each antibiotic achieved its therapeutic serum level. The pancreatic ductal levels of piperacillin and cefuzonam were therapeutic, in contrast, the fosfomycin and netilmicin levels were subtherapeutic. These results are considered to be of interest in prevention and treatment of pancreatic infections.

Animals↗

PubMed1990

[Clinical studies on hypercreatine phosphokinasemia in emergency diseases].

Unexplained serum creatine phosphokinase (CPK) elevation is not a rare clinical problem, especially in emergency diseases. We studied hypercreatine phosphokinasemia (hyper-CPK-emia) in 161 cases of emergency diseases. Correlations between CPK and various laboratory data, various conditions were investigated. The hyper-CPK-emia was found to obtain no correlations with GPT, GOT, LDH, creatinine and body temperature. For this reason, we could not discover the unknown factors of which contributed to elevate the serum CPK. The sources of the serum CPK in these diseases were concluded to be the skeletal muscle. This is based on the facts that CPK MM (muscle type) is specifically increased among the CPK isozymes. The elevation of serum CPK activity in emergency diseases was considered to result from muscle hypoxia due to severe stress and general circulatory failure.

Adolescent↗

PubMed1990

[Radiotherapy of carcinoma of the uterine cervix--high dose rate intracavitary irradiation using a linear source arrangement].

We analyzed the records of 339 patients with squamous cell carcinoma of the uterine cervix. The patients were treated by irradiation alone in the period of 1973-1985 with external and high-dose rate intracavitary irradiation using linear source arrangement. The reason for using the linear source arrangement was to ensure the position of source as well as to simplify the technique of intracavitary irradiation. First, external irradiation was performed mainly with a dosage of 50Gy/25f four times a week or 50.4Gy/28f five times a week. Intracavitary irradiation was then carried out mainly with a dose of 30Gy/6f two times a week or 35Gy/7f two times a week and dose was indicated at point A. The 5-year survival rate of all 330 patients were 51.4%, and 55.1% for stage I (N = 19), 66.7% for stage II (N = 88), 47.1% for stage III (N = 212), 33.7% for stage IV (N = 20). Of the patients followed up for 24 months and found to have recurrence, 21.8% (39/179) had a recurrence in the pelvis and 22.1% (39/175) were found to have a distant metastasis. Of the patients followed up for over 24 months, 21.5% 932/149) developed intestinal complications and 12.2% (18/149) developed bladder complications. However complications Grade 2-4 were 5.4% for intestinal complications and 2.0% for bladder complications. From these results high-dose-rate intracavitary irradiation using a linear source arrangement was considered to be an effective treatment of carcinoma of the uterine cervix and to produce a standard results of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Effect of intravenously administered fat emulsion on liver function in totally depancreatized dogs.

Total Pancreatectomy was performed under nembutal anesthesia in 16 adult mongrel dogs after a 24-hour fast, and the depancreatized dogs were given parenteral nutrition containing fat emulsion. Serum lipids, intravenous fat tolerance and post-heparin lipolytic activity were determined and liver biopsy was done to demonstrate the presence or absence of fatty liver. The animals were divided into three groups: group A (n = 6) received fat emulsion 1 g/kg/day; group B (n = 5), fat emulsion 2 g/kg/day; and group C (n = 5), no fat emulsion. Blood levels of cholesterol and phospholipid were increased in group B, while only a mild elevation of the blood triglyceride (TG) level was noted in group A. In group C, cholesterol and phospholipid levels were decreased, and hypoglycemia was liable to occur. The rate of disappearance of blood fat (K2) was decreased two weeks after surgery in group B, but there were no significant change in the other two groups. These findings suggest that if insulin is present, the administration of fat emulsion will not cause fatty liver.

Animals↗

PubMed1990

The effect of the left ventricular assist device on the myocardium during reperfusion after coronary artery occlusion.

The effect of the left ventricular assist device (LVAD) during reperfusion after acute coronary occlusion was evaluated in a canine experimental model. The left circumflex artery was occluded for one hour, then reperfused for six hours immediately after removal of the occluder. Sixteen mongrel dogs were divided into the following two groups; a control group comprised of 7 dogs not given the LVAD support and another group comprised of 9 dogs (the LVAD group) assisted by LVAD for five hours during reperfusion. Throughout the study period, there was no significant difference in heart rate, aortic pressure or PA pressure between the two groups. However, LA pressure was significantly lower, while cardiac output, LV dp/dt, and LVSW were significantly higher in the LVAD group compared to the control group. Regional myocardial blood flow in the LCx area was significantly decreased after LCx occlusion in both groups but in the LVAD group, it recovered to the same level as before LCx occlusion after the beginning of reperfusion, while in the control group it remained significantly low throughout reperfusion. The LVAD group showed a positive myocardial lactate extraction in the early reperfusion period however, there was persistent lactate production in the control group. Thus, the unloading effect of LVAD during reperfusion after acute coronary artery occlusion improved regional myocardial blood flow and myocardial lactate metabolism and consequently, left ventricular function showed better recovery even after weaning from the LVAD support.

Animals↗

PubMed1990

Effect of combined dopamine and bunazosin on the ischemic heart after occlusion of the coronary artery.

In order to investigate whether dopamine combined with bunazosin improves cardiac function, the global and regional cardiac function and regional blood flow of 7 anesthetized dogs were analyzed before and after occlusion of the left anterior descending coronary artery (LAD), then after 10 micrograms/kg/min dopamine infusion following the LAD occlusion, and again after a bolus infusion of bunazosin 250 micrograms/kg. Dopamine with bunazosin reduced left atrial pressure from 4.9 +/- 0.9 to 3.1 +/- 0.5 mmHg (p less than 0.05) and improved cardiac output from 1.22 +/- 0.15 to 1.50 +/- 0.14 L/min (p less than 0.05), maximum positive left ventricular dp/dt from 1721 +/- 202 to 3600 +/- 663 mmHg/sec (p less than 0.05) and the time constant from 45.2 +/- 5.0 to 27.5 +/- 4.6 msec (p less than 0.01). Bunazosin added to the dopamine reduced the elevated left ventricular peak systolic pressure caused by dopamine from 130 +/- 7 to 113 +/- 8 mmHg (p less than 0.01). With regard to the regional wall motion, the impaired LAD-delta L (the segment systolic shortening) and LAD-Elmax (the slope of peak systolic pressure--endsystolic length relation) following the LAD occlusion improved from 0.5 +/- 2.5 per cent to 5.9 +/- 2.6 per cent (p less than 0.01) and from 50 +/- 9 to 82 +/- 14 mmHg/mm (p less than 0.01) after the infusion of dopamine with bunazosin. Dopamine greatly increased the Rate Pressure Product (RPP) from 12610 +/- 1120 after LAD occlusion to 16950 +/- 1420, whereas dopamine in combination with bunazosin did not increase the RPP due to a drop of LV-PSP with little change in regional myocardial blood flow. It was concluded that combining dopamine with bunazosin was useful for improving both the global and regional cardiac functions of the ischemic heart.

Adrenergic alpha-Antagonists↗

PubMed1990

Clinical trial of nicardipine cardioplegia in pediatric cardiac surgery.

To clarify the effectiveness of nicardipine, one of the dihydropyridine calcium-channel blockers, for myocardial protection during cold potassium cardioplegic arrest in pediatric cardiac surgery, a clinical trial of nicardipine (0.25 mg/L) added to potassium cardioplegic solution was performed in children undergoing surgical repair of congenital heart diseases. Twenty patients were selected to receive nicardipine cardioplegia and 13 patients received a standard potassium cardioplegia, serving as a control group. Nicardipine cardioplegia provided better cardiac performance in the early postoperative period and reduced release of the MB isozyme of creatine kinase, as determined during a 48-hour postoperative period. These results suggest that nicardipine added to cold potassium cardioplegic solution offers additional protection for the myocardium during ischemia and postischemic reperfusion in pediatric cardiac surgery.

Blood Pressure↗

PubMed1990

Idebenone attenuates neuronal degeneration induced by intrastriatal injection of excitotoxins.

Previous studies with the N18-RE-105 neuronal-like cell line and primary cortical cultures demonstrate that glutamate can produce a calcium-dependent, delayed form of neuronal degeneration that results from its competitive inhibition of cystine transport, which leads to cellular glutathione depletion and death by oxidative stress. Idebenone, a centrally active antioxidant used to treat multiinfarct dementia, protects cells from this form of glutamate-induced cytotoxicity in vitro. In the present study, we have examined the effects of systemic treatment with idebenone on the neurotoxic consequences of intrastriatal injection of kainic acid, quisqualic acid, or quinolinic acid, an NMDA receptor agonist, on neuronal degeneration. Striatal damage was assessed by quantitative neurochemistry with measurement of choline acetyltransferase activity and glutamate decarboxylase activity, by histochemical analysis for acetylcholinesterase and NADPH diaphorase staining and by behavioral assessment of circling produced by systemic apomorphine treatment 10 days after the unilateral lesion. The results indicate that treatment with idebenone provides significant protection against the neuronal degeneration induced by intrastriatal injection of kainic acid and quisqualic acid, but not the NMDA receptor agonist, quinolinic acid. The results suggest that oxidative stress may contribute to the proximate cause of neuronal degeneration induced by quisqualate and by kainate receptor agonists and that the mechanisms of neuronal degeneration caused by quisqualate/kainate receptor agonists differ from those associated with NMDA receptor agonists.

Animals↗

PubMed1990

Mechanisms of blood coagulation induced by latex particles and the roles of blood cells.

Latex particles with highly negative or positive charges shortened the clotting time of whole blood and platelet-rich plasma and activated platelet factor 3. Platelet-poor plasma was clotted by the particles with a highly negative charge, but not by those with a positive charge, except hydrophobic particles. Blood coagulation by positively-charged particles was attributed to platelet activation. An enhancement of blood coagulation was also observed in the presence of erythrocytes, leucocytes, their cell membranes or negatively charged phospholipids, and phosphatidylserine instead of platelets. Hydrophilic and low-charged particles suppressed blood coagulation.

Biocompatible Materials↗

PubMed1990

Interleukin-2 production of T cells in atopic dermatitis.

Patients with atopic dermatitis (AD) were treated with Tranilast, Interleukin-2 (IL-2) (production of T cells in vitro) and blood histamine values, before and after Tranilast therapy, were measured, and the following results were obtained: 1) Compared with healthy controls, the IL-2 producing ability of T cells in patients with AD was increased. 2) After Tranilast therapy, IL-2 production of T cells in AD decreased in quantity to the control level. 3) Skin lesion severities of AD were correlated with the quantity of IL-2 production of T cells. 4) Serum histamine levels were not significantly different between AD patients and healthy controls, before or after Tranilast therapy.

Adult↗