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Biomedical subjects

M Kainuma

Publications and source records attributed to M Kainuma.

At least 37 records · Page 2Linked to original sources
PubMed1992

The effect of dobutamine on hepatic blood flow and oxygen supply-uptake ratio during enflurane nitrous oxide anesthesia in humans undergoing liver resection.

Liver surgery is often accompanied by hepatic hypoperfusion and hypoxia, and it is controversial whether catecholamines increase hepatic blood flow and oxygen supply. The effects of 3 micrograms.kg-1.min-1 dobutamine on hepatic circulation and oxygen balance were examined in patients anesthetized with enflurane, nitrous oxide, and oxygen for liver surgery. Dobutamine did not cause a significant increase in hepatic arterial blood flow. However, total hepatic blood flow and portal venous blood flow were increased, resulting in an increase in hepatic oxygen delivery (HDO2). The increase in HDO2 was not associated with an improvement of hepatic oxygen supply-uptake ratio, since hepatic oxygen uptake (HVO2) also increased. After hepatectomy, the increases in portal venous blood flow and HDO2 were not accompanied by an increase in HVO2. The stimulation of hepatocellular oxygen metabolism by dobutamine and depressed responsiveness of adrenoceptors on hepatocytes in which metabolism was already augmented are the likely explanation for the different reactions before and after hepatectomy.

Adult↗
PubMed1991

Monitoring hepatic venous hemoglobin oxygen saturation in patients undergoing liver surgery.

Hepatic venous oxygen saturation (ShvO2) was continuously monitored in 33 consecutive patients undergoing hepatic lobectomy. Fiberoptic pulmonary artery catheters were inserted into the hepatic vein (HV) and in the pulmonary artery through the right internal jugular vein before anesthetic induction. The success rate and mean time for HV catheterization were 100% and 14 min, respectively. The only complication of the procedure was nonsustained atrial or ventricular arrhythmias. Eighteen patients showed decreases in ShvO2 to less than 30% at skin incision, at temporary cessation of hepatic inflow, and/or at surgical manipulation of the liver. Clinical HV catheterization was easy to accomplish and may be a valuable technique in studying the extent and significance of hepatic ischemia during liver surgery.

Aged↗
PubMed1990

Effect of acute changes in renal arterial blood flow on urine oxygen tension in dogs.

The relationships between urine oxygen tension (PuO2), PaO2, and acute changes in renal arterial blood flow (RBF) were studied in 19 anesthetized dogs. Indwelling sensors that measure continuously PO2 were inserted into the femoral artery and the ureter. RBF was measured by an electromagnetic flowmeter placed over the renal artery. PuO2 increased significantly from 36 to 72 torr during a stepwise increase in PaO2 from 70 to 180 torr. RBF was decreased in a stepwise fashion from a baseline value of 5.51 to 4.16, 2.13, and finally to .20 ml/kg.min by aortic constriction. PuO2 decreased significantly from a baseline value of 72 torr to 66, 57, and finally to 23 torr. The correlation coefficient between RBF and PuO2 was .84, which was significantly higher than that between RBF and femoral arterial pressure or that between RBF and urinary flow rate. This study demonstrates that PuO2 is a sensitive indicator of acute RBF changes in normal, healthy dogs.

Animals↗
PubMed1990

Electroporation-transformation system for coryneform bacteria by auxotrophic complementation.

We evaluated electroporation as an alternative system for genetic exchange for one of the coryneform bacteria, Brevibacterium flavum MJ233. The maximum number of transformants, 6 x 10(4) cells, was obtained when cells were cultured with Penicillin G (1 U/ml) and harvested at the middle-log phase. Electroporation was done using 12.5 kV/cm of pulse field strength, 1 x 10(10) cells, and 1 microgram of plasmid DNA. Other coryneform bacteria, Brevibacterium lactofermentum ATCC 13869, Corynebacterium glutamicum ATCC 31830, and B. stationis IFO 12144 were also transformed by electroporation. Electroporation has the advantage that intact cells can be used as host cells without the need for protoplast formation and regeneration. Moreover, minimal medium can be used, so auxotrophic complementation of the transformants is possible.

Brevibacterium↗
PubMed1988

Use of pulse oximetry for monitoring tracheostomy tube obstruction.

Experimental studies were performed on dogs for monitoring postoperative tracheostomy tube obstruction using a pulse oximeter. While a 25% obstruction of the cross-sectional area of the tube did not alter the oxygen saturation, obstruction of 40% and above resulted in a drop in the oxygen saturation level which corresponded to the degree of obstruction. The greater the degree of obstruction, the sooner was the fall of oxygen saturation. Therefore a pulse oximeter could be effectively put to use to monitor tracheostomy tube obstruction.

Animals↗
PubMed1988

Factors influencing fibrin-induced pulmonary edema.

Effects of depth of anesthesia, pH of fibrinogen and thrombin, and interventions in the vagus nerves on the development of fibrin-induced pulmonary edema were examined in the rat. Rats were anesthetized with an intraperitoneal injection of pentobarbital sodium, 25 or 50 mg/kg. Solutions of fibrinogen and thrombin at the same pH were separately injected into the cisterna magna. The pH values were adjusted to 6.5 or 8.5 with Tris buffer. Interventions in the vagus nerves, which consisted of atropine administration at a dose of 1 mg/kg, i.v. or bilateral vagotomy, were performed before the intracisternal injection of fibrinogen and thrombin. Animals in which no interventions in the vagus nerve was performed were designated as intact rats. Lung-water ratio was calculated as a ratio of the difference between wet and dry lung weight to dry lung weight. Incidences of pulmonary edema and lung-water ratios were lower under deep anesthesia than under light anesthesia. Both parameters were low in the vagotomized rats treated under deep anesthesia with fibrinogen and thrombin at a pH of 8.5, as compared to those treated similarly at pH 6.5. This phenomenon was not observed under light anesthesia. Interventions in the vagus nerves influenced the development of pulmonary edema to various degrees, depending on the pH values of the injected fibrinogen and thrombin. As suggested from these results, well-defined, specific conditions are required for investigating the mechanism triggering the development of fibrin-induced pulmonary edema.

Anesthesia↗
PubMed1988

Effects of isosorbide dinitrate on thromboxane A2 synthesis in carbon dioxide exposed platelets.

Isosorbide dinitrate (Nitorol R, 100 nmol/l) blocked an increase in thromboxane B2 concentration in human platelet-rich plasma caused by exposure to high CO2 tension, in the presence of arachidonic acid. Thromboxane B2 concentrations obtained at 1 or 2 mmol/l or arachidonic acid were not influenced by isosorbide dinitrate at low CO2 tension. Inhibitory action of isosorbide dinitrate on the thromboxane A2 synthesis appears to have a close relation to the site of CO2 action.

Blood Platelets↗
PubMed1987

Isosorbide dinitrate blocks thromboxane synthesis caused by CO2 in dog heart-lung preparation.

Effects of isosorbide dinitrate (ISDN) on coronary flow and arterial prostaglandin (PG) concentrations were investigated, using dog heart-lung preparations. Two kinds of gases (low and high CO2 gases) were used for the artificial respiration. Low CO2 gas contained 55% O2 and 0.2% CO2, whereas high CO2 gas contained 55% O2 and 8% CO2. Administration of ISDN into a blood reservoir at high CO2 caused an increase in coronary sinus blood flow, which was blocked by indomethacin, but not at low CO2. In the absence of ISDN, the arterial concentration of thromboxane (TX) B2 was larger at high CO2 than at low CO2. ISDN attenuated such an increase in TXB2 concentration caused by CO2. The arterial concentration of 6-keto PGF1 alpha was altered by neither CO2 nor ISDN, but slightly increased with time. Indomethacin lowered the concentrations of 6-keto PGF1 alpha and TXB2. These results suggested that the arterial CO2 tension enhanced the TXA2 synthesis and that ISDN inhibited such a relation between CO2 and TXA2 synthesis. Additionally, the vasodilatory effects of PGI2 was enhanced by elevating the arterial CO2 tension. Thus, the increase in canine coronary flow at high CO2 in the presence of ISDN may be related to the inhibitory effects of ISDN on the TXA2 synthesis enhanced by the high arterial CO2 tension and the facilitatory effects of CO2 on the PGI2-induced vasodilation.

Animals↗
PubMed1987

Preoperative fiber-optic lung cancer detection. A case report.

A case of unexpected detection of bronchial neoplasm in routine general anesthesia is described. On the basis of this case, fiber-optic bronchoscopy in all patients undergoing general anesthesia as a means of early detection of lung cancer is discussed.

Anesthesia, Endotracheal↗
PubMed1986

Cervical epidural anaesthesia in carotid artery surgery.

The successful anaesthetic management using a cervical epidural technique is reported in three patients undergoing carotid artery surgery. Adequate analgesia was obtained in all cases and the adequacy of cerebral blood flow was easily judged by the patient's state of consciousness. Cervical epidural anaesthesia could be a safe and reasonable technique for the management of patients who need carotid artery surgery.

Aged↗