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Biomedical subjects

K Kumada

Publications and source records attributed to K Kumada.

At least 145 records · Page 8Linked to original sources
PubMed1989

[Cholecystolithotripsy using extracorporeal shock waves].

Extracorporeal shock-wave lithotripsy (ESWL) was first applied for calculi of the bile duct system in 1985. Recent improvement of the crushing apparatus has enabled us to crush the biliary calculus more accurately than before, and moreover, to conduct the procedure without anesthesia, and to treat easily. We performed ESWL in 30 cases of calculus in the cholecyst using MPL-9000 (Dornier Co., Ltd.) which is said to be a crushing device of a new generation. Here, the study is presented. The results of crushing effect demonstrate the efficacy in 26 of 30 cases (87%), and disappearance rate in 18 cases (60%) at present after an average follow-up period of 4.4 months. The disappearance cases were mainly those with a single calculus (75% disappearance rate) or pure cholesterol calculus (100%). Concerning the complications, right upper abdominal pain which was expected to accompany excretion of the crunched fragments was recognized in 10 cases (33%), it was not seen in cases in which laparotomy or endoscopic papillotomy was performed.

Adult↗
PubMed1989

Closure of interposition mesocaval shunt in a case of idiopathic portal hypertension.

Interposition mesocaval shunt for hemorrhagic esophageal varices was carried out in a patient with idiopathic portal hypertension without preoperative hepatic dysfunction. The esophageal varices were controlled, but the hemodynamics of the portal vein subsequently underwent gradual change and attacks of hepatic encephalopathy occurred frequently the following year. Therefore, the shunt was closed after about 2 yr. Hepatic encephalopathy disappeared after this surgery, but the varices obviously worsened on the 5th postoperative day and bled spontaneously on the 33rd postoperative day. A distal splenorenal shunt constructed 35 days after the operation resulted in the reduction, but not the complete disappearance, of esophageal varices. Episodes of hepatic encephalopathy or bleeding from the esophageal varices were not observed in the 24 months following the second shunt surgery.

Adult↗
PubMed1989

Estimation of postmortem interval using kinetic analysis of the third component of complement (C3) cleavage.

To estimate postmortem interval (PMI), spontaneous cleavage of the third component of complement (C3) was studied in aged blood and cadaveric blood by crossed immunoelectrophoresis. Using the kinetics of C3 cleavage in vitro described as dC/dt = -kC, where C is the concentration of native C3 at time t and k is a first-order rate constant, Arrhenius' equation, and another equation which assumes a linear drop of body temperature after death, the percentages of C3 cleavage were calculated. There was a significant positive correlation between the calculated percentages and the measured percentages of up to 10% in cadaveric blood. We found that the comparison between the calculated percentage of C3 cleavage for each optional postmortem interval and the measured percentage of up to 10% in cadaveric blood leads to the estimation of PMI. This approach is one step towards the development of an accurate method for determining PMI based on C3 cleavage, that is, on a first-order reaction.

Blood Protein Electrophoresis↗
PubMed1988

Positive imaging of venous thrombi and thromboemboli with Ga-67 DFO-DAS-fibrinogen.

A newly developed thrombus imaging agent, 67Ga-DFO-DAS-fibrinogen (67Ga-fibrinogen), was used for 22 studies in 20 cases of suspected deep venous thrombosis. Increased accumulation of 67Ga-fibrinogen in venous thrombi was depicted at 48 h after injection in 10 of the 15 cases (10 of 17 studies) who showed abnormal findings in radionuclide venography. A hot spot in the lung emboli was visualized in two cases. Seven of the eight cases having anticoagulant therapy showed increased 67Ga-fibrinogen uptake, while follow-up 67Ga-fibrinogen scintigraphy after the administration of heparin and urokinase did not reveal an abnormal hot spot in one case. 67Ga-fibrinogen can be made available simply by adding 67Ga solution to a vial containing fibrinogen-DAS-DFO conjugate. In conclusion, 67Ga-fibrinogen is considered to be a promising agent for detecting active venous thrombi and to assess the effect of anticoagulant therapy.

Adult↗
PubMed1988

Physiological effects of portal ligation on the longitudinal and circular muscles of the dog portal tree.

We studied physiological effects of portal vein ligation on the longitudinal and circular muscles of the dog portal tree. Portal venous blood pressure after portal ligation was higher in dogs that died than in those that survived. The portal veins isolated from dogs that died after portal ligation exhibited both lower rate of onset and decreased intensity of spontaneous activity, compared with those from dogs that survived. Responsiveness of longitudinal muscles of each of the four portal segments to noradrenaline, acetylcholine, histamine and KCl was markedly reduced in dogs that died, compared with those that survived, although the responsiveness of circular muscle was nearly equal in both groups of dogs. The longitudinal muscle of the truncal portal vein from dogs that died responded less strongly to electrical transmural stimulation than that from surviving dogs. The nonadrenergic, noncholinergic response was almost abolished in dogs that died rapidly. The degree of spontaneous activity or responsiveness to various stimulations in smooth muscles of the portal tree is considered to reflect muscular development. The degree of development of the longitudinal muscle of the portal tree may determine the survival of dogs after portal ligation.

Acetylcholine↗
PubMed1988

A simple and direct approach to the portal triad structures for a left lobectomy or a left lateral segmentectomy.

The hilar isolation and dissection of portal pedicle is usually performed prior to hepatectomy in order to minimize blood loss intraoperatively. In some instances, it is difficult to visualize and encircle the bifurcation of the portal triad structures. We recommend the use of a simple and safe method of direct approach to the transverse portion of the portal vein in the left lobectomy or lateral segmentectomy, by incision and dissection of the ligament teres hepatis and continuing fatty tissue.

Common Bile Duct↗
PubMed1987

Preferential synthesis of diacyl and alkenylacyl ethanolamine and choline glycerophospholipids in rabbit platelet membranes.

In rabbit platelet membranes, the contents of alkenylacyl phospholipids (plasmalogen) were 56% of phosphatidylethanolamine and 3% of phosphatidylcholine. This uneven distribution of plasmalogens in each phospholipid class could be attributed to the different substrate specificity of ethanolaminephosphotransferase (EC 2.7.8.1) and cholinephosphotransferase (EC 2.7.8.2). The properties of the enzymes were studied, using endogenous diglycerides and CDP-[3H]ethanolamine or CDP-[14C]choline as substrates. The newly formed phospholipids were mainly diacyl and alkenylacyl and only rarely alkylacyl type. The ratios of the labeled alkenylacyl to diacyl type of phospholipids clearly varied with the concentrations of CDP-ethanolamine or CDP-choline. When 1, 10, and 30 microM CDP-[3H]ethanolamine were used, the labeled phospholipids contained 53, 37, and 27% of the alkenylacyl type, respectively. The apparent Km for CDP-ethanolamine to synthesize alkenylacyl and diacyl types were 2.2 and 8.1 microM. On the other hand, when 1, 10, and 30 microM CDP-[14C]choline were used, the labeled lipids contained 10, 17, and 24% alkenylacyl type, respectively. The apparent Km for CDP-choline to synthesize alkenylacyl and diacyl types were 24 and 4.3 microM. Further, the syntheses of diacyl type of phosphatidylethanolamine and the alkenylacyl type of phosphatidylcholine were markedly inhibited by unlabeled CDP-choline and CDP-ethanolamine, respectively. The two enzymes had opposite substrate specificities, and ethanolaminephosphotransferase showed a high preference to plasmalogen synthesis, especially in the presence of CDP-choline.

Animals↗
PubMed1987

Ultrasonic Doppler duplex study of hemodynamic changes from portosystemic shunt operation.

The portal hemodynamics were studied in ten patients with portal hypertension, including three patients who had interposition mesocaval shunt (IMCS), three patients who had distal splenorenal shunt (DSRS), one patient who had gastrocaval shunt (GCS), and three patients who had splenectomy. Portal blood flow was measured by an ultrasonic Doppler duplex system, and portal venous pressure was measured by portal catheterization before, during, and after operation. The portal blood flow, and especially the splenic venous blood flow, was less during operation than before operation. Blood flow through the IMCS was greater than that through the DSRS, and the shunt flow had a tendency to increase after operation. The portal venous pressure measured during operation was slightly higher than that measured percutaneously before operation. In the patients who had the shunt operation, the portal venous pressure tended to decrease after operation. Study of portal hemodynamics, especially with the ultrasonic Doppler method, is useful in analysis and follow-up of patients who have shunt operations since the same method can be used before, during, and after operation.

Adult↗
PubMed1987

Regional differences of reactivity to stimulants in the dog portal tree.

We studied the regional differences both of reactivity to various stimulants and of neurogenic responses elicited by transmural stimulation in the longitudinal and circular muscles of the truncal portal vein, mesenteric vein, splenic vein and gastric vein of the dog portal tree. Strong spontaneous activity appeared in the longitudinal muscle of the truncal portal vein (96% of preparations tested). Weak spontaneous activity sometimes appeared in the circular muscle of the truncal portal vein (41%) and rarely in the longitudinal muscle of the mesenteric vein (12%). It did not appear in other segments. The splenic vein and the gastric vein showed similar patterns in the relationship between resting tension and response to noradrenaline; that is, the responsiveness of either longitudinal or circular muscle of these two veins increased and then decreased almost parallel as resting tension increased and reached a maximum under the same resting tension. The longitudinal muscle of both the truncal portal vein and the mesenteric vein was more responsive to noradrenaline, acetylcholine, histamine and KCl than the circular muscle; for example 2.02 and 1.44 times more responsive to noradrenaline, respectively. On the other hand, the longitudinal muscle of the splenic vein and the gastric vein responded less well than the circular muscle; for example 0.36 and 0.16 times as responsive to noradrenaline, respectively. Acetylcholine and histamine caused marked contractions which were comparable to those elicited by noradrenaline in the longitudinal muscle of the truncal portal vein. Acetylcholine also elicited similar contractions in the longitudinal muscle of the mesenteric vein but the responses induced in preparations of other segments were small. 6 The longitudinal muscle of the truncal portal vein responded well even to low-frequency stimulation of 2 Hz, while the circular muscles of the truncal portal and splenic veins gave marked responses only to high-frequency stimulation of 10 or 20 Hz or more. These contractile responses were attenuated by phentolamine (10-6 M) or atropine (10-6 M). The longitudinal muscle of the splenic vein showed no significant response to stimuli of any frequency. 7 It seems that the portal tree receives not only adrenergic but also cholinergic innervation. In addition, the longitudinal muscle of the truncal portal vein may receive non-adrenergic, noncholinergic innervation as well. 8 The longitudinal muscle of the portal vein may be crucial to venous return in assisting movement of the blood it contains. If this is the case in man, then the regional differences in the portal tree demonstrated in this study may explain why varicose changes during portal hypertension occur preferentially in the oesophagogastric region and rarely in other regions, as blood stasis may occur more readily in the regions of the gastric and splenic veins where the longitudinal muscle is not very active.

Acetylcholine↗
PubMed1987

Platelet aggregability and platelet volume in the postoperative course: problems in the platelet aggregation test derived from the measurement of platelet volume.

Platelet count, aggregability and volume in the postoperative course of 20 patients were examined. Platelet count was decreased on the 1st postoperative d, and increased on the 7th and 14th d compared with the preoperative value. The maximal aggregation rate of platelets induced by ADP was decreased on the 3rd postoperative d, and then recovered to the preoperative level. In contrast, platelet volume was only slightly increased on the 3rd postoperative d. In this study, there was no correlation between platelet aggregability and platelet volume in PRP. We have proposed one parameter, 'platelet concentration ratio' (platelet concentration in PRP/platelet concentration in whole blood). In the postoperative course, this concentration ratio changed depending on platelet volume, and possibly on other conditions of blood such as hematocrit, viscosity and specific gravity. The concentration ratio influenced the subpopulations of platelets in PRP. Platelet aggregation tests may be performed using PRP in which platelet subpopulations differ from those in whole blood, especially in the postoperative state.

Adult↗
PubMed1987

[Granulopoietic effects of lentinan, an antitumor polysaccharide in BALB/c nude mice].

The effect of lentinan on granulopoiesis in BALB/c nude mice (Nu/Nu) was compared with that in their heterozygotes (Nu/+). Lentinan-injected Nu/+ showed enhanced serum colony-stimulating activity (CSA), and increased diphasically granulocyte-macrophage colony forming cells (GM-CFC) in bone marrow and spleen (i.e., first peak on day 1-2 and second peak on day 6). On the other hand, in Nu/Nu, lentinan did not enhance serum CSA, although the control level was higher than the enhanced level in Nu/+. Monophasic increase in GM-CFC was observed in Nu/Nu, but the second peak seen in Nu/+ was not observed. Reconstitution of Nu/+ splenocytes to Nu/Nu increased GM-CFC on day 6, and the increase was augmented by lentinan administration. These results suggest that mature T-cells participate in regulation of granulopoiesis in vivo and that lentinan augments granulopoiesis at least in part via mature T-cell populations.

Animals↗
PubMed1987

[Granulopoietic effects of lentinan in mice: effects on GM-CFC and 5-FU-induced leukopenia].

C57BL mice were injected intravenously with an antitumor immunopotentiating polysaccharide, lentinan, to assess its effect on granulopoiesis in normal mice as well as its ability to enhance the recovery from leukopenia induced by 5-fluorouracil (5-FU). Lentinan increased neutrophils and monocytes in peripheral blood as well as granulocyte-macrophage progenitor cells (GM-CFC) in spleen and bone marrow. Administration of 5-FU induced a significant decrease in GM-CFC from day 1 to day 6, and thereafter the number of GM-CFC rebounded. The administration of 5-FU also suppressed white blood cells such as neutrophils, monocytes and lymphocytes. Injection of lentinan one day after 5-FU resulted in prompt restoration of the leukopenia through the recovery of neutrophils, monocytes and lymphocytes as well as prompt and marked rebound of GM-CFC. These results suggest that lentinan may contribute to the recovery from some of the hematopoietic depression in clinical chemoimmunotherapy.

Animals↗
PubMed1986

Stimulatory effect of calmodulin antagonists on phospholipid base-exchange reactions in rabbit platelet membranes.

The properties of Ca2+-dependent incorporation of [3H]serine, [3H]ethanolamine and [3H]choline into the corresponding phospholipids mediated by base-exchange enzymes in rabbit platelet membranes were studied in the presence or absence of the calmodulin antagonists chlorpromazine, trifluoperazine and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), all of which markedly activate three base-exchange reactions. The base-exchange activities were dependent on Ca2+ both in the presence and absence of the drugs. Other metal ions tested did not stimulate the base-exchange reactions, even in the presence of the drugs. Apparent Km values for serine, ethanolamine and choline were not affected significantly by the concentration of Ca2+, with or without the drugs. [3H]Serine incorporation into phospholipid was competitively inhibited by ethanolamine and choline, [3H]choline incorporation was competitively inhibited by serine and ethanolamine, whereas [3H]ethanolamine incorporation was competitively inhibited by serine and noncompetitively by choline. These competitive and noncompetitive relations between each base were also not affected by the drugs. The amount of 45Ca2+ binding to platelet membranes was decreased by the drugs dose dependently. A weaker calmodulin antagonist, N-(6-aminohexyl)-1-naphthalenesulfonamide (W-5), only slightly stimulated the base-exchange reactions, but did clearly inhibit 45Ca2+ binding to the membranes, in the same manner as that of the other calmodulin antagonists used. The concentration of chlorpromazine, trifluoperazine, W-7 and W-5, required to produce half-maximal inhibition of Ca2+ binding, was approximately 30 microM. These results suggest that the calmodulin antagonists used activate the base-exchange reactions only in the presence of Ca2+ without changing the affinity of each free base to base-exchange enzymes. The activation of the base-exchange reactions was not due to the increase in free Ca2+ caused by the drug-induced inhibition of Ca2+ binding to platelet membranes.

Animals↗