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Biomedical subjects

T Washizu

Publications and source records attributed to T Washizu.

At least 37 records · Page 2Linked to original sources
PubMed1995

The effect of indomethacin on liver blood flow and oxygen supply-uptake relationship in the dog.

The effects of indomethacin on liver blood flow and oxygen supply-uptake relationship were investigated using a right heart bypass technique. Portal venous blood flow was decreased by the mesenteric vascular effects of indomethacin, which produce intense mesenteric vasoconstriction. Hepatic arterial blood flow was increased and therefore, total liver blood flow was not significantly changed after indomethacin administration. Portal venous oxygen delivery was significantly decreased by reductions in both portal venous blood flow and portal venous oxygen content. Total liver oxygen delivery, however, was not changed after indomethacin administration. This response was caused by a large increase in hepatic arterial oxygen delivery. Liver oxygen uptake and liver oxygen extraction ratio were not changed after indomethacin administration. We conclude, therefore, that total liver blood flow and oxygen delivery were well maintained, even if the mesenteric vascular effects of indomethacin decreased both portal venous blood flow and portal venous oxygen delivery.

Animals↗
PubMed1995

The effects of dopamine and dobutamine on liver oxygen supply-uptake relationship in the dog.

The effects of dopamine and dobutamine in various doses on liver oxygen supply-uptake relationship were studied in 12 mongrel dogs. Dopamine 3 and 7 micrograms/kg/min infusion rates and dobutamine 5 micrograms/kg/min infusion rate did not produce any changes in total liver oxygen delivery. On the contrary, total liver oxygen delivery was increased at the 15 micrograms/kg/min dopamine in fusion rate and dobutamine 10 and 15 micrograms/kg/min infusion rates. The ratio of total liver oxygen delivery to the systemic oxygen delivery was increased at the 15 micrograms/kg/min dopamine infusion rate. Liver oxygen extraction ratio was decreased at the 15 micrograms/kg/min dopamine infusion rate and at the same rate of dobutamine. These decreases were due to the increases in oxygen delivery while both oxygen uptakes were avariant from control levels. The results of this study demonstrated that high dose of dopamine (15 micrograms/kg/min) and medium and high doses of dobutamine (10 and 15 micrograms/kg/min) should be useful to increase the liver oxygen delivery. However, these increases in liver oxygen delivery during dopamine and dobutamine infusion were not associated with an improvement in liver oxygen metabolism, since liver oxygen uptake was not changed.

Animals↗
PubMed1995

The selective effects of dopamine and dobutamine on liver circulation in the dog.

The selective effects od dopamine and dobutamine in various doses on liver circulation were studied in 12 mongrel dogs. Dopamine increased portal flow but decreased hepatic arterial flow markedly as infusion rate of dopamine increased. Dopamine 3 micrograms/kg/min infusion rate produced vasodilation in mesenteric vascular bed and the portal flow ratio to cardiac output was significantly increased. Dobutamine increased both portal and hepatic arterial flows at the 5 and 10 micrograms/kg/min dobutamine infusion rates, and decreased hepatic arterial flow at the 15 micrograms/kg/min dobutamine infusion rate. Both dopamine and dobutamine increased total liver flows, however, total liver flow ratio to cardiac output was not increased. Pressure gradient of portal system was not changed during dopamine and dobutamine infusion, since both portal venous pressure and hepatic venous pressure were avariant from control values. These findings suggest that congestive hyperemia was not occurred in intrahepatic portal vascular system when portal flows were increased during dopamine and dobutamine infusion. The results of this study demonstrate that both dopamine and dobutamine did not produce selective increases in total liver blood flow. In addition, both agents should be safe to use to the normal liver patient; total liver blood flow did not decrease and intrahepatic congestive hyperemia was not occurred when portal flow was increased.

Animals↗
PubMed1995

Effect of food on liver circulation in conscious dog.

Hepatic hemodynamics and the liver oxygen supply-uptake relationship, in response to eating, were investigated in a chronically catheterized conscious dog method. Portal venous pressure was significantly increased after eating, however was within the normal range reported previously. Hepatic venous pressure correlated well with portal venous pressure throughout the experiment, therefore, the pressure gradient of the portal system was unchanged. Hepatic venous oxygen content, correlated well with liver oxygen extraction, was unchanged after eating. Therefore, it is possible to assume that liver oxygen supply-uptake relationship is well maintained during digestion of food.

Animals↗
PubMed1994

Glucose transport and glycolytic enzyme activities in erythrocytes of two-year-old thoroughbreds undergoing training exercise.

D-Glucose transport and cytosolic enzyme activities were measured in erythrocytes from 2-year-old thoroughbreds under continuous training exercise (race horses) and compared with those from untrained horses of various ages (sires, mares and untrained 2-year-old thoroughbreds). The activities of the glucose transport and glycolytic enzymes, hexokinase and pyruvate kinase, in the race horses' erythrocytes were elevated to 2-3.5 times above those of untrained horses. There were no significant differences in plasma glucose, triglyceride or IRI concentrations between the horses in training and untrained horses. The increases in glucose transport and glycolytic enzyme activities in their erythrocytes are considered to reflect an increased metabolic activity in the race horses resulting from the training exercises.

Animals↗
PubMed1994

Transvenous retrograde angiography for detection of portal-caudal caval shunt.

A retrograde angiography method for the detection of a portosystemic shunt was studied. The retrograde angiography was done by compressing the caudal vena cava in the chest by applying pressure to the thoracic cavity, then feeding a contrast medium into the caudal vena cava without releasing the pressure loading. The angiography could detect shunt vessels in experimental cases as well as clinical cases. This method is useful for the confirmation of a portal-caudal caval shunt, which can be performed without technical difficulty and without the need for a special kind of catheter.

Angiography↗
PubMed1994

Changes in bile acid composition of serum and gallbladder bile in bile duct ligated dogs.

Biliary obstruction was produced by surgical ligation of the common bile duct to observe alterations in serum bile acid composition. The percent composition of serum bile acids was found to change with time. Taurocholic acid increased on day 3 and accounted for more than 90% of the total bile acids in all dogs, however it decreased after day 7. The percentage of taurochenodeoxycholic acid (TCDC) and taurodeoxycholic acid (TDC) decreased to 4.2-6.0% and 0.2-0.7% on day 3, respectively. However, the percentage of TCDC increased after day 7 in all dogs and reached greater than 20% on day 14 in 2 dogs, whereas the percent TDC after bile duct ligation remained low in all dogs. Glycolithocholic acid, which was not identified in normal dog sera, was detected on day 3 and remained throughout the study in all dogs. Bile acid composition of gallbladder bile sampled on day 35 was similar to the serum bile acid composition on the same day. This indicates that the bile acids refluxed into the circulation in these dogs. In the present study, total cholic acid to chenodeoxycholic acid (C:CDC) ratio increased to 15.5-22.3 at three days post bile duct ligation and after the day 14, the C:CDC ratio decreased to its pre-ligation value or below. In contrast, the glycine conjugated to taurine conjugated bile acids (G:T) ratio did not change. Therefore, at this time, the G:T ratio would not be usable as an indicator of liver disease in dogs while it may be possible to use the C:CDC ratio.

Animals↗
PubMed1994

Histopathology and viral antigen distribution in lymph nodes of cats naturally infected with feline immunodeficiency virus.

Lymph nodes from cats with natural feline immunodeficiency virus (FIV) infection were examined histopathologically for characterization of lesions in the symptomatic and terminal stages. The localization of viral antigen was also studied in the nodes by immunohistochemistry using a monoclonal antibody to FIV p24. In a node of persistent generalized lymphadenopathy stage, follicular hyperplasia was prominent and the viral antigen was demonstrated predominantly in the follicular lymphocytes and tingible body macrophages. In cats died at AIDS related complex stage, the lymph nodes showed either mixed follicular hyperplasia and involution, involution, or mixed involution and depletion. The lymph nodes in those died at AIDS stage showed considerable destruction of the nodal architecture with involution and depletion of lymphoid follicles. In this terminal stage, the viral antigen was seen prominently in histiocytes/macrophages of the sinus. These findings observed in the dead cats were similar to the lymph node changes seen in human AIDS associated with HIV infection. It was suggested that sequential histologic changes from follicular hyperplasia to depletion via involution took place in the FIV infected lymph node with persistence of FIV antigen.

Animals↗
PubMed1994

Cardiovascular effects of dibutyryl cyclic AMP and milrinone under right heart bypass in anesthetized dogs.

To compare the cardiovascular effects of dibutyryl cyclic AMP (DBcAMP) and milrinone, we used the right heart bypass method in intact anesthetized dogs. The preload of the left ventricle was maintained constant throughout the experiment. Therefore, the effects of DBcAMP and milrinone on cardiac contractility and afterload of the left ventricle were investigated respectively without preload influence. DBcAMP and milrinone exhibited marked positive chronotropic-, positive inotropic-, vasodilative- and diuretic-activity. DBcAMP expressed these effects gradually and continuously, whereas milrinone expressed its pharmacological actions rapidly, but for a short duration of time. Both the afterload-reducing and the cardiac contractile force-enhancing activities of DBcAMP were longer lasting than those of milrinone. Mean arterial pressure was not altered by DBcAMP infusion, whereas it was increased significantly (p < 0.05) by milrinone infusion. The results of this study suggested that DBcAMP appeared to be indicated when there is a need to increase cardiac output by reducing afterload and increasing cardiac contractile force gradually and continuously. On the other hand, milrinone would seem to be indicated when the goal is to raise blood pressure rapidly and to increase cardiac output simultaneously.

Animals↗
PubMed1993

Pathologic features of acquired immunodeficiency-like syndrome in cats experimentally infected with feline immunodeficiency virus.

Five specific pathogen free cats were inoculated with feline immunodeficiency virus (FIV) isolated in Japan to observe changes toward development of acquired immunodeficiency syndrome (AIDS)-like disease. All inoculated cats had lymphadenopathy and mild respiratory disease shortly after inoculation. Following the initial acute phase lasting for more than 40 weeks, the clinical signs gradually diminished in three animals, and the asymptomatic carrier (AC) stage was observed at 45 (1 cat) and 70 (2 cats) weeks postinoculation (p.i.). Two of the three cats developed respiratory signs and diarrhea at 105 or 106 weeks p.i. One cat died at 121 weeks p.i. with severe wasting, with necropsy findings consistent with AIDS-related complex (ARC). The others were surviving at 150 weeks p.i. with mild clinical signs or asymptomatic. Another group of two cats developed more severe illness without the AC phase. One died at 48 weeks p.i. with the ARC illness. The other cat developed marked emaciation with diarrhea at 75 weeks p.i., and died at 100 weeks p.i. with a histologic diagnosis suggestive of terminal immunodeficiency. Histologically, the lymph nodes showed serial changes toward the terminal illness, from follicular hyperplasia at the acute phase to the lymphoid depletion at the ARC and AIDS-like terminal stages. The FIV antigen was demonstrated in the lymph nodes. The virus was isolated from peripheral blood mononuclear cells of all the inoculated animals. These data demonstrated possible etiologic association of FIV with development of AIDS-like disorders in the cat.

Animals↗
PubMed1992

Long-term clinical observations on feline immunodeficiency virus infected asymptomatic carriers.

Eleven feline immunodeficiency virus (FIV) infected asymptomatic carrier (AC) cats were observed for 2 years for development of acquired immunodeficiency syndrome (AIDS). Four of the 11 (36.4%) showed progression of the clinical stage. Persistent generalized lymphadenopathy was noted in three cats as the first sign of illness after the AC phase, while the other showed lymphadenopathy with signs of AIDS-related complex. In all four cats the AIDS-related complex stage lasted for 10 months or longer, and two showed progression of the disease into AIDS. The two cats showing AIDS illnesses died within approximately 1 year after they had developed persistent generalized lymphadenopathy. Pathology confirmed the diagnosis of AIDS characterized by the presence of depletion lesions in the lymphoid organs, and of severe infections of an opportunistic nature. The overall mortality of FIV infected AC cats during a 2 year period was two out of 11 (18.2%). These cats showed decreased concanavalin A mitogen response of peripheral blood mononuclear cells as the disease progressed.

Animals↗
PubMed1992

D-glucose transport activities in erythrocytes and hepatocytes of dogs, cats and cattle.

1. The activities of D-glucose transport and hexokinase were investigated in erythrocytes or hepatocytes of dogs, cats and cattle. 2. The mean D-glucose transport activity in erythrocytes of dogs was 6.0 nmol/min/mg protein, half the value of hepatocytes. 3. The activities of D-glucose transport in erythrocytes and hepatocytes or hepatic hexokinase of cats were about one-third of those of dogs. 4. Cattle with low blood glucose concentrations showed considerably low activities of D-glucose transport and hexokinase, about one-third of those of dogs.

Animals↗
PubMed1992

Surgery of hepatic cysts in a cat.

A 2-year-old female Japanese domestic cat weighing 3.6 kg was presented due to marked abdominal distention and was diagnosed as hepatic cyst. The bile acid concentration of the hepatic cyst was as low as the serum bile acid concentration. The membrane of the cysts was excised from the edge of the compressed hepatic tissue and no other surgical manipulation was performed. This surgical procedure is simple and quick compared to hepatic lobectomy, however, it is necessary to evaluate the fluid of the cyst before performing this procedure.

Animals↗
PubMed1991

Serum bile acid composition of the dog, cow, horse and human.

The fractionation of serum bile acids was performed in the dog, cow, horse, and human by high performance liquid chromatography equipped with an immobilized 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD) column. There were significant differences in the bile acid compositions, conjugation patterns and quantities of each bile acid among these animals. Cholic acid was the major primary bile acid in the dog and cow, which constituted 62.9% and 83.5%, respectively, whereas chenodeoxycholic acid was the major acid in the horse and human, which constituted 68.4% and 46.3%, respectively. Taurine conjugates were predominant in the dog and horse, which constituted 94.4% and 85.3%, respectively, whereas glycine conjugates were predominant in the cow and human, which constituted 31.0% and 49.4%, respectively. Although there were several unidentified peaks, it was confirmed that they had a hydroxy group at the C-3 alpha position by chromatographing the samples without the 3 alpha-HSD column.

Animals↗