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Biomedical subjects

T Morimoto

Publications and source records attributed to T Morimoto.

At least 595 records · Page 33Linked to original sources
PubMed1988

Changes in blood volume and vascular compliance during body heating in rats.

The effects of hyperthermia on blood volume and effective vascular compliance were studied in control and heat acclimated rats (three weeks at 32 degrees C and 50% R.H.). Experiments were performed on conscious rats whose abdominal aorta and both jugular veins were cannulated. Continuous changes in blood volume (BV) were monitored by measuring 51Cr tagged erythrocyte dilution, using an arterio-venous extracorporeal shunt passing through a gamma counter. Total vascular compliance was calculated from the relation between changes in BV and central venous pressure during 10 min of infusion of saline at a rate of 1.6% body wt/10 min. Hyperthermia induced a significant blood volume expansion. This expansion was more pronounced in non-acclimated rats. Effective vascular compliance was similar in the normothermic, both non-acclimated and acclimated rats. However, while hyperthermia did not affect the vascular compliance of non-acclimated rats, it was decreased significantly in the acclimated hyperthermic rats. The data suggest that changes in vascular compliance play a role when rapid blood volume changes take place, especially in acclimated hyperthermic animals. The relations between changes in vascular compliance and heat induced redistribution of cardiac output are discussed.

Acclimatization↗
PubMed1988

Changes in the hormone dependency of DMBA-induced rat mammary tumors with reference to the effect of tamoxifen.

Tamoxifen was administered over a period of 4 weeks to 19 female Sprague-Dawley rats bearing 20 DMBA-induced mammary tumors. Consequently, 13 tumors (65.0 per cent) regressed and showed a reduction in their estradiol receptor (ER) and progesterone receptor (PgR) concentrations. In spite of subsequent treatment given to the rats bearing the regressed tumors, 6 new tumors occurred. The ER and PgR concentrations of these tumors were lower than those of the tumors before tamoxifen therapy, and histochemical study showed these tumors to be composed mostly of ER-negative cells. These results suggest that: (a) the hormone dependency of breast cancer is reduced by tamoxifen therapy; (b) breast cancers recurring during tamoxifen therapy show reduced hormone dependency.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1988

Radial artery graft for an extracranial-intracranial bypass in cases of internal carotid aneurysms. Report of two cases.

Two cases of internal carotid aneurysms, trapped and bypassed, by means of radial artery grafts are discussed. Neither case has permanent neurological deficit possibly because of an adequate blood supply via the radial artery graft bypass. Although the radial artery graft has been in common use among cardiac surgeons, it is still rare in the neurosurgical field. The advantage of the radial artery is discussed with comparison to other graft materials such as the saphenous vein and the superficial temporal artery. In properly selected cases, the radial artery graft is useful in preventing the ischemic damage caused by an aneurysm being trapped at the main arterial trunk.

Aneurysm↗
PubMed1988

Changes in concentrations of respiratory components and cytochrome oxidase activity in mitochondria obtained from carbon tetrachloride-induced cirrhotic rat liver.

1. Changes in the concentrations of respiratory components, phosphorylative activity, the cytochrome oxidase activity of mitochondria and the hepatic adenylate energy charge level (in situ) were studied in cirrhotic rat liver induced by carbon tetrachloride (CCl4). 2. In the cirrhotic liver mitochondria, concentrations of cytochrome a(+a3), cytochrome b, coenzyme Q9 and coenzyme Q10 increased significantly to 2.44 +/- 0.02 x 10(-10) (mean +/- SE), 1.37 +/- 0.05 x 10(-10), 25.57 +/- 0.47 x 10(-10) and 5.39 +/- 0.26 x 10(-10) mol/mg of mitochondrial protein, respectively, compared with 1.83 +/- 0.03 x 10(-10), 1.22 +/- 0.02 x 10(-10), 16.24 +/- 0.39 x 10(-10) and 1.81 +/- 0.07 x 10(-10) in normal rats [P less than 0.001 for cytochrome a(+a3), coenzyme Q9 and coenzyme Q10, and P less than 0.01 for cytochrome b]. 3. Concentrations of flavoprotein and pyridine nucleotides decreased significantly to 13.33 +/- 0.14 x 10(-10) and 45.68 +/- 1.59 x 10(-10) mol/mg of mitochondrial protein, respectively, compared with 14.79 +/- 0.33 x 10(-10) and 86.26 +/- 1.83 x 10(-10) in normal rats (P less than 0.001). There was no significant difference in the concentration of cytochrome c(+c1). 4. Cytochrome oxidase activity per unit of cytochrome a(+a3) increased significantly to 67.43 +/- 1.71 atoms O s-1 mol-1, compared with 55.77 +/- 1.16 in normal rats (P less than 0.001). By contrast, phosphorylative activity per unit of cytochrome a(+a3) decreased significantly in the cirrhotic liver to 10.40 +/- 0.36 s-1 compared with 13.43 +/- 0.49 in normal rats (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine Nucleotides↗
PubMed1988

Effects of perfusion pressure during flushing on the viability of the procured liver using noninvasive fluorometry.

The influence of perfusion pressure and flow rate on hepatic cellular viability was investigated in the procured liver using noninvasive pyridine nucleotide fluorometry, in relation to other metabolic indices such as nicotinamide adenine dinucleotide (NAD) concentration, adenine nucleotides, tissue ketone bodies, and mitochondrial phosphorylative activity. Rat liver was perfused at a controlled flow rate through the portal vein with a nonrecirculating open-end-design perfusion system driven by a roller pump using cooled oxygenized Euro-Collins' solution. The maximum pressures (mean pressure in parentheses) of experimental groups were 8 (5) mmHg, 15 (9) mmHg, 40 (25) mmHg, 80 (50) mmHg, 120 (73) mmHg, 240 (152) mmHg. The amplitude between oxidation and reduction levels (RxA) in the fluorometric trace, and the gradient or velocity of the trace curve from oxidation to reduction (RxV) were determined by the measurement of fluorescence from NAD phosphate, reduced form (NADPH) using a new fluorometric device. Other metabolic indices were measured after attainment of a fully oxygenated state. RxA decreased in accordance with the increase of pressure. Similar results were obtained in the changes of NAD concentration, total adenine nucleotides, and total tissue ketone bodies, possibly due to the wash-out of these metabolites. RxV decreased in inverse proportion to the increase of pressure. There were close positive correlations between RxV and tissue ketone body ratio (acetoacetate/3-hydroxybutyrate) (r = 0.793, less than 0.01), RxV and respiratory control ratio in isolated mitochondria (r = 0.617, P less than 0.05), RxV and state 3 respiration (r = 0.792, P less than 0.01), and RxV and phosphorylation rate (r = 0.833, P less than 0.01). These results suggest that perfusion pressure and flow rate can easily deteriorate the energy metabolism of the procured liver, and that the gravity-induced hydrostatic pressure presently used in procurement perfusion should be reevaluated on the basis of energy metabolism.

Animals↗
PubMed1988

Difference in rehydration process due to salt concentration of drinking water in rats.

Albino rats were thermally dehydrated (approximately 8% of body wt), divided into five groups, and given tap water or 0.2, 0.45, 0.9, or 2.0% NaCl solution ad libitum for 16 h. Rats given 0.9 or 0.45% NaCl solution regained fluid loss completely in 3-3.5 h, whereas those given 0.2% solution became fully rehydrated at 10 h. The rats in the tap water and 2.0% NaCl groups were only 78 and 59% rehydrated, respectively, within 16 h. Na balance was positive in the 0.9% NaCl group by about five times the amount of the cations lost during the dehydration period. A positive balance of Na was also observed in the 0.45 (approximately 250%) and 2.0% NaCl groups (300%), whereas the 0.2% NaCl group regained lost water and Na simultaneously at 10 h. With tap water, additional loss of cations was observed. These findings show that for the replacement of water due to thermal dehydration there is a range of NaCl concentration with which the rats can rehydrate with the mutual cooperation of thirst, salt appetite, and kidney function.

Animals↗
PubMed1988

Changes in energy metabolism of allografts after liver transplantation.

To evaluate the function of energy metabolism in allografts after liver transplantation, changes in hepatic energy charge levels, oxidative and phosphorylative activities of mitochondria and arterial blood ketone body ratio (acetoacetate/3-hydroxybutyrate; KBR) were studied in piglets. Hepatic energy charge levels decreased to 0.831 +/- 0.010 at 3 days and 0.836 +/- 0.009 at 3 weeks after operation compared to the preoperative value of 0.868 +/- 0.006 (p less than 0.01), and returned to 0.856 +/- 0.007 at 6 weeks. Mitochondrial oxidative and phosphorylative activities were moderately enhanced to 19.14 +/- 2.07 (10(-10) mol ATP/mg of mitochondrial protein/s) at 3 days and 20.89 +/- 1.72 at 3 weeks compared to the preoperative value of 16.74 +/- 2.36, and returned to 16.65 +/- 1.54 at 6 weeks. There was no significant difference in the concentrations of mitochondrial respiratory components, except in cytochrome c + c1. KBR decreased immediately at the beginning of the anhepatic phase and rapidly recovered to the preoperative level within 60 min after revascularization of allografts. There was no change in KBR during the postoperative course except in cases with clinical deterioration. From these results, it is suggested that the mitochondrial capacity for ATP synthesis was enhanced to compensate for the decreased energy charge level and that a decreased KBR is a sign of a critically deranged metabolic function in allografts.

Adenosine Triphosphate↗
PubMed1988

Effects of partial ischemia and reflow on mitochondrial metabolism in rat liver.

To clarify the effects of partial ischemia and reflow on the mitochondrial metabolism of the rat liver, the afferent vessels supplying the left lateral and left half of medial lobes were occluded and then reperfused after given time periods of ischemia (30, 60, 90 and 120 min, groups A, B, C and D, respectively). Samplings were taken at 0, 10 and 60 min after reperfusion. The energy charge levels of ischemic lobes decreased rapidly from 0.85 +/- 0.01 in the sham group to 0.38 +/- 0.11, 0.35 +/- 0.07 and 0.34 +/- 0.06 in groups B, C and D, respectively. The phosphorylative activities of mitochondria isolated from ischemic lobes decreased gradually along with the time of ischemia. The reversal of mitochondrial function and energy charge levels following reperfusion was noted in groups A and B. In nonischemic lobes, the phosphorylation rate (nmol ATP/mg/min) increased from 90 +/- 6 in sham group to 125 +/- 12 and 130 +/- 9; 131 +/- 5 and 130 +/- 6; 123 +/- 6 and 122 +/- 17, and 138 +/- 6 and 138 +/- 13 at 10 and 60 min after reflow in groups A, B, C and D, respectively (p less than 0.05). The energy charge level of nonischemic lobes decreased from 0.85 +/- 0.01 of sham group to 0.80 +/- 0.03 in group D (p less than 0.05). From these results, it is concluded that the transitional zone for the reversal of mitochondria function and energy metabolism following prolonged liver ischemia appears at around 60 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine Nucleotides↗
PubMed1988

Central venous pressure and plasma Na concentration during drinking behavior in the dehydrated dog.

Changes in circulating blood volume, plasma Na concentration, and central venous pressure (CVP) after fluid intake were monitored continuously in water-deprived dogs. When dogs were allowed free access to fluid (tap water or 0.9% saline), rapid satiation appeared before any systemic changes in blood composition took place, and CVP increased remarkably (about 6 mmHg) in association with drinking behavior. The possible roles of CVP as a controlling factor of drinking were hypothesized.

Animals↗
PubMed1988

[Nd:YAG laser treatment of recurrent adenomas in the preserved rectum in patients with a ileo-rectal anastomosis in familial polyposis coli].

Eight patients with ileo-rectal anastomosis following a total colectomy for familial polyposis coli underwent Nd: YAG laser therapy to treat recurrent adenomas in the preserved rectum after the operation. The median follow-up period for these eight patients has been 4 years and 7 months. Of the eight patients, one underwent a mucosectomy of the preserved rectum and an ileo-anal pull-through five years after the first operation because of recurrent diffuse polyposis of the preserved rectum. In the remaining seven patients, Nd:YAG laser therapy was found to be effective in the abration of recurrent polyps.

Adenoma↗
PubMed1988

[In vivo measurements of electrical bio-impedance of breast tumors].

The electrical bio-impedance of 17 breast tumors including 12 breast cancers and 5 fibroadenomas, were measured in vivo with three-electrode method in the frequency range of 0 to 200 KHZ. The three-electrode consists of a coaxial needle electrode inserted into the tumor and a large reference electrode on upper abdominal wall. The tissue can be regarded electrically as a equivalent consisted of extracellular resistance (R1), intracellular resistance (R2), and electric capacitance of the cell membrane (C). These three parameters were calculated from the measured values of electrical bioimpedance. It was found that R1, and R2 of breast cancers were significantly higher than those of fibroadenomas (p less than 0.001), and that C of breast cancers was significantly lower than that of fibroadenomas (p less than 0.001). The measurement of the electrical impedance of breast tumor in vivo may be useful for the differential diagnosis of breast lesions.

Adenocarcinoma, Scirrhous↗
PubMed1988

[Postirradiation malignant fibrous histiocytoma following mastectomy in breast cancer].

A case is reported of a patient who developed a histological unusual sarcoma in the chest wall 5.3 years after postoperative radiation therapy (5,000 rads) for breast cancer. This sarcoma showed microscopic features of malignant fibrous histiocytoma (MFH). A review of the literature disclosed 16 other cases in which MFH developed under similar circumstances. An analysis of these 16 cases and the case reported here showed that the mean radiation dose was 5,623 rads, that the time period between irradiation and the development of MFH ranged from 2 to 27 years and that wide resection offered better prognosis than chemotherapy.

Breast Neoplasms↗
PubMed1988

[Clinical trial of 5'-DFUR in patients with recurrent breast cancer].

5'-DFUR was administered orally to recurrent breast cancer patients at a daily dosage of 1,200 mg given 3 times a day for more than 8 weeks. Out of 16 evaluable cases, 1 CR, 5 PR, 5 NC and 5 PD were observed, and the overall response rate was 37.5%. There was no significant difference in the response rate between the patient with or without prior fluorinated pyrimidine therapy, or between sites of the lesion. Toxic effects consisted of gastrointestinal toxicity such as diarrhea (25%), anorexia (12.5%), abdominal pain (12.5%) and nausea and vomiting (6.3%). No other severe side effect was observed. These results suggest that 5'-DFUR can be useful for the treatment of breast cancer.

Administration, Oral↗
PubMed1988

[A case of cystadenocarcinoma of the liver complicated by gastric cancer--a review of 83 cases of primary cystic liver cancer in the literature].

So far as is known, this is the first reported case in the literature of a primary cystic liver cancer complicated with a gastric cancer. A 77-year-old female was admitted to hospital because of a swelling in the upper abdomen and appetite loss. CT scanning, an echogram, and an angiogram of the abdomen revealed a large cystic lesion which originated from the left lobe of the liver. A DIC indicated a gall stone, Further, upper GI fluoroscopy and endoscopy revealed a gastric cancer of the Borrmann II type, and thus a dome resection of the cyst, cholecystectomy, aad 3/4 partial gastrectomy was performed. The liver was found to contain much mucin. The histology indicated a cystadenocarcinoma of the liver, and an adenocarcinoma of the stomach of a poorly differentiated type.

Aged↗
PubMed1988

Deleterious effects of splanchnic congestion on hepatic energy metabolism following repeated portal triad cross-clamping in dogs.

Thirty minutes of warm hepatic ischemia produced by portal triad cross-clamping was repeated five times at 30-minute intervals in three groups of five dogs each: Group A was subjected only to portal triad cross-clamping; Group B received simultaneous clamping of the celiac axis and the superior mesenteric artery; and Group C had a simultaneous splenojugular shunt. The arterial blood ketone body ratio (acetoacetate/beta-hydroxybutyrate: KBR), reflecting the NAD+/NADH ratio in liver mitochondria, decreased significantly after each cross-clamping in all groups. After the first declamping, there was no significant difference in the recovery rate of the KBR among the three groups. After the second declamping, the recovery rate in Group A decreased significantly compared with the rates of Groups B and C (P less than 0.05). After the fourth declamping, the recovery rate in Group B was significantly lower than that of Group C (P less than 0.05). The hepatic energy charge [(ATP + 1/2ADP)/(ATP + ADP + AMP)] 30 minutes after the fifth declamping decreased significantly to 0.75 +/- 0.01 in Group A, compared with 0.84 +/- 0.01 in Group C (P less than 0.01). The lactate and total free plasma amino acid levels in the arterial blood increased significantly in the order of Groups A, B, and C. It is suggested that the inflow of stagnant portal venous blood to ischemic liver impairs hepatic energy metabolism.

Amino Acids↗
PubMed1988

Influence of hemorrhagic shock on hepatic energy metabolism in carbon tetrachloride-induced cirrhotic rats.

The influence of hemorrhagic shock on hepatic energy metabolism was investigated in carbon tetrachloride (CCl4)-induced cirrhotic rat. In normal and CCl4-treated rats, the hepatic mitochondrial redox state and phosphorylative activity decreased significantly (P less than 0.001) following hemorrhagic shock, with mean arterial blood pressure at 30 mmHg. In normal rats, they were immediately restored upon reinfusion of shed blood after 2 hr of hemorrhagic shock, followed by marked enhancement 120 min later. By contrast, in cirrhotic rats redox state and phosphorylative activity in hepatic mitochondria did not recover immediately, and there was neither elevation of redox state nor enhancement of phosphorylative activity in hepatic mitochondria. The survival rate at 24 hr was 10% in contrast to 90% in normal rats. These results suggest that the absence of early recovery followed by enhancement of mitochondrial function in the cirrhotic liver is fundamentally related to the mechanism of hepatic failure following hemorrhagic shock.

Adenine Nucleotides↗