Biomedical subjects

T Morimoto

Publications and source records attributed to T Morimoto.

At least 451 records · Page 25Linked to original sources

PubMed1992

Bone metastases of hepatocellular carcinoma after liver resection.

Between January 1985 and July 1990, 323 cases of hepatocellular carcinoma underwent liver resection in our department. Bone metastases were found in 12 of these cases (3.7%). Bone metastases were mainly found in vertebral bone (58.3%) and pelvic bone (41.7%). The time interval to the development of bone metastasis after liver resection was closely related to the presence of intrahepatic metastasis and the stage at operation. In all cases, the initial clinical symptom was pain and/or motor disturbance. Radiotherapy was performed in 10 cases and transcatheter arterial embolization or surgery was performed in 4 cases. The pain or neurological symptoms improved with these therapies in all cases. Cumulative survival was 1 year in 74%, 2 years in 34%, and 3 years in 17%, respectively.

Adult↗

PubMed1992

Estimated weight of the residual parathyroid gland after parathyroidectomy using plasma levels of the parathyroid hormone.

The possibility of estimating the total weight of the parathyroid glands based on the plasma concentration of the parathyroid hormone (PTH) would be of great help when searching for the parathyroid glands during surgery on patients with secondary hyperparathyroidism. Thus, we studied the relationship between the levels of carboxyl-terminal PTH (C-PTH), midportion PTH (M-PTH) and intact PTH, and the weight of the parathyroid glands resected for secondary hyperparathyroidism. The subjects studied were 11 patients with secondary hyperparathyroidism caused by chronic renal failure. The pre- and post-operative differences in the plasma C-PTH levels and plasma M-PTH levels were significantly correlated with the weight of the resected parathyroid glands (p less than 0.001 for both), but there was no correlation between the differences in the levels of intact PTH and the weight of the resected parathyroid glands. From these relationships we estimated the weight of the residual parathyroid gland after parathyroidectomy using the levels of each PTH. All patients in whom the residual parathyroid gland was estimated to be heavy based on the levels of M-PTH showed recurrence of hyperparathyroidism after the parathyroidectomy. We therefore found that estimation of the weight of the parathyroid glands from the levels of M-PTH is both possible and useful.

Adult↗

PubMed1992

A rare case of fibroadenoma in a tubular adenoma of the breast.

We report herein a case of a 31 year old housewife who underwent an excisional biopsy for a well-circumscribed lump in her breast. The lump contained 2 histological patterns, namely, fibroadenoma and tubular adenoma. These patterns had no transitional zone, were distinct and changed abruptly. This case was histologically diagnosed as "a fibroadenoma in tubular adenoma of the breast, benign", with no other such case ever having been reported in Japan. The histological findings of this case, convinced us that tubular adenoma is closely related to fibroadenoma.

Adenofibroma↗

PubMed1992

Clinical application of arterialization of portal vein in living related donor partial liver transplantation.

Arterialization of the portal vein was employed during hepatic arterial reconstruction in our first few clinical experiences of partial liver transplantation using liver grafts obtained from living related donors. This procedure reduced the time required for revascularization of the grafts to about 25 min, and could in fact reduce the ischemic phase of the grafts. Repeated practice of the clinical transplantation technique has shortened the time needed to complete vascular reconstruction, eliminating the need for this procedure in most of our subsequent cases. In many clinical cases, however, there may be emergency situations which require vascular reconstruction, resulting in a prolongation of ischemic phase and the deterioration of the cellular viability of the graft. In such situations, arterialization of the portal vein can be a useful way to prevent the prolongation of the ischemic phase and to rescue the graft.

Arteriovenous Shunt, Surgical↗

PubMed1992

Astrocytoma with widespread calcification along axonal fibres.

We describe a 44-year-old man found to have a diffusely calcified astrocytoma originating in the left frontoparietal region and extending along the axonal fibres into the opposite cerebral hemisphere and brain stem. Computed tomography and magnetic resonance imaging clearly demonstrated the spread of the tumour. The tumour was partially resected and histologically diagnosed as an astrocytoma. A correct preoperative diagnosis was difficult, because the lesion was very slow-growing and its widespread calcification mimicked congenital or inflammatory calcium deposits.

Adult↗

PubMed1992

Isoflurane in the management of status epilepticus after surgery for lesion around the motor area.

When conventional treatment for status epilepticus fails, general anaesthesia is recommended. We present our experience with isoflurane, an inhalational anaesthetic, in the management of four patients with status epilepticus which occurred soon after surgery for motor area lesion. The seizures were controlled with relatively small concentrations of isoflurane. Hypotension, the only adverse effect of isoflurane, was managed easily with the use of dopamine in physiological saline. Although status epilepticus occurring soon after surgery is transient, it carries a risk of persistent brain damage if active treatment is not instituted promptly. Isoflurane general anaesthesia may be recommended to control it in the intensive neurosurgical care.

Adult↗

PubMed1992

MRI in poliomyelitis-like syndrome.

We report the MRI findings in a patient with poliomyelitis-like syndrome. MRI demonstrated a lesion extending from the dorsal region of the pons to the upper level of the thoracic spinal cord. The spinal cord was particularly affected in a region involving the bilateral anterior horns. Although its pathology is unknown, the lesion of the spinal cord seemingly reflects the pathological features of this disease.

Humans↗

PubMed1992

Absence of mitochondrial enhancement in the remnant liver after partial hepatectomy in cirrhotic rats.

Changes in energy metabolism after 70% partial hepatectomy were investigated in normal and carbon-tetrachloride-(CCl4)-induced-cirrhotic rats by evaluating hepatic mitochondrial ATP synthesizing activity as well as liver tissue levels of adenine nucleotides and lipid peroxide. Preoperative concentrations of ATP and total adenine nucleotides (TAN: ATP + ADP + AMP) in mumol/g dry weight (dw) and the energy charge potential (ECP) in the cirrhotic livers were 8.53 SEM 0.25, 14.73 SEM 0.54, and 0.74 SEM 0.01, respectively, and were significantly lower than those of normal livers (12.04 SEM 0.34, 15.75 SEM 0.12, and 0.86 SEM 0.01, P less than 0.01 in TAN). There was no difference in the preoperative mitochondrial phosphorylation rate (PR = x 10(-10) mol ATP/sec per mg mitochondrial protein) between normal and cirrhotic livers (21.01 SEM 0.95 and 21.55 SEM 1.03, respectively). After hepatectomy, in the normal livers these values decreased slightly after 12 h, remained low until 48 h, and returned to the preoperative value at 72 h. PR was remarkably enhanced and reached the maximum level of 32.54 SEM 2.07 at 24 h (P less than 0.001, compared to the sham-operated rats) and gradually returned to the preoperative value at 72 h. In the cirrhotic livers, ATP and ECP levels were drastically decreased at 12 h and recovered to the preoperative levels within 24 h, while TAN level remained unchanged. Enhancement of PR was not observed in any of the cirrhotic livers during the experiment. Lipid peroxidation was transiently increased postoperatively with no difference between normal and cirrhotic livers both in the sham-operated and the hepatectomized rats. These findings suggest that the energy status was more depressed in the cirrhotic livers than in normal livers both before and after hepatectomy. This depressed energy status might be attributed to the low preoperative tissue levels of adenine nucleotides and ECP level in the cirrhotic livers as well as to the absence of the enhancement of PR in the remnant livers.

Adenine Nucleotides↗

PubMed1992

Conversion of mitochondrial redox state toward oxidation by prostacyclin in 70%-hepatectomized rats.

Arterial blood ketone body ratio (KBR) and hepatic mitochondrial phosphorylation rate (PR) were investigated in partially (70%) hepatectomized rats treated with 100 micrograms/kg body weight prostacyclin (PGI2) analogue i.p. after operation and every 12 h thereafter up to 72 h. Sampling was performed at 12, 24, 48, and 72 h after operation. In sham-operated rats, KBR significantly increased from the preoperative values of 0.34 +/- 0.03 and 0.38 +/- 0.03, to 0.55 +/- 0.03 and 0.58 +/- 0.02 at 12 h in the groups with and without PGI2 treatment, respectively (P less than 0.001). KBR returned to the preoperative levels after 24 h in the PGI2-treated group, while it tended to be in the lower normal range in the untreated group. In the hepatectomized rats, KBR significantly decreased in the untreated group compared with the preoperative values and the values in the sham-operated group. It returned to the preoperative range within 72 h. In the PGI2-treated group, KBR increased significantly, to values above 0.54, after a 24-h delay and was maintained at those levels for 72 h. Concentrations of total ketone bodies (TKB) in the untreated groups remained in the upper range of preoperative values (above 200 nmol/ml) in the sham-operated rats and decreased significantly in the hepatectomized group (234 to 126 nmol/ml). TKB in the treated groups tended to decrease only in the sham-operated group (205 to 166 nmol/ml), and was massively reduced in the hepatectomized group (167 to 81 nmol/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

3-Hydroxybutyric Acid↗

PubMed1992

Preserved mitochondrial function by allopurinol despite deteriorated hemodynamics in warm ischemia-damaged canine liver.

To investigate the pathophysiology of warm ischemia (WI) of the liver, the changes in hemodynamics and energy metabolism were studied during and after 60-min complete WI induced by total hepatic vascular exclusion (HVE) in the canine model. Hepatic arterial blood flow after WI was maintained at 76% of the pre-ischemic level, while portal blood flow was only 27% of the pre-ischemic level associated with increased portal vein pressure, which was twice the pre-ischemic level, resulting in a decrease of total hepatic blood flow to 46% of the pre-ischemic level. Concentration of tissue lipid peroxide increased after WI. Arterial blood ketone body ratio (AKBR), which reflects the hepatic mitochondrial redox state, could not recover to the pre-ischemic level after termination of WI. However, when 100 mg/kg of allopurinol (xanthine oxidase inhibitor) was administered intravenously 10 min prior to initiating WI, AKBR was restored to the pre-ischemic level at 30 min after WI in spite of the fact that allopurinol administration to one group produced no remarkable changes in the hepatic hemodynamics compared with the group without allopurinol treatment. Concentration of adenine nucleotides was significantly higher for the treated group at the end of and after WI than for the group without allopurinol treatment and was maintained at a higher level even after WI. Lipid peroxide production was suppressed. Electron microscopic examination revealed that allopurinol treatment could not prevent mitochondrial swelling. It is suggested that WI causes injury primarily to the portal sinusoidal circulation, resulting in portal congestion concomitant with high portal pressure after the release of WI. Allopurinol could prevent the deterioration of mitochondrial ATP metabolism, and was able to inhibit lipid peroxide production, resulting in the rapid recovery of mitochondrial redox state in spite of the fact that it produced no amelioration of hepatic hemodynamics and morphological alterations.

Adenosine Triphosphate↗

PubMed1992

Changes in Na concentration in cerebrospinal fluid during acute hypernatremia and their effect on drinking in juvenile rats.

To clarify if there are age-related differences in osmoreception, we measured changes in Na concentration in cerebrospinal fluid ([Na]csf) during and after acute hypernatremia in juvenile (JR) and adult rats (AR). The Na concentrations in plasma ([Na]pl) and [Na]csf were measured during intravenous infusion of 1 M NaCl solution (INF, 0.2 ml/100 g body wt. for 10 min) and for 20 min thereafter in anesthetized rats. To measure [Na]pl, a flow-through Na-sensitive electrode was placed in an extracorporeal shunt from a carotid artery to a jugular vein, and to measure [Na]csf, a Na-sensitive electrode was placed in the right lateral ventricle. There was a linear relationship between delta[Na]pl and delta[Na]csf during INF. The slope of delta[Na]pl vs. delta[Na]csf was 0.42 +/- 0.03 (n = 7) in JR, which was significantly higher (p less than 0.01) than in AR (0.23 +/- 0.04, n = 6). We also measured water intake during and after INF of the same amount of 1 M NaCl solution in conscious JR (n = 6) and AR (n = 6). The JR drank 1.93 +/- 0.22 ml/100 g body wt. of water within 30 min of the start of INF, which was significantly more (p less than 0.05) than AR drank (1.20 +/- 0.13 ml/100 g body wt.). These results indicate that the movement of Na or water, or both, between the blood and cerebrospinal fluid in acute hypernatremia is greater in JR, and that the osmoreceptors in JR are more sensitive than those in AR.

Animals↗

PubMed1992

Generation of lysoglyceroglycolipids in the cyanobacterium, Phormidium tenue.

Two kinds of lysoglycolipids, monogalactosyl 1-monoacylglycerol and digalactosyl 1-monoacylglycerol were generated in the cyanobacterium, Phormidium tenue, when it was stored at -20 degrees for more than 1 month. By comparison of the compositions of fatty acid residues between monogalactosyl 1-monoacylglycerol and monogalactosyl diacylglycerol, digalactosyl 1-monoacylglycerol and digalactosyl diacylglycerol, respectively, the 1-monoacylgalactolipids were presumed to be formed by regioselective deacylation at the sn-1 position with subsequent acyl-group migration from the sn-2 to the sn-1 position. In contrast, 1-monoacyl derivatives of sulphoquinovosyl diacylglycerol and phosphatidylglycerol, the other membrane lipids contained in cyanobacteria, were not formed.

Carbohydrate Sequence↗

PubMed1992

Secretory meningioma with elevated serum carcinoembryonic antigen level.

We recently encountered a 68-year-old woman with right sphenoid wing meningioma of the secretory type accompanied by an elevated serum carcinoembryonic antigen level. This case was neuroradiologically characterized by marked brain edema. Histologically, the lesion was rated as having meningothelial components and was rich in blood vessels and pseudopsammoma bodies. Carcinoembryonic antigen, epithelial membrane antigen, keratin, and cytokeratin were immunohistochemically detected in the pseudopsammoma bodies and the cells producing these bodies.

Aged↗

PubMed1992

Properties of rhythmically active reticular neurons around the trigeminal motor nucleus during fictive mastication in the rat.

Response properties of the neurons in the reticular formation around the trigeminal motor nucleus (MoV) were examined during cortically-induced fictive mastication (CIFM) in anesthetized and immobilized rats. Forty-three neurons were rhythmically active (RA neurons) during CIFM, most of which were located in the supratrigeminal nucleus and the reticular formation medial to the oral spinal trigeminal nucleus. The firing frequency of 36 of the RA neurons was modulated in the same rhythm as that of masseteric or digastric nerve activities during CIFM. We divided these neurons into four groups according to the phase of activation: sixteen neurons fired mainly in the phase of masseteric activity (type 1), 11 fired in the transition phase from masseteric activity to digastric activity (type 2), 5 fired in the phase of digastric activity (type 3) and 4 fired in the transition phase from digastric activity to masseteric activity (type 4). Thirty-nine (91%) of the 43 RA neurons responded to at least one of the tested peripheral stimuli. The responses were mostly excitatory but inhibitory responses were sometimes obtained, especially for types-1 and 2 neurons. RA neurons in the reticular formation medial to the oral spinal trigeminal nucleus responded to stimulation of inferior alveolar nerve at a shorter latency than RA neurons in the supratrigeminal nucleus. Fifteen (48%) of 31 RA neurons responded to triple-pulse stimulation of the contralateral cortex. In contrast, only 5(26%) of the 19 RA neurons responded to the ipsilateral cortical stimulation. Stimulation of the ipsilateral MoV was performed on 24 RA neurons, of which 9 responded antidromically (A-RA neurons) at latencies of 0.4-1.4 ms. Eight (89%) of the 9 A-RA neurons received peripheral inputs. The spike triggered averaging method was applied to 4 of the 9 A-RA neurons, ad in all cases short latency field potentials were recorded in the MoV. We conclude that trigeminal premotor neurons receive convergence from central and peripheral inputs. This integration can adjust the appropriate level of motoneuronal excitability during mastication.

Animals↗

PubMed1992

Endothelium-dependent vasodilation by LP-805, a novel vasodilating agent, on rat thoracic aorta.

1. In rat aortae with [E(+)-tissue] and without [E(-)-tissue] intact endothelium, LP-805 relaxed the preparations precontracted with 35.9 mM K+ and its action in E(+)-tissues was more potent than that in E(-)-tissues. Moreover, the inhibitory action of glibenclamide in E(-)-tissues was more potent than that in E(+)-tissues. 2. The relaxing action of LP-805 on E(+)-tissues treated with NG-nitro-L-arginine methyl ester (10 microM), a potent inhibitor of nitric oxide synthesis, was the same as that in E(-)-tissues. 3. Methylene blue (10 microM) also inhibited the LP-805 induced relaxation in E(+)-tissues. 4. Indomethacin (10 microM) had no effect on LP-805-induced relaxation in E(+)-tissues. 5. These results suggest that the vasorelaxant action of LP-805 involves the mechanism which causes the release of nitric oxide (NO) from vascular endothelium.

Animals↗

PubMed1992

Effects of LP-805, a novel vasorelaxant agent, a potassium channel opener, on rat thoracic aorta.

1. In rat thoracic aorta, LP-805 (0.1-10 microM) caused the marked reduction of NE-induced maximum response and relaxed the low K+ (less than 35.9 mM)-induced contraction, in a concentration-dependent manner, but failed to relax the high K+ (65.9 mM)-induced contraction. 2. Glibenclamide (0.3-1 microM) caused a parallel shift of concentration-response curve produced by LP-805 for 25.9 mM K(+)-induced contraction and prevented the LP-805-induced reduction in maximum response evoked by NE in a concentration-dependent manner. 3. Glibenclamide (10 microM) prevented the LP-805 (10 microM)-induced decrease in cytosolic Ca2+ levels which was increased by 1 microM NE or 25.9 mM K+. 4. LP-805 (10 microM) increased basal 86Rb efflux, which was completely inhibited by 10 microM glibenclamide. 5. The results suggest that LP-805 causes a vasorelaxation as a consequence of the decrease in cytosolic Ca2+ levels due to the increase in K+ efflux via opening ATP-dependent K+ channels.

Animals↗

PubMed1992

Effects of LP-805, a new vasodilating agent, on cytosolic Ca2+ and contraction in vascular smooth muscle of rat aorta.

1. LP-805 (0.1-10 microM) caused the reduction in norepinephrine (NE)-and serotonin (5-HT)-induced maximum response, a parallel shift of the concentration-response curve for prostaglandin F2 alpha (PGF2 alpha), in a concentration-dependent manner, but not K(+)-induced maximum response. 2. In Ca(2+)-free solution, LP-805 (0.1-10 microM) markedly inhibited the phasic contraction induced by 0.3 microM NE and the contraction induced by Ca2+ (0.1-2 mM) in the presence of 0.3 microM NE, in a concentration-dependent manner. Similar results were obtained in the presence of 5-HT (10 microM) or PGF2 alpha (10 microM). 3. In fura-2 loaded strips, ryanodine (10 microM) and LP-805 (10 microM) abolished 1 microM NE- and 30 microM 5-HT-induced phasic contractions, and inhibited the increase in cytosolic Ca2+ levels by both the agonists in the absence of external Ca2+, but had no influence on the following sustained contractions. 4. The effects of LP-805 on PGF2 alpha-induced Ca2+ transient and large sustained contraction were similar to those of ryanodine. 5. These results suggest that a vasodilatory effect of LP-805 might account for inhibiting the mobilization of external Ca2+ through receptor mediated passway and the Ca2+ release from a ryanodine sensitive Ca2+ store.

Animals↗

PubMed1992

Effects of LP-805, a new vasodilating agent, on rat thoracic aorta.

1. In canine coronary arteries, the contraction induced by prostaglandin F2 alpha (PGF2 alpha), but not by 65.9 mM K+, were relaxed by LP-805 (0.01-10 microM) in a concentration-dependent manner. 2. In rat thoracic aorta, LP-805 (0.1-10 microM) also relaxed the preparations contracted with norepinephrine (NE) and PGF2 alpha, but did not relax the contraction produced by 65.9 mM K+. 3. LP-805 (3-10 microM) inhibited the increase in cytosolic Ca2+ levels and contractions evoked by NE (1 microM) in the absence or presence of external Ca2+ in rat thoracic aorta. 4. LP-805 (0.1-10 microM) inhibited synthesis of IP3 induced by NE (0.3 microM) and cyclic AMP phosphodiesterase activity, and increased intracellular cyclic AMP levels in rat thoracic aorta. 5. These results suggest that a vasodilatory effect of LP-805 is due to inhibiting the increase in cytosolic Ca2+ levels via stimulation of various receptors, modulating second messenger synthesis.

Adenylyl Cyclases↗