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Biomedical subjects

A Harada

Publications and source records attributed to A Harada.

At least 253 records · Page 14Linked to original sources
PubMed1991

Effects of thromboxane A2 synthetase inhibitor on postischemic liver injury in rats.

This study was designed to clarify the mechanism of a reversal of the ischemia-induced decrease in adenosine triphosphate (ATP) in relation to the changes in liver blood flow. All vessels to the left and median lobes were occluded for 15 or 30 min and then reperfused for 15 or 30 min, respectively. Ischemia led to a significant decrease in the ATP level. ATP levels recovered fully after 30 min of reperfusion following 15 min of occlusion. However, a significantly low ATP level was observed even after 30 min of reperfusion following 30 min of occlusion. Premedication with CV-4151 (5 mg/kg, i.v.), a thromboxane A2 (TXA2) synthetase inhibitor, significantly improved the recovery of ATP levels after 30 min of reperfusion following 30 min of occlusion. Liver blood flow was restored fully immediately after reperfusion following 15 min of occlusion. In contrast a significantly low liver blood flow was observed after 30 min of reperfusion following 30 min of occlusion. Premedication with CV-4151 accelerated the recovery of liver blood flow after reperfusion. Morphological studies revealed that microthrombi were formed during ischemia, and CV-4151 mitigated the formation of microthrombi. These results indicate that the formation of microthrombi, which might be associated with TXA2 synthesis during ischemia, inhibited the restoration of liver blood flow, which might be responsible for the obstruction of the recovery of ATP.

Adenosine Triphosphate↗
PubMed1991

Effects of prostaglandin E1 on the recovery of ischemia-induced liver mitochondrial dysfunction in rats with cirrhosis.

Interruption of hepatic blood supply for 60 min deteriorated liver mitochondrial respiratory functional indices--that is, respiratory control index (RCI) and the rate of oxygen consumption in state-III respiration (ST III O2). Recovery of ischemia-induced decreases in these functional indices in a saline-administered cirrhotic liver group was retarded compared with that in a normal liver group, and significantly low RCI and ST III O2 persisted 15 min after reperfusion. Prostaglandin E1 (PGE1) did not improve ischemia-induced decreases in RCI and ST III O2 but accelerated the recovery of mitochondrial respiratory function after reperfusion. Adenosine triphosphate (ATP) levels were markedly decreased during ischemia, and retardation of ATP recovery was also observed in rats with cirrhosis. PGE1 improved the recovery of ATP level in rats with cirrhosis. Liver blood flow in the cirrhotic liver was significantly lower than that of the normal liver. PGE1 enhanced liver blood flow. These results indicate that retardation of the recovery of RCI and ST III O2 in the cirrhotic liver might be based on the decrease in tissue blood flow and that agents increasing tissue blood flow might contribute to the acceleration of the recovery of mitochondrial respiratory function.

Adenine Nucleotides↗
PubMed1991

[The significance of extent of resection in the treatment of hepatoma].

The relationship between the types of hepatectomy in each stage of hepatoma and the outcome was examined in 222 patients with hepatoma, according to the rules established by Liver Cancer Study Group of Japan. In Stage 1, the survival rate after absolute curative resection was better than that after relative curative resection. In Stage II, the survival after segmentectomy or lobectomy was significantly better than that after subsegmentectomy or less. Tumor recurrence rates in the remaining liver after segmentectomy or lobectomy were significantly lower than that after smaller resections. In Stages III and IV, there was no difference in survival among the various extents of hepatectomy. Incidence and cause of death after hepatectomy were not influenced by the extent of hepatectomy, as far as it was not beyond the preoperatively estimated safety limits. These results indicate the following: 1) In Stage I, absolute curative resection must be carried out. (2) In Stage II, segmentectomy or lobectomy should be applied when feasible. (3) The patients treated with subsegmentectomy or less for Stage II tumor, and the patients with Stage III or Stage IV tumor are at high risk of recurrence, and those patients need adjuvant therapy after hepatectomy.

Adult↗
PubMed1991

Clinical evaluation of plasma abnormal prothrombin (des-gamma-carboxy prothrombin) in hepatobiliary malignancies and other diseases.

Des-gamma-carboxy prothrombin (DCP), a protein induced by vitamin K absence or antagonist-II (PIVKA-II) was measured in the plasma of patients with primary hepatocellular carcinoma and those with various other hepatobiliary and pancreatic diseases. DCP levels were determined by enzyme immunoassay (E-1023), using an anti-DCP monoclonal antibody. Forty-two of the 91 patients (46.2%) with hepatocellular carcinoma had abnormally elevated levels of DCP, whereas only one of the 24 patients with hepatic cirrhosis showed a slight increase. An increase was also observed in some patients with obstructive jaundice. There was no correlation between plasma levels of DCP and those of serum alpha-fetoprotein (AFP). In most patients with hepatocellular carcinoma, plasma DCP levels normalized after curative surgical resection. Plasma DCP levels were not related to the plasma concentration of vitamin K in the patients with hepatocellular carcinoma. Plasma DCP determination may be useful in the diagnosis and postoperative monitoring of the response of hepatocellular carcinoma.

Biliary Tract Diseases↗
PubMed1991

An autopsy case of a traffic accident accompanied with fibrodysplasia ossificans progressiva: a case report.

A report is made on an autopsy case of a 19-year-old man with fibrodysplasia ossificans progressiva, who died in a traffic accident. The cause of death was acute massive haemorrhage from the lacerated liver. There was a bar of paraspinal ossifying lumps, which was hard, ramified throughout his back and restricted the movement of the thoracic vertebral column. Numerous hard swellings were palpable through the skin on the elbows, thighs, and lumbar and gluteal regions. Small bony masses were found in the muscles. According to his clinical records, radiographs and autopsy findings, he might suffer from the later stage of the disease. As a cause of the accident, though suicidal attempt by using the car or dosing was suspected, the influence of the disease itself was also considered. In connection with this case, it seemed that in the traffic death case with a rare disease, the careful investigation of the clinical symptoms and severity of the disease is very important.

Accidents, Traffic↗
PubMed1991

Serum concentration and immunohistochemical localization of SPan-1 antigen in pancreatic cancer. A comparison with CA19-9 antigen.

We studied SPan-1 antigen in 64 patients with pancreatic cancer by measuring serum concentrations with RIABEAD and examining the intratumor staining patterns immunohistochemically. Serum concentrations were elevated (greater than 30 U/ml) in 46 patients (72.0%), roughly the same percentage as with elevated serum CA19-9 concentrations. Ten out of 19 patients without CA19-9 antigen expressed SPan-1, and the combined rate of positivity was 86% (55/64). Immunohistochemically, CA19-9 was localized to the apical surface and the supranuclear cytoplasm of normal epithelial cells, but SPan-1 was localized to the supranuclear cytoplasm or throughout the cytoplasm. After malignant degeneration, both antigens were found over the entire plasma membrane, throughout the cytoplasm (loss of polar distribution) and in the stroma surrounding the cells. SPan-1 was detected in 48 out of 54 adeno-carcinomas of the pancreas (89%), and all cases with an elevated serum concentration displayed stromal staining in the cancer tissues. The utility of SPan-1 antigen as a tumor marker for diagnosing pancreatic cancer was found to be equal to that of CA19-9.

Adenocarcinoma↗
PubMed1991

[Permanent cardiac pacing in patients on chronic dialysis].

Four patients on chronic dialysis, who underwent permanent pacemaker implantation, were reviewed. The indication for pacing was sick sinus syndrome in three patients and complete atrioventricular block in one. Physiological pacing modes were chosen in all patients (DDD in three and AAI in one). Sensing and pacing properties in these patients studied at implantation and at follow-up (22-41 months after implantation) were similar as those in non-dialysis patients. However, the study of these properties during hemodialysis showed a significant elevation of atrial pacing threshold associated with marked decrease of serum potassium concentration in two patients. We conclude that dialysis patients with significant bradyarrhythmia should be considered for pacemaker implantation in the same manner as non-dialysis patients. However, special attention should be payed on the elevation of pacing threshold during hemodialysis.

Aged↗
PubMed1991

The effect of bovine brain gangliosides on essential tremor.

We reported the case of a 74-year-old woman suffering from essential tremor for 20 years which was treated effectively with purified bovine brain gangliosides containing GM1, GD1a, GD1b and GT1b gangliosides. The trials of the treatment were conducted twice, 40 mg and 20 mg gangliosides per day respectively administered intramuscularly. Essential tremor dramatically improved with gangliosides on the second day of treatment, suggesting that the effect of gangliosides was not induced by neuronal sprouting or regeneration. It is speculated that a certain type of essential tremor is a reversible disease of membrane disorder.

Aged↗
PubMed1991

Effect of hyperdynamic circulatory support on hepatic hemodynamics, oxygen supply and demand after massive hepatectomy.

This study was designed to clarify the effect of hyperdynamic circulatory support with dobutamine or dopamine after massive hepatectomy on hepatic hemodynamics, oxygen supply and demand, and lactate uptake. Mongrel dogs were allocated three groups: 70% hepatectomy group; a group that received dobutamine after 70% hepatectomy; and a group that received dopamine after 70% hepatectomy. Hepatic blood flow and oxygen delivery to the liver decreased after 70% hepatectomy. Although oxygen consumption in the liver also decreased, oxygen consumption per liver weight increased after massive hepatectomy; an increase of oxygen uptake ratio and a decrease of lactate uptake in the liver were observed. When dobutamine or dopamine were administered after 70% hepatectomy, hepatic blood flow increased, followed by normalization of the balance of oxygen supply and demand in the liver; lactate uptake subsequently improved in the liver. The data support the conclusion that hepatic oxygen consumption affected by dopamine and dobutamine is associated with an increase in the extraction of lactate. Hyperdynamic hepatic circulatory support was advantageous to hemodynamics and metabolism in the residual liver after massive hepatectomy.

Animals↗
PubMed1990

A T-to-A substitution in the E1 alpha subunit gene of the branched-chain alpha-ketoacid dehydrogenase complex in two cell lines derived from Menonite maple syrup urine disease patients.

We cloned and sequenced cDNAs of the E1 alpha and E1 beta subunits of the branched chain alpha-ketoacid dehydrogenase complex (BCKDH) in two cell lines derived from two different Menonite MSUD patients (GM 1655, GM 1099). A T-to-A substitution which generates an asparagine in place of a tyrosine at amino acid 394 of the mature E1 alpha subunit was present in both alleles in these two cell lines, whereas cDNAs of the E1 beta subunit in these cell lines were identical to that of normal human lymphoid cell line and that of the clone from a human placenta cDNA library. It is suggested that the Menonite MSUD is caused by the missense mutation of the E1 alpha subunit of the BCKDH complex.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗
PubMed1990

Use of bovine lung heparin to obviate anaphylactic shock caused by porcine gut heparin.

Intracardiac repair in a 7-year-old girl with tetralogy of Fallot was hampered because of an anaphylactic reaction with cardiopulmonary collapse caused by porcine gut heparin. This patient had an extremely rare case of hypersensitivity to porcine gut heparin but not to bovine lung heparin. Uneventful radical operation could be performed with the use of bovine lung heparin for systemic heparinization during cardiopulmonary bypass.

Anaphylaxis↗
PubMed1990

Computerized potential distribution mapping: a new intraoperative mapping technique for ventricular tachycardia surgery.

This study evaluated potential distribution mapping as a method for localizing the site of origin of ventricular tachycardia (VT). In contrast to conventional activation time maps, potential distribution maps require less editing and thus can be more automated and rapidly processed for interpretation of multiple beats of VT. As a series of potential distribution maps during VT is required for detailed analysis, an on-line computerized system was designed to display potential distribution maps sequentially at 1-ms intervals as a color movie. Potential distribution maps and activation time maps were constructed from 182 epicardial and endocardial unipolar electrodes during 12 episodes of reproducible monomorphic VT in 9 dogs four to six days after experimental myocardial infarction (mean cycle length, 162 +/- 21 ms). At the onset of each depolarization during VT, a potential minimum abruptly developed on the surviving epicardium and another on the surviving endocardium of the left ventricle, both immediately adjacent to the subendocardial infarct. These two minima on the initial potential distribution maps corresponded to the sites of earliest epicardial and endocardial activation breakthrough recorded on the activation time maps. These two minima subsequently expanded or moved into the adjacent area and coincided with the spread of activation fronts on the epicardial and endocardial surfaces. Thus, the rapid display of sequential, computerized potential distribution maps of multiple beats of VT provides a dynamic means of identifying the site of origin of VT, and therefore should facilitate intraoperative mapping.

Action Potentials↗
PubMed1990

Hemodynamic importance of systolic ventricular interaction, augmented right atrial contractility and atrioventricular synchrony in acute right ventricular dysfunction.

To delineate the determinants of right ventricular performance with acute right ventricular dysfunction, surgical electrical isolation of the right ventricular free wall was produced in 13 dogs. During atrioventricular (AV) pacing, hemodynamic and wall motion measurements were normal. When not paced, the right ventricular free wall became asystolic, resulting in a depressed and bifid right ventricular systolic pressure (33 +/- 5 to 18 +/- 4 mm Hg) and decreased left ventricular systolic pressure (100 +/- 18 to 80 +/- 18 mm Hg) and stroke volume (14 +/- 4 to 10.3 +/- 3.5 ml) (all p less than 0.05). Ultrasound demonstrated right ventricular free wall dyskinesia, increased right ventricular end-diastolic size (155 +/- 13% of control), but decreased left ventricular size (69 +/- 11% of control) (both p less than 0.05). Right atrial pressure increased (5.8 +/- 2.5 to 7.6 +/- 2.8 mm Hg, p less than 0.05) with an augmented A wave and blunted Y descent, indicating pandiastolic right ventricular dysfunction. The septum demonstrated reversed curvature in diastole and bulged paradoxically into the right ventricle during early systole, generating the initial peak of right ventricular pressure and reducing its volume. Later, posterior septal motion coincided with maximal left ventricular pressure and the second peak of the right ventricular waveform. Left ventricular pacing alone led to further decreases in right ventricular systolic pressure and size, left ventricular systolic pressure and stroke volume. The previously augmented A wave was replaced by a prominent V wave. Therefore, when contractility of its free wall is acutely depressed, right ventricular performance is dependent on left ventricular-septal contractile contributions transmitted by the septum.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Developmental changes of synapsin I subcellular localization in rat cerebellar neurons.

Synapsin I, one of the major synaptic proteins, is thought to associate with synaptic vesicles and to play a regulatory role in neurotransmitter release. In mature neurons, it is concentrated almost exclusively in presynaptic nerve endings. Here, we studied the subcellular localization of synapsin I during the development of rat cerebellar cortices by immunocytochemistry, using anti-synapsin I antibodies and found that during the development of rat cerebellar cortices it tentatively exists in the dendritic growth cones of immature internal granule cells and in the axonal growth cones of mossy fibers as well as mature presynaptic endings. Also, we found that synapsin I, in the axonal and dendritic growth cones does not necessarily associate with vesicles, but rather with fuzzy filamentous structures in the cytoplasm. In search of the structure of synapsin I in vivo, we employed the quick-freeze, deep-etch technique after immunogold labeling. Synapsin I seems to thereby connect synaptic vesicles or anchor them to cytoskeletons in presynaptic endings.

Animals↗
PubMed1990

Biatrial isolation--a new surgical treatment for supraventricular tachycardia.

Nine adult mongrel dogs were subjected to cardiopulmonary bypass and both right and left atria were surgically isolated, exclusive of the sinoatrial (SA) node, crista terminalis, and interatrial septum. Thus, the SA node remained in continuity with the ventricles despite biatrial isolation. Moreover, of the right and left SA node arteries, the predominant one (right in 7 dogs, left in 2 dogs) was spared. Postoperatively, normal SA node function was preserved in 8 out of 9 dogs, with no difference in sinus rhythm cycle length (preop: 446 +/- 25, postop: 434 +/- 22 sec, p = NS) or sinus node recovery time (preop: 488 +/- 28, postop: 487 +/- 32 msec, p = NS). Simulated supraventricular tachycardia was confined in the isolated right or left atria did not affect sinus rhythm in the remainder of the heart. One out of 9 dogs developed junctional rhythm postoperatively, indicating exclusion of the SA node or a fast atrial pacemaker. In the 8 dogs with postoperative sinus rhythm, the spared SA node artery was occluded at the end of each study. All dogs developed rhythm deterioration including sinus rhythm slowing with prolonged sinus node recovery time (4 dogs), sinus bradyarrhythmia (2 dogs) and atrioventricular nodal rhythm (2 dogs). Thus, biatrial isolation is feasible for the treatment of supraventricular tachycardia, but it is essential to preserve SA node blood supply in order to maintain normal sinus rhythm in the remainder of the heart.

Animals↗
PubMed1990

[Studies on the effectiveness of adjuvant hepatic arterial chemotherapy after hepatectomy for primary or metastatic liver cancer].

From January 1980 to March 1990, 399 cases of primary liver cancer (hepatocellular carcinoma 357, cholangiocellular carcinoma 42) and 148 cases of metastatic liver cancer were treated in our hospital. Some 222 of H.C.C (hepatocellular carcinoma), 20 of C.C. (cholangiocellular carcinoma) and 42 of metastatic liver cancer were resected; 24 of H.C.C, 2 of C.C and 22 of metastatic cancer received adjuvant hepatic arterial chemotherapy, in which anti-cancer drugs were administered with oily contrast medium Lipiodol in hepatic artery. The relationship between operative findings and postoperative prognosis was studied in 168 resected H.C.C cases and risk factors for recurrence were determined. Risk factors are TW(+), which means that the cancer remains macroscopically within 1 cm of surgical margin; IM(+), which means intrahepatic metastasis exists; more than Vp2, which means tumor embolus exists in the second or more proximal branch of the portal vein; and Fc(-), which means lack of capsule formation. In 132 cases with the risk factors, the survival rate of 19 cases with adjuvant arterial chemotherapy was significantly higher than that of 113 cases without it. In the cases of liver metastasis of colon cancer, resection of metastases and adjuvant hepatic arterial chemotherapy improved the prognosis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

[Nucleotide metabolism in remnant rat liver after major hepatic resection].

Major hepatic resection is restricted in the presence of cirrhosis, because the cirrhotic liver is less able to regenerate. In the present study, to clarify what factors play a major role as inhibitors of the regeneration process, we focused on the changes in liver purine nucleotides and their catabolite levels in rats with cirrhosis. Decreases in adenine nucleotides and guanine nucleotides were observed after resection both in normal and thioacetamide-induced cirrhotic livers. These were prolonged in rats with cirrhosis. Tissue levels of hypoxanthine and xanthine increased both in the control group and in the cirrhotic group. The increase in xanthine level was remarkable in the cirrhotic group compared with the control group. These results indicate that xanthine oxidase activity is increased in cirrhotic liver after major hepatic resection. Xanthine oxidase catalyzes the oxidation of hypoxanthine to xanthine and xanthine to uric acid. Xanthine and uric acid are end metabolites of purine nucleotides. On the other hand, superoxide is generated in association with this reaction. Therefore, the disturbance in the energy metabolism and the increase in superoxide formation which are caused by the activation of xanthine oxidase might be involved in the regeneration process as inhibitory factors in cirrhotic rat liver.

Animals↗