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Biomedical subjects

A Yamaguchi

Publications and source records attributed to A Yamaguchi.

At least 343 records · Page 19Linked to original sources
PubMed1995

[The glutamic acid decarboxylase (GAD) antibodies and their clinical significance].

Since it was reported that the 64kD antigen that had been found to be the target of autoantibodies in the sera from IDDM patients was the same as GAD, GAD antibodies have been one of the focuses of many investigations. In this study, we developed a sensitive radioimmunoassay (RIA) system for GAD antibodies in human sera using native GAD purified from the pig brain. To confirm the relevance of pig GAD as the target antigen, we compared the sequences and antigenic activities among pig, rat and recombinant human GAD65. Based on the data from our and other laboratories, the homology of amino acid sequences between pig and human GAD65 was 96.4%. The coefficient of correlation between the results of human and pig GAD RIA was 0.948. The GAD antibody study group confirmed the clinical usefulness of GAD antibodies not only for the diagnosis of IDDM but also slowly progressive IDDM.

Animals↗
PubMed1995

[Reoperation for recurrent or second primary lung cancer].

From 1975 to July 1994, twenty patients underwent second or third pulmonary resections for 7 recurrent lung cancers and 14 second primary lung cancers. The initial surgical procedures were lobectomy in 18, pneumonectomy in 1 and bilateral segmentectomy in 1. The procedures at the second operation were completion pneumonectomy in 4, ipsilateral wedge resection in 3, contralateral lobectomy in 1, contralateral segmentectomy in 4, contralateral wedge resection in 7 and resection of left main bronchus in 1. At the third operation, wedge resection was done in one 28 months after completion pneumonectomy. There was no operative death following second and third operations. Five-year survival rate following second operation in 20 patients was 32.3%, and it was 28.6% for patients with recurrent lung cancers, and 31.2% for multiple primary lung cancers. In conclusion, an aggressive surgical approach for reappearing lung tumor should be performed. At the reoperation, wedge resection for recurrent lung cancers, completion pneumonectomy for ipsilateral primary lung cancers and segmentectomy for contralateral primary lung cancers should be chosen for the standard surgical procedure.

Adenocarcinoma↗
PubMed1995

Hepatic histopathological changes in biliary pancreatitis.

OBJECTIVES: Elevation of serum transaminase has been shown to establish gallstone etiology in acute pancreatitis, but little has been reported regarding hepatic histopathological changes in biliary pancreatitis. The main purposes of this study were to observe hepatic histopathological changes in the acute stage of biliary pancreatitis and to elucidate the mechanism of transaminase elevation. METHODS: Microscopic findings for liver biopsy specimens (26 patients) as well as gross pathological observations of the biliary tract at emergency operation were analyzed in 62 patients with biliary pancreatitis. RESULTS: The main light microscopic findings were hepatocyte necrosis (96.2%) and acute cholangitis (65.4%). The main electron microscopic findings (two patients) were disorganized liver cell plate, retention of biliary material in the dilated canaliculi, and shedding of cytoplasm into the space of Disse in some areas. At laparotomy, impacted and floating bile duct stones were found in 35 (56.5%) and 13 (21.0%) patients, respectively, and acute inflammatory biliary diseases were encountered in 43 (69.4%) patients. CONCLUSIONS: The main hepatic histopathological changes in biliary pancreatitis were acute inflammatory hepatocyte necrosis, hepatocyte degeneration, and acute cholangitis caused by ampullary stones impacted during their transpapillary passage. Serum transaminase elevation might be a reflection of hepatocyte necrosis and/or degeneration.

Acute Disease↗
PubMed1995

[Modified David's operation for aortic regurgitation associated with annulo-aortic ectasia].

Composite graft replacement of the ascending aorta and aortic valve has been indicated for aortic regurgitation (AR) associated with annulo aortic ectasia (AAE). 29-year-old female with AR due to AAE associated with Marfan's syndrome underwent the replacement of ascending aorta by sparing an aortic valve with good result. Under cardiopulmonary bypass, the proximal ascending aorta was dissected circumferentially down to the ventriculo-aortic junction. The aneurysmal aorta and the all three sinuses of valsalva were excised, leaving 7 mm of arterial wall attached to the aortic valve and small buttons of arterial wall around the both left and right coronary arteries. The aortic valve was reimplanted inside a 28 mm Dacron graft which was calculated by aortic valve leaflet height. The left coronary artery was reimplanted to the graft by interposing a short 10 mm Dacron graft between coronary ostia and graft and the right coronary artery was anastomosed directly to the graft (Piehler's procedure). We called these procedure "modified David's operation". The patient has survived the operative procedure without any complications. Postoperative aortogram showed a competent aortic valve and the peak systolic pressure gradient across the aortic valve was 20 mmHg. We believe this new procedure preserving the native aortic valve is useful for preventing from some complications associated with artificial heart valves.

Adult↗
PubMed1995

[Successful surgical treatment of active infective endocarditis associated with perforation of aortic wall].

A 69-year-old man was transferred to our hospital because of severe progressive heart failure, eyeground hemorrhage due to embolism and uncontrollable inflammation. Emergent operation was suggested. Aortic valve replacement with a 23 mm Carpentier-Edwards bioprosthesis and patch closure of perforation using Dacron double velore was successfully performed. Vegetation was observed from the commissure between left and non coronary cusp to the aortic wall. Perforation (3 mm in diameter) and a moderate amount of bloody pericardial effusion were recognized. However periannular abscess was not detected. Postoperative course was uneventful and no recurrence of infection has been seen. We believe that surgical treatment for active infective endocarditis should be recommended when the bactericidal agents are ineffective and before the hemodynamics is suddenly deteriorated and the embolism occurs to the other organs.

Aged↗
PubMed1995

[Coronary artery perforation after directional coronary atherectomy (DCA)].

Directional coronary atherectomy (DCA) was performed on a 51-year-old man with unstable angina due to a 90% stenosis of the proximal side of the left anterior descending artery (LAD). A coronary angiography after the DCA showed the coronary artery perforation communicating with the pericardial space. He suffered cardiac tamponade and cardiogenic shock, and was taken to the emergent surgical intervention. The both side of the perforation was ligated to control active bleeding and coronary artery bypass grafting to the distal portion of the LAD was performed. It is stated that the incidence of tamponade resulting from vessel perforation after DCA is extremely rare.

Angina, Unstable↗
PubMed1995

[Successful valvuloplasty for isolated tricuspid regurgitation due to traumatic ruptured papillary muscle].

A 44-year-old man suffered from an traffic accident on May 27, 1994. He was transferred to a hospital because of emergent operation for a laceration of liver, right-sided hemothorax and pneumothorax. After surgical treatment for these lesions, he was doing well. However, systolic murmur appeared from August, 1994. By echocardiography and cardiac catheterization, he was diagnosed of isolated tricuspid regurgitation due to traumatic ruptured papillary muscle. Because right heart failure was progressive, an operation was recommended. At operation, annular dilatation of tricuspid valve and ruptured papillary muscle of anterior leaflet were found. And the ruptured end of right ventricular aspect was recognized. Therefore, we performed tricuspid valvuloplasty and annuloplasty. Postoperative course was uneventful. And residual regurgitation was not detected by right ventriculography. Especially, in patients with tricuspid regurgitation due to ruptured papillary muscle, symptoms usually begin soon after trauma. Therefore, an operation should be recommended promptly in the presence of right heart failure not relieved by medical treatment. And an earlier operation could increase the feasibility of tricuspid valvuloplaty, and the possibility of maintaining sinus rhythm.

Adult↗
PubMed1995

[Clinical significance of selective cerebral perfusion with cold blood on the brain protection].

In 42 patients with thoracic aortic disease, a selective cerebral perfusion with 16 degrees C cold blood was applied for the brain protection during the repair of the thoracic aorta. The surgical repair consisted of the replacement of the ascending aorta (9 cases), the ascending aorta and aortic arch (12 cases), the aortic arch (18 cases), and the aortic arch and descending aorta (3 cases). Twenty-two patients of them (52%) required emergency surgery and four patients died due to postoperative complications including visceral organ ischemia (2 cases) and multiple organ failure (2 cases). The mortality rate of this group was 18.2% (4/22 cases). In elective surgical classes, one patient died due to intraoperative coronary embolism. The mortality rate of this group was 5.0% (1/20 cases). No postoperative obvious brain defect was observed except one old patient (85-year-old female) with ruptured aortic arch who already had the brain infarction preoperatively. She died due to multiple organ failure with unconsciousness. Other patients including the patients with long cerebral perfusion (> 180 min) recovered well and returned to normal daily life. The selective cerebral perfusion with cold blood was easy to prepare and demonstrated the superb efficacy of brain protection in the patient.

Adult↗
PubMed1995

[Cerebral infarction after the cardiovascular operation].

From January, 1990 through July 1994, 615 adult patients were undergone cardiovascular operation under the cardiopulmonary bypass. Sixteen patients were suffered perioperative cerebral infarction. The etiology of the cerebral infarction was evaluated on the pre and postoperative brain CT findings by the neurologists. In the 283 coronary artery bypass operations, 4 patients suffered watershed infarction (WS) and 4 cerebral embolism. In the 252 valve operations, one WS and one embolism. In the 80 thoracic aortic operations, 5 WS and one embolism, respectively. The risk factors of WS were the elderly, emergency, the longer operative period, and the longer cardiopulmonary bypass period. The risk factor of the embolism were male, preoperative cerebral infarction, the calcified finding of the ascending aorta by the chest CT. It is important to take preventive strategies against the watershed infarction.

Adult↗
PubMed1994

Mutations of the adenomatous polyposis coli gene in the mutation cluster region: comparison of human pancreatic and colorectal cancers.

We analyzed the adenomatous polyposis coli (APC) tumor-suppressor gene as one of the possible genes mutated in human pancreatic carcinomas. DNAs from 39 surgical specimens were subjected to single-strand conformation polymorphism analysis of polymerase chain reaction products and the mutation cluster region (MCR) of the gene was examined. We also examined the same region of DNAs from 27 surgical specimens of sporadic colon carcinomas and detected mutations in 11 carcinomas (41%). This mutation frequency in colon carcinomas was similar to those reported previously. Using this system, we detected a mutated APC gene in one of 39 pancreatic carcinomas. The results indicated that mutation of the MCR in the APC gene is involved in genesis of some of human pancreatic carcinomas, but its frequency is much lower than in colorectal carcinomas.

Adenomatous Polyposis Coli↗
PubMed1994

Isolation of human nm23 genomes and analysis of loss of heterozygosity in primary colorectal carcinomas using a specific genomic probe.

Genomic clones of nm23-H1 and -H2 were isolated. The nm23-H1 and -H2 genes were located in a tandem array 4 kilobases apart. Each genome contained 5 exons and most of the splicing sites in the exon-intron junctions of two isotypes were essentially identical. A probe derived from intron 4 of nm23-H1 was used to examine the loss of heterozygosity (LOH) in primary colorectal carcinomas. Twenty-nine of 42 samples were informative and LOH was found in 3 of these 29. In all three samples with LOH, cancer tissues expressed lower levels of nm23-H1 mRNA when compared with those without LOH.

Amino Acid Sequence↗
PubMed1994

Tetracycline/H+ antiporter was degraded rapidly in Escherichia coli cells when truncated at last transmembrane helix and this degradation was protected by overproduced GroEL/ES.

The in vivo degradation of the plasmid-encoded tetracycline/H+ antiporter (TET) in Escherichia coli cells was studied using three mutants with carboxyl-terminal truncation at the positions in the hydrophilic carboxyl-terminal tail (TET388), in the last putative transmembrane helix XII (TET382), and immediately before the helix XII (TET365). All the mutant TET proteins were localized in the membrane. Expressed TET388 was active in transport and stable against proteolysis. However, TET382 and TET365 were inactive and proteolyzed rapidly. Thus, the importance of the helix XII for protease-resistant proper folding of TET is obvious. Interestingly, overproduced chaperonin (GroEL and GroES) partly prevented degradation of TET365.

Amino Acid Sequence↗
PubMed1994

Expression of human nm23-H1 and nm23-H2 proteins in hepatocellular carcinoma.

BACKGROUND: The expression of nm23-H1 and nm23-H2 proteins in 25 hepatocellular carcinomas was studied immunohistochemically. METHODS: Tissue specimens were reacted with anti-human nm23-H1 and nm23-H2 monoclonal antibodies (MoAb) (H1-229 and H2-206, respectively) and then stained by the biotin-streptoavidin complex method. RESULTS: Adjacent nontumorous tissues were intensely stained with nm23-H1 and nm23-H2. Of the 25 hepatocellular carcinomas, 60% were positive for MoAb H1-229, and 68% were positive for MoAb H2-206. These immunoreactivities were most common in the cytoplasm of tumor cells. There was no significant correlation between the expression of nm23-H1 protein and tumor size, Edmondson's histopathologic classification, or invasion of the capsule. However, the authors observed an inverse relationship between nm23-H1 expression and intrahepatic metastases of hepatocellular carcinomas. There was no significant correlation between the expression of nm23-H2 protein and clinicopathologic findings. Only a short survival period was observed in patients with hepatocellular carcinoma with reduced nm23-H1 or nm23-H2 proteins. CONCLUSIONS: The results suggest that nm23-H1 protein plays a role in the suppression of intrahepatic metastasis of hepatocellular carcinoma and that the combined expression of nm23-H1 is associated with favorable prognosis.

Carcinoma, Hepatocellular↗
PubMed1994

The role of gravity in chick embryogenesis.

Thirty fertilized chick eggs preincubated for 0, 7 and 10 days on earth (10 eggs each) were flown in the space shuttle 'Endeavour' and further incubated for 7 days under microgravity. Twenty out of thirty eggs (9/10 ten-day-old; 10/10 seven-day-old; 1/10 zero-day-old) were recovered alive after landing. The only living embryo of the zero-day-old group died 24 days after launch, and was comparable to a 16-day-old embryo. The high mortality of the 0-day-old eggs appeared to be related to the specific inner structure of the egg. Simulation experiments performed on earth indicated that when yolk stayed in the albumen for more than 2 days, most of the embryos died. The subtle difference in specific gravity between the yolk (1.029) and albumen (1.040) plays a critical role in early chick embryogenesis.

Animals↗