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Biomedical subjects

H Akashi

Publications and source records attributed to H Akashi.

At least 37 records · Page 2Linked to original sources
PubMed2001

Repair of left ventricular rupture following mitral valve replacement concomitant with left atrial reduction procedure--intracardiac patch and extracardiac buttress suture.

Rupture of the posterior wall of the left ventricle after mitral valve replacement is a dire complication associated with a very high mortality. This study reports a successful repair of type I left ventricular rupture, which occurred after mitral valve replacement concomitant with a left atrial reduction procedure, by combination of an intracardiac patch and an extracardiac buttress suture. In a case such as this, in which hemostasis is quite difficult to establish, this combination technique is particularly effective.

Female↗
PubMed2001

Unruptured aneurysm of the right coronary sinus of Valsalva with type B aortic dissection.

A seventy-two year-old man, who complained of severe back pain, was referred to our hospital. Digital subtraction angiogram (DSA) delineated an extracardiac unruptured aneurysm of the right coronary sinus of Valsalva and acute type B aortic dissection. Patch plasty of the right coronary sinus with reimplantation of the right coronary artery using a Dacron graft was performed. Postoperative DSA confirmed successful reconstruction of the aortic root and the patent right coronary artery.

Aged↗
PubMed2000

A test of translational selection at 'silent' sites in the human genome: base composition comparisons in alternatively spliced genes.

Natural selection appears to discriminate among synonymous codons to enhance translational efficiency in a wide range of prokaryotes and eukaryotes. Codon bias is strongly related to gene expression levels in these species. In addition, between-gene variation in silent DNA divergence is inversely correlated with codon bias. However, in mammals, between-gene comparisons are complicated by distinctive nucleotide-content bias (isochores) throughout the genome. In this study, we attempted to identify translational selection by analyzing the DNA sequences of alternatively spliced genes in humans and in Drosophila melanogaster. Among codons in an alternatively spliced gene, those in constitutively expressed exons are translated more often than those in alternatively spliced exons. Thus, translational selection should act more strongly to bias codon usage and reduce silent divergence in constitutive than in alternative exons. By controlling for regional forces affecting base-composition evolution, this within-gene comparison makes it possible to detect codon selection at synonymous sites in mammals. We found that GC-ending codons are more abundant in constitutive than alternatively spliced exons in both Drosophila and humans. Contrary to our expectation, however, silent DNA divergence between mammalian species is higher in constitutive than in alternative exons.

Alternative Splicing↗
PubMed2000

Growth-suppressive effect of non-steroidal anti-inflammatory drugs on 11 colon-cancer cell lines and fluorescence differential display of genes whose expression is influenced by sulindac.

In addition to an anti-inflammatory effect, sulindac, one of the non-steroidal anti-inflammatory drugs (NSAIDs), has been shown to have a protective effect against the incidence and mortality of colorectal cancer. However, the molecular basis of its anti-proliferative function remains unclear. To investigate its molecular mechanism, we exposed 11 colon-cancer cell lines to NSAIDs such as aspirin, sulindac and the sulfide and sulfone metabolites of sulindac. Sensitivity to these drugs was dose- and time-dependent but varied from one cell line to another. Among the cell lines examined, sulindac showed a moderate anti-proliferative effect on HT-29 colon cancer cells and caused morphological changes, including an increase of cells with abnormal DNA content. We used the mRNA fluorescence differential display method with these cells to identify molecules that might contribute, through altered expression, to cellular changes in response to NSAIDs. Sixty-eight cDNA fragments were confirmed by RT-PCR to have significantly different expression levels following sulindac treatment. Thirty of these fragments proved to be novel cDNA sequences or identical to expressed sequence tags; the other 38 fragments were identical, or showed significant homology, to genes whose function was already known. Among the known genes differentially expressed in HT-29 cells after sulindac treatment were those encoding acetylglucosaminyltransferase, ferritin heavy chain, zinc finger protein 165, aldose reductase, carcinoembryonic antigen, aldoketoreductase, NF-kappaB-activating kinase, lysosome-associated protein, RhoE = 26 kDa GTPase homologue, NADH oxidoreductase, G/T mismatch bindingprotein, TM7SF3, ADP/ATP carrier-like protein and chromosome segregation protein. This variety among classes of proteins affected by sulindac in our experiments underscores the complexity of anti-proliferative mechanisms that may operate in colon-cancer cells treated with NSAIDs. Furthermore, identification of genes regulated by NSAIDs in colon-cancer cells should provide useful information to identify novel therapeutic targets for treatment and/or prevention of colon cancer.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2000

Cerebral protection selection in aortic arch surgery for patients with preoperative complications of cerebrovascular disease.

OBJECTIVE: Retrograde perfusion is gaining acceptance as a means of cerebral protection, but it remains unclear how long the brain is protected and whether it is effective in patients with preoperative cerebrovascular disease. METHODS: From January 1989 to August 1999, 205 patients--118 male and 87 female patients who ranged 12 to 86 years old, mean: 65.5 years old--underwent surgery at our hospital for aortic arch aneurysm using cerebral protection. We focused on mortality, stroke incidence and perioperative risk factor between 2 groups--selective cerebral and retrograde cerebral perfusion--also studying patients with preoperative cerebrovascular disease that influenced postoperative stroke. RESULTS: The hospital mortality was 11.7% (selective cerebral perfusion group: 12%, retrograde group: 10.9%). Stroke occurred in 11 patients (5.3%), 4.7% in the selective cerebral perfusion group and 7.3% in the retrograde group. Preoperative cerebrovascular disease does not appear to be a risk factor for postoperative brain damage in aortic arch surgery. Regarding total replacement of the aortic arch, the incidence of postoperative brain damage in the retrograde group with preoperative cerebrovascular disease was higher than that in another group (p = 0.072). Cardiopulmonary bypass time and selective cerebral perfusion time in the patients with postoperative stroke were significantly longer than that in non-stroke group. CONCLUSIONS: Preoperative cerebrovascular disease did not appear to be a risk factor in postoperative neurological deficit in the selective cerebral perfusion group. Prolonged selective cerebral perfusion time and cardiopulmonary bypass time may, however, lead to brain edema and cause neurological deficit.

Adolescent↗
PubMed2000

Large acinar cell carcinoma of the pancreas in a patient with elevated serum AFP level.

A pancreatic carcinoma, associated with elevated serum alpha-fetoprotein level, was resected from a 67-year-old man. The tumor was strongly suggested to be an acinar cell carcinoma of the pancreas, based on the histological findings of the resected specimen. The tumor measured 12 x 10 x 9 cm, and the cut surface was soft, whitish-yellow, focally necrotic, and hemorrhagic. Under a light microscope, the tumor cells were not arranged in a tubular and trabecular pattern, but rather, showed a tendency toward an acinar structure. Immunohistochemically, alpha 1-antitrypsin- and alpha 1-antichymotrypsin-positive reactions were diffusely positive in most of the tumor cells, while staining for chromogranin, neuron-specific enolase, Grimelius, glucagon, insulin, and alpha-fetoprotein was negative in the tumor cells. We report a large acinar cell carcinoma (associated with elevated serum alpha-fetoprotein level), which had been misdiagnosed as hepatocellular carcinoma preoperatively.

Aged↗
PubMed2000

Surgical treatment for graft stenosis after repair of an interrupted aortic arch: report of two cases.

We report herein two cases of patients who underwent successful reoperation for graft stenosis after repair of an interrupted aortic arch (IAA). The first patient was a 10-year-old girl who suffered from upper limb hypertension 9 years after her initial operation. Cardiac catheterization revealed a pressure gradient of 55 mmHg across the repaired arch. At reoperation, a left subclavian turndown anastomosis was performed, following which the hypertension resolved and a cardiac catheterization done 5 years later demonstrated sufficient growth of the restored arch with no significant gradient. The second patient was a 17-year-old boy who suffered from general fatigue and intermittent hypertension 12 years after his initial operation. Cardiac catheterization revealed a gradient of 60 mmHg across the repaired arch. He underwent an extraanatomic ascending to descending aortic bypass employing an additional 18-mm graft, and a postoperative cardiac catheterization showed no gradient between the ascending and descending aorta. Our experience has shown that IAA should be repaired without prosthetic grafts if possible. Although extraanatomic bypass is useful for reducing the operative risks at reoperation, a large graft should be used to avoid the need for a third operation. For young children expected to outgrow a second graft, performing an endogenous anastomosis, such as a left subclavian turndown anastomosis, should be considered as an alternative.

Adolescent↗
PubMed2000

Isolation and characterization of a human cDNA encoding a protein homologous to the 7.2-kDa protein (subunit X) of bovine ubiquinol-cytochrome C reductase.

Through large-scale sequencing of clones randomly selected from a library of human cDNAs, we have isolated a novel human gene termed hUQCR10. Its open reading frame encodes 63 amino acids that share 88.5% identity with the sequence of bovine ubiquinol-cytochrome C reductase 7.2-kDa protein (subunit X). A single 0.6-kb transcript was expressed in all human tissues examined, but was particularly abundant in heart and skeletal muscle, tissues that consume a large amount of oxygen. The gene product therefore may play a significant role in the cellular respiratory system. In support of this hypothesis, our immunohistochemical analysis revealed that the hUQCR10 protein is located in mitochondria. A homology search using computer programs determined the chromosomal localization of the gene at 22q12.

Animals↗
PubMed2000

Biocompatibility of heparin-coated extracorporeal bypass circuits: new heparin bonded bioline system.

Biocompatibility of a new type of heparin-coated cardiopulmonary bypass equipment, the Bioline, was evaluated in coronary artery bypass surgery cases. The heparin-coated (H) group (n = 15; Quadrox Bioline oxygenator/reservior and Carmeda BioMedicus BP-80 centrifugal pump) was compared with the nonheparin-coated (N) group (n = 12; uncoated, otherwise similar oxygenator, centrifugal pump, tubing, and filter set). Both groups used full systemic heparinization. The peak values of neutrophil elastase, C3a, IL-6, and IL-8 at 2 h after cardiopulmonary bypass (CPB), and C3a levels at the end of CPB and at 2 h after CPB were significantly reduced in the H group compared with those of the N group. However, no statistically significant intergroup differences were observed in thrombin-antithrombin complex, D-dimer, beta-thromboglobulin, or platelet factor-4. No significant differences were observed in hemostasis time, postoperative 12 h blood loss, required amount of blood transfusion, or intubation time. In conclusion, the Bioline demonstrated partially improved biocompatibility, in terms of leukocyte and complement activation, and proinflammatory cytokine production. However, it did not improve platelet activation, coagulation, or fibrinolysis cascade under full systemic heparinization. As a result, the clinical beneficial impact seemed to be the minimum.

Aged↗
PubMed2000

Obstruction of St Jude Medical valves in the aortic position: significance of a combination of cineradiography and echocardiography.

BACKGROUND: Obstruction of the St Jude Medical valve (St Jude Medical, Inc, St Paul, Minn) is a rare but serious complication. METHODS: Cineradiographic and echocardiographic evaluations of aortic St Jude Medical valves were simultaneously performed on 54 patients, with no signs of prosthetic valve dysfunction late after surgery. RESULTS: Although closing angles of the leaflets corresponded closely with the manufacturer data, restricted opening of the leaflets (opening angle >/= 20 degrees ) was found in 16 (group D) of the 54 patients by means of cineradiography. The opening angles were equal to or less than 14 degrees in the other 23 patients (group N) and between 15 degrees and 19 degrees in the remaining 15 (group M). Doppler-derived transprosthetic pressure gradients were significantly higher (P =.03) and the velocity index was significantly lower (P =.003) in group D than in group N. However, no significant differences were found in those values between group N and group M. Replacement of the aortic St Jude Medical valves was performed in 5 of the 16 patients, and the remaining 11 have been followed up because of relatively low pressure gradients. The cause of restricted leaflet movement was pannus formation without thrombosis in 4 patients and valve thrombosis with pannus formation in one. CONCLUSIONS: Reduced valve orifice area and restricted opening of the leaflets resulting from excess growth of pannus probably led to obstruction of the aortic St Jude Medical valves. A combination of cineradiography and echocardiography makes it possible to provide an accurate and detailed diagnosis of obstruction of the valve.

Adolescent↗
PubMed2000

Isolation and characterization of a novel gene encoding a putative seven-span transmembrane protein, TM7SF3.

As part of a project involving large-scale sequencing of clones randomly selected from a human cDNA library, we isolated a novel human gene, termed TM7SF3 (transmembrane 7 superfamily member 3). Its open reading frame encodes a 570 amino acid protein containing seven putative transmembrane domains. The transcript of this gene was expressed in all human tissues examined, but most abundantlyin kidney. Immunocytochemical analysis demonstrated subcellular localization of TM7SF3 protein at the plasma membrane. We determined the chromosome location of TM7SF3 as 12q11.2-->q12 by a combination of fluorescence in situ hybridization and radiation hybrid mapping.

Amino Acid Motifs↗
PubMed2000

Isolation and chromosomal assignment of a novel human gene, CORO1C, homologous to coronin-like actin-binding proteins.

We have isolated a gene, termed CORO1C (human coronin-like actin-binding protein 1C), that encodes a new member of the coronin-like family of proteins. The cDNA consists of 3,857 nucleotides, with an open reading frame of 1,422 bp encoding a 474 amino acid protein. The deduced amino acid sequence shared 65% identity with p57 (human coronin-like actin-binding protein), as well as 46% identity with coronin, a protein first isolated from the slime mold Dictyostelium discoideum. Computer analysis predicted that the product of the CORO1C gene would contain five WD repeats in its N-terminal region and a coiled-coil motif in its C-terminal region, both of which are conserved among coronin-like proteins. CORO1C was ubiquitously expressed in all human tissues examined, in contrast to other known coronin-like molecules, each of which is expressed in a tissue-specific manner. Immunocytochemical staining demonstrated that CORO1C was co-localized with F-actin; therefore, the gene product is likely to be important in cytokinesis, motility, and signal transduction, as are the other members of this molecular family. We assigned this novel gene to chromosome 12q24.1 by fluorescence in situ hybridization.

Actins↗
PubMed2000

Surgical treatment for acute type A aortic dissection in pregnancy: a case of aortic root replacement just after Cesarean section.

A 25-year-old woman with Marfan syndrome in the 37th week of pregnancy was referred for acute chest pain and dyspnea. An emergency Cesarean section was performed because of fetal distress. Intraoperative echocardiography at the end of the Cesarean section showed dilatation of the aortic root and dissection of the ascending aorta. The patient underwent replacement of the aortic root and the ascending aorta on the following day because of uterine bleeding. The postoperative course was uneventful for the mother and her baby.

Adult↗
PubMed2000

In vitro detection of equine arteritis virus from seminal plasma for identification of carrier stallions.

Equine arteritis virus (EAV) was readily isolated in RK-13 cell monolayers by plaque assay from seminal plasma of experimental carrier stallions when they contained high titers of virus regardless of the presence of non-viral cytotoxicity in the seminal plasma. The cytotoxicity interfered with virus isolation from seminal plasma which contained virus at titers less than 10 PFU/ml. However, it was possible to detect the virus in seminal plasma pretreated with PEG (#6000). EAV was consistently identified by RT-PCR from crude seminal plasma which contained virus at titers of more than 10(2.7) PFU/ml. In vitro detection of EAV by virus isolation supplemented with RT-PCR using seminal plasma was proved to be an effective alternative to the standard test mating as a diagnostic method for carrier stallions.

Animals↗
PubMed2000

Successful removal of an infected pacemaker electrode by open heart surgery under extracorporeal circulation.

A 33-year-old male with sick sinus syndrome, who had received a pacemaker implant 18 years earlier, was complicated with a generator infection. Although the infected generator was removed, he was suffered from the recurrent local infection associated with a retained pacemaker lead. After a new pacemaker system implantation from the other side of the subclavian vein, we attempted to remove the lead utilizing a pacemaker removal kit. However, this intervention procedure was unsuccessful, because fibrous adhesions had developed around the lead, accompanied by calcification along its course. As a last resort, we opened the heart under extracorporeal circulation and removed the lead under direct vision. The post-operative course was uneventful. In order to remove a long-term implanted pacemaker lead, the direct surgical procedure with extracorporeal circulation is a favorable mean alternative to conventional intervention techniques.

Adult↗
PubMed1999

Within- and between-species DNA sequence variation and the 'footprint' of natural selection.

Extensive DNA data emerging from genome-sequencing projects have revitalized interest in the mechanisms of molecular evolution. Although the contribution of natural selection at the molecular level has been debated for over 30 years, the relevant data and appropriate statistical methods to address this issue have only begun to emerge. This paper will first present the predominant models of neutral, nearly neutral, and adaptive molecular evolution. Then, a method to identify the role of natural selection in molecular evolution by comparing within- and between-species DNA sequence variation will be presented. Computer simulations show that such methods are powerful for detecting even very weak selection. Examination of DNA variation data within and between Drosophila species suggests that 'silent' sites evolve under a balance between weak selection and genetic drift. Simulated data also show that sequence comparisons are a powerful method to detect adaptive protein evolution, even when selection is weak or affects a small fraction of nucleotide sites. In the Drosophila data examined, positive selection appears to be a predominant force in protein evolution.

DNA↗
PubMed1999

Concentric wear of the Delrin disc in a Bjork-Shiley heart valve prosthesis: report of two cases.

We report herein the cases of two patients who received replacement of aortic Bjork-Shiley Delrin (BSD) valves that had been implanted for over 20 years following the development of aortic regurgitation (AR) resulting from wear of a Delrin disc. Case 1 was a 61-year-old woman in whom echocardiography revealed marked left ventricular dilatation and moderate AR 23 years after an aortic valve replacement (AVR) with a 21-mm BSD valve. Case 2 was a 51-year-old woman in whom echocardiography revealed marked dilation of the right atrium and moderate AR 23 years and 8 months after an AVR with a 21-mm BSD valve, as well as a mitral valve replacement with a 3M Starr-Edwards (SE) ball valve and tricuspid annuloplasty. In both patients, the BSD valves were replaced with other mechanical valves at reoperation. Examination of the explanted BSD valves showed that the Delrin discs contained increases in the radial gaps and strut indentation grooves on the inflow and outflow surfaces. The type and magnitude of the wear on the Delrin discs in these valves were consistent with data reported in the literature for this valve design after similar implant duration.

Aortic Valve↗