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Biomedical subjects

J Hayashi

Publications and source records attributed to J Hayashi.

At least 55 records · Page 3Linked to original sources

Segmental bronchial atresia of the left upper lobe treated with segmental resection under video-assisted thoracic surgery.

We report our experience of segmental bronchial atresia managed with segmental resection under video-assisted thoracic surgery. A 23-year-old woman reporting a cough, dyspnea, and back pain underwent segmental resection in which a stapling device was used under video-assisted thoracic surgery. Her postoperative course was uneventful with minimal pain and a disappearance of preoperative symptoms after surgery. Once an accurate preoperative diagnosis can be established, video-assisted thoracic segmentectomy together with the use of a stapling device is considered to be feasible.

Adult↗

[Long-term results of valve-retaining homograft and xenograft patch for transannular reconstruction of the right ventricular outflow tract in tetralogy of Fallot].

Thirteen patients with tetralogy of Fallot underwent reconstruction for hypoplastic right ventricular outflow tract using a preserved homograft or xenograft patch with single or double cusps. Homografts and xenografts preserved in 70% ethanol were implanted in 10 patients, and xenografts treated with glutaraldehyde were used in 3 patients. All the patients are doing well in their profession without one who died 18 years after operation. Valve-retaining homograft and xenograft patches provided excellent early hemodynamic function, but did not prevent pulmonary insufficiency late after the operation. Both homograft and xenograft cusps tended to degenerate several years after implantation, but cusp failure was not accompanied by outflow stenosis.

Adolescent↗

[A successful surgical case of incomplete atrioventricular septal defect with pulmonary dysfunction].

A 58-year-old female with incomplete atrioventricular septal defect was treated successfully with surgery. We repaired the defect by closure of atrioventricular septal defect, suture of cleft and tricuspid valve annuloplasty. We adopted method of minimally invasive cardiac surgery (MICS) expecting to preserve pulmonary function and to perform tracheostomy on early stage. After the operation she recovered with no major complications. It is suggested that MICS is effective method for patients with pulmonary dysfunction.

Cardiac Surgical Procedures↗

[An unconscious patients with ascending aortic aneurysm accompanied by aortic regurgitation successfully treated by emergency operation after cardiopulmonary resuscitation].

A-37-year-old woman in shock condition was transferred to our hospital after cardiopulmonary resuscitation for ventricular fibrillation. She was unconscious and suspected of suffering ischemic brain damage, with pathologic reflexes and weak brain stem reflexes. Brain CT scan showed cerebral edema without hemorrhage or infarction and an electroencephalograph revealed slow alpha-theta waves. Chest CT scan and echocardiogram showed ascending aortic aneurysm with sever aortic regurgitation. An emergent operation was performed for progression of heart failure. There were no distortion or dilatation of the sinus of Valsalva and annuloaortic ectasia and aortic valve leaflets were almost normal. We considered that the aortic valve dysfunction was cause by dilatation of the sinotubular junction. Ascending aortic and aortic valve replacement were carried out to shorten cardiopulmonary bypass time and to prevent the progression of brain damage. Mild hypothermia was employed as a neuroprotective procedure for three days after surgery. The patient's neurological symptoms, which were right hemiparesis, facial apraxia and motor aphasia, improved and she was discharged from the hospital on foot without any neurological complications on the 47th postoperative day and returned to work after two months.

Adult↗

[Osteoma originating in the dura: a case report].

We report a case of intracranial osteoma attached to the dura. The patient, a 35-year-old man, had suffered several episodes of vertigo over the previous two years. Physical and neurological findings on admission were unremarkable. A plain craniogram showed a dense calcified mass in the right frontal area, and CT revealed a homogeneous high-density mass without significant enhancement. MRI confirmed the dural origin of the lesion, which showed hyperintensity in the T1-weighted image and low intensity in the T2-weighted image. The mass was 5 cm in diameter and 2 cm in thickness. Total resection was performed under a preoperative diagnosis of calcified meningioma. Histopathology revealed the mass to be an osteoma. Osteomas are common benign bone tumors that usually arise from long bones of the extremities. Intracranial osteomas are extremely rare lesions. The literature on intracranial osteoma of dural origin is reviewed.

Adult↗

Prognostic value of genetically diagnosed lymph node micrometastasis in non-small cell lung carcinoma cases.

The predictive value of lymph node micrometastasis, detected by immunohistochemical or genetic methods, is well appreciated in terms of prognosis. However, a major problem is high false-positive rates, because most methods focus on cytokeratin, which is a component not only of carcinoma but also normal epithelial and nonepithelial cells. Mutant allele-specific amplification (MASA) can detect DNAs derived from cancer cells itself, reportedly with high sensitivity. It was, therefore, used with nested-PCR using p53 or K-ras mutation for analysis of lymph node micrometastasis in non-small cell lung carcinoma (NSCLC) patients in the present study, in comparison with the immunohistochemical method using an anti-cytokeratin reagent for the same samples. Lymph nodes from 31 NSCLC patients with p53 and K-ras mutated tumors (30 and 1, respectively) staged as pathological (p)-T1-4 N0-1 and M0 were examined. Genetic and immunohistochemical methods demonstrated positive reactions in 34 (15%) and 61 (27%) of 229 lymph nodes, respectively (9 cases, 29%, and 24 cases, 77%). The concordance with the two methods was 77%, but 13 (39%) of 34 genetically positive lymph nodes could not be detected by immunohistochemistry (IHC). Of 22 cases with p-N0 disease, 6 (27%) were genetically positive in hilar and/or mediastinal lymph nodes, and 4 (67%) of them died after cancer relapse. In contrast, none of the patients without micrometastasis died of cancer (P < 0.001, log rank analysis). Of the same p-N0 patients, 17 (77%) were positive by IHC, and 4 (24%) of them died of cancer, whereas 5 negative patients did not suffer cancer relapse. Survival did not significantly differ between cases positive and negative (P = 0.246) by IHC. According to the g-N (N factor restaged by a genetic method), patients with g-N1 and g-N2 disease had a shorter survival than those with g-N0 disease (P = 0.042 and P < 0.001, respectively). However, no significant difference was observed with grading by IHC. Thus, detection of micrometastasis in regional lymph nodes with the MASA method, in other words with a carcinoma-specific marker, is of greater prognostic significance for early stage NSCLC patients than immunohistochemical results. This approach should facilitate selection of patients for whom postoperative adjuvant chemotherapy should be performed.

Adenocarcinoma↗

A relationship between the evolution of hepatitis C virus variants, liver damage, and hepatocellular carcinoma in patients with hepatitis C viremia.

To clarify the mechanism of liver damage induced by hepatitis C virus (HCV) and to determine whether the damage is related to hepatocellular carcinoma (HCC), HCV RNA levels were measured serially, and HCV genome mutations were analyzed from serum of 274 Japanese patients with chronic HCV viremia during 1993-1998. All patients had alanine aminotransferase (ALT) levels measured during 1986-1998. Patients with consistently normal ALT levels had identical and highly conserved HCV core regions; however, those with consistently abnormal ALT levels had quasi species, and the population of the quasi species changed over time. HCV RNA levels did not change in the 274 patients. HCC developed in 31% of 80 patients with consistently abnormal ALT levels and in 4% of 92 patients with intermittently abnormal ALT levels but never in 102 patients with ALT levels consistently normal during 1993-1998. In patients with chronic HCV viremia, persistent liver damage plays an important role in the development of HCC.

Adult↗

Cloning and characterization of human Lnk, an adaptor protein with pleckstrin homology and Src homology 2 domains that can inhibit T cell activation.

Lnk was originally cloned from a rat lymph node cDNA library and shown to participate in T cell signaling. Human Lnk (hLnk) was cloned by screening a Jurkat cell cDNA library. hLnk has a calculated molecular mass of 63 kDa, and its deduced amino acid sequence indicates the presence of an N-terminal proline-rich region, a pleckstrin homology domain, and a Src homology 2 domain. When expressed in COS cells, hLnk migrates with an apparent molecular mass of 75 kDa. Confocal fluorescence microscope analysis indicates that in COS cells transfected with an expression vector encoding a chimeric Lnk-green fluorescent protein, hLnk is found at the juxtanuclear compartment and also appears to be localized at the plasma membrane. Lnk is tyrosine-phosphorylated by p56lck. Following phosphorylation, p56lck binds to tyrosine-phosphorylated hLnk through its Src homology 2 domain. In COS cells cotransfected with hLnk, p56lck, and CD8-zeta, hLnk associated with tyrosine-phosphorylated TCR zeta-chain through its Src homology 2 domain. The overexpression of Lnk in Jurkat cells led to an inhibition of anti-CD3 mediated NF-AT-Luc activation. Our study reveals a potentially new mechanism of T cell-negative regulation.

Adaptor Proteins, Signal Transducing↗

Development of a more rapid, reduced serum culture system for Caco-2 monolayers and application to the biopharmaceutics classification system.

The objectives were: (1) to develop a more rapid, reduced serum culture system for Caco-2 monolayers, relative to the traditional 21-day, 10% fetal bovine serum (FBS) system; and (2) to determine the biopharmaceutical drug classification of an oral therapeutic agent using this new system. Caco-2 cells were grown in the six well format on polycarbonate filters, in medium containing 2% iron supplemented calf serum (sCS) and a combination of growth factors and hormones. After 4 days in culture, permeabilities of three marker compounds (metoprolol, mannitol, and taurocholate) across monolayers were determined, and compared to permeabilities from the traditional 21-day, 10% FBS system, using cells at similar passage number. Cell morphology, degree of cell differentiation, and the presence of two efflux pumps were assessed. The 2% sCS model was also used to classify the permeability of an oral therapeutic agent as high or low. No difference in permeability was observed for metoprolol transport (P = 0.38) between the two culture methods, and the values obtained were independent of passage number of the cells. Mannitol permeability was about 2-fold higher from the 2% sCS system, as compared to the 10% FBS system. Taurocholate permeability was low indicating the 2% sCS culture at 4 days lacked this particular active transporter capability. Electron micrographs of cells grown in the 2% sCS system at 4 days revealed the presence of microvilli and tight junctions. P-glycoprotein and an efflux pump for furosemide were functionally present. The 2% sCS system indicated the oral therapeutic agent as highly permeable, which agreed with the 10% FBS system. This new system provides a rapid, accurate, and economical option for passive permeability determination, and appears to be applicable to the proposed Biopharmaceutics Classification System (BCS).

Adrenergic beta-Antagonists↗

Successful reconstruction in a patient with chronic and multisegmental venous obstruction: report of a case.

We describe herein our technique of performing complex venous reconstruction for a patient with chronic, multiple, and long segmental venous obstruction from the left iliac vein to the infrapopliteal deep veins. To improve venous outflow and prevent venous gangrene caused by graft failure, we preserved the ipsilateral saphenous vein without dissection and performed complex venous reconstruction in the form of iliofemoral crossover bypass using a prosthetic graft, femoropopliteal bypass using the contralateral saphenous vein, both thromboembolectomy and venous repair of the infrapopliteal veins, and the creation of a distal arteriovenous fistula. The successful outcome of this surgery may provide some insight into the treatment of extended chronic venous obstruction.

Aged↗

Different subtypes of human lung adenocarcinoma caused by different etiological factors. Evidence from p53 mutational spectra.

Human lung adenocarcinomas are only relatively weakly associated with tobacco smoke, and other etiological factors need to be clarified. These may also vary with the histopathology. Because the p53 mutation status (frequency and spectrum) of a carcinoma can provide clues to causative agents, we subclassified 113 adenocarcinomas into five cell types: hobnail, columnar/cuboidal, mixed, polygonal, and goblet (54, 23, 18, 13, and 5, respectively) and investigated relationships with p53 mutations and smoking history. In the hobnail cell type, a low mutational frequency (37%) and a high proportion of transitions (65%), especially G:C to A:T transitions at CpG dinucleotides (45%) associated with spontaneous mutations, were found with a weak relation to tobacco smoke. In contrast, a high mutation frequency (70%) with a higher proportion of transversions (50%), especially G:C to T:A (44%) on the nontranscribed DNA strand, caused by exogenous carcinogenic agents like tobacco smoke, were observed for the columnar cell type, as with squamous cell carcinomas. These results indicate that two major subtypes of lung adenocarcinoma exist, one probably caused by tobacco smoke, and the other possibly due to spontaneous mutations. For the prevention of lung adenocarcinomas, in addition to stopping tobacco smoking, the elucidation of endogenous mechanisms is important.

Adenocarcinoma↗

Changes in graft flow pattern from the descending aorta due to intraaortic balloon pump.

During surgery for lung cancer in a patient who had undergone coronary artery bypass grafting through the descending aorta by left thoracotomy, we measured graft bypass blood flow from the descending aorta under intraaortic balloon pump (IABP) assistance. Under IABP assistance, the diastolic waveform changed to a spiky pattern with a sharp drop in blood flow of approximately 16% compared to that without IABP assistance. We report changes in graft flow pattern during IABP assistance when the graft is placed from the descending aorta.

Aorta, Thoracic↗

Identification of actin binding protein, ABP-280, as a binding partner of human Lnk adaptor protein.

Human Lnk (hLnk) is an adaptor protein with multiple functional domains that regulates T cell activation signaling. In order to identify cellular Lnk binding partners, a yeast two-hybrid screening of human spleen cDNA library was carried out using human hLnk as bait. A polypeptide sequence identical to the C-terminal segment of the actin binding protein (ABP-280) was identified as a hLnk binding protein. The expressed hLnk and the FLAG tagged C-terminal 673 amino acid residues of ABP-280 or the endogenous ABP-280 in COS-7 cells could be co-immunoprecipitated using antibodies either to hLnk, FLAG or ABP-280, respectively. Furthermore, immunofluorescence confocal microscope showed that hLnk and ABP-280 co-localized at the plasma membrane and at juxtanuclear region of COS-7 cells. In Jurkat cells, the endogenous hLnk also associates with the endogenous ABP-280 indicating that the association of these two proteins is physiological. The interacting domains of both proteins were mapped using yeast two-hybrid assays. Our results indicate that hLnk binds to the residues 2006-2454 (repeats 19-23C) of ABP-280. The domain in hLnk that associates with ABP-280 was mapped to an interdomain region of 56 amino acids between pleckstrin homology and Src homology 2 domains. These results suggest that hLnk may exert its regulatory role through its association with ABP-280.

Actins↗

Pulmonary complications after surgical treatment of lung cancer in octogenarians.

OBJECTIVE: The purpose of this study was to analyze the risks associated with pulmonary resection for primary non-small cell lung cancer in octogenarians to help better management in these patients. METHODS: We reviewed the outcome in our 35 patients aged 80 years and older who underwent pulmonary resection between 1981 and 1998. RESULTS: The 5-year survival rate was 39.8%. The operative mortality rate was 0% and the morbidity 60%. There were ten major pulmonary complications, including respiratory insufficiency following bacterial pneumonia and sputum retention. Preoperative arterial pO(2) was significantly lower, A-aDO(2) was significantly higher, and operation time were significantly longer in patients with pulmonary complications after surgical treatment than in patients without complications (P<0.05). CONCLUSIONS: Surgical treatment was not contraindicated for octogenarians with lung cancer. However, a relatively preoperative low arterial pO(2), high A-aDO(2), and long operation time may be risk factors for postoperative pulmonary complications in such patients. Surgeons must assess the preoperative data prudently to determine appropriate surgical strategy.

Actuarial Analysis↗