Biomedical subjects

Y Terada

Publications and source records attributed to Y Terada.

At least 289 records · Page 16Linked to original sources

PubMed1992

[The calcified ascending aorta--preoperative evaluation and intraoperative management].

Aortic calcification was evaluated preoperatively by computed tomography (CT) in 136 of 275 candidates for coronary artery bypass surgery (age range, 30-80) years (mean 60.2 years), including 110 men and 26 women), from April 1989 to March 1991. Calcification in the mid-ascending aortic wall was detected in 20 (14.7%) cases, calcification in all regions of the aorta was more common in patients older than 60 years (22.5%, n = 71), than younger (6.2%, n = 65) (p less than 0.01). Atherosclerosis of the ascending aorta was identified intraoperatively in 25 (18.3%) cases. Practically, the specificity of CT findings was excellent (98.3%), but the sensitivity was less satisfactory (72.0%) due to the presence of atherosclerosis without calcification. In cases of arteriosclerosis of the ascending aorta, great care was taken to prevent embolism secondary to a dislodged atheromatous plaque. The "aortic no-touch technique", with in situ internal thoracic artery and right gastroepiploic artery anastomosis under ventricular fibrillation, was performed in 6 cases, a single aortic cross-clamp was applied in 19 cases, and conventional methods were employed when the ascending aorta was normal or the "no-touch" or "single-clamp" procedure could not be used (control, 111 cases). No neurologic complications occurred in the "no-touch" group, while 2 cerebral infarctions occurred in the single-clamp group (10.5%) and the control group (1.8%) respectively. These differences between groups was not significant. Patients with a calcified ascending aorta are at higher risk for neurologic complications of coronary bypass. The risk can be decreased by minimizing surgical trauma to the ascending aorta by the use of "no-touch" techniques.

Adult↗

PubMed1992

[An adult case of dyspnea and overinflation of the residual lung with disappearance of the postpneumonectomy space after left pneumonectomy].

Mediastinal shift and overinflation of the residual lung after pneumonectomy are well known, and sometimes cause pulmonary insufficiency. However, most of such cases occur after surgery in childhood or adolescence. We present a 49-year-old woman who had dyspnea and severe overinflation of the residual lung after left pneumonectomy. She had undergone pneumonectomy at the age of 33 years. Dyspnea on exertion occurred 4 years later, and became much more severe 9 years later (H-J IV degrees). Computed tomography showed that the postpneumonectomy space and completely disappeared and the right lung was overinflated to the left posterior axillary line. Low vital capacity with high residual volume and low maximal ventilatory volume were detected by pulmonary function test. Pulmonary function after pneumonectomy is difficult to predict because mediastinal shift and overinflation of the residual lung may occur. To avoid this, prosthesis plombage for the postpneumonectomy space is necessary.

Dyspnea↗

PubMed1992

[A case of pulmonary leiomyosarcoma followed up for five years].

A 70-year-old woman with leiomyosarcoma, followed up for 5 years as tuberculoma, is described. The tumor, in the left lower lobe, had enlarged from 1.5 x 1.5 cm to 3.4 x 3.4 cm in 5 years, and doubling time was calculated to be 540 days. Another tumor (1.8 x 1.8 cm) was also recognized in the right lower lobe at the later time. Since not only a benign tumor but metastatic disease was suspected, thoracotomy was performed, and the intraoperative pathologic diagnosis was leiomyosarcoma. However, only partial lung resection was performed because of the low growth rate of the tumor, the patient's advanced age, limited lymphatic metastasis and favorable prognosis with only partial resection. DNA analysis of the tumor based on flow cytometry showed a diploid pattern, and this was thought to account for the long doubling time of the tumor. The postoperative course was satisfactory without any signs of recurrence at the operation site.

Aged↗

PubMed1992

Signal transduction cascade shared by epidermal growth factor and platelet-derived growth factor is a major pathway for oncogenic transformation in NRK cells.

We have isolated two recessive, mutually complementary NRK cell mutants that are refractory to transformation by epidermal growth factor (EGF) and transforming growth factor-beta. Both mutants are defective in a signal transduction cascade shared by EGF and platelet-derived growth factor (PDGF). Analysis of the mutants suggests that transformation of NRK cells by the v-fms, v-erbB, activated erbB-2, v-ras, v-fos, v-mos, v-fes, v-src, SV40 large T, polyomavirus middle T, and human papillomavirus type 16 E6,E7 oncogenes is mediated by the EGF/PDGF signal cascade. The data also suggest that the EGF/PDGF cascade branches into mitogenic and oncogenic signals, the latter of which is required for soft agar growth and focus formation.

Animals↗

PubMed1992

Oncogenic signal-induced ability to enter S phase in the absence of anchorage is the mechanism for the growth of transformed NRK cells in soft agar.

Upon neoplastic transformation, cells acquire the ability to grow in soft agar. We investigated how this occurs by cell cycle analysis of a rat cell line NRK-49F and its transformation-deficient mutants. Rapidly growing NRK and mutants arrest in G1 when deprived of anchorage by suspending in methylcellulose. Addition of epidermal growth factor (EGF) together with transforming growth factor-beta (TGF-beta), which is highly oncogenic to NRK, induces the rapid progression of G1-arrested NRK cells into S phase. The time course and the extent of synchronization are very similar to the cell cycle progression in the presence of anchorage. EGF alone, which is highly mitogenic but only slightly oncogenic, fails to induce such progression. Both mutants remain arrested in G1. These data indicate that oncogenic signals confer on NRK the ability to enter S phase in the absence of anchorage and that this is the principal mechanism for its ability to grow in soft agar.

Agar↗

PubMed1992

[Coronary artery bypass grafting by utilizing the artery grafts and bovine internal thoracic artery graft (Bioflow in an elderly patient)].

We performed coronary artery bypass grafting (CABG) in a 80-year-old male with calcified ascending aorta and severe varicose veins utilizing the bilateral internal thoracic arteries and the right gastroepiploic artery under fibrillatory arrest without aortic cross-clamp (aortic no-touch technique). After triple coronary artery bypass grafting was completed, heart failure occurred. Additional Bioflow graft to the circumflex artery restored good cardiac function. The aortic no-touch technique is a useful method for CABG in patients with severe calcified ascending aorta. This experience suggests that the Bioflow graft is a helpful conduit at an urgent situation in CABG.

Aged↗

PubMed1992

[A case of miliary tuberculosis and chest wall cold tuberculous abscess with contents draining into the epidural space].

A 37-year-old man was admitted because of miliary tuberculosis. However, his fever and general condition did not improve with chemotherapy. Six months later, paraplegia occurred following sudden radicular back pain without any alteration of segmental sensation. There were no abnormal findings on X-ray films of the thoracic and lumbar vertebrae. Examination by magnetic resonance imaging revealed that the contents of a cold tuberculous abscess in the right chest wall had drained into the epidural space through the intervertebral foramen. Drainage of the chest wall abscess and laminectomy were performed. Further investigation showed that this case did not belong to the usual type of atypical spinal tuberculosis reported previously.

Abscess↗

PubMed1992

[A case of primary pulmonary paraganglioma].

A case of primary paraganglioma of the lung in a 48-year-old woman is presented. She was found to have a coin lesion in lower lobe on routine radiography. Results of bronchoscopic examination were negative, and exploratory right thoracotomy was performed. At operation, non-invasive encapsulated tumor found in posterior basal segment of the right lower lobe was enucleated. Histological analysis of the resected tumor proved to be compatible with pulmonary paraganglioma. Pulmonary paraganglioma is said extreme rare, and so only 21 cases were previously reported in the literature including this case.

Female↗

PubMed1991

Central nervous system damage following surgery using cardiopulmonary bypass--a retrospective analysis of 1386 cases.

In order to determine the incidence and risk of central nervous system damage (CNSD) which accompanies cardiovascular surgery, a retrospective analysis was carried out on 1386 patients who received surgery utilizing cardiopulmonary bypass. CNSD occurred in 32 of the 1386 patients, the total incidence being 2.3 per cent. The major risk factors which led to a high incidence of CNSD were found to be reoperation, thrombus in the left atrium (TLA) and calcification of the ascending aorta (Cal aAo). In the primary surgical series, CNSD was found in only 29 of 1350 patients (2.2 per cent), however, of a total 36 patients who underwent reoperation, 3 (8.3 per cent) patients developed CNSD (p less than 0.05). In a surgical series done on 562 patients with mitral valve disease, the prevalence of CNSD was much higher in patients who suffered TLA than in those who did not, being 4/85 cases (4.7 per cent) vs 11/477 cases (2.3 per cent), respectively. Moreover, a significantly higher incidence of CNSD was noted in patients with Cal aAo, occurring in 6/10 cases (60 per cent) with Cal aAo vs 4/333 cases (1.2 per cent) without Cal aAo (p less than 0.001). The results of this study showed that patients with CNSD, who had received coronary artery bypass surgery and aortic arch replacement tended to follow a poor clinical course, suggesting that atheromatous plaque embolization may be the leading cause of the poor prognosis following CNSD in patients having undergone cardiopulmonary bypass.

Adult↗

PubMed1991

Intraoperative coronary angiography using fluorescein.

Intraoperative coronary angiography using fluorescein was applied to evaluate the patency of saphenous vein grafts just after completion of the distal anastomosis. By this technique, the area of the revascularized myocardium was well estimated in real time. This intraoperative direct-vision examination gives us more timely and precise information during coronary artery bypass grafting.

Anastomosis, Surgical↗

PubMed1991

The peripheral distribution of trigeminal nerve fibres in the rat temporomandibular joint studied by an anterograde axonal transport method with wheat germ agglutinin-horseradish peroxidase.

Wheat germ agglutinin-horseradish peroxidase was injected into the trigeminal ganglion to trace the peripheral distribution of the nerve fibres in the temporomandibular joint. It was transported anterogradely along trigeminal nerve fibres. Horseradish-peroxidase-labelled nerve fibres were found in the anterior and posterior bands of the articular disc, and terminated as nerve endings near the intermediate zone of the disc. However, the intermediate zone itself did not contain any nerve endings. Other nerve fibres penetrated from the subsynovial layer into the synovial membrane and also terminated as nerve endings close to the articular cavity. Thus, this method is suitable for tracing peripheral nerve fibres and nerve endings originating in the trigeminal ganglion.

Animals↗

PubMed1991

1H-NMR study of the intramolecular interaction of a substrate analogue covalently attached to aspartic acid-101 in lysozyme.

We prepared the lysozyme derivative in which the beta-carboxyl group of Asp101 was modified with alpha-O-methyl N-glycylglucosaminide as an amide by means of the carbodimide reaction (alpha-MGG lysozyme). Since Asp101 residue is located at the edge of the active site cleft, a 1H-NMR study was carried out for this derivative in order to investigate the interaction between the introduced substituent and the active site cleft. It was confirmed that the alpha-MGG moiety sat in the active site cleft in alpha-MGG lysozyme from the reduction of line broadening of the NH-proton of Trp63 located in the active site cleft, the remarkable chemical shift change of the methyl group of the alpha-MGG moiety upon adding a trimer of N-acetyl-D-glucosamine [(NAG)3], and the NOE between the C6-proton resonance of Trp63 and the methyl resonance of the alpha-MGG moiety. Furthermore, alpha-MGG lysozyme had increased thermal stability compared with native lysozyme. Therefore, it was concluded that the alpha-MGG moiety covalently attached to Asp101 interacted with the active site cleft to increase the thermal stability of lysozyme.

Animals↗

PubMed1991

Preparation and properties of a lysozyme derivative in which two domains are cross-linked intramolecularly between Trp62 and Asp101.

A lysozyme derivative in which two domains were cross-linked intramolecularly was newly prepared by means of a two-step reaction. First, the beta-carboxyl group of Asp101 in lysozyme was selectively modified with 2-(2-pyridyldithio)ethylamine in the presence of 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide hydrochloride. After reduction of the pyridyldithio moiety of Asp101 modified lysozyme at pH 4.5 with dithiothreitol, the derivative was allowed to cross-link intramolecularly by reaction with 1,3-dichloroacetone at pH 7. Intramolecularly cross-linked lysozyme thus formed was purified by gel chromatography followed by ion-exchange chromatography. Based on the results of 1H-NMR and peptide analyses, it was concluded that Asp101 was cross-linked to Trp62 with a -CH2COCH2SCH2CH2NH-bridge in this derivative. The derivative showed minor but distinct activity against Micrococcus lysodeikticus and glycol chitin. Its melting temperature for thermal denaturation was higher by 7.3 degrees than that of native lysozyme at pH 3.

Amino Acid Sequence↗

PubMed1991

Renal tubular actions of ANF.

Many of the earliest investigations of the renal effects of atrial natriuretic factor (ANF) pointed to the glomerulus as a major site of the peptide's action. More recently, there have been many reports showing various effects of ANF on renal tubular epithelia, including collecting ducts, thick ascending limbs of Henle's loop, thin limbs of Henle's loops, and proximal tubules. The purpose of this review is to summarize the evidence for renal tubular actions of ANF and analyze it from the perspective of the specialized functions of the individual nephron segments, addressing the question: can renal tubule effects of ANF play a significant role in the precise day-to-day regulation of renal NaCl and water excretion? Based on these considerations, we propose that long-term renal tubular action of ANF may be distinct from its short-term natriuretic effect. The short-term action of ANF to accelerate salt and water excretion may play a role in the overall response to acute volume overload. This action of ANF appears to be largely due to an ANF-mediated increase in glomerular filtration rate accompanied by a blunting of the tubuloglomerular feedback mechanism, perhaps with some contribution from ANF-mediated inhibition of fluid absorption in the proximal tubule. In contrast, contributions of ANF to the precise day-to-day regulation of salt and water excretion are likely to be chiefly due to ANF-mediated inhibition of NaCl and water absorption in collecting ducts, but may also involve actions of ANF on the loop of Henle.

Animals↗

PubMed1991

Regulation of collecting duct water permeability independent of cAMP-mediated AVP response.

We have used the isolated perfused tubule technique, measurements of adenosine 3',5'-cyclic monophosphate (cAMP) content in single tubules, and freeze-fracture electron microscopy to study the basis of high vasopressin-independent (basal) osmotic water permeability (Pf) in the terminal inner medullary collecting duct (IMCD) of the rat. The results confirmed the observation that the basal Pf of the terminal IMCD is considerably higher than that of the initial IMCD. They also showed that the basal Pf of the terminal IMCD is regulated by in vivo factors related to water intake, such that a very high vasopressin-independent Pf can be induced in isolated tubules by prior in vivo thirsting. Tubules from thirsted rats did not display elevated urea permeabilities, nor did they exhibit measurable cAMP levels in the absence of exogenous vasopressin, indicating that the high basal Pf was not due to residual binding of vasopressin to its receptors. Freeze-fracture studies in thirsted rats demonstrated the presence of intramembrane particle (IMP) clusters in both initial and terminal IMCD, with more in the latter. Water loading of the rats suppressed the incidence of clusters almost entirely but did not fully suppress the basal Pf in the terminal IMCD, raising the possibility that a component of transepithelial water transport may occur independently of the vasopressin-regulated IMP clusters. On the basis of these results, we conclude that the vasopressin-independent Pf in the terminal IMCD can be stably elevated to very high levels in response to in vivo thirsting. This elevation appears to be due to a chronic conditioning effect mediated by unknown in vivo factors and is not due to the short-term cAMP-mediated regulatory effect of vasopressin.

Animals↗

PubMed1991

RT-PCR microlocalization of mRNA for guanylyl cyclase-coupled ANF receptor in rat kidney.

Microlocalization of mRNA coding for the guanylyl cyclase-coupled atrial natriuretic factor (ANF) receptor was carried out in the rat kidney. We used a combination of reverse transcription and polymerase chain reaction (RT-PCR) in individual microdissected renal tubule segments, glomeruli, and vasa recta bundles. Relative quantitation of the resulting amplified cDNA utilized densitometry of autoradiograms from Southern blots probed with a specific 32P-labeled probe. Among renal tubule segments, the largest signal was found in the terminal inner medullary collecting duct (IMCD). Slightly smaller signals were found in the initial IMCD and in loop of Henle segments from the inner medulla. Readily detectable signals were also seen in the following segments (in descending order): cortical collecting duct, proximal convoluted tubule, medullary thick ascending limb, cortical thick ascending limb, distal convoluted tubule, and outer medullary collecting duct. Large signals were also detected in glomeruli and in vasa recta bundles from the inner stripe of the outer medulla. Based on these results, we conclude that 1) renal microlocalization of specific mRNAs coding for hormone receptors is feasible through application of the RT-PCR procedure in microdissected renal tubules and vascular elements, and 2) the gene for the guanylyl cyclase-coupled ANF receptor is broadly expressed along the nephron, raising the possibility that multiple sites of ANF action are present.

Animals↗

PubMed1991

Palliation of left main bronchus compression due to malignant tumor by intubation via a tracheostomy tube.

Intubation of the left main bronchus via a tracheostomy tube was performed in a patient with local recurrence of lung cancer associated with invasion and obstruction of the left main bronchus after right sleeve pneumonectomy. The result was satisfactory not only for preventing asphyxia, but also for maintaining the patency of the airway after extubation of the endotracheal tube.

Bronchi↗

PubMed1991

[Surgical enucleation for renal cell carcinoma. A case report].

We present a case of bilateral synchronous renal cell carcinoma treated with surgical enucleation. Urological consultation was asked to evaluate masses of the kidneys, which were detected during a diagnostic imaging on a 58-year-old man with hepatic disorder. Excretory urograms showed definite bilateral upper pole renal masses. Bilateral selective renal angiograms disclosed neovascularity in the small masses. Surgical enucleation of the left renal tumor by a flank approach was performed. The surgical specimen being 3.5 by 2.5 by 2 cm (29 g) was pseudoencapsulated and was identified renal cell carcinoma of the clear cell type, grade 1. INF alpha, pathologically. Seven weeks after, a pseudoencapsulated tumor of 3 by 2.5 by 2 cm (16 g) in the right upper pole was removed by simple enucleation. The pathological diagnosis was renal cell carcinoma of clear cell type, grade 2, INF alpha. The patient is well without evidence of recurrent or any residual disease at 21 months after the second operation. Renal function remains with in normal limits (CCr 110 ml/min). Of our collected cases of bilateral synchronous renal carcinomas treated by bilateral conservative surgery, clinical data are available for 11. Including our case, a total of 12 cases are reviewed.

Carcinoma, Renal Cell↗