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Biomedical subjects

K Yagyu

Publications and source records attributed to K Yagyu.

At least 55 records · Page 3Linked to original sources

Midterm results of the rotation-advancement flap method for correction of partial anomalous pulmonary venous drainage into the superior vena cava.

Since 1986, a rotation-advancement flap method has been used in 11 patients with partial anomalous pulmonary venous drainage into the superior vena cava. This method consists of atrial partitioning, enlargement of the superior vena cava, and protection of the sinus node. The midterm postoperative sinus node function and hemodynamic changes were examined in this study. Postoperative angiograms showed normal pulmonary venous pathway and no stenosis in the superior vena cava. Cardiac rhythm was normal and no clinical symptoms appeared.

Adult↗

Chronic effect of aluminium ingestion on bone in calcium-deficient rats.

In order to elucidate the relationship of osteogenesis with aluminum and iron deposition, we investigated the histopathological findings of bone in calcium and/or aluminium-deficient rats, together with levels of calcium, aluminium and iron in sera and bone tissues, and also the level of serum parathyroid hormone. Four week old male STD-Wistar rats were divided into four groups to examine the effects of four kinds of diets for ten weeks. The rats on normal diet (Group I) and normal diet+aluminum (Group II) did not show any pathological changes of the bones, but in both calcium-deficient diet group (Group III) and calcium deficient diet added aluminium (Group IV), the compact bone converted into spongy bone in varying degrees, particularly in Group IV. Aluminium deposition was demonstrated at the calcification fronts and the cement lines only in Group IV as red or violet-red lines with aluminium stain, together with iron deposition as revealed with Berlin blue stain, showing similar distribution pattern as aluminum. It was clearly indicated that aluminium and iron, instead of calcium, deposited on the calcification front of the bone under the condition of calcium deficiency, inhibiting the normal osteogenesis.

Aluminum↗

[A successful repair of aortic regurgitation and right ventricular aneurysm long after correction of tetralogy of Fallot].

Twenty-seven years after correction of tetralogy of Fallot, a 35-year-old man, suffered from dyspnea on effort and palpitations, underwent repair of aortic regurgitation and right ventricular aneurysm. Aortic regurgitation was due to a perforation at the base of the right coronary cusp, probably caused during the initial VSD patch closure, and it was repaired by suture. The right ventricular aneurysm was excised and the defect was closed directly. After operation, only slight aortic regurgitation was observed and premature ventricular contractions, presumably related to right ventricular aneurysm, were decreased markedly. His postoperative course has been uneventful and satisfactory for these 15 months.

Adult↗

[Successful redo-AVR with cryopreserved allograft for prosthetic valve endocarditis : report of a case].

A 20-year-old male undergoing mechanical aortic valve replacement suffered from prosthetic valve endocarditis by Coagulase negative Staphylococci 3 months postoperatively. Echocardiography revealed left ventricular distention, severe paravalvular leakage, valve detachment and large periannular abscess adjacent to the left main coronary artery. Redo-AVR was successfully performed with a cryopreserved aortic allograft by cylinder technique. The orifice of abscess was covered with the aortic wall of the graft. Postoperative echocardiography showed trivial central regurgitation and the abscess cavity went on vanishing. He discharged from hospital 2 months later without any symptom.

Abscess↗

Identification of two highly homologous presynaptic proteins distinctly localized at the dendritic and somatic synapses.

Through screening of a murine brain cDNA library, we have isolated two brain specific cDNAs encoding highly homologous proteins, named 921-L and 921-S, comprised of 134 amino acids with 80% identity. Immunohistological study with the mAbs raised against the bacterially expressed 921 proteins showed that 921-L protein is distributed at the dendritic region and 921-S at the neuronal somatic surface. Immuno-electron microscopic study revealed that both 921 proteins are localized at the presynaptic terminal, indicating that the 921 proteins are differentially expressed at the dendritic and somatic presynapses.

Adaptor Proteins, Vesicular Transport↗

Application of a new tactile sensor to thoracoscopic surgery: experimental and clinical study.

BACKGROUND: We developed a new tactile sensor that could quantify the hardness of objects as changes in the resonance frequency of the sensor (delta f). We have applied it to thoracoscopic operations for the localization of small invisible nodules in the lung. METHODS: When the sensor probe was moved over the lung surface, a delta f curve was depicted on the computer screen. When the sensor tip reached a point directly above a hard object, a sudden upward jump of the delta f curve was evoked. After experimental studies using pigs, the sensor was applied in 8 patients. More recently we produced a needle sensor to distinguish small nodules from bronchi that may evoke similar upward jumps of the delta f curve. Eight nodules and four bronchi in resected human lungs were probed directly using this sensor. RESULTS: In all of the patients, the hardness of various thoracic structures could be quantified. A total of 10 nodules were found using the sensor and resected thoracoscopically. The needle sensor distinguished nodules from bronchi, as the mean delta f of the bronchial walls (-64 +/- 45.9 Hz) was significantly higher than that of nodules (-526 +/- 168 Hz, p < 0.001). CONCLUSIONS: Thoracoscopic detection of small and invisible pulmonary nodules using our new tactile sensor is feasible.

Adenocarcinoma↗

The reeler gene-associated antigen on Cajal-Retzius neurons is a crucial molecule for laminar organization of cortical neurons.

In the neurological mutant mouse reeler, the histological organization of the neocortex develops abnormally and essentially results in an inversion of the relative positions of the cortical layers. The reeler mutation, therefore, provides an insight into the molecular mechanisms underlying the formation of the cortical layers. We have generated a monoclonal antibody (CR-50) that probes a distinct allelic antigen present in wild-type but not in reeler mutant mice. CR-50 reacted specifically with Cajal-Retzius neurons, one of the first cortical neurons to differentiate in the neocortex, but whose functional role is not known. When dissociated cerebral cortical cells were incubated with CR-50 in reaggregation culture, the genotype-dependent histogenetic assembly of wild-type cortical cells resembled that of reeler mutants. These findings revealed that the selective expression of a distinct molecule on Cajal-Retzius neurons is critical for the normal lamination of cortical neurons in the mammalian neocortex.

Animals↗

Changes in various tissues in the arterial wall of spontaneously hypertensive rats.

1. Using stroke-prone spontaneously hypertensive rats (SHRSP), stroke-resistant spontaneously hypertensive rats (SHRSR) and Wistar-Kyoto rats (WKY), vascular complications and the longevity of rats were investigated. 2. SHRSP aged more than 9.5 months tended to suffer from severe vascular complications such as periarteritis nodosa (PN) of mesenteric artery, while SHRSR very rarely showed severe vascular complications and WKY did not show any complications, because of the different level of systolic blood pressure. 3. Among some tissues PN tended to occur early in the small arteries of the testes and then in mesenteric artery, when these tissues of SHRSP were investigated microscopically. 4. Concerning the influence of systolic blood pressure on arterial smooth muscle layer, the deviation force of this layer was larger in SHRSR compared to WKY (44.7 times in Y axis), which was calculated mathematically and physically using computer analysis. 5. The arterial wall area of PN was enlarged, resulting in the low ratio of lumen/wall. The ratio of arterial lumen/wall was lower in SHRSP when compared to the age-matched WKY. 6. In search for myocardial ischaemia, ECG was recorded. There were positive correlations between PQ interval or SV1 + RV5 and age in the three strains of rats. ST depression more than 1 mm on ECG was most prevalent in old SHRSP, indicating probably the presence of myocardial ischaemia.

Animals↗

Long-term results of surgical treatment of intracardiac tumors. Effectiveness and limitation of surgical treatment.

Twenty-five cases of intracardiac tumors were operated upon from 1975 through 1994. Twenty-four operative survivors were followed up. The follow-up period ranged from 2 months to 19 years with an average of 8 years. The histological diagnoses of the tumors were as follows: benign tumors 21 (myxoma 20, leiomyoma 1) and malignant tumors 4 (sarcoma 3, carcinoma 1). In 21 cases, tumors had cardiac origins, while there were four intracardiac tumors which had originated in other organs and extended transvenously to the intracardiac cavity (leiomyoma 1, sarcoma 2, carcinoma 1). The results of surgical treatment of intracardiac benign tumors were satisfactory, regardless of their origins and multiplicity, both in the short-term and in the long-term. On the other hand, the long term results for malignant intracardiac tumors were extremely poor, although their excision or resection had a beneficial effect on the hemodynamics in patients with congestive heart failure or cardiogenic shock.

Adult↗

Elevation of cystathionine gamma-lyase activity in the serum of rats treated with a single dose of carbon tetrachloride.

Cystathionine gamma-lyase activity in the sera of rats subjected to experimental hepatotoxicity after intraperitoneal administration of carbon tetrachloride (CCl4) was measured and compared with activities of aspartate aminotransferase (GOT) and alanine aminotransferase (GPT), which have been clinically used for detecting liver damage. In the experimental subjects, serum levels of cystathionine gamma-lyase showed a similar behavior to GOT and GPT, increasing markedly with respect to the controls after administration of CCl4 and reaching a maximum at 24 hours. No such cystathionine gamma-lyase activity was detected immunochemically in the control subjects. These data suggest that measurement of serum cystathionine gamma-lyase activity could be used as a sensitive and specific marker of hepatic cytolysis.

Animals↗

[New tactile sensor for thoracoscopic detection of intrapulmonary nodules].

We have developed a new tactile sensor which can be used for thoracoscopic detection of invisible intrapulmonary nodules. We applied this new device for consecutive ten cases to excise twelve intrapulmonary nodules thoracoscopically from August 1994 to January 1995. In this report, one of ten cases was presented. The patient was a forty-three-year-old female and admitted with an indeterminate nodule on chest X-ray and computed tomography. When the sensor probe quantifying the hardness of objects by the changes in resonance frequency of the sensor (delta f) passed above the nodule, a sudden jump was evoked in delta f curve on the computer screen. The nodule was resected thoracoscopically and proved pathologically to be adenocarcinoma. Thoracoscopic procedure was then converted to open thoracotomy and lobectomy with lymph node dissection was performed.

Adenocarcinoma↗

[Mitral valve repair for mitral regurgitation].

UNLABELLED: In these 14 years, 54 adult patients, 28 males and 26 females, mean age 49.6 years old, underwent mitral valve repair for mitral regurgitation. Valve lesion consisted of 28 valve prolapse, 23 torn chordae, 4 ischemic lesion, 3 rheumatic changes, and 3 clefts. Valve prolapse near the commissure was repaired by Kay-Reed's annuloplasty in 31 patients. Torn chordae of the posterior leaflet was repaired by quadrangular resection of the leaflet in 21 cases. Commissural valve prolapse by torn chordae was treated by commissural resection and sliding repair of the leaflet in 5 patients. Torn chordae of the anterior leaflet was repaired by small triangular resection of the leaflet with artificial chordae using ePTFE suture or transfer of posterior chordae to the anterior leaflet in 6 cases. Ring annuloplasty was performed in 21 cases. Postoperative echocardiographic examination revealed no regurgitation in 41 patients, mild MR in 10, and moderate MR in 3. One patient died of arrhythmia early postoperatively. Another patient had cerebral infarction 10 months after the operation. No other complication or no late death was experienced. CONCLUSIONS: Early and late results of mitral valve repair for mitral regurgitation was satisfactory. Better long-term results will be expected by the improvement of surgical technique.

Adult↗

[The relationship between serum dehydroepiandrosterone sulfate levels and factors associated with cardiovascular diseases: a cross-sectional study in Japan].

To explore the relationship between serum DHEAS levels and blood pressure, obesity, smoking habits and drinking habits associated with onset of cardiovascular disease, we examined serum DHEAS levels in 90 males and 183 females, aged 35 to 62 years, who participated in a mass health examination conducted in a town of Aichi prefecture in 1992. The results were as follows. 1. Serum DHEAS levels were significantly higher in males than in females and decreased with age both sexes. 2. Age-adjusted serum DHEAS levels for both sexes decreased with blood pressure and BMI. 3. There were no apparent significance between age-adjusted serum DHEAS levels and smoking habits, whereas age-adjusted serum DHEAS levels were higher in groups of intake of ethanol volume 1-29 g/day than in the groups of intake of more than and less than ethanol volume 1-29 g/day. 4. Age-adjusted serum DHEAS levels were significantly decreased with the rise of sum of factors chosen as risk factor of cardiovascular disease disease in this study. It was suggested that serum DHEAS levels might be useful as an index of accumulation of risk factors of cardiovascular disease. Further studies should be performed to establish the possibilities as an index of genesis and prevention of cardiovascular disease.

Adult↗

[Pulsatile total cavopulmonary shunt for hypoplastic right heart syndrome with abnormal systemic venous return--a case report].

A pulsatile total cavopulmonary shunt was successfully performed on a 5-year-old girl with hypoplastic right heart syndrome associated with abnormal systemic venous return; at the same time, modified mitral valve replacement was performed for mitral regurgitation. The right atrium, tricuspid valve and right ventricle were all extremely dimunitive. The diameter of the tricuspid valve was 50% of normal and the volume of the right ventricle was 8.6% of normal. In addition, there were severe subpumonary stenosis, a restrictive ventricular septal defect (VSD) and an atrial septal defect (ASD). The bilateral superior venae cavae (SVCs) and the hepatic vein drained to the left atrium, and the inferior vena cava was infrahepatically interrupted with a hemiazygos connection to the left superior vena cava. At the operation, each SVC was anastomosed end-to-side to each branch of the pulmonary artery (PA). The restrictive ventricular septal defect and stenotic subpulmonary lesion were left. The diameter of the ASD was reduced from 12 mm to 7 mm. The main PA was neither divided nor banded. The pulsatile blood flow from the left heart to the PA was regurated by a native restrictive VSD and stenotic subpulmonary lesion, and that from the right heart via the ASD was limited by reducing the size of the ASD. These described anatomic arrangements produced adequate antegrade pulsatile flow in the PA, which might prevent the development of pulmonary arteriovenous fistulae and, besides permit transfer of drainage of the hepatic vein from the left to the right atrium via the ASD in future.

Arteriovenous Shunt, Surgical↗

[The left-sided atrioventricular replacement of corrected transposition of the great arteries through a left thoracotomy].

In a 17-year-old female with dextrocardia and corrected transposition of the great arteries, whose VSD and PFO had been surgically closed through median sternotomy two years previously, the left-sided atrioventricular valve replacement was performed for its severe insufficiency. The left anterolateral thoracotomy was chosen to have good visual field and to prevent unnecessary dissection of the adhesion. The postoperative course was uneventful.

Adolescent↗

[Thoracoscopic treatment of intrathoracic diseases].

Recently developed thoracoscopic surgical equipment and related instruments have enabled us to perform two groups of advanced thoracoscopic surgical procedures. Group 1: procedures formerly performed by open thoracotomy, and group 2: procedures performed by thoracoscopic surgery only. Group 1 includes bullectomy for spontaneous pneumothorax, wedge resection for lung nodules, resection of benign tumors of the mediastium or chest wall, lung lobectomy, and resection of giant bullae. Because thoracoscopic surgery is minimally invasive, intrathoracic surgical procedures should be performed by thoracoscopic surgery if the results are the same. Group 2 consists of surgery in patients with poor pulmonary reserve and laser ablation of the bullous lung in advanced emphysema. Until recently, surgical intervention was not an option in the patients in groups 2 because of the invasiveness of open thoracotomy. Thoracoscopic surgery allows resection of tumors in early stage lung cancer in patients with poor pulmonary reserve. Severely emphysematous lungs can be ablated with a laser and shrunk, to normalize pulmonary compliance, residual volume and total lung capacity, and thus relieve symptoms.

Humans↗