Biomedical subjects

Y Yamane

Publications and source records attributed to Y Yamane.

At least 19 recordsLinked to original sources

PubMed2006

The anatomical basis of complete atrioventricular block in cats with hypertrophic cardiomyopathy.

The cardiac conduction system was examined histologically in 13 feline cases of hypertrophic cardiomyopathy (HCM) with complete atrioventricular (AV) block. Marked degeneration and fibrous replacement of the AV conduction system were consistently observed in the combined regions of the branching portion of the AV bundle and the upper portion of the left bundle branch. These changes were associated with extensive fibrosis of the central fibrous body and endocardial and myocardial fibrosis in the upper border of the ventricular septum. Chondrometaplastic lesions or osseous lesions, or both, present in the base of the central fibrous body, compressed the underlying penetrating or branching (or both) portions of the AV bundle, causing apparent reduction of the conduction fibres. The pathological process and the nature and predilection sites of the lesions resembled those associated with ageing in human patients with complete AV block. It is possible that the pathological process in the cats was fundamentally related to the normal ageing phenomenon and may have been exacerbated by mechanical forces created by the cardiac hypertrophy associated with HCM.

Animals↗

PubMed2006

Surgical management of a double-chambered right ventricle and chylothorax in a Labrador retriever.

A 22-month-old, male Labrador retriever was presented with anorexia, dyspnoea, and fainting. The dog was diagnosed with a double-chambered right ventricle and tricuspid valve dysplasia using echocardiography and cardiac catheterisation. A marked bilateral pleural effusion was also present and chemical analysis of the fluid confirmed the diagnosis of chylothorax. Using echocardiography, a pressure gradient of 87.1 mmHg was found between the proximal and distal chambers of the double-chambered right ventricle. Initiation of cardiopulmonary bypass allowed the anomalous muscle bundle that divided the right ventricle into two chambers to be resected via a right ventriculotomy. The fainting completely resolved postoperatively, and this treatment seemed quite effective in the reduction of pressure overload ascribable to ejection disturbance. Because the tricuspid dysplasia was not corrected in the first operation, the postoperative chyle effusion was reduced but did not cease. A combination of thoracic duct ligation and passive pleuroperitoneal shunting was effective in the resolution of the chyle effusion.

Animals↗

PubMed2006

Surgical correction of ventricular septal defect with aortic regurgitation in a dog.

An 8-month-old entire Miniature Dachshund, weighing 4.2 kg, was presented for examination following delvelopment of a cough. Ventricular septal defect had been diagnosed tentatively in its infancy on the basis of a cardiac murmur detected by auscultation and echocardiography. Echocardiography using a B mode right parasternal long-axis view showed a defect at the atrioventricular junction and a thickened cusp of the aortic valve prolapsing into the defect. Colour-flow Doppler showed shunt blood flow across the defect at the level of the atrioventricular junction, from left to right. The sinus of Valsalva was dilated, with turbulent blood flow. Aortic regurgitation was also observed. Cardiac catheterisation studies confirmed the diagnosis of a supracristal ventricular septal defect with aortic regurgitation. Despite medication with digoxin, enalapril and aminophylin, started from the first admission, left ventricular internal dimensions gradually increased, and fractional shortening of the left ventricle gradually decreased. Surgery, with the aid of extracorporeal circulation, to close the ventricular septal defect, was performed 1 year after the initial examination. The aortic valve was left untreated. Postoperatively, the systolic murmur disappeared. Shunt flow from the left to the right ventricle was no longer observed on echocardiography, however there was still a small amount of aortic regurgitation during diastole visualised with colour-flow Doppler echocardiography. The prolapse of the cusp of the aortic valve on B-mode echocardiography was no longer observed and thickening of the cusp had not progressed. Left ventricular function measurement using M mode echocardiography showed a reduced left ventricular volume overload with reduced left ventricular internal dimensions and increased fractional shortening. The cough was relieved and no follow-up medication was scheduled. Early surgical closure of the ventricular septal defect improved the patient's condition and controlled prolapse and thickening of the aortic valve.

Animals↗

PubMed2005

Numerous nonclonal chromosomal aberrations arising in residual recipient hematopoietic cells following allogeneic bone marrow transplantation.

A young female patient in a second remission of acute lymphoblastic leukemia underwent bone marrow transplantation after total body irradiation and high-dose cytarabine from her HLA-matched brother. Following successful engraftment, mixed chimerism was seen 75 days post transplant. The karyotype contained numerous abnormalities in residual recipient cells. Chromosomes 1, 7, 13, and X were significantly more affected than other chromosomes. The high-frequency breakpoints identified were 1p22.2, 5q31.2, and 13q14.2. Some karyotypes specific for leukemia, such as t(9;22)(q34.1;q11.2) and t(8;21)(q22.2;q22.2), not seen with the original disease, were also present. As the frequency of aberrant chromosomes increased markedly with time, donor leukocytes were infused 14 months after BMT, which effectively eradicated the abnormal karyotypes.

Bone Marrow Cells↗

PubMed2004

Overweight Japanese with body mass indexes of 23.0-24.9 have higher risks for obesity-associated disorders: a comparison of Japanese and Mongolians.

OBJECTIVE: The degree of obesity of Asians is less than that of Caucasians. It has been suggested that Japanese, categorized as having normal weight (BMI<25.0), as defined by WHO (2000), have a tendency toward increased incidences of dyslipidemia and diabetes. Our objective was to analyze parameters constituting obesity-associated disorders in overweight Japanese and Mongolians with a body mass index (BMI) of 23.0-24.9, and to assess the suitability for Asians of the Regional Office for Western Pacific Region of WHO criteria pertaining to obesity (WPRO criteria, 2000). DESIGN: Cross-sectional study in a workplace setting. SUBJECTS: A total of 386 Japanese men and 363 Japanese women, and 102 Mongolian men and 155 Mongolian women. MEASUREMENTS: Anthropometric measurements (weight, height, waist circumference, hip circumference and blood pressure) and metabolic measurements (plasma levels of total cholesterol, HDL cholesterol, triglyceride, glucose and insulin). RESULTS: Graded increases in BMI of Japanese and Mongolians were positively associated with body fat percent, waist circumference, hip circumference and waist/hip ratio. The Japanese were categorized as 22% overweight, 22% obese I, 3% obese II; the Mongolians rated as 18% overweight, 34% obese I, 19% obese II, based on the WPRO BMI criteria. The Mongolians had a higher prevalence of obesity and a higher body fat percent, but a lesser gradation of dyslipidemia, than did the BMI-matched Japanese groups. Overweight Japanese (BMI 23.0-24.9), in comparison to normal Japanese (BMI 18.5-22.9), had significant differences in systolic blood pressure, HDL-cholesterol and triglyceride in men, and in systolic and diastolic blood pressure, HDL-cholesterol, triglyceride, insulin and Homoeostasis model assessment-insulin resistance in women. In contrast, the Mongolians showed no significant differences in metabolic parameters between overweight and normal subjects, except for diastolic blood pressure. CONCLUSION: Since the relationship between abdominal fat mass and BMI is ethnic-specific, a universal BMI cutoff point is inappropriate for Asian populations such as the Japanese and Mongolians. The present investigation suggests that, while the WPRO criteria are suitable for Japanese, the WHO criteria are more appropriate for Mongolians.

Adult↗

PubMed2004

Ethnic differences in the formation of small LDL particles in Asians: a comparison of Koreans, Japanese and Mongolians.

BACKGROUND: The presence of small, dense LDL particles has been recognized as an independent risk factor for coronary heart disease (CHD) but is not directly representative of CHD mortality rate beyond any given population. We investigated whether such inconsistency between three Asian ethnic groups might have arisen from anthropometric and metabolic factors. DESIGN: We conducted a cross-sectional survey among adult Koreans (412), Japanese (453) and Mongolians (253). RESULTS: The prevalence of small LDL particles was 36% in the Koreans, 21% in the Japanese and 7% in the Mongolians. Multiple logistic regression analysis revealed plasma triglyceride (TG) levels to be the strongest determinant of small LDL particle size in all three groups, with sex, HDL-cholesterol and non-HDL-C being other ethnic-specific significant determinants. Body mass index (BMI), FFA and insulin resistance were not significant factors in the regression analysis. Of the subjects with low TG levels (< 133 mg dL(-1)), 25% of the Koreans and 10% of the Japanese, but no Mongolians, had small LDL particles. CONCLUSIONS: Results of the present study suggest that traditionally, high-carbohydrate diets in Korea and Japan possibly contribute to higher TG-levels compared with BMI-matched Mongolians, and to the formation of small LDL particles, even in instances of low TG levels.

Adult↗

PubMed2004

[In what case can we abbreviate mediastinal lymph nodes dissection of peripheral small-sized lung cancer?].

UNLABELLED: We analyzed 723 cases of non small cell lung cancer (459 adenocarcinomas and 264 squamous cell carcinomas) from the view point of lymph nodes metastases, according to histological type, location of cancer and tumor size. METHOD: Histological type was adenocarcinoma or squamous cell carcinoma. Location was divided into 8 areas [right side; 4 areas, upper lobe (RUL)/middle lobe (RML)/S6 (RS6)/basal segment of lower lobe (RBS): left side; 4 areas, upper division of upper lobe (LUD)/lingula (LLS)/S6 (LS6)/Basal segment of lower lobe (LBS)]. Tumor size was divided by centimeters, namely 0.0-1.0 cm, 1.1-2.0 cm, 2.1-3.0 cm, etc.. RESULTS: Safety size of lung cancer in which we can abbreviate mediastinal lymph nodes dissection was as follows. In adenocarcinoma, in RUL/RML/RBS 1.0 cm, in RS6 2.0 cm, in LUD 1.0 cm, in LLS/LS6/LBS 2.0 cm. In squamous cell carcinoma, in RUL 1.0 cm, in RML/RS6/RBS 2.0 cm, in LUD 1.0 cm, in LLS/LS6/LBS 2.0 cm. CONCLUSION: In 1.0 cm or smaller non small cell lung cancer we might abbreviate mediastinal lymph nodes dissection. Moreover, in squamous cell carcinoma of (RML, LLS, right or left lower lobe) of 2.0 cm or smaller size, we might abbreviate mediastinal lymph nodes dissection.

Adenocarcinoma↗

PubMed2003

Cardiac myxoma of the tricuspid valve in a dog.

A case of cardiac myxoma arising from the tricuspid valve is described in an 8-year-old dog that had suffered intermittent episodes of syncope. At surgical operation, a large, irregular, gelatinous mass was found attached to the septal leaflet of the tricuspid valve. The excised tumour, measuring 5x4x3.5 cm, had a grey-to-yellow, friable, mucoid, multilobulated and polypoid appearance, with focal haemorrhage. Histologically, the tumour consisted of a hypocellular mass of a myxoid matrix, rich in acid mucopolysaccharides, with a supporting structure of spindle-like, elongated or stellate cells scattered in an abundant stroma. The surface of the mass was covered by a single layer of endothelial-like cells. Immunohistochemistry revealed that the surface cells of the mass were positive for the endothelial marker CD34 and the constituent cells within the mass reacted positively and uniformly with antibodies to vimentin and alpha-smooth muscle actin. The dog died 36 h after the operation and, at necropsy, wide dissemination of myxomatous embolization to the intrapulmonary arteries was found.

Actins↗

PubMed2003

Difficulty in losing weight by behavioral intervention for women with Trp64Arg polymorphism of the beta3-adrenergic receptor gene.

OBJECTIVE: Trp64Arg mutation in the beta(3)-adrenergic receptor (beta(3)AR) gene is relatively common in Japanese people. However, it has not been clear whether persons with Trp64Arg mutation in the beta(3)AR gene tend to have obesity and difficulty in losing weight even with a restricted diet and exercise. We investigated the response of body weight and metabolic factors to behavioral intervention in Japanese women with Trp64Arg mutation in the beta(3)AR gene. DESIGN: A 3-month behavioral intervention study using a combination of diet and exercise programs. SUBJECTS: A total of 76 perimenopausal women with no clinical symptoms (age: 54.7+/-7.7 y, body mass index (BMI): 21.0-33.0 kg/m(2)). MEASUREMENTS: Anthropometric measurements (weight, height, body fat, waist circumference, hip circumference, skin fold, resting energy expenditure and blood pressure) and metabolic measurements (serum levels of cholesterol, triglyceride, phospholipid, nonesterified fatty acid, glucose, insulin and leptin) and determination of the beta(3)AR genotype by polymerase chain reaction followed by BstNI digestion. RESULTS: At the baseline of BMI, body weight, body fat, waist circumference, hip circumference, the arm skin fold, resting energy expenditure, or blood lipid and glucose profiles, there was no significant difference in participants with/without mutation of the beta(3)AR gene. The intervention yielded a body weight reduction in 69 and 48%, and induced a significant difference in weight loss (-0.74 and -0.01 kg) for women with wild-type and Trp64Arg mutation, respectively. Significant differences of anthropometric parameters were found in body weight, BMI, waist and hip circumferences and blood pressure of wild type by the intervention. However, women with Trp64Arg mutation did not show significant changes in these anthropometric parameters, except for hip circumference. A significant difference was found in high-density lipoprotein cholesterol (HDL-C) and in the low-density lipoprotein cholesterol/HDL-C ratio in both genotypes. CONCLUSION: The results of the present study suggest that the Trp64Arg mutation of the beta(3)AR gene is associated with difficulty in losing weight through behavioral intervention, although it is not related to obesity-related phenotypes and resting energy expenditure before the intervention.

Adult↗

PubMed2003

Feasibility study using a new small electronic pancreatoscope: description of findings in chronic pancreatitis.

BACKGROUND AND STUDY AIMS: Numerous images characteristic of chronic pancreatitis have been obtained with fiberoptic peroral pancreatoscopy systems. However, the resolution of these images is inferior to that obtained with peroral electronic pancreatoscopy (PEPS). Clearer images of the pancreatic duct with chronic pancreatitis have now been documented, in some cases using PEPS alone. The significance of this finding is reported here. PATIENTS AND METHODS: A total of 42 PEPS procedures were carried out in 36 patients with chronic pancreatitis, without sphincterotomy or balloon dilation of the papilla of Vater. Using endoscopic retrograde pancreatography, the patients were classified as having equivocal (n=5), mild (n=5), moderate (n=15), or marked (n=11) degrees of chronic pancreatitis. The insertion rate with PEPS was 90 % (38 of 42 procedures), and it was ultimately possible to examine five, three, 13, and 11 patients in each group, respectively. RESULTS: Images of turbid pancreatic juice, protein plugs of various shapes, pancreatic calculi, indistinct vascular markings, whitish mucosa, local redness, scattered redness, disappearance of the fold, deformation of the fold, irregularly dilated lumen, and stenosis were found to be characteristic of chronic pancreatitis. These images were obtained using PEPS. CONCLUSIONS: PEPS proved to be a feasible new technique for diagnosing chronic pancreatitis, and it was able to detect abnormal findings more clearly than other imaging methods.

Aged↗

PubMed2003

Surgical correction of cor triatriatum dexter in a dog under extracorporeal circulation.

A shiba inu dog with marked abdominal distension was diagnosed with cor triatriatum dexter and surgical correction was performed under extracorporeal circulation. The total duration of cardiac arrest was 11 minutes and total perfusion time was 34 minutes. The dog had an uneventful postoperative recovery. Postoperative contrast radiography of the caudal vena cava revealed normal flow into the right heart. Abdominal distension was no longer observed. Although several methods have been used to treat cor triatriatum dexter in dogs, the authors consider surgical correction under extracorporeal circulation to be a reliable approach.

Animals↗

PubMed2002

GAP junctional channel inhibition alters actin organization and calcium propagation in rat cultured astrocytes.

Astrocytes are connected by gap junctions, which provide intercellular pathways that allow a direct exchange of ions and small metabolites including second messengers and the propagation of electric currents. The roles of gap junctional communication on whole-cell morphology, cytoskeletal organization, and intercellular communication in astrocytes are not yet clear even in vitro, though there are many studies that have examined the active relation between gap junctions and actin filaments in astrocytes. Here we examined the effects of gap junction inhibitors, which do not interrupt the formation but rather the function of gap junctions, on whole-cell morphology, cytoskeletal organization, and intercellular communication in rat cultured astrocytes. Functional blockade of gap junctions during the formation of an astrocytic monolayer resulted in discordance of actin stress fibers between neighboring cells, even though whole-cell morphology of these cells did not change by such treatment. Mechanical stimulation-induced calcium wave propagation was significantly reduced in these actin-discordance cells even after thorough wash out. Differentiation of astrocytes in the presence of gap junction inhibitors was associated with morphological disarrangement among neighboring cells due to disordered alignment of actin stress fibers between cells.Our results indicate that gap junctional communication enables cell-to-cell coordination of actin stress fibers in astrocytes, thus enhancing intercellular communication through calcium spread.

Actins↗

PubMed2002

[Pleomorphic adenoma of the lung; report of a case].

A 67-year-old woman was admitted because of an abnormal shadow on the chest X-ray film. Chest computed tomography (CT) film revealed a peripheral mass in the middle lower lobe of the lung. We performed open lung biopsy and diagnosed as a benign epithelial adenoma but not ruled out adenocarcinoma completely by intraoperative examination of frozen sections. We operated right middle lobectomy and mediastinal lymph nodes dissections. Histological examination confirmed pleomorphic adenoma. We examined salivary glands, but didn't find the focus of that. The patient had been well for three years postoperatively.

Adenoma, Pleomorphic↗

PubMed2001

2-Acylimino-3H-thiazoline derivatives: a novel template for platelet GPIIb/IIIa receptor antagonists.

In the course of our research for the low-molecular weight RGD peptide mimics, we have found that a rigid 2-acylimino-3H-thiazoline structure is suitable for the peptide backbone mimics. Introduction of amidinophenyl and beta-alanine moiety as arginine and aspartic acid side-chain surrogates to this backbone mimic resulted in a highly potent fibrinogen receptor antagonist 2-(4-amidinobenzoylimino)-3,4-dimethyl-N-(2-carboxyethyl)-3H-thiazoline-5-carboxamide (7c), namely PS-028 (Ki = 46.5 +/- 5.8 microM).

Animals↗

PubMed2001

[18F] labeled diacylglycerol analogue as a potential agent to trace myocardial phosphoinositide metabolism.

Phosphoinositide metabolism plays an important role in cardiac pathophysiology. To investigate whether [18F]diacylglycerol could be used to trace myocardial phosphoinositide metabolism, lipids were extracted from rat myocardium after the injection. 1-[8-[18F]fluorooctanoyl]-2-palmitoylglycerol and 1-[8-[18F]fluoropalmitoyl]-2-palmitoylglycerol were predominantly metabolized to phosphatidylethanolamine and triacylglycerol, respectively. The radioactivity incorporated into phosphoinositide metabolism was 51, 44, 32, and 30% 3, 5, 10, and 30 minutes after the injection of 1-[4-[18F]fluorobutyryl]-2-palmitoylglycerol, respectively. 1-[4-[18F]fluorobutyryl]-2-palmitoylglycerol might be a potential tracer to evaluate myocardial phosphoinositide metabolism early after the injection.

Animals↗

PubMed2001

Complex objects are represented in macaque inferotemporal cortex by the combination of feature columns.

Intrinsic signal imaging from inferotemporal (IT) cortex, a visual area essential for object perception and recognition, revealed that visually presented objects activated patches in a distributed manner. When visual features of these objects were partially removed, the simplified stimuli activated only a subset of the patches elicited by the originals. This result, in conjunction with extracellular recording, suggests that an object is represented by a combination of cortical columns, each of which represents a visual feature (feature column). Simplification of an object occasionally caused the appearance of columns that were not active when viewing the more complex form. Thus, not all the columns related to a particular feature were necessarily activated by the original objects. Taken together, these results suggest that objects may be represented not only by simply combining feature columns but also by using a variety of combinations of active and inactive columns for individual features.

Action Potentials↗

PubMed2001

Introduction of tissue engineering concepts into the field of endovascular grafts: an attempt to solve endoleakage problems of endovascular grafts implanted in aortic aneurysms.

To solve endoleakage problems of endovascular prostheses inserted in aortic aneurysms, a concept originating from tissue engineering was proposed. We proposed that in order to accelerate the thrombus inside the aneurysm, three major factors for successful tissue engineering, i.e., appropriate cells, extracellular matrices, and growth factors, should be introduced into a space between the endovascular grafts and the aneurysm. As a simulation model in animals, two kinds of fabric vascular prostheses were used. One was a small graft used as an endovascular graft and another was a large graft as an envelope for the small graft, used as the aneurysm wall. Adipose tissue fragments with fresh blood coagula were injected between the two grafts. The control was a preparation without tissue fragments. Two months and a half after surgery, the test group showed complete connective tissue formation in the space between the two grafts, but in the control, brownish thrombus remained. From this experiment, we speculated that tissue fragment transplantation will accelerate connective tissue formation of the thrombus, and this complete organization of the thrombus might reduce endoleakage.

Adipose Tissue↗

PubMed2001

Outer dense fiber 2 is a widespread centrosome scaffold component preferentially associated with mother centrioles: its identification from isolated centrosomes.

Because centrosomes were enriched in the bile canaliculi fraction from the chicken liver through their association with apical membranes, we developed a procedure for isolation of centrosomes from this fraction. With the use of the centrosomes, we generated centrosome-specific monoclonal antibodies. Three of the monoclonal antibodies recognized an antigen of ~90 kDa. Cloning of its cDNA identified this antigen as a chicken homologue of outer dense fiber 2 protein (Odf2), which was initially identified as a sperm outer dense fiber-specific component. Exogenously expressed and endogenous Odf2 were shown to be concentrated at the centrosomes in a microtubule-independent manner in various types of cells at both light and electron microscopic levels. Odf2 exhibited a cell cycle-dependent pattern of localization and was preferentially associated with the mother centrioles in G0/G1-phase. Toward G1/S-phase before centrosome duplication, it became detectable in both mother and daughter centrioles. In the isolated bile canaliculi and centrosomes, Odf2, in contrast to other centrosomal components, was highly resistant to KI extraction. These findings indicate that Odf2 is a widespread KI-insoluble scaffold component of the centrosome matrix, which may be involved in the maturation event of daughter centrioles.

Amino Acid Sequence↗