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Biomedical subjects

C Yutani

Publications and source records attributed to C Yutani.

At least 91 records · Page 5Linked to original sources
PubMed1996

Small cell carcinoma of the uterine cervix with syndrome of inappropriate antidiuretic hormone secretion.

In a 59-year-old woman suffering from the syndrome of inappropriate antidiuretic hormone secretion, a small cell carcinoma of the uterine cervix was detected. The tumor was immunoreactive for antidiuretic hormone as well as for neuron specific enolase, chromogranin A, and Leu-7, but not vimentin. Electron microscopic examination of the tumor revealed neurosecretory granules. To our knowledge, this is only the second report of the syndrome of inappropriate antidiuretic hormone secretion with small cell carcinoma of the uterine cervix and the first one confirmed immunohistopathologically.

CD57 Antigens↗
PubMed1996

Calcific degeneration of bioprosthetic aortic valves in patients receiving steroid therapy.

BACKGROUND AND AIMS OF THE STUDY: Calcification of glutaraldehyde-preserved bioprosthetic valves is a frequent long-term complication of valve replacement, although the mechanism responsible for such degeneration is not clearly understood. In the current study, we investigated the calcific degeneration of bioprosthetic aortic valves in patients who had been given steroid treatment for aortitis in order to evaluate the immune response to glutaraldehyde-preserved bioprostheses. METHODS: Ten patients who had undergone aortic valve replacement with bioprosthetic valves were studied. Their mean age was 48.4 years (range: 27 to 64 years). Aortitis was due to Takayasu disease in eight patients and to Behcet aortitis in two. The bioprosthetic valves used included bovine pericardial xenografts (n = 8) and porcine aortic valves (n = 2). The mean daily dosage of prednisone was 10.1 mg (range: 2.5 to 60 mg); mean duration of therapy was 8.0 years. The mean patient follow up, using echocardiography, was 11.5 years (range: 8.5 to 16 years). The total follow up period was 115 patient-years. RESULTS: During follow up, three reoperations were required because of valve detachment, aortic insufficiency due to perforation of the aortic cusp, and aortic insufficiency with coronary orifice stenosis, respectively. No reoperations were required for stenotic degeneration of the bioprosthetic valves. Seven bioprosthetic valves were still functioning between 8.5 and 16 years after implantation. Calcific degeneration in two of three bovine pericardial valves that required replacing was surprisingly minimal; separation of collagen fibers in the valves by infiltration with plasma proteins was also minimal. CONCLUSIONS: These results suggest that the calcific degeneration of bioprosthetic valves may be decreased by concomitant steroid therapy for aortitis, though further research will be required to confirm this effect and to determine the mechanism(s) involved.

Adult↗
PubMed1996

[Histopathological study of valvular deposits of amyloid protein in cardiac amyloidosis].

Cardiac amyloidosis is associated with amyloid deposits in cardiac valves which also show the thickening of leaflets and cusps. This study examined amyloid deposits on cardiac valves to investigate the possible involvement in echocardiographic valvular abnormalities in 17 patients with systemic amyloidosis (12 males and 5 females aged 44 to 82, mean 66.4 years) in the autopsy files of the National Cardiovascular Center between 1980 and 1993. All four cardiac valves were examined histologically using hematoxylin-eosin and Congo red stains with polarization. All cusps and leaflets were divided into six segments and all segments of each cusp and leaflet were scored for the proportional area of amyloid deposit (from 0 to 3). The immunohistochemical types of amyloid proteins were immunoglobulin light chain-related (AL) amyloidosis in 16 cases, and amyloid A-related (AA) amyloidosis in one case. Twelve of 16 cases with AL amyloidosis were subclassified as AL lambda type and 4 were subclassified as AL kappa type. In the atrioventricular valve leaflets, the atrial side of basal portion showed the most remarkable amyloid deposits among the six segments. In the semilunar valves, amyloid deposits were mild in the tip and middle portions. Among the patients with AL amyloidosis, those with AL lambda type amyloid appeared to have greater deposits than those with AL kappa type amyloid. Mitral valves appearing abnormal by echocardiography had greater amyloid deposits. However, considering other factors affecting valvular function, the relationship between the localization or the degree of amyloid deposition and endocardiographic valvular abnormalities was unclear.

Adult↗
PubMed1995

Assessment of coronary artery distensibility by intravascular ultrasound. Application of simultaneous measurements of luminal area and pressure.

BACKGROUND: Atherosclerotic change in the coronary artery is associated with an impaired vessel wall distensibility. However, there are few data regarding the relation between vessel wall morphology and distensibility. Therefore, with intravascular ultrasound, we assessed coronary artery distensibility in angiographically normal coronary segments of humans. METHODS AND RESULTS: Data were analyzed at 35 angiographically normal coronary sites where circumferential or noncircumferential lesions were demonstrated by ultrasound in 22 patients (mean age, 55 years). After intracoronary injection of 500 micrograms nitroglycerin (NTG), coronary luminal area was measured with intravascular ultrasound (30 MHz, 3.5F to 4.3F, 1800 rpm). Intracoronary pressure was simultaneously measured with a 2F micromanometer-tipped catheter located at the left main coronary artery. The coronary distensibility index was calculated as 10-fold the ratio of luminal area change to intracoronary pressure change during a cardiac cycle. Another pressure-independent vascular stiffness index, beta, was derived by the following formula: beta = [ln(SBP/DBP)]/(dD/diastolic mean diameter), where SBP is systolic intracoronary pressure, DBP is diastolic intracoronary pressure, and dD is the difference between systolic and diastolic diameters. At the sites where luminal areas were measured, thickness of intima-media complex, defined as the distance between the intimal leading edge and the adventitial leading edge, was determined as an index of the severity of atherosclerosis. In seven segments, distensibility index was determined before and after NTG injection to examine the effect of NTG on coronary distensibility. In all examined sites, including circumferential and noncircumferential lesions, the luminal area was 12.6 +/- 5.0 mm2 during systole and 11.6 +/- 4.6 mm2 during diastole, and the calculated coronary distensibility index ranged from 0 to 0.83 mm2/mm Hg. The thickness of the intima-media complex ranged from 0.12 to 1.30 mm, suggesting the presence of various grades of atherosclerosis even in the absence of angiographic lesions. There was a poor inverse correlation between thickness of the intima-media complex and distensibility index (r = .19, y = -0.17x + 0.41, P = .29). However, when noncircumferential lesions were excluded for evaluation, there was a significant inverse correlation between them (r = .58, y = -0.50x + 0.72, P < .01). Under these conditions, the thickness of the intima-media complex also correlated with the value of beta (X10(-1), which ranged from 0.28 to 3.99 (r = .70). After NTG injection, coronary distensibility increased by an average of 71% in the segments with a thin intima-media complex, whereas it did not substantially change in those with a relatively thick intima-media complex. CONCLUSIONS: These results suggest that coronary distensibility is impaired in the coronary sites accompanying occult atherosclerosis, none of which can be detected by the conventional angiography. NTG can augment coronary distensibility in the segments without a markedly thickened intima-media complex. We suggest that thickness of the intima-media complex can contribute to determining the coronary distensibility in clinical settings.

Adult↗
PubMed1995

Cytodiagnosis of parvovirus B19 infection from ascites fluid of hydrops fetalis: report of a case.

The cytologic changes in the smears of fetus ascites fluid with parvovirus B19 infections are described. Cytology revealed the ground-glass appearance of the nuclei having a perinuclear halo, and the nuclear chromatin was spread as a thin rim around the inclusion. Subsequently, monoclonal antibodies for parvovirus B19 were applied to identify the specific antigen in the Papanicolaou-destained specimens. Positive staining reaction products were found throughout the cytoplasm of cells. Similar phenomena were confirmed in paraffin-embedded tissue sections of many organs in autopsy materials. It is hoped that recognition of those virus-infected cells in the body cavity fluid of the fetus will be helpful in making a diagnosis of hydrops fetalis associated with parvovirus B19 infections of the pregnant woman.

Adult↗
PubMed1995

Histologic modification by cryopreservation in rat aortic allografts.

Histologic changes after the cryopreserved rat aortic transplantation were studied, and the influences of the cryopreservation and of the allografting on the histology were examined. Four groups of Brown Norway (RT1n) and Lewis rats (RT1(1)) were used (n = 4 at each examined period in each group): the cryopreservation-allograft group (from Brown Norway to Lewis with cryopreservation), the cryopreservation-isograft group (from Lewis to Lewis with cryopreservation), the fresh allograft group (from Brown Norway to Lewis without cryopreservation), and the fresh isograft group (from Lewis to Lewis without cryopreservation). The graft was harvested from a descending thoracic aorta of a donor rat, implanted to an infrarenal abdominal aorta of a recipient rat, and extracted at 10 days, 1, 3, 6, and 12 months after the operation. The intimal thickening, cellular loss in the media, and cellular infiltration in the adventitia were observed, which were the same phenomena seen in chronic rejection of human organ allografts. Although the degree of intimal thickening and cellular loss in the media were higher in the cryopreserved groups than in the fresh groups, the cryopreservation procedure suppressed cellular infiltration in the adventitia after allotransplantation. The immunologic attack against the graft might be diminished by cryopreservation.

Animals↗
PubMed1995

High prevalence of atrial fibrosis in patients with dilated cardiomyopathy.

OBJECTIVES: We examined the extent of fibrotic changes in the left atrium of cardiomyopathic human hearts and investigated the relation of mechanical overload caused by left ventricular dysfunction to fibrosis of the left atrium. BACKGROUND: Left atrial dysfunction in dilated cardiomyopathy may contribute to progression of heart failure. In contrast to fibrosis of the left ventricle, atrial fibrosis has not been extensively studied in cardiomyopathic hearts. METHODS: The extent of fibrosis in the left atrium and left ventricle was determined by an automatic image analyzer in 38 autopsied hearts obtained from 9 patients who died of noncardiac illness (control group), 16 patients with dilated cardiomyopathy, 6 patients with hypertrophic cardiomyopathy with features mimicking dilated cardiomyopathy and 7 patients with a previous myocardial infarction. Transverse sections were obtained at the upper margins of the foramen ovale and left auricle in the left atrium and the median level of the left ventricle. RESULTS: There were no significant differences in extent of left atrial dilation, left ventricular dysfunction or duration of illness among the three groups with cardiac disease. Percent area of left atrial fibrosis (mean +/- SD) was significantly greater in the specimens from patients with dilated cardiomyopathy (13.1 +/- 6.1%, p < 0.01) and hypertrophic cardiomyopathy mimicking dilated cardiomyopathy (26.5 +/- 9.5%, p < 0.01) than in those from patients with an old myocardial infarction (3.8 +/- 1.1%). Percent area of left ventricular fibrosis in hearts from patients with dilated cardiomyopathy (12.9 +/- 8.6%) was significantly smaller than that in hearts from patients with hypertrophic cardiomyopathy mimicking dilated cardiomyopathy (35.8 +/- 11.9%, p < 0.01) and a previous myocardial infarction (38.4 +/- 8.0%, p < 0.01). Percent area of atrial fibrosis was significantly correlated with left ventricular ejection fraction in the group with a previous myocardial infarction but not in the other groups. CONCLUSIONS: There was a high degree of fibrotic change in the left atrium in the groups with dilated cardiomyopathy and hypertrophic cardiomyopathy mimicking dilated cardiomyopathy. Our findings suggest that atrial fibrosis in these patients may not have been related to mechanical overload of the left atrium but to some other, still unknown mechanisms.

Adult↗
PubMed1995

A comprehensive characterization of lymphoepithelial cyst associated with the pancreas.

BACKGROUND: Lymphoepithelial cyst of the pancreas is a rare but distinctive cystic lesion lined by a mature, keratinizing squamous epithelium and surrounded by lymphoid tissue. METHODS: To gain more insights into this entity, we describe 5 examples of lymphoepithelial cyst of the pancreas (2 of which were briefly described before) and compare them with similar cases in the literature for a total of 19 cases. RESULTS: The male:female ratio was 16:3; patients' ages ranged from 32 to 73 years (mean and median 51). The lymphoepithelial cyst was incidentally found at autopsy in 4 patients (21%) or during evaluation for unrelated diseases in another 4 patients (21%). In the remaining 11 patients, the cyst was associated with abdominal pain in 9 (47% of all patients), nausea/vomiting in 3 (16%), diarrhea in 1 (5%), and nonspecific systemic symptoms in 6 (32%) (some patients had more than 1 associated symptom). Computed axial tomography scan, with or without ultrasonographic study, was done in 16 cases and uniformly displayed a single, well-circumscribed, cystic mass protruding beyond the surface of the pancreas; the rest of the pancreas was normal. Intraoperatively, the cyst was readily apparent once the lesser sac was entered and the surface of the pancreas exposed; the cyst was located at the head (3 cases), neck (1 case), body (6 cases), and tail (9 cases). Surgery was done for all 15 clinical cases and included local excision of the cyst with a thin rim of attached, underlying pancreas (6 cases), or distal pancreatectomy with (4 cases) or without (3 cases) splenectomy. Follow-up information, available in 7 cases, showed that all symptoms disappeared and the patients were alive and well up to 6 years after surgery. CONCLUSIONS: This rare cyst of the pancreas has a uniform and characteristic clinicopathologic profile, enabling easy and accurate diagnosis. Although the histogenesis of lymphoepithelial cysts is not known, they are benign and can be cured by local excision.

Adult↗
PubMed1995

Immunohistochemical localization of C-reactive protein-binding sites in human atherosclerotic aortic lesions by a modified streptavidin-biotin-staining method.

One-step fluorescein-conjugated polyclonal antibody technique has shown that C-reactive protein (CRP) was located only extracellularly in human atherosclerotic lesions. In this report a more sensitive streptavidin-biotin technique was applied to detect the localization of CRP in human atherosclerotic lesions. Immunohistochemical staining with polyclonal and monoclonal anti-human CRP antibodies both produced a brown color extracellularly in the necrotic lesions, and intracellularly in CD68+ foam cells. The latter suggests an uptake of CRP-lipid complexes by macrophages. The staining is human CRP-specific because it was eliminated by preabsorption of the monoclonal antibody with pure human CRP, or by substitution of the primary antibody with non-immune rabbit serum. By overlaid CRP-binding study, a positive stain was observed on intimal smooth muscle cells and foam cells, suggesting that they have CRP-binding sites unless the CRP-binding activity was generated de novo through the fixation procedure. Accordingly, it is hypothesized that CRP may facilitate the uptake of lipids by macrophages accumulating in atherosclerotic lesions. Further, CRP might participate in cytolysis, which enlarges the necrotic area, and/or in phagocytosis that scavenges the necrotic tissue.

Actins↗
PubMed1995

Characterization of serum amyloid P component from human aortic atherosclerotic lesions.

Serum amyloid P component (SAP) is a glycoprotein in human plasma. We recently showed the localization of SAP in human atherosclerotic lesions by immunohistochemical staining. In this study, the presence of SAP in atherosclerotic lesions was confirmed, and the biochemical character of SAP in atherosclerotic intima was investigated and compared with that of native SAP. Atherosclerotic intima was sequentially extracted with 2 mmol/L CaCl2-Tris-buffered saline (TBS), 10 mmol/L EDTA-TBS, 3 mol/L guanidine-TBS, and collagenase digestion. The character of SAP in each extract was studied with double immunodiffusion, electroimmunoassay, crossed immunoelectrophoresis, and Western immunoblotting. The total amount of SAP in atherosclerotic intima was 190 +/- 64 micrograms/g wet tissue with an SAP-albumin ratio of 1:22.7, which is 44 times higher than the relative plasma ratio of 1:1000. This suggests that SAP is specifically localized in atherosclerotic lesions. SAP from the intima was indistinguishable from plasma or purified SAP with respect to immunological character and molecular weight. However, electrophoretic mobility and the binding of SAP to atherosclerotic intima appeared heterogeneous. Of total extractable SAP, about 43% appeared in the CaCl2-TBS fraction, 25% in the EDTA-TBS fraction, and 32% in the collagenase digestion fraction. SAP is one of the two pentraxins in human plasma; the other is C-reactive protein, which has also been reported to locate in atherosclerotic lesions. Our findings suggest a role for SAP in atherogenesis and encourage efforts to determine more precisely the physiological contributions of the pentraxin family to the development of atherosclerosis.

Aged↗
PubMed1995

Alterations of bone matrix protein mRNA expression in rat aorta in vitro.

We examined the expression of matrix Gla protein (MGP), osteopontin (OPN), and osteonectin (ON) mRNAs in aortic rings excised from 3-month-, 10-month-, and 2-week-old rats during 72-hour incubations in serum-free media. In the aortic rings from 3-month-old rats, the expression of MGP mRNA was strong before incubation and increased during the 72-hour incubation. The expression of OPN mRNA was first detected after a 5-hour incubation and increased thereafter, and that of ON mRNA was strong before the incubation and decreased during the incubation. The expression of MGP and OPN mRNAs in 10-month- and 2-week-old rats was similar to that in 3-month-old rats. In contrast, expression of ON mRNA in 10-month-old rats and the expression of ON mRNA in 2-week-old rats was stronger than that in 3-month-old rats at every incubation period. In situ hybridization and immunohistochemistry identified the MGP, OPN, and ON mRNA-expressing cells as vascular smooth muscle cells. These results suggest that the expression of these mRNAs was regulated in incubation time-dependent and age-specific ways. We believe that this organ culture model is useful for further studies of the function of these bone matrix proteins and regulation of their expression in the vessel wall.

Animals↗
PubMed1995

Pulmonary thromboembolic hypertension in systemic lupus erythematosus with lupus anticoagulant: histopathological analysis of localization and distribution of thromboemboli in pulmonary vasculature.

We report a systemic lupus erythematosus patient with lupus anticoagulant accompanied by pulmonary thromboembolic hypertension possibly due to large vegetation of the tricuspid valve of the heart. Histopathological analysis of localization and distribution of thromboemboli in pulmonary vasculature revealed that the organized thromboembolic occlusion of multiple blood vessels (99 out of 222 arteries), might be responsible for the pulmonary hypertension both in quality and quantity. The contribution of lupus anticoagulant to the pathogenesis of Libman-Sacks endocarditis in systemic lupus erythematosus, and its possible relationship to pulmonary thromboembolic hypertension are discussed.

Adult↗
PubMed1995

Arteriovenous fistula around the ventriculoperitoneal shunt system in a patient with a dural arteriovenous malformation of the posterior fossa. Case report.

A dural arteriovenous malformation (AVM) of the posterior fossa can produce persistent tinnitus, convulsions, and dementia. Successful therapeutic embolization may result in a complete cure, but in some cases, patients do not respond to the treatment. The authors report a patient with a dural AVM of the posterior fossa that did not respond to repeated intravascular treatments, but resulted in an arteriovenous shunt in the scalp around the ventriculoperitoneal shunt system. Although several hypotheses have been proposed on the pathogenesis of dural AVMs, the underlying mechanisms remain unknown. The rare complication we encountered may shed some light on the pathogenesis of dural AVMs.

Arteriovenous Fistula↗
PubMed1995

Histological change in cryopreserved rat aortic allograft.

In this study, we established an experimental cryopreserved aortic allograft model in rats and examined the long-term histological changes in the allograft. The thoracic aorta of Brown Norway rats (RT1n) was cryopreserved with 10% dimethylsulfoxide using a programmable freezer, and was allo-transplanted to the infrarenal abdominal aorta of Lewis rats (RT1l). Neither immunosuppressants nor anticoagulants were administered postoperatively. As a control, isografting was also performed between Lewis donor and recipient rats. In the allograft groups, cellular infiltration in the adventitia was massive at the acute phase after the operation and decreased gradually. Intimal thickening was predominantly observed from the early stage, followed by advancing thickening. In the media, decrease in cell number was detected after 1 month, and chondrocyte-like-cells were observed around which calcification was noted. Endothelial cells were observed in only one-third of the recipient investigated at 10 days and in over 80% of those at 12 months. In the isograft groups, a low grade of intimal thickening was detected over the experimental period. No decrease in cell number in the media was detected, and the degree of cellular infiltration in the adventitia was mild. After allotransplantation of the cryopreserved rat aorta, intimal thickening, medial necrosis and cellular infiltration in the adventitia, all the manifestations of rejection, occurred. Thus, as the cryopreserved tissue induces an immunological response, it is important to match the blood type and/or histocompatibility in clinical use.

Animals↗
PubMed1995

[Surgical treatment of mycotic coronary artery aneurysm associated with infective endocarditis: a case report].

53-year-old male was introduced our hospital for treatment of his infective endocarditis and congestive heart failure. Further evaluation revealed massive destruction of the mitral valve and aneurysm of the right coronary artery. We carried out an operation of aneurysmectomy and CABG with RGEA for coronary artery, and MVR using 29 mm SJM valve. Postoperative course was excellent. Graftgram showed good patency and perfusion of RGEA. Pathological findings were 1) macrophage infiltration into thrombi, 2) disappearance of elastic fibers of the media. 3) least atherosclerosis of the intima. We concluded that it was a mycotic coronary artery aneurysm. There have been no report of surgical treatment of such a mycotic coronary artery aneurysm upon our investigation.

Aneurysm, Infected↗
PubMed1994

Mechanisms of cerebral artery thrombosis: a histopathological analysis on eight necropsy cases.

The mechanisms of thrombus formation in atherosclerotic cerebral arteries are still controversial, although intraplaque haemorrhage and rupture of the atheromatous plaques have been proposed. A histopathological analysis of segments of the thrombosed large intracranial arteries was carried out on eight patients who died within 28 days after brain infarction. The study revealed occlusive thrombi in six and mural thrombi in two, developing mostly at the site of greatest stenosis or just distal to it. The histological characteristics of the thrombosed arteries were plaque rupture in three, intramural haemorrhage in one, ulceration in one, and thrombosis in the absence of plaque rupture or intramural haemorrhage in three. Occlusive emboli distal to the site of cerebral artery thrombosis (intracranial artery-to-artery thromboembolism) were observed in two. The following conclusions were drawn from the study: 1) plaque rupture or intraplaque haemorrhage is not a sine qua non for cerebral artery thrombosis; 2) occlusions occur at the site of greatest luminal compromise or just distal to it, and 3) non-occlusive mural thrombosis can occur in the absence of plaque rupture and eventually lead to local occlusion or distal embolisation.

Aged↗