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C Yutani

Publications and source records attributed to C Yutani.

228 records · Page 13Linked to original sources
PubMedDate not supplied

Histological remodeling in an ovine heart failure model resembles human ischemic cardiomyopathy.

Staged coronary embolization, causing myocardial microinfarctions, has been shown in dogs and sheep to cause chronic ischemic heart failure (HF) that resembles the hemodynamics of the human condition. However, its histopathological basis remains unclear. We examined the hypothesis that the ventricular remodeling seen in such sheep resembles the histopathology of human ischemic cardiomyopathy (ICM). Understanding the pathophysiology of this model will determine its place in the development of treatment strategies for HF. Global left ventricular (LV) damage resulting in HF was induced by staged coronary embolization in 11 sheep. Six others served as controls (normal control, NC). In HF sheep, the heart was harvested 6 months after LV ejection fraction (EF) had stabilized at <35%. Histopathological profiles were compared in biventricular transverse sections at midpapillary level using computed image analysis. LV end-diastolic volume increased in the HF group from 84.9+/-29 to 122.4+/-30.3 ml (n=11, P<.05), but myocytes across the LV wall in noninfarcted zones decreased (435.7+/-38.2 NC; 297.8+/-48.4/unit area HF; n=11, P<.0001) as did myocyte nuclear density (990.5+/-51.5 NC; 677.5+/-121.1/mm(2) HF, n=11, P<.0001). In contrast, LV replacement and interstitial fibrosis increased as did myocyte diameter in noninfarcted zones: 0.1+/-0.1 to 6.2+/-4.5% (P=.0049); 2.0+/-1.0 to 7.6+/-4.9% (P=.0149); and 10.0+/-0.5 to 15.9+/-2.2 microm (P<.0001), respectively. Although LV myocyte nuclear length increased (10.2+/-1.0 NC; 12.2+/-0.9 microm HF, n=11, P=.0006), right ventricular (RV) myocyte nuclear density and length did not alter. In this ovine chronic HF model, LV dilation and interstitial and myocyte remodeling resemble human ICM.

Animals↗
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Does the progression of myocardial fibrosis lead to atrial fibrillation in patients with hypertrophic cardiomyopathy?

The majority of left ventricular (LV) inflow volumes in hypertrophic cardiomyopathy (HCM) depend on atrial contraction because of impaired LV relaxation. If HCM is complicated by atrial fibrillation (AF), heart failure can develop because of the loss of atrial contraction. The purpose of this study was to determine the relationship between the development of AF and myocardial fibrosis or intramyocardial small artery (IMSA) stenosis in autopsied hearts with HCM. Studies were performed in five HCM hearts with AF (AF group) and five HCM hearts without AF (non-AF group). LV specimens were divided into the inner (IT), middle (MT), and outer (OT) thirds. We selected at random 120 fields and 20 IMSAs from each layer and assessed them quantitatively using an image analyzer. We determined the extent of fibrosis (%F) and the degree of stenosis of each IMSA (%L). The %F in the AF group was greater than in the non-AF group (P<.01). In the AF group, the %F of the IT was greater than in the MT and the OT (P<.01). In the non-AF group, the %F of the IT was greater than in the MT (P<.05), and the %F of the MT was greater than in the OT (P<.01). The %L was similar in the AF and non-AF groups. In both groups, the %L of the IT was lower than in the MT (P<.01), which was lower than that of the OT (P<.05). LV fibrosis is more severe in patients with HCM and AF than in those without AF. Therefore, myocardial fibrosis might impair LV relaxation, resulting in hemodynamic intolerance to AF.

Adult↗
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Cerebral artery thrombosis as a cause of striatocapsular infarction. a histopathological case study.

Striatocapsular infarction is a distinct form of stroke, but few histopathological studies have been performed concerning acute lesions. We report the postmortem findings of a patient with an infarct who died shortly after onset. A 72-year-old man died of acute myocardial infarction 6 days after the onset of left-sided striatocapsular infarction. Autopsy revealed thrombus formation of the left middle cerebral artery (MCA) trunk. The lateral striate arteries irrigating the area of the infarct branched off distal to the arterial segment occluded with a thrombus. The cortical vessels were perfused by leptomeningeal collaterals. This report histopathologically confirmed thrombus formation of the MCA resulting in striatocapsular infarction.

Aged↗
PubMedDate not supplied

Cerebral primitive neuroectodermal tumor in an adult male. A case report.

BACKGROUND: Primitive neuroectodermal tumors (PNETs) are very rare. Malignant tumors of the cerebrum in young individuals are composed predominantly of undifferentiated cells, with moderate differentiation along either neuronal or glial lines. To our knowledge, cerebral PNETs in adults are extraordinarily rare and have been reported in only 11 cases, with little cytologic documentation in the literature. The cytopathologic, immunohistochemical and ultrastructural features of cerebral PNET arising in an adult male are presented. CASE: A cystic tumor, on computed tomography and magnetic resonance imaging, arose from the left frontal lobe in a 39-year-old man and contained histopathologic features of PNET. Specimens obtained from surgery revealed the presence of an undifferentiated type of PNET with moderate neuronal and glial differentiation and mild characteristic findings of peripheral PNET. The cytologic and histologic specimens showed evidence of a scattered pattern of blastic and undifferentiated tumor cells and a neural arrangement with Homer-Wright-like rosettes. Immunohistochemically, the tumor cells were glial fibrillary acidic protein, neuron-specific enolase, synaptophysin and CD-99 positive and epithelial membrane antigen, S-100 protein and vimentin negative. Ultrastructurally, neither microtubular structures nor intermediate filaments, except neurosecretory granules, were found in the tumor cells. CONCLUSION: Both immunohistochemical and ultrastructural studies on cytologic and histologic slides were important for the diagnosis of PNET because of establishing not only undifferentiated tumor cells but also neural and glial differentiation.

Adult↗
PubMedDate not supplied

Persistent infection with human polyomavirus revealed by urinary cytology in a patient with heart transplantation. A case report.

BACKGROUND: Management after heart transplantation must deal with the twin risks of rejection and infection. Early infection with viral infection, particularly cytomegalovirus (CMV), is becoming more prevalent two to three months after transplantation. To our knowledge, there has been no previous report of human polyomavirus (HPOV) infection after heart transplantation. CASE: A 20-year-old male with a history of Kawasaki disease and who had suffered from severe congestive heart failure after a coronary artery bypass graft, underwent heart transplantation. Urinary cytology demonstrated HPOV infection, the diagnosis of which was established by the immunoperoxidase technique, in situ hybridization and electron microscopy. CONCLUSION: The definitive diagnosis of HPOV infection after a heart transplant can be made on urinary cytology.

Adult↗
PubMedDate not supplied

The storage form of human renal renin.

We isolated renin granules from cadaver kidneys using discontinuous sucrose density gradient centrifugation, and investigated the storage form of the renin from these granules. Approximately 23% of the total renin activity in the original homogenate was obtained from the surface phase between 1.6 and 1.7 M sucrose (Fraction 6). Granule renin extracted from the granules in Fraction 6 was separated into active and inactive renin using pepstatin affinity chromatography. Only the active renin had an affinity for pepstatin. The inactive renin, albeit activated by trypsin, was little activated by acidification. The proportion of inactive renin was about 25% of the total granule renin (active renin + inactive renin). Trypsin concentrations over 10 micrograms/ml resulted in a decrease in the renin activity of the trypsin-activated renin, but the enzymatic activity of active renin was decreased by trypsin. With gel filtration, the inactive renin revealed a single peak, and the molecular weight (MW) was 48,000. The active renin had a MW of 44,000. The inactive renin could be activated by trypsin without an apparent change in molecular weight.

Aged↗
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Artery-to-artery embolism from a thrombus formed in stenotic middle cerebral artery. Report of an autopsy case.

The authors report an autopsy case with repeated transient ischemic attacks and subsequent strokes demonstrating evidence of artery-to-artery embolism from thrombi generated in the stenotic middle cerebral artery to the distal cortical branches. This case substantiates the existence of intracranial artery-to-artery embolism as a cause of transient ischemic attacks and subsequent strokes, and has potential relevance for therapy.

Aged↗
PubMedDate not supplied

Primary round cell liposarcoma of the omentum. A case report.

Liposarcomas are the most common of the malignant soft tissue tumors arising in the mediastinum and retroperitoneum. We have treated patients for round cell liposarcoma, an unusual histologic subtype, which is reported to be histologically mistaken for Ewing's sarcoma, lymphoma and other round cell neoplasms. The successful resection of a 2,300-g round cell liposarcoma of the omentum was recently performed at our hospital. Ultrastructural observations of this tumor are characterized by massive proliferation of the mitochondria in addition to the presence of lipid vacuoles in tumor cells. To our knowledge, no description of substantial mitochondrial proliferation in round cell liposarcoma has appeared previously in the literature; therefore, this is the first case report of histopathologic, cytopathologic and electron microscopic observations on this extremely rare tumor.

Female↗
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Thrombus in a natural left ventricle during left ventricular assist: another thromboembolic risk factor.

Systemic thromboembolism is one of the serious complications during use of a left ventricular assist system (LVAS). The authors' original LVAS has excellent antithrombogenicity to reduce this risk, but thrombus formation in a natural left ventricle (LV) is another risk factor for systemic embolization. We used our LVAS in 22 patients. Of these, LV wall motion was studied in 15, and a smoke-like echo disclosed thrombus in the LV in eight. When LVAS sufficiently supported the systemic circulation, LV wall motion was irregular upon closure of the aortic valve. Upon recovery of LV function and decrease of LVAS flow, the smoke-like echo diminished and LV thrombus decreased in one, but LV thrombus remained unchanged or increased in seven. Systemic administration of antithrombotic agents had an unclear effect. Seven of eight patients with LV thrombus on echo died during or after LVAS. In these seven, a high incidence of LV thrombus (71%), and systemic embolism to the brain (29%) or kidney (86%), were revealed at necropsy. We subsequently used local heparinization to prevent LV thrombus formation. One patient with a smoke-like echo had no evidence of LV thrombus or systemic embolism. During LV assist, careful management of the LVAS, and intra-LV heparinization should be considered to reduce the risk of thrombus formation in the natural LV.

Adult↗
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Primary ovarian lymphoma associated with Meigs' syndrome: a case report.

A case is presented of primary undifferentiated lymphocytic lymphoma, non-Burkitt, of the right ovary associated with Meigs' syndrome. The diagnosis was based upon the findings of tumor imprint cytology, histopathology and electron microscopy. The ultrastructural observations were the most diagnostic, revealing well-developed, rough endoplasmic reticulum and dilated cisternae in the cytoplasm of the tumor cells. An association of Meigs' syndrome with a rare ovarian lymphoma has not been previously reported. The abnormal-appearing mesothelial cells in the pleural effusion were proven to be reactive and not malignant by comparison with the tumor cells demonstrated by imprint cytology of this ovarian lymphoma.

Adult↗