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Biomedical subjects

K Wakaki

Publications and source records attributed to K Wakaki.

At least 19 recordsLinked to original sources
PubMed2001

Animal model of diabetic nephropathy.

Injection of subtotally nephrectomized rats with streptozotocin produced metabolic abnormalities resembling diabetic nephropathy in humans. These abnormalities were hyperglycemia, hypoinsulinemia, azotemia, hypertriglyceridemia and hypercholesterolemia, accompanied with an increase in glycosylated protein. Extraordinary changes in the urinary excretion of glucose and protein were also observed in rats that received streptozotocin treatment after subtotal nephrectomy. In addition, the level of creatinine clearance was significantly decreased. The pathological findings in the kidney of these rats revealed lesions of the glomerular capillary loops, mesangial area and Bowman's capsule. Coagulation was also found in the glomerular capillaries. Our results suggest that this rat model would be useful for studies of diabetic nephropathy.

Animals↗
PubMed1999

Rat liver serine dehydratase. Bacterial expression and two folding domains as revealed by limited proteolysis.

A pCW vector harboring rat liver serine dehydratase cDNA was expressed in Escherichia coli. The expressed level was about 5-fold higher in E. coli BL21 than in JM109 cell extract; the former lacked two kinds of proteases. Immunoblot analysis revealed the occurrence of a derivative other than serine dehydratase in the JM109 cell extract. The recombinant enzyme was purified to homogeneity. Staphylococcus aureus V8 protease and trypsin cleaved the enzyme at Glu-206 and Lys-220, respectively, with a concomitant loss of enzyme activity. Spectrophotometrically, the nicked enzyme showed a approximately 50% reduced capacity for binding of the coenzyme pyridoxal phosphate and no spectral change of circular dichroism in the region at 300-480 nm, whereas circular dichroism spectra of both enzymes in the far-UV region were similar, suggesting that proteolysis impairs the coenzyme binding without an accompanying gross change of the secondary structure. Whereas the nicked enzyme behaved like the intact enzyme on Sephadex G-75 column chromatography, it was dissociated into two fragments on the column containing 6 M urea. Upon the removal of urea, both fragments spontaneously refolded. These results suggest that serine dehydratase consists of two folding domains connected by a region that is very susceptible to proteases.

Animals↗
PubMed1999

Synovitis in rheumatoid arthritis: scoring of characteristic histopathological features.

Synovial tissue specimens obtained from the knee joints of 40 patients with rheumatoid arthritis (RA) and from 22 patients with osteoarthritis (OA) were examined histologically. The histopathological features of RA synovitis and OA synovitis were then compared. Seven criteria items of histopathological features characteristic to RA synovitis were given a score of 1-3 points each in order to evaluate the histological severity of the seven items. Their total scores were then calculated. A comparison of the total RA synovitis score and the total OA synovitis score revealed that RA synovitis showed more than 11 points (maximum 20 points), while OA synovitis showed less than 10 points in all but two cases. Furthermore, the total scores of RA synovitis were then determined in the same manner for other joints, where it was confirmed that five other joints had scores of more than 11 points as well; that is, the intercarpal, wrist, elbow, ankle and hip joints in 52 patients with RA. From these results, it was concluded that in the histological examination of biopsied synovial tissue of RA, if the total score for synovitis is more than 11 points (maximum 20 points), an histological diagnosis of RA synovitis can be confirmed.

Adult↗
PubMed1998

Cystic spinal cord tumors: magnetic resonance imaging correlated to histopathological findings.

We report the characteristics of magnetic resonance imaging (MRI) of cystic intradural extramedullary spinal cord tumors (cystic neurilemmoma, epidermoid cyst, and enterogenous cyst). T1-weighted MRI enhanced with gadolinium-DTPA clearly demonstrated the rim morphology of these tumors. The comparison between the rim enhancement pattern and histopathological findings offered possible qualitative diagnosis of these cystic spinal cord tumors by MRI.

Adult↗
PubMed1998

Multifocal clear cell meningioma in the spine: a case report.

Clear cell meningioma is a rare morphologic form of meningioma. This case report describes a very rare case of multifocal clear cell meningioma in the thoracic and lumbar spine. A 9 year old patient presented with back pain and popliteal pain, which were aggravated by trunk motion and knocking. Magnetic resonance imaging (MRI) suggested a meningioma at the L2 level. An intradural extramedural tumor attached to the cauda equina was surgically removed and pathological diagnosis was clear cell meningioma. The patient began to complain of back pain at the Th12 level 4 months postoperatively. Retrospective analysis of MRI before the first operation revealed the small tumors at Th12 and L5 levels; comparison with a new MRI showed the rapid growth in 4 months. Adjunctive surgical resection was carried out and the back pain disappeared. These tumors had the same pathological findings. In conclusion, in young patients with suggested meningioma in the lumar spine, clear cell meningioma should also be considered, and the possibility of multifocal occurrence and postoperative recurrence must be taken into account.

Age of Onset↗
PubMed1998

Internal jugular vein malformation with mature adipose deposits in the mediastinum.

Anomalies of the internal jugular vein are uncommon and not frequently experienced. Either a fusiform or saccular dilatation of the veins has been termed phlebectasia by some investigators and venous aneurysm by others. In 1928 Harris was the first to describe this condition using the term "congenital venous cyst." Relatively few cases of head and neck venous aneurysms have since been reported. We herein report a case of congenital internal jugular vein malformation while discussing both the diagnosis and pathology.

Adipose Tissue↗
PubMed1995

Co-expression of fibroblastic, histiocytic and smooth muscle cell phenotypes on cultured adherent cells derived from human palatine tonsils: a morphological and immunocytochemical study.

Adherent cells derived from human palatine tonsils were isolated and cultivated. Exponentially growing adherent cells (TAC) were observed by phase-contrast microscopy and transmission electron microscopy. Immunocytochemical studies were also performed. TAC were composed of relatively monotonous cells with polygonal or spindle shapes and high proliferative activity. In addition to the development of rough endoplasmic reticulum and lysosomes, the TAC possessed a moderate amount of pinocytotic vesicles and a few microfilaments. All of the TAC strongly expressed fibroblastic markers and partial monocyte/macrophage markers, such as beta-subunit of prolyl 4-hydroxylase (DAKO-fibroblast), lysozyme, anti-alpha-1-antichymotrypsin (alpha ACT), and CD68 (KP-1, EBM/11). It was noted that, as the TAC were cultured for a longer period, they gradually increased the reactivity with the monoclonal antibody PG-M1. Furthermore, the TAC expressed myocytic phenotype, such as alpha-smooth muscle actin (alpha SMA) with various intensity. Moreover, as to extracellular matrix, TAC stained for collagen type I, collagen type III, laminin, and fibronectin. Collagen type IV was weakly positive. The results presented here showed that the TAC expressed three different phenotypes of fibroblasts, histiocytes and smooth muscle cells at the same time. The monoclonal antibody raised against the TAC reacted strongly with the subendothelial pericytes and/or smooth muscle cells in the extrafollicular area in human tonsils. The present results also suggested that the origin of the TAC was probably subendothelial pericytes and/or smooth muscle cells of the microvasculatures in the tonsil.

Adult↗
PubMed1995

Experimental granulomatous vasculitis induced by sensitization with Ascaris suum antigen in mice.

Experimental sensitization by repeated intramuscular injection of Ascaris suum antigen (Ag-As) supplemented with Freund's incomplete and complete adjuvants was carried out in 50 BALB/c CrSl c male mice (sensitized group) for 24 weeks, and the results were compared with those in a control group of 25 mice. At the injection sites of the sensitized group, granulomatous angiitis with eosinophil infiltration was observed in all mice, and fibrinoid angiitis in only four. By light and electron microscopic examinations pulmonary granulomatous vasculitis with a few eosinophils was observed at a high frequency (80%) after 12 experimental weeks. Immunohistochemical examination revealed pulmonary vascular and perivascular infiltration of L3/T4 (CD4) positive cells, B cells, IgG and C3 positive cells in addition to activated macrophages, Thy-1 T cells, IgE positive cells, and IgM positive cells after 12 experimental weeks. There were significant increases in the eosinophil cell count of the peripheral blood, the hemagglutination titers of the sheep erythrocytes, IgE and IgM antibodies to Ag-As by ELISA and Western blotting after 8 experimental weeks. After 12 experimental weeks the IgG antibody to the Ag-As was low, but it increased significantly, and the sera showed multiple precipitation lines to the Ag-As by the Ouchterlony method. In conclusion, the pulmonary granulomatous vasculitis in this study is considered to consist of allergic reactions of type IV and probably type III based on type I.

Animals↗
PubMed1994

Effect of eicosapentaenoic acid ethyl ester on albuminuria in streptozotocin-induced diabetic rats.

Wistar rats (4-week-old) were administered with streptozotocin (45 mg/kg) through tail veins. After 3 months, diabetic rats were divided into 2 groups. One group (EPA group, n = 16) was fed a lipid-free diet (90%, w/w) plus lard (8%) and 90% pure eicosapentaenoic acid ethyl ester (2%) for 6 months. The other group (control group, n = 16) was fed in the same way except that eicosapentaenoic acid ethyl ester was replaced by safflower oil. Twenty-four-hour urine was collected just before starting the experimental diets and during the 6-month experimental period at monthly intervals. There were no differences in food intake and body weight between the two groups throughout the experiment. The mean microalbuminuria of the EPA group became significantly lower than that of the control group after 4 months on the diets through the end of the study (6 months). The mean microalbuminuria levels at the end of the study were 1.38 mg/day in the EPA group (n = 9) and 5.19 mg/day in the control group (n = 6) (p < 0.01). Eicosapentaenoic acid administration might retard the progression of diabetic nephropathy by reducing microalbuminuria.

6-Ketoprostaglandin F1 alpha↗
PubMed1994

[A case of small cell carcinoma of the stomach with multiple liver metastases].

We report a very rare case of small cell carcinoma of the stomach. A 69-year-old man, complaining of epigastric discomfort, was admitted to our hospital. Gastric endoscopy showed a Borrmann type 3 tumor at the lesser curvature of the cardia. Multiple liver metastases were observed in CT-scan, and total gastrectomy and cannulation to the hepatic artery were carried out. Macroscopically it was gastric cancer with P0H3N1T3M0, Stage IV b, histologically small cell carcinoma, intermed, INF gamma, ss, ly1, v3, n1(+), ow(-), aw(-). Immunochemotherapy was carried out, but liver metastases developed. The prognosis of this disease is very poor, resulting from rapidly developing metastases and invasion, in spite of treatments such as gastrectomy, chemotherapy and radiotherapy. More effective treatments are needed.

Aged↗
PubMed1993

Lung carcinoma mimicking malignant lymphoma: report of three cases.

Three cases of lung carcinomas with unusual histologic appearances that have received little or no comment in the literature are presented. They were initially confused with malignant lymphoma because of a diffuse proliferation of relatively monotonous cells simulating large-cell immunoblastic lymphoma. In each case, the possibility of malignant lymphoma was excluded with confidence after the immunohistochemical study (leucocyte common antigen negative and cytokeratins positive), although with conventional microscopy several foci of cohesive groups of tumor cells were observed. The tumors were ranked at the clinical stage II or III when they were initially discovered, but all patients died of disease within 1 year. The present three tumors show an aggressive behavior and could be classified into a peculiar variant of 'large cell' carcinoma. It is necessary for surgical pathologists to have an idea of these variants of lung carcinoma in order to avoid erroneous diagnosis.

Adult↗
PubMed1988

Hyperplasia of juxtaglomerular cells and renomedullary interstitial cells after renal arterial embolization in patients with renal cell carcinoma.

Renal tissue was obtained from 36 patients with renal cell carcinoma, some of whom received renal arterial embolization. The removed specimens was examined histopathologically and the concentration of some vasoactive substances in these patients was measured. Nephrectomy alone produced no discernible changes in blood pressure, vasoactive substances determined or histopathological findings of the kidney. Renal arterial embolization raised the blood pressure in association with the elevation of plasma renin activity (PRA) and urinary prostaglandin (PG) E2 excretion. A linear relationship was found to exist between PRA and mean blood pressure (r = 0.70, p less than 0.001). Hyperplasia of the juxtaglomerular (JG) apparatus, and high granularity of sudan black B granules in renomedullary interstitial cells were confirmed in removed kidneys of patients who had received embolization alone. Subsequently high renin production would be anticipated to influence overproduction of renal PG E2 in acute ischemic kidney in patients with renal cell carcinoma, and hypertension following renal arterial embolization appears to be caused by the hyperplasia of the JG apparatus.

Aged↗
PubMed1988

[Recurrent meningioma with malignant changes and extracranial multiple metastases].

A case of recurrent meningioma with malignant change and extracranial multiple metastases is reported. A 51-year-old female was operated on and left parasagittal meningioma was extirpated by Simpson grade II. Histological diagnosis was fibroblastic and transitional meningioma with slight atypism. Six years later, however, the tumor (transitional meningioma with slight mitosis) recurred in the same portion and was removed again by Simpson grade II. Further more, four years after the second operation, bilateral parasagittal meningioma (atypical meningioma; transitional type) was extirpated by Simpson grade I including superior sagittal sinus and falx. Only eight months after the last operation, a few tumors with central necrosis were demonstrated in the bilateral parasagittal area on a computerized tomography scan and she received radiation therapy. But the tumor had metastasized to the extracranial multiple organs including lungs, liver, pancreas, adrenal gland, muscles, multiple bones and lymph nodes. Post mortem diagnosis was malignant meningioma. We reviewed and discussed the characteristics of metastasizing meningioma, the effectiveness of radiation therapy on the prevention of recurrence of meningioma and the curative effect of radiation therapy for recurrent or metastasized meningioma.

Abdominal Neoplasms↗
PubMed1985

Cystinosis with marked atrophy of the kidneys and thyroid. Histological and ultrastructural studies in an autopsy case.

The eldest autopsied case (a 23-year-old man) of infantile form of cystinosis with uremia and myxoedema was reported. The cystine content per gram wet tissue of various organs was arranged as follows: the thyroid (4.61 mg), kidney (1.71 mg), eye (0.75 mg), spleen (0.65 mg), liver (0.49 mg), and brain (0.016 mg). In polarized light microscopy, cystine crystals were detected in the epithelial cells and epithelial lumina of both kidneys by Wollaston test, and foam cells with cystine crystals were histologically found in the reticuloendothelial and other organs, especially in the bone marrows. Moreover, electron microscopic findings revealed square, rectangular or lozenge-shaped small cystine crystal profiles in osmophilic dense bodies of the histiocytic cells and in the cytoplasm of the foam cells. In some of them, positive reaction for acid phosphatase activity was specifically localized at the periphery of the cystine crystal profiles.

Adult↗
PubMed1984

Vascular lesions in systemic lupus erythematosus (SLE) with pulmonary hypertension.

An autopsy case with SLE suffering from Raynaud's phenomenon and pulmonary hypertension was reported. Histological examinations revealed systemically marked fibrous intimal thickening of arteries and arterioles with or without thrombus throughout the whole body, especially of the pulmonary arteries and arterioles. Pulmonary arterial changes in the present case were compared with those in 52 autopsied cases with SLE without pulmonary hypertension, but there were no cases with such marked arterial changes as the present case. In addition, the incidence of pulmonary thrombosis was significantly higher in the cases with Raynaud's phenomenon than the cases without this phenomenon. However, the relation between pulmonary hypertension and Raynaud's phenomenon, pulmonary thrombosis, fibrous pericarditis, or type of lupus nephritis in SLE could not be clarified with a significant difference.

Adult↗
PubMed1983

Coexistence of hyperplasia of renomedullary interstitial cells and juxtaglomerular cells after acute occlusion of renal artery.

A left renal artery aneurysm was found in a 45-year-old normotensive man. In an attempt to evade the possible occurrence of aneurysmal rupture, aneurysmectomy in addition to left renal biopsy (first surgery) was performed. This vascular operation led to a virtually complete renal artery stenosis concomitant with the development of hypertension. The renin-angiotensin-aldosterone system and levels of plasma prostaglandins were also increased following this failed surgery. Reconstruction of the affected renal artery was technically so difficult that left nephrectomy was carried out (second surgery). Renal specimens obtained at the first surgery revealed no histological abnormalities. Discriminating histological findings of the kidney obtained at the second surgery were remarkable; hyperplasia of the juxtaglomerular cells producing renin and hyperplasia of the renomedullary interstitial cells which had pecularities similar to cells known to secrete renal prostaglandins. High levels of the renin-angiotensin-aldosterone system and plasma prostaglandins after the first surgery were reduced following the second surgery. It is suggested that acute constriction of the renal artery led to a hyperplastic change of the juxtaglomerular cells and the renomedullary interstitial cells and stimulated an inappropriate release of renin and renal prostaglandins.

Acute Disease↗