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Biomedical subjects

T Harada

Publications and source records attributed to T Harada.

At least 1,405 records · Page 78Linked to original sources
PubMedDate not supplied

An epithelioid cell type of amelanotic melanoma of the pinna in a Fischer-344 rat: a case report.

An epithelioid cell type of spontaneous amelanotic melanoma in the pinna of an aged albino Fischer-344 (F-344) rat is described. When the rat was necropsied at 109 wk of age, the pinnal tumor was recognized as a white spherical mass of 4 mm in diameter. Histologically, the tumor was observed in the dermis and composed of large round or polyhedral epithelioid eosinophilic cells that were arranged in various-sized cell nests. Immunohistochemistry demonstrated that the tumor cells were positive for S-100 protein and vimentin but negative for keratin and a rat macrophage antigen. Ultrastructurally, a few single membrane-bound premelanosomes that were accompanied by many primary lysosome-like bodies containing very fine granules were present in the cytoplasm of the tumor cells. This study has disclosed that, in addition to spindle cell variants of amelanotic melanomas, an epithelioid cell type of amelanotic melanoma may occur spontaneously in the skin of F-344 rats.

Animals↗
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Morphological and ultrastructural study of the histogenesis of meningeal granular cell tumors in rats.

To clarify the cell of origin of granular cell tumors in the rat brain, light and/or electron microscopic examinations were performed on 40 cases of spontaneous meningeal tumors in Wistar (Jcl: Wistar) rats. The meningeal tumors were histologically subclassified into 3 types: meningothelial meningiomas (MMs), 3 cases; granular cell tumors (GCTs), 28 cases; and mixed forms (MIXs) of GCTs and MMs, 9 cases. Of these tumors, 2 MMs, 2 GCTs, and 3 MIXs were examined by transmission electron microscopy. Tumor cells of MMs were characterized by cytoplasmic intermediate filaments and prominent interdigitating cell processes often connected with cellular junctions without surrounding basal laminae. GCTs were composed of 2 cell types: granular cells with many dense bodies and filamentous cells with fine intermediate filaments. MIXs consisted of granular cells, filamentous cells, and intermediate cells. The tumor cells in GCTs and MIXs were apposed to each other and connected with cellular junctions. MIXs displayed a spectrum of cellular differentiation in that 2 MIXs had a close morphological resemblance to GCTs and the other one to MMs. These findings indicate there might be a histogenetic sequence among MMs, GCTs, and MIXs. The present study supports the suggestion that GCTs and MIXs may be variants of MMs from the meningeal arachnoid cell.

Animals↗
PubMedDate not supplied

Intraabdominal lymphangiosarcoma in a Fischer-344 rat.

A Sarcoma arising in the abdominal cavity in an aged Fischer-344 rat was studied by immunohistochemistry and electron microscopy. The white-yellow soft mass was located on the lumbosacral vertebrae, compressing adjacent parenchymal organs. The tumor was made up of spindle shaped cells situated in a background of myxoid substance and a small amount of reticulin and collagen fibers. The tumor cells grew in a loose storiform pattern and often adhered to each other by their cell processes to form ovoid or slitlike spaces. Immunohistochemically, the tumor cells were strongly positive for vimentin but negative for keratin, macrophage ED1 antigen, alpha-smooth muscle actin, Factor VIII-related antigen, and S100 protein. Electron microscopy demonstrated the endothelial differentiation of the tumor cells, such as occasional luminal spaces, a small number of micropinocytotic vesicles, and interdigitating junctions with desmosomes between cell processes of adjacent cells. Furthermore, its endothelial origin was suggested by the presence of electron-dense rods resembling Weibel-Palade bodies. Instead of a definitive basement lamina surrounding the tumor cells, there were extracellular thin "anchoring filaments" that were attached to the cell surface at areas of increased electron density. These findings indicate that the tumor is of lymphatic vessel type rather than blood vessel type.

Abdominal Neoplasms↗
PubMedDate not supplied

Immunohistochemical localization of microcystin-LR in the liver of mice: a study on the pathogenesis of microcystin-LR-induced hepatotoxicity.

The relationship between the intralobular sites of hepatotoxic injury and the distribution of microcystin-LR (MCLR), an inhibitor of protein phosphatases 1 (PP1) and 2A (PP2A), was examined using an immunohistochemical method with a monoclonal antibody specific to MCLR on the livers of mice receiving a single i.p. injection of the MCLR. Immunoblotting and high-performance liquid chromatography analyses of liver extracts were also performed to determine the binding form of MCLR to PP1 and PP2A (MCLR-PP1/PP2A adducts) and free MCLR. Immunohistochemistry revealed a discernible intensity of staining in the centrilobular regions where hemorrhage and apoptosis occurred. In these regions, immunopositivity was evident in the cytoplasm and nuclei of the hepatocytes; some apoptotic cells were also immunopositive. In contrast, coagulative necrosis, which was mainly evident in the midlobular regions, was completely negative. Analysis of liver extracts demonstrated MCLR-PP1/PP2A adducts, but free MCLR was below detection limit. These results suggest that the immunohistochemical localization of MCLR in centrilobular hepatocytes is closely associated with the onset of hemorrhage and apoptosis and is related to adduct formation. The occurrence of coagulative necrosis however might also be related to other factors such as ischemia/hypoxia.

Animals↗
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Temporal bone histopathologic findings in congenital anomalies of the oval window.

The histopathologic findings in five temporal bones from three cases showing various stages of oval window development arrest are presented. The anomalies ranged from complete absence of the oval window to congenital cartilaginous fixation of the stapedial footplate. Surgical approaches fro establishment of a new oval window must take into consideration the frequent association of facial nerve anomalies with anomalies of the oval window.

Ear, Inner↗
PubMedDate not supplied

Evaluation of anti-HTLV-1 antibody in primary glomerulonephritis.

Human T-cell leukaemia virus type-1 (HTLV-1) is known to cause adult T-cell leukaemia. The prevalence of anti-HTLV-1 antibody in haemodialysis patients has been reported to be higher than that in the general population. The anti-HTLV-1 antibody-positive rate in patients with primary glomerulonephritis in the Nagasaki district, an endemic area of HTLV-1, was evaluated. The antibody-positive rates in patients with primary glomerulonephritis (9.9%) and in haemodialysis patients (18.4%) were significantly higher than the rate in general blood donors (6.6%). Of 142 patients with primary glomerulonephritis, 14 (9.9%) were positive for the antibody; histological evaluation of these patients showed minor glomerular abnormality in one, mesangial proliferative glomerulonephritis in eight (IgA nephropathy in six and non-IgA nephropathy in two), membranous nephropathy in three, and crescentic glomerulonephritis in two. Evaluation of 10 antibody-positive patients by immunofluorescent microscopy showed immunocomplex-type nephritis in nine, suggesting the involvement of HTLV-1-associated antigen in the development and progression of glomerulonephritis.

Adolescent↗
PubMedDate not supplied

The "nutcracker" phenomenon in combination with IgA nephropathy.

The "nutcracker" phenomenon results from compression of the left renal vein between the superior mesenteric artery and the aorta. The main features of this phenomenon are non-glomerular haematuria on urinalysis and stenosis of the left renal vein with dilatation of the vein distal to the stenosis. The characteristics of two patients with the "nutcracker" phenomenon complicated by immunoglobulin A nephropathy were compared with those of 10 patients showing only the "nutcracker" phenomenon. Patients with the "nutcracker" phenomenon complicated by immunoglobulin A nephropathy showed aggravation of haematuria after upper respiratory infections, urinary red cell morphology indicating haematuria of glomerular origin, elevation of serum IgA, persistence of proteinuria, and granular casts in the urine. The coexistence of immunoglobulin A nephropathy was suspected when these characteristics were observed in patients with the "nutcracker" phenomenon. In such cases, a renal biopsy is needed for a final diagnosis.

Adult↗
PubMedDate not supplied

Immunohistochemical analysis of type III and IV collagens in tubulointerstitial damage in human benign nephrosclerosis.

Prolonged hypertension causes structural changes including glomerulosclerosis and tubulointerstitial damage of the kidney, termed benign nephrosclerosis. It is generally accepted that, in benign nephrosclerosis, increased accumulation of extracellular matrix in the glomeruli results in glomerulosclerosis. Little is known, however, about the possible role of the extracellular matrix in the tubulointerstitial damage in benign nephrosclerosis. In this study, the possible roles of type IV basement-membrane collagen and type III interstitial collagen in tubulointerstitial damage caused by hypertension were explored. Immunohistochemical techniques were used to investigate the distribution of type III and type IV collagens in the kidney sections of 15 patients with benign nephrosclerosis with tubulointerstitial damage and in 10 controls. In the control renal sections strong immunostaining for type III collagen was found in the interstitium and immunostaining for type IV collagen was present in the tubular basement membrane and weakly in the interstitium. In the patients with tubulointerstitial damage there was increased immunostaining for both type III and type IV collagens in the expanded interstitium and damaged tubules than was found in the control kidney sections. These findings indicate that increased accumulation of both type III and type IV collagens might play a significant role in the tubulointerstitial damage in benign nephrosclerosis.

Atrophy↗
PubMedDate not supplied

Significance of increased accumulation of type VI collagen and transforming growth factor beta 1 in tubulointerstitial damage in hypertensive nephrosclerosis: an immunohistochemical study.

The distribution of type VI collagen and transforming growth factor beta 1 (TGF beta 1) was studied by immunohistochemistry in 12 renal biopsy specimens of hypertensive nephrosclerosis and five control cases. In control kidneys, the immunostaining of type VI collagen was found in the mesangium, glomerular basement membrane and tubular basement membrane. For TGF beta 1, mesangium, glomerular basement membrane, tubular basement membrane and tubular epithelial cells stained positively in the control kidneys. In contrast to the control cases, markedly increased immunostaining for both type VI collagen and TGF beta 1 was consistently observed in tubulointerstitial damage in hypertensive nephrosclerosis. These immunohistochemical findings provide the evidence for a parallel increase of both type VI collagen and TGF beta 1 during the process of tubulointerstitial injury in hypertensive nephrosclerosis. From the results of the present study, it is speculated that TGF beta 1 may contribute to the tubulointerstitial injury by stimulating increased synthesis of various extracellular matrix including type VI collagen.

Adult↗
PubMedDate not supplied

Prostaglandin E1 for renal papillary necrosis in a patient with diabetes mellitus.

We report a case of renal papillary necrosis with diabetes mellitus which was treated with prostaglandin E1. An intravenous infusion of 40 mg/day prostaglandin E1 was given for 14 days in an attempt to improve renal circulation. Treatment resulted in an improved creatinine clearance, renal plasma flow and renogram, and proteinuria was decreased. The administration of prostaglandin E1 produced an improvement in renal haemodynamics and can be considered as a possible therapy for renal papillary necrosis in diabetic patients.

Aged↗
PubMedDate not supplied

Exploration of Vogt-Koyanagi-Harada syndrome by infrared choroidal angiography with indocyanine green.

The choroid affected by the Vogt-Koyanagi-Harada syndrome (VKH) has seldom been explored by indocyanine green choroidal angiography. Five patients with definite diagnosis of VKH underwent this investigation. The first case had the most marked leakage, very similar to that on fluorescein angiography. The right eye of case 2 showed fewer leakage points on ICG than on fluorescein angiography, compared with case 1. The left eye of case 2 did not show any leakage. Cases 3, 4 and 5 yielded segmental hyperfluorescence, distant from the posterior pole, which could not be identified by fluorescein angiography. This might indicate segmental choroiditis. There were two types of hypofluorescent lesions; all the cases except case 2 showed early hypofluorescence. Hypofluorescent areas corresponding to overlying retinal detachment were seen in the right eye of case 4. Multiple spots, late hypofluorescence, about 200 to 500 um in size appeared throughout the posterior pole in four eyes out of ten. In conclusion, indocyanine green choroidal angiography provides a wider variety of pictures than fluorescein angiography.

Adult↗
PubMedDate not supplied

Nasal mucociliary clearance under various conditions.

We applied the tagged-particle method or the saccharin method or both to the nasal mucociliary clearance. There was no effect of ageing on the transport time of saccharin in control subjects of ages under 60, and 70% of control subjects of ages more than 60 had the same transport time as that obtained in younger control subjects. The significant inverse correlation between the mucociliary transport rates with the particle method and the transport time with the saccharin method were established in control subjects, but not, however, in patients with chronic sinusitis. The mucociliary transport rates were measured under non-physiologic conditions of the nose: laryngectomy, chronic sinusitis, Sjögren's syndrome, and Kartagener's syndrome.

Adolescent↗
PubMedDate not supplied

Endolymphatic hydrops and III type allergic reaction.

IgG antibody and complement are both present in endolymphatic fluid, and it is possible that immune complex may form in endolymphatic fluid. However, there are still obscure points as to whether endolymphatic hydrops is due to immune complex, but it is quite possible that it is only one causative factor in endolymphatic hydrops.

Animals↗
PubMedDate not supplied

Morphological study of blood-labyrinth barrier in the vestibular organs under normal and experimental acute hypertensive and acute hypotensive conditions.

In order to examine a blood-labyrinth barrier in the vestibular region, capillary permeability of the vestibular organs, i.e. the sacculus, the utriculus and the ampullae of semicircular canals, were studied light and electron microscopically by the horseradish peroxidase (HRP) tracer method. Intravenously infused HRP was not observed outside capillaries because of the tightness of endothelial tight junctions and the paucity of pinocytotic vesicles. Furthermore, the effect of drug-induced acute hypertension and acute hypotension on the capillaries of the vestibular organs was studied morphologically using the tracer technique. In each experiment, there was no extravasation of HRP from capillaries, thus agreeing with the results of the experiment made under normal conditions. These findings mean that capillaries of the vestibular region are of ordinary brain capillary type and contribute to the blood-labyrinth barrier to macromolecules such as HRP both under normal conditions and following abrupt changes in blood pressure.

Animals↗
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Lymphocyte subsets of maxillary mucosa in chronic inflammation.

Subsets of infiltrating lymphocytes within maxillary sinus mucosae of patients with chronic sinusitis were investigated by immunoperoxidase staining of frozen sections with the use of monoclonal antibodies. The most commonly observed infiltrating cell type was suppressor/cytotoxic T cells (CD8+) and smaller subpopulations of lymphocytes were helper/inducer T cells (CD4+) and B cells (CD20+). Variable numbers of HLA-DR+ cells were commonly observed in the lamina propria. The fibrous type of chronic sinusitis was found to have more suppressor/cytotoxic T cells (CD8+) and lower CD4/CD8 ratio than the other histopathological types.

Adult↗
PubMedDate not supplied

The importance of the hypoosmotic swelling test and acrosin activity assay for identifying subpopulations of idiopathic infertile men.

Semen samples collected from fertile donors (n = 13) and pooled samples from idiopathic infertile men (n = 19) were used in this study. Measurements of the total sperm acrosin activity and the hypoosmotic swelling test (HOST) were performed in all the samples. The percentage of swollen spermatozoa and acrosin profiles were significantly lower in the infertile men than in the fertile donors. Considering the lowest values of the outcome of the HOST and the acrosin activity assay in the group of fertile men as the lowest normal values, it was proven that HOST and acrosin activity assay could identify subpopulations of infertile men of 37 and 26%, respectively. The results tend to support the employment of the HOST and the acrosin activity assay in the evaluation of idiopathic infertile men.

Acrosin↗
PubMedDate not supplied

Secondary excision of choledochal cysts after previous cyst-enterostomies.

BACKGROUND/AIMS: Patients with a choledochal cyst previously treated by internal drainage should undergo secondary cyst excision. The results of such secondary excisions have not yet been reported. METHODOLOGY: Over a 27-year period, 121 patients underwent excision of a choledochal cyst at our hospitals. Of these, 14 patients underwent secondary cyst excision following internal drainage. These patients were compared retrospectively with the remaining 107 patients who underwent primary cyst excision. RESULTS: Blood loss and operative time were greater, and early and late post-operative complications were significantly more frequent in the secondary excision group. Wound infection (early complication), pancreatic stones (late complication), and hepatolithiasis (late complication) were significantly more common in the secondary excision group. Histologically, inflammation and biliary glands were more frequently seen in the resected bile ducts in the secondary excision group. CONCLUSIONS: The long-term results of secondary excision of choledochal cysts are worse than after primary excision. The frequent late complications may be related to the development of biliary glands as a consequence of cyst-enterostomy.

Adolescent↗