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Biomedical subjects

K Tobe

Publications and source records attributed to K Tobe.

142 records · Page 8Linked to original sources
PubMed1985

Electron microscopy of fat-storing cells in liver diseases with special reference to cilia and cytoplasmic cholesterol crystals.

Two hundred and ten fat-storing cells in the liver of patients with liver diseases were examined electron microscopically, and 5 of them were found to project a single cilium from the perinuclear region to the space of Disse. Three cilia were in the space between a hepatocyte and their own cell body, and 2 were between a sinusoidal endothelial cell and their own cell body. In cross sections of the cilium, the axoneme consisted of 9 pairs of microtubules arranged in a cylinder and lacked a central pair of microtubules ("9 + 0" pattern). Arms and spokes were also absent in the axoneme. Therefore, the single cilium of fat-storing cells was considered to be immotile. Some fat-storing cells from a patients with alcoholic liver cirrhosis contained an angular electron lucid inclusion, which was identical to cholesterol ester crystals, suggesting the presence of disturbed cholesterol metabolism.

Cholesterol↗
PubMed1984

Clinical and histological features of sporadic non-A, non-B hepatitis.

The incidence of hepatitis A (HA), hepatitis B (HB), and non-A, non-B hepatitis (NANBH) was 27%, 30% and 43% among 73 patients with sporadic hepatitis. Epidemiological data (geographical distribution, seasonal variation, age, sex, and occupation) were not distinguishing of the type of hepatitis. Neither intrafamilial infection nor previous contact with viral hepatitis patients could be demonstrated in the NANBH cases. Fever and jaundice were less frequent in NANBH than in HA. Maximum levels of SGPT, serum bilirubin, ZTT, and gamma-globulin were significantly lower in NANBH than in HA and HB. Ten of 29 NANBH patients (35%) presented abnormal SGPT activities for more than 6 months, and four (14%) more than 12 months. In the ten patients with prolonged courses, jaundice was more frequent and maximum levels of SGPT were higher than in patients with transient courses. Histopathologic findings were not markedly different from those of HA and HB. Bile duct damage, fatty deposition, and giant multi-nucleated cells were recognized in 6, 12, and 2 NANBH patients, respectively. There were no characteristic ultrastructural changes in NANBH.

Adolescent↗
PubMed1984

Scanning electron microscopy of Ito's fat-storing cells in the rat liver.

The whole body including extended processes of Ito's fat-storing cells was observed by scanning electron microscopy in rat liver injured with lithocholic acid (LCA). Necrotic foci developed in the midlobular zone 48 h after LCA administration. Demonstration of Ito cell bodies around the foci was probably facilitated by easy detachment of hepatocytes from Ito cells. The body and the processes were located mainly between the sinusoidal endothelium and hepatocytes; sometimes they were between hepatocytes. Ito cells often were proximate to collagen fiber bundles and sometimes were attached to them. The cell body was flatly round or elliptic, 7 to 12 micron in diameter. Its surface was finely undulated with microvillous projections about 0.1 micron in length. Branching patterns of the processes resembled a fern-leaf mantling the sinusoidal endothelium. The trunks of the processes were about 2 micron in diameter and 20-30 micron in length. These processes tapered, branching into thinner processes, with the most peripheral being 0.1 micron in diameter. Ito cells and their branching processes likely strengthen sinusoidal walls and control blood flow in the sinusoids.

Animals↗
PubMed1984

A case of cornstarch granuloma.

A 57-year-old female was diagnosed as having asymptomatic cornstarch granuloma. The disseminated small nodules over the peritoneum were incidentally discovered at operation for cholelithiasis, when she was misdiagnosed as carcinomatosis peritonei. Histological observations revealed a characteristic finding of tuberculoid granuloma with caseous necrosis, a rather rare histological type of cornstarch granuloma. Polarized light microscopic examination of biopsy specimens is particularly important for the diagnosis. We emphasize that cornstarch granuloma should once be considered when tuberculoid or unknown abdominal granuloma are observed in patients with history of abdominal surgery.

Female↗
PubMed1983

Long-term survival in a case of hepatocellular carcinoma.

A patient with an unresectable hepatocellular carcinoma (HCC) who survived without active treatment 3 years and 8 months after histological diagnosis is described. The size of the liver, which was already quite huge at the time of diagnosis, changed little during the entire clinical observation. However, 2 months before death, his condition deteriorated rapidly following gastrointestinal bleeding due to the direct invasion of the stomach by HCC. A critical reason for the unusually long-term survival of the patient may stem from the facts that a well-differentiated and bile-producing HCC was extent in most encapsulated-tumor tissues and that liver cirrhosis was not present.

Carcinoma, Hepatocellular↗
PubMed1983

Absence of Kupffer cells in carcinogen induced liver hyperplastic nodules: demonstration by intravenous injection of indian ink.

Absence of Kupffer cells in rat liver hyperplastic nodules induced by a chemical carcinogen was demonstrated by intravenous injection of indian ink. Hyperplastic nodules appeared 4 weeks after diethylnitrosamine (DEN) was administered, and the nodules continued growing and became eosinophilic hyperplastic nodules after 5 to 6 weeks. After intravenous injection of indian ink, hyperplastic nodules were observed as carbon-free white nodules, which were macroscopically distinguishable from the black surrounding tissue. As observed by light microscopy, Kupffer cells were absent in hyperplastic nodules in contrast to being present in the surrounding tissue. Scanning electron microscopy confirmed these findings and furthermore revealed that the sinusoidal endothelium of hyperplastic nodules had no fenestrae. Injection of indian ink is a useful method for delineation and enucleation of hyperplastic nodules in the study of morphological and chemical changes of nodules.

Animals↗
PubMed1982

Electron microscopy of liver lesions in primary biliary cirrhosis. I. Intrahepatic bile duct oncocytes.

Liver biopsy specimens from a primary biliary cirrhosis (PBC) patient and two control patients with other biliary disorders were examined under the electron microscope, with special reference to intrahepatic bile ducts. The PBC patient had a bile duct with an 80 micrometers diameter that showed specific alterations in epithelial cells. These cells were termed oncocytes, and their main features were: the presence of a large number of swollen mitochondria with abnormal cristae, no mitochondrial bodies, small number of exocrine granules and an undulated nucleus with a large cytoplasm. The number of mitochondria per ultrathin-sectioned epithelial cell was greater by about 2 times in the oncocytic epithelial cells compared to the control cells. Fine fibrils and long-spacing collagens were present around the PBC bile duct. Periductal capillaries of the bile duct had multilayered basement membranes. These periductal changes may have induced the oncocytic changes in the epithelial cells. The basement membrane of the bile duct was meandrous and often disrupted, but not multilayered. Many lymphocytes and macrophages infiltrated among the epithelial cells.

Adult↗
PubMed1982

Langerhans cells among bile duct epithelial cells in chronic liver disease.

Langerhans cells were found among bile duct epithelial cells in a biopsy specimen from a patient with chronic liver disease showing cholangitic features. The bile duct was 90 micrometers in diameter and surrounded with mononuclear cell infiltration. Under the electron microscope, the cell had a clear cytoplasm and contained a deeply indented nucleus, a centriole, well-developed Golgi complexes and many rod-shaped bodies (Birbeck granules).

Adult↗
PubMed1982

Electron microscopy of liver lesions in primary biliary cirrhosis. II. A bile duct with chronic non-suppurative destructive cholangitis.

An 80 micrometers bile duct with typical features of chronic non-suppurative destructive cholangitis was examined by electron microscopy. Many inflammatory cells, including lymphocytes, macrophages and plasma cells infiltrated among epithelial cells of the bile duct. Epithelial cells were compressed and deformed by infiltrating lymphocytes. These lymphocytes were in contact with epithelial cells at small points or large areas. The intercellular distance was about 10 or 20 nm at the contact areas. The mode of contact and intercellular distance coincided with the results of in vitro experiments on lymphocyte cytotoxicity against target cells. Some epithelial cells in contact with lymphocytes showed degenerative changes. Necrotic changes were observed in bile duct epithelial cells undergoing emperipolesis. The invading lymphocyte in the epithelial cell had osmiophilic substances on the surface. These sites of emperipolesis seem to be the areas of lymphocyte cytotoxicity against epithelial cells.

Basement Membrane↗
PubMed1979

Biochemical and morphological study on hepatotoxicity of azathioprine in rat.

Sprague-Dawley rats given azathioprine in the diet for 3 to 4 weeks developed severe liver damage. Elevations of serum alkaline phosphatase and gamma-glutamyl transpeptidase activities were associated with increased hepatic glucose 6-phosphate dehydrogenase levels and decreased liver glucose 6-phosphatase activities, i.e., conditions which were commonly observed in various hepatotoxin-induced liver injuries. Light and electron microscopic observations revealed centrolobular necrosis with large scars and the proliferation of the mitochondria and rough endoplasmic reticulum. This model could be used to study the mechanisms of azathioprine-induced liver damage and its prevention.

Animals↗
PubMedDate not supplied

Ultrastructural immunocytochemical analysis of lymphocytes infiltrating bile duct epithelia in primary biliary cirrhosis.

Subpopulations of lymphocytes in portal areas, especially infiltrating bile duct epithelia were analyzed by light and electron microscopy using indirect peroxidase-labeled antibody method and monoclonal antibodies against pan-T (Leu 1), cytotoxic/suppressor T (Leu 2a), helper/inducer T (Leu 3a) and natural killer/K (Leu 7) and suppressor T (Leu 15) cells in liver biopsy specimens from four patients with primary biliary cirrhosis. Bile ducts with chronic nonsuppurative destructive cholangitis were observed in two patients. Leu 1+ and Leu 2+ cells were frequently seen in intimate contact with epithelial ductal cells. The majority of intraepithelial cells possessing Leu 2a antigen did not react with anti-Leu 15 antibody. Leu 3a+ or Leu 7+ cells seldom infiltrated ductal epithelia. These findings indicate that the majority of intraepithelial lymphocytes in bile ducts most likely represent Leu 2a+15- cytotoxic T cells. By immunoelectron microscopy, Leu 1+ or Leu 2a+ lymphocytes often breached the basement membrane of bile ducts and were present within dilated intercellular spaces between biliary epithelial cells. Furthermore, they often formed sharp or broad contacts with the epithelial cells, and occasionally pseudopods projecting from the surfaces of Leu 2a+ cells extended into the epithelial cells. Most of Leu 2a+ lymphocytes contained little cytoplasm with few granules and a small Golgi apparatus. Such findings suggest that cytotoxic T cells may contribute to the pathogenesis of chronic nonsuppurative destructive cholangitis in primary biliary cirrhosis.

Adult↗
PubMedDate not supplied

Hepatocellular carcinoma: comparative study among precontrast, artery-dominant, and delayed-contrast phase images at ultrafast CT.

To evaluate the detectability of hepatocellular carcinoma (HCC) at artery-dominant phase and to compare it with that at precontrast and delayed-contrast phases, 34 patients with 109 HCCs were examined by ultrafast computed tomography (CT) using an incremental dynamic technique under single breath-holding. Images of three phases (precontrast, artery-dominant, and delayed) were compared with iodized-oil CT images. None of the lesions were detected only at precontrast phase. HCC detectability at the artery-dominant phase (87/109, 80%) was significantly superior to that at precontrast phase (32/109, 29%) (p < .01) and delayed-contrast phase (57/109, 52%) (p < .01). All 31 lesions missed at delayed-contrast phase were depicted at artery-dominant phase, while one lesion observed at delayed-contrast phase was missed at artery-dominant phase. Incremental dynamic CT at artery-dominant phase was suitable for the diagnosis of HCCs. Precontrast phase images were not necessary, although delayed-phase images were useful for the evaluation of tumor extension in some cases.

Aged↗