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Biomedical subjects

T Itoshima

Publications and source records attributed to T Itoshima.

At least 37 records · Page 2Linked to original sources
PubMed1990

Three-dimensional fine structure of the biliary tract: scanning electron microscopy of biliary casts.

The three-dimensional structure of the biliary tract was studied by scanning electron microscopy (SEM) of biliary casts. The replica of the biliary tract was successfully prepared by retrograde injection of low viscosity resin into the common bile duct. Bile canaliculi are intricate networks in which hexagonal and pentagonal meshworks are interconnected. Each hexagonal or pentagonal meshwork is on a plane, but adjoining meshworks are on different planes. Bile canalicular networks connect with bile ductules at the periphery of the portal tract. The intrahepatic bile duct showed considerable interspecies variation. The human bile duct has plexiform side branches and periductal sacculi, which are most numerous near the liver hilum and fewest in the smaller portal tracts. The hilar plexus and sacculi are present on opposite sides of the bile duct. The plexus formed at the bifurcation of the bile ducts exhibits a plane. Periductal sacculi were also observed in the monkey and pig bile ducts, particularly the latter, while rat bile ducts possess a peculiar portal bile ductular plexus situated between the portal tract and the surrounding liver parenchyma. No such structures were observed in either the dog or rabbit bile ducts. SEM of the biliary casts showed that the biliary tract was not a simple draining tube but had additional structures, such as periductal sacculi and plexiform side branches. These structures, together with the peribiliary vascular plexus, may be implicated in the modification of bile.

Biliary Tract↗
PubMed1989

Hepatitis B virus markers in patients with schistosomiasis, liver cirrhosis and hepatocellular carcinoma in Khartoum, Sudan.

Markers of hepatitis A and B virus were tested in 88 adult Sudanese subjects in Khartoum, Sudan. The subjects consisted of 25 control hospitalized patients, 21 volunteer blood donors, 23 patients with hepatosplenic schistosomiasis, 13 patients with liver cirrhosis and 6 patients with hepatocellular carcinoma (HCC). Antibody to hepatitis A virus was detected in 96% of the total. Hepatitis B surface antigen (HBsAg) was positive in 4, 24, 22, 31, and 67% of the subject groups, respectively. Antibody against hepatitis B core antigen (HBcAb) of undiluted serum was positive in 60, 57, 65, 77 and 83%, and there was no difference in incidence among the groups. It was positive in 200X diluted serum in 4, 24, 17, 23 and 60%. HBsAg and HBcAb (200X) were detected more often in HCC patients than in the control subjects (p less than 0.01). Hepatitis B virus is an important factor in the etiology of HCC in the Sudan.

Adult↗
PubMed1988

Phalloidin-induced alterations of bile canaliculi.

Phalloidin, a toxin from the plant Amanita phalloides, irreversibly polymerizes actin filaments and causes cholestasis. Three-dimensional structural changes induced by phalloidin in the bile canaliculi and the intra-acinar localization of these changes were studied in the rat liver by scanning and transmission electron microscopy. After 3 days of treatment, canalicular changes appeared mainly in zones 2 and 3 of Rappaport's acinus, but after 7 days of treatment changes occurred in bile canaliculi of the whole acinus. The changes in the bile canaliculi included tortuosity, saccular dilatation, loss of microvilli, bleb formation and elongation of canalicular side branches. Some side branches extended near to Disse's space, leaving only a thin cytoplasmic rim between the canalicular lumen and Disse's space. Kupffer cells were occasionally situated near such extended bile canaliculi and protruded their processes into the hepatic cord. These results suggest that bile canaliculi in zone 3 are more susceptible to phalloidin toxicity than those in zone 1 and that biliary constituents may leak from such altered bile canaliculi.

Animals↗
PubMed1987

Photodynamic therapy of rat liver cancer: protection of the normal liver by indocyanine green.

The application of photodynamic therapy (PDT) to hepatocellular carcinoma (HCC) has been difficult because hematoporphyrin derivatives (HpD) accumulate not only in cancer cells but also in normal hepatocytes and, hence, laser irradiation causes injuries in both tissues. Protection of the normal liver tissue from laser phototoxicity was demonstrated using indocyanine green (ICG) as a protective agent. In vitro, argon laser irradiation decolored the green tint of ICG much faster in solutions containing HpD than those without, suggesting that ICG captured singlet oxygen from HpD. Degeneration of Change hepatocytes induced by HpD and laser irradiation was prevented by an addition of ICG into the medium. In vivo, laser irradiation of the rat liver surface caused hyperemia when HpD was injected two days before, while the hyperemia was much milder in rats additionally receiving ICG injection 10 minutes before the irradiation. ICG injected into rat HCC accumulated only in the normal liver tissue. Laser irradiation of rat HCC preinjected with both HpD and ICG destroyed only the cancer tissue, while the surrounding liver tissue was preserved. Both in vitro and in vivo results suggest that ICG has a scavenger effect against excited oxygen and it might be used as a protective agent in PDT of HCC.

Animals↗
PubMed1987

Follow-up study of 582 liver cirrhosis patients for 26 years in Japan.

A long-term follow-up study of liver cirrhosis (LC) was performed in 582 patients diagnosed by peritoneoscopy and liver biopsy in the 26 years from 1958 to 1984. The etiology of LC consisted of hepatitis B virus (HBV) in 21%, alcoholic in 39% and cryptogenic in 39%. Fifty-nine percent of patients had died. Causes of death were hepatocellular carcinoma (HCC 44%), liver failure (30%), rupture of esophageal varices (14%), gastrointestinal bleeding (4%) and non-liver-related causes (8%). HCC accounted for increasing percentages (68%) since 1980. In all groups classified by the etiology, the causes of death had the same order in incidence. The age of onset of LC increased by 10 years from 42 to 52 years old and the age of death by 15 years from 43 to 58 in the 26-year period. The cumulative survival rate improved over the period. The 50% survival year was 7.9 in total patients, and 7.0, 8.5 and 10.0 in the three periods 1958-64, 1965-74 and 1975-84, respectively. It was 9.5, 6.3 and 9.8 in HBV, alcoholic and cryptogenic, respectively. LC patients survived 40-44% of the life expectancy of the general population in Japan in all age groups. Cox's multiregression life-table method selected three important prognostic factors from 7 parameters: a poor prognosis with a history of heavy alcohol consumption and old age at onset, and a better prognosis with recent onset.

Actuarial Analysis↗
PubMed1987

Treatment of hairy cell leukemia with alpha-interferon and splenectomy.

A typical case of hairy cell leukemia, very rare in Japan, is described. The biological characteristics of the disease and histological features of liver and spleen are also reported. Treatment with alpha-interferon and splenectomy was successfully performed, and the patient is now in good health.

Follow-Up Studies↗
PubMed1986

Injurious effects of ethanol on rat Kupffer cells.

The effects of ethanol on rat Kupffer cells were studied functionally and morphologically. Eight g ethanol per kg body weight per day was intragastrically administered to rats for 7 days. An isocaloric glucose solution was administered to control rats. The phagocytic activity of the reticuloendothelial system was measured by the carbon clearance method (57 mg carbon particles per kg body weight) on the 7th day. Kupffer cells having phagocytized carbon particles were counted under the light microscope. Kupffer cells were also observed by scanning electron microscopy. Both the carbon clearance and Kupffer cell number were lower in ethanol-administered rats (32 +/- 8 X 10(-4) mg/ml; 0.6 +/- 0.3/0.01 mm2 liver lobule) as compared to control rats (63 +/- 15; 3.1 +/- 1.0). Microvilli and filopodia of Kupffer cells were fewer in ethanol-administered rats than in control rats. Carbon clearance correlated with Kupffer cell number per 0.01 mm2 liver lobule and liver weight. These results suggest that the decrease in carbon clearance induced by ethanol is due mainly to the decrease in Kupffer cell number and partly to the decrease in Kupffer cell activity as demonstrated by the disappearance of microvilli and filopodia.

Animals↗
PubMed1985

Cavernous structures composed of hepatocytes in experimentally induced hepatocellular carcinoma.

Cavernous structures composed of hepatocytes were observed for the first time in trabecular-patterned hepatocellular carcinomas by light, scanning and transmission electron microscopy. The carcinomas were induced by a single dose of diethylnitrosamine combined with subsequent administrations of 2-acetylaminofluorene and partial hepatectomy. The cavernous structures had numerous cavities walled by flat hepatocytes. In the cavities, dendritic hepatocytes, connected with each other by their long and slender processes, formed a network and were attached to the fenestrated sinusoidal endothelium via intercellular spaces between the flat hepatocytes. Dendritic hepatocytes had smooth surfaces, prominent nucleoli, decreased glycogen, and well organized cisternae. Dilated bile canaliculi were sometimes seen among flat and dendritic cells. Dendritic cells showed more morphological dearrangement than flat cells. Blood cells were observed in the cavities. Kupffer cells were not seen in the sinusoids among the cavernous structures. The cavernous structures in the hepatocellular carcinomas resembled the hepatocyte arrangement in fetal liver in which intercellular spaces of hepatocytes are extremely widened.

Animals↗
PubMed1985

Electron microscopy of granulomatous lesions of the liver in primary biliary cirrhosis.

Three granulomas in the portal tract and 9 bile ducts with typical features of chronic non-suppurative destructive cholangitis (CNSDC) associated with dispersed epithelioid cells were examined by electron microscopy in 10 patients with primary biliary cirrhosis (PBC). Vesicular epithelioid cells, which contained numerous single-membrane bound vesicles, predominated in the granulomas. On the other hand, immature epithelioid cells and activated macrophages were more often observed near epithelial cells of the bile ducts with CNSDC than in the granulomas. These macrophages seemed to be activated by epithelial cells of the bile ducts and develop into epithelioid cells. Honeycomb-like membranous labyrinths containing electron dense substances were frequently observed in epithelioid cells and were likely a special form of phagosome. The substances in the labyrinths seemed to be derived from organellae of necrotic cells and extracellular interstitial tissues. Subplasmalemmal linear densities (SPLD) were observed at the cytoplasmic boundary and at intracytoplasmic membranous labyrinth. The roles of SPLD were discussed.

Epithelium↗
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↗
PubMed1985

Peritoneoscopy of alcoholic liver cirrhosis in comparison with non-alcoholic liver cirrhosis.

Peritoneoscopic findings of 39 patients with alcoholic liver cirrhosis (ALC) were compared with those of 95 patients with non-alcoholic liver cirrhosis (NALC). They were selected from 245 patients with liver cirrhosis subjected to peritoneoscopy in the 7 year period from 1975 to 1981. Out of the 95 NALC patients, 24 had hepatitis B surface antigen. The ALC patients had nodules which varied in size (61%), large depressions (69%), and a markedly rounded edge of the liver (33%) more often than NALC patients (18, 43 and 3%, respectively). Nodularity differed between the right and left lobes in ALC (41%) more often than in NALC (16%). Interstitial reddish markings and patchy nodules were, however, more frequent in NALC (51 and 28%, respectively) than in ALC (8 and 5%, respectively). Lymphatic vesicles were observed both in ALC (85%) and NALC (78%). In conclusion, the peritoneoscopic features which suggested ALC were the coexistence of nodules of various sizes, large depressions and a markedly dull edge of the liver. Interstitial reddish markings and patchy nodules were more indicative of NALC than ALC.

Adult↗
PubMed1985

Comparison of estimation methods of liver maximum removal rate of indocyanine green.

Three linear plots by which the liver's maximum removal rate (Rmax) of indocyanine green (ICG) and the Michaelis constant (Km) can be calculated were compared in a microcomputer simulation study. The widely-used Lineweaver-Burk plot (1/V vs. 1/S; V, ICG initial removal rate (mg/kg/min); S, ICG loading dose (mg/kg] presented the greatest bias and variance. There was no remarkable difference in bias between the S/V vs. S plot and the V vs. V/S plot, but the latter possessed a smaller variance. Therefore, the V vs. V/S plot was considered the best for estimating Rmax. The best combination of three ICG loading doses was 0.5, 2, and 5 mg/kg. This combination was selected by comparison of the Rmax estimated from three points with that estimated from six points (0.5, 1, 2, 3, 4 and 5 mg/kg).

Humans↗
PubMed1985

Evaluation of Talbot's safety zone of infusion volume and osmolality in infusion therapy for decompensated liver cirrhosis.

Problems with infusion therapy for correcting fluid and sodium imbalance in decompensated liver cirrhosis (DLC) were investigated by establishing the safety zone of Talbot et al. for parenteral fluid therapy in 4 DLC patients infused with over 900 ml of fluid each day for at least 9 days. The safety zone was different in each case. The safe infusion volume decreased and the safe electrolyte concentration shifted to a lower osmolality when there was ascites with renal failure than ascites without renal failure. Infusion therapy was performed without deterioration of the water and sodium balance in those patients whose infusion volume and fluid osmolality were in the safety zone. In contrast, ascites retention increased and peripheral edema appeared in patients whose infusion volume and osmolality were out of the safety zone. Therefore, the safety zone should be determined repeatedly during infusion therapy.

Aged↗
PubMed1985

Comparative diagnosis of alcoholic liver diseases by multivariate and histological analysis.

Sixty-seven cases of alcoholic liver disease were histologically classified into 4 groups: alcoholic liver cirrhosis (ALC), alcoholic hepatitis (AH), alcoholic liver fibrosis (ALF) and alcoholic fatty liver (AFL). They were statistically reclassified by the likelihood method using age, total alcohol intake, hepatomegaly and 12 liver function tests. A score table for likely diagnosis was constructed from the incidences of each range. The cases were re-evaluated using the score table, with an overall correct diagnosis rate of 73%. The best combination of 5 parameters included the indocyanine green plasma disappearance rate, total alcohol intake, cholesterol, choline esterase and glutamic oxaloacetic transaminase/glutamic pyruvic transaminase ratio. A correct diagnosis rate of 75% was attained using these 5 parameters, and 94% of patients were correctly diagnosed by the first or the second likelihood diagnosis. Differential diagnosis of alcoholic liver diseases was easily and confidently obtained with the likelihood score table.

Adult↗
PubMed1984

A monomeric methyl and hydroxypropyl methacrylate injection medium and its utility in casting blood capillaries and liver bile canaliculi for scanning electron microscopy.

A mixture of 50-60% monomeric methyl methacrylate and 40-50% monomeric 2-hydroxypropyl methacrylate was supplemented with 1.5% benzoyl peroxide (catalyst) and 1.5% N,N-dimethylaniline (accelerator) and injected into glutaraldehyde-perfusion fixed rat hypophyseal and other endocrine organ blood vessels and biliary tracts. This injection medium rapidly polymerized at room temperature and did not require partial polymerization prior to injection. Good casts of blood vessels, including the hypophyseal capillaries, were obtained for scanning electron microscopy. The monomeric methacrylate medium possesses a great advantage over previous ones, as its fluidity enables the casting of very fine vessels such as bile canaliculi. In the case of non-fixed tissues, the monomeric methacrylate medium should be injected carefully, as it is toxic and destructive to the vessels.

Acrylates↗