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T Itoshima

Publications and source records attributed to T Itoshima.

14 recordsLinked to original sources
PubMed1992

Proliferation of collagen fibrils and Ito cells in the liver after Japanese sake administration in undernourished rats as demonstrated by scanning electron microscopy.

Intralobular fibrosis of the liver was induced in undernourished rats by administering Japanese sake for 12 days. Control rats administered the equivalent calories with glucose solutions did not show any fibrosis. In the sake group, Ito cells were increased and often clustered under the scanning electron microscope (SEM). Many collagen fibrils 0.1 microns in diameter twisted around Ito cells which had numerous microvillous projections. On the contrary, fibrils were not increased and Ito cells had rather smooth surfaces in the control group. The number of Ito cells counted under the SEM at 500 magnifications was increased in the sake group (mean +/- standard deviation; 70 +/- 23/mm2) as compared to the control group (44 +/- 9; P less than 0.01). The fact that Ito cells had proliferated and were tangled with collagen fibrils in the sake group was demonstrated three-dimensionally by SEM.

Animals↗
PubMed1991

Observation of microvascular casts of human hepatocellular carcinoma by scanning electron microscopy.

The microcirculation of hepatocellular carcinomas (HCCs) and surrounding tissue was observed three-dimensionally by scanning electron microscopy of vascular casts made from 10 livers at autopsy. The livers were perfusion-washed and cast with resin through both the hepatic artery and portal vein branches. The HCCs observed ranged from several millimeters to 3 cm in size. A vascular plexus proliferated around the HCC nodules in all cases. Both portal vein and hepatic artery branches proliferated markedly to form the plexus in 5 patients. These vessels communicated directly with the blood sinuses of the HCCs as feeder vessels. HCC cells replaced normal cells while maintaining the liver's trabecular structure in 2 cases. At the borders of these HCCs, there was direct communication between the hepatic sinusoids and the tumor blood sinuses. Efferent vessels of the tumors were generally difficult to identify but vessels resembling hepatic vein branches were detected in one 4-mm HCC nodule after microdissection. Thus, HCC was demonstrated to be supplied not only by the hepatic artery but also by the portal vein and hepatic sinusoids. This may be one of the reasons why cancer cells survive in the tumor margins and daughter nodules after transcatheter arterial embolization of HCC.

Adult↗
PubMed1991

Experimental liver cysts induced by 2-acetylaminofluorene.

Liver cyst formation was studied serially in an experimental model in which rats were fed a diet containing 0.02% 2-acetylaminofluorene, a carcinogen, for 6 weeks, followed by a normal diet for 42 weeks. Cysts appeared in the portal tracts at the 12th week, by which time the intrahepatic bile ducts had also proliferated and dilated. Some of the dilated bile ducts were cavernous or multicystic and appeared to represent a transitional form between the bile duct dilation and cystic formation. After 20 weeks cysts were observed in the majority of rats. The number and the size of cysts in the liver increased with time; after 40 weeks, there were up to 20 cysts as large as 15 mm in diameter. Carcinoma or cirrhosis did not develop in this model. Indocyanine green dye injected intravenously did not accumulate in the cysts, which denies the possibility of communication between cysts and the bile duct. Scanning electron microscopy demonstrated that the cysts were composed of a few intercommunicating cavities and were lined with epithelial cells similar to those of the intrahepatic bile duct, which had numerous microvilli and a central cilium. These observations suggest that liver cysts originate in the bile duct.

2-Acetylaminofluorene↗
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↗
PubMed1979

Scanning electron microscopy of the parimarginal cavernous sinus plexus of the human spleen.

The perifolicular region of the human spleen was studied under the scanning electron microscope. The marginal zone 10 to 50 micron in width was located around the white pulp, and was composed of concentrically arranged reticulum cell networks and intervening lymphocytes, red blood cells and macrophages. The cavernous sinuses 10-150 micron in width were situated between the marginal zone and the red pulp, and were lined by thin, flat endothelia. The perimarginal cavernous sinuses communicated with one another through narrow canals and formed a plexus. Transmural passages of lymphocytes were noted on the side of the white pulp. The perimarginal cavernous sinus plexus was also in communication with the interspaces between reticulum cells in the marginal zone. The human perimarginal cavernous sinus plexus appears to correspond to the marginal sinus in rat and rabbit spleens.

Aged↗
PubMed1978

Cleaning of scanning electron microscope specimens by puncture perfusion.

Puncture perfusion method was described for elimination of blood and tissue fluid in the scanning electron microscope specimens. It was also demonstrated that the puncture perfusion is of excellent use in cleaning the small samples including the human biopsy samples, which are hardly washed by the vascular cannulation.

Cytological Techniques↗
PubMed1977

Scanning electron microscopy of the bile ductule.

Scanning electron microscopy of a liver biopsy specimen from a patient 6 months after the onset of acute hepatitis revealed a normal appearing bile ductule. The bile ductule was 13 micron in outer diameter and 1.5-2.7 micron in inner diameter. The ductular lumen was surrounded by two ductular cells and ampullary dilated at the canalicular side. In the lumen, intracytoplasmic diverticles were observed with an orifice diameter of 0.9 micron. About 15 microvilli 0.4-0.6 micron in length and 0.1 micron in thickness were observed on 1 micron2 of luminal surface. The number of microvilli was calculated to be approximately 1,500 per ductular cell. A single cilium 0.15 micron in diameter at the base and 0.10 micron at the trunk, and 7-15 micron in length was found on each ductular cell. The cilium arose from a recess at the canalicular side of the ductular cell, and the free-end was on the bile-duct side. The cilia seemed to play an important role in bile flow to the duct. Sometimes between the ductular cells at the edge of the basal portion a cell was intercalated with thin processes. Such thin processes were not observed on ductular cells.

Adult↗
PubMed1977

Modified tannin-osmium conductive staining method for non-coated scanning electron microscope specimens. Its application to microdissection scanning electron microscopy of the spleen.

Supplement of guanidine hydrochloride to the original tannic acid solution of MURAKAMI (1973) eliminated, without debilitating the conductivity effect, the vexatious treatment with different amino-acids and sucrose in the previous method (MURAKAMI, 1974). The procedures and advantages of this simplified modification are described using human spleen samples; attempt was made to elucidate the structure of arterial terminals by dissecting the specimens under the scanning electron microscope.

Dissection↗
PubMed1976

A scanning electron microscopy of subcellular structures of the human hepatic cell.

Human liver specimens obtained by needle biopsy were extensively osmicated by the revised tannin-osmium method of MURAKAMI (1974) and cracked in air after critical point drying, to be observed in the scanning electron microscope. The fracture tended to occur along the membranous elements and exposed beautifully fractured faces of the hepatic cell. The nucleus of the hepatic cell was spherical. The nuclear pores were demonstrated as small pits 0.1 mu in diameter and their total occurrence in one nucleus was estimated to be 2,100. In the spongy framework resembling the endoplasmic reticulum, oval-shaped mitochondria and multivesicular tufts of the Golgi complex were observed. The nucleolus of the hepatic cell nucleus was noticed as a highlighted mass in the cloudy nucleoplasm.

Cell Nucleus↗
PubMed1976

Peritoneoscopic diagnosis of liver surface--using a new code number system--.

A new peritoneoscopic classification of liver surface using a three digit code was developed. The first digit represents the lobular change from normal structure to nodules. The second digit represents the size of the nodule and the internodular distance. The third digit represents the pathological findings, such as inflammation, degeneration, necrosis or regeneration. Furthermore, peritoneoscopic findings of necrosis of lobular size around the portal vein and patchy markings of the liver were presented. These findings were the most prominent in the course of hepatitis progression to cirrhosis.

Adult↗