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Y Nagato

Publications and source records attributed to Y Nagato.

At least 37 records · Page 2Linked to original sources
PubMed1993

Correlative light and electron microscopy of the same sections embedded in HPMA, Quetol 523 and MMA.

Semithin sections, cut from tissues stained with acid and basic dyes after embedding in 2-hydroxypropyl methacrylate, Quetol 523 and methyl methacrylate, showed cytoplasmic components at a high resolution by light microscopy. These same sections could then be viewed, after osmium tetroxide, uranyl and lead staining, by the electron microscope. These sections had a number of inherent advantages: they could be observed with a light microscope; they facilitated analysis of cellular structures in the identical sites, and they were frequently the optimum thickness to provide three-dimensional information. We clearly established the structural detail of this same-section correlative light-electron microscopy approach by showing that the coloured materials observed in such sections of cells followed the distribution of fine structures within the same sections as determined by electron microscopy. In some instances the fidelity of the correlation between the distribution of the coloured area and cytoplasmic components in identical cells of the same section revealed significant details which could not visualized in thin sections. This technique, therefore, provided a simple and useful solution to many problems that require the localization of cellular components in identical cells selected previously by light microscopy.

Animals↗
PubMed1993

Studies on thick sections of the nucleus of mouse Sertoli cells using an electron microscope operating at 300 kV.

Examination of the three-dimensional structure of the Sertoli cell nucleus from mouse testes was performed under a high voltage electron microscope operating at 300 kV. Using an en bloc staining method along with fixation by osmium tetroxide and embedding in a mixture of Quetol 651, NSA and MNA, the structures of the nucleus were stained at a high contrast and satisfactory preservation was achieved, thus allowing their study at a high resolution within thick sections. Nuclear components could be observed clearly in 2-3 microns-thick sections of embedded material. Typical three-dimensional configurations of nucleoli and associated bodies were indicated. Thick sections permitted the observation that two or three pernucleolar bodies are usually attached on each side of the nucleoli or form a triangular shape of different sizes of vacuolar structures within the bodies. Stereoscopic observations also revealed overlapping of perinucleolar bodies and nucleoli and suggested the complexity of the components of perinucleolar and intranucleolar chromatin.

Animals↗
PubMed1993

[Treatment of common bile duct stones by peroral cholangioscopy].

Endoscopic papillotomy (EPT) has become a popular form of treatment in managing common bile duct stones. But it may fail in difficult cases such as large stones of over 20 mm, confluence stones, and impacted stones. Over the past 5 years, our success rate in clearing the bile duct by conventional endoscopic techniques (mechanical lithotripsy) was about 90 per cent. Recently, we have performed electrohydraulic lithotripsy or laser lithotripsy with peroral cholangioscopy in these difficult cases. Complete clearance of the duct was obtained in all 23 patients who underwent peroral cholangioscopic lithotripsy. No complication occurred. In conclusion, peroral endoscopic treatment of common bile duct stones should be safe and effective.

Aged↗
PubMed1993

[Percutaneous ethanol injection (PEI) for small hepatocellular carcinoma].

Percutaneous ethanol injection (PEI) was applied to 162 lesions in 133 patients with hepatocellular carcinomas (HCC) 3 cm or less in diameter (small HCC) between Aug. 1983 and Apr. 1992. Histological findings in resected specimen for which PEI had previously been performed before surgery showed that PEI could completely necrotize an HCC of 32 mm in diameter. The antitumoral effect by PEI could correctly be evaluated by enhanced CT. The 1-, 3-, 5- and 7-year survival rates after PEI calculated by the Kaplan-Meier method were 95.9%, 60.5%, 36.9% and 21.7%, respectively. The survival rate of post-PEI patients with I or II grade in clinical stage was better than that of those with III. Recurrence occurred in hepatic areas different from the original lesion in 27.8% in one year and 63.6% in three years after PEI, rates quite similar to those of recurrence after surgical resection for HCCs of 3 cm or less in diameter. For such recurrence, PEI alone was then repeated in half of the 76 patients. Complications caused by PEI were not serious and did not necessitate intensive care. Because of its anti-tumor therapeutic effect and minimal damage to the liver, PEI might be considered a viable alternative to surgery for most patients with small HCC.

Carcinoma, Hepatocellular↗
PubMed1992

Vasculitis and pyrexia associated with superficial spreading gastric carcinoma.

A case of low-grade fever developing about a month before the discovery of gastric carcinoma is reported. No findings of infection or collagen disease were revealed. The fever continued for about 3 months, but promptly disappeared after surgical removal of the tumor. A superficial spreading mucosal carcinoma with minimal invasion to the submucosa was seen in the antrum, showing the features of poorly differentiated adenocarcinoma. In addition, unique venous inflammation was recognized beneath and around the neoplasm. Arteries and lymph vessels did not exhibit any inflammatory changes. It was presumed that the gastric carcinoma had induced phlebitis, which subsequently brought about the fever. As to the pathogenetic mechanism, it was suggested that a substance produced by the carcinoma cells flowed into nearby veins to induce the phlebitis.

Adenocarcinoma↗
PubMed1992

Staining of semithin tissue sections embedded in HPMA, quetol 523 and MMA.

Various tissues fixed in a mixture of formaldehyde and glutaraldehyde, and embedded in an improved 2-hydroxypropyl methacrylate mixture were employed for studying the fine structures of cells and tissues by light microscopy. The embedding mixture contained Quetol 523 and methyl methacrylate as a plasticizer without a cross-linker. The catalyst was QCU-1. The mixture had a low viscosity, was easy to handle and penetrated readily and completely into the specimen, producing a homogeneous block from which it was easy to cut sections of 1-2 microns in thickness. A wide variety of stains have been employed with such sections and those reported here are hematoxylin-eosin, Azan and PAS. There was excellent preservation of alkaline phosphatase activity. A method of poststaining immunoperoxidase labeling was also applied to the mouse pancreas and examples of staining with insulin are included.

Aminosalicylic Acid↗
PubMed1991

Histochemical demonstration of heavy metals in the hippocampal formation embedded in Quetol 523M.

To facilitate improvement of investigations on the distribution of mossy fibers in the hippocampal formation, a method is described using Timm's stained preparations after methacrylate embedding with the hydrophilic resin, Quetol 523M. Fixation with a mixture of formaldehyde and glutaraldehyde yielded satisfactory staining results and good structural preservation. During the course of histochemical experiments employing Timm's staining, examinations revealed that sulfide silver reaction products were consistently present in both the mossy fibers themselves and their terminals associated with the dendrites of pyramidal cells in tissue sections of 1-2 microns in thickness. The results obtained also revealed that variations of the mossy fiber system occurred in the neurological mutant mouse dreher (dr). The bundles of mossy fibers forming the intrapyramidal synaptic field may be considered to reflect genotype-dependent differences in the mutation. The present method is adequate for allowing the histochemical demonstration of mossy fibers and their giant boutons by light microscopy.

Animals↗
PubMed1991

Histological and morphometrical indicators for a biopsy diagnosis of well-differentiated hepatocellular carcinoma.

Among 597 patients with nodular hepatic lesions who underwent ultrasonically guided needle biopsy, 305 were histologically confirmed as having hepatocellular carcinoma, and 37 patients had borderline lesions. Histological reexamination was correlated with morphometrical analysis on selected cases of well-differentiated, microtrabecular hepatocellular carcinomas (n = 29), borderline lesion (n = 10), typical (mid-sized and macrotrabecular) hepatocellular carcinomas (n = 15) and cirrhotic liver tissue obtained from extranodular hepatic parenchyma of hepatocellular carcinoma patients (n = 47). Morphometrical analyses revealed that the mean cell size and nucleocytoplasmic ratio were most useful for distinguishing well-differentiated, microtrabecular hepatocellular carcinoma from cirrhosis. These two parameters were well correlated with nuclear density. The grade of nuclear density, therefore, seemed to be a convenient semiquantitative indicator for diagnosing well-differentiated hepatocellular carcinoma. A comparison between intranodular and extranodular hepatic tissues was particularly important for its assessment. It is concluded from the results that hepatic nodules presenting a nuclear density larger than two times that of controls could be classified into the overt hepatocellular carcinoma group. From the statistical aspect, the possibility of microtrabecular hepatocellular carcinoma should be considered when a nodule has a nuclear density exceeding 1.3 times that of the extranodular tissue.

Biopsy↗
PubMed1991

Correlative light and electron microscopic observations on ectopic neurons in the cerebellum of dreher mutant mouse.

The structure of ectopic neurons in the cerebellum of dreher mutant mouse was investigated by correlative light and electron microscopic observations. Tissue blocks were fixed in buffered aldehyde and embedded in a mixture of 2-hydroxypropyl methacrylate, Quetol 523, and methyl methacrylate. Sections at 0.4-0.5 microns in thickness were examined by electron microscopy after observation under a light microscope. By comparing the electron images with those of light microscopy in the same sites, the structures of ectopic cells were confirmed. Ectopic Purkinje cells were arranged with cell bodies that contained an oval, spherical or wrinkled nucleus without deep invagination and the thin layers of endoplasmic reticulum at the perinuclear regions. Granule cells were ectopically matured in the external granular layer and within the cluster at the cortical region. This method provides a useful procedure for understanding structures of the cerebellar neurons of the mutant.

Animals↗
PubMed1990

Histological features and clinical course of large regenerative nodules: evaluation of their precancerous potentiality.

Seventeen patients with cirrhosis and histologically defined, ultrasonically detected, large regenerative nodules of the liver were followed without treatment for more than 1 yr (range = 13 to 51 mo). During the follow-up period, none of the nodules were demonstrated sonographically to have enlarged. Computed tomography and/or hepatic angiography were also performed in 14 patients, but there was no evidence of malignant transformation in these lesions. None of the 17 patients showed acute elevation of serum alpha-fetoprotein levels. Furthermore, four nodules became undetectable by these imaging procedures. Follow-up biopsy performed in seven patients revealed no significant histological changes from the first biopsy sample. However, HCCs developed apart from these large regenerative nodules in four patients. These HCCs suddenly appeared and did not seem to have been derived from preexisting large regenerative nodules. From these observations, it was not possible to regard a large regenerative nodule having no cytological atypia as a high-potential premalignant lesion. Their precancerous potentiality needs to be compared with that of ordinary pseudolobules.

Angiography↗
PubMed1990

Staining of intestinal goblet cells with ruthenium red in semithin sections.

For a correlative light and electron microscopy of intestinal goblet cells, postembedding staining with ruthenium red (RR) was performed in epoxy-embedded sections. Tissue blocks were fixed in buffered aldehyde and embedded in a mixture of Quetol 651, nonenyl succinic anhydride (NSA), methyl nadic anhydride (MNA), and DMP-30. Sections at 0.4-0.5 micron in thickness were mounted on grids and were treated with an aqueous solution of RR followed by osmium tetroxide, uranyl acetate and lead citrate. Postembedding staining of epoxy sections revealed the interaction between RR and anionic groups by both light and electron microscopy. Light and electron microscopic observation of identical sites in semithin sections was successful for the correlations of colored reaction with electron density.

Animals↗
PubMed1989

Biopsy diagnosis of well-differentiated hepatocellular carcinoma based on new morphologic criteria.

Nodular hepatic lesions detected in 123 patients with chronic liver diseases were subjected to ultrasonically guided needle biopsy. Of these, 94 cases were diagnosed as hepatocellular carcinoma of a moderately or poorly differentiated type with classical histologic features of hepatocellular carcinoma. In 14 cases in whom hepatocytes had minimal atypical changes and were mostly of normotrabecular arrangement (one to two cells thick), a diagnosis of well-differentiated hepatocellular carcinoma was made on the basis of the following three histologic criteria: nuclear crowding, increased cytoplasmic basophilia and microacinar formation. The nodules which showed two or more of these findings were diagnosed as well-differentiated HCC. The diagnoses of these 14 cases were subsequently confirmed by clinical course, histology in the resected specimen and/or autopsy findings. The nodules that presented similar but equivocal changes were arbitrarily categorized as borderline lesions (five cases). The nodules showing the findings almost identical with those of pseudolobules were regarded as benign, large regenerative nodules (nine cases). The remaining one case had a hemangioma. Thus, these three histologic criteria proved to be useful in the biopsy diagnosis of nodular hepatic lesions, with certain limitations. Additionally, the majority of large regenerative nodules, borderline lesions and well-differentiated HCCs were found to be smaller than 2 cm.

Biopsy, Needle↗
PubMed1989

Use of semithin sections embedded in a water-miscible methacrylate for light microscopy of central nerve tissues.

Semithin sections embedded in water-miscible methacrylates were used for the study of fine structures of cells and tissues in the central nervous system by light microscopy instead of the conventional paraffin sections. This method used a water-miscible methacrylate mixture consisting of 2-hydroxypropyl methacrylate (HPMA), Quetol 523 and methyl methacrylate (MMA) as an embedding medium. The mixture had a low viscosity, was easy to handle and penetrated readily and completely into the specimen, producing a homogenous block from which it was easy to make sections 1.5 microns thick. Staining could be localized far more precisely in these sections than in paraffin sections owing to the thickness of the semithin sections and to the excellent structural preservation of cellular components.

Acrylates↗
PubMed1986

PAS staining of eosinophils in semi-thin sections of bone marrow embedded in glycol methacrylate.

The usual periodic acid-Schiff (PAS) reaction of glycosaminoglycans is applicable to paraffin embedded material. A modification for water-miscible methacrylate embedded tissue suitable for correlative light and electron microscopic studies, which makes it possible to find the same stained cell in a semi-thin tissue section, is described. Eosinophil leukocytes in semi-thin sections from bone marrow were verified by electron microscopy after staining with the PAS reaction. Immature eosinophil leukocyte granules reacted with and without previous salivary treatment. This method facilitates the search for localization of glycosaminoglycans in scattered blood cells.

Animals↗
PubMed1985

Localization of periodate-Schiff reactive glycosaminoglycans in semi-thin sections embedded in GMA-Quetol 523-MMA--application of a method for correlative light and electron microscopy of identical sites.

A correlative light and electron microscope method in which semi-thin sections of embedded tissue were treated with periodate acid and Schiff's reagent (PAS) was used to determine the precise localization of PAS reactive substance. Small blocks of tissue specimens were fixed with aldehyde mixtures. After dehydration, the blocks were embedded in a modified mixture of glycol methacrylate (GMA), Quetol 523, methyl methacrylate (MMA) and QCU-1. Semi-thin sections, 0.2-0.3 micron thick, were stained by the PAS reaction, followed by counterstaining with hematoxylin if necessary. It was found that PAS reaction products representing the specific sites for glycosaminoglycans and glycoproteins were seen in both light and electron microscopy. In the control experiments the specificity of the reaction was confirmed. The granules of goblet cells were well stained and contrasted by the reaction materials. The basement membrane and the microvilli of the epithelial cells appeared as the staining layer. In the spermatocytes the reaction products were demonstrated in the Golgi apparatus, acrosomal vesicles and head cap. The results indicated that the PAS deposits became electron dense when the embedding matrix had a low electron scattering property. Using this method of preparing semi-thin sections, a comparative study of the localization of glycosaminoglycans was performed.

Animals↗