bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low-Viscosity, Intermediate-Viscosity, and High-Viscosity Alternatives in the Family of Epoxy Resin Embedding Media...... Your Choice
Authors: Mascorro Joe A. , Kirby Gerald S. 
Published: June 2020

The epoxy resins have been successfull as embedding media because of their demonstrated ability to preserve morphological detail, minimally extract cell components, infiltrate tissues, and polymerize uniformly without inducing shrinkage artifacts. These embedding media also produce blocks with favorable sectioning and staining qualities and sections capable of withstanding the heat and vacuum encountered in the electron microscope column. Many epoxy resins are available today and several have been evaluated in past works. The versatility of these resins allows them to be “matched” with various embedding media components (ie., DDSA, NMA, NSA, DMP-30, DMAE) in order to design a final embedding product with a predetermined viscosity. This work evaluates the resins Embed 812, LX112, Polybed 812, Eponate 12, and the traditional Epon 812 in “low”, “intermediate”, or “high” viscosity alternatives formulated with different combinations of anhydrides and catalysts.The anhydride NSA and the tertiary amine catalyst DMAE are more fluid and less viscous than their counterparts DDSA and DMP-30.
Correlated Confocal and Intermediate Voltage Electron Microscopy of Myofibrillogenesis in Muscle Cells: Methods and Preliminary Results
Authors: Ishikawa Harunori , Peachey Lee D. , Schultheiss Thomas , Holtzer Howard 
Published: June 2020

Immunofluorescence studies have helped to elucidate the process of molecular assembly into cross-striated myofibrils in cultured cardiac and skeletal muscle cells by localizing accurately identified proteins. However, our understanding of how such immunofluorescence images are related to fine structural organization is limited. High and intermediate voltage electron microscopes can image relatively thick specimens, including whole cells, and confocal scanning laser fluorescence microscopy provides thin optical section images of similarly thick specimens. It seemed natural for us to combine these two approaches in a correlated electron and light microscopic analysis of myofibrillogenesis in cultured cardiac muscle cells.Cardiac myocytes from 7-9 day chick embryos, cultured for 3-5 days on glass coverslips carrying gold EM grids covered with formvar/carbon films, were fixed with 2% formaldehyde for 3 min., permeabilized with 5% Triton for 30 min., and stained with two antibodies conjugated with FITC and rhodamine. These specimens were first observed by epi-fluorescence and then by confocal laser scanning microscopy (Sarastro, Stockholm, SWEDEN).
Use of Thick Histochemical Preparations, Whole Mount Cultured Cells or Thick Sections from Embedded Tissues, for Three-Dimensional Observation by Ultrahigh Voltage Electron Microscopy
Authors: Nagata Tetsuji , Usuda Nobuteru , Ma Hongjun 
Published: June 2020

We have observed very thick biological specimens, both whole mount cultured cells and thick sections from embedded tissues, which were stained with histochemical reactions for specific cell organelles, by means of high or ultrahigh voltage electron microscopy (UHVEM).Thick histochemical specimens, both whole mount cultured cells and semithin sections from embedded tissues were used. Two cell strains in culture, one established CHO-K1 cell line and the other primary culture cells of adult Wistar rat hepatocytes were used. Culture cells were seeded onto formval coated gold meshes and incubated in CO2 incubator. CHO-K1 cells were cultured in Ham’s F12 medium containing HRP (1 mg/ml), while rat hepatocytes were in L-15 medium containing Clofibrate (0.2 mM). The cultured cells were stained with DAB reaction, dried in a critical point dryer (Hitachi HCP-1). Thick sections (0.2-1.0 μm) from DEHP fed rat livers, fixed in 2.5% glutaraldehyde, stained with DAB reaction, postfixed in 1% osmium tetroxide and embedded in Epon, or semithin Epon sections (0.2μm) from the pancreases of 3H-thymidine or 3H-uridine injected mice, fixed doubly, radioautographed with Sakura NR-H2 emulsion.
Ultrastructural Study of a differentiating human colon carcinoma cell line
Authors: Polak-Charcon Sylvie , Hekmati Mehrdad , Ben Shaul Yehuda 
Published: June 2020

The epithelium of normal human colon mucosa “in vivo” exhibits a gradual pattern of differentiation as undifferentiated stem cells from the base of the crypt of “lieberkuhn” rapidly divide, differentiate and migrate toward the free surface. The major differentiated cell type of the intestine observed are: absorptive cells displaying brush border, goblet cells containing mucous granules, Paneth and endocrine cells containing dense secretory granules. These different cell types are also found in the intestine of the 13-14 week old embryo.We present here morphological evidence showing that HT29, an adenocarcinoma of the human colon cell line, can differentiate into various cell types by changing the growth and culture conditions and mimic morphological changes found during development of the intestine in the human embryo.HT29 cells grown in tissue-culture dishes in DMEM and 10% FCS form at late confluence a multilayer of morphologically undifferentiated cell culture covered with irregular microvilli, and devoid of tight junctions (Figs 1-3).
Morphologic alteration in the muscles of patients with hypokalemic periodic paralysis or myopathy
Authors: Shimizu T. , Muranaka Y. , Ohta I. , Honda N. 
Published: June 2020

There have been many reports on ultrastructural alterations in muscles of hypokalemic periodic paralysis (hpp) and hypokalemic myopathy(hm). It is stressed in those reports that tubular structures such as tubular aggregates are usually to be found in hpp as a characteristic feature, but not in hm. We analyzed the histological differences between hpp and hm, comparing their clinical manifestations and morphologic changes in muscles. Materials analyzed were biopsied muscles from 18 patients which showed muscular symptoms due to hypokalemia. The muscle specimens were obtained by means of biopsy from quadriceps muscle and fixed with 2% glutaraldehyde (pH 7.4) and analyzed by ordinary method and modified Golgimethod. The ultrathin section were examined in JEOL 200CX transmission electron microscopy.Electron microscopic examinations disclosed dilated t-system and terminal cistern of sarcoplasmic reticulum (SR)(Fig 1), and an unique structure like “sixad” was occasionally observed in some specimens (Fig 2). Tubular aggregates (Fig 3) and honeycomb structure (Fig 4) were also common characteristic structures in all cases. These ultrastructural changes were common in both the hypokalemic periodic paralysis and the hypokalemic myopathy, regardless of the time of biopsy or the duration of hypokalemia suffered.
Ultrastructural Changes in Oral Mucosa After Topical Application of Nicotine
Authors: Laffoon J.E. , Kremer M.J. , Squier C.A. , Lesch C.A. 
Published: June 2020

The potential health risks involved with the use of smokeless tobacco have been well documented. This habit involves the placement of tobacco containing 0.2-8.0% nicotine directly on the oral mucosa. It is possible that such levels of nicotine may have a directly injurious effect; we have examined this using pig oral mucosa, which has a similar oral mucosa to that of man.Biopsies of porcine attached gingiva, buccal (B) and floor of mouth mucosa (FM) were incubated with either 2% or 6% nicotine in phosphate buffered saline (PBS) placed on the epithelial surface at 37°C for 1 or 2 hours. Controls were incubated with PBS at the same pH (7.5%) and osmolarity (450 milliosmoles) as the nicotine solution. The biopsies were prefixed in 2% paraformaldehyde, 2.5% glutaraldehyde, washed with cacodylate buffer, post fixed with 1% solution of osmium tetroxide in cacodylate buffer, dehydrated in graded alcohols, infiltrated, embedded and polymerized in Spurrs epoxy resin. Thin sections were prepared from all specimens and examined in the transmission electron microscope (TEM).
The Effect of Electron Microscopy on Pathological Diagnosis of Neoplasm
Authors: Zhou Xiaojun , Zhang Taihe 
Published: June 2020

Although electron microscopy (EM) has contributed enormously to an understanding of the structural intricacies of tumor cells, the usefulness of EM in pathological diagnoses of neoplasms has not been readily appreciated by general pathologists. In the present study, 223 tumors submitted for EM diagnosis were analyzed in an attempt to gain further information concerning the contribution of EM to tumor diagnosis.223 neoplasms were submitted to EM for their final diagnoses when histopathological diagnoses were obscure, which represented about of the total number of surgical tumor specimens. Most specimens were taken at the time of frozen section diagnosis and a small number of tissues were originally fixed informaldehyde. All of tissues were fixed with buffered glutaradehyde, postfixed with osmium tetroxide and embedded in Epon 812. Ultrasections were made after semith in sections were examined to verify that representative tumor tissues were present. Thin sections were stained with uranium acetate and lead citrate, and examined under JEM-1200 EX electron microscope. In selected cases, mainly with neuroendocrine tumors, nickel grid-mounted sections were subjected to post embedding immunoelectron microscopy (IEM) using protein A-gold for more detailed functional classification. Protein A-gold probes were prepared as Wang and co-workers described.
Studies on Ultrastructure and Cytochemistry of Right Ventricular Endomyocardial Biopsy
Authors: Mingyu Xia , Wengshu Ma , Xiangh Wu , Dong Chen 
Published: June 2020

This paper describes morphological and cytochemistry changes of endomyocardial biopsy in 94 patients. The samples of myoicardium were taken from 32 patients with dilated cardiomyopathy, and sdudied with light and electron microscop. The cytochemical studies in some of these patients were performed at histological and ultrastructure level. This paper also reported the result of myocardial biopsy in 33 patients with serious dysrythmia.The result of this controlled study indicates that morphological assessment in both cardiomyopathy and congenital or rheumatic heart diseases showed no special changes. In patients of dilated cardiomyopathy, the decreased activity of myosin ATPase was secondary to cardial failure. The change of succinate dehydrogenase (SDHase) was not significant with light microscopy. But ultrastructural localization of SDHase activity is valuable. Its activity was found to be localized in endomembrane and ridge of the mitochondria, the activity of this enzyme was decrease, normal, or increase. SDHase activity was more intense in cardial myocytes well-functioning, or ultrastructurally well preserved hearts.
Application of Transmission Electron Microscope and Scanning Electron Microscope in experimental tumor studies
Authors: Fengming Gao 
Published: June 2020

Transmission electron microscope(TEM) and scanning electron microscope(SEM) were widely used in experimental tumor studies. They are useful for evaluation of cellular transformation in vitro, classification of histological types of tumors and treating effect of tumors. We have obtained some results as follows:1. Studies on the malignant transformation of mammalian cells in vitro. Syrian golden hamster embryo cells(SGHEC) were transformed in vitro by ThO2 and/or ore dust. In a few days after dust added into medium, some dust crystals were phagocytized. Two weeks later, malignant transformation took place. These cells were of different size, nuclear pleomorphism, numerous ribosomes, increasing of microvilli on cell surface with various length and thickness, and blebs and ruffles(Figs. 1,2). Myelomonocytic leukemic transformation of mouse embryo cells(MEC) was induced in vitro by 3H-TdR. Transformed cells were become round from fusiform. The number of mitochondria and endoplasmic reticulum was reduced, ribosomes and nucleoli increased, shape of nuclei irregular, microvilli increased, and blebs and ruffles appeared(Fig. 3).
Evidences for the phagocytic activity of cultured rat mesangial cells
Authors: Kouda Katsuyoshi , Imada Masato , Igarashi Yoshio , Yamashita Akira 
Published: June 2020

It is known that glomerular mesangial cells have two major functions; the control of glomerular blood flow by contraction and the removal of macromolecules from the mesangial region by the endocytosis. As regards the latter function, the evidence of phagocytic activity for particulate materials is controversial. In this study, we attempted to make it clear whether mesangial cells isolated from glomeruli exhibit phagocytic activity in vitro.Male Sprague-Dawley rats, 6-8 wk old, were used. Glomeruli were isolated from rat renal cortex by the sieving technique according to Morita. The isolated glomeruli were cultured at 37°C in an atmosphere of 95% air, 5% CO2 in a medium containing 5ml of RPMI-1640 with 20% decomplemented fetal calf serum, and subcultured. Mesangial cells purified at the 6-20th succesive cultivations were identified by their morphology and antigenic phenotypes which were analyzed by immunohistochemical method using anti Thy-1, anti Ia, anti leukocyte common(LC) antigen, anti iC3bR, and Mar(anti rat macrophage antigen) 1-4 monoclonal antibodies. Fc receptor was detected with rosette forming method using sheep blood cells(SRBC).
Electron Microscopic study of the parathyroid gland of the melatonin-treated hamster
Authors: Shoumura Shizuko , Emura Shoichi , Yamahira Tomo , Kawada Tomoo , Oda Hiroshi , Arakawa Michio , Isono Hideo 
Published: June 2020

Some studies have dealt with the relationship between the pineal gland and the parathyroid gland (PTG) Morphological changes suggest that the pineal gland may inhibit or stimulate the PTG. There are a few light microscopic studies on the effects of pineal extract on the PTG. However, there is no study on the effects of melatonin on the ultrastructure of the PTG. We investigated ultrastructural changes in the PTG of golden hamsters after administration of melatonin.Materials and methods. Three-month-old female golden hamsters with an average body weight of 130 g were divided into 5 groups of 5 animals each. One group was given 0.2.ml of distilled water as controls. The remaining groups were given 0.2 ml of melatonin solution at a dose of 0.8 mg/100 g body weight. The PTG of each group was removed under pentobarbital anesthesia at 1, 5, 24 and 48 hours after injection. The PTG was immersed in a mixture of 2.5% glutaraldehyde and 2% OsO4, dehydrated through acetone and embedded in Epon 812.
Internalization of gold-labeled IA antigens induces formation of Birbeck granule-like structures in murine Langerhans cells
Authors: Bucana Corazon D. , Munn Gwynneth , Ja Song Min , Dunner Kenneth , Kripke Margaret L. 
Published: June 2020

Langerhans cells (LC) are migratory bone marrow-derived dendritic cells that reside in the basal portion of the epidermis. LC are antigen presenting cells; they express MHC Class II antigens, macrophage maturation marker, F4/80, and exhibit a distinctive cytoplasmic pentalaminar organelle called Birbeck granules (BG). Murine LC have fewer BG than human LC. The origin of BG is not clear although several reports suggest that BG are formed by invagination of the cytomembrane to form a membrane sandwich.In this study, dendritic cells (DC) from the draining lymph nodes (DLN) of mice previously sensitized with fluorescein isothiocyanate were examined by fluorescence and electron microscopy. Expression of la antigen by dendritic cells was determined by immunogold labeling using either Janssen Auroprobe GAM40 (Amersham Corporation, IL) as the secondary antibody or Protein- A-gold (20nm) (Polysciences, Inc., PA) label. Cells were labeled at 4°C and then warmed to ambient temperature. Samples were taken a t various time intervals and processed for TEM. Serial sections of dendritic cells were examined for presence of BG.
Three-dimensional analysis of erythrophagosome in lymph node macrophage by methods of cellular matrix maceration and freeze-replica
Authors: Sasaki Katsunori , Ichikawa Misao 
Published: June 2020

Although many ultrastructural works about erythrophagocytosis in various organs have been accumulated, few has been reported in the lymph node. This study discloses the degradative pathways of the erythrophagosomes in the lymph node macrophages ultrastructurally and three-dimensionally by transmission electron microscopy and the methods of cellual matrix maceration and freezereplica.The portal veins of adult male rats were clamped in the middle with a forceps for 1.5 min after deep anesthesia and laparotomy. At 0.5, 1, 3, 4, 6 hr after the treatment the mesenteric lymph nodes were prepared for cellular matrix maceration, freeze-replica and conventional electron microscopy as follows. CELLULAR MATRIX MACERATION: the lymph nodes fixed with 2% glutaraldehyde for 2 min were postfixed with 1% OsO4 at 4°C for 2 hr, transferred into 70% ethanol, frozen with nitrogen liquid, fractured into two pieces by the blade and macerated in 0.1% OsO4 solution at room temperature for 4 hr.
Fine structural morphology of immunocytes of some molluscs and insects
Authors: Pal S.G. , Baur G. , Ghosh B. , Palit S. , Modak S. , Chowdhury N. 
Published: June 2020

In recent years some of the blood cells of several molluscs and insects are characterised as immunocytes. Similar cells from a few invertebrates from India have been looked into under conventional TEM to register the ultrastructural features. This type of study is first of its kind in the subcontinent. Immunocytes from bivalve molluscs Meretrix meretrix, Laroellidens marqinalis and two insect species, apterygote Ctenolepism a longicaudata and pterygote Gesonula punctifrons provide a new set of fine structural information which forms a basis of comparison with those studied earlier.Immunocytes have been collected from the fresh live species of bivalve molluscs and insects obtained locally at Calcutta. These were fixed in icecold 2% glutaraldehyde in 0.1M phosphate buffer (pH 7.2-7.4) for 1-2 hours at 4-5°C. Subseguently pellets were post-osmicated in 1% OsO4 at room temperature for 1-2 hours. Following dehydration these were embedded in Araldite mixture in plastic capsules and polymerization was effected for 2 days at 60°C. Ultrathin sections were cut in a ultrotome and sections were double stained with Uranyl acetate and lead citrate. These were viewed in a TEM.
Permeability of the pineal gland of the viscacha (Lagostomus maximus maximus) to the lanthanum hydroxide
Authors: Piezzi Ramón , Dominguez Susana , Scardapane Luis , Guzmán Jorge 
Published: June 2020

The introduction of lanthanum to study the transport across the capillary endothelium and also as tracer in the skeletal muscle was followed by the use of this salt as an intercellular marker. One of the potential routes for the secretory products of the pineal is the circulatory system. The other postulated route is the ventricular cerebrospinal fluid (CSF). In this sense, a junctional interrelationship between the pineal gland and the CSF has been postulated in different mammals. The present work contains observations on the junctions between the parenchymal cells and the morphological characteristics of the blood vessels of the viscacha pineal using a lanthanum as extracellular marker.A total of five adult male viscachas (4 to 5 kgs of body weight) are used. The animals are collected near San Luis, Argentina (33°20’ South latitude; 760 m altitude) during summer and winter seasons. On the day of sacrifice the rodents are anesthetized, the brain exposed and a solution of fixative-lanthanum is injected slowly into the third ventricle. The pineal gland is then removed and immersed for 2 h more in the same fixative without lanthanum hydroxide. Ultrathin sections are examined in TEM.
Evaluation of hippocampus in rhesus monkeys after chronic (1-year) inhalation exposure to marijuana: I. Electron microscopy
Authors: Andrews A.M. , Wilson S.W. , Scallet A.C. , Ali S.F. , Bailey J. , Paule M.G. , Slikker W. 
Published: June 2020

Exposure of rhesus monkeys (Macaca mulatta) to marijuana via inhalation or to intravenous delta-9-tetrahydrocannabinol (THC), reportedly caused ultrastructural evidence of increased synaptic width. Chronic marijuana smoke in a single rhesus monkey examined after a six month withdrawal time caused ultrastructure changes in the septal, hippocampal and amygdala regions; the synaptic cleft was widened, electron opaque material was found in the cleft and in the pre- and postsynaptic regions, with some clumping of the synaptic vesicles. The objective of our study was to assess neuropathological alterations produced by chronic inhalation of marijuana smoke.Nineteen male rhesus monkeys, 3-5 years of age and weighing 3-8 kg, were divided into four treatment groups: a) sham control, b) placebo smoke (7 days/ week) c) low dose marijuana (2 times/week with 5 days/week sham) and d) high dose marijuana (7 times/week). A smoke exposure consisted of smoke from one cigarette (2.6% THC) burned down to 10 mm butt length. Smoke was administered via smoke generator (ADL II, Arthur D. Little, Inc. Cambridge, MA) and nose-mouth only masks (local production) equipped with one-way valves.
High-voltage EM description of the types and distribution of sensory endings in the inner conical body of the rat vibrissal follicle-sinus complex
Authors: Mosconi Tony M. , Song Min J. , Rice Frank L. 
Published: June 2020

Whiskers or vibrissal follicle-sinus complexes (F-SCs) on the snouts of many mammalian species are structures that have complex, dense sensory innervation. The innervation of F-SCs is remarkably similar in all species with the exception of one site - the inner conical body (ICB). The ICB is an elongated cylindrical structure that encircles the hair shaft near the neck of the follicle. This site has received only cursory attention in ultrastructural studies of the F-SCAdult rats were perfused after the method of Renehan and Munger2. F-SCs were quartered longitudinally and embedded separately in Epon-Araldite. Serial 0.25 μm sections were cut in either the longitudinal or perpendicular plane through the ICB and examined with an AEI EM7 1.2 MV HVEM (Albany, NY) at 1000 KV. Sensory endings were reconstructed from serial micrographs through at least 20 μm in the longitudinal plane and through 10 μm in the perpendicular plane.From two to six small superficial vibrissal nerves converge upon the neck of the F-SC and descend into the ICB. The nerves branch into smaller bundles of myelinated and unmyelinated axons along the dorsal side of the hair shaft.
Bile canalicular microfilament (BCMF) in experimental cholestasis: Freeze-etching study
Authors: Yasuda Hiromoto , Seki Keiko , Tamaki Yoshimi , Yamanaka Masami , Sano Naoyo 
Published: June 2020

In this studies, authors tried to clarify the fine structural features of bile canalicular microfilaments(BCMF) closely related to the bile canalicular structures in the experimentally induced rat liver cells.Male Wistar rats, administrated Phailoidin 50μg/100g. BW., intraperitoneally for 5 days, and sodium Taurolithocolate(TLC), intravenously, for 40 min., 80 min. and 120 min. After minced liver tissues, small pieces were rapidly frozen on copper block cooled with liquid N2, and were freeze-etched in Balzers 400 or JFD 9000 machines. Specimens of replicae as well as thin sections prepared usual thin section method were observed HU.12A electron microscope at 75 to 100KV.In freeze-etched replica of normal liver, there were moderate number of microfilament(Mf) with trabecular mesh-work. FIG.1.indicates thin and short filaments closely attached to the trabecules and subsequently related to the organellaes. Bundles of intermediate filaments(If) were also encountered closely linked to the Mf. Phailoidin treated liver, there were markedly increase in number of Mf and occasional small vesicular structures. Lumen of canaliculi were dilated with decrease in number or shortening of microvilli(Mv)(FIG.2).