An ultrastructural study of sertoli cells in two geographically isolated populations of Aphanius dispar

1992 ◽  
Vol 50 (1) ◽  
pp. 548-549
Author(s):  
Taber A. Ba-Omar ◽  
Philip F. Prentis
Keyword(s):  
Ultrastructural Level ◽  
Uranyl Acetate ◽  
Freshwater Teleost ◽  
Isolated Populations ◽  
En Bloc ◽  
The North ◽  
Group A ◽  
Ultrathin Sections ◽  
Group B ◽  
Geographically Isolated

We have recently carried out a study of spermiogenic differentiation in two geographically isolated populations of Aphanius dispar (freshwater teleost), with a view to ascertaining variation at the ultrastructural level. The sampling areas were the Jebel Al Akhdar in the north (Group A) and the Dhofar region (Group B) in the south. Specimens from each group were collected, the testes removed, fixed in Karnovsky solution, post fixed in OsO, en bloc stained with uranyl acetate and then routinely processed to Agar 100 resin, semi and ultrathin sections were prepared for study.

Platinum Compounds as Stains for Electron Microscopy

1974 ◽  
Vol 32 ◽  
pp. 230-231
Author(s):  
S. K. Aggarwal ◽  
P. McAllister ◽  
R. W. Wagner ◽  
B. Rosenberg
Keyword(s):  
Electron Microscopy ◽  
Hela Cells ◽  
Uranyl Acetate ◽  
Sarcoma 180 ◽  
Platinum Compounds ◽  
Kb Cells ◽  
En Bloc ◽  
Human Lymphoma ◽  
Ultrathin Sections ◽  
Blue Coloration

Uranyl acetate has been used as an electron stain for en bloc staining as well as for staining ultrathin sections in conjunction with various lead stains (Fig. 1). Present studies reveal that various platinum compounds also show promise as electron stains. Certain platinum compounds have been shown to be effective anti-tumor agents. Of particular interest are the compounds with either uracil or thymine as one of the ligands (cis-Pt(II)-uracil; cis-Pt(II)-thymine). These compounds are amorphous, highly soluble in water and often exhibit an intense blue coloration. These compounds show enough electron density to be used as stains for electron microscopy. Most of the studies are based on various cell lines (human AV, cells, human lymphoma cells, KB cells, Sarcoma-180 ascites cells, chick fibroblasts and HeLa cells) while studies on tissue blocks are in progress.

Ultrastructural morphology of neurosecretory neurons in the barnacle Balanus amphitrite

1990 ◽  
Vol 48 (3) ◽  
pp. 434-435
Author(s):  
Grazia Tagliafierro ◽  
Cristiana Crosa ◽  
Marco Canepa ◽  
Tiziano Zanin
Keyword(s):  
Nervous System ◽  
Ultrastructural Level ◽  
Uranyl Acetate ◽  
Balanus Amphitrite ◽  
Neurosecretory Neurons ◽  
The Central Nervous System ◽  
Ultrathin Sections ◽  
Dense Core Granules ◽  
The Brain ◽  
Ocellar Nerve

Barnacles are very specialized Crustacea, with strongly reduced head and abdomen. Their nervous system is rather simple: the brain or supra-oesophageal ganglion (SG) is a small bilobed structure and the toracic ganglia are fused into a single ventral mass, the suboesophageal ganglion (VG). Neurosecretion was shown in barnacle nervous system by histochemical methods and numerous putative hormonal substances were extracted and tested. Recently six different types of dense-core granules were visualized in the median ocellar nerve of Balanus hameri and serotonin and FMRF-amide like substances were immunocytochemically detected in the nervous system of Balanus amphitrite. The aim of the present work is to localize and characterize at ultrastructural level, neurosecretory neuron cell bodies in the VG of Balanus amphitrite.Specimens of Balanus amphitrite were collected in the port of Genova. The central nervous system were Karnovsky fixed, osmium postfixed, ethanol dehydrated and Durcupan ACM embedded. Ultrathin sections were stained with uranyl acetate and lead citrate. Ultrastructural observations were made on a Philips M 202 and Zeiss 109 T electron microscopy.

scholarly journals Immunoelectron microscopic localization of alpha-actinin on Lowicryl-embedded thin-sectioned tissues.

1985 ◽  
Vol 33 (6) ◽  
pp. 515-522 ◽  
Author(s):  
L F Lemanski ◽  
D J Paulson ◽  
C S Hill ◽  
L A Davis ◽  
L C Riles ◽  
...  
Keyword(s):  
Ultrastructural Level ◽  
Uranyl Acetate ◽  
En Bloc ◽  
Smooth Muscle Tissue ◽  
Thin Sections ◽  
Microscopic Localization ◽  
Cell Architecture ◽  
Nonmuscle Cells ◽  
Staining Techniques ◽  
Lowicryl K4m

A procedure has been developed for the immunoelectron microscopic localization of intracellular antigens on thin-sectioned tissues. The tissues were fixed in a periodate-lysine-paraformaldehyde solution or a formaldehyde-glutaraldehyde combination and embedded in the acrylate-methacrylate mixture, Lowicryl K4M (Polaron), which was polymerized under ultraviolet irradiation at -35 degrees C. Thin sections were mounted on gold grids, immunostained using an indirect method with ferritin-labeled antibodies, and, optionally, counterstained with osmium tetroxide and/or lead citrate and uranyl acetate. The procedure provided good morphologic preservation of the cell architecture in adult and embryonic heart, and skeletal and smooth muscle tissue, as well as nonmuscle cells. At the same time it retained the antigenicities of several contractile proteins, including myosin, tropomyosin, actin, and alpha-actinin. The method has advantages over en bloc staining techniques in that the problem of antibody penetration into the cells is eliminated and careful controls can be performed on adjacent sections. This technique will be useful for localizing, at the ultrastructural level, contractile and other selected proteins in a variety of muscle and non-muscle cells. Details of the new protocol and a description of the results of using antibody against the contractile protein, alpha-actinin, are given.

Myocardial Alterations in Animals Following High Altitude Exposure

1968 ◽  
Vol 26 ◽  
pp. 114-115
Author(s):  
M. B. Bischoff ◽  
W. D. Dean ◽  
T. J. Bucci ◽  
L . A. Frics
Keyword(s):  
Pulmonary Artery ◽  
Right Ventricular ◽  
High Altitude ◽  
Sea Level ◽  
Osmium Tetroxide ◽  
Ultrastructural Level ◽  
Uranyl Acetate ◽  
Heart Weight ◽  
Morphological Evidence ◽  
Ultrathin Sections

There is a paucity of morphological evidence, particularly at the ultrastructural level, to correlate with tile physiological effects of chronic exposure to high altitude. In this study the myocardium of dogs and rabbits subjected to five months exposure at an altitude of 14,110 feet was compared to that of animals residing at sea level. The animals kept at 14,110 feet were shipped from sea level (160 feet) witnout acclimatization at intermediate altitudes.The physiological parameters including the hematologic changes, pulmonary artery pressures, pulmonary artery oxygen saturations, electrocardiograph changes, right ventricular weight to body weight and right ventricular weight to total heart weight ratios observed in these animals have been reported previously.The animals were necropsied at the end of the five months. The myocardium was quickly removed, cut into small pieces and immersed in 1% osmium tetroxide buffered with veronal acetate. Following fixation the tissues were dehydrated in ascending ethanol concentrations followed by propylene oxide and embedded in Epon 812. Ultrathin sections were doubly stained in uranyl acetate and lead citrate.

St. Louis encephalitis virus infection of a mosquito vector

1972 ◽  
Vol 30 ◽  
pp. 312-313
Author(s):  
Sylvia G. Whitfield ◽  
Frederick A. Murphy ◽  
W. Daniel Sudia
Keyword(s):  
Mammalian Cells ◽  
Culex Pipiens ◽  
Ultrastructural Level ◽  
The United States ◽  
Encephalitis Virus ◽  
Mosquito Vector ◽  
Plasma Viremia ◽  
Equine Encephalitis Virus ◽  
Group A ◽  
Group B

The course of arbovirus infections in the arthropods necessary for their transmission in nature has been studied extensively, but in only a few instances at the ultrastructural level. In the present study a model system was established for the infection of Culex mosquitoes with St. Louis encephalitis (SLE) virus (arbovirus group B ), the most important mosquito-bome disease in the United States. Results were compared with those of a previous study of Eastern equine encephalitis virus (arbovirus group A) in Aedes mosquitoes (this Proceedings, 1969, pp. 378-379) since differences in sites of maturation in mammalian cells have been found between the two groups.Culex pipiens mosquitoes were infected by feeding upon suckling mice infected with SLE virus (plasma viremia titer 105.4 SMLD50/ml). Mosquitoes were then held at 27°C; they were tested for capacity to transmit virus via bite, and specimens of salivary glands and other organs were collected at 18 intervals during 32 days.

Uranyl Acetate as a Fixative—from pH 2.0 to 8.0

1971 ◽  
Vol 29 ◽  
pp. 490-491
Author(s):  
V. R. Mumaw ◽  
B. L. Munger
Keyword(s):  
Electron Microscopy ◽  
Oxalic Acid ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
En Bloc ◽  
Tissue Sections ◽  
Normal Rat ◽  
Lead Hydroxide ◽  
Ultrathin Sections ◽  
Rat Tissue

Numerous applications utilizing uranyl acetate as an electron stain for electron microscopy have been described. Uranyl acetate has become a routine stain used in conjunction with lead hydroxide for staining ultrathin sections. En bloc staining with uranyl acetate following osmium tetroxide post-fixation produces undesirable effects on some cytoplasmic components, especially glycogen. Recent studies using uranyl acetate as a fixative and en bloc stain at pH 7.2 before osmification has shown uranyl acetate to have desirable fixation and staining qualities. Tissues treated with uranyl acetate at a pH of 2.0-8.0 were studied. Normal rat tissue was fixed in Karnovsky's paraformaldehyde-glutaraldehyde fixative. The tissue was post-fixed in 0.5% uranyl acetate in water at pH 2.0 and 0.5% uranyl acetate in 0.1M s-collidine with 0.01M oxalic acid at pH 4, pH 6.0, pH 7.2, and pH 8.0 for 1 hour at 4°C. Following several rinses of 0.1M s-collidine buffer, the tissues were treated with 1.33% osmium tetroxide 1 hour at 4°C followed by rapid dehydration in ethanol and embedded in Durcupan ACM. Tissue sections were stained with lead hydroxide.

scholarly journals Phase I Study of DNX-2401 (Delta-24-RGD) Oncolytic Adenovirus: Replication and Immunotherapeutic Effects in Recurrent Malignant Glioma

2018 ◽  
Vol 36 (14) ◽  
pp. 1419-1427 ◽  
Author(s):  
Frederick F. Lang ◽  
Charles Conrad ◽  
Candelaria Gomez-Manzano ◽  
W.K. Alfred Yung ◽  
Raymond Sawaya ◽  
...  
Keyword(s):  
Phase I ◽  
Malignant Glioma ◽  
Intratumoral Injection ◽  
Oncolytic Adenovirus ◽  
Post Treatment ◽  
Recurrent Malignant Glioma ◽  
En Bloc ◽  
Term Survival ◽  
Group A ◽  
Group B

Purpose DNX-2401 (Delta-24-RGD; tasadenoturev) is a tumor-selective, replication-competent oncolytic adenovirus. Preclinical studies demonstrated antiglioma efficacy, but the effects and mechanisms of action have not been evaluated in patients. Methods A phase I, dose-escalation, biologic-end-point clinical trial of DNX-2401 was conducted in 37 patients with recurrent malignant glioma. Patients received a single intratumoral injection of DNX-2401 into biopsy-confirmed recurrent tumor to evaluate safety and response across eight dose levels (group A). To investigate the mechanism of action, a second group of patients (group B) underwent intratumoral injection through a permanently implanted catheter, followed 14 days later by en bloc resection to acquire post-treatment specimens. Results In group A (n = 25), 20% of patients survived > 3 years from treatment, and three patients had a ≥ 95% reduction in the enhancing tumor (12%), with all three of these dramatic responses resulting in > 3 years of progression-free survival from the time of treatment. Analyses of post-treatment surgical specimens (group B, n = 12) showed that DNX-2401 replicates and spreads within the tumor, documenting direct virus-induced oncolysis in patients. In addition to radiographic signs of inflammation, histopathologic examination of immune markers in post-treatment specimens showed tumor infiltration by CD8+ and T-bet+ cells, and transmembrane immunoglobulin mucin-3 downregulation after treatment. Analyses of patient-derived cell lines for damage-associated molecular patterns revealed induction of immunogenic cell death in tumor cells after DNX-2401 administration. Conclusion Treatment with DNX-2401 resulted in dramatic responses with long-term survival in recurrent high-grade gliomas that are probably due to direct oncolytic effects of the virus followed by elicitation of an immune-mediated antiglioma response.

scholarly journals Comparison of epiretinal membrane peel after dual staining versus en bloc peel using negative staining technique

2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Tehmina Jahangir ◽  
Qasim Latif Chaudhary ◽  
Haroon Tayyab
Keyword(s):  
Staining Technique ◽  
Negative Staining ◽  
Brilliant Blue ◽  
Brilliant Blue G ◽  
En Bloc ◽  
Epiretinal Membranes ◽  
Quasi Experimental ◽  
Group A ◽  
Single Block ◽  
Group B

Purpose:  To compare the completeness of ILM peel in cases of Idiopathic Epiretinal Membranes following double staining and double peeling  versus en bloc dissection of both using negative staining method. Study Design:  Quasi experimental study. Place and Duration of Study:  Jinnah Hospital Lahore, from October 2017 to March 2018. Material and Methods:  Forty eyes of forty patients with Idiopathic Epiretinal membranes (ERM) were selected by non-probability convenient method and divided into two groups. In group A, the ERM was initially stained with Trypan blue and then peeled. Subsequently the macula was re-stained with Brilliant blue G (BBG). In group B, ERM and ILM were successfully peeled together as a single membrane utilizing the single block technique, after a desired negative staining effect was obtained by injecting BBG. The thoroughness of the ILM peel was established using another injection of BBG although a few remains were often identified outside the central macular area, no other dyes were used. Results:  In group A, 8 of the 20 eyes (40%) had full undisturbed ILM present whereas in 10 eyes (50%) the ILM was there but damaged, only 2 eyes (10%) had near total ILM removed. In group B, the dual peeling was successful in 17 of the 20 cases (85%). There has been no recurrence of ERM until now. Conclusion:  Instead of peeling twice, the single en bloc negative staining technique with Brilliant blue G is a safer and more effective method for removal of ERM together with ILM.

Fine structure of human sperm entry into zona-free hamster oocyte

1978 ◽  
Vol 36 (2) ◽  
pp. 540-541
Author(s):  
C. Barros ◽  
J. González ◽  
E. Herrera ◽  
E. Bustos-Obregón
Keyword(s):  
Osmium Tetroxide ◽  
Human Sperm ◽  
Ultrastructural Level ◽  
Uranyl Acetate ◽  
Human Spermatozoa ◽  
Low Viscosity ◽  
Cacodylate Buffer ◽  
Ultrathin Sections ◽  
Hamster Oocyte

Zona-free mammalian oocytes have been observed to fuse, under in vitro conditions, With non-homologous spermatozoa. Taking advantage of this heterologous gamete fusion, we designed a bioassay to test -by means of zona-free hamster oocytes- the fertile ability of human spermatozoa, from semen samples of patients attending an Infertility Clinic. To further validate our bioassay, which Was reported elsewhere, we studied the behavior of gamete membranes during fusion at the ultrastructural level.Zona-free hamster oocytes were mixed in vitro with human spermatozoa. At different times after the start of incubation, oocytes were fixed in 1% glutaraldehyde in 0. 25M cacodylate buffer pH 7. A and post-fixed in 196 osmium tetroxide. After dehydration in acetone, they were embedded in a low viscosity epoxy resin. Ultrathin sections were stained with uranyl acetate and lead citrate and examined with a Phillips 300 electron microscope.

scholarly journals Short-term outcomes of endoscopic submucosal dissection for superficial cecal tumors: a comparison between extension and nonextension into the appendiceal orifice

2018 ◽  
Vol 11 ◽  
pp. 175628481877279 ◽  
Author(s):  
Kazuki Boda ◽  
Shiro Oka ◽  
Shinji Tanaka ◽  
Hidenori Tanaka ◽  
Kenta Matsumoto ◽  
...  
Keyword(s):  
Endoscopic Submucosal Dissection ◽  
En Bloc Resection ◽  
Clinicopathological Characteristics ◽  
Bloc Resection ◽  
University Hospital ◽  
En Bloc ◽  
Female Ratio ◽  
Submucosal Dissection ◽  
Group A ◽  
Group B

Background: Few studies have investigated the use of endoscopic submucosal dissection (ESD) for cecal tumors extending into the appendiceal orifice. Herein, we assessed the feasibility and safety of ESD for cecal tumors extending into the appendiceal orifice. Methods: We retrospectively examined the outcomes of ESD for 78 patients with 78 cecal tumors (male/female ratio, 40/38; mean [standard deviation, SD] age, 67 [9] years; mean [SD] tumor size, 32 [15] mm), who underwent ESD at the Hiroshima University Hospital between October 2008 and March 2016. The indication for ESD in cecal tumors extending into the appendiceal orifice was recognition of the distal edge of the lesion in the appendix. They were classified into two groups: patients with cecal tumors extending (Group A: 29 patients, 29 tumors) and not extending (Group B: 49 patients, 49 tumors) into the appendiceal orifice. We compared the outcomes of ESD between both groups. Results: No significant differences in clinicopathological characteristics were observed between both groups. The rate of severe submucosal fibrosis in Group A (48%) was significantly higher than that in Group B (24%) ( p < 0.05). The mean (SD) procedure speed in Group A (14 [10] mm2/min) was significantly slower than that in Group B (23 [16] mm2/min) ( p < 0.01). The en bloc resection rates in Groups A and B were 90% and 96%, respectively. There were no significant differences in adverse events reported between both groups. Conclusions: ESD for cecal tumors with extension into the appendiceal orifice is effective and safe.

Sign in / Sign up

Export Citation Format

Share Document