Modification of Pineal Ultrastructure by Exogenous Hormones

1967 ◽  
Vol 25 ◽  
pp. 170-171
Author(s):  
R. A. Turner ◽  
A. E. Rodin ◽  
D. K. Roberts
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Estradiol Benzoate ◽  
Female Rats ◽  
List Type ◽  
Type Number ◽  
Pregnant Rats ◽  
Gonadal Atrophy ◽  
Pineal Ultrastructure

There have been many reports which establish a relationship between the pineal and sexual structures, including gonadal hypertrophy after pinealectomy, and gonadal atrophy after injection of pineal homogenates or of melatonin. In order to further delineate this relationship the pineals from 5 groups of female rats were studied by electron microscopy:ControlsPregnant ratsAfter 4 weekly injections of 0.1 mg. estradiol benzoate.After 8 daily injections of 150 mcgm. melatonin (pineal hormone).After 8 daily injections of 3 mg. serotonin (melatonin precursor).No ultrastructural differences were evident between the control, and the pregnancy and melatonin groups. However, the estradiol injected animals exhibited a marked increase in the amount and size of rough endoplasmic reticulum within the pineal cells.

scholarly journals Preparation of Protein a Gold

1997 ◽  
Vol 5 (5) ◽  
pp. 12-13
Author(s):  
Paul Webster
Keyword(s):  
Electron Microscopy ◽  
Biological Activity ◽  
Colloidal Gold ◽  
Protein A ◽  
List Type ◽  
Type Number ◽  
Stained Glass ◽  
Small Particles ◽  
Silver Enhancement ◽  
Gold Particles

Colloidal gold has been used for centuries in the preparation of stained glass for windows and fine glassware. In recent years, colloidal gold particles have become a useful tool in microscopy for staining tissues and sections. Colloidal gold particles are especially useful for biological electron microscopy, Some of the reasons why are listed below.*Homogeneous preparations of particles varying in size from 3μm to 20μm can be easily prepared.*Colloidal gold suspensions are inexpensive to prepare. Most proteins can be easily coupled to colloidal gold particles.*Most proteins can be easily coupled to colloidal gold particles.*Proteins coupled to gold particles do not appear to lose their biological activity.*The colloidal gold particles can be easily seen in the electron microscope.*Colloidal gold does not naturally occur in biological material. Therefore, if you see it, it is because you put it there.*Colloidal gold probes can be used for light microscopy, The larger gold particles can be directly observed by the light microscope. Small particles are detected by silver enhancement or epipolarized illumination.*The same probes can be used for both LM and TEM imrnunocytochemistry.

scholarly journals Embedding Cultured Cells Grown in Well Plates

2006 ◽  
Vol 14 (3) ◽  
pp. 50-52
Author(s):  
Leona Cohen-Gould
Keyword(s):  
Electron Microscopy ◽  
Cross Sections ◽  
Cultured Cells ◽  
List Type ◽  
Type Number ◽  
Razor Blade ◽  
Cell Monolayers ◽  
Block Face ◽  
Resin Mixture

For years, I have used a hybrid Epon-analog resin to embed in culture dishes. I use a standard Epon formula but utilize the following components: LX-112 and DMP-30 from Ladd Research Industries DDSA and NMA from Electron Microscopy Sciences I know it seems weird, but years ago I tried all sorts things, from the “straight” formulations from each vendor to a bunch of mixtures. This one has never reacted with the plastic of the dishes. Here is how I do the actual embedding of the cell monolayers in the dishes:1)After the last 100% ethanol, remove the alcohol and cover the bottom of the well with a layer of resin mixture that is about 2 mm deep.2)Insert embedding tubes that are made by cutting the pyramidal bottoms off of BEEM capsules (just slice them with a fresh razor blade and be sure to insert them so that the manufactured end rather than the cut one is sitting against the dish).3)After inserting labels into the tubes, put them into the oven at 60° overnight.4)In the morning, fill just the embedding tubes and return everything to the oven again to finish polymerizing.5)When the resin is cured, grab the tubes with a pair of needlenosed pliers and snap them out. Sometimes a bit of the bottom of the dish comes away with the block, but often a very smooth block face results. If some of the dish comes up, it is easy to see under a dissecting microscope, and the dish portion comes away easily when trimming the block face.I often cut away part of the block face with a jeweler's saw, either to keep it in reserve or to re-embed it in order to get cross sections, and then trim the rest into a narrow rectangle.

Development of the lateral palatal brush in larvae of Aedes aegypti (L.) (Diptera: Culicidae)

1990 ◽  
Vol 68 (7) ◽  
pp. 1454-1467 ◽  
Author(s):  
K. M. Fry ◽  
S. B. McIver
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Golgi Apparatus ◽  
Aedes Aegypti ◽  
Rough Endoplasmic Reticulum ◽  
Light And Electron Microscopy ◽  
Fourth Instar ◽  
Muscle Fibres ◽  
Final Length

Light and electron microscopy were used to observe development of the lateral palatal brush in Aedes aegypti (L.) larvae. Development was sampled at 4-h intervals from second- to third-instar ecdyses. Immediately after second-instar ecdysis, the epidermis apolyses from newly deposited cuticle in the lateral palatal pennicular area to form an extensive extracellular cavity into which the fourth-instar lateral palatal brush filaments grow as cytoplasmic extensions. On reaching their final length, the filaments deposit cuticulin, inner epicuticle, and procuticle sequentially on their outer surfaces. The lateral palatal crossbars, on which the lateral palatal brush filaments insert, form after filament development is complete. At the beginning of development, the organelles involved in plasma membrane and cuticle production are located at the base and middle of the cells. As the filament rudiments grow, most rough endoplasmic reticulum, mitochondria, and Golgi apparatus move to the apex of the epidermal cells and into the filament rudiments. After formation of the lateral palatal brush filaments and lateral palatal crossbars, extensive organelle breakdown occurs. Lateral palatal brush formation is unusual in that no digestion and resorption of old endocuticle occurs prior to deposition of new cuticle. No mucopolysaccharide secretion by the lateral palatal brush epidermis was observed, nor were muscle fibres observed to attach to the lateral palatal crossbars, as has been suggested by other workers.

scholarly journals A New Universal Acrylic Embedding Resin for Both Light and Electron Microcopy

1994 ◽  
Vol 2 (4) ◽  
pp. 21-22
Author(s):  
Donald P. Cox
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Light Scattering ◽  
Tissue Structure ◽  
Original Structure ◽  
Plant Tissues ◽  
List Type ◽  
Type Number ◽  
Tissue Specimen ◽  
Low Viscosity

Successful immunolabeling in electron microscopy of animal and plant tissues requires a combination of excellent antigen preservation while maintaining the original structure of the tissue. One important element is tissue embedding which accomplishes two goals for the immunohistochemist, the preservation of tissue specimen structure and maintenance of biological antigenicity. Tissue embedding in plastic resins is a common method in which several important elements must be considered.1.Fine tissue structure must not be damaged by the polymerization.2.The plastic must be stable to the electron beam.3.Light scattering properties of the plastic should be minimal.4.The plastic should cut easily.5.The plastic must be of sufficiently low viscosity to infiltrate the tissue.

Effects of dehydration and arginine vasopressin infusions on the production of milk and the morphology of the goat udder

1990 ◽  
Vol 57 (4) ◽  
pp. 479-487 ◽  
Author(s):  
Kristina Dahlborn ◽  
Jamal Hossaini Hilali ◽  
Heriberto Rodriguez-Martinez
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Mammary Gland ◽  
Milk Production ◽  
Rough Endoplasmic Reticulum ◽  
Arginine Vasopressin ◽  
Alveolar Cells ◽  
Lactating Goats

SummaryLactating goats were subjected to dehydration and to infusions of arginine vasopressin (AVP). Dehydration decreased milk production significantly but no changes were observed on the day of AVP infusion. The levels of AVP in plasma reached the same magnitude during both experimental procedures. AVP-immunoreactivity was immunocytochemically detected by light (peroxidase-antiperoxidase technique) and electron microscopy (immuno-Au technique on to glutaraldehyde-fixed, resin-embedded sections) in the mammary gland but not in the control experiments. In addition the cisternae of the rough endoplasmic reticulum in the secretory alveolar cells underwent significant swelling in response to the experimental procedures.

P3502Transmission electron microscopy reveals ultrastructural differences between reticulated and non-reticulated human platelets

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
L Hille ◽  
T Nuehrenberg ◽  
M Lenz ◽  
A Vlachos ◽  
D Trenk
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Rough Endoplasmic Reticulum ◽  
Human Platelets ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Dense Granules ◽  
Increased Risk

Abstract Reticulated platelets (RP) are the youngest circulating platelets in blood. Compared to older platelets, RP represent a highly active prothrombotic platelet population associated with an increased risk for cardiovascular events, mortality and impaired response to antiplatelet drugs compared to older platelets (non-RP). The underlying mechanisms for these characteristics of RP are so far poorly understood. This study aimed to characterize ultrastructural properties of RP and non-RP by transmission electron microscopy (TEM) of FACS-sorted human platelets using a novel staining method for RP. Washed platelets from three healthy donors were stained by SYTO™13, a nucleic acid binding fluorescent dye, which enables determination of RP and non-RP based on their RNA-content. 8×106 platelets were fixed, sorted and sandwiched between two layers of agarose gel. Samples were further processed for visualization by TEM. In total, 1047 platelets, i.e., electron micrographs of individual cross-sections, were analysed by an investigator blinded concerning experimental condition. Sizes, numbers of α-granules, dense granules, mitochondria and open canalicular system openings were assessed in RP and non-RP, respectively. Furthermore, platelets were screened for pseudopodia formation as an indicator for activation. Cross-sectional area was significantly different between RP and non-RP (2.44 [1.80–3.22] vs. 1.34 [1.04–1.89] μm2; p<0.0001; median with IQR). α-granule and mitochondria amounts were higher in RP which persisted even after adjustment for platelet size (α-granules: 4.64 [3.46–5.86]/μm2 vs. 4.15 [2.87–5.26]/μm2; p<0.0001; mitochondria: 0.33±0.02 /μm2 vs. 0.12±0.01/μm2; mean ± SEM). In contrast, the amount of open canalicular system openings per square μm was higher in the non-RP group (5.82 [4.34–7.68] /μm2 vs. 5.52 [4.01–7.11] /μm2; p=0.009). Dense granule content per square μm was similar in both RP and non-RP. Pseudopodia were present in 38% (RP) respective 37% (non-RP) of platelets. Notably, golgi apparatus and rough endoplasmic reticulum which are rarely seen in platelets were detected in several RP. Analysis of TEM pictures revealed an almost 2-fold higher cross-sectional area in RP compared to non-RP. Even after adjustment for differences in size, α-granule content remained significantly higher in RP indicating a higher storage pool for prothrombotic constituents like p-selectin or von Willebrand factor. Although the relative amount of dense granules per area did not differ between the two groups, a higher absolute number of dense granules per platelet in the RP group is indicative for higher amounts of stored small molecules such as ADP, calcium or serotonin. Despite the anucleate nature of platelets, the presence of golgi apparatus and rough endoplasmic reticulum suggests the capability of protein biosynthesis in RP. These comprehensive findings provide new important insight into the ultrastructural properties of human RP. Acknowledgement/Funding PharmCompNet Baden-Württemberg: Kompetenznetzwerk Pharmakologie Baden-Württemberg

scholarly journals Ultrastructure of rhesus monkey renomedullary interstitial cells

1979 ◽  
Vol 13 (2) ◽  
pp. 75-80 ◽  
Author(s):  
David J. Lewis ◽  
David E. Prentice
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Rhesus Monkey ◽  
Rough Endoplasmic Reticulum ◽  
Lipid Droplets ◽  
Stellate Cells ◽  
Interstitial Cells ◽  
Prominent Feature

Summary The fine structure of rhesus monkey renomedullary interstitial cells was studied by electron microscopy. These stellate cells contained variable numbers of lipid droplets, moderate numbers of mitochondria, moderate amounts of rough endoplasmic reticulum, and prominent Golgi zones. In rare instances, apparent release of lipid droplets into the interstitium was observed. The most prominent feature of the interstitial cells was large nuclear pseudoinclusions which were observed in a high proportion of the animals examined.

The Morphology of Normal and Abberrant Murine Type Leukemia Virus and Its Relationship to Ribosomes

1972 ◽  
Vol 30 ◽  
pp. 274-275
Author(s):  
T. N. Tahmisian ◽  
E. J. Ainsworth
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Intraperitoneal Injection ◽  
Leukemia Virus ◽  
X Rays ◽  
Type Virus ◽  
Unit Membrane ◽  
Viral Membrane ◽  
Viral Development

Studies are in progress to characterize a transmissible leukemia and the causal agent which is presumably viral. The neoplasm, originally isolated from an aged irradiated B6CF1, mouse, has been transmitted in irradiated (200 R; 250 kVp X rays) weanling mice by intraperitoneal injection of millipore filtered (0.45μ) supernatant from spleen cell suspensions. At 22 days after filtrate injection in syngeneic mice, spleen, lymph nodes, and thymus were removed and prepared for electron microscopy to determine the presence of virus and morphology of viral development.The ultrastructure of cells from the above organs showed viral infection by a murine type leukemia virus with many “C” type buds 90 to 110nm formed in the cisternae of the rough endoplasmic reticulum (Fig. 1). The limiting membrane of the “C” type virus, apparently isolating it from the cytoplasm, is the unit membrane from the rough endoplasmic reticulum. The viral membrane is not invariably intact.

A Study on the Occurrence of Gold in Unoxidized Carlin-Type Ores in China Using AEM, SEM-EDX and SXRF

1990 ◽  
Vol 48 (2) ◽  
pp. 414-415
Author(s):  
Liu Yongkang ◽  
Liu Shirong ◽  
Wan Guangquan ◽  
Zhou Lindi ◽  
Li Jilian ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gold Mineralization ◽  
Analytical Electron Microscopy ◽  
List Type ◽  
Type Number ◽  
X Ray ◽  
Combined Use ◽  
Analytical Electron ◽  
Scanning Electron ◽  
Gold Bearing

The knowledge about the occurrence of gold is essential both to the explanation for the genesis of gold mineralization in its deposits and to the evaluation and exploration or even smelt process of its ores. It has been well known that the gold occurrence in the Carlin-type ores still remains a difficult question to be answered because of the tiny scale of its locality and its very low content.This paper reports the results of our analysis on some gold bearing minerals in the Carlin-type ores discovered during recent years in China with combined use of analytical electron microscopy (AEM), scanning electron microscopy-energy dispersive X ray spectrometry (SEM-EDX) and synchrotron X ray flourescence analysis (SXRF) techniques as following:(1) Some gold occurred as submicron size grains in the ores (see Photo 1-4 and Figure 1-3) with grain size generally less than 0.2 micron.(2) It has been found by AEM and SEM-EDX observation and SXRF analysis that gold occurred as micrograins embedded in the boundaries of clay or quartz minerals rather than, as said, entered the lattice or adhered as a covering film to the surface of clay minerals (see Figure 4).

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