bluuebunny/crossref_metadata_2025_split huggingface dataset:
Postmortem changes of the gill lamellae of fish
Authors: Liu K. C. 
Published: June 2020

The fine structure of the gill lamellae of fish has been reported for several species. All of them consisted the same types of cells and showed the same characteristics. The structural change of the gill lamellae under natural condition, after death was not reported. This report is to present a study on that event.Gill filaments from culturedAnguilla japonica,Tilapia sp. andChanos chanos, of marketing size, both fresh and dead for different length of time were studied. The samples were fixed with 3% glutaraldehyde and 1% osmic acid, dehydrated with ethanol, and embedded with Epon and Araldite mixture. Thin section were stained with uranyl acetate and lead citrate. Observations were made with a JEOL 100 CX electron microscpe at 60 KV.The gill lamella of all three species studied showed similar fine stuctural characteristics . They consisted a central raw of pillar cells which formed the blood lumen. A layer of epithelium covered the outer surface . There was a prominent layer of basal limina between those two types of cells (Fig. 1). The epithelium showed degeneration first. It disintegrated and ditached from the basal lamina, and formed debris.
Microtubule motors and other maps
Authors: Vallee Richard B. 
Published: June 2020

Microtubules are involved in a number of forms of intracellular motility, including mitosis and bidirectional organelle transport. Purified microtubules from brain and other sources contain tubulin and a diversity of microtubule associated proteins (MAPs). Some of the high molecular weight MAPs - MAP 1A, 1B, 2A, and 2B - are long, fibrous molecules that serve as structural components of the cytamatrix. Three MAPs have recently been identified that show microtubule activated ATPase activity and produce force in association with microtubules. These proteins - kinesin, cytoplasmic dynein, and dynamin - are referred to as cytoplasmic motors. The latter two will be the subject of this talk.Cytoplasmic dynein was first identified as one of the high molecular weight brain MAPs, MAP 1C. It was determined to be structurally equivalent to ciliary and flagellar dynein, and to produce force toward the minus ends of microtubules, opposite to kinesin.
Immunoprobe localization in mammalian embryos
Authors: Calarco Patricia G. , Siebert Margaret C. 
Published: June 2020

Visualization of preimplantation mammalian embryos by electron microscopy is difficult due to the large size of the ircells, their relative lack of internal structure, and their highly hydrated cytoplasm. For example, the fertilized egg of the mouse is a single cell of approximately 75μ in diameter with little organized cytoskelet on and apaucity ofor ganelles such as endoplasmic reticulum (ER) and Golgi material. Thus, techniques that work well on tissues or cell lines are often not adaptable to embryos at either the LM or EM level.Over several years we have perfected techniques for visualization of mammalian embryos by LM and TEM, SEM and for the pre-embedding localization of antigens. Post-embedding antigenlocalization in thin sections of mouse oocytes and embryos has presented a more difficult challenge and has been explored in LR White, LR Gold, soft EPON (after etching of sections), and Lowicryl K4M. To date, antigen localization has only been achieved in Lowicryl-embedded material, although even with polymerization at-40°C, the small ER vesicles characteristic of embryos are unrecognizable.
Immunocytochemistry after fast freeze fixation-freeze substitution: Advantages and limits
Authors: Nicolas Marie-Thérèse 
Published: June 2020

An alternative to aqueous chemical fixation consists in immobilizing physically the specimen by freezing it as fast as possible without using any cryoprotectant. This Fast Freeze Fixation (FFF) followed by Freeze Substitution (FS) avoids osmotic artefacts due to the slow penetration of liquid chemical fixative. Associated with Immuno-Gold labeling (IGS), FFF-FS allows a more precise localization of antigens.Using the bioluminescent bacteria Vibrio harveyi, a comparison of IGS with an antibody directed against its luciferase (enzyme of the luminescent reaction) has been done after liquid chemical fixation versus FFFFS. This later technique, beside an expected improvement of the ultrastructure always shows a better preservation of antigenicity and a lower background. In the case of FFF-FS technique (Figure 3):–labeling in acrylic resin (LRWhite) is 2 to 4 fold more intense than in epoxy resin (Epon),–but the ultrastructure is always better in Epon.–but the ultrastructure is always better in Epon.–The addition of fixatives in the substitution medium, results in a decrease of labeling which is more important in the case of a mixture of fixatives than with osmium tetroxide alone; with one exception: the substitution with glutaraldehyde which produces a dramatic increase in the density of the labeling but also, at the same time, a swelling of the cells of about 30%.
Modifications of sperm proteins leading to acquisition of fertilizing ability
Authors: Shalgi R. , Jones R. , Phillips D.M. 
Published: June 2020

Mammalian spermatozoa acquire their fertilizing ability following release from the seminiferous tubules, as they transverse the epididymis, the female tract and the egg investments. We have examined changes occurring in the distribution of antigens of rat spermatozoa during epididymal maturation and after ligation of the caput epididymis by using immunocytochemistry at the light microscopy and at the electron microscopy (EM) levels.Spermatozoa were collected from the test is and different segments of the epididymis. To obtain aging of sperm in vivo, male rats were operated and one side of the epididymis was ligated at the caput and corpus junction. Spermatozoa were washed, and divided into 4 tubes, and treated as follows: 1. no treatment; 2. permeabilization by freeze thawing; 3. Trypsin; 4. NP-40;. Sperm samples were washed and the nincubated for 30 min with monoclonal antibodies. Monoclonal antibodies were raised in mice against antigens on cauda sperm of rats.
Ultrastructural observations of the ciliated cyst in the human uterine tube epithelium
Authors: Hagiwara Haruo , Shibasaki Susumu , Ohwada Nobuo 
Published: June 2020

The ciliated cysts have been identified as a common manner of development of ciliated cells through light microscopic studies, however recent ultrastructural studies have Reported that they should be regarded as an expression of atypical ciliogenesis. In the present study we attempt to elucidate the detailed structure of the ciliated cysts and their significance in ciliogenesis in the human uterine tube epithelium.Human uterine tubes were obtained from 20 women who underwent total hysterectomies due to gynecological diseases. The ampullar segments were cut into small pieces, and fixed in 2.5% glutaraldehyde-2% paraformaldehyde (1/2 Kamovsky) in a 0.1M phosphate buffer solution (pH 7.4). These specimens were postfixed in a 1% Osmium tetroxide solution (Millonig), dehydrated with a graded series of ethanol and embedded in Epon 812. Ultrathin sections were stained with uranyl acetate and lead citrate, and examined in a transmission electron microscope.The ciliated cysts were detected as a round or oval intracytoplasmic cavity provided with many ciliary apparatuses and microvilli (Fig. 1).
Reflection Confocal Laser Microscopy in Neurobiology: Peroxidase and Golgi Preparations
Authors: Turner James N. , Szarowski Donald H. , Deitch Jeffrey S. , Smith Karen L. , Swann John W. 
Published: June 2020

One of the first applications of confocal microscopy was reflection imaging of unstained neurons. However, most applications employ either Golgi (silver impregnation) or peroxidase staining. Golgi preparations have been imaged by tandem scanning, but both need optimization for confocal laser scanned microscopy (CLSM) due to low signal levels and internal reflections. The imaging wavelength is critical. Specimen absorption of the argon ion laser lines is an order of magnitude larger than the HeNe red line. We compare the imaging of Golgi and peroxidase stained neurons using both lasers.Rat hippocampal neurons were filled with biocytin, fixed in 4% paraformaldehyde, incubated in avidin-HRP with Triton and reacted with DAB with or without Ni. Specimens were imaged in permount using a Bio-Rad MRC 500 and Olympus BH-2.
Ultrastructural Characteristics of Glioblastoma Multiforme
Authors: Sundaram A. , Bharati Arumugam Sarasa , Arumugam S. , Rajalakshmi Y. 
Published: June 2020

The ultrastructural studies of Glioblastoma multiforme was carried out from tissue obtained from human intracranial neoplasms obtained in Madras Institute of Neurology.Light microscopy showed a highly cellular neoplasm with areas of sinusoidal necrosis palisaded by spongioblasts. The malignant cells exhibited hyperchromatism, pleomorphism, bizarre nuclei and there were marked endothelial proliferations. Mono nuclear cell aggregates are also seen.Ultrastructurally Glioblastoma multiforme exhibited great variation in size and shape of cells. In the main, the cells were off moderate size with ovoid nuclei and fine chromatin distributed evenly throughout the nucleus. Nucleoli were prominent and here also the two distinct nuclear membranes could be easily be made out. Fine pores were seen in the nuclear membranece.The cytoplasm was relatively lucent and showed various organelles such as mitochondria, Golgi apparatus and elements of the rought endoplasmic reticulum in moderate numbers. The endoplasmic reticulum was dilated in many regions and numerous electron dense bodies could also be seen.
Early Cellular Events in the Development of Atherosclerotic Lesions in a Model of Accelerated Atherosclerosis in the Rabbit
Authors: Beesley Julian E. , Hassall David , Jessup Eileen A. , Honey Andrew , Dopping-Hepenstal Trish J.C. , Martin John F. , Moncada Salvador 
Published: June 2020

We have generated several of the characteristic features of human atherosclerotic lesions in the rabbit with in 14 days by the placement of a soft, silastic collar around the carotid artery. Preliminary microscopical studies show that the lesion in the region of the collar consists of proliferating smooth muscle cells, foam cells in animals maintained on a high cholesterol diet and that the endothelial cells appear intact. The histology of the contralateral arteries was unaffected by the placement of the collar. This report describes our observations of the early cellular changes in the collar region with particular regard to the presence of monocytes, macrophages and polymorphonuclear leukocytes.One group of New Zealand White rabbits were fed normal laboratory diet (0.004%cholesterol, w/w) supplemented with 1.5% cholesterol, whilst the other group were maintained on normal laboratory diet. The rabbits were anaesthetised and both carotids exposed surgically. The collar was positioned on the left artery, and the right contra lateral artery served as the sham operated control. Animals were killed at several time points between 1hr and 56days after arterial manipulation.
Histological evaluation of cochlear hair cell damage from noise-induced hearing loss in chinchillas
Authors: Harrison R.V. , Mount R.J. , White P. , Fukushima N. 
Published: June 2020

In studies which attempt to define the influence of various factors on recovery of hair cell integrity after acoustic trauma, an experimental and a control ear which initially have equal degrees of damage are required. With in a group of animals receiving an identical level of acoustic trauma there is more symmetry between the ears of each individual, in respect to function, than between animals. Figure 1 illustrates this, left and right cochlear evoked potential (CAP) audiograms are shown for two chinchillas receiving identical trauma. For this reason the contralateral ear is used as control.To compliment such functional evaluations we have devised a scoring system, based on the condition of hair cell stereocilia as revealed by scanning electron microscopy, which permits total stereociliar damage to be expressed numerically. This quantification permits correlation of the degree of structural pathology with functional changes. In this paper wereport experiments to verify the symmetry of stereociliar integrity between two ears, both for normal (non-exposed) animals and chinchillas in which each ear has received identical noise trauma.
Electron microscopy of simian immunodeficiency virus isolated from a sooty mangabey (Cercocebus Atys) in Liberia, West Africa
Authors: Munn Robert J. , Marx Preston , Brotman Betsy , Hanson Aloysius 
Published: June 2020

Simian immunodeficiency virus (SIV) is a Lentivirus that exhibits both morphological and genomic similarities to HIV. SIV has been isolated from sooty mangabeys in several primate colonies, and has been shown to be about 80% related to HTV-2. Since HIV-2 and sooty mangabeys are both indigenous to West Africa, isolation of a virus from sooty mangabeys in West Africa would be of great interest in determining the origins of these two viruses. We report here thin section transmission electron microscopy of a lentivirus from a pet sooty mangabey living in Liberia, West Africa.Peripheral blood mononuclear cells (PEMC) from a healthy pet sooty mangabey in Liberia were frozen in liquid nitrogen and shipped to the California Primate Research Center. The cells were thawed and stimulated for 72h with 0.5μg/ml Staphylococcal enterotoxin A in RPMI 1640 containing 10% fetal calf serum. 2×106PEMC were then co-cultivated with 2×106CEMxl74 cells and processed for EM.CEMxl74 cells co-cultivated with infected PBMC exhibited syncytial giant cells with patchy foamy cytoplasm (Fig 1). large numbers of virus particles were observed within these vacuoles (Fig 2).
Ultrastructural evidence for mast cell-macrophage interrelationships in the dura mater of the rat: Infrequent mast cell-nerve associations
Authors: Dimlich Ruth V.W. 
Published: June 2020

Mast cells in the dura mater of the rat may play a role in cerebral pathologies including neurogenic inflammation (vasodilation; plasma extravasation) and headache pain . As has been suggested for other tissues, dural mast cells may exhibit a close spatial relationship to nerves. There has been no detailed ultrastructural description of mast cells in this tissue; therefore, the goals of this study were to provide this analysis and to determine the spatial relationship of mast cells to nerves and other components of the dura mater in the rat.Four adult anesthetized male Wistar rats (290-400 g) were fixed by perfusion through the heart with 2% glutaraldehyde and 2.8% paraformaldehyde in a potassium phosphate buffer (pH 7.4) for 30 min. The head of each rat was removed and stored in fixative for a minimum of 24 h at which time the dural coverings were removed and dissected into samples that included the middle meningeal vasculature. Samples were routinely processed and flat embedded in LX 112. Thick (1 um) sections from a minimum of 3 blocks per rat were stained with toluidine blue (0.5% aqueous).
Microfibrillar paracrystalline inclusion (MPI) within dorsal root ganglia (DRG) of humans and ferrets in cisplatinum toxicity
Authors: Dancea S. , Montpetit V.J.A. , Mikhael N. , Stewart D. 
Published: June 2020

MPI consist of large aggregates of regularly arranged microfilaments (MF) occuring in the soma and proximal processes of neurons of humans and various animal species. These inclusions have been described in the sympathetic ganglia, the caudate, the thalamus and the substantia nigra but their occurence in the DRG has not yet been reported. In the present study, they were found in DRG of humans and ferrets treated with cisplatinum as well as in the controls.On one micron epon sections stained with methylene blue, MPI appeared as bright blue inclusions of variable size, with an average diameter of 5 μm. At the ultrastructural level, their tendency to be located at the periphery of the cytons with a predilection for the axon hillocks (Fig. 1) and the proximal unmyelinated axons (PUMA) was confirmed (Fig. 2). They formed compact bundles of straight filaments measuring 5-6 nm in diameter. Within each individual bundle, the MF were organized in a highly parallel fashion with periodic intervals of 5-6 nm and regular transverse striations 5-7 nm apart (Fig. 3).
Transmission and Scanning Electron Microscopic study of rat brain tissue after exposure to enriched versus impoverished environments
Authors: Hicks Heraline E. , Stahl Jeanne M. , Mills Adell 
Published: June 2020

Previous research has indicated that when rats are raised in enriched versus impoverisshed environments significant structural and chemical changes occur in the brain. Enriched environments usually include group housing in a large cage with many inanimate objects that are changed daily. The purpose of this study was to examine by electron microscopy, cellular morphology in rat brains after exposure to enriched versus impoverished environments.Neonatal Long-Evans hooded rats were raised in either enriched or impoverished environments from day 10 to day 70. After 60 days of enrichment, the animals were given several behavioral tests, were euthanized, the brains were surgically removed, and the septum, hippocampus, and cortex were dissected free. For scanning electron microscopy (SEM), the tissue was fixed in 2.5% glutaraldehyde in Sorensen’s phosphate buffer for 24 hr, rinsed and then post-fixed in 2% osmium tetroxide for 1 hr, dehydrated through a graded ethanol series, critical point dried, mounted on specimen holders, sputter coated and examined. Other specimens were embedded in Epon 812, sectioned for transmission electron microscopy (TEM) stained with uranyl acetate followed by lead citrate and examined. SEM demonstrated that brain tissue from rats exposed to enriched environments had more and larger neuronal vessels extending through the tissue than brain tissue from impoverished animals (Fig. 1 & 2).
Further studies on the ultrastructure of the cochlea
Authors: Wang Zhixian , Zhu Pinjin , Sun Jianhe , Song Xuezheng 
Published: June 2020

Hearing research is important not only for clinical, professional and military medicine, but also for toxicology, gerontology and genetics. Ultrastructure of the cochlea attracts much attention of electron microscopists, (1―3) but the research lags far behind that of the other parts of the organnism. On the basis of careful microdissection, technical improvment and accurate observation, we have got some new findings which have not been reported in the literature.We collected four cochleas from human corpses. Temporal bones dissected 1 h after death and cochleas perfused with fixatives 4 h after death were good enough in terms of preservation of fine structures. SEM:The apical surface of OHCs (Outer hair cells) and DTs (Deiters cells) is narrower than that of IPs (Inner pillar cells). The mosaic configuration of the reticular membrane is not typical. The stereocilia of IHCs (Inner hair cells) are not uniform and some kinocilia could be seen on the OHCs in adults. The epithelial surface of RM (Reissner’s membrane) is not smooth and no mesh could be seen on the mesothelial surface of RM. TEM.
Immunocytochemical localization of desmin and vimentin in chick embryonic myocardial cells
Authors: Sugi Yukiko 
Published: June 2020

In cultured skeletal muscle cells of chick, one intermediate filament protein, vimentin, is primarily formed and then synthesis of desmin follows. Coexistence of vimentin and desmin has been immunocytochemically confirmed in chick embryonic skeletal musclecells. Immunofluorescent localization of vimentin and desmin has been described in developing myocardial cells of hamster. However, initial localization of desmin and vimentin in early embryonic heart has not been reported in detail. By quick-freeze deep-etch method a loose network of intermediate filaments was revealed to exist surrounding myofibrils. In this report, immunocytochemical localization of desmin and vimentin is visualized in early stages of chick embryonic my ocardium.Chick embryos, Hamburger-Hamilton (H-H) stage 8 to hatch, and 1 day old postnatal chicks were used in this study. For immunofluorescence study, each embryo was fixed with 4% paraformaldehyde and embedded in Epon 812. De-epoxinized with sodium methoxide, semithin sections were stained with primary antibodies (rabbit anti-desmin antibody and anti-vimentin antibody)and secondary antibody (RITC conjugated goat-anti rabbit IgG).
The Z band in skinned fibers of a slow skeletal muscle
Authors: Goldstein Margaret A. , Schroeter John P. 
Published: June 2020

We have shown that Z bands in rat soleus muscles exhibit two structural states. The small square (ss) form is seen in relaxed intact muscle and the basketweave (bw) form is seen in maximally activated muscle (tetanized and in rigor). The Z spacing measured in the bw form is 20% larger than that in the ss form. The dimensions of the two Z band lattice forms in these muscle states are independent of A band spacing. Skinned fibers have been used to assess various muscle properties and expansion of the A band has been observed in some cases. We have examined the effects of chemical skinning on Z band form and dimension and A band spacing in relaxed muscle.Rat soleus muscles were dissected and tied to applicator sticks and removed to a solution of 1% Triton X-100 in lOmM PIPES buffer with 5mM EGTA and lOmM ATP overnight at 4°C, then rinsed with the PIPES buffer with EGTA and ATP only for 4 hours.
Electron microscopic analysis of the microtubular structure of HEp-2 cells
Authors: Kellermayer Miklós S.Z. , Henics Tamás , Szücs György , Pollack Gerald H. 
Published: June 2020

The HEp-2 cell line was first established by Moore, et al. and today it serves as a widely used subject for a large variety of microbiological and cell-biological experiments. A tubular structure of unknown origin and function has been described first in virally infected, and later in uninfected HEp-2 cells. However, this tubular structure has not been further analyzed. We performed transmission (TEM) and whole cell mount electron microscopic studies of monolayer HEp-2 cells to morphologically describe the structure and relate it to other organelles of the cell.For embedding, HEp-2 cells were grown on glass coverslips in Eagle's minimal essential medium. 24 hours after passage, three types of procedures were carried out: (1) The cells were fixed with 2.5% glutaraldehyde in 0.14 M Na-cacodylate buffer. (2) The cells were treated for 10 min. with Hank's solution containing 0.2% Brij-58 and 2.5% glutaraldehyde. Fixation was completed with 2.5% glutaraldehyde in 0.14 M Na-cacodylate. (3) Cells were treated with 0.2% Brij-58 in Hank’s solution for 10 min. Subsequently, they were fixed with 2.5% glutaraldehyde in 0.14 M Na-cacodylate.
Fine structure of the rectal papillae of the oriental fruuit fly,Dacus dorsalisHendel (Tephritidae, Diptera Insecta)
Authors: Wen-Yung Len , Lin Mei-Jung 
Published: June 2020

Four cone-shaped rectal papillae locate at the anterior part of the rectum inDacus dorsalisfly. The circular base of the papilla protrudes into the haemolymph (Fig. 1,2) and the rest cone-shaped tip (Fig. 2) inserts in the rectal lumen. The base is surrounded with the cuticle (Fig. 5). The internal structure of the rectal papilla (Fig. 3) comprises of the cortex with the columnar epithelial cells and a rod-shaped medulla. Between them, there is the infundibular space and many trabeculae connect each other. Several tracheae insert into the papilla through the top of the medulla, then run into the cortical epithelium and locate in the intercellular space. The intercellular sinuses distribute in the posterior part of the rectal papilla.The cortex of the base divides into about thirty segments. Between segments there is a radial cell (Fig. 4). Under the cuticle, the apical cell membrane of the cortical epithelium is folded into a regular border of leaflets (Fig. 5).