bluuebunny/crossref_metadata_2025 huggingface dataset:
The extracellular matrix of echinoderm and amphibian eggs: Visualization in quick-frozen, deep-etched, and rotary-shadowed specimens
Authors: Bonnell Barry , Larabell Carolyn , Chandler Douglas
Published: June 2020

Eggs of many species including those of echinoderms, amphibians and mammals exhibit an extensive extracellular matrix (ECM) that is important both in the reception of sperm and in providing a block to polyspermy after fertilization.

In sea urchin eggs there are two distinctive coats, the vitelline layer which contains glycoprotein sperm receptors and the jelly layer that contains fucose sulfate glycoconjugates which trigger the acrosomal reaction and small peptides which act as chemoattractants for sperm. The vitelline layer (VL), as visualized by quick-freezing, deep-etching, and rotary-shadowing (QFDE-RS), is a fishnet-like structure, anchored to the plasma membrane by short posts. Orbiting above the VL are horizontal filaments which are thought to anchor the thicker jelly layer to the egg. Upon fertilization, the VL elevates and is transformed by cortical granule secretions into the fertilization envelope (FE). The rounded casts of microvilli in the VL are transformed into angular peaks and the envelope becomes coated inside and out with sheets of paracrystalline protein having a quasi-two dimensional crystalline structure.
Nuclear pore number changes in Sertoli cells at different stages of the spermatogenic cycle
Authors: Cavicchia Juan C. , Morales Alfonsina
Published: June 2020

Sertoli cell population is not functionally homogeneous along the spermatogenic cycle of the seminiferous epithelium. The maximal binding of 125 I-FSH by Sertoli cells was found at stages XIII-I where as mode rate binding occurs at stages IX-XII. Also important physiological events take place in the first mentioned stages like meiotic divisions and the initiation of RNA synthesis in haploid cells. As nuclear pores are dynamic structures whose number varies according with the cellular metabolic requirementsys we explored the nuclear pore density in Sertoli cells in stages XIII-I versus stages IX-XII. Albino rats were used. Both sets of stages were recognized and isolated by transillumination under a dissecting microscope (stages XIII-I with weak spots and IX-XII with pale absorption). Tubular segments were fixed in glutaralde-hyde-cacodylate buffer, immersed in 30% glycerol, freeze-fractured in a Balzers BAF 301 apparatus at-110°C and examined under a Seimens Elmiskope I electron microscope.
The mechanism of male infertility
Authors: Liankai Dang
Published: June 2020

There are two types of male infertilities in experimental animals including humanbeing. The first is a man-made infertility for the purpose of contraception; the second is caused by disease which could damage the spermatogenesis. According to the source of pathology, it can be divided into internal infertility and external infertility. Some of invironmental factors such as γ-ray, x-ray, nutron, micro wave and soon and also some of chemical factors could induce the disorder of spermatogenesis, sperms lost the ability for the fertilization or even disappear, Internal sourse means genetic disease or reproductive disease, in that cases the micro invironment for spermatogenesis is disordered; so there are a lot of abnormal sperms in the semen which could not perform the function for the fertilization.

The purpose of this paper is to collect all experimental results what we haved one in the past, to compare them and to try finding out changes in commonand difference among them.
Simultaneous visualization of biological structures in a hybrid STEM and STM
Authors: Stemmer A. , Reichelt R. , Aebi U. , Engel A.
Published: June 2020

Scanning tunneling microscopy opens attractive perspectives in structural biology such as direct imaging of surface topography, elasticity and possibly chemical composition of individual molecules as well as assemblies thereof at high resolution without beeing restricted to vacuum operation as conventional electron microscopy. However, since the electronic structure of native as well as dehydrated biological macromolecules is generally not known it is of utmost importance to understand the interaction between the tunneling tip and the bare specimen surface if reproducible and interpretable imaging is to be achieved. The direct comparison of structural data obtained from the same object by STEM and STM not only provides a stringent test for correct image interpretation but also allows to quantify specimen damage as well as to explore new specimen preparation techniques. The latter appears to be particularly important since reproducible imaging has mainly been achieved on metal-coated specimens. New specimen preparation techniques may specifically take advantage of conducting negative stains or subtle chemical modifications which would increase the conductivity of the biological material.
High-Resolution SEM and Freeze Fracture Studies of Human Retina
Authors: Szczesny Piotr J. , Claugher Don
Published: June 2020

The fine structure of human retinae were investigated with use of TEM and High Resolution SEM combined with freeze fracture and osmium maceration technique paying partic ularattention to the morphology of photo receptor cells. Gluteraldehyde fixed retin al samples from 8 individuals of different age groups, were examined. Fixation time varied from 0 to 3 hours post mortem.

Results showed good corelation between the TEM and HRSEM Fig 1-2. HRSEM enabled a detailed study of a several plasma membrane domains of rods and cones. It was possible to examine the inner limiting membrane formed by podocytes of Muller cells Fig 3, and also the cell junctions formed by rods, cones and Muller cells at the level of the outerlimiting membrane, Fig 4. HRSEM demonstrated particularly well the area of the photorecept or connecting cilium and the proximal portion of the outer segment in photoreceptors.
Effects of Antihypertensive Drug Treatments on Cerebral Arteriolar Structure and Function
Authors: Ghoneim Shams , Hajdu Michael , Siems Jay , Baumbach Gary
Published: June 2020

Cerebral arterioles undergo hypertrophy and become more distensible during chronic hypertension(1). These changes are accompanied by a disproportionate increase in volume density of the more distensible components of the arteriolar wall(2). We have recently demonstrated that antihypertensive therapy with hydralazine or an angiotensin converting enzyme (ACE) inhibitor (cilazapril) prevented hypertrophy of cerebral arterioles(3). In addition, cilazapril, but not hydralazine prevented the increase in cerebral arteriolar distensibility that accompanies hypertension(4). The goal of this study was to determine whether treatment of hypertension with either hydralazine or cilazapril caused alterations in the composition of the walls of cerebral arterioles.

We studied pial arterioles in 6 month old, stroke-prone, spontaneously hypertensive rats(SHRSP). 24 SHRSP were randomly divided into 3 groups of 8 animals. The first group received Cilazapril(10mg/Kg/day) in its drinking water. The second group received Hydralazine (100 mg/Kg/day) in its drinking water. The third group was left untreated as a control.
Confocal Scanning Slit Microscopy using a Linear Detector Array
Authors: Plant Randall L. , Burns David H.
Published: June 2020

Confocal microscopy has been shown to produce improved lateral and axial image resolution compared with conventional microscopy. Image degradation due to scattering is reduced since only those portions of the specimen in the focal plane of the objective will contribute to image formation at the light detector. Previous work has shown that slit apertures can be used instead of pinholes to achieve the advantages of confocal microscopy with increased illumination and deceased scan line artifact. Slit scanning microscopes are also simpler in design than pinhole scanners but their aperture forms an asymmetric point spread function. We have developed a confocal scanning microscope utilizing a slit aperture and a linear charge coupled device (CCD) as a photodetector. We characterize its resolution for imaging a thick luminescent specimen as a function of scanning axis, wavelength, and tissue depth.

A schematic of the new confocal microscope is shown in figure 1. The illumination source is a 150 watt incandescent bulb.
The Quantitative Ultrastructure of the Heart Muscle of Japanese Quail by Hypergravitation, Hypodynamy and Combination
Authors: Bózner Anton , Gažo Mikuláš , Dostál Jozef
Published: June 2020

It is anticipated that Japanese quail /Coturnix coturnix japonica/ will provide animal proteins in long term space flights. Consequently this species of birds is of research interest of international space program INTERCOSMOS. In the year 1987 we reported on an experiment /2/ in which the effect of chronic acceleration of 2 G hypergravitation, the hypodynamy and the simultaneous effect of chronic acceleration and the location in the centre of the turntable of the centrifuge on the protein fractions in skeletal muscles was studied. The ultrastructure of the heart muscle was now in this experiments examined as well.

Japanese quail cockerels, aged 48 days were exposed to 2 G hypergravitation /group IV/ in a 6,4 m diameter centrifuge, to hypodynamy /group III/ and their combination /group V/, respectively for 6 days / Fig.1/. The hypodynamy in group III was achieved by suspending the birds in jackets without contact the floor. The group II was located in the centre ofthe turntable of the centrifuge. The control group I. was kept under normal conditions. The quantitative ultrastructure of myocard was evaluated by the methods of Weibel/3/ - this enables to determine the number, relative size and volume of mitochondria volume of single mitochondria, defficiency of mitochondrial cristae and volume of myofibrils.
Microtubule Dynamics and Organelle Transport in Reticulomyxa
Authors: Chen Yih-Tai , Euteneuer Ursula , Johnson Ken B. , Koonce Michael P. , Schliwa Manfred
Published: June 2020

The application of video techniques to light microscopy and the development of motility assays in reactivated or reconstituted model systems rapidly advanced our understanding of the mechanism of organelle transport and microtubule dynamics in living cells. Two microtubule-based motors have been identified that are good candidates for motors that drive organelle transport: kinesin, a plus end-directed motor, and cytoplasmic dynein, which is minus end-directed. However, the evidence that they do in fact function as organelle motors is still indirect.

We are studying microtubule-dependent transport and dynamics in the giant amoeba,Reticulomyxa. This cell extends filamentous strands backed by an extensive array of microtubules along which organelles move bidirectionally at up to 20 μm/sec (Fig. 1). Following removal of the plasma membrane with a mild detergent, organelle transport can be reactivated by the addition of ATP (1). The physiological, pharmacological and biochemical characteristics show the motor to be a cytoplasmic form of dynein (2).
Ultrastructural comparison of amyloid-like glyomerulopathy
Authors: Caughey R.C. , Kelly C.E.
Published: June 2020

Without transmission electron microscopy cases of amyloidosis-like glomerulopathy may be erroneously considered to be amyloidosis, diabetic or membranous nephropathy. Mesangial widening and increased matrix, and capillary basement membrane thickening are features common to amyloid-like glomerulopathy, amyloidosis, and diabetic renal problems. Amyloid-like immunofluorescence may be positive for IgG, and C3 within the mesangium and capillary walls suggesting possible membranous nephropathy. Some cases appear to represent light chain nephropathy, which is known to result in crystalline-like ultrastructural deposits. Identification of amyloid-like glomerulopathy is made by Congo Red negativity and characteristics of ultrastructural fibrils.

The renal biopsies from all patients were fixed in 2.5% glutaraldehyde, rinsed in Millonig’s phosphate buffer, and post fixed in 1% osmium tetroxide. They were then en bloc stained with 1% uranyl acetate, rinsed with Walpole’s non-phosphate buffer, dehydrated with a graded series of ethanols and embedded with Epon 812 epoxy resin. Ultramicrotomy thin sections were post-stained with uranyl acetate and lead citrate and scanned using a JEOL JEM 100C.
Dermatopathia Pigmentosa Reticularis
Authors: Bielenberg U. , Burns W. , Clark Lambert W. , Schwartz R.A. , Marquet E.
Published: June 2020

Dermatopathia pigmentosa reticularis (DPR) is a reticulate pigmentary disorder of as yet unclear inheritance that was first described in 1958. Since then only an additional eight cases have been reported, all in the European literature. To our knowledge, this is the first case from the United States of America and the first with an ultrastructural study.

The patient is a 44-year-old man of mixed Black, Hispanic and American Indian descent with generalized, variably pigmented skin over the entire body present since birth.

A punch biopsy of pigmented forearm skin was taken for light microscopy which demonstrated hyperkeratosis, an intact granular layer, and epidermal atrophy with focal liquefaction degeneration of the basal cell layer. The dermis showed pigment incontinence. Direct immunofluorescence was negative for immunoglobulins and complement at the basement membrane zone. A second skin biopsy of an elbow plaque showed the above changes except for the alteration of the basal layer.
Ultrastructural and Morphometric Analyses of Type II Pneumocytes in Chronic Inflammation-- A Response to Quartz Inhalation
Authors: Zhonfei Qian , Su M.L. , Chi E.Y.
Published: June 2020

Induced lung injury by various particles can lead to inflammation, and can later develop hyperplasia of type II pneumocyte in the alveoli. The response of inflammatory process resulted in a epithelial cell proliferative response is not clearly understood. Alveoar macrophages and leukocyte products may have an important role in the initil injury of the alveolar surface. In our previous study, quartz inhalation caused a marked 60 fold increase in lavaged phospholipids. The change was the greatest at 4 weeks after exposure, and slightly reduced at 6 months. In this study we observed ultrastructurally that the response of type II cells in quartz induced injury is persisted in lung. Two matched groups of 50 male Sprague-Dawley adult and specific pathogen free rats were exposed to either quartz or clean air in a Rochester exposure chamber 6 hours daily for a duration of 10 days. Animals were sacrificed and lungs were fixed at various recovery times for morphological and morphometric analyses.
Study of Wheals on Gastric Mucosa in Patients with Chronic Uticaria by Scanning and Transmission Electron Microscopy
Authors: Wang Jianhua , Hu Shaopeng , Chu Fei , Sun Shegzheng , Zhang Jinzhang
Published: June 2020

Urticarial wheal is due to the leak of proteins and fluids to extravascula by increased capillary permeability. Edematous erythema and wheals located in the surface of gastric mucosa were observed by gastroscopy. The present contribution is the first in the international extent of the observation of wheals on gastric mucosa of 38 patients with chronic urticaria with the transmission electron microscope (TEM) and scanning electron microscope (SEM).

Gastroscopies were performed on 38 patients with chronic urticaria during episodes ofcutaneous wheals. Biopsy specimens were taken from gastrical wheals from 38 patients. The EM specimens were routinely prepared. Linder the SEM, the surface of the epithelial cells of wheals on the gastric mucosa appeared slightly edematous and rough. Intercellular space of the epithelium became more narrow and shallow. The structure of microvillae on gastric mucosa epithelial cells could be seen, but appeared short and decreasing in amount. Under the TEM, it was found that the stomach mucous membrane was edematous.
Osmolarity and Artificial Cell Damage in Ischemic Myocardium
Authors: Montione Richard , Ashraf Muhammad
Published: June 2020

Osmolarity of a fixative vehicle has long been known to have an effect on the tissue preservation. An increase in tissue osmolarity occurs in ischemia-damaged tissue and affects the morphology. In this study, we examined cellular changes in ischemic rat myocardium induced by varying fixative toxicity.

Rats were sacrificed by decapitation and the hearts immediately removed and retrogradily perfused through the aorta with anoxic Kurbs-Henseleit medium. Hearts were then placed in a bag with a small amount of medium at 37°C for 90 minutes. Hearts were perfusion-fixed using 2% glutaraldehyde in 0.1 M cacodylate buffer pH -7.3 at three osmolarities. The isotonic buffer was adjusted to 311 mOsm/kg using D-manitol. Hypertonic buffers were adjusted to 375 and 400 mOsm/kg. One-half hour after perfusion fixation, the hearts were sliced and cut into small blocks and allowed to fix overnight at 4°C. Blocks were post fixed in osmium, en bloc stained in uranyl acetate, dehydrated in ethanol and embedded in Spurr medium.
Electron microscopic study of effects of Polyactin A on the colonies cells of spleen
Authors: Xiang Yuan Zeng , Ying Zhang
Published: June 2020

Electron microscopic studies on the colonies cells of spleen were presented.

Polyactin A is a new immunological enhancement agent which was developped in China for the first time. It is a polysaccharide extracted from cultured a-hemolytic streptococcus No. 33 in the mouth. Clinical observation suggests that the drug has marked inhibiting effects on some tumors and can increase the number of leucocytes, enhance immunity of the organism. Polyactin A has also a good effect on aplastic anemia and it is a new drug in treatment of aplastic anemia. However, its mechanism isn't understand.

In order to investigation this problem, electron microscopic observation on the colonies cells of spleen (CFU-s) were studied and effects of Polyactin A on hemopoietic stem cell of marrow were also discussed. The results showed that Polyactin A can make marked effects on ultrastructures of colonies cells of spleen (CFU-s). Stem cells dilated and nucieus showed inregularity in shape. Chromatin in the nucleus which has enlarged nucleolus was compact and euchromatin increased. There were abundant organelles such as rough endoretigrum, ribsomes and mitochondria in the cytoplasma.
Ultrastructural pathology of sulfur mustard toxicity and the protection afforded by niacinamide
Authors: Petrali J. P. , Oglesby S. B. , Mills K.R.
Published: June 2020

We have been studying ultrastructural lesions associated with sulfur mustard (HD) toxicity of animal models and cells-inculture. Our goal is to develop an ultrastructural data base of sulfur mustard lesions with the anticipation that persistent subcellular features of HD-induced toxicity may prove useful in predicting and measuring prophylactic and therapeutic strategies. At this time we have reported the ultrastructural pathology of HD lesions in four model systems 1) the human-skin grafted athymic nude mouse, 2) the hairless guinea pig, 3) human lymphocytes in vitro and 4) human keratinocytes in culture. Results of these studies suggested that the ultrastructural pathology at the dermal - epidermal junction of the animal skin models was unequivocal involving basal cell degeneration and a disabling of anchoring filaments in the formation of subepidermal microblisters. In the cellular models, as with the skin basal cell, early persistent ultrastructural features were blebbing of the perinuclear envelope, paranuclear vacuolation, nuclear condensation and defects in the plasmalemma.
Cell biological studies of primary and metastatic tumors of the rat prostate
Authors: Heidger Paul M. , Kutschke William J. , Bataineh Ziad
Published: June 2020

The widespread occurrence and high mortality rate in older men associated with disseminated adenocarcinoma of the prostate provide a strong impetus for basic studies of the normal and neoplastic prostate gland. The present studies have been undertaken with the objective of gaining a fuller appreciation of histo- and cytologic interrelationships between metaplastic prostatic tumors and their host organs.

The Dunning rat adenocarcinoma has provided a model for some years for the study of primary prostatic tumors, and recently a tumor subline has been identified which preferentially metastasizes to lung (Dr. David M. Lubaroff, U. IA). Cells of the metastatic subline colonize lung following intravenous injection, and produce widespread lesions within the lung parenchyma, and deep to the visceral pleura, in a matter of weeks. Correlative light microscopic (LM), transmission (TEM) and scanning (SEM) electron microscopic studies have been conducted of both the primary Dunning tumor, and the metastatic lesions within lung, using routine preparative techniques. Morphological examination has been conducted in concert with immunocytochemical localization of components of the extracellular matrix, within both lung and tumor, and with studies of the growth and attachment characteristics of tumor cells cultured in wells coated with such extracellular matrix components as fibronectin, laminin, and collagen types I and IV.
Ultrastructural characterization of cytomegalovirus infected and interferon producing human foreskin cells
Authors: Rodriquez J. , Moninger T.O. , Walker D. , Moore K. C.
Published: June 2020

Published work indicates that human cytomegalovirus (CMV) is sensitive to the action of beta interferon (HuIFNb) and can induce the production of INF in cultures of human foreskin (HF) cells. These findings are consistent with a role for endogenous IFN in the establishment and maintenance of persistent CMV infections. Moreover HF cells can be primed with IFN and these primed cells can be induced to produce large concentrations of IFN after exposure to CMV. These findings support the hypothesis formulated to explain the larger-than-expected concentrations of IFN detected in cultures exposed to low MOIs (<0.01), namely, that the phenomenon observed involved endogenous priming, that is production of IFN by the small percentage of the cells infected by the inoculum virus. This results in priming of the remaining cells by IFN, and finally induction of the primed cells by progeny CMV released from the cells infected originally.

To lend support to this hypothesis we will follow the attachment, penetration, and release stages of the CMV replication by transmission and scanning electron microscopy.
Observation of basal cells in the olfactory epithelium after axotomy
Authors: Suzuki Yuko , Takeda Masako
Published: June 2020

In the olfactory epithelium of mice, cytokeratin was present in the basal cells but not in the olfactory cells. Our previous study using antikeratin antibodies showed that the basal cells were columnar or pyramidal in shape in the early postnatal period, but became flat in adult mice. In this study, structural changes of the basal cells after axotomy were investigated by immunohistochemistry, transmission electron microscopy (TEM), and scanning electron microscopy (SEM).

The unilateral olfactory nerves of adult mice were sectioned at the level of the lamina cribrosa. The mice were sacrificed 4, 8-10, and 14 days postoperatively. The olfactory mucosae were removed, frozen with freon 22, and cut on a cryostat at 10 μm. The sections were stained by the PAP method using a PAP kit. The antikeratin antibody (PKK 2) against pig kidney epithelial cell line, which reacts with 40, 46, 48, and 54 kd subunits (Immunotech), was used. To label the dividing cells, bromodeoxyuridine (BrdU) was administered to mice each postoperative day 1 hour before sacrificing. The presence of BrdU was detected imrnunohistochemically using anti-BrdU antibody (Becton-Dickinson).
Comparative study of ultrastructure of HIV and SIV
Authors: Nakano Takashi , Imura Shunro , Nakai Masuyo
Published: June 2020

The ultrastructural feature of AIDS viruses (HIV and SIV) was observed by ultrathin-sectioning and negative staining method, and the surface structures of these viruses were compared.

HIV-1 group including, HTLV-III and LAV-1 were used. And in HIV-2 group, LAV-2, which was isolated from a Senegalese AIDS patient, and GH-1, which was isolated from a Ghanan AIDS patient, were used. SIV group was used AGM-1, which was isolated from an African green monkey. The virions were used which was produced from Molt-4 cells after the infection of each viruses of these strains. The infected cells and viral particles, which were collected by centrifugation were fixed with 2% glutaraldehyde (GA), washed with PBS, and postfixed with 1% osmium tetroxide. The specimens were dehydrated in graded ethanol, and embedded in Epon 812. The thin sections were stained with uranyl acetate and lead citrate. On the other hand, for negative staining, 25% GA was added to the supernatant culture fluid and finally concentrated on 2% GA. Then virions were collected by ultracentrifugation.
The effects of Cyclosporin-A (CYA) on the Ultrastructure of Gingival Mast Cells (GMC) in Behcet's disease (BD)
Authors: Arda Oktay , Noyan Ulkü , Yilmaz Selgçk , Taşyürekli Mustafa , Seçkin İsmail , Yılmazer Selma , Satıroğlu Güngör
Published: June 2020

Turkish dermatologist, H. Beheet described the disease as recurrent triad of iritis, oral aphthous lesions and genital ulceration. Auto immune disease is the recent focus on the unknown etiology which is still being discussed. Among the other immunosupressive drugs, CyA included in it's treatment newly. One of the important side effects of this drug is gingival hyperplasia which has a direct relation with the presence of teeth and periodontal tissue. We are interested in the ultrastructure of immunocompetent target cells that were affected by CyA in BD.

Three groups arranged in each having 5 patients with BD. Control group was the first and didn’t have CyA treatment. Patients who had CyA, but didn’t show gingival hyperplasia assembled the second group. The ones displaying gingival hyperplasia following CyA therapy formed the third group. GMC of control group and their granules are shown in FIG. 1,2,3. GMC of the second group presented initiation of supplementary cellular activity and possible maturing functional changes with the signs of increased number of mitochondria and accumulation of numerous dense cored granules next to few normal ones, FIG. 4,5,6.
Various microtubular patterns in dorsal root ganglia (DRG) in pyridoxine neurotoxicity
Authors: Montpetit V.J.A. , Dancea S. , Tryphonas L.
Published: June 2020

The term “microtubule” (MT) has been ascribed to a complex group of subcellular structures deploying at least two common characteristics: a hollow cylindrical shape and a diameter of less than 30 nm. Some authors, however, regard MT as composed of tubulin with well known roles in the organization of the cytoskeleton and different cellular functions such as secretion, mitosis, and motion. In alteration of the neuronal cytoskeletal organization in neurotoxicity, their tubulin composition has usually been unquestioned. Recently observed unusual MT aggregation patterns in pyridoxine neurotoxicity definitely raised questions as to the composition of some of the groups of microtubules which fulfill the general definition. At least three different patterns of MT aggregations were seen in neuronal cytons of DRG of dogs treated with high doses of pyridoxine.

The large MT aggregates made up of numerous superimposed sheets of MT in parallel arrays and having different orientation in close proximity to ribosomes and membranes of rough endoplasmic reticulum (RER) have already been reported.
Evaluation of hippocampus in rhesus monkeys after chronic (1-year) inhalation exposure to marijuana: II. Morphometric methods
Authors: Wilson S.W. , Andrews A.M. , Scallet A.C. , Ali S.F. , Bailey J.R. , Paule H.G. , Slikker W.
Published: June 2020

An innovative method was used to collect data for morphometric analysis of synaptic measurements. Negatives of the CA3 region of the hippocampus were obtained as described by Andrews et al., 1990, and evaluated by computersupported image analysis. Negatives of 4000X and 40,000X magnification were used to measure synaptic density and width, respectively. The image analysis system (IAS) used an IBM-AT compatible computer with a frame grabber (Imaging Research Inc.). This particular system can measure either straight line distance (rubber line) or curved two point distances (draw line).

For synaptic density, the IAS was calibrated in angstroms at a magnification of 4000X. A log file was created for each negative in which the measurement for each synapse was stored. The negative was placed on a transparency with grids 9 mm square to ensure that the entire negative was scanned. The image was displayed on a multicsync monitor using a high resolution camera (Applied Intelligent Systems Inc.). When a synapse came into view, the image was digitized on the monitor (Fig. 1 A and B) and stored in digital form.
Ultrastructure of “putative” neurotransmitter sites in Schistosoms mansoni Miracida
Authors: Ruth Jones Betty , Chi-Tung Pan Steve
Published: June 2020

Schistosomiasis has been described as “one of the most devastating diseases of mankind, second only to malaria in its deleterious effects on the social and economic development of populations in many warm areas of the world.” The disease is world wide and is probably spreading faster and becoming more intense than the overall research efforts designed to provide the basis for countering it. Moreover, there are indications that the development of water resources and the demands for increasing cultivation and food in developing countries may prevent adequate control of the disease, and thus, the number of infections are increasing.

Our knowledge of the basic biology of the parasite causing the disease is far from adequate. Such knowledge is essential if we are to develop a rational approach to the effective control of human schistosomiasis. The miracidium is the first infective stage in the complex life cycle of schistosomes.
Scanning Electron Microscopy of neuronal cell bodies isolated from the adult mammalian central nervous system
Authors: Liu Wenshu , Franklin Bailey J. , Limwongse Visaka , DeSantis Mark
Published: June 2020

Action potentials generated in a motor neuron reflect the summation of synaptic inputs it receives from other neurons. Those synapses occur at points of contiguity between the presynaptic boutons and the surface of the motor neuron. Evidence that the density of axosomalic boutons on motor neurons varies directly with the size of the motor neuronal soma is indirect. Counts of the number of boutons per unit area at the surface of the motor neuron’s cell body using scanning electron microscopy (SEM) would allow an independent, direct assessment of that inference. We describe here procedures for consistently isolating the somas of CNS neurons, specifically those associated with the adult rat’s trigeminal nerve, so that axosomatic boutons can be seen by SEM (Figures 1 and 2).

Adult male and female rats were anesthetized and then perfused with saline followed by 4% paraformaldehyde. The brain stem was removed and sectioned at 200 um thickness on a vibratome. Sections containing the trigeminal motor and mesencephalic nuclei were pinned to Sylgard-lined dishes containing phosphate buffer (0.1 M, pH 7.2).
Elastic behavior and arrangement of titin filaments in the I-band
Authors: Trombitás Károly , Pollack Gerald H. , Wright John , Wang Kuan
Published: June 2020

Immunoelectron microscopic studies have revealed that the I-band domain of the titin filament behaves elastically. We report experiments that suggest that titin forms independent, highly elastic filaments in the I-band, except in the N1-line region near the Z-line.

Freshly prepared bundles of rabbit psoas muscle fibers were quickly frozen and broken into small pieces under liquid nitrogen to fracture sarcomeres at the I-band region. The still-frozen specimens were thawed during fixation with paraformaldehyde (3.7%) in PBS to allow elastic filaments to retract. The muscle pieces were then labelled with monoclonal anti-titin (RT 13 and Sigma), followed by treatment with second antibody (goat anti-mouse).

This method gave an excellent decoration pattern. The position of the titin epitope is symmetrical relative to the Z-line (Figure 1). However, in regions where the sarcomeres were broken at the A-I junction, the epitopes are no longer symmetrical about the Z-line (Figure 2); the broken thin filaments remained in their original position, but the titin filaments in the broken half retracted, independently of the thin filaments, forming a dense band just near the Zline (arrow).
Scanning Electron Microscopy of soft-bodied tephritid larvae
Authors: Paul R. , Kapoor V. C.
Published: June 2020

The soft body of dipteran larva has been posing a difficulty for entomologist to go for scanning electron microscopy. Dehydration by the conventional methods results in crumpling of the larval integument thereby distorting the minute details. The cuticle is impermeable to various types of fixatives and its puncturing with needle causes severe distortion of structure due to haemoiymphloss. To avoid this a new method was developed to prepare specimen for scanning electron microscopy. The specimen was kept in doubled is tilled deionized water at 60°C for half an hour before further treatment. It was sonicated in mild detergent (Sodium bicarbonate) for 30 sec. It was again washed with deionized water and specimen was placed in modified super skiper's solution (Grodowitz et al., 1982) and then rinsed twice in Carl's solution, after dehydration through ethanol series, critical point drying was done. Specimen was coated with gold pulludium and photographed by using JEM - 1200 EX (Jeol) electron microscope and Indu Panchromatic 125 ASA black and white film.
Ultrastructural study of the filamentous pelvic fins of the anabanthid fish Trichogaster trichopterus
Authors: Fanta E. , Eiras-Stofella D. R. , Mehler B. , Ortolani C. F.
Published: June 2020

As have many other Anabanthid fish, Trichogaster trichopterus has filiform modified pelvic fins. In this species they are used for equilibrium or for communication between individuals, in a deliberate sequence of movements, as could be observed. Like true barbels, they seem to detect through taste, mainly acidity.

Through SEM and TEM it was possible to describe the structures that are responsible for these varied uses of the “barbels.” Fixation was in glutaraldehyde 2.5% in 0.2M phosphate buffer, and post fixation in 1% osmium tetroxyde, in the same buffer. For SEM the dehydration was in a graded ethanol series, and the critical point was reached with liquid CO2; the coating was with gold. A Philips TEM and Philips SEM were used.

The epithelium is stratified; the cells are well fixed through cell junctions, and with frequent interdigitations (Fig. 3). The outer layer has light polygonal cells, with external concentric ridges (Fig. 1). A second type of darker cells can also be observed. Many taste buds are observed, mainly from the median to the top region (Fig. 1).
Ultrastructural observations on hemocytopoiesis in embryos of the horseshoe crab, Tachypleus tridentatus
Authors: Liang Ping , Cheng Ting-Kai , Wu Yi-qin , Wu Wei-hong
Published: June 2020

The main type of horseshoe crab hemocytes is amebocyte (granulocyte), whose lysate is a very sensitive indicator of endotoxin, and has been used widely in the medical and pharmaceutical fields. The origin, site of production and course of development of amebocyte haven’t been solved yet. It is still in dispute if there is another cell type in the circulating hemolymph. We have studied the fine structure of amebocytes from adult Tachypleus tridentatus, and found a small number of immature and maturing amebocytes, a few being in mitosis, and considered these findings to be full proof that some amebocytes could proliferate and mature during circulation. This paper represents a continuation of our previous work, and reports the observations on hemocytopoiesis in embryos of Tachypleus tridentatus.

The embryos were obtained by artificial insemination and incubation. The specimens for light microscopic studies consisted of 17 embryos 13-21 days old, 3 embryos and 3 trilobite larvae shortly before and after hatching, while those for electron microscopy included 6 embryos of 13-19 days, 1 late embryo and 1 trilobite larva. All specimens were processed in a routine manner.
Lectins bind differentially to rat olfactory and nasal respiratory cilia and microvilli: A rapid-freeze freeze-substitution lowicryl K11M embedding and deep-etch study
Authors: Menco Bert Ph. M.
Published: June 2020

Olfactory cilia have membranes that contain odorant receptors and an apparatus to transduce the odorous message into a code comprehensible to the rest of the cell and the brain. Membranes of these cilia have a variety of cellsurface proteins to do this. Ultrastructural freeze-fracture and freeze-etch studies have implied that this is really true. Biochemical and electrophysiological studies on olfactory epithelia with lectins have suggested that a major part of these proteins are glycoproteins. Therefore, binding of colloidal-gold conjugated lectins was studied in cilia and microvilli of rat olfactory with cilia and microvilli of nasal respiratory epithelial surfaces as comparison. This was done in sections of rapidly-frozen, freeze-substituted specimens embedded in Lowicryl K11M or, for wheat germ agglutinin ( WGA) alone, in deep-etched replicas. Olfactory dendritic endings and cilia labeled with WGA and, faintly, with soybean agglutinin (SBA); olfactory supporting-celi microvilli bound only Dolichos biflorus agglutinin (DBA). Microvilli of an infrequent cell bound peanut agglutinin (PNA), SBA, and WGA. Relative to olfactory cilia these microvilli labeled more strongly with the last two lectins. The cell resembles a presumptive sensory oneR. Cilia of nasal respiratory cells bound WGA and, somewhat more weakly, PNA; microvilli of respiratory cells bound all four lectins. In respiratory ciliated cells cilia and microvilli of the same cell type showed a quite different pattern of labeling.
Expression of viral particles by raw 264.7 mouse macrophage cells after treatment with lipopolysaccharide
Authors: Blystone Robert , Kiel Johnathan , Parker Jill , Collumbs Chris
Published: June 2020

The RAW 264.7 mouse macrophage cell line “was established from the ascites of a tumor induced in a male BAB/14 mouse by the intraperitoneal injection of A-MuLV.” Abelson murine leukemia virus (A-MuLV) is an RNA retrovirus that can cause transformation of certain cells. The AMuLV RNA is 5,600 bases long and forms the familiar nucleoid associated with C-type virus morphology. Raschke et al. further stated that “the other macrophage line, RAW 264, fails to secrete detectable virus particles and is negative in the XC plaque formation assay, as well as the fibroblast transformation assay for Abelson virus but becomes positive for Abelson virus production after rescue by Moloney leukemia virus.” Contrary to the original citation, we are reporting that lipopolysaccharide treated RAW cells will shed C-type virus without a Moloney rescue.
The variations of virus shape and size in different preparations
Authors: Mingxiao Ding , Renjie Jiao , Fengxia Liang , Zhonghe Zhai
Published: June 2020

Envelope is a very important structure for viral attachment and entry into the host cell, but it is also a morphologically variable portion of enveloped viruses. Studying the fine structure of enveloped viruses, we noticed that different sample preparations of viruses resulted in the change of viral size and shape to some extent, which we believe was caused by the variation of the viral envelope. Four typical enveloped viruses: IBRV (Infectious Bovine Rhinotracheitis Virus), GPV (Goat Pox Virus), SbV (Sindbis Virus) and VSV (Vesicular Stomatitis Virus) were investigated in our experiments.

Host cells infected with IBRV, GPV, SbV and VSV respectively were fixed with 1-5% glutaraldehyde in Hank's buffer when the cytopathic effects appeared in 50-70% of the cells, then the specimens were treated respectively with different conventional methods of EM sample preparation: 1) ultrathin sectioning, 2) negative staining,3) freeze etching, 4) surface replica, 5) whole mount or SEM observations. All the samples were examined under JEM-200CX TEM or JSM-35CF SEM.
Ultrastructural study on surface components of Streptococcus suis
Authors: Jacques Mario , Gottschalk Marcelo , Foiry Bernadette , Higgins Robert
Published: June 2020

Streptococcus suis is an important pathogen in pigs. To the best of our knowledge, surface components of S. suis have not been studied. As part of our work dealing with the characterization of S. suis virulence factors, we examined the surface components of nine reference strains. Bacterial capsules are composed of highly hydrated polymers, usually polysaccharides. Because of their chemical properties, they can collapse during dehydration prior to electron microscopy. Jacques and Graham have recently introduced a modified aldehyde fixation process in which addition of a primary amine was found to improve the preservation of bacterial capsule.

Reference strains representing serotypes 1 through 8, and ½ of S. suis were grown on blood agar plates for 18 h at 37°C. Bacteria were harvested and washed once with phosphate buffered saline (PBS, 0.01M, pH 7.2).
Distribution of dihydrofolate reductase-thymidylate synthetase polypeptide in methotrexateresistant and wild type Leishmania major: Evidence for cytoplasmic distribution despite a hydrophilic leader sequence
Authors: Swafford J. R. , Beverley S. M. , Kan C. C. , Caulfield J. P.
Published: June 2020

The housekeeping enzymes, dihydrofolate reductase (DHFR) and thymidylate synthetase (TS) are encoded by separate genes and located in the cytoplasm of higher eukaryotes. However, in the trypanosomatid protozoan Leishmania these enzymes are both located on a single polypeptide. The DNA sequence for this polypeptide predicts a 23 hydrophilic amino acid extension from the amino terminus that resembles the import sequence of mitochondrial proteins in other species. It is not known whether the hydrophilic leader actually occurs in the mature protein in Leishmania since the amino terminus is blocked.

Here, we have examined the distribution of the DHFR-TS peptide in two strains of Leishmania major in order to see if there was a preferential distribution of the protein in the mitochondrion.
The rod-to-coccoid body transformation in cultures of Helicobacter pylori
Authors: Crooker A. R. , Kraft W. G. , Beard T. L. , Myers M. C.
Published: June 2020

Helicobacter pylori is a microaerophilic, gram-negative bacterium found in the upper gastrointestinal tract of humans. There is strong evidence that H. pylori is important in the etiology of gastritis; the bacterium may also be a major predisposing cause of peptic ulceration. On the gastric mucosa, the organism exists as a spiral form with one to seven sheathed flagella at one (usually) or both poles. Short spirals were seen in the first successful culture of the organism in 1983. In 1984, Marshall and Warren reported a coccoid form in older cultures. Since that time, other workers have observed rod and coccal forms in vitro; coccoid forms predominate in cultures 3-7 days old. We sought to examine the growth cycle of H. pylori in prolonged culture and the mode of coccoid body formation.
Electron Microscopic study of the polymyxin treated vibrio cholerae cells
Authors: Kumar Mandal Tapas
Published: June 2020

Infections by Vibrio Cholerae (a gram-negative bacterial organism) in the Indian subcontinent are frequently encoutered. The polypeptide antibiotic polymyxin-B (PB) is a clinically important antibiotic which is used to treat infections caused by a number of gr am-negative bacteria. It has been observed that PB causes disruption of u U1rastructure of outer membrane (OW) , as revealed by the electron microscopic studies for a number of bacteria, through the formation of blebs and crenations (finger-like structures) on the OM . In this context, it is relevant to look specifically at the morphological changes induced by PB on Vibrio cells. PB produces dose dependent changes in the surface topography of pathogenic Vibrio cholerae cells. The susceptibilities of various vibrio strains to PB are also studied through analytical techniques.
Ultrastructural studies on the pheromone gland of Exorista sorbillans (Weidman): A serious pest of silkworms
Authors: Akbar M. , Jamil Kaiser
Published: June 2020

Calling behaviour in several insect species has been related to the volatile chemicals produced and released from specialised glands in the abdominal region of the adult insects. These chemicals comprising generally of about 13-24 carbon straightchain compounds with active cis and trans positions, known as pheromones, are produced from specialised cells located on pheromone gland. in view of the importance of these cellular structures ultrastructural studies were carried out. These glands were found to be located on the ovipositor of the female fly.

The heptane washings of the ovipositors of the female flies induced behavioural response in male flies when bioassayed. Having confirmed the presence of the chemical eliciting behavioural response, it was found important to locate the gland producing these chemicals.
Role of sulfolipds in grana thylakoid stacking
Authors: Coats Lorenzo W.
Published: June 2020

In higher plants and algae, the thylakoid membranes are organized into closely appressed or stacked regions (grana), and a network of single interconnecting unstacked regions (stroma lamellae). The components and forces responsible for adhesion between thylakoids have been the subject of intense studies. Although these studies have added significantly to our knowledge of chloroplast membrane structure and function, they have failed to provide a clear rationale for grana membrane stacking. Completedestacking of grana occurs when chloroplasts are suspended in low-salt (10 mM NaCl) solution. Normal levels of stacked and un-stacked regions can be restored by incubation in salt solutions (150 mM NaCl).
Freeze-substitution of rye grass and ragweed pollen grains
Authors: Martinez Liza B. , Wick Susan M.
Published: June 2020

Rapid freezing and freeze-substitution have been employed as alternatives to chemical fixation because of the improved structural preservation obtained in various cell types. This has been attributed to biomolecular immobilization derived from the extremely rapid arrest of cell function. These methods allow the elimination of conventionally used fixatives, which may have denaturing or “masking” effects on proteins. Thus, this makes them ideal techniques for immunocytochemistry, in which preservation of both ultrastructure and antigenicity are important. These procedures are also compatible with cold embedding acrylic resins which are known to increase sensitivity in immunolabelling.

This study reveals how rapid freezing and freeze-substitution may prove to be useful in the study of the mobile allergenic proteins of rye grass and ragweed. Most studies have relied on the use of osmium tetroxide to achieve the necessary ultrastructural detail in pollen whereas those that omitted it have had to contend with poor overall preservation.