Profiles Of Rough Endoplasmic Reticulum Research Articles

Development and ultrastructure of cells of the sex pheromone gland in the white-marked tussock moth, Orgyia leucostigma (J. E. Smith) (Lepidoptera: Lymantriidae)

In pharate adults of female Orgyia leucostigma the pheromone gland cells are columnar. They change to goblet-shaped cells during the day preceding emergence. Concurrently, endocuticular extensions follow the contour of the neck of each goblet cell. Until 12–24 hr following emergence of the adult female, gland cell cytoplasm contains short profiles of rough endoplasmic reticulum and free ribosomes. In cells from 1-, 2- and 3-day-old virgin and 1-day-old mated females extensive well-organized smooth cisternal and rough endoplasmic reticulum predominate. Arrays of membranes, forming unusual organelles are located near the nuclei. They are associated with the Golgi complexes, rough endoplasmic reticulum and microbodies. Microvilli are variable in length and sometimes absent. Cuticular ultrastructure is the same as that of the pharate adult, and is not affected by surface extraction with hexane.

Characterization of the mononuclear cell infiltrate in human malignant melanoma.

In the skin infiltrate of superficial spreading melanoma, non phagocytosing mononuclear cells (NPMC) represent a major cell component. The number of NPMCs decreases as a function of tumour progression. In addition, when an NPMC is in contact with a malignant melanocyte, the latter cell exhibits ultrastructural degenerative changes. In the blood of healthy donors and of melanoma patients, atypical mononuclear cells (AMC) can be identified. AMCs have been shown to participate in antibody-dependent cellular cytotoxicity (ADCC) reactions against melanoma cells in vitro. In this paper, it is reported that NPMCs and AMCs have in common their size, and some ultrastructural features such as indented nuclei, dispersed organelles, rough endoplasmic reticulum profiles and surface microvilli. The two cell types are negative for non-specific esterase. They also fail to react for peroxidase at either the light or the electron microscopic level. They do not adhere to glass. AMCs do not form spontaneous E rosettes, they have no surface IgG and they have no receptors for complement. However, they do form rosettes with EAIgG. On frozen sections firm binding of EAIgG has been seen on the skin infiltrate in three cases out of 10. It is concluded that NPMCs might react with tumour cells in vivo, in the same manner as do AMCs in vitro.

Ultrastructure of Auxin-Induced Tumors of the Coleorhiza-Epiblast of Wheat

When wheat is germinated in high concentrations of certain auxins, the coleorhiza-epiblast grows in an excessive and disorganized manner and resembles a callus. Wheat was germinated in 10/sup -3/ M indoleacetic acid or in water. There was greater net synthesis of DNA, RNA, and protein in the tumor tissue than in control tissue. Control and tumor tissue was fixed for electron microscopy 1, 2, 3, and 4 days after sowing. In contrast to the controls, many more lipoidal bodies appeared in 1-day-old, auxin-treated tissue and thereafter diminished in number. In 2- and 3-day-old tumor tissue, small membraneous fragments were prominent but disappeared in older tissue. With time, the following changes became progressively more pronounced: cytoplasmic vacuolation, appearance of myelin figures, polyribosome configurations and extensive profiles of rough endoplasmic reticulum, and sloughing of cytoplasmic contents into and accumulation of electron-dense material in vacuoles. Possible factors in susceptibility of certain tissues to tumor formation are discussed.

ULTRASTRUCTURE OF AUXIN-INDUCED TUMORS OF THE COLEORHIZA-EPIBLAST OF WHEAT.

When wheat is germinated in high concentrations of certain auxins, the coleorhiza-epiblast grows in an excessive and disorganized manner and resembles a callus. Wheat was germinated in 10-3 M indoleacetic acid or in water. There was greater net synthesis of DNA, RNA, and protein in the tumor tissue than in control tissue. Control and tumor tissue was fixed for electron microscopy 1, 2, 3, and 4 days after sowing. In contrast to the controls, many more lipoidal bodies appeared in 1-day-old, auxin-treated tissue and thereafter diminished in number. In 2- and 3-day-old tumor tissue, small membraneous fragments were prominent but disappeared in older tissue. With time, the following changes became progressively more pronounced: cytoplasmic vacuolation, appearance of myelin figures, polyribosome configurations and extensive profiles of rough endoplasmic reticulum, and sloughing of cytoplasmic contents into and accumulation of electron-dense material in vacuoles. Possible factors in susceptibility of certain tissues to tumor formation are discussed.

Skin Vascular Ultrastructure During Thermal Injury, Hypertrophic Scarring and its Resolution

The usual result of deep thermal injury of the skin in children is hypertrophic scarring. The dynamics of revascularization have been implicated as integral to development and resolution of hypertrophic scarring. Thus, special attention is being directed toward examining vessels at different stages after injury.In vessels from normal skin endothelial cells do not contain many organelles; Golgi membranes are sometimes observed, a few mitochondria and occasional profiles of rough endoplasmic reticulum. Pinocytic vesicles are present on both tissue and blood side of the endothelial cells and in the perivascular satellite cells. Infrequently multivesicular bodies are observed. A thin basement membrane underlies endothelial cells and their satellites (Fig. 1).In the post-injury granulation tissue pinocytic vesicles and multivesicular bodies are seldom seen. The endothelial cells contain a marked increase in rough endoplasmic reticulum, often dilated, and intracytoplasmic filaments (Fig. 2).

Fine Structure of the Neuron Perinuclear Ring of Boophilus microplus1

The use of pyronine-malachite green (PMaG) for staining the RNA in invertebrate central nervous systems (Baker and Williams 1965) made it possible to use the perinuclear RNA ring as a marker in identifying the individual central nerve cell body with respect to its peripheral axon cut (Cohen and Jacklet 1965, Chow et al. 1973). Although many attempts were made to see the ultrastructural features that correspond to this RNA ring in insects observed histochemically with the light microscope (Young et al. 1970, Byers 1970), no data were reported in ticks. By using the tropical cattle tick, Boophilus microplus (Canestrini), as experimental material, I find that the RNA ring around the nucleus of the motor neurons in the tick synganglion consists of multiple profiles of rough endoplasmic reticulum and mitochondria intermingled between them.

A morphological and histochemical study of sertoli cells in normal and XX sex‐reversed mice

AbstractMorphological and histochemical studies on the testes of mice with XX sex‐reversal demonstrates several profound differences in the ultracytology and oxidative enzyme activity of Sertoli cells as compared to the normal. Membranous structures, cytoplasmic inclusions, and certain dehydrogenases in Sertoli cells of normal mice are described in relation to a possible role in steroid synthesis. In XX sex‐reversed mice, two types of Sertoli cells are observed in the seminiferous tubules which are devoid of germ cells. One type is the randomly dispersed cells, which reveal the following ultrastructural alterations when compared with the normal cells: large spherical nuclei with prominent nucleoli, reduced smooth endoplasmic reticulum, pleomorphic mitochondria with no apparent cristae, and decreased lipid droplets. The other type is clustered cells which appear similar to immature Sertoli cells. These cells have small nuclei with poorly developed nucleoli, small profiles of rough endoplasmic reticulum, pleomorphic mitochondria, decreased lipid droplets, and an absence of specialized inter‐Sertoli cell junctions.The results of this study suggest that functional and ultrastructural alterations of Sertoli cells in XX sex‐reversed mice may result from degeneration or absence of germinal cells, and that steroidogenesis by Sertoli cells in mice may be associated with the development of germinal cells. It is also suggested that Sertoli cells may secrete a steroid which controls follicle‐stimulating hormone secretion.

Morphology of the reproductive system of the armadillo. The spermatogonia.

AbstractSpermatogonia of the nine‐banded armadillo, Dasypus novemcinctus mexicanus, were studied morphologically using light and electron microscopy and examined histochemically using light microscopy. Immature flat type spermatogonia have ovoid or irregular nuclei with loosely condensed chromatin. Free ribosomes are abundant while profiles of rough endoplasmic reticulum are scarce. Smooth endoplasmic reticulum is a prominent feature occasionally taking an unusual cylindrical form. Mature spermatogonia exhibit rounder nuclei with greater degrees of chromatin clumping. Smooth endoplasmic reticulum is no longer prominent whereas profiles of rough endoplasmic reticulum are quite common. Occasional lysosomal configurations are found in mature spermatogonia.The majority of spermatogonial cells exhibit weak to moderate reactivity when stained with the periodic acid‐Schiff (PAS) reaction. Certain cells in each tubular cross section stain vividly with this reaction and the PAS positivity is removable with salivary amylase. Because of nuclear characteristics, position of the cell immediately upon the basal lamina, intensity of the PAS reaction and the relative paucity of the vividly staining cells, it is suggested that they are members of the immature spermatogonial cell line, perhaps acting as stem cells. None of the several other histochemical procedures employed was capable of selectively demonstrating these cells.

An analysis of urodelian retinal regeneration. II. Ultrastructural features of retinal regeneration in Notophthalmus viridescens.

AbstractThe process of retinal regeneration in the posterior pole of enucleated and reimplanted eyes of adult Notophthalmus viridescens was studied with the electron microscope. The posterior pigment epithelium displayed two distinct cellular types which served either as phagocytic cells or for repopulating the retina. The phagocytic cells, which displayed a marginal nuclear chromatin, numerous mitochondria and profiles of rough endoplasmic reticulum, served to remove degenerating retinal and lens debris. The cells destined to repopulate the retina appeared to pass through an indifferent phase in which both single melanin granules and sequestered areas of pigmented cytoplasm were extruded. These cells displayed a markedly heterochromatic nucleus surrounded by a cytoplasm with scattered free ribosomes, short profiles of endoplasmic reticulum, and small rounded mitochondria. Once the retinal regenerate has been formed, the pigment epithelium was restored upon Bruch's membrane and the cells displayed melanin formation and an extensive smooth endoplasmic reticulum. The development of the full melanin complement, with apical cytoplasmic fringes and rough endoplasmic reticulum, depended upon differentiation of the new retina.By day 25, the newly reconstituted retina began to display vertical alignment of cells and differentiation of the inner layers. Each of the photoreceptors passed through an indifferent phase in which all cells showed a similar mitochondrial ellipsoid and small glycogen paraboloid. Rods, due to their increase in size, and double cones, due to the encapsulation of the principal element within the accessory element, were the first photoreceptors to become recognizable. The initial formation of the outer plexiform layer resulted from an outgrowth of horizontal cell processes coincident with a wave of local cellular degeneration. Synaptic bases of the photoreceptors developed fully after invagination by the principal bipolar and horizontal processes.The significance of the cellular patterns observed during retinal restitution and differentiation, with respect to the origin of the double cone and the formation of rods and cones, and the nature of the pigment epithelial cells and their response to local degeneration of the retina, is discussed.

The fine structure of the monkey (Macaca) Sertoli cell and its role in maintaining the blood-testis barrier.

AbstractThe monkey Sertoli cell, a tall columnar cell, extends from the basement membrane of the seminiferous epithelium to the tubule lumen. Its nucleus occupies a basal position and reveals extensive nuclear envelope infoldings. A zone of fine filaments, approximately 0.5 μ in thickness, invests the nucleus and appears to prevent other cell organelles from approaching it. The basal cytoplasm is characterized by numerous mitochondria and abundant smooth endoplasmic reticulum. Lipid droplets, 3 to 4 μ in diameter, membrane‐limited dense bodies of various shapes and densities, Golgi cisternae, scattered free ribosomes and parallel profiles of rough endoplasmic reticulum are common. The more apical portions of the cell contain longitudinally oriented microtubules and rod‐shaped mitochondria, but other organelles are rare.The seminiferous tubules of monkeys are surrounded by three to five circumferentially arranged cells that overlap each other but are separated by intercellular spaces of at least 300 to 400 Å. Tracers such as horseradish peroxidase and lanthanum nitrate injected intravascularly readily pass between the peritubular cells and enter the germinal epithelium. Within the epithelium the tracers outline the spermatogonia and early spermatocytes by permeating the surrounding intercellular spaces. Further penetration toward the tubule lumen is effectively prevented by the occluding tight junctions joining adjacent Sertoli cells. Thus, in monkeys the peritubular epithelioid cells do not impede vascularly introduced tracers from penetrating into the germinal epithelium. The only morphological component of the blood‐testis barrier in the macaque appears to be the Sertoli‐Sertoli occluding junction.

Reversibility of ultrastructural freeze-thaw-induced injury: demonstration in the endothelium of cryopreserved corneal tissue.

Structural damage was present in the endothelium of cryopreserved rabbit corneas after thawing, even though the corneas had been frozen as soon as possible after killing the animal. This damage included clarification of the cytoplasm, condensation of the mitochondria accompanied by swelling of the cristae, dilatation of the perinuclear spaces and profiles of rough endoplasmic reticulum, and interruptions in the continuity of cellular membranes. All of these changes, however, were shown to be reversible during rehydration of the frozenthawed tissue in Kinsey medium, in albumin and saline, or in vivo in the aqueous humor of a recipient rabbit eye prepared for penetrating keratoplasty.

Estriol levels of cord blood, maternal venous blood, and amniotic fluid at delivery at high altitude

hypoplastic Fallopian tubes and a rudimentary bicorn uterus. One gonad was removed. Microscopic examination of the gonad revealed testicular tissue composed of seminiferous tubules and numerous Leydig cells encircling them (Fig. 1) . Ultrastructurally the seminiferous tubules were lined by Sertoli cells and occasional germ c,ells. Leydig cells were adherent to the outer side of the basement membrane (Fig. 2). Besides topographic distinction these cells could be distinguished on the basis of their cytoplasmic appearance. The cytoplasm of Leydig cells was ultrastructurally most differentiated. It was replete with small vesicles of smooth endoplasmic reticulum, indicating the endocrine origin of this b cell type. In contrast to adult Leydig cells, the vesicles of endoplasmic reticulum were very small and showed no cistemal dilatations. There were also very few mitochondria and profiles of rough endoplasmic reticulum, Only occasionally were there lipid droplets of irregular sire and shape and no dense bodies (so characteristic for the adult Leydig cells) were seen. Although the interstitial cells in the testis of this patient had the basic appearance of steroid hormone-producing cells, they were quite distinct from adult, active Leydig cells. Ultrastructurally we could thus concur with the view of Teter and Boczkowskir that the low output of androgenic hormones in some patients with testicular feminization is due to immaturity of Leydig cells.

The fine structure of sow lutein cells.

AbstractThe morphological observations described in this report are part of a biochemical study of progesterone intermediates using sow ovary. This tissue is extensively involved in the production of some steroid hormones. Because the lutein cells are thought to be involved in the synthesis of progesterone and its intermediates and because these cells constitute by size and number the greatest portion of the mass of sow ovary, we confined the morphological investigation to these cells. Sow corpora lutea, fixed with glutaraldehyde and osmium tetroxide were examined by light and electron microscopy.The lutein cells of the sow are large epithelioid cells with oval nuclei and extensive amounts of cytoplasm. Large masses of highly organized smooth endoplasmic reticulum, many oval mitochondria with tubular cristae, and many lipid droplets are present. Only a few profiles of rough endoplasmic reticulum are seen in any one section, and Golgi membranes cannot by distinguished from other smooth membranes. The smooth endoplasmic reticulum is the major membranous organelle in these luteal cells. Microsomal preparations from luteal cells must be very rich in fragments of these smooth membranes. The demonstration of many steroidogenic enzyme systems in microsomal preparations lends strong support to the supposition that these enzyme systems reside in the smooth endoplasmic reticulum.