Dilated Cisternae Of Endoplasmic Reticulum Research Articles

Ethylene effects on peroxidases and cell growth patterns in Picea abies hypocotyl cuttings

The effect of 2‐chloroethylphosphonic acid (ethrel) on cell growth patterns and per‐oxidase activity (EC 1.11.1.7) and location in young Norway spruce cuttings (Picea abies [L.] Karst.) was investigated. The peroxidase activity in a fraction containing soluble and membrane bound enzymes show a diurnal variation, with decreased activity during the light period and a corresponding increase during the following dark period. The decrease during the day could to some extent be counteracted by treatment with ethrel. It appears that ethrel affects only peroxidases in the isolated membrane fraction, since peroxidases bound to the cell wall were not affected by ethrel. In vitro experiments indicated that the hydrophobicity of soluble peroxidases was increased by treatment with ethylene. Cytochemical localization of peroxidase activity in differentiating tracheids revealed a clear ethrel‐induced increase in the tonoplast. It appears that ethylene affects soluble peroxidases in vivo in such a way that they are directed to a more hydrophobic environment, like the tonoplast. Treatment with ethrel also changed the appearance of the rough endoplasmic reticulum (ER) and Golgi apparatus. Dilated ER cisternae were observed on electron micrographs, as a result of treatment with ethrel. The number of vesicles produced by the Golgi apparatus and also the amount of vesicles fusing with the plasma membrane in secondary‐wall‐forming tracheids increased considerably. The results clearly indicate that the stimulatory effect of ethylene in spruce seedlings on lignification and cell wall formation, is due to a general stimulation on both synthesis, transport and secretion of cell wall material and not on a stimulation of peroxidase activity as reported for other species.

Ole e I: epitope mapping, cross-reactivity with other Oleaceae pollens and ultrastructural localization.

Ole e I is the major allergen derived from olive tree pollen (Olea europaea) and it is composed of two polypeptides with molecular weights (MWs) of 18 and 20 kD. A panel of six monoclonal antibodies (mAbs) has been prepared and used to map antigenic determinants on this molecule. Four epitope determinants have been identified on Ole e I. Using the purified mAbs produced against Ole e I, we have analyzed the common epitope determinants in olive (O. europaea) and different Oleaceae pollens: ash (Fraxinus excelsior); privet (Ligustrum vulgare); lilac (Syringa vulgaris), and forsythia (Forsythia suspensa). ELISA showed three reactivity groups depending on the recognition of monoclonal antibodies: (1) olive and ash; (2) olive, ash, privet and lilac; and (3) olive, ash, privet, lilac and forsythia. Immunoblotting studies on Oleaceae pollen extracts with these mAbs showed a very similar cross-reactivity pattern. The 18- and 20-kD MW proteins were present in each pollen, except in the case of forsythia. In this case the reactivity pattern was associated with 50- to 55-kD protein bands. This band was recognized by a pool of sera from olive-allergic patients. Finally, ultrastructural localization of Ole e I antigen was performed on the mature olive pollen grain. Ole e I was located in association with dilated endoplasmic reticulum cisternae. Pollen grain walls, nuclei and cytoplasmic organelles were totally devoid of the allergen.

Clear cell chondrosarcoma: case report and ultrastructural study

A case of clear cell chondrosarcoma in a Chinese patient is described. The clear cells showed strongly positive S-100 protein immunoreactivity. Ultrastructurally 2 types of chondroid cells were demonstrated. One type appeared more primitive with abundant electron-lucent cytoplasm and sparse organelles. The other type of cell was more differentiated with presence of microvilli and numerous dilated cisternae of endoplasmic reticulum. Previous ultrastructural studies on these lesions were reviewed and compared with the present findings.

Clear-cell chondrosarcoma: a case report

Clear-cell chondrosarcoma, a recently specified entity, is a low-grade malignant tumor and has characteristic clinical, roentgenographic and pathologic findings which separate it from conventional chondrosarcoma and other benign tumors. Therefore, correct diagnosis is important from the viewpoint of both prognosis and therapeutic approach. We report a case of typical recurrent clear-cell chordirosarcoma. Typical round cells with clear cytoplasm, large nuclei, and small nucleoli were wellnoted. The clear cytoplasm was faintly positive in PAS staining. Electronmicroscopic study showed that these cells were of chondroid origin, showing indented nuclei, large dilated endoplasmic reticulum cisternae, bundles of actin-like filaments and a few glycogen particles.

Retrovirus‐like particles in hepatocytes of patients with transfusion‐acquired Non‐A, Non‐B hepatitis

Retrovirus-like particles 60-85 nm in diameter were observed in the cytoplasm of hepatocytes in liver biopsies obtained during the acute and chronic phases of non-A, non-B hepatitis (NANBH) in three patients with transfusion-acquired disease. The particles appeared in dilated endoplasmic reticulum cisternae as well as in enlarged Golgi vesicles. No such particles were seen in hepatocytes in liver biopsies similarly obtained during the acute or chronic phases of NANBH from 11 additional patients with NANBH who did not acquire their disease following blood transfusion. Particle-associated reverse transcriptase activity (peak activity at a density of 1.14 gm/ml) was present in the sera of all three "particle-positive" patients and also in 42% of the "particle-negative" patients. The retrovirus-like particles described here were apparently unrelated to the previously described human T cell lymphocytotropic retroviruses (HTLV), since none of the 14 patients studied had antibodies in their serum directed against antigens of any of the three known HTLVs.

Glucagon control of carcinogenesis.

Long term administration of glucagon markedly enhanced carcinoma formation in mice simultaneously treated with a chemical carcinogen, 3-methylcholanthrene (3-MCA). The number and size of squamous cell carcinomas were 3-fold greater compared to those in mice treated with MCA alone. DNA labeling and the percentage of [3H]thymidine-labeled cells were also 2- to 3-fold higher in glucagon- and MCA-treated mice than in those treated with MCA only or 5- to 6-fold higher than those in control mice. Ultrastructural studies of glucagon- and MCA-treated tumors revealed the predominance of acinar-cystoid and secretory types of tumors, with the occurrence of large and dense secretory granules (Zymogen-like granules), markedly dilated endoplasmic reticulum cisternae, and lysosomes compared to only typical squamous neoplastic cells observed in MCA-treated mice. Scanning electron microscopic observations also indicated that neoplastic cells of MCA and glucagon-treated tumors exhibited characteristic secretory features on their cell surfaces (a marked increase in blebs and microvilli). These findings demonstrate that glucagon in pharmacological doses significantly enhanced the carcinogenic process and changed the cytodifferentiation of neoplastic cells and, thus, plays an important role in controlling tumor cell biology and neoplastic transformation.

Vibrator ( vb): a spinocerebellar system degeneration with autosomal recessive inheritance in mice

Vibrator (gene symbol vb), an autosomal recessive mutation, occurred spontaneously in the DBA/2J strain of mice, was rescued by a single cross to C57BL/6J and subsequent brother × sister mating, and has been mapped near shaker-2 ( sh-2) and vestigial tail ( vt) on chromosome 11. The name emphasizes the unusually rapid (18–20 Hz) postural action tremor expressed in juvenile homozygotes. Selected neurons in spinal cord, and later in brainstem and cerebellum, show progressive degenerative changes featuring dilated cisternae of endoplasmic reticulum in cell bodies, dendrites and axons, with eventual severe intracellular vacuolation and some cell death.

Graniferous tracheary elements in the haustorium ofAtkinsonia ligustrina, a root hemi-parasite of theLoranthaceae

The xylem conducting cells that form the vascular core in the root haustorium ofAtkinsonia ligustrina are shown to be graniferous tracheary elements. Their luminal contents occur in the form of granules, amorphous bodies or finely dispersed material derived from the granules. Cells of this type are known for theSantalaceae, but have not previously been reported unequivocally in theLoranthaceae. The matrix of the granules consists of compacted fibrillar material often with the central region of the granule showing a crystalline substructure. The granules stain positively for protein. In some instances the matrix may become secondarily impregnated with phenolic compounds. The granules arise during differentiation of the tracheary element and develop as accumulations of matrix within dilated cisternae of endoplasmic reticulum. The function of graniferous tracheary elements inAtkinsonia may be to help regulate the flow of xylem sap from host to parasite, as has been suggested for theSantalaceae.

Freeze-fracture study of rat ventral prostate: secretory mechanisms in the epithelial cell.

Membrane events during apocrine and merocrine secretion of rat ventral prostate epithelial cells were analyzed by freeze-fracture. Early morphological manifestation of both secretory modes involves focal clearance of microvilli characterized by their progressive inclination and attenuation over the apical membrane. Merocrine secretion includes invasion of the apical microfilament web by the secretory vesicle and clearance of membrane particles at the site of its interaction with the apical plasmalemma. During apocrine secretion, a portion of the plasma membrane cleared of microvilli projects into the lumen. Growth of this projection is accompanied by a progressive, but partial, clearing of membrane particles and results in the formation of a large bleb containing dilated endoplasmic reticulum cisternae. Completion of the process involves "degeneration" of the bleb and its release by constriction of a neck, and possibly, fusion of vesicular or tubular structures. Swelling and blebbing of microvilli are shown to be preparation artifacts.

Growth and differentiation of secondary malpighian tubules in the cockroach, Periplaneta americana.

Four differentiated Malpighian tubules (primary tubules) extend from the junction of the midgut and hindgut in newly hatched Periplaneta americana. Secondary tubules begin to develop near the base of the primary tubules before hatching and successive nymphal molts. The newly initiated tubules undergo cell division and extensive elongation through the middle of the following intermolt period. During this time, the cells of the distal, middle, and lower middle tubule regions are surrounded by a cellular sheath, have few cytoplasmic processes extending along their basal surfaces, have a small or nonexistent lumen, and contain extremely dilated cisternae of endoplasmic reticulum. The cellular sheath differentiates into the muscle which coils around the mature tubule. Tubules which begin development toward the end of one intermolt period begin to undergo cytodifferentiation toward the end of the next intermolt period. By the middle of an additional intermolt period, the basal infoldings and microvilli of cells in the distal, middle, and lower middle regions have the conformations typical for those regions in differentiated tubules; granular concretions and stellate cells are present within the middle region of the tubule.

Postmortem changes and viability of retinal vessels after cold storage. A differential susceptibility of endothelial cells and pericytes

Postmortem changes occurring in the retinal vascular complex of cadaver rabbits which had been stored in a domestic refrigerator at +4°C for up to three weeks, were sequentially analysed by light and electron microscopy. Five stages in the degradation of the cells are identified with stage 1 representing the normal in vivo situation of subcellular morphology. Stage 2 shows dilated cisternae of endoplasmic reticulum, blebs and irregularities in the plasma membranes, and early margination of nuclear chromatin. Stage 3 is characterized by further changes such as mitochondrial pyknosis, early nuclear pyknosis and cytoplasmic hydrolysis. Stage 4, in addition to the preceding alterations, shows variable mitochondrial swelling and marked clumping of nuclear chromatin. In stage 5 there is generalized and marked mitochondrial swelling with membrane dissolution, advanced cytoplasmic hydrolysis, disappearance of lysosomes and polysomes, formation of membranous bodies, nuclear karyolysis and breaks and interruptions in the limiting cell membrane. To evaluate the viability of the cells, one half of the retinal vascular complexes from the same eye, as above, was incubated in a tissue culture environment. A correlation of results revealed that the morphological changes in the initial explant designated as stages 2 and 3 would seem to be compatible with reversibility of the cellular changes and hence cell survival. Although it was difficult to define precisely the moment of cell death, no growth would be expected once the alterations had progressed to stages 4 and 5 and hence are considered as consistent with irreversible cell damage or necrosis. The vulnerability of the pericytes, in comparison to the endothelial cells, to postmortem damage and ischaemia, is described and discussed. It is suggested that potentially useful diseased tissue should not be discarded altogether on the grounds of postmortem change, for at times it can reveal information of crucial diagnostic significance provided one is aware of the possible artefacts.

Tubuloreticular structures in rubella virus-infected human fetuses

Tubuloreticular structures (TRS) consisting of branching tubules of variable length and with a diameter of 18-30 nm have been described within dilated endoplasmic reticulum cisternae of endothelial and other cells in a variety of conditions. Thus, TRS have been observed in apparently normal human and animal cells, in cells of patients with auto-immune disease (e. g. systemic lupus erythematodes), with neoplasia (leukemias, carcinomas, sarcomas) as well as with a number of viral infections caused by both DNA or RNA viruses. Whereas earlier investigators regarded TRS as viral or virus-like in nature, it is now widely accepted that these structures represent focal proliferations of ER-membranes and that they reflect a cellular response to a broad range of stimuli. The biological significance of TRS has, however, not been resolved.In rubella-infected human embryos and fetuses, vascular lesions are the most frequently observed light microscopical findings.

Ultrastructural hepatic changes in rats after oral administration of ethoxyquin (EMQ)

A single oral administration (500 mg/kg b.w.) of the antioxidant ethoxyquin (EMQ), was found to result in ultrastructural changes in liver cells, expressed by proliferation of smooth endoplasmic reticulum, dilated cisternae of endoplasmic reticulum, disorganization of mitochondrial membranes and desquamation of lining cells.

TUBULES IN DILATED CISTERNAE OF ENDOPLASMIC RETICULUM OF THLASPI ARVENSE (CRUCIFERAE)

Tubular inclusions in dilated cisternae of endoplasmic reticulum (ER) were found in healthy and virus diseased pennycress (Thlaspi arvense L., Cruciferae). The dilated cisternae were encountered more often in virus‐infected cells than in comparable cells from healthy control plants. Dilated ER cisternae were found in vascular parenchyma cells and were shown to be interconnected. The tubules measured 30 nm in diam and cisternae that contain them may be more than 10 μm in length.

Ultrastructure of Trypanosoma lewisi, localization and alterations in rat liver.

Fine structure of Trypanosoma lewisi in rat liver has been studied by electron microscopy 14 days after infection. Various sections examined showed the parasites to be located in liver’s sinusoids or space of Disse.Electron micrographs demonstrate that the contact between the flagellum and the pellicle at the attachment zone is maintained through a desmosome-like substance, while a peculiar section illustrates a fusion of two cells which tangentially depict lattice-like surface and cross-striation of flagellar bundle.Parasites found in sinusoids showed double-membranes, double coiled, DNA-rich kinetoplast with cristae present in basal portion and a prokinetosome parallel in position to the kinetosomal plate which is completely separated from the kinetosome that fastens the flagellum to it like a zipping hook. The positions of these flagellar organelles to the kinetoplast indicate that the kinetosome replication is initiated beyond the kinetoplast division. It is not certain whether the four vacuole-like tubules located in the cytoplasm parallel to kinetosome complex are functionally related to impulse coordination. However, they appear to be involved in pinocytotic activity.Striking features of the parasite in the sinusoid and space of Disse include dense cytoplasmic granules, free ribosomes, nucleus with double membranes and nuclear pores, variable size vacuoles, dense bodies, and rough surface endoplasmic reticulum stretching from the anterior region and bypassing the golgi area all the way to the posterior end of the kinetoplast. The existence of a continuous highly organised relationship between the external nuclear membrane, endoplasmic reticulum and other cytoplasmic contents is demonstrated in the micrographs of the ’ liver parasites The complexity observed and reported here is further documented by (a ) that external mitochondrial membrane is shown to be in contact with sub-pellicular microtubules, (b ) unity and continuity of the mitochondria with an agranular secretory reticulum exist, and (c ) that the elongated mitochondrial extension from the kinetoplast deep into the cytoplasm confirms a previous report that it originates from the kinetoplast. The presence of abundant free ribosomes in the parasite convincingly indicates that the organism is progressively synthesizing more protein when trapped in the tissue.The investigation also demonstrates that when Trypanosoma lewisi where found enclosed in hepatic sinusoid and space of Disse, pathological alterations in the parasite occurred. Inflammation of flagellum at the base and the entire cytoplasmic content of the mid-posterior portion of the organism also occurred.Liver cells parasitized by the trypanosomes showed dilated cisternae of endoplasmic reticulum, swollen mitochondria, fatty infiltrations, dense bodies, vacuoles of different sizes and numerous clusters of ferritin granules. The parasite increased rhythmic activity of locommotion might have enhanced these alterations. Hydrolytic effect of numerous lysosomes of the liver cells might have accelerated the alterations. On the other hand the accumulation of excessive metabolic products of the parasites themselves could also have exerted alterable effect on the liver cells and the sinusoids. Lysosomes or microbodies found in the various liver trypanosomes were possibly spontaneously released by rupture due to injured or dying cells.

Ultramorphological features of an experimental hamster sarcoma.

Cells from an experimental sarcoma produced by inoculation of BHK 21 cells clone 13 cells in hamsters showed many similar ultrastructural features with the original cultured cells. Clear and dark cells, probably representing different metabolic stages of the same tumor cell, were noted. In both tumor and culture cells, type R or H virus-like particles could be detected. The high number of R or H particles observed in tumor cells suggests their participation in the oncogenesis of this neoplasm. The tumor cells contained several dilated endoplasmic reticulum cisternae with round and filamentous R type virus particles. Many tumor cells presented nuclear bodies of the filamentous and granular types.

Ultrastructure of neurons in the arcuate nucleus of the rat.

AbstractIn the arcuate nucleus of the normal rat there are two types of neurons. One of them is characterized by a dense cytoplasmic matrix, dilated endoplasmic reticulum cisternae and well developed Golgi complexes; the other cell type by a paler overall appearance. In both of them granulated vesicles of about 1000 Å in diameter with a core of variable density are present. The frequent association between these vesicles and the Golgi complex suggests that they are formed in relation to this organoid. The presence of lysosomes and multivesicular bodies and their close relationship with granulated vesicles is analyzed.The neuropil of the nucleus is constituted by axons, dendrites and glial processes. The majority of the axon profiles and nerve endings contain a mixed population of clear and granulated vesicles, the latter having a diameter ranging between 600 to 1300 Å.The finding of granulated vesicles in arcuate neurons is discussed in relation with the known monoamine content of them and the dopaminergic nature of the fibers that form the tuberoinfundibular tract. It is suggested that these granulated vesicles contain primary monoamines.