Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Ultrastructure”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54Linked to original sources
PubMed2005

Selective induction of ultrastructural (neurofilament) compaction in axons by means of a new head-injury apparatus.

A new weight-drop head-injury apparatus is described that can produce a momentary depression of predetermined depth at a predetermined site of the elastic calvaria of scalped young adult rats. In Wistar rats weighing about 200 g, a 0.75-mm deep calvaria depression immediately caused ultrastructural (neurofilament) compaction in many long axon segments, which were diffusely scattered among non-compacted axons in a well-defined area of cortical layers IV and V under the impact site. Apart from these morphological changes and swollen astrocytic processes in their vicinity, the brain tissue appeared non-impaired. The blood pressure, intracranial pressure, heart rate and respiration rate had returned to the normal range in 1 min. Diffuse axonal swelling caused by impaired axonal transport, ultrastructural compaction in neuronal soma-dendrite domains, impression fracture and subarachnoid or subdural hemorrhages were observed only in rats with a calvaria depression of 1mm or more. All these features create favorable circumstances for study of various problems that are closely related to the ultrastructural (neurofilament) compaction in axons, such as the fate of the affected axons.

Amyloid beta-Protein Precursor↗
PubMed2005

Histologic and ultrastructural study on statin graft in rabbit skulls.

PURPOSE: To study the early healing pattern of statin-induced osteogenesis, we examined the early histologic and ultrastructural pictures of bone defect healing with and without statin. MATERIALS AND METHODS: Twenty-eight bone defects were created in the parietal bone of 14 New Zealand White rabbits. In the Statin Group of 7 rabbits, the defects were grafted with collagen matrix carriers mixed with statin solution. In the Collagen Matrix Group of 7 rabbits, the defects were grafted with collagen matrix carriers mixed with water for injection. The Statin Group and the Collagen Matrix Group were killed on day 1, 2, 3, 4, 5, 6, or 14 after surgery. Bone defects with surrounding tissues were prepared for histologic assessment. Bone defects of day 14 were also prepared for ultrastructural assessment. RESULTS: New bone was formed on day 5 in the defects grafted with statin. No cartilage intermediate stage was detected. This occurred 1 day earlier than for those grafted with the carrier alone. The bone defects of day 14 showed that an abundance of bone was formed in the Statin Group and osteocytes were identified ultrastructurally. CONCLUSIONS: This study supported statin-induced and accelerated bone formation locally.

Animals↗
PubMed2004

Ultrastructural changes during in situ early postmortem autolysis in kidney, pancreas, liver, heart and skeletal muscle of rats.

Many morphological studies of the postmortem interval were carried out under conditions in which the tissue was incubated in vitro after extirpation. However, the extirpation affects cell viability. We examined the ultrastructural changes in the kidney, pancreas, liver, heart and skeletal muscle of male Wistar rats occurring postmortem in situ. In each organ, cell edema (cell swelling), appearance of amorphous dense deposits in the mitochondria, loss of glycogen granules, dilation of the endoplasmic reticulum, clumping and margination of nuclear chromatin, and/or condensation of nuclear chromatin were observed, but the duration of the period of ultrastructural change was organ specific. Most of the ultrastructural changes occurred earlier in kidney. In hepatocytes, the morphological degeneration occurred later than in the renal tubule epithelium and earlier than that in the myocardium. Of the five organs we examined, skeletal muscle showed the greatest delay in postmortem change. In the distal tubule epithelium and pancreatic acinar cells, two forms of nuclear change were seen: one resembled necrotic change and the other resembled apoptotic change. The effect of lysosomes and hydrolytic enzymes was not as great as previous findings.

Animals↗
PubMed2006

Ultrastructural and molecular phylogenetic delineation of a new order, the Rhizophydiales (Chytridiomycota).

In the order Chytridiales, Rhizophydium is a morphologically defined genus based upon the production of a monocentric, inoperculate, epibiotic sporangium, an endobiotic rhizoidal axis which branches, and an epibiotic resting spore. Despite its simple morphology, over 220 species of Rhizophydium have been described. Recent phylogenetic analyses using nuLSU rRNA (28 S rRNA) gene sequences of a geographically diverse sampling of Rhizophydium cultures revealed that the classical genus Rhizophydium is genetically more variable than previously understood and actually represents multiple genera. In the present study, we use zoospore ultrastructural characters and 28 S rRNA and 5.8 S ribosomal gene sequences of 96 isolates in culture to circumscribe the monophyletic Rhizophydium clade as a new order, Rhizophydiales. Correspondingly, zoospores of members of the Rhizophydiales exhibit a unique suite of ultrastructural character states that further define the order and distinguish it from the order Chytridiales. Molecular analyses reveal several strongly supported clades within the Rhizophydiales. Three of those clades encompass a broad range of isolates and are defined as new families Rhizophydiaceae, Terramycetaceae, and Kappamycetaceae. To resolve close relationships within Terramycetaceae, combined 28 S rRNA and ITS1-5.8 S-ITS2 sequences were analysed and details of zoospore ultrastructural character states determined, with two new genera, Terramyces and Boothiomyces, described. Two species formerly classified in Rhizophydium are transferred to the new genera. This work provides a framework for additional taxonomic revisions within the new order Rhizophydiales and compares genetic variation useful in defining genera, species, and populations within this lineage of chytrids. A broader sampling of representatives is needed before taxonomic decisions can be made for remaining clades within the Rhizophydiales.

Base Sequence↗
PubMed2006

Mitochondrial dysfunction and ultrastructural damage in the hippocampus of pilocarpine-induced epileptic rat.

Mitochondrial dysfunction has been implicated as a contributing factor in epileptic seizures. Present studies were carried out to decipher seizure-dependent changes in mitochondrial function and ultrastructure in the chronic condition of temporal lobe epilepsy (TLE) induced by pilocarpine in rat hippocampus. Enzyme assay revealed significant depression of the activity of mitochondrial- and nuclear-encoded cytochrome oxidase (COX). Conversely, the activity of nuclear-encoded succinate dehydrogenase (SDH) remained unchanged. Discernible mitochondrial ultrastructural damage, varying from swelling to disruption of membrane, was observed in the hippocampus. Quantitative real-time PCR and Western blotting showed the expression of mitochondrial-encoded COX subunit III (COXIII) dropped significantly during the chronic seizure activity; the corresponding expression of COX subunit IV (COXIV) displayed no significant change. Most likely, our results suggest that dysfunction of mitochondrial COX respiratory enzyme and mitochondrial ultrastructural damage in the hippocampus are associated with prolonged seizure during experimental TLE and mitochondria are more vulnerable to epilepsy.

Animal Diseases↗
PubMedDate not supplied

Ultrastructure of canine meninges after repeated epidural injection of S(+)-ketamine.

BACKGROUND: The safety of ketamine when administered by the spinal route must be confirmed in various animal species before it is approved for use in humans. This study evaluates the ultrastructure of canine meninges after repeated doses of epidural S(+)-ketamine. METHODS: Five dogs received S(+)-ketamine 5%, 1 mg/kg, twice a day for 10 days through an epidural catheter with its tip located at the L5 level. One dog received the same volume of normal saline at the same times. The spinal cord and meninges were processed for histopathological and ultrastructural studies. Clinical effects were assessed after each injection. RESULTS: Motor and sensory block appeared after each injection of S(+)-ketamine, but not in the dog receiving saline. No signs of clinical or neurologic alterations were observed. Using light microscopy, no meningeal layer showed alterations except focal infiltration at the catheter tip level by macrophages, lymphocytes, and a few mast cells. The cells of different layers were studied by electron microscopy and interpreted according to data from human and other animal species because no ultrastructural description of the canine meninges is currently available. There were no cellular signs of inflammation, phagocytosis, or degeneration in meningeal layers and no signs of atrophy, compression, or demyelinization in the areas of dorsal root ganglia and spinal cord around the arachnoid. These findings were common for dogs receiving S(+)-ketamine and the dog receiving saline. CONCLUSION: Repeated doses of epidural S(+)-ketamine 5%, 1 mg/kg, twice a day for 10 days was not associated to cellular alterations in canine meninges.

Animals↗
PubMed2004

Morphological and ultrastructural analysis of sheep primordial follicles preserved in 0.9% saline solution and TCM 199.

The objective was to determine the morphological and ultrastructural features of sheep primordial follicles preserved in either 0.9% saline solution or TCM 199 at different temperatures. Soon after death, the ovarian pair of each ewe (n = 5) was divided into 25 fragments. One fragment was immediately fixed for morphological evaluation (control). The other 24 fragments were randomly distributed in tubes containing 2 ml of 0.9% saline solution or TCM 199 and maintained at 4, 20 or 39 degrees C for 2, 4, 12, or 24h. Based on histological assessment, storage of ovarian fragments in 0.9% saline solution at 20 degrees C for up to 24h and in both solutions at 39 degrees C for 4, 12 or 24h increased (P < 0.01) the percentage of degenerate primordial follicles compared with controls. In contrast, preservation at 4 degrees C in both solutions, kept the percentage of morphologically normal primordial follicles similar to control values. Although histological integrity of primordial follicles was maintained in fragments stored at 20 degrees C for up to 24h in TCM 199, these results were not confirmed by ultrastructural analysis. Based on transmission electron microscopy, only primordial follicles stored at 4 degrees C for up to 24h, at 20 degrees C for up to 12h and at 39 degrees C for up to 2h in both solutions were ultrastructurally normal. In conclusion, sheep primordial follicles were successfully preserved at 4 degrees C for up to 24h, at 20 degrees C for up to 12h and at 39 degrees C for 2h in 0.9% saline solution or TCM 199.

Animals↗
PubMed2004

Ultrastructure of Pagrus major and Rhabdosargus sarba spermatozoa (Perciformes: Sparidae: Sparinae).

Transmission and scanning electron microscopy were used to investigate the ultrastructure of spermatozoa in two Sparinae species Pagrus major and Rhabdosargus sarba. Ultrastructurally, the spermatozoa of P. major and R. sarba both consist of a spherical, homogeneously electron-dense nucleus with a deep axial nuclear fossa, and an unusual notch, in the nuclear region. The midpiece contains two spherical mitochondria in R. sarba and one in P. major. The comparison of spermatozoal ultrastructure of these two species of Sparidae shows that they closely resemble one another and suggests that they are closely related. Variation in the geometry and dimensions of the mitochondrion and nucleus is substantial in these two Sparidae species. It is concluded that the spermatozoa of both species are of primitive type, and they are distinguished by several unique features which may provide useful systematic characteristics.

Animals↗
PubMed2004

Ultrastructure of early jurassic fossil plant cuticles: Pachypteris gradinarui Popa.

Exceptional preservation of extinct Pachypteris extra-epidermal cuticle enabled the first detailed statistical measurements of its ultrastructure using transmission electron microscopy. Pachypteris is a leaf genus of the Mesozoic belonging to seed fern foliage of the order Corystospermales. The species studied in this paper is Pachypteris gradinarui Popa [Rev. Palaeobot. Palynol. 111 (2000) 31], based on fossils which are Early Jurassic in age (Hettangian-Sinemurian, approximately 205-190 million years old). Both the upper and the lower cuticles were thoroughly examined, including the detail of the stomatal complexes and epidermal cells. The data obtained from our TEM analysis, together with the confidence intervals, were very useful to give precise description of the cuticles as they distinguished between upper and lower epidermal and stomatal cell types. Moreover a combination of characters was used to develop the first dichotomous key based on ultrastructural characters, i.e. not only the total thickness of the cuticle but also details and proportions of A cuticle proper and B cuticular layer. Comparisons with ultrastructures known from other Pachypteris species show that the influence of space and time, diagenetic processes, and/or processes related to technical procedures, seem to be minimal within this genus. Detailed studies of this type may be very useful for further comparisons among other species and at higher taxonomical ranks.

Fossils↗
PubMed2005

Two-dimensional ultrastructural elements lead to three-dimensional reconstruction of protuberances on the cocoon membrane of the leech, Theromyzon tessulatum.

Protuberances on the cocoon surface of the leech, Theromyzon tessulatum, are roughly parallel rows of triangular prisms arranged equidistantly to each other on the outer surface of the cocoon membrane. The distance between neighboring protuberances is approximately 1.6 microm, the height approximately 0.5 microm and the semi-width approximately 0.3 microm. The fibrillar arrangement within the protuberance maintains some elements of the helicoids found within the cocoon membrane but a high proportion of large holes disrupt the symmetry of the protuberance ultrastructure. A procedure for 3D reconstruction of the protuberance using the complementarity between the paratangential and normal sections through the cocoon is presented. Our results demonstrate that the ultrastructure of protuberances show elements of a twisted fibrillar arrangement, but the demands of filling a narrow space ruled by acute angles appears to cause a high degree of ultrastructural disorganization.

Animals↗
PubMed2006

Partial development of the steroidogenic ultrastructural features in degenerative corpora lutea after a single injection of pituitary extract in the Western painted turtle (Chrysemys picta).

Pituitary glands were removed from sexually mature female turtles (Chrysemys picta) and they were injected intraperitoneally (i.p.) into other mature females of the same species (experimental). In addition mature females of the same species received saline injection only (controls). Initially all the turtles used in this study were steroidogenically inactive with corpora lutea already undergoing luteolysis (degeneration) as these turtles had ovioposited their eggs approximately 2 weeks earlier. Forty-eight hour post injection the corpora lutea were removed from the control and experimental turtles. In the experimental turtles, the lutein granulosa cells developed ultrastructural features such as tubular and cisternal smooth endoplasmic reticulum (SER) and mitochondria with tubular cristae associated with lipid droplets. However, the controls maintained degenerative corpora lutea without steroidogenic ultrastructural features. The circulating progesterone (Pro) levels in the experimental turtles were significantly higher than the controls (P<0.049). Although the 48h development of steroidogenic ultrastructural features in the lutein granulosa cells was only partial in development, the effect of the pituitary taken from the inactive donor triggered an activating process within a short period, clear evidence of gonadotropic effect on the inactive corpora lutea. The present data offer interesting information on the short-term effect of gonadotropins during the non-reproductive period. This information may have useful implication under natural conditions particularly during the onset of a new reproductive cycle where the ovary is still inactive.

Animals↗
PubMed2006

Expression of apoptotic nuclei by ultrastructural terminal deoxyribonucleotidyl transferase mediated dUTP nick end labeling and detection of FasL, caspases and PARP protein molecules in cadmium induced acute alveolar cell injury.

Cadmium causes cellular damage but the exact mechanism of apoptosis in cadmium induced acute lung injury is not clear. We investigated the sequential expression of apoptotic nuclei and detected related molecules in tissue of cadmium-induced acute lung injury. Forty Sprague-Dawley rats were sacrificed at days 1, 3, 7 and 10 after intra-tracheal cadmium injection (2.5mg/kg). Light microscopic, ultrastructural terminal deoxyribonucleotidyl transferase mediated dUTP nick end labeling (TUNEL), and Western blot analysis for detection of FasL, Bid, cytochrome c, caspase 3 and PARP were carried out. Apoptosis occurred at day 1, and markedly decreased at days 3, 7 and 10 (11.8, 2.8, 0.9, 0.5%, respectively) determined by light microscopy and TUNEL assay. Ultrastructural TUNEL revealed two patterns of nuclear morphology according to the apoptotic stage. One pattern showed chromatin fragmentation and apoptotic nuclear body formation. The other pattern had bleb formation in the chromatin, budding with projection out to the nuclear membranes, fragmentation, segregation of chromatin clumps and apoptotic body formation. Western blot analysis showed prominent expression of FasL at days 1 and 3. Expression of Bid, cytochrome c and caspase 3 were prominent at day 1 compared to days 3, 7 and 10. PARP cleavage was prominent at day 1. In conclusion, intra-tracheal cadmium injection showed active alveolar cell apoptosis at day 1. Ultrastructural TUNEL showed various expressions according to the apoptotic nuclear stage. These studies suggest that cadmium-induced alveolar cell apoptosis is mediated by FasL and caspase-dependent mitochondrial apoptosis pathways.

Animals↗
PubMed2005

Identification of ultrastructural changes in liver allografts of patients experiencing primary nonfunction.

BACKGROUND: Primary nonfunction (PNF) after liver transplantation is fatal without timely retransplantation. PNF has been associated with many risk factors, but the etiology remains unknown in most cases. Using electron microscopy, we examined the hepatic ultrastructure of donor allografts in patients experiencing PNF and compared the findings with a well-matched group of other donor allografts. MATERIALS AND METHODS: Archival paraffin-embedded pre- and post-reperfusion donor liver biopsies were examined by electron microscopy in 10 patients with PNF and in 10 controls, matched by donor age +/- 5 years, gender, cold ischemic time +/- 1 hour, and donor cause of death. Mitochondria, endoplasmic reticulum, sinusoidal endothelial cells, and the glycogen content of the cells were assessed. The donors' serum peak transaminases, bilirubin and sodium levels, as well as the recipient age and serum creatinine were compared. RESULTS: There were no significant differences in recipient age at the time of transplantation, peak recipient serum creatinine, donor peak serum transaminase, sodium or bilirubin levels. In all cases, the endoplasmic reticulum and sinusoidal endothelial cells were ultrastructurally normal. Hepatocytes had variable degrees of glycogen pooling. Hepatic steatosis and intramitochondrial inclusions cells were present in 5/10 PNF compared to 0/10 controls patients on preperfusion liver biopsy (P = .17). CONCLUSION: Liver allografts from patients suffering from PNF can have mitochondrial ultrastructural changes on preperfusion biopsies.

Adult↗
PubMed2005

Ultrastructural changes of the palatal mucosa following application of 4-nitroquinoline-l-oxide (4NQO) in rats subjected to major salivary gland excision.

OBJECTIVE: It has been suggested that saliva exerts a protective role against the carcinogenic effect of various substances in the oral cavity. The objective of this study was to examine the ultrastructural changes of the palatal mucosa caused by the application of 4-nitroquinoline-l-oxide (4NQO) in the presence or absence of saliva. STUDY DESIGN: Wistar-Furth rats subjected and not subjected to total bilateral excision of the major salivary glands were either painted with an aqueous solution of 4NQO or with propylene glycol only (controls). Two animals of each group were humanely killed periodically. The areas of the palatal lesions were immediately sliced and processed for TEM examination. RESULTS: Ultrastructurally, the progressive changes to squamous cell carcinoma were observed in the animals painted with 4NQO. In the desalivated animals group, the ultrastructural alterations appeared earlier than in the group with salivary glands. CONCLUSIONS: Saliva appeared to delay but not hinder tumor induction by 4NQO.

4-Nitroquinoline-1-oxide↗
PubMed2002

Ultrastructure of cultured cells from Schistosoma japonicum.

Ultrastructures and their dynamic changes of the cultured cells from Schistosoma japonicum were observed in the present experiments. Several types-including polygonal, round granular, deltaic fan-shaped and flagellated cells-were found in the cultures. The polygonal cells took a major ratio in the cultures from adult S. japonicum, while the majority from schistosomula was round granular cells. The ultrastuctures on the cell surface were different between the cells from adults and schistosomula. Some papilla-like tubercula, microvilli and pinocytotic vesicles were observed on the surface of adult cells, but none were found on schistosomula cells. However, more or less mitochondria, endoplasmic reticula, ribosomes and glycogen were observed in the cytoplasm of the cultured cells from both adults and schistosomula. Golgi complexes were rarely found. The nucleus was round, with round nucleolus inside and clear pores on the unit membrane. There was much lumpish heterochromatin located near to the nuclear membrane. Cells from different worm tissues had their own organelles. The germ cells, vitelline cells, flame cells, multinucleate subtegumental cells and nerve cells could be observed in the cultures from adults. The vitelline cells were the greatest in number and nerve cells were the least in number among them. Similarly, there were germ cells, sustentacular cells, flame cells, nerve cells, mast cells, muscle cells, multinucleate subtegumental cells, interstitial cells and penetration gland cells in the cultures from the schistomomula. In addition, a few division cells were also found. It indicated that the schistosomula cells had greater potential ability to proliferate than the adult cells in in vitro culture. Along with the prolongation of the culture time, degeneration of schistosomal cell occurred more and more. Generally, the electron density of cultures gradually got lower, the cristae of mitochondria blurred and disappeared and the mitochondria themselves swelled and finally vacuoled completely. Vitelline cells were most sensitive to the changes of the in vitro condition in all cultures. Their degeneration showed the following characteristics: (1) vitelline globules fused each other, the space between vitelline globules and the membrane surrounding them broadened gradually and vitelline globules were released and uncovered; (2) rough-surfaced endoplasmic reticula enlarged, vacuolated and the ribosomes dropped; and (3) the number and volume of lipid increased. The ultrastructural changes of most of the cultures from schistosomula had the following trends: (1) heterochromatin increased and euchromatin decreased gradually; and (2) endoplasmic reticula changed into short tubes and vacuoles and disappeared finally. The degenerative process of the cultures from S. japonicum consisted of necrosis according to the ultrastructural changes of the mitochondria, vitelline globules, chromatin and endoplasmic reticula within the cells. The changes of the above structures could be used to estimate whether the culture conditions were appropriate.

Animals↗
PubMed2003

Ultrastructural observation of spermatozoa and fertilization in Schistosoma japonicum.

The ultrastructure of the sperm and the process of fertilization are described in Schistosoma japonicum. The sperm of S. japonicum has an elongated head and a single tail. The head measures 6.2 x 1.4 microm in average size. No acrosome is present. A mass of mitochondria locates in front of the nucleus. A layer of about 100-120 peripheral microtubules is parallel with the long axis of the head under plasma membrane. The nucleus is dense with some electron-lucent patches. The tail is a single flagellum with unique axoneme, which originates from a centriole. The structure of axoneme includes two types: 9 x 2 + < > in the main part of the flagellum, and 9 x 2 + 0 near the end of the flagellum. The sperm ultrastructure of S. japonicum is similar to that of other schistosomes, apart from the fact that two types of configuration coexisted in the same axoneme, and there is no striated root found in S. japonicum. The sperm differs distinctly from other Digenea. The aberrant ultrastructure of S. japonicum reflects that its evolution is far away from other genera in Digenea. Fertilization occurs at the posterior part of oviduct, in which region the oviduct wall lacks lamellae. Some cortical granules (CG) fuse with plasma membrane, and discharge their content on the surface of the fertilized ovum. The other CGs break down or degenerate in the cytoplasm. By the secondary mature division, the secondary oocyte finally divides to form a female pronucleus. During this period a male pronucleus also forms. The female and male pronucleus approach each other, come into contact in the central region and finally fuse to form a zygote. The function of CGs is discussed.

Animals↗
PubMed1984

Ultrastructure of normal, metaplastic, and abnormal human uterine cervix: use of montages to study the topographical relationship of epithelial cells.

The ultrastructure of the entire thicknesses of normal and abnormal human uterine cervical epithelia is studied with the use of slit-type grids. In four normal squamous epithelial specimens, basic similarities in the maturational sequence were apparent; however, significant variation in the progression of differentiation was also obvious. Because of this variation, it was not possible to always correlate cellular structure with cellular location within the epithelial strata. Four normal specimens containing combinations of squamous, columnar, and metaplastic cells show variations in the topographical relationships of these cells and stages in the transition of reserve to squamous cells in metaplastic zones. The presence of cells with features characteristic of squamous and columnar epithelia suggests a bipotentiality of reserve cells. Six abnormal specimens share several morphologic features, which usually, but not regularly, vary quantitatively with the extent of abnormality. Because of the inconsistent gradation of cellular features with lesion severity, it was essential that numerous ultrastructural parameters be considered in order to evaluate the extent of abnormality. Cellular features peculiar to individual specimens include edema, keratinization, phagocytic squamous cells, and cells similar in appearance to koilocytes described in condylomas. Electron micrograph montages of extensive unobstructed areas of normal and abnormal cervices and higher-magnification micrographs of cell components provide improved documentation of the variation in morphology of normal and abnormal epithelia. Use of montages also results in a clear view of ultrastructural changes accompanying the transition from normal to abnormal cervical epithelium.

Basement Membrane↗
PubMed1980

Ultrastructural features of progressive idiopathic epiretinal membrane removed by vitreous surgery.

Clinical and electron microscopic studies of an idiopathic epiretinal membrane that was nonvascularized and progressive showed three types of cells: (1) predominant, fibrocyte-like cells; (2) macrophage-like cells; and (3) glial cells. Most of the abundant collagen showed characteristics of normal vitreous fibrils, although thicker collagen fibrils were also present. These ultrastructural findings, when compared with previously reported features of simple and secondary epiretinal membranes, suggest that clinically complicated epiretinal membranes are composed of more than one cell type, whereas simple epiretinal membranes consist only of glial cells. The fibrocyte-like and macrophage-like cells seen in our case were interpreted as being hyalocytes, rather than being derived from glial or retinal pigment epithelial cells. We support this interpretation by the ultrastructural features of the cells, the presence of abundant normal vitreous collagen, the biologic characteristics of hyalocytes as described by other investigators, and the absence of the ultrastructural features of glial or retinal pigment epithelial cells.

Adult↗