The ultrastructure of the cuticle of the nematode Syphacia obvelata (Rudolphi, 1802). I. The body cuticle of larvae, males,and females, and observations on its development

1973 ◽  
Vol 51 (2) ◽  
pp. 187-196 ◽  
Author(s):  
T. A. Dick ◽  
K. A. Wright
Keyword(s):  
Electron Microscopy ◽  
Young Adults ◽  
Growth Phase ◽  
Light And Electron Microscopy ◽  
The Body ◽  
Median Zone ◽  
Progressive Growth ◽  
Males And Females ◽  
Body Cuticle ◽  
Syphacia Obvelata

The body cuticle of Syphacia obvelata (Rudolphi, 1802) has been examined with light and electron microscopy through larval and adult stages. In all stages the cuticle consists of a cortex, and median and basal zones. Material showing transverse striations with 180–220 Å periodicity (striated material) occurs in the median zone of larvae and young adults. However, progressive growth and deposition of more striated material results in the cuticle of older females appearing markedly different from the cuticle of the short-lived males. Striated material is concluded to be formed of bands of approximately circular discs. Overlap of such bands produces the various patterns seen in sections. Similarities between methods of formation of striated material and other cuticular components are noted between molting periods and the growth phase of females. The presence of intracuticular tubules and external longitudinal ridges is noted.

The ultrastructure of the cuticle of the nematode Syphacia obvelata (Rudolphi, 1802). II. Modifications of the cuticle in the head end

1973 ◽  
Vol 51 (2) ◽  
pp. 197-202 ◽  
Author(s):  
T. A. Dick ◽  
K. A. Wright
Keyword(s):  
Body Wall ◽  
Buccal Capsule ◽  
The Body ◽  
Head Region ◽  
Limited Region ◽  
Structural Role ◽  
Mouth Cavity ◽  
Median Zone ◽  
Syphacia Obvelata ◽  
Somatic Muscles

The head region of the pinworm Syphacia obvelata (Rudolphi, 1802) has been examined to determine the nature of modification of the cuticle responsible for, or associated with, lips and buccal capsule, cephalic papillae and amphids, cephalic inflations, and cervical alae. The median zone of the cuticle was found to be the most modified and variation in the extent and distribution of striated material is compatible with its proposed structural role. The variations found are probably related to compensation for stresses that may develop in the cuticle during the complex movements of the head end. Lips are only inconspicuous expansions of the body wall cuticle, while esophageal cuticle is strikingly different in appearance. It is proposed to refer to all regions of the mouth cavity bounded by both the lips and esophagus as the buccal capsule while only the limited region bounded by body wall cuticle may be referred to as stoma. A mechanism involving three groups of intrahypodermal cytoskeletal filaments attached to the tips of somatic muscles, esophagus, and cuticle is proposed to move the lips.

Directed regrowth of axons from a misrouted nerve to their correct muscles in the limb of the adult newt

1984 ◽  
Vol 222 (1229) ◽  
pp. 477-489 ◽  
Keyword(s):  
Electron Microscopy ◽  
Extracellular Matrix ◽  
Nervous System ◽  
Nerve Regeneration ◽  
Body Wall ◽  
Cobalt Chloride ◽  
Light And Electron Microscopy ◽  
Growth Cones ◽  
The Body ◽  
Forearm Flexor

When the forearm flexor nerve (f.f.n.) of the newt forelimb is surgically rerouted to the ventral body wall, regrowth of axons occurs and these axons reinnervate the muscle targets of the f.f.n. This process of nerve regeneration has been studied in detail over a 12 week period by using light and electron microscopy, electrophysiology and nerve fibre tracking after filling with cobalt chloride. The regrowing axons were analysed by electron microscopy and it is shown that they derive from the rerouted nerve at the position at which the f.f.n. leaves its normal ventral limb pathway. Axons in the pathway do not originate from the cut end of the f.f.n. on the ventral body wall. The regrowing axons are identified within the body of the rerouted nerve and they leave the f.f.n. by growing through the perineurium. Schwann cells are invariably associated with the regrowing axons and the pathway through which the growth cones and neurites grow consists predominantly of extracellular matrix fibrils. The stages of maturation of the regenerated f.f.n. including fasiculation of neurites, myelination and reformation of a perineurium are also described. The results of the study are discussed in terms of current ideas as to how specific regeneration of a correct and functional peripheral nervous system is achieved in urodele amphibians.

Development of the gut and segmentation of newly settled stages of Ridgeia (Vestimentifera): implications for relationship between Vestimentifera and Pogonophora

1988 ◽  
Vol 68 (3) ◽  
pp. 465-487 ◽  
Author(s):  
Eve C. Southward
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
The Body ◽  
Bacterial Symbiosis ◽  
Sem And Tem ◽  
Trochophore Stage

Young vestimentiferans, ranging from 0.15 to 10 mm in length, were examined by light and electron microscopy (SEM and TEM). The newly settled stages have a functional gut and traces of larval ciliation, which suggests that they may have developed from a planktonic trochophore stage. The larval mouth becomes an elongated siphon and the ciliated gut persists for some time after the development of the bacterial symbiosis in the trophosome. The segmentation of the body in the earliest stages is similar to that in postlarval Pogonophora, and it is concluded that Vestimentifera and Pogonophora are closely related.

Scanning electron microscopy and intraspecific variation in Euchordodes nigromaculatus from New Zealand

1998 ◽  
Vol 72 (1) ◽  
pp. 65-70 ◽  
Author(s):  
A. Schmidt-Rhaesa ◽  
F. Thomas ◽  
R. Poulin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Zealand ◽  
Intraspecific Variation ◽  
Body Length ◽  
Original Description ◽  
The Body ◽  
Body Cuticle ◽  
Cloacal Opening ◽  
Scanning Electron

AbstractTaxonomic characters of the male posterior end and the body cuticle of Euchordodes nigromaculatus (Nematomorpha) were described by scanning electron microscopy (SEM) and compared with the original description by Poinar (1991a) and with other Euchordodes species. Intraspecific variation was found in the body length, the distance between the cloacal opening and the posterior end and especially in the form of the male posterior end. The latter either possesses two short lobelike structures and a ventral groove or lacks these structures. The importance of SEM investigations and observations of intraspecific variation is stressed for the taxonomy of nematomorph species.

Ontogenesis of corneal surface ultrastructure in nocturnal Lepidoptera

1971 ◽  
Vol 262 (843) ◽  
pp. 343-363 ◽  
Keyword(s):  
Light And Electron Microscopy ◽  
Spatial Relationship ◽  
Membrane System ◽  
The Body ◽  
Corneal Surface ◽  
Surface Ultrastructure ◽  
New Material ◽  
Body Cuticle ◽  
The One ◽  
Irregular Arrangement

The morphogenesis of epicorneal structures in nocturnal Lepidoptera was studied with light and electron microscopy. During the first 4-5 days after pupation, microvilli (with their tips hexagonally distributed) arose gradually from the corneagenous cell surface. At the time of onset of moulting (about 5 days after pupation), patches of lamellar elements appeared distal to the tips of the microvilli. There was one patch for each microvillus from which the patch was separated by a narrow cleft. The cleft was traversed by a few thin bridges which seemed to originate in the microvillus. The bridges were interpreted to be extracellular continuations of intramicrovillar filaments and to insert on the proximal surface of the patch. At about 5 1/2 days after pupation, the patches were seen to be composed of two outer electron-dense lines and a less distinct, inner and thicker dense line. The patches bulged markedly, their concavity turned towards the microvillar tip. A number of discrete bridges extended between the microvillus and the base of the patch, which now appeared as a low dome. The bases of the domer later coalesced to form a continuous lamellar 'membrane' system ( epicorneal lamina , ECL), and the concavity of the domes increased, forming successively deeper lamina evagmations (LE) which strictly retained their spatial relationship to the tips of the microvilli (MV) throughout the ontogenesis. Growth of the ECL evaginations to form an array of successively higher cupoles—and, finally, the complete nipple anlage-was suggested to take place by addition of new material at all points of the LE surface within the palisade of MV/LE bridges. The latter were proposed to act as structures of constraint preventing the ECL to buckle randomly and causing the evaginations to develop in a regular fashion. The results were compared with those described in reports on the morphogenesis of the body cuticle of insects. It was proposed that different types of corneal surface protuberances (corneal nipples of various heights; low protrusions in regular or irregular arrangement) as well as some types of surface lpturing in the body cuticle of insects may be produced on the basis of the same mechanism as the one described for the formation of the full-sized nipples of nocturnal Lepidoptera

The Morphology of Vacuolated Cells in the Liver Following Administration of Vitamin A.

1973 ◽  
Vol 31 ◽  
pp. 408-409
Author(s):  
Odell T. Minick ◽  
Hidejiro Yokoo ◽  
Fawzia Batti
Keyword(s):  
Electron Microscopy ◽  
Body Weight ◽  
Vitamin A ◽  
Light And Electron Microscopy ◽  
Liver Cells ◽  
Prominent Feature ◽  
Vascular Space ◽  
Vacuolated Cell ◽  
Vacuolated Cells ◽  
Vacuolated Cytoplasm

Vacuolated cells in the liver of young rats were studied by light and electron microscopy following the administration of vitamin A (200 units per gram of body weight). Their characteristics were compared with similar cells found in untreated animals.In rats given vitamin A, cells with vacuolated cytoplasm were a prominent feature. These cells were found mostly in a perisinusoidal location, although some appeared to be in between liver cells (Fig. 1). Electron microscopy confirmed their location in Disse's space adjacent to the sinusoid and in recesses between liver cells. Some appeared to be bordering the lumen of the sinusoid, but careful observation usually revealed a tenuous endothelial process separating the vacuolated cell from the vascular space. In appropriate sections, fenestrations in the thin endothelial processes were noted (Fig. 2, arrow).

Electron Microscopy of Mycoplasma Pneumoniae

1971 ◽  
Vol 29 ◽  
pp. 258-259 ◽  
Author(s):  
E. S. Boatman ◽  
G. E. Kenny
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Growth Phase ◽  
Hela Cells ◽  
Sulfonic Acid ◽  
Gamma Globulin ◽  
Horse Serum ◽  
Morphological Aspects ◽  
The Family

Information concerning the morphology and replication of organism of the family Mycoplasmataceae remains, despite over 70 years of study, highly controversial. Due to their small size observations by light microscopy have not been rewarding. Furthermore, not only are these organisms extremely pleomorphic but their morphology also changes according to growth phase. This study deals with the morphological aspects of M. pneumoniae strain 3546 in relation to growth, interaction with HeLa cells and possible mechanisms of replication.The organisms were grown aerobically at 37°C in a soy peptone yeast dialysate medium supplemented with 12% gamma-globulin free horse serum. The medium was buffered at pH 7.3 with TES [N-tris (hyroxymethyl) methyl-2-aminoethane sulfonic acid] at 10mM concentration. The inoculum, an actively growing culture, was filtered through a 0.5 μm polycarbonate “nuclepore” filter to prevent transfer of all but the smallest aggregates. Growth was assessed at specific periods by colony counts and 800 ml samples of organisms were fixed in situ with 2.5% glutaraldehyde for 3 hrs. at 4°C. Washed cells for sectioning were post-fixed in 0.8% OSO4 in veronal-acetate buffer pH 6.1 for 1 hr. at 21°C. HeLa cells were infected with a filtered inoculum of M. pneumoniae and incubated for 9 days in Leighton tubes with coverslips. The cells were then removed and processed for electron microscopy.

Control of Autogenous Vein Grafts Prior to Reimplantation, By Electron Microscopy

1972 ◽  
Vol 30 ◽  
pp. 106-107
Author(s):  
John H. L. Watson ◽  
John L. Swedo ◽  
M. Vrandecic
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Physiological Saline ◽  
Experimental Conditions ◽  
Vein Grafts ◽  
Arterial Blood ◽  
Saphenous Veins ◽  
Autogenous Vein ◽  
Control Of Parameters ◽  
Post Implantation

The ambient temperature and the nature of the storage fluids may well have significant effects upon the post-implantation behavior of venus autografts. A first step in the investigation of such effects is reported here. Experimental conditions have been set which approximate actual operating room procedures. Saphenous veins from dogs have been used as models in the experiments. After removal from the dogs the veins were kept for two hours under four different experimental conditions, viz at either 4°C or 23°C in either physiological saline or whole canine arterial blood. At the end of the two hours they were prepared for light and electron microscopy. Since no obvious changes or damage could be seen in the veins by light microscopy, even with the advantage of tissue specific stains, it was essential that the control of parameters for successful grafts be set by electron microscopy.

Ultrastructure of two neoplasms in culture compared with original biopsies

1984 ◽  
Vol 42 ◽  
pp. 50-51
Author(s):  
Joseph M. Harb ◽  
James T. Casper ◽  
Vlcki Piaskowski
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Biopsy Specimen ◽  
Cultured Cells ◽  
Light And Electron Microscopy ◽  
Human Tumor ◽  
Soft Agar ◽  
Human Tumor Cells ◽  
Morphological Distinction ◽  
Tumor Types

The application of tissue culture and the newer methodologies of direct cloning and colony formation of human tumor cells in soft agar hold promise as valuable modalities for a variety of diagnostic studies, which include morphological distinction between tumor types by electron microscopy (EM). We present here two cases in which cells in culture expressed distinct morphological features not apparent in the original biopsy specimen. Evaluation of the original biopsies by light and electron microscopy indicated both neoplasms to be undifferentiated sarcomas. Colonies of cells propagated in soft agar displayed features of rhabdomyoblasts in one case, and cultured cells of the second biopsy expressed features of Ewing's sarcoma.

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