scholarly journals The Giardia Median Body Protein Is a Ventral Disc Protein That Is Critical for Maintaining a Domed Disc Conformation during Attachment

2012 ◽  
Vol 11 (3) ◽  
pp. 292-301 ◽  
Author(s):  
David J. Woessner ◽  
Scott C. Dawson
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Shear Forces ◽  
Bare Area ◽  
Body Protein ◽  
Content Type ◽  
Intestinal Epithelia ◽  
Normal Forces ◽  
Membrane Contacts ◽  
Ventral Disc

ABSTRACTGiardiahas unique microtubule structures, including the ventral disc, the primary organelle of attachment to the host, and the median body, a structure of undefined function. During attachment, the ventral disc has a domed conformation and enablesGiardiato attach to the host intestinal epithelia within seconds. The mechanism of attachment via the ventral disc and the overall structure, function, and assembly of the ventral disc are not well understood. Our recent proteomic analysis of the ventral disc indicated that the median body protein (MBP), previously reported to localize exclusively to the median body, was primarily localized to the ventral disc. Using high-resolution light and electron microscopy, we confirm that the median body protein localizes primarily to the overlap zone of the ventral disc. The MBP also occasionally localized to the median body during prophase. To define the contribution of MBP to the ventral disc structure, we depleted MBP using an anti-MBP morpholino. We found that the ventral disc was no longer able to form properly and that the disc structure often had an aberrant nondomed or flattened horseshoe conformation. The ability of attached anti-MBP morpholino-treated trophozoites to withstand shear forces and normal forces was significantly decreased. Most notably, the plasma membrane contacts with the surface, including those of the bare area, were defective after the anti-MBP knockdown. To our knowledge, this is the first ventral disc protein whose depletion directly alters ventral disc structure, confirming that the domed ventral disc conformation is important for robust attachment.

Xenogeneic pericardium as a dural substitute in reconstruction of suboccipital dura mater in children

1989 ◽  
Vol 70 (6) ◽  
pp. 905-909 ◽  
Author(s):  
Jan Pařízek ◽  
Pavel Měřička ◽  
Josef Špaček ◽  
Stanislav Němeček ◽  
Pavel Eliáš ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Dura Mater ◽  
Light And Electron Microscopy ◽  
Fascia Lata ◽  
Content Type ◽  
Dural Substitute ◽  
Freeze Dried ◽  
Materials Used ◽  
Neurosurgical Techniques ◽  
Fine Print

✓ A 5-year experience with the glutaraldehyde-stabilized freeze-dried radiation-sterilized calf pericardium used as a dural substitute is reported. The structure of pericardium xenograft is compared with other collagenous materials used for duraplasty (allogeneic fascia lata and dura mater) by light and electron microscopy. The special neurosurgical techniques involved in using pericardium xenografts in the reconstruction of suboccipital dura mater in children are presented in detail.

Presence of smooth-muscle cells in the subdural neomembrane

1981 ◽  
Vol 54 (5) ◽  
pp. 646-651 ◽  
Author(s):  
Nobuyuki Kawano ◽  
Kinuko Suzuki
Keyword(s):  
Electron Microscopy ◽  
Smooth Muscle ◽  
Light Microscopy ◽  
Smooth Muscle Cells ◽  
Subdural Hematoma ◽  
Light And Electron Microscopy ◽  
Chronic Subdural Hematoma ◽  
Muscle Cells ◽  
Content Type ◽  
Fine Print

✓ The authors encountered a case of chronic subdural hematoma of which the subdural neomembrane (SN) showed numerous spindle-shaped cells identified as smooth-muscle cells (SMC's) by electron microscopy. On reexamination of 214 cases from the files, SMC's were found with light microscopy in seven cases. In these cases, the SN was well organized (collagenized). In three additional cases examined with both light and electron microscopy, SMC's were not apparent with light microscopy. However, in all cases, cells with ultrastructural features of both fibroblasts and SMC's were observed. Well formed SMC's were found in two additional cases of well organized membrane. Based on these observations, it is concluded that the presence of SMC's in the SN is not a rare phenomenon. The possible origin of SMC's in the SN and their pathological significance to the organizing process of chronic subdural hematoma are discussed.

Prolactinoma of pituitary with associated amyloid-like substances

1983 ◽  
Vol 59 (6) ◽  
pp. 1067-1070 ◽  
Author(s):  
Jun-ichi Kuratsu ◽  
Yasuhiko Matsukado ◽  
Masaki Miura
Keyword(s):  
Electron Microscopy ◽  
Pituitary Adenoma ◽  
Tumor Cells ◽  
Pituitary Adenomas ◽  
Light And Electron Microscopy ◽  
Rare Entity ◽  
Short History ◽  
Content Type ◽  
History Of ◽  
Fine Print

✓ A prolactin-secreting pituitary adenoma containing amyloid substance was studied by light and electron microscopy. The tumor was found in a 32-year-old woman who presented with a short history of amenorrhea and galactorrhea. Pituitary adenoma containing amyloid substance is a very rare entity, and the implications of this association are discussed. Previous reports, suggesting that mesenchymal cells or hormone-secreting tumor cells in pituitary adenomas produce amyloid substances, are reviewed.

Brain damage from 125I brachytherapy evaluated by MR imaging, a blood-brain barrier tracer, and light and electron microscopy in a rat model

1990 ◽  
Vol 73 (4) ◽  
pp. 585-593 ◽  
Author(s):  
Mark Bernstein ◽  
Tom Marotta ◽  
Patricia Stewart ◽  
Jennifer Glen ◽  
Lothar Resch ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mr Imaging ◽  
Blood Brain Barrier ◽  
Light And Electron Microscopy ◽  
Brain Barrier ◽  
Content Type ◽  
Blood Brain Barrier Disruption ◽  
Blood Brain ◽  
Normal Rat ◽  
Brain Barrier Disruption

✓ Changes in normal rat brain were studied acutely, and at 3, 6, 9, and 12 months following interstitial brachytherapy with high-activity 125I seeds. An 80-Gy radiation dose was administered to an area with a 5.5-mm radius. Effects were measured with magnetic resonance (MR) imaging (with and without gadolinium enhancement), leakage of horseradish peroxidase(HRP), electron microscopy, and light microscopy. Significant histological damage was seen at radiation doses above 295 Gy, and breakdown of the blood-brain barrier was observed only in tissue receiving a dose of 165 Gy or greater. Blood-brain barrier breakdown increased up to the 6-month time point, and thereafter appeared to stabilize or decrease. The area of blood-brain barrier disruption indicated by gadolinium-enhanced MR imaging was greater than that indicated by leakage of HRP.

Neuronal alterations in developing cortical infarction

1974 ◽  
Vol 40 (2) ◽  
pp. 186-198 ◽  
Author(s):  
John R. Little ◽  
Thoralf M. Sundt ◽  
Frederick W. L. Kerr
Keyword(s):  
Electron Microscopy ◽  
Electron Density ◽  
Light And Electron Microscopy ◽  
Fluid Exchange ◽  
Content Type ◽  
Cortical Infarction ◽  
Nuclear Pyknosis ◽  
Ischemic Tissue ◽  
Fluid Transfer ◽  
Neural Membranes

✓ The sequential neuronal alterations that occur during the early phase of developing cortical infarction in the squirrel monkey were studied by light and electron microscopy. A technique used to select ischemic tissue based on spectrophotometry is described. Neuronal shrinkage, characterized by angularity, cytoplasmic eosinophilia, and nuclear pyknosis on light microscopy and by an increase in electron density of the cytoplasmic and nucleoplasmic matrix on electron microscopy, was the predominant reaction. The increased electron density of the cytoplasm and nucleoplasm suggested a diffuse alteration at the molecular level and the appearance of this abnormality between 3 and 6 hours corresponded with the development of an irreversible neurological deficit. In contrast, approximately 10% of the neurons became very swollen and pale. The pattern of perineuronal astrocytic alterations suggested that some form of interaction involving fluid transfer may exist between astrocyte and neuron and that shrinkage or swelling of neurons may depend in part upon the presence or absence of direct fluid exchange with astrocytes. Most terminal boutons became progressively shrunken and dense resembling the changes which occur in anterograde axonal degeneration. Swelling and fragmentation of large lysosomes occurred at 12 hours. Disruption of neural membranes was widespread by 24 hours and was more severe in swollen neurons.

Symptomatic Rathke's cleft cyst

1977 ◽  
Vol 47 (3) ◽  
pp. 451-458 ◽  
Author(s):  
Jun Yoshida ◽  
Tatsuya Kobayashi ◽  
Naoki Kageyama ◽  
Masaki Kanzaki
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Rare Case ◽  
Light And Electron Microscopy ◽  
Rathke’S Cleft Cyst ◽  
Rathke's Cleft Cyst ◽  
Content Type ◽  
Rathke's Cleft ◽  
Fine Print

✓ A rare case is reported in which a symptomatic Rathke's cleft cyst was studied by light and electron microscopy and tissue culture. The findings are compared with those of a craniopharyngioma studied in the same way. The patient was a 26-year-old woman presenting with headache, chiasmatic syndrome, and hypopituitarism. A cyst containing a mural nodule was partially removed and an Ommaya reservoir placed in the operative site for further treatment. The cyst wall was composed of connective tissue and three kinds of epithelial cells: non-ciliated squamous, ciliated columnar, and mucous-secreting cells. The morphology of these cells in vitro was similar to prickle cells seen in craniopharyngioma and the epidermis. It is concluded that both Rathke's left cyst and craniopharyngioma originate in remnants of Rathke's pouch, but at times may show some histological differences.

A light and electron microscopic and immunohistochemical study of human arachnoid villi

1988 ◽  
Vol 69 (3) ◽  
pp. 429-435 ◽  
Author(s):  
Shinya Kida ◽  
Tetsumori Yamashima ◽  
Toshihiko Kubota ◽  
Haruhide Ito ◽  
Shinjiro Yamamoto
Keyword(s):  
Electron Microscopy ◽  
Intermediate Filaments ◽  
Cell Layer ◽  
Light And Electron Microscopy ◽  
Central Core ◽  
Fibrous Capsule ◽  
Electron Microscopic ◽  
Content Type ◽  
Arachnoid Villi ◽  
Arachnoid Cell

✓ The structure of human arachnoid villi was investigated by light and electron microscopy with the aid of immunohistochemical techniques. The human arachnoid villi examined were basically composed of four portions: a fibrous capsule, an arachnoid cell layer, a cap cell cluster, and a central core. The arachnoid cell layer encompassing the central core was mostly covered by the thin fibrous capsule with an endothelial investment. However, the fibrous capsule was often absent at the apical portion of the villus and a factor VIII-related antigen stain failed to confirm the investment of endothelial cells. Instead, the arachnoid cell layer abutted directly upon the lumen of a lateral lacuna or the sinus. The arachnoid cell layer was thickened in places, forming cap cell clusters; it usually consisted of outer and inner zones. On vimentin staining, the former was slightly positive while the latter was strongly positive. The central core contained a network of arachnoid cells intermingled with connective tissue fibers and was in continuity with the cranial subarachnoid space. Electron microscopy showed that the arachnoid cells contained a larger number of intermediate filaments in the inner zone than the outer zone. Ultrastructural immunohistochemical localization showed that vimentin was localized at the intermediate filaments and desmosomal plaques of the arachnoid cells. The arachnoid cells showed a marked variety in both the cell forms and the number of intermediate filaments or desmosomes, depending on their location.

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).

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.

Sign in / Sign up

Export Citation Format

Share Document