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.

Ovine pericardium as a new material for duraplasty

1996 ◽  
Vol 84 (3) ◽  
pp. 508-513 ◽  
Author(s):  
Jan Pařízek ◽  
Zdeněk Husěk ◽  
Pavel Měřička ◽  
Josef Téra ◽  
Stanislav Němeček ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Host Tissue ◽  
Γ Irradiation ◽  
Content Type ◽  
Dural Substitute ◽  
Freeze Dried ◽  
New Material ◽  
Fine Print ◽  
Scanning Electron

✓ The authors report on their 2 1/2-year clinical experience using a dural substitute, ovine pericardium, stabilized with 0.3% glutaraldehyde, flat freeze-dried, and sterilized with γ-irradiation. Packaging of the ovine pericardium in double-plastic transparent bags allows simple storage in operating rooms and the opportunity for the surgeon to choose an ideal graft according to its shape, size, and plasticity. The ovine pericardia were examined histologically and by transmission and scanning electron microscopy in their native, freeze-dried, and irradiated forms. The final product is composed solely of pericardium fibrosum interwoven with artificially formed extracellular microcavities that serve as natural pores for the ingrowth of host tissue. The surfaces of the grafts appear smooth on the inner and rough on the outer sides. Sixteen grafts were examined macroscopically at autopsy and four of these were also examined histologically to illustrate their successful healing with no adhesion to the underlying brain. As a new dural substitute, ovine pericardium proved to be superior to bovine and allogeneic pericardia because of its workability, flexibility, and reduced thickness. In a study of 120 grafts, all but one healed without complications.

Clinical application of a physically and chemically processed human substitute for dura mater

2003 ◽  
Vol 98 (6) ◽  
pp. 1198-1202 ◽  
Author(s):  
Denis Dufrane ◽  
Christophe Marchal ◽  
Olivier Cornu ◽  
Christian Raftopoulos ◽  
Christian Delloye
Keyword(s):  
Dura Mater ◽  
Hematological Parameters ◽  
Magnetic Resonance Images ◽  
Fascia Lata ◽  
Neurosurgical Procedures ◽  
Content Type ◽  
Inflammatory Reactions ◽  
Freeze Dried ◽  
Dural Graft ◽  
Fine Print

Object. Allogenic human fascia lata used in neurosurgery as a dura mater substitute can be associated with the risk of virus and bacterium transmission and with a delay in its incorporation due to immunological and inflammatory reactions. The authors review their preliminary experience with a chemically and physically processed fascia lata graft. Methods. Grafts that had been treated with solvent detergents, freeze-dried for conservation, and gamma irradiated (25,000 Gy) for sterilization were placed into 17 patients during neurosurgical procedures performed to treat brain tumors, cerebral malformations, trigeminal neuralgia, and posttraumatic lesions. The handling properties of the material, surgical wound features, and hematological parameters were evaluated. The average follow-up period was 23.8 ± 2.2 months (mean ± standard deviation). The handling properties and biocompatibility of these human dural substitutes were highly satisfactory and no major complications were observed. Postoperative computerized tomography or magnetic resonance images obtained in 13 patients revealed no abnormal findings at the site of fascia lata implantation. In one patient who underwent a second surgery performed 12 months after the initial operation, this dural substitute was found to have been recolonized by host fibroblastic cells and replaced by autologous collagenous tissue. Conclusions. Human fascia lata that has been rendered safe by applying physical and chemical treatment is a fully biocompatible alternative to the dural graft materials currently available.

Clinical application of a new bioabsorbable artificial dura mater

2002 ◽  
Vol 96 (4) ◽  
pp. 731-735 ◽  
Author(s):  
Keisuke Yamada ◽  
Susumu Miyamoto ◽  
Motohiro Takayama ◽  
Izumi Nagata ◽  
Nobuo Hashimoto ◽  
...  
Keyword(s):  
Dura Mater ◽  
Latent Infection ◽  
Neurosurgical Procedures ◽  
Resonance Imaging ◽  
Content Type ◽  
Dural Substitute ◽  
Collagenous Tissue ◽  
Foreign Body Reactions ◽  
Fine Print

Object. In their pursuit of a better substitute for dura mater in neurosurgical procedures, the authors review their experience with GM972. Methods. A newly developed synthetic dural substitute composed of bioabsorbable polymers (GM972) was placed in 53 patients during neurosurgical procedures. The handling properties of the material, surgical wound features, and findings of hematological, computerized tomography, and/or magnetic resonance imaging examinations were evaluated. The average follow-up period was 35.5 months. The handling properties and biocompatibility of this new dural substitute were highly satisfactory, and no significant complication was observed. In patients who underwent a second surgery performed more than 18 months after the initial operation, this new dural substitute was found to have been replaced by autologous collagenous tissue. Because of its bioabsorbability, chronic foreign body reactions to this synthetic dural substitute were negligible. Conclusions. In this report the authors support the effectiveness and safety of this bioabsorbable artificial dural substitute that provides a reduced risk of transmission of latent infection.

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.

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.

Application of shock waves as a treatment modality in the vicinity of the brain and skull

2003 ◽  
Vol 99 (1) ◽  
pp. 156-162 ◽  
Author(s):  
Atsuhiro Nakagawa ◽  
Yasuko Kusaka ◽  
Takayuki Hirano ◽  
Tsutomu Saito ◽  
Reizo Shirane ◽  
...  
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Dura Mater ◽  
Treatment Modality ◽  
Ho:Yag Laser ◽  
Content Type ◽  
Dural Substitute ◽  
Wave Generator ◽  
The Brain ◽  
Fine Print

Object. Shock waves have not previously been used as a treatment modality for lesions in the brain and skull because of the lack of a suitable shock wave source and concerns about safety. Therefore, the authors have performed experiments aimed at developing both a new, compact shock wave generator with a holmium:yttrium-aluminum-garnet (Ho:YAG) laser and a safe method for exposing the surface of the brain to these shock waves. Methods. Twenty male Sprague—Dawley rats were used in this study. In 10 rats, a single shock wave was delivered directly to the brain, whereas the protective effect of inserting a 0.7-mm-thick expanded polytetrafluoroethylene (ePTFE) dural substitute between the dura mater and skull before applying the shock wave was investigated in the other 10 rats. Visualizations on shadowgraphy along with pressure measurements were obtained to confirm that the shock wave generator was capable of conveying waves in a limited volume without harmful effects to the target. The attenuation rates of shock waves administered through a 0.7-mm-thick ePTFE dural substitute and a surgical cottonoid were measured to determine which of these materials was suitable for avoiding propagation of the shock wave beyond the target. Conclusions. Using the shock wave generator with the Ho:YAG laser, a localized shock wave (with a maximum overpressure of 50 bar) can be generated from a small device (external diameter 15 mm, weight 20 g). The placement of a 0.7-mm-thick ePTFE dural substitute over the dura mater reduces the overpressure of the shock wave by 96% and eliminates damage to surrounding tissue in the rat brain. These findings indicate possibilities for applying shock waves in various neurosurgical treatments such as cranioplasty, local drug delivery, embolysis, and pain management.

A new rat model of chronic cerebral hypoperfusion associated with arteriovenous malformations

2002 ◽  
Vol 97 (5) ◽  
pp. 1198-1202 ◽  
Author(s):  
Jian Hai ◽  
Meixiu Ding ◽  
Zhilin Guo ◽  
Bingyu Wang
Keyword(s):  
Electron Microscopy ◽  
Animal Model ◽  
Arteriovenous Malformations ◽  
Perfusion Pressure ◽  
Chronic Cerebral Hypoperfusion ◽  
Cerebral Hypoperfusion ◽  
Model Group ◽  
Content Type ◽  
The Right ◽  
Fine Print

Object. A new experimental model of chronic cerebral hypoperfusion was developed to study the effects of systemic arterial shunting and obstruction of the primary vessel that drains intracranial venous blood on cerebral perfusion pressure (CPP), as well as cerebral pathological changes during restoration of normal perfusion pressure. Methods. Twenty-four Sprague—Dawley rats were randomly assigned to either a sham-operated group, an arteriovenous fistula (AVF) group, or a model group (eight rats each). The animal model was readied by creating a fistula through an end-to-side anastomosis between the right distal external jugular vein (EJV) and the ispilateral common carotid artery (CCA), followed by ligation of the left vein draining the transverse sinus and bilateral external carotid arteries. Systemic mean arterial pressure (MAP), draining vein pressure (DVP), and CPP were monitored and compared among the three groups preoperatively, immediately postoperatively, and again 90 days later. Following occlusion of the fistula after a 90-day interval, blood—brain barrier (BBB) disruption and water content in the right cortical tissues of the middle cerebral artery territory were confirmed and also quantified with transmission electron microscopy. Formation of a fistula resulted in significant decreases in MAP and CPP, and a significant increase in DVP in the AVF and model groups. Ninety days later, there were still significant increases in DVP and decreases in CPP in the model group compared with the other groups (p < 0.05). Damage to the BBB and brain edema were noted in animals in the model group during restoration of normal perfusion pressure by occlusion of the fistula. Electron microscopy studies revealed cerebral vasogenic edema and/or hemorrhage in various amounts, which correlated with absent astrocytic foot processes surrounding some cerebral capillaries. Conclusions. The results demonstrated that an end-to-side anastomosis between the distal EJV and CCA can induce a decrease in CPP, whereas a further chronic state of cerebral hypoperfusion may be caused by venous outflow restriction, which is associated with perfusion pressure breakthrough. This animal model conforms to the basic hemodynamic characteristics of human cerebral arteriovenous malformations.

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.

A light and electron microscopic study of ectopic tendon and ligament formation induced by bone morphogenetic protein—13 adenoviral gene therapy

2001 ◽  
Vol 95 (2) ◽  
pp. 298-307 ◽  
Author(s):  
Gregory A. Helm ◽  
Jin Zhong Li ◽  
Tord D. Alden ◽  
Sarah B. Hudson ◽  
Elisa J. Beres ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Skeletal Development ◽  
Light And Electron Microscopy ◽  
Mesenchymal Cell ◽  
Ultrastructural Changes ◽  
Endochondral Bone Formation ◽  
Electron Microscopic ◽  
Content Type ◽  
Time Points ◽  
Fine Print

Object. Bone morphogenetic proteins (BMPs) are involved in the growth and development of many tissues, but it is their role in skeletal development and their unique ability to induce ectopic and orthotopic osteogenesis that have attracted the greatest interest. Expression of the BMP-13 gene is predominantly localized to hypertrophic chondrocytes in regions of endochondral bone formation during development, as well as in mature articular cartilage in the adult. In addition, the application of BMP-13 on a collagen carrier induces neotendon/neoligament formation when delivered subcutaneously or intramuscularly in rodents. The aim of the present study was to determine the histological and ultrastructural changes that occur after the intramuscular injection of a first-generation BMP-13 adenoviral vector. Methods. Athymic nude rats were injected with 3.75 × 1010 plaque-forming units of adenovirus (Ad)-BMP-13 or Ad-β-galactosidase in the thigh musculature, and the region was examined using light and electron microscopy at various time points between 2 days and 100 days postinjection. As early as 2 days after injection of Ad-BMP-13, progenitor cells were observed infiltrating between the transduced muscle fibers. These cells subsequently proliferated, differentiated, and secreted large amounts of collagenous extracellular matrix. By 100 days postinjection, the treated tissue displayed the histological and ultrastructural appearance of neotendon/neoligament, which was clearly demarcated from the surrounding muscle. Small foci of bone and fibrocartilage were also seen within the treated tissue. A short-term bromodeoxyuridine study also demonstrated rapid mesenchymal cell proliferation at the Ad-BMP-13 injection site as early as 48 hours postinjection. At all time points, the control AD-β-gal injection sites were found to contain only normal muscle, without evidence of inflammation or mesenchymal cell proliferation. Conclusions. The results of this study indicate that in the future the use of the BMP-13 gene may have therapeutic utility for the healing of tendon and ligament tears and avulsion injuries.

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