Progression of partial experimental injury to peripheral nerve

1975 ◽  
Vol 42 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Alan R. Hudson ◽  
David G. Kline
Keyword(s):  
Recovery Of Function ◽  
Electron Microscopic Examination ◽  
Ground Substance ◽  
Electron Microscopic ◽  
Early Recovery ◽  
Content Type ◽  
Proximal Stimulus ◽  
Late Recovery ◽  
Fine Print ◽  
Experimental Injury

✓ Biopsies from partially lacerated nerves were taken at the sites of proximal stimulus, laceration, and distal recording, and from stimuli and recording sites of control nerves. Electron microscopic examination of the partially lacerated major fasciculus revealed three zones of injury. The laceration zone showed neurotemetic changes, the adjacent or intermediate zone, partial degeneration, and the zone most peripheral to the laceration, changes in ground substance. Progression of the original injury is apparently due to ongoing changes in the intermediate and peripheral zones while much of the relative early recovery is due to reversal of changes in these zones. Regeneration through the laceration or neurotemetic zone is limited but does account for a small amount of late recovery of function.

Ultrastructural morphology of the olfactory pathway for cerebrospinal fluid drainage in the rabbit

1986 ◽  
Vol 64 (3) ◽  
pp. 466-473 ◽  
Author(s):  
Stephanie S. Erlich ◽  
J. Gordon McComb ◽  
Shigeyo Hyman ◽  
Martin H. Weiss
Keyword(s):  
Cerebrospinal Fluid ◽  
Connective Tissue ◽  
Electron Microscopic Examination ◽  
Olfactory Pathway ◽  
Electron Microscopic ◽  
En Bloc ◽  
Major Pathway ◽  
Content Type ◽  
Csf Drainage ◽  
Fine Print

✓ Previous physiological studies indicate that the olfactory region serves as a major pathway for cerebrospinal fluid (CSF) drainage into the lymphatic system. The present study was undertaken to determine the ultrastructural characteristics of this egress route. New Zealand White rabbits received a single bolus injection of the tracer ferritin (MW 400,000) into both lateral ventricles in such a manner as not to raise the intraventricular pressure above the normal level. The animals were sacrificed via intracardiac perfusion of fixative between less than 12 minutes and 4 hours following injection. The cribriform region was removed en bloc, decalcified, sectioned coronally, and prepared for light and electron microscopic examination. The arachnoid, dura, and periosteum surrounding the fila olfactoria passing through the cribriform plate merge together and form the perineurium, which consists of multiple layers of loosely overlapping cells with widely separated junctions and few vesicles. The perineurium surrounding the olfactory filaments at the superficial submucosal level is only one cell thick. The subarachnoid space freely communicates with the perineural space surrounding each filament. No morphological barrier between the perineural space and the loose submucosal connective tissue was identified. Whether or not the perineurium was multi- or singlelayered, ferritin was noted in abundance between the loosely overlapping perineural cells and in the submucosal connective tissue. The distribution of ferritin at 12 minutes was similar to that at 4 hours; however, the quantity of ferritin was increased at 4 hours. These results indicate that no significant barrier to CSF drainage is present at the rabbit cribriform region and that CSF reaches the submucosal region rapidly via open pathways.

Morphological study of clinically nonsecreting pituitary adenomas in patients under 40 years of age

1991 ◽  
Vol 75 (6) ◽  
pp. 902-905 ◽  
Author(s):  
Shozo Yamada ◽  
Kalman Kovacs ◽  
Eva Horvath ◽  
Tadashi Aiba
Keyword(s):  
Microscopic Examination ◽  
Pituitary Adenomas ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Null Cell ◽  
Younger Patients ◽  
Content Type ◽  
Morphological Studies ◽  
Null Cell Adenomas ◽  
Fine Print

✓ Clinically nonsecreting pituitary adenomas removed at surgery from 69 patients under 40 years of age were studied by histological, immunocytochemical, and transmission electron microscopic examination. By morphological analysis. 19 tumors were found to be null-cell adenomas. 17 silent gonadotroph adenomas, 14 silent subtype 3 adenomas of unknown cellular origin, 13 silent subtype 1 or subtype 2 corticotroph adenomas, three oncocytomas, and three silent thyrotroph adenomas. These results indicate that the incidence of null-cell adenomas and oncocytomas, which are known to be the most common types of nonsecreting pituitary adenomas in patients over 40 years of age, is relatively low in younger patients. This trend is even more obvious in patients younger than 30 years of age. It can be concluded that clinically nonsecreting pituitary adenomas represent a heterogeneous group morphologically, and that the incidence of the different tumor types varies depending on the patient's age. These findings underline the importance of careful morphological studies. It is proposed that, in order for the correct morphological diagnosis to be made, tumors removed surgically from patients with clinically nonsecreting pituitary adenomas (especially younger patients) should be investigated not only by histological means but also by immunocytochemical and electron microscopic examination. The information obtained from such analysis may be useful in assessing prognosis and deciding on the appropriate treatment.

Dobutamine responsiveness, PET mismatch, and lack of necrosis in low-flow ischemia: is this hibernation in the isolated rat heart?

2003 ◽  
Vol 285 (1) ◽  
pp. H316-H324 ◽  
Author(s):  
Richard Southworth ◽  
Pamela B. Garlick
Keyword(s):  
Rat Heart ◽  
Recovery Of Function ◽  
Electron Microscopic Examination ◽  
Left Ventricular ◽  
Isolated Rat Heart ◽  
Low Flow ◽  
Hibernating Myocardium ◽  
Heart Model ◽  
Electron Microscopic ◽  
Isolated Rat

The clinical hallmarks of hibernating myocardium include hypocontractility while retaining an inotropic reserve (using dobutamine echocardiography), having normal or increased [18F]fluoro-2-deoxyglucose-6-phosphate (18FDG6P) accumulation associated with decreased coronary flow [flow-metabolism mismatch by positron emission tomography (PET)], and recovering completely postrevascularization. In this study, we investigated an isolated rat heart model of hibernation using experimental equivalents of these clinical techniques. Rat hearts ( n = 5 hearts/group) were perfused with Krebs-Henseleit buffer for 40 min at 100% flow and 3 h at 10% flow and reperfused at 100% flow for 30 min (paced at 300 beats/min throughout). Left ventricular developed pressure fell to 30 ± 8% during 10% flow and recovered to 90 ± 7% after reperfusion. In an additional group, this recovery of function was found to be preserved over 2 h of reperfusion. Electron microscopic examination of hearts fixed at the end of the hibernation period demonstrated a lack of ischemic injury and an accumulation of glycogen granules, a phenomenon observed clinically. In a further group, hearts were challenged with dobutamine during the low-flow period. Hearts demonstrated an inotropic reserve at the expense of increased lactate leakage, with no appreciable creatine kinase release. PET studies used the same basic protocol in both dual- and globally perfused hearts (with 250MBq18FDG in Krebs buffer ± 0.4 mmol/l oleate). PET data showed flow-metabolism “mismatch;” whether regional or global,18FDG6P accumulation in ischemic tissue was the same as (glucose only) or significantly higher than (glucose + oleate) control tissue (0.023 ± 0.002 vs. 0.011 ± 0.002 normalized counts · s-1· g-1· min-1, P < 0.05) despite receiving 10% of the flow. This isolated rat heart model of acute hibernation exhibits many of the same characteristics demonstrated clinically in hibernating myocardium.

The deposition of Hg203-chlormerodrin in experimental brain tumors

1971 ◽  
Vol 35 (3) ◽  
pp. 303-308 ◽  
Author(s):  
Tatsuya Kobayashi ◽  
Louis Bakay ◽  
Joseph C. Lee
Keyword(s):  
Brain Tumors ◽  
Tumor Cells ◽  
Normal Brain ◽  
Intracranial Tumors ◽  
Electron Microscopic ◽  
Electron Microscopic Autoradiography ◽  
Content Type ◽  
Meningeal Tumors ◽  
Vacuolar System ◽  
Fine Print

✓ The deposition of Hg203-chlormerodrin was studied in intracranial tumors in mice induced by implantation of 20-methyl cholanthrene by tissue assay, as well as light microscopic and electron microscopic autoradiography. The investigations were carried out in astrocytomas, glioblastomas, and meningeal tumors. The chlormerodrin content of the tumors exceeded that of normal brain with a significant tumor/brain ratio ranging from 5.8 to 22.5. It was found that the chlormerodrin molecule becomes rapidly incorporated in the tumor cells, with a preference for that portion of the cytoplasm associated with the vacuolar system.

Ultrastructure of the human posttraumatic syrinx

1989 ◽  
Vol 71 (2) ◽  
pp. 239-243 ◽  
Author(s):  
Kesava K. V. Reddy ◽  
Marc R. Del Bigio ◽  
Garnette R. Sutherland
Keyword(s):  
Central Canal ◽  
Ependymal Cells ◽  
Electron Microscopic ◽  
Content Type ◽  
Microscopic Features ◽  
Cell Processes ◽  
Ultrastructural Appearance ◽  
Posttraumatic Syringomyelia ◽  
Communicating Syringomyelia ◽  
Fine Print

✓ Although posttraumatic syringomyelia is a well-established clinicopathological entity, there is a paucity of information on the ultrastructural features of this condition. This study documents the light and electron microscopic features of posttraumatic syringes obtained from two patients who underwent surgical cordectomy. The syringes were lined largely by cell processes of astrocytes. Small regions near the caudal end were lined by flattened ependymal cells that lacked surface specializations. These were thought to represent remnants of the central canal ependyma. The ultrastructural appearance of the syrinx was similar to that of the communicating syringomyelia as well as the periventricular changes that accompany hydrocephalus. The authors conclude that the changes represent the nonspecific sequelae of a distensile force within the syrinx cavity.

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.

Multiple supratentorial hemangioblastomas

1971 ◽  
Vol 35 (4) ◽  
pp. 396-405 ◽  
Author(s):  
Shakuntla Ishwar ◽  
Raymond M. Taniguchi ◽  
F. Stephen Vogel
Keyword(s):  
Secretory Granules ◽  
Electron Microscopic Examination ◽  
Extramedullary Hematopoiesis ◽  
Electron Microscopic ◽  
Content Type ◽  
Parietal Area ◽  
Erythropoietin Production ◽  
Well Differentiated ◽  
The Right ◽  
Mass Lesions

✓ Multiple hemangioblastomas were found above the tentorium in a 62-year-old woman who first had a discrete 2.5 cm tumor removed from the superior aspect of the tentorium adjacent to the falx, and 2 years later developed two more intracranial mass lesions, one in the right parietal area, the other attached to the dura of the right frontal fossa. Histological examination of all three tumors showed precisely the same well-differentiated morphology of hemangioblastoma. Foci of extramedullary hematopoiesis were present within them. Electron microscopic examination of the last two lesions disclosed secretory granules within the tumor cells, indicative of erythropoietin production, as described previously in a hemangioblastoma. Collagen and endothelial cells were not present in quantities consistent with an angioblastic meningioma. The genesis of hemangioblastomas is discussed.

Pineoblastoma with an unusually long survival

1988 ◽  
Vol 69 (2) ◽  
pp. 287-291 ◽  
Author(s):  
Yuji Uematsu ◽  
Toru Itakura ◽  
Seiji Hayashi ◽  
Norihiko Komai
Keyword(s):  
Cell Differentiation ◽  
Electron Microscopic ◽  
Content Type ◽  
Long Survival ◽  
Microscopic Studies ◽  
Stereotaxic Biopsy ◽  
Autopsy Specimens ◽  
Shunting Procedure ◽  
Fine Print

✓ The authors report a case of pineoblastoma with a 9-year follow-up period after stereotaxic biopsy, a shunting procedure, and radiotherapy. Light and electron microscopic studies of biopsy and autopsy specimens revealed no cell differentiation of the pineoblastoma. The possible factors predisposing to long survival are discussed in comparison with the course in patients with medulloblastoma.

Clinical and histopathological characteristics of gonadotropin-producing pituitary adenomas

1985 ◽  
Vol 62 (3) ◽  
pp. 376-382 ◽  
Author(s):  
Masaki Miura ◽  
Yasuhiko Matsukado ◽  
Takafumi Kodama ◽  
Yohsuke Mihara
Keyword(s):  
Cell Culture ◽  
Culture Medium ◽  
Definitive Diagnosis ◽  
Immunoperoxidase Staining ◽  
Cell Culture Medium ◽  
Electron Microscopic ◽  
Content Type ◽  
Lh Rh ◽  
Hormonal Assay ◽  
Fine Print

✓ The clinical and histopathological characteristics in six cases of gonadotropin-producing adenoma are presented. Definitive diagnosis was made by the determination of gonadotropin levels in culture medium. Several authors have reported that gonadotropin-producing adenomas are very rare; however, hormonal assay of adenoma cell culture medium may indicate the real incidence of gonadotropin-producing adenomas to be greater than is thought. In reported cases, practically no endocrinological symptoms have been found suggesting increased gonadotropin levels, and basal values of plasma gonadotropins have been reported as only slightly over the normal range. Gonadotropin-producing adenomas may have been misdiagnosed as nonsecreting adenomas. The clinical characteristics of gonadotropin-producing adenomas can be summarized as follows: 1) a tendency for more rapid growth than nonsecreting adenomas; 2) prominent suprasellar extension with marked enhancement on computerized tomography; and 3) diminished response of luteinizing hormone (LH) alone in response to LH-releasing hormone (LH-RH) stimulation, and the ratio of peak follicle-stimulating hormone to peak LH in the LH-RH stimulation test is more frequently over 1:1 in cases of gonadotropin-producing adenoma than in cases of nonsecreting adenoma and craniopharyngioma. Immunoperoxidase staining revealed two kinds of adenoma cells, one intensely and the other faintly stained. Abundant mitochondria and few secretory granules were characteristic electron microscopic features. Oncocytic transformation of adenoma cells was suggested by immunoperoxidase staining and the electron microscopic appearance, and may suppress the elevation of circulating plasma gonadotropin levels. Thus, hormonal assay of adenoma cell culture medium and immunoperoxidase staining are essential for definitive diagnosis of gonadotropin-producing adenomas.

The effect of a lipid hydroperoxide of arachidonic acid on the canine basilar artery

1981 ◽  
Vol 54 (3) ◽  
pp. 357-365 ◽  
Author(s):  
Tomio Sasaki ◽  
Susumu Wakai ◽  
Takao Asano ◽  
Takashi Watanabe ◽  
Takaaki Kirino ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Basilar Artery ◽  
Morphological Changes ◽  
Degenerative Change ◽  
Lipid Hydroperoxide ◽  
Second Phase ◽  
Electron Microscopic ◽  
Content Type ◽  
Fine Print

✓ The in vivo spasmogenic capacity of a lipid hydroperoxide (15-hydroperoxy arachidonic acid: 15-HPAA) was studied in a chronic experiment using the dog. The 15-HPAA was injected into the cisterna magna (0.2 or 2 mg emulsified in bovine serum albumin solution). The changes in diameter of the basilar artery were followed by angiography, and the morphological changes were studied by electron microscopy. The cisternal injection of 0.2 mg of 15-HPAA caused a mild constriction of the basilar artery which lasted about 7 hours. The cisternal injection of 2 mg of 15-HPAA caused a biphasic constriction, the initial phase of which was a moderate narrowing lasting about 10 hours. The second phase started on the 2nd or the 3rd day after injection. The intensity of the arterial narrowing was more pronounced in the second phase than in the first. The prolonged secondary constriction of the basilar artery continued until sacrifice on the 7th day after injection. Electron microscopic study revealed a marked degenerative change in the endothelium and myonecrotic changes in the tunica media. The prolonged arterial constriction in the second phase was invariably associated with remarkable degeneration of the endothelium. On the other hand, myonecrotic changes were limited to a small number of smooth-muscle cells. The results of the present study are consonant with the hypothesis that lipid peroxidation associated with lysis of the subarachnoid clot is involved in the genesis of chronic vasospasm in subarachnoid hemorrhage.

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