The author measured the severity of brain damage of 36 rabbits irradiated 2.45 GHz microwave for 10 minutes, 20 minutes and 30 minutes, respectively. Electromicroscopic and light microscopic findings of just after, 1 weeks, 2 weeks and 4 weeks after irradiated brain were compared in each time. Swelling and vacualization of nerve cell and mitochondria were noted. Also these changes tend to increased severity along amount of radiation, but revealed reversible changes with time. Myelinated and unmyelinated nerve fibers were examined as same manner. These nerve fibers also revealed swelling and vascuolization, these findings also tend to increase severity with irradiation power and more prominent at unmyelinated nerve fibers. Reversability of these findings after each time period were more prominent in myelinated nerve fibers than unmyelinated nerve fibers.
Brain ; Cerebrum* ; Microwaves* ; Mitochondria ; Myelin Sheath ; Nerve Fibers ; Nerve Fibers, Myelinated ; Nerve Fibers, Unmyelinated ; Neurons ; Rabbits*

Toxic effects of Aconiti tuber, an important ingredient of Chinese medicinal preparation, have been encountered clinically. The chief bioactive and toxic constituent is the alkaloid aconitine. In this study histopathologic changes in the fine structures of rabbit eye by intravenously administered aconitine were examined with light and electron microscopes. The initial and most characteristic features observed in the histopathologic study were degenerative changes in the myelinated nerve fiber layer. So the effects of aconitine on the rabbit eye were primarily regarded as toxic neuropathy.
Aconitine* ; Asian Continental Ancestry Group ; Humans ; Nerve Fibers, Myelinated

Congenital fibrosis of the extraocular muscle is characterized by the replacement of normal contractile muscles by fibrous tissue in varying degrees. Therefore, the clinical manifestation is dependent upon the degree of fibrous involvement. Brown reported 3 cases of the severe form of congenital fibrosis under the title of "General fibrosis syndrome". It has been known that the inferior rectus muscles are usually most prone to maximal involvement, which causes the eye to assume a hypotropic position with a chin elevation. We experienced two cases of congenital fibrosis of the extraocular muscles; one was a mild form with monocular involvement, and the other was a severe form with absence of all extraocular movement in the both eyes. In the latter, the histopathological examination of the excised tissue by light microscopy revealed that the inferior rectus muscle had a partly degeneration of some muscle fibers, as well as connective tissue proliferation. The lateral rectus muscle was replaced by fibrous tissue and fat cell. We discussed the clinical and histopathological features in the congenital fibrosis of the extraocular muscles.
Adipocytes ; Chin ; Connective Tissue ; Fibrosis* ; Microscopy ; Muscles ; Nerve Fibers, Myelinated

Nimodipine the potent, centrally active, clacium channel blocker, is known to increase cerebral and spinal blood flow. In the present study, the authors investigated the effect on Nimodipine on injured spinal cord. The experiment was a randomized blind study in which four groups of five cats received Nimodipine(0.05mg/kg) intravenously, and control groups of five cats received only Diluent. As a step in the investigation of the possible effect of spinal cord trauma on biochemical and ultrastructural changes in the injured cord, activities of lipid peroxidation were measured in the frozened-dried sample of the spinal cord and fine structure of the mylinated nerve fiber in the white matter were observed. An increase of lipid peroxidation level was found as early as 1 hour after the injury and the highest concentration was reached at 5 hours after the injury(P<0.01). Fine structures of the myelinated nerve fibers were changed progressively with the lapse of time after the injury. The effect of Nimodipine on lipid peroxidation and fine ultrastructural changes of myelinated nerve fibers were studied, and the result of this study revealed that Nimodipine groups showed a lower level of lipid peroxidation with statistical significance(P<0.05) and preservation of ultrastructural myelinated nerve fiber was prominent.
Animals ; Cats ; Lipid Peroxidation ; Nerve Fibers ; Nerve Fibers, Myelinated ; Nimodipine* ; Spinal Cord Injuries* ; Spinal Cord*

Sihler's staining allows visualization of the nerve distribution within soft tissues without extensive dissection and does not require slide preparation, unlike traditional approaches. This technique can be applied to the mucosa, muscle, and organs that contain myelinated nerve fibers. In particular, Sihler's technique may be considered the best tool for observing nerve distribution within skeletal muscles. The intramuscular distribution pattern of nerves is difficult to observe through manual manipulation due to the gradual tapering of nerves toward the terminal end of muscles, so it should be accompanied by histological studies to establish the finer branches therein. This method provides useful information not only for anatomists but also for physiologists and clinicians. Advanced knowledge of the nerve distribution patterns will be useful for developing guidelines for clinicians who perform operations such as muscle resection, tendon transplantation, and botulinum toxin injection. Furthermore, it is a useful technique to develop neurosurgical techniques and perform electrophysiological experiments. In this review, Sihler's staining technique is described in detail, covering its history, staining protocol, advantages, disadvantages, and possible applications. The application of this technique for determining the arterial distribution pattern is also described additionally in this study.
Anatomists ; Arteries ; Botulinum Toxins ; Humans ; Mucous Membrane ; Muscle, Skeletal ; Muscles ; Nerve Fibers, Myelinated ; Tendons ; Transplants

PURPOSE: We evaluated the ocular findings associated with peripapillary myelinated nerve fibers of 3 clock hours or more in 15 patients. METHODS: Ophthalmologic examination was performed in 15 patients with peripapillary myelinated nerve fibers of 3 clock hours or more. Twelve younger patients who wanted occlusion therapy were enrolled into a therapeutic trial with spectacle correction and occlusion for amblyopia. RESULTS: Thirteen out of the 15 patients presented with varying degrees of anisomyopia and amblyopia. The final visual acuities of the 12 younger patients with spectacle correction and occlusion for amblyopia were 0.5 or better in 5, between 0.1 and 0.5 in 4, and worse than 0.1 in 3. Two patients showed no ocular abnormalities except negligible refractive errors. Five out of 13 patients with amblyopia showed constant exotropia and one showed intermittent exotropia in the eyes with myelinated nerve fibers. CONCLUSIONS: Most of the patients with peripapillary myelinated nerve fibers of 3 clock hours or more showed anisomyopia and amblyopia. As some patients responded to spectacle correction and occlusion therapy for amblyopia, aggressive amblyopia therapy should be considered even in patients with myelinated nerve fibers.
Amblyopia ; Exotropia ; Humans ; Myelin Sheath* ; Nerve Fibers, Myelinated* ; Refractive Errors ; Visual Acuity

STATEMENT OF PROBLEM: According to the fracture pattern in several reports, fractures most frequently occur in the interface between the ceromer and the substructure. PURPOSE: The aim of this in vitro study was to compare the macro shear bond strength and microshear bond strength of a ceromer bonded to a fiber reinforced composite (FRC) as well as metal alloys. MATERIAL AND METHODS: Ten of the following substructures, type II gold alloy, Co-Cr alloy, Ni-Cr alloy, and FRC (Vectris) substructures with a 12 mm in diameter, were imbedded in acrylic resin and ground with 400, and 1, 000-grit sandpaper. The metal primer and wetting agent were applied to the sandblasted bonding area of the metal specimens and the FRC specimens, respectively. The ceromer was placed onto a 6 mm diameter and 3 mm height mold in the macro-shear test and 1 mm diameter and 2 mm height mold in the micro-shear test, and then polymerized. The macro- and micro-shear bond strength were measured using a universal testing machine and a micro-shear tester, respectively. The macro- and micro-shear strength were analyzed with ANOVA and a post-hoc Scheffe adjustment (alpha= .05). The fracture surfaces of the crowns were then examined by scanning electron microscopy to determine the mode of failure. Chi-square test was used to identify the differences in the failure mode. RESULTS: The macro-shear strength and the micro-shear strength differed significantly with the types of substructure (P< .001). Although the ceromer/FRC group showed the highest macro and micro-shear strength, the micro-shear strength was not significantly different from that of the base metal alloy groups. The base metal alloy substructure groups showed the lowest mean macro-shear strength. However, the gold alloy substructure group exhibited the least micro-shear strength. The micro-shear strength was higher than the macro-shear strength excluding the gold alloy substructure group. Adhesive failure was most frequent type of fracture in the ceromer specimens bonded to the gold alloys. Cohesive failure at the ceromer layer was more common in the base metals and FRC substructures. CONCLUSION: The Vectris substructure had higher shear strength than the other substructures. Although the shear strength of the ceromer bonded to the base metals was lower than that of the gold alloy, the micro-shear strength of the base metals were superior to that of the gold alloy.
Adhesives ; Alloys* ; Crowns ; Fungi ; Gold Alloys ; Metals ; Microscopy, Electron, Scanning ; Nerve Fibers, Myelinated ; Polymers ; Shear Strength

We would like to introduce endoscope assisted ophthalmic microsurgery. The endoscope system is made of endoscope body, colored moniter, handpiece. The handpiece consists of a 19G or 20G probe housing a fiber optic cable for the camera of a 380.000 pixel resolution, a fiber optic cable for a xenon light source and a working channel. The endoscope was useful to visualize the areas, such as the peripheral retina, posterior side of iris, that were not readily seen by conventional nor wide angle viewing techniques without indentation. Also it gave us good results in the hard visual field cases of corneal opacification or during fluid-gas exchange. using the endoscope permitted the vitreous base to be accurately observed and managed surgically through good visualization of peripheral retina. Intraocular procedure such as vitrectomy, subretinal fluid drainge, endophotocoahulation was performed easily under the endoscopic view, With the improvement of resolution power of the endoscope and the development of stereovision, the range of clinical usage of this technique will be expanded.
Endoscopes* ; Housing ; Iris ; Microsurgery* ; Nerve Fibers, Myelinated ; Retina ; Subretinal Fluid ; Visual Fields ; Vitrectomy ; Xenon

OBJECTIVETo investigate the asymmetry of fibers in the posterior limb of the internal capsule with diffusion tensor imaging.

METHODSTwenty-nine volunteers (right-handers: 20, left-handers: 9) were enrolled in this study. All the data were obtained using a 1.5 tesla scanner (Signa EXCITE II. GE Medical Systems). The parameters including apparent diffusion coefficient (ADC), fractional anisotropy (FA) and eigenvalue lambda1, lambda2, lambda3 were acquired from the posterior limb of the internal capsule in both hemisphere of brain, and paired t-test was used for statistical differences between the hemisphere.

RESULTSNo differences of ADC and lambda1 were found among the right-handers, but FA in the internal capsule of left hemisphere was larger than that in the right (0.72+/-0.03 compared with 0.70 +/-0.04, P=0.001), and lambda2, lambda3 in the left was lower than that in the right [(4.39+/-0.32 compared with 4.50+/-0.33)x10(-3) mm(2)/s, P=0.016 and (2.19 +/-0.34 compared with 2.29 +/-0.40)x10(-3) mm(2)/s, P=0.024, respectively]. In contrast to the results among the right-handers, all parameters in the left-handers showed no statistical differences.

CONCLUSIONThe fibers in the posterior limb of the internal capsule of left hemisphere might be well sheathed with myelin among right-handers.

Adult ; Diffusion Magnetic Resonance Imaging ; methods ; Female ; Humans ; Internal Capsule ; physiology ; Male ; Nerve Fibers, Myelinated ; physiology

OBJECTIVES: This study evaluated the effects of intraradicular moisture on the pushout bond strength of a fibre post luted with several self-adhesive resin cements. MATERIALS AND METHODS: Endodontically treated root canals were treated with one of three luting cements: (1) RelyX U100, (2) Clearfil SA, and (3) G-Cem. Roots were then divided into four subgroups according to the moisture condition tested: (I) dry: excess water removed with paper points followed by dehydration with 95% ethanol, (II) normal moisture: canals blot-dried with paper points until appearing dry, (III) moist: canals dried by low vacuum using a Luer adapter, and (IV) wet: canals remained totally flooded. Two 1-mm-thick slices were obtained from each root sample and bond strength was measured using a push-out test setup. The data were analysed using a two-way analysis of variance and the Bonferroni post hoc test with p = 0.05. RESULTS: Statistical analysis demonstrated that moisture levels had a significant effect on the bond strength of luting cements (p < 0.05), with the exception of G-Cem. RelyX U100 displayed the highest bond strength under moist conditions (III). Clearfil SA had the highest bond strength under normal moisture conditions (II). Statistical ranking of bond strength values was as follows: RelyX U100 > Clearfil SA > G-Cem. CONCLUSIONS: The degree of residual moisture significantly affected the adhesion of luting cements to radicular dentine.
Dehydration ; Dental Pulp Cavity ; Dentin* ; Ethanol ; Nerve Fibers, Myelinated* ; Resin Cements* ; Vacuum ; Water