No abstract available.
Ultrasonography*

No abstract available.
Decompression Sickness* ; Decompression*

No abstract available.
Breast Neoplasms* ; Breast* ; Lymphedema* ; Upper Extremity*

No abstract available.
Decompression Sickness* ; Decompression* ; Spinal Cord Injuries* ; Spinal Cord*

No abstract available.
Finite Element Analysis* ; Prostheses and Implants* ; Tooth*

No abstract available.

In the rat brain, partial ischemia causes a delayed neuronal degeneration that occurs hours to days after reoxygenation. It is generally thought that the ischemic damage is initiated by neurotoxicity mediated through glutamate receptors, particulaly NMDA subtypes. Calcium entry through the NMDA receptor is responsible for the synaptic plasiticity and neuronal pathology. Degradation of MAP-2 and NF200, a major components of neuronal cytoskeleton, by Ca2+-dependent protease after NMDA receptor activation has been postulated in delayed neuronal damage. Calcium-activated protease calpain, excessive degradation of MAP-2, together with the calpain-sensitive microtubule and neurofilaments, would be expected to disrupt intracellular transport- and membrane-related functions that is vital to neurons. Changed of NR subunit 2A, 2B, MAP2 and NF200 in rat hippncampal postsynaptic density[PSD] after partial ischemic injury were investigated though immunoblot analyses. To understand the effect of Ca2+, influx through NMDA receptors on neuronal damage which is manifested by cytoskeletal disruption, morphological change was examined through immunohistochemistry and routine staining method. We found that immunoreactivity to NR2B receptor subuit in the hippocampal formation PSD was upregulated while MAP2 and NF200 was down-regulted at 18 hours after initial partial ischemic insult. On the other hand, morphological changes of neuronal cell in partial ischemic conditions were manifested as eosinophilic inclusion bodies in the cytoplasm which is progression of neuronal damage after 6 days. Calcium influx through NR1/NR2B receptor channel may activate intracellular proteases which would degrade cytoskeleton. Proteolysis of cytoskeleton leads to its reorganization and eventually damages normal function of cell membrane which cause neuronal cell death.
Animals ; Brain ; Calcium ; Calpain ; Cell Death ; Cell Membrane ; Cytoplasm ; Cytoskeleton ; Eosinophils ; Hand ; Hippocampus* ; Immunohistochemistry ; Inclusion Bodies ; Ischemia ; Microtubules ; N-Methylaspartate ; Neurons ; Pathology ; Peptide Hydrolases ; Proteolysis* ; Rats* ; Receptors, Glutamate ; Receptors, N-Methyl-D-Aspartate

Transient cerebral ischemia was induced by bilateral common carotid artery ligation with reperfusion to understand its effect on the expression of NMDA receptor subunits 2A (NR2A), 2B (NR2B), and NF200 The changes of the expressions of NR2A, NR2B, and NF200 in cerebral postsynaptic density (PSD) were evaluated through immunoblot analyses. The expressions of NR2A and NF200 were markedly decreased until 18 hours after reperfusion, while that of NR2B was increased. The immunohistochemistry with NFIGO antibody showed that NF200 protein, which is a marker for neuronal damage, was also significantly decreased at this time point indicating neuronal damages, and the morphological damages of neuronal cells were evident by hyperchromatic condensation of nucleus, irregular cell membrane, displacement of nucleus, and chromatolysis of Nissl substances in toluidine blue stain. However, from 18 hours to 3 day after reperfusion, immunoblot analyses showed that NF200 was increased significantly, while the expression of NR2A were recovered to the control level and that of NR2B was returned to somewhat higher level than control. The NR1/NR2B-type receptor is known to have a longer offset decay time than NR1/NR2A-type ones, and to be more potent in Ca2 influxing. Therefore, our results suggest that, until 18 hours, neurons are damaged by overinflux of Ca2 through NR1/NR2B receptors which helps to degrade NF200 by Ca2 sensitive professes resulting in damages to intracellular transport. The fact that the expression of NF200 was increased even though the NR2A and NR2B are control level during 18 hours to 3 days after damage suggests that NMDA receptor subunits expressed at this time may not form functional receptors. The worsening of some neuronal damages after 3 days may indicate that an abnormal reorganization of elevated NF200 between 18 hours to 3 days further disturb intracellular transport and functions of cell membrane which cause cell death.
Animals ; Carotid Artery, Common ; Cell Death ; Cell Membrane ; Cerebral Cortex* ; Immunohistochemistry ; Ischemic Attack, Transient* ; Ligation ; N-Methylaspartate* ; Neurons ; Post-Synaptic Density ; Rats* ; Reperfusion ; Tolonium Chloride

In the rat brain, global hypoxia cause a delayed neuronal degeneration that occurs hours to days after reoxygenation. It is generally thought that the ischemic damage is initiated by neurotoxicity mediated through glutamate receptors, particulary NMDA subtypes. Calcium entry through the NMDA receptor is responsible for the synaptic plasiticity and neuronal pathology. Degradation of MAP-2 and NF200, a major components of neuronal cytoskeleton, by Ca2+-dependent protease after NMDA receptor activation has been postulated in delayed neuronal damage. Changes of NR subunit 2B, MAP2 and NF200 in rat brain postsynaptic density[PSD] after hypoxic injury were investigated through immunoblot analyses. To understand the effect of Ca2+ influx through NMDA receptors on neuronal damage which is manifested by cytoskeletal disruption, morphological change was examined through immunohistochemistry and H & E staining. We found that immunoreactivity to NR2B antibody in the cerebral cortex PSD was up-regulated while MAP2 and NF200 was down-regulated at 30 hours after initial hypoxic insult. At this time, morphological changes of neuronal cells in hypoxic conditions were manifested as down-regulation of MAP2 and NF200 immunoreactivities, hyperchromatic condensation of cytoplasm and nucleus, homogenizing cell change, expansion of perineuronal space and dispersion of chromatin. From 3 days, NR2B, MAP2, NF200 were up-regulated simultaneously. On the other hand, morphological alterations in hypoxic neurons were progress further. Our present results suggests that Calcium influx through NR1/NR2B receptor channel is effective whithin 30 hours but ineffective from 30 hours. Delayed neuronal cell death triggered by Ca2+ influx through NR1/NR2B receptor channel within 30 hours, which may activate intracellular profeases. Proteolysis of cytoskeleton by activated protease leads to its abnormal reorganization and eventually damages normal function of cell membrane which causes neuronal cell death.
Animals ; Anoxia ; Brain ; Calcium ; Cell Death ; Cell Membrane ; Cerebral Cortex* ; Chromatin ; Cytoplasm ; Cytoskeleton* ; Down-Regulation ; Hand ; Immunohistochemistry ; N-Methylaspartate* ; Neurons ; Pathology ; Proteolysis ; Rats* ; Receptors, Glutamate ; Receptors, N-Methyl-D-Aspartate ; Up-Regulation*

No abstract available.
Blister ; Humans ; Necrosis ; Rhabdomyolysis