Laboratory MCAO Test-Bed for Developing Wavefront Sensing Concepts.

PubMed

Goncharov, A V; Dainty, J C; Esposito, S; Puglisi, A

2005-07-11

An experimental optical bench test-bed for developing new wavefront sensing concepts for Multi-Conjugate Adaptive Optics (MCAO) systems is described. The main objective is to resolve imaging problems associated with wavefront sensing of the atmospheric turbulence for future MCAO systems on Extremely Large Telescopes (ELTs). The test-bed incorporates five reference sources, two deformable mirrors (DMs) and atmospheric phase screens to simulate a scaled version of a 10-m adaptive telescope operating at the K band. A recently proposed compact tomographic wavefront sensor is employed for star-oriented DMs control in the MCAO system. The MCAO test-bed is used to verify the feasibility of the wavefront sensing concept utilizing a field lenslet array for multi-pupil imaging on a single detector. First experimental results of MCAO correction with the proposed tomographic wavefront sensor are presented and compared to the theoretical prediction based on the characteristics of the phase screens, actuator density of the DMs and the guide star configuration.

Pretreatment of 6-shogaol attenuates oxidative stress and inflammation in middle cerebral artery occlusion-induced mice.

PubMed

Na, Ji-Young; Song, Kibbeum; Lee, Ju-Woon; Kim, Sokho; Kwon, Jungkee

2016-10-05

6-Shogaol can be extracted from ginger and has been shown to exert anti-inflammatory and antioxidant activities, which are potentially relevant to the treatment of central nervous system disorders. Oxidative stress and inflammation are closely associated with ischemic injury and can eventually result in neuronal death. The aim of this study was to evaluate if 6-shogaol exerts neuroprotective activity. To this end, we determined its effects on oxidative stress and inflammation in a mouse model of middle cerebral artery occlusion (MCAO)-induced brain damage. In this model, MCAO was induced in C57BL/6 mice (30-35g, 9 weeks) for 1h, followed by 24h reperfusion. Mice were treated orally with 6-shogaol (0.1ml, 5 or 20mg/kg) once daily for 7 consecutive days prior to MCAO. We found that 6-shogaol significantly reduced neurological deficit scores and the mean infarct area. Moreover, 6-shogaol improved the behavioral deficits in the MCAO group. In addition, 6-shogaol pretreatment dampened MCAO-mediated production of reactive oxygen species and inflammatory cytokines. Mechanistic studies revealed that 6-shogaol inhibits the cysteinyl leukotriene 1 receptor (CysLT1R) and mitogen-activated protein kinase (MAPK) signaling proteins, thus providing a potential pharmacological mechanism for our observations. These results suggest that 6-shogaol can ameliorate the outcomes of MCAO and could thus be used as a potential preventive of stroke. Copyright © 2016 Elsevier B.V. All rights reserved.

6-Mercaptopurine exerts an immunomodulatory and neuroprotective effect on permanent focal cerebral occlusion in rats.

PubMed

Chang, Chih-Zen; Kwan, Aij-Lie; Howng, Shen-Long

2010-08-01

A bursting cascade of inflammation imposes progressive neurological deterioration after experimental stroke has been demonstrated. In our study, 6-mercaptopurine (6-mp) has been successful in alleviating cerebral infarct in a rodent permanent middle cerebral artery occlusion (pMCAO) model. The present study was aimed to examine the effect of 6-mp on cytokine levels in experimental stroke. The rodent pMCAO model was employed. A dose of 2 mg/kg 6-mp or vehicle (0.1 mol/L PBS) was administered intraperitoneally 30 min after the induction of pMCAO. Neurological score, serum, and cerebrospinal fluid (CSF) cytokines such as IL-1beta, IL-6, and TNF-alpha and infarct volume were determined 48 h after pMCAO. Cerebral infarction volume was significantly decreased in animals treated with 6-mp (74.3%, p < 0.01), and the ratio of tissue edema was also decreased in 6-mp-treated groups (71%). Animals receiving 6-mp thus showed a significant decrease in IL-1 and TNF-alpha (18/43% and 48/64% in CSF/serum, respectively) when compared with the pMCAO groups (p < 0.01). This study demonstrates that 6-mp interposes the production of IL-1 and TNF-alpha in CSF and serum, attenuates ischemic brain injury, and thus alleviates neurological deficits in the pMCAO animals. These findings also offer first evidence that 6-mp may attenuate TNF-alpha-related neuron apoptosis and also support the notion that 6-mp and other anti-inflammatory agents could potentially have therapeutic uses in cases of cerebral infarct.

Assessment of Blood-Brain Barrier Permeability by Dynamic Contrast-Enhanced MRI in Transient Middle Cerebral Artery Occlusion Model after Localized Brain Cooling in Rats.

PubMed

Kim, Eun Soo; Lee, Seung-Koo; Kwon, Mi Jung; Lee, Phil Hye; Ju, Young-Su; Yoon, Dae Young; Kim, Hye Jeong; Lee, Kwan Seop

2016-01-01

The purpose of this study was to evaluate the effects of localized brain cooling on blood-brain barrier (BBB) permeability following transient middle cerebral artery occlusion (tMCAO) in rats, by using dynamic contrast-enhanced (DCE)-MRI. Thirty rats were divided into 3 groups of 10 rats each: control group, localized cold-saline (20℃) infusion group, and localized warm-saline (37℃) infusion group. The left middle cerebral artery (MCA) was occluded for 1 hour in anesthetized rats, followed by 3 hours of reperfusion. In the localized saline infusion group, 6 mL of cold or warm saline was infused through the hollow filament for 10 minutes after MCA occlusion. DCE-MRI investigations were performed after 3 hours and 24 hours of reperfusion. Pharmacokinetic parameters of the extended Tofts-Kety model were calculated for each DCE-MRI. In addition, rotarod testing was performed before tMCAO, and on days 1-9 after tMCAO. Myeloperoxidase (MPO) immunohisto-chemistry was performed to identify infiltrating neutrophils associated with the inflammatory response in the rat brain. Permeability parameters showed no statistical significance between cold and warm saline infusion groups after 3-hour reperfusion 0.09 ± 0.01 min(-1) vs. 0.07 ± 0.02 min(-1), p = 0.661 for K(trans); 0.30 ± 0.05 min(-1) vs. 0.37 ± 0.11 min(-1), p = 0.394 for kep, respectively. Behavioral testing revealed no significant difference among the three groups. However, the percentage of MPO-positive cells in the cold-saline group was significantly lower than those in the control and warm-saline groups (p < 0.05). Localized brain cooling (20℃) does not confer a benefit to inhibit the increase in BBB permeability that follows transient cerebral ischemia and reperfusion in an animal model, as compared with localized warm-saline (37℃) infusion group.

Identification of Proteins Differentially Expressed by Quercetin Treatment in a Middle Cerebral Artery Occlusion Model: A Proteomics Approach.

PubMed

Shah, Fawad-Ali; Park, Dong-Ju; Koh, Phil-Ok

2018-06-20

Cerebral ischemia is a major cause of death and neurological disability. It also leads to severe brain tissue damage by excessive generation of oxidative stress. Quercetin is a bioflavonoid substance that acts an antioxidant agent and exerts a neuroprotective effect against cerebral ischemia. The aim of this study was to detect specific proteins that are differentially expressed in response to quercetin treatment in focal cerebral ischemia. Adult male rats were intraperitoneally injected with vehicle or quercetin (10 mg/kg) 30 min prior to right middle cerebral artery occlusion (MCAO). Brain tissues were collected 24 h after MCAO surgery and right cerebral cortices proteins were identified by two-dimensional gel electrophoresis and mass spectrometry. MCAO leads to neurological behavior disorders, infarction, and histopathological change. However, quercetin treatment alleviated MCAO-induced neuronal deficits and damages. We identified specific proteins differentially expressed between vehicle- and quercetin-treated animals. Among these detected proteins, isocitrate dehydrogenase [NAD + ], adenosylhomocysteinase, pyruvate kinase, and ubiquitin carboxy terminal hydrolase L1 were decreased in vehicle-treated animals, while quercetin administration alleviated the MCAO-induced decreases in these proteins. However, 60 kDa heat shock protein and collapsin response mediator protein 2 were increased in the vehicle-treated animals, and quercetin treatment attenuated increases in these proteins. The expression changes in these proteins were confirmed by Western blot and reverse transcription-PCR analyses. These proteins are associated with cellular differentiation, metabolism, and oxidative stress related proteins. These results suggest that quercetin reduces ischemic injury by modulating the expression of various proteins in focal cerebral ischemia.

Ferulic acid regulates the AKT/GSK-3β/CRMP-2 signaling pathway in a middle cerebral artery occlusion animal model

PubMed Central

Gim, Sang-A; Sung, Jin-Hee; Shah, Fawad-Ali; Kim, Myeong-Ok

2013-01-01

Ferulic acid, a component of the plants Angelica sinensis (Oliv.) Diels and Ligusticum chuanxiong Hort, exerts a neuroprotective effect by regulating various signaling pathways. This study showed that ferulic acid treatment prevents the injury-induced increase of collapsin response mediator protein 2 (CRMP-2) in focal cerebral ischemia. Glycogen synthase kinase-3β (GSK-3β) regulates CRMP-2 function through phosphorylation of CRMP-2. Moreover, the pro-apoptotic activity of GSK-3β is inactivated by phosphorylation by Akt. This study investigated whether ferulic acid modulates the expression of CRMP-2 and its upstream targets, Akt and GSK-3β, in focal cerebral ischemia. Male rats were treated immediately with ferulic acid (100 mg/kg, i.v.) or vehicle after middle cerebral artery occlusion (MCAO), and then cerebral cortices were collected 24 hr after MCAO. MCAO resulted in decreased levels of phospho-Akt and phospho-GSK-3β, while ferulic acid treatment prevented the decrease in the levels of these proteins. Moreover, phospho-CRMP-2 and CRMP-2 levels increased during MCAO, whereas ferulic acid attenuated these injury-induced increases. These results demonstrate that ferulic acid regulates the Akt/GSK-3β/CRMP-2 signaling pathway in focal cerebral ischemic injury, thereby protecting against brain injury. PMID:23825478

-(S)-Alpha-phenyl-2-pyridine-ethanamine Dihydrochloride-, a low affinity uncompetitive N-methyl-D-aspartic acid antagonist, is effective in rodent models of global and focal ischemia.

PubMed

Cregan, E F; Peeling, J; Corbett, D; Buchan, A M; Saunders, J; Auer, R N; Gao, M; Mccarthy, D J; Eisman, M S; Campbell, T M; Murray, R J; Stagnitto, M L; Palmer, G C

1997-12-01

[(S)-Alpha-phenyl-2-pyridine-ethanamine dihydrochloride] (ARL 15896AR) is a low affinity uncompetitive N-methyl-D-aspartic acid receptor antagonist that was tested in animal models of anoxia and ischemia. Pretreatment of rodents with ARL 15896AR extended survival time during exposure to hypoxia. With the rat four-vessel occlusion model of global ischemia (20 min), oral dosing commencing at reflow, resulted in significant protection of the CA1 hippocampal neurons. ARL 15896AR was, however, ineffective in the rat two-vessel occlusion model and in the gerbil models of forebrain ischemia, the latter due to an inability to attain suitable plasma levels. In the spontaneously hypertensive rat model of middle cerebral artery occlusion (MCAO) (2 hr plus 22 hr reflow), acute dosing with ARL 15896AR (i.p.) beginning from 30 min before or up to 1 hr post-MCAO significantly reduced cortical infarct volume. The ability of ARL 15896AR to influence infarct size, as well as functional correlates was examined in SHR after 90 min of MCAO. T2 weighted magnetic resonance images taken at 2 and 6 days post-MCAO revealed significantly smaller lesion sizes in the group receiving injections with ARL 15896AR beginning 30 min after occlusion. Spontaneously hypertensive rats were subsequently tested (30-42 days post-MCAO) and found to be deficient in skilled use of the forepaws (staircase test). The contralateral forepaw was most severely impaired, however, ARL 15896AR treatment prevented motor impairment in only the ipsilateral forepaw. Histopathological examination of cortical infarct size was unremarkable between treated and control rats. The findings indicate that ARL 15896AR exhibits neuroprotection in global and focal models of ischemia

Uric acid promotes oxidative stress and enhances vascular endothelial cell apoptosis in rats with middle cerebral artery occlusion.

PubMed

Song, Chengfu; Zhao, Xiangdong

2018-05-15

In patients with cerebral infarction (CI), elevated serum uric acid (UA) level may exacerbate the occurrence and development of carotid atherosclerosis (AS). Our study intended to explore the underlying mechanism. We enrolled 86 patients with CI, and divided them into four groups: Non-AS, AS-mild, AS-moderate, and AS-severe groups; the levels of UA and oxidative stress-related factors in serum were detected. The middle cerebral artery occlusion (MCAO) model was used to stimulate CI in rats, and different doses of UA were administrated. The levels of oxidative stress-related factors in serum were detected. Hematoxylin & eosin (H&E) staining was used to observe the morphological alterations, and the apoptotic cell death detection kit was used to detect apoptotic cells. Increased UA concentration and enhanced oxidative stress were found in AS patients. H&E staining results showed that UA treatment exacerbated morphological damage in rats with MCAO, promoted oxidative stress, and enhanced vascular endothelial cell apoptosis in rats with MCAO. © 2017 The Author(s).

Assessment of Blood-Brain Barrier Permeability by Dynamic Contrast-Enhanced MRI in Transient Middle Cerebral Artery Occlusion Model after Localized Brain Cooling in Rats

PubMed Central

Kim, Eun Soo; Kwon, Mi Jung; Lee, Phil Hye; Ju, Young-Su; Yoon, Dae Young; Kim, Hye Jeong; Lee, Kwan Seop

2016-01-01

Objective The purpose of this study was to evaluate the effects of localized brain cooling on blood-brain barrier (BBB) permeability following transient middle cerebral artery occlusion (tMCAO) in rats, by using dynamic contrast-enhanced (DCE)-MRI. Materials and Methods Thirty rats were divided into 3 groups of 10 rats each: control group, localized cold-saline (20℃) infusion group, and localized warm-saline (37℃) infusion group. The left middle cerebral artery (MCA) was occluded for 1 hour in anesthetized rats, followed by 3 hours of reperfusion. In the localized saline infusion group, 6 mL of cold or warm saline was infused through the hollow filament for 10 minutes after MCA occlusion. DCE-MRI investigations were performed after 3 hours and 24 hours of reperfusion. Pharmacokinetic parameters of the extended Tofts-Kety model were calculated for each DCE-MRI. In addition, rotarod testing was performed before tMCAO, and on days 1-9 after tMCAO. Myeloperoxidase (MPO) immunohisto-chemistry was performed to identify infiltrating neutrophils associated with the inflammatory response in the rat brain. Results Permeability parameters showed no statistical significance between cold and warm saline infusion groups after 3-hour reperfusion 0.09 ± 0.01 min-1 vs. 0.07 ± 0.02 min-1, p = 0.661 for Ktrans; 0.30 ± 0.05 min-1 vs. 0.37 ± 0.11 min-1, p = 0.394 for kep, respectively. Behavioral testing revealed no significant difference among the three groups. However, the percentage of MPO-positive cells in the cold-saline group was significantly lower than those in the control and warm-saline groups (p < 0.05). Conclusion Localized brain cooling (20℃) does not confer a benefit to inhibit the increase in BBB permeability that follows transient cerebral ischemia and reperfusion in an animal model, as compared with localized warm-saline (37℃) infusion group. PMID:27587960

Effect of oral administration of Pheretima aspergillum (earthworm) in rats with cerebral infarction induced by middle-cerebral artery occlusion.

PubMed

Liu, Chung-Hsiang; Lin, Yi-Wen; Tang, Nou-Ying; Liu, Hsu-Jan; Huang, Chih-Yang; Hsieh, Ching-Liang

2012-01-01

We investigated the curative effect of Pheretima aspergillum (earthworm, PA) on rats with middle cerebral artery occlusion (MCAo). The MCAo-induced cerebral infarction was established and its underlying mechanisms by counting the infarction areas and evaluating the rats' neurological status. Immunostaining was used to test the expression of NeuN, and glial fibrillary acidic (GFAP), S100B, and brain-derived neurotrophic factor (BDNF) proteins. Our results showed that oral administration of PA for two weeks to rats with MCAo successfully reduced cerebral infarction areas in the cortex and striatum, and also reduced scores of neurological deficit. The PA-treated MCAo rats showed greatly decreased neuronal death, glial proliferation, and S100B proteins in the penumbra area of the cortex and in the ischemic core area of the cortex, but BDNF did not changed. These results demonstrated novel and detailed cellular mechanisms underlying the neuroprotective effects of PA in MCAo rats.

Identification of proteins regulated by ferulic acid in a middle cerebral artery occlusion animal model-a proteomics approach.

PubMed

Sung, Jin-Hee; Cho, Eun-Hae; Cho, Jae-Hyeon; Won, Chung-Kil; Kim, Myeong-Ok; Koh, Phil-Ok

2012-11-01

Ferulic acid plays a neuroprotective role in cerebral ischemia. The aim of this study was to identify the proteins that are differentially expressed following ferulic acid treatment during ischemic brain injury using a proteomics technique. Middle cerebral artery occlusion (MCAO) was performed to induce a focal cerebral ischemic injury in adult male rats, and ferulic acid (100 mg/kg) or vehicle was administered immediately after MCAO. Brain tissues were collected 24 hr after MCAO. The proteins in the cerebral cortex were separated using two-dimensional gel electrophoresis and were identified by mass spectrometry. We detected differentially expressed proteins between vehicle- and ferulic acid-treated animals. Adenosylhomocysteinase, isocitrate dehydrogenase [NAD(+)], mitogen-activated protein kinase kinase 1 and glyceraldehyde-3-phosphate dehydrogenase were decreased in the vehicle-treated group, and ferulic acid prevented the injury-induced decreases in these proteins. However, pyridoxal phosphate phosphatase and heat shock protein 60 were increased in the vehicle-treated group, while ferulic acid prevented the injury-induced increase in these proteins. It is accepted that these enzymes are involved in cellular metabolism and differentiation. Thus, these findings suggest evidence that ferulic acid plays a neuroprotective role against focal cerebral ischemia through the up- and down-modulation of specific enzymes.

TIA model is attainable in Wistar rats by intraluminal occlusion of the MCA for 10min or shorter.

PubMed

Durukan Tolvanen, A; Tatlisumak, E; Pedrono, E; Abo-Ramadan, U; Tatlisumak, T

2017-05-15

Transient ischemic attack (TIA) has received only little attention in the experimental research field. Recently, we introduced a TIA model for mice, and here we set similar principles for simulating this human condition in Wistar rats. In the model: 1) transient nature of the event is ensured, and 2) 24h after the event animals are free from any sensorimotor deficit and from any detectable lesion by magnetic resonance imaging (MRI). Animals experienced varying durations of ischemia (5, 10, 12.5, 15, 25, and 30min, n=6-8pergroup) by intraluminal middle cerebral artery occlusion (MCAO). Ischemia severity and reperfusion rates were controlled by cerebral blood flow measurements. Sensorimotor neurological evaluations and MRI at 24h differentiated between TIA and ischemic stroke. Hematoxylin and eosin staining and apoptotic cell counts revealed pathological correlates of the event. We found that already 12.5min of ischemia was long enough to induce ischemic stroke in Wistar rats. Ten min or shorter durations induced neither gross neurological deficits nor infarcts visible on MRI, but histologically caused selective neuronal necrosis. A separate group of animals with 10min of ischemia followed up to 1week after reperfusion remained free of infarction and any MRI signal change. Thus, 10min or shorter focal cerebral ischemia induced by intraluminal MCAO in Wistar rats provides a clinically relevant TIA the rat. This model is useful for studying molecular correlates of TIA. Copyright © 2017 Elsevier B.V. All rights reserved.

Epigallocatechin-3-Gallate Reduces Neuronal Apoptosis in Rats after Middle Cerebral Artery Occlusion Injury via PI3K/AKT/eNOS Signaling Pathway

PubMed Central

Zhonghang, Xu; Tongtong, Liu; Wanshu, Guo

2018-01-01

Background/Aims Epigallocatechin-3-gallate (EGCG) has neuroprotective effects and the ability to resist amyloidosis. This study observed the protective effect of EGCG against neuronal injury in rat models of middle cerebral artery occlusion (MCAO) and investigated the mechanism of action of PI3K/AKT/eNOS signaling pathway. Methods Rat models of permanent MCAO were established using the suture method. Rat behavior was measured using neurological deficit score. Pathology and apoptosis were measured using HE staining and TUNEL. Oxidative stress and brain injury markers were examined using ELISA. Apoptosis-related proteins and PI3K/AKT/eNOS signaling pathway were determined using western blot assay and immunohistochemistry. Results EGCG decreased neurological function score, protected nerve cells, inhibited neuronal apoptosis, and inhibited oxidative stress injury and brain injury markers level after MCAO. EGCG reduced the apoptotic rate of neurons, increased the expression of Bcl-2, and decreased the expression of Caspase-3 and Bax. After LY294002 suppressed the PI3K pathway, the protective effect of EGCG decreased after administration of PI3K inhibitors. Conclusion EGCG has a protective effect on rat brain injury induced by MCAO, possibly by modulating the PI3K/AKT/eNOS signaling pathway. PMID:29770336

Bepridil decreases Aβ and calcium levels in the thalamus after middle cerebral artery occlusion in rats

PubMed Central

Sarajärvi, Timo; Lipsanen, Anu; Mäkinen, Petra; Peräniemi, Sirpa; Soininen, Hilkka; Haapasalo, Annakaisa; Jolkkonen, Jukka; Hiltunen, Mikko

2012-01-01

Alzheimer's disease (AD) and cerebral ischaemia share similar features in terms of altered amyloid precursor protein (APP) processing and β-amyloid (Aβ) accumulation. We have previously shown that Aβ and calcium deposition, and β-secretase activity, are robustly increased in the ipsilateral thalamus after transient middle cerebral artery occlusion (MCAO) in rats. Here, we investigated whether the non-selective calcium channel blocker bepridil, which also inhibits β-secretase cleavage of APP, affects thalamic accumulation of Aβ and calcium and in turn influences functional recovery in rats subjected to MCAO. A 27-day bepridil treatment (50 mg/kg, p.o.) initiated 2 days after MCAO significantly decreased the levels of soluble Aβ40, Aβ42 and calcium in the ipsilateral thalamus, as compared with vehicle-treated MCAO rats. Expression of seladin-1/DHCR24 protein, which is a potential protective factor against neuronal damage, was decreased at both mRNA and protein levels in the ipsilateral thalamus of MCAO rats. Conversely, bepridil treatment restored seladin-1/DHCR24 expression in the ipsilateral thalamus. Bepridil treatment did not significantly affect heme oxygenase-1- or NAD(P)H quinone oxidoreductase-1-mediated oxidative stress or inflammatory responses in the ipsilateral thalamus of MCAO rats. Finally, bepridil treatment mitigated MCAO-induced alterations in APP processing in the ipsilateral thalamus and improved contralateral forelimb use in MCAO rats. These findings suggest that bepridil is a plausible therapeutic candidate in AD or stroke owing to its multifunctional role in key cellular events that are relevant for the pathogenesis of these diseases. PMID:22805236

Progesterone treatment shows greater protection in brain vs. retina in a rat model of middle cerebral artery occlusion: Progesterone receptor levels may play an important role

PubMed Central

Allen, Rachael S.; Sayeed, Iqbal; Oumarbaeva, Yuliya; Morrison, Katherine C.; Choi, Paul H.; Pardue, Machelle T.; Stein, Donald G.

2018-01-01

Background/Objective To determine whether inflammation increases in retina as it does in brain following middle cerebral artery occlusion (MCAO), and whether the neurosteroid progesterone, shown to have protective effects in both retina and brain after MCAO, reduces inflammation in retina as well as brain. Methods MCAO rats treated systemically with progesterone or vehicle were compared with shams. Protein levels of cytosolic NF-κB, nuclear NF-κB, phosphorylated NF-κB, IL-6, TNF-α, CD11b, progesterone receptor A and B, and pregnane × receptor were assessed in retinas and brains at 24 and 48 h using western blots. Results Following MCAO, significant increases were observed in the following inflammatory markers: pNF-κB and CD11b at 24 h in both brain and retina, nuclear NF-κB at 24 h in brain and 48 h in retina, and TNF-α at 24 h in brain. Progesterone treatment in MCAO animals significantly attenuated levels of the following markers in brain: pNF-κB, nuclear NF-κB, IL-6, TNF-α, and CD11b, with significantly increased levels of cytosolic NF-κB. Retinas from progesterone-treated animals showed significantly reduced levels of nuclear NF-κB and IL-6 and increased levels of cytosolic NF-κB, with a trend for reduction in other markers. Post-MCAO, progesterone receptors A and B were upregulated in brain and downregulated in retina. Conclusion Inflammatory markers increased in both brain and retina after MCAO, with greater increases observed in brain. Progesterone treatment reduced inflammation, with more dramatic reductions observed in brain than retina. This differential effect may be due to differences in the response of progesterone receptors in brain and retina after injury. PMID:27802245

Calibration of the MCAO Canopus Bench

NASA Astrophysics Data System (ADS)

Garcia-Rissmann, Aurea; Rigaut, François; Bec, Matthieu; Boccas, Maxime; Galvez, Ramon; Gausachs, Gaston; Gratadour, Damien; Neichel, Benoit

The final phase of implementation of all optical components, as well as their integration and tests on the Canopus MCAO bench is currently underway. We present here a detailed description of the LGS and NGS WFS calibration sequences implemented through MYST (MCAO Yorick Smart Tool), a yorick+python+glade software package developed in-house which allows multiple users to control and monitor the bench remotely over the network using EPICS commands. A fine tuning of the optical setup and a better understanding of the flexure/temperature dependencies is being carried out and will allow us to build the many look-up tables to be eventually used by the system (e.g. telescope primary and secondary mirrors). Preliminary work on non-common path aberrations to account for the static aberrations in the central 60 arcsec science field of view (FoV) has been done iteratively using a science focal plane wavefront sensor and has shown good results both in individual directions as well as simultaneously over the entire FoV, the latter using the tomographic approach (presented in another paper in this conference).

Progesterone treatment shows greater protection in brain vs. retina in a rat model of middle cerebral artery occlusion: Progesterone receptor levels may play an important role.

PubMed

Allen, Rachael S; Sayeed, Iqbal; Oumarbaeva, Yuliya; Morrison, Katherine C; Choi, Paul H; Pardue, Machelle T; Stein, Donald G

2016-11-22

To determine whether inflammation increases in retina as it does in brain following middle cerebral artery occlusion (MCAO), and whether the neurosteroid progesterone, shown to have protective effects in both retina and brain after MCAO, reduces inflammation in retina as well as brain. MCAO rats treated systemically with progesterone or vehicle were compared with shams. Protein levels of cytosolic NF-κB, nuclear NF-κB, phosphorylated NF-κB, IL-6, TNF-α, CD11b, progesterone receptor A and B, and pregnane X receptor were assessed in retinas and brains at 24 and 48 h using western blots. Following MCAO, significant increases were observed in the following inflammatory markers: pNF-κB and CD11b at 24 h in both brain and retina, nuclear NF-κB at 24 h in brain and 48 h in retina, and TNF-α at 24 h in brain.Progesterone treatment in MCAO animals significantly attenuated levels of the following markers in brain: pNF-κB, nuclear NF-κB, IL-6, TNF-α, and CD11b, with significantly increased levels of cytosolic NF-κB. Retinas from progesterone-treated animals showed significantly reduced levels of nuclear NF-κB and IL-6 and increased levels of cytosolic NF-κB, with a trend for reduction in other markers. Post-MCAO, progesterone receptors A and B were upregulated in brain and downregulated in retina. Inflammatory markers increased in both brain and retina after MCAO, with greater increases observed in brain. Progesterone treatment reduced inflammation, with more dramatic reductions observed in brain than retina. This differential effect may be due to differences in the response of progesterone receptors in brain and retina after injury.

Elevating microRNA-122 in blood improves outcomes after temporary middle cerebral artery occlusion in rats

PubMed Central

Jickling, Glen C; Ander, Bradley P; Hull, Heather; Zhan, Xinhua; Cox, Christopher; Shroff, Natasha; Dykstra-Aiello, Cheryl; Stamova, Boryana; Sharp, Frank R

2015-01-01

Because our recent studies have demonstrated that miR-122 decreased in whole blood of patients and in whole blood of rats following ischemic stroke, we tested whether elevating blood miR-122 would improve stroke outcomes in rats. Young adult rats were subjected to a temporary middle cerebral artery occlusion (MCAO) or sham operation. A polyethylene glycol-liposome-based transfection system was used to administer a miR-122 mimic after MCAO. Neurological deficits, brain infarction, brain vessel integrity, adhesion molecule expression and expression of miR-122 target and indirect-target genes were examined in blood at 24 h after MCAO with or without miR-122 treatment. miR-122 decreased in blood after MCAO, whereas miR-122 mimic elevated miR-122 in blood 24 h after MCAO. Intravenous but not intracerebroventricular injection of miR-122 mimic decreased neurological deficits and brain infarction, attenuated ICAM-1 expression, and maintained vessel integrity after MCAO. The miR-122 mimic also down-regulated direct target genes (e.g. Vcam1, Nos2, Pla2g2a) and indirect target genes (e.g. Alox5, Itga2b, Timp3, Il1b, Il2, Mmp8) in blood after MCAO which are predicted to affect cell adhesion, diapedesis, leukocyte extravasation, eicosanoid and atherosclerosis signaling. The data show that elevating miR-122 improves stroke outcomes and we postulate this occurs via downregulating miR-122 target genes in blood leukocytes. PMID:26661204

The Kringle-2 domain of tissue plasminogen activator significantly reduces mortality and brain infarction in middle cerebral artery occlusion rats.

PubMed

Zhang, Haitao; Bi, Feng; Xiao, Chunlan; Liu, Jianxia; Wang, Zhixia; Liu, Jian-Ning; Zhang, Jing

2010-08-01

Tissue plasminogen activator (TPA) showed brain-protective activity within the first 15 min after cerebral ischemia in rats. To understand its molecular mechanism, TPA derivates were intracerebroventricularly administered at 15 min before, and 15, 90, 120 min after middle cerebral artery occlusion (MCAO) in rats. The reduction in mortality and cerebral infarction at 24 h was seen only with TPA administered at 15 min after MCAO. The down-regulation of endogenous TPA by the intracerebroventricular injection of TPA was found to be responsible for the protective effect on the integrity of blood-brain barrier after MCAO, as well as for the reduction in mortality and cerebral infarction. Moreover, for the first time we have found that the Kringle-2 domain is essential for the brain-protective activity of TPA.

Long-lasting neuroprotection and neurological improvement in stroke models with new, potent and brain permeable inhibitors of poly(ADP-ribose) polymerase

PubMed Central

Moroni, F; Cozzi, A; Chiarugi, A; Formentini, L; Camaioni, E; Pellegrini-Giampietro, DE; Chen, Y; Liang, S; Zaleska, MM; Gonzales, C; Wood, A; Pellicciari, R

2012-01-01

BACKGROUND AND PURPOSES Thienyl-isoquinolone (TIQ-A) is a relatively potent PARP inhibitor able to reduce post-ischaemic neuronal death in vitro. Here we have studied, in different stroke models in vivo, the neuroprotective properties of DAMTIQ and HYDAMTIQ, two TIQ-A derivatives able to reach the brain and to inhibit PARP-1 and PARP-2. EXPERIMENTAL APPROACH Studies were carried out in (i) transient (2 h) middle cerebral artery occlusion (tMCAO), (ii) permanent MCAO (pMCAO) and (iii) electrocoagulation of the distal portion of MCA in conjunction with transient (90 min) bilateral carotid occlusion (focal cortical ischaemia). KEY RESULTS In male rats with tMCAO, HYDAMTIQ (0.1–10 mg·kg−1) injected i.p. three times, starting 4 h after MCAO, reduced infarct volumes by up to 70%, reduced the loss of body weight by up to 60% and attenuated the neurological impairment by up to 40%. In age-matched female rats, HYDAMTIQ also reduced brain damage. Protection, however, was less pronounced than in the male rats. In animals with pMCAO, HYDAMTIQ administered 30 min after MCAO reduced infarct volumes by approximately 40%. In animals with focal cortical ischaemia, HYDAMTIQ treatment decreased post-ischaemic accumulation of PAR (the product of PARP activity) and the presence of OX42-positive inflammatory cells in the ischaemic cortex. It also reduced sensorimotor deficits for up to 90 days after MCAO. CONCLUSION AND IMPLICATIONS Our results show that HYDAMTIQ is a potent PARP inhibitor that conferred robust neuroprotection and long-lasting improvement of post-stroke neurological deficits. PMID:21913897

Electro-acupuncture up-regulates astrocytic MCT1 expression to improve neurological deficit in middle cerebral artery occlusion rats.

PubMed

Lu, Yan; Zhao, Haijun; Wang, Yuan; Han, Bingbing; Wang, Tong; Zhao, Hong; Cui, Kemi; Wang, Shijun

2015-08-01

Cerebral ischemia is one of the common diseases treated by electro-acupuncture (EA). Although the clinical efficacy has been widely affirmed, the mechanisms of action leading to the health benefits are not understood. In this study, the role of EA in modulating the lactate energy metabolism and lactate transportation was explored on the middle cerebral artery occlusion (MCAO) ischemic rat model. Repeated EA treatments once daily for 7 days were applied to the MCAO rats and neurological function evaluation was performed. Brain tissues were harvested for lactate concentration examination, immunohistochemical staining, Western blot and qRT-PCR analyses for the expressions of lactate transporter (monocarboxylate transporter 1, MCT1) and glial fibrillary acidic protein (GFAP). The animal behavioral tests showed that the 7-day EA treatments significantly promoted the recovery of neurological deficits in the MCAO rats, which correlated with the enhanced lactate energy metabolism in the ischemic brain. In the cortical ischemic area of the MCAO rats, EA treatments led to the activation of astrocytes, and induced a further increase of lactate transporter (monocarboxylate transporter 1, MCT1) expression in astrocytes at both protein and mRNA levels. Our results suggest that the EA treatments activated lactate metabolism in the resident astrocytes around the ischemic area and up-regulated the expression of MCT1 in these astrocytes which facilitated the transfer of intracellular lactate to extracellular domain to be utilized by injured neurons to improve the neurological deficit. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of treadmill exercise on 5-HT, 5-HT1A receptor and brain derived neurophic factor in rats after permanent middle cerebral artery occlusion.

PubMed

Lan, Xiaofang; Zhang, Meng; Yang, Wan; Zheng, Zongju; Wu, Yuan; Zeng, Qian; Liu, Shudong; Liu, Ke; Li, Guangqin

2014-05-01

It has been well documented that exercise promotes neurological rehabilitation in patients with cerebral ischemia. However, the exact mechanisms have not been fully elucidated. This study aimed to discuss the effect of treadmill exercise on expression levels of 5-HT, 5-HT1A receptor (5-HT1AR) and brain derived neurophic factor (BDNF) in rat brains after permanent middle cerebral artery occlusion (pMCAO). A total of 55 rats were randomly divided into 3 groups: pMCAO group, pMCAO and treadmill exercise (pMCAO + Ex) group, and sham-operated group. Rats in pMCAO + Ex group underwent treadmill exercise for 16 days. Neurological function was evaluated by modified Neurological Severity Scores (mNSS). High-performance liquid chromatography-electrochemical detection system was used to determine the content of 5-HT in cortex tissues. The protein levels of 5-HT1AR, BDNF and synaptophysin were measured by Western blot. The mNSS in pMCAO + Ex group was lower than that in pMCAO group on day 19 post-MCAO (p < 0.001). The content of 5-HT dropped to 3.81 ± 1.86 ng/ml in pMCAO group (43.84 ± 2.05 ng/ml in sham-operated group), but increased in pMCAO + Ex group (10.06 ± 1.80 ng/ml). The protein expressions levels of synaptophysin, 5-HT1AR and BDNF were downregulated after cerebral ischemia (p < 0.05), and upregulated after treadmill exercise (p < 0.05). These results indicate that treadmill exercise improves neurologic function, enhances neuronal plasticity and upregulates the levels of 5-HT, 5-HT1AR and BDNF in rats with pMCAO.

Electroacupuncture: a new approach to open the blood-brain barrier in rats recovering from middle cerebral artery occlusion.

PubMed

Zhang, Jiangsong; Lin, Xianming; Zhou, Hui; Chen, Yuanyuan; Xiao, Shuangkai; Jiao, Junyue; Zhao, Yibin; Di, Zhong

2018-06-14

To examine for an opening effect on the blood-brain barrier (BBB) in intact rats and rats with experimental ischaemia-reperfusion (I/R) during the recovery period after various electroacupuncture (EA) treatments with different time courses, and to determine whether there is a time-dependent effect. An additional objective was to determine whether this method could induce the penetration of nerve growth factor (NGF) through the BBB. A middle cerebral artery occlusion (MCAO) model was first established. We chose different stimulation time courses and observed the effects of EA treatment (100 Hz frequency; 2 mA intensity) at GV20 and GV26 on the BBB in rats recovering from MCAO 3 weeks after modelling. The rats were injected with 2% Evans blue (EB) saline. The brain water content was measured using a wet/dry weighing method. The degree of penetration of EB was detected using spectrophotometry and laser confocal microscopy. The rats were then injected with NGF, and the concentration of NGF in the brain tissues was measured using ELISA. The increase in the BBB permeability was most notable following the 8 min EA stimulation (P<0.05), which may be advantageous for the targeted delivery of drugs (such as NGF) into the brain. Additionally, this effect did not appear to cause brain oedema (P>0.05) in healthy or MCAO rats. EA treatment for a certain stimulation time at GV20 and GV26 in MCAO rats can increase BBB permeability. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Progesterone Treatment in Two Rat Models of Ocular Ischemia

PubMed Central

Allen, Rachael S.; Olsen, Timothy W.; Sayeed, Iqbal; Cale, Heather A.; Morrison, Katherine C.; Oumarbaeva, Yuliya; Lucaciu, Irina; Boatright, Jeffrey H.; Pardue, Machelle T.; Stein, Donald G.

2015-01-01

Purpose. To determine whether the neurosteroid progesterone, shown to have protective effects in animal models of traumatic brain injury, stroke, and spinal cord injury, is also protective in ocular ischemia animal models. Methods. Progesterone treatment was tested in two ocular ischemia models in rats: a rodent anterior ischemic optic neuropathy (rAION) model, which induces permanent monocular optic nerve stroke, and the middle cerebral artery occlusion (MCAO) model, which causes transient ischemia in both the retina and brain due to an intraluminal filament that blocks the ophthalmic and middle cerebral arteries. Visual function and retinal histology were assessed to determine whether progesterone attenuated retinal injury in these models. Additionally, behavioral testing and 2% 2,3,5-triphenyltetrazolium chloride (TTC) staining in brains were used to compare progesterone's neuroprotective effects in both retina and brain using the MCAO model. Results. Progesterone treatment showed no effect on visual evoked potential (VEP) reduction and retinal ganglion cell loss in the permanent rAION model. In the transient MCAO model, progesterone treatment reduced (1) electroretinogram (ERG) deficits, (2) MCAO-induced upregulation of glutamine synthetase (GS) and glial fibrillary acidic protein (GFAP), and (3) retinal ganglion cell loss. As expected, progesterone treatment also had significant protective effects in behavioral tests and a reduction in infarct size in the brain. Conclusions. Progesterone treatment showed protective effects in the retina following MCAO but not rAION injury, which may result from mechanistic differences with injury type and the therapeutic action of progesterone. PMID:26024074

Non-invasive detection of matrix-metalloproteinase activity in a mouse model of cerebral ischemia using multispectral optoacoustic tomography

NASA Astrophysics Data System (ADS)

Ni, Ruiqing; Vaas, Markus; Ren, Wuwei; Klohs, Jan

2018-02-01

Matrix metalloproteinases (MMPs) play important roles in the pathophysiology of cerebral ischemia. Here we visualized in vivo MMP activity in the transient middle cerebral artery occlusion (tMCAO) mouse model using multispectral optoacoustic imaging (MSOT) with a MMP-activatable probe. MSOT data was co-registered with structural magnetic resonance imaging (MRI) obtained at 7 T for localization of signal distribution. We demonstrated upregulated MMP signal within the focal ischemic lesion in the tMCAO mouse model using MSOT/MRI multimodal imaging. This convenient non-invasive method will allow repetitive measurement following the time course of MMP-lesion development in ischemic stroke animal model.

The Antiepileptic Drug Levetiracetam Suppresses Non-Convulsive Seizure Activity and Reduces Ischemic Brain Damage in Rats Subjected to Permanent Middle Cerebral Artery Occlusion

PubMed Central

Cuomo, Ornella; Rispoli, Vincenzo; Leo, Antonio; Politi, Giovanni Bosco; Vinciguerra, Antonio; di Renzo, Gianfranco; Cataldi, Mauro

2013-01-01

The antiepileptic drug Levetiracetam (Lev) has neuroprotective properties in experimental stroke, cerebral hemorrhage and neurotrauma. In these conditions, non-convulsive seizures (NCSs) propagate from the core of the focal lesion into perilesional tissue, enlarging the damaged area and promoting epileptogenesis. Here, we explore whether Lev neuroprotective effect is accompanied by changes in NCS generation or propagation. In particular, we performed continuous EEG recordings before and after the permanent occlusion of the middle cerebral artery (pMCAO) in rats that received Lev (100 mg/kg) or its vehicle immediately before surgery. Both in Lev-treated and in control rats, EEG activity was suppressed after pMCAO. In control but not in Lev-treated rats, EEG activity reappeared approximately 30-45 min after pMCAO. It initially consisted in single spikes and, then, evolved into spike-and-wave and polyspike-and-wave discharges. In Lev-treated rats, only rare spike events were observed and the EEG power was significantly smaller than in controls. Approximately 24 hours after pMCAO, EEG activity increased in Lev-treated rats because of the appearance of polyspike events whose power was, however, significantly smaller than in controls. In rats sacrificed 24 hours after pMCAO, the ischemic lesion was approximately 50% smaller in Lev-treated than in control rats. A similar neuroprotection was observed in rats sacrificed 72 hours after pMCAO. In conclusion, in rats subjected to pMCAO, a single Lev injection suppresses NCS occurrence for at least 24 hours. This electrophysiological effect could explain the long lasting reduction of ischemic brain damage caused by this drug. PMID:24236205

Role of the NMDA receptor and iron on free radical production and brain damage following transient middle cerebral artery occlusion.

PubMed

Im, Doo Soon; Jeon, Jeong Wook; Lee, Jin Soo; Won, Seok Joon; Cho, Sung Ig; Lee, Yong Beom; Gwag, Byoung Joo

2012-05-21

Excess activation of ionotropic glutamate receptors and iron is believed to contribute to free radical production and neuronal death following hypoxic ischemia. We examined the possibility that both NMDA receptor activation and iron overload determine spatial and temporal patterns of free radical production after transient middle cerebral artery occlusion (tMCAO) in male Sprague-Dawley rats. Mitochondrial free radical (MFR) levels were maximally increased in neurons in the core at 1 h and 24 h after tMCAO. Early MFR production was blocked by administration of MK-801, an NMDA receptor antagonist, but not deferoxamine, an iron chelator. Neither MK-801 nor deferoxamine attenuated late MFR production in the core. Increased MFRs were observed in penumbral neurons within 6 h and gradually increased over 24 h after tMCAO. Slowly-evolving MFRs in the core and penumbra were accompanied by iron overload. Deferoxamine blocked iron overload but reduced MFR production only in the penumbra. Combined MK-801/deferoxamine reduced late MFR production in both core and penumbra in an additive manner. Combination therapy significantly ameliorated infarction compared with monotherapy. These findings suggest that the NMDA receptor activation and iron overload mediate late MFR production and infarction after tMCAO. Copyright © 2012 Elsevier B.V. All rights reserved.

A novel animal model of dysphagia following stroke.

PubMed

Sugiyama, Naoto; Nishiyama, Eiji; Nishikawa, Yukitoshi; Sasamura, Takashi; Nakade, Shinji; Okawa, Katsumasa; Nagasawa, Tadashi; Yuki, Akane

2014-02-01

Patients who have an ischemic stroke are at high risk of swallowing disorders. Aspiration due to swallowing disorders, specifically delayed trigger of the pharyngeal stage of swallowing, predisposes such patients to pneumonia. In the present study, we evaluated swallowing reflex in a rat model of transient middle cerebral artery occlusion (tMCAO), which is one of the most common experimental animal models of cerebral ischemia, in order to develop a novel animal model of dysphagia following ischemic stroke. A swallowing reflex was elicited by a 10-s infusion of distilled water (DW) to the pharyngolaryngeal region in the tMCAO rat model. Swallowing reflex was estimated using the electromyographic activity of the mylohyoid muscle from 1 to 3 weeks after surgery. Two weeks after tMCAO, the number of swallows significantly decreased and the onset latency of the first swallow was prolonged compared with that of the sham group. The number of swallows in rats significantly increased by infusions of 10 mM citric acid and 0.6 μM capsaicin to the pharyngolaryngeal region compared with the number from infusion of DW. It has been reported that sensory stimulation of the pharyngolaryngeal region with citric acid, capsaicin, and L-menthol ameliorates hypofunction of pharyngeal-stage swallowing in dysphagia patients. Therefore, the tMCAO rat model may show some of the symptoms of pharyngeal-stage swallowing disorders, similar to those in patients with ischemic stroke. This rat tMCAO model has the potential to become a novel animal model of dysphagia following stroke that is useful for development of therapeutic methods and drugs.

Depletion of CD11c+ Cells Does Not Influence Outcomes in Mice Subjected to Transient Middle Cerebral Artery Occlusion.

PubMed

Kraft, Peter; Scholtyschik, Karolina; Schuhmann, Michael K; Kleinschnitz, Christoph

2017-01-01

While it has been shown that different T-cell subsets have a detrimental role in the acute phase of ischemic stroke, data on the impact of dendritic cells (DC) are missing. Classic DC can be characterized by the cluster of differentiation (CD)11c surface antigen. In this study, we depleted CD11c+ cells by using a CD11c-diphtheria toxin (DTX) receptor mouse strain that allows selective depletion of CD11c+ cells by DTX injection. For stroke induction, we used the model of transient middle cerebral artery occlusion (tMCAO) and analyzed stroke volume and functional outcome on days 1 and 3 as well as expression of prototypical pro- and anti-inflammatory cytokines on day 1 after tMCAO. Three different protocols for CD11c+ cell depletion, tMCAO duration, and readout time point were applied. Injection of DTX (5 or 100 ng/g) reliably depleted CD11c+ cells without influencing the fractions of other immune cell subsets. CD11c+ cell depletion had no impact on stroke volume, but mice with a longer DTX pretreatment performed worse than those with vehicle treatment. CD11c+ cell depletion led to a decrease in cortical interleukin (IL)-1β and IL-6 messenger ribonucleic acid levels. We show, for the first time, that CD11c+ cell depletion does not influence stroke volume in a mouse model of focal cerebral ischemia. Nevertheless, given the unspecificity of the CD11c surface antigen for DC, mouse models that allow a more selective depletion of DC are needed to investigate the role of DC in stroke pathophysiology. © 2017 S. Karger AG, Basel.

Infarct Volume Prediction by Early Magnetic Resonance Imaging in a Murine Stroke Model Depends on Ischemia Duration and Time of Imaging.

PubMed

Leithner, Christoph; Füchtemeier, Martina; Jorks, Devi; Mueller, Susanne; Dirnagl, Ulrich; Royl, Georg

2015-11-01

Despite standardization of experimental stroke models, final infarct sizes after middle cerebral artery occlusion (MCAO) vary considerably. This introduces uncertainties in the evaluation of drug effects on stroke. Magnetic resonance imaging may detect variability of surgically induced ischemia before treatment and thus improve treatment effect evaluation. MCAO of 45 and 90 minutes induced brain infarcts in 83 mice. During, and 3 and 6 hours after MCAO, we performed multiparametric magnetic resonance imaging. We evaluated time courses of cerebral blood flow, apparent diffusion coefficient (ADC), T1, T2, accuracy of infarct prediction strategies, and impact on statistical evaluation of experimental stroke studies. ADC decreased during MCAO but recovered completely on reperfusion after 45 and partially after 90-minute MCAO, followed by a secondary decline. ADC lesion volumes during MCAO or at 6 hours after MCAO largely determined final infarct volumes for 90 but not for 45 minutes MCAO. The majority of chance findings of final infarct volume differences in random group allocations of animals were associated with significant differences in early ADC lesion volumes for 90, but not for 45-minute MCAO. The prediction accuracy of early magnetic resonance imaging for infarct volumes depends on timing of magnetic resonance imaging and MCAO duration. Variability of the posterior communicating artery in C57Bl6 mice contributes to differences in prediction accuracy between short and long MCAO. Early ADC imaging may be used to reduce errors in the interpretation of post MCAO treatment effects on stroke volumes. © 2015 American Heart Association, Inc.

Parecoxib is neuroprotective in spontaneously hypertensive rats after transient middle cerebral artery occlusion: a divided treatment response?

PubMed

Kelsen, Jesper; Kjaer, Katrine; Chen, Gang; Pedersen, Michael; Røhl, Lisbeth; Frøkiaer, Jørgen; Nielsen, Søren; Nyengaard, Jens R; Rønn, Lars Christian B

2006-12-06

Anti-inflammatory treatment affects ischemic damage and neurogenesis in rodent models of cerebral ischemia. We investigated the potential benefit of COX-2 inhibition with parecoxib in spontaneously hypertensive rats (SHRs) subjected to transient middle cerebral artery occlusion (tMCAo). Sixty-four male SHRs were randomized to 90 min of intraluminal tMCAo or sham surgery. Parecoxib (10 mg/kg) or isotonic saline was administered intraperitoneally (IP) during the procedure, and twice daily thereafter. Nineteen animals were euthanized after 24 hours, and each hemisphere was examined for mRNA expression of pro-inflammatory cytokines and COX enzymes by quantitative RT-PCR. Twenty-three tMCAo animals were studied with diffusion and T2 weighted MRI within the first 24 hours, and ten of the SHRs underwent follow-up MRI six days later. Thirty-three SHRs were given 5-bromo-2'-deoxy-uridine (BrdU) twice daily on Day 4 to 7 after tMCAo. Animals were euthanized on Day 8 and the brains were studied with free-floating immunohistochemistry for activated microglia (ED-1), hippocampal granule cell BrdU incorporation, and neuronal nuclei (NeuN). Infarct volume estimation was done using the 2D nucleator and Cavalieri principle on NeuN-stained coronal brain sections. The total number of BrdU+ cells in the dentate gyrus (DG) of the hippocampus was estimated using the optical fractionator. We found a significant reduction in infarct volume in parecoxib treated animals one week after tMCAo (p < 0.03). Cortical ADC values in the parecoxib group were markedly less increased on Day 8 (p < 0.01). Interestingly, the parecoxib treated rats were segregated into two subgroups, suggesting a responder vs. non-responder phenomenon. We found indications of mRNA up-regulation of IL-1beta, IL-6, TNF-alpha and COX-2, whereas COX-1 remained unaffected. Hippocampal granule cell BrdU incorporation was not affected by parecoxib treatment. Presence of ED-1+ activated microglia in the hippocampus was related

Progression of Diabetic Capillary Occlusion: A Model

PubMed Central

Gens, John Scott; Glazier, James A.; Burns, Stephen A.; Gast, Thomas J.

2016-01-01

An explanatory computational model is developed of the contiguous areas of retinal capillary loss which play a large role in diabetic maculapathy and diabetic retinal neovascularization. Strictly random leukocyte mediated capillary occlusion cannot explain the occurrence of large contiguous areas of retinal ischemia. Therefore occlusion of an individual capillary must increase the probability of occlusion of surrounding capillaries. A retinal perifoveal vascular sector as well as a peripheral retinal capillary network and a deleted hexagonal capillary network are modelled using Compucell3D. The perifoveal modelling produces a pattern of spreading capillary loss with associated macular edema. In the peripheral network, spreading ischemia results from the progressive loss of the ladder capillaries which connect peripheral arterioles and venules. System blood flow was elevated in the macular model before a later reduction in flow in cases with progression of capillary occlusions. Simulations differing only in initial vascular network structures but with identical dynamics for oxygen, growth factors and vascular occlusions, replicate key clinical observations of ischemia and macular edema in the posterior pole and ischemia in the retinal periphery. The simulation results also seem consistent with quantitative data on macular blood flow and qualitative data on venous oxygenation. One computational model applied to distinct capillary networks in different retinal regions yielded results comparable to clinical observations in those regions. PMID:27300722

Calibrations for a MCAO Imaging System

NASA Astrophysics Data System (ADS)

Hibon, Pascale; B. Neichel; V. Garrel; R. Carrasco

2017-09-01

"GeMS, the Gemini Multi conjugate adaptive optics System installed at the Gemini South telescope (Cerro Pachon, Chile) started to deliver science since the beginning of 2013. GeMS is using the Multi Conjugate AdaptiveOptics (MCAO) technique allowing to dramatically increase the corrected field of view (FOV) compared to classical Single Conjugated Adaptive Optics (SCAO) systems. It is the first sodium-based multi-Laser Guide Star (LGS) adaptive optics system. It has been designed to feed two science instruments: GSAOI, a 4k×4k NIR imager covering 85"×85" with 0.02" pixel scale, and Flamingos-2, a NIR multi-object spectrograph. We present here an overview of the calibrations necessary for reducing and analysing the science datasets obtained with GeMS+GSAOI."

Licorice Pretreatment Protects Against Brain Damage Induced by Middle Cerebral Artery Occlusion in Mice.

PubMed

Lim, Chiyeon; Lim, Sehyun; Lee, Byoungho; Kim, Buyeo; Cho, Suin

2018-05-01

Licorice is extracted from the roots of plants in the Glycyrrhiza genus, especially Glycyrrhiza uralensis in China and Korea. It has several pharmacological activities, including neuro-protective, anti-fungal, and anti-cariogenic effects. Ischemia/reperfusion-induced brain injury is a leading cause of adult disability and death; thus, the identification of anti-apoptotic, neuro-protective therapeutic agents is viewed as an attractive drug development strategy. Infarct volumes and the expression of several apoptosis-related proteins, including Bcl-xL, Bcl-2, caspase-8, and caspase-9, were evaluated by western blotting in the brains of mice subjected to middle cerebral artery occlusion (MCAO). Three consecutive days of oral pretreatment with the methanol extract of licorice (GRex) significantly reduced infarct volumes 24 h after MCAO. In addition, GRex effectively inhibited the activation of caspase-9 by upregulating protein expression of Bcl-xL and Bcl-2. The neuro-protective effect of licorice was due to its regulation of apoptosis-related proteins. These data suggest that licorice could be a potential candidate for the treatment of ischemia-induced brain damage.

Effects of the methylene chloride fraction from modified Boyang-Hwan-o-Tang, a polyherbal medicine on transient middle cerebral artery occlusion-induced ischemia in rats.

PubMed

Oh, Tae Woo; Jung, Hyo Won; Shin, Gil Jo; Park, Yong-Ki

2014-01-28

To study the neuroprotective effect of the methylene chloride fraction from modified Boyang-Hwan-o-Tang (mBHT-MC), especially against neuronal apoptosis. mBHT-MC (10, 25 or 50 mg/kg) was orally administered once per day for 7 days in transient middle cerebral artery occlusion (MCAO)-induced ischemic rats. Infarction volumes was measured by 2,3,5-triphenyltetrazolium chloride (TTC) staining, neurological deficit score and the expression of apoptotic proteins such as Bcl-2, Bax and caspase-3 by Western blot in MCAO-induced ischemic brain. Neuronal apoptosis in ischemic phenumbra was also investigated by staining with hematoxylin and eosin, Nissl and Hoechst 33342. mBHT-MC administration in MCAO rats significantly decreased infarction volume and neurological deficit scores. mBHT-MC significantly enhanced Bcl-2 expression, and inhibited Bax and caspase-3 expression in ischemic brain. In addition, mBHT-MC significantly decreased the number of apoptotic neuronal cells in ischemic brains. mBHT-MC administration inhibits neuronal death induced by cerebral ischemia in rats, suggesting that mBHT-MC has a neuroprotective property in brain ischemia.

Protective effects of alkaloid extract from Leonurus heterophyllus on cerebral ischemia reperfusion injury by middle cerebral ischemic injury (MCAO) in rats.

PubMed

Liang, Hao; Liu, Ping; Wang, Yunshan; Song, Shuliang; Ji, Aiguo

2011-07-15

The neuronal damage following cerebral ischemia is a serious risk to stroke patients. The aim of this study was to investigate the neuroprotective effects of alkaloid extract from Leonurus heterophyllus (LHAE) on cerebral ischemic injury. After 24 h of reperfusion following ischemia for 2 h induced by middle cerebral artery occlusion (MCAO), some rats were intraperitoneally administered different doses of LHAE (3.6, 7.2, 14.4 mg/kg, respectively). Neurological examination was measured in all animals. Infarct volume, myeloperoxidase (MPO) activity, levels of nitrate/nitrite metabolite (NO) and apoptosis ratio of nerve fiber in brain were determined. The results showed that LHAE at 7.2 mg/kg or 14.4 mg/kg exerted significantly decreasing neurological deficit scores and reducing the infarct volume on rats with focal cerebral ischemic injury (p<0.05). At those dose, the MPO content were significantly decreased in ischemic brain as compared with model group (p<0.05). LHAE at 14.4 mg/kg significantly decreased the NO level compared with the model group (p<0.05). In addition, LHAE significantly decreased the apoptosis ratio of nerve fiber compared with the model group (p<0.05). This study suggests that LHAE may be used for treatment of ischemic stroke as a neuroprotective agent. Further studies are warranted to assess the efficacy and safety of LHAE in patients. Copyright © 2011 Elsevier GmbH. All rights reserved.

Human Neural Stem Cell Extracellular Vesicles Improve Recovery in a Porcine Model of Ischemic Stroke

PubMed Central

Webb, Robin L.; Kaiser, Erin E.; Jurgielewicz, Brian J.; Spellicy, Samantha; Scoville, Shelley L.; Thompson, Tyler A.; Swetenburg, Raymond L.; Hess, David C.; West, Franklin D.

2018-01-01

Background and Purpose— Recent work from our group suggests that human neural stem cell–derived extracellular vesicle (NSC EV) treatment improves both tissue and sensorimotor function in a preclinical thromboembolic mouse model of stroke. In this study, NSC EVs were evaluated in a pig ischemic stroke model, where clinically relevant end points were used to assess recovery in a more translational large animal model. Methods— Ischemic stroke was induced by permanent middle cerebral artery occlusion (MCAO), and either NSC EV or PBS treatment was administered intravenously at 2, 14, and 24 hours post-MCAO. NSC EV effects on tissue level recovery were evaluated via magnetic resonance imaging at 1 and 84 days post-MCAO. Effects on functional recovery were also assessed through longitudinal behavior and gait analysis testing. Results— NSC EV treatment was neuroprotective and led to significant improvements at the tissue and functional levels in stroked pigs. NSC EV treatment eliminated intracranial hemorrhage in ischemic lesions in NSC EV pigs (0 of 7) versus control pigs (7 of 8). NSC EV–treated pigs exhibited a significant decrease in cerebral lesion volume and decreased brain swelling relative to control pigs 1-day post-MCAO. NSC EVs significantly reduced edema in treated pigs relative to control pigs, as assessed by improved diffusivity through apparent diffusion coefficient maps. NSC EVs preserved white matter integrity with increased corpus callosum fractional anisotropy values 84 days post-MCAO. Behavior and mobility improvements paralleled structural changes as NSC EV–treated pigs exhibited improved outcomes, including increased exploratory behavior and faster restoration of spatiotemporal gait parameters. Conclusions— This study demonstrated for the first time that in a large animal model novel NSC EVs significantly improved neural tissue preservation and functional levels post-MCAO, suggesting NSC EVs may be a paradigm changing stroke therapeutic

The Gemini-South MCAO operational model: insights on a new era of telescope operation

NASA Astrophysics Data System (ADS)

Trancho, Gelys; Bec, Matthieu; Artigau, Etienne; d'Orgeville, Celine; Gratadour, Damien; Rigaut, Francois J.; Walls, Brian

2008-07-01

The Gemini Observatory is implementing a Multi-Conjugate Adaptive Optics (MCAO) system as a facility instrument for the Gemini South telescope (GeMS). The system will include 5 Laser Guide Stars, 3 Natural Guide Stars, and 3 deformable mirrors, optically conjugated at different altitudes, to achieve near-uniform atmospheric compensation over a one arc minute square field of view. This setup implies some level of operational complexity. In this paper we describe how GeMS will be integrated into the flow of Gemini operations, from the observing procedures necessary to execute the programs in the queue (telescope control software, observing tools, sequence executor) to the safety implementation needed such as spotters/ASCAM, space command and laser traffic control software.

Curcumin by down-regulating NF-kB and elevating Nrf2, reduces brain edema and neurological dysfunction after cerebral I/R.

PubMed

Li, Wei; Suwanwela, Nijasri C; Patumraj, Suthiluk

2016-07-01

Oxidation, inflammation, and apoptosis are three critical factors for the pathogenic mechanism of cerebral ischemia/reperfusion (I/R) injury. Curcumin exhibits substantial biological properties via anti-oxidation, anti-inflammation and anti-apoptotic effects; however, the molecular mechanism underlying the effects of curcumin against cerebral I/R injury remains unclear. To investigate the effects of curcumin on cerebral I/R injury associated with water content, infarction volume, and the expression of nuclear factor-kappa-B (NF-κB) and nuclear factor-erythroid-related factor-2 (Nrf2). Middle cerebral artery occlusion (MCAO, 1-hour occlusion and 24-hour reperfusion) was performed in male Wistar rats (n=64) as a cerebral I/R injury model. In the MCAO+CUR group, the rats were administered curcumin (300mg/kg BW, i.p.) at 30min after occlusion. The same surgical procedures were performed in SHAM rats without MCAO occlusion. At 24h post-operation, the parameters, including neurological deficit scores, blood brain barrier (BBB) disruption, water content, and infarction volume, were determined. Brain tissue NF-κB and Nrf2 expression levels were assayed through immunohistochemistry. Compared with the SHAM group, BBB disruption, neurological deficit, and increased brain water content and infarction volume were markedly demonstrated in the MCAO group. NF-κB expression was enhanced in the MCAO group. However, in the MCAO+CUR group, the upregulation of Nrf2, an anti-oxidation related protein, was consistent with a significant decline in the water content, infarction volume, and NF-κB expression. The protective effects of curcumin against cerebral I/R injury reflect anti-oxidation, anti-inflammation and anti-apoptotic activities, resulting in the elevation of Nrf2 and down-regulation of NF-κB. Copyright © 2015 Elsevier Inc. All rights reserved.

The Neuroprotective Effects of Flaxseed Oil Supplementation on Functional Motor Recovery in a Model of Ischemic Brain Stroke: Upregulation of BDNF and GDNF.

PubMed

Bagheri, Abolqasem; Talei, Sahand; Hassanzadeh, Negar; Mokhtari, Tahmineh; Akbari, Mohammad; Malek, Fatemeh; Jameie, Seyed Behnamedin; Sadeghi, Yousef; Hassanzadeh, Gholamreza

2017-12-01

Cerebral ischemic stroke is a common leading cause of disability. Flaxseed is a richest plant-based source of antioxidants. In this study, the effects of flaxseed oil (FSO) pretreatment on functional motor recovery and gene expression and protein content of neurotrophic factors in motor cortex area in rat model of brain ischemia/reperfusion (I/R) were assessed. Transient middle cerebral artery occlusion (tMCAo) in rats was used as model brain I/R. Rats (6 in each group) were randomly divided into four groups of Control (Co+normal saline [NS]), Sham (Sh+NS), tMCAo+NS and tMCAo+FSO. After three weeks of pretreatment with vehicle or FSO (0.2 ml~800 mg/kg body weight), the rats were operated in sham and ischemic groups. Ischemia was induced for 1 h and then reperfused. After 24 h of reperfusion, neurological examination was performed, and animals were sacrificed, and their brains were used for molecular and histopathological studies. FSO significantly improved the functional motor recovery compared with tMCAo+NS group (P<0.05). A significant reduction in brain-derived neurotrophic factor (BDNF) and glial cell-derived neurotrophic factor (GDNF) mRNAs and protein levels were observed in the tMCAo+NS group compared with Co+NS and Sh+NS group (P<0.05). A significant increase of BDNF and GDNF mRNAs and proteins was recorded in the tMCAo+FSO group compared with Co+NS, Sh+NS and tMCAO+NS groups (P<0.05). The results of the current study demonstrated that pretreatment with FSO had neuroprotective effects on motor cortex area following cerebral ischemic stroke by increasing the neurotrophic factors (BDNF, GDNF).

Activation of the PI3K-Akt pathway promotes neuroprotection of the δ-opioid receptor agonist against cerebral ischemia-reperfusion injury in rat models.

PubMed

Lv, Mei-Rong; Li, Bin; Wang, Ming-Guang; Meng, Fan-Guo; Yu, Jian-Jun; Guo, Feng; Li, Ye

2017-09-01

The central objective was to identify the role of the PI3K-Akt activation pathway on the neuroprotection of δ-opioid receptor agonist (DADLE) against cerebral ischemia-reperfusion (I/R) injury in a rat model. Fifty-five male Sprague-Dawley (SD) rats were included to establish a middle cerebral artery occlusion (MCAO) model which were then divided into the sham, MCAO, LY294002 (MCAO+DADLE+LY294002 [inhibitor of PI3K-Akt pathway]), DADLE (MCAO+DADLE) and DMSO (MCAO+DADLE+DMSO [dimethyl sulphoxide]) groups. The cerebral infarction (CI) volume and nerve cell apoptosis was determined using TTC and TUNEL staining. Quantitative real-time polymerase chain reaction (qRT-PCR), western blotting and immunohistochemistry staining were applied for the expressions of Bad, Bax, Bcl-2 and cleaved caspase-3. The MCAO group showed higher CI volume, nerve cell apoptosis and cleaved caspase-3 expressions than the DADLE and DMSO groups, which were also higher in the LY294002 group than the DADLE group. Compared with the MCAO group, the mRNA and protein expressions of PI3K and Bcl-2, and the protein expressions of p-Akt and p-Bad were elevated, while the mRNA and protein expressions of Bax were decreased in the DADLE and DMSO groups. Decreased mRNA and protein expressions of PI3K and Bcl-2, reduced protein expressions of p-Akt and p-Bad and elevated mRNA and protein expressions of Bax exhibited in the LY294002 group than the DADLE group. These results indicate that activation of PI3K-Akt pathway promotes the neuroprotection of DADLE against cerebral I/R injury in a rat model by decreasing nerve cells apoptosis. Copyright © 2017. Published by Elsevier Masson SAS.

Comparison of different 3D wavefront sensing and reconstruction techniques for MCAO

NASA Astrophysics Data System (ADS)

Bello, Dolores; Vérinaud, Christophe; Conan, Jean-Marc; Fusco, Thierry; Carbillet, Marcel; Esposito, Simone

2003-02-01

The vertical distribution of the turbulence limits the field of view of classical adaptive optics due to the anisoplanatism. Multiconjugate adaptive optics (MCAO) uses several deformable mirrors conjugated to different layers in the atmosphere to overcome this effect. In the last few years, many studies and developments have been done regarding the analysis of the turbulence volume, and the choice of the wavefront reconstruction techniques.An extensive study of MCAO modelisation and performance estimation has been done at OAA and ONERA. The developed Monte Carlo codes allow to simulate and investigate many aspects: comparison of turbulence analysis strategies (tomography or layer oriented) and comparison of different reconstruction approaches. For instance in the layer oriented approach, the control for a given deformable mirror can be either deduced from the whole set of wavefront sensor measurements or only using the associated wavefront sensor. Numerical simulations are presented showing the advantages and disadvantages of these different options for several cases depending on the number, geometry and magnitude of the guide stars.

JM-20 Treatment After MCAO Reduced Astrocyte Reactivity and Neuronal Death on Peri-infarct Regions of the Rat Brain.

PubMed

Ramírez-Sánchez, Jeney; Pires, Elisa Nicoloso Simões; Meneghetti, André; Hansel, Gisele; Nuñez-Figueredo, Yanier; Pardo-Andreu, Gilberto L; Ochoa-Rodríguez, Estael; Verdecia-Reyes, Yamila; Delgado-Hernández, René; Salbego, Christianne; Souza, Diogo O

2018-05-03

Stroke is frequently associated with severe neurological decline and mortality, and its incidence is expected to increase due to aging population. The only available pharmacological treatment for cerebral ischemia is thrombolysis, with narrow therapeutic windows. Efforts aimed to identify new therapeutics are crucial. In this study, we look into plausible molecular and cellular targets for JM-20, a new hybrid molecule, against ischemic stroke in vivo. Male Wistar rats were subjected to 90 min middle cerebral artery occlusion (MCAO) following 23 h of reperfusion. Animals treated with 8 mg/kg JM-20 (p.o., 1 h after reperfusion) showed minimal neurological impairment and lower GABA and IL-1β levels in CSF when compared to damaged rats that received vehicle. Immunocontent of pro-survival, phosphorylated Akt protein decreased in the cortex after 24 h as result of the ischemic insult, accompanied by decreased number of NeuN + cells in the peri-infarct cortex, cornu ammonis 1 (CA1) and dentate gyrus (DG) areas. Widespread reactive astrogliosis in both cortex and hippocampus (CA1, CA3, and DG areas) was observed 24 h post-ischemia. JM-20 prevented the activated Akt reduction, neuronal death, and astrocytes reactivity throughout the brain. Overall, the results reinforce the pharmacological potential of JM-20 as neuroprotective agent and provide important evidences about its molecular and cellular targets in this model of cerebral ischemia.

Clinical Decision Support Model to Predict Occlusal Force in Bruxism Patients.

PubMed

Thanathornwong, Bhornsawan; Suebnukarn, Siriwan

2017-10-01

The aim of this study was to develop a decision support model for the prediction of occlusal force from the size and color of articulating paper markings in bruxism patients. We used the information from the datasets of 30 bruxism patients in which digital measurements of the size and color of articulating paper markings (12-µm Hanel; Coltene/Whaledent GmbH, Langenau, Germany) on canine protected hard stabilization splints were measured in pixels (P) and in red (R), green (G), and blue (B) values using Adobe Photoshop software (Adobe Systems, San Jose, CA, USA). The occlusal force (F) was measured using T-Scan III (Tekscan Inc., South Boston, MA, USA). The multiple regression equation was applied to predict F from the P and RGB. Model evaluation was performed using the datasets from 10 new patients. The patient's occlusal force measured by T-Scan III was used as a 'gold standard' to compare with the occlusal force predicted by the multiple regression model. The results demonstrate that the correlation between the occlusal force and the pixels and RGB of the articulating paper markings was positive (F = 1.62×P + 0.07×R -0.08×G + 0.08×B + 4.74; R 2 = 0.34). There was a high degree of agreement between the occlusal force of the patient measured using T-Scan III and the occlusal force predicted by the model (kappa value = 0.82). The results obtained demonstrate that the multiple regression model can predict the occlusal force using the digital values for the size and color of the articulating paper markings in bruxism patients.

Clinical Decision Support Model to Predict Occlusal Force in Bruxism Patients

PubMed Central

Thanathornwong, Bhornsawan

2017-01-01

Objectives The aim of this study was to develop a decision support model for the prediction of occlusal force from the size and color of articulating paper markings in bruxism patients. Methods We used the information from the datasets of 30 bruxism patients in which digital measurements of the size and color of articulating paper markings (12-µm Hanel; Coltene/Whaledent GmbH, Langenau, Germany) on canine protected hard stabilization splints were measured in pixels (P) and in red (R), green (G), and blue (B) values using Adobe Photoshop software (Adobe Systems, San Jose, CA, USA). The occlusal force (F) was measured using T-Scan III (Tekscan Inc., South Boston, MA, USA). The multiple regression equation was applied to predict F from the P and RGB. Model evaluation was performed using the datasets from 10 new patients. The patient's occlusal force measured by T-Scan III was used as a ‘gold standard’ to compare with the occlusal force predicted by the multiple regression model. Results The results demonstrate that the correlation between the occlusal force and the pixels and RGB of the articulating paper markings was positive (F = 1.62×P + 0.07×R –0.08×G + 0.08×B + 4.74; R2 = 0.34). There was a high degree of agreement between the occlusal force of the patient measured using T-Scan III and the occlusal force predicted by the model (kappa value = 0.82). Conclusions The results obtained demonstrate that the multiple regression model can predict the occlusal force using the digital values for the size and color of the articulating paper markings in bruxism patients. PMID:29181234

Identification of ischemic regions in a rat model of stroke.

PubMed

Popp, Anke; Jaenisch, Nadine; Witte, Otto W; Frahm, Christiane

2009-01-01

Investigations following stroke first of all require information about the spatio-temporal dimension of the ischemic core as well as of perilesional and remote affected tissue. Here we systematically evaluated regions differently impaired by focal ischemia. Wistar rats underwent a transient 30 or 120 min suture-occlusion of the middle cerebral artery (MCAO) followed by various reperfusion times (2 h, 1 d, 7 d, 30 d) or a permanent MCAO (1 d survival). Brains were characterized by TTC, thionine, and immunohistochemistry using MAP2, HSP72, and HSP27. TTC staining reliably identifies the infarct core at 1 d of reperfusion after 30 min MCAO and at all investigated times following 120 min and permanent MCAO. Nissl histology denotes the infarct core from 2 h up to 30 d after transient as well as permanent MCAO. Absent and attenuated MAP2 staining clearly identifies the infarct core and perilesional affected regions at all investigated times, respectively. HSP72 denotes perilesional areas in a limited post-ischemic time (1 d). HSP27 detects perilesional and remote impaired tissue from post-ischemic day 1 on. Furthermore a simultaneous expression of HSP72 and HSP27 in perilesional neurons was revealed. TTC and Nissl staining can be applied to designate the infarct core. MAP2, HSP72, and HSP27 are excellent markers not only to identify perilesional and remote areas but also to discriminate affected neuronal and glial populations. Moreover markers vary in their confinement to different reperfusion times. The extent and consistency of infarcts increase with prolonged occlusion of the MCA. Therefore interindividual infarct dimension should be precisely assessed by the combined use of different markers as described in this study.

Identification of Ischemic Regions in a Rat Model of Stroke

PubMed Central

Popp, Anke; Jaenisch, Nadine; Witte, Otto W.; Frahm, Christiane

2009-01-01

Background Investigations following stroke first of all require information about the spatio-temporal dimension of the ischemic core as well as of perilesional and remote affected tissue. Here we systematically evaluated regions differently impaired by focal ischemia. Methodology/Principal Findings Wistar rats underwent a transient 30 or 120 min suture-occlusion of the middle cerebral artery (MCAO) followed by various reperfusion times (2 h, 1 d, 7 d, 30 d) or a permanent MCAO (1 d survival). Brains were characterized by TTC, thionine, and immunohistochemistry using MAP2, HSP72, and HSP27. TTC staining reliably identifies the infarct core at 1 d of reperfusion after 30 min MCAO and at all investigated times following 120 min and permanent MCAO. Nissl histology denotes the infarct core from 2 h up to 30 d after transient as well as permanent MCAO. Absent and attenuated MAP2 staining clearly identifies the infarct core and perilesional affected regions at all investigated times, respectively. HSP72 denotes perilesional areas in a limited post-ischemic time (1 d). HSP27 detects perilesional and remote impaired tissue from post-ischemic day 1 on. Furthermore a simultaneous expression of HSP72 and HSP27 in perilesional neurons was revealed. Conclusions/Significance TTC and Nissl staining can be applied to designate the infarct core. MAP2, HSP72, and HSP27 are excellent markers not only to identify perilesional and remote areas but also to discriminate affected neuronal and glial populations. Moreover markers vary in their confinement to different reperfusion times. The extent and consistency of infarcts increase with prolonged occlusion of the MCA. Therefore interindividual infarct dimension should be precisely assessed by the combined use of different markers as described in this study. PMID:19274095

Neuroprotective effects of Danggui-Jakyak-San on rat stroke model through antioxidant/antiapoptotic pathway.

PubMed

Kim, Sang-Ho; Chung, Dae-Kyoo; Lee, Young Joon; Song, Chang-Hyun; Ku, Sae-Kwang

2016-07-21

Dangui-Jakyak-San (DJ) is a traditional Korean medicinal polyherb, prescribed typically in patients with insufficient blood supply in Eastern Asia. The DJ also has been reported to have neuroprotective effects in vitro and in vivo studies. The therapeutic potential of DJ was examined in stroke rat model, in comparison with donepezil, a reversible acetylcholinesterase inhibitor. Ischemic stroke rat model was induced by surgery of permanent occlusion of middle cerebral artery (pMCAO). The model was orally administered with distilled water (pMCAO control), donepezil at 10mg/kg (Donepezil) and DJ at 200, 100 and 50mg/kg (DJ 200, DJ 100 and DJ 50, respectively). Sham had the same surgery excepting for the pMCAO, and it was administered with distilled water (sham control). After the administration for 28 days, the groups of DJ exhibited dose-dependent reduction in infarct/defect volumes with improvement in sensorimotor and cognitive motor function, comparing to pMCAO control. The DJ treatments seemed to enhance antiapoptotic and antioxidant effects; increases in antiapoptotic expressions (STAT3 and Pim-1) and decreases in lipid peroxidation (MDA) together with increases in contents of endogenous antioxidant (GSH) and activities of antioxidant enzymes (catalase and SOD). The histopathological analyses revealed significant reduction in neuronal apoptosis (caspase-3 and PARP) and neuronal degradation with atrophy and degeneration, in the DJ treatments. Furthermore, the oxidative stresses (nitrotyrosine as an iNOS factor and 4-HNE as a marker of lipid peroxidation) were observed mild. Although the similar neuroprotective effects were observed, the body weight loss was scarcely alleviated in Donepezil comparing to pMCAO control. These suggest that DJ ameliorate the neurological dysfunction of cerebral ischemia through augmentation of antioxidant defense system and up-regulation of STAT3 and Pim-1. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Oxygen therapy reduces secondary hemorrhage after thrombolysis in thromboembolic cerebral ischemia.

PubMed

Sun, Li; Zhou, Wei; Mueller, Christian; Sommer, Clemens; Heiland, Sabine; Bauer, Alexander T; Marti, Hugo H; Veltkamp, Roland

2010-09-01

Hyperbaric oxygen (HBO) and normobaric hyperoxia (NBO) protect the brain parenchyma and the cerebral microcirculation against ischemia. We studied their effect on secondary hemorrhage after thrombolysis in two thromboembolic middle cerebral artery occlusion (MCAO) (tMCAO) models. Beginning 60 minutes after tMCAO with either thrombin-induced thromboemboli (TT) or calcium-induced thromboemboli (CT), spontaneously hypertensive rats (n=96) breathed either air, 100% O(2) (NBO), or 100% O(2) at 3 bar (HBO) for 1 hour. Immediately thereafter, recombinant tissue plasminogen activator (rt-PA, 9 mg/kg) was injected. Although significant reperfusion was observed after thrombolysis in TT-tMCAO, vascular occlusion persisted in CT-tMCAO. In TT-tMCAO, NBO and HBO significantly reduced diffusion-weighted imaging-magnetic resonance imaging (MRI) lesion volume and postischemic blood-brain barrier (BBB) permeability on postcontrast T1-weighted images. NBO and, significantly more potently, HBO reduced macroscopic hemorrhage on T2* MRI and on corresponding postmortem cryosections. Oxygen therapy lowered hemoglobin content and attenuated activation of matrix metalloproteinases in the ischemic hemisphere. In contrast, NBO and HBO failed to reduce infarct size in CT but both decreased BBB damage and microscopic hemorrhagic transformation. Only HBO reduced hemoglobin extravasation in the ischemic hemisphere. In conclusion, NBO and HBO decrease infarct size after thromboembolic ischemia only if recanalization is successful. As NBO and HBO also reduce postthrombolytic intracerebral hemorrhage, combining the two with thrombolysis seems promising.

Multiple FoV MCAO on its way to the sky

NASA Astrophysics Data System (ADS)

Bergomi, Maria; Viotto, Valentina; Farinato, Jacopo; Marafatto, Luca; Radakrishnan, Kalyan; Ragazzoni, Roberto; Dima, Marco; Magrin, Demetrio; Arcidiacono, Carmelo; Diolaiti, Emiliano; Foppiani, Italo; Lombini, Matteo; Schreiber, Laura; Bertram, Thomas; Bizenberger, Peter; Conrad, Al; Herbst, Tom; Kittmann, Frank; Kopon, Derek; Meschke, Daniel; Zhang, Xianyu

2013-12-01

LINC-NIRVANA, an infrared camera working in a Fizeau interferometric layout, takes advantage of the Layer Oriented MCAO MFoV technique to correct a 2 arcmin FoV using only Natural Guide Stars (NGSs), exploiting the central 10 arcsec with a resolving power of a 23 meter telescope. For each arm of the LBT telescope 2 WaveFront Sensors (WFSs) optically conjugated, respectively at ground and high (7 km) layers, are used to search for NGSs. To avoid unnecessary waste of photons the two sensors look at different FoVs. The ground-layer one, essentially limited by practical conditions, searches for up to 12 NGSs in an annular 2-6 arcmin FoV, while the high-layer one, limited by the pupils superposition, looks for up to 8 NGSs in the central 2 arcmin FoV. The concept has left paper's realm to become glass and metal a few years ago. With the completion of the 2 high-layer WFSs by INAF-Bologna and, recently with the successful tests performed on the first ground-layer WFSs by INAF-Padova, further followed by the GWS Pathfinder experiment to test the ground layer correction at LBT, in collaboration with MPIA-Heidelberg, the concept is finally getting closer to its on-sky commissioning, foreseen in the next very few years. In this paper the basic concepts of MFoV MCAO will be revised, the current status of the system described and the near future toward final completion of the instrument depicted. Moreover a possible path for this concept toward an ELT will be traced.

High-density lipoprotein-based therapy reduces the hemorrhagic complications associated with tissue plasminogen activator treatment in experimental stroke.

PubMed

Lapergue, Bertrand; Dang, Bao Quoc; Desilles, Jean-Philippe; Ortiz-Munoz, Guadalupe; Delbosc, Sandrine; Loyau, Stéphane; Louedec, Liliane; Couraud, Pierre-Olivier; Mazighi, Mikael; Michel, Jean-Baptiste; Meilhac, Olivier; Amarenco, Pierre

2013-03-01

We have previously reported that intravenous injection of high-density lipoproteins (HDLs) was neuroprotective in an embolic stroke model. We hypothesized that HDL vasculoprotective actions on the blood-brain barrier (BBB) may decrease hemorrhagic transformation-associated with tissue plasminogen activator (tPA) administration in acute stroke. We used tPA alone or in combination with HDLs in vivo in 2 models of focal middle cerebral artery occlusion (MCAO) (embolic and 4-hour monofilament MCAO) and in vitro in a model of BBB. Sprague-Dawley rats were submitted to MCAO, n=12 per group. The rats were then randomly injected with tPA (10 mg/kg) or saline with or without human plasma purified-HDL (10 mg/kg). The therapeutic effects of HDL and BBB integrity were assessed blindly 24 hours later. The integrity of the BBB was also tested using an in vitro model of human cerebral endothelial cells under oxygen-glucose deprivation. tPA-treated groups had significantly higher mortality and rate of hemorrhagic transformation at 24 hours in both MCAO models. Cotreatment with HDL significantly reduced stroke-induced mortality versus tPA alone (by 42% in filament MCAO, P=0.009; by 73% in embolic MCAO, P=0.05) and tPA-induced intracerebral parenchymal hematoma (by 92% in filament MCAO, by 100% in embolic MCAO; P<0.0001). This was consistent with an improved BBB integrity. In vitro, HDLs decreased oxygen-glucose deprivation-induced BBB permeability (P<0.05) and vascular endothelial cadherin disorganization. HDL injection decreased tPA-induced hemorrhagic transformation in rat models of MCAO. Both in vivo and in vitro results support the vasculoprotective action of HDLs on BBB under ischemic conditions.

Non-invasive near-infrared fluorescence imaging of the neutrophil response in a mouse model of transient cerebral ischaemia.

PubMed

Vaas, Markus; Enzmann, Gaby; Perinat, Therese; Siler, Ulrich; Reichenbach, Janine; Licha, Kai; Kipar, Anja; Rudin, Markus; Engelhardt, Britta; Klohs, Jan

2017-08-01

Near-infrared fluorescence (NIRF) imaging enables non-invasive monitoring of molecular and cellular processes in live animals. Here we demonstrate the suitability of NIRF imaging to investigate the neutrophil response in the brain after transient middle cerebral artery occlusion (tMCAO). We established procedures for ex vivo fluorescent labelling of neutrophils without affecting their activation status. Adoptive transfer of labelled neutrophils in C57BL/6 mice before surgery resulted in higher fluorescence intensities over the ischaemic hemisphere in tMCAO mice with NIRF imaging when compared with controls, corroborated by ex vivo detection of labelled neutrophils using fluorescence microscopy. NIRF imaging showed that neutrophils started to accumulate immediately after tMCAO, peaking at 18 h, and were still visible until 48 h after reperfusion. Our data revealed accumulation of neutrophils also in extracranial tissue, indicating damage in the external carotid artery territory in the tMCAO model. Antibody-mediated inhibition of α4-integrins did reduce fluorescence signals at 18 and 24, but not at 48 h after reperfusion, compared with control treatment animals. Antibody treatment reduced cerebral lesion volumes by 19%. In conclusion, the non-invasive nature of NIRF imaging allows studying the dynamics of neutrophil recruitment and its modulation by targeted interventions in the mouse brain after transient experimental cerebral ischaemia.

Non-invasive near-infrared fluorescence imaging of the neutrophil response in a mouse model of transient cerebral ischaemia

PubMed Central

Vaas, Markus; Enzmann, Gaby; Perinat, Therese; Siler, Ulrich; Reichenbach, Janine; Licha, Kai; Kipar, Anja; Rudin, Markus; Engelhardt, Britta

2016-01-01

Near-infrared fluorescence (NIRF) imaging enables non-invasive monitoring of molecular and cellular processes in live animals. Here we demonstrate the suitability of NIRF imaging to investigate the neutrophil response in the brain after transient middle cerebral artery occlusion (tMCAO). We established procedures for ex vivo fluorescent labelling of neutrophils without affecting their activation status. Adoptive transfer of labelled neutrophils in C57BL/6 mice before surgery resulted in higher fluorescence intensities over the ischaemic hemisphere in tMCAO mice with NIRF imaging when compared with controls, corroborated by ex vivo detection of labelled neutrophils using fluorescence microscopy. NIRF imaging showed that neutrophils started to accumulate immediately after tMCAO, peaking at 18 h, and were still visible until 48 h after reperfusion. Our data revealed accumulation of neutrophils also in extracranial tissue, indicating damage in the external carotid artery territory in the tMCAO model. Antibody-mediated inhibition of α4-integrins did reduce fluorescence signals at 18 and 24, but not at 48 h after reperfusion, compared with control treatment animals. Antibody treatment reduced cerebral lesion volumes by 19%. In conclusion, the non-invasive nature of NIRF imaging allows studying the dynamics of neutrophil recruitment and its modulation by targeted interventions in the mouse brain after transient experimental cerebral ischaemia. PMID:27789786

Hyperglycemia decreases expression of 14-3-3 proteins in an animal model of stroke.

PubMed

Jeon, Seong-Jun; Sung, Jin-Hee; Koh, Phil-Ok

2016-07-28

Diabetes is a severe metabolic disorder and a major risk factor for stroke. Stroke severity is worse in patients with diabetes compared to the non-diabetic population. The 14-3-3 proteins are a family of conserved acidic proteins that are ubiquitously expressed in cells and tissues. These proteins are involved in many cellular processes including metabolic pathways, signal transduction, protein trafficking, protein synthesis, and cell cycle control. This study investigated 14-3-3 proteins expression in the cerebral cortex of animals with diabetes, cerebral ischemic injury and a combination of both diabetes and cerebral ischemic injury. Diabetes was induced by intraperitoneal injection of streptozotocin (40mg/kg) in adult male rats. After 4 weeks of treatment, middle cerebral artery occlusion (MCAO) was performed for the induction of focal cerebral ischemia and cerebral cortex tissue was collected 24h after MCAO. We confirmed that diabetes increases infarct volume following MCAO compared to non-diabetic animals. In diabetic animals with MCAO injury, reduction of 14-3-3 β/α, 14-3-3 ζ/δ, 14-3-3 γ, and 14-3-3 ε isoforms was detected. The expression of these proteins was significantly decreased in diabetic animals with MCAO injury compared to diabetic-only and MCAO-only animals. Moreover, Western blot analysis ascertained the decreased expression of 14-3-3 family proteins in diabetic animals with MCAO injury, including β/α, ζ/δ, γ, ε, τ, and η isoforms. These results show the changes of 14-3-3 proteins expression in streptozotocin-induced diabetic animals with MCAO injury. Thus, these findings suggest that decreases in 14-3-3 proteins might be involved in the regulation of 14-3-3 proteins under the presence of diabetes following MCAO. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Comparison of the occlusal contact area of virtual models and actual models: a comparative in vitro study on Class I and Class II malocclusion models.

PubMed

Lee, Hyemin; Cha, Jooly; Chun, Youn-Sic; Kim, Minji

2018-06-19

The occlusal registration of virtual models taken by intraoral scanners sometimes shows patterns which seem much different from the patients' occlusion. Therefore, this study aims to evaluate the accuracy of virtual occlusion by comparing virtual occlusal contact area with actual occlusal contact area using a plaster model in vitro. Plaster dental models, 24 sets of Class I models and 20 sets of Class II models, were divided into a Molar, Premolar, and Anterior group. The occlusal contact areas calculated by the Prescale method and the virtual occlusion by scanning method were compared, and the ratio of the molar and incisor area were compared in order to find any particular tendencies. There was no significant difference between the Prescale results and the scanner results in both the molar and premolar groups (p = 0.083 and 0.053, respectively). On the other hand, there was a significant difference between the Prescale and the scanner results in the anterior group with the scanner results presenting overestimation of the occlusal contact points (p < 0.05). In Molars group, the regression analysis shows that the two variables express linear correlation and has a linear equation with a slope of 0.917. R 2 is 0.930. Groups of Premolars and Anteriors had a week linear relationship and greater dispersion. Difference between the actual and virtual occlusion revealed in the anterior portion, where overestimation was observed in the virtual model obtained from the scanning method. Nevertheless, molar and premolar areas showed relatively accurate occlusal contact area in the virtual model.

PD-L1 mAb Treats Ischemic Stroke by Controlling CNS Inflammation

PubMed Central

Bodhankar, Sheetal; Chen, Yingxin; Lapato, Andrew; Dotson, Abby L.; Wang, Jianming; Vandenbark, Arthur A.; Saugstad, Julie A.; Offner, Halina

2015-01-01

Background and Purpose Both pathogenic and regulatory immune processes are involved in the middle cerebral artery occlusion (MCAO) model of experimental stroke, including interactions involving the Programmed Death 1 (PD-1) receptor and its two ligands, PD-L1 and PD-L2. Although PD-1 reduced stroke severity, PD-L1 and PD-L2 appeared to play pathogenic roles, suggesting use of anti-PD-L monoclonal Ab (mAb) therapy for MCAO. Methods Male C57BL/6 mice were treated with a single dose of anti-PD-L1 mAb 4 h after MCAO and evaluated for clinical, histological and immunological changes after 96 h reperfusion. Results Blockade of the PD-L1 checkpoint using a single injection of 200μg anti-PD-L1 mAb given i.v. 4 h after occlusion significantly reduced MCAO infarct volumes and improved neurological outcomes after 96 h reperfusion. Treatment partially reversed splenic atrophy and decreased CNS infiltrating immune cells concomitant with enhanced appearance of CD8+ regulatory T cells in the lesioned CNS hemisphere. Conclusions This study demonstrates for the first time the beneficial therapeutic effects of PD-L1 checkpoint blockade on MCAO, thus validating proposed mechanisms obtained in our previous studies using PD-1 and PD-L deficient mice. These results provide strong support for use of available humanized anti-PD-L1 antibodies for treatment of human stroke subjects. PMID:26306753

Immune cell infiltration in malignant middle cerebral artery infarction: comparison with transient cerebral ischemia

PubMed Central

Chu, Hannah X; Kim, Hyun Ah; Lee, Seyoung; Moore, Jeffrey P; Chan, Christopher T; Vinh, Antony; Gelderblom, Mathias; Arumugam, Thiruma V; Broughton, Brad RS; Drummond, Grant R; Sobey, Christopher G

2014-01-01

We tested whether significant leukocyte infiltration occurs in a mouse model of permanent cerebral ischemia. C57BL6/J male mice underwent either permanent (3 or 24 hours) or transient (1 or 2 hours+22- to 23-hour reperfusion) middle cerebral artery occlusion (MCAO). Using flow cytometry, we observed ∼15,000 leukocytes (CD45+high cells) in the ischemic hemisphere as early as 3 hours after permanent MCAO (pMCAO), comprising ∼40% lymphoid cells and ∼60% myeloid cells. Neutrophils were the predominant cell type entering the brain, and were increased to ∼5,000 as early as 3 hours after pMCAO. Several cell types (monocytes, macrophages, B lymphocytes, CD8+ T lymphocytes, and natural killer cells) were also increased at 3 hours to levels sustained for 24 hours, whereas others (CD4+ T cells, natural killer T cells, and dendritic cells) were unchanged at 3 hours, but were increased by 24 hours after pMCAO. Immunohistochemical analysis revealed that leukocytes typically had entered and widely dispersed throughout the parenchyma of the infarct within 3 hours. Moreover, compared with pMCAO, there were ∼50% fewer infiltrating leukocytes at 24 hours after transient MCAO (tMCAO), independent of infarct size. Microglial cell numbers were bilaterally increased in both models. These findings indicate that a profound infiltration of inflammatory cells occurs in the brain early after focal ischemia, especially without reperfusion. PMID:24326388

A neural model of visual figure-ground segregation from kinetic occlusion.

PubMed

Barnes, Timothy; Mingolla, Ennio

2013-01-01

Freezing is an effective defense strategy for some prey, because their predators rely on visual motion to distinguish objects from their surroundings. An object moving over a background progressively covers (deletes) and uncovers (accretes) background texture while simultaneously producing discontinuities in the optic flow field. These events unambiguously specify kinetic occlusion and can produce a crisp edge, depth perception, and figure-ground segmentation between identically textured surfaces--percepts which all disappear without motion. Given two abutting regions of uniform random texture with different motion velocities, one region appears to be situated farther away and behind the other (i.e., the ground) if its texture is accreted or deleted at the boundary between the regions, irrespective of region and boundary velocities. Consequently, a region with moving texture appears farther away than a stationary region if the boundary is stationary, but it appears closer (i.e., the figure) if the boundary is moving coherently with the moving texture. A computational model of visual areas V1 and V2 shows how interactions between orientation- and direction-selective cells first create a motion-defined boundary and then signal kinetic occlusion at that boundary. Activation of model occlusion detectors tuned to a particular velocity results in the model assigning the adjacent surface with a matching velocity to the far depth. A weak speed-depth bias brings faster-moving texture regions forward in depth in the absence of occlusion (shearing motion). These processes together reproduce human psychophysical reports of depth ordering for key cases of kinetic occlusion displays. Copyright © 2012 Elsevier Ltd. All rights reserved.

Dynamics of myelin content decrease in the rat stroke model

NASA Astrophysics Data System (ADS)

Kisel, A.; Khodanovich, M.; Atochin, D.; Mustafina, L.; Yarnykh, V.

2017-08-01

The majority of studies were usually focused on neuronal death after brain ischemia; however, stroke affects all cell types including oligodendrocytes that form myelin sheath in the CNS. Our study is focused on the changes of myelin content in the ischemic core and neighbor structures in early terms (1, 3 and 10 days) after stroke. Stroke was modeled with middle cerebral artery occlusion (MCAo) in 15 male rats that were divided into three groups by time points after operation. Brain sections were histologically stained with Luxol Fast Blue (LFB) for myelin quantification. The significant demyelination was found in the ischemic core, corpus callosum, anterior commissure, whereas myelin content was increased in caudoputamen, internal capsule and piriform cortex compared with the contralateral hemisphere. The motor cortex showed a significant increase of myelin content on the 1st day and a significant decrease on the 3rd and 10th days after MCAo. These results suggest that stroke influences myelination not only in the ischemic core but also in distant structures.

Biochemical and inflammatory biomarkers in ischemic stroke: translational study between humans and two experimental rat models

PubMed Central

2014-01-01

Background our objective was to examine the plasma levels of three biological markers involved in cerebral ischemia (IL-6, glutamate and TNF-alpha) in stroke patients and compare them with two different rat models of focal ischemia (embolic stroke model- ES and permanent middle cerebral artery occlusion ligation model-pMCAO) to evaluate which model is most similar to humans. Secondary objectives: 1) to analyze the relationship of these biological markers with the severity, volume and outcome of the brain infarction in humans and the two stroke models; and 2) to study whether the three biomarkers are also increased in response to damage in organs other than the central nervous system, both in humans and in rats. Methods Multi-center, prospective, case-control study including acute stroke patients (n = 58) and controls (n = 19) with acute non-neurological diseases Main variables: plasma biomarker levels on admission and at 72 h; stroke severity (NIHSS scale) and clinical severity (APACHE II scale); stroke volume; functional status at 3 months (modified Rankin Scale [mRS] and Barthel index [BI]). Experimental groups: ES (n = 10), pMCAO (n = 6) and controls (tissue stress by leg compression) (n = 6). Main variables: plasma biomarker levels at 3 and 72 h; volume of ischemic lesion (H&E) and cell death (TUNEL). Results in stroke patients, IL-6 correlated significantly with clinical severity (APACHE II scale), stroke severity (NIHSS scale), infarct volume (cm3) and clinical outcome (mRS) (r = 0.326, 0.497, 0.290 and 0.444 respectively; P < 0.05). Glutamate correlated with stroke severity, but not with outcome, and TNF-alpha levels with infarct volume. In animals, The ES model showed larger infarct volumes (median 58.6% vs. 29%, P < 0.001) and higher inflammatory biomarkers levels than pMCAO, except for serum glutamate levels which were higher in pMCAO. The ES showed correlations between the biomarkers and cell death (r = 0.928 for IL-6

Indian Ginseng (Withania somnifera) supplementation ameliorates oxidative stress and mitochondrial dysfunctions in experimental model of stroke.

PubMed

Sood, Abhilasha; Mehrotra, Arpit; Dhawan, Devinder K; Sandhir, Rajat

2018-04-18

Stroke is an increasingly prevalent clinical condition and second leading cause of death globally. The present study evaluated the therapeutic potential of Indian Ginseng, also known as Withania somnifera (WS), supplementation on middle cerebral artery occlusion (MCAO) induced mitochondrial dysfunctions in experimental model of ischemic stroke. Stroke was induced in animals by occluding the middle cerebral artery, followed by reperfusion injury. Ischemia reperfusion injury resulted in increased oxidative stress indicated by increased reactive oxygen species and protein carbonyl levels; compromised antioxidant system; in terms of reduced superoxide dismutase and catalase activity, along with reduction in GSH levels and the redox ratio, impaired mitochondrial functions and enhanced expression of apoptosis markers. Ischemia reperfusion injury induced mitochondrial dysfunctions in terms of (i) reduced activity of the mitochondrial respiratory chain enzymes, (ii) reduced histochemical staining of complex-II and IV, (iii) reduced in-gel activity of mitochondrial complex-I to V, (iv) mitochondrial structural changes in terms of increased mitochondrial swelling, reduced mitochondrial membrane potential and ultrastructural changes. Additionally, an increase in the activity of caspase-3 and caspase-9 was also observed, along with altered expression of apoptotic proteins Bcl-2 and Bax in MCAO animals. MCAO animals also showed significant impairment in cognitive functions assessed using Y maze test. WS pre-supplementation, on the other hand ameliorated MCAO induced oxidative stress, mitochondrial dysfunctions, apoptosis and cognitive impairments. The results show protective effect of WS pre-supplementation in ischemic stroke and are suggestive of its potential application in stroke management.

Effect of activation of the Ca(2+)-permeable acid-sensing ion channel 1a on focal cerebral ischemia in diabetic rats.

PubMed

Wang, Jie; Wen, Chun-Yan; Cui, Cui-Cui; Xing, Ying

2015-01-01

We investigated the role of acid-sensing ion channel Ia (ASIC1a) expression and changes in intracellular Ca(2+) concentration ([Ca(2+)]) in focal cerebral ischemia after middle cerebral artery occlusion (MCAO) in a rat model of diabetes mellitus (DM). Male Wistar rats (n = 108) were divided into three groups: the MCAO, DM + MCAO, and DM + MCAO + fasudil groups (n = 36 each). Samples were obtained 1, 3, 6, and 24 h after ischemia induction (n = 9). Rats in the DM + MCAO + fasudil group were treated with 1 mg/kg fasudil, a Rho-kinase inhibitor, by caudal vein injection 30 min after MCAO was performed. ASIC1a expression gradually increased with time in the MCAO and DM + MCAO groups (0.71 ± 0.10 nM, 0.80 ± 0.11 nM, 0.86 ± 0.08 nM, 0.93 ± 0.09 nM; 0.86 ± 0.11 nM, 1.05 ± 0.51 nM, 2.42 ± 0.08 nM, 2.78 ± 0.04 nM; pairwise comparisons at each time point, P < 0.05), and was higher in the DM + MCAO than the MCAO group (P < 0.05). [Ca(2+)] gradually increased in the DM + MCAO group (106.32 ± 18.6 nM, 137.84 ± 14.32 nM, 151.94 ± 18.38 nM, 183.61 ± 7.96 nM, P < 0.05). ASIC1a expression and calcium currents were reduced in the DM + MCAO + fasudil group. The overload of intracellular [Ca(2+)] caused by ASIC1a activation could be one mechanism for the aggravation of focal cerebral ischemia in diabetes.

Effects of retraction force and anchorage reinforcement on occlusal force: a model study.

PubMed

Kim, MoonHee; Seol, Kyung-sim; Lee, Yoonjung; Park, Jiman; Kim, Minji; Chun, Youn-Sic

2014-10-01

The aim of this study was to investigate the effects of retraction force and anchorage reinforcement with orthodontic mini implants on occlusal force. A strain gauge was attached to the palatal surface of the maxillary right first molar on an en masse retraction model. Occlusal forces were measured from this model, according to different retraction forces that were generated by elastic chain, under varied compressive forces (simulating masticatory forces). This retraction experiment was then performed again, after using anchorage reinforcement with an orthodontic mini implant. Occlusal force decreased as retraction force increased. The decrease showed a significant difference above 150g of retraction force (P < 0.05) and was more definite under compressive force higher than 150 N (P < 0.001). After anchorage reinforcement with the orthodontic mini implant, however, occlusal force did not significantly decrease with increasing retraction force. Significant differences in occlusal force were noted between the conditions with and without anchorage reinforcement when the applied retraction force was greater than 200g. Occlusal force tends to decrease during retraction, and this decrease can be prevented by anchorage reinforcement with orthodontic mini implants. Further investigation on the actual masticatory process in humans is required for more clear clinical implication. © The Author 2013. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Identification of proteins in hyperglycemia and stroke animal models.

PubMed

Sung, Jin-Hee; Shah, Fawad-Ali; Gim, Sang-Ah; Koh, Phil-Ok

2016-01-01

Stroke is a major cause of disability and death in adults. Diabetes mellitus is a metabolic disorder that strongly increases the risk of severe vascular diseases. This study compared changes in proteins of the cerebral cortex during ischemic brain injury between nondiabetic and diabetic animals. Adult male rats were injected with streptozotocin (40 mg/kg) via the intraperitoneal route to induce diabetes and underwent surgical middle cerebral artery occlusion (MCAO) 4 wk after streptozotocin treatment. Cerebral cortex tissues were collected 24 h after MCAO and cerebral cortex proteins were analyzed by two-dimensional gel electrophoresis and mass spectrometry. Several proteins were identified as differentially expressed between nondiabetic and diabetic animals. Among the identified proteins, we focused on the following metabolism-related enzymes: isocitrate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, adenosylhomocysteinase, pyruvate kinase, and glucose-6-phosphate isomerase (neuroleukin). Expression of these proteins was decreased in animals that underwent MCAO. Moreover, protein expression was reduced to a greater extent in diabetic animals than in nondiabetic animals. Reverse transcription-polymerase chain reaction analysis confirmed that the diabetic condition exacerbates the decrease in expression of metabolism-related proteins after MCAO. These results suggest that the diabetic condition may exacerbate brain damage during focal cerebral ischemia through the downregulation of metabolism-related proteins. Copyright © 2016 Elsevier Inc. All rights reserved.

Perillyl alcohol improves functional and histological outcomes against ischemia-reperfusion injury by attenuation of oxidative stress and repression of COX-2, NOS-2 and NF-κB in middle cerebral artery occlusion rats.

PubMed

Tabassum, Rizwana; Vaibhav, Kumar; Shrivastava, Pallavi; Khan, Andleeb; Ahmed, Mohd Ejaz; Ashafaq, Mohammad; Khan, M Badruzzaman; Islam, Farah; Safhi, Mohammed M; Islam, Fakhrul

2015-01-15

Perillyl alcohol (PA) is a monoterpene found in essential oils of mints, cherries, citreous fruits and lemon grass, reported to have antioxidant and anti-inflammatory properties. However, the role of PA in stroke is still illusive. Since oxidative stress and inflammation play a pivotal role in ischemia-reperfusion (I-R) injury, this study was designed to elucidate the potential effects of PA against I-R induced pathology in rat׳s brain. Middle cerebral artery occlusion (MCAO) for 2h followed by 22h reperfusion in Wistar male rats (250-280g, 14-16 weeks old) induced the behavioral and histological alterations along with exhausted antioxidant status and enhanced inflammatory mediators. However, PA administration (25, 50 and 100mg/kg b.wt orally once daily for 7 days) prior to MCAO significantly attenuated neurological deficits related to flexion test and spontaneous motor activity, improved grip strength and motor coordination in a dose dependent manner. PA treatment also inhibited oxidative stress in MCAO rats as evident from decreased lipid peroxidation and augmented level of reduced glutathione and restored activities of catalase, glutathione peroxidase, and glutathione reductase and thus, reduced infarct volume and protected the brain histology after I-R injury. Furthermore, PA markedly suppressed the level of proinflammatory cytokines (IL-1β, TNF α and IL-6) and down regulated expressions of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (NOS-2) and nuclear factor κB (NF-κB) in MCAO group. In conclusion, PA mediates neuroprotection against I-R injury via mitigation of oxidative stress and inflammation and thus, may be a good therapeutic approach in stroke prone patient. Copyright © 2014 Elsevier B.V. All rights reserved.

Korean red ginseng protects against neuronal damage induced by transient focal ischemia in rats

PubMed Central

BAN, JU YEON; KANG, SUNG WOOK; LEE, JONG SEOK; CHUNG, JOO-HO; KO, YOUNG GWAN; CHOI, HAN SUNG

2012-01-01

In the present study, we investigated the neuroprotective effect of Korean red ginseng (KRG) following focal brain ischemia/reperfusion injury, in relation to its antioxidant activities. The middle cerebral artery occlusion/reperfusion (MCAO/R) model in rats was employed. The KRG extract (100 mg/kg, perorally) was administered once daily for 7 days following MCAO/R. The elevated levels of lipid peroxidation in the MCAO/R group were attenuated significantly in the KRG-administered group. The significantly depleted activity of the antioxidant enzymes glutathione peroxidase, superoxide dismutase and catalase was prevented in the KRG-administered group. In the neurobehavioral evaluation expressed as the modified neurological severity score and corner-turn test, the daily intake of KRG showed consistent and significant improvement in the neurological deficits for 7 days following MCAO/R injury. These results indicate that KRG has a neuroprotective effect against ischemia/reperfusion brain injury by reducing the level of lipid peroxidation and increasing the endogenous antioxidant enzymatic activity. PMID:22969953

Animal models of ischemic stroke and their application in clinical research.

PubMed

Fluri, Felix; Schuhmann, Michael K; Kleinschnitz, Christoph

2015-01-01

This review outlines the most frequently used rodent stroke models and discusses their strengths and shortcomings. Mimicking all aspects of human stroke in one animal model is not feasible because ischemic stroke in humans is a heterogeneous disorder with a complex pathophysiology. The transient or permanent middle cerebral artery occlusion (MCAo) model is one of the models that most closely simulate human ischemic stroke. Furthermore, this model is characterized by reliable and well-reproducible infarcts. Therefore, the MCAo model has been involved in the majority of studies that address pathophysiological processes or neuroprotective agents. Another model uses thromboembolic clots and thus is more convenient for investigating thrombolytic agents and pathophysiological processes after thrombolysis. However, for many reasons, preclinical stroke research has a low translational success rate. One factor might be the choice of stroke model. Whereas the therapeutic responsiveness of permanent focal stroke in humans declines significantly within 3 hours after stroke onset, the therapeutic window in animal models with prompt reperfusion is up to 12 hours, resulting in a much longer action time of the investigated agent. Another major problem of animal stroke models is that studies are mostly conducted in young animals without any comorbidity. These models differ from human stroke, which particularly affects elderly people who have various cerebrovascular risk factors. Choosing the most appropriate stroke model and optimizing the study design of preclinical trials might increase the translational potential of animal stroke models.

Animal models of ischemic stroke and their application in clinical research

PubMed Central

Fluri, Felix; Schuhmann, Michael K; Kleinschnitz, Christoph

2015-01-01

This review outlines the most frequently used rodent stroke models and discusses their strengths and shortcomings. Mimicking all aspects of human stroke in one animal model is not feasible because ischemic stroke in humans is a heterogeneous disorder with a complex pathophysiology. The transient or permanent middle cerebral artery occlusion (MCAo) model is one of the models that most closely simulate human ischemic stroke. Furthermore, this model is characterized by reliable and well-reproducible infarcts. Therefore, the MCAo model has been involved in the majority of studies that address pathophysiological processes or neuroprotective agents. Another model uses thromboembolic clots and thus is more convenient for investigating thrombolytic agents and pathophysiological processes after thrombolysis. However, for many reasons, preclinical stroke research has a low translational success rate. One factor might be the choice of stroke model. Whereas the therapeutic responsiveness of permanent focal stroke in humans declines significantly within 3 hours after stroke onset, the therapeutic window in animal models with prompt reperfusion is up to 12 hours, resulting in a much longer action time of the investigated agent. Another major problem of animal stroke models is that studies are mostly conducted in young animals without any comorbidity. These models differ from human stroke, which particularly affects elderly people who have various cerebrovascular risk factors. Choosing the most appropriate stroke model and optimizing the study design of preclinical trials might increase the translational potential of animal stroke models. PMID:26170628

Optimization of a therapeutic protocol for intravenous injection of human mesenchymal stem cells after cerebral ischemia in adult rats.

PubMed

Omori, Yoshinori; Honmou, Osamu; Harada, Kuniaki; Suzuki, Junpei; Houkin, Kiyohiro; Kocsis, Jeffery D

2008-10-21

The systemic injection of human mesenchymal stem cells (hMSCs) prepared from adult bone marrow has therapeutic benefits after cerebral artery occlusion in rats, and may have multiple therapeutic effects at various sites and times within the lesion as the cells respond to a particular pathological microenvironment. However, the comparative therapeutic benefits of multiple injections of hMSCs at different time points after cerebral artery occlusion in rats remain unclear. In this study, we induced middle cerebral artery occlusion (MCAO) in rats using intra-luminal vascular occlusion, and infused hMSCs intravenously at a single 6 h time point (low and high cell doses) and various multiple time points after MCAO. From MRI analyses lesion volume was reduced in all hMSC cell injection groups as compared to serum alone injections. However, the greatest therapeutic benefit was achieved following a single high cell dose injection at 6 h post-MCAO, rather than multiple lower cell infusions over multiple time points. Three-dimensional analysis of capillary vessels in the lesion indicated that the capillary volume was equally increased in all of the cell-injected groups. Thus, differences in functional outcome in the hMSC transplantation subgroups are not likely the result of differences in angiogenesis, but rather from differences in neuroprotective effects.

Effect of activation of the Ca2+-permeable acid-sensing ion channel 1a on focal cerebral ischemia in diabetic rats

PubMed Central

Wang, Jie; Wen, Chun-Yan; Cui, Cui-Cui; Xing, Ying

2015-01-01

We investigated the role of acid-sensing ion channel Ia (ASIC1a) expression and changes in intracellular Ca2+ concentration ([Ca2+]) in focal cerebral ischemia after middle cerebral artery occlusion (MCAO) in a rat model of diabetes mellitus (DM). Male Wistar rats (n = 108) were divided into three groups: the MCAO, DM + MCAO, and DM + MCAO + fasudil groups (n = 36 each). Samples were obtained 1, 3, 6, and 24 h after ischemia induction (n = 9). Rats in the DM + MCAO + fasudil group were treated with 1 mg/kg fasudil, a Rho-kinase inhibitor, by caudal vein injection 30 min after MCAO was performed. ASIC1a expression gradually increased with time in the MCAO and DM + MCAO groups (0.71 ± 0.10 nM, 0.80 ± 0.11 nM, 0.86 ± 0.08 nM, 0.93 ± 0.09 nM; 0.86 ± 0.11 nM, 1.05 ± 0.51 nM, 2.42 ± 0.08 nM, 2.78 ± 0.04 nM; pairwise comparisons at each time point, P < 0.05), and was higher in the DM + MCAO than the MCAO group (P < 0.05). [Ca2+] gradually increased in the DM + MCAO group (106.32 ± 18.6 nM, 137.84 ± 14.32 nM, 151.94 ± 18.38 nM, 183.61 ± 7.96 nM, P < 0.05). ASIC1a expression and calcium currents were reduced in the DM + MCAO + fasudil group. The overload of intracellular [Ca2+] caused by ASIC1a activation could be one mechanism for the aggravation of focal cerebral ischemia in diabetes. PMID:26722526

A novel indication of platonin, a therapeutic immunomodulating medicine, on neuroprotection against ischemic stroke in mice

PubMed Central

Sheu, Joen-Rong; Chen, Zhih-Cherng; Jayakumar, Thanasekaran; Chou, Duen-Suey; Yen, Ting-Lin; Lee, Hsing-Ni; Pan, Szu-Han; Hsia, Chih-Hsuan; Yang, Chih-Hao; Hsieh, Cheng-Ying

2017-01-01

Thrombosis and stroke are major causes of disability and death worldwide. However, the regular antithrombotic drugs may have unsatisfactory results and side effects. Platonin, a cyanine photosensitizing dye, has been used to treat trauma, ulcers and some acute inflammation. Here, we explored the neuroprotective effects of platonin against middle cerebral artery occlusion (MCAO)-induced ischemic stroke in mice. Platonin(200 μg/kg) substantially reduced cerebral infarct volume, brain edema, neuronal cell death and neurological deficit scores, and improved the MCAO-reduced locomotor activity and rotarod performance. Platonin(5–10 μM) potently inhibited platelet aggregation and c-Jun NH2-terminal kinase (JNK) phosphorylation in collagen-activated platelets. The antiaggregation effect did not affect bleeding time but increased occlusion time in platonin(100 and 200 μg/kg)-treated mice. Platonin(2–10 μM) was potent in diminishing collagen- and Fenton reaction-induced ∙OH formation. Platonin(5–10 μM) also suppressed the expression of nitric oxide, inducible nitric oxide synthase, cyclooxygenase-2, interleukin-1β, and JNK phosphorylation in lipopolysaccharide-stimulated macrophages. MCAO-induced expression of 3-nitrotyrosine and Iba1 was apparently attenuated in platonin(200 μg/kg)-treated mice. In conclusion, platonin exhibited remarkable neuroprotective properties against MCAO-induced ischemia in a mouse model through its antiaggregation, antiinflammatory and antiradical properties. The observed therapeutic efficacy of platonin may consider being a novel medcine against ischemic stroke. PMID:28165057

Optimization of the static occlusion by "occlusal surface settling" in the Cerec 3D software.

PubMed

Späth, C; Kordass, B

2006-04-01

The adjustment of the static occlusion can be automated in computer-based systems. The Cerec 3D software makes it possible to take preformed occlusal surfaces from a database and adapt them to the antagonist. In this adaptation (settling), the CAD occlusal surface "settles" as whole or each cusp individually into the occlusal surface of the antagonist until stable occlusion is reached. Two occlusal surface shapes were compared: Vita Physiodens and Lee Culp. An index was formed from the number, quality, and position of the occlusal contacts for 35 model cases (25 molars, 10 premolars). With regard to the settling of the total occlusal surfaces, there were no differences between the two occlusal surface shapes. In "cusp settling" of the molars, Vita Physiodens performed significantly better. In the comparison of the 1st with the 3rd settling process, significant improvements occurred the 3rd time in many cases when settling individual cusps, but in clearly fewer cases in the settling process of the total occlusal surface. The Lee Culp tooth occlusion improved especially after the 3rd settling process of individual cusps. It is therefore expedient to combine both settling versions with one another.

RANKL, Osteopontin, and Osteoclast Homeostasis in a Hyper-Occlusion Mouse Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walker, Cameron G.; Ito, Yoshihiro; Dangaria, Smit

2010-11-15

The biological mechanisms that maintain the position of teeth in their sockets establish a dynamic equilibrium between bone resorption and apposition. In order to reveal some of the dynamics involved in the tissue responses towards occlusal forces on periodontal ligament (PDL) and alveolar bone homeostasis, we developed the first mouse model of hyperocclusion. Swiss-Webster mice were kept in hyperocclusion for 0, 3, 6, and 9 d. Morphological and histological changes in the periodontium were assessed using micro-computed tomography (micro-CT) and ground sections with fluorescent detection of vital dye labels. Sections were stained for tartrate-resistant acid phosphatase, and the expression ofmore » receptor activator of nuclear factor-{kappa}B ligand (RANKL) and osteopontin (OPN) was analyzed by immunohistochemistry and real-time polymerase chain reaction (PCR). Traumatic occlusion resulted in enamel surface abrasion, inhibition of alveolar bone apposition, significant formation of osteoclasts at 3, 6 and 9 d, and upregulation of OPN and RANKL. Data from this study suggest that both OPN and RANKL contribute to the stimulation of bone resorption in the hyperocclusive state. In addition, we propose that the inhibition of alveolar bone apposition by occlusal forces is an important mechanism for the control of occlusal height that might work in synergy with RANKL-induced bone resorption to maintain normal occlusion.« less

Swine Model of Thrombotic Caval Occlusion Created by Autologous Thrombus Injection with Assistance of Intra-caval Net Knitting

PubMed Central

Shi, Wan-Yin; Wu, Shuang; Hu, Lan-Yue; Liu, Chang-Jian; Gu, Jian-Ping

2015-01-01

To evaluate the feasibility of a swine model of thrombotic inferior vena cava (IVC) occlusion (IVCO) created by autologous thrombus injection with assistance of intra-caval net knitting. Sixteen pigs were included and divided into two groups: Group A (n = 10), IVCO model created by knitting a caval net followed by autologous thrombus injection; Group B (n = 6), control model created by knitting a net and normal saline injection. Venography was performed to assess each model and the associated thrombotic occlusion. The vessels were examined histologically to analyse the pathological changes postoperatively. IVCO model was successfully created in 10 animals in Group A (100%). Immediate venography showed extensive clot burden in the IVC. Postoperative venography revealed partial caval occlusion at 7 days, and complete occlusion coupled with collateral vessels at 14 days. Histologically, Group A animals had significantly greater venous wall thickening, with CD163-positive and CD3-positive cell infiltration. Recanalization channels were observed at the margins of the thrombus. By contrast, no thrombotic occlusion of the IVC was observed in Group B. The thrombotic IVCO model can be reliably established in swine. The inflammatory reaction may contribute to the caval thrombus propagation following occlusion. PMID:26680253

EMBOLIC MIDDLE CEREBRAL ARTERY OCCLUSION MODEL USING THROMBIN AND FIBRINOGEN COMPOSED CLOTS IN RAT

PubMed Central

Ren, Ming; Lin, Zi-Jing; Qian, Hai; Gourav, Choudhury Roy; liu, Ran; Liu, Hanli; Yang, Shao-Hua

2012-01-01

Ischemic stroke accounts for over 80% in total human stroke which mostly affect middle cerebral artery (MCA) territory. Embolic stroke models induced by injection of homologous clots into the internal carotid artery and MCA closely mimic human stroke and have been commonly used in stroke research. Studies indicate that the size and composition of clots are critical for the reproducibility of the stroke model. In the present study, we modified the homologous clots formation by addition of thrombin and fibrinogen which produced even distribution of fibrin with tight cross linkage of red blood cells. We optimized the embolic MCA occlusion model in rats using different size of the mixed clots. A precise lodgment of the clots at the MCA bifurcation and highly reproducible ischemic lesion in the MCA territory were demonstrated in the embolic MCA occlusion model induced by injection of 10 pieces of 1-mm long mixed clots made in PE-60 catheter. We further tested the effect of recombinant tissue plasminogen activator (rtPA) in this embolic MCA occlusion model. rtPA induced thrombolysis, improved neurological outcome, and significantly reduced ischemic lesion volume when administered at 1 hour after embolism as compared with control. In summary, we have established a reproducible embolic MCA occlusion model using clots made of homologous blood, thrombin and fibrinogen. The mixed clots enable precise lodgment at the MCA bifurcation which is responsive to thrombolytic therapy of rtPA. PMID:22985597

Embolic middle cerebral artery occlusion model using thrombin and fibrinogen composed clots in rat.

PubMed

Ren, Ming; Lin, Zi-Jing; Qian, Hai; Choudhury, Gourav Roy; Liu, Ran; Liu, Hanli; Yang, Shao-Hua

2012-11-15

Ischemic stroke accounts for over 80% in total human stroke which mostly affect middle cerebral artery (MCA) territory. Embolic stroke models induced by injection of homologous clots into the internal carotid artery and MCA closely mimic human stroke and have been commonly used in stroke research. Studies indicate that the size and composition of clots are critical for the reproducibility of the stroke model. In the present study, we modified the homologous clots formation by addition of thrombin and fibrinogen which produced even distribution of fibrin with tight cross linkage of red blood cells. We optimized the embolic MCA occlusion model in rats using different size of the mixed clots. A precise lodgment of the clots at the MCA bifurcation and highly reproducible ischemic lesion in the MCA territory were demonstrated in the embolic MCA occlusion model induced by injection of 10 pieces of 1-mm long mixed clots made in PE-60 catheter. We further tested the effect of recombinant tissue plasminogen activator (rtPA) in this embolic MCA occlusion model. rtPA induced thrombolysis, improved neurological outcome, and significantly reduced ischemic lesion volume when administered at 1h after embolism as compared with control. In summary, we have established a reproducible embolic MCA occlusion model using clots made of homologous blood, thrombin and fibrinogen. The mixed clots enable precise lodgment at the MCA bifurcation which is responsive to thrombolytic therapy of rtPA. Copyright © 2012 Elsevier B.V. All rights reserved.

A Magnetic Microbead Occlusion Model to Induce Ocular Hypertension-Dependent Glaucoma in Mice

PubMed Central

Cueva Vargas, Jorge L.; Di Polo, Adriana

2016-01-01

The use of rodent models of glaucoma has been essential to understand the molecular mechanisms that underlie the pathophysiology of this multifactorial neurodegenerative disease. With the advent of numerous transgenic mouse lines, there is increasing interest in inducible murine models of ocular hypertension. Here, we present an occlusion model of glaucoma based on the injection of magnetic microbeads into the anterior chamber of the eye using a modified microneedle with a facetted bevel. The magnetic microbeads are attracted to the iridocorneal angle using a handheld magnet to block the drainage of aqueous humour from the anterior chamber. This disruption in aqueous dynamics results in a steady elevation of intraocular pressure, which subsequently leads to the loss of retinal ganglion cells, as observed in human glaucoma patients. The microbead occlusion model presented in this manuscript is simple compared to other inducible models of glaucoma and also highly effective and reproducible. Importantly, the modifications presented here minimize common issues that often arise in occlusion models. First, the use of a bevelled glass microneedle prevents backflow of microbeads and ensures that minimal damage occurs to the cornea during the injection, thus reducing injury-related effects. Second, the use of magnetic microbeads ensures the ability to attract most beads to the iridocorneal angle, effectively reducing the number of beads floating in the anterior chamber avoiding contact with other structures (e.g., iris, lens). Lastly, the use of a handheld magnet allows flexibility when handling the small mouse eye to efficiently direct the magnetic microbeads and ensure that there is little reflux of the microbeads from the eye when the microneedle is withdrawn. In summary, the microbead occlusion mouse model presented here is a powerful investigative tool to study neurodegenerative changes that occur during the onset and progression of glaucoma. PMID:27077732

Relationship between aneurysm occlusion and flow diverting device oversizing in a rabbit model.

PubMed

Hodis, Simona; Ding, Yong-Hong; Dai, Daying; Lingineni, Ravi; Mut, Fernando; Cebral, Juan; Kallmes, David; Kadirvel, Ramanathan

2016-01-01

Implanted, actual flow diverter pore density is thought to be strongly influenced by proper matching between the device size and parent artery diameter. The objective of this study was to characterize the correlation between device sizing, metal coverage, and the resultant occlusion of aneurysms following flow diverter treatment in a rabbit model. Rabbit saccular aneurysms were treated with flow diverters (iso-sized to proximal parent artery, 0.5 mm oversized, or 1.0 mm oversized, respectively, n=6 for each group). Eight weeks after implantation, the angiographic degree of aneurysm occlusion was graded (complete, near-complete, or incomplete). The ostium of the explanted aneurysm covered with the flow diverter struts was photographed. Based on gross anatomic findings, the metal coverage and pore density at the ostium of the aneurysm were calculated and correlated with the degree of aneurysm occlusion. Angiographic results showed there were no statistically significant differences in aneurysm geometry and occlusion among groups. The mean parent artery diameter to flow diverter diameter ratio was higher in the 1.0 mm oversized group than in the other groups. Neither the percentage metal coverage nor the pore density showed statistically significant differences among groups. Aneurysm occlusion was inversely correlated with the ostium diameter, irrespective of the size of the device implanted. Device sizing alone does not predict resultant pore density or metal coverage following flow diverter implantation in the rabbit aneurysm model. Aneurysm occlusion was not impacted by either metal coverage or pore density, but was inversely correlated with the diameter of the ostium. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

MRI Features in a Canine Model of Ischemic Stroke: Correlation between Lesion Volume and Neurobehavioral Status during the Subacute Stage

PubMed Central

Kang, Byeong-Teck; Jang, Dong-Pyo; Gu, Su-Hyun; Lee, Jong-Hwan; Jung, Dong-In; Lim, Chae-Young; Kim, Ha-Jung; Kim, Young-Bo; Kim, Hyung-Joong; Woo, Eung-Je; Cho, Zang-Hee; Park, Hee-Myung

2009-01-01

The purpose of this study was to evaluate the diagnostic value of magnetic resonance imaging (MRI) and assess the correlation between the volume of the ischemic lesion and neurobehavioral status during the subacute stage of ischemic stroke. Ischemic stroke was induced in 6 healthy laboratory beagles through permanent occlusion of the middle cerebral artery (MCAO). T2-weighted and fluid-attenuated inversion recovery (FLAIR) imaging, diffusion-weighted imaging (DWI), measurement of the apparent diffusion coefficient (ADC) ratio, and neurobehavioral evaluation were performed 3 times serially by using a 1.5-T MR system: before and 3 and 10 d after MCAO. Ischemic lesions demonstrated T2 hyperintensity, FLAIR hyperintensity, and DWI hyperintensity. The ADC ratio was decreased initially but then was increased at 10 d after MCAO. Ischemic lesion volumes on T2-weighted and FLAIR imaging were not significantly different from those on DWI. The lesion volume and neurobehavioral score showed strong correlation. Our results suggest that conventional MRI may be a reliable diagnostic tool during the subacute stage of canine ischemic stroke. PMID:19887030

Application of photogrammetry for analysis of occlusal contacts.

PubMed

Shigeta, Yuko; Hirabayashi, Rio; Ikawa, Tomoko; Kihara, Takuya; Ando, Eriko; Hirai, Shinya; Fukushima, Shunji; Ogawa, Takumi

2013-04-01

The conventional 2D-analysis methods for occlusal contacts provided limited information on tooth morphology. This present study aims to detect 3D positional information of occlusal contacts from 2D-photos via photogrammetry. We propose an image processing solution for analysis of occlusal contacts and facets via the black silicone method and a photogrammetric technique. The occlusal facets were reconstructed from a 2D-photograph data-set of inter-occlusal records into a 3D image via photogrammetry. The configuration of the occlusal surface was reproduced with polygons. In addition, the textures of the occlusal contacts were mapped to each polygon. DIFFERENCE FROM CONVENTIONAL METHODS: Constructing occlusal facets with 3D polygons from 2D-photos with photogrammetry was a defining characteristic of this image processing technique. It allowed us to better observe findings of the black silicone method. Compared with conventional 3D analysis using a 3D scanner, our 3D models did not reproduce the detail of the anatomical configuration. However, by merging the findings of the inter-occlusal record, the deformation of mandible and the displacement of periodontal ligaments under occlusal force were reflected in our model. EFFECT OR PERFORMANCE: Through the use of polygons in the conversion of 2D images to 3D images, we were able to define the relation between the location and direction of the occlusal contacts and facets, which was difficult to detect via conventional methods. Through our method of making a 3D polygon model, the findings of inter-occlusal records which reflected the jaw/teeth behavior under occlusal force could be observed 3-dimensionally. Copyright © 2012 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

[Relationship between Occlusal Discomfort Syndrome and Occlusal Threshold].

PubMed

Munakata, Motohiro; Ono, Yumie; Hayama, Rika; Kataoka, Kanako; Ikuta, Ryuhei; Tamaki, Katsushi

2016-03-01

Occlusal dysesthesia has been defined as persistent uncomfortable feelings of intercuspal position continuing for more than 6 months without evidence of physical occlusal discrepancy. The problem often occurs after occlusal intervention by dental care. Although various dental treatments (e. g. occlusal adjustment, orthodontic treatment and prosthetic reconstruction) are attempted to solve occlusal dysesthesia, they rarely reach a satisfactory result, neither for patients nor dentists. In Japan, these symptoms are defined by the term "Occlusal discomfort syndrome" (ODS). The aim of this study was to investigate the characteristics of ODS with the simple occlusal sensory perceptive and discriminative test. Twenty-one female dental patients with ODS (mean age 55.8 ± 19.2 years) and 21 age- and gender-matched dental patients without ODS (mean age 53.1 ± 16.8 years) participated in the study. Upon grinding occlusal registration foils that were stacked to different thicknesses, participants reported the thicknesses at which they recognized the foils (recognition threshold) and felt discomfort (discomfort threshold). Although there was no significant difference in occlusal recognition thresholds between the two patient groups, the discomfort threshold was significantly smaller in the patients with ODS than in those without ODS. Moreover, the recognition threshold showed an age-dependent increase in patients without ODS, whereas it remained comparable between the younger (< 60 years old) and elderly (60 years old or more) patient subgroups with ODS. These results suggest that occlusal discomfort threshold rather than recognition threshold is an issue in ODS. The foil grinding procedure is a simple and useful method to evaluate occlusal perceptive and discriminative abilities in patients with ODS.

Treatment of experimental stroke with IL-10-producing B-cells reduces infarct size and peripheral and CNS inflammation in wild-type B-cell-sufficient mice

PubMed Central

Bodhankar, Sheetal; Chen, Yingxin; Vandenbark, Arthur A.; Murphy, Stephanie J.; Offner, Halina

2014-01-01

Clinical stroke induces inflammatory processes leading to cerebral and splenic injury and profound peripheral immunosuppression. IL-10 expression is elevated during major CNS diseases and limits inflammation in the brain. Recent evidence demonstrated that absence of B-cells led to larger infarct volumes and CNS damage after middle cerebral artery occlusion (MCAO) that could be prevented by transfer of IL-10+ B-cells. The purpose of this study was to determine if the beneficial immunoregulatory effects on MCAO of the IL-10+ B-cell subpopulation also extends to B-cell-sufficient mice that would better represent stroke subjects. CNS inflammation and infarct volumes were evaluated in male C57BL/6J (WT) mice that received either RPMI or IL-10+ B-cells and underwent 60 min of middle cerebral artery occlusion (MCAO) followed by 96 hours of reperfusion. Transfer of IL-10+ B-cells markedly reduced infarct volume in WT recipient mice when given 24 hours prior to or 4 hours after MCAO. B-cell protected MCAO mice had increased regulatory subpopulations in the periphery, reduced numbers of activated, inflammatory T-cells, decreased infiltration of T-cells and a less inflammatory milieu in the ischemic hemispheres of the IL-10+ B-cell-treated group. Moreover, transfer of IL-10+ B-cells 24 hours before MCAO led to a significant preservation of regulatory immune subsets in the IL-10+ B-cell protected group presumably indicating their role in immunomodulatory mechanisms, post-stroke. Our studies are the first to demonstrate a major immunoregulatory role for IL-10+ regulatory B-cells in preventing and treating MCAO in WT mice and also implicating their potential role in attenuating complications due to post-stroke immunosuppression. PMID:24374817

Numeric simulation of occlusal interferences in molars restored with ultrathin occlusal veneers.

PubMed

Magne, Pascal; Cheung, Raymond

2017-01-01

Selecting material for a minimally invasive occlusal veneer reconstruction concept requires an understanding of how stresses are distributed during functional and parafunctional forces. The purpose of this in vitro study was to investigate stress distribution in a maxillary molar restored with ultrathin occlusal veneers and subjected by an antagonistic mandibular molar to clenching and working and nonworking movements. A maxillary first molar was modeled from microcomputed tomography (micro-CT) data, using medical image processing software, stereolithography editing/optimizing software, and finite element software. Simulated ultrathin occlusal veneer materials were used. The mandibular molar antagonist was a solid nondeformable geometric entity. Loads simulated clenching, working, and nonworking movements with loading of 500 N. The values of the maximum principal stress were recorded. In the clenching load situation, maximum tensile stresses were located at the occlusal veneer (52 MPa for composite resin versus 47 MPa for ceramic). In the working movement, significant additional tensile stresses were found on the palatal root (87 MPa for composite resin and 85 MPa for ceramic). In the nonworking movement, tensile stress on the ultrathin occlusal veneer increased to 118 MPa for composite resin and 143 MPa for ceramic veneers. Tensile stress peaks shifted to the mesiobuccal root (75 MPa for composite resin and 74 MPa for ceramic). The topography of stresses generated by the various occlusal interferences were clearly identified. Significant tensile stress concentrations were found within the restoration's occlusal topography and root, with the nonworking interference being the most harmful and also the most revealing of the difference between the composite resin and ceramic ultrathin occlusal veneers. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Mulberry Fruit Extract Protects against Memory Impairment and Hippocampal Damage in Animal Model of Vascular Dementia

PubMed Central

Kaewkaen, Pratchaya; Tong-un, Terdthai; Wattanathorn, Jintanaporn; Muchimapura, Supaporn; Kaewrueng, Wiroje; Wongcharoenwanakit, Sathaporn

2012-01-01

Nowadays, the preventive strategy of vascular dementia, one of the challenge problems of elderly, has received attention due to the limitation of therapeutic efficacy. In this study, we aimed to determine the protective effect and possible mechanism of action of mulberry fruit extract on memory impairment and brain damage in animal model of vascular dementia. Male Wistar rats, weighing 300–350 g, were orally given mulberry extract at doses of 2, 10 and 50 mg/kg at a period of 7 days before and 21 days after the occlusion of right middle cerebral artery (Rt.MCAO). It was found that rats subjected to mulberry fruits plus Rt.MCAO showed the enhanced memory, the increased densities of neuron, cholinergic neuron, Bcl-2-immunopositive neuron together with the decreased oxidative stress in hippocampus. Taken all data together, the cognitive enhancing effect of mulberry fruit extract observed in this study might be partly associated with the increased cholinergic function and its neuroprotective effect in turn occurs partly via the decreased oxidative stress and apoptosis. Therefore, mulberry fruit is the potential natural cognitive enhancer and neuroprotectant. However, further researches are essential to elucidate the possible active ingredient. PMID:22952555

Sustained functional improvement by hepatocyte growth factor-like small molecule BB3 after focal cerebral ischemia in rats and mice

PubMed Central

Chaparro, Rafael E; Izutsu, Miwa; Sasaki, Toshihiro; Sheng, Huaxin; Zheng, Yi; Sadeghian, Homa; Qin, Tao; von Bornstadt, Daniel; Herisson, Fanny; Duan, Bin; Li, Jing-Song; Jiang, Kai; Pearlstein, Molly; Pearlstein, Robert D; Smith, David E; Goldberg, Itzhak D; Ayata, Cenk; Warner, David S

2015-01-01

Hepatocyte growth factor (HGF), efficacious in preclinical models of acute central nervous system injury, is burdened by administration of full-length proteins. A multiinstitutional consortium investigated the efficacy of BB3, a small molecule with HGF-like activity that crosses the blood–brain barrier in rodent focal ischemic stroke using Stroke Therapy Academic Industry Roundtable (STAIR) and Good Laboratory Practice guidelines. In rats, BB3, begun 6 hours after temporary middle cerebral artery occlusion (tMCAO) reperfusion, or permanent middle cerebral artery occlusion (pMCAO) onset, and continued for 14 days consistently improved long-term neurologic function independent of sex, age, or laboratory. BB3 had little effect on cerebral infarct size and no effect on blood pressure. BB3 increased HGF receptor c-Met phosphorylation and synaptophysin expression in penumbral tissue consistent with a neurorestorative mechanism from HGF-like activity. In mouse tMCAO, BB3 starting 10 minutes after reperfusion and continued for 14 days improved neurologic function that persisted for 8 weeks in some, but not all measures. Study in animals with comorbidities and those exposed to common stroke drugs are the next steps to complete preclinical assessment. These data, generated in independent, masked, and rigorously controlled settings, are the first to suggest that the HGF pathway can potentially be harnessed by BB3 for neurologic benefit after ischemic stroke. PMID:25712497

l-Homocarnosine attenuates inflammation in cerebral ischemia-reperfusion injury through inhibition of nod-like receptor protein 3 inflammasome.

PubMed

Huang, Jing; Wang, Tao; Yu, Daorui; Fang, Xingyue; Fan, Haofei; Liu, Qiang; Yi, Guohui; Yi, Xinan; Liu, Qibin

2018-06-08

We investigated the therapeutic effects of l-homocarnosine against inflammation in a rat model of cerebral ischemia-reperfusion injury. Rats were grouped into control, middle cerebral artery occlusion (MCAO), 0.5 mM l-homocarnosine + MCAO, and 1 mM l-homocarnosine + MCAO treatment groups. Superoxide dismutase (SOD), glutathione peroxidase (Gpx), catalase, lipid peroxidation, and reduced glutathione (GSH) levels were measured. Neurological scores were assessed, and histopathology, scanning electron microscopy (SEM), and fluorescence microscopy analyses were conducted. The mRNA expression levels of nod-like receptor protein 3 (NLRP3), tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6) and protein expression levels of NLRP3 were assessed. l-Homocarnosine supplementation substantially increased SOD, catalase, Gpx, and GSH levels, whereas it reduced the levels of lipid peroxidation relative to MCAO rats. l-Homocarnosine significantly reduced the infarct area and neurological deficit score, as well as histopathological alteration, apoptosis, and necrosis in brain tissue. The mRNA expression levels of NLRP3, TNF-α, and IL-6 were increased in MCAO rats, whereas l-homocarnosine supplementation reduced mRNA expression by >40%, and NLRP3 protein expression was reduced by >30% in 1 mM l-homocarnosine-treated MCAO rats. We propose that l-homocarnosine exerts a protective effect in cerebral ischemia-reperfusion injury-induced rats by downregulating NLRP3 expression. Copyright © 2017. Published by Elsevier B.V.

Haptic simulation framework for determining virtual dental occlusion.

PubMed

Wu, Wen; Chen, Hui; Cen, Yuhai; Hong, Yang; Khambay, Balvinder; Heng, Pheng Ann

2017-04-01

The surgical treatment of many dentofacial deformities is often complex due to its three-dimensional nature. To determine the dental occlusion in the most stable position is essential for the success of the treatment. Computer-aided virtual planning on individualized patient-specific 3D model can help formulate the surgical plan and predict the surgical change. However, in current computer-aided planning systems, it is not possible to determine the dental occlusion of the digital models in the intuitive way during virtual surgical planning because of absence of haptic feedback. In this paper, a physically based haptic simulation framework is proposed, which can provide surgeons with the intuitive haptic feedback to determine the dental occlusion of the digital models in their most stable position. To provide the physically realistic force feedback when the dental models contact each other during the searching process, the contact model is proposed to describe the dynamic and collision properties of the dental models during the alignment. The simulated impulse/contact-based forces are integrated into the unified simulation framework. A validation study has been conducted on fifteen sets of virtual dental models chosen at random and covering a wide range of the dental relationships found clinically. The dental occlusions obtained by an expert were employed as a benchmark to compare the virtual occlusion results. The mean translational and angular deviations of the virtual occlusion results from the benchmark were small. The experimental results show the validity of our method. The simulated forces can provide valuable insights to determine the virtual dental occlusion. The findings of this work and the validation of proposed concept lead the way for full virtual surgical planning on patient-specific virtual models allowing fully customized treatment plans for the surgical correction of dentofacial deformities.

Dynamic Modelling of Tooth Deformation Using Occlusal Kinematics and Finite Element Analysis.

PubMed

Benazzi, Stefano; Nguyen, Huynh Nhu; Kullmer, Ottmar; Kupczik, Kornelius

2016-01-01

Dental biomechanics based on finite element (FE) analysis is attracting enormous interest in dentistry, biology, anthropology and palaeontology. Nonetheless, several shortcomings in FE modeling exist, mainly due to unrealistic loading conditions. In this contribution we used kinematics information recorded in a virtual environment derived from occlusal contact detection between high resolution models of an upper and lower human first molar pair (M1 and M1, respectively) to run a non-linear dynamic FE crash colliding test. MicroCT image data of a modern human skull were segmented to reconstruct digital models of the antagonistic right M1 and M1 and the dental supporting structures. We used the Occlusal Fingerprint Analyser software to reconstruct the individual occlusal pathway trajectory during the power stroke of the chewing cycle, which was applied in a FE simulation to guide the M1 3D-path for the crash colliding test. FE analysis results showed that the stress pattern changes considerably during the power stroke, demonstrating that knowledge about chewing kinematics in conjunction with a morphologically detailed FE model is crucial for understanding tooth form and function under physiological conditions. Results from such advanced dynamic approaches will be applicable to evaluate and avoid mechanical failure in prosthodontics/endodontic treatments, and to test material behavior for modern tooth restoration in dentistry. This approach will also allow us to improve our knowledge in chewing-related biomechanics for functional diagnosis and therapy, and it will help paleoanthropologists to illuminate dental adaptive processes and morphological modifications in human evolution.

Human recombinant glutamate oxaloacetate transaminase 1 (GOT1) supplemented with oxaloacetate induces a protective effect after cerebral ischemia.

PubMed

Pérez-Mato, M; Ramos-Cabrer, P; Sobrino, T; Blanco, M; Ruban, A; Mirelman, D; Menendez, P; Castillo, J; Campos, F

2014-01-09

Blood glutamate scavenging is a novel and attractive protecting strategy to reduce the excitotoxic effect of extracellular glutamate released during ischemic brain injury. Glutamate oxaloacetate transaminase 1 (GOT1) activation by means of oxaloacetate administration has been used to reduce the glutamate concentration in the blood. However, the protective effect of the administration of the recombinant GOT1 (rGOT1) enzyme has not been yet addressed in cerebral ischemia. The aim of this study was to analyze the protective effect of an effective dose of oxaloacetate and the human rGOT1 alone and in combination with a non-effective dose of oxaloacetate in an animal model of ischemic stroke. Sixty rats were subjected to a transient middle cerebral artery occlusion (MCAO). Infarct volumes were assessed by magnetic resonance imaging (MRI) before treatment administration, and 24 h and 7 days after MCAO. Brain glutamate levels were determined by in vivo MR spectroscopy (MRS) during artery occlusion (80 min) and reperfusion (180 min). GOT activity and serum glutamate concentration were analyzed during the occlusion and reperfusion period. Somatosensory test was performed at baseline and 7 days after MCAO. The three treatments tested induced a reduction in serum and brain glutamate levels, resulting in a reduction in infarct volume and sensorimotor deficit. Protective effect of rGOT1 supplemented with oxaloacetate at 7 days persists even when treatment was delayed until at least 2 h after onset of ischemia. In conclusion, our findings indicate that the combination of human rGOT1 with low doses of oxaloacetate seems to be a successful approach for stroke treatment.

Human recombinant glutamate oxaloacetate transaminase 1 (GOT1) supplemented with oxaloacetate induces a protective effect after cerebral ischemia

PubMed Central

Pérez-Mato, M; Ramos-Cabrer, P; Sobrino, T; Blanco, M; Ruban, A; Mirelman, D; Menendez, P; Castillo, J; Campos, F

2014-01-01

Blood glutamate scavenging is a novel and attractive protecting strategy to reduce the excitotoxic effect of extracellular glutamate released during ischemic brain injury. Glutamate oxaloacetate transaminase 1 (GOT1) activation by means of oxaloacetate administration has been used to reduce the glutamate concentration in the blood. However, the protective effect of the administration of the recombinant GOT1 (rGOT1) enzyme has not been yet addressed in cerebral ischemia. The aim of this study was to analyze the protective effect of an effective dose of oxaloacetate and the human rGOT1 alone and in combination with a non-effective dose of oxaloacetate in an animal model of ischemic stroke. Sixty rats were subjected to a transient middle cerebral artery occlusion (MCAO). Infarct volumes were assessed by magnetic resonance imaging (MRI) before treatment administration, and 24 h and 7 days after MCAO. Brain glutamate levels were determined by in vivo MR spectroscopy (MRS) during artery occlusion (80 min) and reperfusion (180 min). GOT activity and serum glutamate concentration were analyzed during the occlusion and reperfusion period. Somatosensory test was performed at baseline and 7 days after MCAO. The three treatments tested induced a reduction in serum and brain glutamate levels, resulting in a reduction in infarct volume and sensorimotor deficit. Protective effect of rGOT1 supplemented with oxaloacetate at 7 days persists even when treatment was delayed until at least 2 h after onset of ischemia. In conclusion, our findings indicate that the combination of human rGOT1 with low doses of oxaloacetate seems to be a successful approach for stroke treatment PMID:24407245

Protective Effect of Ad-VEGF-Bone Mesenchymal Stem Cells on Cerebral Infarction.

PubMed

Chen, Bo; Zhang, Feng; Li, Qiao-Yu; Gong, Aihua; Lan, Qing

2016-01-01

To understand the mechanism of intracerebroventricular transplantation of vascular endothelial growth factor (VEGF) genemodified bone mesenchymal stem cells (BMSCs) in rats after cerebral infarction. The middle cerebral artery occlusion ischemia/reperfusion (MCAO I/R) model was established in rats using the Zea-Longa suture method. A recombinant adenovirus (Ad-VEGF) was engineered to express VEGF. The rats were divided into 3 groups. Control BMSC infected with control adenovirus (BMSC-Ad), BMSC infected by Ad-VEGF (BMSC-Ad-VEGF), and phosphate buffered saline (PBS) suspension were injected into the intracerebroventricular system of the rats in groups 1, 2 and 3 respectively, 24 hours after middle cerebral artery occlusion (MCAO). The neurological function of rats was evaluated with the modified Neurological Severity Scores (mNSS). The infarct volume of brain in rats was determined using 2,3,5-triphenyltetrazolium chloride (TTC) stain at 14 days. GFAP and pGSK3β expression of ischemic penumbra was determined using immunohistochemical method. GFAP, pAKT, AKT, and pGSK3β expressions were determined with Western blot. Functional improvement was accelerated in animals receiving BMSC-Ad, while improvement at all times between 7 days and 28 days post MCAO was significantly greater in animals transplanted with BMSC-Ad-VEGF than for other treated animals. The number of GFAP-labeled cells was prevented by post-ischemic BMSC-Ad-VEGF treatment; pMCAO activate the PI3K/AKT/GSK3β pathway to reduce reactive gliosis. Our findings demonstrate that PI3K/AKT/GSK3β pathway could reduce reactive gliosis, ameliorate neurological deficit, diminish the percentage of cerebral infarction volume in rats, and facilitate angiogenesis.

Intermittent fasting attenuates increases in neurogenesis after ischemia and reperfusion and improves recovery.

PubMed

Manzanero, Silvia; Erion, Joanna R; Santro, Tomislav; Steyn, Frederik J; Chen, Chen; Arumugam, Thiruma V; Stranahan, Alexis M

2014-05-01

Intermittent fasting (IF) is neuroprotective across a range of insults, but the question of whether extending the interval between meals alters neurogenesis after ischemia remains unexplored. We therefore measured cell proliferation, cell death, and neurogenesis after transient middle cerebral artery occlusion (MCAO) or sham surgery (SHAM) in mice fed ad libitum (AL) or maintained on IF for 3 months. IF was associated with twofold reductions in circulating levels of the adipocyte cytokine leptin in intact mice, but also prevented further reductions in leptin after MCAO. IF/MCAO mice also exhibit infarct volumes that were less than half those of AL/MCAO mice. We observed a 30% increase in basal cell proliferation in the hippocampus and subventricular zone (SVZ) in IF/SHAM, relative to AL/SHAM mice. However, cell proliferation after MCAO was limited in IF mice, which showed twofold increases in cell proliferation relative to IF/SHAM, whereas AL/MCAO mice exhibit fivefold increases relative to AL/SHAM. Attenuation of stroke-induced neurogenesis was correlated with reductions in cell death, with AL/MCAO mice exhibiting twice the number of dying cells relative to IF/MCAO mice. These observations indicate that IF protects against neurological damage in ischemic stroke, with circulating leptin as one possible mediator.

Intermittent fasting attenuates increases in neurogenesis after ischemia and reperfusion and improves recovery

PubMed Central

Manzanero, Silvia; Erion, Joanna R; Santro, Tomislav; Steyn, Frederik J; Chen, Chen; Arumugam, Thiruma V; Stranahan, Alexis M

2014-01-01

Intermittent fasting (IF) is neuroprotective across a range of insults, but the question of whether extending the interval between meals alters neurogenesis after ischemia remains unexplored. We therefore measured cell proliferation, cell death, and neurogenesis after transient middle cerebral artery occlusion (MCAO) or sham surgery (SHAM) in mice fed ad libitum (AL) or maintained on IF for 3 months. IF was associated with twofold reductions in circulating levels of the adipocyte cytokine leptin in intact mice, but also prevented further reductions in leptin after MCAO. IF/MCAO mice also exhibit infarct volumes that were less than half those of AL/MCAO mice. We observed a 30% increase in basal cell proliferation in the hippocampus and subventricular zone (SVZ) in IF/SHAM, relative to AL/SHAM mice. However, cell proliferation after MCAO was limited in IF mice, which showed twofold increases in cell proliferation relative to IF/SHAM, whereas AL/MCAO mice exhibit fivefold increases relative to AL/SHAM. Attenuation of stroke-induced neurogenesis was correlated with reductions in cell death, with AL/MCAO mice exhibiting twice the number of dying cells relative to IF/MCAO mice. These observations indicate that IF protects against neurological damage in ischemic stroke, with circulating leptin as one possible mediator. PMID:24549184

Using OCT-based microangiography for in vivo longitudinal study of arteriogenesis (Conference Presentation)

NASA Astrophysics Data System (ADS)

Li, Yuandong; Choi, Woo June; Wang, Ruikang K.

2017-03-01

The adaptive growth of collateral vessels, termed "arteriogenesis", is crucial for maintaining regional blood supply during arterial obstruction and offsetting the adverse effect of tissue ischemia. Stimulation of arteriogenesis has been applied for the treatment of occlusive vascular diseases, and in vivo imaging of the progressive development of collateral vessel will facilitate a better understanding of the mechanism. We present using high-resolution OCT-based microangiography (OMAG) to image arteriogenesis process longitudinally in mouse cerebral cortex after middle cerebral artery occlusion (MCAO). We imaged the collateral arterioles at the arteriolo-arteriolar anastomosis (AAA) within 7-day period after MCAO to reveal key elements of collateral vessel remodeling, including alteration in vessel morphology, velocity and directionality of blood flow. The magnitudes of changes in these parameters matched the time course of the active building of collateral vessels stated in previous studies using histology. Hence, OMAG is a promising imaging tool for non-invasive longitudinal study of functional collateral vessel growth in small animal models and can be potentially applied in the experimental study of arteriogenesis stimulation.

Focal epidural cooling reduces the infarction volume of permanent middle cerebral artery occlusion in swine.

PubMed

Zhang, Lihua; Cheng, Huilin; Shi, Jixin; Chen, Jun

2007-02-01

The protective effect against ischemic stroke by systemic hypothermia is limited by the cooling rate and it has severe complications. This study was designed to evaluate the effect of SBH induced by epidural cooling on infarction volume in a swine model of PMCAO. Permanent middle cerebral artery occlusion was performed in 12 domestic swine assigned to groups A and B. In group A, the cranial and rectal temperatures were maintained at normal range (37 degrees C-39 degrees C) for 6 hours after PMCAO. In group B, cranial temperature was reduced to moderate (deep brain, <30 degrees C) and deep (brain surface, <20 degrees C) temperature and maintained at that level for 5 hours after 1 hour after PMCAO, by the epidural cooling method. All animals were euthanized 6 hours after MCAO; their brains were sectioned and stained with 2,3,5-triphenyltetrazolium chloride and their infarct volumes were calculated. The moderate and deep brain temperature (at deep brain and brain surface) can be induced by rapid epidural cooling, whereas the rectal temperature was maintained within normal range. The infarction volume after PMCAO was significantly reduced by epidural cooling compared with controls (13.73% +/- 1.82% vs 5.62% +/- 2.57%, P < .05). The present study has demonstrated, with histologic confirmation, that epidural cooling may be a useful strategy for reducing infarct volume after the onset of ischemia.

Inheritance of Occlusal Topography: A Twin Study

PubMed Central

Su, C-Y.; Corby, P.M.; Elliot, M.A.; Studen-Pavlovich, D.A.; Ranalli, D.N.; Rosa, B.; Wessel, J.; Schork, N.J.; Hart, T.C.; Bretz, W.A.

2011-01-01

Aim This was to determine the relative contribution of genetic factors on the morphology of occlusal surfaces of mandibular primary first molars by employing the twin study model. Methods The occlusal morphology of mandibular primary first molar teeth from dental casts of 9 monozygotic (MZ) twin pairs and 12 dizygotic (DZ) twin pairs 4 to 7 years old, were digitized by contact-type three-dimensional (3D) scanner. To compare the similarity of occlusal morphology between twin sets, each twin pair of occlusal surfaces was superimposed to establish the best fit by using computerized least squared techniques. Heritability was computed using a variance component model, adjusted for age and gender. Results DZ pairs demonstrated a greater degree of occlusal morphology variance. The total amount of difference in surface overlap was 0.0508 mm (0.0018 (inches) for the MZ (n=18) sample and 0.095 mm (0.0034 inches) for the DZ (n=24) sample and were not statistically significant (p=0.2203). The transformed mean differences were not statistically significantly different (p=0.2203). Heritability estimates of occlusal surface areas for right and left mandibular primary first molars were 97.5% and 98.2% (p<0.0001), respectively. Conclusions Occlusal morphology of DZ twin pairs was more variable than that of MZ twin pairs. Heritability estimates revealed that genetic factors strongly influence occlusal morphology of mandibular primary first molars. PMID:18328234

Neuroprotective effects of bisperoxovanadium on cerebral ischemia by inflammation inhibition.

PubMed

Mao, Lun-Lin; Hao, Dong-Lin; Mao, Xiao-Wei; Xu, Yuan-Feng; Huang, Ting-Ting; Wu, Bo-Na; Wang, Li-Hui

2015-08-18

PTEN is a dual specificity phosphatase and is implicated in inflammation and apoptosis of cerebral ischemia and reperfusion (I/R) injury. Bisperoxovanadium (Bpv), a specific inhibitor of PTEN's phosphatase activity, has demonstrated powerful neuroprotective properties. We investigated the neuroprotective roles of Bpv in the rat model of middle cerebral artery occlusion (MCAO) cerebral I/R injury, and explored the modulation of inflammatory mediators and PI3K/Akt/GSK-3β pathways by Bpv. Our results showed that treatment with Bpv (0.2 mg/kg/day) significantly decreased neurological deficit scores at 7 days after MCAO and infarct volume at 4 days after MCAO. The IL-10 concentration was increased and TNF-α concentration was decreased in the ischemic boundary zone of the cerebral cortex at 4 days after MCAO by Bpv. Furthermore, Bpv (0.2 mg/kg/day) treatment significantly reduced PTEN mRNA and protein levels and increased PI3K, Akt and p-GSK-3β proteins expression in the ischemic boundary zone of the cerebral cortex at 4 days after MCAO. In conclusions, Bpv treatment demonstrates neuroprotective effects on cerebral ischemia and reperfusion injury of ischemic stroke rats and is associated with its modulation of inflammatory mediator production and up-regulation of PTEN downstream proteins PI3K, Akt and p-GSK-3β. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A New Approach of Short Wave Protection against Middle Cerebral Artery Occlusion/Reperfusion Injury via Attenuation of Golgi Apparatus Stress by Inhibition of Downregulation of Secretory Pathway Ca(2+)-ATPase Isoform 1 in Rats.

PubMed

Fan, Yongmei; Zhang, Changjie; Li, Ting; Peng, Wenna; Yin, Jing; Li, Xiaofao; Kong, Ying; Lan, Chunna; Wang, Rumi; Hu, Zhiping

2016-07-01

Short wave (SW), a pattern of electromagnetic therapy, achieves an oscillating electromagnetic field. It has been reported that it may have a potential effect on cerebral injury. The present study was designed to investigate the potential role and possible mechanism of SW in focal cerebral ischemia/reperfusion (I/R) injury in rats. Secretory pathway Ca(2+)/Mn(2+) ATPase isoform 1 is a major component of Golgi apparatus stress. It has been reported as representative of Golgi apparatus stress. Up to 120 minutes of middle cerebral artery occlusion (MCAO) and reperfusion injury was induced in male Sprague-Dawley rats. Different sessions of SW daily were administered over head after reperfusion from day 1 to day 7. Functional recovery scores, survival rates, infarct volume analysis, electron microscope test, and western blotting studies were used to analyze the therapy. SW protected against neuronal death and apoptosis in cornu ammon 1 region of hippocampus by reducing neuronal deficit, infarct volume, and ultrastructure. SW partly inhibited upregulation of caspase3. In addition, the expression of secretory pathway Ca(2+)-ATPase isoform 1 (SPCA1) was upregulated by SW. Our data indicate that SW can be protected against focal cerebral I/R injury, and the influence on Golgi apparatus stress might provide us a new perspective in further study. To the authors' knowledge, this is the first report using SW to increase expression of SPCA1 indicating modulate Golgi apparatus stress in MCAO and reperfusion model. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Neuroprotective effects of chloroform and petroleum ether extracts of Nigella sativa seeds in stroke model of rat

PubMed Central

Akhtar, Mohammad; Maikiyo, Aliyu Muhammad; Najmi, Abul Kalam; Khanam, Razia; Mujeeb, Mohd; Aqil, Mohd

2013-01-01

PURPOSE: Stroke still remains a challenge for the researchers and scientists for developing ideal drug. Several new drugs are being evaluated showing excellent results in preclinical studies but when tested in clinical trials, they failed. Many herbal drugs in different indigenous system of medicine claim to have beneficial effects but not extensively evaluated for stroke (cerebral ischemia). AIM: The present study was undertaken to evaluate chloroform and petroleum ether extract of Nigella sativa seeds administered at a dose of 400 mg/kg, per orally for seven days in middle cerebral artery occluded (MCAO) rats for its neuroprotective role in cerebral ischemia. MATERIALS AND METHODS: Focal cerebral ischemia was induced by middle cerebral artery occlusion for two hours followed by reperfusion for 22 hours. After 24 hours, grip strength, locomotor activity tests were performed in different treatment groups of rats. After completing behavioral tests, animals were sacrificed; brains were removed for the measurement of infarct volume followed by the estimation of markers of oxidative stress. RESULTS: Both chloroform and petroleum ether extracts-pretreated rats showed improvement in locomotor activity and grip strength, reduced infarct volume when compared with MCAO rats. MCA occlusion resulted in the elevation of levels of thiobarbituric acid reactive substance (TBARS), while a reduction in the levels of glutathione (GSH) and antioxidant enzymes viz. superoxide dismutase (SOD) and catalase levels were observed. Pre-treatment of both extracts of Nigella sativa showed reduction in TBARS, elevation in glutathione, SOD, and catalase levels when compared with MCAO rats. CONCLUSION: The chloroform and petroleum ether extract of Nigella sativa showed the protective effects in cerebral ischemia. The present study confirms the antioxidant, free radical scavenging, and anti-inflammatory properties of Nigella sativa already reported. PMID:23833517

(-)-Phenserine inhibits neuronal apoptosis following ischemia/reperfusion injury.

PubMed

Chang, Cheng-Fu; Lai, Jing-Huei; Wu, John Chung-Che; Greig, Nigel H; Becker, Robert E; Luo, Yu; Chen, Yen-Hua; Kang, Shuo-Jhen; Chiang, Yung-Hsiao; Chen, Kai-Yun

2017-12-15

Stroke commonly leads to adult disability and death worldwide. Its major symptoms are spastic hemiplegia and discordant motion, consequent to neuronal cell death induced by brain vessel occlusion. Acetylcholinesterase (AChE) is upregulated and allied with inflammation and apoptosis after stroke. Recent studies suggest that AChE inhibition ameliorates ischemia-reperfusion injury and has neuroprotective properties. (-)-Phenserine, a reversible AChE inhibitor, has a broad range of actions independent of its AChE properties, including neuroprotective ones. However, its protective effects and detailed mechanism of action in the rat middle cerebral artery occlusion model (MCAO) remain to be elucidated. This study investigated the therapeutic effects of (-)-phenserine for stroke in the rat focal cerebral ischemia model and oxygen-glucose deprivation/reperfusion (OGD/RP) damage model in SH-SY5Y neuronal cultures. (-)-Phenserine mitigated OGD/PR-induced SH-SY5Y cell death, providing an inverted U-shaped dose-response relationship between concentration and survival. In MCAO challenged rats, (-)-phenserine reduced infarction volume, cell death and improved body asymmetry, a behavioral measure of stoke impact. In both cellular and animal studies, (-)-phenserine elevated brain-derived neurotrophic factor (BDNF) and B-cell lymphoma 2 (Bcl-2) levels, and decreased activated-caspase 3, amyloid precursor protein (APP) and glial fibrillary acidic protein (GFAP) expression, potentially mediated through the ERK-1/2 signaling pathway. These actions mitigated neuronal apoptosis in the stroke penumbra, and decreased matrix metallopeptidase-9 (MMP-9) expression. In synopsis, (-)-phenserine significantly reduced neuronal damage induced by ischemia/reperfusion injury in a rat model of MCAO and cellular model of OGD/RP, demonstrating that its anti-apoptotic/neuroprotective/neurotrophic cholinergic and non-cholinergic properties warrant further evaluation in conditions of brain injury

[18F]DPA-714 PET imaging shows immunomodulatory effect of intravenous administration of bone marrow stromal cells after transient focal ischemia.

PubMed

Tan, Chengbo; Zhao, Songji; Higashikawa, Kei; Wang, Zifeng; Kawabori, Masahito; Abumiya, Takeo; Nakayama, Naoki; Kazumata, Ken; Ukon, Naoyuki; Yasui, Hironobu; Tamaki, Nagara; Kuge, Yuji; Shichinohe, Hideo; Houkin, Kiyohiro

2018-05-02

The potential application of bone marrow stromal cell (BMSC) therapy in stroke has been anticipated due to its immunomodulatory effects. Recently, positron emission tomography (PET) with [ 18 F]DPA-714, a translocator protein (TSPO) ligand, has become available for use as a neural inflammatory indicator. We aimed to evaluate the effects of BMSC administration after transient middle cerebral artery occlusion (MCAO) using [ 18 F]DPA-714 PET. The BMSCs or vehicle were administered intravenously to rat MCAO models at 3 h after the insult. Neurological deficits, body weight, infarct volume, and histology were analyzed. [ 18 F]DPA-714 PET was performed 3 and 10 days after MCAO. Rats had severe neurological deficits and body weight loss after MCAO. Cell administration ameliorated these effects as well as the infarct volume. Although weight loss occurred in the spleen and thymus, cell administration suppressed it. In both vehicle and BMSC groups, [ 18 F]DPA-714 PET showed a high standardized uptake value (SUV) around the ischemic area 3 days after MCAO. Although SUV was increased further 10 days after MCAO in both groups, the increase was inhibited in the BMSC group, significantly. Histological analysis showed that an inflammatory reaction occurred in the lymphoid organs and brain after MCAO, which was suppressed in the BMSC group. The present results suggest that BMSC therapy could be effective in ischemic stroke due to modulation of systemic inflammatory responses. The [ 18 F]DPA-714 PET/CT system can accurately demonstrate brain inflammation and evaluate the BMSC therapeutic effect in an imaging context. It has great potential for clinical application.

Ferulic Acid Attenuates the Injury-Induced Decrease of Protein Phosphatase 2A Subunit B in Ischemic Brain Injury

PubMed Central

Koh, Phil-Ok

2013-01-01

Background Ferulic acid provides a neuroprotective effect during cerebral ischemia through its anti-oxidant function. Protein phosphatase 2A (PP2A) is a serine and threonine phosphatase that contributes broadly to normal brain function. This study investigated whether ferulic acid regulates PP2A subunit B in a middle cerebral artery occlusion (MCAO) animal model and glutamate toxicity-induced neuronal cell death. Methodology/Principal Findings MCAO was surgically induced to yield permanent cerebral ischemic injury in rats. The rats were treated with either vehicle or ferulic acid (100 mg/kg, i.v.) immediately after MCAO, and cerebral cortex tissues were collected 24 h after MCAO. A proteomics approach, RT-PCR, and Western blot analyses performed to identification of PP2A subunit B expression levels. Ferulic acid significantly reduced the MCAO-induced infarct volume of the cerebral cortex. A proteomics approach elucidated the reduction of PP2A subunit B in MCAO-induced animals, and ferulic acid treatment prevented the injury-induced reduction in PP2A subunit B levels. RT-PCR and Western blot analyses also showed that ferulic acid treatment attenuates the injury-induced decrease in PP2A subunit B levels. Moreover, the number of PP2A subunit B-positive cells was reduced in MCAO-induced animals, and ferulic acid prevented these decreases. In cultured neuronal cells, ferulic acid treatment protected cells against glutamate toxicity and prevented the glutamate-induced decrease in PP2A subunit B. Conclusions/Significance These results suggest that the maintenance of PP2A subunit B by ferulic acid in ischemic brain injury plays an important role for the neuroprotective function of ferulic acid. PMID:23349830

Breviscapine confers a neuroprotective efficacy against transient focal cerebral ischemia by attenuating neuronal and astrocytic autophagy in the penumbra.

PubMed

Pengyue, Zhang; Tao, Guo; Hongyun, He; Liqiang, Yang; Yihao, Deng

2017-06-01

Breviscapine is a flavonoid derived from a traditional Chinese herb Erigerin breviscapus (Vant.) Hand-Mazz, and has been extensively used in clinical treatment for cerebral stroke in China, but the underlying pharmacological mechanisms are still unclear. In present study, we investigated whether breviscapine could confer a neuroprotection against cerebral ischemia injury by targeting autophagy mechanisms. A cerebral stroke model in Sprague-Dawley rats was prepared by middle cerebral artery occlusion (MCAO), rats were then randomly divided into 5 groups: MCAO+Bre group, rats were treated with breviscapine; MCAO+Tat-Beclin-1 group, animals were administrated with specific autophagy inducer Tat-Beclin-1; MCAO+Bre+Tat-Beclin-1 group, rats were treated with both breviscapine and Tat-Beclin-1, MCAO+saline group, rats received the same volume of physiological saline, and Sham surgery group. The autophagy levels in infarct penumbra were evaluated by western blotting, real-time PCR and immunofluorescence 7days after the insult. Meanwhile, infarct volume, brain water content and neurological deficit score were assessed. The results illustrated that the infarct volume, brain water content and neurofunctional deficiency were significantly reduced by 7days of breviscapine treatment in MCAO+Bre group, compared with those in MCAO+saline group. Meanwhile, the western blotting, quantitative PCR and immunofluorescence showed that the autophagy in both neurons and astrocytes at the penumbra were markedly attenuated by breviscapine admininstration. Moreover, these pharmacological effects of breviscapine could be counteracted by autophagy inducer Tat-Beclin-1. Our study suggests that breviscapine can provide a neuroprotection against transient focal cerebral ischemia, and this biological function is associated with attenuating autophagy in both neurons and astrocytes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Immunomodulatory effect of Hawthorn extract in an experimental stroke model.

PubMed

Elango, Chinnasamy; Devaraj, Sivasithambaram Niranjali

2010-12-30

Recently, we reported a neuroprotective effect for Hawthorn (Crataegus oxyacantha) ethanolic extract in middle cerebral artery occlusion-(MCAO) induced stroke in rats. The present study sheds more light on the extract's mechanism of neuroprotection, especially its immunomodulatory effect. After 15 days of treatment with Hawthorn extract [100 mg/kg, pretreatment (oral)], male Sprague Dawley rats underwent transient MCAO for 75 mins followed by reperfusion (either 3 or 24 hrs). We measured pro-inflammatory cytokines (IL-1β, TNF-α, IL-6), ICAM-1, IL-10 and pSTAT-3 expression in the brain by appropriate methods. We also looked at the cytotoxic T cell sub-population among leukocytes (FACS) and inflammatory cell activation and recruitment in brain (using a myeloperoxidase activity assay) after ischemia and reperfusion (I/R). Apoptosis (TUNEL), and Bcl-xL- and Foxp3- (T(reg) marker) positive cells in the ipsilateral hemisphere of the brain were analyzed separately using immunofluorescence. Our results indicate that occlusion followed by 3 hrs of reperfusion increased pro-inflammatory cytokine and ICAM-1 gene expressions in the ipsilateral hemisphere, and that Hawthorn pre-treatment significantly (p ≤ 0.01) lowered these levels. Furthermore, such pre-treatment was able to increase IL-10 levels and Foxp3-positive cells in brain after 24 hrs of reperfusion. The increase in cytotoxic T cell population in vehicle rats after 24 hrs of reperfusion was decreased by at least 40% with Hawthorn pretreatment. In addition, there was a decrease in inflammatory cell activation and infiltration in pretreated brain. Hawthorn pretreatment elevated pSTAT-3 levels in brain after I/R. We also observed an increase in Bcl-xL-positive cells, which in turn may have influenced the reduction in TUNEL-positive cells compared to vehicle-treated brain. In summary, Hawthorn extract helped alleviate pro-inflammatory immune responses associated with I/R-induced injury, boosted IL-10 levels, and

Immunomodulatory effect of Hawthorn extract in an experimental stroke model

PubMed Central

2010-01-01

Background Recently, we reported a neuroprotective effect for Hawthorn (Crataegus oxyacantha) ethanolic extract in middle cerebral artery occlusion-(MCAO) induced stroke in rats. The present study sheds more light on the extract's mechanism of neuroprotection, especially its immunomodulatory effect. Methods After 15 days of treatment with Hawthorn extract [100 mg/kg, pretreatment (oral)], male Sprague Dawley rats underwent transient MCAO for 75 mins followed by reperfusion (either 3 or 24 hrs). We measured pro-inflammatory cytokines (IL-1β, TNF-α, IL-6), ICAM-1, IL-10 and pSTAT-3 expression in the brain by appropriate methods. We also looked at the cytotoxic T cell sub-population among leukocytes (FACS) and inflammatory cell activation and recruitment in brain (using a myeloperoxidase activity assay) after ischemia and reperfusion (I/R). Apoptosis (TUNEL), and Bcl-xL- and Foxp3- (Treg marker) positive cells in the ipsilateral hemisphere of the brain were analyzed separately using immunofluorescence. Results Our results indicate that occlusion followed by 3 hrs of reperfusion increased pro-inflammatory cytokine and ICAM-1 gene expressions in the ipsilateral hemisphere, and that Hawthorn pre-treatment significantly (p ≤ 0.01) lowered these levels. Furthermore, such pre-treatment was able to increase IL-10 levels and Foxp3-positive cells in brain after 24 hrs of reperfusion. The increase in cytotoxic T cell population in vehicle rats after 24 hrs of reperfusion was decreased by at least 40% with Hawthorn pretreatment. In addition, there was a decrease in inflammatory cell activation and infiltration in pretreated brain. Hawthorn pretreatment elevated pSTAT-3 levels in brain after I/R. We also observed an increase in Bcl-xL-positive cells, which in turn may have influenced the reduction in TUNEL-positive cells compared to vehicle-treated brain. Conclusions In summary, Hawthorn extract helped alleviate pro-inflammatory immune responses associated with I

Electroacupuncture improves cerebral blood flow and attenuates moderate ischemic injury via Angiotensin II its receptors-mediated mechanism in rats.

PubMed

Li, Jing; He, Jiaojun; Du, Yuanhao; Cui, Jingjun; Ma, Ying; Zhang, Xuezhu

2014-11-11

To investigate the effects and potential mechanism of electroacupuncture intervention on expressions of Angiotensin II and its receptors-mediated signaling pathway in experimentally induced cerebral ischemia. Totally 126 male Wistar rats were randomly divided into control group, model group and EA group. The latter two were further divided into ten subgroups (n = 6) following Middle Cerebral Artery Occlusion (MCAO). Changes in regional cerebral blood flow (rCBF) and expressions of Angiotensin II and its receptors (AT1R, AT2R), as well as effector proteins in phosphatidyl inositol signal pathway were monitored before and at different times after MCAO. MCAO-induced decline of ipsilateral rCBF was partially suppressed by electroacupuncture, and contralateral blood flow was also superior to that of model group. Angiotensin II level was remarkably elevated immediately after MCAO, while electroacupuncture group exhibited significantly lower levels at 1 to 3 h and the value was significantly increased thereafter. The enhanced expression of AT1R was partially inhibited by electroacupuncture, while increased AT2R level was further induced. Electroacupuncture stimulation attenuated and postponed the upregulated-expressions of Gq and CaM these upregulations. ELISA results showed sharply increased expressions of DAG and IP3, which were remarkably neutralized by electroacupuncture. MCAO induced significant increases in expression of Angiotensin II and its receptor-mediated signal pathway. These enhanced expressions were significantly attenuated by electroacupuncture intervention, followed by reduced vasoconstriction and improved blood supply in ischemic region, and ultimately conferred beneficial effects on cerebral ischemia.

Reduced microvascular volume and hemispherically deficient vasoreactivity to hypercapnia in acute ischemia: MRI study using permanent middle cerebral artery occlusion rat model

PubMed Central

Suh, J Y; Shim, Woo H; Cho, Gyunggoo; Fan, Xiang; Kwon, Seon J; Kim, Jeong K; Dai, George; Wang, Xiaoying; Kim, Young R

2015-01-01

Vasoreactivity to hypercapnia has been used for assessing cerebrovascular tone and control altered by ischemic stroke. Despite the high prognostic potential, traits of hypercapnia-induced hemodynamic changes have not been fully characterized in relation with baseline vascular states and brain tissue damage. To monitor cerebrovascular responses, T2- and T2*-weighted magnetic resonance imaging (MRI) images were acquired alternatively using spin- and gradient-echo echo plannar imaging (GESE EPI) sequence with 5% CO2 gas inhalation in normal (n=5) and acute stroke rats (n=10). Dynamic relative changes in cerebrovascular volume (CBV), microvascular volume (MVV), and vascular size index (VSI) were assessed from regions of interest (ROIs) delineated by the percent decrease of apparent diffusion coefficient (ADC). The baseline CBV was not affected by middle cerebral artery occlusion (MCAO) whereas the baseline MVV in ischemic areas was significantly lower than that in the rest of the brain and correlated with ADC. Vasoreactivity to hypercapnic challenge was considerably attenuated in the entire ipsilesional hemisphere including normal ADC regions, in which unsolicited, spreading depression-associated increases of CBV and MVV were observed. The lesion-dependent inhomogeneity in baseline MVV indicates the effective perfusion reserve for accurately delineating the true ischemic damage while the cascade of neuronal depolarization is probably responsible for the hemispherically lateralized changes in overall neurovascular physiology. PMID:25690471

Reduced microvascular volume and hemispherically deficient vasoreactivity to hypercapnia in acute ischemia: MRI study using permanent middle cerebral artery occlusion rat model.

PubMed

Suh, J Y; Shim, Woo H; Cho, Gyunggoo; Fan, Xiang; Kwon, Seon J; Kim, Jeong K; Dai, George; Wang, Xiaoying; Kim, Young R

2015-06-01

Vasoreactivity to hypercapnia has been used for assessing cerebrovascular tone and control altered by ischemic stroke. Despite the high prognostic potential, traits of hypercapnia-induced hemodynamic changes have not been fully characterized in relation with baseline vascular states and brain tissue damage. To monitor cerebrovascular responses, T2- and T2*-weighted magnetic resonance imaging (MRI) images were acquired alternatively using spin- and gradient-echo echo plannar imaging (GESE EPI) sequence with 5% CO2 gas inhalation in normal (n=5) and acute stroke rats (n=10). Dynamic relative changes in cerebrovascular volume (CBV), microvascular volume (MVV), and vascular size index (VSI) were assessed from regions of interest (ROIs) delineated by the percent decrease of apparent diffusion coefficient (ADC). The baseline CBV was not affected by middle cerebral artery occlusion (MCAO) whereas the baseline MVV in ischemic areas was significantly lower than that in the rest of the brain and correlated with ADC. Vasoreactivity to hypercapnic challenge was considerably attenuated in the entire ipsilesional hemisphere including normal ADC regions, in which unsolicited, spreading depression-associated increases of CBV and MVV were observed. The lesion-dependent inhomogeneity in baseline MVV indicates the effective perfusion reserve for accurately delineating the true ischemic damage while the cascade of neuronal depolarization is probably responsible for the hemispherically lateralized changes in overall neurovascular physiology.

The active metabolite of prasugrel, R-138727, improves cerebral blood flow and reduces cerebral infarction and neurologic deficits in a non-human primate model of acute ischaemic stroke.

PubMed

Sugidachi, Atsuhiro; Mizuno, Makoto; Ohno, Kousaku; Jakubowski, Joseph A; Tomizawa, Atsuyuki

2016-10-05

Previously, we showed preventive effects of prasugrel, a P2Y12 antagonist, in a non-human primate model of thrombotic middle cerebral artery occlusion (MCAO); however, it remains unclear if P2Y12 inhibition after MCAO reduces cerebral injury and dysfunction. Here we investigated the effects of R-138727, the major active metabolite of prasugrel, on ex vivo platelet aggregation at 5min, 15min, 60min, and 24h after administration to non-human primates (n=3). A single intravenous dose of R-138727 (0.03-0.3mg/kg) resulted in significant and sustained dose-related effects on platelets for up to 24h. R-138727 was administered 1h after MCAO induction, and its effects on thrombosis, cerebral infarction, and neurological deficits were determined (n=8-10). R-138727 (0.3mg/kg) significantly increased total patency rate of the MCA (P=0.0211). Although there was no effect on the patency rate before R-138727 dosing (P=0.3975), it increased 1h after dosing (P=0.0114). R-138727 significantly reduced total ischaemic infarction volumes (P=0.0147), including those of basal ganglia (P=0.0028), white matter (P=0.0393), and haemorrhagic infarction (P=0.0235). Additionally, treatment with R-138727 reduced overall neurological deficits (P=0.0019), including the subcategories of consciousness (P=0.0042), sensory system (P=0.0045), motor system (P=0.0079) and musculoskeletal coordination (P=0.0082). These findings support the possible utility of P2Y12 inhibition during early-onset MCAO to limit the progression and degree of cerebral ischaemia and infarction and also associated neurological deficits. Copyright © 2016 Elsevier B.V. All rights reserved.

Computer modeling of occlusal surfaces of posterior teeth with the CICERO CAD/CAM system.

PubMed

Olthoff, L W; Van Der Zel, J M; De Ruiter, W J; Vlaar, S T; Bosman, F

2000-08-01

Static and dynamic occlusal interference frequently needs to be corrected by selective grinding of the occlusal surface of conventional cast and ceramic-fused-to-metal restorations. CAD/CAM techniques allow control of the dimensional contours of these restorations. However, parameters responsible for the occlusal form need to be determined. In most articulators, these parameters are set as default values. Which technique is best for minimizing the introduction of occlusal interference in restorations has not been determined. This study investigated differences in crown structure of a crown designed in static occlusion (STA) with designs adapted for dynamic occlusal interferences. Therefore, values from an optoelectronic registration system (String-Condylocomp, KAVO), an occlusal generated path (OGP) technique and default settings (DEF) were used in the CICERO CAD/CAM system. Morphology of CON, DEF, and OGP crowns was compared with that of the STA crown with respect to differences in a buccolingual section and frequency of occlusal distances in an interocclusal range of 1 mm, measured from the occlusal surface of the crown. All crown types fulfilled the esthetic and morphologic criteria for restorations in clinical dentistry. Difference in the morphology of the OGP crown, compared with that of the STA crown, was greater than that for the CON and DEF crowns. These differences were seen especially in the distobuccal part of the occlusal surface; however, the number of occlusal contacts was considered sufficient to stabilize occlusion. Functional occlusion, adapted to dynamic occlusion in a CICERO crown for the first mandibular molar, can be obtained using data acquired with the String-Condylocomp registration system. The OGP technique was preferred to other techniques because of the simplicity of the technique for eliminating potential problems with opposing teeth during motion. However, this is achieved at the cost of fewer points of contact during occlusion than

Detection of questionable occlusal carious lesions using an electrical bioimpedance method with fractional electrical model

NASA Astrophysics Data System (ADS)

Morais, A. P.; Pino, A. V.; Souza, M. N.

2016-08-01

This in vitro study evaluated the diagnostic performance of an alternative electric bioimpedance spectroscopy technique (BIS-STEP) detect questionable occlusal carious lesions. Six specialists carried out the visual (V), radiography (R), and combined (VR) exams of 57 sound or non-cavitated occlusal carious lesion teeth classifying the occlusal surfaces in sound surface (H), enamel caries (EC), and dentinal caries (DC). Measurements were based on the current response to a step voltage excitation (BIS-STEP). A fractional electrical model was used to predict the current response in the time domain and to estimate the model parameters: Rs and Rp (resistive parameters), and C and α (fractional parameters). Histological analysis showed caries prevalence of 33.3% being 15.8% hidden caries. Combined examination obtained the best traditional diagnostic results with specificity = 59.0%, sensitivity = 70.9%, and accuracy = 60.8%. There were statistically significant differences in bioimpedance parameters between the H and EC groups (p = 0.016) and between the H and DC groups (Rs, p = 0.006; Rp, p = 0.022, and α, p = 0.041). Using a suitable threshold for the Rs, we obtained specificity = 60.7%, sensitivity = 77.9%, accuracy = 73.2%, and 100% of detection for deep lesions. It can be concluded that BIS-STEP method could be an important tool to improve the detection and management of occlusal non-cavitated primary caries and pigmented sites.

Ferulic acid attenuates the cerebral ischemic injury-induced decrease in peroxiredoxin-2 and thioredoxin expression.

PubMed

Sung, Jin-Hee; Gim, Sang-Ah; Koh, Phil-Ok

2014-04-30

Ferulic acid, a phenolic phytochemical compound found in various plants, has a neuroprotective effect through its anti-oxidant and anti-inflammation functions. Peroxiredoxin-2 and thioredoxin play a potent neuroprotective function against oxidative stress. We investigated whether ferulic acid regulates peroxiredoxin-2 and thioredoxin levels in cerebral ischemia. Sprague-Dawley rats (male, 210-230g) were treated with vehicle or ferulic acid (100mg/kg) after middle cerebral artery occlusion (MCAO), and cerebral cortex tissues were collected 24h after MCAO. Decreases in peroxiredoxin-2 and thioredoxin levels were elucidated in MCAO-operated animals using a proteomics approach. We found that ferulic acid treatment prevented the MCAO-induced decrease in the expression of peroxiredoxin-2 and thioredoxin. RT-PCR and Western blot analyses confirmed that ferulic acid treatment attenuated the MCAO-induced decrease in peroxiredoxin-2 and thioredoxin levels. Moreover, immunoprecipitation analysis showed that the interaction between thioredoxin and apoptosis signal-regulating kinase 1 (ASK1) decreased during MCAO, whereas ferulic acid prevented the MCAO-induced decrease in this interaction. Our findings suggest that ferulic acid plays a neuroprotective role by attenuating injury-induced decreases in peroxiredoxin-2 and thioredoxin levels in neuronal cell injury. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Neuroprotection by glutamate oxaloacetate transaminase in ischemic stroke: an experimental study.

PubMed

Campos, Francisco; Sobrino, Tomás; Ramos-Cabrer, Pedro; Argibay, Bárbara; Agulla, Jesús; Pérez-Mato, María; Rodríguez-González, Raquel; Brea, David; Castillo, José

2011-06-01

As ischemic stroke is associated with an excessive release of glutamate into the neuronal extracellular space, a decrease in blood glutamate levels could provide a mechanism to remove it from the brain tissue, by increasing the brain-blood gradient. In this regard, the ability of glutamate oxaloacetate transaminase (GOT) to metabolize glutamate in blood could represent a potential neuroprotective tool for ischemic stroke. This study aimed to determine the neuroprotective effects of GOT in an animal model of cerebral ischemia by means of a middle cerebral arterial occlusion (MCAO) following the Stroke Therapy Academic Industry Roundtable (STAIR) group guidelines. In this animal model, oxaloacetate-mediated GOT activation inhibited the increase of blood and cerebral glutamate after MCAO. This effect is reflected in a reduction of infarct size, smaller edema volume, and lower sensorimotor deficits with respect to controls. Magnetic resonance spectroscopy confirmed that the increase of glutamate levels in the brain parenchyma after MCAO is inhibited after oxaloacetate-mediated GOT activation. These findings show the capacity of the GOT to remove glutamate from the brain by means of blood glutamate degradation, and suggest the applicability of this enzyme as an efficient and novel neuroprotective tool against ischemic stroke.

Blood-Spinal Cord Barrier Alterations in Subacute and Chronic Stages of a Rat Model of Focal Cerebral Ischemia

PubMed Central

Haller, Edward; Tajiri, Naoki; Thomson, Avery; Barretta, Jennifer; Williams, Stephanie N.; Haim, Eithan D.; Qin, Hua; Frisina-Deyo, Aric; Abraham, Jerry V.; Sanberg, Paul R.; Van Loveren, Harry; Borlongan, Cesario V.

2016-01-01

We previously demonstrated blood-brain barrier impairment in remote contralateral brain areas in rats at 7 and 30 days after transient middle cerebral artery occlusion (tMCAO), indicating ischemic diaschisis. Here, we focused on effects of subacute and chronic focal cerebral ischemia on the blood-spinal cord barrier (BSCB). We observed BSCB damage on both sides of the cervical spinal cord in rats at 7 and 30 days post-tMCAO. Major BSCB ultrastructural changes in spinal cord gray and white matter included vacuolated endothelial cells containing autophagosomes, pericyte degeneration with enlarged mitochondria, astrocyte end-feet degeneration and perivascular edema; damaged motor neurons, swollen axons with unraveled myelin in ascending and descending tracts and astrogliosis were also observed. Evans Blue dye extravasation was maximal at 7 days. There was immunofluorescence evidence of reduction of microvascular expression of tight junction occludin, upregulation of Beclin-1 and LC3B immunoreactivities at 7 days and a reduction of the latter at 30 days post-ischemia. These novel pathological alterations on the cervical spinal cord microvasculature in rats after tMCAO suggest pervasive and long-lasting BSCB damage after focal cerebral ischemia, and that spinal cord ischemic diaschisis should be considered in the pathophysiology and therapeutic approaches in patients with ischemic cerebral infarction. PMID:27283328

The Effect of Infrarenal Aortic Balloon Occlusion on Weaning from Supraceliac Aortic Balloon Occlusion in a Porcine Model (Sus scrofa) of Hemorrhagic Shock

DTIC Science & Technology

2017-06-15

all animals , and continued for six hours. Half of the animals were randomly assigned to Zone-3 REBOA for an additional 45 minutes following Zone-1...concentration or resuscitation requirements.Conclusion: In an animal model of hemorrhagic shock and Zone-1 REBOA, subsequent Zone-3 aortic occlusion did not add

Progesterone induces neuroprotection following reperfusion-promoted mitochondrial dysfunction after focal cerebral ischemia in rats.

PubMed

Andrabi, Syed Suhail; Parvez, Suhel; Tabassum, Heena

2017-06-01

Organelle damage and increases in mitochondrial permeabilization are key events in the development of cerebral ischemic tissue injury because they cause both modifications in ATP turnover and cellular apoptosis/necrosis. Early restoration of blood flow and improvement of mitochondrial function might reverse the situation and help in recovery following an onset of stroke. Mitochondria and related bioenergetic processes can be effectively used as pharmacological targets. Progesterone (P4), one of the promising neurosteroids, has been found to be neuroprotective in various models of neurological diseases, through a number of mechanisms. This influenced us to investigate the possible role of P4 in the mitochondria-mediated neuroprotective mechanism in an ischemic stroke model of rat. In this study, we have shown the positive effect of P4 administration on behavioral deficits and mitochondrial health in an ischemic stroke injury model of transient middle cerebral artery occlusion (tMCAO). After induction of tMCAO, the rats received an initial intraperitoneal injection of P4 (8 mg/kg body weight) or vehicle at 1 h post-occlusion followed by subcutaneous injections at 6, 12 and 18 h. Behavioral assessment for functional deficits included grip strength, motor coordination and gait analysis. Findings revealed a significant improvement with P4 treatment in tMCAO animals. Staining of isolated brain slices from P4-treated rats with 2,3,5-triphenyltetrazolium chloride (TTC) showed a reduction in the infarct area in comparison to the vehicle group, indicating the presence of an increased number of viable mitochondria. P4 treatment was also able to attenuate mitochondrial reactive oxygen species (ROS) production, as well as block the mitochondrial permeability transition pore (mPTP), in the tMCAO injury model. In addition, it was also able to ameliorate the altered mitochondrial membrane potential and respiration ratio in the ischemic animals, thereby suggesting that P4 has

Neuroprotection by baicalein in ischemic brain injury involves PTEN/AKT pathway.

PubMed

Liu, Chao; Wu, Jiliang; Xu, Kui; Cai, Fei; Gu, Jun; Ma, Liqun; Chen, Jianguo

2010-03-01

Recently more evidences support baicalein (Bai) is neuroprotective in models of ischemic stroke. This study was conducted to determine the molecular mechanisms involved in this effect. Either permanent or transient (2 h) middle cerebral artery occlusion (MCAO) was induced in rats in this study. Permanent MCAO led to larger infarct volumes in contrast to transient MCAO. Only in transient MCAO, Bai administration significantly reduced infarct size. Baicalein also markedly reduced apoptosis in the penumbra of transient MCAO rats. Additionally, oxygen and glucose deprivation (OGD) was used to mimic ischemic insult in primary cultured cortical neurons. A rapid increase in the intracellular reactive oxygen species level and nitrotyrosine formation induced by OGD was counteracted by Bai, which is parallel with attenuated cell injury. The reduction of phosphorylation Akt and glycogen synthase kinase-3beta (GSK3beta) induced by OGD was restored by Bai, which was associated with preserved levels of phosphorylation of PTEN, the phophatase that negatively regulates Akt. As a consequence, Bcl-2/Bcl-xL-associated death protein phosphorylation was increased and the protein level of Bcl-2 in motochondria was maintained, which subsequently antagonize cytochrome c released in cytosol. LY294002 blocked the increase in phospho-AKT evoked by Bai and abolished the associated protective effect. Together, these findings provide evidence that Bai protects neurons against ischemia injury and this neuroprotective effect involves PI3K/Akt and PTEN pathway.

Involvement of brain-gut axis in treatment of cerebral infarction by β-asaron and paeonol.

PubMed

He, Xiaogang; Cai, Qiufang; Li, Jianxiang; Guo, Weifeng

2018-02-14

Cerebral infarction (CI) causes severe brain damage with high incidence. This study aimed to investigate the involvement of brain-gut axis in the treatment of CI by combined administration of β-asaron and paeonol. Rat middle cerebral artery occlusion (MCAO) model was established, the interleukin-1beta (IL-1β) and tumor necrosis factor α (TNF-α) in the rat peripheral blood were determined by ELISA assay, and brain tissue damage was evaluated by TUNNEL assay. The correlation of cholecystokinin (CCK) and nuclear factor-kappaB (NF-κB) signaling components between intestinal mucosa and prefrontal cortex of MCAO rats treated with β-asaron and paeonol were analyzed by quantitative RT-PCR and western blotting. In vitro transwell co-culture was performed to confirm the correlated expression. The expression of CCK and NF-κB signaling components were closely correlated between the intestinal mucosa and prefrontal cortex of MCAO rats treated with β-asaron and paeonol. The combined administration also regulates the IL-1β and TNF-α in the MCAO rat peripheral blood and ameliorate the brain damage in MCAO rats. Elevated expression of related genes was observed in the cortical neurons co-cultured with intestinal mucosal epithelial cells treated by β-asaron and paeonol. The brain-gut axis mediates the therapeutic effect of β-asaron and paeonol for cerebral infarction through CCK and NF-κB signaling. Copyright © 2017 Elsevier B.V. All rights reserved.

Detection of questionable occlusal carious lesions using an electrical bioimpedance method with fractional electrical model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morais, A. P.; Salgado de Oliveira University, Marechal Deodoro Street, 217 – Centro, Niterói, Rio de Janeiro; Pino, A. V.

This in vitro study evaluated the diagnostic performance of an alternative electric bioimpedance spectroscopy technique (BIS-STEP) detect questionable occlusal carious lesions. Six specialists carried out the visual (V), radiography (R), and combined (VR) exams of 57 sound or non-cavitated occlusal carious lesion teeth classifying the occlusal surfaces in sound surface (H), enamel caries (EC), and dentinal caries (DC). Measurements were based on the current response to a step voltage excitation (BIS-STEP). A fractional electrical model was used to predict the current response in the time domain and to estimate the model parameters: Rs and Rp (resistive parameters), and C andmore » α (fractional parameters). Histological analysis showed caries prevalence of 33.3% being 15.8% hidden caries. Combined examination obtained the best traditional diagnostic results with specificity = 59.0%, sensitivity = 70.9%, and accuracy = 60.8%. There were statistically significant differences in bioimpedance parameters between the H and EC groups (p = 0.016) and between the H and DC groups (Rs, p = 0.006; Rp, p = 0.022, and α, p = 0.041). Using a suitable threshold for the Rs, we obtained specificity = 60.7%, sensitivity = 77.9%, accuracy = 73.2%, and 100% of detection for deep lesions. It can be concluded that BIS-STEP method could be an important tool to improve the detection and management of occlusal non-cavitated primary caries and pigmented sites.« less

Optical-resolution photoacoustic microscopy of ischemic stroke

NASA Astrophysics Data System (ADS)

Hu, Song; Gonzales, Ernie; Soetikno, Brian; Gong, Enhao; Yan, Ping; Maslov, Konstantin; Lee, Jin-Moo; Wang, Lihong V.

2011-03-01

A major obstacle in understanding the mechanism of ischemic stroke is the lack of a tool to noninvasively or minimally invasively monitor cerebral hemodynamics longitudinally. Here, we applied optical-resolution photoacoustic microscopy (OR-PAM) to longitudinally study ischemic stroke induced brain injury in a mouse model with transient middle cerebral artery occlusion (MCAO). OR-PAM showed that, during MCAO, the average hemoglobin oxygen saturation (sO2) values of feeder arteries and draining veins within the stroke core region dropped ~10% and ~34%, respectively. After reperfusion, arterial sO2 recovered back to the baseline; however, the venous sO2 increased above the baseline value by ~7%. Thereafter, venous sO2 values were close to the arterial sO2 values, suggesting eventual brain tissue infarction.

Protective Effect of Ischemic Preconditioning on Myocardium Against Remote Tissue Injury Following Transient Focal Cerebral Ischemia in Diabetic Rats

PubMed Central

Kumas, Meltem; Altintas, Ozge; Karatas, Ersin; Kocyigit, Abdurrahim

2017-01-01

Background Remote ischemic preconditioning (IPreC) could provide tissue-protective effect at a remote site by anti-inflammatory, neuronal, and humoral signaling pathways. Objectives The aim of the study was to investigate the possible protective effects of remote IPreC on myocardium after transient middle cerebral artery occlusion (MCAo) in streptozotocin- induced diabetic (STZ) and non-diabetic rats. Methods 48 male Spraque Dawley rats were divided into eight groups: Sham, STZ, IPreC, MCAo, IPreC+MCAo, STZ+IPreC, STZ+MCAo and STZ+IPreC+MCAo groups. We induced transient MCAo seven days after STZ-induced diabetes, and performed IPreC 72 hours before transient MCAo. Remote myocardial injury was investigated histopathologically. Bax, Bcl2 and caspase-3 protein levels were measured by Western blot analysis. Total antioxidant status (TAS), total oxidant status (TOS) of myocardial tissue were measured by colorimetric assay. Oxidative stress index(OSI) was calculated as TOS-to-TAS ratio. For all statistical analysis, p values < 0.05 were considered significant. Results We observed serious damage including necrosis, congestion and mononuclear cell infiltration in myocardial tissue of the diabetic and ischemic groups. In these groups TOS and OSI levels were significantly higher; TAS levels were lower than those of IPreC related groups (p < 0.05). IPreC had markedly improved histopathological alterations and increased TAS levels in IPreC+MCAo and STZ+IPreC+MCAo compared to MCAo and STZ+MCAo groups (p < 0.05). In non-diabetic rats, MCAo activated apoptotic cell death via increasing Bax/Bcl2 ratio and caspase-3 levels. IPreC reduced apoptotic cell death by suppressing pro-apoptotic proteins. Diabetes markedly increased apoptotic protein levels and the effect did not reversed by IPreC. Conclusions We could suggest that IPreC attenuates myocardial injury via ameliorating histological findings, activating antioxidant mechanisms, and inducing antiapoptotic activity in diabetic

A comparison of different models of stroke on behaviour and brain morphology.

PubMed

Gonzalez, C L R; Kolb, B

2003-10-01

We compared the effects of three models of permanent ischemia, as well as cortical aspiration, on behaviour and brain morphology. Rats received a stroke either by devascularization or by two different procedures of medial cerebral artery occlusion (MCAO; small vs. large). Animals were trained in a reaching task, forepaw asymmetry, forepaw inhibition, sunflower seed task and tongue extension. Behaviour was assessed 1 week after the lesion and at 2-week intervals for a total of 9 weeks. One week after the surgery all animals were severely impaired on all tasks and although they improved over time they only reached preoperative base lines on tongue extension. Animals with small MCAOs performed better in reaching and sunflower tasks; no other behavioural differences were detected among the groups. Pyramidal cells in forelimb and cingulate areas as well as spiny neurons of the striatum were examined for dendritic branching and spine density using a Golgi-Cox procedure. Each lesion type had a different impact on cell morphology. Overall, different changes (atrophy or hypertrophy) were observed with each kind of lesion and these changes were specific for the region (forelimb, cingulate, striatum) and the condition (intact vs. damaged hemisphere). These results suggest that: (i) different lesions to the motor cortex produce subtle differences in behaviour, and (ii) the method used to induce the lesion produces striking differences in cortical and subcortical plasticity.

Regulatory CD8+CD122+ T-cells predominate in CNS after treatment of experimental stroke in male mice with IL-10-secreting B-cells

PubMed Central

Lapato, Andrew; Vandenbark, Arthur A.; Murphy, Stephanie J.; Saugstad, Julie A.; Offner, Halina

2014-01-01

Clinical stroke induces inflammatory processes leading to cerebral and splenic injury and profound peripheral immunosuppression. IL-10 expression is elevated during major CNS diseases and limits inflammation in the brain. Recent evidence demonstrated that transfer of IL-10+ B-cells reduced infarct volume in male C57BL/6J (wild-type, WT) recipient mice when given 24 h prior to or 4 h after middle cerebral artery occlusion (MCAO). The purpose of this study was to determine if passively transferred IL-10+ B-cells can exert therapeutic and immunoregulatory effects when injected 24 hours after MCAO induction in B-cell-sufficient male WT mice. The results demonstrated that IL-10+ B-cell treated mice had significantly reduced infarct volumes in the ipsilateral cortex and hemisphere and improved neurological deficits vs. Vehicle-treated control mice after 60 min occlusion and 96 h of reperfusion. The MCAO-protected B-cell recipient mice had less splenic atrophy and reduced numbers of activated, inflammatory T-cells, decreased infiltration of T-cells and a less inflammatory milieu in the ischemic hemispheres compared with Vehicle-treated control mice. These immunoregulatory changes occurred in concert with the predominant appearance of IL-10-secreting CD8+CD122+ Treg cells in both the spleen and the MCAO-affected brain hemisphere. This study for the first time demonstrates a major neuroprotective role for IL-10+ B-cells in treating MCAO in male WT mice at a time point well beyond the ~4 h tPA treatment window, leading to the generation of a dominant IL-10+CD8+CD122+ Treg population associated with spleen preservation and reduced CNS inflammation. PMID:25537181

Occlusal wear and occlusal condition in a convenience sample of young adults.

PubMed

Van't Spijker, A; Kreulen, C M; Bronkhorst, E M; Creugers, N H J

2015-01-01

To study progression of tooth wear quantitatively in a convenient sample of young adults and to assess possible correlations with occlusal conditions. Twenty-eight dental students participated in a three-year follow up study on tooth wear. Visible wear facets on full arch gypsum casts were assessed using a flatbed scanner and measuring software. Regression analyses were used to assess possible associations between the registered occlusal conditions 'occlusal guidance scheme', 'vertical overbite', 'horizontal overbite', 'depth of sagittal curve', 'canine Angle class relation', 'history of orthodontic treatment', and 'self-reported grinding/clenching' (independent variables) and increase of wear facets (dependent variable). Mean increase in facet surface areas ranged from 1.2 mm2 (premolars, incisors) to 3.4 mm2 (molars); the relative increase ranged from 15% to 23%. Backward regression analysis showed no significant relation for 'group function', 'vertical overbite', 'depth of sagittal curve', 'history of orthodontic treatment' nor 'self-reported clenching. The final multiple linear regression model showed significant associations amongst 'anterior protected articulation' and 'horizontal overbite' and increase of facet surface areas. For all teeth combined, only 'anterior protected articulation' had a significant effect. 'Self reported grinding' did not have a significant effect (p>0.07). In this study 'anterior protected articulation' and 'horizontal overbite', were significantly associated with the progression of tooth wear. Self reported grinding was not significantly associated with progression of tooth wear. Occlusal conditions such as anterior protected articulation and horizontal overbite seem to have an effect on the progression of occlusal tooth wear in this convenient sample of young adults. Copyright © 2014 Elsevier Ltd. All rights reserved.

Reconstruction-Based Digital Dental Occlusion of the Partially Edentulous Dentition.

PubMed

Zhang, Jian; Xia, James J; Li, Jianfu; Zhou, Xiaobo

2017-01-01

Partially edentulous dentition presents a challenging problem for the surgical planning of digital dental occlusion in the field of craniomaxillofacial surgery because of the incorrect maxillomandibular distance caused by missing teeth. We propose an innovative approach called Dental Reconstruction with Symmetrical Teeth (DRST) to achieve accurate dental occlusion for the partially edentulous cases. In this DRST approach, the rigid transformation between two symmetrical teeth existing on the left and right dental model is estimated through probabilistic point registration by matching the two shapes. With the estimated transformation, the partially edentulous space can be virtually filled with the teeth in its symmetrical position. Dental alignment is performed by digital dental occlusion reestablishment algorithm with the reconstructed complete dental model. Satisfactory reconstruction and occlusion results are demonstrated with the synthetic and real partially edentulous models.

Reconstruction-based Digital Dental Occlusion of the Partially Edentulous Dentition

PubMed Central

Zhang, Jian; Xia, James J.; Li, Jianfu; Zhou, Xiaobo

2016-01-01

Partially edentulous dentition presents a challenging problem for the surgical planning of digital dental occlusion in the field of craniomaxillofacial surgery because of the incorrect maxillomandibular distance caused by missing teeth. We propose an innovative approach called Dental Reconstruction with Symmetrical Teeth (DRST) to achieve accurate dental occlusion for the partially edentulous cases. In this DRST approach, the rigid transformation between two symmetrical teeth existing on the left and right dental model is estimated through probabilistic point registration by matching the two shapes. With the estimated transformation, the partially edentulous space can be virtually filled with the teeth in its symmetrical position. Dental alignment is performed by digital dental occlusion reestablishment algorithm with the reconstructed complete dental model. Satisfactory reconstruction and occlusion results are demonstrated with the synthetic and real partially edentulous models. PMID:26584502

Ebselen reduces autophagic activation and cell death in the ipsilateral thalamus following focal cerebral infarction.

PubMed

Li, Yiliang; Zhang, Jian; Chen, Li; Xing, Shihui; Li, Jingjing; Zhang, Yusheng; Li, Chuo; Pei, Zhong; Zeng, Jinsheng

2015-07-23

Previous studies have demonstrated that both oxidative stress and autophagy play important roles in secondary neuronal degeneration in the ipsilateral thalamus after distal middle cerebral artery occlusion (MCAO). This study aimed to investigate whether oxidative stress is associated with autophagy activation within the ipsilateral thalamus after distal MCAO. Sixty stroke-prone renovascular hypertensive rats were subjected to distal MCAO or sham operation, and were killed at 14 days after MCAO. Mn-SOD, LC3-II, Beclin-1 and p62 expression were evaluated by immunostaining and immunoblotting. Secondary damage in the thalamus was assessed with Nissl staining and immunostaining. The association of oxidative stress with autophagy activation was investigated by the antioxidant, ebselen. We found that treatment with ebselen at 24h after MCAO significantly reduced the expression of Mn-SOD in the ipsilateral thalamus at 14 days following focal cerebral infarction. In parallel, it prevented the elevation of LC3-II and Beclin-1, and the reduction of p62. Furthermore, ebselen attenuated the neuronal loss and gliosis in the ipsilateral thalamus. These results suggested that ebselen reduced oxidative stress, autophagy activation and secondary damage in the ipsilateral thalamus following MCAO. There are associations between oxidative stress, autophagy activation and secondary damage in the thalamus after MCAO. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Magnetic resonance imaging detection of multiple ischemic injury produced in an adult rat model of minor stroke followed by mild transient cerebral ischemia.

PubMed

Tuor, Ursula I; Qiao, Min

2017-04-01

To determine whether cumulative brain damage produced adjacent to a minor stroke that is followed by a mild transient ischemia is detectable with MRI and histology, and whether acute or chronic recovery between insults influences this damage. A minor photothrombotic (PT) stroke was followed acutely (1-2 days) or chronically (7 days) by a mild transient middle cerebral artery occlusion (tMCAO). MRI was performed after each insult, followed by final histology. The initial PT produced small hyperintense T 2 and DW infarct lesions and peri-lesion regions of scattered necrosis and modestly increased T 2 . Following tMCAO, in a slice and a region adjacent to the PT, a region of T 2 augmentation was observed when recovery between insults was acute but not chronic. Within the PT slice, a modest region of exacerbated T 2 change proximate to the PT was also observed in the chronic group. Corresponding histological changes within regions of augmented T 2 included increased vacuolation and cell death. Within regions adjacent to an experimental minor stroke, a recurrence of a mild transient cerebral ischemia augmented T 2 above increases produced by tMCAO alone, reflecting increased damage in this region. Exacerbation appeared broader with acute versus chronic recovery between insults.

Effect of electroacupuncture on the expression of interlukin-1beta mRNA after transient focal cerebral ischemia.

PubMed

Xu, Zhen-Feng; Wu, Gen-Cheng; Cao, Xiao-Ding

2002-01-01

It has been reported that interleukin-1beta (IL-1beta ) play a key role in the pathogenesis of cerebral ischemia. Acupuncture is an effective traditional medical therapy in China. The aim of present study was to evaluate the effect of electroacupuncture (EA) on IL-1beta mRNA expression after middle cerebral artery occlusion (MCAO) in rats. Using in situ hybridization technique, it was found that in the MCAO group the expression of IL-1beta mRNA was significantly increased at 2h, 6h, 12h after reperfusion in cerebral ischemic cortex compared with normal group. In EA+ MCAO group the expression of IL-1beta mRNA was significantly decreased at 2h, 6h and 12h in ischemic cortex compared with MCAO group. The results indicated that EA might decrease the IL-1beta protein expression by reducing the IL-beta mRNA expression in ischemic cortex.

Occlusal factors are not related to self-reported bruxism.

PubMed

Manfredini, Daniele; Visscher, Corine M; Guarda-Nardini, Luca; Lobbezoo, Frank

2012-01-01

To estimate the contribution of various occlusal features of the natural dentition that may identify self-reported bruxers compared to nonbruxers. Two age- and sex-matched groups of self-reported bruxers (n = 67) and self-reported nonbruxers (n = 75) took part in the study. For each patient, the following occlusal features were clinically assessed: retruded contact position (RCP) to intercuspal contact position (ICP) slide length (< 2 mm was considered normal), vertical overlap (< 0 mm was considered an anterior open bite; > 4 mm, a deep bite), horizontal overlap (> 4 mm was considered a large horizontal overlap), incisor dental midline discrepancy (< 2 mm was considered normal), and the presence of a unilateral posterior crossbite, mediotrusive interferences, and laterotrusive interferences. A multiple logistic regression model was used to identify the significant associations between the assessed occlusal features (independent variables) and self-reported bruxism (dependent variable). Accuracy values to predict self-reported bruxism were unacceptable for all occlusal variables. The only variable remaining in the final regression model was laterotrusive interferences (P = .030). The percentage of explained variance for bruxism by the final multiple regression model was 4.6%. This model including only one occlusal factor showed low positive (58.1%) and negative predictive values (59.7%), thus showing a poor accuracy to predict the presence of self-reported bruxism (59.2%). This investigation suggested that the contribution of occlusion to the differentiation between bruxers and nonbruxers is negligible. This finding supports theories that advocate a much diminished role for peripheral anatomical-structural factors in the pathogenesis of bruxism.

Biomechanics of occlusion--implications for oral rehabilitation.

PubMed

Peck, C C

2016-03-01

The dental occlusion is an important aspect of clinical dentistry; there are diverse functional demands ranging from highly precise tooth contacts to large crushing forces. Further, there are dogmatic, passionate and often diverging views on the relationship between the dental occlusion and various diseases and disorders including temporomandibular disorders, non-carious cervical lesions and tooth movement. This study provides an overview of the biomechanics of the masticatory system in the context of the dental occlusion's role in function. It explores the adaptation and precision of dental occlusion, its role in bite force, jaw movement, masticatory performance and its influence on the oro-facial musculoskeletal system. Biomechanics helps us better understand the structure and function of biological systems and consequently an understanding of the forces on, and displacements of, the dental occlusion. Biomechanics provides insight into the relationships between the dentition, jaws, temporomandibular joints, and muscles. Direct measurements of tooth contacts and forces are difficult, and biomechanical models have been developed to better understand the relationship between the occlusion and function. Importantly, biomechanical research will provide knowledge to help correct clinical misperceptions and inform better patient care. The masticatory system demonstrates a remarkable ability to adapt to a changing biomechanical environment and changes to the dental occlusion or other components of the musculoskeletal system tend to be well tolerated. © 2015 John Wiley & Sons Ltd.

THR-18, a 18-mer peptide derived from PAI-1, is neuroprotective and improves thrombolysis by tPA in rat stroke models.

PubMed

Krakovsky, M; Polianski, V; Nimrod, A; Higazi, A; Leker, R R; Lamensdorf, I

2011-11-01

The thrombolytic treatment of stroke is limited by a narrow therapeutic time window and is associated with significant adverse side effects. To improve this situation, the modulation of tissue-type plasminogen activator (tPA) activity by a synthetic plasminogen activator inhibitor-1-derived 18-mer peptide (THR-18) was examined in two models of stroke in rats. In the first model (thromboembolic), stroke was induced by intra-carotid injection of micro-clots to rats, and tPA (6 mg/kg) was intravenously infused for 30 minutes with or without THR-18 (1 mg/kg) at 4 hours post-induction. In the second model [transient middle cerebral artery occlusion (tMCAO)], stroke was induced for 2 hours by a transient mechanical occlusion. tPA and/or THR-18 (0.02, 0.1, and 1 mg/kg) were intravenously infused for 60 minutes at the time of reperfusion. In the thromboembolic model, cerebral blood flow, measured before and up to 5.5 hours post-induction, revealed that tPA administration caused reperfusion of flow at 30 minutes post-infusion. Later on, an additional increase in reperfusion was seen in the tPA+THR-18 group, and not with tPA alone. In both models, the frequency of intracranial hemorrhage in the tPA-treated group was found to be significantly higher than the control, and this tPA effect was attenuated by THR-18. In the thromboembolic study, infarct size and brain edema were similar in the control and tPA-treated rats. However, the combination of tPA and THR-18 caused a statistically significant reduction in both parameters (infarct size 17.8 versus 25.0%, brain edema 5 versus 8%, tPA+THR-18 versus control, respectively). In the tMCAO mechanical model, infarct size and brain edema were both increased by tPA treatment as compared to the control group, and this increase was markedly diminished by THR-18 co-administration. Neurobehavioral assessment of the tMCAO animals performed at 72 hours post-stroke induction revealed significant improvements (P<0.05-0.01) in neuroscores in

Effects of cicletanine in the left circumflex coronary artery occlusion-reperfusion canine model of sudden death: analysis of 107 experiments using Cox's proportional hazards model.

PubMed

Jouve, R; Puddu, P E; Langlet, F; Lanti, M; Guillen, J C; Rolland, P H; Serradimigni, A

1988-01-01

Multivariate analysis of survival using Cox's proportional hazards model demonstrates that several clinically measurable covariates are determinants of life-threatening arrhythmias following left circumflex coronary artery occlusion-reperfusion in 107 dogs. These are heart rate, ST segment elevation and mean aortic pressure immediately (3 min) following occlusion, and the presence of early (0-10 min) post-occlusion sustained ventricular tachycardia. The risk of occlusion-reperfusion ventricular fibrillation was determined according to Cox's solution based on ST segment elevation, thus enabling quantification of the role of cicletanine. Since cicletanine-treated dogs had reduced mean ST segment elevation at 3 min post-occlusion, lower incidence of early post-occlusion (0-10 min) sustained ventricular tachycardia, and increased endogenous production of prostacyclin, and the latter was inversely correlated with the level of ST segment elevation, it is concluded that such favourable effects on the ischaemic myocardium were contributory to the improved outcome in these experiments. These effects on the ischaemic myocardium obtained in spite of a hypotensive action in the experimental setting might be regarded as desirable and it is therefore suggested that they should be further investigated by pharmacodynamic studies in human subjects.

Osthole prevents cerebral ischemia-reperfusion injury via the Notch signaling pathway.

PubMed

Guan, Junhong; Wei, Xiangtai; Qu, Shengtao; Lv, Tao; Fu, Qiang; Yuan, Ye

2017-08-01

Stroke is a common cerebrovascular disease in aging populations, and constitutes the second highest principle cause of mortality and the principle cause of permanent disability, and ischemic stroke is the primary form. Osthole is a coumarin derivative extracted from the fruits of Cnidium monnieri (L.) Cusson. In this study, we established a rat model of middle cerebral artery occlusion/reperfusion (MCAO/R) in vivo and found that MCAO/R caused cerebral infarction, hippocampus neuronal injury and apoptosis, and also activated the Notch 1 signaling pathway. However, treatment with osthole further enhanced the activity of Notch 1 signaling and reduced the cerebral infarction as well as the hippocampus neuronal injury and apoptosis induced by MCAO/R in a dose-dependent manner. The same results were observed in a primary neuronal oxygen glucose deficiency/reperfusion (OGD/R) model in vitro, and the effect of osthole could be blocked by an inhibitor of Notch 1 signaling, N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine tert-butyl ester (DAPT). Therefore, we demonstrated that osthole injection prevented rat ischemia-reperfusion injury via activating the Notch 1 signaling pathway in vivo and in vitro in a dose-dependent manner, which may be significant for clinical treatment of ischemic stroke.

Neuroprotection by glutamate oxaloacetate transaminase in ischemic stroke: an experimental study

PubMed Central

Campos, Francisco; Sobrino, Tomás; Ramos-Cabrer, Pedro; Argibay, Bárbara; Agulla, Jesús; Pérez-Mato, María; Rodríguez-González, Raquel; Brea, David; Castillo, José

2011-01-01

As ischemic stroke is associated with an excessive release of glutamate into the neuronal extracellular space, a decrease in blood glutamate levels could provide a mechanism to remove it from the brain tissue, by increasing the brain–blood gradient. In this regard, the ability of glutamate oxaloacetate transaminase (GOT) to metabolize glutamate in blood could represent a potential neuroprotective tool for ischemic stroke. This study aimed to determine the neuroprotective effects of GOT in an animal model of cerebral ischemia by means of a middle cerebral arterial occlusion (MCAO) following the Stroke Therapy Academic Industry Roundtable (STAIR) group guidelines. In this animal model, oxaloacetate-mediated GOT activation inhibited the increase of blood and cerebral glutamate after MCAO. This effect is reflected in a reduction of infarct size, smaller edema volume, and lower sensorimotor deficits with respect to controls. Magnetic resonance spectroscopy confirmed that the increase of glutamate levels in the brain parenchyma after MCAO is inhibited after oxaloacetate-mediated GOT activation. These findings show the capacity of the GOT to remove glutamate from the brain by means of blood glutamate degradation, and suggest the applicability of this enzyme as an efficient and novel neuroprotective tool against ischemic stroke. PMID:21266983

Niche astrocytes promote the survival, proliferation and neuronal differentiation of co-transplanted neural stem cells following ischemic stroke in rats

PubMed Central

Luo, Li; Guo, Kaihua; Fan, Wenguo; Lu, Yinghong; Chen, Lizhi; Wang, Yang; Shao, Yijia; Wu, Gongxiong; Xu, Jie; Lü, Lanhai

2017-01-01

Niche astrocytes have been reported to promote neuronal differentiation through juxtacrine signaling. However, the effects of astrocytes on neuronal differentiation following ischemic stroke are not fully understood. In the present study, transplanted astrocytes and neural stem cells (NSCs) were transplanted into the ischemic striatum of transient middle cerebral artery occlusion (MCAO) model rats 48 h following surgery. It was observed that the co-transplantation of astrocytes and NSCs resulted in a higher ratio of survival and proliferation of the transplanted NSCs, and neuronal differentiation, in MCAO rats compared with NSC transplantation alone. These results demonstrate that the co-administration of astrocytes promotes the survival and neuronal differentiation of NSCs in the ischemic brain. These results suggest that the co-transplantation of astrocytes and NSCs is more effective than NSCs alone in the production of neurons following ischemic stroke in rats. PMID:28352345

Neuroprotective Efficacy of an Aminopropyl Carbazole Derivative P7C3-A20 in Ischemic Stroke.

PubMed

Wang, Shu-Na; Xu, Tian-Ying; Wang, Xia; Guan, Yun-Feng; Zhang, Sai-Long; Wang, Pei; Miao, Chao-Yu

2016-09-01

NAMPT is a novel therapeutic target of ischemic stroke. The aim of this study was to investigate the effect of a potential NAMPT activator, P7C3-A20, an aminopropyl carbazole derivative, on ischemic stroke. In vitro study, neuron protection effect of P7C3-A20 was investigated by co-incubation with primary neurons subjected to oxygen-glucose deprivation (OGD) or oxygen-glucose deprivation/reperfusion (OGD/R) injury. In vivo experiment, P7C3-A20 was administrated in middle cerebral artery occlusion (MCAO) rats and infarct volume was examined. Lastly, the brain tissue nicotinamide adenine dinucleotide (NAD) levels were detected in P7C3-A20 treated normal or MCAO mice. Cell viability, morphology, and Tuj-1 staining confirmed the neuroprotective effect of P7C3-A20 in OGD or OGD/R model. P7C3-A20 administration significantly reduced cerebral infarction in MCAO rats. Moreover, brain NAD levels were elevated both in normal and MCAO mice after P7C3-A20 treatment. P7C3-A20 has neuroprotective effect in cerebral ischemia. The study contributes to the development of NAMPT activators against ischemic stroke and expands the horizon of the neuroprotective effect of aminopropyl carbazole chemicals. © 2016 John Wiley & Sons Ltd.

Mechanism of vaso-occlusion in sickle cell anemia

NASA Astrophysics Data System (ADS)

Lei, Huan; Karniadakis, George

2012-11-01

Vaso-occlusion crisis is one of the key hallmark of sickle cell anemia. While early studies suggested that the crisis is caused by blockage of a single elongated cell, recent experimental investigations indicate that vaso-occlusion is a complex process triggered by adhesive interactions among different cell groups in multiple stages. Based on dissipative particle dynamics, a multi-scale model for the sickle red blood cells (SS-RBCs), accounting for diversity in both shapes and cell rigidities, is developed to investigate the mechanism of vaso-occlusion crisis. Using this model, the adhesive dynamics of single SS-RBC was investigated in arterioles. Simulation results indicate that the different cell groups (deformable SS2 RBCs, rigid SS4 RBCs, leukocytes, etc.) exhibit heterogeneous adhesive behavior due to the different cell morphologies and membrane rigidities. We further simulate the tube flow of SS-RBC suspensions with different cell fractions. The more adhesive SS2 cells interact with the vascular endothelium and further trap rigid SS4 cells, resulting in vaso-occlusion in vessels less than 15 μm . Under inflammation, adherent leukocytes may also trap SS4 cells, resulting in vaso-occlusion in even larger vessels. This work was supported by the NSF grant CBET-0852948 and the NIH grant R01HL094270.

Virtual occlusal definition for orthognathic surgery.

PubMed

Liu, X J; Li, Q Q; Zhang, Z; Li, T T; Xie, Z; Zhang, Y

2016-03-01

Computer-assisted surgical simulation is being used increasingly in orthognathic surgery. However, occlusal definition is still undertaken using model surgery with subsequent digitization via surface scanning or cone beam computed tomography. A software tool has been developed and a workflow set up in order to achieve a virtual occlusal definition. The results of a validation study carried out on 60 models of normal occlusion are presented. Inter- and intra-user correlation tests were used to investigate the reproducibility of the manual setting point procedure. The errors between the virtually set positions (test) and the digitized manually set positions (gold standard) were compared. The consistency in virtual set positions performed by three individual users was investigated by one way analysis of variance test. Inter- and intra-observer correlation coefficients for manual setting points were all greater than 0.95. Overall, the median error between the test and the gold standard positions was 1.06mm. Errors did not differ among teeth (F=0.371, P>0.05). The errors were not significantly different from 1mm (P>0.05). There were no significant differences in the errors made by the three independent users (P>0.05). In conclusion, this workflow for virtual occlusal definition was found to be reliable and accurate. Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

The neuroprotective properties of the superoxide dismutase mimetic tempol correlate with its ability to reduce pathological glutamate release in a rodent model of stroke

PubMed Central

Dohare, Preeti; Hyzinski-García, María C.; Vipani, Aarshi; Bowens, Nicole H.; Nalwalk, Julia W.; Feustel, Paul J.; Keller, Richard W.; Jourd’heuil, David; Mongin, Alexander A.

2014-01-01

The contribution of oxidative stress to ischemic brain damage is well established. Nevertheless, for unknown reasons, several clinically tested antioxidant therapies failed to show benefits in human stroke. Based on our previous in vitro work, we hypothesized that the neuroprotective potency of antioxidants is related to their ability to limit release of the excitotoxic amino acids, glutamate and aspartate. We explored the effects of two antioxidants, tempol and edaravone, on amino acid release in the brain cortex, in a rat model of transient occlusion of the middle cerebral artery (MCAo). Amino acid levels were quantified using a microdialysis approach, with the probe positioned in the ischemic penumbra as verified by a laser Doppler technique. Two-hour MCAo triggered a dramatic increase in the levels of glutamate, aspartate, taurine and alanine. Microdialysate delivery of 10 mM tempol reduced the amino acid release by 60–80%, while matching levels of edaravone had no effect. In line with these latter data, an intracerebroventri-cular injection of tempol but not edaravone (500 nmols each, 15 minutes prior to MCAo) reduced infarction volumes by ~50% and improved neurobehavioral outcomes. In vitro assays showed that tempol was superior in removing superoxide anion, whereas edaravone was more potent in scavenging hydrogen peroxide, hydroxyl radical, and peroxynitrite. Overall, our data suggests that the neuroprotective properties of tempol are likely related to its ability to reduce tissue levels of the superoxide anion and pathological glutamate release, and, in such a way, limit progression of brain infarction within ischemic penumbra. These new findings may be instrumental in developing new antioxidant therapies for treatment of stroke. PMID:25224033

Neuroprotection by dimethyloxalylglycine following permanent and transient focal cerebral ischemia in rats

PubMed Central

Nagel, Simon; Papadakis, Michalis; Chen, Ruoli; Hoyte, Lisa C; Brooks, Keith J; Gallichan, Daniel; Sibson, Nicola R; Pugh, Chris; Buchan, Alastair M

2011-01-01

Dimethyloxalylglycine (DMOG) is an inhibitor of prolyl-4-hydroxylase domain (PHD) enzymes that regulate the stability of hypoxia-inducible factor (HIF). We investigated the effect of DMOG on the outcome after permanent and transient middle cerebral artery occlusion (p/tMCAO) in the rat. Before and after pMCAO, rats were treated with 40 mg/kg, 200 mg/kg DMOG, or vehicle, and with 40 mg/kg or vehicle after tMCAO. Serial magnetic resonance imaging (MRI) was performed to assess infarct evolution and regional cerebral blood flow (rCBF). Both doses significantly reduced infarct volumes, but only 40 mg/kg improved the behavior after 24 hours of pMCAO. Animals receiving 40 mg/kg were more likely to maintain rCBF values above 30% from the contralateral hemisphere within 24 hours of pMCAO. DMOG after tMCAO significantly reduced the infarct volumes and improved behavior at 24 hours and 8 days and also improved the rCBF after 24 hours. A consistent and significant upregulation of both mRNA and protein levels of vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) was associated with the observed neuroprotection, although this was not consistently related to HIF-1α levels at 24 hours and 8 days. Thus, DMOG afforded neuroprotection both at 24 hours after pMCAO and at 24 hours and 8 days after tMCAO. This effect was associated with an increase of VEGF and eNOS and was mediated by improved rCBF after DMOG treatment. PMID:20407463

Analysis of decrease in lung perfusion blood volume with occlusive and non-occlusive pulmonary embolisms.

PubMed

Ikeda, Yohei; Yoshimura, Norihiko; Hori, Yoshiro; Horii, Yosuke; Ishikawa, Hiroyuki; Yamazaki, Motohiko; Noto, Yoshiyuki; Aoyama, Hidefumi

2014-12-01

The aim of this study was to determine if lung perfusion blood volume (lung PBV) with non-occlusive pulmonary embolism (PE) differs quantitatively and visually from that with occlusive PE and to investigate if lung PBV with non-occlusive PE remains the same as that without PE. Totally, 108 patients suspected of having acute PE underwent pulmonary dual-energy computed tomography angiography (DECTA) between April 2011 and January 2012. Presence of PE on DECTA was evaluated by one radiologist. Two radiologists visually evaluated the PE distribution (segmental or subsegmental) and its nature (occlusive or non-occlusive) on DECTA and classified perfusion in lung PBV as "decreased," "slightly decreased," and "preserved". Two radiologists used a lung PBV application to set a region of interest (ROI) in the center of the lesion and measured HU values of an iodine map. In the same slice as the ROI of the lesion and close to the lesion, another ROI was set in the normal perfusion area without PE, and HUs were measured. The proportion of lesions was compared between the occlusive and non-occlusive groups. HUs were compared among the occlusive, non-occlusive, and corresponding normal groups. Twenty-five patients had 80 segmental or subsegmental lesions. There were 37 and 43 lesions in the occlusive and non-occlusive groups, respectively. The proportion of decreased lesions was 73.0% (27/37) in the occlusive group, while that of preserved lesions in the non-occlusive group was 76.7% (33/43). There was a significant difference in the proportion of lesions (P<0.001) between the two groups. HUs of the iodine map were significantly higher in the non-occlusive group than in the occlusive group (33.8 ± 8.2 HU vs. 11.9 ± 6.1 HU, P<0.001). There was no significant difference in HUs for the entire lesion between the non-occlusive (33.8 ± 8.2 HU) and corresponding normal group (34.5 ± 6.8 HU; P=0.294). Iodine perfusion tended to be visually and quantitatively preserved in lungs with

Are V1 Simple Cells Optimized for Visual Occlusions? A Comparative Study

PubMed Central

Bornschein, Jörg; Henniges, Marc; Lücke, Jörg

2013-01-01

Simple cells in primary visual cortex were famously found to respond to low-level image components such as edges. Sparse coding and independent component analysis (ICA) emerged as the standard computational models for simple cell coding because they linked their receptive fields to the statistics of visual stimuli. However, a salient feature of image statistics, occlusions of image components, is not considered by these models. Here we ask if occlusions have an effect on the predicted shapes of simple cell receptive fields. We use a comparative approach to answer this question and investigate two models for simple cells: a standard linear model and an occlusive model. For both models we simultaneously estimate optimal receptive fields, sparsity and stimulus noise. The two models are identical except for their component superposition assumption. We find the image encoding and receptive fields predicted by the models to differ significantly. While both models predict many Gabor-like fields, the occlusive model predicts a much sparser encoding and high percentages of ‘globular’ receptive fields. This relatively new center-surround type of simple cell response is observed since reverse correlation is used in experimental studies. While high percentages of ‘globular’ fields can be obtained using specific choices of sparsity and overcompleteness in linear sparse coding, no or only low proportions are reported in the vast majority of studies on linear models (including all ICA models). Likewise, for the here investigated linear model and optimal sparsity, only low proportions of ‘globular’ fields are observed. In comparison, the occlusive model robustly infers high proportions and can match the experimentally observed high proportions of ‘globular’ fields well. Our computational study, therefore, suggests that ‘globular’ fields may be evidence for an optimal encoding of visual occlusions in primary visual cortex. PMID:23754938

Traditional Mongolian medicine Eerdun Wurile improves stroke recovery through regulation of gene expression in rat brain.

PubMed

Gaowa, Saren; Bao, Narisi; Da, Man; Qiburi, Qiburi; Ganbold, Tsogzolmaa; Chen, Lu; Altangerel, Altanzul; Temuqile, Temuqile; Baigude, Huricha

2018-05-16

Eerdun Wurile (EW) is one of the key Mongolian medicines for treatment of neurological and cardiological disorders. EW is ranked most regularly used Mongolian medicine in clinic. Components of EW which mainly originate from natural products are well defined and are unique to Mongolian medicine. Although the recipe of EW contains known neuroactive chemicals originated from plants, its mechanism of action has never been elucidated at molecular level. The objective of the present study is to explore the mechanism of neuroregenerative activity of EW by focusing on the regulation of gene expression in the brain of rat model of stroke. Rat middle cerebral artery occlusion (MCAO) models were treated with EW for 15 days. Then, total RNAs from the cerebral cortex of rat MCAO models treated with either EW or control (saline) were extracted and analyzed by transcriptome sequencing. Differentially expressed genes were analyzed for their functions during the recovery of ischemic stroke. The expression level of significantly differentially expressed genes such as growth factors, microglia markers and secretive enzymes in the lesion was further validated by RT-qPCR and immunohistochemistry. Previously identified neuroactive compounds, such as geniposide (Yu et al., 2009), myristicin (Shin et al., 1988), costunolide (Okugawa et al., 1996), toosendanin (Shi and Chen, 1999) were detected in EW formulation. Bederson scale indicated that the treatment of rat MCAO models with EW showed significantly lowered neurological deficits (p < 0.01). The regional cerebral blood circulation was also remarkably higher in rat MCAO models treated with EW compared to the control group. A total of 186 genes were upregulated in the lesion of rat MCAO models treated with EW compared to control group. Among them, growth factors such as Igf1 (p < 0.05), Igf2 (p < 0.01), Grn (p < 0.01) were significantly upregulated in brain after treatment of rat MCAO models with EW. Meanwhile, greatly

Effect of occlusion amblyopia after prescribed full-time occlusion on long-term visual acuity outcomes.

PubMed

Longmuir, Susannah; Pfeifer, Wanda; Scott, William; Olson, Richard

2013-01-01

To investigate the incidence and characteristics of occlusion amblyopia with prescribed full-time patching and determine its effect on long-term visual acuity outcomes. The records of patients younger than 10 years diagnosed as having amblyopia between 1970 and 2000 were retrospectively reviewed. Patients were prescribed full-time occlusion and observed until completion of therapy. Of 597 patients treated for amblyopia by full-time patching, 115 were diagnosed as having occlusion amblyopia (19.3%). Seventy-five percent (86 of 115) developed occlusion amblyopia during the first episode of full-time patching. Occlusion amblyopia occurred more frequently in children prescribed full-time patching at an earlier age (P = .0002), with an odds ratio of 8.56 (95% confidence interval: 2.73, 26.84) in children younger than 36 months and 2.66 (95% confidence interval: 0.96, 7.37) in children between 36 and 59 months old. Seven of the patients with occlusion amblyopia did not reverse fixation and continued to fixate with the initially amblyopic eye after treatment. Final visual acuity in these eyes with occlusion amblyopia was 20/30 or better. After cessation of treatment, the final interocular difference in visual acuity was less in patients with a history of occlusion amblyopia (P = .003). Occlusion amblyopia occurred at all ages, but the incidence decreased with increasing age. Patients who developed occlusion amblyopia with prescribed full-time occlusion had less interocular visual acuity difference than patients who did not, suggesting that development of occlusion amblyopia can indicate the potential for the development of better vision in the originally amblyopic eye. Copyright 2013, SLACK Incorporated.

Ferulic acid attenuates focal cerebral ischemia-induced decreases in p70S6 kinase and S6 phosphorylation.

PubMed

Koh, Phil-Ok

2013-10-25

Ferulic acid exhibits neuroprotective effects against focal cerebral ischemia. PI3/K and Akt signaling pathways play an essential role in protecting against cerebral ischemia. Mammalian target of rapamycin (mTOR), a major downstream target of Akt, regulates p70S6 kinase and S6, both of which are involved in ribosomal biogenesis and protein synthesis. I investigated whether ferulic acid regulates mTOR, p70S6 kinase, and S6 phosphorylation during brain ischemic injury. Rats were treated immediately with vehicle or ferulic acid (100mg/kg, i.v.) after middle cerebral artery occlusion (MCAO). Brains tissues were removed at 24h after the onset of MCAO and the cerebral cortex regions were collected. Ferulic acid reduced the MCAO-induced infarct volume. I showed previously that ferulic acid prevents the MCAO injury-induced decrease of Akt phosphorylation. In this study, MCAO injury induced decreases in mTOR, p70S6 kinase, and S6 phosphorylation levels, while ferulic acid attenuated the injury-induced decreases. Immunohistochemical staining demonstrated that ferulic acid prevented the MCAO-induced reduction in the number of positive cells for phosphorylated p70S6 kinase and phosphorylated S6. These findings suggest that ferulic acid has a neuroprotective function against focal cerebral ischemia by modulating p70S6 kinase expression and S6 phosphorylation. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Neuronal Sodium Channels in Neurodegeneration and Neuroprotection

DTIC Science & Technology

2002-06-01

following 2 h MCAo/ reperfusion injury Group’ Baselineb 2 h 4 h 6 h $ 24 1h Vehicle 37.0±0.7 38.3±0.7 37.1 ±0.8 37.5 ±0.7 36.6±0.8 RS (0.01 mg/kg) 36.4-±0.3...brain injury caused by middle cerebral neuronal cell death caused by ischemia results from artery occlusion (MCAo) for 2h followed by reperfusion a...expression following cerebral ischemia study, was delayed post- injury (i.e. > 2 -6h post- involves the up-regulation of several gene families injury ). This

Mesenchymal stem cells derived from peripheral blood protects against ischemia.

PubMed

Ukai, Ryo; Honmou, Osamu; Harada, Kuniaki; Houkin, Kiyohiro; Hamada, Hirofumi; Kocsis, Jeffery D

2007-03-01

Intravenous delivery of mesenchymal stem cells (MSCs) prepared from bone marrow (BMSCs) reduces infarction volume and ameliorates functional deficits in a rat cerebral ischemia model. MSC-like multipotent precursor cells (PMSCs) have also been suggested to exist in peripheral blood. To test the hypothesis that treatment with PMSCs may have a therapeutic benefit in stroke, we compared the efficacy of systemic delivery of BMSCs and PMSCs. A permanent middle cerebral artery occlusion (MCAO) in rat was induced by intraluminal vascular occlusion with a microfilament. Rat BMSCs and PMSCs were prepared in culture and intravenously injected into the rats 6 h after MCAO. Lesion size was assessed at 6 h, and 1, 3, and 7 days using MR imaging and histology. The hemodynamic change of cerebral blood perfusion on stroke was assessed the same times using perfusion-weighted image (PWI). Functional outcome was assessed using the treadmill stress test. Both BMSCs and PMSCs treated groups had reduced lesion volume, improved regional cerebral blood flow, and functional improvement compared to the control group. The therapeutic benefits of both MSC-treated groups were similar. These data suggest that PMSCs derived from peripheral blood could be an important cell source of cell therapy for stroke.

4'-O-β-D-Glucosyl-5-O-Methylvisamminol, A Natural Histone H3 Phosphorylation Epigenetic Suppressor, Exerts a Neuroprotective Effect Through PI3K/Akt Signaling Pathway on Focal Cerebral Ischemia in Rats.

PubMed

Chang, Chih-Zen; Wu, Shu-Chuan

2016-05-01

A bursting inflammation has been observed that compromises neurologic function in patients who experience stroke. We sought to examine the neuroprotective efficacy of 4'-O-β-D-glucosyl-5-O-methylvisamminol (OGOMV), a novel histone H3 phosphorylation epigenetic suppressor) in a transient middle cerebral artery occlusion (tMCAO). A rodent tMCAO model was used. Administration with 400 μg/kg/day OGOMV was initiated 12 hours before (prevention) and 1 hour after animals were subjected to tMCAO (reversal). The cerebral cortex was harvested to examine protein kinase B (PI3D/Akt), 5-bromo-2'-deoxyuridine (Western blot), and caspases (reverse-transcription polymerase chain reaction). In addition, cerebrospinal fluid samples were collected to examine interleukin 1-β, interleukin-6, monocyte chemoattractant protein-1, and tumor necrosis factor-α (reverse-transcription polymerase chain reaction). Cortical 5-bromo-2'-deoxyuridine and phospho-PI3D/Akt were reduced in tMCAO animals, compared with the healthy controls but increased in the OGOMV treatment and prevention groups. Activated cortical caspase-3,-6, and -9a as well as increased IL-1β and TNF-α levels were observed in the tMCAO animals (P < 0.05). Both prevention and treatment with OGOMV significantly reduced cleaved caspase-3 and -9a groups, but no significant change in caspase-6 was noted. Perifosine, an Akt inhibitor, was added to reduce the bioexpression of phospho-P13D/Akt, and Bcl-2 level and increased cleaved caspase-9a level in both OGOMV prevention and treatment tMCAO groups (P > 0.05). Our study suggests that OGOMV could exert a neuroprotective effect by inhibiting the P13D/Akt protein, attenuating inflammation, and cleaved caspase-3- and -9a-related apoptosis. This study also lends credence to support the notion that the prevention of OGOMV could attenuate proinflammatory cytokine mRNA and late-onset caspases in tMCAO and merits further study. Copyright © 2016 Elsevier Inc. All rights reserved.

Influence of occlusal contact area on cusp defection and stress distribution.

PubMed

Costa, Anna Karina Figueiredo; Xavier, Thaty Aparecida; Paes-Junior, Tarcisio José Arruda; Andreatta-Filho, Oswaldo Daniel; Borges, Alexandre Luiz Souto

2014-11-01

The purpose of this study was to evaluate the effect of occlusal contact area for loading on the cuspal defection and stress distribution in a first premolar restored with a high elastic modulus restorative material. The Rhinoceros 4.0 software was used for modeling the three-dimensional geometries of dental and periodontal structures and the inlay restoration. Thus, two different models, intact and restored teeth with three occlusal contact areas, 0.1, 0.5 and 0.75 mm(2), on enamel at the occlusal surface of buccal and lingual cusps. Finite element analysis (FEA) was performed with the program ANSYS (Workbench 13.0), which generated a mesh with tetrahedral elements with greater refinement in the regions of interest, and was constrained at the bases of cortical and trabecular bone in all axis and loaded with 100 N normal to each contact area. To analysis of maximum principal stress, the smaller occlusal contact area showed greater compressive stress in region of load application for both the intact and inlay restored tooth. However, tensile stresses at the occlusal isthmus were similar for all three tested occlusal contact areas (60 MPa). To displacement of the cusps was higher for teeth with inlay (0.46-0.48 mm). For intact teeth, the smaller contact area showed greater displacement (0.10 mm). For teeth with inlays, the displacement of the cusps were similar in all types of occlusal area. Cuspal displacement was higher in the restored tooth when compared to the intact tooth, but there were no significant variations even with changes in the occlusal contact area. RELEVANCE CLINICAL: Occlusal contacts have a great influence on the positioning of teeth being able to maintain the position and stability of the mandible. Axial loads would be able to generate more uniform stress at the root presenting a greater concentration of load application in the point and the occlusal surface. Thus, is necessary to analyze the relationship between these occlusal contacts as dental

Rapamycin preconditioning attenuates transient focal cerebral ischemia/reperfusion injury in mice.

PubMed

Yin, Lele; Ye, Shasha; Chen, Zhen; Zeng, Yaoying

2012-12-01

Rapamycin, an mTOR inhibitor and immunosuppressive agent in clinic, has protective effects on traumatic brain injury and neurodegenerative diseases. But, its effects on transient focal ischemia/reperfusion disease are not very clear. In this study, we examined the effects of rapamycin preconditioning on mice treated with middle cerebral artery occlusion/reperfusion operation (MCAO/R). We found that the rapamycin preconditioning by intrahippocampal injection 20 hr before MCAO/R significantly improved the survival rate and longevity of mice. It also decreased the neurological deficit score, infracted areas and brain edema. In addition, rapamycin preconditioning decreased the production of NF-κB, TNF-α, and Bax, but not Bcl-2, an antiapoptotic protein in the ischemic area. From these results, we may conclude that rapamycin preconditioning attenuate transient focal cerebral ischemia/reperfusion injury and inhibits apoptosis induced by MCAO/R in mice.

Prevention of Glutamate Accumulation and Upregulation of Phospho-Akt may Account for Neuroprotection Afforded by Bergamot Essential Oil against Brain Injury Induced by Focal Cerebral Ischemia in Rat.

PubMed

Amantea, Diana; Fratto, Vincenza; Maida, Simona; Rotiroti, Domenicantonio; Ragusa, Salvatore; Nappi, Giuseppe; Bagetta, Giacinto; Corasaniti, Maria Tiziana

2009-01-01

The effects of bergamot essential oil (BEO; Citrus bergamia, Risso) on brain damage caused by permanent focal cerebral ischemia in rat were investigated. Administration of BEO (0.1-0.5 ml/kg but not 1 ml/kg, given intraperitoneally 1 h before occlusion of the middle cerebral artery, MCAo) significantly reduced infarct size after 24 h permanent MCAo. The most effective dose (0.5 ml/kg) resulted in a significant reduction of infarct extension throughout the brain, especially in the medial striatum and the motor cortex as revealed by TTC staining of tissue slices. Microdialysis experiments show that BEO (0.5 ml/kg) did not affect basal amino acid levels, whereas it significantly reduced excitatory amino acid, namely aspartate and glutamate, efflux in the frontoparietal cortex typically observed following MCAo. Western blotting experiments demonstrated that these early effects were associated, 24 h after permanent MCAo, to a significant increase in the phosphorylation and activity of the prosurvival kinase, Akt. Indeed, BEO significantly enhanced the phosphorylation of the deleterious downstream kinase, GSK-3beta, whose activity is negatively regulated via phosphorylation by Akt.

Neuroprotective effect of electroacupuncture and upregulation of hypoxia-inducible factor-1α during acute ischaemic stroke in rats.

PubMed

Li, Ce; Zhang, Tingting; Yu, Kewei; Xie, Hongyu; Bai, Yulong; Zhang, Li; Wu, Yi; Wang, Nianhong

2017-10-01

Acupuncture is a traditional method that has been widely used in various fields of medicine with therapeutic effect. However, evidence of effectiveness to support the application of electroacupuncture (EA) during the process of ischaemia is scarce. To investigate dynamic changes in hypoxia-inducible factor (HIF)-1α expression as well as its association with neurological status in rats subjected to acute ischaemic stroke and EA intervention. Forty adult male rats were randomly divided into three groups that received sham surgery (Control group, n=10) or underwent middle cerebral artery occlusion and EA (MCAO+EA group, n=15) or minimal acupuncture as a control treatment (MCAO+MA group, n=15). The rats in the MCAO+EA and MCAO+MA groups received EA or acupuncture without any electrical current, respectively, during 90 min of ischaemia. Rats in the Control group received the same surgical procedure but without MCAO. EA involved electrical stimulation of needles inserted into the quadriceps at 50 Hz frequency and 3 mA current intensity. Neurological status was evaluated on postoperative day 1, and cerebral infarction volume (IV) and HIF-1α expression 24 hours later. Neurological scores were improved and cerebral IV was decreased in the MCAO+EA group compared to the MCAO+MA group (both p<0.05). Moreover, HIF-1α expression was higher in the MCAO+EA group versus the MCAO+MA group (p<0.05). EA enhanced recovery of neurological function, decreased cerebral IV and increased HIF-1α expression in ischaemic rats. Further research is needed to determine whether EA is effective for stroke treatment through the stimulation of muscle contraction. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Evaluation of Aged Garlic Extract Neuroprotective Effect in a Focal Model of Cerebral Ischemia

NASA Astrophysics Data System (ADS)

Aguilera, Penélope; Maldonado, Perla D.; Ortiz-Plata, Alma; Barrera, Diana; Chánez-Cárdenas, María Elena

2008-02-01

The oxidant species generated in cerebral ischemia have been implicated as important mediators of neuronal injury through damage to lipids, DNA, and proteins. Since ischemia as well as reperfusion insults generate oxidative stress, the administration of antioxidants may limit oxidative damage and ameliorate disease progression. The present work shows the transitory neuroprotective effect of the aged garlic extract (AGE) administration (a proposed antioxidant compound) in a middle cerebral artery occlusion (MCAO) model in rats and established its therapeutic window. To determine the optimal time of administration, animal received AGE (1.2 mL/kg) intraperitoneally 30 min before onset of reperfusion (-0.5 R), at the beginning of reperfusion (0R), or 1 h after onset of reperfusion (1R). Additional doses were administrated after 1, 2, or 3 h after onset of reperfusion. To establish the therapeutic window of AGE, the infarct area was determined for each treatment after different times of reperfusion. Results show that the administration of AGE at the onset of reperfusion reduced the infarct area by 70% (evaluated after 2 h reperfusion). The therapeutic window of AGE was determined. Repeated doses did not extend the temporal window of protection. A significant reduction in the nitrotyrosine level was observed in the brain tissue subjected to MCAO after AGE treatment at the onset of reperfusion. Data in the present work show that AGE exerts a transitory neuroprotective effect in response to ischemia/reperfusion-induced neuronal injury.

Nonlinear dynamic model for visual object tracking on Grassmann manifolds with partial occlusion handling.

PubMed

Khan, Zulfiqar Hasan; Gu, Irene Yu-Hua

2013-12-01

This paper proposes a novel Bayesian online learning and tracking scheme for video objects on Grassmann manifolds. Although manifold visual object tracking is promising, large and fast nonplanar (or out-of-plane) pose changes and long-term partial occlusions of deformable objects in video remain a challenge that limits the tracking performance. The proposed method tackles these problems with the main novelties on: 1) online estimation of object appearances on Grassmann manifolds; 2) optimal criterion-based occlusion handling for online updating of object appearances; 3) a nonlinear dynamic model for both the appearance basis matrix and its velocity; and 4) Bayesian formulations, separately for the tracking process and the online learning process, that are realized by employing two particle filters: one is on the manifold for generating appearance particles and another on the linear space for generating affine box particles. Tracking and online updating are performed in an alternating fashion to mitigate the tracking drift. Experiments using the proposed tracker on videos captured by a single dynamic/static camera have shown robust tracking performance, particularly for scenarios when target objects contain significant nonplanar pose changes and long-term partial occlusions. Comparisons with eight existing state-of-the-art/most relevant manifold/nonmanifold trackers with evaluations have provided further support to the proposed scheme.

In-Depth Proteomic Analysis of the Hippocampus in a Rat Model after Cerebral Ischaemic Injury and Repair by Danhong Injection (DHI)

PubMed Central

Cui, Yiran; Liu, Xin; Li, Xianyu; Yang, Hongjun

2017-01-01

Stroke is the second most common cause of death worldwide. A systematic description and characterization of the strokes and the effects induced in the hippocampus have not been performed so far. Here, we analysed the protein expression in the hippocampus 24 h after cerebral ischaemic injury and repair. Drug intervention using Danhong injection (DHI), which has been reported to have good therapeutic effects in a clinical setting, was selected for our study of cerebral ischaemia repair in rat models. A larger proteome dataset and total 4091 unique proteins were confidently identified in three biological replicates by combining tissue extraction for rat hippocampus and LC-MS/MS analysis. A label-free approach was then used to quantify the differences among the four experimental groups (Naive, Sham, middle cerebral artery occlusion (MCAO) and MCAO + DHI groups) and showed that about 2500 proteins on average were quantified in each of the experiment group. Bioinformatics analysis revealed that in total 280 unique proteins identified above were differentially expressed (P < 0.05). By combining the subcellular localization, hierarchical clustering and pathway information with the results from injury and repair phase, 12 significant expressed proteins were chosen and verified with respect to their potential as candidates for cerebral ischaemic injury by Western blot. The primary three signalling pathways of the candidates related may be involved in molecular mechanisms related to cerebral ischaemic injury. In addition, a glycogen synthase kinase-3β (Gsk-3β) inhibitor of the candidates with the best corresponding expression trends between western blotting (WB) and label-free quantitative results were chosen for further validation. The results of Western blot analysis of protein expression and 2,3,5- chloride three phenyl tetrazole (TTC) staining of rat brains showed that DHI treatment and Gsk-3β inhibitor are both able to confer protection against ischaemic injury in rat

Diagnosis of occlusal dysesthesia utilizing prefrontal hemodynamic activity with slight occlusal interference.

PubMed

Ono, Yumie; Ishikawa, Yu; Munakata, Motohiro; Shibuya, Tomoaki; Shimada, Atsushi; Miyachi, Hideo; Wake, Hiroyuki; Tamaki, Katsushi

2016-11-01

Clinical diagnosis of occlusal dysesthesia (OD), also referred to as phantom bite syndrome, is currently based on the absence of objective occlusal discrepancy despite the persistent complaint of uncomfortable bite sensation. We previously demonstrated that the subjective feeling of occlusal discomfort generated by artificial occlusal interference can be objectively evaluated using prefrontal hemodynamic activity in young healthy individuals. The aim of this study was to investigate whether dental patients with and without OD show distinct prefrontal activity during grinding behavior with an occlusal interference. Six dental patients with OD (OD group) and eight patients without OD (control group) grinded piled occlusal strips placed between their first molars and reported their perception and discomfort thresholds during continuous monitoring of prefrontal hemodynamic activity with a portable functional near-infrared spectroscopy. Although patients without OD showed the typical hemodynamic pattern of increased oxyhemoglobin and reduced deoxyhemoglobin (HHb) concentration, those with OD showed persistent incremental increases of HHb concentration that began at the loading of occlusal strips on their molars before they executed grinding. The intensities of the task-related HHb activities showed statistically significant differences between OD and control groups, particularly at channel 3, arranged over the left frontal pole cortex. When the discrimination criterion was set using the intensity values of channel 3 from both groups, the overall accuracy of the OD discrimination was 92.9%. Although physiological interpretation has yet to be elucidated, the task-related response of an increase in HHb may be a useful neuronal signature to characterize dental patients with OD.

Diagnosis of occlusal dysesthesia utilizing prefrontal hemodynamic activity with slight occlusal interference

PubMed Central

Ishikawa, Yu; Munakata, Motohiro; Shibuya, Tomoaki; Shimada, Atsushi; Miyachi, Hideo; Wake, Hiroyuki; Tamaki, Katsushi

2016-01-01

Clinical diagnosis of occlusal dysesthesia (OD), also referred to as phantom bite syndrome, is currently based on the absence of objective occlusal discrepancy despite the persistent complaint of uncomfortable bite sensation. We previously demonstrated that the subjective feeling of occlusal discomfort generated by artificial occlusal interference can be objectively evaluated using prefrontal hemodynamic activity in young healthy individuals. The aim of this study was to investigate whether dental patients with and without OD show distinct prefrontal activity during grinding behavior with an occlusal interference. Six dental patients with OD (OD group) and eight patients without OD (control group) grinded piled occlusal strips placed between their first molars and reported their perception and discomfort thresholds during continuous monitoring of prefrontal hemodynamic activity with a portable functional near‐infrared spectroscopy. Although patients without OD showed the typical hemodynamic pattern of increased oxyhemoglobin and reduced deoxyhemoglobin (HHb) concentration, those with OD showed persistent incremental increases of HHb concentration that began at the loading of occlusal strips on their molars before they executed grinding. The intensities of the task‐related HHb activities showed statistically significant differences between OD and control groups, particularly at channel 3, arranged over the left frontal pole cortex. When the discrimination criterion was set using the intensity values of channel 3 from both groups, the overall accuracy of the OD discrimination was 92.9%. Although physiological interpretation has yet to be elucidated, the task‐related response of an increase in HHb may be a useful neuronal signature to characterize dental patients with OD. PMID:29744159

An Automatic and Robust Algorithm of Reestablishment of Digital Dental Occlusion

PubMed Central

Chang, Yu-Bing; Xia, James J.; Gateno, Jaime; Xiong, Zixiang; Zhou, Xiaobo; Wong, Stephen T. C.

2017-01-01

In the field of craniomaxillofacial (CMF) surgery, surgical planning can be performed on composite 3-D models that are generated by merging a computerized tomography scan with digital dental models. Digital dental models can be generated by scanning the surfaces of plaster dental models or dental impressions with a high-resolution laser scanner. During the planning process, one of the essential steps is to reestablish the dental occlusion. Unfortunately, this task is time-consuming and often inaccurate. This paper presents a new approach to automatically and efficiently reestablish dental occlusion. It includes two steps. The first step is to initially position the models based on dental curves and a point matching technique. The second step is to reposition the models to the final desired occlusion based on iterative surface-based minimum distance mapping with collision constraints. With linearization of rotation matrix, the alignment is modeled by solving quadratic programming. The simulation was completed on 12 sets of digital dental models. Two sets of dental models were partially edentulous, and another two sets have first premolar extractions for orthodontic treatment. Two validation methods were applied to the articulated models. The results show that using our method, the dental models can be successfully articulated with a small degree of deviations from the occlusion achieved with the gold-standard method. PMID:20529735

Prevention of the collapse of pial collaterals by remote ischemic perconditioning during acute ischemic stroke.

PubMed

Ma, Junqiang; Ma, Yonglie; Dong, Bin; Bandet, Mischa V; Shuaib, Ashfaq; Winship, Ian R

2017-08-01

Collateral circulation is a key variable determining prognosis and response to recanalization therapy during acute ischemic stroke. Remote ischemic perconditioning (RIPerC) involves inducing peripheral ischemia (typically in the limbs) during stroke and may reduce perfusion deficits and brain damage due to cerebral ischemia. In this study, we directly investigated pial collateral flow augmentation due to RIPerC during distal middle cerebral artery occlusion (MCAo) in rats. Blood flow through pial collaterals between the anterior cerebral artery (ACA) and the MCA was assessed in male Sprague Dawley rats using in vivo laser speckle contrast imaging (LSCI) and two photon laser scanning microscopy (TPLSM) during distal MCAo. LSCI and TPLSM revealed that RIPerC augmented collateral flow into distal MCA segments. Notably, while control rats exhibited an initial dilation followed by a progressive narrowing of pial arterioles 60 to 150-min post-MCAo (constricting to 80-90% of post-MCAo peak diameter), this constriction was prevented or reversed by RIPerC (such that vessel diameters increased to 105-110% of post-MCAo, pre-RIPerC diameter). RIPerC significantly reduced early ischemic damage measured 6 h after stroke onset. Thus, prevention of collateral collapse via RIPerC is neuroprotective and may facilitate other protective or recanalization therapies by improving blood flow in penumbral tissue.

Ferulic acid attenuates the down-regulation of MEK/ERK/p90RSK signaling pathway in focal cerebral ischemic injury.

PubMed

Koh, Phil-Ok

2015-02-19

Ferulic acid provides neuroprotective effects against a middle cerebral artery occlusion (MCAO)-induced cerebral ischemia. Mitogen-activated protein kinases can regulate extensive intracellular processes including cell differentiation, growth, and death. This study further investigated whether ferulic acid modulates a protective mechanism through the activation of Raf-MEK-ERK and its downstream targets, including 90 ribosomal S6 kinase (p90RSK) and Bad during cerebral ischemic injury. Male Sprague-Dawley rats were treated with ferulic acid (100mg/kg) or vehicle after the onset of MCAO and brain tissues were collected 24h after MCAO. These results indicated that ferulic acid decreases the volume of the infarct area and the number of cells positive in terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Although MCAO injury induces a decrease in the phosphorylation of Raf-1, MEK1/2, and ERK1/2, ferulic acid treatment prevents the injury-induced decrease in these phosphorylation levels. Ferulic acid also attenuates the injury-induced decrease in p90RSK and Bad phosphorylation levels. These findings suggest that ferulic acid prevents MCAO-induced neuronal cell death and that the MEK-ERK-p90RSK-Bad signaling pathway is involved in these neuroprotective effects. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Nogo-A is involved in secondary axonal degeneration of thalamus in hypertensive rats with focal cortical infarction.

PubMed

Wang, Fang; Liang, Zhijian; Hou, Qinghua; Xing, Shihui; Ling, Li; He, Meixia; Pei, Zhong; Zeng, Jinsheng

2007-05-07

We investigate whether Nogo-A is involved in the secondary axonal degeneration in the thalamus after distal middle cerebral artery occlusion (MCAO) in stroke-prone renovascular hypertensive rats (RHRSP). The expression of Nogo-A in ipsilateral ventroposterior nucleus (VPN) of the thalamus in RHRSP was observed at 1, 2 and 4 weeks after distal MCAO. In addition, intracerebroventricular infusion of NEP1-40, a Nogo-66 receptor (NgR) antagonist peptide, was administered starting 24 h after MCAO and continued for 1, 2 and 4 weeks, respectively. Axonal damage and regeneration were evaluated by analysis of the immunoreactivity (IR) of amyloid betaA4 precursor protein (APP), growth associated protein 43 (GAP-43) and microtubule associated protein 2 (MAP-2) in ipsilateral VPN of the thalamus at 1, 2 and 4 weeks after distal MCAO. Following ischemia, the expression of Nogo-A in oligodendrocytes increased persistently and its localization became redistributed around damaged axons and dendrites. Administration of NEP1-40 downregulated the expression of Nogo-A, reduced axonal injury and enhanced axonal regeneration. Our data suggest that Nogo-A is involved in secondary axonal degeneration and that inhibition of Nogo-A can reduce neuronal damage in the thalamus after distal MCAO.

Transcriptomic analysis of neuregulin-1 regulated genes following ischemic stroke by computational identification of promoter binding sites: A role for the ETS-1 transcription factor.

PubMed

Surles-Zeigler, Monique C; Li, Yonggang; Distel, Timothy J; Omotayo, Hakeem; Ge, Shaokui; Ford, Byron D

2018-01-01

Ischemic stroke is a major cause of mortality in the United States. We previously showed that neuregulin-1 (NRG1) was neuroprotective in rat models of ischemic stroke. We used gene expression profiling to understand the early cellular and molecular mechanisms of NRG1's effects after the induction of ischemia. Ischemic stroke was induced by middle cerebral artery occlusion (MCAO). Rats were allocated to 3 groups: (1) control, (2) MCAO and (3) MCAO + NRG1. Cortical brain tissues were collected three hours following MCAO and NRG1 treatment and subjected to microarray analysis. Data and statistical analyses were performed using R/Bioconductor platform alongside Genesis, Ingenuity Pathway Analysis and Enrichr software packages. There were 2693 genes differentially regulated following ischemia and NRG1 treatment. These genes were organized by expression patterns into clusters using a K-means clustering algorithm. We further analyzed genes in clusters where ischemia altered gene expression, which was reversed by NRG1 (clusters 4 and 10). NRG1, IRS1, OPA3, and POU6F1 were central linking (node) genes in cluster 4. Conserved Transcription Factor Binding Site Finder (CONFAC) identified ETS-1 as a potential transcriptional regulator of NRG1 suppressed genes following ischemia. A transcription factor activity array showed that ETS-1 activity was increased 2-fold, 3 hours following ischemia and this activity was attenuated by NRG1. These findings reveal key early transcriptional mechanisms associated with neuroprotection by NRG1 in the ischemic penumbra.

Evolution of ischemic damage and behavioural deficit over 6 months after MCAo in the rat: Selecting the optimal outcomes and statistical power for multi-centre preclinical trials

PubMed Central

Churilov, Leonid; Sidon, T. Kate; Aleksoska, Elena; Cox, Susan F.; Macleod, Malcolm R.; Howells, David W.

2017-01-01

Key disparities between the timing and methods of assessment in animal stroke studies and clinical trial may be part of the reason for the failure to translate promising findings. This study investigates the development of ischemic damage after thread occlusion MCAo in the rat, using histological and behavioural outcomes. Using the adhesive removal test we investigate the longevity of behavioural deficit after ischemic stroke in rats, and examine the practicality of using such measures as the primary outcome for future studies. Ischemic stroke was induced in 132 Spontaneously Hypertensive Rats which were assessed for behavioural and histological deficits at 1, 3, 7, 14, 21, 28 days, 12 and 24 weeks (n>11 per timepoint). The basic behavioural score confirmed induction of stroke, with deficits specific to stroke animals. Within 7 days, these deficits resolved in 50% of animals. The adhesive removal test revealed contralateral neglect for up to 6 months following stroke. Sample size calculations to facilitate the use of this test as the primary experimental outcome resulted in cohort sizes much larger than are the norm for experimental studies. Histological damage progressed from a necrotic infarct to a hypercellular area that cleared to leave a fluid filled cavity. Whilst absolute volume of damage changed over time, when corrected for changes in hemispheric volume, an equivalent area of damage was lost at all timepoints. Using behavioural measures at chronic timepoints presents significant challenges to the basic science community in terms of the large number of animals required and the practicalities associated with this. Multicentre preclinical randomised controlled trials as advocated by the MultiPART consortium may be the only practical way to deal with this issue. PMID:28182727

[Effect of ginsenoside Rb1 on cerebral infarction volume and IL-1 beta in the brain tissue and sera of focal cerebral ischemia/reperfusion injury model rats].

PubMed

Liu, Jun-Wei; Ren, Ye-Long; Liu, Xu-Ling; Xia, Hong-Lian; Zhang, Hui-Ling; Jin, Shen-Hui; Dai, Qin-Xue; Wang, Jun-Lu

2013-12-01

To investigate the effect of ginsenoside Rb1 on cerebral infarction volume as well as IL-1 beta in the brain tissue and sera of focal cerebral ischemia/reperfusion (I/R) injury model rats. The I/R rat model was established by using thread according to Zea-Longa. SD rats were randomly divided into five groups, i.e., the sham-operation group, the model group, the low dose ginsenoside Rb1 (20 mg/kg) group, the medium dose ginsenoside Rb1 group (40 mg/kg), and the high dose ginsenoside Rb1 group (80 mg/kg), 12 in each group. Rats in the sham-operation group only received middle cerebral artery occlusion (MCAO) but without thread insertion. The MCAO model was prepared in the rest 4 groups, followed by MCAO2 h later. Ginsenoside Rb1 at each dose was peritoneally administrated to rats in corresponding groups immediately after cerebral ischemia. Equal volume of normal saline was administered to rats in the sham-operation group. Rats' cerebral infarction volume, integrals of neurologic defect degree, expression of IL-1 beta content in the brain tissue and sera were observed 24 h after 2-h cerebral I/R. In the model group, integrals of neurologic defect degree were improved (P < 0.01), IL-1 beta positive cells in the brain tissue increased and serum IL-1 beta content elevated (P < 0.05), when compared with the sham-operation group. In comparison of the model group, integrals of neurologic defect degree were lowered in the medium dose and high dose ginsenoside Rb1 groups (P < 0.05, P < 0.01). The cerebral infarction volume was all shrunken in each ginsenoside Rb1 group, IL-1 beta positive cells in the brain tissue decreased, and IL-1 beta content in serum reduced (P < 0.01, P < 0.05). Compared with the low dose ginsenoside Rb1 group, integrals of neurologic defect degree decreased, the cerebral infarction volume shrunken, and IL-1 beta content in serum reduced in the high dose ginsenoside Rb1 group (P < 0.01, P < 0.05). Ginsenoside Rb1 (20, 40, 80 mg/kg) might effectively

Combined use of rapid-prototyping model and surgical guide in correction of mandibular asymmetry malformation patients with normal occlusal relationship.

PubMed

Xu, Haisong; Zhang, Ce; Shim, Yoong Hoon; Li, Hongliang; Cao, Dejun

2015-03-01

The aim of this study is to discuss the application of rapid-prototyping model and surgical guide in the treatment of mandibular asymmetry malformation with normal occlusal relationship. Twenty-four mandibular asymmetry malformation patients with relatively normal occlusal relationship were included in this study. Surgical 3-dimensional rapid-prototyping mandibular models were made for all patients from the computed tomography (CT) DICOM data. The presurgical plan was designed on the model, and the surgical guiders for the osteotomy lines were manufactured. Genioplasty and/or mandibular osteotomy based on the presurgical plan were performed on these patients with the combined use of the rapid-prototyping model and surgical guides. All patients underwent postoperative CT scan and had at least 3-month follow-up. All patients were satisfied with the final results. According to the postoperative CT images and 3-month follow-up, all patients' mandibular asymmetry malformation was significantly improved, and the operation time was distinctly shortened relative to the conventional method. Rapid-prototyping model and surgical guide are viable auxiliary devices for the treatment of mandibular asymmetry malformation with relatively normal occlusal relationship. Combined use of them can make precise preoperative design, improve effects of operation, and shorten operating time.

Study of the occlusion effect induced by an earplug: Numerical modelling and experimental validation

NASA Astrophysics Data System (ADS)

Brummund, Martin

(IRSST) and the Ecole de technologie superieure (ETS) has been launched. The present study represents a part of this collaboration and aims at studying the occlusion effect of the system earplug - ear canal through the development of novel numerical models and experimental methods. (Abstract shortened by UMI.).

SO2 inhalation contributes to the development and progression of ischemic stroke in the brain.

PubMed

Sang, Nan; Yun, Yang; Li, Hongyan; Hou, Li; Han, Ming; Li, Guangke

2010-04-01

Epidemiological literatures show an association between air pollution and ischemic stroke, and effective pollutants may include SO(2), NO(x), O(3), CO, and particulates. However, existing experimental studies lack evidence as to the presence of effects for SO(2), which has been the focus in developing countries with increasing use of coal as the main resource. In the present study, we treated Wistar rats with SO(2) at various concentrations and determined endothelin-1 (ET-1), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and intercellular adhesion molecule 1 (ICAM-1) messenger RNA (mRNA) and protein expression in the cortex. The results show that SO(2) elevated the levels of ET-1, iNOS, COX-2, and ICAM-1 mRNA and protein in a concentration-dependent manner. Then, we set up rat model of ischemic stroke using middle cerebral artery occlusion (MCAO) and further treated the model rats with filtered air and lower concentration SO(2) for the same period. As expected, elevated expression of ET-1, iNOS, COX-2, and ICAM-1 occurred in the cortex of MCAO model rats exposed to filtered air, followed by increased activation of caspase-3 and cerebral infarct volume. Interestingly, SO(2) inhalation after MCAO significantly amplified above effects. It implies that SO(2) inhalation caused brain injuries similar to that of cerebral ischemia, and its exposure in atmospheric environment contributed to the development and progression of ischemic stroke.

Contralateral Occlusion Test: The effect of external ear canal occlusion on hearing thresholds.

PubMed

Reis, Luis Roque; Fernandes, Paulo; Escada, Pedro

Bedside testing with tuning forks may decrease turnaround time and improve decision making for a quick qualitative assessment of hearing loss. The purpose of this study was to quantify the effects of ear canal occlusion on hearing, in order to decide which tuning fork frequency is more appropriate to use for quantifying hearing loss with the Contralateral Occlusion Test. Twenty normal-hearing adults (forty ears) underwent sound field pure tone audiometry with and without ear canal occlusion. Each ear was tested with the standard frequencies. The contralateral ear was suppressed with by masking. Ear occlusion was performed by two examiners. Participants aged between 21 and 30 years (25.6±3.03 years) showed an increase in hearing thresholds with increasing frequencies from 19.94dB (250Hz) to 39.25dB (2000Hz). The threshold difference between occluded and unoccluded conditions was statistically significant and increased from 10.69dB (250Hz) to 32.12dB (2000Hz). There were no statistically significant differences according to gender or between the examiners. The occlusion effect increased the hearing thresholds and became more evident with higher frequencies. The occlusion method as performed demonstrated reproducibility. In the Contralateral Occlusion Test, 256Hz or 512Hz tuning forks should be used for diagnosis of mild hearing loss, and a 2048Hz tuning fork should be used for moderate hearing loss. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. All rights reserved.

Compliance with occlusion therapy for childhood amblyopia.

PubMed

Wallace, Michael P; Stewart, Catherine E; Moseley, Merrick J; Stephens, David A; Fielder, Alistair R

2013-09-17

Explore compliance with occlusion treatment of amblyopia in the Monitored and Randomized Occlusion Treatment of Amblyopia Studies (MOTAS and ROTAS), using objective monitoring. Both studies had a three-phase protocol: initial assessment, refractive adaptation, and occlusion. In the occlusion phase, participants were instructed to dose for 6 hours/day (MOTAS) or randomized to 6 or 12 hour/day (ROTAS). Dose was monitored continuously using an occlusion dose monitor (ODM). One hundred and fifty-two patients (71 male, 81 female; 122 Caucasian, 30 non-Caucasian) of mean ± SD age 68 ± 18 months participated. Amblyopia was defined as an interocular acuity difference of at least 0.1 logMAR and was associated with anisometropia in 50, strabismus in 44, and both (mixed) in 58. Median duration of occlusion was 99 days (interquartile range 72 days). Mean compliance was 44%, mean proportion of days with no patch worn was 42%. Compliance was lower (39%) on weekends compared with weekdays (46%, P = 0.04), as was the likelihood of dosing at all (52% vs. 60%, P = 0.028). Compliance was lower when attendance was less frequent (P < 0.001) and with prolonged treatment duration (P < 0.001). Age, sex, amblyopia type, and severity were not associated with compliance. Mixture modeling suggested three subpopulations of patch day doses: less than 30 minutes; doses that achieve 30% to 80% compliance; and doses that achieve around 100% compliance. This study shows that compliance with patching treatment averages less than 50% and is influenced by several factors. A greater understanding of these influences should improve treatment outcome. (ClinicalTrials.gov number, NCT00274664).

Neuroprotection of early and short-time applying berberine in the acute phase of cerebral ischemia: up-regulated pAkt, pGSK and pCREB, down-regulated NF-κB expression, ameliorated BBB permeability.

PubMed

Zhang, Xiaolin; Zhang, Xiangjian; Wang, Chaohui; Li, Yanhua; Dong, Lipeng; Cui, Lili; Wang, Lina; Liu, Zongjie; Qiao, Huimin; Zhu, Chunhua; Xing, Yinxue; Cao, Xiaoyun; Ji, Ye; Zhao, Kang

2012-06-12

Berberine (BBR) has gained attention for its vast beneficial biological effects through immunomodulation, anti-inflammatory and anti-apoptosis properties. Inflammatory and apoptosis damage play an important role in cerebral ischemic pathogenesis and may represent a target for treatment. The aim of this study was to explore BBR's effect in ischemic injury and the role of the Akt/GSK (glycogen synthase kinase) signaling cascade in mediating the anti-apoptosis and anti-inflammatory effects in the rat brain of permanent middle cerebral artery occlusion (pMCAO). Male Sprague-Dawley rats were subjected to pMCAO and randomly assigned into four groups: Sham (sham-operated) group, pMCAO (pMCAO+0.9% saline) group, BBR-L (pMCAO+BBR 10 mg/kg) and BBR-H (pMCAO+BBR 40 mg/kg) group. BBR was administered immediately after pMCAO and the neuroprotection was detected. Phospho-Akt (pAkt), phospho-glycogen synthase kinase 3-β (pGSK3β), phospho-cAMP response element binding protein (pCREB), nuclear factor-kappa B (NF-κB) and claudin-5 in ischemic cerebral cortex were detected by immunohistochemistry, reverse transcription-polymerase chain reaction and western blotting. Compared with pMCAO group, BBR dramatically lessened neurological deficits scores, brain water contents and infarct sizes, upregulated the expression of pAkt, pGSK3β, pCREB and claudin-5, and decreased the nuclear accumulation of NF-κB (P<0.05) in ischemic brain. The results showed that BBR reduced ischemic brain injury after pMACO, and this effect may be via the increasing the activation of Akt/GSK signaling and claudin-5, and decreasing NF-κB expression. Copyright © 2012 Elsevier B.V. All rights reserved.

Inhibition of Aquaporin-4 Improves the Outcome of Ischaemic Stroke and Modulates Brain Paravascular Drainage Pathways.

PubMed

Pirici, Ionica; Balsanu, Tudor Adrian; Bogdan, Catalin; Margaritescu, Claudiu; Divan, Tamir; Vitalie, Vacaras; Mogoanta, Laurentiu; Pirici, Daniel; Carare, Roxana Octavia; Muresanu, Dafin Fior

2017-12-23

Aquaporin-4 (AQP4) is the most abundant water channel in the brain, and its inhibition before inducing focal ischemia, using the AQP4 inhibitor TGN-020, has been showed to reduce oedema in imaging studies. Here, we aimed to evaluate, for the first time, the histopathological effects of a single dose of TGN-020 administered after the occlusion of the medial cerebral artery (MCAO). On a rat model of non-reperfusion ischemia, we have assessed vascular densities, albumin extravasation, gliosis, and apoptosis at 3 and 7 days after MCAO. TGN-020 significantly reduced oedema, glial scar, albumin effusion, and apoptosis, at both 3 and 7 days after MCAO. The area of GFAP-positive gliotic rim decreased, and 3D fractal analysis of astrocytic processes revealed a less complex architecture, possibly indicating water accumulating in the cytoplasm. Evaluation of the blood vessels revealed thicker basement membranes colocalizing with exudated albumin in the treated animals, suggesting that inhibition of AQP4 blocks fluid flow towards the parenchyma in the paravascular drainage pathways of the interstitial fluid. These findings suggest that a single dose of an AQP4 inhibitor can reduce brain oedema, even if administered after the onset of ischemia, and AQP4 agonists/antagonists might be effective modulators of the paravascular drainage flow.

Misoprostol, an anti-ulcer agent and PGE2 receptor agonist, protects against cerebral ischemia.

PubMed

Li, Jun; Liang, Xibin; Wang, Qian; Breyer, Richard M; McCullough, Louise; Andreasson, Katrin

2008-06-20

Induction of COX-2 activity in cerebral ischemia results in increased neuronal injury and infarct size. Recent studies investigating neurotoxic mechanisms of COX-2 demonstrate both toxic and paradoxically protective effects of downstream prostaglandin receptor signaling pathways. We tested whether misoprostol, a PGE(2) receptor agonist that is utilized clinically as an anti-ulcer agent and signals through the protective PGE(2) EP2, EP3, and EP4 receptors, would reduce brain injury in the murine middle cerebral artery occlusion-reperfusion (MCAO-RP) model. Administration of misoprostol, at the time of MCAO or 2h after MCAO, resulted in significant rescue of infarct volume at 24 and 72h. Immunocytochemistry demonstrated dynamic regulation of the EP2 and EP4 receptors during reperfusion in neurons and endothelial cells of cerebral cortex and striatum, with limited expression of EP3 receptor. EP3-/- mice had no significant changes in infarct volume compared to control littermates. Moreover, administration of misoprostol to EP3+/+ and EP3-/- mice showed similar levels of infarct rescue, indicating that misoprostol protection was not mediated through the EP3 receptor. Taken together, these findings suggest a novel function for misoprostol as a protective agent in cerebral ischemia acting via the PGE(2) EP2 and/or EP4 receptors.

Memantine attenuates cell apoptosis by suppressing the calpain-caspase-3 pathway in an experimental model of ischemic stroke.

PubMed

Chen, Bin; Wang, Guoxiang; Li, Weiwei; Liu, Weilin; Lin, Ruhui; Tao, Jing; Jiang, Min; Chen, Lidian; Wang, Yun

2017-02-15

Ischemic stroke, the second leading cause of death worldwide, leads to excessive glutamate release, over-activation of N-methyl-D-aspartate receptor (NMDAR), and massive influx of calcium (Ca 2+ ), which may activate calpain and caspase-3, resulting in cellular damage and death. Memantine is an uncompetitive NMDAR antagonist with low-affinity/fast off-rate. We investigated the potential mechanisms through which memantine protects against ischemic stroke in vitro and in vivo. Middle cerebral artery occlusion-reperfusion (MCAO) was performed to establish an experimental model of ischemic stroke. The neuroprotective effects of memantine on ischemic rats were evaluated by neurological deficit scores and infarct volumes. The activities of calpain and caspase-3, and expression levels of microtubule-associated protein-2 (MAP2) and postsynaptic density-95 (PSD95) were determined by Western blotting. Additionally, Nissl staining and immunostaining were performed to examine brain damage, cell apoptosis, and neuronal loss induced by ischemia. Our results show that memantine could significantly prevent ischemic stroke-induced neurological deficits and brain infarct, and reduce ATP depletion-induced neuronal death. Moreover, memantine markedly suppressed the activation of the calpain-caspase-3 pathway and cell apoptosis, and consequently, attenuated brain damage and neuronal loss in MCAO rats. These results provide a molecular basis for the role of memantine in reducing neuronal apoptosis and preventing neuronal damage, suggesting that memantine may be a promising therapy for stroke patients. Copyright © 2017 Elsevier Inc. All rights reserved.

[Effect of 2 methods of occlusion adjustment on occlusal balance and muscles of mastication in patient with implant restoration].

PubMed

Wang, Rong; Xu, Xin

2015-12-01

To compare the effect of 2 methods of occlusion adjustment on occlusal balance and muscles of mastication in patients with dental implant restoration. Twenty patients, each with a single edentulous posterior dentition with no distal dentition were selected, and divided into 2 groups. Patients in group A underwent original occlusion adjustment method and patients in group B underwent occlusal plane reduction technique. Ankylos implants were implanted in the edentulous space in each patient and restored with fixed prosthodontics single unit crown. Occlusion was adjusted in each restoration accordingly. Electromyograms were conducted to determine the effect of adjustment methods on occlusion and muscles of mastication 3 months and 6 months after initial restoration and adjustment. Data was collected and measurements for balanced occlusal measuring standards were obtained, including central occlusion force (COF), asymmetry index of molar occlusal force(AMOF). Balanced muscles of mastication measuring standards were also obtained including measurements from electromyogram for the muscles of mastication and the anterior bundle of the temporalis muscle at the mandibular rest position, average electromyogram measurements of the anterior bundle of the temporalis muscle at the intercuspal position(ICP), Astot, masseter muscle asymmetry index, and anterior temporalis asymmetry index (ASTA). Statistical analysis was performed using Student 's t test with SPSS 18.0 software package. Three months after occlusion adjustment, parameters of the original occlusion adjustment method were significantly different between group A and group B in balanced occlusal measuring standards and balanced muscles of mastication measuring standards. Six months after occlusion adjustment, parameters of the original occlusion adjustment methods were significantly different between group A and group B in balanced muscles of mastication measuring standards, but was no significant difference in balanced

Accurate landmarking of three-dimensional facial data in the presence of facial expressions and occlusions using a three-dimensional statistical facial feature model.

PubMed

Zhao, Xi; Dellandréa, Emmanuel; Chen, Liming; Kakadiaris, Ioannis A

2011-10-01

Three-dimensional face landmarking aims at automatically localizing facial landmarks and has a wide range of applications (e.g., face recognition, face tracking, and facial expression analysis). Existing methods assume neutral facial expressions and unoccluded faces. In this paper, we propose a general learning-based framework for reliable landmark localization on 3-D facial data under challenging conditions (i.e., facial expressions and occlusions). Our approach relies on a statistical model, called 3-D statistical facial feature model, which learns both the global variations in configurational relationships between landmarks and the local variations of texture and geometry around each landmark. Based on this model, we further propose an occlusion classifier and a fitting algorithm. Results from experiments on three publicly available 3-D face databases (FRGC, BU-3-DFE, and Bosphorus) demonstrate the effectiveness of our approach, in terms of landmarking accuracy and robustness, in the presence of expressions and occlusions.

TOWARD PRECISION PHOTOMETRY FOR THE ELT ERA: THE DOUBLE SUBGIANT BRANCH OF NGC 1851 OBSERVED WITH THE GEMINI/GeMS MCAO SYSTEM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turri, P.; McConnachie, A. W.; Stetson, P. B.

2015-10-01

The Extremely Large Telescopes currently under construction have a collecting area that is an order of magnitude larger than the present largest optical telescopes. For seeing-limited observations the performance will scale as the collecting area, but with the successful use of adaptive optics (AO), for many applications it will scale as D{sup 4} (where D is the diameter of the primary mirror). Central to the success of the ELTs, therefore, is the successful use of multi-conjugate adaptive optics (MCAO) which applies a high degree of correction over a field of view larger than the few arcseconds that limits classical AOmore » systems. In this Letter, we report on the analysis of crowded field images taken on the central region of the galactic globular cluster NGC 1851 in the K{sub s} band using the Gemini Multi-conjugate Adaptive Optics System (GeMS) at the Gemini South Telescope, the only science-grade MCAO system in operation. We use this cluster as a benchmark to verify the ability to achieve precise near-infrared photometry by presenting the deepest K{sub s} photometry in crowded fields ever obtained from the ground. We construct a color–magnitude diagram in combination with the F606W band from the Hubble Space Telescope/Advanced Camera for Surveys. As well as detecting the “knee” in the lower main sequence at K{sub s} ≃ 20.5, we also detect the double subgiant branch of NGC 1851, which demonstrates the high photometric accuracy of GeMS in crowded fields.« less

Discriminative correlation filter tracking with occlusion detection

NASA Astrophysics Data System (ADS)

Zhang, Shuo; Chen, Zhong; Yu, XiPeng; Zhang, Ting; He, Jing

2018-03-01

Aiming at the problem that the correlation filter-based tracking algorithm can not track the target of severe occlusion, a target re-detection mechanism is proposed. First of all, based on the ECO, we propose the multi-peak detection model and the response value to distinguish the occlusion and deformation in the target tracking, which improve the success rate of tracking. And then we add the confidence model to update the mechanism to effectively prevent the model offset problem which due to similar targets or background during the tracking process. Finally, the redetection mechanism of the target is added, and the relocation is performed after the target is lost, which increases the accuracy of the target positioning. The experimental results demonstrate that the proposed tracker performs favorably against state-of-the-art methods in terms of robustness and accuracy.

Acute stroke with major intracranial vessel occlusion: Characteristics of cardioembolism and atherosclerosis-related in situ stenosis/occlusion.

PubMed

Horie, Nobutaka; Tateishi, Yohei; Morikawa, Minoru; Morofuji, Yoichi; Hayashi, Kentaro; Izumo, Tsuyoshi; Tsujino, Akira; Nagata, Izumi; Matsuo, Takayuki

2016-10-01

Acute ischemic stroke with major intracranial vessel occlusion is commonly due to cardioembolic or atherosclerosis-related in situ stenosis/occlusion, and immediate identification of these subtypes is important to establish the optimal treatment strategy. The aim of this study was to clarify the differences in clinical presentation, radiological findings, neurological temporal courses, and outcomes between these etiologies, which have not been fully evaluated. Consecutive emergency patients with acute ischemic stroke were retrospectively reviewed. Among them, patients with stroke with major intracranial vessel occlusion were analyzed with a focus on clinical and radiological findings, and a comparison was performed for those with cardioembolic or atherosclerosis-related in situ stenosis/occlusion. Of 1053 patients, 80 had stroke with acute major intracranial vessel occlusion (45 with cardioembolic and 35 with atherosclerosis-related in situ stenosis/occlusion). Interestingly, the susceptibility vessel sign (SVS) on T2-weighted MR angiography was more frequently detected in cardioembolic stroke (80.0%) than in atherosclerosis (in situ stenosis: 5.9%, chronic occlusion: 14.3%). Moreover, the proximal intra-arterial signal (IAS) on arterial spin labeling MRI and the distal IAS on fluid attenuated inversion recovery MRI was less frequently detected in chronic occlusion (27.3% and 50.0%, respectively) than in acute occlusion due to cardioembolic or in situ stenosis. Multivariate regression analysis showed that the SVS was significantly related to cardioembolism (adjusted odds ratio (OR): 21.68, P=0.004). Clinical characteristics of acute stroke with major intracranial vessel occlusion differ depending on the etiology. The SVS and proximal/distal IAS on MRI are useful to distinguish between cardioembolic and atherosclerotic-related in situ stenosis/occlusion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Recurrence of amblyopia after occlusion therapy.

PubMed

Bhola, Rahul; Keech, Ronald V; Kutschke, Pamela; Pfeifer, Wanda; Scott, William E

2006-11-01

To determine the stability of visual acuity (VA) after a standardized occlusion regimen in children with strabismic and/or anisometropic amblyopia. Retrospective, population-based, consecutive observational case series. Four hundred forty-nine patients younger than 10 years who underwent an occlusion trial for amblyopia and were observed until there was a recurrence of amblyopia or for a maximum of 1 year after decrease or cessation of occlusion therapy. We performed a retrospective chart review of all patients treated by occlusion therapy for strabismic and/or anisometropic amblyopia at our institution over a 34-year period. Of the 1621 patients identified in our database, 449 met the eligibility criteria and were included in this study. Patients having at least a 2 logarithm of the minimum angle of resolution (logMAR)-level improvement in VA by optotypes or a change from unmaintained to maintained fixation preference during the course of occlusion therapy were included. A recurrence of amblyopia was defined as > or =2 logMAR levels of VA reduction or reversal of fixation preference within 1 year after a decrease or cessation of occlusion therapy. Recurrence of amblyopia after a decrease or cessation of occlusion therapy and its relationship with patient age and VA of the amblyopic eye at the time of decrease or cessation of occlusion therapy. Of 653 occlusion trials, 179 (27%) resulted in recurrence of amblyopia. The recurrence was found to be inversely correlated with patient age. There was no statistically significant association between the recurrence of amblyopia and VA of the amblyopic eye at the end of maximal occlusion therapy. There is a clinically important risk of amblyopia recurrence when occlusion therapy is decreased before the age of 10 years. The risk of recurrence is inversely correlated with age (P<0.0001).

The Role of Glutamate Release on Voltage-Dependent Anion Channels (VDAC)-Mediated Apoptosis in an Eleven Vessel Occlusion Model in Rats

PubMed Central

Park, Eunkuk; Lee, Gi-Ja; Choi, Samjin; Choi, Seok-Keun; Chae, Su-Jin; Kang, Sung-Wook; Pak, Youngmi Kim; Park, Hun-Kuk

2010-01-01

Voltage-dependent anion channel (VDAC) is the main protein in mitochondria-mediated apoptosis, and the modulation of VDAC may be induced by the excessive release of extracellular glutamate. This study examined the role of glutamate release on VDAC-mediated apoptosis in an eleven vessel occlusion model in rats. Male Sprague-Dawley rats (250–350 g) were used for the 11 vessel occlusion ischemic model, which were induced for a 10-min transient occlusion. During the ischemic and initial reperfusion episode, the real-time monitoring of the extracellular glutamate concentration was measured using an amperometric microdialysis biosensor and the cerebral blood flow (CBF) was monitored by laser-Doppler flowmetry. To confirm neuronal apoptosis, the brains were removed 72 h after ischemia to detect the neuron-specific nuclear protein and pro-apoptotic proteins (cleaved caspase-3, VDAC, p53 and BAX). The changes in the mitochondrial morphology were measured by atomic force microscopy. A decrease in the % of CBF was observed, and an increase in glutamate release was detected after the onset of ischemia, which continued to increase during the ischemic period. A significantly higher level of glutamate release was observed in the ischemia group. The increased glutamate levels in the ischemia group resulted in the activation of VDAC and pro-apoptotic proteins in the hippocampus with morphological alterations to the mitochondria. This study suggests that an increase in glutamate release promotes VDAC-mediated apoptosis in an 11 vessel occlusion ischemic model. PMID:21203570

Anesthesia-Induced Hypothermia Attenuates Early-Phase Blood-Brain Barrier Disruption but Not Infarct Volume following Cerebral Ischemia.

PubMed

Liu, Yu-Cheng; Lee, Yu-Da; Wang, Hwai-Lee; Liao, Kate Hsiurong; Chen, Kuen-Bao; Poon, Kin-Shing; Pan, Yu-Ling; Lai, Ted Weita

2017-01-01

Blood-brain barrier (BBB) disruption is thought to facilitate the development of cerebral infarction after a stroke. In a typical stroke model (such as the one used in this study), the early phase of BBB disruption reaches a peak 6 h post-ischemia and largely recovers after 8-24 h, whereas the late phase of BBB disruption begins 48-58 h post-ischemia. Because cerebral infarct develops within 24 h after the onset of ischemia, and several therapeutic agents have been shown to reduce the infarct volume when administered at 6 h post-ischemia, we hypothesized that attenuating BBB disruption at its peak (6 h post-ischemia) can also decrease the infarct volume measured at 24 h. We used a mouse stroke model obtained by combining 120 min of distal middle cerebral arterial occlusion (dMCAo) with ipsilateral common carotid arterial occlusion (CCAo). This model produced the most reliable BBB disruption and cerebral infarction compared to other models characterized by a shorter duration of ischemia or obtained with dMCAO or CCAo alone. The BBB permeability was measured by quantifying Evans blue dye (EBD) extravasation, as this tracer has been shown to be more sensitive for the detection of early-phase BBB disruption compared to other intravascular tracers that are more appropriate for detecting late-phase BBB disruption. We showed that a 1 h-long treatment with isoflurane-anesthesia induced marked hypothermia and attenuated the peak of BBB disruption when administered 6 h after the onset of dMCAo/CCAo-induced ischemia. We also demonstrated that the inhibitory effect of isoflurane was hypothermia-dependent because the same treatment had no effect on ischemic BBB disruption when the mouse body temperature was maintained at 37°C. Importantly, inhibiting the peak of BBB disruption by hypothermia had no effect on the volume of brain infarct 24 h post-ischemia. In conclusion, inhibiting the peak of BBB disruption is not an effective neuroprotective strategy, especially in comparison

[Clinical evaluation of preadjusted appliance based on Chinese normal occlusion].

PubMed

Chen, Lin; Gao, Xue-Mei; Zeng, Xiang-Long

2008-02-01

To evaluate the effect of the preadjusted appliance (Z1 appliance) based on Chinese normal occlusion. Thirty non-extraction patients were treated with Z1 appliance. No wire bending was made during treatment. The results of these 30 cases had been evaluated by five senior orthodontists. Models were analysed quantitatively to testify and evaluate the efficiency of the appliance. The average score for post-treatment models was 91.2 (total score was 100). The model measurements indicated that average projective distance on occlusal plane between proximal contact points of adjacent teeth was less than 0.3 mm, which demonstrated good alignment. The prominence of crowns was almost coincident with the data of Chinese normal occlusion. For the average tip of most teeth, there was no statistical difference between the study group and the normal control group. The crown torque variation tendency from anterior to posterior was similar to that in the subjects with normal occlusion. However, the cases treated with Z1 appliance achieved more negative torque in the lower posterior segment. The result of the non-extraction patients treated with Z1 appliance was quite satisfied. Wire bending could be reduced during treatment. It was necessary to adjust the crown torque values for lower posterior teeth.

Long-term occlusal changes assessed by the American Board of Orthodontics' model grading system.

PubMed

Aszkler, Robert M; Preston, Charles B; Saltaji, Humam; Tabbaa, Sawsan

2014-02-01

The purpose of this study was to assess the long-term posttreatment changes in all criteria of the American Board of Orthodontics' (ABO) model grading system. We used plaster models from patients' final and posttreatment records. Thirty patients treated by 1 orthodontist using 1 bracket prescription were selected. An initial discrepancy index for each subject was performed to determine the complexity of each case. The final models were then graded using the ABO's model grading system immediately at posttreatment and postretention. Statistical analysis was performed on the 8 criteria of the model grading system, including paired t tests and Pearson correlations. An alpha of 0.05 was considered statistically significant. The average length of time between the posttreatment and postretention records was 12.7 ± 4.4 years. It was shown that alignment and rotations worsened by postretention (P = 0.014), and a weak statistically significant correlation at posttreatment and postretention was found (0.44; P = 0.016). Both marginal ridges and occlusal contacts scored less well at posttreatment. These criteria showed a significant decrease in scores between posttreatment and postretention (P <0.001), but the correlations were not statistically significant. The average total score showed a significant decrease between posttreatment and postretention (P <0.001), partly because of the large decrease in the previous 2 criteria. Higher scores for occlusal contacts and marginal ridges were found at the end of treatment; however, those scores and the overall scores for the 30 subjects improved in the postretention phase. Copyright © 2014. Published by Mosby, Inc.

Effect of ligustrazine on levels of amino acid neurotransmitters in rat striatum after cerebral ischemia-reperfusion injury.

PubMed

Han, Jin; Wan, Hai-Tong; Yang, Jie-Hong; Zhang, Yu-Yan; Ge, Li-Jun; Bie, Xiao-Dong

2014-01-01

This study aimed to evaluate the effect of ligustrazine on levels of amino acid transmitters in the extracellular fluid of striatum following cerebral ischemia/reperfusion (I/R) in male Sprague-Dawley rats. A microdialysis cannula guide was implanted into the right striatum. After recovery, animals underwent a sham operation or middle cerebral artery occlusion (MCAO). Those that developed cerebral ischemia after MCAO were randomized to receive propylene glycol salt water and ligustrazine respectively. Striatal fluid samples were collected from all animals at 15-min intervals after treatment and were subjected to HPLC analysis of aspartic acid, glutamic acid, taurine, and γ-amino butyric acid. Upon the last sample collection, animals were sacrificed and brain tissue specimens were collected for triphenyltetrazolium chloride staining and NeuN staining. Compared with the sham operation, MCAO induced significant neurological deficits and increased striatal concentrations of the four neurotransmitters assessed in a time-dependent manner (P < 0.01). Ligustrazine effectively attenuated the detrimental effects of MCAO on the brain. These observations suggest that ligustrazine as a novel cerebral infarction-protective agent may have potential clinical implications for I/R-related brain damage.

Delayed brain ischemia tolerance induced by electroacupuncture pretreatment is mediated via MCP-induced protein 1

PubMed Central

2013-01-01

Background Emerging studies have demonstrated that pretreatment with electroacupuncture (EA) induces significant tolerance to focal cerebral ischemia. The present study seeks to determine the involvement of monocyte chemotactic protein-induced protein 1 (MCPIP1), a recently identified novel modulator of inflammatory reactions, in the cerebral neuroprotection conferred by EA pretreatment in the animal model of focal cerebral ischemia and to elucidate the mechanisms of EA pretreatment-induced ischemic brain tolerance. Methods Twenty-four hours after the end of the last EA pretreatment, focal cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) for 90 minutes in male C57BL/6 mice and MCPIP1 knockout mice. Transcription and expression of MCPIP1 gene was monitored by qRT-PCR, Western blot and immunohistochemistry. The neurobehavioral scores, infarction volumes, proinflammatory cytokines and leukocyte infiltration in brain and NF-κB signaling were evaluated after ischemia/reperfusion. Results MCPIP1 protein and mRNA levels significantly increased specifically in mouse brain undergoing EA pretreatment. EA pretreatment significantly attenuated the infarct volume, neurological deficits, upregulation of proinflammatory cytokines and leukocyte infiltration in the brain of wild-type mice after MCAO compared with that of the non-EA group. MCPIP1-deficient mice failed to evoke EA pretreatment-induced tolerance compared with that of the control MCPIP1 knockout group without EA treatment. Furthermore, the activation of NF-κB signaling was significantly reduced in EA-pretreated wild-type mice after MCAO compared to that of the non-EA control group and MCPIP1-deficient mice failed to confer the EA pretreatment-induced inhibition of NF-κB signaling after MCAO. Conclusions Our data demonstrated that MCPIP1 deficiency caused significant lack of EA pretreatment-induced cerebral protective effects after MCAO compared with the control group and that MCPIP1 is

Combined metabolic and transcriptional profiling identifies pentose phosphate pathway activation by HSP27 phosphorylation during cerebral ischemia.

PubMed

Imahori, Taichiro; Hosoda, Kohkichi; Nakai, Tomoaki; Yamamoto, Yusuke; Irino, Yasuhiro; Shinohara, Masakazu; Sato, Naoko; Sasayama, Takashi; Tanaka, Kazuhiro; Nagashima, Hiroaki; Kohta, Masaaki; Kohmura, Eiji

2017-05-04

The metabolic pathophysiology underlying ischemic stroke remains poorly understood. To gain insight into these mechanisms, we performed a comparative metabolic and transcriptional analysis of the effects of cerebral ischemia on the metabolism of the cerebral cortex using middle cerebral artery occlusion (MCAO) rat model. Metabolic profiling by gas-chromatography/mass-spectrometry analysis showed clear separation between the ischemia and control group. The decreases of fructose 6-phosphate and ribulose 5-phosphate suggested enhancement of the pentose phosphate pathway (PPP) during cerebral ischemia (120-min MCAO) without reperfusion. Transcriptional profiling by microarray hybridization indicated that the Toll-like receptor and mitogen-activated protein kinase (MAPK) signaling pathways were upregulated during cerebral ischemia without reperfusion. In relation to the PPP, upregulation of heat shock protein 27 (HSP27) was observed in the MAPK signaling pathway and was confirmed through real-time polymerase chain reaction. Immunoblotting showed a slight increase in HSP27 protein expression and a marked increase in HSP27 phosphorylation at serine 85 after 60-min and 120-min MCAO without reperfusion. Corresponding upregulation of glucose 6-phosphate dehydrogenase (G6PD) activity and an increase in the NADPH/NAD + ratio were also observed after 120-min MCAO. Furthermore, intracerebroventricular injection of ataxia telangiectasia mutated (ATM) kinase inhibitor (KU-55933) significantly reduced HSP27 phosphorylation and G6PD upregulation after MCAO, but that of protein kinase D inhibitor (CID755673) did not affect HSP27 phosphorylation. Consequently, G6PD activation via ischemia-induced HSP27 phosphorylation by ATM kinase may be part of an endogenous antioxidant defense neuroprotection mechanism during the earliest stages of ischemia. These findings have important therapeutic implications for the treatment of stroke. Copyright © 2017 IBRO. Published by Elsevier Ltd. All

Neuropilin 2 deficiency does not affect cortical neuronal viability in response to oxygen-glucose-deprivation and transient middle cerebral artery occlusion.

PubMed

Hou, Sheng T; Jiang, Susan X; Slinn, Jacqueline; O'Hare, Michael; Karchewski, Laurie

2010-04-01

Neuropilin 2 (NRP2) is a type I transmembrane protein that binds to distinct members of the class III secreted Semaphorin subfamily. NRP2 plays important roles in repulsive axon guidance, angiogenesis and vasculogenesis through partnering with co-receptors such as vascular endothelial growth factor receptors (VEGFRs) during development. Emerging evidence also suggests that NRP2 contributes to injury response and environment changes in adult brains. In this study, we examined the contribution of NRP2 gene to cerebral ischemia-induced brain injury using NRP2 deficient mouse. To our surprise, the lack of NRP2 expression does not affect the outcome of brain injury induced by transient occlusion of the middle cerebral artery (MCAO) in mouse. The cerebral vasculature in terms of the middle cerebral artery anatomy and microvessel density in the cerebral cortex of NRP2 deficient homozygous (NRP2(-/-)) mice are normal and almost identical to those of the heterozygous (NRP2(+/-)) and wild type (NRP2(+/+)) littermates. MCAO (1h) and 24h reperfusion caused a brain infarction of 23% (compared to the contralateral side) in NRP2(-/-) mice, which is not different from those in NRP2(+/- and +/+) mice at 22 and 21%, respectively (n=19, p>0.05). Correspondingly, NRP2(-/-) mouse also showed a similar level of deterioration of neurological functions after stroke compared with their NRP2(+/- and +/+) littermates. Oxygen-glucose-deprivation (OGD) caused a significant neuronal death in NRP2(-/-) cortical neurons, at the level similar to that in NRP(+/+) cortical neurons (72% death in NRP(-/-) neurons vs. 75% death in NRP2(+/+) neurons; n=4; p>0.05). Together, these loss-of-function studies demonstrated that despite of its critical role in neuronal guidance and vascular formation during development, NRP2 expression dose not affect adult brain response to cerebral ischemia. Crown Copyright 2009. Published by Elsevier Ireland Ltd. All rights reserved.

Electroacupunctre improves motor impairment via inhibition of microglia-mediated neuroinflammation in the sensorimotor cortex after ischemic stroke.

PubMed

Liu, Weilin; Wang, Xian; Yang, Shanli; Huang, Jia; Xue, Xiehua; Zheng, Yi; Shang, Guanhao; Tao, Jing; Chen, Lidian

2016-04-15

Electroacupuncture (EA) is one of the safety and effective therapies for improving neurological and sensorimotor impairment via blockade of inappropriate inflammatory responses. However, the mechanisms of anti-inflammation involved is far from been fully elucidated. Focal cerebral ischemic stroke was administered by the middle cerebral artery occlusion and reperfusion (MCAO/R) surgery. The MCAO/R rats were accepted EA treatment at the LI 11 and ST 36 acupoints for consecutive 3days. The neurological outcome, animal behaviors test and molecular biology assays were used to evaluate the MCAO/R model and therapeutic effect of EA. EA treatment for MCAO rats showed a significant reduction in the infarct volumes accompanied by functional recovery in mNSS outcomes, motor function performances. The possible mechanisms that EA treatment attenuated the over-activation of Iba-1 and ED1 positive microglia in the peri-infract sensorimotor cortex. Simultaneously, both tissue and serum protein levels of the tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) were decreased by EA treatment in MCAO/R injured rats. The levels of inflammatory cytokine tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) were decreased in the peri-infract sensorimotor cortex and blood serum of MCAO/R injured rats after EA treatment. Furthermore, we found that EA treatment prevented from the nucleus translocation of NF-κB p65 and suppressed the expression of p38 mitogen-activated protein kinase (p38 MAPK) and myeloid differentiation factor 88 (MyD88) in the peri-infract sensorimotor cortex. The findings from this study indicated that EA improved the motor impairment via inhibition of microglia-mediated neuroinflammation that invoked NF-κB p65, p38 MAPK and MyD88 produced proinflammatory cytokine in the peri-infract sensorimotor cortex of rats following ischemic stroke. Copyright © 2016 Elsevier Inc. All rights reserved.

Phosphorylated recombinant HSP27 protects the brain and attenuates blood-brain barrier disruption following stroke in mice receiving intravenous tissue-plasminogen activator.

PubMed

Shimada, Yoshiaki; Shimura, Hideki; Tanaka, Ryota; Yamashiro, Kazuo; Koike, Masato; Uchiyama, Yasuo; Urabe, Takao; Hattori, Nobutaka

2018-01-01

Loss of integrity of the blood-brain barrier (BBB) in ischemic stroke victims initiates a devastating cascade of events causing brain damage. Maintaining the BBB is important to preserve brain function in ischemic stroke. Unfortunately, recombinant tissue plasminogen activator (tPA), the only effective fibrinolytic treatment at the acute stage of ischemic stroke, also injures the BBB and increases the risk of brain edema and secondary hemorrhagic transformation. Thus, it is important to identify compounds that maintain BBB integrity in the face of ischemic injury in patients with stroke. We previously demonstrated that intravenously injected phosphorylated recombinant heat shock protein 27 (prHSP27) protects the brains of mice with transient middle cerebral artery occlusion (tMCAO), an animal stroke-model. Here, we determined whether prHSP27, in addition to attenuating brain injury, also decreases BBB damage in hyperglycemic tMCAO mice that had received tPA. After induction of hyperglycemia and tMCAO, we examined 4 treatment groups: 1) bovine serum albumin (BSA), 2) prHSP27, 3) tPA, 4) tPA plus prHSP27. We examined the effects of prHSP27 by comparing the BSA and prHSP27 groups and the tPA and tPA plus prHSP27 groups. Twenty-four hours after injection, prHSP27 reduced infarct volume, brain swelling, neurological deficits, the loss of microvessel proteins and endothelial cell walls, and mortality. It also reduced the rates of hemorrhagic transformation, extravasation of endogenous IgG, and MMP-9 activity, signs of BBB damage. Therefore, prHSP27 injection attenuated brain damage and preserved the BBB in tPA-injected, hyperglycemic tMCAO experimental stroke-model mice, in which the BBB is even more severely damaged than in simple tMCAO mice. The attenuation of brain damage and BBB disruption in the presence of tPA suggests the effectiveness of prHSP27 and tPA as a combination therapy. prHSP27 may be a novel therapeutic agent for ischemic stroke patients whose BBBs are

Stroke treatment in rats with tail temperature increase by 40-min moxibustion.

PubMed

Chen, Ri-Xin; Lv, Zhi-Mai; Chen, Ming-Ren; Yi, Fan; An, Xin; Xie, Ding-Yi

2011-10-03

The distant heat induced by suspended moxibustion (SM) for 40 min is confirmed to have a favorable effect in treating diseases such as ischemic brain injury in the clinical setting, but its precise mechanism remains to be explained. Since a similar reaction to the phenomenon of distant heat is found in some transient middle cerebral artery occlusion (tMCAO) rats treated by a 40-min SM session with tail temperature increase (TTI), we hereby study its mechanism by comparing the neuroprotective effect of 40 min's SM with TTI to those without. The experimental results show that 40 min's SM with TTI can significantly reduce the infarct volume and neurological deficit score in tMCAO rats. Western blot demonstrates that a reduction in the levels of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) expression in tMCAO rats with TTI is more striking than that of the rats without TTI. The expression of caspase-3 protein is inhibited in tMCAO rats with TTI. The results suggest that the efficacy of SM for 40 min with TTI is higher than that without. Although neuroprotective effects present in tMCAO rats with and without TTI, those with TTI revealed a higher level of anti-inflammation effect and exhibited an anti-apoptosis effect. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

[Temporomandibular joint, occlusion and bruxism].

PubMed

Orthlieb, J D; Ré, J P; Jeany, M; Giraudeau, A

2016-09-01

Temporomandibular joint and dental occlusion are joined for better and worse. TMJ has its own weaknesses, sometimes indicated by bad functional habits and occlusal disorders. Occlusal analysis needs to be addressed simply and clearly. The term "malocclusion" is not reliable to build epidemiological studies, etiologic mechanisms or therapeutic advice on this "diagnosis". Understanding the impact of pathogenic malocclusion is not just about occlusal relationships that are more or less defective, it requires to locate them within the skeletal framework, the articular and behavioural context of the patient, and above all to assess their impact on the functions of the masticatory system. The TMJ-occlusion couple is often symbiotic, developing together in relation to its environment, compensating for its own shortcomings. However, a third partner may alter this relationship, such as bruxism, or more generally oral parafunctions, trauma or an interventionist practitioner. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Multi-unit activity suppression and sensorimotor deficits after endothelin-1-induced middle cerebral artery occlusion in conscious rats.

PubMed

Moyanova, Slavianka; Kirov, Roumen; Kortenska, Lidia

2003-08-15

Conscious Wistar rats with stereotaxically and unilaterally implanted cannula just above the middle cerebral artery (MCA) were injected with the powerful vasoconstrictor peptide endothelin-1 (ET1, 60 pmol in 3 microl). The purpose was to examine the long-term (from the 1st to the 14th day) changes in neuronal bioelectrical activity together with sensorimotor deficits after ET1-induced MCA occlusion (MCAO). Extracellular multi-unit activity (MUA) recorded from the ipsilateral fronto-parietal cortical area (supplied by MCA) and sensorimotor behavior (one postural reflex test and six limb placing tests) were examined. A significant suppression of the multi-unit activity was observed until the 14th day post-ET1. The rats exhibited significant unilateral sensorimotor deficits with a maximum at the 3-7 days after ET1 and a spontaneous partial recovery by days 11-14. A significant correlation was found between the suppression of the multi-unit activity and the sensorimotor deficits between the 3rd and the 10th day post-ET1. The results suggest that studying the bioelectrical activity in combination with the behavioral sensorimotor functions may be of use to assess the functional disturbances associated with focal cerebral ischemia and would help to examine the therapeutic benefits of various cerebroprotective treatments before initiating human clinical trials.

Neuronal precursor cell proliferation in the hippocampus after transient cerebral ischemia: a comparative study of two rat strains using stereological tools.

PubMed

Kelsen, Jesper; Larsen, Marianne H; Sørensen, Jens Christian; Møller, Arne; Frøkiaer, Jørgen; Nielsen, Søren; Nyengaard, Jens R; Mikkelsen, Jens D; Rønn, Lars Christian B

2010-04-06

We are currently investigating microglial activation and neuronal precursor cell (NPC) proliferation after transient middle cerebral artery occlusion (tMCAo) in rats. This study aimed: (1) to investigate differences in hippocampal NPC proliferation in outbred male spontaneously hypertensive rats (SHRs) and Sprague-Dawley rats (SDs) one week after tMCAo; (2) to present the practical use of the optical fractionator and 2D nucleator in stereological brain tissue analyses; and (3) to report our experiences with an intraluminal tMCAo model where the occluding filament is advanced 22 mm beyond the carotid bifurcation and the common carotid artery is clamped during tMCAo. Twenty-three SDs and twenty SHRs were randomized into four groups subjected to 90 minutes tMCAo or sham. BrdU (50 mg/kg) was administered intraperitoneally twice daily on Day 4 to 7 after surgery. On Day 8 all animals were euthanized. NeuN-stained tissue sections were used for brain and infarct volume estimation with the 2D nucleator and Cavalieri principle. Brains were studied for the presence of activated microglia (ED-1) and hippocampal BrdU incorporation using the optical fractionator. We found no significant difference or increase in post-ischemic NPC proliferation between the two strains. However, the response to remote ischemia may differ between SDs and SHRs. In three animals increased post-stroke NPC proliferation was associated with hippocampal ischemic injury. The mean infarct volume was 89.2 +/- 76.1 mm3 in SHRs and 16.9 +/- 22.7 mm3 in SDs (p < 0.005). Eight out of eleven SHRs had ischemic neocortical damage in contrast to only one out of 12 SDs. We observed involvement of the anterior choroidal and hypothalamic arteries in several animals from both strains and the anterior cerebral artery in two SHRs. We found no evidence of an early hippocampal NPC proliferation one week after tMCAo in both strains. Infarction within the anterior choroidal artery could induce hippocampal ischemia and

Regulation of body temperature and neuroprotection by endogenous interleukin-6 in cerebral ischemia.

PubMed

Herrmann, Oliver; Tarabin, Victoria; Suzuki, Shigeaki; Attigah, Nicolas; Coserea, Irinel; Schneider, Armin; Vogel, Johannes; Prinz, Simone; Schwab, Stefan; Monyer, Hannah; Brombacher, Frank; Schwaninger, Markus

2003-04-01

Although the function of fever is still unclear, it is now beyond doubt that body temperature influences the outcome of brain damage. An elevated body temperature is often found in stroke patients and denotes a bad prognosis. However, the pathophysiologic basis and treatment options of elevated body temperature after stroke are still unknown. Cerebral ischemia rapidly induced neuronal interleukin-6 (IL-6) expression in mice. In IL-6-deficient mice, body temperature was markedly decreased after middle cerebral artery occlusion (MCAO), but infarct size was comparable to that in control mice. If body temperature was controlled by external warming after MCAO, IL-6-deficient mice had a reduced survival, worse neurologic status, and larger infarcts than control animals. In cell culture, IL-6 exerted an antiapoptotic and neuroprotective effect. These data suggest that IL-6 is a key regulator of body temperature and an endogenous neuroprotectant in cerebral ischemia. Neuroprotective properties apparently compensate for its pyretic action after MCAO and enhance the safety of this endogenous pyrogen.

Resting-state Functional Magnetic Resonance Imaging Analysis of Brain Functional Activity in Rats with Ischemic Stroke Treated by Electro-acupuncture.

PubMed

Liang, Shengxiang; Lin, Yunjiao; Lin, Bingbing; Li, Jianhong; Liu, Weilin; Chen, Lidian; Zhao, Shujun; Tao, Jing

2017-09-01

To evaluate whether electro-acupuncture (EA) treatment at acupoints of Zusanli (ST 36) and Quchi (LI 11) could reduce motor impairments and enhance brain functional recovery in rats with ischemic stroke. A rat model of middle cerebral artery occlusion (MCAO) was established. EA at ST 36 and LI 11was started at 24 hours (MCAO + EA group) after ischemic stroke. The nontreatment (MCAO) and sham-operated control (SC) groups were included as controls. The neurologic deficits of all groups were assessed by Zea Longa scores and the modified neurologic severity scores on 24 hours and 8 days after MCAO. To further investigate the effect of EA on infract volume and brain function, magnetic resonance imaging was used to estimate the brain lesion and brain neural activities of each group at 8 days after ischemic stroke. Within 1 week after EA treatment, the neurologic deficits were significantly alleviated, and the cerebral infarctions were improved, including visual cortex, motor cortex, striatum, dorsal thalamus, and hippocampus. Furthermore, whole brain neural activities of auditory cortex, lateral nucleus group of dorsal thalamus, hippocampus, motor cortex, orbital cortex, sensory cortex, and striatum were decreased in MCAO group, whereas that of brain neural activities were increased after EA treatment, suggesting these brain regions are in accordance with the brain structure analysis. EA at ST 36 and LI 11 could enhance the neural activity of motor function-related brain regions, including motor cortex, dorsal thalamus, and striatum in rats, which is a potential treatment for ischemia stroke. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Catheter Occlusion in Home Infusion: The Influence of Needleless Connector Design on Central Catheter Occlusion.

PubMed

Williams, Ann

Thrombotic catheter occlusion is a common complication associated with central venous catheters (CVCs). A wide variety of needleless connectors that differ greatly in design and function are available for use with CVCs; however, there are a limited number of studies comparing the catheter occlusion rate associated with differently designed needleless connectors. This retrospective observational study compared occlusion rates associated with a split-septum neutral-displacement needleless connector versus those of a solid-surface neutral-reflux needleless connector in patients undergoing home infusion therapy. The neutral-reflux needleless connector was associated with a significant reduction in occlusion rate and thrombolytic use versus the neutral-displacement needleless connector.

Robust face alignment under occlusion via regional predictive power estimation.

PubMed

Heng Yang; Xuming He; Xuhui Jia; Patras, Ioannis

2015-08-01

Face alignment has been well studied in recent years, however, when a face alignment model is applied on facial images with heavy partial occlusion, the performance deteriorates significantly. In this paper, instead of training an occlusion-aware model with visibility annotation, we address this issue via a model adaptation scheme that uses the result of a local regression forest (RF) voting method. In the proposed scheme, the consistency of the votes of the local RF in each of several oversegmented regions is used to determine the reliability of predicting the location of the facial landmarks. The latter is what we call regional predictive power (RPP). Subsequently, we adapt a holistic voting method (cascaded pose regression based on random ferns) by putting weights on the votes of each fern according to the RPP of the regions used in the fern tests. The proposed method shows superior performance over existing face alignment models in the most challenging data sets (COFW and 300-W). Moreover, it can also estimate with high accuracy (72.4% overlap ratio) which image areas belong to the face or nonface objects, on the heavily occluded images of the COFW data set, without explicit occlusion modeling.

Prefrontal Hemodynamic Changes Associated with Subjective Sense of Occlusal Discomfort

PubMed Central

Kobayashi, Goh; Hayama, Rika; Ikuta, Ryuhei; Onozouka, Minoru; Wake, Hiroyuki; Shimada, Atsushi; Shibuya, Tomoaki; Tamaki, Katsushi

2015-01-01

We used functional near-infrared spectroscopy to measure prefrontal brain activity accompanying the physical sensation of oral discomfort that arose when healthy young-adult volunteers performed a grinding motion with mild occlusal elevation (96 μm). We simultaneously evaluated various forms of occlusal discomfort using the visual analogue scale (VAS) and hemodynamic responses to identify the specific prefrontal activity that occurs with increased occlusal discomfort. The Oxy-Hb responses of selected channels in the bilateral frontopolar and dorsolateral prefrontal cortices increased in participants who reported increased severity of occlusal discomfort, while they decreased in those who reported no change or decreased occlusal discomfort during grinding. Moreover, the cumulative values of Oxy-Hb response in some of these channels were statistically significant predictive factors for the VAS scores. A generalized linear model analysis of Oxy-Hb signals in a group of participants who reported increased discomfort further indicated significant cerebral activation in the right frontopolar and dorsolateral prefrontal cortices that overlapped with the results of correlation analyses. Our results suggest that the increased hemodynamic responses in the prefrontal area reflect the top-down control of attention and/or self-regulation against the uncomfortable somatosensory input, which could be a possible marker to detect the subjective sense of occlusal discomfort. PMID:26090407

Overexpression of Human S100B Exacerbates Brain Damage and Periinfarct Gliosis After Permanent Focal Ischemia

PubMed Central

Mori, Takashi; Tan, Jun; Arendash, Gary W.; Koyama, Naoki; Nojima, Yoshiko; Town, Terrence

2009-01-01

Background and Purpose We have previously demonstrated that augmented and prolonged activation of astrocytes detrimentally influences both the subacute and chronic phases of cerebral ischemia. Furthermore, we have suggested that the astrocyte-derived protein S100B may be important in these pathogenic events. However, the causal relationship between S100B and exacerbation of brain damage in vivo remains to be elucidated. Methods Using transgenic mice overexpressing human S100B (Tg huS100B mice), we examined whether S100B plays a cardinal role in aggravation of brain damage after permanent middle cerebral artery occlusion (pMCAO). Results Tg huS100B mice had significantly larger infarct volumes and worse neurological deficits at any time point examined after pMCAO as compared with CD-1 background strain-matched control mice. Infarct volumes in Tg huS100B mice were significantly increased from 1 to 3 and 5 days after pMCAO (delayed infarct expansion), whereas those in control mice were not significantly altered. S100, glial fibrillary acidic protein, and Iba1 burdens in the periinfarct area were significantly increased through to 7 days after pMCAO in Tg huS100B mice, whereas those in control mice reached a plateau at 3 days after pMCAO. Conclusions These results provide genetic evidence that overexpression of human S100B acts to exacerbate brain damage and periinfarct reactive gliosis (astrocytosis and microgliosis) during the subacute phase of pMCAO. PMID:18451356

Ambient occlusion effects for combined volumes and tubular geometry.

PubMed

Schott, Mathias; Martin, Tobias; Grosset, A V Pascal; Smith, Sean T; Hansen, Charles D

2013-06-01

This paper details a method for interactive direct volume rendering that computes ambient occlusion effects for visualizations that combine both volumetric and geometric primitives, specifically tube-shaped geometric objects representing streamlines, magnetic field lines or DTI fiber tracts. The algorithm extends the recently presented the directional occlusion shading model to allow the rendering of those geometric shapes in combination with a context providing 3D volume, considering mutual occlusion between structures represented by a volume or geometry. Stream tube geometries are computed using an effective spline-based interpolation and approximation scheme that avoids self-intersection and maintains coherent orientation of the stream tube segments to avoid surface deforming twists. Furthermore, strategies to reduce the geometric and specular aliasing of the stream tubes are discussed.

Ambient Occlusion Effects for Combined Volumes and Tubular Geometry

PubMed Central

Schott, Mathias; Martin, Tobias; Grosset, A.V. Pascal; Smith, Sean T.; Hansen, Charles D.

2013-01-01

This paper details a method for interactive direct volume rendering that computes ambient occlusion effects for visualizations that combine both volumetric and geometric primitives, specifically tube-shaped geometric objects representing streamlines, magnetic field lines or DTI fiber tracts. The algorithm extends the recently presented the directional occlusion shading model to allow the rendering of those geometric shapes in combination with a context providing 3D volume, considering mutual occlusion between structures represented by a volume or geometry. Stream tube geometries are computed using an effective spline-based interpolation and approximation scheme that avoids self-intersection and maintains coherent orientation of the stream tube segments to avoid surface deforming twists. Furthermore, strategies to reduce the geometric and specular aliasing of the stream tubes are discussed. PMID:23559506

Modelling the effect of laminar axially directed blood flow on the dissolution of non-occlusive blood clots.

PubMed

Sersa, I; Vidmar, J; Grobelnik, B; Mikac, U; Tratar, G; Blinc, A

2007-06-07

Axially directed blood plasma flow can significantly accelerate thrombolysis of non-occlusive blood clots. Viscous forces caused by shearing of blood play an essential role in this process, in addition to biochemical fibrinolytic reactions. An analytical mathematical model based on the hypothesis that clot dissolution dynamics is proportional to the power of the flowing blood plasma dissipated along the clot is presented. The model assumes cylindrical non-occlusive blood clots with the flow channel in the centre, in which the flow is assumed to be laminar and flow rate constant at all times during dissolution. Effects of sudden constriction on the flow and its impact on the dissolution rate are also considered. The model was verified experimentally by dynamic magnetic resonance (MR) microscopy of artificial blood clots dissolving in an in vitro circulation system, containing plasma with a magnetic resonance imaging contrast agent and recombinant tissue-type plasminogen activator (rt-PA). Sequences of dynamically acquired 3D low resolution MR images of entire clots and 2D high resolution MR images of clots in the axial cross-section were used to evaluate the dissolution model by fitting it to the experimental data. The experimental data fitted well to the model and confirmed our hypothesis.

Infiltration of invariant natural killer T cells occur and accelerate brain infarction in permanent ischemic stroke in mice.

PubMed

Wang, Zhen-Kui; Xue, Li; Wang, Tao; Wang, Xiu-Jie; Su, Zhi-Qiang

2016-10-28

Invariant natural killer T (iNKT) cells are a unique subset of T cells that have been implicated in inflammation, atopy, autoimmunity, infections, and cancer. Although iNKT cells have been extensively studied over the past decade, its role in the pathogenesis of ischemic brain injury is still largely unknown. In our study, we determined whether iNKT cells infiltration occur in a mouse model of permanent cerebral ischemia. C57BL6/J male mice were treated with either alpha-galactosylceramide (α-GalCer) or vehicle control before undergoing permanent middle cerebral artery occlusion (pMCAO). α-GalCer, a glycolipid antigen, specifically activates iNKT cells by a CD1d-restricted mechanism. Using flow cytometry, 10,000 leukocytes (CD45 high cells) from the ischemic hemisphere and peripheral blood respectively were analyzed to determine the number of NK1.1 + CD3 + cells at 3, 12, 24 and 48h post-pMCAO. Cerebral infarct size, brain edema and morphological characteristics were measured at the stipulated time points by 2,3,5-triphenyltetrazolium chloride (TTC) staining, weighing, and H&E staining. The levels of IFN-γ and TNF-α in brain tissue and serum were assessed by immunohistochemistry and ELISA respectively. We found that the number of iNKT cells started increasing from 12h (PB sample) and 24h (ischemic hemisphere sample) respectively in the vehicle treated group. iNKT cells infiltration occurred at an earlier time-point compared in the α-GalCer treated group (T=3H vs T=12H in PB sample; T=12H vs T=24H in ischemic hemisphere sample). Brain water content at 12h and 24h was significantly higher in pMCAO+α-GalCer mice compared to pMCAO+vehicle mice which was in turn higher than mice that underwent sham surgery. Aggravated morphological abnormalities in HE-stained neurons and significantly increased neurons with pyknotic nuclei and cavitation in the ischemic region were observed at 24h in the pMCAO+α-GalCer and pMCAO+vehicle groups. Cerebral infarct volume

TRANSCUTANEOUS CERVICAL VAGUS NERVE STIMULATION AMELIORATES ACUTE ISCHEMIC INJURY IN RATS

PubMed Central

Ay, Ilknur; Nasser, Rena; Simon, Bruce; Ay, Hakan

2016-01-01

Background Direct stimulation of the vagus nerve in the neck via surgically implanted electrodes is protective in animal models of stroke. We sought to determine the safety and efficacy of a non-invasive cervical VNS (nVNS) method using surface electrodes applied to the skin overlying the vagus nerve in the neck in a model of middle cerebral artery occlusion (MCAO). Methods nVNS was initiated variable times after MCAO hour in rats (n=33). Control animals received sham stimulation (n=33). Infarct volume and functional outcome were assessed on day 7. Brains were processed by immunohistochemistry for microglial activation and cytokine levels. The ability of nVNS to activate the nucleus tractus solitarius (NTS) was assessed using c-Fos immunohistochemistry. Results Infarct volume was 43.15±3.36 percent of the contralateral hemisphere (PCH) in control and 28.75±4.22 PCH in nVNS-treated animals (p<0.05). The effect of nVNS on infarct size was consistent when stimulation was initiated up to 4 hours after MCAO. There was no difference in heart rate and blood pressure between control and nVNS-treated animals. The number of c-Fos positive cells was 32.4±10.6 and 6.2±6.3 in the ipsilateral NTS (p<0.05) and 30.4±11.2 and 5.8±4.3 in the contralateral NTS (p<0.05) in nVNS-treated and control animals, respectively. nVNS reduced the number of Iba-1, CD68, and TNF-α positive cells and increased the number of HMGB1 positive cells. Conclusions nVNS inhibits ischemia-induced immune activation and reduces the extent of tissue injury and functional deficit in rats without causing cardiac or hemodynamic adverse effects when initiated up to 4 hours after MCAO. PMID:26723020

Risk of bias reporting in the recent animal focal cerebral ischaemia literature.

PubMed

Bahor, Zsanett; Liao, Jing; Macleod, Malcolm R; Bannach-Brown, Alexandra; McCann, Sarah K; Wever, Kimberley E; Thomas, James; Ottavi, Thomas; Howells, David W; Rice, Andrew; Ananiadou, Sophia; Sena, Emily

2017-10-15

Findings from in vivo research may be less reliable where studies do not report measures to reduce risks of bias. The experimental stroke community has been at the forefront of implementing changes to improve reporting, but it is not known whether these efforts are associated with continuous improvements. Our aims here were firstly to validate an automated tool to assess risks of bias in published works, and secondly to assess the reporting of measures taken to reduce the risk of bias within recent literature for two experimental models of stroke. We developed and used text analytic approaches to automatically ascertain reporting of measures to reduce risk of bias from full-text articles describing animal experiments inducing middle cerebral artery occlusion (MCAO) or modelling lacunar stroke. Compared with previous assessments, there were improvements in the reporting of measures taken to reduce risks of bias in the MCAO literature but not in the lacunar stroke literature. Accuracy of automated annotation of risk of bias in the MCAO literature was 86% (randomization), 94% (blinding) and 100% (sample size calculation); and in the lacunar stroke literature accuracy was 67% (randomization), 91% (blinding) and 96% (sample size calculation). There remains substantial opportunity for improvement in the reporting of animal research modelling stroke, particularly in the lacunar stroke literature. Further, automated tools perform sufficiently well to identify whether studies report blinded assessment of outcome, but improvements are required in the tools to ascertain whether randomization and a sample size calculation were reported. © 2017 The Author(s).

Metabolomics-based mechanisms exploration of Huang-Lian Jie-Du decoction on cerebral ischemia via UPLC-Q-TOF/MS analysis on rat serum.

PubMed

Zhu, Baojie; Cao, Huiting; Sun, Limin; Li, Bo; Guo, Liwei; Duan, Jinao; Zhu, Huaxu; Zhang, Qichun

2018-04-24

Huang-Lian Jie-Du decoction (HLJDD), a traditional formula of Chinese medicine constituted with Rhizoma Coptidis, RadixScutellariae, CortexPhellodendri amurensis and Fructus Gardeniae, exhibits unambiguous therapeutic effect on cerebral ischemia via multi-targets action. Further investigation, however, is still required to explore the relationship between those mechanisms and targets through system approaches. Rats of cerebral ischemia were completed by middle cerebral artery occlusion (MCAO) with reperfusion. Following evaluation of pharmacological actions of HLJDD on MCAO rats, the plasma samples from rats of control, MCAO and HLJDD-treated MCAO groups were prepared strictly and subjected to ultra-performance liquid chromatography quadrupole time of flight mass spectrometry for metabolites analysis. The raw mass data were imported to MassLynx software for peak detection and alignment, and further introduced to EZinfo 2.0 software for orthogonal projection to latent structures analysis, principal component analysis and partial least-squares-discriminant analysis. The metabolic pathways assay of those potential biomarkers were performed with MetaboAnalyst through the online database, HMDB, Metlin, KEGG and SMPD. Those intriguing metabolic pathways were further investigated via biochemical assay. HLJDD ameliorated the MCAO-induce cerebral damage and blocked the severe inflammation response. There were nineteen different biomarkers identified among control, MCAO and HLJDD-treated MCAO groups. Ten metabolic pathways were proposed from these significant metabolites. Incorporation with the biochemical assay of cerebral tissue, modulation of metabolic stress, regulation glutamate/GABA-glutamine cycle and enhancement of cholinergic neurons function were explored that involved in the actions of HLJDD on cerebral ischemia. HLJDD achieves therapeutic action on cerebral ischemia via coordinating the basic pathophysiological network of metabolic stress, glutamate metabolism

Decrease of tight junction integrity in the ipsilateral thalamus during the acute stage after focal infarction and ablation of the cerebral cortex in rats.

PubMed

Li, Jing-Jing; Xing, Shi-Hui; Zhang, Jian; Hong, Hua; Li, Yi-Liang; Dang, Chao; Zhang, Yu-Sheng; Li, Chuo; Fan, Yu-Hua; Yu, Jian; Pei, Zhong; Zeng, Jin-Sheng

2011-11-01

1. Whether damage to the blood-brain barrier (BBB) occurs in remote areas after a focal cortical lesion remains unknown. The present study investigated tight junction-related proteins and tight junction microstructure in the ipsilateral thalamus during the acute stage after middle cerebral artery occlusion (MCAO) and cortical aspiration lesion (CAL) in rats. 2. Thirty-six hypertensive and normotensive rats were subjected to MCAO or CAL; another 18 rats in each group were submitted to sham operation. Zonula Occluden (ZO)-1, occludin and albumin were detected by western blotting 12 and 24 h after surgery. Tight junction microstructure was evaluated using electron microscopy, whereas albumin location in the ipsilateral thalamus was determined using double immunostaining for albumin and occludin or albumin and neuronal nuclei (NeuN) 24 h after surgery. 3. Twenty-four hours after MCAO or CAL, occludin expression was reduced to 78.4% and 81.3%, respectively, compared with control. A reduction in ZO-1 expression in the ipsilateral thalamus (to 79%) was seen only after CAL (P < 0.05). Membrane contact at the tight junction was discontinuous in the ipsilateral thalamus in both MCAO and CAL rats. Albumin levels were 23.2% and 82.5% higher in the ipsilateral thalamus after MCAO and CAL, respectively (P < 0.05). The percentage of the albumin-positive area that coincided with the occludin-positive area in the MCAO and CAL groups was 76.8% and 64.6%, respectively, indicating that albumin was mainly localized around the microvessels. 4. The results of the present study suggest that tight junction integrity decreases during the acute stage in the ipsilateral thalamus after MCAO and CAL in rats. © 2011 The Authors. Clinical and Experimental Pharmacology and Physiology © 2011 Blackwell Publishing Asia Pty Ltd.

Electroacupuncture ameliorating post-stroke cognitive impairments via inhibition of peri-infarct astroglial and microglial/macrophage P2 purinoceptors-mediated neuroinflammation and hyperplasia.

PubMed

Huang, Jia; You, Xiaofang; Liu, Weilin; Song, Changming; Lin, Xiaomin; Zhang, Xiufeng; Tao, Jing; Chen, Lidian

2017-10-10

During ischemic stroke (IS), adenosine 5'-triphosphate (ATP) is released from damaged nerve cells of the infract core region to the extracellular space, invoking peri-infarct glial cellular P2 purinoceptors singling, and causing pro-inflammatory cytokine secretion, which is likely to initiate or aggravate motor and cognitive impairment. It has been proved that electroacupuncture (EA) is an effective and safe strategy used in anti-inflammation. However, EA for the role of purine receptors in the central nervous system has not yet been reported. Ischemia-reperfusion injured rat model was induced by middle cerebral artery occlusion and reperfusion (MCAO/R). EA treatment at the DU 20 and DU 24 acupoints treatment were conducted to rats from the 12 h after MCAO/R injury for consecutive 7 days. The neurological outcomes, infarction volumes and the level of astroglial and microglial/macrophage hyperplasia, inflammatory cytokine and P2X7R and P2Y1R expression in the peri-infarct hippocampal CA1and sensorimotor cortex were investigated after IS to evaluate the MCAO/R model and therapeutic mechanism of EA treatment. EA effectively reduced the level of pro-inflammatory cytokine interleukin-1β (IL-1β) as evidenced by reduction in astroglial and microglial/macrophage hyperplasia and the levels of P2X7R and ED1, P2X7R and GFAP, P2Y1R and ED1, P2Y1R and GFAP co-expression in peri-infarct hippocampal CA1 and sensorimotor cortex compared with that of MCAO/R model and Non-EA treatment, accompanied by the improved neurological deficit and the motor and memory impairment outcomes. Therefore, our data support the hypothesis that EA could exert its anti-inflammatory effect via inhibiting the astroglial and microglial/macrophage P2 purinoceptors (P2X7R and P2Y1R)-mediated neuroinflammation after MCAO/R injury. Astroglial and microglial/macrophage P2 purinoceptors-mediated neuroinflammation and hyperplasia in peri-infarct hippocampal CA1 and sensorimotor cortex were attenuated by EA

Systematic and detailed analysis of behavioural tests in the rat middle cerebral artery occlusion model of stroke: Tests for long-term assessment

PubMed Central

Diaz, Claris; Farr, Tracy D; Harrison, David J; Fuller, Anna; Tokarczuk, Paweł F; Stewart, Andrew J; Paisey, Stephen J; Dunnett, Stephen B

2016-01-01

In order to test therapeutics, functional assessments are required. In pre-clinical stroke research, there is little consensus regarding the most appropriate behavioural tasks to assess deficits, especially when testing over extended times in milder models with short occlusion times and small lesion volumes. In this study, we comprehensively assessed 16 different behavioural tests, with the aim of identifying those that show robust, reliable and stable deficits for up to two months. These tasks are regularly used in stroke research, as well as being useful for examining striatal dysfunction in models of Huntington’s and Parkinson’s disease. Two cohorts of male Wistar rats underwent the intraluminal filament model of middle cerebral artery occlusion (30 min) and were imaged 24 h later. This resulted in primarily subcortical infarcts, with a small amount of cortical damage. Animals were tested, along with sham and naïve groups at 24 h, seven days, and one and two months. Following behavioural testing, brains were processed and striatal neuronal counts were performed alongside measurements of total brain and white matter atrophy. The staircase, adjusting steps, rotarod and apomorphine-induced rotations were the most reliable for assessing long-term deficits in the 30 min transient middle cerebral artery occlusion model of stroke. PMID:27317655

Inhibition of the NLRP3-inflammasome as a potential approach for neuroprotection after stroke.

PubMed

Ismael, Saifudeen; Zhao, Liang; Nasoohi, Sanaz; Ishrat, Tauheed

2018-04-13

Activation of the NOD-like receptor protein (NLRP3)-inflammasome has been postulated to mediate inflammatory responses to brain damage during ischemic/reperfusion (I/R) injury. We therefore hypothesized that MCC950, a selective NLRP3-inflammasome inhibitor provides protection in mouse model of transient middle cerebral artery occlusion (tMCAO). Focal cerebral ischemia was induced by 60 min tMCAO followed by intraperitoneal administration of MCC950 (50 mg/kg) or saline at 1 h and 3 h post-occlusion. After 24 h of I/R, mice were tested for neurological outcome and were sacrificed for the analysis of infarct size and estimating NLRP3-inflammasome and apoptotic markers as well. Spectrophotometric method was used to determine hemoglobin (Hb) content as a marker of intracerebral hemorrhage. MCC950-treated mice showed a substantial reduction in infarction, edema and Hb content compared to saline controls in parallel with improved neurological deficits. MCC950 reduced expression of NLRP3-inflammasome cleavage products Caspase-1 and interlukin-1β (IL-1β) in penumbral region. These protective effects of MCC950 were associated with decreased TNF-α levels as well as poly (ADP-ribose) polymerase (PARP) and Caspase-3 cleavage and paralleled less phosphrylated NFκBp65 and IκBα levels. Taken together, these data indicate that inhibition of NLRP3-inflammasome with MCC950 has therapeutic potential in ischemic stroke models. Further investigations into the therapeutic efficacy and protocols are needed to confirm whether MCC950 treatment could be a promising candidate for clinical trials.

Cell culture protection and in vivo neuroprotective capacity of flavonoids.

PubMed

Dajas, Federico; Rivera, Felicia; Blasina, Fernanda; Arredondo, Florencia; Echeverry, Carolina; Lafon, Laura; Morquio, Andrea; Heinzen, Horacio; Heizen, Horacio

2003-01-01

Flavonoids are an important group of recognized antioxidants ubiquitous in fruits, vegetables and herbs. There are epidemiological evidences for the stroke-protecting capacity of flavonoids and while the neuroprotective power of complex extracts rich in flavonoids like those of Ginkgo biloba, green tea or lyophilized red wine have been demonstrated in several studies, neuroprotection by individual flavonoids has been poorly studied in vivo. The neuroprotective capacity of individual flavonoids was studied in PC12 cells in culture and in a model of permanent focal ischemia (permanent Middle Cerebral Artery Occlusion - pMCAO). In the in vivo experiments, flavonoids were administered in lecithin preparations to facilitate the crossing of the blood brain barrier. The simultaneous incubation of PC12 cells with 200 micro M hydrogen peroxide (H2O2) and different flavonoids for 30 min resulted in a conspicuous profile: quercetin, fisetin, luteolin and myricetin significantly increased cell survival while catechin, kaempherol and taxifolin did not. Quercetin was detected in brain tissue 30 min and 1 h after intraperitoneal administration. When one of the protective flavonoids (quercetin) and one of those that failed to increase PC12 cell survival (catechin) were assessed for their protective capacity in the pMCAO model, administered i.p. 30 min after vessel occlusion, quercetin significantly decreased the brain ischemic lesion while catechin did not. It is concluded that when administered in liposomal preparations, flavonoids structurally related to quercetin could become leads for the development of a new generation of molecules to be clinically effective in human brain ischemia.

Comparative study to evaluate the accuracy of polyether occlusal bite registration material and occlusal registration wax as a guide for occlusal reduction during tooth preparation.

PubMed

Joshi, Niranjan; Shetty, Sridhar N; Prasad, Krishna D

2013-01-01

The use of different materials and techniques has been studied to decide the safest quantum of reduction of the occlusal surfaces. However, these methods provide limited information as to the actual amount of reduction with limitations in accuracy, accessibility and complexity. The objective of this study was to compare and evaluate the reliability of the most commonly used occlusal registration wax that with polyether bite registration material as a guide for occlusal reduction required during tooth preparations. For the purpose of this study, 25 abutment teeth requiring tooth preparation for fixed prosthesis were selected and tooth preparations carried out. Modeling wax strips of specific dimensions were placed onto the cast of prepared tooth, which was mounted on maximum intercuspation on the articulator and the articulator was closed. The thickness of the wax registration was measured at three zones namely two functional cusps and central fossa. Similar measurements were made using the polyether bite registration material and prosthesis at the same zones. The data was tabulated and was subjected to statistical analysis using anova test and Tukey honestly significant difference test. The differences in thickness between wax record and prosthesis by 0.1346 mm, whereas the difference between polyether and prosthesis was 0.02 mm with a P value of 0.042, which is statistically significant. This means that the wax record was 8.25% larger than the prosthesis while polyether was just 1.27% larger than the prosthesis. The clinical significance of the above analysis is that Ramitec polyether bite registration material is most suitable material when compared with commonly used modeling wax during the tooth preparation.

Optimal occlusion uniformly partitions red blood cells fluxes within a microvascular network

PubMed Central

Tu, Shenyinying; Liu, Yu-Hsiu; Savage, Van M.; Hsiai, Tzung K.; Roper, Marcus

2017-01-01

In animals, gas exchange between blood and tissues occurs in narrow vessels, whose diameter is comparable to that of a red blood cell. Red blood cells must deform to squeeze through these narrow vessels, transiently blocking or occluding the vessels they pass through. Although the dynamics of vessel occlusion have been studied extensively, it remains an open question why microvessels need to be so narrow. We study occlusive dynamics within a model microvascular network: the embryonic zebrafish trunk. We show that pressure feedbacks created when red blood cells enter the finest vessels of the trunk act together to uniformly partition red blood cells through the microvasculature. Using mathematical models as well as direct observation, we show that these occlusive feedbacks are tuned throughout the trunk network to prevent the vessels closest to the heart from short-circuiting the network. Thus occlusion is linked with another open question of microvascular function: how are red blood cells delivered at the same rate to each micro-vessel? Our analysis shows that tuning of occlusive feedbacks increase the total dissipation within the network by a factor of 11, showing that uniformity of flows rather than minimization of transport costs may be prioritized by the microvascular network. PMID:29244812

Mapping the dynamics of brain perfusion using functional ultrasound in a rat model of transient middle cerebral artery occlusion

PubMed Central

Brunner, Clément; Isabel, Clothilde; Martin, Abraham; Dussaux, Clara; Savoye, Anne; Emmrich, Julius; Montaldo, Gabriel; Mas, Jean-Louis; Urban, Alan

2015-01-01

Following middle cerebral artery occlusion, tissue outcome ranges from normal to infarcted depending on depth and duration of hypoperfusion as well as occurrence and efficiency of reperfusion. However, the precise time course of these changes in relation to tissue and behavioral outcome remains unsettled. To address these issues, a three-dimensional wide field-of-view and real-time quantitative functional imaging technique able to map perfusion in the rodent brain would be desirable. Here, we applied functional ultrasound imaging, a novel approach to map relative cerebral blood volume without contrast agent, in a rat model of brief proximal transient middle cerebral artery occlusion to assess perfusion in penetrating arterioles and venules acutely and over six days thanks to a thinned-skull preparation. Functional ultrasound imaging efficiently mapped the acute changes in relative cerebral blood volume during occlusion and following reperfusion with high spatial resolution (100 µm), notably documenting marked focal decreases during occlusion, and was able to chart the fine dynamics of tissue reperfusion (rate: one frame/5 s) in the individual rat. No behavioral and only mild post-mortem immunofluorescence changes were observed. Our study suggests functional ultrasound is a particularly well-adapted imaging technique to study cerebral perfusion in acute experimental stroke longitudinally from the hyper-acute up to the chronic stage in the same subject. PMID:26721392

Voxel-Space Ambient Occlusion

DTIC Science & Technology

2012-02-01

a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. a...represents the BRDF of the surface material, for incoming direction ψ and an outgoing direction. L(y) is the incoming radiance in the direction ψ from a...10-1-0338). Models come from the Stanford repository. References [BS09] L. Bavoil, M.Sainz Multi-layer dual-resolution screen-space ambient occlusion

Intermittent fasting is neuroprotective in focal cerebral ischemia by minimizing autophagic flux disturbance and inhibiting apoptosis.

PubMed

Jeong, Ji Heun; Yu, Kwang Sik; Bak, Dong Ho; Lee, Je Hun; Lee, Nam Seob; Jeong, Young Gil; Kim, Dong Kwan; Kim, Jwa-Jin; Han, Seung-Yun

2016-11-01

Previous studies have demonstrated that autophagy induced by caloric restriction (CR) is neuroprotective against cerebral ischemia. However, it has not been determined whether intermittent fasting (IF), a variation of CR, can exert autophagy-related neuroprotection against cerebral ischemia. Therefore, the neuroprotective effect of IF was evaluated over the course of two weeks in a rat model of focal cerebral ischemia, which was induced by middle cerebral artery occlusion and reperfusion (MCAO/R). Specifically, the role of autophagy modulation as a potential underlying mechanism for this phenomenon was investigated. It was demonstrated that IF reduced infarct volume and brain edema, improved neurobehavioral deficits, and rescued neuronal loss after MCAO/R. Furthermore, neuronal apoptosis was decreased by IF in the rat cortex. An increase in the number of autophagosomes (APs) was demonstrated in the cortices of IF-treated rats, using immunofluorescence staining and transmission electron microscopy. Using immunoblots, an IF-induced increase was detected in microtubule-associated protein 1 light chain 3 (LC3)-II, Rab7, and cathepsin D protein levels, which corroborated previous morphological studies. Notably, IF reduced the accumulation of APs and p62, demonstrating that IF attenuated the MCAO/R-induced disturbance of autophagic flux in neurons. The findings of the present study suggest that IF-induced neuroprotection in focal cerebral ischemia is due, at least in part, to the minimization of autophagic flux disturbance and inhibition of apoptosis.

Comparison of occlusal discomfort in patients with temporomandibular disorders between myofascial pain and disc displacement.

PubMed

Shibuya, Toshihisa; Kino, Koji; Sugisaki, Masashi; Sato, Fumiaki; Haketa, Tadasu; Nishiyama, Akira; Takaoka, Michiko; Ota, Takenobu; Ishikawa, Takayuki; Narita, Noriyuki

2009-12-01

We compared occlusal discomfort in patients with temporomandibular disorders (TMD) between myofascial pain (MFP) and disc displacement (DD) using a database created from Sep, 2003 to Aug, 2005. We selected 71 patients with MFP and 170 patients with DD to construct a null model of structural equation modeling (SEM) in which anxiety influenced depressive mood, depressive mood aggravated occlusal discomfort and sleep complaints, and sleep complaints or an onset event caused by another person aggravated occlusal discomfort. We performed a simultaneous analysis of patients with MFP and DD. The estimated parameter of the path from depressive mood to occlusal discomfort was significant for patients with MFP, but not for patients with DD. The path from an onset event caused by another person, such as dental treatment to occlusal discomfort was significant in patients with MFP and those with DD. The Goodness of Fit Index (=0.909), The Adjusted Goodness of Fit Index (=0.867), and The Root Mean Square Error of Approximation (=0.039) indicated good acceptability. These results suggested that an increase in depressive mood may aggravate occlusal discomfort in patients with MFP, and an onset event caused by another person, such as dental treatment, also may aggravate occlusal discomfort in patients with MFP and those with DD.

Influence of the fast-processing technique on the number of the occlusal contacts and occlusal vertical dimension of complete dentures.

PubMed

Atashrazm, Parsa; Alavijeh, Leila Zamani; Afshar, Maryam Sadat Sadrzadeh

2011-03-01

Occlusal errors during acryl processing affect the retention and stability of complete dentures. The aim of the present study was to assess the influence of a short curing technique on the number of occlusal contacts and the occlusal vertical dimension (OVD) of complete dentures. Complete dentures were prepared. The number of occlusal contacts was recorded in centric relation (CR) using 60 µ articulation paper. The OVD was recorded with the waxed trial denture in place. Dentures were then invested and processed with compression molding and short cure water bath technique. The number of occlusal contacts was recorded again. The amount of pin opening was measured for all of the complete dentures on the articulator. Data were analyzed with paired t-test to determine the alterations. The mean number of occlusal contacts before and after processing was 10.9 ± 2.4 and 6.3 ± 3.1 respectively (4.7 ± 1.9 decrease; p < 0.001). A 2 mm mean increase in OVD was observed in 47.7% of the dentures with < 6 occlusal contact changes and 88.9% of the dentures with ≥ 6 occlusal contact changes (p < 0.003). A significant change in the number of occlusal contacts was associated with an OVD increased up to two times. The short curing technique seems to be related to the decreased occlusal contacts and increased OVD. CLINICAL SIGNIFICANCES: More time is needed to adjust the occlusal errors of this method, because it has a negative effect on the morphologic pattern of artificial teeth of complete dentures and thus should be used carefully.

An Automatic Occlusion Device for Remote Control of Tumor Tissue Ischemia

PubMed Central

El-Dahdah, Hamid; Wang, Bei; He, Guanglong; Xu, Ronald X.

2015-01-01

We developed an automatic occlusion device for remote control of tumor tissue ischemia. The device consists of a flexible cannula encasing a shape memory alloy wire with its distal end connected to surgical suture. Regional tissue occlusion was tested on both the benchtop and the animal models. In the benchtop test, the occlusion device introduced quantitative and reproducible changes of blood flow in a tissue simulating phantom embedding a vessel simulator. In the animal test, the device generated a cyclic pattern of reversible ischemia in the right hinder leg tissue of a black male C57BL/6 mouse. We also developed a multimodal detector that integrates near infrared spectroscopy and electron paramagnetic resonance spectroscopy for continuous monitoring of tumor tissue oxygenation, blood content, and oxygen tension changes. The multimodal detector was tested on a cancer xenograft nude mouse undergoing reversible tumor ischemia. The automatic occlusion device and the multi-modal detector can be potentially integrated for closed-loop feedback control of tumor tissue ischemia. Such an integrated occlusion device may be used in multiple clinical applications such as regional hypoperfusion control in tumor resection surgeries and thermal ablation processes. In addition, the proposed occlusion device can also be used as a research tool to understand tumor oxygen transport and hemodynamic characteristics. PMID:20082532

Synthesis and biological evaluation of pyrrolidine derivatives as novel and potent sodium channel blockers for the treatment of ischemic stroke.

PubMed

Seki, Maki; Tsuruta, Osamu; Tatsumi, Ryo; Soejima, Aki

2013-07-15

A novel series of pyrrolidine derivatives as Na(+) channel blockers was synthesized and evaluated for their inhibitory effects on neuronal Na(+) channels. Structure-activity relationship (SAR) studies of a pyrrolidine analogue 2 led to the discovery of 5e as a potent Na(+) channel blocker with a low inhibitory action against human ether-a-go-go-related gene (hERG) channels. Compound 5e showed remarkably neuroprotective activity in a rat transient middle cerebral artery occlusion (MCAO) model, suggesting that 5e would act as a neuroprotectant for ischemic stroke. Copyright © 2013 Elsevier Ltd. All rights reserved.

Delayed treatment with ADAMTS13 ameliorates cerebral ischemic injury without hemorrhagic complication.

PubMed

Nakano, Takafumi; Irie, Keiichi; Hayakawa, Kazuhide; Sano, Kazunori; Nakamura, Yoshihiko; Tanaka, Masayoshi; Yamashita, Yuta; Satho, Tomomitsu; Fujioka, Masayuki; Muroi, Carl; Matsuo, Koichi; Ishikura, Hiroyasu; Futagami, Kojiro; Mishima, Kenichi

2015-10-22

Tissue plasminogen activator (tPA) is the only approved therapy for acute ischemic stroke. However, delayed tPA treatment increases the risk of cerebral hemorrhage and can result in exacerbation of nerve injury. ADAMTS13, a von Willebrand factor (VWF) cleaving protease, has a protective effect against ischemic brain injury and may reduce bleeding risk by cleaving VWF. We examined whether ADAMTS13 has a longer therapeutic time window in ischemic stroke than tPA in mice subjected to middle cerebral artery occlusion (MCAO). ADAMTS13 (0.1mg/kg) or tPA (10mg/kg) was administered i.v., immediately after reperfusion of after 2-h or 4-h MCAO for comparison of the therapeutic time windows in ischemic stroke. Infarct volume, hemorrhagic volume, plasma high-mobility group box1 (HMGB1) levels and cerebral blood flow were measured 24h after MCAO. Both ADAMTS13 and tPA improved the infarct volume without hemorrhagic complications in 2-h MCAO mice. On the other hand, ADAMTS13 reduced the infarct volume and plasma HMGB1 levels, and improved cerebral blood flow without hemorrhagic complications in 4-h MCAO mice, but tPA was not effective and these animals showed massive intracerebral hemorrhage. These results indicated that ADAMTS13 has a longer therapeutic time window in ischemic stroke than tPA, and ADAMTS13 may be useful as a new therapeutic agent for ischemic stroke. Copyright © 2015 Elsevier B.V. All rights reserved.

Near-infrared diffuse reflectance imaging of infarct core and peri-infarct depolarization in a rat middle cerebral artery occlusion model

NASA Astrophysics Data System (ADS)

Kawauchi, Satoko; Nishidate, Izumi; Nawashiro, Hiroshi; Sato, Shunichi

2014-03-01

To understand the pathophysiology of ischemic stroke, in vivo imaging of the brain tissue viability and related spreading depolarization is crucial. In the infarct core, impairment of energy metabolism causes anoxic depolarization (AD), which considerably increases energy consumption, accelerating irreversible neuronal damage. In the peri-infarct penumbra region, where tissue is still reversible despite limited blood flow, peri-infarct depolarization (PID) occurs, exacerbating energy deficit and hence expanding the infarct area. We previously showed that light-scattering signal, which is sensitive to cellular/subcellular structural integrity, was correlated with AD and brain tissue viability in a rat hypoxia-reoxygenation model. In the present study, we performed transcranial NIR diffuse reflectance imaging of the rat brain during middle cerebral artery (MCA) occlusion and examined whether the infarct core and PIDs can be detected. Immediately after occluding the left MCA, light scattering started to increase focally in the occlusion site and a bright region was generated near the occlusion site and spread over the left entire cortex, which was followed by a dark region, showing the occurrence of PID. The PID was generated repetitively and the number of times of occurrence in a rat ranged from four to ten within 1 hour after occlusion (n=4). The scattering increase in the occlusion site was irreversible and the area with increased scattering expanded with increasing the number of PIDs, indicating an expansion of the infarct core. These results suggest the usefulness of NIR diffuse reflectance signal to visualize spatiotemporal changes in the infarct area and PIDs.

Preventive Effect of Cashew-Derived Protein Hydrolysate with High Fiber on Cerebral Ischemia

PubMed Central

Thukham-mee, Wipawee; Wannanon, Panakaporn; Tiamkao, Somsak

2017-01-01

This study aimed to determine the protective effect of cashew nut-derived protein hydrolysate with high dietary fiber (AO) in cerebral ischemic rats induced by the occlusion of right middle cerebral artery (Rt.MCAO). Acute toxicity was determined and data showed that LD50 of AO > 5000 mg/kg BW. To determine the cerebroprotective effect of AO, male Wistar rats were orally given AO at doses of 2, 10, and 50 mg/kg for 14 days and subjected to Rt.MCAO. Brain infarction volume, neurological score, spatial memory, serum lipid profiles, and C-reactive protein together with the brain oxidative stress status were assessed. All doses of AO significantly decreased brain infarction in cortex, hippocampus, and striatum together with the decreased oxidative stress status. The improvement of spatial memory and serum C-reactive protein were also observed in MCAO rats which received AO at all doses. In addition, the decreased serum cholesterol, TG, and LDL but increased HDL were observed in MCAO rats which received high dose of AO. Taken all together, AO is the potential protectant against cerebral ischemia. The improvement of oxidative stress, inflammation, and dyslipidemia might play roles in the actions. However, further researches are required to understand the precise underlying mechanism. PMID:29457029

Ferulic acid prevents cerebral ischemic injury-induced reduction of hippocalcin expression.

PubMed

Koh, Phil-Ok

2013-07-01

Intracellular calcium overload is a critical pathophysiological factor in ischemic injury. Hippocalcin is a neuronal calcium sensor protein that buffers intracellular calcium levels and protects cells from apoptotic stimuli. Ferulic acid exerts a neuroprotective effect in cerebral ischemia through its anti-oxidant and anti-inflammation activity. This study investigated whether ferulic acid contributes to hippocalcin expression during cerebral ischemia and glutamate exposure-induced neuronal cell death. Rats were immediately treated with vehicle or ferulic acid (100 mg/kg, i.v.) after middle cerebral artery occlusion (MCAO). Brain tissues were collected 24 h after MCAO and followed by assessment of cerebral infarct. Ferulic acid reduced MCAO-induced infarct regions. A proteomics approach elucidated a decrease in hippocalcin in MCAO-operated animals, ferulic acid attenuates the injury-induced decrease in hippocalcin expression. Reverse transcription-polymerase chain reaction and Western blot analyses confirmed that ferulic acid prevents the injury-induced decrease in hippocalcin. In cultured HT22 hippocampal cells, glutamate exposure increased the intracellular Ca(2+) levels, whereas ferulic acid attenuated this increase. Moreover, ferulic acid attenuated the glutamate toxicity-induced decrease in hippocalcin expression. These findings can suggest the possibility that ferulic acid exerts a neuroprotective effect through modulating hippocalcine expression and regulating intracellular calcium levels. Copyright © 2013 Wiley Periodicals, Inc.

Melatonin Ameliorates Injury and Specific Responses of Ischemic Striatal Neurons in Rats

PubMed Central

Ma, Yuxin; Feng, Qiqi; Ma, Jing; Feng, Zhibo; Zhan, Mali; OuYang, Lisi; Mu, Shuhua; Liu, Bingbing; Jiang, Zhuyi; Jia, Yu; Li, Youlan

2013-01-01

Studies have confirmed that middle cerebral artery occlusion (MCAO) causes striatal injury in which oxidative stress is involved in the pathological mechanism. Increasing evidence suggests that melatonin may have a neuroprotective effect on cerebral ischemic damage. This study aimed to examine the morphological changes of different striatal neuron types and the effect of melatonin on striatal injury by MCAO. The results showed that MCAO induced striatum-related dysfunctions of locomotion, coordination, and cognition, which were remarkably relieved with melatonin treatment. MCAO induced severe striatal neuronal apoptosis and loss, which was significantly decreased with melatonin treatment. Within the outer zone of the infarct, the number of Darpp-32+ projection neurons and the densities of dopamine-receptor-1 (D1)+ and dopamine-receptor-2 (D2)+ fibers were reduced; however, both parvalbumin (Parv)+ and choline acetyltransferase (ChAT)+ interneurons were not significantly decreased in number, and neuropeptide Y (NPY)+ and calretinin (Cr)+ interneurons were even increased. With melatonin treatment, the loss of projection neurons and characteristic responses of interneurons were notably attenuated. The present study demonstrates that the projection neurons are rather vulnerable to ischemic damage, whereas the interneurons display resistance and even hyperplasia against injury. In addition, melatonin alleviates striatal dysfunction, neuronal loss, and morphological transformation of interneurons resulting from cerebral ischemia. PMID:23686363

Usefulness of MRI to Differentiate Between Temporary and Long-Term Coronary Artery Occlusion in a Minimally Invasive Model of Experimental Myocardial Infarction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abegunewardene, Nico, E-mail: nico@uni-mainz.de; Vosseler, Markus; Gori, Tommaso

The surgical technique employed to determine an experimental ischemic damage is a major factor in the subsequent process of myocardial scar development. We set out to establish a minimally invasive porcine model of myocardial infarction using cardiac contrast-enhanced magnetic resonance imaging (ce-MRI) as the basic diagnostic tool. Twenty-seven domestic pigs were randomized to either temporary or permanent occlusion of the left anterior descending artery (LAD). Temporary occlusion was achieved by inflation of a percutaneous balloon in the left anterior descending artery directly beyond the second diagonal branch. Occlusion was maintained for 30 or 45 min, followed by reperfusion. Permanent occlusionmore » was achieved via thrombin injection. Thirteen animals died peri- or postinterventionally due to arrhythmias. Fourteen animals survived the 30-min ischemia (four animals; group 1), the 45-min ischemia (six animals; group 2), or the permanent occlusion (4 animals; group 3). Coronary angiography and ce-MRI were performed 8 weeks after coronary occlusion to document the coronary flow grade and the size of myocardial scar tissue. The LAD was patent in all animals in groups 1 and 2, with normal TIMI flow; in group 3 animals, the LAD was totally occluded. Fibrosis of the left ventricle in group 1 (4.9 {+-} 4.4%; p = 0.008) and group 2 (9.4 {+-} 2.9%; p = 0.05) was significantly lower than in group 3 (14.5 {+-} 3.9%). Wall thickness of the ischemic area was significantly lower in group 3 versus group 1 and group 2 (2.9 {+-} 0.3, 5.9 {+-} 0.7, and 6.1 {+-} 0.7 mm; p = 0.005). The extent of late enhancement of the left ventricle was also significantly higher in group 3 (16.9 {+-} 2.1%) compared to group 1 (5.3 {+-} 5.4%; p = 0.003) and group 2 (9.7 {+-} 3.4%, p = 0.013). In conclusion, the present model of minimally invasive infarction coupled with ce-MRI may represent a useful alternative to the open chest model for studies of myocardial infarction and scar development.« less

Relative contributions of occlusion, maximum bite force, and chewing cycle kinematics to masticatory performance.

PubMed

Lepley, Casey R; Throckmorton, Gaylord S; Ceen, Richard F; Buschang, Peter H

2011-05-01

The purpose of this study was to explore the contributions of occlusion, maximum bite force, and chewing cycle kinematics to masticatory performance. A prospective cross-sectional study was performed on 30 subjects with Class I occlusion. Masticatory performance was measured with the test food Cuttersil (Heraeus Kulzer, South Bend, Ind) and the fractional-sieve technique. Blu-Mousse (Parkell Biomaterials, Farmingdale, NY) bite registrations were used to measure occlusal contact areas. The American Board of Orthodontics occlusal discrepancies were measured on the subjects' dental models. Maximum bite forces were recorded with a custom transducer, and 3-dimensional chewing cycle kinematics were tracked with an opto-electric computer system and Optotrak software (Northern Digital, Waterloo, Ontario, Canada). Masticatory performance was most closely correlated with occlusal contact area, indicating larger contact areas in subjects with better performance. Occlusal contact area and occlusal discrepancies were also related to bite force and chewing cycle kinematics. Maximum bite force was positively related with masticatory performance. Although masticatory performance is related, both directly and indirectly, to a number of morphologic and functional factors, it is most closely related to occlusal factors. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Detecting natural occlusion boundaries using local cues

PubMed Central

DiMattina, Christopher; Fox, Sean A.; Lewicki, Michael S.

2012-01-01

Occlusion boundaries and junctions provide important cues for inferring three-dimensional scene organization from two-dimensional images. Although several investigators in machine vision have developed algorithms for detecting occlusions and other edges in natural images, relatively few psychophysics or neurophysiology studies have investigated what features are used by the visual system to detect natural occlusions. In this study, we addressed this question using a psychophysical experiment where subjects discriminated image patches containing occlusions from patches containing surfaces. Image patches were drawn from a novel occlusion database containing labeled occlusion boundaries and textured surfaces in a variety of natural scenes. Consistent with related previous work, we found that relatively large image patches were needed to attain reliable performance, suggesting that human subjects integrate complex information over a large spatial region to detect natural occlusions. By defining machine observers using a set of previously studied features measured from natural occlusions and surfaces, we demonstrate that simple features defined at the spatial scale of the image patch are insufficient to account for human performance in the task. To define machine observers using a more biologically plausible multiscale feature set, we trained standard linear and neural network classifiers on the rectified outputs of a Gabor filter bank applied to the image patches. We found that simple linear classifiers could not match human performance, while a neural network classifier combining filter information across location and spatial scale compared well. These results demonstrate the importance of combining a variety of cues defined at multiple spatial scales for detecting natural occlusions. PMID:23255731

Investigation of Retinal Morphology Alterations Using Spectral Domain Optical Coherence Tomography in a Mouse Model of Retinal Branch and Central Retinal Vein Occlusion

PubMed Central

Ebneter, Andreas; Agca, Cavit; Dysli, Chantal; Zinkernagel, Martin S.

2015-01-01

Retinal vein occlusion is a leading cause of visual impairment. Experimental models of this condition based on laser photocoagulation of retinal veins have been described and extensively exploited in mammals and larger rodents such as the rat. However, few reports exist on the use of this paradigm in the mouse. The objective of this study was to investigate a model of branch and central retinal vein occlusion in the mouse and characterize in vivo longitudinal retinal morphology alterations using spectral domain optical coherence tomography. Retinal veins were experimentally occluded using laser photocoagulation after intravenous application of Rose Bengal, a photo-activator dye enhancing thrombus formation. Depending on the number of veins occluded, variable amounts of capillary dropout were seen on fluorescein angiography. Vascular endothelial growth factor levels were markedly elevated early and peaked at day one. Retinal thickness measurements with spectral domain optical coherence tomography showed significant swelling (p<0.001) compared to baseline, followed by gradual thinning plateauing two weeks after the experimental intervention (p<0.001). Histological findings at day seven correlated with spectral domain optical coherence tomography imaging. The inner layers were predominantly affected by degeneration with the outer nuclear layer and the photoreceptor outer segments largely preserved. The application of this retinal vein occlusion model in the mouse carries several advantages over its use in other larger species, such as access to a vast range of genetically modified animals. Retinal changes after experimental retinal vein occlusion in this mouse model can be non-invasively quantified by spectral domain optical coherence tomography, and may be used to monitor effects of potential therapeutic interventions. PMID:25775456

The Effects of Different Repetitive Transcranial Magnetic Stimulation (rTMS) Protocols on Cortical Gene Expression in a Rat Model of Cerebral Ischemic-Reperfusion Injury

PubMed Central

Ljubisavljevic, Milos R.; Javid, Asma; Oommen, Joji; Parekh, Khatija; Nagelkerke, Nico; Shehab, Safa; Adrian, Thomas E.

2015-01-01

Although repetitive Transcranial Magnetic Stimulation (rTMS) in treatment of stroke in humans has been explored over the past decade the data remain controversial in terms of optimal stimulation parameters and the mechanisms of rTMS long-term effects. This study aimed to explore the potential of different rTMS protocols to induce changes in gene expression in rat cortices after acute ischemic-reperfusion brain injury. The stroke was induced by middle cerebral artery occlusion (MCAO) with subsequent reperfusion. Changes in the expression of 96 genes were examined using low-density expression arrays after MCAO alone and after MCAO combined with 1Hz, 5Hz, continuous (cTBS) and intermittent (iTBS) theta-burst rTMS. rTMS over the lesioned hemisphere was given for two weeks (with a 2-day pause) in a single daily session and a total of 2400 pulses. MCAO alone induced significant upregulation in the expression of 44 genes and downregulation in 10. Two weeks of iTBS induced significant increase in the expression of 52 genes. There were no downregulated genes. 1Hz and 5Hz had no significant effects on gene expression, while cTBS effects were negligible. Upregulated genes included those involved in angiogenesis, inflammation, injury response and cellular repair, structural remodeling, neuroprotection, neurotransmission and neuronal plasticity. The results show that long-term rTMS in acute ischemic-reperfusion brain injury induces complex changes in gene expression that span multiple pathways, which generally promote the recovery. They also demonstrate that induced changes primarily depend on the rTMS frequency (1Hz and 5Hz vs. iTBS) and pattern (cTBS vs. iTBS). The results further underlines the premise that one of the benefits of rTMS application in stroke may be to prime the brain, enhancing its potential to cope with the injury and to rewire. This could further augment its potential to favorably respond to rehabilitation, and to restore some of the loss functions. PMID

Occlusal adjustment using the bite plate-induced occlusal position as a reference position for temporomandibular disorders: a pilot study

PubMed Central

2010-01-01

Background Many researchers have not accepted the use of occlusal treatments for temporomandibular disorders (TMDs). However, a recent report described a discrepancy between the habitual occlusal position (HOP) and the bite plate-induced occlusal position (BPOP) and discussed the relation of this discrepancy to TMD. Therefore, the treatment outcome of evidence-based occlusal adjustments using the bite plate-induced occlusal position (BPOP) as a muscular reference position should be evaluated in patients with TMD. Methods The BPOP was defined as the position at which a patient voluntarily closed his or her mouth while sitting in an upright posture after wearing an anterior flat bite plate for 5 minutes and then removing the plate. Twenty-one patients with TMDs underwent occlusal adjustment using the BPOP. The occlusal adjustments were continued until bilateral occlusal contacts were obtained in the BPOP. The treatment outcomes were evaluated using the subjective dysfunction index (SDI) and the Helkimo Clinical Dysfunction Index (CDI) before and after the occlusal adjustments; the changes in these two indices between the first examination and a one-year follow-up examination were then analyzed. In addition, the difference between the HOP and the BPOP was three-dimensionally measured before and after the treatment. Results The percentage of symptom-free patients after treatment was 86% according to the SDI and 76% according to the CDI. The changes in the two indices after treatment were significant (p < 0.001). The changes in the mean HOP-BPOP differences on the x-axis (mediolateral) and the y-axis (anteroposterior) were significant (p < 0.05), whereas the change on the z-axis (superoinferior) was not significant (p > 0.1). Conclusion Although the results of the present study should be confirmed in other studies, a randomized clinical trial examining occlusal adjustments using the BPOP as a reference position appears to be warranted. PMID:20346167

Transplanted Dental Pulp Stem Cells Migrate to Injured Area and Express Neural Markers in a Rat Model of Cerebral Ischemia.

PubMed

Zhang, Xuemei; Zhou, Yinglian; Li, Hulun; Wang, Rui; Yang, Dan; Li, Bing; Cao, Xiaofang; Fu, Jin

2018-01-01

Ischemic stroke is a major cause of disability and mortality worldwide, while effective restorative treatments are limited at present. Stem cell transplantation holds therapeutic potential for ischemic vascular diseases and may provide an opportunity for neural regeneration. Dental pulp stem cells (DPSCs) origin from neural crest and have neuro-ectodermal features including proliferation and multilineage differentiation potentials. The rat model of middle cerebral artery occlusion (MCAO) was used to evaluate whether intravenous administration of DPSCs can reduce infarct size and to estimate the migration and trans-differentiation into neuron-like cells in focal cerebral ischemia models. Brain tissues were collected at 4 weeks following cell transplantation and analyzed with immunofluorescence, immunohistochemistry and real-time polymerase chain reaction (RT-PCR) methods. Intravenously administration of rat-derived DPSCs were found to migrate into the boundary of ischemic areas and expressed neural specific markers, reducing infarct volume and cerebral edema. These results suggest that DPSCs treatment may serve as a potential therapy for clinical stroke patients in the future. © 2018 The Author(s). Published by S. Karger AG, Basel.

Stent Graft in Managing Juxta-Renal Aortoiliac Occlusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prabhudesai, V., E-mail: v_prabhudesai@hotmail.com; Mitra, K.; West, D. J.

2003-09-15

Endovascular procedures are frequently used as an alternative to surgical bypass in aortic and iliac occlusion. Stents have revolutionized the scope of such endovascular procedures, but there are few reports of stents or stent grafts in occlusive juxta-renal aortic occlusion. We present a case where such occlusion was managed by use of a stent graft with successful outcome.

21 CFR 878.4020 - Occlusive wound dressing.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Occlusive wound dressing. 878.4020 Section 878...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4020 Occlusive wound dressing. (a) Identification. An occlusive wound dressing is a nonresorbable, sterile or non-sterile device...

21 CFR 878.4020 - Occlusive wound dressing.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Occlusive wound dressing. 878.4020 Section 878...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4020 Occlusive wound dressing. (a) Identification. An occlusive wound dressing is a nonresorbable, sterile or non-sterile device...

Acute left main coronary artery occlusion

PubMed Central

Burgazli, K. Mehmet; Bilgin, Mehmet; Soydan, Nedim; Chasan, Ridvan; Erdogan, Ali

2013-01-01

The treatment of an acute left main coronary artery occlusion still poses a challenge. In this case report we present a 50-year-old patient with an acute occlusion of the left main artery. After a successful angioplasty without “stenting” due to the complexity of the stenosis the patient underwent a successful bypass surgery. We discuss the therapeutic options of acute left main occlusion regarding medical, interventional and surgical options. PMID:24353543

A comparative in vitro study investigating the occlusion and mineralization properties of commercial toothpastes in a four-day dentin disc model.

PubMed

Parkinson, Charles R; Willson, Richard J

2011-01-01

The objective of this study was to evaluate the relative level of dentin tubule occlusion and dentin mineralization conferred by a 5% w/w calcium sodium phosphosilicate (45S5)/1450 ppm fluoride toothpaste in comparison to a range of commercial toothpastes reported to occlude dentin tubules. Two separate experiments were employed to (i) determine the level of dentin tubule occlusion, and (ii) explore the change in dentin mineralization conferred by a number of marketed toothpastes and controls, following twice-daily brushing in a longitudinal, acid challenge-based, dentin disc model. In Study I, 192 bovine dentin discs, polished and etched in citric acid to provide a smooth dentin surface with patent tubules, were divided into eight treatment groups and subjected to brushing with one of seven test toothpastes or deionized water over four days. Prior to and between treatments, the dentin samples were stored in saliva. The test products were fluoridated toothpastes containing: calcium sodium phosphosilicate (45S5); strontium acetate; arginine/calcium carbonate; amine fluoride; calcium sulphate/diphosphate; stannous fluoride; casein stabilized amorphous calcium phosphate toothpaste; and a non-occluding negative control, deionized water. At the end of each treatment day (1 though 4), one group of samples was removed for scanning electron microscopy (SEM) analysis and graded on a categorical visual scale to assess the level of dentin tubule occlusion. A subset of samples from Study I was also cross-sectioned and examined using SEM. For the exploratory mineralization study (Study II), 120 dentin specimens were prepared as previously described and divided into four treatment groups consisting of A, C, F, and a tooth sealant varnish (I), and subjected to the treatment regimen described in Study I. The dentin samples were assessed for changes in surface microhardness using an indenter fitted with a Knoop probe and the level of dentin occlusion. In Study I, the 5% w/w calcium

Reproducable Paraplegia by Thoracic Aortic Occlusion in a Murine Model of Spinal Cord Ischemia-reperfusion

PubMed Central

Bell, Marshall T.; Reece, T. Brett; Smith, Phillip D.; Mares, Joshua; Weyant, Michael J.; Cleveland, Joseph C.; Freeman, Kirsten A.; Fullerton, David A.; Puskas, Ferenc

2014-01-01

Background Lower extremity paralysis continues to complicate aortic interventions. The lack of understanding of the underlying pathology has hindered advancements to decrease the occurrence this injury. The current model demonstrates reproducible lower extremity paralysis following thoracic aortic occlusion. Methods Adult male C57BL6 mice were anesthetized with isoflurane. Through a cervicosternal incision the aorta was exposed. The descending thoracic aorta and left subclavian arteries were identified without entrance into pleural space. Skeletonization of these arteries was followed by immediate closure (Sham) or occlusion for 4 min (moderate ischemia) or 8 min (prolonged ischemia). The sternotomy and skin were closed and the mouse was transferred to warming bed for recovery.  Following recovery, functional analysis was obtained at 12 hr intervals until 48 hr. Results Mice that underwent sham surgery showed no observable hind limb deficit. Mice subjected to moderate ischemia for 4 min had minimal functional deficit at 12 hr followed by progression to complete paralysis at 48 hr. Mice subjected to prolonged ischemia had an immediate paralysis with no observable hind-limb movement at any point in the postoperative period. There was no observed intraoperative or post operative mortality. Conclusion Reproducible lower extremity paralysis whether immediate or delayed can be achieved in a murine model. Additionally, by using a median sternotomy and careful dissection, high survival rates, and reproducibility can be achieved. PMID:24637534

Reproducable paraplegia by thoracic aortic occlusion in a murine model of spinal cord ischemia-reperfusion.

PubMed

Bell, Marshall T; Reece, T Brett; Smith, Phillip D; Mares, Joshua; Weyant, Michael J; Cleveland, Joseph C; Freeman, Kirsten A; Fullerton, David A; Puskas, Ferenc

2014-03-03

Lower extremity paralysis continues to complicate aortic interventions. The lack of understanding of the underlying pathology has hindered advancements to decrease the occurrence this injury. The current model demonstrates reproducible lower extremity paralysis following thoracic aortic occlusion. Adult male C57BL6 mice were anesthetized with isoflurane. Through a cervicosternal incision the aorta was exposed. The descending thoracic aorta and left subclavian arteries were identified without entrance into pleural space. Skeletonization of these arteries was followed by immediate closure (Sham) or occlusion for 4 min (moderate ischemia) or 8 min (prolonged ischemia). The sternotomy and skin were closed and the mouse was transferred to warming bed for recovery. Following recovery, functional analysis was obtained at 12 hr intervals until 48 hr. Mice that underwent sham surgery showed no observable hind limb deficit. Mice subjected to moderate ischemia for 4 min had minimal functional deficit at 12 hr followed by progression to complete paralysis at 48 hr. Mice subjected to prolonged ischemia had an immediate paralysis with no observable hind-limb movement at any point in the postoperative period. There was no observed intraoperative or post operative mortality. Reproducible lower extremity paralysis whether immediate or delayed can be achieved in a murine model. Additionally, by using a median sternotomy and careful dissection, high survival rates, and reproducibility can be achieved.

Neuromuscular dentistry: Occlusal diseases and posture.

PubMed

Khan, Mohd Toseef; Verma, Sanjeev Kumar; Maheshwari, Sandhya; Zahid, Syed Naved; Chaudhary, Prabhat K

2013-01-01

Neuromuscular dentistry has been a controversial topic in the field of dentistry and still remains debatable. The issue of good occlusion and sound health has been repeatedly discussed. Sometimes we get complains of sensitive teeth and sometimes of tired facial muscles on getting up in the morning. Owing to the intimate relation of masticatory apparatus with the cranium and cervico-scapular muscular system, the disorders in any system, draw attention from concerned clinicians involved in management, to develop an integrated treatment protocol for the suffering patients. There may be patients reporting to the dental clinics after an occlusal restoration or extraction, having pain in or around the temporomandibular joint, headache or neck pain. Although their esthetic demands must not be undermined during the course of treatment plan, whenever dental treatment of any sort is planned, occlusion/bite should be given prime importance. Very few dentist are able to diagnose the occlusal disease and of those who diagnose many people resort to aggressive treatment modalities. This paper aims to report the signs of occlusal disease, and discuss their association with TMDs and posture.

Irisin Peptide Protects Brain Against Ischemic Injury Through Reducing Apoptosis and Enhancing BDNF in a Rodent Model of Stroke.

PubMed

Asadi, Yasin; Gorjipour, Fazel; Behrouzifar, Sedigheh; Vakili, Abedin

2018-06-07

Evidence has shown therapeutic potential of irisin in cerebral stroke. The present study aimed to assess the effects of recombinant irisin on the infarct size, neurological outcomes, blood-brain barrier (BBB) permeability, apoptosis and brain-derived neurotrophic factor (BDNF) expression in a mouse model of stroke. Transient focal cerebral ischemia was established by middle cerebral artery occlusion (MCAO) for 45 min and followed reperfusion for 23 h in mice. Recombinant irisin was administrated at doses of 0.1, 0.5, 2.5, 7.5, and 15 µg/kg, intracerebroventricularly (ICV), on the MCAO beginning. Neurological outcomes, infarct size, brain edema and BBB permeability were evaluated by modified neurological severity score (mNSS), 2,3,5-triphenyltetrazolium chloride (TTC) staining and Evans blue (EB) extravasation methods, respectively, at 24 h after ischemia. Apoptotic cells and BDNF protein were detected by TUNEL assay and immunohistochemistry techniques. The levels of Bcl-2, Bax and caspase-3 proteins were measured by immunoblotting technique. ICV irisin administration at doses of 0.5, 2.5, 7.5 and 15 µg/kg, significantly reduced infarct size, whereas only in 7.5 and 15 µg/kg improved neurological outcome (P < 0.001). Treatment with irisin (7.5 µg/kg) reduced brain edema (P < 0.001) without changing BBB permeability (P > 0.05). Additionally, irisin (7.5 µg/kg) significantly diminished apoptotic cells and increased BDNF immunoreactivity in the ischemic brain cortex (P < 0.004). Irisin administration significantly downregulated the Bax and caspase-3 expression and upregulated the Bcl-2 protein. The present study indicated that irisin attenuates brain damage via reducing apoptosis and increasing BDNF protein of brain cortex in the experimental model of stroke in mice.

Adult responses to an ischemic stroke in a rat model of neonatal stress and morphine treatment.

PubMed

Hays, Sarah L; Valieva, Olga A; McPherson, Ronald J; Juul, Sandra E; Gleason, Christine A

2013-02-01

Critically ill newborn infants experience stressors that may alter brain development. Using a rodent model, we previously showed that neonatal stress, morphine, and stress plus morphine treatments each influence early gene expression and may impair neurodevelopment and learning behavior. We hypothesized that the combination of neonatal stress with morphine may alter neonatal angiogenesis and/or adult cerebral blood vessel density and thus increase injury after cerebral ischemia in adulthood. To test this, neonatal Lewis rats underwent 8 h/d maternal separation, plus morning/afternoon hypoxia exposure and either saline or morphine treatment (2 mg/kg s.c.) from postnatal day 3-7. A subset received bromodeoxyuridine to track angiogenesis. Adult brains were stained with collagen IV to quantify cerebral blood vessel density. To examine vulnerability to brain injury, postnatal day 80 adult rats underwent right middle cerebral artery occlusion (MCAO) to produce unilateral ischemic lesions. Brains were removed and processed for histology 48 h after injury. Brain injury was assessed by histological evaluation of hematoxylin and eosin, and silver staining. In contrast to our hypothesis, neither neonatal morphine, stress, nor the combination affected cerebral vessel density or MCAO-induced brain injury. Neonatal angiogenesis was not detected in adult rats possibly due to turnover of endothelial cells. Although unrelated to angiogenesis, hippocampal granule cell neurogenesis was detected and there was a trend (P = 0.073) toward increased bromodeoxyuridine incorporation in rats that underwent neonatal stress. These findings are discussed in contrast to other data concerning the effects of morphine on cerebrovascular function, and acute effects of morphine on hippocampal neurogenesis. Copyright © 2012 ISDN. Published by Elsevier Ltd. All rights reserved.

Neuroprotective effect of agmatine in rats with transient cerebral ischemia using MR imaging and histopathologic evaluation.

PubMed

Huang, Y C; Tzeng, W S; Wang, C C; Cheng, B C; Chang, Y K; Chen, H H; Lin, P C; Huang, T Y; Chuang, T J; Lin, J W; Chang, C P

2013-09-01

This study aimed to further investigate the effects of agmatine on brain edema in the rats with middle cerebral artery occlusion (MCAO) injury using magnetic resonance imaging (MRI) monitoring and biochemical and histopathologic evaluation. Following surgical induction of MCAO for 90min, agmatine was injected 5min after beginning of reperfusion and again once daily for the next 3 post-operative days. The events during ischemia and reperfusion were investigated by T2-weighted images (T2WI), serial diffusion-weighted images (DWI), calculated apparent diffusion coefficient (ADC) maps and contrast-enhanced T1-weighted images (CE-T1WI) during 3h-72h in a 1.5T Siemens MAGNETON Avanto Scanner. Lesion volumes were analyzed in a blinded and randomized manner. Triphenyltetrazolium chloride (TTC), Nissl, and Evans Blue stainings were performed at the corresponding sections. Increased lesion volumes derived from T2WI, DWI, ADC, CE-T1WI, and TTC all were noted at 3h and peaked at 24h-48h after MCAO injury. TTC-derived infarct volumes were not significantly different from the T2WI, DWI-, and CE-T1WI-derived lesion volumes at the last imaging time (72h) point except for significantly smaller ADC lesions in the MCAO model (P<0.05). Volumetric calculation based on TTC-derived infarct also correlated significantly stronger to volumetric calculation based on last imaging time point derived on T2WI, DWI or CE-T1WI than ADC (P<0.05). At the last imaging time point, a significant increase in Evans Blue extravasation and a significant decrease in Nissl-positive cells numbers were noted in the vehicle-treated MCAO injured animals. The lesion volumes derived from T2WI, DWI, CE-T1WI, and Evans blue extravasation as well as the reduced numbers of Nissl-positive cells were all significantly attenuated in the agmatine-treated rats compared with the control ischemia rats (P<0.05). Our results suggest that agmatine has neuroprotective effects against brain edema on a reperfusion model after

Prodigiosin inhibits gp91{sup phox} and iNOS expression to protect mice against the oxidative/nitrosative brain injury induced by hypoxia-ischemia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Chia-Che; Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan; Agricultural Biotechnology Center, National Chung-Hsing University, Taichung, Taiwan

2011-11-15

This study aimed to explore the mechanisms by which prodigiosin protects against hypoxia-induced oxidative/nitrosative brain injury induced by middle cerebral artery occlusion/reperfusion (MCAo/r) injury in mice. Hypoxia in vitro was modeled using oxygen-glucose deprivation (OGD) followed by reoxygenation of BV-2 microglial cells. Our results showed that treatment of mice that have undergone MCAo/r injury with prodigiosin (10 and 100 {mu}g/kg, i.v.) at 1 h after hypoxia ameliorated MCAo/r-induced oxidative/nitrosative stress, brain infarction, and neurological deficits in the mice, and enhanced their survival rate. MCAo/r induced a remarkable production in the mouse brains of reactive oxygen species (ROS) and a significantmore » increase in protein nitrosylation; this primarily resulted from enhanced expression of NADPH oxidase 2 (gp91{sup phox}), inducible nitric oxide synthase (iNOS), and the infiltration of CD11b leukocytes due to breakdown of blood-brain barrier (BBB) by activation of nuclear factor-kappa B (NF-{kappa}B). All these changes were significantly diminished by prodigiosin. In BV-2 cells, OGD induced ROS and nitric oxide production by up-regulating gp91{sup phox} and iNOS via activation of the NF-{kappa}B pathway, and these changes were suppressed by prodigiosin. In conclusion, our results indicate that prodigiosin reduces gp91{sup phox} and iNOS expression possibly by impairing NF-{kappa}B activation. This compromises the activation of microglial and/or inflammatory cells, which then, in turn, mediates prodigiosin's protective effect in the MCAo/r mice. -- Highlights: Black-Right-Pointing-Pointer Prodigiosin ameliorated brain infarction and deficits. Black-Right-Pointing-Pointer Prodigiosin protected against hypoxia/reperfusion-induced brain injury. Black-Right-Pointing-Pointer Prodigiosin diminished oxidative/nitrosativestress and leukocytes infiltration. Black-Right-Pointing-Pointer Prodigiosin reduced BBB breakdown. Black

Normobaric hyperoxia retards the evolution of ischemic brain tissue toward infarction in a rat model of transient focal cerebral ischemia.

PubMed

Xu, Ji; Zhang, Yuan; Liang, Zhouyuan; Wang, Ting; Li, Weiping; Ren, Lijie; Huang, Shaonong; Liu, Wenlan

2016-01-01

Oxygen therapy has been long considered a logical therapy for ischemic stroke. Our previous studies showed that normobaric hyperoxia (normobaric hyperoxia (NBO), 95% O2 with 5% CO2) treatment during ischemia reduced ischemic neuronal death and cerebromicrovascular injury in animal stroke models. In this study, we studied the effects of NBO on the evolution of ischemic brain tissue to infarction in a rat model of transient focal cerebral ischemia. Male Sprague-Dawley rats were given NBO (95% O2) or normoxia (21% O2) during 90-min filament occlusion of the middle cerebral artery (MCAO), followed by 3 or 22.5 h of reperfusion. 2,3,5-triphenyltetrazolium chloride (TTC) staining was used to evaluate the longitudinal evolution of tissue infarction. Results： In normoxic rats, MCA-supplied cortical and striatal tissue was infarcted after 90-min MCAO with 22.5 h of reperfusion. NBO-treated rats showed a 61.4% reduction in infarct size and tissue infarction mainly occurred in the ischemic striatum. When infarction was assessed at an earlier time point, i.e. at 3 h of reperfusion, normoxic rats showed significantly smaller but mature infarction (no TTC staining, white color), with the infarction mainly occurring in the striatum. Unexpectedly, NBO-treated rats only showed immature lesion (partially stained by TTC, light white color) in the ischemic striatum, indicating that NBO treatment also retarded the process of neuronal death in the ischemic core. Of note, NBO-preserved striatal tissue underwent infarction after prolonged reperfusion. Conclusions： Our results demonstrate that NBO treatment given during cerebral ischemia retards the evolution of ischemic brain tissue toward infarction and NBO-preserved cortical tissue survives better than NBO-preserved striatal tissue during the phase of reperfusion.

Dental occlusion and temporomandibular disorders.

PubMed

Stone, J Caitlin; Hannah, Andrew; Nagar, Nathan

2017-10-27

Data sourcesMedline, Scopus and Google Scholar.Study selectionTwo reviewers selected studies independently. English language clinical studies assessing the association between temporomandibular disorders (TMD) and features of dental occlusion were considered.Data extraction and synthesisStudy quality was assessed based on the Newcastle-Ottawa Scale (NOS) and a narrative synthesis was presented.ResultsIn all 25 studies (17 case-control, eight comparative) were included. Overall there was a high variability between occlusal features and TMD diagnosis. Findings were consistent with a lack of clinically relevant association between TMD and dental occlusion. Only two studies were associated with TMD in the majority (≥50%) of single variable analyses in patient populations. Only mediotrusive interferences are associated with TMD in the majority of multiple variable analyses.ConclusionsThe findings support the absence of a disease-specific association, there is no ground to hypothesise a major role for dental occlusion in the pathophysiology of TMDs. Dental clinicians are thus encouraged to move forward and abandon the old-fashioned gnathological paradig.

Rivaroxaban does not influence hemorrhagic transformation in a diabetes ischemic stroke and endovascular thrombectomy model.

PubMed

Liu, Feng-Di; Zhao, Rong; Feng, Xiao-Yan; Shi, Yan-Hui; Wu, Yi-Lan; Shen, Xiao-Lei; Li, Ge-Fei; Liu, Yi-Sheng; Zhao, Ying; He, Xin-Wei; Yin, Jia-Wen; Zhuang, Mei-Ting; Zhao, Bing-Qiao; Liu, Jian-Ren

2018-05-09

Managing endovascular thrombectomy (ET) in diabetic ischemic stroke (IS) with novel anticoagulants is challenging due to putative risk of intracerebral hemorrhage. The study evaluates increased hemorrhagic transformation (HT) risk in Rivaroxaban-treated diabetic rats post ET. Diabetes was induced in male Sprague-Dawley rats by intraperitoneal injection of 60 mg/kg streptozotocin. After 4-weeks, rats were pretreated orally with 30 mg/kg Rivaroxaban/saline; prothrombin time was monitored. IS and ET was induced after 1 h, by thread-induced transient middle cerebral artery occlusion (tMCAO) that mimicked mechanical ET for proximal MCA occlusion at 60 min. After 24 h reperfusion, infarct volumes, HT, blood-brain barrier (BBB) permeability, tight junction at peri-ischemic lesion and matrix metalloproteinase-9 (MMP-9) activity was measured. Diabetic rats seemed to exhibit increased infarct volume and HT at 24 h after ET than normal rats. Infarct volumes and functional outcomes did not differ between Rivaroxaban and diabetic control groups. A significant increase in HT volumes and BBB permeability under Rivaroxaban treatment was not detected. Compared to diabetic control group, neither the occludin expression was remarkably lower in the Rivaroxaban group nor the MMP-9 activity was higher. Together, Rivaroxaban does not increase HT after ET in diabetic rats with proximal MCA occlusion, since Rivaroxaban has fewer effects on post-ischemic BBB permeability.

Conventional occlusion versus pharmacologic penalization for amblyopia.

PubMed

Li, Tianjing; Shotton, Kate

2009-10-07

Amblyopia is defined as defective visual acuity in one or both eyes without demonstrable abnormality of the visual pathway, and is not immediately resolved by wearing glasses. To assess the effectiveness and safety of conventional occlusion versus atropine penalization for amblyopia. We searched CENTRAL, MEDLINE, EMBASE, LILACS, the WHO International Clinical Trials Registry Platform, preference lists, science citation index and ongoing trials up to June 2009. We included randomized/quasi-randomized controlled trials comparing conventional occlusion to atropine penalization for amblyopia. Two authors independently screened abstracts and full text articles, abstracted data, and assessed the risk of bias. Three trials with a total of 525 amblyopic eyes were included. One trial was assessed as having a low risk of bias among these three trials, and one was assessed as having a high risk of bias.Evidence from three trials suggests atropine penalization is as effective as conventional occlusion. One trial found similar improvement in vision at six and 24 months. At six months, visual acuity in the amblyopic eye improved from baseline 3.16 lines in the occlusion and 2.84 lines in the atropine group (mean difference 0.034 logMAR; 95% confidence interval (CI) 0.005 to 0.064 logMAR). At 24 months, additional improvement was seen in both groups; but there continued to be no meaningful difference (mean difference 0.01 logMAR; 95% CI -0.02 to 0.04 logMAR). The second trial reported atropine to be more effective than occlusion. At six months, visual acuity improved 1.8 lines in the patching group and 3.4 lines in the atropine penalization group, and was in favor of atropine (mean difference -0.16 logMAR; 95% CI -0.23 to -0.09 logMAR). Different occlusion modalities were used in these two trials. The third trial had inherent methodological flaws and limited inference could be drawn.No difference in ocular alignment, stereo acuity and sound eye visual acuity between occlusion and

Necrotizing Fasciitis of the Periorbital Region Complicated by Combined Central Retinal Artery Occlusion, Central Retinal Vein Occlusion, and Posterior Ciliary Occlusion.

PubMed

Sultan, Harris; Malik, Amina; Li, Helen K; Chévez-Barrios, Patricia; Lee, Andrew G

A 50 year-old man on immunosuppressive agents presented with left eye vision loss, periorbital swelling, pain, and ophthalmoplegia. The patient was clinically found to have a central retinal artery and vein occlusion. A CT scan was performed which demonstrated intraorbital fat stranding, however the patient lacked sinus disease. The etiology of the orbital infection was held in question. The area was debrided in the operating room, and the specimen demonstrated group A streptococcal species consistent with necrotizing fasciitis. Periorbital necrotizing fasciitis should be suspected in patients with rapidly progressive orbital symptoms without sinus disease as lack of surgical intervention can result in poor outcomes. The unusual aspect to this case is the mechanism of vision loss, as the authors hypothesize that there was vascular infiltration of the infection resulting in the central retinal artery occlusion and central retinal vein occlusion which have not been previously reported secondary to necrotizing fasciitis of the orbit.

[Evaluation of accuracy of virtual occlusal definition in Angle class I molar relationship].

PubMed

Wu, L; Liu, X J; Li, Z L; Wang, X

2018-02-18

To evaluate the accuracy of virtual occlusal definition in non-Angle class I molar relationship, and to evaluate the clinical feasibility. Twenty pairs of models of orthognathic patients were included in this study. The inclusion criteria were: (1) finished with pre-surgical orthodontic treatment and (2) stable final occlusion. The exclusion criteria were: (1) existence of distorted teeth, (2) needs for segmentation, (3) defect of dentition except for orthodontic extraction ones, and (4) existence of tooth space. The tooth-extracted test group included 10 models with two premolars extracted during preoperative orthodontic treatment. Their molar relationships were not Angle class I relationship. The non-tooth-extracted test group included another 10 models without teeth extracted, therefore their molar relationships were Angle class I. To define the final occlusion in virtual environment, two steps were included: (1) The morphology data of upper and lower dentition were digitalized by surface scanner (Smart Optics/Activity 102; Model-Tray GmbH, Hamburg, Germany); (2) the virtual relationships were defined using 3Shape software. The control standard of final occlusion was manually defined using gypsum models and then digitalized by surface scanner. The final occlusion of test group and control standard were overlapped according to lower dentition morphology. Errors were evaluated by calculating the distance between the corresponding reference points of testing group and control standard locations. The overall errors for upper dentition between test group and control standard location were (0.51±0.18) mm in non-tooth-extracted test group and (0.60±0.36) mm in tooth-extracted test group. The errors were significantly different between these two test groups (P<0.05). However, in both test groups, the errors of each tooth in a single dentition does not differ from one another. There was no significant difference between errors in tooth-extracted test group and 1 mm (P

In vivo THz imaging of human skin: Accounting for occlusion effects.

PubMed

Sun, Qiushuo; Parrott, Edward P J; He, Yuezhi; Pickwell-MacPherson, Emma

2018-02-01

In vivo terahertz (THz) imaging of human skin needs to be done in reflection geometry due to the high attenuation of THz light by water in the skin. To aid the measurement procedure, there is typically an imaging window onto which the patient places the area of interest. The window enables better pulse alignment and helps keep the patient correctly positioned during the measurement. In this paper, we demonstrate how the occlusion caused by the skin contact with the imaging window during the measurement affects the THz response. By studying both rapid point measurements and imaging over an area of a human volar forearm, we find that even 5 seconds of occlusion affects the THz response. As the occlusion time increases, the skin surface water content increases, resulting in the reduction of the amplitude of the reflected THz pulse, especially in the first 3 minutes. Furthermore, it was found that the refractive index of the volar forearm increased by 10% to 15% after 20 minutes of occlusion. In this work, we examine and propose a model for the occlusion effects due to the quartz window with a view to compensating for its influence. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Neuromuscular dentistry: Occlusal diseases and posture

PubMed Central

Khan, Mohd Toseef; Verma, Sanjeev Kumar; Maheshwari, Sandhya; Zahid, Syed Naved; Chaudhary, Prabhat K.

2013-01-01

Neuromuscular dentistry has been a controversial topic in the field of dentistry and still remains debatable. The issue of good occlusion and sound health has been repeatedly discussed. Sometimes we get complains of sensitive teeth and sometimes of tired facial muscles on getting up in the morning. Owing to the intimate relation of masticatory apparatus with the cranium and cervico-scapular muscular system, the disorders in any system, draw attention from concerned clinicians involved in management, to develop an integrated treatment protocol for the suffering patients. There may be patients reporting to the dental clinics after an occlusal restoration or extraction, having pain in or around the temporomandibular joint, headache or neck pain. Although their esthetic demands must not be undermined during the course of treatment plan, whenever dental treatment of any sort is planned, occlusion/bite should be given prime importance. Very few dentist are able to diagnose the occlusal disease and of those who diagnose many people resort to aggressive treatment modalities. This paper aims to report the signs of occlusal disease, and discuss their association with TMDs and posture. PMID:25737904

Glatiramer Acetate administration does not reduce damage after cerebral ischemia in mice.

PubMed

Poittevin, Marine; Deroide, Nicolas; Azibani, Feriel; Delcayre, Claude; Giannesini, Claire; Levy, Bernard I; Pocard, Marc; Kubis, Nathalie

2013-01-15

Inflammation plays a key role in ischemic stroke pathophysiology: microglial/macrophage cells and type-1 helper cells (Th1) seem deleterious, while type-2 helper cells (Th2) and regulatory T cells (Treg) seem protective. CD4 Th0 differentiation is modulated by microglial cytokine secretion. Glatiramer Acetate (GA) is an immunomodulatory drug that has been approved for the treatment of human multiple sclerosis by means of a number of mechanisms: reduced microglial activation and pro-inflammatory cytokine production, Th0 differentiation shifting from Th2 to Th2 and Treg with anti-inflammatory cytokine production and increased neurogenesis. We induced permanent (pMCAo) or transient middle cerebral artery occlusion (tMCAo) and GA (2 mg) or vehicle was injected subcutaneously immediately after cerebral ischemia. Mice were sacrificed at D3 to measure neurological deficit, infarct volume, microglial cell density and qPCR of TNFα and IL-1β (pro-inflammatory microglial cytokines), IFNγ (Th2 cytokine), IL-4 (Th2 cytokine), TGFβ and IL-10 (Treg cytokines), and at D7 to evaluate neurological deficit, infarct volume and neurogenesis assessment. We showed that in GA-treated pMCAo mice, infarct volume, microglial cell density and cytokine secretion were not significantly modified at D3, while neurogenesis was enhanced at D7 without significant infarct volume reduction. In GA-treated tMCAo mice, microglial pro-inflammatory cytokines IL-1β and TNFα were significantly decreased without modification of microglial/macrophage cell density, cytokine secretion, neurological deficit or infarct volume at D3, or modification of neurological deficit, neurogenesis or infarct volume at D7. In conclusion, Glatiramer Acetate administered after cerebral ischemia does not reduce infarct volume or improve neurological deficit in mice despite a significant increase in neurogenesis in pMCAo and a microglial pro-inflammatory cytokine reduction in tMCAo. Copyright © 2012 Elsevier B.V. All rights

Potent sigma 1-receptor ligand 4-phenyl-1-(4-phenylbutyl) piperidine provides ischemic neuroprotection without altering dopamine accumulation in vivo in rats.

PubMed

Goyagi, Toru; Bhardwaj, Anish; Koehler, Raymond C; Traystman, Richard J; Hurn, Patricia D; Kirsch, Jeffrey R

2003-02-01

The in vivo signaling of ischemic neuroprotection provided by sigma-receptor ligands remains unclear. Catecholamines have been implicated in the propagation of ischemic neuronal injury, and previous in vitro studies suggest that sigma ligands modulate dopaminergic neurotransmission. In this study, we tested the hypothesis that the potent sigma(1)-receptor ligand 4-phenyl-1-(4-phenylbutyl) piperidine (PPBP) attenuates the increase of extracellular dopamine in ischemic striatum. Under controlled physiological conditions, a microdialysis probe was implanted in right caudoputamen (CP) complex of adult male Wistar rats. Rats were subjected to 2 h of transient middle cerebral artery occlusion (MCAO) by the intraluminal suture technique. In a blinded, randomized fashion, rats were divided into five treatment groups: Group 1 (n = 8; saline-saline) continuous i.v. infusion of saline vehicle 30 min before MCAO followed by saline at reperfusion until the end of the experiment; Group 2 (n = 8; PPBP-PPBP) i.v. PPBP 30 min before MCAO followed by 1 micromol x kg(-1) x h(-1) of PPBP; Group 3 (n = 8; saline-PPBP) i.v. saline before MCAO followed by PPBP; Group 4 (n = 4) surgical shams (saline-saline); and Group 5 (n = 4) surgical shams (PPBP-PPBP). Infarction volume at 22 h of reperfusion in the CP complex (percentage of ipsilateral structure) was significantly attenuated in rats treated with PPBP-PPBP (27.3% +/- 9.1%) and saline-PPBP (27.8% +/- 12.7%) compared with saline-saline (59.3% +/- 7.3%) treatment. There was a three- to fourfold increase in dopamine concentrations in the microdialysates within 40 min of the onset of MCAO. Dopamine and its metabolites dihydroxy phenylacetic acid and homovallinic acid levels were similar among the three groups subjected to MCAO. Therefore, PPBP provides significant ischemic neuroprotection in the CP complex without altering the acute accumulation of dopamine in vivo during transient focal ischemia in the rat.

Effects of noninvasive facial nerve stimulation in the dog middle cerebral artery occlusion model of ischemic stroke.

PubMed

Borsody, Mark K; Yamada, Chisa; Bielawski, Dawn; Heaton, Tamara; Castro Prado, Fernando; Garcia, Andrea; Azpiroz, Joaquín; Sacristan, Emilio

2014-04-01

Facial nerve stimulation has been proposed as a new treatment of ischemic stroke because autonomic components of the nerve dilate cerebral arteries and increase cerebral blood flow when activated. A noninvasive facial nerve stimulator device based on pulsed magnetic stimulation was tested in a dog middle cerebral artery occlusion model. We used an ischemic stroke dog model involving injection of autologous blood clot into the internal carotid artery that reliably embolizes to the middle cerebral artery. Thirty minutes after middle cerebral artery occlusion, the geniculate ganglion region of the facial nerve was stimulated for 5 minutes. Brain perfusion was measured using gadolinium-enhanced contrast MRI, and ATP and total phosphate levels were measured using 31P spectroscopy. Separately, a dog model of brain hemorrhage involving puncture of the intracranial internal carotid artery served as an initial examination of facial nerve stimulation safety. Facial nerve stimulation caused a significant improvement in perfusion in the hemisphere affected by ischemic stroke and a reduction in ischemic core volume in comparison to sham stimulation control. The ATP/total phosphate ratio showed a large decrease poststroke in the control group versus a normal level in the stimulation group. The same stimulation administered to dogs with brain hemorrhage did not cause hematoma enlargement. These results support the development and evaluation of a noninvasive facial nerve stimulator device as a treatment of ischemic stroke.

Liver size, bodyweight, and tolerance to acute complete occlusion of congenital extrahepatic portosystemic shunts in dogs.

PubMed

Doran, Ivan P; Barr, Frances J; Hotston Moore, Alasdair; Knowles, Toby G; Holt, Peter E

2008-10-01

To investigate the relationship between preoperative liver size, bodyweight, and tolerance to shunt occlusion in dogs with congenital extrahepatic portosystemic shunt(s) (CPSS). Longitudinal cohort study. Dogs with CPSS (n=35). Ultrasonography was used to measure preoperative maximum transverse dimension of the liver (TS) of each dog. Intraoperative portal pressures were measured, before and after CPSS occlusion, via a jejunal vein catheter. Tolerance to shunt occlusion was judged on gross visceral observations, and on changes in portal pressure, central venous and mean arterial pressures. TS was significantly related to bodyweight (P<.05). Mean ratios for TS/bodyweight were calculated for dogs tolerant and intolerant of acute complete shunt occlusion. Dogs tolerant to occlusion had significantly higher TS/bodyweight ratios than dogs intolerant to occlusion (P=.025). Dogs with a TS/bodyweight ratio of >7 were more likely to tolerate CPSS occlusion than dogs with a TS/bodyweight ratio of <5 (P=.036). A model was generated to predict portal pressure rise after shunt occlusion, based on liver dimensions and bodyweight (R=0.668). Intestinal oxygenation did not correlate significantly with tolerance to CPSS occlusion (P=.29). In dogs with CPSS, liver size (relative to bodyweight) is significantly greater (P=.025) in dogs that are tolerant of full ligation than intolerant of occlusion. Preoperative measurement of bodyweight and liver size help indicate the likelihood of tolerance to acute complete occlusion of CPSS in dogs.

[Focal cerebral ischemia in rats with estrogen deficiency and endothelial dysfunction].

PubMed

Litvinov, A A; Volotova, E V; Kurkin, D V; Logvinova, E O; Darmanyan, A P; Tyurenkov, I N

2017-01-01

To assess an effect of ovariectomy (OE) on the cerebral blood flow, endothelium-dependent vasodilation, neurological, cognitive and locomotor deficit as markers of brain damage after focal ischemia in rats. The study was conducted in 48 female Wistar rats. Ovariectomy was performed with ovaries and uterine body extirpation, cerebral ischemia was performed by middle cerebral artery occlusion (MCAO) in rats. To assess brain damage, Combs and Garcia scores, 'open field' test (OFT), 'extrapolatory escape test' (EET), 'passive avoidance test' (PAT), 'beam-walking test' were used. Cerebral blood flow was measured using ultrasonic flowmetry. After 7 days of MCAO, the cerebral blood flow in ovarioectomized animals was reduced by 20% compared to sham-ovariectomized animals. Ovariectomized animals with MCAO showed a three-fold endothelium-dependent vasodilation reduction (the reaction of cerebral vessels to the introduction of acetylcholine and N-L-arginine), indicating the presence of severe endothelial dysfunction. In ovarioectomized animals, the cerebral blood flow was reduced by 34% compared to sham-operated animals. MCAO and OE taken together resulted in more than 2-fold increase in neurological, motor disturbances, 3-fold decrease in motor activity of the animals in the OP test. Focal ischemia in ovarioectomized animals with endothelial dysfunction led to memory decrease by 1/5 fold in PAT and by 2-fold in EET.

The role of "rescue saccades" in tracking objects through occlusions.

PubMed

Zelinsky, Gregory J; Todor, Andrei

2010-12-29

We hypothesize that our ability to track objects through occlusions is mediated by timely assistance from gaze in the form of "rescue saccades"-eye movements to tracked objects that are in danger of being lost due to impending occlusion. Observers tracked 2-4 target sharks (out of 9) for 20 s as they swam through a rendered 3D underwater scene. Targets were either allowed to enter into occlusions (occlusion trials) or not (no occlusion trials). Tracking accuracy with 2-3 targets was ≥ 92% regardless of target occlusion but dropped to 74% on occlusion trials with four targets (no occlusion trials remained accurate; 83%). This pattern was mirrored in the frequency of rescue saccades. Rescue saccades accompanied approximatlely 50% of the Track 2-3 target occlusions, but only 34% of the Track 4 occlusions. Their frequency also decreased with increasing distance between a target and the nearest other object, suggesting that it is the potential for target confusion that summons a rescue saccade, not occlusion itself. These findings provide evidence for a tracking system that monitors for events that might cause track loss (e.g., occlusions) and requests help from the oculomotor system to resolve these momentary crises. As the number of crises increase with the number of targets, some requests for help go unsatisfied, resulting in degraded tracking.

Vascular occlusion with a balloon-expandable stent occluder.

PubMed

Moss, J G; Laborde, J C; Clem, M C; Rivera, F J; Encarnacion, C E; Meyer, K B; Palmaz, J C

1994-05-01

To evaluate the effectiveness of a new vascular occlusion device. The device was created by coating a balloon-expandable stent with a silicone sleeve that tapers to a blind-ended nozzle at its leading end. Once crimp-mounted on an angioplasty balloon catheter, the device is introduced over a guide wire through a small end hole in the nozzle. The device was tested for stability and occlusive ability. No migration was measured over a pulsatile pulse range of 50-300 mm Hg, and mean flow rate in the occluded vessel was reduced from 443 mL/min +/- 99 (standard deviation) to 1.9 mL/min +/- 2.7. Subsequently, 12 arteries were occluded in three dogs, and immediate vascular occlusion was achieved in all vessels. An arteriovenous fistula was created in another six dogs and was successfully occluded with the device. Follow-up arteriography at 3 months demonstrated persistent occlusion with no migration of the device. This new occlusive device offers immediate vascular occlusion with excellent stability.

A New Occlusion Device: Application of the ArtVentive Endoluminal Occlusion System (EOS)—First in Human Clinical Trial

DOE Office of Scientific and Technical Information (OSTI.GOV)

Venbrux, Anthony C., E-mail: avenbrux@mfa.gwu.edu; Rudakov, Leon, E-mail: leonrudakov@artventivemedical.com; Plass, Andre, E-mail: andre.plass@usz.ch

2013-05-24

PurposeThe purpose of this study was to determine the safety and efficacy of a new endoluminal occlusion device, ArtVentive endoluminal occlusion system (EOS), to occlude the spermatic vein in symptomatic males with varicoceles.MethodsThe ArtVentive EOS device has been developed for percutaneous, peripheral occlusion of the peripheral arterial and venous vasculature. The system is comprised of an implantable occlusion device and a delivery catheter. At present, there are two device sizes: (a) size 1 for target vessels ranging between 3.5 and 5.5 mm in diameter, and (b) size 2 for target vessels 5.5–8.5 mm in diameter. The treatment group included six adult males,more » ages 22–34 years. Nine target vessels were occluded. A total of 20 devices were implanted in six subjects.ResultsThe acute occlusion rate at the end of the procedure was 100 % occurring in nine of nine vessels. The spermatic veins of all patients remained occluded on venography at 30 days follow-up. Pain scores related to varicoceles decreased in five of six patients.ConclusionsAlthough we recognize this study is limited, initial experience indicates that the ArtVentive EOS is a safe and effective new device for occlusion of vessels (varicoceles). The device has potential applications in other clinical conditions requiring occlusion of veins or arteries.« less

Occlusal considerations in implant therapy: clinical guidelines with biomechanical rationale.

PubMed

Kim, Yongsik; Oh, Tae-Ju; Misch, Carl E; Wang, Hom-Lay

2005-02-01

Due to lack of the periodontal ligament, osseointegrated implants, unlike natural teeth, react biomechanically in a different fashion to occlusal force. It is therefore believed that dental implants may be more prone to occlusal overloading, which is often regarded as one of the potential causes for peri-implant bone loss and failure of the implant/implant prosthesis. Overloading factors that may negatively influence on implant longevity include large cantilevers, parafunctions, improper occlusal designs, and premature contacts. Hence, it is important to control implant occlusion within physiologic limit and thus provide optimal implant load to ensure a long-term implant success. The purposes of this paper are to discuss the importance of implant occlusion for implant longevity and to provide clinical guidelines of optimal implant occlusion and possible solutions managing complications related to implant occlusion. It must be emphasized that currently there is no evidence-based, implant-specific concept of occlusion. Future studies in this area are needed to clarify the relationship between occlusion and implant success.

[Effects of introduction of short peptides before carotid artery occlusion on behaviour and caspase-3 activity in the brain of old rats].

PubMed

Mendzheritskiĭ, A M; Karantysh, G V; Ivonina, K O

2011-01-01

The comparative research of effect of Pinealon and Cortexin on behavior and activity of caspase-3 in a brain of old rats in a model of carotid arteries occlusion was conducted. It is shown that introduction of short peptides promotes a survival rate of the animals that have modeled occlusion of carotid arteries. Under Pinealon before occlusion of carotid arteries, behavioral dream has been increased and a position-finding behavior, a motivational behavior and a motor performance have been reduced. The rats that were introduced Cortexin before carotid arteries occlusion demonstrated the raise of behavioral dream time. At introduction of Pinealon activity of caspase-3 moderately raises in false-operated animals and in a model of occlusion of carotid arteries.

Partial Resuscitative Endovascular Balloon Occlusion of the Aorta (P-REBOA) in a Pig Model (Sus scrofa) with ongoing Resuscitation

DTIC Science & Technology

2016-01-08

occlusion, regulated flow provided perfusion to capillary beds. Following 70 minutes of partial aortic occlusion, damage control surgery and whole blood ... renal function, and were weaned from aortic occlusion more rapidly. CONCLUSIONS: P-REBOA is capable of limiting exsanguination while providing blood ...resuscitation was performed and all animals were survived to 360 minutes. Animals that tolerated distal flow had decreased levels of lactate, preserved

Neuroprotective Effect of Curcumin Against Cerebral Ischemia-Reperfusion Via Mediating Autophagy and Inflammation.

PubMed

Huang, Lifa; Chen, Chengwei; Zhang, Xin; Li, Xu; Chen, Zupeng; Yang, Chao; Liang, Xiaolong; Zhu, Guochong; Xu, Zhen

2018-01-01

Curcumin, a polyphenolic compound extracted from Curcuma longa, has drawn attention for its effective bioactivities against ischemia-induced injury. This study aimed to evaluate the neuroprotective effect of curcumin and investigate the underlying mechanism that mediates autophagy and inflammation in an animal model of middle cerebral artery occlusion (MCAO) in rats. Curcumin was delivered to Sprague Dawley male rats at a dose of 200 mg/kg curcumin by intraperitoneal injection 30 min after ischemia-reperfusion (I/R). LY294002, a specific inhibitor of the PI3K/Akt/mTOR pathway, as well as anisomycin, an activator of TLR4/p38/MAPK, was administered by ventricle injection 30 min before MCAO. The same volume of saline was given as a control. Brain infarction and neurological function were determined 24 h post-MCAO. Immunoblotting and immunofluorescence were used to detect alterations in autophagy-relevant proteins Akt, p-Akt, mTOR, p-mTOR, LC3-II, and LC3-I, and inflammation-related proteins TLR4, p-38, p-p38, and IL-1 in the ipsilateral hemisphere. Cerebral I/R injury resulted in significant alterations of LC3-II/LC3-I, IL-1, TLR4, and p-p38. Curcumin in MCAO rats significantly improved brain damage and neurological function by upregulating p-Akt and p-mTOR and downregulating LC3-II/LC3-I, IL-1, TLR4, p-38, and p-p38. However, these protective effects against ischemia could be suppressed when LY294002 or anisomycin was included. Curcumin exerts neuroprotective effects by attenuating autophagic activities through mediating the PI3K/Akt/mTOR pathway, while also suppressing an inflammatory reaction by regulating the TLR4/p38/MAPK pathway. Furthermore, this study indicates that curcumin could be an effective therapy for patients afflicted with ischemia.

Preconditioning with the traditional Chinese medicine Huang-Lian-Jie-Du-Tang initiates HIF-1α-dependent neuroprotection against cerebral ischemia in rats.

PubMed

Zhang, Qichun; Bian, Huimin; Li, Yu; Guo, Liwei; Tang, Yuping; Zhu, Huaxu

2014-06-11

Huang-Lian-Jie-Du-Tang (HLJDT) is a classical heat-clearing and detoxicating formula of traditional Chinese medicine that is widely used to treat stroke. The present study was designed to investigate the effects of HLJDT preconditioning on neurons under oxygen and glucose deprivation (OGD) and rats subjected to middle cerebral artery occlusion (MCAO). A stroke model of rats was obtained through MCAO. Following HLJDT preconditioning, the cerebral infarction volume, cerebral water content, and neurological deficient score were determined. Cerebral cortical neurons cultured in vitro were preconditioned with HLJDT and then subjected to OGD treatment. The release of lactate dehydrogenase (LDH) from neurons was detected. The levels of hypoxia-inducible factor-1α (HIF-1α) and PI3K/Akt signaling were analyzed by western blotting, and the levels of erythropoietin (EPO) and vascular endothelial growth factor (VEGF) in the supernatant of the neurons and the plasma of MCAO rats were measured through a radioimmunological assay. The apoptosis and proliferation of neurons were analyzed by immunohistochemistry. HLJDT preconditioning significantly reduced the cerebral infarction volume and cerebral water content and ameliorated the neurological deficient score of MCAO rats. In addition, HLJDT preconditioning protected neurons against OGD. Increased HIF-1α, EPO, and VEGF levels and the activation of PI3K/Akt signaling were observed as a result of HLJDT preconditioning. Furthermore, HLJDT preconditioning was found to inhibit ischemia-induced neuron apoptosis and to promote neuron proliferation under conditions of ischemia/reperfusion. Both rats and neurons subjected to HLJDT preconditioning were able to resist ischemia/reperfusion or hypoxia injury through the inhibition of apoptosis and the enhancement of proliferation, and these effects were primarily dependent on the activation of the PI3K/Akt signaling pathway and HIF-1α. Copyright © 2014 Elsevier Ireland Ltd. All rights

[Study of neuron-protective effect and mechanism of neuregulin1β against cerebral ischemia reperfusion-induced injury in rats].

PubMed

Ji, Y Q; Zhang, R; Teng, L; Li, H Y; Guo, Y L

2017-07-18

Objective: Thecurrent study is to explore the neuron-protective mechanism of neuregulin1β (NRG1β) in a rat model of middle cerebral artery occlusion/reperfusion (MCAO/R) through inhibiting the c-Jun phosphorylation. Methods: After 24 h of MCAO/R (referring to Longa's method), neurobehavioral function was measured by modified neurological severity score (mNSS) test; the cerebral infarction volume was detected by triphenyltetrazolium chloride (TTC) staining; the blood brain barrier (BBB) permeability was measured by Evans Blue (EB); the neuron morphology of brain tissue was observed by Nissl stain; the ultra-structures of the neurons were observed by transmission electron microscopy (TEM); the apoptotic neurons were counted by in situ cell death detection kit colocalized with NeuN; the expressions of phospho-c-Jun was determined by immunofluorescent labeling and Western blot analysis. Results: Compared with the sham-operation rats, the rats receiving MCAO/R showed increased mNSS (9.7±1.2), cerebral infarction volume (41.4±3.0)%, permeability of BBB, deformation of neurons, ischemia-induced apoptosis (0.63±0.04), and enhanced expression of phospho-c-Jun protein (0.90±0.07) (all P <0.05). Our data indicated that NRG1β attenuated neurologic deficits (6.4±0.9), decreased the cerebral infarction volume (10.4±0.5), reduced EB extravasation (1.55±0.13) and the deformation of neurons, protected the ultra-structure of neurons, blocked ischemia-induced apoptosis (0.23±0.02), through down-regulated phospho-c-Jun expression (0.40±0.03) in MCAO/R rats ( P <0.05). Conclusion: NRG1β exerts neuron-protective effects against ischemia reperfusion-induced injury in rats through inhibiting the c-Jun phosphorylation.

Fumarate decreases edema volume and improves functional outcome after experimental stroke.

PubMed

Clausen, Bettina Hjelm; Lundberg, Louise; Yli-Karjanmaa, Minna; Martin, Nellie Anne; Svensson, Martina; Alfsen, Maria Zeiler; Flæng, Simon Bertram; Lyngsø, Kristina; Boza-Serrano, Antonio; Nielsen, Helle H; Hansen, Pernille B; Finsen, Bente; Deierborg, Tomas; Illes, Zsolt; Lambertsen, Kate Lykke

2017-09-01

Oxidative stress and inflammation exacerbate tissue damage in the brain after ischemic stroke. Dimethyl-fumarate (DMF) and its metabolite monomethyl-fumarate (MMF) are known to stimulate anti-oxidant pathways and modulate inflammatory responses. Considering these dual effects of fumarates, we examined the effect of MMF treatment after ischemic stroke in mice. Permanent middle cerebral artery occlusion (pMCAO) was performed using adult, male C57BL/6 mice. Thirty minutes after pMCAO, 20mg/kg MMF was administered intravenously. Outcomes were evaluated 6, 24 and 48h after pMCAO. First, we examined whether a bolus of MMF was capable of changing expression of kelch-like erythroid cell-derived protein with CNC homology-associated protein 1 (Keap1) and nuclear factor erythroid 2-related factor (Nrf)2 in the infarcted brain. Next, we studied the effect of MMF on functional recovery. To explore mechanisms potentially influencing functional changes, we examined infarct volumes, edema formation, the expression of heat shock protein (Hsp)72, hydroxycarboxylic acid receptor 2 (Hcar2), and inducible nitric oxide synthase (iNOS) in the infarcted brain using real-time PCR and Western blotting. Concentrations of a panel of pro- and anti-inflammatory cytokines (IFNγ, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12p70, TNF) were examined in both the infarcted brain tissue and plasma samples 6, 24 and 48h after pMCAO using multiplex electrochemoluminiscence analysis. Administration of MMF increased the protein level of Nrf2 6h after pMCAO, and improved functional outcome at 24 and 48h after pMCAO. MMF treatment did not influence infarct size, however reduced edema volume at both 24 and 48h after pMCAO. MMF treatment resulted in increased Hsp72 expression in the brain 6h after pMCAO. Hcar2 mRNA levels increased significantly 24h after pMCAO, but were not different between saline- and MMF-treated mice. MMF treatment also increased the level of the anti-inflammatory cytokine IL-10 in the

Occlusion issues in early Renaissance art

PubMed Central

Gillam, Barbara

2011-01-01

Early Renaissance painters innovatively attempted to depict realistic three-dimensional scenes. A major problem was to produce the impression of overlap for surfaces that occlude one another in the scene but are adjoined in the picture plane. Much has been written about perspective in art but little about occlusion. Here I examine some of the strategies for depicting occlusion used by early Renaissance painters in relation to ecological considerations and perceptual research. Perceived surface overlap is often achieved by implementing the principle that an occluding surface occludes anything behind it, so that occlusion perception is enhanced by a lack of relationship of occluding contour to occluded contours. Some well-known figure-ground principles are also commonly used to stratify adjoined figures. Global factors that assist this stratification include the placement of figures on a ground plane, a high viewpoint, and figure grouping. Artists of this period seem to have differed on whether to occlude faces and heads, often carefully avoiding doing so. Halos were either eliminated selectively or placed oddly to avoid such occlusions. Finally, I argue that the marked intransitivity in occlusion by architecture in the paintings of Duccio can be related to the issue of perceptual versus cognitive influences on the visual impact of paintings. PMID:23145262

Numerical Simulation of Thrombotic Occlusion in Tortuous Arterioles

PubMed Central

Feng, Zhi-Gang; Cortina, Miguel; Chesnutt, Jennifer KW; Han, Hai-Chao

2017-01-01

Tortuous microvessels alter blood flow and stimulate thrombosis but the physical mechanisms are poorly understood. Both tortuous microvessels and abnormally large platelets are seen in diabetic patients. Thus, the objective of this study was to determine the physical effects of arteriole tortuosity and platelet size on the microscale processes of thrombotic occlusion in microvessels. A new lattice-Boltzmann method-based discrete element model was developed to simulate the fluid flow field with fluid-platelet coupling, platelet interactions, thrombus formation, and thrombotic occlusion in tortuous arterioles. Our results show that vessel tortuosity creates high shear stress zones that activate platelets and stimulate thrombus formation. The growth rate depends on the level of tortuosity and the pressure and flow boundary conditions. Once thrombi began to form, platelet collisions with thrombi and subsequent activations were more important than tortuosity level. Thrombus growth narrowed the channel and reduced the flow rate. Larger platelet size leads to quicker decrease of flow rate due to larger thrombi that occluded the arteriole. This study elucidated the important roles that tortuosity and platelet size play in thrombus formation and occlusion in arterioles. PMID:29327739

Measurement of periapical pressure created by occlusal loading.

PubMed

Dobó-Nagy, C; Fejérdy, P; Angyal, J; Harasztosi, L; Daróczi, L; Beke, D; Wesselink, P R

2003-10-01

To develop an in vitro model in which the pressure in the periapical tissues can be measured during loading. Extracted human maxillary central incisors were embedded in resin blocks that had physical characteristics similar to those of bone and periodontal ligament. Each tooth was loaded with 20, 40, 50, 60, 75, 85, 100, 200, 300 and 450 N vertical forces from the incisal edge of the crown on three consecutive occasions. A minute resistor embedded in the periapical space was used to detect apical pressure changes during occlusal loading. The ratio of apical pressure changes (DeltaP) to the loading force changes (DeltaF) was calculated. The periapical pressure detected was in direct proportion to the loading force. The mean value of DeltaP/DeltaF was 5.994 kPa N-1 (SD = 2.04). Direct proportionality was found between the coronal loading and the apical hydrostatic pressure. The DeltaP/DeltaF ratio determined in this study makes it easier to estimate the apical hydrostatic pressure values during occlusal loading of single-rooted teeth. In this study, the apical pressure generated under occlusal loading was the same magnitude as that estimated with the finite element method.

A Novel Nitinol Spherical Occlusion Device for Liver Cancer

PubMed Central

Hsiao, Hao-Ming; Wang, Yi-Ping; Ko, Chun-Yi; Cheng, Yu-Han; Lee, Han-Yu

2016-01-01

Liver cancer or hepatic cancer is a cancer that originates in the liver. It is formed from either the liver itself or from structures within the liver, including blood vessels or the bile duct. Liver cancer can be a life-threatening condition, but it may be cured if found early. Hepatic artery embolization is one of the treatment options involving the injection of substances to reduce the blood flow to cancer cells in the livers of patients with tumors that cannot be removed by surgery; however, this treatment has some limitations. In this paper, we propose a novel nitinol “spherical occlusion device” concept, the first of its kind in the world. Our proposed spherical occlusion device is able to reduce the blood flow to cancer cells by deploying it in the upstream hepatic artery supplying blood to the liver. Moreover, it could carry multiple chemotherapy or radioactive drugs for delivery directly to the target site. Nitinol alloy was chosen as the device material due to its excellent super-elastic property. Computational models were developed to predict the mechanical response of the device during manufacturing and deployment procedures, as well as its hemodynamic behavior. Simulation results showed that the presence of the spherical occlusion device with 14%–27% metal density deployed at the upstream location of the right hepatic artery had significant occlusion effects, with the average blood flow rate cut down by 30%–50%. A pulsed fiber laser and a series of expansions and heat treatments were developed to make the first prototype of the spherical occlusion device for the demonstration of our novel concept. PMID:28787820

Time to aortic occlusion: It's all about access.

PubMed

Romagnoli, Anna; Teeter, William; Pasley, Jason; Hu, Peter; Hoehn, Melanie; Stein, Deborah; Scalea, Thomas; Brenner, Megan

2017-12-01

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a less invasive method of proximal aortic occlusion compared with resuscitative thoracotomy with aortic cross-clamping (RTACC). This study compared time to aortic occlusion with REBOA and RTACC, both including and excluding time required for common femoral artery (CFA) cannulation. This was a retrospective, single-institution review of REBOA or RTACC performed between February 2013 and January 2016. Time of skin incision to aortic cross-clamp for RTACC, time required for CFA cannulation by percutaneous and open methods, and time from guide-wire insertion to balloon inflation at Zone 1 for REBOA, were obtained from videographic recordings. Eighteen RTACC and 21 REBOAs were performed. Median (Q1, Q3) time from skin incision to aortic cross-clamping was 317 seconds (227, 551 seconds). Median (Q1, Q3) time from start of arterial access to Zone 1 balloon occlusion was 474 seconds (431, 572 seconds) (vs. RTACC, p = 0.01). All REBOA procedures were performed with the same device. The median time to complete CFA cannulation was 247 seconds (range, 164-343 seconds), with no difference between percutaneous or open procedures (p = 0.07). The median (Q1, Q3) time to aortic occlusion in REBOA once arterial access had been established was 245 seconds (179, 295.5 seconds), which was significantly shorter than RTACC (p = 0.003). Once CFA access is achieved, time to aortic occlusion is faster with REBOA. Time to aortic occlusion is less than the time required to cannulate the CFA either by percutaneous or open approaches, emphasizing the importance of accurate and expedient CFA access. Resuscitative endovascular balloon occlusion of the aorta may represent a feasible alternative to thoracotomy for aortic occlusion. Time to aortic occlusion will likely decrease with the advent of newer REBOA technology. The rate-limiting portion of REBOA continues to be obtaining CFA access. Therapeutic, level V.

Predictors of early stent occlusion among plastic biliary stents.

PubMed

Khashab, Mouen A; Kim, Katherine; Hutfless, Susan; Lennon, Anne Marie; Kalloo, Anthony N; Singh, Vikesh K

2012-09-01

A major disadvantage of plastic biliary stents is their short patency rates. The aim of this study was to identify predictors of early stent occlusion among patients receiving conventional plastic biliary stents. Early stent occlusion was defined as worsening cholestatic liver test results of a severity sufficiently significant to warrant ERCP with stent exchange prior to the planned stent exchange, or as symptoms of cholangitis. The association of cumulative stent diameter, demographics, stricture location, procedure indication, Charlson comorbidity index, history of prior early stent occlusion, presence of gallbladder, and performance of sphincteromy with the occurrence of early stent occlusion was studied using logistic regression and multivariate analysis. Our patient cohort comprised 343 patients (mean age 59.3 years) who underwent 561 ERCP procedures with the placement of one or more plastic biliary stents (mean number of stents per procedure 1.2, mean total diameter of stents per procedure 12 Fr). Early stent occlusion occurred in 73 (13 %) procedures. Female gender was protective against early stent occlusion (adjusted OR 0.54, 95 % CI 0.32-0.90, p = 0.02), while hilar stricture location was independently associated with a significantly increased risk of early stent occlusion (adjusted OR 3.41, 95 % CI 1.68-6.90, p = 0.0007). Early occlusion of conventional biliary stents occurred in 13 % of cases. While female gender decreased the risk of early stent occlusion, hilar stricture location was a significant predictor of early stent occlusion. Our results suggest that physicians should consider early elective stent exchange in patients with hilar strictures.

Layperson's preference regarding orientation of the transverse occlusal plane and commissure line from the frontal perspective.

PubMed

Silva, Bruno Pereira; Jiménez-Castellanos, Emilio; Finkel, Sivan; Macias, Inmaculada Redondo; Chu, Stephen J

2017-04-01

Facial asymmetries in features such as lip commissure and interpupillary plane canting have been described as common conditions affecting smile esthetics. When presented with these asymmetries, the clinician must choose the reference line with which to orient the transverse occlusal plane of the planned dental restorations. The purpose of the online survey described in this study was to determine lay preferences regarding the transverse occlusal plane orientation in faces that display a cant of the commissure line viewed from the frontal perspective. From a digitally created symmetrical facial model with the transverse occlusal plane and commissure line parallel to the interpupillary line (horizontal) and a model constructed in a previous study (control), a new facial model was created with 3 degrees of cant of the commissure line. Three digital tooth mountings were designed with different transverse occlusal plane orientations: parallel to the interpupillary line (A), parallel to the commissure line (B), and the mean angulation plane formed between the interpupillary and commissure line (C), resulting in a total of 4 images. All images, including the control, were organized into 6 pairs and evaluated by 247 selected laypersons through an online Web site survey. Each participant was asked to choose the more attractive face from each of the 6 pairs of images. The control image was preferred by 72.9% to 74.5% of the participants compared with the other 3 images, all of which represented a commissure line cant. Among the 3 pairs which represent a commissure line cant, 59.1% to 61.1% preferred a transverse plane of occlusion cant (B and C) compared with a plane of occlusion parallel to the interpupillary, line and 61.1% preferred a plane of occlusion parallel to the commissure line (B) compared with the mean angulation plane (C). Laypeople prefer faces with a commissure line and transverse occlusal plane parallel to the horizontal plane or horizon. When faces present a

Influence of denture adhesives on occlusion and disocclusion times.

PubMed

Abdelnabi, Mohamed Hussein; Swelem, Amal Ali; Al-Dharrab, Ayman A

2016-03-01

The effectiveness of adhesives in enhancing several functional aspects of complete denture performance has been well established. The direct influence of adhesives on occlusal contact simultaneity has not yet been investigated. The purpose of this crossover clinical trial was to evaluate quantitatively the influence of adhesives on occlusal balance by recording timed occlusal contacts; namely occlusion time (OT) and disocclusion time during right (DT-right) and left (DT-left) excursions by using computerized occlusal analysis. A crossover clinical trial was adopted. Assessments were carried out while participants (n=49) wore their dentures first without then with adhesives. Computerized occlusal analysis using the T-Scan III system was conducted to perform baseline computer-guided occlusal adjustment for conventionally fabricated dentures. Retention and stability assessment using the modified Kapur index and recording of OT and DT-right and DT-left values using the T-Scan III were subsequently carried out for all dentures, first without adhesives and then after application of adhesive. All T-Scan procedures were carried out by the same clinician. Wilcoxon signed-rank test was used to analyze the Kapur index scores and occlusal parameters (α=.05). Stability and retention of conventional dentures ranged initially from good to very good. However, adhesive application resulted in significant improvement (P<.001) in stability and retention and a significant decrease in duration of all occlusal parameters (OT [P=.003], DT-right [P=.003], and DT-left [P=.008]). Adhesives significantly decreased OT and DT durations in initially well-fitting complete dentures with fairly well balanced occlusion, and further enhanced denture stability and occlusal contact simultaneity. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Mathematical Model of Cardiovascular and Metabolic Responses to Umbilical Cord Occlusions in Fetal Sheep.

PubMed

Wang, Qiming; Gold, Nathan; Frasch, Martin G; Huang, Huaxiong; Thiriet, Marc; Wang, Xiaogang

2015-12-01

Fetal acidemia during labor is associated with an increased risk of brain injury and lasting neurological deficits. This is in part due to the repetitive occlusions of the umbilical cord (UCO) induced by uterine contractions. Whereas fetal heart rate (FHR) monitoring is widely used clinically, it fails to detect fetal acidemia. Hence, new approaches are needed for early detection of fetal acidemia during labor. We built a mathematical model of the UCO effects on FHR, mean arterial blood pressure (MABP), oxygenation and metabolism. Mimicking fetal experiments, our in silico model reproduces salient features of experimentally observed fetal cardiovascular and metabolic behavior including FHR overshoot, gradual MABP decrease and mixed metabolic and respiratory acidemia during UCO. Combined with statistical analysis, our model provides valuable insight into the labor-like fetal distress and guidance for refining FHR monitoring algorithms to improve detection of fetal acidemia and cardiovascular decompensation.

Load-bearing capacity of various CAD/CAM monolithic molar crowns under recommended occlusal thickness and reduced occlusal thickness conditions

PubMed Central

Choi, Sulki

2017-01-01

PURPOSE The goal of this study was to evaluate the fracture resistances of various monolithic crowns fabricated by computer-aided design and computer-aided manufacturing (CAD/CAM) with different thickness. MATERIALS AND METHODS Test dies were fabricated as mandibular molar forms with occlusal reductions using CAD/CAM. With different occlusal thickness (1.0 or 1.5 mm), a polymer-infiltrated ceramic network (Enamic, EN), and zirconia-reinforced lithium silicate (Suprinity, SU and Celtra-Duo, CD) were used to fabricate molar crowns. Lithium disilicate (e.max CAD, EM) crowns (occlusal: 1.5 mm) were fabricated as control. Seventy crowns (n=10 per group) were bonded to abutments and stored in water for 24 hours. A universal testing machine was used to apply load to crown until fracture. The fractured specimens were examined with a scanning electron microscopy. RESULTS The type of ceramics and the occlusal thickness showed a significant interaction. With a recommended thickness (1.5 mm), the SU revealed the mean load similar to the EM, higher compared with those of the EN and CD. The fracture loads in a reduced thickness (1.0 mm) were similar among the SU, CD, and EN. The mean fracture load of the SU and CD enhanced significantly when the occlusal thickness increased, whereas that of the EN did not. CONCLUSION The fracture loads of monolithic crowns were differently influenced by the changes in occlusal thickness, depending on the type of ceramics. Within the limitations of this study, all the tested crowns withstood the physiological masticatory loads both at the recommended and reduced occlusal thickness. PMID:29279761

Occlusal Classification in Relation to Original Cleft Width in Patients With Unilateral Cleft Lip and Palate.

PubMed

Huang, Andrew H; Patel, Kamlesh B; Maschhoff, Clayton W; Huebener, Donald V; Skolnick, Gary B; Naidoo, Sybill D; Woo, Albert S

2015-09-01

To determine a correlation between the width of the cleft palate measured at the time of lip adhesion, definitive lip repair, and palatoplasty and the subsequent occlusal classification of patients born with unilateral cleft lip and palate. Retrospective, observational study. Referral, urban, children's hospital Participants : Dental models and records of 270 patients were analyzed. None. Angle occlusion classification. The mean age at which occlusal classification was determined was 11 ± 0.3 years. Of the children studies, 84 were diagnosed with Class I or II occlusion, 67 were diagnosed with Class III occlusion, and 119 were lost to follow up or transferred care. Mean cleft widths were significantly larger in subjects with Class III occlusion for all measures at time of lip adhesion and definitive lip repair (P < .02). At time of palatoplasty, cleft widths were significantly greater at the alveolus (P = .025) but not at the midportion of the hard palate (P = .35) or posterior hard palate (P = .10). Cleft widths from the lip through to the posterior hard palate are generally greater in children who are diagnosed with Class III occlusion later in life. Notably, the alveolar cleft width is significantly greater at each time point for patients who went on to develop Class III occlusion. There were no significant differences in cleft widths between patients diagnosed later with Class I and Class II occlusions.

Hemihepatic versus total hepatic inflow occlusion during hepatectomy: a systematic review and meta-analysis.

PubMed

Wang, Hai-Qing; Yang, Jia-Yin; Yan, Lu-Nan

2011-07-14

To evaluate the clinical outcomes of patients undergoing hepatectomy with hemihepatic vascular occlusion (HHO) compared with total hepatic inflow occlusion (THO). Randomized controlled trials (RCTs) comparing hemihepatic vascular occlusion and total hepatic inflow occlusion were included by a systematic literature search. Two authors independently assessed the trials for inclusion and extracted the data. A meta-analysis was conducted to estimate blood loss, transfusion requirement, and liver injury based on the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Either the fixed effects model or random effects model was used. Four RCTs including 338 patients met the predefined inclusion criteria. A total of 167 patients were treated with THO and 171 with HHO. Meta-analysis of AST levels on postoperative day 1 indicated higher levels in the THO group with weighted mean difference (WMD) 342.27; 95% confidence intervals (CI) 217.28-467.26; P = 0.00 001; I(2) = 16%. Meta-analysis showed no significant difference between THO group and HHO group on blood loss, transfusion requirement, mortality, morbidity, operating time, ischemic duration, hospital stay, ALT levels on postoperative day 1, 3 and 7 and AST levels on postoperative day 3 and 7. Hemihepatic vascular occlusion does not offer satisfying benefit to the patients undergoing hepatic resection. However, they have less liver injury after liver resections.

Hemihepatic versus total hepatic inflow occlusion during hepatectomy: A systematic review and meta-analysis

PubMed Central

Wang, Hai-Qing; Yang, Jia-Yin; Yan, Lu-Nan

2011-01-01

AIM: To evaluate the clinical outcomes of patients undergoing hepatectomy with hemihepatic vascular occlusion (HHO) compared with total hepatic inflow occlusion (THO). METHODS: Randomized controlled trials (RCTs) comparing hemihepatic vascular occlusion and total hepatic inflow occlusion were included by a systematic literature search. Two authors independently assessed the trials for inclusion and extracted the data. A meta-analysis was conducted to estimate blood loss, transfusion requirement, and liver injury based on the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Either the fixed effects model or random effects model was used. RESULTS: Four RCTs including 338 patients met the predefined inclusion criteria. A total of 167 patients were treated with THO and 171 with HHO. Meta-analysis of AST levels on postoperative day 1 indicated higher levels in the THO group with weighted mean difference (WMD) 342.27; 95% confidence intervals (CI) 217.28-467.26; P = 0.00 001; I2 = 16%. Meta-analysis showed no significant difference between THO group and HHO group on blood loss, transfusion requirement, mortality, morbidity, operating time, ischemic duration, hospital stay, ALT levels on postoperative day 1, 3 and 7 and AST levels on postoperative day 3 and 7. CONCLUSION: Hemihepatic vascular occlusion does not offer satisfying benefit to the patients undergoing hepatic resection. However, they have less liver injury after liver resections. PMID:21912460

Ovarian blood vessel occlusion as a surgical sterilization method in rats.

PubMed

Murakami, Eduardo; Sartori de Camargo, Laíza; Freitas Cardoso, Karym Christine de; Miguel, Marina Pacheco; Tavares, Denise Cláudia; Santos Honsho, Cristiane dos; Ferreira de Souza, Fabiana

2014-04-01

To evaluate the female sterilization by occlusion of the ovarian blood flow, using the rat as experimental model. Fifty-five females rats were divided into four groups: I (n=10), bilateral ovariectomy, euthanized at 60 or 90 days; II (n=5), opening the abdominal cavity, euthanized at 90 days; III (n=20), bilateral occlusion of the ovarian blood supply using titanium clips, euthanized at 60 or 90 days; and IV (n=20), bilateral occlusion of the ovarian blood supply using nylon thread, euthanized at 60 or 90 days. The estrous cycle was monitored by vaginal cytology. After euthanasia, the reproductive tissues were evaluated histologically. Ovarian atresia was identified macroscopically at 60 days after surgery in the rats in groups III and IV; however, most of the rats in group III maintained cyclicity. Histology of the tissues from group IV revealed that the ovarian tissue was replaced by dense fibrous connective tissue that was slightly vascularized and that intact follicles were absent by 90 days. Ovarian blood vessels occluded caused ischemia, leading to progressive tissue necrosis, and bilateral occlusion using a nylon ligature is a viable method for surgical sterilization.

Multi-scale Visualization of Molecular Architecture Using Real-Time Ambient Occlusion in Sculptor.

PubMed

Wahle, Manuel; Wriggers, Willy

2015-10-01

The modeling of large biomolecular assemblies relies on an efficient rendering of their hierarchical architecture across a wide range of spatial level of detail. We describe a paradigm shift currently under way in computer graphics towards the use of more realistic global illumination models, and we apply the so-called ambient occlusion approach to our open-source multi-scale modeling program, Sculptor. While there are many other higher quality global illumination approaches going all the way up to full GPU-accelerated ray tracing, they do not provide size-specificity of the features they shade. Ambient occlusion is an aspect of global lighting that offers great visual benefits and powerful user customization. By estimating how other molecular shape features affect the reception of light at some surface point, it effectively simulates indirect shadowing. This effect occurs between molecular surfaces that are close to each other, or in pockets such as protein or ligand binding sites. By adding ambient occlusion, large macromolecular systems look much more natural, and the perception of characteristic surface features is strongly enhanced. In this work, we present a real-time implementation of screen space ambient occlusion that delivers realistic cues about tunable spatial scale characteristics of macromolecular architecture. Heretofore, the visualization of large biomolecular systems, comprising e.g. hundreds of thousands of atoms or Mega-Dalton size electron microscopy maps, did not take into account the length scales of interest or the spatial resolution of the data. Our approach has been uniquely customized with shading that is tuned for pockets and cavities of a user-defined size, making it useful for visualizing molecular features at multiple scales of interest. This is a feature that none of the conventional ambient occlusion approaches provide. Actual Sculptor screen shots illustrate how our implementation supports the size-dependent rendering of molecular

Occlusal characteristics of children with hypertrophied adenoids in Nigeria.

PubMed

Osiatuma, Vivien Ijeoma; Otuyemi, Olayinka Donald; Kolawole, Kikelomo Adebanke; Ogunbanjo, Babatunde Ogunbiyi; Amusa, Yemisi Bola

2015-03-01

Nasorespiratory function and its relation to craniofacial growth are of great interest because of the basic biological relationship between form and function, and the accumulating findings of the relationship between mode of breathing, craniofacial growth and orthodontic treatment. The aim of this study was to evaluate the effect of adenoid hypertrophy and sociodemographic variables on the occlusion of children. A total of 180 subjects aged 3-12 years were selected at the Obafemi Awolowo University Teaching Hospital Complex, Ile-Ife, Nigeria. Ninety subjects had hypertrophied adenoids while 90 normal children served as the control group. Orthodontic examinations were carried out and impressions for study models taken. Occlusion was assessed in the anterior-posterior, transverse and vertical planes. Class I relationship was the most prevalent occlusion in both adenoid and control subjects (55.6% and 72.2%, respectively). The occurrence of class II division 1 was significantly higher among adenoid than control subjects (P=0.003). Posterior crossbites occurred significantly more in adenoid subjects in the 9-12 years category. In the vertical plane, the occurrence of deep bite was significantly greater in male than female adenoid subjects. Age had a statistically significant but weak correlation with anterior open bite (r=0.37). Age and BMI also had significant though weak correlations with posterior crossbite in female adenoid subjects (r=0.39 and r=0.36, respectively). Regression analysis also showed that age had a significant effect on the occurrence of anterior open bite, while BMI had a significant effect on the occurrence of class II occlusion in adenoid subjects (P<0.05). The presence of hypertrophied adenoids affects the occlusion in the three planes. Age and BMI have significant effects on the occurrence of anterior open bite and class II division 1 malocclusion respectively in adenoid subjects. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

The TNFα-Transgenic Rat: Hippocampal Synaptic Integrity, Cognition, Function, and Post-Ischemic Cell Loss

PubMed Central

Pettigrew, L. Creed; Kryscio, Richard J.; Norris, Christopher M.

2016-01-01

The cytokine, tumor necrosis factor α (TNFα), is a key regulator of neuroinflammation linked to numerous neurodegenerative conditions and diseases. The present study used transgenic rats that overexpress a murine TNFα gene, under the control of its own promoter, to investigate the impact of chronically elevated TNFα on hippocampal synaptic function. Neuronal viability and cognitive recovery in TNFα Tg rats were also determined following an ischemic insult arising from reversible middle cerebral artery occlusion (MCAO). Basal CA3-CA1 synaptic strength, recorded in acute brain slices, was not significantly different between eight-week-old TNFα Tg rats and non-Tg rats. In contrast, slices from TNFα Tg rats showed significantly greater levels of long-term potentiation (LTP) in response to 100 Hz stimulation, suggesting that synaptic networks may be hyperexcitable in the context of elevated TNFα. Cognitive and motor deficits (assessed on the Morris Water Maze and Rotarod task, respectively) were present in TNFα Tg rats in the absence of significant differences in the loss of cortical and hippocampal neurons. TNF overexpression exacerbated MCAO-dependent deficits on the rotarod, but ameliorated cortical neuron loss in response to MCAO. PMID:27144978

Soluble TNF receptor 1-secreting ex vivo-derived dendritic cells reduce injury after stroke.

PubMed

Works, Melissa G; Koenig, Jenny B; Sapolsky, Robert M

2013-09-01

Inflammation is a major factor in the progression of damage after stroke and in the clinic, current therapies treat the clot, not the resulting damage. We have developed a novel method of protein delivery that exploits the migration ability of leukocytes after ischemic stroke (transient middle cerebral artery occlusion; tMCAO). In our studies, ex vivo-derived dendritic cells (exDCs) migrate to the inflamed rat brain soon after tMCAO onset and the number of cells that remain in the brain after injection is significantly correlated with the amount of local inflammation at the injury site. In addition, exDCs transduced to overexpress soluble tumor necrosis factor (TNF) receptor1 (sTNFR1) produce functional cargo that is secreted and that blocks TNF-α bioavailability in vitro. When delivered at 6 hours post-tMCAO reperfusion, sTNFR1-exDC-treated rats show significantly smaller infarct size and decreased inflammation compared with animals treated with exDCs transduced with GFP lentivirus. These studies indicate that cell-mediated delivery of proteins may be a promising new approach to reduce brain damage after acute neurologic insult.

Robust Lane Sensing and Departure Warning under Shadows and Occlusions

PubMed Central

Tapia-Espinoza, Rodolfo; Torres-Torriti, Miguel

2013-01-01

A prerequisite for any system that enhances drivers' awareness of road conditions and threatening situations is the correct sensing of the road geometry and the vehicle's relative pose with respect to the lane despite shadows and occlusions. In this paper we propose an approach for lane segmentation and tracking that is robust to varying shadows and occlusions. The approach involves color-based clustering, the use of MSAC for outlier removal and curvature estimation, and also the tracking of lane boundaries. Lane boundaries are modeled as planar curves residing in 3D-space using an inverse perspective mapping, instead of the traditional tracking of lanes in the image space, i.e., the segmented lane boundary points are 3D points in a coordinate frame fixed to the vehicle that have a depth component and belong to a plane tangent to the vehicle's wheels, rather than 2D points in the image space without depth information. The measurement noise and disturbances due to vehicle vibrations are reduced using an extended Kalman filter that involves a 6-DOF motion model for the vehicle, as well as measurements about the road's banking and slope angles. Additional contributions of the paper include: (i) the comparison of textural features obtained from a bank of Gabor filters and from a GMRF model; and (ii) the experimental validation of the quadratic and cubic approximations to the clothoid model for the lane boundaries. The results show that the proposed approach performs better than the traditional gradient-based approach under different levels of difficulty caused by shadows and occlusions. PMID:23478598

Splenectomy Fails to Provide Long-Term Protection Against Ischemic Stroke.

PubMed

Ran, Yuanyuan; Liu, Zongjian; Huang, Shuo; Shen, Jiamei; Li, Fengwu; Zhang, Wenxiu; Chen, Chen; Geng, Xiaokun; Ji, Zhili; Du, Huishan; Hu, Xiaoming

2018-06-01

Splenectomy before or immediately after stroke provides early brain protection. This study aims to explore the effect of splenectomy on long-term neurological recovery after stroke, which is currently lacking in the field. Adult male rats were randomized into splenectomy or sham groups and then subjected to 90 min of middle cerebral artery occlusion (MCAO). Spleen was removed right upon reperfusion or 3d after MCAO. Infarct volume, neurological functions, and peripheral immune cell populations were assessed up to 28d after stroke. The results show that delayed removal of spleen did not reduce brain tissue loss and showed no effect on sensorimotor function (Rotarod, beam balance, forelimb placing, grid walk, and adhesive removal tests) or cognitive function (Morris water maze). Spleen removal immediately upon reperfusion, although significantly reduced the infarct size and immune cell infiltration 3d after MCAO, also failed to promote long-term recovery. Flow cytometry analysis demonstrated that immediate splenectomy after MCAO resulted in a prolonged decrease in the percentage of CD3 + CD4 + and CD3 + CD8 + T cells in total lymphocytes as compared to non-splenectomy MCAO rats. In contrast, the percentage of CD3 - CD45RA + B cells was significantly elevated after splenectomy. As a result, the ratio of T/B cells was significantly reduced in stroke rats with splenectomy. In conclusion, delayed splenectomy failed to provide long-term protection to the ischemic brain or improve functional recovery. The acute neuroprotective effect achieved by early splenectomy after stroke cannot last for long term. This loss of neuroprotection might be related to the prolonged disturbance in the T cell to B cell ratio.

Volumetric ambient occlusion for real-time rendering and games.

PubMed

Szirmay-Kalos, L; Umenhoffer, T; Toth, B; Szecsi, L; Sbert, M

2010-01-01

This new algorithm, based on GPUs, can compute ambient occlusion to inexpensively approximate global-illumination effects in real-time systems and games. The first step in deriving this algorithm is to examine how ambient occlusion relates to the physically founded rendering equation. The correspondence stems from a fuzzy membership function that defines what constitutes nearby occlusions. The next step is to develop a method to calculate ambient occlusion in real time without precomputation. The algorithm is based on a novel interpretation of ambient occlusion that measures the relative volume of the visible part of the surface's tangent sphere. The new formula's integrand has low variation and thus can be estimated accurately with a few samples.

Varying face occlusion detection and iterative recovery for face recognition

NASA Astrophysics Data System (ADS)

Wang, Meng; Hu, Zhengping; Sun, Zhe; Zhao, Shuhuan; Sun, Mei

2017-05-01

In most sparse representation methods for face recognition (FR), occlusion problems were usually solved via removing the occlusion part of both query samples and training samples to perform the recognition process. This practice ignores the global feature of facial image and may lead to unsatisfactory results due to the limitation of local features. Considering the aforementioned drawback, we propose a method called varying occlusion detection and iterative recovery for FR. The main contributions of our method are as follows: (1) to detect an accurate occlusion area of facial images, an image processing and intersection-based clustering combination method is used for occlusion FR; (2) according to an accurate occlusion map, the new integrated facial images are recovered iteratively and put into a recognition process; and (3) the effectiveness on recognition accuracy of our method is verified by comparing it with three typical occlusion map detection methods. Experiments show that the proposed method has a highly accurate detection and recovery performance and that it outperforms several similar state-of-the-art methods against partial contiguous occlusion.

Involvement of arterial baroreflex in the protective effect of dietary restriction against stroke

PubMed Central

Liu, Ai-Jun; Guo, Jin-Min; Liu, Wei; Su, Feng-Yun; Zhai, Qi-Wei; Mehta, Jawahar L; Wang, Wei-Zhong; Su, Ding-Feng

2013-01-01

Dietary restriction (DR) protects against neuronal dysfunction and degeneration, and reduces the risk of ischemic stroke. This study examined the role of silent information regulator T1 (SIRT1) and arterial baroreflex in the beneficial effects of DR against stroke, using two distinct stroke models: stroke-prone spontaneously hypertensive rats (SP-SHRs) and Sprague-Dawley (SD) rats with middle cerebral artery occlusion (MCAO). Sirt1 knockout (KO) mice were used to examine the involvement of sirt1. Sinoaortic denervation was used to inactivate arterial baroreflex. Dietary restriction was defined as 40% reduction of dietary intake. Briefly, DR prolonged the life span of SP-SHRs and reduced the infarct size induced by MCAO. Dietary restriction also improved the function arterial baroreflex, decreased the release of proinflammatory cytokines, and reduced end-organ damage. The beneficial effect of DR on stroke was markedly attenuated by blunting arterial baroreflex. Lastly, the infarct area in sirt1 KO mice was significantly larger than in the wild-type mice. However, the beneficial effect of DR against ischemic injury was still apparent in sirt1 KO mice. Accordingly, arterial baroreflex, but not sirt1, is important in the protective effect of DR against stroke. PMID:23443169

Sex differences in ischemic stroke sensitivity are influenced by gonadal hormones, not by sex chromosome complement.

PubMed

Manwani, Bharti; Bentivegna, Kathryn; Benashski, Sharon E; Venna, Venugopal Reddy; Xu, Yan; Arnold, Arthur P; McCullough, Louise D

2015-02-01

Epidemiologic studies have shown sex differences in ischemic stroke. The four core genotype (FCG) mouse model, in which the testes determining gene, Sry, has been moved from Y chromosome to an autosome, was used to dissociate the effects of sex hormones from sex chromosome in ischemic stroke outcome. Middle cerebral artery occlusion (MCAO) in gonad intact FCG mice revealed that gonadal males (XXM and XYM) had significantly higher infarct volumes as compared with gonadal females (XXF and XYF). Serum testosterone levels were equivalent in adult XXM and XYM, as was serum estrogen in XXF and XYF mice. To remove the effects of gonadal hormones, gonadectomized FCG mice were subjected to MCAO. Gonadectomy significantly increased infarct volumes in females, while no change was seen in gonadectomized males, indicating that estrogen loss increases ischemic sensitivity. Estradiol supplementation in gonadectomized FCG mice rescued this phenotype. Interestingly, FCG male mice were less sensitive to effects of hormones. This may be due to enhanced expression of the transgene Sry in brains of FCG male mice. Sex differences in ischemic stroke sensitivity appear to be shaped by organizational and activational effects of sex hormones, rather than sex chromosomal complement.

Novel insight into circular RNA HECTD1 in astrocyte activation via autophagy by targeting MIR142-TIPARP: Implications for cerebral ischemic stroke.

PubMed

Han, Bing; Zhang, Yuan; Zhang, Yanhong; Bai, Ying; Chen, Xufeng; Huang, Rongrong; Wu, Fangfang; Leng, Shuo; Chao, Jie; Zhang, John H; Hu, Gang; Yao, Honghong

2018-06-25

Circular RNAs (circRNAs) are highly expressed in the central nervous system and are involved in the regulation of physiological and pathophysiological processes. However, the potential role of circRNAs in stroke remains largely unknown. Here, using a circRNA microarray, we showed that circular RNA Hectd1 (circHectd1) levels were significantly increased in ischemic brain tissues in transient middle cerebral artery occlusion (tMCAO) mouse stroke models and further validated this finding in plasma samples from acute ischemic stroke (AIS) patients. Knockdown of circHectd1 expression significantly decreased infarct areas, attenuated neuronal deficits, and ameliorated astrocyte activation in tMCAO mice. Mechanistically, circHECTD1 functions as an endogenous MIR142 (microRNA 142) sponge to inhibit MIR142 activity, resulting in the inhibition of TIPARP (TCDD inducible poly[ADP-ribose] polymerase) expression with subsequent inhibition of astrocyte activation via macroautophagy/autophagy. Taken together, the results of our study indicate that circHECTD1 and its coupling mechanism are involved in cerebral ischemia, thus providing translational evidence that circHECTD1 can serve as a novel biomarker of and therapeutic target for stroke.

Dragon's blood dropping pills have protective effects on focal cerebral ischemia rats model.

PubMed

Xin, Nian; Yang, Fang-Ju; Li, Yan; Li, Yu-Juan; Dai, Rong-Ji; Meng, Wei-Wei; Chen, Yan; Deng, Yu-Lin

2013-12-15

Dragon's blood is a bright red resin obtained from Dracaena cochinchinensis (Lour.) S.C.Chen (Yunnan, China). As a traditional Chinese medicinal herb, it has great traditional medicinal value and is used for wound healing and to stop bleeding. Its main biological activity comes from phenolic compounds. In this study, phenolic compounds were made into dropping pills and their protective effects were examined by establishing focal cerebral ischemia rats model used method of Middle Cerebral Artery Occlusion (MCAO), and by investigating indexes of neurological scores, infarct volume, cerebral index, cerebral water content and oxidation stress. Compared to model group, high, middle and low groups of Dragon's blood dropping pills could improve the neurological function significantly (p<0.01) and reduce cerebral infarct volume of focal cerebral ischemia rats remarkably (p<0.05-0.01). Meanwhile, each group could alleviate cerebral water content and cerebral index (p<0.05-0.01) and regulate oxidative stress of focal cerebral ischemia rats obviously (p<0.05-0.01). Activities of middle group corresponded with that treated with positive control drug. The results obtained here showed that Dragon's blood dropping pills had protective effects on focal cerebral ischemia rats. Copyright © 2013 Elsevier GmbH. All rights reserved.

Integrated pharmacokinetics of major bioactive components in MCAO rats after oral administration of Huang-Lian-Jie-Du-Tang.

PubMed

Zhu, Huaxu; Qian, Zhilei; Li, Huan; Guo, Liwei; Pan, Linmei; Zhang, Qichun; Tang, Yuping

2012-05-07

Huang-Lian-Jie-Du-Tang (HLJDT, or Oren-gedoku-to in Japanese), an important multi-herb remedy in China and other Asia countries, has been used clinically to treat cerebral ischemia for decades. According to the previous studies we have reported, an HPLC method was developed and validated for determination of berberine, palmatine, baicalin, baicalein and geniposide simultaneously in MCAO rat plasma after administration of HLJDT aqueous extract. A classified integral pharmacokinetic method was put forward after having compared the integrated concentration-time profile with that of single component. An AUC based weighting approach was used for integrated principle. The results indicated the classified integral pharmacokinetic profile of index components from HLJDT could reveal the pharmacokinetic behavior of original components, and was corresponding to the holistic pharmacological effects of anti-ischemia with HLJDT. This study was aimed to explore an approach that could be applied to integrate the pharmacokinetic behavior of different components derived from HLJDT. The integrated pharmacokinetic results also provided more information for further understanding of the clinical cerebrovascular disease in use of HLJDT. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Dental cervical lesions associated with occlusal erosion and attrition.

PubMed

Khan, F; Young, W G; Shahabi, S; Daley, T J

1999-09-01

Acid demineralization of teeth causes occlusal erosion and attrition, and shallow and wedge-shaped cervical lesions putatively involving abfraction. From 250 patients with tooth wear, 122 with cervical lesions were identified. From epoxy resin replicas of their dentitions, associations of occlusal attrition or erosion or no wear with cervical lesions were recorded at 24 tooth sites (total 2928 sites). Criteria used to discriminate occlusal attrition from erosion, and shallow from grooved, wedge-shaped or restored cervical lesions were delineated by scanning electron microscopy. A 96 per cent association was found between occlusal and cervical pathology. Shallow cervical lesions were more commonly found in association with occlusal erosion. Wedge-shaped lesions were found equally commonly in association with occlusal erosion, as with attrition. Grooved and restored cervical lesions were uncommon. Differences were appreciated in the associations within incisor, canine, premolar and molar tooth sites which related more to the site-specificity of dental erosion than to attrition from occlusal forces. Non-carious lesions on teeth then have multifactorial aetiology and pathogenesis in which erosion and salivary protection play central roles. Dentists should primarily consider erosion in the diagnosis, prevention and treatment of tooth wear.

[Measurement of periapical pressure created by occlusal loading].

PubMed

Dobó, Nagy Csaba; Fejérdy, Pál; Angyal, János; Harasztosi, Lajos; Daróczi, Lajos; Beke, Dezsó; Wesselink, Paul R

2004-04-01

The aim of this study was to develop an in vitro model in which the pressure in the periapical tissues can be measured during loading. Extracted human maxillary central incisors were embedded into resin blocks that had physical characteristics similar to bone and periodontal ligament. Each tooth was loaded with 20, 40, 50, 60, 75, 85, 100, 200, 300 and 450 N vertical forces from the incisal edge of the crown; this procedure was carried out three consecutive times. A minute resistor embedded in the periapical space was used to detect apical pressure changes during occlusal loading. The ratio of apical pressure changes (delta P) to the loading force changes (delta F) was calculated. The periapical pressure detected was in direct proportion to the loading force. The mean value of delta P/delta F was 5.994 kPa/N (SD = 2.04). Direct proportionality was found between the coronal loading and the apical hydrostatic pressure. The (delta P)/(delta F) ratio determined in this study makes it easier to estimate the apical hydrostatic pressure values during occlusal loading of single rooted teeth. In this study the apical pressure generated under occlusal loading was of the same magnitude as that estimated with the finite element method.

Rat brain digital stereotaxic white matter atlas with fine tract delineation in Paxinos space and its automated applications in DTI data analysis.

PubMed

Liang, Shengxiang; Wu, Shang; Huang, Qi; Duan, Shaofeng; Liu, Hua; Li, Yuxiao; Zhao, Shujun; Nie, Binbin; Shan, Baoci

2017-11-01

To automatically analyze diffusion tensor images of the rat brain via both voxel-based and ROI-based approaches, we constructed a new white matter atlas of the rat brain with fine tracts delineation in the Paxinos and Watson space. Unlike in previous studies, we constructed a digital atlas image from the latest edition of the Paxinos and Watson. This atlas contains 111 carefully delineated white matter fibers. A white matter network of rat brain based on anatomy was constructed by locating the intersection of all these tracts and recording the nuclei on the pathway of each white matter tract. Moreover, a compatible rat brain template from DTI images was created and standardized into the atlas space. To evaluate the automated application of the atlas in DTI data analysis, a group of rats with right-side middle cerebral artery occlusion (MCAO) and those without were enrolled in this study. The voxel-based analysis result shows that the brain region showing significant declines in signal in the MCAO rats was consistent with the occlusion position. We constructed a stereotaxic white matter atlas of the rat brain with fine tract delineation and a compatible template for the data analysis of DTI images of the rat brain. Copyright © 2017 Elsevier Inc. All rights reserved.

Defining degree of aortic occlusion for partial-REBOA: A computed tomography study on large animals.

PubMed

Reva, Viktor A; Matsumura, Yosuke; Samokhvalov, Igor M; Pochtarnik, Alexander A; Zheleznyak, Igor S; Mikhailovskaya, Ekaterina M; Morrison, Jonathan J

2018-04-20

Partial resuscitative endovascular balloon occlusion of the aorta (P-REBOA) is a modified REBOA technique designed to help ameliorate ischemia-reperfusion injury. The balloon is partially deflated, allowing a proportion of aortic flow distal to the balloon. The aim of this study is to use an ovine model of haemorrhagic shock to correlate the degree of occlusion to several hemodynamic indices. Six sheep weighing 35-46 kg underwent a controlled venous haemorrhage inside a CT scanner until the systolic arterial pressure (AP) dropped to <90 mmHg. A balloon positioned in an aortic zone I was incrementally filled with 1 mL of saline, with serial measurement of the proximal (carotid artery) and distal (femoral artery) mean APs (MAP) and intra-balloon pressure (IBP), along with CT imaging, following each inflation, until full occlusion was achieved. A diameter of the aorta at zone I was 16.0 (15.7-17.2) mm, with a cross-sectional area of 212 (194-233) mm 2 . Median volume of saline injected into the balloon until total occlusion was 7.0 (6.3-8.5) mL. During gradual balloon inflation, proximal MAP increased and distal MAP decreased proportionate to the degree of occlusion, in a linear fashion (proximal: r 2  = 0.85, p < 0.001; distal: r 2  = 0.95, p < 0.001). The femoral/carotid (F/C) pressure gradient also demonstrated a linear trend (r 2  = 0.90, p < 0.001). The relationship between percentage occlusion and IBP was sigmoid. MAP values became significantly different at 40-49% occlusion and more (p < 0.01). Furthermore, a drop in the distal pulse pressure from 7.0 (5.5-16.5) to 2.0 (1.5-5.0) mmHg was observed at 80% occlusion. All animals had femoral pulse pressure <5 mmHg at 80% of occlusion and more, which also coincided with the observed loss of pulsatility of the femoral wave-form. Serial CT angiography at an ovine model of haemorrhagic shock demonstrates a correlation between the femoral MAP, F/C pressure gradient and degree of zone

Reliable porcine coronary model of chronic total occlusion using copper wire stents and bioabsorbable levo-polylactic acid polymer.

PubMed

Sim, Doo Sun; Jeong, Myung Ho; Cha, Kyoung Rae; Park, Suk Ho; Park, Jong Oh; Shin, Young Min; Shin, Heungsoo; Hong, Young Joon; Ahn, Youngkeun; Schwartz, Robert S; Kang, Jung Chaee

2012-12-01

Chronic total occlusion (CTO) remains a challenge in interventional cardiology. We investigated the feasibility and reliability of copper wire stents and levo-polylactic acid (l-PLA) as a means of CTO induction in a porcine model. In one group of 20 swine, copper stents were crimped on a 3.0mm angioplasty balloon and inserted into the mid-left anterior descending coronary artery (LAD). In the other group of 20 swine, l-PLA was wrapped on a guidewire and pushed into the distal LAD with a 3.0mm balloon catheter to induce embolization. Of 20 swine which underwent copper stent implantation, 13 died of stent thrombosis. In the remaining 7 swine, total or near total occlusion with collateral circulation was observed at 5 weeks. Of 20 swine which underwent l-PLA embolization, 4 died of ventricular fibrillation during or shortly after the procedure. Serial histopathologic studies showed complete absorption of the polymer with replacement by fibrotic tissue approximately 4 weeks following the polymer implantation. CTO could be reliably induced in porcine coronary arteries by copper stents and l-PLA. These models may support investigation of new percutaneous devices to facilitate CTO interventions. Copyright © 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Part-time occlusion therapy for amblyopia in older children

PubMed Central

Singh, Inderpreet; Sachdev, Nishant; Kaushik, Sushmita

2008-01-01

Aim: To compare the efficacy of part-time versus full-time occlusion for treatment of amblyopia in children aged 7-12 years. Materials and Methods: Prospective interventional case series. One hundred children between 7-12 years of age with anisometropic (57), strabismic (25) and mixed (18) unilateral amblyopia were randomized (simple randomization) into four groups (25 each) to receive two hours, four hours, six hours or full-time occlusion therapy. Children were regularly followed up at six-weekly intervals for a minimum of three visits. Statistical Analysis: Intragroup visual improvement was analyzed using paired t-test while intergroup comparisons were done using ANOVA and unpaired t-test. Results: All four groups showed significant visual improvement after 18 weeks of occlusion therapy (P<0.001). Seventy-three (73%) of the total 100 eyes responded to amblyopia therapy with 11 eyes (44%), 17 eyes (68%), 22 eyes (88%) and 23 eyes (92%) being amblyopia responders in the four groups respectively, with the least number of responders in the two hours group. In mild to moderate amblyopia (vision 20/30 to 20/80), there was no significant difference in visual outcome among the four groups (P=0.083). However, in severe amblyopia (vision 20/100 or worse), six hours (P=0.048) and full-time occlusion (P=0.027) treatment were significantly more effective than two hours occlusion. Conclusion: All grades of part-time occlusion are comparable to full-time occlusion in effectiveness of treatment for mild to moderate amblyopia in children between 7-12 years of age unlike in severe amblyopia, where six hours and full-time occlusion were more effective than two hours occlusion therapy. PMID:18974515

Part-time occlusion therapy for amblyopia in older children.

PubMed

Singh, Inderpreet; Sachdev, Nishant; Brar, Gagandeep S; Kaushik, Sushmita

2008-01-01

To compare the efficacy of part-time versus full-time occlusion for treatment of amblyopia in children aged 7-12 years. Prospective interventional case series. One hundred children between 7-12 years of age with anisometropic (57), strabismic (25) and mixed (18) unilateral amblyopia were randomized (simple randomization) into four groups (25 each) to receive two hours, four hours, six hours or full-time occlusion therapy. Children were regularly followed up at six-weekly intervals for a minimum of three visits. Intragroup visual improvement was analyzed using paired t-test while intergroup comparisons were done using ANOVA and unpaired t-test. All four groups showed significant visual improvement after 18 weeks of occlusion therapy ( P < 0.001). Seventy-three (73%) of the total 100 eyes responded to amblyopia therapy with 11 eyes (44%), 17 eyes (68%), 22 eyes (88%) and 23 eyes (92%) being amblyopia responders in the four groups respectively, with the least number of responders in the two hours group. In mild to moderate amblyopia (vision 20/30 to 20/80), there was no significant difference in visual outcome among the four groups ( P =0.083). However, in severe amblyopia (vision 20/100 or worse), six hours ( P =0.048) and full-time occlusion ( P =0.027) treatment were significantly more effective than two hours occlusion. All grades of part-time occlusion are comparable to full-time occlusion in effectiveness of treatment for mild to moderate amblyopia in children between 7-12 years of age unlike in severe amblyopia, where six hours and full-time occlusion were more effective than two hours occlusion therapy.

Occlusal plane location in edentulous patients: a review.

PubMed

Shetty, Sanath; Zargar, Nazia Majeed; Shenoy, Kamalakanth; Rekha, V

2013-09-01

Occlusal plane orientation is an important factor in the construction of a complete denture. Occlusal plane could be oriented using landmarks in the mandibular arch as well as in the maxillary arch. In the mandibular arch there are few landmarks which could be used to orient the occlusal plane like the retromolar pad, corner of the lips (lower lip length) whereas the maxillary arch has a number of landmarks, of which the ala-tragal line is the most commonly used and the same being the most controversial. In the following article different landmarks and its accuracy for orientating the occlusal plane in an edentulous subject as studied by various authors has been discussed.

Osteogenesis imperfecta with right renal artery occlusion

PubMed Central

Vaish, Arvind Kumar; Kumar, Nitin; Jain, Nirdesh; Agarwal, Abhishek

2012-01-01

We here report a case of osteogenesis imperfecta who presented with severe hypertension and left ventricular failure and had right renal artery occlusion. The case is very interesting as renal artery occlusion has not been reported earlier in osteogenesis imperfecta. PMID:22962392

Proximal Occlusion of Medium-Sized Vessels with the Penumbra Occlusion Device: A Study of Safety and Efficacy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jambon, E.; Petitpierre, F.; Brizzi, V.

PurposeTo retrospectively investigate the safety and efficacy of hybrid proximal coiling of various medium-sized vessels (4 to 8 mm) using the Penumbra Occlusion Device (POD).Materials and MethodsFrom October 2014 to February 2016, 37 proximal embolizations were performed with PODs in 36 patients (mean age: 50.8, range: 10–86; 29 male, 7 female). Vessel occlusions were achieved under fluoroscopic guidance using a 2.7 French microcatheter. Among the 36 vessels targeted, 16 were splenic arteries, 11 renal arteries, 4 mesenteric arteries, 3 arteriovenous fistulae, 1 iliac artery, and 1 gonadal vein. Intermittent follow-up angiography was performed to assess the flow for final occlusion. Outcomesmore » and complications were assessed by clinical and/or imaging follow-up.ResultsTo produce proximal occlusion of the intended vessels, the POD was used alone in 19 embolizations (51.4 %). In 12 procedures (32.4 %), POD was used as a coil constrainer to secure the coil construct. In 6 procedures (16.2 %), additional embolic devices were used to achieve vessel occlusion after initial POD deployment. After a mean follow-up of 3.2 months, no POD migration was observed but two complications occurred (5.4 %): one post embolic syndrome and one extensive infarction with splenic abscess.ConclusionThe POD system allows safe and effective proximal embolization of medium-sized vessels in a variety of clinical settings.« less

A possible association of idiopathic osteosclerosis with excessive occlusal forces.

PubMed

Misirlioglu, Melda; Nalcaci, Rana; Baran, Ilgi; Adisen, Mehmet Zahit; Yilmaz, Selmi

2014-03-01

The aim of the study was to determine the relationship between idiopathic osteosclerotic lesions and occlusal forces using the T-Scan II computerized occlusal analysis device, and to test the sensitivity of the system in occlusal analysis. The study was conducted with 21 volunteers with idiopathic osteosclerosis (IO; 14 women, 7 men) aged between 17 and 62 years (mean 29.95). For every patient, seven or eight recordings were made with the T-Scan II occlusal analysis device in maximum intercuspation, and the last two (excluding any with technical problems) were chosen for evaluation. For each lesion-related area, the distribution of high occlusal forces from two different movies was analyzed. In 18 patients (85.71%), lesions were observed in an area of high occlusal force, and in 13 patients (61.9%), the lesions were located at the first area subjected to high occlusal forces. The percentage distribution of high forces at a lesion related area ranged from 0% to 88%. On average, the high forces at an osteosclerotic lesion area accounted for 20% of the maximum total force. No statistical differences were observed between the measurements of the two selected recordings (P > .05). The findings of this study suggest a possible relationship between IO and occlusal forces and primary contacts. T-Scan II was found to be a successful diagnostic device for detecting primary contacts and excessive occlusal forces.

Occlusal contact of fixed implant prostheses using functional bite impression technique.

PubMed

Suzuki, Yasunori; Shimpo, Hidemasa; Ohkubo, Chikahiro

2015-02-01

Functional bite impression (FBI) has been described as a definitive impression made under occlusal force after functional generated path (FGP) recording. This study compared the accuracy of occlusal contact of implant-fixed prostheses using the FBI technique and the conventional impression technique. Twelve subjects, each missing a single premolar or molar, were selected for this study. The conditions of the occlusal contacts were identified by the modified transillumination method. The occlusal contact condition was determined by comparing the rate of change in the occlusal contact area of the implant-fixed prostheses and both adjacent teeth before and after occlusal adjustment. The rate of change in the occlusal contact area using the FBI technique was 96%, and the rate using the conventional technique was 54%. The occlusal contact of implant prostheses using the FBI technique revealed better accuracy than that of the conventional technique. Regarding the FBI technique, a precise and functional prosthesis could be produced by completing the maxillomandibular registration, impression, and FGP at the same time.

21 CFR 870.2890 - Vessel occlusion transducer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Vessel occlusion transducer. 870.2890 Section 870.2890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2890 Vessel occlusion...

21 CFR 870.2890 - Vessel occlusion transducer.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vessel occlusion transducer. 870.2890 Section 870.2890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2890 Vessel occlusion...

Proteomic analysis of cPKCβII-interacting proteins involved in HPC-induced neuroprotection against cerebral ischemia of mice.

PubMed

Bu, Xiangning; Zhang, Nan; Yang, Xuan; Liu, Yanyan; Du, Jianli; Liang, Jing; Xu, Qunyuan; Li, Junfa

2011-04-01

Hypoxic preconditioning (HPC) initiates intracellular signaling pathway to provide protection against subsequent cerebral ischemic injuries, and its mechanism may provide molecular targets for therapy in stroke. According to our study of conventional protein kinase C βII (cPKCβII) activation in HPC, the role of cPKCβII in HPC-induced neuroprotection and its interacting proteins were determined in this study. The autohypoxia-induced HPC and middle cerebral artery occlusion (MCAO)-induced cerebral ischemia mouse models were prepared as reported. We found that HPC reduced 6 h MCAO-induced neurological deficits, infarct volume, edema ratio and cell apoptosis in peri-infarct region (penumbra), but cPKCβII inhibitors Go6983 and LY333531 blocked HPC-induced neuroprotection. Proteomic analysis revealed that the expression of four proteins in cytosol and eight proteins in particulate fraction changed significantly among 49 identified cPKCβII-interacting proteins in cortex of HPC mice. In addition, HPC could inhibit the decrease of phosphorylated collapsin response mediator protein-2 (CRMP-2) level and increase of CRMP-2 breakdown product. TAT-CRMP-2 peptide, which prevents the cleavage of endogenous CRMP-2, could inhibit CRMP-2 dephosphorylation and proteolysis as well as the infarct volume of 6 h MCAO mice. This study is the first to report multiple cPKCβII-interacting proteins in HPC mouse brain and the role of cPKCβII-CRMP-2 in HPC-induced neuroprotection against early stages of ischemic injuries in mice. © 2011 The Authors. Journal of Neurochemistry © 2011 International Society for Neurochemistry.

High-dose estrogen treatment at reperfusion reduces lesion volume and accelerates recovery of sensorimotor function after experimental ischemic stroke.

PubMed

Carpenter, Randall S; Iwuchukwu, Ifeanyi; Hinkson, Cyrus L; Reitz, Sydney; Lee, Wonhee; Kukino, Ayaka; Zhang, An; Pike, Martin M; Ardelt, Agnieszka A

2016-05-15

Estrogens have previously been shown to protect the brain against acute ischemic insults, by potentially augmenting cerebrovascular function after ischemic stroke. The current study hypothesized that treatment with sustained release of high-dose 17β-estradiol (E2) at the time of reperfusion from middle cerebral artery occlusion (MCAO) in rats would attenuate reperfusion injury, augment post-stroke angiogenesis and cerebral blood flow, and attenuate lesion volume. Female Wistar rats underwent ovariectomy, followed two weeks later by transient, two-hour right MCAO (tMCAO) and treatment with E2 (n=13) or placebo (P; n=12) pellets starting at reperfusion. E2 treatment resulted in significantly smaller total lesion volume, smaller lesions within striatal and cortical brain regions, and less atrophy of the ipsilateral hemisphere after six weeks of recovery. E2-treated animals exhibited accelerated recovery of contralateral forelimb sensorimotor function in the cylinder test. Magnetic resonance imaging (MRI) showed that E2 treatment reduced the formation of lesion cysts, decreased lesion volume, and increased lesional cerebral blood flow (CBF). K(trans), a measure of vascular permeability, was increased in the lesions. This finding, which represents lesion neovascularization, was not altered by E2 treatment. Ischemic stroke-related angiogenesis and vessel formation was confirmed with immunolabeling of brain tissue and was not altered with E2 treatment. In summary, E2 treatment administered immediately following reperfusion significantly reduced lesion size, cyst formation, and brain atrophy while improving lesional CBF and accelerating recovery of functional deficits in a rat model of ischemic stroke. Copyright © 2016 Elsevier B.V. All rights reserved.

Does compliance with amblyopia management improve following supervised occlusion treatment?

PubMed

El-Ghrably, I A; Longville, D; Gnanaraj, L

2007-01-01

To demonstrate improvement in compliance following supervised occlusion therapy for amblyopia in children who had failed to respond to outpatient treatment. Retrospective review of the visual outcome of 30 children who were admitted to an ophthalmology ward for 1-day intensive supervised occlusion. These children had documented poor compliance and previously failed to respond to the outpatient occlusion treatment. During their stay a trained ophthalmology nurse educated parents regarding amblyopia and the benefits of occlusion therapy. Visual acuity (VA) of the amblyopic and fellow eyes was recorded on admission, discharge, and at each subsequent visit. The compliance was recorded from parent's history and also indirectly by noticing improvement in vision. The mean supervised occlusion was 7.4 hours (range 4-12 hours). The compliance with occlusion therapy improved in 23 children (77%) after discharge. The mean duration of occlusion after discharge improved to 4 hours (range 1-12 hours). The mean follow-up was 18 months (range 4-24 months). Though there was no dramatic improvement in VA at discharge there was a statistically significant improvement in VA between admission and last recorded VA (p<0.0001). Of the 23 children who were compliant with occlusion following discharge, 21 (91%) gained at least one line of acuity in their amblyopic eye on the last assessment of their VA and five of them achieved 6/12. Of the seven children who did not comply with occlusion following discharge, only one patient gained one line improvement in his amblyopic eye. This study shows that supervised occlusion treatment and parental education was effective in children who had initially failed traditional outpatient treatment.

[Cilioretinal artery occlusion and central retinal vein occlusion complicating hyperhomocysteinemia: a case report].

PubMed

Berkani, Z; Kitouni, Y; Belhadj, A; Sifi, K; Abbadi, N; Bellatrache, C; Hartani, D; Kherroubi, R

2013-09-01

Hyperhomocysteinemia is known to be a risk factor in both retinal artery and retinal vein occlusions. We report the case of a young patient with combined occlusion of the cilioretinal artery and the central retinal vein due to hyperhomocysteinemia. A 23-year-old patient without significant medical history, presented for sudden, painless visual loss in the right eye. Ophthalmologic examination revealed best-corrected visual acuity of the right eye 8/10 P2, and 10/10 P2 on the left. Anterior segment exam was normal in both eyes, while the right fundus revealed white, ischemic edema, centered around a cilioretinal artery, sparing the fovea, with some hemorrhagic spots and disc edema. Fluorescein angiography confirmed delayed filling of the right cilioretinal artery and revealed a normal disc on the left. Two weeks later, the clinical picture had evolved into a right ischemic CRVO, confirmed by a second angiogram, with a decrease in visual acuity to 3/10. A work-up was performed, including: a full lipid profile, serum electrolytes, ESR, CRP, a complete blood count (leukocytes, platelets, hemoglobin were normal), a coagulation work-up (PT, PTT, protein C, protein S, antithrombin III, factor V Leiden were normal), ANCA, antiphospholipid antibodies and antinuclear antibodies were negative, and finally cardiology studies (cardiac echo, carotid Doppler) and neurology (brain MRI) were ordered and came back normal. Otherwise, plasma homocysteine was moderately high on two samples, at 18.3 μmol/L and 17.78 μmol/L. Thyroid and renal work-ups were ordered. Urgent PRP was performed, and vitamin therapy (vitB12, vitB6, folic acid) was instituted. The subsequent course was remarkable for recovery of visual acuity to 10/10, P2 with persistence of an inferior altitudinal central scotoma. MTHFR C677T polymorphism was negative. Retinal vascular occlusions (RVO) are serious events, which require investigation for underlying systemic disease, which can be life-threatening. The clinical

Effects of the combined treatment of bone marrow stromal cells with mild exercise and thyroid hormone on brain damage and apoptosis in a mouse focal cerebral ischemia model.

PubMed

Akhoundzadeh, Kobar; Vakili, Abedin; Sameni, Hamid Reza; Vafaei, Abbas Ali; Rashidy-Pour, Ali; Safari, Manouchehr; Mohammadkhani, Razieh

2017-08-01

This study examined whether post-stroke bone marrow stromal cells (BMSCs) therapy combined with exercise (EX) and/or thyroid hormone (TH) could reduce brain damage in an experimental ischemic stroke in mice. Focal cerebral ischemia was induced under Laser Doppler Flowmetry (LDF) guide by 45 min of middle cerebral artery occlusion (MCAO), followed by 7 days of reperfusion in albino mice. BMSCs were injected into the right cerebral ventricle 24 h after MCAO, followed by daily injection of T3 (20 μg/100 g weight S.C) and 6 days of running on a treadmill. Infarct size, neurobehavioral test, TUNEL and BrdU positive cells were evaluated at 7 days after MCAO. Treatment with BMSCs and mild EX alone significantly reduced the infarct volume by 23% and 44%, respectively (both, p < 0.001). The BMSCs + TH, BMSCs + EX, and BMSCs + EX + TH combination therapies significantly reduced the infarct volume by 26%, 51%, and 70%, respectively (all, p < 0.001). A significant improvement in the neurobehavioral functioning was observed in the EX, BMSCs + EX, and BMSCs + EX+ TH groups (p < 0.001). The number of TUNEL-positive cells (a marker of apoptosis) was significantly reduced in the EX, BMSCs, BMSCs + EX, BMSCs + TH, and BMSCs + EX + TH groups (all, p < 0.001). Moreover, the combination therapy considerably increased BrdU-labeled cells in the subventricular zone (SVZ) (p < 0.01). Our findings indicated that the combined treatment of BMSCs with mild EX and TH more efficiently reduces the cerebral infarct size after stroke. More likely, these effects mediate via enchaining generation of new neuronal cells and the attenuation of apoptosis in ischemia stroke in young mice.

Sulfate-based anionic diblock copolymer nanoparticles for efficient occlusion within zinc oxide

NASA Astrophysics Data System (ADS)

Ning, Y.; Fielding, L. A.; Andrews, T. S.; Growney, D. J.; Armes, S. P.

2015-04-01

Occlusion of copolymer particles within inorganic crystalline hosts not only provides a model for understanding the crystallisation process, but also may offer a direct route for the preparation of novel nanocomposite materials with emergent properties. In the present paper, a series of new well-defined anionic diblock copolymer nanoparticles are synthesised by polymerisation-induced self-assembly (PISA) via reversible addition-fragmentation chain transfer (RAFT) aqueous emulsion polymerisation and then evaluated as crystal habit modifiers for the in situ formation of ZnO in aqueous solution. Systematic studies indicate that both the chemical nature (i.e. whether sulfate-based or carboxylate-based) and the mean degree of polymerisation (DP) of the anionic stabiliser block play vital roles in determining the crystal morphology. In particular, sulfate-functionalised nanoparticles are efficiently incorporated within the ZnO crystals whereas carboxylate-functionalised nanoparticles are excluded, thus anionic character is a necessary but not sufficient condition for successful occlusion. Moreover, the extent of nanoparticle occlusion within the ZnO phase can be as high as 23% by mass depending on the sulfate-based nanoparticle concentration. The optical properties, chemical composition and crystal structure of the resulting nanocomposite crystals are evaluated and an occlusion mechanism is proposed based on the observed evolution of the ZnO morphology in the presence of sulfate-based anionic nanoparticles. Finally, controlled deposition of a 5 nm gold sol onto porous ZnO particles (produced after calcination of the organic nanoparticles) significantly enhances the rate of photocatalytic decomposition of a model rhodamine B dye on exposure to a relatively weak UV source.Occlusion of copolymer particles within inorganic crystalline hosts not only provides a model for understanding the crystallisation process, but also may offer a direct route for the preparation of novel

21 CFR 878.4020 - Occlusive wound dressing.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Occlusive wound dressing. 878.4020 Section 878.4020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4020 Occlusive wound dressing...

21 CFR 878.4020 - Occlusive wound dressing.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Occlusive wound dressing. 878.4020 Section 878.4020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4020 Occlusive wound dressing...

21 CFR 878.4020 - Occlusive wound dressing.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Occlusive wound dressing. 878.4020 Section 878.4020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4020 Occlusive wound dressing...

In vitro reproduction of incisal/occlusal cupping/cratering.

PubMed

Dzakovich, John J; Oslak, Robert R

2013-06-01

Occlusal cupping/cratering (depressed dentin surrounded by elevated rims of enamel) has been postulated to be the result of abrasion, bruxism, attrition, acid erosion, stress corrosion, or a combination of these. The primary etiology or the multifactorial sequence of occlusal cupping/cratering remains scientifically unsubstantiated. The purpose of this study was to reproduce occlusal/incisal cupping/cratering in vitro. This study was designed to create cupping/cratering on the occlusal surfaces of extracted human teeth rather than to quantify the amount of lost tooth structure caused by abrasion. One name-brand toothbrush was tested with 2 different dentifrices (of different abrasive potentials [low and high]) and water only (nonabrasive) on extracted human teeth. Six specimens of 4 teeth each (24 teeth) were subjected to horizontal brushing in a 1:1 toothpaste/water slurry and water only. The control group, brushed with water only, demonstrated no visible loss of tooth structure. Each of the specimens brushed with toothpaste, regardless of the degree of abrasivity, demonstrated visible wear of the dentin, resulting in occlusal/incisal cupping/cratering. Pronounced cupping/cratering was caused by horizontal brushing with commercial toothpastes. Brushing in water demonstrated no visual loss of occlusal tooth structure. (J Prosthet Dent 2013;109:384-391). Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Marvels, mysteries, and misconceptions of vascular compensation to peripheral artery occlusion.

PubMed

Ziegler, Matthew A; Distasi, Matthew R; Bills, Randall G; Miller, Steven J; Alloosh, Mouhamad; Murphy, Michael P; Akingba, A George; Sturek, Michael; Dalsing, Michael C; Unthank, Joseph L

2010-01-01

Peripheral arterial disease is a major health problem and there is a significant need to develop therapies to prevent its progression to claudication and critical limb ischemia. Promising results in rodent models of arterial occlusion have generally failed to predict clinical success and led to questions of their relevance. While sub-optimal models may have contributed to the lack of progress, we suggest that advancement has also been hindered by misconceptions of the human capacity for compensation and the specific vessels which are of primary importance. We present and summarize new and existing data from humans, Ossabaw miniature pigs, and rodents which provide compelling evidence that natural compensation to occlusion of a major artery (i) may completely restore perfusion, (ii) occurs in specific pre-existing small arteries, rather than the distal vasculature, via mechanisms involving flow-mediated dilation and remodeling (iii) is impaired by cardiovascular risk factors which suppress the flow-mediated mechanisms and (iv) can be restored by reversal of endothelial dysfunction. We propose that restoration of the capacity for flow-mediated dilation and remodeling in small arteries represents a largely unexplored potential therapeutic opportunity to enhance compensation for major arterial occlusion and prevent the progression to critical limb ischemia in the peripheral circulation.

Marvels, Mysteries, and Misconceptions of Vascular Compensation to Peripheral Artery Occlusion

PubMed Central

ZIEGLER, MATTHEW A.; DISTASI, MATTHEW R.; BILLS, RANDALL G.; MILLER, STEVEN J.; ALLOOSH, MOUHAMAD; MURPHY, MICHAEL P.; AKINGBA, A. GEORGE; STUREK, MICHAEL; DALSING, MICHAEL C.; UNTHANK, JOSEPH L.

2010-01-01

Peripheral arterial disease is a major health problem and there is a significant need to develop therapies to prevent its progression to claudication and critical limb ischemia. Promising results in rodent models of arterial occlusion have generally failed to predict clinical success and led to questions of their relevance. While sub-optimal models may have contributed to the lack of progress, we suggest that advancement has also been hindered by misconceptions of the human capacity for compensation and the specific vessels which are of primary importance. We present and summarize new and existing data from humans, Ossabaw miniature pigs, and rodents which provide compelling evidence that natural compensation to occlusion of a major artery (i) may completely restore perfusion, (ii) occurs in specific pre-existing small arteries, rather than the distal vasculature, via mechanisms involving flow-mediated dilation and remodeling (iii) is impaired by cardiovascular risk factors which suppress the flow-mediated mechanisms and (iv) can be restored by reversal of endothelial dysfunction. We propose that restoration of the capacity for flow-mediated dilation and remodeling in small arteries represents a largely unexplored potential therapeutic opportunity to enhance compensation for major arterial occlusion and prevent the progression to critical limb ischemia in the peripheral circulation. PMID:20141596

Endovascular Treatment of Veno-Occlusive Behcet's Disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tekbas, Guven, E-mail: drgtekbas@gmail.com; Oguzkurt, Levent, E-mail: loguzkurt@yahoo.com; Gur, Serkan, E-mail: mserkangur@yahoo.com

Purpose: To retrospectively evaluate the outcome of endovascular treatments for patients with chronic veno-occlusive disease in different vascular beds secondary to Behcet's disease (BD). There are few case reports on the subject, and this is the largest study to date. Materials and Methods: From January 2001 through October 2009, chronic venous occlusions were treated in 10 patients (all male [age range 18-76 years]) with BD using percutaneous transluminal angioplasty and/or stent placement. All patients were symptomatic and had chronic iliofemoral deep venous thrombosis (DVT; n = 5), central venous occlusion (n = 3), or Budd-Chiari syndrome (BCS; n = 2).more » All patients met criteria of the International Study Group on Behcet's Disease. Results: Two of five patients with DVT had unsuccessful recanalization attempts. Three patients had successful recanalization with stent placement. All three veins were occluded within 1 month with unsuccessful reinterventions. Three patients with chronic central venous occlusion had successful recanalization with percutaneous transluminal angioplasty (n = 1) and stent placement (n = 2). Two patients had reocclusion with successful reintervention. Two BCS patients had successful treatment with stent placements. Overall technical success was 69%, and no procedural complications were encountered. None of the patients with chronic DVT had patent veins; however, all patients with central venous occlusion or BCS had patent veins on color Doppler ultrasonography at follow-up ranging from 3 to 48 months after intervention. Conclusion: Endovenous treatment for chronic iliofemoral DVT due to BD had a poor outcome. However, long-term outcome after endovenous treatment for upper-extremity central venous occlusion and BCS syndrome was good.« less

Analysis of occlusal variables, dental attrition, and age for distinguishing healthy controls from female patients with intracapsular temporomandibular disorders.

PubMed

Seligman, D A; Pullinger, A G

2000-01-01

Confusion about the relationship of occlusion to temporomandibular disorders (TMD) persists. This study attempted to identify occlusal and attrition factors plus age that would characterize asymptomatic normal female subjects. A total of 124 female patients with intracapsular TMD were compared with 47 asymptomatic female controls for associations to 9 occlusal factors, 3 attrition severity measures, and age using classification tree, multiple stepwise logistic regression, and univariate analyses. Models were tested for accuracy (sensitivity and specificity) and total contribution to the variance. The classification tree model had 4 terminal nodes that used only anterior attrition and age. "Normals" were mainly characterized by low attrition levels, whereas patients had higher attrition and tended to be younger. The tree model was only moderately useful (sensitivity 63%, specificity 94%) in predicting normals. The logistic regression model incorporated unilateral posterior crossbite and mediotrusive attrition severity in addition to the 2 factors in the tree, but was slightly less accurate than the tree (sensitivity 51%, specificity 90%). When only occlusal factors were considered in the analysis, normals were additionally characterized by a lack of anterior open bite, smaller overjet, and smaller RCP-ICP slides. The log likelihood accounted for was similar for both the tree (pseudo R(2) = 29.38%; mean deviance = 0.95) and the multiple logistic regression (Cox Snell R(2) = 30.3%, mean deviance = 0.84) models. The occlusal and attrition factors studied were only moderately useful in differentiating normals from TMD patients.

Long-Term Post-Stroke Changes Include Myelin Loss, Specific Deficits in Sensory and Motor Behaviors and Complex Cognitive Impairment Detected Using Active Place Avoidance

PubMed Central

Li, Jie; Ooi, Evelyn; Bloom, Jonathan; Poon, Carrie; Lax, Daniel; Rosenbaum, Daniel M.; Barone, Frank C.

2013-01-01

Persistent neurobehavioral deficits and brain changes need validation for brain restoration. Two hours middle cerebral artery occlusion (tMCAO) or sham surgery was performed in male Sprague-Dawley rats. Neurobehavioral and cognitive deficits were measured over 10 weeks included: (1) sensory, motor, beam balance, reflex/abnormal responses, hindlimb placement, forepaw foot fault and cylinder placement tests, and (2) complex active place avoidance learning (APA) and simple passive avoidance retention (PA). Electroretinogram (ERG), hemispheric loss (infarction), hippocampus CA1 neuronal loss and myelin (Luxol Fast Blue) staining in several fiber tracts were also measured. In comparison to Sham surgery, tMCAO surgery produced significant deficits in all behavioral tests except reflex/abnormal responses. Acute, short lived deficits following tMCAO were observed for forelimb foot fault and forelimb cylinder placement. Persistent, sustained deficits for the whole 10 weeks were exhibited for motor (p<0.001), sensory (p<0.001), beam balance performance (p<0.01) and hindlimb placement behavior (p<0.01). tMCAO produced much greater and prolonged cognitive deficits in APA learning (maximum on last trial of 604±83% change, p<0.05) but only a small, comparative effect on PA retention. Hemispheric loss/atrophy was measured 10 weeks after tMCAO and cross-validated by two methods (e.g., almost identical % ischemic hemispheric loss of 33.4±3.5% for H&E and of 34.2±3.5% for TTC staining). No visual dysfunction by ERG and no hippocampus neuronal loss were detected after tMCAO. Fiber tract damage measured by Luxol Fast Blue myelin staining intensity was significant (p<0.01) in the external capsule and striatum but not in corpus callosum and anterior commissure. In summary, persistent neurobehavioral deficits were validated as important endpoints for stroke restorative research in the future. Fiber myelin loss appears to contribute to these long term behavioral dysfunctions and can be

Combining technologies: a computerized occlusal analysis system synchronized with a computerized electromyography system.

PubMed

Kerstein, Robert B

2004-04-01

Current advances in computer technologies have afforded dentists precision ways to examine occlusal contacts and muscle function. Recently, two separate computer technologies have been synchronized together, so that an operator can record their separate diagnostic data simultaneously. The two systems are: the T Scan II Occlusal Analysis System and the Biopak Electromyography Recording System. The simultaneous recording and playback capacity of these two computer systems allows the operator to analyze and correlate specific occlusal moments to specific electromyographic changes that result from these occlusal moments. This synchronization provides unparalleled evidence of the effect occlusal contact arrangement has on muscle function. Therefore, the occlusal condition of an inserted dental prosthesis or the occlusal scheme of the natural teeth (before and after corrective occlusal adjustments) can be readily evaluated, documented, and quantified for both, quality of occlusal parameters and muscle activity and the responses to the quality of the occlusal condition. This article describes their synchronization and illustrates their use in performing precision occlusal adjustment procedures on two patients: one who demonstrates occlusal disharmony while exhibiting the signs and symptoms of chronic myofascial pain dysfunction syndrome, and the other who had extensive restorative work accomplished but exhibits occlusal discomfort post-operatively.

The effect of occlusion on the semantics of projective spatial terms: a case study in grounding language in perception.

PubMed

Kelleher, John D; Ross, Robert J; Sloan, Colm; Mac Namee, Brian

2011-02-01

Although data-driven spatial template models provide a practical and cognitively motivated mechanism for characterizing spatial term meaning, the influence of perceptual rather than solely geometric and functional properties has yet to be systematically investigated. In the light of this, in this paper, we investigate the effects of the perceptual phenomenon of object occlusion on the semantics of projective terms. We did this by conducting a study to test whether object occlusion had a noticeable effect on the acceptance values assigned to projective terms with respect to a 2.5-dimensional visual stimulus. Based on the data collected, a regression model was constructed and presented. Subsequent analysis showed that the regression model that included the occlusion factor outperformed an adaptation of Regier & Carlson's well-regarded AVS model for that same spatial configuration.

Melorheostosis with occlusion of dorsalis pedis artery.

PubMed

Ishibe, Motomi; Inoue, Masayuki; Saitou, Katsutoshi

2002-02-01

Melorheostosis is an unusual sclerotic dysplasia of bone. The case of a 51-year-old female patient with melorheostosis and occlusion of the dorsalis pedis artery is described. Although numerous vascular anomalies have been noted in patients with melorheostosis, occlusion of the dorsalis pedis artery has not been reported previously.

Methylene Blue Ameliorates Ischemia/Reperfusion-Induced Cerebral Edema: An MRI and Transmission Electron Microscope Study.

PubMed

Fang, Qing; Yan, Xu; Li, Shaowu; Sun, Yilin; Xu, Lixin; Shi, Zhongfang; Wu, Min; Lu, Yi; Dong, Liping; Liu, Ran; Yuan, Fang; Yang, Shao-Hua

2016-01-01

The neuroprotective effect of methylene blue (MB) has been identified against various brain disorders, including ischemic stroke. In the present study, we evaluated the effects of MB on postischemic brain edema using magnetic resonance imaging (MRI) and transmission electron microscopy (TEM). Adult male rats were subjected to transient focal cerebral ischemia induced by 1 h middle cerebral artery occlusion (MCAO), followed by reperfusion. MB was infused intravenously immediately after reperfusion (3 mg/kg) and again at 3 h post-occlusion (1.5 mg/kg). Normal saline was administered as vehicle control. Sequential MRIs, including apparent diffusion coefficient (ADC) and T2-weighted imaging (T2WI), were obtained at 0.5, 2.5, and 48 h after the onset of stroke. Separated groups of animals were sacrificed at 2.5 and 48 h after stroke for ultrastructural analysis by TEM. In addition, final lesion volumes were analyzed by triphenyltetrazolium chloride (TTC) staining at 48 h after stroke. Ischemic stroke induced ADC lesion volume at 0.5 h during MCAOs that were temporally recovered at 1.5 h after reperfusion. No significant difference in ADC-defined lesion was observed between vehicle and MB treatment groups. At 48 h after stroke, MB significantly reduced ADC lesion and T2WI lesion volume and attenuated cerebral swelling. Consistently, MB treatment significantly decreased TTC-defined lesion volume at 48 h after stroke. TEM revealed remarkable swollen astrocytes, astrocytic perivascular end-feet, and concurrent shrunken neurons in the penumbra at 2.5 and 48 h after MCAO. MB treatment attenuated astrocyte swelling, the perivascular astrocytic foot process, and endothelium and also alleviated neuron degeneration. This study demonstrated that MB could decrease postischemic brain edema and provided additional evidence that future clinical investigation of MB for the treatment of ischemic stroke is warrented.

Amalric sign: An augur of ophthalmic artery occlusion

PubMed Central

Hande, Prathibha; Sinha, Babi; Nayak, Shivani; Srinivasan, Srilakshmi; Shetty, Jyothi

2017-01-01

A 75-year-old man presented to us with sudden onset of profound vision loss in his right eye and was identified as suffering from an ophthalmic artery occlusion. Apart from the retinal whitening and box-carring of the retinal arteries, there were characteristic triangular patches of retinal whitening in the midperipheral temporal fundus indicating a previous lateral posterior choroidal artery occlusion. The patient was a chronic smoker and had dyslipidemia. The carotid Doppler study showed complete occlusion of the internal carotid artery. The presence of these triangular patches of retinal whitening or amalric sign can therefore herald a more proximal vessel occlusion. Hence such patients require evaluation on an emergency basis. The characteristic features of the patches on fluorescein angiography and indocyanine green angiography are discussed here. PMID:29044080

Amalric sign: An augur of ophthalmic artery occlusion.

PubMed

Hande, Prathibha; Sinha, Babi; Nayak, Shivani; Srinivasan, Srilakshmi; Shetty, Jyothi

2017-10-01

A 75-year-old man presented to us with sudden onset of profound vision loss in his right eye and was identified as suffering from an ophthalmic artery occlusion. Apart from the retinal whitening and box-carring of the retinal arteries, there were characteristic triangular patches of retinal whitening in the midperipheral temporal fundus indicating a previous lateral posterior choroidal artery occlusion. The patient was a chronic smoker and had dyslipidemia. The carotid Doppler study showed complete occlusion of the internal carotid artery. The presence of these triangular patches of retinal whitening or amalric sign can therefore herald a more proximal vessel occlusion. Hence such patients require evaluation on an emergency basis. The characteristic features of the patches on fluorescein angiography and indocyanine green angiography are discussed here.

Intravitreal triamcinolone acetonide injections in the treatment of retinal vein occlusions.

PubMed

Roth, Daniel B; Cukras, Catherine; Radhakrishnan, Ravi; Feuer, William J; Yarian, David L; Green, Stuart N; Wheatley, Harold M; Prenner, Jonathan

2008-01-01

To report the visual acuity response after intravitreal triamcinolone injection in patients with macular edema due to retinal vein occlusions. Retrospective nonrandomized interventional series of 172 consecutive patients with macular edema due to retinal vein occlusions who were treated with intravitreal triamcinolone acetonide injection. Patients underwent Snellen visual acuity testing and ophthalmoscopic examination at baseline and 1, 3, 6, and 12 months after intravitreal triamcinolone acetonide injection. All subtypes of retinal vein occlusions showed significant improvements in mean visual acuity 1 month after injection. This improvement in visual acuity was maintained over the 12-month period for all but the central retinal vein occlusion group. Seventy-one (41.3%) of the 172 patients received more than one intravitreal triamcinolone injection for unresolved or recurrent macular edema. This study demonstrates a benefit associated with intravitreal triamcinolone acetonide injection for retinal vein occlusions that was maintained by patients with branch retinal vein occlusions and hemiretinal vein occlusions over a 12-month period. Visual acuity improvement was not maintained in patients with central retinal vein occlusions with this course of treatment.

Retinal vein occlusion

MedlinePlus

... of one eye. Exams and Tests Tests to evaluate for vein occlusion include: Exam of the retina after dilating the pupil An eye test that uses a special dye and camera to look at blood flow in the retina and choroid. Intraocular pressure Pupil ...

Neuroprotection by the Traditional Chinese Medicine, Tao-Hong-Si-Wu-Tang, against Middle Cerebral Artery Occlusion-Induced Cerebral Ischemia in Rats

PubMed Central

Wu, Chih-Jen; Chen, Jui-Tai; Yen, Ting-Lin; Jayakumar, Thanasekaran; Chou, Duen-Suey; Hsiao, George; Sheu, Joen-Rong

2011-01-01

Tao-Hong-Si-Wu-Tang (THSWT) is a famous traditional Chinese medicine (TMC). In the present study, oral administration of THSWT (0.7 and 1.4 g kg−1day−1) for 14 days before MCAO dose-dependently attenuated focal cerebral ischemia in rats. MCAO-induced focal cerebral ischemia was associated with increases in hypoxia-inducible factor (HIF)-1α, inducible nitric oxide synthase (iNOS), tumor necrosis factor (TNF)-α, and active caspase-3 expressions in ischemic regions. These expressions were obviously inhibited by 0.7 g kg−1day−1 THSWT treatment. In addition, THSWT inhibited platelet aggregation stimulated by collagen in washed platelets. In an in vivo study, THSWT (16 g kg−1) significantly prolonged platelet plug formation in mice. However, THSWT (20 and 40 μg mL−1) did not significantly reduce the electron spin resonance (ESR) signal intensity of hydroxyl radical (OH•) formation. In conclusion, the most important findings of this study demonstrate for the first time that THSWT possesses potent neuroprotective activity against MCAO-induced focal cerebral ischemia in vivo. This effect may be mediated, at least in part, by the inhibition of both HIF-1α and TNF-α activation, followed by the inhibition of inflammatory responses (i.e., iNOS expression), apoptosis formation (active caspase-3), and platelet activation, resulting in a reduction in the infarct volume in ischemia-reperfusion brain injury. PMID:21076527

Aging causes exacerbated ischemic brain injury and failure of sevoflurane post-conditioning: role of B-cell lymphoma-2.

PubMed

Dong, P; Zhao, J; Zhang, Y; Dong, J; Zhang, L; Li, D; Li, L; Zhang, X; Yang, B; Lei, W

2014-09-05

Aging is associated with exacerbated brain injury after ischemic stroke. Herein, we explored the possible mechanisms underlying the age-associated exacerbated brain injury after ischemic stroke and determined whether therapeutic intervention with anesthetic post-conditioning would provide neuroprotection in aged rats. Male Fisher 344 rats (young, 4 months; aged, 24 months) underwent 2h of middle cerebral artery occlusion (MCAO) followed by 24-h reperfusion, with or without sevoflurane post-conditioning for 15 min immediately at the onset of reperfusion. Compared with young rats, aged rats showed larger infarct size, worse neurological scores and more TUNEL-positive cells in the penumbral cerebral cortex at 24h after MCAO. However, edema formation and motor coordination were similar in both groups. Sevoflurane reduced the infarct size, edema formation, and TUNEL-positive cells, and improved the neurological outcome in young rats but not in aged rats. Molecular studies revealed that basal expression of the anti-apoptotic molecule B-cell lymphoma-2 (Bcl-2) in the brain was lower in aged rats compared with young rats before MCAO, while basal expression of the pro-apoptotic molecule Bcl-2-associated X protein (Bax) showed similar levels in both groups. MCAO reduced Bcl-2 expression and increased Bax expression in both groups; however, Bax increase was more pronounced in aged rats. In young rats, sevoflurane reversed the above MCAO-induced changes. In contrast, sevoflurane failed to enhance Bcl-2 expression but decreased Bax expression in aged rats. These findings suggest that aging-associated reduction in basal Bcl-2 expression in the brain contributes to increased neuronal injury by enhancing cell apoptosis after ischemic stroke. Sevoflurane post-conditioning failed to provide neuroprotection in aged rats, probably due to its inability to increase Bcl-2 levels and prevent apoptosis in the brain. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Role of occlusion in endodontic management: report of two cases.

PubMed

Yu, Christine Y

2004-12-01

The two clinical cases reported demonstrate that traumatic occlusion can play a role in the initiation and progression of pulp and periradicular inflammation. The symptom of persistent pain did not subside after the commencement of endodontic treatment. Traumatic occlusion was identified in both cases to be the main cause and hence occlusal adjustment was performed. This resulted in the gradual resolution of the symptoms. The findings suggest that occlusal trauma is often overlooked in the diagnosis and management of endodontic diseases.

Vinpocetine alleviate cerebral ischemia/reperfusion injury by down-regulating TLR4/MyD88/NF-κB signaling.

PubMed

Wu, Li-Rong; Liu, Liang; Xiong, Xiao-Yi; Zhang, Qin; Wang, Fa-Xiang; Gong, Chang-Xiong; Zhong, Qi; Yang, Yuan-Rui; Meng, Zhao-You; Yang, Qing-Wu

2017-10-06

Inflammatory responses play crucial roles in cerebral ischemia/reperfusion injury. Toll-like receptor 4 (TLR4) is an important mediator of the neuroinflammatory response to cerebral ischemia/reperfusion injury. Vinpocetine is a derivative of the alkaloid vincamine and exerts an anti-inflammatory effect by inhibiting NF-κB activation. However, the effects of vinpocetine on pathways upstream of NF-κB signaling, such as TLR4, have not been fully elucidated. Here, we used mouse middle cerebral artery occlusion (MCAO) and cell-based oxygen-glucose deprivation (OGD) models to evaluate the therapeutic effects and mechanisms of vinpocetine treatment. The vinpocetine treatment significantly reduced mice cerebral infarct volumes and neurological scores. Moreover, the numbers of TUNEL+ and Fluoro-Jade B+ cells were significantly decreased in the ischemic brain tissues after vinpocetine treatment. In the OGD model, the vinpocetine treatment also increased the viability of cultured cortical neurons. Interestingly, vinpocetine exerted a neuroprotective effect on the mouse MCAO model and cell-based OGD model by inhibiting TLR4-mediated inflammatory responses and decreasing proinflammatory cytokine release through the MyD88-dependent signaling pathway, independent of TRIF signaling pathway. In conclusion, vinpocetine exerts anti-inflammatory effects to ameliorate cerebral ischemia/reperfusion injury in vitro and in vivo. Vinpocetine may inhibit inflammatory responses through the TLR4/MyD88/NF-κB signaling pathway, independent of TRIF-mediated inflammatory responses. Thus, vinpocetine may be an attractive therapeutic candidate for the treatment of ischemic cerebral injury or other inflammatory diseases.

Evaluation of the occlusal contact of crowns fabricated with the bite impression method.

PubMed

Makino, Sachi; Okada, Daizo; Shin, Chiharu; Ogura, Reiko; Ikeda, Masaomi; Miura, Hiroyuki

2013-09-30

In prosthodontic treatment, reconstruction of a proper occlusal contact relationship is very important as well as reconstruction of a proper interproximal relationship and marginal fitness. Unfortunately, occlusal relationships are sometimes lost in the process of occlusal adjustment of crowns. The purpose of this study was to compare the occlusal contacts of single crown fabricated by two different types of impression techniques. Nine subjects, whose molars required treatment with crown restoration, were enrolled in this study. Full cast crowns were fabricated using two types of impression techniques: the conventional impression method (CIM) and the bite impression method (BIM). The occlusal contacts of crowns were precisely evaluated at the following stages: after occlusal adjustment on the articulator (Step 0), before occlusal adjustment in the mouth (Step 1), after occlusal adjustment at the intercuspal position (Step 2), and after occlusal adjustment during lateral and protrusive excursions (Step 3). The number of occlusal contacts of the crowns on the functional cusps fabricated with BIM was significantly greater than that with CIM after occlusal adjustment. For this reason, the crowns fabricated with BIM might have a more functionally desirable occlusal surface compared to the crowns fabricated with CIM.

[Comparison of 2 lacrimal punctal occlusion methods].

PubMed

Shalaby, O; Rivas, L; Rivas, A I; Oroza, M A; Murube, J

2001-09-01

To study and compare two methods for canalicular occlusion: Cautery and Punctal Patch. The study included fourty patients divided in two groups of 20 patients. The end point was 4 occluded puncti. The first group underwent deep cauterization resulting in occlusion of the full vertical aspect of the canaliculus. The second group underwent punctal patch technique for canalicular occlusion. Differential parameters were the following: time of intervention, ease of use, risks and precision. In the post operatory, discomfort, subjective and objective improvement in ocular surface as well as long term result of each technique was analysed. Time of intervention was longer for punctal patch compared to cautery. Both methods exhibited similar ease of use and improvement in ocular surface. Precision was high in punctal patch technique showing complete and final occlusion and no punctum needed reopening, while cautery technique presented 20% rate of reopening intervention. Postoperatory discomfort and irritation were remarkably evident with punctal technique, while minimal in cautery technique. Survival analysis after one year follow up, showed a higher rate of advantages for punctal patch technique over cautery technique.

Two-Photon Imaging of Cortical Surface Microvessels Reveals a Robust Redistribution in Blood Flow after Vascular Occlusion

PubMed Central

Schaffer, Chris B; Friedman, Beth; Nishimura, Nozomi; Schroeder, Lee F; Tsai, Philbert S; Ebner, Ford F; Lyden, Patrick D

2006-01-01

A highly interconnected network of arterioles overlies mammalian cortex to route blood to the cortical mantle. Here we test if this angioarchitecture can ensure that the supply of blood is redistributed after vascular occlusion. We use rodent parietal cortex as a model system and image the flow of red blood cells in individual microvessels. Changes in flow are quantified in response to photothrombotic occlusions to individual pial arterioles as well as to physical occlusions of the middle cerebral artery (MCA), the primary source of blood to this network. We observe that perfusion is rapidly reestablished at the first branch downstream from a photothrombotic occlusion through a reversal in flow in one vessel. More distal downstream arterioles also show reversals in flow. Further, occlusion of the MCA leads to reversals in flow through approximately half of the downstream but distant arterioles. Thus the cortical arteriolar network supports collateral flow that may mitigate the effects of vessel obstruction, as may occur secondary to neurovascular pathology. PMID:16379497

The Sigma-1 Receptor Antagonist, S1RA, Reduces Stroke Damage, Ameliorates Post-Stroke Neurological Deficits and Suppresses the Overexpression of MMP-9.

PubMed

Sánchez-Blázquez, Pilar; Pozo-Rodrigálvarez, Andrea; Merlos, Manuel; Garzón, Javier

2018-06-01

The glutamate N-methyl-D-aspartate receptor (NMDAR) plays an essential role in the excitotoxic neural damage that follows ischaemic stroke. Because the sigma-1 receptor (σ1R) can regulate NMDAR transmission, exogenous and putative endogenous regulators of σ1R have been investigated using animal models of ischaemic stroke. As both agonists and antagonists provide some neural protection, the selective involvement of σ1Rs in these effects has been questioned. The availability of S1RA (E-52862/MR309), a highly selective σ1R antagonist, prompted us to explore its therapeutic potential in an animal model of focal cerebral ischaemia. Mice were subjected to right middle cerebral artery occlusion (MCAO), and post-ischaemic infarct volume and neurological deficits were determined across a range of intervals after the stroke-inducing surgery. Intracerebroventricular or intravenous treatment with S1RA significantly reduced the cerebral infarct size and neurological deficits caused by permanent MCAO (pMCAO). Compared with the control/sham-operated mice, the neuroprotective effects of S1RA were observed when delivered up to 5 h prior to surgery and 3 h after ischaemic onset. Interestingly, neither mice with the genetic deletion of σ1R nor wild-type mice that were pre-treated with the σ1R agonist PRE084 showed beneficial effects after S1RA administration with regard to stroke infarction. S1RA-treated mice showed faster behavioural recovery from stroke; this finding complements the significant decreases in matrix metalloproteinase-9 (MMP-9) expression and reactive astrogliosis surrounding the infarcted cortex. Our data indicate that S1RA, via σ1R, holds promising potential for clinical application as a therapeutic agent for ischaemic stroke.

Real-Time MRI-Guided Endovascular Recanalization of Chronic Total Arterial Occlusion in a Swine Model

PubMed Central

Raval, Amish N.; Karmarkar, Parag V.; Guttman, Michael A.; Ozturk, Cengizhan; Sampath, Smita; DeSilva, Ranil; Aviles, Ronnier J.; Xu, Minnan; Wright, Victor J.; Schenke, William H.; Kocaturk, Ozgur; Dick, Alexander J.; Raman, Venkatesh K.; Atalar, Ergin; McVeigh, Elliot R.; Lederman, Robert J.

2006-01-01

Background Endovascular recanalization (guidewire traversal) of peripheral artery chronic total occlusion (CTO) can be challenging. X-Ray angiography resolves CTO poorly. Virtually “blind” device advancement during X-ray-guided interventions can lead to procedure failure, perforation and hemorrhage. Alternatively, magnetic resonance imaging (MRI) may delineate the artery within the occluded segment to enhance procedural safety and success. We hypothesized that real-time MRI (rtMRI) guided CTO recanalization can be accomplished in an animal model. Methods and Results Carotid artery CTO was created by balloon injury in 19 lipid overfed swine. After 6–8 weeks, two underwent direct necropsy analysis for histology, three underwent primary X-ray-guided CTO recanalization attempts, and the remaining 14 underwent rtMRI-guided recanalization attempts in a 1.5T interventional MRI system. rtMRI intervention used custom CTO catheters and guidewires that incorporated MRI receiver antennae to enhance device visibility. The mean length of the occluded segments was 13.3 ± 1.6cm. rtMRI-guided CTO recanalization was successful in 11/14 swine and only 1/3 swine using X-ray alone. After unsuccessful rtMRI (n = 3), X-ray-guided attempts also were all unsuccessful. Conclusions Recanalization of long CTO is feasible entirely using rtMRI guidance. Low profile clinical-grade devices will be required to translate this experience to humans. Endovascular recanalization of chronic total arterial occlusion (CTO) is challenging under conventional X-ray guidance because devices are advanced almost blindly. MRI can image CTO borders and luminal contents, and could potentially guide these procedures. We test the feasibility of real-time MRI guided wire traversal in a swine model of peripheral artery CTO using custom active MRI catheters. PMID:16490819

Collateral Circulation in Chronic Total Occlusions - an interventional perspective.

PubMed

Choo, Gim-Hooi

2015-09-09

Human coronary collaterals are inter-coronary communications that are believed to be present from birth. In the presence of chronic total occlusions, recruitment of flow via these collateral anastomoses to the arterial segment distal to occlusion provide an alternative source of blood flow to the myocardial segment at risk. This mitigates the ischemic injury. Clinical outcome of coronary occlusion ie. severity of myocardial infarction/ischemia, impairment of cardiac function and possibly survival depends not only on the acuity of the occlusion, extent of jeopardized myocardium, duration of ischemia but also to the adequacy of collateral circulation. Adequacy of collateral circulation can be assessed by various methods. These coronary collateral channels have been used successfully as a retrograde access route for percutaneous recanalization of chronic total occlusions. Factors that promote angiogenesis and further collateral remodeling ie. arteriogenesis have been identified. Promotion of collateral growth as a therapeutic target in patients with no suitable revascularization option is an exciting proposal.

Acute pancreatitis during sickle cell vaso-occlusive painful crisis.

PubMed

Ahmed, Shahid; Siddiqui, Anita K; Siddiqui, Rina K; Kimpo, Miriam; Russo, Linda; Mattana, Joseph

2003-07-01

Sickle cell disease is characterized by chronic hemolytic anemia and vaso-occlusive painful crisis. The vascular occlusion in sickle cell disease is a complex process and accounts for the majority of the clinical manifestations of the disease. Abdominal pain is an important component of vaso-occlusive painful crisis and may mimic diseases such as acute appendicitis and cholecystitis. Acute pancreatitis is rarely included as a cause of abdominal pain in patients with sickle cell disease. When it occurs it may result form biliary obstruction, but in other instances it might be a consequence of microvessel occlusion causing ischemia. In this series we describe four cases of acute pancreatitis in patients with sickle cell disease apparently due to microvascular occlusion and ischemic injury to the pancreas. All patients responded to conservative management. Acute pancreatitis should be considered in the differential diagnosis of abdominal pain in patients with sickle cell disease. Copyright 2003 Wiley-Liss, Inc.

Spatiotemporal characterization of brain infarction by sequential multimodal MR imaging following transient focal ischemia in a Rat model of intra-arterial middle cerebral artery occlusion.

PubMed

Gory, Benjamin; Chauveau, Fabien; Bolbos, Radu; Langlois, Jean-Baptiste; Labeyrie, Paul-Emile; Signorelli, Francesco; Turjman, Alexis; Turjman, Francis

2016-12-01

To assess spatiotemporal brain infarction evolution by sequential multimodal magnetic resonance (MR) imaging in an endovascular model of acute stroke in rats. A microwire was selectively placed in the middle cerebral artery (MCA) in 16 consecutives rats during 90 minutes occlusion. Longitudinal 7-T MR imaging, including angiography, diffusion, and perfusion was performed during ischemia, immediately after reperfusion, 3 h and 24 h after subsequent reperfusion. MCA occlusion was complete in 75 % and partial in 18.7 %. Hypoperfusion (mean ± SD) was observed in all animals during ischemia (-59 ± 18 % of contralateral hemisphere, area 31 ± 5 mm 2 ). Infarction volume (mean ± SD) was 90 ± 64 mm 3 during ischemia and 57 ± 67 mm 3 at 24 h. Brain infarction was fronto-parietal cortical in five animals (31 %), striatal in four animals (25 %), and cortico-striatal in seven animals (44 %) at 24 h. All rats survived at 24 h. This model is suitable to neuroprotection studies because of possible acute and close characterization of spatiotemporal evolution of brain infarction by MR imaging techniques, and evidence of ischemic penumbra, the target of neuroprotection agents. However, optimization of the brain infarct reproducibility needs further technical and neurointerventional tools improvements. • Nitinol microwire is MRI compatible allowing spatiotemporal characterization of brain infarction in rats. • Microwire selective placement in middle cerebral artery allows complete artery occlusion in 75 %. • A diffusion/perfusion mismatch during arterial occlusion is observed in 77 % of rats.

Effects of transcranial direct current stimulation on hemichannel pannexin-1 and neural plasticity in rat model of cerebral infarction.

PubMed

Jiang, T; Xu, R X; Zhang, A W; Di, W; Xiao, Z J; Miao, J Y; Luo, N; Fang, Y N

2012-12-13

The aim of this study was to investigate the effects of transcranial direct current stimulation (TDCS) on hemichannel pannexin-1 (PX1) in cortical neurons and neural plasticity, and explore the optimal time window of TDCS therapy after stroke. Adult male Sprague-Dawley rats (n=90) were randomly assigned to sham operation, middle cerebral artery occlusion (MCAO), and TDCS groups, and underwent sham operation, unilateral middle cerebral artery (MCA) electrocoagulation, and unilateral MCA electrocoagulation plus TDCS (daily anodal and cathodal 10 Hz, 0.1 mA TDCS for 30 min beginning day 1 after stroke), respectively. Motor function was assessed using the beam walking test (BWT), and density of dendritic spines (DS) and PX1 mRNA expression were compared among groups on days 3, 7, and 14 after stroke. Effects of PX1 blockage on DS in hippocampal neurons after hypoxia-ischemia were observed. TDCS significantly improved motor function on days 7 and 14 after stroke as indicated by reduced BWT scores compared with the MCAO group. The density of DS was decreased after stroke; the TDCS group had increased DS density compared with the MCAO group on days 3, 7, and 14 (all P<0.0001). Cerebral infarction induced increased PX1 mRNA expression on days 3, 7, and 14 (P<0.0001), and the peak PX1 mRNA expression was observed on day 7. TDCS did not decrease the up-regulated PX1 mRNA expression after stroke on day 3, but did reduce the increased post-stroke PX1 mRNA expression on days 7 and 14 (P<0.0001). TDCS increased the DS density after stroke, indicating that it may promote neural plasticity after stroke. TDCS intervention from day 7 to day 14 after stroke demonstrated motor function improvement and can down-regulate the elevated PX1 mRNA expression after stroke. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

Computational evaluation of aortic occlusion and the proposal of a novel, improved occluder: Constrained endo-aortic balloon occlusion.

PubMed

de Vaal, M H; Gee, M W; Stock, U A; Wall, W A

2016-12-01

Because aortic occlusion is arguably one of the most dangerous aortic manipulation maneuvers during cardiac surgery in terms of perioperative ischemic neurological injury, the purpose of this investigation is to assess the structural mechanical impact resulting from the use of existing and newly proposed occluders. Existing (clinically used) occluders considered include different cross-clamps (CCs) and endo-aortic balloon occlusion (EABO). A novel occluder is also introduced, namely, constrained EABO (CEABO), which consists of applying a constrainer externally around the aorta when performing EABO. Computational solid mechanics are employed to investigate each occluder according to a comprehensive list of functional requirements. The potential of a state of occlusion is also considered for the first time. Three different constrainer designs are evaluated for CEABO. Although the CCs were responsible for the highest strains, largest deformation, and most inefficient increase of the occlusion potential, it remains the most stable, simplest, and cheapest occluder. The different CC hinge geometries resulted in poorer performance of CC used for minimally invasive procedures than conventional ones. CEABO with a profiled constrainer successfully addresses the EABO shortcomings of safety, stability, and positioning accuracy, while maintaining its complexities of operation (disadvantage) and yielding additional functionalities (advantage). Moreover, CEABO is able to achieve the previously unattainable potential to provide a clinically determinable state of occlusion. CEABO offers an attractive alternative to the shortcomings of existing occluders, with its design rooted in achieving the highest patient safety. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Fast Occlusion and Shadow Detection for High Resolution Remote Sensing Image Combined with LIDAR Point Cloud

NASA Astrophysics Data System (ADS)

Hu, X.; Li, X.

2012-08-01

The orthophoto is an important component of GIS database and has been applied in many fields. But occlusion and shadow causes the loss of feature information which has a great effect on the quality of images. One of the critical steps in true orthophoto generation is the detection of occlusion and shadow. Nowadays LiDAR can obtain the digital surface model (DSM) directly. Combined with this technology, image occlusion and shadow can be detected automatically. In this paper, the Z-Buffer is applied for occlusion detection. The shadow detection can be regarded as a same problem with occlusion detection considering the angle between the sun and the camera. However, the Z-Buffer algorithm is computationally expensive. And the volume of scanned data and remote sensing images is very large. Efficient algorithm is another challenge. Modern graphics processing unit (GPU) is much more powerful than central processing unit (CPU). We introduce this technology to speed up the Z-Buffer algorithm and get 7 times increase in speed compared with CPU. The results of experiments demonstrate that Z-Buffer algorithm plays well in occlusion and shadow detection combined with high density of point cloud and GPU can speed up the computation significantly.

Influence of Puncture Site on Radial Artery Occlusion After Transradial Coronary Intervention.

PubMed

Bi, Xi-Le; Fu, Xiang-Hua; Gu, Xin-Shun; Wang, Yan-Bo; Li, Wei; Wei, Li-Ye; Fan, Yan-Ming; Bai, Shi-Ru

2016-04-20

The risk of radial artery occlusion (RAO) needs particular attention in transradial intervention (TRI). Therefore, reducing vascular occlusion has an important clinical significance. The aim of this study was to determine the appropriate puncture site during TRI through comparing the occurrence of RAO between the different puncture sites to reduce the occurrence of RAO after TRI. We prospectively assessed the occurrence of RAO in 606 consecutive patients undergoing TRI. Artery occlusion was evaluated with Doppler ultrasound in 2 days and 1 year after the intervention. Risk factors for RAO were evaluated using a multivariate model analysis. Of the 606 patients, the RAO occurred in 56 patients. Compared with TRI at 2-5 cm away from the radius styloid process, the odds ratio (OR) for occlusion risk at 0 cm and 1 cm were 9.65 (P = 0.033) and 8.90 (P = 0.040), respectively. The RAO occurred in the ratio of the arterial diameter to the sheath diameter ≤1 (OR = 2.45, P = 0.004). Distal puncture sites (0-1 cm away from the radius styloid process) can lead to a higher rate of RAO. ClinicalTrials.gov, NCT01979627; https://clinicaltrials.gov/ct2/show/NCT01979627?term = NCT01979627 and rank = 1.

Amputee skin condition: occlusion, stratum corneum hydration and free amino acid levels.

PubMed

Visscher, Marty O; Robinson, Marisa; Fugit, Benetta; Rosenberg, Richard J; Hoath, Steven B; Randall Wickett, R

2011-03-01

Patients with a prosthetic limb report negative skin effects, including irritation, rash and chafing, which can lead to infection, discomfort and reduced wear time to significantly impact normal activities. The aims were to examine the epidermal integrity (transepidermal water loss, TEWL), stratum corneum (SC) hydration [moisture accumulation rate (MAT)], friction and biomechanical properties in active below the knee amputees and to determine the effects of an inert sock liner on skin condition. The liner reduced hydration, TEWL and friction and increased elasticity versus the amputee's conventional skin care methods. Residual limb TEWL was increased and MAT was reduced versus the contralateral normal skin. In a second study, we hypothesized that complete occlusion would decrease free amino acids (FAA) and quantified them by high performance liquid chromatography in an adult volar forearm model. Occlusion with a water vapor impermeable wet dressing led to increased TEWL, erythema and dryness and reduced MAT versus normal skin, comparable to the results in the amputees. The FAA levels were significantly reduced for the occluded sites. The results suggest that residual limb occlusion in amputees may block the formation of FAA in the upper SC. Therapies based on replacement of water binding FAAs, may alleviate the consequences of long-term occlusion.

Venous sinus occlusive disease: MR findings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuh, W.T.C.; Simonson, T.M.; Tali, E.T.

1994-02-01

To study MR patterns of venous sinus occlusive disease and to relate them to the underlying pathophysiology by comparing the appearance and pathophysiologic features of venous sinus occlusive disease with those of arterial ischemic disease. The clinical data and MR examinations of 26 patients with venous sinus occlusive disease were retrospectively reviewed with special attention to mass effect, hemorrhage, and T2-weighted image abnormalities as well as to abnormal parenchymal, venous, or arterial enhancement after intravenous gadopentetate dimeglumine administration. Follow-up studies when available were evaluated for atrophy, infraction, chronic mass effect, and hemorrhage. Mass effect was present in 25 of 26more » patients. Eleven of the 26 had mass effect without abnormal signal on T2-weighted images. Fifteen patients had abnormal signal on T2-weighted images, but this was much less extensive than the degree of brain swelling in all cases. No patient showed abnormal parenchymal or arterial enhancement. Abnormal venous enhancement was seen in 10 of 13 patients who had contrast-enhanced studies. Intraparenchymal hemorrhage was seen in nine patients with high signal on T2-weighted images predominantly peripheral to the hematoma in eight. Three overall MR patterns were observed in acute sinus thrombosis: (1) mass effect without associated abnormal signal on T2-weighted images, (2) mass effect with associated abnormal signal on T2-weighted images and/or ventricular dilatation that may be reversible, and (3) intraparenchymal hematoma with surrounding edema. MR findings of venus sinus occlusive disease are different from those of arterial ischemia and may reflect different underlying pathophysiology. In venous sinus occlusive disease, the breakdown of the blood-brain barrier (vasogenic edema and abnormal parenchymal enhancement) does not always occur, and brain swelling can persist up to 2 years with or without abnormal signal on T2-weighted images. 34 refs., 5 figs.« less

Compliance with the prescribed occlusion treatment for amblyopia.

PubMed

Vagge, Aldo; Nelson, Leonard B

2017-09-01

The present review article is an update on the current evidence about compliance to the prescribed occlusion treatment for amblyopia. In particular, the authors focus on the predictors and causes of noncompliance and possible interventions to increase it. Compliance with prescribed occlusion treatment is often challenging. Reported rates of compliance range widely from 49% to 87%. Objective monitoring of occlusion has opened up new research opportunities and allow the design of effective therapeutic regimens. Also, predictors and causes of noncompliance have been investigated and their knowledge may help the clinician to improved compliance with prescribed occlusion treatment for amblyopia. Although many of the studies assessing the effectiveness of interventions to increase compliance to patching treatment for amblyopia have many limitations, evidences support that use of educational supports, parents, and patient understanding on the importance of patching and written information should be considered to increase compliance with patching.

Temporo-mandibular joint condylectomy and its effect over occlusion in cats: cadaveric study.

PubMed

El-Warrak, A O; Ferrer, G A; Lanthier, T; Loureiro Silva, B; El-Warrak, L O

2011-03-01

To determine the effect of unilateral condylectomy on dental occlusion in cats. Twelve feline cadaver heads were randomly submitted to either a right or left unilateral condylectomy of the temporo-mandibular joint. The distance between the mandibular and maxillary canine tooth was measured before (B0) and after the unilateral condylectomy (P0). A right or left latero--lateral standardised force (4 N) was applied to the mandibular mentus area before and after the surgical procedure. These measurements were analysed with a linear model for repeated measures. The comparative analysis between pre- and postsurgical values indicated no significant variation in teeth displacement following condylectomy between B0 and P0 measurements. Statistically significant differences were detected after either left or right condylectomy with respect to all measurements after application of the standardised forces. Occlusion changes are significant when comparing bites before and after surgery. Unilateral condylectomy causes a significant increase in latero-lateral amplitude of jaw movement which might clinically affect feline dental occlusion. Clinical studies are required to determine the effect of unilateral condylectomies on mastication and dental occlusion in feline patients. © 2011 British Small Animal Veterinary Association.

Nicotinamide attenuates the ischemic brain injury-induced decrease of Akt activation and Bad phosphorylation.

PubMed

Koh, Phil-Ok

2011-07-08

Nicotinamide protects cortical neuronal cells against cerebral ischemic injury through activation of various cytoprotective mechanisms. Here, this study confirmed the neuroprotective effects of nicotinamide in focal cerebral ischemic injury and investigated whether nicotinamide modulates a crucial survival pathway, Akt and its downstream targets. Adult male rats were treated with vehicle or nicotinamide (500 mg/kg) 2h after the onset of middle cerebral artery occlusion (MCAO). Brains were collected 24h after MCAO and infarct volumes were analyzed. Nicotinamide significantly reduced the infarct volume in the cerebral cortex. Potential activation was measured by phosphorylation of PDK1 at Ser(241), Akt at Ser(473), and Bad at Ser(136) using Western blot analysis. Nicotinamide prevented the injury-induced decrease of pPDK1, pAkt, and pBad levels. 14-3-3 levels were not different between vehicle- and nicotinamide-treated animals. However, pBad and 14-3-3 interaction levels decreased during MCAO, but were maintained in the presence of nicotinamide, compared to levels in control animals. These findings suggest that nicotinamide attenuates cell death due to focal cerebral ischemic injury and that neuroprotective effects are mediated through the Akt signaling pathway, thus enhancing neuronal survival. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

VEGF attenuated increase of outward delayed-rectifier potassium currents in hippocampal neurons induced by focal ischemia via PI3-K pathway.

PubMed

Wu, K W; Yang, P; Li, S S; Liu, C W; Sun, F Y

2015-07-09

We recently indicated that the vascular endothelial growth factor (VEGF) protects neurons against hypoxic death via enhancement of tyrosine phosphorylation of Kv1.2, an isoform of the delayed-rectifier potassium channels through activation of the phosphatidylinositol 3-kinase (PI3-K) signaling pathway. The present study investigated whether VEGF could attenuate ischemia-induced increase of the potassium currents in the hippocampal pyramidal neurons of rats after ischemic injury. Adult male Sprague-Dawley rats were subjected to transient middle cerebral artery occlusion (MCAO) to induce brain ischemia. The whole-cell patch-clamp technique was used to record the potassium currents of hippocampal neurons in brain slices from the ischemically injured brains of the rats 24h after MCAO. We detected that transient MCAO caused a significant increase of voltage-gated potassium currents (Kv) and outward delayed-rectifier potassium currents (IK), but not outward transient potassium currents (IA), in the ipsilateral hippocampus compared with the sham. Moreover, we found that VEGF could acutely, reversibly and voltage-dependently inhibit the ischemia-induced IK increase. This inhibitory effect of VEGF could be completely abolished by wortmannin, an inhibitor of PI3-K. Our data indicate that VEGF attenuates the ischemia-induced increase of IK via activation of the PI3-K signaling pathway. Published by Elsevier Ltd.

Automated vision occlusion-timing instrument for perception-action research.

PubMed

Brenton, John; Müller, Sean; Rhodes, Robbie; Finch, Brad

2018-02-01

Vision occlusion spectacles are a highly valuable instrument for visual-perception-action research in a variety of disciplines. In sports, occlusion spectacles have enabled invaluable knowledge to be obtained about the superior capability of experts to use visual information to guide actions within in-situ settings. Triggering the spectacles to occlude a performer's vision at a precise time in an opponent's action or object flight has been problematic, due to experimenter error in using a manual buttonpress approach. This article describes a new laser curtain wireless trigger for vision occlusion spectacles that is portable and fast in terms of its transmission time. The laser curtain can be positioned in a variety of orientations to accept a motion trigger, such as a cricket bowler's arm that distorts the lasers, which then activates a wireless signal for the occlusion spectacles to change from transparent to opaque, which occurs in only 8 ms. Results are reported from calculations done in an electronics laboratory, as well as from tests in a performance laboratory with a cricket bowler and a baseball pitcher, which verified this short time delay before vision occlusion. In addition, our results show that occlusion consistently occurred when it was intended-that is, near ball release and during mid-ball-flight. Only 8% of the collected data trials were unusable. The laser curtain improves upon the limitations of existing vision occlusion spectacle triggers, indicating that it is a valuable instrument for perception-action research in a variety of disciplines.

Occlusion of Sulfate-Based Diblock Copolymer Nanoparticles within Calcite: Effect of Varying the Surface Density of Anionic Stabilizer Chains.

PubMed

Ning, Yin; Fielding, Lee A; Ratcliffe, Liam P D; Wang, Yun-Wei; Meldrum, Fiona C; Armes, Steven P

2016-09-14

Polymerization-induced self-assembly (PISA) offers a highly versatile and efficient route to a wide range of organic nanoparticles. In this article, we demonstrate for the first time that poly(ammonium 2-sulfatoethyl methacrylate)-poly(benzyl methacrylate) [PSEM-PBzMA] diblock copolymer nanoparticles can be prepared with either a high or low PSEM stabilizer surface density using either RAFT dispersion polymerization in a 2:1 v/v ethanol/water mixture or RAFT aqueous emulsion polymerization, respectively. We then use these model nanoparticles to gain new insight into a key topic in materials chemistry: the occlusion of organic additives into inorganic crystals. Substantial differences are observed for the extent of occlusion of these two types of anionic nanoparticles into calcite (CaCO3), which serves as a suitable model host crystal. A low PSEM stabilizer surface density leads to uniform nanoparticle occlusion within calcite at up to 7.5% w/w (16% v/v), while minimal occlusion occurs when using nanoparticles with a high PSEM stabilizer surface density. This counter-intuitive observation suggests that an optimum anionic surface density is required for efficient occlusion, which provides a hitherto unexpected design rule for the incorporation of nanoparticles within crystals.

On the relevance of "ideal" occlusion concepts for incisor inclination target definition.

PubMed

Knösel, Michael; Jung, Klaus

2011-11-01

The concept of "ideal" occlusion in harmony with craniofacial structures is often proposed as an ultimate goal of orthodontic treatment. The aim of this study was to assess the impact of slight variations in posterior occlusion and the history of straight-wire orthodontic treatment on the predictability of incisor inclination and third-order angles. Axial incisor inclinations, third-order angles, and craniofacial relationships were assessed on lateral headfilms and corresponding dental casts of 75 healthy white subjects, 16 to 26 years old, selected by the general inclusion criterion of a good interincisal relationship. Four groups were formed: group A (n = 17), Angle Class I occlusion subjects with no orthodontic treatment; group B (n = 20), Angle Class I occlusion subjects treated with standardized straight-wire orthodontics; group C (n = 20), up to a half-cusp distal occlusion after straight-wire treatment; and group D (n = 18), up to a half-cusp distal occlusion and no orthodontic treatment. Regression analysis was used to insert predictor angles into selected regression equations of the subjects with "ideal" occlusion, and the absolute differences between predicted and observed response angles were determined. Small differences in incisor inclination were found between subjects with "ideal" occlusion and those who slightly deviated from "ideal" with a mild occlusion of the Angle Class II category. Posterior occlusion was not relevant to the validity of the vast majority of predictor-response pairs. Straight-wire treatment produced incisor inclination that was slightly protruded compared with subjects who had good natural occlusion. The "ideal" posterior occlusion concepts as a general orthodontic treatment goal should be reconsidered. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Extravasal occlusion of large vessels with titanic clips: efficiency, indications, and contraindications.

PubMed

Vasilenko, Yu V; Kim, A I; Kotov, S A

2002-11-01

The mechanism of extravasal occlusion of blood vessels with titanic clips "Atrauclip" and "Ligaclip extra" was studied in order to reveal indications and contraindications to their use. Occlusion with the clips of both types was ineffective in vessels with a diameter of >7.0 mm. Arteritis or the presence of an intravascular occlusion facility in the vessel were also the contraindications for clip occlusion. In overcases the procedure of occlusion with titanic clips was efficient and atraumatic.

[Neuroprotective activity of the proline-containing dipeptide noopept on the model of brain ischemia induced by the middle cerebral artery occlusion].

PubMed

Gavrilova, S A; Us, K S; Ostrovskaia, R U; Koshelev, V B

2006-01-01

The influence of noopept (N-phenylacetyl-L-prolylglycine ethyl ester, GVS-111) on the extent of ischemic cortical stroke was investigated in experiments on white mongrel male rats with ischemia induced by a combination of the middle cerebral artery occlusion with ipsilateral common carotid artery ligation. Animals were treated with noopept (0.5 mg/kg, i.p.) according to the following schedule: 15 min and 2, 24, and 48 h after the occlusion. Test rats were decapitated 72 h after occlusion, brains were extracted and frozen, and thin brain slices were stained with 2,3,5-triphenyltetrazolium chloride. The slices were scanned and processed using Auc 1 computer program, which estimates the percentage of damaged area relative to that of the whole ipsilateral hemisphere. The conditions of coagulation the distal segment of middle cerebral artery were selected, which caused necrosis localized in the fronto-parietal and dorso-lateral regions of the brain cortex without any damage of subcortical structures. The extent of the brain damage in control group (treated by saline) was 18.6%, while that in the group treated with noopept was 12.2%, thus demonstrating a decrease in the infarction area by 34.5% (p < 05). The data on noopept efficacy on the model of the extensive ischemic injury of brain cortex show that this drug has good prospects for use in the neuroprotective treatment of stroke.

The Value of 3D Printing Models of Left Atrial Appendage Using Real-Time 3D Transesophageal Echocardiographic Data in Left Atrial Appendage Occlusion: Applications toward an Era of Truly Personalized Medicine.

PubMed

Liu, Peng; Liu, Rijing; Zhang, Yan; Liu, Yingfeng; Tang, Xiaoming; Cheng, Yanzhen

The objective of this study was to assess the clinical feasibility of generating 3D printing models of left atrial appendage (LAA) using real-time 3D transesophageal echocardiogram (TEE) data for preoperative reference of LAA occlusion. Percutaneous LAA occlusion can effectively prevent patients with atrial fibrillation from stroke. However, the anatomical structure of LAA is so complicated that adequate information of its structure is essential for successful LAA occlusion. Emerging 3D printing technology has the demonstrated potential to structure more accurately than conventional imaging modalities by creating tangible patient-specific models. Typically, 3D printing data sets are acquired from CT and MRI, which may involve intravenous contrast, sedation, and ionizing radiation. It has been reported that 3D models of LAA were successfully created by the data acquired from CT. However, 3D printing of the LAA using real-time 3D TEE data has not yet been explored. Acquisition of 3D transesophageal echocardiographic data from 8 patients with atrial fibrillation was performed using the Philips EPIQ7 ultrasound system. Raw echocardiographic image data were opened in Philips QLAB and converted to 'Cartesian DICOM' format and imported into Mimics® software to create 3D models of LAA, which were printed using a rubber-like material. The printed 3D models were then used for preoperative reference and procedural simulation in LAA occlusion. We successfully printed LAAs of 8 patients. Each LAA costs approximately CNY 800-1,000 and the total process takes 16-17 h. Seven of the 8 Watchman devices predicted by preprocedural 2D TEE images were of the same sizes as those placed in the real operation. Interestingly, 3D printing models were highly reflective of the shape and size of LAAs, and all device sizes predicted by the 3D printing model were fully consistent with those placed in the real operation. Also, the 3D printed model could predict operating difficulty and the

Occlusal tooth wear in Chinese adults with shortened dental arches.

PubMed

Zhang, Q; Witter, D J; Bronkhorst, E M; Bartlett, D W; Creugers, N H J

2014-02-01

To assess associations between occlusal tooth wear and shortened dental arches (SDA) in Chinese 40 years and older subjects. From a sample of 1462 urban and rural adults, those presenting with SDA (n = 150) were compared with a control group of 65 randomly selected subjects with complete dentitions (CDA). Occlusal wear was assessed using a modified Smith and Knight index - the occlusal tooth wear index (OWTI) - and analysed using multivariate (logistic) regression. There was no significant effect from SDA on severe occlusal wear (OTWI score 3 or 4: OR = 2.016; 95% CI = 0.960-4.231; P = 0.064). Higher age was associated with severe occlusal wear (P values ≤0.007) and with higher mean OTWI scores; urban had less often severe occlusal wear than rural residents (OR = 0.519; P = 0.008). Higher mean OTWI scores were associated with rural residents, except for anterior teeth. Females had lower mean OTWI score for anterior teeth (effect = -0.153; P = 0.030). Premolars in SDA had higher mean OTWI scores compared with those in CDA (effect = +0.213; P = 0.006). In SDA, more posterior occluding pairs (POPs) were associated with lower mean OTWI sores for anterior teeth (effect: -0.158; P = 0.008) and higher scores for molars (effect: +0.249, P = 0.003). Subjects with SDA or CDA presented comparable occlusal wear, but premolars in SDA tend to have higher probability for having occlusal wear. Fewer numbers of POPs were associated with more wear in anterior teeth. © 2013 John Wiley & Sons Ltd.

The importance of regulation of blood glucose levels through activation of peripheral 5'-AMP-activated protein kinase on ischemic neuronal damage.

PubMed

Harada, Shinichi; Fujita-Hamabe, Wakako; Tokuyama, Shogo

2010-09-10

5'-AMP-activated protein kinase (AMPK) is a serine/threonine kinase that plays a key role in energy homeostasis. Recently, it was reported that centrally activated AMPK is involved in the development of ischemic neuronal damage, while the effect of peripherally activated AMPK on ischemic neuronal damage is not known. In addition, we have previously reported that the development of post-ischemic glucose intolerance could be one of the triggers for the aggravation of neuronal damage. In this study, we focused on effect of activation of peripheral or central AMPK on the development of ischemic neuronal damage. Male ddY mice were subjected to 2 h of middle cerebral artery occlusion (MCAO). Neuronal damage was estimated by histological and behavioral analysis after MCAO. In the liver and skeletal muscle, AMPK activity was not affected by MCAO. But, application of intraperitoneal metformin (250 mg/kg), an AMPK activator, significantly suppressed the development of post-ischemic glucose intolerance and ischemic neuronal damage without alteration of central AMPK activity. On the other hand, application of intracerebroventricular metformin (25, 100 microg/mouse) significantly exacerbated the development of neuronal damage observed on day 1 after MCAO, in a dose-dependent manner. These effects were significantly blocked by compound C, a specific AMPK inhibitor. These results suggest that central AMPK was activated by ischemic stress per se, however, peripheral AMPK was not altered. Furthermore, the regulation of post-ischemic glucose intolerance by activation of peripheral AMPK is of assistance for the suppression of cerebral ischemic neuronal damage. 2010 Elsevier B.V. All rights reserved.

Ebselen attenuates oxidative DNA damage and enhances its repair activity in the thalamus after focal cortical infarction in hypertensive rats.

PubMed

He, Meixia; Xing, Shihui; Yang, Bo; Zhao, Liqun; Hua, Haiying; Liang, Zhijian; Zhou, Wenliang; Zeng, Jinsheng; Pei, Zhong

2007-11-21

Oxidative DNA damage has been proposed to be a major contributor to focal cerebral ischemic injury. However, little is known about the role of oxidative DNA damage in remote damage secondary to the primary infarction. In the present study, we investigated oxidative damage within the ventroposterior nucleus (VPN) after distal middle cerebral artery occlusion (MCAO) in hypertensive rats. We also examined the possible protective effect of ebselen, one glutathione peroxidase mimic, on delayed degeneration in the VPN after distal MCAO. Neuronal damage in the ipsilateral VPN was examined by Nissl staining. Oxidative DNA damage and base repair enzyme activity were assessed by analyzing immunoreactivity of 8-hydroxy-2'-deoxyguanosine (8-ohdG) and 8-oxoguanine DNA glycosylase (OGG1), respectively. The number of intact neurons in the ipsilateral VPN decreased by 52% compared to the contralateral side in ischemia group 2 weeks after distal cerebral cortical infarction. The immunoreactivity of 8-ohdG significantly increased while OGG1 immunoreactivity significantly decreased in the ipsilateral VPN 2 weeks after distal cortical infarction (all p<0.01). Compared with vehicle treatment, ebselen significantly attenuated the neuron loss, ameliorated ischemia-induced increase in 8-ohdG level as well as decrease in OGG1 level within the ipsilateral VPN (all p<0.01). OGG1 was further demonstrated to mainly express in neurons. These findings strongly suggest that oxidative DNA damage may be involved in the delayed neuronal death in the VPN region following distal MCAO. Furthermore, ebselen protects against the delayed damage in the VPN when given at 24 h following distal MCAO.

Pulmonary veno-occlusive disease and pulmonary capillary hemangiomatosis.

PubMed

Ortiz-Bautista, Carlos; Hernández-González, Ignacio; Escribano-Subías, Pilar

2017-03-22

Pulmonary veno-occlusive disease is a rare cause of pulmonary hypertension which is part, together with pulmonary capillary hemangiomatosis, of the special designation (subgroup 1') within pulmonary hypertension group 1 in the latest classification of the pulmonary hypertension World Symposium. Recent discovery that gene mutations in eukaryotic translation initiation factor 2 alpha kinase 4 (EIF2AK4) are responsible for inherited forms of pulmonary veno-occlusive disease has changed the role of genetic testing, acquiring relevant importance in the diagnosis of these patients. Despite the advances in genetic, cellular and molecular basis knowledge in the last decade, pulmonary veno-occlusive disease remains as a rare aetiology of pulmonary hypertension without any effective medical treatment approved and poor outcomes. This document aims to review the advances occurred in the understanding of pulmonary veno-occlusive disease in the last years. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

Opposite effects of the gap junction blocker octanol on focal cerebral ischemia occluded for different durations.

PubMed

Ding, Wenting; Zhou, Lequan; Liu, Wei; Guan, Li; Li, Xiaoying; Liu, Haimei; Yan, Fuman; Xu, Jinwen; Zeng, Weiyong; Qiu, Min

2014-06-01

Protectants and executioners have been demonstrated to be used by gap junctions in focal cerebral ischemia. Certain researchers hypothesized that the opposite role of gap junctions may be associated with the injury extent, which has been demonstrated to be highly correlated with occlusion duration. In order to examine this hypothesis directly, the effects of octanol, a frequently used drug, were examined to investigate the role of gap junctions, in rats following middle cerebral artery occlusion (MCAO) for 30 min/2 h and 24 h reperfusion, respectively. Octanol significantly reduced the infarct volume following 2 h of occlusion concomitant with lower neurological deficits, whereas it enlarged the infarct volume following 30 min of occlusion. Consistently, octanol attenuated the number of transferase dUTP nick-end labeling (TUNEL) positive neurons in the hippocampal CA1 region following 2 h of occlusion, while opposite effects were observed for 30 min of occlusion. Further immunohistochemical studies demonstrated that the expression of B-cell leukemia-2 (Bcl-2, anti-apoptotic protein) was upregulated and that Bcl-2-associated X (Bax, proapoptotic protein) was downregulated following 2 h of occlusion in the octanol group compared with the ischemic group. Conversely, octanol downregulated the expression of the Bcl-2 protein concomitant with increased Bax protein following 30 min of occlusion. These results indicated that the gap junction blocker octanol can protect against ischemic injury following long-term occlusion, however, can aggravate ischemic injury following short-term occlusion.

A change in humidification system can eliminate endotracheal tube occlusion.

PubMed

Doyle, Alex; Joshi, Manasi; Frank, Peter; Craven, Thomas; Moondi, Parvez; Young, Peter

2011-12-01

Inadequate airway humidification can result in endotracheal tube occlusion. There is evidence that heat and moisture exchangers (HMEs) are more prone to endotracheal tube occlusion than heated humidifiers (HHs) that contain a heated wire circuit. We aimed to compare the incidence of endotracheal tube occlusion while introducing a new dual-heated wire circuit HH in place of an established hydrophobic HME. This was a prospective observational study. All patients who required intubation were included in our analysis. Univariate statistical analysis was performed using a Fisher exact test. P < .05 was considered statistically significant. There were 158 patients in the HME group and 88 patients in the HH group. The incidence of endotracheal tube occlusion was 5.7% in the HME group and 0% in the HH group. Statistical analysis revealed a significant difference between the 2 groups (P = .02). In light of this finding, we changed our practice to provide humidification exclusively by HH. In the subsequent 18-month period, there were no further episodes of endotracheal tube occlusion. Our study demonstrates that there is a significant increase in the incidence of endotracheal tube occlusion when using a hydrophobic HME compared with an HH and that using a dual-heated wire circuit HH can eliminate endotracheal tube occlusion. Copyright © 2011 Elsevier Inc. All rights reserved.

Does partial occlusion promote normal binocular function?

PubMed

Li, Jingrong; Thompson, Benjamin; Ding, Zhaofeng; Chan, Lily Y L; Chen, Xiang; Yu, Minbin; Deng, Daming; Hess, Robert F

2012-10-03

There is growing evidence that abnormal binocular interactions play a key role in the amblyopia syndrome and represent a viable target for treatment interventions. In this context the use of partial occlusion using optical devices such as Bangerter filters as an alternative to complete occlusion is of particular interest. The aims of this study were to understand why Bangerter filters do not result in improved binocular outcomes compared to complete occlusion, and to compare the effects of Bangerter filters, optical blur and neutral density (ND) filters on normal binocular function. The effects of four strengths of Bangerter filters (0.8, 0.6, 0.4, 0.2) on letter and vernier acuity, contrast sensitivity, stereoacuity, and interocular suppression were measured in 21 observers with normal vision. In a subset of 14 observers, the partial occlusion effects of Bangerter filters, ND filters and plus lenses on stereopsis and interocular suppression were compared. Bangerter filters did not have graded effect on vision and induced significant disruption to binocular function. This disruption was greater than that of monocular defocus but weaker than that of ND filters. The effect of the Bangerter filters on stereopsis was more pronounced than their effect on monocular acuity, and the induced monocular acuity deficits did not predict the induced deficits in stereopsis. Bangerter filters appear to be particularly disruptive to binocular function. Other interventions, such as optical defocus and those employing computer generated dichoptic stimulus presentation, may be more appropriate than partial occlusion for targeting binocular function during amblyopia treatment.

Occlusal accommodation and mouthguards for prevention of orofacial trauma.

PubMed

Geary, Julian Lindsay; Clifford, Thomas Joseph; Kinirons, Martin James

2009-01-01

The aim of this study was to investigate the effect of two types of occlusal accommodation on the arch separation in centric and eccentric arch positions and to assess the opposing tooth contacts in professionally made, thermoformed sports mouthguards. Maxillary and mandibular alginate impressions, a wax interocclusal record of centric occlusion together with maxillary/condylar face-bow registrations, were recorded clinically for 10 undergraduate dental students who are sports activist volunteers of the School of Medicine and Dentistry, Queen's University Belfast. Two ethylene vinyl acetate thermoformed maxillary mouthguards were made for each player (N = 20) using a standardised procedure. Ten mouthguards served both as the control (i.e. the non-accommodated) group and also the accommodated, occlusally 'imprinted' group. The other 10 mouthguards served as the accommodated, occlusally 'ground' group. Casts were articulated, each non-accommodated and accommodated mouthguard was seated and the extent of the interocclusal opening was recorded in all three arch relationships. The number of mouthguard and mandibular tooth contacts were also recorded in each position. The increased vertical occlusal dimension that was found in the presence of non-accommodated mouthguards equated to the full-sheet thickness of the material that was used to form the mouthguards. Only mouthguards accommodated by grinding retained high levels of occlusal contact in all arch relationships that were tested. Within the limitations of this study, the modification of the occlusal surface made by flat grinding reduced the arch separation in eccentric movements and increased the opposing tooth contacts in custom-made mouthguards. This may contribute to increased comfort, compliance and the protective effect of these appliances thus resulting in a reduction of injuries to the teeth, arches and soft tissues.

Occlusion-amblyopia following high dose oral levodopa combined with part time patching

PubMed Central

Kothari, Mihir

2014-01-01

Part time occlusion therapy is not reported to cause occlusion (reverse) amblyopia. However, when combined with high dose oral levodopa, an increase in the plasticity of the visual cortex can lead to occlusion amblyopia. In this case report, we describe a six year old child who developed occlusion amblyopia following part time patching combined with oral levodopa. PMID:23571255

Occlusion-amblyopia following high dose oral levodopa combined with part time patching.

PubMed

Kothari, Mihir

2014-12-01

Part time occlusion therapy is not reported to cause occlusion (reverse) amblyopia. However, when combined with high dose oral levodopa, an increase in the plasticity of the visual cortex can lead to occlusion amblyopia. In this case report, we describe a six year old child who developed occlusion amblyopia following part time patching combined with oral levodopa.

Combined Central Retinal Vein and Branch Retinal Artery Occlusion Post Intense Physical Activity.

PubMed

Coca, Mircea; Tecle, Nahom; Amde, Wendewessen; Mehta, Ankur

2017-08-23

We report a case of combined central retinal vein occlusion and branch retinal artery occlusion. A previously healthy 47-year-old male presented with decreased vision in the right eye after completing a half marathon. A fundus exam and retinal imaging revealed a combined central retinal vein and branch retinal artery occlusion. In the present report, we review the literature and discuss the possible mechanisms behind combined retinal vessel occlusions. To our knowledge, this is the first reported case of combined central retinal vein occlusion and branch retinal artery occlusion following intense exercise.

Combined Central Retinal Vein and Branch Retinal Artery Occlusion Post Intense Physical Activity

PubMed Central

Tecle, Nahom; Amde, Wendewessen; Mehta, Ankur

2017-01-01

We report a case of combined central retinal vein occlusion and branch retinal artery occlusion. A previously healthy 47-year-old male presented with decreased vision in the right eye after completing a half marathon. A fundus exam and retinal imaging revealed a combined central retinal vein and branch retinal artery occlusion. In the present report, we review the literature and discuss the possible mechanisms behind combined retinal vessel occlusions. To our knowledge, this is the first reported case of combined central retinal vein occlusion and branch retinal artery occlusion following intense exercise. PMID:29067224

Severe hypertriglyceridemia does not protect from ischemic brain injury in gene-modified hypertriglyceridemic mice.

PubMed

Chen, Yong; Liu, Ping; Qi, Rong; Wang, Yu-Hui; Liu, George; Wang, Chun

2016-05-15

Hypertriglyceridemia (HTG) is a weak risk factor in primary ischemic stroke prevention. However, clinical studies have found a counterintuitive association between a good prognosis after ischemic stroke and HTG. This "HTG paradox" requires confirmation and further explanation. The aim of this study was to experimentally assess this paradox relationship using the gene-modified mice model of extreme HTG. We first used the human Apolipoprotein CIII transgenic (Tg-ApoCIII) mice and non-transgenic (Non-Tg) littermates to examine the effect of HTG on stroke. To our surprise, infarct size, neurological deficits, brain edema, BBB permeability, neuron density and lipid peroxidation were the same in Tg-ApoCIII mice and Non-Tg mice after temporary middle cerebral artery occlusion (tMCAO). In the late phase (21 days after surgery), no differences were found in brain atrophy, neurological dysfunctions, weight and mortality between the two groups. To confirm the results in Tg-ApoCIII mice, Glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1(GPIHBP1) knockout mice, another severe HTG mouse model, were used and yielded similar results. Our study demonstrates for the first time that extreme HTG does not affect ischemic brain injuries in the tMCAO mouse model, indicating that the association between HTG and good outcomes after ischemic stroke probably represents residual unmeasured confounding. Further clinical and prospective population-based studies are needed to explore variables that contribute to the paradox. Copyright © 2016 Elsevier B.V. All rights reserved.

Inhibition of Cathepsin B Alleviates Secondary Degeneration in Ipsilateral Thalamus After Focal Cerebral Infarction in Adult Rats.

PubMed

Zuo, Xialin; Hou, Qinghua; Jin, Jizi; Zhan, Lixuan; Li, Xinyu; Sun, Weiwen; Lin, Kunqin; Xu, En

2016-09-01

Secondary degeneration in areas beyond ischemic foci can inhibit poststroke recovery. The cysteine protease Cathepsin B (CathB) regulates cell death and intracellular protein catabolism. To investigate the roles of CathB in the development of secondary degeneration in the ventroposterior nucleus (VPN) of the ipsilateral thalamus after focal cerebral infarction, infarct volumes, immunohistochemistry and immunofluorescence, and Western blotting analyses were conducted in a distal middle cerebral artery occlusion (dMCAO) stroke model in adult rats. We observed marked neuron loss and gliosis in the ipsilateral thalamus after dMCAO, and the expression of CathB and cleaved caspase-3 in the VPN was significantly upregulated; glial cells were the major source of CathB. Although it had no effect on infarct volume, delayed intracerebroventricular treatment with the membrane-permeable CathB inhibitor CA-074Me suppressed the expression of CathB and cleaved caspase-3 in ipsilateral VPN and accordingly alleviated the secondary degeneration. These data indicate that CathB mediates a novel mechanism of secondary degeneration in the VPN of the ipsilateral thalamus after focal cortical infarction and suggest that CathB might be a therapeutic target for the prevention of secondary degeneration in patients after stroke. © 2016 American Association of Neuropathologists, Inc. All rights reserved.

Extrapolation of vertical target motion through a brief visual occlusion.

PubMed

Zago, Myrka; Iosa, Marco; Maffei, Vincenzo; Lacquaniti, Francesco

2010-03-01

It is known that arbitrary target accelerations along the horizontal generally are extrapolated much less accurately than target speed through a visual occlusion. The extent to which vertical accelerations can be extrapolated through an occlusion is much less understood. Here, we presented a virtual target rapidly descending on a blank screen with different motion laws. The target accelerated under gravity (1g), decelerated under reversed gravity (-1g), or moved at constant speed (0g). Probability of each type of acceleration differed across experiments: one acceleration at a time, or two to three different accelerations randomly intermingled could be presented. After a given viewing period, the target disappeared for a brief, variable period until arrival (occluded trials) or it remained visible throughout (visible trials). Subjects were asked to press a button when the target arrived at destination. We found that, in visible trials, the average performance with 1g targets could be better or worse than that with 0g targets depending on the acceleration probability, and both were always superior to the performance with -1g targets. By contrast, the average performance with 1g targets was always superior to that with 0g and -1g targets in occluded trials. Moreover, the response times of 1g trials tended to approach the ideal value with practice in occluded protocols. To gain insight into the mechanisms of extrapolation, we modeled the response timing based on different types of threshold models. We found that occlusion was accompanied by an adaptation of model parameters (threshold time and central processing time) in a direction that suggests a strategy oriented to the interception of 1g targets at the expense of the interception of the other types of tested targets. We argue that the prediction of occluded vertical motion may incorporate an expectation of gravity effects.

Age-related differences in interferon regulatory factor-4 and -5 signaling in ischemic brains of mice.

PubMed

Zhao, Shou-Cai; Wang, Chun; Xu, Heng; Wu, Wen-Qian; Chu, Zhao-Hu; Ma, Ling-Song; Zhang, Ying-Dong; Liu, Fudong

2017-11-01

Stroke is a disease that mainly affects the elderly. Since the age-related differences in stroke have not been well studied, modeling stroke in aged animals is clinically more relevant. The inflammatory responses to stroke are a fundamental pathological procedure, in which microglial activation plays an important role. Interferon regulatory factor-5 (IRF5) and IRF4 regulate M1 and M2 activation of macrophages, respectively, in peripheral inflammation; but it is unknown whether IRF5/IRF4 are also involved in cerebral inflammatory responses to stroke and whether age-related differences of the IRF5/IRF4 signaling exist in ischemic brain. Here, we investigated the influences of aging on IRF5/IRF4 signaling and post-stroke inflammation in mice. Both young (9-12 weeks) and aged (18 months) male mice were subjected to middle cerebral artery occlusion (MCAO). Morphological and biochemical changes in the ischemic brains and behavior deficits were assessed on 1, 3, and 7 d post-stroke. After MCAO, the aged mice showed smaller infarct sizes but higher neurological deficits and corner test scores than young mice. Young mice had higher levels of IRF4 and CD206 microglia in the ischemic brains, whereas the aged mice expressed more IRF5 and MHCII microglia. After MCAO, serum pro-inflammatory cytokines (TNF-α, iNOS, IL-6) were more prominently up-regulated in aged mice, whereas serum anti-inflammatory cytokines (TGF-β, IL-4, IL-10) were more prominently up-regulated in young mice. Our results demonstrate that aging has a significant influence on stroke outcomes in mice, which is probably mediated by age-specific inflammatory responses.

Delayed Docosahexaenoic Acid Treatment Combined with Dietary Supplementation of Omega-3 Fatty Acids Promotes Long-Term Neurovascular Restoration After Ischemic Stroke.

PubMed

Pu, Hongjian; Jiang, Xiaoyan; Hu, Xiaoming; Xia, Jinchao; Hong, Dandan; Zhang, Wenting; Gao, Yanqin; Chen, Jun; Shi, Yejie

2016-12-01

Prophylactic dietary intake of omega-3 polyunsaturated fatty acids (n-3 PUFAs) has been shown to remarkably ameliorate ischemic brain injury. However, the therapeutic efficacy of n-3 PUFA administration post-stroke, especially its impact on neurovascular remodeling and long-term neurological recovery, has not been fully characterized thus far. In this study, we investigated the effect of n-3 PUFA supplementation, as well as in combination with docosahexaenoic acid (DHA) injections, on long-term stroke outcomes. Mice were subjected to transient middle cerebral artery occlusion (MCAO) before randomly assigned to four groups to receive the following: (1) low dose of n-3 PUFAs as the vehicle control, (2) intraperitoneal DHA injections, (3) n-3 PUFA dietary supplement, or (4) combined treatment of (2) and (3). Neurological deficits and brain atrophy, neurogenesis, angiogenesis, and glial scar formation were assessed up to 28 days after MCAO. Results revealed that groups 2 and 3 showed only marginal reduction in post-stroke tissue loss and attenuation of cognitive deficits. Interestingly, group 4 exhibited significantly reduced tissue atrophy and improved cognitive functions compared to groups 2 and 3 with just a single treatment. Mechanistically, the combined treatment promoted post-stroke neurogenesis and angiogenesis, as well as reduced glial scar formation, all of which significantly correlated with the improved spatial memory in the Morris water maze. These results demonstrate an effective therapeutic regimen to enhance neurovascular restoration and long-term cognitive recovery in the mouse model of MCAO. Combined post-stroke DHA treatment and n-3 PUFA dietary supplementation thus may be a potential clinically translatable therapy for stroke or related brain disorders.

Effect of Buyang Huanwu decoction on amino acid content in cerebrospinal fluid of rats during ischemic/reperfusion injury.

PubMed

Wang, Lisheng; Huang, Yuwei; Wu, Junhong; Lv, Gengbin; Zhou, Liling; Jia, Jie

2013-12-01

The inhibitory effect of Buyang Huanwu decoction (BYHWD) on ischemic injury has been proven, but it is not clear how amino acid levels in cerebrospinal fluid (CSF) are associated with BYHWD treatment, nor the mechanism by which BYHWD protects the brain from ischemia/reperfusion injury. We investigated the effect of BYHWD on the amino acid content of CSF in rats during ischemia-reperfusion injury. Ischemia was imposed by right middle cerebral artery occlusion (MCAO). CSF was continuously collected from the striatum via brain microdialysis before and after ischemia/reperfusion. We used on-line derivatization combined with high-performance liquid chromatography with fluorescence detection (HPLC-FD) to determine levels of glutamate (Glu), aspartate (Asp), glycine (Gly), taurine (Tau), and γ-aminobutyric acid (GABA) in CSF. The MCAO model displayed an infarct lesion in the ipsilateral hemisphere and nerve injuries, as the left upper limb was unable to extend and turn leftward. Significant increases in excitatory and inhibitory amino acids were observed in the CSF of the ischemic rats relative to the sham-operated group (P<0.01). Treatment with BYHWD reduced the areas of cerebral infarction and improved the neurological behavior scores of rats after MCAO. BYHWD treatment was also associated with a significant decrease in excitatory amino acids and increase in inhibitory amino acids in the CSF. Only the higher dose of BYHWD (20mg/kg) affected all these levels significantly. Attenuated excitatory toxicity and reduced areas of cerebral infarction associated with BYHWD treatment might be due to a protective mechanism induced by BYHWD against ischemia/reperfusion injury. Copyright © 2013 Elsevier B.V. All rights reserved.

Different mechanisms of secondary neuronal damage in thalamic nuclei after focal cerebral ischemia in rats.

PubMed

Dihné, Marcel; Grommes, Christian; Lutzenburg, Michael; Witte, Otto W; Block, Frank

2002-12-01

After focal cerebral ischemia, depending on its localization and extent, secondary neuronal damage may occur that is remote from the initial lesion. In this study differences in secondary damage of the ventroposterior thalamic nucleus (VPN) and the reticular thalamic nucleus (RTN) were investigated with the use of different ischemia models. Transient middle cerebral artery occlusion (MCAO) leads to cortical infarction, including parts of the basal ganglia such as the globus pallidus, and to widespread edema. Photothrombotic ischemia generates pure cortical infarcts sparing the basal ganglia and with only minor edema. Neuronal degeneration was quantified within the ipsilateral RTN and VPN 14 days after ischemia. Glial reactions were studied with the use of immunohistochemistry. MCAO resulted in delayed neuronal cell loss of the ipsilateral VPN and RTN. Glial activation occurred in both nuclei beginning after 24 hours. Photothrombotic ischemia resulted in delayed neuronal cell loss only within the VPN. Even 2 weeks after photothrombotic ischemia, glial activation could only be seen within the VPN. Pure cortical infarcts after photothrombotic ischemia, without major edema and without effects on the globus pallidus of the basal ganglia, only lead to secondary VPN damage that is possibly due to retrograde degeneration. MCAO, which results in infarction of cortex and globus pallidus and which causes widespread edema, leads to secondary damage in the VPN and RTN. Thus, additional RTN damage may be due to loss of protective GABAergic input from the globus pallidus to the RTN or due to the extensive edema. Retrograde degeneration is not possible because the RTN, in contrast to the VPN, has no efferents to the cortex.

Percutaneous intraportal application of adipose tissue-derived mesenchymal stem cells using a balloon occlusion catheter in a porcine model of liver fibrosis.

PubMed

Avritscher, Rony; Abdelsalam, Mohamed E; Javadi, Sanaz; Ensor, Joe; Wallace, Michael J; Alt, Eckhard; Madoff, David C; Vykoukal, Jody V

2013-12-01

To investigate the safety and effectiveness of a novel endovascular approach for therapeutic cell delivery using a balloon occlusion catheter in a large animal model of liver fibrosis. Transcatheter arterial embolization with ethiodized oil (Ethiodol) and ethanol was used to induce liver damage in 11 pigs. Mesenchymal stem cells (MSCs) were harvested from adipose tissue and engineered to express green fluorescent protein (GFP). A balloon occlusion catheter was positioned in the bilateral first-order portal vein branches 2 weeks after embolization to allow intraportal application of MSCs in six experimental animals. MSCs were allowed to dwell for 10 minutes using prolonged balloon inflation. Five control animals received a sham injection of normal saline in a similar fashion. Hepatic venous pressure gradient (HVPG) was measured immediately before necropsy. Specimens from all accessible lobes were obtained with ultrasound-guided percutaneous 18-gauge biopsy 2 hours after cell application. All animals were euthanized within 4 weeks. Fluorescent microscopy was used to assess the presence and distribution of cells. Liver injury and fibrosis were successfully induced in all animals. MSCs (6-10 × 10(7)) were successfully delivered into the portal vein in the six experimental animals. Cell application was not associated with vascular complications. HVPG showed no instances of portal hypertension. GFP-expressing MSCs were visualized in biopsy specimens and were distributed primarily within the sinusoidal spaces; however, 4 weeks after implantation, MSCs could not be identified in histologic specimens. A percutaneous endovascular approach for cell delivery using a balloon occlusion catheter proved safe for intraportal MSC application in a large animal model of liver fibrosis. © 2013 SIR Published by SIR All rights reserved.

5'-adenosine monophosphate-induced hypothermia attenuates brain ischemia/reperfusion injury in a rat model by inhibiting the inflammatory response.

PubMed

Miao, Yi-Feng; Wu, Hui; Yang, Shao-Feng; Dai, Jiong; Qiu, Yong-Ming; Tao, Zhen-Yi; Zhang, Xiao-Hua

2015-01-01

Hypothermia treatment is a promising therapeutic strategy for brain injury. We previously demonstrated that 5'-adenosine monophosphate (5'-AMP), a ribonucleic acid nucleotide, produces reversible deep hypothermia in rats when the ambient temperature is appropriately controlled. Thus, we hypothesized that 5'-AMP-induced hypothermia (AIH) may attenuate brain ischemia/reperfusion injury. Transient cerebral ischemia was induced by using the middle cerebral artery occlusion (MCAO) model in rats. Rats that underwent AIH treatment exhibited a significant reduction in neutrophil elastase infiltration into neuronal cells and matrix metalloproteinase 9 (MMP-9), interleukin-1 receptor (IL-1R), tumor necrosis factor receptor (TNFR), and Toll-like receptor (TLR) protein expression in the infarcted area compared to euthermic controls. AIH treatment also decreased the number of terminal deoxynucleotidyl transferase dUTP nick end labeling- (TUNEL-) positive neuronal cells. The overall infarct volume was significantly smaller in AIH-treated rats, and neurological function was improved. By contrast, rats with ischemic brain injury that were administered 5'-AMP without inducing hypothermia had ischemia/reperfusion injuries similar to those in euthermic controls. Thus, the neuroprotective effects of AIH were primarily related to hypothermia.

Improving prediction of recanalization in acute large-vessel occlusive stroke.

PubMed

Vanacker, P; Lambrou, D; Eskandari, A; Maeder, P; Meuli, R; Ntaios, G; Michel, P

2014-06-01

Recanalization in acute ischemic stroke with large-vessel occlusion is a potent indicator of good clinical outcome. To identify easily available clinical and radiologic variables predicting recanalization at various occlusion sites. All consecutive, acute stroke patients from the Acute STroke Registry and Analysis of Lausanne (2003-2011) who had a large-vessel occlusion on computed tomographic angiography (CTA) (< 12 h) were included. Recanalization status was assessed at 24 h (range: 12-48 h) with CTA, magnetic resonance angiography, or ultrasonography. Complete and partial recanalization (corresponding to the modified Treatment in Cerebral Ischemia scale 2-3) were grouped together. Patients were categorized according to occlusion site and treatment modality. Among 439 patients, 51% (224) showed complete or partial recanalization. In multivariate analysis, recanalization of any occlusion site was most strongly associated with endovascular treatment, including bridging therapy (odds ratio [OR] 7.1, 95% confidence interval [CI] 2.2-23.2), and less so with intravenous thrombolysis (OR 1.6, 95% CI 1.0-2.6) and recanalization treatments performed beyond guidelines (OR 2.6, 95% CI 1.2-5.7). Clot location (large vs. intermediate) and tandem pathology (the combination of intracranial occlusion and symptomatic extracranial stenosis) were other variables discriminating between recanalizers and non-recanalizers. For patients with intracranial occlusions, the variables significantly associated with recanalization after 24 h were: baseline National Institutes of Health Stroke Scale (NIHSS) (OR 1.04, 95% CI 1.02-1.1), Alberta Stroke Program Early CT Score (ASPECTS) on initial computed tomography (OR 1.2, 95% CI 1.1-1.3), and an altered level of consciousness (OR 0.2, 95% CI 0.1-0.5). Acute endovascular treatment is the single most important factor promoting recanalization in acute ischemic stroke. The presence of extracranial vessel stenosis or occlusion decreases

21 CFR 884.5380 - Contraceptive tubal occlusion device (TOD) and introducer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Contraceptive tubal occlusion device (TOD) and... Gynecological Therapeutic Devices § 884.5380 Contraceptive tubal occlusion device (TOD) and introducer. (a) Identification. A contraceptive tubal occlusion device (TOD) and introducer is a device designed to close a...

21 CFR 884.5380 - Contraceptive tubal occlusion device (TOD) and introducer.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Contraceptive tubal occlusion device (TOD) and... Gynecological Therapeutic Devices § 884.5380 Contraceptive tubal occlusion device (TOD) and introducer. (a) Identification. A contraceptive tubal occlusion device (TOD) and introducer is a device designed to close a...

21 CFR 884.5380 - Contraceptive tubal occlusion device (TOD) and introducer.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Contraceptive tubal occlusion device (TOD) and... Gynecological Therapeutic Devices § 884.5380 Contraceptive tubal occlusion device (TOD) and introducer. (a) Identification. A contraceptive tubal occlusion device (TOD) and introducer is a device designed to close a...

21 CFR 884.5380 - Contraceptive tubal occlusion device (TOD) and introducer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Contraceptive tubal occlusion device (TOD) and... Gynecological Therapeutic Devices § 884.5380 Contraceptive tubal occlusion device (TOD) and introducer. (a) Identification. A contraceptive tubal occlusion device (TOD) and introducer is a device designed to close a...

21 CFR 884.5380 - Contraceptive tubal occlusion device (TOD) and introducer.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Contraceptive tubal occlusion device (TOD) and... Gynecological Therapeutic Devices § 884.5380 Contraceptive tubal occlusion device (TOD) and introducer. (a) Identification. A contraceptive tubal occlusion device (TOD) and introducer is a device designed to close a...

Levodopa-carbidopa with occlusion in older children with amblyopia.

PubMed

Bhartiya, Prashant; Sharma, Pradeep; Biswas, Nihar R; Tandon, Radhika; Khokhar, Sudarshan K

2002-12-01

To study the role of levodopa-carbidopa in supplementing occlusion therapy in older children with strabismic or anisometropic amblyopia. A clinical study was performed on 40 amblyopic children (19 strabismic and 21 anisometropic), 6 to 18 years old (mean age, 10.9 years). They received an average dose of 1.86 mg/kg/day (1.33-2.36 mg/kg/day) of levodopa and carbidopa (4:1 ratio) or a placebo in 3 divided doses over a 4-week period, combined with full-time occlusion. The occlusion was continued for the study duration of 3 months. Early Treatment Diabetic Retinopathy Study visual acuity charts and Cambridge low-contrast gratings for contrast sensitivity (CS) were used to assess visual functions. Tolerance and compliance with occlusion and capsule consumption were assessed. Visual acuity of the nonamblyopic eye did not deteriorate during the study in either group. CS decreased by 22 units in the levodopa group and increased in the placebo group by 53 units at the first month. The CS in the levodopa group recovered later by the third month of follow-up. Both the levodopa and the placebo groups showed significant improvement in visual function in the amblyopic eye (P <.001). Overall changes in logarithm of minimum angle of resolution values and CS in the amblyopic eyes were similar in both groups (P >.05). Strabismic and anisometropic amblyopes did not behave differently. Drug tolerance, occlusion compliance, and capsule ingestion compliance were similar between the groups, with no significant side effects. Clinically, levodopa supplementation does not offer any advantage over occlusion alone. Moreover, the risk of occlusion amblyopia could increase with the use of drugs like levodopa that might affect the plasticity of the visual cortex.

Hypothalamic digoxin, hemispheric chemical dominance, and mesenteric artery occlusion.

PubMed

Kurup, Ravi Kumar; Kurup, Paramesware Achutha

2003-12-01

The role of the isoprenoid pathway in vascular thrombosis, especially mesenteric artery occlusion and its relation to hemispheric dominance, was assessed in this study. The following parameters were measured in patients with mesenteric artery occlusion and individuals with right hemispheric, left hemispheric, and bihemispheric dominance: (1) plasma HMG CoA reductase, digoxin, dolichol, ubiquinone, and magnesium levels; (2) tryptophan/tyrosine catabolic patterns; (3) free radical metabolism; (4) glycoconjugate metabolism; and (5) membrane composition. In patients with mesenteric artery occlusion there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels, low ubiquinone, and elevated free radical levels. The RBC membrane Na(+)-K+ ATPase activity and serum magnesium were decreased. There was also an increase in tryptophan catabolites and reduction in tyrosine catabolites in the serum. There was an increase in cholesterol:phospholipid ratio and a reduction in glycoconjugate level of RBC membrane in these patients. The biochemical patterns obtained in mesenteric artery occlusion is similar to those obtained in left-handed/right hemispheric dominant individuals by the dichotic listening test. But all the patients with mesenteric artery occlusion were right-handed/left hemispheric dominant by the dichotic listening test. Hemispheric chemical dominance has no correlation with handedness or the dichotic listening test. Mesenteric artery occlusion occurs in right hemispheric chemically dominant individuals and is a reflection of altered brain function. Hemispheric chemical dominance may thus control the risk for developing vascular thrombosis in individuals.

Increased carboxyhemoglobin level during liver resection with inflow occlusion.

PubMed

Godai, Kohei; Hasegawa-Moriyama, Maiko; Kuniyoshi, Tamotsu; Matsunaga, Akira; Kanmura, Yuichi

2013-04-01

Controlling stress responses associated with ischemic changes due to bleeding and ischemia/reperfusion injury is essential for anesthetic management. Endogenous carboxyhemoglobin (COHb) is produced in the oxidative degradation of heme proteins by the stress-response enzyme heme oxygenase. Although the COHb level is elevated in critically ill patients, changes in endogenous COHb during anesthesia have not been well investigated. Therefore, we evaluated changes in endogenous COHb levels in patients undergoing liver resections with inflow occlusion. Levels of COHb were significantly increased after the Pringle maneuver. The inflow occlusion time in patients with increased COHb after the Pringle maneuver (∆COHb > 0.3 %) was significantly longer than in patients without increased COHb (∆COHb < 0.3 %) (P = 0.01). In addition, COHb changes were correlated with inflow occlusion time (P = 0.005, R(2) = 0.21). Neither total blood loss, transfusion volume of packed red blood cells, operation time, nor anesthetic time differed between patients with and without increased COHb. The results indicated that endogenous COHb levels were increased by inflow occlusion in patients undergoing liver resections, which suggests that changes in COHb may correlate with hepatic ischemia/reperfusion injury induced by inflow occlusion.

Occlusion and rupture of ex vivo capillary bifurcation due to acoustic droplet vaporization

NASA Astrophysics Data System (ADS)

Feng, Yi; Qin, Dui; Zhang, Jun; Zhang, Lei; Bouakaz, Ayache; Wan, Mingxi

2018-06-01

Gas embolotherapy (GE) consists in the occlusion of tumor blood vessels using gas emboli induced by acoustic droplet vaporization (ADV), to create tumor starvation and localized drug delivery. Therefore, the occlusion and rupture of capillary bifurcation due to ADV was investigated in an ex vivo rat mesentery model using a confocal acousto-optical high-speed microscope system. Following ADV bubble formation, coalescence, and translational movement, the growing bubbles lodged in and then occluded two different capillary bifurcations. Capillary rupture was induced at the bubble lodging area, immediately followed by gas extravasation and bubble dislodging. Before and after bubble lodgment/occlusion, a local microvessel invagination was observed due to the interactions between ADV bubbles and the microvessel itself, indicating a contribution to the capillary rupture. Understanding the transient dynamics of ADV bubble, the bubble-microvessel interaction and the consequent mechanical bio-effects in GE is of the paramount importance for developing and applying this approach in clinical practice.

Measurement of total occlusal convergence of 3 different tooth preparations in 4 different planes by dental students.

PubMed

Yoon, Stephan S; Cheong, Chan; Preisser, John; Jun, Sangho; Chang, Brian M; Wright, Robert F

2014-08-01

Total occlusal convergence of crown preparation is an important didactic and clinical concept in dental education. The purpose of this study was to compare the discrepancy between the total occlusal convergence of dental students' typodont crown preparations and the ideal range (4 to 10 degrees) in 3 different regions of the mouth and in 4 different planes of the teeth. The dental students of the Class of 2012 at Harvard School of Dental Medicine were asked to prepare typodont teeth for crowns on 3 different teeth, the maxillary left central incisor (ceramic), mandibular left first molar (complete metal), and mandibular left first premolar (metal ceramic), during their third year preclinical summative examination and the Comprehensive Clinical Examination in their fourth year. Eighteen students prepared 3 teeth in their third and fourth years, whereas 19 students participated only in their fourth year, for a total of 55 sets of 3 teeth. By using custom fit die bases to reproduce the position, a novel procedure of measuring each tooth was accomplished in 4 different planes: the faciolingual, mesiodistal, mesiofacial-distolingual, and mesiolingual-distofacial. The total occlusal convergence of each image was measured with a computer screen protractor. The gingival 2 mm of the axial wall was used to determine the taper of each wall. Linear mixed model analysis was used to estimate and compare the total occlusal convergences of different teeth and planes (α=.05). Bonferroni corrections were used to adjust for post hoc multiple comparisons. The mean total occlusal convergence varied by tooth and plane (2-way interaction; P<.001). For the first molar, dental students excessively tapered in all 4 planes; the model-predicted 99% CIs for the total occlusal convergence were as follows: faciolingual (12.7, 19.4), mesiodistal (14.0, 19.3), mesiofacial-distolingual (13,4, 19.4), and mesiolingual-distofacial (13.7, 19.1). For the central incisor, 99% CIs for the total occlusal

Complete occlusion after blunt injury to the abdominal aorta.

PubMed

Meghoo, Colin A L; Gonzalez, Ernest A; Tyroch, Alan H; Wohltmann, Christopher D

2003-10-01

Injury to the abdominal aorta after blunt trauma is uncommon. When this injury results in complete vessel occlusion, the presentation is dramatic. Timely intervention is essential. After a case report, we examined all reported cases of complete occlusion after blunt injury to the abdominal aorta and reviewed the cause, presentation, and management of this injury. Complete vessel occlusion arises from intimal injury. The most frequent mechanism is compression from a seat belt or steering wheel during a motor vehicle crash. Patients present with absent femoral and distal pulses in association with lower extremity neuropathy. Intervention commonly involves bypass grafting of the abdominal aorta. Complete occlusion after blunt trauma to the abdominal aorta is rare. Neurologic deficits most commonly arise from peripheral nerve ischemia. Reperfusion within 6 hours confers a greater chance of limb salvage and neurologic recovery.

Aphid watery saliva counteracts sieve-tube occlusion: a universal phenomenon?

PubMed

Will, Torsten; Kornemann, Sarah R; Furch, Alexandra C U; Tjallingii, W Fred; van Bel, Aart J E

2009-10-01

Ca2+-binding proteins in the watery saliva of Megoura viciae counteract Ca2+-dependent occlusion of sieve plates in Vicia faba and so prevent the shut-down of food supply in response to stylet penetration. The question arises whether this interaction between aphid saliva and sieve-element proteins is a universal phenomenon as inferred by the coincidence between sieve-tube occlusion and salivation. For this purpose, leaf tips were burnt in a number of plant species from four different families to induce remote sieve-plate occlusion. Resultant sieve-plate occlusion in these plant species was counteracted by an abrupt switch of aphid behaviour. Each of the seven aphid species tested interrupted its feeding behaviour and started secreting watery saliva. The protein composition of watery saliva appeared strikingly different between aphid species with less than 50% overlap. Secretion of watery saliva seems to be a universal means to suppress sieve-plate occlusion, although the protein composition of watery saliva seems to diverge between species.

Clinical outcomes in middle cerebral artery trunk occlusions versus secondary division occlusions after mechanical thrombectomy: pooled analysis of the Mechanical Embolus Removal in Cerebral Ischemia (MERCI) and Multi MERCI trials.

PubMed

Shi, Zhong-Song; Loh, Yince; Walker, Gary; Duckwiler, Gary R

2010-05-01

The benefit of endovascular revascularization of patients with acute ischemic stroke with middle cerebral artery (MCA) secondary division (M2) occlusions as compared with MCA trunk (M1) occlusions is not known. In this analysis, we compared revascularization status and clinical outcomes in patients with angiographically confirmed MCA M1 versus isolated M2 occlusions treated with mechanical thrombectomy using the Merci Retriever devices. We retrospectively analyzed the pooled data of patients with MCA strokes from the Mechanical Embolus Removal in Cerebral Ischemia (MERCI) and Multi MERCI trials. Patient data were dichotomized into 2 groups: MCA M1 occlusions and isolated M2 occlusions. Baseline characteristics, revascularization rates, hemorrhage rates, complications, outcomes, and mortality were evaluated for both groups. Of 178 patients with MCA occlusion treated in the MERCI and Multi MERCI trials, 84.3% had M1 lesions and 15.7% had isolated M2 lesions. Patients with isolated M2 occlusions were revascularized at a higher rate, required a lower mean number of passes, and were associated with a trend toward shorter mean procedure time than patients with M1 occlusions. No statistically significant differences were found between M2 and M1 groups for symptomatic hemorrhage, clinically significant procedural adverse events, favorable 90-day outcome, or 90-day mortality, although in all instances, the M2 outcomes were numerically better than those in M1 subjects. In multivariate analysis, final revascularization was the strongest independent predictor of good outcome at 90 days. Patients with both MCA M1 occlusions and isolated M2 occlusions can achieve a relatively high rate of revascularization and favorable clinical outcomes after mechanical thrombectomy. In fact, patients with isolated M2 occlusions had a higher rate of revascularization, required fewer passes, and had no increased complications compared with patients with M1 occlusions.

[Occlusion and posture: is there evidence of correlation?].

PubMed

Michelotti, A; Manzo, P; Farella, M; Martina, R

1999-11-01

The observation that the masticatory system and the postural body regulating system are anatomically and functionally related, has led to postulate several hypotheses of correlation between occlusal and postural disturbances. In the last decade, these arguments have gained a great social impact, also because they have been broadly spread by the mass-media. As a consequence, there has been a growing number of patients seeking concomitant occlusal and postural treatments. The aim of this study was to review critically the current evidence of correlation between the two systems; this in order to address clinical issues for the management of patients. Methodology of the studies reviewed has been evaluated according to the criteria suggested by Storey and Rugh 20 rif. Although there are some evidences of correlation between occlusion and posture, this appears limited to the cranio-cervical tract of the column and tends to disappear when descending in cranio-caudal direction. On the basis of this review of the literature, it's not advisable to treat postural imbalance by means of occlusal treatment or vice versa, particularly if the therapeutic modalities are irreversible.

Impact of the Occlusion Duration on the Performance of J-CTO Score in Predicting Failure of Percutaneous Coronary Intervention for Chronic Total Occlusion.

PubMed

de Castro-Filho, Antonio; Lamas, Edgar Stroppa; Meneguz-Moreno, Rafael A; Staico, Rodolfo; Siqueira, Dimytri; Costa, Ricardo A; Braga, Sergio N; Costa, J Ribamar; Chamié, Daniel; Abizaid, Alexandre

2017-06-01

The present study examined the association between Multicenter CTO Registry in Japan (J-CTO) score in predicting failure of percutaneous coronary intervention (PCI) correlating with the estimated duration of chronic total occlusion (CTO). The J-CTO score does not incorporate estimated duration of the occlusion. This was an observational retrospective study that involved all consecutive procedures performed at a single tertiary-care cardiology center between January 2009 and December 2014. A total of 174 patients, median age 59.5 years (interquartile range [IQR], 53-65 years), undergoing CTO-PCI were included. The median estimated occlusion duration was 7.5 months (IQR, 4.0-12.0 months). The lesions were classified as easy (score = 0), intermediate (score = 1), difficult (score = 2), and very difficult (score ≥3) in 51.1%, 33.9%, 9.2%, and 5.7% of the patients, respectively. Failure rate significantly increased with higher J-CTO score (7.9%, 20.3%, 50.0%, and 70.0% in groups with J-CTO scores of 0, 1, 2, and ≥3, respectively; P<.001). There was no significant difference in success rate according to estimated duration of occlusion (P=.63). Indeed, J-CTO score predicted failure of CTO-PCI independently of the estimated occlusion duration (P=.24). Areas under receiver-operating characteristic curves were computed and it was observed that for each occlusion time period, the discriminatory capacity of the J-CTO score in predicting CTO-PCI failure was good, with a C-statistic >0.70. The estimated duration of occlusion had no influence on the J-CTO score performance in predicting failure of PCI in CTO lesions. The probability of failure was mainly determined by grade of lesion complexity.

Accuracy of contacts calculated from 3D images of occlusal surfaces.

PubMed

DeLong, R; Knorr, S; Anderson, G C; Hodges, J; Pintado, M R

2007-06-01

Compare occlusal contacts calculated from 3D virtual models created from clinical records to contacts identified clinically using shimstock and transillumination. Upper and lower full arch alginate impressions and vinyl polysiloxane centric interocclusal records were made of 12 subjects. Stone casts made from the alginate impressions and the interocclusal records were optically scanned. Three-dimensional virtual models of the dental arches and interocclusal records were constructed using the Virtual Dental Patient Software. Contacts calculated from the virtual interocclusal records and from the aligned upper and lower virtual arch models were compared to those identified clinically using 0.01mm shimstock and transillumination of the interocclusal record. Virtual contacts and transillumination contacts were compared by anatomical region and by contacting tooth pairs to shimstock contacts. Because there is no accepted standard for identifying occlusal contacts, methods were compared in pairs with one labeled "standard" and the second labeled "test". Accuracy was defined as the number of contacts and non-contacts of the "test" that were in agreement with the "standard" divided by the total number of contacts and non-contacts of the "standard". Accuracy of occlusal contacts calculated from virtual interocclusal records and aligned virtual casts compared to transillumination were: 0.87+/-0.05 and 0.84+/-0.06 by region and 0.95+/-0.07 and 0.95+/-0.05 by tooth, respectively. Comparisons with shimstock were: 0.85+/-0.15 (record), 0.84+/-0.14 (casts), and 81+/-17 (transillumination). The virtual record, aligned virtual arches, and transillumination methods of identifying contacts are equivalent, and show better agreement with each other than with the shimstock method.

Intrarenal hemodynamic changes following acute partial renal arterial occlusion.

DOT National Transportation Integrated Search

1965-10-01

Both an increase and a decrease in total renal vascular resistance, following a period of total renal artery occlusion, have been reported from this laboratory. The duration of the occlusive period and height of the perfusion pressure were found to p...

Pulmonary veno-occlusive disease

MedlinePlus

... disorder. Alternative Names Pulmonary vaso-occlusive disease Images Respiratory system References Chin K, Channick RN. Pulmonary hypertension. In: Broaddus VC, Mason RJ, Ernst JD, et al, eds. Murray and Nadel's Textbook of Respiratory Medicine . 6th ed. Philadelphia, PA: Elsevier Saunders; 2016: ...

Continuous full-time occlusion of the sound eye vs full-time occlusion of the sound eye periodically alternating with occlusion of the amblyopic eye in treatment of amblyopia: a prospective randomized study.

PubMed

Stanković, B; Milenković, S

2007-01-01

To compare continuous full-time (24 hours per day) occlusion of the sound eye with full-time occlusion (24 hours per day) of the sound eye 1 day more than the years of age periodically alternating with occlusion of the amblyopic eye for 1 day, as treatments for profound strabismic amblyopia in children older than 5 years. A total of 53 patients with visual acuity (VA) of 0.4 and less in the amblyopic eye (tested by crowded Landolt Cs) after previously being provided optimal optical correction were randomly assigned to receive either of the two patching regimens. VA and pattern reversal visual evoked potentials (PVEP) were recorded prospectively at 1-month intervals. Improvement in VA and the reduction in crowding difficulties (CD) were the main outcome measures of the treatment efficiency. Both treatment modalities were equally effective. Of the 51 subjects who completed the study, 21 (41.2%) were cured whereas 32 (62.7%) attained satisfactory improvement. Recovery of VA was related to age, with cure being obtained in 23.5% (4/17) and satisfactory improvement in 52.9% (9/17) of patients older than 9 years. Larger gain in VA influenced the stability of the vision over time. It can be concluded that in clinically monitored parameters both treatment modalities were equally effective without any statistical or clinical significance in the observed groups of patients. However, events like the "trade-off" effect, occurrence of occlusion amblyopia, or prolongation of PVEP latency of the sound eye indicate that full-time continuous occlusion possibly presents a more effective form of treatment.

Evaluation of the Alteration of Occlusal Distribution in Unilateral Free-End and Intermediate Missing Cases.

PubMed

Kon, Kazuhiro; Shiota, Makoto; Sakuyama, Aoi; Ozeki, Maho; Kozuma, Wataru; Kawakami, Sawako; Kasugai, Shohei

2017-02-01

The present study aimed to evaluate the effect of implant prostheses on the occlusal force and area as well as the distribution of occlusal loading in unilateral free-end and intermediate missing cases. Fourteen healthy subjects (7 free-end missing cases in the first and second molars and 7 intermediate missing cases in the first molar region) were included. Six months after the implant prosthesis was placed, an occlusal evaluation was performed with or without the implant superstructure by using Dental Prescale film and an occluder device. In free-end missing cases, the total occlusal force and area, implant-side occlusal force and area, and implant-side occlusal force and area of the residual natural teeth were significantly affected by the implant prostheses. In intermediate missing cases, the implant-side occlusal force of the residual natural teeth was significantly affected by the implant prostheses. In free-end missing cases, the proportions of implant-side occlusal force, non-implant-side occlusal force, and implant-side occlusal force of the residual natural teeth relative to the total occlusal force were significantly affected by the implant prostheses. In the intermediate missing cases, the proportion of the implant-side occlusal force of the residual natural teeth relative to the total occlusal force was significantly affected by the implant prostheses. The proportion of the occlusal area was also significantly affected. In free-end missing cases, implant prostheses significantly increased the occlusal force and area, which resulted in the proper occlusal distribution. In intermediate missing cases, an implant prosthesis may only improve the same-side occlusal loading of the natural teeth.

Influence of Articulating Paper Thickness on Occlusal Contacts Registration: A Preliminary Report.

PubMed

Brizuela-Velasco, Aritza; Álvarez-Arenal, Ángel; Ellakuria-Echevarria, Joseba; del Río-Highsmith, Jaime; Santamaría-Arrieta, Gorka; Martín-Blanco, Nerea

2015-01-01

The objective of this preliminary study was to determine if the occlusal contact surface registered with an articulating paper during fixed prosthodontic treatment was contained within the area marked on a thicker articulating paper. This information would optimize any necessary occlusal adjustment of a prosthesis' veneering material. A convenience sample of 15 patients who were being treated with an implant-supported fixed singleunit dental prosthesis was selected. Occlusal registrations were obtained from each patient using 12-μm, 40-μm, 80-μm, and 200-μm articulating paper. Photographs of the occlusal registrations were obtained, and pixel measurements of the surfaces were taken and overlapped for comparison. The results showed that the thicker the articulating paper, the larger the occlusal contact area obtained. The differences were statistically significant. In all cases, the occlusal registrations obtained with the thinnest articulating paper were contained within the area marked on the thickest articulating paper. The results suggested that the use of thin articulating papers (12-μm or 40-μm) can avoid unnecessary grinding of veneering material or teeth during occlusal adjustment.

ACUTE RETINAL ARTERIAL OCCLUSIVE DISORDERS

PubMed Central

Hayreh, Sohan Singh

2011-01-01

The initial section deals with basic sciences; among the various topics briefly discussed are the anatomical features of ophthalmic, central retinal and cilioretinal arteries which may play a role in acute retinal arterial ischemic disorders. Crucial information required in the management of central retinal artery occlusion (CRAO) is the length of time the retina can survive following that. An experimental study shows that CRAO for 97 minutes produces no detectable permanent retinal damage but there is a progressive ischemic damage thereafter, and by 4 hours the retina has suffered irreversible damage. In the clinical section, I discuss at length various controversies on acute retinal arterial ischemic disorders. Classification of acute retinal arterial ischemic disorders These are of 4 types: CRAO, branch retinal artery occlusion (BRAO), cotton wools spots and amaurosis fugax. Both CRAO and BRAO further comprise multiple clinical entities. Contrary to the universal belief, pathogenetically, clinically and for management, CRAO is not one clinical entity but 4 distinct clinical entities – non-arteritic CRAO, non-arteritic CRAO with cilioretinal artery sparing, arteritic CRAO associated with giant cell arteritis (GCA) and transient non-arteritic CRAO. Similarly, BRAO comprises permanent BRAO, transient BRAO and cilioretinal artery occlusion (CLRAO), and the latter further consists of 3 distinct clinical entities - non-arteritic CLRAO alone, non-arteritic CLRAO associated with central retinal vein occlusion and arteritic CLRAO associated with GCA. Understanding these classifications is essential to comprehend fully various aspects of these disorders. Central retinal artery occlusion The pathogeneses, clinical features and management of the various types of CRAO are discussed in detail. Contrary to the prevalent belief, spontaneous improvement in both visual acuity and visual fields does occur, mainly during the first 7 days. The incidence of spontaneous visual

Design of a cost-effective, hemodynamically adjustable model for resuscitative endovascular balloon occlusion of the aorta (REBOA) simulation.

PubMed

Keller, Benjamin A; Salcedo, Edgardo S; Williams, Timothy K; Neff, Lucas P; Carden, Anthony J; Li, Yiran; Gotlib, Oren; Tran, Nam K; Galante, Joseph M

2016-09-01

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an adjunct technique for salvaging patients with noncompressible torso hemorrhage. Current REBOA training paradigms require large animals, virtual reality simulators, or human cadavers for acquisition of skills. These training strategies are expensive and resource intensive, which may prevent widespread dissemination of REBOA. We have developed a low-cost, near-physiologic, pulsatile REBOA simulator by connecting an anatomic vascular circuit constructed out of latex and polyvinyl chloride tubing to a commercially available pump. This pulsatile simulator is capable of generating cardiac outputs ranging from 1.7 to 6.8 L/min with corresponding arterial blood pressures of 54 to 226/14 to 121 mmHg. The simulator accommodates a 12 French introducer sheath and a CODA balloon catheter. Upon balloon inflation, the arterial waveform distal to the occlusion flattens, distal pulsation within the simulator is lost, and systolic blood pressures proximal to the balloon catheter increase by up to 62 mmHg. Further development and validation of this simulator will allow for refinement, reduction, and replacement of large animal models, costly virtual reality simulators, and perfused cadavers for training purposes. This will ultimately facilitate the low-cost, high-fidelity REBOA simulation needed for the widespread dissemination of this life-saving technique.

Determining Tooth Occlusal Surface Relief Indicator by Means of Automated 3d Shape Analysis

NASA Astrophysics Data System (ADS)

Gaboutchian, A. V.; Knyaz, V. A.

2017-05-01

Determining occlusal surface relief indicator plays an important role in odontometric tooth shape analysis. An analysis of the parameters of surface relief indicators provides valuable information about closure of dental arches (occlusion) and changes in structure of teeth in lifetime. Such data is relevant for dentistry or anthropology applications. Descriptive techniques commonly used for surface relief evaluation have limited precision which, as a result, does not provide for reliability of conclusions about structure and functioning of teeth. Parametric techniques developed for such applications need special facilities and are time-consuming which limits their spread and ease to access. Nevertheless the use of 3D models, obtained by photogrammetric techniques, allows attaining required measurements accuracy and has a potential for process automation. We introduce new approaches for determining tooth occlusal surface relief indicator and provide data on efficiency in use of different indicators in natural attrition evaluation.

Pressure monitoring predicts pulmonary vein occlusion in cryoballoon ablation.

PubMed

Sunaga, Akihiro; Masuda, Masaharu; Asai, Mitsutoshi; Iida, Osamu; Okamoto, Shin; Ishihara, Takayuki; Nanto, Kiyonori; Kanda, Takashi; Tsujimura, Takuya; Matsuda, Yasuhiro; Okuno, Syota; Mano, Toshiaki

2018-04-10

Pulmonary venography is routinely used to confirm pulmonary vein (PV) occlusion during cryoballoon ablation. However, this technique is significantly limited by the risks associated with contrast media, such as renal injury and contrast allergy. We hypothesized that PV occlusion can be predicted by elevation of the balloon catheter tip pressure, avoiding the need for contrast media. Forty-eight consecutive patients with paroxysmal atrial fibrillation who underwent PV isolation with the cryoballoon technique were enrolled. The balloon catheter tip pressure was measured in each PV before and after balloon inflation. We analyzed 200 applications of cryoballoon ablation in 185 PVs (excluding 3 common PVs and 1 extremely small right inferior PV) of 48 patients (age, 70 ± 11 years; male, n = 28; mean left atrial diameter, 38 ± 6 mm). Compared with patients with unsuccessful occlusion, patients with successful occlusion demonstrated a larger change in pressure after balloon inflation (6 ± 8 vs. 2 ± 4 mmHg, P < 0.001), a lower minimum temperature (- 49 ± 6 vs. - 40 ± 8 °C, P < 0.001), and a higher PV isolation rate (97 vs. 64%, P < 0.001). The best cutoff value of a change in pressure for predicting PV occlusion was 4.5 mmHg, with a sensitivity of 67%, specificity of 83%, and predictive accuracy of 72%. Pressure monitoring is helpful to confirm PV occlusion during cryoballoon ablation.

Parafunctional loading and occlusal device on stress distribution around implants: A 3D finite element analysis.

PubMed

Borges Radaelli, Manuel Tomás; Idogava, Henrique Takashi; Spazzin, Aloisio Oro; Noritomi, Pedro Yoshito; Boscato, Noéli

2018-04-30

An occlusal device is frequently recommended for patients with bruxism to protect implant-supported restorations and prevent marginal bone loss. Scientific evidence to support this treatment is lacking. The purpose of this 3-dimensional (3D) finite element study was to evaluate the influence of an acrylic resin occlusal device, implant length, and insertion depth on stress distribution with functional and parafunctional loadings. Computer-aided design software was used to construct 8 models. The models were composed of a mandibular bone section including the second premolar and first and second molars. Insertion depths (bone level and 2 mm subcrestal) were simulated at the first molar. Three natural antagonist maxillary teeth and the placement or not of an occlusal device were simulated. Functional (200-N axial and 10-N oblique) and parafunctional (1000-N axial and 25-N oblique) forces were applied. Finite element analysis (FEA) was used to determine the maximum principal stress for the cortical and trabecular bone and von Mises for implant and prosthetic abutment. Stress concentration was observed at the abutment-implant and the implant-bone interfaces. Occlusal device placement changed the pattern of stress distribution and reduced stress levels from parafunctional loading in all structures, except in the trabecular bone. Implants with subcrestal insertion depths had reduced stress at the implant-abutment interface and cortical bone around the implant abutment, while the stress increased in the bone in contact with the implant. Parafunctional loading increased the stress levels in all structures when compared with functional loading. An occlusal device resulted in the lowest stress levels at the abutment and implant and the most favorable stress distribution between the cortical and trabecular bone. Under parafunctional loading, an occlusal device was more effective in reducing stress distribution for longer implants inserted at bone level. Subcrestally, implant

Amplatzer vascular plug for rapid vessel occlusion in interventional neuroradiology

PubMed Central

Banfield, Jillian C

2016-01-01

The purpose of this paper is to report different uses of endovascular Amplatzer vascular plug (AVP) treatment for rapid vessel occlusion in the field of interventional neuroradiology. We retrospectively reviewed our interventional neuroradiology database from November 2010 to July 2015 and found nine patients who were treated with endovascular AVP. AVP was used for rapid vessel occlusion of common carotid artery (1 patient), internal carotid artery (5 patients), vertebral artery (2 patients), and internal jugular vein (1 patient). A median of three AVPs were used with almost immediate occlusion and no thromboembolic complications. Use of AVP is feasible, safe, rapid, and potentially cost-effective method for rapid occlusion of larger size vessels in the head and neck region for different indications. PMID:26515699

History of materials used for recording static and dynamic occlusal contact marks: a literature review

PubMed Central

Rahul, G R.; Poduval, Soorya T.; Shetty, Karunakar; Gupta, Bhawna; Rajora, Varun

2013-01-01

In the discipline of prosthetic dentistry it is important not only to examine the occlusion, but to be able to record, store, and transfer the information. Over the years many occlusion testing materials have been used. It has been suggested the clinical recording and transfer of information using waxes and other occlusion recording materials have disadvantages relating to inaccuracy and problems of manipulation. Therefore, there has been introduction of many new systems for recording occlusion contacts to overcome such problems. The correct physiological recovery of occlusion posses as much a challenge as ever for every dentist and technician. Even the smallest high spots measuring just a few microns can cause dysfunctions like temporo-mandibular pain. Occlusal proportions are being constantly changed with every procedure. Therefore, an understanding of the synergy of the teeth in static and dynamic occlusion forms the basis of good dentistry. The purpose of this review article is to give and overview of the various materials and methods that have been used to record occlusal contact marks. Key words:Occlusal contact marks, Occlusion indicators, Occlusion test materials, Occlusion recording materials. PMID:24455051