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Myron D Ginsberg - One of the best experts on this subject based on the ideXlab platform.

  • effect of delayed albumin hemodilution on infarction volume and brain edema after transient middle cerebral artery occlusion in rats
    Journal of Neurosurgery, 1997
    Co-Authors: Ludmila Belayev, Raul Busto, Weizhao Zhao, James A Clemens, Myron D Ginsberg
    Abstract:

    The authors examined the effect of delayed high-concentration albumin therapy on ischemic injury in a highly reproducible model of middle cerebral artery (MCA) occlusion in rats. Male Sprague-Dawley rats weighing 270 to 320 g were anesthetized with halothane and subjected to 120 minutes of temporary MCA occlusion induced by means of a poly-L-lysine-coated intraluminal Nylon Suture inserted retrograde via the external carotid artery into the internal carotid artery and MCA. The agent (20% human serum albumin [HSA]) or control solution (sodium chloride 0.9%) was administered intravenously at a dosage of 1% of body weight immediately after Suture removal following a 2-hour period of MCA occlusion. The animals' neurological status was evaluated during MCA occlusion (at 60 minutes) and daily for 3 days thereafter. The brains were perfusion-fixed, and infarct volumes and brain edema were determined. The HSA significantly improved the neurological score compared with saline at 24 hours after MCA occlusion. The rats treated with HSA also had significantly reduced total infarct volume (by 34%) and brain edema (by 81%) compared with saline-treated rats. There was a strong correlation between hematocrit level and brain edema (p < 0.01), and between total infarct volume or brain edema and neurological score at 24, 48, and 72 hours postinjury (p < 0.0002). These results strongly support the beneficial effect of delayed albumin therapy in transient focal ischemia and indicate its possible usefulness in treating patients with acute ischemic stroke.

  • quantitative evaluation of blood brain barrier permeability following middle cerebral artery occlusion in rats
    Brain Research, 1996
    Co-Authors: Ludmila Belayev, Raul Busto, Weizhao Zhao, Myron D Ginsberg
    Abstract:

    A sensitive quantitative fluorescence method was used to explore the time course and regional pattern of blood-brain barrier (BBB) opening after transient middle cerebral artery occlusion (MCAo). Male Sprague-Dawley rats were anesthetized with halothane and subjected to 2 h of temporary MCAo by retrograde insertion of an intraluminal Nylon Suture, coated with poly-L-lysine, through the external carotid artery into the internal carotid artery and MCA. Damage to the BBB was judged by extravasation of Evans Blue (EB) dye, which was administered either 2, 3, 24 or 48 h after onset of MCAo. Fluorometric quantitation of EB was performed 1 or 2 h later in six brain regions. Cerebral infarction volumes were quantitated from histopathological material at 72 h. EB extravasation first became grossly visible in the ipsilateral caudoputamen and neocortex following 3 h of MCAo, was grossly unapparent at 24-26 h, and was maximal at 48-50 h. Fluorescence quantitation confirmed that BBB opening was absent at 2-3 h but present at all later times. In the hemisphere ipsilateral to MCAo, a 179% mean increase in extravasation of EB (compared to sham rats) was measured at 4 h, 407% at 5 h, 311% at 26 h and 264% at 50 h. (in each case, P < 0.05 vs. sham). The volume of infarcted tissue at 72 h in this model was 163.6 +/- 7.7 mm3. Our results indicate that an initial, acute disruption of the BBB occurs between 3 and 5 h following MCAo, and that a later, more widespread increase in regional BBB permeability is present at 48 h. Regional measurement of Evans Blue extravasation offers a precise means of quantitating BBB disruption in focal cerebral ischemia; this method will be of considerable utility in assessing the BBB-protective properties of pharmacological agents.

Ludmila Belayev - One of the best experts on this subject based on the ideXlab platform.

  • lau 0901 a novel platelet activating factor receptor antagonist confers enduring neuroprotection in experimental focal cerebral ischemia in the rat
    Brain Research, 2009
    Co-Authors: Ludmila Belayev, Larissa Khoutorova, Kristal D Atkins, Alice Cherqui, Julio Alvarezbuilla, Nicolas G Bazan
    Abstract:

    LAU-0901, a novel platelet-activating factor (PAF) receptor antagonist, is highly neuroprotective in a rodent model of cerebral ischemia. This study was conducted to establish whether the neuroprotection induced by LAU-0901 persists with chronic survival. Male Sprague-Dawley rats were anesthetized with isoflurane and subjected to 2 h of temporary middle cerebral artery occlusion (MCAo) induced by means of a poly-L-lisine-coated intraluminal Nylon Suture. Animals were treated with either LAU-0901 (60 mg/kg) or vehicle (45% cyclodextran) administered i.p. at 2 h from onset of MCAo. They received neurobehavioral examinations during MCAo (60 min) and then at 1, 2, 3, 7, 14, 21 and 28 days followed by histopathology at 30 days. LAU-0901 significantly improved the behavior compared to the vehicle group, beginning on day 1 (by 29%, p=0.00007) and persisting throughout a 30-day survival period (42%, p=0.0001). Compared with vehicle treatment, LAU-0901 treatment significantly increased volume of non-infarcted brain tissue loss relative to the unlesioned hemisphere (16.3±4.6% vs. 46.0±10.3%, respectively). These results establish that LAU-0901 confers enduring ischemic neuroprotection.

  • effect of delayed albumin hemodilution on infarction volume and brain edema after transient middle cerebral artery occlusion in rats
    Journal of Neurosurgery, 1997
    Co-Authors: Ludmila Belayev, Raul Busto, Weizhao Zhao, James A Clemens, Myron D Ginsberg
    Abstract:

    The authors examined the effect of delayed high-concentration albumin therapy on ischemic injury in a highly reproducible model of middle cerebral artery (MCA) occlusion in rats. Male Sprague-Dawley rats weighing 270 to 320 g were anesthetized with halothane and subjected to 120 minutes of temporary MCA occlusion induced by means of a poly-L-lysine-coated intraluminal Nylon Suture inserted retrograde via the external carotid artery into the internal carotid artery and MCA. The agent (20% human serum albumin [HSA]) or control solution (sodium chloride 0.9%) was administered intravenously at a dosage of 1% of body weight immediately after Suture removal following a 2-hour period of MCA occlusion. The animals' neurological status was evaluated during MCA occlusion (at 60 minutes) and daily for 3 days thereafter. The brains were perfusion-fixed, and infarct volumes and brain edema were determined. The HSA significantly improved the neurological score compared with saline at 24 hours after MCA occlusion. The rats treated with HSA also had significantly reduced total infarct volume (by 34%) and brain edema (by 81%) compared with saline-treated rats. There was a strong correlation between hematocrit level and brain edema (p < 0.01), and between total infarct volume or brain edema and neurological score at 24, 48, and 72 hours postinjury (p < 0.0002). These results strongly support the beneficial effect of delayed albumin therapy in transient focal ischemia and indicate its possible usefulness in treating patients with acute ischemic stroke.

  • quantitative evaluation of blood brain barrier permeability following middle cerebral artery occlusion in rats
    Brain Research, 1996
    Co-Authors: Ludmila Belayev, Raul Busto, Weizhao Zhao, Myron D Ginsberg
    Abstract:

    A sensitive quantitative fluorescence method was used to explore the time course and regional pattern of blood-brain barrier (BBB) opening after transient middle cerebral artery occlusion (MCAo). Male Sprague-Dawley rats were anesthetized with halothane and subjected to 2 h of temporary MCAo by retrograde insertion of an intraluminal Nylon Suture, coated with poly-L-lysine, through the external carotid artery into the internal carotid artery and MCA. Damage to the BBB was judged by extravasation of Evans Blue (EB) dye, which was administered either 2, 3, 24 or 48 h after onset of MCAo. Fluorometric quantitation of EB was performed 1 or 2 h later in six brain regions. Cerebral infarction volumes were quantitated from histopathological material at 72 h. EB extravasation first became grossly visible in the ipsilateral caudoputamen and neocortex following 3 h of MCAo, was grossly unapparent at 24-26 h, and was maximal at 48-50 h. Fluorescence quantitation confirmed that BBB opening was absent at 2-3 h but present at all later times. In the hemisphere ipsilateral to MCAo, a 179% mean increase in extravasation of EB (compared to sham rats) was measured at 4 h, 407% at 5 h, 311% at 26 h and 264% at 50 h. (in each case, P < 0.05 vs. sham). The volume of infarcted tissue at 72 h in this model was 163.6 +/- 7.7 mm3. Our results indicate that an initial, acute disruption of the BBB occurs between 3 and 5 h following MCAo, and that a later, more widespread increase in regional BBB permeability is present at 48 h. Regional measurement of Evans Blue extravasation offers a precise means of quantitating BBB disruption in focal cerebral ischemia; this method will be of considerable utility in assessing the BBB-protective properties of pharmacological agents.

F Grehn - One of the best experts on this subject based on the ideXlab platform.

  • improved Suture for fornix based conjunctival flap in filtering surgery
    International Ophthalmology, 1992
    Co-Authors: N Pfeiffer, F Grehn
    Abstract:

    Major problems in the early postoperative phase in filtering surgery are hypotony, flattening of the anterior chamber and choroidal detachment. We describe a new Suture technique for the closure of the conjunctiva in goniotrephination with a fornix-based conjunctival flap which is helpful in reducing these complications. After dissecting the conjunctiva from the limbus, a shallow groove is cut directly behind the former conjunctival insertion. At the end of the operation the conjunctiva is Sutured into this groove using a running 10.0 Nylon Suture in a meander-like fashion. A very tight wound closure results. We used this technique in 104 consecutive goniotrephinations. We found a low incidence of only mild external fistulation, hypotony, flattening of the anterior chamber and choroidal detachment. Astigmatism induced by the operation was-1.2+±1.2D, usually with the rule.

John H Zhang - One of the best experts on this subject based on the ideXlab platform.

  • comparison of silicon coated Nylon Suture to plain Nylon Suture in the rat middle cerebral artery occlusion model
    Journal of Neuroscience Methods, 2006
    Co-Authors: Norihito Shimamura, Gerald A Matchett, Tamiji Tsubokawa, Hiroki Ohkuma, John H Zhang
    Abstract:

    A variety of intraluminal Sutures have been used in the middle cerebral artery occlusion model (MCAO) of focal ischemia. In the present study we tested commercially available silicon-coated Nylon Suture in the MCAO model and compared the results to traditional monofilament Nylon Suture occlusion. Twelve Sprague-Dawley male rats were randomly divided two groups, MCAO with 4-0 Nylon Suture (Group N, n = 6) and MCAO with silicone-coated 4-0 Nylon Suture (Group S, n = 6). Rats were sacrificed 24 h after reperfusion. Assessment included mortality rates, neurological evaluation, and infarct volume. One rat died in each group from subarachanoid hemorrhage. Neurological evaluation demonstrated that Group S tended to have worse neurological outcomes than Group N, although this difference was not statistically significant. On TTC stain Group S had significantly larger infarct volumes than Group N. We conclude that the commercially available silicone-coated occlusion Suture provides better occlusion of the middle cerebral artery than the traditional uncoated Nylon Suture. Classification: Disease-related neuroscience (Section 6).

Choul Yong Park - One of the best experts on this subject based on the ideXlab platform.

  • Low recurrence rate of anchored conjunctival rotation flap technique in pterygium surgery.
    BMC Ophthalmology, 2017
    Co-Authors: Dong Ju Kim, Roy S Chuck, Jimmy K. Lee, Choul Yong Park
    Abstract:

    To report the recurrence rate for an anchored conjunctival rotation flap technique in primary pterygium surgery. Primary pterygium surgeries performed using anchored conjunctival rotation flap techniques (110 eyes in 110 patients) with a minimum follow-up of 12 months were reviewed. In this technique, a conjunctival flap is rotated to cover the bare sclera and Suture-fixated with either 8–0 polyglactin (41 eyes) or 10–0 Nylon (69 eyes). The recurrence rate was determined, and the two Suture materials utilized were compared. The recurrence rate was 2.71% (3 cases in 110 eyes) when an anchored conjunctival rotation flap technique was used and patients were monitored for 26.40 ± 17.09 months. Interestingly, the recurrences were only observed in polyglactin-Sutured eyes. No recurrence was detected in Nylon-Sutured eyes. No other complications were observed in either group. The anchored conjunctival rotation flap technique for pterygium surgery has a relatively low recurrence rate. Nylon Suture-fixation of the flap was found to be superior to polyglactin Suture-fixation in preventing recurrence.

  • Low recurrence rate of anchored conjunctival rotation flap technique in pterygium surgery
    BMC, 2017
    Co-Authors: Dong Ju Kim, Roy S Chuck, Jimmy K. Lee, Choul Yong Park
    Abstract:

    Abstract Background To report the recurrence rate for an anchored conjunctival rotation flap technique in primary pterygium surgery. Methods Primary pterygium surgeries performed using anchored conjunctival rotation flap techniques (110 eyes in 110 patients) with a minimum follow-up of 12 months were reviewed. In this technique, a conjunctival flap is rotated to cover the bare sclera and Suture-fixated with either 8–0 polyglactin (41 eyes) or 10–0 Nylon (69 eyes). The recurrence rate was determined, and the two Suture materials utilized were compared. Results The recurrence rate was 2.71% (3 cases in 110 eyes) when an anchored conjunctival rotation flap technique was used and patients were monitored for 26.40 ± 17.09 months. Interestingly, the recurrences were only observed in polyglactin-Sutured eyes. No recurrence was detected in Nylon-Sutured eyes. No other complications were observed in either group. Conclusions The anchored conjunctival rotation flap technique for pterygium surgery has a relatively low recurrence rate. Nylon Suture-fixation of the flap was found to be superior to polyglactin Suture-fixation in preventing recurrence