Science.gov

Sample records for acute retinal ischemia

  1. Assessment of ischemia in acute central retinal vein occlusion from inner retinal reflectivity on spectral domain optical coherence tomography

    PubMed Central

    Browning, David J; Punjabi, Omar S; Lee, Chong

    2017-01-01

    Purpose To determine the relationship between different spectral domain optical coherence tomography (SD-OCT) signs of retinal ischemia in acute central retinal vein occlusion (CRVO) and whether they predict anterior segment neovascularization (ASNV). Design Retrospective, observational study. Subjects Thirty-nine consecutive patients with acute CRVO and 12 months of follow-up. Methods We graded baseline SD-OCTs for increased reflectivity of the inner retina, loss of definition of inner retinal layers, presence of a prominent middle-limiting membrane (p-MLM) sign, and presence of paracentral acute middle maculopathy (PAMM). Graders were masked with respect to all clinical information. Results The intraclass correlation coefficients (ICCs) of grading–regrading by graders 1 and 2 were 0.8104, 95% confidence interval (CI) (0.6686, 0.8956), and 0.7986, 95% CI (0.6475, 0.8892), respectively. The intragrader coefficients of repeatability (COR) for graders 1 and 2 were 0.94 and 0.92, respectively. The ICC of graders 1 compared with 2 was 0.8039, 95% CI (0.6544, 0.8916). The intergrader COR was 0.80. SD-OCT grades of baseline ischemia were not associated with baseline visual acuity (VA), central subfield mean thickness (CSMT), or relative afferent pupillary defect; 12-month VA, CSMT, change in VA, change in CSMT, number of antivascular endothelial growth factor injections or corticosteroid injections, or proportion of eyes developing ASNV. SD-OCT grades of ischemia did not correlate with the proportion of eyes having the p-MLM sign or PAMM. PAMM and p-MLM are milder signs of ischemia than increased reflectivity of the inner retinal layers. Eyes with PAMM can evolve, losing PAMM and gaining the p-MLM sign. Conclusion Grading of ischemia from SD-OCT in acute CRVO was repeatable within graders and reproducible across graders for the graders in this study. SD-OCT signs of ischemia are not correlated with each other and do not reliably predict subsequent ASNV. Close

  2. Acute Retinal Ischemia Inhibits Endothelium-Dependent Nitric Oxide–Mediated Dilation of Retinal Arterioles via Enhanced Superoxide Production

    PubMed Central

    Ren, Yi; Potts, Luke B.; Yuan, Zhaoxu; Kuo, Enoch; Rosa, Robert H.; Kuo, Lih

    2012-01-01

    Purpose. Because retinal vascular disease is associated with ischemia and increased oxidative stress, the vasodilator function of retinal arterioles was examined after retinal ischemia induced by elevated intraocular pressure (IOP). The role of superoxide anions in the development of vascular dysfunction was assessed. Methods. IOP was increased and maintained at 80 to 90 mm Hg for 30, 60, or 90 minutes by infusing saline into the anterior chamber of a porcine eye. The fellow eye with normal IOP (10–20 mm Hg) served as control. In some pigs, superoxide dismutase mimetic TEMPOL (1 mM) or vehicle (saline) was injected intravitreally before IOP elevation. After enucleation, retinal arterioles were isolated and pressurized without flow for functional analysis by recording diameter changes using videomicroscopic techniques. Dihydroethidium (DHE) was used to detect superoxide production in isolated retinal arterioles. Results. Isolated retinal arterioles developed stable basal tone and the vasodilations to endothelium-dependent nitric oxide (NO)-mediated agonists bradykinin and L-lactate were significantly reduced only by 90 minutes of ischemia. However, vasodilation to endothelium-independent NO donor sodium nitroprusside was unaffected after all time periods of ischemia. DHE staining showed that 90 minutes of ischemia significantly increased superoxide levels in retinal arterioles. Intravitreal injection of membrane-permeable radical scavenger but not vehicle before ischemia prevented elevation of vascular superoxide and preserved bradykinin-induced dilation. Conclusions. Endothelium-dependent NO-mediated dilation of retinal arterioles is impaired by 90 minutes of ischemia induced by elevated IOP. The inhibitory effect appears to be mediated by the alteration of NO signaling via vascular superoxide. PMID:22110081

  3. Intracellular Signalling in Retinal Ischemia

    DTIC Science & Technology

    1990-07-01

    36) However, vascularization of the RPE is not known to occur in human diseases of photoreceptor degeneration, such as retinitis pigmentosa ...A.C. (1986) Retinitis pigmentosa and retinal neovascularization. Ophthalmology 91, 1599- 1603. Figure la: Control rat retina, 8 weeks of age, central...TITLE (Include Security Classification) Intracellular Signalling in Retinal Ischemia 12. PERSONAL AUTHOR(S) Burns, Margaret Sue; Bellhorn, Roy William

  4. [Retinal ischemia and nitric oxide].

    PubMed

    Neroev, V V; Arkhipova, M M

    2003-01-01

    Retinal ischemia is the main chain in the pathogenesis of vascular diseases of the eye. It was established that nitric oxide (NO) plays the key role in the development of ischemia. Recent understanding of the NO role, as a universal regulator of the cellular and tissue metabolism, is presented. The authors' and published data were used to design a scheme of pathogenesis of retinal ischemia with regard for the NO role. NO can produce both positive and negative effects depending on a stage of the process, NO concentration and on a number of other factors if they are present. Initial stages of hypoxia/ischemia are accompanied by an activation of all forms of NO-synthases (NOS) caused by the influence of biologically active substances (cytokines, prostaglandins, serotonin, bradykinin, glycolisis suboxide products etc.). The activation of inducible NOS, which synthesize a bigger quantity of NO possessing a direct cytotoxic action and contributing to the production of highly toxic radical of peroxinitrit, is in the focus of attention. The damage of cellular structures due to free-radical processes leads to the development of endothelial, macrophage and thrombocyte malfunctions, which manifest itself through a reduced activity of endothelial NOS and through disruption of NO-dependent processes (vasospasm, an increased aggregation of platelets and a reduced fibrinolytic activity). A sharp reduction of NO synthesis substrate (L-arginine) is observed in patients with retinal ischemia. The aggravation of ischemia causes a decrease of NO synthesis due to an exhaustion of L-arginine and its intensified consumption in the course of free-radical processes. The use of NO-inhibitors and of NO-donors at different stages of retinal ischemia prevents the development of neovascularization and proliferation.

  5. Vitreal Oxygenation in Retinal Ischemia Reperfusion

    PubMed Central

    Abdallah, Walid; Ameri, Hossein; Barron, Ernesto; Chader, Gerald J.; Greenbaum, Elias; Hinton, David R.

    2011-01-01

    Purpose. To study the feasibility of anterior vitreal oxygenation for the treatment of acute retinal ischemia. Methods. Twenty rabbits were randomized into an oxygenation group, a sham treatment group, and a no treatment group. Baseline electroretinography (ERG) and preretinal oxygen (Po2) measurements were obtained 3 to 5 days before surgery. Intraocular pressure was raised to 100 mm Hg for 90 minutes and then normalized. The oxygenation group underwent vitreal oxygenation for 30 minutes using intravitreal electrodes. The sham treatment group received inactive electrodes for 30 minutes while there was no intervention for the no treatment group. Preretinal Po2 in the posterior vitreous was measured 30 minutes after intervention or 30 minutes after reperfusion (no treatment group) and on postoperative days (d) 3, 6, 9, and 12. On d14, rabbits underwent ERG and were euthanatized. Results. Mean final (d12) Po2 was 10.64 ± 0.77 mm Hg for the oxygenation group, 2.14 ± 0.61 mm Hg for the sham group, and 1.98 ± 0.63 mm Hg for the no treatment group. On ERG, scotopic b-wave amplitude was significantly preserved in the oxygenation group compared with the other two groups. Superoxide dismutase assay showed higher activity in the operated eyes than in the nonoperated control eyes in the sham treatment group and no treatment group only. Histopathology showed preservation of retinal architecture and choroidal vasculature in the oxygenation group, whereas the sham-treated and nontreated groups showed retinal thinning and choroidal atrophy. Conclusions. In severe total ocular ischemia, anterior vitreal oxygenation supplies enough oxygen to penetrate the retinal thickness, resulting in rescue of the RPE/choriocapillaris that continues to perfuse, hence sparing the retinal tissue from damage. PMID:21051734

  6. Vitreal Ocygenation in Retinal Ischemia Reperfusion

    SciTech Connect

    Abdallab, Walid; AmeriMD, Hossein; Barron, Ernesto; ChaderPhD, Gerald; Greenbaum, Elias; Hinton, David E; Humayun, Mark S

    2011-01-01

    PURPOSE. To study the feasibility of anterior vitreal oxygenation for the treatment of acute retinal ischemia. METHODS. Twenty rabbits were randomized into an oxygenation group, a sham treatment group, and a no treatment group. Baseline electroretinography (ERG) and preretinal oxygen (PO2) measurements were obtained 3 to 5 days before surgery. Intraocular pressure was raised to 100 mm Hg for 90 minutes and then normalized. The oxygenation group underwent vitreal oxygenation for 30 minutes using intravitreal electrodes. The sham treatment group received inactive electrodes for 30 minutes while there was no intervention for the no treatment group. Preretinal PO2 in the posterior vitreous was measured 30 minutes after intervention or 30 minutes after reperfusion (no treatment group) and on postoperative days (d) 3, 6, 9, and 12. On d14, rabbits underwent ERG and were euthanatized.

  7. Therapy for acute retinal necrosis.

    PubMed

    Kawaguchi, Tatsushi; Spencer, Doran B; Mochizuki, Manabu

    2008-01-01

    Acute retinal necrosis is a progressive necrotizing retinopathy caused by herpes simplex virus (HSV) or varicella zoster virus (VZV). The mainstay of its treatment is antiviral therapy against these pathogenic organisms, such as intravenous acyclovir or oral valacyclovir. Systemic and topical corticosteroids together with antiviral therapy are used as an anti-inflammatory treatment to minimize damages to the optic nerve and retinal blood vessels. Because the majority of severe cases of the disease show occlusive retinal vasculitis, a low dosage of aspirin is used as anti-thrombotic treatment. Vitreo-retinal surgery is useful to repair rhegmatogenous retinal detachment, one of the main late-stage complications. Moreover, recent articles have reported some encouraging results of prophylactic vitrectomy before rhegmatogenous retinal detachment occurs. The efficacy of laser photocoagulation to prevent the development or extension of rhegmatogenous retinal detachment is controversial. Despite these treatments, the visual prognosis of acute retinal necrosis is still poor, in particular VZV-induced acute retinal necrosis.

  8. Ischemia

    NASA Astrophysics Data System (ADS)

    Byeon, Suk Ho; Kim, Min; Kwon, Oh Woong

    "Ischemia" implies a tissue damage derived from perfusion insufficiency, not just an inadequate blood supply. Mild thickening and increased reflectivity of inner retina and prominent inner part of synaptic portion of outer plexiform layer are "acute retinal ischemic changes" visible on OCT. Over time, retina becomes thinner, especially in the inner portion. Choroidal perfusion supplies the outer portion of retina; thus, choroidal ischemia causes predominant change in the corresponding tissue.

  9. Ocular Sarcoidosis Limited to Retinal Vascular Ischemia and Neovascularization

    PubMed Central

    Dyer, Gawain; Shaikh, Saad

    2016-01-01

    A 59-year-old Caucasian male experienced progressive vision loss secondary to retinal vascular ischemia and neovascularization. At no time did he present with uveitis or vasculitis, and his serology tests were all negative. He was soon after diagnosed with sarcoidosis by hilar lymph node lung biopsy. Our patient demonstrates an atypical presentation of ocular sarcoidosis, manifesting solely as neovascularization and retinal vascular ischemia. Ophthalmologists should consider proliferative sarcoid retinopathy in patients with neovascularization. PMID:27928517

  10. 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

  11. Vasospastic Limb Ischemia Presenting Acute and Chronic Limb Ischemia

    PubMed Central

    2014-01-01

    Vasospastic limb ischemia might have been underappreciated compared to vasospasm in other territories such as heart and brain. However, an increasing awareness of this vascular disorder can be translated to an improved patients’ care. Herein, we report a case of vasospasm presenting acute and chronic limb ischemia in four extremities. PMID:24995065

  12. Acute mesenteric ischemia in young adults.

    PubMed

    Ozturk, Gurkan; Aydinli, Bulent; Atamanalp, S Selcuk; Yildirgan, M Ilhan; Ozoğul, Bünyami; Kısaoğlu, Abdullah

    2012-08-01

    Acute mesenteric ischemia is commonly seen in old patients. This study was undertaken to show that mesenteric ischemia might be seen in individuals under 40 years of age and that its diagnosis is challenging. Twenty-six patients with acute mesenteric ischemia under the age of 40 were studied. The main symptom on admission was abdominal pain. Symptom duration varied between 12 h and 5 days. The medical history of the patients revealed that 9 had no previous diseases. Other 17 had predisposing factors in the first evaluation. None of the patients had any history of narcotic or drug abuse. Ten patients presented with signs and symptoms of sepsis and septic shock. Preoperative diagnosis was acute intestinal ischemia only in 6 patients. Preoperatively, all the patients had intestinal or colonic ischemia and necrosis; one had additional ischemia of the liver, stomach, duodenum, and pancreas. Six patients had massive intestinal necrosis. The overall postoperative complication and overall mortality rates were 61.5 and 26.9 %, respectively. Complications and mortality were determined to be associated with previous pulmonary disease, acidosis, presence of septic shock, acute renal failure, extent of the ischemia and extent of resection, second look operations, previous cardiac events, and the kind of affected bowel (colon involvement).

  13. Acute small bowel ischemia: CT imaging findings.

    PubMed

    Segatto, Enrica; Mortelé, Koenraad J; Ji, Hoon; Wiesner, Walter; Ros, Pablo R

    2003-10-01

    Small bowel ischemia is a disorder related to a variety of conditions resulting in interruption or reduction of the blood supply of the small intestine. It may present with various clinical and radiologic manifestations, and ranges pathologically from localized transient ischemia to catastrophic necrosis of the intestinal tract. The primary causes of insufficient blood flow to the small intestine are various and include thromboembolism (50% of cases), nonocclusive causes, bowel obstruction, neoplasms, vasculitis, abdominal inflammatory conditions, trauma, chemotherapy, radiation, and corrosive injury. Computed tomography (CT) can demonstrate changes because of ischemic bowel accurately, may be helpful in determining the primary cause of ischemia, and can demonstrate important coexistent findings or complications. However, common CT findings in acute small bowel ischemia are not specific and, therefore, it is often a combination of clinical, laboratory and radiologic signs that may lead to a correct diagnosis. Understanding the pathogenesis of various conditions leading to mesenteric ischemia and being familiar with the spectrum of diagnostic CT signs may help the radiologist recognize ischemic small bowel disease and avoid delayed diagnosis. The aim of this article is to provide a review of the pathogenesis and various causes of acute small bowel ischemia and to demonstrate the contribution of CT in the diagnosis of this complex disease.

  14. Acute limb ischemia due to ergotism.

    PubMed

    Naz, Iram; Sophie, Ziad

    2006-08-01

    Acute ischemia of an extremity potentially threatens limb loss and occasionally the life of the patient. We are reporting two cases of extremity ischemia secondary to ergot poisoning. The first patient was a 60 years old woman, who presented with a 15 days history of ischemia of the left arm with gangrene of the fingers and pain in the resting right hand for one day. Right brachial artery catheterization showed severe spasm of the artery which was resolved by passage of the inflated balloon catheter. She underwent amputation for gangrene of the left hand. The second patient presented with bilateral symmetrical ischemia of the lower extremities which improved upon withdrawal of the ergot containing medicine. She responded to nifedipine.

  15. Effect of retinal ischemia on the non-image forming visual system.

    PubMed

    González Fleitas, María Florencia; Bordone, Melina; Rosenstein, Ruth E; Dorfman, Damián

    2015-03-01

    Retinal ischemic injury is an important cause of visual impairment. The loss of retinal ganglion cells (RGCs) is a key sign of retinal ischemic damage. A subset of RGCs expressing the photopigment melanopsin (mRGCs) regulates non-image-forming visual functions such as the pupillary light reflex (PLR), and circadian rhythms. We studied the effect of retinal ischemia on mRGCs and the non-image-forming visual system function. For this purpose, transient ischemia was induced by raising intraocular pressure to 120 mm Hg for 40 min followed by retinal reperfusion by restoring normal pressure. At 4 weeks post-treatment, animals were subjected to electroretinography and histological analysis. Ischemia induced a significant retinal dysfunction and histological alterations. At this time point, a significant decrease in the number of Brn3a(+) RGCs and in the anterograde transport from the retina to the superior colliculus and lateral geniculate nucleus was observed, whereas no differences in the number of mRGCs, melanopsin levels, and retinal projections to the suprachiasmatic nuclei and the olivary pretectal nucleus were detected. At low light intensity, a decrease in pupil constriction was observed in intact eyes contralateral to ischemic eyes, whereas at high light intensity, retinal ischemia did not affect the consensual PLR. Animals with ischemia in both eyes showed a conserved locomotor activity rhythm and a photoentrainment rate which did not differ from control animals. These results suggest that the non-image forming visual system was protected against retinal ischemic damage.

  16. Acute mesenteric ischemia: current multidisciplinary approach.

    PubMed

    Savlania, Ajay; Tripathi, Ramesh K

    2017-04-01

    The aim of this review was to describe and discuss the mechanisms of acute mesenteric ischemia (AMI) and the rationale and conduct of currently available endovascular and open surgical techniques in its management. We also propose an algorithm to support the current multidisciplinary approach in decision-making for mesenteric revascularization to manage this high-risk entity.

  17. Retinal fractals and acute lacunar stroke.

    PubMed

    Cheung, Ning; Liew, Gerald; Lindley, Richard I; Liu, Erica Y; Wang, Jie Jin; Hand, Peter; Baker, Michelle; Mitchell, Paul; Wong, Tien Y

    2010-07-01

    This study aimed to determine whether retinal fractal dimension, a quantitative measure of microvascular branching complexity and density, is associated with lacunar stroke. A total of 392 patients presenting with acute ischemic stroke had retinal fractal dimension measured from digital photographs, and lacunar infarct ascertained from brain imaging. After adjusting for age, gender, and vascular risk factors, higher retinal fractal dimension (highest vs lowest quartile and per standard deviation increase) was independently and positively associated with lacunar stroke (odds ratio [OR], 4.27; 95% confidence interval [CI], 1.49-12.17 and OR, 1.85; 95% CI, 1.20-2.84, respectively). Increased retinal microvascular complexity and density is associated with lacunar stroke.

  18. Endovascular management of acute limb ischemia.

    PubMed

    Peeters, P; Verbist, J; Keirse, K; Deloose, K; Bosiers, M

    2010-06-01

    Acute limb ischemia (ALI) refers to a rapid worsening of limb perfusion resulting in rest pain, ischemic ulcers or gangrene. With an estimated incidence of 140 million/year, ALI is serious limb-threatening and life-threatening medical emergency demanding prompt action. Three prospective, randomized clinical trials provide data on trombolytic therapy versus surgical intervention in patients with acute lower extremity ischemia. Although they did not give us the final answer, satisfactory results are reported for percutaneous thrombolysis compared with surgery. Moreover, they suggest an important advantage of thrombolysis in acute bypass graft occlusions. Therefore, we believe thrombolytic therapy should be a part of the vascular surgeon's armamentarium to safely and successfully treat ALI patients.

  19. Changes in Retinal Morphology, Electroretinogram and Visual Behavior after Transient Global Ischemia in Adult Rats

    PubMed Central

    Zhao, Ying; Yu, Bo; Xiang, Yong-Hui; Han, Xin-Jia; Xu, Ying; So, Kwok-Fai; Xu, An-Ding; Ruan, Yi-Wen

    2013-01-01

    The retina is a light-sensitive tissue of the central nervous system that is vulnerable to ischemia. The pathological mechanism underlying retinal ischemic injury is not fully understood. The purpose of this study was to investigate structural and functional changes of different types of rat retinal neurons and visual behavior following transient global ischemia. Retinal ischemia was induced using a 4-vessel occlusion model. Compared with the normal group, the number of βIII-tubulin positive retinal ganglion cells and calretinin positive amacrine cells were reduced from 6 h to 48 h following ischemia. The number of recoverin positive cone bipolar cells transiently decreased at 6 h and 12 h after ischemia. However, the fluorescence intensity of rhodopsin positive rod cells and fluorescent peanut agglutinin positive cone cells did not change after reperfusion. An electroretinogram recording showed that the a-wave, b-wave, oscillatory potentials and the photopic negative response were completely lost during ischemia. The amplitudes of the a- and b-waves were partially recovered at 1 h after ischemia, and returned to the control level at 48 h after reperfusion. However, the amplitudes of oscillatory potentials and the photopic negative response were still reduced at 48 h following reperfusion. Visual behavior detection showed there was no significant change in the time spent in the dark chamber between the control and 48 h group, but the distance moved, mean velocity in the black and white chambers and intercompartmental crosses were reduced at 48 h after ischemia. These results indicate that transient global ischemia induces dysfunction of retinal ganglion cells and amacrine cells at molecular and ERG levels. However, transient global ischemia in a 17 minute duration does not appear to affect photoreceptors. PMID:23776500

  20. Peripheral retinal ischemia in a young Indian woman with neurofibromatosis type 1☆☆☆

    PubMed Central

    Seth, Anisha; Ghosh, Basudeb; Gupta, Anika; Goel, Neha

    2015-01-01

    Neurofibromatosis type 1 (NF-1) is an autosomal dominantly inherited disease characterized by café-au-lait spots, neurofibromas, axillary freckling, Lisch nodules of iris, gliomas and various systemic vascular ischemic manifestations mainly in the aorta, brain and kidney. Retinal vascular manifestations in patients with NF-1 are usually representative of retinal capillary hemangiomatosis. Few cases of NF-1 with retinal vascular occlusive disease have been described. We describe a young Indian woman with NF-1 with unilateral peripheral retinal ischemia but no vascular abnormality at the posterior pole. PMID:26949362

  1. Hypoxic-Preconditioned Bone Marrow Stem Cell Medium Significantly Improves Outcome After Retinal Ischemia in Rats

    PubMed Central

    Roth, Steven; Dreixler, John C.; Mathew, Biji; Balyasnikova, Irina; Mann, Jacob R.; Boddapati, Venkat; Xue, Lai; Lesniak, Maciej S.

    2016-01-01

    Purpose We have previously demonstrated the protective effect of bone marrow stem cell (BMSC)-conditioned medium in retinal ischemic injury. We hypothesized here that hypoxic preconditioning of stem cells significantly enhances the neuroprotective effect of the conditioned medium and thereby augments the protective effect in ischemic retina. Methods Rats were subjected to retinal ischemia by increasing intraocular pressure to 130 to 135 mm Hg for 55 minutes. Hypoxic-preconditioned, hypoxic unconditioned, or normoxic medium was injected into the vitreous 24 hours after ischemia ended. Recovery was assessed 7 days after injections by comparing electroretinography measurements, histologic examination, and apoptosis (TUNEL, terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling assay). To compare proteins secreted into the medium in the groups and the effect of hypoxic exposure, we used rat cytokine arrays. Results Eyes injected with hypoxic BMSC–conditioned medium 24 hours after ischemia demonstrated significantly enhanced return of retinal function, decreased retinal ganglion cell layer loss, and attenuated apoptosis compared to those administered normoxic or hypoxic unconditioned medium. Hypoxic-preconditioned medium had 21 significantly increased protein levels compared to normoxic medium. Conclusions The medium from hypoxic-preconditioned BMSCs robustly restored retinal function and prevented cell loss after ischemia when injected 24 hours after ischemia. The protective effect was even more pronounced than in our previous studies of normoxic conditioned medium. Prosurvival signals triggered by the secretome may play a role in this neuroprotective effect. PMID:27367588

  2. Acute bowel ischemia after heart operations.

    PubMed

    Lorusso, Roberto; Mariscalco, Giovanni; Vizzardi, Enrico; Bonadei, Ivano; Renzulli, Attilio; Gelsomino, Sandro

    2014-06-01

    Acute bowel ischemia is a perioperative complication that is frequently unrecognized as a cause of death after cardiac surgical procedures, with an in-hospital mortality of 50% to 100%. In recent years, controversy regarding the most appropriate approach to resolve clinical or laboratory suspicion and the limited therapeutic options have led to very little improvement in patient prognosis. This article reviews the related literature examining the actual prevalence, pathophysiologic mechanisms, predisposing factors, diagnostic tests, and therapeutic approaches providing a glance at new promising tools in diagnostic workup.

  3. Utility of optical coherence tomography in the evaluation of monocular visual loss related to retinal ischemia.

    PubMed

    Nolan, Rachel; Narayana, Kannan; Beh, Shin C; Rucker, Janet C; Balcer, Laura J; Galetta, Steven L

    2016-04-01

    We report four patients with monocular visual loss for whom optical coherence tomography (OCT) was helpful in distinguishing the sequelae of retinal artery occlusion from those of primary optic neuropathy. Determinations of the peripapillary retinal nerve fiber layer (RNFL) thickness as well as macular retinal layer thicknesses and architecture were used. The major findings in our patients show that changes in the inner retinal layers (including ganglion cell and inner plexiform layer) with disruption of normal macular architecture supports a diagnosis of retinal artery occlusion. Our results support the use of OCT imaging for patients with monocular visual loss of uncertain etiology; macular imaging as well as peripapillary RNFL thickness measurement can be helpful in differentiating primary retinal disease or ischemia from primary disorders of the optic nerve.

  4. Cannabinoid receptors and TRPA1 on neuroprotection in a model of retinal ischemia.

    PubMed

    Araújo, D S M; Miya-Coreixas, V S; Pandolfo, P; Calaza, K C

    2017-01-01

    Retinal ischemia is a pathological event present in several retinopathies such as diabetic retinopathy and glaucoma, leading to partial or full blindness with no effective treatment available. Since synthetic and endogenous cannabinoids have been studied as modulators of ischemic events in the central nervous system (CNS), the present study aimed to investigate the involvement of cannabinoid system in the cell death induced by ischemia in an avascular (chick) retina. We observed that chick retinal treatment with a combination of WIN 55212-2 and cannabinoid receptor antagonists (either AM251/O-2050 or AM630) decreased the release of lactate dehydrogenase (LDH) induced by retinal ischemia in an oxygen and glucose deprivation (OGD) model. Further, the increased availability of endocannabinoids together with cannabinoid receptor antagonists also had a neuroprotective effect. Surprisingly, retinal exposure to any of these drugs alone did not prevent the release of LDH stimulated by OGD. Since cannabinoids may also activate transient receptor potential (TRP) channels, we investigated the involvement of TRPA1 receptors (TRPA1) in retinal cell death induced by ischemic events. We demonstrated the presence of TRPA1 in the chick retina, and observed an increase in TRPA1 content after OGD, both by western blot and immunohistochemistry. In addition, the selective activation of TRPA1 by mustard oil (MO) did not worsen retinal LDH release induced by OGD, whereas the blockage of TRPA1 completely prevented the extravasation of cellular LDH in ischemic condition. Hence, these results show that during the ischemic event there is an augment of TRPA1, and activation of this receptor is important in cell death induction. The data also indicate that metabotropic cannabinoid receptors, both type 1 and 2, are not involved with the cell death found in the early stages of ischemia. Therefore, the study points to a potential role of TRPA1 as a target for neuroprotective approaches in retinal

  5. Postconditioning with inhaled hydrogen promotes survival of retinal ganglion cells in a rat model of retinal ischemia/reperfusion injury.

    PubMed

    Wang, Ruobing; Wu, Jiangchun; Chen, Zeli; Xia, Fangzhou; Sun, Qinglei; Liu, Lin

    2016-02-01

    Retinal ischemia/reperfusion (I/R) injury plays a crucial role in the pathophysiology of various ocular diseases. Intraperitoneal injection or ocular instillation with hydrogen (H2)-rich saline was recently shown to be neuroprotective in the retina due to its anti-oxidative and anti-inflammatory effects. Our study aims to explore whether postconditioning with inhaled H2 can protect retinal ganglion cells (RGCs) in a rat model of retinal I/R injury. Retinal I/R injury was performed on the right eyes of rats and was followed by inhalation of 67% H2 mixed with 33% oxygen immediately after ischemia for 1h daily for one week. RGC density was counted using haematoxylin and eosin (HE) staining and retrograde labeling with cholera toxin beta (CTB). Visual function was assessed using flash visual evoked potentials (FVEP) and pupillary light reflex (PLR). Potential biomarkers of retinal oxidative stress and inflammatory responses were measured, including the expression of 4-Hydroxynonenalv (4-HNE), interleukin-1 beta (IL1-β) and tumor necrosis factor alpha (TNF-α). HE and CTB tracing showed that the survival rate of RGCs in the H2-treated group was significantly higher than the rate in the I/R group. Rats with H2 inhalation showed better visual function in assessments of FVEP and PLR. Moreover, H2 treatment significantly decreased the number of 4-HNE-stained cells in the ganglion cell layer and inhibited the retinal overexpression of IL1-β and TNF-α that was induced by retinal I/R injury. Our results demonstrate that postconditioning with inhaled high-dose H2 appears to confer neuroprotection against retinal I/R injury via anti-oxidative, anti-inflammatory and anti-apoptosis pathways.

  6. Myeloid differentiation protein 2-dependent mechanisms in retinal ischemia-reperfusion injury.

    PubMed

    Ren, Luqing; Tao, Jianjian; Chen, Huaicheng; Bian, Yang; Yang, Xi; Chen, Gaozhi; Zhang, Xin; Liang, Guang; Wu, Wencan; Song, Zongming; Wang, Yi

    2017-02-15

    Retinal ischemia-reperfusion (I/R) injury is a common pathological process in many eye disorders. Oxidative stress and inflammation play a role in retinal I/R injury. Recent studies show that toll-like receptor 4 (TLR4) is involved in initiating sterile inflammatory response in retinal I/R. However, the molecular mechanism by which TLR4 is activated is not known. In this study, we show that retinal I/R injury involves a co-receptor of TLR4, myeloid differentiation 2 (MD2). Inhibition of MD2 prevented cell death and preserved retinal function following retinal I/R injury. We confirmed these findings using MD2 knockout mice. Furthermore, we utilized human retinal pigment epithelial cells (ARPE-19 cells) to show that oxidative stress-induced cell death as well as inflammatory response are mediated through MD2. Inhibition of MD2 through a chemical inhibitor or knockdown prevented oxidative stress-induced cell death and expression of inflammatory cytokines. Oxidative stress was found to activate TLR4 in a MD2-dependent manner via increasing the expression of high mobility group box 1. In summary, our study shows that oxidative stress in retinal I/R injury can activate TLR4 signaling via MD2, resulting in induction of inflammatory genes and retinal damage. MD2 may represent an attractive therapeutic target for retinal I/R injury.

  7. Altered Calcium Handling and Ventricular Arrhythmias in Acute Ischemia

    PubMed Central

    Baumeister, Peter; Quinn, T. Alexander

    2016-01-01

    Acute ischemia results in deadly cardiac arrhythmias that are a major contributor to sudden cardiac death (SCD). The electrophysiological changes involved have been extensively studied, yet the mechanisms of ventricular arrhythmias during acute ischemia remain unclear. What is known is that during acute ischemia both focal (ectopic excitation) and nonfocal (reentry) arrhythmias occur, due to an interaction of altered electrical, mechanical, and biochemical properties of the myocardium. There is particular interest in the role that alterations in intracellular calcium handling, which cause changes in intracellular calcium concentration and to the calcium transient, play in ischemia-induced arrhythmias. In this review, we briefly summarize the known contributors to ventricular arrhythmias during acute ischemia, followed by an in-depth examination of the potential contribution of altered intracellular calcium handling, which may include novel targets for antiarrhythmic therapy. PMID:28008297

  8. Lower Hemoglobin Concentration Is Associated with Retinal Ischemia and the Severity of Diabetic Retinopathy in Type 2 Diabetes

    PubMed Central

    Traveset, Alicia; Rubinat, Esther; Ortega, Emilio; Alcubierre, Nuria; Vazquez, Beatriz; Hernández, Marta; Jurjo, Carmen; Espinet, Ramon; Ezpeleta, Juan Antonio; Mauricio, Didac

    2016-01-01

    Aims. To assess the association of blood oxygen-transport capacity variables with the prevalence of diabetic retinopathy (DR), retinal ischemia, and macular oedema in patients with type 2 diabetes mellitus (T2DM). Methods. Cross-sectional, case-control study (N = 312) with T2DM: 153 individuals with DR and 159 individuals with no DR. Participants were classified according to the severity of DR and the presence of retinal ischemia or macular oedema. Hematological variables were collected by standardized methods. Three logistic models were adjusted to ascertain the association between hematologic variables with the severity of DR and the presence of retinal ischemia or macular oedema. Results. Individuals with severe DR showed significantly lower hemoglobin, hematocrit, and erythrocyte levels compared with those with mild disease and in individuals with retinal ischemia and macular oedema compared with those without these disorders. Hemoglobin was the only factor that showed a significant inverse association with the severity of DR [beta-coefficient = −0.52, P value = 0.003] and retinal ischemia [beta-coefficient = −0.49, P value = 0.001]. Lower erythrocyte level showed a marginally significant association with macular oedema [beta-coefficient = −0.86, P value = 0.055]. Conclusions. In patients with DR, low blood oxygen-transport capacity was associated with more severe DR and the presence of retinal ischemia. Low hemoglobin levels may have a key role in the development and progression of DR. PMID:27200379

  9. Outcomes of lower extremity bypass performed for acute limb ischemia

    PubMed Central

    Baril, Donald T.; Patel, Virendra I.; Judelson, Dejah R.; Goodney, Philip P.; McPhee, James T.; Hevelone, Nathanael D.; Cronenwett, Jack L.; Schanzer, Andres

    2013-01-01

    Objective Acute limb ischemia remains one of the most challenging emergencies in vascular surgery. Historically, outcomes following interventions for acute limb ischemia have been associated with high rates of morbidity and mortality. The purpose of this study was to determine contemporary outcomes following lower extremity bypass performed for acute limb ischemia. Methods All patients undergoing infrainguinal lower extremity bypass between 2003 and 2011 within hospitals comprising the Vascular Study Group of New England were identified. Patients were stratified according to whether or not the indication for lower extremity bypass was acute limb ischemia. Primary end points included bypass graft occlusion, major amputation, and mortality at 1 year postoperatively as determined by Kaplan-Meier life table analysis. Multivariable Cox proportional hazards models were constructed to evaluate independent predictors of mortality and major amputation at 1 year. Results Of 5712 lower extremity bypass procedures, 323 (5.7%) were performed for acute limb ischemia. Patients undergoing lower extremity bypass for acute limb ischemia were similar in age (66 vs 67; P = .084) and sex (68% male vs 69% male; P = .617) compared with chronic ischemia patients, but were less likely to be on aspirin (63% vs 75%; P < .0001) or a statin (55% vs 68%; P < .0001). Patients with acute limb ischemia were more likely to be current smokers (49% vs 39%; P < .0001), to have had a prior ipsilateral bypass (33% vs 24%; P = .004) or a prior ipsilateral percutaneous intervention (41% vs 29%; P = .001). Bypasses performed for acute limb ischemia were longer in duration (270 vs 244 minutes; P = .007), had greater blood loss (363 vs 272 mL; P < .0001), and more commonly utilized prosthetic conduits (41% vs 33%; P = .003). Acute limb ischemia patients experienced increased in-hospital major adverse events (20% vs 12%; P < .0001) including myocardial infarction, congestive heart failure exacerbation

  10. Annexin A1 nuclear translocation induces retinal ganglion cell apoptosis after ischemia-reperfusion injury through the p65/IL-1β pathway.

    PubMed

    Zhao, Yin; Li, Xing; Gong, Jieling; Li, Lu; Chen, Liwen; Zheng, Lu; Chen, Zhiqi; Shi, Jing; Zhang, Hong

    2017-04-04

    The degeneration of retinal ganglion cells (RGCs) has been identified as a major problem in glaucoma. Previous studies have indicated an association between annexin A1 (ANXA1) and neuronal cell apoptosis, and RGCs apoptosis in acute ischemia-reperfusion was attributed to an increased production of IL-1β. We found that the expression and nuclear translocation of ANXA1 were upregulated in models of acute ischemia-reperfusion in RGCs in vivo. ANXA1 was found to have a promoting effect on the expression of IL-1β in primary cultured RGCs, which could be inhibited by treatment with ANXA1 shRNA or the p65 inhibitor BAY 11-7082. ANXA1 interacted with p65, and recruited it into the nucleus. Chromatin immunoprecipitation assay revealed that ANXA1 accumulated at the IL-1β gene promoter. The reduction of p65 nuclear translocation using a membrane-permeable ANXA1 peptide containing a Ser5Ala mutation led to a decrease in the expression of IL-1β, and acute ischemia-reperfusion induced RGCs apoptosis in vivo. These results indicate that in RGCs, ANXA1 increases IL-1β expression by recruiting p65 to the nucleus, which induces cell apoptosis. The obtained results may help the development of a novel treatment strategy against RGCs apoptosis in acute ischemia-reperfusion injury.

  11. Methods for Acute and Subacute Murine Hindlimb Ischemia

    PubMed Central

    Padgett, Michael E.; McCord, Timothy J.; McClung, Joseph M.; Kontos, Christopher D.

    2016-01-01

    Peripheral artery disease (PAD) is a leading cause of cardiovascular morbidity and mortality in developed countries, and animal models that reliably reproduce the human disease are necessary to develop new therapies for this disease. The mouse hindlimb ischemia model has been widely used for this purpose, but the standard practice of inducing acute limb ischemia by ligation of the femoral artery can result in substantial tissue necrosis, compromising investigators' ability to study the vascular and skeletal muscle tissue responses to ischemia. An alternative approach to femoral artery ligation is the induction of gradual femoral artery occlusion through the use of ameroid constrictors. When placed around the femoral artery in the same or different locations as the sites of femoral artery ligation, these devices occlude the artery over 1-3 days, resulting in more gradual, subacute ischemia. This results in less substantial skeletal muscle tissue necrosis, which may more closely mimic the responses seen in human PAD. Because genetic background influences outcomes in both the acute and subacute ischemia models, consideration of the mouse strain being studied is important in choosing the best model. This paper describes the proper procedure and anatomical placement of ligatures or ameroid constrictors on the mouse femoral artery to induce subacute or acute hindlimb ischemia in the mouse. PMID:27403963

  12. Acute coronary ischemia during alcohol withdrawal: a case report

    PubMed Central

    2011-01-01

    Introduction The potential of alcohol withdrawal to cause acute coronary events is an area that needs the urgent attention of clinicians and researchers. Case presentation We report the case of a 52-year-old heavy-alcohol-using Sri Lankan man who developed electocardiogram changes suggestive of an acute coronary event during alcohol withdrawal. Despite the patient being asymptomatic, subsequent echocardiogram showed evidence of ischemic myocardial dysfunction. We review the literature on precipitation of myocardial ischemia during alcohol withdrawal and propose possible mechanisms. Conclusions Alcohol withdrawal is a commonly observed phenomenon in hospitals. However, the number of cases reported in the literature of acute coronary events occurring during withdrawal is few. Many cases of acute ischemia or sudden cardiac deaths may be attributed to other well known complications of delirium tremens. This is an area needing the urgent attention of clinicians and epidemiologists. PMID:21838872

  13. SURGICAL EMBOLECTOMY FOR FOVEA-THREATENING ACUTE RETINAL ARTERY OCCLUSION

    PubMed Central

    Almeida, David R.P.; Mammo, Zaid; Chin, Eric K.

    2016-01-01

    Purpose: To describe a technique of surgical intraocular embolectomy in patients with acute fovea-threatening branch retinal artery occlusion. Methods: Pars plana vitrectomy with embolectomy involving embolus isolation, dissection, and removal in patients with an acute fovea-threatening arterial occlusion without a patent cilioretinal artery. Results: The surgical technique involves a core vitrectomy. The blocked artery is incised using a microvitreoretinal blade, and microsurgical forceps are used to retrieve the embolus. No significant complications were noted. The study technique offers an excellent safety profile and minimizes the risk of vitreous hemorrhage by carefully dissecting the vascular adventitial sheath and isolating the embolus. Conclusion: Surgical embolectomy is a viable technique for patients with acute fovea-threatening arterial occlusions without patent cilioretinal artery. Careful dissection and retrieval of the embolus minimizes the risk of vitreous hemorrhage, which is an important improvement in previous techniques for management of acute retinal arterial occlusions. PMID:26674278

  14. Visual prognosis following treatment of acute central retinal artery obstruction.

    PubMed Central

    Augsburger, J J; Magargal, L E

    1980-01-01

    The authors report the visual outcome in 34 consecutive cases of treated acute central retinal artery obstruction. Visual acuity equal to or better than 6/30 was recovered in 35% of the cases. The presenting visual acuity and duration of visual impairment appear to correlate with visual prognosis. PMID:7448144

  15. Reversibility of retinal ischemia due to central retinal artery occlusion by hyperbaric oxygen

    PubMed Central

    Hadanny, Amir; Maliar, Amit; Fishlev, Gregory; Bechor, Yair; Bergan, Jacob; Friedman, Mony; Avni, Isaac; Efrati, Shai

    2017-01-01

    Purpose Ischemic retinal damage can be reversed by hyperbaric oxygen therapy (HBOT) as long as irreversible infarction damage has not developed. However, the time window till irreversible damage develops is still unknown. The study aim was to evaluate the effect of HBOT and determine possible markers for irreversible retinal damage. Materials and methods Retrospective analysis of 225 patients treated with HBOT for central retinal artery occlusion (CRAO) in 1999–2015. One hundred and twenty-eight patients fulfilled inclusion/exclusion criteria: age >18 years, symptoms <20 hours, and best-corrected visual acuity (BCVA) <0.5 logMAR. Results Time delay from symptoms to treatment was 7.8±3.8 hours. The BCVA was significantly improved after HBOT, from 2.14±0.50 to 1.61±0.78 (P<0.0001). The proportion of patients with clinically meaningful visual improvement was significantly higher in patients without cherry-red spot (CRS) compared to patients with CRS at presentation (86.0% vs 57.6%, P<0.0001). The percentage of patients with final BCVA better than 1.0 was also significantly higher in patients without CRS vs patients with CRS at presentation (61.0% vs 7.1%, P<0.0001). There was no correlation between CRS and the time from symptoms. HBOT was found to be safe, and only 5.5% of patients had minor, reversible, adverse events. Conclusion HBOT is an effective treatment for non-arteritic CRAO as long as CRS has not formed. The fundus findings, rather than the time delay, should be used as a marker for irreversible damage. PMID:28096655

  16. Clinical Manifestation of Self-Limiting Acute Retinal Necrosis

    PubMed Central

    Brydak-Godowska, Joanna; Borkowski, Piotr; Szczepanik, Szymon; Moneta-Wielgoś, Joanna; Kęcik, Dariusz

    2014-01-01

    Background The purpose of this paper was to present a case series of self-limiting, peripheral acute retinal necrosis and to demonstrate efficacy of treatment with valacyclovir in patients resistant to acyclovir. The diagnosis was made on ophthalmoscopic examination and positive serum tests for herpes viruses. Material/Methods Ten patients (6F and 4M) aged 19–55 years were diagnosed and treated for self-limiting acute retinal necrosis (ARN). The following endpoints were reported: visual outcomes, clinical features, disease progression, treatment, and complications. Patients received only symptomatic treatment because they did not consent to vitreous puncture. Results Peripheral, mild retinitis was diagnosed in all eyes at baseline. Initially, all patients were treated with systemic acyclovir (800 mg, 5 times a day), prednisone (typically 40–60 mg/day), and aspirin in an outpatient setting. In 6 patients, treatment was discontinued at 6 months due to complete resolution of the inflammatory process. Four patients with immune deficiency showed signs and symptoms of chronic inflammation. Two patients did not respond to acyclovir (2 non-responders); however, those patients were successfully treated with valacyclovir. Complete resolution of inflammatory lesions was observed in 8 patients. In 2 patients, the disease progressed despite treatment – 1 female patient after kidney transplant who stopped the prescribed medications, and 1 male patient with SLE and antiphospholipid syndrome who experienced breakthrough symptoms on-treatment. He died due to cerebral venous sinus thrombosis. Neurological complications (encephalitis and meningitis) were observed in 2 female patients. Prophylactic laser photocoagulation was performed in 1 subject. Conclusions A series of cases of self-limiting acute retinal necrosis (ARN) is presented. This clinical form of ARN can resemble toxoplasmic retinitis in some cases. Oral antiviral medications provide an effective alternative to

  17. One of the most urgent vascular circumstances: Acute limb ischemia

    PubMed Central

    Sahin, Muslum; Kirma, Cevat

    2013-01-01

    Acute limb ischemia is a sudden decrease in limb perfusion that threatens limb viability and requires urgent evaluation and management. Most of the causes of acute limb ischemia are thrombosis of a limb artery or bypass graft, embolism from the heart or a disease artery, dissection, and trauma. Assessment determines whether the limb is viable or irreversibly damaged. Prompt diagnosis and revascularization by means of catheter-based thrombolysis or thrombectomy and by surgery reduce the risk of limb loss and mortality. Amputation is performed in patients with irreversible damage. Despite urgent revascularization, amputation rate is 10%–15% in patients during hospitalization, mostly above the knee, and mortality within 1 year is 10%–15% due to the coexisting conditions. PMID:26770694

  18. Testicular ischemia following mesh hernia repair and acute prostatitis

    PubMed Central

    Pietro, Pepe; Francesco, Aragona

    2007-01-01

    We present a case of a man admitted to our Hospital for right acute scrotum that six months before had undergone a right hernioplasty with mesh implantation. Clinical history and testicular color Doppler sonography (CDS) patterns suggested an orchiepididymitis following acute prostatitis. After 48h the clinical picture worsened and testicular CDS showed a decreased telediastolic velocity that suggested testicular ischemia. The patient underwent surgical exploration: spermatic cord appeared stretched by an inflammatory tissue in absence of torsion and releasing of spermatic cord was performed. In patients with genitourinary infection who previously underwent inguinal mesh implantation, testicular CDS follow-up is mandatory. PMID:19718342

  19. GAP-43 expression is upregulated in retinal ganglion cells after ischemia/reperfusion-induced damage.

    PubMed

    Dijk, Frederike; Bergen, Arthur A B; Kamphuis, Willem

    2007-05-01

    In response to injury, the adult mammalian retina shows signs of structural remodeling, possibly in an attempt to preserve or regain some of its functional neural connections. In order to study the mechanisms involved in injury-induced plasticity, we have studied changes in growth associated protein 43 (GAP-43) after retinal ischemia/reperfusion in the rat. GAP-43 is a marker for neuronal remodeling and is involved in synapse formation. Ischemic injury of the rat retina was induced by 60 min of ischemia followed by reperfusion times varying from 2h up to 4 weeks. GAP-43 mRNA levels were significantly increased between 12h and 72 h reperfusion with a peak around 24h. GAP-43 specific antibodies showed that the total amount of GAP-43 labeling in the inner plexiform layer was diminished after 12h of reperfusion by approximately 35% and remained at this level up to 1 week postischemia despite the reduction in thickness of this layer during this period resulting from the ischemia-induced cell loss. At 2 and 4 weeks reperfusion, the amount of labeling was reduced by 70%, simultaneously with a decrease of GAP-43 transcript level. Between 72 h up to 2 weeks postischemia, the induction of intense GAP-43 labeling was observed in NeuN- and beta-tubulin-positive ganglion cell somata and in horizontally and vertically oriented processes in the inner plexiform layer. Ischemia also induced GAP-43 expression in some GFAP-positive Müller cells. Double-labeling showed that in controls and after ischemia GAP-43 was expressed by some amacrine cells of the glycinergic (glycine transporter 1), calretinin-positive, and dopaminergic (tyrosine hydroxylase) subpopulations. No increase of GAP-43 expression levels was found in these amacrine cells. The results demonstrate that ganglion cells show an elevated expression of GAP-43 after ischemia-inflicted damage. These findings suggest a temporal window during which ganglion cells may remodel their neuronal network in the damaged retina.

  20. Protective effects of catalase on retinal ischemia/reperfusion injury in rats.

    PubMed

    Chen, Baihua; Tang, Luosheng

    2011-11-01

    Retinal ischemia/reperfusion (I/R) injury causes profound tissue damage, especially retinal ganglion cell (RGC) death. The aims of the study were to investigate whether catalase (CAT) has a neuroprotective effect on RGC after I/R injury in rats, and to determine the possible antioxidant mechanism. Wistar female rats were randonmized into four groups: normal control group (Control group), retinal I/R with vehicle group (I/R with vehicle group), retinal I/R with AAV-CAT group (I/R with AAV-CAT group), and normal retina with AAV-CAT group (normal with AAV-CAT group). One eye of each rat was pretreated with recombinant adeno-associated virus containing catalase gene (I/R with AAV-CAT group or normal with AAV-CAT group) and recombinant adeno-associated virus containing GFP gene (I/R with vehicle group) by intravitreal injection 21 days before initiation of I/R injury. Retinal I/R injury was induced by elevating intraocular pressure to 100mmHg for 1h. The number of RGC and inner plexiform layer (IPL) thickness were measured by fluorogold retrograde labeling and hematoxylin and eosin staining at 6h, 24h, 72 h and 5d after injury. Hydrogen peroxide (H(2)O(2)), the number of RGC, IPL thickness, malondialdehyde(MDA), 8-hydroxy-2-deoxyguanosine (8-OHdG), CAT activity and nitrotyrosine were measured by fluorescence staining, immunohistochemistry and enzyme-linked immunosorbent assay analysis at 5 days after injury. Electroretinographic (ERG) evaluation was also used. Pretreatment of AAV-CAT significantly decreased the levels of H(2)O(2), MDA, 8-OHdG and nitrotyrosine, increased the catalase activity, and prevented the reduction of a- and b- waves in the I/R with AAV-CAT group compare with the I/R with vehicle group (p<0.01). Catalase attenuated the I/R-induced damage of RGC and IPL and retinal function. Therefore, catalase can protect the rat retina from I/R-induced injury by enhancing the antioxidative ability and reducing oxidative stress, which suggests that catalase may be

  1. Renal oxygenation in acute renal ischemia-reperfusion injury.

    PubMed

    Abdelkader, Amany; Ho, Julie; Ow, Connie P C; Eppel, Gabriela A; Rajapakse, Niwanthi W; Schlaich, Markus P; Evans, Roger G

    2014-05-01

    Tissue hypoxia has been demonstrated, in both the renal cortex and medulla, during the acute phase of reperfusion after ischemia induced by occlusion of the aorta upstream from the kidney. However, there are also recent clinical observations indicating relatively well preserved oxygenation in the nonfunctional transplanted kidney. To test whether severe acute kidney injury can occur in the absence of widespread renal tissue hypoxia, we measured cortical and inner medullary tissue Po2 as well as total renal O2 delivery (Do2) and O2 consumption (Vo2) during the first 2 h of reperfusion after 60 min of occlusion of the renal artery in anesthetized rats. To perform this experiment, we used a new method for measuring kidney Do2 and Vo2 that relies on implantation of fluorescence optodes in the femoral artery and renal vein. We were unable to detect reductions in renal cortical or inner medullary tissue Po2 during reperfusion after ischemia localized to the kidney. This is likely explained by the observation that Vo2 (-57%) was reduced by at least as much as Do2 (-45%), due to a large reduction in glomerular filtration (-94%). However, localized tissue hypoxia, as evidence by pimonidazole adduct immunohistochemistry, was detected in kidneys subjected to ischemia and reperfusion, particularly in, but not exclusive to, the outer medulla. Thus, cellular hypoxia, particularly in the outer medulla, may still be present during reperfusion even when reductions in tissue Po2 are not detected in the cortex or inner medulla.

  2. Nonlinear Dynamic Theory of Acute Cell Injuries and Brain Ischemia

    NASA Astrophysics Data System (ADS)

    Taha, Doaa; Anggraini, Fika; Degracia, Donald; Huang, Zhi-Feng

    2015-03-01

    Cerebral ischemia in the form of stroke and cardiac arrest brain damage affect over 1 million people per year in the USA alone. In spite of close to 200 clinical trials and decades of research, there are no treatments to stop post-ischemic neuron death. We have argued that a major weakness of current brain ischemia research is lack of a deductive theoretical framework of acute cell injury to guide empirical studies. A previously published autonomous model based on the concept of nonlinear dynamic network was shown to capture important facets of cell injury, linking the concept of therapeutic to bistable dynamics. Here we present an improved, non-autonomous formulation of the nonlinear dynamic model of cell injury that allows multiple acute injuries over time, thereby allowing simulations of both therapeutic treatment and preconditioning. Our results are connected to the experimental data of gene expression and proteomics of neuron cells. Importantly, this new model may be construed as a novel approach to pharmacodynamics of acute cell injury. The model makes explicit that any pro-survival therapy is always a form of sub-lethal injury. This insight is expected to widely influence treatment of acute injury conditions that have defied successful treatment to date. This work is supported by NIH NINDS (NS081347) and Wayne State University President's Research Enhancement Award.

  3. Role of C/EBP Homologous Protein in Retinal Ganglion Cell Death After Ischemia/Reperfusion Injury

    PubMed Central

    Nashine, Sonali; Liu, Yang; Kim, Byung-Jin; Clark, Abbot F.; Pang, Iok-Hou

    2015-01-01

    Purpose. To investigate the role of C/EBP homologous protein (CHOP), a proapoptotic protein, and the unfolded protein response (UPR) marker that is involved in endoplasmic reticulum (ER) stress-mediated apoptosis in mouse retinal ganglion cell (RGC) death following ischemia/reperfusion (I/R) injury. Methods. Retinal I/R injury was induced in adult C57BL/6J wild-type (WT) and CHOP knockout (Chop−/−) mice by raising IOP to 120 mm Hg for 60 minutes. Expression of CHOP and other UPR markers was studied by Western blot and immunohistochemistry. Retinal ganglion cell counts were performed in retinal flat mounts stained with an RGC marker. Retinal ganglion cell function was evaluated by scotopic threshold response (STR) electroretinography. Results. In WT mice, retinal CHOP was upregulated by 30% in I/R-injured eyes compared to uninjured eyes 3 days after injury (P < 0.05). Immunohistochemistry confirmed CHOP upregulation specifically in RGCs. CHOP knockout did not affect baseline RGC density or STR amplitude. Ischemia/reperfusion injury decreased RGC densities and STR amplitudes in both WT and Chop−/− mice. However, survival of RGCs in I/R-injured Chop−/− mouse was 48% higher (P < 0.05) than that in I/R-injured WT mouse 3 days after I/R injury. Similarly, RGC density was significantly higher in Chop−/− eyes at 7, 14, and 28 days after I/R injury. Scotopic threshold response amplitudes of Chop−/− mice were significantly higher at 3 and 7 days after I/R than those of WT mice. Conclusions. Absence of CHOP partially protects against RGC loss and reduction in retinal function after I/R injury, indicating that CHOP and, thus, ER stress play an important role in RGC apoptosis in retinal I/R injury. PMID:25414185

  4. Adult midgut malrotation presented with acute bowel obstruction and ischemia

    PubMed Central

    Zengin, Akile; Uçar, Bercis İmge; Düzgün, Şükrü Aydın; Bayhan, Zülfü; Zeren, Sezgin; Yaylak, Faik; Şanal, Bekir; Bayhan, Nilüfer Araz

    2016-01-01

    Introduction Intestinal malrotation refers to the partial or complete failure of rotation of midgut around the superior mesenteric vessels in embryonic life. Arrested midgut rotation results due to narrow-based mesentery and increases the risk of twisting midgut and subsequent obstruction and necrosis. Presentation of case 40 years old female patient admitted to emergency service with acute abdomen and computerized tomography scan showed dilated large and small intestine segments with air-fluid levels and twisted mesentery around superior mesenteric artery and vein indicating “whirpool sign”. Discussion Malrotation in adults is a rare cause of midgut volvulus as though it should be considered in differential diagnosis in patients presented with acute abdomen and intestinal ischemia. Even though clinical symptoms are obscure, adult patients usually present with vomiting and recurrent abdominal pain due to chronic partial obstruction. Contrast enhanced radiograph has been shown to be the most accurate method. Typical radiological signs are corkscrew sign, which is caused by the dilatation of various duodenal segments at different levels and the relocation of duodenojejunal junction due to jejunum folding. As malrotation commonly causes intestinal obstruction, patients deserve an elective laparotomy. Conclusion Malrotation should be considered in differential diagnosis in patients presented with acute abdomen and intestinal ischemia. Surgical intervention should be prompt to limit morbidity and mortality. PMID:27015011

  5. Thallium-201 myocardial scintigraphy in acute myocardial infarction and ischemia

    SciTech Connect

    Wackers, F.J.

    1982-04-01

    Thallium-201 scintigraphy provides a sensitive and reliable method of detecting acute myocardial infarction and ischemia when imaging is performed with understanding of the temporal characteristics and accuracy of the technique. The results of scintigraphy are related to the time interval between onset of symptoms and time of imaging. During the first 6 hr after chest pain almost all patients with acute myocardial infarction and approximately 50% of the patients with unstable angina will demonstrate /sup 201/TI pefusion defects. Delayed imaging at 2-4 hr will permit distinction between ischemia and infarction. In patients with acute myocardial infarction, the size of the perfusion defect accurately reflects the extent of the infarcted and/or jeopardized myocardium, which may be used for prognostic stratification. In view of the characteristics of /sup 201/TI scintigraphy, the most practical application of this technique is in patients in whom myocardial infarction has to be ruled out, and for early recognition of patients at high risk for complications.

  6. Acute arterial ischemia in a patient with polyarthritis.

    PubMed

    Soro Marín, Sandra; Júdez Navarro, Enrique; Alamillo Sanz, Antonio Salvador; Sánchez Nievas, Ginés

    Cryoglobulins are immunoglobulins that precipitate at cold temperatures. Their presence can be related to a type of vasculitis referred to as cryoglobulinemia. This condition, especially mixed cryoglobulinemia, has been associated with viral infections like hepatitis C virus in 60%-90% of cases, but it has also been reported in relation to connective tissue diseases, usually resulting in a more severe course. We describe the case of a patient with seronegative polyarthritis who developed acute arterial ischemia in association with cryoglobulinemia, with a good response to rituximab therapy.

  7. Quantification of retinal layer thickness changes in acute macular neuroretinopathy

    PubMed Central

    Munk, Marion R; Beck, Marco; Kolb, Simone; Larsen, Michael; Hamann, Steffen; Valmaggia, Christophe; Zinkernagel, Martin S

    2017-01-01

    Purpose To quantitatively evaluate retinal layer thickness changes in acute macular neuroretinopathy (AMN). Methods AMN areas were identified using near-infrared reflectance (NIR) images. Intraretinal layer segmentation using Heidelberg software was performed. The inbuilt ETDRS -grid was moved onto the AMN lesion and the mean retinal layer thicknesses of the central grid were recorded and compared with the corresponding area of the fellow eye at initial presentation and during follow-up. Results Eleven patients were included (mean age 26±6 years). AMN lesions at baseline had a significantly thinner outer nuclear layer (ONL) (51±21 µm vs 73±17 µm, p=0.002). The other layers, including inner nuclear layer (37±8 µm vs 38±6 µm, p=0.9) and outer plexiform layer (OPL) (45±19 µm vs 33±16 µm, p=0.1) did not show significant differences between the study eyes and fellow eyes. Adjacent to NIR image lesions, areas of OPL thickening were identified (study eye: 50±14 µm vs fellow eye: 39±16 µm, p=0.005) with corresponding thinning of ONL (study eye: 52±16 µm vs fellow eye: 69±16 µm, p=0.002). Conclusions AMN presents with characteristic quantitative retinal changes and the extent of the lesion may be more extensive than initially presumed from NIR image lesions. PMID:27170518

  8. Acute digital ischemia: A rare presentation of antisynthetase syndrome

    PubMed Central

    Chan, Jin Ei; Palakodeti, Sandeep; Koster, Matthew J.

    2017-01-01

    Antisynthetase syndrome (ASS) is recognized as a subgroup of idiopathic inflammatory myopathies (IIMs). It is associated with autoantibodies directed against aminoacyl-transfer ribonucleic acid (tRNA) synthetase enzymes. We report the first case of anti-PL-7/anti-SSA 52kD ASS presenting as acute digital ischemia, an association not described previously. Occlusive vasculopathy is a rare but serious manifestation that can be seen at presentation in patients with ASS and may herald the onset of severe interstitial lung disease (ILD). Comprehensive evaluation should be performed to confirm the presence of subclinical myositis. Extensive myositis-specific antibody testing is strongly recommended even if initial screening autoimmune serologies are unrevealing. PMID:28293456

  9. Acute digital ischemia: A rare presentation of antisynthetase syndrome.

    PubMed

    Chan, Jin Ei; Palakodeti, Sandeep; Koster, Matthew J

    2017-03-01

    Antisynthetase syndrome (ASS) is recognized as a subgroup of idiopathic inflammatory myopathies (IIMs). It is associated with autoantibodies directed against aminoacyl-transfer ribonucleic acid (tRNA) synthetase enzymes. We report the first case of anti-PL-7/anti-SSA 52kD ASS presenting as acute digital ischemia, an association not described previously. Occlusive vasculopathy is a rare but serious manifestation that can be seen at presentation in patients with ASS and may herald the onset of severe interstitial lung disease (ILD). Comprehensive evaluation should be performed to confirm the presence of subclinical myositis. Extensive myositis-specific antibody testing is strongly recommended even if initial screening autoimmune serologies are unrevealing.

  10. Successful Percutaneous Transluminal Angioplasty and Stenting in Acute Mesenteric Ischemia

    SciTech Connect

    Gartenschlaeger, Soeren Bender, Siegfried; Maeurer, Juergen; Schroeder, Ralf J.

    2008-03-15

    Acute mesenteric ischemia (AMI) is a life-threatening emergency. The complications are high by the time of diagnosis in most cases and therefore only few data on primary percutaneous intervention with percutaneous transluminal angioplasty (PTA) and stenting in AMI are available. We present the case of an 84-year-old woman who presented to our emergency department complaining of an acute worsening of pre-existing abdominal periumbilical pain, nausea, vomiting, and diarrhea. She had previously undergone percutaneous transluminal embolectomy for an acute occlusion of the left common femoral artery. Due to suspicion of intestinal infarction, conventional angiography of the aorta and the superior mesenteric artery (SMA) was performed and confirmed a proximal occlusion of the SMA. Percutaneous SMA recanalization with balloon dilation and subsequent stent implantation was carried out successfully. The abdominal symptoms subsided after this procedure. In AMI that is diagnosed early, endovascular stenting should be considered as an alternative treatment to the surgical approach that avoids the need for surgical bowel resection.

  11. N-Acetylcysteine and Acute Retinal Laser Lesion in the Colubrid Snake Eye

    DTIC Science & Technology

    2004-01-01

    immune response to acute laser injury. When we applied a thiol antioxidant, N- acetylcysteine ( NAC ) systemically, after the lesion but before the dyes... acetylcysteine on fluorescence, induced by the dye C-400, in acute retinal laser injury. Dye alone on the left. Dye plus NAC on the right. In the first two...UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP020041 TITLE: N- Acetylcysteine and Acute Retinal Laser Lesion in the

  12. Antiviral selection in the management of acute retinal necrosis

    PubMed Central

    Tam, Patrick MK; Hooper, Claire Y; Lightman, Susan

    2010-01-01

    There is no consensus on the optimal antiviral regimen in the management of acute retinal necrosis, a disease caused by herpetic viruses with devastating consequences for the eye. The current gold standard is based on retrospective case series. Because the incidence of disease is low, few well-designed, randomized trials have evaluated treatment dosage and duration. Newer oral antiviral agents are emerging as alternatives to high-dose intravenous acyclovir, avoiding the need for inpatient intravenous treatment. Drug resistance is uncommon but may also be difficult to identify. Antiviral drugs have few side effects, but special attention needs to be paid to patients who have underlying renal disease, are pregnant or are immunocompromised. PMID:20169044

  13. Acute Hypoglycemia Induces Retinal Cell Death in Mouse

    PubMed Central

    Emery, Martine; Schorderet, Daniel F.; Roduit, Raphaël

    2011-01-01

    Background Glucose is the most important metabolic substrate of the retina and maintenance of normoglycemia is an essential challenge for diabetic patients. Glycemic excursions could lead to cardiovascular disease, nephropathy, neuropathy and retinopathy. A vast body of literature exists on hyperglycemia namely in the field of diabetic retinopathy, but very little is known about the deleterious effect of hypoglycemia. Therefore, we decided to study the role of acute hypoglycemia in mouse retina. Methodology/Principal Findings To test effects of hypoglycemia, we performed a 5-hour hyperinsulinemic/hypoglycemic clamp; to exclude an effect of insulin, we made a hyperinsulinemic/euglycemic clamp as control. We then isolated retinas from each group at different time-points after the clamp to analyze cells apoptosis and genes regulation. In parallel, we used 661W photoreceptor cells to confirm in vivo results. We showed herein that hypoglycemia induced retinal cell death in mouse via caspase 3 activation. We then tested the mRNA expression of glutathione transferase omega 1 (Gsto1) and glutathione peroxidase 3 (Gpx3), two genes involved in glutathione (GSH) homeostasis. The expression of both genes was up-regulated by low glucose, leading to a decrease of reduced glutathione (GSH). In vitro experiments confirmed the low-glucose induction of 661W cell death via superoxide production and activation of caspase 3, which was concomitant with a decrease of GSH content. Moreover, decrease of GSH content by inhibition with buthionine sulphoximine (BSO) at high glucose induced apoptosis, while complementation with extracellular glutathione ethyl ester (GSHee) at low glucose restored GSH level and reduced apoptosis. Conclusions/Significance We showed, for the first time, that acute insulin-induced hypoglycemia leads to caspase 3-dependant retinal cell death with a predominant role of GSH content. PMID:21738719

  14. Acute necrotizing retinal vasculitis as onset of systemic lupus erythematosus

    PubMed Central

    Monov, Simeon; Hristova, Ruska; Dacheva, Rositza; Toncheva, Reni; Shumnalieva, Russka; Shoumnalieva-Ivanova, Viara; Monova, Daniela

    2017-01-01

    Abstract Rationale: Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by autoantibody production, complement activation, and deposition of immune complexes in tissues and organs. SLE can involve any region of the visual system. Although ocular manifestations are not part of the classification criteria for SLE, they can be observed in up to one-third of the patients with SLE. They are rarely reported at the time of disease onset. Retinal vasculitis is usually associated with active generalized disease. Due to its low frequency, we report a case of acute necrotizing retinal vasculitis as onset of SLE. Patient concerns and diagnosis: A 25-year-old white female was referred to the rheumatology clinic with gradually and rapid deterioration of the vision due to abnormal vessel permeability in the right fundus with edema along the vessels, occlusion of arterial branches in the middle periphery with leakage of the dye in these areas and indentical but less prominent changes with cotton wool spots in the papillomacular area and extensive hemorrhages in the left eye. The onset of malar rash, arthralgias and positive antinuclear, anti-double stranded DNA, anti-ribosomal P and anti-β2 glycoprotein I antibodies with decreased C4 complement levels, as well as the positive lupus-band test confirmed the diagnosis of SLE. Interventions: Aggressive immunomodulating therapy with high-dose methylprednisolone, intravenous immunoglobulin, and cyclophosphamide was used for suppression of the disease activity followed by azathioprine as maintaince therapy. Outcomes: Substantial improvement and partial resorption of the vasculitic changes, including central retinal artery and vein, was achieved prominently in the left eye. The study was conducted in accordance with the Declaration of Helsinki and written informed consent was obtained from the patient. Because of this, there is no need to conduct special ethic review and the ethical approval is not necessary

  15. [Atypical case of acute retinal necrosis secondary to the primary herpes simplex infection].

    PubMed

    Terelak-Borys, Barbara; Krzyźewska-Niedzialek, Aldona; Jamrozy-Witkowska, Agnieszka; Borkowski, Piotr K; Ulińska, Magdalena; Grabska-Liberek, Iwona

    2015-01-01

    Acute retinal necrosis is a rare manifestation of viral chorioretinitis, accompanied by occlusive vasculitis, which is associated with poor visual prognosis. The main causal factors include varicella-zoster virus in older patients and herpes simplex in younger ones. The disease typically manifests as a reactivation of latent infections. We present a case of a 57-year-old female with atypical clinical manifestation of acute retinal necrosis secondary to the primary viral infection with herpes simplex. The serology panel of vitreous tap and blood sample confirmed viral aetiology (H. simplex). The initial clinical signs included optic disc edema with retinitis presenting as self-limiting, slowly progressing, peripheral lesions, later followed by uveitis. The antiviral therapy resolved the symptoms of uveitis and enabled healing of retinal lesions, however the natural course of disease was later complicated with retinal detachment. It was successfully treated with vitreoretinal surgery. Despite aggressive treatment, the final visual outcome was unfavourable, due to optic nerve atrophy.

  16. Compound 49b Restores Retinal Thickness and Reduces Degenerate Capillaries in the Rat Retina following Ischemia/Reperfusion.

    PubMed

    Liu, Li; Jiang, Youde; Steinle, Jena J

    2016-01-01

    We have recently reported that Compound 49b, a novel β-adrenergic receptor agonist, can significantly reduce VEGF levels in retinal endothelial cells (REC) grown in diabetic-like conditions. In this study, we investigated whether Compound 49b could protect the retina under hypoxic conditions using the ischemia-reperfusion (I/R)-induced model in rats, as well REC cultured in hypoxic conditions. Some rats received 1mM topical Compound 49b for the 2 (5 rats each group) or 10 (4 rats in each group) days post-I/R. Analyses for retinal thickness and cell loss in the ganglion cell layer was done at 2 days post-I/R, while numbers of degenerate capillaries and pericyte ghosts were measured at 10 days post-I/R. Additionally, REC were cultured in normal oxygen or hypoxia (5% O2) only or treated with 50 nM Compound 49b for 12 hours. Twelve hours after Compound 49b exposure, cells were collected and analyzed for protein levels of insulin-like growth factor binding protein 3 (IGFBP-3), vascular endothelial cell growth factor (VEGF) and its receptor (KDR), angiopoietin 1 and its receptor Tie2 for Western blotting. Data indicate that exposure to I/R significantly decreased retinal thickness, with increasing numbers of degenerate capillaries and pericyte ghosts. Compound 49b treatment inhibited these retinal changes. In REC cultured in hypoxia, levels of IGFBP-3 were reduced, which were significantly increased by Compound 49b. Hypoxia significantly increased protein levels of VEGF, KDR, Angiopoiein 1, and Tie2, which were reduced following Compound 49b treatment. These data strongly suggested that Compound 49b protected the retina against I/R-induced injury. This provides additional support for a role of β-adrenergic receptor actions in the retina.

  17. Effect of hydrogen sulfide on inflammatory cytokines in acute myocardial ischemia injury in rats

    PubMed Central

    LIU, FANG; LIU, GUANG-JIE; LIU, NA; ZHANG, GANG; ZHANG, JIAN-XIN; LI, LAN-FANG

    2015-01-01

    Hydrogen sulfide (H2S) is believed to be involved in numerous physiological and pathophysiological processes, and now it is recognized as the third endogenous signaling gasotransmitter, following nitric oxide and carbon monoxide; however, the effects of H2S on inflammatory factors in acute myocardial ischemia injury in rats have not been clarified. In the present study, sodium hydrosulfide (NaHS) was used as the H2S donor. Thirty-six male Sprague Dawley rats were randomly divided into five groups: Sham, ischemia, ischemia + low-dose (0.78 mg/kg) NaHS, ischemia + medium-dose (1.56 mg/kg) NaHS, ischemia + high-dose (3.12 mg/kg) NaHS and ischemia + propargylglycine (PPG) (30 mg/kg). The rats in each group were sacrificed 6 h after the surgery for sample collection. Compared with the ischemia group, the cardiac damage in the rats in the ischemia + NaHS groups was significantly reduced, particularly in the high-dose group; in the ischemia + PPG group, the myocardial injury was aggravated compared with that in the ischemia group. Compared with the ischemia group, the levels of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) in the serum of rats in the ischemia + medium- and high-dose NaHS groups were significantly reduced, and the expression of intercellular adhesion molecule-1 (ICAM-1) mRNA and nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) protein in the myocardial tissues of rats was significantly reduced. In the ischemia + PPG group, the TNF-α, IL-1β and IL-6 levels in the serum were significantly increased, the expression of ICAM-1 mRNA was increased, although without a significant difference, and the expression of NF-κB was increased. The findings of the present study provide novel evidence for the dual effects of H2S on acute myocardial ischemia injury via the modulation of inflammatory factors. PMID:25667680

  18. Acute retinal necrosis complicating chicken pox in a healthy adult: a case report and review of literature.

    PubMed

    Tajunisah, Iqbal; Reddy, Sagili Chandrasekhara

    2007-01-01

    We report a case of unilateral acute retinal necrosis (ARN) with marked vitritis and retinal necrosis leading to retinal breaks following chicken pox successfully treated with intravenous acyclovir followed by oral acyclovir, orbital floor triamcinolone injections to contain the inflammation, and barrier laser therapy to secure the retinal breaks with good visual outcome. This case is unusual in its severity and the novel use orbital floor triamcinolone therapy to contain ARN inflammation.

  19. A method and technical equipment for an acute human trial to evaluate retinal implant technology

    NASA Astrophysics Data System (ADS)

    Hornig, Ralf; Laube, Thomas; Walter, Peter; Velikay-Parel, Michaela; Bornfeld, Norbert; Feucht, Matthias; Akguel, Harun; Rössler, Gernot; Alteheld, Nils; Lütke Notarp, Dietmar; Wyatt, John; Richard, Gisbert

    2005-03-01

    This paper reports on methods and technical equipment to investigate the epiretinal stimulation of the retina in blind human subjects in acute trials. Current is applied to the retina through a thin, flexible microcontact film (microelectrode array) with electrode diameters ranging from 50 to 360 µm. The film is mounted in a custom-designed surgical tool that is hand-held by the surgeon during stimulation. The eventual goal of the work is the development of a chronically implantable retinal prosthesis to restore a useful level of vision to patients who are blind with outer retinal degenerations, specifically retinitis pigmentosa and macular degeneration.

  20. Association between retinal hemorrhagic pattern and macular perfusion status in eyes with acute branch retinal vein occlusion

    PubMed Central

    Muraoka, Yuki; Uji, Akihito; Tsujikawa, Akitaka; Murakami, Tomoaki; Ooto, Sotaro; Suzuma, Kiyoshi; Takahashi, Ayako; Iida, Yuto; Miwa, Yuko; Hata, Masayuki; Yoshimura, Nagahisa

    2016-01-01

    This prospective study included 63 eyes with acute branch retinal vein occlusion (BRVO) to evaluate the retinal hemorrhagic patterns at the posterior poles and explore their clinical relevance in macular perfusion differentiation. Retinal hemorrhagic patterns and macular perfusion status were evaluated via fundus photography and fluorescein angiography, respectively. Macular perfusion was judged as nonischemic in 30, ischemic in 28, and undeterminable in 5 among the 63 eyes. Predominant hemorrhagic patterns were flame-shaped in 39 (67.2%) and non-flame-shaped in 19 (32.8%) eyes. All 39 eyes with a flame-shaped hemorrhage showed a nonischemic macula. Of the 19 eyes classified as having a non-flame-shaped hemorrhage, 13 (68.4%) had an ischemic macula and 6 (31.6%) had a nonischemic macula (P < 0.001). Parallelism in eyes with a flame-shaped hemorrhage was higher than in those with a non-flame-shaped hemorrhage (P < 0.001), and in those with a nonischemic macula versus those with an ischemic macula (P < 0.001). The area under the curve for parallelism was 0.975 (P < 0.001), suggesting an accurate diagnostic parameter for macular perfusion differentiation. In conclusion, we objectively evaluated retinal hemorrhagic patterns at the posterior pole in BRVO using the parallelism method, which was useful in differentiating macular perfusion status. PMID:27334338

  1. Pretreatment with low doses of acenocoumarol inhibits the development of acute ischemia/reperfusion-induced pancreatitis.

    PubMed

    Warzecha, Z; Sendur, P; Ceranowicz, P; Dembinski, M; Cieszkowski, J; Kusnierz-Cabala, B; Tomaszewska, R; Dembinski, A

    2015-10-01

    Coagulative disorders are known to occur in acute pancreatitis and are related to the severity of this disease. Various experimental and clinical studies have shown protective and therapeutic effect of heparin in acute pancreatitis. Aim of the present study was to determine the influence of acenocoumarol, a vitamin K antagonist, on the development of acute pancreatitis. Studies were performed on male Wistar rats weighing 250 - 270 g. Acenocoumarol at the dose of 50, 100 or 150 μg/kg/dose or vehicle were administered once a day for 7 days before induction of acute pancreatitis. Acute pancreatitis was induced in rats by pancreatic ischemia followed by reperfusion. The severity of acute pancreatitis was assessed after 5-h reperfusion. Pretreatment with acenocoumarol given at the dose of 50 or 100 μg/kg/dose reduced morphological signs of acute pancreatitis. These effects were accompanied with a decrease in the pancreatitis-evoked increase in serum activity of lipase and serum concentration of pro-inflammatory interleukin-1β. Moreover, the pancreatitis-evoked reductions in pancreatic DNA synthesis and pancreatic blood flow were partially reversed by pretreatment with acenocoumarol given at the dose of 50 and 100 μg/kg/dose. Administration of acenocoumarol at the dose of 150 μg/kg/dose did not exhibit any protective effect against ischemia/reperfusion-induced pancreatitis. We concluded that pretreatment with low doses of acenocoumarol reduces the severity of ischemia/reperfusion-induced acute pancreatitis.

  2. Cathepsin L acutely alters microvessel integrity within the neurovascular unit during focal cerebral ischemia

    PubMed Central

    Gu, Yu-Huan; Kanazawa, Masato; Hung, Stephanie Y; Wang, Xiaoyun; Fukuda, Shunichi; Koziol, James A; del Zoppo, Gregory J

    2015-01-01

    During focal cerebral ischemia, the degradation of microvessel basal lamina matrix occurs acutely and is associated with edema formation and microhemorrhage. These events have been attributed to matrix metalloproteinases (MMPs). However, both known protease generation and ligand specificities suggest other participants. Using cerebral tissues from a non-human primate focal ischemia model and primary murine brain endothelial cells, astrocytes, and microglia in culture, the effects of active cathepsin L have been defined. Within 2 hours of ischemia onset cathepsin L, but not cathepsin B, activity appears in the ischemic core, around microvessels, within regions of neuron injury and cathepsin L expression. In in vitro studies, cathepsin L activity is generated during experimental ischemia in microglia, but not astrocytes or endothelial cells. In the acidic ischemic core, cathepsin L release is significantly increased with time. A novel ex vivo assay showed that cathepsin L released from microglia during ischemia degrades microvessel matrix, and interacts with MMP activity. Hence, the loss of microvessel matrix during ischemia is explained by microglial cathepsin L release in the acidic core during injury evolution. The roles of cathepsin L and its interactions with specific MMP activities during ischemia are relevant to strategies to reduce microvessel injury and hemorrhage. PMID:26198177

  3. The role of excessive versus acute administration of erythropoietin in attenuating hepatic ischemia-reperfusion injury.

    PubMed

    Pappo, Orit; Ben-Ari, Ziv; Shevtsov, Evgeni; Avlas, Orna; Gassmann, Max; Ravid, Amiram; Cheporko, Yelena; Hochhauser, Edith

    2010-12-01

    Ischemia-reperfusion injury (I/R) is the main cause of primary graft nonfunction. Our aim was to evaluate the effect of excessive versus acute administration of erythropoietin (EPO) in attenuating the hepatic injury induced by I/R in mice. The effect of segmental (70%) hepatic ischemia was evaluated in a transgenic mouse line with constitutive overexpression of human EPO cDNA and in wild-type (WT) mice. Mice were randomly allocated to 5 main experimental groups: (i) WT-sham, (ii) WT ischemia, (iii) WT ischemia + recombinant human erythropoietin (rhEPO), (iv) transgenic-sham, and (v) transgenic ischemia. The EPO-pretreated mice showed a significant reduction in liver enzyme levels and intrahepatic caspase-3 activity and fewer apoptotic hepatocytes (p < 0.05 for all) compared with the WT untreated I/R group. EPO decreased c-Jun N-terminal kinase (JNK) phosphorylation and nuclear factor-κB (NF-κB) expression during I/R. In transgenic I/R livers, baseline histology showed diffused hepatic injury, and no significant beneficial effect was noted between the WT untreated and the transgenic I/R mice. In conclusion, acute pretreatment with EPO in WT mice attenuated in vivo I/R liver injury. However, in excessive EPO overexpression, the initial liver injury abolished the beneficial effect of EPO. These findings have important implications for the potential use of acute EPO in I/R injury during liver transplantation.

  4. Argon Inhalation Attenuates Retinal Apoptosis after Ischemia/Reperfusion Injury in a Time- and Dose-Dependent Manner in Rats

    PubMed Central

    Ulbrich, Felix; Schallner, Nils; Coburn, Mark; Loop, Torsten; Lagrèze, Wolf Alexander; Biermann, Julia; Goebel, Ulrich

    2014-01-01

    Purpose Retinal ischemia and reperfusion injuries (IRI) permanently affect neuronal tissue and function by apoptosis and inflammation due to the limited regenerative potential of neurons. Recently, evidence emerged that the noble gas Argon exerts protective properties, while lacking any detrimental or adverse effects. We hypothesized that Argon inhalation after IRI would exert antiapoptotic effects in the retina, thereby protecting retinal ganglion cells (RGC) of the rat's eye. Methods IRI was performed on the left eyes of rats (n = 8) with or without inhaled Argon postconditioning (25, 50 and 75 Vol%) for 1 hour immediately or delayed after ischemia (i.e. 1.5 and 3 hours). Retinal tissue was harvested after 24 hours to analyze mRNA and protein expression of Bcl-2, Bax and Caspase-3, NF-κB. Densities of fluorogold-prelabeled RGCs were analyzed 7 days after injury in whole-mounts. Histological tissue samples were prepared for immunohistochemistry and blood was analyzed regarding systemic effects of Argon or IRI. Statistics were performed using One-Way ANOVA. Results IRI induced RGC loss was reduced by Argon 75 Vol% inhalation and was dose-dependently attenuated by lower concentrations, or by delayed Argon inhalation (1504±300 vs. 2761±257; p<0.001). Moreover, Argon inhibited Bax and Bcl-2 mRNA expression significantly (Bax: 1.64±0.30 vs. 0.78±0.29 and Bcl-2: 2.07±0.29 vs. 0.99±0.22; both p<0.01), as well as caspase-3 cleavage (1.91±0.46 vs. 1.05±0.36; p<0.001). Expression of NF-κB was attenuated significantly. Immunohistochemistry revealed an affection of Müller cells and astrocytes. In addition, IRI induced leukocytosis was reduced significantly after Argon inhalation at 75 Vol%. Conclusion Immediate and delayed Argon postconditioning protects IRI induced apoptotic loss of RGC in a time- and dose-dependent manner, possibly mediated by the inhibition of NF-κB. Further studies need to evaluate Argon's possible role as a therapeutic option. PMID

  5. Role of the femorofemoral crossover graft in acute lower limb ischemia due to acute type B aortic dissection.

    PubMed

    Corfield, Lorraine; McCormack, David J; Bell, Rachel; Taylor, Peter; Reidy, John

    2014-04-01

    Acute limb ischemia due to type B aortic dissection is rare and continues to be a management challenge. A case series is presented here with the aim of assessing the outcomes of treatment with a femorofemoral crossover graft with or without thoracic stent graft insertion. This is a combined retrospective and prospective review of nine cases of acute lower limb ischemia secondary to acute type B aortic dissection. The presenting features, radiological findings, treatment and outcomes were reviewed. Five patients had a femorofemoral crossover graft (FFXO) alone, two an FFXO with a thoracic stent graft and the eighth a thoracic and iliac stent. The other case was initially treated conservatively but subsequently required an FFXO. The mean follow-up was 16 (3-51) months. A further two thoracic stents were placed during the follow-up period. Thus five out of nine patients (56%) required aortic stenting. This series suggests that an FFXO is a reliable treatment for acute limb ischemia due to type B aortic dissection. However, these patients are often complex with ischemia in other vascular beds and are at risk of subsequent aneurysmal dilation.

  6. Management of acute central retinal artery occlusion: Intravenous thrombolysis is feasible and safe.

    PubMed

    Préterre, Cécile; Godeneche, Gaelle; Vandamme, Xavier; Ronzière, Thomas; Lamy, Matthias; Breuilly, Christophe; Urbanczyk, Cédric; Wolff, Valérie; Lebranchu, Pierre; Sevin-Allouet, Mathieu; Guillon, Benoit

    2017-01-01

    Background Although acute central retinal artery occlusion is as a stroke in the carotid territory (retinal artery), its management remains controversial. The aim of this study was to assess the feasibility and safety of intravenous thrombolysis delivered within 6 h of central retinal artery occlusion in French stroke units. Methods We performed a retrospective analysis of patients treated with intravenous alteplase (recombinant tissue-plasminogen activator), based on stroke units thrombolysis registers from June 2005 to June 2015, and we selected those who had acute central retinal artery occlusion. The feasibility was assessed by the ratio of patients that had received intravenous alteplase within 6 h after central retinal artery occlusion onset among those who had been admitted to the same hospital for acute central retinal artery occlusion. All adverse events were documented. Results Thirty patients were included. Visual acuity before treatment was limited to "hand motion", or worse, in 90% of the cases. The mean onset-to-needle time was 273 min. The individuals treated with intravenous alteplase for central retinal artery occlusion represented 10.2% of all of the patients hospitalized for central retinal artery occlusion in 2013 and 2014. We observed one occurrence of major bleeding, a symptomatic intracerebral hemorrhage. Conclusion When applied early on, intravenous thrombolysis appears to be feasible and safe, provided that contraindications are given due consideration. Whether intravenous thrombolysis is more effective than conservative therapy remains to be determined. In order to conduct a well-designed prospective randomized control trial, an organized network should be in place.

  7. Accuracy of using serum D-dimer for diagnosis of acute intestinal ischemia

    PubMed Central

    Sun, Da-Li; Li, Shu-Min; Cen, Yun-Yun; Xu, Qing-Wen; Li, Yi-Jun; Sun, Yan-Bo; Qi, Yu-xing; Lin, Yue-Ying; Yang, Ting; An, Li-Ya; Su, Kun; Li, Wei-Ming; Xu, Peng-Yuan

    2017-01-01

    Abstract Objective: The purpose of this meta-analysis is to comprehensively assess the accuracy of serum D-dimer for the diagnosis of acute intestinal ischemia. Methods: Diagnostic studies of D-dimer for accurate diagnosis of acute intestinal ischemia were extracted from 6 databases, and prospective and retrospective studies that provided adequate data on sensitivity and specificity were included here. Sensitivity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were calculated. The overall diagnostic performance of D-dimer was assessed by plotting a summary receiver operating characteristic curve (SROC) and calculating the area under the curve (AUC). Results: A total of 1300 patients with suspected acute intestinal ischemia from 12 studies met the inclusion criteria. The combined sensitivity, specificity, PLR, NLR, and DOR were 0.94 (95% CI: 0.87–0.97), 0.50 (95% CI: 0.40–0.61), 1.9 (95% CI: 1.5–2.3), 0.12 (95% CI: 0.05–0.26), and 16 (95% CI: 7–39), respectively. The AUC was 0.81 (95% CI: 0.78–0.84). Conclusion: The results of this meta-analysis suggested that plasma D-dimer detection might be a useful means of identifying patients with acute intestinal ischemia of the abdomen. PMID:28353564

  8. Investigation of ischemia modified albumin, oxidant and antioxidant markers in acute myocardial infarction

    PubMed Central

    Hazini, Ahmet; Işıldak, İbrahim; Alpdağtaş, Saadet; Önül, Abdullah; Şenel, Ünal; Kocaman, Tuba; Dur, Ali; Iraz, Mustafa; Uyarel, Hüseyin

    2015-01-01

    Introduction Acute myocardial infarction (AMI) is still one of the most common causes of death worldwide. In recent years, for diagnosis of myocardial ischemia, a new parameter, called ischemia modified albumin (IMA), which is thought to be more advantageous than common methods, has been researched. Aim In this study, systematic analysis of parameters considered to be related to myocardial ischemia has been performed, comparing between control and myocardial ischemia groups. Material and methods We selected 40 patients with AMI and 25 healthy controls for this study. Ischemia modified albumin levels, glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) antioxidant enzyme activities and non-enzymatic antioxidants such as retinol, α-tocopherol, β-carotene and ascorbic acid levels were investigated in both groups. Glutathione (GSH) and malondialdehyde (MDA) levels, which are indicators of oxidative stress, were compared between patient and control groups. Results Ischemia modified albumin levels were found significantly higher in the AMI diagnosed group when compared with controls. The MDA level was elevated in the patient group, whereas the GSH level was decreased. SOD, GPx and CAT enzyme levels were decreased in the patient group, where it could be presumed that oxidative stress causes the cardiovascular diseases. Conclusions Due to the increased oxidative stress, non-enzymatic and enzymatic antioxidant capacity was affected. Systematic investigation of parameters related to myocardial infarction has been performed, and it is believed that such parameters can contribute to protection and early diagnosis of AMI and understanding the mechanism of development of the disease. PMID:26677379

  9. Xenon protects left ventricular diastolic function during acute ischemia, less than ischemic preconditioning

    PubMed Central

    Baumert, Jan-H.; Roehl, Anna B.; Funcke, Sandra; Hein, Marc

    2016-01-01

    Anesthetics modify regional left ventricular (LV) dysfunction following ischemia/reperfusion but their effects on global function in this setting are less clear. Aim of this study was to test the hypothesis that xenon would limit global LV dysfunction as caused by acute anterior wall ischemia, comparable to ischemic preconditioning. In an open-chest model under thiopental anesthesia, 30 pigs underwent 60-minute left anterior descending coronary artery occlusion, followed by 120 minutes of reperfusion. A xenon group (constant inhalation from previous to ischemia through end of reperfusion) was compared to control and ischemic preconditioning. Load-independent measures of diastolic function (end-diastolic pressure-volume relation, time constant of relaxation) and systolic function (end-systolic pressure-volume relation, preload-recruitable stroke work) were determined. Heart rate, arterial pressure, cardiac output, and arterial elastance were recorded. Data were compared in 26 pigs. Ischemia impaired global diastolic but not systolic function in control, which recovered during reperfusion. Xenon limited and preconditioning abolished diastolic dysfunction during ischemia. Arterial pressure decreased during reperfusion while arterial elastance increased. Tachycardia and antero-septal wall edema during reperfusion were observed in all groups. In spite of ischemia of 40% of LV mass, global systolic function was preserved. Deterioration in global diastolic function was limited by xenon and prevented by preconditioning. PMID:27867480

  10. Depressive Symptoms Are Associated with Mental Stress-Induced Myocardial Ischemia after Acute Myocardial Infarction

    PubMed Central

    Wei, Jingkai; Pimple, Pratik; Shah, Amit J.; Rooks, Cherie; Bremner, J. Douglas; Nye, Jonathon A.; Ibeanu, Ijeoma; Murrah, Nancy; Shallenberger, Lucy; Raggi, Paolo; Vaccarino, Viola

    2014-01-01

    Objectives Depression is an adverse prognostic factor after an acute myocardial infarction (MI), and an increased propensity toward emotionally-driven myocardial ischemia may play a role. We aimed to examine the association between depressive symptoms and mental stress-induced myocardial ischemia in young survivors of an MI. Methods We studied 98 patients (49 women and 49 men) age 38–60 years who were hospitalized for acute MI in the previous 6 months. Patients underwent myocardial perfusion imaging at rest, after mental stress (speech task), and after exercise or pharmacological stress. A summed difference score (SDS), obtained with observer-independent software, was used to quantify myocardial ischemia under both stress conditions. The Beck Depression Inventory-II (BDI-II) was used to measure depressive symptoms, which were analyzed as overall score, and as separate somatic and cognitive depressive symptom scores. Results There was a significant positive association between depressive symptoms and SDS with mental stress, denoting more ischemia. After adjustment for demographic and lifestyle factors, disease severity and medications, each incremental depressive symptom was associated with 0.14 points higher SDS. When somatic and cognitive depressive symptoms were examined separately, both somatic [β = 0.17, 95% CI: (0.04, 0.30), p = 0.01] and cognitive symptoms [β = 0.31, 95% CI: (0.07, 0.56), p = 0.01] were significantly associated with mental stress-induced ischemia. Depressive symptoms were not associated with ischemia induced by exercise or pharmacological stress. Conclusion Among young post-MI patients, higher levels of both cognitive and somatic depressive symptoms are associated with a higher propensity to develop myocardial ischemia with mental stress, but not with physical (exercise or pharmacological) stress. PMID:25061993

  11. Regional Myocardial Blood Flow and Ultrastructure Following Acute Temporary Ischemia.

    DTIC Science & Technology

    1982-01-01

    kidneys of dogs and cats , and suggest some element present in whole blood, but not present in filtered blood may serve to further damage ischemic...minutes of myocardial ischemia in the dog as Krug et al. (66) has reported in the cat . Finally, in this experiment the relationship of inhibited reflow...transient inhibition of flow. One has to wonder if their 6 cats with smaller areas of risk are more like the dogs in this study and may also have had

  12. Overexpression of Heme Oxygenase-1 in Mesenchymal Stem Cells Augments Their Protection on Retinal Cells In Vitro and Attenuates Retinal Ischemia/Reperfusion Injury In Vivo against Oxidative Stress

    PubMed Central

    Li, Li; Du, GaiPing; Wang, DaJiang; Zhou, Jin; Jiang, Guomin

    2017-01-01

    Retinal ischemia/reperfusion (I/R) injury, involving several ocular diseases, seriously threatens human ocular health, mainly treated by attenuating I/R-induced oxidative stress. Currently, mesenchymal stem cells (MSCs) could restore I/R-injured retina through paracrine secretion. Additionally, heme oxygenase-1 (HO-1) could ameliorate oxidative stress and thus retinal apoptosis, but the expression of HO-1 in MSC is limited. Here, we hypothesized that overexpression of HO-1 in MSC (MSC-HO-1) may significantly improve their retina-protective potentials. The overexpression of HO-1 in MSC was achieved by lentivirus transduction. Then, MSC or MSC-HO-1 was cocultured with retinal ganglion cells (RGC-5) in H2O2-simulated oxidative condition and their protection on RGC-5 was systemically valuated in vitro. Compared with MSC, MSC-HO-1 significantly attenuated H2O2-induced injury of RGC-5, including decrease in cellular ROS level and apoptosis, activation of antiapoptotic proteins p-Akt and Bcl-2, and blockage of proapoptotic proteins cleaved caspase 3 and Bax. In retinal I/R rats model, compared with control MSC, MSC-HO-1-treated retina significantly retrieved its structural thickness, reduced cell apoptosis, markedly attenuated retinal oxidative stress level, and largely regained the activities of typical antioxidant enzymes, SOD and CAT. Therefore, it could be concluded that overexpression of HO-1 provides a promising strategy to enhance the MSC-based therapy for I/R-related retinal injury. PMID:28255307

  13. Obestatin Accelerates the Recovery in the Course of Ischemia/Reperfusion-Induced Acute Pancreatitis in Rats

    PubMed Central

    Bukowczan, Jakub; Warzecha, Zygmunt; Ceranowicz, Piotr; Kuśnierz-Cabala, Beata; Tomaszewska, Romana

    2015-01-01

    Objective Several previous studies have shown that obestatin exhibits protective and regenerative effects in some organs including the stomach, kidney, and the brain. In the pancreas, pretreatment with obestatin inhibits the development of cerulein-induced acute pancreatitis, and promotes survival of pancreatic beta cells and human islets. However, no studies investigated the effect of obestatin administration following the onset of experimental acute pancreatitis. Aim The aim of this study was to evaluate the impact of obestatin therapy in the course of ischemia/reperfusion-induced pancreatitis. Moreover, we tested the influence of ischemia/reperfusion-induced acute pancreatitis and administration of obestatin on daily food intake and pancreatic exocrine secretion. Methods Acute pancreatitis was induced by pancreatic ischemia followed by reperfusion of the pancreas. Obestatin (8nmol/kg/dose) was administered intraperitoneally twice a day, starting 24 hours after the beginning of reperfusion. The effect of obestatin in the course of necrotizing pancreatitis was assessed between 2 and 14 days, and included histological, functional, and biochemical analyses. Secretory studies were performed on the third day after sham-operation or induction of acute pancreatitis in conscious rats equipped with chronic pancreatic fistula. Results Treatment with obestatin ameliorated morphological signs of pancreatic damage including edema, vacuolization of acinar cells, hemorrhages, acinar necrosis, and leukocyte infiltration of the gland, and led to earlier pancreatic regeneration. Structural changes were accompanied by biochemical and functional improvements manifested by accelerated normalization of interleukin-1β level and activity of myeloperoxidase and lipase, attenuation of the decrease in pancreatic DNA synthesis, and by an improvement of pancreatic blood flow. Induction of acute pancreatitis by pancreatic ischemia followed by reperfusion significantly decreased daily food

  14. Acute Retinal Necrosis Presenting in Developmentally-delayed Patients with Neonatal Encephalitis: A Case Series and Literature Review.

    PubMed

    Okafor, Kingsley; Lu, Jonathan; Thinda, Sumeer; Schwab, Ivan; Morse, Lawrence S; Park, Susanna S; Moshiri, Ala

    2016-05-18

    We report three cases of patients with developmental-delay from neonatal herpetic encephalitis and/or meningitis who presented years later with acute retinal necrosis due to herpes simplex virus. The diagnosis was delayed in all cases due to the patients' inability to verbalize their ocular complaints and cooperate with eye examinations. This case series documents the clinical course, pathophysiologic mechanism, and treatment of acute retinal necrosis in this patient population. Clinicians should understand the importance of prudent consideration of acute retinal necrosis in patients with a history of neonatal herpetic encephalitis and/or meningitis presenting with a red eye.

  15. Unilateral Renal Ischemia as a Model of Acute Kidney Injury and Renal Fibrosis in Cats.

    PubMed

    Schmiedt, C W; Brainard, B M; Hinson, W; Brown, S A; Brown, C A

    2016-01-01

    The objectives of this study were to define the acute and chronic effects of 1-hour unilateral in vivo renal ischemia on renal function and histology in cats. Twenty-one adult purpose-bred research cats were anesthetized, and 1 kidney underwent renal artery and vein occlusion for 1 hour. Serum creatinine and urea concentrations, urine protein:creatinine ratio, urine-specific gravity, glomerular filtration rate, hematocrit, platelet concentration and function, and white blood cell count were measured at baseline and variable time points after ischemia. Renal histopathology was evaluated on days 3, 6, 12, 21, 42, and 70 postischemia; changes in smooth muscle actin and interstitial collagen were examined. Following ischemia, whole animal glomerular filtration rate was significantly reduced (57% of baseline on day 6; P < .05). At the early time points, the ischemic kidneys exhibited severe acute epithelial necrosis accompanied by evidence of regeneration of tubules predominantly within the corticomedullary junction. At later periods, postischemic kidneys had evidence of tubular atrophy and interstitial inflammation with significantly more smooth muscle actin and interstitial collagen staining and interstitial fibrosis when compared with the contralateral control kidneys. This study characterizes the course of ischemic acute kidney injury in cats and demonstrates that ischemic acute kidney injury triggers chronic fibrosis, interstitial inflammation, and tubular atrophy in feline kidneys. These late changes are typical of those observed in cats with naturally occurring chronic kidney disease.

  16. Role of ischemia in acute pancreatitis. Hemorrhagic shock converts edematous pancreatitis to hemorrhagic pancreatitis in rats.

    PubMed

    Kyogoku, T; Manabe, T; Tobe, T

    1992-09-01

    Ischemia has been considered to play a role in the development of acute pancreatitis. The aim of this study was to investigate the effect of ischemia, caused by hemorrhagic shock, on cerulein-induced acute pancreatitis in rats. Acute pancreatitis was induced by the intravenous infusion of a supramaximally stimulating dose of cerulein (10 micrograms/kg/hr) for 6 hr. Hemorrhagic shock was induced by the removal of blood until the mean arterial blood pressure reached 35 mm Hg. This level was maintained for 30 min, after which time all the blood was reinfused. Hemorrhagic shock alone induced no morphological change in the pancreas. However, after the induction of hemorrhagic shock in animals treated with cerulein, hemorrhage and parenchymal necrosis were frequently observed in the pancreas. Seven of 20 rats (35%) receiving cerulein plus hemorrhagic shock had died by 48 hr after the start of cerulein infusion, whereas none of the rats in the cerulein or shock group died during this experiment. Cathepsin B activity in the pancreas of the cerulein plus shock group was significantly higher than in the other groups at 48 hr. These results suggest that ischemia may be a contributing factor in the pathogenesis of acute pancreatitis.

  17. Mechanisms Underlying Acute Protection from Cardiac Ischemia-Reperfusion Injury

    PubMed Central

    Murphy, Elizabeth; Steenbergen, Charles

    2009-01-01

    Mitochondria play an important role in cell death and cardioprotection. During ischemia, when ATP is progressively deleted, ion pumps cannot function resulting in a rise in calcium (Ca2+), which further accelerates ATP depletion. The rise in Ca2+ during ischemia and reperfusion leads to mitochondrial Ca2+ accumulation, particularly during reperfusion when oxygen is reintroduced. Reintroduction of oxygen allows generation of ATP; however damage to electron transport chain results in increased mitochondrial generation of reactive oxygen species (ROS). Mitochondrial Ca2+ overload, and increased ROS can result in opening of the mitochondrial permeability transition pore, which further compromises cellular energetics. The resultant low ATP and altered ion homeostasis result in rupture of the plasma membrane and cell death. Mitochondria have long been proposed as central players in cell death, since the mitochondria are central to synthesis of both ATP and ROS and since mitochondrial and cytosolic Ca2+ overload are key components of cell death. Many cardioprotective mechanisms converge on the mitochondria to reduce cell death. Reducing Ca2+ overload and reducing ROS have both been reported to reduce ischemic injury. Preconditioning activates a number of signaling pathways that reduce Ca2+ overload and reduce activation of the mitochondrial permeability transition pore. The mitochondrial targets of cardioprotective signals will be discussed in detail. PMID:18391174

  18. Effect of Cuscuta chinensis on renal function in ischemia/reperfusion-induced acute renal failure rats.

    PubMed

    Shin, Sun; Lee, Yun Jung; Kim, Eun Ju; Lee, An Sook; Kang, Dae Gill; Lee, Ho Sub

    2011-01-01

    The kidneys play a central role in regulating water, ion composition and excretion of metabolic waste products in the urine. Cuscuta chinensis has been known as an important traditional Oriental medicine for the treatment of liver and kidney disorders. Thus, we studied whether an aqueous extract of Cuscuta chinensis (ACC) seeds has an effect on renal function parameters in ischemia/reperfusion-induced acute renal failure (ARF) rats. Administration of 250 mg/kg/day ACC showed that renal functional parameters including urinary excretion rate, osmolality, Na(+), K(+), Cl(-), creatinine clearance, solute-free water reabsorption were significantly recovered in ischemia/reperfusion-induced ARF. Periodic acid Schiff staining showed that administration of ACC improved tubular damage in ischemia/reperfusion-induced ARF. In immunoblot and immunohistological examinations, ischemia/reperfusion-induced ARF decreased the expressions of water channel AQP 2, 3 and sodium potassium pump Na,K-ATPase in the renal medulla. However, administration of ACC markedly incremented AQP 2, 3 and Na,K-ATPase expressions. Therefore, these data indicate that administration of ACC ameliorates regulation of the urine concentration and renal functions in rats with ischemia/reperfusion-induced ARF.

  19. Analysis of temporal dynamics in imagery during acute limb ischemia and reperfusion

    NASA Astrophysics Data System (ADS)

    Irvine, John M.; Regan, John; Spain, Tammy A.; Caruso, Joseph D.; Rodriquez, Maricela; Luthra, Rajiv; Forsberg, Jonathon; Crane, Nicole J.; Elster, Eric

    2014-03-01

    Ischemia and reperfusion injuries present major challenges for both military and civilian medicine. Improved methods for assessing the effects and predicting outcome could guide treatment decisions. Specific issues related to ischemia and reperfusion injury can include complications arising from tourniquet use, such as microvascular leakage in the limb, loss of muscle strength and systemic failures leading to hypotension and cardiac failure. Better methods for assessing the viability of limbs/tissues during ischemia and reducing complications arising from reperfusion are critical to improving clinical outcomes for at-risk patients. The purpose of this research is to develop and assess possible prediction models of outcome for acute limb ischemia using a pre-clinical model. Our model relies only on non-invasive imaging data acquired from an animal study. Outcome is measured by pathology and functional scores. We explore color, texture, and temporal features derived from both color and thermal motion imagery acquired during ischemia and reperfusion. The imagery features form the explanatory variables in a model for predicting outcome. Comparing model performance to outcome prediction based on direct observation of blood chemistry, blood gas, urinalysis, and physiological measurements provides a reference standard. Initial results show excellent performance for the imagery-base model, compared to predictions based direct measurements. This paper will present the models and supporting analysis, followed by recommendations for future investigations.

  20. Classical and remote post-conditioning effects on ischemia/reperfusion-induced acute oxidant kidney injury.

    PubMed

    Kadkhodaee, Mehri; Najafi, Atefeh; Seifi, Behjat

    2014-11-01

    The present study aimed to analyze and compare the effects of classical and remote ischemic postconditioning (POC) on rat renal ischemia/reperfusion (IR)-induced acute kidney injury. After right nephrectomy, male rats were randomly assigned into four groups (n = 8). In the IR group, 45 min of left renal artery occlusion was induced followed by 24 h of reperfusion. In the classical POC group, after induction of 45 min ischemia, 4 cycles of 10 s of intermittent ischemia and reperfusion were applied to the kidney before complete restoring of renal blood. In the remote POC group, 4 cycles of 5 min ischemia and reperfusion of left femoral artery were applied after 45 min renal ischemia and right at the time of renal reperfusion. There was a reduction in renal function (increase in blood urea and creatinine) in the IR group. Application of both forms of POC prevented the IR-induced reduction in renal function and histology. There were also significant improvements in kidney oxidative stress status in both POC groups demonstrated by a reduction in malondialdehyde (MDA) formation and preservation of antioxidant levels comparing to the IR group. We concluded that both methods of POC have protective effects on renal function and histology possibly by a reduction in IR-induced oxidative stress.

  1. Value of the CT "capsular sign" as a potential indicator of acute adrenal ischemia.

    PubMed

    Moschetta, Marco; Telegrafo, Michele; Pignatelli, Armando; Stabile Ianora, Amato Antonio; Angelelli, Giuseppe

    2015-10-01

    Acute adrenal ischemia represents a rare cause of adrenal insufficiency which should be promptly diagnosed in order to preserve adrenal vitality and function. Our study aims to retrospectively evaluate the diagnostic accuracy of the CT capsular sign as an indicator of adrenal ischemia and its association with vascular involvement. Between January 2013 and January 2014, 69 consecutive patients (47 men, 22 women; mean age 46; range 22-67) with suspected adrenal insufficiency based on clinical and biochemical data underwent 320-row CT examination in our Emergency Department. Written informed consent was obtained for the CT examinations, and the institutional review board approval was obtained for our retrospective study. CT multi-planar images were retrospectively and independently analyzed by two radiologists searching for the patency of adrenal vessels, enlarged adrenals, the presence of the "capsular sign" represented by a peripheral subtle hyperdense line around a hypodense enlarged adrenal, and the presence of any periadrenal inflammatory changes. All CT findings were then compared with the surgical findings (n = 5), follow-up examinations (n = 20), or autopsy (n = 4). Sensitivity, specificity, diagnostic accuracy (DA), positive predictive value (PPV), and negative predictive value (NPV) were calculated for the "capsular sign" and were further evaluated by ROC analysis. Acute adrenal ischemia occurred in 29/69 patients (42 %), unilateral in 20, and bilateral in 9. Forty of sixty-nine patients (58 %) had no evidence of adrenal disease on CT. Thrombosis of the main adrenal vein was found in 20/29 (69 %) and non-venous ischemia in 9/29 (31 %). The capsular sign was found in 24/29 patients (83 %). Sensitivity, specificity, DA, PPV, and NPV values of 83, 100, 93, 100, and 89 %, respectively, were obtained. The capsular sign represents a CT indicator of acute adrenal ischemia, with a specificity of 100 % and leading to a prompt diagnosis in the early

  2. Aortic dissection presenting as acute lower extremity ischemia: report of a case.

    PubMed Central

    Liu, Wen-Pin; Chen, Wei-Kung; Ng, Kim-Choy

    2002-01-01

    Although not common, acute leg ischemia is an important element in the clinical presentation of a patient with aortic dissection. This report describes a case of aortic dissection in which the main feature at presentation was acute right leg ischemia. The angiography showed right common iliac artery and external iliac artery occlusion. Diagnosis was made by clinical evaluation and angiography. Embolectomy was then attempted immediately but failed. Aortic dissection was highly suspected and confirmed by emergency computed tomography. Fortunately, the patient had good recovery. Aortic dissection is potentially lethal if misdiagnosed or if recognition is delayed. As such, aortic dissection should be considered in the differential diagnosis. Images Figure 1 Figure 2 PMID:12784971

  3. The analysis of limbs acute ischemia during seasons on the territory of South Serbia.

    PubMed

    Damnjanović, Zoran; Jovanović, Milan; Janković, Irena; Cvetanović, Vladan; Smiljković, Igor; Janković, Dimitrije

    2013-02-01

    The aim of this study was to examine the seasons variations in incidence of limbs acute ischemia (LAI) as well as the connection between seasons with location of LAI, old age and gender. During the three year period between January 2009 and December 2011, at the Clinic for Vascular Surgery, Clinical Center of Nis, Serbia, 167 patients were hospitalized diagnosed with limbs acute ischemia. There was no statistically significant difference in patients distribution with LAI compared with seasons (p=0.726) and months of the year (p=0.0741). There was no statistically significant difference in patients age (p=0.066), sex (p=0.923) and LAI localization (p=0.219 ) in different seasons. The absence of seasonal and monthly patterns for the AIE creation as well as its localization is followed by the absence of a connection between the age and the sex..

  4. [Acute cerebral ischemia: an unusual clinical presentation of isolated left ventricular noncompaction in an adult patient].

    PubMed

    Fiorencis, Andrea; Quadretti, Laura; Bacich, Daniela; Chiodi, Elisabetta; Mele, Donato; Fiorencis, Roberto

    2013-01-01

    Isolated left ventricular noncompaction in adults is uncommon. The most frequent clinical manifestations are heart failure due to left ventricular systolic dysfunction and supraventricular and ventricular arrhythmias, which may be sustained and associated with sudden death. Thromboembolic complications are also possible. We report the case of an adult patient with isolated left ventricular noncompaction who came to our observation because of acute cerebral ischemia, an initial presentation of the disease only rarely described.

  5. The pros and cons of endovascular and open surgical treatments for patients with acute limb ischemia.

    PubMed

    Branco, B C; Montero-Baker, M F; Mills, J L

    2015-06-01

    The present review addresses the pros and cons of the current, wide variety of therapeutic options available for the treatment of acute limb ischemia (ALI). Despite five prospective randomized controlled trials comparing catheter directed thrombolysis and open surgical revascularization, no single treatment strategy can yet be considered optimal for patients with ALI. This report includes 20 years of published data to evaluate the efficacy and safety profile of thrombolytic agents and adjunctive endovascular techniques when compared to open surgical revascularization.

  6. Type B Dissection Resulting in Acute Limb Ischemia in a Patient With a History of EVAR.

    PubMed

    Jayakumar, Lalithapriya; Lombardi, Joseph V; Caputo, Francis J

    2017-02-01

    Type B aortic dissection (TBAD) can be complicated due to visceral and limb malperfusion. We present the case of a patient with a TBAD 5 months after endovascular aneurysm repair (EVAR) for an infrarenal aortic aneurysm, which resulted in a right leg acute limb ischemia due to impingement of the EVAR from to the dissection. In the following discussion, we will review the literature and describe our technique for the treatment of this infrequent problem.

  7. Protective effect of alpha-melanocyte-stimulating hormone (α-MSH) on the recovery of ischemia/reperfusion (I/R)-induced retinal damage in a rat model.

    PubMed

    Varga, Balazs; Gesztelyi, Rudolf; Bombicz, Mariann; Haines, David; Szabo, Adrienn Monika; Kemeny-Beke, Adam; Antal, Miklos; Vecsernyes, Miklos; Juhasz, Bela; Tosaki, Arpad

    2013-07-01

    The present study demonstrates capacity of α-MSH to augment recovery from ischemia/reperfusion (I/R)-induced retinal damage in vivo and correlation of its protective effects with expression of heme oxygenase-1 (HO-1). Used techniques include ocular ischemia and reperfusion, electroretinography, histology, electron microscopy, and molecular-biological techniques. The results demonstrate the α-MSH-mediated inhibition of I/R-induced functional deterioration of the retina. Outcomes suggest that the protective effects of α-MSH occur mainly through HO-1-dependent pathways but HO-1-independent mechanisms may also contribute to protection. The observation that post-ischemic treatment with α-MSH exhibits therapeutic efficacy in the same range as pre-ischemic treatment, is a novel result. This outcome suggests a highly conserved protective role for α-MSH as a major stress response mechanism--and offers the possibility for development of novel therapeutic strategies utilizing this hormone, in particular in treatment of conditions resulting from I/R injury, such as deterioration of retinal microcirculation. The merit of the study lies in the fact that I/R injury contribute significantly to the severity of retinopathies. However, currently there are no evidence-based treatments for retinal I/R injury available for clinical use. Our finding suggests that α-MSH may have a very wide range of uses in the prevention of I/R-mediated pathologies.

  8. N-acetylcysteine and acute retinal laser lesions in the colubrid snake eye

    NASA Astrophysics Data System (ADS)

    Elliott, William R., III; Rentmeister-Bryant, Heike K.; Barsalou, Norman; Beer, Jeremy; Zwick, Harry

    2004-07-01

    This study examined the role of oxidative stress and the effect of a single dose treatment with N-Acetylcysteine (NAC) on the temporal development of acute laser-induced retinal injury. We used the snake eye/Scanning Laser Ophthalmoscope (SLO) model, an in vivo, non-invasive ocular imaging technique, which has the ability to image cellular retinal detail and allows for studying morphological changes of retinal injury over time. For this study 12 corn-snakes (Elaphe g. guttata) received 5 laser exposures per eye, followed by either a single dose of the antioxidant NAC (150mg/kg, IP in sterile saline) or placebo. Laser exposures were made with a Nd: VO4 DPSS, 532nm laser, coaxially aligned to the SLO. Shuttered pulses were 20msec x 50 mW; 1mJ each. Retinal images were taken using a Rodenstock cSLO and were digitally recorded at 1, 6, 24-hrs, and at 3-wks post-exposure. Lesions were assessed by two raters blind to the conditions of the study yielding measures of damaged area and counts of missing or damaged photoreceptors. Treated eyes showed a significant beneficial effect overall, and these results suggest that oxidative stress plays a role in laser-induced retinal injury. The use of NAC or a similar antioxidant shows promise as a therapeutic tool.

  9. [Electrone probe microanalysis of rubidium retention in myocell of rat heart during acute ischemia].

    PubMed

    Pogorelov, A G; Pogorelova, V N; Pogorelova, M A

    2012-01-01

    In the given investigation contents of potassium and its physiological analog, rubidium, are determined in cardiomyocyte. Applying Electron Probe Microanalysis (EPMA), cytoplasmic concentrations of elements (K, Rb) are measured. The data obtained exhibit that for initial acute ischemia phase the active transport is involved in the uptake of rubidium which competes with potassium entry in cardiac myocell. Then, deep deenergization leads to the intracellular potassium depletion and rubidium retention. This suggests that Rb+ is physiologically not complete analog for K+. Results of combined perfusion with and without rubidium allow us to hypothesize the appearance of cascade of ionic transports to compensate acute ischemic disturbances following the oxygen and substrate deficiency.

  10. [Cardioprotective effect of drugs with antioxidant activity in acute cerebral ischemia].

    PubMed

    Stoliarova, V V

    2001-01-01

    The bioelectric cardiac activity was studied in the experiments on white mice with an acute cerebral blood circulation disorder. It was found that he resulting EEG changes possess a specific character, with the sympathoadrenal system stimulation playing an important role in the acute cerebrocardiac syndrome development. The antioxidant-type agents such as emoxypine (50 mg/kg), mexidol (50 mg/kg), and cytochrome C (10 mg/kg) produce a significant cardioprotective effect in the test animals with experimental cerebral ischemia, which was comparable with the effect of propranolol (obsidane) (0.1 mg/kg).

  11. Oxygen or cooling, to make a decision after acute ischemia stroke

    PubMed Central

    Liu, Wen-cao; Jin, Xin-chun

    2016-01-01

    The presence of a salvageable penumbra, a region of ischemic brain tissue with sufficient energy for short-term survival, has been widely agreed as the premise for thrombolytic therapy with tissue plasminogen activator (tPA), which remains the only United States Food and Drug Administration (FDA) approved treatment for acute ischemia stroke. However, the use of tPA has been profoundly constrained due to its narrow therapeutic time window and the increased risk of potentially deadly hemorrhagic transformation (HT). Blood brain barrier (BBB) damage within the thrombolytic time window is an indicator for tPA-induced HT and both normobaric hyperoxia (NBO) and hypothermia have been shown to protect the BBB from ischemia/reperfusion injury. Therefore, providing the O2 as soon as possible (NBO treatment), freezing the brain (hypothermia treatment) to slow down ischemia-induced BBB damage or their combined use may extend the time window for the treatment of tPA. In this review, we summarize the protective effects of NBO, hypothermia or their use combined with tPA on ischemia stroke, based on which, the combination of NBO and hypothermia may be an ideal early stroke treatment to preserve the ischemic penumbra. Given this, there is an urge for large randomized controlled trials to address the effect. PMID:28217292

  12. Effects of electrical heterogeneity on transmural reentry during acute global ischemia.

    PubMed

    Zhang, Hong; Jin, Yin-Bin; Zhang, Zhen-Xi; Yang, Lin; Huang, Ye-Cho

    2010-03-01

    Ventricular arrhythmias are commonly observed in patients with ischemia. It is reported that the electrophysiological changes evoked by ischemia are greater in the epicardium than in the endocardium. To investigate the effects of this heterogeneity on transmural reentry, the computer simulation method is used. A two-dimensional model which can reproduce the endocardial, epicardial and middle cell types, approximate the ischemic characteristics and distribution of the ischemic severity is developed by setting different ratios of the maximum conductance of the rapid and slow inward rectifier potassium currents and considering the three major component conditions of acute ischemia at the ionic level. The results demonstrate that action potentials of the ischemic cells have elevated resting potential, shortened duration, slowed upstroke and declined amplitude. Conduction velocity is much more depressed in the epicardium because of the ischemia-induced transmural gradient of excitability. The epicardially initiated activation has wider vulnerable window and more possibility to cause unidirectional propagation even reentry. Dispersion of the excitability is proposed to be the underlying mechanism.

  13. A serial study of retinal changes following optic neuritis with sample size estimates for acute neuroprotection trials.

    PubMed

    Henderson, Andrew P D; Altmann, Daniel R; Trip, Anand S; Kallis, Constantinos; Jones, Steve J; Schlottmann, Patricio G; Garway-Heath, David F; Plant, Gordon T; Miller, David H

    2010-09-01

    Following an episode of optic neuritis, thinning of the retinal nerve fibre layer, which indicates axonal loss, is observed using optical coherence tomography. The longitudinal course of the retinal changes has not been well characterized. We performed a serial optical coherence tomography study in patients presenting with optic neuritis in order to define the temporal evolution of retinal nerve fibre layer changes and to estimate sample sizes for proof-of-concept trials of neuroprotection using retinal nerve fibre layer loss as the outcome measure. Twenty-three patients (7 male, 16 female, mean age 31 years) with acute clinically isolated unilateral optic neuritis were recruited to undergo optical coherence tomography, visual assessments and visual evoked potentials at presentation (median 16 days from onset of visual loss) and after 3, 6, 12 and 18 months. Compared with the clinically unaffected fellow eye, the retinal nerve fibre layer thickness of the affected eye was significantly increased at presentation and significantly reduced at all later time points. The evolution of retinal nerve fibre layer changes in the affected eye fitted well with an exponential model, with thinning appearing a mean of 1.6 months from symptom onset and the rate of ongoing retinal nerve fibre layer loss decreasing thereafter. At presentation, increased retinal nerve fibre layer thickness was associated with impaired visual acuity and prolonged visual evoked potential latency. Visual function after 12 months was not related to the extent of acute retinal nerve fibre layer swelling but was significantly associated with the extent of concurrent retinal nerve fibre layer loss. Sample size calculations for placebo-controlled trials of acute neuroprotection indicated that the numbers needed after 6 months of follow up are smaller than those after 3 months and similar to those after 12 months of follow-up. Study power was greater when investigating differences between clinically

  14. Mechanistic investigation of extracellular K+ accumulation during acute myocardial ischemia: a simulation study.

    PubMed

    Rodríguez, B; Ferrero, J M; Trénor, B

    2002-08-01

    In this study, we have used computer simulations to study the mechanisms of extracellular K+ accumulation during acute ischemia. A modified version of the Luo-Rudy phase II action potential model was used to simulate the electrical behavior of one ventricular myocyte during 14 min of simulated ischemia. Our results show the following: 1) only the integrated effect of activation of ATP-dependent K+ current, an ischemic Na+ inward current, and inhibition of Na(+)-K(+) pump activity in the absence of coronary flow replicates the biphasic time course of extracellular K+ concentration observed during acute ischemia; 2) the time to onset of the plateau phase and the plateau level value are determined by the rate of stimulation and by the rate of alteration of the three mechanisms. However, acidosis and reduction of extracellular volume produce only a slight anticipation of the plateau phase; and 3) cellular K+ loss is mainly due to an increase of K+ efflux via the time-independent K+ current and ATP-dependent K+ current rather than to a decrease of K+ influx.

  15. [Cardiovascular adaptability to acute hypercalcemia in the dog. The role of peroperative myocardial ischemia].

    PubMed

    Dumont, L; Stanley, P; Chartrand, C

    1985-01-01

    Since the hemodynamic consequences of acute hypercalcemia are altered by numerous interferences we have evaluated the role of peroperative myocardial ischemia on the adaptability to rapid calcium increment. Twenty-two dogs served as control and 16 were submitted to 1 hour of myocardial ischemia along with topical myocardial cooling. Each animal was equipped with blood flow transducer positioned around the ascending aorta and with central venous and aortic catheters. During each study 0.90 mEq of calcium was rapidly injected and hemodynamic data were recorded until base-line resetting. This experimental protocol was carried out 3 hours postoperatively and then daily during one month. Base-line hemodynamic data indicated the presence of myocardial failure in the experimental group in the immediate postoperative period only. Rapid calcium administration elicited transient positive inotropic response, widening of the arterial pulse pressure, reflex bradycardia and no evidence of peripheral vasoconstriction. In the early postoperative period (3 hours after surgery) the failing myocardium is more sensitive to the inotropic effect of hypercalcemia. Twenty-four hours after surgery both groups of animals have the same hemodynamic response to this stress; thereafter for both groups this response gradually decreased and finally stabilized by the 6th to 10th day after surgery. Acute hypercalcemia bears hemodynamic consequences that are amplified early after peroperative myocardial ischemia. However in long term this surgical component widely used clinically does not interfered with the cardiovascular adaptability to this pharmacological stress.

  16. The CORM ALF-186 Mediates Anti-Apoptotic Signaling via an Activation of the p38 MAPK after Ischemia and Reperfusion Injury in Retinal Ganglion Cells

    PubMed Central

    Ulbrich, Felix; Kaufmann, Kai B.; Meske, Alexander; Lagrèze, Wolf A.; Augustynik, Michael; Buerkle, Hartmut; Ramao, Carlos C.; Biermann, Julia

    2016-01-01

    Purpose Ischemia and reperfusion injury may induce apoptosis and lead to sustained tissue damage and loss of function, especially in neuronal organs. While carbon monoxide is known to exert protective effects after various harmful events, the mechanism of carbon monoxide releasing molecules in neuronal tissue has not been investigated yet. We hypothesize that the carbon monoxide releasing molecule (CORM) ALF-186, administered after neuronal ischemia-reperfusion injury (IRI), counteracts retinal apoptosis and its involved signaling pathways and consecutively reduces neuronal tissue damage. Methods IRI was performed in rat´s retinae for 1 hour. The water-soluble CORM ALF-186 (10 mg/kg) was administered intravenously via a tail vein after reperfusion. After 24 and 48 hours, retinal tissue was harvested to analyze mRNA and protein expression of Bcl-2, Bax, Caspase-3, ERK1/2, p38 and JNK. Densities of fluorogold pre-labeled retinal ganglion cells (RGC) were analyzed 7 days after IRI. Immunohistochemistry was performed on retinal cross sections. Results ALF-186 significantly reduced IRI mediated loss of RGC. ALF-186 treatment differentially affected mitogen-activated protein kinases (MAPK) phosphorylation: ALF-186 activated p38 and suppressed ERK1/2 phosphorylation, while JNK remained unchanged. Furthermore, ALF-186 treatment affected mitochondrial apoptosis, decreasing pro-apoptotic Bax and Caspase-3-cleavage, but increasing anti-apoptotic Bcl-2. Inhibition of p38-MAPK using SB203580 reduced ALF-186 mediated anti-apoptotic effects. Conclusion In this study, ALF-186 mediated substantial neuroprotection, affecting intracellular apoptotic signaling, mainly via MAPK p38. CORMs may thus represent a promising therapeutic alternative treating neuronal IRI. PMID:27764224

  17. [Effectiveness of various dopamine doses in acute myocardial ischemia complicated by cardiogenic shock (an experimental study)].

    PubMed

    Kipshidze, N N; Korotkov, A A; Marsagishvili, L A; Prigolashvili, T Sh; Bokhua, M R

    1981-06-01

    The effect of various doses of dopamine on the values of cardiac contractile and hemodynamic function under conditions of acute two-hour ischemia complicated by cardiogenic shock was studied in 27 experiments on dogs. In a dose of 5 microgram/kg/min dopamine caused an optimum increase in cardiac productive capacity, reduction of peripheral resistance, adequate increase in coronary circulation and decrease in ST segment depression on the ECG. Infusion of 10 microgram/kg/min dopamine usually caused myocardial hyperfunction with an increase in total peripheral resistance and cardiac performance. Maximum dopamine doses (10 microgram/kg/min and more) were effective in the areactive form of cardiogenic shock. In longterm dopamine infusion it is necessary to establish continuous control over the hemodynamic parameters and the ECG to prevent aggravation of ischemia and for stage-by-stage reduction of the drug concentration and determination of the minimum maintenance dose.

  18. Magnetic Resonance Imaging (MRI) Analysis of Ischemia/Reperfusion in Experimental Acute Renal Injury.

    PubMed

    Pohlmann, Andreas; Arakelyan, Karen; Seeliger, Erdmann; Niendorf, Thoralf

    2016-01-01

    Imbalance between renal oxygen delivery and demand in the first hours after reperfusion is suggested to be decisive in the pathophysiological chain of events leading to ischemia-induced acute kidney injury. Here we describe blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) for continuous monitoring of the deoxyhemoglobin-sensitive MR parameter T 2* in the renal cortex, outer medulla, and inner medulla of rats throughout renal ischemia/reperfusion (I/R). Changes during I/R are benchmarked against the effects of variations in the fraction of inspired oxygen (hypoxia, hyperoxia). This method may be useful for investigating renal blood oxygenation of rats in vivo under various experimental (patho)physiological conditions.

  19. Incidence of acute myocardial infarction in patients with exercise-induced silent myocardial ischemia

    SciTech Connect

    Assey, M.E.; Walters, G.L.; Hendrix, G.H.; Carabello, B.A.; Usher, B.W.; Spann, J.F. Jr.

    1987-03-01

    Fifty-five patients with angiographically proved coronary artery disease (CAD) underwent Bruce protocol exercise stress testing with thallium-201 imaging. Twenty-seven patients (group I) showed myocardial hypoperfusion without angina pectoris during stress, which normalized at rest, and 28 patients (group II) had a similar pattern of reversible myocardial hypoperfusion but also had angina during stress. Patients were followed for at least 30 months. Six patients in group I had an acute myocardial infarction (AMI), 3 of whom died, and only 1 patient in group II had an AMI (p = 0.05), and did not die. Silent myocardial ischemia uncovered during exercise stress thallium testing may predispose to subsequent AMI. The presence of silent myocardial ischemia identified in this manner is of prognostic value, independent of angiographic variables such as extent of CAD and left ventricular ejection fraction.

  20. Acute brain ischemia as a complication of the Ehlers-Danlos syndrome, the case series.

    PubMed

    Pajak, Michal; Majos, Marcin A; Szubert, Wojciech; Stefanczyk, Ludomir; Majos, Agata

    2014-10-01

    Vascular type of Ehlers-Danlos syndrome involves many severe complications leading not only to organ-specific symptoms but often ends in a sudden death. The aim of this paper was to present a diagnostic possibilities and its efficiency rate in patients with vascular complications of Ehlers-Danlos syndrome who suffered from artery dissection resulting in acute brain or limb ischemia. We analysed three patients with diagnosed Ehlers-Danlos syndrome who were referred to radiology department for diagnostic imaging of affected vascular beds, each experienced brain ischemia. The paper also aims at offering some general recommendations for patients suffering from possible complications of type IV Ehlers-Danlos syndrome basing on our own experience and available literature data.

  1. Temporal relationship of serum markers and tissue damage during acute intestinal ischemia/reperfusion

    PubMed Central

    la Garza, Francisco Javier Guzmán-de; Ibarra-Hernández, Juan Manuel; Cordero-Pérez, Paula; Villegas-Quintero, Pablo; Villarreal-Ovalle, Claudia Ivette; Torres-González, Liliana; Oliva-Sosa, Norma Edith; Alarcón-Galván, Gabriela; Fernández-Garza, Nancy Esthela; Muñoz-Espinosa, Linda Elsa; Cámara-Lemarroy, Carlos Rodrigo; Carrillo-Arriaga, José Gerardo

    2013-01-01

    OBJECTIVE: It is essential to identify a serological marker of injury in order to study the pathophysiology of intestinal ischemia reperfusion. In this work, we studied the evolution of several serological markers after intestinal ischemia reperfusion injury in rats. The markers of non-specific cell damage were aspartate aminotransferase, alanine aminotransaminase, and lactic dehydrogenase, the markers of inflammation were tumor necrosis factor alpha, interleukin-6, and interleukin-1 beta, and the markers of intestinal mucosal damage were intestinal fatty acid binding protein and D-lactate. We used Chiús classification to grade the histopathological damage. METHODS: We studied 35 Wistar rats divided into groups according to reperfusion time. The superior mesenteric artery was clamped for 30 minutes, and blood and biopsies were collected at 1, 3, 6, 12, 24, and 48 hours after reperfusion. We plotted the mean ± standard deviation and compared the baseline and maximum values for each marker using Student's t-test. RESULTS: The maximum values of interleukin-1 beta and lactic dehydrogenase were present before the maximal histopathological damage. The maximum tumor necrosis factor alpha and D-lactate expressions coincided with histopathological damage. Alanine aminotransaminase and aspartate aminotransferase had a maximum expression level that increased following the histopathological damage. The maximum expressions of interluken-6 and intestinal fatty acid binding protein were not significantly different from the Sham treated group. CONCLUSION: For the evaluation of injury secondary to acute intestinal ischemia reperfusion with a 30 minute ischemia period, we recommend performing histopathological grading, quantification of D-lactate, which is synthesized by intestinal bacteria and is considered an indicator of mucosal injury, and quantification of tumor necrosis factor alpha as indicators of acute inflammation three hours after reperfusion. PMID:23917671

  2. Acute occlusion of the retinal arteries: current concepts and recent advances in diagnosis and management

    PubMed Central

    Beatty, S; Eong, K

    2000-01-01

    Purpose/Background—Central retinal artery occlusion (CRAO) is usually a blinding event, and is not an infrequent presentation to the accident and emergency (A&E) department. The evidence-base in support of current treatment options is weak. Methods—This paper reviewed the literature germane to the diagnostic, therapeutic and prognostic aspects of retinal arterial occlusive disease. Results—The visual prognosis associated with CRAO remains poor, and current therapeutic practices are of unproven benefit. The non-ophthalmologist in the A&E department should lie the patient flat and give a stat dose of intravenous acetazolamide in an attempt to improve the retinal perfusion pressure. Conclusion—The management of acute occlusion of the central retinal artery has not changed over the past 30 years, although the potential benefits of superselective intra-arterial fibrinolytic therapy warrant evaluation in a randomised controlled trial. The identification of underlying pathology is an essential component of medical care, and all cases should be followed up by an ophthalmologist because of the possibility of ocular rubeosis. PMID:11005400

  3. Acute Retinal Necrosis Associated with Epstein-Barr Virus in a Patient Undergoing Immunosuppressive Therapy

    PubMed Central

    Oe, Chiaki; Hiraoka, Miki; Tanaka, Sachie; Ohguro, Hiroshi

    2016-01-01

    Acute retinal necrosis (ARN) is a rapidly progressive and severe retinitis resulting in a poor visual outcome. Infections caused by herpes viruses such as herpes simplex virus (HSV) types 1 and 2 or the varicella zoster virus (VZV) are known to be implicated in the development of ARN. In the present study, an 80-year-old female with ARN was examined. She had been affected with rheumatoid arthritis and had taken methotrexate for over 10 years. Her right eye showed clinical features of ARN, and her left eye showed mild retinitis. The genomic DNA in the aqueous humor and vitreous fluid from her right eye were analyzed by a comprehensive polymerase chain reaction (PCR) assay to screen infectious pathogens including viruses. The Epstein-Barr virus (EBV) was detected from both specimens, but neither HSV or VZV nor cytomegalovirus was detected. She underwent intraocular surgery following systemic corticosteroid and acyclovir applications. However, although the retinitis of her right eye was extinguished, the final visual outcome was blindness due to optic nerve atrophy. There are few reports indicating that EBV is associated with ARN development. The present findings suggest that EBV alone can be the causative agent of ARN. PMID:27194989

  4. Clinical staging of acute limb ischemia as the basis for choice of revascularization method: when and how to intervene.

    PubMed

    Rutherford, Robert B

    2009-03-01

    In acute lower limb ischemia, there are basically three management options: (1) clot removal by catheter-directed thrombolysis with or without percutaneous mechanical thrombectomy, (2) surgical thromboembolectomy followed by correction of underlying arterial lesions, and (3) anticoagulation with continued observation. Arterial embolic occlusion presents more abruptly and with more severe ischemia than arterial thrombosis, which occurs in narrowed arterial segments that have generally developed some degree of collateral circulation. The appropriate choice of treatment for acute limb ischemia depends to a great extent on the severity of the ischemia. Level of ischemia is readily determined by examining for sensory loss or motor deficit and interrogating the distal arteries and veins for audible flow signals with a handheld Doppler velocity detector. After clot removal, appropriate management of the responsible underlying lesion depends on its characteristics, best determined by vascular imaging. Staging the severity of ischemia according to clinical classification levels in the current reporting standards for lower extremity ischemia continues to serve as the basis for logical management decisions. This approach is outlined in algorithmic form and alternative pathways are discussed in this article.

  5. Quantified kidney echogenicity in mice with renal ischemia reperfusion injury: evaluation as a noninvasive biomarker of acute kidney injury.

    PubMed

    Murata, Shinya; Sugiyama, Noriyuki; Maemura, Kentaro; Otsuki, Yoshinori

    2017-04-05

    The purpose is to evaluate quantified kidney echogenicity as a biomarker for the early diagnosis of acute kidney injury (AKI) and predicting progression to chronic kidney disease (CKD) in a mouse model of ischemia-reperfusion injury (IRI). Two separate protocols of murine models of IRI were used: (1) 10, 30, and 40 min of bilateral ischemia duration and (2) 45 and 60 min of unilateral ischemia duration. Renal echogenicity was measured with ultrasound and compared with serum creatinine or urine neutrophil gelatinase-associated lipocalin (NGAL) at various timepoints after IRI. In mice subjected to 10, 30, and 40 min of bilateral ischemia, renal echogenicity increased about 2 h after IRI for all ischemia times, earlier than serum creatinine or urine NGAL. In those subjected to 45 and 60 min of unilateral ischemia, 60 min of unilateral ischemia, which represents atrophic changes 28 days after IRI, resulted in a sustained high level of echogenicity and was significantly different 24 h after IRI, while 45 min of unilateral ischemia resulted in trivial levels of histological damage 28 days after IRI. Renal echogenicity might have the potential to be a biomarker for the early diagnosis of AKI and the prognosis of CKD.

  6. Treatment of acute cerebral ischemia using animal models: a meta-analysis

    PubMed Central

    Wang, Peng-Fei; Zhou, Yu; Fang, Huang; Lin, Sen; Wang, Yan-Chun; Liu, Yong; Xia, Jun; Eslick, Guy D.; Yang, Qing-Wu

    2015-01-01

    Background There are numerous potential treatments assessed for acute cerebral ischemia using animal models. This study aimed to assess the effect of these treatments in terms of infarct size and neurobehavioral change. This meta-analysis was conducted to determine if any of these treatments provide a superior benefit so that they might be used on humans. Methods A systematic search was conducted using several electronic databases for controlled animal studies using only nonsurgical interventions for acute cerebral ischemia. A random-effects model was used. Results After an extensive literature search, 145 studies were included in the analysis. These studies included 1408 treated animals and 1362 control animals. Treatments that had the most significant effect on neurobehavioral scales included insulin, various antagonists, including N-methyl-D-aspartate (NMDA) receptor antagonist ACEA1021, calmodulin antagonist DY-9760e, and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist YM872, and antiviral agents. Treatments providing the greatest effect on infarct size included statins, sphingosine-1-phosphate agonist (fingolimod), alcohol, angiotensin, and leukotrienes. Treatments offering the greatest reduction in brain water content included various agonists, including sphingosine-1-phosphate agonist fingolimod, statins, and peroxisome proliferator-activated receptor gamma (PPAR-γ). Treatment groups with more than one study all had high heterogeneity (I2 > 80%), however, using meta-regression we determined several sources of heterogeneity including sample size of the treatment and control groups, the occlusion time, but not the year when the study was conducted. Conclusions Some treatments stand out when compared to others for acute cerebral ischemia in animals. Greater replication of treatment studies is required before any treatments are selected for future human trials. PMID:28123790

  7. Acute Thrombotic Mesenteric Ischemia: Primary Endovascular Treatment in Eight Patients

    SciTech Connect

    Gagniere, Johan; Favrolt, Gregory; Alfidja, Agaiecha; Kastler, Adrian; Chabrot, Pascal; Cassagnes, Lucie; Buc, Emmanuel; Pezet, Denis; Boyer, Louis

    2011-10-15

    Introduction: The purpose of this study was to evaluate our experience with initial percutaneous transluminal angioplasty (PTA) {+-} stenting as valuable options in the acute setting. Methods: Between 2003 and 2008, eight patients with abdominal angio-MDCT-scan proven thrombotic AMI benefited from initial PTA {+-} stenting. We retrospectively assessed clinical and radiological findings and their management. Seven patients presented thrombosis of the superior mesenteric artery, and in one patient both mesenteric arteries were occluded. All patients underwent initial PTA and stenting, except one who had balloon PTA alone. One patient was treated by additional in situ thrombolysis. Results: Technical success was obtained in all patients. Three patients required subsequent surgery (37.5%), two of whom had severe radiological findings (pneumatosis intestinalis and/or portal venous gas). Two patients (25%) died: both had NIDD, an ASA score {>=}4, and severe radiologic findings. Satisfactory arterial patency was observed after a follow-up of 15 (range, 11-17) months in five patients who did not require subsequent surgery, four of whom had abdominal guarding but no severe CT scan findings. One patient had an ileocecal stenosis 60 days after the procedure. Conclusions: Initial PTA {+-} stenting is a valuable alternative to surgery for patients with thrombotic AMI even for those with clinical peritoneal irritation signs and/or severe radiologic findings. Early surgery is indicated if clinical condition does not improve after PTA. The decision of a subsequent surgery must be lead by early clinical status reevaluation. In case of underlying atherosclerotic lesion, stenting should be performed after initial balloon dilatation.

  8. Novel hematologic inflammatory parameters to predict acute mesenteric ischemia.

    PubMed

    Toptas, Mehmet; Akkoc, İbrahim; Savas, Yildiray; Uzman, Sinan; Toptas, Yasar; Can, Mehmet Mustafa

    2016-03-01

    Acute mesenteric ischaemia (AMI) is an emergency condition that requires urgent diagnosis. Neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) have been studied as inflammatory biomarkers in atherosclerosis, but data regarding AMI are lacking. The study population included patients with AMI (n = 46) versus age and sex-matched healthy controls (n = 46). Computed multidetector tomographic angiography was performed to diagnose AMI. NLR and PLR were calculated using complete blood count. C-reactive protein (CRP) levels were also analyzed. Neutrophil levels and lymphocytes were significantly higher in patients with AMI than in the control individuals (P < 0.001 and P = 0.43, respectively). NLR levels were significantly higher in patients with AMI compared with that in the control individuals (P < 0.001). Platelet levels did not reach statistical significance between the groups (P = 0.709). However, patients with AMI had significantly higher PLR levels than the control group (P = 0.039). CRP levels on admission were higher in patients with AMI in comparison with control individuals. There was also a positive correlation between NLR and CRP (r = 0.548, P < 0.001), and between PLR and CRP (r = 0.528, P < 0.001). NLR level greater than 4.5, measured on admission, yielded an area under the curve value of 0.790 (95% confidence interval 0.681-0.799, sensitivity 77%, specificity 72%), and PLR level of greater than 157 yielded an area under the curve value of 0.604 (95% confidence interval 0.486-0.722, sensitivity 59%, specificity 65%). Patients with AMI had increased NLR, PLR, and CRP levels compared with controls. Increased NLR and PLR was an independent predictor of AMI.

  9. Acute Limb Ischemia and Coronary Artery Disease in a Case of Kimura’s Disease

    PubMed Central

    Heo, Woon; Jun, Hee Jae; Kang, Do Kyun; Min, Ho-Ki; Hwang, Youn-Ho; Kim, Ji Yong; Nam, Kyung Han

    2017-01-01

    Kimura disease (KD) is an immune-mediated chronic inflammatory disease of unknown etiology. KD has many complications associated with hypereosinophilia, including various forms of allergic reactions and eosinophilic lung disease. Additionally, hypereosinophilia is associated with hypercoagulability, which may lead to thromboembolic events. A 36-year-old man with KD presented with acute limb ischemia and coronary artery occlusion. He underwent thrombectomy, partial endarterectomy of both popliteal arteries, and coronary artery stent insertion. KD is a systemic disease that affects many organs and presents with thromboembolism and vasculitis. In a patient with KD, physicians should evaluate the vascular system, including the coronary arteries. PMID:28382271

  10. Epigenetic intervention with a BET inhibitor ameliorates acute retinal ganglion cell death in mice

    PubMed Central

    Li, Jun; Zhao, Lei; Urabe, Go; Fu, Yingmei

    2017-01-01

    Purpose The bromo and extraterminal (BET) epigenetic “reader” family is becoming an appealing new therapeutic target for several common diseases, yet little is known of its role in retinal neurodegeneration. We explored the potential of BET inhibition in the protection of retinal ganglion cells (RGCs). Methods To test the therapeutic effect of JQ1, an inhibitor highly selective for the BET family of proteins, we used an acute RGC damage model induced by N-methyl-D-aspartic acid (NMDA) excitotoxicity. Adult C57BL/6 mice received an intravitreal injection of NMDA with (or without) JQ1 in one eye and vehicle control in the contralateral eye; RGC loss was assessed on retinal sections and whole mounts. Gene expression and apoptosis were analyzed by quantitative real time (RT)-PCR and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), respectively. For counting RGCs, immunostaining of the marker protein BRN3A was performed on whole mounts. Results NMDA treatment eliminated RGCs (day 7 and day 14 post injection) and diminished the expression (mRNAs) of RGC-selective genes, including Thy1, Nrn1, Sncg, and Nfl (day 3 and day 7). In contrast, co-injection with JQ1 maintained the number and gene expression of RGCs at ~2 fold of the control (NMDA only, no JQ1), and it decreased NMDA-induced TUNEL-positive cells in the RGC layer by 35%. While NMDA treatment dramatically upregulated mRNAs of inflammatory cytokines (TNFα, IL-1β, MCP-1, RANTES) in retinal homogenates, co-injection with JQ1 suppressed their upregulation by ~50%. Conclusions Intravitreal injection of a BET inhibitor (JQ1) ameliorates NMDA-induced RGC death, revealing the RGC-protective potential of pharmacological blockage of the BET family. This new strategy of epigenetic intervention may be extended to other retinal degenerative conditions. PMID:28356707

  11. Acute myocardial ischemia in adults secondary to missed Kawasaki disease in childhood.

    PubMed

    Rizk, Sherif R Y; El Said, Galal; Daniels, Lori B; Burns, Jane C; El Said, Howaida; Sorour, Khaled A; Gharib, Soliman; Gordon, John B

    2015-02-15

    Coronary artery aneurysms that occur in 25% of untreated Kawasaki disease (KD) patients may remain clinically silent for decades and then thrombose resulting in myocardial infarction. Although KD is now the most common cause of acquired heart disease in children in Asia, the United States, and Western Europe, the incidence of KD in Egypt is unknown. We tested the hypothesis that young adults in Egypt presenting with acute myocardial ischemia may have coronary artery lesions because of KD in childhood. We reviewed a total of 580 angiograms of patients ≤40 years presenting with symptoms of myocardial ischemia. Coronary artery aneurysms were noted in 46 patients (7.9%), of whom 9 presented with myocardial infarction. The likelihood of antecedent KD as the cause of the aneurysms was classified as definite (n = 10), probable (n = 29), or equivocal (n = 7). Compared with the definite and probable groups, the equivocal group had more traditional cardiovascular risk factors, smaller sized aneurysms, and fewer coronary arteries affected. In conclusion, in a major metropolitan center in Egypt, 6.7% of adults aged ≤40 years who underwent angiography for evaluation of possible myocardial ischemia had lesions consistent with antecedent KD. Because of the unique therapeutic challenges associated with these lesions, adult cardiologists should be aware that coronary artery aneurysms in young adults may be because of missed KD in childhood.

  12. Combination of tadalafil and diltiazem attenuates renal ischemia reperfusion-induced acute renal failure in rats.

    PubMed

    El-Sisi, Alaa E; Sokar, Samia S; Abu-Risha, Sally E; Ibrahim, Hanaa A

    2016-12-01

    Life threatening conditions characterized by renal ischemia/reperfusion (RIR) such as kidney transplantation, partial nephrectomy, renal artery angioplasty, cardiopulmonary bypass and aortic bypass surgery, continue to be among the most frequent causes of acute renal failure. The current study investigated the possible protective effects of tadalafil alone and in combination with diltiazem in experimentally-induced renal ischemia/reperfusion injury in rats. Possible underlying mechanisms were also investigated such as oxidative stress and inflammation. Rats were divided into sham-operated and I/R-operated groups. Anesthetized rats (urethane 1.3g/kg) were subjected to bilateral ischemia for 30min by occlusion of renal pedicles, then reperfused for 6h. Rats in the vehicle I/R group showed a significant (p˂0.05) increase in kidney malondialdehyde (MDA) content; myeloperoxidase (MPO) activity; TNF-α and IL-1β contents. In addition significant (p˂0.05) increase in intercellular adhesion molecule-1(ICAM-1) content, BUN and creatinine levels, along with significant decrease in kidney superoxide dismutase (SOD) activity. In addition, marked diffuse histopathological damage and severe cytoplasmic staining of caspase-3 were detected. Pretreatment with combination of tadalafil (5mg/kg bdwt) and diltiazem (5mg/kg bdwt) resulted in reversal of the increased biochemical parameters investigated. Also, histopathological examination revealed partial return to normal cellular architecture. In conclusion, pretreatment with tadalafil and diltiazem combination protected against RIR injury.

  13. Acute Myocardial Ischemia in Adults Secondary to Missed Kawasaki Disease in Childhood

    PubMed Central

    Rizk, Sherif RY; El Said, Galal; Daniels, Lori B; Burns, Jane C; El Said, Howaida; Sorour, Khaled A; Gharib, Soliman; Gordon, John B

    2015-01-01

    Coronary artery aneurysms that occur in 25% of untreated Kawasaki disease (KD) patients may remain clinically silent for decades and then thrombose resulting in myocardial infarction. Although KD is now the most common cause of acquired heart disease in children in Asia, the United States, and Western Europe, the incidence of KD in Egypt is unknown. We tested the hypothesis that young adults in Egypt presenting with acute myocardial ischemia may have coronary artery lesions due Kawasaki disease (KD) in childhood. We reviewed a total of 580 angiograms of patients ≤ 40 years of age presenting with symptoms of myocardial ischemia. Coronary artery aneurysms were noted in 46 patients (7.9 %) of whom nine presented with myocardial infarction. The likelihood of antecedent KD as the cause of the aneurysms was classified as definite (n=10), probable (n=29), or equivocal (n=7). Compared to the definite and probable groups, the equivocal group had more traditional cardiovascular risk factors, smaller sized aneurysms, and fewer coronary arteries affected. In conclusion, in a major metropolitan center in Egypt, 6.7% of adults age 40 years or younger undergoing angiography for evaluation of possible myocardial ischemia had lesions consistent with antecedent KD. Because of the unique therapeutic challenges associated with these lesions, adult cardiologists should be aware that coronary artery aneurysms in young adults may be due to missed KD in childhood. PMID:25555655

  14. Automaticity in acute ischemia: Bifurcation analysis of a human ventricular model

    NASA Astrophysics Data System (ADS)

    Bouchard, Sylvain; Jacquemet, Vincent; Vinet, Alain

    2011-01-01

    Acute ischemia (restriction in blood supply to part of the heart as a result of myocardial infarction) induces major changes in the electrophysiological properties of the ventricular tissue. Extracellular potassium concentration ([Ko+]) increases in the ischemic zone, leading to an elevation of the resting membrane potential that creates an “injury current” (IS) between the infarcted and the healthy zone. In addition, the lack of oxygen impairs the metabolic activity of the myocytes and decreases ATP production, thereby affecting ATP-sensitive potassium channels (IKatp). Frequent complications of myocardial infarction are tachycardia, fibrillation, and sudden cardiac death, but the mechanisms underlying their initiation are still debated. One hypothesis is that these arrhythmias may be triggered by abnormal automaticity. We investigated the effect of ischemia on myocyte automaticity by performing a comprehensive bifurcation analysis (fixed points, cycles, and their stability) of a human ventricular myocyte model [K. H. W. J. ten Tusscher and A. V. Panfilov, Am. J. Physiol. Heart Circ. Physiol.AJPHAP0363-613510.1152/ajpheart.00109.2006 291, H1088 (2006)] as a function of three ischemia-relevant parameters [Ko+], IS, and IKatp. In this single-cell model, we found that automatic activity was possible only in the presence of an injury current. Changes in [Ko+] and IKatp significantly altered the bifurcation structure of IS, including the occurrence of early-after depolarization. The results provide a sound basis for studying higher-dimensional tissue structures representing an ischemic heart.

  15. Acute ischemia of bilateral lower extremities as a presenting feature of disseminated mucormycosis endocarditis: A case report

    PubMed Central

    Tachamo, Niranjan; Rajagopalan, Priya; Nazir, Salik; Lohani, Saroj; Le, Brian; Patel, Nitin

    2016-01-01

    Disseminated mucormycosis endocarditis is extremely rare, and only a few cases have actually been reported in the literature. It is almost universally fatal despite aggressive surgical and medical management. In this article, we present the case of a 48-year-old immunocompromised male with mucormycosis endocarditis, who presented with acute bilateral lower extremity ischemia and passed away due to subsequent multi-organ failure. To our knowledge, this is the first case report of disseminated mucormycosis native valve endocarditis presenting as acute bilateral lower extremity ischemia. PMID:27987284

  16. Passage through the Ocular Barriers and Beneficial Effects in Retinal Ischemia of Topical Application of PACAP1-38 in Rodents

    PubMed Central

    Werling, Dora; Banks, William A.; Salameh, Therese S.; Kvarik, Timea; Kovacs, Laszlo Akos; Vaczy, Alexandra; Szabo, Edina; Mayer, Flora; Varga, Rita; Tamas, Andrea; Toth, Gabor; Biro, Zsolt; Atlasz, Tamas; Reglodi, Dora

    2017-01-01

    The neuropeptide pituitary adenylate cyclase activating polypeptide (PACAP) has two active forms, PACAP1-27 and PACAP1-38. Among the well-established actions are PACAP’s neurotrophic and neuroprotective effects, which have also been proven in models of different retinopathies. The route of delivery is usually intravitreal in studies proving PACAP’s retinoprotective effects. Recently, we have shown that PACAP1-27 delivered as eye drops in benzalkonium-chloride was able to cross the ocular barriers and exert retinoprotection in ischemia. Since PACAP1-38 is the dominant form of the naturally occurring PACAP, our aim was to investigate whether the longer form is also able to cross the barriers and exert protective effects in permanent bilateral common carotid artery occlusion (BCCAO), a model of retinal hypoperfusion. Our results show that radioactive PACAP1-38 eye drops could effectively pass through the ocular barriers to reach the retina. Routine histological analysis and immunohistochemical evaluation of the Müller glial cells revealed that PACAP1-38 exerted retinoprotective effects. PACAP1-38 attenuated the damage caused by hypoperfusion, apparent in almost all retinal layers, and it decreased the glial cell overactivation. Overall, our results confirm that PACAP1-38 given in the form of eye drops is a novel protective therapeutic approach to treat retinal diseases. PMID:28335564

  17. Evaluation of ischemia-modified albumin, oxidative stress, and antioxidant status in acute ischemic stroke patients

    PubMed Central

    Jena, Itishri; Nayak, Sarthak Ranjan; Behera, Sudeshna; Singh, Bratati; Ray, Subhashree; Jena, Diptimayee; Singh, Santosh; Sahoo, Subrat Kumar

    2017-01-01

    Background: Oxidative stress is characterized by increased production of reactive oxygen species resulting in the generation of lipid peroxides such as malondialdehyde (MDA). The studies have shown that ischemia-modified albumin (IMA), which has widely been studied as a marker of ischemia, also increases as result of oxidative stress. Hence, the current study was done to evaluate the serum MDA, IMA along with serum uric acid, and albumin, which are important metabolic antioxidants. Materials and Methods: Fifty patients with acute ischemic stroke were taken as cases and compared with 50 age- and sex-matched controls. Serum MDA, IMA, uric acid, and albumin were estimated both in cases and controls. Serum MDA was estimated by the method of Satoh and IMA by Bar-Or et al. The results were analyzed statistically. Results: Serum MDA and IMA values were significantly increased in cases (P < 0.0001), whereas serum uric acid and albumin values were significantly decreased (P < 0.05) in comparison to controls. There was also highly significant positive correlation between serum IMA and MDA (r = 0.843,P < 0.0001), whereas there were significant negative correlations between serum IMA and uric acid (r = −0.237,P < 0.05), and albumin (r = −0.326,P < 0.05). Conclusion: Hence, we conclude the oxidative stress plays a major role in the etiopathogenesis of acute ischemic stroke, and the deranged oxidant-antioxidant balance further contributes to its severity. PMID:28250685

  18. Calpain Inhibition Attenuates Apoptosis of Retinal Ganglion Cells in Acute Optic Neuritis

    PubMed Central

    Smith, Amena W.; Das, Arabinda; Guyton, M. Kelly; Ray, Swapan K.; Rohrer, Baerbel

    2011-01-01

    Purpose. Optic neuritis (ON), inflammation of the optic nerve, is strongly associated with the pathogenesis of multiple sclerosis (MS) and is initiated by the attack of autoreactive T cells against self-myelin antigens, resulting in demyelination, degeneration of retinal ganglion cells (RGCs), and cumulative visual impairment. Methods. Experimental autoimmune encephalomyelitis (EAE) was induced in Lewis rats on day 0, and animals received daily intraperitoneal injections of calpain inhibitor (calpeptin) or vehicle from day 1 until killed. Retinal cell death was analyzed by DNA fragmentation, and surviving ganglion cells were quantified after double labeling of retinal tissue with TUNEL and Brn3a. The expression of apoptotic and inflammatory proteins was determined by Western blotting. Results. It was demonstrated that calpain inhibition downregulates expression of proapoptotic proteins and the proinflammatory molecule nuclear factor-kappa B (NF-κB) in the retina of Lewis rats with acute EAE. Immunofluorescent labeling revealed that apoptotic cells in the RGC layer of vehicle-treated EAE animals were Brn3a positive, and a moderate dose of calpeptin dramatically reduced the frequency of apoptotic RGCs. Conclusions. These results suggest that calpain inhibition might be a useful supplement to immunomodulatory therapies such as corticosteroids in ON, due to its neuroprotective effect on RGCs. PMID:21613375

  19. Can the Preoperative Serum Lactate Level Predict the Extent of Bowel Ischemia in Patients Presenting to the Emergency Department with Acute Mesenteric Ischemia?

    PubMed Central

    Kang, Kai; Papadakis, Marios; Zirngibl, Hubert

    2017-01-01

    Purpose. Early recognition of acute mesenteric ischemia (AMI) can be challenging. Extensive bowel necrosis secondary to AMI is associated with high rates of mortality. The aim of this study was to investigate the association between preoperative serum lactate level and the extent of bowel ischemia in patients with AMI. Methods. Data of patients with abdominal pain and elevated serum lactate undergoing emergency laparotomy for suspected AMI within 24 hours of presentation was retrospectively abstracted. The length of the ischemic bowel segment was compared with the preoperative serum lactate level. Results. 36 female and 39 male patients, with median age 73.1 ± 12.3 years, were included for analysis. The median preoperative lactate was 2.96 ± 2.59 mmol/l in patients with ≤50 cm, 6.86 ± 4.08 mmol/l in patients with 51–100 cm, 4.73 ± 2.76 mmol/l in patients with >100 cm ischemic bowel, and 14.07 ± 4.91 mmol/l in the group with multivisceral ischemia. Conclusion. Although elevated serum lactate might permit an early suspicion and thus influence the clinical decision-making with regard to prioritization of surgery in patients with suspected AMI, a linear relationship between serum lactate and the extent of bowel ischemia could not be established in this study. PMID:28261615

  20. Effect of Valproic Acid on Acute Lung Injury in a Rodent Model of Intestinal Ischemia Reperfusion

    PubMed Central

    Kim, Kyuseok; Li, Yongqing; Jin, Guang; Chong, Wei; Liu, Baoling; Lu, Jennifer; Lee, Kyoungbun; deMoya, Marc; Velmahos, George; Alam, Hasan B.

    2011-01-01

    Objectives Acute lung injury (ALI) is developed in many clinical situations and associated with significant morbidity and mortality. Valproic acid (VPA), a well-known anti-epileptic drug, has been shown to have anti-oxidant and anti-inflammatory effects in various ischemia/reperfusion (I/R) models. The purpose of this study was to investigate whether VPA could affect survival and development of ALI in a rat model of intestinal I/R. Methods Two experiments were performed. Experiment I: Male Sprague-Dawley rats (250–300 g) were subjected to intestinal ischemia (1 hour) and reperfusion (3 hours). They were randomized into 2 groups (n=7/group) 30 min after ischemia: Vehicle (Veh) and VPA (300 mg/kg, IV). Primary end-point for this study was survival over 4 hours from the start of ischemia. Experiment II: The histological and biochemical effects of VPA treatment on lungs were examined 3 hours (1 hr ischemia + 2 hrs reperfusion) after intestinal I/R injury (Veh vs. VPA, n = 9/group). An objective histological score was used to grade the degree of ALI. Enzyme linked immunosorbent assay (ELISA) was performed to measure serum levels of cytokine interleukins (IL-6 and 10), and lung tissue of cytokine-induced neutrophil chemoattractant (CINC) and myeloperoxidase (MPO). In addition, the activity of 8-isoprostane was analyzed for pulmonary oxidative damage. Results In Experiment I, four-hour survival rate was significantly higher in VPA treated animals compared to Veh animals (71.4% vs. 14.3%, p = 0.006). In Experiment II, ALI was apparent in all of the Veh group animals. Treatment with VPA prevented the development of ALI, with a reduction in the histological score (3.4 ± 0.3 vs. 5.3 ± 0.6, p = 0.025). Moreover, compared to the Veh control group the animals from the VPA group displayed decreased serum levels of IL-6 (952 ± 213 vs. 7709 ± 1990 pg/ml, p = 0.011), and lung tissue concentrations of CINC (1188 ± 28 vs. 1298 ± 27, p < 0.05), MPO activity (368 ± 23 vs. 490

  1. Acute intensive insulin therapy exacerbates diabetic blood-retinal barrier breakdown via hypoxia-inducible factor-1α and VEGF

    PubMed Central

    Poulaki, Vassiliki; Qin, Wenying; Joussen, Antonia M.; Hurlbut, Peter; Wiegand, Stanley J.; Rudge, John; Yancopoulos, George D.; Adamis, Anthony P.

    2002-01-01

    Acute intensive insulin therapy is an independent risk factor for diabetic retinopathy. Here we demonstrate that acute intensive insulin therapy markedly increases VEGF mRNA and protein levels in the retinae of diabetic rats. Retinal nuclear extracts from insulin-treated rats contain higher hypoxia-inducible factor-1α (HIF-1α) levels and demonstrate increased HIF-1α–dependent binding to hypoxia-responsive elements in the VEGF promoter. Blood-retinal barrier breakdown is markedly increased with acute intensive insulin therapy but can be reversed by treating animals with a fusion protein containing a soluble form of the VEGF receptor Flt; a control fusion protein has no such protective effect. The insulin-induced retinal HIF-1α and VEGF increases and the related blood-retinal barrier breakdown are suppressed by inhibitors of p38 mitogen-activated protein kinase (MAPK) and phosphatidylinositol (PI) 3-kinase, but not inhibitors of p42/p44 MAPK or protein kinase C. Taken together, these findings indicate that acute intensive insulin therapy produces a transient worsening of diabetic blood-retinal barrier breakdown via an HIF-1α–mediated increase in retinal VEGF expression. Insulin-induced VEGF expression requires p38 MAPK and PI 3-kinase, whereas hyperglycemia-induced VEGF expression is HIF-1α–independent and requires PKC and p42/p44 MAPK. To our knowledge, these data are the first to identify a specific mechanism for the transient worsening of diabetic retinopathy, specifically blood-retinal barrier breakdown, that follows the institution of intensive insulin therapy. PMID:11901189

  2. Acute retinal necrosis results in low vision in a young patient with a history of herpes simplex virus encephalitis.

    PubMed

    Shahi, Sanjeet K

    2016-08-31

    Acute retinal necrosis (ARN), secondary to herpes simplex encephalitis, is a rare syndrome that can present in healthy individuals, as well as immuno-compromised patients. Most cases are caused by a secondary infection from the herpes virus family, with varicella zoster virus being the leading cause of this syndrome. Potential symptoms include blurry vision, floaters, ocular pain and photophobia. Ocular findings may consist of severe uveitis, retinal vasculitis, retinal necrosis, papillitis and retinal detachment. Clinical manifestations of this disease may include increased intraocular pressure, optic disc oedema, optic neuropathy and sheathed retinal arterioles. A complete work up is essential to rule out cytomegalovirus retinitis, herpes simplex encephalitis, herpes virus, syphilis, posterior uveitis and other conditions. Depending on the severity of the disease, the treatment options consist of anticoagulation therapy, cycloplegia, intravenous acyclovir, systemic steroids, prophylactic laser photocoagulation and pars plana vitrectomy with silicon oil for retinal detachment. An extensive history and clinical examination is crucial in making the correct diagnosis. Also, it is very important to be aware of low vision needs and refer the patients, if expressing any sort of functional issues with completing daily living skills, especially reading. In this article, we report one case of unilateral ARN 20 years after herpetic encephalitis.

  3. Acute renal ischemia rapidly activates the energy sensor AMPK but does not increase phosphorylation of eNOS-Ser1177.

    PubMed

    Mount, Peter F; Hill, Rebecca E; Fraser, Scott A; Levidiotis, Vicki; Katsis, Frosa; Kemp, Bruce E; Power, David A

    2005-11-01

    A fundamental aspect of acute renal ischemia is energy depletion, manifest as a falling level of ATP that is associated with a simultaneous rise in AMP. The energy sensor AMP-activated protein kinase (AMPK) is activated by a rising AMP-to-ATP ratio, but its role in acute renal ischemia is unknown. AMPK is activated in the ischemic heart and is reported to phosphorylate both endothelial nitric oxide synthase (eNOS) and acetyl-CoA carboxylase. To study activation of AMPK in acute renal ischemia, the renal pedicle of anesthetized Sprague-Dawley rats was cross-clamped for increasing time intervals. AMPK was strongly activated within 1 min and remained so after 30 min. However, despite the robust activation of AMPK, acute renal ischemia did not increase phosphorylation of the AMPK phosphorylation sites eNOS-Ser(1177) or acetyl-CoA carboxylase-Ser(79). Activation of AMPK in bovine aortic endothelial cells by the ATP-depleting agent antimycin A and the antidiabetic drug phenformin also did not increase phosphorylation of eNOS-Ser(1177), confirming that AMPK activation and phosphorylation of eNOS are dissociated in some situations. Immunoprecipitation studies demonstrated that the dissociation between AMPK activation and phosphorylation of eNOS-Ser(1177) was not due to changes in the physical associations between AMPK, eNOS, or heat shock protein 90. In conclusion, acute renal ischemia rapidly activates the energy sensor AMPK, which is known to maintain ATP reserves during energy stress. The substrates it phosphorylates, however, are different from those in other organs such as the heart.

  4. Acute and chronic nociceptive phases observed in a rat hind paw ischemia/reperfusion model depend on different mechanisms.

    PubMed

    Klafke, J Z; da Silva, M A; Rossato, M F; de Prá, S Dal Toé; Rigo, F K; Walker, C I B; Bochi, G V; Moresco, R N; Ferreira, J; Trevisan, G

    2016-02-01

    Complex regional pain syndrome type 1 (CRPS1) may be evoked by ischemia/reperfusion, eliciting acute and chronic pain that is difficult to treat. Despite this, the underlying mechanism of CRPS1 has not been fully elucidated. Therefore, the goal of this study is to evaluate the involvement of inflammation, oxidative stress, and the transient receptor potential ankyrin 1 (TRPA1) channel, a chemosensor of inflammation and oxidative substances, in an animal model of chronic post-ischemia pain (CPIP). Male Wistar rats were subjected to 3 h hind paw ischemia/reperfusion (CPIP model). Different parameters of nociception, inflammation, ischemia, and oxidative stress were evaluated at 1 (acute) and 14 (chronic) days after CPIP. The effect of a TRPA1 antagonist and the TRPA1 immunoreactivity were also observed after CPIP. In the CPIP acute phase, we observed mechanical and cold allodynia; increased levels of tumor necrosis factor-α (hind paw), ischemia-modified albumin (IMA) (serum), protein carbonyl (hind paw and spinal cord), lactate (serum), and 4-hydroxy-2-nonenal (4-HNE, hind paw and spinal cord); and higher myeloperoxidase (MPO) and N-acetyl-β-D-glucosaminidase (NAGase) activities (hind paw). In the CPIP chronic phase, we detected mechanical and cold allodynia and increased levels of IMA (serum), protein carbonyl (hind paw and spinal cord), and 4-HNE (hind paw and spinal cord). TRPA1 antagonism reduced mechanical and cold allodynia 1 and 14 days after CPIP, but no change in TRPA1 immunoreactivity was observed. Different mechanisms underlie acute (inflammation and oxidative stress) and chronic (oxidative stress) phases of CPIP. TRPA1 activation may be relevant for CRPS1/CPIP-induced acute and chronic pain.

  5. Beat-to-beat QT interval variability associated with acute myocardial ischemia.

    PubMed

    Murabayashi, Taizo; Fetics, Barry; Kass, David; Nevo, Erez; Gramatikov, Boris; Berger, Ronald D

    2002-01-01

    Beat-to-beat QT interval variability (QTV) quantifies lability in ventricular repolarization. We hypothesized that myocardial ischemia destabilizes ventricular repolarization and increases QTV. We analyzed 2-hour 2-lead digitized electrocardiogram records of 68 patients in the European ST-T Database. All patients had ischemic episodes during the 2-hour record, annotated by the developers of the database. We determined the normalized QTV (QTVnorm), QT variability index (QTVI), and normalized heart rate variability (HRVnorm) for each 5-minute epoch by automated analysis. QTVnorm was greater during ischemic episodes than during nonischemic episodes (1.41 +/- 0.77 vs. 0.88 +/- 0.23, P <.0001). There was no significant difference in HRVnorm between ischemic and nonischemic episodes (1.22 +/- 0.63 vs. 0.94 +/- 0.18, not significant). The QTVI was higher during ischemic episodes than during nonischemic episodes (0.14 +/- 0.31 vs. -0.051 +/- 0.12, P <.0001). Acute ischemia is associated with labile ventricular repolarization, which manifests as enhanced beat-to-beat QT interval variability. The association between ischemic repolarization liability and arrhythmic risk deserves further study.

  6. Metabonomic analysis of Allium macrostemon Bunge as a treatment for acute myocardial ischemia in rats.

    PubMed

    Li, Fang; Xu, Qian; Zheng, Ting; Huang, Fang; Han, Lintao

    2014-01-01

    Myocardial ischemia (MI) refers to a pathological state of the heart caused by reduced cardiac blood perfusion, which leads to a decreased oxygen supply in the heart and an abnormal myocardial energy metabolism. Acute myocardial ischemia (AMI) has posed a significant health risk for humans. Allium macrostemon Bunge (AMB), a popular traditional Chinese medicine, is used for MI treatment. The therapeutic effects of AMB were assessed and the detailed mechanisms of AMB for AMI treatment were investigated. We characterized the metabonomic variations in rats from the sham surgery, AMI, and AMB-pretreated AMI groups through a combination of nuclear magnetic resonance (NMR) spectroscopy and multivariate statistical analysis. Thirty-five metabolites including carbohydrates, a range of amino acids, and organic acids were detected. The (1)H NMR spectra of the rat serum were analyzed using the principal component analysis (PCA) and orthogonal projection to latent structures discriminate analysis (OPLS-DA). Results showed that AMI induced some physiological changes in rats and also led to metabolic disorders related to glycolysis promotion, amino acid metabolism disruption, and other metabolite metabolism perturbation. AMB pretreatment reduced the AMI injury and maintained metabolic balance, possibly by limiting the change in energy metabolism and regulating amino acid metabolism. These findings provide a comprehensive insight on the metabolic response of AMI rats to AMB pretreatment and are important for the use of AMB for AMI therapy.

  7. Octreotide Attenuates Acute Kidney Injury after Hepatic Ischemia and Reperfusion by Enhancing Autophagy

    PubMed Central

    Sun, Huiping; Zou, Shuangfa; Candiotti, Keith A.; Peng, Yanhua; Zhang, Qinya; Xiao, Weiqiang; Wen, Yiyun; wu, Jiao; Yang, Jinfeng

    2017-01-01

    Octreotide exerts a protective effect in hepatic ischemia-reperfusion (HIR) injury. However, whether octreotide preconditioning could also reduce acute kidney injury (AKI) after HIR is unknown. This study was designed to investigate the role of octreotide in AKI after HIR. Male Sprague-Dawley rats were pretreated with octreotide or octreotide combined with 3-methyladenine (autophagy inhibitor, 3MA). Plasma creatinine, inflammation markers (e.g., TNF-α and IL-6 etc.), apoptosis, autophagy and phosphorylation of protein kinase B/mammalian target of rapamycin/p70 ribosomal S6 kinase (Akt/mTOR/p70S6K) in the kidney were measured after 60 minutes of liver ischemia and 24 hours of reperfusion for each rat. Octreotide pretreatment significantly preserved renal function and reduced the severity of renal injury. Moreover, octreotide alleviated inflammation and apoptosis in the kidney after HIR. Additionally, octreotide induced autophagy and autophagy inhibition with 3MA markedly reversed the renoprotective, anti-inflammatory and anti-apoptotic effects of octreotide after HIR. Finally, octreotide abrogated the activation of phosphorylation of Akt, mTOR and p70S6K in the kidney after HIR. Our results indicate that octreotide reduced renal injury after HIR due to its induction of autophagy. The enhancement of autophagy may be potentially linked to the octreotide mediated Akt/mTOR/p70S6K pathway deactivation and reduction of kidney inflammation and apoptosis after HIR. PMID:28205545

  8. Toxic Megacolon and Acute Ischemia of the Colon due to Sigmoid Stenosis Related to Diverticulitis

    PubMed Central

    Antonopoulos, P.; Almyroudi, M.; Kolonia, V.; Kouris, S.; Troumpoukis, N.; Economou, N.

    2013-01-01

    We present a rare case of toxic megacolon accompanied by necrosis of the colon due to chronic dilation caused by stenosis of the sigmoid colon as a complication of diverticulitis. The patient presented at the emergency department with diffuse abdominal pain, fever (38.8°C) and tachycardia (120 beats/min). Physical examination revealed distension and tenderness on deep palpation on the left lower quadrant without peritoneal signs. Abdominal computed tomography showed located stenosis in the sigmoid colon and marked dilation of the descending (12 cm diameter) and transverse (7.5 cm diameter) colon. A few hours later, the patient developed severe septic shock with electrolyte abnormalities. He had a history of two prior admissions to our hospital due to crises of acute diverticulitis. Based on Jalan's criteria the diagnosis was compatible with toxic megacolon. The patient's condition deteriorated suddenly and an emergency colectomy was performed. The operative findings revealed a necrotic colon. Histology examination confirmed the diagnosis of ischemia of the colon. To our knowledge this is the first published report in the literature which refers to a rare complication of diverticulitis, namely chronic stenosis which complicated to colonic ischemia and toxic megacolon. PMID:24163654

  9. Unilateral Renal Ischemia-Reperfusion as a Robust Model for Acute to Chronic Kidney Injury in Mice.

    PubMed

    Le Clef, Nathalie; Verhulst, Anja; D'Haese, Patrick C; Vervaet, Benjamin A

    2016-01-01

    Acute kidney injury (AKI) is an underestimated, yet important risk factor for development of chronic kidney disease (CKD). Even after initial total recovery of renal function, some patients develop progressive and persistent deterioration of renal function and these patients are more likely to progress to end-stage renal disease (ESRD). Animal models are indispensable for unravelling the mechanisms underlying this progression towards CKD and ESRD and for the development of new therapeutic strategies in its prevention or treatment. Ischemia (i.e. hypoperfusion after surgery, bleeding, dehydration, shock, or sepsis) is a major aetiology in human AKI, yet unilateral ischemia-reperfusion is a rarely used animal model for research on CKD and fibrosis. Here, we demonstrate in C57Bl/6J mice, by both histology and gene expression, that unilateral ischemia-reperfusion without contralateral nephrectomy is a very robust model to study the progression from acute renal injury to long-term tubulo-interstitial fibrosis, i.e. the histopathological hallmark of CKD. Furthermore, we report that the extent of renal fibrosis, in terms of Col I, TGFβ, CCN2 and CCN3 expression and collagen I immunostaining, increases with increasing body temperature during ischemia and ischemia-time. Thus, varying these two main determinants of ischemic injury allows tuning the extent of the long-term fibrotic outcome in this model. Finally, in order to cover the whole practical finesse of ischemia-reperfusion and allow model and data transfer, we provide a referenced overview on crucial technical issues (incl. anaesthesia, analgesia, and pre- and post-operative care) with the specific aim of putting starters in the right direction of implementing ischemia in their research and stimulate them, as well as the community, to have a critical view on ischemic literature data.

  10. Cardiac progenitor-derived exosomes protect ischemic myocardium from acute ischemia/reperfusion injury

    SciTech Connect

    Chen, Lijuan; Wang, Yingjie; Pan, Yaohua; Zhang, Lan; Shen, Chengxing; Qin, Gangjian; Ashraf, Muhammad; Weintraub, Neal; Ma, Genshan; Tang, Yaoliang

    2013-02-15

    Highlights: ► Cardiac progenitor-derived (CPC) Exosomes protect H9C2 from apoptosis in vitro. ► CPC-exosomes protect cardiomyoyctes from MI/R induced apoptosis in vivo. ► CPC-exosomes were taken up by H9C2 with high efficiency using PKH26 labeling. ► miR-451, one of GATA4-responsive miRNA cluster, is enriched in CPC-exosomes. -- Abstract: Background: Cardiac progenitors (CPC) mediate cardioprotection via paracrine effects. To date, most of studies focused on secreted paracrine proteins. Here we investigated the CPC-derived-exosomes on protecting myocardium from acute ischemia/reperfusion (MI/R) injury. Methods and results: CPC were isolated from mouse heart using two-step protocol. Exosomes were purified from conditional medium, and confirmed by electron micrograph and Western blot using CD63 as a marker. qRT-PCR shows that CPC-exosomes have high level expression of GATA4-responsive-miR-451. Exosomes were ex vivo labeled with PKH26, We observed exosomes can be uptaken by H9C2 cardiomyoblasts with high efficiency after 12 h incubation. CPC-exosomes protect H9C2 from oxidative stress by inhibiting caspase 3/7 activation invitro. In vivo delivery of CPC-exosomes in an acute mouse myocardial ischemia/reperfusion model inhibited cardiomyocyte apoptosis by about 53% in comparison with PBS control (p < 0.05). Conclusion: Our results suggest, for the first time, the CPC-exosomes can be used as a therapeutic vehicle for cardioprotection, and highlights a new perspective for using non-cell exosomes for cardiac disease.

  11. The relative role of refractoriness and source-sink relationship in reentry generation during simulated acute ischemia.

    PubMed

    Romero, Lucía; Trénor, Beatriz; Alonso, José M; Tobón, Catalina; Saiz, Javier; Ferrero, José M

    2009-08-01

    During acute myocardial ischemia, reentrant episodes may lead to ventricular fibrillation (VF), giving rise to potentially mortal arrhythmias. VF has been traditionally related to dispersion of refractoriness and more recently to the source-sink relationship. Our goal is to theoretically investigate the relative role of dispersion of refractoriness and source-sink mismatch in vulnerability to reentry in the specific situation of regional myocardial acute ischemia. The electrical activity of a regionally ischemic tissue was simulated using a modified version of the Luo-Rudy dynamic model. Ischemic conditions were varied to simulate the time-course of acute ischemia. Our results showed that dispersion of refractoriness increased with the severity of ischemia. However, no correlation between dispersion of refractoriness and the width of the vulnerable window was found. Additionally, in approximately 50% of the reentries, unidirectional block (UDB) took place in cells completely recovered from refractoriness. We examined patterns of activation after premature stimulation and they were intimately related to the source-sink relationship, quantified by the safety factor (SF). Moreover, the isoline where the SF dropped below unity matched the area where propagation failed. It was concluded that the mismatch of the source-sink relationship, rather than solely refractoriness, was the ultimate cause of the UDB leading to reentry. The SF represents a very powerful tool to study the mechanisms responsible for reentry.

  12. DJ-1 protects against cell death following acute cardiac ischemia-reperfusion injury.

    PubMed

    Dongworth, R K; Mukherjee, U A; Hall, A R; Astin, R; Ong, S-B; Yao, Z; Dyson, A; Szabadkai, G; Davidson, S M; Yellon, D M; Hausenloy, D J

    2014-02-27

    Novel therapeutic targets are required to protect the heart against cell death from acute ischemia-reperfusion injury (IRI). Mutations in the DJ-1 (PARK7) gene in dopaminergic neurons induce mitochondrial dysfunction and a genetic form of Parkinson's disease. Genetic ablation of DJ-1 renders the brain more susceptible to cell death following ischemia-reperfusion in a model of stroke. Although DJ-1 is present in the heart, its role there is currently unclear. We sought to investigate whether mitochondrial DJ-1 may protect the heart against cell death from acute IRI by preventing mitochondrial dysfunction. Overexpression of DJ-1 in HL-1 cardiac cells conferred the following beneficial effects: reduced cell death following simulated IRI (30.4±4.7% with DJ-1 versus 52.9±4.7% in control; n=5, P<0.05); delayed mitochondrial permeability transition pore (MPTP) opening (a critical mediator of cell death) (260±33 s with DJ-1 versus 121±12 s in control; n=6, P<0.05); and induction of mitochondrial elongation (81.3±2.5% with DJ-1 versus 62.0±2.8% in control; n=6 cells, P<0.05). These beneficial effects of DJ-1 were absent in cells expressing the non-functional DJ-1(L166P) and DJ-1(Cys106A) mutants. Adult mice devoid of DJ-1 (KO) were found to be more susceptible to cell death from in vivo IRI with larger myocardial infarct sizes (50.9±3.5% DJ-1 KO versus 41.1±2.5% in DJ-1 WT; n≥7, P<0.05) and resistant to cardioprotection by ischemic preconditioning. DJ-1 KO hearts showed increased mitochondrial fragmentation on electron microscopy, although there were no differences in calcium-induced MPTP opening, mitochondrial respiratory function or myocardial ATP levels. We demonstrate that loss of DJ-1 protects the heart from acute IRI cell death by preventing mitochondrial dysfunction. We propose that DJ-1 may represent a novel therapeutic target for cardioprotection.

  13. A novel laser-Doppler flowmetry assisted murine model of acute hindlimb ischemia-reperfusion for free flap research.

    PubMed

    Sönmez, Tolga Taha; Al-Sawaf, Othman; Brandacher, Gerald; Kanzler, Isabella; Tuchscheerer, Nancy; Tohidnezhad, Mersedeh; Kanatas, Anastasios; Knobe, Matthias; Fragoulis, Athanassios; Tolba, René; Mitchell, David; Pufe, Thomas; Wruck, Christoph Jan; Hölzle, Frank; Liehn, Elisa Anamaria

    2013-01-01

    Suitable and reproducible experimental models of translational research in reconstructive surgery that allow in-vivo investigation of diverse molecular and cellular mechanisms are still limited. To this end we created a novel murine model of acute hindlimb ischemia-reperfusion to mimic a microsurgical free flap procedure. Thirty-six C57BL6 mice (n = 6/group) were assigned to one control and five experimental groups (subject to 6, 12, 96, 120 hours and 14 days of reperfusion, respectively) following 4 hours of complete hindlimb ischemia. Ischemia and reperfusion were monitored using Laser-Doppler Flowmetry. Hindlimb tissue components (skin and muscle) were investigated using histopathology, quantitative immunohistochemistry and immunofluorescence. Despite massive initial tissue damage induced by ischemia-reperfusion injury, the structure of the skin component was restored after 96 hours. During the same time, muscle cells were replaced by young myotubes. In addition, initial neuromuscular dysfunction, edema and swelling resolved by day 4. After two weeks, no functional or neuromuscular deficits were detectable. Furthermore, upregulation of VEGF and tissue infiltration with CD34-positive stem cells led to new capillary formation, which peaked with significantly higher values after two weeks. These data indicate that our model is suitable to investigate cellular and molecular tissue alterations from ischemia-reperfusion such as occur during free flap procedures.

  14. Peritoneal Potassium and pH Measurement in Early Diagnosis of Acute Mesenteric Ischemia in Rats

    PubMed Central

    Hosseinpour, Mehrdad; Khamechian, Tahere; Shahrokh, Soraya

    2014-01-01

    Background: In contemporary practice, acute mesenteric ischemia (AMI) remains a serious cause of morbidity and mortality in abdominal emergencies. Objectives: We report the measurement of peritoneal fluid potassium and pH on a small series of rats that developed extensive AMI following the surgical ligation of superior mesenteric vessels and compare the results with control groups. Materials and Methods: A total of 32 rats were used in our study. They were divided into four groups with eight rats in each one and received following treatments: group I (G-I), 60-minute controls; group II (G-II), 120-minute controls; group III (G-III), 60-minute cases; and group IV (G-IV), 120-minute cases. In case groups, the small bowel mesenteric root was double-ligated and an arrow single-lumen central venous catheter was passed through the skin to the peritoneum. In control groups, the catheter was placed without any intervention. Postoperatively, peritoneal lavage was performed at 60 (G-I, G-III) and 120 minutes (G-II, G-IV). Results: The mean peritoneal potassium values were 1.3 ± 0.3, 1.97 ± 1.06, 2.14 ± 0.89, and 3.28 ± 0.66 mmol/L in G-I, G-II, G-III, and G-IV, respectively. There were significant differences between G-III and G-IV (P = 0.002), between G-I and G-III (P = 0.024), and between G-II and G-IV (P = 0.001). The mean values of peritoneal fluid pH were 7.1 ± 0.26, 6.82 ± 0.22, 6.66 ± 0.16, and 6.78 ± 0.04 in G-I, G-II, G-III, and G-IV, respectively, which indicated significant differences between G-I and G-III (P = 0.001) and between G-II and G-IV (P = 0.018). There was a significant correlation between peritoneal fluid potassium and intestine ischemic grade (F = 4.77, P = 0.048) Conclusions Our findings show that for early detection of bowel ischemia, an evaluation of intraperitoneal potassium and pH was useful and with prolongation of ischemia, potassium changes were more significant. PMID:25599068

  15. Acute T3 treatment protects the heart against ischemia-reperfusion injury via TRα1 receptor.

    PubMed

    Pantos, Constantinos; Mourouzis, Iordanis; Saranteas, Theodosios; Brozou, Vassiliki; Galanopoulos, Georgios; Kostopanagiotou, Georgia; Cokkinos, Dennis V

    2011-07-01

    We have previously shown that acute thyroid hormone treatment could limit reperfusion injury and increase post-ischemic recovery of function. In the present study, we further explore potential initiating mechanisms of this response. Thus, isolated rat hearts were subjected to 30 min zero-flow global ischemia (I) followed by 60-min reperfusion (R). Reperfusion injury was assessed by post-ischemic recovery of left ventricular developed pressure (LVDP%) and LDH release. T3 at a dose of 60 nM which had no effect on contractile function of non-ischemic myocardium, significantly increased LVDP% [48% (2.9) vs. 30.2% (3.3) for untreated group, P < 0.05] and reduced LDH release [8.3 (0.3) vs. 10 (0.42) for untreated group, P < 0.05] when administered at R. T4 (60 and 400 nM) had no effect on contractile function either in non-ischemic or ischemic myocardium. Administration of debutyl-dronedarone (DBD), a TRα1 antagonist abolished the T3-limiting effect on reperfusion injury: Thus, co-administration of T3 and DBD resulted in significantly lower LVDP%, [23% (4.7) vs. 48% (2.9) for T3 group, P < 0.05] and higher LDH release [9.9 (0.3) vs. 8.3 (0.3), for T3 group, P < 0.05]. In conclusion, acute T3 and not T4 treatment will be able to protect against reperfusion injury. T3 can exert this beneficial effect on ischemic myocardium at a dose that has no effects on non-ischemic myocardium. Acute T3-limiting effect on reperfusion injury is mediated, at least in part, via TRα1 receptor.

  16. Sex differences in ischemia/reperfusion-induced acute kidney injury are dependent on the renal sympathetic nervous system.

    PubMed

    Tanaka, Ryosuke; Tsutsui, Hidenobu; Ohkita, Mamoru; Takaoka, Masanori; Yukimura, Tokihito; Matsumura, Yasuo

    2013-08-15

    Resistance to ischemic acute kidney injury has been shown to be higher in female rats than in male rats. We found that renal venous norepinephrine overflow after reperfusion played important roles in the development of ischemic acute kidney injury. In the present study, we investigated whether sex differences in the pathogenesis of ischemic acute kidney injury were derived from the renal sympathetic nervous system using male and female Sprague-Dawley rats. Ischemia/reperfusion-induced acute kidney injury was achieved by clamping the left renal artery and vein for 45 min followed by reperfusion, 2 weeks after contralateral nephrectomy. Renal function was impaired after reperfusion in both male and female rats; however, renal dysfunction and histological damage were more severe in male rats than in female rats. Renal venous plasma norepinephrine levels after reperfusion were markedly elevated in male rats, but were not in female rats. These sex differences were eliminated by ovariectomy or treatment with tamoxifen, an estrogen receptor antagonist, in female rats. Furthermore, an intravenous injection of hexamethonium (25mg/kg), a ganglionic blocker, 5 min before ischemia suppressed the elevation in renal venous plasma norepinephrine levels after reperfusion, and attenuated renal dysfunction and histological damage in male rats, and ovariectomized and tamoxifen-treated female rats, but not in intact females. Thus, the present findings confirmed sex differences in the pathogenesis of ischemic acute kidney injury, and showed that the attenuation of ischemia/reperfusion-induced acute kidney injury observed in intact female rats may be dependent on depressing the renal sympathetic nervous system with endogenous estrogen.

  17. Endovascular Therapy as a Primary Revascularization Modality in Acute Mesenteric Ischemia

    SciTech Connect

    Kärkkäinen, Jussi M.; Lehtimäki, Tiina T. Saari, Petri; Hartikainen, Juha; Rantanen, Tuomo Paajanen, Hannu; Manninen, Hannu

    2015-10-15

    PurposeTo evaluate endovascular therapy (EVT) as the primary revascularization method for acute mesenteric ischemia (AMI).MethodsA retrospective review was performed on all consecutive patients treated for AMI during a 5-year period (January 2009 to December 2013). EVT was attempted in all patients referred for emergent revascularization. Surgical revascularization was performed selectively after failure of EVT. Patient characteristics, clinical presentation, and outcomes were studied. Failures and complications of EVT were recorded.ResultsFifty patients, aged 79 ± 9 years (mean ± SD), out of 66 consecutive patients with AMI secondary to embolic or thrombotic obstruction of the superior mesenteric artery were referred for revascularization. The etiology of AMI was embolism in 18 (36 %) and thrombosis in 32 (64 %) patients. EVT was technically successful in 44 (88 %) patients. Mortality after successful or failed EVT was 32 %. The rates of emergency laparotomy, bowel resection, and EVT-related complication were 40, 34, and 10 %, respectively. Three out of six patients with failure of EVT were treated with surgical bypass. EVT failure did not significantly affect survival.ConclusionsEVT is feasible in most cases of AMI, with favorable patient outcome and acceptable complication rate.

  18. Acute Mesenteric Ischemia after Cardiac Surgery: An Analysis of 52 Patients

    PubMed Central

    Gucu, Arif; Toktas, Faruk; Erdolu, Burak; Ozyazıcıoglu, Ahmet

    2013-01-01

    Objective. Acute mesenteric ischemia (AMI) is a rare but serious complication after cardiac surgery. The aim of this retrospective study was to evaluate the incidence, outcome, and perioperative risk factors of AMI in the patients undergoing elective cardiac surgery. Methods. From January 2005 to May 2013, all patients who underwent cardiac surgery were screened for participation, and patients with registered gastrointestinal complications were retrospectively reviewed. Univariate analyses were performed. Results. The study included 6013 patients, of which 52 (0.86%) patients suffered from AMI, 35 (67%) of whom died. The control group (150 patients) was randomly chosen from among cases undergoing cardiopulmonary bypass (CPB). Preoperative parameters including age (P = 0.03), renal insufficiency (P = 0.004), peripheral vascular disease (P = 0.04), preoperative inotropic support (P < 0.001), poor left ventricular ejection fraction (P = 0.002), cardiogenic shock (P = 0.003), and preoperative intra-aortic balloon pump (IABP) support (P = 0.05) revealed significantly higher levels in the AMI group. Among intra- and postoperative parameters, CPB time (P < 0.001), dialysis (P = 0.04), inotropic support (P = 0.007), prolonged ventilator time (P < 0.001), and IABP support (P = 0.007) appeared significantly higher in the AMI group than the control group. Conclusions. Prompt diagnosis and early treatment should be initiated as early as possible in any patient suspected of AMI, leading to dramatic reduction in the mortality rate. PMID:24288499

  19. Protective Effect of N-Acetylserotonin against Acute Hepatic Ischemia-Reperfusion Injury in Mice

    PubMed Central

    Yu, Shuna; Zheng, Jie; Jiang, Zhengchen; Shi, Caixing; Li, Jin; Du, Xiaodong; Wang, Hailiang; Jiang, Jiying; Wang, Xin

    2013-01-01

    The purpose of this study was to investigate the possible protective effect of N-acetylserotonin (NAS) against acute hepatic ischemia-reperfusion (I/R) injury in mice. Adult male mice were randomly divided into three groups: sham, I/R, and I/R + NAS. The hepatic I/R injury model was generated by clamping the hepatic artery, portal vein, and common bile duct with a microvascular bulldog clamp for 30 min, and then removing the clamp and allowing reperfusion for 6 h. Morphologic changes and hepatocyte apoptosis were evaluated by hematoxylin-eosin (HE) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, respectively. Activated caspase-3 expression was evaluated by immunohistochemistry and Western blot. The activation of aspartate aminotransferase (AST), malondialdehyde (MDA), and superoxide dismutase (SOD) was evaluated by enzyme-linked immunosorbent assay (ELISA). The data show that NAS rescued hepatocyte morphological damage and dysfunction, decreased the number of apoptotic hepatocytes, and reduced caspase-3 activation. Our work demonstrates that NAS ameliorates hepatic IR injury. PMID:23994834

  20. Protease-Activated Receptor 4 Deficiency Offers Cardioprotection after Acute Ischemia Reperfusion Injury

    PubMed Central

    Kolpakov, Mikhail A.; Rafiq, Khadija; Guo, Xinji; Hooshdaran, Bahman; Wang, Tao; Vlasenko, Liudmila; Bashkirova, Yulia V.; Zhang, Xiaoxiao; Chen, Xiongwen; Iftikhar, Sahar; Libonati, Joseph R.; Kunapuli, Satya P.; Sabri, Abdelkarim

    2016-01-01

    Protease-activated receptor (PAR)4 is a low affinity thrombin receptor with less understood function relative to PAR1. PAR4 is involved in platelet activation and hemostasis, but its specific actions on myocyte growth and cardiac function remain unknown. This study examined the role of PAR4 deficiency on cardioprotection after myocardial ischemia-reperfusion (IR) injury in mice. When challenged by in vivo or ex vivo IR, PAR4 knockout (KO) mice exhibited increased tolerance to injury, which was manifest as reduced infarct size and a more robust functional recovery compared to wild-type mice. PAR4 KO mice also showed reduced cardiomyocyte apoptosis and putative signaling shifts in survival pathways in response to IR. Inhibition of PAR4 expression in isolated cardiomyocytes by shRNA offered protection against thrombin and PAR4-agonist peptide-induced apoptosis, while overexpression of wild-type PAR4 significantly enhanced the susceptibility of cardiomyocytes to apoptosis, even under low thrombin concentrations. Further studies implicate Src- and epidermal growth factor receptor-dependent activation of JNK on the proapoptotic effect of PAR4 in cardiomyocytes. These findings reveal a pivotal role for PAR4 as a regulator of cardiomyocyte survival and point to PAR4 inhibition as a therapeutic target offering cardioprotection after acute IR injury. PMID:26643815

  1. Cannabidiol reduces brain damage and improves functional recovery after acute hypoxia-ischemia in newborn pigs.

    PubMed

    Lafuente, Hector; Alvarez, Francisco J; Pazos, M Ruth; Alvarez, Antonia; Rey-Santano, M Carmen; Mielgo, Victoria; Murgia-Esteve, Xabier; Hilario, Enrique; Martinez-Orgado, José

    2011-09-01

    Newborn piglets exposed to acute hypoxia-ischemia (HI) received i.v. cannabidiol (HI + CBD) or vehicle (HI + VEH). In HI + VEH, 72 h post-HI brain activity as assessed by amplitude-integrated EEG (aEEG) had only recovered to 42 ± 9% of baseline, near-infrared spectroscopy (NIRS) parameters remained lower than normal, and neurobehavioral performance was abnormal (27.8 ± 2.3 points, normal 36). In the brain, there were fewer normal and more pyknotic neurons, while astrocytes were less numerous and swollen. Cerebrospinal fluid concentration of neuronal-specific enolase (NSE) and S100β protein and brain tissue percentage of TNFα(+) cells were all higher. In contrast, in HI + CBD, aEEG had recovered to 86 ± 5%, NIRS parameters increased, and the neurobehavioral score normalized (34.3 ± 1.4 points). HI induced histological changes, and NSE and S100β concentration and TNFα(+) cell increases were suppressed by CBD. In conclusion, post-HI administration of CBD protects neurons and astrocytes, leading to histological, functional, biochemical, and neurobehavioral improvements.

  2. Ischemia/Reperfusion Injury following Acute Myocardial Infarction: A Critical Issue for Clinicians and Forensic Pathologists

    PubMed Central

    Neri, Margherita; Pascale, Natascha; Pomara, Cristoforo

    2017-01-01

    Acute myocardial infarction (AMI) is a leading cause of morbidity and mortality. Reperfusion strategies are the current standard therapy for AMI. However, they may result in paradoxical cardiomyocyte dysfunction, known as ischemic reperfusion injury (IRI). Different forms of IRI are recognized, of which only the first two are reversible: reperfusion-induced arrhythmias, myocardial stunning, microvascular obstruction, and lethal myocardial reperfusion injury. Sudden death is the most common pattern for ischemia-induced lethal ventricular arrhythmias during AMI. The exact mechanisms of IRI are not fully known. Molecular, cellular, and tissue alterations such as cell death, inflammation, neurohumoral activation, and oxidative stress are considered to be of paramount importance in IRI. However, comprehension of the exact pathophysiological mechanisms remains a challenge for clinicians. Furthermore, myocardial IRI is a critical issue also for forensic pathologists since sudden death may occur despite timely reperfusion following AMI, that is one of the most frequently litigated areas of cardiology practice. In this paper we explore the literature regarding the pathophysiology of myocardial IRI, focusing on the possible role of the calpain system, oxidative-nitrosative stress, and matrix metalloproteinases and aiming to foster knowledge of IRI pathophysiology also in terms of medicolegal understanding of sudden deaths following AMI. PMID:28286377

  3. Acute retinal necrosis (ARN) in the context of neonatal HSV-2 exposure and subconjunctival dexamethasone: case report and literature review.

    PubMed

    McGrath, Lindsay; Woods, Marion; Lee, Lawrence; Conrad, Diana

    2013-01-01

    HSV-2 is an important cause of the acute retinal necrosis (ARN) syndrome in younger patients. We describe an atypical case of HSV-2 ARN in the context of neonatal exposure and subconjunctival steroid injection. Clinicians should be aware of the association of neonatal or congenital exposure to HSV-2 as a risk factor for this disease because early treatment may improve outcome and/or avoid involvement of both eyes.

  4. Compound danshen dripping pills modulate the perturbed energy metabolism in a rat model of acute myocardial ischemia.

    PubMed

    Guo, Jiahua; Yong, Yonghong; Aa, Jiye; Cao, Bei; Sun, Runbin; Yu, Xiaoyi; Huang, Jingqiu; Yang, Na; Yan, Lulu; Li, Xinxin; Cao, Jing; Aa, Nan; Yang, Zhijian; Kong, Xiangqing; Wang, Liansheng; Zhu, Xuanxuan; Ma, Xiaohui; Guo, Zhixin; Zhou, Shuiping; Sun, He; Wang, Guangji

    2016-12-01

    The continuous administration of compound danshen dripping pills (CDDP) showed good efficacy in relieving myocardial ischemia clinically. To probe the underlying mechanism, metabolic features were evaluated in a rat model of acute myocardial ischemia induced by isoproterenol (ISO) and administrated with CDDP using a metabolomics platform. Our data revealed that the ISO-induced animal model showed obvious myocardial injury, decreased energy production, and a marked change in metabolomic patterns in plasma and heart tissue. CDDP pretreatment increased energy production, ameliorated biochemical indices, modulated the changes and metabolomic pattern induced by ISO, especially in heart tissue. For the first time, we found that ISO induced myocardial ischemia was accomplished with a reduced fatty acids metabolism and an elevated glycolysis for energy supply upon the ischemic stress; while CDDP pretreatment prevented the tendency induced by ISO and enhanced a metabolic shift towards fatty acids metabolism that conventionally dominates energy supply to cardiac muscle cells. These data suggested that the underlying mechanism of CDDP involved regulating the dominant energy production mode and enhancing a metabolic shift toward fatty acids metabolism in ischemic heart. It was further indicated that CDDP had the potential to prevent myocardial ischemia in clinic.

  5. Compound danshen dripping pills modulate the perturbed energy metabolism in a rat model of acute myocardial ischemia

    PubMed Central

    Guo, Jiahua; Yong, Yonghong; Aa, Jiye; Cao, Bei; Sun, Runbin; Yu, Xiaoyi; Huang, Jingqiu; Yang, Na; Yan, Lulu; Li, Xinxin; Cao, Jing; Aa, Nan; Yang, Zhijian; Kong, Xiangqing; Wang, Liansheng; Zhu, Xuanxuan; Ma, Xiaohui; Guo, Zhixin; Zhou, Shuiping; Sun, He; Wang, Guangji

    2016-01-01

    The continuous administration of compound danshen dripping pills (CDDP) showed good efficacy in relieving myocardial ischemia clinically. To probe the underlying mechanism, metabolic features were evaluated in a rat model of acute myocardial ischemia induced by isoproterenol (ISO) and administrated with CDDP using a metabolomics platform. Our data revealed that the ISO-induced animal model showed obvious myocardial injury, decreased energy production, and a marked change in metabolomic patterns in plasma and heart tissue. CDDP pretreatment increased energy production, ameliorated biochemical indices, modulated the changes and metabolomic pattern induced by ISO, especially in heart tissue. For the first time, we found that ISO induced myocardial ischemia was accomplished with a reduced fatty acids metabolism and an elevated glycolysis for energy supply upon the ischemic stress; while CDDP pretreatment prevented the tendency induced by ISO and enhanced a metabolic shift towards fatty acids metabolism that conventionally dominates energy supply to cardiac muscle cells. These data suggested that the underlying mechanism of CDDP involved regulating the dominant energy production mode and enhancing a metabolic shift toward fatty acids metabolism in ischemic heart. It was further indicated that CDDP had the potential to prevent myocardial ischemia in clinic. PMID:27905409

  6. Core-shell hybrid liposomal vesicles loaded with panax notoginsenoside: preparation, characterization and protective effects on global cerebral ischemia/reperfusion injury and acute myocardial ischemia in rats

    PubMed Central

    Zhang, Jing; Han, Xizhen; Li, Xiang; Luo, Yun; Zhao, Haiping; Yang, Ming; Ni, Bin; Liao, Zhenggen

    2012-01-01

    Purpose: Novel panax notoginsenoside-loaded core-shell hybrid liposomal vesicles (PNS-HLV) were developed to resolve the restricted bioavailability of PNS and to enhance its protective effects in vivo on oral administration. Methods: Physicochemical characterizations of PNS-HLV included assessment of morphology, particle size and zeta potential, encapsulation efficiency (EE%), stability and in vitro release study. In addition, to evaluate its oral treatment potential, we compared the effect of PNS-HLV on global cerebral ischemia/reperfusion and acute myocardial ischemia injury with those of PNS solution, conventional PNS-loaded nanoparticles, and liposomes. Results: In comparison with PNS solution, conventional PNS-loaded nanoparticles and liposomes, PNS-HLV was stable for at least 12 months at 4°C. Satisfactory improvements in the EE% of notoginsenoside R1, ginsenoside Rb1, and ginsenoside Rg1 were shown with the differences in EE% shortened and the greater controlled drug release profiles were exhibited from PNS-HLV. The improvements in the physicochemical properties of HLV contributed to the results that PNS-HLV was able to significantly inhibit the edema of brain and reduce the infarct volume, while it could markedly inhibit H2O2, modified Dixon agar, and serum lactate dehydrogenase, and increase superoxide dismutase (P < 0.05). Conclusion: The results of the present study imply that HLV has promising prospects for improving free drug bioactivity on oral administration. PMID:22915851

  7. Protective effect of moxonidine on ischemia/reperfusion-induced acute kidney injury through α2/imidazoline I1 receptor.

    PubMed

    Tsutsui, Hidenobu; Sugiura, Takahiro; Hayashi, Kentaro; Yukimura, Tokihito; Ohkita, Mamoru; Takaoka, Masanori; Matsumura, Yasuo

    2013-10-15

    Enhancement of renal sympathetic nerve activity during renal ischemia and norepinephrine overflow from the kidney after reperfusion play important roles in the development of ischemic acute kidney injury. Recently, we have found that moxonidine, an α2/imidazoline Ι1-receptor agonist, has preventive effects on ischemic acute kidney injury by suppressing the excitation of renal sympathetic nervous system after reperfusion. In the present study, to clarify the renoprotective mechanisms of moxonidine (360 nmol/kg, i.v.) against ischemic acute kidney injury, we investigated the effect of intravenous (i.v.) and intracerebroventricular (i.c.v.) injection of efaroxan, an α2/Ι1 receptor antagonist, on the moxonidine-exhibited actions. Ischemic acute kidney injury was induced by clamping the left renal artery and vein for 45 min followed by reperfusion, 2 weeks after contralateral nephrectomy. The suppressive effect of moxonidine on enhanced renal sympathetic nerve activity during renal ischemia was not observed in the rat treated with either i.v. (360 nmol/kg) or i.c.v. (36 nmol/kg) of efaroxan. Furthermore, i.v. injection of efaroxan eliminated the preventive effect of moxonidine on ischemia/reperfusion-induced kidney injury and norepinephrine overflow, and i.c.v. injection of efaroxan did not completely inhibit the moxonidine's effects. These results indicate that moxonidine prevents the ischemic kidney injury by sympathoinhibitory effect probably via α2/Ι1 receptors in central nervous system and by suppressing the norepinephrine overflow through α2/Ι1 receptors on sympathetic nerve endings.

  8. Successful Thrombolysis and Spasmolysis of Acute Leg Ischemia after Accidental Intra-arterial Injection of Dissolved Flunitrazepam Tablets

    SciTech Connect

    Radeleff, B. Stampfl, U.; Sommer, C.-M.; Bellemann, N.; Hyhlik-Duerr, A.; Weber, M.-A.; Boeckler, D.; Kauczor, H.-U.

    2011-10-15

    A 37-year-old man with known intravenous drug abuse presented in the surgical ambulatory care unit with acute leg ischemia after accidental intra-arterial injection of dissolved flunitrazepam tablets into the right femoral artery. A combination of anticoagulation, vasodilatation, and local selective and superselective thrombolysis with urokinase was performed to salvage the leg. As a result of the severe ischemia-induced pain, the patient had to be monitored over the complete therapy period on the intensive care unit with permanent administration of intravenous fluid and analgetics. We describe the presenting symptoms and the interventional technique, and we discuss the recent literature regarding the management of accidental intra-arterial injection of dissolved flunitrazepam tablets.

  9. Dipyridamole attenuates ischemia reperfusion induced acute kidney injury through adenosinergic A1 and A2A receptor agonism in rats.

    PubMed

    Puri, Nikkita; Mohey, Vinita; Singh, Manjinder; Kaur, Tajpreet; Pathak, Devendra; Buttar, Harpal Singh; Singh, Amrit Pal

    2016-04-01

    Dipyridamole (DYP) is an anti-platelet agent with marked vasodilator, anti-oxidant, and anti-inflammatory activity. The present study investigated the role of adenosine receptors in DYP-mediated protection against ischemia reperfusion-induced acute kidney injury (AKI) in rats. The rats were subjected to bilateral renal ischemia for 40 min followed by reperfusion for 24 h. The renal damage induced by ischemia reperfusion injury (IRI) was assessed by measuring creatinine clearance, blood urea nitrogen, uric acid, plasma potassium, fractional excretion of sodium, and microproteinuria in rats. The oxidative stress in renal tissues was assessed by quantification of thiobarbituric acid-reactive substances, superoxide anion generation, and reduced glutathione level. The hematoxylin-eosin staining was carried out to observe histopathological changes in renal tissues. DYP (10 and 30 mg/kg, intraperitoneal, i.p.) was administered 30 min before subjecting the rats to renal IRI. In separate groups, caffeine (50 mg/kg, i.p.), an adenosinergic A1 and A2A receptor antagonist was administered with and without DYP treatment before subjecting the rats to renal IRI. The ischemia reperfusion-induced AKI was demonstrated by significant changes in serum as well as urinary parameters, enhanced oxidative stress, and histopathological changes in renal tissues. The administration of DYP demonstrated protection against AKI. The prior treatment with caffeine abolished DYP-mediated reno-protection suggesting role of A1 and A2A adenosine receptors in DYP-mediated reno-protection in rats. It is concluded that adenosine receptors find their definite involvement in DYP-mediated anti-oxidative and reno-protective effect against ischemia reperfusion-induced AKI.

  10. Optical coherence tomography angiography in paracentral acute middle maculopathy secondary to central retinal vein occlusion.

    PubMed

    Casalino, G; Williams, M; McAvoy, C; Bandello, F; Chakravarthy, U

    2016-06-01

    PurposeTo report the clinical course and the optical coherence tomography angiography (OCTA) findings of patients presenting with paracentral acute middle maculopathy (PAMM) and central retinal vein occlusion (CRVO).MethodsRetrospective case series. Clincal records and multimodal imaging findings of patients presenting with PAMM and CRVO were reviewed.ResultsThree eyes of three patients (2 males; mean age: 66 years) were included in the study. Mean follow-up was 9 months and images using OCTA (AngioVue OCT angiography system, Optovue, Inc., Fremont, CA, USA) were available at the last follow-up visit. During follow-up, best corrected visual acuity (BCVA) of case 1 was unchanged at 85 ETDRS letters and OCTA revealed a mild attenuation of the perifoveal deep capillary plexus (DCP); in case 2, BCVA changed from 83 to 77 ETDRS letters and OCTA revealed patchy areas of attenuation and pruning of the DCP; in case 3, BCVA decreased from 26 to 8 ETDRS letters and OCTA revealed extensive areas of DCP dropout.ConclusionThe natural course of visual acuity in patients with PAMM secondary to CRVO may vary. In these patients, the extent of DCP dropout on OCTA may reflect the extent of visual acuity impairment.

  11. Acute retinal necrosis in the United Kingdom: results of a prospective surveillance study

    PubMed Central

    Cochrane, T F; Silvestri, G; McDowell, C; Foot, B; McAvoy, C E

    2012-01-01

    Background To determine the incidence of acute retinal necrosis (ARN) in the United Kingdom and to describe the demographics, management, and visual outcome in these patients. Methods This was a prospective study carried out by the British Ophthalmological Surveillance Unit (BOSU) between September 2007 and October 2008. Initial and 6-month questionnaires were sent to UK ophthalmologists who reported cases of ARN via the monthly BOSU report card system. Results In all, 45 confirmed cases (52 eyes) of ARN were reported in the 14-month study period, giving a minimum incidence of 0.63 cases per million population per year. There were 20 females and 25 males. Age ranged from 10 to 94 years. Eight patients had a history of herpetic CNS disease. Aqueous sampling was carried out in 13 patients, vitreous in 27, and cerebrospinal fluid (CSF) in 4. Varicella-zoster virus followed by herpes simplex were the most common causative agents. Treatment in 76% of the cases was with intravenous antivirals; however, 24% received only oral antivirals. In all, 47% of patients had intravitreal antiviral therapy. Visual outcome at 6 months was <6/60 in 48% of the affected eyes. Conclusion The minimum incidence of ARN in the UK is 0.63 cases per million. Patients with a history of herpetic CNS disease should be warned to immediately report any visual symptoms. There is increased use of oral and intravitreal antivirals in initial treatment. PMID:22281865

  12. Acute impairment of saccadic eye movements is associated with delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

    PubMed

    Rowland, Matthew J; Garry, Payashi; Westbrook, Jon; Corkill, Rufus; Antoniades, Chrystalina A; Pattinson, Kyle T S

    2016-12-09

    OBJECTIVE Delayed cerebral ischemia (DCI) causing cerebral infarction remains a significant cause of morbidity and mortality following aneurysmal subarachnoid hemorrhage (aSAH). Early brain injury in the first 72 hours following rupture is likely to play a key role in the pathophysiology underlying DCI but remains difficult to quantify objectively. Current diagnostic modalities are based on the concept of vasoconstriction causing cerebral ischemia and infarction and are either invasive or have a steep learning curve and user variability. The authors sought to determine whether saccadic eye movements are impaired following aSAH and whether this measurement in the acute period is associated with the likelihood of developing DCI. METHODS As part of a prospective, observational cohort study, 24 male and female patients (mean age 53 years old, range 31-70 years old) were recruited. Inclusion criteria included presentation with World Federation of Neurosurgical Societies (WFNS) Grades 1 or 2 ("good grade") aSAH on admission and endovascular treatment within 72 hours of aneurysmal rupture. DCI and DCI-related cerebral infarction were defined according to consensus guidelines. Saccadometry data were collected at 3 time points in patients: in the first 72 hours, between Days 5 and 10, and at 3 months after aSAH. Data from 10 healthy controls was collected on 1 occasion for comparison. RESULTS Age-adjusted saccadic latency in patients was significantly prolonged in the first 72 hours following aSAH when compared with controls (188.7 msec [95% CI 176.9-202.2 msec] vs 160.7 msec [95% CI 145.6-179.4 msec], respectively; p = 0.0054, t-test). By 3 months after aSAH, there was no significant difference in median saccadic latency compared with controls (188.7 msec [95% CI 176.9-202.2 msec] vs 180.0 msec [95% CI 165.1-197.8 msec], respectively; p = 0.4175, t-test). Patients diagnosed with cerebral infarction due to DCI had a significantly higher age-adjusted saccadic latency in the

  13. The ILAILL Study: Iloprost as Adjuvant to Surgery for Acute Ischemia of Lower Limbs

    PubMed Central

    de Donato, Gaetano; Gussoni, Gualberto; de Donato, Gianmarco; Andreozzi, Giuseppe Maria; Bonizzoni, Erminio; Mazzone, Antonino; Odero, Attilio; Paroni, Giovanni; Setacci, Carlo; Settembrini, Piergiorgio; Veglia, Fabrizio; Martini, Romeo; Setacci, Francesco; Palombo, Domenico

    2006-01-01

    Summary Background Data: High rate of complications has been reported following revascularization for acute limb ischemia (ALI). No adjuvant pharmacologic treatment, apart from anticoagulation and standard perioperative care, has been shown clinically effective. Objective: Aim of this study was to evaluate the effects of the prostacyclin analog iloprost as adjuvant to surgery for ALI. Methods: A total of 300 patients were randomly assigned to receive perioperative iloprost (intra-arterial, intraoperative bolus of 3000 ng, plus intravenous infusion of 0.5–2.0 ng/kg/min for 6 hours/day for 4–7 days following surgery), or placebo. The primary endpoint was the combined incidence of death and amputation at 3-month follow-up. Secondary endpoints were the incidence of each single major complication, total event rate, symptomatology, and tolerability. Results: The combined incidence of death and amputation was 19.9% in the placebo and 14.1% in the iloprost group (relative risk, 1.56; 95% confidence interval, 0.89–2.75, P = 0.12, Cox regression analysis). A statistically significant lower mortality (4.7%) was reported in patients receiving iloprost, compared with controls (10.6%; relative risk, 2.61; 95% confidence interval, 1.07–6.37, P = 0.03). The overall incidence of fatal plus major cardiovascular events was 33.1% and 22.8% in placebo and iloprost groups, respectively (relative risk, 1.61; 95% confidence interval, 1.04–2.49, P = 0.03). No serious adverse reactions occurred after iloprost administration, nor differences in the incidence of bleeding or hypotension between treatment groups. Conclusions: Although at lower levels than previously reported, our results confirm the severity of ALI. Iloprost as adjuvant to surgery significantly reduced mortality and overall major event rate. Further data are needed to support this finding, and to face a still open medical issue. PMID:16858180

  14. Radial forearm free flap morbidity: A rare case of a normal preoperative arteriogram and acute intraoperative hand ischemia.

    PubMed

    Bruner, Terrence W; Hanasono, Matthew M; Skoracki, Roman J

    2011-01-01

    Since its first description in 1981, the radial forearm free flap has become a valuable tool for reconstructive microsurgery. However, there are potential complications associated with the flap - the most feared being hand ischemia from sacrifice of the radial artery. Fortunately, acute ischemic complications are exceedingly rare, with only two cases reported in the literature. Options for preoperative evaluation of the donor extremity include the Allen's test, ultrasonography and angiography. A preoperative arteriogram is considered to be the definitive method to evaluate arterial anatomy, patency, and collateralization between the radial and ulnar arteries. The current article presents the authors' experience with a patient who had a delayed Allen's test and a normal arteriogram of his left upper extremity, and who developed acute intraoperative hand ischemia, requiring reconstruction of his radial artery, after elevation of a radial forearm free flap.Although exceedingly rare, the occurrence of acute vascular insufficiency is always a possibility and must be kept in mind when harvesting a radial forearm free flap. The surgeon should be prepared to perform an interposition vein graft reconstruction to avoid any potential complications. Clinical examination and judgment may be more important than radiological studies in certain cases.

  15. Sigma-1 receptor stimulation protects retinal ganglion cells from ischemia-like insult through the activation of extracellular-signal-regulated kinases 1/2.

    PubMed

    Mueller, Brett H; Park, Yong; Ma, Hai-Ying; Dibas, Adnan; Ellis, Dorette Z; Clark, Abbot F; Yorio, Thomas

    2014-11-01

    Sigma-1 receptor (σ-1) activation and mitogen-activated protein kinases (MAPKs) have been shown to protect retinal ganglion cells (RGCs) from cell death. The purpose of this study was to determine if σ-1 receptor stimulation with pentazocine could promote neuroprotection under conditions of an ischemia-like insult (oxygen glucose deprivation (OGD)) through the phosphorylation of extracellular signal regulated kinase (pERK)1/2. Primary RGCs were isolated from P3-P7 Sprague-Dawley rats and purified by sequential immunopanning using Thy1.1 antibodies. RGCs were cultured for 7 days before subjecting the cells to an OGD insult (0.5% oxygen in glucose-free medium) for 6 h. During the OGD, RGCs were treated with pentazocine (σ-1 receptor agonist) with or without BD 1047 (σ-1 receptor antagonist). In other experiments, primary RGCs were treated with pentazocine in the presence or absence of an MEK1/2 inhibitor, PD098059. Cell survival/death was assessed by staining with the calcein-AM/ethidium homodimer reagent. Levels of pERK1/2, total ERK1/2, and beta tubulin expression were determined by immunoblotting and immunofluorescence staining. RGCs subjected to OGD for 6 h induced 50% cell death in primary RGCs (p < 0.001) and inhibited pERK1/2 expression by 65% (p < 0.001). Cell death was attenuated when RGCs were treated with pentazocine under OGD (p < 0.001) and pERK1/2 expression was increased by 1.6 fold (p < 0.05) compared to OGD treated RGCs without pentazocine treatment. The co-treatment of PD098059 (MEK1/2 inhibitor) with pentazocine significantly abolished the protective effects of pentazocine on the RGCs during this OGD insult. Activation of the σ-1 receptor is a neuroprotective target that can protect RGCs from an ischemia-like insult. These results also established a direct relationship between σ-1 receptor stimulation and the neuroprotective effects of the ERK1/2 pathway in purified RGCs subjected to OGD. These findings suggest that activation of

  16. [Application of retinal oximeter in ophthalmology].

    PubMed

    Li, Jing; Ma, Jianmin; Wang, Ningli

    2015-11-01

    Retinal oximeter is a new machine which has been used in the diagnose, treatment and research of several ophthalmic diseases for recent years. It allows ophthalmologists to gain retinal oxygen saturation directly. Therefore, retinal oximeter might be useful for ophthalmologists to understand ophthalmic diseases more deeper and clarify the impact of ischemia on retinal function. It has been reported in the literatures that retinal oximeter has potentially useful diagnostic and therapeutic indications in various eye diseases such as diabetic retinopathy, central retinal vein and artery occlusion, retinitis pigmentosa, glaucomatous optic neuropathy, et al. In this thesis, the application of retinal oximeter in ophthalmology is reviewed.

  17. In Vivo Imaging of Retinal Hypoxia in a Model of Oxygen-Induced Retinopathy

    PubMed Central

    Uddin, Md. Imam; Evans, Stephanie M.; Craft, Jason R.; Capozzi, Megan E.; McCollum, Gary W.; Yang, Rong; Marnett, Lawrence J.; Uddin, Md. Jashim; Jayagopal, Ashwath; Penn, John S.

    2016-01-01

    Ischemia-induced hypoxia elicits retinal neovascularization and is a major component of several blinding retinopathies such as retinopathy of prematurity (ROP), diabetic retinopathy (DR) and retinal vein occlusion (RVO). Currently, noninvasive imaging techniques capable of detecting and monitoring retinal hypoxia in living systems do not exist. Such techniques would greatly clarify the role of hypoxia in experimental and human retinal neovascular pathogenesis. In this study, we developed and characterized HYPOX-4, a fluorescence-imaging probe capable of detecting retinal-hypoxia in living animals. HYPOX-4 dependent in vivo and ex vivo imaging of hypoxia was tested in a mouse model of oxygen-induced retinopathy (OIR). Predicted patterns of retinal hypoxia were imaged by HYPOX-4 dependent fluorescence activity in this animal model. In retinal cells and mouse retinal tissue, pimonidazole-adduct immunostaining confirmed the hypoxia selectivity of HYPOX-4. HYPOX-4 had no effect on retinal cell proliferation as indicated by BrdU assay and exhibited no acute toxicity in retinal tissue as indicated by TUNEL assay and electroretinography (ERG) analysis. Therefore, HYPOX-4 could potentially serve as the basis for in vivo fluorescence-based hypoxia-imaging techniques, providing a tool for investigators to understand the pathogenesis of ischemic retinopathies and for physicians to address unmet clinical needs. PMID:27491345

  18. Acute Left Arm Ischemia Associated with Floating Thrombus in the Proximal Descending Aorta: Combined Endovascular and Surgical Therapy

    SciTech Connect

    Fanelli, F.; Gazzetti, M.; Boatta, E.; Ruggiero, M.; Lucatelli, P.; Speziale, F.

    2011-02-15

    Free floating thrombus in the proximal descending aorta is an uncommon and dangerous condition that can be associated with acute peripheral embolization. The few cases described were solved with surgical and/or medical therapy. We report the case of a patient with acute left arm ischemia secondary to the presence of floating thrombus in the proximal descending aorta extending into the left subclavian artery, solved with combined endovascular and surgical therapy. Treatment was successfully performed with thrombembolectomy combined with temporary deployment, into the descending aorta, of a Wallstent in a 'basket-fashion' to avoid distal embolization secondary to thrombus fragmentation. At 1 year follow-up the patient remained symptom-free.

  19. Acute estradiol protects CA1 neurons from ischemia-induced apoptotic cell death via the PI3K/Akt pathway

    PubMed Central

    Jover-Mengual, Teresa; Miyawaki, Takahiro; Latuszek, Adrianna; Alborch, Enrique; Zukin, R. Suzanne; Etgen, Anne M.

    2010-01-01

    Global ischemia arising during cardiac arrest or cardiac surgery causes highly selective, delayed death of hippocampal CA1 neurons. Exogenous estradiol ameliorates global ischemia-induced neuronal death and cognitive impairment in male and female rodents. However, the molecular mechanisms by which a single acute injection of estradiol administered after the ischemic event intervenes in global ischemia-induced apoptotic cell death are unclear. Here we show that acute estradiol acts via the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling cascade to protect CA1 neurons in ovariectomized female rats. We demonstrate that global ischemia promotes early activation of glycogen synthase kinase-3β (GSK3β) and forkhead transcription factor of the O class (FOXO)3A, known Akt targets that are related to cell survival, and activation of caspase-3. Estradiol prevents ischemia-induced dephosphorylation and activation of GSK3β and FOXO3A, and the caspase death cascade. These findings support a model whereby estradiol acts by activation of PI3K/Akt signaling to promote neuronal survival in the face of global ischemia. PMID:20114038

  20. Adenosine A2A Receptors Modulate Acute Injury and Neuroinflammation in Brain Ischemia

    PubMed Central

    Pedata, Felicita; Pugliese, Anna Maria; Coppi, Elisabetta; Dettori, Ilaria; Maraula, Giovanna; Cellai, Lucrezia; Melani, Alessia

    2014-01-01

    The extracellular concentration of adenosine in the brain increases dramatically during ischemia. Adenosine A2A receptor is expressed in neurons and glial cells and in inflammatory cells (lymphocytes and granulocytes). Recently, adenosine A2A receptor emerged as a potential therapeutic attractive target in ischemia. Ischemia is a multifactorial pathology characterized by different events evolving in the time. After ischemia the early massive increase of extracellular glutamate is followed by activation of resident immune cells, that is, microglia, and production or activation of inflammation mediators. Proinflammatory cytokines, which upregulate cell adhesion molecules, exert an important role in promoting recruitment of leukocytes that in turn promote expansion of the inflammatory response in ischemic tissue. Protracted neuroinflammation is now recognized as the predominant mechanism of secondary brain injury progression. A2A receptors present on central cells and on blood cells account for important effects depending on the time-related evolution of the pathological condition. Evidence suggests that A2A receptor antagonists provide early protection via centrally mediated control of excessive excitotoxicity, while A2A receptor agonists provide protracted protection by controlling massive blood cell infiltration in the hours and days after ischemia. Focus on inflammatory responses provides for adenosine A2A receptor agonists a wide therapeutic time-window of hours and even days after stroke. PMID:25165414

  1. Extract of grapefruit-seed reduces acute pancreatitis induced by ischemia/reperfusion in rats: possible implication of tissue antioxidants.

    PubMed

    Dembinski, A; Warzecha, Z; Konturek, S J; Ceranowicz, P; Dembinski, M; Pawlik, W W; Kusnierz-Cabala, B; Naskalski, J W

    2004-12-01

    Grapefruit seed extract (GSE) has been shown to exert antibacterial, antifungal and antioxidant activity possibly due to the presence of naringenin, the flavonoid with cytoprotective action on the gastric mucosa. No study so far has been undertaken to determine whether this GSE is also capable of preventing acute pancreatic damage induced by ischemia/reperfusion (I/R), which is known to result from reduction of anti-oxidative capability of pancreatic tissue, and whether its possible preventive effect involves an antioxidative action of this biocomponent. In this study carried out on rats with acute hemorrhagic pancreatitis induced by 30 min partial pancreatic ischemia followed by 6 h of reperfusion, the GSE or vehicle (vegetable glycerin) was applied intragastrically in gradually increasing amounts (50-500 microl) 30 min before I/R. Pretreatment with GSE decreased the extent of pancreatitis with maximal protective effect of GSE at the dose 250 microl. GSE reduced the pancreatitis-evoked increase in serum lipase and poly-C specific ribonuclease activity, and attenuated the marked fall in pancreatic blood flow and pancreatic DNA synthesis. GSE administered alone increased significantly pancreatic tissue content of lipid peroxidation products, malondialdehyde and 4-hydroxyalkens, and when administered before I/R, GSE reduced the pancreatitis-induced lipid peroxidation. We conclude that GSE exerts protective activity against I/R-induced pancreatitis probably due to the activation of antioxidative mechanisms in the pancreas and the improvement of pancreatic blood flow.

  2. Case Report of Percutaneous Retrograde Transcollateral Recanalization of the Superior Mesenteric Artery via the Celiac Artery for Acute Mesenteric Ischemia

    PubMed Central

    Gupta, Prateek K.; Smith, Brigitte K.; Yamanouchi, Dai

    2015-01-01

    Abstract Revascularization for acute mesenteric ischemia (AMI) can be achieved through a bypass from the aorta or iliac arteries, embolectomy, open exposure of SMA and retrograde recanalization and stent, or percutaneous antegrade stenting. Flush occlusion of the SMA can make antegrade recanalization very challenging and is usually unsuccessful. We present a novel approach for recanalization of superior mesenteric artery (SMA) via the celiac artery for acute mesenteric ischemia. A 69-year-old lady with previous endarterectomy of SMA and extensive small bowel resection presented with severe abdominal pain, emesis, leukocytosis, and imaging finding of new SMA flush occlusion. She refused to consent for a laparotomy. Percutaneous retrograde transcollateral recanalization of SMA was performed via the celiac artery through the pancreaticoduodenal arcade, and the SMA then stented. This resulted in subsequent resolution of patient's symptoms and discharge. SMA revascularization with retrograde transcollateral wiring technique is an important tool in the armamentarium of the vascular care specialist when antegrade percutaneous approach and open exposure via laparotomy are not an option. PMID:26683911

  3. Clinical characteristics of silent myocardial ischemia diagnosed with adenosine stress 99mTc-tetrofosmin myocardial scintigraphy in Japanese patients with acute cerebral infarction.

    PubMed

    Nomura, Tetsuya; Kusaba, Tetsuro; Kodama, Naotoshi; Terada, Kensuke; Urakabe, Yota; Nishikawa, Susumu; Keira, Natsuya; Matsubara, Hiroaki; Tatsumi, Tetsuya

    2013-01-01

    It is well known that silent myocardial ischemia (SMI) often complicates patients with cerebral infarction and that stroke patients often die of ischemic heart disease. Therefore, it is considered important to treat myocardial ischemia in stroke patients. This study investigated SMI complicating Japanese patients with fresh stroke, using (99m)Tc-tetrofosmin myocardial scintigraphy with pharmacologic stress testing to elucidate their clinical manifestations. This study included 41 patients (26 men, mean age 76.0 ± 10.7 years) with acute cerebral infarction and no history of coronary artery disease. All patients underwent (99m)Tc-tetrofosmin myocardial scintigraphy with intravenous administration of adenosine to diagnose SMI. Of the 41 patients, myocardial ischemia was confirmed in 17 patients (41.5%). Atherosclerotic etiology was the major cause of stroke in the ischemia(+) group and embolic origin was the major cause in the ischemia(-) group. Patients with myocardial ischemia had a higher incidence of diabetes mellitus (52.9 vs 20.8%; P = 0.0323) and more than two conventional cardiovascular risk factors (64.7 vs 25.0%; P = 0.0110) compared with the nonischemic patients. Infarction subtype of atherosclerotic origin was an independent positive predictor of asymptomatic myocardial ischemia in patients with stroke. These findings indicate that the prevalence of asymptomatic myocardial ischemia is relatively high, especially in patients with stroke of atherosclerotic origin. Therefore, it is beneficial for us to narrow the target population who are at the highest risk when screening for SMI in Japanese patients with acute cerebral infarction.

  4. Acute Stroke and Limb Ischemia Secondary to Catastrophic Massive Intracardiac Thrombus in a 40-Year-Old Patient With Dilated Cardiomyopathy

    PubMed Central

    Jeon, Gi Jung; Song, Bong Gun; Park, Yong Hwan; Kang, Gu Hyun; Chun, Woo Jung; Oh, Ju Hyeon

    2012-01-01

    Dilated cardiomyopathy has been associated with left ventricular (LV) thrombosis which leads to substantial morbidity and mortality as a site for systemic emboli. We report an interesting case of a stroke and acute limb ischemia secondary to a large mobile pedunculated LV thrombus in 40-year-old patient with dilated cardiomyopathy.

  5. Effects of acute versus post-acute systemic delivery of neural progenitor cells on neurological recovery and brain remodeling after focal cerebral ischemia in mice.

    PubMed

    Doeppner, T R; Kaltwasser, B; Teli, M K; Bretschneider, E; Bähr, M; Hermann, D M

    2014-08-21

    Intravenous transplantation of neural progenitor cells (NPCs) induces functional recovery after stroke, albeit grafted cells are not integrated into residing neural networks. However, a systematic analysis of intravenous NPC delivery at acute and post-acute time points and their long-term consequences does not exist. Male C57BL6 mice were exposed to cerebral ischemia, and NPCs were intravenously grafted on day 0, on day 1 or on day 28. Animals were allowed to survive for up to 84 days. Mice and tissues were used for immunohistochemical analysis, flow cytometry, ELISA and behavioral tests. Density of grafted NPCs within the ischemic hemisphere was increased when cells were transplanted on day 28 as compared with transplantation on days 0 or 1. Likewise, transplantation on day 28 yielded enhanced neuronal differentiation rates of grafted cells. Post-ischemic brain injury, however, was only reduced when NPCs were grafted at acute time points. On the contrary, reduced post-ischemic functional deficits due to NPC delivery were independent of transplantation paradigms. NPC-induced neuroprotection after acute cell delivery was due to stabilization of the blood-brain barrier (BBB), reduction in microglial activation and modulation of both peripheral and central immune responses. On the other hand, post-acute NPC transplantation stimulated post-ischemic regeneration via enhanced angioneurogenesis and increased axonal plasticity. Acute NPC delivery yields long-term neuroprotection via enhanced BBB integrity and modulation of post-ischemic immune responses, whereas post-acute NPC delivery increases post-ischemic angioneurogenesis and axonal plasticity. Post-ischemic functional recovery, however, is independent of NPC delivery timing, which offers a broad therapeutic time window for stroke treatment.

  6. Ischemic Tissue Injury in the Dorsal Skinfold Chamber of the Mouse: A Skin Flap Model to Investigate Acute Persistent Ischemia

    PubMed Central

    Harder, Yves; Schmauss, Daniel; Wettstein, Reto; Egaña, José T.; Weiss, Fabian; Weinzierl, Andrea; Schuldt, Anna; Machens, Hans-Günther; Menger, Michael D.; Rezaeian, Farid

    2014-01-01

    Despite profound expertise and advanced surgical techniques, ischemia-induced complications ranging from wound breakdown to extensive tissue necrosis are still occurring, particularly in reconstructive flap surgery. Multiple experimental flap models have been developed to analyze underlying causes and mechanisms and to investigate treatment strategies to prevent ischemic complications. The limiting factor of most models is the lacking possibility to directly and repetitively visualize microvascular architecture and hemodynamics. The goal of the protocol was to present a well-established mouse model affiliating these before mentioned lacking elements. Harder et al. have developed a model of a musculocutaneous flap with a random perfusion pattern that undergoes acute persistent ischemia and results in ~50% necrosis after 10 days if kept untreated. With the aid of intravital epi-fluorescence microscopy, this chamber model allows repetitive visualization of morphology and hemodynamics in different regions of interest over time. Associated processes such as apoptosis, inflammation, microvascular leakage and angiogenesis can be investigated and correlated to immunohistochemical and molecular protein assays. To date, the model has proven feasibility and reproducibility in several published experimental studies investigating the effect of pre-, peri- and postconditioning of ischemically challenged tissue. PMID:25489743

  7. Retinitis Pigmentosa

    MedlinePlus

    ... Action You are here Home › Retinal Diseases Listen Retinitis Pigmentosa What is retinitis pigmentosa? What are the symptoms? ... is available? What treatment is available? What is retinitis pigmentosa? Retinitis pigmentosa, also known as RP, refers to ...

  8. Inhibition of Angiotensin-II Production Increases Susceptibility to Acute Ischemia/Reperfusion Arrhythmia

    PubMed Central

    Taskin, Eylem; Tuncer, Kadir Ali; Guven, Celal; Kaya, Salih Tunc; Dursun, Nurcan

    2016-01-01

    Background Myocardial ischemia and reperfusion lead to impairment of electrolyte balance and, eventually, lethal arrhythmias. The aim of this study was to investigate the effects of pharmacological inhibition of angiotensin-II (Ang-II) production on heart tissue with ischemia-reperfusion damage, arrhythmia, and oxidative stress. Material/Methods Rats were divided into 4 groups: only ischemia/reperfusion (MI/R), captopril (CAP), aliskiren (AL), and CAP+AL. The drugs were given by gavage 30 min before anesthesia. Blood pressure and electrocardiography (ECG) were recorded during MI/R procedures. The heart tissue and plasma was kept so as to evaluate the total oxidant (TOS), antioxidant status (TAS), and creatine kinase-MB (CK-MB). Results Creatine kinase-MB was not different among the groups. Although TAS was not affected by inhibition of Ang-II production, TOS was significantly lower in the CAP and/or AL groups than in the MI/R group. Furthermore, oxidative stress index was significantly attenuated in the CAP and/or AL groups. Captopril significantly increased the duration of VT during ischemia; however, it did not have any effect on the incidence of arrhythmias. During reperfusion periods, aliskiren and its combinations with captopril significantly reduced the incidence of other types of arrhythmias. Captopril alone had no effect on the incidence of arrhythmias, but significantly increased arrhythmias score and durations of arrhythmias during reperfusion. MAP and heart rate did not show changes in any groups during ischemic and reperfusion periods. Conclusions Angiotensin-II production appears to be associated with elevated levels of reactive oxygen species, but Ang-II inhibitions increases arrhythmia, mainly by initiating ventricular ectopic beats. PMID:27889788

  9. Neuroprotective Effects of Isosteviol Sodium Injection on Acute Focal Cerebral Ischemia in Rats

    PubMed Central

    Hu, Hui; Sun, Xiao ou; Tian, Fang; Zhang, Hao; Liu, Qing; Tan, Wen

    2016-01-01

    Previous report has indicated that isosteviol has neuroprotective effects. However, isosteviol was administered preventively before ischemia and the inclusion criteria were limited. In the present study, a more soluble and injectable form of isosteviol sodium (STVNA) was administered intravenously hours after transient or permanent middle cerebral artery occlusion (tMCAO or pMCAO) to investigate its neuroprotective effects in rats. The rats were assessed for neurobehavioral deficits 24 hours after ischemia and sacrificed for infarct volume quantification and histology evaluation. STVNA 10 mg·kg−1 can significantly reduce the infarct volumes compared with vehicle in animals subjected to tMCAO and is twice as potent as previously reported. Additionally, the therapeutic window study showed that STVNA could reduce the infarct volume compared with the vehicle group when administered 4 hours after reperfusion. A similar effect was also observed in animals treated 4 hours after pMCAO. Assessment of neurobehavioral deficits after 24 hours showed that STVNA treatment significantly reduced neurobehavioral impairments. The number of restored NeuN-labeled neurons was increased and the number of TUNEL positive cells was reduced in animals that received STVNA treatment compared with vehicle group. All of these findings suggest that STVNA might provide therapeutic benefits against cerebral ischemia-induced injury. PMID:27047634

  10. Emergent Treatment of Acute Embolic Superior Mesenteric Ischemia with Combination of Thrombolysis and Angioplasty: Report of Two Cases

    SciTech Connect

    Wakabayashi, H. Shiode, Tsuyoki; Kurose, Michihiro; Moritani, Hiroki; Fujiki, Shigeatsu; Morimoto, Naoki; Kusachi, Shozo

    2004-08-15

    We successfully revascularized the acutely occluded superior mesenteric artery (SMA), caused by a thromboembolus, with a combination of thrombolysis and percutaneous transluminal angioplasty (PTA) in 2 patients. Considerable percent luminal reduction (>90%) was still observed after thrombolysis in both patients. Subsequent adjunctive balloon angioplasty produced sufficient luminal diameter of the SMA (<20% luminal reduction). No serious acute procedural complication occurred. The time from onset to partial reperfusion by thrombolysis was approximately 4.5 and 5.5 hours. Approximately 1 week after the combination therapy, colonoscopy and a small bowel radiocontrast series showed localized mucosal ischemia with mild erosions and ulcerations in the terminal ileum and ascending colon in 1 patient. Subsequent bowel resection was required but the resection was short (<20 cm). The other patient's bowel condition was good and did not require any surgical treatment. The present cases suggest that combination therapy is useful for achieving rapid and sufficient revascularization of acute proximal thromboembolic SMA occlusion, and prevents the considerably broad bowel necrosis that requires surgical bowel resection, resulting in short bowel syndrome.

  11. Protective effect of Xuebijing injection against acute lung injury induced by left ventricular ischemia/reperfusion in rabbits

    PubMed Central

    JI, MINGLI; WANG, YUXIA; WANG, LEI; CHEN, LIPING; LI, JING

    2016-01-01

    Xuebijing (XBJ) is a Chinese herbal preparation. Previous studies have demonstrated that XBJ injection is able to inhibit the uncontrolled release of endogenous inflammatory mediators, attenuate inflammation, and alleviate organ damage. However, there are no relevant reports on the protective effect of XBJ against left ventricular ischemia/reperfusion (I/R)-induced acute lung injury (ALI). Therefore, the aim of the present study was to evaluate the protective effect of XBJ on ALI induced by left ventricular I/R, and provide evidence for the clinical application of XBJ. In the present study, 120 healthy rabbits of mixed gender were randomly assigned to a normal control group, ischemia group, I/R group (I/RG) and XBJ-injection treatment group (TG). In addition, each group was further divided into three subgroups (n=10/subgroup), namely, 30 min pre-ischemia, 30 min post-ischemia and 30 min post-reperfusion subgroups. Blood samples (5 ml) were collected from the jugularis externa and carotis communis of the rabbits at the three time points, and a blood gas analyzer was used to measure the arterial partial pressure of oxygen (PaO2) and carbon dioxide (PaCO2). Following sacrifice, the lungs of the rabbits were removed and a bronchoalveolar lavage (BAL) was immediately performed. An enzyme-linked immunosorbent assay was used to measure the expression levels of tumor necrosis factor-α (TNF-α) in the BAL fluid (BALF) and peripheral blood. In addition, the lower lobe of the right lung was removed in order to measure the protein expression levels of intercellular adhesion molecule-1 (ICAM-1) and TNF-α. The results demonstrated that in the rabbits of the TG PaO2 was increased, PaCO2 was decreased, the lung tissue congestion edema was attenuated, the expression levels of TNF-α in the peripheral blood and BALF were reduced and the protein expression levels of ICAM-1 and TNF-α in the lung tissue samples were decreased, as compared with those in the I/RG rabbits. These

  12. Preconditioning with Triiodothyronine Improves the Clinical Signs and Acute Tubular Necrosis Induced by Ischemia/Reperfusion in Rats

    PubMed Central

    Ferreyra, Carla; Vargas, Félix; Rodríguez-Gómez, Isabel; Pérez-Abud, Rocío; O'Valle, Francisco; Osuna, Antonio

    2013-01-01

    Background Renal ischemia/reperfusion (I/R) injury is manifested by acute renal failure (ARF) and acute tubular necrosis (ATN). The aim of this study was to evaluate the effectiveness of preconditioning with 3, 3, 5 triiodothyronine (T3) to prevent I/R renal injury. Methodology/Principal Findings The rats were divided into four groups: sham-operated, placebo-treated (SO-P), sham-operated T3- treated (SO- T3), I/R-injured placebo-treated (IR-P), and I/R-injured T3-treated (IR- T3) groups. At 24 h before ischemia, the animals received a single dose of T3 (100 μg/kg). Renal function and plasma, urinary, and tissue variables were studied at 4, 24, and 48 h of reperfusion, including biochemical, oxidative stress, and inflammation variables, PARP-1 immunohistochemical expression, and ATN morphology. In comparison to the SO groups, the IR-P groups had higher plasma urea and creatinine levels and greater proteinuria (at all reperfusion times) and also showed: increased oxidative stress-related plasma, urinary, and tissue variables; higher plasma levels of IL6 (proinflammatory cytokine); increased glomerular and tubular nuclear PARP-1 expression; and a greater degree of ATN. The IR-T3 group showed a marked reduction in all of these variables, especially at 48 h of reperfusion. No significant differences were observed between SO-P and SO-T3 groups. Conclusions This study demonstrates that preconditioning rats with a single dose of T3 improves the clinical signs and ATN of renal I/R injury. These beneficial effects are accompanied by reductions in oxidative stress, inflammation, and renal PARP-1 expression, indicating that this sequence of factors plays an important role in the ATN induced by I/R injury. PMID:24086411

  13. The TRIF-dependent signaling pathway is not required for acute cerebral ischemia/reperfusion injury in mice

    SciTech Connect

    Hua, Fang; Wang, Jun; Sayeed, Iqbal; Ishrat, Tauheed; Atif, Fahim; Stein, Donald G.

    2009-12-18

    TIR domain-containing adaptor protein (TRIF) is an adaptor protein in Toll-like receptor (TLR) signaling pathways. Activation of TRIF leads to the activation of interferon regulatory factor 3 (IRF3) and nuclear factor kappa B (NF-{kappa}B). While studies have shown that TLRs are implicated in cerebral ischemia/reperfusion (I/R) injury and in neuroprotection against ischemia afforded by preconditioning, little is known about TRIF's role in the pathological process following cerebral I/R. The present study investigated the role that TRIF may play in acute cerebral I/R injury. In a mouse model of cerebral I/R induced by transient middle cerebral artery occlusion, we examined the activation of NF-{kappa}B and IRF3 signaling in ischemic cerebral tissue using ELISA and Western blots. Neurological function and cerebral infarct size were also evaluated 24 h after cerebral I/R. NF-{kappa}B activity and phosphorylation of the inhibitor of kappa B (I{kappa}B{alpha}) increased in ischemic brains, but IRF3, inhibitor of {kappa}B kinase complex-{epsilon} (IKK{epsilon}), and TANK-binding kinase1 (TBK1) were not activated after cerebral I/R in wild-type (WT) mice. Interestingly, TRIF deficit did not inhibit NF-{kappa}B activity or p-I{kappa}B{alpha} induced by cerebral I/R. Moreover, although cerebral I/R induced neurological and functional impairments and brain infarction in WT mice, the deficits were not improved and brain infarct size was not reduced in TRIF knockout mice compared to WT mice. Our results demonstrate that the TRIF-dependent signaling pathway is not required for the activation of NF-{kappa}B signaling and brain injury after acute cerebral I/R.

  14. Successful Endovascular Repair of an Iatrogenic Perforation of the Superficial Femoral Artery Using Self-Expanding Nitinol Supera Stents in a Patient with Acute Thromboembolic Limb Ischemia.

    PubMed

    Eisele, Tom; Muenz, Benedikt M; Korosoglou, Grigorios

    2016-01-01

    The treatment of acute thromboembolic limb ischemia includes well-established surgical thrombectomy procedures and, in recent times, also percutaneous rotational thrombectomy using Straub Rotarex® system. This modality not only enables efficient treatment of such thrombotic occlusion but also in rare cases may imply the risk of perforation of the occluded artery. Herein, we report the case of a perforation of the superficial femoral artery (SFA) in an elderly female patient with thromboembolic limb ischemia. The perforation was successfully treated by implantation of self-expanding nitinol Supera stents and without the need for implantation of a stent graft.

  15. Successful Endovascular Repair of an Iatrogenic Perforation of the Superficial Femoral Artery Using Self-Expanding Nitinol Supera Stents in a Patient with Acute Thromboembolic Limb Ischemia

    PubMed Central

    Eisele, Tom; Muenz, Benedikt M.

    2016-01-01

    The treatment of acute thromboembolic limb ischemia includes well-established surgical thrombectomy procedures and, in recent times, also percutaneous rotational thrombectomy using Straub Rotarex® system. This modality not only enables efficient treatment of such thrombotic occlusion but also in rare cases may imply the risk of perforation of the occluded artery. Herein, we report the case of a perforation of the superficial femoral artery (SFA) in an elderly female patient with thromboembolic limb ischemia. The perforation was successfully treated by implantation of self-expanding nitinol Supera stents and without the need for implantation of a stent graft. PMID:27213074

  16. Effects of resting ischemia assessed by thallium scintigraphy on QRS scoring system for estimating left ventricular function quantified by radionuclide angiography in acute myocardial infarction patients.

    PubMed

    DePace, N L; Hakki, A H; Iskandrian, A S

    1984-06-01

    The purpose of this study was to determine whether resting ischemia limits the usefulness of the QRS scoring system in predicting left ventricular (LV) ejection fraction (EF) in patients with acute infarction. We studied 48 patients after acute infarction by means of 12-lead ECG, thallium-201 scintigraphy, and radionuclide angiography. The thallium-201 scintigrams showed fixed defects in 25 patients, perfusion defects with partial or complete redistribution in the delayed images in 19 patients, and normal images in the remaining four patients. In the 48 patients there was a significant correlation between the QRS score and LVEF (r = -0.67; p less than 0.001). Patients with fixed defects showed a better correlation than patients with resting ischemia (r = -0.77 vs r = -0.60). A QRS score of 3 or less was used to separate patients with LVEF of 40% or greater from those with lower LVEF in patients with fixed defects (p = 0.0005), but this cutoff did not categorize patients with resting ischemia as to LVEF. Thus the presence of rest ischemia in patients with acute infarction may affect the correlation between QRS score and LVEF.

  17. N-11C-Methyl-Dopamine PET Imaging of Sympathetic Nerve Injury in a Swine Model of Acute Myocardial Ischemia: A Comparison with 13N-Ammonia PET

    PubMed Central

    Zhou, Weina; Wang, Xiangcheng; He, Yulin; Nie, Yongzhen; Zhang, Guojian; Wang, Cheng; Wang, Chunmei; Wang, Xuemei

    2016-01-01

    Objective. Using a swine model of acute myocardial ischemia, we sought to validate N-11C-methyl-dopamine (11C-MDA) as an agent capable of imaging cardiac sympathetic nerve injury. Methods. Acute myocardial ischemia was surgically generated in Chinese minipigs. ECG and serum enzyme levels were used to detect the presence of myocardial ischemia. Paired 11C-MDA PET and 13N-ammonia PET scans were performed at baseline, 1 day, and 1, 3, and 6 months after surgery to relate cardiac sympathetic nerve injury to blood perfusion. Results. Seven survived the surgical procedure. The ECG-ST segment was depressed, and levels of the serum enzymes increased. Cardiac uptake of tracer was quantified as the defect volume. Both before and immediately after surgery, the images obtained with 11C-MDA and 13N-ammonia were similar. At 1 to 6 months after surgery, however, 11C-MDA postsurgical left ventricular myocardial defect volume was significantly greater compared to 13N-ammonia. Conclusions. In the Chinese minipig model of acute myocardial ischemia, the extent of the myocardial defect as visualized by 11C-MDA is much greater than would be suggested by blood perfusion images, and the recovery from myocardial sympathetic nerve injury is much slower than the restoration of blood perfusion. 11C-MDA PET may provide additional biological information during recovery from ischemic heart disease. PMID:27034950

  18. β-Dystroglycan cleavage by matrix metalloproteinase-2/-9 disturbs aquaporin-4 polarization and influences brain edema in acute cerebral ischemia.

    PubMed

    Yan, W; Zhao, X; Chen, H; Zhong, D; Jin, J; Qin, Q; Zhang, H; Ma, S; Li, G

    2016-06-21

    Dystroglycan (DG) is widely expressed in various tissues, and throughout the cerebral microvasculature. It consists of two subunits, α-DG and β-DG, and the cleavage of the latter by matrix metalloproteinase (MMP)-2 and -9 underlies a number of physiological and pathological processes. However, the involvement of MMP-2/-9-mediated β-DG cleavage in cerebral ischemia remains uncertain. In astrocytes, DG is crucial for maintaining the polarization of aquaporin-4 (AQP4), which plays a role in the regulation of cytotoxic and vasogenic edema. The present study aimed to explore the effects of MMP-2/-9-mediated β-DG cleavage on AQP4 polarization and brain edema in acute cerebral ischemia. A model of cerebral ischemia was established via permanent middle cerebral artery occlusion (pMCAO) in male C57BL/6 mice. Western blotting, real-time polymerase chain reaction (PCR), immunohistochemical staining, immunofluorescent staining, electron microscopy, and light microscopy were used. Captopril was applied as a selective MMP-2/-9 inhibitor. Recombinant mouse MMP (rmMMP)-2 and -9 were used in an in vitro cleavage experiment. The present study demonstrated evidence of β-DG cleavage by MMP-2/-9 in pMCAO mouse brains; this cleavage was implicated in AQP4 redistribution and brain edema in cerebral ischemia. In addition, captopril exacerbated cytotoxic edema and ameliorated vasogenic edema at 24h after pMCAO, and alleviated brain edema and neurological deficit at 48h and 72h. In conclusion, this study provides novel insight into the effects of MMP-2/-9-mediated β-DG cleavage in acute cerebral ischemia. Such findings might facilitate the development of a therapeutic strategy for the optimization of MMP-2/-9 targeted treatment in cerebral ischemia.

  19. Reticulocyte count is the most important predictor of acute cerebral ischemia and high-risk transcranial Doppler in a newborn cohort of 395 children with sickle cell anemia.

    PubMed

    Belisário, André Rolim; Sales, Rahyssa Rodrigues; Toledo, Nayara Evelin; Muniz, Maristela Braga de Sousa Rodrigues; Velloso-Rodrigues, Cibele; Silva, Célia Maria; Viana, Marcos Borato

    2016-10-01

    Stroke is a severe clinical manifestation of sickle cell anemia (SCA). Despite the prognostic relevance of transcranial Doppler (TCD), more accurate tools to assess stroke risk in children with SCA are required. Here, we describe the effect of clinical, laboratory, and molecular features on the risk of stroke and high-risk TCD in children from the newborn cohort of Minas Gerais, Brazil. Outcomes studied were acute cerebral ischemia and high-risk TCD. Clinical and hematological data were retrieved from children's records. Genetic markers, which were known for their association with stroke risk, were genotyped by polymerase chain reaction/restriction fragment length polymorphism and sequencing. The cumulative incidence of acute cerebral ischemia by the age of 8 years was 7.4 % and that of high-risk TCD by the age of 11.5 years was 14.2 %. The final multivariate model for acute cerebral ischemia risk included high white blood cell count and reticulocyte count, acute chest syndrome rate, and the single nucleotide polymorphisms (SNPs) TEK rs489347 and TNF-α rs1800629. The model for high-risk TCD included high reticulocyte count and the SNPs TEK rs489347 and TGFBR3 rs284875. Children with risk factors should be considered for intensive risk monitoring and for intervention therapy.

  20. A METHOD OF CORONARY RETROPERFUSION FOR THE TREATMENT OF ACUTE MYOCARDIAL ISCHEMIA.

    PubMed

    Feola, Mario; Wiener, Leslie

    1978-09-01

    A method of retrograde perfusion of the myocardium has been developed in dogs. It consists of a double lumen balloon-tipped catheter inserted transvenously into the coronary sinus, with one lumen connected to a roller pump, the other to a helium counterpulsing pump. Oxygenated heparinized blood is obtained from the femoral artery and pumped continuously into the coronary sinus at a pressure of 50-75 mm Hg. The balloon is inflated during diastole, sealing the coronary sinus and promoting retrograde flow, and is deflated during systole, allowing blood drainage into the right atrium and preventing venous congestion. Thirteen anesthetized open-chest dogs were subjected to 15 minutes of proximal LAD artery occlusion and 30 minutes of diastolic coronary sinus perfusion (DCSP). The area of ischemia was mapped by means of platinum electrodes capable of simultaneously measuring myocardial tissue oxygen tension M(p)O(2)) and electrograms. Reduction of M(p)O(2) with simultaneous elevation of the ST segment on the corresponding electrogram was considered an indication of ischemia. Diastolic coronary sinus perfusion improved myocardial oxygen tension in the ischemic myocardium, reduced ST segment elevation, and tended to restore arterial blood pressure. Histologically, there was no intramyocardial hemorrhage.

  1. Acute ischemia/reperfusion injury after isogeneic kidney transplantation is mitigated in a rat model of chronic renal failure.

    PubMed

    Vercauteren, Sven R; Ysebaert, Dirk K; Van Rompay, An R; De Greef, Kathleen E; De Broe, Marc E

    2003-05-01

    The influence of chronic renal failure on renal susceptibility to an acute ischemic insult was evaluated. Recipient Lewis rats were randomly assigned to undergo 5/6 nephrectomy (chronic renal failure, CRF) or sham operation (normal renal function, NRF). After 11 weeks, normal kidneys of Lewis donor rats were transplanted in the recipients. The outcome of the isografts was assessed. Filtration capacity of the isografts in the CRF rats was preserved to approximately one-quarter of its normal capacity on the 1st day post-transplantation, whereas it fell to 0 in the NRF rats. This was reflected by a significantly higher increase in serum creatinine in the latter group. The isografts in the CRF rats had a significantly lower degree of acute tubular necrosis and no increase in the number of macrophages and T lymphocytes in the first 24 h in contrast to the NRF rats. Epithelial regeneration and repair started earlier in the CRF group. In conclusion, the present study indicated that CRF blunted ischemia/reperfusion injury of a transplanted kidney, and that its regeneration capacity was certainly not hampered by the presence of chronic uremia. These results will be the basis for studies on modulation of early leukocyte-endothelial interactions resulting from immunological disturbances inherent to the uremic environment.

  2. Intestinal ischemia in neonates and children.

    PubMed

    Jeican, Ionuţ Isaia; Ichim, Gabriela; Gheban, Dan

    2016-01-01

    The article reviews the intestinal ischemia theme on newborn and children. The intestinal ischemia may be either acute - intestinal infarction (by vascular obstruction or by reduced mesenteric blood flow besides the occlusive mechanism), either chronic. In neonates, acute intestinal ischemia may be caused by aortic thrombosis, volvulus or hypoplastic left heart syndrome. In children, acute intestinal ischemia may be caused by fibromuscular dysplasia, volvulus, abdominal compartment syndrome, Burkitt lymphoma, dermatomyositis (by vascular obstruction) or familial dysautonomia, Addison's disease, situs inversus abdominus (intraoperative), burns, chemotherapy administration (by nonocclusive mesenteric ischemia). Chronic intestinal ischemia is a rare condition in pediatrics and can be seen in abdominal aortic coarctation or hypoplasia, idiopathic infantile arterial calcinosis.

  3. Validation of fast diffusion kurtosis MRI for imaging acute ischemia in a rodent model of stroke

    PubMed Central

    Sun, Phillip Zhe; Wang, Yu; Mandeville, Emiri; Chan, Suk-Tak; Lo, Eng H; Ji, Xunming

    2014-01-01

    Diffusion-weighted imaging (DWI) captures ischemic tissue that is likely to infarct, and has become one of the most widely used acute stroke imaging techniques. Diffusion kurtosis imaging (DKI) has lately been postulated as a complementary MRI method to stratify the heterogeneously damaged DWI lesion. However, the conventional DKI acquisition time is relatively long, limiting its use in the acute stroke setting. Recently, Hansen et al. proposed a fast kurtosis mapping method and demonstrated it in fixed brains and control subjects. The fast DKI approach provides mean diffusion and kurtosis measurements under substantially reduced scan time, making it amenable to acute stroke imaging. Because it is not practical to obtain and compare different means of DKI to test whether the fast DKI method can reliably detect diffusion and kurtosis lesions in acute stroke patients, our study investigated its diagnostic value using an animal model of acute stroke, a critical step before fast DKI acquisition can be routinely applied in the acute stroke setting. We found significant correlation, per voxel, between the diffusion and kurtosis coefficients measured using the fast and conventional DKI protocols. In acute stroke rats, both DKI methods yielded diffusion and kurtosis lesions that were in good agreement. Importantly, substantial kurtosis/diffusion lesion mismatch was observed using the conventional (26±13%, P<0.01) and fast DKI methods (23±8%, P<0.01). In addition, regression analysis showed that the kurtosis/diffusion lesion mismatch obtained using conventional and fast DKI methods were substantially correlated (R2=0.57, P=0.02). Our results confirmed that the recently proposed fast DKI method is capable of capturing heterogeneous diffusion and kurtosis lesions in acute ischemic stroke, and thus is suitable for translational applications in the acute stroke clinical setting. PMID:25208309

  4. Validation of fast diffusion kurtosis MRI for imaging acute ischemia in a rodent model of stroke.

    PubMed

    Sun, Phillip Zhe; Wang, Yu; Mandeville, Emiri; Chan, Suk-Tak; Lo, Eng H; Ji, Xunming

    2014-11-01

    Diffusion-weighted imaging (DWI) captures ischemic tissue that is likely to infarct, and has become one of the most widely used acute stroke imaging techniques. Diffusion kurtosis imaging (DKI) has lately been postulated as a complementary MRI method to stratify the heterogeneously damaged DWI lesion. However, the conventional DKI acquisition time is relatively long, limiting its use in the acute stroke setting. Recently, a fast kurtosis mapping method has been demonstrated in fixed brains and control subjects. The fast DKI approach provides mean diffusion and kurtosis measurements under substantially reduced scan time, making it amenable to acute stroke imaging. Because it is not practical to obtain and compare different means of DKI to test whether the fast DKI method can reliably detect diffusion and kurtosis lesions in acute stroke patients, our study investigated its diagnostic value using an animal model of acute stroke, a critical step before fast DKI acquisition can be routinely applied in the acute stroke setting. We found significant correlation, per voxel, between the diffusion and kurtosis coefficients measured using the fast and conventional DKI protocols. In acute stroke rats, the two DKI methods yielded diffusion and kurtosis lesions that were in good agreement. Importantly, substantial kurtosis-diffusion lesion mismatch was observed using the conventional (26 ± 13%, P < 0.01) and fast DKI methods (23 ± 8%, P < 0.01). In addition, regression analysis showed that the kurtosis-diffusion lesion mismatches obtained using conventional and fast DKI methods were substantially correlated (R(2) = 0.57, P = 0.02). Our results confirmed that the recently proposed fast DKI method is capable of capturing heterogeneous diffusion and kurtosis lesions in acute ischemic stroke, and thus is suitable for translational applications in the acute stroke clinical setting.

  5. Effects of Acute Systemic Hypoxia and Hypercapnia on Brain Damage in a Rat Model of Hypoxia-Ischemia

    PubMed Central

    Zhang, Xuezhong; Wang, Nan; Tan, Jing; Fang, Xianhai; Wang, Qi; Tao, Tao; Li, Wenzhi

    2016-01-01

    Therapeutic hypercapnia has the potential for neuroprotection after global cerebral ischemia. Here we further investigated the effects of different degrees of acute systemic hypoxia in combination with hypercapnia on brain damage in a rat model of hypoxia and ischemia. Adult wistar rats underwent unilateral common carotid artery (CCA) ligation for 60 min followed by ventilation with normoxic or systemic hypoxic gas containing 11%O2,13%O2,15%O2 and 18%O2 (targeted to PaO2 30–39 mmHg, 40–49 mmHg, 50–59 mmHg, and 60–69 mmHg, respectively) or systemic hypoxic gas containing 8% carbon dioxide (targeted to PaCO2 60–80 mmHg) for 180 min. The mean artery pressure (MAP), blood gas, and cerebral blood flow (CBF) were evaluated. The cortical vascular permeability and brain edema were examined. The ipsilateral cortex damage and the percentage of hippocampal apoptotic neurons were evaluated by Nissl staining and terminal deoxynucleotidyl transferase-mediated 2′-deoxyuridine 5′-triphosphate-biotin nick end labeling (TUNEL) assay as well as flow cytometry, respectively. Immunofluorescence and western blotting were performed to determine aquaporin-4 (AQP4) expression. In rats treated with severe hypoxia (PaO2 < 50 mmHg), hypercapnia augmented the decline of MAP with cortical CBF and damaged blood–brain barrier permeability (p < 0.05). In contrast, in rats treated with mild to moderate hypoxia (PaO2 > 50 mmHg), hypercapnia protected against these pathophysiological changes. Moreover, hypercapnia treatment significantly reduced brain damage in the ischemic ipsilateral cortex and decreased the percentage of apoptotic neurons in the hippocampus after the CCA ligated rats were exposed to mild or moderate hypoxemia (PaO2 > 50 mmHg); especially under mild hypoxemia (PaO2 > 60 mmHg), hypercapnia significantly attenuated the expression of AQP4 protein with brain edema (p < 0.05). Hypercapnia exerts beneficial effects under mild to moderate hypoxemia and augments detrimental

  6. Hydrogen gas reduced acute hyperglycemia-enhanced hemorrhagic transformation in a focal ischemia rat model.

    PubMed

    Chen, C H; Manaenko, A; Zhan, Y; Liu, W W; Ostrowki, R P; Tang, J; Zhang, J H

    2010-08-11

    Hyperglycemia is one of the major factors for hemorrhagic transformation after ischemic stroke. In this study, we tested the effect of hydrogen gas on hemorrhagic transformation in a rat focal cerebral ischemia model. Sprague-Dawley rats (n=72) were divided into the following groups: sham; sham treated with hydrogen gas (H(2)); Middle Cerebral Artery Occlusion (MCAO); and MCAO treated with H(2) (MCAO+H(2)). All rats received an injection of 50% dextrose (6 ml/kg i.p.) and underwent MCAO 15 min later. Following a 90 min ischemic period, hydrogen was inhaled for 2 h during reperfusion. We measured the level of blood glucose at 0 h, 0.5 h, 4 h, and 6 h after dextrose injection. Infarct and hemorrhagic volumes, neurologic score, oxidative stress (evaluated by measuring the level of 8 Hydroxyguanosine (8OHG), 4-Hydroxy-2-Nonenal (HNE) and nitrotyrosine), and matrix metalloproteinase (MMP)-2/MMP-9 activity were measured at 24 h after ischemia. We found that hydrogen inhalation for 2 h reduced infarct and hemorrhagic volumes and improved neurological functions. This effect of hydrogen was accompanied by a reduction of the expression of 8OHG, HNE, and nitrotyrosine and the activity of MMP-9. Furthermore, a reduction of the blood glucose level from 500+/-32.51 to 366+/-68.22 mg/dl at 4 h after dextrose injection was observed in hydrogen treated animals. However, the treatment had no significant effect on the expression of ZO-1, occludin, collagen IV or aquaporin4 (AQP4). In conclusion, hydrogen gas reduced brain infarction, hemorrhagic transformation, and improved neurological function in rats. The potential mechanisms of decreased oxidative stress and glucose levels after hydrogen treatment warrant further investigation.

  7. Ukrain (NSC 631570) ameliorates intestinal ischemia-reperfusion-induced acute lung injury by reducing oxidative stress

    PubMed Central

    Kocak, Cengiz; Kocak, Fatma Emel; Akcilar, Raziye; Akcilar, Aydin; Savran, Bircan; Zeren, Sezgin; Bayhan, Zulfu; Bayat, Zeynep

    2016-01-01

    Intestinal ischemia-reperfusion (I/R) causes severe destruction in remote organs. Lung damage is a frequently seen complication after intestinal I/R. Ukrain (NSC 631570) is a synthetic thiophosphate derivative of alkaloids from the extract of the celandine (Chelidonium majus L.) plant. We investigated the effect of Ukrain in animals with lung injury induced by intestinal I/R. Adult male Spraque-Dawley rats were randomly divided into four groups: control, Ukrain, I/R, I/R with Ukrain. Before intestinal I/R was induced, Ukrain was administered intraperitoneally at a dose of 7.0 mg/body weight. After 1 h ischemia and 2 h reperfusion period, lung tissues were excised. Tissue levels of total oxidative status (TOS), total antioxidant status (TAS) were measured and oxidative stress indices (OSI) were calculated. Lung tissues were also examined histopathologically. TOS and OSI levels markedly increased and TAS levels decreased in the I/R group compared to the control group (P < 0.05). TOS and OSI levels markedly decreased and TAS levels increased in the I/R with Ukrain group compared with the group subjected to IR only (P < 0.05). Severe hemorrhage, alveolar septal thickening, and leukocyte infiltration were observed in the I/R group. In the I/R with Ukrain group, morphologic changes occurring as a result of lung damage attenuated and histopathological scores reduced compared to the I/R group (P < 0.05). Our results suggest that Ukrain pretreatment could reduce lung injury induced by intestinal I/R induced via anti-inflammatory and antioxidant effects. PMID:26773189

  8. The influence of hypertonic mannitol on regional myocardial blood flow during acute and chronic myocardial ischemia in anesthetized and awake intact dogs.

    PubMed Central

    Willerson, J T; Watson, J T; Hutton, I; Fixler, D E; Curry, G C; Templeton, G H

    1975-01-01

    The influence of hypertonic mannitol on regional myocardial blood flow and ventricular performance was studied during acute myocardial ischemia in awake, unsedated and in anesthesized dogs and after myocardial infarction in awake unsedated dogs. Regional myocardial blood flow was measured with radioactive microspheres. Generalized increases in regional myocardial blood flow occurred after mannitol in all of the different animal models studied. The increases in coronary blood flow after mannitol were just as impressive in the nonischemic regions as in the ischemic portion of the left ventricle in all of the different models that were examined in this study. Improvement in regional myocardial blood flow to the ischemic area of the left ventricle after mannitol was associated with a reduction in ST segment elevation during acute myocardial ischemia in anesthetized dogs. The increases in regional myocardial flow after mannitol were also associated with increases in contractility, but the increases in flow appeared to be more impressive than the changes in contractility. The data obtained demonstrate that mannitol increases regional coronary blood flow to both ischemic and nonischemic myocardium in both anesthetized and awake, unsedated, intact dogs with acute and chronic myocardial ischemia and that mannitol reduces ST segment elevation during acute myocardial ischemia in anesthetized dogs. Thus the results suggest that under these circumstances the increases in regional myocardial blood flow after mannitol are of physiological importance in reducing the extent of myocardial injury. Since coronary blood flow increased to nonischemic regions the increases in regional myocardial flow demonstrated in this study after mannitol cannot be entirely explained by the mechanism of reduction in ischemic cell swelling. PMID:1123427

  9. Matrix metalloproteinase-9 expression in retinal ganglion cell layer and effect of topically applied brimonidine tartrate 0.2% therapy on this expression in an endothelin-1-induced optic nerve ischemia model.

    PubMed

    Aktas, Zeynep; Gurelik, Gokhan; Göçün, Pinar Uyar; Akyürek, Nalan; Onol, Merih; Hasanreisoğlu, Berati

    2010-06-01

    The purpose of this research is to investigate the expression of matrix metalloproteinase-9 (MMP-9) in retinal ganglion cells (RGC) and the impact of topically applied brimonidine tartrate 0.2% (BMD) on this expression in an endothelin-1 (ET-1)-induced chronic optic nerve (ON) ischemia model of rabbit. Osmotically driven minipumps were implanted in one eye of 16 New Zealand albino rabbits to deliver ET-1 at the constant rate of 0.5 microl/h for 2 weeks. ET-1 was given with (group 3) and without topical BMD therapy (group 1). Groups 2 and 4 were taken as controls. MMP-9 expression by immunohistochemically and proportion of cells undergoing apoptosis in RGC layer were investigated. The correlation between the MMP-9 immunopositivity and the proportion of cells undergoing apoptosis in the RGC layer was evaluated. MMP-9 immunopositivity was found to be significantly higher in both groups 1 and 3 compared to that of the controls. There was no difference between groups 1 and 3 regarding MMP-9 expression (p = 0.495). A positive correlation was found between the proportion of cells undergoing apoptosis and MMP-9 expressions in the RGC layer in group 1 (p = 0.031, r = 0.754). MMP-9 expression in the RGC layer seems to significantly increase in the ET-1-induced chronic ON ischemia model. Topical BMD therapy does not seem to affect this MMP-9 expression.

  10. Neuroprotective and antiapoptotic activity of lineage-negative bone marrow cells after intravitreal injection in a mouse model of acute retinal injury.

    PubMed

    Machalińska, Anna; Rogińska, Dorota; Pius-Sadowska, Ewa; Kawa, Miłosz P; Paczkowska, Edyta; Rudnicki, Michał; Lejkowska, Renata; Baumert, Bartłomiej; Wiszniewska, Barbara; Machaliński, Bogusław

    2015-01-01

    We investigated effects of bone marrow-derived, lineage-negative cell (Lin(-)BMC) transplantation in acute retinal injury. Lin(-)BMCs were intravitreally injected into murine eyes at 24 h after NaIO3-induced injury. Morphology, function, and expression of apoptosis-related genes, including brain-derived neurotrophic factor (BDNF) and its receptor, were assessed in retinas at 7 days, 28 days, and 3 months after transplantation. Moreover, global gene expression at day 7 was analyzed by RNA arrays. We observed that Lin(-)BMCs integrated into outer retinal layers improving morphological retinal structure and induced molecular changes such as downregulation of proapoptotic caspase-3 gene, a decrease in BAX/BCL-2 gene ratio, and significant elevation of BDNF expression. Furthermore, transplanted Lin(-)BMCs differentiated locally into cells with a macrophage-like phenotype. Finally, Lin(-)BMCs treatment was associated with generation of two distinct transcriptomic patterns. The first relates to downregulated genes associated with regulation of neuron cell death and apoptosis, response to oxidative stress/hypoxia and external stimuli, and negative regulation of cell proliferation. The second relates to upregulated genes associated with neurological system processes and sensory perception. Collectively, our data demonstrate that transplanted Lin(-)BMCs exert neuroprotective function against acute retinal injury and this effect may be associated with their antiapoptotic properties and ability to express neurotrophic factors.

  11. Neuroprotective and Antiapoptotic Activity of Lineage-Negative Bone Marrow Cells after Intravitreal Injection in a Mouse Model of Acute Retinal Injury

    PubMed Central

    Machalińska, Anna; Pius-Sadowska, Ewa; Kawa, Miłosz P.; Paczkowska, Edyta; Rudnicki, Michał; Lejkowska, Renata; Baumert, Bartłomiej; Wiszniewska, Barbara; Machaliński, Bogusław

    2015-01-01

    We investigated effects of bone marrow-derived, lineage-negative cell (Lin−BMC) transplantation in acute retinal injury. Lin−BMCs were intravitreally injected into murine eyes at 24 h after NaIO3-induced injury. Morphology, function, and expression of apoptosis-related genes, including brain-derived neurotrophic factor (BDNF) and its receptor, were assessed in retinas at 7 days, 28 days, and 3 months after transplantation. Moreover, global gene expression at day 7 was analyzed by RNA arrays. We observed that Lin−BMCs integrated into outer retinal layers improving morphological retinal structure and induced molecular changes such as downregulation of proapoptotic caspase-3 gene, a decrease in BAX/BCL-2 gene ratio, and significant elevation of BDNF expression. Furthermore, transplanted Lin−BMCs differentiated locally into cells with a macrophage-like phenotype. Finally, Lin−BMCs treatment was associated with generation of two distinct transcriptomic patterns. The first relates to downregulated genes associated with regulation of neuron cell death and apoptosis, response to oxidative stress/hypoxia and external stimuli, and negative regulation of cell proliferation. The second relates to upregulated genes associated with neurological system processes and sensory perception. Collectively, our data demonstrate that transplanted Lin−BMCs exert neuroprotective function against acute retinal injury and this effect may be associated with their antiapoptotic properties and ability to express neurotrophic factors. PMID:25810725

  12. [Characteristics of antiischemic and nootropic properties of ademol in a rat model of acute brain ischemia].

    PubMed

    Khodakivs'kyĭ, O A

    2013-01-01

    In experiments with the rat model of acute disorder of encephalic circulation (bilateral carotid occlusion) it was found that introduction of derivate of adamantan 1-adamantiloxy-3-morfolino-2 propanol (under conventional name ademol) in the dose 2 mg/kg intraabdominal in treatment regimen (in an hour after reconstruction of insult and further 1 time every 24 hours during 21 days) was accompanied by a recovery of mnemotropic properties and is more effective than cytikolin, resulting in a decreased lethality and neurological deficiency in acute and recovery periods of insults. The data received proved the usefulness of development of ademol based cerebroprotective remedy.

  13. [Acute extremity ischemia based on the popliteal artery aneurysm thrombosis--combined thrombolytic and surgical management].

    PubMed

    Danek, T; Janousek, R; Havlícek, K

    2006-03-01

    Authors present their experience with combined trombolytic-surgical treatment of acute ischaemia of low extremity based on trombosis of popliteal artery aneurysm. This treatment was performed in three patients. Authors compare results of intraarterial catheter pharmacological trombolysis of infrapopliteal arteries with indirect surgical trombolysis.

  14. Integrated microRNA and mRNA responses to acute human left ventricular ischemia.

    PubMed

    Saddic, Louis A; Chang, Tzuu-Wang; Sigurdsson, Martin I; Heydarpour, Mahyar; Raby, Benjamin A; Shernan, Stanton K; Aranki, Sary F; Body, Simon C; Muehlschlegel, Jochen D

    2015-10-01

    MicroRNAs (miRNAs) play a significant role in ischemic heart disease. Animal models of left ventricular (LV) ischemia demonstrate a unique miRNA profile; however, these models have limitations in describing human disease. In this study, we performed next-generation miRNA and mRNA sequencing on LV tissue from nine patients undergoing cardiac surgery with cardiopulmonary bypass and cardioplegic arrest. Samples were obtained immediately after aortic cross clamping (baseline) and before aortic cross clamp removal (postischemic). Of 1,237 identified miRNAs, 21 were differentially expressed between baseline and postischemic LV samples including the upregulated miRNAs miR-339-5p and miR-483-3p and the downregulated miRNA miR-139-5p. Target prediction analysis of these miRNAs was integrated with mRNA expression from the same LV samples to identify anticorrelated miRNA-mRNA pairs. Gene enrichment studies of candidate mRNA targets demonstrated an association with cardiovascular disease, cell death, and metabolism. Therapeutics that intervene on these miRNAs and their downstream targets may lead to novel mechanisms of mitigating the damage caused by ischemic insults on the human heart.

  15. Nuclear Factor kB and Inhibitor of kB: Acupuncture Protection Against Acute Focal Cerebral Ischemia in Rodents.

    PubMed

    Huang, Wei; Zhou, Zhongyu; Wan, Bijiang; Chen, Guang; Li, Jia

    2017-02-27

    Context • Acute, focal, cerebral ischemic stroke is a leading cause of morbidity and mortality worldwide. Acupuncture is an emerging alternative therapy for treatment of acute brain ischemia. Nevertheless, the precise mechanism underlying the neuroprotective effects of acupuncture has not been elucidated. Nuclear factor κB (NF-κB) and nuclear factor of κ light polypeptide gene enhancer in B cell inhibitor alpha (IκB-α) are involved in cerebral inflammation. However, the involvement of NF-κB and IκB-α in the protective effects of acupuncture on ischemic tolerance remains unknown. Objective • The study evaluated the hypothesis that acupuncture can exert a neuroprotective action in a rat model of middle cerebral artery occlusion (MCAO). Design • The rats were randomly divided into a normal group (N), a sham model group (SM), an MCAO model group (M), a sham acupuncture group (SA), and an acupuncture group (A). Setting • All of processes of this study were conducted at Hubei University of Chinese Medicine (Hubei Shang, China). Animals • The animals were 100 Sprague-Dawley rats, aged 3 mo. Intervention • Craniotomy and electrocoagulation of the middle cerebral artery were conducted to generate acute, focal, cerebral ischemic models in 3 groups, excluding the N and SM groups. The SM group received a surgical fenestration similar to the M group, but the procedure did not include the coagulation of the exposed artery. In the A group, acupuncture was administered at the acupoints Baihui (GV-20) and Renzhong (GV-26). In the SA group, sham acupuncture was performed at a depth of 5 mm at a position close to the left side of the GV-20 and GV-26 points. The N, M, and SM groups received neither the acupuncture nor the sham acupuncture treatment. Outcome Measures • The study (1) evaluated neurological function using the modified neurological severity score; (2) examined the ultrastructure; (3) assessed the infarct volume; (4) determined levels of serum

  16. Effects of the PPAR-α agonist fenofibrate on acute and short-term consequences of brain ischemia

    PubMed Central

    Ouk, Thavarak; Gautier, Sophie; Pétrault, Maud; Montaigne, David; Maréchal, Xavier; Masse, Isabelle; Devedjian, Jean-Christophe; Deplanque, Dominique; Bastide, Michèle; Nevière, Rémi; Duriez, Patrick; Staels, Bart; Pasquier, Florence; Leys, Didier; Bordet, Régis

    2014-01-01

    In stroke, there is an imperative need to develop disease-modifying drugs able to (1) induce neuroprotection and vasculoprotection, (2) modulate recovery and brain plasticity, and (3) limit the short-term motor and cognitive consequences. We hypothesized that fenofibrate, a peroxisome proliferator-activated receptor-α (PPAR-α) agonist, could exert a beneficial effect on immediate and short-term poststroke consequences related to its pleiotropic mechanisms. Rats or mice were subjected to focal ischemia to determine the effects of acute treatment by fenofibrate on (i) motor and memory impairment, (2) both cerebral and vascular compartments, (3) inflammation, (4) neurogenesis, and (5) amyloid cascade. We show that fenofibrate administration results in both neuronal and vascular protection and prevents the short-term motor and cognitive poststroke consequences by interaction with several mechanisms. Modulation of PPAR-α generates beneficial effects in the immediate poststroke consequences by mechanisms involving the interactions between polynuclear neutrophils and the vessel wall, and microglial activation. Fenofibrate modulates mechanisms involved in neurorepair and amyloid cascade. Our results suggest that PPAR-α agonists could check the key points of a potential disease-modifying effect in stroke. PMID:24398933

  17. AT1 receptor antagonism before ischemia prevents the transition of acute kidney injury to chronic kidney disease.

    PubMed

    Rodríguez-Romo, Roxana; Benítez, Kenia; Barrera-Chimal, Jonatan; Pérez-Villalva, Rosalba; Gómez, Arturo; Aguilar-León, Diana; Rangel-Santiago, Jesús F; Huerta, Sara; Gamba, Gerardo; Uribe, Norma; Bobadilla, Norma A

    2016-02-01

    Despite clinical recovery of patients from an episode of acute kidney injury (AKI), progression to chronic kidney disease (CKD) is possible on long-term follow-up. However, mechanisms of this are poorly understood. Here, we determine whether activation of angiotensin-II type 1 receptors during AKI triggers maladaptive mechanisms that lead to CKD. Nine months after AKI, male Wistar rats develop CKD characterized by renal dysfunction, proteinuria, renal hypertrophy, glomerulosclerosis, tubular atrophy, and tubulointerstitial fibrosis. Renal injury was associated with increased oxidative stress, inflammation, α-smooth muscle actin expression, and activation of transforming growth factor β; the latter mainly found in epithelial cells. Although administration of losartan prior to the initial ischemic insult did not prevent or reduce AKI severity, it effectively prevented eventual CKD. Three days after AKI, renal dysfunction, tubular structural injury, and elevation of urinary biomarkers were present. While the losartan group had similar early renal injury, renal perfusion was completely restored as early as day 3 postischemia. Further, there was increased vascular endothelial growth factor expression and an early activation of hypoxia-inducible factor 1 α, a transcription factor that regulates expression of many genes that help reduce renal injury. Thus, AT1 receptor antagonism prior to ischemia prevented AKI to CKD transition by improving early renal blood flow recovery, lesser inflammation, and increased hypoxia-inducible factor 1 α activity.

  18. Endovascular treatment of acute limb ischemia and proximal deep vein thrombosis using rotational thrombectomy: A review of published literature.

    PubMed

    Lichtenberg, Michael; Stahlhoff, Friedrich-Wilhelm; Boese, Dirk

    2013-01-01

    Acute and subacute ischemia of the lower extremity is still a common reason for amputation. The treatment of this condition includes the well known procedure of local thrombolysis, surgical thrombectomy and, in recent times, percutaneous mechanical thrombectomy procedures such as rotational thrombectomy. However, in randomized studies Fogarty's procedure of surgical thrombectomy was associated with a high rate of perioperative complications and, in part, low technical success rates. On the other hand, local thrombolysis is associated with hemorrhage as well as high costs because of measures requiring substantial resources, such as intensive care monitoring or repeat angiographies. In several studies, the endovascular therapy options of Straub Rotarex® and Aspirex® systems, both products of technical advancements in the field, were shown to be successful in terms of amputation-free survival. Their use was also associated with low complication rates. The majority of studies were focused on arterial blood flow in the femur. However, in the meantime several registers and studies have shown that the systems can also be effectively used to treat proximal deep vein thrombosis. In the present report we review the current study-based value of rotational thrombectomy in the venous and arterial system.

  19. Neuroprotective Effect of Resveratrol on Acute Brain Ischemia Reperfusion Injury by Measuring Annexin V, p53, Bcl-2 Levels in Rats

    PubMed Central

    Kizmazoglu, Ceren; Aydin, Hasan Emre; Sevin, Ismail Ertan; Yüceer, Nurullah; Atasoy, Metin Ant

    2015-01-01

    Background Cerebral ischemia is as a result of insufficient cerebral blood flow for cerebral metabolic functions. Resveratrol is a natural phytoalexin that can be extracted from grape's skin and had potent role in treating the cerebral ischemia. Apoptosis, a genetically programmed cellular event which occurs after ischemia and leads to biochemical and morphological changes in cells. There are some useful markers for apoptosis like Bcl-2, bax, and p53. The last reports, researchers verify the apoptosis with early markers like Annexin V. Methods We preferred in this experimental study a model of global cerebral infarction which was induced by bilateral common carotid artery occlusion method. Rats were randomly divided into 4 groups : sham, ischemia-reperfusion (I/R), I/R plus 20 mg/kg resveratrol and I/R plus 40 mg/kg resveratrol. Statistical analysis was performed using Sigmastat 3.5 ve IBM SPSS Statistics 20. We considered a result significant when p<0.001. Results After administration of resveratrol, Bcl-2 and Annexin levels were significantly increased (p<0.001). Depending on the dose of resveratrol, Bcl2 levels increased, p53 levels decreased but Annexin V did not effected. P53 levels were significantly increased in ishemia group, so apoptosis is higher compared to other groups. Conclusion In the acute period, Annexin V levels misleading us because the apoptotic cell counts could not reach a certain level. Therefore we should support our results with bcl-2 and p53. PMID:26819684

  20. Acute Multi-modal Neuroimaging in a Porcine Model of Endothelin-1-Induced Cerebral Ischemia: Defining the Acute Infarct Core.

    PubMed

    d'Esterre, Christopher D; Aviv, Richard I; Morrison, Laura; Fainardi, Enrico; Lee, Ting Yim

    2015-06-01

    In a porcine ischemic stroke model, we sought to compare the acute predicted infarct core volume (PIV) defined by CT perfusion (CTP)-hemodynamic parameters and MR-diffusion-weighted imaging (MR-DWI)/apparent diffusion coefficient (ADC), with the true infarct core volume (TIV) as defined by histology. Ten Duroc-cross pigs had a CTP scan prior to injection of endothelin-1 (ET-1) into the left striatum. CTP scans were used to monitor ischemic progression. A second dose of ET-1 was injected 2 h from the first injection. The animal was moved to a 3-T MRI scanner where DWI was performed. CTP imaging was acquired immediately after the MR imaging. Next, the brain was removed and stained with tetrazolium chloride (TTC). Linear regression and Bland-Altman plots were used to correlate the PIV measured by each imaging modality to that of the TIV from the histological gold standard. The CTP-cerebral blood flow (CBF) parameter had the highest R (2) value and slope closest to unity, while the CTP-cerebral blood volume (CBV) had the lowest R(2) value and slope furthest away from unity. The CTP-CBF • CBV product parameter had a higher R(2) value but lower slope than both MR parameers. The best Bland-Altman agreement was observed with the CTP-CBF parameter. PIV from MR-DWI, ADC, and CTP-CBF overestimated the TIV defined with histology. We show that the PIV defined with absolute gray and white matter CT-CBF thresholds correlates best with the TIV and is similar to both MR-DWI and ADC-defined PIVs. Further, the acute CBF • CBV mismatch may not indicate penumbral tissue in the acute stroke setting.

  1. The Kynurenine Pathway in the Acute and Chronic Phases of Cerebral Ischemia

    PubMed Central

    Cuartero, María Isabel; de la Parra, Juan; García-Culebras, Alicia; Ballesteros, Iván; Lizasoain, Ignacio; Moro, María Ángeles

    2016-01-01

    Kynurenines are a wide range of catabolites which derive from tryptophan through the “Kynurenine Pathway” (KP). In addition to its peripheral role, increasing evidence shows a role of the KP in the central nervous system (CNS), mediating both physiological and pathological functions. Indeed, an imbalance in this route has been associated with several neurodegenerative disorders such as Alzheimer’s and Huntington’s diseases. Altered KP catabolism has also been described during both acute and chronic phases of stroke; however the contribution of the KP to the pathophysiology of acute ischemic damage and of post-stroke disorders during the chronic phase including depression and vascular dementia, and the exact mechanisms implicated in the regulation of the KP after stroke are not well established yet. A better understanding of the regulation and activity of the KP after stroke could provide new pharmacological tools in both acute and chronic phases of stroke. In this review, we will make an overview of CNS modulation by the KP. We will detail the KP contribution in the ischemic damage, how the unbalance of the KP might trigger an alteration of the cognitive function after stroke as well as potential targets for the development of new drugs. PMID:25248805

  2. Nestin(+) kidney resident mesenchymal stem cells for the treatment of acute kidney ischemia injury.

    PubMed

    Jiang, Mei Hua; Li, Guilan; Liu, Junfeng; Liu, Longshan; Wu, Bingyuan; Huang, Weijun; He, Wen; Deng, Chunhua; Wang, Dong; Li, Chunling; Lahn, Bruce T; Shi, Chenggang; Xiang, Andy Peng

    2015-05-01

    Renal resident mesenchymal stem cells (MSCs) are important regulators of kidney homeostasis, repair or regeneration. However, natural distribution and the starting population properties of these cells remain elusive because of the lack of specific markers. Here, we identified post-natal kidney derived Nestin(+) cells that fulfilled all of the criteria as a mesenchymal stem cell. These isolated Nestin(+) cells expressed the typical cell-surface marker of MSC, including Sca-1, CD44, CD106, NG2 and PDGFR-α. They were capable of self-renewal, possessed high clonogenic potential and extensive proliferation for more than 30 passages. Under appropriate differentiation conditions, these cells could differentiate into adipocytes, osteocytes, chondrocytes and podocytes. After intravenous injection into acute kidney injury mice, Nestin(+) cells contributed to functional improvement by significantly decreasing the peak level of serum creatinine and BUN, and reducing the damaged cell apoptosis. Furthermore, conditioned medium from Nestin(+) cells could protect against ischemic acute renal failure partially through paracrine factor VEGF. Taken together, our findings indicate that renal resident Nestin(+) MSCs can be derived, propagated, differentiated, and repair the acute kidney injury, which may shed new light on understanding MSCs biology and developing cell replacement therapies for kidney disease.

  3. Changes in metabolic profiles during acute kidney injury and recovery following ischemia/reperfusion.

    PubMed

    Wei, Qingqing; Xiao, Xiao; Fogle, Paul; Dong, Zheng

    2014-01-01

    Changes of metabolism have been implicated in renal ischemia/reperfusion injury (IRI). However, a global analysis of the metabolic changes in renal IRI is lacking and the association of the changes with ischemic kidney injury and subsequent recovery are unclear. In this study, mice were subjected to 25 minutes of bilateral renal IRI followed by 2 hours to 7 days of reperfusion. Kidney injury and subsequent recovery was verified by serum creatinine and blood urea nitrogen measurements. The metabolome of plasma, kidney cortex, and medulla were profiled by the newly developed global metabolomics analysis. Renal IRI induced overall changes of the metabolome in plasma and kidney tissues. The changes started in renal cortex, followed by medulla and plasma. In addition, we identified specific metabolites that may contribute to early renal injury response, perturbed energy metabolism, impaired purine metabolism, impacted osmotic regulation and the induction of inflammation. Some metabolites, such as 3-indoxyl sulfate, were induced at the earliest time point of renal IRI, suggesting the potential of being used as diagnostic biomarkers. There was a notable switch of energy source from glucose to lipids, implicating the importance of appropriate nutrition supply during treatment. In addition, we detected the depressed polyols for osmotic regulation which may contribute to the loss of kidney function. Several pathways involved in inflammation regulation were also induced. Finally, there was a late induction of prostaglandins, suggesting their possible involvement in kidney recovery. In conclusion, this study demonstrates significant changes of metabolome kidney tissues and plasma in renal IRI. The changes in specific metabolites are associated with and may contribute to early injury, shift of energy source, inflammation, and late phase kidney recovery.

  4. Receptor mediated disruption of retinal pigment epithelium function in acute glycated-albumin exposure

    PubMed Central

    Dahrouj, Mohammad; Desjardins, Danielle M.; Liu, Yueying; Crosson, Craig E.; Ablonczy, Zsolt

    2015-01-01

    Diabetic macular edema (DME) is a major cause of visual impairment. Although DME is generally believed to be a microvascular disease, dysfunction of the retinal pigment epithelium (RPE) can also contribute to its development. Advanced glycation end-products (AGE) are thought to be one of the key factors involved in the pathogenesis of diabetes in the eye, and we have previously demonstrated a rapid breakdown of RPE function following glycated-albumin (Glyc-alb, a common AGE mimetic) administration in monolayer cultures of fetal human RPE cells. Here we present new evidence that this response is attributed to apically oriented AGE receptors (RAGE). Moreover, time-lapse optical coherence tomography in Dutch-belted rabbits 48 hours post intravitreal Glyc-alb injections demonstrated a significant decrease in RPE-mediated fluid resorption in vivo. In both the animal and tissue culture models, the response to Glyc-alb was blocked by the relatively selective RAGE antagonist, FPS-ZM1 and was also inhibited by ZM323881, a relatively selective vascular endothelial growth factor receptor 2 (VEGF-R2) antagonist. Our data establish that the Glyc-alb-induced breakdown of RPE function is mediated via specific RAGE and VEGF-R2 signaling both in vitro and in vivo. These results are consistent with the notion that the RPE is a key player in the pathogenesis of DME. PMID:26070987

  5. Retinal vein occlusion and the risk of acute myocardial infarction development: a 12-year nationwide cohort study.

    PubMed

    Rim, Tyler Hyungtaek; Han, John Seungsoo; Oh, Jaewon; Kim, Dong Wook; Kang, Seok-Min; Chung, Eun Jee

    2016-02-29

    The goal of this study was to evaluate the risk of developing acute myocardial infarction (AMI) following retinal vein occlusion (RVO). A retrospective cohort study was performed from the National Health Insurance Service and comprised 1,025,340 random subjects who were followed from 2002 to 2013. Patients with RVO in 2002 were excluded. The RVO group was composed of patients who received an initial RVO diagnosis between January 2003 and December 2007 (n = 1677). The comparison group was selected (five patients per RVO patient; n = 8367) using propensity score matching according to sociodemographic factors and the year of enrolment. Each patient was tracked until 2013. The Cox proportional hazard regression model was used. AMI developed in 7.6% of the RVO group and 5.3% of the comparison group (p < 0.001) for 7.7 median follow-up periods. RVO increased the risk of AMI development [hazard ratio (HR) = 1.25; 95% Confidence Interval (CI) 1.02 to 1.52]. In the subgroup analysis, RVO patients aged <65 years and the males within this age group had an adjusted HR of 1.47 (95% CI 1.10 to 1.98) and an adjusted HR of 2.00 (95% CI 1.38 to 2.91) for AMI development, respectively. RVO was significantly associated with AMI development.

  6. Acute retinal necrosis caused by herpes simplex virus type 2 in children: reactivation of an undiagnosed latent neonatal herpes infection.

    PubMed

    Grose, Charles

    2012-09-01

    Herpes simplex virus type 2 (HSV-2) is known to cause acute retinal necrosis (ARN). The availability of HSV-2-specific polymerase chain reaction tests for diagnostic analysis has greatly increased our ability to discriminate ARN caused by HSV-2 from ARN caused by either herpes simplex virus type 1 or varicella zoster virus (VZV). Of great interest, HSV-2 appears to be the most common cause of viral ARN in children and adolescents. Although a few children with ARN are known to have had neonatally acquired herpes infection, most children lack a history of known herpes disease. Thus, the origin of the HSV-2 infection is a mystery. The hypothesis of this review is that HSV-2 ARN in children and adolescents may be the first sign of a previously undiagnosed and asymptomatic neonatal HSV-2 infection, which has reactivated several years later from latency in a cranial nerve and entered the retina. The review brings together 7 previously published ARN cases, plus one new case is added. Thus, this review also expands the spectrum of complications from neonatal HSV-2 infection.

  7. Dissecting the Effects of Ischemia and Reperfusion on the Coronary Microcirculation in a Rat Model of Acute Myocardial Infarction

    PubMed Central

    Hollander, Maurits R.; de Waard, Guus A.; Konijnenberg, Lara S. F.; Meijer-van Putten, Rosalie M. E.; van den Brom, Charissa E.; Paauw, Nanne; de Vries, Helga E.; van de Ven, Peter M.; Aman, Jurjan; Van Nieuw-Amerongen, Geerten P.; Hordijk, Peter L.; Niessen, Hans W. M.; Horrevoets, Anton J. G.; Van Royen, Niels

    2016-01-01

    Background Microvascular injury (MVI) after coronary ischemia-reperfusion is associated with high morbidity and mortality. Both ischemia and reperfusion are involved in MVI, but to what degree these phases contribute is unknown. Understanding the etiology is essential for the development of new potential therapies. Methods and Findings Rats were divided into 3 groups receiving either 30 minutes ischemia, 90 minutes ischemia or 30 minutes ischemia followed by 60 minutes reperfusion. Subsequently hearts were ex-vivo perfused in a Langendorff-model. Fluorescence and electron microscopy was used for analysis of capillary density, vascular permeability and ultrastructure. Most MVI was observed after 30 minutes ischemia followed by 60 minutes reperfusion. In comparison to the 30’ and 90’ ischemia group, wall thickness decreased (207.0±74 vs 407.8±75 and 407.5±71, p = 0.02). Endothelial nuclei in the 30’-60’ group showed irreversible damage and decreased chromatin density variation (50.5±9.4, 35.4±7.1 and 23.7±3.8, p = 0.03). Cell junction density was lowest in the 30’-60’ group (0.15±0.02 vs 2.5±0.6 and 1.8±0.7, p<0.01). Microsphere extravasation was increased in both the 90’ ischemia and 30’-60’ group. Conclusions Ischemia alone for 90 minutes induces mild morphological changes to the coronary microcirculation, with increased vascular permeability. Ischemia for 30 minutes, followed by 60 minutes of reperfusion, induces massive MVI. This shows the direct consequences of reperfusion on the coronary microcirculation. These data imply that a therapeutic window exists to protect the microcirculation directly upon coronary revascularization. PMID:27391645

  8. Chronic Losartan Treatment Up-Regulates AT1R and Increases the Heart Vulnerability to Acute Onset of Ischemia and Reperfusion Injury in Male Rats.

    PubMed

    Song, Minwoo A; Dasgupta, Chiranjib; Zhang, Lubo

    2015-01-01

    Inhibition of angiotensin II type 1 receptor (AT1R) is an important therapy in the management of hypertension, particularly in the immediate post-myocardial infarction period. Yet, the role of AT1R in the acute onset of myocardial ischemia and reperfusion injury still remains controversial. Thus, the present study determined the effects of chronic losartan treatment on heart ischemia and reperfusion injury in rats. Losartan (10 mg/kg/day) was administered to six-month-old male rats via an osmotic pump for 14 days and hearts were then isolated and were subjected to ischemia and reperfusion injury in a Langendorff preparation. Losartan significantly decreased mean arterial blood pressure. However, heart weight, left ventricle to body weight ratio and baseline cardiac function were not significantly altered by the losartan treatment. Of interest, chronic in vivo losartan treatment significantly increased ischemia-induced myocardial injury and decreased post-ischemic recovery of left ventricular function. This was associated with significant increases in AT1R and PKCδ expression in the left ventricle. In contrast, AT2R and PKCε were not altered. Furthermore, losartan treatment significantly increased microRNA (miR)-1, -15b, -92a, -133a, -133b, -210, and -499 expression but decreased miR-21 in the left ventricle. Of importance, addition of losartan to isolated heart preparations blocked the effect of increased ischemic-injury induced by in vivo chronic losartan treatment. The results demonstrate that chronic losartan treatment up-regulates AT1R/PKCδ and alters miR expression patterns in the heart, leading to increased cardiac vulnerability to ischemia and reperfusion injury.

  9. The Use of the 'Preclosure' Technique for Antegrade Aspiration Thrombectomy with Large Catheters in Acute Limb Ischemia

    SciTech Connect

    Funke, C. Pfiffner, R.; Husmann, M.; Pfammatter, T.

    2013-04-15

    This study was designed to assess retrospectively short- and mid-term outcomes of the use of a suture-mediated closure device to close the antegrade access in patients undergoing percutaneous aspiration thrombectomy with large catheters for acute leg ischemia. Between November 2005 and February 2010, a suture-mediated active closure system (ProGlide{sup Registered-Sign} 6F, Abbott) was placed before arterial sheath (mean 9 F, range 6-12 F) introduction in 101 patients (74 men, 73 %, mean age 70.1 {+-} 12.6 years standard deviation). Data regarding mortality, complications, and factors contributing to vascular complications at the access site was collected for 6 month after the intervention to detect device-related problems. As a coincidence, 77 patients had follow-up visits for a duplex ultrasound. There were a total of 19 vascular complications (19 %) at the puncture site, all of which were of hemorrhagic nature and none of which consisted of vessel occlusion. Two major outcome complications (2 %) occurred. A retroperitoneal hematoma and a serious inguinal bleeding required additive treatment and did not result in permanent sequelae. Nine cases involved death of which eight were not attributable to the closure and one remained unclear. Successful closure was achieved in 95 patients (94 %); additional manual compression was sufficient in the majority of the remaining patients. Numerous factors contributing to vascular complications were encountered. With acceptable short- and mid-term outcomes, the 'preclose' technique can be a reliable option for the closure of a large antegrade femoral access even for patients at a high risk of vascular complications, such as those undergoing aspiration thrombectomy.

  10. Inhibition of CD34+ cell migration by matrix metalloproteinase-2 during acute myocardial ischemia, counteracted by ischemic preconditioning

    PubMed Central

    Lukovic, Dominika; Zlabinger, Katrin; Gugerell, Alfred; Spannbauer, Andreas; Pavo, Noemi; Mandic, Ljubica; Weidenauer, Denise T.; Kastl, Stefan; Kaun, Christoph; Posa, Aniko; Sabdyusheva Litschauer, Inna; Winkler, Johannes; Gyöngyösi, Mariann

    2017-01-01

    Background. Mobilization of bone marrow-origin CD34+ cells was investigated 3 days (3d) after acute myocardial infarction (AMI) with/without ischemic preconditioning (IP) in relation to stromal-derived factor-1 (SDF-1α)/ chemokine receptor type 4 (CXCR4) axis, to search for possible mechanisms behind insufficient cardiac repair in the first days post-AMI.  Methods. Closed-chest reperfused AMI was performed by percutaneous balloon occlusion of the mid-left anterior descending (LAD) coronary artery for 90min, followed by reperfusion in pigs. Animals were randomized to receive either IP initiated by 3x5min cycles of re-occlusion/re-flow prior to AMI (n=6) or control AMI (n=12). Blood samples were collected at baseline, 3d post-AMI, and at 1-month follow-up to analyse chemokines and mobilized CD34+ cells. To investigate the effect of acute hypoxia, SDF-1α and matrix metalloproteinase (MMP)-2 in vitro were assessed, and a migration assay of CD34+ cells toward cardiomyocytes was performed.  Results. Reperfused AMI induced significant mobilisation of CD34+ cells (baseline: 260±75 vs. 3d: 668±180; P<0.001) and secretion of MMP-2 (baseline: 291.83±53.40 vs. 3d: 369.64±72.89; P=0.011) into plasma, without affecting the SDF-1α concentration. IP led to the inhibition of MMP-2 (IP: 165.67±47.99 vs. AMI: 369.64±72.89; P=0.004) 3d post-AMI, accompanied by increased release of SDF-1α (baseline: 23.80±12.36 vs. 3d: 45.29±11.31; P=0.05) and CXCR4 (baseline: 0.59±0.16 vs. 3d: 2.06±1.42; P=0.034), with a parallel higher level of mobilisation of CD34+ cells (IP: 881±126 vs. AMI: 668±180; P=0.026), compared to non-conditioned AMI. In vitro, CD34+ cell migration toward cardiomyocytes was enhanced by SDF-1α, which was completely abolished by 90min hypoxia and co-incubation with MMP-2.  Conclusions. Non-conditioned AMI induces MMP-2 release, hampering the ischemia-induced increase in SDF-1α and CXCR4 by cleaving the SDF-1α/CXCR4 axis, with diminished mobilization of

  11. [Acute ischemia of an arm as an unusual manifestation of ergotism].

    PubMed

    Heinz, M; Theiss, W; Golder, W; Schömig, A

    1994-11-04

    A 27-year-old woman developed acute pain, pallor and feeling of cold in her left arm. She had been a smoker of 15-20 cigarettes daily since the age of 15 years, but had not previously had any serious illness. In addition to contraceptives she had had been taking one to several suppositories containing caffeine and ergotamine tartrate (2 mg) daily against migraine. Angiological examination 5 days after onset of symptoms discovered a weak brachial pulse low in the left upper arm, while ulnar and radial pulses were absent. All other pulses were normally palpable. Colour duplex sonography demonstrated occlusion of the brachial artery which angiographically was due to a 5 cm severe narrowing without thrombus, blood flowing distally via collaterals. No improvement was achieved by local injection of 100,000 IU urokinase, 0.5 mg nitroglycerin, 20 mg tolazoline and a 3-hour infusion of alprostadil. On infusion of 560 ml hydroxyethylstarch over 8 hours, 400 mg naftidrofuryl, therapeutic doses of heparin and abstinence from ergotamine (since admission) the vessel diameter increased by 50% within 23 hours and after a further 24 hours to almost 100% of the comparable arterial segment of the right arm while merely on heparin infusion.

  12. Ischemia-Modified Albumin as a Marker of Acute Coronary Syndrome: The Case for Revising the Concept of "N-Terminal Modification" to "Fatty Acid Occupation" of Albumin.

    PubMed

    Oran, Ismail; Oran, Bulent

    2017-01-01

    Ischemia-modified albumin (IMA) is assumed "N-terminal modified" albumin which is generated immediately following myocardial ischemia. The diagnosis of IMA is based on reduced cobalt binding affinity to albumin which is attributed mainly to incapability of cobalt to bind at albumin's modified N-terminus. Although the albumin cobalt binding test was accepted as a potentially powerful marker for discriminating acute coronary syndrome from nonischemic chest pain, its usefulness has been brought into question in recent years. Patients with acutely ischemic myocardium exhibit a rapid increase in serum levels of fatty acids (FAs). Almost all released FAs are strongly bound to albumin which create conformational changes in the protein with resultant reduced cobalt binding affinity. There is a clear metabolic and temporal relationship between IMA measured via albumin cobalt binding testing and serum levels of FAs. In line with what has been suggested recently in the literature, we conclude that a shift from the concept of "N-terminal modified" to "FA-occupied" albumin is required, as this better describes IMA in patients with acute coronary syndrome. We also offer "oxidation modified albumin, OMA," which is conceptually different from the "FA-occupied" IMA, to describe modification of albumin in chronic disease associated with increased oxidative stress.

  13. The new P2Y-like receptor G protein-coupled receptor 17 mediates acute neuronal injury and late microgliosis after focal cerebral ischemia in rats.

    PubMed

    Zhao, B; Zhao, C Z; Zhang, X Y; Huang, X Q; Shi, W Z; Fang, S H; Lu, Y B; Zhang, W P; Xia, Q; Wei, E Q

    2012-01-27

    G protein-coupled receptor 17 (GPR17), the new P2Y-like receptor, is phylogenetically related to the P2Y and cysteinyl leukotriene receptors, and responds to both uracil nucleotides and cysteinyl leukotrienes. GPR17 has been proposed to be a damage sensor in ischemic stroke; however, its role in brain inflammation needs further detailed investigation. Here, we extended previous studies on the spatiotemporal profiles of GPR17 expression and localization, and their implications for brain injury after focal cerebral ischemia. We found that in the ischemic core, GPR17 mRNA and protein levels were upregulated at both 12-24 h and 7-14 days, but in the boundary zone the levels increased 7-14 days after reperfusion. The spatiotemporal pattern of GPR17 expression well matched the acute and late (subacute/chronic) responses in the ischemic brain. According to previous findings, in the acute phase, after ischemia (24 h), upregulated GPR17 was localized in injured neurons in the ischemic core and in a few microglia in the ischemic core and boundary zone. In the late phase (14 days), it was localized in microglia, especially in activated (ED1-positive) microglia in the ischemic core, but weakly in most microglia in the boundary zone. No GPR17 was detectable in astrocytes. GPR17 knockdown by a small interfering RNA attenuated the neurological dysfunction, infarction, and neuron loss at 24 h, and brain atrophy, neuron loss, and microglial activation at 14 days after reperfusion. Thus, GPR17 might mediate acute neuronal injury and late microgliosis after focal cerebral ischemia.

  14. Mild sensory stimulation re-establishes cortical function during the acute phase of ischemia

    PubMed Central

    Lay, Christopher C.; Davis, Melissa F.; Chen-Bee, Cynthia H.; Frostig, Ron D.

    2011-01-01

    When delivered within 1 and in most cases 2 hours of permanent middle cerebral artery occlusion (pMCAO), mild sensory stimulation (intermittent single whisker stimulation) was shown to be completely neuroprotective according to assessment with multiple techniques 24 hours after pMCAO in a rodent model of ischemic stroke (Lay et al., 2010). The acute effect of stimulation treatment on the ischemic cortex however, had yet to be reported. Here we characterize cortical function and perfusion during the 120 minute whisker stimulation period in four experimental groups with treatment initiated 0, 1, 2 hours (protected groups) or 3 hours post-pMCAO (unprotected group) using multiple techniques. According to functional imaging, a gradual return of evoked whisker functional representation to baseline levels was initiated with treatment onset and completed within the treatment period. Evoked neuronal activity and reperfusion to the ischemic area also showed a gradual recovery in protected animals. Surprisingly, a similar recovery profile was observed in response to treatment in all protected animals, irrespective of treatment onset time. Non-stimulated pMCAO control group data demonstrate that reperfusion is not spontaneous. This makes the complete protection observed in the majority of animals stimulated at 2 hours post-pMCAO even more surprising as these animals recovered despite having been in this severely ischemic state for two full hours. In summary, when delivered within a 2 hour window post- pMCAO, whisker stimulation treatment initiated reperfusion and a gradual recovery of cortical function that was completed or nearly completed within the treatment period. PMID:21832179

  15. The neuroprotective effect of hyperbaric oxygen treatment on laser-induced retinal damage in rats

    NASA Astrophysics Data System (ADS)

    Vishnevskia-Dai, Victoria; Belokopytov, Mark; Dubinsky, Galina; Nachum, Gal; Avni, Isaac; Belkin, Michael; Rosner, Mordechai

    2005-04-01

    Retinal damage induced by mechanical trauma, ischemia or laser photocoagulation increases considerably by secondary degeneration processes. The spread of damage may be ameliorated by neuroprotection that is aimed at reducing the extent of the secondary degeneration and promote healing processes. Hyperbaric oxygen (HBO) treatment consists of inspiration of oxygen at higher than one absolute atmospheric pressure. Improved neural function was observed in patients with acute brain trauma or ischemia treated with HBO. This study was designed to evaluate the neuroprotective effect of hyperbaric oxygen (HBO) on laser induced retinal damage in a rat model. Standard argon laser lesions were created in 25 pigmented rats divided into three groups: Ten rats were treated immediately after the irradiation with HBO three times during the first 24 hr followed by 12 consecutive daily treatments. Five rats received a shorter treatment regimen of 10 consecutive HBO treatments. The control group (10 rats) underwent the laser damage with no additional treatment. The retinal lesions were evaluated 20 days after the injury. All outcome measures were improved by the longer HBO treatment (P<0.01). The shorter HBO treatment was less effective, showing an increase only in nuclei density at the central area of lesion (P< 0.01). Hyperbaric oxygen seems to exert a neuroprotective effect on laser-induced retinal damage in a rat model. In the range of HBO exposures studied, longer exposure provides more neuroprotection. These results encourage further evaluation of the potential therapeutic use of hyperbaric oxygen in diseases and injuries of the retina.

  16. Endoplasmic reticulum stress-regulated CXCR3 pathway mediates inflammation and neuronal injury in acute glaucoma.

    PubMed

    Ha, Y; Liu, H; Xu, Z; Yokota, H; Narayanan, S P; Lemtalsi, T; Smith, S B; Caldwell, R W; Caldwell, R B; Zhang, W

    2015-10-08

    Acute glaucoma is a leading cause of irreversible blindness in East Asia. The mechanisms underlying retinal neuronal injury induced by a sudden rise in intraocular pressure (IOP) remain obscure. Here we demonstrate that the activation of CXCL10/CXCR3 axis, which mediates the recruitment and activation of inflammatory cells, has a critical role in a mouse model of acute glaucoma. The mRNA and protein expression levels of CXCL10 and CXCR3 were significantly increased after IOP-induced retinal ischemia. Blockade of the CXCR3 pathway by deleting CXCR3 gene significantly attenuated ischemic injury-induced upregulation of inflammatory molecules (interleukin-1β and E-selectin), inhibited the recruitment of microglia/monocyte to the superficial retina, reduced peroxynitrite formation, and prevented the loss of neurons within the ganglion cell layer. In contrast, intravitreal delivery of CXCL10 increased leukocyte recruitment and retinal cell apoptosis. Inhibition of endoplasmic reticulum (ER) stress with chemical chaperones partially blocked ischemic injury-induced CXCL10 upregulation, whereas induction of ER stress with tunicamycin enhanced CXCL10 expression in retina and primary retinal ganglion cells. Interestingly, deleting CXCR3 attenuated ER stress-induced retinal cell death. In conclusion, these results indicate that ER stress-medicated activation of CXCL10/CXCR3 pathway has an important role in retinal inflammation and neuronal injury after high IOP-induced ischemia.

  17. Radiological Evaluation of Bowel Ischemia

    PubMed Central

    Dhatt, Harpreet S.; Behr, Spencer C; Miracle, Aaron; Wang, Zhen Jane; Yeh, Benjamin M.

    2015-01-01

    Intestinal ischemia, which refers to insufficient blood flow to the bowel, is a potentially catastrophic entity that may require emergent intervention or surgery in the acute setting. Although the clinical signs and symptoms of intestinal ischemia are nonspecific, CT findings can be highly suggestive in the correct clinical setting. In this chapter we review the CT diagnosis of arterial, venous, and non-occlusive intestinal ischemia. We discuss the vascular anatomy, pathophysiology of intestinal ischemia, CT techniques for optimal imaging, key and ancillary radiological findings, and differential diagnosis. In the setting of an acute abdomen, rapid evaluation is necessary to identify intraabdominal processes that require emergent surgical intervention (1). While a wide-range of intraabdominal diseases may be present from trauma to inflammation, one of the most feared disorders is mesenteric ischemia, also known as intestinal ischemia, which refers to insufficient blood flow to the bowel (2). Initial imaging evaluation for intestinal ischemia is typically obtained with CT. Close attention to technique and search for key radiologic features with relation to the CT technique is required. Accurate diagnosis depends on understanding the vascular anatomy, epidemiology, and pathophysiology of various forms of mesenteric ischemia and their corresponding radiological findings on MDCT. At imaging, not only is inspection of the bowel itself important, but evaluation of the mesenteric fat, vasculature, and surrounding peritoneal cavity also helps improves accuracy in the diagnosis of bowel ischemia. PMID:26526436

  18. No influence of acute RF exposure (GSM-900, GSM-1800, and UMTS) on mouse retinal ganglion cell responses under constant temperature conditions.

    PubMed

    Ahlers, Malte T; Ammermüller, Josef

    2014-01-01

    Possible non-thermal effects of radio frequency electromagnetic fields (RF-EMF) on retinal ganglion cells were studied in vitro under conditions of constant temperature. Isolated mouse retinae were exposed to GSM-900, GSM-1800, and universal mobile telecommunication system (UMTS) RF-EMF applying specific absorption rates (SAR) of 0 (sham), 0.02, 0.2, 2, and 20 W/kg. Temperature was kept constant within ±0.5 to 1 °C for GSM-900 and ±0.5 °C for GSM-1800 and UMTS. Responses of retinal ganglion cells to light stimuli of three intensities (0.5, 16, and 445 lx) were recorded before, during, and up to 35 min after exposure. Experiments were performed under double-blind conditions. Changes in light responses during and after exposure were determined for each condition (RF-EMF; SAR value; light intensity) with respect to the responses before exposure, respectively. Changes were calculated using the Euclidian distance of the n-dimensional response vectors, respectively. Some changes already occurred during sham (0 W/kg) exposure, reflecting the intrinsic variability in retinal ganglion cell responses. Comparison of the distance values from sham exposure with those from actual exposure yielded no significant differences. In addition, linear regression analysis of the distance values versus SAR values yielded no consistent dependence of light response changes. From these results we conclude that RF-EMF exposure at three mobile phone frequencies (GSM-900, GSM-1800, UMTS) and SARs up to 20 W/kg has no acute effects on retinal ganglion cell responses under constant temperature conditions.

  19. α-Aminoadipic acid protects against retinal disruption through attenuating Müller cell gliosis in a rat model of acute ocular hypertension

    PubMed Central

    Wang, Xiaolei; Su, Jier; Ding, Jingwen; Han, Song; Ma, Wei; Luo, Hong; Hughes, Guy; Meng, Zhaoyang; Yin, Yi; Wang, Yanling; Li, Junfa

    2016-01-01

    Objective Ocular hypertension is an important risk factor for glaucoma. The purpose of this study was to investigate the gliotoxic effects of α-aminoadipic acid (AAA) in a rat model of AOH and its underlying mechanisms. Materials and methods In the rat model of acute ocular hypertension (AOH), intraocular pressure was increased to 110 mmHg for 60 minutes. Animals were divided into four groups: sham operation (Ctrl), AOH, AOH + phosphate-buffered saline (PBS), and AOH + AAA. Cell apoptosis in the ganglion cell layer was detected with the terminal deoxynucleotidyl transferase-mediated uridine 5′-triphosphate-biotin nick end labeling (TUNEL) assay, and retinal ganglion cells (RGCs) immunostained with Thy-1 were counted. Müller cell activation was detected using immunostaining with glutamine synthetase and glial fibrillary acidic protein. Tumor necrosis factor-α (TNF-α) was examined using Western blot. Results In the rat model of AOH, cell apoptosis was induced in the ganglion cell layer and the number of RGCs was decreased. Müller cell gliosis in the retinas of rats was induced, and retinal protein levels of TNF-α were increased. Intravitreal treatment of AAA versus PBS control attenuated these retinal abnormalities to show protective effects in the rat model of AOH. Conclusion In the retinas of the rat model of AOH, AAA treatment attenuated retinal apoptosis in the ganglion cell layer and preserved the number of RGCs, likely through the attenuation of Müller cell gliosis and suppression of TNF-α induction. Our observations suggest that AAA might be a potential therapeutic target in glaucoma. PMID:27799744

  20. Acute Mesenteric Ischemia

    MedlinePlus

    ... the Professional Version Also of Interest Test your knowledge Clostridium difficile -induced colitis is an inflammation of ... Learn more about our commitment to Global Medical Knowledge . Merck Manuals About Disclaimer Permissions Privacy Contributors Terms ...

  1. Factors Associated with the Retinal Nerve Fiber Layer Loss after Acute Primary Angle Closure: A Prospective EDI-OCT Study

    PubMed Central

    Lee, Kyoung Min; Lee, Seung Hyen; Kim, Hyunjoong

    2017-01-01

    Purpose To determine the factors associated with retinal nerve fiber layer (RNFL) loss in eyes with acute primary angle-closure (APAC), particularly focusing on the influence of the change in the anterior lamina cribrosa surface depth (LCD). Methods After the initial presentation, 30 eyes with unilateral APAC were followed up at the following specific time points over a 12-month period: 1 week, 1~2 months, 2~3 months, 5~6 months, and 11~12 months. These follow-ups involved intraocular pressure measurements, enhanced depth-imaging spectral-domain optical coherence tomography (SD-OCT) scanning of the optic disc, and measurements of the circumpapillary RNFL thickness. The prelaminar tissue thickness (PLT) and LCD were determined in the SD-OCT images obtained at each follow-up visit. Results Repeated measures analysis of variance revealed a significant pattern of decrease in the global RNFL thickness, PLT, and LCD (all p<0.001). The global RNFL thickness decreased continuously throughout the follow-up period, while the PLT decreased until 5~6 months and did not change thereafter. The LCD reduced until 2~3 months and then also remained steady. Multivariable regression analysis revealed that symptoms with a longer duration before receiving laser peripheral iridotomy (LI) (p = 0.049) and a larger LCD reduction (p = 0.034) were significant factors associated with the conversion to an abnormal RNFL thickness defined using OCT normative data. Conclusion Early short-term decreases in the PLT and LCD and overall long-term decrease in the peripapillary RNFL were observed during a 12-month follow-up after an APAC episode. A longer duration of symptoms before receiving LI treatment and larger LCD reduction during follow-up were associated with the progressive RNFL loss. The LCD reduction may indicate a prior presence of significant pressure-induced stress that had been imposed on the optic nerve head at the time of APAC episode. Glaucomatous progression should be suspected in

  2. Cross-sectional study of the retinal nerve fiber layer thickness at 7 years after an acute episode of unilateral primary acute angle closure.

    PubMed

    Lee, Jacky W Y; Woo, Tiffany T Y; Yau, Gordon S K; Yip, Stan; Yick, Doris W F; Wong, Jasper; Wong, Raymond L M; Wong, Ian Y H

    2015-01-01

    The purpose of this article is to investigate the long-term retinal nerve fiber layer (RNFL) status and determinants of RNFL thinning after an episode of unilateral primary acute angle closure (AAC). This cross-sectional study analyzed the medical records of consecutive patients with a single episode of unilateral AAC from 1999 to 2009 in Hong Kong. The peripapillary RNFL thickness was correlated with age, gender, presenting intraocular pressure (IOP), time to laser iridotomy, time to cataract extraction, follow-up duration, as well as the last IOP, vertical cup-to-disc ratio (CDR), and vision. The fellow uninvolved eye was used as a proxy comparison of RNFL loss in the attack eye. In 40 eligible patients, the mean age was 68.3 ± 8.7 years with a male-to-female ratio of 1:7. The mean presenting IOP was 49.2 ± 14.0 mm Hg and the time from presentation to laser iridotomy was 6.7 ± 6.9 days. Forty percent of subjects received a cataract extraction at 3.2 ± 2.9 years after the attack. The last IOP, CDR, and LogMAR vision were 16.0 ± 3.8 mm Hg, 0.6 ± 0.2, and 0.6 ± 0.6 LogMAR units, respectively, at 7.9 ± 2.4 years. The RNFL thickness in the attack eye (69.2 ± 19.1 μm) was 25.2 ± 17.9% thinner than the fellow eye (93.0 ± 17.8 μm) at 7.5 ± 2.9 years post-AAC. Using univariate analysis, the last vertical CDR (odds ratio [OR] = 17.2, P = 0.049) and LogMAR visual acuity (VA) (OR = 6.6, P = 0.03) were the only significant predictors for RNFL thinning whereas none of the other covariates showed significant associations (P > 0.1). At 7.5 years following unilateral AAC, the RNFL thickness was 25% thinner than the fellow eye. CDR enlargement and poor VA were the only significant predictors for RNFL loss.

  3. ASSESSMENT OF VISUAL FUNCTION AND RETINAL STRUCTURE FOLLOWING ACUTE LIGHT EXPOSURE IN THE LIGHT SENSITIVE T4R RHODOPSIN MUTANT DOG

    PubMed Central

    Iwabe, Simone; Ying, Gui-Shuang; Aguirre, Gustavo D.; Beltran, William A.

    2016-01-01

    The effect of acute exposure to various intensities of white light on visual behavior and retinal structure was evaluated in the T4R RHO dog, a naturally-occurring model of autosomal dominant retinitis pigmentosa due to a mutation in the Rhodopsin gene. A total of 14 dogs (ages: 4–5.5 months) were used in this study: 3 homozygous mutant RHOT4R/T4R, 8 heterozygous mutant RHOT4R/+, and 3 normal wild-type (WT) dogs. Following overnight dark adaptation, the left eyes were acutely exposed to bright white light with a monocular Ganzfeld dome, while the contralateral right eye was shielded. Each of the 3 homozygous (RHOT4R/T4R) mutant dogs had a single unilateral light exposure (LE) to a different (low, moderate, and high) dose of white light (corneal irradiance/illuminance: 0.1 mW/cm2, 170 lux; 0.5 mW/cm2, 820 lux; or 1 mW/cm2, 1590 lux) for 1min. All 8 heterozygous (RHOT4R/+) mutant dogs were exposed once to the same moderate dose of light. The 3 WT dogs had their left eyes exposed 1, 2, or 3 times to the same highest dose of light. Visual function prior to LE and at 2 weeks and 33 weeks after exposure was objectively assessed in the RHOT4R/T4R and WT dogs by using an obstacle-avoidance course. Transit time through the obstacle course was measured under different scotopic to photopic ambient illuminations. Morphological retinal changes were evaluated by non-invasive in vivo cSLO/sdOCT imaging and histology before and at several time-points (2–36 weeks) after light exposure. The analysis of the transit time through the obstacle course showed that no differences were observed in any of mutant or WT dogs at 2 weeks and 33 weeks post LE. The RHOT4R/T4R retina exposed to the lowest dose of white light showed no obvious changes in ONL thickness at 2 weeks, but mild decrease was noted 36 weeks after LE. The RHOT4R/T4R retina that received a moderate dose (showed an obvious decrease in ONL thickness along the superior and temporal meridians at 2 weeks post LE with more

  4. Acute Hemorrhagic Retinopathy following Intravitreal Melphalan Injection for Retinoblastoma: A Report of Two Cases and Technical Modifications to Enhance the Prevention of Retinal Toxicity

    PubMed Central

    Aziz, Hassan A.; Kim, Jonathan W.; Munier, Francis L.; Berry, Jesse L.

    2017-01-01

    Aims To report the occurrence of acute hemorrhagic retinopathy following intravitreal melphalan injection for retinoblastoma. Methods This is a retrospective case series of 2 patients with retinoblastoma treated with intravitreal melphalan for vitreous seeding who developed acute hemorrhagic retinopathy. Results Patient 1 is a 6-month-old female with bilateral retinoblastoma (Group D right eye and Group B left eye) treated with 4 cycles of systemic chemotherapy and 2 intravitreal melphalan injections in each eye. Patient 2 is a 10-month-old male with unilateral Group D retinoblastoma treated with 6 cycles of systemic chemotherapy and 2 injections of intravitreal melphalan. At the 1-week follow-up after the second injection, both patients had an acute hemorrhagic retinopathy that resulted in chorioretinal toxicity with a sharp demarcation line between the normal and abnormal retina. At the last follow-up (22 and 12 months, respectively), there was total tumor control and resolution of vitreous seeding in both patients. Conclusions Although intravitreal melphalan injection is effective for vitreous seeding in eyes with retinoblastoma, acute hemorrhagic retinopathy and diffuse chorioretinal atrophy is a possible complication of this treatment modality. Given the clinical findings observed in these patients, the development of this retinal toxicity most likely results from a retrohyaloid overdose. Consequently we suggest preventive measures aimed at limiting the risk of retrohyaloid injection.

  5. Retinitis Pigmentosa.

    ERIC Educational Resources Information Center

    Carr, Ronald E.

    1979-01-01

    The author describes the etiology of retinitis pigmentosa, a visual dysfunction which results from progressive loss of the retinal photoreceptors. Sections address signs and symptoms, ancillary findings, heredity, clinical diagnosis, therapy, and research. (SBH)

  6. Retinitis pigmentosa

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/001029.htm Retinitis pigmentosa To use the sharing features on this page, please enable JavaScript. Retinitis pigmentosa is an eye disease in which there is ...

  7. Sex Differences in Mental Stress-Induced Myocardial Ischemia in Young Survivors of an Acute Myocardial Infarction

    PubMed Central

    Vaccarino, Viola; Shah, Amit J.; Rooks, Cherie; Ibeanu, Ijeoma; Nye, Jonathon A.; Pimple, Pratik; Salerno, Amy; D'Marco, Luis; Karohl, Cristina; Bremner, J. Douglas; Raggi, Paolo

    2014-01-01

    Objectives Emotional stress may disproportionally affect young women with ischemic heart disease. We sought to examine whether mental stress-induced myocardial ischemia (MSIMI), but not exercise-induced ischemia, is more common in young women with previous myocardial infarction (MI) than men. Methods We studied 98 post-MI patients (49 women and 49 men) aged 38-60 years. Women and men were matched for age, MI type, and months since MI. Patients underwent [99mTc]sestamibi perfusion imaging at rest, after mental stress, and after exercise/pharmacological stress. Perfusion defect scores were obtained with observer-independent software. A summed difference score (SDS), the difference between stress and rest scores, was used to quantify ischemia under both stress conditions. Results Women aged 50 or younger, but not older women, showed a more adverse psychosocial profile than age-matched men, but did not differ for conventional risk factors and tended to have less angiographic coronary artery disease (CAD). Compared with age-matched men, women aged 50 or younger exhibited a higher SDS with mental stress (3.1 vs. 1.5, p=0.029) and had twice the rate of MSIMI (SDS ≥3), 52% vs. 25%, while ischemia with physical stress did not differ (36% vs 25%). In older patients there were no sex differences in MSIMI. The higher prevalence of MSIMI in young women persisted when adjusting for sociodemographic and lifestyle factors, CAD severity and depression. Conclusions MSIMI post-MI is more common in women aged 50 or younger compared to age-matched men. These sex differences are not observed in post-MI patients who are older than 50 years. PMID:24608039

  8. Inhibition of P38 MAPK Downregulates the Expression of IL-1β to Protect Lung from Acute Injury in Intestinal Ischemia Reperfusion Rats

    PubMed Central

    Zheng, De-Yi; Zhou, Min; Jin, Jiao; He, Mu; Wang, Yi; Du, Jiao; Xiao, Xiang-Yang; Li, Ping-Yang; Ye, Ai-Zhu; Liu, Jia; Wang, Ting-Hua

    2016-01-01

    Acute lung injury (ALI) induced by intestinal ischemia/reperfusion (II/R) has high incidence and mortality, in which IL-1β was essential for the full development of ALI. However, the detailed regulating mechanism for this phenomenon remains to be unclear. The purpose of this study was to investigate whether inhibition of P38 MAPK could downregulate the expression of IL-1β to protect lung from acute injury in II/R rats. Here, we found that the level of pulmonary edema at 16 hours after operation (hpo) was obviously enhanced compared to that in 8hpo and sham groups. Immunofluorescent staining demonstrated that IL-1β and P38 MAPK were detected in lung tissues. And rats with II/R have the highest translation level for IL-1β and phosphorylation of P38 MAPK in lung tissues at 16hpo compared with 8hpo and sham groups. Moreover, administration of SB239063, an inhibitor of P38 α and β, could effectively downregulate the expressions of IL-1β and protects lung tissues from injury in II/R rats. Our findings indicate that the inhibition of P38 α and β may downregulate the expression of IL-1β to protect lung from acute injury in II/R, which could be used as a potential target for reducing ALI induced by II/R in the future clinical trial. PMID:26980948

  9. Retinal Detachment

    MedlinePlus

    ... men more than women and whites more than African Americans. A retinal detachment is also more likely to occur in people who Are extremely nearsighted Have had a retinal detachment in the other eye Have a family history of retinal detachment Have had cataract surgery Have ...

  10. A Novel Cardioprotective Agent in Cardiac Transplantation: Metformin Activation of AMP-Activated Protein Kinase Decreases Acute Ischemia-Reperfusion Injury and Chronic Rejection

    PubMed Central

    Chin, Jocelyn T.; Troke, Joshua J.; Kimura, Naoyuki; Itoh, Satoshi; Wang, Xi; Palmer, Owen P.; Robbins, Robert C.; Fischbein, Michael P.

    2011-01-01

    The main cause of mortality after the first year from cardiac transplantation is cardiac allograft vasculopathy (CAV), which leads to chronic rejection of the heart. To improve long-term outcomes in cardiac transplantation, treatments to prevent or diminish CAV are actively being researched. Ischemia-reperfusion (I-R) injury has been shown to be the strongest alloantigen-independent factor in the development of CAV. Here, we investigate the use of metformin in murine cardiac transplantation models as a novel cardioprotective agent to limit acute I-R injury and subsequent chronic rejection. We show that metformin treatment activates AMP-activated kinase (AMPK) in vitro and in vivo. In the acute transplantation model, metformin activation of AMPK resulted in significantly decreased apoptosis in cardiac allografts on postoperative day (POD) 1 and 8. In the chronic transplantation model, metformin pretreatment of allografts led to significantly improved graft function and significantly decreased CAV, as measured on POD 52. Taken together, our results in the acute and chronic rejection studies suggest a potential cardioprotective mechanism for metformin; we demonstrate a correlation between metformin-induced decrease in acute I-R injury and metformin-related decrease in chronic rejection. Thus, one of the ways by which metformin and AMPK activation may protect the transplanted heart from chronic rejection is by decreasing initial I-R injury inherent in donor organ preservation and implantation. Our findings suggest novel therapeutic strategies for minimizing chronic cardiac rejection via the use of metformin- and AMPK-mediated pathways to suppress acute I-R injury. PMID:22180679

  11. A novel cardioprotective agent in cardiac transplantation: metformin activation of AMP-activated protein kinase decreases acute ischemia-reperfusion injury and chronic rejection.

    PubMed

    Chin, Jocelyn T; Troke, Joshua J; Kimura, Naoyuki; Itoh, Satoshi; Wang, Xi; Palmer, Owen P; Robbins, Robert C; Fischbein, Michael P

    2011-12-01

    The main cause of mortality after the first year from cardiac transplantation is cardiac allograft vasculopathy (CAV), which leads to chronic rejection of the heart. To improve long-term outcomes in cardiac transplantation, treatments to prevent or diminish CAV are actively being researched. Ischemia-reperfusion (I-R) injury has been shown to be the strongest alloantigen-independent factor in the development of CAV. Here, we investigate the use of metformin in murine cardiac transplantation models as a novel cardioprotective agent to limit acute I-R injury and subsequent chronic rejection. We show that metformin treatment activates AMP-activated kinase (AMPK) in vitro and in vivo. In the acute transplantation model, metformin activation of AMPK resulted in significantly decreased apoptosis in cardiac allografts on postoperative day (POD) 1 and 8. In the chronic transplantation model, metformin pretreatment of allografts led to significantly improved graft function and significantly decreased CAV, as measured on POD 52. Taken together, our results in the acute and chronic rejection studies suggest a potential cardioprotective mechanism for metformin; we demonstrate a correlation between metformin-induced decrease in acute I-R injury and metformin-related decrease in chronic rejection. Thus, one of the ways by which metformin and AMPK activation may protect the transplanted heart from chronic rejection is by decreasing initial I-R injury inherent in donor organ preservation and implantation. Our findings suggest novel therapeutic strategies for minimizing chronic cardiac rejection via the use of metformin- and AMPK-mediated pathways to suppress acute I-R injury.

  12. Renoprotective effect of paricalcitol via a modulation of the TLR4-NF-κB pathway in ischemia/reperfusion-induced acute kidney injury

    SciTech Connect

    Lee, Jae-Won Kim, Sun Chul Ko, Yoon Sook Lee, Hee Young Cho, Eunjung Kim, Myung-Gyu Jo, Sang-Kyung Cho, Won Yong Kim, Hyoung Kyu

    2014-02-07

    Highlights: • Paricalcitol. • Attenuation of renal inflammation. • Modulation of TLR4-NF-κB signaling. - Abstract: Background: The pathophysiology of ischemic acute kidney injury (AKI) is thought to include a complex interplay between vascular endothelial cell dysfunction, inflammation, and tubular cell damage. Several lines of evidence suggest a potential anti-inflammatory effect of vitamin D in various kidney injury models. In this study, we investigated the effect of paricalcitol, a synthetic vitamin D analog, on renal inflammation in a mouse model of ischemia/reperfusion (I/R) induced acute kidney injury (AKI). Methods: Paricalcitol was administered via intraperitoneal (IP) injection at 24 h before ischemia, and then I/R was performed through bilateral clamping of the renal pedicles. Twenty-four hours after I/R, mice were sacrificed for the evaluation of injury and inflammation. Additionally, an in vitro experiment using HK-2 cells was also performed to examine the direct effect of paricalcitol on tubular cells. Results: Pre-treatment with paricalcitol attenuated functional deterioration and histological damage in I/R induced AKI, and significantly decreased tissue neutrophil and macrophage infiltration and the levels of chemokines, the pro-inflammatory cytokine interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1). It also decreased IR-induced upregulation of Toll-like receptor 4 (TLR4), and nuclear translocation of p65 subunit of NF-κB. Results from the in vitro study showed pre-treatment with paricalcitol suppressed the TNF-α-induced depletion of cytosolic IκB in HK-2 cells. Conclusion: These results demonstrate that pre-treatment with paricalcitol has a renoprotective effect in ischemic AKI, possibly by suppressing TLR4-NF-κB mediated inflammation.

  13. Impact of acute propranolol administration on dobutamine-induced myocardial ischemia as evaluated by myocardial perfusion imaging and echocardiography.

    PubMed

    Shehata, A R; Gillam, L D; Mascitelli, V A; Herman, S D; Ahlberg, A W; White, M P; Chen, C; Waters, D D; Heller, G V

    1997-08-01

    Beta-blocker therapy may delay or completely prevent myocardial ischemia during exercise testing, as assessed by ST-segment shifts, myocardial perfusion defects, or echocardiographic wall motion abnormalities. However, the impact of beta-blocker therapy on these end points during dobutamine stress testing has not been well established. The purpose of this study was to determine the impact of propranolol on dobutamine stress testing with ST-segment monitoring, technetium-99m (Tc-99m) sestamibi single-photon emission computed tomography (SPECT) imaging, and echocardiography. In 17 patients with known reversible perfusion defects, dobutamine stress tests with and without propranolol were performed in randomized order and on separate days, following discontinuation of oral beta blockers and calcium antagonists. Propronolol was administered intravenously to a cumulative dose of 8 mg or to a maximum heart rate reduction of 25% and dobutamine was infused in graded doses in 3 minute stages until a standard clinical end point or the maximum dose of 40 microg/kg/min was achieved. The dobutamine stress test after propranolol was associated with a lower maximum heart rate (83 +/- 18 vs 125 +/- 17, p <0.001) and rate pressure product (14,169 +/- 4,248 vs 19,894 +/- 3,985, p <0.001) despite a higher infusion dose. The SPECT myocardial ischemia score was also lower (6.9 +/- 5.8 vs 10.1 +/- 7.1, p = 0.047) and fewer echocardiographic segments were abnormal (3.4 +/- 3.0 vs 4.6 +/- 3.4, p = 0.042). In 4 of 17 patients, reversible perfusion defects and echocardiographic wall motion abnormalities were detected during the control but not during the propranolol test. Thus, during dobutamine stress testing, beta-blocker therapy attenuates, and in some cases eliminates, evidence of myocardial ischemia.

  14. Comparison of human adipose stromal vascular fraction and adipose-derived mesenchymal stem cells for the attenuation of acute renal ischemia/reperfusion injury

    PubMed Central

    Zhou, Liuhua; Song, Qun; Shen, Jiangwei; Xu, Luwei; Xu, Zheng; Wu, Ran; Ge, Yuzheng; Zhu, Jiageng; Wu, Jianping; Dou, Quanliang; Jia, Ruipeng

    2017-01-01

    Stem cells therapy has been suggested as a promising option for the treatment of acute kidney injury (AKI). This study was performed to compare the abilities of xenogenic transplantation of human adipose stromal vascular fraction (SVF) and adipose-derived mesenchymal stem cells (AdMSCs) to facilitate the recovery of renal function and structure in a rat model of ischemia/reperfusion (IR) induced AKI. SVF or AdMSCs were transplanted to the injured kidney through intra-parenchymal injection. Significantly improved renal function and reduced tubular injury were observed in SVF and AdMSCs groups. Administration of SVF or AdMSCs contributed to significantly improved cell proliferation and markedly reduced cell apoptosis in parallel with reduced microvascular rarefaction in injured kidney. IR injury resulted in higher levels of inflammatory cytokines, whereas xenogenic transplantation of SVF or AdMSCs reduced but not induced inflammatory cytokines expression. Additionally, in vitro study showed that administration of SVF or AdMSCs could also significantly promote the proliferation and survival of renal tubular epithelial cells underwent hypoxia/reoxygenation injury through secreting various growth factors. However, cell proliferation was significantly promoted in SVF group than in AdMSCs group. In conclusion, our study demonstrated that administration of SVF or AdMSCs was equally effective in attenuating acute renal IR injury. PMID:28276451

  15. NAP prevents acute cerebral oxidative stress and protects against long-term brain injury and cognitive impairment in a model of neonatal hypoxia-ischemia.

    PubMed

    Greggio, Samuel; de Paula, Simone; de Oliveira, Iuri M; Trindade, Cristiano; Rosa, Renato M; Henriques, João A P; DaCosta, Jaderson C

    2011-10-01

    Hypoxia-ischemia (HI) is a common cause of neonatal brain damage with lifelong morbidities in which current therapies are limited. In this study, we investigated the effect of neuropeptide NAP (NAPVSIPQ) on early cerebral oxidative stress, long-term neurological function and brain injury after neonatal HI. Seven-day-old rat pups were subjected to an HI model by applying a unilateral carotid artery occlusion and systemic hypoxia. The animals were randomly assigned to groups receiving an intraperitoneal injection of NAP (3 μg/g) or vehicle immediately (0 h) and 24 h after HI. Brain DNA damage, lipid peroxidation and reduced glutathione (GSH) content were determined 24 h after the last NAP injection. Cognitive impairment was assessed on postnatal day 60 using the spatial version of the Morris water maze learning task. Next, the animals were euthanized to assess the cerebral hemispheric volume using the Cavalieri principle associated with the counting point method. We observed that NAP prevented the acute HI-induced DNA and lipid membrane damage and also recovered the GSH levels in the injured hemisphere of the HI rat pups. Further, NAP was able to prevent impairments in learning and long-term spatial memory and to significantly reduce brain damage up to 7 weeks following the neonatal HI injury. Our findings demonstrate that NAP confers potent neuroprotection from acute brain oxidative stress, long-term cognitive impairment and brain lesions induced by neonatal HI through, at least in part, the modulation of the glutathione-mediated antioxidant system.

  16. Mast-cell-releasing tryptase triggers acute lung injury induced by small intestinal ischemia-reperfusion by activating PAR-2 in rats.

    PubMed

    Gan, Xiaoliang; Liu, Dezhao; Huang, Pinjie; Gao, Wanling; Chen, Xinzhi; Hei, Ziqing

    2012-06-01

    Mast cell has been demonstrated to be involved in the small intestinal ischemia-reperfusion (IIR) injury, however, the precise role of tryptase released from mast cell on acute lung injury(ALI) induced by IIR remains to be elucidated, our study aimed to observe the roles of tryptase on ALI triggered by IIR and its underlying mechanism. Adult SD rats were randomized into sham-operated group, sole IIR group in which rats were subjected to 75 min superior mesenteric artery occlusion followed by 4 h reperfusion, or IIR being respectively treated with cromolyn sodium, protamine, and compound 48/80. The above agents were, respectively, administrated intravenously 5 min before reperfusion. At the end of experiment, lung tissue was obtained for assays for protein expressions of tryptase and mast cell protease 7 (MCP7) and protease-activated receptor 2 (PAR-2). Pulmonary mast cell number and levels of IL-8 were quantified. Lung histologic injury scores and lung water content were measured. IIR resulted in lung injury evidenced as significant increases in lung histological scores and lung water contents, accompanied with concomitant increases of expressions of tryptase and MCP7, and elevations in PAR-2 expressions and IL-8 levels in lungs. Stabilizing mast cell with cromolyn sodium and inhibiting tryptase with protamine significantly reduced IIR-mediated ALI and the above biochemical changes while activating mast cell with compound 48/80 further aggravated IIR-mediated ALI and the increases of above parameters. Tryptase released from mast cells mediates ALI induced by intestinal ischemia-reperfusion by activating PAR-2 to produce IL-8.

  17. Effects of captopril, telmisartan and bardoxolone methyl (CDDO-Me) in ischemia-reperfusion-induced acute kidney injury in rats: an experimental comparative study.

    PubMed

    Kocak, Cengiz; Kocak, Fatma Emel; Akcilar, Raziye; Bayat, Zeynep; Aras, Bekir; Metineren, Mehmet Huseyin; Yucel, Mehmet; Simsek, Hasan

    2016-02-01

    Renal ischemia-reperfusion (IR) injury is one of the most common causes of acute kidney injury. This study investigated the effects of captopril (CAP), telmisartan (TEL) and bardoxolone methyl (BM) in animals with renal IR injury. Adult male Wistar-Albino rats were divided into six groups: control, vehicle, IR, IR with CAP, IR with TEL and IR with BM. Before IR was induced, drugs were administered by oral gavage. After a 60-min ischemia and a 120-min reperfusion period, bilateral nephrectomies were performed. Serum urea, creatinine, neutrophil gelatinase-associated lipocalin (NGAL) levels, tissue total oxidant status (TOS), total antioxidant status (TAS), total thiol (TT), asymmetric dimethylarginine (ADMA) levels, superoxide dismutase (SOD) activity and glutathione peroxidase (GSH-Px) activity were measured. Tissue mRNA expression levels of peroxisome proliferator-activated receptor-ɣ (PPAR-ɣ), nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) were analyzed. In addition, renal tissues were evaluated histopathologically and immunohistochemically. All tested drugs reduced renal damage, apoptosis, urea, creatinine, NGAL, TOS, nitric oxide (NO) and ADMA levels, NF-κB, inducible nitric oxide synthase (iNOS) and endothelin-1 (ET-1) expressions (P < 0.001). All tested drugs increased SOD activity, GSH-Px activity, TAS levels, TT levels, endothelial nitric oxide synthase (eNOS) expression, dimethylarginine dimethylaminohydrolases (DDAHs) expression, Nrf2 expression and PPAR-ɣ expression (P < 0.001, P < 0.003). These results suggest that CAP, TEL and BM pretreatment could reduce renal IR injury via anti-inflammatory, antioxidant and anti-apoptotic effects.

  18. Human Alpha-1-Antitrypsin (hAAT) therapy reduces renal dysfunction and acute tubular necrosis in a murine model of bilateral kidney ischemia-reperfusion injury

    PubMed Central

    Maicas, Nuria; van der Vlag, Johan; Bublitz, Janin; Florquin, Sandrine; Bakker-van Bebber, Marinka; Dinarello, Charles A.; Verweij, Vivienne; Masereeuw, Roos; Joosten, Leo A.

    2017-01-01

    Several lines of evidence have demonstrated the anti-inflammatory and cytoprotective effects of alpha-1-antitrypsin (AAT), the major serum serine protease inhibitor. The aim of the present study was to investigate the effects of human AAT (hAAT) monotherapy during the early and recovery phase of ischemia-induced acute kidney injury. Mild renal ischemia-reperfusion (I/R) injury was induced in male C57Bl/6 mice by bilateral clamping of the renal artery and vein for 20 min. hAAT (80 mg/kg, Prolastin®) was administered daily intraperitoneally (i.p.) from day -1 until day 7 after surgery. Control animals received the same amount of human serum albumin (hAlb). Plasma, urine and kidneys were collected at 2h, 1, 2, 3, 8 and 15 days after reperfusion for histological and biochemical analysis. hAAT partially preserved renal function and tubular integrity after induction of bilateral kidney I/R injury, which was accompanied with reduced renal influx of macrophages and a significant decrease of neutrophil gelatinase-associated lipocalin (NGAL) protein levels in urine and plasma. During the recovery phase, hAAT significantly decreased kidney injury molecule-1 (KIM-1) protein levels in urine but showed no significant effect on renal fibrosis. Although the observed effect size of hAAT administration was limited and therefore the clinical relevance of our findings should be evaluated carefully, these data support the potential of this natural protein to ameliorate ischemic and inflammatory conditions. PMID:28235038

  19. Effects of Valproic Acid and Dexamethasone Administration on Early Bio-Markers and Gene Expression Profile in Acute Kidney Ischemia-Reperfusion Injury in the Rat

    PubMed Central

    Speir, Ryan W.; Stallings, Jonathan D.; Andrews, Jared M.; Gelnett, Mary S.; Brand, Timothy C.; Salgar, Shashikumar K.

    2015-01-01

    Renal ischemia-reperfusion (IR) causes acute kidney injury (AKI) with high mortality and morbidity. The objective of this investigation was to ameliorate kidney IR injury and identify novel biomarkers for kidney injury and repair. Under general anesthesia, left renal ischemia was induced in Wister rats by occluding renal artery for 45 minutes, followed by reperfusion and right nephrectomy. Thirty minutes prior to ischemia, rats (n = 8/group) received Valproic Acid (150 mg/kg; VPA), Dexamethasone (3 mg/kg; Dex) or Vehicle (saline) intraperitoneally. Animals were sacrificed at 3, 24 or 120 h post-IR. Plasma creatinine (mg/dL) at 24 h was reduced (P<0.05) in VPA (2.7±1.8) and Dex (2.3±1.2) compared to Vehicle (3.8±0.5) group. At 3 h, urine albumin (mg/mL) was higher in Vehicle (1.47±0.10), VPA (0.84±0.62) and Dex (1.04±0.73) compared to naïve (uninjured/untreated control) (0.14±0.26) group. At 24 h post-IR urine lipocalin-2 (μg/mL) was higher (P<0.05) in VPA, Dex and Vehicle groups (9.61–11.36) compared to naïve group (0.67±0.29); also, kidney injury molecule-1 (KIM-1; ng/mL) was higher (P<0.05) in VPA, Dex and Vehicle groups (13.7–18.7) compared to naïve group (1.7±1.9). Histopathology demonstrated reduced (P<0.05) ischemic injury in the renal cortex in VPA (Grade 1.6±1.5) compared to Vehicle (Grade 2.9±1.1). Inflammatory cytokines IL1β and IL6 were downregulated and anti-apoptotic molecule BCL2 was upregulated in VPA group. Furthermore, kidney DNA microarray demonstrated reduced injury, stress, and apoptosis related gene expression in the VPA administered rats. VPA appears to ameliorate kidney IR injury via reduced inflammatory cytokine, apoptosis/stress related gene expression, and improved regeneration. KIM-1, lipocalin-2 and albumin appear to be promising early urine biomarkers for the diagnosis of AKI. PMID:25970334

  20. Learning about Retinitis Pigmentosa

    MedlinePlus

    ... genetic terms used on this page Learning About Retinitis Pigmentosa What is retinitis pigmentosa? What are the symptoms ... Pigmentosa Additional Resources for Retinitis Pigmentosa What is retinitis pigmentosa? Retinitis pigmentosa (RP) is the name given to ...

  1. mTOR regulates neuroprotective effect of immunized CD4+Foxp3+ T cells in optic nerve ischemia

    PubMed Central

    Chen, Guochun; Tang, Luosheng; Wei, Wei; Li, Zhuo; Li, Yunping; Duan, Xuanchu; Chen, Huihui

    2016-01-01

    The therapeutic potential of targeting CD4+Foxp3+ regulatory T cells (Tregs) remains controversial under the condition of neuroinflammation. This study aims to explore the neuroprotective role of Tregs in optic nerve ischemia (ONI) and evaluate the therapeutic strategy of Tregs transfer with a focus on targeting the mammalian target of rapamycin (mTOR) pathway. Intraocular pressure was transiently increased in adult C57BL/6 mice to induce ONI. Mucosal tolerance of myelin basic protein (MBP) markedly increased retinal ganglion cell (RGC) survival after ONI through enhanced Tregs suppression. mTOR inhibition significantly promoted the frequency of MBP-immunized Tregs in vitro with increased production of anti-inflammatory cytokines. Transient rapamycin treatment highly promoted the immunosuppressive capacity of Tregs and inhibited retinal inflammation in ONI animals. Intravenous infusion of MBP-immunized Tregs, instead of regular Tregs, beneficially modulated immune activities of host retinal CD11b+ cells and CD4+ effector T cells, leading to significant improvement of RGC survival. Importantly, rapamycin treatment further enhanced the neuroprotective effect of Tregs transfer. Taken together, these findings reveal a fine regulation of mTOR signaling on immunized Tregs after acute retinal injury. Adoptive transfer with targeting-mTOR strategy markedly improves neuronal recovery after ONI, supporting the therapeutic potentials of Tregs in acute and chronic neurological disorder. PMID:27886260

  2. [Ascaris lumbricoides in the nasogastric tube after operation on a patient with the diagnosis of acute mesenteric ischemia: case report].

    PubMed

    Çiçek, Ayşegül Çopur; Gündoğdu, Deniz; Direkel, Sahin; Öztürk, Çinar

    2013-01-01

    Ascaris lumbricoides is a comman intestinal helminths in humans. It is a parasite which commonly affects society with a low socioeconomic status, especially in tropical and rural areas. Ascaris lumbricoides infestation can lead to serious complications because of the mobility of the worms. The parasite can cause a variety of complications like intestinal obstruction, perforation, biliary obstruction, pancreatitis, peritonitis, liver abscess, cholangiohepatitis, volvulus, and gangrene, etc. A 59-year-old female patient hospitalized with the diagnosis of mesenteric ischemia was operated on for jejunal resection. On the 6th postoperative day, a worm was noticed emerging through the nasogastric tube. Ascaris lumbricoides was determined as a result of the examination microbiology laboratory. The patient was treated successfully with one dose of albendazole 200 mg 1x2. Our case describes a clinical situation of ascariasis observed after jejunal resection and emphasizes the importance of remaining aware of this rare complication of ascariasis.

  3. Enhancement of acute ethanol hepatotoxicity under conditions of low oxygen supply and ischemia/reperfusion. The role of oxygen radicals.

    PubMed

    Younes, M; Wagner, H; Strubelt, O

    1989-10-15

    Using isolated hemoglobin-free perfused rat livers we studied the effect of low oxygen supply on ethanol hepatotoxicity in two models. In the first model resembling low blood supply, perfusion rate was lowered from 60 to 10 ml/min after a 30 min-equilibration phase and kept low for 60 min. As a consequence, oxygen consumption fell from 1.76 +/- 0.15 mumol/min/g to 0.51 +/- 0.02 mumol/min/g. In the second model, total ischemia was accomplished by interruption of the perfusion for 30 min and was followed by reperfusion at a perfusion rate of 60 ml/min for a further 30 min. In this model, oxygen consumption returned immediately to normal values upon reperfusion. In both models, low oxygen supply had no toxic effects of its own on livers from fed rats. While ethanol (3 g/l) given under normoxic conditions led to a moderate hepatotoxicity, its application in both models of partial as well as total ischemia and reperfusion resulted in a marked liver damage as evidenced by a strong release of sorbitol dehydrogenase, glutamate-pyruvate-transaminase, lactate dehydrogenase and glutathione, as well as by an increase in hepatic calcium content. Inhibition of ethanol metabolism by 4-methylpyrazol prevented liver damage in both models indicating that metabolism of ethanol is a prerequisite for its toxicity to occur. Also, hepatotoxicity was inhibited partially by catalase and superoxide dismutase and nearly totally by deferrioxamine and allopurinol. Thus, reactive oxygen species which are produced during ethanol metabolism as well as under conditions of low oxygen supply are mediators of hepatic damage in both models employed.

  4. Synergistic action of hypoosmolarity and glutamine in inducing acute swelling of retinal glial (Müller) cells.

    PubMed

    Karl, Anett; Wurm, Antje; Pannicke, Thomas; Krügel, Katja; Obara-Michlewska, Marta; Wiedemann, Peter; Reichenbach, Andreas; Albrecht, Jan; Bringmann, Andreas

    2011-02-01

    High blood ammonia, elevated glutamine, and hyponatremia are pathogenic factors contributing to astrocytic swelling and brain edema in liver failure. We investigated the effects of hypoosmolarity, ammonia, and glutamine on the induction of glial cell swelling in freshly isolated slices of the rat retina. Glutamine, but not ammonia or hypoosmolarity per se, evoked a rapid (within one minute) swelling of retinal glial (Müller) cell bodies under hypoosmotic conditions. Under isoosmotic conditions, glutamine evoked a delayed swelling after 10 min of exposure. The effect of glutamine was concentration-dependent, with half-maximal and maximal effects at ∼ 0.1 and 0.5 mM. Glutamine in hypoosmotic solution induced a dissipation of the mitochondrial membrane potential. The effects on the mitochondrial membrane potential and the glial soma size were reduced by (i) agents which inhibit the transfer of glutamine into mitochondria and its hydrolysis there, (ii) inhibition of the mitochondrial permeability transition, (iii) inhibitors of oxidative-nitrosative stress, and (iv) inhibitors of phospholipase A(2) and cyclooxygenase. Glutamine-induced glial swelling was also prevented by ATP and adenosine, acting at adenosine A(1) receptors. The data suggest that hypoosmolarity accelerates the swelling-inducing effect of glutamine on retinal glial cells, and that swelling induction by glutamine is mediated by inducing oxidative-nitrosative stress, inflammatory lipid mediators, and mitochondrial dysfunction.

  5. Myocardial Ischemia

    MedlinePlus

    ... typically on the left side of the body (angina pectoris). Other signs and symptoms — which might be experienced ... ed. Philadelphia, Pa.: Saunders Elsevier; 2014. Podrid PJ. Angina pectoris: Chest pain caused by myocardial ischemia. www.uptodate. ...

  6. Retinal remodeling.

    PubMed

    Jones, B W; Kondo, M; Terasaki, H; Lin, Y; McCall, M; Marc, R E

    2012-07-01

    Retinal photoreceptor degeneration takes many forms. Mutations in rhodopsin genes or disorders of the retinal pigment epithelium, defects in the adenosine triphosphate binding cassette transporter, ABCR gene defects, receptor tyrosine kinase defects, ciliopathies and transport defects, defects in both transducin and arrestin, defects in rod cyclic guanosine 3',5'-monophosphate phosphodiesterase, peripherin defects, defects in metabotropic glutamate receptors, synthetic enzymatic defects, defects in genes associated with signaling, and many more can all result in retinal degenerative disease like retinitis pigmentosa (RP) or RP-like disorders. Age-related macular degeneration (AMD) and AMD-like disorders are possibly due to a constellation of potential gene targets and gene/gene interactions, while other defects result in diabetic retinopathy or glaucoma. However, all of these insults as well as traumatic insults to the retina result in retinal remodeling. Retinal remodeling is a universal finding subsequent to retinal degenerative disease that results in deafferentation of the neural retina from photoreceptor input as downstream neuronal elements respond to loss of input with negative plasticity. This negative plasticity is not passive in the face of photoreceptor degeneration, with a phased revision of retinal structure and function found at the molecular, synaptic, cell, and tissue levels involving all cell classes in the retina, including neurons and glia. Retinal remodeling has direct implications for the rescue of vision loss through bionic or biological approaches, as circuit revision in the retina corrupts any potential surrogate photoreceptor input to a remnant neural retina. However, there are a number of potential opportunities for intervention that are revealed through the study of retinal remodeling, including therapies that are designed to slow down photoreceptor loss, interventions that are designed to limit or arrest remodeling events, and

  7. Protective effects of salusin-α and salusin-β on renal ischemia/reperfusion damage and their levels in ischemic acute renal failure.

    PubMed

    Cakir, M; Duzova, H; Taslidere, A; Orhan, G; Ozyalin, F

    2017-01-01

    Salusin-α and salusin-β are expressed in many tissues including the central nervous system, vessels and kidneys; they have been shown to decrease endoplasmic reticulum stress during heart ischemia/reperfusion (I/R) and to decrease apoptosis. We investigated the relation of salusin-α and salusin-β levels to acute ischemic renal failure. We also investigated whether these peptides are protective against renal I/R damage. Fifty-three rats were divided into six groups: control, I/R, I/R + salusin-α1, I/R + salusin-α10, I/R + salusin-β1 and I/R + salusin-β10. After removing the right kidney, the left kidney was subjected to ischemia for 1 h and reperfusion for 23 h. The treatment groups were injected subcutaneously at the beginning of ischemia with 1 or 10 μg/kg salusin-α, and 1 or 10 μg/kg salusin-β. Histopathology was assessed at the end of the experiment. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-PX) activity and malondialdehyde (MDA) levels were measured in the kidney tissue. Serum levels of blood urea nitrogen (BUN), creatinine (Cre), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-1 beta (IL-1β) also were measured. Levels of salusin-α and salusin-β were measured in the serum and kidney tissues of the control and I/R groups. SOD, CAT and GSH-PX activities were decreased and the levels of MDA, TNF-α, IL-6, IL-1β, BUN and Cre were increased in the I/R group compared to controls. Severe glomerular and tubular damage was apparent in the I/R group compared to controls. The level of salusin-β was decreased in the serum and kidney tissue of the I/R group compared to controls, whereas the level of salusin-α was decreased in the serum and increased in the kidney tissue. Salusin-α and salusin-β administration increased SOD and GSH-PX enzyme activation and decreased the levels of MDA, TNF-α, IL-6 and IL-1β compared to the I/R group. BUN and Cre levels were decreased in the I/R + salusin-α1 group

  8. Intravenous Administration of Cilostazol Nanoparticles Ameliorates Acute Ischemic Stroke in a Cerebral Ischemia/Reperfusion-Induced Injury Model

    PubMed Central

    Nagai, Noriaki; Yoshioka, Chiaki; Ito, Yoshimasa; Funakami, Yoshinori; Nishikawa, Hiroyuki; Kawabata, Atsufumi

    2015-01-01

    It was reported that cilostazol (CLZ) suppressed disruption of the microvasculature in ischemic areas. In this study, we have designed novel injection formulations containing CLZ nanoparticles using 0.5% methylcellulose, 0.2% docusate sodium salt, and mill methods (CLZnano dispersion; particle size 81 ± 59 nm, mean ± S.D.), and investigated their toxicity and usefulness in a cerebral ischemia/reperfusion-induced injury model (MCAO/reperfusion mice). The pharmacokinetics of injections of CLZnano dispersions is similar to that of CLZ solutions prepared with 2-hydroxypropyl-β-cyclodextrin, and no changes in the rate of hemolysis of rabbit red blood cells, a model of cell injury, were observed with CLZnano dispersions. In addition, the intravenous injection of 0.6 mg/kg CLZnano dispersions does not affect the blood pressure and blood flow, and the 0.6 mg/kg CLZnano dispersions ameliorate neurological deficits and ischemic stroke in MCAO/reperfusion mice. It is possible that the CLZnano dispersions will provide effective therapy for ischemic stroke patients, and that injection preparations of lipophilic drugs containing drug nanoparticles expand their therapeutic usage. PMID:26690139

  9. An HPLC method for determination of inosine and hypoxanthine in human plasma from healthy volunteers and patients presenting with potential acute cardiac ischemia.

    PubMed

    Farthing, Don; Sica, Domenic; Gehr, Todd; Wilson, Bill; Fakhry, Itaf; Larus, Terri; Farthing, Christine; Karnes, H Thomas

    2007-07-01

    A simple and sensitive high-performance liquid chromatography (HPLC) method utilizing ultraviolet (UV) detection was developed for the determination of inosine and hypoxanthine in human plasma. For component separation, a monolithic C(18) column at a flow rate of 1.0 mL/min with an aqueous mobile phase of trifluoroacetic acid (0.1% TFA in deionized water pH 2.2, v/v) and methanol gradient was used. The method employed a one-step sample preparation utilizing centrifugal filtration with high component recoveries (approximately 98%) from plasma, which eliminated the need of an internal standard. The method demonstrated excellent linearity (0.25-5 microg/mL, R>0.9990) for both inosine and hypoxanthine with detection limits of 100 ng/mL. This simple and cost effective method was utilized to evaluate potential endogenous plasma biomarker(s), which may aid hospital emergency personnel in the early detection of acute cardiac ischemia in patients presenting with non-traumatic chest pain.

  10. Variation of plasma levels of endothelin, calcitonin gene-related peptide, nitric oxide, and malondialdehyde in acute myocardial ischemia reperfusion injury in a rabbit model.

    PubMed

    Zhao, Y B; Wang, Y Z; Yue, Y H; Zhao, W C; Feng, G X

    2015-05-25

    We examined the variation in plasma levels of endothelin (ET), calcitonin gene-related peptide (CGRP), nitric oxide (NO), and malondialdehyde (MDA), as well as superoxide dismutase (SOD) activity, in acute myocardial ischemia reperfusion injury in a rabbit model. Seventy rabbits were randomly assigned into 3 groups. Open-chest surgery (OCS) was performed for all rabbits. Group A (N = 20) received sham-surgery, group B (N = 25) was the reperfusion group, and group C (N = 25) was the infarction group. At 12 h after chest clo-sure, plasma ET levels in groups B and C were clearly increased, while CGRP levels were clearly decreased, particularly in group B. At 24 h after chest closure, ET levels were higher than before OCS, while there was no significant difference between groups B and C. ET in group B was decreased, while that in group C was increased at 12 h. No significant difference in CGRP was observed between 12 and 24 h after chest closure. NO levels in groups B and C at 12 h after chest closure were significantly decreased compared to those before OCS. NO levels in group B at 24, 48, and 72 h were significantly lower than those at 12 h, while those of group C were not significantly changed after 12 h. Dynamic monitoring and comparison of plasma levels of ET, CGRP, NO, and MDA as well as SOD activity revealed that appropriate intervention of these factors may reduce reperfusion injury.

  11. The effect of propofol postconditioning on the expression of K(+)-Cl(-)-co-transporter 2 in GABAergic inhibitory interneurons of acute ischemia/reperfusion injury rats.

    PubMed

    Wang, Hongbai; Liu, Shuying; Wang, Haiyun; Wang, Guolin; Zhu, Ai

    2015-02-09

    It has been shown in our previous study that propofol postconditioning enhanced the activity of phosphatidylinositol-3-kinase (PI3K) and prevented the internalization of GluR2 subunit of α-amino-3-hydroxyl-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, thus provided neuroprotection in cerebral ischemia/reperfusion (I/R) injury. Regarding inhibitory system in CNS, K(+)-Cl(-)-co-transporter 2 (KCC2), a Cl(-) extruder, plays a critical role in gamma-aminobutyric acid (GABA) inhibitory effect in mature central neurons. However, the effect of propofol postconditioning on the expression of KCC2 in GABAergic interneurons is unclear. Therefore, in this article we describe the role of KCC2 in GABAergic interneurons in the ipsilateral hippocampal CA1 region of adult rats and the effects of propofol postconditioning on this region. Herein we demonstrate that propofol postconditioning (20mg/kg/h, 2h) improved rats' neurobehavioral abilities, increased the number of survival neurons, and up-regulated neuronal KCC2 expression in glutamic acid decarboxylase 67 (GAD67) expressing GABAergic interneurons in hippocampal CA1 region at 24h after I/R. In contrast, when rats were injected with the KCC2 antagonist, [(dihydroindenyl)oxy] alkanoic acid (DIOA), the neuroprotective effects induced by propofol postconditioning were reversed. Our study indicated that propofol postconditioning increased the expression of KCC2 in inhibitory GABAergic interneurons, thus providing acute neuroprotection to rats who had undergone cerebral I/R injury.

  12. Severe Lower Limb Ischemia by Massive Arterial Thrombosis Revealing an Acute Myeloid Leukemia Needing for Leg Amputation: Clinical and Emotional Aspects Related to the Communication with the Patient and His Family

    PubMed Central

    Taormina, Calogero; Mosa, Clara; Di Marco, Floriana; Valentino, Fabrizio; Trizzino, Angela; Guadagna, Paola; Talarico, Francesco

    2016-01-01

    Large vessel thrombosis is a very rare clinical presentation of acute leukemia, generally associated with coagulopathy, usually characteristic of acute promyelocytic leukemia. A 13- year-old boy with a previously undiagnosed acute myeloid leukemia was referred to our hospital with acute ischemia of the right lower limb due to occlusion of the right external iliac artery, treated with emergency double surgical thromboembolectomy and chemotherapy. The thrombotic complication resulted in leg amputation. Now the boy is well in complete remission, with a good social integration and quality of life, 30 months after completing treatment. The report highlights the crucial role of early diagnosis and subsequent chemotherapy in avoiding amputation. We particularly focused critical and emotional aspects related to the communication about the leg amputation with the patient and his family. PMID:28058104

  13. A framework for classification and segmentation of branch retinal artery occlusion in SD-OCT

    NASA Astrophysics Data System (ADS)

    Guo, Jingyun; Shi, Fei; Zhu, Weifang; Chen, Haoyu; Chen, Xinjian

    2016-03-01

    Branch retinal artery occlusion (BRAO) is an ocular emergency which could lead to blindness. Quantitative analysis of BRAO region in the retina is very needed to assessment of the severity of retinal ischemia. In this paper, a fully automatic framework was proposed to classify and segment BRAO based on 3D spectral-domain optical coherence tomography (SD-OCT) images. To the best of our knowledge, this is the first automatic 3D BRAO segmentation framework. First, a support vector machine (SVM) based classifier is designed to differentiate BRAO into acute phase and chronic phase, and the two types are segmented separately. To segment BRAO in chronic phase, a threshold-based method is proposed based on the thickness of inner retina. While for segmenting BRAO in acute phase, a two-step segmentation is performed, which includes the bayesian posterior probability based initialization and the graph-search-graph-cut based segmentation. The proposed method was tested on SD-OCT images of 23 patients (12 of acute and 11 of chronic phase) using leave-one-out strategy. The overall classification accuracy of SVM classifier was 87.0%, and the TPVF and FPVF for acute phase were 91.1%, 5.5%; for chronic phase were 90.5%, 8.7%, respectively.

  14. Evaluation of Retinal Nerve Fiber Layer Thickness and Axonal Transport 1 and 2 Weeks After 8 Hours of Acute Intraocular Pressure Elevation in Rats

    PubMed Central

    Abbott, Carla J.; Choe, Tiffany E.; Lusardi, Theresa A.; Burgoyne, Claude F.; Wang, Lin; Fortune, Brad

    2014-01-01

    Purpose. To compare in vivo retinal nerve fiber layer thickness (RNFLT) and axonal transport at 1 and 2 weeks after an 8-hour acute IOP elevation in rats. Methods. Forty-seven adult male Brown Norway rats were used. Procedures were performed under anesthesia. The IOP was manometrically elevated to 50 mm Hg or held at 15 mm Hg (sham) for 8 hours unilaterally. The RNFLT was measured by spectral-domain optical coherence tomography. Anterograde and retrograde axonal transport was assessed from confocal scanning laser ophthalmoscopy imaging 24 hours after bilateral injections of 2 μL 1% cholera toxin B-subunit conjugated to AlexaFluor 488 into the vitreous or superior colliculi, respectively. Retinal ganglion cell (RGC) and microglial densities were determined using antibodies against Brn3a and Iba-1. Results. The RNFLT in experimental eyes increased from baseline by 11% at 1 day (P < 0.001), peaked at 19% at 1 week (P < 0.0001), remained 11% thicker at 2 weeks (P < 0.001), recovered at 3 weeks (P > 0.05), and showed no sign of thinning at 6 weeks (P > 0.05). There was no disruption of anterograde transport at 1 week (superior colliculi fluorescence intensity, 75.3 ± 7.9 arbitrary units [AU] for the experimental eyes and 77.1 ± 6.7 AU for the control eyes) (P = 0.438) or 2 weeks (P = 0.188). There was no obstruction of retrograde transport at 1 week (RCG density, 1651 ± 153 per mm2 for the experimental eyes and 1615 ± 135 per mm2 for the control eyes) (P = 0.63) or 2 weeks (P = 0.25). There was no loss of Brn3a-positive RGC density at 6 weeks (P = 0.74) and no increase in microglial density (P = 0.92). Conclusions. Acute IOP elevation to 50 mm Hg for 8 hours does not cause a persisting axonal transport deficit at 1 or 2 weeks or a detectable RNFLT or RGC loss by 6 weeks but does lead to transient RNFL thickening that resolves by 3 weeks. PMID:24398096

  15. A framework for retinal layer intensity analysis for retinal artery occlusion patient based on 3D OCT

    NASA Astrophysics Data System (ADS)

    Liao, Jianping; Chen, Haoyu; Zhou, Chunlei; Chen, Xinjian

    2014-03-01

    Occlusion of retinal artery leads to severe ischemia and dysfunction of retina. Quantitative analysis of the reflectivity in the retina is very needed to quantitative assessment of the severity of retinal ischemia. In this paper, we proposed a framework for retinal layer intensity analysis for retinal artery occlusion patient based on 3D OCT images. The proposed framework consists of five main steps. First, a pre-processing step is applied to the input OCT images. Second, the graph search method was applied to segment multiple surfaces in OCT images. Third, the RAO region was detected based on texture classification method. Fourth, the layer segmentation was refined using the detected RAO regions. Finally, the retinal layer intensity analysis was performed. The proposed method was tested on tested on 27 clinical Spectral domain OCT images. The preliminary results show the feasibility and efficacy of the proposed method.

  16. Retinal Prosthesis

    PubMed Central

    Weiland, James D.; Humayun, Mark S.

    2015-01-01

    Retinal prosthesis have been translated from the laboratory to the clinical over the past two decades. Currently, two devices have regulatory approval for the treatment of retinitis pigmentosa. These devices provide partial sight restoration and patients use this improved vision in their everyday lives. Improved mobility and object detection are some of the more notable findings from the clinical trials. However, significant vision restoration will require both better technology and improved understanding of the interaction between electrical stimulation and the retina. This paper reviews the recent clinical trials, highlights technology breakthroughs that will contribute to next generation of retinal prostheses. PMID:24710817

  17. [Aging and retinal vascular diseases].

    PubMed

    Takagi, Hitoshi

    2007-03-01

    recognized as a predominant factor to induce the ischemic retinal neovascularization. We found that retinal vascular cells have a characteristic pattern in VEGF receptor expression, which causes vascular pathology more frequently in the retina than in other organs. Neuropilin 1 (NRP 1), which enhances VEGF receptor function, is abundantly expressed in the retinal endothelial cells and is upregulated by VEGF itself and by hypoxia to regulate a positive feedback mechanism in retinal neovascularization. This receptor could be a unique target for retina-specific therapy. Lifestyle-related diseases increase along with aging and have further increased due to changes in Japanese lifestyle imitating that of Western countries. We found that the renin-angiotensin system which regulates hypertension and cardiovascular diseases, and adipocytokines which are abnormally secreted in obesity, act as proangiogenic factors. Regulation of such lifestyle-related disease factors is important for the treatment of retinal vascular diseases. Finally, we found that erythropoietin is an ischemia-induced angiogenic factor that acts independently and as potently as VEGF in proliferative diabetic retinopathy (PDR). Our study utilizing human vitreous samples demonstrates that the VEGF level is particularly high and strongly associated with angiogenic activity in PDR patients. The potential of VEGF inhibitors has recently been recognized in clinical applications. The manipulation of each angiogenic factor and adipocytokine that we report here could become potential therapy in the near future.

  18. Protective effect of melatonin and its precursor L-tryptophan on acute pancreatitis induced by caerulein overstimulation or ischemia/reperfusion.

    PubMed

    Jaworek, Jolanta; Leja-Szpak, Anna; Bonior, Joanna; Nawrot, Katarzyna; Tomaszewska, Romana; Stachura, Jerzy; Sendur, Ryszard; Pawlik, Wiesław; Brzozowski, Tomasz; Konturek, Stanisław J

    2003-01-01

    Melatonin, a pineal secretory product, synthesized from l-tryptophan, has received increased attention because of its antioxidative and immunomodulatory properties. It has been detected in the gut and shown to protect the gastric mucosa, and liver from acute damage, but the role of melatonin in the protection of the pancreas against acute inflammation is not clear. The aim of this study was to investigate the effects of melatonin and its precursor, l-tryptophan, on caerulein-induced pancreatitis (CIP) and on ischemia/reperfusion (I/R)-provoked pancreatitis in rats. CIP was induced by subcutaneous infusion of caerulein to the rats (25 microg/kg). I/R was induced by clamping of the inferior splenic artery for 30 min followed by 2 hr of reperfusion. Melatonin (10, 25 or 50 mg/hr) or l-tryptophan (50, 100 or 250 mg/kg) was given as a bolus intraperitoneal (i.p.) injection 30 min prior to the onset of pancreatitis. CIP and I/R were confirmed by histologic examination and manifested by typical pancreatic edema, by an increase of plasma levels of amylase (by 500% in CIP and by 40% in I/R) and the pro-inflammatory tumor necrosis factor alpha (TNFalpha) (by 500%). Lipid peroxidation products such as malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), were increased several fold in the pancreas CIP and I/R, whereas pancreatic blood flow (PBF) was significantly reduced in these animals. Pretreatment of rats subjected to CIP or to I/R with melatonin (25 or 50 mg/kg i.p.) or l-tryptophan (100 or 250 mg/kg i.p.) significantly reduced pancreatic edema, plasma levels of amylase and TNFalpha and diminished pancreatic MDA + 4-HNE contents, while enhancing PBF, pancreatic integrity and plasma levels of the anti-inflammatory interleukin 10 (IL-10). This was accompanied by a marked and dose-dependent rise of plasma melatonin immunoreactivity. Gene expression of N-acetyl transferase, an enzyme involved in melatonin biosynthesis, was detected in the pancreas of normal rats and was

  19. Retinal Detachment

    MedlinePlus

    ... immediately. Treatment How is retinal detachment treated? Small holes and tears are treated with laser surgery or ... laser surgery tiny burns are made around the hole to “weld” the retina back into place. Cryopexy ...

  20. Retinal Disorders

    MedlinePlus

    ... be serious enough to cause blindness. Examples are Macular degeneration - a disease that destroys your sharp, central vision Diabetic eye disease Retinal detachment - a medical emergency, when the retina is ... children. Macular pucker - scar tissue on the macula Macular hole - ...

  1. Bird eyes distinguish summer from winter: Retinal response to acute photoperiod change in the night-migratory redheaded bunting.

    PubMed

    Majumdar, Gaurav; Yadav, Garima; Rani, Sangeeta; Kumar, Vinod

    2015-10-01

    Eyes are the part of the circadian timekeeping system but not involved in the photoperiod regulated seasonal physiology in songbirds. Here, two experiments tested whether eyes detect and respond to seasonal change in the photoperiod environment, by examining gene and protein expressions in the retinas of redheaded buntings exposed to a single long day (LD, 16L:8D), with controls on short days (SD, 8L:16D). In the first experiment, mRNA expression of genes implicated in the light perception (opsins, rhodopsin, neuropsin, melanopsin, peropsin) and photoperiod induction (eya3, tsh-β, dio2, dio3) was measured at hours 15 and 19 (hour 0 = light on) on the first long day. There was a significant increase in the eya3, tsh-β and dio2 mRNA expression, albeit with a temporal difference, and decrease in the neuropsin mRNA expression in buntings on the first long day. There was no change in the dio3, rhodopsin, melanopsin and peropsin mRNA expressions on exposure to long days. The second experiment immunohistochemically examined the eya3, tsh-β and rhodopsin peptide expressions. eya3 was expressed in both light conditions, but with a significant higher levels in the retinal photoreceptor layer (PRL) under LD, as compared to SD. Similarly, tsh-β was expressed in the PRL of LD retinas only. Rhodopsin levels were not significantly different between SD and LD conditions, however. These results for the first time show photoperiod-dependent molecular switches in the bunting retina, similar to the well documented thyroid hormone response genes based molecular cascades in the avian hypothalamus.

  2. Plastic Change along the Intact Crossed Pathway in Acute Phase of Cerebral Ischemia Revealed by Optical Intrinsic Signal Imaging

    PubMed Central

    Guo, Xiaoli; He, Yongzhi; Lu, Hongyang; Li, Yao; Su, Xin; Jiang, Ying; Tong, Shanbao

    2016-01-01

    The intact crossed pathway via which the contralesional hemisphere responds to the ipsilesional somatosensory input has shown to be affected by unilateral stroke. The aim of this study was to investigate the plasticity of the intact crossed pathway in response to different intensities of stimulation in a rodent photothrombotic stroke model. Using optical intrinsic signal imaging, an overall increase of the contralesional cortical response was observed in the acute phase (≤48 hours) after stroke. In particular, the contralesional hyperactivation is more prominent under weak stimulations, while a strong stimulation would even elicit a depressed response. The results suggest a distinct stimulation-response pattern along the intact crossed pathway after stroke. We speculate that the contralesional hyperactivation under weak stimulations was due to the reorganization for compensatory response to the weak ipsilateral somatosensory input. PMID:27144032

  3. A single intracoronary injection of midkine reduces ischemia/reperfusion injury in Swine hearts: a novel therapeutic approach for acute coronary syndrome.

    PubMed

    Ishiguro, Hisaaki; Horiba, Mitsuru; Takenaka, Hiroharu; Sumida, Arihiro; Opthof, Tobias; Ishiguro, Yuko S; Kadomatsu, Kenji; Murohara, Toyoaki; Kodama, Itsuo

    2011-01-01

    Several growth factors are effective for salvaging myocardium and limiting infarct size in experimental studies with small animals. Their benefit in large animals and feasibility in clinical practice remains to be elucidated. We investigated the cardioprotective effect of midkine (MK) in swine subjected to ischemia/reperfusion (I/R). I/R was created by left anterior descending coronary artery occlusion for 45 min using a percutaneous over-the-wire balloon catheter. MK protein was injected as a bolus through the catheter at the initiation of reperfusion [MK-treated (MKT) group]. Saline was injected in controls (CONT). Infarct size/area at risk (24 h after I/R) in MKT was almost five times smaller than in CONT. Echocardiography in MKT revealed a significantly higher percent wall thickening of the interventricular septum, a higher left ventricular (LV) fractional shortening, and a lower E/e(') (ratio of transmitral to annular flow) compared with CONT. LV catheterization in MKT showed a lower LV end-diastolic pressure, and a higher dP/dt(max) compared with CONT. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling-positive myocytes and CD45-positive cell infiltration in the peri-infarct area were significantly less in MKT than in CONT. Here, we demonstrate that a single intracoronary injection of MK protein in swine hearts at the onset of reperfusion dramatically reduces infarct size and ameliorates systolic/diastolic LV function. This beneficial effect is associated with a reduction of apoptotic and inflammatory reactions. MK application during percutaneous coronary intervention may become a promising adjunctive therapy in acute coronary syndromes.

  4. Recovery of renal function after administration of adipose-tissue-derived stromal vascular fraction in rat model of acute kidney injury induced by ischemia/reperfusion injury.

    PubMed

    Lee, Chunwoo; Jang, Myoung Jin; Kim, Bo Hyun; Park, Jin Young; You, Dalsan; Jeong, In Gab; Hong, Jun Hyuk; Kim, Choung-Soo

    2017-03-10

    Acute kidney injury (AKI) induced by ischemia/reperfusion (I/R) injury is a major challenge in critical care medicine. The purpose of this study is to determine the therapeutic effects of the adipose-tissue-derived stromal vascular fraction (SVF) and the optimal route for SVF delivery in a rat model of AKI induced by I/R injury. Fifty male Sprague-Dawley rats were randomly divided into five groups (10 animals per group): sham, nephrectomy control, I/R injury control, renal arterial SVF infusion and subcapsular SVF injection. To induce AKI by I/R injury, the left renal artery was clamped with a nontraumatic vascular clamp for 40 min, and the right kidney was removed. Rats receiving renal arterial infusion of SVF had a significantly reduced increase in serum creatinine compared with the I/R injury control group at 4 days after I/R injury. The glomerular filtration rate of the renal arterial SVF infusion group was maintained at a level similar to that of the sham and nephrectomy control groups at 14 days after I/R injury. Masson's trichrome staining showed significantly less fibrosis in the renal arterial SVF infusion group compared with that in the I/R injury control group in the outer stripe (P < 0.001). TUNEL labeling showed significantly decreased apoptosis in both the renal arterial SVF infusion and subcapsular SVF injection groups compared with the I/R injury control group in the outer stripe (P < 0.001). Thus, renal function is effectively rescued from AKI induced by I/R injury through the renal arterial administration of SVF in a rat model.

  5. Retinal abnormalities in β-thalassemia major

    PubMed Central

    Bhoiwala, Devang L.; Dunaief, Joshua L.

    2015-01-01

    Patients with beta (β)-thalassemia (β-TM: thalassemia major, β-TI: thalassemia intermedia) have a variety of complications that may affect all organs, including the eye. Ocular abnormalities include retinal pigment epithelium degeneration, angioid streaks, venous tortuosity, night blindness, visual field defects, decreased visual acuity, color vision abnormalities, and acute visual loss. Patients with β-TM are transfusion dependent and require iron chelation therapy (ICT) in order to survive. Retinal degeneration may result from either retinal iron accumulation from transfusion-induced iron overload or retinal toxicity induced by ICT. Some who were never treated with ICT exhibited retinopathy, and others receiving ICT had chelator-induced retinopathy. We will focus on retinal abnormalities present in individuals with β-TM viewed in light of new findings on the mechanisms and manifestations of retinal iron toxicity. PMID:26325202

  6. Deferoxamine attenuates lipid peroxidation, blocks interleukin-6 production, ameliorates sepsis inflammatory response syndrome, and confers renoprotection after acute hepatic ischemia in pigs.

    PubMed

    Vlahakos, Demetrios; Arkadopoulos, Nikolaos; Kostopanagiotou, Georgia; Siasiakou, Sofia; Kaklamanis, Loukas; Degiannis, Dimitrios; Demonakou, Maria; Smyrniotis, Vassilios

    2012-04-01

    We have previously shown that deferoxamine (DFO) infusion protected myocardium against reperfusion injury in patients undergoing open heart surgery, and reduced brain edema, intracranial pressure, and lung injury in pigs with acute hepatic ischemia (AHI). The purpose of this research was to study if DFO could attenuate sepsis inflammatory response syndrome (SIRS) and confer renoprotection in the same model of AHI in anesthetized pigs. Fourteen animals were randomly allocated to two groups. In the Group DFO (n=7), 150mg/kg of DFO dissolved in normal saline was continuously infused in animals undergoing hepatic devascularization and portacaval anastomosis. The control group (Group C, n=7) underwent the same surgical procedure and received the same volume of normal saline infusion. Animals were euthanized after 24h. Hematological, biochemical parameters, malondialdehyde (MDA), and cytokines (interleukin [IL]-1β, IL-6, IL-8, IL-10, and tumor necrosis factor-α) were determined from sera obtained at baseline, at 12h, and after euthanasia. Hematoxylin-eosin and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling were used to evaluate necrosis and apoptosis, respectively, in kidney sections obtained after euthanasia. A rapid and substantial elevation (more than 100-fold) of serum IL-6 levels was observed in Group C reaching peak at the end of the experiment, associated with increased production of oxygen free radicals and lipid peroxidation (MDA 3.2±0.1nmol/mL at baseline and 5.5±0.9nmol/mL at the end of the experiment, P<0.05) and various manifestations of SIRS and multiple organ dysfunction (MOD), including elevation of high-sensitivity C-reactive protein, severe hypotension, leukocytosis, thrombocytopenia, hypoproteinemia, and increased serum levels of lactate dehydrogenase (fourfold), alkaline phosphatase (fourfold), alanine aminotransferase (14-fold), and ammonia (sevenfold). In sharp contrast, IL-6 production and lipid

  7. Ischemia-Modified Albumin as a Marker of Acute Coronary Syndrome: The Case for Revising the Concept of “N-Terminal Modification” to “Fatty Acid Occupation” of Albumin

    PubMed Central

    Oran, Bulent

    2017-01-01

    Ischemia-modified albumin (IMA) is assumed “N-terminal modified” albumin which is generated immediately following myocardial ischemia. The diagnosis of IMA is based on reduced cobalt binding affinity to albumin which is attributed mainly to incapability of cobalt to bind at albumin's modified N-terminus. Although the albumin cobalt binding test was accepted as a potentially powerful marker for discriminating acute coronary syndrome from nonischemic chest pain, its usefulness has been brought into question in recent years. Patients with acutely ischemic myocardium exhibit a rapid increase in serum levels of fatty acids (FAs). Almost all released FAs are strongly bound to albumin which create conformational changes in the protein with resultant reduced cobalt binding affinity. There is a clear metabolic and temporal relationship between IMA measured via albumin cobalt binding testing and serum levels of FAs. In line with what has been suggested recently in the literature, we conclude that a shift from the concept of “N-terminal modified” to “FA-occupied” albumin is required, as this better describes IMA in patients with acute coronary syndrome. We also offer “oxidation modified albumin, OMA,” which is conceptually different from the “FA-occupied” IMA, to describe modification of albumin in chronic disease associated with increased oxidative stress. PMID:28356609

  8. Oximetry: recent insights into retinal vasopathies and glaucoma.

    PubMed

    Boeckaert, J; Vandewalle, E; Stalmans, I

    2012-01-01

    This review will highlight a new technology and recent insights into measuring retinal oxygen saturation in several ophthalmic diseases. A growing body of evidence suggests that disturbances in retinal blood flow and oxygenation are related to several retinopathies and glaucoma, which can severely impair vision. The retinal oximeter may allow researchers and physicians to gain deeper insights into retinal physiology and clarify the impact of ischemia on retinal health and function. There are two commercially available systems to measure retinal oxygen saturation: the Oxymap retinal oximeter (Reykjavik, Iceland) and the Imedos Systems UG (Jena, Germany). In this review we will focus on the results obtained with Oxymap. Direct and non-invasive measurement of retinal oxygen saturation have potentially useful diagnostic and therapeutic indications in various eye diseases such as diabetic retinopathy, age-related macular degeneration, central retinal vein and artery occlusion, anterior ischemic optic neuropathy and retinopathy of prematurity. Despite several limitations, oxygen saturation assessment in the retinal vessels is a significant advancement in the understanding of ocular diseases. Nevertheless, further studies are needed to validate the use of oximetry in retinal vasopathies and glaucoma.

  9. Retinal Vessel Analysis (RVA) in the Context of Subarachnoid Hemorrhage - A Proof of Concept Study

    PubMed Central

    Weiss, Miriam; Clusmann, Hans; Fuest, Matthias; Mueller, Marguerite; Brockmann, Marc Alexander; Vilser, Walthard; Schmidt-Trucksäss, Arno; Hoellig, Anke; Seiz, Marcel; Thomé, Claudius; Kotliar, Konstantin; Schubert, Gerrit Alexander

    2016-01-01

    Background Timely detection of impending delayed cerebral ischemia after subarachnoid hemorrhage (SAH) is essential to improve outcome, but poses a diagnostic challenge. Retinal vessels as an embryological part of the intracranial vasculature are easily accessible for analysis and may hold the key to a new and non-invasive monitoring technique. This investigation aims to determine the feasibility of standardized retinal vessel analysis (RVA) in the context of SAH. Methods In a prospective pilot study, we performed RVA in six patients awake and cooperative with SAH in the acute phase (day 2–14) and eight patients at the time of follow-up (mean 4.6±1.7months after SAH), and included 33 age-matched healthy controls. Data was acquired using a manoeuvrable Dynamic Vessel Analyzer (Imedos Systems UG, Jena) for examination of retinal vessel dimension and neurovascular coupling. Results Image quality was satisfactory in the majority of cases (93.3%). In the acute phase after SAH, retinal arteries were significantly dilated when compared to the control group (124.2±4.3MU vs 110.9±11.4MU, p<0.01), a difference that persisted to a lesser extent in the later stage of the disease (122.7±17.2MU, p<0.05). Testing for neurovascular coupling showed a trend towards impaired primary vasodilation and secondary vasoconstriction (p = 0.08, p = 0.09 resp.) initially and partial recovery at the time of follow-up, indicating a relative improvement in a time-dependent fashion. Conclusion RVA is technically feasible in patients with SAH and can detect fluctuations in vessel diameter and autoregulation even in less severely affected patients. Preliminary data suggests potential for RVA as a new and non-invasive tool for advanced SAH monitoring, but clinical relevance and prognostic value will have to be determined in a larger cohort. PMID:27388619

  10. Retine revisited.

    PubMed

    Douglas, D E

    2002-10-01

    Retine, so named by Albert Szent-Györgyi, an inhibitor of the growth of transplanted malignant tumours in animals, is present in all mammalian tissues and in urine. Its inhibitory activity was extensively investigated by Szent-Györgyi, but its exact chemical identity was not determined. Details of the reported physical and chemical properties of retine and its ubiquitous occurrence identify it as being identical to a complex mixture of lipid 2,4-diketones of similar ubiquitous occurrence. This lipid mixture has been extensively studied, and individual members have been synthesized.

  11. Retinal Vascular Changes are a Marker for Cerebral Vascular Diseases.

    PubMed

    Moss, Heather E

    2015-07-01

    The retinal circulation is a potential marker of cerebral vascular disease because it shares origin and drainage with the intracranial circulation and because it can be directly visualized using ophthalmoscopy. Cross-sectional and cohort studies have demonstrated associations between chronic retinal and cerebral vascular disease, acute retinal and cerebral vascular disease, and chronic retinal vascular disease and acute cerebral vascular disease. In particular, certain qualitative features of retinopathy, retinal artery occlusion, and increased retinal vein caliber are associated with concurrent and future cerebrovascular events. These associations persist after accounting for confounding variables known to be disease-causing in both circulations, which supports the potential use of retinal vasculature findings to stratify individuals with regards to cerebral vascular disease risk.

  12. Microsystems Technology for Retinal Implants

    NASA Astrophysics Data System (ADS)

    Weiland, James

    2005-03-01

    The retinal prosthesis is targeted to treat age-related macular degeneration, retinitis pigmentosa, and other outer retinal degenerations. Simulations of artificial vision have predicted that 600-1000 individual pixels will be needed if a retinal prosthesis is to restore function such as reading large print and face recognition. An implantable device with this many electrode contacts will require microsystems technology as part of its design. An implantable retinal prosthesis will consist of several subsystems including an electrode array and hermetic packaging. Microsystems and microtechnology approaches are being investigated as possible solutions for these design problems. Flexible polydimethylsiloxane (PDMS) substrate electrode arrays and silicon micromachined electrode arrays are under development. Inactive PDMS electrodes have been implanted in 3 dogs to assess mechanical biocompatibility. 3 dogs were followed for 6 months. The implanted was securely fastened to the retina with a single retinal tack. No post-operative complications were evident. The array remained within 100 microns of the retinal surface. Histological evaluation showed a well preserved retina underneath the electrode array. A silicon device with electrodes suspended on micromachined springs has been implanted in 4 dogs (2 acute implants, 2 chronic implants). The device, though large, could be inserted into the eye and positioned on the retina. Histological analysis of the retina from the spring electrode implants showed that spring mounted posts penetrated the retina, thus the device will be redesigned to reduce the strength of the springs. These initial implants will provide information for the designers to make the next generation silicon device. We conclude that microsystems technology has the potential to make possible a retinal prosthesis with 1000 individual contacts in close proximity to the retina.

  13. Induced Pluripotent Stem Cell-Derived Conditioned Medium Attenuates Acute Kidney Injury by Downregulating the Oxidative Stress-Related Pathway in Ischemia-Reperfusion Rats.

    PubMed

    Tarng, Der-Cherng; Tseng, Wei-Cheng; Lee, Pei-Ying; Chiou, Shih-Hwa; Hsieh, Shie-Liang

    2016-01-01

    Teratoma-like formation addresses a critical safety concern for the potential utility of induced pluripotent stem cells (iPSCs). Therefore, therapy utilizing iPSC-derived conditioned medium (iPSC-CM) for acute kidney injury (AKI) has attracted substantial interest. A recent study showed that iPSC-CM effectively alleviated ventilator-induced lung injury in rats. It prompts us to assess the therapeutic effects of iPSC-CM on ischemic AKI. First, we assessed the changes in renal function and tubular cell apoptosis by intraperitoneal administration of iPSC-CM to ischemia-reperfusion (I/R) rats. Second, we explored the oxidative stress-related pathway in the apoptosis of renal tubular cells subjected to hypoxia-reoxygenation (H/R). Administration of iPSC-CM significantly improved renal function and protected tubular cells against apoptosis in rats with I/R-AKI, and the optimal effect was observed at the 50-fold concentrated iPSC-CM. iPSC-CM also mitigated the H/R-induced apoptosis of NRK-52E cells in vitro. Reactive oxygen species (ROS) production was augmented in kidneys following I/R and in NRK-52E cells subjected to H/R. Meanwhile, expressions of phosphorylated p38 MAPK, TNF-α, and cleaved caspase 3 and NF-κB activity were consistently increased in vivo and in vitro. Following administration of iPSC-CM, ROS production was abolished, and inflammatory cytokine expression was significantly suppressed. Annexin V-propidium iodide flow cytometry and in situ TUNEL assay further showed that iPSC-CM markedly attenuated H/R- or I/R-induced tubular cell apoptosis. Intriguingly, treatment with iPSC-CM significantly improved the survival of rats with I/R-induced AKI. iPSC-CM represents a favorable source of stem cell-based therapy and may serve as a potential therapeutic strategy for kidney repair in ischemic AKI.

  14. Retinitis pigmentosa

    PubMed Central

    Hamel, Christian

    2006-01-01

    Retinitis pigmentosa (RP) is an inherited retinal dystrophy caused by the loss of photoreceptors and characterized by retinal pigment deposits visible on fundus examination. Prevalence of non syndromic RP is approximately 1/4,000. The most common form of RP is a rod-cone dystrophy, in which the first symptom is night blindness, followed by the progressive loss in the peripheral visual field in daylight, and eventually leading to blindness after several decades. Some extreme cases may have a rapid evolution over two decades or a slow progression that never leads to blindness. In some cases, the clinical presentation is a cone-rod dystrophy, in which the decrease in visual acuity predominates over the visual field loss. RP is usually non syndromic but there are also many syndromic forms, the most frequent being Usher syndrome. To date, 45 causative genes/loci have been identified in non syndromic RP (for the autosomal dominant, autosomal recessive, X-linked, and digenic forms). Clinical diagnosis is based on the presence of night blindness and peripheral visual field defects, lesions in the fundus, hypovolted electroretinogram traces, and progressive worsening of these signs. Molecular diagnosis can be made for some genes, but is not usually performed due to the tremendous genetic heterogeneity of the disease. Genetic counseling is always advised. Currently, there is no therapy that stops the evolution of the disease or restores the vision, so the visual prognosis is poor. The therapeutic approach is restricted to slowing down the degenerative process by sunlight protection and vitaminotherapy, treating the complications (cataract and macular edema), and helping patients to cope with the social and psychological impact of blindness. However, new therapeutic strategies are emerging from intensive research (gene therapy, neuroprotection, retinal prosthesis). PMID:17032466

  15. Effectiveness of Panax ginseng on Acute Myocardial Ischemia Reperfusion Injury Was Abolished by Flutamide via Endogenous Testosterone-Mediated Akt Pathway.

    PubMed

    Pei, Luo; Shaozhen, Hou; Gengting, Dong; Tingbo, Chen; Liang, Liu; Hua, Zhou

    2013-01-01

    Mechanisms for Panax ginseng's cardioprotective effect against ischemia reperfusion injury involve the estrogen-mediated pathway, but little is known about the role of androgen. A standardized Panax ginseng extract (RSE) was orally given with or without flutamide in a left anterior descending coronary artery ligation rat model. Infarct size, CK and LDH activities were measured. Time-related changes of NO, PI3K/Akt/eNOS signaling, and testosterone concentration were also investigated. RSE (80 mg/kg) significantly inhibited myocardial infarction and CK and LDH activities, while coadministration of flutamide abolished this effect of RSE. NO was increased by RSE and reached a peak after 15 min of ischemia; however, flutamide cotreatment suppressed this elevation. Western blot analysis showed that RSE significantly reversed the decreases of expression and activation of PI3K, Akt, and eNOS evoked by ischemia, whereas flutamide attenuated the effects of these protective mechanisms induced by RSE. RSE completely reversed the dropping of endogenous testosterone level induced by I/R injury. Flutamide plus RSE treatment not only abolished RSE's effect but also produced a dramatic change on endogenous testosterone level after pretreatment and ischemia. Our results for the first time indicate that blocking androgen receptor abolishes the ability of Panax ginseng to protect the heart from myocardial I/R injury.

  16. Severity of middle cerebral artery occlusion determines retinal deficits in rats

    PubMed Central

    Allen, Rachael S.; Sayeed, Iqbal; Cale, Heather A.; Morrison, Katherine C.; Boatright, Jeffrey H.; Pardue, Machelle T.; Stein, Donald G.

    2014-01-01

    Middle cerebral artery occlusion (MCAO) using the intraluminal suture technique is a common model used to study cerebral ischemia in rodents. Due to the proximity of the ophthalmic artery to the middle cerebral artery, MCAO blocks both arteries, causing both cerebral and retinal ischemia. While previous studies have shown retinal dysfunction at 48 hours post-MCAO, we investigated whether these retinal function deficits persist until 9 days and whether they correlate with central neurological deficits. Rats received 90 minutes of transient MCAO followed by electroretinography at 2 and 9 days to assess retinal function. Retinal damage was assessed with cresyl violet staining, immunohistochemistry for glial fibrillary acidic protein (GFAP) and glutamine synthetase, and TUNEL staining. Rats showed behavioral deficits as assessed with neuroscore that correlated with cerebral infarct size and retinal function at 2 days. Two days after surgery, rats with moderate MCAO (neuroscore < 5) exhibited delays in electroretinogram implicit time, while rats with severe MCAO (neuroscore ≥ 5) exhibited reductions in amplitude. Glutamine synthetase was upregulated in Müller cells 3 days after MCAO in both severe and moderate animals, however, retinal ganglion cell death was only observed in MCAO retinas from severe animals. By 9 days after MCAO, both glutamine synthetase labeling and electroretinograms had returned to normal levels in moderate animals. Early retinal function deficits correlated with behavioral deficits. However, retinal function decreases were transient and selective retinal cell loss was observed only with severe ischemia, suggesting that the retina is less susceptible to MCAO than the brain. Temporary retinal deficits caused by MCAO are likely due to ischemia-induced increases in extracellular glutamate that impair signal conduction, but resolve by 9 days after MCAO. PMID:24518488

  17. Different roles played by periostin splice variants in retinal neovascularization.

    PubMed

    Nakama, Takahito; Yoshida, Shigeo; Ishikawa, Keijiro; Kobayashi, Yoshiyuki; Abe, Takaya; Kiyonari, Hiroshi; Shioi, Go; Katsuragi, Naruto; Ishibashi, Tatsuro; Morishita, Ryuichi; Taniyama, Yoshiaki

    2016-12-01

    Retinal neovascularization (NV) due to retinal ischemia is one of the major causes of vision reduction in patients with different types of retinal diseases although anti-vascular endothelial growth factor (anti-VEGF) therapy can partially reduce the size of the retinal NV. We recently reported that periostin plays an important role in the development of NV and the formation of preretinal fibrovascular membranes, but the role of the splice variants of periostin on retinal NV has not been determined. We examined the expressions of periostin splice variants in the ischemic retinas of a mouse model of oxygen-induced retinal NV. We also studied the function of periostin splice variants on retinal NV using periostin knock out mice, and the effects of anti-periostin antibodies on retinal NV. Our results showed that the expressions of the periostin splice variants were increased in ischemic retinas. The degree of increase of periostin lacking exon 17 was the highest among the periostin splice variants examined. Both genetic ablation of periostin exons 17 and 21 and antibodies for periostin exons 17 and 21 affected preretinal pathological NV. Inhibition of exon 17 of periostin had the greatest effect in reducing preretinal pathological NV. These findings suggest a causal link between periostin splice variants and retinal NV, and an intravitreal injection of antibody for exon 17 and exon 21 of periostin should be considered to inhibit preretinal pathological NV.

  18. Retinal vascular caliber and risk of dementia

    PubMed Central

    de Jong, F.J.; Schrijvers, E.M.C.; Ikram, M.K.; Koudstaal, P.J.; de Jong, P.T.V.M.; Hofman, A.; Vingerling, J.R.

    2011-01-01

    Background: Retinal vessels provide a unique opportunity to study both systemic and cerebrovascular disease. Smaller retinal arteriolar calibers are strongly related to hypertension, whereas larger retinal venular calibers are more related to inflammation, cerebral hypoperfusion, and cerebrovascular disease. Whether retinal vessel calibers are related to dementia remains unclear. Methods: We investigated whether retinal arteriolar and venular calibers are associated with risk of dementia, and its subtypes Alzheimer disease (AD) and vascular dementia, in the prospective population-based Rotterdam Study. Digitized retinal images were available in 5,553 participants aged 55 years or over and dementia-free at baseline (1990–1993). Participants were re-examined in 1993–1994, 1997–1999, and 2002–2004 and were continuously monitored for development of dementia. Results: During a mean follow-up of 11.6 years, 655 participants developed dementia. AD was diagnosed in 519 and vascular dementia in 73 participants. Larger venular calibers were associated with an increased risk of dementia, in particular vascular dementia (age- and sex-adjusted hazard ratio per SD increase: 1.31; 95% confidence interval 1.06–1.64), but not AD. The association remained significant after adjustment for stroke and cardiovascular risk factors. Smaller arteriolar calibers were also associated with an increased risk of vascular dementia, yet only when adjusted for venular calibers. Conclusions: Retinal venular widening is associated with an increased risk of vascular dementia. Our findings are in line with previous observations in stroke and cerebral small-vessel disease and suggest that the association between larger retinal venular calibers and dementia may reflect cerebral hypoperfusion and subsequent ischemia. PMID:21288987

  19. Interventions for asymptomatic retinal breaks and lattice degeneration for preventing retinal detachment

    PubMed Central

    Wilkinson, Charles P

    2016-01-01

    Background Asymptomatic retinal breaks and lattice degeneration are visible lesions that are risk factors for later retinal detachment. Retinal detachments occur when fluid in the vitreous cavity passes through tears or holes in the retina and separates the retina from the underlying retinal pigment epithelium. Creation of an adhesion surrounding retinal breaks and lattice degeneration, with laser photocoagulation or cryotherapy, has been recommended as an effective means of preventing retinal detachment. This therapy is of value in the management of retinal tears associated with the symptoms of flashes and floaters and persistent vitreous traction upon the retina in the region of the retinal break, because such symptomatic retinal tears are associated with a high rate of progression to retinal detachment. Retinal tears and holes unassociated with acute symptoms and lattice degeneration are significantly less likely to be the sites of retinal breaks that are responsible for later retinal detachment. Nevertheless, treatment of these problems is frequently recommended, in spite of the fact that the effectiveness of this therapy is unproven. Objectives The purpose of this review was to evaluate the effectiveness of interventions for asymptomatic retinal breaks and lattice degeneration. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 1), MEDLINE (January 1950 to January 2012), EMBASE (January 1980 to January 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 28 January 2012. Textbooks regarding retinal detachment and the reference lists of relevant reports were reviewed for additional

  20. Intravitreal injection of forskolin, homotaurine, and L-carnosine affords neuroprotection to retinal ganglion cells following retinal ischemic injury

    PubMed Central

    Adornetto, Annagrazia; Cavaliere, Federica; Varano, Giuseppe Pasquale; Rusciano, Dario; Morrone, Luigi Antonio; Corasaniti, Maria Tiziana; Bagetta, Giacinto; Nucci, Carlo

    2015-01-01

    Purpose Retinal ganglion cell (RGC) death is the final event leading to visual impairment in glaucoma; therefore, identification of neuroprotective strategies able to slow down or prevent the process is one of the main challenges for glaucoma research. The purpose of this study was to evaluate the neuroprotective potential of RGC death induced by the in vivo transient increase in intraocular pressure (IOP) of a combined treatment with forskolin, homotaurine, and L-carnosine. Forskolin (7beta-acetoxy-8, 13-epoxy-1a, 6β, 9a-trihydroxy-labd-14-en-11-one) is an activator of adenylate cyclase that decreases IOP by reducing aqueous humor production and functions as a neuroprotector due to its neurotrophin-stimulating activity. Homotaurine is a natural aminosulfonate compound endowed with neuromodulatory effects, while the dipeptide L-carnosine is known for its antioxidant properties. Methods Retinal ischemia was induced in the right eye of adult male Wistar rats by acutely increasing the IOP. Forskolin, homotaurine, and L-carnosine were intravitreally injected and RGC survival evaluated following retrograde labeling with FluoroGold. Total and phosphorylated Akt and glycogen synthase kinase-3β (GSK-3β) protein levels, as well as calpain activity, were analyzed with western blot. Protein kinase A (PKA) was inhibited by intravitreal injection of H89. Results A synergic neuroprotective effect on RGC survival was observed following the combined treatment with forskolin, homotaurine, and L-carnosine compared to forskolin alone. The observed neuroprotection was associated with reduced calpain activity, upregulation of phosphoinositide 3-kinase (PI3K)/Akt pathway, and inhibition of GSK-3β but was independent from PKA activation and distinct from the hypotensive effects of forskolin. Conclusions A multidrug/multitarget approach, by interfering with several pathways involved in RGC degeneration, may be promising to achieve glaucoma neuroprotection. PMID:26167113

  1. 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

  2. Immune reconstitution complicated by CMV retinitis in a pediatric patient who underwent haploidentical CD34+-selected hematopoietic stem cell transplant for acute lymphoblastic leukemia.

    PubMed

    Cesaro, Simone; Boaro, Maria Paola; Pillon, Marta; Calore, Elisabetta; Cermakova, Ivete; Perruccio, Katia; Mengoli, Carlo; Messina, Chiara

    2008-09-01

    We describe two episodes of CMV retinitis in a pediatric patient who underwent a CD34+ selected graft from his haploidentical father. Both recipient and donor were cytomegalovirus (CMV) seropositive. Both episodes occurred late post-grafting during a phase of complete immunological recovery with sufficient numbers of circulating CMV-specific clones. Antiviral treatment with foscarnet and ganciclovir was successful but prolonged treatment was required to prevent relapses. We hypothesize that this complication was more related to an immune reconstitution process than to an immune-deficient state post-grafting. We conclude that CMV retinitis is a late complication of HSCT that can occur despite satisfactory immune reconstitution. Usually, it is responsive to antiviral therapy. Dilated fundoscopic examination is essential both for examining patients with reduced visual acuity and for screening asymptomatic patients.

  3. Missed retinal breaks in rhegmatogenous retinal detachment

    PubMed Central

    Takkar, Brijesh; Azad, Shorya; Shashni, Adarsh; Pujari, Amar; Bhatia, Indrish; Azad, Rajvardhan

    2016-01-01

    AIM To evaluate the causes and associations of missed retinal breaks (MRBs) and posterior vitreous detachment (PVD) in patients with rhegmatogenous retinal detachment (RRD). METHODS Case sheets of patients undergoing vitreo retinal surgery for RRD at a tertiary eye care centre were evaluated retrospectively. Out of the 378 records screened, 253 were included for analysis of MRBs and 191 patients were included for analysis of PVD, depending on the inclusion criteria. Features of RRD and retinal breaks noted on examination were compared to the status of MRBs and PVD detected during surgery for possible associations. RESULTS Overall, 27% patients had MRBs. Retinal holes were commonly missed in patients with lattice degeneration while missed retinal tears were associated with presence of complete PVD. Patients operated for cataract surgery were significantly associated with MRBs (P=0.033) with the odds of missing a retinal break being 1.91 as compared to patients with natural lens. Advanced proliferative vitreo retinopathy (PVR) and retinal bullae were the most common reasons for missing a retinal break during examination. PVD was present in 52% of the cases and was wrongly assessed in 16%. Retinal bullae, pseudophakia/aphakia, myopia, and horse shoe retinal tears were strongly associated with presence of PVD. Traumatic RRDs were rarely associated with PVD. CONCLUSION Pseudophakic patients, and patients with retinal bullae or advanced PVR should be carefully screened for MRBs. Though Weiss ring is a good indicator of PVD, it may still be over diagnosed in some cases. PVD is associated with retinal bullae and pseudophakia, and inversely with traumatic RRD. PMID:27990367

  4. Distinct effects of acute pretreatment with lipophilic and hydrophilic statins on myocardial stunning, arrhythmias and lethal injury in the rat heart subjected to ischemia/reperfusion.

    PubMed

    Čarnická, S; Adameová, A; Nemčeková, M; Matejíková, J; Pancza, D; Ravingerová, T

    2011-01-01

    Although both lipophilic and more hydrophilic statins share the same pathway of the inhibition of HMG-CoA reductase, their pleiotropic cardioprotective effects associated with the ability to cross cellular membranes, including membranes of heart cells, may differ. To test this hypothesis, isolated rat hearts were Langendorff-perfused either with simvastatin (S, 10 micromol/l) or pravastatin (P, 30 micromol/l), 15 min prior to ischemia. Control untreated hearts (C) were perfused with perfusion medium only. Postischemic contractile dysfunction, reperfusion-induced ventricular arrhythmias and infarct size were investigated after exposure of the hearts to 30-min global ischemia and 2-h reperfusion. Both lipophilic S and hydrophilic P reduced the severity of ventricular arrhythmias (arrhythmia score) from 4.3 +/- 0.2 in C to 3.0 +/- 0 and 2.7 +/- 0.2 in S and P, respectively, (both P < 0.05), decreased the duration of ventricular tachycardia and suppressed ventricular fibrillation. Likewise, the extent of lethal injury (infarct size) determined by tetrazolium staining and expressed in percentage of risk area, was significantly lower in both treated groups, moreover, the effect of P was more pronounced (27 +/- 2 % and 10 +/- 2 % in S and P groups, respectively, vs. 42 +/- 1 % in C; P < 0.05). In contrast, only S, but not P, was able to improve postischemic recovery of left ventricular developed pressure (LVDP; 48 +/- 12 % of preischemic values vs. 25 +/- 4 % in C and 21 +/ -7 % in P groups; P < 0.05). Our results suggest that differences in water solubility of statins indicating a different ability to cross cardiac membranes may underlie their distinct cardioprotective effects on myocardial stunning and lethal injury induced by ischemia/reperfusion.

  5. Acute coronary care 1986

    SciTech Connect

    Califf, R.M.; Wagner, G.S.

    1985-01-01

    This book contains 22 chapters. Some of the titles are: The measurement of acute myocardial infarct size by CT; Magnetic resonance imaging for evaluation of myocardial ischemia and infarction; Poistron imaging in the evaluation of ischemia and myocardial infarction; and New inotropic agents.

  6. Endogenous and Synthetic Cannabinoids as Therapeutics in Retinal Disease

    PubMed Central

    Kokona, Despina; Georgiou, Panagiota-Christina; Kounenidakis, Mihalis; Kiagiadaki, Foteini; Thermos, Kyriaki

    2016-01-01

    The functional significance of cannabinoids in ocular physiology and disease has been reported some decades ago. In the early 1970s, subjects who smoked Cannabis sativa developed lower intraocular pressure (IOP). This led to the isolation of phytocannabinoids from this plant and the study of their therapeutic effects in glaucoma. The main treatment of this disease to date involves the administration of drugs mediating either the decrease of aqueous humour synthesis or the increase of its outflow and thus reduces IOP. However, the reduction of IOP is not sufficient to prevent visual field loss. Retinal diseases, such as glaucoma and diabetic retinopathy, have been defined as neurodegenerative diseases and characterized by ischemia-induced excitotoxicity and loss of retinal neurons. Therefore, new therapeutic strategies must be applied in order to target retinal cell death, reduction of visual acuity, and blindness. The aim of the present review is to address the neuroprotective and therapeutic potential of cannabinoids in retinal disease. PMID:26881135

  7. Retinal pathways influence temporal niche

    PubMed Central

    Doyle, Susan E.; Yoshikawa, Tomoko; Hillson, Holly; Menaker, Michael

    2008-01-01

    In mammals, light input from the retina entrains central circadian oscillators located in the suprachiasmatic nuclei (SCN). The phase of circadian activity rhythms with respect to the external light:dark cycle is reversed in diurnal and nocturnal species, although the phase of SCN rhythms relative to the light cycle remains unchanged. Neural mechanisms downstream from the SCN are therefore believed to determine diurnality or nocturnality. Here, we report a switch from nocturnal to diurnal entrainment of circadian activity rhythms in double-knockout mice lacking the inner-retinal photopigment melanopsin (OPN4) and RPE65, a key protein used in retinal chromophore recycling. These mice retained only a small amount of rod function. The change in entrainment phase of Rpe65−/−;Opn4−/− mice was accompanied by a reversal of the rhythm of clock gene expression in the SCN and a reversal in acute masking effects of both light and darkness on activity, suggesting that the nocturnal to diurnal switch is due to a change in the neural response to light upstream from the SCN. A switch from nocturnal to diurnal activity rhythms was also found in wild-type mice transferred from standard intensity light:dark cycles to light:dark cycles in which the intensity of the light phase was reduced to scotopic levels. These results reveal a novel mechanism by which changes in retinal input can mediate acute temporal-niche switching. PMID:18695249

  8. Basic Fibroblast Growth Factor Contributes to a Shift in the Angioregulatory Activity of Retinal Glial (Müller) Cells

    PubMed Central

    Yafai, Yousef; Iandiev, Ianors; Lange, Johannes; Yang, Xiu Mei; Wiedemann, Peter; Bringmann, Andreas; Eichler, Wolfram

    2013-01-01

    Basic fibroblast growth factor (bFGF) is a pleiotropic cytokine with pro-angiogenic and neurotrophic effects. The angioregulatory role of this molecule may become especially significant in retinal neovascularization, which is a hallmark of a number of ischemic eye diseases. This study was undertaken to reveal expression characteristics of bFGF, produced by retinal glial (Müller) cells, and to determine conditions under which glial bFGF may stimulate the proliferation of retinal microvascular endothelial cells. Immunofluorescence labeling detected bFGF in Müller cells of the rat retina and in acutely isolated Müller cells with bFGF levels, which increased after ischemia-reperfusion in postischemic retinas. In patients with proliferative diabetic retinopathy or myopia, the immunoreactivity of bFGF co-localized to glial fibrillary acidic protein (GFAP)-positive cells in surgically excised retinal tissues. RT-PCR and ELISA analyses indicated that cultured Müller cells produce bFGF, which is elevated under hypoxia or oxidative stress, as well as under stimulation with various growth factors and cytokines, including pro-inflammatory factors. When retinal endothelial cells were cultured in the presence of media from hypoxia (0.2%)-conditioned Müller cells, a distinct picture of endothelial cell proliferation emerged. Media from 24-h cultured Müller cells inhibited proliferation, whereas 72-h conditioned media elicited a stimulatory effect. BFGF-neutralizing antibodies suppressed the enhanced endothelial cell proliferation to a similar extent as anti-VEGF antibodies. Furthermore, phosphorylation of extracellular signal-regulated kinases (ERK−1/−2) in retinal endothelial cells was increased when the cells were cultured in 72-h conditioned media, while neutralizing bFGF attenuated the activation of this signaling pathway. These data provide evidence that retinal (glial) Müller cells are major sources of bFGF in the ischemic retina. Müller cells under

  9. Unilateral Ischemic Maculopathy Associated with Cytomegalovirus Retinitis in Patients with AIDS: Optical Coherence Tomography Findings

    PubMed Central

    Arevalo, J. Fernando; Garcia, Reinaldo A.; Arevalo, Fernando A.; Fernandez, Carlos F.

    2015-01-01

    To describe the clinical and optical coherence tomography (OCT) characteristics of ischemic maculopathy in two patients with acquired immunodeficiency syndrome (AIDS). Two patients with AIDS and cytomegalovirus (CMV) retinitis developed ischemic maculopathy. Both patients presented with central visual loss and active granular CMV retinitis. The presence of opacification of the superficial retina in the macular area and intraretinal edema suggested the diagnosis. Fluorescein angiography changes were similar in the two cases with enlargement of the foveal avascular zone and late staining of juxtafoveal vessels. OCT changes were suggestive of retinal ischemia: Increased reflectivity from the inner retinal layer and decreased backscattering from the retinal photoreceptors due to fluid and retinal edema. Ischemic maculopathy may cause a severe and permanent decrease in vision in AIDS patients. Fluorescein angiography and OCT should be considered in any patient with AIDS and unexplained visual loss. The mechanism of ischemic maculopathy may be multifactorial. PMID:27051496

  10. Novel Neuroprotective Strategies in Ischemic Retinal Lesions

    PubMed Central

    Szabadfi, Krisztina; Mester, Laszlo; Reglodi, Dora; Kiss, Peter; Babai, Norbert; Racz, Boglarka; Kovacs, Krisztina; Szabo, Aliz; Tamas, Andrea; Gabriel, Robert; Atlasz, Tamas

    2010-01-01

    Retinal ischemia can be effectively modeled by permanent bilateral common carotid artery occlusion, which leads to chronic hypoperfusion-induced degeneration in the entire rat retina. The complex pathways leading to retinal cell death offer a complex approach of neuroprotective strategies. In the present review we summarize recent findings with different neuroprotective candidate molecules. We describe the protective effects of intravitreal treatment with: (i) urocortin 2; (ii) a mitochondrial ATP-sensitive K+ channel opener, diazoxide; (iii) a neurotrophic factor, pituitary adenylate cyclase activating polypeptide; and (iv) a novel poly(ADP-ribose) polymerase inhibitor (HO3089). The retinoprotective effects are demonstrated with morphological description and effects on apoptotic pathways using molecular biological techniques. PMID:20386654

  11. Severe Hypokalemia Masquerading Myocardial Ischemia

    PubMed Central

    Petrov, Daniel Bogdanov; Sardovski, Svetlozar Ivanov; Milanova, Maria Hristova

    2012-01-01

    An advanced degree of body potassium deficit may produce striking changes in the electrocardiogram (ECG). These changes can result in incidental findings on the 12-lead ECG or precipitate potentially life-threatening dysrhythmias. Although usually readily recognized, at times these abnormalities may be confused with myocardial ischemia. The object was to report a case of severe hypokalemia mimicking myocardial ischemia. A 33-year-old, previously healthy man, presented to the Emergency Department (ED) with a progressive weakness and chest discomfort. The electrocardiogram showed a marked ST-segment depression in leads II, III, aVF, V1-V6. The initial diagnosis was non ST-elevation myocardial infarction. Echocardiography was normal and troponin levels were within normal limits. A more detailed history revealed that the patient had an episode of acute gastroenteritis with diarrhea and vomiting. Serum chemistries were notable for a potassium concentration of 1,8 mmol per liter. With aggressive electrolyte correction, the ECG abnormalities reverted as potassium levels normalized. Hypokalemia induced ST-segment depression may simulate myocardial ischemia. The differential diagnosis might be difficult, especially in the cases when ST changes are accompanied with chest discomfort.

  12. [Preventive effects of troxipide on a newly developed model of acute gastric mucosal lesion (AGML) induced by ischemia/reperfusion plus ammonia in the rat].

    PubMed

    Momo, K; Hoshina, K; Ishibashi, Y; Saito, T

    1994-10-01

    We have developed a unique rat AGML model produced by ischemia/reperfusion plus 0.2% ammonia (I/R.NH3), either treatment which would not induce mucosal injury when used alone. The effects of troxipide and other gastric mucosal defensive drugs were investigated with this I/R.NH3-induced AGML model and other AGML models in rats. The following results were obtained: 1) Like allopurinol, troxipide at 50-200 mg/kg, p.o. dose-dependently prevented I/R.NH3-induced development of AGML and also the ischemia/reperfusion-induced increase of gastric mucosal thiobarbituric acid (TBA)-reactive substances; 2) Troxipide at 10(-6)-10(-4) M, like allopurinol, inhibited concentration-dependently in vitro xanthine oxidase activity in gastric mucosal homogenates; 3) Troxipide at 50-200 mg/kg, p.o. inhibited AGMLs induced by bleeding plus 0.2% ammonia and by 1.0% ammonia alone; and 4) Troxipide and sofalcone were similar in preventing all AGMLs tested and also the increase of mucosal TBA-reactive substances, but somewhat differed from teprenone, cetraxate hydrochloride, azulene plus L-glutamine and sucralfate. These findings suggest that troxipide may inhibit I/R.NH3-induced AGML development by preventing generation of oxygen free radicals and by protecting against mucosal fragility due to reduced energy metabolism from poor blood flow and also against ammonia-induced disruption of the gastric mucosal barrier. Therefore, troxipide may be highly effective for various AGMLs with multifactor involvement.

  13. Role of systemic arterial pressure, heart rate, and derived variables in prediction of severity of myocardial ischemia during acute coronary occlusion in anesthetized dogs.

    PubMed

    Moore, P G; Reitan, J A; Kien, N D; White, D A; Safwat, A M

    1992-09-01

    The present study examined the postulate that the quotient of mean systemic arterial pressure and heart rate predicts the severity of myocardial ischemia during occlusion of the left anterior descending coronary artery. Studies were performed in open-chest fentanyl-anesthetized dogs before and during halothane (n = 8) or isoflurane (n = 8) anesthesia. The pressure-rate quotient (PRQ) decreased significantly in both groups during incremental increases in halothane or isoflurane to 68% and 57% of control values at 0.5 MAC and to 41% and 38% at 1.5 MAC for halothane and isoflurane, respectively. Myocardial lactate production was unchanged from the ischemic region, and no correlation between the PRQ and myocardial lactate production was observed. In contrast, heart rate correlated significantly (r = 0.376; P less than 0.05) with lactate production. The product of systolic systemic arterial pressure and heart rate (rate-pressure product) correlated with blood flow (r = 0.493; P less than 0.001) and with oxygen consumption (r = 0.571; P less than 0.001) in the normal myocardium. A weak correlation (r = 0.330; P less than 0.05) of rate-pressure product with myocardial lactate production from the ischemic region was observed. There were no correlations between the PRQ and myocardial lactate production from the ischemic region or indices of blood flow distribution (i.e., inner/outer ratio in the ischemic region or ischemic/normal ratio). The relationship of hemodynamic variables to measurements of regional myocardial metabolism was independent of background anesthetic agent of depth of anesthesia. The current data suggest that heart rate changes are weakly predictive of severity of myocardial ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Anti-inflammatory and antioxidant effects of curcumin on acute lung injury in a rodent model of intestinal ischemia reperfusion by inhibiting the pathway of NF-Kb

    PubMed Central

    Fan, Zhe; Yao, Jihong; Li, Yang; Hu, Xiaowei; Shao, Huizhu; Tian, Xiaofeng

    2015-01-01

    Objective: To investigate the anti-inflammatory and antioxidant effect of curcumin on lung lesion induced by intestinal ischemia reperfusion injury (IIR). Methods: Rats were divided into four groups: sham, intestinal IIR (IIR), 1 mg/kg of curcumin treatment group (1 mg/kg), and 5 mg/kg of curcumin treatment group (5 mg/kg). Curcumin was given respectively (1 mg/kg and 5 mg/kg) following the above doses. IIR was produced by 1 h of intestinal ischemia followed by 2 h of reperfusion. Rats were sacrificed at the end of reperfusion and lung tissues were collected for biochemical and histopathological examination in 4 groups. Lung tissues histology and bronchoalveolar lavage fluid (BALF) protein were assayed. Serum IL-6, lung superoxide dismutase (SOD) and myeloperoxidase (MPO) were measured. The expression level of NF-κB and ICAM-1 (including immunohistochemical analysis and western blot analysis) were also measured. Results: Lung tissue injury induced by IIR was obviously observed through pathology and BALF protein. MPO activity, IL-6 level and ICAM-1 expression were significantly increased with the elevation of NF-κB, simultaneously, SOD activity was decreased. With Treatment of curcumin, pathology and BALF protein of lung tissue were improved clearly. Inflammatory indexes (MPO activity, IL-6 level and ICAM-1) were improved and antioxidant index (SOD activity) was enhanced paralleled with NF-κB. Conclusion: Using curcumin effectively prevented IIR-induced lung injury. Anti-inflammatory and antioxidant effects of curcumin could be observed by inhibiting the pathway of NF-κB. PMID:26097529

  15. Hypoxia-Inducible Factor-1α Target Genes Contribute to Retinal Neuroprotection

    PubMed Central

    Cheng, Lin; Yu, Honghua; Yan, Naihong; Lai, Kunbei; Xiang, Mengqing

    2017-01-01

    Hypoxia-inducible factor (HIF) is a transcription factor that facilitates cellular adaptation to hypoxia and ischemia. Long-standing evidence suggests that one isotype of HIF, HIF-1α, is involved in the pathogenesis of various solid tumors and cardiac diseases. However, the role of HIF-1α in retina remains poorly understood. HIF-1α has been recognized as neuroprotective in cerebral ischemia in the past two decades. Additionally, an increasing number of studies has shown that HIF-1α and its target genes contribute to retinal neuroprotection. This review will focus on recent advances in the studies of HIF-1α and its target genes that contribute to retinal neuroprotection. A thorough understanding of the function of HIF-1α and its target genes may lead to identification of novel therapeutic targets for treating degenerative retinal diseases including glaucoma, age-related macular degeneration, diabetic retinopathy, and retinal vein occlusions. PMID:28289375

  16. Association of Diabetic Macular Nonperfusion With Outer Retinal Disruption on Optical Coherence Tomography

    PubMed Central

    Scarinci, Fabio; Jampol, Lee M.; Linsenmeier, Robert A.; Fawzi, Amani A.

    2015-01-01

    IMPORTANCE Diabetic macular nonperfusion leads to decreased perifoveal capillary blood flow, which in turn causes chronic ischemia of the retinal tissue. Using point-to-point correlation between spectral-domain optical coherence tomography (SD-OCT) and nonperfusion on fluorescein angiography, we observed that retinal capillary nonperfusion is associated with photoreceptor compromise on OCT. This study highlights a new concept of a possible contribution of the retinal deep capillary plexus to photoreceptor compromise in diabetic retinopathy in the absence of diabetic macular edema. OBJECTIVE To report outer retinal structural changes associated with enlargement of the foveal avascular zone and/or capillary nonperfusion in the macular area of diabetic patients. DESIGN, SETTING, AND PARTICIPANTS Retrospective observational cross-sectional study in 9 patients who were diagnosed as having diabetic retinopathy without diabetic macular edema and underwent fluorescein angiography and SD-OCT for diabetic retinopathy from July 8, 2014, to December 1, 2014, at a tertiary academic referral center. This analysis was conducted between December 2, 2014, and January 31, 2015. MAIN OUTCOMES AND MEASURES Outer retinal changes on SD-OCT in areas of macular ischemia. RESULTS The study included 13 eyes of 9 diabetic patients (4 men and 5 women aged 34–58 years) with a mean duration of diabetes mellitus of 14.5 years. Nine eyes showed outer retinal disruption revealed by SD-OCT that colocalized to areas of enlargement of the foveal avascular zone and macular capillary nonperfusion. Four fellow eyes with normal foveal avascular zones did not show any retinal changes on SD-OCT. CONCLUSIONS AND RELEVANCE Macular ischemia in diabetic patients can be associated with photoreceptor compromise. The presence of disruption of the photoreceptors on OCT in diabetic patients can be a manifestation of underlying capillary nonperfusion in eyes without diabetic macular edema. Ischemia at the deep

  17. Antioxidative and cardioprotective effects of total flavonoids extracted from Dracocephalum moldavica L. against acute ischemia/reperfusion-induced myocardial injury in isolated rat heart.

    PubMed

    Jiang, Jiangtao; Yuan, Xuan; Wang, Ting; Chen, Hongmei; Zhao, Hong; Yan, Xinyan; Wang, Zhiping; Sun, Xiling; Zheng, Qiusheng

    2014-03-01

    This study evaluates antioxidative and cardioprotective effects of total flavonoids extracted from Dracocephalum moldavica L. (DML). The total flavonoids showed remarkable scavenging effects against 1,1-diphenyl-2-picrylhydrazyl, hydroxyl and superoxide anion radicals in vitro. Compared with the ischemia/reperfusion (I/R) group as demonstrated by the use of improved Langendorff retrograde perfusion technology, the total flavonoids (5 μg/mL) pretreatment improved the heart rate and coronary flow, rised left ventricular developed pressure and decreased creatine kinase, lactate dehydrogenase levels in coronary flow. The infarct size/ischemic area at risk of DML-treated hearts was smaller than that of I/R group; the superoxide dismutase activity and glutathione/glutathione disulfide ratio increased and malondialdehyde content reduced obviously (P < 0.01) in total flavonoids treatment groups. In conclusion, the total flavonoids possess obvious protective effects on myocardial I/R injury, which may be related to the improvement of myocardial oxidative stress states.

  18. Cardioprotective Effects of Total Flavonoids Extracted from Xinjiang Sprig Rosa rugosa against Acute Ischemia/Reperfusion-Induced Myocardial Injury in Isolated Rat Heart.

    PubMed

    Hou, Xuejiao; Han, Jichun; Yuan, Changsheng; Ren, Huanhuan; Zhang, Ya; Zhang, Tao; Xu, Lixia; Zheng, Qiusheng; Chen, Wen

    2016-01-01

    This study evaluated the antioxidative and cardioprotective effects of total flavonoids extracted from Xinjiang sprig Rosa rugosa on ischemia/reperfusion (I/R) injury using an isolated Langendorff rat heart model. The possible mechanism of Xinjiang sprig rose total flavonoid (XSRTF) against I/R injury was also studied. XSRTF (5, 10, and 20 µg/mL) dissolved in Krebs-Henseleit buffer was administered to isolated rat heart. The XSRTF showed remarkable scavenging effects against 1,1-diphenyl-2-picrylhydrazyl, hydroxyl, and superoxide anion radicals in vitro. XSRTF pretreatment improved the heart rate, increased LVDP, and decreased CK and LDH levels in coronary flow. This pretreatment also increased SOD activity and GSH/GSSG ratio but decreased MDA, TNF-α, and CRP levels and IL-8 and IL-6 activities. The infarct size and cell apoptosis in the hearts from the XSRTF-treated group were lower than those in the hearts from the I/R group. Therefore, the cardioprotective effects of XSRTF may be attributed to its antioxidant, antiapoptotic, and anti-inflammatory activities.

  19. Ventricular premature beats on Holter monitoring in patients admitted with chest pain, in whom acute myocardial infarction is not confirmed. The prognostic value and relationship to scars or ischemia on thallium-201 scintigraphy

    SciTech Connect

    Madsen, J.K.; Sorensen, J.N.; Kromann-Andersen, B.; Kjeldgaard, K.M.; Christoffersen, K.; van Duijvendijk, K.; Reiber, J.H.

    1987-05-01

    Ambulatory 24-h Holter monitoring was carried out in 198 patients who had been admitted because of suspected acute myocardial infarction (AMI) due to chest pain, but in whom AMI was not confirmed. During a follow-up period of 12-24 months (median 14 months) 16 cardiac events (i.e., nonfatal AMI or cardiac death) occurred. Ventricular premature beats (VPBs) were found in 65.2% of the patients, complex VPBs in 28.8%. Pairs of VPBs which were seen in 10.0% of the patients were the only important type of VPBs significantly related to an impaired prognosis. Thallium-201 scintigraphy was performed in 144 of the patients. VPBs were significantly related to scar formation (i.e., to permanent defects, but not to ischemia, specifically, to transient defects). It is concluded that ventricular arrhythmias in this patient category indicate presence of chronic ischemic heart disease, and that pairs of VPBs seem to identify patients at risk for cardiac events.

  20. A Translational Study of a New Therapeutic Approach for Acute Myocardial Infarction: Nanoparticle-Mediated Delivery of Pitavastatin into Reperfused Myocardium Reduces Ischemia-Reperfusion Injury in a Preclinical Porcine Model

    PubMed Central

    Ichimura, Kenzo; Matoba, Tetsuya; Nakano, Kaku; Tokutome, Masaki; Honda, Katsuya; Koga, Jun-ichiro; Egashira, Kensuke

    2016-01-01

    Background There is an unmet need to develop an innovative cardioprotective modality for acute myocardial infarction, for which interventional reperfusion therapy is hampered by ischemia-reperfusion (IR) injury. We recently reported that bioabsorbable poly(lactic acid/glycolic acid) (PLGA) nanoparticle-mediated treatment with pitavastatin (pitavastatin-NP) exerts a cardioprotective effect in a rat IR injury model by activating the PI3K-Akt pathway and inhibiting inflammation. To obtain preclinical proof-of-concept evidence, in this study, we examined the effect of pitavastatin-NP on myocardial IR injury in conscious and anesthetized pig models. Methods and Results Eighty-four Bama mini-pigs were surgically implanted with a pneumatic cuff occluder at the left circumflex coronary artery (LCx) and telemetry transmitters to continuously monitor electrocardiogram as well as to monitor arterial blood pressure and heart rate. The LCx was occluded for 60 minutes, followed by 24 hours of reperfusion under conscious conditions. Intravenous administration of pitavastatin-NP containing ≥ 8 mg/body of pitavastatin 5 minutes before reperfusion significantly reduced infarct size; by contrast, pitavastatin alone (8 mg/body) showed no therapeutic effects. Pitavastatin-NP produced anti-apoptotic effects on cultured cardiomyocytes in vitro. Cardiac magnetic resonance imaging performed 4 weeks after IR injury revealed that pitavastatin-NP reduced the extent of left ventricle remodeling. Importantly, pitavastatin-NP exerted no significant effects on blood pressure, heart rate, or serum biochemistry. Exploratory examinations in anesthetized pigs showed pharmacokinetic analysis and the effects of pitavastatin-NP on no-reflow phenomenon. Conclusions NP-mediated delivery of pitavastatin to IR-injured myocardium exerts cardioprotective effects on IR injury without apparent adverse side effects in a preclinical conscious pig model. Thus, pitavastatin-NP represents a novel therapeutic

  1. Retinitis Pigmentosa and Other Dystrophies.

    PubMed

    Mrejen, Sarah; Audo, Isabelle; Bonnel, Sébastien; Sahel, José-Alain

    2017-01-01

    Retinitis pigmentosa (RP) is a heterogeneous group of inherited retinal degenerations characterized by progressive degeneration of rod and cone cells that affects predominantly peripheral visual fields. Macular edema may cause additional central visual acuity decrease. Cystoid macular edema (CME) is one of the few treatable causes of visual loss in RP. The prevalence of CME in RP has been found to be between 10 and 20% on fluorescein angiography-based studies, and as high as 49% on reports based on optical coherence tomography. Macular edema can manifest at any stage of the disease and may be unilateral or bilateral. It can be found in any genetic form, but is more often associated with RP caused by CRB1 mutations. The origin of macular edema in RP patients still remains poorly understood. Some mechanisms have been suggested, including antiretinal antibodies (retinal, carbonic anhydrase, and enolase antibodies), vitreous traction, retinal pigment epithelium dysfunction, and Müller cell edema. There is no gold standard therapeutic strategy. Drug therapy is the primary treatment. Systemic carbonic anhydrase inhibitors, such as oral acetazolamide or topical dorzolamide, are still the mainstays of initial therapy. If CME is refractory to acetazolamide, intravitreal corticosteroid injections may be a therapeutic option. However, antivascular endothelium growth factor injections have limited effect and should be avoided. Vitrectomy has also been evaluated, but its exact role remains to be determined. The benefits of these therapies are variable among patients. The establishment of therapeutic approaches is limited by our poor understanding of the pathophysiology of CME in patients with RP. Autoimmune retinopathies (AIRs) are a group of rare diseases characterized by acute or subacute progressive vision loss and are thought to be mediated by autoantibodies specific to retinal antigens. The AIRs encompass paraneoplastic syndromes, such as cancer-associated retinopathy and

  2. Myocardial ischemia and ventricular fibrillation: pathophysiology and clinical implications.

    PubMed

    Luqman, Nazar; Sung, Ruey J; Wang, Chun-Li; Kuo, Chi-Tai

    2007-07-31

    Ventricular fibrillation (VF) and myocardial ischemia are inseparable. The first clinical manifestation of myocardial ischemia or infarction may be sudden cardiac death in 20-25% of patients. The occurrence of potentially lethal arrhythmia is the end result of a cascade of pathophysiological abnormalities that result from complex interactions between coronary vascular events, myocardial injury, and changes in autonomic tone, metabolic conditions and ionic state of the myocardium. It is also related to the time from the onset of ischemia. Within the first few minutes there is abundant ventricular arrhythmogenesis usually lasting for 30 min. Triggers for ischemic VF occur at the border zone or regionally ischemic heart. The border zone of ischemia is the predominant site of fragmentation. Acute ischemia opens K(ATP) channels and causes acidosis and hypoxia of myocardial cells leading to a large dispersion in repolarization across the border zone. Abnormalities of intracellular Ca2+ handling also occur in the first few minutes of acute myocardial ischemia and may be an important cause of arrhythmias in human coronary artery disease. Substrate on the other hand transforms triggers into VF and serves to maintain it through fragmentation of waves in the ischemic zone. Thrombin levels, stretch, catecholamine, genetic predisposition, etc. are some of these factors. Reentry models described are spiral wave reentry, 3 dimensional rotors, reentry around 'M' cells and figure-of-eight reentry. Continuing efforts to better understand these arrhythmias will help identify patients of myocardial ischemia prone to arrhythmias.

  3. Inferior retinal light exposure is more effective than superior retinal exposure in suppressing melatonin in humans

    NASA Technical Reports Server (NTRS)

    Glickman, Gena; Hanifin, John P.; Rollag, Mark D.; Wang, Jenny; Cooper, Howard; Brainard, George C.

    2003-01-01

    Illumination of different areas of the human retina elicits differences in acute light-induced suppression of melatonin. The aim of this study was to compare changes in plasma melatonin levels when light exposures of equal illuminance and equal photon dose were administered to superior, inferior, and full retinal fields. Nine healthy subjects participated in the study. Plexiglass eye shields were modified to permit selective exposure of the superior and inferior halves of the retinas of each subject. The Humphrey Visual Field Analyzer was used both to confirm intact full visual fields and to quantify exposure of upper and lower visual fields. On study nights, eyes were dilated, and subjects were exposed to patternless white light for 90 min between 0200 and 0330 under five conditions: (1) full retinal exposure at 200 lux, (2) full retinal exposure at 100 lux, (3) inferior retinal exposure at 200 lux, (4) superior retinal exposure at 200 lux, and (5) a dark-exposed control. Plasma melatonin levels were determined by radioimmunoassay. ANOVA demonstrated a significant effect of exposure condition (F = 5.91, p < 0.005). Post hoc Fisher PLSD tests showed significant (p < 0.05) melatonin suppression of both full retinal exposures as well as the inferior retinal exposure; however, superior retinal exposure was significantly less effective in suppressing melatonin. Furthermore, suppression with superior retinal exposure was not significantly different from that of the dark control condition. The results indicate that the inferior retina contributes more to the light-induced suppression of melatonin than the superior retina at the photon dosages tested in this study. Findings suggest a greater sensitivity or denser distribution of photoreceptors in the inferior retina are involved in light detection for the retinohypothalamic tract of humans.

  4. Acute renal failure with severe loin pain and patchy renal ischemia after anaerobic exercise in patients with or without renal hypouricemia.

    PubMed

    Ishikawa, Isao

    2002-08-01

    Acute renal failure induced by rhabdomyolysis after strenuous exercise is well known. We describe here a new type of acute renal failure with severe loin pain which develops after anaerobic exercise (ALPE), for example, 200-meter track racing. The patients complained of severe loin pain several hours after exercise and presented at the emergency room. Since our first description 118 cases have been reported. The serum creatinine concentration was 4.7 +/- 2.9 mg/dl (mean +/- SD) at the initial examination and 6.0 +/- 3.0 mg/dl at maximum. Forty-nine of 96 cases whose serum uric acid levels were described revealed renal hypouricemia (51.0%). A specific risk factor is suggested by the fact that acute renal failure recurred after exercise in 20 of 118 cases. The creatine phosphokinase and serum myoglobin concentrations were normal or only slightly elevated, suggesting damaged type 2 muscle fibers. Renal computed tomography scans, performed several hours to 1-2 days after contrast medium administration, revealed multiple wedge-shaped areas of contrast enhancement. Forty-six of 50 cases examined by delayed computed tomography scan revealed bilateral wedge-shaped contrast enhancement. Although less efficient, radioisotopic scans, such as a methylene diphosphonate bone scan, have also been employed to detect patchy accumulation of isotopes in the kidneys (12 of 19 cases). The pathogenesis of ALPE may be patchy vasoconstriction of the renal vessels, because of its wedge-shaped distribution and its reversibility. Such vascular spasm would account for the renal pain. The prognosis was good, although 20 of 109 cases required dialysis treatment. In conclusion, there are two types of exercise-induced acute renal failure: one is the well-known myoglobin-induced acute renal failure, and the other is ALPE that may be nonmyoglobin induced or induced by myolysis of type 2 muscle fibers due to anaerobic exercise. One hundred and eighteen cases of ALPE were collected from the

  5. Retinal remodeling in human retinitis pigmentosa.

    PubMed

    Jones, B W; Pfeiffer, R L; Ferrell, W D; Watt, C B; Marmor, M; Marc, R E

    2016-09-01

    Retinitis Pigmentosa (RP) in the human is a progressive, currently irreversible neural degenerative disease usually caused by gene defects that disrupt the function or architecture of the photoreceptors. While RP can initially be a disease of photoreceptors, there is increasing evidence that the inner retina becomes progressively disorganized as the outer retina degenerates. These alterations have been extensively described in animal models, but remodeling in humans has not been as well characterized. This study, using computational molecular phenotyping (CMP) seeks to advance our understanding of the retinal remodeling process in humans. We describe cone mediated preservation of overall topology, retinal reprogramming in the earliest stages of the disease in retinal bipolar cells, and alterations in both small molecule and protein signatures of neurons and glia. Furthermore, while Müller glia appear to be some of the last cells left in the degenerate retina, they are also one of the first cell classes in the neural retina to respond to stress which may reveal mechanisms related to remodeling and cell death in other retinal cell classes. Also fundamentally important is the finding that retinal network topologies are altered. Our results suggest interventions that presume substantial preservation of the neural retina will likely fail in late stages of the disease. Even early intervention offers no guarantee that the interventions will be immune to progressive remodeling. Fundamental work in the biology and mechanisms of disease progression are needed to support vision rescue strategies.

  6. Genetics Home Reference: retinitis pigmentosa

    MedlinePlus

    ... Me Understand Genetics Home Health Conditions retinitis pigmentosa retinitis pigmentosa Enable Javascript to view the expand/collapse boxes. Download PDF Open All Close All Description Retinitis pigmentosa is a group of related eye disorders that ...

  7. Systemic viral infections and their retinal and choroidal manifestations.

    PubMed

    Yoser, S L; Forster, D J; Rao, N A

    1993-01-01

    Viruses are one of the most common causes of infections involving the posterior segment of the eye. Such infections can occur either on a congenital or an acquired basis, and may affect primarily the retina or the choroid. Congenital cytomegalovirus (CMV) and rubella infections may result in retinitis. CMV retinitis is also the most common cause of acquired viral retinitis, primarily because of the acquired immunodeficiency syndrome (AIDS). Other types of viral retinitis, such as those caused by herpes simplex or herpes zoster, can occur in immunocompromised or immunocompetent individuals. Retinitis or choroiditis caused by viruses such as measles, influenza, Epstein-Barr virus, and Rift Valley fever virus, typically occurs subsequent to an acute viral systemic illness. The systemic and ocular manifestations, as well as the histopathology, laboratory tests, differential diagnoses, and treatment regimens for each of the individual viruses are discussed in detail.

  8. Hemi-central retinal artery occlusion in young adults.

    PubMed

    Rishi, Pukhraj; Rishi, Ekta; Sharma, Tarun; Mahajan, Sheshadri

    2010-01-01

    Amongst the clinical presentations of retinal artery occlusion, hemi-central retinal artery occlusion (Hemi-CRAO) is rarely described. This case series of four adults aged between 22 and 36 years attempts to describe the clinical profile, etiology and management of Hemi-CRAO. Case 1 had an artificial mitral valve implant. Polycythemia and malignant hypertension were noted in Case 2. The third patient had Leiden mutation while the fourth patient had Eisenmenger's syndrome. Clinical examination and fundus fluorescein angiography revealed a bifurcated central retinal artery at emergence from the optic nerve head, in all cases. Color Doppler examination of the central retinal artery confirmed branching of the artery behind the lamina cribrosa. It is hypothesized that bifurcation of central retinal artery behind the lamina cribrosa may predispose these hemi-trunks to develop an acute occlusion if associated with underlying risk factors. The prognosis depends upon arterial recanalisation and etiology of the thromboembolic event.

  9. Inhibition of BDNF-AS Provides Neuroprotection for Retinal Ganglion Cells against Ischemic Injury

    PubMed Central

    Xu, Lifang; Zhang, Ziyin; Xie, Tianhua; Zhang, Xiaoyang; Dai, Tu

    2016-01-01

    Background: Brain-derived neurotrophic factor (BDNF) protects retinal ganglion cells against ischemia in ocular degenerative diseases. We aimed to determine the effect of BDNF-AS on the ischemic injury of retinal ganglion cells. Methods: The levels of BDNF and BDNF-AS were measured in retinal ganglion cells subjected to oxygen and glucose deprivation. The lentiviral vectors were constructed to either overexpress or knock out BDNF-AS. The luciferase reporter gene assay was used to determine whether BDNF-AS could target its seed sequence on BDNF mRNA. The methyl thiazolyl tetrazolium assay was used to determine cell viability, and TUNEL staining was used for cell apoptosis. Results: The levels of BDNF-AS were negatively correlated with BDNF in ischemic retinal ganglion cells. BDNF-AS directly targeted its complementary sequences on BDNF mRNA. BDNF-AS regulated the expression of BDNF and its related genes in retinal ganglion cells. Down-regulation of BDNF-AS increased cell viability and decreased the number of TUNEL-positive retinal ganglion cells under oxygen and glucose deprivation conditions. Conclusion: Inhibition of BDNF-AS protected retinal ganglion cells against ischemia by increasing the levels of BDNF. PMID:27935942

  10. Retinal detachment repair

    MedlinePlus

    Scleral buckling; Vitrectomy; Pneumatic retinopexy; Laser retinopexy; Rhegmatogenous retinal detachment repair ... it meets the hole in the retina. Scleral buckling can be done using numbing medicine while you ...

  11. Use of the Trellis{sup TM} Peripheral Infusion System for Enhancement of rt-PA Thrombolysis in Acute Lower Limb Ischemia

    SciTech Connect

    Tsetis, Dimitrios K. Katsamouris, Asterios N.; Androulakakis, Zacharias; Chamalakis, Konstantinos; Kostas, Theodoros; Chlapoutakis, Konstantinos; Gourtsoyiannis, Nicholas C.

    2003-11-15

    The Trellis{sup TM} Peripheral Infusion System is an over-the-wire 0.035'' guidewire compatible device, designed to isolate a region of the peripheral vasculature to allow for lytic drug infusion and dispersion. We used it successfully through a percutaneous approach in two cases of acute thrombosis of a native lower limb artery. The total amount of rt-PA used was 12 and 9 mg, respectively and was delivered through bolus injections obviating the need for a supplementary continuous infusion of the agent. The time for dissolution of thrombus was 45 and 35 minutes, respectively. No complications were observed.

  12. Epoxygenated Fatty Acids Inhibit Retinal Vascular Inflammation

    PubMed Central

    Capozzi, Megan E.; Hammer, Sandra S.; McCollum, Gary W.; Penn, John S.

    2016-01-01

    The objective of the present study was to assess the effect of elevating epoxygenated fatty acids on retinal vascular inflammation. To stimulate inflammation we utilized TNFα, a potent pro-inflammatory mediator that is elevated in the serum and vitreous of diabetic patients. In TNFα-stimulated primary human retinal microvascular endothelial cells, total levels of epoxyeicosatrienoic acids (EETs), but not epoxydocosapentaenoic acids (EDPs), were significantly decreased. Exogenous addition of 11,12-EET or 19,20-EDP when combined with 12-(3-adamantane-1-yl-ureido)-dodecanoic acid (AUDA), an inhibitor of epoxide hydrolysis, inhibited VCAM-1 and ICAM-1 expression and protein levels; conversely the diol product of 19,20-EDP hydrolysis, 19,20-DHDP, induced VCAM1 and ICAM1 expression. 11,12-EET and 19,20-EDP also inhibited leukocyte adherence to human retinal microvascular endothelial cell monolayers and leukostasis in an acute mouse model of retinal inflammation. Our results indicate that this inhibition may be mediated through an indirect effect on NFκB activation. This is the first study demonstrating a direct comparison of EET and EDP on vascular inflammatory endpoints, and we have confirmed a comparable efficacy from each isomer, suggesting a similar mechanism of action. Taken together, these data establish that epoxygenated fatty acid elevation will inhibit early pathology related to TNFα-induced inflammation in retinal vascular diseases. PMID:27966642

  13. Central retinal artery occlusion (reversible in sickle trait with glaucoma.

    PubMed Central

    Radius, R L; Finkelstein, D

    1976-01-01

    We report a case of central retinal artery occlusion in an 18-year-old black woman with sickle-trait haemoglobinopathy and acute glaucoma after hyphaema. The central retinal artery occlusion occurred immediately after treatment of the glaucoma with osmotic agents, raising the possibility that they played a precipitating role. We suggest that osmotic agents be used with extreme caution in sickle patients with glaucoma. The occlusion was treated by anterior chamber paracentesis with eventual return of good vision. The reversibility of retinal and optic nerve function after total ischaemia is discussed. PMID:952815

  14. Molecular Pathogenesis of Retinal and Choroidal Vascular Diseases

    PubMed Central

    Campochiaro, Peter A.

    2015-01-01

    There are two major types of ocular neovascularization that affect the retina, retinal neovascularization (NV) and subretinal or choroidal NV. Retinal NV occurs in a group of diseases referred to as ischemic retinopathies in which damage to retinal vessels results in retinal ischemia. Most prevalent of these are diabetic retinopathy and retinal vein occlusions. Subretinal and choroidal NV occur in diseases of the outer retina and Bruch’s membrane, the most prevalent of which is age-related macular degeneration. Numerous studies in mouse models have helped to elucidate the molecular pathogenesis underlying retinal, subretinal, and choroidal NV. There is considerable overlap because the precipitating event in each is stabilization of hypoxia inducible factor-1 (HIF-1) which leads to upregulation of several hypoxia-regulated gene products, including vascular endothelial growth factor (VEGF), angiopoietin 2, vascular endothelial-protein tyrosine phosphatase (VE-PTP), and several others. Stimulation of VEGF signaling and suppression of Tie2 by angiopoietin 2 and VE-PTP are critical for sprouting of retinal, subretinal, and choroidal NV, with perturbation of Bruch’s membrane also needed for the latter. Additional HIF-1-regulated gene products cause further stimulation of the NV. It is difficult to model macular edema in animals and therefore proof-of-concept clinical trials were done and demonstrated that VEGF plays a central role and that suppression of Tie2 is also important. Neutralization of VEGF is currently the first line therapy for all of the above disease processes, but new treatments directed at some of the other molecular targets, particularly stabilization of Tie2, are likely to provide additional benefit for subretinal/choroidal NV and macular edema. In addition, the chronicity of these diseases as well as the implication of VEGF as a cause of retinal nonperfusion and progression of background diabetic retinopathy make sustained delivery approaches for

  15. Late reperfusion of a totally occluded infarct-related artery increases granulocyte-colony stimulation factor and reduces stroma-derived factor-1alpha blood levels in patients with ongoing ischemia after acute myocardial infarction.

    PubMed

    Kuo, Li-Tang; Chen, Shih-Jen; Cherng, Wen-Jin; Yang, Ning-I; Lee, Chen-Chin; Cheng, Chi-Wen; Verma, Subodh; Wang, Chao-Hung

    2009-07-01

    After acute myocardial infarction (AMI), reopening of a totally occluded infarct-related artery (IRA) at a subacute stage is still controversial in symptom-free patients. However, in patients with persistent ischemic symptoms and inadequate collaterals to the infarct area, recanalization is thought to provide beneficial effects. In addition to augmenting myocardial perfusion, we hypothesized that the benefit of recanalization involves the manipulation of circulating stem cell-mobilizing cytokines. This study included 30 patients with a totally occluded IRA and ongoing ischemic symptoms (the study group) and 30 patients with a partially occluded IRA (the control group). All patients underwent successful angioplasty and/or stenting. Before and immediately after the coronary intervention, blood granulocyte-colony-stimulating factor (G-CSF), stem-cell factor (SCF), vascular endothelial growth factor (VEGF), and stroma-derived factor-1 (SDF-1alpha) were measured. After recanalization, G-CSF levels significantly increased in the study group compared to the control group (P=0.03). SDF-1alpha levels in the study group decreased relative to the controls (P=0.02). However, no significant changes in VEGF or SCF levels between the two groups were found. In the multivariate analysis, reopening of a totally occluded IRA was independently and significantly associated with changes in G-CSF and SDF-1alpha levels after recanalization. In conclusion, our data suggest that the benefits of late reperfusion of a totally occluded IRA in patients with ongoing myocardial ischemia may involve mechanisms associated with stem cell-mobilizing and plaque-stabilizing cytokines. This study provides the rationale to investigate serial changes in cytokines and the numbers of circulating progenitors after reperfusion in the future.

  16. Pharmacotherapies for Retinal Detachment.

    PubMed

    Wubben, Thomas J; Besirli, Cagri G; Zacks, David N

    2016-07-01

    Retinal detachment is an important cause of visual loss. Currently, surgical techniques, including vitrectomy, scleral buckle, and pneumatic retinopexy, are the only means to repair retinal detachment and restore vision. However, surgical failure rates may be as high as 20%, and visual outcomes continue to vary secondary to multiple processes, including postoperative cystoid macular edema, epiretinal membrane formation, macular folds, and, ultimately, photoreceptor death. Therefore, pharmacotherapies are being sought to aid the success rates of modern surgical techniques and reduce or slow the degeneration of photoreceptors during retinal detachment. This review discusses potential therapeutic avenues that aid in retinal reattachment, reduce the rate of retinal redetachment by limiting proliferative vitreoretinopathy, and protect against photoreceptor cell death.

  17. Critical Limb Ischemia (CLI)

    MedlinePlus

    ... High blood pressure Family history of vascular disease Warning Signs You may have critical limb ischemia if ... blood flow to the limb. Other treatments include laser atherectomy, where small bits of plaque are vaporized ...

  18. Management of a subclavian artery thrombosis causing acute anterior wall infarction and concurrent left arm ischemia in a patient with prior coronary bypass.

    PubMed

    Akgüllü, Çağdaş; Eryılmaz, Ufuk; Zencir, Cemil; Güngör, Hasan

    2014-12-01

    We report a 57-year-old patient with acute anterior wall infarction with a history of a coronary baypass graft operation in 2007. He also had concurrent left arm cyanosis and severe pain. He had received diagnosis of pancreatic adenocarcinoma one month previously and had had his first chemotherapy in the previous week with gemcitabine and 5-fluorouracil. After the angiography, a giant thrombus was detected in the proximal left subclavian artery, deteriorating the flows of both left internal mammarian artery (LIMA) to left anterior descending (LAD) coronary artery graft, as well as the left brachial artery. The proximal subclavian artery was stented and good flow was achieved. Through the LIMA, the distal part of LAD, which was totally obstructed with probable distal thrombus embolization, was reached and a percutaneous balloon angioplasty performed. However, the no-reflow phenomenon was observed in distal LAD. A Fogarty traction of thrombus was performed successfully for the revascularization of the left arm. Approximately 30 minutes after the procedure, both angina and ST segment elevation in ECG were resolved under unfractioned heparin and nitroglycerin infusion. However, the patient died due to sepsis seven days after admission to hospital. In the literature, there are only a few previous reports on this rare clinical entity. The eitology, presentation, and the possible management strategies of this clinical entity is presented in this report.

  19. Arginase 2 promotes neurovascular degeneration during ischemia/reperfusion injury

    PubMed Central

    Shosha, Esraa; Xu, Zhimin; Yokota, Harumasa; Saul, Alan; Rojas, Modesto; Caldwell, R William; Caldwell, Ruth B; Narayanan, S Priya

    2016-01-01

    Retinal ischemia is a major cause of visual impairment and blindness and is involved in various disorders including diabetic retinopathy, glaucoma, optic neuropathies and retinopathy of prematurity. Neurovascular degeneration is a common feature of these pathologies. Our lab has previously reported that the ureahydrolase arginase 2 (A2) is involved in ischemic retinopathies. Here, we are introducing A2 as a therapeutic target to prevent neurovascular injury after retinal ischemia/reperfusion (I/R) insult. Studies were performed with mice lacking both copies of A2 (A2−/−) and wild-type (WT) controls (C57BL6J). I/R insult was conducted on the right eye and the left eye was used as control. Retinas were collected for analysis at different times (3 h–4 week after injury). Neuronal and microvascular degeneration were evaluated using NeuN staining and vascular digests, respectively. Glial activation was evaluated by glial fibrillary acidic protein expression. Necrotic cell death was studied by propidium iodide labeling and western blot for RIP-3. Arginase expression was determined by western blot and quantitative RT-PCR. Retinal function was determined by electroretinography (ERG). A2 mRNA and protein levels were increased in WT I/R. A2 deletion significantly reduced ganglion cell loss and microvascular degeneration and preserved retinal morphology after I/R. Glial activation, reactive oxygen species formation and cell death by necroptosis were significantly reduced by A2 deletion. ERG showed improved positive scotopic threshold response with A2 deletion. This study shows for the first time that neurovascular injury after retinal I/R is mediated through increased expression of A2. Deletion of A2 was found to be beneficial in reducing neurovascular degeneration after I/R. PMID:27882947

  20. Myocardial ischemia reperfusion injury: from basic science to clinical bedside.

    PubMed

    Frank, Anja; Bonney, Megan; Bonney, Stephanie; Weitzel, Lindsay; Koeppen, Michael; Eckle, Tobias

    2012-09-01

    Myocardial ischemia reperfusion injury contributes to adverse cardiovascular outcomes after myocardial ischemia, cardiac surgery or circulatory arrest. Primarily, no blood flow to the heart causes an imbalance between oxygen demand and supply, named ischemia (from the Greek isch, restriction; and haema, blood), resulting in damage or dysfunction of the cardiac tissue. Instinctively, early and fast restoration of blood flow has been established to be the treatment of choice to prevent further tissue injury. Indeed, the use of thrombolytic therapy or primary percutaneous coronary intervention is the most effective strategy for reducing the size of a myocardial infarct and improving the clinical outcome. Unfortunately, restoring blood flow to the ischemic myocardium, named reperfusion, can also induce injury. This phenomenon was therefore termed myocardial ischemia reperfusion injury. Subsequent studies in animal models of acute myocardial infarction suggest that myocardial ischemia reperfusion injury accounts for up to 50% of the final size of a myocardial infarct. Consequently, many researchers aim to understand the underlying molecular mechanism of myocardial ischemia reperfusion injury to find therapeutic strategies ultimately reducing the final infarct size. Despite the identification of numerous therapeutic strategies at the bench, many of them are just in the process of being translated to bedside. The current review discusses the most striking basic science findings made during the past decades that are currently under clinical evaluation, with the ultimate goal to treat patients who are suffering from myocardial ischemia reperfusion-associated tissue injury.

  1. Anti-VEGF treatment and peripheral retinal nonperfusion in patients with central retinal vein occlusion

    PubMed Central

    Abri Aghdam, Kaveh; Reznicek, Lukas; Soltan Sanjari, Mostafa; Klingenstein, Annemarie; Kernt, Marcus; Seidensticker, Florian

    2017-01-01

    Purpose To evaluate the association between the size of peripheral retinal nonperfusion and the number of intravitreal ranibizumab injections in patients with treatment-naïve central retinal vein occlusion (CRVO). Methods Fifty-four patients with treatment-naïve CRVO and macular edema were included. Each patient underwent a full ophthalmologic examination including optical coherence tomography imaging and ultrawide-field fluorescein angiography. Monthly intravitreal ranibizumab injections were applied according to the recommendations of the German Ophthalmologic Society. Two ophthalmologists quantified the areas of peripheral retinal nonperfusion (group 1= less than five disc areas, group 2= more than five disc areas). Correlation analyses between the size of nonperfusion with best-corrected visual acuity, central subfield thickness, and the number of intravitreal injections were performed. Results Best-corrected visual acuity improved significantly after intravitreal injections (P<0.001, both groups). Final central subfield thickness after treatment did not significantly differ between both groups (P=0.92, P=0.96, respectively). Mean number of injections in group 1 and group 2 was 4.12±2.73 and 9.32±3.84, respectively (P<0.001). There was a significant positive correlation between areas of nonperfusion and the number of injections in each group. (R=0.97, P<0.001; R=0.94, P<0.001, respectively). Conclusion Peripheral retinal nonperfusion in patients with CRVO correlates significantly with the number of needed intravitreal ranibizumab injections. Ultrawide-field fluorescein angiography is a useful tool for detection of peripheral retinal ischemia, which may have direct implications in the diagnosis, follow-up, and treatment of these patients. PMID:28243056

  2. Fluorometry of ischemia reperfusion injury in rat lungs in vivo

    NASA Astrophysics Data System (ADS)

    Sepehr, R.; Staniszewski, K.; Jacobs, E. R.; Audi, S.; Ranji, Mahsa

    2013-02-01

    Previously we demonstrated the utility of optical fluorometry to evaluate lung tissue mitochondrial redox state in isolated perfused rats lungs under various chemically-induced respiratory states. The objective of this study was to evaluate the effect of acute ischemia on lung tissue mitochondrial redox state in vivo using optical fluorometry. Under ischemic conditions, insufficient oxygen supply to the mitochondrial chain should reduce the mitochondrial redox state calculated from the ratio of the auto-fluorescent mitochondrial metabolic coenzymes NADH (Nicotinamide Adenine Dinucleotide) and FAD (Flavoprotein Adenine Dinucleotide). The chest of anesthetized, and mechanically ventilated Sprague-Dawley rat was opened to induce acute ischemia by clamping the left hilum to block both blood flow and ventilation to one lung for approximately 10 minutes. NADH and FAD fluorescent signals were recorded continuously in a dark room via a fluorometer probe placed on the pleural surface of the left lung. Acute ischemia caused a decrease in FAD and an increase in NADH, which resulted in an increase in the mitochondrial redox ratio (RR=NADH/FAD). Restoration of blood flow and ventilation by unclamping the left hilum returned the RR back to its baseline. These results (increase in RR under ischemia) show promise for the fluorometer to be used in a clinical setting for evaluating the effect of pulmonary ischemia-reperfusion on lung tissue mitochondrial redox state in real time.

  3. Retinal research using the perfused mammalian eye.

    PubMed

    Niemeyer, G

    2001-05-01

    The effort to isolate and maintain alive in vitro an intact mammalian eye is rewarded by the full control provided over the arterial input and exclusion of systemic regulatory or compensatory mechanisms. Electrical recording of typical light-evoked field potentials from retina and optic nerve can be complemented by single-cell recording. Thus, light-induced electrical activity reflects the function of the retinal pigment epithelium, of the layers of the retina and of the ganglion cells or their axons. Retinal function in vitro is documented by electrophysiological and morphological methods revealing subtle features of retinal information processing as well as optic nerve signals that approach-at threshold stimulus intensity-the human psychophysical threshold. Such sensitivity of third-order retinal neurons is described for the first time. This well controlled in vitro preparation has been used successfully for biophysical, metabolic and pharmacological studies. Examples are provided that demonstrate the marked sensibility of the rod system to changes in glucose supply. Moreover, histochemical identification of glycogen stores revealed labeling of the second- and third-order neurons subserving the rod system, in addition to labeling of Müller (glial) cells in the cat retina. The glycogen content of the cat retina is augmented by prolonged anesthesia, largely depleted by ischemia after enucleation and enhanced by insulin. Pharmacological experiments using agonists and antagonists of putative retinal neurotransmitters are summarized and outlined using the muscarinic cholinergic agonist QNB as an example. Actions and uptake of the neuromodulator adenosine are presented in detail, including inhibitory effects on physiologically characterized ganglion cells. Neuronal effects of adenosine are distinguished from those resulting from vasodilatation and from glycogenolysis induced by the neuromodulator. To open the blood-retina barrier, a hyperosmotic challenge can be

  4. Diosmin Protects Rat Retina from Ischemia/Reperfusion Injury

    PubMed Central

    Tong, Nianting; Zhang, Zhenzhen; Gong, Yuanyuan; Yin, Lili

    2012-01-01

    Abstract Objective Diosmin, a natural flavone glycoside, possesses antioxidant activity and has been used to alleviate ischemia/reperfusion (I/R) injury. The aim of this study was to clarify whether the administration of diosmin has a protective effect against I/R injury induced using the high intraocular pressure (IOP) model in rat retina, and to determine the possible antioxidant mechanisms involved. Methods Retinal I/R injury was induced in the rats by elevating the IOP to 110 mmHg for 60 min. Diosmin (100 mg/kg) or vehicle solution was administered intragastrically 30 min before the onset of ischemia and then daily after I/R injury until the animals were sacrificed. The levels of malondialdehyde (MDA) and the activities of total-superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in the retinal tissues were determined 24 h after I/R injury. At 7 days post-I/R injury, electroretinograms (ERGs) were recorded, and the density of surviving retinal ganglion cells (RGCs) was estimated by counting retrograde tracer-labeled cells in whole-mounted retinas. Retinal histological changes were also examined and quantified using light microscopy. Results Diosmin significantly decreased the MDA levels and increased the activities of T-SOD, GSH-Px, and CAT in the retina of rats compared with the ischemia group (P<0.05), and suppressed the I/R-induced reduction in the a- and b-wave amplitudes of the ERG (P<0.05). The thickness of the entire retina, inner nuclear layer, inner plexiform layer, and outer retinal layer and the number of cells in the ganglion cell layer were significantly less after I/R injury (P<0.05), and diosmin remarkably ameliorated these changes on retinal morphology. Diosmin also attenuated the I/R-induced loss of RGCs of the rat retina (P<0.05). Conclusion Diosmin protected the retina from I/R injury, possibly via a mechanism involving the regulation of oxidative parameters. PMID:22509733

  5. Retinal vascular regeneration.

    PubMed

    Otani, Atsushi; Friedlander, Martin

    2005-01-01

    We discuss the potential use of stem cells for therapeutic angiogenesis in the treatment of retinal diseases. We demonstrate that the clinical utility of these EPC may be not limited in the treatment of ischemic retinal diseases but may also have application for the treatment of retinal degenerative disorders and for a form of cell-based gene therapy. One of the greatest potential benefits of bone marrow derived EPC therapy is the possible use of autologous grafts. Nonetheless, potential toxicities and unregulated cell growth will need to be carefully evaluated before this approach is brought to the clinics.

  6. Retinal oximetry in patients with ischaemic retinal diseases.

    PubMed

    Rilvén, Sandra; Torp, Thomas Lee; Grauslund, Jakob

    2017-03-01

    The retinal oximeter is a new tool for non-invasive measurement of retinal oxygen saturation in humans. Several studies have investigated the associations between retinal oxygen saturation and retinal diseases. In the present systematic review, we examine whether there are associations between retinal oxygen saturation and retinal ischaemic diseases. We used PubMed and Embase to search for retinal oxygen saturation and retinal ischaemic diseases. Three separate searches identified a total of 79 publications. After two levels of manual screening, 10 studies were included: six about diabetic retinopathy (DR) and four about retinal vein occlusion. No studies about retinal artery occlusion were included. In diabetes, all studies found that increases in retinal venous oxygen saturation (rvSatO2 ) were associated with present as well as increasing levels of DR. Four of six studies also found increased retinal arterial oxygen saturation (raSatO2 ) in patients with DR. In patients with central retinal vein occlusion (CRVO), all studies found that rvSatO2 was reduced, but raSatO2 remained unchanged. Branch retinal vein occlusion was not associated with changes in retinal oxygen saturation, but this was based on a single study. In conclusion, DR is associated with increased rvSatO2 and might also be related to increased raSatO2 . Central retinal vein occlusion (CRVO) is correlated with increased rvSatO2 but unrelated to raSatO2 . Prospective studies are needed to expand these findings. These would tell whether retinal oximetry could be a potential tool for screening or a biomarker of treatment outcome in patients with ischaemic retinal diseases.

  7. Spinal cord ischemia secondary to hypovolemic shock.

    PubMed

    Oh, Jacob Yl; Kapoor, Siddhant; Koh, Roy Km; Yang, Eugene Wr; Hee, Hwan-Tak

    2014-12-01

    A 44-year-old male presented with symptoms of spinal cord compression secondary to metastatic prostate cancer. An urgent decompression at the cervical-thoracic region was performed, and there were no complications intraoperatively. Three hours postoperatively, the patient developed acute bilateral lower-limb paralysis (motor grade 0). Clinically, he was in class 3 hypovolemic shock. An urgent magnetic resonance imaging (MRI) was performed, showing no epidural hematoma. He was managed aggressively with medical therapy to improve his spinal cord perfusion. The patient improved significantly, and after one week, he was able to regain most of his motor functions. Although not commonly reported, spinal cord ischemia post-surgery should be recognized early, especially in the presence of hypovolemic shock. MRI should be performed to exclude other potential causes of compression. Spinal cord ischemia needs to be managed aggressively with medical treatment to improve spinal cord perfusion. The prognosis depends on the severity of deficits, and is usually favorable.

  8. Identification of intestinal wall abnormalities and ischemia by modeling spatial uncertainty in computed tomography imaging findings.

    PubMed

    Tsunoyama, Taichiro; Pham, Tuan D; Fujita, Takashi; Sakamoto, Tetsuya

    2014-10-01

    Intestinal abnormalities and ischemia are medical conditions in which inflammation and injury of the intestine are caused by inadequate blood supply. Acute ischemia of the small bowel can be life-threatening. Computed tomography (CT) is currently a gold standard for the diagnosis of acute intestinal ischemia in the emergency department. However, the assessment of the diagnostic performance of CT findings in the detection of intestinal abnormalities and ischemia has been a difficult task for both radiologists and surgeons. Little effort has been found in developing computerized systems for the automated identification of these types of complex gastrointestinal disorders. In this paper, a geostatistical mapping of spatial uncertainty in CT scans is introduced for medical image feature extraction, which can be effectively applied for diagnostic detection of intestinal abnormalities and ischemia from control patterns. Experimental results obtained from the analysis of clinical data suggest the usefulness of the proposed uncertainty mapping model.

  9. Retinal detachment in pseudophakia.

    PubMed

    Galin, M A; Poole, T A; Obstbaum, S A

    1979-07-01

    In a series of cataract patients excluding myopic individuals, under age 60 years, and cases in which vitreous loss occurred, retinal detachment was no less frequent after intracapsular cataract extraction and Sputnik iris supported lenses than in controls. Both groups were followed up for a minimum of two years. The detachments predominantly occurred from retinal breaks in areas of the retina that looked normal preoperatively.

  10. Retinal dysplasia of holoprosencephaly.

    PubMed

    Gorovoy, Ian R; Layer, Noelle; de Alba Campomanes, Alejandra G

    2014-03-04

    Retinal dysplasia occurs in the setting of sporadic and syndromic holoprosencephaly, which often has associated ocular malformations. The pathology of this dysplasia, which includes rosettes, has been previously described. However, its funduscopic findings have not been well documented. The authors present the fundus images of a patient with severe holoprosencephaly with retinal dysplasia and bilateral optic nerve colobomas that resulted in death 2 weeks after birth.

  11. Experimental Branch Retinal Vein Occlusion Induces Upstream Pericyte Loss and Vascular Destabilization

    PubMed Central

    Dominguez, Elisa; Raoul, William; Calippe, Bertrand; Sahel, José-Alain; Guillonneau, Xavier; Paques, Michel; Sennlaub, Florian

    2015-01-01

    Aims Branch retinal vein occlusion (BRVO) leads to extensive vascular remodeling and is important cause of visual impairment. Although the vascular morphological changes following experimental vein occlusion have been described in a variety of models using angiography, the underlying cellular events are ill defined. Methods and Results We here show that laser-induced experimental BRVO in mice leads to a wave of TUNEL-positive endothelial cell (EC) apoptosis in the upstream vascular network associated with a transient edema and hemorrhages. Subsequently, we observe an induction of EC proliferation within the dilated vein and capillaries, detected by EdU incorporation, and the edema resolves. However, the pericytes of the upstream capillaries are severely reduced, which was associated with continuing EC apoptosis and proliferation. The vascular remodeling was associated with increased expression of TGFβ, TSP-1, but also FGF2 expression. Exposure of the experimental animals to hypoxia, when pericyte (PC) dropout had occurred, led to a dramatic increase in endothelial cell proliferation, confirming the vascular instability induced by the experimental BRVO. Conclusion Experimental BRVO leads to acute endothelial cells apoptosis and increased permeability. Subsequently the upstream vascular network remains destabilized, characterized by pericyte dropout, un-physiologically high endothelial cells turnover and sensitivity to hypoxia. These early changes might pave the way for capillary loss and subsequent chronic ischemia and edema that characterize the late stage disease. PMID:26208283

  12. [Cerebral ischemia and histamine].

    PubMed

    Adachi, Naoto

    2002-10-01

    Cerebral ischemia induces excess release of glutamate and an increase in the intracellular Ca2+ concentration, which provoke catastrophic enzymatic processes leading to irreversible neuronal injury. Histamine plays the role of neurotransmitter in the central nervous system, and histaminergic fibers are widely distributed in the brain. In cerebral ischemia, release of histamine from nerve endings has been shown to be enhanced by facilitation of its activity. An inhibition of the histaminergic activity in ischemia aggravates the histologic outcome. In contrast, intracerebroventricular administration of histamine improves the aggravation, whereas blockade of histamine H2 receptors aggravates ischemic injury. Furthermore, H2 blockade enhances ischemic release of glutamate and dopamine. These findings suggest that central histamine provides beneficial effects against ischemic neuronal damage by suppressing release of excitatory neurotransmitters. However, histaminergic H2 action facilitates the permeability of the blood-brain barrier and shows deleterious effects on cerebral edema.

  13. Preservation of retinal structure and function after cilioretinal artery occlusion: a case report

    PubMed Central

    Brown, Craig J

    2016-01-01

    Cilioretinal artery occlusion is a cause of sudden, often catastrophic loss of central vision. There are no established effective treatments. Recently, a patient presented 24 hours after a cilioretinal artery occlusion, following a cardiac catheterization prior to which her blood thinners had been discontinued. Lacking an effective way to address the severe retinal ischemic oxidative stress, she was offered, under compassionate use, a multivitamin complex designed to address retinal ischemia and oxidative stress. Significant components of this product are L-methylfolate and n-acetyl cysteine. The patient experienced a rapid unexpected improvement in vision and preservation of retinal structure, suggesting that marked improvement in retinal artery occlusions outcomes may be possible as late as 24 hours postocclusion. This is the third reported case of cilioretinal artery occlusion associated with cardiac catheterization. PMID:26929671

  14. Progressive outer retinal necrosis-like retinitis in immunocompetent hosts.

    PubMed

    Chawla, Rohan; Tripathy, Koushik; Gogia, Varun; Venkatesh, Pradeep

    2016-08-10

    We describe two young immunocompetent women presenting with bilateral retinitis with outer retinal necrosis involving posterior pole with centrifugal spread and multifocal lesions simulating progressive outer retinal necrosis (PORN) like retinitis. Serology was negative for HIV and CD4 counts were normal; however, both women were on oral steroids at presentation for suspected autoimmune chorioretinitis. The retinitis in both eyes responded well to oral valaciclovir therapy. However, the eye with the more fulminant involvement developed retinal detachment with a loss of vision. Retinal atrophy was seen in the less involved eye with preservation of vision. Through these cases, we aim to describe a unique evolution of PORN-like retinitis in immunocompetent women, which was probably aggravated by a short-term immunosuppression secondary to oral steroids.

  15. Photovoltaic retinal prosthesis

    NASA Astrophysics Data System (ADS)

    Loudin, James; Mathieson, Keith; Kamins, Ted; Wang, Lele; Galambos, Ludwig; Huie, Philip; Sher, Alexander; Harris, James; Palanker, Daniel

    2011-03-01

    Electronic retinal prostheses seek to restore sight to patients suffering from retinal degenerative disorders. Implanted electrode arrays apply patterned electrical stimulation to surviving retinal neurons, producing visual sensations. All current designs employ inductively coupled coils to transmit power and/or data to the implant. We present here the design and initial testing of a photovoltaic retinal prosthesis fabricated with a pixel density of up to 177 pixels/mm2. Photodiodes within each pixel of the subretinal array directly convert light to stimulation current, avoiding the use of bulky coil implants, decoding electronics, and wiring, and thereby reducing surgical complexity. A goggles-mounted camera captures the visual scene and transmits the data stream to a pocket processor. The resulting images are projected into the eyes by video goggles using pulsed, near infrared (~900 nm) light. Prostheses with three pixel densities (15, 55, and 177 pix/mm2) are being fabricated, and tests indicate a charge injection limit of 1.62 mC/cm2 at 25Hz. In vitro tests of the photovoltaic retinal stimulation using a 512-element microelectrode array have recorded stimulated spikes from the ganglion cells, with latencies in the 1-100ms range, and with peak irradiance stimulation thresholds varying from 0.1 to 1 mW/mm2. With 1ms pulses at 25Hz the average irradiance is more than 100 times below the IR retinal safety limit. Elicited retinal response disappeared upon the addition of synaptic blockers, indicating that the inner retina is stimulated rather than the ganglion cells directly, and raising hopes that the prosthesis will preserve some of the retina's natural signal processing.

  16. Quantitative analysis of retinal OCT.

    PubMed

    Sonka, Milan; Abràmoff, Michael D

    2016-10-01

    Clinical acceptance of 3-D OCT retinal imaging brought rapid development of quantitative 3-D analysis of retinal layers, vasculature, retinal lesions as well as facilitated new research in retinal diseases. One of the cornerstones of many such analyses is segmentation and thickness quantification of retinal layers and the choroid, with an inherently 3-D simultaneous multi-layer LOGISMOS (Layered Optimal Graph Image Segmentation for Multiple Objects and Surfaces) segmentation approach being extremely well suited for the task. Once retinal layers are segmented, regional thickness, brightness, or texture-based indices of individual layers can be easily determined and thus contribute to our understanding of retinal or optic nerve head (ONH) disease processes and can be employed for determination of disease status, treatment responses, visual function, etc. Out of many applications, examples provided in this paper focus on image-guided therapy and outcome prediction in age-related macular degeneration and on assessing visual function from retinal layer structure in glaucoma.

  17. Association between Anger and Mental Stress-Induced Myocardial Ischemia

    PubMed Central

    Pimple, Pratik; Shah, Amit; Rooks, Cherie; Bremner, J. Douglas; Nye, Jonathon; Ibeanu, Ijeoma; Murrah, Nancy; Shallenberger, Lucy; Kelley, Mary; Raggi, Paolo; Vaccarino, Viola

    2014-01-01

    Background Mental stress-induced myocardial ischemia is associated with adverse prognosis in coronary artery disease patients. Anger is thought to be a trigger of acute coronary syndromes and is associated with increased cardiovascular risk; however, little direct evidence exists for a link between anger and myocardial ischemia. Methods [99mTc]sestamibi single-photon emission tomography was performed at rest, after mental stress (a social stressor with a speech task), and after exercise/pharmacological stress. Summed scores of perfusion abnormalities were obtained by observer-independent software. A summed difference score, the difference between stress and rest scores, was used to quantify myocardial ischemia under both stress conditions. The Spielberger's State-Trait Anger Expression Inventory was used to assess different anger dimensions. Results The mean age was 50 years, 50% were female and 60% were non-white. After adjusting for demographic factors, smoking, coronary artery disease severity, depressive and anxiety symptoms, each interquartile range increment in state-anger score was associated with 0.36 units adjusted increase in ischemia as measured by the summed difference score (95% CI: 0.14-0.59); the corresponding association for trait-anger was 0.95 (95% CI: 0.21-1.69). Anger expression scales were not associated ischemia. None of the anger dimensions were related to ischemia during exercise/pharmacological stress. Conclusion Anger, both as an emotional state and as a personality trait, is significantly associated with propensity to develop myocardial ischemia during mental stress, but not during exercise/pharmacological stress. Patients with this psychological profile may be at increased risk for silent ischemia induced by emotional stress and this may translate into worse prognosis. PMID:25497256

  18. Electronic retinal implant surgery.

    PubMed

    MacLaren, R E

    2017-02-01

    Blindness due to outer retinal degeneration still remains largely untreatable. Photoreceptor loss removes light sensitivity, but the remaining inner retinal layers, the optic nerve, and indeed the physical structure of the eye itself may be unaffected by the degenerative processes. This provides the opportunity to restore some degree of vision with an electronic device in the subretinal space. In this lecture I will provide an overview of our experiences with the first-generation retinal implant Alpha IMS, developed by Retina Implant AG and based on the technology developed by Eberhart Zrenner as part of a multicentre clinical trial (NCT01024803). We are currently in the process of running a second NIHR-funded clinical trial to assess the next-generation device. The positive results from both studies to date indicate that the retinal implant should be included as a potential treatment for patients who are completely blind from retinitis pigmentosa. Evolution of the technology in future may provide further opportunities for earlier intervention or for other diseases.

  19. Hyperspectral retinal imaging with a spectrally tunable light source

    NASA Astrophysics Data System (ADS)

    Francis, Robert P.; Zuzak, Karel J.; Ufret-Vincenty, Rafael

    2011-03-01

    Hyperspectral retinal imaging can measure oxygenation and identify areas of ischemia in human patients, but the devices used by current researchers are inflexible in spatial and spectral resolution. We have developed a flexible research prototype consisting of a DLP®-based spectrally tunable light source coupled to a fundus camera to quickly explore the effects of spatial resolution, spectral resolution, and spectral range on hyperspectral imaging of the retina. The goal of this prototype is to (1) identify spectral and spatial regions of interest for early diagnosis of diseases such as glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy (DR); and (2) define required specifications for commercial products. In this paper, we describe the challenges and advantages of using a spectrally tunable light source for hyperspectral retinal imaging, present clinical results of initial imaging sessions, and describe how this research can be leveraged into specifying a commercial product.

  20. Embolization of Onyx Causing Acute Limb Ischemia.

    PubMed

    Lind, Benjamin B; Briggs, Charles S; Golan, John; Gupta, NavYash

    2017-01-01

    We present the case of a patient with a refractory type II endoleak treated with translumbar Onyx with passage of the Onyx material into the endograft and subsequent embolization to the infrainguinal vasculature. This report represents a new complication of Onyx embolization that, to our knowledge, has not previously been described in the literature.

  1. Automated detection of retinal whitening in malarial retinopathy

    NASA Astrophysics Data System (ADS)

    Joshi, V.; Agurto, C.; Barriga, S.; Nemeth, S.; Soliz, P.; MacCormick, I.; Taylor, T.; Lewallen, S.; Harding, S.

    2016-03-01

    Cerebral malaria (CM) is a severe neurological complication associated with malarial infection. Malaria affects approximately 200 million people worldwide, and claims 600,000 lives annually, 75% of whom are African children under five years of age. Because most of these mortalities are caused by the high incidence of CM misdiagnosis, there is a need for an accurate diagnostic to confirm the presence of CM. The retinal lesions associated with malarial retinopathy (MR) such as retinal whitening, vessel discoloration, and hemorrhages, are highly specific to CM, and their detection can improve the accuracy of CM diagnosis. This paper will focus on development of an automated method for the detection of retinal whitening which is a unique sign of MR that manifests due to retinal ischemia resulting from CM. We propose to detect the whitening region in retinal color images based on multiple color and textural features. First, we preprocess the image using color and textural features of the CMYK and CIE-XYZ color spaces to minimize camera reflex. Next, we utilize color features of the HSL, CMYK, and CIE-XYZ channels, along with the structural features of difference of Gaussians. A watershed segmentation algorithm is used to assign each image region a probability of being inside the whitening, based on extracted features. The algorithm was applied to a dataset of 54 images (40 with whitening and 14 controls) that resulted in an image-based (binary) classification with an AUC of 0.80. This provides 88% sensitivity at a specificity of 65%. For a clinical application that requires a high specificity setting, the algorithm can be tuned to a specificity of 89% at a sensitivity of 82%. This is the first published method for retinal whitening detection and combining it with the detection methods for vessel discoloration and hemorrhages can further improve the detection accuracy for malarial retinopathy.

  2. Probabilistic retinal vessel segmentation

    NASA Astrophysics Data System (ADS)

    Wu, Chang-Hua; Agam, Gady

    2007-03-01

    Optic fundus assessment is widely used for diagnosing vascular and non-vascular pathology. Inspection of the retinal vasculature may reveal hypertension, diabetes, arteriosclerosis, cardiovascular disease and stroke. Due to various imaging conditions retinal images may be degraded. Consequently, the enhancement of such images and vessels in them is an important task with direct clinical applications. We propose a novel technique for vessel enhancement in retinal images that is capable of enhancing vessel junctions in addition to linear vessel segments. This is an extension of vessel filters we have previously developed for vessel enhancement in thoracic CT scans. The proposed approach is based on probabilistic models which can discern vessels and junctions. Evaluation shows the proposed filter is better than several known techniques and is comparable to the state of the art when evaluated on a standard dataset. A ridge-based vessel tracking process is applied on the enhanced image to demonstrate the effectiveness of the enhancement filter.

  3. Retinoids and Retinal Diseases

    PubMed Central

    Kiser, Philip D.; Palczewski, Krzysztof

    2016-01-01

    Recent progress in molecular understanding of the retinoid cycle in mammalian retina stems from painstaking biochemical reconstitution studies supported by natural or engineered animal models with known genetic lesions and studies of humans with specific genetic blinding diseases. Structural and membrane biology have been used to detect critical retinal enzymes and proteins and their substrates and ligands, placing them in a cellular context. These studies have been supplemented by analytical chemistry methods that have identified small molecules by their spectral characteristics, often in conjunction with the evaluation of models of animal retinal disease. It is from this background that rational therapeutic interventions to correct genetic defects or environmental insults are identified. Thus, most presently accepted modulators of the retinoid cycle already have demonstrated promising results in animal models of retinal degeneration. These encouraging signs indicate that some human blinding diseases can be alleviated by pharmacological interventions. PMID:27917399

  4. Bioelectronic retinal prosthesis

    NASA Astrophysics Data System (ADS)

    Weiland, James D.

    2016-05-01

    Retinal prosthesis have been translated to clinical use over the past two decades. Currently, two devices have regulatory approval for the treatment of retinitis pigmentosa and one device is in clinical trials for treatment of age-related macular degeneration. These devices provide partial sight restoration and patients use this improved vision in their everyday lives to navigate and to detect large objects. However, significant vision restoration will require both better technology and improved understanding of the interaction between electrical stimulation and the retina. In particular, current retinal prostheses do not provide peripheral visions due to technical and surgical limitations, thus limiting the effectiveness of the treatment. This paper reviews recent results from human implant patients and presents technical approaches for peripheral vision.

  5. Automatic Retinal Oximetry

    NASA Astrophysics Data System (ADS)

    Halldorsson, G. H.; Karlsson, R. A.; Hardarson, S. H.; Mura, M. Dalla; Eysteinsson, T.; Beach, J. M.; Stefansson, E.; Benediktsson, J. A.

    2007-10-01

    This paper presents a method for automating the evaluation of hemoglobin oxygen saturation in the retina. This method should prove useful for monitoring ischemic retinal diseases and the effect of treatment. In order to obtain saturation values automatically, spectral images must be registered in pairs, the vessels of the retina located and measurement points must be selected. The registration algorithm is based on a data driven approach that circumvents many of the problems that have plagued previous methods. The vessels are extracted using an algorithm based on morphological profiles and supervised classifiers. Measurement points on retinal arterioles and venules as well as reference points on the adjacent fundus are automatically selected. Oxygen saturation values along vessels are averaged to arrive at a more accurate estimate of the retinal vessel oxygen saturation. The system yields reproducible results as well as being sensitive to changes in oxygen saturation.

  6. Retinal Failure in Diabetes: a Feature of Retinal Sensory Neuropathy.

    PubMed

    Gray, Ellyn J; Gardner, Thomas W

    2015-12-01

    Physiologic adaptations mediate normal responses to short-term and long-term stresses to ensure organ function. Organ failure results if adaptive responses fail to resolve persistent stresses or maladaptive reactions develop. The retinal neurovascular unit likewise undergoes adaptive responses to diabetes resulting in a retinal sensory neuropathy analogous to other sensory neuropathies. Vision-threatening diabetic retinal neuropathy results from unremitting metabolic and inflammatory stresses, leading to macular edema and proliferative diabetic retinopathy, states of "retinal failure." Current regulatory strategies focus primarily on the retinal failure stages, but new diagnostic modalities and understanding of the pathophysiology of diabetic retinopathy may facilitate earlier treatment to maintain vision in persons with diabetes.

  7. Pathway to Retinal Oximetry

    PubMed Central

    Beach, James

    2014-01-01

    Events and discoveries in oxygen monitoring over the past two centuries are presented as the background from which oximetry of the human retina evolved. Achievements and the people behind them are discussed, showing parallels between the work in tissue measurements and later in the eye. Developments in the two-wavelength technique for oxygen saturation measurements in retinal vessels are shown to exploit the forms of imaging technology available over time. The last section provides a short summary of the recent research in retinal diseases using vessel oximetry. PMID:25237591

  8. Hereditary Retinal Dystrophy.

    PubMed

    Hohman, Thomas C

    2016-12-30

    As our understanding of the genetic basis for inherited retinal disease has expanded, gene therapy has advanced into clinical development. When the gene mutations associated with inherited retinal dystrophies were identified, it became possible to create animal models in which individual gene were altered to match the human mutations. The retina of these animals were then characterized to assess whether the mutated genes produced retinal phenotypes characteristic of disease-affected patients. Following the identification of a subpopulation of patients with the affected gene and the development of techniques for the viral gene transduction of retinal cells, it has become possible to deliver a copy of the normal gene into the retinal sites of the mutated genes. When this was performed in animal models of monogenic diseases, at an early stage of retinal degeneration when the affected cells remained viable, successful gene augmentation corrected the structural and functional lesions characteristic of the specific diseases in the areas of the retina that were successfully transduced. These studies provided the essential proof-of-concept needed to advance monogenic gene therapies into clinic development; these therapies include treatments for: Leber's congenital amaurosis type 2, caused by mutations to RPE65, retinoid isomerohydrolase; choroideremia, caused by mutations to REP1, Rab escort protein 1; autosomal recessive Stargardt disease, caused by mutations to ABCA4, the photoreceptor-specific ATP-binding transporter; Usher 1B disease caused by mutations to MYO7A, myosin heavy chain 7; X-linked juvenile retinoschisis caused by mutations to RS1, retinoschisin; autosomal recessive retinitis pigmentosa caused by mutations to MERTK, the proto-oncogene tyrosine-protein kinase MER; Leber's hereditary optic neuropathy caused by mutations to ND4, mitochondrial nicotinamide adenine dinucleotide ubiquinone oxidoreductase (complex I) subunit 4 and achromatopsia, caused by

  9. Pathway to Retinal Oximetry.

    PubMed

    Beach, James

    2014-09-01

    Events and discoveries in oxygen monitoring over the past two centuries are presented as the background from which oximetry of the human retina evolved. Achievements and the people behind them are discussed, showing parallels between the work in tissue measurements and later in the eye. Developments in the two-wavelength technique for oxygen saturation measurements in retinal vessels are shown to exploit the forms of imaging technology available over time. The last section provides a short summary of the recent research in retinal diseases using vessel oximetry.

  10. Cilio-retinal arterial circulation in central retinal vein occlusion.

    PubMed Central

    McLeod, D

    1975-01-01

    The hypothesis that an occlusion of the central retinal artery is an essential prerequisite for haemorrhage formation after central retinal vein obstruction has been investigated by examining the fundus changes in patients with a cilio-retinal arterial circulation; the findings are at variance with the 'combined occlusion hypothesis'. Comparisons were made between the pathological features in two retinal capillary beds with independent sources of arterial supply--namely, the central retinal and cilio-retinal arteries--but with an obstructed venous drainage channel common to both--namely, the central retinal vein. The importance of intraluminal pressure changes (as distinct from perfusion changes) in the causation of haemorrhages and oedema after venous occlusion is stressed, and the role of arterial disease in the pathogenesis of venous occlusions is distinguished from its role in determining the sequelae of such occlusions. Images PMID:1203235

  11. The evolving concept of physiological ischemia training vs. ischemia preconditioning.

    PubMed

    Ni, Jun; Lu, Hongjian; Lu, Xiao; Jiang, Minghui; Peng, Qingyun; Ren, Caili; Xiang, Jie; Mei, Chengyao; Li, Jianan

    2015-11-01

    Ischemic heart diseases are the leading cause of death with increasing numbers of patients worldwide. Despite advances in revascularization techniques, angiogenic therapies remain highly attractive. Physiological ischemia training, which is first proposed in our laboratory, refers to reversible ischemia training of normal skeletal muscles by using a tourniquet or isometric contraction to cause physiologic ischemia for about 4 weeks for the sake of triggering molecular and cellular mechanisms to promote angiogenesis and formation of collateral vessels and protect remote ischemia areas. Physiological ischemia training therapy augments angiogenesis in the ischemic myocardium by inducing differential expression of proteins involved in energy metabolism, cell migration, protein folding, and generation. It upregulates the expressions of vascular endothelial growth factor, and induces angiogenesis, protects the myocardium when infarction occurs by increasing circulating endothelial progenitor cells and enhancing their migration, which is in accordance with physical training in heart disease rehabilitation. These findings may lead to a new approach of therapeutic angiogenesis for patients with ischemic heart diseases. On the basis of the promising results in animal studies, studies were also conducted in patients with coronary artery disease without any adverse effect in vivo, indicating that physiological ischemia training therapy is a safe, effective and non-invasive angiogenic approach for cardiovascular rehabilitation. Preconditioning is considered to be the most protective intervention against myocardial ischemia-reperfusion injury to date. Physiological ischemia training is different from preconditioning. This review summarizes the preclinical and clinical data of physiological ischemia training and its difference from preconditioning.

  12. The Neuroprotective Effect of Kefir on Spinal Cord Ischemia/Reperfusion Injury in Rats

    PubMed Central

    Akman, Tarik; Yener, Ali Umit; Sehitoglu, Muserref Hilal; Yuksel, Yasemin; Cosar, Murat

    2015-01-01

    Objective The main causes of spinal cord ischemia are a variety of vascular pathologies causing acute arterial occlusions. We investigated neuroprotective effects of kefir on spinal cord ischemia injury in rats. Methods Rats were divided into three groups : 1) sham operated control rats; 2) spinal cord ischemia group fed on a standard diet without kefir pretreatment; and 3) spinal cord ischemia group fed on a standard diet plus kefir. Spinal cord ischemia was performed by the infrarenal aorta cross-clamping model. The spinal cord was removed after the procedure. The biochemical and histopathological changes were observed within the samples. Functional assessment was performed for neurological deficit scores. Results The kefir group was compared with the ischemia group, a significant decrease in malondialdehyde levels was observed (p<0.05). Catalase and superoxide dismutase levels of the kefir group were significantly higher than ischemia group (p<0.05). In histopathological samples, the kefir group is compared with ischemia group, there was a significant decrease in numbers of dead and degenerated neurons (p<0.05). In immunohistochemical staining, hipoxia-inducible factor-1α and caspase 3 immunopositive neurons were significantly decreased in kefir group compared with ischemia group (p<0.05). The neurological deficit scores of kefir group were significantly higher than ischemia group at 24 h (p<0.05). Conclusion Our study revealed that kefir pretreatment in spinal cord ischemia/reperfusion reduced oxidative stress and neuronal degeneration as a neuroprotective agent. Ultrastructural studies are required in order for kefir to be developed as a promising therapeutic agent to be utilized for human spinal cord ischemia in the future. PMID:26113960

  13. Retinal locus for scanning text.

    PubMed

    Timberlake, George T; Sharma, Manoj K; Grose, Susan A; Maino, Joseph H

    2006-01-01

    A method of mapping the retinal location of text during reading is described in which text position is plotted cumulatively on scanning laser ophthalmoscope retinal images. Retinal locations that contain text most often are the brightest in the cumulative plot, and locations that contain text least often are the darkest. In this way, the retinal area that most often contains text is determined. Text maps were plotted for eight control subjects without vision loss and eight subjects with central scotomas from macular degeneration. Control subjects' text maps showed that the fovea contained text most often. Text maps of five of the subjects with scotomas showed that they used the same peripheral retinal area to scan text and fixate. Text maps of the other three subjects with scotomas showed that they used separate areas to scan text and fixate. Retinal text maps may help evaluate rehabilitative strategies for training individuals with central scotomas to use a particular retinal area to scan text.

  14. Retinal Waves Modulate an Intraretinal Circuit of Intrinsically Photosensitive Retinal Ganglion Cells

    PubMed Central

    Arroyo, David A.; Kirkby, Lowry A.

    2016-01-01

    Before the maturation of rod and cone photoreceptors, the developing retina relies on light detection by intrinsically photosensitive retinal ganglion cells (ipRGCs) to drive early light-dependent behaviors. ipRGCs are output neurons of the retina; however, they also form functional microcircuits within the retina itself. Whether ipRGC microcircuits exist during development and whether they influence early light detection remain unknown. Here, we investigate the neural circuit that underlies the ipRGC-driven light response in developing mice. We use a combination of calcium imaging, tracer coupling, and electrophysiology experiments to show that ipRGCs form extensive gap junction networks that strongly contribute to the overall light response of the developing retina. Interestingly, we found that gap junction coupling was modulated by spontaneous retinal waves, such that acute blockade of waves dramatically increased the extent of coupling and hence increased the number of light-responsive neurons. Moreover, using an optical sensor, we found that this wave-dependent modulation of coupling is driven by dopamine that is phasically released by retinal waves. Our results demonstrate that ipRGCs form gap junction microcircuits during development that are modulated by retinal waves; these circuits determine the extent of the light response and thus potentially impact the processing of early visual information and light-dependent developmental functions. SIGNIFICANCE STATEMENT Light-dependent functions in early development are mediated by intrinsically photosensitive retinal ganglion cells (ipRGCs). Here we show that ipRGCs form an extensive gap junction network with other retinal neurons, including other ipRGCs, which shapes the retina's overall light response. Blocking cholinergic retinal waves, which are the primary source of neural activity before maturation of photoreceptors, increased the extent of ipRGC gap junction networks, thus increasing the number of light

  15. Non-occlusive mesenteric ischemia.

    PubMed

    Lock, G; Schölmerich, J

    1995-07-01

    Non-occlusive disease of the mesentery is still a rather underdiagnosed and underestimated condition. It is associated with circumstances that may compromise circulation or the intake of drugs that may lower mesenteric blood flow. Pathophysiologically, a "low flow syndrome" of mesenteric circulation is followed by vasoconstriction; a reperfusion injury may contribute to the ischemic injury. Histopathological changes vary between superficial localized lesions and transmural gangrene. Diagnosis within the initial 24 hours of the development of symptoms is crucial for prognosis but remains a difficult task. Clinical presentation, laboratory tests and ultrasound lack specificity; the role of duplex ultrasound, tonometry and reflectance spectophotometry is still under evaluation. Mesenteric angiography remains the only reliable diagnostic tool and should be applied early in all patients in whom acute mesenteric ischemia is a real possibility. Therapy is aimed at the rapid correction of predisposing and precipitating factors and an effective treatment of mesenteric vasoconstriction. Treatment of choice is a papaverine infusion into the superior mesenteric artery via an angiography catheter. Patients with peritoneal signs have to be treated surgically.

  16. [Neuroprotective mechanisms of cannabinoids in brain ischemia and neurodegenerative disorders].

    PubMed

    Osuna-Zazuetal, Marcela Amparo; Ponce-Gómez, Juan Antonio; Pérez-Neri, Iván

    2015-06-01

    One of the most important causes of morbidity and mortality is neurologic dysfunction; its high incidence has led to an intense research of the mechanisms that protect the central nervous system from hypoxia and ischemia. The mayor challenge is to block the biochemical events leading to neuronal death. This may be achieved by neuroprotective mechanisms that avoid the metabolic and immunologic cascades that follow a neurological damage. When it occurs, several pathophysiological events develop including cytokine release, oxidative stress and excitotoxicity. Neuroprotective effects of cannabinoids to all those mechanisms have been reported in animal models of brain ischemia, excitotoxicity, brain trauma and neurodegenerative disorders. Some endocannabinoid analogs are being tested in clinical studies (I-III phase) for acute disorders involving neuronal death (brain trauma and ischemia). The study of the cannabinoid system may allow the discovery of effective neuroprotective drugs for the treatment of neurological disorders.

  17. Nanomaterials and Retinal Toxicity

    EPA Science Inventory

    The neuroretina should be considered as a potential site of nanomaterial toxicity. Engineered nanomaterials may reach the retina through three potential routes of exposure including; intra­ vitreal injection of therapeutics; blood-borne delivery in the retinal vasculature an...

  18. Retinal Vasculitis in Anti-Synthetase Syndrome.

    PubMed

    Donovan, Christopher P; Pecen, Paula E; Baynes, Kimberly; Ehlers, Justis P; Srivastava, Sunil K

    2016-09-01

    A 31-year-old woman with a history of anti-synthetase syndrome-related myositis and interstitial lung disease presented with acute-onset blurry vision and rash on her hands and feet. Visual acuity was hand motion in her right eye and 20/40 in her left eye. Dilated fundus exam showed extensive retinal vasculitis, diffuse intraretinal hemorrhages, and subretinal fluid. Optical coherence tomography revealed significant macular thickening, and fluorescein angiography revealed vascular leakage with peripheral nonperfusion. Aggressive systemic immunosuppression was initiated, with gradual resolution of her disease during 8 months of follow-up. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:874-879.].

  19. Vascular Endothelial Growth Factor-A Is a Survival Factor for Retinal Neurons and a Critical Neuroprotectant during the Adaptive Response to Ischemic Injury

    PubMed Central

    Nishijima, Kazuaki; Ng, Yin-Shan; Zhong, Lichun; Bradley, John; Schubert, William; Jo, Nobuo; Akita, Jo; Samuelsson, Steven J.; Robinson, Gregory S.; Adamis, Anthony P.; Shima, David T.

    2007-01-01

    Vascular endothelial growth factor-A (VEGF-A) has recently been recognized as an important neuroprotectant in the central nervous system. Given its position as an anti-angiogenic target in the treatment of human diseases, understanding the extent of VEGF’s role in neural cell survival is paramount. Here, we used a model of ischemia-reperfusion injury and found that VEGF-A exposure resulted in a dose-dependent reduction in retinal neuron apoptosis. Although mechanistic studies suggested that VEGF-A-induced volumetric blood flow to the retina may be partially responsible for the neuroprotection, ex vivo retinal culture demonstrated a direct neuroprotective effect for VEGF-A. VEGF receptor-2 (VEGFR2) expression was detected in several neuronal cell layers of the retina, and functional analyses showed that VEGFR2 was involved in retinal neuroprotection. VEGF-A was also shown to be involved in the adaptive response to retinal ischemia. Ischemic preconditioning 24 hours before ischemia-reperfusion injury increased VEGF-A levels and substantially decreased the number of apoptotic retinal cells. The protective effect of ischemic preconditioning was reversed after VEGF-A inhibition. Finally, chronic inhibition of VEGF-A function in normal adult animals led to a significant loss of retinal ganglion cells yet had no observable effect on several vascular parameters. These findings have implications for both neural pathologies and ocular vascular diseases, such as diabetic retinopathy and age-related macular degeneration. PMID:17591953

  20. Gender-Dependent Effects of Enriched Environment and Social Isolation in Ischemic Retinal Lesion in Adult Rats

    PubMed Central

    Kiss, Peter; Szabadfi, Krisztina; Horvath, Gabor; Tamas, Andrea; Farkas, Jozsef; Gabriel, Robert; Reglodi, Dora

    2013-01-01

    Exposure to an enriched environment has been shown to have many positive effects on brain structure and function. Numerous studies have proven that enriched environment can reduce the lesion induced by toxic and traumatic injuries. Impoverished environment, on the other hand, can have deleterious effects on the outcome of neuronal injuries. We have previously shown that enriched conditions have protective effects in retinal injury in newborn rats. It is well-known that the efficacy of neuroprotective strategies can depend on age and gender. The aim of the present study, therefore, was to examine the effects of environmental enrichment and social isolation in retinal ischemia. We used bilateral common carotid artery occlusion to induce retinal hypoperfusion in adult Wistar rats of both genders. Groups were housed in standard, enriched or impoverished conditions. Impoverished environment was induced by social isolation. Retinas were processed for histological analysis after two weeks of survival. In the present study, we show that (1) enriched environment has protective effects in adult ischemic retinal lesion, while (2) impoverished environment further increases the degree of ischemic injury, and (3) that these environmental effects are gender-dependent: females are less responsive to the positive effects of environmental enrichment and more vulnerable to retinal ischemia in social isolation. In summary, our present study shows that the effects of both positive and negative environmental stimuli are gender-dependent in ischemic retinal lesions. PMID:23921682

  1. How much ischemia can the liver tolerate during resection?

    PubMed Central

    van Riel, Wouter G.; van Golen, Rowan F.; Reiniers, Megan J.; Heger, Michal

    2016-01-01

    The use of vascular inflow occlusion (VIO, also known as the Pringle maneuver) during liver surgery prevents severe blood loss and the need for blood transfusion. The most commonly used technique for VIO entails clamping of the portal triad, which simultaneously occludes the proper hepatic artery and portal vein. Although VIO is an effective technique to reduce intraoperative blood loss, it also inevitably inflicts hepatic ischemia/reperfusion (I/R) injury as a side effect. I/R injury induces formation of reactive oxygen species that cause oxidative stress and cell death, ultimately leading to a sterile inflammatory response that causes hepatocellular damage and liver dysfunction that can result in acute liver failure in most severe cases. Since the duration of ischemia correlates positively with the severity of liver injury, there is a need to find the balance between preventing severe blood loss and inducing liver damage through the use of VIO. Although research on the maximum duration of hepatic ischemia has intensified since the beginning of the 1980s, there still is no consensus on the tolerable upper limit. Based on the available literature, it is concluded that intermittent and continuous VIO can both be used safely when ischemia times do not exceed 120 min. However, intermittent VIO should be the preferred technique in cases that require >120 min duration of ischemia. PMID:26904558

  2. Tsc1 (hamartin) confers neuroprotection against ischemia by inducing autophagy

    PubMed Central

    Papadakis, Michalis; Hadley, Gina; Xilouri, Maria; Hoyte, Lisa C.; Nagel, Simon; McMenamin, M Mary; Tsaknakis, Grigorios; Watt, Suzanne M.; Drakesmith, Cynthia Wright; Chen, Ruoli; Wood, Matthew J A; Zhao, Zonghang; Kessler, Benedikt; Vekrellis, Kostas; Buchan, Alastair M.

    2013-01-01

    Previous attempts to identify neuroprotective targets by studying the ischemic cascade and devising ways to suppress it have failed to translate to efficacious therapies for acute ischemic stroke1. We hypothesized that studying the molecular determinants of endogenous neuroprotection in two well-established paradigms, the resistance of CA3 hippocampal neurons to global ischemia2 and the tolerance conferred by ischemic preconditioning (IPC)3, would reveal new neuroprotective targets. We found that the product of the tuberous sclerosis complex 1 gene (TSC1), hamartin, is selectively induced by ischemia in hippocampal CA3 neurons. In CA1 neurons, hamartin was unaffected by ischemia but was upregulated by IPC preceding ischemia, which protects the otherwise vulnerable CA1 cells. Suppression of hamartin expression with TSC1 shRNA viral vectors both in vitro and in vivo increased the vulnerability of neurons to cell death following oxygen glucose deprivation (OGD) and ischemia. In vivo suppression of TSC1 expression increased locomotor activity and decreased habituation in a hippocampal-dependent task. Overexpression of hamartin increased resistance to OGD by inducing productive autophagy through an mTORC1-dependent mechanism. PMID:23435171

  3. Tsc1 (hamartin) confers neuroprotection against ischemia by inducing autophagy.

    PubMed

    Papadakis, Michalis; Hadley, Gina; Xilouri, Maria; Hoyte, Lisa C; Nagel, Simon; McMenamin, M Mary; Tsaknakis, Grigorios; Watt, Suzanne M; Drakesmith, Cynthia Wright; Chen, Ruoli; Wood, Matthew J A; Zhao, Zonghang; Kessler, Benedikt; Vekrellis, Kostas; Buchan, Alastair M

    2013-03-01

    Previous attempts to identify neuroprotective targets by studying the ischemic cascade and devising ways to suppress it have failed to translate to efficacious therapies for acute ischemic stroke. We hypothesized that studying the molecular determinants of endogenous neuroprotection in two well-established paradigms, the resistance of CA3 hippocampal neurons to global ischemia and the tolerance conferred by ischemic preconditioning (IPC), would reveal new neuroprotective targets. We found that the product of the tuberous sclerosis complex 1 gene (TSC1), hamartin, is selectively induced by ischemia in hippocampal CA3 neurons. In CA1 neurons, hamartin was unaffected by ischemia but was upregulated by IPC preceding ischemia, which protects the otherwise vulnerable CA1 cells. Suppression of hamartin expression with TSC1 shRNA viral vectors both in vitro and in vivo increased the vulnerability of neurons to cell death following oxygen glucose deprivation (OGD) and ischemia. In vivo, suppression of TSC1 expression increased locomotor activity and decreased habituation in a hippocampal-dependent task. Overexpression of hamartin increased resistance to OGD by inducing productive autophagy through an mTORC1-dependent mechanism.

  4. Early retinal inflammatory biomarkers in the middle cerebral artery occlusion model of ischemic stroke

    PubMed Central

    Ritzel, Rodney M.; Pan, Sarah J.; Verma, Rajkumar; Wizeman, John; Crapser, Joshua; Patel, Anita R.; Lieberman, Richard; Mohan, Royce

    2016-01-01

    Purpose The transient middle cerebral artery occlusion (MCAO) model of stroke is one of the most commonly used models to study focal cerebral ischemia. This procedure also results in the simultaneous occlusion of the ophthalmic artery that supplies the retina. Retinal cell death is seen days after reperfusion and leads to functional deficits; however, the mechanism responsible for this injury has not been investigated. Given that the eye may have a unique ocular immune response to an ischemic challenge, this study examined the inflammatory response to retinal ischemia in the MCAO model. Methods Young male C57B/6 mice were subjected to 90-min transient MCAO and were euthanized at several time points up to 7 days. Transcription of inflammatory cytokines was measured with quantitative real-time PCR, and immune cell activation (e.g., phagocytosis) and migration were assessed with ophthalmoscopy and flow cytometry. Results Observation of the affected eye revealed symptoms consistent with Horner’s syndrome. Light ophthalmoscopy confirmed the reduced blood flow of the retinal arteries during occlusion. CX3CR1-GFP reporter mice were then employed to evaluate the extent of the ocular microglia and monocyte activation. A significant increase in green fluorescent protein (GFP)-positive macrophages was seen throughout the ischemic area compared to the sham and contralateral control eyes. RT–PCR revealed enhanced expression of the monocyte chemotactic molecule CCL2 early after reperfusion followed by a delayed increase in the proinflammatory cytokine TNF-α. Further analysis of peripheral leukocyte recruitment by flow cytometry determined that monocytes and neutrophils were the predominant immune cells to infiltrate at 72 h. A transient reduction in retinal microglia numbers was also observed, demonstrating the ischemic sensitivity of these cells. Blood–eye barrier permeability to small and large tracer molecules was increased by 72 h. Retinal microglia exhibited enhanced

  5. Structure and function of myelinated nerve fibers in the rabbit eye following ischemia/reperfusion injury.

    PubMed

    Guo, Wenyi; Cringle, Stephen J; Su, Er-Ning; Yu, Paula K; Yu, Xiao-Bo; Sun, Xinghuai; Morgan, William; Yu, Dao-Yi

    2006-02-01

    The rabbit eye presents a valuable model to study the effects of vascular occlusion on the function and structure of myelinated nerve fibers. The rabbit eye has a band of myelinated nerve fibers within the intraocular compartment that are supplied by a narrow band of retinal vasculature. These vessels were transiently occluded ( approximately 8 hours) using laser photocoagulation and the transmission of electrical signals along the nerve fibers was assessed by recording the visual evoked response (VER). Morphological damage was assessed by histological techniques. The ischemic insult produced no permanent change in retinal function as assessed by electroretinography, but the VER was suppressed, indicating failure of nerve fiber transmission. Histologically, the visible damage to the region supported by the retinal vasculature worsened following reperfusion, showing evidence of demyelination and necrosis followed by macrophage responses and gliosis. This rabbit model of ischemia/reperfusion of the retinal vasculature offers a rare opportunity to reliably study the response of myelinated nerve fibers to ischemia/reperfusion insults and has demonstrated the susceptibility of myelinated nerve fibers to such insults.

  6. [Effect of phenibut and its composition with nicotinic acid on hemostasis in rats with brain ischemia].

    PubMed

    Tiurenkov, I N; Volotova, E V; Kurkin, D V; Litvinov, A A; Tarasov, A S

    2012-01-01

    It is shown that, in rats with global cerebral ischemia modeled by a complete irreversible occlusion of the common carotid artery and forced hypotension, the hemostasis is characterized by a shift toward hypercoagulation. A single preventive introduction of phenibut and, to a greater degree, a composition of phenibut with nicotinic acid, in rats with acute cerebral ischemia reduced the extent of disturbances in the hemostasis system of experimental animals.

  7. Critical ischemia time in a model of spinal cord section. A study performed on dogs

    PubMed Central

    Garcia Martinez, David; Rosales Corral, Sergio A.; Flores Soto, Mario E.; Velarde Silva, Gustavo; Portilla de Buen, Eliseo

    2006-01-01

    Vascular changes after acute spinal cord trauma are important factors that predispose quadriplegia, in most cases irreversible. Repair of the spinal blood flow helps the spinal cord recovery. The average time to arrive and perform surgery is 3 h in most cases. It is important to determine the critical ischemia time in order to offer better functional prognosis. A spinal cord section and vascular clamping of the spinal anterior artery at C5–C6 model was used to determine critical ischemia time. The objective was to establish a critical ischemia time in a model of acute spinal cord section. Four groups of dogs were used, anterior approach and vascular clamp of spinal anterior artery with 1, 2, 3, and 4 h of ischemia and posterior hemisection of spinal cord at C5–C6 was performed. Clinical evaluation was made during 12 weeks and morphological evaluation at the end of this period. We obtained a maximal neurological coordination at 23 days average. Two cases showed sequels of right upper limb paresis at 1 and 3 ischemia hours. There was nerve conduction delay of 56% at 3 h of ischemia. Morphological examination showed 25% of damaged area. The VIII and IX Rexed’s laminae were the most affected. The critical ischemia time was 3 h. Dogs with 4 h did not exhibit any recovery. PMID:17024402

  8. Tyrosol attenuates ischemia-reperfusion-induced kidney injury via inhibition of inducible nitric oxide synthase.

    PubMed

    Wang, Pengqi; Zhu, Qingjun; Wu, Nan; Siow, Yaw L; Aukema, Harold; O, Karmin

    2013-04-17

    Tyrosol is a natural phenolic antioxidant compound. Oxidative stress represents one of the important mechanisms underlying ischemia-reperfusion-induced kidney injury. The aim of this study was to investigate the effect of tyrosol against ischemia-reperfusion-induced acute kidney injury. The left kidney of Sprague-Dawley rats was subjected to 45 min of ischemia followed by reperfusion for 6 h. Ischemia-reperfusion caused an increase in peroxynitrite formation and lipid peroxidation. The level of nitric oxide (NO) metabolites and the mRNA of inducible nitric oxide synthase (iNOS) were elevated in ischemia-reperfused kidneys. Administration of tyrosol (100 mg/kg body weight) to rats prior to the induction of ischemia significantly reduced peroxynitrite formation, lipid peroxidation, and the level of NO metabolites. Tyrosol administration also attenuated ischemia-reperfusion-induced NF-κB activation and iNOS expression. Such a treatment improved kidney function. Results suggest that tyrosol may have a protective effect against acute kidney injury through inhibition of iNOS-mediated oxidative stress.

  9. cGMP-Phosphodiesterase Inhibition Prevents Hypoxia-Induced Cell Death Activation in Porcine Retinal Explants.

    PubMed

    Olivares-González, Lorena; Martínez-Fernández de la Cámara, Cristina; Hervás, David; Marín, María Pilar; Lahoz, Agustin; Millán, José María; Rodrigo, Regina

    2016-01-01

    Retinal hypoxia and oxidative stress are involved in several retinal degenerations including diabetic retinopathy, glaucoma, central retinal artery occlusion, or retinopathy of prematurity. The second messenger cyclic guanosine monophosphate (cGMP) has been reported to be protective for neuronal cells under several pathological conditions including ischemia/hypoxia. The purpose of this study was to evaluate whether the accumulation of cGMP through the pharmacological inhibition of phosphodiesterase (PDE) with Zaprinast prevented retinal degeneration induced by mild hypoxia in cultures of porcine retina. Exposure to mild hypoxia (5% O2) for 24h reduced cGMP content and induced retinal degeneration by caspase dependent and independent (PARP activation) mechanisms. Hypoxia also produced a redox imbalance reducing antioxidant response (superoxide dismutase and catalase activities) and increasing superoxide free radical release. Zaprinast reduced mild hypoxia-induced cell death through inhibition of caspase-3 or PARP activation depending on the cell layer. PDE inhibition also ameliorated the effects of mild hypoxia on antioxidant response and the release of superoxide radical in the photoreceptor layer. The use of a PKG inhibitor, KT5823, suggested that cGMP-PKG pathway is involved in cell survival and antioxidant response. The inhibition of PDE, therefore, could be useful for reducing retinal degeneration under hypoxic/ischemic conditions.

  10. cGMP-Phosphodiesterase Inhibition Prevents Hypoxia-Induced Cell Death Activation in Porcine Retinal Explants

    PubMed Central

    Olivares-González, Lorena; Martínez-Fernández de la Cámara, Cristina; Hervás, David; Marín, María Pilar; Lahoz, Agustin; Millán, José María

    2016-01-01

    Retinal hypoxia and oxidative stress are involved in several retinal degenerations including diabetic retinopathy, glaucoma, central retinal artery occlusion, or retinopathy of prematurity. The second messenger cyclic guanosine monophosphate (cGMP) has been reported to be protective for neuronal cells under several pathological conditions including ischemia/hypoxia. The purpose of this study was to evaluate whether the accumulation of cGMP through the pharmacological inhibition of phosphodiesterase (PDE) with Zaprinast prevented retinal degeneration induced by mild hypoxia in cultures of porcine retina. Exposure to mild hypoxia (5% O2) for 24h reduced cGMP content and induced retinal degeneration by caspase dependent and independent (PARP activation) mechanisms. Hypoxia also produced a redox imbalance reducing antioxidant response (superoxide dismutase and catalase activities) and increasing superoxide free radical release. Zaprinast reduced mild hypoxia-induced cell death through inhibition of caspase-3 or PARP activation depending on the cell layer. PDE inhibition also ameliorated the effects of mild hypoxia on antioxidant response and the release of superoxide radical in the photoreceptor layer. The use of a PKG inhibitor, KT5823, suggested that cGMP-PKG pathway is involved in cell survival and antioxidant response. The inhibition of PDE, therefore, could be useful for reducing retinal degeneration under hypoxic/ischemic conditions. PMID:27861632

  11. Calpain inhibitors reduce retinal hypoxia in ischemic retinopathy by improving neovascular architecture and functional perfusion.

    PubMed

    Hoang, Mien V; Smith, Lois E H; Senger, Donald R

    2011-04-01

    In ischemic retinopathies, underlying hypoxia drives abnormal neovascularization that damages retina and causes blindness. The abnormal neovasculature is tortuous and leaky and fails to alleviate hypoxia, resulting in more pathological neovascularization and retinal damage. With an established model of ischemic retinopathy we found that calpain inhibitors, when administered in moderation, reduced architectural abnormalities, reduced vascular leakage, and most importantly reduced retinal hypoxia. Mechanistically, these calpain inhibitors improved stability and organization of the actin cytoskeleton in retinal endothelial cells undergoing capillary morphogenesis in vitro, and they similarly improved organization of actin cables within new blood vessels in vivo. Hypoxia induced calpain activity in retinal endothelial cells and severely disrupted the actin cytoskeleton, whereas calpain inhibitors preserved actin cables under hypoxic conditions. Collectively, these findings support the hypothesis that hyper-activation of calpains by hypoxia contributes to disruption of the retinal endothelial cell cytoskeleton, resulting in formation of neovessels that are defective both architecturally and functionally. Modest suppression of calpain activity with calpain inhibitors restores cytoskeletal architecture and promotes formation of a functional neovasculature, thereby reducing underlying hypoxia. In sharp contrast to "anti-angiogenesis" strategies that cannot restore normoxia and may aggravate hypoxia, the therapeutic strategy described here does not inhibit neovascularization. Instead, by improving the function of neovascularization to reduce underlying hypoxia, moderate calpain inhibition offers a method for alleviating retinal ischemia, thereby suggesting a new treatment paradigm based on improvement rather than inhibition of new blood vessel growth.

  12. Ischemia causes muscle fatigue

    NASA Technical Reports Server (NTRS)

    Murthy, G.; Hargens, A. R.; Lehman, S.; Rempel, D. M.

    2001-01-01

    The purpose of this investigation was to determine whether ischemia, which reduces oxygenation in the extensor carpi radialis (ECR) muscle, causes a reduction in muscle force production. In eight subjects, muscle oxygenation (TO2) of the right ECR was measured noninvasively and continuously using near infrared spectroscopy (NIRS) while muscle twitch force was elicited by transcutaneous electrical stimulation (1 Hz, 0.1 ms). Baseline measurements of blood volume, muscle oxygenation and twitch force were recorded continuously, then a tourniquet on the upper arm was inflated to one of five different pressure levels: 20, 40, 60 mm Hg (randomized order) and diastolic (69 +/- 9.8 mm Hg) and systolic (106 +/- 12.8 mm Hg) blood pressures. Each pressure level was maintained for 3-5 min, and was followed by a recovery period sufficient to allow measurements to return to baseline. For each respective tourniquet pressure level, mean TO2 decreased from resting baseline (100% TO2) to 99 +/- 1.2% (SEM), 96 +/- 1.9%, 93 +/- 2.8%, 90 +/- 2.5%, and 86 +/- 2.7%, and mean twitch force decreased from resting baseline (100% force) to 99 +/- 0.7% (SEM), 96 +/- 2.7%, 93 +/- 3.1%, 88 +/- 3.2%, and 86 +/- 2.6%. Muscle oxygenation and twitch force at 60 mm Hg tourniquet compression and above were significantly lower (P < 0.05) than baseline value. Reduced twitch force was correlated in a dose-dependent manner with reduced muscle oxygenation (r = 0.78, P < 0.001). Although the correlation does not prove causation, the results indicate that ischemia leading to a 7% or greater reduction in muscle oxygenation causes decreased muscle force production in the forearm extensor muscle. Thus, ischemia associated with a modest decline in TO2 causes muscle fatigue.

  13. Sex steroids inhibit osmotic swelling of retinal glial cells.

    PubMed

    Neumann, Florian; Wurm, Antje; Linnertz, Regina; Pannicke, Thomas; Iandiev, Ianors; Wiedemann, Peter; Reichenbach, Andreas; Bringmann, Andreas

    2010-04-01

    Osmotic swelling of glial cells may contribute to the development of retinal edema. We investigated whether sex steroids inhibit the swelling of glial somata in acutely isolated retinal slices and glial cells of the rat. Superfusion of retinal slices or cells from control animals with a hypoosmolar solution did not induce glial swelling, whereas glial swelling was observed in slices of postischemic and diabetic retinas. Progesterone, testosterone, estriol, and 17beta-estradiol prevented glial swelling with half-maximal effects at approximately 0.3, 0.6, 6, and 20 microM, respectively. The effect of progesterone was apparently mediated by transactivation of metabotropic glutamate receptors, P2Y1, and adenosine A1 receptors. The data suggest that sex steroids may inhibit cytotoxic edema in the retina.

  14. Small Animal Retinal Imaging

    NASA Astrophysics Data System (ADS)

    Choi, WooJhon; Drexler, Wolfgang; Fujimoto, James G.

    Developing and validating new techniques and methods for small animal imaging is an important research area because there are many small animal models of retinal diseases such as diabetic retinopathy, age-related macular degeneration, and glaucoma [1-6]. Because the retina is a multilayered structure with distinct abnormalities occurring in different intraretinal layers at different stages of disease progression, there is a need for imaging techniques that enable visualization of these layers individually at different time points. Although postmortem histology and ultrastructural analysis can be performed for investigating microscopic changes in the retina in small animal models, this requires sacrificing animals, which makes repeated assessment of the same animal at different time points impossible and increases the number of animals required. Furthermore, some retinal processes such as neurovascular coupling cannot be fully characterized postmortem.

  15. Oligodendrogenesis after cerebral ischemia

    PubMed Central

    Zhang, Ruilan; Chopp, Michael; Zhang, Zheng Gang

    2013-01-01

    Neural stem cells in the subventricular zone (SVZ) of the lateral ventricle of adult rodent brain generate oligodendrocyte progenitor cells (OPCs) that disperse throughout the corpus callosum and striatum where some of OPCs differentiate into mature oligodendrocytes. Studies in animal models of stroke demonstrate that cerebral ischemia induces oligodendrogenesis during brain repair processes. This article will review evidence of stroke-induced proliferation and differentiation of OPCs that are either resident in white matter or are derived from SVZ neural progenitor cells and of therapies that amplify endogenous oligodendrogenesis in ischemic brain. PMID:24194700

  16. Massive Bilateral Serous Retinal Detachment in a Case of Hypertensive Chorioretinopathy

    PubMed Central

    Villalba-Pinto, Luis; Hernández-Ortega, M. Ángeles; de los Mozos, F. Javier Lavid; Pascual-Camps, Isabel; Dolz-Marco, Rosa; Arevalo, J. Fernando; Gallego-Pinazo, Roberto

    2014-01-01

    Introduction Systemic high blood pressure is related to a variety of retinal manifestations. We present an atypical case of hypertensive chorioretinopathy with massive bilateral serous retinal detachment. Case Report A 26-year-old male with a genitourinary malformation and secondary grade IV chronic kidney failure as well as high blood pressure complained of acute vision loss. Dilated fundus examination evidenced a bilateral serous retinal detachment with macular involvement. The patient was unresponsive to oral antihypertensive therapy and dialysis treatment. The serous retinal detachment progressively decreased after the restoration of dialysis and antihypertensive therapy. The final visual acuity was 0.50 in both eyes. Discussion In cases of serous macular detachment, it is mandatory to rule out different systemic and ocular diseases. The presence of uncontrolled high blood pressure may produce aggressive bilateral retinal changes, thus hypertension must be under early and strict control in order to improve the visual outcomes. PMID:25120474

  17. Inherited Retinal Degenerative Disease Registry

    ClinicalTrials.gov

    2016-03-21

    Eye Diseases Hereditary; Retinal Disease; Achromatopsia; Bardet-Biedl Syndrome; Bassen-Kornzweig Syndrome; Batten Disease; Best Disease; Choroidal Dystrophy; Choroideremia; Cone Dystrophy; Cone-Rod Dystrophy; Congenital Stationary Night Blindness; Enhanced S-Cone Syndrome; Fundus Albipunctatus; Goldmann-Favre Syndrome; Gyrate Atrophy; Juvenile Macular Degeneration; Kearns-Sayre Syndrome; Leber Congenital Amaurosis; Refsum Syndrome; Retinitis Pigmentosa; Retinitis Punctata Albescens; Retinoschisis; Rod-Cone Dystrophy; Rod Dystrophy; Rod Monochromacy; Stargardt Disease; Usher Syndrome

  18. Glutamatergic Retinal Waves

    PubMed Central

    Kerschensteiner, Daniel

    2016-01-01

    Spontaneous activity patterns propagate through many parts of the developing nervous system and shape the wiring of emerging circuits. Prior to vision, waves of activity originating in the retina propagate through the lateral geniculate nucleus (LGN) of the thalamus to primary visual cortex (V1). Retinal waves have been shown to instruct the wiring of ganglion cell axons in LGN and of thalamocortical axons in V1 via correlation-based plasticity rules. Across species, retinal waves mature in three stereotypic stages (I–III), in which distinct circuit mechanisms give rise to unique activity patterns that serve specific functions in visual system refinement. Here, I review insights into the patterns, mechanisms, and functions of stage III retinal waves, which rely on glutamatergic signaling. As glutamatergic waves spread across the retina, neighboring ganglion cells with opposite light responses (ON vs. OFF) are activated sequentially. Recent studies identified lateral excitatory networks in the inner retina that generate and propagate glutamatergic waves, and vertical inhibitory networks that desynchronize the activity of ON and OFF cells in the wavefront. Stage III wave activity patterns may help segregate axons of ON and OFF ganglion cells in the LGN, and could contribute to the emergence of orientation selectivity in V1. PMID:27242446

  19. Lithium promotes DNA stability and survival of ischemic retinal neurocytes by upregulating DNA ligase IV

    PubMed Central

    Yang, Ying; Wu, Nandan; Tian, Sijia; Li, Fan; Hu, Huan; Chen, Pei; Cai, Xiaoxiao; Xu, Lijun; Zhang, Jing; Chen, Zhao; Ge, Jian; Yu, Keming; Zhuang, Jing

    2016-01-01

    Neurons display genomic fragility and show fragmented DNA in pathological degeneration. A failure to repair DNA breaks may result in cell death or apoptosis. Lithium protects retinal neurocytes following nutrient deprivation or partial nerve crush, but the underlying mechanisms are not well defined. Here we demonstrate that pretreatment with lithium protects retinal neurocytes from ischemia-induced damage and enhances light response in rat retina following ischemia–reperfusion injury. Moreover, we found that DNA nonhomologous end-joining (NHEJ) repair is implicated in this process because in ischemic retinal neurocytes, lithium significantly reduces the number of γ-H2AX foci (well-characterized markers of DNA double-strand breaks in situ) and increases the DNA ligase IV expression level. Furthermore, we also demonstrate that nuclear respiratory factor 1 (Nrf-1) and phosphorylated cyclic AMP-response element binding protein-1 (P-CREB1) bind to ligase IV promoter to cause upregulation of ligase IV in neurocytes. The ischemic upregulation of Nrf-1 and lithium-induced increase of P-CREB1 cooperate to promote transcription of ligase IV. Short hairpin RNAs against Nrf-1 and CREB1 could significantly inhibit the increase in promoter activity and expression of ligase IV observed in the control oligos following lithium treatment in retinal neurocytes. More importantly, ischemic stimulation triggers the expression of ligase IV. Taken together, our results thus reveal a novel mechanism that lithium offers neuroprotection from ischemia-induced damage by enhancing DNA NHEJ repair. PMID:27853172

  20. The role of Toll-like receptors in retinal ischemic diseases

    PubMed Central

    Xu, Wen-Qin; Wang, Yu-Sheng

    2016-01-01

    Toll-like receptors (TLRs) are commonly referred to a series of evolutionary conserved receptors which recognize and respond to various microbes and endogenous ligands. Growing evidence has demonstrated that the expression of TLRs in the retina is regulated during retinal ischemic diseases, including ischemia-reperfusion injury, glaucoma, diabetic retinopathy (DR) and retinopathy of prematurity (ROP). TLRs can be expressed in multiple cells in the retina, such as glial cells, retinal pigment epithelium (RPE), as well as photoreceptor cells and endothelium cells. Activation of TLRs in retina could initiate a complex signal transduction cascade, induce the production of inflammatory cytokines and regulate the level of co-stimulatory molecules, which play prominent roles in the pathogenesis of retinal ischemic diseases. In this review, we summarized current studies about the relationship between TLRs and ischemic retinopathy. A greater understanding of the effect of TLRs on ischemic injuries may contribute to the development of specific TLR targeted therapeutic strategies in these conditions. PMID:27672603

  1. The role of Toll-like receptors in retinal ischemic diseases.

    PubMed

    Xu, Wen-Qin; Wang, Yu-Sheng

    2016-01-01

    Toll-like receptors (TLRs) are commonly referred to a series of evolutionary conserved receptors which recognize and respond to various microbes and endogenous ligands. Growing evidence has demonstrated that the expression of TLRs in the retina is regulated during retinal ischemic diseases, including ischemia-reperfusion injury, glaucoma, diabetic retinopathy (DR) and retinopathy of prematurity (ROP). TLRs can be expressed in multiple cells in the retina, such as glial cells, retinal pigment epithelium (RPE), as well as photoreceptor cells and endothelium cells. Activation of TLRs in retina could initiate a complex signal transduction cascade, induce the production of inflammatory cytokines and regulate the level of co-stimulatory molecules, which play prominent roles in the pathogenesis of retinal ischemic diseases. In this review, we summarized current studies about the relationship between TLRs and ischemic retinopathy. A greater understanding of the effect of TLRs on ischemic injuries may contribute to the development of specific TLR targeted therapeutic strategies in these conditions.

  2. In vivo dynamics of retinal injury and repair in the rhodopsin mutant dog model of human retinitis pigmentosa.

    PubMed

    Cideciyan, Artur V; Jacobson, Samuel G; Aleman, Tomas S; Gu, Danian; Pearce-Kelling, Susan E; Sumaroka, Alexander; Acland, Gregory M; Aguirre, Gustavo D

    2005-04-05

    Genetic and environmental factors modify the severity of human neurodegenerations. Retinal degenerations caused by rhodopsin gene mutations show severity differences within and between families and even within regions of the same eye. Environmental light is thought to contribute to this variation. In the naturally occurring dog model of the human disorder, we found that modest light levels, as used in routine clinical practice, dramatically accelerated the neurodegeneration. Dynamics of acute retinal injury (consisting of abnormal intraretinal light scattering) were visualized in vivo in real time with high-resolution optical imaging. Long term consequences included fast or slow retinal degeneration or repair of injury depending on the dose of light exposure. These experiments provide a platform to study mechanisms of neuronal injury, repair, compensation, and degeneration. The data also argue for a gene-specific clinical trial of light reduction in human rhodopsin disease.

  3. In vivo dynamics of retinal injury and repair in the rhodopsin mutant dog model of human retinitis pigmentosa

    PubMed Central

    Cideciyan, Artur V.; Jacobson, Samuel G.; Aleman, Tomas S.; Gu, Danian; Pearce-Kelling, Susan E.; Sumaroka, Alexander; Acland, Gregory M.; Aguirre, Gustavo D.

    2005-01-01

    Genetic and environmental factors modify the severity of human neurodegenerations. Retinal degenerations caused by rhodopsin gene mutations show severity differences within and between families and even within regions of the same eye. Environmental light is thought to contribute to this variation. In the naturally occurring dog model of the human disorder, we found that modest light levels, as used in routine clinical practice, dramatically accelerated the neurodegeneration. Dynamics of acute retinal injury (consisting of abnormal intraretinal light scattering) were visualized in vivo in real time with high-resolution optical imaging. Long term consequences included fast or slow retinal degeneration or repair of injury depending on the dose of light exposure. These experiments provide a platform to study mechanisms of neuronal injury, repair, compensation, and degeneration. The data also argue for a gene-specific clinical trial of light reduction in human rhodopsin disease. PMID:15784735

  4. Intraocular retinal prosthesis.

    PubMed Central

    Humayun, M S

    2001-01-01

    PURPOSE: An electronic implant that can bypass the damaged photoreceptors and electrically stimulate the remaining retinal neurons to restore useful vision has been proposed. A number of key questions remain to make this approach feasible. The goal of this thesis is to address the following 2 specific null hypotheses: (1) Stimulus parameters make no difference in the electrically elicited retinal responses. (2) Just as we have millions of photoreceptors, so it will take a device that can generate millions of pixels/light points to create useful vision. METHODS: For electrophysiologic experiments, 2 different setups were used. In the first setup, charge-balanced pulses were delivered to the retinal surface via electrodes inserted through an open sky approach in normal or blind retinal degenerate (rd) mice. In the second setup, the rabbit retina was removed under red light conditions from an enucleated eye and then maintained in a chamber while being superfused with oxygenated, heated Ames media. In both setups, stimulating electrodes and recording electrodes were positioned on the retinal surface to evaluate the effect of varying stimulation parameters on the orthodromic retinal responses (i.e., recording electrode placed between stimulating electrodes and optic nerve head). For psychophysical experiments, visual images were divided into pixels of light that could be projected in a pattern on the retina in up to 8 sighted volunteers. Subjects were asked to perform various tasks ranging from reading and face recognition to various activities of daily living. RESULTS: Electrophysiologic experiments: In a normal mouse, a single cycle of a 1-kHz sine wave was significantly more efficient than a 1-kHz square wave (P < .05), but no such difference was noted in either of the 8- or 16-week-old rd mouse groups (8-week-old, P = .426; 16-week-old, P = .078). Charge threshold was significantly higher in 16-week-old rd mouse versus both 8-week-old rd and normal mouse for every

  5. Genomic Loci Modulating the Retinal Transcriptome in Wound Healing

    PubMed Central

    Vázquez-Chona, Félix R.; Lu, Lu; Williams, Robert W.; Geisert, Eldon E.

    2007-01-01

    Purpose The present study predicts and tests genetic networks that modulate gene expression during the retinal wound-healing response. Methods Upstream modulators and target genes were defined using meta-analysis and bioinformatic approaches. Quantitative trait loci (QTLs) for retinal acute phase genes (Vazquez-Chona et al. 2005) were defined using QTL analysis of CNS gene expression (Chesler et al. 2005). Candidate modulators were defined using computational analysis of gene and motif sequences. The effect of candidate genes on wound healing was tested using animal models of gene expression. Results A network of early wound-healing genes is modulated by a locus on chromosome 12. The genetic background of the locus altered the wound-healing response of the retina. The C57BL/6 allele conferred enhanced expression of neuronal marker Thy1 and heat-shock-like crystallins, whereas the DBA/2J allele correlated with greater levels of the classic marker of retinal stress, glial fibrillary acidic protein (GFAP). Id2 and Lpin1 are candidate upstream modulators as they strongly correlated with the segregation of DBA/2J and C57BL/6 alleles, and their dosage levels correlated with the enhanced expression of survival genes (Thy1 and crystallin genes). Conclusion We defined a genetic network associated with the retinal acute injury response. Using genetic linkage analysis of natural transcript variation, we identified regulatory loci and can didate modulators that control transcript levels of acute phase genes. Our results support the convergence of gene expression profiling, QTL analysis, and bioinformatics as a rational approach to discover molecular pathways controlling retinal wound healing. PMID:19936100

  6. Myocardial ischemia is a key factor in the management of stable coronary artery disease

    PubMed Central

    Iwasaki, Kohichiro

    2014-01-01

    Previous studies demonstrated that coronary revascularization, especially percutaneous coronary intervention (PCI), does not significantly decrease the incidence of cardiac death or myocardial infarction in patients with stable coronary artery disease. Many studies using myocardial perfusion imaging (MPI) showed that, for patients with moderate to severe ischemia, revascularization is the preferred therapy for survival benefit, whereas for patients with no to mild ischemia, medical therapy is the main choice, and revascularization is associated with increased mortality. There is some evidence that revascularization in patients with no or mild ischemia is likely to result in worsened ischemia, which is associated with increased mortality. Studies using fractional flow reserve (FFR) demonstrate that ischemia-guided PCI is superior to angiography-guided PCI, and the presence of ischemia is the key to decision-making for PCI. Complementary use of noninvasive MPI and invasive FFR would be important to compensate for each method’s limitations. Recent studies of appropriateness criteria showed that, although PCI in the acute setting and coronary bypass surgery are properly performed in most patients, PCI in the non-acute setting is often inappropriate, and stress testing to identify myocardial ischemia is performed in less than half of patients. Also, some studies suggested that revascularization in an inappropriate setting is not associated with improved prognosis. Taken together, the presence and the extent of myocardial ischemia is a key factor in the management of patients with stable coronary artery disease, and coronary revascularization in the absence of myocardial ischemia is associated with worsened prognosis. PMID:24772253

  7. Neuroprotective Antioxidant STAZN Protects Against Myocardial Ischemia/Reperfusion Injury

    PubMed Central

    Ley, James J.; Prado, Ricardo; Wei, Jian Qin; Bishopric, Nanette H.; Becker, David A.; Ginsberg, Myron D.

    2009-01-01

    Background Protecting the myocardium from ischemia-reperfusion injury has significant potential to reduce the complications of myocardial infarction and interventional revascularization procedures. Reperfusion damage is thought to result, in part, from oxidative stress. Here we use a novel method of percutaneous coronary occlusion to show that the potent antioxidant and neuroprotective free-radical scavenger, stilbazulenyl nitrone (STAZN), confers marked cardioprotection when given immediately prior to reperfusion. Methods and Results Physiologically controlled male Sprague-Dawley rats were anesthetized with isoflurane, paralyzed with pancuronium and mechanically ventilated. A guide wire was introduced via the femoral artery and advanced retrogradely via the aorta into the left coronary artery under fluoroscopic guidance. Rats with established coronary ischemia (85 min after occlusion) were given STAZN 3.5 mg/kg or its vehicle 5 minutes before and 2 hours after reperfusion, and were subjected to functional and histopathologic studies at 3 days. Ischemia-associated Q wave amplitude was reduced by 73% in STAZN-treated rats (P=0.01), while infarct-related ejection fraction, fractional shortening and severe regional wall-motion impairments were reduced by 48%, 54% and 37%, respectively, relative to vehicle-treated controls (P=0.05). Total myocardial infarct volume in STAZN-treated rats was correspondingly reduced by 43% (P<0.05), representing a sparing of 14% of the total left ventricular myocardium. Conclusions STAZN, a second-generation azulenyl nitrone with potent neuroprotective efficacy in brain ischemia, is also a rapidly acting and highly effective cardioprotective agent in acute coronary ischemia. Our results suggest the potential for clinical benefit in the setting of acute coronary syndromes. PMID:17936251

  8. Current and emerging treatment options for spinal cord ischemia.

    PubMed

    Nardone, Raffaele; Pikija, Slaven; Mutzenbach, J Sebastian; Seidl, Martin; Leis, Stefan; Trinka, Eugen; Sellner, Johann

    2016-10-01

    Spinal cord infarction (SCI) is a rare but disabling disorder caused by a wide spectrum of conditions. Given the lack of randomized-controlled trials, contemporary treatment concepts are adapted from guidelines for cerebral ischemia, atherosclerotic vascular disease, and acute traumatic spinal cord injury. In addition, patients with SCI are at risk for several potentially life-threatening but preventable systemic and neurologic complications. Notably, there is emerging evidence from preclinical studies for the use of neuroprotection in acute ischemic injury of the spinal cord. In this review, we discuss the current state of the art for the therapy and prevention of SCI and highlight potential emerging treatment concepts awaiting translational adoption.

  9. High resolution optoelectronic retinal prosthesis

    NASA Astrophysics Data System (ADS)

    Loudin, Jim; Dinyari, Rostam; Huie, Phil; Butterwick, Alex; Peumans, Peter; Palanker, Daniel

    2009-02-01

    Electronic retinal prostheses seek to restore sight in patients with retinal degeneration by delivering pulsed electric currents to retinal neurons via an array of microelectrodes. Most implants use inductive or optical transmission of information and power to an intraocular receiver, with decoded signals subsequently distributed to retinal electrodes through an intraocular cable. Surgical complexity could be minimized by an "integrated" prosthesis, in which both power and data are delivered directly to the stimulating array without any discrete components or cables. We present here an integrated retinal prosthesis system based on a photodiode array implant. Video frames are processed and imaged onto the retinal implant by a video goggle projection system operating at near-infrared wavelengths (~ 900 nm). Photodiodes convert light into pulsed electric current, with charge injection maximized by specially optimized series photodiode circuits. Prostheses of three different pixel densities (16 pix/mm2, 64 pix/mm2, and 256 pix/mm2) have been designed, simulated, and prototyped. Retinal tissue response to subretinal implants made of various materials has been investigated in RCS rats. The resulting prosthesis can provide sufficient charge injection for high resolution retinal stimulation without the need for implantation of any bulky discrete elements such as coils or tethers. In addition, since every pixel functions independently, pixel arrays may be placed separately in the subretinal space, providing visual stimulation to a larger field of view.

  10. Retinal Imaging and Image Analysis

    PubMed Central

    Abràmoff, Michael D.; Garvin, Mona K.; Sonka, Milan

    2011-01-01

    Many important eye diseases as well as systemic diseases manifest themselves in the retina. While a number of other anatomical structures contribute to the process of vision, this review focuses on retinal imaging and image analysis. Following a brief overview of the most prevalent causes of blindness in the industrialized world that includes age-related macular degeneration, diabetic retinopathy, and glaucoma, the review is devoted to retinal imaging and image analysis methods and their clinical implications. Methods for 2-D fundus imaging and techniques for 3-D optical coherence tomography (OCT) imaging are reviewed. Special attention is given to quantitative techniques for analysis of fundus photographs with a focus on clinically relevant assessment of retinal vasculature, identification of retinal lesions, assessment of optic nerve head (ONH) shape, building retinal atlases, and to automated methods for population screening for retinal diseases. A separate section is devoted to 3-D analysis of OCT images, describing methods for segmentation and analysis of retinal layers, retinal vasculature, and 2-D/3-D detection of symptomatic exudate-associated derangements, as well as to OCT-based analysis of ONH morphology and shape. Throughout the paper, aspects of image acquisition, image analysis, and clinical relevance are treated together considering their mutually interlinked relationships. PMID:21743764

  11. Will Retinal Implants Restore Vision?

    NASA Astrophysics Data System (ADS)

    Zrenner, Eberhart

    2002-02-01

    A number of research groups are developing electrical implants that can be attached directly to the retina in an attempt to restore vision to patients suffering from retinal degeneration. However, despite promising results in animal experiments, there are still several major obstacles to overcome before retinal prostheses can be used clinically.

  12. Low Level Laser Retinal Damage

    DTIC Science & Technology

    1990-03-01

    18 Related Projects ........................ . . ....... 20 References . . . . .......................... 22 2 INTRODUCTION The objectives of...fluorescein is a potent phototoxic agent in the retina.26 The damage threshold for blue light retinal damage is lowered by a factor of ten after an... Related to the Probiem of Retinal Light Damage 1. Corneal Holography 2. Hematoporphyrin Studies 3. Fluorescein Fluorescence Measurements 7 EQUIPMENT

  13. Perceptual Fading without Retinal Adaptation

    ERIC Educational Resources Information Center

    Hsieh, Po-Jang; Colas, Jaron T.

    2012-01-01

    A retinally stabilized object readily undergoes perceptual fading and disappears from consciousness. This startling phenomenon is commonly believed to arise from local bottom-up sensory adaptation to edge information that occurs early in the visual pathway, such as in the lateral geniculate nucleus of the thalamus or retinal ganglion cells. Here…

  14. Autophagy and Liver Ischemia-Reperfusion Injury

    PubMed Central

    2015-01-01

    Liver ischemia-reperfusion (I-R) injury occurs during liver resection, liver transplantation, and hemorrhagic shock. The main mode of liver cell death after warm and/or cold liver I-R is necrosis, but other modes of cell death, as apoptosis and autophagy, are also involved. Autophagy is an intracellular self-digesting pathway responsible for removal of long-lived proteins, damaged organelles, and malformed proteins during biosynthesis by lysosomes. Autophagy is found in normal and diseased liver. Although depending on the type of ischemia, warm and/or cold, the dynamic process of liver I-R results mainly in adenosine triphosphate depletion and in production of reactive oxygen species (ROS), leads to both, a local ischemic insult and an acute inflammatory-mediated reperfusion injury, and results finally in cell death. This process can induce liver dysfunction and can increase patient morbidity and mortality after liver surgery and hemorrhagic shock. Whether autophagy protects from or promotes liver injury following warm and/or cold I-R remains to be elucidated. The present review aims to summarize the current knowledge in liver I-R injury focusing on both the beneficial and the detrimental effects of liver autophagy following warm and/or cold liver I-R. PMID:25861623

  15. Relief of Mesenteric Ischemia by Z-Stent Placement into the Superior Mesenteric Artery Compressed by the False Lumen of an Aortic Dissection

    SciTech Connect

    Yamakado, Koichiro; Takeda, Kan; Nomura, Yoshiyuki; Kato, Noriyuki; Hirano, Tadanori; Matsumura, Kaname; Nakagawa, Tsuyoshi; Yuasa, Hiroshi; Yada, Isao

    1998-01-15

    In a 58-year-old man acute aortic dissection compromised the origin of the superior mesenteric artery (SMA), resulting in mesenteric ischemia. After failed balloon angioplasty a Gianturco Z-stent was placed. The stenosis improved immediately, followed by resolution of the clinical signs of mesenteric ischemia. SMA flow was well preserved 1 year after stenting.

  16. Nimesulide as a promising neuroprotectant in brain ischemia: new experimental evidences.

    PubMed

    Candelario-Jalil, Eduardo

    2008-04-01

    Nimesulide is a preferential inhibitor of cyclooxygenase-2 (COX-2) and it is one of the most prescribed non-steroidal anti-inflammatory drugs (NSAID) worldwide. Nimesulide was recently shown to have neuroprotective properties in animal models of acute neurologic injury. In particular, nimesulide is highly effective in reducing ischemic brain injury. This neuroprotective efficacy has been demonstrated in animal models of transient and permanent focal cerebral ischemia, global brain ischemia, embolic stroke, and chronic cerebral hypoperfusion. Nimesulide has been shown to reduce infarction, improve neurological function, attenuate blood-brain barrier disruption and edema, and reduce leukocyte infiltration into the ischemic brain. These beneficial effects have been observed even when the first treatment is given several hours after the onset of ischemia, demonstrating the wide therapeutic time window for nimesulide's neuroprotection. This is of great relevance since most stroke patients reach the emergency room several hours after the onset of symptoms, a time at which most medical interventions are not effective. In addition, nimesulide produces a long-lasting neuroprotection. This is of importance since some 'neuroprotective' compounds only produce a delay in cell death, and not a permanent protection. Its several mechanisms of action in neuroprotection make nimesulide a desirable and promising candidate as therapy for acute brain ischemia. This article reviews recent knowledge on the effects of nimesulide against brain injury, with particular emphasis in cerebral ischemia, and makes a critical appraisal of its therapeutic potential in the management of patients with brain ischemia.

  17. Anti-VEGF Therapy for Retinal Vein Occlusions.

    PubMed

    Campa, Claudio; Alivernini, Giuseppe; Bolletta, Elena; Parodi, Maurizio Battaglia; Perri, Paolo

    2016-01-01

    Retinal vein occlusion (RVO) is the second most common cause of visual loss in the Western World. RVO is usually classified into branch RVO (BRVO) and central RVO (CRVO) according to the anatomical site of the vascular occlusion. The pathogenesis of RVO is not yet fully understood, however an important event is the intraluminal thrombus formation, which is usually secondary to several conditions such as hypertension, hyperlipidemia, diabetes and thrombophilia. The blockage of venous circulation causes an elevation of intraluminal pressure in the capillaries, leading to hemorrhages and leakage of fluid within the retina, increase of interstitial pressure and a consequent reduction of retinal perfusion. Ischemia may develop resulting in secretion of vascular endothelial growth factor (VEGF) that causes further vascular leakage and retinal oedema. VEGF has therefore a leading role in RVO pathogenesis and symptoms. As a consequence use of anti-VEGF agents by intravitreal injections has become very common with the aim to improve the clinical outcomes in these patients. Currently 2 anti-VEGF agents (ranimizumab and aflibercept) have been FDA (Food and Drug Administration) and EMA (European Medicine Agency) approved for the treatment of RVO, while another VEGF inhibitor (bevacizumab) is often used "off-label" in clinical practice. Many treatment regimens have been suggested in the clinical trials with these drugs, as monthly injections or injections when needed, however the ideal regimen has not been defined yet. We conducted a systematic review searching MEDLINE for the following terms: retinal vein occlusion, ranibizumab, bevacizumab, aflibercept, vascular endothelial growth factor, macular oedema. Data were extracted by one author (AG and BE) and checked by a second (BPM, CC). Aim of this article was to review available data for each drug, focusing on their efficacy and safety trying to compare their advantages and limits.

  18. Water-soluble acacetin prodrug confers significant cardioprotection against ischemia/reperfusion injury

    PubMed Central

    Liu, Hui; Yang, Lei; Wu, Hui-Jun; Chen, Kui-Hao; Lin, Feng; Li, Gang; Sun, Hai-Ying; Xiao, Guo-Sheng; Wang, Yan; Li, Gui-Rong

    2016-01-01

    The morbidity and mortality of patients with ischemic cardiomyopathy resulted from ischemia/reperfusion injury are very high. The present study investigates whether our previously synthesized water-soluble phosphate prodrug of acacetin was cardioprotective against ischemia/reperfusion injury in an in vivo rat model. We found that intravenous administration of acacetin prodrug (10 mg/kg) decreased the ventricular arrhythmia score and duration, reduced ventricular fibrillation and infarct size, and improved the impaired heart function induced by myocardial ischemia/reperfusion injury in anesthetized rats. The cardioprotective effects were further confirmed with the parent compound acacetin in an ex vivo rat regional ischemia/reperfusion heart model. Molecular mechanism analysis revealed that acacetin prevented the ischemia/reperfusion-induced reduction of the anti-oxidative proteins SOD-2 and thioredoxin, suppressed the release of inflammation cytokines TLR4, IL-6 and TNFα, and decreased myocyte apoptosis induced by ischemia/reperfusion. Our results demonstrate the novel evidence that acacetin prodrug confer significant in vivo cardioprotective effect against ischemia/reperfusion injury by preventing the reduction of endogenous anti-oxidants and the release of inflammatory cytokines, thereby inhibiting cardiomyocytes apoptosis, which suggests that the water-soluble acacetin prodrug is likely useful in the future as a new drug candidate for treating patients with acute coronary syndrome. PMID:27819271

  19. 3-N-butylphthalide improves neuronal morphology after chronic cerebral ischemia

    PubMed Central

    Zhao, Wanhong; Luo, Chao; Wang, Jue; Gong, Jian; Li, Bin; Gong, Yingxia; Wang, Jun; Wang, Hanqin

    2014-01-01

    3-N-butylphthalide is an effective drug for acute ischemic stroke. However, its effects on chronic cerebral ischemia-induced neuronal injury remain poorly understood. Therefore, this study ligated bilateral carotid arteries in 15-month-old rats to simulate chronic cerebral ischemia in aged humans. Aged rats were then intragastrically administered 3-n-butylphthalide. 3-N-butylphthalide administration improved the neuronal morphology in the cerebral cortex and hippocampus of rats with chronic cerebral ischemia, increased choline acetyltransferase activity, and decreased malondialdehyde and amyloid beta levels, and greatly improved cognitive function. These findings suggest that 3-n-butylphthalide alleviates oxidative stress caused by chronic cerebral ischemia, improves cholinergic function, and inhibits amyloid beta accumulation, thereby improving cerebral neuronal injury and cognitive deficits. PMID:25206879

  20. Activation of Bone Marrow-Derived Microglia Promotes Photoreceptor Survival in Inherited Retinal Degeneration

    PubMed Central

    Sasahara, Manabu; Otani, Atsushi; Oishi, Akio; Kojima, Hiroshi; Yodoi, Yuko; Kameda, Takanori; Nakamura, Hajime; Yoshimura, Nagahisa

    2008-01-01

    The role of microglia in neurodegeneration is controversial, although microglial activation in the retina has been shown to provide an early response against infection, injury, ischemia, and degeneration. Here we show that endogenous bone marrow (BM)-derived microglia play a protective role in vascular and neural degeneration in the retinitis pigmentosa model of inherited retinal degeneration. BM-derived cells were recruited to the degenerating retina where they differentiated into microglia and subsequently localized to the degenerating vessels and neurons. Inhibition of stromal-derived factor-1 in the retina reduced the number of BM-derived microglia and accelerated the rate of neurovascular degeneration. Systemic depletion of myeloid progenitors also accelerated the degenerative process. Conversely, activation of BM-derived myeloid progenitors by systemic administration of both granulocyte colony-stimulating factor and erythropoietin resulted in the deceleration of retinal degeneration and the promotion of cone cell survival. These data indicate that BM-derived microglia may play a protective role in retinitis pigmentosa. Functional activation of BM-derived myeloid progenitors by cytokine therapy may provide a novel strategy for the treatment of inherited retinal degeneration and other neurodegenerative diseases, regardless of the underlying genetic defect. PMID:18483210

  1. Electroretinographic assessment of retinal function at high altitude.

    PubMed

    Schatz, Andreas; Willmann, Gabriel; Fischer, M Dominik; Schommer, Kai; Messias, André; Zrenner, Eberhart; Bartz-Schmidt, Karl-Ulrich; Gekeler, Florian

    2013-08-01

    Although hypoxia plays a key role in the pathophysiology of many common and well studied retinal diseases, little is known about the effects of high-altitude hypoxia on retinal function. The aim of the present study was to assess retinal function during exposure to high-altitude hypoxia using electroretinography (ERG). This work is related to the Tübingen High Altitude Ophthalmology (THAO) study. Electroretinography was performed in 14 subjects in Tübingen, Germany (341 m) and at high altitude at La Capanna Regina Margherita, Italy (4,559 m) using an extended protocol to assess functional integrity of various retinal layers. To place findings in the context of acute mountain sickness, correlations between ERG measurements and oxygen saturation, heart rate, and scores of acute mountain sickness (AMS) were calculated. At high altitude, the maximum response of the scotopic sensitivity function, the implicit times of the a- and b-wave of the combined rod-cone responses, and the implicit times of the photopic negative responses (PhNR) were significantly altered. A-wave slopes and i-waves were significantly decreased at high altitude. The strongest correlation was found for PhNR and O2 saturation (r = 0.68; P < 0.05). Of all tested correlations, only the photopic b-wave implicit time (10 cd·s/m(2)) was significantly correlated with severity of AMS (r = 0.57; P < 0.05). ERG data show that retinal function of inner, outer, and ganglion cell layer is altered at high-altitude hypoxia. Interestingly, the most affected ERG parameters are related to combined rod-cone responses, which indicate that phototransduction and visual processing, especially under conditions of rod-cone interaction, are primarily affected at high altitude.

  2. Selective retinal therapy with a continuous line scanning laser

    NASA Astrophysics Data System (ADS)

    Paulus, Yannis M.; Jain, ATul; Gariano, Ray F.; Nomoto, Hiroyuki; Schuele, Georg; Sramek, Christopher; Charalel, Resmi; Palanker, Daniel

    2010-02-01

    This study evaluates the effects of exposure duration, beam diameter, and power on the safety, selectivity, and healing of retinal lesions created using a continuous line scanning laser. A 532 nm laser (PASCALTM) with retinal beam diameters of 40 and 66 μm was applied to 60 eyes of 30 Dutch-Belted rabbits. Retinal exposure duration varied from 15 to 60 μs. Lesions were acutely assessed by ophthalmoscopy and fluorescein angiography (FA). RPE flatmounts were evaluated with live-dead fluorescent assay (LD). Histological analysis was performed at 1 hour, 1 and 3 days, 1 and 2 weeks, and 1 and 2 months following laser treatment. Ophthalmoscopic visibility (OV) of the lesions corresponded to photoreceptor damage on histological analysis at 1 hour. In subvisible lesions, FA and LD yielded similar thresholds of RPE damage. The ratios of the threshold of rupture and of OV to FA visibility (measures of safety and selectivity) increased with decreasing duration and beam diameter. Above the threshold of OV, histology showed focal RPE damage and photoreceptor loss at one day without inner retinal effects. By one week, continuity of photoreceptor and RPE layers was restored. By 1 month, photoreceptors appeared normal while hypertrophy and hyperpigmentation of the RPE persisted. Retinal therapy with a fast scanning continuous laser achieves selective targeting of the RPE and, at higher power, of the photoreceptors. The damage zone in the photoreceptor layer is quickly filled-in, likely due to photoreceptor migration from adjacent zones. Continuous scanning laser can treat large retinal areas within standard eye fixation time.

  3. PIMASERTIB AND SEROUS RETINAL DETACHMENTS

    PubMed Central

    AlAli, Alaa; Bushehri, Ahmad; Park, Jonathan C.; Krema, Hatem

    2016-01-01

    Purpose: To report a case of multifocal serous retinal detachments associated with pimasertib. Methods: The authors report a 26-year-old patient who developed bilateral multifocal serous retinal detachments appearing 2 days after starting pimasertib (as part of a clinical trial investigating its use in low-grade metastatic ovarian cancer) and rapidly resolving 3 days after stopping it. Conclusion: The mechanism of MEK inhibitor induced visual toxicity remains unclear. The pathophysiology of multifocal serous retinal detachments as a complication of pimasertib is still poorly understood. PMID:26444523

  4. Retinal pseudoangiitis after intravitreal triamcinolone

    PubMed Central

    García-Campos, Jose Manuel; García-Basterra, Ignacio; Kamal-Salah, Radua; Baquero-Aranda, Isabel

    2015-01-01

    We present a case of a 40-year-old woman with a fundus image similar to frosted retinal angiitis after undergoing pars plana vitrectomy and intravitreal triamcinolone injection. The patient with diabetic retinopathy was referred to our hospital with vision loss in her right eye secondary to vitreous haemorrhage. After pars plana vitrectomy and injection of triamcinolone acetonide a funduscopy examination revealed deposits of triamcinolone along the retinal vessels simulating a frosted retinal angiitis. Triamcinolone deposits along blood vessels could be the result of the reabsorption process of these crystals by the perivascular macrophages. Further studies are needed. PMID:25678611

  5. Misfolded Proteins and Retinal Dystrophies

    PubMed Central

    Lin, Jonathan H.; LaVail, Matthew M.

    2010-01-01

    Many mutations associated with retinal degeneration lead to the production of misfolded proteins by cells of the retina. Emerging evidence suggests that these abnormal proteins cause cell death by activating the Unfolded Protein Response, a set of conserved intracellular signaling pathways that detect protein misfolding within the endoplasmic reticulum and control protective and proapoptotic signal transduction pathways. Here, we review the misfolded proteins associated with select types of retinitis pigmentosa, Stargadt-like macular degeneration, and Doyne Honeycomb Retinal Dystrophy and discuss the role that endoplasmic reticulum stress and UPR signaling play in their pathogenesis. Last, we review new therapies for these diseases based on preventing protein misfolding in the retina. PMID:20238009

  6. Adenosine triphosphate-induced photoreceptor death and retinal remodeling in rats.

    PubMed

    Vessey, Kirstan A; Greferath, Ursula; Aplin, Felix P; Jobling, Andrew I; Phipps, Joanna A; Ho, Tracy; De Iongh, Robbert U; Fletcher, Erica L

    2014-09-01

    Many common causes of blindness involve the death of retinal photoreceptors, followed by progressive inner retinal cell remodeling. For an inducible model of retinal degeneration to be useful, it must recapitulate these changes. Intravitreal administration of adenosine triphosphate (ATP) has recently been found to induce acute photoreceptor death. The aim of this study was to characterize the chronic effects of ATP on retinal integrity. Five-week-old, dark agouti rats were administered 50 mM ATP into the vitreous of one eye and saline into the other. Vision was assessed using the electroretinogram and optokinetic response and retinal morphology investigated via histology. ATP caused significant loss of visual function within 1 day and loss of 50% of the photoreceptors within 1 week. At 3 months, 80% of photoreceptor nuclei were lost, and total photoreceptor loss occurred by 6 months. The degeneration and remodeling were similar to those found in heritable retinal dystrophies and age-related macular degeneration and included inner retinal neuronal loss, migration, and formation of new synapses; Müller cell gliosis, migration, and scarring; blood vessel loss; and retinal pigment epithelium migration. In addition, extreme degeneration and remodeling events, such as neuronal and glial migration outside the neural retina and proliferative changes in glial cells, were observed. These extreme changes were also observed in the 2-year-old P23H rhodopsin transgenic rat model of retinitis pigmentosa. This ATP-induced model of retinal degeneration may provide a valuable tool for developing pharmaceutical therapies or for testing electronic implants aimed at restoring vision.

  7. Adenosine triphosphate-induced photoreceptor death and retinal remodeling in rats

    PubMed Central

    Vessey, Kirstan A; Greferath, Ursula; Aplin, Felix P; Jobling, Andrew I; Phipps, Joanna A; Ho, Tracy; De Iongh, Robbert U; Fletcher, Erica L

    2014-01-01

    Many common causes of blindness involve the death of retinal photoreceptors, followed by progressive inner retinal cell remodeling. For an inducible model of retinal degeneration to be useful, it must recapitulate these changes. Intravitreal administration of adenosine triphosphate (ATP) has recently been found to induce acute photoreceptor death. The aim of this study was to characterize the chronic effects of ATP on retinal integrity. Five-week-old, dark agouti rats were administered 50 mM ATP into the vitreous of one eye and saline into the other. Vision was assessed using the electroretinogram and optokinetic response and retinal morphology investigated via histology. ATP caused significant loss of visual function within 1 day and loss of 50% of the photoreceptors within 1 week. At 3 months, 80% of photoreceptor nuclei were lost, and total photoreceptor loss occurred by 6 months. The degeneration and remodeling were similar to those found in heritable retinal dystrophies and age-related macular degeneration and included inner retinal neuronal loss, migration, and formation of new synapses; Müller cell gliosis, migration, and scarring; blood vessel loss; and retinal pigment epithelium migration. In addition, extreme degeneration and remodeling events, such as neuronal and glial migration outside the neural retina and proliferative changes in glial cells, were observed. These extreme changes were also observed in the 2-year-old P23H rhodopsin transgenic rat model of retinitis pigmentosa. This ATP-induced model of retinal degeneration may provide a valuable tool for developing pharmaceutical therapies or for testing electronic implants aimed at restoring vision. J. Comp. Neurol. 522:2928–2950, 2014. © 2014 Wiley Periodicals, Inc. PMID:24639102

  8. Flexible retinal electrode array

    DOEpatents

    Okandan, Murat; Wessendorf, Kurt O.; Christenson, Todd R.

    2006-10-24

    An electrode array which has applications for neural stimulation and sensing. The electrode array can include a large number of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. The electrode array can be formed from a combination of bulk and surface micromachining, with electrode tips that can include an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis where the electrodes can be tailored to provide a uniform gentle contact pressure with optional sensing of this contact pressure at one or more of the electrodes.

  9. Dictionary-driven Ischemia Detection from Cardiac Phase-Resolved Myocardial BOLD MRI at Rest

    PubMed Central

    Bevilacqua, Marco; Dharmakumar, Rohan; Tsaftaris, Sotirios A.

    2016-01-01

    Cardiac Phase-resolved Blood-Oxygen-Level Dependent (CP–BOLD) MRI provides a unique opportunity to image an ongoing ischemia at rest. However, it requires post-processing to evaluate the extent of ischemia. To address this, here we propose an unsupervised ischemia detection (UID) method which relies on the inherent spatio-temporal correlation between oxygenation and wall motion to formalize a joint learning and detection problem based on dictionary decomposition. Considering input data of a single subject, it treats ischemia as an anomaly and iteratively learns dictionaries to represent only normal observations (corresponding to myocardial territories remote to ischemia). Anomaly detection is based on a modified version of One-class Support Vector Machines (OCSVM) to regulate directly the margins by incorporating the dictionary-based representation errors. A measure of ischemic extent (IE) is estimated, reflecting the relative portion of the myocardium affected by ischemia. For visualization purposes an ischemia likelihood map is created by estimating posterior probabilities from the OCSVM outputs, thus obtaining how likely the classification is correct. UID is evaluated on synthetic data and in a 2D CP–BOLD data set from a canine experimental model emulating acute coronary syndromes. Comparing early ischemic territories identified with UID against infarct territories (after several hours of ischemia), we find that IE, as measured by UID, is highly correlated (Pearson’s r = 0.84) w.r.t. infarct size. When advances in automated registration and segmentation of CP–BOLD images and full coverage 3D acquisitions become available, we hope that this method can enable pixel-level assessment of ischemia with this truly non-invasive imaging technique. PMID:26292338

  10. Retinal Flip in Rhodopsin Activation?

    PubMed Central

    Feng, Jun; Brown, Michael F.; Mertz, Blake

    2015-01-01

    Rhodopsin is a well-characterized structural model of a G protein-coupled receptor. Photoisomerization of the covalently bound retinal triggers activation. Surprisingly, the x-ray crystal structure of the active Meta-II state has a 180° rotation about the long-axis of the retinal polyene chain. Unbiased microsecond-timescale all-atom molecular dynamics simulations show that the retinal cofactor can flip back to the orientation observed in the inactive state of rhodopsin under conditions favoring the Meta-I state. Our results provide, to our knowledge, the first evidence from molecular dynamics simulations showing how rotation of the retinal ligand within its binding pocket can occur in the activation mechanism of rhodopsin. PMID:26083914

  11. Protein Misfolding and Retinal Degeneration

    PubMed Central

    Tzekov, Radouil; Stein, Linda; Kaushal, Shalesh

    2011-01-01

    The retina is a highly complex and specialized organ that performs preliminary analysis of visual information. Composed of highly metabolically active tissue, the retina requires a precise and well-balanced means of maintaining its functional activity during extended periods of time. Maintenance and regulation of a vast array of different structural and functional proteins is required for normal function of the retina. This process is referred to as protein homeostasis and involves a variety of activities, including protein synthesis, folding, transport, degradation, elimination, and recycling. Deregulation of any of these activities can lead to malfunctioning of the retina, from subtle subclinical signs to severe retinal degenerative diseases leading to blindness. Examples of retinal degenerative diseases caused by disruption of protein homeostasis include retinitis pigmentosa and Stargardt’s disease. A detailed discussion of the role of disruption in protein homeostasis in these and other retinal diseases is presented, followed by examples of some existing and potential treatments. PMID:21825021

  12. [Recurrent intestinal ischemia due to factor VIII].

    PubMed

    Castellanos Monedero, Jesús Javier; Legaz Huidobro, María Luisa; Galindo Andugar, María Angeles; Rodríguez Pérez, Alvaro; Mantrana del Valle, José María

    2008-01-01

    Intestinal ischemia is difficult to diagnose and can be caused by several etiologic processes. We report the case of a female patient with recurrent bowel ischemia due to small vessel thrombosis, which is caused by factor VIII, a procoagulant factor.

  13. [The role of BDNF in brain ischemia pulmonary edema].

    PubMed

    Zhang, Yun-Hui; Wang, Ting-Hua

    2012-11-01

    Brain ischemia pulmonary edema(BIPE)is a critical type of the neurogenic pulmonary edema (NPE), with acute development and progression and high mortality. The study on mechanism of BIPE has important scientific significance and substantial practice values. NPE, as a complicated physiopathology condition, is not resulted from single factor but systemic events including the changes in nervous system, body fluid regulation and endocrine involved in central nervous system after the injury. The studies on this topic in this current issue suggested that brain-derived neurotrophic factor (BDNF) could involve in the pathogenesis procedure of NPE following brain ischemia, which indicated that the crucial role of BDNF in the NPE after BIPE. The findings of these studies pave a way for the treatment of BIPE by using BDNF administration in future clinic trail.

  14. Levosimendan Administration in Limb Ischemia: Multicomponent Signaling Serving Kidney Protection

    PubMed Central

    Onody, Peter; Aranyi, Peter; Turoczi, Zsolt; Stangl, Rita; Fulop, Andras; Dudas, Emese; Lotz, Gabor; Szijarto, Attila

    2016-01-01

    Aims and Objectives Acute renal failure is a severe complication of lower extremity major arterial reconstructions, which could even be fatal. Levosimendan is a dual-acting positive inotropic and vasodilatory agent, which is suspected to have protective effects against cardiac ischemia. However, there is no data available on lower limb or remote organ ischemic injuries therefore the aim of the study was to investigate the effect of levosimendan on lower limb ischemia-reperfusion injury and the corollary renal dysfunction. Methods Male Wistar rats underwent 180 min bilateral lower limb ischemia followed by 4 or 24 hours of reperfusion. Intravenous Levosimendan was administered continuously (0.2μg/bwkg/min) throughout the whole course of ischemia and the first 3h of reperfusion. Results were compared with sham-operated and ischemia-reperfusion groups. Hemodynamic monitoring was performed by invasive arterial blood pressure measurement. Kidney and lower limb muscle microcirculation was registered by a laser Doppler flowmeter. After 4h and 24h of reperfusion, serum, urine and histological samples were collected. Results Systemic hemodynamic parameters and microcirculation of kidney and the lower limb significantly improved in the Levosimendan treated group. Muscle viability was significantly preserved 4 and 24 hours after reperfusion. At the same time, renal functional laboratory tests and kidney histology demonstrated significantly less expressive kidney injury in Levosimendan groups. TNF-α levels were significantly less elevated in the Levosimendan group 4 hours after reperfusion. Conclusion The results claim a protective role for Levosimendan administration during major vascular surgeries to prevent renal complications. PMID:27684548

  15. General Pathophysiology in Retinal Degeneration

    PubMed Central

    Wert, Katherine J.; Lin, Jonathan H.; Tsang, Stephen H.

    2015-01-01

    Retinal degeneration, including that seen in age-related macular degeneration and retinitis pigmentosa (RP), is the most common form of neural degenerative disease in the world. There is great genetic and allelic heterogeneity of the various retinal dystrophies. Classifications of these diseases can be ambiguous, as there are similar clinical presentations in retinal degenerations arising from different genetic mechanisms. As would be expected, alterations in the activity of the phototransduction cascade, such as changes affecting the renewal and shedding of the photoreceptor OS, visual transduction, and/ or retinol metabolism have a great impact on the health of the retina. Mutations within any of the molecules responsible for these visual processes cause several types of retinal and retinal pigment epithelium degenerative diseases. Apoptosis has been implicated in the rod cell loss seen in a mouse model of RP, but the precise mechanisms that connect the activation of these pathways to the loss of phosphodiesterase (PDE6β) function has yet to be defined. Additionally, the activation of apoptosis by CCAAT/-enhancer-binding protein homologous protein (CHOP), after activation of the unfolded protein response pathway, may be responsible for cell death, although the mechanism remains unknown. However, the mechanisms of cell death after loss of function of PDE6, which is a commonly studied mammalian model in research, may be generalizable to loss of function of different key proteins involved in the phototransduction cascade. PMID:24732759

  16. Filling in the retinal image

    NASA Technical Reports Server (NTRS)

    Larimer, James; Piantanida, Thomas

    1990-01-01

    The optics of the eye form an image on a surface at the back of the eyeball called the retina. The retina contains the photoreceptors that sample the image and convert it into a neural signal. The spacing of the photoreceptors in the retina is not uniform and varies with retinal locus. The central retinal field, called the macula, is densely packed with photoreceptors. The packing density falls off rapidly as a function of retinal eccentricity with respect to the macular region and there are regions in which there are no photoreceptors at all. The retinal regions without photoreceptors are called blind spots or scotomas. The neural transformations which convert retinal image signals into percepts fills in the gaps and regularizes the inhomogeneities of the retinal photoreceptor sampling mosaic. The filling-in mechamism plays an important role in understanding visual performance. The filling-in mechanism is not well understood. A systematic collaborative research program at the Ames Research Center and SRI in Menlo Park, California, was designed to explore this mechanism. It was shown that the perceived fields which are in fact different from the image on the retina due to filling-in, control some aspects of performance and not others. Researchers have linked these mechanisms to putative mechanisms of color coding and color constancy.

  17. Retinal implants: a systematic review.

    PubMed

    Chuang, Alice T; Margo, Curtis E; Greenberg, Paul B

    2014-07-01

    Retinal implants present an innovative way of restoring sight in degenerative retinal diseases. Previous reviews of research progress were written by groups developing their own devices. This systematic review objectively compares selected models by examining publications describing five representative retinal prostheses: Argus II, Boston Retinal Implant Project, Epi-Ret 3, Intelligent Medical Implants (IMI) and Alpha-IMS (Retina Implant AG). Publications were analysed using three criteria for interim success: clinical availability, vision restoration potential and long-term biocompatibility. Clinical availability: Argus II is the only device with FDA approval. Argus II and Alpha-IMS have both received the European CE Marking. All others are in clinical trials, except the Boston Retinal Implant, which is in animal studies. Vision restoration: resolution theoretically correlates with electrode number. Among devices with external cameras, the Boston Retinal Implant leads with 100 electrodes, followed by Argus II with 60 electrodes and visual acuity of 20/1262. Instead of an external camera, Alpha-IMS uses a photodiode system dependent on natural eye movements and can deliver visual acuity up to 20/546. Long-term compatibility: IMI offers iterative learning; Epi-Ret 3 is a fully intraocular device; Alpha-IMS uses intraocular photosensitive elements. Merging the results of these three criteria, Alpha-IMS is the most likely to achieve long-term success decades later, beyond current clinical availability.

  18. Retinal oxygen extraction in humans

    NASA Astrophysics Data System (ADS)

    Werkmeister, René M.; Schmidl, Doreen; Aschinger, Gerold; Doblhoff-Dier, Veronika; Palkovits, Stefan; Wirth, Magdalena; Garhöfer, Gerhard; Linsenmeier, Robert A.; Leitgeb, Rainer A.; Schmetterer, Leopold

    2015-10-01

    Adequate function of the retina is dependent on proper oxygen supply. In humans, the inner retina is oxygenated via the retinal circulation. We present a method to calculate total retinal oxygen extraction based on measurement of total retinal blood flow using dual-beam bidirectional Doppler optical coherence tomography and measurement of oxygen saturation by spectrophotometry. These measurements were done on 8 healthy subjects while breathing ambient room air and 100% oxygen. Total retinal blood flow was 44.3 ± 9.0 μl/min during baseline and decreased to 18.7 ± 4.2 μl/min during 100% oxygen breathing (P < 0.001) resulting in a pronounced decrease in retinal oxygen extraction from 2.33 ± 0.51 μl(O2)/min to 0.88 ± 0.14 μl(O2)/min during breathing of 100% oxygen. The method presented in this paper may have significant potential to study oxygen metabolism in hypoxic retinal diseases such as diabetic retinopathy.

  19. Retinal oxygen extraction in humans

    PubMed Central

    Werkmeister, René M.; Schmidl, Doreen; Aschinger, Gerold; Doblhoff-Dier, Veronika; Palkovits, Stefan; Wirth, Magdalena; Garhöfer, Gerhard; Linsenmeier, Robert A.; Leitgeb, Rainer A.; Schmetterer, Leopold

    2015-01-01

    Adequate function of the retina is dependent on proper oxygen supply. In humans, the inner retina is oxygenated via the retinal circulation. We present a method to calculate total retinal oxygen extraction based on measurement of total retinal blood flow using dual-beam bidirectional Doppler optical coherence tomography and measurement of oxygen saturation by spectrophotometry. These measurements were done on 8 healthy subjects while breathing ambient room air and 100% oxygen. Total retinal blood flow was 44.3 ± 9.0 μl/min during baseline and decreased to 18.7 ± 4.2 μl/min during 100% oxygen breathing (P < 0.001) resulting in a pronounced decrease in retinal oxygen extraction from 2.33 ± 0.51 μl(O2)/min to 0.88 ± 0.14 μl(O2)/min during breathing of 100% oxygen. The method presented in this paper may have significant potential to study oxygen metabolism in hypoxic retinal diseases such as diabetic retinopathy. PMID:26503332

  20. Optic neuritis heralding varicella zoster virus retinitis in a patient with acquired immunodeficiency syndrome.

    PubMed

    Meenken, C; van den Horn, G J; de Smet, M D; van der Meer, J T

    1998-04-01

    We report on a 29-year-old severely compromised acquired immunodeficiency syndrome patient who developed retrobulbar optic neuritis 5 weeks after an episode of cutaneous herpes zoster infection. During the optic neuritis, varicella zoster virus could be demonstrated in the cerebrospinal fluid. The neuritis responded well to treatment with foscarnet, but, 3 weeks into therapy, varicella zoster retinitis developed. Additional treatment with intravenous acyclovir stopped progression of the retinitis and resulted in healing of the retinal lesions. This case suggests that retrobulbar optic neuritis can be regarded as a prodrome of imminent acute retinal necrosis. Early recognition and prompt therapy with combined antivirals may prevent the development of this devastating ocular complication of varicella zoster infection.

  1. A case of atypical progressive outer retinal necrosis after highly active antiretroviral therapy.

    PubMed

    Woo, Se Joon; Yu, Hyeong Gon; Chung, Hum

    2004-06-01

    This is a report of an atypical case of progressive outer retinal necrosis (PORN) and the effect of highly active antiretroviral therapy (HAART) on the clinical course of viral retinitis in an acquired immunodeficiency syndrome (AIDS) patient. A 22-year-old male patient infected with human immunodeficiency virus (HIV) presented with unilaterally reduced visual acuity and a dense cataract. After cataract extraction, retinal lesions involving the peripheral and macular areas were found with perivascular sparing and the mud-cracked, characteristic appearance of PORN. He was diagnosed as having PORN based on clinical features and was given combined antiviral treatment. With concurrent HAART, the retinal lesions regressed, with the regression being accelerated by further treatment with intravenous acyclovir and ganciclovir. This case suggests that HAART may change the clinical course of PORN in AIDS patients by improving host immunity. PORN should be included in the differential diagnosis of acute unilateral cataract in AIDS patients.

  2. Animal models of cerebral ischemia

    NASA Astrophysics Data System (ADS)

    Khodanovich, M. Yu.; Kisel, A. A.

    2015-11-01

    Cerebral ischemia remains one of the most frequent causes of death and disability worldwide. Animal models are necessary to understand complex molecular mechanisms of brain damage as well as for the development of new therapies for stroke. This review considers a certain range of animal models of cerebral ischemia, including several types of focal and global ischemia. Since animal models vary in specificity for the human disease which they reproduce, the complexity of surgery, infarct size, reliability of reproduction for statistical analysis, and adequate models need to be chosen according to the aim of a study. The reproduction of a particular animal model needs to be evaluated using appropriate tools, including the behavioral assessment of injury and non-invasive and post-mortem control of brain damage. These problems also have been summarized in the review.

  3. Changes of hypoxia-inducible factor-1 signaling and the effect of cilostazol in chronic cerebral ischemia

    PubMed Central

    Chen, Han; Wei, Aixuan; He, Jinting; Yu, Ming; Mang, Jing; Xu, Zhongxin

    2013-01-01

    Hypoxia-inducible factor-1 and its specific target gene heme oxygenase-1, are involved in acute cerebral ischemia. However, very few studies have examined in detail the changes in the hypoxia-inducible factor-1/heme oxygenase-1 signaling pathway in chronic cerebral ischemia. In this study, a rat model of chronic cerebral ischemia was established by permanent bilateral common carotid artery occlusion, and these rats were treated with intragastric cilostazol (30 mg/kg) for 9 weeks. Morris water maze results showed that cognitive impairment gradually worsened as the cerebral ischemia proceeded. Immunohistochemistry, semi-quantitative PCR and western blot analysis showed that hypoxia-inducible factor-1α and heme oxygenase-1 expression levels increased after chronic cerebral ischemia, with hypoxia-inducible factor-1α expression peaking at 3 weeks and heme oxygenase-1 expression peaking at 6 weeks. These results suggest that the elevated levels of hypoxia-inducible factor-1α may upregulate heme oxygenase-1 expression following chronic cerebral ischemia and that the hypoxia-inducible factor-1/heme oxygenase-1 signaling pathway is involved in the development of cognitive impairment induced by chronic cerebral ischemia. Cilostazol treatment alleviated the cognitive impairment in rats with chronic cerebral ischemia, decreased hypoxia-inducible factor-1α and heme oxygenase-1 expression levels, and reduced apoptosis in the frontal cortex. These findings demonstrate that cilostazol can protect against cognitive impairment induced by chronic cerebral ischemic injury through an anti-apoptotic mechanism. PMID:25206477

  4. Ruptured retinal arterial macroaneurysm: diagnosis and management.

    PubMed

    Speilburg, Ashley M; Klemencic, Stephanie A

    2014-01-01

    Retinal arterial macroaneurysm is an acquired, focal dilation of a retinal artery, typically occurring within the first three bifurcations of the central retinal artery. The clinical presentation of a retinal arterial macroaneurysm is highly variable, making initial diagnosis difficult and differentials many. Identification of retinal arterial macroaneurysms is crucial to appropriately co-manage with the primary care physician for hypertension control. Prognosis is generally good and observation is often an adequate treatment. However, in cases of macular threat or involvement, some treatment options are available and referral to a retinal specialist is indicated.

  5. PARP Inhibition Attenuates Histopathological Lesion in Ischemia/Reperfusion Renal Mouse Model after Cold Prolonged Ischemia

    PubMed Central

    del Moral, Raimundo M. G.; Gómez-Morales, Mercedes; Aguilar, David; Caballero, Trinidad; Aneiros-Fernández, Jose; Caba-Molina, Mercedes; Rodríguez-Martínez, Mª  Dolores; Peralta, Andreina; Galindo-Moreno, Pablo; Osuna, Antonio; Oliver, F. Javier

    2013-01-01

    We test the hypothesis that PARP inhibition can decrease acute tubular necrosis (ATN) and other renal lesions related to prolonged cold ischemia/reperfusion (IR) in kidneys preserved at 4°C in University of Wisconsin (UW) solution. Material and Methods. We used 30 male Parp1+/+ wild-type and 15 male Parp10/0 knockout C57BL/6 mice. Fifteen of these wild-type mice were pretreated with 3,4-dihydro-5-[4-(1-piperidinyl)butoxyl]-1(2H)-isoquinolinone (DPQ) at a concentration of 15 mg/kg body weight, used as PARP inhibitor. Subgroups of mice were established (A: IR 45 min/6 h; B: IR + 48 h in UW solution; and C: IR + 48 h in UW solution plus DPQ). We processed samples for morphological, immunohistochemical, ultrastructural, and western-blotting studies. Results. Prolonged cold ischemia time in UW solution increased PARP-1 expression and kidney injury. Preconditioning with PARP inhibitor DPQ plus DPQ supplementation in UW solution decreased PARP-1 nuclear expression in renal tubules and renal damage. Parp10/0 knockout mice were more resistant to IR-induced renal lesion. In conclusion, PARP inhibition attenuates ATN and other IR-related renal lesions in mouse kidneys under prolonged cold storage in UW solution. If confirmed, these data suggest that pharmacological manipulation of PARP activity may have salutary effects in cold-stored organs at transplantation. PMID:24319370

  6. Stenting in Acute Lower Limb Arterial Occlusions

    SciTech Connect

    Raja, Jowad; Munneke, Graham; Morgan, Robert; Belli, Anna-Maria

    2008-07-15

    Management of critical limb ischemia of acute onset includes surgical embolectomy, bypass grafting, aspiration thrombectomy, thrombolysis, and mechanical thrombectomy followed by treatment of the underlying cause. We present our experience with the use of stents to treat acute embolic/thrombotic occlusions in one iliac and three femoropopliteal arteries. Although this is a small case series, excellent immediate and midterm results suggest that stenting of acute occlusions of the iliac, superficial femoral, and popliteal arteries is a safe and effective treatment option.

  7. Controversies in cardiovascular care: silent myocardial ischemia

    NASA Technical Reports Server (NTRS)

    Hollenberg, N. K.

    1987-01-01

    The objective evidence of silent myocardial ischemia--ischemia in the absence of classical chest pain--includes ST-segment shifts (usually depression), momentary left ventricular failure, and perfusion defects on scintigraphic studies. Assessment of angina patients with 24-hour ambulatory monitoring may uncover episodes of silent ischemia, the existence of which may give important information regarding prognosis and may help structure a more effective therapeutic regimen. The emerging recognition of silent ischemia as a significant clinical entity may eventually result in an expansion of current therapy--not only to ameliorate chest pain, but to minimize or eliminate ischemia in the absence of chest pain.

  8. [The adrenergic mechanisms are involved in the pulmonary hemodynamics changes following experimental myocardial ischemia in rabbits].

    PubMed

    Evlakhov, V I; Poiasov, I Z

    2012-05-01

    In acute experiments in anesthetized rabbits the changes of the pulmonary hemodynamics following myocardial ischemia in the region of the descendent left coronary artery were studied in control animals and after the blockade of alpha-adrenoreceptors by phentolamine or N-cholinoreceptors of autonomic ganglia by hexamethonium. Following myocardial ischemia in control animals the pulmonary artery pressure and flow decreased, the pulmonary vascular resistance was elevated not significantly, the cardiac output decreased more than pulmonary artery flow. Following myocardial ischemia after the blockade of alpha-adrenoreceptors the pulmonary artery flow and cardiac output decreased in the same level and the pulmonary vascular resistance was decreased. In these conditions the pulmonary artery pressure decreased more than in control animals, meanwhile the pulmonary artery flow was decreased in the same level as in the last case. Following myocardial ischemia after the blockade of N-cholinoreceptors the pulmonary hemodynamics changes were the same as they were following myocardial ischemia in the control rabbits, the cardiac output decreased more than pulmonary artery flow. The disbalance of the cardiac output and pulmonary artery flow changes in the case of myocardial ischemia was caused by the pulmonary vessel reactions following activations of the humoral adrenergic mechanisms.

  9. Selective Estrogen Receptor Modulators (SERMs) Enhance Neurogenesis and Spine Density Following Focal Cerebral Ischemia

    PubMed Central

    Khan, Mohammad M.; Wakade, Chandramohan; de Sevilla, Liesl; Brann, Darrell W.

    2014-01-01

    Selective estrogen receptor modulators (SERMs) have been reported to enhance synaptic plasticity and improve cognitive performance in adult rats. SERMs have also been shown to induce neuroprotection against cerebral ischemia and other CNS insults. In this study, we sought to determine whether acute regulation of neurogenesis and spine remodeling could be a novel mechanism associated with neuroprotection induced by SERMs following cerebral ischemia. Toward this end, ovariectomized adult female rats were either implanted with pellets of 17β-estradiol (estrogen) or tamoxifen, or injected with raloxifene. After one week, cerebral ischemia was induced by the transient middle-cerebral artery occlusion (MCAO) method. Bromodeoxyuridine (BrdU) was injected to label dividing cells in brain. We analyzed neurogenesis and spine density at day-1 and day-5 post MCAO. In agreement with earlier findings, we observed a robust induction of neurogenesis in the ipsilateral subventricular zone (SVZ) of both the intact as well as ovariectomized female rats following MCAO. Interestingly, neurogenesis in the ipsilateral SVZ following ischemia was significantly higher in estrogen and raloxifene-treated animals compared to placebo-treated rats. In contrast, this enhancing effect on neurogenesis was not observed in tamoxifen-treated rats. Finally, both SERMs, as well as estrogen significantly reversed the spine density loss observed in the ischemic cortex at day-5 post ischemia. Taken, together these results reveal a profound structural remodeling potential of SERMs in the brain following cerebral ischemia. PMID:24815952

  10. Selective estrogen receptor modulators (SERMs) enhance neurogenesis and spine density following focal cerebral ischemia.

    PubMed

    Khan, Mohammad M; Wakade, Chandramohan; de Sevilla, Liesl; Brann, Darrell W

    2015-02-01

    Selective estrogen receptor modulators (SERMs) have been reported to enhance synaptic plasticity and improve cognitive performance in adult rats. SERMs have also been shown to induce neuroprotection against cerebral ischemia and other CNS insults. In this study, we sought to determine whether acute regulation of neurogenesis and spine remodeling could be a novel mechanism associated with neuroprotection induced by SERMs following cerebral ischemia. Toward this end, ovariectomized adult female rats were either implanted with pellets of 17β-estradiol (estrogen) or tamoxifen, or injected with raloxifene. After one week, cerebral ischemia was induced by the transient middle-cerebral artery occlusion (MCAO) method. Bromodeoxyuridine (BrdU) was injected to label dividing cells in brain. We analyzed neurogenesis and spine density at day-1 and day-5 post MCAO. In agreement with earlier findings, we observed a robust induction of neurogenesis in the ipsilateral subventricular zone (SVZ) of both the intact as well as ovariectomized female rats following MCAO. Interestingly, neurogenesis in the ipsilateral SVZ following ischemia was significantly higher in estrogen and raloxifene-treated animals compared to placebo-treated rats. In contrast, this enhancing effect on neurogenesis was not observed in tamoxifen-treated rats. Finally, both SERMs, as well as estrogen significantly reversed the spine density loss observed in the ischemic cortex at day-5 post ischemia. Taken, together these results reveal a profound structural remodeling potential of SERMs in the brain following cerebral ischemia. This article is part of a Special Issue entitled "Sex steroids and brain disorders".

  11. Retinal AO OCT

    NASA Astrophysics Data System (ADS)

    Zawadzki, Robert J.; Miller, Donald T.

    The last two decades have witnessed extraordinary advances in optical technology to image noninvasively and at high resolution the posterior segment of the eye. Two of the most impactful technological advancements over this period have arguably been optical coherence tomography (OCT) and adaptive optics (AO). The strengths of these technologies complement each other and when combined have been shown to provide unprecedented, micron-scale resolution (<3 μm) in all three dimensions and sensitivity to image the cellular retina in the living eye. This powerful extension of OCT, that is AO-OCT, is the focus of this chapter. It presents key aspects of designing and implementing AO-OCT systems. Particular attention is devoted to the relevant optical properties of the eye that ultimately define these systems, AO componentry and operation tailored for ophthalmic use, and of course use of the latest technologies and methods in OCT for ocular imaging. It surveys the wide range of AO-OCT designs that have been developed for retinal imaging, with AO integrated into every major OCT design configuration. Finally, it reviews the scientific and clinical studies reported to date that show the exciting potential of AO-OCT to image the microscopic retina and fundus in ways not previously possible with other noninvasive methods and a look to future developments in this rapidly growing field.

  12. Sum of effects of myocardial ischemia followed by electrically induced tachycardia on myocardial function

    PubMed Central

    Díez, José Luis; Hernándiz, Amparo; Cosín-Aguilar, Juan; Aguilar, Amparo; Portolés, Manuel

    2013-01-01

    Background The alteration of contractile function after tachyarrhythmia ceases is influenced by the type of prior ischemia (acute coronary syndrome or ischemia inherent in a coronary revascularization procedure). We aimed to analyze cardiac dysfunction in an acute experimental model of supraphysiological heart rate preceded by different durations and types of ischemia. Material/Methods Twenty-four pigs were included in: (S1) series of ventricular pacing; (S2, A and B) series with 10 or 20 min, respectively, of coronary occlusion previous to ventricular pacing; S3 with 20 brief, repeated ischemia/reperfusion processes prior to ventricular pacing and; (S4) control series. Overall cardiac function parameters and regional myocardial contractility at the apex and base of the left ventricle were recorded, as were oxidative stress markers (glutathione and lipid peroxide serum levels). Left ventricular pacing at 60% over baseline heart rate was performed for 2 h followed by 1 h of recovery. Results High ventricular pacing rates preceded by short, repeated periods of coronary ischemia/reperfusion resulted in worse impairment of overall cardiac and regional function that continued to be altered 1 h after tachycardia ceased. There was significant reduction of stroke volume (26.9±5.3 basal vs. 16±6.2 ml; p<0.05), LVP; dP/dt and LAD flow (13.1±1.5 basal vs. 8.4±1.6 ml/min; p<0.05); the base contractility remained altered when recovering compared to baseline (base SF: 5.6±2.8 vs. 2.2±0.7%; p<0.05); and LPO levels were higher than less aggressive series at the end of recovery. Conclusions Ischemia and tachycardia accumulate their effects, with increased cardiac involvement depending on the type of ischemia. PMID:23722244

  13. Sirt1 in cerebral ischemia

    PubMed Central

    Koronowski, Kevin B.; Perez-Pinzon, Miguel A.

    2015-01-01

    Cerebral ischemia is among the leading causes of death worldwide. It is characterized by a lack of blood flow to the brain that results in cell death and damage, ultimately causing motor, sensory, and cognitive impairments. Today, clinical treatment of cerebral ischemia, mostly stroke and cardiac arrest, is limited and new neuroprotective therapies are desperately needed. The Sirtuin family of oxidized nicotinamide adenine dinucleotide (NAD+)-dependent deacylases has been shown to govern several processes within the central nervous system as well as to possess neuroprotective properties in a variety of pathological conditions such as Alzheimer’s Disease, Parkinson’s Disease, and Huntington’s Disease, among others. Recently, Sirt1 in particular has been identified as a mediator of cerebral ischemia, with potential as a possible therapeutic target. To gather studies relevant to this topic, we used PubMed and previous reviews to locate, select, and resynthesize the lines of evidence presented here. In this review, we will first describe some functions of Sirt1 in the brain, mainly neurodevelopment, learning and memory, and metabolic regulation. Second, we will discuss the experimental evidence that has implicated Sirt1 as a key protein in the regulation of cerebral ischemia as well as a potential target for the induction of ischemic tolerance. PMID:26819971

  14. Rhegmatogenous retinal detachment treatment guidelines.

    PubMed

    García-Arumí, J; Martínez-Castillo, V; Boixadera, A; Blasco, H; Marticorena, J; Zapata, M Á; Macià, C; Badal, J; Distéfano, L; Rafart, J M; Berrocal, M; Zambrano, A; Ruíz-Moreno, J M; Figueroa, M S

    2013-01-01

    This paper outlines general guidelines following the initial diagnosis of rhegmatogenous retinal detachment. These include preoperative evaluation, treatment, possible intra- and post-operative complications, retinal re-detachment, and all therapeutic options available for each case. Treatment of the traumatic retinal detachment is also described, due to its importance and peculiarities. Treatment or prophylactic guidelines are suggested for the different types of retinal detachment described. These are based on both the experience of the ophthalmologists that have participated in preparing the guidelines, and also on evidence-based grading linked to bibliographical sources. However, these guidelines should not be interpreted as being mandatory. Given that there is a wide spectrum of options for treatment of retinal detachment, the surgeons' experience with one or other surgical technique will be of utmost importance in obtaining the best surgical result. As guidelines, they are intended as an additional aid to the surgeon during the decision-making process, with the expectation that the final choice will still be left to the surgeon's judgment and past experience.

  15. Oxidative stress in brain ischemia.

    PubMed

    Love, S

    1999-01-01

    Brain ischemia initiates a complex cascade of metabolic events, several of which involve the generation of nitrogen and oxygen free radicals. These free radicals and related reactive chemical species mediate much of damage that occurs after transient brain ischemia, and in the penumbral region of infarcts caused by permanent ischemia. Nitric oxide, a water- and lipid-soluble free radical, is generated by the action of nitric oxide synthases. Ischemia causes a surge in nitric oxide synthase 1 (NOS 1) activity in neurons and, possibly, glia, increased NOS 3 activity in vascular endothelium, and later an increase in NOS 2 activity in a range of cells including infiltrating neutrophils and macrophages, activated microglia and astrocytes. The effects of ischemia on the activity of NOS 1, a Ca2+-dependent enzyme, are thought to be secondary to reversal of glutamate reuptake at synapses, activation of NMDA receptors, and resulting elevation of intracellular Ca2+. The up-regulation of NOS 2 activity is mediated by transcriptional inducers. In the context of brain ischemia, the activity of NOS 1 and NOS 2 is broadly deleterious, and their inhibition or inactivation is neuroprotective. However, the production of nitric oxide in blood vessels by NOS 3, which, like NOS 1, is Ca2+-dependent, causes vasodilatation and improves blood flow in the penumbral region of brain infarcts. In addition to causing the synthesis of nitric oxide, brain ischemia leads to the generation of superoxide, through the action of nitric oxide synthases, xanthine oxidase, leakage from the mitochondrial electron transport chain, and other mechanisms. Nitric oxide and superoxide are themselves highly reactive but can also combine to form a highly toxic anion, peroxynitrite. The toxicity of the free radicals and peroxynitrite results from their modification of macromolecules, especially DNA, and from the resulting induction of apoptotic and necrotic pathways. The mode of cell death that prevails probably

  16. [Congenital retinal folds in different clinical cases].

    PubMed

    Munteanu, M

    2005-01-01

    We present 12 clinical cases of congenital retinal folds with different etiologies: posterior primitive vitreous persistency and hyperplasia (7 cases),retinocytoma (1 case). retinopathy of prematurity (1 case), astrocytoma of the retina (1 case), retinal vasculitis (1 case), Goldmann-Favre syndrome (1 case). Etiopathogenic and nosological aspects are discussed; the congenital retinal folds are interpreted as a symptom in a context of a congenital or acquired vitreo-retinal pathology.

  17. [Unusual retinal abnormality: retinal hemorrhages related to scurvy].

    PubMed

    Errera, M-H; Dupas, B; Man, H; Gualino, V; Gaudric, A; Massin, P

    2011-03-01

    A diet restricted to rice and boiled fruit and vegetables leads to vitamin C deficiency. We describe the third case, to our knowledge, of retinal hemorrhages related to scurvy. Reduced bilateral visual acuity in a 50-year-old patient was associated with macrocytic anemia, denutrition, and cutaneous ecchymoses. Oral vitamin C treatment provided subjective clinical improvement and regression of the retinal hemorrhages on fundus examination, with no side effects. Vitamin C plays an important role in collagen stability in vascular and bone walls.

  18. Hepcidin Mitigates Renal Ischemia-Reperfusion Injury by Modulating Systemic Iron Homeostasis.

    PubMed

    Scindia, Yogesh; Dey, Paromita; Thirunagari, Abhinav; Liping, Huang; Rosin, Diane L; Floris, Matteo; Okusa, Mark D; Swaminathan, Sundararaman

    2015-11-01

    Iron-mediated oxidative stress is implicated in the pathogenesis of renal ischemia-reperfusion injury. Hepcidin is an endogenous acute phase hepatic hormone that prevents iron export from cells by inducing degradation of the only known iron export protein, ferroportin. In this study, we used a mouse model to investigate the effect of renal ischemia-reperfusion injury on systemic iron homeostasis and determine if dynamic modulation of iron homeostasis with hepcidin has therapeutic benefit in the treatment of AKI. Renal ischemia-reperfusion injury induced hepatosplenic iron export through increased ferroportin expression, which resulted in hepatosplenic iron depletion and an increase in serum and kidney nonheme iron levels. Exogenous hepcidin treatment prevented renal ischemia-reperfusion-induced changes in iron homeostasis. Hepcidin also decreased kidney ferroportin expression and increased the expression of cytoprotective H-ferritin. Hepcidin-induced restoration of iron homeostasis was accompanied by a significant reduction in ischemia-reperfusion-induced tubular injury, apoptosis, renal oxidative stress, and inflammatory cell infiltration. Hepcidin -: deficient mice demonstrated increased susceptibility to ischemia-reperfusion injury compared with wild-type mice. Reconstituting hepcidin-deficient mice with exogenous hepcidin induced hepatic iron sequestration, attenuated the reduction in renal H-ferritin and reduced renal oxidative stress, apoptosis, inflammation, and tubular injury. Hepcidin-mediated protection was associated with reduced serum IL-6 levels. In summary, renal ischemia-reperfusion injury results in profound alterations in systemic iron homeostasis. Hepcidin treatment restores iron homeostasis and reduces inflammation to mediate protection in renal ischemia-reperfusion injury, suggesting that hepcidin-ferroportin pathway holds promise as a novel therapeutic target in the treatment of AKI.

  19. Noninvasive Multimodal Imaging to Predict Recovery of Locomotion after Extended Limb Ischemia.

    PubMed

    Radowsky, Jason S; Caruso, Joseph D; Luthra, Rajiv; Bradley, Matthew J; Elster, Eric A; Forsberg, Jonathan A; Crane, Nicole J

    2015-01-01

    Acute limb ischemia is a common cause of morbidity and mortality following trauma both in civilian centers and in combat related injuries. Rapid determination of tissue viability and surgical restoration of blood flow are desirable, but not always possible. We sought to characterize the response to increasing periods of hind limb ischemia in a porcine model such that we could define a period of critical ischemia (the point after which irreversible neuromuscular injury occurs), evaluate non-invasive methods for characterizing that ischemia, and establish a model by which we could predict whether or not the animal's locomotion would return to baselines levels post-operatively. Ischemia was induced by either application of a pneumatic tourniquet or vessel occlusion (performed by clamping the proximal iliac artery and vein at the level of the inguinal ligament). The limb was monitored for the duration of the procedure with both 3-charge coupled device (3CCD) and infrared (IR) imaging for tissue oxygenation and perfusion, respectively. The experimental arms of this model are effective at inducing histologically evident muscle injury with some evidence of expected secondary organ damage, particularly in animals with longer ischemia times. Noninvasive imaging data shows excellent correlation with post-operative functional outcomes, validating its use as a non-invasive means of viability assessment, and directly monitors post-occlusive reactive hyperemia. A classification model, based on partial-least squares discriminant analysis (PLSDA) of imaging variables only, successfully classified animals as "returned to normal locomotion" or "did not return to normal locomotion" with 87.5% sensitivity and 66.7% specificity after cross-validation. PLSDA models generated from non-imaging data were not as accurate (AUC of 0.53) compared the PLSDA model generated from only imaging data (AUC of 0.76). With some modification, this limb ischemia model could also serve as a means on which

  20. Spinal cord ischemia resulting in paraplegia following extrapleural pneumonectomy.

    PubMed

    Ural, Kelly; Jakob, Kyle; Lato, Scott; Gilly, George; Landreneau, Rodney

    2014-08-01

    A patient undergoing radical extrapleural pneumonectomy for epithelioid malignant mesothelioma developed acute paraplegia postoperatively related to long-segment spinal cord ischemia. The usual area of concern for this complication is the T9 to T12 area where the artery of Adamkiewicz is most likely to originate. In this patient, there was ligation of only upper thoracic, ipsilateral segmental arteries from the T3 to T6 level, yet he still developed paraplegia. Our hypothesis is variant mid-thoracic vascular anatomy. Previously unreported, to our knowledge, this should be understood as a rare complication of this surgery.

  1. Choroidal melanoma clinically simulating a retinal angioma.

    PubMed

    Shields, J A; Joffe, L; Guibor, P

    1978-01-01

    An amelanotic fundus lesion in a 35-year-old man was associated with a dilated retinal vessel, thus suggesting the diagnosis of retinal angioma. Fluorescein angiography and B-scan ultrasonography were not diagnostic, but a radioactive phosphorus uptake test suggested the lesion was malignant. The enucleated globe showed a malignant choroidal melanoma drained by a large retinal vein.

  2. Transcorneal Electrical Stimulation Therapy for Retinal Disease

    ClinicalTrials.gov

    2012-05-03

    Retinitis Pigmentosa; Macula Off; Primary Open Angle Glaucoma; Hereditary Macular Degeneration; Treated Retina Detachment; Retinal Artery Occlusion; Retinal Vein Occlusion; Non-Arthritic-Anterior-Ischemic Optic-Neuropathy; Hereditary Autosomal Dominant Optic Atrophy; Dry Age Related Macular Degeneration; Ischemic Macula Edema

  3. Inherited Retinal Degenerative Clinical Trial Network

    DTIC Science & Technology

    2009-10-01

    ending in blindness. In the United States, the total number of individuals affected by retinitis pigmentosa (RP) and other forms of rare inherited...AD_________________ AWARD NUMBER: W81XWH-07-1-0720 TITLE: Inherited Retinal Degenerative...Final 3. DATES COVERED 27 Sep 2007 – 29 Sep 2009 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Inherited Retinal Degenerative Clinical Trial Network

  4. Differential gene expression profiling of large and small retinal ganglion cells

    PubMed Central

    Ivanov, Dmitry; Dvoriantchikova, Galina; Barakat, David J.; Nathanson, Lubov; Shestopalov, Valery I.

    2014-01-01

    Different sub-populations of retinal ganglion cells (RGCs) vary in their sensitivity to pathological conditions such as retinal ischemia, diabetic retinopathy and glaucoma. Comparative transcriptomic analysis of such groups will likely reveal molecular determinants of differential sensitivity to stress. However, gene expression profiling of primary neuronal sub-populations represent a challenge due to the cellular heterogeneity of retinal tissue. In this manuscript, we report the use of a fluorescent neural tracer to specifically label and selectively isolate RGCs with different soma sizes by fluorescence-activated cell sorting (FACS) for the purpose of differential gene expression profiling. We identified 145 genes that were more active in the large RGCs and 312 genes in the small RGCs. Differential data were validated by quantitative RT-PCR, several corresponding proteins were confirmed by immunohistochemistry. Functional characterization revealed differential activity of genes implicated in synaptic transmission, neurotransmitter secretion, axon guidance, chemotaxis, ion transport and tolerance to stress. An in silico reconstruction of cellular networks suggested that differences in pathway activity between the two sub-populations of RGCs are controlled by networks interconnected by SP-1, Erk2(MAPK1), Egr1, Egr2 and, potentially, regulated via transcription factors C/EBPbeta, HSF1, STAT1- and c-Myc. The results show that FACS-aided purification of retrogradely labeled cells can be effectively utilized for transcriptional profiling of adult retinal neurons. PMID:18640154

  5. Exploring the retinal connectome

    PubMed Central

    Anderson, James R.; Jones, Bryan W.; Watt, Carl B.; Shaw, Margaret V.; Yang, Jia-Hui; DeMill, David; Lauritzen, James S.; Lin, Yanhua; Rapp, Kevin D.; Mastronarde, David; Koshevoy, Pavel; Grimm, Bradley; Tasdizen, Tolga; Whitaker, Ross

    2011-01-01

    Purpose A connectome is a comprehensive description of synaptic connectivity for a neural domain. Our goal was to produce a connectome data set for the inner plexiform layer of the mammalian retina. This paper describes our first retinal connectome, validates the method, and provides key initial findings. Methods We acquired and assembled a 16.5 terabyte connectome data set RC1 for the rabbit retina at ≈2 nm resolution using automated transmission electron microscope imaging, automated mosaicking, and automated volume registration. RC1 represents a column of tissue 0.25 mm in diameter, spanning the inner nuclear, inner plexiform, and ganglion cell layers. To enhance ultrastructural tracing, we included molecular markers for 4-aminobutyrate (GABA), glutamate, glycine, taurine, glutamine, and the in vivo activity marker, 1-amino-4-guanidobutane. This enabled us to distinguish GABAergic and glycinergic amacrine cells; to identify ON bipolar cells coupled to glycinergic cells; and to discriminate different kinds of bipolar, amacrine, and ganglion cells based on their molecular signatures and activity. The data set was explored and annotated with Viking, our multiuser navigation tool. Annotations were exported to additional applications to render cells, visualize network graphs, and query the database. Results Exploration of RC1 showed that the 2 nm resolution readily recapitulated well known connections and revealed several new features of retinal organization: (1) The well known AII amacrine cell pathway displayed more complexity than previously reported, with no less than 17 distinct signaling modes, including ribbon synapse inputs from OFF bipolar cells, wide-field ON cone bipolar cells and rod bipolar cells, and extensive input from cone-pathway amacrine cells. (2) The axons of most cone bipolar cells formed a distinct signal integration compartment, with ON cone bipolar cell axonal synapses targeting diverse cell types. Both ON and OFF bipolar cells receive

  6. Clinical Trials in Retinal Dystrophies

    PubMed Central

    Grob, Seanna R.; Finn, Avni; Papakostas, Thanos D.; Eliott, Dean

    2016-01-01

    Research development is burgeoning for genetic and cellular therapy for retinal dystrophies. These dystrophies are the focus of many research efforts due to the unique biology and accessibility of the eye, the transformative advances in ocular imaging technology that allows for in vivo monitoring, and the potential benefit people would gain from success in the field – the gift of renewed sight. Progress in the field has revealed the immense complexity of retinal dystrophies and the challenges faced by researchers in the development of this technology. This study reviews the current trials and advancements in genetic and cellular therapy in the treatment of retinal dystrophies and also discusses the current and potential future challenges. PMID:26957839

  7. Rat retinal transcriptome

    PubMed Central

    Kozhevnikova, Oyuna S.; Korbolina, Elena E.; Ershov, Nikita I.; Kolosova, Natalia G.

    2013-01-01

    Pathogenesis of age-related macular degeneration (AMD), the leading cause of vision loss in the elderly, remains poorly understood due to the paucity of animal models that fully replicate the human disease. Recently, we showed that senescence-accelerated OXYS rats develop a retinopathy similar to human AMD. To identify alterations in response to normal aging and progression of AMD-like retinopathy, we compared gene expression profiles of retina from 3- and 18-mo-old OXYS and control Wistar rats by means of high-throughput RNA sequencing (RNA-Seq). We identified 160 and 146 age-regulated genes in Wistar and OXYS retinas, respectively. The majority of them are related to the immune system and extracellular matrix turnover. Only 24 age-regulated genes were common for the two strains, suggestive of different rates and mechanisms of aging. Over 600 genes showed significant differences in expression between the two strains. These genes are involved in disease-associated pathways such as immune response, inflammation, apoptosis, Ca2+ homeostasis and oxidative stress. The altered expression for selected genes was confirmed by qRT-PCR analysis. To our knowledge, this study represents the first analysis of retinal transcriptome from young and old rats with biologic replicates generated by RNA-Seq technology. We can conclude that the development of AMD-like retinopathy in OXYS rats is associated with an imbalance in immune and inflammatory responses. Aging alters the expression profile of numerous genes in the retina, and the genetic background of OXYS rats has a profound impact on the development of AMD-like retinopathy. PMID:23656783

  8. Retinal Optical Coherence Tomography Imaging

    NASA Astrophysics Data System (ADS)

    Drexler, Wolfgang; Fujimoto, James G.

    The eye is essentially transparent, transmitting light with only minimal optical attenuation and scattering providing easy optical access to the anterior segment as well as the retina. For this reason, ophthalmic and especially retinal imaging has been not only the first but also most successful clinical application for optical coherence tomography (OCT). This chapter focuses on the development of OCT technology for retinal imaging. OCT has significantly improved the potential for early diagnosis, understanding of retinal disease pathogenesis, as well as monitoring disease progression and response to therapy. Development of ultrabroad bandwidth light sources and high-speed detection techniques has enabled significant improvements in ophthalmic OCT imaging performance, demonstrating the potential of three-dimensional, ultrahigh-resolution OCT (UHR OCT) to perform noninvasive optical biopsy of the living human retina, i.e., the in vivo visualization of microstructural, intraretinal morphology in situ approaching the resolution of conventional histopathology. Significant improvements in axial resolution and speed not only enable three-dimensional rendering of retinal volumes but also high-definition, two-dimensional tomograms, topographic thickness maps of all major intraretinal layers, as well as volumetric quantification of pathologic intraretinal changes. These advances in OCT technology have also been successfully applied in several animal models of retinal pathologies. The development of light sources emitting at alternative wavelengths, e.g., around #1,060 nm, not only enabled three-dimensional OCT imaging with enhanced choroidal visualization but also improved OCT performance in cataract patients due to reduced scattering losses in this wavelength region. Adaptive optics using deformable mirror technology, with unique high stroke to correct higher-order ocular aberrations, with specially designed optics to compensate chromatic aberration of the human eye, in

  9. Retinal Image Quality During Accommodation

    PubMed Central

    López-Gil, N.; Martin, J.; Liu, T.; Bradley, A.; Díaz-Muñoz, D.; Thibos, L.

    2013-01-01

    Purpose We asked if retinal image quality is maximum during accommodation, or sub-optimal due to accommodative error, when subjects perform an acuity task. Methods Subjects viewed a monochromatic (552nm), high-contrast letter target placed at various viewing distances. Wavefront aberrations of the accommodating eye were measured near the endpoint of an acuity staircase paradigm. Refractive state, defined as the optimum target vergence for maximising retinal image quality, was computed by through-focus wavefront analysis to find the power of the virtual correcting lens that maximizes visual Strehl ratio. Results Despite changes in ocular aberrations and pupil size during binocular viewing, retinal image quality and visual acuity typically remain high for all target vergences. When accommodative errors lead to sub-optimal retinal image quality, acuity and measured image quality both decline. However, the effect of accommodation errors of on visual acuity are mitigated by pupillary constriction associated with accommodation and binocular convergence and also to binocular summation of dissimilar retinal image blur. Under monocular viewing conditions some subjects displayed significant accommodative lag that reduced visual performance, an effect that was exacerbated by pharmacological dilation of the pupil. Conclusions Spurious measurement of accommodative error can be avoided when the image quality metric used to determine refractive state is compatible with the focusing criteria used by the visual system to control accommodation. Real focusing errors of the accommodating eye do not necessarily produce a reliably measurable loss of image quality or clinically significant loss of visual performance, probably because of increased depth-of-focus due to pupil constriction. When retinal image quality is close to maximum achievable (given the eye’s higher-order aberrations), acuity is also near maximum. A combination of accommodative lag, reduced image quality, and reduced

  10. [Study on preferred retinal locus].

    PubMed

    Dai, Bing-Fa; Hu, Jian-Min; Xu, Duan-Lian

    2012-03-01

    Preferred retinal locus (PRL) is always found in the age-related macular degeneration and other macular damages in patients with low vision, and it is a very important anatomic position in patients with central vision impairment to achieve the rehabilitation. In recent years, the training of preferred retinal locus (PRL) has become a research hotspot of low vision rehabilitation, it can clearly improve functional vision and quality of life. The authors reviewed relevant literatures, and summarized the definition, position, characteristics, training and clinical implications of the PRL.

  11. Retinitis pigmentosa in southern Africa.

    PubMed

    Greenberg, J; Bartmann, L; Ramesar, R; Beighton, P

    1993-11-01

    Retinitis pigmentosa (RP) is a heterogeneous group of inherited retinal disorders which are a common cause of genetic blindness. The relative frequencies of the different forms of RP in South Africa, as determined from the register at the DNA banking centre for RP at the Department of Human Genetics, University of Cape Town, are presented and discussed. Of the 125 families analysed, 29 (23%) showed autosomal dominant, 33 (27%) autosomal recessive and 3 (3%) X-linked inheritance. In 10 families the pedigree data were insufficient to allow accurate genetic subtyping and a further 50 patients were sporadic without a family history of RP or other syndromic features which would allow categorization.

  12. Acute vascular abdomen. General outlook and algorithms.

    PubMed

    Miani, S; Boneschi, M; La Penna, A; Erba, M; De Monti, M; Giordanengo, F

    1999-09-01

    Acute vascular abdomen is a severe and life-threatening pathology due to arterial degeneration, leading to hemorrhage or arterial occlusion leading to ischemia. Differential diagnosis of patients with severe abdominal pain and/or shock include several vascular and traumatic diseases, the most common being rupture of abdominal aortic aneurysm (AAA), or less frequently rupture of visceral artery aneurysm. Also acute aortic dissection, iatrogenic injury and acute mesenteric ischemia may lead to acute vascular abdomen. Clinical evaluation of the haemodynamic status of the patient may be very difficult, and may require airway maintenance and ventilation with a rapid treatment of hemorrhagic shock. In the stable patient with an uncertain diagnosis, CT scan, NMR and selective angiography may be helpful in diagnosis before vascular repair. On the contrary, the unstable patient, after hemodynamic resuscitation, must be operated on expeditiously. We present our vascular algorithms, to assess timing of diagnosis and treatment of this severe acute disease.

  13. Non-Specific Inhibition of Ischemia- and Acidosis-Induced Intracellular Calcium Elevations and Membrane Currents by α-Phenyl-N-tert-butylnitrone, Butylated Hydroxytoluene and Trolox

    PubMed Central

    Katnik, Christopher; Cuevas, Javier

    2014-01-01

    Ischemia, and subsequent acidosis, induces neuronal death following brain injury. Oxidative stress is believed to be a key component of this neuronal degeneration. Acute chemical ischemia (azide in the absence of external glucose) and acidosis (external media buffered to pH 6.0) produce increases in intracellular calcium concentration ([Ca2+]i) and inward membrane currents in cultured rat cortical neurons. Two α-tocopherol analogues, trolox and butylated hydroxytoluene (BHT), and the spin trapping molecule α-Phenyl-N-tert-butylnitrone (PBN) were used to determine the role of free radicals in these responses. PBN and BHT inhibited the initial transient increases in [Ca2+]i, produced by ischemia, acidosis and acidic ischemia and increased steady state levels in response to acidosis and the acidic ischemia. BHT and PBN also potentiated the rate at which [Ca2+]i increased after the initial transients during acidic ischemia. Trolox inhibited peak and sustained increases in [Ca2+]i during ischemia. BHT inhibited ischemia induced initial inward currents and trolox inhibited initial inward currents activated by acidosis and acidic ischemia. Given the inconsistent results obtained using these antioxidants, it is unlikely their effects were due to elimination of free radicals. Instead, it appears these compounds have non-specific effects on the ion channels and exchangers responsible for these responses. PMID:24583849

  14. In-vivo confocal scanning laser ophthalmoscopic characterization of retinal pathology in a small-eye-animal model

    NASA Astrophysics Data System (ADS)

    Zwick, Harry; Elliot, Rowe; Schuschereba, Steven T.; Lund, David J.; Stuck, Bruce E.

    1997-05-01

    We have used confocal scanning laser ophthalmoscopy (CSLO) to evaluate acute laser retinal injury in a small eye animal model. THe snake eye is optically unique, combining a high numerical aperture with a clear ocular media and a cornea covered with a hard dry spectacle. These optical qualities allow detailed resolution of photoreceptors, retinal nerve fiber, and retinal capillary blood cells in an intact vertebrate eye. We demonstrated that acute laser exposures capable of damaging the photoreceptor matrix may also alter blood flow at more anterior levels of the retina. Changes in photoreceptor density and orientation were indicated in the early post exposure seconds at high dose acute Argon laser exposures. An increase in photoreceptor reflectivity was observed in surviving photoreceptors and was enhanced with a near IR CSLO imaging source. Q-switched exposure failed to show this enhancement, possibly because of greater subchoroidal involvement associated with acoustic damage processes.

  15. p66(ShcA) and oxidative stress modulate myogenic differentiation and skeletal muscle regeneration after hind limb ischemia.

    PubMed

    Zaccagnini, Germana; Martelli, Fabio; Magenta, Alessandra; Cencioni, Chiara; Fasanaro, Pasquale; Nicoletti, Carmine; Biglioli, Paolo; Pelicci, Pier Giuseppe; Capogrossi, Maurizio C

    2007-10-26

    Oxidative stress plays a pivotal role in ischemic injury, and p66(ShcA)ko mice exhibit both lower oxidative stress and decreased tissue damage following hind limb ischemia. Thus, it was investigated whether tissue regeneration following acute hind limb ischemia was altered in p66(ShcA)ko mice. Upon femoral artery dissection, muscle regeneration started earlier and was completed faster than in wild-type (WT) control. Moreover, faster regeneration was associated with decreased oxidative stress. Unlike ischemia, cardiotoxin injury induced similar skeletal muscle damage in both genotypes. However, p66(ShcA)ko mice regenerated faster, in agreement with the regenerative advantage upon ischemia. Since no difference between p66(ShcA)wt and knock-out (ko) mice was found in blood perfusion recovery after ischemia, satellite cells (SCs), a resident population of myogenic progenitors, were examined. Similar SCs numbers were present in WT and ko mice. However, in vitro cultured p66(ShcA)ko SCs displayed lower oxidative stress levels and higher proliferation rate and differentiated faster than WT. Furthermore, when exposed to sublethal H(2)O(2) doses, p66(ShcA)ko SCs were resistant to H(2)O(2)-induced inhibition of differentiation. Finally, myogenic conversion induced by MyoD overexpression was more efficient in p66(ShcA)ko fibroblasts compared with WT. The present work demonstrates that oxidative stress and p66(ShcA) play a crucial role in the regenerative pathways activated by acute ischemia.

  16. Fatal subarachnoid hemorrhage following ischemia in vertebrobasilar dolichoectasia

    PubMed Central

    Sokolov, Arseny A.; Husain, Shakir; Sztajzel, Roman; Croquelois, Alexandre; Lobrinus, Johannes A.; Thaler, David; Städler, Claudio; Hungerbühler, Hansjörg; Caso, Valeria; Rinkel, Gabriel J.; Michel, Patrik

    2016-01-01

    Abstract Vertebrobasilar dolichoectasia (VBD) is a chronic disorder with various cerebrovascular and compressive manifestations, involving subarachnoid hemorrhage (SAH). Occurrence of SAH shortly after worsening of clinical VBD symptoms has occasionally been reported. The goal of the study was to examine this association, in particular its pathophysiology, clinical precursor signs, time course, and outcome. To this end, in a retrospective multicenter study, we analyzed 20 patients with VBD and SAH in regard to preceding clinical symptoms, presence of vertebrobasilar thrombosis and ischemia, outcome and neuropathological correlates. Median age of the 7 female and 13 male patients was 70 years (interquartile range [IQR] 18.3 years). Fourteen patients (70%) presented with new or acutely worsening posterior fossa signs at a median of 3 days prior to SAH (IQR 2, range 0.5–14). A thrombus within the VBD was detected in 12 patients (60%). Thrombus formation was associated with clinical deterioration (χ2 = 4.38, P = 0.04) and ponto-cerebellar ischemia (χ2 = 8.09, P = 0.005). During follow-up after SAH, 13 patients (65%) died, after a median survival time of 24 hours (IQR 66.2, range 2–264 hours), with a significant association between proven ponto-cerebellar ischemia and case fatality (χ2 = 6.24, P = 0.01). The data establish an association between clinical deterioration in patients with VBD, vertebrobasilar ischemia, and subsequent SAH. Antithrombotic treatment after deterioration appears controversial and SAH outcome is frequently fatal. Our data also indicate a short window of 3 days that may allow for evaluating interventional treatment, preferably within randomized trials. PMID:27399083

  17. Digital tracking and control of retinal images

    NASA Astrophysics Data System (ADS)

    Barrett, Steven F.; Jerath, Maya R.; Rylander, Henry G.; Welch, Ashley J.

    1994-01-01

    Laser-induced retinal lesions are used to treat a variety of eye disorders such as diabetic retinopathy and retinal tears. An instrumentation system has been developed to track a specific lesion coordinate on the retinal surface and provide corrective signals to maintain laser position on the coordinate. High-resolution retinal images are acquired via a CCD camera coupled to a fundus camera and video frame grabber. Optical filtering and histogram modification are used to enhance the retinal vessel network against the lighter retinal background. Six distinct retinal landmarks are tracked on the high contrast image obtained from the frame grabber using 2D blood vessel templates. An overview of the robotic laser system design is followed by implementation and testing of a development system for proof of concept and, finally, specifications for a real-time system are provided.

  18. Non-contact ultra-widefield retinal imaging of infants with suspected abusive head trauma.

    PubMed

    Yusuf, I H; Barnes, J K; Fung, T H M; Elston, J S; Patel, C K

    2017-03-01

    PurposeThe purpose of the study was to audit the use of non-contact ultra-widefield retinal imaging in infants with suspected abusive head trauma (AHT) using the Optos P200MA Scanning Laser Ophthalmoscope.Patients and methodsA retrospective, observational case series. Ten eyes of five consecutive infants (aged 1-15 months) with suspected (or in 1 case, known) AHT referred for an ophthalmological opinion were included. Each infant underwent non-contact ultra-widefield retinal imaging using the Optos P200MA scanning laser ophthalmoscope. Optos fundus fluorescein angiography (FFA) was performed in one infant with oral sedation. The other four infants did not require sedation. The main outcome measure was the acquisition of a single, definitive ultra-widefield retinal image in each eye. Safety was audited by determining adverse changes in heart rate and oxygen saturations that required cessation of imaging.ResultsThe Optos P200MA ultra-widefield scanning laser ophthalmoscope acquired good quality retinal images in all infants. Documentation of acute, widespread retinal haemorrhages contributed to a diagnosis of AHT in three infants. Chronic pre-macular haemorrhage and macular schisis were documented by FFA in a fourth infant. The absence of retinal haemorrhages was documented in a fifth infant contributing to the exclusion of a diagnosis of AHT. There were no adverse safety signals in any infant in this series.ConclusionThe Optos P200MA ultra-widefield scanning laser ophthalmoscope appears safe to use in infants with suspected AHT, providing high-quality retinal images in a single frame without ocular contact. Optos P200MA may be used as alternative to RetCam to document retinal haemorrhages in stable infants with suspected AHT.

  19. Optical coherence tomography angiography microvascular findings in macular edema due to central and branch retinal vein occlusions

    PubMed Central

    Rodolfo, Mastropasqua; Lisa, Toto; Luca, Di Antonio; Enrico, Borrelli; Alfonso, Senatore; Marta, Di Nicola; Giuseppe, Di Martino; Marco, Ciancaglini; Carpineto, Paolo

    2017-01-01

    The aim of this study was to evaluate retinal and choriocapillaris vessel density using optical coherence tomography angiography (OCTA) in eyes with central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO) complicated by macular edema (ME). Sixty eyes of 60 patients with CRVO or BRVO and ME and 40 healthy subjects underwent measurements of superficial and deep foveal and parafoveal vessel density (FVD, PFVD) and choricapillary density using OCTA at baseline and 60 days after intravitreal dexamethasone implant (IVDEX). FVD and PFVD of the superficial plexus were not significantly lower in CRVO group compared to the controls while in the BRVO group overall PFVD were significantly lower compared to control group (p < 0.001). Overall PFVD of the deep plexus was significantly lower in CRVO and BRVO groups compared to the control group (p < 0.001). FVD and overall PFVD of choriocapillaris were significantly reduced compared to controls in CRVO group (p < 0.001) and PFVD of choriocapillaris was significantly reduced compared to controls in the affected hemi fields in BRVO groups (p < 0.001). OCTA showed vessel density reduction in BRVO and CRVO with main involvement of the deep retinal plexus compared to the superficial retinal plexus due to ischemia that did not recover after intravitreal dexamethasone implant. PMID:28098203

  20. Automatic temperature controlled retinal photocoagulation

    NASA Astrophysics Data System (ADS)

    Schlott, Kerstin; Koinzer, Stefan; Ptaszynski, Lars; Bever, Marco; Baade, Alex; Roider, Johann; Birngruber, Reginald; Brinkmann, Ralf

    2012-06-01

    Laser coagulation is a treatment method for many retinal diseases. Due to variations in fundus pigmentation and light scattering inside the eye globe, different lesion strengths are often achieved. The aim of this work is to realize an automatic feedback algorithm to generate desired lesion strengths by controlling the retinal temperature increase with the irradiation time. Optoacoustics afford non-invasive retinal temperature monitoring during laser treatment. A 75 ns/523 nm Q-switched Nd:YLF laser was used to excite the temperature-dependent pressure amplitudes, which were detected at the cornea by an ultrasonic transducer embedded in a contact lens. A 532 nm continuous wave Nd:YAG laser served for photocoagulation. The ED50 temperatures, for wh