Purpose: Ischemic preconditioning (IPC) has been used to protect myocardial cells against ischemia-reperfusion injury and is recently used for improving exercise performance. It is unknown whether a remote bout of IPC (RIPC) to tissue not involved in exercise can induce similar exercise improvements and what “dose” of IPC is necessary to induce exercise performance benefits. This study determined if unilateral and bilateral upper limb RIPC improves lower body anaerobic power output. Methods: Using two randomized, single blind, crossover study designs, we studied 43 young recreationally active adults. For study 1, unilateral RIPC was used and a sham control condition involved the inflation of blood pressure cuffs to 10 mm Hg. For study 2, the ischemic stimuli were increased to bilateral occlusion while the sham control condition used was 0 mm Hg of occlusion pressure. After the RIPC treatment, subjects completed four 30 s Wingate anaerobic tests on a Monark cycle ergometer with 2 min passive rest between trials. Results: In the unilateral occlusion trial, peak power, mean power, and fatigue index were not different between the two conditions at every Wingate test. In the bilateral occlusion trial, peak power was elevated in the RIPC condition than in the sham control for the fourth Wingate test (p<0.05). Additionally, compared with the sham control, mean power was greater in the RIPC condition during the first and fourth Wingate tests (both p<0.05). Conclusion: Remote ischemic preconditioning applied bilaterally increased lower body power output over a series of Wingate anaerobic tests. Unilateral RIPC, however, had no effect on any of the performance variables, suggesting that there is a threshold for the amount of target tissue needed to elicit anaerobic performance benefits. / text

Abstract Stroke is a potentially lethal cerebrovascular event. Many research studies devoted to the treatment of stroke. In a recent study, sphingosine-1-phosphate (S1P) has the function of reducing the brain infarct volume. However, no study has yet demonstrated that lysophosphatidic acid (LPA) has this function. LPA and S1P are thought to be the two functionally important LPLs with high structural similarity. Although the neuroprotective function of S1P in TIA rat was confirmed, the effects of LPA on the brain damage after ischemic stroke of animal remain unclear. In this study we evaluated the neuroprotective effects of LPA1/3 receptor agonist (VPC31143; VPC) on rat brains subjecting to permanent middle cerebral artery occlusion (PMCAO). A reliable surgical model of rat PMCAO was first established. Thereafter, the animals were divided into control, vehicle, high-dose VPC, and low-dose VPC groups. The vehicle group received intraperitoneal (i.p.) injection of 3% bovine serum albumin (BSA; 1 ml/kg) 30 minutes after PMCAO surgery. The high-dose VPC and the low-dose VPC group respectively received 0.8 mg/kg and 0.25 mg/kg of i.p. injection of VPC (in 3% BSA) 30 minutes after PMCAO surgery. The mortality rate, infarct volume ratio, and the neurobehavioral outcome were measured 24 hours after PMCAO and statistically analyzed for the difference between treatments. Analyses of the experimental results showed that VPC treatment significantly reduced the mortality rate and the infarct volume ratio of the rats 24 hours after PMCAO. The neurobehavioral scores also showed the improved outcome in stroke rats treated with VPC. The beneficial effect of VPC to the ischemic brain was thought to be mediated through the PI3K signal transduction pathway. Further studies at the transcriptional and the translational levels will further confirm this postulation.

AN ABSTRACT OF THE THESIS OF Elizabeth Dawn Grisley, for the Master’s degree in Cellular and Molecular Systemic Physiology, presented on November 6th, 2015, at Southern Illinois University Carbondale. TITLE: INFLUENCE OF DIET AND STROKE ON EXPRESSION OF GENES THAT MODULATE INFLAMMATION AND NEURONAL REMODELING IN THE ADULT AND AGED MALE RAT CEREBRAL CORTEX MAJOR PROFESSOR: Dr. Joseph L. Cheatwood Nearly 800,000 Americans are stricken by ischemic stroke each year. Other than care with post stroke rehabilitation there are no specific treatments for improving functional recovery. To improve the recovery of stroke patients we are investigating anti-inflammatory, anti-apoptotic, and neuronal remodeling pathways. Estrogen receptor activators are known to be neuroprotective by initiating pathways through ERβ and ERα. The bioactive soy isoflavones, daidzein and genistein, do bind to these estrogen receptors. However, this binding alone is not sufficient to explain the ability of soy-based diets and purified isoflavones to reduce inflammation and improve neuroprotection and recovery after stroke. Herein, we focused on the Pparg, Arg-1, 14-3-3ε, Sirt1, Gap43, Synaptophysin, Sod-1, Bcl-xl, Bcl-2, and the Rtn4(Nogo-A) pathways to test the hypothesis that diets containing soy isoflavones and/or soy protein isolate will reduce inflammation and promote the expression of neuronal plasticity markers following stroke in adult and aged rats via these mechanisms. Adult and aged male Hooded Long Evans rats were fed a semi-purified diet of either 1) sodium caseinate (CAS), 2) sodium caseinate plus the isoflavones daidzein and genistein (CAS+ISO), or 3) soy protein isolate (SPI) for two weeks prior to middle cerebral artery occlusion (MCAO). Permanent unilateral MCAO was performed and tissue was collected from both hemispheres at Day 0 (no stroke) and Day +3. Rats were maintained on their assigned diet throughout the experiment. RNA was extracted and cDNA synthesized for qPCR reaction. All data were normalized to Gapdh via the ΔΔCt method. qPCR analyses of the contralateral and ipsilateral brain tissue at 3 days after stroke resulted in upregulation of Sod-1, Sirt1, 14-3-3ε, Bcl-xl, Bcl-2, Gap43, Syp and Rtn4(Nogo-A) mRNA expression in the contralateral hemisphere. Only Pparg and Arg1 mRNA were found to be upregulated in the ipsilateral hemisphere. Through the upregulation of Pparg mRNA expression in the ipsilateral cortex we have established that the anti-inflammatory pathway is being initiated in our model. However it has been activated by a greater degree with the SPI treatment not the isoflavones daidzein and genistein alone as previously thought. It is unclear if the daidzein and genistein are working concurrently with one or more of the compounds found in the SPI treatment or if one or more additional compounds in the SPI has been the true activator. Since the tissue analyzed in this project was from animals that exhibited significant post stroke behavioral outcomes in a previous experiment we believed the influence of compensatory sprouting from the contralesional hemisphere was modulating the improvement of growth and anti-inflammatory factors to the injured ipsilateral hemisphere. Extensive research is still needed to confirm the source of activation in the PPARG pathway with the SPI treatment, the time and age points that transcriptional expression of our selected genes will activate or influence translational and/or post-translational effects and how the ischemic hemisphere is benefitting from compensatory sprouting from the contralateral hemisphere in this ischemic stroke model. By continuing in the directions mentioned above the mechanism by which isoflavones significantly improve post-stroke behavioral outcomes may be revealed.

Remote ischemic conditioning (RIC) is a noninvasive procedure where blood flow to a limb is repetitively reduced, sometimes called an “exercise memetic”. RIC delivered before (pre-RIC) or after (post-RIC) stroke is reportedly neuroprotective in preclinical stroke models. A review of the preclinical RIC literature revealed that studies almost exclusively use male subjects and a single stroke model (MCAO) that produces a large injury (~34% of hemisphere). To improve clinical translation, efficacy should be demonstrated in multiple stroke models and both sexes. Furthermore, the restorative potential of RIC (delivered past the neuroprotection window) to improve stroke recovery remains to be investigated. In male and female Sprague-Dawley rats (n=129) a standardized session (5min inflation, 5min deflation, 4 repetitions) of RIC was delivered using a pressurized cuff on the hindlimb. RIC was either delivered once 18h before, once 4hr acutely after or daily for 28 days beginning day 5 after endothelin-1 (ET-1) stroke. Infarct volumes were assessed 24hrs after stroke using MRI. To determine if RIC efficacy varied across stroke size, a hierarchical cluster analysis was used to divide rats into subgroups based on stroke size (small/large). RIC was effective in ET-1 which produced smaller strokes (“small”:5.2%, “large”:18.0% of hemisphere) than MCAO (~34%). This is more comparable to injury sizes seen clinically (4.5-14.0%). “Small” (42±4mm3) strokes were reduced by 39% (p=0.010, d=0.29) and “large” (146±8mm3) strokes were reduced by and 35% (p<.00001, d=1.41). Pre-RIC reduced infarct volume by 41% (p=<0.0001, d=0.92) versus 29% (p=0.009, d=0.43) in post-RIC. Interestingly, RIC is more effective in males, with double the infarct volume reduction of 46% (p<0.0001, d=0.94) compared with 23% (p=0.013, d=0.42) in females. Although RIC did not show restorative potential to improve motor stroke recovery, RIC is neuroprotective now with stronger clinically relevant evidence. RIC is effective across stroke models, stroke sizes and sex. Application of RIpreC to prevent stroke following a transient ischemic attack or recurrent stroke (especially in males with “large" strokes) would have the greatest potential.

The latest evidence indicates that 50,000 Canadians will experience a stroke in 2013. The hospital care, rehabilitation, and long term care associated with a stroke places a significant burden on our health care system. Lost productivity and premature death have an immeasurable impact on communities in our province as well as the rest of the country. Small, less populated regions such as Saskatchewan may be underrepresented in national data utilized in the development of national prevention and treatment strategies across the country. The absence of local research has necessitated the use of national information to guide prevention, treatment education and programming in Saskatchewan. The goals of this study was to provide a descriptive profile of stroke and transient ischemic attack cases admitted to Royal University Hospital over the period of April 1, 2009 to March 31st, 2010 and to assess the acute management of these cases as defined in the Canadian Best Practice Recommendations for Stroke Care (Strategy, 2010). A randomized sample of 200 cases 55 years and older was selected for a retrospective descriptive study involving review of adult stroke case records. Personal demographics and healthcare performance through the use of measures provided in The Canadian Best Practice Recommendations for Stroke Care (Canadian Stroke Network (CSN) and Heart and Stroke Foundation of Canada (HSFC), 2010) were evaluated. The results indicated many similarities to available national information on type of stroke, risk factors, gender, and age. Hospital adherence to national guidelines comparing selected indicators was exceeded in some areas, and met in most. The remaining indicators provide an opportunity for improvement and possibly more research. This regional information supplements the available Canadian information and could be used to guide planning and care strategically targeting Saskatchewan residents and increasing their potential for success.

The latest evidence indicates that 50,000 Canadians will experience a stroke in 2013. The hospital care, rehabilitation, and long term care associated with a stroke places a significant burden on our health care system. Lost productivity and premature death have an immeasurable impact on communities in our province as well as the rest of the country. Small, less populated regions such as Saskatchewan may be underrepresented in national data utilized in the development of national prevention and treatment strategies across the country. The absence of local research has necessitated the use of national information to guide prevention, treatment education and programming in Saskatchewan. The goals of this study was to provide a descriptive profile of stroke and transient ischemic attack cases admitted to Royal University Hospital over the period of April 1, 2009 to March 31st, 2010 and to assess the acute management of these cases as defined in the Canadian Best Practice Recommendations for Stroke Care (Strategy, 2010). A randomized sample of 200 cases 55 years and older was selected for a retrospective descriptive study involving review of adult stroke case records. Personal demographics and healthcare performance through the use of measures provided in The Canadian Best Practice Recommendations for Stroke Care (Canadian Stroke Network (CSN) and Heart and Stroke Foundation of Canada (HSFC), 2010) were evaluated. The results indicated many similarities to available national information on type of stroke, risk factors, gender, and age. Hospital adherence to national guidelines comparing selected indicators was exceeded in some areas, and met in most. The remaining indicators provide an opportunity for improvement and possibly more research. This regional information supplements the available Canadian information and could be used to guide planning and care strategically targeting Saskatchewan residents and increasing their potential for success.

Although adenosine receptors have been implicated in the induction of preconditioning in a variety of experimental models, there is controversy concerning the specific adenosine receptor subtypes mediating this effect. Concentration-protection relationships for adenosine and adenosine agonists in rabbit cardiomyocytes were used to characterize the role of adenosine receptor subtypes in preconditioning. Isolated cells were ischemically preconditioned or pre-incubated for 10 min with increasing concentrations of adenosine, CCPA (2-chloro-N6-cyclopentyladenosine) APNEA (N6-2-(4-aminophenyl)ethyladenosine), or BNECA (N6-benzyl-5'-N-ethyl-carboxamidoadenosine) in the presence or absence of 1 or 10 μM of the selective A1-adenosine antagonist DPCPX (8-Cyclopentyl-1,3-dipropylxanthine). Following a 30-min post-incubation period, cells were pelleted, layered with oil and ischemically incubated for 180 min. Injury was assessed by osmotic swelling and trypan blue exclusion of sequential samples, and determination of the areas beneath the mortality curves. Adenosine produced a broad concentration-protection curve which was displaced to the right by DPCPX. The curve for A1-selective agonist CCPA was biphasic, with an initial response below 1 nM and a second above 1 μM. DPCPX abolished the early response leaving a steep monophasic curve between 0.1 and 10 μM CCPA. The APNEA curve appeared monophasic, the major slope occurring between 1-100 nM; DPCPX (1 μM) shifted the concentration-response curve ≃ 30-fold and decreased the slope. Adenosine receptor agonist BNECA produced preconditioning characterized by a shallow monophasic concentration-protection curve with a maximal effect of 49% and an EC50 of ≃ 5 nM; DPCPX shifted the BNECA concentration-protection relationship ≃ 40-fold with only a modest increase in slope. Analysis of the data suggests that induction of preconditioning results from interaction of agonists with the A1 receptor and a second adenosine receptor having properties consistent with the A3 receptor. Adenosine, CCPA, APNEA, BNECA and DPCPX each appear to be selective for the A1 adenosine receptor subtype in isolated rabbit cardiomyocytes.

lschemic disease in form of ischemic heart disease (IHD), ischemic stroke and peripheral arterial disease (PAD) due to atherosclerosis represents a massive clinical and economic burden to healthcare and is currently the number one cause of death in the world. Treatment modalities for peripheral arterial disease include bypass surgery involving autologous vein or synthetic materials such as ePTFE. Long term patency of small diameter vascular grafts used for infra-inguinal reconstructions, however, is below 50 % 5 years after implantation. Therefore, novel vascular graft concepts and materials are needed. The concept of transmural in vivo endothelialisation of vascular grafts holds great promise for increasing long term patency. To achieve complete luminal endothelial cell coverage and optimal integration of the porous synthetic graft material into the host tissue, transmural ingrowth of tissue and vasa vasorum might have to be facilitated. Since VEGF1ss and PDGF-BB are growth factors known to stimulate and consolidate angiogenesis, this PhD thesis hypothesized, that neovascularisation of porous polyurethane (PU) can be increased by delivery of vascular endothelial growth factor (VEGF1ss) and platelet derived growth factor (PDGF-BB). To prove this hypothesis, subcutaneous implantation of PU discs was established as a valid, reproducible, relatively simple and quantifiable neovascularisation model. Three different ways of growth factor delivery were investigated. The gene encoding for human VEGF15s was cloned into the genome of adeno associated viruses (AAV), which served as a vector for gene transduction of autologous wound healing cells in vivo using the "Gene Activated Matrix" approach. Genetically modified matrix embedded AAV-VEGF155 was loaded into porous PU and transduced autologous ingrowing wound cells. In contrast to the excellent transduction efficiency in myocytes, AA V showed a poor tropism for wound healing cells. The second approach to increase neovascularisation into porous PU was the surface modification of PU by covalent attachment of nitrous acid degraded heparin. Neovascularisation into the biomaterial was increased by 77 % after 10 days of subcutaneous implantation. Since certain angiogenic growth factors show a high affinity for heparin, additional loading of heparin surface modified PU with VEGF165 increased neovascularisation even further up to 115 % at 10 days compared to control. Dual growth factor delivery of VEGF 165 and PDGF-BB not only initiated increased vascularisation of porous PU, but also created a stable vascular network 2 months after implantation. In contrast, PU loaded with VEGF165 alone showed regression of total vascular area of 61 % compared to vascular area at 10 days. Thirdly, to study the effects of controlled, prolonged growth factor delivery, a "Neovascularisation Construct" was developed which was implanted subcutaneously in rats. The construct consisted of an osmotic mini pump and a tube of porous PU lined with ePTFE, into which a defined amount of VEGF16s was pumped for 10 days. After implantation, granulation tissue was growing into the pores of the PU and neovascular area was increased up to 265 % compared to PBS control. Furthermore, using different growth factor concentration, a dose dependency was shown. In addition, this thesis investigated the functional perfusion of the micro vascular network growing into PU by four different vascular quantification techniques. lntravital perfusion with biotinylated lycopersicon esculentum followed by microscopical analysis, vascular corrosion casting quantified by scanning electron microscopy as well as the novel micro-CT analysis of silicone rubber perfused vessels were compared to conventional immunhistochemical analysis of endothelial cells by CD31. Interestingly, PBS perfused "Neovascularisation Constructs" showed a relatively poor perfusion; therefore CD31 immunohistochemistry "overestimated" functional neovascularisation 3 fold. All perfusion techniques indicated a strong effect of VEGF 165 delivery on vessel perfusion (10 to 20 fold increases of vascular area and volume compared to PBS control). Micro-CT scanning was shown to be an excellent tool to study micro vascular networks in a three-dimensional fashion across the whole length of the sample in a limited amount of time and to provide reliable and reproducible data on vessel density, vascular volume, and connectivity. Since resolution is still limited today to about 10 μm using a commercially available bench top scanner, this new technology still needs to be complemented by immunohistochemistry and perfusion studies such as lectin perfusion and corrosion casting. In summary, the induction of neovascularisation was achieved by heparin surface modification alone, which was even increased through additional delivery of growth factors into the biomaterial PU. The development of a stable micro vascular network at 2 months was achieved and the functionality was shown using four different, independent techniques including the novel micro-CT scanning of neovascularisation into biomaterials. Towards the development of an in vivo, spontaneously and transmurally endothelialising vascular graft with superior long-term patency further investigations are necessary. As an initial step, increased spontaneous neovascularisation of the possible graft material polyurethane was achieved. Future steps are clearly indicated to study the translation of increased neovascularisation of the biomaterial polyurethane towards increased endothelialisation in a vascular graft model.

No description available.

The purpose of this study was to gain understanding of the early symptom experience of ischemic stroke in women. This is the only study of which the researcher is aware in which narrative inquiry was used to examine the period of time from symptom onset until emergency department arrival in women. Data collection was achieved by in-depth interviews during which participants’ stories of stroke were elicited. Individual narrative accounts were created and analyzed using within and across case techniques. The participants were nine women ranging in age from 24-86 years (average age 53). Four participants were Caucasian, three were Hispanic, one was African American and one woman was of mixed race. The participants experienced the onset of stroke as the inability to carry out accustomed activities in usual ways. There was a tendency to objectify the body. Only two participants considered stroke as a possible cause for their symptoms, and the other women attributed symptoms everyday bodily experiences and/or other health conditions. Most participants did not perceive themselves at risk for stroke although all but one woman had risk factors. The participants displayed a variety of responses to symptoms, including trying to continue with usual activities and seeking help as well as deciding not to tell anyone about their symptoms. Symptom response was related to women’s evaluation of and emotional response to symptoms. The actions taken by the participants in response to symptoms were informed by the meaning of the symptoms, and meaning was formed within the context of each woman’s life situation. Few women made the decision to seek medical care on their own, and in every case family members or co-workers were reported to take an active role in getting the participant to the hospital. Some family members were reported to consult with one another before making the decision to call EMS or transporting the participant to the emergency department. Consistent with what was expected from extant research the majority of the participants did not arrive at the hospital in time to be offered treatment with t-PA. Recommendations for future research, stroke education and practice were discussed. / text