The goal of this study was to determine whether targeted, Rhodamine-labeled echogenic liposomes (Rh-ELIP) containing nanobubbles could be delivered to the arterial wall, and whether 1 MHz continuous wave ultrasound would enhance this delivery profile. Aortae excised from apolipoprotein-E-deficient (n = 8) and wild-type (n = 8) mice were mounted in a pulsatile flow system through which Rh-ELIP were delivered in a stream of bovine serum albumin. Half the aortae from each group were treated with 1-MHz continuous wave ultrasound at 0.49 MPa peak-to-peak pressure, and half underwent sham exposure. Ultrasound parameters were chosen to promote stable cavitation and avoid inertial cavitation. A broadband hydrophone was used to monitor cavitation activity. After treatment, aortic sections were prepared for histology and analyzed by an individual blinded to treatment conditions. Delivery of Rh-ELIP to the vascular endothelium was observed, and subendothelial penetration of Rh-ELIP was present in five of five ultrasound-treated aortae and was absent in those not exposed to ultrasound. However, the degree of penetration in the ultrasoundexposed aortae was variable. There was no evidence of ultrasound-mediated tissue damage in any specimen. Ultrasound-enhanced delivery within the arterial wall was demonstrated in this novel model, which allows quantitative evaluation of therapeutic delivery.

Objective-Worldwide, cerebral vasospasm after subarachnoid hemorrhage (SAH) has an estimated morbidity and mortality of 1.2 million annually. While it has long been suspected that reactive oxygen species play a major role in the etiology of cerebral vasospasm after SAH, promising results in animal works were not borne out in human clinical trials, despite intensive research effort. The purpose of this study is to investigate the role of glutathione peroxidase in the SAH cerebrospinal fluid milieu.Methods-We utilized commercially available kits, for the quantitation of glutathione peroxidase 1 (glutathione peroxidase) activity and oxygen radical capacity and sodium dodecyl sulfate polyacrylamide gel electrophoresis with Western blotting with specific antibodies to human glutathione peroxidase to determine the enzyme content of the cerebrospinal fluid samples. Human cerebrospinal fluid was obtained in an Institutional Review Board-exempt manner for this study in the following groups: control (no SAH), CSF C (SAH but no vasospasm on angiography) and CSF V (SAH with clinical and angiographic vasospasm).Results-We found that glutathione peroxidase activity is significantly higher in CSF V compared with CSF C , and this is reflected in a higher total oxidative capacity in CSF V . Despite similar levels of glutathione peroxidase protein, CSF V had significantly greater activity than CSF C .Discussion-These results further elucidate previous research from this laboratory, showing increased oxidative stress in CSF V compared with CSF C . In conclusion, there appears to be increased glutathione peroxidase activity in CSF V , despite there being increased levels of oxidative stress markers, suggesting overwhelming oxidative stress may play a role in cerebral vasospasm after SAH.

Cerebral vasospasm (CV) remains a significant cause of delayed neurological deficit and ischemic damage after subarachnoid hemorrhage (SAH), despite intensive research effort. The current lack of an effective therapeutic approach is somewhat due to our lack of understanding regarding the mechanism by which this pathological constriction develops. Recent evidence implicates bilirubin oxidation products (BOXes) in the etiology of CV after SAH: BOXes are found in cerebrospinal fluid from SAH patients with symptomatic or angiographically visible vasospasm (CSF V ) but not in CSF from SAH patients with no vasospasm (CSF C ). We have previously published research suggesting that the etiology of CV comprises two components: a physiological stimulation to constrict and a pathological failure to relax. Both these components are elicited by CSF V , but not CSF C , and BOXes synthesized in the laboratory potentiate physiological constriction in arterial smooth muscle in vitro, and elicit contraction in pial arteries in vivo. In this paper, we will present our results concerning the action of BOXes on arterial smooth muscle constriction, compared with CSF V . We will also present evidence implicating temporal changes in PKC isoforms and Rho expression in both BOXes-and CSF V -elicited smooth muscle responses. Keywords INTRODUCTIONWorldwide, subarachnoid hemorrhage (SAH) and its sequel, cerebral vasospasm (CV), kill or seriously debilitate an estimated 1.2 million people, of both genders, and all ages and ethnic groups annually (1). In the United States alone, complications from SAH, including increased length of hospital stay, increased treatment intensity level, requirement for long-term care and intensive rehabilitation are estimated to have cost 500 million dollars in 2000 (2). The pathological constriction of cerebral vessels that occurs during CV may lead to ischemia, infarction or death (3,4) and the 3-10 days between the initial hemorrhage and onset of CV potentially affords the clinician a therapeutic window (5). Unfortunately, despite considerable research efforts, the etiology of CV is still unknown, and appears to be a complex combination of events (3,6-10) Our research indicates that the intractable vasoconstriction seen in CV after SAH is a combination of a physiological protein kinase C-mediated contraction, followed by a pathological failure to relax, mediated by Rho-mediated inhibition of myosin light chain Send correspondence to: Dr Gail Pyne-Geithman, Department of Neurology, University of Cincinnati, 2324 Vontz Center, 3125 Eden Avenue, Cincinnati, OH USA NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript phosphatase (9,11). Bilirubin oxidation products (BOXes) may be responsible for one or both of these events (12-14).The literature records a bewildering array of molecules that may be implicated in the etiology of CV after SAH. They include endothelin (15), hemoglobin (7,16), bilirubin and it's oxidation products (17-19), arachidonic acid and it's peroxidized metabolites...

Introduction-Cerebral vasospasm after subarachnoid hemorrhage (SAH) is a serious complication resulting in delayed neurological deficit, increased morbidity, mortality, longer hospital stays, and rehabilitation time. It afflicts approximately 35 per 100,000 Americans per year, and there is currently no effective therapy. We present in vitro data suggesting that increasing intrinsic nitric oxide relaxation pathways in vascular smooth muscle via dopaminergic agonism ameliorates cerebral vasospasm after SAH.

In this model, alfimeprase, a new fibrinolytic agent, exhibits a profile comparable to recombinant tissue plasminogen activator.