Four-year overall survival update from the phase III HIMALAYA study of tremelimumab plus durvalumab in unresectable hepatocellular carcinoma

BACKGROUND

In the phase III HIMALAYA study (NCT03298451) in unresectable hepatocellular carcinoma (uHCC), STRIDE (Single Tremelimumab Regular Interval Durvalumab) significantly improved overall survival (OS) versus sorafenib; durvalumab monotherapy was noninferior to sorafenib for OS. Results reported herein are from a 4-year updated OS analysis of HIMALAYA.

PATIENTS AND METHODS

Participants with uHCC and no previous systemic treatment were randomized to STRIDE (n = 393), durvalumab (n = 389), or sorafenib (n = 389). The updated data cut-off was 23 January 2023. OS and serious adverse events (AEs) were assessed. Additionally, baseline characteristics and subsequent therapies were analyzed in long-term survivors (≥36 months beyond randomization).

RESULTS

For STRIDE, durvalumab, and sorafenib, median [95% confidence interval (CI)] follow-up was 49.12 months (46.95-50.17 months), 48.46 months (46.82-49.81 months), and 47.31 months (45.08-49.15 months), respectively. OS hazard ratio (95% CI) for STRIDE versus sorafenib was 0.78 (0.67-0.92). The 36-month OS rate for STRIDE was 30.7% versus 19.8% for sorafenib. The 48-month OS rate remained higher for STRIDE at 25.2%, versus 15.1% for sorafenib. The long-term OS benefit of STRIDE was observed across clinically relevant subgroups and was further improved in participants who achieved disease control. Long-term survivors with STRIDE (n = 103) included participants across clinically relevant subgroups, and 57.3% (59/103) had no reported subsequent anticancer therapy. No new serious treatment-related AEs occurred with STRIDE from the primary analysis (17.5%; 68/388). Durvalumab maintained OS noninferiority to sorafenib and no late-onset safety signals were identified.

CONCLUSIONS

These data represent the longest follow-up to date in phase III studies in uHCC. The unprecedented 3- and 4-year OS rates reinforce the sustained long-term OS benefit of STRIDE versus sorafenib. STRIDE maintained a tolerable yet differentiated safety profile from other current uHCC therapies. Results continue to support the long-term benefits of STRIDE in a diverse population, reflective of uHCC globally.

Hong Kong consensus recommendations on the management of pancreatic ductal adenocarcinoma

This project was undertaken to develop the first set of consensus statements regarding the management of pancreatic ductal adenocarcinoma (PDAC) in Hong Kong, with the goal of providing guidance to local clinicians. A multidisciplinary panel of experts discussed issues surrounding current PDAC management and reviewed evidence gathered in the local context to propose treatment recommendations. The experts used the Delphi approach to finalise management recommendations. Consensus was defined as ≥80% acceptance among all expert panel members. Thirty-nine consensus statements were established. These statements cover all aspects of PDAC management, including diagnosis, resectability criteria, treatment modalities according to resectability, personalised management based on molecular profiling, palliative care, and supportive care. This project fulfils the need for guidance regarding PDAC management in Hong Kong. To assist clinicians with treatment decisions based on varying levels of evidence and clinical experience, treatment options are listed in several consensus statements.

A 3D biomimetic model of lymphatics reveals cell-cell junction tightening and lymphedema via a cytokine-induced ROCK2/JAM-A complex

Impaired lymphatic drainage and lymphedema are major morbidities whose mechanisms have remained obscure. To study lymphatic drainage and its impairment, we engineered a microfluidic culture model of lymphatic vessels draining interstitial fluid. This lymphatic drainage-on-chip revealed that inflammatory cytokines that are known to disrupt blood vessel junctions instead tightened lymphatic cell-cell junctions and impeded lymphatic drainage. This opposing response was further demonstrated when inhibition of rho-associated protein kinase (ROCK) was found to normalize fluid drainage under cytokine challenge by simultaneously loosening lymphatic junctions and tightening blood vessel junctions. Studies also revealed a previously undescribed shift in ROCK isoforms in lymphatic endothelial cells, wherein a ROCK2/junctional adhesion molecule-A (JAM-A) complex emerges that is responsible for the cytokine-induced lymphatic junction zippering. To validate these in vitro findings, we further demonstrated in a genetic mouse model that lymphatic-specific knockout of ROCK2 reversed lymphedema in vivo. These studies provide a unique platform to generate interstitial fluid pressure and measure the drainage of interstitial fluid into lymphatics and reveal a previously unappreciated ROCK2-mediated mechanism in regulating lymphatic drainage.

Risks and impacts of thromboembolism in patients with pancreatic cancer

INTRODUCTION

Patients with pancreatic cancer have a high risk of thromboembolism (TE), which may increase mortality. Most relevant studies have been conducted in Western populations. We investigated risk factors for TE in a predominantly Chinese population of patients with pancreatic cancer, along with effects of TE on overall survival.

METHODS

This retrospective cohort study included patients diagnosed with exocrine pancreatic cancer in Prince of Wales Hospital in Hong Kong between 2010 and 2015. Data regarding patient demographics, World Health Organization performance status, stage, treatment, TE-related information, and time of death (if applicable) were retrieved from electronic medical records. Univariate and multivariable logistic regression analyses were performed to identify risk factors for TE. Survival analyses were performed using Kaplan-Meier analysis and Cox proportional hazards regression.

RESULTS

In total, 365 patients were included in the study. The overall incidence of TE (14.8%) was lower than in Western populations. In univariate logistic regression analysis, stage IV disease and non-head pancreatic cancer were significantly associated with TE (both P=0.01). Multivariable logistic regression analysis showed that stage IV disease was a significant risk factor (odds ratio=1.08, 95% confidence interval [CI]=1.00-1.17; P=0.046). Median overall survival did not significantly differ between patients with and without TE (4.88 months vs 7.80 months, hazard ratio=1.08, 95% CI=0.80-1.49; P=0.58) and between patients with TE who received anticoagulation treatment or not (5.63 months vs 4.77 months, hazard ratio=0.72, 95% CI=0.40-1.29; P=0.27).

CONCLUSION

The incidence of TE was low in our Chinese cohort. Stage IV disease increased the risk of TE. Overall survival was not affected by TE or its treatment.

Recommendations for the use of next-generation sequencing in patients with metastatic cancer in the Asia-Pacific region: a report from the APODDC working group

INTRODUCTION

Next-generation sequencing (NGS) diagnostics have shown clinical utility in predicting survival benefits in patients with certain cancer types who are undergoing targeted drug therapies. Currently, there are no guidelines or recommendations for the use of NGS in patients with metastatic cancer from an Asian perspective. In this article, we present the Asia-Pacific Oncology Drug Development Consortium (APODDC) recommendations for the clinical use of NGS in metastatic cancers.

METHODS

The APODDC set up a group of experts in the field of clinical cancer genomics to (i) understand the current NGS landscape for metastatic cancers in the Asia-Pacific (APAC) region; (ii) discuss key challenges in the adoption of NGS testing in clinical practice; and (iii) adapt/modify the European Society for Medical Oncology guidelines for local use. Nine cancer types [breast cancer (BC), gastric cancer (GC), nasopharyngeal cancer (NPC), ovarian cancer (OC), prostate cancer, lung cancer, and colorectal cancer (CRC) as well as cholangiocarcinoma and hepatocellular carcinoma (HCC)] were identified, and the applicability of NGS was evaluated in daily practice and/or clinical research. Asian ethnicity, accessibility of NGS testing, reimbursement, and socioeconomic and local practice characteristics were taken into consideration.

RESULTS

The APODDC recommends NGS testing in metastatic non-small-cell lung cancer (NSCLC). Routine NGS testing is not recommended in metastatic BC, GC, and NPC as well as cholangiocarcinoma and HCC. The group suggested that patients with epithelial OC may be offered germline and/or somatic genetic testing for BReast CAncer gene 1 (BRCA1), BRCA2, and other OC susceptibility genes. Access to poly (ADP-ribose) polymerase inhibitors is required for NGS to be of clinical utility in prostate cancer. Allele-specific PCR or a small-panel multiplex-gene NGS was suggested to identify key alterations in CRC.

CONCLUSION

This document offers practical guidance on the clinical utility of NGS in specific cancer indications from an Asian perspective.

Vascular smooth muscle cell c-Fos is critical for foam cell formation and atherosclerosis

BACKGROUND

Hyperlipidemia-induced vascular smooth muscle cell (VSMC)-derived foam cell formation is considered a crucial event in the development of atherosclerosis. Since c-Fos emerges as a key modulator of lipid metabolism, we investigated whether c-Fos plays a role in hyperlipidemia-induced VSMC-derived foam cell formation and atherosclerosis.

APPROACH AND RESULTS

c-Fos expression was observed in VSMCs in atherosclerotic plaques from patients and western diet-fed atherosclerosis-prone LDLR^-/- and ApoE^-/- mice by immunofluorescence staining. To ascertain c-Fos's function in atherosclerosis development, VSMC-specific c-Fos deficient mice in ApoE^-/- background were established. Western diet-fed c-Fos^VSMCKOApoE^-/- mice exhibited a significant reduction of atherosclerotic lesion formation as measured by hematoxylin and eosin staining, accompanied by decreased lipid deposition within aortic roots as determined by Oil red O staining. Primary rat VSMCs were isolated to examine the role of c-Fos in lipid uptake and foam cell formation. oxLDL stimulation resulted in VSMC-derived foam cell formation and elevated intracellular mitochondrial reactive oxygen species (mtROS), c-Fos and LOX-1 levels, whereas specific inhibition of mtROS, c-Fos or LOX-1 lessened lipid accumulation in oxLDL-stimulated VSMCs. Mechanistically, oxLDL acts through mtROS to enhance transcription activity of c-Fos to facilitate the expression of LOX-1, exerting a feedforward mechanism with oxLDL to increase lipid uptake and propel VSMC-derived foam cell formation and atherogenesis.

CONCLUSION

Our study demonstrates a fundamental role of mtROS/c-Fos/LOX-1 signaling pathway in promoting oxLDL uptake and VSMC-derived foam cell formation during atherosclerosis. c-Fos may represent a promising therapeutic target amenable to clinical translation in the future.

Abstract 512: Mechanisms And Therapeutic Targeting Of Epsins In Regulating Liver Steatosis

Background: Chronic liver disease, such as non-alcoholic fatty liver disease (NAFLD), is one of the most prevalent diseases, with 4.5 million people diagnosed in the U.S. in 2018. If untreated, fibrosis-induced cirrhosis will eventually develop into hepatocellular carcinoma. Epsins are highly conserved endocytic adaptor proteins, participating in selected membrane receptor endocytosis. Globally disruption of both epsin 1 and 2 induced embryonic lethality by disruption of Notch signaling pathway, which has recently been recognized as a key player in metabolism. Thus, we aimed to study the role of epsins in controlling lipid metabolism and genes involved in live immunity.

Hypothesis: We hypothesize that epsins promote the development of liver diseases, including NAFLD, particularly non-alcoholic steatohepatitis (NASH).

Methodology and Results: Bulk RNA-seq analysis indicated that most differentially expressed genes (DEGs) enriched in lipid metabolism were down-regulated and immune function up-regulated in epsins liver DKO. RT-PCR confirmed other DEGs such as Il1b and Ccr5 expression. Compared to WT mice, epsins liver DKO mice harbor more Kupffer cells, residential macrophages in the liver that are thought to play a role in fighting infection and harmful insults. Consistent with this, further mining bulk RNA-seq data revealed that Kupffer cells/macrophages markers, including F4/80 and Cd11b, were increased in liver DKO. Moreover, the master transcription factor, Spi1 (PU.1), increased in liver DKO. Furthermore, RT-qPCR showed the upregulation of F4/80, Cd11b, and Spi1 in liver from WT and epsins DKO mice. Importantly, liver samples from epsin liver DKO mice contain more F4/80-positive cells. Single-cell RNA sequencing data suggested elevated Kupffer cells in Liver DKO mice. As Kupffer cells play a significant anti-inflammatory role and epsins depletion reduces lipid synthesis, we anticipate that epsins deficiency in liver will combat liver inflammation and damage caused by a build-up of fat in the liver leading to NASH.

Conclusion: Epsins in liver promote lipid synthesis and suppress immune function by reducing Kupffer cell development. Targeting epsins may provide a new strategy to treat chronic liver diseases, such as cirrhosis and NASH.

Abstract 506: Targeting Macrophage Epsins Inhibits Lipid Uptake And Facilitates Cholesterol Efflux In Atherosclerosis

Resolving atheroma and hindering their transition to vulnerable atherosclerotic plaque is pivotal in preventing deadly episodes such as heart attacks and strokes. Despite recent advances in the treatment, atherosclerosis remains the root cause of death worldwide. Excess cholesterol accumulation and deposition trigger a complex inflammatory response in atherosclerosis. Our recent studies demonstrate that epsins, a family of endocytic adaptors, are critically responsible for the aforesaid events in atherosclerosis; however, the underlying mechanisms and whether targeting epsins hinders cholesterol uptake, promote cholesterol efflux and reverse transport in macrophages to reduce inflammation and accelerate atheroma resolution remains an open question. To explore the therapeutic intervention by harnessing recent development in nanomedicine, we silenced epsins in lesional macrophages by specific delivery of nanoparticles (NPs) carrying epsin siRNAs. We showed that inhibit epsins significantly diminished atherosclerotic plaque size and promoted plaque regression. Mechanistically, epsins bind to CD36 to facilitate CD36-mediated lipid uptake by enhancing its endocytosis and recycling. Conversely, epsins promote ABCG1 degradation via lysosomes and hamper ABCG1-mediated cholesterol efflux and reverse cholesterol transport. Furthermore, myeloid-specific epsins double knockout mice (LysM-DKO) harboring a genetically reduced ABCG1 level (LysM-DKO-ABCG1 fl/+ ) were generated. In LysM-DKO-ABCG1 fl/+ macrophages, enhanced cholesterol efflux and reverse transport due to epsins deficiency was suppressed. Our findings suggest that targeting epsins in lesional macrophages may offer therapeutic benefits in preventing or treating advanced atherosclerosis.

Diabetes and Its Cardiovascular Complications: Comprehensive Network and Systematic Analyses

Diabetes mellitus is a worldwide health problem that usually comes with severe complications. There is no cure for diabetes yet and the threat of these complications is what keeps researchers investigating mechanisms and treatments for diabetes mellitus. Due to advancements in genomics, epigenomics, proteomics, and single-cell multiomics research, considerable progress has been made toward understanding the mechanisms of diabetes mellitus. In addition, investigation of the association between diabetes and other physiological systems revealed potentially novel pathways and targets involved in the initiation and progress of diabetes. This review focuses on current advancements in studying the mechanisms of diabetes by using genomic, epigenomic, proteomic, and single-cell multiomic analysis methods. It will also focus on recent findings pertaining to the relationship between diabetes and other biological processes, and new findings on the contribution of diabetes to several pathological conditions.

Non-alcoholic Steatohepatitis Pathogenesis, Diagnosis, and Treatment

There has been a rise in the prevalence of non-alcohol fatty liver disease (NAFLD) due to the popularity of western diets and sedentary lifestyles. One quarter of NAFLD patients is diagnosed with non-alcoholic steatohepatitis (NASH), with histological evidence not only of fat accumulation in hepatocytes but also of liver cell injury and death due to long-term inflammation. Severe NASH patients have increased risks of cirrhosis and liver cancer. In this review, we discuss the pathogenesis and current methods of diagnosis for NASH, and current status of drug development for this life-threatening liver disease.

Evaluating online learning engagement of nursing students

BACKGROUND

Previous studies suggest that increased learning satisfaction may encourage learning engagement in an online learning environment.

OBJECTIVES

To evaluate the level of learning engagement and its relationship with students' perceived learning satisfaction in an online clinical nursing elective course.

DESIGN

A prospective interventional study.

SETTINGS

A nursing course was converted to an online format because of the coronavirus disease COVID pandemic.

PARTICIPANTS

Part-time post-registration nursing undergraduates enrolled in an elective online clinical course.

METHODS

Related teaching and learning strategies were deployed in the course using the Community of Inquiry framework. All students who completed the course were invited to complete an online survey that included a validated Online Student Engagement questionnaire (OSE). Pearson's correlations were used to determine the association between perceived learning satisfaction and learning engagement. A logistic regression model was used to explore the associations of gender, age, working experience and perceived learning satisfaction with higher learning engagement.

RESULTS

The questionnaires were completed by 56 of 68 students (82%). The Pearson's correlation coefficient between the mean perceived learning satisfaction and OSE scores was 0.75 (p < .001). Twenty-five students (45%) were identified as highly engaged, using a cut-off of ≥3.5 for the mean OSE score. The mean perceived learning satisfaction (SD) score differed significantly between highly engaged and not highly engaged students [4.02 (0.49) vs. 3.27 (0.62), p < .001]. The logistic regression model showed that a greater perceived learning satisfaction [adjusted odds ratio (OR): 17.2, 95% C.I.: 3.46-86.0, p = .001] was associated with an increased likelihood of higher learning engagement, and >1 year of working experience (adjusted OR: 0.11, 95% C.I.: 0.01-0.89, p = .0039) was associated with a decreased likelihood of higher learning engagement.

CONCLUSIONS

The study findings suggest that perceived learning satisfaction predicts learning engagement among nursing students in this online learning course.

Registry to investigate the efficacy and safety of the VenaBlock© VeIn SEaling system for VaRicose veins in SingApore - Six months results of the RIVIERA trial

BACKGROUND

The Venablock^© Venous Closure System (Invamed, Ankara, Turkey) is a novel cyanoacrylate-based non-thermal non-tumescent embolization device to block refluxing truncal veins for chronic venous insufficiency and varicose veins. The aim was to prospectively evaluate the safety and 6 months efficacy of Venablock^© for the treatment of primary great saphenous vein (GSV) and small saphenous vein (SSV) incompetency in a multi-ethnic cohort from Singapore.

METHODS

This was a single arm, single investigator prospective study of 29 patients (39 limbs, 39 truncal veins) recruited over a 5-month period (August 2019 to February 2020), who were treated with the Venablock^© device at a tertiary vascular unit in Singapore. Patients with symptomatic varicose veins (C2-6) and had truncal reflux > 0.5 second on venous Duplex ultrasound were included. Follow-up occurred at 2 weeks, 3 and 6 months with dedicated quality of life questionnaires and a targeted Duplex ultrasound performed to check for continued venous occlusion.

RESULT

Mean age was 61.4 (±11.0) years and mean BMI was 26.2 (±5.7) kg/m². 11/29 (37.9%) were males. Most common CEAP class treated was 2 (12/29, 41.3%). Mean diameter of treated GSV was 5.7 (±2.0) mm, 4.8 (±1.7) mm and 4.2 (±1.3) mm for the proximal, mid and distal above knee segments respectively. Mean time from access puncture to sheath removal was 23.4 (±10.0) mins. Vein occlusion at 2 weeks, 3 and 6 months was 39/39 (100%), 39/39 (100%) and 36/37 (97.2%) respectively. 5/29 (17.2%) developed puncture site infections, of which 3/29 (7.7%) required formal surgical drainage. 3/29 (7.7%) developed phlebitis. At 6 months, revised Venous Clinical Severity Score improved from 5.2 (±3.5) to 2.1 (±2.9; p < .001); EuroQol-5 Dimension score, from 7.4 (±2.1) to 5.7 (±1.4; p < .001); Aberdeen Varicose Vein Questionnaire score, from 18.1 (±15.5) to 7.9 (±8.9; p = .007); and Chronic Venous Insufficiency Questionnaire, from 18.6 (±16.2) to 4.5 (±6.3; p < .001).

CONCLUSION

Venablock^© is a safe and efficacious option of treating truncal venous insufficiency in a multi-ethnic Asian cohort from Singapore in the short term. There is a significant improvement in QoL. Longer follow-up is required to assess the durability of this technique, in particular the higher puncture site infection rates observed compared to other glue-based therapies.

Endocytic Adaptors in Cardiovascular Disease

Endocytosis is the process of actively transporting materials into a cell by membrane engulfment. Traditionally, endocytosis was divided into three forms: phagocytosis (cell eating), pinocytosis (cell drinking), and the more selective receptor-mediated endocytosis (clathrin-mediated endocytosis); however, other important endocytic pathways (e.g., caveolin-dependent endocytosis) contribute to the uptake of extracellular substances. In each, the plasma membrane changes shape to allow the ingestion and internalization of materials, resulting in the formation of an intracellular vesicle. While receptor-mediated endocytosis remains the best understood pathway, mammalian cells utilize each form of endocytosis to respond to their environment. Receptor-mediated endocytosis permits the internalization of cell surface receptors and their ligands through a complex membrane invagination process that is facilitated by clathrin and adaptor proteins. Internalized vesicles containing these receptor-ligand cargoes fuse with early endosomes, which can then be recycled back to the plasma membrane, delivered to other cellular compartments, or destined for degradation by fusing with lysosomes. These intracellular fates are largely determined by the interaction of specific cargoes with adaptor proteins, such as the epsins, disabled-homolog 2 (Dab2), the stonin proteins, epidermal growth factor receptor substrate 15, and adaptor protein 2 (AP-2). In this review, we focus on the role of epsins and Dab2 in controlling these sorting processes in the context of cardiovascular disease. In particular, we will focus on the function of epsins and Dab2 in inflammation, cholesterol metabolism, and their fundamental contribution to atherogenicity.

Impact of Acute and Chronic Hypertension on Changes in Pial Collateral Tone In Vivo During Transient Ischemia

We investigated vasoconstrictive responses of pial collaterals in vivo at baseline and during transient middle cerebral artery occlusion during chronic hypertension. A cranial window was used to measure diameter of leptomeningeal anastomoses (pial collaterals) in male Wistar (n=8) and spontaneously hypertensive rats (SHRs; n=8) using video dimensional analysis. Middle cerebral artery occlusion was induced by remote filament for 2 hours with 2 hours reperfusion. Phenylephrine was infused during ischemia as a pressor therapy. Active diameters of pial collaterals were significantly smaller in SHRs versus Wistar (14.1±1.5 versus 21.6±2.8 µm; P<0.01); however, passive diameters were similar (25.0±2.9 versus 25.0±2.6 µm; P>0.05). Basal tone of pial collaterals before occlusion was 42±5% in SHRs versus 15±4% in Wistar (P<0.01). Tone decreased in both Wistar and SHRs during occlusion but remained higher in SHRs (9±2% versus 29±4%; P<0.05). Phenylephrine increased blood pressure in both groups but had little effect on leptomeningeal anastomoses diameters. Reperfusion caused vasoconstriction of pial collaterals, increasing tone from 8±1% to 20±5% in Wistar and 29±5% to 44±5% in SHRs (P<0.01). Higher tone in pial collaterals from SHRs basally and during occlusion/reperfusion could limit flow to the penumbra and promote evolution of infarction. Sustained elevated tone of pial collaterals from SHRs with phenylephrine suggests pressor therapy may not be appropriate during chronic hypertension.

Inhibition of PAI (Plasminogen Activator Inhibitor)-1 Improves Brain Collateral Perfusion and Injury After Acute Ischemic Stroke in Aged Hypertensive Rats

Background and Purpose- Aging and hypertension, comorbidities prevalent in the stroke population, are associated with poor collateral status and worsened stroke outcome. However, underlying mechanisms by which these conditions affect stroke outcome are not clear. We studied the role of PAI (plasminogen activator inhibitor)-1 that is increased in aging and hypertension on brain and vascular expression of inflammatory factors and perfusion that may contribute to worse stroke outcomes. Methods- Aged (≈50 weeks) and young (≈18 weeks) spontaneously hypertensive rats (SHR) were subjected to ischemia by middle cerebral artery occlusion (2 hours) and reperfusion (2 hours) with or without treatment with the PAI-1 inhibitor TM5441. Changes in middle cerebral artery and collateral perfusion territories were measured by multisite laser Doppler. Reactivity to TM5441 was studied using isolated and pressurized leptomeningeal anastomotic arterioles. Brain injury was determined by 2,3,5-triphenyltetrazolium staining and quantitative immunohistochemistry of amyloid-β-42, PAI-1, and hemoglobin. Circulating inflammatory factors were measured by ELISA. Results- Changes in cerebral blood flow during middle cerebral artery occlusion were similar between groups, with both having poor collateral perfusion and incomplete reperfusion. However, aged SHR had greater brain injury versus young (41±2 versus 23±2%, P<0.05) as well as increased brain deposition of amyloid-β-42 and circulating oxLDL (oxidized low-density lipoprotein). Erythrocyte aggregation and hemorrhage within the injured brain was observed in 50% of aged but no young SHR, with increased circulating PAI-1 in this subgroup of aged SHR (16±3 versus 6±2 ng/mL, P<0.05). PAI-1 inhibition with TM5441 improved brain injury but did not affect hemorrhage. TM5441 increased collateral perfusion by 38±7% and dilated leptomeningeal anastomotic arterioles by 44±10%, which was abolished by nitric oxide synthase inhibition. Conclusions- Increased injury in aged SHR seemed to be related to poor collateral perfusion, hemorrhagic transformation, increased amyloid-β-42, and oxidative stress. PAI-1 inhibition reduced infarction in both groups of SHR that possibly due, in part, to increased collateral perfusion.

A comparison between Caucasian and Asian superficial venous anatomy and reflux patterns – Implications for potential precision endovenous ablation therapy

Objectives

The aim of this study is to investigate whether there are differences between predominantly Caucasians and Asians from two disparate cohorts around the globe, with regard to their pre-operative venous reflux patterns and truncal vein characteristics, which could potentially help clinicians tailor venous treatment for chronic venous insufficiency on a more individualised basis in different parts of the world.

Methods

A total of 200 lower limb chronic venous insufficiency duplex studies (127 Singaporean (predominantly Asian) patients) and 200 lower limb chronic venous insufficiency duplex scans (137 Americans predominantly Caucasians) were analysed and compared for differences in venous anatomy and reflux characteristics.

Results

Asian patients from Singapore presented with higher CEAP scores compared to the predominantly Caucasian cohort from the US (30% CEAP 4a or greater vs. 17.5%; p < 0.01). Singaporeans had more great saphenous vein reflux starting at the sapheno-femoral junction (86% vs. 73%; p < 0.01) and ending at the ankle (93% vs. 46%; p < 0.01). Vein diameters were generally larger in the US cohort of patients (median 5.7 mm vs. 2.9 mm; p < 0.01).

Conclusions

The predominantly Asian cohort from Singapore had smaller diameter truncal veins, longer segments of truncal vein reflux and present later with more advanced chronic venous insufficiency compared to their American counterparts. This information could help tailor endovenous ablation on a more individualised basis in the future.

Transient receptor potential vanilloid-4 channels are involved in diminished myogenic tone in brain parenchymal arterioles in response to chronic hypoperfusion in mice

AIM

Adaptive responses of brain parenchymal arterioles (PAs), a target for cerebral small vessel disease, to chronic cerebral hypoperfusion are largely unknown. Previous evidence suggested that transient receptor potential vanilloid 4 channels may be involved in the regulation of cerebrovascular tone. Therefore, we investigated the role of TRPV4 in adaptations of PAs in a mouse model of chronic hypoperfusion.

METHODS

TRPV4 knockout (^-/- ) and wild-type (WT) mice were subjected to unilateral common carotid artery occlusion (UCCAo) for 28 days. Function and structure of PAs ipsilateral to UCCAo were studied isolated and pressurized in an arteriograph.

RESULTS

Basal tone of PAs was similar between WT and TRPV4^-/- mice (22 ± 3 vs 23 ± 5%). After UCCAo, active inner diameters of PAs from WT mice were larger than control (41 ± 2 vs 26 ± 5 μm, P < 0.05) that was due to decreased tone (8 ± 2 vs 23 ± 5%, P < 0.05), increased passive inner diameters (46 ± 3 vs 34 ± 2 μm, P < 0.05), and decreased wall-to-lumen ratio (0.104 ± 0.01 vs 0.137 ± 0.01, P < 0.05). However, UCCAo did not affect vasodilation to a small- and intermediate-conductance calcium-activated potassium channel agonist NS309, the nitric oxide (NO) donor sodium nitroprusside, or constriction to a NO synthase inhibitor L-NNA. Wall thickness and distensibility in PAs from WT mice were unaffected. In TRPV4^-/- mice, UCCAo had no effect on active inner diameters or tone and only increased passive inner diameters (53 ± 2 vs 43 ± 3 μm, P < 0.05).

CONCLUSION

Adaptive response of PAs to chronic cerebral hypoperfusion includes myogenic tone reduction and outward remodelling. TRPV4 channels were involved in tone reduction but not outward remodelling in response to UCCAo.

The importance of comorbidities in ischemic stroke: Impact of hypertension on the cerebral circulation

Comorbidities are a hallmark of stroke that both increase the incidence of stroke and worsen outcome. Hypertension is prevalent in the stroke population and the most important modifiable risk factor for stroke. Hypertensive disorders promote stroke through increased shear stress, endothelial dysfunction, and large artery stiffness that transmits pulsatile flow to the cerebral microcirculation. Hypertension also promotes cerebral small vessel disease through several mechanisms, including hypoperfusion, diminished autoregulatory capacity and localized increase in blood-brain barrier permeability. Preeclampsia, a hypertensive disorder of pregnancy, also increases the risk of stroke 4-5-fold compared to normal pregnancy that predisposes women to early-onset cognitive impairment. In this review, we highlight how comorbidities and concomitant disorders are not only risk factors for ischemic stroke, but alter the response to acute ischemia. We focus on hypertension as a comorbidity and its effects on the cerebral circulation that alters the pathophysiology of ischemic stroke and should be considered in guiding future therapeutic strategies.

Pharmacologically increasing collateral perfusion during acute stroke using a carboxyhemoglobin gas transfer agent (Sanguinate™) in spontaneously hypertensive rats

Similar to patients with chronic hypertension, spontaneously hypertensive rats (SHR) develop fast core progression during middle cerebral artery occlusion (MCAO) resulting in large final infarct volumes. We investigated the effect of Sanguinate™ (SG), a PEGylated carboxyhemoglobin (COHb) gas transfer agent, on changes in collateral and reperfusion cerebral blood flow and brain injury in SHR during 2 h of MCAO. SG (8 mL/kg) or vehicle ( n = 6-8/group) was infused i.v. after 30 or 90 min of ischemia with 2 h reperfusion. Multi-site laser Doppler probes simultaneously measured changes in core MCA and collateral flow during ischemia and reperfusion using a validated method. Brain injury was measured using TTC. Animals were anesthetized with choral hydrate. Collateral flow changed little in vehicle-treated SHR during ischemia (-8 ± 9% vs. prior to infusion) whereas flow increased in SG-treated animals (29 ± 10%; p < 0.05). In addition, SG improved reperfusion regardless of time of treatment; however, brain injury was smaller only with early treatment in SHR vs. vehicle (28.8 ± 3.2% vs. 18.8 ± 2.3%; p < 0.05). Limited collateral flow in SHR during MCAO is consistent with small penumbra and large infarction. The ability to increase collateral flow in SHR with SG suggests that this compound may be useful as an adjunct to endovascular therapy and extend the time window for treatment.

Abstract WP407: Function and Reactivity of Pial Collaterals In Vivo in Normotensive and Hypertensive Rats: Response to Ischemia and Reperfusion

Background: Collateral therapeutics is an emerging treatment for acute ischemic stroke. However, whether pial collaterals have tone in vivo and thus the ability to vasodilate is not clear. We investigated the function of pial collaterals in vivo during ischemia and reperfusion in normotensive and hypertensive rats that are known to have poor collaterals. We hypothesized that pial collaterals from spontaneously hypertensive rats (SHR) would have greater basal tone during ischemia and reperfusion than normotensive Wistar rats that could contribute to decreased collateral perfusion.

Methods: A cranial window was performed in SHR (n=4) and Wistar (n=4) rats prior to remote middle cerebral artery occlusion (MCAo) under pentobarbital anesthesia. Video microscopy was used to measure changes in diameter of leptomeningeal anastomoses (LMAs) during MCAo for 2 hrs and 2 hrs reperfusion (Figure, top). After reperfusion, the brain surface was exposed to physiological saline solution with EDTA (67 mmol/L) to measure fully relaxed diameters and calculate basal tone. Blood pressure was measured via arterial catheter and animals were mechanically ventilated to control blood gases.

Results: Blood pressure was significantly elevated in SHR vs. Wistar rats (157±9 vs. 107±7; p<0.01). LMAs (~15-20 μm diameters) had basal tone that was higher in SHR vs. Wistar (15.4±9% vs. 8.4±4.9%; n.s.). After 5 min MCAo, tone in LMAs from Wistar rats decreased to 2.7±1.5% but increased to 17.2±9.7% in SHR. Reperfusion caused vasoconstriction of LMAs from both groups and increased tone to 18.7±5.3% in Wistar and to 29.5±9.7% in SHR (p<0.01 vs. basal for both; Figure, bottom).

Conclusions: These data demonstrate functional pial collaterals in normotensive and hypertensive rats. While increased tone of LMAs during MCAo in SHR could limit perfusion to the penumbra, vasoconstriction of LMAs from both groups suggests therapeutic intervention to increase diameter and salvage at risk tissue is possible.

The Efficacy of Emergency Medicine Ward for the Management of Patients with Mental Disorders

Objective

Patients with mental disorders are one of the target groups selected for management in the Emergency Medicine Ward (EMW) with the enrolment of psychiatric advanced practice nurses. This study aimed to determine whether the EMW can be efficiently used for the management of patients with mental disorders in terms of length of stay (LOS), admission rate, and re-attendance rate when compared with the medical ward.

Methods

This was a retrospective descriptive study. Patients with mental disorders were defined and recruited from the Princess Margaret Hospital during two selected study periods: pre-opening (pre-EMW) and post-opening (post-EMW) of the EMW. All emergency department records of patients with mental disorders within these two periods were reviewed and data of the selected samples were retrieved from different computer databases.

Results

The total number of patients with mental disorders was 565 in the pre-EMW period and 404 in the post-EMW period; 214 (37.9%) cases were admitted into the medical ward in the pre-EMW period while only 62 (15.3%) were admitted into the medical ward in the post-EMW period. The mean LOS in the pre-EMW period was 67.7 hours. For the post-EMW period, the mean LOS was 32.3 hours. The reduction in mean LOS was 35.4 hours, and 82% of the study patients treated in the EMW were discharged within 48 hours. Notably, 23.3% of the cases re-attended the emergency department after discharge from the medical ward, whereas only 8.8% of cases re-attended after discharge from the EMW.

Conclusion

Patients with mental disorders or related problems can be efficaciously managed in the EMW, as evidenced by a decrease in the length of stay, admission rate, and re-attendance rate.

Treatment with low dose fasudil for acute ischemic stroke in chronic hypertension

We investigated the effect of Rho kinase inhibition on changes in cerebral blood flow (CBF), brain injury and vascular function after ischemic stroke in spontaneously hypertensive rats (SHR). Changes in core MCA and collateral perfusion were measured by a validated laser Doppler method. Animals underwent 2 h tMCAO and 2 h reperfusion. Fasudil (0.1 mg/kg, i.v.) or vehicle was given at 30 min ischemia (n = 9/group; mean (SD)). Brain injury was determined by 2,3,5-triphenyltetrazolium chloride staining. To determine the effect of fasudil on vascular function, fasudil was given 10 min before reperfusion and parenchymal arterioles studied isolated (n = 6/group; mean(SD)). Collateral perfusion was low in vehicle-treated SHR (-8(32)%) that changed minimally with fasudil (6(24)%, p > 0.05, effect size: 0.47;95% CI-0.49-1.39). Reperfusion CBF was below baseline in vehicle (-27(26)%) and fasudil (-32(25)%, p > 0.05, effect size: 0.19; 95% CI-0.74-1.11) groups, suggesting incomplete reperfusion in both groups. Fasudil had little effect on brain injury volume (28(13)% vs. 36(7)% in vehicle, p > 0.05, effect size: 0.75; 95% CI-0.24-1.66). In isolated parenchymal arterioles, myogenic tone was similar between groups (37(6)% vs. 38(10)% in vehicle, p > 0.05, effect size: 0.09; 95% CI-1.05-1.21). There were no differences with fasudil treatment vs. vehicle in perfusion, brain injury and vascular function that may be related to the low dose that had minimal blood pressure lowering effect.

Effect of hypertension and peroxynitrite decomposition with FeTMPyP on CBF and stroke outcome

We investigated the effect of peroxynitrite decomposition catalyst FeTMPyP treatment on perfusion deficit, vascular function and stroke outcome in Wistar ( n = 26) and spontaneously hypertensive rats stroke-prone (SHRSP; n = 26) that underwent tMCAO for 2 h or Sham operation. Peri-infarct CBF was measured by hydrogen clearance in the absence or presence of FeTMPyP (10 mg/kg, i.v.) or vehicle 10 min before reperfusion. Myogenic tone of parenchymal arterioles (PAs) was measured as an indication of small vessel resistance (SVR). Baseline CBF was similar between Wistar and SHRSP (114 ± 12 vs. 132 ± 9 mL/100 g/min); however, MCAO caused greater perfusion deficit in SHRSP (24 ± 6 vs. 7 ± 1 mL/100 g/min; p < 0.05) and increased infarct volume by TTC (12 ± 6 vs. 32 ± 2%; p < 0.05). Reperfusion CBF was decreased from baseline in both SHRSP and Wistar (54 ± 16 and 46 ± 19 mL/100 g/min; p < 0.05), suggesting increased infarction in SHRSP was related to greater perfusion deficit. PAs from SHRSP had increased tone vs. Wistar that was enhanced after tMCAO. FeTMPyP treatment did not affect CBF during ischemia or reperfusion, or tone of PAs, but decreased the incidence of hemorrhage in SHRSP by 50%. Thus, increased tone in PAs from SHRSP could increase perfusion deficit during MCAO that was not alleviated by FeTMPyP.

Abstract 62: Sanguinate TM Opens Collaterals, Improves Reperfusion and Decreases Infarct in Hypertensive Rats

Background: The PEGylated cell-free carboxyhemoglobin gas exchanger Sanguinate TM (SG) has multiple beneficial actions that may improve stroke outcome including anti-inflammatory, vasodilatory and oxygen delivery capacity. We investigated the ability of SG to improve infarction in spontaneously hypertensive rats (SHR) that are known to have vasoconstricted pial collaterals and poor stroke outcome.

Methods: SHR were treated IV with SG (8 ml/kg; n=8) or vehicle (Lactated Ringer’s; n=6) plus tPA (0.9 mg/ml) after 30 min of proximal middle cerebral artery occlusion (MCAO) by filament occlusion. Pial collateral and reperfusion flow were measured for 2 hrs of occlusion and 2 hrs reperfusion using dual laser Doppler probes in the core (Bregma -2mm, lateral +4mm) and collateral (Bregma +2mm, lateral +3mm) territories. Collateral openings (number and duration (min)) were assessed off cerebral blood flow (CBF) tracings, defined as independent of changes in blood pressure (Fig. 1; arrows show openings). Infarction was measured using triphenyltetrazolium chloride (TTC). Animals were anesthetized with chloral hydrate and ventilated to maintain blood gases within normal ranges.

Results: Vehicle-treated SHR had incomplete reperfusion and poor collaterals that was improved by SG. During MCAO, SG increased the number of collateral openings from 1.0±0.8 to 3.1±0.8 (p=0.03) and duration of openings from 6.0±5.8 to 35.4±9.8 min (p=0.04; Fig. 2). Reperfusion CBF was -43±6% of baseline in vehicle-treated, but only -7±19% of baseline in SG-treated animals. Improved collateral and reperfusion flow with SG was associated with decreased infarct volume vs. vehicle (28.8±3.2% vs. 18.8±2.3%; p<0.05). The presence of tPA had no effect in either group.

Conclusions: Smaller infarction with early SG treatment may be related to its ability to open constricted collaterals in SHR and improve reperfusion. Thus, SG may be able to extend the time window for endovascular or tPA treatment.

Development and validation of algorithms for the detection of statin myopathy signals from electronic medical records

The purpose of this study was to develop and validate sensitive algorithms to detect hospitalized statin-induced myopathy (SIM) cases from electronic medical records (EMRs). We developed four algorithms on a training set of 31,211 patient records from a large tertiary hospital. We determined the performance of these algorithms against manually curated records. The best algorithm used a combination of elevated creatine kinase (>4× the upper limit of normal (ULN)), discharge summary, diagnosis, and absence of statin in discharge medications. This algorithm achieved a positive predictive value of 52-71% and a sensitivity of 72-78% on two validation sets of >30,000 records each. Using this algorithm, the incidence of SIM was estimated at 0.18%. This algorithm captured three times more rhabdomyolysis cases than spontaneous reports (95% vs. 30% of manually curated gold standard cases). Our results show the potential power of utilizing data and text mining of EMRs to enhance pharmacovigilance activities.

Pial Collateral Reactivity During Hypertension and Aging: Understanding the Function of Collaterals for Stroke Therapy

Supplemental Digital Content is available in the text.

Background and Purpose—

We investigated vasoactive properties of leptomeningeal arterioles (LMAs) under normotensive conditions and during hypertension and aging that are known to have poor collateral flow and little salvageable tissue.

Methods—

LMAs, identified as distal anastomotic arterioles connecting middle and anterior cerebral arteries, were studied isolated and pressurized from young (18 weeks) or aged (48 weeks) normotensive Wistar Kyoto (WKY18, n=14; WKY48, n=6) rats and spontaneously hypertensive rats (SHR18, n=16; SHR48, n=6). Myogenic tone and vasoactive responses to pressure as well as endothelial function and ion channel activity were measured.

Results—

LMAs from WKY18 had little myogenic tone at 40 mm Hg (8±3%) that increased in aged WKY48 (30±6%). However, LMAs from both WKY groups dilated to increased pressure and demonstrated little myogenic reactivity, a response that would be conducive to collateral flow. In contrast, LMAs from both SHR18 and SHR48 displayed considerable myogenic tone (56±8% and 43±7%; P<0.01 versus WKY) and constricted to increased pressure. LMAs from both WKY and SHR groups had similar basal endothelial nitric oxide and IK channel activity that opposed tone. However, dilation to sodium nitroprusside, diltiazem and 15 mmol/L KCl was impaired in LMAs from SHR18.

Conclusions—

This study shows for the first time that LMAs from young and aged SHR are vasoconstricted and have impaired vasodilatory responses that may contribute to greater perfusion deficit and little penumbral tissue. These results also suggest that therapeutic opening of pial collaterals is possible during middle cerebral artery occlusion to create penumbral tissue and prevent infarct expansion.

Roles of Caveolin-1 in Angiotensin II-Induced Hypertrophy and Inward Remodeling of Cerebral Pial Arterioles

Angiotensin II (Ang II) is a major determinant of inward remodeling and hypertrophy in pial arterioles that may have an important role in stroke during chronic hypertension. Previously, we found that epidermal growth factor receptor is critical in Ang II-mediated hypertrophy that may involve caveolin-1 (Cav-1). In this study, we examined the effects of Cav-1 and matrix metalloproteinase-9 (MMP9) on Ang II-mediated structural changes in pial arterioles. Cav-1-deficient (Cav-1(-/-)), MMP9-deficient (MMP9(-/-)), and wild-type mice were infused with either Ang II (1000 ng/kg per minute) or saline via osmotic minipumps for 28 days (n=6-8 per group). Systolic arterial pressure was measured by a tail-cuff method. Pressure and diameter of pial arterioles were measured through an open cranial window in anesthetized mice. Cross-sectional area of the wall was determined histologically in pressurized fixed pial arterioles. Expression of Cav-1, MMP9, phosphorylated epidermal growth factor receptor, and Akt was determined by Western blotting and immunohistochemistry. Deficiency of Cav-1 or MMP9 did not affect Ang II-induced hypertension. Ang II increased the expression of Cav-1, phosphorylated epidermal growth factor receptor, and Akt in wild-type mice, which was attenuated in Cav-1(-/-) mice. Ang II-induced hypertrophy, inward remodeling, and increased MMP9 expression in pial arterioles were prevented in Cav-1(-/-) mice. Ang II-mediated increases in MMP9 expression and inward remodeling, but not hypertrophy, were prevented in MMP9(-/-) mice. In conclusion, Cav-1 is essential in Ang II-mediated inward remodeling and hypertrophy in pial arterioles. Cav-1-induced MMP9 is exclusively involved in inward remodeling, not hypertrophy. Further studies are needed to determine the role of Akt in Ang II-mediated hypertrophy.

Abstract 223: Leptomeningeal Arteriole Vasoconstriction during Hypertension: Targeting Pial Collaterals in Stroke Treatment

Introduction: Collateral perfusion via leptomeningeal arterioles (LMAs) between middle and anterior cerebral artery (MCA/ACA) territories sustains the penumbra during MCA occlusion (MCAO) and is a key variable in stroke outcome. Hypertension is associated with poor stroke outcome, little penumbral tissue and larger infarctions. Here, we investigated the vasoactive properties of isolated and pressurized LMAs from normotensive and hypertensive animals as a contributor to poor collateral flow.

Hypothesis: Compared to normotensive animals, LMAs from hypertensive animals are vasoconstricted that limits collateral perfusion and penumbral tissue.

Methods: LMAs between MCA and ACA distal branches were dissected from 18 wk old male normotensive Wistar Kyoto (WKY, n=14) and spontaneously hypertensive rats (SHR; n=16), mounted on glass cannulas and studied pressurized.

Results: LMAs from WKY had little basal tone and responded passively to increased pressure from 5 to 80 mmHg. In contrast, LMAs from SHR had considerable tone and responded to pressure with vasoconstriction (Figure 1). Dilatory responses were also diminished in LMAs from SHR vs. WKY, including to the voltage operated calcium channel inhibitor diltiazem (63±6% vs. 88±2% at 10 -5 M; p<0.01), the NO donor sodium nitroprusside (23±6% vs. 74±6% at 10 -5 M; p<0.01), and to 15mM KCl that activates inward rectifier K + channels (-5±45% vs. 78±10%; p<0.01). Structurally, passive diameters of LMAs from SHR were smaller but not significantly different from WKY, suggesting therapeutic opening of collaterals may be possible.

Conclusions: The relatively passive nature of LMAs from WKY would be conducive to retrograde flow during MCAO whereas the vasoconstrictive response of LMAs from SHR could limit collateral perfusion. Therapies that alleviate LMA vasoconstriction may help sustain penumbral flow and extend the time for treatment in those patients that have poor collaterals.

Randomized phase II study of axitinib versus placebo plus best supportive care in second-line treatment of advanced hepatocellular carcinoma

BACKGROUND

The efficacy and safety of axitinib, a potent and selective vascular endothelial growth factor receptors 1-3 inhibitor, combined with best supportive care (BSC) was evaluated in a global, randomized, placebo-controlled phase II trial in patients with locally advanced or metastatic hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

Patients with HCC and Child-Pugh Class A who progressed on or were intolerant to one prior antiangiogenic therapy were stratified by tumour invasion (presence/absence of extrahepatic spread and/or vascular invasion) and region (Asian/non-Asian) and randomized (2:1) to axitinib/BSC (starting dose 5 mg twice-daily) or placebo/BSC. The primary end point was overall survival (OS).

RESULTS

The estimated hazard ratio for OS was 0.907 [95% confidence interval (CI) 0.646-1.274; one-sided stratified P = 0.287] for axitinib/BSC (n = 134) versus placebo/BSC (n = 68), with the median (95% CI) of 12.7 (10.2-14.9) versus 9.7 (5.9-11.8) months, respectively. Results of prespecified subgroup analyses in Asian versus non-Asian patients or presence versus absence of tumour invasion were consistent with the overall population. Improvements favouring axitinib/BSC (P < 0.01) were observed in secondary efficacy end point analyses [progression-free survival (PFS), time to tumour progression (TTP), and clinical benefit rate (CBR)], and were retained among Asian patients in the prespecified subgroup analyses. Overall response rate did not differ significantly between treatments and patient-reported outcomes favoured placebo/BSC. Most common all-causality adverse events with axitinib/BSC were diarrhoea (54%), hypertension (54%), and decreased appetite (47%). Baseline serum analyses identified potential new prognostic (interleukin-6, E-selectin, interleukin-8, angiopoietin-2, migration inhibitory factor, and c-MET) or predictive (E-selectin and stromal-derived factor-1) factors for survival.

CONCLUSIONS

Axitinib/BSC did not improve OS over placebo/BSC in the overall population or in stratification subgroups. However, axitinib/BSC resulted in significantly longer PFS and TTP and higher CBR, with acceptable toxicity in patients with advanced HCC.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01210495.

Effect of hypertension and carotid occlusion on brain parenchymal arteriole structure and reactivity

We studied the effect of hypertension and chronic hypoperfusion on brain parenchymal arteriole (PA) structure and function. PAs were studied isolated and pressurized from 18-wk-old Wistar-Kyoto (WKY18; n = 8) and spontaneously hypertensive stroke prone (SHRSP18; n = 8) and 5-wk-old prehypertensive (SHRSP5; n = 8) rats. In separate groups, unilateral common carotid artery occlusion (UCCAo) was performed for 4 wk to cause chronic hypoperfusion in 18-wk-old WKY (WKY18-CH; n = 8) and SHRSP (SHRSP18-CH; n = 8). UCCAo caused PAs to have significantly diminished myogenic tone (31 ± 3 vs. 14 ± 6% at 60 mmHg; P < 0.05) and reactivity to pressure from WKY18-CH vs. WKY18 animals. The effect of UCCAo was limited to normotensive animals, as there was little effect of chronic hypoperfusion on vascular reactivity or percent tone in PAs from SHRSP18 vs. SHRSP18-CH animals (53 ± 4 vs. 41 ± 3%; P > 0.05). However, PAs from SHRSP18 and SHRSP5 animals had significantly greater tone compared with WKY18, suggesting an effect of strain and not hypertension per se on PA vasoconstriction. Structurally, PAs from SHRSP18 and SHRSP5 animals had similar sized lumen diameters, but increased wall thickness and distensibility compared with WKY18. Interestingly, chronic hypoperfusion did not affect the structure of PAs from either WKY18-CH or SHRSP18-CH animals. Thus PAs responded to UCCAo with active vasodilation, but not structural remodeling, an effect that was absent in SHRSP. The increased tone of PAs from SHRSP animals, combined with lack of response to chronic hypoperfusion, may contribute to the propensity for ischemic lesions and increased perfusion deficit during hypertension.

Epidermal growth factor receptor is critical for angiotensin II-mediated hypertrophy in cerebral arterioles

Angiotensin II (Ang II) is a major determinant of vascular remodeling in the cerebral circulation during chronic hypertension, which is an important risk factor for stroke. We examined the molecular mechanism of Ang II-mediated cerebrovascular remodeling that involves the epidermal growth factor receptor (EGFR) pathway. Mutant EGFR mice (waved-2), their heterozygous control (wild-type [WT]), and C57BL/6J mice were infused with Ang II (1000 ng kg(-1) min(-1)) or saline via osmotic minipumps for 28 days (n=8 per group). Eight of the Ang II-infused C57BL/6J mice were cotreated with AG1478 (12 mg/kg per day, IP), a specific EGFR tyrosine kinase inhibitor. Systolic arterial pressure was measured by a tail-cuff method. Pressure and diameter of cerebral arterioles were measured through an open cranial window in anesthetized mice. Cross-sectional area of the wall was determined in pressurized fixed cerebral arterioles. Expression of phosphorylated EGFR (p-EGFR), caveolin-1 (Cav-1), and c-Src was determined by western blotting and immunohistochemistry. Mutation of EGFR or AG1478 treatment did not affect Ang II-induced hypertension. Ang II increased the expression of p-EGFR in WT mice, confirming the activation of EGFR. Ang II induced hypertrophy and inward remodeling of cerebral arterioles in WT mice. Hypertrophy, but not remodeling, was prevented in waved-2 and AG1478-treated C57BL/6J mice. Ang II increased p-EGFR, Cav-1, and c-Src expression in WT but not in waved-2 or AG1478-treated C57BL/6J mice. These results suggest that Ang II-induced hypertrophy in cerebral arterioles involves EGFR-dependent signaling and may include Cav-1 and nonreceptor tyrosine kinase c-Src. This signaling pathway seems to be limited to Ang II-induced hypertrophy, but not inward remodeling, and is independent of blood pressure.

Postischemic reperfusion causes smooth muscle calcium sensitization and vasoconstriction of parenchymal arterioles

BACKGROUND AND PURPOSE

Parenchymal arterioles (PAs) are high-resistance vessels in the brain that connect pial vessels to the microcirculation. We previously showed that PAs have increased vasoconstriction after ischemia and reperfusion that could increase perfusion deficit. Here, we investigated underlying mechanisms by which early postischemic reperfusion causes increased vasoconstriction of PAs.

METHODS

Isolated and pressurized PAs from within the middle cerebral artery territory were studied in male Wistar rats that were either nonischemic control (n=34) or after exposure to transient middle cerebral artery occlusion (MCAO) by filament occlusion for 2 hours with 30 minutes of reperfusion (MCAO; n=38). The relationships among pressure-induced tone, smooth muscle calcium (using Fura 2), and membrane potential were determined. Sensitivity of the contractile apparatus to calcium was measured in permeabilized arterioles using Staphylococcus aureus α-toxin. Reactivity to inhibition of transient receptor potential melastanin receptor type 4 (9-phenanthrol), Rho kinase (Y27632), and protein kinase C (Gö6976) was also measured.

RESULTS

After MCAO, PAs had increased myogenic tone compared with controls (47±2% versus 35±2% at 40 mm Hg; P<0.01), without an increase in smooth muscle calcium (177±21 versus 201±16 nmol/L; P>0.05) or membrane depolarization (-38±4 versus -36±1 mV; P>0.05). In α-toxin-permeabilized vessels, MCAO caused increased sensitivity of the contractile apparatus to calcium. MCAO did not affect dilation to transient receptor potential melastanin receptor type 4 or protein kinase C inhibition but diminished dilation to Rho kinase inhibition.

CONCLUSIONS

The increased vasoconstriction of PAs during early postischemic reperfusion seems to be due to calcium sensitization of smooth muscle and could contribute to infarct expansion and limit neuroprotective agents from reaching their target tissue.

Efficacy and toxicity of intensity-modulated radiation therapy for prostate cancer in Chinese patients

OBJECTIVE

To report the treatment efficacy and toxicity profile of intensitymodulated radiation therapy in Chinese patients with clinically localised prostate cancer.

DESIGN

Historical cohort study.

SETTING

Oncology unit in a university teaching hospital in Hong Kong.

PATIENTS

Patients with clinically localised prostate cancer undergoing intensity-modulated radiation therapy in our institution between May 2001 and November 2009 were reviewed.

MAIN OUTCOME MEASURES

The 5-year biochemical failure–free survival, 5-year overall survival, as well as acute/late gastro-intestinal toxicities and genito-urinary toxicities.

RESULTS

A total of 182 patients were treated with prostate intensitymodulated radiation therapy with or without whole-pelvic radiotherapy. The median follow-up was 44 months. The median patient age was 72 years. Overall survival of the cohort was 92% after 5 years. The favourable, intermediate, and unfavourable risk category distributions of the National Comprehensive Cancer Network were 21 (12%), 42 (23%), and 119 (65%), respectively. The 5-year actuarial biochemical failure–free survival rates for patients in these categories were 95%, 82%, and 80%, respectively. Multivariate analysis identified early tumour stage, low pre-treatment prostate-specific antigen levels, and the use of adjuvant androgen deprivation as independent prognostic factors for better biochemical failure–free survival. Grade 2 and 3 late gastro-intestinal/genito-urinary toxicities occurred in 8%/3% and 4%/3% of the patients, respectively.

CONCLUSION

Intensity-modulated radiation therapy for prostate cancer is feasible and safe in the Chinese population. These data are consistent with the results of other series in Caucasian populations.

Increased pressure-induced tone in rat parenchymal arterioles vs. middle cerebral arteries: role of ion channels and calcium sensitivity

Brain parenchymal arterioles (PAs) are high-resistance vessels that branch off pial arteries and perfuse the brain parenchyma. PAs are the target of cerebral small vessel disease and have been shown to have greater pressure-induced tone at lower pressures than pial arteries. We investigated mechanisms by which brain PAs have increased myogenic tone compared with middle cerebral arteries (MCAs), focusing on differences in vascular smooth muscle (VSM) calcium and ion channel function. The amount of myogenic tone and VSM calcium was measured using Fura 2 in isolated and pressurized PAs and MCAs. Increases in intraluminal pressure caused larger increases in tone and cytosolic calcium in PAs compared with MCAs. At 50 mmHg, myogenic tone was 37 ± 5% for PAs vs. 6.5 ± 4% for MCAs (P < 0.01), and VSM calcium was 200 ± 20 nmol/l in PAs vs. 104 ± 15 nmol/l in MCAs (P < 0.01). In vessels permeabilized with Staphylococcus aureus α-toxin, PAs were not more sensitive to calcium, suggesting calcium sensitization was not at the level of the contractile apparatus. PAs were 30-fold more sensitive to the voltage-dependent calcium channel (VDCC) inhibitor nifedipine than MCAs (EC50 for PAs was 3.5 ± 0.4 vs. 82.1 ± 2.1 nmol/l for MCAs;P < 0.01); however, electrophysiological properties of the VDCC were not different in VSM. PAs had little to no response to the calcium-activated potassium channel inhibitor iberiotoxin, whereas MCAs constricted ∼15%. Thus increased myogenic tone in PAs appears related to differences in ion channel activity that promotes VSM membrane depolarization but not to a direct sensitization of the contractile apparatus to calcium.

Abstract 133: Inhibition of TRPV4 is Protective of the Brain and Cerebral Circulation During Ischemic Stroke

Background: Transient receptor potential vanilloid 4 (TRPV4) channels are highly calcium permeable channels expressed in brain and cerebral endothelium and are regulated by a diverse array of stimuli including shear stress, cell swelling and second messengers. We hypothesized that inhibition of TRPV4 during postischemic reperfusion would be protective of the brain and cerebral endothelium.

Methods: Transient MCAO was used for all experiments. Infarction (by TTC) was measured in TRPV4 knockout mice (n=3) or C57B mice treated upon reperfusion with the TRPV4 inhibitor HC067047 (1mg/kg; n=7) or vehicle (n=8) after 90 minutes of ischemia with 24 hours of reperfusion. To determine the effect of TRPV4 inhibition on BBB permeability, hyperglycemic male Wistar rats (3 days by STZ) were treated with HC067047 (1mg/kg; n=6) or vehicle (n=6) upon reperfusion after 2 hours of ischemia and edema measured at 2 hours by wet:dry weights. Lastly, basal tone of MCAs isolated from male Wistar rats after 2 hours of ischemia with 2 hours of reperfusion (MCAO, n=7) or sham controls (Sham, n=6) was measured before and after addition of HC067047 (1μM) at 75 mmHg.

Results: Infarct volume was significantly reduced in TRPV4 knockout mice and with HC067047 treatment vs. vehicle (17.8 ± 2.8% for KO, 22.9 ± 2.7% for HC067047 vs. 39.8 ± 3.3% for vehicle; p<0.05). Hyperglycemic stroke caused considerable edema formation the ipsilateral vs. contralateral brain in vehicle-treated rats (81.38 ± 0.21% vs. 78.64 ± 0.12%; p<0.01) that was prevented by treatment with HC067047 (78.58 ± 0.22% vs. 78.24 ± 0.11%;p>0.05). MCAO diminished basal tone of MCAs vs. sham (16.3 ± 3.3 vs. 26.4 ± 2.8%; p<0.05) that was restored by HC067047 (25.9 ± 3.0%; p<0.05). The constriction to HC067047 did not occur in MCA that were denuded of endothelium or from sham animals.

Conclusion: These results suggest that postischemic reperfusion activates TRPV4 in cerebral endothelium to cause dilation and BBB permeability. The decreased infarct size after TRPV4 inhibition suggests that activation of TRPV4 during ischemia contributes to neuronal cell death. Thus, inhibition of TRPV4 may be an effective treatment for acute ischemic stroke.

Inhibition of PPARγ during rat pregnancy causes intrauterine growth restriction and attenuation of uterine vasodilation

Decreased peroxisome proliferator-activated receptor gamma (PPARγ) activity is thought to have a major role in preeclampsia through abnormal placental development. However, the role of PPARγ in adaptation of the uteroplacental vasculature that may lead to placental hypoperfusion and fetal growth restriction during pregnancy is not known. Here, pregnant Sprague-Dawley rats (n = 11/group) were treated during the second half of pregnancy with the PPARγ inhibitor GW9662 (10 mg/kg/day in food) or vehicle. Pregnancy outcome and PPARγ mRNA, vasodilation and structural remodeling were determined in maternal uterine and mesenteric arteries. PPARγ was expressed in uterine vascular tissue of both non-pregnant and pregnant rats with ~2-fold greater expression in radial vs. main uterine arteries. PPARγ mRNA levels were significantly higher in uterine compared to mesenteric arteries. GW9662 treatment during pregnancy did not affect maternal physiology (body weight, glucose, blood pressure), mesenteric artery vasodilation or structural remodeling of uterine and mesenteric vessels. Inhibition of PPARγ for the last 10 days of gestation caused decreased fetal weights on both day 20 and 21 of gestation that was associated with impaired vasodilation of radial uterine arteries in response to acetylcholine and sodium nitroprusside. These results define an essential role of PPARγ in the control of uteroplacental vasodilatory function during pregnancy, an important determinant of blood flow to the placenta and fetus. Strategies that target PPARγ activation in the uterine circulation could have important therapeutic potential in treatment of pregnancies complicated by hypertension, diabetes or preeclampsia.

Deficiency of Nox2 prevents angiotensin II-induced inward remodeling in cerebral arterioles

Angiotensin II is an important determinant of inward remodeling in cerebral arterioles. Many of the vascular effects of angiotensin II are mediated by reactive oxygen species (ROS) generated from homologs of NADPH oxidase with Nox2 predominating in small arteries and arterioles. Therefore, we tested the hypothesis that superoxide generated by Nox2 plays a role in angiotensin II-induced cerebral arteriolar remodeling. We examined Nox2-deficient and wild-type (WT) mice in which a pressor or a non-pressor dose of angiotensin II (1000 or 200 ng/kg/day) or saline was infused for 4 weeks via osmotic minipumps. Systolic arterial pressure was measured by a tail-cuff method. Pressure and diameter of cerebral arterioles were measured through an open cranial window in anesthetized mice. Cross-sectional area (by histology) and superoxide level (by hydroethidine staining) of cerebral arterioles were determined ex vivo. The pressor, but not the non-pressor, dose of angiotensin II significantly increased systolic arterial pressure in both WT and Nox2-deficient mice. Both doses of angiotensin II increased superoxide levels and significantly reduced external diameter in maximally dilated cerebral arterioles in WT mice. Increased superoxide and inward remodeling were prevented in Nox2-deficient mice. Moreover, only the pressor dose of AngII increased cross-sectional area of arteriolar wall in WT mice and was prevented in Nox2-deficient mice. In conclusion, superoxide derived from Nox2-containing NADPH oxidase plays an important role in angiotensin II-mediated inward remodeling in cerebral arterioles. This effect appears to be independent of pressure and different from that of hypertrophy.

Treatment for cerebral small vessel disease: effect of relaxin on the function and structure of cerebral parenchymal arterioles during hypertension

We investigated the effect of hypertension on the function and structure of cerebral parenchymal arterioles (PAs), a major target of cerebral small vessel disease (SVD), and determined whether relaxin is a treatment for SVD during hypertension. PAs were isolated from 18-wk-old female normotensive Wistar-Kyoto (WKY) rats, spontaneous hypertensive rats (SHRs), and SHRs treated with human relaxin 2 for 14 d (4 μg/h; n=8/group) and studied using a pressurized arteriograph system. Hypertension reduced PA inner diameter (58±3 vs. 49±3 μm at 60 mmHg in WKY rats, P<0.05), suggesting inward remodeling that was reversed by relaxin (56±4 μm, P<0.05). Relaxin also increased PA distensibility in SHRs (34±2 vs. 10±2% in SHRs, P<0.05). Relaxin was detected in cerebrospinal fluid (110±30 pg/ml) after systemic administration, suggesting that it crosses the blood-brain barrier (BBB). Relaxin receptors (RXFP1/2) were not detected in cerebral vasculature, but relaxin increased vascular endothelial growth factor (VEGF) and matrix metalloproteinase 2 (MMP-2) expression in brain cortex. Inhibition of VEGF receptor tyrosine kinase (axitinib, 4 mg/kg/d, 14 d) had no effect on increased distensibility with relaxin, but caused outward hypertrophic remodeling of PAs from SHRs. These results suggest that relaxin crosses the BBB and activates MMP-2 in brain cortex, which may interact with PAs to increase distensibility. VEGF appears to be involved in remodeling of PAs, but not relaxin-induced increased distensibility.

Anaemia and type 2 diabetes: implications from a retrospectively studied primary care case series

OBJECTIVES. To identify the prevalence of anaemia in Chinese type 2 diabetic patients managed in a primary care setting and to explore its associations with cardiovascular complications and kidney disease. DESIGN. Retrospective case series study. SETTING. General Out-patient Clinic of Hospital Authority, Hong Kong. PATIENTS. Chinese type 2 diabetic patients who had annual assessments between 1 January 2010 and 31 December 2011 were recruited. Their complete blood picture, serum creatinine, estimated glomerular filtration rate (calculated by Modification of Diet in Renal Disease method), haemoglobin A1c, and urine albumin-creatinine ratio were retrieved. Anaemia was defined as a haemoglobin level of <130 g/L in men and <120 g/L in women (World Health Organization criteria). Student's t test and analysis of variance were used to analyse continuous variables and the Chi squared test for categorical data. Pearson's correlation coefficient and multivariate logistic regression were used to examine associations between haemoglobin level and different variables including age, gender, serum creatinine level, estimated glomerular filtration rate, and urine albumin-creatinine ratio. All statistical tests were two-sided, and a P value of <0.05 was considered significant. RESULTS. Among 6325 Chinese type 2 diabetic patients fulfilling the inclusion criteria, 1441 were found to have anaemia with a period prevalence of 22.8%. The prevalence of anaemia increased significantly with deterioration of renal function. Compared with diabetic patients with normal haemoglobin levels, anaemic diabetic patients had a higher co-morbidity rate for stroke, ischaemic heart disease, hypertension, and chronic kidney disease (P<0.001). Independent predictors for haemoglobin level among diabetic patients were age, gender, serum creatinine level, estimated glomerular filtration rate, haemoglobin A1c, and urine albumin-creatinine ratio (P<0.001). Multivariate analysis showed that male gender, old age, increased serum creatinine level, decreased estimated glomerular filtration rate, elevated urine albumin-creatinine ratio, and co-morbidity with stroke or ischaemic heart disease were associated with greater odds for the presence of anaemia. CONCLUSION. Anaemia is common among Chinese type 2 diabetic patients, particularly those with impaired renal function or established cardiovascular disease. Early detection of anaemia and prompt referral to specialist care for optimal treatment, if associated with severe renal impairment or high-risk proteinuria at the primary care settings, is recommended.

Nox2 deficiency prevents hypertension-induced vascular dysfunction and hypertrophy in cerebral arterioles

Oxidative stress is involved in many hypertension-related vascular diseases in the brain, including stroke and dementia. Thus, we examined the role of genetic deficiency of NADPH oxidase subunit Nox2 in the function and structure of cerebral arterioles during hypertension. Arterial pressure was increased in right-sided cerebral arterioles with transverse aortic banding for 4 weeks in 8-week-old wild-type (WT) and Nox2-deficient (-/y) mice. Mice were given N(G)-nitro-L-arginine methyl ester (L-NAME, 10 mg/kg) or vehicle to drink. We measured the reactivity in cerebral arterioles through open cranial window in anesthetized mice and wall cross-sectional area and superoxide levels ex vivo. Aortic constriction increased systolic and pulse pressures in right-sided carotid arteries in all groups of mice. Ethidium fluorescence showed increased superoxide in right-sided cerebral arterioles in WT, but not in Nox2-/y mice. Dilation to acetylcholine, but not sodium nitroprusside, was reduced, and cross-sectional areas were increased in the right-sided arterioles in WT, but were unchanged in Nox2-/y mice. L-NAME reduced dilation to acetylcholine but did not result in hypertrophy in right-sided arterioles of Nox2-/y  mice. In conclusion, hypertension-induced superoxide production derived from Nox2-containing NADPH oxidase promotes hypertrophy and causes endothelial dysfunction in cerebral arterioles, possibly involving interaction with nitric oxide.

Effect of pregnancy and nitric oxide on the myogenic vasodilation of posterior cerebral arteries and the lower limit of cerebral blood flow autoregulation

Hemorrhage during parturition can lower blood pressure beyond the lower limit of cerebral blood flow (CBF) autoregulation that can cause ischemic brain injury. However, the impact of pregnancy on the lower limit of CBF autoregulation is unknown. We measured myogenic vasodilation, a major contributor of CBF autoregulation, in isolated posterior cerebral arteries (PCAs) from nonpregnant and late-pregnant rats (n = 10/group) while the effect of pregnancy on the lower limit of CBF autoregulation was studied in the posterior cerebral cortex during controlled hemorrhage (n = 8). Pregnancy enhanced myogenic vasodilation in PCA and shifted the lower limit of CBF autoregulation to lower pressures. Inhibition of nitric oxide synthase (NOS) prevented the enhanced myogenic vasodilation during pregnancy but did not affect the lower limit of CBF autoregulation. The shift in the autoregulatory curve to lower pressures during pregnancy is likely protective of ischemic injury during hemorrhage and appears to be independent of NOS.

Abstract WP440: Relaxin Selectively Affects Brain Parenchymal Arteriolar Structure during Hypertension

Background: Cerebral small vessel disease (SVD) is a common hypertension-related vasculopathy of the penetrating arterioles (PA) that causes lacunar stroke, white matter lesions and vascular dementia. We investigated the effect of chronic hypertension on PA structure and if treatment with relaxin, a hormone with cardioprotective effects previously shown to promote selective outward remodeling of PA in normotensive animals, could reverse these effects.

Methods: Female SHR rats (n=7-8/group) were treated in vivo with relaxin (4μg/hr) or vehicle for 2 weeks and studied at 18 weeks of age. Aged-matched WKY rats were used as controls. Middle cerebral arteries (MCA) and PA from the same animals were isolated and studied under pressurized conditions in zero calcium buffer to obtain structural measurements. Blood pressures were measured using tail cuff after 3 days of training.

Results: PA inner and outer diameters were smaller in SHR vs. WKY: at 100 mmHg PA inner and outer diameters were 59 ± 3 and 72 ± 3 μm for WKY vs. 50 ± 3 and 63 ± 3 μm for SHR (p<0.01). Relaxin treatment of SHR reversed this rarefaction such that inner and outer diameters were similar to WKY: 58 ± 4 and 69 ± 4 μm (p<0.01 vs. SHR; Figure). The increase in PA size with relaxin treatment was related to a large increase in distensibility (Figure). Percent distensibility of PA for WKY, SHR and SHR+relaxin was: 18 ± 3%, 13 ± 2% and 40 ± 4% (p<0.01). Relaxin treatment had no effect on MCA in SHR that were smaller than WKY: MCA inner and outer diameters were 258 ± 4 and 285 ± 5 μm in WKY, 228 ± 5 and 260 ± 5 μm in SHR and 225 ± 4 and 256 ± 4 μm in SHR+relaxin (p>0.05). Relaxin also did not lower blood pressures that were higher in SHR: MAP for WKY, SHR and SHR+relaxin was: 94 ± 3, 138 ± 2 and 144 ± 5 mmHg (p<0.01 vs. WKY).

Conclusion: These results suggest that relaxin may be an effective treatment for hypertension-induced rarefaction and increased stiffness of PA that underlies SVD in the brain.

Determination of PPARγ activity in adipose tissue and spleen

Peroxisome proliferator-activated receptor-gamma (PPARγ) is a nuclear transcription factor that regulates many genes and is involved in extensive biological functions. Accurately determining PPARγ activity in various tissues is important to understanding mechanisms of human physiology and pathophysiology. Thus, we evaluated a PPARγ DNA binding immunoassay using nuclear extracts of spleen and adipose tissue from rats treated with rosiglitazone (20 mg/kg in food, seven days, n = 6) or vehicle (n = 6) and compared the results to mRNA expression of PPARγ target genes--a well-established method to investigate PPARγ activity. In adipose tissue, the PPARγ immunoassay showed that rosiglitazone did not change PPARγ binding, but qPCR analysis showed that expression of two PPARγ target genes, CD36 and liver X receptor-α, were significantly increased. In spleen, the PPARγ immunoassay showed that rosiglitazone decreased PPARγ binding, but qPCR analysis showed no significant change. The different results obtained between PPARγ binding immunoassay and target gene expression suggest that PPARγ immunoassays may not be suitable when used with fresh homogenates of spleen and adipose tissue. Validation of the assay with each individual tissue is recommended.

Effect of pregnancy on autoregulation of cerebral blood flow in anterior versus posterior cerebrum

Severe preeclampsia and eclampsia are associated with brain edema that forms preferentially in the posterior cerebral cortex possibly because of decreased sympathetic innervation of posterior cerebral arteries and less effective autoregulation during acute hypertension. In the present study, we examined the effect of pregnancy on the effectiveness of cerebral blood flow autoregulation using laser Doppler flowmetry and edema formation by wet:dry weight in acute hypertension induced by phenylephrine infusion in the anterior and posterior cerebrum from nonpregnant (n=8) and late-pregnant (n=6) Sprague-Dawley rats. In addition, we compared the effect of pregnancy on sympathetic innervation by tyrosine hydroxylase staining of posterior and middle cerebral arteries (n=5-6 per group) and endothelial and neuronal NO synthase expression using quantitative PCR (n=3 per group). In nonpregnant animals, there was no difference in autoregulation between the anterior and posterior cerebrum. However, in late-pregnant animals, the threshold of cerebral blood flow autoregulation was shifted to lower pressures in the posterior cerebrum, which was associated with increased neuronal NO synthase expression in the posterior cerebral cortex versus anterior. Compared with the nonpregnant state, pregnancy increased the threshold of autoregulation in both brain regions that was related to decreased expression of endothelial NO synthase. Lastly, acute hypertension during pregnancy caused greater edema formation in both brain cortices that was not attributed to changes in sympathetic innervation. These findings suggest that, although pregnancy shifted the cerebral blood flow autoregulatory curve to higher pressures in both the anterior and posterior cortices, it did not protect from edema during acute hypertension.

A phase II study of concurrent cetuximab-cisplatin and intensity-modulated radiotherapy in locoregionally advanced nasopharyngeal carcinoma

BACKGROUND

Based on our previous work on the clinical activity of cetuximab in recurrent nasopharyngeal carcinoma (NPC), we evaluated the feasibility of adding cetuximab to concurrent cisplatin and intensity-modulated radiotherapy (IMRT) in locoregionally advanced NPC.

PATIENTS AND METHODS

Patients with American Joint Committee on Cancer stage III-IVB NPC were given an initial dose of cetuximab (400 mg/m(2)) 7-10 days before receiving concurrent IMRT, weekly cisplatin (30 mg/m(2)/week) and cetuximab (250 mg/m(2)/week).

RESULTS

Thirty patients (median age of 45 years) with stage III (67%), IVA (30%) and IVB (3%) nonkeratinizing NPC were enrolled. Grade 3-4 oropharyngeal mucositis occurred in 26 (87%) patients and 10 (33%) patients required short-term nasogastric feeding. Grade 3 radiotherapy-related dermatitis occurred in six patients (20%) and three patients (10%) had grade 3 cetuximab-related acneiform rash. These grade 3-4 skin and mucosal toxic effects were manageable and reversible. At a median follow-up of 31.8 months [95% confidence interval (CI) 26.2-32.1 months], the 2-year progression-free survival was 86.5% (95% CI 74.3% to 98.8%).

CONCLUSIONS

Concurrent administration of cetuximab, weekly cisplatin and IMRT is a feasible strategy against locoregionally advanced NPC. Preliminary survival data compare favorably with historic data and further follow-up is warranted.