In vivo electrophysiology of nigral and thalamic neurons in alpha-synuclein-overexpressing mice highlights differences from toxin-based models of parkinsonism.

Numerous studies have suggested that alpha-synuclein plays a prominent role in both familial and idiopathic Parkinson's disease (PD). Mice in which human alpha-synuclein is overexpressed (ASO) display progressive motor deficits and many nonmotor features of PD. However, it is unclear what in vivo pathophysiological mechanisms drive these motor deficits. It is also unknown whether previously proposed pathophysiological features (i.e., increased beta oscillations, bursting, and synchronization) described in toxin-based, nigrostriatal dopamine-depletion models are also present in ASO mice. To address these issues, we first confirmed that 5- to 6-mo-old ASO mice have robust motor dysfunction, despite the absence of significant nigrostriatal dopamine degeneration. In the same animals, we then recorded simultaneous single units and local field potentials (LFPs) in the substantia nigra pars reticulata (SNpr), the main basal ganglia output nucleus, and one of its main thalamic targets, the ventromedial nucleus, as well as LFPs in the primary motor cortex in anesthetized ASO mice and their age-matched, wild-type littermates. Neural activity was examined during slow wave activity and desynchronized cortical states, as previously described in 6-hydroxydopamine-lesioned rats. In contrast to toxin-based models, we found a small decrease, rather than an increase, in beta oscillations in the desynchronized state. Similarly, synchronized burst firing of nigral neurons observed in toxin-based models was not observed in ASO mice. Instead, we found more subtle changes in pauses of SNpr firing compared with wild-type control mice. Our results suggest that the pathophysiology underlying motor dysfunction in ASO mice is distinctly different from striatal dopamine-depletion models of parkinsonism.

Prospective, randomized, double-blind, multi-center, Phase III clinical study on transarterial chemoembolization (TACE) combined with Sorafenib versus TACE plus placebo in patients with hepatocellular cancer before liver transplantation - HeiLivCa [ISRCTN24081794].

BACKGROUND: Disease progression of hepatocellular cancer (HCC) in patients eligible for liver transplantation (LTx) occurs in up to 50% of patients, resulting in withdrawal from the LTx waiting list. Transarterial chemoembolization (TACE) is used as bridging therapy with highly variable response rates. The oral multikinase inhibitor sorafenib significantly increases overall survival and time-to-progression in patients with advanced hepatocellular cancer. DESIGN: The HeiLivCa study is a double-blinded, controlled, prospective, randomized multi-centre phase III trial. Patients in study arm A will be treated with transarterial chemoembolization plus sorafenib 400 mg bid. Patients in study arm B will be treated with transarterial chemoembolization plus placebo. A total of 208 patients with histologically confirmed hepatocellular carcinoma or HCC diagnosed according to EASL criteria will be enrolled. An interim patients' analysis will be performed after 60 events. Evaluation of time-to-progression as primary endpoint (TTP) will be performed at 120 events. Secondary endpoints are number of patients reaching LTx, disease control rates, OS, progression free survival, quality of live, toxicity and safety. DISCUSSION: As TACE is the most widely used primary treatment of HCC before LTx and sorafenib is the only proven effective systemic treatment for advanced HCC there is a strong rational to combine both treatment modalities. This study is designed to reveal potential superiority of the combined TACE plus sorafenib treatment over TACE alone and explore a new neo-adjuvant treatment concept in HCC before LTx.