Citations

Abstract Background This study aimed to have international experts converge on a harmonized definition of whole hippocampus boundaries and segmentation procedures, to define standard operating procedures for magnetic resonance (MR)‐based manual hippocampal segmentation. Methods The panel received a questionnaire regarding whole hippocampus boundaries and segmentation procedures. Quantitative information was supplied to allow evidence‐based answers. A recursive and anonymous Delphi procedure was used to achieve convergence. Significance of agreement among panelists was assessed by exact probability on Fisher's and binomial tests. Results Agreement was significant on the inclusion of alveus/fimbria ( P = .021), whole hippocampal tail ( P = .013), medial border of the body according to visible morphology ( P = .0006), and on this combined set of features ( P = .001). This definition captures 100% of hippocampal tissue, 100% of Alzheimer’s disease‐related atrophy, and demonstrated good reliability on preliminary intrarater (0.98) and inter‐rater (0.94) estimates. Discussion Consensus was achieved among international experts with respect to hippocampal segmentation using MR resulting in a harmonized segmentation protocol.

Abstract Janus kinase-2 (JAK2)/STAT pathway activation is commonly observed in myeloproliferative neoplasms and plays an important role in disease development and progression. The V617F activating mutation in the JAK2 pseudokinase domain is found in 95% of patients with polycythemia vera (PV) and in 50-70% of patients with primary myelofibrosis (MF) or essential thrombocythemia (ET). Studies have shown the clinical efficacy of JAK2 inhibitors in treating MF in terms of a reduction in splenomegaly and relief of constitutional symptoms. A reduction in the JAK2V617F allele burden after treatment with a JAK2-targeted agent could be a surrogate for a disease-modifying effect of this therapy. To demonstrate this, a robust method that can accurately measure the JAK2V617F allele burden is required. Here, we report the development of a sensitive quantitative PCR (qPCR) assay to determine the JAK2V617F allele burden in patients treated with SAR302503, the validation of the assay in a Phase 0 clinical study and implementation in a phase II study using samples from patients with MF. The assay demonstrated robust performance, with high sensitivity (LLOD=0.05% and LLOQ=0.5%) and accuracy. A phase 0 study in MF, PV, and ET patients showed that (1) there was minimal intra-subject sampling variability in JAK2V617F allele burden, and (2) whole-blood samples are stable for at least 48 hours at ambient conditions for DNA preparation without a significant impact on JAK2V617F allele burden measurement.Of the 31 patients with intermediate-2 or high-risk MF enrolled in a phase II clinical study (NCT01420770), baseline samples were available for 29 patients and of these, 26 were JAK2V617F-positive using this assay. Of the 19/26 patients for whom samples were available at all 3 time points, the median allele burden was 93% at baseline, 87% at the end of Cycle 3, and 78% at the end of Cycle 6. Among the 24 patients who were JAK2V617F-positive and for whom spleen measurements were available at the end of Cycle 6, a total of 15 (63%) had a spleen response (≥ 35% reduction in spleen volume by MRI versus baseline). In contrast, two JAK2V617F-negative patients did not have a spleen response. Patients with baseline allele burden levels of 0 to <25%, 25% to 75%, and ≥75% showed spleen response rates of 50%, 44%, and 69%, respectively, at the end of Cycle 6. JAK2V617F allele burden will continue to be assessed every 3 cycles. Longer follow up is needed to determine the clinical effect of allele burden reduction. Citation Format: Feng Liu, Moshe Talpaz, Animesh Pardanani, Catriona Jamieson, Nashat Gabrail, Ayalew Tefferi, Tianlei Lei, Rita Greco, Francisco Adrian, Nikki Daskalakis, Claudia Lebedinsky, Pamela Cohen, Donald Bergstrom. Determination of JAK2V617F allele burden in a phase II study of patients with myelofibrosis treated with SAR302503 using a sensitive and robust allele-specific qPCR assay. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-294. doi:10.1158/1538-7445.AM2013-LB-294

Abstract Mesenchymal stem cells (MSC) represent a new tool for delivery of therapeutic agents to cancer sites because of their strong tropism toward tumors. IL15 has demonstrated a potent antitumor activity in various animal models as well as clinical trials. However, because of its short half-life, effective therapeutic effects usually require a high dose, which often results in undesired side effects; thus, new strategies for overcoming this disadvantage are needed. In this study, human MSCs were isolated from umbilical cord blood as delivery vehicles and transduced with lentivirus vector expressing murine IL15 (MSC-IL15). In vitro assays of lymphocyte activation and proliferation demonstrated that IL15 produced by MSCs was biofunctional. In syngeneic mice bearing Pan02 pancreatic tumors, systemic administration of MSC-IL15 significantly inhibited tumor growth and prolonged the survival of tumor-bearing mice, which were associated with tumor cell apoptosis, and natural killer (NK)– and T-cell accumulation. Furthermore, we confirmed that MSC-IL15 could migrate toward tumor and secreted IL15 in tumor-specific sites. Depletion of NK and CD8+ T cells abolished the antitumor activity of MSC-IL15, suggesting that NK and CD8+ T cells play a key role for MSC-IL15–mediated effect. Interestingly, cured mice after MSC-IL15 treatment were resistant to Pan02 pancreatic tumor rechallenge, and adoptive transfer of lymphocytes from cured mice also could cause rejection of Pan02 tumor inoculation in naïve mice, indicating that MSC-IL15 induced tumor-specific T-cell immune memory response. Overall, these data support that MSCs producing IL15 might represent an innovative strategy for therapy of pancreatic tumor. Mol Cancer Ther; 13(8); 2127–37. ©2014 AACR.

Key points A CO‐dependent transwall gradient of resting membrane potential exists across the circular muscle layer in the gastrointestinal tract; this gradient regulates the strength of phasic muscle contraction during electrical slow wave activity. H2S, CO and NO are endogenously generated in the muscle layers of the gut wall. Inhibiting the H2S producing enzyme CSE with the CSE inhibitor PAG had no significant effect on transwall resting membrane potential gradient in control preparations but significantly shifted the entire gradient in the depolarizing direction in preparations pretreated with the NO synthase (NOS) inhibitor l‐NNA. PAG significantly shifted the gradient in the depolarizing direction in mouse preparations lacking neuronal NOS (nNOS‐KO) and the gradient was significantly shifted in the depolarizing direction in mouse preparations lacking both nNOS and CSE (CSE‐KO–nNOS‐KO). NO production was significantly higher in CSE‐KO mouse preparations compared to wild‐type mouse preparations and the amplitude of NO‐mediated slow inhibitory junction potentials (S‐IJPs) was significantly higher in CSE‐KO mouse preparations compared to the amplitude of S‐IJPs in wild‐type mouse preparations. Nearly all submucosal neurons and myenteric neurons were CSE positive and 11% of submucosal neurons and 50% of myenteric neurons were nNOS positive. Our novel findings suggested that endogenous H2S is a stealth hyperpolarizing factor on smooth muscle cells and that endogenous H2S inhibits NO production from nNOS. AbstractA transwall gradient in resting membrane potential (RMP) exists across the circular muscle layer in the mouse colon. This gradient is dependent on endogenous generation of CO. H2S is also generated in muscle layers of the mouse colon. The effect of endogenously generated H2S on the transwall gradient is not known. The aim was to investigate the role of endogenous H2S. Our results showed that the CSE inhibitor dl‐propargylglycine (PAG, 500 μm) had no effect on the transwall gradient. However, in preparations pretreated with the nitric oxide synthase inhibitor N‐nitro‐l‐arginine (l‐NNA, 200 μm) and in nNOS‐knockout (KO) mouse preparations, PAG shifted the transwall gradient in the depolarizing direction. In CSE‐KO–nNOS‐KO mice, the gradient was shifted in the depolarizing direction. Endogenous generation of NO was significantly higher in muscle preparations of CSE‐KO mice compared to wild‐type (WT) mice. The amplitude of NO‐mediated slow inhibitory junction potentials (S‐IJPs) evoked by electric field stimulation was significantly higher in CSE‐KO mouse preparations compared to the amplitude of S‐IJPs in wild‐type mouse preparations. CSE was present in all submucosal ganglion neurons and in almost all myenteric ganglion neurons. Eleven per cent of CSE positive neurons in the submucosal plexus and 50% of CSE positive neurons in the myenteric plexus also contained nNOS. Our results suggest that endogenously generated H2S acts as a stealth hyperpolarizing factor on smooth muscle cells to maintain the CO‐dependent transwall gradient and inhibits NO production from nNOS.

Key PointsPhenotypic and genotypic profiling of MDM2 in DLBCL. MDM2 as a negative regulator of p53 tumor suppressor function.

Genetic College Many genomic elements in humans are associated with behavior, including educational attainment. In a genome-wide association study including more than 100,000 samples, Rietveld et al. (p. 1467 , published online 30 May; see the Perspective by Flint and Munafò ) looked for genes related to educational attainment in Caucasians. Small genetic effects at three loci appeared to impact educational attainment.

Objectives To assess the safety and efficacy of tadalafil once daily on lower urinary tract symptoms suggestive of clinical benign prostatic hyperplasia ( BPH‐LUTS ) in men without erectile dysfunction ( ED ). To compare these with effects in men with ED . Patients and Methods After a 4‐week washout period and 4‐week placebo run‐in period, 1089 men without ED ( n = 338) and with ED ( n = 751) were randomly assigned to placebo or tadalafil 5 mg once daily for 12 weeks in three global clinical studies with similar designs. In the pooled dataset, post hoc analyses of covariance assessed the impact and severity of BPH‐LUTS using the I nternational P rostate S ymptom S core ( IPSS ) and the BPH I mpact I ndex ( BII ) and IPSS quality‐of‐life ( IPSS ‐ QoL ) subscores. Safety was assessed using treatment‐emergent adverse events. The treatment‐by‐ ED ‐status interaction was used to assess efficacy differences between the with/without ED subgroups. Results Men without ED were similar in BPH‐LUTS severity/previous therapy to men with ED . Tadalafil significantly reduced BPH‐LUTS from baseline when compared with placebo in men without ED ( IPSS −5.4 vs −3.3, P < 0.01; IPSS voiding subscore −3.5 vs −2.0, P < 0.01; IPSS storage subscore −1.9 vs −1.3, P < 0.05). Tadalafil also significantly improved quality of life from baseline when compared with placebo in men without ED ( IPSS ‐ QoL −1.0 vs −0.7, BII −1.4 vs −1.0; both P < 0.05). Between‐ ED ‐subgroup interactions were not significant (all P > 0.68). Tadalafil was safe and well tolerated. Conclusion Tadalafil 5 mg once daily improved BPH‐LUTS in men without ED by a magnitude similar to that observed in men with ED . The adverse event profile in men without ED was consistent with that observed in men with ED .

PurposeTo investigate the feasibility of using MR elastography (MRE) for the evaluation of the stiffness of in vivo aortic wall.Materials and MethodsTo validate the experimental approach for imaging the aorta in vivo, a gel phantom with an embedded porcine aorta was imaged in the presence of fluid flow within the aorta. The potential changes in the elasticity of the vessel wall with changes in pressure were investigated. The feasibility of performing MRE of abdominal aorta was assessed in five volunteers (age, 22–40 years; body mass index, 21.5–25.2 kg/m2). The pulse‐gated cine MRE technique was used to study the wave propagation along the aorta throughout the cardiac cycle and provide estimates of aortic stiffness in diastole.ResultsIn the phantom study, the wave propagation was well visualized within the porcine aorta embedded in the gel phantom. An increase of the Young's modulus‐wall thickness (E*t) product with the increase in static pressure was observed. In the in vivo study, the waves were well visualized within the lumen of abdominal aorta in the five volunteers in diastolic phase, but they were not well visualized during systole.ConclusionMRE is feasible for noninvasively assessing the stiffness of the abdominal aorta and merits further investigation. J. Magn. Reson. Imaging 2013;38:1549–1553. © 2013 Wiley Periodicals, Inc.