In RTOG 9704, as previously published, patients with resected pancreatic adenocarcinoma received continuous infusion 5-FU and concurrent radiotherapy (5FU-RT). 5FU-RT treatment was preceded and followed by randomly assigned chemotherapy, either 5-FU or gemcitabine. This analysis explored whether failure to adhere to specified RT guidelines influenced survival and/or toxicity.
Methods and Materials
RT requirements were protocol specified. Adherence was scored as per protocol (PP) or less than per protocol (
RT was scored for 416 patients: 216 PP and 200
This is the first phase III, multi-center, adjuvant protocol for pancreatic adenocarcinoma to evaluate the impact of adherence to specified RT protocol guidelines on protocol outcomes. Failure to adhere to specified RT guidelines was associated with reduced survival and, for patients receiving gemcitabine, trend toward increased non-hematologic toxicity.
Radiotherapy; quality assurance; pancreatic adenocarcinoma; adjuvant therapy; chemoradiotherapy
Group II metabotropic glutamate receptors (mGluR2/3) have emerged as important targets for the treatment of schizophrenia. Since hypofunction of N-methyl-D-aspartate receptors (NMDARs) has also been implicated in the etiology of schizophrenia, we examined whether postsynaptic mGluR2/3 regulate NMDAR function. Activation of mGluR2/3 significantly decreased the ratio of AMPA-to-NMDA excitatory postsynaptic currents at Schaffer Collateral-CA1 synapses and enhanced the peak of NMDA-evoked currents in acutely isolated CA1 neurons. The mGluR2/3-mediated potentiation of NMDAR currents was selective for GluN2A-containing NMDARs and was mediated by the Src family kinase Src. Activation of mGluR2/3 inhibited the adenylyl cyclase-cAMP-PKA pathway and thereby activated Src by inhibiting its regulatory C-terminal Src kinase (Csk). We suggest a novel model of regulation of NMDARs by Gi/o-coupled receptors whereby inhibition of the cAMP-PKA pathway via mGluR2/3 activates Src kinase and potentiates GluN2A-containing NMDAR currents. This represents a potentially novel mechanism to correct the hypoglutamatergic state found in schizophrenia.
Greening of vacant urban land may affect health and safety. The authors conducted a decade-long difference-in-differences analysis of the impact of a vacant lot greening program in Philadelphia, Pennsylvania, on health and safety outcomes. “Before” and “after” outcome differences among treated vacant lots were compared with matched groups of control vacant lots that were eligible but did not receive treatment. Control lots from 2 eligibility pools were randomly selected and matched to treated lots at a 3:1 ratio by city section. Random-effects regression models were fitted, along with alternative models and robustness checks. Across 4 sections of Philadelphia, 4,436 vacant lots totaling over 7.8 million square feet (about 725,000 m2) were greened from 1999 to 2008. Regression-adjusted estimates showed that vacant lot greening was associated with consistent reductions in gun assaults across all 4 sections of the city (P < 0.001) and consistent reductions in vandalism in 1 section of the city (P < 0.001). Regression-adjusted estimates also showed that vacant lot greening was associated with residents’ reporting less stress and more exercise in select sections of the city (P < 0.01). Once greened, vacant lots may reduce certain crimes and promote some aspects of health. Limitations of the current study are discussed. Community-based trials are warranted to further test these findings.
city planning; crime; geography; urban health; urban renewal; wounds and injuries
Lymph node status is an important predictor of survival in pancreatic cancer. We performed a secondary analysis of RTOG 9704, an adjuvant chemotherapy and chemoradiation trial, to determine the influence of lymph node factors-number of positive nodes (NPN), total nodes examined (TNE), and lymph node ratio (LNR-ratio of NPN to TNE)-on OS and disease-free survival (DFS).
Patient and Methods
Eligible patients from RTOG 9704 form the basis of this secondary analysis of lymph node parameters. Actuarial estimates for OS and DFS were calculated using Kaplan-Meier methods. Cox proportional hazards models were performed to evaluate associations of NPN, TNE, and LNR with OS and DFS. Multivariate Cox proportional hazards models were also performed.
There were 538 patients enrolled in the RTOG 9704 trial. Of these, 445 patients were eligible with lymph nodes removed. Overall median NPN was 1 (min-max, 0-18). Increased NPN was associated with worse OS (HR=1.06, p=0.001) and DFS (HR=1.05, p=0.01). In multivariate analyses, both NPN and TNE were associated with OS and DFS. TNE > 12, and >15, were associated with increased OS for all patients, but not for node-negative patients (n =142). Increased LNR was associated with worse OS (HR=1.01, p<0.0001) and DFS (HR=1.006, p=0.002).
In patients who undergo surgical resection followed by adjuvant chemoradiation, TNE, NPN, and LNR are associated with OS and DFS. This secondary analysis of a prospective, cooperative group trial supports the influence of these lymph node parameters on outcomes after surgery and adjuvant therapy using contemporary techniques.
lymph node; nodal ratio; pancreatic cancer; radiation therapy; pancreaticoduodenectomy
The goal of the present study was to determine if there are global or regionally specific decreases in callosal area in early Alzheimer’s disease (AD) and mild cognitive impairment (MCI). In addition, this study examined the corpus callosum of healthy older adults who have subjective cognitive complaints (CC) but perform within normal limits on neuropsychological tests. We used a semi-automated procedure to examine the total and regional areas of the corpus callosum in 22 patients with early AD, 28 patients with amnestic MCI, 28 healthy older adults with cognitive complaints, and 50 demographically matched healthy controls (HC). The AD, MCI, and CC groups all showed a significant reduction of the posterior region (isthmus and splenium) relative to healthy controls. The AD group also had a significantly smaller overall callosum than the controls. The demonstration of callosal atrophy in older adults with cognitive complaints suggests that callosal changes occur very early in the dementing process, and that these earliest changes may be too subtle for detection by neuropsychological assessments, including memory tests.
Alzheimer’s disease; Mild cognitive impairment; Cognitive complaints; Corpus callosum; Magnetic resonance imaging
Glutathione (GSH) plays an important role in neuronal oxidant defence. Depletion of cellular GSH is observed in neurodegenerative diseases and thereby contributes to the associated oxidative stress and Ca2+ dysregulation. Whether depletion of cellular GSH, associated with neuronal senescence, directly influences Ca2+ permeation pathways is not known. Transient receptor potential melastatin type 2 (TRPM2) is a Ca2+ permeable non-selective cation channel expressed in several cell types including hippocampal pyramidal neurons. Moreover, activation of TRPM2 during oxidative stress has been linked to cell death. Importantly, GSH has been reported to inhibit TRPM2 channels, suggesting they may directly contribute to Ca2+ dysregulation associated with neuronal senescence. Herein, we explore the relation between cellular GSH and TRPM2 channel activity in long-term cultures of hippocampal neurons.
In whole-cell voltage-clamp recordings, we observe that TRPM2 current density increases in cultured pyramidal neurons over time in vitro. The observed increase in current density was prevented by treatment with NAC, a precursor to GSH synthesis. Conversely, treatment of cultures maintained for 2 weeks in vitro with L-BSO, which depletes GSH by inhibiting its synthesis, augments TRPM2 currents. Additionally, we demonstrate that GSH inhibits TRPM2 currents through a thiol-independent mechanism, and produces a 3.5-fold shift in the dose-response curve generated by ADPR, the intracellular agonist for TRPM2.
These results indicate that GSH plays a physiologically relevant role in the regulation of TRPM2 currents in hippocampal pyramidal neurons. This interaction may play an important role in aging and neurological diseases associated with depletion of GSH.
TRPM2; Aging; Glutathione; Oxidative stress; Pyramidal neuron; Primary hippocampal culture
Transient receptor potential melastatin 2 (TRPM2) is a calcium permeable non-selective cation channel that functions as a sensor of cellular redox status. Highly expressed within the CNS, we have previously demonstrated the functional expression of these channels in CA1 pyramidal neurons of the hippocampus. Although implicated in oxidative stress-induced neuronal cell death, and potentially in neurodegenerative disease, the physiological role of TRPM2 in the central nervous system is unknown. Interestingly, we have shown that the activation of these channels may be sensitized by co-incident NMDA receptor activation, suggesting a potential contribution of TRPM2 to synaptic transmission. Using hippocampal cultures and slices from TRPM2 null mice we demonstrate that the loss of these channels selectively impairs NMDAR-dependent long-term depression (LTD) while sparing long-term potentiation. Impaired LTD resulted from an inhibition of GSK-3β, through increased phosphorylation, and a reduction in the expression of PSD95 and AMPARs. Notably, LTD could be rescued in TRPM2 null mice by recruitment of GSK-3β signaling following dopamine D2 receptor stimulation. We propose that TRPM2 channels play a key role in hippocampal synaptic plasticity.
TRPM2; GSK-3β; PSD-95; Long term depression; Metaplasticity; NMDA Receptors; AMPA Receptors
Futhan is a serine protease inhibitor and medicine in the treatment of disseminated intravascular coagulation (DIC) and acute pancreatitis. It is metabolized quickly in vivo. Here we show that Futhan reversibly inhibits NMDA receptors in hippocampal neurons and GABAA receptors both in hippocampal neurons and in A549 cells, a human alveolar epithelial cell line. The effect of Futhan on GABAA receptors in A549 cells is much more potent than its effect on GABAA receptors in hippocampal neurons (IC50: 0.9 μM V.S. 7.3 μM). Since GABAA receptors are also expressed in various non-neuronal tissues, particularly in airway epithelia and GABA promotes mucus production during asthma, our findings indicate that Futhan may be developed as a novel aerosolized therapeutic to treat asthma through blocking GABAA receptors in the lung.
Asthma; GABAA receptors; NMDA receptors; Futhan; ion channels
The built environment can constrain or facilitate physical activity. Most studies of the health consequences of the built environment suffer from problems of selection bias associated with confounding effects of residential choice and transportation decisions.
To examine the cross-sectional associations between objective and perceived measures of the built environment, BMI, obesity (BMI>30 kg/m2), and meeting weekly recommended physical activity (RPA) levels through walking and vigorous exercise. To assess effect of using light rail transit system (LRT) on changes in BMI, obesity, and meeting weekly RPA levels.
Data were collected on individuals before (July 2006–February of 2007) and after (March 2008–July 2008) completion of a light rail system in Charlotte, NC. BMI, obesity, and physical activity levels were calculated for a comparison of these factors pre- and post-LRT construction. A propensity score weighting approach adjusted for differences in baseline characteristics among LRT and non-LRT users. Data were analyzed in 2009.
More positive perceptions of one’s neighborhood at baseline were associated with a −0.36 (p<.05) lower BMI, 15% lower odds (95% CI=0.77, 0.94) of obesity, 9% higher odds (95% CI = 0.99, 1.20) of meeting weekly RPA through walking, and 11% higher odds (95% CI= 1.01, 1.22) of meeting RPA levels of vigorous exercise. The use of light rail transit to commute to work was associated with an average −1.18 reduction in BMI (p<0.05) and an 81% reduced odds (95% CI= 0.04, 0.92) of becoming obese over time.
The results of this study suggest that improving neighborhood environments and increasing the public’s use of LRT systems could provide improvements in health outcomes for millions of individuals.
Together, acid-sensing ion channels (ASICs) and epithelial sodium channels (ENaC) constitute the majority of voltage-independent sodium channels in mammals. ENaC is regulated by a chloride channel, the cystic fibrosis transmembrane conductance regulator (CFTR). Here we show that ASICs were reversibly inhibited by activation of GABAA receptors in murine hippocampal neurons. This inhibition of ASICs required opening of the chloride channels but occurred with both outward and inward GABAA receptor-mediated currents. Moreover, activation of the GABAA receptors modified the pharmacological features and kinetic properties of the ASIC currents, including the time course of activation, desensitization and deactivation. Modification of ASICs by open GABAA receptors was also observed in both nucleated patches and outside-out patches excised from hippocampal neurons. Interestingly, ASICs and GABAA receptors interacted to regulate synaptic plasticity in CA1 hippocampal slices. The activation of glycine receptors, which are similar to GABAA receptors, also modified ASICs in spinal neurons. We conclude that GABAA receptors and glycine receptors modify ASICs in neurons through mechanisms that require the opening of chloride channels.
The primary objective of this trial was to evaluate the response rate for trimetrexate (TMTX) in conjunction with 5FU and leucovorin (LV) (=TFL) in the treatment of advanced gastric cancer in a phase II, cooperative group setting.
Patients with locally advanced, unresectable, or metastatic adenocarcinoma of the stomach received TMTX 110 mg/m2 IV over 60 minutes day 1, followed by 5-FU 500 mg/m2 IV bolus and LV 200 mg/m2 IV over 60 minutes day 2, followed by oral LV 15 mg every 6 hours × 7 doses, all weekly for 6 weeks followed by 2 weeks of rest, continued until progression.
Characteristics for 37 eligible patients: median age 63 (range 23 to 83); male/female: 69%/31%; performance status 0/1/2 15/20/1. The confirmed response rate was 19%, and median overall survival was 6 months. Two patients died as a result of therapy, one due to infection without significant neutropenia, and one due to perforation of a responding gastric lesion. 72% experienced Grades 3 and 4 toxicity, most commonly diarrhea, fatigue, and lymphopenia.
This regimen achieves response rates comparable to other 5FU-based regimens, when used in treatment of incurable gastric cancer. Toxicity appears manageable.
trimetrexate; chemotherapy; gastric neoplasms
Combination of chemotherapeutic agents and angiogenesis inhibitors is now commonly employed in the clinic to treat cancer. Here, we used angiostatic agents anginex and 0118, in combination with the chemotherapeutic irofulven, to treat human ovarian tumor xenografts in mice. General linear mixed models were used to statistically analyze tumor growth curves. Overall, combination of a low, non-toxic dose of irofulven with either angiogenesis inhibitor was more effective at inhibiting tumor growth than any of the single-agent therapies. For example, the anginex/irofulven and 0118/irofulven combinations inhibited tumor growth relative to controls by 92% (p<0.0001) and 96% (p<0.0001), respectively, with the 0118/irofulven combinations yielding 100% complete responses. This study suggests that combination therapy of 0118 or anginex and irofulven may be highly effective in the clinical setting.
anginex; irofulven; galectin-1; angiogenesis; chemotherapy
Concentrations of extracellular divalent cations (Ca2+ and Mg2+) fall substantially during intensive synaptic transmission as well as during some pathophysiological conditions such as epilepsy and brain ischemia. Here we report that a synthetic serine protease inhibitor, nafamostat mesylate (NM), and several of its analogues, block recombinant TRPM7 currents expressed in HEK293T cells in inverse relationship to the concentration of extracellular divalent cations. Lowering extracellular Ca2+ and Mg2+ also evokes a divalent-sensitive non-selective cation current that is mediated by TRPM7 expression in hippocampal neurons. In cultured hippocampal neurons, NM blocked these TRPM7-mediated currents with an apparent affinity of 27 μM, as well as the paradoxical Ca2+ influx associated with lowering extracellular Ca2+. Unexpectedly, pre-exposure to NM strongly potentiated TRPM7 currents. In the presence of physiological concentrations of extracellular divalent cations, NM activates TRPM7. The stimulating effects of NM on TRPM7 currents are also inversely related to extracellular Ca2+ and Mg2+. DAPI and HSB but not netropsin, blocked and stimulated TRPM7. In contrast, mono-cationic, the metabolites of NM, p-GBA and AN, as well as protease inhibitor leupeptin and gabexate failed to substantially modulate TRPM7. NM thus provides a molecular template for the design of putative modulators of TRPM7.
Vasoactive intestinal peptide (VIP) is a 28 amino acid peptide which belongs to a superfamily of structurally related peptide hormones including pituitary adenylate cyclase-activating polypeptide (PACAP). Although several studies have identified the involvement of PACAP in learning and memory, little work has been done to investigate such a role for VIP. At least three receptors for VIP have been identified including the PACAP receptor (PAC1-R) and the two VIP receptors (VPAC receptors). VIP can activate the PAC1-R only if it is used at relatively high concentrations (e.g. 100 nM); however, at lower concentrations (e.g. 1 nM) it is selective for the VPAC receptors. Our lab has showed that PAC1-R activation signals through PKC/CAKβ/Src pathway to regulate NMDA receptors, however there is little known about the potential regulation of NMDA receptors by VPAC receptors. Our studies demonstrated that application of 1nM VIP enhanced NMDA currents by stimulating VPAC receptors as the effect was blocked by VPAC receptor antagonist [Ac-Tyr1, D-Phe2]GRF (1–29). This enhancement of NMDA currents was blocked by both Rp-cAMPS and PKI14–22 (they are highly specific PKA inhibitors), but not by the specific PKC inhibitor, bisindolylmaleimide I. In addition, the VIP-induced enhancement of NMDA currents was accentuated by inhibition of phosphodiesterase 4, which inhibits the degradation of cAMP. This regulation of NMDA receptors also required the scaffolding protein AKAP. In contrast, the potentiation induced by high concentration of VIP (e.g. 100 nM) was mediated by PAC1-R as well as by Src kinase. Overall, these results show that VIP can regulate NMDA receptors through different receptors and signaling pathways.
VIP; NMDA receptor; cAMP/PKA; VPAC receptor; AKAP
The tyrosine kinase Pyk2 plays a unique role in intracellular signal transduction by linking Ca2+ influx to tyrosine phosphorylation, but the molecular mechanism of Pyk2 activation is unknown. We report that Pyk2 oligomerization by antibodies in vitro or overexpression of PSD-95 in PC6-3 cells induces trans-autophosphorylation of Tyr402, the first step in Pyk2 activation. In neurons, Ca2+ influx through NMDA-type glutamate receptors (NMDAR) causes postsynaptic clustering and autophosphorylation of endogenous Pyk2 via Ca2+- and calmodulin-stimulated binding to PSD-95. Accordingly, Ca2+ influx promotes oligomerization and thereby autoactivation of Pyk2 by stimulating its interaction with PSD-95. We show that this mechanism of Pyk2 activation is critical for LTP in the hippocampus CA1 region, which is thought to underlie learning and memory.
Pyk2; PSD-95; Calmodulin; hippocampus; long-term potentiation; NMDA receptor