Heatwave-induced synchrony within forage fish portfolio disrupts energy flow to top pelagic predators.

During the Pacific marine heatwave of 2014-2016, abundance and quality of several key forage fish species in the Gulf of Alaska were simultaneously reduced throughout the system. Capelin (Mallotus catervarius), sand lance (Ammodytes personatus), and herring (Clupea pallasii) populations were at historically low levels, and within this community abrupt declines in portfolio effects identify trophic instability at the onset of the heatwave. Although compensatory changes in age structure, size, growth or energy content of forage fish were observed to varying degrees among all these forage fish, none were able to fully mitigate adverse impacts of the heatwave, which likely included both top-down and bottom-up forcing. Notably, changes to the demographic structure of forage fish suggested size-selective removals typical of top-down regulation. At the same time, changes in zooplankton communities may have driven bottom-up regulation as copepod community structure shifted toward smaller, warm water species, and euphausiid biomass was reduced owing to the loss of cold-water species. Mediated by these impacts on the forage fish community, an unprecedented disruption of the normal pelagic food web was signaled by higher trophic level disruptions during 2015-2016, when seabirds, marine mammals, and groundfish experienced shifts in distribution, mass mortalities, and reproductive failures. Unlike decadal-scale variability underlying ecosystem regime shifts, the heatwave appeared to temporarily overwhelm the ability of the forage fish community to buffer against changes imposed by warm water anomalies, thereby eliminating any ecological advantages that may have accrued from having a suite of coexisting forage species with differing life-history compensations.

Twelve tips for interpreting abdominal CT scans.

BACKGROUND: Abdominal computerised tomography (CT) scans are a crucial tool in the diagnosis and management of the acute abdomen. Currently, medical students are not widely and extensively trained in the interpretation of abdominal scans. AIM: We aim to provide advice about interpreting abdominal CT scans. METHODS: We used the critical reflection of our experiences, both in clinical practice and in teaching, alongside advice from the literature to develop these tips. RESULTS: Twelve tips following the '4As, 3Bs, 2Cs and 1D' approach are presented to assist doctors and medical students with interpreting abdominal CT scans. CONCLUSION: The early identification of pathology on CT scans has been demonstrated to improve patient outcomes in certain cases, while a formal radiologist's report is awaited. Following a systematic approach, such as the one we presented here, may aid trainees in looking at abdominal CT scans.

Regulation of gene transcription by thyroid hormone receptor ß agonists in clinical development for the treatment of non-alcoholic steatohepatitis (NASH).

Thyroid hormones are important modulators of metabolic activity in mammals and alter cholesterol and fatty acid levels through activation of the nuclear thyroid hormone receptor (THR). Currently, there are several THRß agonists in clinical trials for the treatment of non-alcoholic steatohepatitis (NASH) that have demonstrated the potential to reduce liver fat and restore liver function. In this study, we tested three THRß-agonism-based NASH treatment candidates, GC-1 (sobetirome), MGL-3196 (resmetirom), and VK2809, and compared their selectivity for THRß and their ability to modulate the expression of genes specific to cholesterol and fatty acid biosynthesis and metabolism in vitro using human hepatic cells and in vivo using a rat model. Treatment with GC-1 upregulated the transcription of CPT1A in the human hepatocyte-derived Huh-7 cell line with a dose-response comparable to that of the native THR ligand, triiodothyronine (T3). VK2809A (active parent of VK2809), MGL-3196, and VK2809 were approximately 30-fold, 1,000-fold, and 2,000-fold less potent than T3, respectively. Additionally, these relative potencies were confirmed by quantification of other direct gene targets of THR, namely, ANGPTL4 and DIO1. In primary human hepatocytes, potencies were conserved for every compound except for VK2809, which showed significantly increased potency that was comparable to that of its active counterpart, VK2809A. In high-fat diet fed rats, a single dose of T3 significantly reduced total cholesterol levels and concurrently increased liver Dio1 and Me1 RNA expression. MGL-3196 treatment resulted in concentration-dependent decreases in total and low-density lipoprotein cholesterol with corresponding increases in liver gene expression, but the compound was significantly less potent than T3. In conclusion, we have implemented a strategy to rank the efficacy of THRß agonists by quantifying changes in the transcription of genes that lead to metabolic alterations, an effect that is directly downstream of THR binding and activation.

Latest Advances in Small Molecule TLR 7/8 Agonist Drug Research.

Toll-like receptors (TLRs) 7 and 8 play an important role in the activation of innate immune cells in mammals. These evolutionarily conserved receptors serve as important sentinels in response to infection. Activation of TLRs 7 and 8 triggers induction of a Th1 type innate immune response. The emergence of new structural and small molecule information generated in the last decade has contributed enormously to our understanding of this highly sophisticated process of innate immunity signaling. This review will focus on recent developments in the small molecule activation of TLR 7 and 8.

Design, Synthesis, and Biological Evaluation of Novel Indoles Targeting the Influenza PB2 Cap Binding Region.

In the search for novel influenza inhibitors we evaluated 7-fluoro-substituted indoles as bioisosteric replacements for the 7-azaindole scaffold of Pimodivir, a PB2 (polymerase basic protein 2) inhibitor currently in clinical development. Specifically, a 5,7-difluoroindole derivative 11a was identified as a potent and metabolically stable influenza inhibitor. 11a demonstrated a favorable oral pharmacokinetic profile and in vivo efficacy in mice. In addition, it was found that 11a was not at risk of metabolism via aldehyde oxidase, an advantage over previously described inhibitors of this class. The crystal structure of 11a bound to influenza A PB2 cap region is disclosed here and deposited to the PDB.

Prostate-Specific Antigen After Neoadjuvant Androgen Suppression in Prostate Cancer Patients Receiving Short-Term Androgen Suppression and External Beam Radiation Therapy: Pooled Analysis of Four NRG Oncology Radiation Therapy Oncology Group Randomized Clinical Trials.

PURPOSE: To validate whether prostate-specific antigen (PSA) level after neoadjuvant androgen suppression (neoAS) is associated with long-term outcome after neoAS and external beam radiation therapy (RT) with concurrent short-term androgen suppression (AS) in patients with prostate cancer. METHODS AND MATERIALS: This study included 2404 patients. The patients were treated with neoAS before RT and concurrent AS (without post-RT AS) and were pooled from NRG Oncology/RTOG trials 9202, 9408, 9413, and 9910. Multivariable models were used to test associations between the prespecified dichotomized post-neoAS, pre-RT PSA level (≤0.1 vs >0.1 ng/mL) groupings, and clinical outcomes. RESULTS: The median follow-up for surviving patients was 9.4 years. The median post-neoAS, pre-RT PSA level was 0.3 ng/mL, with 32% of patients having levels ≤0.1 ng/mL. Race, Gleason score, tumor stage, node stage, pretreatment PSA level, and duration of neoAS were associated with the groups of patients with PSA levels ≤0.1 and >0.1 ng/mL. In univariate analyses, post-neoAS, pre-RT PSA level >0.1 ng/mL was associated with increased risks of biochemical failure (hazard ratio [HR], 2.04; P < .0001); local failure (HR, 2.51; P < .0001); distant metastases (HR, 1.73; P = .0006); cause-specific mortality (HR, 2.36; P < .0001); and all-cause mortality (HR, 1.24; P = .005). In multivariable models that also included baseline and treatment variables, post-neoAS, pre-RT PSA level >0.1 ng/mL was independently associated with increased risk of biochemical failure (HR, 2.00; P < .0001); local failure (HR, 2.33; P < .0001); and cause-specific mortality (HR, 1.75; P = .03). CONCLUSIONS: Patients with a PSA level >0.1 ng/mL after neoAS and before the start of RT had less favorable clinical outcomes than patients whose PSA level was ≤0.1 ng/mL. The role of post-neoAS, pre-RT PSA level relative to PSA levels obtained along the continuum of medical care is not presently defined but could be tested in future clinical trials.

Design and synthesis of tetrahydropyridopyrimidine based Toll-Like Receptor (TLR) 7/8 dual agonists.

In a continuing effort to discover novel TLR agonists, herein we report on the discovery and structure-activity relationship of novel tetrahydropyridopyrimidine TLR 7/8 agonists. Optimization of this series towards dual agonist activity and a high clearance profile resulted in the identification of compound 52a1. Evaluation in vivo revealed an interferon stimulated response (ISG) in mice with limited systemic exposure and demonstrated the potential in antiviral treatment or as a vaccine adjuvant.

2,4-Diaminoquinazolines as Dual Toll-like Receptor (TLR) 7/8 Modulators for the Treatment of Hepatitis B Virus.

A novel series of 2,4-diaminoquinazolines was identified as potent dual Toll-like receptor (TLR) 7 and 8 agonists with reduced off-target activity. The stereochemistry of the amino alcohol was found to influence the TLR7/8 selectivity with the ( R) isomer resulting in selective TLR8 agonism. Lead optimization toward a dual agonist afforded ( S)-3-((2-amino-8-fluoroquinazolin-4-yl)amino)hexanol 31 as a potent analog, being structurally different from previously described dual agonists ( McGowan J. Med. Chem. 2016 , 59 , 7936 ). Pharmacokinetic and pharmacodynamic (PK/PD) studies revealed the desired high first pass profile aimed at limiting systemic cytokine activation. In vivo pharmacodynamic studies with lead compound 31 demonstrated production of cytokines consistent with TLR7/8 activation in mice and cynomolgus monkeys and ex vivo inhibition of hepatitis B virus (HBV).

Discovery of selective 2,4-diaminoquinazoline toll-like receptor 7 (TLR 7) agonists.

The discovery of a novel series of highly potent quinazoline TLR 7/8 agonists is described. The synthesis and structure-activity relationship is presented. Structural requirements and optimization of this series toward TLR 7 selectivity afforded the potent agonist 48. Pharmacokinetic and pharmacodynamic studies highlighted 48 as an orally available endogenous interferon (IFN-α) inducer in mice.

Serum testosterone changes in patients treated with radiation therapy alone for prostate cancer on NRG oncology RTOG 9408.

OBJECTIVES: We reviewed testosterone changes for patients who were treated with radiation therapy (RT) alone on NRG oncology RTOG 9408. METHODS AND MATERIALS: Patients (T1b-T2b, prostate-specific antigen <20 ng/mL) were randomized between RT alone and RT plus 4 months of androgen ablation. Serum testosterone (ST) levels were investigated at enrollment, RT completion, and the first follow-up 3 months after RT. The Wilcoxon signed rank test was used to compare pre- and post-treatment ST levels in patients who were randomized to the RT-alone arm. RESULTS: Of 2028 patients enrolled, 992 patients were randomized to receive RT alone and 917 (92.4%) had baseline ST values available and completed RT. Of these 917 patients, immediate and 3-month post-RT testosterone levels were available for 447 and 373 patients, respectively. Excluding 2 patients who received hormonal therapy off protocol after RT, 447 and 371 patients, respectively, were analyzed. For all patients, the median change in ST values at completion of RT and at 3-month follow-up were -30.0 ng/dL (p5-p95; -270.0 to 162.0; P < .001) and -34.0 ng/dL (p5-p95, -228.0 to 160.0; P < .01), respectively. CONCLUSION: RT for prostate cancer was associated with a median 9.2% decline in ST at completion of RT and a median 9.3% decline 3 months after RT. These changes were statistically significant.

Characterization of a dengue NS4B inhibitor originating from an HCV small molecule library.

Dengue is the most important mosquito-transmitted viral disease and a major global health concern. Over the last decade, dengue virus (DENV) drug discovery and development has intensified, however, this has not resulted in approved DENV-specific antiviral treatments yet. DENV and hepatitis C virus (HCV) belong to the same Flaviviridae family and, in contrast to DENV, antiviral treatments for HCV have been licensed. Therefore, applying the knowledge gained on anti-HCV drugs may foster the discovery and development of dengue antiviral drugs. Here, we screened a library of compounds with established anti-HCV activity in a DENV-2 sub-genomic replicon inhibition assay and selected compounds with single-digit micromolar activity. These compounds were advanced into a hit-to-lead medicinal chemistry program resulting in lead compound JNJ-1A, which inhibited the DENV-2 sub-genomic replicon at 0.7 µM, in the absence of cytotoxicity. In addition, JNJ-1A showed equipotent antiviral activity against DENV serotypes 1, 2, and 4. In vitro resistance selection experiments with JNJ-1A induced mutation T108I in non-structural protein 4B (NS4B), pointing towards a mechanism of action linked to this protein. Collectively, we described the discovery and characterization of a novel DENV inhibitor potentially targeting NS4B.

Identification and Optimization of Pyrrolo[3,2-d]pyrimidine Toll-like Receptor 7 (TLR7) Selective Agonists for the Treatment of Hepatitis B.

Pyrrolo[3,2-d]pyrimidines were identified as a new series of potent and selective TLR7 agonists. Compounds were optimized for their activity and selectivity over TLR8. This presents an advantage over recently described scaffolds that have residual TLR8 activity, which may be detrimental to the tolerability of the candidate drug. Oral administration of the lead compound 54 effectively induced a transient interferon stimulated gene (ISG) response in mice and cynomolgus monkeys. We aimed for a high first pass effect, limiting cytokine induction systemically, and demonstrated the potential for the immunotherapy of viral hepatitis.

Synthesis and evaluation of novel HCV replication inhibitors.

Direct acting antiviral agents to cure hepatitis C virus (HCV) infection has emerged as the gold standard therapy. Along with protease inhibitors, nucleoside polymerase inhibitors and non-nucleoside polymerase inhibitors, the inhibition of NS5a has proved to be an effective way to treat HCV patients. Here we report on novel HCV NS5a inhibitors which were synthesized and evaluated in the HCV replicon assay. A series of inhibitors were formed by a cycloaddition reaction in parallel to establish new leads and explore the effects of unsymmetrical cap substitution. This led to the identification of several triazoles with picomolar potency in vitro against hepatitis C virus.

Novel Pyrimidine Toll-like Receptor 7 and 8 Dual Agonists to Treat Hepatitis B Virus.

Toll-like receptor (TLR) 7 and 8 agonists can potentially be used in the treatment of viral infections and are particularly promising for chronic hepatitis B virus (HBV) infection. An internal screening effort identified a pyrimidine Toll-like receptor 7 and 8 dual agonist. This provided a novel alternative over the previously reported adenine and pteridone type of agonists. Structure-activity relationship, lead optimization, in silico docking, pharmacokinetics, and demonstration of ex vivo and in vivo cytokine production of the lead compound are presented.

Cardiovascular Mortality Following Short-term Androgen Deprivation in Clinically Localized Prostate Cancer: An Analysis of RTOG 94-08.

BACKGROUND: Androgen deprivation therapy (ADT) is associated with coronary heart disease and diabetes in men with prostate cancer (PCa); however, controversy exists regarding ADT and cardiovascular mortality (CVM) with limited data for lower risk disease. OBJECTIVE: We conducted a hypothesis-generating retrospective analysis to evaluate the relationship between short-course ADT and CVM in patients with clinically localized PCa enrolled in a phase III trial. DESIGN, SETTING, AND PARTICIPANTS: A total of 1979 men with clinically localized (T1b-2b, prostate-specific antigen [PSA] <20 ng/ml) PCa enrolled in Radiation Therapy Oncology Group (RTOG) 94-08 from 1994 to 2001. Patients were randomized to radiation therapy (RT) with or without short-course ADT (4 mo of gonadotropin-releasing hormone (GnRH) agonist therapy and antiandrogen). Median follow-up was 9.1 yr for survivors. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The Cox proportional hazards model assessed overall survival. The Fine-Gray proportional hazards model assessed disease-specific survival (DSS) and CVM. Covariates included age, race, weight, baseline cardiovascular disease, baseline diabetes, baseline hypertension, Gleason score, T stage, and PSA. RESULTS AND LIMITATIONS: Short-course ADT improved overall survival and DSS and was not associated with an increased risk of CVM. Overall, 191 cardiovascular-related deaths were observed. At 10 yr, 83 patients (cumulative incidence rate: 10%) receiving RT and ADT versus 95 patients (cumulative incidence rate: 11%) receiving RT alone experienced CVM. The treatment arm was not associated with increased CVM (unadjusted hazard ratio: 1.07; confidence interval, 0.81-1.42; p=0.62). Increased CVM was not observed in patients at low risk of PCa death or at high risk of cardiac-related death. CONCLUSIONS: Data from patients enrolled in RTOG 94-08 support the hypothesis that ADT does not increase CVM risk in men with clinically localized PCa treated with short-course GnRH agonist therapy. These data support ADT use in settings with proven survival benefit. PATIENT SUMMARY: We investigated the controversial relationship between hormone therapy and cardiovascular mortality in men with prostate cancer (PCa) treated with radiation in a large randomized trial. Our data suggest that hormone therapy does not increase the risk of cardiovascular death in patients with clinically localized PCa and support the use of such therapy in settings with proven survival benefit.

Versatile Multicomponent Reaction Macrocycle Synthesis Using α-Isocyano-ω-carboxylic Acids.

The direct macrocycle synthesis of α-isocyano-ω-carboxylic acids via an Ugi multicomponent reaction is introduced. This multicomponent reaction (MCR) protocol differs by being especially short, convergent, and versatile, giving access to 12-22 membered rings.

Importance of Local Control in Early-Stage Prostate Cancer: Outcomes of Patients With Positive Post-Radiation Therapy Biopsy Results Treated in RTOG 9408.

PURPOSE: The purpose of this study was to assess the association between positive post-radiation therapy (RT) biopsy results and subsequent clinical outcomes in males with localized prostate cancer. METHODS AND MATERIALS: Radiation Therapy Oncology Group study 94-08 analyzed 1979 males with prostate cancer, stage T1b-T2b and prostate-specific antigen concentrations of ≤ 20 ng/dL, to investigate whether 4 months of total androgen suppression (TAS) added to RT improved survival compared to RT alone. Patients randomized to receive TAS received flutamide with luteinizing hormone releasing hormone (LHRH) agonist. According to protocol, patients without evidence of clinical recurrence or initiation of additional endocrine therapy underwent repeat prostate biopsy 2 years after RT completion. Statistical analysis was performed to evaluate the impact of positive post-RT biopsy results on clinical outcomes. RESULTS: A total of 831 patients underwent post-RT biopsy, 398 were treated with RT alone and 433 with RT plus TAS. Patients with positive post-RT biopsy results had higher rates of biochemical failure (hazard ratio [HR] = 1.7; 95% confidence interval [CI] = 1.3-2.1) and distant metastasis (HR = 2.4; 95% CI = 1.3-4.4) and inferior disease-specific survival (HR = 3.8; 95% CI = 1.9-7.5). Positive biopsy results remained predictive of such outcomes after correction for potential confounders such as Gleason score, tumor stage, and TAS administration. Prior TAS therapy did not prevent elevated risk of adverse outcome in the setting of post-RT positive biopsy results. Patients with Gleason score ≥ 7 with a positive biopsy result additionally had inferior overall survival compared to those with a negative biopsy result (HR = 1.56; 95% CI = 1.04-2.35). CONCLUSIONS: Positive post-RT biopsy is associated with increased rates of distant metastases and inferior disease-specific survival in patients treated with definitive RT and was associated with inferior overall survival in patients with high-grade tumors.