Supra-additive Effect Research Articles

Low-to-moderate alcohol consumption is associated with increased fibrosis in individuals with metabolic dysfunction-associated steatotic liver disease

Both metabolic dysfunction and alcohol consumption cause steatotic liver disease (SLD). The distinction between metabolic dysfunction-associated SLD (MASLD) and MetALD categories is based on arbitrary thresholds of alcohol intake. Thus, we assessed the impact of different levels of alcohol consumption on SLD severity and their interaction with metabolic comorbidities. We performed a population-based study with transient elastography (FibroScan®) data from participants in Spain (derivation cohort) and the US (validation cohort). A controlled attenuation parameter ≥275dB/m was used to define SLD. At least one cardiometabolic risk factor was required to define MASLD. Among patients with MASLD, low alcohol consumption was defined as an average of 5-9 drinks/week, moderate consumption as 10-13 drinks/week for females and 10-20 drinks/week for males, and increased alcohol intake (MetALD) as 14-35 drinks/week for females and 21-42 drinks/week for males. Significant fibrosis was defined as a liver stiffness measurement ≥8kPa and at-risk metabolic dysfunction-associated steatohepatitis (MASH) as a FAST score ≥0.35. The derivation cohort included 2,227 individuals with MASLD (9% reported low, 14% moderate alcohol consumption) and 76 cases with MetALD. Overall prevalences of significant fibrosis and at-risk MASH were 7.6% and 14.8%, respectively. In the multivariable analysis, alcohol consumption was independently associated with significant fibrosis and at-risk MASH. A dose-dependent increase in the prevalence of significant fibrosis and at-risk MASH was observed between the number of drinks/week and the number of cardiometabolic factors. The validation cohort included 1,732 participants with MASLD, of whom 17% had significant fibrosis and 13% at-risk MASH. This cohort validated the association between moderate intake and MASLD at risk of progression (odds ratio 1.69, 95% CI 1.06-2.71). Moderate alcohol intake is commonly seen in MASLD and increases the risk of advanced disease to a level similar to that observed in MetALD. Metabolic risk factors such as overweight, diabetes or dyslipidemia, and alcohol consumption can cause liver disease. These factors frequently coexist, but their joint effects on liver fibrosis remain uncertain. In this study, we have analyzed individuals from the general population with MASLD (metabolic dysfunction-associated steatotic liver disease) enrolled in Spain and the US. We show that moderate alcohol consumption has a supra-additive effect with metabolic risk factors, exponentially increasing the risk of liver fibrosis. These results suggest that there are no safe limits of daily alcohol intake in patients with unhealthy metabolic status and MASLD.

Additive effects of emotional expression and stimulus size on the perception of genuine and artificial facial expressions: an ERP study

Seeing an angry individual in close physical proximity can not only result in a larger retinal representation of that individual and an enhanced resolution of emotional cues, but may also increase motivation for rapid visual processing and action preparation. The present study investigated the effects of stimulus size and emotional expression on the perception of happy, angry, non-expressive, and scrambled faces. We analyzed event-related potentials (ERPs) and behavioral responses of N = 40 participants who performed a naturalness classification task on real and artificially created facial expressions. While the emotion-related effects on accuracy for recognizing authentic expressions were modulated by stimulus size, ERPs showed only additive effects of stimulus size and emotional expression, with no significant interaction with size. This contrasts with previous research on emotional scenes and words. Effects of size were present in all included ERPs, whereas emotional expressions affected the N170, EPN, and LPC, irrespective of size. These results imply that the decoding of emotional valence in faces can occur even for small stimuli. Supra-additive effects in faces may necessitate larger size ranges or dynamic stimuli that increase arousal.

Non-additive effect: Variation in the effects of the interaction between primitive components in anaerobic digestion

Inherent characteristics of complex organic components and their interactive coupling with environmental factors limit the comprehensive understanding of biotransformation in anaerobic digestion. In this study, we elucidated the mechanism underlying an interesting phenomenon, where a non-additive effect for methane production was recorded when primitive components, i.e., alpha-cellulose (α-CE), xylan (XY), and alkali lignin (AL), were used. The interaction of α-CE and XY produced a supra-additive effect due to the reduction of the energy barrier of carbonyl compound degradation. The degradation of non-conjugated CO, with lower kinetic stability, was preferred to the degradation of conjugated CO. The introduction of AL produced a sub-additive effect, and AL exerted a stronger inhibitory effect on the methanogenesis of XY than α-CE. The preferential change in the relevant structural units occurred due to the deposition of AL on the surface of XY or the wrapping of XY by AL. In this study, we described a multiphase integrated influence mechanism, which can be used to more effectively design anaerobic co-digestion strategies and achieve the controlled enhancement of methane yield of perishable organic solid waste.

Combining Cisplatin with Different Radiation Qualities-Interpretation of Cytotoxic Effects In Vitro by Isobolographic Analysis.

The combination of platinum-containing cytostatic drugs with different radiation qualities has been studied for years. Despite their massive side effects, these drugs still belong to the therapeutic portfolio in cancer treatment. To overcome the disadvantages of cisplatin, our study investigated the cytotoxic effects of combining radionuclides with cisplatin. FaDu cells were treated with cisplatin (concentration ≈ 2 µM) and additionally irradiated after two hours with the alpha-emitter 223Ra, the beta-emitter 188Re as well as external X-rays using dose ranges of 2-6 Gy. Cell survival was followed by colony formation assays and plotted against cisplatin concentration and radiation dose. The results were interpreted by isobolograms. Isobolographic analyses revealed a supra-additive cytotoxic effect for the combination of cisplatin and 223Ra. A sub-additive effect was observed for the combination of cisplatin and 188Re, whereas a protective effect was found for the combination with X-rays. The combination of cisplatin and 223Ra may have the potential to create a successfully working therapy scheme for various therapy approaches, whereas the combination with 188Re as well as single-dose X-ray treatment did not lead to a detectable radiosensitizing effect. Thus, the combination with alpha-emitters might be advantageous and, therefore, should be followed in future studies when combined with cytostatic drugs.

Targeting Mutant KRAS with Novel Mutant-Specific Pharmacological Inhibitors: Activity Against Myeloma and Other Lymphoid Malignant Cells and Molecular Mechanisms of Resistance

Oncogenic RAS mutations are frequent genomic drivers in hematologic neoplasias such as multiple myeloma (MM) but are traditionally considered non-“druggable”. Novel specific inhibitors of G12C and G12D KRAS mutants are clinically active in solid tumors, but their impact on KRAS-mutant lymphoid malignancies has not been explored. Here, we examined the activity of these inhibitors against G12C/D KRAS-mutant cells from MM, B-ALL and T-ALL; the functional sequelae of pharmacological KRAS inhibition; and the potential mechanisms of resistance to these agents. We assessed the activity of novel G12C- (MRTX1257) and G12D- (MRTX1133) specific pharmacological KRAS inhibitors against 2 MM lines with G12C (KHM1B, XG7) and 2 with G12D (KARPAS620, KP6) KRAS mutations; as well as the G12D mutant KOPN-8 (B-ALL) and CCRF-CEM (T-ALL) lines. KRAS inhibitors were tested at concentration ranges achievable in patients with solid tumors. Potent and mutant-specific activity was achieved with both of these KRAS inhibitors in their respective lines, with IC50 in the range of 5-150 nM after 3-7d treatment. This level of in vitro activity was similar to KRAS-mutant lines (e.g., in our in vitro studies and also in the literature) from solid tumors that are clinically responsive to these agents. Furthermore, the KRAS inhibitors effectively abrogated downstream MAPK and AKT pathway activation (e.g. phosphorylation of ERK or AKT by immunoblotting). MRTX1133 led to potent induction of cell death of KARPAS620, KP6 and KOPN8 cells (flow cytometry for Annexin V/PI staining) while MRTX1257 induced cell death in KHM1B and had a predominantly cytostatic effect on XG7 cells. Combinations of MRTX1257 with clinically established anti-MM drugs (incl. melphalan, bortezomib, pomalidomide, trametinib) caused in some cases supra-additive effects, but - more importantly - showed no antagonism with any combination. RNA sequencing revealed that KRAS inhibitor treatment downregulated RAS effector genes (e.g., ETV4, ETV5), and negative regulators of RAS signaling (e.g., DUSP6, SPRY4 reflecting a RAS-driven negative feedback loop controlling expression of these genes), and molecules involved in cell cycle regulation (e.g., D-type cyclin), anti-apoptosis, and DNA replication/repair. Conversely, KRAS inhibition upregulated genes involved in cell cycle arrest and stress responses. Importantly, we performed genome-scale CRISPR activation studies in 4 MM lines with G12C/G12D mutant KRAS to identify genes whose gain-of-function (GOF) enhances or suppresses MM cell response to the respective KRAS inhibitors. Top “hits” from these screens were validated with individual sgRNAs. CRISPR activation of mutant KRAS itself promotes MM cell escape from treatment, likely due to stoichiometric reasons and decreased target saturation at a given drug concentration. Notably, CRISPR activation of positive regulators of RAS-MAPK signaling (e.g., SHOC2), and upstream surface receptors (e.g., EGFR) were among top genes mediating KRAS inhibitor resistance. Beyond KRAS itself, these top “hit” genes are typically not recurrently mutated, amplified, differentially expressed (e.g., compared with normal plasma cells) in MM and are not associated with “high-risk” clinical behavior. Some (e.g., EGFR) of the genes identified from these CRISPR studies are not typically expressed in MM cells at diagnosis, thus these results outline how ectopic expression (e.g., EGFR) or overexpression of these “hit” genes could represent candidate biomarkers for decreased response or early relapse in future clinical studies of KRAS inhibitors in KRAS-mutant MM. Ongoing studies are addressing how these genomic perturbations may affect the in vivo response of KRAS-mutant cells to KRAS inhibitors alone or in combinations with established therapies. Our study documents that novel KRAS G12C and G12D inhibitors exhibit potent and mutant-specific activity against MM and other lymphoid malignant cells at dose levels that are clinically achievable in solid tumor patients. This study also provides functional evidence about genes and molecular pathways that regulate MM cell sensitivity vs. resistance to KRAS inhibitors. These results create a framework for ongoing and future efforts to translate the use of KRAS inhibitors into clinical studies for MM and other lymphoid malignancies.

Evaluation of prothrombotic risk of two PROC hotspot mutations (Arg189Trp and Lys193del) in Chinese population: a retrospective study

BackgroundR189W and K193del of protein C (PC) were hotspot mutations in Chinese population with venous thromboembolism (VTE), but almost two-thirds of patients with above mutations coexisting with other genetically or aquiredly prothrombotic risk factors. The aim of this study is to clarify the independent contributions of R189W or K193del to VTE risk.Methods490 unrelated patients with a personal history of VTE and 410 healthy participants were enrolled in this study. Data of their demographics, family history, genetic and acquired thrombosis risk factors were collected and statistically analyzed.ResultsPC R189W and K193del were identified in 3/410 (0.7%) and 7/410 (1.7%) healthy controls, and in 27/490 (5.5%) and 43/490 (8.8%) patients with VTE, respectively. Notably, about 70% of these mutant carriers combined with other genetic or acquired thrombophilic factors. After adjustment for age, gender, other inherited and acquired risk factors, we demonstrated that R189W and K193del were associated with 5.781-fold and 4.365-fold increased risk of VTE, respectively, which were significantly lower than the prothrombotic risk of anticoagulant deficiencies induced from rare mutations. Independent R189W or K193del mutation was not associated with earlier first-onset age as well as higher recurrent rate of VTE. However, combination of other genetic or acquired thrombophilic factors had supra-additive effects on those consequences. The more additional risk factors the patients had, the younger first-onset ages and higher risk of recurrence would be.ConclusionsAs the most frequent mutations for PC deficiency in Chinese population, both R189W and K193del mutations had limited independent contributions to VTE development compared with other rare mutations in PROC gene, but may act in concert with other genetic defects or acquired thrombotic risk factors to produce the final severe phenotype.

Waist-hip ratio is superior to BMI in predicting liver-related outcomes and synergizes with harmful alcohol use

Background:Obesity is associated with liver disease, but the best obesity-related predictor remains undefined. Controversy exists regarding possible synergism between obesity and alcohol use for liver-related outcomes (LRO). We assessed the predictive performance for LROs, and synergism with alcohol use, of abdominal obesity (waist-hip ratio, WHR), and compared it to overall obesity (body mass index, BMI).Methods:Forty-thousand nine-hundred twenty-two adults attending the Finnish health-examination surveys, FINRISK 1992–2012 and Health 2000 studies, were followed through linkage with electronic healthcare registries for LROs (hospitalizations, cancers, and deaths). Predictive performance of obesity measures (WHR, waist circumference [WC], and BMI) were assessed by Fine-Gray models and time-dependent area-under-the-curve (AUC).Results:There are 355 LROs during a median follow-up of 12.9 years (509047.8 person-years). WHR and WC emerge as more powerful predictors of LROs than BMI. WHR shows significantly better 10-year AUC values for LROs (0.714, 95% CI 0.685–0.743) than WC (0.648, 95% CI 0.617–0.679) or BMI (0.550, 95% CI 0.514–0.585) both overall and separately among men and women. WHR is predictive also in BMI strata. Absolute 10-year risks of LROs are more dependent on WHR than BMI. Moreover, WHR shows a significant supra-additive interaction effect with harmful alcohol use for liver-related outcomes (excess 10-year cumulative incidence of 2.8% from the interaction), which is not seen between BMI and harmful alcohol use.Conclusions:WHR is a better predictor than BMI or WC for LROs, and WHR better reflects the synergism with harmful alcohol use. WHR should be included in clinical assessment when evaluating obesity-related risks for liver outcomes.

Supra-additive effect of chronic inflammation and atherogenic dyslipidemia on developing type 2 diabetes among young adults: a prospective cohort study

BackgroundBoth elevated inflammation and atherogenic dyslipidemia are prominent in young-onset diabetes and are increasingly identified as biologically intertwined processes that contribute to diabetogenesis. We aimed to investigate the age-specific risks of type 2 diabetes (T2D) upon concomitant chronic inflammation and atherogenic dyslipidemia.MethodsAge-stratified Cox regression analysis of the risk of incident diabetes upon co-exposure to time-averaged cumulative high-sensitivity C-reactive protein (CumCRP) and atherogenic index of plasma (CumAIP) among 42,925 nondiabetic participants from a real-world, prospective cohort (Kailuan Study).ResultsDuring a median 6.41 years of follow-up, 3987 T2D developed. Isolated CumAIP and CumCRP were significantly associated with incident T2D in the entire cohort and across all age subgroups. Both CumAIP and CumCRP were jointly associated with an increased risk of diabetes (P-interaction = 0.0126). Compared to CumAIP < -0.0699 and CumCRP < 1 mg/L, co-exposure to CumAIP ≥ − 0.0699 and CumCRP ≥ 3 mg/L had a significant hazard ratio (HR) [2.55 (2.23–2.92)] after adjusting for socio-demographic, life-style factors, family history of diabetes, blood pressure, renal function and medication use. The co-exposure-associated risks varied greatly by age distribution (P-interaction = 0.0193): < 40 years, 6.26 (3.47–11.28); 40–49 years, 2.26 (1.77–2.89); 50–59 years, 2.51 (2.00–3.16); 60–69 years, 2.48 (1.86–3.30); ≥ 70 years, 2.10 (1.29–3.40). In young adults (< 45 years), both exposures had a significant supra-additive effect on diabetogenesis (relative excess risk due to interaction: 0.80, 95% CI 0.10–1.50).ConclusionsThese findings highlight the need for age-specific combined assessment and management of chronic inflammation and dyslipidemia in primary prevention against T2D, particularly for young adults. The clinical benefit derived from dual-target intervention against dyslipidemia and inflammation will exceed the sum of each part alone in young adults.

Combined effect of high factor VIII levels and high mean platelet volume on the risk of future incident venous thromboembolism

BackgroundHigh factor VIII (FVIII) levels and large platelets, as reflected by a high mean platelet volume (MPV), are separately associated with increased risk of venous thromboembolism (VTE). Whether the combination of high FVIII levels and large platelets has a supra-additive effect on VTE risk is unknown. ObjectivesWe aimed to investigate the joint effect of high FVIII levels and large platelets, as reflected by high MPV, on the risk of future incident VTE. MethodsA population-based nested case-control study with 365 incident VTE cases and 710 controls was derived from the Tromsø study. FVIII antigen levels and MPV were measured in blood samples drawn at baseline. Odds ratios with 95% CIs were estimated across FVIII tertiles (<85%, 85%-108%, and ≥108%) and within predefined MPV strata (<8.5, 8.5-9.5, and ≥9.5 fL). ResultsVTE risk increased linearly across FVIII tertiles (Ptrend < .001) in models adjusted for age, sex, body mass index, and C-reactive protein. In the combined analysis, participants with FVIII levels in the highest tertile and an MPV of ≥9.5 fL (ie, joint exposure) had an odds ratio for VTE of 2.71 (95% CI, 1.44-5.11) compared with those with FVIII levels in the lowest tertile and an MPV of <8.5 fL (reference). In the joint exposure group, 52% (95% CI, 17%-88%) of VTEs were attributable to the biological interaction between FVIII and MPV. ConclusionOur results suggest that large platelets, as reflected by high MPV, might play a role in the mechanism by which high FVIII level increases the risk of incident VTE.

Behavioral effects of triazolam and pregnanolone combinations: reinforcing and sedative-motor effects in female rhesus monkeys.

Benzodiazepines (BZs) are prescribed as anxiolytics, but their use is limited by side effects including abuse liability and daytime drowsiness. Neuroactive steroids are compounds that, like BZs, modulate the effects of GABA at the GABAA receptor. In a previous study, combinations of the BZ triazolam and neuroactive steroid pregnanolone produced supra-additive (i.e., greater than expected effects based on the drugs alone) anxiolytic effects but infra-additive (i.e., lower than expected effects based on the drugs alone) reinforcing effects in male rhesus monkeys, suggestive of an improved therapeutic window. Female rhesus monkeys (n=4) self-administered triazolam, pregnanolone, and triazolam-pregnanolone combinations intravenously under a progressive-ratio schedule. In order to assess characteristic sedative-motor effects of BZ-neuroactive steroid combinations, female rhesus monkeys (n=4) were administered triazolam, pregnanolone, and triazolam-pregnanolone combinations. Trained observers, blinded to condition, scored the occurrence of species-typical and drug-induced behaviors. In contrast to our previous study with males, triazolam-pregnanolone combinations had primarily supra-additive reinforcing effects in three monkeys but infra-additive reinforcing effects in one monkey. Scores for deep sedation (i.e., defined as atypical loose-limbed posture, eyes closed, does not respond to external stimuli) and observable ataxia (any slip, trip, fall, or loss of balance) were significantly increased by both triazolam and pregnanolone. When combined, triazolam-pregnanolone combinations had supra-additive effects for inducing deep sedation, whereas observable ataxia was attenuated, likely due to the occurrence of robust sedative effects. These results suggest that significant sex differences exist in self-administration of BZ-neuroactive steroid combinations, with females likely to show enhanced sensitivity to reinforcing effects compared with males. Moreover, supra-additive sedative effects occurred for females, demonstrating a higher likelihood of this adverse effect when these drug classes are combined.

Ketoprofen, lysine and gabapentin co-crystal magnifies synergistic efficacy and tolerability of the constituent drugs: Pre-clinical evidences towards an innovative therapeutic approach for neuroinflammatory pain

Chronic pain is an enormous public health concern, and its treatment is still an unmet medical need. Starting from data highlighting the promising effects of some nonsteroidal anti-inflammatory drugs in combination with gabapentin in pain treatment, we sought to combine ketoprofen lysine salt (KLS) and gabapentin to obtain an effective multimodal therapeutic approach for chronic pain. Using relevant in vitro models, we first demonstrated that KLS and gabapentin have supra-additive effects in modulating key pathways in neuropathic pain and gastric mucosal damage. To leverage these supra-additive effects, we then chemically combined the two drugs via co-crystallization to yield a new compound, a ternary drug-drug co-crystal of ketoprofen, lysine and gabapentin (KLS-GABA co-crystal). Physicochemical, biodistribution and pharmacokinetic studies showed that within the co-crystal, ketoprofen reaches an increased gastrointestinal solubility and permeability, as well as a higher systemic exposure in vivo compared to KLS alone or in combination with gabapentin, while both the constituent drugs have increased central nervous system permeation. These unique characteristics led to striking, synergistic anti-nociceptive and anti-inflammatory effects of KLS-GABA co-crystal, as well as significantly reduced spinal neuroinflammation, in translational inflammatory and neuropathic pain rat models, suggesting that the synergistic therapeutic effects of the constituent drugs are further boosted by the co-crystallization. Notably, while strengthening the therapeutic effects of ketoprofen, KLS-GABA co-crystal showed remarkable gastrointestinal tolerability in both inflammatory and chronic neuropathic pain rat models. In conclusion, these results allow us to propose KLS-GABA co-crystal as a new drug candidate with high potential clinical benefit–to–risk ratio for chronic pain treatment.

The interaction effect of transfusion history and previous stroke history on the risk of venous thromboembolism in stroke patients: a prospective cohort study

BackgroundBlood transfusion and previous stroke history are two independent risk factors of venous thromboembolism (VTE) in stroke patients. Whether the potential interaction of transfusion history and previous stroke history is associated with a greater risk of VTE remains unclear. This study aims to explore whether the combination of transfusion history and previous stroke history increases the risk of VTE among Chinese stroke patients.MethodsA total of 1525 participants from the prospective Stroke Cohort of Henan Province were enrolled in our study. Multivariate logistic regression models were used to explore the associations among transfusion history, previous stroke history and VTE. The interaction was evaluated on both multiplicative and additive scales. The odds ratio (95% CI), relative excess risk of interaction (RERI), attributable proportion (AP), and synergy index (S) of interaction terms were used to examine multiplicative and additive interactions. Finally, we divided our population into two subgroups by National Institutes of Health Stroke Scale (NIHSS) score and re-evaluated the interaction effect in both scales.ResultsA total of 281 (18.4%) participants of 1525 complicated with VTE. Transfusion and previous stroke history were associated with an increased risk of VTE in our cohort. In the multiplicative scale, the combination of transfusion and previous stroke history was statistically significant on VTE in both unadjusted and adjusted models (P<0.05). For the additive scale, the RERI shrank to 7.016 (95% CI: 1.489 ~ 18.165), with the AP of 0.650 (95% CI: 0.204 ~ 0.797) and the S of 3.529 (95% CI: 1.415 ~ 8.579) after adjusting for covariates, indicating a supra-additive effect. In subgroups, the interaction effect between transfusion history and previous stroke history was pronouncedly associated with the increased risk of VTE in patients with NIHSS score > 5 points (P<0.05).ConclusionsOur results suggest that there may be a potential synergistic interaction between transfusion history and previous stroke history on the risk of VTE. Besides, the percentage of VTE incidence explained by interaction increased with the severity of stroke. Our findings will provide valuable evidence for thromboprophylaxis in Chinese stroke patients.

Synergistic effects of the galanin analog 810-2 with the antiseizure medication levetiracetam in rodent seizure models.

The use of many antiseizure medications (ASMs) is limited due to pharmacoresistance and dose-limiting side effects, suggesting an unmet need for novel therapeutic approaches. The neuropeptide galanin reduces seizures in several preclinical seizure and epilepsy models, but its clinical utility is limited due to rapid metabolism and poor blood-brain barrier penetration. The lead galanin analog 810-2 is systemically bioavailable and reduces seizures when administered alone. Further development of this analog, with the potential for use as an add-on therapy in patients with epilepsy, requires a better understanding of the use of this analog in combination with approved ASMs. We sought to evaluate 810-2 in combination with commonly used ASMs in rodent models of seizures. The mouse 6-Hz seizure assay was used to test efficacy of 810-2 in combination with levetiracetam (LEV), valproic acid (VPA), or lacosamide (LCM) using a 1:1 dose ratio in isobolographic studies. Further characterization was performed for the combination of 810-2 and LEV in the mouse corneal kindling and rat 6-Hz assays. Whereas the combination of 810-2 with VPA and LCM yielded additive interactions, the combination of 810-2 with LEV demonstrated a synergistic interaction in the mouse 6-Hz assay. Supra-additive effects were also observed in the mouse corneal kindling and rat 6-Hz assays for this combination. The combination of 810-2 with LEV suggests the potential for this galanin analog to be further developed as an add-on therapy for patients with epilepsy, particularly when coadministered with LEV.

Joint Effect of Multiple Prothrombotic Genotypes and Mean Platelet Volume on the Risk of Incident Venous Thromboembolism.

A high mean platelet volume (MPV), a marker of increased platelet reactivity, is a risk factor for venous thromboembolism (VTE). Whether established prothrombotic single nucleotide polymorphisms (SNPs) further increase the VTE risk in subjects with high MPV because of biological interaction remains unknown. To investigate the joint effect of high MPV and prothrombotic genotypes, comprising a 5-SNP genetic risk score (GRS), on the risk of VTE in a population-based case-cohort. Incident VTE cases (n = 653) and a subcohort (n = 1,774) were derived from the Tromsø Study (1994-2012). DNA was genotyped for rs8176719 (ABO), rs6025 (F5), rs1799963 (F2), rs2036914 (F11), and rs2066865 (FGG). Hazard ratios (HRs) for VTE with 95% confidence intervals (CIs) were estimated according to predefined MPV-strata (<8.5, 8.5-9.5, ≥9.5 fL) and number of risk alleles for each individual SNP and the GRS (0-1, 2-3, ≥4 risk alleles) in models adjusted for age, sex, body mass index, and platelet count. The combination of high MPV and risk alleles, either as individual SNPs or the GRS, had an additive effect on VTE risk. Compared with subjects with MPV <8.5 fL and 0-1 risk allele, those with high MPV (≥9.5 fL) and ≥4 risk alleles had HRs of 2.80 (95% CI: 1.77-4.43) for overall VTE and 4.60 (95% CI: 2.20-9.60) for unprovoked events, respectively, but there was no supra-additive effect on risk estimates. The combination of high MPV and prothrombotic genotypes had an additive effect on VTE risk, suggesting there is no biological interaction between these risk factors in the pathogenesis of VTE.

Influence of coexposure to long working hours and ergonomic risk factors on musculoskeletal symptoms: an interaction analysis

ObjectivesThis study explores the interaction between ergonomic risk factors and long working hours on musculoskeletal symptoms by additive and multiplicative scales.DesignWe used the data of the fifth Korean Working Condition...

DNA Double-Strand Breaks Induced in Human Cells by 6 Current Pesticides: Intercomparisons and Influence of the ATM Protein.

A mechanistic model from radiobiology has emerged by pointing out that the radiation-induced nucleo-shuttling of the ATM protein (RIANS) initiates the recognition, the repair of DNA double-strand breaks (DSB), and the final response to genotoxic stress. More recently, we provided evidence in this journal that the RIANS model is also relevant for exposure to metal ions. To document the role of the ATM-dependent DSB repair and signaling after pesticide exposure, we applied six current pesticides of domestic and environmental interest (lindane, atrazine, glyphosate, permethrin, pentachlorophenol and thiabendazole) to human skin fibroblast and brain cells. Our findings suggest that each pesticide tested may induce DSB at a rate that depends on the pesticide concentration and the RIANS status of cells. At specific concentration ranges, the nucleo-shuttling of ATM can be delayed, which impairs DSB recognition and repair, and contributes to toxicity. Interestingly, the combination of copper sulfate and thiabendazole or glyphosate was found to have additive or supra-additive effects on DSB recognition and/or repair. A general mechanistic model of the biological response to metal and/or pesticide is proposed to define quantitative endpoints for toxicity.

Characterization of the Discriminative Stimulus Effects of Binary Mixtures of Mu Opioid Receptor Agonists in Rats Discriminating Fentanyl.

Drug overdose deaths involving synthetic opioids, primarily fentanyl, have risen dramatically over the past decade and are currently the driving force of the opioid epidemic in the United States. Fentanyl analogs with greater potency than fentanyl (e.g., carfentanil) pose serious risk to public health. Although fentanyl analogs are primarily encountered by humans as constituents of a mixture of drugs, research has primarily evaluated the effects of these drugs alone. The present study characterized interactions between mu opioid receptor agonists in seven male Sprague-Dawley rats trained to discriminate 10 μg/kg fentanyl from saline while responding under a fixed-ratio 10 schedule of food presentation. Dose-effect curves were determined for each drug alone and in binary mixtures (fentanyl:heroin, fentanyl:carfentanil, and heroin:carfentanil) at fixed-dose ratios of 3:1, 1:1, and 1:3 relative to the ED50 for each drug when given alone. Dose addition analyses were used to determine the nature of the drug-drug interaction for each mixture. Additive interactions were observed for all binary mixtures at each fixed dose ratio, except the 1:3 fentanyl:carfentanil mixture, which exhibited supra-additive effects at the 80% effect level. These results suggest a lack of a significant interaction between the discriminative stimulus effects of these mu opioid receptor agonists at the doses tested in this study. Future studies expanding these findings to the respiratory depressant effects of these drugs are of significant importance to rule out possible interactions directly relevant to opioid overdose that occur at doses much larger than those tested in this study. SIGNIFICANCE STATEMENT: In the United States, drug overdose deaths involving synthetic opioids, primarily fentanyls including superpotent fentanyl analogs (e.g., carfentanil), have increased 12-fold over the past decade. Although previous studies have evaluated the effects of carfentanil alone, fentanyl analogs are encountered by humans as a mixture with other drugs; this study determined the effects of mixtures of carfentanil and other opioids (fentanyl and heroin) to characterize interactions between these drugs that might contribute to their apparent increased lethality in humans.

The effects of cannabidiol, Δ9-tetrahydrocannabinol, and combinations of cannabidiol and Δ9-tetrahydrocannabinol in the open field test and forced swim test

Background . Depression is the most common psychiatric comorbidity in people living with epilepsy, affecting approximately 25–35% of patients. Antidepressants are typically prescribed for depression, but they only provide relief in about two-thirds of patients. Recent research suggests that the cannabinoids might provide a new therapy for depression in both epileptic and non-epileptic patients. Methods . The effects of cannabidiol (CBD), Δ9-tetrahydrocannabinol (THC), and combinations of CBD and THC were tested in a mouse model of depression (the forced swim test, FST) and locomotor activity (the open field test, OFT). Adult, male CD-1 mice were injected intraperitoneally with CBD (0 or 30 mg/kg), THC (0 or 2 mg/kg) or CBD + THC (0 + 0, 30 + 1, 30 + 2 mg/kg). They were then tested for 30 min in the OFT and for 6 min in the FST. Results . As compared to vehicle, CBD, and THC both significantly decreased the time spent immobile and increased the time spent swimming in the FST. THC, however, also significantly increased locomotor activity in the OFT, suggesting a non-specific effect. In combination, CBD and THC lost their effects in both tests and did not differ from vehicle. Conclusions . These results suggest that CBD might be potentially useful for people living with depression. In the present study, however, combinations of CBD and THC had an infra-additive effect rather than the supra-additive effect reported in a previous study. Since CBD and THC in combination produced effects that are less than the sum of the drugs alone (1 + 1 > 2), this may suggest the presence of antagonistic interactions between these two cannabinoids. This research was conducted with the support of EpLink - the Epilepsy Research Program of the Ontario Brain Institute.

Abstract 1182: The NEDD8 inhibitor pevonedistat blocks the repair of topoisomerase I (TOP1)-induced replication damage and synergizes with TOP1 inhibitors

Abstract Genomic DNA is constantly challenged by various genotoxic substances, resulting in an array of DNA lesions including DNA-protein crosslinks (DPCs), one of the most detrimental forms of DNA damage. Topoisomerase I (TOP1) is the molecular target of anti-cancer agents camptothecin derivatives and indenoisoquinolines, which act by trapping TOP1 on genomic DNA. The resulting TOP1-DPCs interfere with DNA replication and transcription and trigger cell death if left unrepaired. In this work, we found that the ubiquitin-like protein NEDD8 plays a pivotal role in the repair of TOP1-DPCs by activating the cullin 4 (CUL4)-RING ubiquitin ligases (CRL4) for K48-linked polyubiquitylation of TOP1-DPCs and their subsequent proteasomal degradation. We identified DCAF13, an understudied family member of DDB1- and CUL4-asscoiated factors, as the receptor of TOP1-DPCs for CRL4. DCAF13 colocalizes with TOP1-DPCs at nascent replication forks and binds the TOP1 core domain with its WD40 domains, linking TOP1 to DDB1-CRL4 for ubiquitylation upon TOP1-induced replication damage. Prompted by these findings, we hypothesized that targeting this NEDD8-activated repair pathway can be developed as a strategy to overcome resistance to TOP1 inhibitors. To test this hypothesis, we performed pharmacological analyses using CellMiner (http://discover.nci.nih.gov/cellminercdb) and found that the activities of TOP1 inhibitors and pevonedistat, a first-in-class NEDD8-activating enzyme inhibitor in clinical trial, are highly correlated across cancer cell lines and with the expression of SLFN11. We also assessed the sensitivity of cultured cancer cells to combination of clinical TOP1 inhibitors and pevonedistat. The combination exhibited synergy in multiple cell lines particularly in human colon cancer cells HCT116 independently of SLFN11. We next investigated the efficacy of combination with TOP1 inhibitor topotecan and pevonedistat in HCT116 xenografts and observed supra-additive effect on tumor growth inhibition. Taken together, our work not only identifies a novel pathway for the repair of TOP1-DPCs but also provides translational evidence to support pevonedistat in combination with TOP1 inhibitors as a rationale therapeutic combination for cancer treatments. Citation Format: Yilun Sun, Andrea Baechler, Valentina Factor, Kanako Okamoto, Yves Pommier. The NEDD8 inhibitor pevonedistat blocks the repair of topoisomerase I (TOP1)-induced replication damage and synergizes with TOP1 inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1182.

Substance Use, Highly Active Antiretroviral Therapy, and Liver Enzymes: Evidence From a Cross-Sectional Study of HIV-Infected Adult Patients Without Comorbidities on HAART in the University of Port Harcourt Teaching Hospital.

This study applied a structural equation modeling (SEM) to evaluate the role of substance use (alcohol, smoking, and trado-medicine use) to changes in the liver enzymes (AST, ALT, and ALP) levels in HIV-infected adult patients on a highly active antiretroviral treatment (HAART) for not <1 year. The study was a cross-sectional, part of a randomized comparative trial (Ref: UPH/CEREMAD/REC/19), involving 129 (46 males and 83 females) HIV-infected adult patients. Liver enzyme levels were determined from analyzed blood samples using the Clinical Chemistry Analyser (VS10) manufactured by Vitro Scient, while the study determined substance use using a reliable (Cronbach alpha = 0.805) rapid-exploratory survey questionnaire. Liver enzyme values were further categorized into: normal or abnormal using normal reference ranges (ALT = 7–55 U/L, AST = 8–48 U/L, and ALP = 40–129 U/L). STATGRAPHICS V16.1.11 (StatPoint Tech., Inc.) and SPSS (IBM® Amos V21.0.0, USA) were used to analyze the data. Among the HIV-HAART patients, 27.9% were alcohol users, 20.9% smokers, and 20.1% trado-medicine users. In addition, ALP (71.3%) abnormality was higher than ALT (34.9%) and AST (28.7%). The result from the SEM provided only a partial support for our hypotheses of direct substance use effects on the liver enzyme levels and abnormalities; with a direct association of alcohol with an elevated AST (b = 0.170, p = 0.05) and smoking with a higher AST (b = 0.484, p < 0.01) and ALT (b = 0.423, p < 0.01) values. Trado-medicine use was not directly associated with enzyme elevation and abnormality. In conclusion, ALP abnormality was the most common, and there is a close association between an elevated ALT and AST, with or without an elevated ALP. The study found that HIV-HAART patients who drink or smoke will have at least one or more abnormal transaminases. The possible explanation to the increased risk among HIV-HAART patients could be associated with the metabolic pressures and supra-additive effects on the livers.