Nefopam and ketoprofen synergy in rodent models of antinociception

A meta analysis of efficacy and safety of nefopam for laparoscopic cholecystectomy pain management

Background

Nefopam is a safe analgesic with mild side effects including drowsiness, nausea, vomiting, and sweating. Nevertheless, research is scarce on the impact of nefopam in managing postoperative pain following laparoscopic cholecystectomy (LC), and the advantageous effects of nefopam remain unclear. In this research, the effectiveness of nefopam was compared to placebo for the treatment of postoperative pain following LC.

Methods

A literature search for randomized controlled trials (RCTs) was performed through June 2024 using online databases including Cochrane Library, PubMed/Medline, and Web of Science. The primary outcome assessed was the quality of postoperative patient pain, and the secondary outcome was side effects that occurred due to the use of nefopam. The Cochrane Risk of Bias (RoB) 2 tool was used to assess the RoB. The meta-analysis was conducted using Review Manager software version 5.4. The risk ratio (RR), mean difference (MD), and standardized mean difference (SMD) were calculated at 95% confidence intervals (CIs).

Results

Five RCTs comprising 254 participants were analyzed. The analysis revealed that compared to placebo, nefopam had no statistically significant effect on the reduction of postoperative pain severity at 30 min (SMD = -0.30, 95% CI: -0.61 to 0.01; P = 0.06) and 60 min (SMD = -0.31, 95% CI: -0.78 to 0.16; P = 0.20). Nefopam reduced the number of opioids taken, as shown in the meta-analysis (SMD = -0.94, 95 CI: -1.35 to -0.53; P < 00001), with minor heterogeneity (P = 0.24, I2 = 30%). This meta-analysis showed that nefopam lengthened the time to first rescue analgesia (MD = 23.003). and markedly reduced the number patients requiring analgesics compared to baseline (RR = 0.34, 95% CI: 0.22 to 0.54; P < 0.00001).

Conclusion

Nefopam did not cause any difference in total postoperative pain but was effective in reducing overall opioid consumption and the need for supplementary analgesics. It did not increase postoperative nausea and vomiting.

A novel dihydroacridine derivative targets epidermal growth factor receptor-expressing cancer cells in vitro and in vivo

Small molecules are considered a source of novel medicines targeting carcinogenic intracellular pathways including epidermal growth factor receptor (EGFR) signaling. The main goal of the study is to assess whether LHT-17-19 could be considered an effective target molecule against EGFR-expressing tumor cells in silico, in vitro, and in vivo. This was an in vivo, ex vivo, and in vivo experimental study. LHT-17-19 affinity to EGFR's kinase domain was assessed by the ligand's molecular docking. EGFR-expressing Hs746T human gastric cancer cell culture and patient-derived organoid (PDO) model of EGFR-positive breast cancer (BC) were used for in vitro assessment of the molecule anticancer property. IC50 and GI50 indexes were estimated using MTT- and MTS-based tests, respectively. Anticancer activity of LHT-17-19 against EGFR-expressing mutant lung carcinoma was studied on patient-derived xenograft (PDX) model established in 10 humanized BALB/c male mice. Continuous variables were presented as a mean ± standard deviation. Intergroup differences were assessed by two-way t-test. Kaplan-Meier's curves were used for survival analysis. High affinity of LHT-17-19 for the EGFR kinase domain with dG score -7.9 kcal/mol, EDoc-5.45 kcal/mol, and Ki 101.24 uM was due to intermolecular π-σ bonds formation and the ligand intramolecular transformation. LHT-17-19 induced anti-EGFR-expressing gastric cancer cells cytotoxicity with IC50 0.32 µM (95% confidence interval [CI] 0.11-0.54 µM). The derivative inhibited growth of EGFR-expressing BC PDO with GI50 16.25 µM (95% CI 4.44-28.04 µM). 2 mg/kg LHT-17-19 intravenously daily during 7 days inhibited PDX tumor growth and metastatic activity, prolonged animals' survival, and eliminated EGFR-mutant lung cancer cells from residual tumor's node. LHT-17-19 may be considered a molecular platform for further search of promising molecules, EGFR-expressing cancer cell inhibitors.

Anti-inflammatory effects of hunger are transmitted to the periphery via projection-specific AgRP circuits

Caloric restriction has anti-inflammatory effects. However, the coordinated physiological actions that lead to reduced inflammation in a state of caloric deficit (hunger) are largely unknown. Using a mouse model of injury-induced peripheral inflammation, we find that food deprivation reduces edema, temperature, and cytokine responses that occur after injury. The magnitude of the anti-inflammatory effect that occurs during hunger is more robust than that of non-steroidal anti-inflammatory drugs. The effects of hunger are recapitulated centrally by activity in nutrient-sensing hypothalamic agouti-related protein (AgRP)-expressing neurons. We find that AgRP neurons projecting to the paraventricular nucleus of the hypothalamus rapidly and robustly reduce inflammation and mediate the majority of hunger's anti-inflammatory effects. Intact vagal efferent signaling is required for the anti-inflammatory action of hunger, revealing a brain-to-periphery pathway for this reduction in inflammation. Taken together, these data begin to unravel a potent anti-inflammatory pathway engaged by hypothalamic AgRP neurons to reduce inflammation.

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.

Pharmacokinetic Criteria of Ketoprofen and its Cyclooxygenase-2 Inhibition in Mice: Influence of Xylazine Administration

The objective of this study was to examine the effect of ketoprofen with or without combination with xylazine on the level of cyclooxygenase-2 in mice. The intraperitoneal (i.p.) dose of ketoprofen and xylazine that caused an analgesic response in half of the mouse population was 1.26 mg/kg and 6.63 mg/kg, respectively. Serum cyclooxygenase-2 concentration (activity) in the control mice was 16.94 ng/ml. The ketoprofen-treated group (2.52 mg/kg, i.p.) decreased the cyclooxygenase-2 concentration by 58% (7.16 ng/ml). The combined ketoprofen and xylazine treatment (13.26 mg/kg, i.p.) decreased the cyclooxygenase-2 by 94% (0.98 ng/ml). The ketoprofen plasma concentration in the combined treatment group was significantly higher compared to the ketoprofen treatment group. Ketoprofen plasma concentrations measured at 0.25, 0.5, 1, 2, 4, and 24 hours were 19.07, 18.94, 14.66, 6.53, 5.44, and 5.54 µg/ml, respectively. Plasma concentrations of ketoprofen and xylazine were raised to 28.74, 29.74, 15.32, 13.04, 14.64, and 11.95 µg/ml or by 51%, 56%, 5%, 100%, 169%, and 116%, respectively. Ketoprofen pharmacokinetic variables were increased (AUC0-∞ (515%), AUMC0-∞ (2389%), MRT (305%), t1/2β (375%), Tmax (100%), and Cmax (55%)), while other values were decreased (Kel (79%), Vss (25%), and Cl (88%)). Our findings suggested a synergistic interaction between ketoprofen and xylazine on the level of cyclooxygenase-2 (pharmacodynamic interaction) which was exerted by modification of the ketoprofen pharmacokinetic properties in mice.

Prospecting for candidate molecules from Conus virgo toxins to develop new biopharmaceuticals

Background

A combination of pharmacological and biomedical assays was applied in this study to examine the bioactivity of Conus virgo crude venom in order to determine the potential pharmacological benefit of this venom, and its in vivo mechanism of action.

Methods

Two doses (1/5 and 1/10 of LC₅₀, 9.14 and 4.57 mg/kg) of the venom were used in pharmacological assays (central and peripheral analgesic, anti-inflammatory and antipyretic), while 1/2 of LC₅₀ (22.85 mg/kg) was used in cytotoxic assays on experimental animals at different time intervals, and then compared with control and reference drug groups.

Results

The tail immersion time was significantly increased in venom-treated mice compared with the control group. Also, a significant reduction in writhing movement was recorded after injection of both venom doses compared with the control group. In addition, only the high venom concentration has a mild anti-inflammatory effect at the late inflammation stage. The induced pyrexia was also decreased significantly after treatment with both venom doses. On the other hand, significant increases were observed in lipid peroxidation (after 4 hours) and reduced glutathione contents and glutathione peroxidase activity, while contents of lipid peroxidation and nitric oxide (after 24 hours) and catalase activity were depleted significantly after venom administration.

Conclusion

These results indicated that the crude venom of Conus virgo probably contain bioactive components that have pharmacological activities with low cytotoxic effects. Therefore, it may comprise a potential lead compound for the development of drugs that would control pain and pyrexia.

Expression of p53 Protein Associates with Anti-PD-L1 Treatment Response on Human-Derived Xenograft Model of GATA3/CR5/6-Negative Recurrent Nonmuscular Invasive Bladder Urothelial Carcinoma

BACKGROUND

The possible involvement of p53 signaling, FGFR3 expression, and FGFR3 mutation rates in the prediction of the NMIBC anti-PD-L1 treatment response needs to be clarified. The main aim of our study was to explore predictive value of p53 expression, FGFR3 expression, and its gene mutation status for the therapeutic success of anti-PD-L1 treatment in the patient-derived murine model of recurrent high-PD-L1(+) GATA3(-)/CR5/6(-) high-grade and low-grade NMIBC.

METHODS

twenty lines of patient-derived xenografts (PDXs) of relapsed high-PD-L1(+) double-negative NMIBC were developed, of which 10 lines represented high-grade tumors and the other ones-low-grade bladder cancer. Acceptors of each grade-related branch received specific anti-PD-L1 antibodies. Animals' survival, tumor-doubling time, and remote metastasis were followed during the post-interventional period. PD-L1, GATA3, CR5/6, and p53 protein expressions in engrafted tumors were assessed by immunohistochemistry. The FGFR3 expression and FGFR3 mutations in codons 248 and 249 were detected by real-time polymerase chain reaction.

RESULTS

The expression of p53 protein is an independent factor affecting the animals' survival time [HR = 0.036, p = 0.031] of anti-PD-L1-treated mice with low-grade high-PD-L1(+) double-negative NMIBC PDX. The FGFR3 expression and FGFR3 mutation rate have no impact on the anti-PD-L1 treatment response in the interventional groups.

CONCLUSIONS

p53 expression may be considered as a prognostic factor for the anti-PD-L1 treatment efficacy of low-grade high-PD-L1-positive GATA3(-)/CR5/6(-)-relapsed noninvasive bladder cancer.

Cerium-Containing N-Acetyl-6-Aminohexanoic Acid Formulation Accelerates Wound Reparation in Diabetic Animals

Background: The main goal of our study was to explore the wound-healing property of a novel cerium-containing N-acethyl-6-aminohexanoate acid compound and determine key molecular targets of the compound mode of action in diabetic animals. Methods: Cerium N-acetyl-6-aminohexanoate (laboratory name LHT-8-17) as a 10 mg/mL aquatic spray was used as wound experimental topical therapy. LHT-8-17 toxicity was assessed in human skin epidermal cell culture using (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. A linear wound was reproduced in 18 outbred white rats with streptozotocin-induced (60 mg/kg i.p.) diabetes; planar cutaneous defect was modelled in 60 C57Bl₆ mice with streptozotocin-induced (200 mg/kg i.p.) diabetes and 90 diabetic db/db mice. Firmness of the forming scar was assessed mechanically. Skin defect covering was histologically evaluated on days 5, 10, 15, and 20. Tissue TNF-α, IL-1β and IL-10 levels were determined by quantitative ELISA. Oxidative stress activity was detected by Fe-induced chemiluminescence. Ki-67 expression and CD34 cell positivity were assessed using immunohistochemistry. FGFR3 gene expression was detected by real-time PCR. LHT-8-17 anti-microbial potency was assessed in wound tissues contaminated by MRSA. Results: LHT-8-17 4 mg twice daily accelerated linear and planar wound healing in animals with type 1 and type 2 diabetes. The formulated topical application depressed tissue TNF-α, IL-1β, and oxidative reaction activity along with sustaining both the IL-10 concentration and antioxidant capacity. LHT-8-17 induced Ki-67 positivity of fibroblasts and pro-keratinocytes, upregulated FGFR3 gene expression, and increased tissue vascularization. The formulation possessed anti-microbial properties. Conclusions: The obtained results allow us to consider the formulation as a promising pharmacological agent for diabetic wound topical treatment.

Synergism between oral paracetamol and nefopam in a murine model of postoperative pain

BACKGROUND

The use of paracetamol or nefopam for postoperative pain control is limited by the need of high doses associated with unwanted effects. Previous works suggest positive interactions between both compounds that may be exploited to obtain potentiation of antinociception.

METHODS

Mechanical and heat antinociception induced by oral doses of paracetamol, nefopam or their combination was studied by isobolographic analysis in a murine model of postsurgical pain. The effective doses that produced 50% antinociception (ED₅₀ ) were calculated from the log dose-response curves for each compound. Subsequently, the effects of ED_8.7 s, ED_12.5 s, ED_17.5 s and ED₃₅ s of nefopam and paracetamol combined were assessed.

RESULTS

Oral paracetamol induced dose-dependent relief of postoperative sensitivity and showed higher efficacy reducing mechanical hypersensitivity (ED₅₀ 177.3 ± 15.4 mg/kg) than heat hyperalgesia (ED₅₀ 278.6 ± 43 mg/kg). Oral nefopam induced dose-dependent antinociception with similar efficacy for mechanical and heat hypersensitivity (ED₅₀ s 5.42 ± 0.81 vs. 5.83 ± 0.72). Combinations of increasing isoeffective doses revealed that combined ED_17.5 s (85.76 mg/kg paracetamol and 1.9 mg/kg nefopam) and ED₃₅ s (132.67 mg/kg and 3.73 mg/kg) showed synergistic effects leading to 75% and 90% mechanical antinociception, respectively. These mixtures were defined by interaction indexes of 0.43 and 0.41 and ratios 45:1 and 35:1 paracetamol:nefopam, respectively. The same combinations showed additive effects for the inhibition of incisional thermal hyperalgesia.

CONCLUSIONS AND LIMITATIONS

This work describes a synergistic antinociceptive interaction between low doses of nefopam and paracetamol for the treatment of postoperative hypersensitivity to peripheral stimuli. The promising results obtained on reflexive nociceptive responses of young male mice subjected to plantar surgery highlight the interest of further research evaluating the effects of this mixture on the affective-motivational component of pain and in females and additional age groups. Confirmation of pain-relieving efficacy and safety of this oral combination clinically available in European and Asian countries could provide a useful tool for postsurgical pain management.

SIGNIFICANCE

Early postoperative pain is currently undertreated and has been recognized as a relevant source of chronic postsurgical pain. Oral efficient treatments could facilitate fast-track surgeries and patient recovery at home. Here, we identify in a mouse model of postoperative pain a potent synergistic oral combination consisting of low paracetamol and nefopam doses that provides relief of postsurgical hypersensitivity to mechanical and thermal stimuli. Oral multimodal paracetamol-nefopam mixtures represent a potential clinically available pharmacological strategy for the relief of incisional sensitivity and the promotion of patient recovery.

Clinical Management of Pain in Rodents

The use of effective regimens for mitigating pain remain underutilized in research rodents despite the general acceptance of both the ethical imperative and regulatory requirements intended to maximize animal welfare. Factors contributing to this gap between the need for and the actual use of analgesia include lack of sufficient evidence-based data on effective regimens, under-dosing due to labor required to dose analgesics at appropriate intervals, concerns that the use of analgesics may impact study outcomes, and beliefs that rodents recover quickly from invasive procedures and as such do not need analgesics. Fundamentally, any discussion of clinical management of pain in rodents must recognize that nociceptive pathways and pain signaling mechanisms are highly conserved across mammalian species, and that central processing of pain is largely equivalent in rodents and other larger research species such as dogs, cats, or primates. Other obstacles to effective pain management in rodents have been the lack of objective, science-driven data on pain assessment, and the availability of appropriate pharmacological tools for pain mitigation. To address this deficit, we have reviewed and summarized the available publications on pain management in rats, mice and guinea pigs. Different drug classes and specific pharmacokinetic profiles, recommended dosages, and routes of administration are discussed, and updated recommendations are provided. Nonpharmacologic tools for increasing the comfort and wellbeing of research animals are also discussed. The potential adverse effects of analgesics are also reviewed. While gaps still exist in our understanding of clinical pain management in rodents, effective pharmacologic and nonpharmacologic strategies are available that can and should be used to provide analgesia while minimizing adverse effects. The key to effective clinical management of pain is thoughtful planning that incorporates study needs and veterinary guidance, knowledge of the pharmacokinetics and mechanisms of action of drugs being considered, careful attention to individual differences, and establishing an institutional culture that commits to pain management for all species as a central component of animal welfare.

Inter-rater and inter-device reliability of mechanical thresholds measurement with the Electronic von Frey Anaesthesiometer and the SMALGO in healthy cats

OBJECTIVES

The aim of this study was to compare the Electronic von Frey Anaesthesiometer (EVF) and the Small Animal ALGOmeter (SMALGO), used to measure sensory thresholds in 13 healthy cats at both the stifle and the lumbosacral joint, in terms of inter-rater and inter-device reliability.

METHODS

Two independent observers carried out the sets of measurements in a randomised order, with a 45 min interval between them, in each cat. The inter-rater and inter-device reliability were evaluated by calculating the inter-rater correlation coefficient (ICC) for each pair of measurements. The Bland-Altman method was used as an additional tool to assess the level of agreement between the two algometers.

RESULTS

The mean ± SD sensory thresholds measured with the EVF were 311 ± 116 g and 378 ± 178 g for the stifle and for the lumbosacral junction, respectively, whereas those measured with the SMALGO were 391 ±172 g and 476 ± 172 g. The inter-rater reliability was fair (ICC >0.4) for each pair of measurements except those taken at the level of the stifle with the SMALGO, for which the level of agreement between observers A and B was poor (ICC = 0.01). The inter-device reliability was good (ICC = 0.73; P = 0.001). The repetition of the measurements affected reliability, as the thresholds obtained after the 45 min break were consistently lower than those measured during the first part of the trial (P = 0.02).

CONCLUSIONS AND RELEVANCE

The EVF and the SMALGO may be used interchangeably in cats, especially when the area to be tested is the lumbosacral joint. However, when the thresholds are measured at the stifle, the inter-observer reliability is better with the EVF than with the SMALGO. The reliability decreases when the measurements are repeated within a short time interval, suggesting a limited clinical applicability of quantitative sensory testing with both algometers in cats.

3,3'-Diindolylmethane nanoencapsulation improves its antinociceptive action: Physicochemical and behavioral studies

This study aimed to characterize the physicochemical properties of 3,3'-diindolylmethane (DIM)-loaded nanocapsules (NCs) as well as the antinociceptive effect using distinct animal models (hot plate test, formalin-induced nociception and complete Freud's adjuvant induced paw inflammation). The DIM-loaded NCs (composed by primula oil and ethylcellulose) were characterized using differential scanning calorimetry, thermogravimetric analysis, Fourier-transformed infrared spectroscopy, X-ray diffractometry and scanning electron microscopy. The physicochemical characterization demonstrated that DIM could be molecularly dispersed into the NCs, whose size was nanometric with a spherical shape. An improvement in DIM thermal stability was achieved by its encapsulation and there were no interactions among the formula components. For the nociceptive evaluation, male adult Swiss mice were pretreated with the NCs or free DIM by the intragastric route at the dose of 10 mg/Kg (time-response curve), 5 or 2.5 mg/Kg (dose-response curve). The behavioral tests were performed over an experimental period of 0.5-8 h. Both free and nanoencapsulated DIM reduced the mechanical hypernociception induced by CFA, mitigated nociceptive behavior of formalin-induced neurogenic and inflammatory pain and increased paw withdrawal latency assessed by the hot-plate test. Importantly, the DIM nanoencapsulation promoted a rapid initiation and prolonged the bioactive antinociceptive action (up to 8 h) as well as reduced the effective dose in comparison to its free form. In summary, this study reported that the NCs had adequate nanometric size, increased DIM stability and its antinociceptive action in different animal models, suggesting that the formulation may be a possible therapeutic alternative to the management of pain and inflammatory-related pathologies.

Programmed death-ligand 1 signaling pathway involves in bladder cancer growth and progression

CONTEXT:

Exploration of the biological property of programmed death-ligand 1 (PD-L1) signaling that may impact bladder tumor growth in humanized animals and cell culture.

AIMS:

The aim of this study is to evaluate how PD-L1 signaling involves bladder cancer growth and progression.

SETTINGS AND DESIGN:

This study design involves experimental in vivo and in vivo study.

SUBJECTS AND METHODS:

A role of PD-L1 signaling pathway inhibition for bladder cancer growth was assessed in humanized immunodeficient animals carried main molecular subtypes of bladder carcinoma patient-derived xenografts and provided with selective anti-PD-L1 treatment; bladder cancer cells invasiveness was evaluated in mixed RT112/84 cells + CD4⁺ cells culture incubated with PD-L1 blocker durvalumab. We used two-tailed Student's t-test to explore differences between main and control subgroups. Significance of intergroup comparison was measured with one-way ANOVA followed by the Tukey's or Newman–Keul's criterion. Survival curves were analyzed with Gehan's criterion with the Yate's correction. Differences were considered statistically significant at P < 0.05.

RESULTS:

Anti-PD-L1 intervention increased survival of the animals carried both primary and relapsed luminal noninvasive, muscular invasive, and relapsed luminal bladder cancer xenografts. There was significant retardation of tumor volume duplication time in aforementioned subgroups correlated with PD-L1 expression. Durvalumab treatment in concentration-dependent manner inhibited tumor cells invasiveness of mixed RT112 + CD4⁺ culture cells with its maximum at the highest studied concentration (10 μM).

CONCLUSIONS:

Obtained data constituted the pivotal role of programmed cell death-1/PD-L1 signaling pathway in bladder cancer development and progression. The results will have major implications for further clinical investigations.

Patient-Derived Non-Muscular Invasive Bladder Cancer Xenografts of Main Molecular Subtypes of the Tumor for Anti-Pd-l1 Treatment Assessment

Background: Establishment of heterotopic patient-derived xenografts of primary and relapsed non-muscular invasive bladder cancer (NMIBC) to explore the biological property of PD-L1 signaling that may impact bladder tumor growth in humanized animals. Methods: Tumor cells of luminal, basal, and p53 subtypes of primary and relapsed NMIBC were engrafted to irradiated (3.5 Gy) NOG/SCID female mice along with intraperitoneal transplantation of human lymphocytes (5 × 10⁷ cells/mouse); a role of PD-L1 signaling pathway inhibition for bladder cancer growth was assessed in humanized animals that carried PD-L1-expressing main molecular subtypes of bladder carcinoma patient-derived xenografts (PDX) and provided with selective anti-PD-L1 treatment. We used two-tailed Student’s t test to explore differences between main and control subgroups. Significance of intergroup comparison was measured with one-way ANOVA followed by the Tukey’s or Newman–Keul’s criterion. Survival curves were analyzed with the Gehan’s criterion with the Yate’s correction. The Spearman’s correlation was used to assess the link between CD8⁺ expression and sPD-L1 serum level. Differences were considered statistically significant at p < 0.05. Results: Heterotopic primary and relapsed luminal, basal, and p53 subtypes of NMIBC PDXs were established. More than 25% of counted tumor cells of all PDX specimens expressed PD-L1, so the tumors were ranged as PD-L1 positive. Anti-PD-L1 intervention increased survival of the animals that carried both primary and relapsed luminal noninvasive, muscular invasive, and relapsed luminal bladder cancer xenografts. There was significant retardation of tumor volume duplication time in aforementioned subgroups correlated with PD-L1 expression. Bad response of p53 mutant subtypes of NMIBC on specific anti-PD-L1 treatment may be associated with low CD8⁺ cells representation into the tumors tissue. Conclusions: Established PD-L1-positive NMIBC PDXs differently replied on anti-PD-L1 treatment due to both NMIBC molecular subtype and tumor T-suppressors population. The results may have major implications for further clinical investigations.

Contribution of diacylglycerol lipase β to pain after surgery

Background

Metabolism of the endocannabinoid 2-arachidonoylglycerol (2-AG) yields arachidonic acid (AA), the precursor to proalgesic eicosanoids including prostaglandin E2 (PGE₂). Diacylglycerol lipase β (DAGLβ) is an enzyme that synthesizes 2-AG and its inhibition reduces eicosanoid levels and produces antinociceptive effects in models of inflammatory pain. Here we test whether inhibition of DAGLβ produces antinociceptive effects in a model of postoperative pain.

Methods

Rats were administered the selective DAGLβ inhibitor KT109 or vehicle and underwent plantar incision. Postsurgical pain/disability was examined using evoked (mechanical hyperalgesia), functional (incapacitance/weight bearing), and functional/spontaneous (locomotion) modalities.

Results

Activity-based protein profiling confirmed that KT109 inhibited DAGLβ in the lumbar spinal cord (LSC) and brain, confirming that it is a systemically active DAGLβ inhibitor. Treatment with KT109 reduced basal 2-AG, AA, and PGE₂ levels in the liver but not the brain, indicating that DAGLβ activity does not significantly contribute to basal PGE₂ production within the central nervous system. Plantar incision elevated the levels of 2-AG and PGE₂ in the LSC. Although KT109 did not alter postsurgical 2-AG levels in the LSC, it slightly reduced PGE₂ levels. In contrast, the clinically efficacious cyclooxygenase inhibitor ketoprofen completely suppressed PGE₂ levels in the LSC. Similarly, KT109 had no significant effect upon postsurgical 2-AG, AA, or PGE₂ levels at the incision site, while ketoprofen abolished PGE₂ production at this location. KT109 and ketoprofen reversed the weight bearing imbalance induced by plantar incision, yet neither KT109 nor ketoprofen had any significant effect on mechanical hyperalgesia. Treatment with ketoprofen partially but significantly rescued the locomotor deficit induced by incision while KT109 was without effect.

Conclusion

DAGLβ is not the principal enzyme that controls 2-AG derived AA and PGE₂ production after surgery, and inhibitors targeting this enzyme are unlikely to be efficacious analgesics superior to those already approved to treat acute postoperative pain.

Pharmacological modulation of neuropathic pain-related depression of behavior: effects of morphine, ketoprofen, bupropion and [INCREMENT]9-tetrahydrocannabinol on formalin-induced depression of intracranial self-stimulation in rats

Neuropathic pain is often associated with behavioral depression. Intraplantar formalin produces sustained, neuropathy-associated depression of intracranial self-stimulation (ICSS) in rats. This study evaluated pharmacological modulation of formalin-induced ICSS depression. Rats with intracranial electrodes targeting the medial forebrain bundle responded for electrical brain stimulation in an ICSS procedure. Bilateral intraplantar formalin administration depressed ICSS for 14 days. Morphine (0.32-3.2 mg/kg), ketoprofen (0.1-10 mg/kg), bupropion (3.2-32 mg/kg), and [INCREMENT]9-tetrahydrocannabinol (THC; 0.32-3.2 mg/kg) were evaluated for their effectiveness to reverse formalin-induced depression of ICSS. Drug effects on formalin-induced mechanical allodynia were evaluated for comparison. Morphine and bupropion reversed both formalin-induced ICSS depression and mechanical allodynia, and effects on ICSS were sustained during repeated treatment. Ketoprofen failed to reverse either formalin effect. THC blocked mechanical allodynia, but decreased ICSS in control rats and exacerbated formalin-induced depression of ICSS. The failure of ketoprofen to alter formalin effects suggests that formalin effects result from neuropathy rather than inflammation. The effectiveness of morphine and bupropion to reverse formalin effects agrees with other evidence that these drugs block pain-depressed behavior in rats and relieve neuropathic pain in humans. The effects of THC suggest general behavioral suppression and do not support the use of THC to treat neuropathic pain.

The Antiallodynic Effects of Nefopam Are Mediated by the Adenosine Triphosphate-Sensitive Potassium Channel in a Neuropathic Pain Model

BACKGROUND

Nefopam hydrochloride is a centrally acting compound that induces antinociceptive and antihyperalgesic properties in neuropathic pain models. Previous reports have shown that activation of adenosine triphosphate (ATP)-sensitive and calcium-activated potassium (KATP and KCa2+) channels has antiallodynic effects in neuropathic pain. In the present study, we evaluated the relationship between potassium channels and nefopam to determine whether the antiallodynic effects of nefopam are mediated by potassium channels in a neuropathic pain model.

METHODS

Mechanical allodynia was induced by spinal nerve ligation (SNL) in rats, and the paw withdrawal threshold (PWT) was evaluated by the use of von Frey filaments. Nefopam was administered intraperitoneally before or after SNL. We assessed the relationship between nefopam and intrathecal injection of the KCa2+ channel antagonists apamin and charybdotoxin, and the KATP channel blocker glibenclamide to assess their abilities to reverse the antiallodynic effects of nefopam. In addition, we evaluated whether the KATP channel opener pinacidil had antiallodynic effects and promoted the antiallodynic effects of nefopam.

RESULTS

Administration of nefopam before and after SNL induced significant antiallodynic effects (P < .01, respectively), which were significantly reduced by glibenclamide (P < .01). Pinacidil improved the antiallodynic effects of nefopam (P < .01); however, apamin and charybdotoxin had little effects on the antiallodynic properties of nefopam.

CONCLUSIONS

The antiallodynic effects of nefopam are increased by a KATP channel agonist and reversed by a KATP channel antagonist. These data suggest that the KATP channel is involved in the antiallodynic effects of nefopam in a neuropathic pain model.

Patient's satisfaction after outpatient forefoot surgery: Study of 619 cases

INTRODUCTION

The number of outpatient surgical procedures performed in France on the forefoot has grown rapidly in recent years.

OBJECTIVES

The goal of this study was to evaluate experience and satisfaction of patients undergoing outpatient foot surgery using a telephone questionnaire developed for this purpose.

MATERIAL AND METHODS

In 2012 and 2013, every patient who was admitted to the day surgery unit at our hospital for an open procedure on their forefoot was called the morning after the procedure. A nurse went through the 14-item questionnaire with the patient. The same perioperative protocol, written instructions and treatment were used for all patients.

RESULTS

Six hundred nineteen patients were included. The questionnaire response rate was 89% (n=540). Isolated hallux valgus surgery was performed on 319 patients (61%); 107 patients (20%) underwent hallux valgus surgery with lateral metatarsal osteotomy; 57 patients (10.5%) underwent first metatarsophalangeal fusion and 47 patients (8.5%) underwent a procedure on the lateral rays only. In the postoperative phase, 65% reported having satisfactory sleep quality, 32% had experienced nausea, 16% had experienced vomiting and 17% had experienced bleeding. Eighty percent of patients experienced pain (VAS ≥ 1); 80% of these patients had their pain relieved by the prescribed treatment and 4% had not taken it. Nearly all the patients (99%) were satisfied with the outpatient care; the overall satisfaction score was 9.4 out of 10. There was a significant relationship between the type of procedure and vomiting, pain, bleeding and fever.

DISCUSSION

Outpatient care is becoming more common in response to economic challenges. The development of outpatient foot surgery appears to have satisfied the vast majority of operated patients. However, adjustments should be made to improve their tolerance to the pain management protocol. Although the logistics of performing follow-up call can be complicated, the patients appreciate receiving this call the next day. The call also seems to reassure both the patients and care providers.

Synthesis of pyrazoles containing benzofuran and trifluoromethyl moieties as possible anti-inflammatory and analgesic agents

Searching for new anti-inflammatory and analgesic agents, we have prepared a series of novel pyrazoles containing benzofuran and trifluoromethyl moieties. The pyrazole derivatives have been synthesized via two routes starting from 5-(3-(trifluoromethyl)phenyl azo) salicylaldehyde. The first route involved the synthesis of 2-acetylbenzofuran and then treatment with aldehydes to afford the corresponding chalcones. The cyclization of the latter chalcones with hydrazine hydrate led to the formation of new pyrazoline derivatives. The second route involved the synthesis of benzofuran-2-carbohydrazide and then treatment with formylpyrazoles, chalcones and ketene dithioacetal derivatives to afford the corresponding pyrazole derivatives. Some of the synthesized compounds exhibited anti-inflammatory and analgesic activities.

Spinal noradrenergic modulation and the role of the alpha-2 receptor in the antinociceptive effect of intrathecal nefopam in the formalin test

BACKGROUND

Nefopam has shown an analgesic effect on acute pain including postoperative pain. The reuptake of monoamines including serotonin and noradrenaline has been proposed as the mechanism of the analgesic action of nefopam, but it remains unclear. Although alpha-adrenergic agents are being widely used in the perioperative period, the role of noradrenergic modulation in the analgesic effect of nefopam has not been fully addressed.

METHODS

Changes in the antinociceptive effect of intrathecal (i.t.) nefopam against formalin-elicited flinching responses were explored in Sprague-Dawley rats pretreated with i.t. 6-hydroxydopamine (6-OHDA), which depletes spinal noradrenaline. In addition, antagonism to the effect of nefopam by prazosin and yohimbine was evaluated to further elucidate the antinociceptive mechanism of i.t. nefopam.

RESULTS

Pretreatment with i.t. 6-OHDA alone did not alter the flinching responses in either phase of the formalin test, while it attenuated the antinociceptive effect of i.t. nefopam significantly during phase 1, but not phase 2. The antagonist of the alpha-2 receptor, but not the alpha-1 receptor, reduced partially, but significantly, the antinociceptive effect of i.t. nefopam during phase 1, but not during phase 2.

CONCLUSIONS

This study demonstrates that spinal noradrenergic modulation plays an important role in the antinociceptive effect of i.t. nefopam against formalin-elicited acute initial pain, but not facilitated pain, and this action involves the spinal alpha-2 but not the alpha-1 receptor.

Analgesic activity of some 1,2,4-triazole heterocycles clubbed with pyrazole, tetrazole, isoxazole and pyrimidine

PURPOSE

In the present study in vivo analgesic activity of some previously synthesized 1,2,4-triazole derivatives containing pyrazole, tetrazole, isoxazole and pyrimidine ring have been evaluated.

METHODS

Acetic acid induced writhing method and Hot plate method has been described to study analgesic activity of some 1,2,4-triazole derivatives containing pyrazole, tetrazole, isoxazole and pyrimidine as a pharmacological active lead.

RESULTS

Thirty six different derivatives containing 1,2,4-triazole ring were subjected to study their in vivo analgesic activity. Chloro, nitro and methoxy, hydroxy and bromo substituted derivatives showed excellent analgesic activity and dimethylamino, furan and phenyl substituted derivatives showed moderate analgesic activity in both of the methods. Compounds IIIa, IIId, IIIf, IIIi, IIIj, IVa, IVb, IVd, IVf, IVh, IVj IV3a and IIj were found to be superior analgesic agents after screening by Acetic acid induced writhing method. Compounds IIIb, IIId, IIIf, IIIh, IIIj, IVa, IVb, IVd, IVf, IVh, IVi, IV3c, IV3e and IIj were showed analgesic potential after screening of Hot plate method.

CONCLUSION

All tested compounds containing 1,2,4-triazole were found to be promising analgesic agents, for this activity pyrazole, tetrazole, isoxazole and pyrimidine leads might be supported.

Antinociceptive effect of intrathecal nefopam and interaction with morphine in formalin-induced pain of rats

Background

Nefopam, a non-opiate analgesic, has been regarded as a substance that reduces the requirement for morphine, but conflicting results have also been reported. The inhibition of monoamine reuptake is a mechanism of action for the analgesia of nefopam. The spinal cord is an important site for the action of monoamines however, the antinociceptive effect of intrathecal nefopam was not clear. This study was performed to examine the antinociceptive effect of intrathecal (i.t.) nefopam and the pattern of pharmacologic interaction with i.t. morphine in the formalin test.

Methods

Male Sprague-Dawley rats were implanted with an i.t. catheter, and were randomly treated with a vehicle, nefopam, or morphine. Formalin was injected into the hind-paw 10 min. after an i.t. injection of the above experiment drugs. After obtaining antinociceptive ED₅₀ of nefopam and morphine, the mixture of nefopam and morphine was tested for the antinociceptive effect in the formalin test at a dose of 1/8, 1/4, 1/2 of ED₅₀, or ED₅₀ of each drug followed by an isobolographic analysis.

Results

Intrathecal nefopam significantly reduced the flinching responses in both phases of the formalin test in a dose-dependent manner. Its effect, however, peaked at a dose of 30 µg in phase 1 (39.8% of control) and 10 µg during phase 2 (37.6% of control). The isobolograhic analysis indicated an additive interaction of nefopam and morphine during phase 2, and a synergy effect in antinociception during phase 1.

Conclusions

This study demonstrated that i.t. nefopam produces an antinociceptive effect in formalin induced pain behavior during both phases of the formalin test, while interacting differently with i.t. morphine, synergistically during phase 1, and additively during phase 2.

Analgesic and Toxicity Studies of Aminoacetylenic Isoindoline-1,3-dione Derivatives

We have developed a series of aminoacetylenic isoindoline-1,3-dione compounds and showed their anti-inflammatory activities by reducing carrageenan-induced rat paw edema and modulating proinflammatory and anti-inflammatory cytokines. In the present study and due to efficacy reasons, we are exploring only two of these compounds, namely, ZM4 and ZM5, to reveal their analgesic activity and toxicity. Following oral administration, both compounds were effective in reducing significantly (P < 0.05–0.001) acetic acid-induced writhing behavior, hot plate latency test, and formalin-induced paw licking time as antinociceptive indicators in mice and rats, respectively. Regarding the toxicity, the acute (20, 50, and 150 mg/kg) and repeated oral administration (10, 20, and 50 mg/kg) of these compounds for ten days did not produce any mortality and the compounds were considered well tolerated. However, repeated oral administration of 50 mg/kg of both compounds induced erythropoiesis by means of increasing significantly red blood cells, hemoglobin, and packed cell volume. Moreover, these compounds did not induce gastric lesions in the stomach of experimental animals at the doses that exhibited analgesic and anti-inflammatory activity compared to indomethacin as a positive control. The results indicate that ZM4 and ZM5 possess potential analgesic activity while being preliminarily safe and have minimal ulcerogenic activity.

Ketoprofen-liposomes formulation for clinical therapy

Lipid (L-α-phosphatidylcholine) was used in liposome-ketoprofen formulation to obtain vesicles systems characterized by a net positive charge along the liposomal surface. A careful analysis of vesicles formation and systems stability was made. Dynamic stability and specificity of liposomes disruption and prolonged release of ketoprofen was provided by steric effect accomplished on the vesicle surface by chitosan molecules, which were introduced into the system additionally. The retardation effect of the liposomes containing ketoprofen was tested in vitro and in vivo. The studies have shown that the liposomes containing ketoprofen obtained are characterized by a net positive charge and an average diameter of 1,287 nm for dialyzed solutions (pH 7.40). This formulation presents in vivo significant antinociceptive effects starting at 90 min, with a maximum intensity between 2 and 8 h, prolonged more than 10 h, and an analgesic activity within 3-4 h.

Enhancement of Antinociception by Co-administrations of Nefopam, Morphine, and Nimesulide in a Rat Model of Neuropathic Pain

Background

Neuropathic pain is a chronic pain due to disorder in the peripheral or central nervous system with different pathophysiological mechanisms. Current treatments are not effective. Analgesic drugs combined can reduce pain intensity and side effects. Here, we studied the analgesic effect of nimesulide, nefopam, and morphine with different mechanisms of action alone and in combination with other drugs in chronic constriction injury (CCI) model of neuropathic pain.

Methods

Male Wistar rats (n = 8) weighing 150-200 g were divided into 3 different groups: 1- Saline-treated CCI group, 2- Saline-treated sham group, and 3- Drug-treated CCI groups. Nimesulide (1.25, 2.5, and 5 mg/kg), nefopam (10, 20, and 30 mg/kg), and morphine (1, 3, and 5 mg/kg) were injected 30 minutes before surgery and continued daily to day 14 post-ligation. In the combination strategy, a nonanalgesic dose of drugs was used in combination such as nefopam + morphine, nefopam + nimesulide, and nimesulide + morphine. Von Frey filaments for mechanical allodynia and acetone test for cold allodynia were, respectively, used as pain behavioral tests. Experiments were performed on day 0 (before surgery) and days 1, 3, 5, 7, 10, and 14 post injury.

Results

Nefopam (30 mg/kg) and nimesulide (5 mg/kg) blocked mechanical and thermal allodynia; the analgesic effects of morphine (5 mg/kg) lasted for 7 days. Allodynia was completely inhibited in combination with nonanalgesic doses of nefopam (10 mg/kg), nimesulide (1.25 mg/kg), and morphine (3 mg/kg).

Conclusions

It seems that analgesic drugs used in combination, could effectively reduce pain behavior with reduced adverse effects.

Ketoprofen produces modality-specific inhibition of pain behaviors in rats after plantar incision

BACKGROUND

Postoperative pain remains a significant problem despite optimal treatment with current drugs. Nonsteroidal antiinflammatory drugs reduce inflammation and provide analgesia but are associated with adverse side effects.

METHODS

We tested low doses (0.5-5 mg/kg) of parenteral ketoprofen against pain-related behaviors after plantar incision in rats. To further evaluate the potential sites of action of ketoprofen in our model, a novel, sustained-release microparticle formulation of ketoprofen was placed into the wound, and tested for its effects on pain behaviors. Intrathecal ketoprofen (150 microg) was also studied. Plasma samples were assayed for drug concentrations.

RESULTS

We found that low doses of parenterally administered ketoprofen produced a modality-specific effect on pain behaviors; guarding after incision was decreased, whereas no inhibition of exaggerated responses to heat or mechanical stimuli was evident. Very low doses, 0.5 mg/kg, could produce inhibition of guarding. The locally applied sustained-release ketoprofen-eluting microparticles and intrathecally administered ketoprofen also produced a modality-specific effect on pain behaviors after incision, inhibiting only guarding. Plasma levels of ketoprofen after parenteral or local administration were in the range of therapeutic blood levels in postoperative patients.

CONCLUSIONS

This study demonstrates that ketoprofen is an effective analgesic for nonevoked guarding in rats after plantar incision. There was no effect on mechanical or heat responses, which highlights the importance of multiple-modality testing of pain behaviors for drug evaluation. We found efficacy at doses used clinically in postoperative patients.

Nefopam but not physostigmine affects the thermoregulatory response in mice via alpha(2)-adrenoceptors

Nefopam, a non-opioid, centrally acting benzoxazocine analgesic, proved to be as efficient in treatment of postanaesthetic thermoregulatory shivering as clonidine or meperidine. However, its exact mechanism of action is still unclear. Potent anti-shivering activity was also demonstrated for physostigmine primarily based on cholinergic but probably also different additional mechanisms of action. Hypothesizing an involvement of alpha(2)-adrenoceptors we studied their role in nefopam- and physostigmine-mediated thermoregulation in a mouse model of nonshivering thermogenesis. To differentiate possible alpha(2)-adrenoceptor subtype-specific interactions, we analysed wildtype mice and mice with deletion of the alpha(2A)-, alpha(2B)- or alpha(2C)-adrenoceptor (knock out). Ten mice of each genotype (n = 40) were administered saline, saline plus atipamezole, 1 mg/kg nefopam, 25 mg/kg nefopam, 25 mg/kg nefopam plus atipamezole, physostigmine and physostigmine plus atipamezole intraperitoneally. Each mouse was randomly subjected to each of the seven different treatments. Afterwards, the mice were positioned into a plexiglas chamber where rectal temperature and mixed expired carbon dioxide were measured during following whole body cooling. Thermoregulatory threshold temperature of nonshivering thermogenesis and maximum response intensity were analysed. Nefopam decreased the thermoregulatory threshold temperature in wildtype, alpha(2B)- and alpha(2C)-adrenoceptor mice. This effect was partially abolished by additional administration of the alpha(2)-adrenoceptor antagonist atipamezole. In alpha(2A)-adrenoceptor knock out mice, nefopam did not affect the thermoregulatory threshold. In contrast, physostigmine decreased the thermoregulatory threshold in wildtype and all alpha(2)-adrenoceptor knock out mice independently from additional atipamezole administration. Our results indicate an important role of the alpha(2A)-adrenoceptor in the thermoregulatory response induced by nefopam but not by physostigmine in mice.