Lumbar degenerative spondylolisthesis: role of sagittal alignment.

PURPOSE: To evaluate the sagittal alignment of the lumbar spine in patients with degenerative spondylolisthesis at the L4-5 level. METHODS: Patients with untreated degenerative spondylolisthesis at L4-5 were retrospectively identified from the clinical practice of spine surgeons at an academic medical center. All patients had standing X-rays that were reviewed by the senior surgeon to confirm the presence of degenerative spondylolisthesis at L4-5. Radiographs were analyzed for the following: lumbar lordosis (LL), lower lumbar lordosis (L4-S1; LLL), L5-S1 lordosis, pelvic incidence (PI), and pelvic tilt (PT). From these measurements, lumbar distribution index (LLL/LL × 100; LDI), ideal lumbar lordosis (PI × 0.62 + 29; ILL), PI-LL mismatch, and relative lumbar lordosis (LL-ILL; RLL) were calculated. These parameters were used to evaluate the sagittal alignment of the lumbar spine. Normal alignment was defined based on previous studies and clinical experience. RESULTS: 117 participants met inclusion criteria, with an average age of 67.2 years. The majority of the cohort demonstrated hypolordotic sagittal alignment of the L5-S1 segment when assessed in relation to ILL, PI, and LL (73.5%, 61.5%, and 50.4% respectively). Evaluation of the lower lumbar spine (L4-S1) demonstrated normal sagittal alignment when evaluated via LDI and LLL (65%, 52.1%, respectively), suggesting the presence of compensatory hyperextension at L4-5 in response to the L5-S1 hypolordosis. Consequently, normal sagittal alignment of the regional lumbar spine was maintained when evaluated using LL, PI-LL mismatch, and RLL (51.3%, 47%, and 62.4% respectively). CONCLUSIONS: This study demonstrates that there is a high incidence of relative hypolordosis at the L5-S1 level among patients who present with degenerative spondylolisthesis at L4-5. The L5-S1 hypolordosis is associated with L4-5 hyperlordosis, such that the lower lumbar lordosis (L4-S1; LLL) and regional lumbar lordosis (LL) are still within normal range. It is probable that L5-S1 hypolordosis was the initial pathologic event that incited compensatory L4-5 hyperlordosis, which in turn may have led to facet degeneration and laxity, and eventually to development of spondylolisthesis.

Doxycycline-Induced Changes in Circulating MMP or TIMP2 Levels Are Not Associated with Skeletal-Related Event-Free or Overall Survival in Patients with Bone Metastases from Breast Cancer.

Doxycycline is often used as a promoter of inducible gene expression in preclinical models; however, it can also have direct effects on tumor growth and survival. This is due in part to its ability to inhibit cell invasion and regulate matrix metalloproteinase (MMP) expression. Given that doxycycline is also osteotropic, a clinical study to assess its effects on modulation of tumor progression or prevention of skeletal-related events (SRE) in patients with bone metastases from breast cancer (the Achilles trial) was undertaken. Patients received 100 mg of oral doxycycline twice daily for 12 weeks, with serum obtained at baseline and 4, 8 and 12 weeks post-initiation of doxycycline treatment. Exploratory analysis of the effects of doxycycline on circulating levels of MMP or tissue inhibitor of matrix metalloproteinase 2 (TIMP2) was performed in enrolled patients. Statistically significant associations were observed between MMP2, MMP9 and TIMP2 at baseline with significant associations maintained between absolute levels and changes in levels of MMP2 and TIMP2 at weeks 4-12 post initiation of doxycycline. Treatment with doxycycline generally resulted in decreases in MMP2 and MMP9 levels with concurrent upregulation of TIMP2 at 12 weeks post-initiation of doxycycline treatment. Despite this, we observed no association with the levels of any of these factors with either SRE-free or overall survival in this patient cohort. In summary, despite observing hypothesized effects of doxycycline administration on surrogate markers of its anti-tumor activity, measures of circulating levels of these biomarkers were not prognostic in this patient population.

Differences and Similarities in Spontaneous Activity Between Animal Models of Cancer-Induced Pain and Neuropathic Pain.

Background: Clinical data on cancer-induced pain (CIP) demonstrate widespread changes in sensory function. It is characterized in humans not only by stimulus-invoked pain, but also by spontaneous pain. In our previous studies in an animal model of CIP, we observed changes in intrinsic membrane properties and excitability of dorsal root ganglion (DRG) sensory neurons corresponding to mechanical allodynia and hyperalgesia, of which abnormal activities of Aß-fiber sensory neurons are consistent in a rat model of peripheral neuropathic pain (NEP). Objective: To investigate whether there are related peripheral neural mechanisms between the CIP and NEP models of spontaneous pain, we compared the electrophysiological properties of DRG sensory neurons at 2-3 weeks after CIP and NEP model induction. Methods: CIP models were induced with metastasis tumour-1 rat breast cancer cells implanted into the distal epiphysis of the femur. NEP models were induced with a polyethylene cuff implanted around the sciatic nerve. Spontaneous pain in animals is measured by spontaneous foot lifting (SFL). After measurement of SFL, the animals were prepared for electrophysiological recordings of spontaneous activity (SA) in DRG neurons in vivo. Results: Our data showed that SFL and SA occurred in both models. The proportion of SFL and SA of C-fiber sensory neurons in CIP was more significantly increased than in NEP models. There was no difference in duration of SFL and the rate of SA between the two models. The duration of SFL is related to the rate of SA in C-fiber in both models. Conclusion: Thus, SFL may result from SA activity in C-fiber neurons in CIP and NEP rats. The differences and similarities in spontaneous pain between CIP and NEP rats is related to the proportion and rate of SA in C-fibers, respectively.

Microbial exposure during early human development primes fetal immune cells.

The human fetal immune system begins to develop early during gestation; however, factors responsible for fetal immune-priming remain elusive. We explored potential exposure to microbial agents in utero and their contribution toward activation of memory T cells in fetal tissues. We profiled microbes across fetal organs using 16S rRNA gene sequencing and detected low but consistent microbial signal in fetal gut, skin, placenta, and lungs in the 2nd trimester of gestation. We identified several live bacterial strains including Staphylococcus and Lactobacillus in fetal tissues, which induced in vitro activation of memory T cells in fetal mesenteric lymph node, supporting the role of microbial exposure in fetal immune-priming. Finally, using SEM and RNA-ISH, we visualized discrete localization of bacteria-like structures and eubacterial-RNA within 14th weeks fetal gut lumen. These findings indicate selective presence of live microbes in fetal organs during the 2nd trimester of gestation and have broader implications toward the establishment of immune competency and priming before birth.

Effect of Early Treatment With Hydroxychloroquine or Lopinavir and Ritonavir on Risk of Hospitalization Among Patients With COVID-19: The TOGETHER Randomized Clinical Trial.

Importance: Data on the efficacy of hydroxychloroquine or lopinavir-ritonavir for the treatment of high-risk outpatients with COVID-19 in developing countries are needed. Objective: To determine whether hydroxychloroquine or lopinavir-ritonavir reduces hospitalization among high-risk patients with early symptomatic COVID-19 in an outpatient setting. Design, Setting, and Participants: This randomized clinical trial was conducted in Brazil. Recently symptomatic adults diagnosed with respiratory symptoms from SARS-CoV-2 infection were enrolled between June 2 and September 30, 2020. The planned sample size was 1476 patients, with interim analyses planned after 500 patients were enrolled. The trial was stopped after the interim analysis for futility with a sample size of 685 patients. Statistical analysis was performed in December 2020. Interventions: Patients were randomly assigned to hydroxychloroquine (800 mg loading dose, then 400 mg daily for 9 days), lopinavir-ritonavir (loading dose of 800 mg and 200 mg, respectively, every 12 hours followed by 400 mg and 100 mg, respectively, every 12 hours for the next 9 days), or placebo. Main Outcomes and Measures: The primary outcomes were COVID-19-associated hospitalization and death assessed at 90 days after randomization. COVID-19-associated hospitalization was analyzed with a Cox proportional hazards model. The trial included the following secondary outcomes: all-cause hospitalization, viral clearance, symptom resolution, and adverse events. Results: Of 685 participants, 632 (92.3%) self-identified as mixed-race, 377 (55.0%) were women, and the median (range) age was 53 (18-94) years. A total of 214 participants were randomized to hydroxychloroquine; 244, lopinavir-ritonavir; and 227, placebo. At first interim analysis, the data safety monitoring board recommended stopping enrollment of both hydroxychloroquine and lopinavir-ritonavir groups because of futility. The proportion of patients hospitalized for COVID-19 was 3.7% (8 participants) in the hydroxychloroquine group, 5.7% (14 participants) in the lopinavir-ritonavir group, and 4.8% (11 participants) in the placebo group. We found no significant differences between interventions for COVID-19-associated hospitalization (hydroxychloroquine: hazard ratio [HR], 0.76 [95% CI, 0.30-1.88]; lopinavir-ritonavir: HR, 1.16 [95% CI, 0.53-2.56] as well as for the secondary outcome of viral clearance through day 14 (hydroxychloroquine: odds ratio [OR], 0.91 [95% CI, 0.82-1.02]; lopinavir-ritonavir: OR, 1.04 [95% CI, 0.94-1.16]). At the end of the trial, there were 3 fatalities recorded, 1 in the placebo group and 2 in the lopinavir-ritonavir intervention group. Conclusions and Relevance: In this randomized clinical trial, neither hydroxychloroquine nor lopinavir-ritonavir showed any significant benefit for decreasing COVID-19-associated hospitalization or other secondary clinical outcomes. This trial suggests that expedient clinical trials can be implemented in low-income settings even during the COVID-19 pandemic. Trial Registration: ClinicalTrials.gov Identifier: NCT04403100.

Electrochemical sensing: A prognostic tool in the fight against COVID-19.

The COVID-19 pandemic has devastated the world, despite all efforts in infection control and treatment/vaccine development. Hospitals are currently overcrowded, with health statuses of patients often being hard to gauge. Therefore, methods for determining infection severity need to be developed so that high-risk patients can be prioritized, resources can be efficiently distributed, and fatalities can be prevented. Electrochemical prognostic biosensing of various biomarkers may hold promise in solving these problems as they are low-cost and provide timely results. Therefore, we have reviewed the literature and extracted the most promising biomarkers along with their most favourable electrochemical sensors. The biomarkers discussed in this paper are C-reactive protein (CRP), interleukins (ILs), tumour necrosis factor alpha (TNFα), interferons (IFNs), glutamate, breath pH, lymphocytes, platelets, neutrophils and D-dimer. Metabolic syndrome is also discussed as comorbidity for COVID-19 patients, as it increases infection severity and raises chances of becoming infected. Cannabinoids, especially cannabidiol (CBD), are discussed as a potential adjunct therapy for COVID-19 as their medicinal properties may be desirable in minimizing the neurodegenerative or severe inflammatory damage caused by severe COVID-19 infection. Currently, hospitals are struggling to provide adequate care; thus, point-of-care electrochemical sensor development needs to be prioritized to provide an approximate prognosis for hospital patients. During and following the immediate aftermath of the pandemic, electrochemical sensors can also be integrated into wearable and portable devices to help patients monitor recovery while returning to their daily lives. Beyond the COVID-19 pandemic, these sensors will also prove useful for monitoring inflammation-based diseases such as cancer and cardiovascular disease.

Performance Outcomes and Return-to-Sport Rate of National Hockey League Athletes Vary After Common Orthopedic Surgical Procedures.

OBJECTIVE: Evaluate performance-based outcomes and return-to-sport rate in National Hockey League (NHL) athletes. DESIGN: Retrospective cohort study. SETTING: Public records. No direct patient care was provided. PARTICIPANTS: National Hockey League athletes who underwent different orthopedic procedures were identified using public records. Three hundred thirty-seven athletes met inclusion criteria. INDEPENDENT VARIABLES: Common orthopedic surgical procedures in NHL athletes. MAIN OUTCOME MEASURES: Return-to-play and preoperative and postoperative performance measures were collected to calculate a position-specific performance score. Short-term and medium-term outcomes were defined as 1 and 2 to 3 seasons after surgery, respectively. RESULTS: Three hundred seven athletes (92.6%) successfully returned to play. The number of games played during the first season after surgery compared with baseline was significantly decreased for hip arthroscopy (HA), noninstability shoulder arthroscopy (ie, shoulder arthroscopy procedure to address pathology other than shoulder instability), knee arthroscopy, and sports hernia repair (P = 0.002, 0.009, 0.03, and 0.01, respectively). The number of games played for seasons 2 and 3 after surgery was significantly decreased for both HA and noninstability shoulder arthroscopy (P = 0.01 and 0.001, respectively). Short-term postoperative performance scores were significantly decreased for HA, noninstability shoulder arthroscopy, and anterior cruciate ligament reconstruction (P = 0.00004, 0.02, and 0.02, respectively) while medium-term scores were significantly decreased for HA only (P = 0.009). CONCLUSIONS: National Hockey League athletes return to play at a high rate after common orthopedic surgeries. However, certain procedures portend poorer performance scores and game participation than others. In particular, HA and noninstability shoulder arthroscopy have the greatest negative effect on NHL careers after surgery.

Sexual assault reporting amongst users of online sexual health services.

Sexual assault (SA) survivors often attend sexual health clinics (SHC) for care relating to their assault. Reported rates of SA amongst SHC attendees can be high. Online sexual health services are becoming increasingly popular. Sexual Health London (SHL) is a large online sexual transmitted infection (STI) screening service. Between 1.1.20- 8.2.20, 0.5% (242/45841) (54% female, 45.6% male) of adults disclosed a recent SA when ordering an online STI testing kit. 79% (192/242) users engaged in a call back discussion initiated by the SHL team: 45% (87/192) users confirmed a SA had occurred and 53% (101/242) users denied an assault (particularly men) stating they had reported this in error. 18% (16/87) users had already reported their SA to the police/sexual assault centre, and one user accepted an onward referral. This study found a low reporting rate of SA amongst SHL users, but despite a high response rate to call backs, >50% cited they reported in error, 25% (22/87) didn't want to discuss their SA and few accepted onward referrals. Using e-triage to screen for SA followed by service-initiated telephonic support to everyone who discloses, may not be acceptable or offer utility to all. Further evaluation of ways to engage these individuals is required.

Sex differences in neuro(auto)immunity and chronic sciatic nerve pain.

Chronic pain occurs with greater frequency in women, with a parallel sexually dimorphic trend reported in sufferers of many autoimmune diseases. There is a need to continue examining neuro-immune-endocrine crosstalk in the context of sexual dimorphisms in chronic pain. Several phenomena in particular need to be further explored. In patients, autoantibodies to neural antigens have been associated with sensory pathway hyper-excitability, and the role of self-antigens released by damaged nerves remains to be defined. In addition, specific immune cells release pro-nociceptive cytokines that directly influence neural firing, while T lymphocytes activated by specific antigens secrete factors that either support nerve repair or exacerbate the damage. Modulating specific immune cell populations could therefore be a means to promote nerve recovery, with sex-specific outcomes. Understanding biological sex differences that maintain, or fail to maintain, neuroimmune homeostasis may inform the selection of sex-specific treatment regimens, improving chronic pain management by rebalancing neuroimmune feedback. Given the significance of interactions between nerves and immune cells in the generation and maintenance of neuropathic pain, this review focuses on sex differences and possible links with persistent autoimmune activity using sciatica as an example.

Onco-fetal Reprogramming of Endothelial Cells Drives Immunosuppressive Macrophages in Hepatocellular Carcinoma.

We employed scRNA sequencing to extensively characterize the cellular landscape of human liver from development to disease. Analysis of ∼212,000 cells representing human fetal, hepatocellular carcinoma (HCC), and mouse liver revealed remarkable fetal-like reprogramming of the tumor microenvironment. Specifically, the HCC ecosystem displayed features reminiscent of fetal development, including re-emergence of fetal-associated endothelial cells (PLVAP/VEGFR2) and fetal-like (FOLR2) tumor-associated macrophages. In a cross-species comparative analysis, we discovered remarkable similarity between mouse embryonic, fetal-liver, and tumor macrophages. Spatial transcriptomics further revealed a shared onco-fetal ecosystem between fetal liver and HCC. Furthermore, gene regulatory analysis, spatial transcriptomics, and in vitro functional assays implicated VEGF and NOTCH signaling in maintaining onco-fetal ecosystem. Taken together, we report a shared immunosuppressive onco-fetal ecosystem in fetal liver and HCC. Our results unravel a previously unexplored onco-fetal reprogramming of the tumor ecosystem, provide novel targets for therapeutic interventions in HCC, and open avenues for identifying similar paradigms in other cancers and disease.

Evaluation of the preclinical analgesic efficacy of naturally derived, orally administered oil forms of Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), and their 1:1 combination.

Chronic neuropathic pain (NP) is a growing clinical problem for which effective treatments, aside from non-steroidal anti-inflammatory drugs and opioids, are lacking. Cannabinoids are emerging as potentially promising agents to manage neuroimmune effects associated with nociception. In particular, Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), and their combination are being considered as therapeutic alternatives for treatment of NP. This study aimed to examine whether sex affects long-term outcomes on persistent mechanical hypersensitivity 7 weeks after ceasing cannabinoid administration. Clinically relevant low doses of THC, CBD, and a 1:1 combination of THC:CBD extracts, in medium chain triglyceride (MCT) oil, were orally gavaged for 14 consecutive days to age-matched groups of male and female sexually mature Sprague Dawley rats. Treatments commenced one day after surgically inducing a pro-nociceptive state using a peripheral sciatic nerve cuff. The analgesic efficacy of each phytocannabinoid was assessed relative to MCT oil using hind paw mechanical behavioural testing once a week for 9 weeks. In vivo intracellular electrophysiology was recorded at endpoint to characterize soma threshold changes in primary afferent sensory neurons within dorsal root ganglia (DRG) innervated by the affected sciatic nerve. The thymus, spleen, and DRG were collected post-sacrifice and analyzed for long-term effects on markers associated with T lymphocytes at the RNA level using qPCR. Administration of cannabinoids, particularly the 1:1 combination of THC, elicited a sustained mechanical anti-hypersensitive effect in males with persistent peripheral NP, which corresponded to beneficial changes in myelinated Aß mechanoreceptive fibers. Specific immune cell markers associated with T cell differentiation and pro-inflammatory cytokines, previously implicated in repair processes, were differentially up-regulated by cannabinoids in males treated with cannabinoids, but not in females, warranting further investigation into sexual dimorphisms that may underlie treatment outcomes.

Correction: Glutamate sensing in biofluids: recent advances and research challenges of electrochemical sensors.

Correction for 'Glutamate sensing in biofluids: recent advances and research challenges of electrochemical sensors' by Jessica Schultz et al., Analyst, 2020, 145, 321-347. DOI: 10.10.1039/C9AN01609K.

Applying Serum Cytokine Levels to Predict Pain Severity in Cancer Patients.

BACKGROUND AND AIM: Cancers originating in the breast, lung and prostate often metastasize to the bone, frequently resulting in cancer-induced bone pain that can be challenging to manage despite conventional analgesic therapy. This exploratory study's aim was to identify potential biomarkers associated with cancer-induced pain by examining a sample population of breast cancer patients undergoing bisphosphonate therapy. METHODS: A secondary analysis of the primary study was performed to quantify serum cytokine levels for correlation to pain scores. Cytokines with statistically significant correlations were then input into a stepwise regression analysis to generate a predictive equation for a patient's pain severity. In an effort to find additional potential biomarkers, correlation analysis was performed between these factors and a more comprehensive panel of cytokines and chemokines from breast, lung, and prostate cancer patients. RESULTS: Statistical analysis identified nine cytokines (GM-CSF, IFNγ, IL-1ß, IL-2, IL-4, IL-5, IL-12p70, IL-17A, and IL-23) that had significant negative correlations with pain scores and they could best predict pain severity through a predictive equation generated for this specific evaluation. After performing a correlation analysis between these factors and a larger panel of cytokines and chemokines, samples from breast, lung and prostate patients showed distinct correlation profiles, highlighting the clinical challenge of applying pain-associated cytokines related to more defined nociceptive states, such as arthritis, to a cancer pain state. CONCLUSION: Exploratory analyses such as the ones presented here will be a beneficial tool to expand insights into potential cancer-specific nociceptive mechanisms and to develop novel therapeutics.

Electrochemical Sensing of Cannabinoids in Biofluids: A Noninvasive Tool for Drug Detection.

Cannabinoid sensing in biofluids provides great insight into the effects of medicinal cannabis on the body. The prevalence of cannabis for pain management and illicit drug use necessitates knowledge translation in cannabinoids. In this Review, we provide an overview of the current detection methods of cannabinoids in bodily fluids emphasizing electrochemical sensing. First, we introduce cannabinoids and discuss the structure and metabolism of Δ9-THC and its metabolites in relation to blood, urine, saliva, sweat, and breath. Next, we briefly discuss lab based techniques for cannabinoids in biofluids. While these techniques are highly sensitive and specific, roadside safety requires a quick, portable, and cost-effective sensing method. These needs motivated a comprehensive review of advantages, disadvantages, and future directions for electrochemical sensing of cannabinoids. The literature shows the lowest limit of detection to be 3.3 pg of Δ9-THC/mL using electrochemical immunosensors, while electrodes fabricated with low cost methods such as screen-printing and carbon paste can detect as little as 25 and 1.26 ng of Δ9-THC/mL, respectively. Future research will include nanomaterial modified working electrodes, for simultaneous sensing of multiple cannabinoids. Additionally, there should be an emphasis on selectivity for cannabinoids in the presence of interfering compounds. Sensors should be fully integrated on biocompatible substrates with control electronics and intelligent components for wearable diagnostics. We hope this Review will prove to be the seminal work in the electrochemical sensing of cannabinoids.

An evaluation of the anti-hyperalgesic effects of cannabidiolic acid-methyl ester in a preclinical model of peripheral neuropathic pain.

BACKGROUND AND PURPOSE: Chronic neuropathic pain (NEP) is associated with growing therapeutic cannabis use. To promote quality of life without psychotropic effects, cannabinoids other than Δ9-tetrahydrocannabidiol, including cannabidiol and its precursor cannabidiolic acid (CBDA), are being evaluated. Due to its instability, CBDA has been understudied, particularly as an anti-nociceptive agent. Adding a methyl ester group (CBDA-ME) significantly enhances its stability, facilitating analyses of its analgesic effects in vivo. This study examines early treatment efficacy of CBDA-ME in a rat model of peripherally induced NEP and evaluates sex as a biological variable. EXPERIMENTAL APPROACH: After 14 consecutive days of intraperitoneal CBDA-ME administration at 0.01, 0.1 and 1 µg·kg-1 , commencing 1 day after surgically implanting a sciatic nerve-constricting cuff to induce NEP, the anti-nociceptive efficacy of this cannabinoid was assessed in male and female Sprague-Dawley rats relative to vehicle-treated counterparts. In females, 2 and 4 µg·kg-1 daily doses of CBDA-ME were also evaluated. Behavioural tests were performed for hind paw mechanical and thermal withdrawal thresholds once a week for 8 weeks. At endpoint, in vivo electrophysiological recordings were obtained to characterize soma threshold changes in primary sensory neurons. KEY RESULTS: In males, CBDA-ME elicited a significant concentration-dependent chronic anti-hyperalgesic effect, also influencing both nociceptive and non-nociceptive mechanoreceptors, which were not observed in females at any of the concentrations tested. CONCLUSION AND IMPLICATIONS: Initiating treatment of a peripheral nerve injury with CBDA-ME at an early stage post-surgery provides anti-nociception in males, warranting further investigation into potential sexual dimorphisms underlying this response.

Response to pregabalin and progesterone differs in male and female rat models of neuropathic and cancer pain.

Background: Cancer pain involves nervous system damage and pathological neurogenesis. Neuropathic pain arises from damage to the nervous system and is driven by ectopic signaling. Both progesterone and pregabalin are neuroprotective in animal models, and there is evidence that both drugs bind to and inhibit voltage-gated calcium channels. Aims: This study was designed to characterize the effects of progesterone and pregabalin in preclinical models of cancer and neuropathic pain in both sexes. Methods: We measured peripheral sensory signaling by intracellular in vivo electrophysiology and behavioral indicators of pain in rat models of cancer-induced bone pain and neuropathic pain. Results: Female but not male models of cancer pain showed a behavioral response to treatment and pregabalin reduced excitability in C and A high-threshold but not low-threshold sensory neurons of both sexes. Male models of neuropathic pain treated with pregabalin demonstrated higher signaling thresholds only in A high-threshold neurons, and behavioral data indicated a clear recovery to baseline mechanical withdrawal thresholds in all treatment groups. Female rat treatment groups did not show excitability changes in sensory neurons, but all demonstrated higher mechanical withdrawal thresholds than vehicle-treated females, although not to baseline levels. Athymic female rat models of neuropathic pain showed no behavioral or electrophysiological responses to treatment. Conclusions: Both pregabalin and progesterone showed evidence of efficacy in male models of neuropathic pain. These results add to the evidence demonstrating differential effects of treatments for pain in male and female animals and widely differing responses in models of cancer and neuropathic pain.

Contexte: La douleur cancéreuse implique des lésions du système nerveux et une neurogenèse pathologique. La douleur neuropathique résulte d'une lésion du système nerveux et est provoquée par une signalisation ectopique. La progestérone et la prégabaline sont toutes deux neuroprotectrices dans les modèles animaux et il est prouvé que ces deux médicaments se lient aux canaux calciques à tension contrôlée et les inhibent.Objectifs: Cette étude visait à caractériser les effets de la progestérone et de la prégabaline dans des modèles précliniques de cancer et de douleur neuropathique chez les deux sexes.Méthodes: Nous avons mesuré la signalisation sensorielle périphérique par électrophysiologie intracellulaire in vivo, ainsi que les indicateurs comportementaux de la douleur dans des modèles de rats atteints de douleurs osseuses et de douleurs neuropathiques induites par le cancer.Résultats: Contrairement aux modèles masculins, les modèles féminins atteints de douleur cancéreuse ont montré une réponse comportementale au traitement, tandis que la prégabaline a réduit l'excitabilité des neurones sensoriels C et A à seuil élevé mais non à seuil bas chez les deux sexes. Les modèles masculins atteints de douleur neuropathique traités à la prégabaline ont montré des seuils de signalisation plus élevés uniquement dans les neurones A à seuil élevé, tandis que les données comportementales ont indiqué un net retour aux seuils de retrait mécanique de départ dans tous les groupes de traitement. Les groupes de rats femelles traités n'ont pas montré de changements d'excitabilité dans les neurones sensoriels, mais tous ont montré des seuils de retrait mécanique plus élevés que les femelles traitées avec le vecteur, sans toutefois atteindre les niveaux de départ. Les modèles atteints de douleur neuropathique parmi les rats femelles athymiques n'ont montré aucune réponse comportementale ou électrophysiologique au traitement.Conclusions: La prégabaline et la progestérone ont toutes deux démontré leur efficacité dans les modèles masculins atteints de douleur neuropathique. Ces résultats s'ajoutent aux données probantes démontrant les effets différentiels des traitements de la douleur chez les animaux mâles et femelles, et les réponses très différentes dans les modèles atteints de cancer et de douleur neuropathique.

3D-Printed Ceramic-Demineralized Bone Matrix Hyperelastic Bone Composite Scaffolds for Spinal Fusion.

Although numerous spinal biologics are commercially available, a cost-effective and safe bone graft substitute material for spine fusion has yet to be proven. In this study, "3D-Paints" containing varying volumetric ratios of hydroxyapatite (HA) and human demineralized bone matrix (DBM) in a poly(lactide-co-glycolide) elastomer were three-dimensional (3D) printed into scaffolds to promote osteointegration in rats, with an end goal of spine fusion without the need for recombinant growth factor. Spine fusion was evaluated by manual palpation, and osteointegration and de novo bone formation within scaffold struts were evaluated by laboratory and synchrotron microcomputed tomography and histology. The 3:1 HA:DBM composite achieved the highest mean fusion score and fusion rate (92%), which was significantly greater than the 3D printed DBM-only scaffold (42%). New bone was identified extending from the host transverse processes into the scaffold macropores, and osteointegration scores correlated with successful fusion. Strikingly, the combination of HA and DBM resulted in the growth of bone-like spicules within the DBM particles inside scaffold struts. These spicules were not observed in DBM-only scaffolds, suggesting that de novo spicule formation requires both HA and DBM. Collectively, our work suggests that this recombinant growth factor-free composite shows promise to overcome the limitations of currently used bone graft substitutes for spine fusion. Impact Statement Currently, there exists a no safe, yet highly effective, bone graft substitute that is well accepted for use in spine fusion procedures. With this work, we show that a three-dimensional printed scaffold containing osteoconductive hydroxyapatite and osteoinductive demineralized bone matrix that promotes new bone spicule formation, osteointegration, and successful fusion (stabilization) when implemented in a preclinical model of spine fusion. Our study suggests that this material shows promise as a recombinant growth factor-free bone graft substitute that could safely promote high rates of successful fusion and improve patient care.

Glutamate sensing in biofluids: recent advances and research challenges of electrochemical sensors.

Glutamate is a nonessential amino acid and a putative neurotransmitter. When its consumption exceeds its synthesis, it becomes necessary to monitor its levels. Hence, a low-cost, sensitive and real-time monitoring of glutamate to quantify pain and detect neurodegenerative diseases is imperative to improve pharmacotherapy and early diagnosis for health care. While enzymatic electrochemical sensors are promising to address issues in lab-based detection techniques, non-enzymatic sensors are better due to their higher stability and lower cost. In this review, we aim to discuss the recent advances and remaining challenges of sensing glutamate in biofluids. First, we discuss the metabolic routes of glutamate, followed by its transmission processes to the biofluids. Second, we identify the connection of glutamate to pathologies as a potential biomarker. Third, we emphasize electrochemical sensors instantaneously detect glutamate in biofluids in real-time, quantifying pain and monitoring neurodegenerative diseases. The literature shows the concentration of glutamate in biofluids, such as plasma, cerebral spinal fluid, urine, and saliva are in the range of 5-100 µM, 0.5-2 µM, 8.5 (3.3-18.4) µM mM-1 creatinine, and 0.232 ± 0.177 µM respectively. While these concentration levels are sometimes lower than the detection limit of electrochemical sensors, functionalization of the nanomaterials currently being used such as NiO and Co3O4 with carbon nanotubes or beta-cyclodextrin may improve the sensing performance. Another key challenge in the research is to develop relationships between glutamate and biofluids. Finally, we have to advance electrochemical sensors that are compatible to detect glutamate in physiological conditions for long durations of time.

Effect of glutaminase inhibition on cancer-induced bone pain.

PURPOSE: The complex nature of cancer-induced bone pain (CIBP) has led to investigation into cancer-targeted therapies. This has involved targeting glutamate release from the tumor, secreted as a byproduct of antioxidant responses and metabolic disruption. Cancer cells undergo many metabolic changes that result in increased glutamine metabolism and subsequently the production of glutamate. Glutaminase (GLS) is the enzyme that mediates the conversion of glutamine to glutamate and has been shown to be upregulated in many cancer types including malignancies of the breast. This enzyme, therefore, represents another potential therapeutic target for CIBP, one that lies upstream of glutamate secretion. METHODS: A recently developed inhibitor of GLS, CB-839, was tested in an animal model of CIBP induced by intrafemoral MDA-MB-231 xenografts. CIBP behaviors were assessed using Dynamic Weight Bearing and Dynamic Plantar Aesthesiometer readings of mechanical hyperalgesia and allodynia. RESULTS: CB-839 failed to modulate any of the associated nociceptive behaviors induced by intrafemoral MDA-MB-231 tumor growth. Further investigation in vitro revealed the sensitivity of the drug is dependent on the metabolic flexibility of the cell line being tested which can be modulated by cell culture environment. CONCLUSION: Adaptation to metabolic disturbances may explain the failure of CB-839 to exhibit any significant effects in vivo and the metabolic flexibility of the cell line tested should be considered for future investigations studying the metabolic effects of glutaminase inhibition.