Idiopathic Distal Sensory Polyneuropathy and Fibromyalgia Syndrome: A Comparative Phenotyping Study.

INTRODUCTION: Painful idiopathic distal sensory polyneuropathy (IDSP) and fibromyalgia syndrome (FMS) are cryptogenic chronic pain syndromes. The contribution of small fibre pathology (SFP) in FMS remains controversial. This study aims to quantify small nerve pathology in participants with IDSP and FMS and identify relationships of SFP with sensory phenotypes. METHODS: In this study, 73 individuals (FMS: 25, IDSP: 23, healthy volunteers: 25) underwent comprehensive assessment, including neurological exams, questionnaires, sensory tests, and corneal confocal microscopy. RESULTS: IDSP participants displayed lower wind-up ratio (WUR) relative to FMS (p < 0.001), loss of function to thermal and mechanical stimuli and elevated neuropathy disability scores compared to FMS and healthy volunteers (all p < 0.001). FMS participants demonstrated gain of function to heat and blunt pressure pain responses relative to IDSP, and healthy volunteers (heat: p = 0.002 and p = 0.003; pressure: both p < 0.001) and WUR (both p < 0.001). FMS participants exhibited reduced corneal nerve fibre density (p = 0.02), while IDSP participants had lower global corneal nerve measures (density, branch density, and length) relative to healthy volunteers (all p < 0.001). Utilising corneal nerve fibre length, SFP was demonstrated in 66.6% of participants (FMS: 13/25; IDSP: 22/23). CONCLUSION: Participants with SFP, in both FMS and IDSP, reported symptoms indicative of small nerve fibre disease. Although distinctions in pain distributions are evident between individuals with FMS and IDSP, over 50% of participants between the two conditions displayed both a loss and gain of thermal and mechanical function suggestive of shared mechanisms. However, sensory phenotypes were associated with the presence of SFP in IDSP but not in FMS.

In people with painful idiopathic neuropathy (pain related to nerve damage where the cause of nerve damage is unknown), fibromyalgia syndrome (a long-term condition causing widespread pain), and healthy volunteers, the small nerve fibres of the peripheral nervous system, which may be involved in generating pain were assessed. These nerve fibres can be measured at the front of the eye (cornea) which can provide details on whether they are damaged in the body. The response to temperature, light touch, pressure and pinprick stimuli can also be used to determine if there is a loss or gain of sensation, which may contribute to pain. The aim of this study was to identify the degree of damage to these nerve fibres and to determine whether this damage is associated with a loss (cannot feel or requires more intense stimulus to feel) or gain (stimulus is felt earlier or is painful earlier at lower intensity) of sensory function. The pattern of loss or gain in sensory function is known as a sensory phenotype. It was found that people with painful idiopathic neuropathy had more severe nerve damage, loss of function to temperature and touch, and fewer small nerve fibres in the cornea compared to those with fibromyalgia syndrome and healthy volunteers. People with fibromyalgia syndrome were more sensitive to heat and pressure and had fewer corneal nerve fibres relative to healthy volunteers. The presence of corneal nerve fibre damage was associated with sensory phenotypes (types of sensation felt) in painful idiopathic neuropathy but not in fibromyalgia syndrome.

Automated immunohistochemistry of intra-epidermal nerve fibres in skin biopsies: A proof-of-concept study.

AIMS: To develop a standardised, automated protocol for detecting protein gene product 9.5 (PGP9.5) positive intra-epidermal nerve fibres (IENFs) in skin biopsies, transitioning from the established manual technique to an automated platform. This automated method, although currently intended for research applications, may improve the accessibility of this diagnostic test for small fibre neuropathy in clinical settings. METHODS: Skin biopsies (n = 274) from 100 participants (fibromyalgia syndrome n = 62; idiopathic small fibre neuropathy: n = 16; healthy volunteers: n = 22) were processed using an automated immunohistochemistry platform. IENF quantification was performed by blinded examiners, with reliability assessed via a two-way mixed-effects model to evaluate inter- and intra-observer variability. RESULTS: The automated staining system reproduced intra-epidermal nerve fibre density (IENFD) counts consistent with free-floating sections (mean ± standard deviation: free-floating: 5.6 ± 3.4 fibres/mm; automated: 5.9 ± 3.2 fibres/mm). A median difference of 0.3 with a lower bound 95% Confidence Interval (CI) at -0.00005 established non-inferiority against a margin of -0.4 (p = .08). Specifically, the inter-class correlation coefficient (class denotes consistency in measured observations) was 99% (95% CI: 0.9-1), indicating excellent agreement between free-floating and automated methods. The inter- and intra-class coefficient between examiners were both 99% (95% CI: 0.9-0.1) for IENFD, demonstrating high reliability using sections stained using the automated method. INTERPRETATION: Automated immunohistochemistry provides high-throughput reliable and reproducible intra-epidermal nerve fibre quantification. This method, although currently proof-of-concept, for research use only, may be more widely deployed in histopathology laboratories to increase the adoption of IENFD assessment for the diagnosis of peripheral neuropathies.

Small fibre pathology, small fibre symptoms and pain in fibromyalgia syndrome.

A proportion of people with fibromyalgia demonstrate small fibre pathology (SFP). However, it is unclear how SFP directly relates to pain phenomenology. Thirty-three individuals with FMS and ten healthy volunteers underwent assessment of SFP and sensory phenotyping using corneal confocal microscopy, validated questionnaires and quantitative sensory testing (QST). Corneal nerve fibre length was used to stratify participants with fibromyalgia into with SFP [SFP+] and without SFP [SFP-]. SFP was detected in 50% of the fibromyalgia cohort. Current pain score and QST parameters did not differ between SFP+ and SFP-. Mechanical pain sensitivity (MPS) demonstrated a significant gain-of-function in the SFP- cohort compared to healthy-volunteers (p = 0.014, F = 4.806, η2 = 0.22). Further stratification revealed a cohort without structural SFP but with symptoms compatible with small fibre neuropathy symptoms and a significant gain in function in MPS (p = 0.020 Chi-square). Additionally, this cohort reported higher scores for both depression (p = 0.039, H = 8.483, η2 = 0.312) and anxiety (p = 0.022, F = 3.587, η2 = 0.293). This study confirms that SFP is present in a proportion of people with fibromyalgia. We also show that in a proportion of people with fibromyalgia, small fibre neuropathy symptoms are present in the absence of structural SFP. Greater mechanical pain sensitivity, depression and anxiety are seen in these individuals.

From ray optics to modal analysis: using photonics web simulations to build intuition and address common misconceptions.

The emerging field of silicon photonics has created a large need for Ph.D. photonic integrated circuit design engineers. Developing intuition for electromagnetic waves at the micron scale is a major challenge facing undergraduate and graduate students in photonics. Students often misapply lessons learned from macroscale ray optics to submicron waveguide modes in dielectric structures. In this work, key student misconceptions were identified and addressed in a research study using photonics training simulations. A learning module with interactive 3D vector field visualizations was deployed in a massive open online course to train the next generation of photonics design engineers.

Trigeminal neuropathy presenting secondary to SARS-CoV-2 infection.

Introduction: A 58-year-old woman presented to a multidisciplinary facial pain clinic in October 2021 complaining of a constant pain in the right side of her face since contracting coronavirus SARS-CoV-2 18 months earlier. The pain extending from the right temple down to her right cheek extraorally and including the maxillary teeth and right side of tongue intraorally. This was accompanied by anosmia, diplopia on lateral gaze, and dizziness. Methods: Clinical examination was supplemented with several neurophysiological tests to confirm the diagnosis including an MRI brain scan, quantitative sensory testing, electrophysiological blink reflex testing, corneal confocal microscopy, and pain and short-form anxiety and depression questionnaires. Results: Quantitative sensory testing showed unilateral loss of perception in thermal and mechanical sensibility and bilateral hyperalgesia indicating central sensitization. Bilateral corneal confocal microscopy showed an abnormally reduced corneal nerve fibre length on the right side. MRI, blink reflex, and masseter inhibitory testing findings were normal. Conclusion: This case study is the first case of trigeminal neuropathy related to SARS-CoV-2 infection reported in the literature. It also discusses the successful management of the patient's trigeminal neuropathic pain.

Spinal disinhibition: evidence for a hyperpathia phenotype in painful diabetic neuropathy.

The dominant sensory phenotype in patients with diabetic polyneuropathy and neuropathic pain is a loss of function. This raises questions as to which mechanisms underlie pain generation in the face of potentially reduced afferent input. One potential mechanism is spinal disinhibition, whereby a loss of spinal inhibition leads to increased ascending nociceptive drive due to amplification of, or a failure to suppress, incoming signals from the periphery. We aimed to explore whether a putative biomarker of spinal disinhibition, impaired rate-dependent depression of the Hoffmann reflex, is associated with a mechanistically appropriate and distinct pain phenotype in patients with painful diabetic neuropathy. In this cross-sectional study, 93 patients with diabetic neuropathy underwent testing of Hoffmann reflex rate-dependent depression and detailed clinical and sensory phenotyping, including quantitative sensory testing. Compared to neuropathic patients without pain, patients with painful diabetic neuropathy had impaired Hoffmann reflex rate-dependent depression at 1, 2 and 3 Hz (P ≤ 0.001). Patients with painful diabetic neuropathy exhibited an overall loss of function profile on quantitative sensory testing. However, within the painful diabetic neuropathy group, cluster analysis showed evidence of greater spinal disinhibition associated with greater mechanical pain sensitivity, relative heat hyperalgesia and higher ratings of spontaneous burning pain. These findings support spinal disinhibition as an important centrally mediated pain amplification mechanism in painful diabetic neuropathy. Furthermore, our analysis indicates an association between spinal disinhibition and a distinct phenotype, arguably akin to hyperpathia, with combined loss and relative gain of function leading to increasing nociceptive drive.

Cardiac Autonomic Neuropathy in Type 1 and 2 Diabetes: Epidemiology, Pathophysiology, and Management.

PURPOSE: Cardiac autonomic neuropathy (CAN) is a serious complication of type 1 and type 2 diabetes and is independently associated with major cardiovascular events, morbidity, and mortality. This narrative review examines the epidemiology, pathophysiology, and management and identifies areas of future research to address the challenge posed by CAN. METHODS: We conducted a comprehensive literature search using a range of sources, including the electronic databases PubMed Central, Google Scholar, OVID, and Open Athens, to search for studies on CAN, diabetes mellitus, lifestyle intervention, and cardiovascular risk. We set inclusion criteria to consider review articles or original research published in peer-reviewed journals that examined CAN in diabetes. FINDINGS: Epidemiologic data indicate a varied prevalence of CAN in type 1 and 2 diabetes, with prevalences of 17% to 73%) depending on clinical and demographic factors. Indeed, duration of diabetes and hyperglycemia are the strongest risk factors for CAN development in type 1 diabetes. However, in type 2 diabetes, multifactorial risk factors, including obesity, hypertension, and hyperlipidemia, are associated with the development of CAN. Insulin resistance, which underpins type 2 diabetes and metabolic syndrome, has a direct role in the pathogenesis of CAN. Lifestyle interventions, including dietary measures and tailored exercise programs, have been beneficial in improving cardiac autonomic function primarily measured through heart rate variability. In addition, weight loss through bariatric surgery also improves heart rate variability and may prevent or reduce CAN progression in people living with obesity and concomitant type 2 diabetes. For optimization in type 2 diabetes, both lifestyle and targeted pharmacologic interventions are required to achieve glycemic/metabolic targets, and weight loss is required to prevent or reverse early CAN or prevent the progression to definite and severe CAN. IMPLICATIONS: The focused use of diagnostic testing for CAN, including cardiac autonomic reflex testing in those at high risk of CAN, will enable earlier diagnosis. This testing will allow timely interventions at a reversible stage. Future research should examine targeted early diagnostic testing with subsequent intervention with a combination of lifestyle measures and newer pharmacotherapeutics (eg, sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists), which have produced significant cardiovascular benefit in diabetes.

Is Nerve Electrophysiology a Robust Primary Endpoint in Clinical Trials of Treatments for Diabetic Peripheral Neuropathy?

There is currently no FDA-approved disease-modifying therapy for diabetic peripheral neuropathy (DPN). Nerve conduction velocity (NCV) is an established primary endpoint of disease-modifying therapies in DPN and clinical trials have been powered with an assumed decline of 0.5 m/s/year. This paper sought to establish the time-dependent change in NCV associated with a placebo, compared to that observed in the active intervention group. A literature search identified twenty-one double-blind, randomised controlled trials in DPN of ≥1 year duration conducted between 1971 and 2021. We evaluated changes in neurophysiology, with a focus on peroneal motor and sural sensory NCV and amplitude in the placebo and treatment groups. There was significant variability in the change and direction of change (reduction/increase) in NCV in the placebo arm, as well as variability influenced by the anatomical site of neurophysiological measurement within a given clinical trial. A critical re-evaluation of efficacy trials should consider placebo-adjusted effects and present the placebo-subtracted change in NCV rather than assume a universal annual decline of 0.5 m/s/year. Importantly, endpoints such as corneal confocal microscopy (CCM) have demonstrated early nerve repair, whilst symptoms and NCV have not changed, and should thus be considered as a viable alternative.

Mechanistically informed non-invasive peripheral nerve stimulation for peripheral neuropathic pain: a randomised double-blind sham-controlled trial.

BACKGROUND: Induction of long-term synaptic depression (LTD) is proposed as a treatment mechanism for chronic pain but remains untested in clinical populations. Two interlinked studies; (1) A patient-assessor blinded, randomised, sham-controlled clinical trial and (2) an open-label mechanistic study, sought to examine therapeutic LTD for persons with chronic peripheral nerve injury pain. METHODS: (1) Patients were randomised using a concealed, computer-generated schedule to either active or sham non-invasive low-frequency nerve stimulation (LFS), for 3 months (minimum 10 min/day). The primary outcome was average pain intensity (0-10 Likert scale) recorded over 1 week, at 3 months, compared between study groups. (2) On trial completion, consenting subjects entered a mechanistic study assessing somatosensory changes in response to LFS. RESULTS: (1) 76 patients were randomised (38 per group), with 65 (31 active, 34 sham) included in the intention to treat analysis. The primary outcome was not significant, pain scores were 0.3 units lower in active group (95% CI - 1.0, 0.3; p = 0.30) giving an effect size of 0.19 (Cohen's D). Two non-device related serious adverse events were reported. (2) In the mechanistic study (n = 19) primary outcomes of mechanical pain sensitivity (p = 0.006) and dynamic mechanical allodynia (p = 0.043) significantly improved indicating reduced mechanical hyperalgesia. CONCLUSIONS: Results from the RCT failed to reach significance. Results from the mechanistic study provide new evidence for effective induction of LTD in a clinical population. Taken together results add to mechanistic understanding of LTD and help inform future study design and approaches to treatment. Trial registration ISRCTN53432663.

Chemotherapy-Induced Peripheral Neuropathy: Epidemiology, Pathomechanisms and Treatment.

PURPOSE: This review provides an update on the current clinical, epidemiological and pathophysiological evidence alongside the diagnostic, prevention and treatment approach to chemotherapy-induced peripheral neuropathy (CIPN). FINDINGS: The incidence of cancer and long-term survival after treatment is increasing. CIPN affects sensory, motor and autonomic nerves and is one of the most common adverse events caused by chemotherapeutic agents, which in severe cases leads to dose reduction or treatment cessation, with increased mortality. The primary classes of chemotherapeutic agents associated with CIPN are platinum-based drugs, taxanes, vinca alkaloids, bortezomib and thalidomide. Platinum agents are the most neurotoxic, with oxaliplatin causing the highest prevalence of CIPN. CIPN can progress from acute to chronic, may deteriorate even after treatment cessation (a phenomenon known as coasting) or only partially attenuate. Different chemotherapeutic agents share both similarities and key differences in pathophysiology and clinical presentation. The diagnosis of CIPN relies heavily on identifying symptoms, with limited objective diagnostic approaches targeting the class of affected nerve fibres. Studies have consistently failed to identify at-risk cohorts, and there are no proven strategies or interventions to prevent or limit the development of CIPN. Furthermore, multiple treatments developed to relieve symptoms and to modify the underlying disease in CIPN have failed. IMPLICATIONS: The increasing prevalence of CIPN demands an objective approach to identify at-risk patients in order to prevent or limit progression and effectively alleviate the symptoms associated with CIPN. An evidence base for novel targets and both pharmacological and non-pharmacological treatments is beginning to emerge and has been recognised recently in publications by the American Society of Clinical Oncology and analgesic trial design expert groups such as ACTTION.

Novel and Emerging Electrophysiological Biomarkers of Diabetic Neuropathy and Painful Diabetic Neuropathy.

PURPOSE: Diabetic peripheral neuropathy (DPN) is the most common complication of diabetes. Small and large peripheral nerve fibers can be involved in DPN. Large nerve fiber damage causes paresthesia, sensory loss, and muscle weakness, and small nerve fiber damage is associated with pain, anesthesia, foot ulcer, and autonomic symptoms. Treatments for DPN and painful DPN (pDPN) pose considerable challenges due to the lack of effective therapies. To meet these challenges, there is a major need to develop biomarkers that can reliably diagnose and monitor progression of nerve damage and, for pDPN, facilitate personalized treatment based on underlying pain mechanisms. METHODS: This study involved a comprehensive literature review, incorporating article searches in electronic databases (Google Scholar, PubMed, and OVID) and reference lists of relevant articles with the authors' substantial expertise in DPN. This review considered seminal and novel research and summarizes emerging biomarkers of DPN and pDPN that are based on neurophysiological methods. FINDINGS: From the evidence gathered from 145 papers, this submission describes emerging clinical neurophysiological methods with potential to act as biomarkers for the diagnosis and monitoring of DPN as well as putative future roles as predictors of response to antineuropathic pain medication in pDPN. Nerve conduction studies only detect large fiber damage and do not capture pathology or dysfunction of small fibers. Because small nerve fiber damage is prominent in DPN, additional biomarkers of small nerve fiber function are needed. Activation of peripheral nociceptor fibers using laser, heat, or targeted electrical stimuli can generate pain-related evoked potentials, which are an objective neurophysiological measure of damage along the small fiber pathways. Assessment of nerve excitability, which provides a surrogate of axonal properties, may detect alterations in function before abnormalities are detected by nerve conduction studies. Microneurography and rate-dependent depression of the Hoffmann-reflex can be used to dissect underlying pain-generating mechanisms arising from the periphery and spinal cord, respectively. Their role in informing mechanistic-based treatment of pDPN as well as facilitating clinical trials design is discussed. IMPLICATIONS: The neurophysiological methods discussed, although currently not practical for use in busy outpatient settings, detect small fiber and early large fiber damage in DPN as well as disclosing dominant pain mechanisms in pDPN. They are suited as diagnostic and predictive biomarkers as well as end points in mechanistic clinical trials of DPN and pDPN.

Non-invasive Embryo Assessment: Altered Individual Protein Profile in Spent Culture Media from Embryos Transferred at Day 5.

In order to improve ART outcome, non-invasive embryo assessment is gaining more and more attention. Therefore, the aim of this study is to determine the consecutive implantation potential via the secretome between blastocysts with or without implantation and to analyse possible interactions between these differentially expressed proteins. In this prospective study, 69 spent culture media from blastocysts transferred at day 5 were collected from patients undergoing IVF/ICSI treatment in a single IVF centre between April 2015 and November 2018 after informed consent and analysed individually. Exclusion criteria were the absence of informed consent, PCOS, endometriosis and maternal age > 42 years. Dependent on the treatment outcome, media were subsequently divided into two groups: from embryos who implanted successfully (n = 37) and from embryos without implantation (n = 32). Ninety-two proteins were measured simultaneously using the proximity extension assay (PEA) technology with the Olink® CVD III panel employing oligonucleotide-labelled antibodies. Statistical analysis was performed using the Kolmogorov-Smirnov test, Student's t test, the Mann-Whitney U test and Fisher's exact test. Media from implanted blastocysts showed significantly higher expression of EPHB4, ALCAM, CSTB, BMH, TIMP4, CCL24, SELE, FAS, JAM-A, PON3, PDGF-A, vWF and PECAM-1 compared with media from blastocysts without subsequent implantation. The highest relative expression change could be demonstrated for PECAM-1 and TIMP4. PECAM-1, SELE and vWF were co-expressed. Especially EPHB 4, SELE, ALCAM, MCP-1, CCL24, FAS, JAM-A and PDGF-A have already been described in early embryonic development and metabolism. Therefore, these proteins together with PECAM-1 indicate possible biomarkers for non-invasive embryo assessment in the future. However, due to the innovative methodology, defining a threshold for the use as biomarkers remains to be assessed.

GRN, NOTCH3, FN1, and PINK1 expression in eutopic endometrium - potential biomarkers in the detection of endometriosis - a pilot study.

PURPOSE: Endometriosis (EM) is a common gynecological disease affecting 10-15% of women of reproductive age. However, molecular mechanisms and pathogenesis are still not completely understood. Furthermore, due to the absence of a reliable clinical biomarker, the only viable method for the often-delayed definitive diagnosis is laparoscopic surgery. Our objective was to analyze molecular differences of selected endometrial proteins and genes of women suffering from different stages of EM compared with healthy women to evaluate potential clinical biomarkers. METHODS: We analyzed eutopic endometrial tissue samples from women undergoing a laparoscopic surgery (n = 58). mRNA gene expression of progranulin (GRN), neurogenic locus notch homolog protein (NOTCH3), fibronectin (FN1), and PTEN-induced kinase 1 (PINK1) was analyzed using qRT-PCR. Protein expression was determined using ELISA and immunohistochemistry. RESULTS: Significant differences in gene expression between the different stages of the disease were noted for GRN, NOTCH3, FN1, and PINK1 (p < 0.05). The endometrium of women with minimal EM (ASRM I) showed the highest mRNA expression. Protein levels of GRN and FN1 on the other hand were significantly decreased in the endometrium of women with EM compared with those of healthy controls. Furthermore, for GRN and FN1, we could detect a correlation of protein expression with the severity of the disease. CONCLUSION: Our findings suggest a potential use of GRN and FN1 as clinical biomarkers to detect endometriosis. In addition, GRN, NOTCH3, FN1, and PINK1 could potentially be useful to differentiate between the underlying stages of the disease. However, a validation with a larger study population is needed.

Treatment of Salmonella-Contaminated Eggs and Pork with a Broad-Spectrum, Single Bacteriophage: Assessment of Efficacy and Resistance Development.

Numerous studies have assessed the efficacy of phage-based methods to inhibit Salmonella contamination in food products. As with most antibacterials, bacteria can develop resistance to phage in vitro. Here, we applied a single broad-spectrum Salmonella phage, vB_SalS_SJ_2 (SJ2; 108 PFU; MOI = 10), to Salmonella-contaminated meat and eggs to quantify the development of resistance in actual food matrices. Treatment with a single phage significantly reduced Salmonella Typhimurium contamination in both ground pork and liquid egg at various time points. Similarly, the same phage significantly reduced Salmonella Enteritidis in both food matrices. Efficacy was temperature dependent as larger reductions were seen at higher temperatures (21°C) versus lower temperatures (4°C) at 24 h. Following phage treatment, over 10,000 Salmonella isolates were examined for resistance to the treatment phage. The percentages of phage-resistant Salmonella (either serovar) recovered from phage-treated versus untreated pork did not differ. Conversely, significantly (p < 0.05) higher percentages of phage-resistant Salmonella Typhimurium (92.50% vs. 0.56% of control) and Salmonella Enteritidis (50.83% vs. 0.56% of control) isolates were observed in phage-treated versus untreated egg samples after incubation at room temperature for 48 h. Taken together, these data indicate that the food matrix may influence the emergence of phage resistance with resistance developing more rapidly in foods with less complex microbial communities. Future studies will focus on the impact the development of resistance in production and processing settings may have on the efficacy of phage treatments for longer term biocontrol of pathogens.

Synthesis and structure-activity relationships of 8-(pyrid-3-yl)pyrazolo[1,5-a]-1,3,5-triazines: potent, orally bioavailable corticotropin releasing factor receptor-1 (CRF1) antagonists.

This report describes the syntheses and structure-activity relationships of 8-(substituted pyridyl)pyrazolo[1,5-a]-1,3,5-triazine corticotropin releasing factor receptor-1 (CRF(1)) receptor antagonists. These CRF(1) receptor antagonists may be potential anxiolytic or antidepressant drugs. This research resulted in the discovery of compound 13-15, which is a potent, selective CRF(1) antagonist (hCRF(1) IC(50) = 6.1 +/- 0.6 nM) with weak affinity for the CRF-binding protein and biogenic amine receptors. This compound also has a good pharmacokinetic profile in dogs. Analogue 13-15 is orally effective in two rat models of anxiety: the defensive withdrawal (situational anxiety) model and the elevated plus maze test. Analogue 13-15 has been advanced to clinical trials.

8-(4-Methoxyphenyl)pyrazolo[1,5-a]-1,3,5-triazines: selective and centrally active corticotropin-releasing factor receptor-1 (CRF1) antagonists.

This report describes the syntheses and structure-activity relationships of 8-(4-methoxyphenyl)pyrazolo[1,5-a]-1,3,5-triazine corticotropin releasing factor receptor-1 (CRF(1)) receptor antagonists. CRF(1) receptor antagonists may be potential anxiolytic or antidepressant drugs. This research culminated in the discovery of analogue 12-3, which is a potent, selective CRF(1) antagonist (hCRF(1) IC(50) = 4.7 +/- 2.0 nM) with weak affinity for the CRF-binding protein and biogenic amine receptors. This compound also has a good pharmacokinetic profile in dogs. Analogue 12-3 is orally effective in two rat models of anxiety: the defensive withdrawal (situational anxiety) model and the elevated plus maze test. Analogue 12-3 has been advanced to clinical trials.