Analgesic efficacy of CR4056, a novel imidazoline-2 receptor ligand, in rat models of inflammatory and neuropathic pain

Two decades of investigations have failed to unequivocally clarify the functions and the molecular nature of imidazoline-2 receptors (I2R). However, there is robust pharmacological evidence for the functional modulation of monoamino oxidase (MAO) and other important enzyme activities by I2 site ligands. Some compounds of this class proved to be active experimental tools in preventing both experimental pain and opioid tolerance and dependence. Unfortunately, even though these compounds bind with high potency to central I2 sites, they fail to represent a valid clinical opportunity due to their pharmacokinetic, selectivity or side-effects profile. This paper presents the preclinical profile of a novel I2 ligand (2-phenyl-6-(1H-imidazol-1yl) quinazoline; [CR4056]) that selectively inhibits the activity of human recombinant MAO-A in a concentration-dependent manner. A sub-chronic four day oral treatment of CR4056 increased norepinephrine (NE) tissue levels both in the rat cerebral cortex (63.1% ±4.2%; P < 0.05) and lumbar spinal cord (51.3% ± 6.7%; P < 0.05). In the complete Freund’s adjuvant (CFA) rat model of inflammatory pain, CR4056 was found to be orally active (ED50 = 5.8 mg/kg, by mouth [p.o.]). In the acute capsaicin model, CR4056 completely blocked mechanical hyperalgesia in the injured hind paw (ED50 = 4.1 mg/kg, p.o.; ED100 = 17.9 mg/kg, p.o.). This effect was dose-dependently antagonized by the non-selective imidazoline I2/α2 antagonist idazoxan. In rat models of neuropathic pain, oral administration of CR4056 significantly attenuated mechanical hyperalgesia and allodynia. In summary, the present study suggests a novel pharmacological opportunity for inflammatory and/or neuropathic pain treatment based on selective interaction with central imidazoline-2 receptors

Lopinavir/Ritonavir and Darunavir/Cobicistat in Hospitalized COVID-19 Patients: Findings From the Multicenter Italian CORIST Study

Background: Protease inhibitors have been considered as possible therapeutic agents for COVID-19 patients. Objectives: To describe the association between lopinavir/ritonavir (LPV/r) or darunavir/cobicistat (DRV/c) use and in-hospital mortality in COVID-19 patients. Study Design: Multicenter observational study of COVID-19 patients admitted in 33 Italian hospitals. Medications, preexisting conditions, clinical measures, and outcomes were extracted from medical records. Patients were retrospectively divided in three groups, according to use of LPV/r, DRV/c or none of them. Primary outcome in a time-to event analysis was death. We used Cox proportional-hazards models with inverse probability of treatment weighting by multinomial propensity scores. Results: Out of 3,451 patients, 33.3% LPV/r and 13.9% received DRV/c. Patients receiving LPV/r or DRV/c were more likely younger, men, had higher C-reactive protein levels while less likely had hypertension, cardiovascular, pulmonary or kidney disease. After adjustment for propensity scores, LPV/r use was not associated with mortality (HR = 0.94, 95% CI 0.78 to 1.13), whereas treatment with DRV/c was associated with a higher death risk (HR = 1.89, 1.53 to 2.34, E-value = 2.43). This increased risk was more marked in women, in elderly, in patients with higher severity of COVID-19 and in patients receiving other COVID-19 drugs. Conclusions: In a large cohort of Italian patients hospitalized for COVID-19 in a real-life setting, the use of LPV/r treatment did not change death rate, while DRV/c was associated with increased mortality. Within the limits of an observational study, these data do not support the use of LPV/r or DRV/c in COVID-19 patients

Fatality rate and predictors of mortality in an Italian cohort of hospitalized COVID-19 patients

Clinical features and natural history of coronavirus disease 2019 (COVID-19) differ widely among different countries and during different phases of the pandemia. Here, we aimed to evaluate the case fatality rate (CFR) and to identify predictors of mortality in a cohort of COVID-19 patients admitted to three hospitals of Northern Italy between March 1 and April 28, 2020. All these patients had a confirmed diagnosis of SARS-CoV-2 infection by molecular methods. During the study period 504/1697 patients died; thus, overall CFR was 29.7%. We looked for predictors of mortality in a subgroup of 486 patients (239 males, 59%; median age 71 years) for whom sufficient clinical data were available at data cut-off. Among the demographic and clinical variables considered, age, a diagnosis of cancer, obesity and current smoking independently predicted mortality. When laboratory data were added to the model in a further subgroup of patients, age, the diagnosis of cancer, and the baseline PaO2/FiO2 ratio were identified as independent predictors of mortality. In conclusion, the CFR of hospitalized patients in Northern Italy during the ascending phase of the COVID-19 pandemic approached 30%. The identification of mortality predictors might contribute to better stratification of individual patient risk

Sleep disorders in Sanfilippo syndrome: a polygraphic study

Objective: A high prevalence of sleep disorders is reported in patients affected by Mucopolysaccharidosis III (Sanfilippo syndrome). These disorders have never been investigated by prolonged, objective, and instrumental evaluations. The present work is based on sleep duration and structure in Sanfilippo patients. Study design: The features of sleep/wake cycle in 6 Sanfilippo patients and 6 healthy controls were evaluated by means of sleep diaries and 48 hour ambulatory EEG and polygraphic recordings. Statistical analysis was performed by means of the U-test (Mann-Whitney). Results: Four out of six Sanfilippo patients, the oldest patients in our sample, showed an extremely irregular sleep pattern, with several sleep episodes of inconstant duration, irregularly distributed along 24 hours. The two younger patients showed sleep maintenance insomnia with several nocturnal awakenings. Conclusions: These results suggest that sleep disruption in Sanfilippo syndrome consists of an irregular sleep/wake pattern, which at its onset might appear as a disorder of initiating or maintaining sleep. This could explain why some patients do not respond to conventional hypnotics. The present observation might suggest attempting therapies aimed at resynchronization, such as behavioral treatment, light therapy or melatonin. </jats:sec

Optimization of Aminoimidazole Derivatives as Src Family Kinase Inhibitors

Protein kinases have emerged as crucial targets for cancer therapy over the last decades. Since 2001, 40 and 39 kinase inhibitors have been approved by FDA and EMA, respectively, and the majority are antineoplastic drugs. Morevoer, many candidates are currently in clinical trials. We previously reported a small library of 4-aminoimidazole and 2-aminothiazole derivatives active as Src family kinase (SFK) inhibitors. Starting from these results, we decided to perform an optimization study applying a mix and match strategy to identify a more potent generation of 4-aminoimidazoles. Firstly, a computational study has been performed, then compounds showing the best predicted docking scores were synthesized and screened in a cell-free assay for their SFK inhibitory activity. All the new chemical entities showed IC50s in the nanomolar range, with 2&ndash;130 fold increased activities compared to the previously reported inhibitors. Finally, the most active compounds have been tested on three cancer cell lines characterized by Src hyperactivation. Compounds 4k and 4l showed an interesting antiproliferative activity on SH-SY5Y neuroblastoma (NB) cell line. In this assay, the compounds resulted more potent than dasatinib, a tyrosine kinase inhibitor approved for the treatment of leukemias and in clinical trials for NB

MORPHINE TOLERANCE MODULATION INDUCED BY alpha2-ADRENERGIC OR/AND I2 IMIDAZOLINE BINDING SITES LIGANDS

The chronic use of opioids is often accompanied by development of tolerance, described as the need for increasing drug dosage to achieve the same effect. Previous studies demonstrated that both alpha2-adrenergic receptors (alpha2-AR) or I2 Imidazoline Binding Sites (I2-IBS) are involved in the modulation of morphine analgesia as well as tolerance and dependence. Our studies demonstrated that in molecular structures, sharing the common pharmacophore reported in figure 1, the bridge X determined the preferential recognition of a specific biological system. In particular, the -OCH(CH3)- bridge of 1 was suitable for alpha2-AR interaction, whereas the -CH2CH2- bridge (2) proved to be effective for I2-IBS. Interestingly, the -OCH2- bridge (3) was compatible with both systems. To assess the effects on tolerance to morphine, 1-3 were administered once daily for 4 days at a dose of 0.5 mg/Kg i.p. 15’ before the morphine s.c. After 4 days morphine was completely inactive. In contrast, 1-3, even though with different behaviour, significantly inibited morphine tolerance. In fact, 2 restored the lost morphine analgesic response in “neutral” mode, whereas 1 and 3 produced a temporal variation of morphine analgesic response extending its efficacy

Dendrimeric tetravalent ligands for the serotonin-gated ion channel

Multivalency is widely used in nature in specific recognition processes. This paper describes an approach to multivalency in the pentameric 5-HT 3 receptor, a ligand-gated ion channel, which constitutes an example of intrinsically multivalent biological receptors. Owing to the picomolar K i value, TETRA-L represents an outstanding multivalent ligand for the neurotransmitter receptor