Effect of potassium channel opener pinacidil on the contractions elicited electrically or by noradrenaline in the human radial artery

In order to discover an agent that can prevent spasm of the human radial artery, the aim of our study was to evaluate the effect of the K⁺ channel opener, pinacidil, on contractions in the radial artery. Contractions of the radial artery were evoked by exogenously applied noradrenaline or by electrical field stimulation (EFS, 20 Hz, neurogenic). Pinacidil induced concentration-dependent inhibition of both EFS- and noradrenaline-evoked contractions of the radial artery. Glibenclamide, a selective blocker of ATP-sensitive K⁺ channels (Kir6.x containing subunit) antagonized in the same manner the pinacidil-induced inhibition of neurogenic contractions and contractions evoked by exogenous noradrenaline. The inhibition of pinacidil relaxation by tetraethylammonium (TEA), a blocker of Ca-sensitive K⁺ (K_Ca) channels, was more pronounced in EFS-contracted preparations. A blocker of voltage-sensitive K⁺ (K_V) channels, 4-aminopyridine (4-AP), inhibited pinacidil relaxation only in EFS-contracted preparations. In order to test the presence of different K⁺ channels, immunohistochemistry of K⁺ channels expression in the radial artery was performed. The vascular wall of the human radial artery showed variable positivity with the following applied antibodies: Kv1.2, Kv1.3, Kir6.1, and K_Ca1.1. The antibodies against Kv1.6, Kv2.1, and Kir6.2 channel subunits were completely negative. These results suggest that the inhibitory effect of pinacidil on contractions of the human radial artery might be postsynaptic and associated with opening of smooth muscle Kir6.1-containing K_ATP channels. TEA- and 4-AP-sensitive K⁺ channels may also contribute to pinacidil effect in the human radial artery.     

Implementation and Evaluation of the SAEM Algorithm for Longitudinal Ordered Categorical Data with an Illustration in Pharmacokinetics–Pharmacodynamics

Analysis of longitudinal ordered categorical efficacy or safety data in clinical trials using mixed models is increasingly performed. However, algorithms available for maximum likelihood estimation using an approximation of the likelihood integral, including LAPLACE approach, may give rise to biased parameter estimates. The SAEM algorithm is an efficient and powerful tool in the analysis of continuous/count mixed models. The aim of this study was to implement and investigate the performance of the SAEM algorithm for longitudinal categorical data. The SAEM algorithm is extended for parameter estimation in ordered categorical mixed models together with an estimation of the Fisher information matrix and the likelihood. We used Monte Carlo simulations using previously published scenarios evaluated with NONMEM. Accuracy and precision in parameter estimation and standard error estimates were assessed in terms of relative bias and root mean square error. This algorithm was illustrated on the simultaneous analysis of pharmacokinetic and discretized efficacy data obtained after a single dose of warfarin in healthy volunteers. The new SAEM algorithm is implemented in MONOLIX 3.1 for discrete mixed models. The analyses show that for parameter estimation, the relative bias is low for both fixed effects and variance components in all models studied. Estimated and empirical standard errors are similar. The warfarin example illustrates how simple and rapid it is to analyze simultaneously continuous and discrete data with MONOLIX 3.1. The SAEM algorithm is extended for analysis of longitudinal categorical data. It provides accurate estimates parameters and standard errors. The estimation is fast and stable.     

The NLRP3 inflammasome,a target for therapy in diverse disease states

A role for NLRP3 inflammasome in recurrent and chronic inflammation was initially described in a group of rare autoinflammatory conditions, termed cryopyrin‐associated periodic syndrome. Subsequently, inflammasomes have been implicated in the pathology of many common diseases, including cancer, gout and diabetes. Despite diverse pathologies, the central role of the inflammasome in innate defences and tumour elimination suggests common therapeutic approaches to reduce inflammation where appropriate.     

Intrinsic network connectivity and own body perception in gender dysphoria

Gender dysphoria (GD) is characterized by incongruence between one’s identity and gender assigned at birth. The biological mechanisms of GD are unclear. We investigated brain network connectivity patterns involved in own body perception in the context of self in GD. Twenty-seven female-to-male (FtM) individuals with GD, 27 male controls, and 27 female controls underwent resting state fMRI. We compared functional connections within intrinsic connectivity networks involved in self-referential processes and own body perception –default mode network (DMN) and salience network – and visual networks, using independent components analyses. Behavioral correlates of network connectivity were also tested using self-perception ratings while viewing own body images morphed to their sex assigned at birth, and to the sex of their gender identity. FtM exhibited decreased connectivity of anterior and posterior cingulate and precuneus within the DMN compared with controls. In FtM, higher “self” ratings for bodies morphed towards the sex of their gender identity were associated with greater connectivity of the anterior cingulate within the DMN, during long viewing times. In controls, higher ratings for bodies morphed towards their gender assigned at birth were associated with right insula connectivity within the salience network, during short viewing times. Within visual networks FtM showed weaker connectivity in occipital and temporal regions. Results suggest disconnectivity within networks involved in own body perception in the context of self in GD. Moreover, perception of bodies in relation to self may be reflective rather than reflexive, as a function of mesial prefrontal processes. These may represent neurobiological correlates to the subjective disconnection between perception of body and self-identification.     

Craniocerebral injuries in traffic accidents with fatal outcomes

Research into crainiocerebral injury (CCI) characteristics of traffic accidents with fatal outcomes, as well as certain types of CCIs and defined categories of traffic participants, has been conducted. The research data were obtained from autopsy protocols at the Institute of Forensic Medicine in Serbia. Out of the 202 cases of individuals who had been fatally injured in traffic accidents, CCIs were diagnosed in 82.7% of them. The highest percentage of CCIs was established for front-seat passengers (95%), while for drivers it was 86.2%, pedestrians 78%, and 76% for rear-seat passengers. The domination of males among the deceased was also found, mostly as drivers (92%). The majority of individuals who experienced a CCI were in the age group of 21 to 30 years old, while pedestrians were commonly older than 60. In these cases, a high frequency of skull fractures was usually localized in different cranial regions (67.7%). In the majority of cases with CCIs (81.4%), these injuries contributed to an ultimate fatal outcome, mainly in pedestrians (93%). Fatal and non-fatal CCIs resulting from traffic accidents can result in significant socio-economic consequences for the individual and society as a whole that include specifically the ongoing costs and outcomes in cases from non-fatal injuries.