New approaches in pharmacology: numerical modelling and simulation

The complexity of pathophysiological mechanisms is beyond the capabilities of traditional approaches. Many of the decision-making problems in public health, such as initiating mass screening, are complex. Progress in genomics and proteomics, and the resulting extraordinary increase in knowledge with regard to interactions between gene expression, the environment and behaviour, the customisation of risk factors and the need to combine therapies that individually have minimal though well documented efficacy, has led doctors to raise new questions: how to optimise choice and the application of therapeutic strategies at the individual rather than the group level, while taking into account all the available evidence? This is essentially a problem of complexity with dimensions similar to the previous ones: multiple parameters with nonlinear relationships between them, varying time scales that cannot be ignored etc. Numerical modelling and simulation (in silico investigations) have the potential to meet these challenges. Such approaches are considered in drug innovation and development. They require a multidisciplinary approach, and this will involve modification of the way research in pharmacology is conducted.     

The effect of atorvastatin therapy on lecithin:cholesterol acyltransferase, cholesteryl ester transfer protein and the antioxidant paraoxonase

OBJECTIVES: The aim of our study was to examine the influence of atorvastatin on lipid parameters, particularly on HDL, and on the activity of LCAT and CETP and how they affect the activity of the HDL-associated antioxidant enzyme paraoxonase. DESIGN AND METHODS: Thirty-three patients with types II.a and II.b primary hyperlipoproteinemia were enrolled into our study. The patients received atorvastatin, 20 mg daily, for 3 months. We measured the serum paraoxonase activity and concentration, oxidized LDL, LCAT and CETP activities. RESULTS: Atorvastatin significantly reduced the levels of cholesterol, triglyceride, LDL-C and apoB, while it did not influence the levels of HDL-C and apo A-I. The increases in serum PON-specific activity, PON/HDL ratio and LCAT activity were significant, while oxLDL and CETP activities were significantly decreased. CONCLUSION: Atorvastatin may influence the composition and function of HDL, thereby possibly increasing the activity of paraoxonase and preventing atherosclerosis.     

Thrombotic and hemorrhagic complications during visceral transplantation: risk factors,and association with intraoperative disseminated intravascular coagulation‐like thromboelastographic qualities: a single‐center retrospective study

This study describes the risk of thrombotic and hemorrhagic complications, both intraoperatively, and up to 1 month following visceral transplantation. Data from 48 adult visceral transplants performed between 2010 and 2017 were retrospectively studied [32 multivisceral (MVTx); 10 isolated intestine; six modified‐MVTx]. Intraoperatively, intracardiac thrombosis (ICT)/pulmonary embolism (PE) occurred in 25%, 0% and 0% of MVTx, isolated intestine and modified MVTx, respectively, and was associated with 50% (4/8) mortality. Preoperative portal vein thrombosis (PVT) was a significant risk factor for ICT/PE (P = 0.0073). Thromboelastography resembling disseminated intravascular coagulation (DIC) (r time <4 mm combined with fibrinolysis or flat‐line) was statistically associated with occurrence of ICT/PE (P < 0.0001). Compared to subgroup without ICT/PE, occurrence of ICT/PE was associated with an increased demand for all blood product components both overall, and each surgical stage. Hyperfibrinolysis (56%) was identified as cause of bleeding in MVTx. Incidence of postoperative thrombotic event at 1 month was 25%, 30% and 17% for MVTx, isolated intestine and modified MVTx, respectively. Incidence of postoperative bleeding complications at 1 month was 11%, 20% and 17% for MVTx, isolated intestine and modified MVTx. In conclusion, MVTx recipients with preoperative PVT are at an increased risk of developing intraoperative life‐threatening ICT/PE events associated with DIC‐like coagulopathy.     

Among adolescents,addiction susceptibility and sleep-related dysfunction have a common cognitive-emotional base and predict poor sleep quantity

Background: Among adolescents, the self-pacing of sleep and experimentation with psychotropic substances increases. Poor sleep and susceptibility to addiction (SA) may therefore share common cognitive-emotional processes. The aim of the present study was to investigate the shared cognitive-emotional basis of SA and sleep-related dysfunction, and to explore their predictive value for sleep patterns.

Methods: A total of 300 adolescents (mean age: 15.57 years; 50% females) took part in this questionnaire-based study. Participants completed a booklet covering sociodemographic, sleep-related (Sleep Hygiene Index: SHI; Pittsburgh Sleep Quality Index: PSQI) and SA-related variables.

Results: Greater sleep-related dysfunction based on the SHI was strongly associated with higher SA scores. Parents’ educational level was negatively associated with SHI and SA scores. An exploratory factor analysis of SHI and SA items yielded three distinct factors: (i) risky behavior and irregular sleep-wake schedules, (ii) poor sleep environment and hygiene, and (iii) psychological arousal and distress. All three factors independently contributed to the prediction of poor sleep quality and quantity.

Conclusions: Adolescents reporting dysfunctional cognitive-emotional processes are at increased risk of reporting poor sleep patterns. Additionally, poor sleep and SA were related to parents’ education, suggesting that both parents and their children might benefit from sleep hygiene counseling.     

Cardiac contractility modulation: mechanisms of action in heart failure with reduced ejection fraction and beyond

Heart failure (HF) is responsible for substantial morbidity and mortality and is increasing in prevalence. Although there has been remarkable progress in the treatment of HF with reduced ejection fraction (HFrEF), morbidity and mortality are still substantial. Cardiac contractility modulation (CCM) signals, consisting of biphasic high‐voltage bipolar signals delivered to the right ventricular septum during the absolute refractory period, have been shown to improve symptoms, exercise tolerance and quality of life and reduce the rate of HF hospitalizations in patients with ejection fractions (EF) between 25% and 45%. CCM therapy is currently approved in the European Union, China, India, Australia and Brazil for use in symptomatic HFrEF patients with normal or slightly prolonged QRS duration. CCM is particularly beneficial in patients with baseline EF between 35% and 45%, which includes half the range of HF patients with mid‐range EFs (HFmrEF). At the cellular level, CCM has been shown in HFrEF patients to improve calcium handling, to reverse the foetal myocyte gene programme associated with HF, and to facilitate reverse remodelling. This review highlights the preclinical and clinical literature related to CCM in HFrEF and HFmrEF and outlines the potential of CCM for HF with preserved EF, concluding that CCM may fill an important unmet need in the therapeutic approach to HF across the range of EFs.     

Recruitment of platelets, white blood cells, and hematopoietic progenitor cells during high-yield plateletpheresis

BACKGROUND: Previous observations suggested recruitment of platelets (PLTs) and white blood cells (WBCs) during plateletpheresis and recruitment of hematopoietic progenitor cells (HPCs) by HPC apheresis. Quantification of recruitment helps to optimize yields and safety of these procedures; detection of WBC or HPC recruitment during plateletpheresis may further elucidate the mechanisms. STUDY DESIGN AND METHODS: This study was a prospective cohort study with 68 single‐needle plateletpheresis donations (23 double, PLT yield ≥4.8 × 10¹¹; 23 triple, ≥7.2 × 10¹¹; 22 quadruple, ≥9.6 × 10¹¹). We measured PLTs, WBCs, WBC subpopulations, and circulating HPCs (CD34 mRNA) before, during, and after apheresis; calculated PLT recruitment and ratio of recruited to yielded PLT; and propose a novel concept to optimize the prediction of the PLT counts after apheresis (PLT_post). RESULTS: PLT recruitment (mean ± SD, 1.56 ± 0.31) caused a higher PLT_post than predicted by the instrument (164 × 10⁹ ± 23 × 10⁹ vs. 111 × 10⁹ ± 31 × 10⁹/L; p < 0.0001) in all three groups. The ratio of recruited to yielded PLT was 0.36 ± 0.15. The WBC count decreased by 9% to the time before rinse‐back and returned to the baseline thereafter. No changes in circulating HPCs occurred. CONCLUSIONS: PLT recruitment during high‐yield plateletpheresis facilitates the harvest of multiple PLT units in a single donation. The use of the ratio of recruited to yielded PLT may optimize the algorithm to predict PLT_post. There was no recruitment of WBCs and HPCs during plateletpheresis. Therefore, the previously observed recruitment of HPCs during HPC apheresis seems to be related to other factors than the apheresis procedure itself.     

Platelet Recruitment during Multiple Donor Platelet Apheresis Differs between Cell Separators

SUMMARY: BACKGROUND: Recruitment of platelets (PLT) during donor PLT apheresis may facilitate the harvest of multiple units within a single donation. METHODS: We compared two PLT apheresis procedures (Amicus and Trima Accel) in a prospective, randomized, paired cross-over study in 60 donors. The 120 donations were compared for depletion of circulating PLT in the donors, PLT yields and PLT recruitment. A recruitment was defined as ratio of total PLT yield and donor PLT depletion > 1. RESULTS: Despite comparable differences of pre- and post-apheresis PLT counts (87 × 10(9)/l in Trima Accel vs. 92 × 10(9)/l in Amicus, p = 0.383), PLT yields were higher with Trima Accel (7.48 × 10(11) vs. 6.06 × 10(11), p < 0.001), corresponding to a higher PLT recruitment (1.90 vs. 1.42, p < 0.001). We observed a different increase of WBC counts after aphereses, which was more pronounced with Trima Accel than with Amicus (1.30 × 10(9)/l vs. 0.46 × 10(9)/l, p < 0.001). CONCLUSION: Both procedures induced PLT recruitment. This was higher in Trima Accel, contributing to a higher yield in spite of a comparable depletion of circulating PLT in the donors. This recruitment facilitates the harvest of multiple units within a single donation and seems to be influenced by the procedure utilized. The different increases of circulating donor white blood cells after donation need further investigation.     

Shock priming enhances the efficacy of SSRIs in the foot shock-induced ultrasonic vocalization test

Data on the effect of acutely administered serotonin reuptake inhibitors (SSRIs) in animal anxiety models have been inconsistent. In some of the models these compounds showed anxiolytic properties, while in others they were ineffective or even anxiogenic. In the foot shock-induced ultrasonic vocalization (USV) test in the adult rat, SSRIs were reported to be effective, however, they were only tested with protocols using multiple shocking design. In the present study, anxiolytic effects of various SSRI compounds (sertraline, fluoxetine, paroxetine, escitalopram) were tested in three distinct USV test protocols in comparison with alprazolam and 8-OH-DPAT. In the single shocking protocol, animals were exposed to one shocking session after the drug treatment. In the multiple shocking protocol, rats went through a foot shock priming session before each drug test. On priming days animals received foot shocks without drug treatment. On the test day (the day after), rats received drug treatment and then were shocked again. In the context conditioning protocol animals were exposed to foot shocks on two consecutive days before the drug test. On the third, test day, after drug treatment animals were replaced to the shocking chamber, but this time shocks were not delivered. SSRIs were ineffective using the single shocking protocol. In the context conditioned protocol, all SSRIs showed linear dose-response relationship with ED₅₀ values of 8.5, 2.2, 0.77 and 0.93 mg/kg i.p. for fluoxetine, sertraline, paroxetine and escitalopram, respectively. Using the multiple shocking protocol, SSRIs were only partially effective with maximum inhibitions ranging between 44% and 62%. In contrast to SSRIs, the benzodiazepine anxiolytics, alprazolam showed anxiolytic activity with linear dose-response relationship in all of the test protocols, with ED₅₀ values varying from 1.3 to 4.0 mg/kg i.p. The serotonin 5HT_1A receptor antagonist 8-OH-DPAT also showed linear dose-response relationship in all protocols, but this compound was less potent in the single shocking design (ED₅₀ values were 0.27, 0.04 and 0.07 mg/kg i.p. in the single shocking, multiple shocking and context conditioned protocol, respectively). In conclusion, our results show that priming has a major impact on the effectiveness of SSRIs in the USV test, and the three test protocols applied in this study have different predictive and face validity.     

Long-term ethanol consumption initiates atherosclerosis in rat aorta through inflammatory stress and endothelial dysfunction

Controversy exists on whether alcohol has a direct cardioprotective effect or it provokes atherosclerosis, so the present study sought to assess the effect of chronic consumption of ethanol on the markers of endothelial function, vessel rigidity, and atherosclerosis in the aorta of rat. Male Wistar rats were selected randomly and exposed to ethanol (4.5g?kg of 20% w/v solution in saline) once per day for 6weeks. Blood pressure, hemodynamic parameters, foam cell formation, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, endothelial-leukocyte adhesion molecule-1, and high-sensitivity C-reactive protein (CRP) were assessed in ethanol treated rats and compared with either sham or control rats. The results revealed a concurrent significant increase of adhesion molecules, CRP levels, systolic, diastolic, pulse, and dicrotic pressures as well as enhanced formation of foam cell in ethanol-treated rats. These findings implicate that long-term ethanol exposure provokes atherogenic and hemodynamic changes via significant induction of proinflammatory response, augmenting of cell adhesion molecules, stiffness in rat aorta wall and induction of foam cell formation.