Long-lasting Manner Research Articles

Enzyme-MOF Nanoreactor Activates Nontoxic Paracetamol for Cancer Therapy.

Prodrug activation, by exogenously administered enzymes, for cancer therapy is an approach to achieve better selectivity and less systemic toxicity than conventional chemotherapy. However, the short half-lives of the activating enzymes in the bloodstream has limited its success. Demonstrated here is that a tyrosinase-MOF nanoreactor activates the prodrug paracetamol in cancer cells in a long-lasting manner. By generating reactive oxygen species (ROS) and depleting glutathione (GSH), the product of the enzymatic conversion of paracetamol is toxic to drug-resistant cancer cells. Tyrosinase-MOF nanoreactors cause significant cell death in the presence of paracetamol for up to three days after being internalized by cells, while free enzymes totally lose activity in a few hours. Thus, enzyme-MOF nanocomposites are envisioned to be novel persistent platforms for various biomedical applications.

Synaptic consolidation as a temporally variable process: Uncovering the parameters modulating its time-course.

Memories are not instantly created in the brain, requiring a gradual stabilization process called consolidation to be stored and persist in a long-lasting manner. However, little is known whether this time-dependent process is dynamic or static, and the factors that might modulate it. Here, we hypothesized that the time-course of consolidation could be affected by specific learning parameters, changing the time window where memory is susceptible to retroactive interference. In the rodent contextual fear conditioning paradigm, we compared weak and strong training protocols and found that in the latter memory is susceptible to post-training hippocampal inactivation for a shorter period of time. The accelerated consolidation process triggered by the strong training was mediated by glucocorticoids, since this effect was blocked by pre-training administration of metyrapone. In addition, we found that pre-exposure to the training context also accelerates fear memory consolidation. Hence, our results demonstrate that the time window in which memory is susceptible to post-training interferences varies depending on fear conditioning intensity and contextual familiarity. We propose that the time-course of memory consolidation is dynamic, being directly affected by attributes of the learning experiences.

Acute and chronic modulation of striatal endocannabinoid-mediated plasticity by nicotine.

The endocannabinoid (eCB) system modulates several phenomena related to addictive behaviors, and drug‐induced changes in eCB signaling have been postulated to be important mediators of physiological and pathological reward‐related synaptic plasticity. Here, we studied eCB‐mediated long‐term depression (eCB‐LTD) in the dorsolateral striatum, a brain region critical for acquisition of habitual and automatic behavior. We report that nicotine differentially affects ex vivo eCB signaling depending on previous exposure in vivo. In the nicotine‐naïve brain, nicotine facilitates eCB‐signaling and LTD, whereas tolerance develops to this facilitating effect after subchronic exposure in vivo. In the end, a progressive impairment of eCB‐induced LTD is established after protracted withdrawal from nicotine. Endocannabinoid‐LTD is reinstated 6 months after the last drug injection, but a brief period of nicotine re‐exposure is sufficient to yet again impair eCB‐signaling. LTD induced by the cannabinoid 1 receptor agonist WIN55,212‐2 is not affected, suggesting that nicotine modulates eCB production or release. Nicotine‐induced facilitation of eCB‐LTD is occluded by the dopamine D2 receptor agonist quinpirole, and by the muscarinic acetylcholine receptor antagonist scopolamine. In addition, the same compounds restore eCB‐LTD during protracted withdrawal. Nicotine may thus modulate eCB‐signaling by affecting dopaminergic and cholinergic neurotransmission in a long‐lasting manner. Overall, the data presented here suggest that nicotine facilitates eCB‐LTD in the initial phase, which putatively could promote neurophysiological and behavioral adaptations to the drug. Protracted withdrawal, however, impairs eCB‐LTD, which may influence or affect the ability to maintain cessation.

Conserved Vδ1 Binding Geometry in a Setting of Locus-Disparate pHLA Recognition by δ/αβ T Cell Receptors (TCRs): Insight into Recognition of HIV Peptides by TCRs.

Given the limited set of T cell receptor (TCR) V genes that are used to create TCRs that are reactive to different ligands, such as major histocompatibility complex (MHC) class I, MHC class II, and MHC-like proteins (for example, MIC molecules and CD1 molecules), the Vδ1 segment can be rearranged with Dδ-Jδ-Cδ or Jα-Cα segments to form classical γδTCRs or uncommon αβTCRs using a Vδ1 segment (δ/αβTCR). Here we have determined two complex structures of the δ/αβTCRs (S19-2 and TU55) bound to different locus-disparate MHC class I molecules with HIV peptides (HLA-A*2402-Nef138-10 and HLA-B*3501-Pol448-9). The overall binding modes resemble those of classical αβTCRs but display a strong tilt binding geometry of the Vδ1 domain toward the HLA α1 helix, due to a conserved extensive interaction between the CDR1δ loop and the N-terminal region of the α1 helix (mainly in position 62). The aromatic amino acids of the CDR1δ loop exploit different conformations ("aromatic ladder" or "aromatic hairpin") to accommodate distinct MHC helical scaffolds. This tolerance helps to explain how a particular TCR V region can similarly dock onto multiple MHC molecules and thus may potentially explain the nature of TCR cross-reactivity. In addition, the length of the CDR3δ loop could affect the extent of tilt binding of the Vδ1 domain, and adaptively, the pairing Vβ domains adjust their mass centers to generate differential MHC contacts, hence probably ensuring TCR specificity for a certain peptide-MHC class I (pMHC-I). Our data have provided further structural insights into the TCR recognition of classical pMHC-I molecules, unifying cross-reactivity and specificity.IMPORTANCE The specificity of αβ T cell recognition is determined by the CDR loops of the αβTCR, and the general mode of binding of αβTCRs to pMHC has been established over the last decade. Due to the intrinsic genomic structure of the TCR α/δ chain locus, some Vδ segments can rearrange with the Cα segment, forming a hybrid VδCαVβCβ TCR, the δ/αβTCR. However, the basis for the molecular recognition of such TCRs of their ligands is elusive. Here an αβTCR using the Vδ1 segment, S19-2, was isolated from an HIV-infected patient in an HLA-A*24:02-restricted manner. We then solved the crystal structures of the S19-2 TCR and another δ/αβTCR, TU55, bound to their respective ligands, revealing a conserved Vδ1 binding feature. Further binding kinetics analysis revealed that the S19-2 and TU55 TCRs bind pHLA very tightly and in a long-lasting manner. Our results illustrate the mode of binding of a TCR using the Vδ1 segment to its ligand, virus-derived pHLA.

Threonine eliminylation by bacterial phosphothreonine lyases rapidly causes cross-linking of mitogen-activated protein kinase (MAPK) in live cells

Old long-lived proteins contain dehydroalanine (Dha) and dehydrobutyrine (Dhb), two amino acids engendered by dehydration of serines and threonines, respectively. Although these residues have a suspected role in protein cross-linking and aggregation, their direct implication has yet to be determined. Here, we have taken advantage of the ability of the enteropathogen Shigella to convert the phosphothreonine residue of the pT-X-pY consensus sequence of ERK and p38 into Dhb and followed the impact of dehydration on the fate of the two MAPKs. To that end, we have generated the first antibodies recognizing Dhb-modified proteins and allowing tracing them as they form. We showed that Dhb modifications accumulate in a long-lasting manner in Shigella-infected cells, causing subsequent formation of covalent cross-links of MAPKs. Moreover, the Dhb signal correlates precisely with the activation of the Shigella type III secretion apparatus, thus evidencing injectisome activity. This observation is the first to document a causal link between Dhb formation and protein cross-linking in live cells. Detection of eliminylation is a new avenue to phosphoproteome regulation in eukaryotes that will be instrumental for the development of type III secretion inhibitors.

Short- and Long-term Effects of Repetitive Transcranial Magnetic Stimulation on Upper Limb Motor Function after Stroke: a Systematic Review and Meta-Analysis

Objective: The aim of this study was to evaluate the short- and long-term effects as well as other parameters of repetitive transcranial magnetic stimulation (rTMS) on upper limb motor functional recovery after stroke. Data sources: The databases of PubMed, Medline, Science Direct, Cochrane, and Embase were searched for randomized controlled studies reporting effects of rTMS on upper limb motor recovery published before October 30, 2016. Review methods: The short- and long-term mean effect sizes as well as the effect size of rTMS frequency of pulse, post-stroke onset, and theta burst stimulation patterns were summarized by calculating the standardized mean difference (SMD) and the 95% confidence interval using fixed/random effect models as appropriate. Results: Thirty-four studies with 904 participants were included in this systematic review. Pooled estimates show that rTMS significantly improved short-term (SMD, 0.43; P < 0.001) and long-term (SMD, 0.49; P < 0.001) manual dexterity. More pronounced effects were found for rTMS administered in the acute phase of stroke (SMD, 0.69), subcortical stroke (SMD, 0.66), 5-session rTMS treatment (SMD, 0.67) and intermittent theta burst stimulation (SMD, 0.60). Only three studies reported mild adverse events such as headache and increased anxiety . Conclusions: Five-session rTMS treatment could best improve stroke-induced upper limb dyskinesia acutely and in a long-lasting manner. Intermittent theta burst stimulation is more beneficial than continuous theta burst stimulation. rTMS applied in the acute phase of stroke is more effective than rTMS applied in the chronic phase. Subcortical lesion benefit more from rTMS than other lesion site.

Therapeutic efficacy of novel microwave-sensitized mPEG-PLGA@ZrO2@(DOX + ILS) drug-loaded microspheres in rabbit VX2 liver tumours.

The use of nanomaterials as drug delivery systems shows good effects in treating tumors. However, the effective dose of drugs targeted to tumor tissues is very low because of the effect of the reticuloendothelial system (RES) in removing such foreign substances. In order to eliminate the RES effect, we developed mPEG-PLGA@ZrO2@(DOX + ILS) (mPEG-PLGA@ZrO2@[DOX + ILS]) drug-loaded microspheres. These microwave (MW)-sensitized microspheres directly embolized the blood-supply vessels of tumors to induce tumor ischemia and hypoxia, as well as to aggregate drugs within tumor tissues in a long-lasting manner. Additionally, combination with MW ablation can triple the effects for the inhibition of tumor growth. The MW sensitive ionic liquid (ILS) in microspheres can rapidly produce a high temperature in a MW field on the basis of MW sensitization, thus accelerating the degradation of microspheres to release DOX-loaded ZrO2 into the lesions to kill tumors. Microspheres can also prolong the pharmacological time and effect of drugs through the enhanced permeability and retention (EPR) effect of nanocarriers, as well as the sustained release of nanomaterials. Studies performed in vivo revealed that mPEG-PLGA@ZrO2@(DOX + ILS) showed good biosafety. We undertook sensitized microsphere embolism therapy using novel mPEG-PLGA@ZrO2@(DOX + ILS) microspheres in a rabbit VX2 liver tumor model. Three, 6 and 9 d after treatment, computed tomography indicated no significant change in tumor size, and diffusion weighted imaging showed a marked decrease of residual tumor tissues. With the multiple functions of inducing embolisms, sensitization, and the sustained release of chemotherapeutics, novel mPEG-PLGA@ZrO2@(DOX + ILS) microspheres can achieve good therapeutic efficacy, in combination with MW ablation and chemotherapy, while embolizing the blood vessels of arterial tumors.

Chalcone Derivatives Activate and Desensitize the Transient Receptor Potential Ankyrin 1 Cation Channel, Subfamily A, Member 1 TRPA1 Ion Channel: Structure-Activity Relationships in vitro and Anti-Nociceptive and Anti-inflammatory Activity in vivo.

Eleven compounds belonging to the chalcone family were tested for their ability to activate and subsequently desensitize the rat transient receptor potential ankyrin 1 cation channel, subfamily A, member 1 (TRPA1) in a heterologous expression system. Four of the tested compounds were more potent than the TRPA1 agonist mustard oil, and showed also a strong desensitizing effect. Some chalcone compounds were not pungent in the eye-wiping assay and quite remarkably inhibited in a long-lasting and dose-dependent manner the pain response in the formalin test. Chalcones can be considered as novel candidates for the development of antihyperalgesic preparations based on TRPA1 desensitization.

PKA-CREB-BDNF signaling regulated long lasting antidepressant activities of Yueju but not ketamine

Yueju confers antidepressant effects in a rapid and long-lasting manner, similar to ketamine. CREB (cAMP-response element binding protein) signaling is implicated in depression pathology and antidepressant responses. However, the role of CREB and associated brain derived neurotrophic factor (BDNF) signaling in rapid and long-lasting antidepressant effects remains unclear. Here, we demonstrated that ICR and Kunming strain mice conferred antidepressant responses lasting for 1 and 5 days, respectively, following a single dose of Yueju. One day post Yueju in Kunming but not ICR strain mice, expression of total and phosphorylated CREB, as well as the CREB signaling activator, PKA (protein kinase A) was up-regulated in the hippocampus. Although BDNF gene expression increased at 3 hours in both strains, it remained up-regulated at 1 day only in Kunming mice. Ketamine showed similar strain-dependent behavioral effects. However, blockade of PKA/CREB signaling blunted the antidepressant effects and reversed the up-regulation of BDNF gene expression by Yueju, but not ketamine. Conversely, blockade of mammalian target of rapamycin signaling led to opposite effects. Taken altogether, prolonged transcriptional up-regulation of hippocampal BDNF may account for the stain-dependent enduring antidepressant responses to Yueju and ketamine, but it was mediated via PKA/CREB pathway only for Yueju.

Commentary: Rewriting the Valuation and Salience of Alcohol-Related Stimuli via Memory Reconsolidation

Commentary: Rewriting the Valuation and Salience of Alcohol-Related Stimuli via Memory Reconsolidation

Effects of 1-cyclohexyl- and 1-cyclohexyl-N-propargyl-1,2,3,4-tetrahydroisoquinoline on dopaminergic spontaneous discharge in nigral neurons of rats.

1,2,3,4-Tetrahydroisoquinoline (TIQ) and some of its derivatives, such as 1-benzyl-TIQ and 1-methyl-TIQ, are endogenously present in human brain and are thought to contribute to induction or prevention of Parkinson's disease. In the present study, we estimated the effects of the artificially synthesized TIQ derivatives 1-cyclohexyl-TIQ (1-cHex-TIQ) and 1-cyclohexyl-N-propargyl-TIQ (1-cHex-N-proTIQ) on spontaneous nigral dopaminergic discharge in rats. Low to middle doses of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induced a transient and significant, but not relatively potent, increase in the firing rate, followed by a sustained decrease with higher doses. 1-cHex-TIQ increased the firing frequency at low and high doses. In contrast, 1-cHex-N-proTIQ had no effects on spontaneous firing. Although intraperitoneal pretreatment with 1-cHex-TIQ did not inhibit this MPTP-induced decrease in firing, pretreatment with 1-cHex-N-proTIQ significantly depressed this decreased firing in a dose-dependent and long-lasting manner. Selegiline, a monoamine oxidase type B inhibitor that is used as a therapeutic drug for Parkinson's disease, also significantly inhibited the decrease in dopaminergic spontaneous firing induced by MPTP, but the effect was transient. These results suggest that although the decrease in firing induced by 1-cHex-TIQ is clearly more potent compared to that induced by MPTP, its effect is eliminated by adding an N-propargyl functional group. The antagonizing effect of 1-cHex-N-proTIQ on MPTP-induced firing loss may be exerted by a different mechanism than that of selegiline.

Chronic Sleep Deprivation Exacerbates Learning-Memory Disability and Alzheimer's Disease-Like Pathologies in AβPP(swe)/PS1(ΔE9) Mice.

Recently, there is an increasing concern over the association between sleep disorders and Alzheimer's disease (AD). Clinical observations have reported that chronic sleep deprivation (SD) may serve as a risk factor for AD. However, the pathological evidence for this assumption is still lacking. In the present study, we examined the potential impacts of chronic SD on learning-memory and AD-related pathologies in AβPP(swe)/PS1(ΔE9) transgenic (TG) mice and their wild-type (WT) littermates. Results indicated that mice (both TG and WT) exposed to 2-month SD showed an altered amyloid-β protein precursor processing, an elevated level of phosphorylated tau protein, and impaired cognitive performance as compared to non-sleep deprivation (NSD) controls. Moreover, the SD-treated TG mice exhibited more amyloid-β(1-42) production and developed more senile plaques in the cortex and hippocampus than NSD-treated TG mice. In addition, SD caused a striking neuronal mitochondrial damage, caspase cascade activation, and neuronal apoptosis in the hippocampus of both TG and WT mice. More importantly, all these behavioral, neuropathological, and biochemical changes induced by chronic SD were long lasting and were irreversible during a 3-month normal housing condition. Collectively, these results indicate that chronic SD impairs learning and memory, exacerbates AD pathologies, and aggravates the mitochondria-mediated neuronal apoptosis in a long-lasting manner. Our findings provide important experimental evidence to prove that chronic SD is a risk factor for AD.

"Moderate Stress Enhances Immediate and Delayed Retrieval of Educationally Relevant Material in Healthy Young Men": Correction to Hupbach and Fieman (2012).

Reports an error in "Moderate stress enhances immediate and delayed retrieval of educationally relevant material in healthy young men" by Almut Hupbach and Rachel Fieman (Behavioral Neuroscience, 2012[Dec], Vol 126[6], 819-825). In the article there are computational errors in the last sentence of the Memory Performance section. "(M = .30, SD = .11 for CPS, and M = .13, SD = 17 for the warm water control)." should read instead: "(M = .03, SD = .11 for CPS, and M = .13, SD = .17 for the warm water control)." (The following abstract of the original article appeared in record 2012-27908-001.) Retrieval practice is a powerful memory enhancer. However, in educational settings, test taking is often experienced as a stressful event. While it is known that stress can impair retrieval processes, little is known about the delayed consequences of testing memory for educationally relevant material under stressful conditions, which is the focus of the present study. Participants (38 women, 37 men) memorized a scientific text passage on Day 1. On Day 2, they were either exposed to a stressor (cold pressor test; CPS) or a warm water control, and immediately afterward, they were asked to recall the text passage (i.e., retrieval under stress vs. control). Salivary cortisol was measured as an index of the stress response before, and 20 min after the CPS versus control treatment. The delayed effects of testing under stress were assessed with a final recall test on Day 3. In comparison to the control condition, CPS caused significant increases in salivary cortisol, and, surprisingly resulted in enhanced memory in men. Importantly, this enhancement was not only observed in the test that immediately followed the stressor, but also in the delayed test. In women, CPS caused only marginal increases in cortisol concentrations, and retrieval remained unaffected. Our study suggests that moderate stress can improve memory performance for educationally relevant material in a long-lasting manner in healthy young men. (PsycINFO Database Record

What do we understand from clinical and mechanistic studies on acupuncture treatment for hypertension?

The outcome of acupuncture on hypertension treatment is inconclusive. This study aims to evaluate the influence of acupuncture on hypertension, based on findings from mechanistic studies over the course of decades particularly those conducted at the University of California, Irvine. Low-current and low-frequency electroacupuncture (EA) at P5–6 (overlying the median nerve) and S36–37 (overlying the deep peroneal nerve) reduced high blood pressure in a subset of patients (~70 %) with mild-to-moderate hypertension, in a slow-onset (4–8 weeks) but long-lasting (1–2 months) manner. EA inhibited cardiovascular sympathoexcitatory neurons through activation of neurons in the arcuate nucleus of the hypothalamus, the ventrolateral periaqueductal gray in the midbrain and the nucleus raphe pallidus in the medulla, through inhibiting the activity of premotor sympathetic neurons in the rostral ventrolateral medulla (rVLM). Several neurotransmitters such as glutamate, acetylcholine, opioids, GABA, nociceptin, serotonin and endocannabinoids were involved in this EA-induced hypotensive response. The long-lasting inhibition of hypertension induced by EA was related to opioids and GABA in the rVLM, neural circuitry between the arcuate and ventrolateral periaqueductal gray, and prolongation of the increase in preproenkephalin mRNA levels and enkephalin levels in the rVLM and arcuate. Moreover, the long-lasting inhibition of sympathetic activity by EA was confirmed in EA-treated hypertensive patients with decreased levels of norepinephrine, renin and aldosterone.

Prenatal exposure to glucocorticoids affects body weight, serum leptin levels, and hypothalamic neuropeptide-Y expression in pre-pubertal female rat offspring

Glucocorticoid secretion is a key endocrine response to stress. It has been reported that prenatal stress induces long-lasting alterations in body weight regulation systems, which persist after the stress has ceased. In this study, the long-term effects of prenatal glucocorticoid exposure on body weight changes and the expression of appetite-regulating factors were examined in female rats. Pregnant rats were given normal drinking water (control) or dexamethasone (1μg/mL) dissolved in drinking water (DEX) from day 13 of pregnancy until delivery. Then, the body weight change, serum leptin levels, and hypothalamic NPY mRNA levels of their offspring were examined. The DEX dams gained significantly less body weight during pregnancy than the control dams. The DEX dams’ offspring exhibited a significantly lower birth weight than the offspring of the control dams, and the same was true for body weight at postnatal days 20 and 28. The offspring of the DEX dams displayed significantly higher serum leptin levels and significantly lower hypothalamic NPY mRNA levels compared with the offspring of the control dams. Significant inverse correlations were detected between body weight and the serum leptin level, and between the serum leptin level and the hypothalamic NPY mRNA level. On the other hand, a significant positive correlation was detected between body weight and the hypothalamic NPY mRNA level. These results indicate that leptin production is increased in a long-lasting manner in offspring exposed to glucocorticoids during the prenatal period and that this results in attenuated body weight gain and hypothalamic NPY expression during the pre-pubertal period.

Chronic Corticosterone Exposure Persistently Elevates the Expression of Memory-Related Genes in the Lateral Amygdala and Enhances the Consolidation of a Pavlovian Fear Memory

Chronic exposure to stress has been widely implicated in the development of anxiety disorders, yet relatively little is known about the long-term effects of chronic stress on amygdala-dependent memory formation. Here, we examined the effects of a history of chronic exposure to the stress-associated adrenal steroid corticosterone (CORT) on the consolidation of a fear memory and the expression of memory-related immediate early genes (IEGs) in the lateral nucleus of the amygdala (LA). Rats received chronic exposure to CORT (50 μg/ml) in their drinking water for 2 weeks and were then titrated off the CORT for an additional 6 days followed by a 2 week ‘wash-out’ period consisting of access to plain water. Rats were then either sacrificed to examine the expression of memory-related IEG expression in the LA or given auditory Pavlovian fear conditioning. We show that chronic exposure to CORT leads to a persistent elevation in the expression of the IEGs Arc/Arg3.1 and Egr-1 in the LA. Further, we show that rats with a history of chronic CORT exposure exhibit enhanced consolidation of a fear memory; short-term memory (STM) is not affected, while long-term memory (LTM) is significantly enhanced. Treatment with the selective serotonin reuptake inhibitor (SSRI) fluoxetine following the chronic CORT exposure period was observed to effectively reverse both the persistent CORT-related increases in memory-related IEG expression in the LA and the CORT-related enhancement in fear memory consolidation. Our findings suggest that chronic exposure to CORT can regulate memory-related IEG expression and fear memory consolidation processes in the LA in a long-lasting manner and that treatment with fluoxetine can reverse these effects.

A pilot investigation of a pediatric surgery journal club

BackgroundThe CanMEDS competency “scholar” encompasses the creation, dissemination, application, and translation of medical knowledge. We hypothesize that a structured journal club (JC) for pediatric surgical trainees would meet these objectives in an enjoyable and long-lasting manner. MethodsA JC involving two pediatric surgery training programs was created with each session focusing on a specific study design. Pre-tests/post-tests were administered before/after each session with durability of learning assessed during the following session. Metrics analyzed included participant satisfaction and an appraisal of evidence-based medicine (EBM) principals. Test results were analyzed using the paired T-test with p<0.05 considered significant. ResultsOn average, 14 participants attended each session, with all trainees present (4). While participants believed they understood EBM principles, 40% were unfamiliar with question formulation, 48% were unfamiliar with critical appraisal tools, and 60% had not appraised an article within the previous year. Pre-test to post-test comparison yielded an improvement in mean score (20=perfect score): 10.8 to 16.9, p<0.01. Measures of participant satisfaction were uniformly positive. ConclusionA structured Pediatric Surgery Journal Club addresses scholarly training objectives in a highly satisfactory manner and yields durable learning. A web-based curriculum based on this model could serve as an important educational tool for trainees and attending staff alike.

Responsibility Formation in Medical Students in the Course of Foreign Language Study

In Ukraine formation of responsibility is a teaching paradigm in the process of studying foreign languages at higher medical educational institutions. The task of humanitarian disciplines at the medical universities is to help medical students develop self-discipline and to become better students, self-motivated learners and constructive members of society. Culture, humanization of the pedagogical process, personality-oriented education and personal qualities development are considered to be the most important aspects in humanistic education. Formation of responsibility at the English lessons is a group management. Theoretical material should be fruitful and thought-provoking, giving rare opportunity to spend time on reflecting and discussing as well as on learning. All tasks used in the process of foreign languages study should be communication-oriented and adjust students to the correct interpretation of the problematic situation that requires mental stress and stimulates the activity of students’ speech in the discussion of real-world facts. Teaching English through words and actions can help transfer solid character principles such as personal, social and moral responsibility to students in a long-lasting manner. Personal responsibility is an obligation to medical students and their future profession. Thus, teachers are to assist medical students to be seekers of responsibility and truth, and often these mean demonstrating varying opinions to find the one most suitable for presentation. Qualities of health care specialist should include responsibility, respect, humility, courage and willingness. The main humanistic values comprise mutual communication and understanding, spiritual, moral and physical health developing in the process of teaching English. A teacher must be competent, creative and know how to motivate a medical student properly trying to improve the environment in which personality of health care system is formed.

The arylpiperazine derivatives N-(4-cyanophenylmethyl)-4-(2-diphenyl)-1-piperazinehexanamide and N-benzyl-4-(2-diphenyl)-1-piperazinehexanamide exert a long-lasting inhibition of human serotonin 5-HT7 receptor binding and cAMP signaling.

We performed a detailed in vitro pharmacological characterization of two arylpiperazine derivatives, compound N-(4-cyanophenylmethyl)-4-(2-diphenyl)-1-piperazinehexanamide (LP-211) previously identified as a high-affinity brain penetrant ligand for 5-hydroxytryptamine (serotonin) type 7 (5-HT7) receptors, and its analog N-benzyl-4-(2-diphenyl)-1-piperazinehexanamide (MEL-9). Both ligands exhibited competitive displacement of [3H]-(2R)-1-[(3-hydroxyphenyl)sulfonyl]-2-[2-(4-methyl-1-piperidinyl)ethyl]pyrrolidine ([3H]-SB-269970) radioligand binding and insurmountable antagonism of 5-carboxamidotryptamine (5-CT)-stimulated cyclic adenosine monophosphate (cAMP) signaling in human embryonic kidney (HEK293) cells stably expressing human 5-HT7 receptors. They also inhibited forskolin-stimulated adenylate cyclase activity in 5-HT7-expressing HEK293 cells but not in the parental cell line. The compounds elicited long-lasting (at least 24 h) concentration-dependent inhibition of radioligand binding at 5-HT7-binding sites in whole-cell radioligand binding assays, after pretreatment of the cells with the compounds and subsequent compound removal. In cAMP assays, pretreatment of cells with the compounds rendered 5-HT7 receptors unresponsive to 5-CT and also rendered 5-HT7-expressing HEK293 cells unresponsive to forskolin. Compound 1-(2-biphenyl)piperazine (RA-7), a known active metabolite of LP-211 present in vivo, was able to partially inhibit 5-HT7 radioligand binding in a long-lasting irreversible manner. Hence, LP-211 and MEL-9 were identified as high-affinity long-acting inhibitors of human 5-HT7 receptor binding and function in cell lines. The detailed in vitro characterization of these two pharmacological tools targeting 5-HT7 receptors may benefit the study of 5-HT7 receptor function and it may lead to the development of novel selective pharmacological tools with defined functional properties at 5-HT7 receptors.

Anandamide Transforms Noncopulating Rats into Sexually Active Animals

Noncopulating (NC) male rats are apparently normal and healthy animals that will not mate despite repeated exposure to sexually receptive females. Several lines of evidence suggest the involvement of endogenous opioids in this sexual inhibitory state. Endogenous opioids and endocannabinoids are neuromodulators of neurotransmitter release, although through different mechanisms. To establish if the endocannabinoid anandamide was able to induce sexual behavior expression in male rats classified as noncopulators. NC male rats were intraperitoneally (i.p.) injected with anandamide or vehicle and tested for copulatory behavior with a receptive female during 120 minutes. Fourteen days after anandamide or vehicle injection, the animals were subjected to a second sexual behavior test during 60 minutes. The percentage of rats showing male sexual behavior responses: mount, intromission, ejaculation, and copulation resumption after ejaculation and the specific sexual behavior parameters were quantified. Anandamide injection induced sexual behavior expression in 50% of previously NC rats, while the NC animals injected with vehicle did not show sexual behavior. The responding animals executed several successive ejaculatory series and were still capable of showing sexual behavior 14 days after anandamide injection. Copulation in these rats (the first copulatory series) was characterized by a large number of mounts and intromissions preceding ejaculation, as well as by statistically significant increases in the latencies to mount, intromit, and ejaculate when compared with the sexual performance of sexually naïve animals copulating for the first time. The endocannabinoid anandamide transforms previously NC rats into sexually active animals, capable of showing sexual behavior in a long-lasting manner. Only half of the NC population responds to anandamide injection, suggesting that different mechanisms underlie the sexual inhibition of NC rats. The endocannabinoid system seems to play a role in the regulation of male rat sexual behavior expression.