Sex-specific endothelial dysfunction induced by high-cholesterol diet in rats: The role of protein tyrosine kinase and nitric oxide

Background and aimsAtherosclerosis is a chronic process playing a crucial role in the pathogenesis of cardiovascular disease. Sex-specific differences in the incidence of atherosclerosis indicate that estrogen has a protective effect on the cardiovascular disease. However, the role of sex on endothelium responses in animal models of high cholesterol (HC) diet-induced atherosclerosis has not been fully investigated. This study was aimed to investigate vascular responses in HC-fed rats.Methods and resultsMale and female Sprague rats (12-week-old) were treated with either a standard diet (n = 12 of each sex) or an HC enriched diet (n = 12 of each sex) containing 2% cholesterol for 24 weeks. HC treated animals (both sexes) showed increased levels of total cholesterol, LDL-cholesterol, triglyceride and blood pressure (BP) compared to control rats. While the BP of control rats (both sexes) was increased following aminoguanidine administration (AG, 100 mg/kg i.p.), it was not changed in HC animals (both sexes). The hypotensive effect of acetylcholine was significantly impaired in male HC-treated rats. In vitro experiments demonstrated that aortic rings from HC group (both sexes) had an increased contractile response to phenylephrine and a decreased vasodilatory response to acetylcholine. The vasorelaxant effect of acetylcholine in HC rats (only male) was improved by applying 10^?5 M genistein (tyrosine kinase inhibitor) or AG.ConclusionHC diet alters endothelium function through Nitric oxide (NO) and tyrosine kinase pathways in male rats.     

Sentinel lymph node localization and staging with a low-dose of superparamagnetic iron oxide (SPIO) enhanced MRI and magnetometer in patients with cutaneous melanoma of the extremity - The MAGMEN feasibility study

BackgroundIn patients with melanoma, sentinel lymph node (SLN) status is pivotal for treatment decisions. Current routine for SLN detection combines Technetium^99m (Tc⁹⁹) lymphoscintigraphy and blue dye (BD). The primary aim of this study was to examine the feasibility of using a low dose of superparamagnetic iron oxide (SPIO) injected intracutaneously to detect and identify the SLN, and the secondary aim was to investigate if a low dose of SPIO would enable a preoperative MRI-evaluation of SLN status.MethodsPatients with melanoma of the extremities were eligible. Before surgery, a baseline MRI of the nodal basin was followed by an injection of a low dose (0.02–0.5 mL) of SPIO and then a second MRI (SPIO-MRI). Tc⁹⁹ and BD was used in parallel and all nodes with a superparamagnetic and/or radioactive signal were harvested and analyzed.ResultsFifteen patients were included and the SLNB procedure was successful in all patients (27 SLNs removed). All superparamagnetic SLNs were visualized by MRI corresponding to the same nodes on scintigraphy. Micrometastatic deposits were identified in four SLNs taken from three patients, and SPIO-MRI correctly predicted two of the metastases. There was an association between MRI artefacts in the lymph node and the dose SPIO given.DiscussionIt is feasible to detect SLN in patients with melanoma using a low dose of SPIO injected intracutaneously compared with the standard dual technique. A low dose of SPIO reduces the lymph node MRI artefacts, opening up for a non-invasive assessment of SLN status in patients with cancer.     

The changes in,and relationship between,plasma nitric oxide and corticotropin‐releasing hormone in patients with major depressive disorder

There is strong evidence of roles of the hypothalamus‐pituitary‐adrenal axis and nitric oxide (NO) synthase‐NO system in depression, but the relationship between them is unknown. The aim of this study, therefore, was to elucidate whether there is any correlation between NO and corticotropin‐releasing hormone (CRH) in major depressive disorder (MDD) patients. In 16 outpatients with MDD and 18 healthy controls, the plasma amino acids citrulline (Cit) and arginine (Arg) were determined by high‐performance liquid chromatography, and CRH levels was measured by radioimmunoassay. The Cit/Arg ratio was calculated as an index of NO synthesis. Correlations between NO and CRH were examined with the Spearman test. Before treatment, no significant correlation was observed between the plasma NO level and CRH levels in MDD patients. The plasma NO levels were significantly higher in MDD patients. A significant correlation was found between NO levels and Hamilton Depression Rating Scale (HAMD) scores in MDD patients. The plasma CRH levels were significantly higher in MDD patients than in controls. After monotherapy for 2 months, the NO levels had dramatically declined but were also higher than those in the controls. This study is the first report of the absence of a significant correlation between plasma NO and CRH levels, although both levels are elevated in MDD patients. Furthermore, the strong links between the plasma NO levels and the HAMD scores, as well as the increased NO reduction after remission, suggest that NO plays a key role in depression and may be an indicator of therapeutic success.     

Arginase and α‐smooth muscle actin induction after hyperoxic exposure in a mouse model of bronchopulmonary dysplasia

The L‐arginine/NO pathway is an important regulator of pulmonary hypertension, the leading cause of mortality in patients with the chronic lung disease of prematurity, bronchopulmonary dysplasia. L‐arginine can be metabolized by NO synthase (NOS) to form L‐citrulline and NO, a potent vasodilator. Alternatively, L‐arginine can be metabolized by arginase to form urea and L‐ornithine, a precursor to collagen and proline formation important in vascular remodelling. In the current study, we hypothesized that C3H/HeN mice exposed to prolonged hyperoxia would have increased arginase expression and pulmonary vascular wall cell proliferation. C3H/HeN mice were exposed to 14 days of 85% O₂ or room air and lung homogenates analyzed by western blot for protein levels of arginase I, arginase II, endothelial NOS (eNOS), ornithine decarboxylase (ODC), ornithine aminotransferase (OAT), and α‐smooth muscle actin (α‐SMA). Hyperoxia did not change arginase I or eNOS protein levels. However, arginase II protein levels were 15‐fold greater after hyperoxia exposure than in lungs exposed to room air. Greater protein levels of ODC and OAT were found in lungs following hyperoxic exposure than in room air animals. α‐SMA protein levels were found to be 7‐fold greater in the hyperoxia exposed lungs than in room air lungs. In the hyperoxia exposed lungs there was evidence of greater pulmonary vascular wall cell proliferation by α‐SMA immunohistochemistry than in room air lungs. Taken together, these data are consistent with a more proliferative vascular phenotype, and may explain the propensity of patients with bronchopulmonary dysplasia to develop pulmonary hypertension.     

Demonstration of pharmaceutical tablet coating process by injection molding technology

We demonstrate the coating of tablets using an injection molding (IM) process that has advantage of being solvent free and can provide precision coat features. The selected core tablets comprising 10% w/w griseofulvin were prepared by an integrated hot melt extrusion-injection molding (HME-IM) process. Coating trials were conducted on a vertical injection mold machine. Polyethylene glycol and polyethylene oxide based hot melt extruded coat compositions were used. Tablet coating process feasibility was successfully demonstrated using different coating mold designs (with both overlapping and non-overlapping coatings at the weld) and coat thicknesses of 150 and 300?μm. The resultant coated tablets had acceptable appearance, seal at the weld, and immediate drug release profile (with an acceptable lag time). Since IM is a continuous process, this study opens opportunities to develop HME-IM continuous processes for transforming powder to coated tablets.     

Quinoxaline and quinoxaline‐1,4‐di‐N‐oxides: An emerging class of antimycobacterials

Tuberculosis (TB) is a highly dreaded, infectious, chronic, airborne disease affecting more than two million people all around the world, with more than eight million cases every calendar year. TB is the second leading infectious cause of death after HIV/AIDS. Over the past few decades, numerous efforts have been undertaken to develop new anti‐TB agents. The current frontline therapy for TB consists of administering three or more different drugs (usually isoniazid, rifampin, pyrazinamide, and ethambutol) over an extended period of time. But these drugs will take 6–12 months to cure TB, along with many side effects; hence, there is an urgent need to explore new anti‐TB agents. Quinoxaline derivatives are a class of compounds that show a spectrum of biological properties and the interest in these compounds is exponentially growing within the field of medicinal chemistry. Quinoxaline‐1,4‐di‐N‐oxide derivatives have shown to improve the biological results and are endowed with anti‐viral, anti‐cancer, anti‐bacterial, and anti‐protozoal activities with application in many other therapeutic areas. Since quinoxaline derivatives are regarded as a new class of effective anti‐TB candidates, their 1,4‐di‐N‐oxide analogues may show promising in vitro and in vivo anti‐TB activities and might be able to prevent the drug resistance to a certain extent. Therefore, the main aim of this review is to focus on important quinoxaline and quinoxaline‐1,4‐di‐N‐oxide analogues that have shown anti‐TB activities, and their structure–activity relationships for designing anti‐TB agents with better efficacies. The present review will be helpful in providing insights for rational designs of more active and less toxic quinoxaline‐based anti‐TB prodrugs.

     

Can we increase the speed and efficacy of antidepressant treatments? Part II. Glutamatergic and RNA interference strategies

In the second part we focus on two treatment strategies that may overcome the main limitations of current antidepressant drugs. First, we review the experimental and clinical evidence supporting the use of glutamatergic drugs as fast-acting antidepressants. Secondly, we review the involvement of microRNAs (miRNAs) in the pathophysiology of major depressive disorder (MDD) and the use of small RNAs (e.g.., small interfering RNAs or siRNAs) to knockdown genes in monoaminergic and non-monoaminergic neurons and induce antidepressant-like responses in experimental animals.The development of glutamatergic agents is a promising venue for antidepressant drug development, given the antidepressant properties of the non-competitive NMDA receptor antagonist ketamine. Its unique properties appear to result from the activation of AMPA receptors by a metabolite [(2 S,6 S;2 R,6 R)-hydroxynorketamine (HNK)] and mTOR signaling. These effects increase synaptogenesis in prefrontal cortical pyramidal neurons and enhance serotonergic neurotransmission via descending inputs to the raphe nuclei. This view is supported by the cancellation of ketamine's antidepressant-like effects by inhibition of serotonin synthesis.We also review existing evidence supporting the involvement of miRNAs in MDD and the preclinical use of RNA interference (RNAi) strategies to target genes involved in antidepressant response. Many miRNAs have been associated to MDD, some of which e.g., miR-135 targets genes involved in antidepressant actions. Likewise, SSRI-conjugated siRNA evokes faster and/or more effective antidepressant-like responses. Intranasal application of sertraline-conjugated siRNAs directed to 5-HT_1A receptors and SERT evoked much faster changes of pre- and postsynaptic antidepressant markers than those produced by fluoxetine.     

A comprehensive review on Brigatinib – A wonder drug for targeted cancer therapy in non-small cell lung cancer

The mortality rate in patients suffering from non-small cell lung cancer (NSCLC) is quite high. This type of cancer mainly occurs due to rearrangements in the anaplastic lymphoma kinase (ALK) gene which leads to form an oncogene of fused gene NPM-ALK. Brigatinib is recently approved by FDA in April 2017 as a potent tyrosine kinase inhibitor (TKI) for the NSCLC therapy. In the present scenario, it is no less than a wonder drug because it is indicated for the treatment of advanced stages of metastatic ALK positive NSCLC, a fatal disease to overcome the resistance of various other ALK inhibitors such as crizotinib, ceritinib and alectinib. In addition to ALK, it is also active against multiple types of kinases such as ROS1, Insulin like growth factor-1Receptor and EGFR. It can be synthesized by using N-[2-methoxy-4-[4-(dimethylamino) piperidin-1-yl] aniline] guanidine and 2,4,5-trichloropyrimidine respectively in two different ways. Its structure consists of mainly dimethylphosphine oxide group which is responsible for its pharmacological activity. It is active against various cell lines such as HCC78, H2228, H23, H358, H838, U937, HepG2 and Karpas- 299. Results of ALTA (ALK in Lung Cancer Trial of AP26113) phase ½ trial shows that 90?mg of brigatinib for 7?days and then 180?mg for next days is effective in the treatment of NSCLC. Brigatinib has been shown to have favorable risk benefit profile and is a safer drug than the available cytotoxic chemotherapeutic agents. In comparison to other FDA approved drugs for the same condition, it causes fewer minor adverse reactions which can be easily managed either by changing the dose or by providing good supportive care. This article is intended to provide readers with an overview of chemistry, pharmacokinetic, pharmacodynamic and safety profile of brigatinib, which addresses an unmet medical need.     

Chitosan-based zinc oxide nanoparticle for enhanced anticancer effect in cervical cancer: A physicochemical and biological perspective

In this study, chitosan-assembled zinc oxide nanoparticle (CZNP) was successfully prepared for evaluated for its anticancer efficacy against cervical cancer cells. The CZNP particles were nanosized and spherical in shape. The zinc oxide nanoparticle (ZNP) and CZNP showed significant cytotoxicity in cervical cancer cells in a concentration-dependent manner. Results showed that the enhanced cytotoxicity was mainly attributed to the reactive oxygen species (ROS) generation in the cancer cells. The apoptosis assay further revealed that apoptosis was the main reason behind the cell killing effect of the zinc oxide nanoparticles. The apoptosis was further confirmed by the nuclear chromatin assay. Live dead assay showed increased red fluorescent cell for CZNP treated cancer cells. Overall, metal oxide present in nanoparticulate dimensions will be advantageous in imparting the cytotoxicity to cervical cancer cell.