Variants of endothelial nitric oxide synthase gene are associated with components of metabolic syndrome in an Arab population

Genetics plays a crucial role in the development of metabolic syndrome (MetS). Here we examined the association between endothelial nitric oxide synthase (eNOS) gene polymorphisms and MetS in a Saudi Arabian cohort to extend the understanding of the genetic basis of MetS in diverse ethnic populations. Anthropometric, clinical and biochemical parameters as well as genotyping for 894G>T, -786T>C variants of eNOS gene by PCR-RFLP and 4a/b by direct PCR were performed in 886 Saudi Arabians (477 MetS and 409 Non-MetS). The genotype distribution (TT, p=0.001; TC, p=0.001; TC+CC, p=0.001) and allele (T, p=0.007; C, p=0.007) frequency of the -786T>C SNP were significantly different between Non-MetS and MetS subjects which remained significant after Bonferroni correction. Moreover: 1) the GT and GT+TT genotypes of the 894G>T SNP were associated with elevated blood pressure (p=0.017, and p=0.022, respectively); 2) the ab variant of 4a/b polymorphism was associated with decreased HDL levels (p= 0.044); and 3) the TC+CC genotype and C allele of the -786T>C SNP were associated with increased fasting glucose levels (p=0.039, and p=0.028, respectively). Also, G-a-C was identified as the risk haplotype for MetS susceptibility (p=0.034). The results suggest a significant association of 894G>T, 4a/b and -786T>C polymorphisms with MetS and its components is present in an Arab population. A genetic predisposition to develop abnormal metabolic phenotypes, consistent with an increased prevalence of metabolic phenotypes can be detected in this ethnic group.     

Maternal–fetal transport kinetics of manganese in perfused human placental lobule in vitro

Objective: There have been no detailed reports relating to maternal–fetal transport kinetics of manganese, an essential trace element in the human pregnancies, and hence we have attempted to study the transport kinetics of this trace element in the human placenta in vitro.

Methods: Human placentae from normal uncomplicated pregnancies were collected postpartum. Manganese chloride solution (GFS Chem Inc., Columbus, OH), 10 times the physiological concentrations, along with antipyrine (Sigma Chem Co., St. Louis, MO) as reference marker were then injected as a single bolus (100?µl) into the maternal arterial circulation of perfused placental lobules and perfusate samples collected from maternal and fetal circulations over a period of five minutes. National Culture and Tissue Collection medium, diluted with Earle’s buffered salt solution was used as the perfusate and serial perfusate samples from fetal venous perfusate collected for a period of 30?min. Concentration of manganese in perfusate samples was assessed by atomic absorption spectrophotometry, while that of antipyrine was assessed by spectrophotometry. Transport kinetics of substances studied were computed using established permeation parameters.

Results: Differential transport rates of manganese and antipyrine in 12 perfusions differed significantly for 25.75, 90% efflux fractions (ANOVA test, p?<?0.05), while those of 10 and 50% efflux fractions were not significantly different between the study and reference substances. Transport fraction (TF) of manganese averaged 54.9% of bolus dose in 12 perfusions, whereas that of antipyrine averaged 89% of bolus dose, representing 61.80% of reference marker TF. The difference observed in TF values of manganese and antipyrine was statistically significant (Student’s t-test, p?<?0.05). Pharmacokinetic parameters such as area under the curve, clearance, absorption rate, elimination rate of manganese compared to reference marker were significantly different (ANOVA test, p?<?0.05) between the study and reference substances.

Conclusions: Our studies show for the first time maternal–fetal transport kinetics of manganese in human placenta in vitro. Considering the restricted transfer of this essential trace element despite its small molecular weight, we hypothesize possibility of active transport of manganese across the human placental membrane. Further studies relating to manganese placental transport in “diabetic model” placental perfusions are in progress.     

Transient receptor potential vanilloid 1 expression and function in splenic dendritic cells: a potential role in immune homeostasis

Neuro‐immune interactions, particularly those driven by neuropeptides, are increasingly implicated in immune responses. For instance, triggering calcium‐channel transient receptor potential vanilloid 1 (TRPV1) on sensory nerves induces the release of calcitonin‐gene‐related peptide (CGRP), a neuropeptide known to moderate dendritic cell activation and T helper cell type 1 polarization. Despite observations that CGRP is not confined to the nervous system, few studies have addressed the possibility that immune cells can respond to well‐documented ‘neural’ ligands independently of peripheral nerves. Here we have identified functionally relevant TRPV1 on primary antigen‐presenting cells of the spleen and have demonstrated both calcium influx and CGRP release in three separate strains of mice using natural agonists. Furthermore, we have shown down‐regulation of activation markers CD80/86 on dendritic cells, and up‐regulation of interleukin‐6 and interleukin‐10 in response to CGRP treatment. We suggest that dendritic cell responses to neural ligands can amplify neuropeptide release, but more importantly that variability in CGRP release across individuals may have important implications for immune cell homeostasis.     

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.     

Identification and characterization of undifferentiated mast cells in mouse bone marrow

Sequential immunomagnetic isolation with 2 monoclonal antibodies was used to purify and characterize an undifferentiated mast cell in adult mouse bone marrow that had not been previously recognized. This cell represents 0.02% of the cells in the bone marrow, is CD34(+), CD13(+), and c-kit(+), and does not express FcepsilonRI. However, by polymerase chain reaction (PCR) the cell contains message for the alpha and beta subunits of FcepsilonRI, mast cell-specific proteases, and carboxypeptidase A. Morphologically, this cell has a large nucleus, little cytoplasm, few cytoplasmic organelles, and no cytoplasmic granules. In vitro, in the presence of interleukin-3 (IL-3) and stem cell factor (SCF) these cells differentiate only into a granulated mast cell that now expresses CD13, c-kit, mast cell-specific gangliosides, FcepsilonRI, and binds immunoglobulin E (IgE). When injected into lethally irradiated mice, these cells are able to reconstitute the mast cell population in the spleen.     

Breakdown of Phosphatidylserine Asymmetry Following Treatment of Erythrocytes with Lumefantrine

Background: Lumefantrine, a commonly used antimalarial drug, inhibits hemozoin formation in parasites. Several other antimalarial substances counteract parasitemia by triggering suicidal death or eryptosis of infected erythrocytes. Eryptosis is characterized by cell shrinkage and cell membrane scrambling leading to phosphatidylserine-exposure at the erythrocyte surface. Signaling involved in eryptosis include increase of cytosolic Ca²⁺-activity ([Ca²⁺]_i), formation of ceramide, oxidative stress and/or activation of p38 kinase, protein kinase C (PKC), or caspases. The present study explored, whether lumefantrine stimulates eryptosis. Methods: Cell volume has been estimated from forward scatter, phosphatidylserine-exposure from annexin V binding, [Ca²⁺]_i from Fluo3-fluorescence, reactive oxygen species from 2'',7''-dichlorodihydrofluorescein-diacetate fluorescence, content of reduced glutathione (GSH) from mercury orange fluorescence, and ceramide abundance from binding of fluorescent antibodies in flow cytometry. Results: A 48 h exposure to lumefantrine (3 µg/mL) was followed by a significant increase of annexin-V-binding without significantly altering forward scatter, [Ca²⁺]_i, ROS formation, reduced GSH, or ceramide abundance. The annexin-V-binding following lumefantrine treatment was not significantly modified by p38 kinase inhibitors SB203580 (2 μM) and p38 Inh III (1 μM), PKC inhibitor staurosporine (1 µM) or pancaspase inhibitor zVAD (1 or 10 µM). Conclusions: Lumefantrine triggers cell membrane scrambling, an effect independent from entry of extracellular Ca²⁺, ceramide formation, ROS formation, glutathione content, p38 kinase, PKC or caspases.     

Successful treatment of relapsing autoimmune thrombotic thrombocytopenic purpura with rituximab

Thrombotic thrombocytopenic purpura (TTP) is a rare but life‐threatening condition characterized by thrombotic microangiopathy. The standard treatment for TTP is plasmapheresis. For refractory or relapsing cases, various immunosuppressive agents have been tried, and among them rituximab has shown promising results. TTP is rarer in the pediatric age group and the use of rituximab in children with TTP is limited. Reported herein is the successful treatment of relapsing autoimmune TTP with rituximab in a 12‐year‐old girl.