Antimicrobial,anticoagulant, and cytotoxic evaluation of multidrug resistance of new 1,4-dihydropyridine derivatives

A new series of 1,4-dihydropyridine derivatives (2a–h, 3a–e, and 4a–e) were systematically designed and synthesized via ultrasound irradiation methods with easy work-up and good yields. Compounds structures were confirmed by IR, ¹H NMR, ¹³C NMR, and mass spectra. The synthesized compounds were screened for both antimicrobial and anticoagulant activities. Compound 2e (MIC: 0.25?μg/mL) was highly active against Escherichia coli and compound 2c (MIC: 0.5?μg/mL) was also highly active against Pseudomonas aeruginosa compared with ciprofloxacin. (MIC: 1?μg/mL) The antifungal activity of 2c (MIC: 0.5?μg/mL) against Candida albicans was high relative to that of clotrimazole (MIC: 1?μg/mL). Anticoagulant activity was determined by activated partial thromboplastin time (APTT) and prothrombin time (PT) coagulation assays. Compound 4-(4-hydroxyphenyl)-2,6-dimethyl-N³,N⁵-bis(5-phenyl-1,3,4-thiadiazol-2-yl)-1,4-dihydropyridine-3,5-dicarboxamide 3d (>1000?s in APTT assays) was highly active in anticoagulant screening compared with the reference of heparin.Cytotoxicity was evaluated using HepG2 (liver), HeLa (cervical), and MCF-7 (breast) cancer cell lines, with high toxicities observed for 2c (GI₅₀?=?0.02?μm) against HeLa cell line and 2e (GI₅₀?=?0.03?μm) equipotant against MCF-7 cell line. Therefore, the compounds 2e, 2c and 3d can serve as lead molecules for the development of new classes of antimicrobial and anticoagulant agent.     

Epidemiology and risk factors associated with Anaplasma marginale infection of cattle in Peninsular Malaysia

Bovine anaplasmosis is a major concern to cattle farming in most parts of the world. Anaplasmosis negatively impacts the profitability of cattle farming by reducing the production, reproduction, and draft ability of cattle. Here, we report results from a one-year cross sectional study to determine the epidemiology and the risk factors for Anaplasma marginale infection of cattle in Peninsular Malaysia. Examination of one thousand and forty five blood samples of apparently healthy cattle from forty-three farms in all the states of Peninsular Malaysia by polymerase chain reaction (PCR) assay revealed an overall prevalence of A. marginale infection of cattle of 72.6%, showing high endemicity of this heamoprotozoan among cattle in the country. Cattle breeds, production type, herd owner, herd size, management system, farm size, farm age, prophylactic treatment against blood parasites, presence of ticks, frequency of deticking, zones, closeness to forest, closeness to waste area, closeness to human settlement and closeness to body of water were the risk factors significantly associated (P?<?0.05) with the detection of A. marginale in cattle. Results of this first molecular study on the epidemiology and risk factors for A. marginale infection of cattle from all the states of Peninsular Malaysia suggest policies and strategies for the prevention and control of the parasite to improve profitability of cattle farming in the country.     

Inhibition of gut proteases and development of dengue vector, Aedes aegypti by Allium sativum protease inhibitor

The paper describes the bio efficacy of a protease inhibitor; isolated from Allium sativum ‘garlic’ (ASPI); against Aedes aegypti mosquito, a well-known transmitter of dengue and Chikungunya. The purification of protease inhibitor from Allium sativum ‘garlic’ (ASPI) was carried out by ammonium sulfate precipitation followed by Fast Protein Liquid Chromatography using akta DEAE-Cellulose column. The protein fraction demonstrating trypsin inhibitory activity was further evaluated for its insecticidal activity using gut protease inhibition assay and larvicidal assay. ASPI is an inhibitor of porcine trypsin (IC₅₀ of 650.726?μg/mL) and has molecular weight of ~15?kDa determined by SDS PAGE similar to other inhibitors of the Kunitz-type family (14–26?kDa). ASPI demonstrated 50% reduced activity of Ae. aegypti midgut proteases and showed a dose-dependent acute toxicity on Ae. aegypti 3rd instars exhibiting LC₅₀ value of ~50.827?μg/mL. After ten days of larval exposure ASPI resulted in a 24-h delay of larval development and ~72% mortality at 61.5?μg/mL. These results suggest that ASPI may serve as potent insecticidal agent and hence opens a new gateway in the field of phyto-remediation.     

Expression of hemopoietic histocompatibility antigens on H-2-loss variants of F1 hybrid lymphoma cells: evidence consistent with trans gene regulation

H-2 heterozygous marrow stem cells, lymphoid progenitor cells, and leukemia/lymphoma cells do not express hemopoietic or hybrid histocompatibility (Hh) antigens, which are important transplantation antigens recognized during the rejection of normal or neoplastic hemopoietic cells. The Hh-1b determinant of the H-2b haplotype maps to the D region of H-2. We have tested the hypothesis that gene(s) at or near H-2D of the H-2d haplotype down-regulate the expression of Hh-1b in the trans configuration. We used Abelson leukemia virus-transformed pre-B lymphoma cells (ACCb) of BALB/c X BALB.B (H-2d X H-2b) origin, as well as variant lines of ACCb, which were selected for resistance to monoclonal anti-H-2 antibodies plus complement. B6D2F1 (H-2b X H-2d), C3B6F1 (H-2k X H-2b), or B6 (H-2b) mice were infused with inocula of 5 X 10(6) B6 bone marrow cells (BMC). Proliferation of donor-derived marrow cells was judged in terms of DNA synthesis by measuring the splenic incorporation of 5-iodo(125I)-2'-deoxyuridine (IUdR) 5 days after cell transfer. B6 BMC grew much better in B6 than in F1 hybrid host mice, an expression of "hybrid resistance". As observed previously, the injection of EL-4 (H-2b, Hh-1b) tumor cells prior to infusion of B6 (H-2b, Hh-1b) BMC enhanced the growth of B6 BMC in F1 hybrid mice. Therefore, this in vivo "cold target cell competition" type of assay can be used to detect the expression of Hh-1b antigens. Unlike EL-4 (H-2b) cells, hybrid resistance was not affected by prior infusion of (H-2b X H-2d) heterozygous ACCb cells. In contrast, three ACCb variant cell lines, H-2d-, Ld-Dd-, and Dd-, enhanced the growth of B6 BMC in F1 hosts. The ACCb H-2b- cell line did not affect hybrid resistance to B6 BMC. The loss of gene expression on the H-2d chromosome at or very near the H-2Dd locus is correlated with the appearance Hh-1b, as determined by the in vivo cold target competition assay. These results support the hypothesis that heterozygous cells possess trans-acting, dominant, down-regulatory genes mapping near H-2D that control the Hh-1 phenotype of lymphoid tumor cells.     

Changes in carbohydrates and lipids during embryonic development ofAntheraea mylitta (Lepidoptera)

Changes in carbohydrate and lipid metabolism during embryonic development inAntheraea mylitta were studied. While carbohydrates were metabolized during early embryogenesis, lipids were catabolised at the later stages. A significant increase in both total carbohydrates and glycogen on days 5 and 6 suggested the concurrent occurrence of both gluconeogenesis and glycogenesis. As the development of the embryo proceeds, both lipids and carbohydrates were utilised, resulting in the increase in the concentration of citrate, pyruvate and lactate.     

The Hha–TomB toxin–antitoxin module in Salmonella enterica serovar Typhimurium limits its intracellular survival profile and regulates host immune response

Cell Biology and Toxicology - The key to bacterial virulence relies on an exquisite balance of signals between microbe and hosts. Bacterial toxin–antitoxin (TA) system is known to play a...     

Metalloids in plants: A systematic discussion beyond description

Metalloids represent a wide range of elements with intermediate physiochemical properties between metals and non-metals. Many of the metalloids, like boron, selenium, and silicon are known to be essential or quasi-essential for plant growth. In contrast, metalloids viz. arsenic and germanium are toxic to plant growth. The toxicity of metalloids largely depends on their concentration within the living cells. Some elements, at low concentration, may be beneficial for plant growth and development; however, when present at high concentration, they often exert negative effects. In this regard, understanding the molecular mechanisms involved in the uptake of metalloids by roots, their subsequent transport to different tissues and inter/intra-cellular redistribution has great importance. The mechanisms of metalloids' uptake have been well studied in plants. Also, various transporters, as well as membrane channels involved in these processes, have been identified. In this review, we have discussed in detail the aspects concerning the positive/negative effects of different metalloids on plants. We have also provided a thorough account of the uptake, transport, and accumulation, along with the molecular mechanisms underlying the response of plants to these metalloids. Additionally, we have brought up the previous theories and debates about the role and effects of metalloids in plants with insightful discussions based on the current knowledge.     

Patterns of Nucleotide Substitution in Mitochondrial Protein Coding Genes of Vertebrates

Maximum likelihood methods were used to study the differences in substitution rates among the four nucleotides and among different nucleotide sites in mitochondrial protein-coding genes of vertebrates. In the 1st+2nd codon position data, the frequency of nucleotide G is negatively correlated with evolutionary rates of genes, substitution rates vary substantially among sites, and the transition/transversion rate bias (R) is two to five times larger than that expected at random. Generally, largest transition biases and greatest differences in substitution rates among sites are found in the highly conserved genes. The 3rd positions in placental mammal genes exhibit strong nucleotide composition biases and the transitional rates exceed transversional rates by one to two orders of magnitude. Tamura-Nei and Hasegawa-Kishino-Yano models with gamma distributed variable rates among sites (gamma parameter, α) adequately describe the nucleotide substitution process in 1st+2nd position data. In these data, ignoring differences in substitution rates among sites leads to largest biases while estimating substitution rates. Kimura's two-parameter model with variable-rates among sites performs satisfactorily in likelihood estimation of R, α, and overall amount of evolution for 1st+2nd position data. It can also be used to estimate pairwise distances with appropriate values of α for a majority of genes.