Native root-nodule bacteria of traditional soybean-growing areas of northern Thailand

Over 1500 root-nodule bacteria were isolated from a range of uninoculated soybeans, and one cowpea, trap-hosts, sown in 1985 into traditional soybean-growing areas of soybean-growing areas of northern Thailand. Most isolates were slow-growing Bradyrhizobium japonicum. Using a modified bottle-jar technique, 586 of the isolates were tested with a range of soybean hosts and one cowpea host. The results indicated:

Syntheses of NAMDA derivatives inhibiting NO production in BV-2 cells stimulated with lipopolysaccharide

Sixteen derivatives of N-acetyl-3-O-methyldopamine (NAMDA), an inhibitor of BH4 synthesis, were designed and synthesized. The ability of these derivatives to inhibit NO and BH4 production by lipopolysaccharide-stimulated BV-2 microglial cells was determined. While NAMDA at 100 microM inhibited NO and BH4 production by only about 20%, its catecholamide 8, indole 23 derivative, 13, and N-acetyl tetrahydroisoquinoline 25 inhibited the NO production by >50% at the same concentration. In particular, 13 and 25 inhibited both NO and BH4 production to similar degrees, which suggested that these compounds might inhibit NO production by blocking BH4-dependent dimerization of the newly synthesized iNOS monomer.     

Inhibition of human cytochromes P450 2A6 and 2A13 by flavonoids,acetylenic thiophenes and sesquiterpene lactones from Pluchea indica and Vernonia cinerea

The human liver cytochrome P450 (CYP) 2A6 and the respiratory CYP2A13 enzymes play role in nicotine metabolism and activation of tobacco-specific nitrosamine carcinogens. Inhibition of both enzymes could offer a strategy for smoking abstinence and decreased risks of respiratory diseases and lung cancer. In this study, activity-guided isolation identified four flavonoids 1–4 (apigenin, luteolin, chrysoeriol, quercetin) from Vernonia cinerea and Pluchea indica, four hirsutinolide-type sesquiterpene lactones 5–8 from V. cinerea, and acetylenic thiophenes 9–11 from P. indica that inhibited CYP2A6- and CYP2A13-mediated coumarin 7-hydroxylation. Flavonoids were most effective in inhibition against CYP2A6 and CYP2A13, followed by thiophenes, and hirsutinolides. Hirsutinolides and thiophenes exhibited mechanism-based inhibition and in irreversible mode against both enzymes. The inactivation kinetic K_I values of hirsutinolides against CYP2A6 and CYP2A13 were 5.32–15.4 and 0.92–8.67 µM, respectively, while those of thiophenes were 0.11–1.01 and 0.67–0.97 µM, respectively.     

Cell-penetrable nanobodies (transbodies) that inhibit the tyrosine kinase activity of EGFR leading to the impediment of human lung adenocarcinoma cell motility and survival

Most patients suffering from non–small cell lung cancer (NSCLC) have epidermal growth factor receptor (EGFR) overexpression. Currently, EGFR tyrosine kinase inhibitors (TKIs) that act as the ATP-analogs and monoclonal antibodies (MAbs) to EGFR-ectodomain that block intracellular signaling are used for the treatment of advanced NSCLC. Unfortunately, adverse effects due to the TKI off-target and drug resistance occur in a significant number of the treated patients while some NSCLC genotypes do not respond to the therapeutic MAbs. Thus, a more effective remedy for the treatment of EGFR-overexpressed cancers is deemed necessary. In this study, VH/V_HH displayed-phage clones that are bound to recombinant EGFR-TK were fished-out from a humanized-camel VH/V_HH phage display library. VH/V_HH of three phage-infected Escherichia coli clones (VH18, V_HH35, and VH36) were linked molecularly to nonaarginine (R9) for making them cell penetrable. R9-VH18, R9-V_HH35, and R9-VH36 were cytotoxic to human adenocarcinomic alveolar basal epithelial cells (A549) at the fifty percent inhibitory concentration (IC₅₀) 0.181 ± 0.132, 0.00961 ± 0.00516, and 0.00996 ± 0.00752 μM, respectively, which were approximately 1000-fold more effective than small molecular TKIs. R9-VH18 and R9-VH36 also delayed cancer cell migration in a scratch-wound assay. Computerized homology modeling and intermolecular docking revealed that VH18 and V_HH35 used CDR3 to interact with EGFR-TK residues close to the catalytic site, which might sterically hinder the ATP-binding of the TK; VH36 used CDR2 to bind at the asymmetric dimerization surface, which might disrupt EGFR dimerization leading to inhibition of intracellular signaling. The humanized-cell penetrable nanobodies have a high potential for developing further towards a clinical application.     

FTIR spectra signatures reveal different cellular effects of EGFR inhibitors on nonsmall cell lung cancer cells

ATP‐analogue inhibitors, Gefitinib (Iressa) and Erlotinib (Tarceva) had been approved for advanced and metastatic nonsmall cell lung cancer (NSCLC) cells against tyrosine kinase domain of epidermal growth factor receptor (EGFR). Many techniques have been developed to better understand the drug mechanism which is multistep, time‐consuming and expensive. Herein, we performed Fourier‐transform infrared (FTIR) microscopy for evaluating the biochemical change on NSCLC (A549) cells after treatment. At levels that produced equivalent effects, Gefitinib dramatically induced cell apoptosis via impaired mitochondrial transmembrane potential. Whereas, Erlotinib had a slight effect on A549. Principal component analysis was performed to distinguish the effect of EGFR inhibitors on A549. FTIR spectra regions were divided into three regions: lipids (3000‐2800 cm^?1), proteins (1700‐1500 cm^?1) and carbohydrates and nuclei acids (1200‐1000 cm^?1). Biochemical changes can be evaluated by these spectral regions. This work may be a novel concept for utilizing FTIR spectroscopy for high‐throughput discriminative effects of a drug or compound and its derivatives on cells.     

Liver injury due to iron overload in thalassemia: histopathologic and ultrastructural studies

The livers of 30 cases of thalassemia (19/-thal/HbE, seven thal/HbH and four -thal major) were studied histopathologically and electron microscopically, in an effort to define the morphologic alterations due to iron overload. The results of light and electron microscopy were similar in most cases. Iron accumulation and fibrosis were the common features found in these patients, except that thal/HbH exhibited lesser hepatic damage. The degrees of iron deposition and fibrosis were found to be higher in splenectomized and cirrhotic than non-splenectomized and non-cirrhotic patients. The subcellular changes were swollen mitochondria, with the presence of an electron dense matrix and ruptured mitochondrial membrane. Proliferation of smooth endoplasmic reticulum (ER) and dilated rough ER was observed. Increases in lysosomal hemosiderin in hepatocytes and in Kupffer cells were demonstrated. The possible ways by which the iron compounds or free radicals mediated membrane damage are mentioned. The pattern of liver cell damage is similar to that of viral hepatitis.