Hedge Mustard (Sisymbrium officinale): Chemical Diversity of Volatiles and Their Antimicrobial Activity

Volatile compounds of hedge mustard (Sysimbrium officinale) have been investigated for the first time. Forthy‐two compounds were identified after hydrodistillation (without or upon autolysis) after gas chromatography and gas chromatography/mass spectrometry analyses. In addition, after decoction and hydrolysis of O‐glycosides, 18 volatile O‐aglycones were identified. In general, the main volatiles found in hydrodistillates were: isopropyl isothiocyanate (27.6–48.9%), 2‐methylpropanenitrile (0.5–18.8%), (Z)‐hex‐3‐en‐1‐ol (0.5–18.0%), sec‐butyl isothiocyanate (4.9–9.4%), (E)‐hex‐2‐enal (3.5–8.6%), (Z)‐hex‐2‐en‐1‐ol (0.3–8.4%), octanoic (0.5–8.6%) and dodecanoic acid (0–5.0%), 2‐methylbutanenitrile (0–4.6%), dibutyl phthalate (0–4.5%), and ethyl linolenate (0–3.6%). The main volatile O‐aglycones were: 2‐phenylethyl alcohol (21.5%), 6,7‐dehydro‐7,8‐dihydro‐3‐oxo‐α‐ionol (9.3%), eugenol (8.3%), benzyl alcohol (7.0%), ethyl vanillate (5.2%), 6‐(tert‐butyl)‐5‐methylphenol (5.1%), vanillin acetone (4.7%), ethyl 4‐hydroxybenzoate (4.3%), and 2‐hydroxy‐β‐ionone (3.8%). All hydrodistillates exhibited great potential of antibacterial activity against five Gram‐positive bacteria, nine ampicillin‐resistant Gram‐negative bacteria, and four fungi at a concentration of 500 μg/ml using the disc diffusion method.     

Proteolipid/DM-20 proteins bearing the paralytic tremor mutation in peripheral nerves and transfected Cos-7 cells

Paralytic tremor (Plp-pt) is a missense mutation of the myelin proteolipid gene (Plp) in rabbits. The myelin yield in the Plp-pt brain is reduced and the protein and lipid composition of central nervous system (CNS) myelin is abnormal. We studied the intracellular transport of the normal and Plp-pt mutant PLP and DM-20 in transiently transfected Cos-7 cells. While the mutant PLP accumulates in the rough endoplasmic reticulum and does not reach the plasma membrane, the spliced isoform of PLP, mutant DM-20, is normally transported to the cell surface and integrated into the membrane. Analysis of rabbit sciatic nerves revealed that concentration of peripheral nervous system (PNS) myelin proteins is normal in Plp-pt myelin. In the PNS like in the CNS, the level of Plp gene products is subnormal. But this does not affect myelination, in the PNS where PLP, present in low concentration, is not a structural component of compact myelin. The normal level of Plp gene expression in Schwann cells is low and these results suggest that, in the Plp-pt PNS, Schwann cell function is not affected by the deficiency in PLP and/or the impairment of intracellular PLP transport. Special issue dedicated to Dr Marion E. Smith.     

Inhibition of rat synaptic membrane Na⁺/K⁺-ATPase and ecto-nucleoside triphosphate diphosphohydrolases by 12-tungstosilicic and 12-tungstophosphoric acid

The in vitro influence of Keggin structure polyoxotungstates, 12-tungstosilicic acid, H(4)SiW(12)O(40) (WSiA) and 12-tungstophosphoric acid, H(3)PW(12)O(40) (WPA), and monomer Na(2)WO(4) × 2H(2)O on rat synaptic plasma membrane (SPM) Na(+)/K(+)-ATPase and E-NTPDase activity was studied, whereas the commercial porcine cerebral cortex Na(+)/K(+)-ATPase served as a reference. Dose-dependent Na(+)/K(+)-ATPase inhibition was obtained for all investigated compounds. Calculated IC(50) (10 min) values, in mol/l, for SPM/commercial Na(+)/K(+)-ATPase, were: 3.4 × 10(-6)/4.3 × 10(-6), 2.9 × 10(-6)/3.1 × 10(-6) and 1.3 × 10(-3)/1.5 × 10(-3) for WSiA, WPA and Na(2)WO(4) × 2H(2)O, respectively. In the case of E-NTPDase, increasing concentrations of WSiA and WPA induced its activity reduction, while Na(2)WO(4) × 2H(2)O did not noticeably affect the enzyme activity at all investigated concentrations (up to 1 × 10(-3)mol/l). IC(50) (10 min) values, obtained from the inhibition curves, were (in mol/l): 4.1 × 10(-6) for WSiA and 1.6 × 10(-6) for WPA. Monolacunary Keggin anion was found as the main active molecular species present under physiological conditions (in the enzyme assays, pH 7.4), for the both polyoxotungstates solutions (1 mmol/l), using Fourier transform infrared (FT-IR) and micro-Raman spectroscopy. Additionally, commercial porcine cerebral cortex Na(+)/K(+)-ATPase was exposed to the mixture of Na(2)WO(4) × 2H(2)O and WSiA at different concentrations. Additive inhibition effect was achieved for lower concentrations of Na(2)WO(4) × 2H(2)O/WSiA (≤ 1 × 10(-3)/4 × 10(-6) mol/l), while antagonistic effect was obtained for all higher concentrations of the inhibitors.     

Human immunodeficiency virus type 1 attachment,coreceptor, and fusion inhibitors are active against both direct and trans infection of primary cells

Inhibitors of human immunodeficiency virus type 1 attachment (CD4-immunoglobulin G subclass 2), CCR5 usage (PRO 140), and fusion (T-20) were tested on diverse primary cell types that represent the major targets both for infection in vivo and for the inhibition of trans infection of target cells by virus bound to dendritic cells. Although minor cell-type-dependent differences in potency were observed, each inhibitor was active on each cell type and trans infection was similarly vulnerable to inhibition at each stage of the fusion cascade.     

Growth retardation as well as spleen and thymus involution in latent TGF-beta binding protein (Ltbp)-3 null mice

The latent TGF-beta binding protein (LTBP)-3 is an extracellular matrix (ECM) protein that binds the small latent complex (SLC) of TGF-beta. Disruption of the Ltbp-3 gene by homologous recombination in mice yields mutant animals that display multiple skeletal abnormalities. In addition, these mice have retarded growth. On an inbred 129 SvEv background, half of the Ltbp-3 mutant mice die between 3 and 4 weeks after birth. These mice show severe involution of the thymus and spleen and a sharp reduction in the numbers of CD4/CD8 double positive T-cells in the thymus. The thymus and spleen defect is caused by elevated corticosterone levels in the serum and can be reversed by injection of aminoglutethimide (AMG), an inhibitor of steroid synthesis. This result indicates that the thymus and spleen defect is a secondary defect due to high corticosterone levels probably induced by stress of unknown etiology.     

Pentadecapeptide BPC 157 and its effects on a NSAID toxicity model: diclofenac-induced gastrointestinal, liver, and encephalopathy lesions

AimsWe attempted to fully antagonize the extensive toxicity caused by NSAIDs (using diclofenac as a prototype).Main methodsHerein, we used the stable gastric pentadecapeptide BPC 157 (GEPPPGKPADDAGLV, MW 1419), an anti-ulcer peptide shown to be efficient in inflammatory bowel disease clinical trials (PL 14736) and various wound treatments with no toxicity reported. This peptide was given to antagonize combined gastrointestinal, liver, and brain toxicity induced by diclofenac (12.5 mg/kg intraperitoneally, once daily for 3 days) in rats.Key findingsAlready considered a drug that can reverse the toxic side effects of NSAIDs, BPC 157 (10 μg/kg, 10 ng/kg) was strongly effective throughout the entire experiment when given (i) intraperitoneally immediately after diclofenac or (ii) per-orally in drinking water (0.16 μg/mL, 0.16 ng/mL). Without BPC 157 treatment, at 3 h following the last diclofenac challenge, we encountered a complex deleterious circuit of diclofenac toxicity characterized by severe gastric, intestinal and liver lesions, increased bilirubin, aspartate transaminase (AST), alanine transaminase (ALT) serum values, increased liver weight, prolonged sedation/unconsciousness (after any diclofenac challenge) and finally hepatic encephalopathy (brain edema particularly located in the cerebral cortex and cerebellum, more in white than in gray matter, damaged red neurons, particularly in the cerebral cortex and cerebellar nuclei, Purkinje cells and less commonly in the hippocampal neurons).SignificanceThe very extensive antagonization of diclofenac toxicity achieved with BPC 157 (μg-/ng-regimen, intraperitoneally, per-orally) may encourage its further use as a therapy to counteract diclofenac- and other NSAID-induced toxicity.     

Density- and Frequency-Dependent Selection at the Mdh-2 Locus in DROSOPHILA PSEUDOOBSCURA

We have studied differences in the number of Drosophila pseudoobscura produced in a culture when the flies differ with respect to two alleles (F and S) at the Mdh-2 locus, which codes for a malate dehydrogenase enzyme. The studies were done at low and at high density in two- and three-genotype combinations (S/S, F/F and S/F), with one-genotype cultures as controls.——Density affects the fitness of the Mdh-2 genotypes. Different genotypes are differently affected, and the genotype of the competitors also makes a difference on the fitness of a given genotype. When three genotypes are present in a culture, particularly at high density, intergenotypic competition is less intense than intragenotypic competition at several frequency combinations. That is, there is "overcompensation": the three genotypes together exploit the environmental resources better than one genotype alone.—The fitness of the genotypes is frequency dependent in both two-genotype and three-genotype combinations. An inverse relationship between frequency and fitness is observed at high density. This may lead to a stable polymorphism, because the fitness of a genotype increases as its frequency decreases.—Forty independent strains, sampled from a natural population, were used in the experiments. This ensures that more than 95% of the variation present in the genome in the natural population is also present is the experimental cultures. It also ensures that the genetic background of the Mdh-2 alleles is randomized in the same way as it is in nature. However, the possibility remains that Mdh-2 alleles in nature are nonrandomly associated with alleles at closely linked loci. If linkage disequilibrium is present in the experiments because it exists in nature, then the observed effects (such as frequency-dependent selection) would affect the Mdh-2 locus in nature as well.     

Job satisfaction among medical doctors in one of the countries in transition: experience from Croatia

Our aim was to explore and compare the job satisfaction between family physicians and hospital specialists in Split, Croatia. The survey was carried out in 2005 and 2006. A validated questionnaire was composed of two parts: 92 statements and questions about job satisfaction in the form of a Lickert scale (range 1-5) and eight questions concerning demographic issues. The questionnaire was completed and returned by 165 hospital specialists from the University Hospital and by 131 family physicians from the Split County. Response rate for family physicians was 39.81% and 41.46% for hospital specialists. Hospital doctors were divided in two groups: internal and surgical. There were no significant differences between family physicians and hospital specialists in total job satisfaction (F = 1.02; p = 0.41). Family physicians were more satisfied with their workplace conditions than internal medicine specialists (19.37 +/- 4.23 vs. 17.37 +/- 4.59; F = 5.93; p = 0.003), and less satisfied with the possibilities for postgraduate training than surgeons (5.27 +/- 1.90 vs. 6.59 +/- 2.07; F = 9.26; p < 0.001). Global job satisfaction was rather low but does not differ between the three medical groups. Disparities were observed in some segments (opportunity for further training and academic advancement, vacation, and salary). The reason for the family physician's relative satisfaction may be due to stable working conditions, independence in organizing work schedules and personal responsibility.     

New gold carbene complexes as candidate anticancer agents

Three structurally related gold(I) carbene complexes with bulky hydrophobic ligands i.e. 1–3 were investigated in solution for further consideration as candidate anticancer agents. Cytotoxic assays were subsequently conducted on bone marrow-derived preosteoclast cell line of human origin (FLG 29.1) and human colon cancer cells (HCT-116). A far greater cytotoxic activity was measured for compound 1 against HCT-116 cells compared to 2 and 3; conversely, all compounds were highly and similarly active against FLG 29.1 cells. Results obtained for the reaction of complexes 1 and 2 with RNase A documented the occurrence of a weak interaction with this model protein and the formation of a tiny amount of the corresponding adduct. Moreover, a certain reactivity of the complex 2 was also detected toward GSH. The general implications of the obtained results are discussed.     

In Vitro Antibacterial Activity of Cysteine Protease Inhibitor from Kiwifruit (Actinidia deliciosa)

The need for replacing traditional pesticides with alternative agents for the management of agricultural pathogens is rising worldwide. In this study, a cysteine proteinase inhibitor (CPI), 11 kDa in size, was purified from green kiwifruit to homogeneity. We examined the growth inhibition of three plant pathogenic Gram-negative bacterial strains by kiwi CPI and attempted to elucidate the potential mechanism of the growth inhibition. CPI influenced the growth of phytopathogenic bacteria Agrobacterium tumefaciens (76.2 % growth inhibition using 15 μM CPI), Burkholderia cepacia (75.6 % growth inhibition) and, to a lesser extent, Erwinia carotovora (44.4 % growth inhibition) by inhibiting proteinases that are excreted by these bacteria. Identification and characterization of natural plant defense molecules is the first step toward creation of improved methods for pest control based on naturally occurring molecules.