Antimycotic activities of selected plant flora,growing wild in Lebanon,against phytopathogenic fungi

Petroleum ether (PE) and methanolic extracts of nine wild plant species were tested in vitro for their antimycotic activity against eight phytopathogenic fungi. The efficacy of PE extracts against all pathogens tested was higher than that of methanolic extracts. Wild marjoram (Origanum syriacum) PE extract showed the highest and widest range of activity. It resulted in complete inhibition of mycelial growth of six of eight fungi tested and also gave nearly complete inhibition of spore germination of the six fungi included in the assay, namely, Botrytis cinerea, Alternaria solani, Penicillium sp., Cladosporium sp., Fusarium oxysporum f. sp. melonis, and Verticillium dahlia. The other plant extracts showed differential activities in the spore germination test, but none was highly active against mycelial growth. Inula viscosa and Mentha longifolia were highly effective (>88%) in spore germination tests against five of six fungi tested, whereas Centaurea pallescens, Cichorium intybus, Eryngium creticum, Salvia fruticosa, and Melia azedarach showed >95% inhibition of spore germination in at least two fungi. Foeniculum vulgare showed the least antimycotic activity. Fractionation followed by autobiography on TLC plates using Cladosporium sp. as a test organism showed that O. syriacum PE extracts contained three inhibition zones, and those of Inula viscosa and Cichorium intybus, two, whereas the PE extracts of the remaining plants showed each one inhibition zone. Some of the major compounds present in these inhibition zones were identified by GC-MS. The possibility for using these extracts, or their mixtures, to control plant diseases is discussed.     

Human-carnivore coexistence in a traditional rural landscape

Facilitating human-carnivore coexistence is a major conservation concern in human-dominated landscapes worldwide. Useful insights could be gained by studying and understanding the dynamics of human-carnivore coexistence in landscapes in which carnivores and humans have coexisted for a long time. We used a two-pronged approach combining ecological and social data to study coexistence of the brown bear (Ursus arctos) and humans in Transylvania, Romania. First, we surveyed 554 km of walking transects to estimate activity via a bear sign index, namely the proportion of anthills disturbed by bears, and used spatially explicit predictive models to test which biophysical and anthropogenic variables influenced bear activity. Second, we interviewed 86 shepherds and 359 villagers and community representatives to assess conflicts with bears and attitudes of shepherds towards bears. Our interdisciplinary study showed that bears and humans coexisted relatively peacefully despite occasional conflicts. Coexistence appeared to be facilitated by: (1) the availability of large forest blocks that are connected to the source population of bears in the Carpathian Mountains; (2) the use of traditional livestock management to minimize damage from bears; and (3) some tolerance among shepherds to occasional conflict with bears. In contrast, bear activity was unrelated to human settlements, and compensation for livestock losses did not influence people’s attitudes toward bears. Our study shows that coexistence of humans and carnivores is possible, even without direct economic incentives. A key challenge for settings with a discontinuous history of human-carnivore coexistence is to reinstate both practices and attitudes that facilitate coexistence.     

SPI-1-encoded type III secretion system of Salmonella enterica is required for the suppression of porcine alveolar macrophage cytokine expression

ABSTRACT: Genes localized at Salmonella pathogenicity island-1 (SPI-1) are involved in Salmonella enterica invasion of host non-professional phagocytes. Interestingly, in macrophages, SPI-1-encoded proteins, in addition to invasion, induce cell death via activation of caspase-1 which also cleaves proIL-1β and proIL-18, precursors of 2 proinflammatory cytokines. In this study we were therefore interested in whether SPI-1-encoded type III secretion system (T3SS) may influence proinflammatory response of macrophages. To test this hypothesis, we infected primary porcine alveolar macrophages with wild-type S. Typhimurium and S. Enteritidis and their isogenic SPI-1 deletion mutants. ΔSPI1 mutants of both serovars invaded approx. 5 times less efficiently than the wild-type strains and despite this, macrophages responded to the infection with ΔSPI1 mutants by increased expression of proinflammatory cytokines IL-1β, IL-8, TNFα, IL-23α and GM-CSF. Identical macrophage responses to that induced by the ΔSPI1 mutants were also observed to the infection with sipB but not the sipA mutant. The hilA mutant exhibited an intermediate phenotype between the ΔSPI1 mutant and the wild-type S. Enteritidis. Our results showed that the SPI-1-encoded T3SS is required not only for cell invasion but in macrophages also for the suppression of early proinflammatory cytokine expression.     

Adiponectin and IGF-1 are negative acute phase proteins in a dog model of acute endotoxaemia

The objective of this study was to evaluate the influence of an experimentally induced acute inflammation on serum adiponectin and insulin-like growth factor 1 (IGF-1) levels in the dog, and to compare their evolution with other well-established acute phase proteins (APPs) such as C-reactive protein (CRP), and haptoglobin (Hp). Therefore levels of adiponectin, IGF-1 and a profile of APPs were measured in healthy dogs after intravenous administration of E. coli LPS (0.02 mg/kg) and compared with dogs injected with saline solution (0.2 mL/kg). Adiponectin and IGF-1 were both decreased in response to endotoxins in the dog. Significant positive correlations were found between adiponectin and IGF-1 (r=0.31; p<0.05). Adiponectin had also a significant negative correlation with CRP (r=-0.39; p<0.05) and Hp (r=-0.27; p<0.05), whereas IGF-1 had significant negative correlation with CRP (r=-0.52; p<0.001). The results obtained in the present study indicate that adiponectin and IGF-1 behave as negative acute phase proteins after acute inflammatory stimulus in dogs.     

Effects of a single intraperitoneal administration of cadmium on femoral bone structure in male rats

Background

Exposure to cadmium (Cd) is considered a risk factor for various bone diseases in humans and experimental animals. This study investigated the acute effects of Cd on femoral bone structure of adult male rats after a single intraperitoneal administration.

Methods

Ten 4-month-old male Wistar rats were injected intraperitoneally with a single dose of 2 mg CdCl₂/kg body weight and killed 36 h after the Cd had been injected. Ten 4-month-old males served as a control group. Differences in body weight, femoral weight, femoral length and histological structure of the femur were evaluated between the two groups of rats. The unpaired Student''s t-test was used for establishment of statistical significance.

Results

A single intraperitoneal administration of Cd had no significant effect on the body weight, femoral weight or femoral length. On the other hand, histological changes were significant. Rats exposed to Cd had significantly higher values of area, perimeter, maximum and minimum diameters of the primary osteons'' vascular canals and Haversian canals. In contrast, a significant decrease in all variables of the secondary osteons was observed in these rats.

Conclusions

The results indicate that, as expected, a single intraperitoneal administration of 2 mg CdCl₂/kg body weight had no impact on macroscopic structure of rat''s femora; however, it affected the size of vascular canals of primary osteons, Haversian canals, and secondary osteons.     

Influence of the lipopolysaccharide structure of Salmonella enterica serovar Enteritidis on interactions with pig neutrophils

The key process for immune response development is the recognition of bacteria by the immune system of the host based on the sensing of pathogen-associated molecular patterns (PAMP). One of the most important PAMP is the lipopolysaccharide (LPS) molecule, a complex molecule present in the outer membrane of Gram negative bacteria. In this study we were interested in how different parts of the LPS of Salmonella enterica serovar Enteritidis are recognized by porcine neutrophils. To this aim, we constructed S. Enteritidis mutants with rfaL and rfaC genes disabled in the attachment of the O-antigen and in the synthesis of the inner oligosaccharide core of LPS, respectively. We found that in the absence of serum, both the rfa mutants associated with neutrophils and stimulated them for reactive oxygen species (ROS) production significantly more than the wild-type strain. Addition of polymyxin B, which neutralized lipid A, the endotoxic moiety of LPS, effectively decreased the association of the wild-type strain and the rfaC mutant with neutrophils, but not the rfaL mutant. This indicates that the oligosaccharide core newly exposed on the surface in the rfaL mutant, protected from interaction in the wild-type strain by the O-antigen but completely absent in the rfaC mutant, may represent a new ligand for porcine neutrophils that cannot be neutralized by polymyxin B.     

Short-term watering-distance and symmetry effects on root and shoot growth of bell pepper plantlets

Drip lines were located at distances ranging from 0 to 60 cm from one or both sides of a row of pepper plantlets, and we monitored the effects on their shoot development during 76 days from transplanting to full-size first fruits, on the final root system, and on the areal water and salt distributions in the upper 15-cm soil layer. The experiment was conducted in a greenhouse with a sandy soil, and excess fresh water (1.9 L d⁻¹ per plant) was applied via short daily irrigations. In addition, the effects of watering distance and symmetry on the potential water uptake rate were analyzed with a coupled-source-sink steady flow and uptake model. Initial faster shoot growth with the one-side system and short distances progressively changed to faster growth with the two-side system and longer watering distances, with the optimum at 30-40 cm. These temporal changes are attributed to temporal changes in the root uptake of irrigation water: small plants with small root systems benefit from the larger water supply to a smaller soil volume provided by the one-side system, whereas larger plants with greater water needs could extract more irrigation water when they developed larger, split root systems in the two-side irrigation. Balanced root systems and maximal shoot growth can be obtained by starting the irrigation with a line on each side, near the plants, and moving the lines after a short time.     

Replication of genome-wide association signals in UK samples reveals risk loci for type 2 diabetes

The molecular mechanisms involved in the development of type 2 diabetes are poorly understood. Starting from genome-wide genotype data for 1924 diabetic cases and 2938 population controls generated by the Wellcome Trust Case Control Consortium, we set out to detect replicated diabetes association signals through analysis of 3757 additional cases and 5346 controls and by integration of our findings with equivalent data from other international consortia. We detected diabetes susceptibility loci in and around the genes CDKAL1, CDKN2A/CDKN2B, and IGF2BP2 and confirmed the recently described associations at HHEX/IDE and SLC30A8. Our findings provide insight into the genetic architecture of type 2 diabetes, emphasizing the contribution of multiple variants of modest effect. The regions identified underscore the importance of pathways influencing pancreatic beta cell development and function in the etiology of type 2 diabetes.     

A common variant in the FTO gene is associated with body mass index and predisposes to childhood and adult obesity

Obesity is a serious international health problem that increases the risk of several common diseases. The genetic factors predisposing to obesity are poorly understood. A genome-wide search for type 2 diabetes-susceptibility genes identified a common variant in the FTO (fat mass and obesity associated) gene that predisposes to diabetes through an effect on body mass index (BMI). An additive association of the variant with BMI was replicated in 13 cohorts with 38,759 participants. The 16% of adults who are homozygous for the risk allele weighed about 3 kilograms more and had 1.67-fold increased odds of obesity when compared with those not inheriting a risk allele. This association was observed from age 7 years upward and reflects a specific increase in fat mass.