Lactobacillus rhamnosus GG conditioned media modulates acute reactive oxygen species and nitric oxide in J774 murine macrophages

Phagocytes such as macrophages are capable of detecting and killing pathogenic bacteria by producing reactive oxygen and nitrogen species. Formation of free radicals in macrophages may be regulated by probiotics or by factors released by probiotics but yet to be identified. Thus, studies were carried out to determine whether cell-free conditioned medium obtained from cultures of Lactobacillus rhamnosus GG (LGG-CM) regulate production of reactive oxygen species (ROS) and/or nitric oxide (NO) in macrophages. J774 macrophages in culture were loaded with either H₂DCFDA for monitoring ROS or with DAFFM-DA for NO detection. Free radical production was measured on a fluorescence microplate reader and changes were analysed by Cumulative sum (CuSum) calculations. Low concentration of LGG-CM (10% LGG-CM) or LPS did not cause any significant change in basal levels of ROS or NO production. In contrast, high concentration of LGG-CM (75% and 100%) significantly enhanced ROS generation but also significantly reduced NO level. These findings are novel and suggest for the first time that probiotics may release factors in culture which enhance ROS production and may additionally reduce deleterious effects associated with excessive nitrogen species by suppressing NO level. These events may account, in part, for the beneficial bactericidal and anti-inflammatory actions ascribed to probiotics and may be of clinical relevance.     

Optimising the duration of floating row cover period to minimise the incidence of tomato yellow leaf curl disease and maximise yield of tomato

The influence of polyester cover on tomato crops was evaluated to determine its effectiveness in reducing the incidence of tomato yellow leaf curl disease and on tomato yield. Uncovered plots were compared in a randomised block design with 14 treatments having different durations of cover. The identification of begomovirus was carried out by polymerase chain reaction, cloning and complete nucleotide sequencing of viruses from infected plants. Disease incidence was high in plots covered for less than 3 weeks with no significant differences among these treatments and those that were left uncovered. In the three treatments with the longest duration of cover, no disease was recorded but yield was significantly decreased. The optimum covering period was 6–7 weeks, providing protection against disease (10% incidence) and maintaining high yields (3 kg per plant). Floating row covers can play a major role in reducing begomovirus‐induced diseases by reducing exposure to whiteflies which transmit these viruses. The current work appears to be the first attempt to optimise the cover period by sequentially removing covers from crops to analyse the consequences in terms of crop biomass, yield and disease and to explore the interactions between these parameters.     

Enhancement of Bioavailability and Pharmacodynamic Effects of Thymoquinone Via Nanostructured Lipid Carrier (NLC) Formulation

Thymoquinone (TQ), obtained from black cumin (Nigella sativa), is a natural product with anti-oxidant, anti-inflammatory, and hepatoprotective effects but unfortunately with poor bioavailability. Aiming to improve its poor oral bioavailability, TQ-loaded nanostructured lipid carriers (NLCs) were prepared by high-speed homogenization followed by ultrasonication and evaluated in vitro. Bioavailability and pharmacodynamic studies were also performed. The resultant NLCs showed poor physical homogeneity in Compritol 888 ATO Pluronic F127 system which consequently produced larger particle size and polydispersity index, smaller zeta potential values, and lower short-term (30 days) physical stability than other systems. Encapsulation efficiency percentage (EE%) lied between 84.6?±?5% and 96.2?±?1.6%. TQ AUC_0–t values were higher in animals treated with NLCs, with a relative bioavailability of 2.03- and 3.97-fold (for F9 and F12, respectively) higher than TQ suspension, indicating bioavailability enhancement by NLC formulation. Hepatoprotective effects of F12 showed significant (P?<?0.05) decrease in both serum alanine amino transferase and aspartate amino transferase to reach 305.0?±?24.88 and 304.7?±?23.55 U/ml, respectively, when compared with untreated toxic group. Anti-oxidant efficacy of F12 showed significant (P?<?0.05) decline of malondialdehyde and elevation of reduced glutatione. This improvement was also confirmed histopathologically.     

Generalized and species-specific prediction models for aboveground biomass in semi-steppe rangelands

Aims The accurate estimation of aboveground biomass in vegetation is critical for global carbon accounting. Regression models provide an easy estimation of aboveground biomass at large spatial and temporal scales. Yet, only few prediction models are available for aboveground biomass in rangelands, as compared with forests. In addition to the development of prediction models, we tested whether such prediction models vary with plant growth forms and life spans, and with the inclusion of site and/or quadrat-specific factors.     

Population genetic structure and connectivity of the seagrass Thalassia hemprichii in the Western Indian Ocean is influenced by predominant ocean currents

This study is the first large‐scale genetic population study of a widespread climax species of seagrass, Thalassia hemprichii, in the Western Indian Ocean (WIO). The aim was to understand genetic population structure and connectivity of T. hemprichii in relation to hydrodynamic features. We genotyped 205 individual seagrass shoots from 11 sites across the WIO, spanning over a distance of ~2,700 km, with twelve microsatellite markers. Seagrass shoots were sampled in Kenya, Tanzania (mainland and Zanzibar), Mozambique, and Madagascar: 4–26°S and 33–48°E. We assessed clonality and visualized genetic diversity and genetic population differentiation. We used Bayesian clustering approaches (TESS) to trace spatial ancestry of populations and used directional migration rates (DivMigrate) to identify sources of gene flow. We identified four genetically differentiated groups: (a) samples from the Zanzibar channel; (b) Mozambique; (c) Madagascar; and (d) the east coast of Zanzibar and Kenya. Significant pairwise population genetic differentiation was found among many sites. Isolation by distance was detected for the estimated magnitude of divergence (D_EST), but the three predominant ocean current systems (i.e., East African Coastal Current, North East Madagascar Current, and the South Equatorial Current) also determine genetic connectivity and genetic structure. Directional migration rates indicate that Madagascar acts as an important source population. Overall, clonality was moderate to high with large differences among sampling sites, indicating relatively low, but spatially variable sexual reproduction rates. The strongest genetic break was identified for three sites in the Zanzibar channel. Although isolation by distance is present, this study suggests that the three regionally predominant ocean current systems (i.e., East African Coastal Current, North East Madagascar Current, and the South Equatorial Current) rather than distance determine genetic connectivity and structure of T. hemprichii in the WIO. If the goal is to maintain genetic connectivity of T. hemprichii within the WIO, conservation planning and implementation of marine protection should be considered at the regional scale—across national borders.     

Reduced-intensity stem cell transplantation for hematological malignancies: current status and the future

Reduced-intensity stem cell transplantation (RIST) has opened a new era for hematopoietic stem cell transplantation (HSCT). It was developed based on the knowledge that graft-versus-tumor (GVT) effect is the main anti-tumor effect in allogeneic HSCT. Because RIST is associated with less morbidity and mortality, it can be applied to many patients who could not undergo conventional HSCT. Experiences in the last decade clarified many issues related to RIST. For example, graft-versus-host disease (GVHD) in RIST may differ in character compared to conventional HSCT. Also, it is now known that intensity of conditioning is important in disease control, and the optimal regimens may be different for each disease or for each disease status. There are still many unsolved questions, and large prospective randomized trials are necessary to resolve these.