Do latitudinal and bioclimatic gradients drive parasitism in Odonata?

Prevalence of parasites in wild animals may follow ecogeographic patterns, under the influence of climatic factors and macroecological features. One of the largest scale biological patterns on Earth is the latitudinal diversity gradient; however, latitudinal gradients may also exist regarding the frequency of interspecific interactions such as the prevalence of parasitism in host populations. Dragonflies and damselflies (order Odonata) are hosts of a wide range of ecto- and endoparasites, interactions that can be affected by environmental factors that shape their occurrence and distribution, such as climatic variation, ultraviolet radiation and vegetation structure. Here, we retrieved data from the literature on parasites of Odonata, represented by 90 populations infected by ectoparasites (water mites) and 117 populations infected by endoparasites (intestinal gregarines). To test whether there is a latitudinal and bioclimatic gradient in the prevalence of water mites and gregarines parasitizing Odonata, we applied Bayesian phylogenetic comparative models. We found that prevalence of ectoparasites was partially associated with latitude, showing the opposite pattern from our expectations – prevalence was reduced at lower latitudes. Prevalence of endoparasites was not affected by latitude. While prevalence of water mites was also positively associated with vegetation biomass and climatic stability, we found no evidence of the effect of bioclimatic variables on the prevalence of gregarines. Our study suggests that infection by ectoparasites of dragonflies and damselflies is driven by latitudinal and bioclimatic variables. We add evidence of the role of global-scale biological patterns in shaping biodiversity, suggesting that parasitic organisms may prove reliable sources of information about climate change and its impact on ecological interactions.     

Resident peritoneal NK cells

In this study, we describe a new population of NK cells that reside in the normal, uninflamed peritoneal cavity. Phenotypically, they share some similarities with the small population of CD49b(-), CD27(+) immature splenic NK cells, as well as liver NK cells, but they differ in their expression of CD62L, TRAIL, and EOMES. Functionally, the peritoneal NK cells resemble the immature splenic NK cells in their production of IFN-γ, GM-CSF, and TNF-α and in the killing of YAC-1 target cells. We also found that the peritoneum induces different behavior in mature and immature splenic NK cells. When transferred i.v. into RAGγc knockout mice, both populations undergo homeostatic proliferation in the spleen, but only the immature splenic NK cells are able to reach the peritoneum. When transferred directly into the peritoneum, the mature NK cells survive but do not divide, whereas the immature NK cells proliferate profusely. These data suggest that the peritoneum is not only home to a new subset of tissue-resident NK cells, but that it differentially regulates the migration and homeostatic proliferation of immature versus mature NK cells.     

Antiproliferative effects of Tubi-bee propolis in glioblastoma cell lines

Propolis is a resin formed by a complex chemical composition of substances that bees collect from plants. Since ancient times, propolis has been used in folk medicine, due to its biological properties, that include antimicrobial, anti-inflammatory, antitumoral and immunomodulatory activities. Glioblastoma is the most common human brain tumor. Despite the improvements in GBM standard treatment, patients' prognosis is still very poor. The aim of this work was to evaluate in vitro the Tubi-bee propolis effects on human glioblastoma (U251 and U343) and fibroblast (MRC-5) cell lines. Proliferation, clonogenic capacity and apoptosis were analyzed after treatment with 1 mg/mL and 2 mg/mL propolis concentrations for different time periods. Additionally, glioblastoma cell lines were submitted to treatment with propolis combined with temozolomide (TMZ). Data showed an antiproliferative effect of tubi-bee propolis against glioblastoma and fibroblast cell lines. Combination of propolis with TMZ had a synergic anti-proliferative effect. Moreover, propolis caused decrease in colony formation in glioblastoma cell lines. Propolis treatment had no effects on apoptosis, demonstrating a cytostatic action. Further investigations are needed to elucidate the molecular mechanism of the antitumor effect of propolis, and the study of its individual components may reveal specific molecules with antiproliferative capacity.     

Concurrent outbreak of norovirus genotype I and enterotoxigenic Escherichia coli on a U.S. Navy ship following a visit to Lima, Peru

An outbreak of norovirus (NoV) genotype I and Enterotoxigenic Escherichia coli (ETEC) occurred among US Navy Ship personnel following a visit to Lima, Peru, in June 2008. Visiting a specific area in Lima was significantly associated with illness. While ETEC and NoV are commonly recognized as causative agents of outbreaks, co-circulation of both pathogens has been rarely observed in shipboard outbreaks.     

TRAIL up-regulation must be accompanied by a reciprocal PKCε down-regulation during differentiation of colonic epithelial cell: implications for colorectal cancer cell differentiation

PKC isoenzymes play central roles in various cellular signalling pathways, participating in a variety of protein phosphorylation cascades that regulate/modulate cellular structure and gene expression. It has been firmly established that several isoforms of PKC have a role in the regulation of tumor necrosis factor-related apoptosis inducing ligand (TRAIL) activity. Our interest in probing the role of the epsilon isoform of PKC in the colonic cell differentiation stems from the discovery that PKCε and TRAIL are involved in the differentiation of other cell types like hematopoietic stem cells. Although the role of PKCε and TRAIL in the gastrointestinal system is unclear, it has been observed that PKCε has oncogenic activity in colon epithelial cells (CEC), while TRAIL increases the death of intestinal epithelial cells during inflammation. Here we demonstrate a reciprocal expression of PKCε and TRAIL in human colon mucosa: CECs at the bottom of the colonic crypts show high levels of PKCε, being negative for TRAIL expression. On the contrary, luminal CECs are positive for TRAIL, while negative for PKCε. Indeed, TRAIL- and butyrate-induced differentiation of the human colorectal cancer cell line HT29 requires the decrease of PKCε expression, whose absence in turn increases cell sensitivity to TRAIL-induced apoptosis. Moreover, TRAIL preferentially promotes HT29 differentiation into goblet cells. Taken together, this data demonstrate that TRAIL and PKCε must be reciprocally regulated to ensure physiological CEC differentiation starting from the stem cell pool, and that the down-regulation of PKCε is however critical for the differentiation and apoptosis of cancer cells.     

Preconditioning with a Novel Metallopharmaceutical NO Donor in Anesthetized Rats Subjected to Brain Ischemia/Reperfusion

Rut-bpy is a novel nitrosyl–ruthenium complex releasing NO into the vascular system. We evaluated the effect of Rut-bpy (100 mg/kg) on a rat model of brain stroke. Forty rats were assigned to four groups (Saline solution [SS], Rut-bpy, SS+ischemia–reperfusion [SS+I/R] and Rut-bpy+ischemia–reperfusion [Rut-bpy+I/R]) with their mean arterial pressure (MAP) continuously monitored. The groups were submitted (SS+I/R and Rut-bpy+I/R) or not (SS and Rut-bpy) to incomplete global brain ischemia by occlusion of the common bilateral carotid arteries during 30 min followed by reperfusion for further 60 min. Thirty minutes before ischemia, rats were treated pairwise by intraperitoneal injection of saline solution or Rut-bpy. At the end of experiments, brain was removed for triphenyltetrazolium chloride staining in order to quantify the total ischemic area. In a subset of rats, hippocampus was obtained for histopathology scoring, nitrate and nitrite measurements, immunostaining and western blotting of the nuclear factor- κB (NF-κB). Rut-bpy pre-treatment decreased MAP variations during the transition from brain ischemia to reperfusion and decreased the fractional injury area. Rut-bpy pre-treatment reduced NF-κB hippocampal immunostaining and protein expression with improved histopathology scoring as compared to the untreated operated control. In conclusion, Rut-bpy improved the total brain infarction area and hippocampal neuronal viability in part by inhibiting NF-κB signaling and helped to stabilize the blood pressure during the transition from ischemia to reperfusion.     

Nitric Oxide and Brazilian Propolis Combined Accelerates Tissue Repair by Modulating Cell Migration,Cytokine Production and Collagen Deposition in Experimental Leishmaniasis

The fact that drugs currently used in the treatment of Leishmania are highly toxic and associated with acquired resistance has promoted the search for new therapies for treating American tegumentary leishmaniasis (ATL). In this study, BALB/c mice were injected in the hind paw with Leishmania (Leishmania) amazonensis and subsequently treated with a combination of nitric oxide (NO) donor (cis-[Ru(bpy) ₂imN(NO)](PF₆)₃) (Ru-NO), given by intraperitoneal injection, and oral Brazilian propolis for 30 days. Ru-NO reached the center of the lesion and increased the NO level in the injured hind paw without lesion exacerbation. Histological and immunological parameters of chronic inflammation showed that this combined treatment increased the efficacy of macrophages, determined by the decrease in the number of parasitized cells, leading to reduced expression of proinflammatory and tissue damage markers. In addition, these drugs in combination fostered wound healing, enhanced the number of fibroblasts, pro-healing cytokines and induced collagen synthesis at the lesion site. Overall, our findings suggest that the combination of the NO donor Ru-NO and Brazilian propolis alleviates experimental ATL lesions, highlighting a new therapeutic option that can be considered for further in vivo investigations as a candidate for the treatment of cutaneous leishmaniasis.     

Vitamin D and overall mortality

Vitamin D is a steroid molecule, mainly produced in the skin that regulates the expression of a large number of genes. Several meta‐analyses of epidemiological studies support the evidence that low vitamin D serum level, which is highly prevalent worldwide, could be a ‘new’ risk factor for many chronic diseases including cancer, and for all‐cause mortality. A meta‐analysis in healthy subjects suggested that current doses of vitamin D supplements could be associated with decrease in total mortality rates. However, these associations are insufficient to establish causality between vitamin D and all‐cause mortality. Furthermore, long‐term health effects of high doses of vitamin D, that is, prolonged supplementation and association with different baseline vitamin D levels, remain to be investigated. Several trials are ongoing but population‐based, placebo‐controlled randomized trials with total mortality as the main endpoint should be planned to confirm a real beneficial effect of vitamin D for non‐skeletal diseases and to prove causality.     

Green Chromatographic Methods and in Vitro Pharmacological Analysis of Varronia curassavica Leaf Derivatives

Varronia curassavica displays anti-inflammatory, antiulcerogenic, and antioxidant activities. Herein, we employed new UHPLC –UV green chromatographic methods for the analysis of in vitro antioxidant and anti-inflammatory activities of V. curassavica and its embryotoxicity in Zebrafish. Cordialin A, brickellin, and artemetin were purified from the ethanol (EtOH) extract of V. Curassavica leaves and identified using spectrometric techniques. In line with Green Analytical Chemistry principles, the proposed UHPLC methods involve the use of ethanol as organic modifier with low mobile phase consumption, and without sample pretreatment (OLE-UHPLC-UV). The application of the Agree and HPLC-EAT tools for greenness assessment yielded this pattern: HPLC-UV (reference)<UHPLC-UV<OLE-UHPLC-UV. Zebrafish assay results showed that 70 % EtOH extract of V. Curassavica leaves exhibited lower toxicity compared to 100 % EtOH extract, with LC₅₀ of 164.3 and 122.9 μg/mL, respectively, in 24 h post fertilization. Some embryos exhibited malformation phenotypes in the heart, somites, and eyes, mainly in higher extract concentrations. Extracts and brickellin exhibited higher antioxidant activity in the DPPH⋅ assay, while brickellin+artemetin displayed higher antioxidant activity compared to the extracts and isolated flavones in the O₂⋅⁻ and HOCl/OCl⁻ scavenging assays. Cordialin A and brickellin exhibited low COX-1, COX-2, and phospholipase A₂ inhibition.