Adipose tissue. Pathophysiology, distribution, sex differences and the role in inflammation and cancerogenesis

The role of adipose tissue is energy storage, but there is increasing evidence that adipocytes and adipokines are involved in metabolic and inflammatory processes. This paper reviews the pathophysiology of different adipose tissue depots. Interrelationships between sex hormones, adipose tissue and risk factors are also discussed. Present study focuses on the effects of adipokines on immune system and on the mechanisms relating adiposity to cancer risk.     

Effect of Mating Frequency on Female Fitness in Caloglyphus Berlesei (Astigmata: Acaridae)

We studied the effect of mating frequency on female longevity and fecundity in the mite Caloglyphus berlesei. We tested the hypothesis that high promiscuity is selected for in this species because females receive nutrients during copulation. Females were constantly exposed to either one or four males and fed either a standard or poor diet. The prediction that frequent mating benefits females was not confirmed. On the contrary, females kept with four males had significantly lower longevity on both diets and on the standard diet they also had decreased fecundity compared to females exposed to one male. On the poor diet the number of males had no significant effect on fecundity. Thus, increased mating frequency had a detrimental effect on female fitness.     

Acute stress is detrimental to heart regeneration in zebrafish

Psychological stress is one of the factors associated with human cardiovascular disease. Here, we demonstrate that acute perceived stress impairs the natural capacity of heart regeneration in zebrafish. Beside physical and chemical disturbances, intermittent crowding triggered an increase in cortisol secretion and blocked the replacement of fibrotic tissue with new myocardium. Pharmacological simulation of stress by pulse treatment with dexamethasone/adrenaline reproduced the regeneration failure, while inhibition of the stress response with anxiolytic drugs partially rescued the regenerative process. Impaired heart regeneration in stressed animals was associated with a reduced cardiomyocyte proliferation and with the downregulation of several genes, including igfbp1b, a modulator of IGF signalling. Notably, daily stress induced a decrease in Igf1r phosphorylation. As cardiomyocyte proliferation was decreased in response to IGF-1 receptor inhibition, we propose that the stress-induced cardiac regenerative failure is partially caused by the attenuation of IGF signalling. These findings indicate that the natural regenerative ability of the zebrafish heart is vulnerable to the systemic paracrine stress response.     

The role of aminoglycoside--modifying enzymes in resistance of Gram-negative rods

The aim of the study was to evaluate the aminoglycoside resistance of Gram-negative bacilli isolated from patients. To the examination 35 strains of Enterobacteriaceae and 18 of non-fermentative bacteria were included. Resistance to aminoglycosides (gentamicin (G), netilmicin (Nt), tobramycin (T), amikacin (A), kanamycin (K), neomycin (N)) was established by disk diffusion method. Interpretation of enzymatic mechanisms was performed by Livermore. The most common enzymes AAC(6')I were found in Enterobacteriaceae group (mostly in E. cloaceae and P. mirabilis) and AAC(3') and in non-fermentative bacteria: AAC(6')I in P. aeruginosa and APH(3')VI and AAC(3')I in A. baumanii. The most frequent phenotype was resistance to six antibiotics (G, Nt, T, A, K, N) Resistance rates were high for gentamicin (>70 %) in both groups and amikacin (88,89 %) in non-fermentatives.     

Physiological and antioxidant responses of two accessions of Arabidopsis thaliana in different light and temperature conditions

During their lifetime, plants need to adapt to a changing environment, including light and temperature. To understand how these factors influence plant growth, we investigated the physiological and antioxidant responses of two Arabidopsis accessions, Shahdara (Sha) from the Shahdara valley (Tajikistan, Central Asia) in a mountainous area and Lovvik‐5 (Lov‐5) from northern Sweden to different light and temperature conditions. These accessions originate from different latitudes and have different life strategies, both of which are known to be influenced by light and temperature. We showed that both accessions grew better in high‐light and at a lower temperature (16°C) than in low light and at 23°C. Interestingly, Sha had a lower chlorophyll content but more efficient non‐photochemical quenching than Lov‐5. Sha, also showed a higher expression of vitamin E biosynthetic genes. We did not observe any difference in the antioxidant prenyllipid level under these conditions. Our results suggest that the mechanisms that keep the plastoquinone (PQ)‐pool in more oxidized state could play a role in the adaptation of these accessions to their local climatic conditions.     

Cyclodextrin production and genetic characterization of cyclodextrin glucanotranferase of <Emphasis Type="Italic">Paenibacillus graminis</Emphasis>

Paenibacillus graminis strains were described recently as cyclodextrin (CD) producers. Cyclodextrins are produced by cyclodextrin glucanotransferase (CGTase) which has not been characterized in P. graminis. Similar amounts of α- and β-CDs were produced by P. graminis (MC22.13) and P. macerans (LMD24.10^T). Primers were designed to sequence the gene encoding CGTase from P. graminis. A phylogenetic tree was constructed and P. graminis CGTase protein showed to be closer (79.4% protein identity) to P. macerans |P31835|. Hybridization studies suggested that the gene encoding CGTase is located in different positions in the genomes of P. macerans and P. graminis.     

Cellulolytic enzymes for the hydrolysis of leached beet cosette

Summary Cellulolytic fungi were isolated from rotting leaves and tested for extra-cellular cellulase activities (CMCase, avicelase, cellobiase and xylanase). The effect of the proportion of the enzyme activities on the rate of degradation of leached beet cosette was observed using a range of supernatant fluids in appropriate combinations. At low cosette concentrations (1.5–3.0 g/l), avicelase and cellobiase were the rate limiting enzymes; avicelase in the initial stages of reaction and cellobiase after 6–8 hours, when cellobiose inhibition becomes important. A ratio of celiobiase to avicelase of approx 2.0 was established as appropriate. At higher substrate concentrations (10 g/l, 40 g/l) the best cellobiase to avicelase ratio was maintained and up to 40% hydrolysis was obtained in the 10 g/l incubation with 10 Uav/l and 20 Ucellob/l. At 100 g/l cosette concentration, substrate inhibition was observed.     

Intergeneric relationships ofLolium,Festuca, andVulpia (Poaceae) and their phylogeny

Morphological and seed protein analyses of 26 species of the generaLolium, Festuca andVulpia confirmed their close systematic affinities. Six inflorescence characters readily differentiatedFestuca fromLolium. Protein similarities betweenFestuca of sect.Bovinae and cross-pollinated species ofLolium, coupled with cytogenetic and crossability data, substantiate that they should be united into one genus.Vulpia had phenetic similarities with sect.Scariosae, Montanae andOvinae ofFestuca. Lolium, Festuca, andVulpia are most likely derived from a common ancestral form which was close toFestuca pratensis andLolium perenne.     

Molecular Characterization of Subtype H11N9 Avian Influenza Virus Isolated from Shorebirds in Brazil

Migratory aquatic birds play an important role in the maintenance and spread of avian influenza viruses (AIV). Many species of aquatic migratory birds tend to use similar migration routes, also known as flyways, which serve as important circuits for the dissemination of AIV. In recent years there has been extensive surveillance of the virus in aquatic birds in the Northern Hemisphere; however in contrast only a few studies have been attempted to detect AIV in wild birds in South America. There are major flyways connecting South America to Central and North America, whereas avian migration routes between South America and the remaining continents are uncommon. As a result, it has been hypothesized that South American AIV strains would be most closely related to the strains from North America than to those from other regions in the world. We characterized the full genome of three AIV subtype H11N9 isolates obtained from ruddy turnstones (Arenaria interpres) on the Amazon coast of Brazil. For all gene segments, all three strains consistently clustered together within evolutionary lineages of AIV that had been previously described from aquatic birds in North America. In particular, the H11N9 isolates were remarkably closely related to AIV strains from shorebirds sampled at the Delaware Bay region, on the Northeastern coast of the USA, more than 5000 km away from where the isolates were retrieved. Additionally, there was also evidence of genetic similarity to AIV strains from ducks and teals from interior USA and Canada. These findings corroborate that migratory flyways of aquatic birds play an important role in determining the genetic structure of AIV in the Western hemisphere, with a strong epidemiological connectivity between North and South America.