Effect of visible light on superoxide dismutase (SOD) activity in the red alga Gracilariopsis tenuifrons (Gracilariales, Rhodophyta)

Superoxide dismutase (SOD) was studied in the agarophyte Gracilariopsis tenuifrons. Similar SOD activity (130 ± 9U mg^-1) was observed in material from different regions of SouthAmerica, from different phases of the life cycle (gametophytes andtetrasporophytes), and from apical and basal sections of the thallus.In alga grown under a light-dark cycle, SOD activity in samples takenat different times exhibited a diurnal rhythm. The activity measured duringthe day phase was twice as much as during the night phase. This rhythm didnot persist under constant light, indicating light regulation of SOD activity.SOD activity was tested in algae submitted to different light intensities anddifferent wavelengths. It increased with the light intensity. The blue lightwavelength exerted a greater induction of SOD activity than other specificwavelengths.     

Harder,better, faster,stronger: Weapon size is more sexually dimorphic than weapon biomechanical components in two freshwater anomuran species

Sexual selection influences the evolution of morphological traits that increase the likelihood of monopolizing scarce resources. When such traits are used during contests, they are termed weapons. Given that resources are typically linked to monopolizing mating partners, theory expects only males to bear weapons. In some species, however, females also bear weapons, although typically smaller than male weapons. Understanding why females bear smaller weapons can thus help us understand the selective pressures behind weapon evolution. However, most of our knowledge comes from studies on weapon size, while the biomechanics of weapons, such as the size of the muscles, efficiency, and shape are seldom studied. Our goal was to test if the theoretical expectations for weapon size sexual dimorphism also occur for weapon biomechanics using two aeglid crab species. Males of both species had larger claws which were also stronger than female claws. Male claws were also more efficient than females' claws (although we used only one species in this analysis). For weapon shape, though, only one species differed in the mean claw shape. Regarding scaling differences, in both species, male claws had higher size scaling than females, while only one species had a higher shape scaling. However, male weapons did not have higher scaling regarding strength and efficiency than females. Thus, males apparently allocate more resources in weapons than females, but once allocated, muscle and efficiency follow a similar developmental pathway in both sexes. Taken together, our results show that sexual dimorphism in weapons involves more than differences in size. Shape differences are especially intriguing because we cannot fully understand its causes. Yet, we highlight that such subtle differences can only be detected by measuring and analysing weapon shape and biomechanical components. Only then we might better understand how weapons are forged.     

Prime–Boost with Mycobacterium smegmatis Recombinant Vaccine Improves Protection in Mice Infected with Mycobacterium tuberculosis

The development of a new vaccine as a substitute for Bacillus Calmette–Guerin or to improve its efficacy is one of the many World Health Organization goals to control tuberculosis. Mycobacterial vectors have been used successfully in the development of vaccines against tuberculosis. To enhance the potential utility of Mycobacterium smegmatis as a vaccine, it was transformed with a recombinant plasmid containing the partial sequences of the genes Ag85c, MPT51, and HspX (CMX) from M. tuberculosis. The newly generated recombinant strain mc²-CMX was tested in a murine model of infection. The recombinant vaccine induced specific IgG1 or IgG2a responses to CMX. CD4⁺ and CD8⁺ T cells from the lungs and spleen responded ex vivo to CMX, producing IFN-γ, IL17, TNF-α, and IL2. The vaccine thus induced a significant immune response in mice. Mice vaccinated with mc²-CMX and challenged with M. tuberculosis showed better protection than mice immunized with wild-type M. smegmatis or BCG. To increase the safety and immunogenicity of the CMX antigens, we used a recombinant strain of M. smegmatis, IKE (immune killing evasion), to express CMX. The recombinant vaccine IKE-CMX induced a better protective response than mc²-CMX. The data presented here suggest that the expression of CMX antigens improves the immune response and the protection induced in mice when M. smegmatis is used as vaccine against tuberculosis.     

Nesting biology of three Megachile (Hymenoptera: Megachilidae) species from Eastern Amazonia,Brazil

Megachile Latreille is a conspicuous genus of solitary bees distributed worldwide. However, the biology of tropical species is still little known. We present data on biology of Megachile brasiliensis Data Torre, Megachile sejuncta Cockerell and Megachile stilbonotaspis Moure found in two remnants of eastern Amazonian forest in northeastern Brazil. The study was conducted using the trap-nest methodology in two different areas during four periods. We collected a total of 24 nests of M. brasiliensis, 26 of M. sejuncta and 28 of M. stilbonotaspis. The differential abundance of collected nests may reflect the population size in each sampled place. The nesting activity was concentrated mainly between July and January and species presented a multivoltine pattern, except for M. sejuncta, which was partly univoltine. Assessed pollen use showed a predominant use of Attalea sp. (Arecaceae) and, for M. stilbonotaspis, Tylesia sp. and Lepidaploa sp. (Asteraceae). Babassu is a very common palm in the studied areas and the studied species seem to have a strong link with it. We also reported change of pollen use by M. sejuncta, probably due to competition with M. brasiliensis, which may have influenced the biased sex ratio observed in M. sejuncta toward males. Parasites reported here were also recorded for other Megachile species, such as Coelioxys, Brachymeria, Meloidae and Pyralidae species. Mites were observed in association with M. stilbonotaspis. The data presented here set up a background that encourages new studies on the ecology of these three Amazonian species, providing tools for proper biodiversity management and conservation.     

Glioprotective Effects of Lingonberry Extract Against Altered Cellular Viability,Acetylcholinesterase Activity,and Oxidative Stress in Lipopolysaccharide-Treated Astrocytes

Altered astrocytic function is a contributing factor to the development of neurological diseases and neurodegeneration. Berry fruits exert neuroprotective effects by modulating pathways involved in inflammation, neurotransmission, and oxidative stress. The aim of this study was to examine the effects of the lingonberry extract on cellular viability and oxidative stress in astrocytes exposed to lipopolysaccharide (LPS). In the reversal protocol, primary astrocytic cultures were first exposed to 1 µg/mL LPS for 3 h and subsequently treated with lingonberry extract (10, 30, 50, and 100 μg/mL) for 24 and 48 h. In the prevention protocol, exposure to the lingonberry extract was performed before treatment with LPS. In both reversal and prevention protocols, the lingonberry extracts, from 10 to 100 μg/mL, attenuated LPS-induced increase in reactive oxygen species (around 55 and 45%, respectively, P?<?0.01), nitrite levels (around 50 and 45%, respectively, P?<?0.05), and acetylcholinesterase activity (around 45 and 60%, respectively, P?<?0.05) in astrocytic cultures at 24 and 48 h. Also, in both reversal and prevention protocols, the lingonberry extract also prevented and reversed the LPS-induced decreased cellular viability (around 45 and 90%, respectively, P?<?0.05), thiol content (around 55 and 70%, respectively, P?<?0.05), and superoxide dismutase activity (around 50 and 145%, respectively, P?<?0.05), in astrocytes at both 24 and 48 h. Our findings suggested that the lingonberry extract exerted a glioprotective effect through an anti-oxidative mechanism against LPS-induced astrocytic damage.     

Impact of short-term temperature challenges on the larvicidal activities of the entomopathogenic watermold Leptolegnia chapmanii against Aedes aegypti, and development on infected dead larvae

The oomycete Leptolegnia chapmanii is among the most promising entomopathogens for biological control of Aedes aegypti. This mosquito vector breeds in small water collections, where this aquatic watermold pathogen can face short-term scenarios of challenging high or low temperatures during changing ambient conditions, but it is yet not well understood how extreme temperatures might affect the virulence and recycling capacities of this pathogen. We tested the effect of short-term exposure of encysted L. chapmanii zoospores (cysts) on A. aegypti larvae killed after infection by this pathogen to stressful low or high temperatures on virulence and production of cysts and oogonia, respectively. Cysts were exposed to temperature regimes between ?12 °C and 40 °C for 4, 6 or 8 h, and then their infectivity was tested against third instar larvae (L3) at 25 °C; in addition, production of cysts and oogonia on L3 killed by infection exposed to the same temperature regimes as well as their larvicidal activity were monitored. Virulence of cysts to larvae and the degree of zoosporogenesis on dead larvae under laboratory conditions were highest at 25 °C but were hampered or even blocked after 4 up to 8 h exposure of cysts or dead larvae at both the highest (35 °C and 40 °C) and the lowest (?12 °C) temperatures followed by subsequent incubation at 25 °C. The virulence of cysts was less affected by accelerated than by slow thawing from the frozen state. The production of oogonia on dead larvae was stimulated by short-term exposure to freezing temperatures (?12 °C and 0 °C) or cool temperatures (5 °C and 10 °C) but was not detected at higher temperatures (25 °C–40 °C). These findings emphasize the susceptibility of L. chapmanii to short-term temperature stresses and underscore its interest as an agent for biocontrol of mosquitoes in the tropics and subtropics, especially A. aegypti, that breed preferentially in small volumes of water that are generally protected from direct sunlight.     

Hyperglycemia and aberrant <Emphasis Type="Italic">O-GlcNAc</Emphasis>ylation: contributions to tumor progression

A number of cancer types have shown an increased prevalence and a higher mortality rate in patients with hyperglycemic associated pathologies. Although the correlation between diabetes and cancer incidence has been increasingly reported, the underlying molecular mechanisms beyond this association are not yet fully understood. Recent studies have suggested that high glucose levels support tumor progression through multiple mechanisms that are hallmarks of cancer, including cell proliferation, resistance to apoptosis, increased cell migration and invasiveness, epigenetic regulation (hyperglycemic memory), resistance to chemotherapy and altered metabolism. Most of the above occur because hyperglycemia through hexosamine biosynthetic pathway leads to aberrant O-GlcNAcylation of many intracellular proteins that are involved in those mechanisms. Deregulated O-GlcNAcylation is emerging as a general feature of cancer. Despite strong evidence suggesting that aberrant O-GlcNAcylation is or may be involved in the acquisition of all cancer hallmarks, it remains out of the list of the next generation of emerging hallmarks. Here, we discuss some of the current understanding on how hyperglycemia affects cancer cell biology and how aberrant O-GlcNAcylation stands in this context.     

American and korean ginseng tissue cultures: Growth,chemical analysis,and plantlet production

Summary Roots, stems, or leaves of American (Panax quinquefolium) and Korean (Panax ginsing) ginseng were grown as callus or supension tissue cultures. Tissue cultures ofP. ginseng would occasionally form plantlets. The fundamental chemical composition, inorganic analysis, and saponin (panaquilin) content of American and Korean ginseng plants and tissue cultures were determined. The crude saponin content is very similar to, but approximately one-half (1.3%, fresh weight) of that present in ginseng roots. Two-dimensional thin layer chromatographic analysis revealed minor differences in the panaquilins present in American and Korean ginseng tissue cultures. The sapogenin, panaxadiol, was isolated from Korean ginseng callus.     

Ground wētā in vines of the Awatere Valley,Marlborough: biology,density and distribution

The endemic New Zealand ground wētā (Hemiandrus sp. ‘promontorius’) has a Naturally Uncommon conservation status. This is because of the paucity of information on its density and distribution. Here, the biology, density and distribution of a population of this wētā found in and around vineyards in the Awatere Valley, Marlborough was studied. Wētā density was assessed in vineyards, paddocks and shrublands in this valley. Soil moisture, penetration resistance, pH and organic matter were recorded at locations with and without wētā. Wētā density in vineyards was significantly higher than in either paddocks or shrub habitats. In vineyards, the density of this insect was significantly higher under-vines than in the inter-rows. Higher numbers of this wētā were found in moist soils that required lower force to burrow. Females laid an average of 55 eggs between March and April, which hatched in September. These findings highlight the intersection between agriculture and conservation.