Objective: To determine whether the somatostatin receptor subtype (SSTR) expression profile correlates with hormonal and tumor volume responses to postsurgical octreotide long acting repeatable (OCT LAR) treatment. Design and methods: Quantitative real-time RT-PCR was used to evaluate the absolute mRNA copy numbers for all five SSTR subtypes in 22 somatotropinomas. Response to OCT LAR was studied by hormone levels (GH and IGF-I) and tumor volume (sella turcica magnetic resonance imaging). Results: SSTR5 was present at the highest level followed by SSTR2, SSTR3, SSTR1, and SSTR4 (2327 (1046-5555), 2098, 97 (0-460), 14 (0-29 480), and 0 (0-652) copies respectively). Positive correlations were found between SSTR2 levels and the percentage decrease of GH and IGF-I after 3 (rZ0.49, P!0.027 and rZ0.49, P!0.029 respectively) and 6 (rZ0.59, P!0.006 and rZ0.58, P!0.008 respectively) months of OCT LAR. A negative correlation was found between SSTR5 mRNA levels and the percentage decrease of GH after 3 months of OCT LAR (rZK0.52, PZ0.016, nZ21). A higher SSTR2/SSTR5 ratio was observed among patients who obtained hormonal control with OCT LAR, when compared with those uncontrolled (2.4 (0.7-10) vs 0.3 (0.1-7.7), PZ0.001). A ROC curve analysis showed a SSTR2/SSTR5 ratio of 1.3 as the best predictor of disease control, with a sensitivity of 88% and a specificity of 92% -area under curve, 0.9. A positive correlation was also found between SSTR2 mRNA levels and the percentage decrease in tumor volume after 6 months of OCT LAR (rZ0.79, PZ0.002, nZ12). Conclusions: Somatostatin receptor subtype 2 mRNA expression levels in somatotropinomas correlate positively with in vivo hormonal and tumor volume responses to OCT LAR. European Journal of Endocrinology 158 295-303

DR2 is the predominant DR subtype in NPs, NFPAs, and somatotropinomas. The fact that DR1, DR4, and DR5 are also expressed in many adenomas tested suggests that these receptors might also play a role in the therapeutic impact of postsurgical medical therapies in patients with NFPA and acromegaly. This was supported by the finding that the in vivo response to octreotide-LAR was negatively associated with DR1 and positively associated with DR5.

Fire ants are well-known by their aggressive stinging behavior, causing many stinging incidents of medical importance. The limited availability of fire ant venom for scientific and clinical uses has restricted, up to now, the knowledge about the biochemistry, immunology, and pharmacology of these venoms. For this study, S. invicta venom was obtained commercially and used for proteomic characterization. For this purpose, the combination of gel-based and gel-free proteomic strategies was used to assign the proteomic profile of the venom from the fire ant S. invicta. This experimental approach permitted the identification of 46 proteins, which were organized into four different groups according to their potential role in fire ant venom: true venom components, housekeeping proteins, body muscle proteins, and proteins involved in chemical communication. The active venom components that may not present toxic roles were classified into three subgroups according to their potential functions: self-venom protection, colony asepsis, and chemical communication. Meanwhile, the proteins classified as true toxins, based on their functions after being injected into the victims' bodies by the fire ants, were classified in five other subgroups: proteins influencing the homeostasis of the victims, neurotoxins, proteins that promote venom diffusion, proteins that cause tissue damage/inflammation, and allergens.

A heme-binding protein has been isolated and characterized from both the hemolymph and oocytes of the blood-sucking insect, Rhodnius prolixus. The protein from both sources is identical in most aspects studied. The Rhodnius heme-binding protein (RHBP) is composed of a single 15-kDa polypeptide chain coiled in a highly alpha-helical structure which binds non-covalently one heme/polypeptide chain. This RHBP is not produced by limited degradation of hemoglobin from the vertebrate host, since specific polyclonal antibodies against it do not cross-react with rabbit hemoglobin, and since it differs from hemoglobin in having a distinct amino-acid composition and NH2-terminal sequence. The spectrum of the dithionite-reduced protein has peaks at 426, 530, and 559 nm and resembles that of a b-type cytochrome. RHBP from hemolymph is not saturated with heme and promptly binds heme added to the solution. The oocyte protein, on the other hand, is fully saturated and is not capable of binding additional heme.

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Inorganic polyphosphate (PolyP) is a biological polymer that plays important roles in the cell physiology of both prokaryotic and eukaryotic organisms. Among the available methods for PolyP localization and quantification, a 4’,6-diamidino-2-phenylindole(DAPI)-based assay has been used for visualization of PolyP-rich organelles. Due to differences in DAPI permeability to different compartments and/or PolyP retention after fixation, a general protocol for DAPI-PolyP staining has not yet been established. Here, we tested different protocols for DAPI-PolyP detection in a range of samples with different levels of DAPI permeability, including subcellular fractions, free-living cells and cryosections of fixed tissues. Subcellular fractions of PolyP-rich organelles yielded DAPI-PolyP fluorescence, although those with a complex external layer usually required longer incubation times, previous aldehyde fixation and/or detergent permeabilization. DAPI-PolyP was also detected in cryosections of OCT-embedded tissues analyzed by multiphoton microscopy. In addition, a semi-quantitative fluorimetric analysis of DAPI-stained fractions showed PolyP mobilization in a similar fashion to what has been demonstrated with the use of enzyme-based quantitative protocols. Taken together, our results support the use of DAPI for both PolyP visualization and quantification, although specific steps are suggested as a general guideline for DAPI-PolyP staining in biological samples with different degrees of DAPI and PolyP permeability.

Cockroaches are insects that can accommodate diets of different composition, including lignocellulosic materials. Digestion of these compounds is achieved by the insect’s own enzymes and also by enzymes produced by gut symbionts. The presence of different and modular bacterial phyla on the cockroach gut tract suggests that this insect could be an interesting model to study the organization of gut bacterial communities associated with the digestion of different lignocellulosic diets. Thus, changes in the diversity of gut associated bacterial communities of insects exposed to such diets could give useful insights on how to improve hemicellulose and cellulose breakdown systems. In this work, through sequence analysis of 16S rRNA clone libraries, we compared the phylogenetic diversity and composition of gut associated bacteria in the cockroach Periplaneta americana collected in the wild-types or kept on two different diets: sugarcane bagasse and crystalline cellulose. These high fiber diets favor the predominance of some bacterial phyla, such as Firmicutes, when compared to wild-types cockroaches. Our data show a high bacterial diversity in P. americana gut, with communities composed mostly by the phyla Bacteroidetes, Firmicutes, Proteobacteria and Synergistetes. Our data show that the composition and diversity of gut bacterial communities could be modulated by diet composition. The increased presence of Firmicutes in sugarcane bagasse and crystalline cellulose-fed animals suggests that these bacteria are strongly involved in lignocellulose digestion in cockroach guts.BackgroundCockroaches are omnivorous animals that can incorporate in their diets food of different composition, including lignocellulosic materials. Digestion of these compounds is achieved by the insect’s own enzymes and also by enzymes produced by gut symbiont. However, the influence of diet with different fiber contents on gut bacterial communities and how this affects the digestion of cockroaches is still unclear. The presence of some bacterial phyla on gut tract suggests that cockroaches could be an interesting model to study the organization of gut bacterial communities during digestion of different lignocellulosic diets. Knowledge about the changes in diversity of gut associated bacterial communities of insects exposed to such diets could give interesting insights on how to improve hemicellulose and cellulose breakdown systems.Methodology/principal findingsWe compared the phylogenetic diversity and composition of gut associated bacteria in the cockroach P. americana caught on the wild or kept on two different diets: sugarcane bagasse and crystalline cellulose. For this purpose we constructed bacterial 16S rRNA gene libraries which showed that a diet rich in cellulose and sugarcane bagasse favors the predominance of some bacterial phyla, more remarkably Firmicutes, when compared to wild cockroaches. Rarefaction analysis, LIBSHUFF and UniFrac PCA comparisons showed that gene libraries of wild insects were the most diverse, followed by sugar...

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