Intraspecific queen parasitism in a highly eusocial bee

Insect societies are well-known for their advanced cooperation, but their colonies are also vulnerable to reproductive parasitism. Here, we present a novel example of an intra-specific social parasitism in a highly eusocial bee, the stingless bee Melipona scutellaris. In particular, we provide genetic evidence which shows that, upon loss of the mother queen, many colonies are invaded by unrelated queens that fly in from unrelated hives nearby. The reasons for the occurrence of this surprising form of social parasitism may be linked to the fact that unlike honeybees, Melipona bees produce new queens in great excess of colony needs, and that this exerts much greater selection on queens to seek alternative reproductive options, such as by taking over other nests. Overall, our results are the first to demonstrate that queens in highly eusocial bees can found colonies not only via supersedure or swarming, but also by infiltrating and taking over other unrelated nests.

Minimizing total tardiness in a stochastic single machine scheduling problem using approximate dynamic programming

This paper addresses the non-preemptive single machine scheduling problem to minimize total tardiness. We are interested in the online version of this problem, where orders arrive at the system at random times. Jobs have to be scheduled without knowledge of what jobs will come afterwards. The processing times and the due dates become known when the order is placed. The order release date occurs only at the beginning of periodic intervals. A customized approximate dynamic programming method is introduced for this problem. The authors also present numerical experiments that assess the reliability of the new approach and show that it performs better than a myopic policy.

Pheromone paths attached to the substrate in meliponine bees: helpful but not obligatory for recruitment success

In contrast to marking of the location of resources or sexual partners using single-spot pheromone sources, pheromone paths attached to the substrate and assisting orientation are rarely found among flying organisms. However, they do exist in meliponine bees (Apidae, Apinae, Meliponini), commonly known as stingless bees, which represent a group of important pollinators in tropical forests. Worker bees of several Neotropical meliponine species, especially in the genus Scaptotrigona Moure 1942, deposit pheromone paths on substrates between highly profitable resources and their nest. In contrast to past results and claims, we find that these pheromone paths are not an indispensable condition for successful recruitment but rather a means to increase the success of recruiters in persuading their nestmates to forage food at a particular location. Our results are relevant to a speciation theory in scent path-laying meliponine bees, such as Scaptotrigona. In addition, the finding that pheromone path-laying bees are able to recruit to food locations even across barriers such as large bodies of water affects tropical pollination ecology and theories on the evolution of resource communication in insect societies with a flying worker caste.

Downregulation of ultraspiracle gene expression delays pupal development in honeybees

Ecdysteroids regulate many aspects of insect physiology after binding to a heterodimer composed of the nuclear hormone receptor proteins ecdysone receptor (EcR) and ultraspiracle (Use). Several lines of evidence have suggested that the latter also plays important roles in mediating the action of juvenile hormone (JH) and, thus, integrates signaling by the two morphogenetic hormones. By using an RNAi approach, we show here that Us p participates in the mechanism that regulates the progression of pupal development in Apis mellifera, as indicated by the observed pupal developmental delay in usp knocked-down bees. Knock-down experiments also suggest that the expression of regulatory genes such as ftz transcription factor 1 (ftz-f1) and juvenile hormone esterase (jhe) depend on Usp. Vitellogenin (vg), the gene coding the main yolk protein in honeybees, does not seem to be under Usp regulation, thus suggesting that the previously observed induction of vg expression by JH during the last stages of pupal development is mediated by yet unknown transcription factor complexes. (C) 2008 Elsevier Ltd. All rights reserved.

Identification of a juvenile hormone esterase-like gene in the honey bee, Apis mellifera L. - Expression analysis and functional assays

Tight control over circulating juvenile hormone (JH) levels is of prime importance in an insect`s life cycle. Consequently, enzymes involved in JH metabolism, especially juvenile hormone esterases (JHEs), play major roles during metamorphosis and reproduction. In the highly eusocial Hymenoptera, JH has been co-opted into additional functions, primarily in the development of the queen and worker castes and in age-related behavioral development of workers. Within a set of 21 carboxylesterases predicted in the honey bee genome we identified one gene (Amjhe-like) that contained the main functional motifs of insect JHEs. Its transcript levels during larval development showed a maximum at the switch from feeding to spinning behavior, coinciding with a JH titer minimum. In adult workers, the highest levels were observed in nurse bees, where a low JH titer is required to prevent the switch to foraging. Functional assays showed that Amjhe-like expression is induced by JH-III and suppressed by 20-hydroxyecdysone. RNAi-mediated silencing of Amjhe-like gene function resulted in a six-fold increase in the JH titer in adult worker bees. The temporal profile of Amjhe-like expression in larval and adult workers, the pattern of hormonal regulation and the knockdown phenotype are consistent with the function of this gene as an authentic JHE. (C) 2008 Elsevier Inc. All rights reserved.

The juvenile hormone (JH) epoxide hydrolase gene in the honey bee (Apis mellifera) genome encodes a protein which has negligible participation in JH degradation

Epoxide hydrolases are multifunctional enzymes that are best known in insects for their role in juvenile hormone (JH) degradation. Enzymes involved in JH catabolism can play major roles during metamorphosis and reproduction, such as the JH epoxide hydrolase (JHEH), which degrades JH through hydration of the epoxide moiety to form JH diol, and JH esterase (JHE), which hydrolyzes the methyl ester to produce JH acid. In the honey bee, JH has been co-opted for additional functions, mainly in caste differentiation and in age-related behavioral development of workers, where the activity of both enzymes could be important for JH titer regulation. Similarity searches for jheh candidate genes in the honey bee genome revealed a single Amjheh gene. Sequence analysis, quantification of Amjheh transcript levels and Western blot assays using an AmJHEH-specific antibody generated during this study revealed that the AmJHEH found in the fat body shares features with the microsomal JHEHs from several insect species. Using a partition assay we demonstrated that AmJHEH has a negligible role in JH degradation, which, in the honey bee, is thus performed primarily by JHE. High AmJHEH levels in larvae and adults were related to the ingestion of high loads of lipids, suggesting that AmJHEH has a role in dietary lipid catabolism. (C) 2010 Elsevier Ltd. All rights reserved.

Discrete dimorphism among castes of the bald-faced hornet Dolichovespula maculata (Hymenoptera: Vespidae) in different phases of the colony cycle

Morphological and physiological caste differences were compared from colonies of Dolichovespula maculata in middle and late phases of the colony cycle. The females showed three patterns of ovarian development and only females classified as queens were inseminated. In both phases, queens were larger than workers for most measures. Discriminant analyses showed high distinction of caste in both phases. We also found highly pronounced qualitative differences: workers had hairs covering the entire body whereas queens had no hair and also some colour differences in the gaster. These results indicate that D. maculata presents pre-imaginal differentiation as seen in other Vespinae, and that size variation occurs from colony to colony such that queens of one colony may be comparable to workers of a different colony although the castes are always distinguishable within colonies.

Prognostic Significance of Myocardial Fibrosis Quantification by Histopathology and Magnetic Resonance Imaging in Patients With Severe Aortic Valve Disease

Objectives We sought to determine whether the quantitative assessment of myocardial fibrosis (MF), either by histopathology or by contrast-enhanced magnetic resonance imaging (ce-MRI), could help predict long-term survival after aortic valve replacement. Background Severe aortic valve disease is characterized by progressive accumulation of interstitial MF. Methods Fifty-four patients scheduled to undergo aortic valve replacement were examined by ce-MRI. Delayed-enhanced images were used for the quantitative assessment of MF. In addition, interstitial MF was quantified by histological analysis of myocardial samples obtained during open-heart surgery and stained with picrosirius red. The ce-MRI study was repeated 27 +/- 22 months after surgery to assess left ventricular functional improvement, and all patients were followed for 52 +/- 17 months to evaluate long-term survival. Results There was a good correlation between the amount of MF measured by histopathology and by ce-MRI (r = 0.69, p < 0.001). In addition, the amount of MF demonstrated a significant inverse correlation with the degree of left ventricular functional improvement after surgery (r = -0.42, p = 0.04 for histopathology; r = -0.47, p = 0.02 for ce-MRI). Kaplan-Meier analyses revealed that higher degrees of MF accumulation were associated with worse long-term survival (chi-square = 6.32, p = 0.01 for histopathology; chi-square = 5.85, p = 0.02 for ce-MRI). On multivariate Cox regression analyses, patient age and the amount of MF were found to be independent predictors of all-cause mortality. Conclusions The amount of MF, either by histopathology or by ce-MRI, is associated with the degree of left ventricular functional improvement and all-cause mortality late after aortic valve replacement in patients with severe aortic valve disease. (J Am Coll Cardiol 2010; 56: 278-87) (c) 2010 by the American College of Cardiology Foundation

Randomized Evaluation of Two Drug-Eluting Stents With Identical Metallic Platform and Biodegradable Polymer But Different Agents (Paclitaxel or Sirolimus) Compared Against Bare Stents: 1-Year Results of the PAINT Trial

Objectives: We tested two novel drug-eluting stents (DES), covered with a biodegradable-polymer carrier and releasing paclitaxel or sirolimus, which were compared against a bare metal stent (primary objective). The DES differed by the drug, but were identical otherwise, allowing to compare the anti-restenosis effects of sirolimus versus paclitaxel (secondary objective). Background: The efficacy of novel DES with biodegradable polymers should be tested in the context of randomized trials, even when using drugs known to be effective, such as sirolimus and paclitaxel. Methods: Overall, 274 patients with de novo coronary lesions in native vessels scheduled for stent implantation were randomly assigned (2:21 ratio) for the paclitaxel (n = 111), sirolimus (n = 106), or bare metal stent (n = 57) groups. Angiographic follow-up was obtained at 9 months and major cardiac adverse events up to 12 months. Results: Both paclitaxel and sirolimus stents reduced the 9-month in-stent late loss (0.54-0.44 mm, 0.32-0.43 mm, vs. 0.90-0.45 mm respectively), and 1-year risk of target vessel revascularization and combined major adverse cardiac events (P < 0.05 for both, in all comparisons), compared with controls. Sirolimus stents had lower late loss than paclitaxel stents (P < 0.01), but similar 1-year clinical outcomes. There were no differences in the risk of death, infarction, or stent thrombosis among the study groups. Conclusion: Both novel DES were effective in reducing neointimal hyperplasia and 1-year re-intervention, compared to bare metal stents. Our findings also suggest that sirolimus is more effective than paclitaxel in reducing angiographic neointima, although this effect was not associated with better clinical outcomes. (C) 2009 Wiley-Liss, Inc.

Comparison of reading performance after bilateral implantation of multifocal intraocular lenses with+3.00 or+4.00 diopter addition

PURPOSE To compare reading ability after cataract surgery and bilateral implantation of multifocal intraocular lenses (IOLs) with a +3 00 diopter (D) addition (add) or a +4 00 D add SETTING Department of Ophthalmology, University of Sao Paulo, Sao Paulo, Brazil DESIGN Prospective comparative study METHODS Patients scheduled for cataract surgery were randomly assigned to bilateral implantation of an aspheric AcrySof ReSTOR multifocal IOL with a +3 00 diopter (D) addition (add) or a +4 00 D add The reading speed, critical print size, and reading acuity were measured binocularly with best correction using MNREAD acuity charts 6 months after surgery Patients were tested with the chart at the best patient-preferred reading distance and at 40 cm Binocular uncorrected and best distance-corrected visual acuities at far and near were also measured RESULTS The study enrolled 32 patients At the best reading distance the results were similar between the 2 IOL groups in all reading parameters When tested at 40 cm, reading speed at all print sizes from 03 to 00 (all P< 001), critical print size (P< 001) and reading acuity (P = 014) were statistically significantly better in the +3 00 D IOL group than in the +4 00 DIOL group Uncorrected and corrected visual acuities at far and near were similar between the 2 groups CONCLUSION Although the 2 IOL groups had similar performance in reading parameters, patients had to adjust to their best reading distance The +3 00 D IOL performed better than the +4 00 D IOL at 40 cm

Uptake by breast carcinoma of a lipidic nanoemulsion after intralesional injection into the patients: A new strategy for neoadjuvant chemotherapy

Objective. Previously we showed that after intravenous injection a lipidic nanoemulsion concentrates in breast carcinoma tissue and other solid tumors and may carry drugs directed against neoplastic tissues. Use of the nanoemulsion decreases toxicity of the chemotherapeutic agents without decreasing the anticancer action. Currently, the hypothesis was tested whether the nanoemulsion concentrates in breast carcinoma tissue after locoregional injection. Methods. Three different techniques of injection of the nanoemulsion were tested in patients scheduled for surgical treatment: G1 (n=4) into the mammary tissue 5 cm away from the tumor; G2 (n=4) into the peritumoral mammary tissue; G3 (n=6) into the tumoral tissue. The nanoemulsion labeled with radioactive cholesteryl oleate was injected 12 h before surgery; plasma decay of the label was determined from blood samples collected over 24 h and the tissue fragments excised during the surgery were analyzed for radioactivity uptake. Results. Among the three nanoemulsion injection techniques, G3 showed the greatest uptake (data expressed in c.p.m/g of tissue) by the tumor (44,769 +/- 54,749) and by the lymph node (2356 +/- 2966), as well as the greatest concentration in tumor compared to normal tissue (844 +/- 1673). In G1 and G2, uptakes were, respectively, tumor: 60 +/- 71 and 843 +/- 1526; lymph node: 263 +/- 375 and 102 +/- 74; normal tissue: 139 +/- 102 and 217 +/- 413. Conclusions. Therefore, with intralesional injection of the nanoemulsion, a great concentration effect can be achieved. This injection technique may be thus a promising approach for drug-targeting in neoadjuvant chemotherapy in breast cancer treatment. (C) 2008 Published by Elsevier Inc.

A Randomized Trial of a Skin Sealant to Reduce the Risk of Incision Contamination in Cardiac Surgery

Background. Immobilizing skin microbes is a rational approach to reducing contamination of surgical sites by endogenous microorganisms. Methods. This randomized, controlled, parallel-group, multicenter, open-label clinical trial (ClinicalTrials.gov NCT00467857) enrolled 300 adults scheduled for elective coronary artery bypass graft surgery. Patients received iodine-based skin preparations followed by a cyanoacrylate-based skin sealant or skin preparations alone. Microbiological samples collected from sternal and graft incision sites immediately before any skin preparation, at the wound border after skin incision, and at the incision after fascial closure were evaluated quantitatively. Results. In evaluable patients, mean microbial counts in collected samples increased at the sternal site after fascial closure compared with after skin incision by 0.37 log(10) colony-forming units (CFU)/mL in the skin sealant group (n = 120) and by 0.57 log10 CFU/mL in the control group (n = 132) (p = 0.047, Wilcoxon rank sum test). At the graft site, mean microbial counts increased by 0.09 (n = 119) and 0.27 (n = 127) log(10) CFU/mL, respectively (p = 0.037). There was a 35.3% relative risk reduction in surgical site infection (SSI) occurring in the skin sealant group (9 of 146 patients, 6.2%) versus the control group (14 of 147 patients, 9.5%). In obese patients (body mass index [BMI] > 30.0 to <= 37.0 kg/m(2)), the relative risk reduction for SSI associated with skin sealant was 83.3%. Conclusions. Pretreatment with skin sealant protects against contamination of the surgical incision by migration of skin microbes. Further data are needed to confirm the impact of this technology on SSI rates in clinical practice. (Ann Thorac Surg 2011;92:632-7) (C) 2011 by The Society of Thoracic Surgeons ADULT CARDIAC

Azithromycin does not prevent six-month myointimal proliferation but attenuates the transient systemic inflammation occurring after coronary stenting

Stent implantation produces a systemic increase of inflammatory markers that correlates with Chlamydophila pneumoniae infection in atherosclerotic plaque. We performed a clinical intervention study to investigate the effect of antibiotic treatment on 6-month follow-up angiographic minimal luminal diameter after stenting. Ninety patients were randomly assigned to oral azithromycin or placebo in a double-blinded and randomized fashion. Medication was initiated 2 weeks before a pre-scheduled stenting procedure and maintained 12 weeks thereafter. Angiographic outcomes were evaluated by a six-month follow-up angiography and laboratorial parameters were accessed by blood sampling 2 weeks before stenting, within the first 24 h after procedure and additional samples after four weeks and 6 months. Minimal luminal diameter (1.76 +/- A 0.56 mm Vs. 1.70 +/- A 0.86 mm; P = 0.7), restenosis rate, diameter stenosis, late loss, and binary restenosis rates were comparable in placebo and azithromycin group in the 6 months follow-up. Serum levels of C-reactive protein presented a three fold significant increase in the control group one day after stenting but did not change in the azithromycin group (8.5 [3.0;16.4] Vs. 2.9 [1.7;6.6]-median [25;75 percentile] P < 0.01). Azithromycin does not improve late angiographic outcomes but attenuates the elevation of C-reactive protein levels after stenting, indicating an anti-inflammatory effect.

Complete Clinical Response After Neoadjuvant Chemoradiation Therapy for Distal Rectal Cancer: Characterization of Clinical and Endoscopic Findings for Standardization

BACKGROUND: Complete tumor regression may develop after neoadjuvant chemoradiation therapy for distal rectal cancer. Studies have suggested that selected patients with complete clinical response may avoid radical surgery and close surveillance may provide good outcomes with no oncologic compromise. However, definition of complete clinical response is often imprecise and may vary between different studies. The aim of this study is to provide a clear definition for a complete clinical response after neoadjuvant chemoradiation therapy in patients with distal rectal cancer in addition to actual endoscopic videos from patients managed nonoperatively. METHODS: Patients with nonmetastatic distal rectal cancer treated by neoadjuvant chemoradiation therapy, including 50.4 Gy and concomitant 5-fluorouracil and leucovorin, were assessed for tumor response at least 8 weeks after chemoradiation therapy completion. Complete and incomplete clinical responses were defined based on clinical and endoscopic findings. Patients with complete clinical response were not immediately operated on and were closely followed. Early and late endoscopic findings were recorded. RESULTS: Definition of a complete clinical response should be based on very strict clinical and endoscopic criteria. The finding of any residual superficial ulceration, irregularity, or nodule should prompt surgical attention, including transanal full-thickness excision or even a radical resection with total mesorectal excision. Standard or incisional biopsies should be avoided in this setting. Complete clinical responders should harbor no more than whitening of the mucosa, teleangiectasia with mucosal integrity to be considered for a nonoperative approach. In the presence of these findings, regularly scheduled reassessments may provide a safe alternative to these patients with early detection of recurrent disease. CONCLUSION: Strict definition of the clinical and endoscopic findings of patients experiencing complete clinical response after neoadjuvant chemoradiation therapy may provide a useful tool for the understanding of outcomes of patients managed with no immediate surgery allowing standardization of classifications and comparison between the experiences of different institutions.

Early keratocyte apoptosis after epithelial scrape injury in the human cornea

Animal studies in mice, rats, rabbits, pigs and hens demonstrated that anterior keratocytes undergo programmed cell death or apoptosis after corneal epithelial injury. Many other wound healing changes subsequently follow the keratocyte apoptosis response. This study evaluated early keratocyte apoptosis after corneal epithelial scrape injury in human eyes scheduled for enucleation for malignancy. Two eyes had corneal epithelial scrape 1 h prior to the enucleation and another eye served as a control and had no corneal scrape prior to enucleation. One additional eye was enucleated, washed with balanced salt solution, and then had the corneal epithelium scraped 1 h prior to processing for analysis. Apoptosis was identified by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay and confirmed by transmission electron microscopy (TEM). Anterior keratocyte apoptosis was detected in the three corneas that had epithelial scrape injury, but not in the control unwounded cornea. This study confirmed that keratocyte apoptosis is also an early response to corneal epithelial injury in humans and showed that tears are not essential for keratocyte apoptosis to occur in response to epithelial injury. (C) 2009 Elsevier Ltd. All rights reserved.