Striking cuticular hydrocarbon dimorphism in the mason wasp Odynerus spinipes and its possible evolutionary cause (Hymenoptera: Chrysididae,Vespidae)

Cleptoparasitic wasps and bees smuggle their eggs into the nest of a host organism. Here the larvae of the cleptoparasite feed upon the food provision intended for the offspring of the host. As cleptoparasitism incurs a loss of fitness for the host organism (offspring of the host fail to develop), hosts of cleptoparasites are expected to exploit cues that alert them to potential cleptoparasite infestation. Cuticular hydrocarbons (CHCs) could serve as such cues, as insects inevitably leave traces of them behind when entering a nest. By mimicking the host''s CHC profile, cleptoparasites can conceal their presence and evade detection by their host. Previous studies have provided evidence of cleptoparasites mimicking their host''s CHC profile. However, the impact of this strategy on the evolution of the host''s CHC profile has remained unexplored. Here, we present results from our investigation of a host–cleptoparasite system consisting of a single mason wasp species that serves syntopically as the host to three cuckoo wasp species. We found that the spiny mason wasp (Odynerus spinipes) is able to express two substantially different CHC profiles, each of which is seemingly mimicked by a cleptoparasitic cuckoo wasp (i.e. Chrysis mediata and Pseudospinolia neglecta). The CHC profile of the third cuckoo wasp (Chrysis viridula), a species not expected to benefit from mimicking its host''s CHC profile because of its particular oviposition strategy, differs from the two CHC profiles of its host. Our results corroborate the idea that the similarity of the CHC profiles between cleptoparasitic cuckoo wasps and their hosts are the result of chemical mimicry. They further suggest that cleptoparasites may represent a hitherto unappreciated force that drives the evolution of their hosts'' CHCs.     

Intratumoral anti-HuD immunotoxin therapy for small cell lung cancer and neuroblastoma

Background

Most patients with small cell lung cancer (SCLC) or neuroblastoma (NB) already show clinically detectable metastases at diagnosis and have an extremely poor prognosis even when treated with combined modalities. The HuD-antigen is a neuronal RNA-binding protein that is expressed in 100% of SCLC tumor cells and over 50% of neuroblastoma cells. The correlation between high titers of circulating anti-HuD antibodies in patients and spontaneous tumor remission suggests that the HuD-antigen might be a potential molecular target for immunotherapy.

Methods

We have constructed a new antibody-toxin compound (called BW-2) by assembling a mouse anti-human-HuD monoclonal antibody onto streptavidin/saporin complexes.

Results

We found that the immunotoxin BW-2 specifically killed HuD-positive human SCLC and NB cancer cells at very low concentrations in vitro. Moreover, intratumoral immunotoxin therapy in a nude mouse model of human SCLC (n?=?6) significantly reduced local tumor progression without causing toxicity. When the same intratumoral immunotoxin protocol was applied to an immunocompetent A/J mouse model of NB, significant inhibition of local tumor growth was also observed. In neuroblastoma allografted A/J mice (n?=?5) treated twice with intratumoral immunotoxin, significant tumor regression occurred in over 80% of the animals and their duration of tumor response was significantly prolonged.

Conclusions

Our study suggests that anti-HuD based immunotoxin therapy may prove to be an effective alternative treatment for patients with SCLC and NB.

     

The Effect of Dosing Regimens on the Antimalarial Efficacy of Dihydroartemisinin-Piperaquine: A Pooled Analysis of Individual Patient Data

Background

Dihydroartemisinin-piperaquine (DP) is increasingly recommended for antimalarial treatment in many endemic countries; however, concerns have been raised over its potential under dosing in young children. We investigated the influence of different dosing schedules on DP''s clinical efficacy.

Methods and Findings

A systematic search of the literature was conducted to identify all studies published between 1960 and February 2013, in which patients were enrolled and treated with DP. Principal investigators were approached and invited to share individual patient data with the WorldWide Antimalarial Resistance Network (WWARN). Data were pooled using a standardised methodology. Univariable and multivariable risk factors for parasite recrudescence were identified using a Cox''s regression model with shared frailty across the study sites. Twenty-four published and two unpublished studies (n = 7,072 patients) were included in the analysis. After correcting for reinfection by parasite genotyping, Kaplan–Meier survival estimates were 97.7% (95% CI 97.3%–98.1%) at day 42 and 97.2% (95% CI 96.7%–97.7%) at day 63. Overall 28.6% (979/3,429) of children aged 1 to 5 years received a total dose of piperaquine below 48 mg/kg (the lower limit recommended by WHO); this risk was 2.3–2.9-fold greater compared to that in the other age groups and was associated with reduced efficacy at day 63 (94.4% [95% CI 92.6%–96.2%], p<0.001). After adjusting for confounding factors, the mg/kg dose of piperaquine was found to be a significant predictor for recrudescence, the risk increasing by 13% (95% CI 5.0%–21%) for every 5 mg/kg decrease in dose; p = 0.002. In a multivariable model increasing the target minimum total dose of piperaquine in children aged 1 to 5 years old from 48 mg/kg to 59 mg/kg would halve the risk of treatment failure and cure at least 95% of patients; such an increment was not associated with gastrointestinal toxicity in the ten studies in which this could be assessed.

Conclusions

DP demonstrates excellent efficacy in a wide range of transmission settings; however, treatment failure is associated with a lower dose of piperaquine, particularly in young children, suggesting potential for further dose optimisation. Please see later in the article for the Editors'' Summary     

Effects of vitamin E and beta-carotene on sperm competitiveness

Sperm are particularly prone to oxidative damage because they generate reactive oxygen species (ROS), have a high polyunsaturated fat content and a reduced capacity to repair DNA damage. The dietary compounds vitamin E and beta-carotene are argued to have antioxidant properties that help to counter the damaging effects of excess ROS. Here in, we tested the post-copulatory consequences for male crickets (Teleogryllus oceanicus) of dietary intake of these two candidate antioxidants. During competitive fertilisation trials, vitamin E, but not beta-carotene, singularly enhanced sperm competitiveness. However, the diet combining a high vitamin E dose and beta-carotene produced males with the most competitive ejaculates, possibly due to the known ability of beta-carotene to recycle vitamin E. Our results provide support for the idea that these two common dietary compounds have interactive antioxidant properties in vivo, by affecting the outcomes of male reproductive success under competitive conditions.     

Phosphoinositide regulation of integrin trafficking required for muscle attachment and maintenance

Muscles must maintain cell compartmentalization when remodeled during development and use. How spatially restricted adhesions are regulated with muscle remodeling is largely unexplored. We show that the myotubularin (mtm) phosphoinositide phosphatase is required for integrin-mediated myofiber attachments in Drosophila melanogaster, and that mtm-depleted myofibers exhibit hallmarks of human XLMTM myopathy. Depletion of mtm leads to increased integrin turnover at the sarcolemma and an accumulation of integrin with PI(3)P on endosomal-related membrane inclusions, indicating a role for Mtm phosphatase activity in endocytic trafficking. The depletion of Class II, but not Class III, PI3-kinase rescued mtm-dependent defects, identifying an important pathway that regulates integrin recycling. Importantly, similar integrin localization defects found in human XLMTM myofibers signify conserved MTM1 function in muscle membrane trafficking. Our results indicate that regulation of distinct phosphoinositide pools plays a central role in maintaining cell compartmentalization and attachments during muscle remodeling, and they suggest involvement of Class II PI3-kinase in MTM-related disease.     

A method for CP 47, 497 a synthetic non-traditional cannabinoid in human urine using liquid chromatography tandem mass spectrometry

A rapid method has been developed to analyse CP 47, 497 in human urine. Urine samples were diluted with water:acetonitrile (90:10, v/v) and sample aliquots were analysed by triple quadrupole tandem mass spectrometry with a runtime of 5 min. Multiple reaction monitoring (MRM) as survey scan was performed. The method was validated in urine, according to an in-house validation protocol based on the criteria defined in Commission Decision 2002/657/EC. Three MRM transitions were monitored. The decision limit (CCα) was 0.01 μg mL^?1 and for the detection capability a (CCβ) value of 0.02 μg mL^?1 was obtained. The measurement uncertainty of the method was 21%. Fortifying human urine samples (n = 18) in three separate assays, show the accuracy of the method to be between 95 and 96%. The precision of the method, expressed as RSD values for the within-lab reproducibility at the three levels of fortification (0.1, 0.15 and 0.2 μg mL^?1) was less than 10% respectively. The method proved to be simple, robust and time efficient. To the best of our knowledge there are no LC–MS methods for the determination of CP 47, 497 with validation data in urine.     

Mycobacterial PIMs inhibit host inflammatory responses through CD14-dependent and CD14-independent mechanisms

Mycobacteria develop strategies to evade the host immune system. Among them, mycobacterial LAM or PIMs inhibit the expression of pro-inflammatory cytokines by activated macrophages. Here, using synthetic PIM analogues, we analyzed the mode of action of PIM anti-inflammatory effects. Synthetic PIM(1) isomer and PIM(2) mimetic potently inhibit TNF and IL-12 p40 expression induced by TLR2 or TLR4 pathways, but not by TLR9, in murine macrophages. We show inhibition of LPS binding to TLR4/MD2/CD14 expressing HEK cells by PIM(1) and PIM(2) analogues. More specifically, the binding of LPS to CD14 was inhibited by PIM(1) and PIM(2) analogues. CD14 was dispensable for PIM(1) and PIM(2) analogues functional inhibition of TLR2 agonists induced TNF, as shown in CD14-deficient macrophages. The use of rough-LPS, that stimulates TLR4 pathway independently of CD14, allowed to discriminate between CD14-dependent and CD14-independent anti-inflammatory effects of PIMs on LPS-induced macrophage responses. PIM(1) and PIM(2) analogues inhibited LPS-induced TNF release by a CD14-dependent pathway, while IL-12 p40 inhibition was CD14-independent, suggesting that PIMs have multifold inhibitory effects on the TLR4 signalling pathway.     

Anaerobic microbial activities including hydrogen mediated acetogenesis within natural gas transmission lines

Microbially influenced corrosion (MIC) is being increasingly recognised as a serious problem. To investigate the role of MIC, radiotracer activity and lipid biomass measurements were performed on samples from offshore and on‐shore natural gas transmission systems. These measurements evaluated the biomass and metabolism of microbial communities residing inside transmission pipelines. Aqueous and nonaqueous hydrocarbon samples from liquid separators, sludge catchers and nodules attached to pipe walls were aseptically recovered and inoculated into anaerobic tubes for radiotracer time course experiments or preserved with chloroform‐methanol for total lipid analyses. MPN enrichments and phospholipid biomass determinations estimated microbial populations of 10⁴—10⁷ cells per gram in several samples. General microbial metabolism was demonstrated by [l‐¹⁴C]acetate incorporation into lipids and by [¹⁴C]CO₂ production from [U‐¹⁴C]glucose. [¹⁴C]Acetate was slowly mineralised to ¹⁴CO₂ without significant methane production. [¹⁴C]Acetate was produced by fermentation of [¹⁴C]glucose, [¹⁴C]palmitate and by hydrogen mediated acetogenesis in the presence of [^I4C]CO₂. In one location acetogenesis from hydrogen and carbon dioxide accounted for 0–7 mmol.l^‐1 of acetate production per week. These results demonstrated that microorganisms could utilise natural gas impurities to produce organic acids. This activity could adversely affect the structural integrity (MIC) of high pressure natural gas pipelines.     

Performance of Rapid Point-of-Care and Laboratory Tests for Acute and Established HIV Infection in San Francisco

Background

Current laboratory and point-of-care tests for HIV detect different analytes and use different sample types. Some have fast turnaround times (<1 hour). We investigated how HIV test choice could impact case finding by testing programs.

Methods

We analyzed 21,234 consecutive HIV tests with venous blood obtained by San Francisco HIV testing programs from 2003 to 2008. For a subset, oral fluid (n = 6446) or fingerstick blood (n = 8127) samples were also obtained for rapid testing. In all cases, HIV status was determined using an HIV antibody-plus-RNA test algorithm. We assessed how the screening antibody tests performed individually versus the gold standard of the full algorithm. We then evaluated the potential ability of other tests (including new tests) to detect more cases, by re-testing all specimens that had negative/discrepant antibody results on initial screening.

Findings

The antibody-RNA algorithm identified 58 acute and 703 established HIV infection cases. 1^st-generation (Vironostika) and 3^rd-generation (Genetic Systems) immunoassays had 92 and 96 percent sensitivity, respectively. The Oraquick rapid test had clinical sensitivity of only 86 percent on oral fluid samples, but 92 percent on finger-stick blood. Newer 4^th-generation, antigen-antibody combo rapid immunoassay (ARCHITECT) detected HIV in 87 percent of all the acute cases that had been missed by one of the previous screening assays. A point-of-care 4^th generation antigen-antibody combo rapid test (Determine) detected about 54 percent of such acute cases.

Conclusions

Our study suggests that some rapid antibody blood tests will give similar case detection to laboratory antibody tests, but that oral fluid testing greatly reduces ability to detect HIV. New 4^th-generation combo tests can detect the majority of acute infections detectable by HIV RNA but with rapid results. Using these tests as a primary screening assay in high-risk HIV testing programs could reduce or eliminate the need for HIV RNA testing.     

Synthesis of a new trifluoromethylketone analogue of l-arginine and contrasting inhibitory activity against human arginase I and histone deacetylase 8

As part of our continuing search for new amino acid inhibitors of metalloenzymes, we now report the synthesis and biological evaluation of the trifluoromethylketone analogue of L-arginine, (S)-2-amino-8,8,8-trifluoro-7-oxo-octanoic acid (10). While this novel amino acid was initially designed as a potential inhibitor of human arginase I, it exhibits no measurable inhibitory activity against this enzyme. Surprisingly, however, 10 is a potent inhibitor of human histone deacetylase 8, with IC(50)=1.5 ± 0.2 μM. Additionally, 10 weakly inhibits the related bacterial enzyme, acetylpolyamine amidohydrolase, with IC(50)=110 ± 30 μM. The lack of inhibitory activity against human arginase I may result from unfavorable interactions of the bulky trifluoromethyl group of 10 in the constricted active site. Since the active site of histone deacetylase 8 is less constricted, we hypothesize that it accommodates 10 as the gem-diol, which mimics the tetrahedral intermediate and its flanking transition states in catalysis. Therefore, we suggest that 10 represents a new lead in the design of an amino acid or peptide-based inhibitor of histone deacetylases with simpler structure than previously studied trifluoromethylketones.