Maternal effect on female caste determination in a social insect.

Caste differentiation and division of labor are the hallmarks of social insect colonies [1, 2]. The current dogma for female caste differentiation is that female eggs are totipotent, with morphological and physiological differences between queens and workers stemming from a developmental switch during the larval stage controlled by nutritional and other environmental factors (e.g., [3-8]). In this study, we tested whether maternal effects influence caste differentiation in Pogonomyrmex harvester ants. By conducting crossfostering experiments we identified two key factors in the process of caste determination. New queens were produced only from eggs laid by queens exposed to cold. Moreover, there was a strong age effect, with development into queens occurring only in eggs laid by queens that were at least two years old. Biochemical analyses further revealed that the level of ecdysteroids was significantly lower in eggs developing into queens than workers. By contrast, we found no significant effect of colony size or worker exposure to cold, suggesting that the trigger for caste differentiation may be independent of the quantity and quality of resources provided to larvae. Altogether these data demonstrate that the developmental fate of female brood is strongly influenced by maternal effects in ants of the genus Pogonomyrmex.

Incidence of invasive cervical cancer in the Swiss canton of Vaud, and a note on screening.

Age adjusted incidence rates (World standard) from invasive cervical cancer in the Swiss canton of Vaud decreased from 17.7/100,000 in 1968-70 to 9.9/100,000 in 1983-85. The decline was substantial in younger middle age, but no appreciable trend was observed in women over 70. This is consistent with available interview based information on the pattern of cervical screening in the Swiss population. Although there was no organised screening programme in Switzerland, over 80% of women aged 20-44 and 65% of those aged 45-64 reported one or more screening smears over the previous 3 years, compared to only 22% of women aged 65 or over. In the last calendar period, there was an apparent increase in the incidence of invasive cervical cancer (from 2.5 to 6.1/100,000) in women aged 25-29. Although based on small absolute numbers, this is in agreement with incidence and mortality data from other countries, and may therefore confirm a change in risk factor exposure in younger women.

Clinical characteristics and outcome of patients admitted to a medico-surgical ICU requiring non invasive ventilation (NIV) for hypercapnic respiratory failure

Introduction: Because it decreases intubation rate and mortality, NIV has become first-line treatment in case of hypercapnic respiratory failure (HRF). Whether this approach is equally successful for all categories of HRF patients is however debated. We assessed if any clinical characteristics of HRF patients were associated with NIV intensity, success, and outcome, in order to identify prognostic factors. Methods: Retrospective analysis of the clinical database (clinical information system and MDSi) of patients consecutively admitted to our medico-surgical ICU, presenting with HRF (defined as PaCO2 >50 mm Hg), and receiving NIV between January 2009 and December 2010. Demographic data, medical diagnoses (including documented chronic lung disease), reason for ICU hospitalization, recent surgical interventions, SAPS II and McCabe scores were extracted from the database. Total duration of NIV and the need for tracheal intubation during the 5 days following the first hypercapnia documentation, as well as ICU and hospital mortality were recorded. Results are reported as median [IQR]. Comparisons with Chi2 or Kruskal-Wallis tests, p <0.05 (*). Results: 164 patients were included, 45 (27.4%) of whom were intubated after 10 [2-34] hours, after having received 7 [2-19] hours of NIV. NIV successful patients received 15 [5-22] hours of NIV for up to 5 days. Intubation was correlated with increased ICU (20% vs. 3%, p <0.001) and hospital (46.7% vs. 30.2, p >0.05) mortality. Conclusions: A majority of patients requiring NIV for hypercapnic respiratory failure in our ICU have no diagnosed chronic pulmonary disease. These patients tend to have increased ICUand hospital mortality. The majority of patients were non-surgical, a feature correlated with increased hospital mortality. Beside usual predictors of severity such as age and SAPS II, absence of diagnosed chronic pulmonary disease and non-operative state appear to be associated with increased mortality. Further studies should explore whether these patients are indeed more prone to an adverse outcome and which therapeutic strategies might contribute to alter this course.

Purification and ligand binding of a soluble class I major histocompatibility complex molecule consisting of the first three domains of H-2Kd fused to beta 2-microglobulin expressed in the baculovirus-insect cell system.

A recombinant baculovirus encoding a single-chain murine major histocompatibility complex class I molecule in which the first three domains of H-2Kd are fused to beta 2-microglobulin (beta 2-m) via a 15-amino acid linker has been isolated and used to infect lepidopteran cells. A soluble, 391-amino acid single-chain H-2Kd (SC-Kd) molecule of 48 kDa was synthesized and glycosylated in insect cells and could be purified in the absence of detergents by affinity chromatography using the anti-H-2Kd monoclonal antibody SF1.1.1.1. We tested the ability of SC-Kd to bind antigenic peptides using a direct binding assay based on photoaffinity labeling. The photoreactive derivative was prepared from the H-2Kd-restricted Plasmodium berghei circumsporozoite protein (P.b. CS) peptide 253-260 (YIPSAEKI), a probe that we had previously shown to be unable to bind to the H-2Kd heavy chain in infected cells in the absence of co-expressed beta 2-microglobulin. SC-Kd expressed in insect cells did not require additional mouse beta 2-m to bind the photoprobe, indicating that the covalently attached beta 2-m could substitute for the free molecule. Similarly, binding of the P.b. CS photoaffinity probe to the purified SC-Kd molecule was unaffected by the addition of exogenous beta 2-m. This is in contrast to H-2KdQ10, a soluble H-2Kd molecule in which beta 2-m is noncovalently bound to the soluble heavy chain, whose ability to bind the photoaffinity probe is greatly enhanced in the presence of an excess of exogenous beta 2-m. The binding of the probe to SC-Kd was allele-specific, since labeling was selectively inhibited only by antigenic peptides known to be presented by the H-2Kd molecule.

Current status of the whitefly Aleurodicus dispersus as an invasive pest in the CapeVerte Islands

In the last three decades, the spiralling whitefly (Aleurodicus dispersus) has become an important international pest. The movement of plants and parts of plants (such as fruits) in international trade and tourism, and by natural dispersal, has favoured its introduction to new areas. In common with others whiteflies of economic importance, the immature and adult stages cause direct feeding damage by piercing and sucking of sap from foliage, and indirect damage following the accumulation all over host plants of honeydew and waxy flocculent material produced by the insects. Spiralling whitefly is a pest of tropical and subtropical crops, and highly polyphagous. Up to the 1970s, it had been recorded on 44 genera of plants, belonging to 26 botanical families (Mound & Halsey, 1978). This situation changed with the dispersal of the pest to new areas. Nowadays, the spiralling whitefly is one of the major pest of vegetable, ornamental and fruit crops around the globe (Lambkin, 1999). Important host crops include: banana (Musa sapientum), Citrus spp., coconut (Cocos nocifera), eggplant (Solanum melanogena), guava (Psidium guajava), Hibiscus rosa sinensis, Indian almond (Terminalia catappa), papya (Carica papaya), Rosa sp. and tomato (Lycopersicon esculentum) (Saminathan & Jayaraj, 2001). Spiralling whitefly has its origin in the tropical Americas, including Brazil. Although the pest has been recorded only once in Brasil, in the 1920s in the state of Bahia (Bondar, 1923), it now has official quarantine status because of its economic importance. In the Cape Verte Islands, on the West African coast, the pest was initially introduced in the first half of 2000; it has since become established, reaching urban, natural and agricultural areas of the islands that constitute the archipelago. Since then, the pest has been causing damage to many native plants, ornamentals and cultivated food crops (Anon., 2001; Monteiro, 2004). The present study was done in order to produce an inventory of the most common host plants of spiralling whitefly in this new habitat.

Ants and their effects on an insect herbivore community associated with the inflorescences of Byrsonima crassifolia (Linnaeus) H.B.K. (Malpighiaceae)

The effects of ants on the insect community on inflorescences of Byrsonima crassifolia (Malpighiaceae) were tested in an ant exclusion experiment in a cerrado vegetation in southeastern Brazil. Forty-four species of insects (23 families) and nine species of ants (6 genera and 3 subfamilies) were found on the inflorescences of B. crassifolia. The exclusion of ants, primarily Camponotus sericeiventris and Camponotus spp., reduced the treehopper population to 20% of the original abundance. Ant exclusion and time influenced the abundance of chewing (Exclusion, P<0.001; Time, P<0.002), and sucking insects (Exclusion, P<0.02; Time, P<0.01). Twice as many chewing and sucking insects were found on ant-excluded inflorescences as compared to control inflorescences (P<0.001). One and half more sucking insects were found on ant-excluded than on control inflorescences. Only time significantly influenced the richness of chewing and sucking insects associated with B. crassifolia inflorescences. Inflorescences on control branches were significantly less attacked by herbivores than inflorescences on ant-excluded branches (P<0.001). Therefore, these results suggest that the presence of ants alters the structure of insect herbivore community associated with B. crassifolia.

Combination of diatomaceous earth and powder deltamethrin for insect control in stored corn

The use of diatomaceous earth (DE) is a very efficient insect control measure in stored grain IPM due to its low cost, easy application, reduction of active ingredient residues, lower environmental contamination and operator safety. The objective of this research was to evaluate the efficacy of different dosages of DE mixed with powder deltamethrin for controlling Sitophilus zeamais in stored corn. Samples of 100 g of clean and dry corn, in three replicates, were submitted to the following treatments: DE (Keepdry®), at the dosages of 500, 750 and 1000 g/t; powder deltamethrin (K-Obiol®) at 0,5 g a.i. /t and 1,0 g a.i. /t; and combinations of the lowest and highest DE dosages with the two dosages of deltamethrin. Thirty adults of S. zeamais were placed in each vial with the treated grains and kept in environment chambers at 25ºC. Mortality was evaluated from the 1st to the 28th day. In the treatments mixing DE with deltamethrin or deltamethrin alone, the mortalyti was registered since the first day. In the treatments using only DE, the first dead insects were recorded after the 3rd day, especially in the highest dosages. After the 7th day, however, there was no statistical difference among all treatments, except for the lowest dosage of DE which reached a satisfactory control level only by the 14th day. It was concluded that treatments using DE combined with low dosages of powder deltamethrin represent an efficient control measure against S. zeamais in stored corn because insect mortality is faster than in treatments using DE alone and residues of active ingredients are much lower than using the insecticide in high dosages.

Regulation of the expression of Fit insect toxin locus genes in the root-associated biocontrol pseudomonad CHA0

The root-colonizing Pseudomonas fluorescens strain CHA0 is a biocontrol agent of soil-borne plant diseases caused by fungal and oomycete pathogens. Remarkably, this plant-beneficial pseudomonad is also endowed with potent insecticidal activity that depends on the production of a large protein toxin termed Fit (for P. fluorescens insecticidal toxin). In our present work, the genomic locus encoding the P. fluorescens insect toxin is subjected to a detailed molecular analysis. The Fit toxin gene fitD is flanked upstream by the fitABC genes and downstream by the fitE gene that encode the ABC transporter, membrane fusion, and outer membrane efflux components of a type I protein secretion system predicted to function in toxin export. The fitF, fitG, and fitH genes located downstream of fitE code for regulatory proteins having domain structures typical of signal transduction histidine kinases, LysR-type transcriptional regulators, and response regulators, respectively. The role of these insect toxin locus-associated control elements is being investigated with mutants defective for the regulatory genes and with GFP-based reporter fusions to putative promoter regions upstream of the transporter genes fitA and fitE, the toxin gene fitD, and the regulatory genes fitF and fitH. Our preliminary findings suggest that the three regulators interact with known global regulators of biocontrol factor expression to control Fit toxin expression and secretion.

Invasive candidiasis as a cause of sepsis in the critically ill patient.

Invasive fungal infections are an increasingly frequent etiology of sepsis in critically ill patients causing substantial morbidity and mortality. Candida species are by far the predominant agent of fungal sepsis accounting for 10% to 15% of health-care associated infections, about 5% of all cases of severe sepsis and septic shock and are the fourth most common bloodstream isolates in the United States. One-third of all episodes of candidemia occur in the intensive care setting. Early diagnosis of invasive candidiasis is critical in order to initiate antifungal agents promptly. Delay in the administration of appropriate therapy increases mortality. Unfortunately, risk factors, clinical and radiological manifestations are quite unspecific and conventional culture methods are suboptimal. Non-culture based methods (such as mannan, anti-mannan, β-d-glucan, and polymerase chain reaction) have emerged but remain investigational or require additional testing in the ICU setting. Few prophylactic or pre-emptive studies have been performed in critically ill patients. They tended to be underpowered and their clinical usefulness remains to be established under most circumstances. The antifungal armamentarium has expanded considerably with the advent of lipid formulations of amphotericin B, the newest triazoles and the echinocandins. Clinical trials have shown that the triazoles and echinocandins are efficacious and well tolerated antifungal therapies. Clinical practice guidelines for the management of invasive candidiasis have been published by the European Society for Clinical Microbiology and Infectious Diseases and the Infectious Diseases Society of North America.

Insect feeding preferences on Piperaceae species observed in São Paulo city, Brazil

Piperaceae species have been placed among the basal angiosperm and are adapted to a variety of habitats including moist forests, secondary vegetation and dry high lands. The major anatomical/morphology features are of small trees, vines, and shrubs for Piper species, while the epiphytic and succulent characteristics are predominant forms among Peperomia species. Their secondary chemistry can be mostly represented by amides, phenylpropanoids/lignoids, and chromenes in addition to a phletoria of biosynthetically mixed-origin secondary compounds. Although several amides and lignans are known as insecticides, several phytophagous insects, among which some considered pests of economic importance, have been observed feeding vigorously on Piperaceae species. Herein we describe the feeding preferences of fourteen phytophagous species of Coleoptera, Lepidoptera and Hemiptera over approximately fifty Piperaceae species observed in São Paulo, SP, Brazil, in a long-term basis.

Diagnostic de la maladie coronarienne stable par FFR non invasive, mythe ou réalité [Diagnosis of stable coronary artery disease with non-invasive FFR: myth or reality?].

Decision to revascularize a patient with stable coronary artery disease should be based on the detection of myocardial ischemia. If this decision can be straightforward with significant stenosis or in non-significant stenosis, the decision with intermediate stenosis is far more difficult and require invasive measures of functional impact of coronary stenosis on maximal blood (flow fractional flow reserve=FFR). A recent computer based method has been developed and is able to measure FFR with data acquired during a standard coronary CT-scan (FFRcT). Two recent clinical studies (DeFACTO and DISCOVER-FLOW) show that diagnostic performance of FFRcT was associated with improved diagnostic accuracy versus standard coronary CT-scan for the detection of myocardial ischemia although FFRcT need further development.

Effective Treatment of Invasive Aspergillus fumigatus Infection Using Combinations of Topical and Systemic Antifungals in a Severely Burned Patient.

The authors describe an invasive Aspergillus fumigatus deep-burn wound infection in a severely burned patient that was successfully treated with a combination of topical terbinafine and systemic voriconazole antifungal therapy. To our knowledge, this is the first case report describing the effective control of an invasive deep-burn wound infection using this combination.

Application of the 2008 definitions for invasive fungal diseases to the trial comparing voriconazole versus amphotericin B for therapy of invasive aspergillosis: a collaborative study of the Mycoses Study Group (MSG 05) and the European Organization for Research and Treatment of Cancer Infectious Diseases Group.

BACKGROUND: Strict definition of invasive aspergillosis (IA) cases is required to allow precise conclusions about the efficacy of antifungal therapy. The Global Comparative Aspergillus Study (GCAS) compared voriconazole to amphotericin B (AmB) deoxycholate for the primary therapy of IA. Because predefined definitions used for this trial were substantially different from the consensus definitions proposed by the European Organization for Research and Treatment of Cancer/Mycoses Study Group in 2008, we recategorized the 379 episodes of the GCAS according to the later definitions. METHODS: The objectives were to assess the impact of the current definitions on the classification of the episodes and to provide comparative efficacy for probable/proven and possible IA in patients treated with either voriconazole or AmB. In addition to original data, we integrated the results of baseline galactomannan serum levels obtained from 249 (65.7%) frozen samples. The original response assessment was accepted unchanged. RESULTS: Recategorization allowed 59 proven, 178 probable, and 106 possible IA cases to be identified. A higher favorable 12-week response rate was obtained with voriconazole (54.7%) than with AmB (29.9%) (P < .0001). Survival was higher for voriconazole for mycologically documented (probable/proven) IA (70.2%) than with AmB (54.9%) (P = .010). Higher response rates were obtained in possible IA treated with voriconazole vs AmB with the same magnitude of difference (26.2%; 95% confidence interval [CI], 7.2%-45.3%) as in mycologically documented episodes (24.3%; 95% CI, 11.9%-36.7%), suggesting that possible cases are true IA. CONCLUSIONS: Recategorization resulted in a better identification of the episodes and confirmed the higher efficacy of voriconazole over AmB deoxycholate in mycologically documented IA.

IRM cardiaque: imagerie de référence dans le diagnostic de la myocardite aiguë [Cardiac magnetic resonance in acute myocarditis: a new non-invasive diagnostic gold standard?].

Acute myocarditis was until recently one of the most difficult diagnoses in cardiology. The spectrum of signs and symptoms is very wide, the usual non-invasive tests lack specificity and the myocardial biopsy is only performed in a minority of cases to confirm the diagnosis. Due to its unique ability to directly image myocardial necrosis, fibrosis and oedema, cardiac magnetic resonance (CMR) is now considered the primary tool for noninvasive assessment of patients with suspected myocarditis. CMR is also useful for monitoring disease activity under treatment. Myocarditis has been associated with the development of dilated cardiomyopathy; CMR could play a role in the follow-up of such cases to detect the progression toward a dilatative phenotype. Precise mapping of myocardial lesions with cardiac MRI is invaluable to guide myocardial biopsy and increase its diagnostic yield by improving sensitivity.

Immunogenetics of invasive aspergillosis.

Invasive aspergillosis is one of the most important infections in hematopoietic stem cell transplant recipients, with an incidence rate of 5-15% and an associated mortality of 30-60%. It remains unclear why certain patients develop invasive aspergillosis while others, undergoing identical transplant regimen and similar post transplant immunosuppression, do not. Over the last decade, pattern recognition receptors such as Toll-like receptors (TLRs) and the C-type lectin receptors (CLRs) have emerged as critical components of the innate immune system. By detecting specific molecular patterns from invading microbes and initiating inflammatory and subsequent adaptive immune responses, pattern recognition receptors are strategically located at the molecular interface of hosts and pathogens. Polymorphisms in pattern recognition receptors and downstream signaling molecules have been associated with increased or decreased susceptibility to infections, suggesting that their detection may have an increasing impact on the treatment and prevention of infectious diseases in the coming years. Infectious risk stratification may be particularly relevant for patients with hematologic malignancies, because of the high prevalence and severity of infections in this population. This review summarizes the innate immune mechanisms involved in Aspergillus fumigatus detection and the role of host genetic polymorphisms in susceptibility to invasive aspergillosis.