Anatomy of the antennal dorsal organ in female of Neodryinus typhlocybae (Hymenoptera: Dryinidae): A peculiar sensory structure possibly involved in perception of host vibration

Neodryinus typhlocybae (Hymenoptera: Dryinidae) is a natural enemy of the planthopper Metcalfa pruinosa, which was introduced from North America into Europe and has become established in various regions as a pest species. Vibrational signals play a crucial role in the communication of M. pruinosa, which appears to be exploited by N. typhlocybae. Scanning and transmission electron microscopy have shown that the antennae of N. typhlocybae females have peculiar and complex sensory structures: deep longitudinal grooves that house long sensilla trichodea, termed here “Antennal Dorsal Organs.” Such structures were not present on male antennae. These sensilla extend for the length of the grooves, without contact with the groove cuticle. Their hair shaft is empty and aporous, and inserted into a specialized socket, underneath which there is a cuticular ampulla‐like chamber. Each sensillum is associated with two sensory neurons: one terminates at the proximal end of the dendritic sheath; the other continues into the sensillum sinus and is enclosed in the dendritic sheath. This second sensory neuron then enters the ampulla‐like chamber through the circular opening, and then terminates with a conspicuous tubular body at the shaft base. The possible involvement of this peculiar structure in the context of host recognition mechanism is discussed. J. Morphol. 277:128–137, 2016. © 2015 Wiley Periodicals, Inc.     

Relationship between ornithine decarboxylase activity and hexamethylene bisacetamide-induced differentiation of murine erythroleukemia cells

A transitory increase in ornithine decarboxylase (ODC) activity is shown not to be a prerequisite for the differentiation induced by hexamethylene bisacetamide (HMBA) in murine erythroleukemic (MEL) cells. On the contrary, conditions are described, where inhibition of the ODC activity with alpha-difluoromethyl ornithine (DFMO) stimulated the induced differentiation. Polyamine analysis demonstrated that a reduction in intracellular putrescine and spermidine occurred in MEL cells before commitment to erythrodifferentiation. The presence of DFMO increased the rapidity and the amplitude of these changes. No effect of dexamethasone on these changes in ODC activity or intracellular polyamines was observed.     

The reliability of eye movement quantitative evaluation. I. Saccadic eye movements.

We adopted the estimate of the intraclass coefficient of reliability, R, to evaluate the reliability of saccadic eye movements quantitative analysis. At a one-week interval we recorded refixative saccadic eye movements twice from fifteen healthy subjects by means of the binocular electrooculographic technique. R was computed for the constants and the slopes of the amplitude/duration and the amplitude/peak velocity relationships, for the mean precision values and for the mean latency values adjusted for subject's age. Our data demonstrated that the reliability of saccade parameters is fairly good for the amplitude/peak velocity relationship, good for the precision and very good for the amplitude/duration relationship. Finally, we believe that the normal variability values we obtained can be usefully employed in neurophysiological longitudinal studies not only in normal subjects, but also in pathological condition provided the more reliable parameters and the more adequate strategies to compute normal variability values are chosen.     

Scabies and Impetigo Prevalence and Risk Factors in Fiji: A National Survey

BackgroundScabies is recognised as a major public health problem in many countries, and is responsible for significant morbidity due to secondary bacterial infection of the skin causing impetigo, abscesses and cellulitis, that can in turn lead to serious systemic complications such as septicaemia, kidney disease and, potentially, rheumatic heart disease. Despite the apparent burden of disease in many countries, there have been few large-scale surveys of scabies prevalence or risk factors. We undertook a population-based survey in Fiji of scabies and impetigo to evaluate the magnitude of the problem and inform public health strategies.ConclusionsAs far as we are aware, this is the first national survey of scabies and impetigo ever conducted. We found that scabies occurs at high levels across all age groups, ethnicities, and geographical locations. Improved strategies are urgently needed to achieve control of scabies and its complications in endemic communities.     

Community perspectives on scabies,impetigo and mass drug administration in Fiji: A qualitative study

Scabies is endemic in Fiji and is a significant cause of morbidity. Little is known about the sociocultural beliefs and practices that affect the occurrence of scabies and impetigo, or community attitudes towards the strategy of mass drug administration that is emerging as a public health option for scabies and impetigo control in Fiji and other countries. Data were collected during semi-structured interviews with 33 community members in four locations in Fiji’s Northern Division. Thematic analysis examined participants’ lived experiences of scabies and impetigo; community knowledge and perceptions about scabies and impetigo aetiology and transmission; community-based treatment and prevention measures; and attitudes towards mass drug administration. Many indigenous Fijian (iTaukei) participants noted extensive and ongoing experience of scabies and impetigo among children in their families and communities, but only one participant of Indian descent (Indo-Fijian) identified personal childhood experience of scabies. Scabies and impetigo were perceived as diseases affecting children, impacting on school attendance and families’ quality of sleep. Awareness of scabies and impetigo was considerable, but there were major misconceptions around disease causation and transmission. Traditional remedies were preferred for scabies treatment, followed by biomedicines provided by local health centres and hospitals. Treatment of close household contacts was not prioritised. Attitudes towards mass drug administration to control scabies were mostly positive, although some concerns were noted about adverse effects and hesitation to participate in the planned scabies elimination programme. Findings from this first study to document perspectives and experiences related to scabies and impetigo and their management in the Asia Pacific region illustrate that a community-centred approach to scabies and impetigo is needed for the success of control efforts in Fiji, and most likely in other affected countries. This includes community-based health promotion messaging on the social dynamics of scabies transmission, and a campaign of education and community engagement prior to mass drug administration.     

A Polydnavirus ANK Protein Acts as Virulence Factor by Disrupting the Function of Prothoracic Gland Steroidogenic Cells

Polydnaviruses are obligate symbionts integrated as proviruses in the genome of some ichneumonoid wasps that parasitize lepidopteran larvae. Polydnavirus free viral particles, which are injected into the host at oviposition, express virulence factors that impair immunity and development. To date, most studies have focused on the molecular mechanisms underpinning immunosuppression, whereas how viral genes disrupt the endocrine balance remains largely uninvestigated. Using Drosophila as a model system, the present report analyzes the function of a member of the ankyrin gene family of the bracovirus associated with Toxoneuron nigriceps, a larval parasitoid of the noctuid moth Heliothis virescens. We found that the TnBVank1 expression in the Drosophila prothoracic gland blocks the larval-pupal molt. This phenotype can be rescued by feeding the larvae with 20-hydroxyecdysone. The localization of the TnBVANK1 is restricted to the cytoplasm where it interacts with Hrs and Alix marked endosomes. Collectively, our data demonstrate that the TnBVANK1 protein acts as a virulence factor that causes the disruption of ecdysone biosynthesis and developmental arrest by impairing the vesicular traffic of ecdysteroid precursors in the prothoracic gland steroidogenic cells.     

Strain Dependent Variation of Immune Responses to A. fumigatus: Definition of Pathogenic Species

For over a century microbiologists and immunologist have categorized microorganisms as pathogenic or non-pathogenic species or genera. This definition, clearly relevant at the strain and species level for most bacteria, where differences in virulence between strains of a particular species are well known, has never been probed at the strain level in fungal species. Here, we tested the immune reactivity and the pathogenic potential of a collection of strains from Aspergillus spp, a fungus that is generally considered pathogenic in immuno-compromised hosts. Our results show a wide strain-dependent variation of the immune response elicited indicating that different isolates possess diverse virulence and infectivity. Thus, the definition of markers of inflammation or pathogenicity cannot be generalized. The profound understanding of the molecular mechanisms subtending the different immune responses will result solely from the comparative study of strains with extremely diverse properties.     

Production of Pectolytic Enzymes by Rhizopus stolonifer Sporangiospores After “Lethal” Gamma Irradiation

Irradiated sporangiospores of Rhizopus stolonifer excreted pectolytic enzymes, which hydrolyzed pectin and macerated potato tuber discs, into the suspending medium. Pectin glycosidase, but not pectin methylesterase, activity developed regardless of the amount of radiation the spores had received, unless the dose exceeded about 1 megarad. The ability to produce pectolytic enzymes was found to be more radiation-resistant than the potential for colony formation or the ability to germinate. Spores made incapable, through irradiation, of forming colonies continued to produce pectolytic enzymes after a 6-day period following irradiation treatment.     

In vitro activity of novel in silico‐developed antimicrobial peptides against a panel of bacterial pathogens

Antimicrobial‐peptide‐based therapies could represent a reliable alternative to overcome antibiotic resistance, as they offer potential advantages such as rapid microbicidal activity and multiple activities against a broad spectrum of bacterial pathogens. Three synthetic antimicrobial peptides (AMPs), AMP72, AMP126, and also AMP2041, designed by using ad hoc screening software developed in house, were synthesized and tested against nine reference strains. The peptides showed a partial β‐sheet structure in 10‐mM phosphate buffer. Low cytolytic activity towards both human cell lines (epithelial, endothelial, and fibroblast) and sheep erythrocytes was observed for all peptides. The antimicrobial activity was dose dependent with a minimum bactericidal concentration (MBC) ranging from 0.17 to 10.12 μM (0.4–18.5 µg/ml) for Gram‐negative and 0.94 to 20.65 μM (1.72‐46.5 µg/ml) for Gram‐positive bacteria. Interestingly, in high‐salt environment, the antibacterial activity was generally maintained for Gram‐negative bacteria. All peptides achieved complete bacterial killing in 20 min or less against Gram‐negative bacteria. A linear time‐dependent membrane permeabilization was observed for the tested peptides at 12.5 µg/ml. In a medium containing Mg²⁺ and Ca²⁺, the peptide combination with EDTA restores the antimicrobial activity particularly for AMP2041. Moreover, in combination with anti‐infective agents (quinolones or aminoglycosides) known to bind divalent cation, AMP126 and AMP2041 showed additive activity in comparison with colistin. Our results suggest the following: (i) there is excellent activity against Gram‐negative bacteria, (ii) there is low cytolytic activity, (iii) the presence of a chelating agent restores the antimicrobial activity in a medium containing Mg²⁺ and Ca²⁺, and (iv) the MBC value of the combination AMPs–conventional antibiotics was lower than the MBC of single agents alone. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.