Effects of Levetiracetam and Sulthiame on EEG in benign epilepsy with centrotemporal spikes: A randomized controlled trial

PURPOSE

BECTS (benign childhood epilepsy with centrotemporal spikes) is associated with characteristic EEG findings. This study examines the influence of anti-convulsive treatment on the EEG.

METHODS

In a randomized controlled trial including 43 children with BECTS, EEGs were performed prior to treatment with either Sulthiame or Levetiracetam as well as three times under treatment. Using the spike-wave-index, the degree of EEG pathology was quantified. The EEG before and after initiation of treatment was analyzed. Both treatment arms were compared and the EEG of the children that were to develop recurrent seizures was compared with those that were successfully treated.

RESULTS

Regardless of the treatment agent, the spike-wave-index was reduced significantly under treatment. There were no differences between the two treatment groups. In an additional analysis, the EEG characteristics of the children with recurrent seizures differed statistically significant from those that did not have any further seizures.

CONCLUSION

Both Sulthiame and Levetiracetam influence the EEG of children with BECTS. Persistent EEG pathologies are associated with treatment failures.

Regular Wounding in a Natural System: Bacteria Associated With Reproductive Organs of Bedbugs and Their Quorum Sensing Abilities

During wounding, tissues are disrupted so that bacteria can easily enter the host and trigger a host response. Both the host response and bacterial communication can occur through quorum sensing (QS) and quorum sensing inhibition (QSI). Here, we characterize the effect of wounding on the host-associated bacterial community of the bed bug. This is a model system where the male is wounding the female during every mating. Whereas several aspects of the microbial involvement during wounding have been previously examined, it is not clear to what extent QS and QSI play a role. We find that the microbiome differs depending on mating and feeding status of female bedbugs and is specific to the location of isolation. Most organs of bedbugs harbor bacteria, which are capable of both QS and QSI signaling. By focusing on the prokaryotic quorum communication system, we provide a baseline for future research in this unique system. We advocate the bedbug system as suitable for studying the effects of bacteria on reproduction and for addressing prokaryote and eukaryote communication during wounding.

Neuropeptidomics of the Bed Bug Cimex lectularius

The bed bug Cimex lectularius is a globally distributed human ectoparasite with fascinating biology. It has recently acquired resistance against a broad range of insecticides, causing a worldwide increase in bed bug infestations. The recent annotation of the bed bug genome revealed a full complement of neuropeptide and neuropeptide receptor genes in this species. With regard to the biology of C. lectularius, neuropeptide signaling is especially interesting because it regulates feeding, diuresis, digestion, as well as reproduction and also provides potential new targets for chemical control. To identify which neuropeptides are translated from the genome-predicted genes, we performed a comprehensive peptidomic analysis of the central nervous system of the bed bug. We identified in total 144 different peptides from 29 precursors, of which at least 67 likely present bioactive mature neuropeptides. C. lectularius corazonin and myosuppressin are unique and deviate considerably from the canonical insect consensus sequences. Several identified neuropeptides likely act as hormones, as evidenced by the occurrence of respective mass signals and immunoreactivity in neurohemal structures. Our data provide the most comprehensive peptidome of a Heteropteran species so far and in comparison suggest that a hematophageous life style does not require qualitative adaptations of the insect peptidome.

Autofluorescence lifetime variation in the cuticle of the bedbug Cimex lectularius

The decay time of the fluorescence of excited molecules, called fluorescence lifetime, can provide information about the cuticle composition additionally to widely used spectral characteristics. We compared autofluorescence lifetimes of different cuticle regions in the copulatory organ of females of the bedbug, Cimex lectularius. After two-photon excitation at 720 nm, regions recently characterised as being rich in resilin showed a longer bimodal distribution of the mean autofluorescence lifetime τ_m (tau-m) at 0.4 ns and 1.0-1.5 ns, while resilin-poor sites exhibited a unimodal pattern with a peak around 0.8 ns. The mean lifetime, and particularly its second component, can be useful to distinguish resilin-rich from resilin-poor parts of the cuticle. The few existing literature data suggest that chitin is unlikely responsible for the main autofluorescent component observed in the resilin-poor areas in our study and that melanin requires further scrutiny. Autofluorescence lifetime measurements can help to characterise properties of the arthropod cuticle, especially when coupled with multiphoton excitation to allow for deeper tissue penetration.

Sperm metabolism is altered during storage by female insects: evidence from two-photon autofluorescence lifetime measurements in bedbugs

We explore the possibility of characterizing sperm cells without the need to stain them using spectral and fluorescence lifetime analyses after multi-photon excitation in an insect model. The autofluorescence emission spectrum of sperm of the common bedbug, Cimex lectularius, was consistent with the presence of flavins and NAD(P)H. The mean fluorescence lifetimes showed smaller variation in sperm extracted from the male (tau m, τm = 1.54-1.84 ns) than in that extracted from the female sperm storage organ (tau m, τm = 1.26-2.00 ns). The fluorescence lifetime histograms revealed four peaks. These peaks (0.18, 0.92, 2.50 and 3.80 ns) suggest the presence of NAD(P)H and flavins and show that sperm metabolism can be characterized using fluorescence lifetime imaging. The difference in fluorescence lifetime variation between the sexes is consistent with the notion that female animals alter the metabolism of sperm cells during storage. It is not consistent, however, with the idea that sperm metabolism represents a sexually selected character that provides females with information about the male genotype.

Heritability, evolvability, phenotypic plasticity and temporal variation in sperm-competition success of Drosophila melanogaster

Sperm-competition success (SCS) is seen as centrally important for evolutionary change: superior fathers sire superior sons and thereby inherit the traits that make them superior. Additional hypotheses, that phenotypic plasticity in SCS and sperm ageing explain variation in paternity, are less considered. Even though various alleles have individually been shown to be correlated with variation in SCS, few studies have addressed the heritability, or evolvability, of overall SCS. Those studies that have addressed found low or no heritability and have not examined evolvability. They have further not excluded phenotypic plasticity, and temporal effects on SCS, despite their known dramatic effects on sperm function. In Drosophila melanogaster, we found that both standard components of sperm competition, sperm defence and sperm offence, showed nonsignificant heritability across several offspring cohorts. Instead, our analysis revealed, for the first time, the existence of phenotypic plasticity in SCS across an extreme environment (5% CO2 ), and an influence of sperm ageing. Evolvability of SCS was substantial for sperm defence but weak for sperm offence. Our results suggest that the paradigm of explaining evolution by sperm competition is more complex and will benefit from further experimental work on the heritability or evolvability of SCS, measuring phenotypic plasticity, and separating the effects of sperm competition and sperm ageing.

An Ecology of Sperm: Sperm Diversification by Natural Selection

Using basic ecological concepts, we introduce sperm ecology as a framework to study sperm cells. First, we describe environmental effects on sperm and conclude that evolutionary and ecological research should not neglect the overwhelming evidence presented here (both in external and internal fertilizers and in terrestrial and aquatic habitats) that sperm function is altered by many environments, including the male environment. Second, we determine that the evidence for sperm phenotypic plasticity is overwhelming. Third, we find that genotype-by-environment interaction effects on sperm function exist, but their general adaptive significance (e.g., local adaptation) awaits further research. It remains unresolved whether sperm diversification occurs by natural selection acting on sperm function or by selection on male and female microenvironments that enable optimal plastic performance of sperm (sperm niches). Environmental effects reduce fitness predictability under sperm competition, predict species distributions under global change, explain adaptive behavior, and highlight the role of natural selection in behavioral ecology and reproductive medicine.

Copulatory wounding and traumatic insemination

Copulatory wounding (CW) is widespread in the animal kingdom, but likely underreported because of its cryptic nature. We use four case studies (Drosophila flies, Siphopteron slugs, Cimex bugs, and Callosobruchus beetles) to show that CW entails physiological and life-history costs, but can evolve into a routine mating strategy that, in some species, involves insemination through the wound. Although interspecific variation in CW is documented, few data exist on intraspecific and none on individual differences. Although defensive mechanisms evolve in the wound recipient, our review also indicates that mating costs in species with CW are slightly higher than in other species. Whether such costs are dose- or frequency-dependent, and whether defense occurs as resistance or tolerance, decisively affects the evolutionary outcome. In addition to sexual conflict, CW may also become a model system for reproductive isolation. In this context, we put forward a number of predictions, including (1) occasional CW is more costly than routine CW, (2) CW is more costly in between- than within-population matings, and (3) in the presence of CW, selection may favor the transmission of sexually transmitted diseases if they induce resource allocation. Finally, we outline, and briefly discuss, several medical implications of CW in humans.

Reduction of female copulatory damage by resilin represents evidence for tolerance in sexual conflict

Intergenomic evolutionary conflicts increase biological diversity. In sexual conflict, female defence against males is generally assumed to be resistance, which, however, often leads to trait exaggeration but not diversification. Here, we address whether tolerance, a female defence mechanism known from interspecific conflicts, exists in sexual conflict. We examined the traumatic insemination of female bed bugs via cuticle penetration by males, a textbook example of sexual conflict. Confocal laser scanning microscopy revealed large proportions of the soft and elastic protein resilin in the cuticle of the spermalege, the female defence organ. Reduced tissue damage and haemolymph loss were identified as adaptive female benefits from resilin. These did not arise from resistance because microindentation showed that the penetration force necessary to breach the cuticle was significantly lower at the resilin-rich spermalege than at other cuticle sites. Furthermore, a male survival analysis indicated that the spermalege did not impose antagonistic selection on males. Our findings suggest that the specific spermalege material composition evolved to tolerate the traumatic cuticle penetration. They demonstrate the importance of tolerance in sexual conflict and genitalia evolution, extend fundamental coevolution and speciation models and contribute to explaining the evolution of complexity. We propose that tolerance can drive trait diversity.

Outbreeding effects in an inbreeding insect, Cimex lectularius

In some species, populations with few founding individuals can be resilient to extreme inbreeding. Inbreeding seems to be the norm in the common bed bug, Cimex lectularius, a flightless insect that, nevertheless, can reach large deme sizes and persist successfully. However, bed bugs can also be dispersed passively by humans, exposing inbred populations to gene flow from genetically distant populations. The introduction of genetic variation through this outbreeding could lead to increased fitness (heterosis) or be costly by causing a loss of local adaptation or exposing genetic incompatibility between populations (outbreeding depression). Here, we addressed how inbreeding within demes and outbreeding between distant populations impact fitness over two generations in this re-emerging public health pest. We compared fitness traits of families that were inbred (mimicking reproduction following a founder event) or outbred (mimicking reproduction following a gene flow event). We found that outbreeding led to increased starvation resistance compared to inbred families, but this benefit was lost after two generations of outbreeding. No other fitness benefits of outbreeding were observed in either generation, including no differences in fecundity between the two treatments. Resilience to inbreeding is likely to result from the history of small founder events in the bed bug. Outbreeding benefits may only be detectable under stress and when heterozygosity is maximized without disruption of coadaptation. We discuss the consequences of these results both in terms of inbreeding and outbreeding in populations with genetic and spatial structuring, as well as for the recent resurgence of bed bug populations.

Human-facilitated metapopulation dynamics in an emerging pest species, Cimex lectularius

The number and demographic history of colonists can have dramatic consequences for the way in which genetic diversity is distributed and maintained in a metapopulation. The bed bug (Cimex lectularius) is a re-emerging pest species whose close association with humans has led to frequent local extinction and colonization, that is, to metapopulation dynamics. Pest control limits the lifespan of subpopulations, causing frequent local extinctions, and human-facilitated dispersal allows the colonization of empty patches. Founder events often result in drastic reductions in diversity and an increased influence of genetic drift. Coupled with restricted migration, this can lead to rapid population differentiation. We therefore predicted strong population structuring. Here, using 21 newly characterized microsatellite markers and approximate Bayesian computation (ABC), we investigate simplified versions of two classical models of metapopulation dynamics, in a coalescent framework, to estimate the number and genetic composition of founders in the common bed bug. We found very limited diversity within infestations but high degrees of structuring across the city of London, with extreme levels of genetic differentiation between infestations (F_ST = 0.59). ABC results suggest a common origin of all founders of a given subpopulation and that the numbers of colonists were low, implying that even a single mated female is enough to found a new infestation successfully. These patterns of colonization are close to the predictions of the propagule pool model, where all founders originate from the same parental infestation. These results show that aspects of metapopulation dynamics can be captured in simple models and provide insights that are valuable for the future targeted control of bed bug infestations.

GATA1s induces hyperproliferation of eosinophil precursors in Down syndrome transient leukemia

Transient leukemia (TL) is evident in 5–10% of all neonates with Down syndrome (DS) and associated with N-terminal truncating GATA1-mutations (GATA1s). Here we report that TL cell clones generate abundant eosinophils in a substantial fraction of patients. Sorted eosinophils from patients with TL and eosinophilia carried the same GATA1s-mutation as sorted TL-blasts, consistent with their clonal origin. TL-blasts exhibited a genetic program characteristic of eosinophils and differentiated along the eosinophil lineage in vitro. Similarly, ectopic expression of Gata1s, but not Gata1, in wild-type CD34⁺-hematopoietic stem and progenitor cells induced hyperproliferation of eosinophil promyelocytes in vitro. While GATA1s retained the function of GATA1 to induce eosinophil genes by occupying their promoter regions, GATA1s was impaired in its ability to repress oncogenic MYC and the pro-proliferative E2F transcription network. ChIP-seq indicated reduced GATA1s occupancy at the MYC promoter. Knockdown of MYC, or the obligate E2F-cooperation partner DP1, rescued the GATA1s-induced hyperproliferative phenotype. In agreement, terminal eosinophil maturation was blocked in Gata1^Δe2 knockin mice, exclusively expressing Gata1s, leading to accumulation of eosinophil precursors in blood and bone marrow. These data suggest a direct relationship between the N-terminal truncating mutations of GATA1 and clonal eosinophilia in DS patients.

The Entomological Institute of the Waffen-SS: evidence for offensive biological warfare research in the third Reich

In January 1942, Heinrich Himmler, head of the Schutzstaffel (SS) and police in Nazi Germany, ordered the creation of an entomological institute to study the physiology and control of insects that inflict harm to humans. Founded in the grounds of the concentration camp at Dachau, it has been the focus of previous research, notably into the question of whether it was involved in biological warfare research. This article examines research protocols by the appointed leader Eduard May, presented here for the first time, which confirm the existence of an offensive biological warfare research programme in Nazi Germany.