Acoustic camouflage increases with body size and changes with bat echolocation frequency range in a community of nocturnally active Lepidoptera

Body size is an important trait in predator-prey dynamics as it is often linked to detection, as well as the success of capture or escape. Larger prey, for example, often runs higher risk of detection by their predators, which imposes stronger selection on their anti-predator traits compared to smaller prey. Nocturnal Lepidoptera (moths) vary strongly in body size, which has consequences for their predation risk, as bigger moths return stronger echoes for echolocating bats. To compensate for increased predation risk, larger moths are therefore expected to have improved anti-predator defences. Moths are covered by different types of scales, which for a few species are known to absorb ultrasound, thus providing acoustic camouflage. Here, we assessed whether moths differ in their acoustic camouflage in a size-dependent way by focusing on their body scales and the different frequency ranges used by bats. We used a sonar head to measure 3D echo scans of a total of 111 moth specimens across 58 species, from eight different families of Lepidoptera. We scanned all the specimens and related their echo-acoustic target strength to various body size measurements. Next, we removed the scales covering the thorax and abdomen and scanned a subset of specimens again to assess the sound absorptive properties of these scales. Comparing intact specimens with descaled specimens, we found almost all species to absorb ultrasound, reducing detection risk on average by 8%. Furthermore, the sound absorptive capacities of body scales increased with body size suggesting that larger species benefit more from acoustic camouflage. The size-dependent effect of camouflage was in particular pronounced for the higher frequencies (above 29 kHz), with moth species belonging to large-bodied families consequently demonstrating similar target strengths compared to species from small-bodied families. Finally, we found the families to differ in frequency range that provided the largest reduction in detection risk, which may be related to differences in predation pressure and predator communities of these families. In general, our findings have important implications for predator-prey interactions across eco-evolutionary timescales and may suggest that acoustic camouflage played a role in body size evolution of nocturnally active Lepidoptera.

A highly virulent variant of HIV-1 circulating in the Netherlands

We discovered a highly virulent variant of subtype-B HIV-1 in the Netherlands. One hundred nine individuals with this variant had a 0.54 to 0.74 log₁₀ increase (i.e., a ~3.5-fold to 5.5-fold increase) in viral load compared with, and exhibited CD4 cell decline twice as fast as, 6604 individuals with other subtype-B strains. Without treatment, advanced HIV-CD4 cell counts below 350 cells per cubic millimeter, with long-term clinical consequences-is expected to be reached, on average, 9 months after diagnosis for individuals in their thirties with this variant. Age, sex, suspected mode of transmission, and place of birth for the aforementioned 109 individuals were typical for HIV-positive people in the Netherlands, which suggests that the increased virulence is attributable to the viral strain. Genetic sequence analysis suggests that this variant arose in the 1990s from de novo mutation, not recombination, with increased transmissibility and an unfamiliar molecular mechanism of virulence.

Screening for tuberculosis among newly arrived migrants in France. Results from a practice study

Background

Screening of active and latent tuberculosis among migrants is a public health concern but physicians’ practices are poorly known. The study aimed to evaluate physicians’ practices in France.

Methods

A national survey of physicians’ practices about infectious diseases prevention among migrants was conducted in 2017-2018 and broadcasted by several scientific societies.

Results

In total, 367 physicians answered; 53.1% were primary care physicians, 34.3% “TB involved physicians”, and 85.5% were involved daily with migrants. Screening by chest X ray is recommended by 84.8%, 71.9% and 38.4% of participants for migrants from high- (>100 cases/100,000 p.a.), medium- (> 50/100,000), and low-incidence countries respectively. One physician in two declares considering migration conditions in his/her decision of screening migrants from low incidence countries. Primary care physicians are less likely to offer screening (aOR= 0.21[0.09-0.48], p < 0.001). About screening prescription, only 55.6% consider it their responsibility. TB control centres are designated by 56.7% of respondents. Concerning screening for latent tuberculosis infection (LTBI), 61.8% and 34.0% offered screening for children under the age of 15 and for all migrants (adults and children) from high incidence countries respectively; physicians working in Paris and its region being less likely to offer it (aOR=0.45 [0.28-0.71], p = 0.001 and aOR=0.43 [0.27-0.69] p = 0.001 respectively). Among those screening children, 88.1% recommend treatment if facing a positive result, most often with a 3-month isoniazid rifampicin double therapy, and 11.4% offer follow up alone.

Conclusions

Physicians’ practices in France regarding screening of tuberculosis among migrants are heterogeneous. Which population should be targeted for LTBI screening remains unclear in the context of contradictory national and international recommendations. The results of our study raise the issue of knowledge, and adherence to these guidelines.

Key messages

Physicians’ practices in France concerning active and latent tuberculosis screening among newly arrived migrants are heterogeneous. Many physicians involved in migrants’ care ignore or do not adhere to current national guidelines, especially concerning LTBI screening among newly arrived migrants.

[General medical practice and medicinal voluntary termination of pregnancy in Grand Est, France]

BACKGROUND

Access to VTOP (Voluntary Termination of Pregnancy) is a national priority in France. Once legalized in 1975, several laws contributed to improve access to VTOP, such as the 2004 family planning law which enabled urban practitioners to carry out orthogenic work. This law was supplemented by the 2016 health care modernization act. On the whole, the organization for VTOP access in the Grand Est region, complies with legislation and recommendations. However, private practitioners contribute little to this activity. Since there are very few gynecologists in certain areas (whether private or hospital practitioners), general practitioners seem to be the first line actors. This study aims at describing the orthogenic work of urban, government-regulated general practitioners, in the Grand Est region of France.

MATERIAL AND METHOD

Data were collected from semi-directive interviews with the set of the government-regulated general practitioners doing family planning work in the Grand Est region.

RESULTS

Out of the fifteen doctors who were interviewed, twelve actually suggested family planning work to their patients, and out of those twelve, seven practiced it in reality. What comes out is that the main motivation of professionals was to improve access to VTOP. Besides, they also mentioned the importance of being able to answer a real demand from their patients as well as an interest in gynecology. Hence the professionals' practice both benefits from services provided to their patients and from a diversification of their work, even though they regret that the value of this time-consuming procedure is not recognized. This study also brings out that although these medical acts were individualized and allowed better confidentiality for the patient, the risk for complications and home birth remained an obstacle. Finally, it emerges that the whole set of recommendations was not always implemented.

DISCUSSION

Urban family planning, performed by general practitioners, seems to be a major line to focus on for better timeliness and quality of care. However, some obstacles have been identified such as its specificity, its time-consuming aspect, its lack of status, as well as the difficulty to comply with recommendations.

CONCLUSION

The development of this practice is necessary to maintain an appropriate response to VTOP but actions to remove certain obstacles have to be carried out.

Validation of the PECARN clinical decision rule for children with minor head trauma: a French multicenter prospective study

BACKGROUND

To date, the Pediatric Emergency Care Applied Research Network (PECARN) rule for identifying children who are at very low risk of clinically-important traumatic brain injuries after minor head trauma has not been validated prospectively in an independent population. Our goal was to evaluate the diagnostic performance of the PECARN clinical decision rule in a French pediatric population in multiple clinical settings.

METHODS

We conducted a multicenter, prospective, non-interventional cohort study of patients with minor head trauma who presented to three emergency departments in France. We enrolled patients younger than 16 years of age seeking a consultation within 24 h of head trauma with Glasgow Coma Scale scores of 14-15.

RESULTS

During the study period, we included 1499 children of which 421 (28 %) were under 2 years of age, and 955 (64 %) were male. A cranial computed tomography (CT) scan was performed on 76 patients (5.1 %). Of the 1499 included patients, 9 children (0.6 %) had a clinically-important traumatic brain injury, and none were classified as very low risk by the PECARN rule. In our study, the sensitivity of this clinical decision rule was 100 % (95 % CI 66.4 to 100 %), the specificity was 69.9 % (95 % CI 67.5 to 72.2 %) and the negative predictive value was 100 % (95 % CI 99.7 to 100 %).

DISCUSSION

Our study confirmed the good predictive performances of the PECARN clinical decision rule for minor head trauma in children. The PECARN rule performed similarly to our study and to its internal validation study.

CONCLUSIONS

We conducted an external validation study of the PECARN clinical decision rule for the detection of clinically-important traumatic brain injuries in children with minor head trauma, according to the methodological standards. The PECARN rule successfully identified all patients with clinically-important traumatic brain injuries, with a limited use of CT scans. Conducting a broad validation study with a large cohort is a prerequisite to provide sufficient statistical power before authorizing its implementation and generalization.

TRIAL REGISTRATION

This study has been registered in ClinicalTrials.gov with identifier number: NCT02752711 on April 27, 2016.

Human herpes virus co-infection is associated with mortality in HIV-negative patients with Pneumocystis jirovecii pneumonia

The purpose of this investigation was to characterize the management and prognosis of severe Pneumocystis jirovecii pneumonia (PJP) in human immunodeficiency virus (HIV)-negative patients. An observational cohort study of HIV-negative adults with PJP documented by bronchoalveolar lavage (BAL) through Gomori-Grocott staining or immunofluorescence, admitted to one intensive care unit (ICU) for acute respiratory failure, was undertaken. From 1990 to 2010, 70 patients (24 females, 46 males) were included, with a mean age of 58.6 ± 18.3 years. The mean Simplified Acute Physiology Score (SAPS)-II was 36.9 ± 20.4. Underlying conditions included hematologic malignancies (n = 21), vasculitis (n = 13), and solid tumors (n = 13). Most patients were receiving systemic corticosteroids (n = 63) and cytotoxic drugs (n = 51). Not a single patient received trimethoprim-sulfamethoxazole as PJP prophylaxis. Endotracheal intubation (ETI) was required in 42 patients (60.0 %), including 38 with acute respiratory distress syndrome (ARDS). In-ICU mortality was 52.9 % overall, reaching 80.9 % and 86.8 %, respectively, for patients who required ETI and for patients with ARDS. In the univariate analysis, in-ICU mortality was associated with SAPS-II (p = 0.0131), ARDS (p < 0.0001), shock (p < 0.0001), and herpes simplex virus (HSV) or cytomegalovirus (CMV) on BAL (p = 0.0031). In the multivariate analysis, only ARDS was associated with in-ICU mortality (odds ratio [OR] 23.4 [4.5-121.9], p < 0.0001). PJP in non-HIV patients remains a serious disease with high in-hospital mortality. Pulmonary co-infection with HSV or CMV may contribute to fatal outcome.

Can virtual fences be used to control grazing sheep?

Virtual fences (VF) are based on sensory cues delivered to domestic animals with the aim of controlling their spatial behaviour without any physical barrier. VF represent an approach for controlling the distribution of free-ranging large herbivores in large rangeland areas where the implementation of human control or the use of physical fencing is made impossible by their cost, environmental concerns or specific regulations. The potential of using VF for sheep was investigated by studying the spatial behaviour of groups of 5 or 32 ewes submitted to a commercial animal-borne VF device aimed at containing them in a defined area in a series of experiments. All tests were performed in pasture alleys virtually divided in their centre by a 4-m-wide warning/punishment zone). The ewes were introduced on one side of the zone, the other side being made attractive by the presence of tall grass (feed attractant), the presence of peers (social attractant) or being made unattractive by the presence of short grass (same feed as in the alley). In a first experiment, ewes were trained in groups of 5 with a feed attractant, following a 3-stage procedure: 30-min adaptation, 90-min training with a visual cue (three white strings above the wire of the VF) and 30-min test without a visual cue. In a second experiment, the test stage was repeated for each group with feed, social and zero attractants. In a third experiment, the test with feed attractant was performed with groups of 32 ewes comprising previously trained and equipped ewes mixed in different percentages of trained: naïve (untrained and unequipped) ewes (100 : 0, 75 : 25, 50 : 50 and 0 : 100%). One year later, this test was repeated with a feed attractant either close (30 m) or far (60 m) from the punishment zone. By increasing the distance to the feed attractant, it was anticipated that this would stimulate the conflict of motivation between feed and peers. Ewes learned readily the concept of VF after a couple of contacts with the punishment zone. In the second experiment in the test with a social attractant, a few trained ewes penetrated the VF to re-associate with peers located in the pen opposite the VF. Expression of the behaviour to challenge or cross the punishment zone differed widely among individuals. In mixed groups, naïve ewes crossed the punishment zone and lead part of their trained peers across the punishment zone, regardless of the distance of the feed attractant from the punishment zone. The results suggest that VF can be used to alter the distribution of grazing sheep within large fenced areas although they cannot replace conventional fences for absolute control.

Incidence and prognostic impact of c-Kit, FLT3, and Ras gene mutations in core binding factor acute myeloid leukemia (CBF-AML)

In core binding factors (CBF) acute myeloid leukemia (AML), the disruption of CBFalpha/beta genes impairs normal hematopoietic differentiation and is supposed to cooperate with additional mutations promoting proliferation. The incidence and the prognosis of receptor tyrosine kinase (RTK) c-Kit and FLT3 mutations and Ras mutations were evaluated in 103 pediatric and adult patients with CBF-AML. c-Kit mutations were present in 17% patients. c-Kit exon 8 mutations were more frequent in inv(16) than in t(8;21) subset (20 versus 6%). Only one patient had FLT3-ITD but FLT3-D835 was as frequent as reported in AML population (7%). Ras mutations were significantly more frequent in inv(16) than in t(8;21) subset (36 versus 8%, P=0.001). RTK mutations were associated with a higher white blood cell count (WBC) (36 versus 21 G/L, P=0.05). FLT3 mutations were significantly associated with a shorter EFS and survival (P<0.0001 and P=0.0002) owing to an excess of early events. c-Kit mutations were associated with a shorter EFS and RFS (P=0.002 and P=0.003) in t(8;21) but not inv(16) patients. As previously observed, Ras mutations did not affect prognosis. Screening for RTK mutations may help to identify patients with a more adverse outcome and thus susceptible to benefit from intensified protocols or RTK inhibitors.

Prognostic value of real-time quantitative PCR (RQ-PCR) in AML with t(8;21)

Despite the favorable prognosis of patients with acute myeloid leukemia (AML) with t(8;21)(q22;q22) translocation, relapses still occur in about 30% of the cases but no initial factors can strongly predict the risk of relapse. Several recent studies suggest that monitoring minimal residual disease (MRD) may identify patients at risk of relapse. We prospectively monitored AML1-ETO rearrangement by real-time quantitative PCR (RQ-PCR) in 21 patients uniformly treated in our center. Blood (PB) and bone marrow (BM) samples were collected during and after therapy. At diagnosis, levels of AML1-ETO transcript showed large variations and there was a trend for a higher relapse rate in patients with high pretreatment expression levels (P=0.065). After induction therapy, absolute transcript levels (below 10(-3), compared to Kasumi cell line), or a greater than 3 log decrease by comparison to diagnosis levels, were significant predictors of the absence of relapse (P=0.02 and P=0.02, respectively). MRD levels after consolidation therapy were also significant indicators of relapse (P=10(-5)). Comparison of BM and PB samples showed similar sensitivity for detecting AML1-ETO transcript. In conclusion, RQ-PCR appears to be an early predictive factor of the relapse risk in AML with t(8;21). PB samples can be used adequately to evaluate the level of MRD by this technique.

CEBPA point mutations in hematological malignancies

The CCAAT/enhancer-binding protein-alpha (CEBPA) is a transcription factor strongly implicated in myelopoiesis through control of proliferation and differentiation of myeloid progenitors. Recently, several works have reported the presence of CEBPA-acquired mutations in hematological malignancies. In this work, we analyzed characteristics of mutations and their correlation with disease characteristics described in previous studies. In the 1175 patients reported, 146 CEBPA mutations were identified in 96 patients. Mutations were found in the whole gene sequence, but cluster regions were clearly identified. Furthermore, two categories of mutations were reported: out-of-frame ins/del often in the N-terminal region, and in-frame ins/del often in the C-terminal region. CEBPA mutations were reported exclusively in acute myeloid leukemia (AML) (according to WHO classification criteria) and mutated patients preferentially belonged to M1, M2 and M4 FAB subtypes. All but one case belonged to the 'intermediate' prognostic subgroup of MRC classification. In the absence of poor prognostic factors, patients with CEBPA mutation had favorable outcome, very similar to that of the t(8;21), inv(16), t(15;17) subgroup. Systematic analysis of CEBPA mutations, in addition to that of alterations in master genes of hematopoiesis, may be useful to assess the prognosis of AML particularly in patients belonging to the 'intermediate' prognostic subgroup.

Identification of mariner-like elements from the root-knot nematode Meloidogyne spp

The Meloidogyne species are agriculturally important pests widespread in the world. These polyphagous endoparasitic nematodes possess an astonishing ability to bypass the plant resistance genes in few generations. However, the genes and mechanisms involved in this molecular determinism are not yet known. Except cytogenetic and cytotaxonomic studies, few data are available concerning their genome. There is therefore an important need of molecular tools for genetic investigation of their virulence character and other aspects of host-pathogen interactions. In that respect, the presence of mariner-like-elements (MLEs) was assessed in these endoparasitic nematodes by a polymerase chain reaction (PCR) assay using degenerate primers designed from two conserved regions of the mariner transposase open reading frame (ORF). Four Meloidogyne species of the five tested revealed the presence of MLEs in their genome. Southern blot analysis indicated that sequences hybridizing to the mariner transposase-like PCR clones occur at a moderate to low copy number in the different Meloidogyne spp. genomes. The phylogenetic analysis show that the Meloidogyne MLEs may form new subfamilies of mariner. Moreover, five PCR clones were shown to possess a continuous ORF suggesting the presence of putative transposase-like coding regions.

Unusual and strongly structured sequence variation in a complex satellite DNA family from the nematode Meloidogyne chitwoodi

An AluI satellite DNA family has been isolated in the genome of the root-knot nematode Meloidogyne chitwoodi. This repeated sequence was shown to be present at approximately 11,400 copies per haploid genome, and represents about 3.5% of the total genomic DNA. Nineteen monomers were cloned and sequenced. Their length ranged from 142 to 180 bp, and their A + T content was high (from 65.7 to 79.1%), with frequent runs of As and Ts. An unexpected heterogeneity in primary structure was observed between monomers, and multiple alignment analysis showed that the 19 repeats could be unambiguously clustered in six subfamilies. A consensus sequence has been deduced for each subfamily, within which the number of positions conserved is very high, ranging from 86.7% to 98.6%. Even though blocks of conserved regions could be observed, multiple alignment of the six consensus sequences did not enable the establishment of a general unambiguous consensus sequence. Screening of the six consensus sequences for evidence of internal repeated subunits revealed a 6-bp motif (AAATTT), present in both direct and inverted orientation. This motif was found up to nine times in the consensus sequences, also with the occurrence of degenerated subrepeats. Along with the meiotic parthenogenetic mode of reproduction of this nematode, such structural features may argue for the evolution of this satellite DNA family either (1) from a common ancestral sequence by amplification followed by mechanisms of sequence divergence, or (2) through independent mutations of the ancestral sequence in isolated amphimictic nematode populations and subsequent hybridization events. Overall, our results suggest the ancient origin of this satellite DNA family, and may reflect for M. chitwoodi a phylogenetic position close to the ancestral amphimictic forms of root-knot nematodes.