Azadirachtin impact on mate choice, female sexual receptivity and male activity in Drosophila melanogaster (Diptera: Drosophilidae).

Azadirachtin, a neem compound (Azadirachta indica) with medical and anti-insect properties, is one the most successful botanical pesticides in agricultural use. However, its controversial impact on non-targeted species and its mechanism of action need to be clarified. In addition, Azadirachtin impact on pre- and post-mating traits remains largely undocumented. The current study examined the effects of Azadirachtin on Drosophila melanogaster as a non-target and model species. Azadirachtin was applied topically at its LD50 (0.63µg) on the day of adult emergence and its effect was evaluated on several traits of reproductive behavior: mate choice, male activity, female sexual receptivity, sperm storage and female sterility. In choice and no choice conditions, only male treatment reduced mating probability. Female treatment impaired mating probability only when males had the choice. Males' mating ability may have been impaired by an effect of the treatment on their mobility. Such an effect was observed in the actimeter, which revealed that treated males were less active than untreated ones, and this effect persisted over 8days. Azadirachtin treatment had, however, no effect on the nycthemeral rhythm of those males. Even when mating occurred, Azadirachtin treatment impaired post-mating responses especially when females or both sexes were treated: remating probability increases and female fertility (presence of larvae) decreases. No impairment was observed on the efficiency of mating, evaluated by the presence of sperm in the spermatheca or the ventral receptacle. Male treatment only had no significant effect on these post-mating responses. These findings provide clear evidence that Azadirachtin alters the reproductive behavior of both sexes in D. melanogaster via mating and post-mating processes.

The environmental genomics of metazoan thermal adaptation.

Continued and accelerating change in the thermal environment places an ever-greater priority on understanding how organisms are going to respond. The paradigm of 'move, adapt or die', regarding ways in which organisms can respond to environmental stressors, stimulates intense efforts to predict the future of biodiversity. Assuming that extinction is an unpalatable outcome, researchers have focussed attention on how organisms can shift in their distribution to stay in the same thermal conditions or can stay in the same place by adapting to a changing thermal environment. How likely these respective outcomes might be depends on the answer to a fundamental evolutionary question, namely what genetic changes underpin adaptation to the thermal environment. The increasing access to and decreasing costs of next-generation sequencing (NGS) technologies, which can be applied to both model and non-model systems, provide a much-needed tool for understanding thermal adaptation. Here we consider broadly what is already known from non-NGS studies about thermal adaptation, then discuss the benefits and challenges of different NGS methodologies to add to this knowledge base. We then review published NGS genomics and transcriptomics studies of thermal adaptation to heat stress in metazoans and compare these results with previous non-NGS patterns. We conclude by summarising emerging patterns of genetic response and discussing future directions using these increasingly common techniques.

Environmental risk factors for haemorrhagic fever with renal syndrome in a French new epidemic area.

In France, haemorrhagic fever with renal syndrome (HFRS) is endemic along the Belgian border. However, this rodent-borne zoonosis caused by the Puumala virus has recently spread south to the Franche-Comté region. We investigated the space-time distribution of HFRS and evaluated the influence of environmental factors that drive the hantavirus reservoir abundance and/or the disease transmission in this area. A scan test clearly indicated space-time clustering, highlighting a single-year (2005) epidemic in the southern part of the region, preceded by a heat-wave 2 years earlier. A Bayesian regression approach showed an association between a variable reflecting biomass (normalized difference vegetation index) and HFRS incidence. The reasons why HFRS cases recently emerged remain largely unknown, and climate parameters alone do not reliably predict outbreaks. Concerted efforts that combine reservoir monitoring, surveillance, and investigation of human cases are warranted to better understand the epidemiological patterns of HFRS in this area.

[Renal-pleural fistula after radiofrequency ablation of renal tumor in VHL patient]. / Fistule réno-pleurale après radiofréquence d'une tumeur rénale chez une patiente avec un VHL.

Radiofrequency is a minimally invasive therapy allowing tumor destruction by applying physical means to the core of the lesion. There is a particular indication for the hereditary already surgically treated renal carcinomas like Von Hippel-Lindau's disease. We present a case of renal-pleural fistula developed after a percutaneous radiofrequency ablation under computed tomography (CT) guidance of a renal tumor in a VHL female patient with a renal cell carcinoma of the upper pole of the left kidney. The kidney manifestations begin at 20-year-old with the appearance of cystic lesion at the lower pole of the left kidney. At 30-year-old, a computed tomography study revealed a solid lesion arising from a cyst. The patient underwent a partial nephrectomy by flank incision. Follow-up studies discovered three solid lesions of the upper pole of the left kidney. The patient undertook a radiofrequency ablation of these lesions. Follow-up control showed a contrast enhancement of one of the three lesions treated. Under this condition another course of RF was performed, complicated by a renal-pleural fistula. A conservative management of this iatrogenic fistula was attempted combining a water restriction and the insertion of a ureteral catheter. Three weeks were necessary until the fistula completely regress.

Detection of first gammaherpesvirus sequences in Central African bats.

Herpesviruses have been identified in many species; however, relatively few bat herpesvirus are known, considering the enormous diversity of bats. We used consensus PCR to test bats from the Republic of the Congo and found DNA of two different novel bat herpesviruses. One was detected in a Pipistrellus nanulus, the other in a Triaenops persicus bat and both resemble gammaherpesviruses. On the amino acid level, the amplified sequences differ by 55% from each other, and by 27% and 25% from the next closest known viruses. The findings point towards the diversity of herpesviruses in Central African bats.

Analysis of adenovirus DNA detected in rodent species from the Democratic Republic of the Congo indicates potentially novel adenovirus types.

Different species of adenoviruses (AdVs) infect humans and animals and are known for their role as pathogens, especially in humans, with animals, primarily rodents, often serving as model systems. However, although we know over 100 types of human AdVs, we know comparatively little about the diversity of animal AdVs. Due to the fact that rodents are the most diverse family of mammals and a standard model system for human disease, we set out to sample African rodents native to the Democratic Republic of the Congo and test them for AdV DNA using a semi-nested consensus PCR. A total of 775 animals were tested, and viral DNA was detected in four of them. The AdV DNA found belongs to three different AdVs, all being closely related to murine adenovirus 2 (MAdV-2). Considering the genetic differences of the amplicon were 9%, 11% and 19% from MAdV-2 and at least 10% from each other, they seem to belong to up to three different novel types within the Murine mastadenovirus B species. This evidence of genetic diversity highlights the opportunities to isolate and study additional AdVs that infect rodents as models for AdV biology and pathology.

Treatment of polycystic liver disease. Update on the management.

Polycystic liver disease (PLD) may consist of autosomal dominant PLD or isolated PLD without renal impairment. The natural history of liver cysts is to increase in size and number, causing progressive disease that can lead to very large and incapacitating hepatomegaly. Only symptomatic hepatomegaly (pain, inability to eat, weight loss, dyspnea) or cystic complications such as infection or intracystic hemorrhage should be treated. The treatment of PLD thus covers a wide range of therapeutic options, ranging from non-intervention to liver transplantation, including needle aspiration evacuation with injection of sclerosant, laparoscopic fenestration and fenestration by laparotomy combined with liver resection. The choice between these different treatments depends on the symptomatology, the intrahepatic extension of the lesions and the patient's general condition. Hepatic resection is commonly chosen since the vast majority of PLD consists of multiple small cysts that are impossible or difficult to fenestrate. Since cysts are inhomogeneously distributed in the hepatic parenchyma with most areas less affected, the preservation of this less-involved territory allows liver regeneration relatively free of cysts. Hepatectomies for PLD are technically difficult because the planes and the vascular and biliary structures are compressed by the cysts. Liver transplantation, whether isolated or associated with renal transplantation, is indicated in cases of severe malnutrition and/or end-stage renal disease or if the volume of remnant parenchyma is insufficient and suggests failure of a partial hepatectomy.

[Metabolic complications of chronic kidney disease]. / Complications métaboliques de l'insuffisance rénale chronique.

Patients with Chronic Kidney Disease (CKD) are at risk of various metabolic complications, which can lead to health issues and even be life-threatening if not correctly treated, whereas they can be anticipated. Through clinical cases of patients taken from the daily practice, we propose to look into three of these common complications, namely hypocalcemia, hyperkalemia and metabolic acidosis. From the diagnostic approach to the patient care, these cases provide the opportunity to recall the fundamentals of these disorders and to present the recent literature date enlightening the knowledge related to them.

Molecular and Morphological Evidence for Interspecific Hybridization Between Cronartium ribicola and C. comandrae on Pinus flexilis in Southwestern Alberta.

In May 2003, a survey was conducted in southwestern Alberta, east of the Rocky Mountains, to determine the extent of the spread and genetic diversity of white pine blister rust, which is caused by Cronartium ribicola J.C. Fisch. Aeciospores were sampled from white pine blister rust cankers in three infected limber pine (Pinus flexilis James) stands separated from one another by 100 to 215 km. DNA genotypes were determined for 12 codominant PCR-SSCP (polymerase chain reaction-single strand conformation polymorphism) loci representing genes derived from an EST library. At each site sampled, some aecia displayed DNA genotypes that were heterozygous at all loci and possessed novel alleles (GenBank Accession Nos. DQ009533-DQ009611). At Waterton Lakes, Kananaskis County, and Porcupine Hills, 29%, 11%, and 3% of sampled aecia and 38%, 33%, and 10% of sampled trees, respectively, possessed these unusual profiles. In May 2004, similar genetic profiles were found at two of these sites, Waterton Lakes and Kananaskis County, at 17 and 25% of sampled aecia (25% of sampled trees). In each of these aecia, genotyping and sequence analysis revealed this pattern was due to the presence of one C. ribicola and one C. comandrae Peck. allele at each of the 12 loci. Scanning electron microscopy (SEM) revealed aeciospore morphology that was intermediate between C. ribicola and C. comandrae. Aeciospores were longer (16 to 20 × 25 to 40 µm) than the expected range for C. ribicola (18 to 20 × 22 to 31 µm) (3). They were also fusiform, obovoid or short-to-long ellipsoid, but not pyriform-acuminate as in C. comandrae, and without a true conspicuous smooth spot as in C. ribicola. This provides evidence for interspecific hybridization between C. ribicola and C. comandrae, the causal agent of comandra blister rust. We hypothesize that the presence of nearby C. comandrae-infected lodgepole pine (P. contorta Dougl.) could have led to spermatization of C. ribicola receptive hyphae by C. comandrae pycniospores, resulting in the formation of hybrid aecia. An important question is whether these hybrids have a different host range that could potentially extend its geographic range in areas where the telial host, Ribes spp. L., is not abundant. The hybrid rust Melampsora × columbiana Newcombe was shown to exhibit virulence against certain hybrid poplar clones that had previously been reported as resistant against both parental rusts (M. medusae Thuem. and M. occidentalis Jacks) and abundant pathogenic variation has been observed (2). Furthermore, the ability to colonize unexpected hosts could provide fitness advantages over parental species, as was observed in Phytophthora spp. pathogenic on alder (1). Host range and virulence assays should be conducted to assess the potential impact of this hybrid. References: (1) C. M. Brasier et al. Proc. Natl. Acad. Sci. USA 96:5878, 1999. (2) G. Newcombe et al. Phytopathology 91:981, 2001. (3) W. G. Ziller. The Tree Rusts of Western Canada. Can. For Serv. No. 1329. Pacific Forestry Center, Victoria, BC, 1974.

Sex-ratio meiotic drive in Drosophila simulans is related to equational nondisjunction of the Y chromosome.

The sex-ratio trait, an example of naturally occurring X-linked meiotic drive, has been reported in a dozen Drosophila species. Males carrying a sex-ratio X chromosome produce an excess of female offspring caused by a deficiency of Y-bearing sperm. In Drosophila simulans, such males produce approximately 70-90% female offspring, and 15-30% of the male offspring are sterile. Here, we investigate the cytological basis of the drive in this species. We show that the sex-ratio trait is associated with nondisjunction of Y chromatids in meiosis II. Fluorescence in situ hybridization (FISH) using sex-chromosome-specific probes provides direct evidence that the drive is caused by the failure of the resulting spermatids to develop into functional sperm. XYY progeny were not observed, indicating that few or no YY spermatids escape failure. The recovery of XO males among the progeny of sex-ratio males shows that some nullo-XY spermatids become functional sperm and likely explains the male sterility. A review of the cytological data in other species shows that aberrant behavior of the Y chromosome may be a common basis of sex-ratio meiotic drive in Drosophila and the signal that triggers differential spermiogenesis failure.

Ultrasonographic renal volume measurements in early autosomal dominant polycystic disease: comparison with CT-scan renal volume calculations.

PURPOSE: To investigate the correlation and concordance between the ellipsoid volume calculated by ultrasonography measurements (Vol3DUS) and the reference kidney volume measured by CT (VolTDM) in early autosomal dominant polycystic kidney disease (ADPKD). MATERIALS AND METHODS: Prospective study of the correlation and concordance of renal volumes in 24 patients with early ADPKD (48 kidneys analysed separately), with calculation of Vol3DUS using the formula for an ellipsoid in three different manners and VolTDM measurement by manual contouring. Calculations of correlation coefficients (r) and coefficients of intra-class correlation (ICC) with confidence intervals at 95%. RESULTS: The US volume was strongly correlated with the CT volume by using the maximum width in a transverse section (r=0.83) with a mean Vol3DUS=692±348ml [180; 2069]. The most reproducible ultrasonography measurement was the height. When the kidney volume exceeded 800ml, US underestimated the volume. However, the median error was -57.5ml [-1090; 183] and 85% of the Vol3DUS calculated differed by more than 5% from the reference measurement. CONCLUSION: The correlation between the US calculated volumes and the CT volumes was strong. However, the median error with ellipsoid US volume was too high to detect a small renal variation in early ADPKD.

Recent developments in the behavioral pharmacology of benzodiazepine (omega) receptors: evidence for the functional significance of receptor subtypes.

Recent research in molecular biology has demonstrated the complexity of GABAA receptors and shown that benzodiazepine (BZ-omega) receptor subtypes have a structural reality. It is therefore appropriate to ask whether the different pharmacological effects produced by benzodiazepines (anticonvulsant activity, anxiety reduction, motor incoordination, learning deficits, characteristic discriminative stimulus effects, tolerance and dependence) are associated with activity at different receptor subtypes. The present paper reviews the literature dealing with the behavioral effects of novel BZ (omega) receptor ligands relevant to the question of the functional significance of the BZ1 (omega 1) and BZ2 (omega 2) receptor subtypes. The only drugs currently available with a considerable degree of selectivity are alpidem and zolpidem. These compounds have relatively high affinity for GABAA receptors containing the alpha 1 subunit (corresponding to the BZ1 (omega 1) subtype) and very low affinity for receptors with the alpha 5 subunit (corresponding to one type of BZ2 (omega 2) receptor). Pharmacological effects observed with these, and other, less selective compounds allow several tentative conclusions to be drawn: (a) Little is known of the role of subtype selectivity in anxiolytic or amnestic effects but compounds with low intrinsic activity may reduce anxiety without giving rise to sedation or motor incoordination and BZ1 (omega 1) selective drugs appear to disrupt memory only at sedative doses; (b) Selectivity for BZ1 (omega 1) receptors may be associated with sleep-inducing activity but not with motor incoordination, suggesting that BZ2 (omega 2) receptors may be of particular importance in mechanisms of muscle relaxation; (c) The discriminative stimulus effects of different BZ (omega) receptor ligands are not identical and differences may be related to receptor selectivity; (d) Compounds with BZ1 (omega 1) selectivity and compounds with low intrinsic activity produce little or no tolerance and dependence. A wider range of selective compounds will be necessary to investigate these factors in detail and many different pharmacological profiles can be expected from drugs with selectivity and different levels of intrinsic activity.

PAX2 mutations in renal-coloboma syndrome: mutational hotspot and germline mosaicism.

The renal-coloboma syndrome (RCS, MIM 120330) is an autosomal dominant disorder caused by PAX2 gene mutations. We screened the entire coding sequence of the PAX2 gene for mutations in nine patients with RCS. We found five heterozygous PAX2 gene mutations: a dinucleotide insertion (2G) at position 619 in one sporadic RCS case, a single nucleotide insertion (619 + G) in three unrelated cases, and a single nucleotide deletion in a familial case. In this familial case, three affected sibs showed a striking ocular phenotypic variability. Each of the sibs carried a 619insG mutation, whilst unaffected parents did not, suggesting the presence of germline mosaicism. Interestingly, the 619insG mutation has been previously reported in several patients and is also responsible for the Pax21Neu mouse mutant, an animal model of human RCS. This study confirms the critical role of the PAX2 gene in human renal and ocular development. In addition, it emphasises the high variability of ocular defects associated with PAX2 mutations ranging from subtle optic disc anomalies to microphthalmia. Finally, the presence of PAX2 germline mosaicism highlights the difficulties associated with genetic counselling for PAX2 mutations.

Anxiolytic drugs and the acquisition of conditioned fear in mice.

Previous studies have shown that, in rodents, chlordiazepoxide and other benzodiazepines can interfere with learning in passive avoidance or conditioned suppression procedures. The most consistent effects are observed when the drugs are administered before the acquisition trial and subjects are re-tested in the non-drugged state. It is not clear, however, whether this effect on learning is associated with the behavioural depressant actions of these drugs. In the present study mice were injected with chloridiazepoxide, diazepam, zopiclone, or CGS 9896 and locomotor activity measured in a two-compartment box. The animals were then enclosed in one of the compartments and received a series of footshocks. On a second trial, 24 h after the first, the mice were returned to the box without injection and locomotion and time spent in each compartment were measured. During trial 1 chlordiazepoxide, diazepam, and zopiclone produced dose-related decreases in locomotor activity. The same doses disrupted fear conditioning. CGS 9896 also interfered with the conditioning of fear but did not reduce exploratory activity during the first trial at any of a wide range of doses, showing that learning can be affected without direct behavioural depressant activity. In a further experiment, chlordiazepoxide and CGS 9896 disrupted fear conditioning when injected before trial 1 but not when injected immediately after this trial. Mice drugged with chlordiazepoxide or CGS 9896 before both trials 1 and 2 also showed disrupted conditioning, demonstrating that the drug effects cannot be interpreted in terms of state dependent learning.