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1.
Rev Med Liege ; 74(5-6): 253-257, 2019 05.
Article in French | MEDLINE | ID: mdl-31206262

ABSTRACT

Alcohol consumption by physicians is an important issue for health systems due to its possible impacts on health workforce and quality of care. The aim of this narrative review of the literature was to analyze the prevalence, risk factors, detection and care of hazardous alcohol consumption by physicians and medical students. The prevalence of risky alcohol use among physicians is higher than the overall population. Factors associated to higher risk are being a male, age, burnout components and personality characteristics like neuroticism, extroversion and alexithymia. Detection and care of physicians with risky alcohol use is complex. There is no organized screening for risky drinking. Furthermore, physicians tend to specifically neglect their health and do not easily consult their colleagues. It appears appropriate to set up a prevention strategy for physicians and medical students, as well as to develop support structures.


La consommation problématique d'alcool chez les médecins est un enjeu important pour les systèmes de santé en raison des répercussions possibles sur les forces de travail et sur la qualité des soins donnés aux patients. L'objectif de cette revue narrative de la littérature est d'étudier la prévalence, les facteurs de risque, la détection et la prise en charge des consommations problématiques d'alcool chez les médecins et les étudiants en médecine. Le pourcentage de médecins ayant une consommation d'alcool à risque est supérieur à celui de la population générale. Les facteurs identifiés comme corrélés à un plus haut risque de consommation problématique d'alcool sont le genre masculin, l'âge, des composantes du burnout et des traits de personnalité comme le névrosisme, l'extraversion et l'alexithymie. La détection et la prise en charge des médecins avec une consommation problématique d'alcool semblent complexes en raison de l'absence d'organisme veillant au dépistage des consommations à risque et à certaines caractéristiques des médecins les incitant à négliger leur santé et à ne pas consulter un confrère. Il semble donc opportun de mettre en place des stratégies de prévention, visant les médecins et les étudiants en médecine, mais également de développer des structures de soutien aux médecins en difficultés.


Subject(s)
Alcohol Drinking , Physicians , Students, Medical , Humans , Male , Prevalence , Surveys and Questionnaires
3.
Arch Pediatr ; 24(6): 527-533, 2017 Jun.
Article in French | MEDLINE | ID: mdl-28416428

ABSTRACT

INTRODUCTION: When oral rehydration is not feasible, enteral rehydration via the nasogastric route has been the ESPGHAN recommended method of rehydration since 2008, rather than intravenous rehydration (IVR), for children with acute gastroenteritis. However, these recommendations are rarely followed in France. Since 2011, in case of failure of oral rehydration, enteral rehydration has been used as a first-line therapy in the Children's Emergency Department at the Grenoble-Alpes University Hospital. PURPOSE: The aims of the study were to compare the length of the hospital stay, the duration of initial rehydration, and the incidence of complications and failure with the use of enteral nasogastric versus intravenous rehydration. METHODS: This study compared two cohorts of children (<3 years of age) with mild-to-moderate dehydration caused by acute gastroenteritis and failure of rehydration via the oral route. The first group (winter 2010-2011) was managed according to the previous protocol (intravenous rehydration). The second group (winter 2011-2012) was managed according the new protocol (nasogastric tube rehydration [NGR]). The rest of the gastroenteritis management was identical in both groups. RESULTS: A total of 132 children were included, 65 were treated with nasogastric tube rehydration (NGR) and 67 with intravenous rehydration. There was a significant reduction in the duration of hospitalization in the post-emergency unit in the NGR group: 23.6h vs 40.1h (P<0.05). The duration of initial rehydration was also significantly reduced (10.5h vs 22.0h). There was no significant difference regarding serious adverse events. However, the NGR group presented more mild adverse events (22 vs 7, P<0.05) and more treatment failures (15.3% vs 3%, P=0.013). CONCLUSION: Nasogastric rehydration reduces the duration of rehydration and the length of the hospital stay without increasing the incidence of serious adverse events for dehydrated children hospitalized for acute gastroenteritis.


Subject(s)
Dehydration/therapy , Fluid Therapy/methods , Gastroenteritis/complications , Intubation, Gastrointestinal , Child, Preschool , Cohort Studies , Dehydration/etiology , Emergency Service, Hospital , Female , France , Humans , Infant , Infusions, Intravenous , Male , Retrospective Studies , Time Factors , Vomiting/etiology
5.
Arch Pediatr ; 22(9): 967-70, 2015 Sep.
Article in French | MEDLINE | ID: mdl-26239287

ABSTRACT

Injection site reactions (ISRs) are quite common side effects defined by a local adverse drug reaction directly caused by a vaccine. Twenty-four hours after an intramuscular injection (in the deltoid muscle) of the diphtheria, tetanus, acellular pertussis, inactivated poliomyelitis, Haemophilus influenza type b (DTPCa-Hib) combined vaccine, a 3-year-old boy developed fever. A few hours later, local redness and swelling appeared at the injection site, with rapid extension to the entire limb, it was pain-free, and no other clinical anomalies were present. The patient received intravenous antibiotics for suspected cellulitis. The progression was favorable in 12h (apyrexia and decreased limb swelling), allowing the intravenous antibiotic treatment to be discontinued. Since the child was in excellent general health and recovery was fast, an ISR was diagnosed. Extensive limb swelling is frequent, mostly after the fourth dose of DTPCa-Hib. Deltoid muscle injection of DTP vaccine increases the risk of ISR compared to injection in the thigh, before the age of 3 years. The introduction of acellular pertussis vaccine decreased the risk of general side effects but may increase the risk of ISR. These reactions disappear with symptomatic treatment and do not contraindicate the product.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Cellulitis/drug therapy , Cellulitis/etiology , Diphtheria-Tetanus-acellular Pertussis Vaccines/adverse effects , Haemophilus Vaccines/adverse effects , Poliovirus Vaccine, Inactivated/adverse effects , Child, Preschool , Deltoid Muscle/pathology , Humans , Male , Treatment Outcome , Vaccines, Combined/adverse effects
6.
Eur J Pediatr ; 174(12): 1665-70, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26174105

ABSTRACT

Soft infant carriers such as slings have become extremely popular in the west and are usually considered safe. We report 19 cases of sudden unexpected death in infancy (SUDI) linked to infant carrier. Most patients were healthy full-term babies less than 3 months of age, and suffocation was the most frequent cause of death. CONCLUSION: Infant carriers represent an underestimated cause of death by suffocation in neonates. WHAT IS KNOWN: • Sudden unexpected deaths in infancy linked to infant carrier have been only sparsely reported. WHAT IS NEW: • We report a series of 19 cases strongly suggesting age of less than 3 months as a risk factor and suffocation as the mechanism of death.


Subject(s)
Asphyxia/etiology , Cause of Death , Infant Equipment/adverse effects , Sudden Infant Death/etiology , Female , Humans , Infant , Infant, Newborn , Male , Risk Factors
7.
Arch Pediatr ; 22(6): 574-9, 2015 Jun.
Article in French | MEDLINE | ID: mdl-25911057

ABSTRACT

INTRODUCTION: The northern French Alps emergency network (RENAU) manages emergent care and patient treatment pathways in a three-county area in the French Alps. The aim of the study was to describe the pediatric activity in mobile intensive care units (MICUs). METHOD: This retrospective observational study was conducted from 1 January to 31 December 2012. Data were obtained from patients' medical records in seven representative MICUs of the RENAU. Consecutive patients between 1 month and 18 years of age were enrolled. RESULTS: During the study period, MICUs carried out 11,951 primary transports and 3087 secondary transfers. A total of 1325 patients were enrolled: 1087 primary transports and 238 secondary transfers. In primary interventions, 531 (48.9%) patients were managed for a trauma, 118 (11%) children were discharged and stayed home, 427 (39.9%) underwent an intravenous cannulation and 27 (2.5%) on-scene intubation. A pediatrician was in charge of 64 (26.9%) secondary transfers. Among 1649 (18%) mountain rescues, 296 (18.7%) involved a child. CONCLUSION: Emergency physicians in MICUs are involved with children's prehospital care and need dedicated materiel and special training.


Subject(s)
Ambulances , Emergency Treatment , Intensive Care Units , Adolescent , Child , Child, Preschool , Female , France , Humans , Infant , Male , Retrospective Studies
8.
Acta Clin Belg ; 69(5): 341-7, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25056492

ABSTRACT

INTRODUCTION: In many countries, out-of-hours medical care is under scrutiny. The aim of this article is to study the activities recorded by the first out-of-hours clinic that has been opened, as a pilot study, in two Walloon communes. MATERIAL AND METHOD: A retrospective analysis of anonymized data was conducted for 2009. Coding of diagnoses was conducted using the International Classification of Primary Care (ICPC-2). RESULTS: A total of 3949 contacts were recorded in 2009 with the out-of-hours clinic, 3294 related to inhabitants of the two communes covered, which was equivalent to 13% of the total population in question. Compared to 7·2% of contacts between midnight and 8 a.m., 82·9% of contacts took place between 8 a.m. and 9 p.m., and 91·6% of contacts were handled locally, with only 8·4% resulting in hospitalization. In addition, 52% of contacts were with patients aged between 25 and 65; 29·9% of contacts were with paediatric patients (<15 years). Patients over the age of 65 made up 18% of contacts. The most common pathologies were respiratory (R). Analysis of flu diagnoses identified two epidemic peaks. DISCUSSION: The suburban out-of-hours clinic studied fulfilled an important role in managing the demand for health care. The large majority of health problems were resolved locally, and the inhabitants did not need to go to hospital. Appointments between midnight and 8 a.m. were in the minority, which points towards adjusting the organization of the out-of-hours service during the night. The geriatric population is not highly over-represented contrary to what might be expected considering its largest number of pathologies. The on-call doctor's skills profile should take account of the populations and morbidities encountered. Out-of-hours clinics could possibly play a sentinel role in terms of flu epidemics. CONCLUSION: This study describes a pilot suburban out-of-hours clinic which met three of recommendations set by the KCE in its report on out-of-hours care in general medicine: the organization of an out-of-hours clinic with logistical support, the use of a single telephone number and merging out-of-hours areas. While debate exists on the management of out-of-hours care, this study provides evidence on the role of the physician during these hours.


Subject(s)
After-Hours Care/statistics & numerical data , Ambulatory Care Facilities/statistics & numerical data , Suburban Health Services/statistics & numerical data , Adolescent , Adult , Aged , Belgium/epidemiology , Child , Child, Preschool , Humans , Infant , Infant, Newborn , Middle Aged , Pilot Projects , Retrospective Studies , Young Adult
9.
Arch Pediatr ; 18(11): 1196-200, 2011 Nov.
Article in French | MEDLINE | ID: mdl-21963071

ABSTRACT

In France, the number of deaths remains high in the pediatric population. These deaths are rarely subject to a scientific or forensic autopsy. However, this medical act appears necessary to answer the many private and public questions (public health, prevention, judicial, or even institutional) that can arise. Two pediatric clinical observations raising these questions in the context of a household accident are presented. In the first one, the death led to the establishment of a forensic obstacle to the burial and a forensic autopsy. The autopsy results provided answers, both to the relatives and to the court. The second concerns a deceased child managed within the protocol for sudden infant death syndrome. The autopsy was not authorized by the parents and no answer on the causes of death could be determined. These 2 observations underline the importance and utility of this medical act.


Subject(s)
Autopsy , Cause of Death , Child, Preschool , Female , Humans , Infant, Newborn , Male
10.
Arch Pediatr ; 18(5): 505-11, 2011 May.
Article in French | MEDLINE | ID: mdl-21458977

ABSTRACT

STUDY OBJECTIVE: The clinical manifestations and outcome of infants and children with confirmed 2009 H1N1 influenza in emergency departments is described. METHODS: We conducted a prospective multicenter case series involving children with symptoms of influenza-like illness in whom 2009 H1N1 influenza was diagnosed on reverse-transcriptase polymerase chain reaction assay on a nasopharyngeal swab or nasal aspirates and who were admitted to the ED of four university pediatric hospitals. The following data were collected: age, gender, preexisting chronic conditions (PECs) associated with a high risk for influenza-related complications, clinical symptoms, outcome, antiviral treatment, and complications. We recorded length of cough and fever during a phone-call on day 8. RESULTS: Between 1st October and 31st December 2009, 466 children were included. Their median age was 4 years (range, 1 day to 17 years). The median time to consultation was 24h. Of these 466 infants and children, 55 were aged less than three months and 153 had one or more PECs. Asthma was the most frequent condition. Children at risk and children without risk did not differ for complications (28% vs 31%, P>0.05). Respiratory complications (17%) and decompensations of preexisting disease were the most frequent. Infants aged less than three months did not have more complications than infants without PECs. At-risk infants and children were more frequently hospitalized (P<0.02) and the duration of the pediatric ward stay was longer (P<0.02). This was true only for children aged less than three months. Of the hospitalized children, 17 (9%) were admitted to an ICU. Duration of fever (3.8 days) and duration of cough (6.3 days) did not differ according to whether or not children received oseltamivir. CONCLUSION: Infants younger than three months of age are not a group at risk for influenza-related complications. Oseltamivir did not reduce duration of symptoms in this population.


Subject(s)
Influenza A Virus, H1N1 Subtype , Influenza, Human/diagnosis , Adolescent , Antiviral Agents/therapeutic use , Child , Child, Preschool , Emergency Service, Hospital , Female , Hospitalization , Humans , Infant , Infant, Newborn , Influenza, Human/drug therapy , Male , Oseltamivir/therapeutic use , Prospective Studies , Treatment Outcome
11.
J Evol Biol ; 24(5): 1071-9, 2011 May.
Article in English | MEDLINE | ID: mdl-21332860

ABSTRACT

Three different isolated populations of the slave-making ant Rossomyrmex minuchae, sympatric with its obligate host Proformica longiseta, are known from the high mountains of southern Spain. To test the prediction that the slave-maker and its host represent a coevolutionary geographical mosaic, we studied the variation in the cuticular hydrocarbons (CHCs) as the trait most likely to show the selection mosaic, plus trait remixing by the gene flow in the populations of each species by means of microsatellites. We found within populations, host and parasite had more similar CHC profiles than between the populations or between parasites and allopatric hosts. The differences between the CHC profiles of the host and parasite, which may be responsible for the level of tolerance towards the parasite, varied between the populations suggesting the existence of a selection mosaic of coevolution. Furthermore, P. longiseta showed higher gene flow than R. minuchae, which would allow local variation in the coevolution of the host and parasite while allowing some trait remixing.


Subject(s)
Ants/genetics , Behavior, Animal , Biological Evolution , Gene Flow , Phylogeography , Animals , Ants/chemistry , Female , Hydrocarbons/chemistry , Male , Microsatellite Repeats , Selection, Genetic , Spain
13.
J Anim Sci ; 88(4): 1321-31, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20042549

ABSTRACT

In mammals, posttesticular epididymal sperm maturation is considered an essential step in the transformation of immature testicular gametes to mature spermatozoa capable of fertilization. Reactive oxygen species (ROS) have been shown to be key actors in this maturation process, and it is now clear that ROS are central for sperm physiology in processes such as sperm maturation and capacitation. However, during epididymal maturation and storage and until the onset of fertilization, oxidative damage is a threat spermatozoa must face more than any other cells. Spermatozoa were found to be extremely sensitive to oxidative attacks correlated with lipid peroxidation, DNA damage, and impaired sperm motility, all affecting fertilization. To control the quantity of H(2)O(2) in the vicinity of male gametes, mammalian epididymis uses a panel of nonenzymatic and enzymatic scavengers, among which the glutathione peroxidase (GPx) family is largely represented. Among the various GPx proteins expressed in the mammalian epididymis, GPx4 and GPx5 occupy unique positions and functions that are reviewed in this paper. This paper underlines the importance of the GPx protein family in determining the fertilizing potential of mammalian spermatozoa. This is particularly relevant in the field of mammalian fertility and infertility as well as in the development of assisted medical procreation technologies and male gamete preservation techniques that are extensively used in human and animal reproduction programs.


Subject(s)
Glutathione Peroxidase/physiology , Spermatozoa/physiology , Animals , Epididymis/physiology , Fertility/physiology , Glutathione Peroxidase/metabolism , Humans , Male , Mitochondria/metabolism , Mitochondria/physiology , Oxidation-Reduction , Reactive Oxygen Species/metabolism , Sperm Maturation/physiology , Spermatozoa/metabolism
14.
Arch Pediatr ; 14 Suppl 3: S176-80, 2007 Oct.
Article in French | MEDLINE | ID: mdl-17961812

ABSTRACT

Acute gastroenteritis remains a common and often severe illness among infants and children throughout the world. The management of a child with acute diarrhea includes rehydration and maintenance fluids with oral rehydration solutions (ORS), combined with continued age-appropriate nutrition. However, although substantial data support the role of continued nutrition in improving gastrointestinal function and anthropometric, biochemical, and clinical outcomes, the practice of continued feeding during diarrheal episodes has been difficult to establish as accepted standard of care. Recommendations for maintenance dietary therapy depend on the age and diet history of the patient. It has been clear for many years that, when affected by gastroenteritis, breastfed infants should be continued on breast milk without any need for interruption and, by that way, will get faster recovery and improved nutrition. Moreover, many well-conducted studies have provided evidence that in formula-fed children not severely dehydrated, a rapid return to full feeding is well tolerated. Lactose intolerance and/or secondary cow's milk allergy are not a clinical concern for the vast majority of patients. In fact early refeeding i.e resumption of normal diet, in amounts sufficient to satisfy energy and nutrient requirements, should be the rule. However, in children younger than 6 months of age, the lack of suitable studies must lead to caution and use of specific lactose-free or extensively hydrolysate formulae, especially in case of severe and/or prolonged diarrhea. Several studies support the use of zinc supplementation or probiotics for acute diarrhea but some doubts persist in infant in developed countries.


Subject(s)
Diarrhea, Infantile/diet therapy , Diarrhea/diet therapy , Child , Child Nutritional Physiological Phenomena , Child, Preschool , Fluid Therapy , Humans , Infant , Infant Food , Infant Nutritional Physiological Phenomena , Rehydration Solutions/therapeutic use
15.
Mol Ecol ; 16(2): 345-54, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17217349

ABSTRACT

Cardiocondyla elegans is a Mediterranean ant that nests on river banks. It rears only wingless (ergatoid) males that live peacefully in the same nest as opposed to other species of the same genus, which have both peaceful, winged and mutually aggressive 'ergatoid' males. Using microsatellite analysis, we investigated the genetic structure of 21 colonies from three different locations as well as the parentage of sexuals of two colonies of C. elegans. We show that C. elegans is strictly monogynous, and that its nests can contain foreign sexuals. The presence of alien sexuals inside ant nests is described for the first time and probably counteracts inbreeding resulting from matings between siblings. In the laboratory, aggression tests showed that workers only allow alien males to enter their nests, while all winged female sexuals attempting to enter were attacked. Nevertheless, the presence of alien female sexuals in nests in the field seems to result from active carrying behaviour by workers during the reproductive period.


Subject(s)
Ants/genetics , Genetics, Population , Nesting Behavior/physiology , Sexual Behavior, Animal/physiology , Animals , Ants/physiology , Female , France , Male , Microsatellite Repeats/genetics , Observation , Polymerase Chain Reaction , Reproduction/physiology , Spermatozoa/chemistry
16.
Cytogenet Genome Res ; 110(1-4): 441-7, 2005.
Article in English | MEDLINE | ID: mdl-16093696

ABSTRACT

Brassica oleracea and Arabidopsis thaliana belong to the Brassicaceae(Cruciferae) family and diverged 16 to 19 million years ago. Although the genome size of B. oleracea (approximately 600 million base pairs) is more than four times that of A. thaliana (approximately 130 million base pairs), their gene content is believed to be very similar with more than 85% sequence identity in the coding region. Therefore, this important difference in genome size is likely to reflect a different rate of non-coding DNA accumulation. Transposable elements (TEs) constitute a major fraction of non-coding DNA in plant species. A different rate in TE accumulation between two closely related species can result in significant genome size variations in a short evolutionary period. Short interspersed elements (SINEs) are non-autonomous retroposons that have invaded the genome of most eukaryote species. Several SINE families are present in B. oleracea and A. thaliana and we found that two of them (called RathE1 and RathE2) are present in both species. In this study, the tempo of evolution of RathE1 and RathE2 SINE families in both species was compared. We observed that most B. oleracea RathE2 SINEs are "young" (close to the consensus sequence) and abundant while elements from this family are more degenerated and much less abundant in A. thaliana. However, the situation is different for the RathE1 SINE family for which the youngest elements are found in A. thaliana. Surprisingly, no SINE was found to occupy the same (orthologous) genomic locus in both species suggesting that either these SINE families were not amplified at a significant rate in the common ancestor of the two species or that older elements were lost and only the recent (lineage-specific) insertions remain. To test this latter hypothesis, loci containing a recently inserted SINE in the A. thaliana col-0 ecotype were selected and characterized in several other A. thaliana ecotypes. In addition to the expected SINE containing allele and the pre-integrative allele (i.e. the "empty" allele), we observed in the different ecotypes, alleles with truncated portions of the SINE (up to the complete loss of the element) and of the immediate genomic flanking sequences. The absence of SINEs in orthologous positions between B. oleracea and A. thaliana and the presence in recently diverged A. thaliana ecotypes of alleles containing severely truncated SINEs suggest a very high rate of SINE loss in these species.


Subject(s)
Arabidopsis/genetics , Brassica/genetics , Short Interspersed Nucleotide Elements/genetics , Arabidopsis/classification , Brassica/classification , Chromosome Deletion , Chromosomes, Plant , DNA, Plant/genetics , DNA, Plant/isolation & purification , Evolution, Molecular , Phylogeny , Polymerase Chain Reaction
17.
Mol Phylogenet Evol ; 31(3): 880-93, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15120386

ABSTRACT

In order to reconstruct ants' phylogeny, we analysed DNA sequences for two nuclear genes, abdominal-A and Ultrabithorax, from 49 species of ants and two outgroups. As these genes control the development of the first segments of the abdomen in insects, which are very variable in ants (petiole, postpetiole, and gaster constriction), we hypothesized that the morphological variations between the subfamilies may be correlated with mutations of some abd-A or Ubx regions. Contrarily to our hypothesis, these sequences are highly conserved. The differences observed concern mainly third codon positions and present some saturation. Phylogenetic reconstructions were carried out using the genetic raw sequence data and by combining them with a set of morphological data (Total Evidence). Relations among subfamilies of ants remains poorly resolved with molecular data only, but adding these data to morphological characters confirms and reinforce the topology of : a Poneroid complex [Ponerinae, Cerapachyinae, Leptanillinae and army ants], a Formicoid complex [Dolichoderinae, Formicinae] and a Myrmecoid complex [Myrmicinae, Myrmeciinae, Pseudomyrmecinae, Nothomyrmeciinae]. Our molecular results allow resolution near the branch tips and three subfamilies (Dolichoderinae, Formicinae and Pseudomyrmecinae) always appear as monophyletic. The Formicinae and the Dolichoderinae have close relationships. The Camponotini appear as a strong clade inside the Formicinae. The Ponerinae are separated in two parts: the Ectatommini and all other tribes. The Cerapachyinae, Dorylinae, and Ecitoninae belong to the same clade, the Cerapachyinae being confirmed in their subfamily status. The Myrmicinae appears to be very heterogeneous, with the Attini forming a very stable and well-separated group.


Subject(s)
Ants/genetics , Drosophila Proteins/genetics , Homeodomain Proteins/genetics , Nuclear Proteins/genetics , Phylogeny , Transcription Factors/genetics , Animals , Base Sequence , Drosophila melanogaster , Molecular Sequence Data , Sequence Analysis, DNA , Species Specificity
18.
Proc Biol Sci ; 269(1503): 1911-8, 2002 Sep 22.
Article in English | MEDLINE | ID: mdl-12350253

ABSTRACT

Social parasites are able to exploit their host's communication code and achieve social integration. For colony foundation, a newly mated slave-making ant queen must usurp a host colony. The parasite's brood is cared for by the hosts and newly eclosed slave-making workers integrate to form a mixed ant colony. To elucidate the social integration strategy of the slave-making workers, Polyergus rufescens, behavioural and chemical analyses were carried out. Cocoons of P. rufescens were introduced into subcolonies of four potential host species: Formica subgenus Serviformica (Formica cunicularia and F. rufibarbis, usual host species; F. gagates, rare host; F. selysi, non-natural host). Slave-making broods were cared for and newly emerged workers showed several social interactions with adult Formica. We recorded the occurrence of abdominal trophallaxis, in which P. rufescens, the parasite, was the donor. Social integration of P. rufescens workers into host colonies appears to rely on the ability of the parasite to modify its cuticular hydrocarbon profile to match that of the rearing species. To study the specific P. rufescens chemical profile, newly emerged callows were reared in isolation from the mother colony (without any contact with adult ants). The isolated P. rufescens workers exhibited a chemical profile closely matching that of the primary host species, indicating the occurrence of local host adaptation in the slave-maker population. However, the high flexibility in the ontogeny of the parasite's chemical signature could allow for host switching.


Subject(s)
Ants/drug effects , Ants/parasitology , Pheromones/pharmacology , Animals , Ants/chemistry , Ants/classification , Behavior, Animal/drug effects , Biological Evolution , Host-Parasite Interactions/drug effects , Hydrocarbons/analysis , Social Behavior , Species Specificity
19.
Mol Biol Evol ; 18(12): 2315-22, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11719581

ABSTRACT

We have characterized the two families of SINE retroposons present in Arabidopsis thaliana. The origin, distribution, organization, and evolutionary history of RAthE1 and RAthE2 elements were studied and compared to the well-characterized SINE S1 element from Brassica. Our studies show that RAthE1, RAthE2, and S1 retroposons were generated independently from three different tRNAs. The RAthE1 and RAthE2 families are older than the S1 family and are present in all tested Cruciferae species. The evolutionary history of the RAthE1 family is unusual for SINEs. The 144 RAthE1 elements of the Arabidopsis genome cannot be classified in distinct subfamilies of different evolutionary ages as is the case for S1, RAthE2, and mammalian SINEs. Instead, most RAthE1 elements were probably derived steadily from a single source gene that was maintained intact and active for at least 12-20 Myr, a result suggesting that the RAthE1 source gene was under selection. The distribution of RAthE1 and RAthE2 elements on the Arabidopsis physical map was studied. We observed that, in contrast to other Arabidopsis transposable elements, SINEs are not concentrated in the heterochromatic regions. Instead, SINEs are grouped in the euchromatic chromosome territories several hundred kilobase pairs long. In these territories, SINE elements are closely associated with genes. A retroposition partnership between Arabidopsis SINEs and LINEs is proposed.


Subject(s)
Arabidopsis/genetics , Evolution, Molecular , RNA, Transfer/genetics , Short Interspersed Nucleotide Elements/genetics , Brassica/genetics , Chromosome Mapping , Genes, Plant , Molecular Sequence Data , Phylogeny , RNA, Transfer/classification
20.
Behav Processes ; 55(2): 67-73, 2001 Aug 15.
Article in English | MEDLINE | ID: mdl-11470498

ABSTRACT

This study investigates the role of social stimulation on nestmate recognition in mature workers of Camponotus fellah. We isolated 4-week-old workers before examining their behaviour in dyadic reunion tests. At the age of 4 weeks, workers are normally intolerant towards both allospecific and homospecific but allocolonial individuals. However, when they were isolated for up to 20 days, allocolonial aggressions decreased while allospecific aggression remained constant. Workers isolated for 20 days also engaged in allocolonial trophallaxis. These results suggest that workers need to be reinforced by social stimulation during their adult life to keep precise nestmate recognition capacities. We discuss our data under the perspective of recent neuroethological data in social insects to propose a mechanism for the formation of the neural template used in the nestmate recognition process.

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