149 resultados para Reversal of sex
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Gender-dimorphic species often display a degree of sexual dimorphism in terms of life-history traits, yet little is known about dimorphism in androdioecious plants. Here we investigate sexual dimorphism in an androdioecious population of the wind-pollinated herb Mercurialis annua by comparing the resource allocation strategies of males and hermaphrodites grown under different nutrient-availability and competitive regimes. We found that males displayed smaller aboveground vegetative sizes than did hermaphrodites, but neither soil nutrient availability nor competition had a strong independent effect on their relative sizes. Plants adjusted their relative reproductive investment in response to nutrient availability. Specifically, hermaphrodites increased their reproductive allocation when growing in poor soils, whereas males displayed the opposite response. Finally, hermaphrodites were strongly female biased in their sex allocation, and this was more pronounced in nutrient-poor soils. To conclude, sexual dimorphism in androdioecious M. annua shares many features with dioecious and gynodioecious species, particularly wind-pollinated herbs. However, the direction of sex-allocation reaction norms displayed by hermaphrodites of M. annua differs from that documented for several insect-pollinated gynodioecious species, hinting at the importance of either the pollination mode or the sexual system as a context of selection shaping the reproductive strategy of plants with both male and female functions.
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OBJECTIVE: Prior to the implementation of the blood steroidal module of the Athlete Biological Passport, we measured the serum androgen levels among a large population of high-level female athletes as well as the prevalence of biochemical hyperandrogenism and some disorders of sex development (DSD). METHODS AND RESULTS: In 849 elite female athletes, serum T, dehydroepiandrosterone sulphate, androstenedione, SHBG, and gonadotrophins were measured by liquid chromatography-mass spectrometry high resolution or immunoassay. Free T was calculated. The sampling hour, age, and type of athletic event only had a small influence on T concentration, whereas ethnicity had not. Among the 85.5% that did not use oral contraceptives, 168 of 717 athletes were oligo- or amenorrhoic. The oral contraceptive users showed the lowest serum androgen and gonadotrophin and the highest SHBG concentrations. After having removed five doped athletes and five DSD women from our population, median T and free T values were close to those reported in sedentary young women. The 99th percentile for T concentration was calculated at 3.08 nmol/L, which is below the 10 nmol/L threshold used for competition eligibility of hyperandrogenic women with normal androgen sensitivity. Prevalence of hyperandrogenic 46 XY DSD in our athletic population is approximately 7 per 1000, which is 140 times higher than expected in the general population. CONCLUSION: This is the first study to establish normative serum androgens values in elite female athletes, while taking into account the possible influence of menstrual status, oral contraceptive use, type of athletic event, and ethnicity. These findings should help to develop the blood steroidal module of the Athlete Biological Passport and to refine more evidence-based fair policies and recommendations concerning hyperandrogenism in female athletes.
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BACKGROUND: Because of denervation supersensitivity, a miotic pupil in a sympathetically-denervated eye dilates in response to a dilute or weak alpha-1-agonist drug. A reversal of anisocoria after topical apraclonidine is considered as a positive test result that diagnoses a unilateral Horner syndrome. HISTORY AND SIGNS: Two women aged 34 and 46 years with a cocaine-confirmed oculosympathetic defect (Horner syndrome) were tested with 1 % topical apraclonidine on separate days. THERAPY AND OUTCOME: In one patient, her miotic Horner pupil dilated marginally but not enough to reverse the baseline anisocoria. Additionally, the upper lid on the same side retracted. There was no discernable effect of apraclonidine on the normal, contralateral eye. In the second patient, there was no pupillary response to apraclonidine but there was resolution of her ptosis. CONCLUSIONS: Neither patient demonstrated a reversal of anisocoria, the current criterion for diagnosing a Horner syndrome using apraclonidine. Thus, these two patients with an established oculosympathetic defect were said to have a "negative test" for Horner syndrome. Yet both women showed subtle pupil and/or lid changes in response to apraclonidine that were consistent with sympathetic denervation supersensitivity. Reversal of anisocoria following topical apraclonidine does not occur in all patients with a unilateral oculosympathetic defect and more specific parameters for defining a positive test result might optimize apraclonidine's utility as a diagnostic test for Horner syndrome
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Contexte : Hermaphrodisme, pseudohermaphrodisme, intersexe ou encore troubles du développement du sexe (Disorders of Sex Development) : autant de termes désignant des pathologies concernant une proportion non-négligeable de la population. Dans une société où le développement génital et l'identité sexuelle sont à la fois tabous et mal connus, le corps médical a un rôle clé à jouer dans la prise en charge à long terme ainsi que dans le soutien des patients intersexués et de leur entourage proche. Cette prise en charge commence par une information complète et transparente des parents et des enfants touchés. Objectifs : Elaborer un document capable de décrire de la manière la plus complète et compréhensible possible le thème de l'intersexualité. Il sera à la fois basé sur les connaissances médicales actuelles, mais également sur les témoignages de patients, parents et groupes de soutien aux intersexes. Il sera finalement destiné à l'information des parents ainsi que de leurs enfants intersexués à différentes étapes de leur développement. Méthode : Une compréhension approfondie de la thématique de l'intersexualité sur le plan médical, impliquant une approche multidisciplinaire, est une première étape cruciale. Agrémentée de témoignages de patients, de parents et des divers groupes de soutient actifs sur ce sujet, nous obtiendrons les bases nécessaires pour concevoir un document d'information à la fois le plus complet et le plus proche possible des attentes des patients et des parents. Résultat escompté : Répondre aux attentes formulées par les différents acteurs de la thématique de l'intersexualité et ainsi promouvoir une meilleure compréhension des mécanismes et des enjeux qui la caractérisent. Obtenir un feedback positif des groupes de soutien aux intersexes sur la qualité de l'information donnée dans ce document.
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Les parasites jouent un rôle clef dans l'évolution des comportements et des traits d'histoire de vie de leurs hôtes. Le parasitisme s'avère parfois dévastateur à l'échelle de population d'hôtes, et peut également altérer certains traits associés à la valeur sélective d'un individu infecté, tels que son succès reproducteur ou encore son taux de mortalité. La coévolution hôte/parasite, qui représente l'une des forces sélectives les plus puissantes dans l'évolution des organismes, peut également conduire les partenaires de l'association parasitaire à s'adapter localement à des environnements hétérogènes. Cette thèse porte sur l'étude de parasites aviaires, du genre Plasmodium, Haemopro- teus et Leucocytozoon (Haemosporidae), naturellement associés à différentes populations de mésanges charbonnières (Parus major) et d'hirondelles des fenêtres (Delichon ur- bicum). Dans un premier temps, nous avons cherché à déterminer comment se distribuent ces parasites au sein de différentes populations hôtes et si ces communautés de parasites sont structurées. Par la suite, la principale question à laquelle nous voulions répondre était de savoir comment ces parasites, et notamment après coexistence de plusieurs lignées génétiques d'Haemosporidae au sein dun même-individu (i.e. co-infection), affectent la physiologie et le succès de reproducteur des hôtes. Nos résultats suggèrent que la distribution des Haemosporidae est principalement gouvernée par la présence d'insectes vecteurs et que la persistance de l'infection chez les hôtes varie en fonction du genre d'Haemosporidae (Chapitre 1-2). Par ailleurs, nous avons trouvé que des lignées de parasite génétiquement distinctes peuvent avoir des effets contrastés sur leurs hôtes. Par exemple, les hôtes exhibent des différences de parasitémie marquées en fonction des lignées de parasites responsable de l'infection. De plus, le succès reproducteur ainsi que la charge parasitaire des mésanges infectées par Plasmodium ou Haemoproteus n'étaient pas affecté par l'infection simultanée avec Leucocytozoon (Chapitre 2-3). Dans le Chapitre 4, j'ai examiné la capacité immunitaire de mésanges charbonnières infectées par des hémosporidies. Les résultats n'ont pas été concluant, et je suggère fortement une réévaluation de ceux-ci dans de futures études. Les mésanges charbonnières ne semblent pas signaler leur statut infectieux par la coloration de leur plumage (Chapitre 5); toutefois, la coloration noire des plumes reflète l'état de stress oxydatif des mésanges, qui dépend lui-même de l'infection parasitaire. La coloration verte pourrait également indiquer la qualité des soins paxentaux délivrés par les mésanges adultes femelles à leurs petits, comme le suggère la corrélation que nous avons observée entre la masse des jeunes d'une nichée et la coloration de leur mère. Les hirondelles capturées en Algérie souffrent plus de l'infection que celles échantillon¬nées en Europe (Chapitre 6). Les similitudes observées entre les communautés de par¬asites affectant les populations européennes et celles des populations nord-africaines suggèrent que la transmission des parasites a lieu lors de la migration vers le sud. A l'instar de nos observations sur les mésanges dans les chapitres 2 et 3, les hirondelles co-infectées ne montrent pas d'altérations de leur condition physique. Cette thèse démontre qu'il existe, au sein des populations de mésanges charbonnières, des interactions antagonistes entre, d'une part, les parasites et leurs hôtes et d'autre part, entre différent parasites. Le résultat de ces interactions antagonistes varie en fonction des espèces et de la zone géographique considérée. Nous avons démontré que les interactions ne suivent pas toujours la théorie, puisque la coevolution qui, en suivant le concept de la virulence, devrait augmenter la charge parasitaire et diminuer la condition physique des hôtes, ne montre pourtant pas d'impact négatif sur les populations de mésanges. Nous pouvons maintenant concentrer nos efforts à la caractérisation des interactions antagonistes. De plus, grâce aux avancées des méthodes moléculaires, nous pouvons suivre et étudier en détails comment ces interactions se manifestent et quels sont leurs effets sur la condition physique des hôtes. - Parasites are key in shaping various behavioural and life-history traits of their hosts. The influence of parasitism on host populations varies from slight to devastating and might influence such parameters as mortality rates or reproductive success. Host-parasite coevolution is one of the most powerful selective forces in evolution and can lead to local adaptation of parasites and hosts in spatially structured environments. In this thesis, I studied haemosporidian parasites in different populations of great tits (Parus major) and house martins (Delichon urbicum). Firstly, I wanted to determine how parasites are distributed and if parasite communities are structured. The main question I wanted to address hereafter was how parasites, and specifically infection with multiple genera of parasites (i.e. co-infection) influenced host physiology and reproductive success. I found that parasite distribution is environmentally driven and could therefore be closely linked to vector prevalence; and that the stability of parasite infection over time is genus-dependent (Chapter 1 - 2). I further found that different haemosporidian lineages might interact differently with their hosts as parasitaemia was strongly lineage-specific and that the presence of Leucocytozoon parasites showed no correlation to Plasmodium or Haemoproteus parasitaemia, nor to great tit reproductive success (Chapter 2-3). In Chapter 4 I examined immune capacity of haemosporidian-infected great tits. The results proved inconclusive, and I strongly suggest re-evaluation hereof in future work. Great tits do not appear to signal parasite infection through plumage colouration (Chapter 5); however, infection did have a link to oxidative stress resistance which is strongly signalled through the black breast stripe, with darker males being more resistant and darker females less resistant. Females might incur different costs associated with darker stripes. This would allow reversal of signaling function. Green colouration could also serve as a cue for female provisioning quality as indicated by the strong correlation between colouration and chick body mass. Breeding house martins caught in Algeria suffer greater haemosporidian infection than European populations (Chapter 6). Similar parasite communities in European and North-African populations suggest transmission of parasites may occur during southward migration. Similarly to what was observed in great tits in Chapter 2 and 3, no relationship was found between parasite co-infection and Swiss house martin body condition. This thesis demonstrates that host-parasite and inter-parasite antagonistic interac¬tions exist in great tit populations. How these interactions play out is species dependent and varies geographically. I have demonstrated that interactions do not always follow the theory, as co-infection - which under the concept of virulence should increase parasitaemia and decrease body condition - showed no negative impact on great tit populations. We can now concentrate our efforts on characterising these antagonistic interactions, and with the advance in molecular methods, track and investigate how these interactions play out and what the effect on host fitness is.
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Many models of sex-biased dispersal predict that the direction of sex-bias depends upon a species' mating system. In agreement with this, almost all polygynous mammals show male-biased dispersal whereas largely monogamous birds show female-biased dispersal (FBD). The hamadryas baboon (Papio hamadryas hamadryas) is polygynous and so dispersal is predicted to be male biased, as is found in all other baboon subspecies, but there are conflicting field data showing both female and male dispersal. Using 19 autosomal genetic markers genotyped in baboons from four Saudi Arabian populations, we found strong evidence for FBD in post-dispersal adults but not, as expected, in pre-dispersal infants and young juveniles, when we compared male and female: population structure (F(st)), inbreeding (F(is)), relatedness (r), and the mean assignment index (mAIc). Furthermore, we found evidence for female-biased gene flow as population genetic structure (F(st)), was about four times higher for the paternally inherited Y, than for either autosomal markers or for maternally inherited mtDNA. These results contradict the direction of sex-bias predicted by the mating system and show that FBD has evolved recently from an ancestral state of male-biased dispersal. We suggest that the cost-benefit balance of dispersal to males and females is tightly linked to the unique hierarchical social structure of hamadryas baboons and that dispersal and social organization have coevolved.
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PURPOSE: To report the sudden onset of reversible Charles Bonnet syndrome precipitated byacute severe anemia. METHODS: The charts of three patients (Usher syndrome, bilateral macular degeneration, and bilateral retinal vein occlusion) with acute Charles Bonnet syndrome in the setting of severe anemia were reviewed. RESULTS: Anemia resulted from bladder surgery, recto-colitis, and severe urinary tract infection. Hemoglobin ranged from 78 to 86 g/L. Decreased visual acuity and formed visual hallucinations (giants, flowers, animals) were present in all three patients. Rapid reversal of Charles Bonnet syndrome and visual acuity improvement followed blood transfusion. CONCLUSIONS: Acute severe anemia can precipitate Charles Bonnet syndrome, which may be reversible by blood transfusion.
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Intraspecific variability in social organization is common, yet the underlying causes are rarely known. In the fire ant Solenopsis invicta, the existence of two divergent forms of social organization is under the control of a single Mendelian genomic element marked by two variants of an odorant-binding protein gene. Here we characterize the genomic region responsible for this important social polymorphism, and show that it is part of a pair of heteromorphic chromosomes that have many of the key properties of sex chromosomes. The two variants, hereafter referred to as the social B and social b (SB and Sb) chromosomes, are characterized by a large region of approximately 13 megabases (55% of the chromosome) in which recombination is completely suppressed between SB and Sb. Recombination seems to occur normally between the SB chromosomes but not between Sb chromosomes because Sb/Sb individuals are non-viable. Genomic comparisons revealed limited differentiation between SB and Sb, and the vast majority of the 616 genes identified in the non-recombining region are present in the two variants. The lack of recombination over more than half of the two heteromorphic social chromosomes can be explained by at least one large inversion of around 9 megabases, and this absence of recombination has led to the accumulation of deleterious mutations, including repetitive elements in the non-recombining region of Sb compared with the homologous region of SB. Importantly, most of the genes with demonstrated expression differences between individuals of the two social forms reside in the non-recombining region. These findings highlight how genomic rearrangements can maintain divergent adaptive social phenotypes involving many genes acting together by locally limiting recombination.
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Most plant species are hermaphrodites, with both male and female functions performed by the same individuals. However, separate sexes (dioecy) have evolved on numerous independent occasions, probably either in response to selection for inbreeding avoidance, or because it pays individuals to specialize in one gender or the other. Although the evolution of dioecy from hermaphroditism tends to be thought of as a one-way path, dioecy has broken down to yield hermaphroditic populations on several occasions. One such case is found in the mainly dioecious genus Mercurialis (Euphorbiaceae). In the species complex M. annua, diploids are dioecious, but polyploid populations are variously monoecious or androdioecious (where males co-exist with functional hermaphrodites). This species complex offers rich material for addressing questions concerning the evolution and ecology of combined versus separate sexes, the evolution of secondary sexual dimorphism, which likely contributes to the stability of dioecy in the genus, and the evolution and genetics of sex determination and sex chromosomes. The species also offers itself as a valuable teaching tool for addressing topics ranging from sex-ratio selection to inter-sexual competition.
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Pioneer work on iontophoresis undertaken by David Maurice during the 1970s and 1980s laid the initial groundwork for its potential implementation as a promising ocular therapeutic modality. A better understanding of tissue interactions within the eye during electric current application, along with better designs of drug delivery devices have enabled us to pursue David Maurice's original ideas and take them from the bench to the bed side. In the present study we demonstrate the potential application of an iontophoresis device (Eyegate, Optis, France) for the treatment of certain human eye diseases. Seventeen patients received a penetrating keratoplasty (PKP) at various intervals before presentation with active graft rejection in our clinic and were treated using this iontophoresis device. Methylprednisolone sodium succinate (MP) 62.5 mg/ml was infused within the Eyegate ocular probe container and an electrical current of 1.5 mA was delivered for 4 min with the negative pole connected to the ocular probe. Patients were treated on an ambulatory basis and received a standard course of three iontophoresis applications given once a day over 3 consecutive days. After treatment, 15 of the 17 treated eyes (88%) demonstrated a complete reversal of the rejection processes. In two eyes, only a partial and temporary improvement was observed. The mean best corrected visual acuity of all 17 patients during the last follow up visit was 0.37 +/- 0.2 compared to 0.06 +/- 0.05 before initiation of the iontophoresis treatment. The mean follow-up time was 13.7 months with a range of 5-29 months for the 17 patients. No significant side-effects associated with the iontophoresis treatment were observed. Thus, for the management of active corneal graft rejection, iontophoresis of MP can be an alternative to very frequent instillations of eye drops, or to pulsed intravenous therapy of corticosteroids.
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The genus Silene, studied by Darwin, Mendel and other early scientists, is re-emerging as a system for studying interrelated questions in ecology, evolution and developmental biology. These questions include sex chromosome evolution, epigenetic control of sex expression, genomic conflict and speciation. Its well-studied interactions with the pathogen Microbotryum has made Silene a model for the evolution and dynamics of disease in natural systems, and its interactions with herbivores have increased our understanding of multi-trophic ecological processes and the evolution of invasiveness. Molecular tools are now providing new approaches to many of these classical yet unresolved problems, and new progress is being made through combining phylogenetic, genomic and molecular evolutionary studies with ecological and phenotypic data.
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BackgroundFacioscapulohumeral muscular dystrophy type 1(FSHD1) is an autosomal dominant disorder associated with the contraction of D4Z4 less than 11 repeat units (RUs) on chromosome 4q35. Penetrance in the range of the largest alleles is poorly known. Our objective was to study the penetrance of FSHD1 in patients carrying alleles ranging between 6 to10 RUs and to evaluate the influence of sex, age, and several environmental factors on clinical expression of the disease. Methods A cross-sectional multicenter study was conducted in six French and one Swiss neuromuscular centers. 65 FSHD1 affected patients carrying a 4qA allele of 6¿10 RUs were identified as index cases (IC) and their 119 at-risk relatives were included. The age of onset was recorded for IC only. Medical history, neurological examination and manual muscle testing were performed for each subject. Genetic testing determined the allele size (number of RUs) and the 4qA/4qB allelic variant. The clinical status of relatives was established blindly to their genetic testing results. The main outcome was the penetrance defined as the ratio between the number of clinically affected carriers and the total number of carriers. Results Among the relatives, 59 carried the D4Z4 contraction. At the clinical level, 34 relatives carriers were clinically affected and 25 unaffected. Therefore, the calculated penetrance was 57% in the range of 6¿10 RUs. Penetrance was estimated at 62% in the range of 6¿8 RUs, and at 47% in the range of 9¿10 RUs. Moreover, penetrance was lower in women than men. There was no effect of drugs, anesthesia, surgery or traumatisms on the penetrance. Conclusions Penetrance of FSHD1 is low for largest alleles in the range of 9¿10 RUs, and lower in women than men. This is of crucial importance for genetic counseling and clinical management of patients and families.
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UNLABELLED: Pharmacologically-induced activation of replication competent proviruses from latency in the presence of antiretroviral treatment (ART) has been proposed as a step towards curing HIV-1 infection. However, until now, approaches to reverse HIV-1 latency in humans have yielded mixed results. Here, we report a proof-of-concept phase Ib/IIa trial where 6 aviremic HIV-1 infected adults received intravenous 5 mg/m2 romidepsin (Celgene) once weekly for 3 weeks while maintaining ART. Lymphocyte histone H3 acetylation, a cellular measure of the pharmacodynamic response to romidepsin, increased rapidly (maximum fold range: 3.7-7.7 relative to baseline) within the first hours following each romidepsin administration. Concurrently, HIV-1 transcription quantified as copies of cell-associated un-spliced HIV-1 RNA increased significantly from baseline during treatment (range of fold-increase: 2.4-5.0; p = 0.03). Plasma HIV-1 RNA increased from <20 copies/mL at baseline to readily quantifiable levels at multiple post-infusion time-points in 5 of 6 patients (range 46-103 copies/mL following the second infusion, p = 0.04). Importantly, romidepsin did not decrease the number of HIV-specific T cells or inhibit T cell cytokine production. Adverse events (all grade 1-2) were consistent with the known side effects of romidepsin. In conclusion, romidepsin safely induced HIV-1 transcription resulting in plasma HIV-1 RNA that was readily detected with standard commercial assays demonstrating that significant reversal of HIV-1 latency in vivo is possible without blunting T cell-mediated immune responses. These finding have major implications for future trials aiming to eradicate the HIV-1 reservoir. TRIAL REGISTRATION: clinicaltrials.gov NTC02092116.
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BACKGROUND: Reference intervals for many laboratory parameters determined in 24-h urine collections are either not publicly available or based on small numbers, not sex specific or not from a representative sample. METHODS: Osmolality and concentrations or enzymatic activities of sodium, potassium, chloride, glucose, creatinine, citrate, cortisol, pancreatic α-amylase, total protein, albumin, transferrin, immunoglobulin G, α1-microglobulin, α2-macroglobulin, as well as porphyrins and their precursors (δ-aminolevulinic acid and porphobilinogen) were determined in 241 24-h urine samples of a population-based cohort of asymptomatic adults (121 men and 120 women). For 16 of these 24 parameters creatinine-normalized ratios were calculated based on 24-h urine creatinine. The reference intervals for these parameters were calculated according to the CLSI C28-A3 statistical guidelines. RESULTS: By contrast to most published reference intervals, which do not stratify for sex, reference intervals of 12 of 24 laboratory parameters in 24-h urine collections and of eight of 16 parameters as creatinine-normalized ratios differed significantly between men and women. For six parameters calculated as 24-h urine excretion and four parameters calculated as creatinine-normalized ratios no reference intervals had been published before. For some parameters we found significant and relevant deviations from previously reported reference intervals, most notably for 24-h urine cortisol in women. Ten 24-h urine parameters showed weak or moderate sex-specific correlations with age. CONCLUSIONS: By applying up-to-date analytical methods and clinical chemistry analyzers to 24-h urine collections from a large population-based cohort we provide as yet the most comprehensive set of sex-specific reference intervals calculated according to CLSI guidelines for parameters determined in 24-h urine collections.