915 resultados para colour defects
Resumo:
OBJECTIVE: In 2005-2006, several studies noted an increased risk of cardiovascular birth defects associated with maternal use of paroxetine compared with other antidepressants in the same class. In this study, the authors sought to determine whether paroxetine was associated with an increased risk of cardiovascular defects in infants of women exposed to the drug during the first trimester of pregnancy. METHOD: From teratology information services around the world, the authors collected prospectively ascertained, unpublished cases of infants exposed to paroxetine early in the first trimester of pregnancy and compared them with an unexposed cohort. The authors also contacted the authors of published database studies on antidepressants as a class to determine how many of the women in those studies had been exposed to paroxetine and the rates of cardiovascular defects in their infants. RESULTS: The authors were able to ascertain the outcomes of 1,174 infants from eight services. The rates of cardiac defects in the paroxetine group and in the unexposed group were both 0.7%. The rate in the database studies (2,061 cases from four studies) was 1.5%. CONCLUSIONS: Paroxetine does not appear to be associated with an increased risk of cardiovascular defects following use in early pregnancy, as the incidence in more than 3,000 infants was well within the population incidence of approximately 1%.
Resumo:
BACKGROUND: This study determines the prevalence of Congenital Heart Defects (CHD), diagnosed prenatally or in infancy, and fetal and perinatal mortality associated with CHD in Europe. METHODS AND RESULTS: Data were extracted from the European Surveillance of Congenital Anomalies central database for 29 population-based congenital anomaly registries in 16 European countries covering 3.3 million births during the period 2000 to 2005. CHD cases (n=26 598) comprised live births, fetal deaths from 20 weeks gestation, and terminations of pregnancy for fetal anomaly (TOPFA). The average total prevalence of CHD was 8.0 per 1000 births, and live birth prevalence was 7.2 per 1000 births, varying between countries. The total prevalence of nonchromosomal CHD was 7.0 per 1000 births, of which 3.6% were perinatal deaths, 20% prenatally diagnosed, and 5.6% TOPFA. Severe nonchromosomal CHD (ie, excluding ventricular septal defects, atrial septal defects, and pulmonary valve stenosis) occurred in 2.0 per 1000 births, of which 8.1% were perinatal deaths, 40% were prenatally diagnosed, and 14% were TOPFA (TOPFA range between countries 0% to 32%). Live-born CHD associated with Down syndrome occurred in 0.5 per 1000 births, with > 4-fold variation between countries. CONCLUSION: Annually in the European Union, we estimate 36 000 children are live born with CHD and 3000 who are diagnosed with CHD die as a TOFPA, late fetal death, or early neonatal death. Investing in primary prevention and pathogenetic research is essential to reduce this burden, as well as continuing to improve cardiac services from in utero to adulthood.
Resumo:
The cuticle is a physical barrier that prevents water loss and protects against irradiation, xenobiotics and pathogens. This classic textbook statement has recently been revisited and several observations were made showing that this dogma falls short of being universally true. Both transgenic Arabidopsis thaliana lines expressing cell wall-targeted fungal cutinase (so-called CUTE plants) or lipase as well as several A. thaliana mutants with altered cuticular structure remained free of symptoms after an inoculation with Botrytis cinerea. The alterations in cuticular structure lead to the release of fungitoxic substances and changes in gene expression that form a multifactorial defence response. Several models to explain this syndrome are discussed.
Resumo:
Many characteristics, for example life-history traits, physiological tolerance to heat and cold, and energy requirements, contribute to a population's ability to persist in the face of climatic variation. Recent studies have suggested that the presence of intraspecific colour polymorphism could be another potential contributor to population resilience (e.g. to climate change) in ectothermic vertebrates such as reptiles. In the present study, we tested for a relationship between the presence of intraspecific colour polymorphism and the age of snake species. Using phylogenetic comparative methods, we demonstrate that the presence of intraspecific colour polymorphism is correlated with the age of a species, with polymorphic snake species being significantly older than monomorphic species. Understanding how species have dealt with past environmental modifications, such as climate change, can provide important insights into how they are likely to respond in the future to ongoing climate warming.
Resumo:
Ornamental colours usually evolve as honest signals of quality, which is supported by the fact that they frequently depend on individual condition. It has generally been suggested that some, but not all types of ornamental colours are condition dependent, indicating that different evolutionary mechanisms underlie the evolution of multiple types of ornamental colours even when these are exhibited by the same species. Stress hormones, which negatively affect condition, have been shown to affect colour traits based on different pigments and structures, suggesting that they mediate condition dependence of multiple ornament types both among and within individuals. However, studies investigating effects of stress hormones on different ornament types within individuals are lacking, and thus, evidence for this hypothesis is scant. Here, we investigated whether corticosterone mediates condition dependence of multiple ornaments by manipulating corticosterone levels and body condition (via food availability) using a two-factorial design and by assessing their effect on multiple colour traits in male common lizards. Corticosterone negatively affected ventral melanin- and carotenoid-based coloration, whereas food availability did not affect coloration, despite its significant effect on body condition. The corticosterone effect on melanin- and carotenoid-based coloration demonstrates the condition dependence of both ornaments. Moreover, corticosterone affected ventral coloration and had no effect on the nonsexually selected dorsal coloration, showing specific effects of corticosterone on ornamental ventral colours. This suggests that corticosterone simultaneously mediates condition dependence of multiple colour traits and that it therefore accounts for covariation among them, which may influence their evolution via correlational selection.
Resumo:
In hyperdiploid acute lymphoblastic leukaemia (ALL), the simultaneous occurrence of specific aneuploidies confers a more favourable outcome than hyperdiploidy alone. Interphase (I) FISH complements conventional cytogenetics (CC) through its sensitivity and ability to detect chromosome aberrations in non-dividing cells. To overcome the limits of manual I-FISH, we developed an automated four-colour I-FISH approach and assessed its ability to detect concurrent aneuploidies in ALL. I-FISH was performed using centromeric probes for chromosomes 4, 6, 10 and 17. Parameters established for automatic nucleus selection and signal detection were evaluated (3 controls). Cut-off values were determined (10 controls, 1000 nuclei/case). Combinations of aneuploidies were considered relevant when each aneuploidy was individually significant. Results obtained in 10 ALL patients (1500 nuclei/patient) were compared with those by CC. Various combinations of aneuploidies were identified. All clones detected by CC were observed by I-FISH. I-FISH revealed numerous additional abnormal clones, ranging between 0.1% and 31.6%, based on the large number of nuclei evaluated. Four-colour automated I-FISH permits the identification of concurrent aneuploidies of prognostic significance in hyperdiploid ALL. Large numbers of cells can be analysed rapidly by this method. Owing to its high sensitivity, the method provides a powerful tool for the detection of small abnormal clones at diagnosis and during follow up. Compared to CC, it generates a more detailed cytogenetic picture, the biological and clinical significance of which merits further evaluation. Once optimised for a given set of probes, the system can be easily adapted for other probe combinations.
Resumo:
Ideally, reconstruction of lower extremity soft tissue defects includes not only an esthetically pleasing 3-dimensional shape and solid anchoring to the underlying structures to resist shear forces, but should also address the restoration of sensation. Therefore, we present a prospective study on defect reconstruction of the lower leg and ankle to evaluate the role of sensate free fasciocutaneous lateral arm flap and the impact of sensory nerve reconstruction. Thirty patients were allocated randomly to the study group (n = 15) that obtained end-to-side sensate coaptation using the lower lateral cutaneous brachial nerve to the tibial nerve using the epineural window technique, or to the control group reconstructed without nerve coaptation. At 1-year follow-up the patients were evaluated for pain sensation, thermal sensibility, static and moving 2-point discrimination, and Semmes-Weinstein monofilament tests. Data from both groups were compared and statistically analyzed with the Mann-Whitney U test and the Fisher exact test. Flaps of the study group reached a static and moving 2-point discrimination and Semmes-Weinstein monofilament tests nearly equal to the contralateral leg area and significantly better than flaps of the control group. Donor damage morbidity of the tibial nerve did not occur. To our point of view resensation should be carried out by end-to-side neurorrhaphy to the tibial nerve because of the superior restoration of sensibility.
Resumo:
An unusual subset of mature T cells expresses natural killer (NK) cell-related surface markers such as interleukin-2 receptor beta (IL-2R beta; CD122) and the polymorphic antigen NK1.1. These "NK-like" T cells are distinguished by their highly skewed V alpha and V beta repertoire and by their ability to rapidly produce large amounts of IL-4 upon T cell receptor (TCR) engagement. The inbred mouse strain SJL (which expresses NK1.1 on its NK cells) has recently been reported to lack NK1.1+ T cells and consequently to be deficient in IL-4 production upon TCR stimulation. We show here, however, that SJL mice have normal numbers of IL-2R beta+ T cells with a skewed V beta repertoire characteristic of "NK-like" T cells. Furthermore lack of NK1.1 expression on IL-2R beta+ T cells in SJL mice was found by backcross analysis to be controlled by a single recessive gene closely linked to the NKR-P1 complex on chromosome 6 (which encodes the NK1.1 antigen). Analysis of a panel of inbred mouse strains further demonstrated that lack of NK1.1 expression on IL-2R beta+ T cells segregated with NKR-P1 genotype (as assessed by restriction fragment length polymorphism) and thus was not restricted to the SJL strain. In contrast, defective TCR induced IL-4 production (which appeared to be a unique property of SJL mice) seems to be controlled by two recessive genes unlinked to NKR-P1. Collectively, our data indicate that "NK-like" T cells develop normally in SJL mice despite genetically distinct defects in NK1.1 expression and inducible IL-4 production.
Resumo:
SummarySimultaneous detection of aneuploidies for chromosomes 4, 6,10 and 17 by automated four color l-FISH in high hyperdiploid acute lymphoblastic leukemia: diagnostic assessment, clonal heterogeneity and chromosomal instability in adultsAnna Talamo BlandinService de Génétique Médicale, Unité de Cytogénétique du Cancer, CHUVAcute lymphoblastic leukemia (ALL) is a malignant hemopathy characterized by the accumulation of the immature lymphoid cells in the bone marrow and, most often, in the peripheral blood. ALL is a heterogeneous disease with distinct biological and prognostic entities. At diagnosis, cytogenetic and molecular findings constitute important and independent prognostic factors. High hyperdiploidy with 51-67 chromosomes (HeH), one of the largest cytogenetic subsets of ALL, in childhood particularly, is generally associated with a relatively favorable outcome. Chromosome gain is nonrandom, extracopies of some chromosome occurring more frequently than those of others. Concurrent presence of trisomy for chromosomes 4, 10 and 17 confers an especially good prognosis. The first aim of our work was to develop an automated four color interphase fluorescence in situ hybridization (l-FISH) methodology and to assess its ability to detect concurrent aneuploidies 4, 6, 10 and 17 in 10 ALL patients. Various combinations of aneuploidies were identified. All clones detected by conventional cytogenetics were also observed by l-FISH. However, in all patients, l-FISH revealed numerous additional abnormal clones, leading to a high level of clonal heterogeneity. Our second aim has been to investigate the nature and origin of this clonal heterogeneity and to test for the presence of chromosome instability (CIN) in HeH ALL at initial presentation. Ten HeH ALL and 10 non-HeH ALL patients were analysed by four colour l-FISH and numerical CIN values were determined for all four chromosomes together and for each chromosome and patient group, an original approach in ALL. CIN values in HeH ALL proved to be much higher than#iose in non-HeH ALL, suggesting that numerical CIN may be at the origin of the high level of clonal heterogeneity revealed by l-FISH. Our third aim has been to study the evolution of these cytogenetic features during the course of the disease in 10 HeH ALL patients. Clonal heterogeneity was also observed again during disease progression, particularly at relapse. Clones detected at initial presentation generally reappeared in relapse, in most cases with newly generated ones. A significant correlation between the number of abnormal clones and CIN suggested that the higher the instability, the larger the number of abnormal clones. Whereas clonal heterogeneity and its evolution most probably result from underlying chromosome instability, operating processes remain conjectural.RésuméLa leucémie lymphoblastique aiguë (LLA) est une hémopathie maligne qui résulte de l'accumulationde cellules lymphoïdes immatures dans la moelle osseuse, et, le plus souvent, dans le sangpériphérique également. La LLA est une affection hétérogène au sein de laquelle se distinguentplusieurs entités biologiques et pronostiques. Les données cytogénétiques et moléculaires font partieintégrante du diagnostic et jouent un rôle essentiel dans l'évaluation du pronostic. L'hyperdiploïdieélevée à 51-67 chromosomes (HeH), relativement fréquente, en particulier chez l'enfant, s'associe àun pronostic favorable. Le gain de chromosomes ne relève pas du hasard, certains chromosomesétant plus fréquemment impliqués que d'autres. La présence simultanée des trisomies 4, 6, et 17s'associe à un pronostic particulièrement bon. Le premier but du travail a été de développer uneméthode d'analyse automatique par hybridation in situ fluorescente interphasique (I-FISH) à 4couleurs et de tester sa capacité à identifier la présence simultanée d'aneuploïdies 4, 6, 10 et 17 dans10 cas de LLA. Différentes combinaisons d'aneuploïdies ont été identifiées. Tous les clones détectéspar cytogénétique conventionnelle l'ont été par I-FISH. Or, chez tous les patients, l'I-FISH a révélé denombreux clones anormaux additionnels générant un degré élevé d'hétérogénéité clonale. Notredeuxième but a été d'investiguer la nature et l'origine de cette hétérogénéité et de tester la présenced'instabilité chromosomique (CIN) chez les patients avec une LLA HeH en presentation initiale. DixLLA HeH et 10 LLA non-HeH ont été analysées par I-FISH et les valeurs de CIN numérique ont étédéterminées pour les 4 chromosomes ensemble et pour chaque chromosome et groupe de patients,approche originale dans la LLA. Ces valeurs étant beaucoup plus élevées dans la LLA HeH que dansla LLA non-HeH, elles favorisent l'hypothèse selon laquelle la CIN serait à l'origine de l'hétérogénéitéclonale révélée par I-FISH. Le troisième but de notre travail a été d'étudier l'évolution de cescaractéristiques cytogénétiques au cours de la maladie dans 10 cas de LLA HeH. L'hétérogénéitéclonale a été retrouvée lors de la progression de la maladie, en particulier en rechute, où les clonesanormaux détectés en présentation initiale réapparaissent, généralement accompagnés de clonesnouveaux. La corrélation existant entre nombre de clones anormaux et valeurs de CIN suggère queplus l'instabilité est élevée, plus le nombre de clones anormaux est grand. Bien que l'hétérogénéitéclonale et son évolution résultent très probablement de l'instabilité chromosomique, les processus àl'oeuvre ne sont pas entièrement élucidés.
Resumo:
Several hypotheses might explain the evolution and maintenance of colour morphs within animal populations. The 'alternative foraging strategy' hypothesis states that alternative colour morphs exploit different ecological niches. This hypothesis predicts that morphs differ in diet, either because foraging success on alternative prey species is morph-dependent or because differently coloured individuals exploit alternative habitats. I examined this prediction in the Barn Owl Tyto alba, a bird that varies in plumage coloration continuously from dark reddish-brown to white. On the European continent, Owls are light-coloured (subspecies T. a. alba) in the south and reddish-brown (T. a. guttata) in the north; in central Europe the two subspecies interbreed, generating many colour variants. If plumage coloration indicates alternative foraging strategies, in sympatry dark- and light-coloured owls should consume prey species that are typical of the diets of T. a. guttata and T. a. alba in allopatry, respectively. In line with this prediction, both in allopatry and in sympatry in Switzerland T. a. guttata fed primarily upon Common Voles Microtus arvalis and T. a. alba upon Wood Mice Apodemus spp. Statistical analyses suggest that morph-dependent diet did not arise from a non-random habitat distribution of owls with respect to plumage coloration. This suggests that foraging success upon alternative prey is morph-dependent.
Resumo:
Résumé : Les mécanismes de contrôle des couleurs mélaniques chez les vertébrés sont encore discutés parmi les biologistes de l'évolution. Une hypothèse récente affirme que les effets pléiotropies du système des mélanocortines expliquent l'association fréquente entre la coloration eumélanique noire (due à la déposition d'eumélanine) et de nombreux traits physiologiques et comportementaux. De nombreuses études suggèrent, en effet, que des niveaux plus élevés des mélanocortines induisent l'assombrissement des téguments eumélaniques et affectent d'autres traits phénotypiques simultanément. Cependant, il n'est pas encore établi si ce mécanisme de pléiotropie peut s'appliquer aux colorations dues à la déposition de phaeomélanine, une autre forme commune de mélanine. Les antagonistes des mélanocortines déclenchent le phaeomélanogenèse et bloquent l'effet des mélanocortines ou ont un effet pharmacologique opposé. Nous nous proposons donc d'évaluer l'hypothèse que les effets pléiotropes des antagonistes des mélanocortines génèrent des covariations entre la coloration phaeomélanique et des aspects de la qualité individuelle. Comme prédit par cette hypothèse, nous constatons chez la chouette effraie (Tyto alba) que les traits phénotypiques (résistance au stress oxydatif et aux parasites) corrèlent positivement au degré d'expression d'une couleur eumélanique mais négativement au degré d'expression d'une coloration phaeomélanique. Puis, nous montrons chez la chouette hulotte (Strix aluco) que les associations génétiques entre la coloration phaeomélanique et la physiologie (immunité et la régulation de l'homéostasie) confèrent des avantages aux individus de différentes couleurs dans différents environnements caractérisés par l'abondance de nourriture et le niveau d'exposition aux parasites. Ainsi, nos études soutiennent l'hypothèse que les effets pléiotropes des antagonistes des mélanocortines génèrent des covariations entre les traits mélaniques et divers aspects de la qualité individuelle. Finalement, nous montrons chez le faucon crécerelle (Falco Tinnunculus) que l'expression des ornements mélaniques est sensible à la qualité de l'environnement dans lequel les individus grandissent. Ceci suggère que les gènes codant pour les mélanocortines et leurs antagonistes pourraient induire une expression des traits mélaniques dépendante de la condition de l'individu, un pattern d'expression rarement observé pour des traits généralement sous fort contrôle génétique. Summary : The information content and control mechanisms of melanin-based colour signals in vertebrates are still debated among evolutionary biologists. A recent hypothesis contends that pleiotropic effects of the melanocortin system accounts for the frequent association between black eumelanic coloration and physiological and behavioural traits. Accordingly, empirical evidence suggests that higher levels of melanocortins concurrently promote darker eumelanic integuments and affect other phenotypic traits. However, whether this mechanism may apply to signals relying on phaeomelanin, another common form of melanin pigments, remains to be established. Melanocortin antagonists trigger phaeomelanogenesis and block the effect of melanocortins or result in the opposite pharmacological effect. Therefore, we tested the hypothesis that pleiotropic effects of melanocortin antagonists and inverse agonists account for covariations between phaeomelanin-based coloration and aspects of individual quality. As predicted, we found that phenotypic traits (resistance to oxidative stress and parasites) correlated positively with a eumelanic trait and negatively with a phaeomelanic trait in the barn owl (Tyto alba). Then, we showed in the tawny owl (Strix aluco) that genetic associations between phaeomelanin-based coloration and physiology (immunity and regulation of energy homeostasis) confer benefits to differently coloured individuals under different levels of food abundance and parasite exposure. Altogether, our studies support the hypothesis that pleiotropic effects of melanocortins antagonists can indeed account for covariations between phaeomelanin-based traits and aspects of individual quality. Eventually, we show in the Eurasian kestrel (Falco Tinnunculus) that expression of melanin-based ornaments is sensitive to the environment in which individuals grow. This suggests that genes coding for melanocortins and their antagonists can mediate the condition-dependent component of melanin-based traits.
Resumo:
Primary rib involvement accounts for 16% of paediatric Ewing sarcoma (ES). Neo-adjuvant chemotherapy and surgical tumor resection may leave large thoracic wall defects requiring complex reconstruction in a growing individual. We report our experience in three children aged 3, 10, and 12 years, in whom single-stage resection and reconstruction were performed using a Gore-Tex Dualmesh patch, covered by a latissimus dorsi rotation flap harvested in continuity with the thoracolumbar fascia. The youngest patient also had a vertical expandable prosthetic titanium rib (VEPTR) anchored to help prevent subsequent scoliosis throughout growth.
Resumo:
In the present study 387 dung beetles (Coleoptera: Scarabaeidae) were surveyed at the Serra do Japi, in the Atlantic Forest in São Paulo State, with four baited pitfall traps during the months of December, 1998, and January, 1999 during eight 24 hour cycles. A total of 30 species were identified and temporal variation in activity patterns among the species shows a specialization in the use of food resources: 9 species were classified as nocturnal and 13 as diurnal. The daily activity pattern of dung beetles does not necessarily correspond to the taxonomic classification, but is strongly related to the colouring of species, determined by predominant elytra colour: nocturnal species have 89 % more chances of being black as opposed to colourful. Black nocturnal species might have evolved as an interspecific adaptation to avoid predation (cryptic colouring). Among the colourful diurnal dung beetles, measure of body length of each species shows that development of bright colouring was more often found in medium to large species, which suggests that colouring evolved as a response to intraspecific pressures, important in agonistic encounters among males.
Resumo:
Beetles of the species Chauliognathus fallax Germar 1824 are polymorphic for elytron colouration with six morphs distinguished on the basis of black pigmentation on a yellow background. We investigated samples of C. fallax taken in eight consecutive weeks aiming to determine the frequency of the morphs which were grouped, for statistical analysis, into three classes according to elytra pigmentation as well as the possible occurrence of assortative mating. Our results showed a variation in the frequency of the classes throughout the season, both in males and females, with the maximum frequency of each class at the fourth and fifth week. The three classes (A, B, C) showed the same pattern of variation, and class B was always the more frequent. To test randomness of matings two approaches were taken: in the first, we compared the frequency of each class in copulating and non-copulating insects. In the second, the frequency of each class in the whole sample was taken as the probability of occurrence of the respective class; then, using the criterion of the probability of independent events we calculated the expected proportion of copulating insects for each pair of events. Both methods gave non-significant differences, suggesting that the matings were random.