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Foliar nutrient resorption (NuR) plays a key role in ecosystem functioning and plant nutrient economy. Most of this recycling occurs during the senescence of leaves and is actively addressed by cells. Here, we discuss the importance of cell biochemistry, physiology, and subcellular anatomy to condition the outcome of NuR at the cellular level and to explain the existence of limits to NuR. Nutrients are transferred from the leaf in simple metabolites that can be loaded into the phloem. Proteolysis is the main mechanism for mobilization of N, whereas P mobilization requires the involvement of different catabolic pathways, making the dynamics of P in leaves more variable than those of N before, during, and after foliar senescence. The biochemistry and fate of organelles during senescence impose constraints that limit NuR. The efficiency of NuR decreases, especially in evergreen species, as soil fertility increases, which is attributed to the relative costs of nutrient acquisition from soil decreasing with increasing soil nutrient availability, while the energetic costs of NuR from senescing leaves remain constant. NuR is genetically determined, with substantial interspecific variability, and is environmentally regulated in space and time, with nutrient availability being a key driver of intraspecific variability in NuR.
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Ecossistema , Nitrogênio , Nitrogênio/metabolismo , Fósforo/metabolismo , Plantas/metabolismo , SoloRESUMO
PREMISE: Because of expected range shifts associated with climate change, there is a renewed interest in the evolutionary factors constraining adaptation, among which are genetic bottlenecks, drift, and increased mutational load after range expansion. Here we study adaptation in the short-lived species Leontodon longirostris showing reduced genetic diversity and increased genetic load along an expansion route. METHODS: We assessed the phenological patterns of variation, and their effect on fitness-related traits, on 42 L. longirostris populations and six populations of the sister taxa L. saxatilis in a common garden located within the current range of both species. The comparison among L. longirostris populations allowed us to test for genetic clines consistent with local adaptation, whereas the comparison between taxa provided evidence for common adaptive features at the species level. RESULTS: We found significant within-species variability for most traits, as well as differences with its close relative L. saxatilis. In general, seeds from drier, warmer, and unpredictable habitats showed overall lower and more restricted conditions for germination, seedlings emerged later and plants flowered earlier. Consequently, genotypes from arid and unpredictable environments attained smaller reproductive sizes and allocated more biomass to reproduction. Flowering time had the strongest direct effect on total plant size, but seedling emergence also showed an important indirect effect. CONCLUSIONS: Our results show the crucial role of phenological patterns in shaping adaptive clines for major life-history stage transitions. Furthermore, the genetic load observed in L. longirostris does not seem to preclude adaptation to the climatic variability encountered along the expansion route.
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Adaptação Fisiológica , Asteraceae , Aclimatação , Germinação , Fenótipo , PlantasRESUMO
Unravelling the evolutionary processes underlying range expansions is fundamental to understand the distribution of organisms, as well as to predict their future responses to environmental change. Predictions for range expansions include a loss of genetic diversity and an accumulation of deleterious alleles along the expansion axis, which can decrease fitness at the range-front (expansion load). In plants, empirical studies supporting expansion load are scarce, and its effects remain to be tested outside a few model species. Leontodon longirostris is a colonizing Asteraceae with a widespread distribution in the Western Mediterranean, providing a particularly interesting system to gain insight into the factors that can enhance or mitigate expansion load. In this study, we produced a first genome draft for the species, covering 418 Mbp (~53% of the genome). Although incomplete, this draft was suitable to design a targeted sequencing of ~1.5 Mbp in 238 L. longirostris plants from 21 populations distributed along putative colonization routes in the Iberian Peninsula. Inferred demographic history supports a range expansion from southern Iberia around 40,000 years ago, reaching northern Iberia around 25,000 years ago. The expansion was accompanied by a loss of genetic diversity and a significant increase in the proportion of putatively deleterious mutations. However, levels of expansion load in L. longirostris were smaller than those found in other plant species, which can be explained, at least partially, by its high dispersal ability, the self-incompatible mating system, and the fact that the expansion occurred along a strong environmental cline.
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Asteraceae , Variação Genética , Evolução Biológica , Demografia , Europa (Continente)RESUMO
Detecting the molecular basis of local adaptation and identifying selective drivers is still challenging in nonmodel species. The use of purely population genetic approaches is limited by some characteristics of genetic systems, such as pleiotropy and polygenic control, and parallel evidence from phenotypic-based experimental comparisons is required. In long-lived organisms, the detection of selective pressures might also be precluded by evolutionary lag times in response to the environment. Here, we used the English yew to showcase an example of a multiscale integrative approach in a nonmodel species with limited plant and genomic resources. We combined information from two independent sources, phenotypes in a common environment and genomic data in natural populations, to investigate the signature of selection. Growth differences among populations in a common environment, and phenological patterns of both shoot elongation and male strobili maturation, were associated with climate clines, providing evidence for local adaptation and guiding us in the selection of populations for genomic analyses. We used information on over 25,000 SNPs from c. 1,200 genes to infer the demographic history and to test for molecular signatures of selection at different levels: SNP, gene, and biological pathway. Our results confirmed an overall demographic history of population decline, but we also found evidence for putative local adaptation at the molecular level. We identified or confirmed several candidate genes for positive and negative selection in forest trees, including the pseudo-response regulator 7 (PRR7), an essential component of the circadian clock in plants. In addition, we successfully tested an approach to detect polygenic adaptation in biological pathways, allowing us to identify the flavonoid biosynthesis pathway as a candidate stress-response pathway that deserves further attention in other plants. Finally, our study contributes to the emerging view that explaining contemporary standing genetic variation requires considering adaptation to past climates, especially for long-lived trees.
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KEY MESSAGE: We provide novel genomic resources for Taxus baccata in the form of a reference transcriptome, SSR and SNP markers, and orthologous single-copy genes, useful for phylogenomic and population genomic applications. English yew (T. baccata) is the only European representative of the Taxaceae family, a conifer group originated in the Jurassic period. The wide extent of environmental heterogeneity within the species' range, together with its long presence in Europe, make English yew an ideal species to investigate adaptive evolution in conifers. To enlarge the genomic resources available for this species, we used Illumina short read sequencing followed by de novo assembly to build the transcriptome of English yew. In addition to a fully annotated transcriptome as well as large sets of new potential SSR and SNP markers for T. baccata, we provide a data set of orthologous single-copy genes across three Taxus species using Picea sitchensis as outgroup, and discuss ortholog uses and limitations for phylogenomic and population genomic applications.
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Taxus/genética , Transcriptoma , DNA Complementar/química , DNA Complementar/genética , Genômica , Sequenciamento de Nucleotídeos em Larga Escala , Repetições de Microssatélites/genética , Anotação de Sequência Molecular , Filogenia , Picea/genética , Polimorfismo de Nucleotídeo Único/genética , Análise de Sequência de DNARESUMO
Despite the large body of research devoted to understanding the role of Quaternary glacial cycles in the genetic divergence of European trees, the differential contribution of geographic isolation and/or environmental adaptation in creating population genetic divergence remains unexplored. In this study, we used a long-lived tree (Taxus baccata) as a model species to investigate the impact of Quaternary climatic changes on genetic diversity via neutral (isolation-by-distance) and selective (isolation-by-adaptation) processes. We applied approximate Bayesian computation to genetic data to infer its demographic history, and combined this information with past and present climatic data to assess the role of environment and geography in the observed patterns of genetic structure. We found evidence that yew colonized Europe from the East, and that European samples diverged into two groups (Western, Eastern) at the beginning of the Quaternary glaciations, c. 2.2 Myr before present. Apart from the expected effects of geographical isolation during glacials, we discovered a significant role of environmental adaptation during interglacials at the origin of genetic divergence between both groups. This process may be common in other organisms, providing new research lines to explore the effect of Quaternary climatic factors on present-day patterns of genetic diversity.
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Adaptação Biológica , Mudança Climática , Taxus/genética , Clima , DNA de Cloroplastos , Europa (Continente) , Variação Genética , Camada de Gelo , Repetições de Microssatélites , FilogeografiaRESUMO
INTRODUCTION: We report that the coincidence of ovarian tumor and pregnancy poses significant challenges that are more pronounced if the pregnancy is ectopic. CASE PRESENTATION: Here, we report a rare and interesting case of a 24-year-old nulliparous Spanish woman who experienced the coincidental occurrence of left tubal pregnancy and dysgerminoma in the right ovary. The corpus luteum settled in the right ovary. A right adnexectomy and left linear salpingostomy were performed. Remarkably, our patient became pregnant spontaneously after surgery. The pregnancy occurred prior to starting chemotherapy, and the intra-uterine pregnancy was carried to term; later, she also had another normal pregnancy. Our patient has done well without chemotherapy. CONCLUSIONS: Our report on the challenges of diagnosis and treatment faced in this case can help clinicians better understand and manage these pathologies. We have not found any similar cases in the literature.
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BACKGROUND AND AIMS: Archipelagos are unique systems for studying evolutionary processes promoting diversification and speciation. The islands of the Mediterranean basin are major areas of plant richness, including a high proportion of narrow endemics. Many endemic plants are currently found in rocky habitats, showing varying patterns of habitat occupancy at different spatial scales throughout their range. The aim of the present study was to understand the impact of varying patterns of population distribution on genetic diversity and structure to shed light on demographic and evolutionary processes leading to population diversification in Crepis triasii, an endemic plant from the eastern Balearic Islands. METHODS: Using allozyme and chloroplast markers, we related patterns of genetic structure and diversity to those of habitat occupancy at a regional (between islands and among populations within islands) and landscape (population size and connectivity) scale. KEY RESULTS: Genetic diversity was highly structured both at the regional and at the landscape level, and was positively correlated with population connectivity in the landscape. Populations located in small isolated mountains and coastal areas, with restricted patterns of regional occupancy, were genetically less diverse and much more differentiated. In addition, more isolated populations had stronger fine-scale genetic structure than well-connected ones. Changes in habitat availability and quality arising from marine transgressions during the Quaternary, as well as progressive fragmentation associated with the aridification of the climate since the last glaciation, are the most plausible factors leading to the observed patterns of genetic diversity and structure. CONCLUSIONS: Our results emphasize the importance of gene flow in preventing genetic erosion and maintaining the evolutionary potential of populations. They also agree with recent studies highlighting the importance of restricted gene flow and genetic drift as drivers of plant evolution in Mediterranean continental islands.
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Crepis/genética , Especiação Genética , Evolução Biológica , Ecossistema , Evolução Molecular , Fluxo Gênico , Marcadores Genéticos , Variação Genética , Genética Populacional , EspanhaRESUMO
The female gubernaculum is an embryonic structure that gives rise to the uterine round ligament and seems to be important in Müllerian development. In the absence of androgens and anti-Müllerian hormone, the paramesonephric or Müllerian ducts complete their invagination and development, interfering with the connection of the tissue column that begins at the inguinal cone (the gubernaculum) and targets the mesonephric duct and caudal ligament of the gonad. The gubernaculum then grows over the Müllerian ducts, incorporating its muscular fibres. Outside and above this point, the Müllerian ducts give rise to the Fallopian tubes, whereas medially to the point of insertion of the gubernaculum, the Müllerian ducts develop into the normal uterus, the adequate formation of which is also induced by the mesonephric ducts. Diverse human anatomical and physiological characteristics such as the simplex uterus, as well as pathological conditions and certain female genital malformations, could be related to gubernaculum dysfunction. The main conclusions in this article are: (1) The female gubernaculum is the origin of the uterine round ligament but probably not of the uteroovarian ligament. Gubernacula are composed of muscular fibres that probably derive from the abdominal wall and that, when fixed and fused with the Müllerian ducts, allow or induce, together with the mesonephric ducts, the adequate development and formation of the uterus. (2) The female gubernaculum seems to be responsible for many of the specific human characteristics of Müllerian development, including the uterus simplex, the anteflexion and low intra-abdominal position of the uterus, and the disposition of uterine muscular fibres. (3) The female gubernaculum seems to be related to pathologies arising from the round ligaments and inguinal hernia. Likewise, certain uterine malformations (e.g., didelphys uterus, Rokitansky syndrome) and accessory and cavitated uterine masses might be related to gubernaculum dysfunction.
Assuntos
Desenvolvimento Embrionário , Genitália Feminina/anormalidades , Genitália Feminina/embriologia , Canal Inguinal/embriologia , Animais , Feminino , Humanos , Ductos Paramesonéfricos/anormalidades , Ductos Paramesonéfricos/embriologia , Ligamento Redondo do Útero/anormalidades , Ligamento Redondo do Útero/embriologia , Útero/anormalidades , Útero/embriologiaRESUMO
OBJECTIVE: To present clinical cases of women who had an accessory and cavitated noncommunicating uterine mass with functioning endometrium associated with a normal uterus, suggestive of a new type of Müllerian anomaly. METHODS: We report on five institutional cases: four cases of cavitated accessory uterine mass and a case of true adenomyoma. A review of the literature was performed by looking for these terms and others related in MEDLINE. RESULTS: Including ours, there are 18 cases in the literature showing an accessory cystic cavity lined by endometrioid epithelium with an otherwise normal uterus. Another 11 cases only partially fulfilled the inclusion criteria. All of the first cases were in young women presenting with severe dysmenorrhea (n=4). Generally, the tumor was located in the anterior wall of the uterus at the level of insertion of the round ligament. It presents a certain similarity with the cavitated true adenomyomas observed in older women in whom the endometrial lining of the cystic cavity is generally absent. For differential diagnosis with cavitated noncommunicating rudimentary uterine horns, hysterosalpingography showing a normal eutopic uterine cavity is decisive. CONCLUSION: Noncommunicating accessory uterine cavities and isolated cystic adenomyomas correspond to the same pathology: cavitated accessory uterine mass associated with an otherwise normal uterus. They present problems of differential diagnosis with true cavitated adenomyomas and cavitated rudimentary uterine horns. Accessory uterine mass could be caused by duplication and persistence of ductal Müllerian tissue in a critical area at the attachment level of the round ligament, possibly related to a gubernaculum dysfunction. LEVEL OF EVIDENCE: III.
Assuntos
Ductos Paramesonéfricos/anormalidades , Útero/anormalidades , Adenomioma/diagnóstico , Adenomioma/patologia , Adolescente , Adulto , Diagnóstico Diferencial , Feminino , Humanos , Neoplasias Uterinas/diagnóstico , Neoplasias Uterinas/patologia , Adulto JovemRESUMO
Tree species are thought to be relatively resistant to habitat fragmentation because of their longevity and their aptitude for extensive gene flow, although recent empirical studies have reported negative genetic consequences, in particular after long-term habitat fragmentation in European temperate regions. Yet the response of each species to habitat loss may differ greatly depending on their biological attributes, in particular seed dispersal ability. In this study, we used demographic and molecular data to investigate the genetic consequences of chronic habitat fragmentation in remnant populations of Taxus baccata in the Montseny Mountains, northeast Spain. The age structure of populations revealed demographic bottlenecks and recruitment events associated with exploitation and management practices. We found a strong genetic structure, both at the landscape and within-population levels. We also detected high levels of inbreeding for a strictly outcrossing species. Chronic forest fragmentation resulting from long-term exploitation in the Montseny Mountains seems the most plausible explanation for the strong genetic structure observed. Our results support the view that, contrary to some predictions, tree species are not buffered from the adverse effects of habitat fragmentation, even in the case of species with a high dispersal potential.
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OBJECTIVE: To analyze the clinical, therapeutic, and pathologic features of published cases presenting primary squamous cell carcinoma (SCC) of the ovary associated with endometriosis. METHODS: A case report, 15 cases of infiltrating SCC of the ovary associated with or arising from endometriosis, and 1 case of synchronous carcinoma in situ in the cervix and ovary from a review of the literature were studied. RESULTS: Young age, advanced stage of the disease, and hypogastric pain were frequent at the time of diagnosis. There was no ascites, but infiltration of neighboring organs was common. The tumor was associated with 80% patient mortality in the first few months. Adjuvant chemotherapy with paclitaxel and carboplatin or cisplatin appeared to improve the results. CONCLUSION: Primary SCC of the ovary associated with endometriosis is extremely rare and has a poor prognosis. The best therapeutic results are obtained with paclitaxel and carboplatin or cisplatin after radical surgery.
Assuntos
Carcinoma de Células Escamosas/patologia , Endometriose/complicações , Neoplasias Ovarianas/patologia , Dor Abdominal/etiologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carboplatina/administração & dosagem , Carcinoma de Células Escamosas/etiologia , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/terapia , Quimioterapia Adjuvante/métodos , Cisplatino/administração & dosagem , Endometriose/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Primárias Múltiplas , Neoplasias Ovarianas/etiologia , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/terapia , Paclitaxel/administração & dosagem , Prognóstico , Neoplasias do Colo do Útero/patologiaRESUMO
Using the wind-dispersed plant Mycelis muralis, we examined how landscape fragmentation affects variation in seed traits contributing to dispersal. Inverse terminal velocity (Vt(-1)) of field-collected achenes was used as a proxy for individual seed dispersal ability. We related this measure to different metrics of landscape connectivity, at two spatial scales: in a detailed analysis of eight landscapes in Spain and along a latitudinal gradient using 29 landscapes across three European regions. In the highly patchy Spanish landscapes, seed Vt(-1)increased significantly with increasing connectivity. A common garden experiment suggested that differences in Vt(-1) may be in part genetically based. The Vt(-1) was also found to increase with landscape occupancy, a coarser measure of connectivity, on a much broader (European) scale. Finally, Vt(-1)was found to increase along a south-north latitudinal gradient. Our results for M. muralis are consistent with 'Darwin's wind dispersal hypothesis' that high cost of dispersal may select for lower dispersal ability in fragmented landscapes, as well as with the 'leading edge hypothesis' that most recently colonized populations harbour more dispersive phenotypes.
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Asteraceae/fisiologia , Ecossistema , Modelos Biológicos , Sementes/fisiologia , Vento , Característica Quantitativa Herdável , EspanhaRESUMO
The importance of the Mediterranean Basin as a long-term reservoir of biological diversity has been widely recognized, although much less effort has been devoted to understanding processes that allow species to persist in this area. Ramonda myconi (Gesneriaceae) is a Tertiary relict plant species restricted to the NE Iberian Peninsula. We used RAPD and chloroplast markers to assess the patterns of genetic structure in eight mountain regions covering almost the full species range, to identify the main historical processes that have shaped its current distribution and to infer the number and location of putative glacial refugia. While no cpDNA variation was detected, the species had relatively high levels of RAPD variation. Maximum levels of diversity were found within populations (71%), but there was also a significant differentiation between geographical regions (20%) and among populations within regions (9%). A spatial AMOVA identified three main groups of populations, corresponding to previously recognized centers of endemism and species richness. In addition, we found a marked geographical pattern of decreasing genetic diversity and increasing population differentiation from west to east. Our results support a complex phylogeographic scenario in the Iberian Peninsula of "refugia-within-refugia" and suggest that the higher diversity observed in western regions might be associated with prolonged and more stable climatic conditions in this area during the Quaternary.
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We present a clinical case of a patient with left renal agenesis and ipsilateral blind hemivagina who also had one or more atretic ectopic ureters opening into supposed mesonephric duct, which in turn opened into, or joined onto, the ipsilateral hemicervix, continuing with the blind hemivagina. The diagram of this complex genitourinary malformation would strongly support our hypothesis of the embryology of the human vagina as deriving from the Wolffian ducts and the Mullerian tubercle.
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Anormalidades Múltiplas/diagnóstico por imagem , Genitália Feminina/anormalidades , Sistema Urinário/anormalidades , Anormalidades Urogenitais/diagnóstico por imagem , Anormalidades Múltiplas/patologia , Anormalidades Múltiplas/cirurgia , Adulto , Feminino , Genitália Feminina/diagnóstico por imagem , Genitália Feminina/cirurgia , Humanos , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Sistema Urinário/patologia , Sistema Urinário/cirurgia , Anormalidades Urogenitais/patologia , Anormalidades Urogenitais/cirurgia , Procedimentos Cirúrgicos Urogenitais/métodos , UrografiaRESUMO
We report a 52 years old male admitted for fever lasting one month, dry cough, headache and malaise. Initial laboratory work up showed an AST of 172 U/l, and ALT of 252 U/l, a GGT of 353 U/l and alkaline phosphatases of 952 U/l. An abdominal CAT scan disclosed a mild hepatosplenomegaly. A liver biopsy showed a granulomatous hepatitis. During the evolution, the patient had a left testicle swelling with darkening of the surrounding skin. A testicular ultrasound showed a bilateral orchiepidydimitis. The patient was treated with non steroidal anti-inflammatory drugs and fever subsided. Three months later, these drugs were discontinued and the patient remained asymptomatic and with normal laboratory values until 36 months of follow up
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Humanos , Masculino , Pessoa de Meia-Idade , Orquite , Epididimite , Exantema , Febre de Causa Desconhecida , Hepatite , Anti-Inflamatórios não EsteroidesRESUMO
Analyses of RAPD profiles from 17 populations of the Hippocrepis balearica complex revealed a highly structured geographic pattern, not only among continental-insular areas but also within the eastern Balearic islands. In marked contrast to previous morphometric results, a clear separation between continental and insular samples was found, and intermediates between H. balearica and H. valentina samples were not detected. Molecular data indicated that western and eastern Balearic populations of the complex (H. grosii and H. balearica) were more closely related to each other than to continental populations (H. valentina). Multivariate analyses of the RAPD data clearly indicated that the similarities between continental and eastern Balearic samples of the H. balearica complex recovered by morphometric methods are due either to parallel evolution or to retention of plesiomorphic features.
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DNA de Plantas/genética , Fabaceae/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico/métodos , Impressões Digitais de DNA/métodos , Evolução Molecular , Fabaceae/classificação , Fabaceae/crescimento & desenvolvimento , Geografia , Região do Mediterrâneo , FilogeniaRESUMO
Lysimachia minoricensis is one of the few Mediterranean endemic plants (Minorca, Balearic islands) that has gone extinct in the wild but which persists as extant germplasm or cultivated plants in several botanical gardens. Reproductive features (seed set, number of seeds per capsule, seed weight) and germination responses to constant temperatures, sea water and dry-heat pre-treatments were investigated to determine the extent to which they may have influenced the extinction of the species. Seed set in Lysimachia is not dependent on pollinators, suggesting a functional selfer breeding system. Most plants produced a large mean number of fruits (23.2) and seeds (466), and the mean production of seeds per individual was estimated to be almost 1,100. Overall, no highly specific requirements were observed for seed germination. Seed germination was not inhibited in the dark, and a high germinability (over 87% in all cases) was recorded in most experiments, with the exception of those performed at low temperatures (5 and 10 degrees C). These data suggest that fertility and seed viability were not the major causes of extinction. The high reproductive performance of L. minoricensis is in striking contrast to its status as a wild-extinct plant, suggesting that extrinsic factors were responsible for its extinction.
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Conservação dos Recursos Naturais/métodos , Germinação/fisiologia , Primulaceae/fisiologia , Sementes/crescimento & desenvolvimento , Escuridão , Frutas/crescimento & desenvolvimento , Germinação/efeitos da radiação , Temperatura Alta , Região do Mediterrâneo , Reprodução/fisiologia , Água do MarRESUMO
We report a 52 years old male admitted for fever lasting one month, dry cough, headache and malaise. Initial laboratory work up showed an AST of 172 U/l, and ALT of 252 U/l, a GGT of 353 U/l and alkaline phosphatases of 952 U/l. An abdominal CAT scan disclosed a mild hepatosplenomegaly. A liver biopsy showed a granulomatous hepatitis. During the evolution, the patient had a left testicle swelling with darkening of the surrounding skin. A testicular ultrasound showed a bilateral orchiepidydimitis. The patient was treated with non steroidal anti-inflammatory drugs and fever subsided. Three months later, these drugs were discontinued and the patient remained asymptomatic and with normal laboratory values until 36 months of follow up.