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1.
Nat Commun ; 15(1): 1237, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38336937

RESUMO

Since the insights by Charles Darwin, heterostyly, a floral polymorphism with morphs bearing stigmas and anthers at reciprocal heights, has become a model system for the study of natural selection. Based on his archetypal heterostylous flower, including regular symmetry, few stamens and a tube, Darwin hypothesised that heterostyly evolved to promote outcrossing through efficient pollen transfer between morphs involving different areas of a pollinator's body, thus proposing his seminal pollination-precision hypothesis. Here we update the number of heterostylous and other style-length polymorphic taxa to 247 genera belonging to 34 families, notably expanding known cases by 20%. Using phylogenetic and comparative analyses across the angiosperms, we show numerous independent origins of style-length polymorphism associated with actinomorphic, tubular flowers with a low number of sex organs, stamens fused to the corolla, and pollination by long-tongued insects. These associations provide support for the Darwinian pollination-precision hypothesis as a basis for convergent evolution of heterostyly across angiosperms.


Assuntos
Magnoliopsida , Polinização , Humanos , Polinização/genética , Filogenia , Magnoliopsida/genética , Pólen , Polimorfismo Genético , Flores/genética
2.
BMC Pulm Med ; 22(1): 160, 2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35473605

RESUMO

BACKGROUND: Smoke exposure culminates as a progressive lung complication involving airway inflammation and remodeling. While primary smoke poses the greatest risk, nearly half of the US population is also at risk due to exposure to secondhand smoke (SHS). METHODS: We used WT, RAGE-/- (KO), and Tet-inducible lung-specific RAGE overexpressing transgenic (TG) mice to study the role of RAGE during short-term responses to SHS. We evaluated SHS effects in mice with and without semi-synthetic glycosaminoglycan ethers (SAGEs), which are anionic, partially lipophilic sulfated polysaccharide derivatives known to inhibit RAGE signaling. TG Mice were weaned and fed doxycycline to induce RAGE at postnatal day (PN) 30. At PN40, mice from each line were exposed to room air (RA) or SHS from three Kentucky 3R4F research cigarettes via a nose-only delivery system (Scireq Scientific, Montreal, Canada) five days a week and i.p. injections of PBS or SAGE (30 mg/kg body weight) occurred three times per week from PN40-70 before mice were sacrificed on PN70. RESULTS: RAGE mRNA and protein expression was elevated following SHS exposure of control and TG mice and not detected in RAGE KO mice. Bronchoalveolar lavage fluid (BALF) analysis revealed RAGE-mediated influence on inflammatory cell diapedesis, total protein, and pro-inflammatory mediators following exposure. Lung histological assessment revealed indistinguishable morphology following exposure, yet parenchymal apoptosis was increased. Inflammatory signaling intermediates such as Ras and NF-κB, as well as downstream responses were influenced by the availability of RAGE, as evidenced by RAGE KO and SAGE treatment. CONCLUSIONS: These data provide fascinating insight suggesting therapeutic potential for the use of RAGE inhibitors in lungs exposed to SHS smoke.


Assuntos
Pneumonia , Poluição por Fumaça de Tabaco , Animais , Éteres , Glicosaminoglicanos , Humanos , Camundongos , Camundongos Transgênicos , Pneumonia/patologia , Receptor para Produtos Finais de Glicação Avançada/genética , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Poluição por Fumaça de Tabaco/efeitos adversos
3.
J Neurol ; 269(8): 3990-3999, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35488918

RESUMO

Fatigue in its many forms of physical, mental, and psychosocial exhaustion is a common symptom of post-COVID-19 condition, also known as "Long COVID." Persistent fatigue in COVID-19 patients is frequently accompanied by cognitive dysfunction and neuropsychiatric symptoms; however, less is known about the relationships between these components of post-COVID-19 condition and fatigue itself. Consequently, the present study sought to (1) distinguish the types of fatigue experienced by participants, and (2) investigate whether cognitive deficits across various domains and neuropsychiatric conditions predicted these different types of fatigue. The study included 136 COVID-19 patients referred for neuropsychological evaluation due to cognitive complaints 8 months on average after SARS-CoV-2 infection. Measures included self-reported fatigue (physical, cognitive, and psychosocial), neuropsychiatric questionnaires (assessing symptoms of depression, anxiety, apathy, and executive functioning), a comprehensive neuropsychological assessment, and self-reported quality of life and everyday functioning. Results showed that reports of clinical significant fatigue were pervasive in our sample (82.3% of participants), with physical fatigue rated highest on average relative to the subscale maximum. Elevated levels of apathy, anxiety, and executive dysfunction in neuropsychiatric measures along with executive and attentional difficulties on cognitive tests were found to be consistently important predictors among different types of fatigue. This implicates both cognitive and neuropsychiatric symptoms as predictors of fatigue in post-COVID-19 condition, and stresses the importance of a holistic approach in assessing and considering potential treatment for COVID-19 patients experiencing fatigue.


Assuntos
COVID-19 , Disfunção Cognitiva , COVID-19/complicações , Cognição , Disfunção Cognitiva/diagnóstico , Depressão/diagnóstico , Fadiga/diagnóstico , Humanos , Qualidade de Vida , SARS-CoV-2 , Síndrome de COVID-19 Pós-Aguda
4.
Am J Bot ; 104(1): 50-61, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28039130

RESUMO

PREMISE OF THE STUDY: Populations of heterostylous species are characterized by two or three floral morphs with reciprocal positioning of stigmas and anthers. Theoretical models predict equal morph frequencies (isoplethy) when disassortative mating is prevalent in populations, but biased morph ratios may occur when variation in the expression of heterostyly causes deviations from intermorph mating. METHODS: We explore the role of sex-organ deployment in governing morph ratios in two closely related genera of Boraginaceae, exhibiting striking variation in floral traits associated with the heterostylous syndrome. We sampled 66 populations of six species of Glandora and 39 populations of three species of Lithodora across their distributional range in the Mediterranean. In each population we estimated morph ratios and measured several floral traits. We used phylogenetically corrected and noncorrected regressions to test the hypothesis that differences in sex-organ reciprocity and herkogamy are associated with deviations from isoplethy. KEY RESULTS: Biased morph ratios occurred in 24% of populations, particularly in Lithodora. Populations biased for the long-styled morph (L-morph) were more frequent than the short-styled morph (S-morph). Distylous species were less likely to exhibit biased ratios than species with stigma-height dimorphism. In Lithodora fruticosa, a species lacking reciprocity, decreased herkogamy in the S-morph was associated with increasing L-morph bias, perhaps resulting from self-interference. CONCLUSION: Striking variation in the expression of heterostyly in Glandora and Lithodora is associated with biased morph ratios, which probably result from pollinator-mediated mating asymmetries within populations.


Assuntos
Boraginaceae/fisiologia , Flores/fisiologia , Pólen/fisiologia , Polinização/fisiologia , Evolução Biológica , Boraginaceae/anatomia & histologia , Boraginaceae/classificação , Flores/anatomia & histologia , Geografia , Região do Mediterrâneo , Modelos Anatômicos , Pólen/anatomia & histologia , Reprodução/fisiologia , Especificidade da Espécie
5.
Med Clin (Barc) ; 144(2): 51-4, 2015 Jan 20.
Artigo em Espanhol | MEDLINE | ID: mdl-24820904

RESUMO

BACKGROUND AND OBJECTIVE: In this study, 123 recordings of blood pressure (BP) obtained by ambulatory BP monitoring were analyzed. These recordings were measured in 2011 in patients from a Spanish tertiary university hospital. All participating patients were treated with 2, 3 or 4 anti-hypertensive drugs. The main aim of this study was to determine differences in BP control, if any, depending on the medication schedule. Thus, BP levels were studied at 3 periods of the day: activity hours, rest hours and 24h. PATIENTS AND METHOD: We compared subjects taking all anti-hypertensive agents during the day (n=70, group 1) with those taking at least one at night (n=53, group 2). RESULTS: Significant differences were found on diastolic BP, where group 2 patients had lower levels at activity, 24h periods and sleep-time. Even if it was not statistically significant, lower levels of systolic BP from group 2 were also observed at activity and 24h periods as well as lower levels of systolic, diastolic and mean BP at rest hours periods. There were also significant group differences in relation to the number of prescribed agents (with the mean being higher for group 2) and the type of agent (beta-blockers and calcium antagonists were more prevalent in group 2). Nevertheless, the multivariate regression analysis done taking into account these variables did not change the observed statistical significance. CONCLUSION: The administration of anti-hypertensive drugs at night could be associated with lower BP levels.


Assuntos
Anti-Hipertensivos/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Cronofarmacoterapia , Hipertensão/tratamento farmacológico , Idoso , Anti-Hipertensivos/farmacocinética , Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea/fisiologia , Monitorização Ambulatorial da Pressão Arterial , Doenças Cardiovasculares/epidemiologia , Comorbidade , Feminino , Humanos , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Descanso , Estudos Retrospectivos , Apneia Obstrutiva do Sono/epidemiologia , Fumar/epidemiologia , Vigília
6.
Evolution ; 67(7): 2072-82, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23815660

RESUMO

Darwin's early work on heterostyly and related style polymorphisms (the presence of two or three style morphs within a population) generated much interest to understand how precise interactions between ecological and genetic mechanisms influence the evolution of floral diversity. Here we tested three key hypotheses proposed to explain the evolution of heterostyly: (i) the presence of self-incompatibility; (ii) the role of pollinators in promoting dissasortative mating; and (iii) floral architecture, which restricts pollinators' movements and ensures more exact pollen deposition on their bodies. We combined data from experiments, field observations, and published studies to test whether evolution of style polymorphism in Narcissus is driven by the incompatibility system, pollinator guilds, or floral architecture, within a phylogenetic framework. Neither differences in pollinator environment nor the presence of genetic self-incompatibility were correlated with presence of style polymorphism. However, our results indicate that the evolution of style polymorphism was driven by the presence of a narrow and long floral tube.


Assuntos
Evolução Biológica , Narcissus/anatomia & histologia , Narcissus/genética , Flores/anatomia & histologia , Flores/fisiologia , Narcissus/fisiologia , Filogenia , Pólen/fisiologia , Polinização , Polimorfismo Genético , Autoincompatibilidade em Angiospermas
7.
Syst Biol Reprod Med ; 56(1): 62-73, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20170287

RESUMO

Intrauterine growth restriction (IUGR) is a disease responsible for neonatal morbidity and mortality and perinatal death affecting 8% of all pregnancies. In sheep, IUGR that mimics the human IUGR disease closely can be brought on by environmental hyperthermia. Endothelial nitric oxidase synthase (eNOS) and nitric oxide (NO) are important in the regulation of blood flow in the fetal-placental circulation and are modulated by several factors including hypoxia. eNOS activity is also regulated by the phosphorylation of ERK1/2 and AKT proteins in various tissues. In a hyperthermic (HT) ovine model of IUGR with systemic hypertension and increased blood flow resistance, our objective was to determine the relationship between p-ERK, p-AKT, eNOS, and NO concentrations in the placenta, uterine, and umbilical vessels at mid-gestation and near-term. Eight pregnant ewes were exposed to hyperthermic conditions for either 55 or 80 days to induce IUGR. Sheep necropsies were performed at mid-gestation and near-term for collection of placentomes, umbilical vessels, and the uterine artery. Tissues were assessed for eNOS mRNA and protein, and p-ERK and p-AKT protein. Blood was collected for NO determination at the time of necropsy. Placental insufficiency and IUGR (PI-IUGR) pregnancies demonstrated: 1) reduced placental weight at mid-gestation and reduced placental and fetal weight near-term, 2) no changes in eNOS protein concentration in the uterine artery and umbilical vessels, but an increase in NO in umbilical vein blood at both time points, 3) no significant changes in signal transduction makers (ERK/AKT) in placental tissue at mid-gestation but a significant increase near-term in cotyledon tissues, and 4) an increase in p-AKT in the uterine vessels at term. The near-term findings of increased placental p-ERK and p-AKT proteins and umbilical vein NO concentration suggest one mechanism responsible for the increase in placental eNOS previously described in this PI-IUGR model characterized by fetal systemic hypertension and abnormal umbilical artery Doppler velocimetry.


Assuntos
MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Retardo do Crescimento Fetal/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Óxido Nítrico/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ovinos/fisiologia , Animais , Modelos Animais de Doenças , Feminino , Retardo do Crescimento Fetal/genética , Regulação da Expressão Gênica no Desenvolvimento , Idade Gestacional , Hipertermia Induzida , Óxido Nítrico Sintase Tipo III/genética , Placenta/irrigação sanguínea , Placenta/metabolismo , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais , Cordão Umbilical/metabolismo , Artéria Uterina/metabolismo
8.
New Phytol ; 171(3): 553-67, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16866958

RESUMO

Here we analysed the role played by breeding systems and pollinators in the evolution of heterostyly by testing whether evolution towards heterostyly is associated with style polymorphism and changes in pollinator proficiency or breeding system variation (Darwinian hypothesis). We studied pollinators, pollen-transfer efficiency, and incompatibility systems in all seven species of Narcissus sect. Apodanthi for which we also obtained chloroplast DNA (cpDNA) sequences from three spacers to infer phylogenetic relationships. Five species are self-incompatible and within-morph cross-compatible. Heterostylous (Narcissus albimarginatus) and style-dimorphic (Narcissus cuatrecasasii) species that have a high degree of reciprocity in stigma and anther height are primarily pollinated by solitary bees. The style-monomorphic species (Narcissus watieri) and the style-dimorphic species with the least stigma-anther reciprocity (Narcissus rupicola) are both self-compatible and pollinated by butterflies, moths and hover flies. Phylogenetic reconstruction of character transitions indicates that the shift from style dimorphism to distyly is associated with a shift to bee pollination. Pollination by lepidopterans and flies is associated with stable style dimorphism and monomorphism. Evolution and maintenance of style polymorphisms in this group of species are independent of incompatibility systems. Taken together, our results strongly support the pollinator-based model for evolution of heterostyly and style length polymorphisms in general.


Assuntos
Cruzamento , Insetos/fisiologia , Modelos Biológicos , Narcissus/fisiologia , Pólen/fisiologia , Animais , Narcissus/classificação , Narcissus/genética , Filogenia , Sementes/fisiologia
9.
New Phytol ; 171(3): 581-90, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16866960

RESUMO

Here, we studied the floral morphology and pollination of the distylous plant Linum suffruticosum (Linaceae) in southern Spain. We observed a previously unreported form of distyly that involved twisting and bending of styles and stamens during floral development to achieve three-dimensional reciprocity of anthers and stigmas in the long-styled (pin) and short-styled (thrum) morphs. This developmental pattern causes pin pollen to be placed on the underside of pollinating Usia flies (Bombyliidae), and thrum pollen to be placed on the top of the thorax and abdomen. The pin stigmas contact the flies on the dorsum, apparently picking up predominantly thrum pollen, and the thrum stigmas contact the flies on the ventral surface, apparently picking up predominantly pin pollen. This form of heterostyly would appear on morphological grounds to be far more efficient in dispersing pollen between compatible morphs than the typical pin-thrum system. If so, this plant fits Darwin's prediction of efficient pollen flow between heterostylous morphs more closely than anything Darwin himself reported. Molecular phylogenetic analyses indicate that this form of heterostyly evolved in a lineage that already had typical heterostyly. The analyses also indicate that there have been several independent origins of heterostyly in Linum and at least one reversal to stylar monomorphism.


Assuntos
Linho/fisiologia , Flores/anatomia & histologia , Flores/fisiologia , Animais , DNA de Plantas/genética , Frutas/fisiologia , Insetos/fisiologia , Modelos Biológicos , Filogenia , Pólen/fisiologia , Análise de Sequência de DNA
10.
An. Fac. Med. (Perú) ; 57(3): 188-95, 1996.
Artigo em Espanhol | LILACS | ID: lil-208442

RESUMO

Se plantea que el sector salud en el punto más bajo de la crisis, entre 1988 y 1992, ante la omisión del estado y el colapso operativo de los servicios públicos, inició una gran transformación pasiva del sistema sanitario peruano, una reforma sanitaria silenciosa, en que la política de salud real no surgió tanto de dispositivos legales sino como resultante del conflicto y encuentro bastante espontáneo de los actores sanitarios. Luego, a partir de 1993 se pasó a una segunda etapa de lenta recomposición sin rumbo general aún, empezándose a revivar la tendencia de retroceso y descomposición anterior. Pero en ninguna de estas dos etapas se ha detenido la reforma sanitaria silenciosa, que se desarrolla como un proceso de reconfiguración desregulada del sistema sanitario peruano. Nueve grandes cambios ha vivido el sector salud bajo esta modalidad de reforma no sistémica o por acumulación: 1. La reconversión paulatina de los hospitales del MINSA en entidades semi-privadas; 2. La multiplicación de presiones cruzadas sobre la demanda en salud y su resegmentación contínua conforme los cambios en la oferta de servicios; 3. La reforma subsectorial del IPSS en el quinquenio 1990-95, una modernización a marcha forzada; 4. La reconstitución del secotr gran privado en salud con los seguros privados y sus nuevas modalidades operativas; 5. La emergencia del nuevo subsector privado sin fines de lucro, con la acción de la iglesia y de las ONGs; 6. El cambio en los procesos de trabajo médico y el tránsito último de la crisis de empleo a la ocupación plena; 7. La dualización de la atención médica y el refugio de los sectores desprotegidos en la automedicación y medicina tradicional; 8. La ampliación del financiamiento y de la cooperación externa a partir de 1993; 9. La repotenciación de la red periférica y el despliegue de múltiples iniciativas parciales (salud básica para todos, proyectos y programas, etc.), expresiones de reformas aún sin reforma.


Assuntos
Reforma dos Serviços de Saúde , Reforma dos Serviços de Saúde/economia , Reforma dos Serviços de Saúde/organização & administração , Reforma dos Serviços de Saúde/tendências , Serviços de Saúde , Cobertura de Serviços de Saúde
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