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1.
BMC Med Inform Decis Mak ; 20(1): 78, 2020 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-32349746

RESUMO

BACKGROUND: Screening with prostate-specific antigen (PSA) test for prostate cancer is considered a preference sensitive decision; meaning it does not only depend on what is best from a medical point of view, but also from a patient value standpoint. Decision aids are evidence-based tools which are shown to help people feel clearer about their values; therefore it has been advocated that decision aids should contain a specific values clarification method (VCM). VCMs may be either implicit or explicit, but the evidence concerning the best method is scarce. We aim to compare the perceived clarity of personal values in men considering PSA screening using decision aids with no VCM versus an implicit VCM versus an explicit VCM. METHODS: Male factory employees from an industrial facility in the Northern region of Portugal aged 50 to 69 years old will be randomly assigned to one of three decision aid groups used to support prostate cancer screening decisions: (i) decision aid with information only (control), (ii) decision aid with information plus an implicit VCM, (iii) decision aid with information plus an explicit VCM. Men will be allowed release time from work to attend a session at their workplace. After a brief oral presentation, those willing to participate in the study will fill the baseline questionnaire, plus a 5 point-Likert scale question about intentions to undergo screening, and will then receive the intervention materials to complete. We estimated a total sample size of 276 participants; with 92 in each group. The primary outcome will be the perceived clarity of personal values assessed by the Portuguese validated translation of the three subscales of the Decisional Conflict Scale. Secondary outcomes will be intention to be screened (before and after the intervention), the total score from the Decisional Conflict Scale and the self-report of having or not undergone screening at 6 months. DISCUSSION: This study will add to the body of evidence on the role of decision aids to support health preference-sensitive choices and provide further insight on the impact of different methods for eliciting people's values embedded within a decision aid. TRIAL REGISTRATION: NCT03988673 - clinicalTrials.gov (2019/06/17).


Assuntos
Tomada de Decisão Compartilhada , Técnicas de Apoio para a Decisão , Participação do Paciente , Antígeno Prostático Específico , Idoso , Tomada de Decisões , Detecção Precoce de Câncer , Humanos , Masculino , Pessoa de Meia-Idade , Portugal , Neoplasias da Próstata , Ensaios Clínicos Controlados Aleatórios como Assunto
2.
Diabet Med ; 36(5): 569-577, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30511764

RESUMO

AIMS: Prospective memory has been long considered a fundamental cognitive ability for optimal medication taking, but the role of prospective memory errors (termed 'slips') in diabetes self-care is unclear. Our aim was to examine associations between prospective memory and medication taking in adults with Type 1 and Type 2 diabetes mellitus. METHODS: Some 901 adults with Type 1 diabetes and 927 with Type 2 diabetes completed a cross-sectional survey focused on the psychological and behavioural aspects of living with diabetes. Respondents reported whether they had forgotten to take their diabetes medication over the previous 14 days. RESULTS: Twenty-four per cent (n = 220) of adults with Type 1 diabetes and 23% (n = 211) with Type 2 diabetes reported that they had forgotten their medication at least once over the previous 14 days. This was associated with more prospective memory slips in adults with Type 1 diabetes [odds ratio (OR) 1.09, 95% confidence interval (CI) 1.05 to 1.13; P < 0.001] and Type 2 diabetes (OR 1.10, 95% CI 1.05 to 1.15; P < 0.001); and with younger age (both groups), insulin pump use (Type 1 diabetes), insulin treatment (Type 2 diabetes), less frequent blood glucose checks (Type 1 diabetes) and higher HbA1c (Type 1 diabetes). CONCLUSIONS: These findings suggest that forgetting medication is relatively common among adults with Type 1 or Type 2 diabetes, and provide preliminary evidence for its relationship with self-reported prospective memory slips.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/epidemiologia , Hipoglicemiantes/uso terapêutico , Transtornos da Memória/epidemiologia , Memória Episódica , Adulto , Idoso , Austrália/epidemiologia , Estudos Transversais , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/psicologia , Feminino , Humanos , Masculino , Transtornos da Memória/complicações , Pessoa de Meia-Idade , Inquéritos e Questionários
3.
Environ Mol Mutagen ; 62(2): 155-164, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33341964

RESUMO

Considering the importance and lack of data of toxicogenomic approaches on occupational exposure to anesthetics, we evaluated possible associations between waste anesthetic gases (WAGs) exposure and biological effects including oxidative stress, DNA damage, inflammation, and transcriptional modulation. The exposed group was constituted by anesthesia providers who were mainly exposed to the anesthetics sevoflurane and isoflurane (10 ppm) and to a lesser degree to nitrous oxide (150 ppm), and the control group was constituted by physicians who had no exposure to WAGs. The oxidative stress markers included oxidized DNA bases (comet assay), malondialdehyde (high-performance liquid chromatography [HPLC]), nitric oxide metabolites (ozone-chemiluminescence), and antioxidative markers, including individual antioxidants (HPLC) and antioxidant defense marker (ferric reducing antioxidant power by spectrophotometry). The inflammatory markers included high-sensitivity C-reactive protein (chemiluminescent immunoassay) and the proinflammatory interleukins IL-6, IL-8 and IL-17A (flow cytometry). Telomere length and gene expression related to DNA repair (hOGG1 and XRCC1), antioxidant defense (NRF2) and inflammation (IL6, IL8 and IL17A) were evaluated by real-time quantitative polymerase chain reaction. No significant differences (p > .0025) between the groups were observed for any parameter evaluated. Thus, under the conditions of the study, the findings suggest that occupational exposure to WAGs is not associated with oxidative stress or inflammation when evaluated in serum/plasma, with DNA damage evaluated in lymphocytes and leucocytes or with molecular modulation assessed in peripheral blood cells in university anesthesia providers. However, it is prudent to reduce WAGs exposure and to increase biomonitoring of all occupationally exposed professionals.


Assuntos
Anestesia/efeitos adversos , Anestésicos Inalatórios/efeitos adversos , Dano ao DNA/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Inflamação/induzido quimicamente , Exposição Ocupacional/efeitos adversos , Estresse Oxidativo/efeitos dos fármacos , Adulto , Idoso , Poluentes Ocupacionais do Ar/efeitos adversos , Antioxidantes/metabolismo , Reparo do DNA/efeitos dos fármacos , Feminino , Hospitais , Humanos , Inflamação/metabolismo , Isoflurano/efeitos adversos , Masculino , Pessoa de Meia-Idade , Óxido Nitroso/efeitos adversos , Sevoflurano/efeitos adversos
4.
Nutrition ; 25(3): 330-9, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19062255

RESUMO

OBJECTIVE: In the present study we evaluated the effect of exercise on the plasma levels of proinflammatory cytokines, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), and the anti-inflammatory molecule uric acid in the Zucker diabetic fatty (ZDF) rats that are more prone to develop type 2 diabetes mellitus. METHODS: Sixteen obese ZDF (Gmi fa/fa) rats (8 wk old, 228.40 +/- 4.05 g) were randomly assigned to one of two groups (n = 8 each): an exercise-trained group and a sedentary one. In addition, 16 lean ZDF (Gmi +/+) rats (8 wk old, 199.00 +/- 3.50 g) were subjected to identical sedentary and exercise conditioning (n = 8 each). Initially, rats swam 15 min/d (5 d/wk) in a 36 degrees C bath. The exercise protocol was gradually increased by 15 min/d until a swimming period of 1 h/d (1 wk) was attained. Thereafter, rats swam 1 h/d, 3 d/wk, for an additional period of 11 wk. Rats were sacrificed 48 h after the last training period and the blood and pancreas were collected. Circulating levels of glucose, glycosylated hemoglobin, total cholesterol, triglycerides, insulin, uric acid, IL-6, and TNF-alpha were assessed. The concentrations of proinflammatory cytokines in the pancreas were also evaluated. RESULTS: In the diabetic ZDF (fa/fa) rats, exercise decreased hyperuricemia (-37.3%) and IL-6 and TNF-alpha levels (-16.9% and -12.7% respectively) and maintained the weight of the pancreas at near normal. Immunohistochemistry revealed a marked decrease in the expression of TNF-alpha and IL-6 in the pancreatic islet cells of ZDF (fa/fa) rats. CONCLUSION: These results indicate that aerobic exercise is anti-inflammatory in nature.


Assuntos
Citocinas/sangue , Diabetes Mellitus Experimental/sangue , Pâncreas/metabolismo , Condicionamento Físico Animal/fisiologia , Ácido Úrico/sangue , Animais , Animais Geneticamente Modificados , Glicemia/análise , Colesterol/sangue , Hemoglobinas Glicadas/análise , Imuno-Histoquímica , Insulina/sangue , Interleucina-6/sangue , Masculino , Tamanho do Órgão , Distribuição Aleatória , Ratos , Ratos Zucker , Natação , Triglicerídeos/sangue , Fator de Necrose Tumoral alfa/sangue
5.
Transplant Proc ; 41(3): 868-73, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19376375

RESUMO

The purpose of this study was to compare the effects of sirolimus (SRL) vs cyclosporine (CsA) concerning the cardiovascular mechanisms hypothetically contributing to hypertension development. Three rat groups were studied: control (vehicle), CsA (5 mg/kg/d), and SRL (1 mg/kg/d). The following parameters were evaluated after 7 weeks of treatment: blood pressured (BP) and heart rate (HR; tail cuff), lipid profile, hematology, plasma and platelet 5-HT and catecholamines (HPLC-ECD), and oxidative equilibrium (serum malondialdehyde [MDA] and total antioxidant status [TAS]). Systolic (SBP) and diastolic blood pressure (DBP) values were higher (P < .001) in both the CsA (146.2 +/- 4.5 and 124.9 +/- 4.5 mm Hg) and SRL (148.9 +/- 4.8 and 126.4 +/- 6.0 mm Hg) groups vs the controls (115.9 +/- 3.3 and 99.1 +/- 2.0 mm Hg). However, HR values were elevated in CsA but not SRL animals. The dyslipidemic pattern of CsA was even more enhanced in the SRL group, with significantly higher low-density lipoprotein cholesterol (LDL-c) and triglyceride (TG) levels vs CsA (P < .05); red blood cells, hematocrit, hemoglobin concentration, mean platelet volume, and platelet distribution width were significantly (P < .05) higher in the SRL vs CsA group. The pro-oxidative profile (increased MDA/TAS) in the CsA group was not reproduced in the SRL cohort. While plasma and platelet 5-HT were elevated in SRL rats, catecholamine content was higher in CsA animals. In conclusion, this study demonstrated that CsA and SRL produce identical hypertensive effects. However, while CsA promotes oxidative stress and sympathetic activation, SRL mainly interferes with lipid profile and hematological parameters. Thus, the hypertensive effects of CsA, a calcineurin inhibitor, and of SRL, an mTOR inhibitor, are associated with impairment of distinct cardiovascular pathways.


Assuntos
Ciclosporina/efeitos adversos , Hipertensão/imunologia , Imunossupressores/efeitos adversos , Sirolimo/efeitos adversos , Animais , Pressão Sanguínea/efeitos dos fármacos , Diástole/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Malondialdeído/sangue , Ratos , Ratos Wistar , Sístole/efeitos dos fármacos
6.
Transplant Proc ; 39(8): 2494-500, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17954157

RESUMO

The aim of this study was to evaluate the effect of cyclosporine (CsA) on oxidative stress as well as the use of a nitric oxide (NO) donor, the organic nitrate isosorbide-5-mononitrate (Is-5-Mn), to prevent or reverse CsA-induced toxicity, namely on the vascular NO-cGMP pathway or on oxidative equilibrium. The following rat groups (n = 8) were tested: (1) a control group; (2) the CsA group (5 mg/kg/d for 7 weeks); (3) the Is-5-Mn group (150 mg/kg/d, twice a day for 7 weeks); (4) the preventive group (Is-5-Mn + CsA) treated for 2 weeks with Is-5-Mn only, and thereafter with both drugs for 7 weeks; (5) the curative group (CsA + Is-5-Mn) beginning 7 weeks after CsA, and following thereafter with both drugs for 5 weeks. The following parameters were evaluated: aortic cNOS activity and cGMP content; plasma levels of lipid peroxidation (malondialdehyde [MDA] levels); antioxidant capacity (glutathione peroxidase [GPx] and superoxide dismutase [SOD] activities, total antioxidant status, and vitamins A, C, and E); and peroxynitrite formation (3-nitrotyrosine [3-NT] content). Is-5-Mn + CsA therapy showed, when compared with the CsA group, total prevention of CsA-induced NO and cGMP attenuation, and no relevant influence on antioxidant indices, as well as on MDA and 3-NT levels. However, when compared with this CsA group, the curative group (CsA + Is-5-Mn) showed NO-cGMP values only partially reversed, and an enhancement in lipid peroxidation (5.6 +/- 1.4 vs 12.78 +/- 3.63 mumol/L; P < .05) and in peroxynitrite formation (16.7% incidence of positives vs 83.3% incidence of positives). Our data suggested that nitrate therapy may provide a valid choice to prevent CsA-induced NO-cGMP decrease, without a negative influence on the oxidative equilibrium. However, when the local environment is adverse, as occurs after CsA therapy, Is-5-Mn seemed to enhance the CsA-induced oxidative stress, promoting even worse deleterious effects, probably through the generation of the cytotoxic ROS peroxynitrite.


Assuntos
Ciclosporina/efeitos adversos , Hipertensão/induzido quimicamente , Tolerância Imunológica/fisiologia , Dinitrato de Isossorbida/análogos & derivados , Doadores de Óxido Nítrico/farmacologia , Estresse Oxidativo/fisiologia , Animais , Tolerância Imunológica/efeitos dos fármacos , Imunossupressores/efeitos adversos , Dinitrato de Isossorbida/farmacologia , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar
7.
J Am Mosq Control Assoc ; 16(2): 66-70, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10901628

RESUMO

Coquillettidia (Coquillettidia) crassipes is recorded for the 1st time in the Territory of Macau, southern China. The systematics of the genus is examined, new species groups are proposed, and a key to subgenera and species groups of Coquillettidia is provided.


Assuntos
Culicidae/classificação , Animais , Culicidae/anatomia & histologia , Feminino , Macau , Masculino
8.
Rev Port Cardiol ; 17(12): 1025-30, 1998 Dec.
Artigo em Português | MEDLINE | ID: mdl-9973864

RESUMO

McNeal and Blevins published the first report of Streptococcus bovis infective endocarditis in 1945. In 1951, McCoy suggested, for the first time, that an association could exist between Group D Streptococcus infective endocarditis and colon carcinoma; this association would be demonstrated later (1977) by Klein and unquestionably confirmed by several posterior works. Due to a clinical case of Streptococcus bovis infective endocarditis, which we had the opportunity of diagnosing, a review is made of the existent literature about the association between infection by this agent and the presence of lesions in the colon. Some recommendations are made in what respects the diagnosis and evaluation of patients with Streptococcus bovis infective endocarditis. Finally, the implications and therapeutic strategies in these patients are discussed.


Assuntos
Insuficiência da Valva Aórtica/diagnóstico , Pólipos do Colo/diagnóstico , Endocardite Bacteriana/diagnóstico , Infecções Estreptocócicas/diagnóstico , Streptococcus bovis , Antibacterianos , Valva Aórtica , Insuficiência da Valva Aórtica/terapia , Pólipos do Colo/terapia , Terapia Combinada , Quimioterapia Combinada/uso terapêutico , Endocardite Bacteriana/terapia , Implante de Prótese de Valva Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Infecções Estreptocócicas/terapia
9.
Rev Bras Enferm ; 54(2): 157-73, 2001.
Artigo em Português | MEDLINE | ID: mdl-12240651

RESUMO

The present study is a socio-historical research. It discusses the association of trained nurses in Brazil, which was represented by opponent groups, and the struggle of these groups in introducing their positions and viewpoints in the professional organizations. The investigation focuses the period of time between the foundation of the Brazilian Association of Nursing (ABEn), in 1926, until the first half of the twentieth century. Despite the political and doctrinal levels, which guided nursing strategies to fortify their positions in this environment, the articulation of opponent groups in the achievement of common professional objectives promoted the regulation and redefinition of the nursing profession.


Assuntos
Sociedades de Enfermagem , Brasil , Educação em Enfermagem , História do Século XX , Modelos de Enfermagem , Objetivos Organizacionais , Política Organizacional , Sistemas Políticos , Escolas de Enfermagem , Sociedades de Enfermagem/organização & administração , Guerra
10.
Rev Bras Enferm ; 50(4): 469-76, 1997.
Artigo em Português | MEDLINE | ID: mdl-10765333

RESUMO

This study was run in a community committee of Nossa Senhora da Aparecida, a surrounding city of Joao Pessoa, Paraiba. It aimed at characterizing nursing practice there and discussing its occurrence. The analysis was run based on eight inhabitants and four nurses speeches through semistructured interviews whose data were collected qualitatively. It focused on the discussion which evolved from questions regarding to education and health from the perspective of exercising citizenship. In the participants of the study representations, education seemed dynamic and implied awareness ... a question of life. Health is comprehended under 3 points of view: the one of welfare, the one of suffering and the one of biological balance. The perspective of citizenship exercise reveals itself sometimes as conformism, through silence or resignation and sometimes as resistance, through the ideal manifestation and courage for fighting for better life condition.


Assuntos
Direitos Civis , Participação da Comunidade , Educação , Nível de Saúde , Enfermagem/organização & administração , Atitude Frente a Saúde , Brasil , Humanos , Pesquisa Metodológica em Enfermagem , Política , Inquéritos e Questionários , Saúde da População Urbana
11.
Rev Bras Enferm ; 50(3): 345-62, 1997.
Artigo em Português | MEDLINE | ID: mdl-9775944

RESUMO

This research is of qualitative nature and it aims at studying nurse's social representations towards nursing and its professional practice and the way they effectively accomplish this practice at Rio de Janeiro Federal University San Francisco de Assisi School Hospital (HESFA/UFRJ). Data were collected from interview, campus observations and documents. Data analysis reveal contradictions and conflicts experienced by nurses in their professional praxis. They are beginning a process of reflection on their professional autonomy: they are sorry for the lack of structure is assisting clients properly; they do believe that researching and political participation are essential for profession development.


Assuntos
Atitude do Pessoal de Saúde , Cuidados de Enfermagem/organização & administração , Recursos Humanos de Enfermagem Hospitalar/psicologia , Brasil , Conflito Psicológico , Hospitais de Ensino , Humanos , Pesquisa Metodológica em Enfermagem , Autonomia Profissional , Inquéritos e Questionários
12.
Neuropeptides ; 46(6): 299-308, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23116540

RESUMO

Neuropeptide Y (NPY) has been implicated in the modulation of important features of neuronal physiology, including calcium homeostasis, neurotransmitter release and excitability. Moreover, NPY has been involved as an important modulator of hippocampal and thalamic circuits, receiving particular attention as an endogenous antiepileptic peptide and as a potential master regulator of feeding behavior. NPY not only inhibits excessive glutamate release (decreasing circuitry hyperexcitability) but also protects neurons from excitotoxic cell death. Furthermore, NPY has been involved in the modulation of the dynamics of dentate gyrus and subventricular zone neural stem cell niches. In both regions, NPY is part of the chemical resource of the neurogenic niche and acts through NPY Y1 receptors to promote neuronal differentiation. Interestingly, NPY is also considered a neuroimmune messenger. In this review, we highlight recent evidences concerning paracrine/autocrine actions of NPY involved in neuroprotection, neurogenesis and neuroinflammation. In summary, the three faces of NPY, discussed in the present review, may contribute to better understand the dynamics and cell fate decision in the brain parenchyma and in restricted areas of neurogenic niches, in health and disease.


Assuntos
Química Encefálica/fisiologia , Inflamação/fisiopatologia , Neurogênese/fisiologia , Neuropeptídeo Y/fisiologia , Fármacos Neuroprotetores , Animais , Morte Celular/efeitos dos fármacos , Giro Denteado/crescimento & desenvolvimento , Giro Denteado/fisiologia , Hipocampo/fisiologia , Humanos , Neuropeptídeo Y/farmacologia , Mucosa Olfatória/crescimento & desenvolvimento , Mucosa Olfatória/fisiologia , Retina/fisiologia
15.
Acta Physiol Hung ; 95(4): 365-81, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19009912

RESUMO

Physical exercise may improve the metabolic and haemodynamic responses, but the beneficial effects seem to depend on intensity, duration and muscular mass recruitment, which may vary between different types of protocols. This study was performed to evaluate the effects of two distinct moderate/long-term aerobic training protocols in the normal Wistar rat, the treadmill running and the swimming, on several important parameters related to cardiovascular (CV) physiological adaptations, namely: lipid profile, haemorheological measures, lipid peroxidation, peripheral serotonergic system (SS) modulation and sympathetic nervous system (SNS) activation. In both groups under training an HDL-c increment versus the sedentary control was demonstrated. There was a noticeable increase in ADP-induced platelet aggregation in the exercised rats, together with higher PDW and MPV values. The RBC patterns were altered in both groups under training; in the swimming one, however, significantly higher RBC and HCT and lower MCH and MCHC values were found, suggesting renovation of the RBCs. Plasma and platelet SS measures were generally higher in both groups under training, being noticeably relevant the 5-HT and 5-HIAA increment in the treadmill. In opposition, concerning the plasma and platelet NE and E concentrations, the rise was remarkably higher in the rats under a swimming protocol. In conclusion, this study demonstrates that, despite the similar beneficial effects on lipid profile, different aerobic exercise protocols may produce distinct CV physiological adaptations. Therefore, treadmill running was more influent than swimming concerning peripheral SS modulation while swimming was more important on SNS activation, thus recommending a judicious choice of the protocol to be tested in works which make use of rat models of exercise to study physiological or pathophysiological conditions.


Assuntos
Adaptação Fisiológica/fisiologia , Corrida/fisiologia , Serotonina/sangue , Natação/fisiologia , Sistema Nervoso Simpático/fisiologia , Glândulas Suprarrenais/anatomia & histologia , Glândulas Suprarrenais/metabolismo , Animais , Aorta/anatomia & histologia , Aorta/metabolismo , Plaquetas/metabolismo , Sistema Cardiovascular/inervação , Epinefrina/sangue , Epinefrina/metabolismo , Teste de Esforço , Coração/anatomia & histologia , Coração/fisiologia , Hemodinâmica/fisiologia , Ácido Hidroxi-Indolacético/sangue , Ácido Hidroxi-Indolacético/metabolismo , Peroxidação de Lipídeos/fisiologia , Lipídeos/sangue , Masculino , Norepinefrina/sangue , Norepinefrina/metabolismo , Tamanho do Órgão , Condicionamento Físico Animal/fisiologia , Agregação Plaquetária/fisiologia , Ratos , Ratos Wistar , Serotonina/metabolismo
16.
J Clin Microbiol ; 42(3): 1316-8, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15004107

RESUMO

The first human isolate of Borrelia lusitaniae recovered from a Portuguese patient with suspected Lyme borreliosis is described. This isolate, from a chronic skin lesion, is also the first human isolate of Borrelia in Portugal. Different phenotypic and molecular methods are used to characterize it.


Assuntos
Infecções por Borrelia/diagnóstico , Borrelia/isolamento & purificação , Sequência de Bases , Borrelia/classificação , DNA Bacteriano/química , DNA Bacteriano/genética , Feminino , Humanos , Íntrons/genética , Pessoa de Meia-Idade , Dados de Sequência Molecular , Filogenia , Portugal
17.
Acta amaz ; 35(1): 23-27, 2005.
Artigo em Inglês | LILACS | ID: lil-420228

RESUMO

Estudou-se a nutrição mineral e as características foliares de duas espécies arbóreas tropicais Switenia macrophylla King (mogno) e Dipteryx odorata Aubl Willd (cumaru) plantadas sob dois ambientes de luz em Presidente Figueiredo - AM, Brasil. Folhas de S. macrophylla e de D. odorata, com três anos de idade, crescidas em plantio a céu aberto (sol) com cerca de 2000 µmol m-2 s-1 e sob cobertura natural (sombra) de plantas de pau-de-balsa (Ochroma pyramidale Cav. Ex Lam. Urb) com cerca de 260 µmol m-2 s-1, foram analisadas quanto à área foliar (AF), a massa da matéria seca (MMS), a área foliar específica (AFE) e aos teores de nutrientes foliares. Verificou-se que, folhas de S. macrophylla, crescidas a pleno sol, apresentaram AF 35% menor quando comparadas com as folhas crescidas na sombra. Por outro lado, nas folhas de D. odorata, não foram observadas diferenças para AF entre os ambientes. Adicionalmente, observou-se que folhas de sombra de S. macrophylla, com base na MMS, foram 50% menores que as folhas de sol, enquanto que no D. odorata não foram observadas diferenças para MMS entre os ambientes. Quanto a AFE, nas folhas de S. macrophylla, verificou-se que as folhas de sol foram três vezes menores quando comparadas com as folhas de sombra, e não houve diferença nas folhas do D. odorata. Quanto aos teores dos nutrientes verificou-se que, independentemente do ambiente, folhas de S. macrophylla apresentaram maiores teores de P e Ca do que aqueles encontrados nas folhas do D. odorata. Os teores de N, K, Fe e Mn diminuíram nas folhas de S. macrophylla crescidas a sombra. Por último, nós sugerimos que a diminuição no teor dos nutrientes foliares pode ter influência negativa sobre o crescimento foliar. Os resultados demonstram que a hipótese testada é verdadeira para características foliares, D. odorata, classificada como clímax, exibiu menor plasticidade para características foliares quando comparada com S. macrophylla, classificada como intermediária.


Assuntos
Nutrientes , Dipteryx
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