RESUMO
Changes to flowering phenology are a key response of plants to climate change. However, we know little about how these changes alter temporal patterns of reproductive overlap (i.e. phenological reassembly). We combined long-term field (1937-2012) and herbarium records (1850-2017) of 68 species in a flowering plant community in central North America and used a novel application of Bayesian quantile regression to estimate changes to flowering season length, altered richness and composition of co-flowering assemblages, and whether phenological shifts exhibit seasonal trends. Across the past century, phenological shifts increased species' flowering durations by 11.5 d on average, which resulted in 94% of species experiencing greater flowering overlap at the community level. Increases to co-flowering were particularly pronounced in autumn, driven by a greater tendency of late season species to shift the ending of flowering later and to increase flowering duration. Our results demonstrate that species-level phenological shifts can result in considerable phenological reassembly and highlight changes to flowering duration as a prominent, yet underappreciated, effect of climate change. The emergence of an autumn co-flowering mode emphasizes that these effects may be season-dependent.
RESUMO
The O (6)-methylguanine-DNA-methyltransferase (MGMT) gene encodes for a DNA repairing enzyme of which silencing by promoter methylation is involved in brain tumorigenesis. MGMT promoter methylation represents a favorable prognostic factor and has been associated with a better response to alkylating agents in glioma and systemic lymphoma. Primary central nervous system lymphoma (PCNSL) is a rare and aggressive extranodal malignant lymphoma. The current standard of care, based on high-dose methotrexate chemotherapy, has improved prognosis but outcome remains poor for a majority of patients. Therapeutic progress in this field is conditioned by limited biological and molecular knowledge about the disease. Temozolomide has recently emerged as an alternative option for PCNSL treatment. We aimed to analyze the MGMT gene methylation status in a series of 24 PCNSLs, to investigate the relationship between methylation status of the gene and immunohistochemical expression of MGMT protein and to evaluate the possible prognostic significance of these biomarkers. Our results confirm that methylation of the MGMT gene and loss of MGMT protein are frequent events in these lymphomas (54 % of our cases) and suggest that they are gender and age related. MGMT methylation showed high correlation with loss of protein expression (concordance correlation coefficient = -0.49; Fisher exact test: p < 0.01), different from what has been observed in other brain tumors. In the subgroup of ten patients who received high dose chemotherapy, the presence of methylated MGMT promoter (n = 4), seems to be associated with a prolonged overall survival (>60 months in three of four patients). The prognostic significance of these molecular markers in PCNSL needs to be further studied in groups of patients treated in a homogeneous way.
Assuntos
Neoplasias do Sistema Nervoso Central/metabolismo , Linfoma/metabolismo , O(6)-Metilguanina-DNA Metiltransferase/biossíntese , O(6)-Metilguanina-DNA Metiltransferase/genética , Regiões Promotoras Genéticas , Adulto , Idoso , Biomarcadores Tumorais/metabolismo , Neoplasias do Sistema Nervoso Central/genética , Metilação de DNA , Dacarbazina/análogos & derivados , Dacarbazina/uso terapêutico , Feminino , Humanos , Imuno-Histoquímica , Linfoma/genética , Masculino , Pessoa de Meia-Idade , TemozolomidaRESUMO
Plagioscion squamosissimus is a species from the Amazon basin that was introduced into the Tietê River system. The present study aimed to analyse the feeding habits of this species in Bariri Reservoir and to verify the possible occurrence of ontogenetic changes in its diet composition. The samples were gathered in four periods of the year: February, June, September and November 2003. The fish were gathered with different fishing net meshes in three different reservoir portions. The alimentary items found in the stomachs were identified to the lowest possible taxonomic level and had abundance, occurrence frequency, volume and biomass determined. The Alimentary Index (IAi) was calculated for each alimentary item consumed by 'corvina' for each studied period. Comparisons among the diet of different size classes of P. squamosissimus were done using the similarity coefficient of Jaccard and the Cluster Analysis (UPGMA). The Friedman proof was performed to verify if there is a significant ontogenetic variation in the species diet and changes in the consumption of different alimentary categories by P. squamosissimus among the sampled periods. P. squamosissimus presented a piscivorous feeding habit, although other items were also consumed. The biggest values of IAi were obtained for the alimentary item fish in the months of June (0.47) and November (0.39). The item Ephemeroptera (Campsurinae) was the most representative in February (0.30) and June (0.45). Despite the fact that P. squamosissimus consumed an ample spectrum of alimentary items, the ontogenetic changes were evident through the exploration of aquatic insects by the younger classes and by a diet mainly composed of fish in adult individuals. The alimentary plasticity of P. squamosissimus evidenced in this study might have contributed to the success of this species in Bariri Reservoir.
Assuntos
Comportamento Alimentar/fisiologia , Conteúdo Gastrointestinal , Perciformes/fisiologia , Animais , Brasil , Rios , Estações do AnoRESUMO
Plagioscion squamosissimus is a species from the Amazon basin that was introduced into the Tietê River system. The present study aimed to analyse the feeding habits of this species in Bariri Reservoir and to verify the possible occurrence of ontogenetic changes in its diet composition. The samples were gathered in four periods of the year: February, June, September and November 2003. The fish were gathered with different fishing net meshes in three different reservoir portions. The alimentary items found in the stomachs were identified to the lowest possible taxonomic level and had abundance, occurrence frequency, volume and biomass determined. The Alimentary Index (IAi) was calculated for each alimentary item consumed by "corvina" for each studied period. Comparisons among the diet of different size classes of P. squamosissimus were done using the similarity coefficient of Jaccard and the Cluster Analysis (UPGMA). The Friedman proof was performed to verify if there is a significant ontogenetic variation in the species diet and changes in the consumption of different alimentary categories by P. squamosissimus among the sampled periods. P. squamosissimus presented a piscivorous feeding habit, although other items were also consumed. The biggest values of IAi were obtained for the alimentary item fish in the months of June (0.47) and November (0.39). The item Ephemeroptera (Campsurinae) was the most representative in February (0.30) and June (0.45). Despite the fact that P. squamosissimus consumed an ample spectrum of alimentary items, the ontogenetic changes were evident through the exploration of aquatic insects by the younger classes and by a diet mainly composed of fish in adult individuals. The alimentary plasticity of P. squamosissimus evidenced in this study might have contributed to the success of this species in Bariri Reservoir.
Plagioscion squamosissimus é uma espécie da Bacia Amazônica que foi introduzida no sistema do Rio Tietê. O presente estudo teve como objetivo analisar o hábito alimentar da espécie no reservatório de Bariri e verificar possível ocorrência de mudanças ontogenéticas na composição da dieta. As amostragens foram realizadas em quatro períodos do ano: fevereiro, junho, setembro e novembro de 2003. Os peixes foram coletados com redes de diferentes malhagens em três porções do reservatório. Os itens alimentares encontrados nos estômagos foram identificados até o menor nível taxonômico possível e tiveram abundância, frequência de ocorrência, volume e biomassa determinados. O Índice de Importância Alimentar (IAi) foi calculado para cada item alimentar consumido pela corvina para cada período estudado. Comparações entre as dietas das diferentes classes de tamanho de P. squamosissimus foram feitas utilizando-se o coeficiente de similaridade de Jaccard e a Análise de Cluster. A Prova de Friedman foi realizada para verificar se há variação ontogenética significante na dieta da espécie e se existem mudanças no consumo das categorias alimentares nos períodos amostrados. P. squamosissimus apresentou um hábito alimentar piscívoro, embora outros itens alimentares também tenham sido consumidos. Os maiores valores do IAi foram obtidos para o item alimentar peixes nos meses de junho (0,47) e novembro (0,39). O item Ephemeroptera foi mais representativo em fevereiro (0,30) e junho (0,45). Apesar do fato de P. squamosissimus consumir um amplo espectro de itens alimentares, as mudanças ontogenéticas ficaram evidentes pela exploração de insetos aquáticos pelas classes mais jovens e por uma dieta principalmente composta por peixe em indivíduos adultos. A plasticidade alimentar de P. squamosissimus evidenciada neste estudo pode ter contribuído para o sucesso da espécie nesse reservatório.
Assuntos
Animais , Comportamento Alimentar/fisiologia , Conteúdo Gastrointestinal , Perciformes/fisiologia , Brasil , Rios , Estações do AnoRESUMO
Phenol-formaldehyde resol containing mimosa tannin extract was employed to produce plywood panels with two plies from Eucalyptus globulus veneers. The effect of processing conditions and tannin content on the gelation time of the adhesive in the glue line was evaluated by dynamic-mechanical analysis (DMA). These results were related with shear strength and wood failure of glue line in the final panels. Hazardous petrochemical phenol could be partially substituted in resols in industrial applications by addition of mimosa tannin extracts.
Assuntos
Adesivos , Eucalyptus , Taninos , Madeira/análise , Flavonoides , Formaldeído , Taninos Hidrolisáveis , Cinética , Fenol , Fenóis , Polifenóis , Cimentos de ResinaRESUMO
BACKGROUND AND OBJECTIVE: There are two types of heparin-induced thrombocytopenia (HIT). HIT I is characterized by a transitory, slight and asymptomatic reduction in platelet count, occurring in the first 1-2 days of therapy, that resolves spontaneously; in contrast, HIT II, which has an immunologic origin, is characterized by a significant thrombocytopenia generally after the fifth day of therapy that usually resolves in 5-15 days only after therapy withdrawal. HIT II is the most frequent and dangerous side-effect of heparin therapy; in fact, in spite of thrombocytopenia, it can be complicated by venous and arterial thrombosis. Therefore, the recognition of HIT II may be difficult due to the underlying thrombotic symptoms for which heparin is administered. The aim of this article is to review the most recent advances in the field and to give critical guidelines for the clinical diagnosis and treatment of HIT II. STATE OF THE ART: The prevalence of HIT II, as confirmed by laboratory tests, seems to be about 2% in patients receiving unfractionated heparin (UH), while it is much lower in those receiving low molecular weight heparin (LMWH). The immunologic etiology of HIT II is largely accepted. Platelet factor 4 (PF4) displaced from endothelial heparan sulphate or directly from the platelets, binds to the heparin molecule to form an immunogenic complex. The anti-heparin/ PF4 IgG immunocomplexes activate platelets and provoke an immunologic endothelial lesion with thrombocytopenia and/or thrombosis. The IgG anti-heparin/PF4 immunocomplex activates platelets mainly through binding with the FcgRIIa (CD32) receptor. The onset of thrombocytopenia is independent of the dosage, schedule and route of administration of heparin. Orthopedic and cardiovascular surgery patients receiving post-surgical prophylaxis or treatment for deep venous thrombosis are at higher risk of HIT II. Besides thrombocytopenia, cutaneous allergic manifestations and skin necrosis may be present. Hemorrhagic events are not frequent, while the major clinical complications in 30% of patients are both arterial and venous thromboses which carry a 20% mortality. The diagnosis of HIT II should be formulated on the basis of clinical criteria and in vitro demonstration of heparin-dependent antibodies. Functional tests, such as platelet aggregation and (14)C-serotonin release assay and immunologic tests, such as the search for anti-PF4/heparin complex antibodies by an ELISA method are available. If HITT II is probable, heparin must be immediately suspended and an alternative anticoagulant therapy should be initiated before resolution of thrombocytopenia and the following treatment with a vitamin K antagonist. The general opinion is to administer low molecular weight heparin (in the absence of in vitro cross-reactivity with the antibodies), heparinoids such as Orgaran or direct thrombin inhibitors such as hirudin. PERSPECTIVES: Further studies are required to elucidate the pathogenesis of HIT II and especially to discover the clinical and immunologic factors that induce the occurrence of thrombotic complications. The best therapeutic strategy remains to be confirmed in larger clinical trials.
Assuntos
Heparina/efeitos adversos , Trombocitopenia/induzido quimicamente , Heparina/imunologia , Humanos , Incidência , Ativação Plaquetária/imunologia , Guias de Prática Clínica como Assunto , Trombocitopenia/epidemiologia , Trombocitopenia/imunologiaRESUMO
PURPOSE: We investigated the usefulness of a mechanical stress device to increase widening of the articular rima in CT studies of the meniscus on forced varus and valgus. MATERIAL AND METHODS: September 1997 to October 1998, we examined 284 patients with symptoms and clinical signs of meniscal injury. CT was performed during forced varus and valgus, depending on the site of the suspected damage, in 70 of 284 patients. We used an FOV of 18 cm, with a potential difference of 140 kVp and power of 170 mA. The reconstruction matrix was 512 x 512 and acquisition time was 3 s. A set of 8-10 partially overlapping scans were acquired craniocaudally, with slice thickness of 1.5 mm and gap of 1 mm. The mechanical strainer was locked in the correct position and a second set of 4-5 images acquired at the meniscus. Then the patients were submitted to arthroscopy to check the radiological findings. RESULTS: CT performed in forced varus and valgus had 96.8% specificity, 97.3% sensitivity and 97.1% diagnostic accuracy. Sensitivity was 100%, specificity 96% and diagnostic accuracy 98% in the medial meniscus, while we had 88.9%, 100% and 94.7% respectively in the external meniscus. CONCLUSIONS: CT with a mechanical stress device was extremely useful in defining the meniscal loose edge. It also showed the exact shape and complexity of meniscal injury, even in the cases with narrow articular rima or those where conventional CT had performed poorly.
Assuntos
Meniscos Tibiais/diagnóstico por imagem , Tomografia Computadorizada por Raios X/instrumentação , Adolescente , Adulto , Idoso , Desenho de Equipamento , Reações Falso-Negativas , Reações Falso-Positivas , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeAssuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Síndrome Antifosfolipídica/complicações , Síndrome Antifosfolipídica/imunologia , Linfoma de Células B/complicações , Linfoma de Células B/tratamento farmacológico , Adulto , Anticorpos Antinucleares/imunologia , Bleomicina/uso terapêutico , Ciclofosfamida/uso terapêutico , Doxorrubicina/uso terapêutico , Feminino , Humanos , Terapia de Imunossupressão , Leucovorina/uso terapêutico , Linfoma de Células B/imunologia , Metotrexato/uso terapêutico , Prednisona/uso terapêutico , Vincristina/uso terapêuticoRESUMO
To document the ultrastructural distribution of lens capsule proteoglycans, rabbit lens capsules were fixed and stained overnight in 50 mM sodium acetate, pH 5.6, containing 2.5% glutaraldehyde, 0.2% Cuprolinic Blue and 0.2 M MgCl2. They were rinsed, stained with 1% aqueous sodium tungstate, embedded in Epon, sectioned (60 nm), and examined with an electron microscope at 60 kV. Proteoglycan-Cuprolinic Blue complexes mainly appeared as networks of small electron-dense filaments throughout the posterior and anterior capsules. The posterior capsule was a single layer with a network of small proteoglycan filaments gradually decreasing in size from the humoral side (90 x 10 nm) to the lenticular side (30 x 8 nm). The humoral side of the anterior capsule had a thin lamina (400 nm) containing large (180 x 40 nm), very electron-dense proteoglycan-Cuprolinic Blue complexes plus small proteoglycans. Below this lamina, the complexes were only seen as filaments slightly smaller than those in the corresponding area of the posterior capsule. Cuprolinic Blue binding of the anterior and posterior lens capsules revealed differences in the size and distribution of their sulphated proteoglycans which do not correspond to the patterns of their immunoreactivity with anti-heparan sulphate proteoglycan. The humoral lamina in the anterior capsules, with large proteoglycan structures, might be a distinct structural and functional compartment.
Assuntos
Cápsula do Cristalino/química , Cápsula do Cristalino/ultraestrutura , Proteoglicanas/metabolismo , Animais , Membrana Basal/química , Membrana Basal/ultraestrutura , Corantes , Heparina/análogos & derivados , Heparina/metabolismo , Imuno-Histoquímica , Indóis , Microscopia Eletrônica , Compostos Organometálicos , Coelhos , Cloreto de TolônioRESUMO
BACKGROUND: There is no consensus on the efficacy of the antithrombotic drugs available for patients with intermittent claudication. METHODS: A Medline and manual search was used to identify relevant publications. Uncontrolled or retrospective studies, double reports or trials without clinical outcomes were excluded. Included studies were graded as level 1 (randomised and double- or assessor-blind), level 2 (open randomised), or level 3 (non-randomised comparative). Mortality, cerebro- or cardiovascular events, amputations, arterial occlusions or number of revascularization procedures performed in the lower limbs, pain-free and total walking distance, ankle brachial index and calf blood flow, were the main outcomes considered. When feasible, end of treatment results, either continuous or binary, were combined with appropriate statistical methods. RESULTS: Mortality was significantly decreased by ticlopidine compared to placebo (common odds ratio 0.68, 95% C.I., 0.49 - 0.95); clopidogrel decreased vascular events in comparison to aspirin (odds ratio 0.76, 95% C.I., 0.63 - 0.92) in level 1 studies. Arterial occlusions and the number of revascularization procedures performed were statistically significantly decreased by aspirin and ticlopidine, respectively. A small but statistically significant improvement in pain-free walking distance was determined by picotamide, indobufen, low molecular weight heparins, sulodexide and defibrotide, in small studies. CONCLUSIONS: Clopidogrel and ticlopidine do reduce clinically important events in patients with intermittent claudication and could be added to the primary medical treatment of these patients. The use of aspirin in these patients cannot be based on direct evidence, but only on analogy with coronary and cerebral atherosclerosis, where it has documented efficacy. Other antithrombotic drugs were not properly evaluated in patients with intermittent claudication.
Assuntos
Fibrinolíticos/uso terapêutico , Claudicação Intermitente/tratamento farmacológico , Humanos , Claudicação Intermitente/mortalidade , Claudicação Intermitente/fisiopatologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do TratamentoRESUMO
BACKGROUND AND OBJECTIVE: Approximately 15% of patients with cancer will experience a thrombotic episode at some time. Some patients are at particularly high risk depending on the histology of the malignant disease. The aim of the study was to determine the actual prevalence of thrombotic episodes in oncohematologic patients. DESIGN AND METHODS: We conducted a retrospective cohort analysis on a total of 515 patients that were admitted to the out-patients clinic (Institute of Medical Semeiotics) from January 1, 1986 to January 31, 1996. Two main groups were selected for this study: 133 patients suffering from a myeloproliferative disorder and 382 patients affected by a lymphoproliferative disorder. Follow-up lasted a median of 33 months in both groups (range 3-144 months). The difference between the observed events for each group was estimated by the odds ratio and chi square. Age and sex distribution were estimated by the Mann-Whitney test. Distribution of overall survival was estimated by the Kaplan-Meier method and compared between groups (DVT patients and non DVT patients) by the log-rank test. RESULTS: Twenty-three patients experienced a venous thrombotic disorder. The prevalence of deep vein thrombosis (DVT) in myeloproliferative and lymphoproliferative disorders was 8.27% (n = 11) and 3.14% (n = 12) respectively (odds ratio = 0.36; 95% CI = 0.14-0.90; chi-square = 4.94 p = 0.028). DVT was apparently idiopathic in 17 cases. In 4 patients another cancer was present; in the remaining 2 patients the thrombotic episode was associated with other predisposing factors. Although 7 of the 23 patients with DVT died, we cannot find any difference in the overall survival compared to oncohematologic patients who did not experience DVT. INTERPRETATION AND CONCLUSIONS: The prevalence of symptomatic DVT in the oncohematological patients is lower than reported for solid tumor. Patients affected by myeloproliferative disease have a higher risk of developing thrombosis. DVT if well-treated does not influence the survival of oncohematological patients.
Assuntos
Transtornos Linfoproliferativos/complicações , Transtornos Mieloproliferativos/complicações , Tromboflebite/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Tromboflebite/etiologiaRESUMO
We describe a case of thrombotic thrombocytopenic purpura (TTP) resistant to conventional therapy with fresh-frozen plasma (FFP)-plasma exchange (PEX) as well as to steroids, immunoglobulins, vincristine, dipyridamole, dextran and iloprost, achieving complete remission with cryosupernatant-plasma exchange. Our case shows the effectiveness of cryosupernatant PEX, when FFP-PEX and alternative therapies have failed.
Assuntos
Criopreservação , Troca Plasmática , Plasma , Púrpura Trombocitopênica/terapia , Adulto , Feminino , Humanos , Púrpura Trombocitopênica/fisiopatologiaRESUMO
Breast involvement by non-Hodgkin lymphoma is uncommon. Differences between primary and secondary breast lymphoma have been well-defined. However, histopathological features, therapeutic approach and outcome are still debated. We report the clinical and pathological features of 5 cases of malignant lymphoma primarily involving the breast. The literature is extensively reviewed paying particular attention to pathological features, therapeutic approach and survival analysis. All patients were women; the median age was 63.2 yr. The clinical course was indistinguishable from that of breast carcinoma. High-grade lymphoma was found in 4 cases; T cell lineage antigens were expressed in one case. All patients were in stage I or II. Treatment consisted of chemotherapy and/or radiotherapy. The follow-up period ranged from 20 to 54 months (mean, 33.2). All patients are still in complete clinical remission. Analysis of the literature showed that about 80% of cases are high grade lymphoma. In this group, stage I at presentation statistically gives the best survival rate; surgery does not appear to have a role in high-grade lymphoma treatment.
Assuntos
Neoplasias da Mama/diagnóstico , Linfoma não Hodgkin/diagnóstico , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/mortalidade , Intervalo Livre de Doença , Feminino , Humanos , Linfoma não Hodgkin/tratamento farmacológico , Linfoma não Hodgkin/mortalidade , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Taxa de SobrevidaRESUMO
The therapeutic approach to hairy cell leukemia (HCL) is in some instances still debated. A variant form of HCL (HCL-V) characterized by high white cell count, splenomegaly, hypercellular and aspirable bone marrow has been described; differential diagnosis often arises with some other B-cell disorders which also show circulating hairy or villous lymphocytes. Conventional treatment for HCL is often less effective in HCL-V. In this report we describe a case with features consistent with HCL-variant treated with splenic radiotherapy. We not only obtained an hematological response but also the near total disappearance of bone marrow infiltration, compatible with a clinical complete remission. Clinical and biological implications of this phenomenon are discussed on the basis of this unexpected therapeutic result, obtained with splenic radiotherapy alone.
Assuntos
Leucemia de Células Pilosas/radioterapia , Baço/efeitos da radiação , Idoso , Humanos , Masculino , Indução de RemissãoRESUMO
We describe a case of idiopathic myelofibrosis with total neutrophil myeloperoxidase deficiency. The combination of this enzymatic defect with myelofibrotic changes in the nuclear shape of neutrophils confers a peculiar appearance on leukograms produced by a Technicon H*1. The clinical course of the disease was shortened by recurrent infections that may be ascribed, at least in part, to reduced leukocyte microbicidal ability.
Assuntos
Neutrófilos/enzimologia , Peroxidase/deficiência , Mielofibrose Primária/enzimologia , Medula Óssea/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Neutrófilos/patologia , Mielofibrose Primária/sangue , Mielofibrose Primária/patologia , Mielofibrose Primária/fisiopatologiaRESUMO
Adverse reactions to interferon-alpha (IFN-alpha) therapy include flu-like syndrome, bone marrow suppression, neurotoxic effects, and autoimmunity. A slight increase in triglyceride levels has been described less frequently during IFN-alpha administration. The incidence of IFN-alpha-induced hypertriglyceridemia seems variable, and there are no clear data on how to treat it. We report the effect of long-term (more than 12 months) IFN-alpha treatment on triglyceride levels in 43 patients suffering from hairy cell leukemia (18), multiple myeloma (10), chronic myelogenous leukemia (6), cryoglobulinemia (5), non-Hodgkin's lymphoma (3), and Sezary syndrome (1). Hypertriglyceridemia was found in 6 patients (15%). In 3 patients, gemfibrozil restored normal triglyceride values. This study suggests that hypertriglyceridemia is a minor side effect of long-term IFN-alpha therapy and that gemfibrozil might be considered the treatment of choice.