Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 94
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
J Environ Manage ; 354: 120293, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38387345

RESUMO

The recurrence and severity of wildfire is on the rise due to factors like global warming and human activities. Mediterranean regions are prone to significant wildfire events, which cause extensive damage to ecosystems and soil properties. This study focuses on the municipality of Allande in south-western Asturias (Spain), a region highly affected by recurrent wildfires. In this regard, we sought to examine how the recurrence of such fires influences soil organic carbon fractionation and other soil parameters, such as nitrogen fractionation, pH, and cation exchange capacity. The study involved six sampling plots with between varying fire recurrence levels, from 0 to 4 events between 2005 and 2022. The results revealed some significant effects of wildfires recurrence on soil texture, inorganic elemental composition and CEC, but not on pH and CE. In soil affected by recurrent fires, labile carbon fractions (cold-water extractable & hot-water extractable), and fulvic acid concentrations decreased by up to 36%, 5%, and 45%, respectively in comparison with undisturbed soil. In contrast, humic acid concentration remained stable or increased in soils damaged by fire. Additionally, nitrogen species in soil were observed to decrease significantly in high recurrence scenarios, especially nitrate. On the basis of our findings, we conclude that wildfires impact the distinct fractions of organic carbon and nitrogen in soils and that this effect is aggravated by increasing recurrence.


Assuntos
Incêndios , Incêndios Florestais , Humanos , Solo/química , Ecossistema , Florestas , Carbono/química , Água , Nitrogênio/análise
3.
Actas Dermosifiliogr ; 106(9): 716-24, 2015 Nov.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-26277040

RESUMO

Although hidradenitis suppurativa is a common and serious skin condition, its treatment is not well established. It is now accepted that the moderate and severe forms of the disease are associated with marked systemic inflammation. The goal of treatment in hidradenitis suppurative is therefore to achieve systemic control of inflammation. In some cases, surgery may also be necessary to reduce the severity of the manifestations of cutaneous inflammation. Recent advances in our understanding of hidradenitis suppurativa have been accompanied by the emergence of novel approaches to its treatment, including the use of certain biologic drugs. Several clinical trials have been undertaken to test the effects of biologics (mainly adalimumab) in this setting. In this review, we analyze the different treatments available for hidradenitis suppurativa.


Assuntos
Hidradenite Supurativa/tratamento farmacológico , Inibidores de 5-alfa Redutase/uso terapêutico , Adalimumab/uso terapêutico , Corticosteroides/uso terapêutico , Algoritmos , Antibacterianos/uso terapêutico , Ensaios Clínicos como Assunto , Fístula Cutânea/etiologia , Fístula Cutânea/cirurgia , Dapsona/uso terapêutico , Hidradenite Supurativa/complicações , Hidradenite Supurativa/cirurgia , Humanos , Imunossupressores/uso terapêutico , Infliximab/uso terapêutico , Proteína Antagonista do Receptor de Interleucina 1/uso terapêutico , Retinoides/uso terapêutico
4.
Actas Dermosifiliogr ; 106(9): 703-15, 2015 Nov.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-26254550

RESUMO

Hidradenitis suppurativa is a chronic inflammatory disorder that has attracted increasing attention in recent years due to underestimations of prevalence and the considerable impact of the condition on interpersonal relationships, physical appearance, self-esteem, and body image. Although hidradenitis suppurative has a significant psychological impact on patients and can even cause physical limitations when thick scarring results in limb mobility limitation, until very recently little evidence was available relating to its epidemiology, etiology, or pathogenesis. In this review, we highlight the latest advances in our understanding of the epidemiological and clinical aspects of hidradenitis suppurativa. We will also look at the different classification systems for hidradenitis suppurativa and discuss the emergence of skin ultrasound as a promising technique for monitoring the course of this chronic inflammatory disease.


Assuntos
Hidradenite Supurativa , Abscesso/etiologia , Glândulas Apócrinas/patologia , Comorbidade , Fístula Cutânea/etiologia , Citocinas/fisiologia , Suscetibilidade a Doenças , Feminino , Hidradenite Supurativa/complicações , Hidradenite Supurativa/diagnóstico por imagem , Hidradenite Supurativa/epidemiologia , Hidradenite Supurativa/patologia , Humanos , Masculino , Microbiota , Obesidade/complicações , Prevalência , Fatores de Risco , Índice de Gravidade de Doença , Fumar/efeitos adversos , Ultrassonografia
5.
Clin Endocrinol (Oxf) ; 80(2): 261-9, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23746264

RESUMO

OBJECTIVE: Twenty-four-hour urinary free cortisol (UFC) sampling is commonly used to evaluate Cushing's syndrome. Because there are few data on UFC variability in patients with active Cushing's disease, we analysed baseline UFC in a large patient cohort with moderate-to-severe Cushing's disease and assessed whether variability correlates with hypercortisolism severity. These data will help clinicians establish the minimum number of UFC samples required to obtain reliable data. DESIGN: Observational study (enrolment phase of Phase III study). METHODS: Patients (n = 152) with persistent/recurrent or de novo Cushing's disease and mean UFC (mUFC) ≥1·5×ULN (normal: 30-145 nmol/24 h) were included. Mean UFC level was calculated from four 24-h urine samples collected over 2 weeks. RESULTS: Over 600 24-h UFC samples were analysed. The mUFC levels of samples 1 and 2 and samples 3 and 4 were 1000 nmol/24 h (SD 1872) and 940 nmol/24 h (SD 2148), respectively; intrapatient coefficient of variation (CV) was 38% for mUFC. The intrapatient CV using all four samples was 52% (95% CI: 48-56). The intrapatient CV was 51% (95% CI: 44-58) for samples 1 and 2, 49% (95% CI: 43-56) for samples 3 and 4 and 54% (95% CI: 49-59) for samples 1, 2 and 3. Variability in mUFC increased as UFC levels increased. There were no correlations between UFC and clinical features of hypercortisolism. CONCLUSIONS: There is intrapatient variability of approximately 50% in 24-h UFC measurements, which is relevant to targets set to estimate any treatment effect. Analysing more than two 24-h collection periods in individual patients does not result in a relevant decrease in variability. Interestingly, UFC levels did not correlate with hypercortisolism severity.


Assuntos
Hidrocortisona/urina , Hipersecreção Hipofisária de ACTH/tratamento farmacológico , Hipersecreção Hipofisária de ACTH/urina , Somatostatina/análogos & derivados , Adulto , Idoso , Síndrome de Cushing/patologia , Síndrome de Cushing/urina , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Hipersecreção Hipofisária de ACTH/patologia , Recidiva , Valores de Referência , Índice de Gravidade de Doença , Somatostatina/uso terapêutico , Fatores de Tempo , Resultado do Tratamento
6.
Environ Pollut ; 333: 122066, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37343919

RESUMO

The combination of a low-density geochemical survey, multispectral data obtained with Unmanned Aerial Vehicle-Remote Sensing (UAV-RS), and a machine learning technique was tested in the search for a statistically robust prediction of contaminant distribution in soil and vegetation, for zones with a highly variable pollutant load. To this end, a novel methodology was devised by means of a limited geochemical study of topsoil and vegetation combined with multispectral data obtained by UAV-RS. The methodology was verified in an area affected by Hg and As contamination that typifies abandoned mining-metallurgy sites in recent decades. A broad selection of spectral indices were calculated to evaluate soil-plant system response, and four machine learning techniques (Multiple Linear Regression, Random Forest, Generalized Boosted Models, and Multivariate Adaptive Regression Spline) were tested to obtain robust statistical models. Random Forest (RF) provided the best non-biased models for As and Hg concentration in soil and vegetation, with R2 and rRMSE (%) ranging from 0.501 to 0.630 and from 180.72 to 46.31, respectively, and with acceptable values for RPD and RPIQ statistics. The prediction and mapping of contaminant content and distribution in the study area were well enough adjusted to the geochemical data and revealed superior accuracy for As than Hg, and for vegetation than topsoil. The results were more precise than those obtained in comparable studies that applied satellite or spectrometry data. In conclusion, the methodology presented emerges as a powerful tool for studies addressing soil and vegetation pollution and an alternative approach to classical geochemical studies, which are time-consuming and expensive.

7.
Biophys J ; 101(1): 43-52, 2011 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-21723813

RESUMO

We perform a detailed investigation of the force × deformation curve in tether extraction from 3T3 cells by optical tweezers. Contrary to conventional wisdom about tethers extracted from cells, we find that actin filaments are present within them, so that a revised theory of tether pulling from cells is called for. We also measure steady and maximum tether force values significantly higher than previously published ones for 3T3 cells. Possible explanations for these differences are investigated. Further experimental support of the theory of force barriers for membrane tube extension is obtained. The potential of studies on tether pulling force × deformation for retrieving information on membrane-cytoskeleton interaction is emphasized.


Assuntos
Citoesqueleto/metabolismo , Fibroblastos/citologia , Células 3T3 , Actinas/metabolismo , Animais , Fenômenos Biomecânicos , Adesão Celular , Fibroblastos/metabolismo , Fibroblastos/ultraestrutura , Camundongos , Microesferas
8.
Nutr Cancer ; 63(1): 39-45, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21128180

RESUMO

In colon cancer, disturbances have been detected in genes coding for proteins involved in cellular proliferation, such as K-ras, ß-catenin, extracellular signal-regulated kinases (ERKs), and the protein kinase B (PKB). Although carotenoids such as lutein have an important role to prevent and treat some types of cancer, there are very few studies about the effect of lutein against colon cancer and its activity at the molecular level. Therefore, the aim of this study was to evaluate the chemoprotective activity of lutein against colon cancer induced by dimethylhydrazine (DMH). The results showed a significant increase in protein expression for K-ras and ß-catenin in tumors of DMH-treated rats. Simultaneously, we detected changes in the phosphorylation state of ERK1/2 and PKB in DMH-treated animals. Lutein given in the diet (0.002%), before (prevention) and after (treatment) DMH administration, diminished the number of tumors by 55% and 32%, respectively. Moreover, lutein significantly decreased in tumors the expression of K-ras (25%) and ß-catenin (28%) and the amount of pPKB (32%), during the prevention, and 39%, 26%, and 26% during the treatment stage, respectively. This study demonstrates the chemoprotective effect of lutein against colon cancer by modulating the proliferative activity of K-ras, PKB, and ß-catenin proteins.


Assuntos
Neoplasias do Colo/prevenção & controle , Suplementos Nutricionais , Luteína/administração & dosagem , Proteínas Proto-Oncogênicas c-akt/fisiologia , Proteínas Proto-Oncogênicas p21(ras)/fisiologia , beta Catenina/fisiologia , 1,2-Dimetilidrazina , Animais , Neoplasias do Colo/induzido quimicamente , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Masculino , Proteínas Proto-Oncogênicas c-akt/análise , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas p21(ras)/análise , Proteínas Proto-Oncogênicas p21(ras)/genética , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , beta Catenina/análise , beta Catenina/genética
9.
Ceylon Med J ; 56(1): 22-8, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21542430

RESUMO

OBJECTIVE: To examine the validity of selected entry level characteristics in relation to the GCE A/L examination as independent predictors of performance of students in medical school. METHODS: A retrospective, analytical study was done at the Faculty of Medicine, University of Kelaniya. Student characteristics at entry were described by sex, the average z-score, General English grade and attempt at GCE A/L examination, and average mark obtained at the English placement test on registration to medical school. Average marks at three summative examinations were used as indicators of performance in medical school. Multivariate analysis using multiple linear regression was carried out using these three outcome measures in relation to four entry point variables as predictors of performance in medical school. Causal path diagrams were constructed using standardised regression coefficients for the whole group and for male and female students separately. RESULTS: The A/L z-score, A/L attempt and English placement test marks were all significant predictors of outcome at the First Examination. Of the variables relating to the A/L examination, the attempt had a much higher path coefficient with performance at the First Examination than the A/L z-score, as did the English marks. Separate path analyses for male and female students showed that while the significance of the relationships remained the same, the magnitude of the correlation was different. CONCLUSIONS: Students who gain admission on their 3rd attempt at the AL examination fare much worse than those admitted to medical school on their 1st attempt. Differences between sexes in examination performance are probably linked to both A/L attempt and English language proficiency.


Assuntos
Testes de Aptidão , Multilinguismo , Critérios de Admissão Escolar/estatística & dados numéricos , Testes de Aptidão/normas , Testes de Aptidão/estatística & dados numéricos , Comunicação , Educação de Graduação em Medicina/organização & administração , Educação de Graduação em Medicina/estatística & dados numéricos , Feminino , Humanos , Modelos Lineares , Masculino , Reprodutibilidade dos Testes , Faculdades de Medicina/normas , Faculdades de Medicina/estatística & dados numéricos , Fatores Sexuais , Estudantes de Medicina/psicologia , Análise e Desempenho de Tarefas
10.
Clin Transl Oncol ; 23(10): 2109-2119, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33881707

RESUMO

PURPOSE: Leptomeningeal disease (LMD) is a rare but deadly complication of cancer in which the disease spreads to the cerebrospinal fluid and seeds the meninges of the central nervous system (CNS). Craniospinal irradiation (CSI) involves treatment of the entire CNS subarachnoid space and is occasionally used as a last-resort palliative therapy for LMD. METHODS: This review examined literature describing the role of CSI for LMD from solid and hematologic malignancies in adults. A search for studies published until September 1, 2020 was conducted using PubMed database. RESULTS: A total of 262 unique articles were identified. Thirteen studies were included for analysis in which a total of 275 patients were treated with CSI for LMD. Median age at time of irradiation was 43 years, and most patients had KPS score of 70 and higher. The most common cancers resulting in LMD were acute lymphocytic leukemia, breast cancer, and acute myelogenous leukemia. Median CSI dose was 30 Gy and 18% of patients were treated with proton radiation. 52% of patients had stable-to-improved neurologic symptoms. Median overall survival for the entire cohort was 5.3 months. Patients treated with marrow-sparing proton radiation had median OS of 8 months. The most common treatment toxicities were hematologic and gastrointestinal events. CONCLUSIONS: Despite advances in systemic and radiation therapies, LMD remains a devastating end-stage complication of some malignancies. Treatment-related toxicities can be a significant barrier to CSI delivery. In select patients with LMD, marrow-sparing proton CSI may provide safer palliation of symptoms and prolong survival.


Assuntos
Radiação Cranioespinal , Neoplasias Meníngeas/radioterapia , Adulto , Neoplasias da Mama/patologia , Feminino , Humanos , Avaliação de Estado de Karnofsky/estatística & dados numéricos , Leucemia Mieloide Aguda/patologia , Masculino , Neoplasias Meníngeas/mortalidade , Neoplasias Meníngeas/secundário , Pessoa de Meia-Idade , Tratamentos com Preservação do Órgão/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Dosagem Radioterapêutica
11.
Int J Gynaecol Obstet ; 153(3): 483-488, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33119891

RESUMO

OBJECTIVE: To evaluate whether the concentration of serum lactate during the diagnosis of postpartum hemorrhage (bleeding ≥500 mL during labor or ≥1000 mL during cesarean delivery) predicts severe hemorrhage (SPPH; blood loss ≥1500 mL at end of labor or in the following 24 h). METHODS: A prospective cohort pilot study was conducted of women with a vaginal or cesarean delivery from February 2018 to March 2019 who presented with bleeding ≥500 mL measured by the gravimetric method in a reference hospital in San Luis Potosi, Mexico. Venous blood samples were taken for analysis of serum lactate. A receiver operating characteristic curve determined the serum lactate threshold value for SPPH and χ2 test assessed the difference in serum lactate elevation between SPPH and non-SPPH groups. Lastly, the prognostic capacity between the thresholds was compared. RESULTS: SPPH developed in 43.33% of the 30 women in the study group. The best prognostic threshold was 2.68 mmol/L of serum lactate (odds ratio [OR] 17.88, 95% confidence interval [CI] 2.7-16.8, P < 0.001); sensitivity was 0.85 (95% CI 0.55-0.98); specificity was 0.76 (95% CI 0.50-0.93). CONCLUSION: Serum lactate may be a useful prognostic marker for SPPH, more studies are needed to validate these findings.


Assuntos
Cesárea , Parto Obstétrico , Ácido Láctico/sangue , Hemorragia Pós-Parto/sangue , Adulto , Biomarcadores/sangue , Estudos de Coortes , Feminino , Humanos , Projetos Piloto , Gravidez , Prognóstico , Sensibilidade e Especificidade , Adulto Jovem
12.
Tech Coloproctol ; 14(4): 317-21, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20949301

RESUMO

BACKGROUND: Fistula in ano is a rather common condition, but the disease process is not yet fully understood. The aim of our study was to determine how the distribution of anal glands contributes to the variable occurrence of fistula-in-ano in the perineum. METHODS: we conducted a blinded two-phase prospective study. In the first phase, the perineum of the patients with primary fistulae was anatomically divided into right upper and lower and left upper and lower quadrants in the lithotomy position. The fistulae were classified according to what quadrant the external and internal openings and the tract pathway were in. In the second phase, using 10 human cadaver specimens, full thickness tissue samples were taken from each quadrant of the anus. Samples were histologically evaluated for the volume fractions of the anal glands in each quadrant. RESULTS: The new classification system we propose revealed that the largest number of fistulae 43% (17/39) were in the right lower quadrant, and 22% (9/39), 12% (5/39) and 8% (3/39) were in the left lower, right upper and left upper quadrants, respectively. It was also observed that 14% (5/39) of fistulae were in more than one quadrant. The volume fractions of each quadrant showed that the largest volume fraction of the anal glands was in the right lower quadrant (right lower quadrant: 0.64, left lower quadrant: 0.35, right upper quadrant: 0.26 and left upper quadrant: 0.22, P = 0.001). CONCLUSIONS: To the best of our knowledge, this is the first study that has objectively shown that the distribution of the anal glands is variable, and the highest density of anal glands is in the right lower quadrant of the anus. This variable distribution may be associated with the variable occurrence in fistula in ano.


Assuntos
Canal Anal/anatomia & histologia , Fístula Retal/classificação , Fístula Retal/patologia , Adulto , Idoso , Cadáver , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Períneo , Estudos Prospectivos , Método Simples-Cego , Adulto Jovem
13.
Vet Q ; 40(1): 205-214, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32813983

RESUMO

BACKGROUND: Marine invertebrates are provided as a first feed for marine fish larvae because of their strict nutritional requirements, despite also being a potential source of infectious agents. AIM: To assess horizontal transmission of a nervous necrosis virus reassortant strain (NNV) to sole larvae via Artemia and rotifers. MATERIALS AND METHODS: Rotifer (Brachionus plicatilis) and Artemia (Artemia salina) nauplii cultures were bath infected with a reassortant (RGNNV/SJNNV) NNV strain isolated from gilthead sea bream and viral internalisation was confirmed by IFA. Senegalese sole (Solea senegalensis) larvae were fed on infected Artemia and disease signs and mortality were recorded. In addition, NNV viability was checked in cultures of either unfed invertebrates or invertebrates fed on phytoplankton and in the supernatant of microalgae cultures. All samples were tested by RT-qPCR and inoculation in cell culture. RESULTS: Both rotifers and Artemia internalised NNV. Experimental transmission to sole larvae was achieved using infected Artemia and subsequently 60% mortality was recorded. At 24 h post-infection, orally infected individuals contained 9.34 × 104 copies of viral RNA, whereas the bath infection yielded 2.05 × 106 RNA copies larvae-1. Viral presence in both invertebrates was detected up to 8 days post infection but viral load decreased over time. Feeding with microalgae decreased viral detection even more and microalgae supernatants were demonstrated to significantly affect NNV viability. CONCLUSIONS: Our results demonstrate that both invertebrates can bioaccumulate NNV and that Senegalese sole larvae fed on infected Artemia might develop viral encephalopathy and retinopathy and high mortality.


Assuntos
Artemia/virologia , Doenças dos Peixes/virologia , Linguados/virologia , Vírus Reordenados/patogenicidade , Rotíferos/virologia , Viroses/veterinária , Animais , Doenças dos Peixes/mortalidade , Larva , Necrose/veterinária , Necrose/virologia , Vírus Reordenados/isolamento & purificação , Carga Viral , Viroses/transmissão
14.
Cancer Radiother ; 24(8): 834-841, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33191120

RESUMO

PURPOSE: Neoadjuvant chemoradiotherapy (nCRT) followed by surgery in patients with resectable esophageal or esophagogastric junctional (GEJ) (Siewert I) cancer is associated with long term overall survival benefits. Up to one third of all patients submitted to nCRT present pathological complete response (pCR). 18F-fluorodeoxyglucose positron emission tomography with CT (18F-FDG PET-CT) is an important tool for assessing treatment response. Purpose was to assess retrospectively the power of 18F-FDG PET-CT in predicting pCR to evaluate the feasibility of a "watch and wait" approach. PATIENTS AND METHODS: Retrospective analysis of a prospective database with esophageal or GEJ submitted to pre-operative chemoradiation. Pre and pos treatment 18F-FDG PET-CT were reviewed and classified using visual assessment and PERCIST criteria and the values of maximum standard uptake value were also recorded. Patients were classified as pCR or non-PCR. 18F-FDG PET-CT and pathological findings were compared against each other. RESULTS: Forty-three patients were included. The median age was 67 years and 90.7% were male. All patients underwent preoperative CRT and were evaluated with 18F-FDG PET-CT pre and post treatment. Transthoracic surgery was performed in all patients. Histological type was adenocarcinoma in 37% and squamous cell carcinoma in 58%. pCR was achieved in 56% of cases. Visual assessment of 18F-FDG PET-CT showed overall sensitivity 57.9%, specificity 62.5% and PERCIST criteria had 100% sensibility and 16.7% specificity. CONCLUSIONS: 18F-FDG PET-CT is not an ideal predictor of pCR but if we use the PERCIST criteria we will have a high sensitivity and negative predictive value, avoiding false negative scans.


Assuntos
Quimiorradioterapia Adjuvante/métodos , Neoplasias Esofágicas/terapia , Junção Esofagogástrica , Terapia Neoadjuvante/métodos , Adenocarcinoma/metabolismo , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Adenocarcinoma/terapia , Idoso , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/terapia , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/patologia , Feminino , Fluordesoxiglucose F18 , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Cuidados Pré-Operatórios , Compostos Radiofarmacêuticos , Estudos Retrospectivos , Sensibilidade e Especificidade , Resultado do Tratamento , Conduta Expectante
15.
Science ; 293(5539): 2444-6, 2001 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-11577234

RESUMO

Little is known about the cranial anatomy of the taxonomically diverse and geographically widespread titanosaurs, a paucity that has hindered inferences about the genealogical history and evolutionary development of the latest sauropod dinosaurs. Newly discovered fossil eggs containing embryonic remains from the Late Cretaceous of Argentina provide the first articulated skulls of titanosaur dinosaurs. The nearly complete fetal skulls shed light on the evolution of some of the most notable cranial features of sauropod dinosaurs, including the retraction of the external nares, the forward rotation of the braincase, and the abbreviation of the infraorbital region.


Assuntos
Evolução Biológica , Fósseis , Répteis/embriologia , Crânio/embriologia , Animais , Argentina , Embrião não Mamífero/anatomia & histologia , Nariz/anatomia & histologia , Nariz/embriologia , Crânio/anatomia & histologia
16.
J Struct Biol ; 162(2): 345-55, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18337120

RESUMO

The production of secondary metabolites in seaweed have been related to a capability to partition compounds into cellular specialized storage structures, like gland cells and the corps en cerise (CC) or cherry bodies. The possible mechanisms that bring these compounds to the thallus surface remain poorly understood. Therefore, the aim of this work is perform a characterization of the CC and determine the intra-cellular dynamics of halogenated compounds in Laurencia obtusa. The dynamics of CC and the mechanisms related to the intra-cellular transport of halogenated compounds were evaluated by using optical tweezers and time-lapse video microscopy. The CC were isolated and its elemental composition was characterized using X-ray microanalysis. The cellular distribution of halogenated compounds was also demonstrated by fluorescence microscopy. Three-dimensional reconstruction technique was used to provide a visualization of the structures that connect CC to cell periphery. As main findings, we confirmed that the halogenated compounds are mainly found in CC and also in vesicles distributed along the cytoplasm and within the chloroplasts. We demonstrated that CC is mechanically fixed to cell periphery by a stalk-like connection. A vesicle transport though membranous tubular connections was seen occurring from CC to cell wall region. We also demonstrated a process of cortical cell death event, resulting in degradation of CC. We suggested that the vesicle transportation along membranous tubular connections and cell death events are related to the mechanisms of halogenated compounds exudation to the thallus surface and consequently with defensive role against herbivores and fouling.


Assuntos
Transporte Biológico , Hidrocarbonetos Halogenados/metabolismo , Laurencia/metabolismo , Laurencia/fisiologia , Morte Celular , Microanálise por Sonda Eletrônica , Exocitose , Processamento de Imagem Assistida por Computador , Rodófitas
17.
Braz J Biol ; 68(1): 95-100, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18470382

RESUMO

The marine ecosystems of Todos os Santos Bay (TSB, The State of Bahia, Brazil) have been impacted by the presence on its coast of a large metropolitan area as well as of chemical and petrochemical activities. Despite its ecological importance, there is a lack of scientific information concerning metal contamination in TSB marine biota. Thus, we analyzed concentrations of metals in four species of marine benthic organisms (two seaweeds, Padina gymnospora and Sargassum sp. one seagrass, Halodule wrightii and one oyster, Crassostrea rhizophorae) in three sites from the TSB region that have been most affected by industrial activities. The concentrations of Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined by Atomic Absorption Spectrophometry. The obtained data indicates that cadmium and copper in seaweeds, oysters and seagrass, as well as Ni concentrations in oysters, were in range of contaminated coastal areas. Cadmium and copper are available to organisms through suspended particles, dissolved fraction of water column and bottom sediment interstitial water. As oysters and other mollusks are used as food sources by the local population, the metal levels found in oysters in TSB may constitute a health risk for this population. Our results suggest implanting a heavy metals biomonitoring program in the TSB marine ecosystems.


Assuntos
Monitoramento Ambiental/métodos , Eucariotos/química , Magnoliopsida/química , Metais Pesados/análise , Ostreidae/química , Poluentes Químicos da Água/análise , Animais , Brasil , Água do Mar/química , Espectrofotometria Atômica
18.
An Med Interna ; 25(2): 67-72, 2008 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-18432362

RESUMO

OBJECTIVE: VEIA study is an evolutional registry of acute poisonings (AP) attended in the Emergency Room of the Doce de Octubre Hospital in Madrid (Spain) in a whole year (1979,1985, 1990, 1994,1997 and 2000). We present the 2004 study and compare the results with the previous years. METHODS AND RESULTS: Methodology has been identical across VEIA study. Of 1508 AP, 610 are suicide attempts (IAVIS), 319 ethylic, (IAVE), and 218 by illicit drugs (IAVD). Of the 2,259 toxics involved, 48% are medications (50% benzodiacepines) alcohol 25% and illicit drugs 13%. CONCLUSIONS: There is an important increase (34%) of cases and the incidence surpasses all published in our country. There are no gender differences nor in the whole neither the Health Area Census, but there are differences in IAVIS, IAVE and IAVD. IAVIS increase in 35%. Benzodiacepines poisoning increases two-fold as well as antidepressive drugs do in women. In men also increase, but in a minor extent. Acetaminophen remains the same in 23%. NSAID's, adjuvants and myorelaxants increase in women as do also alcohol and other poisons that almost equal men's. There are 13 cases of IAVIS in patients with alimentary disorders. Among men, a quarter are illicit drug abusers. In IAVE, the group without alcoholism grows and the total decreases. Illicit drugs duplicate the number of the former year. Cocaine supposes already 2/3 of the cases, MDMA ascends to 22 cases and they appear new substances as glue, without doubt as an effect of immigration and ketamine. Finally 205 household accidents and 57 industrial injuries complete the series.


Assuntos
Intoxicação/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Espanha , População Urbana
19.
An Med Interna ; 25(6): 262-8, 2008 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-19295972

RESUMO

OBJECTIVE: VEIA study is an evolutional registry of acute poisonings (AP) attended in the Emergency Room of the Doce de Octubre Hospital in Madrid (Spain) in a whole year (1979, 1985, 1990, 1994,1997 and 2000). We present the 2004 study and compare the results with the previous years. METHODS AND RESULTS: Methodology has been identical across VEIA STUDY. Of 1508 AP, 610 are suicide attempts (IAVIS), 319 ethylic, (IAVE), and 218 by illicit drugs (IAVD). Of the 2,259 toxics involved, 48% are medications (50% benzodiacepines) alcohol 25% and illicit drugs 13%. CONCLUSIONS: There is an important increase (34%) of cases and the incidence surpasses all published in our country. There are no gender differences nor in the whole neither the Health Area Census, but there are differences in IAVIS, IAVE and IAVD. IAVIS increase in 35%. Benzodiacepines poisoning increases two-fold as well as antidepressive drugs do in women. In men also increase, but in a minor extent. Acetaminophen remains the same in 23%. NSAID's, adjuvants and myorelaxants increase in women as do also alcohol and other poisons that almost equal men's. There are 13 cases of IAVIS in patients with alimentary disorders. Among men, a quarter are illicit drug abusers. In IAVE, the group without alcoholism grows and the total decreases. Illicit drugs duplicate the number of the former year. Cocaine supposes already 2/3 of the cases, MDMA ascends to 22 cases and they appear new substances as glue, without doubt as an effect of immigration and ketamine. Finally 205 household accidents and 57 industrial injuries complete the series.


Assuntos
Intoxicação/epidemiologia , Vigilância da População , Sistema de Registros , Acidentes Domésticos , Acidentes de Trabalho , Acetaminofen/intoxicação , Doença Aguda , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Intoxicação Alcoólica/epidemiologia , Antidepressivos/intoxicação , Benzodiazepinas/intoxicação , Distribuição de Qui-Quadrado , Cocaína/intoxicação , Serviço Hospitalar de Emergência , Feminino , Humanos , Drogas Ilícitas/intoxicação , Incidência , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Espanha/epidemiologia , Tentativa de Suicídio/estatística & dados numéricos
20.
J Endocrinol Invest ; 30(4): 334-40, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17556872

RESUMO

GH secretagogues (GHS) have been used for the differential diagnosis of ACTH-dependent Cushing's syndrome (CS) since 1997 due to their ability to increase ACTH and cortisol levels in Cushing's disease. The aim of this study was to correlate ACTH response to GH-releasing peptide-6 (GHRP-6) in vivo with GH secretagogue receptor type 1a (GHSR-1a) mRNA expression in a patient with lung carcinoid tumor. The patient was a 26-yr-old male with diagnosis of ACTH-dependent CS. He presented negative responses to human CRH and desmopressin tests; yet, a significant increase in ACTH after the GHRP-6 test was observed. Sellar magnetic resonance imaging (MRI) showed slight posterior hypointensity, but bilateral petrosal sinus sampling did not show central gradient. Computed tomography (CT) and MRI of thorax/abdomen/cervical were negative and 111In-pentetreotide scintigraphy depicted abnormal uptake on the right lung. The patient was submitted to right thoracotomy for exeresis of lung nodule and hilar lymph node which were characterized as atypical lung carcinoid tumor and he presented clinical and laboratorial remission after surgery. GHSR-1a mRNA expression was studied with real-time quantitative PCR and tumor data were compared with fragments of normal lung and pituitary. There was a higher GHSR-1a expression in the lung carcinoid tumor as compared with normal tissues. The ACTH response to GHRP-6 in a patient with ectopic ACTH production by a lung carcinoid tumor was associated with GHSR-1a expression in the tumor tissue, suggesting an association between GHSR-1a mRNA overexpression and the in vivo response to GHS.


Assuntos
Síndrome de ACTH Ectópico/diagnóstico , Tumor Carcinoide/diagnóstico , Síndrome de Cushing/diagnóstico , Neoplasias Pulmonares/diagnóstico , Oligopeptídeos/farmacologia , Receptores Acoplados a Proteínas G/genética , Síndrome de ACTH Ectópico/complicações , Síndrome de ACTH Ectópico/genética , Adulto , Tumor Carcinoide/complicações , Tumor Carcinoide/genética , Síndrome de Cushing/etiologia , Síndrome de Cushing/genética , Diagnóstico Diferencial , Técnicas de Diagnóstico Endócrino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/genética , Masculino , Oligopeptídeos/genética , RNA Mensageiro/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Grelina
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA