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1.
Int J Mol Sci ; 23(3)2022 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-35162954

RESUMO

Mesothelin (MSLN) overexpression (OE) is a frequent finding in ovarian carcinomas and increases cell survival and tumor aggressiveness. Since cancer stem cells (CSCs) contribute to pathogenesis, chemoresistance and malignant behavior in ovarian cancer (OC), we hypothesized that MSLN expression could be creating a favorable environment that nurtures CSCs. In this study, we analyzed the expression of MSLN and CSC markers SOX2 and ALDH1 by immunohistochemistry (IHC) in different model systems: primary high-grade serous carcinomas (HGSCs) and OC cell lines, including cell lines that were genetically engineered for MSLN expression by either CRISPR-Cas9-mediated knockout (Δ) or lentivirus-mediated OE. Cell lines, wild type and genetically engineered, were evaluated in 2D and 3D culture conditions and xenografted in nude mice. We observed that MSLN was widely expressed in HGSC, and restricted expression was observed in OC cell lines. In contrast, SOX2 and ALDH1 expression was limited in all tissue and cell models. Most importantly, the expression of CSC markers was independent of MSLN expression, and manipulation of MSLN expression did not affect CSC markers. In conclusion, MSLN expression is not involved in driving the CSC phenotype.


Assuntos
Família Aldeído Desidrogenase 1/metabolismo , Cistadenocarcinoma Seroso/patologia , Mesotelina/metabolismo , Neoplasias Ovarianas/patologia , Retinal Desidrogenase/metabolismo , Fatores de Transcrição SOXB1/metabolismo , Animais , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Cistadenocarcinoma Seroso/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Camundongos , Células-Tronco Neoplásicas/metabolismo , Neoplasias Ovarianas/metabolismo , Estudos Retrospectivos , Ensaios Antitumorais Modelo de Xenoenxerto
2.
Stud Hist Philos Sci ; 95: 104-107, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36001922

RESUMO

In a recent paper on Hertz's Mechanics, Eisenthal claims that this mechanics is without mechanisms. He argues that the absence of mechanisms is a consequence of Hertz's philosophy of physics, presented in the introduction to this book. In the present paper, I will show that Hertz created four mechanisms. These mechanisms play a fundamental role in the deduction of the equations of motion. Some physicists used these mechanisms to create Hertzian mechanical models or to apply Hertz's mechanics to phenomena.


Assuntos
Física , Humanos , Masculino , Movimento (Física)
3.
Int J Mol Sci ; 19(7)2018 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-30011875

RESUMO

Optimal research results rely on the selection of cellular models capable of recapitulating the characteristics of primary tumours from which they originate. The expression of mucins (MUC16 and MUC1) and truncated O-glycans (Tn, STn and T) represents a characteristic footprint of serous ovarian carcinomas (SOCs). Therefore, selecting ovarian cancer (OVCA) cell lines that reflect this phenotype is crucial to explore the putative biological role of these biomarkers in the SOC setting. Here, we investigated a panel of OVCA cell lines commonly used as SOC models, and tested whether, when cultured in 2D and 3D conditions, these recapitulate the mucin and O-glycan expression profiles of SOCs. We further explored the role of truncating the O-glycosylation capacity in OVCAR3 cells through knockout of the COSMC chaperone, using in vitro and in vivo assays. We found that the majority of OVCA cell lines of serous origin do not share the mucin and truncated O-glycan footprint of SOCs, although 3D cultures showed a higher resemblance. We also found that genetic truncation of the O-glycosylation capacity of OVCAR3 cells did not enhance oncogenic features either in vitro or in vivo. This study underscores the importance of well-characterized cellular models to study specific features of ovarian cancer.


Assuntos
Antígeno Ca-125/metabolismo , Cistadenocarcinoma Seroso/metabolismo , Proteínas de Membrana/metabolismo , Mucina-1/metabolismo , Neoplasias Ovarianas/metabolismo , Polissacarídeos/metabolismo , Animais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Antígeno Ca-125/genética , Linhagem Celular Tumoral , Cistadenocarcinoma Seroso/genética , Cistadenocarcinoma Seroso/patologia , Feminino , Perfilação da Expressão Gênica , Glicosilação , Humanos , Proteínas de Membrana/genética , Camundongos Nus , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Mucina-1/genética , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Fenótipo , Transplante Heterólogo
4.
J Cell Biochem ; 118(8): 2064-2071, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-27886397

RESUMO

Adrenocortical carcinomas (ACC) are most frequently highly aggressive tumors. We assessed the telomerase reverse transcriptase (TERT) and N-cadherin role in the biology of ACC and their potential utility as molecular biomarkers, in different types of tumoral adrenocortical tissue. A total of 48 adrenal cortex samples (39 tumoral and 9 normal adrenal glands) were studied. TERT promoter mutations were searched by PCR and Sanger sequencing in two hotspots positions (-124 and -146). Also, telomerase and N-cadherin expression were evaluated by immunohistochemistry. TERT promoter mutations were not detected in any of the samples either malignant or benign. Telomerase nuclear expression was present in 26.6% of ACC and in 45.5% of non-functioning adenomas. It was absent in benign Cushing's lesions and in normal adrenal glands. Contrarily, N-cadherin was always expressed in the cellular membranes of benign adenomas or normal adrenals but no expression was detected in the majority of ACC. Nuclear telomerase and membrane N-cadherin expression were positively correlated in ACCs. We conclude that in ACC, the loss of N-cadherin is a frequent phenomenon while the existence of TERT promoter mutations is not and nuclear telomerase expression is present in only a minority of cases. Since the loss of N-cadherin expression was identified in both high and low proliferative ACC, this marker should be considered important for diagnostic application. Our study also suggests the existence of a TERT non-canonical function in cell adhesion. J. Cell. Biochem. 118: 2064-2071, 2017. © 2017 Wiley Periodicals, Inc.


Assuntos
Neoplasias do Córtex Suprarrenal/genética , Carcinoma Adrenocortical/genética , Antígenos CD/genética , Caderinas/genética , Regulação Neoplásica da Expressão Gênica , Telomerase/genética , Adenoma/genética , Adenoma/metabolismo , Adenoma/cirurgia , Neoplasias do Córtex Suprarrenal/metabolismo , Neoplasias do Córtex Suprarrenal/patologia , Neoplasias do Córtex Suprarrenal/cirurgia , Carcinoma Adrenocortical/metabolismo , Carcinoma Adrenocortical/patologia , Carcinoma Adrenocortical/cirurgia , Antígenos CD/metabolismo , Caderinas/metabolismo , Estudos de Casos e Controles , Membrana Celular/metabolismo , Núcleo Celular/metabolismo , Humanos , Antígeno Ki-67/genética , Antígeno Ki-67/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/cirurgia , Regiões Promotoras Genéticas , Telomerase/metabolismo
5.
J Pathol ; 236(4): 517-30, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25875424

RESUMO

Metabolic adaptation is considered an emerging hallmark of cancer, whereby cancer cells exhibit high rates of glucose consumption with consequent lactate production. To ensure rapid efflux of lactate, most cancer cells express high levels of monocarboxylate transporters (MCTs), which therefore may constitute suitable therapeutic targets. The impact of MCT inhibition, along with the clinical impact of altered cellular metabolism during prostate cancer (PCa) initiation and progression, has not been described. Using a large cohort of human prostate tissues of different grades, in silico data, in vitro and ex vivo studies, we demonstrate the metabolic heterogeneity of PCa and its clinical relevance. We show an increased glycolytic phenotype in advanced stages of PCa and its correlation with poor prognosis. Finally, we present evidence supporting MCTs as suitable targets in PCa, affecting not only cancer cell proliferation and survival but also the expression of a number of hypoxia-inducible factor target genes associated with poor prognosis. Herein, we suggest that patients with highly glycolytic tumours have poorer outcome, supporting the notion of targeting glycolytic tumour cells in prostate cancer through the use of MCT inhibitors.


Assuntos
Glicólise , Ácido Láctico/metabolismo , Terapia de Alvo Molecular , Transportadores de Ácidos Monocarboxílicos/metabolismo , Neoplasias da Próstata/metabolismo , Animais , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Proliferação de Células , Progressão da Doença , Desenho de Fármacos , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos Transgênicos , Transportadores de Ácidos Monocarboxílicos/antagonistas & inibidores , Transportadores de Ácidos Monocarboxílicos/genética , Estadiamento de Neoplasias , Fenótipo , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Interferência de RNA , Fatores de Tempo , Transfecção , Carga Tumoral
7.
Dermatol Online J ; 21(1)2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-25612119

RESUMO

Perniosis manifests as inflammatory cutaneous lesions mostly located on acral skin in association with cold and damp conditions. Perniosis of the thighs is quite uncommon and has been associated in the literature with horse riding (equestrian perniosis) or with other recreational activities with long time exposure to cold and humidity. We report a rare case of perniosis of the buttocks and thighs in a 34-year-old healthy woman without a previous history of horse riding or other high-risk activities. In this case, the use of thin and tight clothes is believed to have been enough for the development of perniosis in this susceptible subject.


Assuntos
Pérnio/diagnóstico , Adulto , Nádegas , Pérnio/epidemiologia , Vestuário , Derme/patologia , Edema/patologia , Feminino , Humanos , Recidiva , Fatores de Risco , Coxa da Perna
8.
Environ Monit Assess ; 186(3): 1399-408, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24135921

RESUMO

Proper assessment of soil cadmium (Cd) concentrations is essential to establish legislative limits. The present study aimed to assess background Cd concentrations in soils from the state of São Paulo, Brazil, and to correlate such concentrations with several soil attributes. The topsoil samples (n = 191) were assessed for total Cd contents and for other metals using the USEPA 3051A method. The background concentration was determined according to the third quartile (75th). Principal component analysis, Spearman correlation, and multiple regressions between Cd contents and other soil attributes (pH, cation exchange capacity (CEC), clay content, sum of bases, organic matter, and total Fe, Al, Zn, and Pb levels) were performed. The mean Cd concentration of all 191 samples was 0.4 mg kg(-1), and the background concentration was 0.5 mg kg(-1). After the samples were grouped by parent material (rock origin) and soil type, the background Cd content varied, i.e., soils from igneous, metamorphic, and sedimentary rocks harbored 1.5, 0.4, and 0.2 mg kg(-1) of Cd, respectively. The background Cd content in Oxisols (0.8 mg kg(-1)) was higher than in Ultisols (0.3 mg kg(-1)). Multiple regression demonstrated that Fe was primarily attributed to the natural Cd contents in the soils (R (2) = 0.79). Instead of a single Cd background concentration value representing all São Paulo soils, we propose that the concentrations should be specific for at least Oxisols and Ultisols, which are the primary soil types.


Assuntos
Cádmio/análise , Monitoramento Ambiental , Poluentes do Solo/análise , Solo/química , Brasil , Cádmio/normas , Análise Multivariada , Poluentes do Solo/normas
9.
STAR Protoc ; 4(2): 102305, 2023 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-37178110

RESUMO

We provide a protocol using non-homologous end joining to integrate an oligonucleotide sequence of a fluorescence protein at the CDH1 locus encoding for the epithelial glycoprotein E-cadherin. We describe steps for implementing the CRISPR-Cas9-mediated knock-in procedure by transfecting a cancer cell line with a pool of plasmids. The EGFP-tagged cells are traced by fluorescence-activated cell sorting and validated on DNA and protein levels. The protocol is flexible and can be applied in principle to any protein expressed in a cell line. For complete details on the use and execution of this protocol, please refer to Cumin et al. (2022).1.

10.
Cancer Treat Rev ; 112: 102497, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36525716

RESUMO

High-grade serous ovarian cancers (HGSOCs) most commonly arise from the fimbrial end of the fallopian tube and harbor TP53 gene mutations. In contrast, low-grade serous ovarian cancers (LGSOCs) appear to have different pathological, epidemiological, and clinical features and should be seen as a distinct serous epithelial ovarian cancer subtype. Our current understanding of LGSOC is limited, and treatment has generally been derived from the more common HGSOCs due to a lack of separate trial data. LGSOCs are characterized by slow tumor growth and are assumed to develop from serous borderline ovarian tumors as precursors. These cancers are often estrogen-receptor positive and show an activated mitogen-activated protein kinase pathway together with KRAS and BRAF mutations and, rarely, TP53 mutations. These characteristics are now commonly used to guide therapeutical decision making and, consequently, a substantial part of treatment consists of maintenance with endocrine treatment, thus balancing disease stabilization and mild toxicity. Additionally, new trials are ongoing that examine the role of targeted therapies such as MEK inhibitors in combination with endocrine treatments. The purpose of this work is to summarize current knowledge and present ongoing trial efforts for LGSOCs.


Assuntos
Cistadenocarcinoma Seroso , Neoplasias Ovarianas , Humanos , Feminino , Doenças Raras , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Carcinoma Epitelial do Ovário , Cistadenocarcinoma Seroso/tratamento farmacológico , Cistadenocarcinoma Seroso/genética , Mutação
11.
Sci Total Environ ; 857(Pt 3): 159589, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36270379

RESUMO

Unprecedented human induced changes to the climate system have already contributed to a variety of observed impacts to both ecosystems and populations. Decision-makers demand impact assessments at the regional-to-local scale to be able to plan and define effective climate action measures. Integrated socio-ecological assessments that properly consider system uncertainties require the use of prospective scenarios that project potential climate impacts, while accounting for sectoral exposure and adaptive capacity. Here we provide an integrated assessment of climate change to the whale watching sector by: 1) extending the European Shared Socio-economic Pathways (Eur-SSPs) and developing four whale watching SSP narratives (WW-SSPs) and 2) characterize each key element comprised in the WW-SSPs for the time period 2025-2055. We applied this approach in a case study for the Macaronesia region where we developed scenarios which integrate the socio-economic (WW-SSPs), climate (RCPs) and ecological (species' thermal suitability responses) dimensions of whale watching. These scenarios were used by local stakeholders to identify the level of preparedness of the whale watching sector. When confronted with scenarios that combine this ecological dimension with projected climate changes and the four different socioeconomic narratives, stakeholders assessed the whale watching sector in Macaronesia as being somewhat prepared for a Sustainable World and a Fossil Fuel Development World, but somewhat unprepared for a Rivalry World. No consensus was reached regarding the sector's preparedness level under an Inequality World scenario. Our study demonstrates the importance of considering multiple dimensions when assessing the potential challenges posed by climate change and provides a needed resource to help the whale watching sector in Macaronesia, and elsewhere, in its effort to devise efficient climate action policies and strategies.


Assuntos
Ecossistema , Baleias , Animais , Humanos , Estudos Prospectivos , Mudança Climática , Fatores Socioeconômicos
12.
Nat Commun ; 14(1): 7780, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38012143

RESUMO

Understanding the complex background of cancer requires genotype-phenotype information in single-cell resolution. Here, we perform long-read single-cell RNA sequencing (scRNA-seq) on clinical samples from three ovarian cancer patients presenting with omental metastasis and increase the PacBio sequencing depth to 12,000 reads per cell. Our approach captures 152,000 isoforms, of which over 52,000 were not previously reported. Isoform-level analysis accounting for non-coding isoforms reveals 20% overestimation of protein-coding gene expression on average. We also detect cell type-specific isoform and poly-adenylation site usage in tumor and mesothelial cells, and find that mesothelial cells transition into cancer-associated fibroblasts in the metastasis, partly through the TGF-ß/miR-29/Collagen axis. Furthermore, we identify gene fusions, including an experimentally validated IGF2BP2::TESPA1 fusion, which is misclassified as high TESPA1 expression in matched short-read data, and call mutations confirmed by targeted NGS cancer gene panel results. With these findings, we envision long-read scRNA-seq to become increasingly relevant in oncology and personalized medicine.


Assuntos
Genômica , Neoplasias Ovarianas , Humanos , Feminino , Análise de Sequência de RNA/métodos , Genômica/métodos , Isoformas de Proteínas/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Neoplasias Ovarianas/genética , Transcriptoma/genética , Proteínas de Ligação a RNA
14.
Front Cardiovasc Med ; 10: 1225667, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37692036

RESUMO

Noonan syndrome with multiple lentigines (NSML, formerly known as LEOPARD syndrome) is a variant of Noonan syndrome which is an autosomal dominant disorder. Most cases of NSML are secondary to mutations of the protein-tyrosine phosphatase nonreceptor type 11 (PTPN11). Hypertrophic cardiomyopathy (HCM) remains the most frequent and serious cardiac abnormality in this inherited syndrome, and it may lead to sudden cardiac death related to HCM-associated outflow obstruction and fatal arrhythmia. Beyond cardiac involvement, NSML may present with multiple lentigines, ocular hypertelorism, genital anomalies, short stature and deafness. Herein, we report three patients with NSML among three generations in one family, all presenting with multiple lentigines, HCM and other distinctive clinical and molecular features, including facial dysmorphism, deafness, family history of sudden death and PTPN11 mutations. This case series highlights the importance of early echocardiography examinations for patients with NSML. Careful family screening and genetic counselling are also necessary, especially in patients with diffuse lentigines or a history of sudden death among family members. We also discuss the distinctive cardiac features and phenotypic characteristics at different stages of NSML, including childhood, adulthood and elderhood.

15.
Sci Total Environ ; 860: 160376, 2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36423844

RESUMO

Over the last decades, global warming has contributed to changes in marine species composition, abundance and distribution, in response to changes in oceanographic conditions such as temperature, acidification, and deoxygenation. Experimentally derived thermal limits, which are known to be related to observed latitudinal ranges, have been used to assess variations in species distribution patterns. However, such experiments cannot be undertaken on free-swimming large marine predators with wide-range distribution, like cetaceans. An alternative approach is to elicit expert's knowledge to derive species' thermal suitability and assess their thermal responses, something that has never been tested in these taxa. We developed and applied a methodology based on expert-derived thermal suitability curves and projected future responses for several species under different climate scenarios. We tested this approach with ten cetacean species currently present in the biogeographic area of Macaronesia (North Atlantic) under Representative Concentration Pathways 2.6, 4.5 and 8.5, until 2050. Overall, increases in annual thermal suitability were found for Balaenoptera edeni, Globicephala macrorhynchus, Mesoplodon densirostris, Physeter macrocephalus, Stenella frontalis, Tursiops truncatus and Ziphius cavirostris. Conversely, our results indicated a decline in thermal suitability for B. physalus, Delphinus delphis, and Grampus griseus. Our study reveals potential responses in cetaceans' thermal suitability, and potentially in other highly mobile and large predators, and it tests this method's applicability, which is a novel application for this purpose and group of species. It aims to be a cost-efficient tool to support conservation managers and practitioners.


Assuntos
Balaenoptera , Golfinho Nariz-de-Garrafa , Stenella , Baleias Piloto , Animais , Ecossistema , Clima , Cachalote , Aquecimento Global , Mudança Climática
16.
Biomaterials ; 294: 121996, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36689832

RESUMO

Reliable and predictive experimental models are urgently needed to study metastatic mechanisms of ovarian cancer cells in the omentum. Although models for ovarian cancer cell adhesion and invasion were previously investigated, the lack of certain omental cell types, which influence the metastatic behavior of cancer cells, limits the application of these tissue models. Here, we describe a 3D multi-cellular human omentum tissue model, which considers the spatial arrangement of five omental cell types. Reproducible tissue models were fabricated combining permeable cell culture inserts and bioprinting technology to mimic metastatic processes of immortalized and patient-derived ovarian cancer cells. The implementation of an endothelial barrier further allowed studying the interaction between cancer and endothelial cells during hematogenous dissemination and the impact of chemotherapeutic drugs. This proof-of-concept study may serve as a platform for patient-specific investigations in personalized oncology in the future.


Assuntos
Omento , Neoplasias Ovarianas , Humanos , Feminino , Omento/metabolismo , Omento/patologia , Células Endoteliais/metabolismo , Neoplasias Ovarianas/patologia , Células Cultivadas , Técnicas de Cultura de Células
17.
Front Allergy ; 4: 1290021, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38125294

RESUMO

Background: Urticaria (defined as the presence of hives, angioedema, or both) can be caused by a variety of etiologies ranging from more common conditions such as chronic spontaneous urticaria (CSU) to rarer conditions such as hereditary angioedema (HAE). Specialist referral may be necessary in cases of severe urticaria or HAE, but access to specialist services remains limited in certain regions, such as the Greater Bay Area (GBA) of China. To address this, the Hong Kong-Macau Severe Hives and Angioedema Referral Pathway (SHARP) was initiated by the Hong Kong Institute of Allergy and Macau Society of Dermatology to promote multidisciplinary collaboration and regional exchange of expertise in the diagnosis and management of severe urticaria. Methods: A nominated task force of dermatologists and immunologists who manage patients with severe urticaria formulated the consensus statements (CS) using the Delphi method. The consensus was defined a priori as an agreement of ≥80%. Results: A total of 24 CS were formulated, including four statements on classifications and definitions, seven statements on diagnosis, and 13 statements on management and referral. The definitions for acute/chronic urticaria and severe CSU were stated. Unnecessary investigations and inappropriate medications were discouraged. The characteristics and recommended approach to suspected bradykinergic angioedema were specified. Stepwise treatment options using second-generation antihistamines, omalizumab, or cyclosporin for patients with CSU were addressed, and the importance of access to HAE-specific medications was emphasized. Furthermore, an integrated referral pathway for patients with severe hives and angioedema was constructed. Conclusion: The SHARP provides guidance for the management and specialist referral of patients with severe hives and angioedema in Hong Kong and Macau.

18.
Food Chem ; 412: 135547, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-36716626

RESUMO

Dried and milled eggplant fruit peel and calyces (PC) and mesocarp, placenta and core (Mes) were utilized as natural sources of valuable chemicals. Pectins were extracted with 0.1 M Na2CO3 (1 h; 23 °C). A high-power ultrasound (US) pretreatment (10 min net time; 12.76 W/cm2 power intensity) in 10:200 (g/mL) powder:water ratio led to the lowest solvent and energy consumptions after the subsequent 0.1 M Na2CO3 stirring, permitting the highest recoveries of uronic acid (UA) from PC and Mes (80.25 and 93.8 %, respectively). Homogalacturonans (>65 % w/w UA) of low degree of methylesterification, of acetylation, and 90,214-138,184 Da molecular weights with low polydispersity (≈1.32-1.40) were obtained. They included released ferulate (≈3.5 mg/100 g) esterified pectins. Antioxidants (caffeoylquinic acid, putrescine and spermidine derivatives, ß-carotene, lutein) gave additional technological value to their thickening effect as pectins protected tryptophan, tyrosine, alkyl side chains and sulfhydryl of skim milk proteins from UV-C photo-oxidation.


Assuntos
Antioxidantes , Solanum melongena , Antioxidantes/análise , Solanum melongena/química , Frutas/química , Pectinas/metabolismo
19.
Acta Crystallogr D Biol Crystallogr ; 68(Pt 11): 1468-78, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23090396

RESUMO

The crystal structure of wild-type endo-ß-D-1,4-mannanase (EC 3.2.1.78) from the ascomycete Chrysonilia sitophila (CsMan5) has been solved at 1.40 Å resolution. The enzyme isolated directly from the source shows mixed activity as both an endo-glucanase and an endo-mannanase. CsMan5 adopts the (ß/α)(8)-barrel fold that is well conserved within the GH5 family and has highest sequence and structural homology to the GH5 endo-mannanases. Superimposition with proteins of this family shows a unique structural arrangement of three surface loops of CsMan5 that stretch over the active centre, promoting an altered topography of the binding cleft. The most relevant feature results from the repositioning of a long loop at the extremity of the binding cleft, resulting in a shortened glycone-binding region with two subsites. The other two extended loops flanking the binding groove produce a narrower cleft compared with the wide architecture observed in GH5 homologues. Two aglycone subsites (+1 and +2) are identified and a nonconserved tryptophan (Trp271) at the +1 subsite may offer steric hindrance. Taken together, these findings suggest that the discrimination of mannan substrates is achieved through modified loop length and structure.


Assuntos
Neurospora/enzimologia , beta-Manosidase/química , Sequência de Aminoácidos , Domínio Catalítico , Cristalografia por Raios X , Modelos Moleculares , Dados de Sequência Molecular , Neurospora/química , Conformação Proteica , Alinhamento de Sequência , Especificidade por Substrato , beta-Manosidase/metabolismo
20.
Dermatol Online J ; 18(11): 13, 2012 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-23217954

RESUMO

Paroxysmal nocturnal hemoglobinuria is a clonal stem cell disorder typically characterized by hemolysis, bone marrow failure, and venous thrombosis. The latter can affect up to 40 percent of patients and is a significant cause of mortality. Despite being recognized as a possible complication, cutaneous thrombosis is quite uncommon and a variety of findings have been reported. Owing to the rarity of this complication and the importance of its correct and timely diagnosis, we report the case of a 64-year-old man with paroxysmal nocturnal hemoglobinuria who presented with isolated and well-demarcated erythematous-violaceous plaques, mainly located on the neck and trunk. Given the history and the histological features, the diagnosis of cutaneous thrombosis related to paroxysmal nocturnal hemoglobinuria was assumed and the patient was successfully treated with therapeutic anticoagulation. The early identification of these patients is essential for necessary surveillance because they could carry a higher probability of recurrence compared with those with no prior complications.


Assuntos
Hemoglobinúria Paroxística/complicações , Dermatopatias Vasculares/complicações , Trombose/complicações , Hemoglobinúria Paroxística/patologia , Humanos , Masculino , Pessoa de Meia-Idade
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