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1.
Appl Microbiol Biotechnol ; 106(13-16): 5035-5049, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35799069

RESUMO

Valorization of the hemicellulose fraction of plant biomass is crucial for the sustainability of lignocellulosic biorefineries. The Cellulomonas genus comprises Gram-positive Actinobacteria that degrade cellulose and other polysaccharides by secreting a complex array of enzymes. In this work, we studied the specificity and synergy of two enzymes, CsXyn10A and CsAbf62A, which were identified as highly abundant in the extracellular proteome of Cellulomonas sp. B6 when grown on wheat bran. To explore their potential for bioprocessing, the recombinant enzymes were expressed and their activities were thoroughly characterized. rCsXyn10A is a GH10 endo-xylanase (EC 3.2.1.8), active across a broad pH range (5 to 9), at temperatures up to 55 °C. rCsAbf62A is an α-L-arabinofuranosidase (ABF) (EC 3.2.1.55) that specifically removes α-1,2 and α-1,3-L-arabinosyl substituents from arabino-xylo-oligosaccharides (AXOS), xylan, and arabinan backbones, but it cannot act on double-substituted residues. It also has activity on pNPA. No differences were observed regarding activity when CsAbf62A was expressed with its appended CBM13 module or only the catalytic domain. The amount of xylobiose released from either wheat arabinoxylan or arabino-xylo-oligosaccharides increased significantly when rCsXyn10A was supplemented with rCsAbf62A, indicating that the removal of arabinosyl residues by rCsAbf62A improved rCsXyn10A accessibility to ß-1,4-xylose linkages, but no synergism was observed in the deconstruction of wheat bran. These results contribute to designing tailor-made, substrate-specific, enzymatic cocktails for xylan valorization. KEY POINTS: • rCsAbf62A removes α-1,2 and α-1,3-L-arabinosyl substituents from arabino-xylo-oligosaccharides, xylan, and arabinan backbones. • The appended CBM13 of rCsAbf62A did not affect the specific activity of the enzyme. • Supplementation of rCsXyn10A with rCsAbf62A improves the degradation of AXOS and xylan.


Assuntos
Cellulomonas , Xilanos , Cellulomonas/genética , Cellulomonas/metabolismo , Fibras na Dieta , Endo-1,4-beta-Xilanases/metabolismo , Glicosídeo Hidrolases/metabolismo , Hidrólise , Oligossacarídeos/metabolismo , Especificidade por Substrato , Xilanos/metabolismo
2.
J Org Chem ; 86(13): 8742-8754, 2021 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-34128666

RESUMO

A general and efficient method for the deconjugative α-alkylation of α,ß-unsaturated aldehydes promoted by a synergistic effect between tBuOK and NaH, which considerably increases the reaction rate under mild conditions, is reported. The ß,γ-unsaturated aldehyde, resulting from the α-alkylation, is transformed in high yield into the corresponding allyl acetate via a lead(IV) acetate-mediated oxidative fragmentation. This strategy could be used for the construction of the carbon skeleton of a wide variety of alkyl or arylterpenoids.


Assuntos
Aldeídos , Terpenos , Alquilação , Oxirredução , Estereoisomerismo
3.
Pol Przegl Chir ; 92(5): 1-5, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32945262

RESUMO

<b>Introduction:</b> Giant groin hernia is an unusual disease nowadays and its management can be a challenge for surgeons. The application of botulinum toxin A as a preoperative therapy could decrease the thickness of the lateral wall muscles, increase their length and increase the volume of the abdominal cavity facilitating the surgical repair. Morbidity and mortality due to high intra-abdominal pressure would decrease, allowing a minimal tension closure after reduction of the herniated viscera. <br><b>Case report:</b> We present the repair of two cases of massive inguinal hernia with loss of domain using preoperative abdominal wall injection of botulinum toxin.


Assuntos
Toxinas Botulínicas Tipo A/administração & dosagem , Hérnia Inguinal/cirurgia , Herniorrafia/métodos , Fármacos Neuromusculares/administração & dosagem , Parede Abdominal/cirurgia , Idoso , Virilha/cirurgia , Hérnia Inguinal/tratamento farmacológico , Humanos , Masculino , Dor Pós-Operatória/prevenção & controle
4.
Antibiotics (Basel) ; 9(8)2020 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-32781770

RESUMO

Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) have become serious infections in humans and ruminants. S. aureus strains are showing rapid changes to develop resistance in traditional antibiotic-containing systems. In the continuous fierce fight against the emergent multi-drug resistant bacterial strains, straightforward and scalable synthetic procedures to produce new active molecules are in demand. Analysis of molecular properties points to degraded limonoids as promising candidates. In this article, we report a simple synthetic approach to obtain degraded limonoid analogs as scaffolds for new antibacterial molecules. The minimum inhibitory concentrations against S. aureus were evaluated for the stereoisomer mixtures by the broth microdilution method. Analysis of results showed that the acetylated derivatives were the most active of them all.

5.
J Proteomics ; 193: 239-242, 2019 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-30385413

RESUMO

Nannochloropsis gaditana is a non-flagellated microalgae that has been widely used for different purposes, mostly related with the industrial production of biofuels or aquiculture. However, in order to increase the economic viability of the obtained microalgae biomass from a production plant coupled to a coal power plant, a proteomic approach was initiated by using fresh and atomized microalgae samples, as the main used commercial forms. Above 51,000 high quality spectra were obtained per sample in the MS/MS analysis of whole proteome of N. gaditana, yielding above 7,500 peptides, leading the identification of 1,950 proteins, from the N. gaditana protein database, where 655 proteins were presented in all the replicates. The identified proteins were categorized according to gene ontology classification by molecular function and biological process. In this study, it has been described the first proteomic analysis of the microalgae N. gaditana under industrial conditions containing an important number of identified proteins. A significative presence of proteins with a potential role in different agri-food and biomedical applications was detected and studied being the core of future N. gaditana research to expand the current biotechnological applications of this microalga. SIGNIFICANCE OF THE STUDY: Three quarters of the planet earth correspond to seas and oceans, however its potential biotechnological use is still unknown. We described the first proteomic description of the microalgae N. gaditana under industrial conditions. Following the spirit of the EU initiatives of blue growth and the statements of circular economy, CO2 waste from a coal plant power has been transformed in a resource for microalgae biomass production, common product presentations were evaluated by proteomic, and its potential use of identified proteins in Agri-food and Biomedicine has been revealed.


Assuntos
Bases de Dados de Proteínas , Microalgas/crescimento & desenvolvimento , Peptídeos/metabolismo , Proteoma/metabolismo , Proteômica , Estramenópilas/crescimento & desenvolvimento
6.
New Phytol ; 218(3): 1049-1060, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29460505

RESUMO

Insights into the evolution of plant cell walls have important implications for comprehending these diverse and abundant biological structures. In order to understand the evolving structure-function relationships of the plant cell wall, it is imperative to trace the origin of its different components. The present study is focused on plant 1,4-ß-xylan, tracing its evolutionary origin by genome and transcriptome mining followed by phylogenetic analysis, utilizing a large selection of plants and algae. It substantiates the findings by heterologous expression and biochemical characterization of a charophyte alga xylan synthase. Of the 12 known gene classes involved in 1,4-ß-xylan formation, XYS1/IRX10 in plants, IRX7, IRX8, IRX9, IRX14 and GUX occurred for the first time in charophyte algae. An XYS1/IRX10 ortholog from Klebsormidium flaccidum, designated K. flaccidumXYLAN SYNTHASE-1 (KfXYS1), possesses 1,4-ß-xylan synthase activity, and 1,4-ß-xylan occurs in the K. flaccidum cell wall. These data suggest that plant 1,4-ß-xylan originated in charophytes and shed light on the origin of one of the key cell wall innovations to occur in charophyte algae, facilitating terrestrialization and emergence of polysaccharide-based plant cell walls.


Assuntos
Parede Celular/metabolismo , Carofíceas/enzimologia , Pentosiltransferases/metabolismo , Células Vegetais/metabolismo , Motivos de Aminoácidos , Vias Biossintéticas , Carofíceas/genética , Evolução Molecular , Células HEK293 , Humanos , Pentosiltransferases/química , Filogenia
7.
Nat Prod Commun ; 12(5): 671-673, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-30496672

RESUMO

Two new macrocyclic diterpenes, 2-epi-latazienone (4) and 15ß-acetoxy-7ß-nicotinoyloxy-3ß,8α-di-(2-methylpropanoyloxy)-4αH,9αH,l1αH-lathyra- 5E,12E-dien-14-one (5), and three known lathyrane-type diterpenes (1-3) were isolated from Euphorbia laurifolia latex. Their structures were determined on the basis of a detailed analysis of their 1D and 2D NMR spectroscopic and mass spectral data.


Assuntos
Diterpenos/química , Euphorbia/química , Látex/química , Extratos Vegetais/química , Estrutura Molecular
8.
European J Org Chem ; 2016(21): 3584-3591, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27840587

RESUMO

A method has been developed for the conversion of primary, secondary, and tertiary alcohols, and phenol, into the corresponding esters at room temperature. The method uses a titanium(III) species generated from a substoichiometric amount of titanocene dichloride together with manganese(0) as a reductant, as well as methylene diiodide. It involves a transesterification from an ethyl ester, or a reaction with an acyl chloride. A radical mechanism is proposed for these transformations.

9.
Chemistry ; 22(22): 7609-16, 2016 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-27112785

RESUMO

The reaction of excess TMSCl and LiCCl2 Br at low temperature is a technically simple high yield route to TMSCCl2 Br. The latter is a stable source of the dichlorobromomethide carbanion, which undergoes 1,4-addition with cyclic nitroalkenes and (E)-fumarates leading to dichlorocyclopropanes after bromide expulsion. For nitrostyrenes the reaction arrests at the 1,4-addition product. Low temperature NMR spectroscopy studies and DFT calculations suggest the formation of an "ate" species [(nitronate)SiFMe3 ](-) which, upon boil-off of TMSF at 10-20 °C, yields the cyclopropane. DFT calculations also support the experimental differences between fluoride and acetate as promotors.

10.
Nat Prod Rep ; 32(8): 1236-48, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25994531

RESUMO

The biological activities of aristolane, aromadendrane, ent-1,10-secoaromadendrane, 2,3-secoaromadendrane, ent-5,10-cycloaromadendrane, bicyclogermacrene, lepidozane, and maaliane terpenoids which contain the gem-dimethylcyclopropyl unit are described. Particular attention is given to their anti-viral, anti-microbial and cytotoxic activities. In the main text there are 119 references covering the literature from 1963-2014. The ESI contains tables listing 332 of these terpenoids, their occurrence and biological activity together with the related references.


Assuntos
Produtos Biológicos , Sesquiterpenos , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Humanos , Estrutura Molecular , Sesquiterpenos/química , Sesquiterpenos/farmacologia
11.
Bioorg Med Chem ; 23(13): 3379-87, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25971873

RESUMO

Solvent-free desymmetrisation of meso-dialdehyde 1 with chiral 1-phenylethan-1-ol, led to preparation of 4-silyloxy-6-alkyloxytetrahydro-2H-pyran-2-one (+)-3a with a 96:4 dr Deprotected lactone (+)-19a and the related racemic lactones 16a-18a present a lactone moiety resembling the natural substrate of HMG-CoA reductase and their antifungal properties have been evaluated against the phytopathogenic fungi Botrytis cinerea and Colletotrichum gloeosporioides. These compounds were selectively active against B. cinerea, while inactive against C. gloeosporioides.


Assuntos
Botrytis/efeitos dos fármacos , Colletotrichum/efeitos dos fármacos , Fungicidas Industriais/síntese química , Glutaral/análogos & derivados , Piranos/síntese química , Aldeídos/química , Botrytis/crescimento & desenvolvimento , Botrytis/isolamento & purificação , Colletotrichum/crescimento & desenvolvimento , Colletotrichum/isolamento & purificação , Contagem de Colônia Microbiana , Fungicidas Industriais/farmacologia , Glutaral/química , Hidroximetilglutaril-CoA-Redutases NADP-Dependentes/química , Lactonas/química , Mimetismo Molecular , Álcool Feniletílico/química , Doenças das Plantas/microbiologia , Piranos/farmacologia , Estereoisomerismo , Relação Estrutura-Atividade , Vitis/microbiologia
12.
J Org Chem ; 79(23): 11349-58, 2014 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-25372296

RESUMO

The structure 3,4-dihydroxy-2,4,6,8-tetramethyldec-8-enolide (1) was assigned to a metabolite of Botrytis cinerea, but the spectra of several synthetic analogues had significant differences from that of 1. Examination of the constituents of a B. cinerea mutant that overproduces polyketides gave sufficient quantities of 1, now named cinbotolide, for chemical transformations. These led to a revised γ-butyrolactone structure for the metabolite. This structure has been confirmed by an asymmetric total synthesis, which also established its absolute configuration.


Assuntos
4-Butirolactona/química , Macrolídeos/química , Policetídeos/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Policetídeos/síntese química , Estereoisomerismo
13.
Nat Prod Rep ; 31(7): 940-52, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24844588

RESUMO

Covering: 1973 to 2013. The biological activities of tigliane, lathyrane, ingenane, casbane, jatropholane and premyrsinane diterpenoids which contain the gem-dimethylcyclopropyl unit are described. Particular attention is given to their anti-viral, anti-microbial and cytotoxic activities. In the main text there are 132 references. The electronic supplementary information contains tables listing 424 of these diterpenoids, their occurrence and biological activity together with the references.


Assuntos
Produtos Biológicos , Ciclopropanos , Diterpenos , Proteína Quinase C/antagonistas & inibidores , Animais , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/farmacologia , Ciclopropanos/química , Ciclopropanos/isolamento & purificação , Ciclopropanos/farmacologia , Diterpenos/química , Diterpenos/isolamento & purificação , Diterpenos/farmacologia , Humanos , Camundongos , Estrutura Molecular
14.
J Neural Transm (Vienna) ; 121(2): 139-45, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24078167

RESUMO

Visual symptoms are common among the nonmotor symptoms in Parkinson's disease. The aims of this study were to assess the diagnostic accuracy and relationship of retinal morphologic and functional changes with motor and non-motor symptoms disturbances in Parkinson's disease. Thirty patients with Parkinson's disease, with a median Hoehn-Yahr stage of 2 (1-4), were compared to 30 age- and gender-matched controls. Retinal thinning and function were measured using optical coherence tomography (OCT), visual evoked potentials (VEP), and pattern electroretinography. Motor impairment and motor laterality were measured using the Short Parkinson's Evaluation Scale/Scales for Outcomes in Parkinson's disease, and non-motor symptoms severity using the nonmotor symptoms questionnaire. Only pattern electroretinography, P50 and N95 amplitudes, were lower in patients with Parkinson's disease, compared to controls (p = 0.01, respectively). Age, disease duration, levodopa dose, motor, and non-motor impairment were not significantly associated with retinal thinning and functional changes. The patients vs. controls area under the curve of OCT, VEP, and pattern electroretinography receiver-operating-characteristic curves were<0.50. In conclusion, morphologic and functional retina changes are not significantly correlated with motor and non-motor symptoms impairment severity, and do not discriminate between Parkinson's disease and controls.


Assuntos
Atividade Motora/fisiologia , Doença de Parkinson/patologia , Retina/patologia , Retina/fisiopatologia , Transtornos da Visão/etiologia , Idoso , Estudos de Casos e Controles , Estudos Transversais , Eletrorretinografia , Potenciais Evocados Visuais/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/complicações , Curva ROC , Tomografia de Coerência Óptica
15.
Breast ; 21(1): 95-101, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21924904

RESUMO

OBJECTIVE: Baseline bone health in postmenopausal women is poorly characterized in prospective series of early breast cancer (EBC) patients candidates to aromatase inhibitor (AI) therapy. Our objective is to comprehensively evaluate bone health in a prospective clinical cohort of patients recruited prior to adjuvant AI therapy, with the aim of establishing potential AI impact on bone loss and fractures. METHODS: From January 2006 to April 2010, we consecutively included 343 women with EBC who were about to start adjuvant AI therapy. Participants were assessed at baseline (before AI initiation) and at 3 months, with annual assessments thereafter. Bone mineral density (BMD), spine X-ray, bone metabolism (vitamin D [25(OH)D], bone turnover markers [BTM]), arthralgia and quality of life are measured. RESULTS: Mean age was 61.9 years; 197 (57.4%) had been previously treated with tamoxifen; 145 (42.3%) were taking exemestane, 187 (54.5%) letrozole, and 11 (3.2%) anastrozole. Analysis of baseline data shows only 59 women (17.7%) had normal BMD; 200 (60.1%) had osteopenia and 74 (22.2%) had osteoporosis; 39 women (11.4%) had a prevalent fracture, 293 (89.1%) had 25(OH)D insufficiency (<30 ng/ml), and 61 (18.5%) severe deficiency (<10 ng/ml). Low 25(OH)D concentrations were associated with lower BMD and 233 (67.9%) participants had some degree of arthralgia. CONCLUSIONS: Low bone mass, prevalent fractures and vitamin D insufficiency were highly prevalent among candidates to adjuvant AI for EBC. Therefore, it is crucial to assess BMD, prevalent fractures and 25(OH)D concentrations before starting AI therapy and during follow-up.


Assuntos
Inibidores da Aromatase/efeitos adversos , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Neoplasias da Mama/tratamento farmacológico , Idoso , Inibidores da Aromatase/farmacologia , Inibidores da Aromatase/uso terapêutico , Densidade Óssea , Remodelação Óssea/efeitos dos fármacos , Remodelação Óssea/fisiologia , Reabsorção Óssea/induzido quimicamente , Reabsorção Óssea/prevenção & controle , Feminino , Fraturas Espontâneas/induzido quimicamente , Fraturas Espontâneas/prevenção & controle , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Qualidade de Vida
16.
Cir. Esp. (Ed. impr.) ; 88(2): 103-109, ago. 2010. tab
Artigo em Espanhol | IBECS | ID: ibc-135808

RESUMO

Introducción: La cirugía bariátrica es la opción más eficaz para el tratamiento de los pacientes con alto riesgo de complicaciones por su obesidad. Sin embargo provoca una serie de alteraciones metabólicas sobre el calcio y la vitamina D y un aumento de la resorción que conllevan una pérdida de masa ósea. Objetivo: El objetivo del estudio es la comparación de la gastrectomía tubular (GT) con el bypass gástrico en Y de Roux (BGYR) respecto la pérdida de masa ósea medida mediante densitometría y marcadores de remodelado óseo. Pacientes y métodos: Se incluyeron 15 mujeres con obesidad mórbida, 8 en la GT y 7 en el BGYR, de edad media 47,8±9 con un índice de masa corporal 43,3±3,4. Se realizaron mediciones de la masa ósea a nivel de columna, fémur y tercio distal del radio y marcadores de remodelado óseo N-telopéptido (NTx), y fosfatasa alcalina específica ósea (FAO), así como niveles de vitamina D antes y a los 12 meses de la intervención. Resultados: Se observó una pérdida significativa de masa ósea con la GT y el BGYR, en columna lumbar y cadera mientras que en el radio no se observaron diferencias significativas. El porcentaje de pérdida de masa ósea fue menor en columna y fémur tras la GT que con el BGYR, aunque sin llegar a la significación estadística, 4,6&%#x000B1;4,4 (media±DE) y 6,3&%#x000B1;5,4 (media±DE) respectivamente. A los 12 meses el NTx aumentó para ambos tipos de intervención y las FAO aumentaron solo para la GT. Conclusión: La GT provoca una pérdida menor de masa ósea, aunque no significativa, respecto el BGYR (AU)


Introduction: Bariatric surgery is the most effective option for the treatment of patients with a high risk of complications due to their obesity. However, it brings about a series of changes in calcium and vitamin D metabolism and an increase in resorption which lead to a loss of bone mass. Aim: The objective of this study is to compare sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) as regards loss of bone mass using bone densitometry and bone remodelling markers. Patients and methods: Fifteen women with morbid obesity were included, 8 by SG and 7 by RYGB, with a mean age of 47.8±9 and mean body mass index 43.3±3.4. Bone mass measurements were made on the lumbar spine, femur and distal radius, and the bone remodelling markers N-telopeptide (NTx) and bone alkaline phosphatase (BALP), as well as vitamin D levels before and 12 months after surgery. Results: A significant bone mass loss was observed was observed with SG and RYGB, in the lumbar spine and hip, whilst no differences were observed in the radial. The percentage bone mass loss was less in the column and femur after SG than with RYGB, although it did not reach statistical significance, 4.6&%#x000B1;4.4 (mean±SD) and 6.3&%#x000B1;5.4 (mean±SD), respectively. At 12 months the Ntx increased for both types of surgery, and the BAP was only increased for SG. Conclusion: SG causes less, although not significant, bone mass loss compared to RYGB (AU)


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Densidade Óssea , Doenças Ósseas Metabólicas/etiologia , Gastrectomia/efeitos adversos , Gastrectomia/métodos , Derivação Gástrica/efeitos adversos , Obesidade Mórbida/cirurgia , Projetos Piloto , Estudos Prospectivos
17.
Cir Esp ; 88(2): 103-9, 2010 Aug.
Artigo em Espanhol | MEDLINE | ID: mdl-20619402

RESUMO

INTRODUCTION: Bariatric surgery is the most effective option for the treatment of patients with a high risk of complications due to their obesity. However, it brings about a series of changes in calcium and vitamin D metabolism and an increase in resorption which lead to a loss of bone mass. AIM: The objective of this study is to compare sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) as regards loss of bone mass using bone densitometry and bone remodelling markers. PATIENTS AND METHODS: Fifteen women with morbid obesity were included, 8 by SG and 7 by RYGB, with a mean age of 47.8+/-9 and mean body mass index 43.3+/-3.4. Bone mass measurements were made on the lumbar spine, femur and distal radius, and the bone remodelling markers N-telopeptide (NTx) and bone alkaline phosphatase (BALP), as well as vitamin D levels before and 12 months after surgery. RESULTS: A significant bone mass loss was observed was observed with SG and RYGB, in the lumbar spine and hip, whilst no differences were observed in the radial. The percentage bone mass loss was less in the column and femur after SG than with RYGB, although it did not reach statistical significance, 4.6%+/-4.4 (mean+/-SD) and 6.3%+/-5.4 (mean+/-SD), respectively. At 12 months the Ntx increased for both types of surgery, and the BAP was only increased for SG. CONCLUSION: SG causes less, although not significant, bone mass loss compared to RYGB.


Assuntos
Densidade Óssea , Doenças Ósseas Metabólicas/etiologia , Gastrectomia/efeitos adversos , Gastrectomia/métodos , Derivação Gástrica/efeitos adversos , Obesidade Mórbida/cirurgia , Feminino , Humanos , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos
19.
Maturitas ; 66(3): 291-7, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20399042

RESUMO

OBJECTIVE: Aromatase inhibitors (AI) treatment leads to an increased risk of bone loss and fractures. In a group of women with early breast cancer (EBC) and baseline Vitamin D deficiency (<30 ng/ml) who are treated with AI, we aim to describe: serum levels of Vitamin D, bone mineral density (BMD), calcium intake, and the increase of serum 25(OH)D accomplished in 3 months of treatment with Vitamin D supplements. STUDY DESIGN: Prospective, non-randomized clinical trial. METHODS: In 232 consecutively included women with EBC in treatment with AI, we assessed baseline calcium intake, serum levels of 25(OH)D, BMD and, spine X-ray. All received Calcium and Vitamin D supplements, and those with vitamin deficiency received 16,000 IU Vitamin D every 2 weeks. Serum levels of 25(OH)D were newly assessed after treatment. All the baseline evaluation was performed before starting AI treatment. RESULTS: Mean age at baseline (+/-SD) was 63.2+/-8.8 years. In 150 (64.9%) cases, the women had been treated previously with tamoxifen; 101 (43.7%) started exemestane, 119 (51.5%) letrozole, and 11 (4.8%) anastrozole. The AI were initiated within 6 weeks after surgery or after the last cycle of chemotherapy. At baseline, 88.1% had 25(OH)D levels <30 ng/ml, 21.2% had severe deficiency (<10 ng/ml), and 25% of the participants had osteoporosis. Mean daily calcium intake was low (841+/-338). We found a significant association between 25(OH)D levels and BMD at baseline, which remained significant in femoral neck BMD after multivariate adjustment. Plasma 25(OH)D levels improved significantly at 3 months follow-up in those treated with high dose Vitamin D supplements: mean increase 32.55 ng/ml (95%CI 28.06-37.03). CONCLUSIONS: Our study suggests a high prevalence of commonly unrecognized Vitamin D deficiency in women with EBC treated with AI, a known osteopenic agent. Our results support the need for a routine assessment of 25(OH)D levels and, when necessary, supplementation in these patients.


Assuntos
Inibidores da Aromatase/efeitos adversos , Densidade Óssea/efeitos dos fármacos , Neoplasias da Mama/complicações , Osteoporose Pós-Menopausa , Deficiência de Vitamina D , Vitamina D/análogos & derivados , Vitamina D/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/administração & dosagem , Inibidores da Aromatase/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Cálcio/administração & dosagem , Feminino , Fêmur , Humanos , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/complicações , Osteoporose Pós-Menopausa/tratamento farmacológico , Osteoporose Pós-Menopausa/epidemiologia , Pós-Menopausa , Estudos Prospectivos , Vitamina D/sangue , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/tratamento farmacológico , Deficiência de Vitamina D/epidemiologia
20.
J Bone Miner Res ; 25(8): 1877-85, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20200991

RESUMO

Bone tissue mechanical properties are deemed a key component of bone strength, but their assessment requires invasive procedures. Here we validate a new instrument, a reference point indentation (RPI) instrument, for measuring these tissue properties in vivo. The RPI instrument performs bone microindentation testing (BMT) by inserting a probe assembly through the skin covering the tibia and, after displacing periosteum, applying 20 indentation cycles at 2 Hz each with a maximum force of 11 N. We assessed 27 women with osteoporosis-related fractures and 8 controls of comparable ages. Measured total indentation distance (46.0 +/- 14 versus 31.7 +/- 3.3 microm, p = .008) and indentation distance increase (18.1 +/- 5.6 versus 12.3 +/- 2.9 microm, p = .008) were significantly greater in fracture patients than in controls. Areas under the receiver operating characteristic (ROC) curve for the two measurements were 93.1% (95% confidence interval [CI] 83.1-100) and 90.3% (95% CI 73.2-100), respectively. Interobserver coefficient of variation ranged from 8.7% to 15.5%, and the procedure was well tolerated. In a separate study of cadaveric human bone samples (n = 5), crack growth toughness and indentation distance increase correlated (r = -0.9036, p = .018), and scanning electron microscope images of cracks induced by indentation and by experimental fractures were similar. We conclude that BMT, by inducing microscopic fractures, directly measures bone mechanical properties at the tissue level. The technique is feasible for use in clinics with good reproducibility. It discriminates precisely between patients with and without fragility fracture and may provide clinicians and researchers with a direct in vivo measurement of bone tissue resistance to fracture.


Assuntos
Osso e Ossos/anatomia & histologia , Osso e Ossos/fisiologia , Fraturas Ósseas/diagnóstico , Fraturas Ósseas/fisiopatologia , Ortopedia/métodos , Fenômenos Biomecânicos/fisiologia , Osso e Ossos/ultraestrutura , Cadáver , Feminino , Fraturas Ósseas/complicações , Fraturas Ósseas/patologia , Humanos , Osteoporose/complicações , Osteoporose/diagnóstico , Curva ROC , Doadores de Tecidos
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