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1.
Sci Total Environ ; 738: 139780, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-32526411

RESUMO

Acidic Mine Waters (AMWs) are characterised by high acidity (pH < 3) as H2SO4 and elevated contents of metals (Al, Fe, Cu, Zn), including rare earth elements (REEs). Due to the exhaustion of minable REE containing-minerals, AMWs are increasingly regarded as an alternative source of REEs. Among the different alternatives for the pre-concentration of AMWs required to make the REE extraction possible, nanofiltration (NF) membranes emerge as a promising technology because they not only successfully reject multivalent ions (metals), allowing its concentration in the retentate stream, but also permit the transport of monovalent ones, such as H+ and HSO4-, allowing the recovery of sulphuric acid in the permeate. Despite this potential of NF, there is still a lack of modelling tools for predicting the performance of NF membranes because of its dependence on solution composition, membrane properties and interaction between both. In this study, a prediction tool based on the Solution-Electro-Diffusion model (including the effect of solution composition) was developed and experimentally validated for the application of two polyamide-based NF membranes (NF270 and Desal DL) for the recovery of REEs and H2SO4 from three different synthetic solutions mimicking AMWs (pH 1.0, 60 mg/L REEs and, 25-600 mg/L Al, Cu, Ca and Zn) differing in their Fe concentration (0-2125 mg/L). Metals were effectively rejected (>98%), whereas H2SO4 was transported across the membrane (H+ rejections <30%). The mathematical model was able to predict the performance of both membranes as well as the potential scaling events associated with Fe and Al hydroxides and hydroxy-sulphates.

2.
Chemosphere ; 245: 125606, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31855756

RESUMO

The accumulation of ammonia in water bodies can cause eutrophication and reduce water quality. Furthermore, 80% of the ammonia in the world is consumed as fertilizer, which makes it a resource that can be recovered under the circular economy concept. Then, ammonia from wastewater can be valorised for agricultural applications. Liquid-liquid membrane contactors (LLMCs) have been postulated as a novel and eco-friendly technology for ammonia recovery, because they can convert dissolved ammonia into ammonium salts by an acid stripping solution. The concentration of the ammonium salt produced is limited by the co-transport of water in LLMC. Further concentration by electrodialysis (ED) is presented as a solution to overcome this problem. In this work, ammonia streams with different initial ammonia concentrations (1.7-4.0 g/L) were treated by LLMCs to produce liquid ammonium salt fertilizers (as NH4NO3 and NH4H2PO4). Then, these ammonium solutions were concentrated by ED in order to achieve the nitrogen content required for direct application in agriculture for fertigation. After the LLMC process, the fertilizer obtained was composed of approximately 5.1% or 10.1% (w/w) nitrogen, depending on the initial ammonia concentration. After that, it was possible to concentrate these ammonium salts by a factor of 1.6 ± 0.3 using ED with an optimal energy consumption of 0.21 ± 0.08 kWh/kg ammonium salt and 93.1 ± 4.2% of faradaic yield. This gave a liquid fertilizer composed of 15.6% (w/w) nitrogen as NH4NO3. Overall, it was possible to integrate two innovative membrane technologies for the valorisation and concentration of nutrients from ammonia wastewater streams.


Assuntos
Amônia/isolamento & purificação , Compostos de Amônio/química , Fertilizantes , Membranas Artificiais , Águas Residuárias/química , Agricultura/métodos , Amônia/análise , Nitrogênio/análise , Reciclagem
3.
Rev. cuba. invest. bioméd ; 38(2): 170-181, abr.-jun. 2019. tab
Artigo em Espanhol | LILACS-Express | LILACS, CUMED | ID: biblio-1093398

RESUMO

Introducción: La técnica del remate es un fundamento técnico-táctico ofensivo primordial en el voleibol, ayudando al equipo a conseguir puntos, y por ende imprescindible para la victoria. Potenciar el hábito motriz implica optimizar la preparación deportiva en todos los niveles. Objetivo: Analizar biomecánicamente las fases del remate de voleibol y variables mecánicas relacionadas en jugadores prejuveniles y juveniles de la Concentración Deportiva de Pichincha. Métodos: Bajo un muestreo intencional no probabilístico, se estudió a 19 voleibolistas del sexo femenino (11 prejuveniles y 8 juveniles) probando biomecánicamente 5 fases del movimiento técnico del remate. Se ensayó el Tiempo Total del Remate, el Tiempo de la Preparación hasta el Golpe y el Ángulo del Cuerpo en Relación al Centro de Gravedad. Resultados: En las 5 fases de la técnica del remate solo existió una diferencia significativa entre los grupos independientes estudiados (Fase 4: p= 0,001) perteneciente al ángulo del codo en la fase de golpeo al balón (menor rango promedio el grupo juvenil: 5,38), el resto no indicó diferencias significativas, aunque los rangos promedios fueron menores en el grupo prejuvenil en la fase 1, 2, 3, y mayores en el mismo grupo para el caso de la 5ta fase (ángulo de la columna: 11,91). Por otra parte, solo se evidenció diferencias significativas en TTR (p= 0,033), y no significativas en el Tiempo de la Preparación hasta el Golpe (TPG: p= 0,717) y el ángulo del cuerpo en relación al centro de gravedad (ACCG: p= 0,717). Conclusiones: Los ángulos de la columna no influyen significativamente en la técnica del remate; no obstante, en los ángulos del codo se observó influencia para una mejor flexión de codo y colocación de la mano, pudiendo generar un mayor impacto al balón y por ende mayores dificultades a la defensa oponente(AU)


Introduction: Spike technique is a fundamental technical-tactical offensive movement in volleyball. It helps the team score points and is therefore essential to win. Strengthening motor skills implies optimizing sport preparation on all levels. Objective: Biomechanically analyze volleyball spike phases and mechanical variables as performed by junior and youth players from Pichincha sports complex. Methods: Nineteen female volleyball players (11 junior and 8 youth) were selected by intentional non-probabilistic sampling to conduct a biomechanical study of the five phases of the technical movement of spike, alongside Total Spike Time (TST), Preparation Time Before the Blow (PTBB), and Body Angle in Relation to the Center of Mass (BARCM). Results: Only one significant difference was found in the five phases of the spike technique in the two independent groups studied (Phase 4: p= 0.001), which had to do with the elbow angle in the ball hitting phase (a smaller average range in the youth group: 5.38). No other significant differences were found, though average ranges were smaller in the junior group in phases 1, 2, 3, and greater in the fifth phase (spine angle: 11.91). Additionally, significant differences were only found in TST (p= 0.033), and non-significant differences in the Preparation Time Before the Blow (PTBB: p= 0.717) and the Body Angle in Relation to the Center of Mass (BARCM: p= 0.717). Conclusions: Spine angles do not exert a significant influence on spike technique. However, elbow angles played a role in better elbow flexion and hand positioning, potentially generating a stronger impact on the ball and therefore greater difficulties for the opponent's defense(AU)

4.
Rev. cuba. invest. bioméd ; 36(4): 1-5, oct.-dic. 2017. ilus
Artigo em Espanhol | LILACS, CUMED | ID: biblio-1003917

RESUMO

Medical iRehab Shoulder Rotator Cuff es una aplicación móvil desarrollada por un médico deportivo y entrenador de atletismo, que proporciona muchos ejercicios y terapias con el objetivo de mejorar los procesos de rehabilitación tras lesiones del manguito de los rotadores. Estas lesiones son comunes en ciertos deportes como los de combate, la natación, el balonmano, el culturismo, los lanzamientos de atletismo, el rugby o el fútbol. El objetivo de este artículo de opinión es analizar la app Medical iRehab Shoulder Rotator Cuff, señalando sus posibles aplicaciones médicas, sus ventajas e inconvenientes, y sus detalles técnicos(AU)


Medical iRehab Shoulder Rotator Cuff is a mobile application developed by a sports doctor and athletic trainer, which provides many exercises and therapies with the aim of improving rehabilitation processes after rotator cuff injuries. These injuries are common in certain sports such as combat, swimming, handball, bodybuilding, athletic throwing, rugby or football. The objective of this article of opinion is to analyze the Medical iRehab Shoulder Rotator Cuff app, pointing out its possible medical applications, its advantages and disadvantages, and its technical details(AU)


Assuntos
Humanos , Esportes , Exercício Físico , Aplicativos Móveis/normas , Lesões do Manguito Rotador/reabilitação
7.
Sci Total Environ ; 584-585: 1212-1220, 2017 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-28169026

RESUMO

Fluorescence excitation emission matrix (FEEM) spectroscopy was used to evaluate its applicability as a tool to track dissolved organic matter (DOM) in a drinking water treatment plant (DWTP) that incorporates a conventional line (consisting in ozonation and GAC filtration) and a membrane-based line (consisting in ultrafiltration, reverse osmosis and mineralization) working in parallel. Seven sampling points within the different process stages were characterized monthly during 2014. A global Parallel Factor Analysis (PARAFAC) was used to pull out underlying organic fractions from the fluorescence spectra. Accordingly a five components model was selected to describe the system and the pros and cons of the model were discussed by analysis of the residuals. Among the five fluorescent components, those associated to humic-like matter (C1, C3 and C4) showed a similar season variability in the river water feeding the DWTP (which resembled that of UV254 and TOC), whereas the two components associated to protein-like matter (C2 and C5) exhibited a different behavior. The maximum fluorescence intensity values (Fmax) were used to quantify DOM removals across the plant. Compared to the conventional line, water from the UF/RO membrane-based line showed between 6 and 14 times lower fluorescence intensity signal for the humic-like components and between 1 and 3 for the protein-like components as compared to the conventional line. The differences in DOM composition due to seasonal variations and along the treatment trains point out the suitability of using fluorescence measurements over other parameters such as UV254 as a monitoring tool to help optimize operation conditions of each treatment stage and improve produced water quality in a DWTP.


Assuntos
Água Potável/análise , Espectrometria de Fluorescência , Qualidade da Água , Análise Fatorial , Substâncias Húmicas/análise , Compostos Orgânicos/análise , Purificação da Água
8.
Water Res ; 103: 256-263, 2016 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-27470468

RESUMO

Reverse osmosis (RO) membrane exposure to bisulphite, chlorite, bromide and iron(III) was assessed in terms of membrane composition, structure and performance. Membrane composition was determined by Rutherford backscattering spectrometry (RBS) and membrane performance was assessed by water and chloride permeation, using a modified version of the solution-diffusion model. Iron(III) dosage in presence of bisulphite led to an autooxidation of the latter, probably generating free radicals which damaged the membrane. It comprised a significant raise in chloride passage (chloride permeation coefficient increased 5.3-5.1 fold compared to the virgin membrane under the conditions studied) rapidly. No major differences in terms of water permeability and membrane composition were observed. Nevertheless, an increase in the size of the network pores, and a raise in the fraction of aggregate pores of the polyamide (PA) layer were identified, but no amide bond cleavage was observed. These structural changes were therefore, in accordance with the transport properties observed.


Assuntos
Brometos , Osmose , Filtração , Ferro , Membranas Artificiais , Purificação da Água
9.
Carbohydr Polym ; 147: 426-435, 2016 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-27178949

RESUMO

Over the 65-100°C range and at a water content of 1.6kgkg(-1)db, a comparison was conducted between plantain paste (dispersion made of flour and water) and pulp pieces after cooking to evaluate their respective degree of starch gelatinization (α) and in vitro digestibility. Below 76°C and at 100°C, the gelatinization behaviour of starch into pulp pieces and paste was similar, whereas at 85°C a significant mean relative difference was observed in between. For α in the 0-1 range, pieces of plantain pulp exhibited a lower rapidly digestible starch fraction (30%) and a higher resistant starch fraction (33%) than the flour paste, suggesting some structural effects. Both Weibull and exponential models showed a good fit for α over temperature range and starch digestibility fractions over α. Although no explicit relationship was established between the intact pulp structure and grinded flour state of plantain, the evaluation of the degree of starch gelatinization and digestibility of a plantain flour paste, could be used to predict the gelatinization and digestibility behaviour of plantain starch in entire pieces of pulp.


Assuntos
Temperatura Alta , Plantago/metabolismo , Amido/metabolismo , Culinária , Digestão
10.
Carbohydr Polym ; 118: 257-65, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25542132

RESUMO

The effect of temperature (T=55-120°C) and water content (X1=1.4-2.0 kg kg(-1) dry basis) on the gelatinization and digestibility of plantain flour (Dominico Harton genotype) were investigated. The degree of plantain starch gelatinization (α) was measured by DSC and modelled as a function of T and X1, using the Weibull model. Rapidly digestible starch (RDS) and resistant starch (RS) fractions were evaluated for different α values. An appropriate dimensionless variable was introduced to the analyzed and modelled RDS and RS as a function of α. Starch gelatinization begins at a temperature above 59.6 ± 0.5°C and α is strongly dependent on T in non-limiting water conditions. The combined effects of T and X1 on the RDS and RS can be explained by α. We demonstrate that various heat treatments and water contents lead to the same α, with the same RDS and RS values.


Assuntos
Plantago/química , Amido/química , Água/química , Valor Nutritivo , Temperatura
11.
Environ Technol ; 31(7): 799-814, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20586242

RESUMO

With the current increasing interest in aquifer denitrification, recent attention has been given to cost-effective in-situ treatments such as Enhanced In-Situ Biological Denitrification (EISBD), which intends to stimulate the indigenous bacterial activity by injecting an external organic substrate and/or nutrients to the aquifer matrix. Within this context, laboratory batch assays have been conducted to develop a strategy for in-situ denitrification of a nitrate-contaminated aquifer in Argentona, Catalonia (Spain). The assays were run under aerobic and anaerobic conditions at a temperature of 17 degrees C to better simulate the conditions of the aquifer. Acetate and glucose were added to assess their potential to promote heterotrophic denitrifying bacteria activity. Overall, the results revealed that indigenous micro-organisms had the potential of reducing nitrate under appropriate conditions. Nitrate removal was complete and faster under anaerobic conditions, though high nitrate removals were also attained under initial aerobic conditions when a readily organic compound was amended at a sufficient dosage. The results also revealed that a significant amount of the available organic carbon was consumed by processes other than denitrification, namely aerobic oxidation and other microbial oxidation processes. To sum up, the results of this study demonstrated that addition of organic compounds into the groundwater is a promising method for in-situ bioremediation of nitrate in the Argentona aquifer. This approach could potentially be applied to a number of situations in which nitrate concentration is elevated and where indigenous micro-organisms with potential to reduce nitrate are present within the aquifer material.


Assuntos
Acetatos/metabolismo , Bactérias Aeróbias/metabolismo , Glucose/metabolismo , Nitratos/metabolismo , Microbiologia da Água , Poluentes Químicos da Água/metabolismo , Purificação da Água/métodos , Biodegradação Ambiental , Nitratos/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação
12.
Environ Geochem Health ; 32(4): 373-8, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20387094

RESUMO

In this study, two mixtures of municipal compost, limestone and, optionally, zero-valent iron were assessed in two column experiments on acid mine treatment. The effluent solution was systematically analysed throughout the experiment and precipitates from both columns were withdrawn for scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffractometry analysis and, from the column containing zero-valent iron, solid digestion and sequential extraction analysis. The results showed that waters were cleaned of arsenic, metals and acidity, but chemical and morphological analysis suggested that metal removal was not due predominantly to biogenic sulphide generation but to pH increase, i.e. metal (oxy)hydroxide and carbonate precipitation. Retained arsenic and metal removal were clearly associated to co-precipitation with and/or sorption on iron and aluminum (oxy)hydroxides. An improvement on the arsenic removal efficiency was achieved when the filling mixture contained zero-valent iron. Values of arsenic concentrations were then always below 10 microg/L.


Assuntos
Arsênio/química , Carbonato de Cálcio/química , Compostos de Ferro/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Água/química , Arsênio/análise , Concentração de Íons de Hidrogênio , Mineração , Permeabilidade , Poluentes Químicos da Água/análise , Abastecimento de Água
13.
J Appl Microbiol ; 102(5): 1227-38, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17448158

RESUMO

AIMS: To investigate the distribution of a polymicrobial community of biodegradative bacteria in (i) soil and groundwater at a former manufactured gas plant (FMGP) site and (ii) in a novel SEquential REactive BARrier (SEREBAR) bioremediation process designed to bioremediate the contaminated groundwater. METHODS AND RESULTS: Culture-dependent and culture-independent analyses using denaturing gradient gel electrophoresis (DGGE) and polymerase chain reaction (PCR) for the detection of 16S ribosomal RNA gene and naphthalene dioxygenase (NDO) genes of free-living (planktonic groundwater) and attached (soil biofilm) samples from across the site and from the SEREBAR process was applied. Naphthalene arising from groundwater was effectively degraded early in the process and the microbiological analysis indicated a dominant role for Pseudomonas and Comamonas in its degradation. The microbial communities appeared highly complex and diverse across both the sites and in the SEREBAR process. An increased population of naphthalene degraders was associated with naphthalene removal. CONCLUSION: The distribution of micro-organisms in general and naphthalene degraders across the site was highly heterogeneous. Comparisons made between areas contaminated with polycyclic aromatic hydrocarbons (PAH) and those not contaminated, revealed differences in the microbial community profile. The likelihood of noncultured bacteria being dominant in mediating naphthalene removal was evident. SIGNIFICANCE AND IMPACT OF THE STUDY: This work further emphasizes the importance of both traditional and molecular-based tools in determining the microbial ecology of contaminated sites and highlights the role of noncultured bacteria in the process.


Assuntos
Bactérias/classificação , Ecossistema , Microbiologia do Solo , Poluentes do Solo/metabolismo , Microbiologia da Água , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Biodegradação Ambiental , Hidrocarbonetos Policíclicos Aromáticos , Reação em Cadeia da Polimerase
14.
Med Clin (Barc) ; 112(2): 51-4, 1999 Jan 23.
Artigo em Espanhol | MEDLINE | ID: mdl-10065429

RESUMO

BACKGROUND: Germline mutations in the BRCA1 gene have been associated with familial breast/ovarian cancer. Furthermore, women diagnosed of early-onset breast cancer have a higher probability of being carriers of BRCA1 mutations. Our aim was to know prevalence of BRCA1 mutations in women with breast cancer diagnosed before 40 years. PATIENTS AND METHODS: We analyzed genomic DNA samples of 159 women with early-onset breast cancer. Ten fragments of BRCA1 gene covering the 36% of cases with mutations described in the literature were screened. Analysis involved polymerase chain reaction (PCR), single-strand conformation polymorphisms (SSCP) and direct sequencing. RESULTS: Three germline BRCA1 mutations were identified, one of them not previously described. Two mutations were found in women with familial history of breast cancer. Five additional rare variants and polymorphisms were also detected. CONCLUSIONS: The absence of recurrent mutations or mutations detected in other countries, except for the 185delAG mutation, present in Ashkenazim population, shows the influence of ethnic and geographic origin of population studied, and illustrates the difficulties of establishing DNA-based screening tests for hereditary breast cancer.


Assuntos
Neoplasias da Mama/genética , Carcinoma Ductal de Mama/genética , Carcinoma Intraductal não Infiltrante/genética , Genes BRCA1/genética , Mutação em Linhagem Germinativa/genética , Adolescente , Adulto , DNA/sangue , DNA/genética , Feminino , Humanos , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Probabilidade , RNA/sangue , RNA/genética , Fatores de Risco , Espanha
15.
Tumour Biol ; 19(4): 222-8, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9679731

RESUMO

We used immunological methods to determine cytosolic and nuclear steroid receptors to evaluate the advantages of nuclear receptor measurement in the selection of breast cancer patients for treatment. Around 75% of tumors showed coincidence between nuclear and cytosolic receptors (+/+ or -/-) for estrogen receptor (ER) and for progesterone receptor (PgR). Only cytosolic receptors were detected in around 20% of tumors. Distributed in the ER/PgR phenotypes according to the nuclear or cytosolic receptors, 64% of tumors remained in the same subgroup, whereas 16% of tumors were classified as hormone dependent according to cytosolic and independent according to nuclear receptors, which could be considered as 'false-positive' results. 6% of tumors would be classified as negative according to cytosolic receptors but positive according to nuclear receptors and would correspond to 'false-negative' results by conventional methods. Cytosolic receptor results may overrate the hormone dependence and cause some 'misclassifications' of patients. This could partially explain the lack of response to therapy in some cases.


Assuntos
Neoplasias da Mama/classificação , Receptores de Estrogênio/análise , Receptores de Progesterona/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/química , Neoplasias da Mama/metabolismo , Núcleo Celular/química , Citosol/química , Feminino , Humanos , Menopausa , Pessoa de Meia-Idade
17.
Breast Cancer Res Treat ; 42(1): 83-6, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9116322

RESUMO

We measure EGF in saliva and plasma from 52 patients with active breast cancer, 22 breast cancer patients in follow-up (non-active) and 33 healthy women. EGF concentrations in saliva were significantly higher in patients with active and non-active breast cancer than healthy women, whereas the opposite results were found in plasma. The highest values of EGF in saliva were found in the local recurrence subgroup.


Assuntos
Neoplasias da Mama/sangue , Fator de Crescimento Epidérmico/análise , Saliva/química , Adulto , Idoso , Neoplasias da Mama/patologia , Fator de Crescimento Epidérmico/sangue , Feminino , Humanos , Pessoa de Meia-Idade , Metástase Neoplásica , Recidiva Local de Neoplasia
18.
Med Clin (Barc) ; 107(3): 90-2, 1996 Jun 15.
Artigo em Espanhol | MEDLINE | ID: mdl-8754494

RESUMO

BACKGROUND: We studied pS2 protein in breast tumors and its relation with estrogen and progesterone receptors and with anatomopathological characteristics of the tumors. MATERIAL AND METHODS: We measured the pS2 content (by IRMA) and steroid receptors content (by EIA) in 151 breast tumors. Results were compared and correlated with tumoral characteristics. RESULTS: 53% of tumors were pS2+. Among them, 91% were estrogen receptors +.86% of estrogen receptors negative tumors were pS2-. We observed correlation between pS2 and estrogen receptors values (r = 0.56; p < 0.0001) and between pS2 and progesterone receptors values (r = 0.53; p < 0.0001). Distributing the tumors in pS2+ and pS2-, we observed association between pS2+ and estrogen receptors + (chi 2 = 45.6; p < 0.0001) and pS2+ and progesterone receptors + (chi 2 = 43.1; p < 0.0001). However, we found a 18.5% of estrogen receptors + pS2- tumors. We observed a significant difference between GII and GIII tumoral grades (chi 2 = 5.51; p < 0.019), with a majority of pS2+ tumors in GII and pS2- tumors in GIII. CONCLUSIONS: The estrogen receptors in estrogen receptors + ps2- tumors may be non functional. The presence of pS2 protein alternative to that of progesterone receptors may indicate a functional heterogeneity of the estrogen receptors system, which is of interest in evaluating prognosis and response to the hormonal therapy.


Assuntos
Neoplasias da Mama/metabolismo , Estrogênios/biossíntese , Regulação Neoplásica da Expressão Gênica , Proteínas de Neoplasias/biossíntese , Proteínas , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Fator Trefoil-1 , Proteínas Supressoras de Tumor
20.
Eur J Clin Chem Clin Biochem ; 33(9): 563-8, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8611665

RESUMO

Results of epidermal growth factor (EGF) receptor in human breast tumours show large variations, mainly due to the lack of standardization of the assays. Our EGF receptor values are higher than those reported previously which may be due to the use of the hydroxyapatite to separate bound and non-bound ligand in a radioligand assay. We found EGF receptors in 58% (103/178) of the tumours (EGF receptor levels: 3 to 625 fmol/mg of membrane protein, mean = 33.3, median = 17.4), with a median Kd of 0.642 nmol/l. There was an inverse correlation between EGF receptors and estrogen receptors (r = -0.215, p = 0.00002, Kendall correlation). There was a difference between EGF receptor content in grade II (mean = 16.9) and grade III tumours (mean = 59.3) (p = 0.027), but not between histopathological types and lymph node status. The relevance of EGF receptor largely depends on the reliability of its determination. The standardized EORTC methodology is a reproducible alternative which will expand EGF receptor determination and permit comparability of data between laboratories.


Assuntos
Neoplasias da Mama/ultraestrutura , Durapatita , Receptores ErbB/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Axila , Sítios de Ligação , Neoplasias da Mama/patologia , Receptores ErbB/metabolismo , Feminino , Humanos , Radioisótopos do Iodo , Cinética , Linfonodos/patologia , Menopausa , Pessoa de Meia-Idade , Ensaio Radioligante/métodos , Receptores de Estrogênio/análise , Receptores de Progesterona/análise
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