Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
1.
Animal ; 17(12): 101032, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38035659

RESUMO

Problems associated with muddy pens have been identified as some of the most serious animal welfare issues related to outdoor feedlot beef production, but there is relatively little work examining the use of woodchip bedding for lot-fed beef cattle under conditions of cold, wet, but non-freezing winters on soil under-bases. This study examined the effects of graded levels of woodchip on the performance and behaviour of feedlot cattle housed in wet pen conditions. Bos taurus steers (n = 300; 379.1 ± 24.1 kg) were blocked by weight and breed and randomly assigned to 30 10-steer feedlot pens provided with either no woodchip bedding (Control, n = 10) manure interface only, or 15 cm depth of woodchip bedding (W15, n = 10) or 30 cm depth of woodchip bedding (W30, n = 10). The steers were housed in these treatment pens for 109 days on a feedlot ration, and the pens were irrigated so that approximately 74 mm of total precipitation (irrigation + natural rainfall) fell onto the pen surface every 30 days. Temperatures were mostly <20 °C maximum and -1 to 5 °C minimum. Steers were weighed on five occasions. Animal position and posture in pen were recorded once a week over an 8-hour day-time period. Carcase characteristics were measured, and adrenal gland weights were recorded. Providing woodchip bedding increased liveweight gain (P < 0.001) and gain:feed (G:F, P = 0.012) after day 28, increased DM intake (DMI) after day 92 (P = 0.049), and increased carcase weight (P = 0.001) and dressing percentage (P = 0.023). There was no additional benefit of W30 over W15 for liveweight gain or DMI, but the benefit of W15 for G:F was lower than that of W30 by the end of the feeding period (P = 0.012). There were no effects of bedding on other carcase quality traits. Steers in Control pens utilised the front of the pen for lying and standing more than the W15 and W30 steers (P < 0.001) suggesting the steers in the Control pens perceived the front of the pen as less aversive, potentially due to increased drainage compared to rest of the pen and proximity to feed bunk. Adrenal gland weight/kg and carcase weight tended to be higher in the Control treatment group than the W30 steers (P = 0.077). This research has demonstrated that for a 109-day feeding period in cold, wet conditions, steer performance and welfare can be improved by providing a minimum of 15 cm woodchip bedding.


Assuntos
Esterco , Aumento de Peso , Bovinos , Animais , Temperatura , Estações do Ano , Glândulas Suprarrenais , Ração Animal/análise , Dieta/veterinária
2.
J Anim Sci ; 1012023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-37392177

RESUMO

Stocking density may impact sheep welfare during live export voyages that occur under hot and humid conditions. The aim of this study was to assess the welfare implications for sheep housed at three allometric stocking densities (k = 0.030, 0.033, 0.042), while exposed to hot and humid climatic conditions. For 21 d, Merino wethers (n = 216) were housed in 12 pens of 18 wethers, in two climate-controlled rooms where wet-bulb temperature (TWB) mimicked the conditions of a live export voyage with high heat and humidity, and limited diurnal variation. Scan sampling of standing and lying behaviors was conducted on days 2, 5, 8, 11, 15, 18, and 20, at hourly intervals. Agonistic interactions were scored continuously on the same days between 1750 and 1800 h. Liveweights were recorded at the start and end of the study. For a subset of focal wethers (3 per pen), whole blood variables were assessed at the start and end of the experiment, along with fecal glucocorticoid metabolites (FGCM), which were also assessed on days 7 and 14. Rumen temperatures (TRUM) of focal wethers were recorded at 10-min intervals, and their respiration rates (RR) were measured every 2 h on days 1, 3, and from days 7 to 21. Focal wethers were slaughtered for necropsy after the study, and both adrenal glands were excised and weighed. The expression of some lying positions was impaired at high stocking densities, and lying with outstretched legs increased at high TWB. For respiration rates, there was an interaction between stocking density and TWB, such that RR was reduced by the provision of additional space at high TWB. TRUM was relatively unaffected by stocking density but increased at higher TWB, and any effects of stocking density on FGCM concentrations, liveweights (LW), adrenal gland weights or blood variables were minimal. Necropsy examination showed no indication that the wethers had experienced ongoing respiratory distress. These results suggest that the wethers were able to cope with these increases in stocking density under the conditions imposed. However, based on this evidence, the provision of additional space under hot conditions may be beneficial to facilitating the expression of some lying positions. Whilst the experiment was designed to emulate certain conditions relevant during live export voyages, other factors that may induce stress during this mode of transport were not present, and so the conclusions must be interpreted in the context of the experimental conditions.


There is a high demand for Australian sheep to be exported to the Middle East, and for live export voyages which depart during an Australian winter, heat, and humidity increase rapidly as ships cross the equator and approach destination countries. Concern about sheep becoming heat stressed during these voyages has increased, and industry attention has focused on the potential role of stocking density in determining heat stress risk in this context. High stocking densities limit the body surface area available for heat loss and can increase heat exchange between individual sheep. This study aimed to assess the welfare implications of three stocking densities, for sheep exposed to climatic conditions similar to those experienced during a live export voyage to the Middle East. Higher stocking densities restricted the ability of sheep to lie in some positions, but stocking density had limited effects on heat stress indicators or the physiology of the sheep. These results suggested that the sheep were able to cope with these increases in stocking density under the conditions imposed, but the conclusions must be interpreted in the context of the controlled experimental conditions.


Assuntos
Comportamento Alimentar , Temperatura Alta , Ovinos , Animais , Masculino , Comportamento Animal , Carneiro Doméstico , Umidade , Glucocorticoides
4.
Front Vet Sci ; 9: 965635, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36246333

RESUMO

Stocking density and trough space allowance can potentially impact sheep welfare during live export voyages. The aim of this study was to assess the welfare implications for sheep housed at five allometric stocking densities, with either unrestricted or restricted trough space allowance. Merino wethers (n = 720) were housed in 40 pens of 18 heads for 18 days. Two 5-min continuous focal animal observations (n = 3/pen) were conducted on days 3, 5, 11, and 17. Scan sampling of standing and lying behaviours were conducted on the same days at hourly intervals. Live weights and immune cell counts were quantified at the start and end of the experiment, as well as faecal glucocorticoid metabolites (FGCMs), which were also assessed on days 6 and 12. Focal animals housed at higher stocking densities spent less time lying during one of the continuous observation periods, but no important effects on the overall number of animals lying or on the synchronicity of lying were evident. The scan sampling results indicated that the expression of some preferred lying positions was impaired at high stocking densities, and that high stocking densities also resulted in increased agonistic social interactions and displacement events at the start of the trial. There was a slight reduction in day 18 live weights for animals housed at higher stocking densities, but FGCM concentrations and immune cell counts were essentially unaffected. Trough space had no important effects on day 18 live weight, FGCM concentrations, or immune cell counts, and had limited effects on sheep behaviour. The lack of important impacts on biological fitness traits suggests that the behavioural responses observed were sufficient in allowing sheep to cope with their environment. However, we provide evidence that the provision of additional space is beneficial in reducing the time it takes for animals to adapt to their environment and to facilitate the expression of some preferred lying positions. While designed to emulate certain conditions relevant during live export voyages, some factors that may induce stress during this mode of transport were not present such as heat and ocean swell, so the conclusions must be interpreted in the context of the experimental conditions.

5.
Sci Rep ; 10(1): 1581, 2020 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-32005953

RESUMO

Predicting the effects of invasive ecosystem engineering species in new bioregions has proved elusive. In part this is because separating biological effects from purely physical mechanisms has been little studied and yet could help predict potentially damaging bioinvasions. Here we tested the effects of a large bio-engineering fanworm Sabella spallanzanii (Sabella) versus worm-like structures (mimics) on gas and nutrient fluxes in a marine soft bottom sediment. Experimental plots of sediment in Hauraki Gulf (New Zealand) were used to test the hypothesis that ecosystem engineers negatively influence benthic ecosystem function through autogenic mechanisms, facilitating activity by biofouling organisms and competitive exclusion of native infauna. Enhanced physical structure associated with Sabella and mimics increased nitrogen fluxes, community metabolism and reduced denitrification from 23 µmol m-2 h-1 to zero at densities greater than 25 m2. Sabella plots on average had greater respiration (29%), NH4 release (33%), and greater NO3 release (52%) compared to mimics, suggesting allogenic (biological) mechanisms occur, but play a secondary role to autogenic (physical) mechanisms. The dominance of autogenic mechanisms indicates that bio-engineers are likely to cause significant impacts when established, regardless of fundamental differences in recipient regions or identity of the introduced bio-engineer. In the case of Sabella spallanzanii, compromised denitrification has the potential to tip the balance of net solute and gas exchanges and cause further ecological degradation in an already eutrophic system.


Assuntos
Biodegradação Ambiental , Bioengenharia/métodos , Incrustação Biológica , Ecossistema , Espécies Introduzidas , Nitrogênio/metabolismo , Animais , Organismos Aquáticos/metabolismo , Incrustação Biológica/prevenção & controle , Sedimentos Geológicos , Oceanos e Mares , Poliquetos/metabolismo
6.
Br J Gen Pract ; 67(655): e94-e102, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27919937

RESUMO

BACKGROUND: Symptoms of breathlessness, fatigue, and ankle swelling are common in general practice but deciding which patients are likely to have heart failure is challenging. AIM: To evaluate the performance of a clinical decision rule (CDR), with or without N-Terminal pro-B type natriuretic peptide (NT-proBNP) assay, for identifying heart failure. DESIGN AND SETTING: Prospective, observational, diagnostic validation study of patients aged >55 years, presenting with shortness of breath, lethargy, or ankle oedema, from 28 general practices in England. METHOD: The outcome was test performance of the CDR and natriuretic peptide test in determining a diagnosis of heart failure. The reference standard was an expert consensus panel of three cardiologists. RESULTS: Three hundred and four participants were recruited, with 104 (34.2%; 95% confidence interval [CI] = 28.9 to 39.8) having a confirmed diagnosis of heart failure. The CDR+NT-proBNP had a sensitivity of 90.4% (95% CI = 83.0 to 95.3) and specificity 45.5% (95% CI = 38.5 to 52.7). NT-proBNP level alone with a cut-off <400 pg/ml had sensitivity 76.9% (95% CI = 67.6 to 84.6) and specificity 91.5% (95% CI = 86.7 to 95.0). At the lower cut-off of NT-proBNP <125 pg/ml, sensitivity was 94.2% (95% CI = 87.9 to 97.9) and specificity 49.0% (95% CI = 41.9 to 56.1). CONCLUSION: At the low threshold of NT-proBNP <125 pg/ml, natriuretic peptide testing alone was better than a validated CDR+NT-proBNP in determining which patients presenting with symptoms went on to have a diagnosis of heart failure. The higher NT-proBNP threshold of 400 pg/ml may mean more than one in five patients with heart failure are not appropriately referred. Guideline natriuretic peptide thresholds may need to be revised.


Assuntos
Eletrocardiografia , Insuficiência Cardíaca/diagnóstico , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Atenção Primária à Saúde , Adulto , Idoso , Biomarcadores/sangue , Protocolos Clínicos , Dispneia , Inglaterra , Fadiga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Curva ROC , Encaminhamento e Consulta , Projetos de Pesquisa
7.
Cell Death Dis ; 4: e753, 2013 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-23907467

RESUMO

Prostate cancer may originate from distinct cell types, resulting in the heterogeneity of this disease. Galectin-3 (Gal-3) and androgen receptor (AR) have been reported to play important roles in the progression of prostate cancer, and their heterogeneous expressions might be associated with different cancer subtypes. Our study found that in various prostate cancer cell lines Gal-3 expression was always opposite to AR expression and other luminal cell markers but consistent with basal cell markers including glutathione S-transferase-π and Bcl-2. This expression pattern was confirmed in human prostate cancer tissues. Our results also showed that prostate cancer cells positive with basal cell markers were more aggressive. Downregulation of Gal-3 expression resulted in increased apoptotic potential and decreased metastasis potential of prostate cancer cells. Our findings demonstrate for the first time that Gal-3 may serve as a new marker for basal characteristics of prostate cancer epithelium. This study helps us to better understand the heterogeneity of prostate cancer. The clinical significance of this study lies in the application of Gal-3 to distinguish prostate cancer subtypes and improve treatment efficacy with designed personalized therapy.


Assuntos
Biomarcadores Tumorais/metabolismo , Galectina 3/metabolismo , Neoplasia de Células Basais/metabolismo , Neoplasias da Próstata/metabolismo , Animais , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Regulação para Baixo , Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Nus , Transplante de Neoplasias , Neoplasia de Células Basais/patologia , Neoplasias da Próstata/patologia , Receptores Androgênicos/metabolismo
8.
Br J Anaesth ; 111(3): 400-5, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23533253

RESUMO

BACKGROUND: Depth of anaesthesia (DOA) monitors based on the electroencephalogram (EEG) are commonly used in anaesthetic practice. Their technology relies on mathematical analysis of the EEG waveform, generally resulting in a number which corresponds to anaesthetic depth. We have created a novel method of interpreting the EEG, which retains its underlying complexity. This method consists of turning the EEG into a sound: the electroencephalophone (EEP). METHODS: In a pilot study, we recorded awake and anaesthetized EEGs from six patients. We transformed each EEG into an audio signal using a ring buffer with a write frequency of 1 kHz and a read frequency of 48 kHz, thus elevating all output frequencies by a factor of 48. In essence, the listener hears the previous 12 s of EEG data compressed into 250 ms, updated every 250 ms. From these data, we generated a bank of 5 s audio clips, which were then used to train and test a sample of 23 anaesthetists. RESULTS: After training, 21 of the 23 anaesthetists were able to use the EEP to correctly identify the conscious state of >5 of 10 randomly selected patients (P<0.001). The median score was 8 out of 10, with an inter-quartile range of 7-9. CONCLUSIONS: The EEP shows promise as a DOA monitor. However, extensive validation would be required in a variety of clinical settings before it could be accepted into mainstream clinical practice.


Assuntos
Acústica/instrumentação , Anestesia Geral/métodos , Eletroencefalografia/métodos , Monitorização Intraoperatória/instrumentação , Monitorização Intraoperatória/métodos , Vigília/efeitos dos fármacos , Adulto , Humanos , Projetos Piloto , Processamento de Sinais Assistido por Computador
9.
Free Radic Biol Med ; 58: 98-108, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23376469

RESUMO

Paraoxonase 2 (PON2), a member of a gene family that also includes PON1 and PON3, is expressed in most tissues, including the brain. In mouse brain, PON2 levels are highest in dopaminergic areas (e.g., striatum) and are higher in astrocytes than in neurons. PON2 is primarily located in mitochondria and exerts a potent antioxidant effect, protecting mouse CNS cells against oxidative stress. The aim of this study was to characterize PON2 expression and functions in the brains of male and female mice. Levels of PON2 (protein, mRNA, and lactonase activity) were higher in brain regions and cells of female mice. Astrocytes and neurons from male mice were significantly more sensitive (by 3- to 4-fold) to oxidative stress-induced toxicity than the same cells from female mice. Glutathione levels did not differ between genders. Importantly, no significant gender differences in susceptibility to the same oxidants were seen in cells from PON2(-/-) mice. Treatment with estradiol induced a time- and concentration-dependent increase in the levels of PON2 protein and mRNA in male (4.5-fold) and female (1.8-fold) astrocytes, which was dependent on activation of estrogen receptor-α. In ovariectomized mice, PON2 protein and mRNA were decreased to male levels in brain regions and in liver. Estradiol protected astrocytes from wild-type mice against oxidative stress-induced neurotoxicity, but did not protect cells from PON2(-/-) mice. These results suggest that PON2 is a novel major intracellular factor that protects CNS cells against oxidative stress and confers gender-dependent susceptibility to such stress. The lower expression of PON2 in males may have broad ramifications for susceptibility to diseases involving oxidative stress, including neurodegenerative diseases.


Assuntos
Arildialquilfosfatase/metabolismo , Encéfalo/metabolismo , Sistema Nervoso Central/patologia , Estresse Oxidativo , Animais , Astrócitos/metabolismo , Astrócitos/patologia , Encéfalo/patologia , Sistema Nervoso Central/metabolismo , Feminino , Predisposição Genética para Doença , Masculino , Camundongos , Neurônios/metabolismo , Neurônios/patologia , Caracteres Sexuais
10.
Qual Saf Health Care ; 18(2): 147-52, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19342531

RESUMO

INTRODUCTION: There are no validated measures available for use in assessing patients' views of the quality of primary care mental healthcare at practice level. METHODS: The Patient Experience Questionnaire was developed through an initial information-gathering phase with focus groups followed by questionnaire development and validation with patients in nine general practices in the West Midlands. Statistical analyses were performed to test the internal consistency, validity and reliability of the questionnaire. RESULTS: Fifty-six patients participated in focus groups, and 241 patients completed the questionnaire. The 20-item questionnaire had good internal consistency (Cronbach alpha = 0.94) and test-retest reliability (r = 0.859; p = 0.01). DISCUSSION: The Patient Experience Questionnaire appears to be a valid and reliable instrument, able to assess patients' views of the quality of primary care mental healthcare at practice level.


Assuntos
Transtornos Mentais/terapia , Serviços de Saúde Mental , Atenção Primária à Saúde , Qualidade da Assistência à Saúde , Inquéritos e Questionários , Análise Fatorial , Grupos Focais , Humanos , Masculino , Serviços de Saúde Mental/normas , Atenção Primária à Saúde/normas , Psicometria , Reprodutibilidade dos Testes
11.
Artigo em Inglês | MEDLINE | ID: mdl-19223021

RESUMO

Since the first report of their natriuretic effect on mammalian kidneys the relative influences of natriuretic peptides (NPs) on volume and salt regulation in vertebrates have been debated. As marine osmoconformers, with plasma ionic concentrations similar to seawater, the actions of NPs on hagfishes may provide information on their primordial role. A synthetic natriuretic peptide derived from Eptatretus burgeri (hNP) increased urine production rates in E. cirrhatus at 3x10(-8) M. It also contracted afferent branchial and segmental arteries at low concentrations (1x10(-10) M) and relaxed them at 3x10(-8) M. Thus, hNP has a renal effect and at higher concentrations causes vascular relaxation suggesting a role in volume regulation and the prevention of cardiac overloading. Rat ANP (rANP) stimulated sodium efflux from both isolated, perfused gill pouches and the whole animal. rANP also reduced subcutaneous sinus haematocrit relative to that in the ventral aorta, which is consistent with a vasodilatory role.


Assuntos
Feiticeiras (Peixe)/fisiologia , Peptídeos Natriuréticos/farmacologia , Micção/fisiologia , Vasodilatação/fisiologia , Animais , Relação Dose-Resposta a Droga , Ratos , Micção/efeitos dos fármacos , Vasoconstrição/efeitos dos fármacos , Vasoconstrição/fisiologia , Vasodilatação/efeitos dos fármacos
12.
Eur J Clin Nutr ; 63(7): 916-8, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19190668

RESUMO

The relation between zinc status and cognitive function was examined in a cross-sectional study in the Sidama area of Southern Ethiopia. Pregnant women >24 weeks of gestation from three adjacent rural villages volunteered to participate. Mean (s.d.) plasma zinc of 99 women was 6.97 (1.07) mumol/l (below the cutoff of 7.6 mumol/l indicative of zinc deficiency at this stage of gestation). The Raven's Coloured Progressive Matrices (CPM) test was administered individually. Scores for the Raven's scale A, which is the simplest scale, ranged from 4 to 10 of a possible 12. Women with plasma zinc <7.6 mumol/l had significantly lower Raven's CPM scale A scores than women with plasma zinc concentrations >7.6 mumol/l. Plasma zinc and maternal age and education predicted 17% of the variation in Raven's CPM scale A scores. We conclude that zinc deficiency is a major factor affecting cognition in these pregnant women.


Assuntos
Cognição , Complicações na Gravidez/psicologia , Oligoelementos/deficiência , Zinco/deficiência , Adulto , Estudos Transversais , Dieta , Escolaridade , Etiópia , Feminino , Humanos , Deficiências de Ferro , Idade Materna , Estado Nutricional , Gravidez , Complicações na Gravidez/sangue , Análise de Regressão , População Rural , Zinco/sangue
13.
Breast Cancer Res Treat ; 65(2): 101-10, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11261825

RESUMO

The MCF10 series of cell lines was derived from benign breast tissue from a woman with fibrocystic disease. The MCF10 human breast epithelial model system consists of mortal MCF10M and MCF10MS (mortal cells grown in serum-free and serum-containing media, respectively), immortalized but otherwise normal MCF10F and MCF10A lines (free-floating versus growth as attached cells), transformed MCF10AneoT cells transfected with T24 Ha-ras, and premalignant MCF10AT cells with potential for neoplastic progression. The MCF10AT, derived from xenograft-passaged MCF10-AneoT cells, generates carcinomas in approximately 25% of xenografts. We now report the derivation of fully malignant MCF10CA1 lines that complete the spectrum of progression from relatively normal breast epithelial cells to breast cancer cells capable of metastasis. MCF10CA1 lines display histologic variations ranging from undifferentiated carcinomas, sometimes with focal squamous differentiation, to well-differentiated adenocarcinomas. At least two metastasize to the lung following injection of cells into the tail vein; one line grows very rapidly in the lung, with animals moribund within 4 weeks, whereas the other requires 15 weeks to reach the same endpoint. In addition to variations in efficiency of tumor production, the MCF10CA1 lines show differences in morphology in culture, anchorage-independent growth, karyotype, and immunocytochemistry profiles. The MCF10 model provides a unique tool for the investigation of molecular changes during progression of human breast neoplasia and the generation of tumor heterogeneity on a common genetic background.


Assuntos
Neoplasias da Mama/patologia , Mama/citologia , Transformação Celular Neoplásica , Animais , Transformação Celular Neoplásica/genética , Feminino , Humanos , Cariotipagem , Camundongos , Transplante Heterólogo , Células Tumorais Cultivadas
14.
Cancer Res ; 61(4): 1320-6, 2001 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-11245428

RESUMO

Although growth factors and extracellular matrix (ECM) are recognized as important contributors to breast epithelial growth, morphogenesis, hormone responsiveness, and neoplastic progression, the influence of functional interactions between breast stromal and epithelial cells on these processes has not been defined. Using a novel three-dimensional cell-cell interaction model, we have compared the abilities of different mesenchymal cell types, including breast fibroblasts derived from reduction mammoplasty and tumor tissues, and human umbilical endothelial cells (HUVECs) to induce three-dimensional morphogenesis and growth of normal MCF10A and preneoplastic MCF10AT1-EIII8 (referred as EIII8) human breast epithelial cells. Our data demonstrate a requirement for organspecific fibroblasts in the induction of epithelial morphogenesis. Whereas inclusion of normal reduction mammoplasty fibroblasts inhibit or retard morphological conversion and growth of MCF10A and EIII8 cells, respectively, tumor-derived breast fibroblasts evoke ductal-alveolar morphogenesis of both MCF10A and EIII8 cells. The growth and morphogenesis inhibitory effects of normal fibroblasts remain even in the presence of estrogen because they are able to suppress the estrogen-induced growth of EIII8 cells, whereas tumor fibroblasts support and maintain estrogen responsiveness of EIII8 cells. The inductive morphogenic effects of tumor fibroblasts on EIII8 cells is further augmented by the inclusion of HUVECs because these cocultures undergo a dramatic increase in proliferation and branching ductal-alveolar morphogenesis that is accompanied by an increase in invasion, degradation of coincident ECM, and expression of MMP-9. Therefore, tumor fibroblasts confer morphogenic and mitogenic induction of epithelial cells, and further enhancement of growth and progression requires active angiogenesis. These data illustrate the importance of structural and functional interactions between breast stromal and epithelial cells in the regulation of breast epithelial growth and progression.


Assuntos
Neoplasias da Mama/patologia , Mama/citologia , Comunicação Celular/fisiologia , Mama/efeitos dos fármacos , Comunicação Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Técnicas de Cocultura , Inibição de Contato/efeitos dos fármacos , Inibição de Contato/fisiologia , Progressão da Doença , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Estradiol/farmacologia , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Humanos , Células Estromais/citologia , Células Estromais/efeitos dos fármacos
16.
J Submicrosc Cytol Pathol ; 32(1): 83-96, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10877106

RESUMO

Neoplastic progression is a prolonged and stepwise process, while tumor growth occurs after a series of molecular alterations that culminate in tumorigenesis. The phenotypic changes of transformation in breast carcinogenesis were studied through the use of scanning and transmission electron microscopy. MCF 10F, a spontaneously immortalized human breast epithelial cell line (Soule et al., 1990), was treated with 7,12 dimethylbenz(a)anthracene (DMBA) (Calaf and Russo, 1993) and then transfected with the c-Ha-ras oncogene (Calaf et al., 1995). Treated cells showed a progression in altered morphology, anchorage independency, invasiveness and tumorigenicity in the SCID. Scanning and transmission electron microscopy illustrated that the transformed cells could be distinguished from control cells by the expression of morphological characteristics such as loss of contact inhibition, irregular size and shape, emission of long filopodia and formation of stratified layers. In contrast, control cells showed uniform, flattened and polyhedrical cells, well closely juxtaposed to each other and joined by cytoplasmic interdigitations. Control cells also did not form colonies in agar-methocel, and were not invasive or tumorigenic in SCID mice. These studies showed the progression of breast carcinogenesis by phenotypical changes induced by the carcinogen and the insertion of the c-Ha-ras oncogene.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Mama/citologia , Transformação Celular Neoplásica , Células Epiteliais/citologia , Genes ras , 9,10-Dimetil-1,2-benzantraceno , Animais , Neoplasias da Mama/ultraestrutura , Células Epiteliais/ultraestrutura , Feminino , Humanos , Camundongos , Camundongos SCID , Microscopia Eletrônica de Varredura , Transfecção
17.
Cancer Res ; 60(2): 439-49, 2000 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-10667599

RESUMO

Although there is experimental evidence supporting the involvement of angiogenesis in the pathogenesis of breast cancer, the exact nature and effects of interaction between human breast epithelial cells (HBECs) and endothelial cells (ECs) have not been described thus far. This approach requires an assay system that permits growth and differentiation of both epithelial and endothelial cells. Here, we report the development of a three-dimensional in vitro culture system that supports growth and functional differentiation of preneoplastic HBECs and ECs and recapitulates estrogen-induced in vivo effects on angiogenesis and the proliferative potential of MCF10AT xenografts. MCF10A and MCF10AT1-EIII8 (referred to as EIII8) cell lines used in this study are normal or produce preneoplastic lesions, respectively. When MCF10A or EIII8 cells are seeded on reconstituted basement membrane (Matrigel), both lines organize into a three-dimensional tubular network of cells; however, tubes produced by EIII8 cells appear multicellular in contrast to unicellular structures formed by MCF10A cells. However, when MCF10A or EIII8 cells are cocultured with human umbilical vein endothelial cells (HUVECs) on Matrigel, rather than interacting with extracellular matrix, the ECs exhibit preferential adherence to epithelial cells. Although both MCF10A and EIII8 cells provide preferential substrate for EC attachment, only EIII8 cells facilitate sustained proliferation of ECs for prolonged periods that are visualized as "endothelial cell enriched spots," which express factor VIII-related antigen. At regions of endothelial-enriched spots, preneoplastic HBECs undergo branching ductal-alveolar morphogenesis that produce mucin, express cytokeratins, and proliferating cell nuclear antigen. The presence of actively proliferating and functional endothelial cells is essential for ductal-alveolar morphogenesis of preneoplastic HBECs because without ECs, the epithelial cells formed only tubular structures. This ability to establish functional ECs and ductal-alveolar morphogenesis is facilitated only by preneoplastic HBECs because normal MCF10A cells fail to elicit similar effects. Thus, a cause-effect relationship that is mutually beneficial exists between EC and preneoplastic HBECs that is critical for generation of functional vascular networks and local proliferative ductal alveolar outgrowths with invasive potential. Both these processes are augmented by estrogen, whereas antiestrogens inhibit these processes. Induction and maintenance of angiogenic phenotype is associated with up-regulation in expression of interleukin 8 and matrix metalloproteinase-2 and estrogen-induced increases in vascular endothelial growth factor and vascular endothelial growth factor receptor 2. This three-dimensional culture model offers a unique opportunity to study endothelial- and epithelial cell-specific factors that are important for ductal-alveolar morphogenesis, angiogenesis, and progression to malignant phenotype.


Assuntos
Neoplasias da Mama/patologia , Mama/patologia , Endotélio Vascular/citologia , Células Epiteliais/patologia , Estrogênios/farmacologia , Lesões Pré-Cancerosas/patologia , Membrana Basal , Mama/fisiopatologia , Neoplasias da Mama/fisiopatologia , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Colágeno , Meios de Cultivo Condicionados , Combinação de Medicamentos , Fatores de Crescimento Endotelial/biossíntese , Endotélio Vascular/fisiologia , Células Epiteliais/fisiologia , Feminino , Humanos , Hiperplasia , Interleucina-8/biossíntese , Queratinas/análise , Laminina , Linfocinas/biossíntese , Metaloproteinase 2 da Matriz/biossíntese , Mucinas/análise , Lesões Pré-Cancerosas/fisiopatologia , Antígeno Nuclear de Célula em Proliferação/análise , Proteoglicanas , Receptores Proteína Tirosina Quinases/biossíntese , Receptores de Fatores de Crescimento/biossíntese , Receptores de Fatores de Crescimento do Endotélio Vascular , Veias Umbilicais , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
18.
J Clin Endocrinol Metab ; 85(2): 837-46, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10690899

RESUMO

Extraglandular estrogen synthesis mediates the proliferation of estrogen-responsive breast cancer in postmenopausal women. Aromatase, the cytochrome P450 Cyp19 enzyme, catalyzes the rate-limiting step in estrogen biosynthesis. Activity is present in both normal and neoplastic breast tissue, and Cyp19 protein is localized by immunohistochemistry predominantly in breast stromal fibroblasts. In cultured breast stromal fibroblasts, both activity and Cyp19 messenger ribonucleic acid are increased to a substantial degree by hormonal and growth factor regulators of transcription. Transcriptional regulation of CYP19 is complex in breast tissues, in which exon switching in the usage of alternative first exons occurs from predominantly EI.4 in breast tissue from cancer-free women to predominantly EI.3 and PII in breast tumors and quadrants with or without tumor. The present study questioned whether the first exon switch occurs as a result of an inherent difference between fibroblasts in normal and tumor tissues or because of differences in local regulators between these tissues. To distinguish between these two possibilities, we examined fibroblasts cultured from breast tumor, benign breast, and reduction mammoplasty tissues for the ability of various CYP19 transcriptional regulators to modulate first exon EI.3, EI.4, and PII usage. A semiquantitative RT-PCR method was used to identify transcripts containing six of the nine known CYP19 first exons. Combinations of cAMP and Dex regulated transcription from first exons EI.3, EI.4, and PII in fibroblasts cultured from all tissues, but not in reduction mammoplasty epithelial cells. These results provide evidence that the fibroblasts from these breast tissues are not inherently different in transcriptional regulation of CYP19 first exon usage and that transcriptional regulatory molecules are likely to mediate the exon switch phenomenon.


Assuntos
Aromatase/genética , Mama/fisiopatologia , Fibroblastos/fisiologia , Transcrição Gênica/fisiologia , Mama/patologia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Células Cultivadas , Éxons/genética , Feminino , Genes de Troca/genética , Humanos , Valores de Referência , Células Estromais/fisiologia
19.
J Adv Nurs ; 29(5): 1221-7, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10320507

RESUMO

There is increasing interest in the use of stories to develop nursing and health care practice. This paper reports on how we used story to understand and develop research on nursing practice. Story (or narrative) and science can be seen as distinct but complementary paradigms. We have found that a story framework can help researchers to reflect on a process of social scientific investigation, and to consider how to 'go on' in that process. In a study on 'Community psychiatric nurses' empowerment of people with enduring mental disorders in the community: involving users to develop services' we have encountered a number of interesting and challenging issues related to design and use of methods. We present these issues within a framework of story analysis, focusing on issues related to empowerment. This analysis draws on Burke's 'pentad' of story elements as a framework for narrative analysis. We present the elements of the 'story of the study-as-funded' and as it was carried out through the pilot stage, and outline the story of developments in the main study. 'Trouble' in a story centres on a problematic 'ratio' of story elements. The 'trouble' at this stage in the progress of our study relates to lack of fit between some parts of the instruments (the methods) and the goal (empowerment), and to the status of the CPNs as actors or agents. Narrative analysis sensitizes us to these issues of 'trouble' and provides a means of addressing them. Like John Bunyan's Pilgrim, we have learned through our progress; unlike Pilgrim, we know not our end.


Assuntos
Serviços Comunitários de Saúde Mental , Pesquisa em Enfermagem , Enfermagem Psiquiátrica , Projetos de Pesquisa , Humanos , Pesquisa em Enfermagem/métodos , Enfermagem Psiquiátrica/métodos , Escócia
20.
J Psychiatr Ment Health Nurs ; 6(1): 53-60, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10336738

RESUMO

The discourse community of British psychiatric and mental health nursing is a contested realm. The 'Big Stories' of policy and planning of services are clearly articulated in disputes in journals, but the 'Little Stories' of nurses' work and patients' or users' experiences may be ignored or under-valued. This paper illustrates how the Big Story of a central theme in current policy--empowerment--is articulated in the realm of research funding and design, and how it is articulated by practitioners. The paper focuses attention on the responsibilities faced by researchers, in relating the Little Stories of practice and the Big Story of policy. It reports early and tentative findings from a study of community psychiatric nurses' empowerment of people with enduring mental disorders. The paper suggests ways in which strategies for analysis of qualitative data from interviews with CPNs may be informed by ideas drawn from the field of discourse analysis; reflexively examining how researchers' discourses relate to those of policy makers and mental health nursing practitioners. This paper is based on a presentation at the Network for Psychiatric Nursing Research Conference, Napier University, Edinburgh, 17 September 1997.


Assuntos
Enfermagem em Saúde Comunitária/organização & administração , Serviços Comunitários de Saúde Mental/organização & administração , Política de Saúde , Transtornos Mentais/enfermagem , Defesa do Paciente , Participação do Paciente , Poder Psicológico , Enfermagem Psiquiátrica/organização & administração , Atitude do Pessoal de Saúde , Participação da Comunidade , Humanos , Pesquisa Metodológica em Enfermagem , Recursos Humanos de Enfermagem/psicologia , Reino Unido
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...