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1.
Br J Dermatol ; 178(3): 749-760, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28815554

RESUMO

BACKGROUND: Striae gravidarum (SG), or stretch marks of pregnancy, begin as erythematous streaks and mature into hypopigmented atrophic bands. OBJECTIVES: In order to investigate molecular alterations that may promote atrophy of SG, we investigated dermal type I collagen fibrils, which provide human skin with support. METHODS: We obtained skin samples of recently developed, erythematous abdominal SG from pregnant women. To examine the organization of collagen fibrils, second-harmonic generation imaging was performed using multiphoton microscopy. Immunostaining was used to determine protein expression and localization of type I procollagen, the precursor of type I collagen fibrils. Real-time polymerase chain reaction was used to determine gene expression levels. RESULTS: In control (hip) and stretched normal-appearing perilesional abdominal skin, dermal collagen fibrils were organized as tightly packed, interwoven bundles. In SG, collagen bundles appeared markedly separated, especially in the mid-to-deep dermis. In the spaces separating these bundles, loosely packed wavy collagen fibrils lacking organization as bundles were present. These disorganized fibrils persisted into the postpartum period and failed to form densely packed bundles. Numerous large fibroblasts displaying type I procollagen expression were in close proximity to the disorganized fibrils, suggesting that the fibrils are newly synthesized. Supporting this possibility, immunostaining and gene expression of type I procollagen were increased throughout the dermis of SG. CONCLUSIONS: Early SG display marked separation of collagen bundles and emergence of disorganized collagen fibrils that fail to form bundles. These alterations may reflect ineffective repair of collagen bundles disrupted by intense skin stretching. Persistent disruption of the collagenous extracellular matrix likely promotes formation and atrophy of SG.


Assuntos
Doenças do Colágeno/patologia , Complicações na Gravidez/patologia , Estrias de Distensão/patologia , Estudos de Casos e Controles , Doenças do Colágeno/metabolismo , Colágeno Tipo I/metabolismo , Feminino , Colágenos Fibrilares/fisiologia , Fibroblastos/metabolismo , Humanos , Gravidez , Complicações na Gravidez/metabolismo , Pró-Colágeno/biossíntese , Pele/irrigação sanguínea , Estrias de Distensão/metabolismo , Adulto Jovem
2.
Ann Oncol ; 28(6): 1316-1324, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29177434

RESUMO

BACKGROUND: Approximately 5%-10% of gastric cancers have a fibroblast growth factor receptor-2 (FGFR2) gene amplification. AZD4547 is a selective FGFR-1, 2, 3 tyrosine kinase inhibitor with potent preclinical activity in FGFR2 amplified gastric adenocarcinoma SNU16 and SGC083 xenograft models. The randomized phase II SHINE study (NCT01457846) investigated whether AZD4547 improves clinical outcome versus paclitaxel as second-line treatment in patients with advanced gastric adenocarcinoma displaying FGFR2 polysomy or gene amplification detected by fluorescence in situ hybridization. PATIENTS AND METHODS: Patients were randomized 3:2 (FGFR2 gene amplification) or 1:1 (FGFR2 polysomy) to AZD4547 or paclitaxel. Patients received AZD4547 80 mg twice daily, orally, on a 2 weeks on/1 week off schedule of a 21-day cycle or intravenous paclitaxel 80 mg/m2 administered weekly on days 1, 8, and 15 of a 28-day cycle. The primary end point was progression-free survival (PFS). Safety outcomes were assessed and an exploratory biomarker analysis was undertaken. RESULTS: Of 71 patients randomized (AZD4547 n = 41, paclitaxel n = 30), 67 received study treatment (AZD4547 n = 40, paclitaxel n = 27). Among all randomized patients, median PFS was 1.8 months with AZD4547 and 3.5 months with paclitaxel (one-sided P = 0.9581); median follow-up duration for PFS was 1.77 and 2.12 months, respectively. The incidence of adverse events was similar in both treatment arms. Exploratory biomarker analyses revealed marked intratumor heterogeneity of FGFR2 amplification and poor concordance between amplification/polysomy and FGFR2 mRNA expression. CONCLUSIONS: AZD4547 did not significantly improve PFS versus paclitaxel in gastric cancer FGFR2 amplification/polysomy patients. Considerable intratumor heterogeneity for FGFR2 gene amplification and poor concordance between FGFR2 amplification/polysomy and FGFR2 expression indicates the need for alternative predictive biomarker testing. AZD4547 was generally well tolerated.


Assuntos
Adenocarcinoma/tratamento farmacológico , Antineoplásicos/administração & dosagem , Benzamidas/administração & dosagem , Paclitaxel/administração & dosagem , Piperazinas/administração & dosagem , Pirazóis/administração & dosagem , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética , Neoplasias Gástricas/tratamento farmacológico , Adenocarcinoma/genética , Antineoplásicos/efeitos adversos , Benzamidas/efeitos adversos , Linhagem Celular Tumoral , Intervalo Livre de Doença , Amplificação de Genes , Humanos , Paclitaxel/efeitos adversos , Piperazinas/efeitos adversos , Pirazóis/efeitos adversos , Neoplasias Gástricas/genética
3.
Soc Sci Med ; 177: 27-34, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28157566

RESUMO

Housing is a significant determinant of health and substandard housing is a public health issue. East London has long had a shortage of social and affordable housing, worsened in recent years by a combination of stressors. In one of East London's most deprived boroughs, Newham, changes brought about by the 2011 Localism Act and the unique demands of being the host Olympic borough in 2012 have brought considerable pressures to bear on social infrastructure. This paper examines how these pressures were experienced by local residents via their narratives of social housing and health. The data reported here are from a qualitative study comprising two waves of data collection. Narrative family interviews and go-along interviews were conducted with 40 Newham residents at wave one and 28 at wave two. A narrative analysis with a Bakhtinian interpretation was undertaken. This revealed that residents framed experiences of social housing in terms of an inherent system-level ideology based on notions of need and waiting. A particularly striking feature of this ideology was the extent to which descriptions of ill health and impairment were implicated in constructions of housing need; participants directly attributed a range of health complaints to their housing predicaments, including stress, depression, cancer scares, panic attacks and loss of sleep. Understanding the contested ideology of social housing can illuminate both the dynamic processes of social exclusion and the ways in which its subjects seek to resist it.


Assuntos
Nível de Saúde , Habitação/tendências , Narração , Percepção , Adulto , Feminino , Humanos , Renda/tendências , Londres/etnologia , Masculino , Pessoa de Meia-Idade , Pesquisa Qualitativa , Grupos Raciais/psicologia , Grupos Raciais/estatística & dados numéricos , Fatores Sexuais , Fatores Sociológicos
4.
Health Place ; 36: 18-24, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26340644

RESUMO

Mega-sporting event regeneration, as a specific approach to urban renewal, uses impending host-city status as a catalyst for revitalisation and has the potential to improve health both through addressing deprivation and by promoting increased sport and physical activity among the host-city's population. This qualitative study explored how hosting of the London 2012 Games impacted upon the way East London residents perceived and experienced the social determinants of health in their local neighbourhood. We conducted narrative family interviews, go-along interviews and video focus group workshops with 66 Newham residents, aged 12-55 years, immediately after the Games. A narrative analytic approach examined accounts of health and wellbeing experiences in terms of neighbourhood change and the spectacle of the Games. Participants of this qualitative study generally welcomed the respite and the unexpected chance to live in a cleaner, safer and more unified environment. However, this positivity was underscored by an acute awareness that this was a very temporary situation and one that was intended to support the event rather than residents.


Assuntos
Aniversários e Eventos Especiais , Determinantes Sociais da Saúde , Esportes , Reforma Urbana , Adulto , Feminino , Humanos , Entrevistas como Assunto , Londres , Masculino , Pessoa de Meia-Idade , Pesquisa Qualitativa , Adulto Jovem
5.
Br J Dermatol ; 173(6): 1420-30, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26179468

RESUMO

BACKGROUND: Striae gravidarum (SG), or 'stretch marks' of pregnancy, begin as erythematous streaks, and mature over months to years to become permanent scar-like bands that may be hypopigmented, atrophic and lax. OBJECTIVES: To investigate early molecular alterations that may promote laxity of mature SG, we investigated the dermal elastic fibre network, which provides human skin with elastic properties. METHODS: We obtained skin samples of newly developed, erythematous abdominal SG in healthy pregnant women. The elastic fibre network was examined by Verhoeff elastic staining and immunofluorescence staining of skin sections. Gene expression was measured by real-time polymerase chain reaction. RESULTS: The normal elastic fibre network appeared markedly disrupted in SG, compared with perilesional abdominal skin or control (normal-appearing hip skin). This disruption was accompanied by the emergence of short, disorganized, thin, thread-like 'fibrils', which were observed prominently in the mid-to-deep dermis. These fibrils were rich in tropoelastin (the main component of normal elastic fibres), and persisted into the postpartum period without forming normal-appearing elastic fibres. The emergence of these fibrils was accompanied by increased gene expression of tropoelastin and fibrillin-1, but not other elastic fibre components, including fibrillin-2 and fibulin-1, -2 or -5. CONCLUSIONS: In early SG, the elastic fibre network appears markedly disrupted, and newly synthesized tropoelastin-rich fibrils emerge, likely as a result of uncoordinated synthesis of elastic fibre components. Because they are thin and disorganized, tropoelastin-rich fibrils likely do not function as normal elastic fibres do. These observations provide the foundations for elucidating pathogenic mechanisms by which laxity may develop in SG.


Assuntos
Tecido Elástico/patologia , Estrias de Distensão/patologia , Doenças do Colágeno/patologia , Tecido Elástico/metabolismo , Feminino , Humanos , Gravidez , Transtornos Puerperais/metabolismo , Transtornos Puerperais/patologia , Estrias de Distensão/metabolismo , Tropoelastina/metabolismo , Adulto Jovem
6.
Oncogene ; 32(37): 4406-16, 2013 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-23108397

RESUMO

αvß6 integrin expression is upregulated on a wide range of epithelial tumours, and is thought to play a role in modulating tumour growth. Here we describe a human therapeutic antibody 264RAD, which binds and inhibits αvß6 integrin function. 264RAD cross-reacts with human, mouse and cynomolgus monkey αvß6, and inhibits binding to all ligands including the latency-associated peptide of TGF-ß. Screening across a range of integrins revealed that 264RAD also binds and inhibits the related integrin αvß8, but not the integrins α5ß1, αvß3, αvß5 and α4ß1. In vitro 264RAD inhibited invasion of VB6 and Detroit 562 cells in a Matrigel invasion assay and αvß6 mediated production of matrix metalloproteinase-9 in Calu-3 cells. It inhibited TGF-ß-mediated activation of dermal skin fibroblasts by preventing local activation of TGF-ß by NCI-H358 tumour cells in a tumour cell-fibroblast co-culture assay. In vivo 264RAD showed dose-dependent inhibition of Detroit 562 tumour growth, regressing established tumours when dosed at 20 mg/kg once weekly. The reduction in growth associated with 264RAD was related to a dose-dependent inhibition of Ki67 and phospho-ERK and a reduction of αvß6 expression in the tumour cells, coupled to a reduction in fibronectin and alpha smooth muscle actin expression in stromal fibroblasts. 264RAD also reduced the growth and metastasis of orthotopic 4T1 tumours. At 20 mg/kg growth of both the primary tumour and the number of metastatic deposits in lung were reduced. The data support the conclusion that 264RAD is a potent inhibitor of αvß6 integrin, with some activity against αvß8 integrin, that reduces both tumour growth and metastasis.


Assuntos
Anticorpos Monoclonais Humanizados/farmacologia , Integrinas/antagonistas & inibidores , Animais , Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Monoclonais Humanizados/metabolismo , Antígenos de Neoplasias/imunologia , Antígenos de Neoplasias/metabolismo , Biomarcadores/metabolismo , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Técnicas de Cocultura , Feminino , Humanos , Integrinas/imunologia , Integrinas/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/secundário , Macaca fascicularis , Metaloproteinase 9 da Matriz/biossíntese , Camundongos , Neoplasias/metabolismo , Neoplasias/patologia , Ligação Proteica , Fator de Crescimento Transformador beta/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Am J Transplant ; 10(11): 2421-30, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20977633

RESUMO

Ischemia/reperfusion injury and delayed graft function (DGF) following organ transplantation adversely affect graft function and survival. A large animal model has not been characterized. We developed a pig kidney allograft model of DGF and evaluated the cytoprotective effects of inhaled carbon monoxide (CO). We demonstrate that donor warm ischemia time is a critical determinant of DGF as evidenced by a transient (4-6 days) increase in serum creatinine and blood urea nitrogen following transplantation before returning to baseline. CO administered to recipients intraoperatively for 1 h restored kidney function more rapidly versus air-treated controls. CO reduced acute tubular necrosis, apoptosis, tissue factor expression and P-selectin expression and enhanced proliferative repair as measured by phosphorylation of retinol binding protein and histone H3. Gene microarray analyses with confirmatory PCR of biopsy specimens showed that CO blocked proinflammatory gene expression of MCP-1 and heat shock proteins. In vitro in pig renal epithelial cells, CO blocks anoxia-reoxygenation-induced cell death while promoting proliferation. This large animal model of DGF can be utilized for testing therapeutic strategies to reduce or prevent DGF in humans. The efficacy of CO on improving graft function posttransplant validates the model and offers a potentially important therapeutic strategy to improve transplant outcomes.


Assuntos
Monóxido de Carbono/uso terapêutico , Função Retardada do Enxerto/tratamento farmacológico , Transplante de Rim/fisiologia , Animais , Monóxido de Carbono/farmacocinética , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Perfilação da Expressão Gênica , Rejeição de Enxerto/prevenção & controle , Rim/metabolismo , Necrose Tubular Aguda/etiologia , Necrose Tubular Aguda/imunologia , Traumatismo por Reperfusão/prevenção & controle , Suínos , Tacrolimo/farmacocinética
8.
J Epidemiol Community Health ; 63(3): 253-8, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19074925

RESUMO

BACKGROUND: Previous research strongly suggests that ethnic minority groups are more likely to suffer a poorer health profile compared with the overall population, although it is not clear whether these inequalities persist over generations. This study aimed to establish the degree to which ethnic inequalities in health are transmitted from the first to the second generation, and to determine the extent to which intergenerational changes in socioeconomic status and health behaviours might explain any variation that exists. METHODS: Data from the 1999 and 2004 Health Surveys for England assessed the prevalence of fair/poor general health across first (n = 4492) and second (n = 5729) generations of six ethnic minority populations. A white population was selected as reference (n = 18 407). The risk of fair/poor general health was estimated by applying logistic regression models and stepwise inclusion of demographic, socioeconomic and behavioural variables. Generational movement relative to the white baseline was assessed for all ethnic groups adjusted for age and sex. RESULTS: No significant differences in levels of reported fair/poor general health were observed between generations. After adjusting for improved socioeconomic position, the second generation became more likely to report worse health, whereas adjusting for differences in health behaviours had no effect. The Bangladeshi population showed significant intergenerational improvement in general health relative to the white reference, showing a reduction in the odds ratio (95% CI) from 2.75 (2.14 to 3.56) for the first generation to 1.58 (1.17 to 2.13) in the second generation. CONCLUSION: Ethnic minorities in England report consistent rates of fair/poor general health across generations, despite the health benefits resulting from upward social mobility. These health inequalities are unaffected by changes in health behaviours. Understanding these intergenerational pathways will have important public health policy implications as the migrant population not only ages, but also reproduces.


Assuntos
Etnicidade/estatística & dados numéricos , Disparidades nos Níveis de Saúde , Grupos Minoritários/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Escolaridade , Inglaterra , Saúde da Família , Feminino , Comportamentos Relacionados com a Saúde , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Classe Social , Mobilidade Social/estatística & dados numéricos , Fatores Socioeconômicos , Adulto Jovem
9.
J Orthod ; 34(3): 173-5, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17761800

RESUMO

A method of controlled movement of teeth using open and closed coil spring. A 'clinical pearl' describing an original clinical technique to prevent uncontrolled tooth movement while using an active coil spring on the archwire.


Assuntos
Fios Ortodônticos , Técnicas de Movimentação Dentária/instrumentação , Análise do Estresse Dentário , Humanos , Desenho de Aparelho Ortodôntico
10.
Carcinogenesis ; 27(10): 2133-9, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16782971

RESUMO

The Apc(Min/+) mouse model is a clinically relevant model of early intestinal cancer. We used AZD2171, an oral, highly potent and selective vascular endothelial growth factor (VEGF) signaling inhibitor, to investigate the role of VEGF receptor-2 (VEGFR-2) signaling in adenoma development and growth in Apc(Min/+) mice. AZD2171 (5 mg/kg body wt/day) was administered once daily for 28 days to 6-week-old (early-intervention) or 10-week-old (late intervention) mice. In the early-intervention study, AZD2171 reduced the number of macroscopic polyps in the small bowel and colon. Macropolyp diameter was lower in the small bowel, but remained unchanged in the colon. In animals receiving AZD2171, microscopic evaluation of the small intestine showed a significant reduction in the number of larger lesions. In the late-intervention study, AZD2171 treatment reduced macropolyp diameter (but not number) in the small intestine. Microscopic analysis revealed that AZD2171 significantly reduced the number of larger micropolyps in the small bowel, with no large micropolyps present in the colon. AZD2171 treatment had no effect on microvessel density or localization of beta-catenin staining in adenomas or non-tumor intestinal tissue, but significantly reduced the number of cells expressing VEGFR-2 mRNA. In conclusion, the effects of AZD2171 in the small intestine of Apc(Min/+) mice are consistent with an antiangiogenic mechanism of action, limiting growth of adenomas to < or =1 mm. These data also suggest that an early step in adenoma development may depend on VEGFR-2 signaling. Together, these results indicate that VEGFR-2 signaling may play key roles in the development and progression of intestinal adenomas.


Assuntos
Adenoma/prevenção & controle , Genes APC/fisiologia , Neoplasias Intestinais/prevenção & controle , Pólipos Intestinais/tratamento farmacológico , Quinazolinas/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/análise , Esplenomegalia/prevenção & controle , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética
12.
Connect Tissue Res ; 42(1): 59-69, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11696989

RESUMO

Cartilage formation during embryonic development and in fracture healing in adult animals involves chondrogenic differentiation of mesenchymal precursors. Here we describe an in vitro model whereby human dermal fibroblasts, considered to be restricted to a fibroblast lineage, are apparently redirected toward a chondrogenic phenotype by high density micromass culture in the presence of lactic acid. Micromass cultures treated with 40 mM lactate exhibited increased levels of Alcian blue staining and sulfate incorporation, indicative of elevated sulfated glycosaminoglycan synthesis. Northern analysis revealed an up-regulation of chondroitin sulfate proteoglycan 1 (aggrecan) and transforming growth factor-beta 1 mRNA and a decrease in type I collagen expression. Type II collagen was detected by reverse transcription-PCR only in experimental cultures. Although the observed changes in biosynthesis and gene expression were consistent with differentiating chondrocytes, the cells displayed an elongated, fibroblast-like morphology. These findings suggest that dermal fibroblasts may be committed to differentiate along a chondrogenic pathway by in vitro culture under specific forcing conditions.


Assuntos
Colágeno Tipo II/genética , Colágeno Tipo I/genética , Proteínas da Matriz Extracelular , Fibroblastos/efeitos dos fármacos , Regulação da Expressão Gênica , Ácido Láctico/farmacologia , Proteoglicanas/genética , Agrecanas , Contagem de Células , Diferenciação Celular , Células Cultivadas , Derme/citologia , Fibroblastos/citologia , Fibroblastos/metabolismo , Perfilação da Expressão Gênica , Humanos , Lectinas Tipo C , Fenótipo , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta1
13.
J Morphol ; 246(3): 192-7, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11077431

RESUMO

Ice worms occupy a unique position in metazoan phylogeny in that they are the only known annelid that completes its life cycle in ice. The mechanism(s) associated with this adaptation are likely to occur at different levels, ranging from modification of their metabolism to changes in morphology. In this study, we examined specimens of Mesenchytraeus solifugus by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) in an effort to identify morphologic structures that may aid in its glacial habitation. We report that M. solifugus contains an elongated head pore at the tip of its prostomium, numerous sensory structures, and differentially oriented setae that curve abruptly at their distal end.


Assuntos
Anelídeos/ultraestrutura , Alaska , Animais , Cabeça , Gelo , Órgãos dos Sentidos/ultraestrutura
14.
FEBS Lett ; 468(2-3): 109-14, 2000 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-10692568

RESUMO

Pseudogenes are commonly encountered during investigation of the genomes of a wide range of life forms. This review concentrates on vertebrate, and in particular mammalian, pseudogenes and describes their origin and subsequent evolution. Consideration is also given to pseudogenes that are transcribed and to the unusual group of genes that exist at the interface between functional genes and non-functional pseudogenes. As the sequences of different genomes are characterised, the recognition and interpretation of pseudogene sequences will become more important and have a greater impact in the field of molecular genetics.


Assuntos
Pseudogenes , Vertebrados/genética , Animais , Evolução Molecular , Genoma Humano , Humanos , Retroelementos
16.
Nucleic Acids Res ; 25(17): 3552-4, 1997 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-9254719

RESUMO

A band extracted from a differential display polyacrylamide gel often represents a composite of heterogeneous products. We have developed a non- radioactive method to simply and rapidly analyse its complexity. A fluorescent restriction enzyme fingerprint of the composite mixture is generated. The number of individual bands observed in this fingerprint indicates the complexity of the re-amplified cDNA mixture. Restriction fingerprints of the inserts of cDNA subclones derived from the re-amplified cDNA mixture are compared to the composite fingerprint to select those representing the most intense bands in the composite. This dramatically reduces the number of clones required for further characterisation.


Assuntos
DNA Complementar/análise , Eletroforese em Gel de Poliacrilamida , Reação em Cadeia da Polimerase , DNA Polimerase Dirigida por RNA , Sequência de Bases , Impressões Digitais de DNA , Enzimas de Restrição do DNA , DNA Complementar/química , Fluoresceínas , Corantes Fluorescentes , Dados de Sequência Molecular
17.
Biotechniques ; 23(2): 274-9, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9266082

RESUMO

We have modified the automated differential display reverse transcription polymerase chain reaction technique (DDRT-PCR) such that a single fluorescently labeled universal primer (d(F)CTCACG-GATCCGTCGATTTT) is used in all PCRs together with a selection of arbitrary primers. We term this fluorescent detection procedure FDDRT-PCR. Anchoring primers of general structure dTGGTCTCACGGATCCTCGA-(T)12 VN (where N can be any deoxynucleoside and V can be any deoxynucleoside other than thymidine) are used for the RT step, and the universal primer together with selected arbitrary primers are then used for the PCR amplification. Advantages of this approach are: (i) the fluorescently labeled universal primer is a constant feature in every PCR, so that changes in banding profile are highly likely to reflect the incorporation of different arbitrary 10-mer primers; (ii) artifacts that result from arbitrary 10-mer to arbitrary 10-mer primer amplifications are not observed by fluoresence detection on an automated gene scanner because such products are not fluorescently labeled; (iii) sample throughput and ease of data handling are increased when compared with the conventional radioactive/manual approach and (iv) using a single fluorescently labeled primer in all PCRs is highly cost-effective.


Assuntos
Primers do DNA , Corantes Fluorescentes , Reação em Cadeia da Polimerase/métodos , Análise de Sequência de DNA/métodos , Autorradiografia , Sequência de Bases , DNA Complementar/análise , Reação em Cadeia da Polimerase/normas
18.
Hum Mol Genet ; 6(2): 285-9, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9063749

RESUMO

Most multiple case families of young onset breast cancer and ovarian cancer are thought to be due to highly penetrant mutations in the predisposing genes BRCA1 and BRCA2. However, these mutations are uncommon in the population and they probably account for only a few percent of all breast cancer incidence. A much larger fraction of breast cancer might, in principle, be due to common variants which confer more modest individual risks. There are several common polymorphisms in the BRCA1 gene which generate amino acid substitutions. We have examined the frequency of four of these polymorphisms: Gln356Arg, Pro871Leu, Glu1038Gly and Ser1613Gly in large series of breast and ovarian cancer cases and matched controls. Due to strong linkage disequilibrium, these four sites generate only three haplotypes with a frequency > 1.3%. The most common haplotypes, defined by the alleles Gln356Pro871Glu1038Ser1613 and Gln356Leu871Gly1038Gly1613, have frequencies of 0.57 and 0.32 respectively, and these frequencies do not differ significantly between patient and control groups. Thus the most common polymorphisms of the BRCA1 gene do not make a significant contribution to breast or ovarian cancer risk. However, our data suggest that the Arg356 allele may have a different genotype distribution in breast cancer patients from that in controls (Arg356 homozygotes are more frequent in the control groups, P = 0.01), indicating that it may be protective against breast cancer. If this finding can be confirmed, it may provide an insight into the structural features of the BRCA1 protein that are important for its function.


Assuntos
Proteína BRCA1/genética , Neoplasias da Mama/genética , Variação Genética , Neoplasias Ovarianas/genética , Adulto , Idoso , Alelos , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Pessoa de Meia-Idade
19.
Biol Trace Elem Res ; 52(3): 209-25, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8811279

RESUMO

The bioavailability of selenium (Se) was determined in bacterial strains that reduce selenite to red elemental Se (SeO). A laboratory strain of Bacillus subtilis and a bacterial rod isolated from soil in the vicinity of the Kesterson Reservoir, San Joaquin Valley, CA, (Microbacterium arborescens) were cultured in the presence of 1 mM sodium selenite (Na2SeO3). After harvest, the washed, lyophilized B. Subtilis and M. arborescens samples contained 2.62 and 4.23% total Se, respectively, which was shown to consist, within error, entirely of SeO. These preparations were fed to chicks as supplements to a low-Se, vitamin E-free diet. Three experiments showed that the Se in both bacteria had bioavailabilities of approx 2% that of selenite. A fourth experiment revealed that gray SeO had a bioavailability of 2% of selenite, but that the bioavailability of red SeO depended on the way it was prepared (by reduction of selenite). When glutathione was the reductant, bioavailability resembled that of gray SeO and bacterial Se; when ascorbate was the reductant, bioavailability was twice that level (3-4%). These findings suggest that aerobic bacteria such as B. subtilis and M. arborescens may be useful for the bioremediation of Se-contaminated sites, i.e., by converting selenite to a form of Se with very low bioavailability.


Assuntos
Selênio/sangue , Selenito de Sódio/metabolismo , Animais , Bacillus subtilis/metabolismo , Disponibilidade Biológica , Galinhas , Meios de Cultura , Glutationa Peroxidase/metabolismo , Glutationa Redutase/química , Hidrólise , Masculino , Microscopia Eletrônica de Varredura , Oxirredução , Selênio/farmacocinética , Selenito de Sódio/química , Microbiologia do Solo , Espectrofotometria Atômica , Deficiência de Vitamina E
20.
Biofactors ; 5(1): 29-37, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-7546216

RESUMO

We have demonstrated that the common soil bacterium, Bacillus subtilis, reduces selenite to an insoluble and much less toxic product--the red form of elemental selenium. Reduction was effected by an inducible system that appears to deposit elemental selenium between the cell wall and the plasma membrane. Glucose and sucrose supported selenite reduction. Although malate and citrate supported growth, no significant reduction of selenite occurred, indicating the importance of the redox state of the culture substrate. Selenite reduction in the millimolar concentration range (i.e., cultures supplemented with 1 mM selenite) was not affected by a ten-fold excess of nitrate or sulfate--compounds that serve as alternate electron acceptors and antagonize selenite reduction by anaerobic bacteria. Similarly, nitrite and sulfite did not significantly affect the rate or extent of selenite reduction. B.subtilis was able to grow and produce selenium (Se degree) at selenite concentrations ranging from 0.6 microM to 5 mM (50 ppb to 395 ppm selenium). At the lowest selenite concentration tested, 50 ppb selenium, B.subtilis removed 95% of the selenite from the liquid phase. The results suggest that selenite is reduced via an inducible detoxification system rather than dissimilatory electron transport. The findings establish the potential utility of B.subtilis for the bioremediation of selenite-polluted sites.


Assuntos
Bacillus subtilis/metabolismo , Selênio/metabolismo , Selenito de Sódio/metabolismo , Bacillus subtilis/crescimento & desenvolvimento , Membrana Celular/metabolismo , Parede Celular/metabolismo , Citratos/farmacologia , Ácido Cítrico , Meios de Cultura , Glucose/farmacologia , Malatos/farmacologia , Nitratos/farmacologia , Oxirredução , Sacarose/farmacologia , Sulfatos/farmacologia
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