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1.
Res Involv Engagem ; 7(1): 81, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34789334

RESUMO

BACKGROUND: ReIMAGINE aims to improve the current prostate specific antigen (PSA)/biopsy risk stratification for prostate cancer (PCa) and develop a new image-based method (with biomarkers) for diagnosing high/low risk PCa in men. ReIMAGINE's varied patient and public involvement (PPI) and engagement (PE) strategy maximises the impact of its scientific output by informing and shaping the different stages of research. AIMS: Through including the voice of patients and the public, the ReIMAGINE Consortium aims to translate these different perspectives into the design and implementation process. This will improve the overall quality of the research by: reflecting the needs and priorities of patients and the public, ensuring methods and procedures are feasible and appropriate ensuring information is relevant and accessible to those being recruited to the study identifying dissemination channels relevant to patients/the public and developing outputs that are accessible to a lay audience With support from our patient/user groups, the ReIMAGINE Consortium aims to improve our ability to derive prognostic information and allocate men to the most appropriate and effective therapies, using a novel image-based risk stratification with investigation of non-imaging biomarkers. FINDINGS: We have been working with patients and the public from initiation of the project to ensure that the research is relevant to men and their families. Our PPI Sub-Committee, led by a PCa patient, has been involved in our dissemination strategy, outreach activities, and study design recommendations. For example, the sub-committee have developed a variety of informative videos relevant and accessible to those being recruited, and organised multiple online research engagement events that are accessible to a lay audience. As quoted by one of the study participants, "the more we present the benefits and opportunities to patients and the public, the more research commitment we obtain, and the sooner critical clinical questions such as PCa diagnostics will be addressed".


One in eight men will be diagnosed with prostate cancer (PCa). Most will not die of it, but our ability to identify those men whose cancer poses the greatest threat to life has, thus far, been poor. Some men are diagnosed with small cancers which will never cause them a problem, some will have treatment which is unnecessary, others will have their cancers missed, and others will be misclassified as either having low risk cancer and will therefore miss out on the appropriate treatment, or told their cancer is high risk and have unnecessary treatment. Nowhere else in modern medicine are these errors of over-diagnosis, over-treatment, missed-diagnoses, and poor risk-stratification more common. The ReIMAGINE Consortium has been developed to undertake discoveries that will correct these four key errors in the PCa diagnostic pathway. We will investigate how to best identify which men have, or will develop, aggressive prostate cancer using imaging combined with advanced biomarker analyses of blood and urine (i.e., OMICs technologies such as whole genome sequencing, targeted sequencing (e.g.: = , methylation). We will achieve this by building on established partnerships between patients, advocacy organisations, clinicians, imaging experts, molecular biologists, methodologists, and a broad range of industrial partners.The Patient and Public Involvement (PPI) sub-committee is an integral part of the study workflow, contributing to study design and recruitment, results analysis, and dissemination. The committee, led by a funded PPI co-ordinator and a patient chair, have given invaluable insight into the study modifications due to COVID-19 restrictions.

2.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1077-1078: 60-70, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29413578

RESUMO

A method was developed for the confirmatory and quantitative analysis of one pyrethrin and 18 pyrethroid residues in animal fat. Fat was extracted was collected from adipose tissue melted in an oven at 65 °C for 2 h. Fat samples (1 g) were dispersed with deactivated Florisil® sorbent and extracted with MeCN. Sample extracts were purified by cold temperature precipitation at -30 °C for 4 h and further purified using dispersive solid-phase extraction (d-SPE) clean-up in tubes containing 500 mg of Z-SEP+ and 125 mg of PSA bonded silica. Purified samples were analysed by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) detection. Chromatographic separation was carried out on a Acquity C8 BEH column, using a binary gradient separation comprising of mobile phase A, 5 mM ammonium formate in water:MeOH (80:20, v/v,) and mobile phase B, 5 mM ammonium formate in MeOH. The mass spectrometer was operated in the positive electrospray ionisation mode (ESI(+)). Validation was performed following the 2002/657/EC guidelines. Trueness ranged between 84% and 143% and precision ranged between 3.9% and 29%. The developed method is particularly advantageous because the sample preparation procedure does not require complex sample extraction equipment and uses less solvent compared to other sample preparation protocols.


Assuntos
Tecido Adiposo/química , Cromatografia Líquida/métodos , Resíduos de Praguicidas/análise , Piretrinas/análise , Espectrometria de Massas em Tandem/métodos , Animais , Aves , Bovinos , Inocuidade dos Alimentos , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes , Ovinos , Suínos
3.
Osteoporos Int ; 22(12): 3067-72, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21625887

RESUMO

UNLABELLED: The role of B cells in inflammatory bone formation and resorption is controversial. We investigated this in patients with rheumatoid arthritis (RA) treated with rituximab, a B-cell depleting antibody. We found a significant suppression in bone turnover, possibly a direct effect or as a consequence of a reduction in inflammation and disease activity. INTRODUCTION: RA is the most prevalent inflammatory joint disease, in which B cells play an important role. However, the role of B cells in bone turnover is controversial and RA subjects treated with rituximab, a B-cell depleting monoclonal antibody, provide an ideal model for determining the role of B cells in inflammatory bone resorption. METHODS: Serum from 46 RA patients, collected pre- and post-rituximab therapy, was analysed for biomarkers of bone turnover (procollagen type I amino-terminal propeptide [P1NP], osteocalcin, ß-isomerised carboxy-terminal telopeptide of type 1 collagen [ßCTX] and osteoprotegerin [OPG]). RESULTS: A significant decrease in bone resorption was observed 6 months after rituximab (median change ßCTX -50 ng/L, 95%CI -136, -8 p < 0.001, this equates to -37%; 95%CI -6, -49), mirrored by a reduction in disease activity. Similarly, there was a significant increase in P1NP, a marker of bone formation (median change P1NP 5.0 µg/L, 95%CI -1.0, 11.2, p = 0.02; 13%; 95%CI -3, 39), but no significant change in osteocalcin or OPG levels. The percentage change from baseline of ßCTX in a subgroup of patients (not on prednisolone or bisphosphonate) was significantly correlated with the percentage reduction in DAS28 score (r (s) = 0.570, p = 0.014). CONCLUSIONS: In conclusion, we have found that B-cell depletion increases bone formation and decreases bone resorption in RA patients; this may be a direct effect on osteoblasts and osteoclasts, respectively, and be at least partially explained by the decreased inflammation and disease activity.


Assuntos
Anticorpos Monoclonais Murinos/efeitos adversos , Antirreumáticos/efeitos adversos , Artrite Reumatoide/tratamento farmacológico , Linfócitos B/metabolismo , Remodelação Óssea/efeitos dos fármacos , Adulto , Idoso , Idoso de 80 Anos ou mais , Artrite Reumatoide/sangue , Regeneração Óssea/efeitos dos fármacos , Colágeno Tipo I/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoprotegerina/sangue , Fragmentos de Peptídeos/sangue , Peptídeos/sangue , Pró-Colágeno/sangue , Rituximab
4.
J Periodontal Res ; 46(1): 97-104, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20731767

RESUMO

BACKGROUND AND OBJECTIVE: Osteoporosis and periodontal disease are chronic diseases, in the pathogenesis of which plasma osteoprotogerin (OPG) and RANKL are important. The study aimed to investigate the relationship between periodontal disease and plasma cytokines, vitamin D and bone mineral density in postmenopausal women with and without osteoporosis. MATERIAL AND METHODS: One hundred and eighty-five postmenopausal women with osteoporosis and 185 age- and sex-matched control subjects were recruited. Periodontal disease was subdivided into active or past periodontal disease. Osteoprotegerin, RANKL, 25-hydroxyvitamin D3 (25OHD), biochemical markers of bone turnover (serum C-terminal telopeptide, CTX), anthropometry and bone mineral density were measured. RESULTS: A significantly higher proportion of the women with osteoporosis had active or past periodontal disease or both compared with control subjects (87.6 vs. 37.8%, p < 0.001). Plasma 25OHD was significantly lower (p < 0.001) and RANKL and OPG significantly higher in the women with osteoporosis than in control subjects (p < 0.0001). RANKL, OPG and CTX were significantly higher in women with active periodontal disease than in those without (p < 0.001), as were OPG and CTX in past periodontal disease (p < 0.001). In active and past periodontal disease, 25OHD was significantly lower (p < 0.001). Multiple logistic regression analysis showed that periodontal disease was best predicted by RANKL, 25OHD, C-terminal telopeptide and weight, r² = 10.4%. CONCLUSION: Periodontal disease is more common in women with osteoporosis and is associated with lower vitamin D and higher concentrations of RANKL and OPG. Raised cytokines may provide the underlying mechanism that links these two conditions.


Assuntos
Citocinas/sangue , Osteoporose Pós-Menopausa/sangue , Doenças Periodontais/sangue , Idoso , Densidade Óssea , Remodelação Óssea , Calcifediol/sangue , Estudos de Casos e Controles , Colágeno Tipo I/sangue , Feminino , Humanos , Modelos Logísticos , Vértebras Lombares/química , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/complicações , Osteoprotegerina/sangue , Peptídeos/sangue , Doenças Periodontais/complicações , Ligante RANK/sangue , Inquéritos e Questionários
5.
Front Horm Res ; 37: 123-132, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19011293

RESUMO

Osteoporosis and osteoporotic fractures are generally considered to mainly affect older postmenopausal women, but up to 20% of symptomatic vertebral fractures and 30% of hip fractures occur in men. Osteoporotic fractures in men are associated with substantial morbidity, greater excess mortality than in women and account for almost 25% of the cost of osteoporotic fractures in the UK. One of the major secondary causes of osteoporosis in men is hypogonadism, which is found in up to 20% of men with symptomatic vertebral fractures and 50% of elderly men with hip fractures. This chapter outlines the pathogenesis of osteoporosis in men, placing particular emphasis on the importance of sex steroids in the maintenance of bone health. The effects of hypogonadism on the skeleton are described, as well as the consequences of androgen deprivation therapy in men with prostate cancer. Finally, we review the effects of testosterone replacement in hypogonadism and explore other options for the treatment of osteoporosis secondary to loss of sex steroids in men.


Assuntos
Densidade Óssea , Hipogonadismo/complicações , Osteoporose/etiologia , Testosterona/deficiência , Antagonistas de Androgênios/efeitos adversos , Osso e Ossos/metabolismo , Terapia de Reposição Hormonal , Humanos , Masculino , Osteoporose/tratamento farmacológico , Testosterona/uso terapêutico
6.
Bone ; 43(6): 999-1005, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18817902

RESUMO

Sex steroids play an important role in the maintenance of bone density in men and women, but the circulating, biologically active unbound fraction is influenced by the concentration of sex hormone binding globulin (SHBG). SHBG increases with advancing age in men and leads to a reduction in serum free testosterone and oestradiol, which may then affect bone turnover, bone mineral density (BMD) and the risk of fractures. We have therefore measured total and unbound sex steroids, SHBG, bone turnover markers and BMD in 57 men with symptomatic low trauma vertebral fractures and 57 age-matched male control subjects. Fasting blood and urine samples were collected from all subjects, who also underwent BMD measurement of the lumbar spine and hip. Serum testosterone, oestradiol, SHBG, bone specific alkaline phosphatase (bone ALP) and urine free deoxypyridinoline/creatinine ratio (fDPD/Cr) were measured. Free sex steroid concentrations were calculated using their ratio with SHBG and albumin and bioavailable testosterone was measured using radioimmunoassay. The two groups were then compared and regression models developed to determine the best predictors of BMD and fracture. Men with vertebral fractures had significantly lower weight and BMD at all sites than control subjects (p<0.0001). Serum total testosterone and oestradiol did not differ between the two groups, but calculated free androgen and free oestradiol indices were lower in the fracture group than the control subjects (p=0.04), due to higher SHBG (46.6 versus 36.1 nmol/L: p=0.005). The men with vertebral fractures had significantly higher mean bone ALP (15.8 versus 11.8 microg/L: p=0.002) and fDPD/Cr (5.5 versus 4.0 nmol/mmol: p=0.03). Stepwise multiple regression analysis in both fracture and control groups found body weight to be the best predictor of BMD. In the fracture group weight predicted between 19.7 and 30.7% of the variance in BMD and in control subjects this was between 12.3 and 13.2%. SHBG contributed to the model for hip BMD in the fracture group alone, so that weight and SHBG together accounted for 32 to 42.9% of the variance. A model combining BMD at the spine, total femur and femoral neck with height loss best predicted fracture. In conclusion, men with symptomatic vertebral fractures have higher SHBG and lower calculated free sex steroid indices, increased bone turnover and lower BMD. Whilst body weight was the best predictor of BMD, symptomatic vertebral fracture was best predicted by BMD and height loss.


Assuntos
Biomarcadores/sangue , Remodelação Óssea , Estradiol/sangue , Fraturas da Coluna Vertebral/sangue , Testosterona/sangue , Absorciometria de Fóton , Idoso , Densidade Óssea , Estudos de Casos e Controles , Humanos , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Pessoa de Meia-Idade , Hormônio Paratireóideo/sangue , Globulina de Ligação a Hormônio Sexual/metabolismo
8.
Cell Death Differ ; 12(2): 153-61, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15605074

RESUMO

The p53 tumor suppressor promotes apoptosis in response to DNA damage. Here we describe the Caenorhabditis elegans gene ced-13, which encodes a conserved BH3-only protein. We show that ced-13 mRNA accumulates following DNA damage, and that this accumulation is dependent on an intact C. elegans cep-1/p53 gene. We demonstrate that CED-13 protein physically interacts with the antiapoptotic Bcl-2-related protein CED-9. Furthermore, overexpression of ced-13 in somatic cells leads to the death of cells that normally survive, and this death requires the core apoptotic pathway of C. elegans. Recent studies have implicated two BH3-only proteins, Noxa and PUMA, in p53-induced apoptosis in mammals. Our studies suggest that in addition to the BH3-only protein EGL-1, CED-13 might also promote apoptosis in the C. elegans germ line in response to p53 activation. We propose that an evolutionarily conserved pathway exists in which p53 promotes cell death by inducing expression of two BH3-only genes.


Assuntos
Apoptose/fisiologia , Proteínas de Caenorhabditis elegans/fisiologia , Caenorhabditis elegans/fisiologia , Dano ao DNA , Sequência de Aminoácidos , Animais , Proteínas Reguladoras de Apoptose , Caenorhabditis/genética , Caenorhabditis elegans/embriologia , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , DNA/genética , DNA/efeitos da radiação , Deleção de Genes , Regulação da Expressão Gênica no Desenvolvimento/efeitos da radiação , Proteínas de Choque Térmico/genética , Modelos Biológicos , Dados de Sequência Molecular , Mutação , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2 , Proteínas Repressoras/genética , Homologia de Sequência de Aminoácidos , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/fisiologia , Raios X
9.
Nat Biotechnol ; 18(5): 509-14, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10802617

RESUMO

Immunostimulatory DNA sequences (ISS) contain unmethylated CpG dinucleotides within a defined motif. Immunization with ISS-based vaccines has been shown to induce high antigen-specific cytotoxic lymphocyte (CTL) activity and a Th1-biased immune response. We have developed a novel ISS-based vaccine composed of ovalbumin (OVA) chemically conjugated to ISS-oligodeoxynucleotide (ODN). Protein-ISS conjugate (PIC) is more potent in priming CTL activity and Th1-biased immunity than other ISS-based vaccines. Cytotoxic lymphocyte activation by ISS-ODN-based vaccines is preserved in both CD4-/- and MHC class II-/- gene-deficient animals. Furthermore, PIC provides protection against a lethal burden of OVA-expressing tumor cells in a CD8+ cell-dependent manner. These results demonstrate that PIC acts through two unique mechanisms: T-helper-independent activation of CTL and facilitation of exogenous antigen presentation on MHC class I. This technology may have clinical applications in cancer therapy and in stimulating host defense in AIDS and chronic immunosuppression.


Assuntos
Antígenos de Neoplasias/uso terapêutico , Vacinas Anticâncer/uso terapêutico , Neoplasias Experimentais/terapia , Vacinas de DNA/uso terapêutico , Vacinas Sintéticas/uso terapêutico , Animais , Apresentação de Antígeno , Fosfatos de Dinucleosídeos/imunologia , Antígenos de Histocompatibilidade Classe I , Camundongos , Camundongos Mutantes , Linfócitos T Citotóxicos/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Vacinação
11.
Br J Haematol ; 104(4): 868-70, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10192452

RESUMO

The use of the combined oral contraceptive pill (COCP) in women with sickle cell anaemia (SCA) is controversial, as contraceptive steroids are thought to adversely affect erythrocyte deformability. This observational study was performed to investigate whether hormonal contraception influenced erythrocyte deformability in women with SCA. 30 women with SCA using various contraceptive modalities: COCP (n = 10); progestogen only (PO) contraception (n = 10) and non-hormonal contraception (n = 10) were recruited. Erythrocyte deformability was assessed using the clogging rate (CR) and red cell transit time (RCTT). There was no statistical difference in the mean CR and RCTT between the three groups of women (one-way ANOVA). Current contraceptive steroids do not appear to impair red cell deformability in women with SCA.


Assuntos
Anemia Falciforme/complicações , Anticoncepcionais Orais Combinados/efeitos adversos , Anticoncepcionais Orais Hormonais/efeitos adversos , Deformação Eritrocítica/efeitos dos fármacos , Estrogênios/efeitos adversos , Progestinas/efeitos adversos , Adulto , Anemia Falciforme/sangue , Feminino , Humanos , Estudos Prospectivos
12.
Clin Lab Haematol ; 20(3): 151-4, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9681229

RESUMO

Sickle cell disease (SCD) is an incurable debilitating disease affecting the Afro-Caribbean population. The combined oral contraceptive pill (COCP), an effective and popular method of contraception, is often denied to women with SCD for fear that the disease process may have a synergistic effect on the coagulation changes associated with contraceptive steroids. In this study red cell deformability was assessed in 10 women with SCD and 10 comparable women with normal AA haemoglobin. Neither group was on exogenous hormones. The red cells were taken in the follicular phase of the menstrual cycle when women have low endogenous levels of oestradiol and progesterone. The effect of the steroids contained in the COCP on red blood cells was simulated by incubation with therapeutic concentrations of oestradiol and progesterone. Red cell deformability is a measure of the ease with which erythrocytes flow through small capillaries and was assessed using the parameters red cell transit time (RCTT) and clogging rate (CR). Therapeutic concentrations of oestradiol and progesterone did not appear to influence red cell deformability in women with SCD or normal AA haemoglobin.


Assuntos
Anemia Falciforme/sangue , Anticoncepcionais Orais Combinados , Anticoncepcionais Orais Hormonais , Deformação Eritrocítica/efeitos dos fármacos , Eritrócitos Anormais/efeitos dos fármacos , Estradiol/farmacologia , Progesterona/farmacologia , Testosterona/farmacologia , Adulto , Anemia Falciforme/complicações , População Negra , Contraindicações , Membrana Eritrocítica/efeitos dos fármacos , Eritrócitos Anormais/citologia , Feminino , Fase Folicular , Humanos , Fluidez de Membrana/efeitos dos fármacos , Tromboembolia/etiologia , Tromboembolia/prevenção & controle
13.
Eur J Haematol ; 59(2): 76-81, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9293854

RESUMO

The incidence of endocrine dysfunction in relation to the detailed genotype of beta-thalassaemia is investigated in this study. In addition, the association of genotype to specific clinical features of beta-thalassaemia is examined, together with the relationship between serum ferritin levels and endocrine complications. Ninety-seven patients were included, all with transfusion dependent beta-thalassaemia. Patients were divided into 2 categories; group 1 consisted of patients with a beta0/beta0 genotype with or without a concomitant alpha-globin gene deletion as well as patients with beta0/beta+ or beta+/beta+ genotype and normal alpha-globin chain synthesis. Group 2 included patients with beta+/beta+ or beta+/beta0 genotype and one alpha-globin chain deletion and those with a moderate amount of beta-globin chain synthesis (beta++) and normal alpha-globin chain synthesis. The results showed that group 1 patients were more likely to have severe clinical disease (p=0.005). Sixty-four patients (66%) had at least 1 endocrine disorder and 39 (40%) had multiple endocrinopathies; the most common abnormality was hypogonadotrophic hypogonadism (HH). There was a significant association between patients with group 1 genotypes and the presence of HH and impaired glucose tolerance or diabetes. A positive correlation was demonstrated between serum ferritin concentrations and the presence of thyroid or parathyroid dysfunction.


Assuntos
Doenças do Sistema Endócrino/complicações , Sobrecarga de Ferro/metabolismo , Talassemia beta/fisiopatologia , Adolescente , Adulto , Criança , Desferroxamina/uso terapêutico , Feminino , Genótipo , Globinas/genética , Humanos , Hipogonadismo/complicações , Masculino , Fatores de Tempo , Talassemia beta/complicações , Talassemia beta/genética
14.
Genes Dev ; 9(24): 3149-62, 1995 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-8543158

RESUMO

The Caenorhabditis elegans gene lin-1 appears to act after the Ras-Raf-MEK-MAPK signaling cascade that mediates vulval induction. We show that lin-1 is a negative regulator of vulval cell fates and encodes an ETS-domain putative transcription factor containing potential MAPK phosphorylation sites. In lin-1 null mutants, the vulval precursor cells (VPCs) still respond to signaling from the gonadal anchor cell, indicating that lin-1 defines a branch of the inductive signaling pathway. We also provide evidence that the inductive and lateral signaling pathways are integrated to control the 1 degree and 2 degrees vulval cell fates after the point at which lin-1 acts in the inductive pathway and that VPCs can assess the relative rather than absolute levels of inductive and lateral signaling in determining whether to express the 1 degree or 2 degrees vulval cell fates.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans/embriologia , Regulação da Expressão Gênica no Desenvolvimento , Proteínas Proto-Oncogênicas/genética , Fatores de Transcrição/genética , Vulva/embriologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Caenorhabditis elegans/genética , Clonagem Molecular , DNA Complementar , Feminino , Dados de Sequência Molecular , Mutação Puntual , Proteínas Proto-Oncogênicas c-ets , Homologia de Sequência de Aminoácidos
15.
Biochemistry ; 31(30): 6911-6, 1992 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-1637824

RESUMO

Cytochrome P4502B1 reacts with phenylhydrazine or phenyldiazene to give an iron-phenyl complex that oxidatively rearranges in situ to the two N-phenylprotoporphyrin IX regioisomers with the phenyl group on pyrrole rings A (NA) and D (ND) [Swanson, B. A., Dutton, D. R., Lunetta, J. M., Yang, C. S., & Ortiz de Montellano, P. R. (1991) J. Biol. Chem. 266, 19258-19264]. The conclusion that the active site of cytochrome P4502B1 is open above pyrrole rings A and D but not B and C is extended here by studies with larger arylhydrazines. The N-arylprotoporphyrin IX standards required for product identification were obtained by reaction of the arylhydrazines with equine myoglobin. Cytochrome P4502B1 aryl-iron complex formation followed by oxidative shift of the aryl group produces the following N-aryl-protoporphyrin IX NA:ND regioisomer ratios: phenylhydrazine (39:61), 3,5-dimethylphenylhydrazine (29:71), 4-tert-butylhydrazine (25:75), 2-naphthylhydrazine (less than 2:greater than 98), and 4-(phenyl)phenylhydrazine (87:13). Electron-withdrawing substituents (as in 3,5-dichlorophenyl) prevent the aryl group shift. The increase in the proportion of the ND regioisomer with increasing bulk of the aryl group suggests that the region over pyrrole ring A is more sterically encumbered than that over pyrrole ring D. The regiospecificity is reversed, however, with 4-(phenyl)phenylhydrazine, which primarily gives the NA regioisomer. This reversal suggests that the active site has a sloping roof that is higher over pyrrole ring A than pyrrole ring D and that provides a larger steric barrier to the shift of tall aryl moieties than the barrier over pyrrole ring A.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Sistema Enzimático do Citocromo P-450/química , Hidrazinas/metabolismo , Ferro/metabolismo , Animais , Sítios de Ligação , Cromatografia Líquida de Alta Pressão , Sistema Enzimático do Citocromo P-450/metabolismo , Iminas/metabolismo , Metamioglobina/metabolismo , Estrutura Molecular , Fenil-Hidrazinas/metabolismo , Ratos
16.
Prenat Diagn ; 12(8): 685-8, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1438061

RESUMO

Over a period of 25 months, all antenatal patients were offered a detailed ultrasound scan at 18-20 weeks' gestation. The lateral cerebral ventricles were scanned for the presence of choroid plexus cysts. Fifty-one patients found to have choroid plexus cysts were offered amniocentesis to exclude chromosomal abnormalities. One pregnancy, in which the only abnormality found was bilateral choroid plexus cysts, was terminated after trisomy 18 was detected on amniocentesis at 19 weeks. The other 50 pregnancies had normal fetal outcomes. The significance of the isolated finding of choroid plexus cysts is reviewed.


Assuntos
Encefalopatias/epidemiologia , Plexo Corióideo/patologia , Cistos/epidemiologia , Diagnóstico Pré-Natal , Adulto , Amniocentese , Encefalopatias/complicações , Encefalopatias/diagnóstico por imagem , Encefalopatias/genética , Cromossomos Humanos Par 18 , Cistos/complicações , Cistos/diagnóstico por imagem , Cistos/genética , Feminino , Humanos , Cariotipagem , Gravidez , Segundo Trimestre da Gravidez , Estudos Prospectivos , Trissomia , Ultrassonografia
17.
J Biol Chem ; 267(8): 5614-20, 1992 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-1544935

RESUMO

The reactions of cytochromes P450101 (P450cam), P450108 (P450terp), and P450102 (P450BM-3) with phenyldiazene result in the formation of phenyl-iron complexes with absorption maxima at 474-478 nm. Treatment of the cytochrome P450 complexes with K3Fe(CN)6 decreases the 474-478 nm absorbance and shifts the phenyl group from the iron to the porphyrin nitrogens. Acidification and extraction of the prosthetic group from each of the ferricyanide-treated enzymes yields a different mixture of the four possible N-phenylprotoporphyrin IX regioisomers. The ratios of the regioisomers with the phenyl ring on pyrrole rings B, A, C, and D (in order of elution from the high performance liquid chromatography column) are, respectively: cytochrome P450cam, 0:0:1:4; P450terp, 0:0:0:1; and P450BM-3, 2:10:2:1. The isomer ratio for recombinant cytochrome P450BM-3 without the cytochrome P450 reductase domain (2:9:2:1) shows that the reductase domain does not detectably perturb the active site topology of cytochrome P450BM-3. Potassium ions modulate the intensity of the spectrum of the phenyl-iron complex of cytochrome P450cam, but do not alter the N-phenyl isomer ratio. Computer graphics analysis of the crystal structure of the cytochrome P450cam phenyl-iron complex indicates that the active site of cytochrome P450cam is open above pyrrole ring D and, to a small extent, pyrrole ring C, in complete agreement with the observed N-phenylprotoporphyrin IX regioisomer pattern. The regioisomer ratios indicate that the active site of cytochrome P450terp is only open above pyrrole ring D, whereas that of cytochrome P450BM-3 is open to some extent above all the pyrrole rings but particularly above pyrrole ring A. The bacterial enzymes thus have topologies distinct from each other and from those of the mammalian enzymes so far investigated, which have active sites that are open to a comparable extent above pyrrole rings A and D.


Assuntos
Proteínas de Bactérias , Sistema Enzimático do Citocromo P-450/metabolismo , Escherichia coli/enzimologia , Iminas/metabolismo , Isoenzimas/metabolismo , Oxigenases de Função Mista/metabolismo , Sítios de Ligação , Cânfora 5-Mono-Oxigenase , Ferricianetos/metabolismo , Cinética , Modelos Moleculares , NADPH-Ferri-Hemoproteína Redutase , Ligação Proteica , Conformação Proteica , Espectrofotometria
18.
Prenat Diagn ; 10(3): 195-8, 1990 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2188250

RESUMO

A case is described of the diagnosis by ultrasound scanning during the second trimester of Conradi-Hünermann's syndrome (asymmetrical rhizomelic limb shortening or chondrodysplasia calcificans punctata). The prenatal diagnosis of limb shortening deformities is discussed.


Assuntos
Condrodisplasia Punctata/diagnóstico , Diagnóstico Pré-Natal , Adulto , Condrodisplasia Punctata/genética , Feminino , Fêmur/anormalidades , Humanos , Úmero/anormalidades , Gravidez , Ultrassonografia
19.
Mol Cell Biol ; 9(5): 2163-72, 1989 May.
Artigo em Inglês | MEDLINE | ID: mdl-2664471

RESUMO

Transcriptional deregulation of the p53 gene may play an important part in the genesis of some tumors. We report here an accurate determination of the transcriptional start sites of the human p53 gene and show that the majority of p53 mRNA molecules do not contain a postulated stem-loop structure at their 5' ends. Recombinant plasmids of the human p53 promoter-leader region fused to the bacterial chloramphenicol acetyltransferase gene (cat) were constructed. After transfection into rodent or human cells, a 350-base-pair fragment spanning the promoter region conferred 4% of the CAT activity mediated by the simian virus 40 early promoter/enhancer. We monitored the efficiency with which 15 3' and 5' promoter deletion constructs initiated transcription. Our results show that an 85-base-pair fragment, previously thought to have resided in exon 1, is all that is required for full promoter activity.


Assuntos
Proteínas de Neoplasias/genética , Fosfoproteínas/genética , Regiões Promotoras Genéticas , Sequência de Bases , Deleção Cromossômica , DNA/genética , Humanos , Dados de Sequência Molecular , Mutação , Oncogenes , RNA Mensageiro/genética , Mapeamento por Restrição , Transcrição Gênica , Proteína Supressora de Tumor p53
20.
Oncogene Res ; 4(2): 81-96, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2654816

RESUMO

Some, but not all, mouse p53 genes are able to cooperate with an activated ras oncogene to transform primary cells. Overexpression of what is presumed to be wild-type murine p53 is sufficient to confer a tumorigenic phenotype on established cell lines. We have investigated the effect of overexpression of normal human p53 genes on the growth and morphology of both primary and established mouse and rat cells. When plasmids containing functional human p53 genes under the control of strong viral promoter/enhancer elements were transfected into NIH3T3 cells or Rat-1 cells, no gross alterations in cell shape or morphology were observed. When stable NIH3T3 transfectants were established by co-transfection of the p53 plasmids with pSV2neo and subsequent selection in medium containing G418, many of the lines generated exhibited altered growth characteristics. While, again, the cells did not form foci above the monolayer and were not capable of growing in soft agar, they showed a reduced dependence on serum for growth, were able to grow to higher saturation densities, and displayed markedly enhanced tumorigenicity when inoculated into nude mice. The expression of human p53 in the transfectants was assessed by immunoblotting with a monoclonal antibody, PAb1801, which is reactive to human but not mouse p53. There was a clear correlation between the extent of p53 overexpression and acquisition of the tumorigenic phenotype. None of nine human p53 constructs was capable of cooperating with an activated ras oncogene to transform primary cells under conditions where a mouse clone, pLTRp53cG, could do so efficiently. None of the human p53 constructs was capable of rescuing primary rat cells from senescence. Taken together, these data show that overproduction of normal human p53 can confer an enhanced tumorigenic phenotype on established fibroblasts and support the idea that mutational activation may be necessary for p53 to express its full oncogenic potential.


Assuntos
Transformação Celular Neoplásica , Proteínas de Neoplasias/biossíntese , Proteínas Nucleares/biossíntese , Fosfoproteínas/biossíntese , Animais , DNA , Fibroblastos , Genes ras , Humanos , Camundongos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/imunologia , Fosfoproteínas/genética , Fosfoproteínas/imunologia , Plasmídeos , Testes de Precipitina , Transfecção , Proteína Supressora de Tumor p53
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