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1.
Am J Speech Lang Pathol ; 27(1): 166-180, 2018 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-29351353

RESUMO

Purpose: Name writing is one aspect of emergent writing that has been used to understand emergent literacy development. Name-writing skills and the relationship of name writing to other emergent literacy skills have not been studied extensively in children with specific language impairment (SLI). Children with SLI consistently demonstrate delays in phonological awareness (PA), alphabet knowledge (AK), print awareness, and emergent writing. The purpose of this study was to examine the contributions of PA, AK, and letter writing to name writing in children with SLI and typically developing (TD) children. Method: Participants were 65 children (22 SLI, 43 TD) with an average age of 53 months. Participants completed the Assessment of Literacy and Language (Lombardino, Lieberman, & Brown, 2005), a letter-writing task, and a name-writing task. Results: Data were analyzed using correlation and mediation modeling. Mediation modeling, a more sophisticated analysis, revealed that PA, AK, and letter writing, in serial, were mediating variables for language status on name writing. Conclusion: Phonemic awareness, AK, and letter writing help to explain the relationship between language status and name writing. These skills should be integrated during treatment, using a horizontal approach with developmentally appropriate activities, particularly for children with SLI.


Assuntos
Transtornos do Desenvolvimento da Linguagem/psicologia , Desenvolvimento da Linguagem , Nomes , Leitura , Redação , Linguagem Infantil , Pré-Escolar , Feminino , Humanos , Transtornos do Desenvolvimento da Linguagem/terapia , Alfabetização , Masculino , Fonética
2.
Clin Linguist Phon ; 31(7-9): 682-696, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28481668

RESUMO

Research shows that many preschool children with specific language impairment (SLI) have difficulty acquiring literacy skills including phonological awareness, print concepts, and alphabet knowledge. Limited research suggests that preschool children with SLI also have difficulty with emergent writing tasks such as name writing and word writing. In typically developing children, research indicates that emergent writing skills are acquired in a developmental sequence: (1) linearity, (2) segmentation, (3) simple characters, (4) left-right orientation, (5) complex characters, (6) random letters, and (7) invented spelling. This study compared the emergent writing skills of 4-year-old children with SLI (n = 22) to their age- and gender-matched peers (n = 22). Results indicated that children with SLI demonstrate difficulty with a variety of writing tasks, including letter writing, name writing, word writing, and sentence writing when compared to their typically-developing peers. Children with SLI followed the same developmental sequence in acquiring writing skills as their typically-developing peers.


Assuntos
Linguagem Infantil , Transtornos do Desenvolvimento da Linguagem/psicologia , Redação , Pré-Escolar , Feminino , Humanos , Testes de Linguagem , Masculino
3.
Placenta ; 34(6): 480-5, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23562109

RESUMO

OBJECTIVE: Streptococcus agalactiae (GBS) is an important cause of chorioamnionitis. This study characterizes GBS colonization and stimulation of antimicrobial responses in human extraplacental membranes using an ex vivo transwell two-compartment system of full-thickness membranes and live GBS. STUDY DESIGN: Human extraplacental membranes were affixed to transwell frames (without synthetic membranes). Live GBS was added to the decidual side of membranes in transwell cultures, and cocultures were incubated for 4, 8 and 24 h. GBS recovery from homogenized membranes and culture medium was determined by enumerating colony forming units (CFU) on blood agar. Antimicrobial peptide expression was identified using immunohistochemistry and ELISA. GBS killing by HBDs was assessed in vitro by incubating GBS with different human beta defensins (HBDs) for 3 h, then enumerating CFU. RESULTS: GBS recovery from membranes markedly decreased over time (P < 0.05). The antimicrobial peptides HBD-1, HBD-2, HBD-3, and lactoferrin were expressed in both GBS-exposed and non-exposed tissues. Notably, a pattern of localized increased HBD-2 in the amnion of GBS-infected tissue was observed. Moreover, GBS-treated membranes released increased amounts of HBD-2 into the amniotic and decidual compartments of the transwell cultures after 24 h (P < 0.05). In bacterial cultures, HBD-2 decreased GBS viability in a concentration-dependent manner (P < 0.05). CONCLUSION: Innate immune responses in ex vivo human extraplacental membranes suppress GBS growth. HBD-2 was implicated in this GBS suppression with evidence of signal transduction across the tissue. Antimicrobial peptides may be important for innate immune defense against intrauterine GBS infections during pregnancy.


Assuntos
Âmnio/microbiologia , Anti-Infecciosos/análise , Decídua/microbiologia , Infecções Estreptocócicas/imunologia , Streptococcus agalactiae/fisiologia , beta-Defensinas/análise , Âmnio/química , Âmnio/imunologia , Anti-Infecciosos/metabolismo , Córion/imunologia , Córion/microbiologia , Decídua/imunologia , Feminino , Humanos , Gravidez , Transdução de Sinais , Streptococcus agalactiae/efeitos dos fármacos , Streptococcus agalactiae/crescimento & desenvolvimento , Técnicas de Cultura de Tecidos
4.
Anal Bioanal Chem ; 402(1): 473-87, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22127575

RESUMO

A suite of three green tea-containing Standard Reference Materials (SRMs) has been issued by the National Institute of Standards and Technology (NIST): SRM 3254 Camellia sinensis (Green Tea) Leaves, SRM 3255 Camellia sinensis (Green Tea) Extract, and SRM 3256 Green Tea-Containing Solid Oral Dosage Form. The materials are characterized for catechins, xanthine alkaloids, theanine, and toxic elements. As many as five methods were used in assigning certified and reference values to the constituents, with measurements carried out at NIST and at collaborating laboratories. The materials are intended for use in the development and validation of new analytical methods, and for use as control materials as a component in the support of claims of metrological traceability.


Assuntos
Camellia sinensis/química , Análise de Alimentos/normas , Chá/química , Análise de Alimentos/métodos , Padrões de Referência
5.
Oncogene ; 28(9): 1248-60, 2009 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-19151763

RESUMO

Androgen receptor (AR) signaling is involved in the development and progression of prostate cancer. Tumor microvasculature contributes to continual exposure of prostate cancer cells to hypoxia-reoxygenation, however, the role of hypoxia-reoxygenation in prostate cancer progression and modulation of AR signaling is not understood. In this study, we evaluated the effects of hypoxia-reoxygenation in LNCaP cells, a line of hormone responsive human prostate cancer cells. Our results demonstrate that hypoxia-reoxygenation resulted in increased survival, higher clonogenicity and enhanced invasiveness of these cells. Moreover, hypoxia-reoxygenation was associated with an increased AR activity independent of androgens as well as increased hypoxia inducible factor (HIF-1alpha) levels and activity. We also observed that the activation of p38 mitogen-activated protein (MAP) kinase pathway was an early response to hypoxia, and inhibition of p38 MAP kinase pathway by variety of approaches abolished hypoxia-reoxygenation induced increased AR activity as well as increased survival, clonogenicity and invasiveness. These results demonstrate a critical role for hypoxia-induced p38 MAP kinase pathway in androgen-independent AR activation in prostate cancer cells, and suggest that hypoxia-reoxygenation may select for aggressive androgen-independent prostate cancer phenotype.


Assuntos
Androgênios , Hipóxia Celular , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias da Próstata/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Linhagem Celular Tumoral , Humanos , Masculino , Fenótipo , Neoplasias da Próstata/enzimologia , Neoplasias da Próstata/patologia
6.
J Pathol ; 217(3): 380-8, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19016568

RESUMO

Disease-associated BRCA2 mutations typically result in protein truncations that delete the phosphorylation-regulated S3291 BRCA2 domain that interacts with Rad51. BRCA2 hereditary breast cancers are usually ER(+), differing from BRCA1 hereditary cancers, which are usually ER(-). We studied BRCA2 protein expression and S3291 phosphorylation in normal breast tissues and in sporadic breast cancers and observed that BRCA2 is expressed and phosphorylated in normal breast and 10 ER(+) breast cancers but not in 10 ER(-) breast cancers. In order to study this correlation between ER and BRCA2 expression, we studied ER(+) breast cancer cell lines. We found that a rapid increase in BRCA2 S3291 phosphorylation occurs following 17-beta-oestradiol (E2) treatment. This increase seen in BRCA2 total and phospho-S3291 protein levels was found to be unaffected with cycloheximide pre-treatment, but decreased following tamoxifen, ICI 182,780 or roscovitine treatment. This suggests a requirement for ER and cdk (cyclin-dependent kinase) in mediating the increased protein levels. MCF7 cell cycle distribution analysis following E2, in both the presence and absence of roscovitine (a cdk inhibitor), did not demonstrate any changes during an 8 h period, which further supports our hypothesis that mitogenic effects of E2 are not predominant at early time points. Studies with MG132 proteasome inhibitor and siRNA to skp2 support a model in which skp2-mediated proteasomal degradation of BRCA2 rapidly degrades BRCA2 protein in the absence of hormone treatment, which likely inhibits this pathway. E2 was shown to improve survival of MCF7 cells upon radiation treatment and roscovitine partially reversed this effect. We have demonstrated that BRCA2 protein is specifically expressed in ER(+) breast cancers and are investigating a pathway that may show a link between E2 action and BRCA2 protein function in breast cancer.


Assuntos
Proteína BRCA2/metabolismo , Neoplasias da Mama/metabolismo , Estrogênios/farmacologia , Proteína BRCA2/análise , Western Blotting/métodos , Mama/metabolismo , Linhagem Celular Tumoral , Reparo do DNA , Estrogênios/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Fosforilação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos
8.
Zhonghua Xin Xue Guan Bing Za Zhi ; 33(1): 22-5, 2005 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-15924771

RESUMO

OBJECTIVE: To examine the efficacy and safety of implantation of the device with combined cardiac resynchronization therapy (CRT) and implantable cardioversion defibrillation (ICD) capabilities. METHODS: Eleven patients aged 48 - 80 (71.6 +/- 9.5) years, 7 male and 4 female, were included in the study. All patients had either a history of aborted sudden cardiac death, ventricular tachyarrhythmia, or induced ventricular tachycardia during cardiac electrophysiological study, whose left ventricular ejection fractions were 35% or less and QRS durations were 120 or longer. The patients were implanted a Medtronic INSYNC II MARQUIS(TH) 7289. All left ventricular leads were implanted in left lateral or left posterior lateral side-branches of coronary sinus. The procedures were performed in general anesthesia status. The AV interval was optimized guided by ECHO in all the patients in the day after the procedure. RESULTS: All procedures were successfully completed without major complications. The fluoroscopy time was 19 - 73 (44.7 +/- 19.9) min. Atrial lead amplitude, resistance and threshold were 0.5 - 3.5 (2.47 +/- 0.77) mV, 410 - 749 (590 +/- 126) Omega and 0.9 - 3.0 (1.37 +/- 0.71) V respectively. Right ventricular septal lead amplitude, resistance and threshold were 6.8 - 15.8 (11.00 +/- 3.48) mV, 387 - 750 (586 +/- 116) Omega and 0.4 - 1.0 (0.69 +/- 0.21) V respectively. The amplitude, resistance and threshold of left ventricular leads were 1.2 - 25 (15.37 +/- 5.15) mV, 423 - 812 (602 +/- 125) Omega and 0.3 - 5.0 (1.62 +/- 1.59) V respectively. The defibrillation thresholds (DFT) of 20 J were obtained in 3 patients, 6 J in 3 patients, and 15 J, 12 J and 3 J in one patient respectively. One of the 11 patients with failed old device did not obtain successful DFT after lead and device replacement and was defibrillated externally during DFT test. The another one did not obtain successful DFT because of abnormal ST-T changes in ECG. All devices were programmed to maximum of 30 J and discharged from the hospital in 48 hours except the one who failed to obtain DFT. The patients with mitral regurgitation improved after the AV optimization. CONCLUSIONS: Implantation of device with CRT and ICD features is safe even in aging patients. The long time outcomes of the clinical efficacy of this combined device remain to be observed.


Assuntos
Estimulação Cardíaca Artificial , Desfibriladores Implantáveis , Insuficiência Cardíaca/terapia , Fibrilação Ventricular/terapia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
9.
Proc Natl Acad Sci U S A ; 102(21): 7683-8, 2005 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-15914551

RESUMO

We assayed for the presence of human papilloma virus (HPV) DNA in serum and/or peripheral blood fraction (PBF) of individuals with cervical, head/neck, or bladder cancer due to schistosomiasis. Using mass spectroscopy coupled with competitive PCR, HPV DNA was detected at the individual molecule level by using "MassARRAY" assays. The resultant sensitivity was superior to real-time fluorescent PCR-based assays, while specificity was maintained. Our principal findings were: (i) Virtually all tested cervical cancers and schistosomiasis-associated bladder cancers, and a plurality of head/neck cancers, are associated with HPV DNA in the tumor. (ii) All 27 bladder cancers due to schistosomiasis were associated with the presence of HPV-16 DNA, which can be detected in tumor and serum but not in PBF. In contrast, no serum HPV-16 DNA signal was detected in seven individuals with schistosomiasis-associated bladder cancers after surgical removal of the tumor. (iii) Among the head/neck cancers we studied, anterior tumors were more often associated with HPV DNA in tumor, serum, and/or PBF than posterior tumors. (iv) In cervical cancer, where all tumors contain HPV DNA, viral DNA could be detected often in serum and/or PBF. Further, HPV-16 DNA was detected in serum and/or PBF of most patients with untreated high-grade cervical dysplasia but disappeared if the dysplasia was eliminated. The sensitive, specific, and quantitative MassARRAY technique should make it feasible to monitor cancer occurrence and treatment and recurrence of malignancies and dysplasias associated with HPV DNA.


Assuntos
Neoplasias de Cabeça e Pescoço/virologia , Papillomaviridae/genética , Infecções por Papillomavirus/sangue , Esquistossomose/complicações , Neoplasias da Bexiga Urinária/virologia , Neoplasias do Colo do Útero/virologia , Primers do DNA , Sondas de DNA , Feminino , Neoplasias de Cabeça e Pescoço/etiologia , Humanos , Espectrometria de Massas , Infecções por Papillomavirus/diagnóstico , Reação em Cadeia da Polimerase/métodos , Sensibilidade e Especificidade , Neoplasias da Bexiga Urinária/etiologia , Neoplasias do Colo do Útero/etiologia
11.
J Am Podiatr Med Assoc ; 91(8): 422-6, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11574644

RESUMO

Posterior facet talocalcaneal coalition is one of the rarest forms of talocalcaneal coalition. When a posterior facet coalition occurs, it typically involves a majority of the posterior facet articular surface. The authors present a rare form of posterior facet talocalcaneal coalition in an 11- year-old girl. A brief review of the literature is provided, along with the case history, including radiographic findings and intraoperative and postoperative illustrations.


Assuntos
Procedimentos Ortopédicos/métodos , Articulação Talocalcânea/cirurgia , Sinostose/cirurgia , Calcâneo/diagnóstico por imagem , Calcâneo/patologia , Criança , Feminino , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Radiografia , Amplitude de Movimento Articular/fisiologia , Articulação Talocalcânea/diagnóstico por imagem , Sinostose/diagnóstico por imagem , Sinostose/reabilitação , Resultado do Tratamento
13.
Urology ; 58(2 Suppl 1): 83-90, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11502457

RESUMO

Prostate cancer chemoprevention is defined as the administration of natural and synthetic agents that inhibit >/=1 steps in the natural history of prostate carcinogenesis. The goal is to find agents that modulate the progression from normal epithelium to dysplasia to high-grade prostatic intraepithelial neoplasia (HGPIN) to locally invasive cancer and systemic disease. Another important goal for chemoprevention is the maintenance of an androgen-sensitive clinical state and delay of the emergence of androgen independence. There is a strong rationale for androgen deprivation therapy (ADT) as a chemoprevention strategy for prostate cancer based on evidence from epidemiologic, experimental, molecular pathophysiologic, and randomized, controlled clinical trials. This includes the fact that HGPIN, the most likely precursor of invasive cancer, is androgen dependent and responds to ADT. Although the large, phase-3 Prostate Cancer Prevention Trial (PCPT) of finasteride versus placebo has established the feasibility and role of ADT for primary prevention, nevertheless, limitations of the anticipated treatment-effect size (eg, 25% reduction) and the potential for selection of androgen resistance provide incentive for finding other effective chemopreventive agents. The availability of novel noncytotoxic pharmaceutical and natural products in clinical development create opportunities for improving the therapeutic index through the principles of combination therapy. The emergence of new powerful tools, such as gene chip complementary DNA microarrays for multiplex gene expression profiling, will accelerate the identification of new molecular targets and the design of rational combinations. Several agent classes have a strong basis for combination with ADT, including antiproliferatives, antioxidant micronutrients (selenium), antiestrogens, and nonsteroidal anti-inflammatory drugs (selective cyclooxygenase-2 inhibitors).


Assuntos
Antagonistas de Androgênios/uso terapêutico , Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimioprevenção/métodos , Quimioprevenção/tendências , Desenho de Fármacos , Finasterida/uso terapêutico , Perfilação da Expressão Gênica , Humanos , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasia Prostática Intraepitelial/tratamento farmacológico , Neoplasia Prostática Intraepitelial/genética , Neoplasia Prostática Intraepitelial/prevenção & controle , Neoplasias da Próstata/genética , Neoplasias da Próstata/prevenção & controle
14.
J Pediatr Adolesc Gynecol ; 14(2): 81-4, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11479105

RESUMO

STUDY OBJECTIVE: The purpose of this study is to compare the microscopic examination and human papillomavirus (HPV) DNA subtyping of vulvar specimens from premenarchal girls clinically diagnosed with condyloma to determine whether DNA subtyping aids in the diagnostic process. DESIGN: A retrospective chart review was performed on all premenarchal girls who underwent surgical treatment of clinically diagnosed condyloma between 1993 and 1999 at the University of Michigan Medical Center by the Pediatric and Adolescent Gynecology Service. Tissue was sent for pathologic evaluation and in 10 patients the specimens also underwent DNA subtyping. One patient had prior DNA subtyping. All the other lesions were surgically ablated. The microscopic slides were reviewed by a single pathologist blinded to the study. SETTING: The study was performed in a tertiary care university hospital. PARTICIPANTS: The study group included 11 premenarchal girls with an average age of 2.3 yr. MAIN OUTCOME MEASURES: The charts were reviewed for previous HPV treatment, maternal history of HPV, history of sexual abuse, microscopic diagnosis, and HPV DNA subtyping. RESULTS: Four patients had prior surgical treatment and two patients had undergone prior medical treatment. The microscopic diagnosis was condyloma in 8 patients, chronic dermatitis in 2 patients, and 1 patient had VIN 2-3. All 11 specimens tested positive for HPV DNA, 10 specimens contained at least one of the low-risk subtypes (6, 11, 42, 43, 44), and 1 tested positive for low-risk as well as intermediate/high-risk HPV subtypes (16, 18, 31, 33, 35, 45, 51, 52, 56). CONCLUSIONS: Although all the patients with a clinical diagnosis of condyloma tested positive for HPV DNA, only 9 of 11 were definitely diagnosed with HPV-related pathology by microscopic examination. Therefore, in premenarchal patients with verrucous lesions in the anogenital area, microscopic evaluation alone may be inadequate as a confirmatory test when a positive clinical diagnosis has been made, and HPV DNA subtyping should be considered to avoid confusion with the diagnosis.


Assuntos
Condiloma Acuminado/diagnóstico , DNA Viral/isolamento & purificação , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/diagnóstico , Doenças da Vulva/diagnóstico , Criança , Pré-Escolar , Condiloma Acuminado/patologia , Condiloma Acuminado/cirurgia , Condiloma Acuminado/virologia , Feminino , Humanos , Lactente , Prontuários Médicos , Papillomaviridae/genética , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/cirurgia , Infecções por Papillomavirus/virologia , Estudos Retrospectivos , Doenças da Vulva/patologia , Doenças da Vulva/cirurgia , Doenças da Vulva/virologia
15.
Anal Quant Cytol Histol ; 23(3): 218-28, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11444192

RESUMO

OBJECTIVE: To develop and determine the staining protocols and computerized image analysis methods that are the most effective combination for performing quantitative analysis of Ki-67. STUDY DESIGN: We compared conventional bright-field light microscopy and refractive optical enhancement methods in combination with various immunodetection and filter enhancement methods, including immunogold in combination with epipolarization refractive optics and enzymatic conversion of chromogenic substrates in combination with optical filter enhancement. Initial Ki-67 tests were performed on lymph node tissues and cultured human breast cells and then applied to 200 ductal carcinoma in situ (DCIS) samples. DCIS acini were digitally acquired, and a region of interest was manually outlined in each one with a digital stylus to include only the cellular component; then the Ki-67 staining index was quantified by segmentation analysis. RESULTS: Although combining epipolarization analysis with immunohistogold staining was the most sensitive detection method, nonspecific binding was too high. The streptavidin-horseradish-peroxidase enzymatic conversion of 3,3'-diaminobenzidine (DAB) in combination with optical enhancement filters was the most effective method tested. Ki-67 stain was associated with dense fibrillar structures of the nucleoli in the less intensely staining nuclei and was most intense in paired nuclei. CONCLUSION: The method of measuring Ki-67 expression by DAB staining combined with optical enhancement filters and quantification via computer-assisted image analysis techniques produced objective and reproducible results. As such, this method can offer (1) less intraobserver and interobserver variability, (2) a digital archival record, and (3) a baseline for digital exchange of information between studies.


Assuntos
Neoplasias da Mama/patologia , Carcinoma in Situ/patologia , Carcinoma Ductal de Mama/patologia , Processamento de Imagem Assistida por Computador/métodos , Antígeno Ki-67/análise , Anticorpos Monoclonais , Neoplasias da Mama/química , Carcinoma in Situ/química , Carcinoma Ductal de Mama/química , Feminino , Humanos , Antígeno Ki-67/imunologia , Sensibilidade e Especificidade
16.
Biochemistry ; 40(19): 5674-81, 2001 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-11341832

RESUMO

Nitrosocyanin (NC) is a mononuclear red copper protein isolated from the ammonia oxidizing bacterium Nitrosomonas europaea. Although NC exhibits some sequence homology to classic blue copper proteins, its spectroscopic and electrochemical properties are drastically different. The 1.65 A resolution crystal structure of oxidized NC reveals an unprecedented trimer of single domain cupredoxins. Each copper center is partially covered by an unusual extended beta-hairpin structure from an adjacent monomer. The copper ion is coordinated by His 98, His 103, Cys 95, a single side chain oxygen of Glu 60, and a solvent molecule. In the 2.3 A resolution structure of reduced NC, His 98 shifts away from the copper ion, and the solvent molecule is not observed. The arrangement of these ligands renders the coordination geometry of the NC red copper center distinct from that of blue copper centers. In particular, the red copper center has a higher coordination number and lacks the long Cu-S(Met) and short Cu-S(Cys) bond distances characteristic of blue copper. Moreover, the red copper center is square pyramidal whereas blue copper is typically distorted tetrahedral. Analysis of the NC structure provides insight into possible functions of this new type of biological copper center.


Assuntos
Azurina/análogos & derivados , Proteínas de Bactérias/química , Cobre/química , Metaloproteínas/química , Nitrosomonas/química , Azurina/química , Cristalização , Cristalografia por Raios X , Ligação de Hidrogênio , Oxirredução , Dobramento de Proteína , Estrutura Secundária de Proteína , Homologia de Sequência de Aminoácidos
17.
Cell Death Differ ; 8(2): 182-91, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11313720

RESUMO

Apoptosis is a type of physiological cell death that occurs during development, normal tissue homeostasis, or as a result of different cellular insults. The phenotype of an apoptotic cell is relatively consistent in most cases of apoptosis and involves at least changes in the cell membrane, proteolysis of cytoplasmic and nuclear proteins, and eventual destruction of nuclear DNA. Our laboratory is interested in the reversibility of apoptosis. We have initial evidence that DNA repair is activated early in p53-induced apoptosis and may be involved in its reversibility. The present work further strengthens our proposition that p53-induced apoptosis is reversible. We show that p53 activation induces phosphatidylserine (PS) externalization early in apoptosis, and that these early apoptotic cells with externalized PS can be rescued and proliferate if the apoptotic stimulus is removed. In addition, we show that unscheduled DNA synthesis occurs in early apoptotic cells, and that if DNA repair is inhibited by aphidicolin, apoptosis is accelerated. These results confirm that early p53-induced apoptotic cells can be rescued from the apoptotic program, and that DNA repair can modulate that cell death process.


Assuntos
Apoptose/fisiologia , Reparo do DNA/fisiologia , Fosfatidilserinas/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Afidicolina/farmacologia , Apoptose/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , Fragmentação do DNA/fisiologia , Camundongos
19.
Urology ; 57(4 Suppl 1): 4-27, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11295590

RESUMO

Prostate cancer chemoprevention represents a relatively new and promising strategy for reducing the immense public health burden of this devastating cancer of men in the United States and Western societies. Chemoprevention is defined as the administration of agents (drugs, biologics, and natural products) that modulate (inhibit) one or more steps in the multistage carcinogenesis process culminating in invasive adenocarcinoma of the prostate. In 2000, there were an estimated 170,000 new cases of prostate cancer and 31,000 deaths in the United States. During the past decade, the National Cancer Institute (NCI) organized the chemoprevention research program and began testing the first generation of promising agents (eg, 4-(hydroxy)-fenretinide [4-HPR], difluoromethylornithine [DFMO], antiandrogens) in high-risk cohorts and launched the first-large scale US phase 3 primary prevention trial, known as Prostate Cancer Prevention Trial (PCPT-1), in 18,000 average-risk men (age more than 55 years and prostate-specific antigen [PSA] less than 3 ng/mL) treated for 7 years with finasteride or placebo. In the summer of 1998, the NCI Prostate Cancer Progress Review Group (PRG) Report to the director of NCI was published in response to the leadership of the prostate cancer advocacy community in conjunction with Congress. To further elucidate and address critical issues identified in this report and to develop a research agenda for the newly created Prostate and Urologic Cancer Research Group in the Division of Cancer Prevention at NCI, the NCI organized the workshop "New Clinical Trial Strategies for Prostate Cancer Chemoprevention." The major objectives were to promote understanding and cooperation among the NCI, US Food and Drug Administration (FDA), academia, pharmaceutical industry, and the public regarding new opportunities for clinical prevention trials for prostate cancer. The workshop was divided into three concurrent breakout panels and a fourth joint integrative panel. The workshop addressed multiple key areas identified in the PRG report in the following panels: (1) Molecular Targets and Promising Agents in Clinical Development; (2) Intermediate Endpoint Biomarkers for Prevention Trials; (3) High-Risk Study Populations for Prevention Trials, and (4) Preventive Clinical Trial Designs and Regulatory Issues. Expert panelists were drawn from leading academic, pharmaceutical, and government scientists in basic research and clinical investigation. Key pharmaceutical, biotechnology, academic, and National Institutes of Health scientists presented overviews of their new agents and products in clinical development (representing the next generation of promising agents). Senior FDA physicians from the Center for Drugs and Center for Biologics presented on current standards for new drug and biologic approval for chemoprevention efficacy. Some of the key topics included recent advances in the state of knowledge of promising agents in the clinic based on molecular targets as well as bottlenecks in drug development for pharmaceutical sponsors; strategic modulable biomarkers that can serve as primary endpoints in phase 1/2 trials to assess preventive efficacy; high-risk cohorts with precancer (high-grade prostatic intraepithelial neoplasia) and representative clinical trial designs that are ready for immediate translation into efficient prevention trials, such as Bayesian sequential monitoring for early assessment of biologic activity and factorial designs for assessment of multiagent combinations. Finally, each expert panel generated recommendations for areas of future research emphasizing opportunities and infrastructure needs.


Assuntos
Anticarcinógenos/uso terapêutico , Neoplasias da Próstata/prevenção & controle , Antineoplásicos/uso terapêutico , Biomarcadores Tumorais , Ensaios Clínicos como Assunto , Indústria Farmacêutica , Governo , Humanos , Relações Interinstitucionais , Masculino , Pessoa de Meia-Idade , National Institutes of Health (U.S.) , Guias de Prática Clínica como Assunto , Estados Unidos , United States Food and Drug Administration
20.
Urology ; 57(4 Suppl 1): 46-51, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11295594

RESUMO

Chemoprevention is the use of agents to slow progression of, reverse, or inhibit carcinogenesis thereby lowering the risk of developing invasive or clinically significant disease. With its long latency, high incidence and significant morbidity and mortality, prostate cancer is a relevant target for chemoprevention. Developing rational chemopreventive strategies for prostate cancer requires well-characterized agents, suitable cohorts, and reliable intermediate biomarkers of cancer. Chemopreventive agent requirements are experimental or epidemiologic data showing efficacy, safety on chronic administration, and a mechanistic rationale for activity. Current promising agents include antiandrogens and antiestrogens; steroid aromatase inhibitors; retinoids and their modulators; 5alpha-reductase inhibitors; vitamins D, E, and analogs; selenium compounds; carotenoids; soy isoflavones; dehydroepiandrostenedione and analogs; 2-difluoromethylornithine; lipoxygenase inhibitors; apoptosis inducers; and nonsteroidal anti-inflammatory drugs. Identifying biomarkers and validating them as surrogate endpoints for cancer incidence are critical for prostate chemoprevention trials. Potentially useful biomarkers for prostate chemoprevention are associated with histologic, proliferative, differentiation-related, biochemical, and genetic/regulatory features of prostatic disease. In that the prostate is not easily visualized, critical issues also include adequacy and consistency of tissue sampling. Various drugs for the chemoprevention of prostate cancer are now under evaluation in phase 1, 2, and 3 clinical trials. Cohort selection should be based on various patient characteristics (stage of the disease, previous cancers or premalignant lesions, or high risk factors) and should be conducted within the context of standard treatment.


Assuntos
Anticarcinógenos/uso terapêutico , Neoplasias da Próstata/prevenção & controle , Biomarcadores , Ensaios Clínicos como Assunto , Estudos de Coortes , Humanos , Masculino , Modelos Animais , Seleção de Pacientes , Neoplasias da Próstata/epidemiologia , Fatores de Risco
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