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1.
Obstet Gynecol ; 131(6): 1011-1020, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29742658

RESUMO

OBJECTIVE: To compare perinatal and peripartum outcomes of vanishing twin gestations with singleton and dichorionic twin gestations in pregnancies conceived by in vitro fertilization. METHODS: We conducted a retrospective cohort study of vanishing twin pregnancies after fresh and cryopreserved autologous in vitro fertilization cycles performed at our institution from 2007 to 2015. Singleton, dichorionic twin, and dichorionic twin pregnancies with spontaneous reduction to one by 14 weeks of gestation (vanishing twins) were included. Analysis was restricted to patients with a live birth delivery at our institution at or beyond 24 weeks of gestation. The primary outcomes were gestational age and birth weight at delivery; secondary outcomes included peripartum morbidities. A subanalysis further differentiated the vanishing twin pregnancies between those in which demise of the twin occurred before compared with after identification of fetal cardiac activity. Logistic regression models were used to estimate the adjusted odds ratio (OR) with a 95% CI of outcomes. RESULTS: There were 1,189 pregnancies that met inclusion criteria (798 singleton, 291 twin, and 100 vanishing twin). The mean gestational age at birth and birth weights were 38.6±2.3 weeks of gestation and 3,207±644 g in singleton pregnancies, 35.5±2.7 weeks of gestation and 2,539±610 g in twin pregnancies, and 38.5±1.8 weeks of gestation and 3,175±599 g in vanishing twin pregnancies. When compared with twins, those with a vanishing twin had lower odds of preterm delivery (OR 0.13, 95% CI 0.07-0.23; adjusted OR 0.12, 95% CI 0.07-0.22) and small-for-gestational-age birth weight (OR 0.24, 95% CI 0.13-0.45; adjusted OR 0.14, 95% CI 0.07-0.28). CONCLUSION: In pregnancies conceived by in vitro fertilization that progress to at least 24 weeks of gestation, vanishing twin and singleton pregnancies had similar perinatal and peripartum outcomes. Both were significantly better than twin pregnancies.


Assuntos
Aborto Espontâneo/epidemiologia , Transferência Embrionária/efeitos adversos , Fertilização in vitro , Gravidez de Gêmeos , Nascimento Prematuro/epidemiologia , Adulto , Peso ao Nascer , Transferência Embrionária/estatística & dados numéricos , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Nascido Vivo , Modelos Logísticos , Recuperação de Oócitos/estatística & dados numéricos , Gravidez , Resultado da Gravidez , Nascimento Prematuro/etiologia , Estudos Retrospectivos , Fatores de Risco
2.
Am J Obstet Gynecol ; 214(2): 257.e1-257.e6, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26348384

RESUMO

BACKGROUND: Safe tissue removal is a challenge for minimally invasive procedures such as myomectomy, supracervical hysterectomy, or total hysterectomy of a large uterine specimen. There is concern regarding disruption or dissemination of tissue during this process, which may be of particular significance in cases of undetected malignancy. Contained tissue extraction techniques have been developed in an effort to mitigate morcellation-related risks. OBJECTIVE: The objective of the study was to quantify perioperative outcomes of contained tissue extraction using power morcellation, specifically evaluating parameters of tissue or fluid leakage from within the containment system. STUDY DESIGN: This was a study including a multicenter prospective cohort of adult women who underwent minimally invasive hysterectomy or myomectomy using a contained power morcellation technique. Blue dye was applied to the tissue specimen prior to removal to help identify cases of fluid or tissue leakage from within the containment system. RESULTS: A total of 76 patients successfully underwent the contained power morcellation protocol. Mean time for the contained morcellation procedure was 30.2 minutes (±22.4). The mean hysterectomy specimen weight was 480.1 g (±359.1), and mean myomectomy specimen weight was 239.1 g (±229.7). The vast majority of patients (73.7%) were discharged home the same day of surgery. Final pathological diagnosis was benign in all cases. Spillage of dye or tissue was noted in 7 cases (9.2%), although containment bags were intact in each of these instances. CONCLUSION: Findings are consistent with prior work demonstrating the feasibility of contained tissue extraction; however, further refinement of this technique is warranted.


Assuntos
Corantes , Histerectomia/métodos , Leiomioma/cirurgia , Morcelação/métodos , Miomectomia Uterina/métodos , Neoplasias Uterinas/cirurgia , Adulto , Estudos de Coortes , Feminino , Humanos , Laparoscopia/métodos , Pessoa de Meia-Idade , Estudos Prospectivos , Procedimentos Cirúrgicos Robóticos/métodos , Carga Tumoral , Doenças Uterinas/cirurgia
3.
J Assist Reprod Genet ; 32(9): 1379-84, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26206457

RESUMO

PURPOSE: This study aimed to determine whether the presence of an uncleaved embryo on day 3 is predictive of cycle outcome after day 5 transfer (D5 ET). METHODS: In vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles from January 2013 to November 2014 with D5 ET were analyzed for the presence of at least one uncleaved embryo on day 3 (D3). Each index cycle (n = 70) was compared with two matched control cycles without uncleaved embryos. The main outcome measures included embryo quality, implantation rate, and clinical pregnancy rate. RESULTS: Fifty-nine of 3896 total embryos in this study were uncleaved on D3 (1.5 %). Cycles with uncleaved embryos had more oocytes retrieved (20.6 vs. 17.5), lower proportions of good quality embryos on D3 (52.4 vs. 66.1 %), and fewer usable embryos (transferred or frozen) on D5 (42.4 vs. 50.8 %). However, there were no significant differences in the incidence of cycles with a positive hCG, or in the rates of implantation, clinical pregnancy, or live birth. CONCLUSIONS: Although an uncleaved embryo on D3 is associated with reduced conversion of sibling embryos to the blastocyst stage on D5, overall quality of those embryos forming blastocysts is not markedly decreased and clinical outcomes are not compromised.


Assuntos
Fase de Clivagem do Zigoto/citologia , Implantação do Embrião , Embrião de Mamíferos/citologia , Fertilização/fisiologia , Oócitos/citologia , Adulto , Fase de Clivagem do Zigoto/fisiologia , Transferência Embrionária , Embrião de Mamíferos/fisiologia , Feminino , Fertilização in vitro/métodos , Seguimentos , Humanos , Nascido Vivo , Oócitos/fisiologia , Gravidez , Taxa de Gravidez , Prognóstico
4.
Fertil Steril ; 103(5): 1176-84.e2, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25747133

RESUMO

OBJECTIVE: To explore the association between cryopreserved embryo transfer (CET) and risk of placenta accreta among patients utilizing in vitro fertilization (IVF) and/or intracytoplasmic sperm injection (ICSI). DESIGN: Case-control study. SETTING: Academic medical center. PATIENT(S): All patients using IVF and/or ICSI, with autologous or donor oocytes, undergoing fresh or cryopreserved transfer, who delivered a live-born fetus at ≥24 weeks of gestation at our center, from 2005 to 2011 (n = 1,571), were reviewed for placenta accreta at delivery. INTERVENTION(S): Cases of accreta (n = 50) were matched by age and prior cesarean section to controls (1:3) without accreta. The association between CET and accreta was modeled using conditional logistic regression, controlling a priori for age and placenta previa. Receiver operating characteristic curves were used to determine thresholds of endometrial thickness and peak serum E2 levels related to accreta. MAIN OUTCOME MEASURE(S): Placenta accreta. RESULT(S): Univariate predictors of accreta were non-Caucasian race (odds ratio [OR] 2.85, 95% confidence interval [CI] 1.25-6.47); uterine factor infertility (OR 5.80, 95% CI 2.49-13.50); prior abdominal or laparoscopic myomectomy (OR 7.24, 95% CI 1.92-27.28); and persistent or resolved placenta previa (OR 4.25, 95% CI 1.94-9.33). In multivariate analysis, we observed a significant association between CET and accreta (adjusted OR 3.20, 95% CI 1.14-9.02), which remained when analyses were restricted to cases of accreta with morbid complications (adjusted OR 3.87, 95% CI 1.08-13.81). Endometrial thickness and peak serum E2 level were each significantly lower in CET cycles and those with accreta. CONCLUSION(S): Cryopreserved ET is a strong independent risk factor for accreta among patients using IVF and/or ICSI. A threshold endometrial thickness and a "safety window" of optimal peak E2 level are proposed for external validation.


Assuntos
Criopreservação , Transferência Embrionária/efeitos adversos , Fertilização in vitro/efeitos adversos , Placenta Acreta/etiologia , Centros Médicos Acadêmicos , Adulto , Área Sob a Curva , Biomarcadores/sangue , Boston , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Bases de Dados Factuais , Endométrio/patologia , Estradiol/sangue , Feminino , Idade Gestacional , Humanos , Laparoscopia/efeitos adversos , Nascido Vivo , Modelos Logísticos , Análise Multivariada , Razão de Chances , Placenta Acreta/sangue , Placenta Acreta/diagnóstico , Placenta Acreta/etnologia , Valor Preditivo dos Testes , Gravidez , Taxa de Gravidez , Curva ROC , Fatores de Risco , Injeções de Esperma Intracitoplásmicas/efeitos adversos , Resultado do Tratamento , Miomectomia Uterina/efeitos adversos , Miomectomia Uterina/métodos
5.
J Emerg Med ; 47(1): 65-70, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24739318

RESUMO

BACKGROUND: Although oral corticosteroids are commonly given to emergency department (ED) patients with musculoskeletal low back pain (LBP), there is little evidence of benefit. OBJECTIVE: To determine if a short course of oral corticosteroids benefits LBP ED patients. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: Suburban New Jersey ED with 80,000 annual visits. PARTICIPANTS: 18-55-year-olds with moderately severe musculoskeletal LBP from a bending or twisting injury ≤ 2 days prior to presentation. Exclusion criteria were suspected nonmusculoskeletal etiology, direct trauma, motor deficits, and local occupational medicine program visits. PROTOCOL: At ED discharge, patients were randomized to either 50 mg prednisone daily for 5 days or identical-appearing placebo. Patients were contacted after 5 days to assess pain on a 0-3 scale (none, mild, moderate, severe) as well as functional status. RESULTS: The prednisone and placebo groups had similar demographics and initial and discharge ED pain scales. Of the 79 patients enrolled, 12 (15%) were lost to follow-up, leaving 32 and 35 patients in the prednisone and placebo arms, respectively. At follow-up, the two arms had similar pain on the 0-3 scale (absolute difference 0.2, 95% confidence interval [CI] -0.2, 0.6) and no statistically significant differences in resuming normal activities, returning to work, or days lost from work. More patients in the prednisone than in the placebo group sought additional medical treatment (40% vs. 18%, respectively, difference 22%, 95% CI 0, 43%). CONCLUSION: We detected no benefit from oral corticosteroids in our ED patients with musculoskeletal LBP.


Assuntos
Anti-Inflamatórios/uso terapêutico , Dor Lombar/tratamento farmacológico , Dor Musculoesquelética/tratamento farmacológico , Prednisona/uso terapêutico , Administração Oral , Adulto , Anti-Inflamatórios/administração & dosagem , Método Duplo-Cego , Serviço Hospitalar de Emergência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Prednisona/administração & dosagem , Estudos Prospectivos
6.
Gynecol Oncol ; 133(1): 4-10, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24680584

RESUMO

BACKGROUND: Ovarian cancer is often diagnosed at late stages and consequently the 5-year survival rate is only 44%. However, there is limited knowledge of the association of modifiable lifestyle factors, such as physical activity and obesity on mortality among women diagnosed with ovarian cancer. The purpose of our study was to prospectively investigate the association of (1) measured body mass index (BMI), and (2) self-reported physical activity with ovarian cancer-specific and all-cause mortality in postmenopausal women enrolled in the Women's Health Initiative (WHI). METHODS: Participants were 600 women diagnosed with primary ovarian cancer subsequent to enrollment in WHI. Exposure data, including measured height and weight and reported physical activity from recreation and walking, used in this analysis were ascertained at the baseline visit for the WHI. Cox proportional hazard regression was used to examine the associations between BMI, physical activity and mortality endpoints. RESULTS: Vigorous-intensity physical activity was associated with a 26% lower risk of ovarian cancer specific-mortality (HR=0.74; 95% CI: 0.56-0.98) and a 24% lower risk of all-cause mortality (HR=0.76; 95% CI: 0.58-0.98) compared to no vigorous-intensity physical activity. BMI was not associated with mortality. CONCLUSIONS: Participating in vigorous-intensity physical activity, assessed prior to ovarian cancer diagnosis, appears to be associated with a lower risk of ovarian cancer mortality.


Assuntos
Exercício Físico , Atividade Motora , Obesidade/complicações , Neoplasias Ovarianas/mortalidade , Idoso , Índice de Massa Corporal , Causas de Morte , Estudos de Coortes , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Ovarianas/complicações , Sobrepeso/complicações , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores de Risco
7.
J Bacteriol ; 196(7): 1359-68, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24443534

RESUMO

DNA helicases have important roles in genome maintenance. The RecD helicase has been well studied as a component of the heterotrimeric RecBCD helicase-nuclease enzyme important for double-strand break repair in Escherichia coli. Interestingly, many bacteria lack RecBC and instead contain a RecD2 helicase, which is not known to function as part of a larger complex. Depending on the organism studied, RecD2 has been shown to provide resistance to a broad range of DNA-damaging agents while also contributing to mismatch repair (MMR). Here we investigated the importance of Bacillus subtilis RecD2 helicase to genome integrity. We show that deletion of recD2 confers a modest increase in the spontaneous mutation rate and that the mutational signature in ΔrecD2 cells is not consistent with an MMR defect, indicating a new function for RecD2 in B. subtilis. To further characterize the role of RecD2, we tested the deletion strain for sensitivity to DNA-damaging agents. We found that loss of RecD2 in B. subtilis sensitized cells to several DNA-damaging agents that can block or impair replication fork movement. Measurement of replication fork progression in vivo showed that forks collapse more frequently in ΔrecD2 cells, supporting the hypothesis that RecD2 is important for normal replication fork progression. Biochemical characterization of B. subtilis RecD2 showed that it is a 5'-3' helicase and that it directly binds single-stranded DNA binding protein. Together, our results highlight novel roles for RecD2 in DNA replication which help to maintain replication fork integrity during normal growth and when forks encounter DNA damage.


Assuntos
Bacillus subtilis/enzimologia , Proteínas de Bactérias/metabolismo , DNA Helicases/metabolismo , Replicação do DNA , Bacillus subtilis/genética , Bacillus subtilis/crescimento & desenvolvimento , Proteínas de Bactérias/genética , Sequência de Bases , Dano ao DNA , DNA Helicases/genética , Viabilidade Microbiana , Dados de Sequência Molecular , Mutação
8.
PLoS One ; 8(3): e58765, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23536821

RESUMO

Antibacterial compounds typically act by directly inhibiting essential bacterial enzyme activities. Although this general mechanism of action has fueled traditional antibiotic discovery efforts for decades, new antibiotic development has not kept pace with the emergence of drug resistant bacterial strains. These limitations have severely restricted the therapeutic tools available for treating bacterial infections. Here we test an alternative antibacterial lead-compound identification strategy in which essential protein-protein interactions are targeted rather than enzymatic activities. Bacterial single-stranded DNA-binding proteins (SSBs) form conserved protein interaction "hubs" that are essential for recruiting many DNA replication, recombination, and repair proteins to SSB/DNA nucleoprotein substrates. Three small molecules that block SSB/protein interactions are shown to have antibacterial activity against diverse bacterial species. Consistent with a model in which the compounds target multiple SSB/protein interactions, treatment of Bacillus subtilis cultures with the compounds leads to rapid inhibition of DNA replication and recombination, and ultimately to cell death. The compounds also have unanticipated effects on protein synthesis that could be due to a previously unknown role for SSB/protein interactions in translation or to off-target effects. Our results highlight the potential of targeting protein-protein interactions, particularly those that mediate genome maintenance, as a powerful approach for identifying new antibacterial compounds.


Assuntos
Bactérias/genética , Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Ligação a DNA/metabolismo , Genoma Bacteriano , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Proteínas de Transporte/metabolismo , Permeabilidade da Membrana Celular , Replicação do DNA/efeitos dos fármacos , Farmacorresistência Bacteriana , Testes de Sensibilidade Microbiana , Ligação Proteica/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , Recombinases Rec A/metabolismo
9.
Methods Mol Biol ; 922: 161-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22976184

RESUMO

Protein-protein interactions are required for the proper function of many biological pathways. Numerous biochemical and protein blotting methods are available for probing direct and indirect interactions between two protein-binding partners. Here, we describe the methodology of far Western blotting, or immunodot blotting, as a technique for probing direct interactions between two proteins. We describe the utility of this approach as a rapid, qualitative screen for identifying novel protein-binding partners. We also describe the importance of this technique for measuring differences in interaction between wild-type and mutant forms of a known binding partner. Far Western blotting is a rapid and highly reproducible experimental approach for identifying and understanding the interaction between protein-binding partners leading to new discoveries in the function and regulation of biological pathways.


Assuntos
Reparo do DNA , Replicação do DNA , Mapeamento de Interação de Proteínas/métodos , Far-Western Blotting/métodos , Biologia Molecular/métodos , Proteína MutS de Ligação de DNA com Erro de Pareamento/metabolismo , Fatores de Tempo
10.
Microbiol Mol Biol Rev ; 76(3): 530-64, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22933559

RESUMO

From microbes to multicellular eukaryotic organisms, all cells contain pathways responsible for genome maintenance. DNA replication allows for the faithful duplication of the genome, whereas DNA repair pathways preserve DNA integrity in response to damage originating from endogenous and exogenous sources. The basic pathways important for DNA replication and repair are often conserved throughout biology. In bacteria, high-fidelity repair is balanced with low-fidelity repair and mutagenesis. Such a balance is important for maintaining viability while providing an opportunity for the advantageous selection of mutations when faced with a changing environment. Over the last decade, studies of DNA repair pathways in bacteria have demonstrated considerable differences between Gram-positive and Gram-negative organisms. Here we review and discuss the DNA repair, genome maintenance, and DNA damage checkpoint pathways of the Gram-positive bacterium Bacillus subtilis. We present their molecular mechanisms and compare the functions and regulation of several pathways with known information on other organisms. We also discuss DNA repair during different growth phases and the developmental program of sporulation. In summary, we present a review of the function, regulation, and molecular mechanisms of DNA repair and mutagenesis in Gram-positive bacteria, with a strong emphasis on B. subtilis.


Assuntos
Bacillus subtilis/genética , Reparo do DNA , Replicação do DNA , Regulação Bacteriana da Expressão Gênica , Genoma Bacteriano/genética , Bacillus subtilis/crescimento & desenvolvimento , Bacillus subtilis/metabolismo , Dano ao DNA , Mutagênese , Esporos Bacterianos/fisiologia
11.
Mol Microbiol ; 82(3): 648-63, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21958350

RESUMO

Mismatch repair (MMR) corrects DNA polymerase errors occurring during genome replication. MMR is critical for genome maintenance, and its loss increases mutation rates several hundred fold. Recent work has shown that the interaction between the mismatch recognition protein MutS and the replication processivity clamp is important for MMR in Bacillus subtilis. To further understand how MMR is coupled to DNA replication, we examined the subcellular localization of MMR and DNA replication proteins fused to green fluorescent protein (GFP) in live cells, following an increase in DNA replication errors. We demonstrate that foci of the essential DNA polymerase DnaE-GFP decrease following mismatch incorporation and that loss of DnaE-GFP foci requires MutS. Furthermore, we show that MutS and MutL bind DnaE in vitro, suggesting that DnaE is coupled to repair. We also found that DnaE-GFP foci decrease in vivo following a DNA damage-independent arrest of DNA synthesis showing that loss of DnaE-GFP foci is caused by perturbations to DNA replication. We propose that MutS directly contacts the DNA replication machinery, causing a dynamic change in the organization of DnaE at the replication fork during MMR. Our results establish a striking and intimate connection between MMR and the replicating DNA polymerase complex in vivo.


Assuntos
Bacillus subtilis/enzimologia , Bacillus subtilis/fisiologia , Reparo de Erro de Pareamento de DNA , DNA Polimerase III/metabolismo , Replicação do DNA , Proteína MutS de Ligação de DNA com Erro de Pareamento/metabolismo , DNA Polimerase III/genética , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Microscopia Confocal , Microscopia de Fluorescência , Proteína MutS de Ligação de DNA com Erro de Pareamento/genética , Ligação Proteica , Mapeamento de Interação de Proteínas , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo
12.
J Bacteriol ; 192(13): 3452-63, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20453097

RESUMO

The beta clamp is an essential replication sliding clamp required for processive DNA synthesis. The beta clamp is also critical for several additional aspects of DNA metabolism, including DNA mismatch repair (MMR). The dnaN5 allele of Bacillus subtilis encodes a mutant form of beta clamp containing the G73R substitution. Cells with the dnaN5 allele are temperature sensitive for growth due to a defect in DNA replication at 49 degrees C, and they show an increase in mutation frequency caused by a partial defect in MMR at permissive temperatures. We selected for intragenic suppressors of dnaN5 that rescued viability at 49 degrees C to determine if the DNA replication defect could be separated from the MMR defect. We isolated three intragenic suppressors of dnaN5 that restored growth at the nonpermissive temperature while maintaining an increase in mutation frequency. All three dnaN alleles encoded the G73R substitution along with one of three novel missense mutations. The missense mutations isolated were S22P, S181G, and E346K. Of these, S181G and E346K are located near the hydrophobic cleft of the beta clamp, a common site occupied by proteins that bind the beta clamp. Using several methods, we show that the increase in mutation frequency resulting from each dnaN allele is linked to a defect in MMR. Moreover, we found that S181G and E346K allowed growth at elevated temperatures and did not have an appreciable effect on mutation frequency when separated from G73R. Thus, we found that specific residue changes in the B. subtilis beta clamp separate the role of the beta clamp in DNA replication from its role in MMR.


Assuntos
Bacillus subtilis/genética , Reparo de Erro de Pareamento de DNA/fisiologia , Replicação do DNA/genética , Mutação/genética , Western Blotting , Reparo de Erro de Pareamento de DNA/genética , Microscopia , Mutação de Sentido Incorreto/genética
13.
J Vis Exp ; (36)2010 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-20142799

RESUMO

Both prokaryotes and eukaryotes respond to DNA damage through a complex set of physiological changes. Alterations in gene expression, the redistribution of existing proteins, and the assembly of new protein complexes can be stimulated by a variety of DNA lesions and mismatched DNA base pairs. Fluorescence microscopy has been used as a powerful experimental tool for visualizing and quantifying these and other responses to DNA lesions and to monitor DNA replication status within the complex subcellular architecture of a living cell. Translational fusions between fluorescent reporter proteins and components of the DNA replication and repair machinery have been used to determine the cues that target DNA repair proteins to their cognate lesions in vivo and to understand how these proteins are organized within bacterial cells. In addition, transcriptional and translational fusions linked to DNA damage inducible promoters have revealed which cells within a population have activated genotoxic stress responses. In this review, we provide a detailed protocol for using fluorescence microscopy to image the assembly of DNA repair and DNA replication complexes in single bacterial cells. In particular, this work focuses on imaging mismatch repair proteins, homologous recombination, DNA replication and an SOS-inducible protein in Bacillus subtilis. All of the procedures described here are easily amenable for imaging protein complexes in a variety of bacterial species.


Assuntos
Bacillus subtilis/genética , Dano ao DNA , Reparo de Erro de Pareamento de DNA , DNA Bacteriano/análise , Microscopia de Fluorescência/métodos , Replicação do DNA , DNA Bacteriano/genética
14.
Arch Intern Med ; 168(4): 370-7; quiz 345, 2008 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-18299491

RESUMO

BACKGROUND: The effect of combined hormone therapy on breast cancer detection is not established. METHODS: We examined the effect of combined hormone therapy on breast cancer detection in the Women's Health Initiative trial, which randomized 16,608 postmenopausal women to receive conjugated equine estrogens (0.625 mg/d) plus medroxyprogesterone acetate (2.5 mg/d) or placebo. Mammography and breast examinations were performed at baseline and annually per protocol, with breast biopsies based on clinical findings. The effects of conjugated equine estrogens plus medroxyprogesterone acetate on breast cancer detection was determined throughout 5.6 years of intervention using receiver operating characteristic analyses to evaluate mammography results. RESULTS: Conjugated equine estrogens plus medroxyprogesterone acetate increased the cumulative frequency of mammograms with abnormalities vs placebo (35.0% vs 23.0%; P < .001), which had less sensitivity for cancer detection and increased cumulative breast biopsy frequency (10.0% vs 6.1%; P < .001). Although breast cancers were significantly increased and were diagnosed at higher stages in the combined hormone group, biopsies in that group less frequently diagnosed cancer (14.8% vs 19.6%; P = .006). After discontinuation of combined hormone therapy, its adverse effect on mammograms modulated but remained significantly different from that of placebo for at least 12 months (P < .001). CONCLUSIONS: Use of conjugated equine estrogens plus medroxyprogesterone acetate for approximately 5 years resulted in more than 1 in 10 and 1 in 25 women having otherwise avoidable mammogram abnormalities and breast biopsies, respectively, and compromised the diagnostic performance of both. This adverse effect on breast cancer detection should be incorporated into risk-benefit discussions with women considering even short-term combined hormone therapy. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00000611.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Estrogênios Conjugados (USP)/uso terapêutico , Mamografia , Acetato de Medroxiprogesterona/uso terapêutico , Progestinas/uso terapêutico , Idoso , Biópsia , Quimioterapia Combinada , Terapia de Reposição de Estrogênios , Estrogênios , Feminino , Humanos , Pessoa de Meia-Idade
15.
J Lipid Res ; 47(8): 1771-9, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16685082

RESUMO

We aimed to identify mechanisms by which apolipoprotein B-48 (apoB-48) could have an atherogenic role by simultaneously studying the metabolism of postprandial apoB-48 and apoB-100 lipoproteins. The kinetics of apoB-48 and apoB-100, each in four density subfractions of VLDL and intermediate density lipoprotein (IDL), were studied by stable isotope labeling in a constantly fed state with half-hourly administration of almond oil in five postmenopausal women. A non-steady-state, multicompartmental model was used. Despite a much lower production rate, VLDL and IDL apoB-48 shared a similar secretion pattern with apoB-100: both were directly secreted into all fractions with similar percentage mass distributions. Fractional catabolic rates (FCRs) of apoB-48 and apoB-100 were similar in VLDL and IDL. We identified a fast turnover compartment of light VLDL that had a residence time of <30 min for apoB-48 and apoB-100. Finally, a high secretion rate of apoB-48 was associated with a slow FCR of VLDL and IDL apoB-100. In conclusion, the intestine secretes a spectrum of apoB lipoproteins, similar to what the liver secretes, albeit with a much lower secretion rate. Once in plasma, intestinal and hepatic triglyceride-rich lipoproteins have similar rates of clearance and participate interactively in similar metabolic pathways, with high apoB-48 production inhibiting the clearance of apoB-100.


Assuntos
Apolipoproteínas B/metabolismo , Gorduras na Dieta/farmacocinética , Mucosa Intestinal/metabolismo , Fígado/metabolismo , Apolipoproteína B-100 , Apolipoproteína B-48 , Índice de Massa Corporal , Colesterol/metabolismo , Deutério , Gorduras na Dieta/administração & dosagem , Feminino , Humanos , Intestinos/efeitos dos fármacos , Cinética , Lipoproteínas VLDL/metabolismo , Fígado/efeitos dos fármacos , Pessoa de Meia-Idade , Modelos Biológicos
16.
Circulation ; 111(4): 499-510, 2005 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-15687140

RESUMO

BACKGROUND: Few data have evaluated physician adherence to cardiovascular disease (CVD) prevention guidelines according to physician specialty or patient characteristics, particularly gender. METHODS AND RESULTS: An online study of 500 randomly selected physicians (300 primary care physicians, 100 obstetricians/gynecologists, and 100 cardiologists) used a standardized questionnaire to assess awareness of, adoption of, and barriers to national CVD prevention guidelines by specialty. An experimental case study design tested physician accuracy and determinants of CVD risk level assignment and application of guidelines among high-, intermediate-, or low-risk patients. Intermediate-risk women, as assessed by the Framingham risk score, were significantly more likely to be assigned to a lower-risk category by primary care physicians than men with identical risk profiles (P<0.0001), and trends were similar for obstetricians/gynecologists and cardiologists. Assignment of risk level significantly predicted recommendations for lifestyle and preventive pharmacotherapy. After adjustment for risk assignment, the impact of patient gender on preventive care was not significant except for less aspirin (P<0.01) and more weight management recommended (P<0.04) for intermediate-risk women. Physicians did not rate themselves as very effective in their ability to help patients prevent CVD. Fewer than 1 in 5 physicians knew that more women than men die each year from CVD. CONCLUSIONS: Perception of risk was the primary factor associated with CVD preventive recommendations. Gender disparities in recommendations for preventive therapy were explained largely by the lower perceived risk despite similar calculated risk for women versus men. Educational interventions for physicians are needed to improve the quality of CVD preventive care and lower morbidity and mortality from CVD for men and women.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Fidelidade a Diretrizes/estatística & dados numéricos , Conhecimentos, Atitudes e Prática em Saúde , Médicos/psicologia , Guias de Prática Clínica como Assunto , Padrões de Prática Médica/estatística & dados numéricos , Atitude do Pessoal de Saúde , Cardiologia , Fármacos Cardiovasculares/uso terapêutico , Doenças Cardiovasculares/terapia , Administração de Caso/estatística & dados numéricos , Estudos Transversais , Coleta de Dados , Diabetes Mellitus/terapia , Uso de Medicamentos , Feminino , Ginecologia , Humanos , Hiperlipidemias/sangue , Hiperlipidemias/terapia , Hipertensão/terapia , Masculino , Obstetrícia , Educação de Pacientes como Assunto , Atenção Primária à Saúde , Risco , Medição de Risco , Estudos de Amostragem , Fatores Sexuais , Redução de Peso
20.
Obstet Gynecol ; 103(2): 267-73, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14754694

RESUMO

OBJECTIVE: To compare vasomotor symptoms after transition from estrogen-progestin therapy to raloxifene 60 mg/d with and without a placebo washout. METHODS: Postmenopausal women currently taking continuous combined estrogen-progestin therapy (conjugated equine estrogen, 0.625 mg/medroxyprogesterone acetate, 2.5 or 5 mg) daily for 5 or more months were enrolled. Women were randomized to 1 of 4 blinded regimens: 1) 12 weeks estrogen-progestin; 2) 12 weeks placebo; 3) 4 weeks placebo, then 8 weeks raloxifene; or 4) 12 weeks raloxifene. For the final 36 weeks, all subjects received raloxifene. Vasomotor symptoms were assessed by patient diaries. RESULTS: A total of 266 women (mean age 57.5) were enrolled. Mean hot flush frequency at baseline was approximately 1 per week in the entire population, with 16% of women reporting hot flushes. Mean frequency and severity of hot flushes during the first 12 weeks of the study were statistically greater in the 3 groups transitioned off estrogen-progestin (range of hot flushes per week: 4 weeks, 11-12; 8 weeks, 18-24; 12 weeks, 13-16), as compared with those continuing estrogen-progestin, with no difference between these 3 groups (P> or =.1). Approximately 50-70% of these women reported hot flushes, generally rated as mild to moderate by participants, after estrogen-progestin discontinuation. CONCLUSION: A large proportion of women discontinuing estrogen-progestin experience hot flushes. Raloxifene does not appear to increase the frequency or severity of vasomotor symptoms in women discontinuing estrogen-progestin more than that observed with placebo treatment after estrogen-progestin discontinuation. Transition from estrogen-progestin to raloxifene with no washout period therefore may be acceptable. LEVEL OF EVIDENCE: I


Assuntos
Estrogênios Conjugados (USP)/administração & dosagem , Fogachos/tratamento farmacológico , Progestinas/administração & dosagem , Cloridrato de Raloxifeno/administração & dosagem , Sistema Vasomotor/efeitos dos fármacos , Administração Oral , Idoso , Análise de Variância , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Combinação de Medicamentos , Feminino , Seguimentos , Fogachos/diagnóstico , Humanos , Pessoa de Meia-Idade , Pós-Menopausa/efeitos dos fármacos , Pós-Menopausa/fisiologia , Probabilidade , Valores de Referência , Medição de Risco , Índice de Gravidade de Doença , Método Simples-Cego , Resultado do Tratamento
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