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1.
Ann Oncol ; 2024 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-39284381

RESUMO

BACKGROUND: The phase III PRIMA/ENGOT-OV26/GOG-3012 trial met its primary endpoint. Niraparib first-line maintenance significantly prolonged progression-free survival (PFS) among patients with newly diagnosed advanced ovarian cancer that responded to first-line platinum-based chemotherapy, regardless of homologous recombination deficiency (HRD) status. Final overall survival (OS) results are reported. PATIENTS AND METHODS: Patients were randomized 2:1 to niraparib or placebo, stratified by response to first-line treatment, receipt of neoadjuvant chemotherapy, and tumor HRD status. After reaching 60% target maturity, OS was evaluated via a stratified log-rank test using randomization stratification factors and summarized using Kaplan-Meier methodology. OS testing was hierarchical [overall population first, then the homologous recombination-deficient (HRd) population]. Other secondary outcomes and long-term safety were assessed; an updated, ad hoc analysis of investigator-assessed PFS was also conducted (cut-off date, 8 April 2024). RESULTS: The median follow-up was 73.9 months. In the overall population, the OS hazard ratio was 1.01 [95% confidence interval (CI) 0.84-1.23; P = 0.8834] for niraparib (n = 487) versus placebo (n = 246). In the HRd (n = 373) and homologous recombination-proficient (n = 249) populations, the OS hazard ratios were 0.95 (95% CI 0.70-1.29) and 0.93 (95% CI 0.69-1.26), respectively. Subsequent poly(ADP-ribose) polymerase inhibitor therapy was received by 11.7% and 15.8% of niraparib patients and 37.8% and 48.4% of placebo patients in the overall and HRd populations, respectively. The 5-year PFS rate numerically favored niraparib in the overall (niraparib, 22%; placebo, 12%) and HRd populations (niraparib, 35%; placebo, 16%). Myelodysplastic syndromes/acute myeloid leukemia incidence was <2.5% (niraparib, 2.3%; placebo, 1.6%). No new safety signals were observed. CONCLUSIONS: In patients with newly diagnosed advanced ovarian cancer at high risk of recurrence, there was no difference in OS between treatment arms. In the HRd population, patients alive at 5 years were two times as likely to be progression free with niraparib treatment than placebo. Long-term safety remained consistent with the established niraparib safety profile.

2.
Gynecol Oncol ; 166(2): 245-253, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35835611

RESUMO

OBJECTIVE: Pembrolizumab demonstrated a clinically meaningful objective response rate in patients with previously treated, advanced MSI-H/dMMR endometrial cancer in the multicohort phase 2 KEYNOTE-158 study (ClinicalTrials.gov, NCT02628067). We present health-related quality of life (HRQoL) results for these patients. METHODS: This analysis included patients from cohorts D (endometrial cancer with any MSI status) and K (any MSI-H/dMMR solid tumor except colorectal) who had previously treated, advanced MSI-H/dMMR endometrial cancer. Patients received pembrolizumab 200 mg Q3W for 35 cycles. EORTC QLQ-C30 and EQ-5D-3L questionnaires were administered at baseline, at regular intervals during treatment, and 30 days after treatment discontinuation. Pre-specified exploratory analyses included changes from baseline to week 9 in QLQ-C30 global health status (GHS)/QoL and EQ-5D-3L visual analog scale (VAS) score for all patients and by best overall response. RESULTS: 84 of 90 enrolled patients completed ≥1 HRQoL questionnaire and were included in the analysis. QLQ-C30 and EQ-5D-3L compliance rates were 90% and 94%, respectively, at baseline, and 92% and 93% at week 9. Mean (95% CI) QLQ-C30 GHS/QoL scores improved from baseline to week 9 by 6.08 (0.71-11.46) points in the overall population, with greater improvement in patients who achieved complete or partial response (11.67 [5.33-18.00]-point increase). Mean (95% CI) EQ-5D-3L VAS scores improved by 6.00 (2.25-9.75) points in the overall population and 9.11 (5.24-12.98) points in patients with CR/PR. CONCLUSIONS: Pembrolizumab maintained or improved HRQoL in patients with previously treated, advanced MSI-H/dMMR endometrial cancer, further supporting efficacy and safety results from KEYNOTE-158 and pembrolizumab use in this setting.


Assuntos
Neoplasias do Endométrio , Qualidade de Vida , Anticorpos Monoclonais Humanizados , Reparo de Erro de Pareamento de DNA , Neoplasias do Endométrio/tratamento farmacológico , Neoplasias do Endométrio/genética , Feminino , Humanos , Instabilidade de Microssatélites
3.
Gynecol Oncol ; 160(3): 688-695, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33390325

RESUMO

BACKGROUND: EP0057 (formerly CRLX101) is an investigational nanoparticle-drug conjugate (NDC) of a cyclodextrin-based polymer backbone plus camptothecin, a topoisomerase-1 inhibitor. Prior studies showed efficacy in recurrent or persistent, epithelial ovarian, fallopian tube or primary peritoneal cancer (EOC). METHODS: This phase Ib/2 trial assessed safety and efficacy of EP0057 Q2W plus weekly paclitaxel in patients with EOC. The recommended phase 2 dose (RP2D) was identified using a 3+3 design. The single-arm phase 2 assessed overall response (ORR) per RECIST 1.1 in patients previously treated with bevacizumab. Secondary objectives included progression free survival (PFS) and duration of response. RESULTS: The RP2D was established as 15 mg/m2 EP0057 Q2W plus 80 mg/m2 paclitaxel administered 3 weeks on/1 week off. Nine patients enrolled on phase 1b, with no DLTs; 21 additional patients enrolled on phase 2. All completed >1 cycle. Median age was 62 (44-76) years, 57% ≥3 prior therapies. For the primary analysis, 6/19 patients with prior bevacizumab had confirmed responses (ORR=31.6% (95% CI: 15.4% to 54.0%)) including one complete response (CR). Median PFS was 5.4 months. Most common grade 3/4 adverse events attributed to treatment were decreased neutrophil count (13, 43%) and anemia (3, 10%). CONCLUSIONS: Although the observed ORR was not statistically better than the historical control rate, EP0057 remains an interesting option for treatment of recurrent EOC. EP0057 exhibits high plasma drug retention, slow clearance, and controlled slow release of CPT from the polymer when administered alone and with paclitaxel. (NCT02389985) 242 words.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Neoplasias das Tubas Uterinas/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Paclitaxel/uso terapêutico , Neoplasias Peritoneais/tratamento farmacológico , Adulto , Idoso , Antineoplásicos Fitogênicos/farmacologia , Feminino , Humanos , Pessoa de Meia-Idade , Paclitaxel/farmacologia , Intervalo Livre de Progressão
4.
Gynecol Oncol ; 156(3): 530-534, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31937450

RESUMO

OBJECTIVES: Intraperitoneal (IP) chemotherapy following neoadjuvant chemotherapy (NACT) and interval tumor reductive surgery (TRS) for advanced ovarian cancer is feasible, however, the impact on disease outcomes remains unclear. We compare outcomes of patients treated with IP chemotherapy versus intravenous (IV) chemotherapy following NACT and interval TRS. METHODS: In this retrospective review, patients with advanced ovarian cancer were included if they received NACT followed by optimal interval TRS between 1/2004 and 4/2017. Patients were excluded if they had an ECOG PS >1, received >6 cycles of NACT or postoperative chemotherapy, and/or received bevacizumab during primary therapy. Primary outcomes were progression free survival (PFS) and overall survival (OS). RESULTS: There were 134 patients included in this study, 37 (28%) received IP and 97 (72%) received IV chemotherapy postoperatively. Patients in the IV group were older (median 66.3 vs 59.7 years, p = 0.0039) though there were no differences in BMI, race, BRCA status, stage, or histology. Median PFS was 3 months longer in the IP group (14.5 versus 11.5 months, p = 0.028) however there was no significant difference in OS. On univariate analysis, increasing number of NACT cycles (HR 1.914, 95% CI 1.024-3.497) and residual disease at completion of TRS (HR 1.541, 95% CI 1.042-2.248) were associated with decreased PFS; IP chemotherapy was associated with increased PFS (HR 0.633, 95% CI 0.414-0.944). These associations remained on multivariate analysis. Toxicity was comparable between the groups. CONCLUSIONS: IP after NACT and optimal interval TRS was associated with in improved PFS compared to IV chemotherapy without significant differences in toxicity.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma Epitelial do Ovário/tratamento farmacológico , Carcinoma Epitelial do Ovário/cirurgia , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma Epitelial do Ovário/patologia , Quimioterapia Adjuvante , Procedimentos Cirúrgicos de Citorredução , Feminino , Humanos , Infusões Intravenosas , Infusões Parenterais , Pessoa de Meia-Idade , Terapia Neoadjuvante , Compostos Organoplatínicos/administração & dosagem , Compostos Organoplatínicos/efeitos adversos , Neoplasias Ovarianas/patologia , Intervalo Livre de Progressão , Estudos Retrospectivos , Taxoides/administração & dosagem , Taxoides/efeitos adversos , Adulto Jovem
6.
Gynecol Oncol ; 129(1): 103-6, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23369942

RESUMO

OBJECTIVE: The objective of this study was to evaluate peri-operative and survival outcomes of ovarian cancer patients undergoing percutaneous upper gastrointestinal decompression for malignant bowel obstruction (MBO). METHODS: Retrospective chart review was used to identify patients with ovarian, peritoneal, or fallopian tube cancer who underwent palliative decompressive treatment for MBO from 1/2002 to 12/2010. Kaplan-Meier methods were used to estimate the median survival (MS) and multivariate analysis used to determine if any variables were associated with the hazard of death. RESULTS: Fifty-three patients met inclusion criteria. Median length of diagnosis prior to intervention was 21 months. Fifteen (28.3%) patients experienced complications and 9 required revision. Forty-nine (92.5%) experienced relief of symptoms after placement, and 91% tolerated some form of oral intake. Following placement, 19 (36%) patients received additional chemotherapy and 21(41%) patients received total parental nutrition (TPN). Thirty-five patients were discharged home/outpatient facility, 16 to hospice care, and 2 died prior to discharge. MS for all patients was 46 days. Patients who received chemotherapy had a MS of 169 days compared to 33 days (p<0.001). We failed to find an association between survival and TPN or performance status. CONCLUSIONS: Malignant bowel obstruction is a common complication of ovarian cancer. Management is palliative; risks and benefits of any therapy must be considered. Percutaneous decompressive therapy provides relief from associated symptoms, and allows patients to be discharged home. Median survival in this group is limited, and decisions regarding aggressive therapy should be individualized.


Assuntos
Descompressão Cirúrgica , Obstrução Intestinal/cirurgia , Neoplasias Ovarianas/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Obstrução Intestinal/mortalidade , Pessoa de Meia-Idade , Cuidados Paliativos , Nutrição Parenteral Total , Estudos Retrospectivos , Resultado do Tratamento
7.
Gynecol Oncol ; 124(2): 221-4, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22055764

RESUMO

INTRODUCTION: Hematologic, gastrointestinal, and neurologic complications are common side effects of the platinum and taxane-based chemotherapy used in the primary treatment of epithelial ovarian cancer (EOC). These side effects and the impact of the resultant chemotherapy dose modification on disease free interval have not been extensively studied. The goal of this study was to determine the effect of chemotherapy delays and dose reductions on progression free survival (PFS) and overall survival (OS). METHODS: A review of patients with primary epithelial ovarian, peritoneal, and fallopian tube carcinoma treated between 1/2000 and 12/2007 was performed. Inclusion criteria were advanced stage disease and first line chemotherapy with a platinum and taxane regimen. Cox proportional hazard models were used to determine the effect of chemotherapy reductions and delays on PFS and OS. RESULTS: One hundred and fifty seven patients met the inclusion criteria. Patients were divided into four groups: no delays or reductions (48%), delay only (27%), reduction only (8%), and both delay and reduction (18%). The mean number of delays/reductions per patient was 1.1 (range=0-5) and therapy was delayed a mean of 8 days. The most common reasons for delays/reductions were neutropenia (n=51), thrombocytopenia (n=45), and neuropathy (n=18). There were no differences detected in PFS or OS between groups. CONCLUSIONS: There were no differences detected in survival between patients who required dose adjustments and treatment delays and those who did not. The lack of association between survival and chemotherapy alterations suggests that in specific circumstances patients with advanced ovarian cancer should have individualized treatment plans.


Assuntos
Antineoplásicos/administração & dosagem , Neoplasias Epiteliais e Glandulares/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Epitelial do Ovário , Intervalo Livre de Doença , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Ovarianas/patologia , Estudos Retrospectivos , Taxa de Sobrevida , Adulto Jovem
8.
Gynecol Oncol ; 118(1): 47-51, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20382413

RESUMO

BACKGROUND: Increased rates of bowel perforation in patients with recurrent epithelial ovarian cancer (EOC) treated with bevacizumab have been reported, but the risk factors for this association are uncertain. We sought to identify factors associated with bowel perforation and fistula formation in recurrent EOC patients treated with bevacizumab. METHODS: A chart review of all patients treated with bevacizumab for recurrent EOC at a single institution was performed. Pertinent patient characteristics and treatment information were collected. Univariate logistic regression was performed to analyze multiple variables. RESULTS: One hundred twelve patients who were treated with 160 different bevacizumab regimens were identified. The median age was 60 years (range, 29-78 years). Patients had received a median of 4 prior chemotherapy regimens (range, 1-10). The median number of cycles was 4 (range, 0.5-31). Ten patients (9%) were diagnosed with bowel perforations, and another 2 patients (1.8%) were diagnosed with fistulas. The 30-day mortality following perforation was 50%, with 30% of patients dying within 1 week. Patients with rectovaginal nodularity were more likely to develop a bowel perforation or fistula than those who did not have this finding, OR=3.64 (95% CI=1.1 to 12.1, p=0.04). None of the other variables were significantly associated with bowel perforations or fistula formation. CONCLUSIONS: Rectovaginal nodularity is associated with an increased risk of bowel perforation or fistula formation for patients with recurrent EOC treated with bevacizumab. Careful consideration should be given prior to initiating bevacizumab treatment in EOC patients with rectovaginal nodularity since the mortality rate with bevacizumab associated bowel perforations is 50%.


Assuntos
Anticorpos Monoclonais/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Perfuração Intestinal/induzido quimicamente , Recidiva Local de Neoplasia/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Adulto , Idoso , Inibidores da Angiogênese/administração & dosagem , Inibidores da Angiogênese/efeitos adversos , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Bevacizumab , Células Epiteliais/patologia , Neoplasias das Tubas Uterinas/tratamento farmacológico , Neoplasias das Tubas Uterinas/patologia , Feminino , Humanos , Perfuração Intestinal/patologia , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Neoplasias Ovarianas/patologia , Neoplasias Peritoneais/tratamento farmacológico , Neoplasias Peritoneais/patologia , Estudos Retrospectivos , Fatores de Risco
9.
Science ; 260(5108): 672-4, 1993 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-17812228

RESUMO

Peroxidase has been thought to be the only enzyme that oxidizes monolignol precursors to initiate lignin formation in plants. A laccase was purified from cell walls of differentiating xylem of loblolly pine and shown to coincide in time and place with lignin formation and to oxidize monolignols to dehydrogenation products in vitro. These results suggest that laccase participates in lignin biosynthesis and therefore could be an important target for genetic engineering to modify wood properties or to improve the digestibility of forage crops.

10.
Science ; 277(5323): 235-9, 1997 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-9211851

RESUMO

Novel lignin is formed in a mutant loblolly pine (Pinus taeda L.) severely depleted in cinnamyl alcohol dehydrogenase (E.C. 1.1.1.195), which converts coniferaldehyde to coniferyl alcohol, the primary lignin precursor in pines. Dihydroconiferyl alcohol, a monomer not normally associated with the lignin biosynthetic pathway, is the major component of the mutant's lignin, accounting for approximately 30 percent (versus approximately 3 percent in normal pine) of the units. The level of aldehydes, including new 2-methoxybenzaldehydes, is also increased. The mutant pines grew normally indicating that, even within a species, extensive variations in lignin composition need not disrupt the essential functions of lignin.


Assuntos
Oxirredutases do Álcool/metabolismo , Lignina/química , Oxirredutases do Álcool/deficiência , Oxirredutases do Álcool/genética , Aldeídos/análise , Lignina/biossíntese , Espectroscopia de Ressonância Magnética , Mutação , Oxirredução , Fenóis/análise , Fenóis/metabolismo , Pinus taeda , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
11.
Gynecol Oncol ; 115(3): 396-400, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19804901

RESUMO

OBJECTIVE: To determine efficacy, toxicity, and survival in patients with recurrent epithelial ovarian cancer (EOC) receiving combination of weekly paclitaxel and biweekly bevacizumab (PB). METHODS: We reviewed chemotherapy logs identifying all patients receiving combination PB. Toxicities were graded using CTCAEv3.0 criteria. Response rates (RR) were measured using RECIST criteria or by CA-125 levels per modified Rustin criteria. RR and progression-free survival (PFS) were determined and plotted using Kaplan-Meier survival analysis. RESULTS: Fifty-one patients receiving at least two cycles of chemotherapy were evaluable for survival and 55 patients receiving one cycle of PB were evaluable in toxicity analysis. The mean number of previous regimens was four. The overall median PFS was 7 months and median OS was 12 months. The overall response rate (ORR) was 60% (CR 25% and PR 35%). Median PFS for complete and partial responders were 14 and 5 months respectively. Stable disease was seen in 26% with median PFS of 6 months. Thirteen experienced treatment delays for a variety of factors. The most G3/4 toxicities were fatigue (16%), hematologic (9%) and neurotoxicity (7%). Three patients (5%) experienced bowel perforations. CONCLUSIONS: Combination of paclitaxel and bevacizumab is feasible and demonstrates an acceptable toxicity profile and a high response rate. These observations should be useful in planning future clinical trials with this combination therapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Recidiva Local de Neoplasia/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Adulto , Idoso , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Bevacizumab , Intervalo Livre de Doença , Esquema de Medicação , Feminino , Humanos , Pessoa de Meia-Idade , Paclitaxel/administração & dosagem , Paclitaxel/efeitos adversos , Estudos Retrospectivos , Taxa de Sobrevida
12.
J Microsc ; 233(1): 114-31, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19196418

RESUMO

Many kinds of neuroscience data are being acquired regarding the dynamic behaviour and phenotypic diversity of nerve cells. But as the size, complexity and numbers of 3D neuroanatomical datasets grow ever larger, the need for automated detection and analysis of individual neurons takes on greater importance. We describe here a method that detects and identifies neurons within confocal image stacks acquired from the zebrafish brainstem. The first step is to create a template that incorporates the location of all known neurons within a population - in this case the population of reticulospinal cells. Once created, the template is used in conjunction with a sequence of algorithms to determine the 3D location and identity of all fluorescent neurons in each confocal dataset. After an image registration step, neurons are segmented within the confocal image stack and subsequently localized to specific locations within the brainstem template - in many instances identifying neurons as specific, individual reticulospinal cells. This image-processing sequence is fully automated except for the initial selection of three registration points on a maximum projection image. In analysing confocal image stacks that ranged considerably in image quality, we found that this method correctly identified on average approximately 80% of the neurons (if we assume that manual detection by experts constitutes 'ground truth'). Because this identification can be generated approximately 100 times faster than manual identification, it offers a considerable time savings for the investigation of zebrafish reticulospinal neurons. In addition to its cell identification function, this protocol might also be integrated with stereological techniques to enhance quantification of neurons in larger databases. Our focus has been on zebrafish brainstem systems, but the methods described should be applicable to diverse neural architectures including retina, hippocampus and cerebral cortex.


Assuntos
Automação , Tronco Encefálico/citologia , Imageamento Tridimensional/métodos , Microscopia Confocal/métodos , Neurônios/citologia , Peixe-Zebra , Animais
13.
Neuron ; 17(6): 1145-55, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8982162

RESUMO

Although vertebrate hindbrains are segmented structures, the functional significance of the segmentation is unknown. In zebrafish, the hindbrain segments contain serially repeated classes of individually identifiable neurons. We took advantage of the transparency of larval zebrafish and used confocal calcium imaging in the intact fish to study the activity of one set of individually identified, serially homologous reticulospinal cells (the Mauthner cell, MID2cm, and MID3cm) during behavior. Behavioral studies predicted that differential activity in this set of serially homologous neurons might serve to control the directionality of the escape behavior that fish use to avoid predators. We found that the serially homologous cells are indeed activated during escapes and that the combination of cells activated depends upon the location of the sensory stimulus used to elicit the escape. The patterns of activation we observed were exactly those predicted by behavioral studies. The data suggest that duplication of ancestral hindbrain segments, and subsequent functional diversification, resulted in sets of related neurons whose activity patterns create behavioral variability.


Assuntos
Reação de Fuga/fisiologia , Rombencéfalo/fisiologia , Peixe-Zebra/fisiologia , Animais , Cálcio/fisiologia , Limiar Diferencial , Eletrofisiologia , Potenciais Evocados , Corantes Fluorescentes , Isoquinolinas , Neurônios/fisiologia , Compostos Orgânicos , Rombencéfalo/citologia , Sensação/fisiologia
14.
Int J Gynecol Cancer ; 18(1): 199-204, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17511806

RESUMO

The effect of a gynecological oncology fellow on obstetrics and gynecology resident education and training is uncertain. The objective is to assess the effect of gynecological oncology fellows on the surgical training of residents in obstetrics and gynecology. Fourth year residents in obstetrics and gynecology in the United States were identified and stratified as to the presence or absence of an oncology fellowship program. Demographics, surgical volume, procedures performed, and self-assessment of surgical proficiency were collected. Responses were compared between residency programs with and without fellowships. Responses were received from 40% of programs. Residents at programs without a fellowship more frequently operated with attendings than did residents at programs with fellows, 91% vs 77%, P= 0.016, and more frequently were responsible for complicated cases, 39% vs 22%, P < 0.0001. Over 90% of residents in both groups reported surgical training as positive and valuable; both groups reported a similar perceived lack of proficiency in radical hysterectomy and lymphadenectomy. Attitudes toward the fellows were generally positive; however, competition for cancer cases was reported by over 66% of residents from programs with fellows. While fellows are often thought of as a detracting factor to residency training, they do not appear to affect the perception of the quality of resident surgical training.


Assuntos
Bolsas de Estudo , Procedimentos Cirúrgicos em Ginecologia/educação , Ginecologia/educação , Internato e Residência , Oncologia/educação , Competência Clínica , Humanos , Estudantes de Medicina , Estados Unidos
15.
Curr Opin Neurobiol ; 7(6): 832-8, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9464974

RESUMO

Neuronal activity has recently been imaged with single-cell resolution in behaving vertebrates. This was accomplished by using fluorescent calcium indicators in conjunction with confocal or two-photon microscopy. These optical techniques, along with other new approaches for imaging synaptic activity, second messengers, and neurotransmitters and their receptors offer great promise for the study of neuronal networks at high resolution in vivo.


Assuntos
Comportamento Animal/fisiologia , Rede Nervosa/anatomia & histologia , Rede Nervosa/fisiologia , Animais , Mamíferos/fisiologia , Rede Nervosa/citologia , Neurônios/fisiologia , Peixe-Zebra
16.
Genetics ; 155(1): 337-48, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10790407

RESUMO

Inbreeding depression is important in the evolution of plant populations and mating systems. Previous studies have suggested that early-acting inbreeding depression in plants is primarily due to lethal alleles and possibly epistatic interactions. Recent advances in molecular markers now make genetic mapping a powerful tool to study the genetic architecture of inbreeding depression. We describe a genome-wide evaluation of embryonic viability loci in a selfed family of loblolly pine (Pinus taeda L.), using data from AFLP markers from an essentially complete genome map. Locus positions and effects were estimated from segregation ratios using a maximum-likelihood interval mapping procedure. We identified 19 loci showing moderately deleterious to lethal embryonic effects. These loci account for >13 lethal equivalents, greater than the average of 8.5 lethal equivalents reported for loblolly pine. Viability alleles show predominantly recessive action, although potential overdominance occurs at 3 loci. We found no evidence for epistasis in the distribution of pairwise marker correlations or in the regression of fitness on the number of markers linked to deleterious alleles. The predominant role of semilethal alleles in embryonic inbreeding depression has implications for the evolution of isolated populations and for genetic conservation and breeding programs in conifers.


Assuntos
Genoma de Planta , Cruzamentos Genéticos , Epistasia Genética , Genes Dominantes , Marcadores Genéticos , Modelos Genéticos , Pinus taeda
17.
Evolution ; 54(5): 1580-9, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11108586

RESUMO

The magnitude of fitness effects at genetic loci causing inbreeding depression at various life stages has been an important question in plant evolution. We used genetic mapping in a selfed family of loblolly pine (Pinus taeda L.) to gain insights on inbreeding depression for early growth and viability. Two quantitative trait loci (QTLs) were identified that explain much of the phenotypic variation in height growth through age 3 and may account for more than 13% inbreeding depression in this family. One of these QTLs maps to the location of cad-nl, a lignin biosynthesis mutation. Both QTLs show evidence of overdominance, although evidence for true versus pseudo-overdominance is inconclusive. Evidence of directional dominance for height growth was noted throughout the genome, suggesting that additional loci may contribute to inbreeding depression. A chlorophyll-deficiency mutation, spf did not appear to be associated with growth effects, but had significant effects on survival through age 3. Previously identified embryonic viability loci had little or no overall effect on germination, survival, or growth. Our results challenge, at least in part, the prevailing hypothesis that inbreeding depression for growth is due to alleles of small effect. However, our data support predictions that loci affecting inbreeding depression are largely stage specific.


Assuntos
Mapeamento Cromossômico , Cycadopsida/genética , Característica Quantitativa Herdável , Evolução Biológica , Clorofila/genética , Cycadopsida/crescimento & desenvolvimento , Fertilização , Ligação Genética , Mutação , Pinus taeda
18.
Biotechniques ; 30(2): 348-52, 354, 356-7, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11233604

RESUMO

Amplified fragment length polymorphism (AFLP) analysis is currently the most powerful and efficient technique for the generation of large numbers of anonymous DNA markers in plant and animal genomes. We have developed a protocol for high-throughput AFLP analysis that allows up to 70,000 polymorphic marker genotype determinations per week on a single automated DNA sequencer. This throughput is based on multiplexed PCR amplification of AFLP fragments using two different infrared dyelabeled primer combinations. The multiplexed AFLPs are resolved on a two-dye, model 4200 LI-COR automated DNA sequencer, and the digital images are scored using semi-automated scoring software specifically designed for complex AFLP banding patterns (AFLP-Quantar). Throughput is enhanced by using high-quality genomic DNA templates obtained by a 96-well DNA isolation procedure.


Assuntos
Polimorfismo Genético , Análise de Sequência de DNA , Eletroforese , Marcadores Genéticos , Genótipo , Raios Infravermelhos , Reação em Cadeia da Polimerase
19.
J Neurosci Methods ; 108(1): 97-110, 2001 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-11459623

RESUMO

Establishing a causal role between the activity of specific individual nerve cells and the behaviors they produce (or the neural computations they execute) is made difficult in vertebrate animals because of the large numbers of neurons involved. Traditional techniques for establishing causal roles, such as tract cutting and electrolytic lesions, are limited because they produce damage that affects a variety of different cell types, invariably intermingled, and often of uncertain identity. We propose here an alternative lesioning technique in which large numbers of neurons are lesioned, but the lesioned neurons are specifically identified by fluorescent labeling. We use the locomotor control system of the larval zebrafish to illustrate this approach. In this example, the technique involves injection of fluorescent dextrans into far-rostral spinal cord to label descending nerve fibers. Such injections appear to interrupt the descending nerve fibers, and therefore their accompanying locomotor control signals. This protocol is shown to produce significant behavioral deficits. Because the CNS of the larval zebrafish is transparent, the entire population of lesioned cells can be imaged in vivo and reconstructed using confocal microscopy. This large-scale lesioning technique is important, even in this relatively 'simple' vertebrate animal, because the ablation of smaller numbers of neurons, using more precise laser-ablation techniques, often fails to produce observable behavioral deficits. While this technique is most readily applied in simpler and transparent vertebrate animals, the approach is general in nature and might, in principle, be applied to any vertebrate nerve tract.


Assuntos
Axônios/efeitos dos fármacos , Axotomia/métodos , Vias Eferentes/cirurgia , Rombencéfalo/cirurgia , Medula Espinal/cirurgia , Peixe-Zebra/cirurgia , Animais , Transporte Axonal/efeitos dos fármacos , Transporte Axonal/fisiologia , Axônios/fisiologia , Axônios/ultraestrutura , Dextranos/farmacologia , Vias Eferentes/citologia , Vias Eferentes/crescimento & desenvolvimento , Corantes Fluorescentes/farmacologia , Microscopia Confocal/métodos , Microscopia de Fluorescência , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Degeneração Neural/induzido quimicamente , Rombencéfalo/citologia , Rombencéfalo/crescimento & desenvolvimento , Medula Espinal/citologia , Medula Espinal/crescimento & desenvolvimento , Natação/fisiologia , Peixe-Zebra/anatomia & histologia , Peixe-Zebra/crescimento & desenvolvimento
20.
J Neurosci Methods ; 73(1): 91-106, 1997 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-9130682

RESUMO

'Caged' neurotransmitters are molecules that are transformed to a neuroactive state by exposure to light of an appropriate wavelength and intensity. Use of these substances has centered on in vitro bath application and subsequent activation using light from lasers or flashlamps that is delivered into the preparation through microscope optics. We have tested a new and simpler method, using finely tapered fiberoptic lightguides, that promises to expand the use of caged compounds for in vitro and in vivo experimentation. We demonstrated the feasibility and flexibility of this method for caged neurotransmitter delivery using a range of ex vitro, in vitro and in vivo approaches. The degree and timing of uncaging could be controlled by manipulating the wavelength, intensity and timing of the light projected into the optical fiber. Because of the small size of the light guide and the ability to control light exposure at the source, this new method promises greater control over the spatial and temporal delivery of neuroactive substances than simple bath or iontophoretic application, and enables delivery of conventional neurotransmitters with a spatial and temporal resolution closer to that of the natural neuronal circuitry. In addition, this new method allows the application of normally labile substances, such as the free radical gas nitric oxide, by the photoconversion of photosensitive precursors.


Assuntos
Córtex Cerebral/metabolismo , Neurotransmissores/metabolismo , Óxido Nítrico/metabolismo , Estimulação Luminosa , Animais , Gatos
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