RESUMO
Seed oil from flax (Linum usitatissimum) is enriched in α-linolenic acid (ALA; 18:3Δ9cis,12cis,15cis ), but the biochemical processes underlying the enrichment of flax seed oil with this polyunsaturated fatty acid are not fully elucidated. Here, a potential process involving the catalytic actions of long-chain acyl-CoA synthetase (LACS) and diacylglycerol acyltransferase (DGAT) is proposed for ALA enrichment in triacylglycerol (TAG). LACS catalyzes the ATP-dependent activation of free fatty acid to form acyl-CoA, which in turn may serve as an acyl-donor in the DGAT-catalyzed reaction leading to TAG. To test this hypothesis, flax LACS and DGAT cDNAs were functionally expressed in Saccharomyces cerevisiae strains to probe their possible involvement in the enrichment of TAG with ALA. Among the identified flax LACSs, LuLACS8A exhibited significantly enhanced specificity for ALA over oleic acid (18:1Δ9cis ) or linoleic acid (18:2Δ9cis,12cis ). Enhanced α-linolenoyl-CoA specificity was also observed in the enzymatic assay of flax DGAT2 (LuDGAT2-3), which displayed â¼20 times increased preference toward α-linolenoyl-CoA over oleoyl-CoA. Moreover, when LuLACS8A and LuDGAT2-3 were co-expressed in yeast, both in vitro and in vivo experiments indicated that the ALA-containing TAG enrichment process was operative between LuLACS8A- and LuDGAT2-3-catalyzed reactions. Overall, the results support the hypothesis that the cooperation between the reactions catalyzed by LACS8 and DGAT2 may represent a route to enrich ALA production in the flax seed oil.
Assuntos
Acil Coenzima A/metabolismo , Coenzima A Ligases/metabolismo , Diacilglicerol O-Aciltransferase/metabolismo , Linho/metabolismo , Óleo de Semente do Linho/metabolismo , Ácido Oleico/metabolismo , Ácido alfa-Linolênico/metabolismo , Sequência de Aminoácidos , Homologia de Sequência , Especificidade por SubstratoRESUMO
The shapes of leaves are dynamic, changing over evolutionary time between species, within a single plant producing different shaped leaves at successive nodes, during the development of a single leaf as it allometrically expands, and in response to the environment. Notably, strong correlations between the dissection and size of leaves with temperature and precipitation exist in both the paleorecord and extant populations. Yet, a morphometric model integrating evolutionary, developmental, and environmental effects on leaf shape is lacking. Here, we continue a morphometric analysis of >5,500 leaves representing 270 grapevines of multiple Vitis species between two growing seasons. Leaves are paired one-to-one and vine-to-vine accounting for developmental context, between growing seasons. Linear discriminant analysis reveals shape features that specifically define growing season, regardless of species or developmental context. The shape feature, a more pronounced distal sinus, is associated with the colder, drier growing season, consistent with patterns observed in the paleorecord. We discuss the implications of such plasticity in a long-lived woody perennial, such as grapevine (Vitis spp.), with respect to the evolution and functionality of plant morphology and changes in climate.
Assuntos
Clima , Modelos Biológicos , Folhas de Planta/fisiologia , Vitis/fisiologia , Evolução Biológica , Meio Ambiente , Chuva , Estações do Ano , Especificidade da Espécie , Temperatura , Vitis/classificaçãoRESUMO
BACKGROUND: The presence of Gleason pattern 5 (GP5) at radical prostatectomy (RP) has been associated with worse clinical outcome; however, this pathologic variable has not been assessed in patients receiving salvage radiation therapy (SRT) after a rising prostate-specific antigen level. METHODS: A total of 575 patients who underwent primary RP for localized prostate cancer and subsequently received SRT at a tertiary medical institution were reviewed retrospectively. Primary outcomes of interest were biochemical failure (BF), distant metastasis (DM), and prostate cancer-specific mortality (PCSM), which were assessed via univariate analysis and Fine and Grays competing risks multivariate models. RESULTS: On pathologic evaluation, 563 (98%) patients had a documented Gleason score (GS). The median follow-up post-SRT was 56.7 months. A total of 60 (10.7%) patients had primary, secondary, or tertiary GP5. On univariate analysis, the presence of GP5 was prognostic for BF (hazard ratio [HR] 3.3; P < .0001), DM (HR:11.1, P < .0001), and PCSM (HR:8.8, P < .0001). Restratification of the Gleason score to include GP5 as a distinct entity resulted in improved prognostic capability. Patients with GP5 had clinically worse outcomes than patients with GS8(4+4). On multivariate analysis, the presence of GP5 was the most adverse pathologic predictor of BF (HR 2.9; P < .0001), DM (HR 14.8; P < .0001), and PCSM (HR 5.7; P < .0001). CONCLUSION: In the setting of SRT for prostate cancer, the presence of GP5 is a critical pathologic predictor of BF, DM, and PCSM. Traditional GS risk stratification fails to fully utilize the prognostic capabilities of individual Gleason patterns among men receiving SRT post-RP.
Assuntos
Neoplasias da Próstata/patologia , Neoplasias da Próstata/radioterapia , Idoso , Androgênios/deficiência , Biópsia por Agulha , Humanos , Calicreínas , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Metástase Neoplásica , Recidiva Local de Neoplasia/patologia , Valor Preditivo dos Testes , Antígeno Prostático Específico , Prostatectomia/métodos , Neoplasias da Próstata/cirurgia , Estudos Retrospectivos , Terapia de Salvação , Análise de SobrevidaRESUMO
INTRODUCTION: Naloxone reverses opioid overdose, but it is not universally prescribed. With increases in opioid-related emergency department visits, emergency medicine providers are in a unique position to identify and treat opioid-related injury, but little is known about their attitudes and practices around naloxone prescribing. We hypothesized that emergency medicine providers would identify multifactorial barriers to naloxone prescribing and report varying levels of naloxone-prescribing behaviors. METHODS: A survey designed to assess attitudes and behaviors regarding naloxone prescribing practices was emailed to all prescribing providers at an urban academic emergency department. Descriptive and summary statistics were performed. RESULTS: The response rate was 29% (36/124). Nearly all respondents (94%) expressed openness to prescribing naloxone from the emergency department, but only 58% had actually done so. Most (92%) believed that patients would benefit from greater access to naloxone, however 31% also believed that opioid use would increase as access to naloxone increases. Time was the most frequently identified barrier (39%) to prescribing, followed by a perceived inability to properly educate patients on naloxone use (25%). CONCLUSIONS: In this study of emergency medicine providers, the majority of respondents were amendable to prescribing naloxone, yet almost half had not done so and some believed that doing so would increase opioid use. Barriers included time constraints and perceived self-reported knowledge deficits regarding naloxone education. More information is needed to gauge the impact of individual barriers to prescribing naloxone, but these findings may provide information that can be incorporated in provider education and potential clinical pathways designed to increase naloxone prescribing.
Assuntos
Overdose de Drogas , Prescrições de Medicamentos , Serviço Hospitalar de Emergência , Naloxona , Antagonistas de Entorpecentes , Naloxona/uso terapêutico , Overdose de Drogas/tratamento farmacológico , Antagonistas de Entorpecentes/uso terapêutico , Transtornos Relacionados ao Uso de Opioides/tratamento farmacológico , Analgésicos Opioides , Conhecimentos, Atitudes e Prática em Saúde , Medicamentos sob PrescriçãoRESUMO
OBJECTIVES: This study assessed the immediate effect of unilateral posterior-anterior lumbar mobilisations on trunk and lower limb flexibility in asymptomatic individuals. STUDY DESIGN: Randomised cross-over trial. PARTICIPANTS: Twenty-seven participants (age = 26.0 years ±6.4) with no current or recent history of lower back or leg pain/surgery completed the study. MAIN OUTCOME MEASURES: Participants attended two sessions, receiving either grade 3 ('treatment') or grade 1 ('sham') unilateral spinal mobilisations. Outcome measures (modified-modified Schober's test [MMST], ninety-ninety test [NNT], and passive straight-leg raise [PSLR]) were assessed immediately before and after (post-1 and post-2) the intervention. An instrumented hand-held dynamometer was used to measure the change in NNT and PSLR joint angle (deg) and passive stiffness (Nm/deg) pre- and post-intervention. RESULTS: The mean change in PSLR angle at the first (P1) and maximal (P2) point of discomfort following the treatment was 4.8° and 5.5°, and 5.6° and 5.7°, larger than the sham at post-1 and post-2, respectively. There was no effect of the treatment on the PSLR at P1 or P2 for the contralateral limb at either timepoint. There was no effect of the treatment on MMST distance, NNT angle or passive stiffness, or PSLR passive stiffness, for either limb. CONCLUSIONS: Immediate effects of unilateral posterior-anterior lumbar mobilisations in asymptomatic individuals are isolated to treatment side and limited to a small increase in PSLR range, with no change in lumbar motion or the NNT test.
Assuntos
Perna (Membro) , Extremidade Inferior , Humanos , Adulto , Estudos Cross-Over , Região Lombossacral , Dor , Amplitude de Movimento ArticularRESUMO
BACKGROUND: Limited data exist to guide the use of androgen deprivation therapy (ADT) for men treated with radiation therapy (RT) after radical prostatectomy (RP). The optimal duration of ADT in this setting is unknown. OBJECTIVE: To determine if the duration of ADT influences clinical outcomes for men receiving post-RP RT. DESIGN, SETTING, AND PARTICIPANTS: A total of 680 men who received adjuvant radiation therapy (n=105) or salvage radiation therapy (n=575) between 1986 and 2010 at a single tertiary care institution were reviewed retrospectively. Median follow-up post-RT was 57.8 mo. INTERVENTION: RT was delivered using three-dimensional conformal or intensity-modulated RT in 1.8-Gy fractions. For patients treated with ADT, >80% were treated with a gonadotropin-releasing hormone agonist with or without a nonsteroidal antiandrogen. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Biochemical failure (BF), distant metastasis (DM), prostate cancer-specific mortality (PCSM), and overall mortality were assessed using Kaplan-Meier analysis and propensity score analysis. RESULTS AND LIMITATIONS: Overall, 144 patients (21%) received ADT with post-RP RT, most of whom had high-risk disease features such as Gleason score 8-10, seminal vesicle invasion, or pre-RT prostate-specific antigen >1 ng/ml. Median ADT duration was 12 mo (interquartile range: 6.0-23.7). Patients who received <12 mo of ADT had an association with increased BF (hazard ratio [HR]: 2.27; p=0.003) and DM (HR: 2.48; p=0.03) compared with patients receiving ≥12 mo of ADT. The 5-yr rates of DM were 6.0% and 23% for ≥12 and <12 mo of ADT, respectively. On propensity score analysis controlling for pretreatment and treatment-related factors, each month of ADT was associated with a decreased risk for BF (HR: 0.95; p=0.0004), DM (HR: 0.88; p=0.0004), and PCSM (HR: 0.90; p=0.037). These findings are limited by the retrospective nature of our analysis. CONCLUSIONS: For men with high-risk disease features receiving ADT with post-RP RT, the duration of ADT is associated with clinical outcomes. Our findings suggest that for these men an extended course of ADT ≥12 mo may be preferable. Validation of our findings is needed. PATIENT SUMMARY: We evaluated outcomes for men with high-risk disease features treated with androgen deprivation therapy (ADT) and radiotherapy after radical prostatectomy. Longer durations of ADT resulted in improved patient outcomes.
Assuntos
Antagonistas de Androgênios/administração & dosagem , Antineoplásicos/administração & dosagem , Neoplasias da Próstata/patologia , Neoplasias da Próstata/terapia , Radioterapia de Intensidade Modulada , Idoso , Quimioterapia Adjuvante , Hormônio Liberador de Gonadotropina/agonistas , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Metástase Neoplásica , Estadiamento de Neoplasias , Pontuação de Propensão , Antígeno Prostático Específico/sangue , Prostatectomia , Neoplasias da Próstata/sangue , Radioterapia Adjuvante , Estudos Retrospectivos , Terapia de Salvação , Taxa de SobrevidaRESUMO
PURPOSE: Little is known regarding the prognostic capability of prostate-specific antigen (PSA) nadir (nPSA) and time to nPSA (TnPSA) following salvage radiation therapy (SRT) for biochemical failure (BF) postradical prostatectomy (RP). We sought to assess their prognostic significance in this setting. METHODS AND MATERIALS: A total of 448 patients who received SRT without androgen deprivation therapy at a single academic institution were included in this retrospective analysis. Univariate analysis and multivariate Cox proportional hazards models were used to assess BF, distant metastasis (DM), prostate cancer-specific death (PCSD), and overall survival (OS). A prognostic nomogram incorporating nPSA and TnPSA was developed and validated in randomly allocated training and validation cohorts. RESULTS: Median follow-up post-SRT was 64 months. Median nPSA and TnPSA were undetectable and 6.7 months, respectively. On univariate analysis, a detectable nPSA (P < .01) and TnPSA <6 months (P < .01) were predictive of all outcomes. In a training cohort, a 14-point nomogram incorporating detectable nPSA, TnPSA, Gleason score, pre-radiation therapy PSA, and seminal vesicle invasion predicted BF (hazard ratio[HR], 1.4; P < .0001), DM (HR, 1.3; P < .0001), PCSD (HR, 1.3; P < .0001), and decreased OS (HR, 1.2; P < .0001). Adding nPSA and TnPSA improved the prognostic value of the nomogram compared to using clinical predictors only. The nomogram was evaluated in a validation cohort where it was predictive of BF (c-index = 0.77), DM (0.73), and PCSD (0.69). CONCLUSIONS: Patients with a detectable nPSA also having a TnPSA <6 months post-SRT are at high-risk for DM, PCSD, and decreased OS. These patients are unlikely to have clinically localized disease and should be considered for initiation of systemic therapies.
Assuntos
Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue , Neoplasias da Próstata/radioterapia , Terapia de Salvação/métodos , Idoso , Análise de Variância , Humanos , Masculino , Pessoa de Meia-Idade , Prostatectomia , Neoplasias da Próstata/patologia , Reprodutibilidade dos Testes , Estudos Retrospectivos , Fatores de Risco , Análise de SobrevidaRESUMO
PURPOSE: To investigate the utility of the interval to biochemical failure (IBF) after salvage radiation therapy (SRT) after radical prostatectomy (RP) for prostate cancer as a surrogate endpoint for distant metastasis (DM), prostate cancer-specific mortality (PCSM), and overall mortality (OM). METHODS AND MATERIALS: A retrospective analysis of 575 patients treated with SRT after RP from a single institution. Of those, 250 patients experienced biochemical failure (BF), with the IBF defined as the time from commencement of SRT to BF. The IBF was evaluated by Kaplan-Meier and Cox proportional hazards models for its association with DM, PCSM, and OM. RESULTS: The median follow-up time was 85 (interquartile range [IQR] 49.8-121.1) months, with a median IBF of 16.8 (IQR, 8.5-37.1) months. With a cutoff time of 18 months, as previously used, 129 (52%) of patients had IBF ≤18 months. There were no differences among any clinical or pathologic features between those with IBF ≤ and those with IBF >18 months. On log-rank analysis, IBF ≤18 months was prognostic for increased DM (P<.0001, HR 4.9, 95% CI 3.2-7.4), PCSM (P<.0001, HR 4.1, 95% CI 2.4-7.1), and OM (P<.0001, HR 2.7, 95% CI 1.7-4.1). Cox proportional hazards models with adjustment for other clinical variables demonstrated that IBF was independently prognostic for DM (P<.001, HR 4.9), PCSM (P<.0001, HR 4.0), and OM (P<.0001, HR 2.7). IBF showed minimal change in performance regardless of androgen deprivation therapy (ADT) use. CONCLUSION: After SRT, a short IBF can be used for early identification of patients who are most likely to experience progression to DM, PCSM, and OM. IBF ≤18 months may be useful in clinical practice or as an endpoint for clinical trials.
Assuntos
Antígeno Prostático Específico/sangue , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/radioterapia , Terapia de Salvação/mortalidade , Idoso , Análise de Variância , Antagonistas de Androgênios/uso terapêutico , Causas de Morte , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Prostatectomia , Neoplasias da Próstata/sangue , Neoplasias da Próstata/patologia , Radioterapia Conformacional , Estudos Retrospectivos , Fatores de Tempo , Falha de TratamentoRESUMO
PURPOSE: To investigate the maximum tumor diameter (MTD) of the dominant prostate cancer nodule in the radical prostatectomy specimen as a prognostic factor for outcome in patients treated with salvage external beam radiation therapy (SRT) for a rising prostate-specific antigen (PSA) value after radical prostatectomy. METHODS AND MATERIALS: From an institutional cohort of 575 patients treated with SRT, data on MTD were retrospectively collected. The impact of MTD on biochemical failure (BF), metastasis, and prostate cancer-specific mortality (PCSM) was assessed on univariate and multivariate analysis using Kaplan-Meier and Cox proportional hazards models. RESULTS: In the 173 patients with MTD data available, median follow-up was 77 months (interquartile range, 47-104 months) after SRT, and median MTD was 18 mm (interquartile range, 13-22 mm). Increasing MTD correlated with increasing pT stage, Gleason score, presence of seminal vesicle invasion, and lymph node invasion. Receiver operating characteristic curve analysis identified MTD of >14 mm to be the optimal cut-point. On univariate analysis, MTD >14 mm was associated with an increased risk of BF (P=.02, hazard ratio [HR] 1.8, 95% confidence interval [CI] 1.2-2.8), metastasis (P=.002, HR 4.0, 95% CI 2.1-7.5), and PCSM (P=.02, HR 8.0, 95% CI 2.9-21.8). On multivariate analysis MTD >14 mm remained associated with increased BF (P=.02, HR 1.9, 95% CI 1.1-3.2), metastasis (P=.02, HR 3.4, 95% CI 1.2-9.2), and PCSM (P=.05, HR 9.7, 95% CI 1.0-92.4), independent of extracapsular extension, seminal vesicle invasion, positive surgical margins, pre-RT PSA value, Gleason score, and pre-RT PSA doubling time. CONCLUSIONS: For patients treated with SRT for a rising PSA value after prostatectomy, MTD at time of radical prostatectomy is independently associated with BF, metastasis, and PCSM. Maximum tumor diameter should be incorporated into clinical decision making and future clinical risk assessment tools for those patients receiving SRT.
Assuntos
Antígeno Prostático Específico/sangue , Prostatectomia/métodos , Neoplasias da Próstata/radioterapia , Terapia de Salvação/métodos , Carga Tumoral , Idoso , Análise de Variância , Humanos , Linfonodos/patologia , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Invasividade Neoplásica , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/radioterapia , Estadiamento de Neoplasias , Prognóstico , Prostatectomia/mortalidade , Neoplasias da Próstata/sangue , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/patologia , Neoplasias da Próstata/cirurgia , Curva ROC , Estudos Retrospectivos , Terapia de Salvação/mortalidade , Glândulas Seminais/patologiaRESUMO
BACKGROUND: The ideal prostate-specific antigen (PSA) doubling time (PSADT) threshold for identifying patients at high-risk for poor clinical outcome following salvage radiation therapy (SRT) has not been well established. We sought to assess what PSADT threshold is most clinically prognostic in this setting. METHODS: 575 patients who received SRT at a single institution for biochemical recurrence after radical prostatectomy were retrospectively reviewed. We assessed the impact of pre-SRT PSADT on biochemical failure (BF), distant metastasis (DM), prostate cancer-specific mortality (PCSM), and overall mortality (OM). Kaplan-Meier methods, hazard ratio (HR) assessment, and Cox Proportional Hazard models were used to assess the discriminatory ability of various PSADT thresholds. RESULTS: Sufficient data to calculate PSADTs were available for 277 patients. PSADT was prognostic for BF, DM, PCSM, and OM on univariate analysis regardless of threshold. HR assessment identified 6 months as a strong threshold. No statistically significant difference was observed in BF, DM, PCSM, or OM between patients with PSADT <3 (n=40) and 3-6 months (n=61) or between 6-10 (n=62) and >10 months (n=114). However significant differences were seen in BF (HR:2.2, [95%CI: 1.4-3.5], p<0.01) and DM (HR:2.2, [95%CI: 1.2-4.3], p=0.02) between a PSADT of 3-6 and 6-10 months. On multivariate analysis a PSADT <6 months predicted BF (HR:2.0, [95%CI: 1.4-2.9], p=0.0001), DM (HR:2.0, [95%CI: 1.2-3.4], p=0.01), and PCSM (HR:2.6, [95%CI: 1.1-5.9], p=0.02). CONCLUSIONS: A pre-SRT PSADT <6 months was a strong predictor of outcomes in our data set, including PCSM. The most common nomogram for SRT uses a 10-month PSADT threshold for assigning points used to assess BF following SRT. If validated, our findings suggest that a PSADT threshold of <6 months should be considered for stratification of patients in future clinical trials in this setting.