41 research outputs found

    Reliability of Nonlinear least square broken stick model in quantifying the effects of temperature and photoperiod on flowering of pigeonpea genotypes (Cajanus cajan (L.) Millsp.)

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    Temperature and photoperiod are two major environmental determinants that affect the flowering time. The information on the effect of temperature and photoperiod on flowering response in pigeonpea is limited and needs updating for new genotypes. The present study aimed to assess the reliability of the Nonlinear least square broken stick model to quantify photothermal effects in pigeonpea (Cajanus cajan (L.) Millsp.) genotypes. Data at 50 % flowering (FL) from pot, field, and temperature-controlled glasshouse experiments under eight sowing dates were analysed using regression models to describe the individual effect of temperature and photoperiod and photothermal models to quantify the combined effect. The critical photoperiod (Pce)and optimum temperature (To)predicted by the Nonlinear broken stick model for 50 % FL ranged from 12.4 - 13.4 h and 21.0 - 23.5 °C, respectively. The higher Pce reported for extra-early flowering genotype (QPL 1001) indicates that their insensitiveness to a range of photoperiod regimes compared to QPL 941 and ICP 14425 (medium duration). Further, the results also revealed that the time to 50 % FL of genotype QPL 1001 was strongly sensitive to the temperature at sub-optimal range (T < To), with warmer temperatures accelerating reproductive development. In contrast, QPL941 and ICP 14425 were sensitive to supra-optimal temperature (T > To), with flowering being delayed in warmer temperatures. The parameters (To and Pce) derived from Nonlinear least square broken stick model can be used as a proxy to identify photoperiod insensitivity in pigeopea genotypes.

    Environmental effects of ozone depletion, UV radiation and interactions with climate change : UNEP Environmental Effects Assessment Panel, update 2017

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    Atypical teratoid rhabdoid tumors: a population-based clinical outcomes study involving 174 patients from the Surveillance, Epidemiology, and End Results database (1973–2010)

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    Christine SM Lau,1,2 Krishnaraj Mahendraraj,1 Ronald S Chamberlain1–31Department of Surgery, Saint Barnabas Medical Center, Livingston, NJ, USA; 2Saint George's University School of Medicine, Grenada, West Indies; 3Department of Surgery, New Jersey Medical School, Rutgers University, Newark, NJ, USA Introduction: Atypical teratoid rhabdoid tumors (ATRTs) are rare, highly malignant embryonal tumors of the central nervous system (CNS) accounting for 20% of CNS tumors in children under the age of 3. This study examines a large cohort of ATRT patients to determine demographic, clinical, and pathologic factors which impact prognosis and survival. Methods: Demographic and clinical data were abstracted on 174 ATRT patients (171 pediatric patients age <20 and 3 adult patients age ≥20) from the Surveillance, Epidemiology, and End Results database (1973–2010). Standard statistical methodology was used. Results: A total of 174 ATRT cases (mean age of 2.84 years) were identified. ATRT had a higher incidence in males (56.3%), Caucasians (59.1%), and children <3 years of age (80.5%), P<0.001. The most common primary sites were the cerebellum (17.8%), ventricles (16.1%), and frontal lobe (12.6%). Mean overall survival was 3.2±0.4 years, while overall and cancer-specific mortality were 63.2% and 56.3%, respectively, P=0.005. Most ATRT cases were treated with surgery alone (58.0%), followed by a combination of surgery and radiation (34.3%), no treatment (6.5%), and radiation alone (1.2%). The use of combination therapy has increased significantly (16.1%) since 2005 (P<0.001), while primary surgical resection and radiation therapy rates remain relatively unchanged. The longest survival was observed among ATRT patients receiving combination therapy (5.9±0.7 years), followed by radiation alone (2.8±1.2 years), and surgery alone (1.9±0.4 years), P<0.001. Multivariable analysis identified only distant metastases (OR =4.6) as independently associated with increased mortality, whereas combination therapy (OR =0.4) was associated with reduced mortality, P<0.005. Conclusion: ATRT is a rare and highly aggressive embryonal malignancy of the CNS that presents more often as locoregional tumors >4 cm in male Caucasian children of age <3 years, involving the cerebellum, ventricles, or frontal lobe. Combination therapy significantly improves survival, and its use has been increasing since 2005. Keywords: childhood brain cancer, pediatric cancer, central nervous system, rare tumors, SEER databas

    Trends in incidence, survival, and management of uveal melanoma: a population-based study of 7,516 patients from the Surveillance, Epidemiology, and End Results database (1973–2012)

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    Krishnaraj Mahendraraj,1 Christine SM Lau,1,2 Injoon Lee,2 Ronald S Chamberlain1–3 1Department of Surgery, Saint Barnabas Medical Center, Livingston, NJ, USA; 2St George’s University School of Medicine, Grenada, West Indies; 3Department of Surgery, New Jersey Medical School, Rutgers University, Newark, NJ, USA Introduction: Uveal melanoma (UM) is the most common primary intraocular malignancy, despite comprising <5% of all melanomas. To date, relatively few case series of UM have been published. Moreover, the factors influencing survival remain largely unknown. This study sought to analyze the impact of demographics, histology, clinical presentation, and treatments on the clinical outcomes of UM in a large modern nationwide patient cohort.Methods: Demographics and clinical data were abstracted on 277,120 histologically confirmed melanoma patients from the Surveillance, Epidemiology, and End Results database between 1973 and 2012.Results: A total of 7,516 cases of UM represented 3.2% of all recorded cases of melanoma. The mean age-adjusted incidence was 5.1 per million (95% CI 4.2–6.1) and was higher in males (5.9, CI =4.4–7.6) compared to females (4.5, CI =3.3–5.8), P<0.001. UM occurred most commonly in the sixth decade of life (61.4±15) and among Caucasians (94.7%). A total of 52.3% of cases were reported in the Western US (35.7% in California). The initial diagnoses in 65.2% of cases were by histopathology, followed by clinical diagnosis (18.8%) and radiographic imaging (16.0%). The percentage of UM cases managed by surgery alone decreased by 69.4% between the 1973–1977 and 2006–2012 time periods, concomitant with a 62% increase in primary radiotherapy, P<0.001. The UM mean overall and cancer-specific 5-year relative survival rates were 79.8%±5.8% and 76%±5.3%, respectively. The mean 5-year cancer-specific survival rate (76%) remained stable during the study period between 1973 and 2012. The mean survival for patients treated with primary radiotherapy was significantly improved compared to those treated with surgery alone (15.4±0.4 vs 13.6±0.3, P<0.001). Multivariate analysis identified male sex (odds ratio [OR] 1.1, CI =1.0–1.3), age >50 years (OR 4.0, CI =3.4–4.6), distant metastases (OR 8.6, CI =4.7–15), and primary surgical treatment (OR 2.6, CI =2.0–3.3) as independently associated with increased mortality, P<0.005. Conversely, patients identified as Hispanic (OR 0.6, CI =0.5–0.8) and patients receiving radiation treatment (OR 0.5, CI =0.4–0.7) were independently associated with reduced mortality, P<0.005.Conclusion: UM remains a rare form of melanoma that occurs primarily in Caucasian patients older than 50 years. More than two-thirds of UM patients are curatively treated with primary radiotherapy as opposed to surgery, which has resulted in a significant improvement in both overall survival and cancer-specific survival. Despite this shift in management strategy, the mean 5-year cancer-specific survival rate remained relatively unchanged during the study period. Male sex, older age, distant disease, and primary surgical therapy rather than radiotherapy are associated with an increased risk of mortality. Keywords: uveal melanoma, ocular melanoma, SEER&nbsp

    Ocular melanoma-when you have seen one, you have not seen them all: a clinical outcome study from the Surveillance, Epidemiology and End Results (SEER) database (1973–2012)

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    Krishnaraj Mahendraraj,1 Sneha Shrestha,1 Christine SM Lau,1,2 Ronald S Chamberlain1–4 1Department of Surgery, Saint Barnabas Medical Center, Livingston, NJ, USA; 2Saint George’s University School of Medicine, Grenada, West Indies; 3Department of Surgery, Banner MD Anderson Cancer Center, Gilbert, AZ, USA; 4Department of Surgery, Rutgers University, New Jersey Medical School, Newark, NJ, USA Background: Ocular melanoma (OM) comprises <5% of all melanomas. Uveal melanoma (UM) is the most common subtype of OM, while conjunctival melanoma (CM) is rare and differs significantly from UM. The purpose of this study is to evaluate a large cohort of OM patients to differentiate demographic, pathologic, and clinical factors between these two neoplasms, which may affect treatment and outcomes. Methods: The Surveillance, Epidemiology, and End Results database (1973–2012) was used to extract demographic and clinical data on 8,165 OM patients (92.1% UM and 7.9% CM). Results: Both CM and UM were most prevalent among Caucasian males in the seventh decade of life. UM patients presented more often with localized disease (90.9% vs 81.2, P<0.01). Surgery (42.8%), radiation (43.0%), or combined surgery and radiation (7.0%) were used in the treatment of UM, while CM was treated almost exclusively with surgery (88.7%). Mean overall survival was longer (15.4 vs 14.6 years; P<0.01) and mortality rates were lower in patients (38.8% vs 46.1%; P<0.01) with CM. Conclusion: Despite presenting with more advanced disease than UM, CM is associated with an increased overall survival. Surgery is the primary therapy for CM, whereas radiotherapy is the primary therapy for UM and is associated with prolonged survival. Keywords: ocular melanoma, uveal melanoma, conjunctival melanoma, SEE
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