103 research outputs found
Analyses of factors influencing the population dynamics of cereal aphids and their relevance to model extensions
Aphids annually infest winter wheat, Triticum aestivum L., in late spring and early summer in Central Europe, but densities leading to strong yield losses are reached only occasionally (Basedow et al., 1994). Three aphid species, Sitobion avenae Fabr., Metopolophium dirhodum Walk. and R. padi L., usually occur in cereal crops with increasing densities from late spring onwards (Basedow et al., 1994). Modelling population levels of cereal aphids is a key tool in integrated pest management for winter wheat. Over the last 30 years, considerable efforts have been made to investigate the population dynamics of aphids (DeWit and Rabbinge, 1979; Entwistle and Dixon, 1987). In Central Europe to date, two models have attained greater importance in late spring: LAUS (Friesland, 1986) and GETLAUS01 (Gosselke et al., 2001). The first one estimates the population level of S. avenae in spring in winter wheat fields and has obtained regional significance in practical plant protection. In contrast, the model GETLAUS01 is a scientific model, not designed for practical plant protection. It describes in great detail the population dynamics of S. avenae, R. padi and M. dirhodum. Both models have been improved over time and extended with several factors, e.g. by including the effects of antagonists, fertilisation, crop density, plant protection agents and meteorological parameters on population development. The objective of this study was to analyse the following three factors in terms of their impact on population and migration characteristics: cultivar, proximity between winter and summer hosts and migration (according to meteorological parameters).Getreideblattläuse (Hemiptera: Aphididae) sind die bedeutendsten Schädlinge von Winterweizen im Frühjahr und Sommer. Sie führen jedoch nur zu signifikanten Ertragsausfällen, wenn biotische und abiotische Faktoren ein optimales Populationswachstum erlauben. Einige dieser Faktoren sind bereits in Simulationsmodellen berücksichtigt. In der vorliegenden Arbeit wurden Sorteneinflüsse, die Nähe von Winter- zu Sommerwirten und meteorologische Parameter bezüglich der Migrations- und Populationsentwicklung als weitere mögliche Faktoren im Hinblick auf Modellerweiterungen untersucht. 8 Winterweizensorten zeigten weder bezüglich der Entwicklung von Nachkommen (in Klippkäfigen, BBCH-Stadium 32 und 69), noch während der Erstbesiedelungsphase von geflügelten Getreideblattläusen (Ende Mai, Anfang Juni) bedeutende Unterschiede. Die Nähe von Winter- zu Sommerwirten beeinflusste in unterschiedlicher Weise den Populationsaufbau der wirtswechselnden Arten im Winterweizen. In Jahren mit hoher Populationsentwicklung auf den Winterwirten konnte nur für Rhopalosiphum padi L. signifikant erhöhte Populationsdichten im Winterweizen in nächster Nähe zu Prunus padus L. festgestellt werden. Die frühe Migration wurde anhand von Saugfallendaten verschiedener Standorte der letzten Jahre untersucht. Das Erstauftreten von R. padi (1. Fänge in Saugfallen) zeigte sich dabei recht konstant am 13. Mai eines Jahres. Die Beziehungen zwischen den weiteren Migrationsereignissen und meteorologischen Parametern waren jedoch eher schwach ausgeprägt (R²<0,21, p=0,01); wobei hier Globalstrahlung (R²=0,21), Temperatur (R²=0,18) und Windgeschwindigkeit (R²=0,14) die deutlichsten Beziehungen zeigten
Angiogenic inflammation and formation of necrosis in the tumor microenvironment influence patient survival after radical surgery for de novo hepatocellular carcinoma in non-cirrhosis
BACKGROUND:
Tumor escape mechanisms mediated in the tumor microenvironment can significantly reduce the capacity of the anti-tumor function of the immune system. TIE2-expressing monocytes (TEMs), related angiopoietins, and tumor necrosis are considered to have a key role in this process. We aimed to investigate the abundance and clinical significance of these biomarkers in hepatocellular carcinoma (HCC).
METHODS:
In this retrospective study, 58 HCC patients received surgery with a curative intent. The abundance of TEMs, angiopoietin-1 and -2 were detected in tumor specimens of the HCC patients (n = 58), and together with the occurrence of histologic tumor necrosis, were associated with established clinicopathological characteristics and survival.
RESULTS:
Patients with HCC characterized by necrosis and TEMs revealed reduced both overall survival and recurrence-free survival (all p < 0.05). Angiopoietins and TEMs were associated with metastatic and recurrent HCC. Furthermore, the formation of histologic tumor necrosis was associated with advanced tumor stage and density of TEMs (all p < 0.05).
CONCLUSIONS:
Histologic tumor necrosis, TEMs, and related angiopoietins were associated with multiple HCC parameters and patient survival. The tumor necrosis-TEM-angiopoietin axis may offer a novel diagnostic modality to predict patient outcome after surgery for HCC
Prognostic Relevance of the Eighth Edition of TNM Classification for Resected Perihilar Cholangiocarcinoma
Objectives: In our study, we evaluated and compared the prognostic value and performance of the 6th, 7th, and 8th editions of the American Joint Committee on Cancer (AJCC) staging system in patients undergoing surgery for perihilar cholangiocarcinoma (PHC). Methods: Patients undergoing liver surgery with curative intention for PHC between 2002 and 2019 were identified from a prospective database. Histopathological parameters and stage of the PHC were assessed according to the 6th, 7th, and 8th editions of the tumor node metastasis (TNM) classification. The prognostic accuracy between staging systems was compared using the area under the receiver operating characteristic curve (AUC) model. Results: Data for a total of 95 patients undergoing liver resection for PHC were analyzed. The median overall survival time was 21 months (95% CI 8.1–33.9), and the three- and five-year survival rates were 46.1% and 36.2%, respectively. Staging according to the 8th edition vs. the 7th edition resulted in the reclassification of 25 patients (26.3%). The log-rank p-values for the 7th and 8th editions were highly statistically significant (p ≤ 0.01) compared to the 6th edition (p = 0.035). The AJCC 8th edition staging system showed a trend to better discrimination, with an AUC of 0.69 (95% CI: 0.52–0.84) compared to 0.61 (95% CI: 0.51–0.73) for the 7th edition. Multivariate survival analysis revealed male gender, age >65 years, positive resection margins, presence of distant metastases, poorly tumor differentiation, and lymph node involvement, such as no caudate lobe resection, as independent predictors of poor survival (p < 0.05). Conclusions: In the current study, the newly released 8th edition of AJCC staging system showed no significant benefit compared to the previous 7th edition in predicting the prognosis of patients undergoing liver resection for perihilar cholangiocarcinoma. Further research may help to improve the prognostic value of the AJCC staging system for PHC—for instance, by identifying new prognostic markers or staging criteria, which may improve that individual patient’s outcome
Impact of Body Mass Index on Tumor Recurrence in Patients Undergoing Liver Resection for Perihilar Cholangiocarcinoma (pCCA)
Background: The association of body mass index (BMI) and long-term prognosis and outcome of patients with perihilar cholangiocarcinoma (pCCA) has not been well defined. The aim of this study was to evaluate clinicopathologic and oncologic outcomes with pCCA undergoing resection, according to their BMI. Methods: Patients undergoing liver resection in curative intention for pCCA at a tertiary German hepatobiliary (HPB) center were identified from a prospective database. Patients were classified as normal weight (BMI 18.5–24.9 kg/m2), overweight (BMI 25.0–29.9 kg/m2) and obese (>30 kg/m2) according to their BMI. Impact of clinical and histo-pathological characteristics on recurrence-free survival (RFS) were assessed using Cox proportional hazard regression analysis among patients of all BMI groups. Results: Among a total of 95 patients undergoing liver resection in curative intention for pCCA in the analytic cohort, 48 patients (50.5%) had normal weight, 33 (34.7%) were overweight and 14 patients (14.7%) were obese. After a median follow-up of 4.3 ± 2.9 years, recurrence was observed in totally 53 patients (56%). The cumulative recurrence probability was higher in obese and overweight patients than normal weight patients (5-year recurrence rate: obese: 82% versus overweight: 81% versus normal weight: 58% at 5 years; p = 0.02). Totally, 1-, 3-, 5- and 10-year recurrence-free survival rates were 68.5%, 44.6%, 28.9% and 13%, respectively. On multivariable analysis, increased BMI (HR 1.08, 95% CI: 1.01–1.16; p = 0.021), poor/moderate tumor differentiation (HR 2.49, 95% CI: 1.2–5.2; p = 0.014), positive lymph node status (HR 2.01, 95% CI: 1.11–3.65; p = 0.021), positive resection margins (HR 1.89, 95% CI:1.02–3.4; p = 0.019) and positive perineural invasion (HR 2.92, 95% CI: 1.02–8.3; p = 0.045) were independent prognostic risk factors for inferior RFS. Conclusion: Our study shows that a high BMI is significantly associated with an increased risk of recurrence after liver resection in curative intention for pCCA. This factor should be considered in future studies to better predict patient’s individual prognosis and outcome based on their BMI
Influence of Multiple Donor Renal Arteries on the Outcome and Graft Survival in Deceased Donor Kidney Transplantation
Aim: Complex arterial reconstruction in kidney transplantation (KT) using kidneys from deceased donors (DD) warrants additional study since little is known about the effects on the mid- and long-term outcome and graft survival. Methods: A total of 451 patients receiving deceased donor KT in our department between 1993 and 2017 were included in our study. Patients were divided into three groups according to the number of arteries and anastomosis: (A) 1 renal artery, 1 arterial anastomosis (N = 369); (B) >1 renal artery, 1 arterial anastomosis (N = 47); and (C) >1 renal artery, >1 arterial anastomosis (N = 35). Furthermore, the influence of localization of the arterial anastomosis (common iliac artery (CIA), versus non-CIA) was analyzed. Clinicopathological characteristics, outcome, and graft and patient survival of all groups were compared retrospectively. Results: With growing vascular complexity, the time of warm ischemia increased significantly (groups A, B, and C: 40 ± 19 min, 45 ± 19 min, and 50 ± 17 min, respectively; p = 0.006). Furthermore, the duration of operation was prolonged, although this did not reach significance (groups A, B, and C: 175 ± 98 min, 180 ± 35 min, and 210 ± 43 min, respectively; p = 0.352). There were no significant differences regarding surgical complications, post-transplant kidney function (delayed graft function, initial non-function, episodes of acute rejection), or long-term graft survival. Regarding the localization of the arterial anastomosis, non-CIA was an independent prognostic factor for deep vein thrombosis in multivariate analysis (CIA versus non-CIA: OR 11.551; 95% CI, 1.218–109.554; p = 0.033). Conclusion: Multiple-donor renal arteries should not be considered a contraindication to deceased KT, as morbidity rates and long-term outcomes seem to be comparable with grafts with single arteries and less complex anastomoses
The value of hepatic resection in metastasic renal cancer in the era of Tyrosinkinase Inhibitor Therapy
Background: The value of liver-directed therapy (LDT) in patients with metastasic renal cell carcinoma (MRCC) is still an active field of research, particularly in the era of tyrosinkinase inhibitor (TKI) therapy. Methods: The records of 35 patients with MRCC undergoing LDT of metastasic liver lesions between 1992 and 2015 were retrospectively analyzed. Immediate postoperative TKI was given in a subgroup of patients after LDT for metastasic lesions. Uni- and multivariate models were applied to assess overall survival (OS), progression-free survival (PFS) and disease-free survival (DFS). Results: Following primary tumor (renal cell cancer) resection and LDT, respectively, median OS was better for a total of 16 patients (41 %) receiving immediate postoperative TKI with 151 and 98 months, when compared to patients without TKI therapy with 61 (p = 0.003) and 40 months (p = 0.032). Immediate postoperative TKI was associated with better median PFS (47 months versus 19 months; p = 0.023), whereas in DFS only a trend was observed (51 months versus 19 months; p = 0.110). Conclusions: LDT should be considered as a suitable additive tool in the era of TKI therapy of MRCC to the liver. In this context, postoperative TKI therapy seems to be associated with better OS and PFS, but not DFS
Early prediction of survival after open surgical repair of ruptured abdominal aortic aneurysms
Background: Scoring models are widely established in the intensive care unit (ICU). However, the importance in patients with ruptured abdominal aortic aneurysm (RAAA) remains unclear. Our aim was to analyze scoring systems as predictors of survival in patients undergoing open surgical repair (OSR) for RAAA. Methods: This is a retrospective study in critically ill patients in a surgical ICU at a university hospital. Sixty-eight patients with RAAA were treated between February 2005 and June 2013. Serial measurements of Sequential Organ Failure Assessment score (SOFA), Simplified Acute Physiology Score II (SAPS II) and Simplified Therapeutic Intervention Scoring System-28 (TISS-28) were evaluated with respect to in-hospital mortality. Eleven patients had to be excluded from this study because 6 underwent endovascular repair and 5 died before they could be admitted to the ICU. Results: All patients underwent OSR. The initial, highest, and mean of SOFA and SAPS II scores correlated significant with in-hospital mortality. In contrast, TISS-28 was inferior and showed a smaller area under the receiver operating curve. The cut-off point for SOFA showed the best performance in terms of sensitivity and specificity. An initial SOFA score below 9 predicted an in-hospital mortality of 16.2% (95% CI, 4.3–28.1) and a score above 9 predicted an in-hospital mortality of 73.7% (95% CI, 53.8–93.5, p 45), the in-hospital mortality rate was 85.7% (95% CI, 67.4–100, p < 0.01) versus 31.6% (95% CI, 10.7–52.5, p = 0.01) when it decreased. On multiple regression analysis, only the mean of the SOFA score showed a significant predictive capacity with regards to mortality (odds ratio 1.77; 95% CI, 1.19–2.64; p < 0.01). Conclusion: SOFA and SAPS II scores were able to predict in-hospital mortality in RAAA within 48 h after OSR. According to cut-off points, an increase or decrease in SOFA and SAPS II scores improved sensitivity and specificity
Influence of Intraoperative Hemodynamic Parameters on Outcome in Simultaneous Pancreas–Kidney Transplant Recipient
Objectives: Adequate organ perfusion, as well as appropriate blood pressure levels at the time of unclamping, is crucial for early and long-term graft function and outcome in simultaneous pancreas–kidney transplantation (SPKT). However, the optimal intraoperative mean arterial pressure (MAP) level has not well been defined. Methods: From a prospectively collected database, the medical data of 105 patients undergoing SPKT at our center were retrospectively analyzed. A receiver operating characteristic (ROC) analysis was preliminarily performed for optimal cut-off value for MAP at reperfusion, to predict early pancreatic graft function. Due to these results, we divided the patients according to their MAP values at reperfusion into 91 mmHg (n = 58 patients) groups. Clinicopathological characteristics and outcomes, as well as early graft function and long-term survival, were retrospectively analyzed. Results: Donor and recipient characteristics were comparable between both groups. Rates of postoperative complications were significantly higher in the 91 mmHg group (vascular thrombosis of the pancreas: 7 (14%) versus 2 (3%); p = 0.03; pancreatitis/intraabdominal abscess: 10 (21%) versus 4 (7%); p = 0.03; renal delayed graft function (DGF): 11 (23%) versus 5 (9%); p = 0.03; postreperfusion urine output: 106 ± 50 mL versus 195 ± 45 mL; p = 0.04). There were no significant differences in intraoperative volume repletion, central venous pressure (CVP), use of vasoactive inotropic agents, and the metabolic outcome. Five-year pancreas graft survival was significantly higher in the >91 mmHg group (>91 mmHg: 82% versus 91 mmHg at the time point of reperfusion was associated with a reduced rate of postoperative complications, enhancing and recovering long-term graft function and outcome and thus increasing long-term survival in SPKT recipients
Immunologic cellular characteristics of the tumour microenvironment of hepatocellular carcinoma drive patient outcomes
Background: Anti-tumour immune competence has an impact in hepatocarcinogenesis and success of anti-cancer
therapies. Tumour-infiltrating lymphocytes (TILs) and monocytes/macrophages (TAMs) are proposed to have significance
in cancer. However, there is only limited data concerning their impact on patient outcome and survival in hepatocellular
carcinoma (HCC).
Methods: Frequencies of CD68+, CD163+M2-polarized TAMs and TILs were measured in de novo HCC tumours in noncirrhosis
(n = 58) using immunohistology and correlated to patients’ clinicopathological characteristics and survival rates.
Results: Patients with tumours marked by appearance of TILs and CD68+ TAMs showed an improved 1-, 3- and 5-year
recurrence-free survival (all p ≤ 0.05). CD68+ TAMs were associated with reduced incidence of recurrent and multifocal
disease. Conversely, CD163+ TAMs were associated with multifocal HCC and lymphangiosis carcinomatosa (all p ≤ 0.05).
Conclusions: TILs and CD68+ TAMs are associated with multiple tumour characteristics and patient survival in HCC.
However, there is only scarce data about the biology underlying their mechanistic involvement in human tumour
progression. Thus, experimental data on functional links might help develop novel immunologic checkpoint inhibitor
targets for liver cancer
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