Predictors of malignant transformation in mucinous pancreatic cystic neoplasm: A systemic review and meta-analysis.

BACKGROUND: The presence of ovarian-type stroma defines mucinous cystic neoplasm (MCN). Criteria for surgical resection differ between current consensus guidelines (IAP, AGA, and Europe). This meta-analysis aims to describe pre-surgical clinical parameters that predict malignant transformation of MCN of the pancreas. METHODS: A systematic review and meta-analysis of articles published from 2006 to the time of manuscript authorship in December 2022. The electronic databases included English publications in Ovid MEDLINE In-Process & Other Non-Indexed Citations, Ovid MEDLINE, Ovid EMBASE, and Scopus. RESULTS: 17 studies were identified and included 1058 patients with MCN treated with pancreatectomy. The mean cohort age was 48.2 years (standard deviation [SD] ± 7.9) with an expected female predominance (96 %). The presenting symptom for most was abdominal pain (55.6 %), however, nearly 20 % of patients were asymptomatic. Most patients were treated with distal pancreatectomy (70.5 %), and the mean tumor size was 45 mm. The rate of invasive cancer was 13.8 %. Cysts with mural nodules had a higher risk of developing invasive tumors than those that did not (OR 26.47, 95%CI 12.57-55.74, p < 0.001, I2:0 %). Other clinical factors such as the presence of intramural calcifications or an elevated serum CA 19-9 (>37U/mL) were not predictive of malignancy. CONCLUSION: The present meta-analysis did not clarify establishing reliable predictors for malignant transformation other than mural modularity, which may represent tumors that have already undergone transformation. It may be used as a criterion in treatment decision-making.

A Combination of Biochemical and Pathological Parameters Improves Prediction of Postresection Survival After Preoperative Chemotherapy in Pancreatic Cancer: The PANAMA-score.

OBJECTIVE: To build a prognostic score for patients with primary chemotherapy undergoing surgery for pancreatic cancer based on pathological parameters and preoperative Carbohydrate antigen 19-9 (CA19-9) levels. BACKGROUND: Prognostic stratification after primary chemotherapy for pancreatic cancer is challenging and prediction models, such as the AJCC staging system, lack validation in the setting of preoperative chemotherapy. METHODS: Patients with primary chemotherapy resected at the Massachusetts General Hospital between 2007 and 2017 were analyzed. Tumor characteristics independently associated with overall survival were identified and weighted by Cox-proportional regression. The pancreatic neoadjuvant Massachusetts-score (PANAMA-score) was computed from these variables and its performance assessed by Harrel concordance index and area under the receiving characteristics curves analysis. Comparisons were made with the AJCC staging system and external validation was performed in an independent cohort with primary chemotherapy from Heidelberg, Germany. RESULTS: A total of 216 patients constituted the training cohort. The multivariate analysis demonstrated tumor size, number of positive lymph-nodes, R-status, and high CA19-9 to be independently associated with overall survival. Kaplan-Meier analysis according to low, intermediate, and high PANAMA-score showed good discriminatory power of the new metrics (P < 0.001). The median overall survival for the three risk-groups was 45, 27, and 12 months, respectively. External validation in 258 patients confirmed the prognostic ability of the score and demonstrated better accuracy compared with the AJCC staging system. CONCLUSION: The proposed PANAMA-score, based on independent predictors of postresection survival, including pathologic variables and CA19-9, not only provides better discrimination compared to the AJCC staging system, but also identifies patients at high-risk for early death.

Plant carbohydrate content limits performance and lipid accumulation of an outbreaking herbivore.

Locusts are major intermittent threats to food security and the ecological factors determining where and when these occur remain poorly understood. For many herbivores, obtaining adequate protein from plants is a key challenge. We tested how the dietary protein : non-structural carbohydrate ratio (p : c) affects the developmental and physiological performance of 4th-5th instar nymphs of the South American locust, Schistocerca cancellata, which has recently resurged in Argentina, Bolivia and Paraguay. Field marching locusts preferred to feed on high carbohydrate foods. Field-collected juveniles transferred to the laboratory selected artificial diets or local plants with low p : c. On single artificial diets, survival rate increased as foods became more carbohydrate-biased. On single local plants, growth only occurred on the plant with the lowest p : c. Most local plants had p : c ratios substantially higher than optimal, demonstrating that field marching locusts must search for adequate carbohydrate or their survival and growth will be carbohydrate-limited. Total body lipids increased as dietary p : c decreased on both artificial and plant diets, and the low lipid contents of field-collected nymphs suggest that obtaining adequate carbohydrate may pose a strong limitation on migration for S. cancellata. Anthropogenic influences such as conversions of forests to pastures, may increase carbohydrate availability and promote outbreaks and migration of some locusts.

Effects of temperature on responses to anoxia and oxygen reperfusion in Drosophila melanogaster.

Insects in general, and Drosophila in particular, are much more capable of surviving anoxia than vertebrates, and the mechanisms involved are of considerable biomedical and ecological interest. Temperature is likely to strongly affect both the rates of damage occurring in anoxia and the recovery processes in normoxia, but as yet there is no information on the effect of this crucial variable on recovery rates from anoxia in any animal. We studied the effects of temperature, and thus indirectly of metabolic flux rates, on survival and recovery times of individual male Drosophila melanogaster following anoxia and O(2) reperfusion. Individual flies were reared at 25°C and exposed to an anoxic period of 7.5, 25, 42.5 or 60 min at 20, 25 or 30°C. Before, during and after anoxic exposure the flies' metabolic rates (MRs), rates of water loss and activity indices were recorded. Temperature strongly affected the MR of the flies, with a Q(10) of 2.21. Temperature did not affect the slope of the relationship between time to recovery and duration of anoxic exposure, suggesting that thermal effects on damage and repair rates were similar. However, the intercept of that relationship was significantly lower (i.e. recovery was most rapid) at 25°C, which was the rearing temperature. When temperatures during exposure to anoxia and during recovery were switched, recovery times matched those predicted from a model in which the accumulation and clearance of metabolic end-products share a similar dependence on temperature.

The flight physiology of reproductives of Africanized, European, and hybrid honeybees (Apis mellifera).

Neotropical African honeybees (Apis mellifera scutellata), in the process of spreading throughout tropical and subtropical regions of the Americas, hybridize with and mostly replace European honeybees (primarily Apis mellifera mellifera and Apis mellifera ligustica). To help understand this process, we studied the effect of lineage (African, European, or hybrid) on the flight physiology of honeybee reproductives. Flight metabolic rates were higher in queens and drones of African lineage than in European or hybrid bees, as has been previously found for foraging workers. These differences were associated with higher thorax/body mass ratios and higher thorax-specific metabolic rates in African lineage bees. Queens were reared in common colonies, so these metabolic and morphological differences are likely to be genetic in origin. African drones had higher wing beat frequencies and thorax temperatures than European or hybrid bees. Hybrids were intermediate for many parameters, but hybrid queen mass-specific flight metabolic rates were low relative to Africans and were nonlinearly affected by the proportion of African lineage, consistent with some negative heterosis for this trait.