Abdominal angina due to recurrence of cancer of the papilla of Vater: a case report

Abdominal angina is usually caused by atherosclerotic disease, and other causes are considered uncommon. This is the first report of a case of abdominal angina secondary to neoplastic vascular stenosis caused by local recurrence of an adenocarcinoma of the papilla of Vater. CASE PRESENTATION: An 80-year-old woman of Caucasian origin presented with abdominal pain and diarrhea. She had undergone a pancreaticoduodenectomy for adenocarcinoma of the papilla of Vater four years earlier. Computed tomography revealed a mass surrounding her celiac trunk and superior mesenteric artery. Her abdominal pain responded poorly to analgesic drugs, but disappeared when oral feedings were withheld. A duplex ultrasonography of the patient's splanchnic vessels was consistent with vascular stenosis. Parenteral nutrition was started and the patient remained pain free until her death. CONCLUSION: Pain relief is an important therapeutic target in patients with cancer. In this case, abdominal pain was successfully managed only after the ischemic cause had been identified. The conventional analgesic therapy algorithm based on nonsteroidal anti-inflammatory drugs and opioids had been costly and pointless, whereas the simple withdrawal of oral feeding spared the patient of the discomfort of additional invasive procedures and allowed her to spend her remaining days in a completely pain-free state

Fires can benefit plants by disrupting antagonistic interactions

Fire has a key role in the ecology and evolution of many ecosystems, yet its effects on plant–insect interactions are poorly understood. Because interacting species are likely to respond to fire differently, disruptions of the interactions are expected. We hypothesized that plants that regenerate after fire can benefit through the disruption of their antagonistic interactions. We expected stronger effects on interactions with specialist predators than with generalists. We studied two interactions between two Mediterranean plants (Ulex parviflorus, Asphodelus ramosus) and their specialist seed predators after large wildfires. In A. ramosus we also studied the generalist herbivores. We sampled the interactions in burned and adjacent unburned areas during 2 years by estimating seed predation, number of herbivores and fruit set. To assess the effect of the distance to unburned vegetation we sampled plots at two distance classes from the fire perimeter. Even 3 years after the fires, Ulex plants experienced lower seed damage by specialists in burned sites. The presence of herbivores on Asphodelus decreased in burned locations, and the variability in their presence was significantly related to fruit set. Generalist herbivores were unaffected. We show that plants can benefit from fire through the disruption of their antagonistic interactions with specialist seed predators for at least a few years. In environments with a long fire history, this effect might be one additional mechanism underlying the success of fire-adapted plants

Optimization in computational systems biology

Optimization aims to make a system or design as effective or functional as possible. Mathematical optimization methods are widely used in engineering, economics and science. This commentary is focused on applications of mathematical optimization in computational systems biology. Examples are given where optimization methods are used for topics ranging from model building and optimal experimental design to metabolic engineering and synthetic biology. Finally, several perspectives for future research are outlined

Charge Transport in DNA-Based Devices

Charge migration along DNA molecules has attracted scientific interest for over half a century. Reports on possible high rates of charge transfer between donor and acceptor through the DNA, obtained in the last decade from solution chemistry experiments on large numbers of molecules, triggered a series of direct electrical transport measurements through DNA single molecules, bundles and networks. These measurements are reviewed and presented here. From these experiments we conclude that electrical transport is feasible in short DNA molecules, in bundles and networks, but blocked in long single molecules that are attached to surfaces. The experimental background is complemented by an account of the theoretical/computational schemes that are applied to study the electronic and transport properties of DNA-based nanowires. Examples of selected applications are given, to show the capabilities and limits of current theoretical approaches to accurately describe the wires, interpret the transport measurements, and predict suitable strategies to enhance the conductivity of DNA nanostructures.Comment: A single pdf file of 52 pages, containing the text and 23 figures. Review about direct measurements of DNA conductivity and related theoretical studies. For higher-resolution figures contact the authors or retrieve the original publications cited in the caption