Using bivalve chronologies for quantifying environmental drivers in a semi-enclosed temperate sea.

Annual growth increments formed in bivalve shells are increasingly used as proxies of environmental variability and change in marine ecosystems, especially at higher latitudes. Here, we document that well-replicated and exactly dated chronologies can also be developed to capture oceanographic processes in temperate and semi-enclosed seas, such as the Mediterranean. A chronology is constructed for Glycymeris pilosa from a shallow embayment of the northern Adriatic and extends from 1979 to 2016. The chronology significantly (p < 0.05) and positively correlates to winter sea surface temperatures, but negatively correlates to summer temperatures, which suggests that extreme winter lows and extreme summer highs may be limiting to growth. However, the strongest and most consistent relationships are negative correlations with an index of the Adriatic-Ionian Bimodal Oscillating System (BiOS) for which positive values indicate the inflow of the ultraoligotrophic Eastern Mediterranean waters to the Adriatic. In contrast, the substantial freshwater flows that discharge into the Adriatic do not correlate to the bivalve chronology, emphasizing the importance of remote oceanographic processes to growth at this highly coastal site. Overall, this study underscores the potential of bivalve chronologies to capture biologically relevant, local- to regional-scale patterns of ocean circulation in mid-latitude, temperate systems.

Climate change. Climate change and wind intensification in coastal upwelling ecosystems.

In 1990, Andrew Bakun proposed that increasing greenhouse gas concentrations would force intensification of upwelling-favorable winds in eastern boundary current systems that contribute substantial services to society. Because there is considerable disagreement about whether contemporary wind trends support Bakun's hypothesis, we performed a meta-analysis of the literature on upwelling-favorable wind intensification. The preponderance of published analyses suggests that winds have intensified in the California, Benguela, and Humboldt upwelling systems and weakened in the Iberian system over time scales ranging up to 60 years; wind change is equivocal in the Canary system. Stronger intensification signals are observed at higher latitudes, consistent with the warming pattern associated with climate change. Overall, reported changes in coastal winds, although subtle and spatially variable, support Bakun's hypothesis of upwelling intensification in eastern boundary current systems.

Vaccination with tumor cells expressing IL-15 and IL-15Rα inhibits murine breast and prostate cancer.

A number of antitumor vaccines have recently shown promise in upregulating immune responses against tumor antigens and improving patient survival. In this study, we examine the effectiveness of vaccination using interleukin (IL)-15-expressing tumor cells and also examine their ability to upregulate immune responses to tumor antigens. We demonstrated that the coexpression of IL-15 with its receptor, IL-15Rα, increased the cell-surface expression and secretion of IL-15. We show that a gene transfer approach using recombinant adenovirus to express IL-15 and IL-15Rα in murine TRAMP-C2 prostate or TS/A breast tumors induced antitumor immune responses. From this, we developed a vaccine platform, consisting of TRAMP-C2 prostate cancer cells or TS/A breast cancer cells coexpressing IL-15 and IL-15Rα that inhibited tumor formation when mice were challenged with tumor. Inhibition of tumor growth led to improved survival when compared with animals receiving cells expressing IL-15 alone or unmodified tumor cells. Animals vaccinated with tumor cells coexpressing IL-15 and IL-15Rα showed greater tumor infiltration with CD8(+) T and natural killer (NK) cells, as well as increased antitumor CD8(+) T-cell responses. Vaccination with IL-15/IL-15Rα-modified TS/A breast cancer cells provided a survival advantage to mice challenged with unrelated murine TUBO breast cancer cells, indicating the potential for allogeneic IL-15/IL-15Rα-expressing vaccines.

Transplantation of fetal cholinergic neurons into the hippocampus attenuates the cognitive and neurochemical deficits induced by AF64A.

The present experiments examined whether transplanted fetal cholinergic neurons would attenuate the behavioral and neurochemical deficits induced by the cholinotoxin AF64A (ethylcholine aziridinium ion). Bilateral injections of AF64A (3 nmol) into the lateral ventricles produced significant learning and memory impairments together with decreases in hippocampal high-affinity choline uptake (HAChU). AF64A-treated rats were impaired on both a standard radial arm maze (RAM) task and a working memory version in which a one-hour delay was imposed between the fourth and fifth arm choices. Transplantation of embryonic day E-17 septal/diagonal band tissue into the hippocampus (HPC) promoted recovery of performance on the standard version of the RAM task. However, this recovery was not observed when the animals were tested on the more difficult delay version of the task. Neurochemical analysis indicated that AF64A produced a significant (31%) decrease in hippocampal HAChU that was attenuated (14%) by transplantation of fetal cholinergic neurons. Histological analysis revealed that the transplants survived and innervated the HPC. There was no apparent relationship between fiber ingrowth into the HPC and behavioral recovery. These data indicate that transplant-induced behavioral recovery may be related to and limited by the cognitive demands of the testing situation. Generalized increases in cholinergic activity, transplant-mediated release of trophic factors, or a combination of both may underlie the behavioral recovery observed in the present studies.

Effects of acid on the basal lamina of the rat stomach and duodenum.

Rapid restitution of the gastric and intestinal epithelium after acute injury involves emigration of cells from the gastric glands and basal half of the intestinal villi. An intact basal lamina is prerequisite to the restitution process. The present study was performed to determine the effects of acid on the rat gastric and duodenal basal lamina. The basal lamina was denuded in vitro by ultrasonic vibration. The tissue was then immersed in 0.2 M mannitol (control) or in HCl (5-50 mM) for 10 min. Samples of the tissues were examined by transmission and scanning electron microscopy. Some samples were stained with ruthenium red to demonstrate glycosaminoglycans. The lower concentrations of acid (5 and 10 mM) had little or no effect on the structure of the basal lamina. However, exposure to 20 and 50 mM HCl caused extensive damage to the basal lamina and exposed the underlying connective tissue matrix of the lamina propria. Ruthenium red staining demonstrated differences in size and location of glycosaminoglycans within the basal laminae of stomach and intestine. Exposure to acid at concentrations of 20 or 50 mM caused total loss of ruthenium red staining in both intestinal and gastric basal laminae. Exposure to 10 mM acid resulted in loss of the outermost (luminal) layer of anionic sites from the gastric basal lamina. These studies demonstrate that brief exposure to acid, in concentrations which are necessary for the formation of hemorrhagic erosions in the stomach, caused damage to the basal lamina. This damage may impair epithelial restitution and thus account, in part, for the role of acid in ulcerogenesis.