PCB concentrations in riparian spiders (Tetragnathidae) consistently reflect concentrations in water and aquatic macroinvertebrates, but not sediment: Analysis of a seven-year field study.

Tetragnathid spiders have been used as sentinels to study the biotransport of contaminants between aquatic and terrestrial environments because a significant proportion of their diet consists of adult aquatic insects. A key knowledge gap in assessing tetragnathid spiders as sentinels is understanding the consistency of the year-to-year relationship between contaminant concentrations in spiders and sediment, water, and macroinvertebrates. We collected five years of data over a seven-year investigation at a PCB contaminated-sediment site to investigate if concentrations in spiders were consistently correlated with concentrations in sediment, water, and aquatic macroinvertebrates.

Ecotoxicological Studies Indicate That Sublethal and Lethal Processes Limit Insect-Mediated Contaminant Flux.

Merolimnic insects can accumulate and transport considerable amounts of aquatic contaminants to terrestrial systems. The rate of contaminant biotransport, termed insect-mediated contaminant flux (IMCF), depends on emergent insect biomass and contaminant accumulation, both functions of environmental concentration. We developed a mathematical model of IMCF and apply it to three ecotoxicological studies obtained through the US Environmental Protection Agency's ECOTOX database to determine at which concentration maximum IMCF occurs.

Defining community revitalization in Great Lakes Areas of Concern and investigating how revitalization can be catalyzed through remediation and restoration.

An international effort to restore contaminated areas across the Great Lakes has been underway for over 50 years. Although experts have increasingly recognized the inherent connections between ecological conditions and community level benefits, Great Lakes community revitalization continues to be a broad and complex topic, lacking a comprehensive definition. The purpose of this study was to generate a testable "AOC-Revitalization Framework" for linking remediation and restoration success, represented by Beneficial Use Impairment (BUI) removal in U.

Riparian Spiders: Sentinels of Polychlorinated Dibenzo-p-dioxin and Dibenzofuran-Contaminated Sediment.

Polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD/F) are persistent, toxic, and bioaccumulative. Currently, PCDD/F monitoring programs primarily use fish and birds with potentially large home ranges to monitor temporal trends over broad spatial scales; sentinel organisms that provide targeted sediment contaminant information across small geographic areas have yet to be developed. Riparian orb-weaving spiders, which typically have small home ranges and consume primarily adult aquatic insects, are potential PCDD/F sentinels.

Use of Riparian Spiders as Sentinels of Persistent and Bioavailable Chemical Contaminants in Aquatic Ecosystems: A Review.

Aquatic ecosystems around the world are contaminated with a wide range of anthropogenic chemicals, including metals and organic pollutants, that originate from point and nonpoint sources. Many of these chemical contaminants have complex environmental cycles, are persistent and bioavailable, can be incorporated into aquatic food webs, and pose a threat to the health of wildlife and humans. Identifying appropriate sentinels that reflect bioavailability is critical to assessing and managing aquatic ecosystems impacted by contaminants.

The Spider Exposure Pathway and the Potential Risk to Arachnivorous Birds.

There is growing concern over the health of North American birds, with evidence suggesting substantial population declines. Spiders are prominent dietary items for many bird species and mediate the transfer of contaminants to arachnivorous birds that consume them. Few studies have investigated the potential risk the spider exposure pathway poses to these birds because most studies have focused on piscivores.

Mercury Accumulation in Millipedes (Narceus spp.) Living Adjacent to a Southern Appalachian Mountain Stream (USA).

Millipedes are among the most important processors of leaf litter in temperate forests. Through consumption of leaf litter, millipedes may be exposed to mercury that accumulates in leaf tissues prior to senescence. To investigate mercury uptake in millipedes, Narceus spp.

The Role of Sexual Dimorphism and Tissue Selection in Ecotoxicological Studies Using the Riparian Spider Tetragnatha elongata.

Tetragnathid spiders (Tetragnatha spp.) found in riparian habitats have recently been used as bioindicators of sediment contamination and insect-mediated contaminant flux. We investigated whether sexual dimorphism (size and behavior) influenced the female:male ratio in composite samples, stable isotope ratios (carbon [δC], nitrogen [δN]), and Hg concentrations in the southern United States.

Identifying contaminants of potential concern in remote headwater streams of Tennessee's Appalachian Mountains.

The susceptibility of Tennessee's Appalachian Mountains to anthropogenic stressors has remained largely uninvestigated likely due to a lack of known point source contamination. However, a growing body of scientific evidence suggests that depositional inputs can lead to concerning levels of contamination, even in remote areas. To investigate potential concerns, water quality parameters, contaminants in water (nitrogen, TSS, and metals), and contaminants in eastern brook trout (mercury, polychlorinated biphenyls [PCBs], organochlorine [OC] pesticides, dioxins, furans, and phthalates) were measured in four Appalachian Mountain streams from 2015 to 2017.

Patient-controlled epidural analgesia with fentanyl-bupivacaine: influence of prior dural puncture.

Background And Objectives: Combined spinal epidural anesthesia (CSEA) involves the epidural administration of local anesthetic and opioid solutions adjacent to the prior dural puncture, potentially increasing their diffusion into the subarachnoid space. This study was designed to evaluate the influence of dural puncture on the adequacy and extent of analgesia, and drugs requirements of patient-controlled epidural analgesia (PCEA) in the postoperative period.

Methods: In this prospective double-blind study, 40 patients undergoing major abdominal surgery under general anesthesia followed with PCEA were randomly assigned to either group I (preoperative insertion of an epidural catheter) or group II (preoperative dural puncture with a 25-g Quincke needle + insertion of an epidural catheter).

The distinct gene expression of the pro-hormone convertases in the rat heart suggests potential substrates.

The present study examined the distribution of the pro-hormone convertases PC1, PC2, furin, PACE4 and PC5 in the rat heart. Northern blot analysis of RNA extracted from cardiac tissues showed high levels of furin and PACE4 mRNA in the atria and ventricles, while PC5 mRNA was found to be expressed at high levels in the dorsal aorta. Although undetectable by Northern blot analysis, both PC1 and PC2 mRNA were detected by in situ hybridization and immunohistochemistry in discrete regions of the intracardiac para-aortic ganglia.

Gene structure and chromosomal localization of plasma kallikrein.

Plasma kallikrein (Fletcher factor) is a hepatic serine proteinase that participated in the early phase of blood coagulation. From two genomic libraries, we succeeded to isolate four overlapping clones representing the entire rat plasma kallikrein gene. Using selective DNA sequencing, polymerase chain reactions, and restriction mapping, we demonstrated that the gene for rat plasma kallikrein was 22 kb in length.

Cloning and primary sequence of a mouse candidate prohormone convertase PC1 homologous to PC2, Furin, and Kex2: distinct chromosomal localization and messenger RNA distribution in brain and pituitary compared to PC2.

Using a 796-basepair cDNA fragment obtained from a mouse pituitary library we have screened two mouse insulinoma libraries and isolated a full-length cDNA clone (2516 basepairs; 753 amino acids), designated mPC1. The cDNA sequence of mPC1 codes for a protein containing 753 amino acids and three potential N-glycosylation sites. This cDNA encodes a putative novel subtilisin-like proteinase, exhibiting within its presumed catalytic domain 64%, 55%, and 47% amino acid sequence identity to the recently characterized candidate prohormone convertases human Furin, mouse PC2, and yeast Kex2 gene products, respectively.

Mouse plasma kallikrein: cDNA structure, enzyme characterization, and comparison of protein and mRNA levels among species.

There is differential regulation of liver mRNA levels of rat (r) and mouse (m) plasma kallikrein (PK), as observed on Northern blots. Affinity purification of mPK and rPK, microsequencing, and radioimmunoassay in either rat or mouse showed that the difference in mRNA levels does not appreciably affect the circulating PK concentration. Nuclear run-off assays demonstrated that the regulation of the mRNA level of PK is post-transcriptionally controlled.