Infaunal hydraulics generate porewater pressure signals

Many activities by infauna, including burrowing and feeding, involve hydraulic mechanisms. We expected these activities to generate low-frequency pressure waves that would propagate through sediments and be detectable at some distance from the source. Pressure sensors in intertidal sediments recorded large-amplitude porewater pressure signals. Laboratory recordings of single individuals allowed us to identify characteristic signals of arenicolid and nereidid polychaetes and tellinid bivalves. In the bivalve Macoma nasuta, these high-amplitude signals were associated with burrowing, expulsion of pseudofeces, and siphon relocation. In the polychaetes Neanthes brandti and Abarenicola pacifica, the high-amplitude pressure signals were associated with burrowing, burrow construction, burrow ventilation, and defecation. These signals were detectable in the field at distances of at least 20 cm. Since the waveforms are species-specific as well as activity-specific, they may provide a mechanism for prey detection, for predator avoidance, for competitor detection, and perhaps even for mate detection.     

The new vertebrate CYP1C family: cloning of new subfamily members and phylogenetic analysis

Two novel CYP1 genes from teleost fish constituting a new subfamily have been cloned. These paralogous sequences are designated CYP1C1 and CYP1C2. Both genes were initially obtained from untreated scup Stenotomus chrysops tissues by RT-PCR and RACE. Scup CYP1C1 and CYP1C2 code for 524 and 525 amino acids, respectively, and share 80-81% identity at the nucleotide and amino acid levels. Orthologues of CYP1C1 and CYP1C2 were identified in genome databases for other fish species, and both CYP1B1 and CYP1C1 were cloned from zebrafish (Danio rerio). Phylogenetic analysis shows that CYP1Cs and CYP1Bs constitute a sister clade to the CYP1As. Analysis of sequence domains likely to have functional significance suggests that the two CYP1Cs in scup may have catalytic functions and/or substrate specificity that differ from each other and from those of mammalian CYP1Bs or CYP1As. RT-PCR results indicate that CYP1C1 and CYP1C2 are variously expressed in several scup organs.     

Use of saltwater and freshwater habitats by wintering redheads in southern Texas

Behavioral data were gathered for redheads (Aythya americana Eyton) using saltwater and freshwater habitats in southern Texas, the northern portion of their major wintering range, in 1989–90. Saltwater and freshwater habitats were used for different purposes by wintering redheads. Approximately 41% of all redheads in saltwater habitats were feeding, while only 0.1% of redheads in freshwater habitats were feeding. Redheads in saltwater habitats drank infrequently (0.3%), but 7.5% of redheads in freshwater wetlands were drinking. Only 23 courting activities were observed, but all occurred in freshwater wetlands. This study showed that redheads depend on saltwater habitats for feeding, which confirmed similar results from recent studies of redheads in the central and southern portions of the Laguna Madre in southern Texas. This study also showed that redheads depend on freshwater wetlands as sources of drinking water. This concurred with data on redhead behavior in the central portion of the Laguna Madre in Texas, but not for redheads wintering in the southern part of the Laguna Madre. Both habitats, saltwater and freshwater, must be considered as integral components of the redhead winter range throughout southern Texas.     

The modification of the cytotoxic effect of leucocidin by N-ethylmaleimide, flavine mononucleotide and menadione

1. The movement of the cytoplasmic granules in the leucocidin-treated leucocyte is prevented in the presence of N-ethylmaleimide or menadione. This effect follows a change of state in the cytoplasm. It may not be due to reaction with SH groups. When granule movement is prevented in this way the subsequent addition of Ca(2+) and ATP does not induce the secretion of the proteins of the granules. 2. Menadione or iodoacetate stimulates some effects of suboptimum amounts of leucocidin. This effect probably follows a reaction with SH groups. 3. Flavine mononucleotide inhibits some effects of suboptimum amounts of leucocidin. 4. Leucocidin decreases the stimulation of glucose oxidation due to menadione but increases that due to flavine mononucleotide. Leucocidin decreases the adsorption of menadione by leucocytes but increases that of flavine mononucleotide. 5. The redox state of the nicotinamide-adenine nucleotide coenzymes is not altered during leucocidin action and flavine mononucleotide and menadione do not undergo significant continuous oxidation and reduction when added to the leucocyte.     

The interaction of lymphocyte membrane proteins with the lymphocyte cytoskeletal matrix

Lymphocyte membrane proteins are important in the transduction of signals across the plasma membrane. Visual and biophysical studies have shown that after ligand binding, membrane proteins may become immobile in the plane of the membrane and may cap. In intact cells, binding of cross-linking ligands to surface immunoglobulin converts it to a detergent-insoluble state (77% insoluble). This conversion is positively correlated with the transmission of a mitogenic signal. Class II histocompatibility proteins (Ia) and thy-1 remain predominantly detergent soluble (60 to 97% soluble). Insolubilized membrane proteins may be solubilized by incubating the detergent insoluble cytoskeletons with 0.34 M sucrose, 0.5 mM ATP, 0.5 mM dithiothreitol, 1 mM EDTA, or 3 X 10(-5) M DNAase I, 1 mM EDTA. To determine if the membrane-associated cytoskeleton contains the sufficient components for ligand-induced receptor insolubilization, experiments were done with a crude plasma membrane fraction. The results with whole cells or crude plasma membranes were comparable. These studies support the view that ligand-induced insolubilization of membrane proteins is due to their interaction with cytoskeletal structures.     

Inhibition of the p-nitrophenyl phosphatase of leukocyte membranes by p-nitrophenyl phosphate preparation.

The p-nitrophenyl phosphatase activity of leukocyte membranes is dependent on the origin of the p-nitrophenyl phosphate used as substrate. Commercial samples contain stable inhibitors and recrystalized material contains an inhibitor that is decomposed by water. The (Mg²⁺-K⁺)-p-nitrophenyl phosphatase of nerve membranes is not dependent on the origin of the substrate.     

Proteomic analysis of human osteoarthritis synovial fluid

Background

Osteoarthritis is a chronic musculoskeletal disorder characterized mainly by progressive degradation of the hyaline cartilage. Patients with osteoarthritis often postpone seeking medical help, which results in the diagnosis being made at an advanced stage of cartilage destruction. Sustained efforts are needed to identify specific markers that might help in early diagnosis, monitoring disease progression and in improving therapeutic outcomes. We employed a multipronged proteomic approach, which included multiple fractionation strategies followed by high resolution mass spectrometry analysis to explore the proteome of synovial fluid obtained from osteoarthritis patients. In addition to the total proteome, we also enriched glycoproteins from synovial fluid using lectin affinity chromatography.

Results

We identified 677 proteins from synovial fluid of patients with osteoarthritis of which 545 proteins have not been previously reported. These novel proteins included ADAM-like decysin 1 (ADAMDEC1), alanyl (membrane) aminopeptidase (ANPEP), CD84, fibulin 1 (FBLN1), matrix remodelling associated 5 (MXRA5), secreted phosphoprotein 2 (SPP2) and spondin 2 (SPON2). We identified 300 proteins using lectin affinity chromatography, including the glycoproteins afamin (AFM), attractin (ATRN), fibrillin 1 (FBN1), transferrin (TF), tissue inhibitor of metalloproteinase 1 (TIMP1) and vasorin (VSN). Gene ontology analysis confirmed that a majority of the identified proteins were extracellular and are mostly involved in cell communication and signaling. We also confirmed the expression of ANPEP, dickkopf WNT signaling pathway inhibitor 3 (DKK3) and osteoglycin (OGN) by multiple reaction monitoring (MRM) analysis of osteoarthritis synovial fluid samples.

Conclusions

We present an in-depth analysis of the synovial fluid proteome from patients with osteoarthritis. We believe that the catalog of proteins generated in this study will further enhance our knowledge regarding the pathophysiology of osteoarthritis and should assist in identifying better biomarkers for early diagnosis.     

Polychaete chaetae: Function, fossils, and phylogeny

In this article we review the phylogenetic distribution of majorchaetal types within the Polychaeta, discuss what has been demonstratedabout chaetal function in modern worms, and examine what isknown about the evolution of chaete through the fossil record.We conclude with specific cautions about how chaetae are treatedin phylogenetic analyses and make suggestions about how theycould be used to provide a stronger phylogenetic signal.