Fibrinogen–Fibrin System Regulators from Bloodsuckers

Thrombin inhibitors from bloodsucking leeches and insects that block conversion of fibrinogen to fibrin are considered. Regulatory mechanisms influencing the fibrinogen–fibrin system in leeches include fibrinogen degradation, inhibition of factor XIIIa, and lysis of fibrin clots. The review also summarizes recent data on plasminogen activator from the vampire bat Desmodus rotundus and a role of fibrin as its cofactor.     

Selenium–Mercury Interactions in Man and Animals

Selenium–mercury interactions were most extensively studied in relation to alleviation of Hg toxicity by added selenium. This presentation considers the influence of mercury on endogenous selenium, on its tissue and cellular “status” after lifelong or acute exposure to mercury vapor (Hg^o). Discussed are data obtained from (1) humans living near or working in a mercury mine, and (2) rats experimentally exposed in the mine. Mercury vapor is unique—or similar to methylmercury—because of its ability to penetrate cell membranes and so invade all cells, where it is oxidized in the biologically active form (Hg⁺⁺) by catalase. Such in situ-generated ions can react with endogenously generated highly reactive Se metabolites, like HSe−, and render a part of the selenium unavailable for selenoprotein synthesis. Data on human populations indicate that in moderate Hg exposure combined with an adequate selenium supply through diet, Se bioavailability can be preserved. On the other hand, the results of an acute exposure study emphasize the dual role of selenium in mercury detoxification. Besides the well-known Se coaccumulation through formation of nontoxic Hg–Se complexes, we observed noticeable Se (co)excretion, at least at the beginning of exposure. The higher Hg accumulation rate in the group of animals with lower basal selenium levels can also point to selenium involvement in mercury excretion. In such conditions there is a higher probability for decreased selenoprotein levels (synthesis) in some tissues or organs, depending on the synthesis hierarchy.     

Nitric Oxide and TNFα Are Critical Regulators of Reversible Lymph Node Vascular Remodeling and Adaptive Immune Response

Lymph node (LN) vascular growth, at the level of the main arteriole, was recently characterized for the first time during infection. Arteriole diameter was shown to increase for at least seven days and to occur via a CD4⁺ T cell dependent mechanism, with vascular expansion playing a critical role in regulating induction of adaptive immune response. Here, using intravital microscopy of the inguinal LN during herpes simplex type II (HSV-2) infection, the data provides the first studies that demonstrate arteriole expansion during infection is a reversible vascular event that occurs via eutrophic outward remodeling. Furthermore, using genetic ablation models, and pharmacological blockade, we reveal arteriole remodeling and LN hypertrophy to be dependent upon both endothelial nitric oxide synthase (eNOS) and TNFα expression. Additionally, we reveal transient changes in nitric oxide (NO) levels to be a notable feature of response to viral infection and LN vascular remodeling and provide evidence that mast cells are the critical source of TNFα required to drive arteriole remodeling. Overall, this study is the first to fully characterize LN arteriole vascular changes throughout the course of infection. It effectively reveals a novel role for NO and TNFα in LN cellularity and changes in LN vascularity, which represent key advances in understanding LN vascular physiology and adaptive immune response.     

Group VIB Calcium-Independent Phospholipase A2 (iPLA2γ) Regulates Platelet Activation,Hemostasis and Thrombosis in Mice

In platelets, group IVA cytosolic phospholipase A₂ (cPLA₂α) has been implicated as a key regulator in the hydrolysis of platelet membrane phospholipids, leading to pro-thrombotic thromboxane A₂ and anti-thrombotic 12-(S)-hydroxyeicosatetranoic acid production. However, studies using cPLA₂α-deficient mice have indicated that other PLA₂(s) may also be involved in the hydrolysis of platelet glycerophospholipids. In this study, we found that group VIB Ca²⁺-independent PLA₂ (iPLA₂γ)-deficient platelets showed decreases in adenosine diphosphate (ADP)-dependent aggregation and ADP- or collagen-dependent thromboxane A₂ production. Electrospray ionization mass spectrometry analysis of platelet phospholipids revealed that fatty acyl compositions of ethanolamine plasmalogen and phosphatidylglycerol were altered in platelets from iPLA₂γ-null mice. Furthermore, mice lacking iPLA₂γ displayed prolonged bleeding times and were protected against pulmonary thromboembolism. These results suggest that iPLA₂γ is an additional, long-sought-after PLA₂ that hydrolyzes platelet membranes and facilitates platelet aggregation in response to ADP.     

Beam–Plasma Discharge in Space and in a Lab

Plasma Physics Reports - The process and applications of a specific type of gaseous discharge—beam–plasma discharge (BPD)—are reviewed. A brief survey of the BPD theory is...     

Dissociation of Increases in PGC-1α and Its Regulators from Exercise Intensity and Muscle Activation Following Acute Exercise

Muscle activation as well as changes in peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) following high-intensity interval exercise (HIIE) were examined in young healthy men (n  = 8; age, 21.9±2.2 yrs; VO₂peak, 53.1±6.4 ml/min/kg; peak work rate, 317±23.5 watts). On each of 3 visits HIIE was performed on a cycle ergometer at a target intensity of 73, 100, or 133% of peak work rate. Muscle biopsies were taken at rest and three hours after each exercise condition. Total work was not different between conditions (∼730 kJ) while average power output (73%, 237±21; 100%, 323±26; 133%, 384±35 watts) and EMG derived muscle activation (73%, 1262±605; 100%, 2089±737; 133%, 3029±1206 total integrated EMG per interval) increased in an intensity dependent fashion. PGC-1α mRNA was elevated after all three conditions (p<0.05), with a greater increase observed following the 100% condition (∼9 fold, p<0.05) compared to both the 73 and 133% conditions (∼4 fold). When expressed relative to muscle activation, the increase in PGC-1α mRNA for the 133% condition was less than that for the 73 and 100% conditions (p<0.05). SIRT1 mRNA was also elevated after all three conditions (∼1.4 fold, p<0.05), with no difference between conditions. These findings suggest that intensity-dependent increases in PGC-1α mRNA following submaximal exercise are largely due to increases in muscle recruitment. As well, the blunted response of PGC-1α mRNA expression following supramaximal exercise may indicate that signalling mediated activation of PGC-1α may also be blunted. We also indentify that increases in PDK4, SIRT1, and RIP140 mRNA following acute exercise are dissociated from exercise intensity and muscle activation, while increases in EGR1 are augmented with supramaximal HIIE (p<0.05).     

Radiative Surface Waves in Layered Plasma–Dielectric Structures and Prospects of Their Application in Plasma Microwave Electronics

Plasma Physics Reports - Surface waves in layered systems consisting of material media with different frequency dispersions are considered: dielectric–plasma–vacuum,...     

Are Baby Animals Less Appetizing? Tenderness toward Baby Animals and Appetite for Meat

Three studies investigated whether thoughts and feelings generated by baby animals might oppose appetite for meat. A prestudy established babyness as an important factor predicting moral concern for farmed animals. Study 1 showed that presenting images of baby animals, versus adult animals, as the source of meat reduced appetite for meat, but this effect was weak and found exclusively among women. Study 2 replicated and extended study 1 using a larger sample and two new animal sources. Study 3 included a no animal comparison condition, and found greatest levels of reduced appetite for meat when the meat source was presented as a baby animal, as opposed to an adult animal or with no visual indication of the animal source. A meta-analysis of the results using Bayes factors revealed considerable cumulative evidence in favor of the hypothesis that images of baby animals temporarily reduce women’s appetite for meat. In contrast, the evidence for men was less strong. Our results highlight a tension within some omnivores between caring for baby animals and appetite for meat.     

Extensive Gene Duplication in the Early Evolution of Animals Before the Parazoan–Eumetazoan Split Demonstrated by G Proteins and Protein Tyrosine Kinases from Sponge and Hydra

To know whether genes involved in cell–cell communication typical of multicellular animals dramatically increased in concert with the Cambrian explosion, the rapid evolutionary burst in the major groups of animals, and whether these genes exist in the sponge lacking cell cohesiveness and coordination typical of eumetazoans, we have carried out cloning of the G-protein α subunit (Gα) and the protein tyrosine kinase (PTK) cDNAs from Ephydatia fluviatilis (freshwater sponge) and Hydra magnipapillata strain 105 (hydra). We obtained 13 Gα and 20 PTK cDNAs. Generally animal gene families diverged first by gene duplication (subtype duplication) that gave rise to diverse subtypes with different primary functions, followed by further gene duplication in the same subtype (isoform duplication) that gave rise to isoform genes with virtually identical function. Phylogenetic trees of Gα and PTK families including cDNAs from sponge and hydra revealed that most of the present-day subtypes had been established in the very early evolution of animals before the parazoan–eumetazoan split, the earliest branching among the extant animal phyla, by extensive subtype duplication: for PTK and Gα families, 23 and 9 subtype duplications were observed in the early stage before the parazoan–eumetazoan split, respectively, and after that split, only 2 and 1 subtype duplications were found, respectively. After the separation from arthropods, vertebrates underwent frequent isoform duplications before the fish–tetrapod split. Furthermore, rapid amino acid changes appear to have occurred in concert with the extensive subtype duplication and isoform duplication. Thus the pattern of gene diversification during animal evolution might be characterized by bursts of gene duplication interrupted by considerably long periods of silence, instead of proceeding gradually, and there might be no direct link between the Cambrian explosion and the extensive gene duplication that generated diverse functions (subtypes) of these families. Received: 4 November 1998 / Accepted: 17 November 1998     

Role of Calcium-independent Phospholipase A2�� in High Glucose-induced Activation of RhoA, Rho Kinase, and CPI-17 in Cultured Vascular Smooth Muscle Cells and Vascular Smooth Muscle Hypercontractility in Diabetic Animals

Previous studies suggest that high glucose-induced RhoA/Rho kinase/CPI-17 activation is involved in diabetes-associated vascular smooth muscle hypercontractility. However, the upstream signaling that links high glucose and RhoA/Rho kinase/CPI-17 activation is unknown. Here we report that calcium-independent phospholipase A₂β (iPLA₂β) is required for high glucose-induced RhoA/Rho kinase/CPI-17 activation and thereby contributes to diabetes-associated vascular smooth muscle hypercontractility. We demonstrate that high glucose increases iPLA₂β mRNA, protein, and iPLA₂ activity in a time-dependent manner. Protein kinase C is involved in high glucose-induced iPLA₂β protein up-regulation. Inhibiting iPLA₂β activity with bromoenol lactone or preventing its expression by genetic deletion abolishes high glucose-induced RhoA/Rho kinase/CPI-17 activation, and restoring expression of iPLA₂β in iPLA₂β-deficient cells also restores high glucose-induced CPI-17 phosphorylation. Pharmacological and genetic inhibition of 12/15-lipoxygenases has effects on high glucose-induced CPI-17 phosphorylation similar to iPLA₂β inhibition. Moreover, increases in iPLA₂ activity and iPLA₂β protein expression are also observed in both type 1 and type 2 diabetic vasculature. Pharmacological and genetic inhibition of iPLA₂β, but not iPLA₂γ, diminishes diabetes-associated vascular smooth muscle hypercontractility. In summary, our results reveal a novel mechanism by which high glucose-induced, protein kinase C-mediated iPLA₂β up-regulation activates the RhoA/Rho kinase/CPI-17 via 12/15-lipoxygenases and thereby contributes to diabetes-associated vascular smooth muscle hypercontractility.     

Dust–Acoustic Envelope Solitons and Rogue Waves in a Magnetized Electron-Depleted Plasma

Plasma Physics Reports - A theoretical investigation is made to study the properties of dust–acoustic (DA) waves, and corresponding dust–acoustic rogue waves (DARWs) in a magnetized...     

Animals in science education—ethics and alternatives

Increasingly, moral objections are being voiced to the use or killing of animals for educational purposes, and students' opinions are reflecting this. An animal rights philosophy often underlies these objections, but many people are unaware of the logic of the animal rights position, which is often dismissed as sentimentalism or anthropomorphism. While it is now possible to take A-level biology without undertaking dissection, there are many potential undergraduate students who would like to do courses in biology, medicine, pharmacology, physiology, and nursing, but are dissuaded by the animal use involved. Such students are frequently not offered non-animal options and risk being marked down in course work and exams, even though considerable advances have been made in the development of alternative teaching aids. This article summarizes the animal rights argument, and reviews some of the alternative approaches and their teaching effectiveness.     

Dust–Ion–Acoustic Solitary Wave Structure in Magnetized Plasma with Nonthermally Distributed Electrons and Positrons

Plasma Physics Reports - The dust–ion–acoustic (DIA) solitary wave (SW) propagation in a magnetized dusty plasma consisting of mobile positive and heavy negative ions, nonthermal...     

“Animals Like Us”: Identifying with Nonhuman Animals and Support for Nonhuman Animal Rights

While anthropomorphizing nonhuman animals has been shown to increase identification with them and, by extension, concern for their wellbeing, little research has directly tested whether identifying with nonhuman animals is similarly associated with concern for their wellbeing. We tested hypotheses related to this premise across three cross-sectional studies. In study 1 (n = 224), we tested the hypothesis that therians—a group of people who self-identify with nonhuman animals, show greater concern for nonhuman animal rights than non-therian furries—people with a fan-like interest in media featuring anthropomorphized animal characters. In study 2 (n = 206), we further tested this hypothesis using implicit and explicit measures of identification with nonhuman animals to predict behavioral intentions to support nonhuman animal rights. In study 3 (n = 182), we tested the generalizability of our findings in a sample of undergraduate students. Taken together, the studies show that explicit, but not implicit, identification with nonhuman animals predicts greater support for their rights. The implications of these findings for research on anthropomorphism and animal rights activism are discussed, as well as the limitations of these findings and possible avenues for future research.     

Pharmacokinetics, Tissue Distribution and Excretion of Recombinant Human Parathyroid Hormone 1–84 in Animals

To study the plasma pharmacokinetics and accumulation of the recombinant human parathyroid hormone (rhPTH) (1–84) in rhesus monkeys, and the tissue distribution and excretion profiles of ¹²⁵I-rhPTH (1–84) in rats. The concentration of rhPTH (1–84) in plasma samples were determined by an enzyme immunoassay (EIA) method after subcutaneous and intravenous bolus injection. The tissue distribution and urinary, fecal and biliary excretion patterns of ¹²⁵I-rhPTH (1–84) were investigated by trichloroacetic acid (TCA) precipitation method. Following subcutaneous (sc) administration rhPTH (1–84) in rhesus monkeys, rhPTH (1–84) exhibited rapid absorption and elimination and had no accumulated tendency after successive sc administration. Following sc administration ¹²⁵I-rhPTH (1–84) in rats, the TCA-precipitated radioactivity was widely distributed and rapidly diminished in most tissues. Approximately 83.9 and 6.8 % of the total radioactivity was recovered in urine and feces by 72 h postdosing, respectively; whereas 4.1 % excreted into bile up to 24 h postdosing. The pharmacokinetics of rhPTH (1–84) complied with linear kinetics within the examined dose range following a single sc administration had no accumulated tendency following multiple sc administration in rhesus monkeys. The accumulation of ¹²⁵I-rhPTH (1–84) in tissues/organs examined, appeared to be low in rats. The major elimination route was by urinary excretion.     

Aspidospermatan–aspidospermatan and eburnane-sarpagine bisindole alkaloids from Leuconotis

Leucofoline and leuconoline, representing the first members of the aspidospermatan–aspidospermatan and eburnane-sarpagine subclasses of the bisindole alkaloids, respectively, were isolated from the Malayan Leuconotis griffithii. The structures of these bisindole alkaloids were established using NMR and MS analysis, and in the case of leuconoline, confirmed by X-ray diffraction analysis. Both alkaloids showed weak cytotoxicity towards human KB cells.