Structure and sensory physiology of the leg scolopidial organs in Mantophasmatodea and their role in vibrational communication

Individuals of the insect order Mantophasmatodea use species-specific substrate vibration signals for mate recognition and location. In insects, substrate vibration is detected by mechanoreceptors in the legs, the scolopidial organs. In this study we give a first detailed overview of the structure, sensory sensitivity, and function of the leg scolopidial organs in two species of Mantophasmatodea and discuss their significance for vibrational communication. The structure and number of the organs are documented using light microscopy, SEM, and x-ray microtomography. Five scolopidial organs were found in each leg of male and female Mantophasmatodea: a femoral chordotonal organ, subgenual organ, tibial distal organ, tibio-tarsal scolopidial organ, and tarso-pretarsal scolopidial organ. The femoral chordotonal organ, consisting of two separate scoloparia, corresponds anatomically to the organ of a stonefly (Nemoura variegata) while the subgenual organ complex resembles the very sensitive organs of the cockroach Periplatena americana (Blattodea). Extracellular recordings from the leg nerve revealed that the leg scolopidial organs of Mantophasmatodea are very sensitive vibration receptors, especially for low-frequency vibrations. The dominant frequencies of the vibratory communication signals of Mantophasmatodea, acquired from an individual drumming on eight different substrates, fall in the frequency range where the scolopidial organs are most sensitive.

Effects of emissions from different type of residential heating upon cyclic guanosine monophosphate (cGMP) in blood platelets of residents

We hypothesized that different types of residential heating would be associated with different levels of indoor carbon monoxide (CO) and further that this might result in a differential in the concentration of cyclic 3':5' guanosine monophosphate (cGMP) in blood platelets in exposed residents. Individuals, who were recruited from homes using different fuel for heating, donated a venous blood sample in the winter and in the summer. In the winter the median blood platelet cGMP value for the group using liquid propane gas (LPG) was 65% higher than for the group using piped natural gas for heating (p <0.001). Also in the group using LPG, the median concentration of cGMP in the winter was 39% higher than the summer median (p < 0.003). The mean indoor concentrations of CO were measured over a period of 1 week during the winter and were <1 ppm. We conclude that observed differences were associated with emissions from different types of heating but that CO exposure alone is too low to explain these.

Identification of clinically relevant cross-sensitization between Soliadgo virgaurea (goldenrod) and Hevea brasiliensis (natural rubber latex)

BACKGROUND

Solidago virgaurea (goldenrod) is a perennial weed from which no allergens have been identified. A high latex content in its leaves has been reported. Although not an airborne allergen, it may be an important occupational sensitizer.

OBJECTIVE

To identify allergenic proteins in goldenrod and to determine whether they cross-react with Hevea brasiliensis latex.

METHODS

Potential cross-reactive allergens in latex and goldenrod were investigated by immunoblot inhibition and ImmunoCAP inhibition analyses using serum from patients with clinically evident goldenrod and/or latex allergy. Cross reactivity between latex allergens and goldenrod proteins was studied using recombinant Hev b 1, 3, 4, 5, 6.01, 6.02, 8, 9, or 11 in ImmunoCAP inhibition analyses.

RESULTS

Immunoglobulin (Ig) E antibodies from individuals with goldenrod allergy bound extracted goldenrod proteins ranging from 20 kDa to 130 kDa in Western blots. Evidence for latex and goldenrod cross reactivity was identified by ImmunoCAP and immunoblot inhibition experiments using serum from patients with strongly positive concomitant latex and goldenrod-specific IgE antibody responses. Observed latex-goldenrod cross reactivity could not be ascribed to any of the recombinant major latex allergens evaluated.

CONCLUSIONS

H brasiliensis latex and goldenrod contain cross-reactive and unique allergenic proteins. Exposure to goldenrod may sensitize patients to latex and vice versa.

A uniquely high number of ftsZ genes in the moss Physcomitrella patens

Plant FtsZ proteins are encoded by two small nuclear gene families (FtsZ1 and FtsZ2) and are involved in chloroplast division. From the moss Physcomitrella patens, four FtsZ proteins, two in each nuclear gene family, have been characterised and described so far. In the recently sequenced P. patens genome, we have now found a fifth ftsZ gene. This novel gene has a genomic structure similar to PpftsZ1-1. According to phylogenetic analysis, the encoded protein is a member of the FtsZ1 family, while PpFtsZ1-2, together with an orthologue from Selaginella moellendorffii, forms a separate clade. Further, this new gene is expressed in different gametophytic tissues and the encoded protein forms filamentous networks in chloroplasts, is found in stromules, and acts in plastid division. Based on all these results, we have renamed the PpFtsZ proteins of family 1 and suggest the existence of a third FtsZ family. No species is known to encode more FtsZ proteins per haploid genome than P. patens.

Grading quality of evidence and strength of recommendations in clinical practice guidelines. Part 1 of 3. An overview of the GRADE approach and grading quality of evidence about interventions

The GRADE (Grades of Recommendation, Assessment, Development, and Evaluation) approach provides guidance to grading the quality of underlying evidence and the strength of recommendations in health care. The GRADE system's conceptual underpinnings allow for a detailed stepwise process that defines what role the quality of the available evidence plays in the development of health care recommendations. The merit of GRADE is not that it eliminates judgments or disagreements about evidence and recommendations, but rather that it makes them transparent. This first article in a three-part series describes the GRADE framework in relation to grading the quality of evidence about interventions based on examples from the field of allergy and asthma. In the GRADE system, the quality of evidence reflects the extent to which a guideline panel's confidence in an estimate of the effect is adequate to support a particular recommendation. The system classifies quality of evidence as high, moderate, low, or very low according to factors that include the study methodology, consistency and precision of the results, and directness of the evidence.

Metabolism and excretion of rivaroxaban, an oral, direct factor Xa inhibitor, in rats, dogs, and humans

Rivaroxaban is a novel, oral, direct factor Xa inhibitor for the prevention and treatment of thromboembolic disorders. The objective of this study was to investigate the in vivo metabolism and excretion of rivaroxaban in rats, dogs, and humans. Single doses of [(14)C]rivaroxaban (3 and 1 mg/kg) were administered to rats (orally/intravenously) and dogs (orally), respectively. A single oral dose of [(14)C]rivaroxaban (10 mg) was administered to healthy human males (n = 4). Plasma and excreta were collected and profiled for radioactivity. Recovery of total radioactivity was high and > or = 92% in all species. Unchanged rivaroxaban was the major compound in plasma at all time points investigated, across all species. No major or pharmacologically active circulating metabolites were detected. Rivaroxaban and its metabolites were rapidly excreted; urinary excretion of radioactivity was 25 and 52%, and fecal excretion was 67 and 43% of the dose in rats and dogs, respectively. In humans, 66% of the dose was excreted renally (36% unchanged drug) and 28% in the feces. Radioactivity profiles in excreta were similar across species. Three metabolic pathways were identified: oxidative degradation of the morpholinone moiety (major pathway) and hydrolysis of the central amide bond and of the lactam amide bond in the morpholinone ring (minor pathways). M-1, the main metabolite in excreta of all species, was eliminated via both renal and fecal/biliary routes. In total, 82 to 89% of the dose administered was assigned to unchanged rivaroxaban and its metabolites in the excreta of rats, dogs, and humans.

In vitro metabolism of rivaroxaban, an oral, direct factor Xa inhibitor, in liver microsomes and hepatocytes of rats, dogs, and humans

The in vitro metabolism of rivaroxaban, a novel, oral, direct factor Xa inhibitor for the prevention and treatment of thromboembolic disorders, was investigated in several species, including humans. The objective of this study was to elucidate metabolite structures and identify the metabolic pathways to provide support for in vivo safety and clinical studies. [(14)C]Rivaroxaban was incubated with liver microsomes and hepatocytes of rats, dogs, and humans. The samples were analyzed by high-performance liquid chromatography-(14)C-tandem mass spectroscopy, to generate metabolite profiles and propose or confirm the structures of the metabolites formed. In vitro metabolite profiles showed no major differences between species. The main oxidative metabolic pathways identified for all species were hydroxylation at the morpholinone moiety (M-2, M-3, and M-8) and to a lesser extent at the oxazolidinone moiety (M-9). M-2 was the main metabolite in all microsomal incubations. M-1, a morpholinone ring-opened product formed by further oxidation of M-2, was the main metabolite in all hepatocyte incubations. Other pathways were amide hydrolysis at the morpholinone ring (M-7) and the chlorothiophene amide moiety (M-13 and M-15). In hepatocytes, M-13 was readily conjugated with glycine, leading to M-4. The metabolic fate of unlabeled M-15 was investigated separately. Incubations with human liver microsomes and hepatocytes showed that M-15 was first oxidized to the aldehyde intermediate M-16 and subsequently reduced to M-17 (alcohol) or oxidized to M-18 (carboxylic acid). No metabolism at the chlorothiophene moiety itself was found. Overall, rivaroxaban showed no species differences in metabolism, with different independent metabolic pathways and no formation of reactive metabolites.

Increased inorganic phosphate induces human endothelial cell apoptosis in vitro

Chronic kidney disease with hyperphosphatemia is associated with accelerated atherosclerosis and endothelial dysfunction. However, the contribution of high serum phosphate levels to endothelial injury is incompletely understood. The aim of this work was to evaluate the responses of endothelial cells to elevated levels of extracellular phosphate in vitro. High phosphate in concentrations similar to those observed in uremia-associated hyperphosphatemia (>2.5 mM) induced apoptosis in two endothelial cell lines (EAhy926 cells and GM-7373 cells). This effect was enhanced when cells were incubated for 24 h in the presence of 2.8 mM calcium instead of 1.8 mM. By treating cells with 0.5 or 1.0 mM phosphonoformic acid, an inhibitor of the phosphate transporter, death was completely prevented. The process of phosphate-induced apoptosis was further characterized by increased oxidative stress, as detected by increased ROS generation and disruption of the mitochondrial membrane potential at approximately 2 h after treatment, followed by caspase activation. These findings show that hyperphosphatemia causes endothelial cell apoptosis, a process that impairs endothelial integrity. Endothelial cell injury induced by high phosphate concentrations may be an initial event leading to vascular complications in patients with chronic kidney disease.