Discovery of novel pyrazoline insecticides.

Background: The pyrazoline insecticides, invented by Philips Duphar in the 1970s, provide excellent control of lepidopterans and coleopterans and introduced a novel mode of action (MoA) as sodium-channel-blocking insecticides, but were not commercialized due to unacceptable persistence. This MoA is less explored, with only two successfully commercialized insecticides derived from the pyrazoline class - the oxadiazine indoxacarb from FMC (developed by DuPont) and the semicarbazone metaflumizone, co-developed by BASF and Nihon Nohyaku.

Results: The design and synthesis of novel pyrazoline insecticides with improved biological efficacy and favorable environmental fate profile are described.

The novel pyridazine pyrazolecarboxamide insecticide dimpropyridaz inhibits chordotonal organ function upstream of TRPV channels.

Background: Pyridazine pyrazolecarboxamides (PPCs) are a novel insecticide class discovered and optimized at BASF. Dimpropyridaz is the first PPC to be submitted for registration and controls many aphid species as well as whiteflies and other piercing-sucking insects.

Results: Dimpropyridaz and other tertiary amide PPCs are proinsecticides that are converted in vivo into secondary amide active forms by N-dealkylation.

Insecticides, biologics and nematicides: Updates to IRAC's mode of action classification - a tool for resistance management.

Insecticide resistance has been and continues to be a significant problem for invertebrate pest control. As such, effective insecticide resistance management (IRM) is critical to maintain the efficacy of current and future insecticides. A technical group within CropLife International, the Insecticide Resistance Action Committee (IRAC) was established 35 years ago (1984) as an international association of crop protection companies that today spans the globe.

Role of Anionic Surfactants in the Synthesis of Smart Microgels Based on Different Acrylamides.

We investigated the influence of two anionic surfactants, namely, sodium dodecyl sulfate and sodium decyl sulfate, on acrylamide-based microgels consisting of --propylacrylamide. In this context, the main focus was on the influence of surfactant addition on the size of the microgels. The surfactant was added to the reaction mixture before or during the polymerization at different points in time.

Smart Homopolymer Microgels: Influence of the Monomer Structure on the Particle Properties.

In this work, we compare the properties of smart homopolymer microgels based on -propylacrylamide (NNPAM), -isopropylacrylamide (NIPAM) and -isopropylmethacrylamide (NIPMAM) synthesized under identical conditions. The particles are studied with respect to size, morphology, and swelling behavior using scanning electron and scanning force microscopy. In addition, light scattering techniques and fluorescent probes are employed to follow the swelling/de-swelling of the particles.

Are there changes in characteristics and therapy of young patients with early-onset breast cancer in Germany over the last decade?

Purpose: The objective of the study is to investigate recent changes in patient characteristics and treatment procedures of young breast cancer patients over the last 10 years in Germany.

Methods: The study describes the data of 518 patients who were treated adjuvantly between 2008 and 2011 and participated in a resident mother-child program for rehabilitation (cohort II). The data includes TNM-categories, biology of tumor and therapies.

Characteristics and therapy of premenopausal patients with early-onset breast cancer in Germany.

Purpose: The objective of the study is to investigate what kind of tumors young, premenopausal breast cancer patients in Germany show at diagnosis and how they are treated adjuvantly in comparison with a normally distributed cohort.

Methods: The study describes the data of 535 patients who were treated adjuvantly between 2002 and 2006 and participated in a resident mother-child program for rehabilitation (Groemitz cohort). The data includes TNM categories, biology of tumor and therapies.

Experimental study of electrostatically stabilized colloidal particles: colloidal stability and charge reversal.

We consider the interaction of colloidal spheres in the presence of mono-, di-, and trivalent ions. The colloids are stabilized by electrostatic repulsion due to surface charges. The repulsive part of the interaction potential Ψ(d) is deduced from precise measurements of the rate of slow coagulation.

Complex functions of phosphatidylinositol 4,5-bisphosphate in regulation of TRPC5 cation channels.

The canonical transient receptor potential (TRPC) proteins have been recognized as key players in calcium entry pathways activated through phospholipase-C-coupled receptors. While it is clearly demonstrated that members of the TRPC3/6/7 subfamily are activated by diacylglycerol, the mechanism by which phospholipase C activates members of the TRPC1/4/5 subfamily remains a mystery. In this paper, we provide evidence for both negative and positive modulatory roles for membrane polyphosphoinositides in the regulation of TRPC5 channels.

Guanylyl cyclases: approaching year thirty.

Since its discovery in 1963, cyclic GMP (cGMP) has been shown to be a ubiquitous second messenger. The enzymes that catalyze the formation of cGMP from GTP, guanylyl cyclases, exist in soluble and particulate isoforms. An explosion in the number of known isoforms, gene disruption, identification of new inhibitors and activators and finally the resolution of the structure of adenylyl cyclases have all provided important clues about the structure and function of guanylyl cyclases.

Role of the store-operated calcium entry proteins Stim1 and Orai1 in muscarinic cholinergic receptor-stimulated calcium oscillations in human embryonic kidney cells.

We have investigated the nature of the Ca2+ entry supporting [Ca2+]i oscillations in human embryonic kidney (HEK293) cells by examining the roles of recently described store-operated Ca2+ entry proteins, Stim1 and Orai1. Knockdown of Stim1 by RNA interference (RNAi) reduced the frequency of [Ca2+]i oscillations in response to a low concentration of methacholine to the level seen in the absence of external Ca2+. However, knockdown of Stim1 did not block oscillations in canomical transient receptor potential 3 channel (TRPC3)-expressing cells and did not affect Ca2+ entry in response to arachidonic acid.

Large store-operated calcium selective currents due to co-expression of Orai1 or Orai2 with the intracellular calcium sensor, Stim1.

The molecular nature of store-operated Ca(2+)-selective channels has remained an enigma, due largely to the continued inability to convincingly demonstrate Ca(2+)-selective store-operated currents resulting from exogenous expression of known genes. Recent findings have implicated two proteins, Stim1 and Orai1, as having essential roles in store-operated Ca(2+) entry across the plasma membrane. However, transient overexpression of these proteins on their own results in little or no increase in store-operated entry.

The mammalian TRPC cation channels.

Transient Receptor Potential-Canonical (TRPC) channels are mammalian homologs of Transient Receptor Potential (TRP), a Ca(2+)-permeable channel involved in the phospholipase C-regulated photoreceptor activation mechanism in Drosophila. The seven mammalian TRPCs constitute a family of channels which have been proposed to function as store-operated as well as second messenger-operated channels in a variety of cell types. TRPC channels, together with other more distantly related channel families, make up the larger TRP channel superfamily.

Negative regulation of TRPC3 channels by protein kinase C-mediated phosphorylation of serine 712.

TRPC3 is a nonselective cation channel member of the "canonical" transient receptor potential (TRPC) family whose members are activated by phospholipase C-coupled receptors. TRPC3 can be activated by the diacylglycerol analog 1-oleoyl-2-acetyl-sn-glycerol (OAG) in a protein kinase C-independent manner. On the other hand, phorbol 12-myristate 13-acetate (PMA) inhibits OAG-mediated TRPC3 channel activation, suggesting that phosphorylation of TRPC3 by protein kinase C is a mechanism of receptor-mediated negative feedback.

Obligatory role of Src kinase in the signaling mechanism for TRPC3 cation channels.

Members of the canonical transient receptor potential (TRPC) subfamily of cation channels are candidates for capacitative and non-capacitative Ca2+ entry channels. When ectopically expressed in cell lines, TRPC3 can be activated by phospholipase C-mediated generation of diacylglycerol or by addition of synthetic diacylglycerols, independently of Ca2+ store depletion. Apart from this mode of regulation, little is known about other receptor-dependent signaling events that modulate TRPC3 activity.

Signalling mechanisms for TRPC3 channels.

The putative ion channel subunits TRPC3, TRPC6 and TRPC7 comprise a structurally related subgroup of the family of mammalian TRPC channels. As is the case for the founding member of the TRPC family, Drosophila TRP, the ion channels formed by these proteins appear to be activated in some manner downstream of phospholipase C (PLC). Earlier studies indicating that TRPC3 could be activated by depletion of intracellular stores (i.

Mechanisms of phospholipase C-regulated calcium entry.

In a variety of cell types, activation of phospholipase C-linked receptors results in the generation of intracellular Ca2+ signals comprised of components of both intracellular Ca2+ release, and enhanced entry of Ca2+ across the plasma membrane. This entry of Ca2+ occurs by either of two general mechanisms: the release of stored Ca2+ can activate, by an unknown mechanism, store-operated channels in the plasma membrane, a process known as capacitative calcium entry. Alternatively, second messengers generated at the plasma membrane can activate Ca2+ channels more directly, a non-capacitative calcium entry process.

A calmodulin/inositol 1,4,5-trisphosphate (IP3) receptor-binding region targets TRPC3 to the plasma membrane in a calmodulin/IP3 receptor-independent process.

Conformational coupling with the inositol 1,4,5-trisphosphate (IP3) receptor has been suggested as a possible mechanism of activation of TRPC3 channels and a region in the C terminus of TRPC3 has been shown to interact with the IP3 receptor as well as calmodulin (calmodulin/IP3 receptor-binding (CIRB) region). Here we show that internal deletion of 20 amino acids corresponding to the highly conserved CIRB region results in the loss of diacylglycerol and agonist-mediated channel activation in HEK293 cells. By using confocal microscopy to examine the cellular localization of Topaz fluorescent protein fusion constructs, we demonstrate that this loss in activity is caused by faulty targeting of CIRB-deleted mutants to intracellular compartments.

Expression level of the canonical transient receptor potential 3 (TRPC3) channel determines its mechanism of activation.

Studies on the mechanism of activation of canonical transient receptor potential (TRPC) channels have often yielded conflicting results. In the current study, we have investigated the influence of expression level on the mode of regulation of TRPC3 channels. At relatively low levels of expression in DT40 chicken B-lymphocytes, TRPC3 was activated by the depletion of Ca2+ stores.

An inositol 1,4,5-trisphosphate receptor-dependent cation entry pathway in DT40 B lymphocytes.

We examined the roles of inositol 1,4,5-trisphosphate (IP3) receptors (IP3R) in calcium signaling using DT40 B lymphocytes, and a variant lacking the three IP3R isoforms (IP3R-KO). In wild-type cells, B cell receptor (BCR) stimulation activates a cation entry route that exhibits significantly greater permeability to Ba2+ than does capacitative calcium entry. This cation entry is absent in IP3R-KO cells.

The guanylyl cyclase family at Y2K.

During the 1980s the purification, cloning, and expression of various forms of guanylyl cyclase (GC) revealed that they served as receptors for extracellular signals. Seven membrane forms, which presumably exist as homodimers, and four subunits of apparent heterodimers (commonly referred to as the soluble forms) are known, but in animals such as nematodes, much larger numbers of GCs are expressed. The number of transmembrane segments (none, one, or multiple) divide the GC family into three groups.

The cloning and expression of a new guanylyl cyclase orphan receptor.

A novel membrane form of guanylyl cyclase (GC-G) has been identified through the isolation of a full-length cDNA clone; it is predicted to contain an extracellular ligand binding domain, a single transmembrane segment, and intracellular protein kinase-like and cyclase catalytic domains. That GC-G represents a guanylyl cyclase was confirmed by both transient expression in COS-7 cells and stable expression in H293 cells. Endogenous cyclic GMP concentrations of transfected or stable cells, however, were much higher than control cells, suggesting an inability of the cells to effectively regulate GC-G cyclase activity.

New insights on the functions of the guanylyl cyclase receptors.

The discovery of at least 29 genes encoding putative guanylyl cyclases in Caenorhabditis elegans has raised the question as to whether there are numerous receptors yet to be discovered in the mammal. The nematode, however, not only seems ideal to study guanylyl cyclase receptor localization and function, given the large variety of isoforms, but also leads to possible identification of ligands for orphan guanylyl cyclases by the use of genetic and behavioral assays. A recent powerful approach to describe the function of different guanylyl cyclase isoforms in mammals has been the disruption of the corresponding genes in the mouse.

The cloning of a Caenorhabditis elegans guanylyl cyclase and the construction of a ligand-sensitive mammalian/nematode chimeric receptor.

Substantial guanylyl cyclase activity was detected in membrane fractions prepared from Caenorhabditis elegans (100 pmol cGMP/min/mg at 20 degrees C or 500 pmol cGMP/min/mg at 37 degrees C), suggesting the potential existence of orphan cyclase receptors in the nematode. Using degenerate primers, a cDNA clone encoding a putative membrane form of the enzyme (GCY-X1) was obtained. The apparent cyclase was most closely related to the mammalian natriuretic peptide receptor family, and retained cysteine residues conserved within the extracellular domain of the mammalian receptors.