Publications by authors named "David P Thompson"

: The prevention of falls and fall-related fractures following menopause is an important health initiative. The Fracture Prevention Screening Algorithm (FPSA) uniquely uses fracture risk to prompt fall risk assessment to classify both fall and fracture risk in individuals. The purpose of this study was to determine whether use of the FPSA accurately predicted self-reported falls in post-menopausal women over one year.

View Article and Find Full Text PDF

The purpose of this research is to describe Texas educator sexual misconduct (ESM) by examining 8 years of sanctions issued to educators (N = 1415) for either sexual misconduct or inappropriate relationships with students or minors. We first examine Texas ESM from the perspective of quality database construction and then describe the demographic characteristics of educators sanctioned for ESM between 2008 and 2016. Differences in the demographic characteristics of educators sanctioned for ESM vary according to the definition of ESM employed by the state education agency.

View Article and Find Full Text PDF

The objective of the current study was to establish an in vitro screen and a highly sensitive analytical assay to delineate key physicochemical properties that favor compound bioaccumulation in the L3 life stage of a Haemonchus contortus isolate. Time-dependent studies revealed that absorption and elimination kinetics during the first 6 hr of exposure were sufficient to achieve maximum bioaccumulation for the majority of compounds tested. In subsequent studies, the larvae were incubated for 6 hr in a medium containing 146 compounds (5 μM initial concentration), including both human and veterinary medicines, characterized by a broad range of physicochemical properties.

View Article and Find Full Text PDF

Startect(®) is a novel anthelmintic combination of derquantel and abamectin. It is hypothesized that derquantel and abamectin interact pharmacologically. We investigated the effects of derquantel, abamectin and their combination on somatic muscle nicotinic acetylcholine receptors and pharyngeal muscle glutamate gated chloride receptor channels of Ascaris suum.

View Article and Find Full Text PDF

Biochemical and biophysical research tools are used to define the developmental dynamics of numerous cell lineages from a variety of tissues relevant to meat quality. With respect to the adipose cell lineage, much of our present understanding of adipogenesis and lipid metabolism was initially determined through the use of these methods, even though the in vitro or molecular environments are far removed from the tissues of meat animals. This concise review focuses on recent cellular and molecular biology-related research with adipocytes, and how the research might be extended to the endpoint of altering red meat quality.

View Article and Find Full Text PDF

Allatostatins are the largest family of known arthropod neuropeptides. To date more than 150 different arthropod type-A allatostatins have been identified and are characterized by the C-terminal signature, (Y/F)XFG(L/I)amide. Using specific allatostatin antisera, positive immunoreactivity has been identified within the central and peripheral nervous systems of the flatworm (platyhelminth) Procerodes littoralis and the roundworm (nematode) Panagrellus redivivus.

View Article and Find Full Text PDF

FMRFamide-related peptides are common to a wide variety of invertebrate species, including helminths and arthropods. In arthropods, five distinct FMRFamide-related peptide subfamilies are recognised: the myosuppressins, extended-FLRFamides, -FMRFamides, -RFamides, and sulfakinins, members of which induce potent and diverse myotropic effects. Whilst >80 FMRFamide-related peptides have been identified in nematodes, only four FMRFamide-related peptides have been characterised from flatworms.

View Article and Find Full Text PDF

Prospects for discovering new antiparasitic drugs for veterinary medicine in the coming century will be determined by economic, social and scientific factors. Consolidation in the pharmaceutical industry in general, and the animal health industry in particular, changes the business conditions in which drug discovery for veterinary medicine occurs. Social pressures on traditional animal agriculture and companion animal ownership have shifted the interest of animal companies primarily to pet medicine.

View Article and Find Full Text PDF

Patch-clamp recordings from muscle- and cuticle-facing hypodermal membranes of the gastrointestinal nematode Ascaris suum reveal a high-conductance, voltage- sensitive Ca(2+) -dependent Cl(-) channel. The hypodermal channel has a conductance of 195 pS in symmetrical 160 mM NaCl. The open probability of the channel is highly voltage-sensitive, and channel activity is not observed when Ca(2+) is reduced to <100 microM.

View Article and Find Full Text PDF

FMRFamide-related peptides are widespread among the Nematoda. Among them is a family of extended PNFLRFamide peptides encoded on the flp-1 peptide precursor gene in Caenorhabditis elegans. The most studied peptide from this series is SDPNFLRFamide (PF1).

View Article and Find Full Text PDF

Here we describe the actions of the peptide Lys-Pro-Asn-Phe-Ile-Arg-Phe-NH(2), or PF4, on inside-out membrane patches (n=164), recorded from vesicles derived from Ascaris suum somatic muscle cells. We observed numerous, small-amplitude Cl(-) channels in the membrane patches. The conductance of the Cl(-) channels ranged from 1.

View Article and Find Full Text PDF

Oxindole alkaloids in the paraherquamide/marcfortine family exhibit broad-spectrum anthelmintic activity that includes drug-resistant strains of nematodes. Paraherquamide (PHQ), 2-deoxoparaherquamide (2DPHQ), and close structural analogs of these compounds rapidly induce flaccid paralysis in parasitic nematodes in vitro, without affecting adenosine triphosphate (ATP) levels. The mechanism of action of this anthelmintic class was investigated using muscle tension and microelectrode recording techniques in isolated body wall segments of Ascaris suum.

View Article and Find Full Text PDF

Paraherquamide is a novel natural anthelmintic product with a mode of action that is incompletely characterized. Nicotine and cholinergic-anthelmintic agonists of different chemical classes were used to produce contraction in Ascaris muscle strips. Paraherquamide and a semisynthetic derivative, 2-deoxy-paraherquamide, antagonized these responses.

View Article and Find Full Text PDF

Three distinct chemical classes for the control of gastrointestinal nematodes are available: benzimidazoles, imidazothiazoles, and macrocyclic lactones. The relentless development of drug resistance has severely limited the usefulness of such drugs and the search for a new class of compounds preferably with a different mode of action is an important endeavor. Marcfortine A (1), a metabolite of Penicillium roqueforti, is structurally related to paraherquamide A (2), originally isolated from Penicillium paraherquei.

View Article and Find Full Text PDF

Current problems of drug resistance in parasites and pests demand the identification of new targets and their exploitation through novel drug design and development programs. Neuropeptide signaling systems in helminths (nematodes and platyhelminths = worms) and arthropods are well developed and complex, play a crucial role in many aspects of their biology, and appear to have significant potential as targets for novel drugs. The best-known neuropeptide family in invertebrates is the FMRFamide-related peptides (FaRPs).

View Article and Find Full Text PDF

N-Methyloctadepsipeptides attached to an oxime resin were cyclized by heating them in refluxing ethyl acetate for 2 days to give cyclodepsipeptide PF1022A analogues. By using this method, we generated a small library of PF 1022A analogues (2), several of which possessed anthelmintic activity, based on an in vitro assay.

View Article and Find Full Text PDF