Spatial population genomics of a recent mosquito invasion.

Population genomic approaches can characterize dispersal across a single generation through to many generations in the past, bridging the gap between individual movement and intergenerational gene flow. These approaches are particularly useful when investigating dispersal in recently altered systems, where they provide a way of inferring long-distance dispersal between newly established populations and their interactions with existing populations. Human-mediated biological invasions represent such altered systems which can be investigated with appropriate study designs and analyses.

Developing the Ce and La pair as companion positron emission tomography diagnostic isotopes for Ac and Th radiotherapeutics.

Developing targeted α-therapies has the potential to transform how diseases are treated. In these interventions, targeting vectors are labelled with α-emitting radioisotopes that deliver destructive radiation discretely to diseased cells while simultaneously sparing the surrounding healthy tissue. Widespread implementation requires advances in non-invasive imaging technologies that rapidly assay therapeutics.

A reverse U/Th radionuclide generator for targeted alpha therapy applications.

Purpose: Thorium-226 (half-life 30.6 m) is a radionuclide of interest for use in targeted alpha therapy applications. Due to its short half-life, Th must be provided through a radionuclide generator system from its parent U (20.

Extraction chromatography of Ac and lanthanides on N,N-dioctyldiglycolamic acid /1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide solvent impregnated resin.

The alpha-emitter Ac (t = 9.92 d) is currently under development for targeted alpha-particle therapy of cancer, and accelerator production of Ac via proton irradiation of thorium targets requires robust separations of Ac from chemically similar fission product lanthanides. Additionally, the lanthanide elements represent critical components in modern technologies, and radiolanthanides such as Nd (t = 3.

A Solid-State Support for Separating Astatine-211 from Bismuth.

Increasing access to the short-lived α-emitting radionuclide astatine-211 (At) has the potential to advance targeted α-therapeutic treatment of disease and to solve challenges facing the medical community. For example, there are numerous technical needs associated with advancing the use of At in targeted α-therapy, e.g.

Production of Pa by proton irradiation of Th at the LANL isotope production facility: Precursor of U for targeted alpha therapy.

Uranium-230 (t = 20.8 d) is an alpha-emitting radionuclide that has potential application in targeted alpha therapy (TAT) of cancer. Its parent isotope Pa (t = 17.

Large-Scale Production of Te and Sb for Radiopharmaceutical Applications.

Radionuclides find widespread use in medical technologies for treating and diagnosing disease. Among successful and emerging radiotherapeutics, Sb has unique potential in targeted therapeutic applications for low-energy electron-emitting isotopes. Unfortunately, developing Sb-based drugs has been slow in comparison to other radionuclides, primarily due to limited accessibility.

Separation of Protactinium Employing Sulfur-Based Extraction Chromatographic Resins.

Protactinium-230 ( t = 17.4 d) is the parent isotope of U ( t = 20.8 d), a radionuclide of interest for targeted alpha therapy (TAT).

Synthesis and radiometric evaluation of diglycolamide functionalized mesoporous silica for the chromatographic separation of actinides Th, Pa and U.

The separation of Th, Pa, and U is of high importance in many applications including nuclear power, nuclear waste, environmental and geochemistry, nuclear forensics and nuclear medicine. Diglycolamide (DGA)-based resins have shown the ability to separate many elements, however, these resins consist of non-covalent impregnation of the DGA molecules on the resin backbone resulting in co-elution of the extraction molecule during separation cycles, therefore limiting their long-term and repeated use. Covalently binding the DGA molecules onto silica is one way to overcome this issue.

Separation of 103Ru from a proton irradiated thorium matrix: A potential source of Auger therapy radionuclide 103mRh.

Ruthenium-103 is the parent isotope of 103mRh (t1/2 56.1 min), an isotope of interest for Auger electron therapy. During the proton irradiation of thorium targets, large amounts of 103Ru are generated through proton induced fission.

Chromatographic separation of the theranostic radionuclide Ag from a proton irradiated thorium matrix.

Column chromatographic methods have been developed to separate no-carrier-added Ag from proton irradiated thorium targets and associated fission products as an ancillary process to an existing Ac separation design. Herein we report the separation of Ag both prior and subsequent to Ac recovery using CL resin, a solvent impregnated resin (SIR) that carries an organic solution of alkyl phosphine sulfides (RP = S) and alkyl phosphine oxides (RP = O). The recovery yield of Ag was 93 ± 9% with a radiochemical purity of 99.

Simultaneous Separation of Actinium and Radium Isotopes from a Proton Irradiated Thorium Matrix.

A new method has been developed for the isolation of Ra, in high yield and purity, from a proton irradiated Th matrix. Herein we report an all-aqueous process using multiple solid-supported adsorption steps including a citrate chelation method developed to remove >99.9% of the barium contaminants by activity from the final radium product.

Proton-induced production and radiochemical isolation of Ti from scandium metal targets for Ti/Sc generator development.

Scandium-44g (half-life 3.97h) shows promise for application in positron emission tomography (PET), due to favorable decay parameters. One of the sources of Sc is the Ti/Sc generator, which can conveniently provide this radioisotope on a daily basis at a diagnostic facility.

Bulk production and evaluation of high specific activity Re for cancer therapy using enriched WO targets in a proton beam.

Introduction: Rhenium-186g (t = 3.72 d) is a β emitting isotope suitable for theranostic applications. Current production methods rely on reactor production by way of the reaction Re(n,γ)Re, which results in low specific activities limiting its use for cancer therapy.

Separation of Ti from proton irradiated scandium by using solid-phase extraction chromatography and design of Ti/Sc generator system.

Scandium-44g (half-life 3.97h [1]) shows promise for positron emission tomography (PET) imaging of longer biological processes than that of the current gold standard, F, due to its favorable decay parameters. One source of Sc is the long-lived parent nuclide Ti (half-life 60.

In ovo vaccination of chicken embryos with experimental Newcastle disease and avian influenza oil-emulsion vaccines.

Inactivated oil-emulsion (OE) Newcastle disease (ND) and avian influenza (AI) vaccines were injected into 18-day-old white rock (WR) and white leghorn (WL) chicken embryos to evaluate their immunologic efficacy and their effects on hatchability. Embryonating eggs were inoculated at 1.5 inches depth with various vaccine volumes and antigen concentrations.

Pathogenicity and diagnosis of H5N2 Mexican avian influenza viruses in chickens.

Chickens were inoculated with one of five H5N2 Mexican-origin avian influenza virus (AIV) isolates to determine their pathogenicity for chickens and to determine the ability of routine virologic and serologic tests to detect infections. In laboratory infections, three AIVs, H5/94, M5/94, and J12/94, produced sporadic illness and death and were categorized as mildly pathogenic. Q1/95 produced illness and death in all inoculated chickens and was categorized as highly lethal and highly pathogenic (HP).

Comparative pathology of chickens experimentally inoculated with avian influenza viruses of low and high pathogenicity.

Pathologic changes and distribution of viral antigen as determined by immunohistochemistry were compared among 4-wk-old specific-pathogen-free chickens inoculated intratracheally with avian influenza virus (AIV) isolates of either low or high pathogenicity. Viruses of low pathogenicity, previously characterized as mildly pathogenic (MP), included A/chicken/Pennsylvania/21525/83 (H5N2) (MP-Penn) and A/chicken/Alabama/7395/75 (H4N8) (MP-Alab). Viruses of high pathogenicity included A/chicken/Pennsylvania/1370/83 (H5N2), A/chicken/Victoria/A185/85 (H7N7), and A/turkey/Ontario/7732/66 (H5N9).

Pathogenicity of three avian influenza viruses for Leghorn hens of different ages.

Pronounced host effects on clinical responses to influenza virus infection were not observed in any of seven trials in which young (26-43 weeks) and olf (65-94 weeks) leghorn hens were inoculated with low pathogenic subtype H5N2, H4N8, or H3N2 virus. In two of seven trials, where hens were infected with H4N8 or H3N2 virus, morbidity rates were slightly higher for old hens than for young hens. These observations indicate that host age effects of the severity of uncomplicated influenza virus infections are likely to be minimal in sexually mature chickens.

Assessment of the ability of ratite-origin influenza viruses to infect and produce disease in rheas and chickens.

Pathobiologic characteristics were determined for three mildly pathogenic (MP) ratite-origin avian influenza viruses (AIVs). Ratite-origin AIVs produced respiratory disease in rheas, and virus was reisolated from oropharyngeal and cloacal swabs on days 2-6 postinoculation. Inoculation of two ratite-origin AIVs in the upper respiratory tract of chickens resulted in viral infections, but the mean chicken infectious dose (CID50) for A/emu/Texas/39924/93 (H5N2) (Emu/Texas) virus was 500-fold lower than the CID50 for the A/rhea/North Carolina/39482/93 (H7N1) virus.

An Arg-Lys insertion at the hemagglutinin cleavage site of an H5N2 avian influenza isolate.

Recent isolations of H5N2 subtype avian influenza (AI) viruses in North America have raised questions concerning their origin, transmission to commercial poultry, and potential for virulence. One ratite-origin isolate of low pathogenicity, A/emu/TX/39924/93 (H5N2), was subjected to a procedure that rapidly selects and/or amplifies highly pathogenic (HP) strains. The resulting highly virulent derivative had an altered hemagglutinin (HA) gene containing an additional six nucleotides at position 970-975 in the HA1 coding region.

Re-evaluation of the pathogenicity of A/chicken/Alabama/75 (H4N8) influenza virus.

Avian influenza (AI) virus A/chicken/Alabama/7395/75 (H4N8), a putatively non-pathogenic virus associated with a self-limiting outbreak of severe disease in commercial layers, was selectively passed in chickens or in cell cultures and then in chickens to determine whether virus with increased pathogenicity would emerge. When 20 derivatives of the parental virus were each inoculated intranasally and intratracheally in leghorn hens, mortality rates ranged from zero (0/24) to 25% (6/24); mortality was 4% (1/24) for hens inoculated with the parental virus. Many virus reisolates (51/144) from hens that died exhibited high pathogenicity, killing at least six of eight intravenously inoculated 4-week-old chickens.

Simulation of maternal immunity by inoculation of immune yolk preparations into the yolk sac of 1-day-old chickens.

Yolk harvested from eggs laid by hens hyperimmunized with killed Newcastle disease virus (NDV) was inoculated into the yolk sac of 1-day-old specific-pathogen-free (SPF) chickens. Serum hemagglutination-inhibition antibody titers reached maximum levels 1 to 4 days after yolk inoculation and declined at a rate similar to that reported for naturally acquired maternal antibody. Expected levels of immune interference were observed when yolk-inoculated chickens were vaccinated with a conventional oil-emulsion NDV vaccine.

Emergence of highly pathogenic virus during selective chicken passage of the prototype mildly pathogenic chicken/Pennsylvania/83 (H5N2) influenza virus.

The prototype mildly pathogenic A/chicken/Pennsylvania/21525/83 (H5N2) avian influenza virus, which was isolated more than 5 months before the emergence of highly pathogenic virus in the major 1983 Pennsylvania outbreak, was examined for the presence of minority subpopulations of highly pathogenic virus. Selective serial passage of the parental mildly pathogenic virus in leghorn hens did not lead to recovery of highly pathogenic virus. However, several highly pathogenic reisolates were recovered from hens inoculated with either of two mildly pathogenic virus clones selected for their ability to efficiently produce plaques in trypsin-free chicken embryo fibroblasts.

Amantadine resistance among hemagglutinin subtype 5 strains of avian influenza virus.

Several avian influenza virus strains of hemagglutinin subtype 5 were assayed for sensitivity to the antiviral drug amantadine. Most strains exhibited little sensitivity to the drug as measured by plaque reduction. The A/Chicken/Scotland/59 (CS59), however, was highly sensitive, making it easily distinguishable from the other H5 strains.