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Richard A Moore

Publications and source records attributed to Richard A Moore.

13 recordsLinked to original sources
PubMed2006

Cell-mediated immune responses to COPV early proteins.

Cell-mediated immunity plays a key role in the regression of papillomavirus-induced warts and intra-epithelial lesions but the target antigens that induce this response are not clear. Canine oral papillomavirus (COPV) infection of the oral cavity in dogs is a well-characterized model of mucosal papillomavirus infection that permits analysis of the immune events during the infectious cycle. In this study we show that during the COPV infectious cycle, systemic T cell responses to peptides of several early proteins particularly the E2 protein, as assayed by delayed type hypersensitivity, lymphoproliferation and IFN-gamma ELISPOT, can be detected. The maximal response occurs in a narrow time window that coincides with maximal viral DNA replication and wart regression: thereafter, systemic T cell responses to early proteins decline quite rapidly. Vaccination using particle-mediated immunotherapeutic delivery (PMID) of codon-modified COPV E2 and E1 genes induces strong antigen-specific cell-mediated immune responses in the vaccinated animals. These data show that therapeutic immunization by PMID with codon-modified E2 is completely effective, that to E1 is partially protective, that this correlates with the intensity of antigen-specific cell-mediated immune responses and, further, they emphasize the importance of these responses and the route of immunization in the generation of protective immunity.

Animals↗
PubMed2006

Formulation considerations for the development of medications with abuse potential.

The availability of increasingly sophisticated drug formulations and delivery devices has created new opportunities in drug development. These newer approaches can result in improved drug bioavailability, or they can alter key pharmacokinetic parameters in such a way as to decrease dosing interval, decrease variability, or blunt maximal concentrations that are associated with adverse events of particular concern. Special formulations or devices can also provide for easier or more convenient dosing in subpopulations of interest, such as children or the elderly. Although the key principles of abuse potential assessment and the underlying neurochemistry and pharmacology are relatively well understood, evaluation of the influences of drug formulation have received much less study. Because dose and formulation - and even the therapeutic indication - are refined over the course of development, it is usually difficult to conduct more than a cursory evaluation of the influence of formulation on the underlying abuse potential of the active pharmaceutical ingredient. Industrial sponsors would benefit from further research in areas of formulation science and pharmacokinetics that would improve the predictability of prescription drug abuse. In particular, validation of new pharmacokinetic parameters and standardization of methods to understand the consequences of product tampering could assist in gaining a better assessment of risk for controlled release formulations. Such methods could apply not only to innovator products, but also to those wishing to develop generic versions with similar pharmaceutical performance. This article proposes several factors that may be of use to industrial sponsors in making formulation choices for drugs with the potential for abuse.

Biological Availability↗
PubMed2006

The mviN homolog in Burkholderia pseudomallei is essential for viability and virulence.

The virulence factors of Burkholderia pseudomallei, the causative agent of melioidosis, are not fully understood. We have identified a gene with homology to the Salmonella typhimurium mouse virulence gene, mviN, a member of the mouse virulence factor family. Expression studies with an insertional mutant containing a lux operon demonstrated that the expression of the gene is influenced by free-iron availability in the media and by growth phase. The mutant displayed an increased LD50 value in the hamster infection model and a loss of the ability to invade human lung epithelial cells. The mutant has a slower growth rate than that of the wild type. Both defects were restored to various degrees when complemented in trans with the mviN gene. The mutant contains an insertion at 1229 bp of the 1548 bp gene, resulting in a truncated protein that is presumably responsible for the defects. Deletion mutants of the entire B. pseudomallei mviN gene were obtained only in the presence of the complement vector. This result and the inability of the complemented deletion mutant to lose the plasmid in the absence of antibiotic selection suggest that the gene is essential to B. pseudomallei.

Animals↗
PubMed2005

Genome-wide expression analysis of iron regulation in Burkholderia pseudomallei and Burkholderia mallei using DNA microarrays.

Burkholderia pseudomallei and B. mallei are the causative agents of melioidosis and glanders, respectively. As iron regulation of gene expression is common in bacteria, in the present studies, we have used microarray analysis to examine the effects of growth in different iron concentrations on the regulation of gene expression in B. pseudomallei and B. mallei. Gene expression profiles for these two bacterial species were similar under high and low iron growth conditions irrespective of growth phase. Growth in low iron led to reduced expression of genes encoding most respiratory metabolic systems and proteins of putative function, such as NADH-dehydrogenases, cytochrome oxidases, and ATP-synthases. In contrast, genes encoding siderophore-mediated iron transport, heme-hemin receptors, and a variety of metabolic enzymes for alternative metabolism were induced under low iron conditions. The overall gene expression profiles suggest that B. pseudomallei and B. mallei are able to adapt to the iron-restricted conditions in the host environment by up-regulating an iron-acquisition system and by using alternative metabolic pathways for energy production. The observations relative to the induction of specific metabolic enzymes during bacterial growth under low iron conditions warrants further experimentation.

Adaptation, Physiological↗
PubMed2005

Protection of beagle dogs from mucosal challenge with canine oral papillomavirus by immunization with recombinant adenoviruses expressing codon-optimized early genes.

Replication-deficient adenoviral (rAd5) vaccines containing codon-optimized E1, E2, E4, and E7 genes of canine oral papillomavirus (COPV) were tested singly or in combination to determine which vaccines could protect against mucosal challenge with COPV. In three studies, groups of 4-6 beagle dogs were immunized subcutaneously (s.c.) with 10(11) rAd5 at 8-10 weeks and 4-6 weeks prior to challenge with infectious COPV particles at multiple oral mucosal sites. Control dogs were immunized with equivalent doses of rAd5 expressing human papillomavirus (HPV) type 16 L1 (rAd5-HPV-16 L1). In the first study, complete protection from COPV-induced papillomas was achieved by immunization with rAd5 vaccine combinations expressing either E1 + E2 or E1 + E2 + E4 + E7; whereas two of six dogs immunized with rAd5-E4 + rAd5-E7 and six of six rAd5-HPV16-L1-immunized control dogs developed oral papillomas. In two subsequent studies, rAd5-E1 and rAd5-E2 vaccines were tested singly or in combination to assess levels of protective immunity to COPV challenge. Subcutaneous immunization with either one or two doses of rAd5 expressing the COPV E1 and E2 genes could protect > 90% of challenged dogs from wart formation. In contrast, all eight dogs immunized with rAd5-HPV-16 L1 developed papillomas at multiple sites. Protection was accompanied by significant IFN-gamma responses to COPV E1 and E2 peptides. Partial protection was conferred by two immunizations with either rAd5-E1 (6 of 9 protected) or rAd5-E2 (8 of 9 protected). These data indicate that rAd5 expressing papillomavirus E1 and E2 proteins can induce strong protective responses even in outbred populations under practical immunization conditions.

Adenoviridae↗
PubMed2004

Contribution of gene loss to the pathogenic evolution of Burkholderia pseudomallei and Burkholderia mallei.

Burkholderia pseudomallei is the causative agent of melioidosis. Burkholderia thailandensis is a closely related species that can readily utilize l-arabinose as a sole carbon source, whereas B. pseudomallei cannot. We used Tn5-OT182 mutagenesis to isolate an arabinose-negative mutant of B. thailandensis. Sequence analysis of regions flanking the transposon insertion revealed the presence of an arabinose assimilation operon consisting of nine genes. Analysis of the B. pseudomallei chromosome showed a deletion of the operon from this organism. This deletion was detected in all B. pseudomallei and Burkholderia mallei strains investigated. We cloned the B. thailandensis E264 arabinose assimilation operon and introduced the entire operon into the chromosome of B. pseudomallei 406e via homologous recombination. The resultant strain, B. pseudomallei SZ5028, was able to utilize l-arabinose as a sole carbon source. Strain SZ5028 had a significantly higher 50% lethal dose for Syrian hamsters compared to the parent strain 406e. Microarray analysis revealed that a number of genes in a type III secretion system were down-regulated in strain SZ5028 when cells were grown in l-arabinose, suggesting a regulatory role for l-arabinose or a metabolite of l-arabinose. These results suggest that the ability to metabolize l-arabinose reduces the virulence of B. pseudomallei and that the genes encoding arabinose assimilation may be considered antivirulence genes. The increase in virulence associated with the loss of these genes may have provided a selective advantage for B. pseudomallei as these organisms adapted to survival in animal hosts.

Animals↗
PubMed2003

Therapeutic immunisation with COPV early genes by epithelial DNA delivery.

Following challenge with COPV (canine oral papillomavirus), DNA plasmids encoding COPV L1, E1 or E2 protein were delivered into oral mucosal and cutaneous sites in beagles using particle-mediated immunotherapeutic delivery (PMID). Two weeks post-challenge, a priming dose of 8 microg DNA was delivered followed by a booster dose after a further two weeks. A group of control dogs were vaccinated using plasmid DNA encoding Hepatitis B virus surface (HBVs) gene. All of the control animals developed warts at the vast majority of sites (94%). All of the animals given wild type L1, E1, or E2 developed warts at most sites (88%, 75%, and 88%, respectively). The animals given codon optimised E2 however, were protected from wart growth with only one tiny lesion seen on a single animal that persisted for only a few days. The E1 codon optimised group was also significantly protected with a far lower number of smaller warts (48%) that persisted for a shorter duration. These data suggest that therapeutic immunisation by PMID with papillomavirus early genes is effective and emphasizes the importance of antigen load in the generation of protective responses to papillomavirus proteins.

Animals↗
PubMed2003

Human papillomavirus type 16 E2- and L1-specific serological and T-cell responses in women with vulval intraepithelial neoplasia.

Human papillomavirus type 16 (HPV-16)-associated vulval intraepithelial neoplasia (VIN) is frequently a chronic, multifocal high-grade condition with an appreciable risk of progression to vulval cancer. The requirement to treat women with VIN has recently stimulated the use of immunotherapy with E6/E7 oncogene vaccines. Animal models have shown that E2 may also be a useful vaccine target for HPV-associated disease; however, little is known about E2 immunity in humans. This study investigated the prevalence of HPV-16 E2-specific serological and T-cell responses in 18 women with HPV-16-associated VIN and 17 healthy volunteers. E2 responses were determined by full-length E2-GST ELISA with ELISPOT and proliferation assays using E2 C-terminal protein. As positive controls, HPV-16 L1 responses were measured using virus-like particles (VLPs) and L1-GST ELISA with ELISPOT and proliferation using VLPs as antigen. The VIN patients all showed a strong serological response to L1 compared with the healthy volunteers by VLP (15/18 vs 1/17, P<0.001) and L1-GST ELISA (18/18 vs 1/17, P<0.001). In contrast, L1-specific cellular immune responses were detected in a significant proportion of controls but were more prevalent in the VIN patients by proliferation assay (9/17 vs 17/18, P<0.02) and interferon-gamma ELISPOT (9/17 vs 13/18, P=not significant). Similar and low numbers of patients and controls were seropositive for E2-specific Ig (2/18 vs 1/17). In spite of previous studies showing the immunogenicity of E2 in eliciting primary T-cell responses in vitro, there was a low prevalence of E2 responses in the VIN patients and controls (2/18 vs 0/17).

Adult↗
PubMed2003

Burkholderia pseudomallei class a beta-lactamase mutations that confer selective resistance against ceftazidime or clavulanic acid inhibition.

Burkholderia pseudomallei, the causative agent of melioidosis, is inherently resistant to a variety of antibiotics including aminoglycosides, macrolides, polymyxins, and beta-lactam antibiotics. Despite resistance to many beta-lactams, ceftazidime and beta-lactamase inhibitor-beta-lactam combinations are commonly used for treatment of melioidosis. Here, we examine the enzyme kinetics of beta-lactamase isolated from mutants resistant to ceftazidime and clavulanic acid inhibition and describe specific mutations within conserved motifs of the beta-lactamase enzyme which account for these resistance patterns. Sequence analysis of regions flanking the B. pseudomallei penA gene revealed a putative regulator gene located downstream of penA. We have cloned and sequenced the penA gene from B. mallei and found it to be identical to penA from B. pseudomallei.

3' Flanking Region↗
PubMed2002

Intraepithelial DNA immunisation with a plasmid encoding a codon optimised COPV E1 gene sequence, but not the wild-type gene sequence completely protects against mucosal challenge with infectious COPV in beagles.

DNA plasmids encoding the open reading frames of canine oral papillomavirus (COPV) nonstructural early genes E1, E2, or E7 protein were delivered into both oral mucosal and cutaneous epithelial sites in beagle dogs using particle-mediated immunotherapeutic delivery (PMID) technology. Control dogs were vaccinated with plasmid encoding either hepatitis B virus surface antigen (HBVs) or COPV L1. Using a prophylactic immunisation protocol, a priming dose of plasmid DNA was followed by a booster dose 6 weeks later. Four weeks after boost, all dogs were challenged with infectious COPV particles. Following viral challenge, as shown previously (M. A. Stanley et al., 2001, Vaccine 19, 2783-2792), mucosal papillomas developed in the negative-control HBVs vaccinated dogs, but all animals in the COPV L1 group were fully protected from disease development. In the early gene-vaccinated groups five of six in the E1-vaccinated dogs, two of six in E2-vaccinated dogs, and three of six in the E7-vaccinated beagles developed oral papillomas. Compared to the HBVs negative-control group the oral papillomas that did develop in the early-gene vaccinated beagles were significantly smaller, shorter in duration, and fewer in number. Taken together the disease burden was markedly reduced and this was statistically significant. In a second experiment one group of animals was vaccinated with plasmid encoding the wild-type COPV E1 gene, and a separate group was vaccinated with plasmid encoding a synthetic codon-optimised COPV E1 gene sequence. None of the codon-optimised E1-vaccinated animals developed papillomas at any challenge site. However, all animals vaccinated with wild-type E1 had papillomas. These data suggest that immunisation by PMID with papillomavirus early genes can significantly impact upon subsequent disease development and that full protection can be achieved using improved vectors encoding codon-optimised gene sequences perhaps emphasizing the importance of antigen load in the generation of protective responses to papillomavirus proteins.

Animals↗
PubMed2002

HIV/AIDS in correctional settings: a salient priority for the CDC and HRSA.

Correctional facilities constitute an excellent opportunity to provide treatment, care, and prevention services for a population that may not otherwise access these services. The Centers for Disease Control and Prevention (CDC) and the Health Resources and Services Administration (HRSA) recognize the public health importance of correctional settings and have begun to develop formal strategies to address the HIV/AIDS-relevant needs of incarcerated individuals. The Centers for Disease Control and Prevention and HRSA have implemented policies, activities, and strategic plans to reduce the HIV/AIDS disease burden among the high-risk populations that pass through the nation's prisons and jails. They have also collaborated to address the HIV/AIDS needs of incarcerated populations and have initiated processes for expanding collaboration on these issues to include other federal agencies and prevention partners.

Centers for Disease Control and Prevention, U.S.↗
PubMedDate not supplied

The unkindest cut of all: are international medical school graduates subjected to discrimination by general surgery residency programs?

PURPOSE: International medical school graduates (IMGs) have been part of the United States residency applicant pool for several years. There has been increasing discussion of an overproduction of doctors in the United States, and mention of limiting IMG quotas. The purpose of this study was to find out if measurable discrimination existed real or perceived, against IMGs. METHODS: A survey was performed to assess whether program directors of surgery residencies perceive the performance, dedication, and abilities of IMGs as being equal to United States medical school graduates (USMGs), and whether program directors believe that a preference toward USMGs exists. Surveys with 30 tailored questions were mailed to all members of the Association of Program Directors in Surgery. One hundred twenty-five surveys were returned out of 283 mailed, and 112 were included in the data analysis. Besides those relating to demographics, questions on the survey included two series of queries. One set was designed to assess whether the respondent reported that IMGs possessed similar skills and abilities as USMGs, whereas the other addressed whether respondents perceived a tendency in their programs to focus recruitment toward USMGs. Still others were inserted to confirm results of these series, and to assess whether program directors perceived discrimination toward IMGs in general. RESULTS: Survey results indicate the perception that IMGs are similar in skill and ability to USMGs, regardless of program size. However, a perception existed among program directors that USMGs were favored in the recruitment process, with more than 70% of respondents indicating that they believed IMGs were discriminated against. Furthermore, nearly 20% reported that they had been pressured to rank a less-qualified USMG higher than a more qualified IMG, and 22% reported that they had ranked a USMG higher than an IMG to avoid a reduced compliment of USMGs. CONCLUSIONS: There is a significant belief and perception that IMGs are indeed discriminated against, despite program directors seeing no clear differences in surgical skills between IMGs and USMGs.

Journal Article↗