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Biomedical subjects

D R Russell

Publications and source records attributed to D R Russell.

13 recordsLinked to original sources
PubMed2004

Delphi based consensus study into planning for chemical incidents.

OBJECTIVE: To achieve consensus in all phases of chemical incident planning and response. DESIGN: A three round Delphi study was conducted using a panel of 39 experts from specialties involved in the management of chemical incidents. Areas that did not reach consensus in the Delphi study were presented as synopsis statements for discussion in four syndicate groups at a conference hosted by the Department of Health Emergency Planning Co-ordination Unit. RESULTS: A total of 183 of 322 statements had reached consensus upon completion of the Delphi study. This represented 56.8% of the total number of statements. Of these, 148 reached consensus at >94% and 35 reached consensus at >89%. The results of the process are presented as a series of synopsis consensus statements that cover all phases of chemical incident planning and response. CONCLUSIONS: The use of a Delphi study and subsequent syndicate group discussions achieved consensus in aspects of all phases of chemical incident planning and response that can be translated into practical guidance for use at regional prehospital and hospital level. Additionally, areas of non-consensus have been identified where further work is required.

Accidents, Occupational↗
PubMed2004

Planning for chemical incidents by implementing a Delphi based consensus study.

This paper provides a practical approach to the difficulties surrounding planning for chemical incidents, based upon the results of a Delphi based consensus study. It is intended to offer advice, which can be implemented at regional and local prehospital and hospital level. The phases of the response that are covered include preparation, management of the incident, delivery of medical support during the incident, and recovery and support after the incident.

Accidents, Occupational↗
PubMed1998

A humanized monoclonal antibody produced in transgenic plants for immunoprotection of the vagina against genital herpes.

The ability to produce monoclonal antibodies (Mabs) in plants offers the opportunity for the development of an inexpensive method of mucosal immunoprotection against sexually transmitted diseases. To investigate the suitability of plant-expressed Mabs for vaginal preventive applications, we compared a humanized anti-herpes simplex virus 2 (HSV-2) Mab expressed in mammalian cell culture with the same antibody expressed in soybean. We found these Mabs to be similar in their stability in human semen and cervical mucus over 24 h, their ability to diffuse in human cervical mucus, and their efficacy for prevention of vaginal HSV-2 infection in the mouse.

Animals↗
PubMed1998

Soybeans transformed with a fungal phytase gene improve phosphorus availability for broilers.

Male broilers (n = 416) were used to compare the efficacy of providing dietary phytase either as a commercial supplement or as a recombinant protein in transformed soybean. From 7 to 21 d of age, broilers were fed a basal diet containing 0.20% nonphytate P (nP) with additional supplementation by fungal phytase as Natuphos or as raw transformed soybeans expressing recombinant phytase at 400, 800, or 1,200 U/kg. For comparison, broilers were also fed the basal diet containing 0.08, 0.16, or 0.24 added nP. The basal diet was fed as the negative control. Diets were consumed ad libitum as a mash. All excreta were collected from each pen from 18 through 20 d of age, and the birds were killed at 21 d of age. Supplementing the basal diet with nP linearly increased body weight gain, feed efficiency, feed intake, toe ash weight and percentage, and tibia shear force and energy. Phosphorus digestibility decreased linearly as nP level increased, but P excretion increased. Dietary phytase linearly increased growth rate, feed intake, toe ash weight and percentage, tibia shear force and energy, and P digestibility, whereas excretion was decreased. Except for P digestibility, there was no difference in efficacy of responses for performance, bone mineralization, and P excretion between the two sources of phytase. It appears from this study that phytase can improve growth performance of broilers fed low nP diets when provided either as a commercial supplement or in the form of transformed seeds.

6-Phytase↗
PubMed1996

Are physiological effects of sleep deprivation in the rat mediated by bacterial invasion?

Recent reports have indicated that rats subjected to total sleep deprivation (TSD) by the disk-over-water method and sacrificed when death appeared imminent showed aerobic bacteria in their blood. Yoked control rats did not. Extrapolating from these results, it has been suggested that the late body temperature declines and eventual deaths of TSD rats are caused by septicemia, and that other, earlier-appearing effects of TSD-including weight loss, increased energy expenditure, and regulation of temperature at a higher level-might be mediated by impaired host defenses against bacterial invasion. Three measures of aerobic bacterial invasion were used to evaluate these hypotheses: bacteremia, bacterial colonization in major organs of filtration (liver, kidney, and mesenteric lymph nodes), and adherence of bacteria to the cecal wall. Experiment 1 showed nonsignificant trends toward more bacterial invasion in 4-day TSD rats compared to yoked control rats and no relationship between the bacterial indicators and the early TSD effects. Experiment 2 showed that the elimination of aerobic bacterial infection by antibiotic treatment did not prevent the early TSD effects in 4-day TSD rats. Experiment 3 showed that the elimination of aerobic bacterial invasion in TSD rats did not eliminate the late temperature decline or the progression towards death. The results showed no significant evidence of aerobic bacterial invasion early in TSD and no indication that the major effects of TSD were dependent upon aerobic bacterial invasion.

Animals↗
PubMed1995

Mutational analysis of a putative NTP-binding domain in the replication-associated protein (AC1) of bean golden mosaic geminivirus.

Bean golden mosaic virus (BGMV) is a whitefly-transmitted, ssDNA geminivirus with a bipartite genome. AC1 is the only ORF required for geminiviral replication. A putative NTP-binding motif, EGX4GKTX32DD, was present in the derived amino acid sequence of the replication-associated protein from the AC1 ORF for 13 geminiviruses including BGMV-GA (Guatemalan isolate, amino acids 221-263). We analyzed the phenotypes of mutations within this domain using a rapid and sensitive PCR-based assay for geminiviral replication developed for these studies. Replication in tobacco cells (NT-1 suspension cells) and infection of beans were abolished when codons were changed from K228 to H or D262 to R within the putative NTP-binding site. A temperature-sensitive replication phenotype was conferred by changing E221 to R within the putative NTP-binding domain. Replication was unaffected by changing a nonconserved codon near the putative NTP-binding domain from 1190 to R. Our results demonstrate that the putative NTP-binding domain is required for geminiviral replication. The role of NTP hydrolysis and the possible value of these mutants in a trans-dominant interference scheme for virus-derived resistance are discussed.

Amino Acid Sequence↗
PubMed1991

Use of the asymmetric polymerase chain reaction and DNA sequencing to determine genetic variability of bean golden mosaic geminivirus in the Dominican Republic.

A combination of the polymerase chain reaction (PCR), asymmetric PCR (A-PCR) and DNA sequencing was used to determine the nucleotide sequence of a hypervariable region of the bipartite genome of bean golden mosaic geminivirus (BGMV). This region, which was part of the intergenic region of the DNA-B component, was amplified using primers designed from the nucleotide sequence of a DNA-B component clone (pDRB1) of an isolate of BGMV from the Dominican Republic (BGMV-DR). pDRB1 is infectious on beans when coinoculated with the DNA-A component of BGMV-DR (pDRA1), and typical bean golden mosaic symptoms are observed on infected plants. Bean leaf tissue infected with BGMV was collected at five separate field locations in the Dominican Republic and the hypervariable region was amplified by PCR, ssDNA was produced using A-PCR, and partial nucleotide sequences were determined. The sequences of the hypervariable region from the field-collected samples ranged from 95% (one sample) to 98% (four samples) identical to the sequence of pDRB1. This contrasts with sequence identities of 86, 75 and 46% between the pDRB1 hypervariable region and the hypervariable regions of BGMV isolates from Guatemala, Puerto Rico and Brazil respectively, and 42% with bean dwarf mosaic geminivirus. These results indicate that Dominican Republic isolates of BGMV are very similar and should be considered isolates of the same virus (BGMV-DR), and that the infectious clones of BGMV-DR are representative of BGMV isolates in the Dominican Republic. The procedures described for DNA extraction from leaf tissue and for production of high quality ssDNA using PCR and A-PCR are rapid and efficient and could be applied to studies of variability and epidemiology of other viruses.

Base Sequence↗
PubMed1985

In vitro characterization of hybrid promoters and altered tryptophan operon promoters.

This study examines the in vitro interaction of hybrid and altered Escherichia coli promoters and other promoters with purified E. coli RNA polymerase. Three parameters of polymerase activity were examined: the time for open complex formation; the temperature of transitions; and the time required for productive initiation. The results indicate the rate of in vitro binding as measured by the filter binding technique does not completely correlate with the in vivo activities among these diverse promoters. Transition temperatures ranged from 13 to 27 degrees C with the lowest transition temperatures associated with the relatively weak in vivo beta-lactamase and anti-tet promoters. The productive initiation studies showed a dependence on labeled nucleoside triphosphate concentration when that nucleotide was present early and frequently in the transcript. Promoters containing the -10 region of the lac promoter had slow productive initiation rates while trp -10 promoter derivatives were generally very fast. In the promoters studied here, a trend was noted between the binding rate and transition temperature studies in that the promoters with the lower transition temperatures tended to bind more rapidly.

Cytidine Triphosphate↗
PubMed1984

Role of DNA regions flanking the tryptophan promoter of Escherichia coli. I. Insertion of synthetic oligonucleotides.

To examine the effect of altering the nucleotide sequence near the promoter on its activity, pKO-1 vector derivatives have been constructed which allow insertion of DNA fragments at specified sites upstream or downstream from the trp promoter. Oligonucleotides that might be expected to alter the melting properties, or have a tendency to form a distinctive nonstandard structure were introduced. These oligonucleotides had the repeating dinucleotide sequences GC, AT or AG. Sequence analysis of the inserts and studies of the relative galactokinase expression from the altered plasmids indicated that changes upstream from the trp promoter at -39 or beyond had little effect on trp promoter activity, whereas changes at +2 or farther downstream produced up to two-fold increases in gene expression, as compared to the control plasmid.

Base Sequence↗
PubMed1981

Characterization of the beta-lactamase promoter of pBR322.

The beta-lactamase promoter of pBR322, derived from Tn3, has been characterized using several techniques. The transcription initiation site is located 35 base pairs from the translation initiation codon of beta-lactamase. The mRNA produced in vitro has a 5' pppGpA terminus. RNA polymerase bound at this start site protects a region from about -50 to +20 from DNase I cleavage using the footprinting technique. RNA polymerase binds rapidly to the beta-lactamase promoter. The half-time of association is less than one-half minute. The half-time of dissociation is approximately 6 hr. A study of the binding of RNA polymerase at different temperatures showed a large change between 11 degrees and 15 degrees C. Comparison of these parameters with those reported for other promoters is discussed.

Base Sequence↗