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Biomedical subjects

R B Davey

Publications and source records attributed to R B Davey.

At least 73 records · Page 4Linked to original sources
PubMed1988

Appendicitis in the first three years of life.

Appendicitis is the first 3 years of life is uncommon and most cases are perforated at laparotomy. Case records at the Adelaide Children's Hospital were reviewed over a 12-year period. The findings were that acute appendicitis in this age group is commonly associated with respiratory symptoms and diarrhoea, the appendix was gangrenous or perforated in 92% of cases, and there was a significant delay in diagnosis. It is concluded that full evaluation of any child of this age with fever, vomiting, abdominal pain and tenderness is mandatory, and should include rectal examination, abdominal radiographs, differential white cell count and urinary examination. Examination under sedation may be necessary.

Acute Disease↗
PubMed1988

Cage design for the confinement of deer and goats infested with ectoparasites.

The design for a cage for the confinement of white-tailed deer (Odocoileus virginianus) and goats (Capra sp.) for use in ectoparasite studies is presented. The cage was successfully used for the infestation of these hosts with Boophilus annulatus and may be useful for host/parasite studies using similar hosts and other ectoparasites. The cage will accommodate mature hosts with adequate space for normal grooming activity. A detailed description of materials and methods for the assembly of the cage is provided in the text.

Animals↗
PubMed1987

The Spencer Op-Site Applicator, a new technique for treating the burned hand.

A technique to apply Op-Site Incise Drape to the burned hand is described using the Spencer Op-Site Applicator. The technique allows for the use of a transparent, flexible, semi-permeable plastic glove in the management of the burned hand in all age-groups. This minimizes excoriation of normal tissue but allows full flexibility of the hand with good healing.

Bandages↗
PubMed1987

Current materials and techniques used in a burn scar management programme.

A range of materials is now available for use in a burn scar management programme. The use of these materials is detailed and suggestions are made based upon the experience gained from close clinical observation of children treated over a 7-year period at the Adelaide Children's Hospital Burn Clinic. Lightweight pressure garments are still needed to keep these various media in contact but are not included in the discussion.

Bandages↗
PubMed1986

Influence of the virulence plasmid and the Congo red reaction on the antimicrobial susceptibility of Yersinia species.

Seventeen strains of Yersinia enterocolitica and related species were examined for their susceptibility to a variety of antimicrobial agents. Twelve of the strains were clinical isolates which carried a virulence plasmid; five were food isolates which lacked plasmids. When grown on agar containing Congo red or haemin, each strain yielded pigmented (CR+) and non-pigmented (CR-) variants. CR+ bacteria of clinical origin were virulent, whereas CR+ food isolates and all CR- bacteria were avirulent. The susceptibility of CR+ and CR- bacteria to the following agents was compared: ampicillin, chloramphenicol, latamoxef, nalidixic acid, novobiocin, polymyxin B, rifampicin, streptomycin, tetracycline and tobramycin. The results showed that bacteria which bound Congo red were more susceptible to each drug examined than their CR- counterparts. This relationship held regardless of whether the CR+ bacteria possessed a virulence plasmid or not. The findings suggest that binding of antimicrobial agents by yersiniae may parallel binding of haemin and Congo red.

Anti-Bacterial Agents↗
PubMed1986

Genetic similarity and variability between natural populations and laboratory colonies of North American Boophilus (Acari: Ixodidae).

Four natural populations and 4 laboratory colonies of Boophilus microplus (Canestrini) and a laboratory colony of Boophilus annulatus (Say) were subjected to electrophoretic analysis to determine levels of genetic similarity and genetic variability. Populations of B. microplus exhibited high genetic similarity (I = 0.984 +/- 0.012) indicating that all populations share a relatively undifferentiated gene pool. Host vagility is proposed as an important mechanism promoting gene flow in ectoparasites. Levels of genetic variability for B. microplus (h = 0.092 +/- 0.008; P = 0.330 +/- 0.050) were within levels reported for other arthropods. The average genetic identity of 0.716 +/- 0.013 between B. microplus and B. annulatus is of a level characteristic of sibling species. Diagnostic isozymes between laboratory colonies will facilitate identification of these morphologically similar species.

Alleles↗
PubMed1985

In vitro assessment of virulence in Yersinia enterocolitica and related species.

We have examined 136 isolates of Yersinia species, comprising 112 strains of Yersinia enterocolitica, 12 of Y. frederiksenii, 8 of Y. intermedia, and 5 of Y. kristensenii, for the presence of 40- to 50-megadalton virulence-associated plasmids and expression of the following plasmid-associated characteristics: Congo red pigmentation (CR), calcium dependence, autoagglutination, hydrophobicity, resistance to normal human serum, and pathogenicity in mice. All 136 strains yielded both pigmented (CR+) and nonpigmented (CR-) variants. Only CR+ variants, however, were virulent for iron-overloaded, desferrioxamine B-treated mice (R. M. Robins-Browne and J. K. Prpic, Infect. Immun. 47:744-779, 1985). Although the in vitro virulence-associated characteristics generally occurred together, each one could be expressed independently. Strains of Y. frederiksenii, Y. intermedia, and Y. kristensenii also expressed individual virulence-associated properties. Of 53 Y. enterocolitica strains which were virulent for iron-overloaded, desferrioxamine-treated mice, all but one expressed every virulence-associated characteristic. Several strains which were avirulent for mice, however, demonstrated these characteristics in various combinations. Because many Yersinia strains, particularly environmental isolates, carried plasmids of 40 to 50 megadaltons, detection of plasmids provided little information about bacterial pathogenicity unless virulence-associated properties were also sought. The best in vitro predictor of virulence was autoagglutination, followed by calcium dependence. Because only CR+ variants expressed virulence-associated determinants, Congo red pigmentation is useful for selecting potentially virulent strains.

Agglutination Tests↗
PubMed1984

The use of mini-Gal plasmids for rapid incompatibility grouping of conjugative R plasmids.

The galactose operon of Escherichia coli K-12 has been used as a phenotypic marker for miniplasmids derived in vitro from R plasmids representing six incompatibility groups. This has enabled the development of a rapid incompatibility typing scheme in which the miniplasmids are used as incompatibility exemplars, their presence in strains being monitored on galactose fermentation indicator media.

Bacteriological Techniques↗
PubMed1984

Control of Boophilus ticks on heifers with two pyrethroids applied as sprays.

The pyrethroid permethrin (25% cis to 75% trans) was sprayed on Hereford heifers infested with all parasitic stages of Boophilus microplus (Canestrini) at 0.05% and 0.1% active ingredient. At 0.05%, control was 66.7%; whereas at 0.1%, control was 93.3%. Replete females were collected daily for 28 days after treatment at both concentrations, indicating that at least some ticks treated as larvae or nymphs were able to reach repletion. The pyrethroid fenvalerate was sprayed on Hereford heifers infested with all parasitic stages of B microplus or B annulatus (Say) at 0.025% and 0.05% active ingredient. Fenvalerate was as effective as permethrin at a lower concentration. At 0.025%, control was 89.2% and 86.6% and at 0.05% was 92.5% and 90.1% for B microplus and B annulatus , respectively. Both these pyrethroids could provide adequate reduction in programs in which control is the aim; however, in an eradication program, both acaricides failed to provide the necessary reduction to achieve complete elimination.

Animals↗
PubMed1983

Silicone gel: a new treatment for burn scars and contractures.

A new method of treatment for burn scar management is outlined using silicone gel sheets (Spenco Corporation MD-3071). The method has been applied to 42 patients with burns of varying degree and maturity. The results have been successful in all cases. The mode of action of the gel is unknown, but it does not rely on pressure. The method can easily be tailored to the individual needs of the scar and the patient. Individual initiative and a flexible approach to its use are advocated.

Adolescent↗
PubMed1983

Differentiation between virulent and avirulent Yersinia enterocolitica isolates by using Congo red agar.

Cultivation of clinical isolates of Yersinia enterocolitica of diverse geographical origin on a medium containing 5 micrograms of Congo red per ml disclosed two colony types. These were designated CR+ and CR- according to their ability to bind Congo red. CR+ strains bore plasmids of between 40 and 50 megadaltons and were positive in several tests of Y. enterocolitica virulence, including autoagglutination, reduced growth on magnesium oxalate agar, resistance to the bactericidal effect of serum, and lethality for iron-overloaded mice. CR- strains were plasmidless and were negative in all these assays. The Congo red reaction provides a simple and efficient means of screening Y. enterocolitica for virulence and is the best available method for identifying individual plasmid-bearing colonies.

Agglutination Tests↗