Biomedical subjects

V H Smith

Publications and source records attributed to V H Smith.

At least 19 recordsLinked to original sources

PubMed1998

Implications of resource-ratio theory for oral microbial ecology.

The ability to compete for the limited nutrients available to the microorganisms of dental plaque is a strong ecological determinant of the structure of the subgingival ecosystem. This paper introduces a new concept from the field of ecology, resource-ratio theory, and applies it to the dynamics of microbial dental plaque with emphasis on the putative periodontal pathogens. Resource-ratio theory is a mechanistic theory of resource competition that utilizes pairs of growth-limiting nutrients in a stoichiometric fashion to predict zones of competitive dominance, exclusion, and coexistence for organisms competing for these resources. Once these resource pairs are identified for plaque organisms, resource-ratio theory may provide predictions of changes in the microbial community structure of plaque based on directional changes in their resource supply ratios.

Bacteria↗

PubMed1990

Visual evoked potential monitoring of optic nerve function during surgery.

A study was made with intra-operative flash--visual evoked potentials (VEP) monitored using a fibre-optic/contact lens photo stimulator in 57 patients undergoing intra-orbital surgical procedures with potential risk to the optic nerve. The VEPs recorded under enflurane and nitrous oxide anaesthesia did not differ significantly in latency or amplitude from the pre-operative recordings. Transient abolition of the VEP was seen under many circumstances and did not correlate with the outcome of surgery, but absence of a previously normal VEP for more than four minutes during surgical manipulation within the orbit did show a correlation with post operative impairment of vision. The technique provides early warning to the surgeon of threats to the integrity of the optic nerve.

Adolescent↗

PubMed1988

Review of diclofenac and evaluation of its place in therapy as a nonsteroidal antiinflammatory agent.

Diclofenac sodium is a nonsteroidal antiinflammatory drug (NSAID) that has been used in 120 countries since its introduction in Japan in 1974. It is currently the eighth largest-selling drug and the most frequently used NSAID in the world. Diclofenac, a phenylacetic acid derivative, is a potent inhibitor of cyclooxygenase enzyme activity, and may also interact with the lipoxygenase enzyme pathway, and with the release and reuptake of arachidonic acid. Diclofenac is almost completely absorbed, highly protein-bound, penetrates well into synovial fluid, and is extensively metabolized. Comparative studies have shown that diclofenac is at least equivalent in efficacy to aspirin and other NSAID when used for the treatment of rheumatic diseases such as rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis. Diclofenac also possesses potent analgesic properties. Clinical trials suggest that diclofenac has a favorable side-effect profile, excellent patient tolerability, and a lower patient dropout rate when compared with aspirin and other NSAID.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1987

A contact lens photostimulator for surgical monitoring.

A haptic contact lens stimulator has been developed to allow monitoring of the visual evoked potential to flash stimulation during orbital surgery. The contact lens stimulator is fitted with a small plastic prism into which a fibre-optic cable is inserted at right angles to the axis of the contact lens. This allows both the stimulator and the fibre-optic to be permanently in place throughout orbital surgery without interfering with the surgeon's vision or dexterity. Using this technique continuous evoked potentials can be obtained allowing immediate feedback to the surgeon of any condition threatening the integrity of the optic nerve. The technique has now been used on over 20 eyes and is commercially available.

Contact Lenses↗

PubMed1986

Hyaluronidase and sodium hyaluronate in cataract surgery.

The use of sodium hyaluronate in cataract surgery and intraocular lens implantation is often followed by a postoperative rise of intraocular pressure. A trial is described in which 10 patients underwent bilateral cataract extraction and Binkhorst intraocular lens implantation with the use of sodium hyaluronate. The enzyme hyaluronidase was instilled into the anterior chamber of the right eye only, to aid removal of sodium hyaluronate, and resulted in a statistically significant lowering of postoperative intraocular pressure in right eyes compared with left. Other uses of the enzyme are discussed.

Aged↗

PubMed1982

Orbital tumours.

Explore the source record for details and available documents.

Adult↗

PubMed1980

Early effects of inhaled Ca-DTPA on the rat lung.

Inhalation of calcium trisodium diethylenetriaminepentaacetate (Ca-DTPA) increases the removal of plutonium and other transuranics from the body. Data are required to determine possible biological effects from inhaled DTPA. Female rats were given a single or 12 daily, 2-4 h, inhalation exposures to aerosols of 10, 20 and 40% Ca-DTPA and the lungs were examined at 21 and 42 days following the last exposure. No pulmonary pathology was found from the single inhalation treatment with Ca-DTPA while only a slight, peripheral, histiocytosis was observed in the lungs of multiple-treated rats. There was no significant effect of DTPA treatments on body weight, lung weight, hematology or serum chemistry values.

Animals↗

PubMed1979