Biomedical subjects

F Yates

Publications and source records attributed to F Yates.

7 recordsLinked to original sources

PubMed1987

The effect of modulating the synthesis of arachidonic acid cascade products on HSV lesion recurrence.

Induction of HSV lesion recurrence may be achieved by a variety of stimuli. Trauma of almost any kind (physical, chemical, electromagnetic and thermal) to the healed primary lesion site has been successful for induction of recurrence. In common with each of these mechanisms is the release of inflammatory mediators (arachidonic acid (AA), complement, kinins, etc.) following trauma. Because blockade of the AA cascade with steroids has been noted to abort HSV skin lesions, and because steroids have numerous side effects making them a poor therapeutic choice in ocular lesions, we decided to test several relatively different types of AA cascade inhibitory drugs in mouse ear HSV recurrence models. In this series of experiments, it was found that topical steroids gave the greatest initial decrease in lesion number (80% fewer than control on day 3 post recurrence induction (PRI), while meclofenamate resulted in the greatest reduction of lesions by day 5 PRI (85% fewer lesions than control and 60% fewer than the steroid treated group). The NDGA treated group exhibited the least reduction in recurrence severity (27% fewer lesions than control on day 5 PRI and 200% more lesions than the steroid group. Chlorpromazine (thorazine) acted roughly equivalent to the steroid treated group by day 5 PRI (70% fewer lesions than the untreated control group). Relative efficacy in lesion reduction between groups by day 5 PRI is: meclofenamate greater than steroid = chlorpromazine greater than NDGA greater than control. Meclofenamate, steroid and chlorpromazine significantly reduced lesions (p less than .05) when compared with the saline treated control mice. NDGA did not significantly reduce lesions by day 5 PRI.

Animals↗

PubMed1987

Herpes simplex virus: recurrent and nonrecurrent strains.

A study of three Herpes Simplex strains with different frequencies of recurrent disease was done using the New Zealand white rabbit eye model. Each of the three strains, the McKrae strain (high frequency), the E-43 strain (low, frequency), and the CGA-3 (no recurrence) grew well in the rabbit corneal epithelium and produced overt recognizable disease for up to 5 days post-infection, thus minimizing differences in virus reactivation due to a lack of or insufficient ganglionic colonization. Asymptomatic shedding and spontaneous recurrences, as well as iontophoretically induced recurrences, were seen in the E-43 and McKrae strains, but not in the CGA-3-infected animals. The virus strain's optimum temperature was an important aspect of its reactivation process, as shown by the failure of the nonrecurrent CGA-3 to replicate at the host's core temperature (39 degrees C). The fact that these explants yielded infectious virus at 33 degrees C and not at 39 degrees C confirmed that the CGA-3 had colonized the ganglia, and its lack of recurrences or shedding suggests a temperature-dependency relationship. Our observations were further supported by the preferential growth at 39 degrees C of fresh clinical isolates obtained from HSV encephalitis and herpes labialis. Isolates from animals infected with the heterogeneous McKrae were classified as shedders (isolated in the absence of disease) and recurrent (isolated from a recurrent lesion). Both shedders and recurrent isolates were of a homologous nature and retained their phenotype when tested. From this study, we theorize that reactivation and disease may have different regulatory mechanisms. The type of recurrent disease (lesions, asymptomatic shedding, or none) is virus-dependent and frequency of disease may be regulated by host functions.

Animals↗

PubMed1983