A low molecular weight immunosuppressive factor produced by Onchocerca gibsoni

An immunosuppressive factor(s) which is heat stable, and dialysable, with a molecular weight less than 10,000 molecular weight, and is not species specific, has been shown to be produced during the in vitro culture of Onchocerca gibsoni microfilariae. The factor(s) is capable of abolishing lymphocyte mitogenesis induced by Con A in bovine lymphocytes and PHA in human lymphocytes. The factor(s) may play a role in establishing the microfilariae in the tissues of the host by depressing cell mediated immune reactions during invasion.     

The influence of some packaging and post-harvest treatments on the incidence of Ripe Spot in ‘Golden Delicious’ and ‘Crofton’ apples

A trial was designed to study different methods of high humidity storage for bushel packs of apples. The methods studied were polyethylene (= polythene) bag liners (= polyliners), perforated polythene lined, together with the effectiveness of thiabendazole (T.B.Z.) in controlling Ripe Spot (Gloeosporium sp.) in polythene lined packs. A further treatment incorporated a wax coating on the apples instead of a polythene liner.A post-harvest dip of T.B.Z. followed by storage in polylined packs ensured that ‘Golden Delicious’ and ‘Crofton’ apples had minimal weight losses and low levels of Ripe Spot. Storage in polythene liner or perforated polythene liner without T.B.Z. resulted in high levels of Ripe Spot in both cultivars. Although waxing prior to storage did not increase the incidence of Ripe Spot over that in control fruit, it did not reduce weight loss to the low levels of the polylined treatments.     

The relative effects of rootstocks and calcium sprays on the appearance of internal breakdown and superficial scald of ‘Red Delicious’ apples during storage

The 2-year investigation involved storing fruit samples from each tree in a trial of 8 rootstocks with the locally selected ‘Lalla Red Delicious’ to see how the storage characteristics were modified by rootstock and/or calcium sprays.The 6 spray applications of calcium made a significant reduction in the incidence of internal breakdown in both years, although the magnitude of the response varied from rootstock to rootstock in 1976. There were no significant rootstock effects in 1975, and in 1976 they were eliminated where calcium sprays were used. In the absence of calcium sprays in 1976, apples from ‘M. 16’ produced significantly more internal breakdown than those from any of the other stocks, with ‘MM. 107’ producing the second highest level. At the other end of the scale, apples from ‘MM. 110’ had the lowest incidence, closely followed by ‘M. 1.’ The remaining 4 stocks (‘11 immune’, ‘M.13’, ‘M.25’ and ‘Seedling’) gave intermediate readings and were not significantly different from each other.The calcium spray treatments also significantly reduced the incidence of superficial scald with all rootstocks. The main rootstock effect observed was that apples from ‘MM. 110’ and ‘M. 1’ had significantly less scald than from 5 of the other 6 rootstocks.     

The present status of canine parvovirosis

Results from studies performed by the authors and by other workers, have greatly increased the knowledge of canine parvovirus.

The authors review the situation with particular reference to virology, epidemiology, pathogenesis, pathology and immunoprophylaxis.