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Biomedical subjects

N Thantrey

Publications and source records attributed to N Thantrey.

6 recordsLinked to original sources

Prick testing for allergens standardized by using a precision needle.

A new standardized precision needle which virtually removes operator variation from skin prick testing with allergens is described. The instrument is simple and robust, and the results of its use are demonstrated. The most important finding was that the use of strong pollen extracts produced very inconsistent and irregular weals, but when suitably diluted, or used on mildly sensitive skins, reproducibility of the response was excellent and it is therefore ideal for titration of skin sensitivity and biological assessment of the potency of allergens. The standard needle was also compared with two other methods of skin prick testing. Results were similar but the standard needle showed the least variation.

Humans↗

Species specific grass pollen sensitivity: diagnosis and treatment with single grass species Allpyral vaccines.

Skin test titrations and nasal provocation tests in sixty patients with hay fever showed specific reactions to extracts of individual grass species. There was, however, no correlation between skin and nasal sensitivity. Repeat testing after treatment with Allpyral vaccines consisting of only the grass species to which the nasal reaction was most severe, or only one of several pollens to which reactions were equally severe, showed marked diminution of skin and nasal sensitivity not only to the single pollen used for immuno-therapy but to all five common pollens used in the Allpyral grass mix. Clinical results seemed much improved as compared with results in the same year for Allpyral five grass mix vaccines, especially in the case of patients treated with Timothy, rye, or cocksfoot. It was concluded that these three grassees were to be preferred for treatment in England, and that these grasses contain common allergens.

Dose-Response Relationship, Immunologic↗

Rapid extraction of grass pollen allergens and separation of their active fractions.

The immediate effects of nasal provocation tests with dry grass pollen, correlated with recent botanical evidence of almost instant release of allergens from the pollen wall, suggested that prolonged extraction of pollens was unnecessary and perhaps undesirable. It has now been shown that all the active allergens from undefatted dry grass pollens of the 12 major British species are extracted completely in 15 min. Gel chromatography of such rapid extracts has shown clear-cut separation of active from inactive material, as confirmed by skin and nasal provocation testing. It is probable that active fractions thus obtained contain the only pollen allergens of importance to clinical allergy. Further purification may produce specific allergens useful for the accurate standardisation of vaccines.

Allergens↗

Specific B lymphocyte suppression by infectious bursal agent (Gumboro disease virus) in chickens.

Chickens infected experimentally with infectious bursal agent (IBA) during embryonation or early after hatching show a severe depression of bursa-dependent lymphoid components, and associated immune functions. Data presented here and elsewhere show that the degree of B cell suppression correlates with the time of infection. This would be compatible with a virus-induced block in B lymphocyte differentiation. Accordingly, the virus may be cytopathic for early (bursal) but not late (circulating) B lymphocytes or, more likely, the virus inactivates those non-lymphoid bursal cells mediating lymphocyte differentiation.

Animals↗

The bursa dependence of chicken thymus-derived lymphocyte surface immunoglobulin.

Thirty-three plus or minus 5 per cent of chicken blood lymphocytes were positively labelled by radioiodinated rabbit anti-chicken light chain antibody within 7 days of exposure of autoradiographs. After thymectomy, 93 plus or minus 1 per cent of lymphocytes were positive: conversely, following bursectomy only 5 plus or minus 3 per cent of cells showed positive labelling and then at a very low level. Hence, under these conditions of short-term exposure autoradiography, only B cells carried readily demonstrable immunoglobulin. If the sensitivity of the technique was increased by long-term exposure of the autoradiographs, immunoglobulin was demonstrable on all blood lymphocytes, including the T cells. In addition, 39 plus or minus 6 per cent of thymocytes were shown to carry immunoglobulin by the more sensitive technique. In both cases, however, this T-lymphocyte surface immunoglobulin was reduced, and in some cases absent, after bursectomy. At no stage, with either technique, did the grain count on the erythrocytes reach the control level of lymphocytes treated with 125I-labelled anti-keyhole limpet haemocyanin antibody. It seems likely that T-cell immunoglobulin is not an endogenously synthesized product but is acquired indirectly from the B lymphocytes.

Animals↗