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J Sheppard

Publications and source records attributed to J Sheppard.

9 recordsLinked to original sources
PubMed1992

The clinical task.

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Community Health Services↗
PubMed1978

Complement activating factor(s) of Trypanosoma lewisi: some physiochemical characteristics of the active components.

Of the complement activating factors present in Trypanosoma lewisi, the major component, a carbohydrate containing substance was further investigated. This component was found to have a lag time of complete activation of 2 CH50 units of bovine complement of approximately 15 minutes while 1% trypsin (a known activator of complement, used as a control system) was capable of instant consumption of a similar quantity of complement. In addition, the complement activating factor of trypanosomes was observed to be stable at 100 degrees C for 15 minutes and over a pH range of 3.0 to 11.0. Thin layer chromatography studies suggested that at least part of the active component contained lipid, perhaps indicating that it may be glycolipid in nature.

Animals↗
PubMed1978

Experimental bovine trypanosomiasis. Changes in the catabolism of serum immunoglobulins and complement components in infected cattle.

The turnover of serum proteins of calves experimentally infected with Trypanosoma congolense was compared to that of normal uninfected cattle. All proteins examined had much increased catabolic rates in infected animals. In normal animals the average half-lives in days for each protein were: IgG1 17.4, IgG2 22.4, IgM 4.8, IgA 3.4, IgE 1.9, C1 5.6 and C3 2.9. In trypanosome infected cattle the average half-lives were IgG1 1.9, IgG2 1.7, IgM 0.9, IgA 1.2, IgE 0.9, C1 1.2 and C3 1.1 days.

Animals↗
PubMed1978

Experimental bovine trypanosomiasis. Changes in serum immunoglobulins, complement and complement components in infected animals.

In three calves experimentally infected with Trypanosoma congolense the amounts of IgG1 and IgG2 were little changed and similar to those of normal animals. IgM increased in amount early in the infection and the amount of the increase appeared related to the parasite burden. The amounts of IgA and IgE were both much decreased and this also appeared related to the numbers of parasites in the blood. There was a decrease in the amounts of total haemolytic complement and complement components C1, C1q and C3 in the infected calves. Furthermore the amounts of properdin fluctuated with the cyclical changes in numbers of T. congolense parasites in the individual calves. No significant change in the amount of C8 was observed. It is considered that activation of both the alternative and the classical complement pathways occurs in trypanosome infected animals but that neither pathway goes to its terminal stages.

Animals↗
PubMed1977

Activation of complement by trypanosomes.

Factors exhibiting anti-complementary activity released from trypanosomes after incubation at 20 degrees C were described. The active material was shown to consume the first component of bovine complement. While the anti-complementary factor(s) from T. lewisi could activate bovine, human and guinea pig complement, the factor(s) from T. congolense was observed to activate bovine complement, but not guinea pig and only slightly human complement. The roles of complement activating factor(s) of trypanosomes in the pathology of the disease are discussed.

Animals↗