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Biomedical subjects

C R Jenkin

Publications and source records attributed to C R Jenkin.

At least 37 records · Page 2Linked to original sources
PubMed1979

Alternative pathway activation of complement by a murine parasitic nematode (Nematospiroides dubius).

The cuticular surface of the infectious third-stage larvae of Nematospiroides dubius activates complement via the alternative pathway. Sensitisation of larvae with complement or with antibodies from the serum of immune mice (resistant to reinfection) promoted the adherence of mouse peritoneal exudate cells to the larval cuticle during incubation in vitro. The infectivity of larvae sensitized with antibody or complement was significantly reduced after incubation with cells from immune mice.

Animals↗
PubMed1979

The development of resistance in different inbred strains of mice to infection with Nematospiroides dubius.

Infection by the intestinal nematode parasite Nematospiroides dubius was studied in seven different inbred mouse strains. Although there was some minor variation in the susceptibility of the different strains to a primary infection there were marked differences in their ability to develop resistance to infection following repeated exposure to infective larvae. The strains of mice which developed the best resistance also expelled adult worms arising from the previous infections. The adult worms resulting from a primary infection were slowly eliminated in two inbred strains studied whereas no loss occurred from outbred LACA mice. Although males and females of two strains, C3H/HeJ and CBA/H were equally susceptible to a primary infection, the females developed better resistance than the male mice following two oral administrations of third stage larvae. Infected mice of every strain and both sexes contained high levels of IgG1 in the serum.

Animals↗
PubMed1978

Evidence implicating the mononuclear phagocytic system of the rat in immunity to infections with Trypanosoma lewisi.

The present study emphasises the importance of the mononuclear phagocytic system of the rat in immunity to infections with Trypanosoma lewisi. Despite the great increase in the weight of the spleen, the liver played a major role in removing the parasites from the circulation. No evidence could be obtained that removal of the parasites was related to the lytic activity of specific antibody and complement.

Animals↗
PubMed1978

Immunity to Nematospiroides dubius: cell and immunoglobulin changes associated with the onset of immunity in mice.

The effect of one or more immunising infections on the susceptibility of mice to a subsequent challenge dose of Nematospiroides dubius larvae has been investigated. Following a single infection, animals developed a partial resistance characterized by their capacity to kill no more than half of the challenge dose of larvae. This low degree of immunity prevailed for some weeks after initial infection. A second immunising infection was found to induce a sudden increase in resistance such that at least 95% of a subsequent challenge dose of larvae was killed. This increase occurred 6 to 8 days after the second immunisation. Similar results were observed for mice immunised orally or intravenously. During the course of immunisations, absolute and differential cell levels in the blood and peritoneum as well as serum concentrations of the various immunoglobulin classes were determined. The results are considered in terms of the possible involvement of two distinct mechanisms of immunity to N. dubius, one requiring the participation of macrophages and the other, eosinophils.

Animals↗
PubMed1978

Changes in the activity of the reticulo-endothelial system of rats during an infection with T. lewisi.

Data presented show that during the course of a Trypanosoma lewisi infection in rats there was both an activation of the phagocytic cells of the liver and spleen and an increase in their numbers. There was a marked lymphoid hyperplasia in the white pulp of the spleen with an increase in the number and size of the lymphoid follicles. Degenerative changes occurred in the liver parenchymal cells during the infection, and at certain stages large numgers of mononuclear cells were observed in the vascular sinusoids and other vessels of the liver.

Animals↗
PubMed1978

Nematospiroides dubius: susceptibility to infection and the development of resistance in hypothymic (nude) BALB/c mice.

BALB/c-nu/nu mice and their intact nu/+ littermates are equally susceptible to infection with third-stage larvae of Nematospiroides dubius. Unlike their heterozygous littermates, however, the nu/nu mice are unable to form ganulomata in the intestinal wall and become only partially resistant to rechallenge. Following two or more infections, nu/nu mice maintain a high burden of adult intestinal worms, whereas worms are lost from immune nu/+ mice. Studies in T cell-injected nu/nu mice suggest that a full complement of T cells is needed to develop maximum resistance against the infective third-stage larvae and to expel adult worms. Measurement of serum immunoglobulin levels indicate that infected nu/+ mice have very high levels of IgG1 whereas the levels of IgG2a are reduced. In infected T cell-injected nu/nu mice, IgG1 levels increase with the number of T cells injected, whereas IgG2a levels are variable but always higher than in infected nu/+ mice.

Animals↗
PubMed1978

Studies in vitro on the reaction of peritoneal exudate cells from mice immune to infection with Nematospiroides dubius with the infective third stage larvae of this parasite.

The results of the present study show that peritoneal exudate cells from mice immune to infection with Nematospiroides dubius are able in vitro to damage the third stage infective larvae as measured by a loss in infectivity. The ability of these cells to function in the absence of specific antibody seems to be related to the presence of trypsin labile factors on their surfaces. Lymphocytes from immune mice are also able to damage the larvae. The suggestion is made that 'activated' macrophages may play an important role in immunity to this infection.

Animals↗
PubMed1978

A method for the assay of ablastin in the serum of rats infected with Trypanosoma lewisi.

This paper describes a simple quantitative assay for albastin, a factor present in the serum from rats infected with Trypanosoma lewisi, which prevents the division of the parasite. The assay measures in vitro the inhibition of the incorporation of 3H-TdR into the DNA of T. lewisi in the presence of serum from infected animals. Utilising this method, one can measure the titre of albastin in a particular serum sample and the time and duration of its appearance in the circulation of infected rats.

Animals↗
PubMed1977

Surface immunoglobulins, a possible mechanism for the persistence of Trypanosoma lewisi in the circulation of rats.

The results presented below show that the dividing and adult forms of T. lewisi share common antigens and indicate that the persistence of adult forms in the circulation of rats immune to reinfection is not due to a change in surface antigens as has been postulated. Using a rabbit anti-rat immunoglobulin serum, the presence of rat immunoglobulins on the surface of adult trypanosomes could be demonstrated. These immunoglobulins were not complement-fixing or opsonic. It is suggested that these immunoglobulins are responsible for the persistence of the adult forms in the circulation of the rat.

Animals↗
PubMed1977

Induction of immunity in mice to the nematode parasite, Nematospiroides dubius.

The data presented in this paper show that mice may be immunised against re-infection with Nematospiroides dubius by giving live third-stage larvae orally, intravenously, intraperitoneally or subcutaneously. Immunity is directed not against the adult worm but against third-stage larvae following their penetration of the wall of the intestine.

Administration, Oral↗
PubMed1976

Passive transfer of immunity to infection with Nematospiroides dubius from immunised mice to their offspring.

The results given below show that, whilst it is not possible to transfer immunity to infections with Nematospiroides dubius passively with serum from immune mice to normal adult mice, young born to immune females are resistant to this infection. The immunity is dependent on an intake of immunoglobulin via the milk for a period longer than 24 h. The passive transfer of immunity from immune mothers to neonatal mice does not appear to be dependent on a specific class of immunoglobulins.

Age Factors↗