Effect of Bacterial Endotoxin on an Initial Infection of Nematospiroides dubius in Mice

1969 ◽  
Vol 55 (5) ◽  
pp. 1098
Author(s):  
Paul Van Zandt
1996 ◽  
Vol 76 (02) ◽  
pp. 258-262 ◽  
Author(s):  
Robert I Roth

SummaryHuman endothelial cells, when incubated with bacterial endotoxin (lipopolysaccharide, LPS), modify their surface in association with prominent production of procoagulant tissue factor (TF) activity. This deleterious biological effect of LPS has been shown previously to be enhanced approximately 10-fold by the presence of hemoglobin (Hb), a recently recognized LPS binding protein that causes disaggregation of LPS and increases the biological activity of LPS in a number of in vitro assays. The present study was performed to test the hypothesis that Hb enhances the LPS-induced procoagulant activity of human umbilical vein endothelial cells (HUVEC) by increasing LPS binding to the cells. The binding of 3H-LPS to HUVEC was determined in the absence or presence of Hb or two other known LPS-binding proteins, human serum albumin (HSA) and IgG. LPS binding was substantially increased in the presence of Hb, in a Hb concentration-dependent manner, but was not increased by HSA or IgG. Hb enhancement of LPS binding was observed in serum-free medium, indicating that there was no additional requirement for any of the serum factors known to participate in the interaction of LPS with cells (e.g., lipopolysaccharide (LPS)-binding protein (LBP) and soluble CD14 (sCD14)). Hb enhancement of LPS binding also was observed in the more physiologic condition of 100% plasma. LPS-induced TF activity was stimulated by Hb, but not by HSA or IgG. In serum-free medium, TF activity was not stimulated under any of the conditions tested. Ultrafiltration of LPS was dramatically increased after incubation with Hb but not with HSA or IgG, suggesting that LPS disaggregation by Hb was responsible for the enhanced binding of LPS to HUVEC and the subsequent stimulation of TF activity.


1989 ◽  
Vol 31 (2) ◽  
pp. 193-206 ◽  
Author(s):  
Chahna R. Yagoda ◽  
Ann-Christin Bylund-Fellenius ◽  
Hans Kindahl

Parasitology ◽  
1969 ◽  
Vol 59 (1) ◽  
pp. 203-213 ◽  
Author(s):  
R. J. Bawden

The establishment of N. dubius juveniles was more successful in mice maintained on a diet inadequate to support the full growth potential of the animals than in mice maintained on an adequate diet. The distribution of encysted juveniles along the duodenum was considerably more extensive in the former group of mice.More juveniles were established in male than in female mice within the respective dietary groups, although the pattern of distribution was similar.The distribution of adult nematodes at 10 days after infection was confined to a smaller area of the duodenum than that of the encysted juveniles at 5 days.The differences in distribution of nematodes after 5 and 10 days between the HP and LP mice was not evident after 21 days. The survival of adult nematodes in the HP mice was more successful than in the LP animals.The female nematodes in the LP mice achieved a greater length but were less prolific egg producers than those in the HP mice.A diet inadequate to support the full growth potential of mice was therefore associated with the increased ability of Nematospiroides dubius juveniles to establish themselves in mice compared with the situation in adequately fed animals. The low plane diet, on the other hand, was associated with a decreased ability of the adult nematodes to survive.This work was supported by grants from the Commonwealth Scholarship and Fellowship Plan and the Australian Wool Board. I should like to express my appreciation for the supervision of this work by Professor J. F. A. Sprent and to thank Miss Sharon McFeeter and Mrs Anne McKeown for their most competent technical assistance.


Parasitology ◽  
1961 ◽  
Vol 51 (3-4) ◽  
pp. 499-510 ◽  
Author(s):  
Colin Dobson

1. The male rat is more susceptible to infections ofNematospiroides dubiusthan the female. As the rat grows older the resistance of the female rat to infection increases at a greater rate than that of the male.2. The course of the infection is modified by the sex of the host.3. More larvae penetrated the intestinal mucosa to encyst in the male than in the female. More larvae, however, formed cysts in the female than in the male rat by the fifth day.4. The male harboured more adult worms than the female rat, although this difference was not significant in the immature animals.5. The sex resistance of the rat toN. dubiusinfections was removed by bilateral gonadectomy. Castration decreased the susceptibility of the male rat, while spaying increased it in the female compared with the susceptibility in the respective normal hosts.6. Subsequent replacement of the homologous sex hormone in the gonadectomized rat restores the sex resistance, and may even increase it (particularly in the immature animals). Oestradiol increased the resistance of the spayed female rat, while testosterone increased the susceptibility of the castrate male rat to infection.7. Oestradiol implanted in castrate male rats increased the resistance of these hosts to a greater level than was shown in the normal male rat.8. The rat shows a marked age resistance over which the sex resistance is superimposed.9. The relationship between the sex of the host and its resistance to infection is discussed.This work was done during the tenure of a Department of Scientific and Industrial Research Studentship. My thanks are due to Dr E. T. B. Francis for his helpful and critical supervision and to Professor I. Chester Jones, in whose department the work was done, for the facilities he provided.


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