scholarly journals The passage of antibodies from the maternal circulation into the embryo in rabbits

Active immunity to Brucella abortus was induced in adult female rabbits. They were mated a week after the last injection of antigen and were killed and the yolk-sac contents of the embryos tested for agglutinins 8½ days after copulation. Specific agglutinins were found to be present in the yolk-sac contents in all cases. The titre varied significantly from embryo to embryo in the same litter, and was in some as high as that in the maternal serum at the time of killing. Passive immunity to Br. abortus was imparted to female rabbits 7 to 9 days pregnant by intravenous injection of immune serum of high titre. The rabbits were killed and the yolk-sac fluid of the embryos tested for agglutinins 10 to 17 hr. after injection. Specific agglutinins were present in most of the embryos from five of the six rabbits injected before 8 days post-coitum. All the embryos in the sixth rabbit were regressing. Specific agglutinins were not found in any of the embryos from two rabbits injected after 9 days post-coitum, by which time the yolk-sac fluid has ceased to increase in volume. Positive results were obtained both when rabbit and bovine immune sera were used. Active immunity to Br. abortus was induced in pregnant rabbits by injections beginning after the 15th day post-coitum. The serum of the newborn young, removed from their immune mothers before they had suckled, was tested and specific agglutinins were found to be present with a titre corresponding to that of the maternal serum. It was concluded that agglutinins, whether actively or passively acquired, pass freely from the maternal circulation into the yolk-sacs of 7- and 8-day rabbit embryos. This constitutes a delicate test of the passage of protein without alteration through the yolk-sac wall. The yolk-sac wall does not appear to be selective, since it is at least as permeable to foreign proteins as it is to those of maternal origin. Agglutinins pass from the maternal circulation into the embryo after the disappearance of the bilaminar wall of the yolk-sac also, either by way of the yolk-sac splanchnopleur or the allantochorionic placenta or both. The bearing of these results on current theories of placental permeability are discussed.

1915 ◽  
Vol 22 (2) ◽  
pp. 248-268 ◽  
Author(s):  
Henry T. Chickering

1. The protective substances contained in specific precipitates from antipneumococcus serum can be extracted by suitable chemical and physical agents, dilute sodium carbonate at 42°C. being especially advantageous as an extractive agent. 2. The resulting water-clear extracts, when made up to the original volume of the serum used for precipitation, protect animals almost as well as does the whole serum. 3. The bacterial extracts used in precipitating the protective substances from the serum act specifically; that is, a bacterial extract of pneumococcus of Type I removes the protective substances from a Type I immune serum only. 4. In a polyvalent serum of Type I and Type II, the protective substances of each type may be removed independently of each other by the successive addition of the homologous antigens. 5. Extracts of specific serum precipitates contain only one-fiftieth to one-sixtieth of the protein in the original serum, and about one-half the protein of the whole precipitate. 6. Extracts contain not only protective substances but agglutinins and precipitins. 7. Extracts and whole precipitates not only confer passive immunity but stimulate the production of active immunity to pneumococcus infection in rabbits and mice.


Reproduction ◽  
2001 ◽  
pp. 513-527 ◽  
Author(s):  
WR Allen

The equine embryo takes 6 days to traverse the oviduct and, when it finally enters the uterus, it remains spherical in shape and moves continually throughout the uterine lumen until day 17 after ovulation to deliver its maternal recognition of pregnancy signal to the entire endometrium. Between day 25 and day 35 after ovulation, the trophoblast cells of a discrete annulate portion of the chorion multiply rapidly and acquire an invasive phenotype and, between day 36 and day 38, migrate deeply into the maternal endometrium to form the equine-unique endometrial protuberances known as endometrial cups. These cups secrete large quantities of a gonadotrophic hormone (eCG) into the maternal circulation which, in conjunction with pituitary FSH, stimulates the development of accessory luteal structures in the maternal ovaries to supplement the supply of progesterone to maintain the pregnancy until the placenta can assume this role at about day 100. The non-invasive allantochorion extends slowly to fill the uterus by days 80-85 and its microcotyledonary architecture, which provides both haemotrophic and histotrophic nutrition for the growing fetus, is not fully established until days 120-140. The fetoplacental unit synthesizes large quantities of steroid hormones during the second half of pregnancy, using fetal C-19 precursors secreted by the enlarged fetal gonads for the production of oestrogens and maternal C-21 precursors for the synthesis of progesterone and large quantities of 5alpha-reduced progestagens. Near term, additional pregnenelone is secreted by the fetal adrenal glands so that the mare exhibits the unusual phenomenon of foaling while maternal serum progestagen concentrations are increasing and oestrogen concentrations are decreasing.


2000 ◽  
Vol 7 (1) ◽  
pp. 4-6 ◽  
Author(s):  
D.N. Rausch ◽  
G.M. Lambert-Messerlian ◽  
J.A. Canick

Objective To determine whether women who have had a positive serum screening result in one pregnancy have a lower rate of participation in screening in their next pregnancy. Setting The Women and Infants Hospital triple marker screening programme. Methods Pregnancy and screening information was collected from laboratory and hospital databases to compare subsequent screening participation in women who were screen negative and screen positive for risk of Down's syndrome (DS) or neural tube defect (NTD) pregnancy. Results In an age matched comparison, 108 women who had a previous screen positive result were significantly less likely than 108 women who were screen negative to participate in maternal serum screening in their next pregnancy. When examined according to type of screen positive result, the effect was significant for both those who were screen positive for DS and those who were screen positive for NTD. The degree of risk in screen positive women did not significantly affect their uptake of screening in the next pregnancy. Conclusions Anxiety related to a screen positive result probably causes decreased participation in maternal serum screening in the next pregnancy. Reducing the screen positive rate in prenatal serum screening would alleviate maternal anxiety and would probably lead to more stable participation.


2010 ◽  
Vol 22 (9) ◽  
pp. 69
Author(s):  
G. Nie ◽  
Y. Li ◽  
M. Puryer ◽  
L. Salamonsen

The pathogenic origin of preeclampsia is defective placental development (placentation) and function. Preeclampsia is not diagnosed until later in pregnancy and reliable early detection is highly desirable. HtrA3 is a recently cloned gene with high expression during placentation in the mouse, rhesus monkey and human. In human 1st trimester placenta, HtrA3 is highly expressed in maternal decidual cells and in certain trophoblast cell types. Placental HtrA3 is secreted into the maternal circulation and clearly detectable in serum of pregnant women in the 1st trimester. The present study examined placental production and serum profile of HtrA3 across gestation in women, the potential molecular mechanisms regulating HtrA3 production, and association between maternal HtrA3 serum levels and preeclampsia. Immunohistochemistry determined HtrA3 expression pattern and cellular localization in 1st, 2nd and 3rd trimester placenta. Maternal serum HtrA3 levels were analysed by Western blotting. Regulation of placental HtrA3 production and secretion by oxygen tension was investigated in 1st trimester placental explants and trophoblast cells. Placental HtrA3 protein was maximally produced in the 1st trimester, then dramatically down-regulated, especially in the syncytiotrophoblast. HtrA3 was secreted into the maternal circulation with a serum profile reflecting placental production. Oxygen tension regulated HtrA3; low oxygen enhanced, while transition from low-to-high oxygen decreased, HtrA3 protein production in syncytiotrophoblast. Maternal serum HtrA3 levels at ~13-14 weeks of gestation were significantly higher in women who subsequently developed preeclampsia. It appeared that HtrA3 down-regulation was delayed in preeclamptic pregnancies. In conclusion, HtrA3 protein production is closely associated with oxygen tension in the placenta. The decline in HtrA3 at the end of 1st trimester may reflect the placental low-to-high oxygen switch. Abnormally high levels of serum HtrA3 at the end of 1st trimester is associated with preeclampsia.


1999 ◽  
Vol 1999 ◽  
pp. 189-189 ◽  
Author(s):  
I. M. Bland ◽  
J. A. Rooke ◽  
V. C. Bland ◽  
A.G. Sinclair ◽  
S. A. Edwards

An adequate intake of colostrum by the newborn piglet allows the piglet to acquire passive immunity and develop active immunity. Many studies have looked at the uptake of IgG by piglets in artificial situations rather than by natural suckling. Therefore we investigated the uptake of IgG by piglets whilst suckling naturally and estimated the time of gut closure.A total of 8 multiparous sows (Newsham - Large White x Landrace) were induced to farrow on day 114 of gestation. Colostrum/milk was sampled, using oxytocin where necessary, at 0, 4, 8, 12, 16, 20, 24h and 2, 5 and 7 days after farrowing. Female piglets (average 3 per litter) were fitted with umbilical catheters to allow blood sampling at 0, 4, 8, 12, 16, 20, 24 and 48h; samples were taken at 5 and 7 days of age by venepuncture.


1952 ◽  
Vol 30 (6) ◽  
pp. 503-514
Author(s):  
N. N. Swabb ◽  
G. B. Reed

A series of cultures of typhoid bacilli containing Vi antigen were much more virulent for mice than strains in which the Vi antigen was not present. Vaccines prepared from all the Vi strains tested produced a much higher level of active immunity than vaccines prepared from W types lacking the Vi antigen. Sera of rabbits immunized with vaccines made from Vi strains produced a much higher level of passive immunity in mice than sera of rabbits immunized with non-Vi strains. The Vi antigen contained in vaccines prepared from certain strains and, one in particular, proved to have a greater thermostability and greater general stability, as tested by storage, than the Vi antigen of other strains. An acid extract of a Vi strain produced a high level active immunity in mice.


1935 ◽  
Vol 35 (1) ◽  
pp. 23-37 ◽  
Author(s):  
F. Griffith

The characters of the Aronson Streptococcus from Prof. Neufeld's laboratory at the “Robert Koch” Institute in Berlin have been described. This coccus resembles the pneumococcus in many respects, viz. the appearance of the colonies on the surface of horse blood agar, its virulence and capsule production in mice and rabbits, the production of a specific precipitable substance in the peritoneal washings of infected mice, the formation of firm clumps and masses when mixed with homologous antiserum, the ease of production of active and passive immunity in mice and rabbits by intraperitoneal and intravenous inoculation, the alteration in the morphology of colonies, i.e. the appearance of R forms, associated with attenuation of virulence. It differs from the pneumococcus in the following features: the round shape of the cocci, bile-insolubility and the absence of autolysis in surface colonies, the beta haemolysis of deep colonies in horse blood agar, the production of a soluble haemolysin in broth cultures, the difficulty of producing active immunity in mice by the subcutaneous injection of heat-killed vaccines.I have obtained the Aronson Streptococcus (Neufeld type), which Lance-field places in a group containing chiefly streptococci of bovine origin, from human throats, but there was no evidence in any instance that it was producing disease, and it seems probable that it is not pathogenic for man.The results of my investigation of this strain are in agreement with those of Yoshioka (1923), Killian (1924) and Lancefield (1933, 1934).There are in existence other laboratory strains designated Aronson Streptococcus. These have been found to exhibit specific characters identifying them with the Str. pyogenes. It is proposed that the name Streptococcus Aronson should be confined to strains possessing the characters of Aronson N above described.


1913 ◽  
Vol 18 (1) ◽  
pp. 61-74 ◽  
Author(s):  
B. S. Kline ◽  
M. C. Winternitz

1. Rabbits recovering from one attack of experimental pneumonia possess an active immunity. Such animals may subsequently withstand repeated increasing doses of pneumococci intratracheally. 2. Death may supervene after any one of subsequent injections, but it seems to depend partly upon the chronic changes in the cardiorespiratory apparatus. It may at least be said that it is usually unassociated with a septicemia which is an invariable accompaniment of fatal primary lobar pneumonia. 3. The serum from animals actively immunized by the repeated intratracheal inoculations with pneumococci may be used successfully to confer a passive immunity against the homologous organism.


Pteridines ◽  
1989 ◽  
Vol 1 (2) ◽  
pp. 125-128
Author(s):  
Margareta Norman ◽  
Katarina Bremme ◽  
Peter Eneroth

Summary Neopterin and β2-microglobulin but neither C-reactive protein nor deoxythymidine kinase increased in maternal serum from pregnancy week 20 to 40. Only maternal C-reactive protein concentrations changed during vaginal delivery and after 4 days post partum. Retroplacental plasma levels of neopterin, deoxythymidine kinase and β2-microglobulin were significantly higher than in maternal peripheral serum which was interpreted as an indication of increased activity of the immune system as influenced by the fetoplacental unit. The concentrations of neopterin, deoxythymidine kinase and β2-microglobulin were significantly higher in mixed artero-venous umbilical plasma than in the retroplacental plasma, possibly reflecting activation signals to immunocompetent cells in the neonates. The possibility of a transfer of these compounds from fetal to maternal circulation was also pointed out.


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