Anatomical and histological anomaliesin chick embryos from hens immunisedto chick embryo solubleand foreign antigens

The anatomical and histological alterationsthat affect chick embryos from hens immunizedwith antigens from chick embryos, butwhich are foreign to the immune system of thehen, are reported here for the first time. Theimportance of these antigens, the maternalantibodies that they induce, and the injuriesthat these produce in the embryo can clearlybe seen in the results reported. These results,obtained by means of experimental immunizationin hens, may also hypothetically takeplace in humans (women) through naturalimmunization because analogous antigensfrom the embryo cross her placenta.Thus 81 eggs of immunized hens werestudied, of which 60 displayed morphologicalterations of diverse intensity, especiallydevelopmental delay and growth retardation.Of these, three embryos 57 pih, 4 and 7 pidwere chosen for their delay in growth, duringthe period of organogenesis. Their anatomicalalterations were studied and an exhaustive andqualitative histological analysis was carriedout. Each section was compared with those ofcontrol embryos which underwent the sametime of incubation or were at the same stage ofdevelopment. Embryonic growth retardationwas evident in the smallest size of the embryosbut also there were developmental delay ofsome organs and cells. Among other strikinganomalies, the following were observed: invasionof the neural crest cells into the mesencephalonand rombencephalon lumen;malformation of the infundibulum; disintegrationof dermatomes and myotomes; a loosearrangement of mesenchymal tissue; a delay inthe development of the heart and bloodislands cells, etc. Some of the observed anomalieswere related to birth defects that alsoaffected other chicks in the same experiment,as published elsewhere (AU)

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New fetoproteins, as presumptive antigenic inducers of abortions and congenital anomalies. Temporal forking of immunological abortions. A working hypothesis.

In a previous experimental study soluble alloantigens and soluble foreign (not recognized by the dam's immune system) transitory antigens in chick embryo have been detected. When a chick embryo extract was injected in hens and their eggs were incubated, the death or a delay in chick embryo development or congenital anomalies were observed. Based on the foregoing, the following working hypothesis is established: any fetoprotein not coming into contact with the fetal immune system during the central clonal selection period becomes a foreign antigen. If it is a female fetus that becomes pregnant at adult age, then passage to the maternal circulation or to the decidua of the same foreign fetoprotein from her fetus is a candidate to induce a humoral or cell-mediated response. If specific IgG or toxic factors of the different cells activated by cell-mediated immunity in the mother access the inductive antigen (e.g., an enzyme) in the conceptus, there functions may be cancelled or the antigen-carrier cell may undergo lysis. This will result in damage to tissues leading to abortion or to a viable but morphologically or functionally abnormal offspring. This can occurs with some of soluble foreign transitory antigens existents. The soluble alloantigens are foreign for the mother because are coded by paternal genes and act of similar way.

Detection of squalene in alpha-fetoprotein and fetal serum albumin from bovine.

Alpha-fetoprotein and fetal serum albumin have been simultaneously purified from fetal bovine serum by mild procedures utilizing ammonium sulfate, hydrophobic interaction, immobilized metal (nickel) affinity chromatography, and isoelectric focusing. The lipidic extract from each protein was analyzed by gas chromatography and the peak appearing just after the arachidonic acid was identified as squalene by gas chromatography-mass spectrometry. This isoprenoid was not detected formerly in these proteins from human, rat, bovine, and pig. Until recently, in the analysis of the fatty acid composition of the alpha-fetoprotein and serum albumin from mammals, a peak has been assigned in the last part of the chromatographic profile, after arachidonic acid, to docosahexaenoic acid. In the present work, it was found that the peak corresponds to squalene instead of docosahexaenoic acid. Furthermore, we conclude that bovine alpha-fetoprotein and fetal serum albumin carry squalene, but not docosahexaenoic acid. These results agree with others obtained analyzing the same proteins from chick embryo.

Isolation and characterization of a protein from Mendole (Spicara maena) eggs that binds to DNA and inhibits its replication as well as its acid precipitation.

Proteins that bind and protect nucleic acids from acid precipitation have been characterized from human and mouse plasma. In the present study, one protein from Mendole (Spicara maena) eggs was purified to homogeneity, by means of acetone fractionation and Sephadex G-100 gel filtration. The protein inhibited DNA replication, exerted by various DNA polymerases. Amino-acid sequence analysis in the amino terminus revealed a unique sequence. Its possible physiological role is discussed.

Fatty acids and squalene carried by alpha fetoprotein, and fetal and adult serum albumin from chicken. Comparison with these from mammals.

Alpha fetoprotein (C-AFP), serum albumin (C-fSA) from chicken embryos, and SA from hens were purified using gentle chromatographic and electrophoretic methods, and their fatty acids (FAs) and squalene contents were analyzed using gas chromatography and mass spectrometry. In 7-day-old chick embryo, AFP carries 16% and fSA 6% free FAs, the rest being carried as phospholipids, which differs from rat and pig AFP, where all fatty acids are carried like free fatty acids. At this stage C-AFP contains 3.6% arachidonic acid, which falls to 1.7% in 14-day-old embryos. Both of these figures are significantly lower than in humans, rats, calves, and pigs. C-AFP does not transport docosahexaenoic acid, in notable contrast to the mammals mentioned above. The finding of squalene in the two fetal proteins is reported for the first time. During the interval between 7 and 14 days, the proportion of C16:1 n-7 and of C18:2 n-6 increases 10-fold, that of C18:0 quadruples, and that of C18:1 n-9 decreases 3-fold. Squalene increases in this period from 2.2% to 10.0%. The C-fSA of a 7-day-old embryo transports only one FA with more than two unsaturated carbons, arachidonic acid (2.4%). It also contains squalene (1.2%). Similarly, only arachidonic acid (2.5%), but not squalene is found in hen SA. The percentage of saturated and monounsaturated FAs divided by the percentage of polyunsaturated FAs, and the ratios of the percentage of FAs with C14-C18 with respect to those with C20-C22 transported by C-AFP are very different from those of studied mammals.

Antibodies to alpha-fetoprotein disrupt histogenesis in cultured chick retinae.

alpha-Fetoprotein (AFP) is an oncofetal antigen believed to play an important role in normal development and carcinogenesis but very little is known about such a role. We have investigated here the role of AFP in neural retina development by selectively neutralising AFP in vitro. AFP has been immunohistochemically located in different cells and layers of the retina during its development, 4-day-old embryos being the earliest developmental stage when AFP is detected in the growing ganglion cell layer. Seven-day-retinae treated with antibodies to AFP in organ culture for 3 days did not continue to develop in the same way that they do in the egg. Neither the plexiform layers nor the buds of photoreceptor cells were observed after this culture period. In contrast, 7-day retinae cultured in the presence of non-immune serum developed in a manner similar to retinae in ovo. We present here the first evidence, derived by selectively blocking AFP in vitro with specific antibodies for an essential role of AFP in the normal development of the chick retina.

Localization of alpha-fetoprotein during the formation of the neural tube and somites in chick embryo.

Very little is known about the biological role of alpha-fetoprotein (AFP) in normal development. This study was undertaken to look for AFP-positive tissues involved in active morphogenetic and histogenetic events. Using a polyclonal antibody specific for AFP and the immunoperoxidase technique, we have studied the AFP localization during the formation of the neural tube and somites in chick embryo. Immunostaining of early whole embryos, cephalic fold stage, shows a strong immunoreaction for AFP in the cephalic and neural folds. In a more advanced stage of the development (6-somite stage), the AFP expression has followed the caudal direction of the neural fold forming process. Immunostaining of 6- and 9-somite embryo sections shows an increase of AFP expression from the most undifferentiated (the neural fold), to the most differentiated (the neural tube). AFP does not label the non-segmented paraxial mesoderm, from which the somite is derived. Instead, when the paraxial mesoderm is segmented and has formed a somite, AFP positive cells are detected in the somite. The morphological differentiation of somite is joined to one biochemical differentiation, since the myotome and sclerotome cells are AFP positive while the dermatome cells are AFP negative. The sclerotome cells become AFP negative when they surround the notochord to form the vertebral body. The results presented here strongly suggest a close association of AFP with cell proliferation and differentiation.

Protein synthesis by chick (Gallus domesticus) extraembryonic membranes.

1. The protein synthesis in chorioallantoic membrane (CAM), amniotic membrane (AM) and yolk sac (YS) were studied by in vitro culture with 14C L-glutamic and immunoautoradiography. 2. The yolk sac synthesizes transferrin, alpha-fetoprotein (AFP) and serum albumin. These three proteins are also synthesized, but only in slight amounts, by AM. A light synthesis of AFP, transferrin and another unidentified protein is detected in the CAM. 3. At the ultrastructural level, AFP is localized in the rough endoplasmic reticulum of CAM mesodermal cells.

Localization and synthesis of alpha-fetoprotein in chorioallantoic membrane from chick embryo.

Alpha-fetoprotein (AFP) is a major globulin of the embryonic serum of mammals, birds, and other vertebrates. It is synthesized chiefly by the liver and/or the yolk sac. The aim of this work was to confirm the occurrence of AFP in the chorioallantoic membrane (CAM) from 14-day chick embryo. AFP had previously been detected by immunoelectrophoresis in CAM extracts under the suspicion that it could be a mere artifact resulting from blood contamination. The immunohistochemical study of the CAM carried out for this purpose revealed the protein to be solely located in the mesodermal layer. The joint use of organ culture and immunoperoxidase techniques has enabled us to find evidence for the synthesis of AFP in the cells of this layer. These results confirm the occurrence of such a significant carrier globulin to embryonic development in one more tissue that can be added to the short list of AFP-producing tissues.

Soluble fetoproteins in chorioallantoic membrane from chick embryo (Gallus domesticus).

1. Anti-chorioallantoic membrane (CAM) serum was made fetal-specific by absorbing it in a mixture of egg white, fresh yolk and chicken serum, plus liver, lung, heart and spleen from a laying hen. 2. By immunoelectrophoresis, the CAM extract shows three soluble transitory proteins, an oncofetal protein (alpha-fetoprotein) and a soluble organ permanent protein from some of the organs used in the absorption. 3. By assaying crossed heterologous systems, alpha fetoprotein was found in the allantoic, amniotic and yolk fluids after 14 days of incubation; all three proteins were found in amniotic, but neither in allantoic nor in yolk fluid.

[Viral etiology of insulin-dependent diabetes (author's transl)]. / Etiologia virica de la diabetes insulino-dependiente.

Data are collected here that may support the hypothesis that there is an infectious component in the genesis of insulin-dependent diabetes mellitus. The clinical and experimental data on which that hypothesis is based referring to viruses such as: mumps virus, rubella virus, encephalomyocarditis virus, and Coxsackie B viruses, are presented. The authors mention the pathogenic mechanism, which extends over the existence of diabetogenic genes linked to the major complex of the histocompatibility HLA system, as well as the existence of an autoimmune reaction induced by the infecting virus. This review shows up the large gaps that exist in the accurate knowledge we have about the possible infectious etiology of diabetes. However, it also offers different pathogenic possibilities for further experimental investigations on bases that are reasonably scientifically consistent.

Seroepidemiology of the poliovirus in Monrovia (Liberia).

Neutralizing antibodies against poliovirus have been studied in 265 persons in Monrovia (Liberia). 34% of the individuals studied possessed antibodies against the three polioviruses, 23% against two, 26% against one; the remaining 17% showed none. The three poliovirus antibodies were evenly distributed amongst the population, although there was an indication that antibodies to polio 2 occurred more commonly in females than in males. The distribution of the antibodies did not seem to be influenced by place of residence, source of drinking water or social class. Significant variations in the immunological state according to age were noted. The study of concordance and discordance of antibody titre in the blood of neonates and their mothers revealed that the lower percentage of titre concordance for polio 3 has no statistical value. The low titre in the neonates (an average for each poliovirus scarcely above 1:16) is a sign of insufficient titre in the adults. The need for a massive antipoliomyelitis campaign among infants and adult women is stressed.