Effect Of Α-fetoprotein Research Articles

Coagulation induced attenuation of plasmonic absorption of Au nanorods: Application in ultra sensitive detection of alpha-fetoprotein

The effect of α-fetoprotein (AFP) on the plasmonic absorption spectra of colloidal gold nanorods (GNRs) has been investigated experimentally. Because of the AFP induced aggregation and coagulation, both the intensity and wavelength of the longitudinal surface plasmon resonance (SPR) peak are sensitive to the AFP concentration. It has been found the absorption intensity always decreases monotonously as the AFP concentration is increased. By analyzing the intensity fading of the absorption peak, AFP could be detected with a sensitivity of 0.25pg/mL and an ultra low limit of 0.25pg/mL. What's more, the sensitivity and detection limit could be further improved on the condition of pre-centrifugation of the colloidal GNRs. The corresponding mechanism has also been discussed. Cetyl trimethyl ammonium bromide (CTAB) molecules play the important role in preventing the coagulation of GNRs and affect the AFP detection.

Effect of α-fetoprotein on the count of bone marrow and splenic stromal precursor cells and proliferation of their cultural descendants

The efficiency of cloning of stromal precursor cell increased more than 2-fold in splenic cultures and more than 3-fold in bone marrow cultures 24 h after injection of Profetal preparation to mice in vivo. The number of nucleated cells did not change in the bone marrow and slightly increased in the spleen. Addition of Profetal in vitro 2-fold decreased the efficiency of stromal precursor cells colony formation in mouse splenic cultures and dose-dependently decreased this process in bone marrow cultures derived from these animals, the maximum (5-fold) inhibitory effect was observed in a dose of 50 microg/ml. Addition of Profetal to cultured human bone marrow fibroblasts did not change the content of stromal fibroblasts in cultures. These data indicate the possibility of indirect effect of alpha-fetoprotein on the number of stromal precursor cell in hemopoietic and lymphoid organs.

Effect of α-Fetoprotein and Derived Peptides on Insulin- and Estrogen-Induced Fetotoxicity

Both insulin and estrogen are well recognized as growth-promoting substances at physiological concentrations, but they function as teratogens at high doses. Both agents can affect alterations in fetal and maternal serum human α-fetoprotein (HAFP) levels during pregnancy. In the present study, we have employed animal models of both insulin and estrogen fetotoxicity and teratogenicity in order to study the growth-regulatory properties of HAFP and its derived peptides (HAFP/PEP). We report here the effects of HAFP/PEP on fetotoxicity, congenital malformations, and growth retardation in developing chick and murine fetuses. In the insulin model, HAFP/PEP were effective in reducing both fetal mortality and anatomic anomalies, with the result that growth-retarded fetuses were produced. With HAFP/PEP treatment, fetal demise was reduced by as much as 73 and 63% in murine and chick fetuses, respectively, while fetal anomalies were diminished by 50% during chick development. Genebank searches of identity/similarity in a HAFP/PEP fragment identified matches with a number of proteins associated with glucose, pH, ionic, osmotic, and oxidative stresses, and with heat shock, in addition to stress proteins related to protein folding/unfolding processes. It was proposed that the peptide segment on HAFP may represent a topographic ‘hotspot’, sensitive to stress/shock conditions, which exhibits a propensity for conformational alteration in the tertiary structure of the fetal protein.

Effect of α-fetoprotein and albumin on the uptake of polyunsaturated fatty acids by rat hepatoma cells and fetal rat hepatocytes

The uptake of polyunsaturated fatty acids by rat hepatoma cells and fetal hepatocytes has been studied using albumin and alpha-fetoprotein (AFP) as carrier proteins. Both types of cells took up linoleic (18:2(n-6)) and linolenic (18:3(n-3)) fatty acids at the same rate when they were added complexed either to albumin or AFP at a 1:1 molar ratio. At 37 degrees C a greater incorporation of arachidonic acid (20:4(n-6)) and mainly docosahexaenoic acid (22:6(n-3)) was observed when these acids were bound to albumin (6.5 nmol 20:4(n-6); 6.4 nmol 22:6(n-3) /million cells) as compared to AFP (5.5 nmol 20:4(n-6); 4.3 nmol 22:6(n-3)/million cells). The 20:4(n-6) and 22:6(n-3) uptake seems to be inversely related to the apparent association constants (k'a) between these fatty acids and both proteins (1.3 and 1.5 x 10(-7) M-1 20:4(n-6) and 22:6(n-3) for albumin; 6.4 and 54.0 x 10(-7) M-1 20:4(n-6) and 22:6(n-3) for AFP). Experiments carried out at 4 degrees C indicated that binding of 20:4(n-6) (0.83 nmol/million cells in presence of albumin; 2.16 nmol/million cells in presence of AFP) and 22:6(n-3) (0.83 nmol/million cells in presence of albumin; 1.32 nmol/million cells in presence of AFP) by cell membranes was also inversely related to the k'a of these proteins. At 4 degrees C, the k'a of AFP and albumin for 20:4(n-6) and 22:6(n-3) changed considerably (12.7 and 9.6 x 10(-7) M-1 20:4(n-6) and 22:6(n-3) for albumin; 3.9 and 14.6 x 10(-7) M-1 20:4(n-6) and 22:6(n-3) for AFP) with respect to the k'a calculated at 37 degrees C. Hence, k'a values were higher for albumin and lower for AFP than the corresponding values at 37 degrees C. It was concluded that uptake by cells and interaction of fatty acids with cell membranes depend mainly on the k'a of fatty acids and carrier proteins at equilibrium.

Effect of α-fetoprotein on reparative regeneration of the skin and long bones

The effect of human, canine, and feline α-fetoprotein on reparative regeneration of the skin and long bones of mice and rats was studied. α-Fetoprotein has a stimulating action, through the formation of young connective tissue, on regeneration but without strict species-specificity. Of the various α-fetoproteins studied, a commercial preparation of human α-fetoprotein had the highest physiological activity.

Effect of α-Fetoprotein and Other Serum Factors Derived from Hepatoma-Bearing Rats on the Mixed Lymphocyte Response

Abstract Serum α-globulin fractions isolated by physiocochemical techniques from normal adult Buffalo rats suppressed lymphocyte proliferation in vitro. The factors responsible for mixed lymphocyte culture suppression appeared to be strain specific since they were not demonstrable in the same fractions from normal LBN rat serum. Similar fractionation of the serum from Buffalo rats bearing the Morris Hepatoma 7777 obtained from two different sources also yielded suppressive protein fractions that differed both chemically and functionally. Both variants of this hepatoma produced high serum concentrations of α-fetoprotein (AFP), providing an opportunity to study the possible immunoregulatory role of their fetal-associated globulins. Fractions rich in AFP that lacked other serum α-globulins were obtained by gel filtration chromatography and were devoid of any in vitro immunosuppressive activity. When AFP that was further purified by immunoabsorption was added to mixed lymphocyte cultures, no effect was observed at doses below 400 µg/ml. The MLC response was augmented with higher doses, similar to albumin purified by the same methods.