Alpha 1-foetoprotein Research Articles

A single layer nitrocellulose substrate for fabricating protein chips

This paper describes the formation of a silanization compound with nitrocellulose to form a thin film by spin coating on glass slide which can be used as a protein chip. This nitrocellulose film is adhered to the glass slide by spin coating directly and can immobilize protein by hydrophobic physical adsorption and epoxy chemical binding simultaneously. Using this spin coating thin film formation technique, both the Cy3 and Cy5 channel backgrounds are reduced by 90% when compared with the original FAST™ slide. The result of an alpha-1-foetoprotein (AFP) antigen sandwich experiment shows an S/N ratio of 68.8 in concentration of 10 ng/mL of AFP antigen, and the dynamic range is between 30 and 3000 ng/mL.

Hepatocellular Carcinoma in Hereditary Tyrosinemia Type I Despite 2-(2 Nitro-4-3 Trifluoro- Methylbenzoyl)-1, 3-Cyclohexanedione Treatment

Hepatocellular Carcinoma in Hereditary Tyrosinemia Type I Despite 2-(2 Nitro-4-3 Trifluoro- Methylbenzoyl)-1, 3-Cyclohexanedione Treatment

Characterization of a major development-regulated serum thyroxine-binding globulin in the euthyroid mouse

We confirm our finding of a major development-regulated thyroxine-binding globulin (TBG) in the serum of the euthyroid mouse and investigate a number of its binding, structural and regulatory properties. Between 16 days foetal and 60 days postnatal life, the thyroxine (T4)- and tri-iodothyronine (T3)-binding activities of the sera show a striking ontogenic pattern: the binding is 2-3 times higher in foetuses than in mothers, then further increases after birth, reaching between 3 and 5 days maximum values which are 7-8 times higher than the adult ones. This pattern is not correlated with the ontogenesis of the acknowledged specific (transthyretin, TTR) and non-specific (albumin, alpha 1-foetoprotein) thyroid-hormone carriers of the mouse sera. PAGE studies demonstrate that the protein responsible for the elevated binding of the perinatal period is an alpha 1-globulin, with a migration similar to that of human and rat TBGs. Scatchard analysis is consistent with the notions that the T4-binding sites of TBG have high association constants, about two orders of magnitude above the T4 sites of TTR (10(9) M-1 as against 10(7) M-1) and low capacities (37 and 4 nmol/g of serum proteins in pups and adults respectively). Isoelectric focusing (i.e.f.) demonstrates that mouse TBG is a microheterogeneous protein separable, as a function of the pH gradient, in up to 10-12 isoforms, Marked shifts of the relative abundance of isoforms in the course of development are evidenced. The modulation of the TBG binding activity by non-esterified fatty acids (NEFA) and the control of its synthesis by the thyroid status are also reported. Mono- and poly-unsaturated NEFAs are strong inhibitors of the TBG, although they affect TTR less readily. On the other hand, the biosynthesis and/or secretion of TBG, but not of TTR, is under thyroid-hormone control, experimental hypothyroidism inducing a marked increase of the serum TBG. The TBG of mouse behaves as a highly significant parameter of development, pointing to a likely important function of the protein in the process of maturation. Our finding of major TBGs in both euthyroid rats and mice suggests that TBG is more widely spread than was thought until now, but difficult to detect in certain species outside definite maturation stages.

Drug-binding properties of rat alpha 1-foetoprotein. Binding of warfarin, phenylbutazone, azapropazone, diazepam, digitoxin and cholic acid.

As part of an investigation into whether alpha 1-foetoprotein (alpha 1-FP) plays the same transport role in foetal serum as albumin does in the adult, the binding properties of both proteins were compared with respect to the binding of a series of compounds known to be bound by albumin's specific drug-binding sites. The binding of warfarin, phenylbutazone, azapropazone, diazepam, digitoxin and cholic acid by rat alpha 1-FP and serum albumin was studied by equilibrium dialysis at 4 degrees C. Rat alpha 1-FP was shown to have neither albumin's high-affinity site II (diazepam as marker) nor its site III (digitoxin and cholic acid as markers). High-affinity binding by alpha 1-FP was found for the specific markers (warfarin, phenylbutazone, azapropazone) of albumin's drug-binding site I. However, instead of albumin's one high-affinity site/molecule, a mean value of 0.5 site/molecule was obtained with rat alpha 1-FP. Charcoal treatment at neutral pH of rat serum albumin did not affect its measured binding properties, but treatment of the alpha 1-FP led to an increased affinity for warfarin, phenylbutazone and azapropazone without a change in the measured number of sites, indicating competition for binding at this site by (an) endogenous ligand(s). These results are discussed in terms of the structures of the two proteins and with respect to the physiological implications of the differences found.

The treatment of infantile embryonal carcinoma (Yolk-Sac Tumour) of the testis in children.

The case histories of five patients with an infantile embryonal carcinoma are presented. Personal observations and data from the literature indicate that treatment of this tumour is dependent on the patient's age. Non-operative staging is possible under age 1 (alpha 1-foetoprotein and CT-scan). Staging should include a laparotomy in patients aged between 1 and 2 years. Under age 2, retroperitoneal lymph node dissection is indicated only if metastases are demonstrable. From age 2 on, retroperitoneal lymph node dissection should be performed if possible: unilaterally in the absence, and bilaterally in the presence of retroperitoneal metastases. Chemotherapy is required only in cases with metastases. Radiotherapy is not indicated in the treatment of infantile embryonal carcinoma.

The serum competitor of oestrogen--rat alpha 1-foetoprotein interactions. Identification as a mixture of non-esterified fatty acids.

The novel endogenous serum ligands of rat alpha 1-foetoprotein previously demonstrated in different mammalian sera were identified by g.l.c.--mass-spectrometric methods as a mixture of non-esterified long-chain and predominantly unsaturated fatty acids. Detailed comparative analyses of these ligands extracted from foetal- and pregnant-rat sera, rat amniotic fluid and foetal human sera are presented. We also show that an important fraction of these ligands remains associated with the rat alpha 1-foetoprotein after purification; analyses are given for the composition of this lipid moiety of the foetoprotein. The physiological relevance of these results is discussed.

Further characterization of a melanoma-specific protein from human urine.

Isolation of a melanoma-specific protein (MSP) from human urine has been achieved using antibody affinity chromatography. MSP migrates as a single homogeneous protein on SDS PAGE and comparison of these data and ultracentrifuge analyses indicates that MSP contains a single polypeptide chain. MSP, however, shows considerable charge heterogeneity on isoelectric focusing. The desialo form, alpha 2 MSP, is found predominantly in patients with advanced metastatic disease, whilst only the sialo form alpha 1 MSP, is obtained from the urine of patients with early-stage disease. MSP does not react with antisera raised to alpha 1 foetoprotein (AFP) or carcinoembryonic antigen (CEA) and hence is immunologically distinct from these other tumour-associated glycoproteins. Antisera raised to MSP do not react with normal skin melanocytes nor with any foetal tissue tested, and hence the origin of MSP remains unresolved.

Relations between fatty acids and oestrogen binding properties of pure rat alpha 1-foetoprotein

A delipidation procedures based on treatment with charcoal at pH 3 has been applied to highly purified rat alpha 1-foetoprotein preparations. The oestrogen binding properties of the delipidated proteins have been studied with an equilibrium dialysis technique, and compared with the properties of the untreated foetal protein, as well as those of preparations reconstituted from the defatted α 1-foetoprotein and the removed lipids. An important increase has been evidenced for the binding levels of oestrone, oestradiol-17β and diethyl-stilboestrol by the delipidated α 1-foetoprotein. A reversal of this effect has been obtained by incubating the delipidated protein either with the lipids extracted from the purified α 1-foetoprotein or with a potent competitor of the rat α 1-foetoprotein-oestrogen interaction, designated as ‘L’, previously demonstrated and isolated from whole rat sera, and tentatively characterized as a mixture of fatty acids. Scatchard analysis of the oestrone and oestradiol-17β binding parameters show that the enhanced fixation of the hormones after defatting is primarily due to a two-fold increase of the apparent number of binding sites/ mol α 1-foetoprotein. The results are interpreted in terms of the probable, at least partial, identity between the lipids closely associated with the pure α 1-foetoprotein and the fatty acid mixture ‘L’ isolated from whole sera. The possible biological role of a complex interplay between oestrophilic α 1-foetoproteins, phenolsteroids and fatty acids in the control of eostrogen levels during development is discussed brieftly.

Serum alpha1-foetoprotein levels in 153 male patients with germ cell tumours.

--alpha1-Foetoprotein (AFP) levels have been measured by radioimmunoassay in the serum of 153 male patients with gonadal and extragonadal germ cell tumours. Thirty-five patients with pure seminoma, and 34 patients with teratoma but without any postoperative evidence of residual or recurrent tumour, consistently had normal serum AFP levels (less than 25 ng/ml). Of 84 patients with active teratomas, 56 (67%) had serological evidence of AFP production. Ten patients with histological evidence of pure yolk sac (endodermal sinus) tumours all had raised levels. Teratomas containing yolk sac (elements may or may not be associated with raised serum levels. Trophoblastic (choriocarcinomatous) elements in a teratoma were not normally associated with high values. Fourteen patients with teratomas had elevated levels in the absence of histologically detectable yolk sac elements. Serum AFP levels often became elevated before clinical evidence of recurrence, so that AFP can act as an effective marker of the course of the disease and its response to therapy in many patients, but recurrent or progressive disease may be present in the absence of raised levels.

Alpha1 foetoprotein in the diagnosis of hepatoma—statistical and cost benefit aspects

Alpha1 foetoprotein in the diagnosis of hepatoma—statistical and cost benefit aspects

Primary liver cell carcinoma (PLCC) in the Northern Guinea Savanna of Nigeria

There is a high prevalence of primary liver cell carcinoma in the Guinea Savanna country of Nigeria, one of the highest frequencies in the world. The highest frequency of the tumour was among males aged 20 to 49 years. The clinical and laboratory findings are similar to those found in other series in Africa. Alpha 1-foetoprotein occurred in 85% of cases while HBsAg was noted in 49% of cases.