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Biomedical subjects

R Sesboue

Publications and source records attributed to R Sesboue.

8 recordsLinked to original sources

Isolation and characterization of cDNAs encoding the heavy chain of human inter-alpha-trypsin inhibitor (I alpha TI): unambiguous evidence for multipolypeptide chain structure of I alpha TI.

Human inter-alpha-trypsin inhibitor (I alpha TI) is a plasma glycoprotein of Mr 180,000, which has been described as a single polypeptide chain. Recently, however, we proposed that I alpha TI might be composed of a heavy (H) chain (Mr = 95,000) and a light (L) chain (Mr = 40,000) synthesized by two separate mRNAs. In the present study we have characterized cDNAs for the H chain of I alpha TI. These cDNAs collectively covered two sequences (977 and 1450 base pairs in length) with single open reading frames. The deduced amino acid sequences were highly homologous to each other and well matched with partial amino acid sequences obtained from purified serum I alpha TI. RNA blot analyses of liver RNAs with H- or L-chain cDNAs as probes clearly identified two distinct mRNAs of 3.3 and 1.3 kilobases, which corresponded to H or L chain, respectively. Poly(A)+ RNAs hybrid-selected with H-chain cDNAs coded for polypeptide chains of Mr 90,000-95,000. These results unambiguously establish that I alpha TI is made of multipolypeptides, possibly including one H and two L chains. The H chain contains potential calcium-binding sites and also regions homologous to the proposed reactive site for thiol-proteinase inhibitors. These data indicate that I alpha TI is a complex, multifunctional protein. mRNAs for both the H and L chains were found only in liver.

Alpha-Globulins

[High-density lipoproteins, total cholesterol, triglycerides and serum trypsin activity. Study in chronic alcoholic and withdrawn subjects].

Apolipoprotein is controlled by proteolytic processus and serum trypsin-like activity (STA) may be elevated in some chronic alcoholic subjects. STA, apoA lipoprotein, HDL-cholesterol, total cholesterol and triglycerides were tested in 44 men dealt in 4 groups (subjects with normal or elevated STA, alcoholic or withdrawn). Significantly lower apoA lipoprotein (p less than 0,02) and HDL-cholesterol (p less than 0,001) levels as well as significantly higher triglyceride levels (p less than 0,01) were evidenced in the group with elevated STA compared to the group with normal STA. In another way, a negative correlation between HDL-cholesterol and STA (p less than 0,01) and a positive correlation between triglycerides and STA (p less than 0,001) were noted. The different factors known to modify these lipidic parameters cannot account for such disturbances. The role of elevated STA is evoked.

Alcoholism

Genetic variants of human B component (BF system) and alpha-1-antitrypsin (PI system) in a population from Sardinia.

BF- and PI-type determinations have been performed in a population from Sardinia. The corresponding allele frequencies are as follows: BF*S = 0.5783, BF*F = 0.2189, BF*SO7 = 0.0046, BF*F1 = 0.1982 and PI*M1 = 0.5872, PI*M2 = 0.2041, PI*M3 = 0.0459, PI*M4 = 0.0940, PI*S = 0.0619, PI*Z = 0.0046, PI*N = 0.0023. Whereas the BF system shows the originality of the Sardinian population with a very high BF*F1 allele frequency, the PI system does not reveal any characteristic features.

Alleles

Genetic variants of serum alpha1-antitrypsin (Pi types) in Portuguese.

The results of Pi typing on 330 Portuguese from the area of Lisbon are reported. We found six phenotypes and four alleles out of the 24 described in the literature. The allele PiM is the most frequent as in other populations, PiS shows a high frequency (0.1152), and PiF is absent, which agrees satisfactorily with former studies carried out in Spain. These results are compared with others and the entity of the Iberian population is evoked.

Female

Does alpha-1-antitrypsin P1 null phenotype exist?

A second case of Pi null alpha-1-antitrypsin (AA) deficiency is described. In fact, the serum's subject contains 5 mug of AA per millilitre. With radiolabelled specific antibodies, it is possible to describe the Pi phenotype associated to this deficiency. The pattern which is obtained is like the ordinary Pi M, but 500 times lower than normal values. In contrast to a common deficient variant (ZZ or MZ), the subject tissues do not contain periodic acid-schiff positive inclusion bodies. The "normal" pattern obtained after antigen-antibody crossed electrophoresis, would be in favour of a deficient anomaly hereditarily transmitted.

Alleles

The ultrastructure of hepatocytes in alpha-1-antitrypsin deficiency with the genotype Pi--.

The ultrastructural appearance of the endoplasmic reticulum of the hepatocytes was found to be normal in a 5-year-old girl with alpha-1-antitrypsin deficiency with the genotype Pi--. The liver ultrastructure of this variant is therefore different from that of alpha-1-antitrypsin deficiency with the genotype PiZZ in which aggregates of an abnormal, unsecreted alpha-1-antitrypsin accumulate in the endoplasmic reticulum of the hepatocytes. The normal appearance of the endoplasmic reticulum in alpha-1-antitrypsin deficiency with the genotype Pi-- is compatible with the hypothesis, in this variant, synthesis of alpha-1-antitrypsin is completely, or nearly completely, absent; an alternative hypothesis would be that an abnormal alpha-1-antitrypsin is produced by the liver and secreted into the plasma, but disappears rapidly from the plasma.

Carbohydrate Metabolism, Inborn Errors