Alpha-1-antitrypsin types and serum levels in toxoplasmosis

alpha 1-Antitrypsin (PI) types were studied in patients with toxoplasmosis (n = 84) and controls (n = 143) using isoelectric focusing. The patients showed a lower frequency of rare types (p less than 0.025) and a higher frequency of individuals with increased PI levels (p less than 0.005) compared to controls.     

Alpha-1-antitrypsin phenotypes in a population of Jordan

Frequencies of the three common subtypes of PI M were studied in a Jordanian population. In comparison with other populations, PI*M3 was found to be low (0.038) and PI*M2 rather high (0.155).     

Alpha-1-antitrypsin (Pi) subtypes in the Spanish Basque provinces

Alpha-1-antitrypsin subtypes were studied in resident (644) and native (222) individuals from the Spanish Basque Country. The gene frequencies were similar to those in other Spanish populations but the isolated valley of Arratia deviated significantly with increased frequencies of the M2 and M3 alleles and a decrease of the M1 allele.     

Alpha-1-antitrypsin and transferrin null alleles in the Portuguese population

In a Portuguese family, a null allele was found in the Pi system. An apparent 'exclusion' of the mother was found to be due to the presence of null alleles in mother and child. A transferrin (Tf) null allele was found in a case of disputed paternity. The mother and putative father were heterozygous for Tf null alleles and the child was homozygous (TfQ0) and presented hypotransferrinemia.     

Alpha-1-antitrypsin (PI) subtypes in Russians and Poles.

alpha-1-antitrypsin (PI) subtypes were studied in Poles and Russians. The frequencies of the PI alleles were similar in the two populations, with the exception of the Z allele, whose frequency was significantly lower in Poles. The M3 allele frequency, which is highly heterogeneous in European populations, has medium frequencies in Poles and Russians.     

Alpha-1-antitrypsin from mouse serum isolation and characterization

Alpha-1-antitrypsin (alpha-1-protease inhibitor) was isolated from mouse serum by a series of electrophoretic and chromatographic steps. We found it to be a glycoprotein of a mass ratio of 57.7 Kd. The extinction coefficient was E1%1cm,280=4.74. It inhibits bovine trypsin, human granulocytic and porcine pancreatic elastase. Its concentration in serum differs between inbred strains. Of those tested the concentration in C57BL/6J males was lowest with 5.58 +/- 0.71 mg/ml (females: 3.02 +/- 0.39) and that in DBA/2J was highest: 8.5 +/- 0.87 mg/ml (females: 4.09 +/- 0.51). The concentration of alpha-1-antitrypsin in male serum was almost twice as high as that in females of all strains tested.     

Structural difference between the normal PiM1 and the common PiM2 variant of human alpha 1-antitrypsin.

The common PiM2 variant of human alpha 1-antitrypsin (alpha 1-AT) which can be distinguished from the wild type PiM1 by isoelectric focusing (IEF) in a narrow pH gradient, was purified to homogeneity from plasma of a homozygous PiM2/PiM2 subject. The specific trypsin inhibitory activity and the amino acid and carbohydrate composition of the normal PiM1 and the variant PiM2 are very similar. The structural difference between the normal and the variant inhibitors was elucidated by peptide mapping of their tryptic digests. An amino acid substitution of glutamic acid in the normal inhibitor by aspartic acid in the variant inhibitor was found. The same amino acid substitution was found in PiMN, which was presumed to be identical to PiM2 based on their IEF patterns.     

Alpha-1-antitrypsin variation in Southern Africa

Eleven Southern African populations were shown to be polymorphic at the alpha 1-antitrypsin locus. A 'new' electrophoretically detectable alpha 1-antitrypsin variant (PiWsan) which has a lower isoelectric point than does PiM, was found in the Bantu-speaking Negro and San populations. PiWsan appears to be functionally normal as judged by quantitative and qualitative studies.     

Alpha-1-antitrypsin: New perspectives and clinical applications

AAT is a 394-residue single chain glycoprotein and functions as the major protease inhibitor of the human body. In this capacity, it prevents neutrophil elastase and other proteolytic enzymes released during inflammatory reactions and during phagocyte death from destroying normal tissues of the body. An inherited, autosomal recessive disorder of AAT is an important cause of emphysema and childhood cirrhosis in individuals of northern European descent. These disorders have been discovered to result from mutations in the AAT gene, located at q31–32.3 on chromosome 14. More than 75 AAT alleles have been identified, some of which are associated with reduced or absent antiprotease activity. Recently, ATT has served as a model for the treatment of human autosomal recessive disorders. This is presently done through the infusion of purified plasma or recombinant AAT. However, in the near future normal human cells may be genetically engineered to produce and secrete the missing molecule.     

Alpha-1-antitrypsin types in five Chinese national minorities

Summary The frequencies of alpha-1-antitrypsin alleles were determined for five Chinese national minorities: Uigur, Korean, Mongolian, Chuang, and Li. PI^*S and PI^*Z alleles are not found in the five populations studied. PI^*ETOK allele is present in Korean, Mongolian, and Chuang populations, and Etokyo is a very common alpha-1-antitrypsin variant in Chinese. Other alleles which occur in more than one of the minorities are PI^*X (Mongolian and Chuang) and PI^*M4 (Korean and Uigur). The high frequency of PI^*M4 in the Uigur population suggests a probably Occidental origin of this nationality.     

Alpha-1-antitrypsin in human mast cells immunofluorescent localization

Proteases are present in the cytoplasm of tissue mast cells in an active form and several explanations have been offered as to how self digestion is prevented. Our studies demonstrate that alpha-1-antitrypsin, a natural protease-inhibitor is present also in the mast cell cyt$\text{o}$ plasm. This finding suggests that a protease inhibitor complex is formed and thus could effectively prevent the proteolytic action inside the cell.     

Alpha-1-antitrypsin (protease inhibitor) phenotypes and longevity

We have tested the hypothesis that the protease inhibitor phenotypes MZ and MS are disadvantageous and reduce survival by comparing the prevalence of these phenotypes in a group of 707 very old people (hospital patients) with the prevalences reported in younger populations of blood donors. The MS and MZ phenotypes appear to be no less common among those who have survived to old age, but a highly significant difference was found in the occurrence of the M subtypes. The M1 type was more common in the elderly, and the M heterozygotes were less common than would be predicted from the reported incidence in younger groups and from the Hardy-Weinberg equilibrium. This discrepancy appeared to be smaller in subjects of Mediterranean origin than in those of British or Irish genetic background.     

Alpha-1-antitrypsin immunoreactivity in islet cells of adult human pancreas

alpha-1-antitrypsin immunoreactivity was demonstrated by immunofluorescence technique in the peripheral islet cells of all ten normal adult human pancreata examined; normal adult human liver was negative. The specificity of the reactions was confirmed by applying various control tests including absorption of the specific antisera with purified alpha-1-antitrypsin, inhibition and blocking tests and by ensuring the monospecificity of the antisera used. The findings suggest that the pancreatic islet may be an additional source of alpha-1-antitrypsin.     

alpha1-antitrypsin: common subtypes of Pi M.

More than 20 different alleles are so far known at the Pi locus, corresponding to a total variant phenotype frequency of about 10% in most western Europeans. The common phenotype Pi M constitutes the remaining major group. Now it has been possible to identify three subtypes M1, M1M2 and M2, corresponding to the gene products of two common alleles PiM1 and PiM2, segregating as autosomal codominant alleles. Preliminary gene frequencies are reported for eight populations, the PiM2 frequency varying from 0.20 in Maris (USSR) to 0.02 in Bantus (Kenya).     

Alpha-1-antitrypsin phenotypes in newborns from Central and Southern Italy.

The results of Pi typing on 500 infants from Central and Southern Italy are reported. Phenotype determinations were performed on umbilical cord serum. We observed nine different phenotypes; each of these is present in other European populations. The frequencies of the Pi alleles in our group were found to be, on the whole, comparable to those found in other populations widely separated geographically. However, the frequency of the Pi S gene in our sample (0.0670) was greater than that observed in Northern and Central European and American groups. Our Pi S frequency was similar to that found in a French group and lower than that of Spanish and Portuguese groups. Our data thus confirm the higher Pi S gene frequency in Latin populations.     

Alpha-1-antitrypsin (Pi) types in Korean and Chinese populations

Summary Alpha-1-antitrypsin phenotypes were determined by isoelectric focusing in 270 Koreans and 52 Chinese. The frequencies of the major alleles were the following, numbers for the Chinese sample are in parentheses: Pi^M1: 0.65 (0.66), Pi^M2: 0.22 (0.25), Pi^M3: 0.06 (0.09). Other alleles, including Pi^Z were present in low frequencies. The Koreans appear to be quite similar to the Chinese in this system.