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Biomedical subjects

J Lieberman

Publications and source records attributed to J Lieberman.

At least 217 records · Page 12Linked to original sources

Molecular abnormality of PI S variant of human alpha1-antitrypsin.

Alpha1-antitrypsin variant protein was purified to homogeneity from a PI S-S subject with a mild deficiency of plasma trypsin inhibiting capacity. Molecular weight, specific trypsin inhibitory activity, and composition of amino acids and carbohydrates were similar to the proteins purified from Pi M-M individuals with normal alpha1-antitrypsin activity. The structural difference between the normal and the variant alpha1-antitrypsin was elucidated by peptide mapping of their tryptic digests. An amino acid substitution of glutamic acid in the normal protein to valine in the variant protein was found. The result is consistent with the previously reported amino acid substitution in Pi S-Christchurch.

Amino Acid Sequence↗

[Locked twins].

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Cesarean Section↗

Alpha-1 antitrypsin levels and prevalence of Pi variant phenotypes in asthmatic children.

A total of 151 children with severe atopic bronchial asthma were screened for AAT levels by the STIC and RID methods. They were also phenotyped by the method of acid starch electrophoresis and crossed immunoelectrophoresis. The results were compared with those in a like control age group of children without known pulmonary problems. Both groups revealed similar incidences of AAT deficiency and 3% phenotype Z variants. The children with steroid-dependent severe asthma had a greater proportion of Z heterozygote variants than the non-steroid-dependent asthmatic and control population.

Adolescent↗

Molecular abnormality of human alpha1-antitrypsin variant (Pi-ZZ) associated with plasma activity deficiency.

A human alpha1-antitrypsin variant protein was purified to homogeneity from homozygous variant subjects (Pi-ZZ) who had a deficiency of plasma trypsin inhibitory capacity. Molecular weight, specific trypsin inhibitory capacity, and immunologic activity of the variant protein were identical to those of normal. Amino acids, N-acetylglucosamine, and hexose contents were closely similar in the normal and variant proteins, but the sialic acid content in the variant protein was significantly lower than normal. The structural difference between the normal and the variant alpha1-antitrypsin was elucidated by fingerprinting of their tryptic peptides. Two amino acid substitutions, i.e., glutamic acid in the normal protein to lysine in the variant protein, and glutamic acid in the normal protein to glutamine in the variant protein, were found.

Amino Acids↗

The specificity and nature of serum-angiotensin-converting enzyme (serum ACE) elevations in sarcoidosis.

Elevation of serum-angiotensin-converting enzyme (serum ACE) in patients with active sarcoidosis was confirmed in a total of 64 subjects with a mean serum ACE of 15.76+/-7.4 units compared with 6.05+/-2.0 units in 194 patients with other types of respiratory disease. Resolution of the sarcoidosis disease state or therapeutic control with adequate doses of corticosteroids (15 mg prednisone daily) brought the elevated serum ACE levels down into the normal range. A longitudinal study of serum ACE activity was found to be an effective way of judging the therapeutic efficacy of various steroid dosage levels. No other disease state involved in the differential diagnosis of sarcoidosis was found to have elevations of serum ACE activity. However, 6 patients with Gaucher's disease did have elevated serum ACE activity that ranged well above the usual level seen even in patients with sarcoidosis. The two diseases could be readily distinguished in the laboratory by elevated serum acid phosphatase activity in most cases of Gaucher's disease. It would appear that detection of elevated serum ACE levels can be a useful procedure for confirming a diagnosis of active sarcoidosis and for judging the therapeutic response.

Adult↗

A new deficient variant of alpha1-antitrypsin (MDUARTE). Inability to detect the heterozygous state by antitrypsin phenotyping.

A new molecular variant of alpha1-antitrypsin was discovered in the family of a woman with severe antitrypsin deficiency and bullous emphysema. The variant resembles the Z variant in most respects in that it results in severe antitrypsin deficiency with the homozygous state and intermediate deficiency with the heterozygous state, and is associated with diastase-resistant, periodic acid-Schiff-positive globules in the liver cells. It differs from the usual Z variant, however, by having normal mobility on acid-starch electrophoresis so that the heterozygous state with the normal M form cannot be distinguished by phenotyping procedures on either acid-starch or alkaline-agarose electrophoresis. The variant has been labeled MDUARTE. A review of phenotype patterns in all patients previously classified as having a homozygous ZZ phenotype reveals extra, fast-moving bands on acid-starch suggestive of an MDUARTEZ heterozygous state in 7.9 per cent of such cases. When intermediate antitrypsin deficiency occurs in the presence of a normal phenotype pattern, one must consider that the patient has inherited either a null gene for antitrypsin synthesis or an MDUARTE variant.

Female↗

The source of a minor alpha 1-antitrypsin in variant serum.

An antiserum produced against human alpha1-antitrypsin gave 2 precipitin lines by immunodiffusion when tested against sera displaying MZ or MS phenotypes. Only one line (major antigen) was seen with sera displaying M phenotype, but a second line (minor antigen) became evident when the serum was concentrated 5-fold. The minor antigen appeared to be a denatured form of alpha1-antitrypsin, because the major antigen was converted to the minor one when purified alpha1-antitrypsin was incubated between pH 2.95 and 4.0. Such incubation inactivated the protein irreversibly. The purified protein was also inactivated completely within 1 hour at pH 4.95, but the activity was recovered completely by incubation for 2 to 4 hours at pH 8.0. The immunologic properties of the reactivated a1-antitrypsin were the same as those of the original untreated protein.

Humans↗

Racial distribution of alpha1-antitrypsin variants among junior high school students.

A survey of alpha1-antitrypsin phenotypes and serum trypsin inhibitory capacities was performed in 1,841 seventh grade junior high school students. Antitrypsin deficiency states were detected only in white subjects (3.04) per cent) and not in 461 subjects of other races or of Mexican origin. A screening level of serum trypsin inhibitory capacity at 75 per cent of normal or less included all of the deficient phenotypes, but phenotyping was necessary to eliminate a small percentage of normal and unimportant variant phenotypes from this group. It is suggested that future programs for detecting antitrypsin deficiency and for counseling students who are genetically prone to develop pulmonary emphysema be aimed primarily at white populations.

Adolescent↗

Intermediate alpha1-antitrypsin deficiency resulting from a null gene (M-phenotype).

The presence of a null gene for alpha1-antitrypsin was detected in a family study by the inheritance of intermediate antitrypsin deficiency in association with a normal (PiM) phenotypic pattern. The proband, a 42-year-old man (M-phenotype), was a cigarette smoker and had physiologic evidence of pulmonary emphysema. Three female members of the family were receiving estrogenic medication but had deficient values for serum trypsin inhibitory capacity nevertheless, indicating an unresponsive gene. The mean serum trypsin inhibitory capacity for those with an M-phenotype was significantly lower than that found with an MZ phenotype, presumably due to the total noncontribution to serum antitrypsin activity by the null gene. A quantitative measurement of antitrypsin activity or concentration is necessary in an antitrypsin screening program, since phenotyping procedures alone cannot reveal the null gene.

Adult↗

Simplified alpha1-antitrypsin phenotyping by immunofixation of acid-starch gels.

Immunofixation of acid-starch gels represents a simplified method for alpha1-antitrypsin phenotyping. This technique reduces the amount of work and time involved in phenotyping by eliminating the need for crossed-immunoelectrophoresis. Its major purpose is to directly enhance the staining quality of the minor bands, especially the Z bands on the acid-starch gel. It is hoped that this modified method will allow more wide-spread use of antitrypsin phenotyping, especially in the routine clinical chemistry laboratory.

Antibodies↗

Elevation of serum angiotensin-converting-enzyme (ACE) level in sarcoidosis.

The level of serum angiotensin-converting enzyme (ACE) was elevated in 15 of 17 patients with active sarcoidosis. Serum ACE was studied to determine the effect of chronic lung disease upon the blood level of an enzyme believed to originate from the lungs. The assay was performed in approximately 200 control subjects and 200 patients with chronic lung disease using hippuryl-L-histidyl-L-leucine as substrate. Enzyme activity greater in male control subjects than in female subjects of comparable age and greater in children than in adults. Serum ACE was significantly reduced in patients with chronic obstructive lung disease, lung cancer, tuberculosis and cystic fibrosis, as compared to control subjects, and was even lower in those receiving corticosteroids. Of greatest interest, however, was that levels in patients with active sarcoidosis not receiving steroids were greater than 2 standard deviations above the mean for the adult control subjects (greater than 11.6 units) whereas levels in patients with sarcoidosis receiving steroids and in those with resolved disease were normal. A survey of subjects with other granulomatous diseases failed to reveal any other condition that was significantly associated with a similar elevation of serum ACE levels. Elevation of ACE levels in sarcoidosis appears to be associated with the active disease process and does not appear to be a familial inherited enzyme abnormality. An assay of serum ACE is a useful tool for regulating therapy in sarcoidosis and for confirming the diagnosis, since it readily distinguishes these patients from others with tuberculosis, lung cancer or lymphoma.

Adult↗

Childhood cirrhosis associated with alpha-1-antitrypsin deficiency. A genetic, biochemical, and morphologic study.

A study of 27 relatives of a child with fatal hepatic cirrhosis due to homozygous Z variant alpha-1-antitrypsin deficiency revealed 15 members with heterozygous MZ phenotypes. Levels of circulating alpha-1-antitrypsin and trypsin-inhibiting capacity were shown to be unreliable in identifying the heterozygous state, Pi typing being necessary for definitive diagnosis. The morphologic evolution of the hepatic changes in this condition have been studied, and the importance of the PAS stain in identification of the characteristic cytoplasmic bodies is stressed.

Autopsy↗

Hepatocellular carcinoma and intermediate alpha1-antitrypsin deficiency (MZ phenotype).

A case history of a 16-year-old boy with hepatocellular carcinoma and an intermediate deficiency of alpha1-antitrypsin (MZ phenotype) is presented. Previous reports have suggested that hepatocellular carcinoma may be associated with the Z variant of antitrypsin and either a severe or intermediate antitrypsin deficiency. The present case is unusual because of the rather high level of the serum trypsin inhibitory capacity for an MZ heterozygote (1.633 units), which may be due to involvement of the liver by the tumor or to a recent partial hepatectomy. PAS-positive antitrypsin globules were seen in the primary tumor and in nodules metastatic to the mesentery, as well as in nonneoplastic portions of the liver. Hepatocellular carcinoma is another disease state that may occur preferentially in individuals with either severe or intermediate deficiencies of alpha1-antitrypsin.

Adolescent↗

Carboxypeptidase B-like activity and C3 in cystic fibrosis.

Assays of carboxypeptidase B-like activity and C3 in serum from patients with cystic fibrosis and appropriate control subjects failed to demonstrate a deficiency of carboxypeptidase B-like activity or a consistent increase in C3, as was suggested by Conover and associates. Differences between men and women with cystic fibrosis were apparent, in that women with cystic fibrosis had higher concentrations of both serum carboxypeptidase B-like activity and C3 than either men with cystic fibrosis or control subjects.

Carboxypeptidases↗

The detection of cross-reacting material for alpha-antitrypsin in liver extracts by acid-starch electrophoresis.

Purified extracts of alpha-antitrypsin cross-reacting material (CRM) from liver of patients with MM, ZZ, and MZ phenotypes were studied by acid-starch electrophoresis and crossed immunoelectrophoresis. It is believed that CRM-M from liver is derived primarily from postmortem digested serum antitrypsin, whereas CRM-Z is a product of postmortem digested antitrypsin from hepatocytes. All extracts produced small bands of antitrypsin on the cathodal side of the gel: A single M band migrated faster than the single Z band, whereas CRM from an MZ heterozygote produced a combination of 2 mobile bands. The CRM-Z (from a ZZ phenotype) did not migrate toward the anode, in contrast to the presence of a broad plateau of antitrypsin protein with CRM-M (from an MM phenotype) or CRM-MZ. Thus, most of the CRM-Z protein could not be accounted for on routine acid-starch electrophoresis. However, an anodal peak could be seen on starch gels with CRM-Z at less acidic pH, suggesting that the anodal-migrating CRM-Z protein is denatured and loses antigenicity at lower pH.

Cross Reactions↗