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Biomedical subjects

K Berg

Publications and source records attributed to K Berg.

At least 523 records · Page 29Linked to original sources
PubMed1975

Two antigenically distinct species of human interferon.

Rabbit antisera prepared against interferon produced in human fibroblast cell cultures stimulated with poly(1).poly(C) neutralized the activity of interferon preparations produced in various human fibroblast cultures timulated either with poly(1)poly)C) or with viruses. However, these antisera showed no detectable neutralizing activity against interferon produced in cultures of human leukocytes. On the other hand, most rabbit antisera against the human leukocyte interferon were active in neutralizing both homologous interferon and fibroblast interferons. A preparation of antiserum against leukocyte interferon, active against both leukocyte and fibroblast interferons, was shown by affinity chromatography to have two distinct antibody populations, one of which was specific for the fibroblast interferon. We conclude that the heterologous neutralizing activity of sera from rabbits immunized with leukocyte interferon is liekly to be due to the presence of two antigenic species of interferon. The major antigenic species of leukocyte interferon preparations (designated "Le") is distinct from huamn fibroblast interferon. The minor species of leukocyte interferon ("F") is either identical with, or closely related to, interferon produced in human fibroblast cultures.

Animals↗
PubMed1975

Distinct molecular species of human interferons: requirements for stabilzation and reactivation of human leukocyte and fibroblast interferons.

Human fibroblast interferon preparations were completely stabilized to 100 degrees C by sodium dodecyl sulphate (SDS) in the presence of mercaptoethanol, but only a minor fraction of their activities were stabilized by SDS without mercaptoethanol. On the contarary, human leukocyte interferon preparations were completely stabilized to 100 degrees C by SDS in the absence of mercaptoethanol, but only a minor fraction of their activities were stabilized by SDS in the presence of mercaptoethanol. Furthermore, human fibroblast interferon preparations whose activities had been destroyed by boiling at 100 degrees C were completely reactivated by SDS under reducing conditions, but only a minor part of their activities were restored by SDS in the absence of reduction. On the contrary, human leukocyte interferon preparations whose activities had been destroyed by boiling at 100 degrees C were completely reactivated by SDS in the absence of reduction, but only a minor part of their activities were restored by SDS under reducing conditions. These data suggest that there are distinct molecular species of human interferons.

Biological Assay↗
PubMed1975

Lp(alpha) lipoprotein and pre-beta1-lipoprotein in relation to lipid levels in males.

Previous studies have shown that a slow-moving pre-beta-lipoprotein fraction, named the pre-beta1-lipoprotein, occurred significantly more frequently among subjects with coronary heart disease (CHD) than among healthy individuals. This lipoprotein is closely related to, and probably identical with, the Lp(a) lipoprotein. Immunological tests likewise showed that Lp(a) lipoprotein was significantly more common among patients with CHD than among controls. Mean cholesterol and triglyceride levels were higher in pre-beta1-lipoprotein positive than in pre-beta1-lipoprotein negative individuals. Lp(a+) individuals tended to have higher serum cholesterol values than did Lp(a-) persons but there was no difference in the mean triglyceride value. This apparent discrepancy seems to be due to the presence in occasional sera of lipoprotein fractions with pre-beta1-mobility, usually of a VLDL nature. These lipoproteins are not associated with the Lp(a) lipoprotein.

Antigens↗
PubMed1975

Lp(a) lipoprotein/pre-beta1-lipoprotein in Swedish middle-aged males and in patients with coronary heart disease.

A strong, positive association (P smaller than 0.0001) was found between the presence in serum of pre-beta1-lipoprotein upon electrophoresis in 0.5% agarose and the Lp(a+) phenotype in a series of 103 males aged 50-52 years participating in a health control study and in a series of 58 patients with sustained myocardial infarction. Both lipiprotein phenomena were more prevalent in the 58 patients than in the 103 presumably healthy males. The lack of any significant difference between total cholesterol values in the patients and the controls, despite the higher frequency of phenotype Lp(a+) in the former group, argues against the suggestion by Walton et al. (1974) that the increased Lp(a+) frequency in patients with coronary artery disease may be caused by a general increase in the concentration of low density lipoproteins (LDL).

Cholesterol↗
PubMed1975

Further studies of Lp(a) lipoprotein/pre- beta1-lipoprotein in patients with coronary heart disease.

The present study of 100 patients (46 of whom were included in a previous study) with suspected or proven coronary heart disease (CHD) confirms that Lp(a) lipoprotein and pre-beta1-lipoprotein are closely related, if not identical, and that Lp(a) lipoprotein/pre-beta-lipoprotein occurs more frequently in patients with CHD than in healthy people. Analysis of this lipoprotein component may have predictive value with respect to CHD.

Adult↗
PubMed1975

ADA-7--a new allele.

A new ADA phenotype which is particularly susceptible to phenotypic changes following storage was observed. Family studies indicate that this type may be due to a new allele, ADA-7. The phenotype observed was classified as ADA 7-1.

Adenosine Deaminase↗
PubMed1975

Affinity chromatography of human leukocyte and diploid cell interferons on sepharose-bound antibodies.

Interferons produced in human peripheral leukocytes (LE) and foreskin fibroblast (FS-4) cells were subjected to affinity chromatography on Sepharose-bound globulins from rabbits immunized with these interferons. Anti-LE interferon sera neutralized both interferons, but titers against FS-4 interferon were consistently lower than those against LE interferon. Anti-FS-4 interferon sera neutralized only FS-4 but not LE interferon. Accordingly, affinity columns constructed with anti-FS-4 globulin excluded LE but not FS-4 interferon, whereas those prepared with anti-LE interferon globulin bound and eluted both LE and FS-4 interferons. Purification of native interferons of both types on anti-LE interferon-Sepharose ranged from 680- to 3,600-fold and recoveries from 72 to 126%. Specific activities of eluate pools varied from 4 to 30 times 10-6 reference (B, 69/19) units per milligram protien.

Animals↗