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Biomedical subjects

T Stigbrand

Publications and source records attributed to T Stigbrand.

At least 199 records · Page 11Linked to original sources
PubMed1978

Immunosuppressive effect of human pregnancy zone protein on H-2 incompatible mouse heart allografts.

Human pregnancy zone protein (PZP) given intraveneously, significantly (p less than 0.001) prolonged the survival of heterotopic A/J heart transplants in A.CA recipients, compared to untreated control recipients, recipients treated with phosphate buffered saline and recipients treated with a control preparation from male serum. The results support the hypothesis that PZP protein exerts an unspecific immunosuppressive effect in vivo.

Animals↗
PubMed1978

Purification of the pregnancy zone protein by affinity chromatography.

A method for purification of the pregnancy zone protein (PZP) by affinity chromatography was developed. A monospecific immunoglobulin fraction, covalently coupled to Sepharose 4B, was used as binding agent and the elution conditions for PZP are described. The purified protein was shown to have identical properties compared to native PZP with regard to molecular weight, immunodiffusion precipitation and immunosuppressive activity.

Alpha-Globulins↗
PubMed1978

Prognostic value of the pregnancy zone protein during early pregnancy in spontaneous abortion.

The concentration of pregnancy zone (PZ) protein in maternal serum during early normal pregnancy was followed in a prospective study of 261 pregnant women. A marked increase which followed an exponential function was found and a theoretic onset of induction at the time for implantation was calculated. Women with a later spontaneous abortion had low values. The prognostic relevance of PZ determinations was studied and values from women who later had a spontaneous abortion were compared to those from normal pregnancies. The prognostic value of PZ protein was compared to that of hCG and progesterone. PZ and hCG assays had the same prognostic accuracy concerning the outcome of pregnancy while determinations of progesterone were less valuable.

Abortion, Spontaneous↗
PubMed1977

Purification and partial characterization of the I variant of placental alkaline phosphatase.

The I variant of placental alkaline phosphatase was purified to homogeneity by means of DEAE-cellulose chromatography, isoelectric focusing, and gel filtration on AcA-34. The specific activity of the I variant was found to be 3.33 micronkat/mg. The enzyme is a dimer with an isoelectric point of 4.6 and a molecular weight of 120,000 as determined by sodium dodecylsulfate electrophoresis. The amino acid composition and other physiocochemical properties of the I variant were compared with those of the more common F and S variants. The low activity associated with the I variant is apparently not due to a low specific activity, but to decreased molecular stability. The behavior in the ultracentrifuge and other observations suggest that the I variant differs from the F and S variants in surface charge distribution.

Alkaline Phosphatase↗
PubMed1977

The immunological paradox of pregnancy.

During a normal pregnancy the fetus can be regarded as a transplant inside the uterus. The reason why this transplant is not rejected is still unclear. In this work various models for this immunological paradox and recent results within the field of pregnancy immunology are discussed. From an immunological point of view the development of a normal pregnancy is almost impossible. During all stages the embryo can be regarded as a transplant (4), but instead of the expected rejection an intimate parasitic graft - host relationship is established. The sperm has already been shown to be the carrier of transplantation antigens and thus theoretically capable of initiating an immune response. The fertilized egg also carries transplantation antigens on its surface after the first division. Foreign transplantation antigens release in the receiver a cell mediated immune reaction, which normally causes a rejection within some weeks.

Animals↗
PubMed1977

Basic levels of the immuno suppressive serum protein PZ in women-influence of age, parity, gonadotrophins and estrogens.

The basic levels of the pregnancy zone protein (PZ) were measured by a radio-immunoassay, in 270 women of various age. All women were apparently healthy taking no drugs. Values were correlated to age, parity, gonadotrophins and estrogens. A significant age dependent increase was found for PZ while no influence could be attributed to the other factors studied. The present results emphasize that the age dependent variation of PZ concentration should be considered when clinical data of this protein are evaluated.

Adolescent↗
PubMed1977

Increased serum levels of the pregnancy zone protein in psoriasis.

On the basis of immunological studies on psoriasis in recent years, it seems probable that immunological mechanisms are of importance and that psoriasis could be regarded as an immunogenetic disease. In this study, increased serum levels of an immunosuppressive factor, the pregnancy zone protein (PZ), were found in psoriatic patients. Patients with elevated levels (greater than 2 S.D. units) of PZ showed a positive association with continuous symptoms and a negative association with blood groups A and Fy(a+b-). Thus, induction of PZ occurs mainly in psoriatic patients who have a particular genetic constitution. The results support the hypothesis that PZ is not only an immunosuppressive but also an immunoreactive protein.

Adolescent↗
PubMed1976

On the occurrence of the pregnancy zone protein (PZ) in gynecological cancer.

Reports have been made that the pregnancy zone protein (PZ) is found in increased amounts in sera of patients with malignant disease. The serum concentration of PZ was measured by a radioimmunoassay in 83 women with the diagnosis of gynaecological cancer or other malignancies. Values did not significantly differ from values previously recorded in apparently healthy women. There was no support for previous data of increased levels of PZ in cancer patients, when the age-dependent increase of this serum factor was considered.

Adolescent↗
PubMed1976

A comparison between the common type and a rare genetic variant of human cupro-zinc superoxide dismutase.

Human cupro-zinc superoxide dismutase is polymorphic in northern Sweden. The genetic variant type has a lower mobility at electrophoresis in alkaline buffer. The enzyme was isolated from erythrocytes from one of the rare homozygotes and its properties compared to those of the common type. The isoelectric point of the variant was higher (4.85) than that of the common type (4.7). Small differences in amino acid composition were found but no definite amino acid substitutions could be pointed out. The molecular weights were equal as judged from electrophoreses in polyacrylamide gels in the presence of dodecylsulphate. The ultraviolet spectra were similar. Parameters related to the active site of the enzyme were very similar; i.e. specific activity and sensitivity to inhibition by cyanide and by H2O2. These parameters, especially the latter two, differ widely between species. Both enzymes were stable for weeks at neutral pH at 37 degrees C, whereas the common type was significantly more stable at pH 4 and pH 11 and also at incubation in neutral buffer at 70 degrees C. It appears that the active site of the variant is conserved whereas the stability of the enzyme is affected.

Amino Acids↗
PubMed1976

A quantitative study of the pregnancy zone protein in sera of woman taking oral contraceptives.

By means of a single radial immunodiffusion the concentration of "the pregnancy zone protein" (PZ) was measured in sera from women taking oral contraceptive drugs. Woman taking only 0.3 mg. of norethisterone were found not to induce measurable amounts of PZ, whereas women taking combined contraceptive drugs showed a significant rise in concentration of PZ. After six months' treatment, 1 mg. of norethisterone and 0.1 mg. of meastranol daily were found to give an average concentration of PZ amounting to 59 mg. per 100 ml., that is, approximately half of the concentration of PZ in sera from women during the last trimester of pregnancy. Different combined contraceptive pills gave rise to different concentrations of PZ.

Contraceptives, Oral↗
PubMed1976

Purification and parital characterization of two genetic variants of placental alkaline phosphatase.

The two most common variants of placental alkaline phosphatase, the F and S variants, were purified to homogeneity and characterized. Their molecular weights were determined by equilibrium ultracentrifugation and sodium dodecylsufate polyacrylamide gel electrophoresis, which gave almost identical values for the two variants, 118,000 (F) and 119,000 (S). The amino acid compositions of F and S variants presented here are found to be very similar. Differences between the two variants were found in specific activity (160 U/mg for F and 250 U/mg for S), isoelectric point (IP - 4.5 for F and 4.7 for S), sedimentation coefficient (6.5 X 10(-13) sec for F and 6.4 X 10(-13) sec for S). Thus the structural differences observed for these enzyme variants seem to affect both the active site and the protein conformation.

Alkaline Phosphatase↗
PubMed1976

Demonstration of analogues to the human pregnancy zone protein in animals.

The pregnancy zone protein (PZ) is known to occur in increased amounts during pregnancy and hormonal treatment. Analogues of this human serum alpha2-globulin were demonstrated in animals by double gel diffusion and immunoelectrophoresis. Direct cross-reactions were found for Rhesus monkey and beagle dog against anti-human pregnancy zone protein. After preparation of an "anti-dog PZ" serum it was possible to demonstrate analogues also in cow and sheep. Thus, the present investigation demonstrated animal analogues to the human pregnancy zone protein, which should be valuable for studies of the biological role of this protein.

Alpha-Globulins↗