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Biomedical subjects

H Bohn

Publications and source records attributed to H Bohn.

At least 127 records · Page 7Linked to original sources
PubMed1981

Radioimmunoassay of SP1 (pregnancy-specific beta1-glycoprotein) in maternal blood and in amniotic fluid normal and pathologic pregnancies.

Sp1, the pregnancy-specific beta 1-glycoprotein, was studied in normal and pathologic pregnancies. We developed a highly specific and sensitive double-antibody-radioimmunoassay by radioiodination of purified placental SP1. This RIA allowed the estimation of SP1 concentrations as low as 2 ng/ml. In a collective of 227 women with normal pregnancies we established the normal distribution curve in maternal plasma from the fifth week of gestation to term. The median value rose steadily from 3 microgram/ml in the 8th week to 140 microgram/ml in the 36th week when a plateau was formed. In more than 400 patients with pregnancies complicated by a variety of pathologic disorders the SP1 levels were controlled by either single assays or serial estimations throughout pregnancy and were compared with the normal distribution range. SP1 was also determined in about 200 samples of amniotic fluid gained by amniocentesis and during parturition of normal pregnant women from the 13th gestational week until term. The normal range was established up to the 20th w.o.p. The concentrations rose from below 0.2 microgram/ml in early pregnancy to 3 microgram/ml and generally amounted to approximately 1% of the respective serum value. Pathologic cases with diverse chromosomal anomalies, Rh-incompatibility, anencephaly, hydramnios and other abnormal conditions were examined. From these only twin-pregnancies with slightly elevated levels and cases with fetal trisomies with reduced SP1 concentrations showed aberrations from the normal distribution. The estimation of serum concentrations in mothers with diabetes or Rh-incompatibility were not significantly different from the normal collective. In diabetes a characteristic course of the follow-up curves was observed. Abortion in early pregnancy was frequently but not always indicated by reduced SP1 values. Threatened abortion with subsequent continuation of pregnancy exhibited SP1 values scattered within the normal range. Since the radioimmunological determination of SP1 is possible in the early stage of gestation (from week 8) it may serve as a useful tool for prediction at times when the determination of placental lactogen is not yet possible. In pregnancies with "small-for-date babies" the correlation between SP1 in maternal plasma and fetal growth retardation was reflected in a pronounced tendency to low SP1 levels. Serial determinations of SP1 in the serum of women with EPH-gestosis were compared with the corresponding HPL determinations and showed the equality of SP1 concerning the assessment of the placental function.

Amniocentesis↗
PubMed1981

New placental proteins and their potential diagnostic significance as tumour markers.

Five new soluble placental tissue proteins (PP8, PP9,, PP10, PP11 and PP12) have been isolated, purified and characterized. PP, has the electrophoretic mobility of a beta 1-globulin; the other 4 proteins are alpha 1-globulins. The molecular weights of these proteins range from 25 000--65 000 daltons. They all are glycoproteins with carbohydrate contents ranging from 3.9--6.6%. The amino acid compositions of these proteins also have been determined. PP8 and PP, are ubiquitous tissue proteins in that they occur in relatively high concentrations in almost all human tissues examined. PP10, PP11 and PP12 could not be detected in extracts of other human tissues and, therefore, were supposed to be specific to the placenta. PP10--12 was shown to be present in tumour tissues by an immunoglobulin enzyme bridge (PAP) technique. The results suggest that these proteins may be useful as markers in oncology.

Animals↗
PubMed1981

Detection of placental protein five (PP5) and pregnancy-specific glycoprotein (SP1) in benign and malignant breast disease.

Sensitive radioimmunoassays for the placental proteins PP5 and SP1 were used to investigate possible ectopic synthesis of these proteins by breast tumors. Elevated serum levels of the proteins were found in a small proportion of patients who had undergone mastectomy for malignant tumors, but little useful information on tumor spread could be gained from such measurements. In two patients with elevated pre-operative serum PP5, the levels fell to normal upon resection of the tumor, suggesting that PP5 may be a product of the tumor. PP5 and SP1 were found to be present in the majority of homogenates of malignant and benign breast lesions; the highest concentrations of SP1 were found in malignant tumors, whereas with PP5, especially high levels were found in cases of simple cystic disease.

Adenofibroma↗
PubMed1980

Ectopic synthesis of pregnancy specific beta 1-glycoprotein (SP1) and placental specific tissue proteins (PP5, PP10, PP11, PP12) in nontrophoblastic malignant tumours. Possible markers in oncology.

By using an enzyme-bridge immunoperoxidase (PAP) technique, localization of so-called pregnancy-specific beta 1-glycoprotein (SP1) and placental-specific tissue proteins (PP5, PP10, PP11, PP12) was investigated in 19 cases of breast cancer, 24 cases of testicular malignant tumours, 12 cases of gastric cancer and some cases of other malignant tumours. These five glycoproteins isolated from human term placentae and characterized by Bohn are localised mainly in the cytoplasm, or nucleus of syncytiotrophoblast and appear to be specific for the trophoblast. But to a certain percentage these proteins could also be detected in the cytoplasma of malignant cells: In breast cancer, SP1 was present in 52.6% of cases, PP5 in 63.2%, PP10 in 68.4%, PP11 in 55.6% and PP12 in 31.6%. In testicular malignant tumours the detection rates of these proteins varied from 20.8 to 75.0% and in gastric cancer from 41.7 to 66.7%. In total 50% of the tumours tested were SP1-positive, 58.3% PP5-positive, 55.6% PP10-positive, 38.0% PP11-positive and 31.9% PP12-positive. In addition, it was found that mononuclear histiocytes showed a strong cytoplasmic staining for PP10 and PP12 and that a few other non-cancerous cells (i.e. striated cells in gastric metaplasia, gastric polyps etc.) stained for PP5, PP10, PP11 and/or PP12. All control sections were negative in malignant cells as well as in other tissue cells. This study confirms the reports that some kinds of malignant tumours produce SP1 and indicates that the ectopic production of proteins normally produced by the trophoblast is a common finding in malignant tumours. It furthermore suggests that such proteins may be useful as markers in monitoring patients with malignant diseases. The possible mechanisms of ectopic production of these inappropriate proteins in malignant tumours are discussed.

Breast Neoplasms↗
PubMed1980

New placental and pregnancy proteins as possible markers in oncology.

A number of placental and pregnancy proteins has been detected by immunochemical methods in extracts from human term placentae. Several of these proteins already have been isolated and characterized and are now investigated for their usefulness as markers in oncology. Several of these proteins so long tested appear to be useful as markers in monitoring tumour patients, i.e. in the early detection of tumour recurrence or metastases and in the control of therapy. In addition, we hope that a combination of several of these new markers with already established tumour markers will enable to better diagnose tumours. Also will the use of solitary tissue proteins aid in the differential diagnosis of cancers.

Diagnosis, Differential↗
PubMed1980

Immunohistochemical location of placental proteins (PP8, 9, 10, 11, 12) in human term placentae.

By using an immunoglobulin enzyme bridge (PAP) technique, the location of two ubiquitous tissue proteins (PP8, PP9) and three placental specific tissue proteins (PP10, PP11, PP12) was investigated in ethanol/acetic acid-fixed paraffin-embedded human term placentae. PP8 was found mainly in both the cytoplasm and the nucleus of trophoblast cells (chorion) and syncytiotrophoblast (villi). PP9 was found in the cytoplasm of trophoblast cells (chorion), the fibrous part of interstitial connective tissues (villi), and the cytoplasm of histiocytes (villi, amnion, and decidua). PP10 was found in the cytoplasm of epithelium (amnion) and in both the cytoplasm and the nucleus of syncytiotrophoblast (villi). PP12 was found in the cytoplasm of histiocytes in decidua, amnion, and chorion and the cytoplasm of syncytiotrophoblast (villi). In addition, stains for PP8, PP10, and PP12 were taken up by the cytoplasm of histiocytes found in amnion, villi, the intervillous space, and decidua, in contrast to PP11, which was found to be specific to the cytoplasm of trophoblast cells (chorion and villi). Possible clinical applications of these findings are discussed.

Cell Nucleus↗
PubMed1980

[New placental protein (PP15) with immunosuppressive properties (author's transl)].

The isolation and characterization of a new placental protein (PP15) which has immunosuppressive properties are described. The protein was purified from extracts of human term placentae by rivanol and ammonium sulfate fractionation, gel filtration, ion exchange chromatography, preparative zone electrophoresis, and chromatography on hydroxyapatite. PP15 was found to have a sedimentation coèfficient of 2.9 S and a molecular weight of 30,700 daltons as determined by ultracentrifugation; its molecules apparently are composed of two identical subunits which are held together by non-covalent bonds. The electrophorectic mobility of PP15 corresponds to that of albumin. PP15 is a glycoprotein and contains 3.3% carbohydrates (hexoses 2.8%, hexosamines 0.3%, sialic acid 0.2%). The amino acid composition of this protein was also determined: the most abundant amino acids in the peptide chain were found to be glutamic acid, aspartic acid, isoleucine, and leucine. PP15 has immunosuprressive properties: on testing its effect on the lymphoycte transformation in the MLC-test in vitro a significant inhibitory activity could be demonstrated.

Aspartic Acid↗
PubMed1979

The radioimmunoassay of placental protein 5 and circulating levels in maternal blood in the third trimester of normal pregnancy.

A radioimmunoassay has been developed for placental protein 5 (PP5), a product of the human placenta. Circulating concentrations of PP5 were measured in the third trimester of normal pregnancy in 400 women. Concentrations of PP5 showed a skewed distribution and rose progressively to reach a plateau in the last four weeks of pregnancy. The development of this assay will permit studies on the potential clinical application of maternal PP5 levels during normal and abnormal pregnancy.

Cross Reactions↗
PubMed1979

[Isolation and characterization of a new placenta specific protein (PP10) (author's transl)].

PP10 was isolated from aqueous extracts of human term placentae by fractionating the proteins with rivanol and ammonium sulfate, by gelfiltration on Sephadex G-150 and by use of immunoadsorbents. PP10 apparently is a protein specific for the placenta; it could not be detected in extracts from other human tissues. From one human term placenta an average amount of 20 mg PP10 can be extracted. In sera from pregnant women PP10 is usually present only in trace amounts (less than 0.1 mg/100 ml). PP10 has the electrophoretic mobility of an alpha1-globulin and an isoelectric point of 5.1. The purified protein sediments with 3.8 S. PP10 was found to have a molecular weight of 48,000 as determined by ultracentrifugation and a molecular weight of 65,000 as determined by SDS-PAA gel electrophoresis. PP10 is a glycoprotein containing 6.65% carbohydrates (hexoses 4.8%, hexosamines 1.2%, fucose 0.05%, sialic acid 0.6%). The amino acid composition of PP10 has been determined, too; the most abundant amino acids in this protein are glutamic acid, aspartic acid, leucine and alanine.

Electrophoresis↗
PubMed1978

The value of pregnancy-associated alpha2-glycoprotein in patients with colorectal cancer.

Serum pregnancy-associated alpha2-glycoprotein (alpha2PAG) levels have been measured in 67 patients with colorectal cancer. Postoperative changes in alpha2PAG concentrations were observed in patients undergoing apparently curative surgery and compared with results in patients with residual local or metastatic tumour. Significant increase in alpha2PAG levels were found only in those patients with residual or disseminated tumour. In this study alpha2PAG levels closely paralleled the clinical course of the disease in many patients.

Adult↗