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Biomedical subjects

H Bohn

Publications and source records attributed to H Bohn.

At least 109 records · Page 6Linked to original sources
PubMed1982

Radioimmunoassay of placental protein 12: levels in amniotic fluid, cord blood, and serum of healthy adults, pregnant women, and patients with trophoblastic disease.

A radioimmunoassay for placental protein 12 (PP12) is described and the levels in amniotic fluid, cord blood, and serum of nonpregnant individuals, pregnant women, and patients with trophoblastic disease are presented. During pregnancy, the highest PP12 levels were found at 22 to 23 weeks (mean +/- SD, 169 +/- 123 ng/ml), and there was a transient decline at 32 to 33 weeks (63 +/- 23 ng/ml). In amniotic fluid, the levels were 100 to 1,000 times higher than in maternal serum. In cord blood at birth, the values were of the same magnitude as in maternal serum. Also healthy nonpregnant women and men had PP12-like immunoreactivity in serum. Nonpregnant women (9 to 47 ng/ml) had higher levels than men (undetectable to 21 ng/ml). Elevated levels up to 84 ng/ml were occasionally observed in trophoblastic disease, both hydatidiform mole and choriocarcinoma, but they bore no correlation with the human chorionic gonadotropin levels. On the basis of these results PP12 is not a suitable marker for trophoblastic disease. PP12 values in normal pregnancy provide the basis for the evaluation of PP12 levels in abnormal pregnancy.

Adult↗
PubMed1982

Placental protein 5 is related to blood coagulation and fibrinolytic systems.

Previous studies have shown that placental protein 5 (PP5) forms complexes with heparin. In order to further elucidate the biological role of PP5 we studied the effect of plasmin and thrombin on the immunoreactivity of PP5, and the possible functional antiplasmin and antithrombin effects of purified PP5. Varying concentrations of plasmin and thrombin were added to pregnancy plasma, and the PP5 levels, measured by radioimmunoassay, were found to be elevated by 558% (plasmin and 48-87% (thrombin). Incubation of radiolabeled PP5 with plasmin resulted in the formation of radioactive fragments with smaller molecular weights. Functional studies using a chromogenic substrate confirmed that purified PP5 has an antiplasmin activity. An average increase of 15% was observed in the antiplasmin activity when 200 ng purified PP5 was added to 150 microliters of pregnancy serum. Thus, there are certain similarities between PP5 and antihrombin III. Both form complexes with heparin and have antiplasmin properties, and both were found to be heat labile. But, functional studies utilizing a chromogenic substrate failed to demonstrate any antithrombin III-like activity in the purified PP5 preparation that had antiplasmin activity. Our results show that the function of PP5 is related to the blood coagulation and fibrinolytic systems, at least through its inhibitory action on plasmin.

Antithrombin III↗
PubMed1982

Placental protein 5 (PP5) in pregnancy and malignant disease: the influence of heparin binding.

The molecular mass of immunoreactive placental protein 5 (PP5) in late pregnancy blood was studied by gel filtration. The predominant form of PP5 in serum was of molecular mass 37000, whereas in heparinised plasma the molecular mass ranged upwards from 50000, with the majority of material in high molecular mass forms, thought to arise by binding of PP5 to heparin. The effect of heparin on PP5 measurements appeared to be enhanced by a serum component related to pregnancy, since addition of heparin decreased the measured level of PP5 to a greater extent in pregnancy serum than in male serum to which purified PP5 had been added. The radioimmunoassay dose-response curve was shallower for PP5 in heparinised plasma than for purified PP5 and PP5 in serum, and this may explain previous low measurements and high recoveries after chromatography. PP5 produced by a hydatidiform mole behaved in a similar manner to the placental form; PP5 form a malignant breast tumour cytosol preparation did not.

Chromatography, Gel↗
PubMed1982

Monitoring therapy in trophoblastic diseases by radioimmunoassay of pregnancy-specific beta 1-glycoprotein and the beta subunit of human chorionic gonadotropin.

The beta-subunit of human chorionic gonadotrophin (hCG) and pregnancy-specific beta 1-glycoprotein (SP1) were measured simultaneously by specific radioimmunoassays in 473 serum samples from 43 patients with trophoblastic tumors. Both SP1 and hCG values were high in 16 untreated patients. 27 patients had been treated previously elsewhere, and their further treatment and monitoring were started simultaneously in our institute. Raised SP2 and hCG levels were found in 22 and 21 cases, respectively. Treatment was followed by a parallel decrease of both SP1 and hCG, but the hCG decline was more marked. Seronegativity was reached only after several months; SP1 was present in the serum for 60-150 days, and hCG could be found even after this time. Both parameters were sensitive indicators of residual tumor activity, calling for further therapy months before any clinical manifestation of recurrence. In three cases only one of the tumor makers could be found, which underlines the importance of the simultaneous measurement of hCG and SP1.

Choriocarcinoma↗
PubMed1982

Immunohistochemical detection of pregnancy-specific protein (SP1) and placenta-specific tissue proteins (PP5, PP10, PP11 and PP12) in ovarian adenocarcinomas.

By using an immunoglobulin-enzyme bridge method, pregnancy-specific beta 1-glycoprotein (SP1) and placenta-specific tissue proteins (PP5, PP10, PP11, PP12) were investigated in 15 cases of mucinous cystadenocarcinoma and 20 cases of serous cystadenocarcinoma. These proteins could be detected in the cytoplasm of some malignant cells. In mucinous cystadenocarcinomas, SP1, was present in 53.3% of cases, PP5 in 80.0%, PP10 in 20.0%, PP11 in 66.7% and PP12 in 46.7%. In serous cystadenocarcinomas, SP1 was present in 35.0% of cases, PP5 in 76.2%, PP10 in 9.5%, PP11 in 57.1% and PP12 in 23.8%. No proteins were detected in five normal ovaries. All control sections incubated with phosphate-buffered saline or normal, non-pregnant, non-immune rabbit serum in place of the first specific antiserum as well as with the antisera exhaustively absorbed with the corresponding purified antigens were negative for each protein. The detection rates are discussed in relation to the clinical stages and survival rates of the patients. This study suggests that these proteins, especially PP5 and PP11, may be useful as markers in monitoring patients with ovarian adenocarcinomas as well as for their early diagnosis.

Cystadenocarcinoma↗
PubMed1982

Placental protein 5 (PP5)-like immunoreactivity in human urine.

Placental protein 5 (PP5)-like immunoreactive material was detected in human male urine in small concentrations (17-60 pg/ml). Part of the PP5 immunoreactivity in the urine had a molecular weight of 36 000-42 500, which is the molecular weight of purified PP5 from the human placenta. In radioimmunoassay, serial dilutions of the 36 000-42 500 molecular weight material gave an inhibition curve parallel to that of the PP5 standard. The source of PP5-like immunoreactivity in the urine is not known. It may be related to urokinase, which coeluted with PP5-immunoreactive material in gel filtration.

Chromatography, Gel↗
PubMed1981

Placental proteins (SP1, hCG, PP5) and alpha 2-PAG in trophoblastic diseases.

455 serial serum samples from 41 patients with trophoblastic tumour were analysed. Pregnancy-specific beta-1 glycoprotein (SP1), human chorionic gonadotropin (hCG), and placental protein 5 (PP5) were measured by specific radioimmunoassay. Pregnancy-associated alpha 2-glycoprotein (alpha 2-PAG) was measured by electroimmunoassay. SP1 and hCG levels were high in 36 and 35 patients respectively; alpha 2-PAG concentration was also high in 29 patients. PP5 was found only in patients with a hydatidiform mole and it disappeared from serum within a few hours of evacuation. SP1 and hCG levels decreased during the course of the treatment but seronegativity was reached only after some months: hCG was still detectable after that and disappeared from the serum more slowly. Both parameters were sensitive indicators of residual tumour activity and indicated the need more effective treatment some months before clinical manifestations of recurrence became evident. In some patients only one of the tumour markers was present during follow-up, indicating the importance of careful monitoring including the measurement of serum SP1 and hCG levels. A positive correlation between alpha 2-PAG and hCG, SP1 and the clinical course was found only in 80% of patients a finding which demonstrates the limited value of alpha 2-PAG measurements.

Choriocarcinoma↗
PubMed1981

Ectopic production of placenta-"specific" tissue proteins (PP5 and PP11) by malignant breast tumors.

With use of an enzyme-bridge immunoperoxidase (PAP) technique, an immunohistochemical localization of the two new placenta-"specific" tissue proteins, PP5 and PP11, was investigated in 16 cases of breast cancer. PP5 was localized in the cytoplasm of breast cancer cells in 62.5% of cases examined and PP11, in 46.7%. Thus PP5 and PP11 may be markers for breast cancer and the detection of these proteins in sera from breast cancer patients may be more reliable and useful in the detection and monitoring of breast cancer patients than the determination of SP1, PP10, or PP12, other pregnancy "specific" proteins.

Breast Neoplasms↗
PubMed1981

Immunohistochemical location of proteins related to pregnancy-specific beta 1-glycoprotein (SP1) and placental tissue proteins (PP5, PP8, PP9, PP10, PP11, PP12) in the afterbirth of Cynomolgus monkeys (Macaca fascicularis).

The occurrence and location of proteins antigenically related to human pregnancy specific beta 1-glycoprotein (SP1) and to human placental tissue proteins (PP5, PP8, PP9, PP10, PP11, PP12) were studied in the afterbirth (placenta, membranes, decidua, and umbilical cord) of cynomolgus monkeys with use of an immunoglobulin enzyme bridge (PAP) technique. The results were basically the same throughout pregnancy. The syncytiotrophoblast of villi showed clear positive stainings for SP1, PP8, PP9, and PP11, whereas the cytotrophoblast (villi) was found to show clear positive staining for PP9 only. The main sources of proteins related to SP1, PP9, and PP11 were the syncytiotrophoblast cells of the villi and PP8, the syncytiotrophoblast cells of villi as well as the chorionic trophoblast cells. PP12 was mainly located in histiocytes found in the decidua, umbilical cord, amnion, and chorion. There were only traces of PP5 and PP10 in the placentae of cynomolgus monkeys throughout gestation. As in human placentae some granulocyte-like blood cells in the intervillous space were strongly positive for PP8, PP10, and PP12. The findings in the afterbirth of cynomolgus monkeys were similar to those in the human; the monkey could thus serve as a model for the investigation of the new placental proteins.

Animals↗
PubMed1981

The effect of protamine on serum levels of placental protein 5 (PP5) in normal and abnormal pregnancy: a possible relation to coagulation abnormalities.

The levels of placental protein 5 (PP5) in pregnancy serum show an apparent increase after the addition of protamine sulphate. The difference of the apparent concentrations of serum PP5 in the presence and absence of protamine (delta PP5) was determined in 345 normal and abnormal pregnancies. A positive delta PP5 was less frequent in diabetic pregnancy (45 per cent) and pre-eclampsia (57 per cent) than in normal pregnancy (80 per cent). These findings provide further evidence that PP5 may be involved in the coagulation system, and in particular may relate to abnormal coagulation processes at the placental site.

Blood Coagulation↗
PubMed1981

Placental protein 5 (PP5): development of a radioimmunoassay and measurement of circulating levels in normal pregnancy.

A specific and sensitive, double antibody, solid phase radioimmunoassay was developed for measurement of placental protein 5 (PP5) in serum. A sensitivity limit of 0.8 microgram/1 was achieved by pre-incubation with antiserum and use of a small assay volume. Single serum samples from 244 retrospectively proven normal pregnancies were used to construct a normal range of PP5 concentrations. PP5 was detectable at week 7 and rose to reach a maximum mean value of 54 microgram/1 at weeks 36-37. Diurnal variation of PP5 concentration was similar to that encountered from day to day, and slightly greater than variation due to the radioimmunoassay. The decline of serum PP5 concentration post partum was initially rapid (half-life 5-14 minutes), but slowed after 0.5-1 hours; immunoreactive PP5 was still detectable seven days after delivery.

Circadian Rhythm↗
PubMed1981

Placental protein 5 (PP5) in complicated pregnancies.

Maternal serum PP5 concentrations were assayed in pregnancies complicated by intrauterine growth retardation, pre-eclampsia, diabetes mellitus, placental abruption and twins. Elevated PP5 levels were noted in twin pregnancies and to a lesser extent in diabetes and pre-eclampsia. Measurement of PP5 was of no value in the detection of fetal growth retardation. The great majority of PP5 levels above the normal range were associated with a placental abnormality.

Abruptio Placentae↗
PubMed1981

Cultured human syncytiotrophoblasts synthesize pregnancy-specific beta-1-glycoprotein (SP1).

The synthesis of pregnancy-specific beta-1-glycoprotein (SP1) was studied in human syncytiotrophoblast cultures from first trimester placentas. Incorporation of 35S-methionine into SP1 was demonstrated by immunoprecipitation and polyacrylamide gel electrophoresis. In double diffusion the precipitation line of neosynthesized SP1 gave a reaction of complete immunological identity with maternal serum SP1. By indirect immunofluorescence intracellular SP1 was localised in the perinuclear region of the cells. The average rate of SP1 release into culture fluid was 600 ng/mg protein in 24 hours. On a molar basis the release of SP1 was 10 times less than that of human chorionic gonadotrophin (hCG). Our results demonstrate, for the first time, that cultured human syncytiotrophoblasts synthesis SP1 immunologically indistinguishable from placental SP1.

Cells, Cultured↗
PubMed1981

Possible synthesis of pregnancy-'specific' beta-1-glycoprotein (sp1) and placenta-'specific' tissue proteins (PP10,PP12) by human and cynomolgus monkey leukocytes.

Using an enzyme-bridge immunoperoxidase (PAP) technique, it was revealed that pregnancy- and/or placenta-specific proteins, SP1, PP10 and PP12 were localized in human and cynomolgus monkey (Macaca fascicularis) polymorphonuclear neutrophils, and PP10, in mononuclear phagocytes. There was no difference in staining results, irrespective of whether the specimens were from human or monkey males, or pregnant or nonpregnant females. The results suggest that SP1, PP10 and PP12 may be synthesized by polymorphonuclear neutrophils and/or mononuclear phagocytes and could represent markers not only for trophoblasts and some kinds of malignant neoplasms but also for normal neutrophils and/or monocytes.

Animals↗
PubMed1981

Human seminal plasma contains a protein that shares physicochemical and immunochemical properties with placental protein 5 from the human placenta.

Placental protein 5 (PP5)-like immunoreactive material was detected in human seminal plasma at high concentrations (32-1000 ng/ml). This was not due to interference with proteases or binding to seminal plasma proteins, since immunoreactivity was not affected by treatment with protease inhibitors, and incubation with seminal plasma of [125I]PP5 did not bring about any significant change in the elution pattern in gel filtration. Part of the PP5 immunoreactivity in seminal plasma had a molecular weight of 36,000-42,500 which is the molecular weight of purified PP5 from the human placenta. In RIa, serial dilutions of the 36,000-42,500 molecular weight material gave an inhibition curve parallel to that of the PP5 standard. The source of seminal plasma PP5-like material is not from the testes, as the levels in vasectomized men were similar to those in nonvasectomized men.

Chromatography, Gel↗