Search PubMed⌕ Search

Biomedical subjects

H Bohn

Publications and source records attributed to H Bohn.

At least 73 records · Page 4Linked to original sources
PubMed1987

Oncoplacental protein SP1--a constitutive and inducible late differentiation marker of the human myelomonocytic lineage.

The oncoplacental protein SP1 is found in large quantities in human placenta, amniotic fluid, and pregnancy serum. Low levels have been reported in association with malignancy but also in healthy nonpregnant individuals. By indirect immunofluorescence, fluorescence-activated cell sorting, and immunoprecipitation we here demonstrate the presence of SP1 both on the surface and in the cytoplasm of human granulocytes but not in earlier myeloid progenitor cells in bone marrow. Lymphocytes did not contain the protein, and only trace amounts could be found in the cytoplasm of blood monocytes. A major glycoprotein with an apparent mol wt of 90,000 was obtained by immunoprecipitation of surface-labeled granulocytes. Cultivated blood monocytes, while adhering to surfaces or forming multinuclear giant cells, displayed a strong membrane and cytoplasmic expression of SP1. Treatment of the myeloid leukemia cell line ML-2 with tetraphorbol acetate (TPA) strongly induced SP1 in the membrane and cytoplasm as revealed by immunofluorescence and polyacrylamide gel electrophoresis (PAGE) of immunoprecipitates from lysates of surface radiolabeled cells. The induction of synthesis of SP1 in TPA-treated cells was confirmed by immunoprecipitation from lysates of cells metabolically labeled with 35S-methionine. Human lymphoblastoid and erythroleukemic cell lines did not express SP1 either before or after induced differentiation. Thus SP1 provides a late differentiation marker for the myelomonocytic lineage and is strongly induced during macrophage differentiation or by TPA treatment of ML-2 cells.

Cell Differentiation↗
PubMed1986

Biologically active domain in somatomedin-binding protein.

We have found that human decidua synthesizes a 34K somatomedin-binding protein PP12. Purification of PP12 by immunochemical techniques from human placenta and adjacent membranes has also yielded lower-molecular weight immunoreactive polypeptides designated as PP12B. An individual 21K fragment of somatomedin-binding protein, and a mixture of fragments with molecular weight from 17K to 20K were isolated from this material using high performance liquid chromatography (HPLC). These fragments reacted with antibodies to native PP12 as shown by Western blotting. They all shared the same N-terminal amino acid sequence: Ala-Pro-Trp-Gln-, which is identical with that obtained for PP12. The 21K fragment was shown to bind somatomedin-C, or IGF-I (insulin-like growth factor-I). Since the N-terminal end of the 21K fragment is identical with that of the 34K somatomedin-binding protein, our results suggest that the 21K fragment is the N-terminal part of somatomedin-binding protein, and the somatomedin-binding domain resides in this N-terminal portion.

Amino Acid Sequence↗
PubMed1986

Oligomerization of pregnancy-specific beta 1-glycoprotein (SP1) at physiologic pH and ionic strength.

Highly purified pregnancy-specific beta 1-glycoprotein (SP1) migrated in gel electrophoresis as a homogeneous species and behaved as a single species in 6 mol/l guanidinium chloride (GdmCl), both in the ultracentrifuge and HPLC. At physiologic pH and ionic strength, in the absence of GdmCl, SP1 existed in the form of oligomers of apparent molecular weights of 40 000 to greater than 300 000. The specific activity of these oligomers varied over a 5-fold range. Electrophoretic mobility also varied among SP1 oligomers, with increasing (alpha-like) mobility shown by oligomers of increasing molecular size. Oligomerization may explain some or all of the reports of SP1 heterogeneity.

Chromatography, High Pressure Liquid↗
PubMed1986

Technical notes on chronic fluid-filled catheters and renal artery constrictors for testing hemodynamic drug effects in conscious hypertensive dogs.

Construction and chronic implantation of fluid-filled arterial and ventricular catheters and renal artery constrictors for testing hemodynamic drug effects in conscious dogs are described. The two catheters were made from commercially available silicone rubber and Tygon tubing connected by a molded silicone rubber plate. The blood pressure catheter was inserted via the superficial iliac artery into the abdominal aorta; and the left ventricular catheter, through the apex of the heart. Application of silicone rubber constrictors to both renal arteries resulted in the following hemodynamic values: BPs 180 +/- 4 mm Hg; BPd 111 +/- 2 mm Hg; LVPdp/dt max 3250 +/- 122 mm Hg/sec; and HR 82 +/- 4 beats/sec. Simultaneous recording of LVP and dp/dt signals with Millar Micro-Tip and fluid-filled catheters revealed a difference in signal form and size. Damping the LVP signal of the fluid-filled catheter either with a low-pass filter of 10-30 Hz or using 2-3% dextran solution as catheter fluid abolished this difference. However, a time lag and a difference in dynamic response to positive inotropic agents were still present. Based on our findings, fluid-filled ventricular catheters are recommended for routine work. The effects of antihypertensive, antianginal, and cardiotonic reference compounds could be easily detected with this methodology.

Animals↗
PubMed1986

Human endometrium and menstrual fluid contain placental protein 5 (PP5).

Placental protein 5 (PP5), a serine protease inhibitor, was found in the endometrium and menstrual fluid of non-pregnant women. PP5 was present in all 16 endometrial samples taken at various phases of the menstrual cycle. In the secretory phase, the endometrial PP5 content was higher (median 17.4 micrograms/g protein; n = 8) than in the proliferative phase (median 3.8 micrograms/g protein; n = 8). In gel filtration, endometrial tissue homogenates yielded one immunoreactive peak corresponding to a mol. wt of 28,000 daltons, whereas placental PP5 eluted at 32,000 daltons. In sodium dodecyl sulphate polyacrylamide gel electrophoresis, endometrial PP5 comigrated with purified placental PP5 corresponding to a mol. wt of 30,000 daltons. All menstrual fluid samples (n = 14) contained immunoreactive PP5 at concentrations from 77 to 1150 micrograms/l. The mol. wt of menstrual fluid PP5-immunoreactivity was 13,000 daltons. The dose-response curves of purified PP5 standard and endometrial and menstrual fluid PP5 were parallel in the PP5 radioimmunoassay. The higher concentration of PP5 in secretory endometrium indicates association of PP5 with endocrine events of the menstrual cycle.

Adult↗
PubMed1986

Synthesis of placental protein 12 by human endometrium.

We have previously shown that placental protein 12 (PP12) is synthesized and secreted by human term pregnancy decidua in vitro. In the present study, fragments of proliferative and secretory phase endometrium were cultured in media in the presence and absence of progesterone (P) and 17 beta-estradiol (E2) for 96 h. The PP12 concentrations in the media and tissues were measured by RIA, and de novo synthesis was investigated by measuring the incorporation of [35S]methionine into PP12. Before culture, PP12 could not be detected in any proliferative endometria, whereas all secretory endometria contained PP12. All secretory endometria released PP12 into the medium in the presence and absence of added P and E2. Secretory endometria released significantly more PP12 than proliferative endometria. Three of seven proliferative endometria did not release PP12 in the absence of P, but all did so after P had been added. The addition of P to culture medium caused a 2.4-to over 71-fold increase in PP12 secretion over control values in proliferative endometria and up to a 3.5-fold increase in secretory endometrium. E2 had no significant effect. Cycloheximide totally inhibited the PP12 release induced by P from proliferative endometrium, and in secretory endometrium, it either totally blocked PP12 release or inhibited the stimulation due to P. [35S]Methionine was incorporated into immunoprecipitable PP12 in cultures of secretory and P-treated proliferative phase endometria. These results demonstrate de novo synthesis of PP12 by nonpregnant endometrium in tissue culture and suggest that the biosynthesis and secretion of PP12 by nonpregnant endometrium are regulated by P.

Culture Techniques↗
PubMed1986

Placental protein 12 is a decidual protein that binds somatomedin and has an identical N-terminal amino acid sequence with somatomedin-binding protein from human amniotic fluid.

Placental protein 12 (PP12) was originally isolated from term human placenta and adjacent membranes. Recently we found that the site of PP12 synthesis is decidua but not placenta. In this work, the purity of PP12 was first tested by sodium dodecyl sulfate polyacrylamide slab-gel electrophoresis and by reverse phase HPLC, and the N-terminal amino acid sequence of 15 residues was determined by a liquid-phase sequencer. A single amino acid sequence of Ala-Pro-Trp-Gln-Cys-Ala-Pro-Cys-Ser-Ala-Asp-Glu-Leu-Ala-Leu was obtained showing identity to the known N-terminal amino acid sequence of somatomedin-binding protein from human amniotic fluid. Like the latter, PP12 bound somatomedin (insulin-like growth factor I) as demonstrated in gel chromatography by a shift in the elution pattern of [125I]iodo-insulin-like growth factor I after incubation with PP12. These data show that PP12 is a somatomedin-binding protein and extend through previous literature on PP12 the existing knowledge on the physiology and pathophysiology of somatomedin-binding protein(s) in human reproduction and cancer.

Amino Acid Sequence↗
PubMed1986

Synthesis of placental protein 12 by decidua from early pregnancy.

The synthesis and secretion of placental protein 12 (PP12) by early pregnancy decidua and trophoblast were studied in vitro from tissues obtained by curettage during elective termination of pregnancy (weeks 8-14). The tissue explants were incubated in Ham's F-10 medium for a 27-h period, and the PP12 levels in media and tissue homogenates were measured by RIA. De novo synthesis of PP12 was assessed by measuring the incorporation of radioactivity into PP12 after 20 h of incubation of tissues with 20 microCi/ml [35S]methionine. PP12 from the culture medium was immunoprecipitated with anti-PP12(A) antiserum, and the immunoprecipitate was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The initial tissue content of PP12 was 10- to 72-fold higher in decidua than in trophoblast. The total amount of radioimmunoassayable PP12 released into medium by decidual explants during the 27-h incubation period together with that present in the tissues at the end of incubation exceeded the initial tissue content by 242.7 +/- 63.7% (mean +/- SE). Only small amounts of PP12 were detected in media from trophoblast cultures. During the first 7 h of incubation, inclusion of cycloheximide had no effect on PP12 release by decidual explants in three of four experiments. Between 7 and 27 h, the amount of PP12 released by cycloheximide-treated tissues was 20.0 +/- 7% of that released by control tissues (P less than 0.01). Cycloheximide had no effect on PP12 release by trophoblasts. Decidual explants incorporated [35S]methionine into PP12, but trophoblasts did not. In sodium dodecyl sulfate-gel electrophoresis, the newly synthesized PP12 comigrated with the major band of purified PP12 corresponding to mol wt 29,000. These data clearly confirm that PP12 is a protein of decidual rather than trophoblastic origin, and indicate that decidua from early pregnancy has the ability to synthesize it.

Decidua↗
PubMed1986

Serum levels of placental protein 14 reflect ovulation in nonconceptional menstrual cycles.

Placental protein 14 (PP14), originally isolated from the human placenta and its adjacent membranes, was detected in the serum of nonpregnant women. The levels were measured by radioimmunoassay in 218 serum samples from 19 women throughout the menstrual cycle. In 13 women with a normal ovulatory cycle, the levels showed consistent variation. They were highest (up to 172 ng/ml) in the late secretory phase and remained high for the first days of the next cycle. Low concentrations were found from the midproliferative to the early luteal phase of the cycle. No similar variation was seen in anovulatory cycles of six other women. Compared with ovulatory cycles, anovulatory cycles exhibited lower PP14 levels in the latter part of the cycle (P less than 0.001) and in the beginning of the next cycle (P less than 0.01). In ovulatory cycles, the sustained elevation of serum PP14 concentration over the following period may be explained by the fairly long half-life (42 hours) of PP14 in serum: once the level has increased, it declines slowly. These results suggest that PP14 measurement may become a novel means to distinguish between ovulatory and anovulatory cycles even after the onset of the next period.

Adolescent↗
PubMed1985

Placental protein 5 (PP5) inhibits thrombin-induced coagulation of fibrinogen.

The effect of Placental Protein 5 (PP5) on thrombin-induced coagulation of diluted fibrinogen is described. In contrast to previous reports which failed to demonstrate antithrombin-like activity for PP5 on synthetic substrates, we show in this study that PP5 inhibits thrombin activity in a dose-dependent manner. PP5 acts thus in a very similar way to antithrombin III (ATIII). Although PP5 binds to heparin, it does not show any heparin-cofactor activity. Whereas catalytic amounts of heparin accelerate greatly the inhibitory effect of ATIII, no accelerating effect of heparin on PP5 could be observed under the same conditions. In spite of its anti-thrombin activity, PP5 cannot be considered as a pregnancy-analogue of ATIII, as it lacks the heparin-cofactor activity.

Antithrombin III↗
PubMed1985

Isolation and characterization of two membrane-associated placental tissue proteins.

Two membrane associated placental tissue proteins (PP4 and MP1) have been isolated and characterized. Both proteins are found in the soluble as well as solubilized protein fractions of the human placenta and thus appear to be at least partly associated with placental membranes. PP4 has a molecular weight of 35000 and apparently consists of a single peptide chain. It has an electrophoretic mobility in between the alpha 1- and alpha 2-globulins, an isoelectric point of 4.85 and a sedimentation coefficient of 3.3 S. The carbohydrate content of PP4 amounts to 2.4%. MP1 was isolated from placental protein fractions solubilized with Triton X-100. It has a molecular weight of around 18000 and appears to be composed of two identical subunits which are non-covalently linked. MP1 was found to have an electrophoretic mobility in between the alpha 2- and beta 1-globulins, an isoelectric point of 4.75 and a sedimentation coefficient of 6.65 S. MP1 is a glycoprotein which contains 9.6% carbohydrates. Immunochemical methods were used to detect and quantitate PP4 and MP1 in extracts of placentae and other human tissues. MP1 appears to be specific to the placenta, whereas PP4 was found to occur also in certain other human tissues. The diagnostic significance of detection and measurement of these proteins in tissues and body fluids is presently under investigation.

Chromatography, Gel↗
PubMed1985

Isolation and characterization of four new placental tissue proteins (PP18, PP19, PP20, PP21).

Four new soluble placental tissue proteins (PP18, PP19, PP20, PP21) have been isolated to purity from saline extracts of human term placentas. Two of the new proteins appear to be partly associated with placental membranes; they also could be detected in placental protein fractions obtained by extracting the insoluble part of the placental tissue with solubilizing agents after the soluble material had been removed by washing with saline. The new placental proteins were characterized by their physical properties as well as by their carbohydrate and aminoacid compositions. Specific antisera to the new proteins were obtained by immunizing animals with the corresponding purified proteins. They were used to detect and quantitate the new proteins in extracts of placentas and other human tissues by immunochemical methods. From one human term placenta an average of 2 mg PP18, 90 mg PP19, 0.5 mg PP20, and around 7 mg PP21 could be extracted. None of these new proteins is specific to the placenta; they also were found to occur in extracts of certain other human tissues. The immunohistochemical localization of these proteins as well as measurement of their concentrations in body fluids by sensitive radioimmunoassays are presently under investigation.

Amino Acids↗
PubMed1985

Placental protein 10 (PP10) in normal pregnancy and cholestasis of pregnancy.

The circulating concentrations of placental protein 10 (PP10) were measured by radioimmunoassay in 288 women with normal pregnancy and ten women (55 samples) with cholestasis of pregnancy. Serum PP10 levels were not affected by changes in incubation and storage temperature, and no diurnal variation was observed. The highest PP10 levels (36-85 micrograms/l) in normal pregnancy were found at 34 weeks. The postpartum decline of serum PP10 concentration corresponded to an average half-life of 18 h. In cholestasis of pregnancy at 32-39 weeks, the serum PP10 levels were found to be lower than normal. Negative correlation was observed between aminotransferase and PP10 levels in serum and between the bile acid levels and the PP10 concentration. These results suggest that the severity of maternal liver disorder is reflected in the circulating PP10 concentration.

Bile Acids and Salts↗
PubMed1985

Placental protein 12 (PP12): a new test for the prediction of the small-for-gestational-age infant.

The circulating levels of placental protein 12 (PP12) and placental lactogen (hPL) were measured in 501 women between 36 and 41 weeks gestation. There was a significant positive association between hPL levels and infant birthweight and a significant negative association in the case of PP12 levels. The clinical efficiency of elevated PP12 levels in the prediction of low-birthweight infant at term compared favourably with that of reduced hPL levels.

Birth Weight↗
PubMed1985

Distribution of placental protein 14 in tissues and body fluids during pregnancy.

Placental protein 14 (PP14) levels were measured in serum samples from non-pregnant and pregnant women, amniotic fluid, cord blood, and extracts of placenta, decidua and fetal membranes. The levels were low (15-40 micrograms/l) in serum of non-pregnant women. In four pregnancies following in-vitro fertilization, the serum PP14 levels started to rise 2-12 days after embryo replacement. In normal pregnancy, the highest serum PP14 concentrations (up to 2200 micrograms/l) were detected between 6 and 12 weeks. After 16 weeks the level decreased and plateaued at 24 weeks to around 200 micrograms/l. In amniotic fluid, the highest PP14 levels (232 mg/l) were found between 12 and 20 weeks, being considerably higher than those in maternal serum throughout pregnancy. In cord blood, the levels were low (15-22 micrograms/l) or undetectable. In early pregnancy decidua, the PP14 content was higher (41-160 mg/g total protein) than in late pregnancy decidua (60-2700 micrograms/g total protein). In amnion and chorion laeve, the PP14 concentration varied from 50 to 750 and 50 to 1000 micrograms/g protein, respectively. Early pregnancy placenta contained 0.25-15 mg/g and late pregnancy placenta 3-430 micrograms/g protein of PP14. These results show that the levels of PP14 in pregnancy serum have a similar profile to hCG, but in contrast to other placental proteins, the amniotic fluid PP14 levels are remarkably high. This may be explained by suggesting that decidua is a source of PP14.

Amniotic Fluid↗