Origin of bombesin-like peptides in human fetal lung

Four different forms of bombesin-like immunoreactive peaks were detected in extracts of human fetal lung by the use of reversed-phase high performance liquid chromatography (HPLC). Peaks I, II, III and IV, (increasing retention time), were eluted using a 14-38% of acetonitrile gradient containing 0.1% trifluoroacetic acid (TFA). Peak II was the major material found in the extract of human fetal lung obtained at 16-20 weeks gestation. None of the four compounds contained in the eluted peaks had the same retention time as amphibian bombesin or porcine gastrin releasing peptide (GRP). On reversed-phase HPLC using two different solvent systems TFA or heptafluorobutyric acid (HFBA) as a hydrophobic counter ion, and in gel filtration chromatography, the chromatographic behavior of the main peak (peak II) was the same as that of the carboxyl terminal fragments of GRP, GRP18-27 or GRP19-27. This suggested that the peptide(s) in peak II resembled in composition the carboxy terminal 9 or 10 amino acids of porcine GRP. Following tryptic digestion the material in peak IV was converted to the more polar compound present in peak II. Two other peptide peaks were eluted close to peak II and these were presumed to be a modification of this main peak. One of the possible biosynthetic steps in the formation of bombesin-like peptides in human fetal lung could be a tryptic conversion of a less polar peptide to a more polar form (peak IV to II).     

Structure and expression of cDNA for an inhibitor of blood coagulation isolated from human placenta: a new lipocortin-like protein

An inhibitor of blood coagulation, a new protein with an apparent molecular weight of 34,000 and an isoelectric point of 4.9, was purified from human placental tissue by EDTA extraction. Five cDNA clones were isolated from the human placental lambda gt11 cDNA library using the mouse monoclonal antibody raised against the coagulation inhibitor as the probe. The longest insert consists of 1,566 nucleotides, and contains 960 nucleotides entirely encoding the 320 amino acids of the inhibitor, and a poly A tail. The deduced amino acid sequence was corroborated by chemical analyses of the protein. The entire amino acid sequence shows homology to those of lipocortin I, lipocortin II, and endonexin-related proteins. The cDNA for the inhibitor was expressed in Escherichia coli under the regulation of the trc promotor of the plasmid pKK233-2. The resulting recombinant protein manifested inhibitory activities against both blood coagulation and phospholipase A2 activity, as did the coagulation inhibitor isolated from human placenta.     

Cytokinetic effects of carboplatin and cisplatin on a human ovarian cancer cell line

The cytokinetic effects of carboplatin(CBDCA) on a human ovarian cancer cell line(KF-1) were examined by means of cell survival rate and flow cytometry in comparison with cisplatin(CDDP). CBDCA and CDDP exhibited dose dependent cytotoxicity on KF-1, and CBDCA showed compatible cell growth inhibition to that of 15 times concentration of CDDP in comparison with IC50 of 72 hrs after drug addition. From the analysis of cell cycle, CBDCA and CDDP inhibited cell cycle progression at G2 + M phase. CBDCA exhibited G2 + M phase block to that of 15 to 20 times the concentration of CDDP. We suggested that CBDCA had potential therapeutic activity against ovarian cancer, but should be evaluated carefully in the clinical use.     

Serotonin content of rabbit lung and small intestine during perinatal development

Serotonin (5-hydroxytryptamine, or 5HT) was measured in extracts of rabbit lung and intestine during perinatal development using high pressure liquid chromatography (HPLC) with electrochemical detection. Lung and intestine were extracted with HClo4 and the extract was loaded onto a Bio-Rex 70 resin column. After elution with acetic acid the samples were injected onto the HPLC column. Serotonin was detected in lung and intestine at 18 days of gestation (80 and 90 ng/mg protein). In lung serotonin content increased at day 28 (290 ng/mg protein) till day 30 (680 ng/mg protein) decreased at day 1 after birth (480 ng/mg protein) and then rose at day 10 of the newborn period (650 ng/mg protein). In intestine the serotonin content was always higher than in the lung. At the end of gestation the serotonin in the intestine remained constant (2410 ng/mg protein at day 28 and 2430 ng/mg protein at day 30), decreased slightly one day after birth (2150 ng/mg protein) and rose at day 10 (3300 ng/mg protein).     

Preliminary crystallographic data for plastocyanins from an alga (Enteromorpha prolifera) and from cucumber (Cucumis sativus)

The plastocyanins from a green alga (Enteromorpha prolifera) and cucumber (Cucumis sativus) have been crystallized. Crystal data are as follows: E. prolifera plastocyanin, space group I4, a = b = 53.9 A, c = 59.4 A, Z = 8; C. sativus plastocyanin, space group P4(1) (or P4(3) ), a = b = 66.7 A, c = 46.0 A, Z = 8. Accordingly, the asymmetric units of the crystals contain one and two molecules, respectively.     

Isolation and characterization of an anticoagulant protein from human placenta

An anticoagulant protein was purified from the EDTA extract of human placental tissue. The purified protein had a molecular weight of 73,000 on sodium dodecyl sulfate polyacrylamide gel electrophoresis under both reducing and non-reducing conditions. Because this protein had the ability to bind phospholipids such as phosphatidylserine, phosphatidylinositol, and cardiolipin in the presence of Ca2+, this protein was designated as calphobindin II (CPB-II). CPB-II prolonged the clotting time of normal plasma when coagulation was induced by tissue factor, cephalin and ellagic acid or recalcification, but did not affect thrombin-initiated fibrin formation. CPB-II also inhibited the activation of prothrombin by the complete prothrombinase complex or factor Xa-phospholipid-Ca2+ but not that by phospholipid-free factor Xa. In addition, CPB-II had an inhibitory activity against phospholipase A2.     

Induction of proliferation and Ig production in human B leukemic cells by anti-immunoglobulins and T cell factors

The proliferation and differentiation of human leukemic B cells (B-CLL cells) with anti-Ig and T cell-derived helper factors are described. Stimulation of B-CLL cells with anti-Ig and T helper factors could induce proliferation as well as differentiation into IgM- and IgG-producing cells. Neither anti-Ig nor T helper factors alone could induce any proliferation and/or differentiation of B-CLL cells. Not only whole molecules of anti-Ig but also F(ab')2 fragments could induce proliferation and differentiation of B-CLL cells in the presence of T helper factors, but monovalent Fab' fragments were not effective. Induction of both IgM and IgG with the same idiotype was confirmed by immunofluorescent and SDS-PAGE analysis. By employing an IL 2-dependent cytotoxic T cell line and a TRF-responsive B cell line, T cell factors were separated into a fraction with IL2 activity but no TRF activity and a fraction with TRF activity but no IL 2 activity by chromatofocusing. Anti-Ig and IL 2 fraction could induce proliferation of B-CLL cells, but TRF fraction was not effective for the induction of proliferation in anti-IG-stimulated cells. For IgM and IgG production, anti-Ig and both IL 2 and TRF fractions were required. Depletion of IL 2 fraction in the first 2 days' culture inhibited Ig production, whereas the absence of TRF fraction in the first 2 days did not show any inhibitory effect on Ig production.     

Absence of bicarbonate abolishes the glycogenic effect of cortisol in cultured fetal rat hepatocytes

The glycogenic action of cortisol in cultured fetal rat hepatocytes was completely abolished by the absence of NaHCO3 from the medium, while its presence stimulated the action in relation to its concentration. The absence of NaHCO3 slightly reduced glycogen storage by insulin but did not affect glucose-dependent glycogen deposition in the basal state. Also, the cortisol-induced increase in glycogen synthase a activity was reduced but that in total synthase activity was not affected. The absence of NaHCO3 did not reduce the cortisol-induced increase in tyrosine aminotransferase activity and the incorporation of [3H]dexamethasone into the nuclei. These results show that the absence of NaHCO3 specifically inhibits the glycogenic action of glucocorticoids in cultured fetal rat hepatocytes and indicate the need for further investigation into the role of HCO3- in universally used bicarbonate-buffered media.