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Gross cystic disease of the breast is one of the most common diseases of adult females. Breast cyst fluid contains various steroid hormones. In order to obtain more information about the concentrations of 4- and 5-ene steroids in human breast cyst fluids, levels of pregnenolone sulfate (PREGS), pregnenolone (PREG), dehydroepiandrosterone sulfate (DHEAS) and dehydroepiandrosterone (DHEA) were determined by high-performance liquid chromatography (HPLC). A total of 35 human breast cyst fluid samples, obtained from 35 patients (28-54 years old) were analyzed. Cyst fluid electrolytes were simultaneously determined. Levels of PREGS (mean+/-S.D.) were 26.9+/-20.0 micromol/l (N=35) and of PREG were0.1 micromol/l. Levels of DHEAS and DHEA were 89.1+/-111.7 micromol/l (N=35) and 0.3+/-0.2 micromol/l (N=35), respectively. Cyst fluids were divided into two groups (types I and II) according to their electrolyte ratio (K(+)/Na(+)). The cysts of the type I group (K(+)/Na(+)1.5) contained significantly higher levels of PREGS (39.9+/-21.1 micromol/l) and DHEAS (133.2+/-87.9 micromol/l) than those of the type II group (K(+)/Na(+)1.5), the mean levels of which were 19.8+/-16.2 micromol/dl for PREGS, and 36.3+/-29.0 micromol/dl for DHEAS (P0.05). PREGS and DHEAS levels in the cysts were significantly correlated (r=0.49; P0.01). Human breast cyst fluids contain high concentration of DHEAS and PREGS, especially in the cyst fluids containing high K(+)/Na(+) ratios.

Radioimmunoassay (RIA) is the most prevalent method for measuring small amounts of hormones, peptides, and other compounds in human body fluids. The method, however, has several problems, such as cross reactions or non-specific reactions of the antibody used. In order to establish an improved method for assaying dehydroepiandrosterone sulfate (DHEAS) and cholesterol, which are the largest components of human breast cyst and duct fluids, we describe a simple, accurate, and sensitive method using high-performance liquid chromatography (HPLC). The samples were treated with cholesterol oxidase for quantitation of dehydroepiandrosterone (DHEA) and free cholesterol, and the respective oxidized substances, 4-androstene-3,17-dione and 4-cholesten-3-one, were extracted with n-hexane. The extracts were analyzed by straight phase HPLC. Effluents were monitored by measuring absorption at 240 nm, where a newly introduced chromophoric group, an alpha,beta-unsaturated ketone, showed intense absorption (epsilon = 16,000). When the total amount of DHEA (DHEAS plus DHEA) was measured, the sample had been solvolyzed by sulfatase beforehand. The amounts of DHEAS were quantified by comparing the amounts of DHEA before and after solvolysis. Levels of free cholesterol, DHEAS, and DHEA in human breast cyst fluids (n = 30) were 1.77 +/- 1.12 mmol/dl, 8.27 +/- 10.24 micromol/dl, and 0.02 +/- 0.02 micromol/dl (means +/- SD), respectively. The levels of sterol and steroid measured in breast duct fluids that were turbid, brown, dark green, or milky in color (n = 9) (mean levels, 3.20 +/- 2.97 mmol/dl for free cholesterol and 14.77 +/- 13.75 micromol/dl for DHEAS) were significantly (P0.01) higher than the levels in clear or serous breast fluids (n = 21) (mean levels, 0.14 +/- 0.13 mmol/dl for free cholesterol and 0.04 +/- 0.07 micromol/dl for DHEAS).

Cross-linked modifications of Taka-amylase A (TAA) with various dialdehyde derivatives including starch- and dextran-dialdehyde were examined. A rapid and significant decrease in the amount of free amino groups and enzyme activity of TAA was attained by starch-dialdehyde, whereas dextran dialdehyde caused much lower loss in activity of TAA in spite of a similar extent of amino group modification. The molecular weight of the dextran-modified TAA increased by about 10, 000-20, 000 Da, which was measured by SDS-gel electrophoresis. A comparison of the activity of modified TAA on various substrates indicated a slight but definite increase in susceptibility to maltose and phenyl α-glucoside according to the increase in the extent of modification of TAA. In contrast, the activity of the modified TAA on maltotriose, maltotetraose, and γ-cyclodextrin decreased upon modification. Here, again, TAA modified with dextran-dialdehyde retained higher activity to those oligosaccharides than that modified with starch-dialdehyde. Moreover, inactivation caused by the fluorescent reagent, o-phthalaldehyde, was retarded by previous modification with dextran-dialdehyde, indicating that reaction between TAAand dialdehyde derivatives occurred through non-critical amino groups for enzyme activity.

Tumor necrosis factor-alpha (TNF) markedly stimulates the synthesis and secretion of immunoreactive nerve growth factor (NGF) in quiescent mouse fibroblasts, which is a result of increase in the NGF mRNA level. NGF produced by TNF-treated fibroblasts has a molecular mass of 13 kDa on SDS-polyacrylamide gel electrophoresis, which is consistent in size with the subunit of mouse beta-NGF, and induces neurite outgrowth in paravertebral sympathetic neurons. Several peptide growth factors such as basic fibroblast growth factor (bFGF) and epidermal growth factor also stimulate NGF production in the cells, but not platelet-derived growth factor. The dose responses of TNF and bFGF to stimulate NGF production in the cells are, respectively, similar to those to induce cell proliferation. However, no correlation is observed between the ability of these growth factors to stimulate NGF production and that to induce cell proliferation. Thus, the stimulation of NGF production in the cells seems to be a specific activity of TNF and some other growth factors. TNF stimulates the synthesis and secretion of NGF also in other cells such as human glioblastoma cells. These findings suggest that TNF plays a role in regulating neuronal cell function through an indirect mechanism by which it stimulates NGF production in glial cells and fibroblasts.

The train millipede (Parafontaria laminata armigera) emits a blue fluorescence (λ(max)=455 nm) under black light (350 nm). The isolated fluorescent compound from the cuticle of P. laminata armigera was identified as pterin-6-carboxylic acid. The structure of this compound was identified by fluorescent, HPLC, and mass spectrometric (ESI-ion trap MS) analyses, and then compared with an authentic sample.

Pholasin is a bioluminescent photoprotein of Pholas dactylus. Pholasin is a commercially available photoprotein used to measure intracellular reactive oxygen species. Although extensive efforts have been carried out to determine the chemical structure of the prosthetic (chromophore) group, it still remains unclear to date. Herein, we report the enhancement of pholasin luminescence by the addition of dehydrocoelenterazine, which is organic substance of luminous squids' photoprotein.

We have examined the possible involvement of pertussis toxin (PT)-sensitive GTP-binding protein and protein kinase C (PKC) in mitogen-induced tyrosine phosphorylation of the 41 kDa and 43 kDa cytosol proteins using PT-pretreated (inactivation of PT-sensitive GTP-binding protein) or phorbol 12-myristate 13-acetate (PMA)-pretreated (depletion of PKC) mouse fibroblasts. The effects of the inactivation of PT-sensitive GTP-binding protein and the depletion of PKC on mitogen-stimulated tyrosine phosphorylation of the proteins were similar and varied significantly and systematically in response to growth factors. The important finding was that such inhibitory effects of PT-sensitive GTP-binding protein inactivation and PKC depletion on protein tyrosine phosphorylation induced by each mitogen always correlated well with their inhibitory effects on each mitogen-stimulated DNA synthesis. Although the extent of platelet-derived-growth-factor-induced phosphorylation of the proteins was decreased to approx. 50% in PT- and PMA-pretreated cells compared with native cells, protein phosphorylation itself was not affected and occurred at identical sites on each protein in native, PT- and PMA-pretreated cells. These results suggest that: (1) 41 kDa and 43 kDa proteins are located downstream of PT-sensitive GTP-binding protein and PKC in the mitogenic signalling pathways of growth factors, (2) protein phosphorylation occurs via a cascade of events which includes the activation of the receptor tyrosine kinases, PKC and other unidentified kinase(s) which directly participate(s) in the phosphorylation of the 41 kDa and 43 kDa proteins, and (3) their phosphorylation may play an important role in integrating multiple mitogenic signalling pathways.

We have examined the hepatocyte growth factor (HGF)-mediated changes in protein-tyrosine phosphorylation in mouse keratinocytes (PAM-212) and canine kidney epithelial cells (MDCK). In PAM-212 cells HGF and epidermal growth factor, both of which stimulated the DNA synthesis, rapidly induced the tyrosine phosphorylation of two 41-kDa and two 43-kDa proteins: increased tyrosine phosphorylation of those proteins has been commonly observed when quiescent fibroblasts are stimulated with a variety of mitogenic agents. In contrast, HGF did not stimulate the DNA synthesis but induced cell dissociation in MDCK cells; under this condition, increased tyrosine phosphorylation of the 41-kDa and 43-kDa protein was not observed. A possible role of the increased tyrosine phosphorylation of 41-kDa and 43-kDa protein in the signaling pathway of HGF is discussed.

Two antipeptide antibodies, one against the peptide corresponding to residues 307-327 (alpha Y91) and one against the peptide corresponding to the C-terminal portion (alpha C92) of the deduced amino acid sequence of the extracellular signal-regulated kinase 1 (ERK1), precipitated two 41-kDa and/or two 43-kDa phospho-proteins from mitogen-stimulated Swiss 3T3 cells. Electrophoretic mobilities on two-dimensional gels of the immunoprecipitated 41- and 43-kDa phosphoproteins were similar to those of the 41- and 43-kDa cytosol proteins, whose increased tyrosine phosphorylation we and others had originally identified in various mitogen-stimulated cells (Cooper, J. A., Sefton, B. M., and Hunter, T. (1984) Mol. Cell. Biol. 4, 30-37; Kohno, M. (1985) J. Biol. Chem. 260, 1771-1779); phosphopeptide map analysis revealed that they were respectively identical molecules. All those phosphoproteins contained phosphotyrosine, and the more acidic forms contained additional phosphothreonine. Immunoprecipitated 41- and 43-kDa phosphoproteins had serine/threonine kinase activity toward myelin basic protein (MBP) and microtuble-associated protein 2 (MAP2). With the combination of two-dimensional gel electrophoresis and the kinase assay in MBP-containing polyacrylamide gels of the alpha Y91 immunoprecipitates, with or without phosphatase 2A treatment, we showed that only their acidic forms were active. These results clearly indicate that 41- and 43-kDa proteins, the increased tyrosine phosphorylation of which is rapidly and commonly induced by mitogen stimulation of fibroblasts, are family members of ERKs/MAP2 kinases and that phosphorylation both on tyrosine and threonine residues is necessary for their activation.