Identification and change in the receptor for hepatocyte growth factor in rat liver after partial hepatectomy or induced hepatitis

Specific binding of 125I-labeled human recombinant HGF to the primary cultured rat hepatocytes or liver plasma membranes was observed to be temperature- and time-dependent. Scatchard analysis indicated the presence of a single class of high affinity receptors with a dissociation constant (Kd) of 24-32 pM, a value in good accord with half maximum dose for HGF activity and a receptor density of about 500-600 sites/cell. Affinity cross-linking of the receptor with 125I-HGF revealed the HGF receptor in rat liver membranes to be a polypeptide of Mr approximately 220,000. After partial hepatectomy, specific binding of 125I-HGF to the membranes of residual livers decreased by 60-70% between 3 and 6 h, and was scanty at 12 h after hepatectomy. After one week, the binding was recovered to the 1.7 fold level in the untreated rat liver. This rapid down-regulation of HGF receptors was also observed in plasma membranes of rat livers in the presence of hepatitis induced by CCl4. We propose that HGF which can be immediately supplied to the liver after hepatic injury will function as a trigger for regeneration of this organ.     

1H NMR studies on ferricytochromec 3 fromDesulfovibrio vulgaris Miyazaki F and its interaction with ferredoxin I

Summary The¹H NMR signals of the heme methyl, propionate and related chemical groups of cytochromec ₃ fromDesulfovibrio vulgaris Miyazaki F (D.v. MF) were site-specifically assigned by means of ID NOE, 2D DQFCOSY and 2D TOCSY spectra. They were consistent with the site-specific assignments of the hemes with the highest and second-lowest redox potentials reported by Fan et al. (Biochemistry,29 (1990) 2257–2263). The site-specific heme assignments were also supported by NOE between the methyl groups of these hemes and the side chain of Val¹⁸. All the results contradicted the heme assignments forD.v. MF cytochromec ₃ made on the basis of electron spin resonance (Gayda et al. (1987)FEBS Lett.,217 57–61). Based on these assignments, the interaction of cytochromec ₃ withD.v. MF ferredoxin I was investigated by NMR. The major interaction site of cytochromec ₃ was identified as the heme with the highest redox potential, which is surrounded by the highest density of positive charges. The stoichiometry and association constant were two cytochromec ₃ molecules per monomer of ferredoxin I and 10⁸ M^–2 (at 53 mM ionic strength and 25°C), respectively.     

Goblet-like cells in atrophic vaginal smears and their histologic correlation. Possible confusion with endocervical cells.

The occurrence and origin of goblet-like cells seen between clusters of parabasal cells in atrophic vaginal smears were investigated. The goblet-like cells were cytologically identified in the vaginal smears from 23 (19.2%) of 120 patients whose smears showed an atrophic pattern, but without any inflammatory, dysplastic or malignant changes. Histologically, these cells were found in sections from 6 (18.8%) of 32 elderly women with atrophic vaginal epithelium. The goblet-like cells were situated among the squamous cells of the upper layer of the atrophic squamous epithelium from the vagina to the portio. These goblet-like cells in atrophic smears were initially misinterpreted as endocervical cells, which are regarded as a marker of smear adequacy in the cytologic screening for cancer of the uterine cervix. The correct interpretation of these goblet-like cells in smears from postmenopausal and elderly women is thus obviously important in assessing the adequacy of the sample for the detection of abnormal cells.     

Formation of catharanthine,akuammicine and vindoline in Catharanthus roseus suspension cells

Catharanthine and akuammicine, together with ajmalicine and strictosidine, were isolated from a culture strain of Catharanthus roseus suspension cells. The biosynthetic capability of the cultured cells to produce akuammicine, catharanthine and vindoline was confirmed by feeding experiments with dl-tryptophan-[3-¹⁴C] to yield the radioactive alkaloids.     

Biosynthesis of triterpenoids from amino acids in Pisum sativum. The distribution of the radioactivity in squalene biosynthesized from radioisotopically labelled l-leucine and l-valine

Radioisotopically labelled l-leucine and l-valine were fed to Pisum sativum and incorporated into squalene and β-amyrin. Chemical degradation of the radioactive squalene revealed an equal distribution of the radioactivity in the isopentenyl pyrophosphate(IPP)-derived and the 3,3-dimethylallyl pyrophosphate(DMAPP)-derived moieties of the squalene molecule, unlike the unbalanced distribution in favour of the DMAPP-derived moiety of a monoterpenoid molecule biosynthesized from these amino acids by higher plants.     

Initial reactions in the fungal degradation of guaiacylglycerol-β-coniferyl ether,a lignin substructure model

Fusarium solani M-13-1 was shake-cultured in a medium containing guaiacylglycerol-β-coniferyl ether (I), a model compound representing the arylglycerol-β-aryl ether linkage in lignin, as sole carbon source. From the culture filtrate guaiacylglycerol-β-coniferyl aldehyde ether (II) and guaiacylglycerol-β-ferulic acid ether (III) were isolated as metabolic products. Incubation with (III) resulted in formation of guaiacylglycerol-β-vanillin ether (IV), which was further metabolized to guaiacyglycerol-β-vanillic acid ether (V). The results indicate that the cinnamyl alcohol group of (I) is initially oxidized to an aldehyde group, which is further oxidized to a carboxyl group, yielding (II) and (III). Compound (III) is converted to (IV) by the release of a C₂ fragment, and the aldehyde group of (IV) is further oxidized to a carboxyl group, giving (V). In the pathway from (I) to (V), neither oxidation of the benzylic secondary alcohol to ketone nor cleavage of the arylglycerol-β-aryl ether linkage was observed. The fungus was found to attack both erythro and threo form without distinction.     

Immunochemical reactivity of simian sarcoma virus polypeptides isolated by preparative sodium dodecyl sulfate polyacrylamide gel electrophoresis

The polypeptides associated with a zonal centrifugation purified simian sarcoma virus propagated in lymphoblastoid NC-37 cells were isolated by preparative polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS) using a procedure designed to minimize the loss of immunochemical reactivity. The proteins p10, p15, p28, p36, p44, p75, and p86 were obtained in large yield and high degree of homogeneity. The electrophoretically purified p28 was analyzed by competition radioimmunoassay using antiserum to a pore exclusion and ion exchange purified simian sarcoma virus p28. Complete competition was observed with extracts of simian sarcoma virus infected cells. No competition was observed with uninfected or unrelated, infected cell extracts. The antigen-antibody affinity as measured by the slope of the competition curve using antiserum to p28 and 125I-labeled and electrophoretically purified p28 was the same as that for the p28 released from sonication-disrupted simian sarcoma virus. The data indicates that preparative purifications by polyacrylamide gel electrophoresis in the presence of SDS may be generally applicable for the isolation of proteins with essentially the same immunospecificities and affinity for a specific antiserum as proteins isolated by procedures that avoid the use of SDS and electrophoresis.     

A lymphocyte chemotactic peptide released from immunoglobulin G by neutrophil neutral thiol protease.

A thermostable and dialyzable peptide, released from rabbit IgG by rabbit neutrophil neutral thiol protease, exhibited a distinct chemotactic activity for rat lymphocytes; it was assumed to be derived from the Fc fragment (but not from the Fab fragment) by the enzyme. This substance seemed to be effective for adherent cells (B cells) from rat spleen, but not for nonadherent cells (T cells). The chemotactic peptide was purified by gel filtration on Sephadex G-50 and G-15 and then by high-voltage paper electrophoresis. As previously described, the IgG residue after release of dialyzable peptide(s) exhibited chemotactic activity for neutrophils but not for macrophages.     

Histochemical Demonstration of Enzyme Activities in Plastic and Paraffin Embedded Tissue Sections

Histochemical staining for enzymes is usually performed on frozen sections. This report lists the longer incubation times required to demonstrate esterase, acid phosphatase, β-galactosidase, and cytochrome oxidase in plastic embedded and routine paraffin embedded tissues. The sections embedded in plastic, i.e. water soluble methacrylate (Polyscience's JB-4) and cut at 2 μm, were far superior to frozen Sections and paraffin embedded sections both in tissue detail and in the localization of the histochemical reaction product.     

Simplified determination of lorazepam and oxazepam in biological fluids by gas chromatography—mass spectrometry

Lorazepam and oxazepam in plasma and urine were measued by gas chromatography—mass spectrometry. Oxazepam was used as an internal standard in the assay of lorazepam and vice versa. After removal of interfering substances with n-hexane, the drugs were extracted with benzene and converted to N₁,O₃-bistrimethylsilyl derivatives. Glucuronide forms of the drugs were extracted after hydrolysis with β-glucuronidase. A common fragment ion at m/e 429 was used to monitor the two drugs. The sensitivity was 2 ng/ml for both drugs, which was sufficient to determine plasma and urine concentrations after therapeutic doses to humans.