Effect of glucose and an aldose reductase inhibitor on myo-inositol uptake by cultured human endothelial cells.

The effects of an aldose reductase (AR) inhibitor, elevated glucose and other compounds were evaluated on in vitro 2-[3H] myo-inositol (MI) uptake in cultured human endothelial cells (ECs). Significant AR activity was present in ECs (1,373 +/- 170 mumol/mg.min: incubated with 28 mM glucose for 48 hr).

Viral DNA detected by in situ hybridization in the developing mouse brain infected with murine cytomegalovirus.

To investigate the pathogenesis of brain abnormalities caused by congenital cytomegalovirus (CMV) infection, we previously reported experimental murine models of brain damage induced by intraventricular injection of murine CMV (MCMV) at the late stage of gestation. In the present study, viral DNA-positive cells in the damaged brain at different postnatal stages detected by in situ hybridization were compared with viral antigen-positive cells detected by an immunoperoxidase method using a monoclonal antibody against the immediate early antigen. At birth, the number of viral DNA-positive cells almost equalled that of viral antigen-positive cells.

Arg-X-Lys/Arg-Arg motif as a signal for precursor cleavage catalyzed by furin within the constitutive secretory pathway.

Many peptide hormones are produced from larger precursors by endoproteolysis at pairs of basic amino acids (e.g. Lys-Arg and Arg-Arg) within the regulated secretory pathway in endocrine cells.

Sequence requirements for prohormone processing in mouse pituitary AtT-20 cells. Analysis using prorenins as model substrates.

Although cleavage of peptides at sites marked by paired basic amino acids is a common feature of prohormone processing, little is known about the properties of endoprotease(s) responsible for cleavage of the precursor. To examine the cleavage specificity of a processing endoprotease, we have altered the Lys-Arg cleavage site of human prorenin to Arg-Arg, Lys-Lys and Arg-Lys by site-directed mutagenesis, and expressed the native and mutated precursors in mouse pituitary AtT-20 cells which are known to process foreign prohormones, including prorenin, at paired basic sites during the regulated secretory process. All native and mutated human prorenins were sorted into the regulated secretory pathway.

Distribution of labeled Clostridium perfringens epsilon toxin in mice.

The in vivo distribution of labeled Clostridium perfringens epsilon toxin after i.v. administration to mice was investigated.

Postnatal porencephaly induced in mouse by murine cytomegalovirus.

Mouse embryos were infected with murine cytomegalovirus (MCMV) by injecting the virus into the cerebral ventricles at the late gestation. After deliveries, offspring were fed by the mothers until 4 weeks. Cystic brain lesions, regarded as porencephaly or paraventricular cysts, were observed in about 20% of the MCMV-injected offspring 3 to 4 weeks after birth.

Substrate specificity of prorenin converting enzyme of mouse submandibular gland. Analysis using site-directed mutagenesis.

Renin is produced from a larger, inactive precursor, prorenin, through endoproteolytic cleavage at paired basic amino acids. Recently, we have purified and characterized an enzyme, which catalyzes the endoproteolytic process, from mouse submandibular gland. The enzyme, named prorenin converting enzyme, specifically cleaves the peptide bond on the COOH-side of the Arg residue at the Lys-Arg pair of mouse Ren 2 prorenin, but does not cleave mouse Ren 1 and human prorenins.

Effect of prior treatment with Clostridium perfringens epsilon toxin inactivated by various agents on lethal, pressor and contractile activities of the toxin.

Lethal and pressor activities, and the contractile responses of rat isolated ileum to Clostridium perfringens epsilon toxin, were significantly prevented by the prior administration of epsilon toxin inactivated by 1-ethyl-3-(3-diethyl-aminopropyl) carbodiimide in the presence of glycine methyl ester (EDC), 2,4,6-trinitrobenzene sulfonic acid (TNBS), succinic anhydride (SA) and ethoxyformic anhydride (EFA). However, the prior administration of the toxin inactivated by N-acetylimidazole (NAI), tetranitromethane (TNM) and N-bromosuccinimide (NBS) resulted in no inhibition of these biological activities. These data suggest that the toxin interacts with specific site(s) on target organs or tissues.

Effects of propeptide deletion on human renin secretion from mouse pituitary AtT-20 cells.

To study the role of the N-terminal propeptide in the secretory process of renin, mouse pituitary AtT-20 cells were transfected with expression plasmids of human preprorenin and a mutant deleted of its propeptide. The transfectant of the native construct secreted inactive prorenin and active renin, and renin secretion was stimulated by a secretagogue, 8-Br-cAMP. On the contrary, the transfectant of the deleted construct secreted only active renin, whose release was also stimulated by the secretagogue.

Subcellular distribution of GTP-binding proteins, Go and Gi2, in rat cerebral cortex.

The localization of GTP-binding protein (G-protein) subunits, Go alpha, Gi2 alpha and beta, in subcellular fractions of rat cerebral cortex was determined by means of immunoassays specific for the respective subunits. High concentrations of all three subunits were observed in both crude mitochondrial and microsomal fractions. Muscarinic cholinergic receptors were also densely localized in these fractions.

[Distribution of preganglionic cells of superior cervical ganglion in the spinal cord in the cat].

It is generally accepted that preganglionic neurons of the cervical sympathetic nerve arise from the ciliospinal center, which exists in the spinal cord over C8-T3. However, its distribution within the spinal cord has not been exactly demonstrated. Therefore, horseradish peroxidase (HRP) was injected into the cervical sympathetic trunk in order to demonstrate the distribution of preganglionic neurons in the spinal cord in the cat.

Site-directed mutagenesis of human prorenin. Substitution of three arginine residues in the propeptide with glutamine residues yields active prorenin.

Human prorenin is an inactive zymogen comprising 43 amino acid residues at the amino terminus of human renin. The aim of this work was to determine why prorenin is inactive at neutral pH. Eighteen different mutant prorenins, in which positively charged residues in the propeptide were substituted with either glutamine (Gln) or lysine (Lys) residues by site-directed mutagenesis, were expressed in COS-7 cells and characterized.

Expression of a deletion mutant of the prosegment of human prorenin in Chinese hamster ovary cells.

Expression plasmids encoding native human preporenin and a mutant deleted in its entire prosegment were transfected into Chinese hamster ovary cells. The cells transfected with the expression plasmid of native preporenin secreted exclusively inactive prorenin, while the cells transfected with the mutant secreted the active enzyme. The secreted amount of renin from the latter cells was much lower than that of prorenin from the former ones, although these two enzymes had little difference in specific activity after trypsin activation.

Prorenin is sorted into the regulated secretory pathway independent of its processing to renin in mouse pituitary AtT-20 cells.

A native human prorenin and a mutant of its processing site (Arg-43 to Gln) were expressed in mouse pituitary AtT-20 cells which process prorenin to renin and have both regulated and constitutive secretory pathways. The native prorenin was processed to renin and secreted in a regulated manner. Although the mutant precursor was not processed, it was also secreted in a regulated manner.

[Chondrosarcoma of the ribs: report of two cases].

Chondrosarcoma of rib origin is relatively rare in Japan. Two patients with chondrosarcoma of rib origin were treated surgically. Case 1: A 79-year-old male, 4 years ago, he noticed a tumor in the left anteroinferior part of the chest.

Contraction induced by Clostridium perfringens epsilon toxin in the isolated rat ileum.

Clostridium perfringens epsilon toxin caused contraction of the isolated ileum of the rat in a dose-dependent manner. The contraction caused by the toxin was inhibited by a low Na medium, tetrodotoxin (TTX), atropine, mecamylamine or tetraethylammonium (TEA). Furthermore, the contractile response induced by the toxin was abolished by incubation in Ca-free medium, and completely restored by and addition of Ca2+.

Susceptibility of brain cells to murine cytomegalovirus infection in the developing mouse brain.

Mouse embryos were infected with murine cytomegalovirus (MCMV) by injecting the virus into the cerebral ventricles in the late stage of gestation; the brains of the offspring were than analyzed using the histological and immunohistochemical methods. Brains of the offspring, which were injected with relatively high titers of MCMV [1 X 10(4) plaque-forming units (pfu)] on day 13 of gestation exo utero or on day 15 of gestation in utero, showed massiv necrosis of the cerebral cortex with gliomesodermal proliferation around 9 to 10 days after birth. In these brains, viral antigen-positive cells were observed in zonal arrangement in the lesion-free cortex and in the hippocampus.

A case of ovarian granulosa cell tumor with invasive adenocarcinoma of the endometrium. A case report and review of the Japanese literature.

A 47-year-old woman was admitted complaining of irregular uterine bleeding. On surgery, an ovarian tumor was found together with a broad-based polypoid endometrial mass. These lesions were histologically diagnosed as granulosa cell tumor with invasive adenocarcinoma of the endometrium.

Functional characterization of Asp-317 mutant of human renin expressed in COS cells.

Renin is an unique aspartyl (acid) protease with optimal activity at neutral pH. It has been suggested that Ala-317 of human renin contributes to neutral optimum pH of the enzyme [(1984) FEBS Lett. 174, 102-111].

Interdigitating cell sarcoma. A morphologic, immunohistologic, and enzyme-histochemical study.

A 58-year-old man presented with an unusual sarcoma of the cervical lymph node. The tumor also involved the mesenteric lymph node and jejunum. Tumor cells possessed intracytoplasmic S100 protein, Leu-3a (T4), and HLA-DR antigens.

Peptide-containing nerves around blood vessels of stroke-prone spontaneously hypertensive rats.

The distribution and density of nerves containing vasoactive intestinal polypeptide, substance P, and neuropeptide Y around the cerebral and peripheral blood vessels of stroke-prone spontaneously hypertensive rats (SHRSP) and normotensive Wistar-Kyoto rats (WKY) were studied using an indirect immunofluorescence technique. Neonatal sympathectomy of SHRSP with anti-nerve growth factor and guanethidine was also carried out to study the effect of sympathectomy on the distribution of these nerves. Vasoactive intestinal polypeptide nerve density was higher in the veins and superior mesenteric artery of SHRSP than of WKY and lower in the cerebral arteries of SHRSP than of WKY, but no difference was found in the muscular mesenteric arteries.

[A case of ovarian granulosa cell tumor with invasive adenocarcinoma of the endometrium].

A case of an ovarian granulosa cell tumor with an invasive adenocarcinoma of the endometrium, and a review of the relevant Japanese literature is reported. A 47-year-old woman was admitted to Ichinomiya Citizens' Hospital complaining of irregular uterine bleeding. On operating, an ovarian tumor was found with a broad-based polypoid mass extending into the endometrium.