Cloning, sequencing and expression in Escherichia coli of cDNA for a non-A, non-B hepatitis-associated microtubular aggregates protein

A 1.7 kb cDNA encoding a novel antigen (p44; apparent Mr 44K) associated with non-A, non-B (NANB) hepatitis, was isolated from the hepatic cDNA library of a chimpanzee infected with NANB hepatitis. The library was screened with a monoclonal antibody against this antigen. The cDNA cloned contained an open reading frame encoding a 444 amino acid protein with an Mr calculated to be 50,468. The cDNA hybridized to a 1.9 kb mRNA obtained from chimpanzee hepatocytes infected with either the NANB or hepatitis delta viruses. It hybridized weakly to mRNA from hepatitis B virus-infected hepatocytes, and not at all to mRNA from normal chimpanzee hepatocytes. Southern blot analysis revealed that p44 is a host protein in chimpanzees, and that an identical gene exists in the human genome.

Myelinated perikarya of the ganglion cells in the avian retina

The myelinated perikaryon was found in some of the retinal ganglion cells of parrakeet. The cells were covered with a compact myelin composed of 1-10 lamellae. The myelin of the ganglion cells seems to be formed by Müller cell.

Production of antibodies directed against microtubular aggregates in hepatocytes of chimpanzees with non-A, non-B hepatitis

We have previously used Epstein-Barr virus transformation to established two clonal lymphoblastoid cell lines (48-1 and S-1) producing monoclonal antibodies against microtubular aggregates that appear in the hepatocytes of chimpanzees with non-A, non-B hepatitis (NANBH). To obtain additional antibodies directed against the same structure, the mouse hybridoma method was employed. Partially purified microtubular aggregates were prepared from liver homogenates of a chimpanzee with NANBH and used as the immunogen. Hybridoma cultures were first screened by radioimmunoassay against the partially purified antigen and secondly by immunofluorescence (IF) using liver sections from a chimpanzee with NANBH. Twenty-seven cultures exhibited positive IF reactions similar to those observed with the original antibodies, 48-1 and S-1, and were cloned by limiting dilution. The specificities of the monoclonal antibodies were tested by IF on liver biopsy specimens from chimpanzees with hepatitis A, B, D or NANBH and from normal chimpanzees. All the antibodies proved to be IgG. Immunoelectron microscopy revealed that all 27 antibodies bound to the same structure, the microtubular aggregates, in hepatocytes of chimpanzees with NANBH. To determine the size of the antigen polypeptide recognized by these antibodies, polyacrylamide gel electrophoresis and Western blot assays were performed. Nine of the 27 antibodies specifically reacted with a single polypeptide of Mr 44K (p44). The remaining 18 antibodies detected no antigen polypeptide on the filters. The anti-p44 antibodies were then tested using cross-competition assays with 125I-labelled antibodies, and were found to be classifiable into three groups. In addition, the results indicate that at least three distinct epitopes are located on p44: epitope A recognized by group 1, epitope B recognized by group 2 and epitope C recognized by group 3.

Further observation on the intraepithelial nerve fibers of rabbit ocular ciliary epithelium

The intraepithelial nerve fibers of rabbit ciliary epithelium were observed under the electron microscope after administration of 5-hydroxydopamine. All the fibers so far observed contained small and large cored vesicles, thus indicating their noradrenergic nature.

Tris inhibits both proteolytic and oligosaccharide processing occurring in the Golgi complex in primary cultured rat hepatocytes

Tris caused the distention of the Golgi cisternae in primary cultured rat hepatocytes and perturbed the functions occurring there. Proteolytic cleavage of precursors of both albumin and complement C3 was inhibited, whereas that of prohaptoglobin was not affected by Tris. These effects on the proteolytic cleavages resemble those of acidotropic amines (Oda, K., and Ikehara, Y. (1985) Eur. J. Biochem. 152, 605-609; Oda, K., Koriyama, Y., Yamada, E., and Ikehara, Y. (1986) Biochem. J. 240, 739-745). However, the effects of Tris significantly differed from acidotropic amines on the basis of its effects on the processing of N-linked oligosaccharides of glycoproteins. Both alpha 1-protease inhibitor and haptoglobin secreted from the Tris-treated cells were found to contain almost equal amounts of endo-beta-N-acetylglucosaminidase H-sensitive and -resistant oligosaccharides, whereas the glycoproteins from both the control and methylamine-treated cells were resistant to the enzyme. The endo-beta-N-acetylglucosaminidase-sensitive oligosaccharides were analyzed to be Man8-5GlcNAc by high resolution gel permeation chromatography, suggesting that trimming of alpha-mannose residues from the precursor Man9GlcNAc2 is incomplete in the Tris-treated cells. On the other hand, Tris did not significantly inhibit incorporation of radioactive monosaccharides (N-acetylglucosamine, galactose, and fucose) into the glycoproteins. However, two-dimensional gel electrophoresis in combination with neuraminidase digestion demonstrated that sialylation was markedly inhibited by Tris. Taken together, our results reveal that Tris inhibits not only the sialic acid addition which takes place in the trans Golgi region, but also the trimming step of high mannose-type oligosaccharides, which is thought to occur before glycoproteins reach the trans Golgi region.

Lysosomal enzyme activities in the cerebral microvessels in spontaneously and renal hypertensive rats

In an attempt to clarify the role of lysosomal enzymes in the developmental mechanisms of the changes of cerebral microvessels under hypertensive conditions, the activities of acid phosphatase, N-acetyl-beta-glucosaminidase, and beta-glucuronidase in the isolated microvessels from the cerebral cortex of spontaneously and renal hypertensive rats were biochemically studied. The activities of all the enzymes were higher than those in normotensive control animals, although there was a variation in intensity according to the age and kind of enzymes. The enzyme activities in spontaneously hypertensive rats showed a tendency to increase with advancing age. Hypertension seems to increase activities of lysosomal enzymes in cerebral microvessels, and this activation may in turn play a role in the development of further hypertensive cerebrovascular and cerebral changes.

Intraepithelial nerve fibers in the rabbit ocular ciliary epithelium

Ciliary processes, mainly iridial processes, of the adult rabbit eye were examined by electron microscopy. Intraepithelial nerve fibers were recognized in the ciliary epithelium. These were single, naked unmyelinated nerve fibers found between pigmented epitheliocytes but not between non-pigmented epitheliocytes. They displayed a beaded structure and contained in their dilated portions many clear vesicles, a few cored vesicles and filamentous mitochondria. Their possible functional significance is discussed.

In vitro production of human antibodies specifically reactive with human gastric cancer cells of established lines and autologous tissues

Human lymphocytes derived from regional lymph nodes adjacent to the primary gastric cancer were transformed with Epstein-Barr virus (EBV) to establish lymphoblastoid cell lines secreting human antibodies reactive with cell surface antigens expressed on the gastric cancer cells. The EBV transformation technique was applied to lymph node lymphocytes obtained from 4 gastric cancer patients. As a result of mass screening with the radioactive cell binding assay for the production of anti-gastric cancer related antibodies, one culture (TGc-106) among 1,400 microcultures was identified to secrete human antibody specifically reactive with an established human gastric cancer cell line as target (MKN-45). Furthermore, it was demonstrated with the autologous assay system by the histoimmunofluorescence method that cell surface antigens of autologous gastric cancer cells could be clearly defined with human antibody from one culture (TEb-079) out of 470 microcultures established from a gastric cancer patient (GCP-26); there was no reactivity against the surrounding normal cells constructing the gastric wall. The immunoglobulin class of the human antibodies produced both in TGc-106 and TEb-079 was determined from immunodiffusion tests to be IgM.

Point mutation of alanine (31) to valine prohibits the folding of reduced lysozyme by sulfhydryl-disulfide interchange

In the preceding paper in this issue, we described the overproduction of one mutant chicken lysozyme in Escherichia coli. Since this lysozyme contained two amino acid substitutions (Ala31----Val and Asn106----Ser) in addition to an extra methionine residue at the NH2-terminus, the substituted amino acid residues were converted back to the original ones by means of oligonucleotide-directed site-specific mutagenesis and in vitro recombination. Thus, four kinds of chicken lysozyme [Met-1Val31Ser106-, Met-1Ser106-, Met-1Val31- and Met-1 (wild type)] were expressed in E. coli. From the results of folding experiments of the reduced lysozymes by sulfhydryl-disulfide interchange at pH 8.0 and 38 degrees C, followed by the specific activity measurements of the folded enzymes, the following conclusions can be drawn: (i) an extra methionine residue at the NH2-terminus reduces the folding rate but does not affect the lysozyme activity of the folded enzyme; (ii) the substitution of Asn106 by Ser decreases the activity to 58% of that of intact native lysozyme without changing the folding rate; and (iii) the substitution of Ala31 Val prohibits the correct folding of lysozyme. Since the wild type enzyme (Met-1-lysozyme) was activated in vitro without loss of specific activity, the systems described in this study (mutagenesis, overproduction, purification and folding of inactive mutant lysozymes) may be useful in the study of folding pathways, expression of biological activity and stability of lysozyme.

[A study on UFT concentration in tissues and serum of patients with malignant gynecologic tumors following oral administration]

UFT was orally given at a dose of 200 mg twice a day to seven female patients with malignant gynecological tumors. Measurements of blood and tissue concentrations of tegafur (TF), fluorouracil (FU) and uracil (U) showed that the concentrations of both FU and U were clearly increased. The ratio of concentration in the tumor to that in peripheral blood was 9.3, while that of the concentration in the internal iliac lymph nodes to that in the internal iliac artery was 11.2. The changes in blood levels of the three compounds were determined one and five days after UFT administration. There was a distinct difference in the blood levels of the drug among TF, FU and U. TF reached its peak concentration two hours after breakfast and four hours after supper; both FU and U reached their peak concentrations two hours after breakfast and one hour after supper. Furthermore, TF showed a tendency to accumulate after continuous administration, but this was not the case with FU or U. These findings suggest that even during continuous administration, the blood level of FU remains low.

A new solid-phase synthesis of oligoribonucleotides by the phosphoro-p-anisidate method using tetrahydrofuranyl protection of 2'-hydroxyl groups

Six nonaribonucleotides containing the 5'-splice site, one complementary nonamer and an octadecamer containing the 3'-splice site have been synthesized on a polymer support using the phosphoro-p-anisidate method. A 5'-linked 2'-O-tetrahydrofuranyl-N-protected nucleoside 3'-(o-chlorophenyl)phosphoro-p-anisidate was used as the starting nucleotide, and the chain elongated in the 3'-direction by removing the p-anisidate protecting group with isoamyl nitrite under neutral conditions. The octadecamer has been synthesized using dinucleotide blocks and a 3'-terminal trinucleotide.

Ultrastructure of the synaptic ribbons in photoreceptor cells of Rana catesbeiana revealed by freeze-etching and freeze-substitution

The three-dimensional structure of synaptic ribbons in photoreceptor cells of the frog retina was studied with freeze-etching and freeze-substitution methods, combined with a rapid-freezing technique. Although the synaptic ribbon consisted of two electron-dense plaques bisected by an electron-lucent layer in conventional thin sections, such lamellar nature was not so evident in freeze-etched replicas. The cytoplasmic surfaces of the synaptic ribbon presented an extremely regular arrangements of small particles 4-6 nm in diameter. Fine filaments 8-10 nm in diameter and 30-50 nm in length connected synaptic vesicles and the ribbon surface. These connections were mediated by large particles on both ends of the filaments. Approximately 3-5 filaments attached to one synaptic vesicle. Synaptic ribbons were anchored to a characteristic meshwork underlying the presynaptic membrane via another group of similar fine filaments. The meshwork seemed to be an etched replicated image of the presynaptic archiform density observed in thin sections.

Effects of weakly basic amines on proteolytic processing and terminal glycosylation of secretory proteins in cultured rat hepatocytes

We examined the effects of weakly basic amines on the secretion and post-translational modifications of secretory proteins in cultured rat hepatocytes. Weakly basic amines such as methylamine, chloroquine and NH4Cl strongly inhibited not only protein secretion, but also the proteolytic conversion of a proform of complement C3, allowing the precursor to be released into the medium. The amines, however, had no effect on the proteolytic conversion of prohaptoglobin into its subunits. Since available evidence indicates that the conversion of pro-C3 occurs at the Golgi complex while that of prohaptoglobin takes place in the endoplasmic reticulum, it is most likely that the weak bases specifically affect the proteolytic event occurring at the Golgi complex. Electron microscopic observations confirmed that the amines caused morphological changes of the Golgi complex, consisting of dilated cisternae and swollen vacuoles. When the glycosylation of alpha 1-protease inhibitor and haptoglobin was examined, it was found that the amines caused a marked accumulation in the cells of both glycoproteins corresponding to the mature secreted forms. Neuraminidase digestion demonstrated that the glycoproteins accumulating in response to the amines had acquired terminal sialic acid. The results indicate that the amines do not significantly affect terminal glycosylation, in contrast with their definite effect on proteolytic processing, despite the fact that both modifications take place in the Golgi complex.

Early changes of experimentally induced cerebral aneurysms in rats. Light-microscopic study

The changes of the anterior cerebral artery/olfactory artery junction, one of the favorite sites of aneurysm formation, in rats treated with unilateral ligation of the common carotid artery and renal hypertension were investigated by light microscopy. The initial changes of aneurysm occurred not at the apex itself, but on the distal side of the major branch adjacent to the apex, at the intimal pad and the neighboring distal portion. Here the internal elastic lamina showed various degenerative changes and disappearance. The neighboring distal portion adjacent to the intimal pad showed a shallow depression associated with a thinning of the media due to a decrease of medial smooth muscle cells in number even in some control animals. Such degenerative changes of the internal elastic lamina and medial smooth muscle cells caused by hemodynamic stress due to branching structure, including intimal pads, augmented by the experimental treatment, are supposed to be the basis for aneurysm formation.

Elastase, collagenase, and cathepsin D activities in the aortas of spontaneously hypertensive and renal hypertensive rats

In an attempt to clarify the roles of proteases in the developmental mechanisms of hypertensive vascular lesions, changes in activities of aortic elastase, collagenase, and cathepsin D in spontaneously hypertensive rats (SHR) and renal hypertensive rats were biochemically investigated. In SHR, elastase activity initially showed a significant increase, once two-fold higher than that in the control; but the activity tended to decrease earlier than that in the control. In both SHR and normotensive control rats collagenase activities tended to increase with advancing age. The activity in SHR was two-fold higher than that in the control at all ages examined. In both younger SHR and normotensive rats cathepsin D activities proved to be increased with advancing age, while in old rats the activities tended to decrease. The activity in SHR was three- to fivefold higher than that in the control at all ages examined. In renal hypertensive rats, the activities of elastase, collagenase, and cathepsin D increased gradually with increasing blood pressure, at levels significantly higher than those in the control. These findings suggest that the metabolisms of proteins such as elastin and collagen, expressed by these enzyme activities, are accelerated under hypertensive conditions.

[Clinical experience with aztreonam in the field of obstetrics and gynecology]

Aztreoman (SQ 26,776, AZT), a synthetic monobactam antibiotic, was applied clinically in the field of obstetrics and gynecology. AZT was administered by intravenous drip infusion for 6 to 8 days at a daily dose of 2 g divided in 2 times to 5 cases. Klebsiella in 1 case with puerperal endometritis, Enterococcus, Propionibacterium and Bacteroides in each 1 case with pyometra was isolated. The clinical effect of Klebsiella was excellent. Bacteroides in 1 not-examined case was good. Enterococcus and Bacteroides with pyometra was not effective. Side effects were observed in 2 cases. One case with eclampsia arised LDH and A1-P in serum and 1 case with hepatitis arised GOT and GPT in serum.

A light and electron microscopic study of lamellated nerve endings found in the rat cheek mucosa

Lamellated nerve endings in the cheek mucosa of fifteen adult Sprague-Dawley rats were studied with light and electron microscopes. Serial sections revealed that the terminal axon of the lamellated nerve endings is in the central portion, and that the inner core is made up of two stacks of lamellae. These are characterized by many corpuscles located within a single papilla, which shows structural specializations at several levels. Electron microscopy showed that the corpuscles are circular in shape and that the lamellar sheets possess a rich rough endoplasmic reticulum, mitochondria and numerous glycogen-like granules. Numerous bundles of collagen fibers and an amorphous substance are located in the interlamellar spaces. The axon terminal is characterized by the presence of neurofilaments, neurotubules and mitochondria. The capsule consists of several laminae formed by cytoplasmic extensions of perineural cells presenting many caveolae, mitochondria, rough endoplasmic reticulum profiles and microfilaments.

Effects of the lysosomal fraction of polymorphonuclear leukocytes on proliferation of cultured vascular cells

The effects of the lysosomal fraction isolated from polymorphonuclear leukocytes (PLF) on the growth of cultivated aortic medial smooth muscle cells (SMCs) and arterial endothelial cells (ECs) were studied by assaying DNA synthesis and counting the numbers of cells. PLF proved to promote the growth of cultivated SMCs and ECs. There was a positive correlation between an increase in DNA synthesis and the dose of PLF. The growth-promoting effect was observed in sparsely cultivated SMCs and ECs, in densely cultivated SMCs, but not in confluently cultivated ECs. The difference in response between SMCs and ECs seems to depend on their biological characteristics. Because a small amount of PLF showed potent growth-promoting activity in the presence of 10% fetal bovine serum which possesses a high protease blocking activity, the mechanism of this promoting activity is suggested to be independent of the proteases contained in PLF.

Changes of 5'-nucleotidase activity in cultured glioma cells

Changes of 5'-nucleotidase (5'-N) activity during subcultivation of C6 clonal rat glioma cells were studied histochemically, cytochemically and biochemically. Two different cell populations were seeded with high or low cell density respectively. 5'-N activity in cultured cells increased continuously in both populations. The enzyme activity was always higher in the cells growing in high density than in those growing in low density, and this difference became statistically significant after 6 days of subcultivation. It seemed likely that the increase in 5'-N activity depended on cell density, not on the frequency of mitosis. Cytochemically, enzyme activity was detected on the outer surface of the plasma membrane of cell bodies or cell processes. Strong activity was found on the processes and cell membranes where cells touched each other. In the regions where cells had intimate cell-to-cell contact, marked elevation of the enzyme activity was seen. Increased 5'-N activity, which appeared to depend on cell density, was considered to be related with this cell-to-cell contact.