Biomedical subjects
Publications and source records attributed to T Taniguchi.
Wheat germ RNA polymerase II is poly (ADP-ribosyl)ated in vitro by poly (ADP-ribose) synthetase purified from bovine thymus. RNA polymerase activity is decreased by 40% by the modification in conventional assays.
Vero cells (African green monkey kidney in origin) were prepared by the conventional air-drying method and then processed for SEM by a modification of the conductive method based on thiocarbohydrazide-osmium binding. Under SEM, not only metaphase chromosomes but also resting nuclei showed distinct fibres 30 nm in diameter. A few such fibres were found to run across the secondary constriction of the NOR-carrying chromosome.
Mouse interferon-beta (IFN-beta) cDNA, whose signal sequence had been removed by BAL 31 digestion, was introduced into a Bacillus subtilis secretion vector constructed by using the promoter and signal sequence of the B. subtilis alpha-amylase gene. The resultant chimeric plasmids were transferred into B. subtilis 207-25. Four kanamycin-resistant transformants were selected by both colony hybridization and a new immunoblot method for secretory proteins. They secrete the proteins which cross-react with sheep anti-mouse IFN-beta serum into the culture medium. One of them expressed a high IFN-beta activity as assayed by the L cell and vesicular stomatitis virus system, while the other three showed weak or little IFN activities. Based on our previous study [Ohmura et al., Nucl. Acids Res. 12 (1984) 5307-5319], it was suggested that the secreted IFN molecules are hybrid proteins in which the NH2-terminal region consists of part of the alpha-amylase signal peptide. Nucleotide sequence analysis revealed that plasmid pTUB502, which expressed high IFN activity, is joined to the mouse IFN-beta gene from the codon position 6 of its mature protein. The other three plasmids, pTUB506, pTUB509, and pTUB519, contain the mouse IFN-beta gene from the codon positions 3, 1, and -5, respectively. The NH2-terminal region of the mouse IFN-beta seems to be closely related to its biological activity.
The human interferon-beta (IFN-beta) gene contains sequences within its 5'-flanking region that mediate the virus-induced activation of mRNA transcription. A series of mutant IFN-beta genes, including the 5' deletion mutants, was constructed and introduced into mouse L929 cells. Expression study of those mutant genes demonstrates that: sequences upstream, but not downstream, of -40 from the cap site are responsible for the viral induction of the gene; that the upstream boundary of the DNA sequences required to support the maximum level of induction lies between -117 and -105 from the cap site; and that this upstream sequence shows a property similar to enhancer elements as it functions in either orientation with a latitude in distance from the cap site. Within this sequence, we note the presence of repetitious hexanucleotides (consensus: A-A-AG-TG-G-A), each of which may play a role in the maximum induction of the IFN-beta gene.
When the mouse lymphoma (L-1210) cells are treated with methylnitrosourea (MNU) at 37 degrees C for 30 min and then cultured for 4 h in a normal medium nuclear structure and functions of the cells are changed. We have investigated the mechanism as to how nuclear structure and functions are changed by MNU. In MNU-treated cells euchromatin area diminishes and chromatin condensation occurs. [3H]thymidine and [3H]uridine uptakes of the MNU-treated cells decrease. In contrast, when the MNU-treated cells are cultured in the presence of 3-aminobenzamide, a specific inhibitor of poly(ADP-ribose) synthetase changes of nuclear structure do not appear. [3H]Thymidine and [3H]uridine uptakes are partially and almost completely recovered, respectively. Autoradiographs of the cells labelled with [3H]NAD, a substrate of poly(ADP-ribose) synthetase show that silver grains due to [3H]ADP-ribose are densely located only in the cells where chromatin condensation occurs. Chromatin-bound proteins of molecular masses 20-25 X 10(3) daltons are specifically poly(ADP-ribosyl)ated in the MNU-treated cells. These results suggest that MNU-induced chromatin condensation is caused by poly(ADP-ribosyl)ation of chromatinbound proteins.
Cathepsins B and H from rat liver contain one asparagine-linked sugar chain in each molecule. The sugar chains were liberated from the polypeptide portions by hydrazinolysis followed by N-acetylation and NaB3H4 reduction. Paper electrophoresis of the radioactive oligosaccharide fractions revealed that they were mixtures of neutral oligosaccharides only. After fractionation by gel filtration the structure of each oligosaccharide was studied by sequential exoglycosidase digestion in combination with methylation analysis. The sugar chain of cathepsin H was a high mannose type oligosaccharide which varied in size from 5 to 9 mannose residues; on the other hand the major oligosaccharide of cathepsin B was a tetrasaccharide whose structure was Manalpha 1----6Manbeta 1----4GlcNAcbeta 1----4GlcNAc.
The neurogenic responses of cerebral arteries of humans and the monkey were compared with those of the dog. alpha-Adrenoceptors in these cerebral arteries were also characterized by radioligand-binding studies. In human posterior communicating arteries, the contractile response to electrical transmural stimulation was attenuated by treatment with phentolamine in 41% of preparations tested, but not affected by aspirin. The responses in the monkey and canine arteries were not attenuated by treatment with phentolamine, but were reduced by aspirin in 60 and 73% of the cases, respectively. Reactivity and affinity to exogenous noradrenaline were comparable in human and monkey arteries, but greater than those of canine arteries. Radioligand-binding assays revealed binding sites for [3H]prazosin in the human and monkey cerebral arteries; the KD and Bmax values were not significantly different between the two species. Such binding sites were not detected in canine arteries. Binding sites for [3H]yohimbine were present in the arteries of the three species. Thus, the neurogenic contractile response of human cerebral arteries may be at least in part adrenergic in nature, while that of monkey and canine arteries may be due to neurogenically occurring arachidonate. alpha-Adrenoceptors in the monkey arteries are similar to those in humans.
(-)-[3H]Nicotine was found to bind specifically to membranes of human brains obtained at autopsy. The binding was stereospecific, (-)-nicotine being 40 times more potent than (+)-nicotine in displacing labeled (-)-nicotine. Saturation binding studies revealed the presence of two binding sites with dissociation constant (KD) values of 8.1 and 86 nM, and maximum binding capacity (Bmax) values of 36 and 90 fmol/mg protein, respectively. In competition studies, nicotinic agonists were 1,000 times more potent than ganglionic, neuromuscular, and muscarinic blocking drugs in displacing labeled (-)-nicotine. IC50 values for cholinergic drugs of (-)-[3H]nicotine binding were as follows: (-)-nicotine, 0.51 nM; acetylcholine, 12.6 nM; (+)-nicotine, 19.9 nM; cytisine, 27.3 nM; and carbachol, 527 nM. IC50 values of alpha-bungarotoxin, hexamethonium, d-tubocurarine, and atropine were larger than 50 microM. (-)-[3H]Nicotine binding was highest in the nucleus basalis of Meynert and thalamus and lowest in the cerebral cortex and caudate in the brain regions tested. These results suggest that nicotinic cholinergic receptors are present in human brain and that there are regional differences in the density of these receptors.
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Two grams of Cefoperazone was intravenously administered twice a day for 5 days by drip infusion to 10 donors and 9 recipients after renal transplantation. The concentration of cefoperazone in the blood after administration in both donors and recipients did not show any accumulation tendency. The urinary recovery rate of cefoperazone for 24 hours in donors was 8.8% and that in recipients was 8.1%. There was no change in the renal function in donors after administration of cefoperazone. No change was observed in blood examination, BUN or creatinine, but S-GOT and S-GPT showed a temporary increase in 1 donor and 1 recipient. It is considered that Cefoperazone is a very useful drug for prophylactic chemotherapy after renal transplantation.
Urological complications occurred in 17.5% of the 80 patients who had received renal transplantations in our clinic between March, 1975 and May, 1984. Urinary fistulas occurred in 3 patients, urolithiasis occurred in 6 patients, ureteral stenosis occurred in 1 patient and urinary tract bleeding occurred in 4 patients. Graft loss was observed in 1 patient, but there were no patients whose death was directly attributable to urological complications. Urological complications can be avoided by careful procedures in donor nephrectomy and urinary tract reconstruction.
Human chorionic gonadotropin (hCG) highly purified from the urine of patients with trophoblastic diseases (choriocarcinoma and hydatidiform mole) and from healthy pregnant women contains four asparagine-linked sugar chains in one molecule. Comparative studies of the sugar chains released by hydrazinolysis revealed that the structures of the sugar chains of choriocarcinoma hCGs are quite different from those of mole and normal hCGs. The carbohydrate structures of mole hCGs are the same as those of normal hCG, while all choriocarcinoma hCGs examined contain two triantennary, two unusual biantennary, and one monoantennary complex-type sugar chains which are not found in normal hCGs. The triantennary and unusual biantennary sugar chains contain the +/- NeuAc alpha 2----Gal beta 1----4GlcNAc beta 1----4Man alpha 1----3 group in common. The total amounts of fucosylated sugar chains in choriocarcinoma hCGs are twice those found in the hCGs of other groups. Therefore, the appearance of the N-acetylglucosaminyl transferase responsible for the formation of the GlcNAc beta 1----4Man alpha 1----3 group and the increase of the fucosyl transferase responsible for the formation of the Fuc alpha 1----6 GlcNAc----Asn group appear to be specific characteristics of malignant transformation of the trophoblast, and the structural changes of sugar chains could serve as useful markers for the diagnosis of choriocarcinoma.
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We report 4 patients with surgically proved idiopathic retroperitoneal fibrosis. Retroperitoneal fibrosis was diagnosed correctly in 3 of the patients by computerized tomography. On the computerized tomogram, retroperitoneal fibrosis demonstrated a characteristic soft tissue mass enveloping the vessels and ureters. In 2 patients, the follow-up computerized tomogram revealed spontaneous resolution of the mass in the retroperitoneal space. Computerized tomography is one of the most useful methods in the preoperative evaluation and postoperative follow-up of this disease.