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Biomedical subjects

M Ando

Publications and source records attributed to M Ando.

At least 937 records · Page 52Linked to original sources
PubMed1987

Glycosylation affects cleavage of an H5N2 influenza virus hemagglutinin and regulates virulence.

Based on nucleotide sequence analysis of the hemagglutinin (HA) gene from the virulent and avirulent A/chicken/Pennsylvania/83 influenza viruses, it was previously postulated that acquisition of virulence was associated with a point mutation that resulted in loss of a glycosylation site. Since there are two potential glycosylation sites in this region of the HA molecule and since all Asn-Xaa-Thr/Ser sequences in the HAs of different strains are not necessarily glycosylated, the question remained open as to whether either one of these sites was glycosylated. We now provide direct evidence that a site-specific glycosylation affects cleavage of the influenza virus HA and thus virulence. We have identified the glycosylation sites on the HA1 subunit from the virulent and avirulent strains by direct structural analysis of the isolated proteins. Our results show that the only difference in glycosylation between the HA1s of the virulent and avirulent strains is the lack of an asparagine-linked carbohydrate on the virulent HA1 polypeptide at residue 11. Further, we show that the HA1s of both the avirulent and virulent viruses are not glycosylated at one potential site, while all other sites contain carbohydrate. Amino acid sequence analysis of the HA1 of an avirulent revertant of the virulent strain confirmed these findings.

Amino Acid Sequence↗
PubMed1987

Minute carcinoid tumor of the uterine cervix associated with microinvasive adenocarcinoma, with reference to its histogenesis.

A rare case of carcinoid tumor of the uterine cervix associated with adenocarcinoma was reported. The carcinoid tumor was composed of round to polygonal cells showing solid or trabecular proliferation. Most of these cells and a small number of isolated cells wedged in neoplastic glands were positive with either Grimelius or Fontana-Masson stains, and also positive for serotonin by immunostain (PAP method). Positively stained cells were thus considered to have the same histochemical nature as enterochromaffin cell. The carcinoid tumor was minute, about 2 X 2 mm and the adenocarcinoma was a microinvasive one. In some parts, smooth transition between both tumor components was observed. From these findings, it is suggested that both the carcinoid tumor and the adenocarcinoma in the present case were derived from a primitive precursor cell of common mesodermal origin.

Adenocarcinoma↗
PubMed1987

Effect of exogenous gangliosides on amino acid uptake and Na+, K+-ATPase activity in superior cervical and nodose ganglia of rats.

The effects of some gangliosides on active uptake of nonmetabolizable alpha-aminoisobutyric acid (AIB) and Na+, K+-ATPase and Ca2+, Mg2+-ATPase activities in superior cervical ganglia (SCG) and nodose ganglia (NG) excised from adult rats were examined during aerobic incubation at 37 degrees C for 2 h. In NG, amino acid uptake was greatly accelerated with the addition of galactosyl-N-acetylgalactosaminyl-[N-acetylneuraminyl]-galactosylgluc osyl ceramide (GM1) (85%) and also with N-acetylgalactosaminyl-[N-acetylneuraminyl]-galactosylglucosyl ceramide (GM2) or [N-acetylneuraminyl]-galactosyl-N-acetylgalactosaminyl-[N-acetyl- neuraminyl]-galactosylglucosyl ceramide (GD1a) (43% each) compared with a nonaddition control at a 5 nM concentration. Under identical conditions, Na+, K+-ATPase activity was strongly stimulated with GM1 (180%) and GD1a (93%), whereas Ca2+, Mg2+-ATPase activity showed no change. In SCG, on the other hand, AIB uptake was apparently inhibited (-27%) by addition of GM1, with a slight decrease in Na+, K+-ATPase but no change in Ca2+, Mg2+-ATPase activity in the tissue. Both asialo-GM1, in which N-acetylneuraminic acid is deficient, and Forssman glycolipid, which is not present in nervous tissue, failed to produce any significant increase in both SCG and NG not only in amino acid uptake, but also in Na+, K+-ATPase activity. A kinetic study of active AIB uptake showed that GM1 ganglioside produced an increase in Km with no change in Vmax in SCG, whereas it caused a decrease in Km with a slight increase in Vmax in NG. Treatment of NG and SCG with neuraminidase from Vibrio cholerae, an enzyme that split off sialic acid from polysialoganglioside, leaving GM1 intact, caused little inhibition of the amino acid uptake.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1987

Retrograde transport of endogenous nerve growth factor in superior cervical ganglion of adult rats.

The concentration of naturally synthesized nerve growth factor (NGF) was measured in various tissues of adult rats, using a highly sensitive two-site enzyme immunoassay. The highest concentration was found in the superior cervical sympathetic ganglion (SCG). Transection of the postganglionic external carotid nerve (ECN) reduced the ganglionic level of NGF more than did section of the internal carotid nerve (ICN). When both the preganglionic nerve and the ECN were cut, the ganglionic NGF level decreased even more. On the other hand, when the preganglionic nerve and the ICN were both sectioned, leaving the ECN intact, endogenous NGF content in the SCG was significantly enhanced 3-9 h after operation. Bilateral extirpation of submaxillary gland produced a rapid decrease in ganglionic NGF 3-6 h after operation, and even unilateral removal of one salivary gland caused a decrease in both ganglia, which was however much greater in the ipsi- than in the contralateral ganglion. Removal of the eyeballs caused a much smaller reduction in ganglionic NGF than did removal of the glands. These results suggest that the endogenous NGF that accumulates in the SCG is mostly synthesized in the submaxillary gland rather than in the iris, and that it is transported to the SCG, mostly via the ipsilateral ECN.

Animals↗
PubMed1987

Effects of extracellular choline concentration and K+ depolarization on choline kinase and choline acetyltransferase activities in superior cervical sympathetic ganglia excised from rats.

The activities of choline kinase (CK) and choline acetyltransferase (ChAT) were examined in vitro in superior cervical sympathetic ganglia (SCG) excised from rats following aerobic incubation for 1 h in a medium containing various choline concentrations, with and without application of a high KCl level (70 mM). Ganglionic CK activity was strongly inhibited (by approximately 75%) at low extracellular choline concentrations (1-5 microM) but rose as the choline concentration was raised to 10-50 microM in the incubation medium, then fell and rose again with further increases in choline concentration. A similar but moderate accelerative effect on ganglionic CK activity was also observed after addition of acetylcholine (ACh; 1 mM) without eserine. Whereas specific CK activity did not change significantly in axotomized SCG, in which the ratio of glial cells to neurons is greatly increased for a week after the operation., it was remarkably increased after denervation, in which the preganglionic cholinergic nerve terminals had degenerated. When either a high KCl level or hemicholinium-3 (HC-3; 50 microM) was added to the medium in the presence or absence of choline, ganglionic CK activity was markedly inhibited. On the other hand, ChAT activity in the SCG remained at a significantly high level during incubation with low choline concentrations (1-10 microM), but the enhanced enzyme activity became inhibited as the extracellular choline concentration was raised to 50-100 microM in the medium. Addition of HC-3 to the medium did not alter ganglionic ChAT activity at low choline concentrations. However, application of quinacrine (10 microM) considerably reduced ganglionic CK activity and also suppressed ChAT activity induced by high KCl levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Protective effect of vitamin E against lipoperoxides in developing rats.

Pregnant rats were fed a vitamin E-supplemented diet, and blood and liver tissue concentrations of lipoperoxides were determined in fetuses and newborn rats. For comparison, a standard diet and a vitamin E-deficient diet were given to different animal groups. Fetal rats of all three groups showed very low blood and liver tissue levels of lipoperoxides, and there were no apparent intergroup differences. However, the levels increased sharply immediately after birth in the vitamin E-deficient rats, with the blood level being 4 times greater than in the other groups 10 days after birth, and the liver level 6 times greater than in the other groups 3 days after birth. Thus, vitamin E was revealed to be an important protective factor against abnormal synthesis and accumulation of lipoperoxides in liver tissues, particularly during the early stages after birth.

Aging↗
PubMed1987

Lipid peroxidation and vitamin E levels during pregnancy in rats.

The present study examined pregnancy-related changes in the level of lipoperoxides and antioxidative substances such as superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px) and vitamin E in the maternal and fetal serum, liver, lungs, and placenta using Wistar rats. Pregnant rats fed a standard diet (control animals) showed an increase of lipoperoxides in the blood to a level 3 times greater than the non-pregnant level. When the rats were fed a vitamin E-deficient diet, lipoperoxides were produced in much greater amounts. Fetal blood also contained greater concentrations of lipoperoxides by the use of a vitamin E-deficient diet. However, liver and lung tissues contained lipoperoxides in essentially constant concentrations throughout non-pregnancy and pregnancy. Fetal liver and lung tissues showed higher concentrations than the maternal concentrations. Fetal blood and tissue concentrations of vitamin E reflected the maternal concentrations, and the values in vitamin E-deficient animals were as small as 0.1-0.2 of the values in normally fed animals. As a protective factor against lipid peroxidation, SOD was slightly increased in the liver tissues of pregnant control animals, but catalase and GSH-Px were significantly decreased in the organ. A similar tendency was observed in vitamin E-deficient animals.

Animals↗
PubMed1987

Receptor-mediated O2- release by alveolar macrophages and peripheral blood monocytes from smokers and nonsmokers. Priming and triggering effects of monomeric IgG, concanavalin A, N-formyl-methionyl-leucyl-phenylalanine, phorbol myristate acetate, and cytochalasin D.

Receptor-mediated superoxide (O2-) release by alveolar macrophages and peripheral blood monocytes from smokers and nonsmokers was studied in vitro. When the cells were incubated with monomeric IgG or monomeric Fc(IgG) fragment, no cell O2- release was observed. However, when cytochalasin D (Cyto D) was subsequently added to the cell suspension, we observed a markedly enhanced O2- release. Neither Cyto D alone nor the double stimulation of following Cyto D with monomeric IgG induced O2- release. Concanavalin A (Con A) also had a priming effect on O2 release in combination with Cyto D, as did monomeric IgG or monomeric Fc(IgG) fragment. On the other hand, heat-aggregated IgG, N-formyl-methionyl-leucyl-phenylalanine (FMLP), or phorbol myristate acetate (PMA) induced O2- release without the addition of Cyto D. Thus, we observed 2 different mechanisms in the receptor-mediated O2- release by alveolar macrophages and peripheral blood monocytes. Alveolar macrophages from smokers, which had a higher affinity and a larger number of monomeric IgG binding sites per cell than those from nonsmokers, were more reactive to the double stimulation of following monomeric IgG with Cyto D than to that of Con A and Cyto D, FMLP, or PMA, but for peripheral blood monocytes it was the reverse. We conclude that the binding of monomeric IgG to the Fc(IgG) receptor of alveolar macrophages or peripheral blood monocytes results in a priming effect on the cells for O2- release, and that the regulation of receptor-mediated O2- release by alveolar macrophages differs at least in part from that of peripheral blood monocytes.

Adult↗
PubMed1987

Pathophysiological role of thyroid blocking antibody in patients with primary hypothyroidism.

The pathophysiological role of thyroid blocking antibody (TBAb) in patients with adult primary hypothyroidism and the mechanism of TBAb action were studied. A sensitive bioassay for TBAb, which inhibits the TSH-induced cAMP accumulation, was established using normal human thyroid cells in culture. Thirty-four patients with primary hypothyroidism consisting of 17 goitrous and 17 non-goitrous patients were examined. Two out of 17 goitrous patients (11.8%) and three out of 17 non-goitrous patients (17.6%) were TBAb positive. There were no significant differences between TBAb positive and negative patients in terms of the severity of hypothyroidism or the titers of MCHA or TGHA. Four out of the five TBAb-positive IgGs had strongly positive thyrotropin binding inhibitor immunoglobulin activities. All five TBAb-positive IgGs inhibited the cAMP increase induced by Graves' IgG, but did not affect the action of either prostaglandin E1 or cholera toxin. However, three TBAb positive IgG also inhibited the cAMP increase induced by forskolin. These findings indicate: 1) TBAb is present in hypothyroid patients with autoimmune thyroiditis and TBAb may play a role in the pathophysiology of these patients. 2) TBAb may inhibit the action of TSH not only at the level of the TSH receptor, but also at a different site from the TSH receptor.

Adolescent↗
PubMed1987

Impaired function of polymorphonuclear leukocytes exuded into bronchoalveolar spaces infected with Pseudomonas aeruginosa in steroid-treated rabbits.

Steroid-treated and untreated rabbits were infected transbronchially with Pseudomonas aeruginosa. The polymorphonuclear leukocytes (PMN) exuded into the bronchoalveolar spaces were obtained by lavage 18 hr later, superoxide (O2-) production and chemotactic activity were studied. In the steroid-treated group, there was a heightened susceptibility to the infection, as compared to findings in the untreated group. The lung exudate PMN in the steroid-treated group showed a significant decrease (p less than 0.05) in O2- production, and somewhat depressed chemotactic activity. In the untreated group, both O2- production (p less than 0.01) and chemotactic activity (p less than 0.001) of lung exudate PMN doubled, compared with findings in blood PMN. There was, however, no significant difference between lung exudate PMN and blood PMN in the steroid-treated group. Impaired PMN function in the steroid-treated group was also observed in case of casein-induced lung exudate PMN. These results suggest that the antibacterial function of PMN exuded in the infected lung may be impaired in steroid-treated hosts, hence an enhanced susceptibility to lung infection.

Animals↗
PubMed1987

[Manifestation of mictional disturbance in four cases of von Recklinghausen's disease].

Four patients with neurofibromatosis (von Recklinghausen's disease) manifesting mictional disturbance are presented. They were a man aged 41 years (A) and 3 women aged 26 (B), 46 (C) and 32 (D) years, and their chief complaints included urinary retention, dysuria, urinary frequency and urinary retention. None of them had any organic obstructive disorders in the lower urinary tract. Case A who had neurofibroma at the C2 and L1-2 vertebral bodies had inactive bladder and his urinary flow rate was less than 10 ml/sec. In case B, cystometrogram was initially normal, but changed to inactive bladder type one year later and neurofibromas were found in the vertebral bodies of Th7-8 and L2. Case C, who had inactive bladder cystometrically, underwent removal of 1-acoustic neurinoma and neurinomas of cauda equina. Case D had hyperactive bladder and received resection of the neurofibroma of vertebral bodies from C6 to Th4. The finding of cystometrogram and type of urinary miction disorders suggested vertebral neurofibroma at an early stage.

Adult↗