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Biomedical subjects

H Ushijima

Publications and source records attributed to H Ushijima.

At least 145 records · Page 8Linked to original sources

Effect of N-(3-phenyl-2-propenyl)-1-deoxynojirimycin on the lectin binding to HIV-1 glycoproteins.

The effect of N-(3-phenyl-2-propenyl)-1-deoxynojirimycin (ppDNM) on the lectin binding to HIV-1 glycoprotein was analyzed by using biotinylated lectins of various sugar specificities as probes. ppDNM potentially inhibited HIV-1-induced syncytium formation and viral infectivity of HIV-1 without cytotoxicity. The lectin binding assay showed that ppDNM treatment reduced Con A binding to gp120 of HIV-1.

1-Deoxynojirimycin↗

Detection of anti-rotavirus IgG, IgM, and IgA antibodies in healthy subjects, rotavirus infections, and immunodeficiencies by immunoblotting.

Immune responses to individual simian rotavirus (SA 11) structural polypeptides were studied with emphasis on specific IgG, IgM, and IgA in paired sera from four children with rotavirus infections. Responses to simian rotavirus (SA 11) were also studied in 103 healthy children, 10 patients with primary immunodeficiency who received intravenous immunoglobulin, and 11 human immunodeficiency virus antibody-positive patients. All samples were immunoblotted for two major polypeptides--VP2 and VP6--of IgG. Immunoblotted IgA and IgM were elevated 2-4 weeks after the onset of the disease (stage II) in patients with rotavirus infection. Immunoblotted IgG remained almost the same at the onset of the disease and stage II. The scores for primary and secondary immunodeficiency patients were lower than for healthy children. The score obtained by totaling all polypeptides found in each individual was compared with the optical density (OD) value obtained by enzyme immunoassay.

Acquired Immunodeficiency Syndrome↗

Detection of group C rotaviruses in Tokyo.

Four human group C rotaviruses were detected in Tokyo in 1987 and 1988 during a survey over 7 years. Among the four rotaviruses, two electrophoretic patterns were indicated by polyacrylamide gel electrophoretic (PAGE) analyses. Clinical symptoms, signs, family history, and patients' ages varied. Group C rotaviruses were found also in other parts of Japan in 1988. It was suspected that group C rotaviruses would continue to spread throughout Japan within the near future.

Blotting, Western↗

Detection of anti rotavirus coproantibodies by immunoblotting technique.

IgA and IgG coproantibodies to individual simian rotavirus (SA 11) structural polypeptides were detected in healthy infants in nursery homes. The number of immunoblottable peptides differed from individual to individual. Coproantibodies were also detected at the convalescent stage of rotavirus infection in two patients but not during the acute stage. This method is useful for confirming the diagnosis of rotavirus infection serologically without the need for paired sera.

Antibodies, Viral↗

Effects of pH and ionic strength on the binding of egg white riboflavin binding protein with flavins.

The effects of pH and ionic strength on the equilibrium constants and rate constants (binding and dissociation rate constants) between riboflavin binding protein (RBP) and flavins (riboflavin, 3-carboxymethylriboflavin [CMRF], and FMN) were studied by fluorometry. The equilibrium constant and the binding rate constant between RBP and riboflavin were pH-independent between pH 6 and 9, and both constants were also independent of the ionic strength, while the constants between RBP and CMRF or FMN were dependent on both pH and ionic strength. The dissociation rate constants between RBP and the flavins used here were not so dependent on pH and ionic strength in the pH region 6 to 9, and the patterns of pH profiles as a whole were similar to each other, although the constants for FMN were about 30-60 times larger than those for CMRF or riboflavin. RBP had lower affinity for FMN than for riboflavin in the neutral pH region, which is based on the small binding rate constant and the large dissociation rate constant for FMN. The former is due to an electrostatic repulsion force between negative net charges of RBP and the phosphate group of FMN, and the latter is due to steric interference by the phosphate group of FMN.

Animals↗

[Epidemiology of rotavirus infection around Tokyo area].

Epidemiology of rotavirus infection was studied from 1981 to 1988 mainly in three hospitals around Tokyo area. Major serotypes of rotaviruses in the three places were different from those in two hospitals around Kansai area in Japan (Ref. 6, 13), while, major serotypes were same among three hospitals. Both of serotypes 1 and 4 in group A were mostly found around Tokyo area. Frequencies of type 2, 3, and 9 in group A were low, although the frequencies were various among periods. Detail examinations of rotavirus RNA electropherotypes showed the results as follows; different electropherotypes were found during one winter season and at one hospital, the identical electropherotype was found cross a year and cross a hospital. We could not find the identical electropherotype which belong to two serotypes so far. Seven group C rotaviruses were found since 1987 in three hospitals. It would be important to examine RNA electropherotypes and serotypes for long period not only for epidemiological studies but also for development of vaccine.

Humans↗

[Clinical application of subrenal capsule assay in ovarian cancer].

The 6-day subrenal capsule assay (SRC) in normal immuno-competent mice was used to test the responsiveness of ovarian cancer to combination chemotherapy and assess the usefulness of SRC in clinical application. A total of 18 different patients in 22 different assays were studied. Twenty-one assays (95%) were evaluable. The predictive sensitivity was 50%, the predictive resistance 75% and the predictive total accuracy 55% respectively. Sensitive drugs in repeated assays in four patients were not changed. Etoposide, cyclophosphamide, cis-platin and adriamycin were sensitive. Etoposide was the most sensitive of four drugs. The response rate was 50% in the patients treated with etoposide as the first line chemotherapy and the second line chemotherapy, respectively. Patients who were treated with sensitive drugs in SRC survived longer than the patients treated with cis-platin combined chemotherapy without etoposide. The median survival time was 19 months and the mean progression free interval was 15 months. In the results of this study, the value of SRC was supported by the results of chemosensitivity tests and etoposide seems useful in chemotherapy in ovarian cancer.

Adult↗

Intracerebroventricular injection of neosurugatoxin induces a prolonged blockade of brain nicotinic acetylcholine receptors.

The intracerebroventricular injection of neosurugatoxin (2 x 3.2 micrograms) significantly reduced the specific binding of [3H]nicotine but not of [3H]cismethyldioxolane in the cerebral cortex, hippocampus and thalamus of rats 3 days after the toxin injection. Scatchard analysis of [3H]nicotine binding in the rat cerebral cortex revealed that neosurugatoxin can selectively decrease the maximal binding sites (Bmax) for [3H]nicotine by approximately 38%. A significant decrease in the Bmax value for [3H]nicotine was also observed in this brain region 7 days after the neosurugatoxin injection. Thus, the intracerebroventricular injection of neosurugatoxin can induce a prolonged blockade of brain nicotinic acetylcholine receptors.

Animals↗

A study of adenovirus gastroenteritis in the Tokyo area.

Probable serotypes of faecal adenoviruses 40, 41, 31, 2 and 1 were found in the Tokyo area by rapid DNA restriction endonuclease analyses directly of stool specimens or after primary culture in Graham 293 cells. Some variations were found in both adenoviruses 40 and 41 by this method.

Adenoviridae↗

Enhancement of peptidergic synaptic transmission by catecholamines in the bullfrog sympathetic ganglion.

Extracellular recordings were made from postganglionic branches or ganglion cells of the 9th or 10th ganglia of the paravertebral sympathetic chain of the bullfrog in vitro. Tetanic preganglionic stimulation, applied to nerve fibers between the 7th and 8th ganglia, elicited cholinergic (muscarinic) and non-cholinergic synaptic responses in nicotinized preparations. These were an early after-discharge (EAD) and a late after-discharge (LAD), respectively. Brief application (3-10 min) of catecholamines augmented the LAD and this augmentation continued for 90-120 min after catecholamine withdrawal. In contrast, these catecholamines did not significantly augment the EAD. The catecholamine effects were concentration-dependent within the range 1-100 microM, and the order of the potency was isoprenaline greater than adrenaline greater than noradrenaline greater than dopamine = phenylephrine. The catecholamine-induced augmentation was blocked by propranolol (0.1-1 microM) and pindolol (1-10 microM), but not by phentolamine (up to 10 microM). The catecholamine-evoked augmentation of the LAD could be mimicked by dibutyryl cyclic adenosine 3',5'-monophosphate (dbc-AMP) at 1-50 microM. However, similar concentrations of cyclic adenosine 3',5'-monophosphate (c-AMP), cyclic guanosine 3',5'-monophosphate (c-GMP) and dibutyryl c-GMP (dbc-GMP) had no effect. None of cyclic nucleotides appreciably augmented the EAD. Methylxanthines, 3-isobutyl-1-methylxanthine and caffeine, facilitated the LAD and potentiated the isoprenaline-induced augmentation of the LAD. The excitatory actions of luteinizing hormone releasing hormone (LHRH) were also enhanced by (-)-isoprenaline and dbc-AMP. The former was prevented by propranolol.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Methyl-3-isobutylxanthine↗

Genome variants of human adenovirus types 40 and 41 (subgroup F) in Japan.

Nineteen strains of fecal adenovirus were typed as adenovirus type 40 (Ad40) by restriction enzyme analysis of the DNA, using SmaI. The DNAs of the strains were further compared by digestion with four other enzymes, namely, HindIII, EcoRI, BglI, and BamHI. At least two different restriction profiles were found to exist for BamHI. Of the 19 strains studied, 17 had the same combination of profiles for all of the enzymes. Thirteen strains of fecal adenovirus were typed as Ad41 by restriction enzyme analysis of the DNA, using SmaI. The DNAs of the strains were further compared by digestion with four other enzymes, as for Ad40. At least two different restriction profiles were found to exist for each enzyme. Of 13 strains, 9 had the same cleavage sites for all of the enzymes, indicating a close relationship. Two strains were genome variants which deviated from the common genome on digestion of the DNA with HindIII. One strain was a genome variant which deviated from the common genome on digestion of the DNA with HindIII and EcoRI. The last one had a combination of restriction sites which was not identical to those of other strains on digestion of the DNA with SmaI. All 13 Ad41 strains studied were easily distinguished from Ad40 strains by using any of the five restriction enzymes.

Adenoviruses, Human↗

Brain nicotine cholinoceptor binding in spontaneous hypertension.

To study the role of central cholinergic mechanisms in hypertension, we have determined nicotinic and muscarinic agonist binding sites in the brain regions of stroke-prone spontaneously hypertensive rats (SHRSP), using [3H]nicotine and [3H]cismethyldioxolane (CD). There was a significant decrease in specific [3H]nicotine binding in the cerebral cortex, thalamus, midbrain, cerebellum and medulla oblongata of SHRSP at 16-24 weeks of age compared to that of age-matched Wistar Kyoto rats (WKY). Scatchard analysis revealed 35% decrease in the Bmax value for [3H]nicotine binding in the SHRSP medulla oblongata without a change in the Kd value, suggesting a change in the receptor density. Similar reduction of nicotinic cholinoceptor binding sites was also observed in the discrete brain regions of young (5-week-old) SHRSP. In contrast, there was no alteration in specific [3H]CD binding in the SHRSP brains regions, except the hypothalamus which showed a significant increase. The SHRSP medulla oblongata showed no change in the ChAT activity. Thus, the present study suggests an important role for medullary nicotinic cholinoceptors in the pathogenesis of spontaneous hypertension.

Animals↗

Kinetic and equilibrium studies on the interaction of reduced flavoprotein D-amino acid oxidase with pyridine carboxylates.

The equilibrium constants and the rate constants (binding and dissociation constants) between reduced D-amino acid oxidase and pyridine carboxylates were obtained at various pH values (from pH 6.0 to 8.3). The pH dependence of the constants is consistent with the previous conclusion from a resonance Raman study that pyridine carboxylates in the form of a cation protonated at the N atom can bind to the reduced enzyme, but those in the neutral form cannot bind, showing that the positive charge of cationic pyridine carboxylates interacts with the negative charge of the anionic reduced flavin in the reduced enzyme. The binding rate constants of picolinate and nicotinate in the cationic form for the reduced enzyme were quite similar to each other, but the dissociation rate constant of picolinate is several times smaller than that of nicotinate. Thus, it is concluded that the difference in affinity of picolinate and nicotinate for the reduced enzyme is derived from the difference of the dissociation rate constants.

Animals↗