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Biomedical subjects

A Furuya

Publications and source records attributed to A Furuya.

At least 73 records · Page 4Linked to original sources
PubMed1984

A comparison of the inhibitory effects of ketotifen and disodium cromoglycate on bronchial responses to house dust, with special reference to the late asthmatic response.

Ten patients with allergic asthma were studied to compare the inhibitory effects of ketotifen and disodium cromoglycate on bronchial responses, especially the late asthmatic response, induced by house dust allergen in bronchial provocation tests. In the first study, types of bronchial response to house dust challenge were classified from peak expiratory flow rate measurements made at intervals after the test. Nine patients showed dual asthmatic response (immediate with isolated late response) and 1 patient showed isolated late asthmatic response. The tests were treated at 1-week intervals, patients having been premedicated from the night before the test with either ketotifen (3 X 2 mg oral doses) or disodium cromoglycate (3 X 40 mg by inhalation). The results showed that both drugs produced significant protection against the immediate bronchial response and that ketotifen was at least as effective as disodium cromoglycate in inhibiting the late asthmatic response.

Adolescent↗
PubMed1980

Estimation of in vivo digestibility with the laying hen by an in vitro method using the intestinal fluid of the pig.

1. Dry matter and crude protein (nitrogen x 6.25) digestibility of four poultry diets determined by an in vitro method using the intestinal fluid of pigs was significantly correlated with corresponding in vivo digestibility values obtained with hens. 2. The intestinal fluid could be lyophilized and stored for at least 35 d without losing its activity on digestion.

Animal Nutritional Physiological Phenomena↗
PubMed1977

Uptake of 2'-amino-2'-deoxyguanosine by Escherichia coli and its competition by guanosine.

The antibacterial activity of a new nucleoside antibiotic, 2'-amino-2'-deoxyguanosine (2AG), is reversed by guanosine and other purine nucleosides. 2AG is apparently taken up by E. coli by a mechanism different from that of guanosine; guanosine inhibits this uptake non-competitively. Insensitive E. coli strains and the resistant mutant obtained from the sensitive strain also took up 2AG.

Binding, Competitive↗
PubMed1977

Mechanism of growth inhibition by 2'-amino-2'-deoxyguanosine in Escherichia coli.

The mechanism of inhibition of Escherichia coli by the new nucleoside antibiotic, 2'-amino-2'-deoxyguanosine (2AG), is described. Upon the addition of 2AG, the syntheses of macromolecules continued for 15 minutes. After this lag time, protein synthesis sharply decreased, Rna synthesis slightly decreased, but DNA synthesis was not affected. Tritiated 2AG was readily incorporated into the acid-soluble fraction of cells in the form of the mono-, di- and triphosphates. In the acid-soluble fraction, radioactivity was found only in the RNA fraction. The major part of the radioactivity was found to be guanylate; only 25% existed as the nucleotide of 2AG. In resistant strains of E. coli, there was a lower degree of phosphorylating activity and less incorporation of 2AG into RNA per unit of cell mass increase. These results suggest that 2AG inhibits growth by its incorporation into RNA and the subsequent distrubance of RNA function causing a block in protein synthesis.

Bacterial Proteins↗
PubMed1975

Fermentative accumulation of guanosine polyphosphates by Brevibacterium ammoniagenes.

Guanosine-3'-diphosphate-5'-monophosphate (3.35 mg/ml), guanosine-3'-diphosphate-5'-diphosphate (MSI) (5.21 mg/ml), and guanosine-3'-diphosphate-5'-triphosphate (MSII) (0.82 mg/ml), in addition to guanosine 5'-monophosphate, guanosine 5'-diphosphate, and guanosine 5'-triphosphate, were accumulated by microbial conversion of 5'-xanthylic acid with a mutant of Brevibacterium ammoniagenes.

Brevibacterium↗
PubMed1970

Production of nucleic acid-related substances by fermentation processes. 33. Accumulation of inosine by a mutant of Brevibacterium ammoniagenes.

Inosine-producing cultures were found among mutants resistant to 6-mercaptoguanine (6MG) derived from a 5'-inosinic acid (IMP)-producing strain, KY 13102, of Brevibacterium ammoniagenes. Inosine-producing ability was very frequent among the mutants resistant to a low concentration (10 to 50 mug/ml) of 6MG. The accumulation of inosine by strain KY 13714 was stimulated by a low concentration of adenine (25 mg/liter) but was depressed by high levels of adenine. The accumulation by strain KY 13714 was not inhibited by manganese ion but instead was stimulated by its excess, in contrast to IMP accumulation by KY 13102. Addition of hypoxanthine at an early stage of cultivation accelerated inosine accumulation. Furthermore, on addition of hypoxanthine and of a surface-activating agent after 48 hr of cultivation, the simultaneous accumulation of IMP and inosine was observed. A 9.3-mg amount of inosine per ml accumulated after 4 days of cultivation at 30 C. The inosine-producing mutant did not differ from the IMP-producing strain either in 5' purine nucleotide degradation or in IMP formation from hypoxanthine. However, it was found to be completely devoid of purine nucleoside-degrading activity. The conversion of IMP accumulation to inosine can be explained by the lack of nucleosidedegrading activity. The relationship between deficiency of nucleoside-degrading activity and resistance to low levels of 6MG is discussed, and a new mechanism for 6MG resistance is presented.

Adenine↗
PubMed1969

Production of nucleic acid-related substances by fermentative processes. 28. Accumulation of 5' inosinic acid by a manganese-insensitive mutant of Brevibacterium ammoniagenes.

A manganese-insensitive mutant, KY 13105, of Brevibacterium ammoniagenes which accumulates considerable amounts of 5' inosinic acid (IMP) in the presence of 100 to 1,000 mug of Mn(2+) per liter was obtained from an IMP-producing mutant of a manganese-sensitive strain, KY 13102. The effects of Mn(2+) at 0 to 30 mug/liter on IMP accumulation by KY 13105 were similar to those by KY 13102. However, the accumulation of IMP by KY 13105 was not affected by 100 to 1,000 mug of Mn(2+) per liter, showing a clear difference from KY 13102. The accumulation of IMP by KY 13105 was always accompanied by cellular morphological changes irrespective of Mn(2+) concentration. In the presence of Mn(2+), factors which affect IMP accumulation by KY 13105 were examined. Most of the nutrients tested stimulated IMP accumulation at a relatively low concentration (2 g/liter). Iron, calcium, and zinc were found to be essential for IMP accumulation and were independent of Mn(2+). Biotin regulated the growth but not the accumulation of IMP. Under limited or surplus amounts of Mn(2+), the dynamics of IMP fermentation were followed. Under both conditions, the fermentations proceeded in a similar way. The morphological changes were found to be closely related to IMP accumulation.

Adenine↗
PubMed1968

Production of nucleic acid-related substances by fermentative processes. XIX. Accumulation of 5'-inosinic acid by a mutant of Brevibacterium ammoniagenes.

The accumulation of 5'-inosinic acid (IMP) by a mutant, KY 13102, induced from Brevibacterium ammoniagenes ATCC 6872 by ultraviolet light irradiation, was examined. Although growth was stimulated by adenine or adenosine, the microorganism showed fair growth in the medium containing amino acids but no adenine. Among six kinds of natural nutrients tested, meat extract and Casamino Acids were suitable for the accumulation of IMP. Manganese ion strongly affected growth, the accumulation of IMP and hypoxanthine, and cell morphology. Among amino acids tested, L-methionine, L-proline, and L-valine stimulated IMP accumulation. In the medium containing 1.0 g of L-proline per liter, 12.8 mg of IMP per ml was accumulated. The mechanism of IMP accumulation by the mutant is discussed.

Adenine↗
PubMedDate not supplied

Comparison of stepwise and simultaneous estimations of population pharmacokinetics and pharmacodynamics of TS-943.

The prediction performances of population pharmacokinetic-pharmacodynamic analysis of the two methods (a stepwise and a simultaneous estimations) were evaluated with respect to their accuracies and precisions. A study was designed to investigate the safety and efficacy of TS-943 by a 4 hours constant infusion in 36 healthy male subjects. Population analysis was performed using pharmacokinetic and pharmacodynamic models with NONMEM. The mean of the prediction error (MPE) and the root mean squared error (RMSE) served as a measure of accuracy and precision. In addition, a bootstrap validation was also performed. The results indicate that those population pharmacokinetic-pharmacodynamic parameters for the two methods were comparable. The results of simultaneous estimations are similar to those obtained using a stepwise estimation. The mean parameter estimates obtained with the additional 200 bootstrap replicates of data were within 15% of those obtained with the final model in both methods. The present results demonstrated that the accuracy of pharmacodynamic evaluations using a stepwise end a simultaneous estimations was comparable.

Adult↗
PubMedDate not supplied

Ultrastructural fragility and type IV collagen abnormality of the anterior lens capsules in a patient with Alport syndrome.

PURPOSE: To investigate ultrastructural and immunohistological abnormalities of the lens capsules in a patient with Alport syndrome. METHODS: Two anterior lens capsules were obtained at phacoemulsification from a 43-year-old female patient with bilateral lenticonus who was affected by Alport syndrome. The right capsule was examined by transmission electron microscopy and the left capsule was stained with two monoclonal antibodies against the triple-helical domains of type IV collagen alpha2 and alpha5 chains. RESULTS: Numerous vertical dehiscences with many disrupted interdigitations were observed in the right anterior lens capsule. Decreased reactivity of monoclonal antibodies against type IV collagen alpha5 chain and normal reactivity against the alpha2 chain were shown in the left anterior lens capsule. CONCLUSION: The ultrastructural fragility of the anterior lens capsules in this patient with Alport syndrome appears to be associated with the abnormality of the type IV collagen molecules including the alpha5 chain.

Adult↗
PubMedDate not supplied

Development of anti-idiotype monoclonal antibodies for Sialyl Le(a) antigen.

Anti-idiotype monoclonal antibodies (MoAbs) were developed for a carbohydrate antigen, Sialyl Le(a), by immunizing mice with an anti-Sialyl Le(a) MoAb, KM231 (mouse IgG1). The anti-idiotype MoAbs inhibited the binding of KM231 to Sialyl Le(a)-positive mucin protein, but did not affect the binding of another MoAb (mouse IgG1) which recognized a peptide epitope on the same mucin protein. The selected four anti-idiotype MoAbs bound to all of the five anti-Sialyl Le(a) MoAbs examined, but not to other MoAbs developed against Sialyl Le(a)-related carbohydrate antigens such as Le(a), Le(x), and Sialyl Le(x) blood type A, B, H antigens. Immunization of rats with one of the anti-idiotype MoAbs, of which the reactivity was remarkably inhibited by Sialyl Le(a) oligosaccharide, resulted in the induction of antibody (Ab3) to purified Sialyl Le(a) glycolipid. Taken together, one of the anti-idiotype MoAbs developed in this study was the first Ab2 beta-type anti-idiotype MoAb which carried the internal image of Sialyl Le(a) antigen. The positive reaction of tumor cells expressing Sialyl Le(a) antigen with the Ab3 gave rise to the possibility that the anti-idiotype MoAb would become an effective tool for active immunotherapy in patients with Sialyl Le(a)-positive tumor.

Animals↗