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Biomedical subjects

Y Ueda

Publications and source records attributed to Y Ueda.

At least 775 records · Page 43Linked to original sources

[Studies on the sub-MIC of beta-lactam antibiotics--bactericidal activity in compromised host's serum].

Bactericidal activity in compromised host's serum i.e. patients with cancer, the elderly, diabetes, was stronger than that in normal serum against Proteus mirabilis (P. mirabilis) but was weaker against Klebsiella pneumoniae (K. pneumoniae). Against Escherichia coli (E. coli), bactericidal activity on serum of patients with cancer was weaker in the following order, that in elderly serum, that in diabetic serum. Against Proteus vulgaris (P. vulgaris), bactericidal activity in elderly serum was similar to that in normal serum but was stronger than that in serum of patients with cancer. Against Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus), bactericidal activity in elderly serum and diabetic serum was similar to that in normal serum but was weaker than that in serum of patients with cancer. Piperacillin showed bactericidal activity in nutrient broth, normal serum and compromised host's serum at a concentration of 1/4 MIC against E. coli, P. mirabilis and P. aeruginosa. Aspoxicillin showed bactericidal activity in nutrient broth, and bactericidal or bacteriostatic activity in normal serum and serum of patients with cancer against E. coli and P. aeruginosa. While cefazolin and cefmetazole slightly inhibited the growth of bacteria in nutrient broth, they showed hardly any bactericidal activity in normal serum and compromised host's serum.

Aged↗

[Effects of immunoglobulin preparations on the opsonic activities against various pathogens].

We evaluated the opsonic activities of human intravenous immunoglobulin (IVIG) preparations against pathogenic organisms by measuring the luminol-enhanced chemiluminescence (CL) from human polymorphonuclear leukocytes (PMN) during the phagocytosis of these organisms. Polyethylenglycol-treated IVIG significantly increased the CL of PMN by opsonization against various bacteria and Candida albicans (p less than 0.01). The high CL induced by IVIG with intact Fc-fragment showed no significant differences among lots or preparations made by different treatments. In both PMN-CL in the absence of human serum and whole blood CL at low concentration of serum complement, the CL response was not affected by pepsin-treated IVIG. In the severely burned patients' blood with a very low concentration of serum immunoglobulin, IVIG with intact Fc-fragment significantly increased CL (p less than 0.01). It is suggested that administration of IVIG is useful against infections in these patients. The measurement of whole blood CL in vitro may be useful for evaluating the opsonic activity of IVIG against target pathogens in vivo.

Bacteria↗

Beneficial effects of angiotensin-converting enzyme inhibitor on renal function and glucose homeostasis in diabetics with hypertension.

The antihypertensive efficacy of enalapril and its effects on renal function and glucose homeostasis were investigated in 9 hypertensive patients with non-insulin-dependent diabetes mellitus. Enalapril therapy produced a significant fall in blood pressure (BP) (p less than 0.05) and a significant increase in renal blood flow (p less than 0.05) without a change in glomerular filtration rate. Furthermore, fasting plasma glucose was significantly reduced (p less than 0.01). Similarly, M value, as an index of plasma glucose control in diabetes, was significantly reduced from 19.6 to 10.1 (p less than 0.01). These findings suggested that the angiotensin-converting enzyme inhibitor enalapril was effective in reducing BP and improving renal function, and might improve glucose homeostasis in hypertensive diabetics.

Aged↗

Retention of perfluorochemicals in tumor-bearing rats.

In order to study the elimination rate of perfluorochemical (PFC) emulsion from the blood and the PFC contents in the main organs of the tumor-bearing animals, Wistar strain rats were intramuscularly implanted with Walker 256 carcinosarcoma and 9L glioma cells were innoculated into the femoral muscle of Fischer rats. After 7 d the Wistar rats received an injection of 4 g PEC/kg of a PFC emulsion. The Fischer rats received a similar injection after 11 d. The rats injected with the PFC emulsion were periodically sacrificed for a week. There was no significant difference in PFC contents in the blood and main organs between normal rats and the tumor-bearing rats with either Walker 256 carcinosarcoma or 9L glioma. The PFC contents in Walker tumor were about 10 times as much as those of 9L tumor. The innoculated tumors did not substantially affect the PFC retention in the blood and the accumulation of PFC in main organs after intravenously injected with the PFC emulsion.

Animals↗

Studies on aldose reductase inhibitors from medicinal plant of "sinfito," Potentilla candicans, and further synthesis of their related compounds.

For several years we have screened natural products having aldose reductase (AR) inhibitory activity. 3,3',4-Tri-O-methylellagic acid 4'-sulfate potassium salt (2) was isolated from a Mexican herb "Sinfito" (Potentilla candicans) as a potent AR inhibitory active constituent. 2 was more potent (IC50 = 8.0 x 10(-8)M) than ellagic acid, which is one of the natural inhibitors of AR. So we examined the synthesis of ellagic acid derivatives and found that the sulfate group is one of the important function.

Aldehyde Reductase↗

Developmental changes in the umbilical arteries with observation of the effects of indomethacin in fetal rats.

The caliber of the umbilical arteries was measured in fetal rats on day 14 to 21 of gestation. The fetuses were rapidly frozen in an acetone-dry ice mixture. The caudal half of each whole-body frozen fetus was gradually shaved with a knife from the ventral side to expose the umbilical arteries for measurement of their calibers. Observation reveals that, on day 15 of gestation, the umbilical arteries are asymmetrical in that the right artery is more dilated than the left. It is further seen that the left umbilical artery is closed on day 17 in contrast to the right which is increasingly more dilated toward term. When indomethacin, a synthetic compound having an action similar to that of glucocorticoids, was administered to pregnant rats 3 hr prior to sacrifice on day 21 of gestation, the right fetal umbilical artery was significantly constricted. The reason for this phenomenon is unknown, but is discussed in association with the manner of closure of the ductus arteriosus.

Animals↗

Development of monoclonal antibodies against human gastrointestinal cancer.

We have evaluated approximately 10,000 monoclonal antibodies resulting from 14 hybridization of spleen cells from mice immunized with established cancer cell lines. They were screened by binding assays using cancer cell lines or normal fibroblast cells, followed by immunohistochemical study on tissue sections. Ninety-one monoclonal antibodies were obtained by above binding assays. One of them, named KM10 was further investigated. Isotype of KM10 was IgG1 with kappa-light chain. It was shown that KM10 has strong reactivity with tumors of colon, stomach, papilla Vater, and pancreas, while the limited reactivity displayed with normal tissues. The electron microscopic observation revealed that the antigen recognized by KM10 is expressed on the surface of cancer cells. KM10 could mediate ADCC. These results indicate that KM10 is a good candidate for a probe of diagnosis and therapy of cancer.

Antibodies, Monoclonal↗

Synthesis and cytostatic activity of the antitumor antibiotic chartreusin derivatives.

In order to overcome the rapid biliary excretion of chartreusin, which diminished its activity when administered iv, a series of 3',4'-O-substituted derivatives of chartreusin were synthesized. Exo-type of 3',4'-O-benzylidene-chartreusin was found active both by ip and iv administration. Therefore, this compound was selected for further modification on its 6-phenol to obtain broader spectra and better pharmacokinetic parameters than the original compound. Several 6-O-acyl-3',4'-O-exo-benzylidene-chartreusins had high antitumor activity against some murine tumors both by iv and po administration.

Aminoglycosides↗

[Effect of NIK-242 inj. (20% erythritol) on intracranial pressure in dogs with acute obstructive hydrocephalus].

The effects of NIK-242 inj. (20% erythritol) on intracranial pressure (ICP) and serum osmotic pressure (Osm. P) were investigated in dogs with acute obstructive hydrocephalus, and they were compared with those of 20% mannitol or 10% glycerol in 5% fructose and 0.9% saline. Animals were divided into 5 groups (n = 6 in each group) and treated with either NIK-242 inj. (0.5 g/kg, 1.0 g/kg, 2.0 g/kg), mannitol (1.0 g/kg) or glycerol (0.5 g/kg). These drugs were administrated intravenously for 10 min. NIK-242 inj. rapidly reduced ICP and increased Osm. P. There was correlation between changes of ICP and Osm. P. The regression equation was Y = -6.489 X + 726.206 (n = 104, p less than 0.00001, R = -0.655). The effects were dose-dependent, but there were no significant differences between the effects of NIK-242 inj. 1.0 g/kg infusion and 2.0 g/kg infusion. The most appropriate dose of NIK-242 inj. was 1.0 g/kg, in which group ICP was significantly lower than the initial pressure until 120 minutes after administration (p less than 0.05). The maximum reduction rate of ICP [(initial ICP-minimum ICP)/initial ICP X 100] was 83.6 +/- 10.6% at 22.7 +/- 3.0 min. after administration. It was 61.6 +/- 6.9% at 19.3 +/- 1.6 min. in mannitol group and 77.1 +/- 7.4% at 15.0 +/- 0.8 min. in glycerol group. There was no rebound phenomenon on ICP during 150 min., but there was one in mannitol group and five in glycerol group. NIK-242 inj.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

[Possible mechanisms of the anti-inflammatory action of polyamines].

Carrageenin paw edema of rats was inhibited in a dose-dependent manner by subcutaneous administration of polyamines. The latter had to be administered at least 2 hr before carrageenin challenge to achieve such inhibition. Moreover, inhibition was blocked by the simultaneous injection of actinomycin D. Polyamines also inhibited local bluing reactions to histamine in rats and similarly had to be administered 3 hr previously to achieve inhibition. Polyamines were shown to be glucocorticoid-type anti-inflammatory drugs, and may be glucocorticoids mediators of the synthesis of the postulated vascular permeability inhibitory protein that do not inhibit phospholipase A2 activity. Neutrophil chemotaxis was inhibited by polyamines in a concentration-dependent manner. In contrast to the experience with carrageenin paw edema, simultaneous addition to actinomycin D did not block the inhibitory action of polyamines on neutrophil chemotaxis. These results suggest that polyamines possess at least 2 different anti-inflammatory mechanisms. The first is mediated by the synthesis of an anti-inflammatory protein, and the second consist of direct action on leukocytes.

Animals↗

[Abnormalities in autologous mixed lymphocyte reaction-induced T cell activation cascade in rheumatoid arthritis and their possible correction by methyl-B12].

We have previously shown that when patients with active rheumatoid arthritis (RA) were examined for the ability of their lymphocytes to respond in the autologous mixed lymphocyte reaction (AMLR), profoundly reduced AMLR responses were found in the RA patients. The defects were mainly due to the impaired response of CD8+ and CD4+ Law8- subsets; however, both CD4+Leu8+ and CD4+ + Leu8- cells functioned normally as responding cells. The present study demonstrated that the abnormalities of RA CD8+ T cells in the AMLR were corrected when the AMLR cultures were set up in the presence of methyl-B12. In addition, a main target of the methyl-B12 effect observed was both CD8+Leu8+ and CD8+Leu8- cells. Thus, methyl-B12 may become a potential agent that would be able to control the pathophysiology of RA.

Adult↗