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M Otsuki

Publications and source records attributed to M Otsuki.

At least 19 recordsLinked to original sources
PubMed1992

In vitro and in vivo activities of DQ-2556 and its mode of action.

DQ-2556 is a recently developed cephalosporin with a broad spectrum of antibacterial activity against both gram-positive and gram-negative bacteria. Its in vitro activity was roughly comparable to those of cefuzonam and cefpirome and greater than those of ceftazidime, cefepime, and cefclidin against gram-positive bacteria. Against gram-negative bacteria, DQ-2556 showed almost the same activity as those shown by cefpirome and cefepime. The activity was largely unaffected by culture medium pH or the addition of human serum. The protective effect of DQ-2556 in experimental gram-positive pathogen and Escherichia coli infections in mice was greater than those of ceftazidime, cefuzonam, cefepime, and cefclidin and was similar to that of cefpirome. Against Pseudomonas aeruginosa and Acinetobacter calcoaceticus infections, DQ-2556 was more active than cefuzonam and had activity similar to or less than those of ceftazidime, cefpirome, cefepime, and cefclidin. When cells of E. coli were exposed to various concentrations of DQ-2556, filamentous cells were observed at concentrations of 0.0008 micrograms/ml and greater, spheroplasts started to form at 0.025 micrograms/ml, and subsequent cell lysis was observed. The affinity of DQ-2556 to PBP 3 of E. coli, which participates in septum formation, as suggested by morphological observation, was two times greater than that of ceftazidime. DQ-2556 also had high affinities for PBPs 1B and 1A of E. coli. These results suggest that DQ-2556 is worthy for subsequent clinical trials.

Animals↗
PubMed1992

In vitro antibacterial activity of Q-35, a new fluoroquinolone.

The in vitro activity of Q-35, an 8-methoxy fluoroquinolone, was compared with those of ofloxacin, ciprofloxacin, tosufloxacin, lomefloxacin, and sparfloxacin. The MICs of Q-35 for 90% of strains tested (MIC90s) of Staphylococcus aureus, methicillin-resistant S. aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, and Streptococcus pyogenes were 0.2, 6.25, 0.2, 0.39, and 0.39 micrograms/ml, respectively. The activity of Q-35 was 4- to 16-fold greater than those of ofloxacin, ciprofloxacin and lomefloxacin but equal to those of tosufloxacin and sparfloxacin against these organisms. For 82 ciprofloxacin-resistant staphylococci (MIC90 = 100 micrograms/ml), Q-35 was the most active of the new quinolones tested (MIC90 = 6.25 micrograms/ml). The MIC90s of Q-35 against Escherichia coli, Enterobacter aerogenes, and Pseudomonas aeruginosa were 0.2, 0.78, and 12.5 micrograms/ml, respectively, and Q-35 was 2- to 16-fold less active than the other quinolones tested. Q-35 showed potent bactericidal activity and inhibited the supercoiling activity of DNA gyrase of S. aureus, E. coli, and P. aeruginosa.

Anti-Infective Agents↗
PubMed1992

In vitro and in vivo antibacterial activities of E1077, a novel parenteral cephalosporin with a broad antibacterial spectrum.

E1077 is a new injectable cephalosporin with a broad spectrum of antibacterial activity against gram-positive and gram-negative bacteria, including staphylococci and Pseudomonas aeruginosa. The in vitro activities of E1077 against clinical isolates of methicillin-susceptible Staphylococcus aureus (MIC of E1077 for 90% of the strains tested [MIC90], 0.78 microgram/ml) and methicillin-resistant S. aureus (MIC90, 50 micrograms/ml) were similar to those of cefpirome and flomoxef. Against Enterococcus faecalis (MIC90, 6.25 micrograms/ml), E1077 was the most active of the drugs tested and four times more active than cefpirome. The MIC90S of E1077 for streptococci, Haemophilus influenzae, and Neisseria gonorrhoeae ranged from 0.05 to 0.78 microgram/ml; E1077 was similar in activity to cefpirome. E1077 inhibited 90% of most species of the family Enterobacteriaceae at concentrations of less than or equal to 1.56 micrograms/ml, with the exception of Serratia marcescens and Proteus vulgaris (12.5 micrograms/ml). The activity of E1077 against P. aeruginosa (MIC90, 6.25 micrograms/ml) was comparable to that of ceftazidime. In vivo activity was evaluated with systemic infections in mice. E1077 showed a protective effect against systemic infections by gram-positive or gram-negative bacteria, as reflected by its in vitro activity. The protective effects of E1077 were higher than those of cefpirome against S. aureus and P. aeruginosa infections and similar to those of cefpirome against other bacterial infections. Morphological studies using differential interference and phase-contrast microscopy showed that low concentrations of E1077 caused swelling of S. aureus and spheroplast and bulge formation in P. aeruginosa. In general, the antibacterial profile of E1077 is similar to that of cefpirome.

Animals↗
PubMed1992

Bactericidal activities of ofloxacin and its optically active isomer (DR-3355) on non-growing cells of Escherichia coli and Pseudomonas aeruginosa.

In this paper the bactericidal activities of ofloxacin and its optically active derivative, DR-3355, against non-growing cells of Escherichia coli and Pseudomonas aeruginosa are described. E. coli and P. aeruginosa were killed rapidly by ofloxacin and DR-3355. After treatment with these quinolones, the resting cells of E. coli and P. aeruginosa became plasmolyzed, with apparent cytoplasmic shrinkage without filamentation. Membrane-bound intracellular vacuoles and disruption of the cell envelope were also observed, resulting in extrusion of the cytoplasmic contents. These results indicate that non-growing cells of E. coli and P. aeruginosa were susceptible to ofloxacin and DR-3355, as were logarithmically growing cells.

Cell Cycle↗
PubMed1992

[The function of red blood cells under open-heart surgery with extracorporeal circulation without donor blood].

In 18 patients scheduled for open-heart surgery with extracorporeal circulation without donor blood, P50, 2, 3-DPG, intracellular sodium and potassium in red blood cells, and erythrocyte deformability were measured for the purpose of investigating the influence of severe hemodilution on oxygen transport and function of red cells. P50 and 2, 3-DPG in red cells showed no significant changes until the end of cardiopulmonary bypass (CPB). At the end of operation, 2, 3-DPG content decreased significantly without a significant change of P50. This is probably due to the rightward shift of oxyhemoglobin dissociation curve as compensation for the hemodilution without donor blood. On the first postoperative day, P50 value and 2,3-DPG content decreased significantly but returned to previous values on the second day. As the result of changes of red cell sodium contents and deformability, erythrocyte morphology recovered soon after the end of CPB, but the membrane function of red cells was restored a few days later. In conclusion, oxygen transport in red cells may be disturbed after open-heart surgery with extracorporeal circulation without donor blood.

Adolescent↗
PubMed1992

In vitro and in vivo antibacterial activities of meropenem, a new carbapenem antibiotic.

The in vitro and in vivo antibacterial activities of meropenem were compared with those of imipenem, ceftazidime, flomoxef, cefuzonam and cefotiam. Meropenem showed a broad antibacterial spectrum against clinical isolates of Gram-positive and Gram-negative bacteria. Against Gram-negative bacteria, with the exception of Acinetobacter calcoaceticus, meropenem exhibited the most potent activity among the drugs tested. It inhibited all 330 strains of Enterobacteriaceae at 0.78 mg/l. Meropenem was sensitive against several cephem-resistant strains of Enterobacteriaceae. Against Pseudomonas aeruginosa, meropenem was four-fold more active than imipenem and eight-fold more active than ceftazidime, with an MIC90 of 0.78 mg/l. The therapeutic effect of meropenem on systemic infection in mice was ten to twenty-fold less than that of imipenem against Staphylococcus aureus, Streptococcus pyogenes and Streptococcus pneumoniae. However, meropenem was as effective as imipenem on infections of Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Acinetobacter calcoaceticus and Pseudomonas aeruginosa. Meropenem was eliminated from mice plasma two-fold faster than imipenem, with a plasma half-life of 7.6 min. From the above results the authors concluded that meropenem is a promising drug for clinical use.

Animals↗
PubMed1991

Effect of ethanol on pancreatic exocrine secretion in rats.

The effect of ethanol on pancreatic exocrine secretion was studied in isolated rat pancreatic acini. Ethanol caused a dose-dependent stimulation of amylase release, and a twofold increase of amylase release was observed with 600 mM ethanol. Ethanol inhibited cholecystokinin octapeptide (CCK-8)- and carbamylcholine-stimulated amylase release and similarly inhibited binding of [125I]CCK-8 and [N-methyl-3H]scopolamine to isolated rat pancreatic acini in a dose-dependent manner. The inhibitory effect of ethanol was fully reversible with respect to CCK-8-induced amylase release. On the other hand, ethanol potentiated secretin- and vasoactive intestinal peptide (VIP)-stimulated amylase release. Ethanol induced a small but significant increase in Ca2+ efflux, whereas CCK-8 induced an immediate and large increase, but ethanol significantly inhibited CCK-8-stimulated Ca2+ efflux. The present study clearly demonstrates the dual effects of ethanol on pancreatic exocrine function: stimulation and inhibition. We suggest that mobilization of intracellular Ca2+ may be involved in the mechanism of ethanol's action on isolated rat pancreatic acini.

Amylases↗
PubMed1991

In vitro antibacterial activity of a new quinolone, NM394.

NM394 is a new 6-fluoroquinolone antibacterial agent with a tricyclic structure which has a bridge that connects the N-1 and C-2 positions of the quinolone. The antibacterial activity of NM394 against clinical isolates of staphylococci, streptococci, enterococci, members of the family Enterobacteriaceae, and Pseudomonas aeruginosa was equal to or one-half that of ciprofloxacin. NM394 was as active as ofloxacin against gram-positive bacteria and was two to eight times more active against gram-negative bacteria, including P. aeruginosa. NM394 was two to eight times more active than enoxacin against gram-positive and gram-negative bacteria. The MICs of NM394 against Escherichia coli and P. aeruginosa at pH 5.5 were reduced 4 to 16 times compared with those at pH 7.0. Ciprofloxacin, ofloxacin, and enoxacin were 2 to 32 times less active against these two bacteria and Staphylococcus aureus at an acidic pH than they were at pH 7.0. In the presence of 5 mM Mg2+, the MICs of all of these drugs increased 2 to 32 times, but they were only slightly affected by 5 mM Ca2+, type of medium, serum, or size of inoculum. NM394 showed potent bactericidal activity and inhibited the supercoiling activity of E. coli DNA gyrase. The in vitro antibacterial profile of NM394 is similar to that of other 6-fluoroquinolones.

Anti-Infective Agents↗
PubMed1991

In vivo evaluation of NM441, a new thiazeto-quinoline derivative.

NM441 is a lipophilic prodrug of a new thiazeto-quinoline carboxylic acid derivative NM394, and when it is administered orally it is readily absorbed and hydrolyzed to its parent compound. After oral administration of NM441 at a dose of 20 mg/kg to dogs, the peak concentration of NM394 in plasma was 2.39 micrograms/ml, whereas it was 0.63 micrograms/ml for NM394 administered alone. The in vivo activity of NM441 was compared with those of ciprofloxacin, ofloxacin, and enoxacin in mouse protection studies. NM441 was as effective as ofloxacin and was twice as effective as ciprofloxacin against systemic infection with Staphylococcus aureus. Against infections with streptococci, NM441 was two to three times as effective as ofloxacin and five times as effective as ciprofloxacin. Against infection with Escherichia coli, NM441 was as effective as ciprofloxacin and ofloxacin, but against infections with Klebsiella pneumoniae, Serratia marcescens, and Pseudomonas aeruginosa, NM441 was two to four times as effective as ciprofloxacin and ofloxacin. NM441 was three to seven times as effective as enoxacin in systemic infections. Against urinary tract infections with E. coli, NM441 reduced the number of bacterial CFU per gram of kidney by 1 to 2 log10 more and, with P. aeruginosa, by 1 to 6 log10 more than did ciprofloxacin and ofloxacin. Against respiratory tract infections with K. pneumoniae, NM441 was as effective as ofloxacin and was twice as effective as ciprofloxacin.

Administration, Oral↗
PubMed1990

Beneficial effects of the synthetic trypsin inhibitor camostate in cerulein-induced acute pancreatitis in rats.

The therapeutic effect and the mechanism of action of the synthetic trypsin inhibitor camostate were studied in a rat model of acute interstitial pancreatitis induced by four subcutaneous injections of 20 micrograms/kg body weight of cerulein at hourly intervals. Rats with acute pancreatitis were given either 100 mg/kg body weight camostate or volume- and pH-adjusted water via an orogastric tube 30 min after the last cerulein injection. The elevation of serum amylase activity was significantly reduced by camostate treatment and the peak value was seen 1 hr earlier than that observed in the rats that did not receive camostate. Camostate also inhibited the reduction in pancreatic content of lipase and amylase seen during experimental pancreatitis. These effects were accompanied by alleviation of the histologic signs of acute pancreatitis such as cellular infiltration and acinar cell vacuolization. After oral administration, camostate and its metabolite were absorbed from the intestine and were detectable in plasma for more than 6 hr in concentrations high enough to have antiprotease activity. In addition, camostate in the duodenum was able to increase pancreatic juice flow and protein output and to stimulate endogenous secretin release. These results suggest that oral administration of camostate reduces the severity of cerulein-induced acute pancreatitis by releasing endogenous secretin and by its antiprotease activity.

Acute Disease↗
PubMed1990

Enzyme immunoassay for human pancreatic amylase.

An enzyme immunoassay (EIA) for human pancreatic amylase has been developed for the detection of human serum amylase content. Our monoclonal antibody is highly specific for human pancreatic amylase; it cross reacted negligibly with the salivary isoenzyme. We developed a solid phase enzyme immunoassay for determination of pancreatic amylase in human serum with this antibody. The assay required 20 microL of serum and the standard curve was linear to at least 1000 ng/mL of pancreatic amylase. Inter- and intra-assay CVs were less than 10%. The results obtained by the EIA correlated well with those determined by the conventional electrophoretic method. In normal subjects, the mean concentration of serum pancreatic amylase determined by the EIA was found to be 92.3 +/- 26.1 ng/mL (mean +/- SD). The EIA we describe is useful for directly determining pancreatic amylase in human serum. Specifically distinguishing pancreatic from salivary amylase may have considerable clinical value.

Amylases↗
PubMed1990

Effects of L-364,718 on pancreatic exocrine and endocrine secretion in the rat.

We examined the inhibitory effect of L-364,718, a nonpeptide cholecystokinin (CCK) antagonist, on CCK stimulation of pancreatic exocrine and endocrine secretion in both the isolated pancreatic acini and the isolated perfused pancreata of rats. In the isolated acini, L-364,718 inhibited CCK octapeptide (CCK-8)-stimulated amylase release and binding of 125I-CCK-8 in a dose-dependent manner without appreciable effects on the basal amylase secretion. L-364,718 also inhibited amylase release in response to caerulein and gastrin I, but had no effect on amylase release stimulated by other secretagogues or by agents bypassing receptors. Similarly, binding of N-methylscopolamine to pancreatic acini was not inhibited by L-364,718. In the isolated perfused pancreata, L-364,718 inhibited CCK-8-stimulated pancreatic exocrine secretion and insulin release. The inhibitory effects of L-364,718 were more potent for insulin release than for exocrine secretion and persisted even after the removal of L-364,718 infusion. These results clearly demonstrate that L-364,718 is a specific, potent, and prolonged antagonist of CCK's stimulatory actions on pancreatic acinar and B cells.

Amylases↗
PubMed1990

Action of a new cholinergic agonist, aclatonium napadisilate, on isolated rat pancreatic acini.

The effect of aclatonium napadisilate, a newly synthesized choline ester, on pancreatic exocrine function was compared with that of the muscarinic agonist carbamylcholine in isolated rat pancreatic acini. Both compounds increased amylase release and 45Ca2+ efflux in a dose-dependent fashion, and similarly decreased the binding of [N-methyl-3H]scopolamine to isolated rat pancreatic acini. While aclatonium napadisilate was 20-30 times less potent than carbamylcholine in stimulations of amylase release and 45Ca2+ efflux, the potency of aclatonium napadisilate in inhibiting [N-methyl-3H]scopolamine binding was nearly the same as that of carbamylcholine. These results indicate that aclatonium napadisilate stimulates pancreatic exocrine secretion via muscarinic receptors and Ca2+ mobilization, and its intrinsic activity is less than carbamylcholine in the isolated rat pancreatic acini. Since aclatonium napadisilate is known to increase motility and peristalsis of the gastrointestinal tract, stimulatory effects of aclatonium napadisilate, shown in the present study, on digestive enzyme secretion from the pancreas may provide additional benefit of aclatonium napadisilate in the treatment of various gastrointestinal disorders.

Acetylcholine↗