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Biomedical subjects

A Tsuji

Publications and source records attributed to A Tsuji.

At least 361 records · Page 20Linked to original sources
PubMed1989

Serum protein binding of lomefloxacin, a new antimicrobial agent, and its related quinolones.

The serum protein binding of lomefloxacin (LFLX), a new quinolone (pyridonecarboxylic acid), and its related analogues was studied by an ultrafiltration technique. The extent of binding of quinolones was independent of the concentration of quinolones below 100 micrograms/mL in rat serum; but, above this concentration, the binding decreased with increased drug concentration in the case of nalidixic acid and analogue 3. The extent of binding in rat serum differed widely among the quinolones examined [i.e., from 15% (norfloxacin) to 84% (nalidixic acid) at concentrations of 0.4-10.0 micrograms/mL]. Lomefloxacin was bound to serum proteins to the extent of 28.1, 20.1, and 20.6% in the sera of rats, dogs, and humans, respectively. The binding of nalidixic acid with rat serum albumin, which was very similar to that in rat serum, was concentration dependent. Some quinolone derivatives with a piperazinyl group or a relatively large-sized substituent at the 7-position exhibited a percentage unbound of approximately 70-80%, while some derivatives with small-sized substituents gave a low percentage unbound of 20-30%. This suggests that there is a steric effect of the substituents at the 7-position of quinolones on their binding characteristics with serum proteins. The results of the present study indicate that quinolones bind mainly with albumin among serum proteins and that the remarkable difference of the extent of binding of quinolone analogues is related to the size of the substituent at the 7-position of the molecule, possibly due to its steric effect.

Animals↗
PubMed1989

Age-related change in tissue-to-plasma partition coefficient of cefazolin for noneliminating organs in the rat.

Age-related changes in tissue distribution characteristics of cefazolin, a cephalosporin antibiotic, were examined for noneliminating organs of rats. The in vivo tissue-to-plasma partition coefficients (Kp,vivo) varied markedly among different ages and organs. In particular, muscle and skin acted as reservoirs for cefazolin distribution. There were also marked differences in interstitial fluid space (IS), determined using [14C]inulin, among different ages and organs. For muscle and bone, the magnitude of the age-related changes in Kp,vivo of cefazolin and IS was in the order of 1-week-old greater than 7-week-old = 100-week-old greater than 50-week-old rats. This is well correlated with the age-related changes in the volume of distribution at the steady state of cefazolin per body weight (Vdss/BW) and the extracellular fluid volume per body weight (Vecw/BW) determined previously using [14C]inulin. The predicted Kp value (Kp,pred) was estimated by incorporating the serum protein binding parameters of cefazolin, the IS values, and an interstitial-to-plasma albumin concentration ratio (AR) into equations derived from an extracellular fluid model. The Kp,pred values exhibited a fairly good correspondence with the Kp,vivo values determined for various organs, except gut, in rats of all four ages. These results suggest that the determinant of the age-related change in Vdss/BW is the difference in the IS value of muscle and bone, while the age-related change in serum protein binding plays only a modest role.

Adolescent↗
PubMed1989

Prediction of the distribution volumes of cefazolin and tobramycin in obese children based on physiological pharmacokinetic concepts.

So as to estimate the appropriate dose of antibacterial drugs in obese children, prediction of the volume of distribution in these children was attempted based on physiological pharmacokinetic concepts which had been constructed from results in normal-weight children. Serum concentration-time data after intravenous drip infusions of tobramycin and cefazolin were analyzed using noncompartmental analysis of obese children in whom the degree of obesity ranged from 30 to 80%. Volume of distribution at steady state (Vss) per total body weight of tobramycin was significantly less than that for normal-weight children (P less than 0.05), whereas the value of cefazolin was almost equal to that for normal-weight children. The equation to express the difference of Vss between cefazolin and tobramycin obtained in normal-weight children failed in obese children, suggesting that there is a large decrease in the extracellular space in obese children exceeding the interindividual variations in normal-weight children. The Vss value (liter) for tobramycin was predicted by using the equation 0.261 . (ideal body weight (kg) + 0.4 . [total body weight (kg) - ideal body weight (kg)]). The Vss value of cefazolin was predicted to be 0.3 . (predicted Vss of tobramycin) + 0.052 . total body weight (kg). A good correlation between the predicted and the observed Vss values was obtained.

Blood Proteins↗
PubMed1989

Purification and characterization of beta-mannosidase from human placenta.

Lysosomal beta-mannosidase was purified almost 10,000-fold from human placenta. The final preparation showed several protein bands on polyacrylamide gel electrophoresis. Its molecular mass was estimated to be 110 kDa, the optimal pH was 4.5, the Km was 0.56 mM, and the isoelectric point was 4.7. The enzyme was found to bind completely to Con A-Sepharose, and the pI was not changed after neuraminidase treatment. These results indicate that the purified enzyme represents a lysosomal form which contains high mannose type oligosaccharide chains and only a few sialic acids, if any.

Ammonium Sulfate↗
PubMed1989

In vitro and in vivo activities of QA-241, a new tricyclic quinolone derivative.

The in vitro susceptibilities of 1,310 clinical isolates to QA-241, a novel tricyclic quinolone, were evaluated in comparison with susceptibilities to norfloxacin, ofloxacin, enoxacin, and ciprofloxacin. The MICs of QA-241 for 90% of staphylococci, Enterococcus faecalis isolates, and streptococcal species ranged from 1.56 to 6.25 micrograms/ml, and the activity of QA-241 was similar to those of norfloxacin and enoxacin but two to four times less potent than those of ofloxacin and ciprofloxacin. At the concentration of less than or equal to 1.56 micrograms/ml, QA-241 inhibited 90% of Haemophilus influenzae, Bordetella pertussis, Neisseria gonorrhoeae, and gram-negative enteric bacteria except for Serratia marcescens and Citrobacter freundii. QA-241 was moderately active (MIC for 90% of strains tested, 6.25 to 12.5 micrograms/ml) against S. marcescens, Pseudomonas aeruginosa, Xanthomonas maltophilia, and Bacteroides fragilis. The antibacterial activity of QA-241 was roughly comparable to that of enoxacin but two to four times less potent than that of ofloxacin. In systemic infections in mice with gram-positive cocci and gram-negative rods, the efficacy of QA-241 was generally greater than that of norfloxacin and similar to those of ofloxacin and ciprofloxacin. In urinary tract infections in mice with Escherichia coli or Pseudomonas aeruginosa, QA-241 was as active as ofloxacin and more active than norfloxacin but less active than ciprofloxacin. In pulmonary infections in mice with Klebsiella pneumoniae, the effectiveness of QA-241 was similar to that of ofloxacin.

4-Quinolones↗
PubMed1989

Highly sensitive biotin-labelled hybridization probe.

A simple chemical method for introducing biotin into nucleic acids has been developed for the synthesis of nonisotopic hybridization probes. The method is based on the reaction of biotin hydrazide with amino residues of nucleic acids by using glutaraldehyde as a bifunctional coupling reagent. Biotin-labelled deoxyribonucleic acid (DNA) was detected by the use of alkaline phosphatase-labelled avidin, and alkaline phosphatase activity was measured by colorimetric and chemiluminescence methods. The chemiluminescence method using the nicotinamide adenine dinucleotide phosphate (NADP)/alcohol/alcohol dehydrogenase/microperoxidase/isoluminol system gave the highest sensitivity. A few picograms of lambda-phage DNA coated on a microtiter plate well could be detected by this method.

Biotin↗
PubMed1989

[The changes in plasma histamine levels after a sulpyrin inhalation test in asthmatic patients].

A sulpyrin inhalation test was given to 13 patients with aspirin-induced asthma (AIA) and 8 patients with non-aspirin-induced asthma (non-AIA) to observe the changes in plasma histamine levels before and after challenges. The respiratory function (FEV1.0) was measured before and after sulpyrin inhalation. A decrease of more than 20% the initial value (basal value) was defined as a positive response. Plasma histamine was determined by high-performance liquid chromatography (HPLC). In 11 patients with AIA, a positive response was observed (SIT positive), with a fall of FEV1.0 to 63.70 +/- 4.87% of the basal value. In 2 patients with AIA and 8 patients with non-AIA, no positive response was observed (SIT negative). In patients with SIT positive, plasma histamine levels increased significantly from 0.61 +/- 0.06 ng/ml before challenges to 1.34 +/- 0.22 ng/ml after challenges (p less than 0.01). No significant changes of plasma histamine occurred in the SIT negative patients. These results suggest that mast cells play some role in the mechanism of the development of aspirin-induced asthma.

Adult↗
PubMed1989

Absorptive-mediated endocytosis of a dynorphin-like analgesic peptide, E-2078 into the blood-brain barrier.

The binding and internalization of a novel analog of dynorphin-like analgesic basic peptide, [125I]E-2078 (CH3-[125I] Tyr-Gly-Gly-Phe-Leu-Arg-CH3Arg-D-Leu-NHC2H5), by isolated bovine brain capillaries were investigated. High-performance liquid chromatographic analysis showed that no significant metabolism of [125I] E-2078 occurred during incubation with brain capillaries for 30 min at 37 degrees C. The binding of [125I]E-2078 to brain capillaries increased with time and the steady-state cell-to-medium concentration ratio was 58.5 +/- 2.6 microliters/mg of protein. Approximately one-fourth of the [125I]E-2078 binding was resistant to acid wash, and showed significant dependence on temperature and medium osmolarity. The acid sensitive binding of [125I]E-2078, which presumably represents surface binding, was saturable and the Scatchard plot gave a maximal binding capacity Bmax = 147 +/- 29 pmol/mg of protein, and a half-saturation constant (KD) = 4.62 +/- 0.59 microM. Pretreatment of brain capillaries with phenylarsine oxide, an endocytosis inhibitor, completely suppressed the acid resistant binding of [125I]E-2078, but did not influence the surface binding of [125I]E-2078. The acid resistant binding of [125I] E-2078 was inhibited by poly-L-lysine and protamine, but not inhibited by insulin, transferrin, dynorphin (1-8), beta-neoendorphin, naloxone or poly-L-glutamate. Moreover, in vivo brain extraction of [125I]E-2078 in rats was 368 +/- 55% higher than that of [3H] sucrose and was significantly inhibited by 1 mM of unlabeled E-2078. These results demonstrate that E-2078 is internalized by brain capillaries via absorptive-mediated endocytosis, which is a polycation-sensitive pathway.

Animals↗
PubMed1989

[A modified Shirodkar procedure--double cervical cerclage with an auxiliary loop].

Cervical cerclage high enough at the level of the internal ostium is effective in treating incompetent cervix. And double cerclage at a distance can close the cervix at a higher level even in the case of marked dilation with "bulging membranes". But the higher the cerclage, the more difficult it is to remove the suture at term. To solve this problem, we have designed a modified Shirodkar procedure, "The double cervical cerclage with an auxiliary loop". We have used this new method in 31 cases. In every case the closure was at a high level and the suture was able to be removed very easily at term without any complication.

Cervix Uteri↗
PubMed1989

[Anesthetic management in surgery of a descending aortic aneurysm in an eighteen-month-old boy].

Aortic aneurysm occurs rarely in childhood. Most aneurysms in children are associated with conditions such as Marfan's syndrome, coarctation of the aorta, Ehlers-Danlos syndrome and neurofibromatosis. We report a case of descending thoracic-abdominal aortic aneurysm in an eighteen month old boy with a mask-like face, ocular hypertelorism, blepharoptosis, a high arched palate and low set ears. He was scheduled for a bypass graft of the descending thoracic and abdominal aorta under partial cardiopulmonary bypass. High dose morphine anesthesia (2mg/kg) was employed and halothane was used to control the blood pressure. To our knowledge, anesthetic management of such an infant had not been reported. Therefore, we anesthetized this child according to anesthetic managements for adult cases considering carefully the boy's multiple anomalies. Anesthetic managements for the surgery of aortic aneurysms in childhood are discussed.

Anesthesia↗
PubMed1989

[Evaluation of hepatic function by hepatobiliary scintigraphy using factor analysis].

Factor analysis of hepatobiliary scintigraphy using 99mTc-N-pyridoxyl-5-methyltryptophan (99mTc-PMT) was performed, and functional factor of liver parenchyma (FA-hepatogram) was obtained. Two parameters (peak time, T 1/2) were calculated from this hepatogram. A good correlation was obtained between these parameters and ICG-R15; furthermore, these parameters were prolonged in patients with normal volunteers, chronic hepatitis, compensated and decompensated liver cirrhosis in this order. Conventional hepatogram by ROI method (ROI-hepatogram) was not suitable for the evaluation of global liver function in condition such as a large intrahepatic mass, intrahepatic gall bladder, dilatation of biliary tree, and severe liver cirrhosis. But, even in such cases, FA-hepatogram was useful for the evaluation of global liver function.

Biliary Tract↗
PubMed1989

Radiographic evaluation of blunt renal trauma.

Radiographic evaluation was performed on 18 patients with blunt renal trauma. Of 18 patients 11 had minor injury. Four of 11 patients with minor injury had a normal intravenous pyelogram (IVP), and other 7 were confirmed to have minor renal injury by computed tomographic (CT) scan. Seven patients had major injury. Six patients were diagnosed by both IVP and CT, and five by angiography. CT scan was reliable in major injury and had the high staging accuracy. Angiography was useful in specific patients. Therefore, we conclude that IVP or CT scan should be performed as the initial evaluation, and CT scan or angiography might be used as the second examination in selected patients.

Adolescent↗
PubMed1989

[New method for preventing spinal headache (prophylactic blood patch method)].

After spinal anesthesia, early ambulation frequently caused spinal headache. If the patient was discharged on the day of the operation, spinal headache occurred very frequently. With epidural anesthesia, if the dura was erroneously punctured with the needle, headache often occurred. In order to prevent spinal headache, we tried the Blood Patch Method during operation (Prophylactic Blood Patch Method). Epidural catheterization and spinal tap were simultaneously performed. The epidural catheter was threaded 3 cm cephalad in the epidural space. Five ml Venous blood of the patient was injected through the epidural catheter (Blood Patch Method). Epidural puncture was performed one spinal segment cephalad (A Method) or one spinal segment cauded (B Method) from the site of spinal puncture. The prophylactic Blood Patch Method was very effective in preventing spinal headache after the dural puncture. Especially B Method, in which blood was injected near the dural pore, was much more effective than A Method.

Anesthesia, Obstetrical↗
PubMed1988

Cloning, sequencing, and expression of cDNA for human beta-galactosidase.

We cloned and sequenced the full-length cDNA for human placental beta-galactosidase. The 2379-nucleotide sequence contains 2031 nucleotides which encode a protein of 677 amino acids. The amino acid sequence includes a putative signal sequence of 23 amino acids and 7 potential asparagine-linked glycosylation sites. The cDNA in the expression vector pSVL was used to transfect COS cells. Expression of the cDNA in transfected COS cells produced immunoprecipitable proteins and led to an increase in beta-galactosidase activity.

Amino Acid Sequence↗
PubMed1988

Regulation of band 3 mobilities in erythrocyte ghost membranes by protein association and cytoskeletal meshwork.

Rotational diffusion of erythrocyte anion channel protein band 3 was measured in ghost membranes by observing time-resolved phosphorescence anisotropy decays of eosinyl-5-maleimide covalently attached to the protein. Experiments were carried out under conditions similar to those employed by Tsuji and Ohnishi (1986) for translational diffusion measurement of band 3 [(1986) Biochemistry 25, 6133-6139] to allow direct comparison of rotational and translational diffusion of band 3. Detailed analysis of diffusive properties of band 3 in ghost membranes was made on the basis of these rotational and translational diffusion data. Rotational diffusion measurements indicated that there are at least three populations of band 3 molecules with high, low, and no rotational mobilities in the time scale of 10(-4)-10(-2) s. These populations are in equilibrium, and the fractional ratios are strongly temperature dependent. At 26 degrees C, 44% of band 3 molecules are mobile (16% have an average rotational correlation time of 0.19 ms, and 28% have an average correlation time of 2.4 ms), and 56% are immobile. These results correlate well with translational diffusion data which indicated 40% mobile and 60% immobile fractions of band 3. The rotational diffusion data together with the translational diffusion data by Tsuji and Ohnishi (1986) and Golan and Veatch [(1980) Proc. Natl. Acad. Sci. U.S.A. 77, 2537-2541] suggest that immobilization of band 3 is largely caused by binding of band 3 oligomers to ankyrin, which abolishes both rotational and translational diffusion of band 3.(ABSTRACT TRUNCATED AT 250 WORDS)

Affinity Labels↗