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Biomedical subjects

K Saionji

Publications and source records attributed to K Saionji.

33 records · Page 2Linked to original sources

[G-CSF and G-CSF receptor].

Relationship between leucocytosis and G-CSF blood concentration were examined. Increase in blood concentration of G-CSF of surgical patient and dialysis patient with leucocytosis were noticed. Determination of G-CSF receptor on leucocyte was performed by the flow cytometry using biotinylated G-CSF. Modulation of G-CSF receptor on leucocyte at surgery and dialysis was identified in vivo. Studies of G-CSF blood concentration and modulation of G-CSF receptor are useful in analysis of dynamics of leucocyte and analysis of infectious disease.

Granulocyte Colony-Stimulating Factor↗

Granulocyte colony-stimulating factor down-regulates the surface expression of the human leucocyte adhesion molecule-1 on human neutrophils in vitro and in vivo.

The leucocyte adhesion molecule-1 (LAM-1) is the human homologue of the murine peripheral lymph node homing receptor, MEL-14, and might play a crucial role in neutrophil localization at inflammatory sites. We have reported previously that recombinant human granulocyte colony-stimulating factor (rhG-CSF) stimulates or enhances several neutrophil functions in vivo, as well as in vitro. To further explore the possible role of G-CSF in inflammation we studied the effect of rhG-CSF on the surface expression of LAM-1 on human neutrophils, both in vitro and in vivo. The expression of LAM-1 by human neutrophils was investigated by indirect immunofluorescence using flow cytometry and monoclonal antibodies anti-Leu-8 and TQ1. A whole blood analysis was performed to minimize in vitro manipulation. Most circulating human neutrophils expressed LAM-1 on the cell surface. Brief exposure of neutrophils to rhG-CSF in vitro decreased the surface expression of LAM-1. rhG-CSF down-regulated neutrophil LAM-1 expression in a time- and dose-dependent manner. Neutrophils from healthy volunteers and from patients who were receiving rhG-CSF exhibited a decreased expression of LAM-1 after rhG-CSF administration, and the expression thereafter returned or overshot the pretreatment level after stopping rhG-CSF administration. These findings indicate that rhG-CSF down-regulates the surface expression of LAM-1 on human neutrophils in vivo, as well as in vitro, and G-CSF might participate in neutrophil-endothelial cell interaction in inflamed tissue.

Antigens, CD↗

[Carrier state and comparative study of methicillin-resistant Staphylococcus aureus from the staff and patients].

The nasal carriage of Staphylococcus aureus in 529 staff was screened. S. aureus from staff and patients whose minimum inhibitory concentration (MIC) of methicillin was larger than 12.5 micrograms/ml by agar dilution was defined as Methicillin-resistant S. aureus (MRSA). Coagulase typing was performed by DENKA SEIKEN kit. Hands of ward staff were screened before and after contact with the MRSA carriers and after hand washing. The nasal acquisition rate of S. aureus and MRSA for staff was 27.6% and 8.5%. The rate of ward staff for nasal carriers of MRSA was 91.1%. Coagulase type II strains from ward staff and inpatients were dominant. In some cases MRSA was detectable after hand washing: In MRSA infection ward staff played a dangerous role as a vector.

Hand↗

[Free concentration and protein binding of ceftriaxone].

UNLABELLED: Ceftriaxone (CTRX) was administered in dose of 1 g 30 minutes intravenous drip infusion to 5 healthy volunteers. Cefpiramide (CPM) and cefotetan (CTT) were administered as control antibiotics. The serum concentrations of total and free drugs, using ultrafiltration, were assayed by bioassay and HPLC. Protein binding rates and pharmacokinetic parameters were calculated. Free concentration of antibiotics were following orders in each sampling time: CTRX greater than CTT greater than CPM. Mean free concentrations of CTRX at 0 hour and at 8 hours after intravenous drip infusion was more than 20 micrograms/ml and more than 2 micrograms/ml. Even at 24 hours after intravenous drip infusion free concentrations of CTRX were detectable. Mean half life in beta phase by HPLC was following orders: CTRX (7.5 hours) greater than CPM (5.4 hours) greater than CTT (4.7 hours). Mean protein binding rates were following orders: CPM (98%) greater than CTT (94%) greater than CTRX (92%). CONCLUSIONS: Characteristic of CTRX is high free drug concentration and long half life.

Adult↗

[Organ transplantation and laboratory tests].

The media has recently been featuring organ transplantation from various viewpoints. Furthermore, Novel Prizes 1990 for Medical & Physiological fields were awarded to Drs. JE Murray and ED Thomas, both pioneers of clinical transplantation. Our topic has been timely indeed. This symposium mainly dealt with laboratory tests vs. various types of organ transplantation. In reality though, only kidney and bone marrow transplantations have been practiced in Japan; thus, Dr. I Yokoyama, University of Pittsburgh, discussed liver transplantation. First, Dr. K Uchida lectured on the recent advancement of immunosuppressive drugs and improvement in the clinical outcome of kidney transplantation. Serum creatinine determination is the only parameter for rejection besides renal biopsy. Drs. K Miyamura & Y Morishima discussed about PCR method to detect MRD (minimal residual diseases). There are positive relationships between the remaining leukemic cells and the relapse of leukemia even though the patients are in clinical remission. Dr. H Funada dealt with the importance of "sterile room treatment" for bone marrow transplantation. It protects patients from infection, minimizes GVHD and prolongs survival time after transplantation. Dr. Yokoyama stressed the importance of back-up system, i.e. drug-monitoring, coagulation tests, pathological examination, biochemical tests, blood transfusion services for successful liver transplantations. Dr. T Fukunishi discussed the importance of developing the organ donor and coordinator system to promote kidney transplantation from cadaver. He also dealt with virus antibody tests for selecting donors. All discusssions stressed on the importance of the 24-hour laboratory back-up system performing emergency tests but no specific laboratory test for organ transplantation was necessary.

Clinical Laboratory Techniques↗

[Antibacterial activity of imipenem in combination with ampicillin against methicillin-resistant strains of Staphylococcus aureus].

UNLABELLED: Imipenem (IPM) and beta-lactams have been reported to possess a synergistic relationship in their activities against methicillin (DMPPC)-resistant strains of Staphylococcus aureus (MRSA). The purpose of this study was to determine activities of IPM and ampicillin (ABPC) singly and in combination against MRSA. Activities of the 2 antibiotics against 19 strains of S. aureus resistant to DMPPC were investigated by means of the checkerboard method, the disk diffusion technique and the killing-curve method. MICs of DMPPC against these strains determined using the agar dilution method were greater than or equal to 100 micrograms/ml and MICs of IPM and ABPC ranged from 12.5 to 100 micrograms/ml and from 12.5 to 50 micrograms/ml, respectively, when used singly. The following results were obtained with the checkerboard method: Synergistic effects and additive effects were found against 13/19 and against 6/19 strains, respectively, and no antagonistic effect was found according to the FIC (fractionary inhibitory concentration) index. The disk diffusion technique indicated synergistic results. Killing-curves with the following drug concentration combinations were examined in Mueller-Hinton broth against 5 fosfomycin(FOM)-resistant and 5 FOM-susceptible stains: (1) IPM 12.5 micrograms/ml, (2) ABPC 25 micrograms/ml, (3) IPM 12.5 micrograms/ml + ABPC 25 micrograms/ml, (4) IPM 6.25 micrograms/ml + ABPC 25 micrograms/ml, (5) IPM 6.25 micrograms/ml + ABPC 12.5 micrograms/ml, (6) IPM 6.25 micrograms/ml + ABPC 12.5 micrograms/ml + FOM (fosfomycin) 25 micrograms/ml, (7) IPM 12.5 micrograms/ml + ABPC 25 micrograms/ml + FOM 50 micrograms/ml, (8) FOM 50 micrograms/ml. The following results were obtained with the killing-curve method; (1) Synergistic effects were found against 8/10 strains and no antagonistic effect was found with the combinations of IPM and ABPC. (2) Synergistic effects were found against 3/5 strains and no antagonistic effect was found with the combinations of IPM, ABPC and FOM against 5 FOM-susceptible strains. CONCLUSIONS: IPM in combination with ABPC produced synergistic effects against MRSA. This combination therapy should be evaluated in treating MRSA infections.

Ampicillin↗

[Antibacterial activity of local anesthetics].

In order to study the antibacterial activity of local anesthetics quantitatively, we procured their minimum inhibitory concentration (MIC), killing curves and postantibiotic effect (PAE), using the standard colony of Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 14990 and Pseudomonas aeruginosa NCTC 10490. Both bupivacaine and lidocaine had bactericidal activity at a clinical concentration. MIC of the former was lower than that of the latter, and it means that bupivacaine has a greater antibacterial activity than lidocaine. At the same concentration, the commercial solutions, such as Xylocaine and Marcain, which contain preservatives, showed a greater antibacterial activity than the pure anesthetic solutions which contain no preservatives. However, the preservatives had no bactericidal activity, but weak bacteriostatic activity.

Anesthetics, Local↗

[Antibacterial activities and electron microscopic studies of imipenem in combination with fosfomycin against methicillin and fosfomycin resistant strains of Staphylococcus aureus].

UNLABELLED: Imipenem (IPM) and fosfomycin (FOM) have been reported to possess a synergistic relationship in their activities against both methicillin (DMPPC)-susceptible and -resistant strains of Staphylococcus aureus. However it was not concluded whether these antibacterial activities were bacteriostatic or bactericidal. The purpose of this report is to elucidate this point clearly. Activities of the 2 antibiotics against 15 strains S. aureus resistant to both DMPPC and FOM were investigated by means of the killing-curve method and electron microscopic studies. MICs of DMPPC and FOM against these strains determined using the agar dilution method were greater than or equal to 50 micrograms/ml and MICs of IPM by the broth dilution method ranged from 12.5 to 50 micrograms/ml. The killing-curves with the following drug concentration combinations were examined in Mueller-Hinton broth: 1. FOM 25 micrograms/ml, 2. FOM 25 micrograms/ml + IMP 1/2 MIC, 3. IPM 1MIC, 4. FOM 25 micrograms/ml + IPM 1 MIC and 5. FOM 25 micrograms/ml + IPM 2MIC. Morphological changes produced in 1 strain by 2 of the combinations, 2. FOM 25 micrograms/ml + IPM 1/2 MIC and 4. FOM 25 micrograms/ml + IPM 1MIC, were observed using scanning and transmission electron microscopy. The following results were obtained; (1) The synergistic effects were found in 6/15 strains (40%) and no antagonistic effect was found. (2) Electron microscopic observation showed that IPM in combination with FOM caused lysis of the cells. CONCLUSIONS: IPM in combination with FOM produced bactericidal and bacteriolytic effects on DMPPC-resistant S. aureus (MRSA). This combination therapy should be evaluated for FOM resistant MRSA infections.

Bacteriolysis↗

[Corneal crystalline deposits in multiple myeloma].

Two cases of multiple myeloma with corneal opacity were reported. Their chief complaint was blurred vision, and general check-up performed prior to cataract operation revealed that one case had multiple myeloma of IgG-kappa and another, of IgG-lambda type. Two corneal buttons obtained at the time of lamellar keratoplasty operations in the IgG-kappa case were studied immunohistopathologically as well as electron microscopically. Corneal opacity observed with a slit lamp was localized at the anterior stroma of both corneas. Immunohistological studies revealed that the deposit was IgG-kappa chain. Transmission electron microscopy disclosed electron-dense extracellular deposits that exhibited a honeycomb appearance and parallel linear structures with a periodicity of 12nm.

Aged↗

[Influence of human albumin on bactericidal or antibacterial activities of cephems and monobactams].

Influence of human albumin on bactericidal or antibacterial activities of 11 beta-lactams were examined. The 11 beta-lactams included second generation cephems (cefsulodin, cefotiam and cefmetazole), third generation cephems (ceftazidime, latamoxef, cefmenoxime, cefoperazone, cefotetan and cefpiramide) and monobactams (carumonam and aztreonam). The micro-broth-dilution method was used to determine antibacterial activities. Bactericidal activities were determined using the time-kill method. Used in the broth-dilution method were 2 media, MUELLER-HINTON broth (MHB) and the same medium supplemented with 5 g human albumin/d1 (MHB-A). The first experiment was to compare minimum inhibitory concentrations (MICs) determined in MHB were compared with those in MHB-A of 6 antibiotics against Staphylococcus aureus FDA 209P JC-1, of 7 antibiotics against Escherichia coli ATCC 25922 and of 5 antibiotics against Pseudomonas aeruginosa NCTC 10490. MICs using MHB-A were higher than MIC using MHB for 2 of the 6 antibiotics against S. aureus, and for all the 7 antibiotics against E. coli, and for 3 of the 5 antibiotics against P. aeruginosa. The second experiment was done to compare MICs of 5 antibiotics determined in MHB-A with those determined in MHB against 10 clinical isolates of S. aureus, of 6 antibiotics against 10 clinical isolates of Klebsiella pneumoniae and of 6 antibiotics against 10 clinical isolates of P. aeruginosa. The results obtained in the second experiment were varied for different antibiotics and different strains of organisms, and same antibiotics produced different results for different strains. MICs determined in MHB-A were lower than those in MHB for antibiotics with relatively low protein binding rates against 22 of 170 isolates tested (12.9%), whereas the former was higher than the latter against 103 out of 170 isolates tested (60.6%). MICs of antibiotics with relatively high protein binding rates showed an opposite trend. In the third experiment, time-kill curves were determined in the 2 media for 5 antibiotics against S. aureus FDA 209P JC-1, for 6 drugs against E. coli ATCC 25922 and for 5 drugs against P. aeruginosa NCTC 10490. The concentrations of these antibiotics used were 1/2 x MIC, 1 x MIC and 2 x MIC. MICs determined in the first experiment were used here. Time-kill curves determined in MHB-A didn't reflect MICs determined in MHB. Using MHB-A, antibiotics with lower MICs determined in MHB-A showed bactericidal activities in lower concentrations. Human albumin influenced antibacterial or bactericidal activities of beta-lactams.(ABSTRACT TRUNCATED AT 400 WORDS)

Albumins↗

[Effects of cephem antibiotics on ethanol metabolism].

Disulfiram-like reactions have been reported in patients receiving cephem antibiotics which possess a mercaptomethyltetrazole (Me-TZ) side chain in their molecular structure. The present study focused on the elucidation of the relationship between the formation of Me-TZ and its inhibitory action on alcohol metabolism after treatment with the cephem antibiotics. The cumulative urinary excretion of Me-TZ was determined in healthy volunteers and laboratory animals after i.v. administration of the cephem antibiotics: cefmetazole (CMZ), cefoperazone (CPZ) and latamoxef (LMOX). In humans, monkeys and rodents, the extent of urinary excretion of Me-TZ was found in the order of CPZ greater than LMOX greater than CMZ-treatment. To assess their influences on dehydrogenation of ethanol (EtOH) and acetaldehyde (AcH), rats and monkeys were treated with a single or multiple i.v. dose of Me-TZ and cephem antibiotics prior to the EtOH treatment. The blood EtOH levels were not affected with either the Me-TZ or the cephem pretreatments. On the contrary, the AcH levels were significantly elevated with each of the pretreatments. The dose response curves for AcH levels showed parallel lines corresponding to the urinary excretion of Me-TZ, i.e., CPZ greater than LMOX greater than CMZ-treatment. These results suggest that there are some differences in the disulfiram-like reactions among animal species and antibiotics, which will be attributed to the intrinsic distribution and stability of each of the antibiotics in the body.

Acetaldehyde↗