New insights into interactions between the human PTH/PTHrP receptor and agonist/antagonist binding.

We prepared a polyclonal antiserum [Ab-(88-97)] against residues 8-97 of the NH2-terminal tail of the human (h) parathyroid hormone (PTH)/PTH-related protein (PTHrP) receptor. Ab-(88-97) bound specifically to the receptor, as assessed by fluorescence-activated cell sorter analysis of HEK C21 cells, which stably express approximately 400,000 hPTH/PTHrP receptors per cell. Unlike PTH, Ab-(88-97) binding did not elicit either adenosine 3',5'-cyclic monophosphate or intracellular calcium concentration signaling responses in these cells. Incubation of C21 cells for 90 min at 4 degrees C with hPTH-(1-34) plus antiserum reduced the Ab-(88-97) binding to the cells by up to 40-50% of control values in a PTH concentration-dependent fashion with a half-maximal effective concentration of approximately 5 nM. The decrease in Ab-(88-97) binding caused by hPTH-(1-34) was completely reversed by coincubation with hPTHrP-(7-34). We conclude that residues 88-97 of the hPTH/PTHrPR are involved, either directly or indirectly, in agonist but not antagonist binding to the receptor.

Beta-adrenergic receptor kinase-1 acutely regulates PTH/PTHrP receptor signalling in human osteoblastlike cells.

To investigate whether G protein-coupled receptor kinases (GRKs) are involved in the regulation of the PTH/PTHrPR, we have established mutant SaOS-2 cells which stably overexpress (> 10-20-fold) a dominant negative form of the beta-adrenergic receptor kinase-1 (beta ARK-1). Acute (< or = 2 h) incubation with hPTH (1-34) induced significantly less (by up to 50%) downregulation of the PTH/PTHrPR in beta ARK-1 mutant SaOS-2 cells than observed in wild-type cells. Pretreatment of wild-type cells with PTH for 2 h induced homologous cAMP desensitisation to a second challenge with PTH, while the effect was blunted by up to 60% in beta ARK-1 mutant cells. We conclude that activation of beta ARK-1 (or a closely related GRK) is a critical component of the acute phase (< or = 2 h) of PTH-induced receptor downregulation and homologous cAMP desensitisation of the PTH/PTHrPR.

[Antimicrobial activities of cefozopran against Streptococcus pneumoniae from children].

In order to evaluate antimicrobial activity of cefozopran (CZOP), minimum inhibitory concentrations (MICs) of CZOP and control drugs were determined against Streptococcus pneumoniae from children that were isolated from October of 1995 to January of 1996. Determinations were made for the detection frequency of penicillin-insensitive or resistant strains in biovar utilizing hydrolysis products, and for the correlation of antibacterial susceptibility and macrolides (MLs)-resistant patterns. The results are summarized as follows; 1. MIC90 of CZOP was < or = 0.025 micrograms/ml against benzylpenicillin (PCG)-susceptible S. pneumoniae (PSSP, 50 strains). MIC distribution of CZOP against these strains was approximately equal to that of PCG, and showed stronger activities of CZOP than those of ceftazidime (CAZ), flomoxef (FMOX) and erythromycin (EM). 2. MIC90 of CZOP was 0.39 micrograms/ml against 50 strains of PCG-insensitive S. pneumoniae (PISP) and PCG-resistant S. pneumoniae (PRSP). Antimicrobial activities of CZOP against these strains were stronger than those of CAZ, FMOX, PCG and EM. 3. These isolated strains of PISP and PRSP did not show type III biovar, but showed types I and II. The detection frequency of MLs-constitutive resistant strains were high among type III PSSP and those of MLs-inductive resistant strains were high among types I and II PISP and PRSP. These data suggested that CZOP had strong antimicrobial activities against multiple drug resistant S. pneumoniae including penicillin-resistant strains. CZOP will be effective against S. pneumoniae which often are causative organisms in infections of children.

[Antimicrobial activities of tosufloxacin against recently obtained clinical isolates].

To evaluate antimicrobial activities of tosufloxacin (TFLX), minimum inhibitory concentrations (MICs) of TFLX and other drugs were determined against clinical isolates that were obtained in our laboratory from February of 1993 to January of 1994 (Period I), and from February of 1995 to January of 1996 (Period II). The results are summarized as follows: 1. Compared to MIC90's reported by others for TFLX in the 1980's, those obtained by us against beta-streptococci, Streptococcus pneumoniae, Peptostreptococcus spp., Haemophilus influenzae and Salmonella spp. were similar to, but those obtained against other bacteria were higher than those reported values. 2. Detection frequencies of resistant strains to TFLX were compared between Period I and Period II. MIC90's of TFLX against Staphylococcus spp., Morganella morganii, Providencia spp., Pseudomonas aeruginosa, beta-streptococci, S. pneumoniae and Peptostreptococcus spp. were lower in Period II than in Period I. TFLX-insensitive or -resistant H. influenzae were found among strains isolated in either of the Periods. 3. Most of the TFLX-resistant Gram-negative organisms tested were also resistant to other NQ's. 4. TFLX showed strong antimicrobial activities against penicillin-resistant S. pneumoniae.

Regulation of HSP70 by PTH: a model of gene regulation not mediated by changes in cAMP levels.

Parathyroid hormone (PTH) activates both adenylate cyclase and phospholipase C in target cells, and cloned PTH/PTH-related protein (PTHrP) receptor can mediate both responses when expressed in host cells such as LLC-PK1 renal epithelial cells. Because calcitonin (CT) is known to augment 70-kDa heat shock protein (HSP70) mRNA by an adenosine 3',5'-cyclic monophosphate (cAMP)-independent mechanism in LLC-PK1 cells, we examined regulation of HSP70 transcription by PTH in these cells. Like CT, human PTH-(1-34) [hPTH-(1-34); 10(-10) to 10(-7) M)] increased porcine HSP70 mRNA and human HSP70 promoter-chloramphenicol acetyltransferase (CAT) expression within 4 h in LLC-PK1 cells that stably express > or = 100,000 PTH/PTHrP receptors per cell. The effect of PTH on HSP70 mRNA was not mimicked by cAMP analogues, forskolin, phorbol esters, Ca2+ ionophores, or alpha-thrombin; was insensitive to pertussis toxin; and was not due to increased mRNA stability. The upregulation of HSP70 gene transcription by hPTH (and CT) was clearly observed even after deletion of the functional heat shock consensus element in the promoter region of the human HSP70/CAT reporter. Upregulation of HSP70 transcription via endogenous PTH receptors also was observed in the osteoblastic cell lines SaOS-2 and ROS 17/2.8. Regulation of HSP70 gene transcription by PTH may be a common cellular response to the hormone, which, in some cells, may not be mediated by activation of adenylate cyclase or protein kinase C.

[Antibacterial activities of combination uses of isepamicin and beta-lactams in vitro against clinically isolated strains. Part 3. The results against Pseudomonas aeruginosa].

We investigated antibacterial activities of combination uses of isepamicin (ISP) and beta-lactams in vitro against Pseudomonas aeruginosa, and the following conclusions were obtained. 1. ISP + piperacillin, ISP + ceftazidime, ISP + aztreonam, ISP + imipenem and ISP + panipenem against P. aeruginosa showed strong combined effects. 2. The minimum inhibitory concentrations (MICs) of these combinations were low and dependent on concentrations of ISP. And strong antibacterial activities were observed at ISP concentrations of sub-MIC levels. These results were similar to the results of previous reports, parts 1 and 2. 3. Concentrations of ISP sufficient to lower MIC90 values when by combined with beta-lactam agents were 4 approximately 8 micrograms/ml. These effects made it possible to lower the ISP dose to 400 mg at a single dose and the enhancement of activities by combinations resulted in strong antibacterial activities against multiple drug resistant stains at sub-MIC levels of ISP. Strong antibacterial activities were also obtained against beta-lactams-resistant strains of ISP-susceptible strains when ISP was combined with beta-lactam agents. 4. All results reported in parts 1 approximately 3 indicated that no antagonisms were produced by combining ISP + penicillins, ISP + cephems, ISP + monobactams and ISP + carbapenems against Staphylococcus aureus, Enterobacteriaceae and P. aeruginosa. These combinations showed strong antibacterial activities that were enhanced synergistically with wider spectra.

[Antimicrobial activities of meropenem against clinically isolated strains. The result against strains isolated from blood and cerebrospinal fluid].

In order to evaluate the antimicrobial activity of meropenem (MEPM), minimum inhibitory concentrations (MICs) of MEPM and control drugs were determined against clinical isolates from blood and cerebrospinal fluid that were obtained from January, 1993 to December, 1994. The results are summarized as follows; 1. The MIC-range, 50% MIC (MIC50) and 90% MIC (MIC90) of MEPM were equal to those of imipenem (IPM) and panipenem (PAPM) against Streptococcus pneumoniae including benzylpenicillin (PCG)-insensitive or -resistant S. pneumoniae, Streptococcus agalactiae and Listeria monocytogenes which are Gram-positive strains, and were stronger than those of ampicillin (ABPC) and cefotaxime (CTX). 2. The MIC-range, MIC50 and MIC90 of these 3 drugs of carbapenems (MEPM, IPM and PAPM) were different against Escherichia coli and Haemophilus influenzae which are Gram-negative strains. The MIC90 of MEPM was < or = 0.025 microgram/ml and those of IPM and PAPM were 0.2 microgram/ml against E. coli. The MIC90 of MEPM was 0.1 microgram/ml, that of IPM was 25 micrograms/ml and that of PAPM was 6.25 micrograms/ml against H. influenzae. Thus, the antimicrobial activity of MEPM was stronger than those of IPM and PAPM. The MIC90's of IPM and PAPM against H. influenzae were high with the MIC of IPM at 12.5 approximately 25 micrograms/ml and the MIC of PAPM at 3.13 approximately 12.5 micrograms/ml against 3 IPM-resistant strains among 17 isolates. 3. The MIC90 of ABPC was 0.39 microgram/ml and that of CTX was 0.1 microgram/ml against 20 strains of S. pneumoniae including 6 strains of PCG-insensitive or resistant S. pneumoniae. The MIC90 of ABPC and CTX were higher than those of 3 carbapenem drugs. There were E. coli of 8 strains with ABPC-high resistance (the MIC of ABPC was > 100 micrograms/ml) and 2 strains for which MIC of CTX were 0.39 microgram/ml and 3.13 micrograms/ml. It was found that 29.4% of H. influenzae were beta-lactamase producing strains. 4. It appeared that antimicrobial activities of carbapenems, particularly MEPM were strong against clinical isolates from blood and cerebrospinal fluid. MEPM will be first choice drug by empiric therapy in infections including sepsis and purulent meningitis.

Inositol 1-,4-,5-trisphosphate-dependent Ca2+ signaling by the recombinant human PTH/PTHrP receptor stably expressed in a human kidney cell line.

We previously reported the preparation and partial characterization of a series of human embryonic kidney cell lines (HEK-293) stably expressing various numbers of the recombinant human (h) parathyroid hormone (PTH)/PTH-related protein (PTHrP) receptor (Rc). Using this expression system we examined ligand (PTH or PTHrP) binding characteristics and cyclic AMP responsiveness. We have now extended these studies to investigate the calcium signal transduction pathways activated by the hPTH/PTHrP Rc. In parental HEK-293 cells, which lack endogenous PTH/PTHrP Rc, incubation with hPTH(1-34) had no effect on cytosolic free Ca2+ concentration [Ca2+]i. In HEK-293 clone C-21, stably expressing approximately 400,000 Rc/cell, PTH stimulated an increase in [Ca2+]i by Ca2+ release from intracellular stores; PTH released Ca2+ exclusively from the IP3 sensitive Ca2+ pool. Unlike previous studies, the ability of PTH to elicit both cAMP responses and [Ca2+]i transients occurred over a wide range of Rc numbers (between 400,000 and 3000 Rc/cell); both responses were always observed at PTH concentrations in the same dose range although the magnitude of the responses decrease with Rc number. Pretreatment of C-21 cells with pertussis toxin for 24 h, which significantly enhanced PTH-stimulated cAMP accumulation, did not modulate PTH-stimulated [Ca2+]i transients. At each PTH concentration tested which resulted in increased cAMP levels, there was also an increase in [Ca2+]i transients. Treatment of C-21 cells with a battery of midregion and C-terminal PTH or PTHrP peptides showed no effect on either [Ca2+]i transients or cAMP accumulation, indicating a lack of functional interactions between these peptides and the form of the hPTH/PTHrP Rc stably expressed in these cells. Immunological analysis of G-protein expression demonstrated the presence of Gs, Gi, and Gq in all parental and transfected cells lines examined. Taken together, these data demonstrate that the hPTH/PTHrP Rc, stably expressed in HEK-293 cells, elicits responses in both the cAMP and IP3-dependent [Ca2+]i pathways and is responsive only to N-terminal PTH/PTHrP peptides.

[Antibacterial activities of combination uses of isepamicin and beta-lactams in vitro against clinically isolated strains. Part 2. The results against enterobacteriaceae].

We investigated antibacterial activities of combination uses of isepamicin (ISP) and beta-lactams in vitro against Klebsiella pneumoniae and Enterobacter cloacae, and the following conclusions were obtained. 1. ISP+cefazolin, ISP+cefotiam and ISP+flomoxef against K. pneumoniae and ISP+piperacillin, ISP+ceftazidime, ISP+aztreonam, ISP+imipenem and ISP+panipenem against E. cloacae showed strong combined effects. 2. The minimum inhibitory concentrations (MICs) of these combinations were low due to the dependence of ISP concentrations. Strong antibacterial activities were observed at sub-MIC levels of ISP. These combined effects were stronger than those against Staphylococcus aureus described in the first report at sub-MIC levels of ISP. 1/4 MIC approximately 1/8 MIC of ISP showed enhanced activities of beta-lactams. Similarly strong combined effects were observed against both beta-lactam-sensitive and -resistant strains.

[Antimicrobial activities of clarithromycin against clinical isolates].

To examine the antimicrobial activity of clarithromycin (CAM) against strains clinically isolated from outpatients in 1994, minimum inhibitory concentrations (MICs) were determined for CAM and the control drugs. The results were as follows; 1. MIC50 and MIC90 of CAM were similar to those investigated in 1980's against many bacterial species. 2. CAM showed strong antimicrobial activities against beta-lactamase producing Moraxella subgenus Branhamella catarrhalis, Bordetella pertussis, Campylobacter jejuni subsp. jejuni and Peptostreptococcus spp. 3. It appears that resistance to MLs including CAM is increasing among Streptococcus pneumoniae.

[Antimicrobial activities of meropenem against clinically isolated strains].

In order to evaluate antimicrobial activity of meropenem (MEPM), minimum inhibitory concentrations (MICs) of MEPM and control drugs were determined against clinical isolates in 1993. The results were as follows; 1. Antimicrobial activities of MEPM against Gram-positive bacteria were stronger than those of cephems (CEPs), were approximately equal to those of panipenem (PAPM), and were weaker than those of imipenem (IPM). 2. Carbapenems showed strong antimicrobial activities against Enterobacteriaccae, glucose non-fermentative Gram-negative rods and Bacteroides fragilis group that were multiple drug resistant including the third generation CEPs. Antimicrobial activities of MEPM against these organisms were stronger than those of IPM and PAPM. 3. MIC-ranges of MEPM against Enterobacteriaceae and Haemophilus influenzae were lower than those of IPM and PAPM. We observed that MEPM had better permeability into the cells of H. influenzae, higher affinities to 3 to 5 different penicillin-binding protein and high stability against beta-lactamase than those of IPM and PAPM.

[Antibacterial activities of combination uses of isepamicin and beta-lactams in vitro against clinically isolated strains. Part 1. Activities against Staphylococcus aureus].

In order to evaluate antibacterial activities of combination uses of isepamicin (ISP) and beta-lactams in vitro, minimum inhibitory concentrations (MICs) these drugs were examined singly and in combination against clinically isolated Staphylococcus aureus. The results are summarized as follows; 1. MICs of ISP + cefazolin (CEZ), ISP + cefotiam (CTM) and ISP + flomoxef (FMOX) were low and the activities against methicillin (DMPPC)-susceptible S. aureus (MSSA) were dependent on the concentration of ISP. Combined effects were observed when the concentrations of ISP were at sub-MIC levels (1/2 approximately 1/4 concentrations). 2. MICs of ISP + CEX, ISP + CTM, ISP + FMOX, ISP + imipenem and ISP + panipenem were low and the activities against DMPPC-resistant S. aureus (MRSA) were dependent on the concentration of ISP, and were similar to those against MSSA. Combined effects were observed when the concentrations of ISP were at sub-MIC levels of ISP. Lower MIC50 or MIC90 was observed at ISP concentrations of 4 approximately 16 micrograms/ml. 3. The blood Cmax of ISP exceeded 20 micrograms/ml at one-time administration of ISP 400 mg, and these results suggested that antibacterial activities of combination uses of ISP and beta-lactams was clinically effective against MRSA infections.

[Antibacterial activities of combination uses of cefpirome with various antibiotics in vitro against clinically isolated glucose non-fermentative gram-negative rods: part 1. the results against Pseudomonas aeruginosa].

In order to evaluate antibacterial activities of combination uses of cefpirome (CPR) and various antibiotics in vitro, minimum inhibitory concentrations (MICs) of CPR alone and combinations of CPR+other drugs against freshly isolated clinical strains of Pseudomonas aeruginosa. The results are summarized as follows; 1. Combined effects of CPR+beta-lactams, piperacillin (PIPC), aztreonam (AZT), imipenem (IPM) showed wider antibacterial spectra and stronger antibacterial activities than CPR alone with drugs concentrations of CPR and other drugs at sub-MIC levels. At concentrations of sub-MIC levels, antibacterial effects of CPR+PIPC and CPR+AZT combination were strong but CPR+IPM was weaker than those of the former two combinations. It appeared that stronger effects were demonstrated by some combinations against strains that were susceptible to both drugs of combination, but little additive effects were shown against strains that were resistant to both drugs. Antibacterial effect of CPR+fosfomycin combination was the same as those of CPR+PIPC and CPR+AZT combinations. 2. Combined effects of CPR+aminoglycosides (AGs), gentamicin, tobramycin, amikacin showed wider antibacterial spectra and stronger antibacterial activities at sub-MIC levels of CPR or ATs. The effect against CPR-resistant strains was same. But the combined effect was weak against AGs-resistant strains. 3. Effectiveness of combinations of CPR+beta-lactams and CPR+AGs depended on drug susceptibilities of strains tested. We cannot estimate effects of those combinations without investigating drug susceptibility of bacteria being tested. 4. In none of the combinations tested, antagonism was observed.

[Antimicrobial activities of ceftriaxone against fresh, clinically isolated strains].

In order to evaluate antimicrobial activity of ceftriaxone (CTRX), minimum inhibitory concentrations (MICs) of CTRX and control drugs were determined against clinically isolated strains including those from purulent meningitis and liver and biliary tract infections in 1995. The results are summarized as follows; 1. MIC90 of CTRX was 0.05 micrograms/ml against benzylpenicillin (PCG)-insensitive Streptococcus pneumoniae or PCG-resistant S. pneumoniae and it was < or = 0.025 micrograms/ml against beta-lactamase producing strains of Haemophilus influenzae. Antimicrobial activities of CTRX against these strains were stronger than control drugs. 2. MIC distribution of CTRX was in a lower concentration range than those of ceftazidime and flomoxef against extend broad-spectrum beta-lactamase (EBLA)-producing Escherichia coli and Klebsiella pneumoniae subsp. pneumoniae. 3. These results suggested that CTRX will be effective against community-acquired pneumonia, purulent meningitis and liver & biliary tract infections.

[Antimicrobial activities of clavulanic acid/ticarcillin against clinical isolates].

In order to investigate antimicrobial activities of clavulanic acid/ticarcillin (CVA/TIPC) against Escherichia coli, Enterobacter spp. and Pseudomonas aeruginosa in 1992 and 1994, beta-lactamase activities were analyzed and minimum inhibitory concentrations (MICs) were determined including those of the control drugs. The results are as follows; 1. Compared to a report in 1980, the MIC distributions of CVA/TIPC against E. coli and P. aeruginosa did not show large differences. We found, however, that CVA/TIPC-resistant strains increased among Enterobacter spp. 2. Almost all of CVA/TIPC-resistant strains of Enterobacter spp. were also resistant to cephems and new quinolones, thus they were multiple drug resistant. 3. CVA/TIPC showed strong antimicrobial activities against penicillinase producing E. coli.

[Antimicrobial activities of cefepime against clinically isolated strains].

In order to evaluate antimicrobial activity of cefepime (CFPM), minimum inhibitory concentrations (MICs) of CFPM and other drugs were determined against clinical isolates that were obtained in 1994. 1. CFPM showed a wide antibacterial spectrum against Staphylococcus spp. and glucose non-fermentative Gram-negative rods ((G)NF-GNR). Antimicrobial activities of CFPM against Staphylococcus spp. were stronger than those of ceftazidime (CAZ) and somewhat stronger than those of cefotaxime (CTX), and antimicrobial activity of CFPM against Pseudomonas aeruginosa was same as that of CAZ. 2. Antimicrobial activities of CFPM against almost all of Enterobacteriaceae were stronger than those of CAZ and CTX. And CFPM showed strong antimicrobial activities against CAZ-resistant Escherichia coli, Citrobacter freundii and Enterobacter spp. 3. Antimicrobial activities of CFPM were weaker than those of CAZ against some of strains of Klebsiella oxytoca, beta-lactamase high producing strains of Moraxella subgenus Branhamella catarrhalis and than those of CTX against beta-lactamase high producing strains of Prevotella spp. 4. The feature of new cephems was demonstrated in that CFPM had wider antibacterial spectrum than cephems of previous genenations against Staphylococcus spp. and (G)NF-GNR and CFPM showed strong antimicrobial activities against almost all of oxacephem-resistant Enterobacteriaceae.

[Antimicrobial activities of clavulanic acid/amoxicillin against freshly isolated clinical strains from outpatients].

In order to investigate antimicrobial activities of clavulanic acid/amoxicillin (CVA/AMPC) against freshly isolated clinical strains obtained in 1995, beta-lactamase activities and minimum inhibitory concentration (MICs) were determined including those of the control drugs. The results are summarized as follows; 1. Detection frequencies of beta-lactamase producing strains were as follows: methicillin-susceptible Staphylococcus aureus subsp. aureus (MSSA, 90.0%), Haemophilus influenzae (22.0%), Moraxella subgenus Branhamella catarrhalis (100.0%), Escherichia coli (100.0%), Klebsiella pneumoniae subsp. pneumoniae (100.0%) and Neisseria gonorrhoeae (14.0%). It appeared that beta-lactamases produced by these strains were mostly penicillinase or enzyme of similar that. 2. Antimicrobial activities of CVA/AMPC against beta-lactamase producing strains were stronger than those of AMPC, and MIC90 of CVA/AMPC against benzylpenicillin (PCG)-insensitive or resistant Streptococcus pneumoniae was lower than those of sultamicillin, cefaclor and cefpodoxime. 3. CVA showed strong beta-lactamase inhibitory effect against M.(B.) catarrhalis of direct and indirect pathogenicity. We can expect CVA/AMPC to negate or decrease the influence of indirect pathogenicity.

Signaling by N- and C-terminal sequences of parathyroid hormone-related protein in hippocampal neurons.

Parathyroid hormone-related protein (PTHrP) is synthesized in the brain, and a single type of cloned receptor for the N-terminal portion of PTHrP and PTH is present in the central nervous system. Nothing is known about the physiological actions or signaling pathways used by PTHrP in the brain. Using cultured rat hippocampal neurons, we demonstrate that N-terminal PTHrP[1-34] and PTH[1-34] signal via cAMP and cytosolic calcium transients. The cAMP response showed strong acute (< or = 6 h) homologous and heterologous desensitization after preincubation with PTHrP or PTH. In contrast, the acute calcium response did not desensitize after preincubation with PTHrP; in fact, preincubation dramatically recruited additional responsive neurons. Unexpectedly, C-terminal PTHrP[107-139], which does not bind or activate the cloned PTH/PTHrP receptor, signaled in neurons via cytosolic calcium but not cAMP. Although some neurons responded to both PTHrP[1-34] and PTHrP[107-139], others responded only to PTHrP[1-34]. We conclude that certain hippocampal neurons exhibit dual signaling in response to PTHrP[1-34] and that some neurons have a receptor for C-terminal PTHrP that signals only via cytosolic calcium.

[Frequency of clinical isolation of glucose non-fermentative gram-negative rods and their susceptibilities to antibacterial agents].

A comparison was made for frequencies of isolation o glucose non-fermentative Gram-negative rods ((G)NF-GNR) from clinical specimens during a period from July, 1986 to June, 1987 (the first period) and that from January, 1994 to December, 1994 (the second period). Also, minimum inhibitory concentrations of principal drugs were determined against these isolates. The obtained results are summarized as follows: 1. Thirty four (34) species of (G)NF-GNR were found from 35,200 clinical specimens in the two periods. Numbers of strains of (G)NF-GNR obtained were 4,575 during the first period and 4,704 during the second period, thus no significant difference existed in numbers of strains isolated in the two periods. 2. Among the 34 species to which the 4,704 strains were classified into, Pseudomonas aeruginosa comprised 68.4%, Stenotrophomonas maltophilia 6.9%, Acinetobacter baumannii 5.6%, Burkholderia cepacia 3.1%, Acinetobacter Iwoffii 2.6%, Alcaligenes xylosoxidans subsp. xylosoxidans 2.4%, Flavobacterium indologenes 1.7%, Pseudomonas putida 1.1%, Acinetobacter junii 1.1% and Moraxella subgenus Moraxella lacunata 0.9%. When these frequencies of isolation were compared with those in the first period, it was found that B. cepacia decreased significantly (P < 0.01) and that S. maltophilia increased significantly (P < 0.001). 3. MIC determinations revealed multiple drug resistance strains in many different species of bacteria. Minocycline, however, were active against many such strains, and ofloxacin was found to have strong antibacterial activity against some strains.

[Antimicrobial activities of norfloxacin against clinical isolates from ocular infections].

In order to evaluate antimicrobial activity of norfloxacin (NFLX), minimum inhibitory concentration (MICs) of NFLX and control drugs were determined against clinical isolates from ocular infections that were obtained in our laboratory from July, 1993 to December, 1994. The results are summarized as follows; 1. Compared to MIC distributions of NFLX against clinical isolates from ocular infections studied in 1986 and 1987, the MIC80 of NFLX against Corynebacterium spp., Enterobacter spp., Serratia spp., Burkholderia cepacia, Flavobacterium spp., Alcaligenes spp. increased 8 times. Almost all of NFLX-resistant strains among them were ofloxacin (OFLX)-resistant, new quinolones resistant strains, and a part of them were aminoglycosides, beta-lactams-resistant as well, thus all of these strains were multiple drug resistant. 2. MIC of NFLX against Pseudomonas aeruginosa were lower than that of OFLX. 3. NFLX showed strong antimicrobial activities against so-called "particular bacteria" including Staphylococcus aureus subsp. aureus, Moraxella spp., Haemophilus spp., and P. aeruginosa from ocular infections. And MIC80 of NFLX against these bacteria was 0.05-1.56 microgram/ml. We observed that NFLX eye drops was administered so that concentrations above the MIC against these clinical isolates were maintained.