In vitro and in vivo activity of DL-8280, a new oxazine derivative

DL-8280, 9-fluoro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-2,3-dihydro-7H- pyrido-(1,2,3-de)1,4-benzoxazine-6-carboxylic acid, is a new nalidixic acid analog with a broad spectrum of antibacterial activity against gram-negative and gram-positive bacteria, including obligate anaerobes. The activity of DL-8280 against Enterobacteriaceae, Pseudomonas aeruginosa, Haemophilus influenzae, Neisseria gonorrhoeae, and Clostridium perfringens was roughly comparable to that of norfloxacin and far exceeded that of pipemidic acid and nalidixic acid. DL-8280 had greater activity against Staphylococcus spp., Streptococcus spp., Pseudomonas maltophilia, Acinetobacter spp., and Bacteroides fragilis than did norfloxacin, pipemidic acid, and nalidixic acid. Nalidixic acid-resistant Enterobacteriaceae, ampicillin-resistant gonococci, and clindamycin-resistant obligate anaerobes were also susceptible to DL-8280. The activity of DL-8280 was affected very little by inoculum size, and its action was bactericidal at two times the minimal inhibitory concentrations at most. Administered orally to mice experimentally infected with Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Proteus mirabilis, Serratia marcescens, or P. aeruginosa, DL-8280 was 2 to 7 times more effective than norfloxacin and 7 to more than 50 times more active than pipemidic acid.

Hypouricemic effect of the novel xanthine oxidase inhibitor, TEI-6720, in rodents

We investigated the xanthine oxidase/xanthine dehydrogenase inhibitory activity and hypouricemic effect of a newly synthesized xanthine oxidase/xanthine dehydrogenase inhibitor, TEI-6720, 2-(3-cyano-4-isobutoxyphenyl)-4-methyl-5-thiazole-carboxylic acid, and compared its effects with those of allopurinol in rodents. TEI-6720 was found to inhibit bovine milk xanthine oxidase, and mouse liver and rat liver xanthine oxidase/xanthine dehydrogenase with IC50 values of 1.4, 1.8 and 2.2 nM, respectively. On bovine milk xanthine oxidase, TEI-6720 exhibited mixed-type inhibition and the Ki value was 0.7 nM. TEI-6720 displayed prolonged urate-lowering activity in normal mice and rats. We evaluated the hypouricemic effect of TEI-6720 on hyperuricemia induced by the uricase inhibitor, potassium oxonate (250 mg/kg s.c., 1 h before the test drugs), and measured the total molarity of both serum allantoin and urate in rats. Oral TEI-6720 and allopurinol had a hypouricemic effect 2 h after their administration to oxonate-pretreated rats with ED50 values of 1.5 and 5.0 mg/kg, respectively. Both compounds also reduced the combined molarity of uric acid and allantoin in rats. The ED50 values of TEI-6720 and allopurinol were 2.1 and 6.9 mg/kg p.o., respectively. These results suggest that TEI-6720 may be useful for the treatment of hyperuricemia.

Structure-epileptogenicity relationship of quinolones with special reference to their interaction with gamma-aminobutyric acid receptor sites

The relationship between the chemical structure and epileptogenic activity of quinolones was investigated. When the quinolones were administered intravenously to mice concomitantly with oral biphenylacetic acid, a major metabolite of the nonsteroidal antiinflammatory drug fenbufen, enoxacin, norfloxacin, ciprofloxacin, and pipemidic acid, which have an unsubstituted piperazine moiety at the 7 position of their parent nuclei, provoked clonic convulsions and subsequent death at doses of 6.25 mg/kg or more in a dose-dependent manner. AM-1091 and T-3262, which have an unsubstituted aminopyrrolidine moiety at their 7 positions, were less epileptogenic than the compounds listed above were. In contrast, ofloxacin, AT-4140, and nalidixic acid, which have piperazine substituted with methyl group(s) or no piperazine moiety at their 7 positions, never induced convulsions, even at doses of 100 mg/kg. Lomefloxacin, which has a 3-methyl piperazine, however, provoked convulsions at doses of 6.25 mg/kg or more. In the presence of biphenylacetic acid, all the test quinolones except nalidixic acid competitively inhibited [3H]muscimol binding to receptor sites for gamma-aminobutyric acid (GABA) in vitro. Nalidixic acid did not inhibit the binding at all, even at the highest concentration tested, i.e., 10(-4) M. The 50% inhibition doses for [3H]muscimol binding varied within 4 orders of magnitude or more, between 10(-8) to more than 10(-4) M for various compounds, and there was a close correlation between the epileptogenic activities of quinolones and their inhibitory potencies for [3H]muscimol binding to GABA receptor sites. These results indicate that the epileptogenic activity of quinolones possibly relates to the GABA-like structures of substituents at their 7 positions, which act as antagonists of GABA receptors.

Significance of invasion to the muscularis mucosae on the progression of superficial bladder cancer

OBJECTIVE

We tried to determine the significance of invasion to the muscularis mucosae on the progression of superficial bladder cancer.

METHODS

We subclassified superficial bladder cancer showing lamina propria invasion into two groups: with (pT1b) or without cancer invasion to or near the muscularis mucosae (pT1a).

RESULTS

Of 164 bladder cancers, 76 showed no lamina propria invasion and 88 did. In the tumors with lamina propria invasion, 60 were diagnosed as pT1a and 28 as pT1b. The progression rate of pT1b cancer (53.5%) was significantly higher than that of pT1a cancer (6.7%) (P < 0.01). Regardless of size, number, or grade of tumor, the progression rate of pT1b cancer was significantly higher than that of pT1a cancer (P < 0.01).

CONCLUSIONS

We stress that patients with superficial cancer invading to or near the muscularis mucosae should be followed up carefully after transurethral resection.

Relationship between serum prostate specific antigen and histological prostatitis in patients with benign prostatic hyperplasia

The relationship between the serum values of prostate specific antigen (PSA) and the extent of histological prostatitis was investigated in 42 patients undergoing transurethral resection of the prostate for benign hyperplasia (BPH) without clinical evidence of prostatitis. Histological prostatitis was divided into three groups: acute, chronic-active, and chronic-inactive inflammation. The extent of histological prostatitis was expressed as the number of prostatic acinar and ductal glands with inflammatory infiltrate per total number of glands (%). The serum PSA values significantly correlated with the extent of acute and chronic-active prostatitis (correlation coefficient r = 0.765 and 0.656, P < 0.01). A relationship between PSA values and the extent of chronic-inactive prostatitis was not found. In the immunohistochemical study, prostatic epithelial cells with acute and chronic-active inflammation showed negative staining for PSA antigen. These results indicate that histological acute and chronic-active prostatitis is considered an important factor for inducing the high increase in serum PSA values via the leak phenomenon.

Schistosoma mansoni infection reduces severity of collagen-induced arthritis via down-regulation of pro-inflammatory mediators

Various experimental and epidemiological studies have demonstrated that helminth infections affect outcomes of allergic or autoimmune disorders. Here, we examined the effects of Schistosoma mansoni infection on mouse collagen-induced arthritis, one of the most widely used animal models for rheumatoid arthritis. Male DBA/1 mice were infected with S. mansoni 2 weeks prior to being immunized with type II collagen (IIC). Cytokine mRNA expression in mouse paws, cytokine production by ConA-stimulated spleen cells, and anti-IIC antibodies were evaluated in addition to the severity of arthritis. S. mansoni infection significantly reduced the severity of arthritis. Anti-IIC IgG and IgG2a levels were lower in infected than uninfected mice. With regard to cytokine producing potentials in the infected mice, the down-regulation of Th1 (IFNgamma) and pro-inflammatory cytokines (TNFalpha and IL-17A), and up-regulation of Th2 (IL-4) and an anti-inflammatory cytokine (IL-10) were observed.In addition, real-time PCR revealed that the augmentation of pro-inflammatory mediators such as IL-1 beta, IL-6 and receptor activator of NFkappaB ligand in inflamed paws was abrogated by S. mansoni infection [corrected]. In conclusion, schistosome infection reduced the severity of autoimmune arthritis via systemic and local suppression of pro-inflammatory mediators, suggesting the potential of parasite-derived materials as therapeutic agents against rheumatoid arthritis.

In vitro activity of DR-3355, an optically active ofloxacin

DR-3355, the S-(-)-isomer of ofloxacin, was generally twice as potent as ofloxacin against a variety of gram-positive and gram-negative pathogens, and its action was bactericidal. The compound was characterized by having the highest level of activity against staphylococci, Bacteroides fragilis, and Peptococcus spp. of the fluorinated quinolones tested, including ofloxacin, ciprofloxacin, fleroxacin, and NY-198. The activity of DR-3355 was not affected by different media, inoculum size, or human serum, but decreased under acidic conditions at pH 5.0 or in human urine.

Antimicrobial activity of DU-6859, a new potent fluoroquinolone, against clinical isolates

DU-6859, (-)-7-[(7S)-amino-5-azaspiro(2,4)heptan-5-yl]-8-chloro-6- fluoro-1-[(1R,2R)-cis-2-fluoro-1-cyclopropyl]-1,4-dihydro-4-oxoquinol one-3- carboxylic acid, is a new fluoroquinolone with antibacterial activity which is significantly better than those of currently available quinolones. The MICs for 90% of methicillin-susceptible and -resistant Staphylococcus aureus and Staphylococcus epidermidis clinical isolates (MIC90s) were 0.1, 3.13, 0.1, and 0.39 microgram/ml, respectively. MIC50s of DU-6859 against quinolone-resistant, methicillin-resistant S. aureus were 8-, 32-, 64-, and 128-fold lower than those of tosufloxacin and sparfloxacin, ofloxacin and fleroxacin, ciprofloxacin, and lomefloxacin, respectively. DU-6859 inhibited the growth of all strains of Streptococcus pneumoniae and Streptococcus pyogenes at 0.1 and 0.2 microgram/ml, respectively, and was more active against enterococci than the other quinolones tested. Although the activity of DU-6859 against Pseudomonas aeruginosa was roughly comparable to that of ciprofloxacin at the MIC50 level, it was fourfold more active than ciprofloxacin at the MIC90 level. DU-6859 was also more active against other glucose-nonfermenting bacteria, Haemophilus influenzae, Moraxella catarrhalis, and Neisseria gonorrhoeae, than the other drugs tested. Strains of Bacteroides fragilis and Peptostreptococcus spp. were susceptible to DU-6859; MIC90s were 0.39 and 0.2 microgram/ml, respectively. DU-6859 generally showed activities twofold or greater than those of ciprofloxacin and the other drugs against almost all members of the family Enterobacteriaceae. The action of DU-6859 against the clinical isolates was bactericidal at concentrations near the MICs. DU-6859 activity was not affected by different media, pH, inoculum size, or human serum but was decreased in human urine.

The content of urokinase-type plasminogen activator antigen as a prognostic factor in urinary bladder cancer

Urokinase-type plasminogen activator (u-PA) is thought to be implicated in cancer invasion and metastasis. The aim of this study was to determine whether the u-PA content of cancer tissue is a prognostic factor in bladder cancer. Tissue samples from 46 patients with bladder cancer were assessed for u-PA antigen by a highly sensitive enzyme immunoassay. The relationships between the u-PA level in extracts of bladder cancer and the survival rates of the bladder-cancer patients were examined. Patients with a high u-PA level (8 ng/mg of protein and more) showed a statistically significantly higher rate of survival than those with a low u-PA level (p less than 0.005). The u-PA antigen level in cancer tissue was significantly lower in low-graded and non-invasive cancers than in others (p less than 0.01).

Infant schistosomiasis in Ghana: a survey in an irrigation community

We used a rapid, visually read, field applicable monoclonal antibody (MoAb)-dipstick assay for specific diagnosis of urinary schistosomiasis together with microscopy to determine the prevalence of infant schistosomiasis in a community in the Awutu-Efutu Senya District in the Central Region of Ghana. The study group consisted of 97 infants (51 males and 46 females) aged 2 months to 5 years. A total of 75 of 97 (77.3%) subjects submitted stool samples; none had Schistosoma mansoni. Three individuals (3.1%) had hookworms but there were no other intestinal helminths. The urinary schistosomiasis prevalence by MoAb-dipstick (30%) was higher (P < 0.05) than that estimated by microscopy (11.2%). However, three of nine (33.3%) microscopically confirmed cases tested MoAb-dipstick positive after pre-treatment of the urine specimen with heat. The youngest infant to be found infected with S. haematobium microscopically was 4 months old. Fifteen of 71 S. haematobium egg negative individuals tested dipstick positive, giving a dipstick specificity of 78.9% as compared with microscopy as gold standard test. The relative sensitivity of the dipstick was 100%.

Inhibition of development of Kaposi's sarcoma-related lesions by a bacterial cell wall complex

In vitro and in vivo model systems for the study of human immunodeficiency virus (HIV)-associated Kaposi's sarcoma (KS) were used to evaluate compounds for their potential as therapeutic agents. A sulfated polysaccharide-peptidoglycan compound (SP-PG) produced by bacteria controlled the in vitro growth of acquired immunodeficiency syndrome (AIDS)-associated, KS-derived spindle-shaped cells (AIDS-KS cells) at noncytotoxic concentrations. Angiogenesis induced by AIDS-KS cells in the chicken chorioallantoic membrane assay was blocked by SP-PG, which also inhibited the vascular hyperpermeability response and the angiogenesis associated with the induction of KS-like lesions that develop after subcutaneous inoculation of AIDS-KS cells into nude mice. Suramin, pentosan polysulfate, and interferon alpha, which are currently in use for therapy of KS, were either less effective than SP-PG or much more cytotoxic, or both.

Inhibitory effects of quinolones on DNA gyrase of Escherichia coli and topoisomerase II of fetal calf thymus

The in vitro inhibitory effects of quinolones on the bacterial DNA gyrase of Escherichia coli KL-16 and topoisomerase II of fetal calf thymus were compared. All the quinolones tested required higher concentrations to inhibit the topoisomerase II than to inhibit the DNA gyrase, and no correlation existed among their inhibitory activities against both enzymes. However, there was a large difference among the quinolones in their selectivities between the bacterial enzyme and its eucaryotic counterpart. The selectivity of ofloxacin was highest, and the selectivities of CI-934 and nalidixic acid were lowest.

Analysis of base-pairing potentials between 16S rRNA and 5' UTR for translation initiation in various prokaryotes

MOTIVATION

It is well accepted that the 3' end of 16S rRNA is directly involved in prokaryotic translation initiation by pairing with the Shine-Dalgarno (SD) sequence, which is located in the ribosome-binding site of mRNA. According to Shine and Dalgarno, Escherichia coli 's 5' UTR has the pattern of 'AGGAGG' (SD sequence), which is complementary to the 3' end sequence of 16S rRNA. In this work, we systematically calculated free-energy values of the base pairing between the 3' end of 16S rRNA and the 5' UTR of mRNA, in order to analyze the base-pairing potentials in various prokaryotes. The free-energy values were then plotted over distances from the start codon to visualize the free-energy pattern of 5'UTRs.

RESULTS

The average free-energy values fell sharply before the start codon in E. coli, which is consistent with the model that the 3' end of 16S rRNA base pairs with the SD sequence. Haemophilus influenzae, Bacillus subtilis and Helicobacter pylori show a similar pattern, suggesting that the organisms have basically the same mechanism of translation initiation as E. coli. Other eubacteria, such as Synechocystis PCC6803, Mycoplasma genitalium, Mycoplasma pneumoniae and Borrelia burgdorferi also show decreases in their free-energy values, although they are less evident. We also did the same analysis with a eukaryote genome as a control; no fall in free-energy values was observed between the 3' end of 18S rRNA and 5' UTRs of Saccharomyces cerevisiae, suggesting that this organism does not base pair in translation initiation. The three archaebacteria A. fulgidus, M. jannaschii and M. thermoautotrophicum show patterns similar to eubacteria, but not to S. cerevisiae, indicating that archaebacteria are closer to eubacteria than to eukaryotes with respect to the mechanism of translation initiation. From these observations, it appears that the shape of the curve produced by the algorithm can be used to predict the mechanism of translation initiation.

AVAILABILITY

The C programs used in our analysis are available upon request.

Hypouricemic effect of allopurinol and the novel xanthine oxidase inhibitor TEI-6720 in chimpanzees

The hypouricemic effect of a newly synthesized xanthine oxidase/xanthine dehydrogenase inhibitor, TEI-6720, 2-(3-cyano-4-isobutoxyphenyl)-4-methyl-5-thiazolecarboxylic acid, was investigated and compared with that of allopurinol in male chimpanzees (n = 3). When allopurinol (10 mg/kg) was administered orally once a day for three consecutive days, it cumulatively reduced serum urate levels by 29.7, 50.1 and 60.2%, 24, 48 and 72 h, respectively, after the initial dose. This effect was dose dependent at doses of 3 and 10 mg/kg. At 3 mg/kg, the mean serum urate levels were 3.1, 2.4, 2.5 and 2.3 mg/dl before and 24, 48 and 72 h, respectively, after the initial dose. Animals treated with 10 mg/kg of allopurinol showed serum urate levels of 3.3, 2.3, 1.6 and 1.3 mg/dl, respectively. The urate-lowering effect of TEI-6720 was then compared with that of allopurinol at a daily dose of 5 mg/kg (n = 3). Both compounds caused striking reductions in serum and urinary uric acid levels accompanied by an increase in urinary xanthine levels. These effects of TEI-6720 were more potent than those of allopurinol. TEI-6720 reduced serum urate levels by 55.9, 69.6 and 73.6%, 24, 48 and 72 h, respectively, after the first dose, whereas the corresponding values after allopurinol were 28.1, 41.6 and 45.1%. These results suggest that the hypouricemic effect of TEI-6720 may be more potent than that of allopurinol in the treatment of hyperuricemia and gout, and that TEI-6720 may become an effective alternative drug.

Stimulation of nonspecific resistance to infection induced by muramyl dipeptide analogs substituted in the gamma-carboxyl group and evaluation of N alpha-muramyl dipeptide-N epsilon-stearoyllysine

Stimulation of resistance to infection induced by the analogs of muramyl dipeptide (MDP) having substituted functions in the gamma-carboxyl group of D-isoglutamyl residue was examined in experimental Escherichia coli infections in mice. An MDP analog which is an efficient strengthener of resistance to infection, N alpha-MDP-N epsilon-stearoyllysine [MDP-Lys(L18)], was selected through the comparative assessment of a number of compounds in three categories: (i) gamma-alkylamides, (ii) gamma-esters, and (iii) N alpha-MDP-N epsilon-acyllysine derivatives. Furthermore, the antiinfectious activity of MDP-Lys(L18) was evaluated bacteriologically in comparison with that of MDP. The effect of MDP-Lys(L18) on the susceptibility of mice to infections with various species of microorganisms was studied. Protective activity was greatest against E. coli and staphylococcal infections, considerable against Pseudomonas and Candida infections, and least against Klebsiella infection. The effects of bacterial inoculum size and MDP treatment timing, dose, and route of administration on protective activity were studied. The efficacy of MDP-Lys(L18) in protection tests was demonstrated for all administration routes, even the oral. Its high potency was confirmed by the smaller influence of inoculum size and particularly small value of the minimum dosage required for inducing protective activity. A decrease in bacterial survival was observed in the blood and organs of mice treated with the analog and infected with E. coli. The following two useful effects were obtained: the synergistic effect of glycopeptide and chemotherapeutic agents and the stimulation of resistance to infection in animals immunocompromised by cyclophosphamide treatment.