bluuebunny/crossref_metadata_2025 huggingface dataset:
Multicenter prospective randomized trial comparing ceftazidime plus co-trimoxazole with chloramphenicol plus doxycycline and co-trimoxazole for treatment of severe melioidosis
Authors: Sookpranee M , Boonma P , Susaengrat W , Bhuripanyo K , Punyagupta S
Published: June 2012

A prospective randomized trial was conducted at Srinagarind and Khon Kaen hospitals. Ceftazidime (100 mg/kg of body weight per day) and co-trimoxazole (trimethoprim, 8 mg/kg/day; sulfamethoxazole, 40 mg/kg/day) therapy was compared with conventional therapy (chloramphenicol, 100 mg/kg/day; doxycycline, 4 mg/kg/day; trimethoprim, 8 mg/kg/day; sulfamethoxazole, 40 mg/kg/day) in the treatment of 64 patients with bacteriologically confirmed cases of severe melioidosis who were admitted during September 1986 to January 1989. Of 61 evaluable patients (3 were excluded because of severe drug allergies), 42 were septicemic, and 31 of these patients had the most severe form, disseminated septicemic melioidosis. Their cumulative mortalities on day 7 were compared. There were significantly lower overall mortalities from melioidosis, septicemic melioidosis, and disseminated septicemic melioidosis in the group receiving the new treatment compared with those in the group receiving the conventional treatment (47 versus 18.5% [P = 0.039], 57.7 versus 25% [P = 0.039], and 82.3 versus 30.7% [P = 0.006], respectively); but the differences could have been influenced by the greater severity of illness, e.g., shock at initial presentation, in the patients who received the conventional treatment. Among patients with disseminated septicemia and initial shock, there was no significant difference in mortality between the regimens. Both regimens effectively eradicated bacteria from the circulation within 24 h (97 versus 96%, respectively). We recommend ceftazidime and co-trimoxazole as the drugs of choice for treatment of severe melioidosis, especially in those patients with disseminated septicemia.
Specificity of the anticollagenase action of tetracyclines: relevance to their anti-inflammatory potential
Authors: Suomalainen K , Sorsa T , Golub L M , Ramamurthy N , Lee H M , Uitto V J , Saari H , Konttinen Y T
Published: June 2012

The concentrations of doxycycline and 4-de-dimethylaminotetracycline required to inhibit 50% of collagenase activity were found to be 15 to 30 microM for human neutrophil and gingival crevicular fluid collagenases. Fibroblast collagenase was relatively resistant to inhibition by tetracyclines; the 50% inhibitory concentrations of doxycycline and 4-de-dimethylaminotetracycline were 280 and 510 microM, respectively.
Comparison of a polymerase chain reaction assay and a conventional microbiologic method for detection of methicillin-resistant Staphylococcus aureus
Authors: Tokue Y , Shoji S , Satoh K , Watanabe A , Motomiya M
Published: June 2012

The presence or absence of a methicillin resistance gene in 58 clinical isolates of Staphylococcus aureus was examined by the polymerase chain reaction (PCR) and Southern blot analyses. The results were analyzed in relation to those of the MIC assay of methicillin and oxacillin. PCR assay results were identical to those of Southern blot analysis of genomic DNA digested with HindIII (positive, 28 strains; negative, 30 strains). Among the 28 PCR-positive strains, 6 strains showed methicillin susceptibility by the conventional susceptibility test (MICs, less than or equal to 8 micrograms/ml). Culturing of the six strains with ceftizoxime led to an increase in the phenotypic level of resistance to methicillin and oxacillin, indicating that these strains should be classified as methicillin-resistant S. aureus (MRSA). The PCR assay was found to be a sensitive and reliable procedure for the rapid diagnosis of MRSA infection, even in cases in which the conventional MIC assay failed to detect MRSA.
Penetration of cefpodoxime proxetil in lung parenchyma and epithelial lining fluid of noninfected patients
Authors: Muller-Serieys C , Bancal C , Dombret M C , Soler P , Murciano G , Aubier M , Bergogne-Berezin E
Published: June 2012

The pulmonary disposition of cefpodoxime was studied in 12 patients with pulmonary opacities after a single oral dose of 260 mg of cefpodoxime-proxetil, which is equivalent to 200 mg of cefpodoxime. Blood and lung tissue samples were collected during surgery, and bronchoalveolar lavage was carried out 3 h (group A) or 6 h (group B) after drug administration. Urea was used as an endogenous marker for measurement of the volume of epithelial lining fluid (ELF). Concentrations were measured by using a microbiological assay. The mean concentrations of cefpodoxime in plasma, ELF, and lung tissue were, respectively, 1.85 +/- 0.82 mg/liter, 0.22 +/- 0.13 mg/liter, and 0.89 +/- 0.80 mg/kg of body weight in group A and 1.40 +/- 1.25 mg/liter, 0.12 +/- 0.14 mg/liter, and 0.84 +/- 0.61 mg/kg in group B. Concentrations in lung parenchyma 6 h after dosing were at least equal to or above the MICs for 90% of the strains of most organisms commonly found in respiratory tract infections, whereas data for ELF suggest levels of drug insufficient to inhibit bacteria.
Central nervous system targeting of 2',3'-dideoxyinosine via adenosine deaminase-activated 6-halo-dideoxypurine prodrugs
Authors: Morgan M E , Chi S C , Murakami K , Mitsuya H , Anderson B D
Published: June 2012

AIDS dementia complex is a neurologic disorder, characterized by increasingly severe cognitive, behavioral, and motor impairment, which is associated with human immunodeficiency virus (HIV) infection in the central nervous system (CNS). Many of the dideoxynucleosides effective systemically in the treatment of HIV infections, such as 2',3'-dideoxyinosine (ddI), exhibit limited penetration into the CNS and limited or variable effectiveness in reversing the symptoms of AIDS dementia. Thus, approaches for increasing the CNS uptake of ddI and other dideoxynucleosides are needed. The CNS uptake of a series of 6-halo-2',3'-dideoxypurine ribofuranosides (6-halo-ddPs) previously shown to be active against HIV because of their conversion to ddI through the action of adenosine deaminase was examined in rats. In vitro studies in rat blood and brain tissue homogenate suggested a favorable selectivity for bioconversion in brain tissue, but with bioconversion half-lives varying widely within the series. In vivo infusions of 6-chloro-ddP (6-Cl-ddP), 6-bromo-ddP (6-Br-ddP), and 6-iodo-ddP (6-I-ddP) resulted in significant increases (20- to 34-fold) in the ddI concentration ratios in brain parenchyma/plasma when compared with those after an infusion of ddI alone. Absolute concentrations of ddI in brain parenchyma were increased 10- and 4-fold, respectively, following 30-min infusions of 6-Cl-ddP or 6-Br-ddP, but were 2.4-fold lower after an infusion of 6-I-ddP relative to that after a control infusion of ddI. Detailed studies of the plasma pharmacokinetics, CNS uptake kinetics, and bioconversion of 6-Cl-ddP were conducted to compare in vivo transport and bioconversion parameters with those predicted from in vitro measurements and to rationalize the efficiency of CNS delivery of ddI from 6-Cl-ddP. The results show that increased lipophilicity alone does not ensure that a given prodrug will deliver higher levels of a parent compound to the CNS. Both the selectivity and absolute rate of bioconversion in the brain are important factors.
Dehydroepiandrosterone protects mice from endotoxin toxicity and reduces tumor necrosis factor production
Authors: Danenberg H D , Alpert G , Lustig S , Ben-Nathan D
Published: June 2012

Recent reports have demonstrated an immunomodulating activity of dehydroepiandrosterone (DHEA) different from that described for glucocorticoids. The present study was designed to test DHEA's activity in endotoxic shock and to investigate its effect on endotoxin-induced production of tumor necrosis factor (TNF). Mortality of CD-1 mice exposed to a lethal dose of lipopolysaccharide (LPS; 800 micrograms per mouse) was reduced from 95 to 24% by treatment with a single dose of DHEA, given 5 min before LPS. LPS administration resulted in high levels of TNF, a response that was significantly blocked by DHEA, both in vivo and in vitro. DHEA treatment also reduced LPS-induced increments in serum corticosterone levels, a parameter considered not to be mediated by TNF. In another experimental model, mice sensitized with D-galactosamine, followed by administration of recombinant human TNF, were subjected to 89% mortality rate, which was reduced to 55% in DHEA-treated mice. These data show that DHEA protects mice from endotoxin lethality. The protective effect is probably mediated by reduction of TNF production as well as by effecting both TNF-induced and non-TNF-induced phenomena.
Phase I study of antilipopolysaccharide human monoclonal antibody MAB-T88
Authors: Daifuku R , Haenftling K , Young J , Groves E S , Turrell C , Meyers F J
Published: June 2012

Monoclonal antibody MAB-T88 is a human monoclonal immunoglobulin M antibody directed at the lipopolysaccharide of gram-negative bacteria. In this study, nine patients who were expected to become neutropenic from antineoplastic chemotherapy received an infusion of MAB-T88, three patients at each of three doses: 1, 4, and 8 mg/kg of body weight. MAB-T88 was shown to be safe, with an effective half-life in plasma of 25.4 h, and no patient developed immunoglobulin G antibody to MAB-T88.
Iontophoresis generates an antimicrobial effect that remains after iontophoresis ceases
Authors: Davis C P , Wagle N , Anderson M D , Warren M M
Published: June 2012

Iontophoresis required chlorine-containing compounds in the medium for effective microbial population reduction and killing. After iontophoresis ceased, the antimicrobial effect generated by iontophoresis remained but slowly decreased. Antimicrobial effects of iontophoresis may be related to the generation of short-lived chlorine-containing compounds.
Cell type-specific anti-human immunodeficiency virus type 1 activity of the transactivation inhibitor Ro5-3335
Authors: Witvrouw M , Pauwels R , Vandamme A M , Schols D , Reymen D , Yamamoto N , Desmyter J , De Clercq E
Published: June 2012

The drug Ro5-3335 [7-chloro-5-(2-pyrryl)-3H-1,4-benzodiazepin-2(H)-one] inhibits human immunodeficiency virus type 1 (HIV-1) gene expression at the transcriptional level through interference with Tat-mediated transactivation (M.-C. Hsu, A. D. Schutt, M. Holly, L. W. Slice, M. I. Sherman, D. D. Richman, M. J. Potash, and D. J. Volsky, Science 254:1799-1802, 1991). We confirmed this specific inhibitory effect in a quantitative bioassay based on transactivation of a chimeric gene comprising the HIV-1 long terminal repeat promoter fused to the lacZ gene of Escherichia coli and transfected in a HeLa cell line expressing Tat. Ro5-3335 was found to inhibit HIV-1 long terminal repeat-driven lacZ gene expression at a 50% inhibitory concentration of 0.5 microM. The in vitro anti-HIV-1 activity of Ro5-3335 was highly dependent on the nature of the host cells. The highest selectivity index, 50, was found in phytohemagglutinin-stimulated peripheral blood lymphocytes. The selectivity index was between 1 and 10 in the CD4+ T-cell lines CEM, MOLT-4 (clone 8), and HUT-78. In MT-4 and MT-2 cells, Ro5-3335 had no inhibitory effect on HIV-1 replication. The absence of anti-HIV-1 activity of Ro5-3335 in MT-4 cells was confirmed by using different parameters of virus replication and different multiplicities of infection. In persistently HIV-1-infected HUT-78/IIIB/LAI cells, Ro5-3335 failed to demonstrate any activity at subtoxic concentrations. The cytotoxicity of Ro5-3335 was significantly lower in peripheral blood lymphocytes than in the CD4+ T-cell lines.
Pre- and postexposure chemoprophylaxis: evidence that 3'-azido-3'-dideoxythymidine inhibits feline leukemia virus disease by a drug-induced vaccine response
Authors: Mathes L E , Polas P J , Hayes K A , Swenson C L , Johnson S , Kociba G J
Published: June 2012

The benefits of postexposure 3'-azido-3'-dideoxythymidine (AZT) prophylaxis following human immunodeficiency virus exposure are unknown. We describe a comprehensive assessment of pre- and postexposure AZT therapy in the feline leukemia virus (FeLV)-cat model for AIDS which included in vitro testing, an in vivo dose-response titration, a postexposure treatment study, plasma drug concentration determinations, and evaluation of the immune response to FeLV. In in vitro studies, AZT prevented FeLV infection of a feline T-lymphoid cell line, giving 50 and 90% inhibition concentrations of 4.6 and 11.1 mM, respectively. In all of the in vivo efficacy studies, AZT was administered by continuous subcutaneous infusion for 28 days. AZT toxicity was excessive at a dosage of 120 mg/kg of body weight per day, causing acute anemia, but AZT was tolerable at 60 mg/kg/day. In preexposure studies, AZT was efficacious in preventing chronic antigenemia at a dosage of > or = 15 mg/kg/day, at which plasma AZT concentrations averaged between 0.51 and 0.81 micrograms/ml (2.13 and 3.03 microM). As a postexposure treatment, at 60 mg/kg/day, AZT prevented chronic FeLV antigenemia when treatment was started up to 96 h post-virus inoculation (p.i.), but not when treatment was started at 192 h p.i. The 4-day period between 96 and 192 h p.i. appears to be critical for establishing chronic viremia. It is presumed that the increase in virus load between 4 and 8 days p.i. was able to overwhelm the immunologic functions responsible for containment of FeLV infection, even though AZT therapy effectively controlled viremia during the treatment period. The antibody response to FeLV varied depending on the time of AZT treatment initiation relative to virus challenge.When AZT treatment was started 48 h before or 8 h after FeLV challenge, antibodies to FeLV were not detected until after AZT treatment was discontinued at 28 days p.i. Following AZT treatment, however, antibody titers rapidly increased at a rate suggestive of a secondary immune response. When AZT treatment was initiate at later time points relative to virus challenge (24, 48, and 96 h p.i.), antibodies to FeLV became detectable during the treatment period. These results indicate that AZT treatment does not completely prevent FeLV infection, even when treatment begins before virus challenge, and that immune sensitization to FeLV proceeds during the prophylactic drug treatment period.
Mode of antiviral action of penciclovir in MRC-5 cells infected with herpes simplex virus type 1 (HSV-1), HSV-2, and varicella-zoster virus
Authors: Earnshaw D L , Bacon T H , Darlison S J , Edmonds K , Perkins R M , Vere Hodge R A
Published: June 2012

The metabolism and mode of action of penciclovir [9-(4-hydroxy-3-hydroxymethylbut-1-yl)guanine; BRL 39123] were studied and compared with those of acyclovir. In uninfected MRC-5 cells, low concentrations of the triphosphates of penciclovir and acyclovir were occasionally just detectable, the limit of detection being about 1 pmol/10(6) cells. In contrast, in cells infected with either herpes simplex virus type 2 (HSV-2) or varicella-zoster virus (VZV), penciclovir was phosphorylated quickly to give high concentrations of the triphosphate ester. Following the removal of penciclovir from the culture medium, penciclovir-triphosphate remained trapped within the cells for a long time (half-lives, 20 and 7 h in HSV-2- and VZV-infected cells, respectively). In HSV-2-infected cells, acyclovir was phosphorylated to a lesser extent and the half-life of the triphosphate ester was only 1 h. We were unable to detect any phosphates of acyclovir in VZV-infected cells. (S)-Penciclovir-triphosphate inhibited HSV-1 and HSV-2 DNA polymerase competitively with dGTP, the Ki values being 8.5 and 5.8 microM, respectively, whereas for acyclovir-triphosphate, the Ki value was 0.07 microM for the two enzymes. Both compounds had relatively low levels of activity against the cellular DNA polymerase alpha, with Ki values of 175 and 3.8 microM, respectively. (S)-Penciclovir-triphosphate did inhibit DNA synthesis by HSV-2 DNA polymerase with a defined template-primer, although it was not an obligate chain terminator like acyclovir-triphosphate. These results provide a biochemical rationale for the highly selective and effective inhibition of HSV-2 and VZV DNA synthesis by penciclovir and for the greater activity of penciclovir than that of acyclovir when HSV-2-infected cells were treated for a short time.
Effect of sucralfate on pharmacokinetics of fleroxacin in healthy volunteers
Authors: Lubowski T J , Nightingale C H , Sweeney K , Quintiliani R
Published: June 2012

The effect of sucralfate on the pharmacokinetics of fleroxacin was assessed in 20 healthy male volunteers. The study was of a two-way crossover design in which subjects were randomized to one of the following two regimens at the time of entry: (i) a single 400-mg dose of fleroxacin alone or (ii) a 400-mg dose of fleroxacin given once and 1 g of sucralfate given every 6 h starting 24 h before fleroxacin treatment and continuing for 48 h after fleroxacin treatment. Blood samples were collected immediately before fleroxacin administration and at 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 24, 36, and 48 h postdosing. Fleroxacin concentrations in plasma and urine were determined by high-performance liquid chromatography. While concurrent of fleroxacin and sucralfate resulted in a decrease in the area under the plasma concentration-time curve, a decrease in the maximum concentration, and an increase in the time to the maximum concentration (P < 0.05), these changes were modest compared with the interaction of other quinolones with sucralfate. The relative bioavailability of fleroxacin given with sucralfate, calculated from the area under the concentration-time curve, was 76% compared with that of fleroxacin alone. This is significantly better than the bioavailabilities of other quinolones (1.8 to 12.3%) when they are administered with sucralfate.
Piperacillin-tazobactam versus imipenem-cilastatin for treatment of intra-abdominal infections
Authors: Brismar B , Malmborg A S , Tunevall G , Wretlind B , Bergman L , Mentzing L O , Nyström P O , Kihlström E , Bäckstrand B , Skau T
Published: June 2012

In order to compare the clinical and microbiological efficacies and safety of piperacillin plus tazobactam with those of imipenem plus cilastatin, 134 patients with intra-abdominal infections (73 patients with appendicitis) participated in an open randomized comparative multicenter trial. A total of 40 men and 29 women (mean age, 53 years; age range, 18 to 92 years) were enrolled in the piperacillin-tazobactam group and 40 men and 25 women (mean age, 54 years; age range, 16 to 91 years) were enrolled in the imipenem-cilastatin group. The patients received either piperacillin (4 g) and tazobactam (500 mg) every 8 h or imipenem and cilastatin (500 mg each) every 8 h. Both regimens were given by intravenous infusion. A total of 113 patients were clinically evaluable. Of 55 patients who received piperacillin-tazobactam, 50 were clinically cured, while 40 of 58 patients in the imipenem-cilastatin group were clinically cured. The differences were significant (Wilcoxon test; P = 0.005). There were 4 failures or relapses in the piperacillin-tazobactam group and 18 failures or relapses in the imipenem-cilastatin group. The microorganisms isolated were eradicated in similar proportions in the two patient groups. Adverse reactions, mainly gastrointestinal disturbances and nausea, were noted in 13 patients who received piperacillin-tazobactam and in 14 patients who received imipenem-cilastatin. Results of the present study show that piperacillin-tazobactam is effective and safe for the treatment of intra-abdominal infections.
Pharmacokinetics and tissue penetration of a single dose of ceftriaxone (1,000 milligrams intravenously) for antibiotic prophylaxis in thoracic surgery
Authors: Martin C , Ragni J , Lokiec F , Guillen J C , Auge A , Pecking M , Gouin F
Published: June 2012

The pharmacokinetics and tissue penetration of ceftriaxone after a single intravenous injection of 1,000 mg to 17 patients for antibiotic prophylaxis in thoracic surgery were studied. The patients were scheduled for elective noncardiac thoracic surgery. Adequate levels in serum (higher than or equal to the MIC for 90% of isolates of Staphylococcus aureus, Streptococcus spp., Escherichia coli, Haemophilus influenzae, and Klebsiella pneumoniae) were found for all patients throughout the surgical procedures. Mean maximal (5-min) and final (24-h) ceftriaxone levels in serum were 157 +/- 42 and 8.6 +/- 4.5 mg/liter, respectively. The beta-phase elimination half-life was 8.6 +/- 3 h, the plasma clearance was 18.4 +/- 6.25 ml/min, and the apparent volume of distribution at steady state was 0.21 +/- 0.07 liters/kg. At the time of the thoracotomy, the ceftriaxone concentrations were 13.5 +/- 7.8 micrograms/g in thoracic wall fat and 27 +/- 9 micrograms/g in lung tissue. At the time of closure, the ceftriaxone concentration was 15 +/- 9 micrograms/g in thoracic wall fat. During the different steps of the surgical procedures, 100% of patients had adequate levels in tissue (higher than or equal to the MIC for 90% of isolates of Streptococcus spp., E. coli, H. influenzae, and K. pneumoniae). For S. aureus, 90 to 100% of patients had adequate tissue ceftriaxone levels.
Comparison of two antibiotic regimens (piperacillin plus amikacin versus ceftazidime plus amikacin) as empiric therapy for febrile neutropenic patients with cancer
Authors: Feliu J , Artal A , González Barón M , Berrocal A , Chacón I , García de Paredes M L , Espinosa E , Ordóñez A , Zamora P , Montero J M
Published: June 2012

A total of 170 febrile episodes in neutropenic patients with cancer were randomly assigned to be treated with piperacillin-amikacin or ceftazidime-amikacin. The overall response rates were similar in both groups (68 and 65%, respectively). Response rates for clinically or microbiologically documented episodes were 54.5% for piperacillin-amikacin and 58.8% for ceftazidime-amikacin. Response rates for gram-negative bacillary infections were 65 and 73%, respectively. There was also no difference for gram-positive infections (31 and 50%, respectively). The toxicities were also comparable and consisted of skin rashes, hypokalemia, and diarrhea. Vancomycin was added if the fever persisted 72 h after the beginning of therapy; it increased the response rates to 94% when used with piperacillin-amikacin and 92% when used with ceftazidime plus amikacin. Our results suggest that the combinations show similar global efficacies in the treatment of febrile episodes in cancer patients.
Effect of pH on radiometric MICs of clarithromycin against 18 species of mycobacteria
Authors: Rastogi N , Goh K S
Published: June 2012

The antimycobacterial spectrum of clarithromycin, a new macrolide drug, was screened against 26 strains belonging to 18 species of mycobacteria by determining radiometric MICs by Bactec methodology at three different pHs, i.e., pH 6.0, 6.8, and 7.4. The MICs obtained at pH 7.4 were 1 to 2 or more dilutions lower in some of the species than those obtained at pH 6.8, whereas they were significantly higher at pH 6.0. The numbers of species for which MICs were below the Cmax levels of clarithromycin (i.e., 4 micrograms/ml) at different pHs were 8 of 18 species at pH 6.0, 13 of 18 species at pH 6.8, and 14 of 18 species at pH 7.4. The drug possessed promising activity against such potential pathogens as M. avium, M. scrofulaceum, M. szulgai, M. malmoense, M. xenopi, M. marinum, and M. kansasii and rare pathogens like M. chelonei.
Double-blind study comparing erythromycin and mupirocin for treatment of impetigo in children: implications of a high prevalence of erythromycin-resistant Staphylococcus aureus strains
Authors: Dagan R , Bar-David Y
Published: June 2012

Staphylococcus aureus has been consistently isolated from a high proportion of impetiginous lesions, and in several recent studies, it was present in the majority of the cases. Since recently a large proportion of S. aureus strains in our community showed erythromycin resistance, we undertook a prospective double-blind controlled study comparing topical mupirocin with oral erythromycin to determine (i) the prevalence of erythromycin-resistant S. aureus strains in impetigo and (ii) whether an increased rate of failure of erythromycin treatment was associated with such resistance. A total of 102 patients 3 to 185 months old (median = 49 months) were enrolled. Culture was positive for 97 of 102 (95%) patients, and S. aureus was present in 93% of the patients for whom cultures were positive. S. aureus was the single pathogen in 64% of these patients. Erythromycin-resistant S. aureus strains were present in 27 of 91 (28%) patients for whom cultures were positive. In all cases but one, S. aureus was resistant to penicillin, and in all cases it was sensitive to mupirocin. A marked difference was observed in favor of mupirocin in the clinical courses of the disease. However, only patients with erythromycin-resistant S. aureus strains had unfavorable courses compared with those treated with mupirocin (failure rate, 47 versus 2%, respectively). Patients with erythromycin-susceptible S. aureus strains who received erythromycin had a failure rate of 8%. In four patients, S. aureus strains initially susceptible to erythromycin became resistant during treatment. We conclude that erythromycin-resistant S. aureus strains are commonly isolated from impetigo in our region.(ABSTRACT TRUNCATED AT 250 WORDS)
Treatment of Coxsackievirus A9 myocarditis in mice with WIN 54954
Authors: See D M , Tilles J G
Published: June 2012

The therapeutic efficacy of an experimental antiviral agent, WIN 54954, was evaluated in murine myocardial infection with coxsackievirus A9 (CVA9). Eight-month-old male Swiss Webster mice were inoculated with 1.5 x 10(4) PFU of CVA9, Boston strain 13. WIN 54954, a broad-spectrum antipicornavirus agent, was administered orally in a dose of 0.25, 2.5, 25, 50, 100, or 200 mg/kg of body weight per day on days 1 to 3 after virus inoculation. Control animals received xanthan gum carrier only. Mice were sacrificed on day 4. Myocardial titers of virus were determined and found to be significantly lower in the four highest dose treatment groups (P less than 0.001 for all groups) compared with controls. Heart weights were also significantly lower compared with controls in these four groups (P less than 0.001 for all groups). When mice received 50 mg of WIN 54954 per kg daily beginning at either 48 or 72 h postinoculation, myocardial titers were once again significantly reduced compared with those of controls (P less than 0.001 for both groups). Neurological toxicity was observed in the 100- and 200-mg/kg/day groups but not in the lower-dose groups. Thus, WIN 54954 effectively reduced myocardial CVA9 replication in a murine model.
Inhibition of norfloxacin absorption by dairy products
Authors: Kivistö K T , Ojala-Karlsson P , Neuvonen P J
Published: June 2012

Seven healthy subjects received, after an overnight fast, a single 200-mg oral dose of norfloxacin with water, whole milk, and unflavored yoghurt. Coadministration of milk or yoghurt reduced the extent of norfloxacin absorption and the mean peak concentration in plasma by approximately 50%. Taking of norfloxacin with these liquid dairy products should be avoided.
Duration of rifampin chemoprophylaxis for contacts of patients infected with Haemophilus influenzae type B
Authors: Green M , Li K I , Wald E R , Guerra N , Byers C
Published: June 2012

Rifampin is recommended as a prophylactic treatment for intimate contacts of young children who develop invasive infections with Haemophilus influenzae type B (Hib). A 4-day course of rifampin (20 mg/kg of body weight per day, not to exceed 600 mg as a maximum single daily dose) is 95% effective in eradicating pharyngeal colonization with Hib, thus effectively reducing the risk of both associated patients and recurrent illness in index patients less than 2 years old. This study compares rates of eradication of pharyngeal colonization with Hib for 2- and 4-day courses of rifampin therapy. One hundred sixty-three patients with Hib infection were treated at Children's Hospital of Pittsburgh between January 1986 and December 1988; prophylaxis was recommended for 128. Participating families were randomized to receive either 2- or 4-day therapy. Throat swabs were obtained from contacts prior to therapy. Repeat cultures were obtained from colonized contacts 2 days after completing rifampin and again on all contacts 7 to 10 days after completing therapy. Of 68 participating families, 34 received 2-day and 34 received 4-day therapy with rifampin. Twenty-two of 24 colonized contacts in the 2-day group and 17 of 18 in the 4-day group had negative cultures for Hib on follow-up. Two-day therapy with rifampin appears to be as effective as 4-day treatment in the eradication of Hib pharyngeal colonization.
In vitro and in vivo antibacterial activities of a new quinolone, OPC-17116
Authors: Imada T , Miyazaki S , Nishida M , Yamaguchi K , Goto S
Published: June 2012

The in vitro and in vivo antibacterial activities of OPC-17116 were compared with those of ofloxacin, enoxacin, ciprofloxacin, and tosufloxacin. The MICs of OPC-17116 for 90% of the strains tested were 0.125 to 8 micrograms/ml against gram-positive bacteria such as members of the genera Staphylococcus, Streptococcus, and Enterococcus: less than or equal to 0.063 to 16 micrograms/ml against members of the family Enterobacteriaceae; and less than or equal to 0.063 to 16 micrograms/ml against glucose-nonfermentative bacilli such as Pseudomonas aeruginosa. The activity of OPC-17116 against gram-positive organisms was comparable to that of tosufloxacin and higher than those of other reference drugs. The in vitro activity of OPC-17116 against gram-negative bacteria was similar to those of the reference drugs. In experimental systemic infections in mice with various organisms, the efficacy of OPC-17116 was similar to that of tosufloxacin and greater than those of ofloxacin, enoxacin, and ciprofloxacin. In a pyelonephritic model in mice with P. aeruginosa KU-1, OPC-17116 was as active as ciprofloxacin and more active than ofloxacin, enoxacin, and tosufloxacin. In respiratory tract infections in mice with Staphylococcus aureus Smith, Streptococcus pneumoniae TMS 3, and Klebsiella pneumoniae 3K25, the efficacy of OPC-17116 was generally greater than that of tosufloxacin. The peak level of OPC-17116 in the lungs of mice was 10 times higher than that in serum and was significantly greater than levels in lung achieved with an equivalent dose of the other quinolones. The therapeutic efficacy of OPC-17116 may depend not only on its in vitro activity but also on its high concentration in tissue.
Assay of fluconazole by high-performance liquid chromatography with a mixed-phase column
Authors: Wallace J E , Harris S C , Gallegos J , Foulds G , Chen T J , Rinaldi M G
Published: June 2012

A mixed-phase liquid chromatographic column was used to assay fluconazole in plasma, serum, and cerebrospinal fluid. The assay was linear from 0.2 to 20 micrograms/ml, with an average coefficient of variation of less than 5%. The partitioning of the drug between serum and cerebrospinal fluid was determined for 34 patients. The method was demonstrated to be suitable for both pharmacokinetic studies and monitoring of patients receiving treatment with this antifungal agent.
Resistance of Peptostreptococcus spp. to macrolides and lincosamides: inducible and constitutive phenotypes
Authors: Reig M , Moreno A , Baquero F
Published: June 2012

The activities of erythromycin and clindamycin against 350 Peptostreptococcus strains were studied during a 5-year period (1986 to 1991). In 5.1% of the Peptostreptococcus strains, which presented dissociated resistance (clindamycin MIC, less than or equal to 1 microgram/ml; erythromycin MIC, greater than 8 micrograms/ml), evidence of inducible macrolide-lincosamide resistance was shown. A total of 17.7% of the strains presented a constitutive phenotype; the clindamycin and erythromycin MICs for these strains were greater than 8 micrograms/ml.
The lipid A biosynthesis mutation lpxA2 of Escherichia coli results in drastic antibiotic supersusceptibility
Authors: Vuorio R , Vaara M
Published: June 2012

The conditionally lethal lpxA2 mutant of Escherichia coli, which lacks detectable UDP-N-acetylglucosamine acyltransferase activity and which produces greatly reduced amounts of lipid A after a shift to 42 degrees C (S. Galloway and C. R. H. Raetz, J. Biol. Chem. 265:6394-6402, 1990), was found to be, at conditions which promote normal growth, remarkably susceptible to a number of antibiotics. The MICs of hydrophobic antibiotics, such as rifampin, erythromycin, clindamycin, and fusidic acid, were 32- to greater than 128-fold lower for the lpxA2 strain than for the parent type strain, and those of the peptide antibiotics vancomycin and bacitracin were 32- and 256-fold lower, respectively. Futhermore, the lpxA2 strain was found to be sensitive to hypoosmotic conditions. Comparisons with the other characterized outer membrane permeability mutants, such as the heptose-deficient strains of E. coli and Salmonella typhimurium, the acrA and abs mutants of E. coli, and the ssc-1 and class SS-B mutants of S. typhimurium, indicated that the lpxA2 mutant had characteristically the most antibiotic-supersusceptible phenotype. These findings advocate the possible use of the lpxA2 strain as a tool in various fields of basic and applied bacterial research in which the impermeability of the outer membrane currently poses problems.
Emergence and nosocomial transmission of ampicillin-resistant enterococci
Authors: Boyce J M , Opal S M , Potter-Bynoe G , LaForge R G , Zervos M J , Furtado G , Victor G , Medeiros A A
Published: June 2012

Between 1986 and 1988, the incidence of ampicillin-resistant enterococci increased sevenfold at a university-affiliated hospital. Forty-three patients acquired nosocomial infections with ampicillin-resistant enterococci, most of which were also resistant to mezlocillin, piperacillin, and imipenem. An analysis of plasmid and chromosomal DNAs of isolates revealed that the increase was due to an epidemic of 19 nosocomial infections that yielded closely related strains of Enterococcus faecium and to a significant increase in the incidence of nonepidemic, largely unrelated strains of ampicillin-resistant enterococci. The nonepidemic strains were identified as E. faecium, E. raffinosus, E. durans, and E. gallinarum. A logistic regression analysis revealed that patients with nonepidemic resistant strains were 16 times more likely than controls to have received preceding therapy with imipenem. In our institution, the increase in the incidence of ampicillin-resistant enterococci appears to be due to the selection of various strains of resistant enterococci by the use of imipenem and to the nosocomial transmission of E. faecium and E. raffinosus.
Resistance to beta-lactams in Mycobacterium fortuitum
Authors: Fattorini L , Orefici G , Jin S H , Scardaci G , Amicosante G , Franceschini N , Chopra I
Published: June 2012

It is widely assumed that the high level of intrinsic resistance to beta-lactam antibiotics exhibited by mycobacteria results from the combination of factors including permeability to the drugs, beta-lactamase production, and affinity for penicillin-binding proteins (PBPs). We conducted an evaluation of the second and third factors by isolating nitrosoguanidine-induced mutants from the beta-lactamase-producing strain Mycobacterium fortuitum ATCC 19542 that displayed either elevated or reduced resistance to various beta-lactam antibiotics. The mutants studied included D1 (a beta-lactamase producer with high penicillin resistance), gamma 27 (a low-level beta-lactamase producer with low penicillin resistance), and D316 (a high-level beta-lactamase producer with high penicillin resistance). In all strains examined, four major PBPs, named 1, 2a, 2b, and 3, with apparent molecular weights of 102,000, 90,000, 87,000, and 50,000, respectively, were found. The MICs of various beta-lactams toward ATCC 19542 and its mutants were considered in the context of beta-lactamase production, the quantity of PBPs synthesized, and their affinities for beta-lactam antibiotics. The data obtained show that beta-lactamase production is likely to be an important factor in the expression of resistance by clinical isolates and that PBP alterations can contribute to resistance at least in laboratory-derived mutants.
Ofloxacin versus doxycycline for treatment of cervical infection with Chlamydia trachomatis
Authors: Hooton T M , Batteiger B E , Judson F N , Spruance S L , Stamm W E
Published: June 2012

Women with culture-proven Chlamydia trachomatis cervical infection were randomized to receive either ofloxacin (300 mg) or doxycycline (100 mg), orally twice daily for 7 days. All 56 had negative cultures 5 to 9 days after treatment. Four weeks after treatment, 26 (93%) of 28 ofloxacin-treated patients and all 22 doxycycline-treated patients were cured. We conclude that 300 mg of ofloxacin given twice daily for 7 days provides effective therapy for chlamydial infection of the cervix.
Didanosine and zidovudine resistance patterns in clinical isolates of human immunodeficiency virus type 1 as determined by a replication endpoint concentration assay
Authors: McLeod G X , McGrath J M , Ladd E A , Hammer S M
Published: June 2012

Reports of in vitro resistance of human immunodeficiency virus type 1 (HIV-1) to zidovudine (AZT) have raised concerns about the development of resistance to other dideoxynucleosides in clinical use. To address this, we have developed a screening assay which supports the growth of clinical isolates and have applied this to a series of paired isolates from patients entered into a phase I trial of didanosine (DDI). Thirteen patients (10 with AIDS, 3 with AIDS-related complex) who had been exposed to AZT for a mean of 6.5 months (range, 1 to 13 months) were treated with DDI at 750 mg/day. Paired isolates were obtained pretherapy and after a mean of 58 weeks (range, 21 to 90) of DDI therapy by coculture of peripheral blood mononuclear leukocytes (PBLs) with phytohemagglutinin-stimulated donor PBLs. Isolates were passaged only one additional time in PBLs and then tested in parallel in a microtiter assay with phytohemagglutinin-stimulated donor PBLs as targets. PBLs were infected with 10(5) 50% tissue culture infectious doses per 10(7) cells and exposed to DDI (1 to 50 microM) or AZT (0.01 to 100 microM), and supernatants were assayed for the HIV p24 antigen at 7 days postinfection. Control AZT-susceptible and resistant isolates were included. The median pre- and posttherapy DDI susceptibilities of the 13 pairs of isolates were 10.0 microM (range, 1 to 25 microM) and 17.5 microM (range, 2.5 to 50 microM), respectively (P = 0.036; Wilcoxon signed-rank test). These studies thus indicated that (i) the susceptibility to DDI tends to mildly decrease with drug exposure; (ii) the susceptibility to AZT improves with time off AZT; (iii) baseline susceptibilities to DDI have a wide range, and the CD4 response may correlate with the initial susceptibility; and (iv) a PBL-based microtiter assay is useful for screening clinical isolated for dideoxynucleoside susceptibility profiles.
Synergistic activity of azithromycin and pyrimethamine or sulfadiazine in acute experimental toxoplasmosis
Authors: Derouin F , Almadany R , Chau F , Rouveix B , Pocidalo J J
Published: June 2012

The efficacy of azithromycin administered alone or combined with pyrimethamine or sulfadiazine was examined in a murine model of acute toxoplasmosis. Outbred Swiss mice acutely infected with tachyzoites of the virulent RH strain were treated for 10 days from day +1 postinfection. The efficacy of each regimen was assessed in terms of survival rates and sequential titration of parasites in blood, brain, and lungs by using a tissue culture method. Administration of azithromycin at 300, 150, or 75 mg/kg of body weight per day resulted in prolonged survival relative to that of untreated controls; sequential examination of parasite burden showed early eradiaction of Toxoplasma gondii from the lungs, whereas dissemination to the brain was not prevented. A remarkable synergistic effect was observed when azithromycin (150 mg/kg/day) was administered in combination with pyrimethamine or sulfadiazine at noncurative dosages, i.e., 12.5 and 200 mg/kg/day, respectively. In mice treated with azithromycin plus sulfadiazine and azithromycin plus pyrimethamine, parasite burdens in blood and organs, relapses after cessation of therapy, and mortality were all markedly reduced relative to mice treated with any of the agents alone. These results show that azithromycin, which is remarkably active on pulmonary Toxoplasma infection, significantly potentiates the curative effect of sulfadiazine or pyrimethamine.
Absence of "red man syndrome" in patients being treated with vancomycin or high-dose teicoplanin
Authors: Rybak M J , Bailey E M , Warbasse L H
Published: June 2012

Twenty-five febrile patients with a history of intravenous drug use who were receiving either vancomycin (15 patients) or teicoplanin (10 patients) as part of a multicenter, double-blind, randomized, clinical efficacy trial were enrolled, upon receipt of their first dose of antibiotic, into a study to evaluate the effect of 1 g of vancomycin and high-dose teicoplanin (30 mg/kg of body weight) on histamine release and the occurrence of "red man syndrome" (RMS). In addition, 10 healthy volunteer subjects (HVS) were randomized to receive either 1 g of vancomycin intravenously or a saline infusion in a double-blind, crossover design study. Patients and HVS were observed for the presence of erythema, flushing, pruritus, and hypotension during and for up to 1 h postinfusion by a blinded investigator. Histamine concentrations in plasma were measured at baseline and during and after drug infusion. No significant differences were noted in baseline temperature between patients (vancomycin recipients, 102.3 degrees F [39.1 degrees C]; teicoplanin recipients, 102.4 degrees F [39.1 degrees C]) or incidence of bacteremia (7 of 15 vancomycin recipients; 5 of 10 teicoplanin recipients). There were no significant differences in peak vancomycin concentrations in the sera of patients (40.8 micrograms/ml) and HVS (49.9 micrograms/ml). There were no reactions consistent with RMS in any patient who received teicoplanin (0 of 10); there was a significant difference in the occurrence of RMS in patients in comparison with that in HVS (0 of 15 patients, 9 of 10 HVS; P less than 0.001) who received vancomycin. The predominant reaction was erythema and pruritus. Histamine concentrations in plasma and the area under the histamine plasma concentration-time curve were highly variable within groups and were not statistically different between patients and HVS. The incidence of RMS secondary to vancomycin or teicoplanin in our patient population appears to be low and consistent with clinical observations. Similar to previous investigations, RMS secondary to vancomycin in HVS was high (90%). However, we found no relationship between the histamine concentration in plasma or the area under the plasma histamine concentration-time curve and the severity of RMS in HVS. The reason for the discrepancy of RMS in patients versus that in HVS in unknown, but it may be related to a blunted effect of glycopeptides to produce the reaction in the presence of infection or it may be specific to our patient population.
In vitro activity of azithromycin compared with that of erythromycin against Actinobacillus actinomycetemcomitans
Authors: Pajukanta R , Asikainen S , Saarela M , Alaluusua S , Jousimies-Somer H
Published: June 2012

The in vitro susceptibility of Actinobacillus actinomycetemcomitans to azithromycin, a new macrolide antibiotic of a new class known as azalides, was compared with that of erythromycin by the agar dilution method on Mueller-Hinton Haemophilus test medium. Eighty-two A. actinomycetemcomitans strains, 79 recent clinical isolates obtained from 40 periodontally healthy or diseased subjects, and 3 type strains were included in the study. Erythromycin showed poor in vitro activity against A. actinomycetemcomitans. Azithromycin, however, was highly effective against A. actinomycetemcomitans: all strains were inhibited at 2.0 micrograms/ml. Azithromycin exhibited the best in vitro activity against the serotype a subpopulation of A. actinomycetemcomitans: 100% of the strains were inhibited at 1.0 micrograms/ml. The lowest MICs were, however, recorded by serotype b strains. Since azithromycin has favorable pharmacokinetic properties, including excellent distribution into tissues, it could be expected to pass into gingival crevicular fluid at levels sufficient to inhibit A. actinomycetemcomitans in vivo. Therefore, it is a good candidate for future clinical trials in A. actinomycetemcomitans-associated periodontitis.
In vitro and in vivo intraleukocytic accumulation of azithromycin (CP-62, 993) and its influence on ex vivo leukocyte chemiluminescence
Authors: Bonnet M , Van der Auwera P
Published: June 2012

The accumulation of azithromycin in phagocytic cells was studied both in vitro by using a radiolabelled drug and a bioassay and in vivo for 12 volunteers receiving 1.5 g (total dose) orally within 3 days. In vitro, neutrophils and unfractionated blood leukocytes accumulated azithromycin up to 160-fold the extracellular concentration within 1 h at 37 degrees C but less than 3-fold at 4 degrees C. Dead cells accumulated up to 30-fold azithromycin, whereas NaF-treated cells accumulated up to 60-fold arithromycin. The mean efflux from preloaded cells was at most 31.0% +/- 10.6% (standard error of the mean) of the cell-associated concentration within 4 h of incubation at 37 degrees C in drug-free buffer. In vivo, the azithromycin concentration was 45.2 +/- 6.1 mg/liter of intracellular fluid at 2 h after the third dose and 36.6 +/- 8.3 mg/liter at 1 week thereafter. The corresponding concentrations in serum were 0.2 +/- 0.1 (2 h) and less than 0.05 (1 week). The luminol-enhanced chemiluminescence response induced by phorbol myristate acetate, opsonized zymosan, and two opsonized strains of Haemophilus influenzae (a type b capsulated strain and a noncapsulated strain) was also studied ex vivo by using the blood leukocytes from the 12 test volunteers and 4 control volunteers at 2 and 6 h after the third oral dose of azithromycin and at 2, 4, and 7 days thereafter. Azithromycin did not influence this response despite high levels of cellular accumulation.