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Biomedical subjects

P M Furneri

Publications and source records attributed to P M Furneri.

At least 19 recordsLinked to original sources
PubMed2006

Topical kanamycin: an effective therapeutic option in aerobic vaginitis.

Eighty-one patients with clinical diagnosis of aerobic vaginitis (AV) were included in the study. The patients were randomized for treatment, 45 with kanamycin (100 mg vaginal ovules for 6 days, consecutively) and 36 with meclocycline (35 mg vaginal ovules for 6 days, consecutively). The patients were examined before starting the study, 1-2 days after treatment and 30 days after the end of the study. At the first follow-up the patients showed different levels of symptom reduction. Reduction in the presence of leukocytes, vaginal mucosa burning and itching were statistically significant in the group treated with kanamycin with respect to the group treated with meclocycline. Moreover, there was also reduced isolation of Enterobacteriaeae (97%) in the group treated with kanamycin versus those treated with meclocycline (76%). At the second follow-up, vaginal homeostasis (normalization of pH and presence of lactobacilli) was more evident in the kanamycin-treated group. In conclusion, our data suggest that the topical use of kanamycin could be considered a specific antibiotic for the therapy of this new pathology.

Administration, Topical↗
PubMed2001

Two new point mutations at A2062 associated with resistance to 16-membered macrolide antibiotics in mutant strains of Mycoplasma hominis.

We describe two mutants of Mycoplasma hominis PG-21 which show resistance to 16-membered macrolides but susceptibility to lincosamides, obtained by in vitro exposure to increasing doses of josamycin. The 23S rRNA gene showed that each had a mutation (A2062G and A2062T) corresponding to nucleotide 2062 in Escherichia coli, which was associated with the acquired phenotype.

Anti-Bacterial Agents↗
PubMed2001

Novel streptogramin antibiotics.

Streptogramins represent a unique class of antibiotics remarkable for their antibacterial activity and their unique mechanism of action. These antibiotics are produced naturally as secondary metabolites by a number of Streptomyces species and have been classified into two main groups. They consist of at least two structurally unrelated compounds, group A or M (macrolactones) and group B or S (cyclic hexadepsipeptides). Both groups bind bacterial ribosomes and inhibit protein synthesis at the elongation step and they act synergistically in vitro against many microorganisms. Streptogramins A and B act synergistically in vivo; the mixture of the two compounds is more powerful than the individual components and their combined action is irreversible. The pharmacokinetic parameters of group A and B streptogramins in blood are similar. The major gap, limiting the therapeutic use of the natural compounds, was represented by the lack dissolution in water. The synthesis of water-soluble derivatives of pristinamycin I(A) and II(B) has allowed the development of injectable, first represented by quinupristin/dalfopristin (Synercid) and oral formulations, represented by RPR-106972, streptogramins with fixed compositions. Streptogramins have demonstrated activity against Gram-positive microorganisms in vitro and in vivo, including those with multi-drug resistance. Moreover, the absence of cross-resistance to macrolides in many of these microorganisms and the rarity of cross-resistance between the two groups of antibiotics associated with the rapid bacterial killing are the principal features of the streptogramins, offering the possibility for treating the rising number of infections that are caused by multi-resistant Gram-positive bacteria.

Anti-Bacterial Agents↗
PubMed2000

Ofloxacin-loaded liposomes: in vitro activity and drug accumulation in bacteria.

Different ofloxacin-loaded unilamellar vesicles were prepared by the extrusion technique, and their antimicrobial activities were determined in comparison to those of the free drug by means of MIC determinations with both American Type Culture Collection standards and wild-type bacterial strains (six strains of Enterococcus faecalis, seven strains of Escherichia coli, six strains of Staphylococcus aureus, and six strains of Pseudomonas aeruginosa). The accumulation of ofloxacin and liposome-ofloxacin was measured by determining the amount of the drug inside the bacteria as a function of time. Encapsulated fluoroquinolone yielded MICs which were at least twofold lower than those obtained with the free drug. In particular, liposomes made up of dimyristoylphosphatidylcholine-cholesterol-dipalmitoylphosphatidylser ine and dimyristoylphosphatidylcholine-cholesterol-dihexadecylphosphate (4:3:4 molar ratio) provided the best improvement in antimicrobial activity against the various bacterial strains investigated. The liposome formulation produced higher intracellular fluoroquinolone concentrations than those achieved simultaneously with the free drug in both E. coli and P. aeruginosa.

Anti-Infective Agents↗
PubMed1996

Correlation of trimethoprim and brodimoprim physicochemical and lipid membrane interaction properties with their accumulation in human neutrophils.

Dipalmitoylphosphatidylcholine vesicles were used as a biological membrane model to investigate the interaction and the permeation properties of trimethoprim and brodimoprim as a function of drug protonation. The drug-membrane interaction was studied by differential scanning calorimetry. Both drugs interacted with the hydrophilic phospholipid head groups when in a protonated form. An experiment on the permeation of the two drugs through dipalmitoylphosphatidylcholine biomembranes showed higher diffusion rate constants when the two drugs were in the uncharged form; lowering of the pH (formation of protonated species) caused a reduction of permeation. Drug uptake by human neutrophil cells was also investigated. Both drugs may accumulate within neutrophils; however, brodimoprim does so to a greater extent. This accumulation is probably due to a pH gradient driving force, which allows the two drugs to move easily from the extracellular medium (pH approximately 7.3) into the internal cell compartments (acid pH). Once protonated, both drugs are less able to permeate and can be trapped by the neutrophils. This investigation showed the importance of the physicochemical properties of brodimoprim and trimethoprim in determining drug accumulation and membrane permeation pathways.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1995

Pefloxacine mesilate- and ofloxacin-loaded polyethylcyanoacrylate nanoparticles: characterization of the colloidal drug carrier formulation.

The entrapment of fluoroquinolones, perfloxacine mesilate (PFX) and ofloxacin (OFX), in polyalkylcyanoacrylate (PECA) nanoparticles could offer some advantages for their biological application; for examples, increasing their bioavailability, controlling the drug time-release in blood, and reducing the formation of bacterial resistance. To load these two drugs in PECA polymeric bulk, the incorporation or adsorption method was performed. These two methods were capable of influencing nanoparticle size, molecular weight, release profile, and drug-polymer association. The incorporation method, particularly for the OFX system, achieved PECA nanoparticle suspensions with a mean size value three times higher than that obtained in the absence of the drug. In contrast, negligible changes were observed for PFX systems. This preparation process also influenced the nanoparticle storage stability. The molecular weight values of the various nanoparticle preparations were also influenced; that is, the PFX-loaded systems showed an enhancement in the average molecular weight values, whereas a reduction was observed for OFX-loaded systems. The adsorption method showed no particular difference in particle size, molecular weight, and storage stability compared with nanoparticles prepared without the drugs. The nanoparticle loading capacity was higher for the colloidal systems obtained following the incorporation preparation procedure. The release of drug from the nanoparticles was biphasic for both preparation processes. The fluoro-quinolone-loaded nanoparticles showed an enhancement of the antimicrobial activity against standard bacteria strains from 2- to 50-fold compared with the free drugs.

Biological Availability↗
PubMed1995

In-vitro antimycoplasmal activity of flurithromycin.

The in vitro activity of flurithromycin, a 14-membered macrolide drug, was found to be similar to that of erythromycin against 41 strains of Mycoplasma spp. and 100 strains of Ureaplasma urealyticum. All 28 strains of Mycoplasma hominis were uniformly resistant to both macrolides with MICs > 256 mg/L, U. urealyticum showed intermediate resistance with MIC50s of 0.5 and 1 mg/L for erythromycin and flurithromycin, respectively, whereas the ten strains of Mycoplasma pneumonia were susceptible to < or = 0.03 mg/L of both macrolides.

Enterococcus faecalis↗
PubMed1995

Intracellular accumulation of ofloxacin-loaded liposomes in human synovial fibroblasts.

In order to incorporate ofloxacin within liposomes, the reverse-phase evaporation technique was carried out. The liposome lipid matrix consisted of dipalmitoylphosphatidylcholine-cholesterol-dihexadecylphosphate (4: 3:4 molar ratio). The liposome formulation presented a mean size of 185 +/- 31 nm and had an encapsulation capacity of 5.3 microliters/mumol. The liposome formulation was able to deliver ofloxacin into McCoy cells in a greater amount (2.6-fold) than the free drug, improving antibiotic accumulation.

Cells, Cultured↗
PubMed1995

Levels of flurithromycin in female genital tissue.

The levels of flurithromycin in gynecological tissue in 20 female patients were studied after preoperative administration. The tissue flurithromycin levels obtained were comparable to those obtained in serum at 3 and 4 h but were frequently higher than those in serum at 6 and 12 h. Flurithromycin reached the highest concentrations in ovary at 4 h and in endometrium at 6 h.

Anti-Bacterial Agents↗
PubMed1994

Laparoscopy diagnosis of chlamydial salpingitis using a tubal cytobrush.

This is a report of our nontraumatic technique using a tubal cytobrush for epithelial tubal cell recovery during laparoscopy diagnosis of C. trachomatis salpingitis. We performed a three-way laparoscopy in 95 women and inserted a long flexible fallopian tube brush through one of the trocars. This technique showed that it is possible to reach the infection site avoiding vaginal contamination and that sufficient tubal cells can be obtained for isolation of intracellular pathogens. The technique also allowed rapid antigen detection directly on tubal cells by IFA and C. trachomatis isolation on cell culture. Tubal scraping did not cause bleeding or adhesions as later observed in a matched group of women who underwent further laparoscopy during GIFT.

Biopsy↗
PubMed1994

In vitro antimycoplasmal activities of rufloxacin and its metabolite MF 922.

The in vitro activities of rufloxacin and its metabolite, MF 922, were compared with those of ofloxacin, ciprofloxacin, erythromycin, and minocycline against Mycoplasma pneumoniae, Mycoplasma hominis, Mycoplasma fermentans, and Ureaplasma urealyticum. Rufloxacin, MF 922, and ciprofloxacin shared similar activities against all mycoplasmas tested. (MICs for 90% of isolates tested [MIC90s], 0.5 to 4 micrograms/ml. Ofloxacin had the lowest MIC90s for U. urealyticum, M. fermentans, and M. hominis (MIC90s, 0.25 to 1 micrograms/ml) and erythromycin had the lowest MIC90 for M. pneumoniae (MIC90, 0.004 micrograms/ml).

Anti-Infective Agents↗
PubMed1992

In vitro antiviral activity of four isothiazole derivatives against poliovirus type 1.

The in vitro effects of four isothiazoles [5,5'-diphenyl-3,3'-diisothiazole disulfide, 5-phenyl-3-mercapto-isothiazole, 5,5'-(4-chlorophenyl)-3,3'- diisothiazole disulfide, and 5-(4-chlorophenyl)-3-mercapto-isothiazole] on poliovirus type 1 were studied. The derivatives tested demonstrated remarkable viral inhibition, with a higher selectivity index than the previously studied iminodithiole precursors. Under one-step growth conditions, all the isothiazole derivatives caused the greatest activity if added during or after (within 1 h) poliovirus adsorption. These data suggest interference with early events of viral replication. [5-3H]Uridine incorporation into RNA showed that the compounds tested reduced poliovirus RNA synthesis, which was completely shut off after 2 h of incubation and reduced by 50-60% after 4 h. Also, pretreatment of the cell cultures with the compounds for 24 h caused a substantial inhibition of viral replication. The data suggest that the four isothiazole derivatives may have a multi-step antiviral mode of action different from their iminodithiole precursors.

Antiviral Agents↗
PubMed1991

Macrolides: present and future. An appraisal of in-vitro activity and pharmacokinetic behavior.

Macrolides belong to a large family of drugs called macrocyclic antibiotics, that can be divided into four groups: macrolactamas or ansamycins, polyene macrolides, macrolide-like compounds and macrolide antibiotics. Macrolide antibiotics comprise a large group of drugs, which are very much alike, characterized by large lactonic cycle with 12, 14, 15 or 16 atoms, to which are bound sugar and/or aminosugar. Although there are very large structural differences, macrolides represent a homogeneous group of drugs for which both a spectrum and a mode of action are similar. Macrolide antibiotics bind to the large subunit of prokaryotic ribosomes and perturb protein synthesis. The antimicrobial activity of macrolides is broad spectrum, being exhibited against gram-positive and gram-negative bacteria, including actinomyces and mycobacteria, as well as against treponemes, mycoplasmas, chlamydiae, rickettsias and also against some protozoa. Depending on the drug concentrations, bacterial species and phase of growth, macrolides may be bacteriostatic or bactericidal. Macrolides show high tissue/serum rations and greater concentrations of antibiotics are though to be achieved at the presumed site of infection. Such findings are in agreement with the apparent volumes of distribution for all the macrolide drugs, which are generally large. The worldwide resurgence of interest in macrolide antibiotics has yielded several semisynthetic derivatives of 14- and 16-membered macrolides which have progressed to clinical trials.

Anti-Bacterial Agents↗
PubMed1991

Female genital tissue concentrations of roxithromycin.

A new macrolide, roxithromycin, appears to have some interesting pharmacokinetic characteristics dissimilar to those of erythromycin, e.g. it has the unusual property of a long serum half-life and the possibility of once daily dosing. Moreover tissue levels are higher than those obtained with other macrolides, and the drug is still present in the tissues up to 24 h. after dosing. The pharmacokinetics of roxithromycin were studied in 36 women undergoing gynecological surgery, and divided by means of the time of sampling into six different groups. Each group received an initial 300 mg dose followed by 8 successive doses of 150 mg at 12 h intervals. Blood and tissues samples were taken during surgery at 2, 6, 9, 12, 18 and 24 h after the last dose of roxithromycin and the patients were then allocated to one of the six groups by means of the sampling time. Tissue fragments were obtained from ovary, fallopian tubes, endometrium, myometrium, cervix and vagina immediately after the surgical resection of the organs. Tissue and serum concentrations were determined by the microbiological method using Sarcina lutea ATCC 9341; the lowest limit of detection was 0.01 microg/ml or 0.01 microg/g. Roxithromycin reached the highest concentration at the 9th hour after last administration and its tissue levels would encourage a wide use of this drug as a satisfactory alternative to tetracyclines for the therapy of some gynecological infections.

Administration, Oral↗
PubMed1991

In-vitro and in-vivo activity of roxithromycin against Chlamydia trachomatis.

The object of study was the evaluation of both the in-vitro and in-vivo activity of roxithromycin against Chlamydia trachomatis. In-vitro activity against C. trachomatis was achieved by means of minimum inhibitory concentration (MIC) determinations and was recorded as 0.05 mg/l. In vivo activity was tested in 15 of 60 women, attending the Planning Clinic, who were positive for C. trachomatis. Microbiological diagnosis of chlamydial infection was achieved by using a monoclonal direct smear test (Biomerieux-C trachomatis direct IF). All the patients and their partners were treated with 150 mg of roxithromycin twice a day for 15 days. All the patients were requested to avoid unprotected sexual intercourse up to the end of the therapy. The criterion for clinical efficacy was defined as disappearance of clinical signs and the criterion for microbiological efficacy was evidence of eradication of C. trachomatis at the follow-up (mean time: 30 days). A clinical cure and chlamydial eradication was recorded for all the patients at the end of the treatment and at follow-up. Clinical safety was also satisfactory.

Administration, Oral↗
PubMed1991

In vitro activity of flurithromycin against some genital pathogens.

The in vitro antibacterial activity of a new macrolide drug, flurithromycin, was evaluated in comparison with the activity of erythromycin A against some genital pathogens. The strains tested, C. trachomatis, U. urealyticum. M. hominis, N. gonorrhoeae, S. agalactiae and M. genitalium, were both clinically isolates and ATCC standards. The evidenced activity of flurithromycin is similar to that of erythromycin A. Resistances with both macrolides were found in all M. hominis strains and in one strain of U. urealyticum. No particular differences are exhibited between clinical and standard microorganisms.

Bacteria↗