Biomedical subjects

Maria Antonietta Tufano

Publications and source records attributed to Maria Antonietta Tufano.

13 recordsLinked to original sources

PubMed2006

Quinine sulfate inhibits invasion of some bacterial skin pathogens.

BACKGROUND: As some of the many patients who receive antimalarials for the treatment of noninfective inflammatory diseases (lupus erythematosus, collagen vascular diseases, rheumatoid arthritis, and others) are also immunosuppressed because of their disease and/or treatments, and may have concomitant bacterial infections, we investigated the effect of these drugs on the growth and invasion of several bacteria that are commonly associated with skin and soft tissue infections to determine whether they could protect against such conditions and obviate the need for an additional antibiotic drug. METHODS: The effect of quinine sulfate (QS) at concentrations of 50 and 100 microm on the entry process of Enterobacter agglomerans, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae into Caco-2 cells was studied during the infection period. The invasive efficiency was expressed as the number of viable internalized bacteria obtained by counting the colony-forming units (CFUs). RESULTS: The invasive ability of E. agglomerans and S. aureus was significantly inhibited by 50 and 100 microm QS in a dose-dependent manner when the drug was added to Caco-2 cell monolayers during the infection period; however, QS had no significant effect on the internalization of P. aeruginosa or K. pneumoniae. DISCUSSION AND CONCLUSIONS: Antimalarial drugs are currently widely used to treat patients with autoimmune dermatologic and rheumatologic diseases, and have also been recently proposed as additional therapy for patients with human immunodeficiency virus (HIV) infection. These patients, who are often immunocompromised, may receive a secondary advantage from these antimalarials, which may provide some protection against staphylococci (amongst the most important human pathogens causing many superficial and systemic infections) and E. agglomerans.

Adenocarcinoma↗

PubMed2005

Toll-like receptor 2 (TLR2) mediates intracellular signalling in human keratinocytes in response to Malassezia furfur.

Toll-like receptors (TLRs) are crucial players in the innate immune response to microbial invaders. The lipophilic yeast Malassezia furfur has been implicated in the triggering of scalp lesions in psoriasis. The aim of the present study was to assess the role of TLRs in the defence against M. furfur infection. The expression of the myeloid differentiation factor 88 (MyD88) gene, which is involved in the signalling pathway of many TLRs, was also analysed. In addition, a possible correlation of antimicrobial peptides of the beta-defensin family to TLRs was tested. Human keratinocytes infected with M. furfur and a variety of M. furfur-positive psoriatic skin biopsies were analysed by RT-PCR, for TLRs, MyD88, human beta-defensin 2 (HBD-2), HBD-3 and interleukin-8 (IL-8) mRNA expression. When keratinocytes were infected with M. furfur, an up-regulation for TLR2, MyD88, HBD-2, HBD-3 and IL-8 mRNA was demonstrated, compared to the untreated cells. The same results were obtained when psoriatic skin biopsies were analysed. The M. furfur-induced increase in HBD-2 and IL-8 gene expression is inhibited by anti-TLR2 neutralising antibodies, suggesting that TLR2 is involved in the M. furfur-induced expression of these molecules. These findings suggest the importance of TLRs in skin protection against fungi and the importance of keratinocytes as a component of innate immunity.

Adaptor Proteins, Signal Transducing↗

PubMed2005

Hydroxytyrosol, a natural antioxidant from olive oil, prevents protein damage induced by long-wave ultraviolet radiation in melanoma cells.

Previous studies showed that long-wave ultraviolet (UVA) radiation induces severe skin damage through the generation of reactive oxygen species and the depletion of endogenous antioxidant systems. Recent results from our laboratory indicate a dramatic increase of both lipid peroxidation products (TBARS) and abnormal L-isoaspartyl residues, marker of protein damage, in UVA-irradiated human melanoma cells. In this study, the effects of hydroxytyrosol (DOPET), the major antioxidant compound present in olive oil, on UVA-induced cell damages, have been investigated, using a human melanoma cell line (M14) as a model system. In UVA-irradiated M14 cells, a protective effect of DOPET in preventing the uprise of typical markers of oxidative stress, such as TBARS and 2'7'-dichlorofluorescein (DCF) fluorescence intensity, was observed. In addition, DOPET prevents the increase of altered L-isoAsp residues induced by UVA irradiation. These protective effects are dose dependent, reaching the maximum at 400 microM DOPET. At higher concentrations, DOPET causes an arrest of M14 cell proliferation and acts as a proapoptotic stimulus by activating caspase-3 activity. In the investigated model system, DOPET is quantitatively converted into its methylated derivative, endowed with a radical scavenging ability comparable to that of its parent compound. These findings are in line with the hypothesis that the oxidative stress plays a major role in mediating the UVA-induced protein damage. Results suggest that DOPET may exerts differential effects on melanoma cells according to the dose employed and this must always be taken into account when olive oil-derived large consumer products, including cosmetics and functional foods, are employed.

Antioxidants↗

PubMed2005

Pharmacodynamics of levofloxacin in patients with acute exacerbation of chronic bronchitis.

STUDY OBJECTIVES: Levofloxacin is a fluoroquinolone antimicrobial agent for which pharmacodynamic relationships between the maximum serum antibiotic concentration (Cmax)/minimum inhibitory concentration (MIC) ratio and/or the area under the serum concentration-time curve during a 24-h dosing period (AUC(0-24))/MIC ratio and clinical and/or microbiological outcomes have been developed. In this study we examined the relationship between the in vitro bacterial susceptibility to levofloxacin, the achieved levofloxacin serum and sputum concentrations, and the in vivo bacterial eradication in patients with acute exacerbations of chronic bronchitis. PATIENTS AND INTERVENTIONS: Thirty patients received levofloxacin, 500 mg/d po for 7 days. Samples of venous blood and sputum for the determination of levofloxacin concentrations were collected on day 1 immediately prior to dosing, and then at 1, 4, 8, 12, and 24 h. RESULTS: The mean peak concentration in serum (6.5 mg/L) was found 1 h after administration, and at 4 h after administration in sputum (5.1 mg/L). Levofloxacin was always detectable 24 h after administration from both samples. Successful treatment occurred in 90% (27 of 30 patients) when assessed both clinically and bacteriologically. Treatment was successful in eight patients when the AUC(0-24)/MIC ratio was > 40 for serum, and in nine patients when it was > 30 for sputum. Treatment was also successful in seven patients when the Cmax/MIC ratio was > 5.01 for serum, and in nine patients when the Cmax/MIC ratio was > 4.01 for sputum. Treatment was successful in 90% (27 of 30 patients) when the AUC(0-24)/MIC ratio was > 125 for serum and > 100 for sputum, and when Cmax/MIC was > 10.01 for serum and > 8.01 for sputum following the first dose. CONCLUSIONS: The pharmacodynamics values that we have obtained in sputum with levofloxacin may be used as predictors of therapy outcomes.

Acute Disease↗

PubMed2005

Ectoine from halophilic microorganisms induces the expression of hsp70 and hsp70B' in human keratinocytes modulating the proinflammatory response.

The heat shock proteins (Hsps) have an important role in the cytoprotection and repair of cells and tissues. One potential mechanism of protection is the ability of Hsp to inhibit genetic expression of proinflammatory cytokines, the transcription of which is dependent on nuclear factor-kappa B (NF-kappaB) activation. In this study, we evaluated the ability of ectoine, a novel natural biomolecule produced by halophilic microorganisms, to activate the hsp70 and hsp70B'. By reverse transcriptase-polymerase chain reaction and Western blot analysis, we demonstrated increased hsp70B' gene expression in human keratinocytes treated with ectoine and heat stressed. In contrast, in the absence of heat shock, ectoine was unable to induce hsp70B' but had the ability to induce another member of the Hsp family, the hsp70. The latter is not only elevated in response to stress but is also present at basal level in unstressed cells. In addition, ectoine had no effect on proinflammatory cytokines interleukin (IL)-1alpha, IL-6, IL-8, and tumor necrosis factor-alpha and on NF-kappaB and IkappaB-alpha pathway, whereas it downregulated the expression of cited proinflammatory cytokines, in lipopolysaccharides-treated keratinocytes. These results highlighted the ability of ectoine to protect cells from stress conditions and to prevent cell damage by maintaining an elevated level of the Hsp70. Overall, these data might suggest the use of this compatible solute in cosmetic and even pharmaceutical preparations aiming to activate a cytoprotective heat shock response in human cells.

Amino Acids, Diamino↗

PubMed2004

Malassezia furfur induces the expression of beta-defensin-2 in human keratinocytes in a protein kinase C-dependent manner.

Antimicrobial peptides of the beta-defensin family are expressed in all human epithelial tissues tested to date and have recently been the subject of vigorous investigation. Their localization and characteristics support the hypothesis that these peptides play a role in mucosal and skin defense. The lipophilic yeast Malassezia furfur is a saprophyte found in normal human cutaneous flora. Malassezia furfur is not only a saprophyte, but is also associated with several diseases such as Malassezia folliculitis, seborrheic dermatitis and some forms of atopic dermatitis, psoriasis and confluent and reticulate papillomatosis. Little is known about the mechanism by which M. furfur overcomes the natural barrier of the skin. To further define the role of the beta-defensins in the innate human skin immune response, we analyzed the mRNA expression of two human beta-defensins HBD-1 and HBD-2 in human keratinocytes treated with M. furfur. In addition, we looked into how M. furfur of TGF-beta1 and IL-10, cytokines that interfere with the development of protective cell immunity, regulate their expression. Finally, we examined the signal transduction mechanisms involved during M. furfur uptake. Cultured human keratinocytes were treated with M. furfur. The mRNA and protein expression were analyzed, respectively, by reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting. Our data demonstrate that M. furfur does not modify HBD-1 expression, whereas it up-regulates, via protein kinase C (PKC), the expression of HBD-2, TGFbeta-1 and IL-10 48 h after treatment. Our results suggest that beta-defensins are integral components of innate host defenses. They play an essential part in the resistance of the human skin surfaces against M. furfur uptake and other microbial invasion.

Cell Division↗

PubMed2004

Possible role of Malassezia furfur in psoriasis: modulation of TGF-beta1, integrin, and HSP70 expression in human keratinocytes and in the skin of psoriasis-affected patients.

BACKGROUND: Psoriasis is a disease characterized by an abnormal pattern of keratinocyte growth and differentiation. Malassezia furfur forms part of the normal human skin flora. It may also be involved in the pathogenesis of psoriasis. To define the role of M. furfur in the pathogenesis of psoriasis, we investigated how M. furfur regulates molecules involved in cell migration and proliferation. The experiments were performed using human keratinocytes and skin biopsies from M. furfur-positive and -negative psoriasis-affected patients. In addition, we examined the signal transduction mechanisms involved. MATERIALS AND METHODS: Western blot analysis was performed on human keratinocytes lysates treated or untreated with M. furfur and on biopsies from healthy and psoriasis patients. Signal transduction mechanisms involved were evaluated by electrophoretic mobility shift assay using the AP-1 inhibitor curcumin. RESULTS: We found that M. furfur up-regulates transforming growth factor-beta1 (TGF-beta1), integrin chain, and HSP70 expression in human keratinocytes via AP-1-dependent mechanism. In the biopsies of M. furfur-positive psoriasis-affected patients, an increase in TGF-beta1, integrin chains, and HSP70 expression was found. CONCLUSION: Our data suggest that M. furfur can induce the overproduction of molecules involved in cell migration and hyperproliferation, thereby favoring the exacerbation of psoriasis.

Blotting, Western↗

PubMed2004

Alpha-MSH reduces the internalization of Staphylococcus aureus and down-regulates HSP 70, integrins and cytokine expression in human keratinocyte cell lines.

Alpha-melanocyte-stimulating hormone (alpha-MSH) is a neuropeptide predominantly produced by the pituitary gland, but it is also generated by many extra-pituitary cells including keratinocytes of the skin. This neuropeptide has anti-inflammatory and antimicrobial effects and probably contributes in innate immunity. Staphylococcus aureus is the aetiological agent of a wide range of infections in humans. Colonization of human skin by S. aureus is a characteristic feature of several skin diseases and is often followed by tissue invasion and severe cell damage. The aim of our study was to detect a possible role of alpha-MSH during the early infection stages in the adhesion and penetration of keratinocytes before cell damage. Our data demonstrated that alpha-MSH precociously down-regulates the production of integrins such as beta1 and heat shock surface protein 70, essential molecules for the entry of S. aureus. Moreover, in our experimental model, alpha-MSH induces the down-regulation of the pro-inflammatory cytokine expression and of the adhesion molecules in keratinocytes activated by S. aureus. Our data suggest that alpha-MSH plays a protective role in the skin by reducing infection and the inflammatory process.

Blotting, Western↗

PubMed2003

Bacterial components induce cytokine and intercellular adhesion molecules-1 and activate transcription factors in dermal fibroblasts.

This study investigated the effect of various structural components of Gram-positive (lipotheichoic acid and protein A) and Gram-negative (porins and lipopolysaccharide) bacteria on human dermal fibroblasts. Fibroblasts are important effector cells which have a potential role in augmenting the inflammatory response in various diseases. In this study we present a profile of TNF-alpha, IL-6 and IL-8, the expression of intercellular adhesion molecules (ICAM-1) and the activation of transcriptional nuclear factor NF-kB and AP-1 in human dermal fibroblasts stimulated by bacterial surface components. Compared to the controls, increased ICAM-1, IL-6 and IL-8 gene expression after stimulation of LPS and porins at 2 and 4 h was more evident than that obtained following stimulation of LTA and PA. Gene expression was also associated with the production of cytokine proteins in culture supernatants. TNF-alpha gene expression remained undetectable. Moreover, LPS and porin treatments determined IkBalpha phosphorylation and degradation in human dermal fibroblasts and the subsequent activation of nuclear factors NF-kB and AP-1. These data suggest the importance of such stimuli in the first step of the inflammatory process, as well as the important role played by fibroblasts in skin inflammatory disease.

Adult↗

PubMed2003

Quinine sulfate and HSV replication.

Although antimalarial drugs have been developed primarily to treat malaria, they are also beneficial for many dermatological, immunological, and rheumatological diseases, for which they are mostly used today in the Western world. The aim of the present study was to investigate the effect of quinine sulfate (QS) on the multiplication and adsorption of herpes virus type I (HSV-1). When Vero cells (African green monkey kidney) are infected with HSV-1 in the presence of QS, the viral adsorption is reduced, as demonstrated by a decrease of the number of microscopic plaques of the virus. When the virus-infected Vero cells are incubated in the presence of QS, the multiplication of HSV-1 is also reduced, and the diameter of the plaque are visibly smaller. The practical implications of the antiviral action of antimalarial drugs might be especially important to immunosuppressed patients who receive these drugs for autoimmune collagen-vascular diseases or as additional therapy for AIDS.

Animals↗

PubMed2003

Pretreatment antimicrobial susceptibility testing is cost saving in the eradication of Helicobacter pylori.

BACKGROUND & AIMS: The major obstacle to 100% effective eradication of Helicobacter pylori infection is represented by antimicrobial-resistant H. pylori strains. This randomized study was designed to evaluate whether regimens based on pretreatment susceptibility testing were more effective and cost saving compared with standard nonsusceptibility testing-based therapy in the eradication of H. pylori infection. METHODS: We studied 150 consecutive H. pylori-infected dyspeptic subjects. Patients were randomly assigned to omeprazole 20 mg twice daily, clarithromycin 500 mg twice daily, and metronidazole 500 mg twice daily for 7 days or to omeprazole 20 mg twice daily and 2 antimicrobials chosen based on susceptibility testing. H. pylori status was reevaluated 12 weeks after the end of treatment by the (13)C-urea breath test. RESULTS: Susceptibility testing-based regimens led to the following results. (1) Eradication rates were 97.3% (95% confidence interval [CI], 91.2%-99.5%) (71 of 73) and 94.6% (95% CI, 87.6%-98.3%) (71 of 75) in the per-protocol and intention-to-treat analysis, respectively. These were significantly higher (P < 0.005) than eradication rates obtained without susceptibility testing, that is, 79.4% (95% CI, 69.1%-87.6%) (58 of 73) and 77.3% (95% CI, 66.9%-85.7%) (58 of 75) in the per-protocol and intention-to-treat analyses, respectively. (2) There were savings of approximately $5 U.S. per patient compared with standard triple therapy. CONCLUSIONS: Pretreatment antimicrobial susceptibility testing is more effective and cost saving and, in health systems that confirm cost advantage, microbial susceptibility testing should be routinely used for eradication of H. pylori infection.

Adult↗

PubMed2002

Quinine sulfate and bacterial invasion.

BACKGROUND: As many patients who receive antimalarial drugs for treatment of noninfectious, inflammatory diseases are also immunosuppressed and might have a concomitant bacterial infection, we studied the effectiveness of these drugs against bacterial infections, to find out whether they could protect against (and even treat) such conditions and obviate the need for an additional antibiotic drug. METHODS: Effect of QS on bacterial growth: Escherichia coli (E. coli) HB101 pRI203 were cultured overnight at 37 degrees C in TSB and inoculated (approx 1 x 10(7) cells/ml) in MEM in the presence of QS at various concentrations (0, 50 and 100 microM).The effect of QS at concentration of 50 and 100 microM on the entry process of E. coli HB101 pRI203 into HeLa cells was studied under different experimental conditions: 1. QS was incubated with 3 x 10(5) HeLa cells for 60 min at 37 degrees C prior to infection. 2. QS was added to HeLa cell monolayers during the infection period. RESULTS: QS showed no antibacterial activity after 24 h of incubation. The invasive efficiency of the bacteria was significantly inhibited at a dose-dependent manner, when QS was added to HeLa cells for 60 min at 37 degrees C prior to infection (condition 1), and to a lesser extent when added during the period of infection (condition 2). CONCLUSIONS: Although the antimalarials are generally regarded as being inactive against most extracellular bacterial species, our results indicate that QS significantly inhibited the internalization/invasion efficacy of E. coli in the host cells.

Journal Article↗

PubMedDate not supplied

Quinine sulfate inhibits invasion of Salmonella typhimurium and Shigella flexneri: a preliminary study.

BACKGROUND: The incidence of typhoid fever and shigellosis parallels that of malaria, so many individuals who are on antimalarial drugs can be found in areas where these diseases are widespread. We investigated the effect of quinine sulfate on the growth and invasion of Salmonella typhimurium and Shigella flexneri M90T to determine whether people on antimalarials can have secondary gain from some protection against typhoid fever and shigellosis. METHODS: The effect of 50 and 100 microM quinine sulfate on the invasive ability of Salmonella typhimurium and Shigella flexneri M90T into human colon adenocarcinoma-2 (Caco-2) cells was studied during the infection period. The invasive efficiency was expressed as the number of viable internalized bacteria by counting the colony-forming units. RESULTS: The invasive ability of Salmonella typhimurium and Shigella flexneri M90T was significantly inhibited by 50 and 100 microM quinine sulfate in a dose-dependent manner (for Salmonella typhimurium) when the drug was added to Caco-2 cell monolayers during the infection period. CONCLUSIONS: Since so many people who are on antimalarial drugs visit and inhabit areas that are endemic to typhoid fever and Shigella infection, a study on the influence of these drugs on the disease is long overdue. Our data indicate that quinine sulfate interferes with the invasion and internalization of Salmonella typhimurium and Shigella flexneri M90T into host cells. Further studies on additional strains/serotypes with other newer antimalarials at various concentrations are needed to verify this effect of quinine sulfate and to draw conclusions on its significance in vivo.

Antimalarials↗