M Covi

Università degli Studi di Modena e Reggio Emilia, Modène, Emilia-Romagna, Italy

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Publications (16)22.27 Total impact

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    ABSTRACT: Compelling evidence suggests that co-trimoxazole prophylaxis reduces mortality in HIV-infected patients, although it is unclear whether these effects are directly related to antimicrobial activities. We evaluated in vitro phagocytosis and killing of Staphylococcus aureus in alveolar macrophages (AM) obtained from AIDS patients who smoke, treated (n=19) or not treated (n=13) with co-trimoxazole, as compared to non-HIV-infected healthy smokers (n=15). Phagocytosis and killing of Staphylococcus aureus by AM obtained from non-co-trimoxazole treated AIDS patients were significantly lower compared to non-HIV-infected healthy smokers. In contrast, AIDS patients treated with co-trimoxazole prophylaxis showed phagocytosis and killing levels similar to those of healthy controls. These results might help to clarify the observed positive effect of co-trimoxazole on survival in HIV-infected patients.
    No preview · Article · Jul 2011 · Journal of biological regulators and homeostatic agents
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    ABSTRACT: Multidrug-resistant (MDR) tuberculosis (TB) is a form of TB that is resistant to some of the first-line drugs used for the treatment of the disease. It is associated both with a higher incidence of treatment failures and of disease recurrence, as well as with higher mortality than forms of TB sensitive to first-line drugs. Levofloxacin (LFX) represents one of the few second-line drugs recently introduced in the therapeutic regimens for MDR TB. We report our experience concerning in vitro activity and clinical safety of LFX in long term second-line regimens for MDR TB. IN VITRO ACTIVITY ON MYCOBACTERIA: The in vitro activity of ciprofloxacin, ofloxacin and LFX was studied on 28 strains belonging to different species of Mycobacteria. In Dubos medium, LFX inhibited the growth of both library and MDR clinical Mycobacteria strains in a range of 0.25-1 mcg/ml. In International Union Tuberculosis Medium (IUTM) the minimum inhibitory concentrations (MIC) were slightly higher, but LFX activity was not affected by the higher complexity of the medium. CLINICAL EXPERIENCE: Four patients with MDR TB were treated with a second-line regimen comprising oral LFX 500 mg twice daily, for at least 9 months. Two isolates obtained from the patients reported here showed multi resistance to isoniazid and rifampin, one to rifampin and streptomycin and one to isoniazid and ethambutol. During therapy, no significant alteration of either liver function tests, blood tests or any other described side effect of the fluoroquinolone class was observed. The 3 patients with pulmonary MDR TB showed radiologic and clinical improvement. CONCLUSION: We confirm the higher in vitro activity of LFX compared to older fluoroquinolones. Furthermore, in a limited number of MDR TB patients, second-line regimens comprising LFX 500 mg b.i.d. administered in a range of 9-24 months were well tolerated and safe.
    Full-text · Article · Mar 2002 · Monaldi archives for chest disease = Archivio Monaldi per le malattie del torace / Fondazione clinica del lavoro, IRCCS [and] Istituto di clinica tisiologica e malattie apparato respiratorio, Università di Napoli, Secondo ateneo
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    ABSTRACT: Purpose: The aim of this study was to evaluate the AM, obtained bronchoalveolar lavage, Ph, iK and (O2-) release in 7 patients suffering from systemic sclerosis (SSc) with secondary pulmonary fibrosis. SSc etiology is unknown, but AMs could play a key role in the pathogenesis of the disease, when located in the lung. Methods: We measured O2- release by AM, expressed in nmol/1x106/ min, by means of the spectrophotometric method based on cytocrome c reduction,first in resting conditions and after stimulation with zimosan, using a wave length of 468-550 nm. Ph and iK were performed by incubating the AMs with a Staphylococcus aureus ATCC 6538 suspension (AM:Staph about 1:10) for 30'. The cells were then lysed by suitably diluted H2O and seeded on Brain Heart Infusion Agar plates; the colonies were counted after 18-24 hour incubation at 37°C. Results: The SSc AM Ph and iK gave significantly lower results;O2- release was higher than the controls in basal conditions, but not after stimulation by zimosan as shown in the table below. Conclusions: We do not know the causes of the impaired Ph and iK and of the excessive AM O2- release, but these changes could play an important role in the SSc lung damage. Clinical Implications: The most important SSc treatment is based on immunosuppressors and corticosteroids; our data, however, also demonstrates that antioxidant and "immunomodulant therapies" could be useful in SSc. Contr. SSc p Ph % 31.2 ± 4.5 14.9 ± 6.0 < 0.001 iK% 26.0 ± 5.7 11.1 ± 6.0 < 0.001 Basal O2- 0.44 ± 0.1 0.8 ± 0.06 < 0.001 Stim. O2- 1.60 ± 0.5 2.5 ± 1.2 NS.
    No preview · Article · Oct 1998
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    ABSTRACT: We carried out broncho-alveolar lavage in 32 patients suffering from some interstitial lung diseases. The obtained alveolar macrophages (AMs) were challenged with an 18 hour colture in Brain Heart Infusion Broth of Staphylococcus Aureus ATCC 6538 to evaluate phagocytosis and intracellular killing. The bacteria were put in contact with an AM suspension at the 10:1 ratio for 30′ to permit phagocytosis and killing. Then we added staphylolisin to destroy only the non phagocyted staphytococci. Instead the phagocyted ones, released by treating AMs by ipotonic solution, were seeded into Brain Heart Infusion Agar plates, at 37°C for 18-24 hours [Velluti G. et al. J Chemother, 1991; suppl.4: 527-529]. By colony's count we evaluated the phagocyted and the killed germs. As we can see in the table we found a significant reduction of both AM activities in the studied pathologies. # PHAGOCYTOSIS KILLING p vs % % controls CONTROLS 15 31.2 ± 4.5 26.0 ± 5.7 - IPF** 12 19.9 ± 3.3 14.6 ± 5.0 < 0.001 AIDS* 13 14.3 ± 5.2 9.70 ± 5.4 < 0.001 ACUTE EAA○ 7 18.3 ± 8.2 14.2 ± 7.5 < 0.001 ** Idiopathic Pulmonary Fibrosis; *Acquired Immunodeficiency Syndrome; ○Acute Extrinsic Allergic Alveolitis To phagocytosis can follow the killing of the bacteria and the processed antigen presentation to the CD4 lymphocytes. Therefore the reduction of these activities in the studied diseases, can involve a lower resistance to infections and an altered cellulo-mediated response. However it's unclear whether the observed alterations are the cause or the consequence of these pathologies; moreover we don't know the importance of the lymphocyte influence in these AM activities.
    No preview · Article · Dec 1997
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    ABSTRACT: Introduction. The macrolide antibiotics hold an extremely important place in the therapy of respiratory infections. Rokitamycin is a new semisynthetic macrolide with 16 carbon atom lactone ring. The molecule's marked lipophilicity, exceptional capacity for intracellular penetration and enhanced affinity for bacterial ribosomes (subunit 50S) ensure its bactericidal activity at concentrations close to the MIC. This study was designed to verify the therapeutic efficacy and safety of rokitamycin in the treatment of acute respiratory infections in adults. Materials and methods. Patients of either sex, aged over 18 years, with acute respiratory infections and body temperature ≥38°C, were admitted to this open trial. The trial was conducted in accordance with the principles of the Declaration of Helsinki and amendments, each patient giving informed consent to take part. Patients were treated with rokitamycin (400 mg tablets) 800 mg/day orally for 14 days. Results. Sixty patients entered the study (50 males, 10 females), mean (±SD) age 61.5± 12.8 years (range 31-85), mean weight 70.2±12.0 kg (range 45-102); 24 were in an acute exacerbation of chronic bronchitis, 16 had COPD, 14 acute bronchitis, 4 pneumonia, and 2 bronchopneumonia. All symptoms gradually improved during treatment. After only three days hemoptysis was no longer recorded and body temperature had returned to normal. Sputum was absent or less than 10 mL/day in 96.8% of cases by the end of treatment, and was serous in 82.8%. Chest pain was mild or nil in all patients and dyspnea disappeared in 65-3%, rales in 96% and wheeze in 92%. Coughing was considerably reduced (49.7%). The 51 microorganisms isolated at the outset were completely eradicated (Gram-negative: 41 H. influenzae, 1 Kl. pneumoniae; Gram-positive: 3 Strept. pneumoniae, 2 Strept. spp and 4 unclassified). Reinfection were observed in two cases (1 Enterobacter and 1 H. parainfluenzae). All patients tolerated the drug well. Discussion. The findings on this trial confirm the therapeutic efficacy and safety of rokitamycin in acute respiratory infections, its spectrum of action comprising the pathogens most frequently isolated in these infections. By the end of treatment all the microorganisms isolated at the start had been eradicated. The results therefore fully confirm the findings of earlier investigations.
    No preview · Article · Sep 1996 · Minerva pneumologica

  • No preview · Article · Oct 1995 · Tubercle and Lung Disease
  • M Covi · G Velluti
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    ABSTRACT: In a prospective multicentre open trial, hospitalised adult patients with acute lower respiratory tract infections, mainly pneumonia or bronchitis, were randomised to receive either isepamicin 8 or 15 mg/kg once daily depending on the severity of the infection or amikacin 7.5 mg/kg twice daily. Patients with infections known to be caused by Pseudomonas aeruginosa were to be given concomitant treatment with ceftazidime. In the intent-to-treat population, i.e. patients who received at least one dose randomised treatment, a clinical cure or improvement at the end of treatment was seen in 112/125 (90%) isepamicin patients and 55/60 (92%) amikacin patients. The corresponding rates for patients with a primary diagnosis of pneumonia were 45/52 (87%) and 25/28 (89%). Cure/improvement rates for patients with P. aeruginosa as the causative pathogen (34 of whom also received ceftazidime) were 28/30 (93%) and 16/18 (89%), respectively. In the efficacy population (patients who had a valid pretreatment culture and who met other evaluability criteria), total elimination (documented or presumed if infection had resolved) of target pathogens occurred in 54/63 (86%) of isepamicin patients and 25/30 (83%) of amikacin patients. P. aeruginosa, Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus were commonly isolated pathogens. Treatment-related adverse were mainly mild or moderate in severity and occurred in 10% of isepamicin patients and 13% of amikacin patients. Four patients (3 isepamicin and 1 amikacin) discontinued treatment because of severe adverse events and a further isepamicin patient withdrew because of a mild adverse event. Nephrotoxicity and ototoxicity occurred infrequently.
    No preview · Article · Jul 1995 · Journal of chemotherapy (Florence, Italy)

  • No preview · Article · Jun 1994 · Tubercle and Lung Disease
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    ABSTRACT: The study aim was to evaluate the activity of aztreonam on phagocytosis and intracellular killing of Staphylococcus aureus ATCC6538 by human alveolar macrophages. Drug concentrations of 1, 10, 25, 100 micrograms/ml were assayed in culture medium. Aztreonam induces dose-dependent phagocytosis up to 25 micrograms/ml concentrations; with a phagocytosis index (PIa) of 1.18 +/- 0.2 at 1 microgram/ml; of 1.27 +/- 0.2 at 10 micrograms/ml; of 1.42 +/- 0.3 at 25 micrograms/ml. No phagocytosis increase or inhibition, with unchanged cell viability compared to controls, is shown at 100 micrograms/ml aztreonam (PI 1.03 +/- 0.3). Intracellular killing acts in a similar way: the killing index (KIa) is 1.27 +/- 0.3 at 1 microgram/ml concentrations; 1.38 +/- 0.3 at 10 micrograms/ml; 1.61 +/- 0.4 at 25 micrograms/ml whereas at 100 micrograms/ml the KIa is 1.03 +/- 0.3. This study shows aztreonam's ability to stimulate macrophages' functional activity against a microorganism (S. aureus) which is not susceptible to its antibacterial activity.
    No preview · Article · Mar 1994 · Journal of chemotherapy (Florence, Italy)
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    ABSTRACT: The bronchoalveolar compartment can be easily investigated with BAL (bronchoalveolar lavage) before and after antiblastic therapy. We studied 50 patients affected by primary lung cancer, of whom 31 served as a control group and 19 were submitted to BAL after chemo- and/or radiotherapy. Data from BAL performed in an unaffected lung area show that antiblastic therapy can produce alterations in the terminal airways without clinical evidence. Chemotherapy causes a significant impairment of the alveolo-capillary barrier. Radiotherapy is able to affect lymphocytes, with a CD4/CD8 reduction. The concomitance of both therapies produces synergistic effects. Immunomodulant therapy with thymostimulin in otherwise untreated lung cancer patients seems able to modify alveolar lymphocyte number and subsets, but these are preliminary data which need further substantiation.
    No preview · Article · Feb 1992 · Respiration

  • No preview · Article · Oct 1991 · Sarcoidosis
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    ABSTRACT: Twenty-three patients suffering from lower respiratory tract infections caused by Gram-negative germs were treated with aztreonam (AZT) administered according to two different regimens: 17 subjects (Group A) with 2 g i.v. every 12 h and 6 patients (Group B) with 4 g in 100 ml of saline every 24 hours. Group A included 8 cases of superinfected bronchiectasis, 8 purulent bronchitis and 1 gangrene caused by Gram-negative and anaerobic agents. Group B comprised 6 patients with severe bronchiectasis infection. Pseudomonas aeruginosa was isolated from the sputum in 10/23 cases. The treatment was performed for 10 days on the average. The local and systemic tolerability was good. Group B, with higher antibiotic sputum concentrations for at least 12 hours, attained a better response than Group A: with clinical cure in 100% vs 76% cured plus 18% improved patients; therapy lasted 9.5 days for Group B vs 10.8 days for Group A. Moreover, in 14 subjects affected by pulmonary interstitial diseases who underwent diagnostic broncho-alveolar lavage, we dosed AZT in lavage fluids about 1 hour after the injection of a 2 g dose (Group C: 8 cases) or a 4 g dose (Group D: 6 cases). In group D antibiotic concentrations were significantly higher (P less than 0.005) than group C, while all the parameters that usually define the intensity of the alveolar alterations were not significantly different. Therefore, aztreonam administration in a daily monodose seems able to assure higher and longer lasting concentrations at the site of infection.
    No preview · Article · Mar 1991 · Journal of chemotherapy (Florence, Italy)

  • No preview · Article · Apr 1990 · European Respiratory Journal
  • M Covi · G Velluti
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    ABSTRACT: Tuberculosis appears to be a diagnostic challenge and an important therapeutical problem in industrialized and in developing countries, where most infections occur. Besides several rifamycin derivatives, new molecules (fluorinated quinolones, macrolides, beta-lactam antibiotics) are being explored in the face of increasing bacterial-resistance with the aim of improving the efficacy and safety of anti-tuberculous drugs, shortening the period of treatment or allowing intermittent regimens. At present, in severe forms of the disease three or more of the available anti-tuberculous agents must be administered simultaneously for at least 3-4 months and two for the following 6-7 months. Nevertheless, a variety of highly effective 6 months regimens are currently used for the treatment of less severe tuberculosis.
    No preview · Article · Jan 1989 · Medicina (Florence, Italy)
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    ABSTRACT: We report the levels of concentration of ampicillin, dicloxacillin, and carbenicillin reached in the blood and in the expectoration following the administration of these drugs by rapid venous infusion, once every 24 h. The concentration of ampicillin in the blood serum varied from 150 to 180 micrograms/ml at the end of the infusion and from 30 to 3 micrograms/ml 4 afterwards and the dicloxacillin concentration from 150 to 120 micrograms/ml, and from 24 to 6 micrograms/ml. The concentration of ampicillin in purulent expectoration was 5-7 micrograms/ml and that of dicloxacillin 2.5-4 micrograms/ml. The concentration of carbenicillin in the plasma varied from 1,040 to 130 micrograms/ml, and in the expectoration it was around 15 micrograms/ml. Several cases of acute and chronic lung and bronchial diseases caused by bacteria have been treated by means of venous infusion once every 24 h and results were excellent.
    No preview · Article · Feb 1981 · Respiration
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    ABSTRACT: We report the levels of concentration of ampicillin, dicloxacillin and carbenicillin reached in the blood and in the expectoration following the administration of these drugs by rapid venous infusion, once every 24 h. The concentration of ampicillin in the blood serum varied from 150 to 180μg/ml at the end of the infusion and from 30 to 3 μg/ml 4 afterwards and the dicloxacillin concentration from 150 to 120 μg/ml, and from 24 to 6 μg/ml. The concentration of ampicillin in purulent expectoration was 5–7 μg/ml and that of dicloxacillin 2.5–4 μg/ml. The concentration of carbenicillin in the plasma varied from 1,040 to 130 μg/ml, and in the expectoration it was around 15 μg/ml. Several cases of acute and chronic lung and bronchial diseases caused by bacteria have been treated by means of venous infusion once every 24 h and results were excellent.
    No preview · Article · Jan 1981 · Respiration
  • M Covi · G Velluti · A Bisetti
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    ABSTRACT: At present the increased incidence of infections with mycobacteria other than tuberculosis and leprae bacilli seems to be correlated with several causes: improved diagnostic techniques, prolonged life expectancy, immunodepression. Rational chemotherapy depends upon the identification of the etiologic mycobacterium and the determination of its drug susceptibility. Besides the "classic" treatment with 3 or 4 antituberculous and, sometimes, nonantituberculous chemotherapics, clinical trials are in progress to assess the effectiveness of new molecules: rifamycin derivatives, fluorinated quinolones, anti-lepromatous drugs, and the latest macrolides. Yet at present, national and international data do not permit to define a standard treatment for every mycobacteriosis; in fact, the drug resistance is high and varies not only between different strains but also within the same strain; moreover, there are discrepancies between in vitro and in vivo results. When possible, appropriated surgery for circumscribed disease is recommended.
    No preview · Article · · Medicina (Florence, Italy)

Publication Stats

37 Citations
22.27 Total Impact Points

Institutions

  • 2002
    • Università degli Studi di Modena e Reggio Emilia
      • Department of Biomedical, Metabolical and Neurosciences
      Modène, Emilia-Romagna, Italy
  • 1995
    • Polyclinic of Modena
      Modène, Emilia-Romagna, Italy