Search PubMed⌕ Search

Biomedical subjects

R Maserati

Publications and source records attributed to R Maserati.

At least 55 records · Page 3Linked to original sources
PubMed1997

Hydroxyurea and didanosine is a more potent combination than hydroxyurea and zidovudine.

The in vitro and in vivo antiviral activity of hydroxyurea in combination with either zidovudine or didanosine was evaluated in primary human peripheral mononuclear cells and in a cohort of 29 asymptomatic patients infected with HIV. In vitro, hydroxyurea alone did not significantly affect HIV replication, whereas the combination of hydroxyurea with didanosine was more effective than the combination of hydroxyurea with zidovudine. Our clinical results confirmed these studies. Patients were randomly assigned to five arms (zidovudine, hydroxyurea or didanosine monotherapy, or hydroxyurea in combination with either zidovudine or didanosine) to evaluate preliminary safety and efficacy. Bone-marrow toxicity occurred in two patients treated with zidovudine plus hydroxyurea, alopecia was reported in one patient treated with hydroxyurea monotherapy, and there were no toxic effects recorded in the remaining three groups. Plasma viraemia was not influenced by hydroxyurea monotherapy, and the hydroxyurea-zidovudine combination did not give any advantage over either zidovudine or didanosine monotherapy (0.3-0.5 log decrease in plasma viraemia). In contrast, a 1.1 log drop in plasma viraemia was observed in patients treated with hydroxyurea plus didanosine, this reduction was sustained throughout the 24-week course of the treatment. Combination therapy with hydroxyurea and didanosine exhibited statistically significant improvements compared with the other therapeutic approaches. Although further clinical trials are required, these results suggest that hydroxyurea in combination with didanosine might be an effective and well-tolerated, simple and affordable, treatment for HIV infection.

Adult↗
PubMed1996

Pharmacokinetics of hydroxyurea in patients infected with human immunodeficiency virus type I.

In a prospective, randomized, controlled, three-arm study, the pharmacokinetics of hydroxyurea administered as an antiviral agent in patients infected with human immunodeficiency virus type 1 (HIV-1) were evaluated. The three arms of the study consisted of azidothymidine (AZT) 250 mg twice daily, hydroxyurea 500 mg twice daily, or a combination of the two. Nine patients receiving hydroxyurea in monotherapy (n = 4) or in combination with AZT (n = 5) agreed to undergo multiple venipunctures for pharmacokinetic analysis. Sample collection was performed at steady-state conditions and serum concentration-time data for hydroxyurea were fitted using a one-compartment model. Mean (+/- standard deviation) peak concentration (Cmax) was 0.135 +/- 0.06 mmol/L and mean trough level (Cmin) was 0.0085 +/- 0.003 mmol/L. Mean concentration at steady state was 0.045 +/- 0.006 mmol/L. Apparent clearance (Cl/F) was 0.18 +/- 0.005 L/hr/kg, and half-life (t1/2) was 2.5 +/- 0.5 hours. Hydroxyurea given orally to patients infected with HIV-1 was well absorbed from the gastrointestinal tract, with a tmax of 0.85 to 0.96 hours after ingestion. Serum levels of hydroxyurea ranged from 0.01 to 0.13 mmol/L. These values are similar to the concentrations (between 0.01 and 0.1 mmol/L) demonstrated to inhibit HIV-1 in vitro. Our data show that hydroxyurea given at a dosage of 500 mg twice daily is sufficient to yield serum concentrations potentially useful for in vivo inhibition of HIV-1.

Adult↗
PubMed1996

Rhodococcus equi infection in HIV-positive subjects: a retrospective analysis of 24 cases.

Rhodococcus equi causes a rare infection in immunocompromised hosts. We describe 24 cases of infection in patients with AIDS-related complex (ARC)/acquired immunodeficiency syndrome (AIDS). Pneumonia was always the first manifestation of R. equi infection, but extrapulmonary involvement was also observed. The main sources of bacteria were sputum, bronchial washings and blood. The strains isolated were mainly susceptible to erythromycin, vancomycin, teicoplanin, rifampicin, imipenem and aminoglycosides. Initial treatment should involve an intravenously administered antibiotic combination therapy including imipenem or vancomycin or teicoplanin, followed by orally administered maintenance combination therapy. Drug combinations should be investigated for serum bactericidal activity in vitro. Surgery does not increase survival time and should only be performed in cases that do not respond to antibiotic treatment. Presumptive risks of infection (contact with horses or farm dust, or cohabiting with people affected by R. equi infection) were present in more than 50% of patients. This finding, and the frequency of bacteria in the sputum, are not sufficient proof of transmission between humans, but do suggest the need for respiratory isolation of patients affected by R. equi pneumonia.

AIDS-Related Complex↗
PubMed1996

Clinical and pharmacokinetic evaluation of a new lipid-based delivery system of amphotericin B in AIDS patients.

To evaluate the safety, tolerance and pharmacokinetics of a new formulation of amphotericin B (AmB; CAS 1397-89-3) 18 AIDS patients treated for different kinds of mycoses were studied: oropharingeal and/or esophageal azole-resistant candidiasis (9), CNS cryptococcosis (7) or aspergillosis (2). Amphotericin B daily dose was infused in 100 ml of a lipid emulsion. The patients aged from 26 to 54 years with body weight ranging from 42 to 89 kg. Blood samples were collected at fixed intervals and plasma stored at -20 degrees C until tested by a specific HPLC assay. The individual kinetic analysis of plasma drug levels was performed by a two-compartment open model. The data were analyzed using P-Pharm, a computer program designed for population pharmacokinetic analysis that allows pooling of data. The effect of a variety of demographic factors on clearance and volume of distribution was investigated. The clearance and the apparent volume of distribution were, respectively, (mean +/- SD): 0.037 +/- 0.015 l/h/kg and 0.45 +/- 0.32 l/kg. The interindividual variability in AmB clearance and volume of distribution was modelled with proportional error with an estimated coefficient of variation of 40.6% and 70.9%, respectively. Clinical and biological tolerance was very good and no patient experience infusion-related adverse effects or hematologic and hepatic toxicity; a moderate renal failure occurred in only one patient.

Acquired Immunodeficiency Syndrome↗
PubMed1996

The incidence of nosocomial infections in a pneumology division and intermediate intensive care unit.

It has been shown that the problem of nosocomial infections is different in each specialist hospital division, and it is important to be aware of the local situation and to identify the specific problems. In order to set up an effective prevention programme and in the setting of a general system of control of nosocomial infection, we studied the incidence of infections and correlated the pathogenic organisms appearing during hospitalization in patients admitted to our Pneumology Division and Intermediate Intensive Care Unit over a period of 12 months. A nosocomial infections incidence of 13% was observed and 75% of these were respiratory, 21% urinary and 4% other infections. Seventy two percent of pathogenic agents were Gram-negative bacilli and 28% Gram-positive cocci. The site-specific rates of infections observed are related to intrinsic (host dependent) and extrinsic (non-host-dependent) risk factors that have not been exhaustively evaluated in the present study. However, the data so far collected will allow us to redirect the resources used in the control of nosocomial infections by targeting efforts at the surveillance of better defined groups of patients and by achieving data more suitable for comparisons between hospitals.

Cross Infection↗
PubMed1996

[Role of clinical pharmacology in the monitoring of therapy of HIV-infected subjects].

The number of subjects with HIV infection or full-blown Acquired Immunodeficiency Syndrome (AIDS) is increasing throughout the world and the range of related opportunistic conditions (infections, neoplasms or degenerative disorders) is also increasing. Consequently, AIDS patients are likely to be prescribed a great number of different drugs. HIV infection is a progressive phenomenon, characterized by inevitable and often irreversible changes which may influence drug disposition, enhancing the risk of toxic adverse effects and drug interactions. One of the stages for the development of new agents and the establishment of an effective therapy is to conduct pharmacokinetic studies. Even though such studies are difficult to realize in AIDS subjects, the knowledge of altered pharmacokinetics of a drug in disease states offers an unique approach for improving and perhaps optimizing the therapeutic management. The purpose of this article is to review our current understanding of how HIV infection influences the various processes of drug disposition (i.e. absorption, distribution, metabolism and excretion).

AIDS-Related Opportunistic Infections↗
PubMed1996

[Clinical significance of diplopia in HIV infection. Assessment of a personal caseload and review of the literature].

Diplopia is one of the neuro-ophthalmic manifestations that can be observed during HIV-infection. The etiologic agents of diplopia in HIV-positive patients can be identified with HIV itself or opportunistic pathogens or other related conditions. We reviewed the clinical records of 13 HIV-positive patients with mono or bilateral diplopia, focusing on etiologic agents, clinical evaluation and prognosis. This review encompassed all cases observed from January 1992 to June 1995 at the Infectious Diseases Department, Policlinico S. Matteo, University of Pavia. All patients underwent a complete ophthalmologic examination, including visual acuity, anterior segment evaluation with biomicroscopy, dilated indirect ophthalmoscopy and ocular motility evaluation (with Cover test and Hess-Lancaster test). If requested by clinical findings, radiologic (TC and/or MRI) and cerebrospinal fluid examination were performed in some patients. The most common causes of diplopia-CNS lesions or ocular diseases-, resulted in agreement with those reported in the literature (T. gondii, C. neoformans, non-Hodgkin lymphomas, HIV, JC virus, CMV). We were able to confirm, according to our experience, that diplopia occurrence is often a negative prognostic factor, since it is commonly associated with CNS conditions. In most cases diplopia can herald a near demise (8 patients on 13 died with 60 days from diplopia onset). In those cases where a treatment was available (2 cases of cryptococcosis, 1 case of neurotoxoplasmosis and 1 case of CMV retinitis) a complete resolution of neuro-ophthalmic symptoms was achieved.

Adult↗
PubMed1995

Ocular infections: antibiotics and bacterial adhesion on biomaterials used in ocular surgery.

The in vitro antibacterial activity of ofloxacin, sagamycin and other antibiotics was evaluated against 85 bacterial isolates [coagulase-negative staphylococci (CNS), n = 37, Staphylococcus aureus, n = 28, and Pseudomonas aeruginosa, n = 20] obtained from patients with ocular infections. The antistaphylococcal activity of ofloxacin was quite elevated with a 90% minimal inhibitory concentration (MIC90) of 1.56 mg/l against CNS and S. aureus. Rokitamycin and erythromycin showed a good activity against methicillin-sensitive staphylococci, but were less active than ofloxacin and sagamycin against methicillin-resistant strains (MIC90 > 100 mg/l). Sagamycin was highly effective against staphylococci (MIC90 0.78 mg/l) and appeared to be the most active compound against P. aeruginosa (MIC90 6.25 mg/l), followed by ofloxacin, tobramycin and gentamicin. In a successive part of the study, the adhesive properties of slime-producing staphylococci were tested on biomaterials used in ocular surgery. Intraocular lenses, Silastic sheetings, circling bands and grooved strips showed a high affinity for slime-producing strains, while round silicone sponges were not covered by bacterial biofilm. In the last part of our study, we demonstrated how subMIC levels of ofloxacin increased the adhesion of slime-producing staphylococci. Our data confirmed the excellent activity of ofloxacin and sagamycin against ocular pathogens and the key role of adhesion in promoting colonization and infections of biomaterials.

Anti-Bacterial Agents↗
PubMed1995

[Not Available].

Rhodococcus equi is a facultative intracellular, obligate aerobe, partially acid fast, gram-positive pathogen that causes cavitary pneumonia in animals and immunocompromised humans. We describe 8 cases of R. equi pneumonia in patients with advanced HIV infection (CD4 counts less than 100/mm3), 7 males and 1 female (mean age 30.8 years), observed between 1991 and 1994. A history of exposure to farm animals was found in 4 patients. The most common presenting symptoms were fever, malaise, dyspnea, cough and hemoptysis, chest pain and weight loss. Chest x-rays showed tipical focal area of consolidation throughout the lung (3 upper, 3 lower and 2 middle fields) associated with cavitation in 4 cases. The definitive diagnosis in our hands was delayed only in the first case in which conflicting data resulted from blood culture (Bacillus sp. isolation) and sputum examen (acid-fast bacterium in the Ziehl-Neelsen stain). Final microbiological diagnosis depended on blood cultures (n=5), bronchoalveolar lavage (n=1), sputum (n=1), lung biopsy (n=1). All the patients were treated with prolonged courses of antibiotic therapy (259 days, range 120-340 in 6 dead patients; more than one year and two months respectively in two patients alive). According to microbial susceptibility TMP/SMX, vancomycin, imipenem, rifampin, aminoglycosides, macrolides and quinolons were more frequently used. Resistant R. equi mutants were selected during therapy with TMP/SMX (n=2), rifampin (n=1) and erythromycin (n=1). Five patient underwent pulmonary lobectomy after exclusion of metastatic bacterial lesions. Only 2 patients are alive, one after 365 days of antibiotic therapy and upper lung lobectomy, one after 60 days of antibiotic therapy. Optimal antimicrobial therapy and the role of surgery remain, in our experience, uncertain.

English Abstract↗
PubMed1993

Bronchial reactivity to methacholine in HIV-infected individuals without AIDS.

To evaluate bronchial reactivity to methacholine in human immunodeficiency virus (HIV) infection, we submitted 25 HIV-seropositive subjects without full-blown AIDS and 25 HIV-seronegative subjects, all inmates in a drug rehabilitation center for previous intravenous drug abuse, to interview and to bronchial challenge with methacholine. Four (16 percent) HIV-seropositve and three (12 percent) HIV-seronegative subjects noted bronchospastic symptoms. Baseline FEV1 and MEF50 percent were within the normal range in every patient. Bronchial hyperreactivity to methacholine (PD20FEV1 < 1,400 micrograms) was found in two (8 percent) HIV-seropositive and in four (16 percent) HIV-seronegative subjects, with no significant difference in the frequency between the two groups. We conclude that HIV infection without AIDS in intravenous drug users does not appear to be associated with an increased frequency of bronchospastic disorders and to bronchial hyperreactivity to methacholine.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Clarithromycin-ciprofloxacin-amikacin for therapy of Mycobacterium avium-Mycobacterium intracellulare bacteremia in patients with AIDS.

A combination of clarithromycin, ciprofloxacin, and amikacin for the treatment of Mycobacterium avium-Mycobacterium intracellulare bacteremia was evaluated in 12 AIDS patients. Mycobacteremia cleared in all patients by 2 to 8 weeks of treatment, and symptoms resolved. Four patients died; all had negative blood cultures until death, and disseminated M. avium-M. intracellulare complex infection was not considered the primary cause of death.

Acquired Immunodeficiency Syndrome↗
PubMed1991

HIV-related encephalitis presenting as convulsant disease.

Because of the growing incidence of neurological disorders in HIV-infected patients, an early detection of the disease seems to be of paramount importance, especially in asymptomatic subjects. By using electroencephalography coupled with computerized spectral analysis and "mapping" (EEG-CSA), paroxysmal sharp activity was detected in 26 patients belonging to different stages of HIV infection. Seven of them (27%) were also symptomatic, (table; see text) showing signs of convulsant disease. The presence of focal or generalized paroxysmal activity, often associated with seizures, might suggest an early localization of HIV in cortical structures.

AIDS Dementia Complex↗
PubMed1988

Bacterial adherence and upper respiratory tract disease: a correlation between S. pyogenes attachment and recurrent throat infections.

The attachment of bacteria to mucosal surfaces is the initial event in the pathogenesis of infectious diseases. The authors present a study about the adherence of strain of S. pyogenes isolated in subjects with recurrent tonsillitis. A correlation was found between the adherence ability of the bacterium and the number of episodes per year. The study about the SIgA, the infection development and the bacterium adherence showed a direct correlation between SIgA levels and the number of phlogistic episodes. The importance of the role assumed by bacterial adherence in the genesis of the phlogistic process is to be emphasized yet again.

Bacterial Adhesion↗
PubMed1987

Teicoplanin in the therapy of staphylococcal neuroshunt infections.

Three patients with staphylococcal infection of neuroshunt, two with ventriculoperitoneal and one with external ventricular derivation, were treated with teicoplanin given intravenously (iv) or intraventricularly (ivt), two patients were adults, while the third was an infant. The causative organisms were methicillin-sensitive Staphylococcus epidermidis (MSSE) in the first two cases and methicillin-sensitive Staphylococcus aureus (MSSA) in the paediatric patient. Patient No. 1 was given teicoplanin iv (400 mg/day) and subsequently ivt (20 mg/day). CSF teicoplanin levels were always below 1 microgram/ml during the first part of the treatment; after the institution of ivt therapy, drug levels ranged from 20 to 35 micrograms/ml (mean 26.4). The patient was cured after 20 days of a combination treatment (ivt teicoplanin plus rifampin, 900 mg/day, iv). Patient No. 2 was given teicoplanin 400 mg/day, iv, for two weeks; its low levels in CSF (always below 0.5 microgram/ml) accounted for the failure to eradicate the MSSE. A new regimen with teicoplanin, 20 mg/day plus netilmycin, 15 mg/day, both ivt, cured the patient in two weeks. Teicoplanin levels in the CSF ranged from 12.5 to 33 micrograms/ml (mean 18.3). Patient No. 3, an 8-month-old infant, was placed on teicoplanin, 5 mg/day ivt plus chloramphenicol, 180 mg/day iv, after several other antibiotic trials had failed to eradicated a MSSA infection of his external ventricular derivation. The therapy cleared the infection in one week (CSF teicoplanin levels: 30 to 38, mean 34 micrograms/ml). Teicoplanin (iv or ivt) was well tolerated without any significant side-effects; its role in the treatment of staphylococcal neuroshunt infections deserves further studies.

Adolescent↗
PubMed1985

Comparison of ciprofloxacin with azlocillin plus tobramycin in the therapy of experimental Pseudomonas aeruginosa endocarditis.

The efficacy of ciprofloxacin (Bay o 9867), a promising new quinolone, was compared with the efficacy of azlocillin plus tobramycin in rabbits with experimentally induced Pseudomonas aeruginosa endocarditis. The MBCs of ciprofloxacin, azlocillin, and tobramycin against the test strain were 0.5, 8, and 4 micrograms/ml respectively. Ciprofloxacin at a concentration of 50 mg/kg or azlocillin at a concentration of 200 mg/kg in combination with tobramycin at a concentration of 5 mg/kg was administered intramuscularly at 8-h intervals for 4 days. Both regimens produced median peak serum bactericidal titers of 1:8. The concentrations of ciprofloxacin, azlocillin, and tobramycin in serum, 1.8 +/- 0.7, 154 +/- 48, and 9.1 +/- 2.4 micrograms/ml (mean +/- standard deviation), respectively, closely approximated concentrations found in humans after accepted dosages. At the end of treatment, the titers of P. aeruginosa were 3.0 +/- 1.6 log10 CFU/g of vegetation (mean +/- standard deviation) for recipients of ciprofloxacin and 3.2 +/- 1.3 log10 CFU/g of vegetation for recipients of azlocillin plus tobramycin. These values compared with control titers of 7.3 +/- 1.6 CFU/g. These data indicate that at the doses used, ciprofloxacin was as effective as azlocillin plus tobramycin in the treatment of P. aeruginosa endocarditis in rabbits. Since the latter drug combination has proven efficacy, ciprofloxacin deserves further evaluation in the therapy of systemic infections in animal models and in humans.

Animals↗
PubMed1985

Ceftazidime in the therapy of pseudomonal meningitis.

In this study we report about the efficacy and tolerability of ceftazidime in the treatment of 10 cases of pseudomonal meningitis (nine Pseudomonas aeruginosa and one Pseudomonas cepacia). The 10 patients had a pseudomonal infection of the central nervous system (CNS) complicating neurosurgical procedures or developed on a preexisting immunodepressing condition; four patients were of pediatric age. All isolates were sensitive to ceftazidime with MICs ranging from 0.39 to 3.12 micrograms/ml. Ceftazidime was given intravenously at the dosage of 100-150 mg/kg/day. In seven cases amikacin was associated by intralumbar or intraventricular instillation. The duration of ceftazidime treatment ranged from 9 to 49 days with a mean of 22.2. Eight cases out of ten were cured bacteriologically and clinically, while the remaining two were cured after treatment with other antibiotics. Concentrations of ceftazidime in serum and in lumbar and/or ventricular cerebrospinal fluid (CSF) were obtained in four cases; the mean concentration in lumbar CSF was 12.2 micrograms/ml and in ventricular 3.3 micrograms/ml. The study demonstrated that ceftazidime is effective in the treatment of Pseudomonal meningitis.

Adolescent↗