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Biomedical subjects

G Velluti

Publications and source records attributed to G Velluti.

At least 19 recordsLinked to original sources
PubMed1995

Comparison of the efficacy and safety of isepamicin and amikacin in the treatment of acute lower respiratory tract infections caused by gram-negative organisms.

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.

Adult↗
PubMed1994

Activity of aztreonam in pneumology, Part 2: Influence on phagocytosis and intracellular killing of human alveolar macrophages.

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.

Adjuvants, Immunologic↗
PubMed1992

Semi-quantitative X-ray microanalysis of bronchoalveolar lavage samples from silica-exposed and nonexposed subjects.

To evaluate the possibility of quantifying alveolar dust burden in conditions of exposure to silica, four groups of subjects were submitted to bronchoalveolar lavage (BAL): 10 healthy control subjects and 39 patients affected by diffuse interstitial lung disease (DILD) never exposed to dust, 23 silicotic patients and 12 chronic bronchitis patients with a history of occupational exposure to silica dust. Five to ten million BAL recovered cells were analysed with an energy-dispersive X-ray microanalysis (EDXA) system to determine the silicon content, expressed in a semi-quantitative way as silicon to sulphur (Si/S) ratio. The results were independent of smoking habit. The Si/S median values (interquartile range in brackets) for the four groups were 0.53 (0.5-0.65), 0.60 (0.41-0.8), 1.23 (1.06-1.39), 1.31 (1.11-1.97), respectively. Silicotics and simply exposed individuals did not show a significant discrepancy, but they were both significantly different in comparison with normal and DILD patients without history of exposure (p less than 0.001). 14.3% false negative cases were found, and 4.1% false positive cases (none among normal subjects). We did not see any significant relationships between the amount of silicon and the duration of exposure or the degree of chest X-ray involvement. A study of cytocentrifuge slides from the same subjects by polarizing light microscopy revealed a lower sensitivity (34% false negative cases).(ABSTRACT TRUNCATED AT 250 WORDS)

Bronchitis↗
PubMed1991

Aztreonam activity in pneumology. Part 1: Clinical activity and pulmonary bioavailability of two different administration regimens.

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.

Adult↗
PubMed1988

Activities of human alveolar macrophages (HAMs). Note 1: Observations on phagocytosis and bacterial killing in the presence of miocamycin.

We studied the activity of human alveolar macrophages (HAMs) obtained by bronchoalveolar lavage (BAL) from human lungs. In particular, we studied in vitro phagocytosis and bacterial killing in basal conditions and in the presence of miocamycin (MOM), a macrolide antibiotic. At a dose of 600 mg every 12 hours, MOM concentrations in the serum were 2.60 micrograms/ml 1 hour after administration and 0.75 microgram/ml 8 h after. The antibiotic cannot be assayed by the microbiological method in the acellular liquid of alveolar lavage. After penetrating the HAMs, it can be detected at a concentration of about 0.4 mcirograms/1.10(6) HAMs. MOM was able to penetrate HAM cytoplasm without altering their vitality. As a matter of fact, the Trypan blue exclusion dye test was not modified after long incubation in the presence of MOM. The HAMs, resuspended in a RPMI 1640 enriched medium, were able to phagocytize either live Staphylococci or inert Latex beads of 1 micron. MOM stimulated the HAM phagocytosis on both Staphylococci and Latex beads. The increase in Latex phagocytosis, a relatively inert substance on which MOM should not be active, is a confirmation of the antibiotic's directed stimulation of the HAMs. Finally, we have seen that the HAMs, which were noteworthy in killing the phagocytized bacteria, were stimulated by MOM after only 30 minutes of contact with the antibiotic.

Anti-Bacterial Agents↗
PubMed1984

Chemiluminescence measurement of phagocytic activity of pulmonary macrophages in sarcoid alveolitis.

The phagocytic activity of alveolar macrophages in a group of patients with stage I and stage II fresh sarcoidosis has been studied in comparison with a group of healthy volunteers. The phagocytic activity has been measured by means of chemiluminescent emission recording. While no difference in the emission of chemiluminescence has been detected in polymorphonuclear leukocytes of patients and control subjects, a greater emission of chemiluminescence has been noted in the alveolar macrophages of sarcoid patients. Such a difference is statistically significant; its possible relation to alveolar inflammation has been considered.

Adult↗
PubMed1984

Bronchoalveolar lavage in the normal lung. 2. Cell distribution and cytomorphology.

Bronchoalveolar lavage, performed on 15 healthy volunteers, enabled quantification and characterization of the alveolar cell populations. The subjects studied were 8 nonsmokers (5 males, 3 females) and 7 smokers (6 males, 1 female). It was found that in the smokers the macrophages increased compared with nonsmokers, both in absolute number (419,000 vs. 138,000/ml; p less than 0.005) and in percentage (93.8 +/- 3.0 vs. 88.1 +/- 4.8%; p less than 0.02), causing a significant increase in the total number of cells recovered after bronchoalveolar lavage (471,000 vs. 163,000/ml; p less than 0.005). Lymphocytes and neutrophils do not significantly vary in the two groups, even though among the smokers there is a tendency for the concentration of these cells to increase in the lavage liquids. The importance of the data obtained from healthy subjects lies in the possibility thus afforded of having reference values for the study of various lung pathologies with bronchoalveolar lavage.

Adult↗
PubMed1983

Bronchoalveolar lavage in the normal lung. First of three parts: protein, enzymatic and ionic features.

Bronchoalveolar lavage was performed on 12 healthy volunteers, comprising 6 smokers and 6 nonsmokers, of ages between 21 and 52 years. The aim was to define normal variability of certain biochemical, immunologic, enzymologic and ionic parameters. The smoking habit was observed to exert a significant influence on the recovery percentage of lavage effluents (with recovery less in smokers, 53 vs. 69%) and particularly on the concentration of immunoglobulins in the lavage liquids. In particular, the IgG increased by about 4 times in smokers (1.05 vs. 0.26 mg/100 ml) and the IgA by about 3 times (0.35 vs. 0.11 mg/100 ml). The other parameters studied (total proteins, albumins, IgM, alpha 1-AT, K, Ca and several enzyme activities) did not differ significantly from one group to the other. Rather than an alteration in the blood-alveolar barrier from smoking, these data suggest a real local overproduction of immunoglobulins of classes G and A induced by the smoking habit. Moreover, the relatively slight individual oscillation in the values of the parameters studied in the two groups supports the possibility of employing them for diagnostic purposes in bronchopneumopathies.

Adult↗
PubMed1981

Concentrations of semi-synthetic penicillins in the plasma and in the expectoration, administered by means of intermittent vein perfusion.

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.

Ampicillin↗
PubMed1975

[Recent studies on the in vivo and in vitro activity of gentamicin].

The effect of gentamycin was investigated at the University of Modena Phthisiology and Respiratory Diseases Department. In vitro activity against most pathological Gram-positive and Gram-negative bacteria was observed. A dose of 4-5 mg/kg proved very effective in cases of bacteria-induced bronchopneumopathy. The drug was also active against penicillin-resistant staphylococci and Gram-negative bacteria with a known resistance to ordinary antibiotics.

Acinetobacter↗