Biomedical subjects

D Galante

Publications and source records attributed to D Galante.

At least 37 records · Page 2Linked to original sources

PubMed1986

Correlation of beta-lactamase stability and antibacterial activity of beta-lactams in beta-lactamase-producing bacteria and respective transconjugants.

A total of 343 Gram-negative bacteria were isolated and identified from urine specimens of patients with urinary tract infections. All the bacteria were investigated for their production of beta-lactamases by the nitrocefin test. beta-lactamase-producing strains were tested by the Datta method to detect any transfer of beta-lactamase production to a receiving E. coli K12 RN-strain. MICs of six beta-lactamase-stable compounds (ceftazidime, ceftriaxone, cefamandole, cefoxitin, cefotaxime, cefuroxime) were determined against all the beta-lactamase transferring bacteria and their respective transconjugants by a miniaturized dilution broth method. beta-lactamases produced by donors and transconjugants were purified and identified by determination of the isoelectric point by focusing; their hydrolytic activity was assessed by a spectrophotometric method using cytochrome c reduction. A total of 129 bacteria out of 343 produced beta-lactamases and 27 of these transferred the beta-lactamase production by conjugation. The beta-lactamases isolated from donors and transconjugants had the same pl and the same substrate profile. Ceftazidime was more stable to all the beta-lactamases isolated and more active against all the bacteria examined than the other compounds.

Anti-Bacterial Agents↗

PubMed1986

Ciprofloxacin in the treatment of urinary and respiratory tract infections in patients with chronic liver disease.

The clinical efficacy and tolerability of ciprofloxacin (Bay o 9867), a new quinolone compound with broad antibacterial spectrum, was evaluated in 28 patients hospitalized in the first Clinic of Infectious Diseases, University of Naples, Italy, for chronic liver disease and affected by respiratory (RTI) or urinary tract infections (UTI). Ciprofloxacin was administered at the dosage of 500 mg twice a day after the isolation of the organism responsible for the infection and after the determination of its sensitivity in vitro to ciprofloxacin. The therapy was carried on for 5-10 days depending upon the severity of infection and clinical evaluation. Bacteriological cultures and hematochemical analysis were always performed during and after the therapy. Ciprofloxacin was very effective in all the treatments of UTI and RTI under examination, both for the disappearance or improvement of clinical signs and for eradication of the responsible microorganisms. No significant side effects or change in the hematochemical tests were observed.

Adult↗

PubMed1986

Antibacterial activity of six beta-lactams and six quinolones against urinary gram negative bacteria.

Three hundred eighty seven gram negative bacterial strains were isolated from urine specimens of as many patients affected by urinary tract infections. Susceptibility of bacteria to six quinolones (ciprofloxacin, norfloxacin, oxolinic, nalidixic, pipemidic acid and cinoxacin) and six beta-lactams (ceftazidime, ceftizoxime, ceftriaxone, cefamandole, cefoxitin and cefotaxime) was studied determining the minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) of each compound by a miniaturized dilution broth method. Ciprofloxacin, a quinoline carboxylic acid compound structurally related to nalidixic acid, and ceftazidime a new beta-lactamase stable beta-lactam showed a much higher antibacterial activity against all the bacterial strains including Pseudomonas. The best antibacterial activity of ciprofloxacin and ceftazidime was expressed either by the lower MICs and lower MBCs with respect to those of the other compounds or by a low MBC/MIC ratio, which represent an important clinical advantage in clinical practice.

Anti-Bacterial Agents↗

PubMed1985

Comparative in vitro activity of ciprofloxacin and five other quinoline derivatives against gram-negative isolates.

A total of 375 Gram-negative bacterial strains were isolated from midstream urine specimens of the same number of patients affected by urinary tract infections. All bacteria were identified by standard bacteriological methods and their susceptibility to six quinoline derivatives (ciprofloxacin, cinoxacin, norfloxacin, oxolinic acid, pipemidic acid, nalidixic acid) was studied by determining the MICs and MBCs for each compound using a miniaturized dilution broth method in microtitre plates and twofold dilutions of each drug from 256 to 0.12 mcg/ml. Ciprofloxacin, a new quinoline carboxylic acid compound structurally related to nalidixic acid, showed a much higher antibacterial activity against all bacterial strains under examination, including Pseudomonas, than the other compounds, except for norfloxacin. The MIC90 and MBC90 of ciprofloxacin never exceeded 1 mcg/ml with any of the bacterial species; and MBC/MIC ratios were very low, which represents an important clinical advantage. Only norfloxacin showed comparable effectiveness. No bacterial strain showed resistance to the drug and the MIC90 and MBC90 never exceeded 8 mcg/ml.

Bacteriuria↗

PubMed1985

Cross resistance of quinolone derivatives in gram-negative bacteria.

A total of 127 Gram-negative bacteria resistant to nalidixic acid were isolated from as many patients affected by urinary tract infections and hospitalized in the first Clinic of Infectious Diseases, University of Naples. Enterobacteria were identified by Enterotube system (Roche) and API 20 system (Ayerst). Non-fermentative bacteria were identified by OXI/FERM system (Roche). The following bacteria were collected: Escherichia coli 50, Proteus spp. 35, Enterobacter agglomerans 12, Serratia sp. 5, Pseudomonas aeruginosa 25. The in vitro antibacterial activity of nalidixic acid and three other quinoline derivatives (pipemidic acid, oxolinic acid and ciprofloxacin) were studied by determining the MICs by a miniaturized dilution broth method. The MICs were compared to evaluate the eventual cross resistance to the drugs under examination within each bacterial species. The results showed that 23% of bacteria were resistant to nalidixic acid, pipemidic acid and oxolinic acid; 49.6% to nalidixic and pipemidic acid and 0.7% to nalidixic acid and oxolinic acid. On the other hand none of the bacteria were resistant to ciprofloxacin. The last showed very low MICs against all the bacteria under examination, including Pseudomonas and Serratia. The high antibacterial activity of ciprofloxacin even against bacteria highly resistant to the other quinolines could be due to a greater affinity of the target sites or to the better permeability of resistant strains to the newer drug or because it is unaffected until now by mutations of genes responsible for cross resistance.

Ciprofloxacin↗

PubMed1985

Occurrence of gram negative bacteria in midstream bladder urine and their sensitivity to quinoline derivatives.

326 gram negative bacteria have been isolated and quantitative bacteria counts performed from midstream urine of as many patients affected with symptomatic and non symptomatic urinary tract infections. Susceptibility of bacteria to four quinoline derivatives (Norfloxacin, Oxolinic acid, Pipemidic acid and Nalidixic acid) was studied determining the minimal inhibitory concentrations (MICs) of each drug by a miniaturized dilution broth method. The frequency of bacterial species isolated, the frequency of symptoms and the frequency of bacterial counts were studied to establish a possible relationship between these data. It has been observed that patients affected with pyuria without any other subjective symptoms demonstrate a colony count ranging between less than 10(4) and greater than 10(5) bacterial/ml of urine and these bacteriuria were determined by several different bacterial species. E. coli was much more frequently responsible for low or high count bacterial infections of the urinary tract than other species. In fact E. coli was detected in 64.4% of patients, P. mirabilis in 15.9%, E. agglomerans in 5.2%, P. aeruginosa in 4.9. Other species were detected in much lower percentages. Norfloxacin proved to be the most effective drug in vitro, out of those under examination. Its MIC50 never exceeded 8 mcg/ml even against Pseudomonas and Serratia strains, which were resistant to all the other antimicrobial agents.

Adolescent↗

PubMed1985

Comparative activity of ceftizoxime and four other cephalosporins against gram negative bacteria and their sensitivity to beta-lactamases.

The in vitro activity of ceftizoxime compared with other beta-lactamase stable compounds was assessed against recent urinary gram negative isolates. 343 bacterial strains were isolated from patients affected by UTI, identified by standard bacteriological methods and investigated for their production of beta-lactamases by Nitrocefin test. MICs and MBCs of ceftizoxime, ceftriaxone, cefamandole, cefoxitin and cefotaxime were determined by a miniaturized dilution broth method against all beta-lactamase producing bacteria (129 out of 343). Sensitivity of antibiotics to beta-lactamases isolated and semi-purified by ultrasonic disruption and high speed centrifugation was assessed by a spectrophotometric method. In vitro antibacterial activity of each antibiotics was correlated to their sensitivity to isolated beta-lactamases. Ceftizoxime showed lower MIC and MBC values and lower MBC/MIC ratio than the other compounds against all the bacteria including Pseudomonas. Ceftizoxime was not hydrolized by any isolated beta-lactamase.

Cefotaxime↗

PubMed1984

Comparative in vitro activity of norfloxacin and four other chemotherapeutics against urinary gram-negative isolates.

Three hundred seventy-five Gram-negative bacterial strains were isolated from urine specimens of as many patients affected by symptomatic or asymptomatic urinary tract infections. Susceptibility of bacteria to five chemotherapeutics (norfloxacin, oxolinic acid, pipemidic acid, nalidixic acid and nitrofurantoin) was studied determining minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of each compound by a miniaturized dilution broth method. Norfloxacin, a quinoline carboxylic acid compound structurally related to nalidixic acid, showed a much higher antibacterial activity against all bacterial strains under examination including Pseudomonas sp. The best activity of norfloxacin was expressed either by lower MICs and lower MBCs with respect to those of the other compounds, or by a low MBC/MIC ratio, which represents an important advantage in clinical practice.

Anti-Infective Agents, Urinary↗

PubMed1984

Comparative activity of ceftazidime and four other cephalosporins against gram-negative bacteria and their sensitivity to beta-lactamases.

The in vitro activity of ceftazidime compared with other beta-lactamase stable compounds was assessed against recent Gram-negative isolates. Three hundred forty-three bacterial strains were isolated from patients affected with UTI, identified by standard bacteriological methods and investigated for their production of beta-lactamases by the Nitrocefin test. MICs and MBCs (minimum inhibitory concentrations and minimum bactericidal concentration) of ceftazidime, cefamandole, cefoxitin, cefotaxime and cefuroxime were determined by a miniaturized dilution broth method against all beta-lactamase producing bacteria (129 out of 343). Sensitivity of the antibiotics to beta-lactamases isolated and semipurified by ultrasonic disruption and high-speed centrifugation was assessed by a spectrophotometric method. The in vitro antibacterial activity of each antibiotic was correlated to its sensitivity to isolated beta-lactamases. Ceftazidime showed lower MIC and MBC values and lower MBC/MIC ratios than the other compounds against all the bacteria including Pseudomonas spp. In addition, ceftazidime was not hydrolyzed significantly by any isolated beta-lactamases.

Ceftazidime↗

PubMed1983

[Sensitivity of 5 beta-lactam antibiotics to beta-lactamase isolated from E. coli and its respective transconjugates].

54 beta-lactamase producing E. coli were tested to observe their eventual capacity to transfer beta-lactamase production by conjugation to a receiving E. coli K12 C600 Na-. About 16% (9/54) of these strains transferred beta-lactamase producing capacity. MICs of five beta-lactam antibiotics (Ampicillin, Cephaloridine, Cephalexine, Cefuroxime, Cefotaxime) were performed against E. coli donors and E. coli K12 C600 transconjugates. It was observed a remarkable increase only of Ampicillin MICs against all transconjugates++. Beta-lactamases produced by donors and transconjugants were isolated and purified by sonication and high speed centrifugation. Sensitivity of the six antibiotics to these purified beta-lactamases was assessed by a spectrophotometric method that utilizes the velocity of cytochrome c reduction. beta-lactamases produced by transconjugants have identical substrate profile that beta-lactamases produced by donors.

Ampicillin↗

PubMed1983

[In vitro activity of beta-lactam antibiotics and their sensitivity to beta-lactamase].

beta-lactamase production was evaluated by chromogenic cephalosporin 87/312 in 116 E. coli isolated from clinical sources. Such test revealed beta-lactamase production in 54 strains out of 116 (46%): MICs of eight beta-lactam antibiotics (Ampicillin, Piperacillin, Cefazoline, Cephaloridine, Cephalexine, Cefuroxime, Cefotaxime, Cefotaxime) were determined using a miniaturized dilution broth method. Cefotaxime and Ceftriaxome and Ceftriaxone showed the highest antibacterial activity. All beta-lactamases produced by E. coli strains under examination were isolated and purified by ultrasonic disruption and high speed centrifugation. Sensitivity of the eight antibiotics to purified beta-lactamases was assessed by a spectrophotometric method that utilizes the velocity of cytochrome c reduction. The sensitivity to beta-lactamases was reflected in the in vitro activity of the antibiotics as assessed by the determination of the MICs.

Anti-Bacterial Agents↗

PubMed1983

Hyperendemicity of viral hepatitis in the Neapolitan area: an epidemiological study.

An epidemiological study was performed in order to evaluate the diffusion pattern and risk factors in an area of hyperendemicity of viral hepatitis in the Neapolitan hinterland. Eight hundred-fifty seven asymptomatic subjects, aged 10 to 65 years, who consecutively went to the public health office of the city of Afragola to ask for a health certificate, were studied. They were interviewed with an epidemiological questionnaire and tested for a basic liver profile and serological markers of both hepatitis A and B viruses. Ninety-five percent of the studied population, had anti-HAV with a prevalence of 73% in the class 10-14 years, and of 98% in the class 45-65 years; 78% had either HBsAg or antibodies anti-HBV (60% in the class 10-14 years and 96% in the class 45-65 years). Healthy carriers state was found in 11.4% of the population and acute asymptomatic type B hepatitis in 3%. For HBV infection the interhuman contact in the family setting appeared to play a major role in viral diffusion. Other favouring factors appeared to be the ingestion of raw shellfish and parenteral therapies with glass syringes not properly sterilized. The data suggest that strategies of prevention of hepatitis diffusion in the Neapolitan area should be based on both reinforcing hygienic measures and the educational level of population and active prophylaxis addressed to people in the very young age.

Adolescent↗

PubMed1983

Rashes associated with intravenous administration of ampicillin.

532 patients under intravenous Ampicillin therapy have been included in the trial to evaluate the eventual onset of rashes. These patients have been divided into two groups: the first group comprised of patients affected with acute or chronic liver diseases, the second one with diseases of bacterial etiology. In the first group Ampicillin has been utilized either for its antiammoniaemic activity or to treat urinary or respiratory tract infections of bacterial origin. Ampicillin has been administered intravenously at the dosage of 1-6 g daily. Only 18 patients (3.4%) out of 532 under examination have shown skin reaction during treatment. It is suggestive that the low incidence of Ampicillin rashes observed is due to the way of administration of the drug.

Adolescent↗

PubMed1982

Decreased phagocytic and bactericidal activity of the hepatic reticuloendothelial system during chronic ethanol treatment and its restoration by levamisole.

The effect of chronic ethanol feeding (3 weeks) on the phagocytic and the bactericidal activity of hepatic RES versus viable Escherichia coli was studied using the isolated rat liver perfused with a serum-containing medium. Controls or ethanol-fed animals were used as liver or serum donors. The bactericidal activity of serum from ethanol-fed rats was similar to controls and accounted for the disappearance of nearly one-tenth of the bacterial inoculum from the system. When control livers were perfused with a medium containing serum from ethanol-fed animals, phagocytosis was comparable to controls while intracellular killing was greatly reduced. When livers were isolated from ethanol-fed rats, phagocytosis was significantly depressed and no killing occurred, irrespective of the source of serum. Levamisole was able to restore the macrophage activity depressed by ethanol. Our data indicate that the direct effect of ethanol on hepatic macrophages plays a major role in reducing the bactericidal activity of hepatic RES, although alterations of serum factors may contribute to an ineffective preparation of bacteria for intracellular killing.

Animals↗

PubMed1981

[Effect of levamisole on changes in the of hepatic RES induced by chronic ethanol poisoning].

Hepatic RES is depressed in chronic alcholic intoxication and we have previously observed a significant reduction of killing of E.coli by the Kupffer cells of the isolated rat liver. In the present study rats treated with ethanol for 3 weeks, were given levamisole and then the clearance of E. coli, by the isolated liver, was followed. Levamisole 10mg/kg i.p. for 3 days, restored the depression of intracellular killing induced by ethanol. At the dosage of 2,5 mg/kg of levamisole this effect was not present. Changes of humoral factors were not involved in the phenomenon because sera from untreated anaimals were present in the perfusate for all sets of experiments.

Animals↗

PubMed1981

Treatment of chronic active hepatitis (CAH): a retrospective review of 130 patients.

The authors review the course of disease in 130 patients (87 HBsAg-positive and 43 HBsAg-negative) with chronic active hepatitis (CAH) observed in the last six years. Patients were treated with prednisone (36 HBsAg-positive an 8 HBsAg-negative), azathioprine (7 HBsAg-positive and 12 HBsAg-negative) or a combination of prednisone and azathioprine (23 HBsAg-positive and 14 HBsAg-negative), or remained untreated (21 HBsAg-positive and 9 HBsAg-negative). Among HBsAg-positive patients improvement was observed in 54% of the 66 patients treated, and in none of the 21 untreated patients (P less than 0.001). Treatment did not modify the course of the disease in HBsAg-negative patients with CAH; this is probably related either to the small number of patients in each treatment group, or to geographical differences. Furthermore treatment was not effective in patients older than 40 years, whether HBsAg-positive or HBsAg-negative. Three out of 87 HBsAg-positive patients, and two out of the 43 HBsAg-negative patients had died by the end of the observation period irrespective of treatment. Full remission with clearance of HBsAg was observed only in one patient after 4 years of treatment with steroids.

Adolescent↗

PubMed1980

[Hepatic clearance of Escherichia coli during chronic alcoholic intoxication].

The effects of chronic ethanolic intoxication on the phagocytic and bactericidal activity of the hepatic reticuloendothelial system against viable Escherichia coli were examined using be in vitro perfused at liver system. Livers were isolated from control and ethanol treated animals (3 week) and perfused with a red cell-free medium containing 4% homologous serum from control rats. After addition of E. coli (2 X 10(7) cell/ml) to the perfusing medium hepatic clearance of bacteria was measured by determining the recovery of viable cells in the perfusate, liver and bile after 30 min experimental time. Livers from ethanol treated animal showed a slightly lower phagocytic activity respect control animals, but were not able to kill phagocytized bacteria (20% intraphagocytic killing occurred in control livers). Our date suggest that the higher susceptibility toward infections with gram negative bacteria during chronic ethanol intoxication might be mediated by a impairment of functional activity of hepatic macrophages which may be independent of changes in serum opsonins.

Animals↗

PubMed1980

Enhanced phagocytosis and bactericidal activity of hepatic reticuloendothelial system during endotoxin tolerance.

The effects of tolerance to Escherichia coli endotoxin on the phagocytic and bactericidal activity of the hepatic reticuloendothelial system against viable E. coli were examined using ex vivo perfused rat livers. Livers were isolated from control and endotoxin-tolerant rats and perfused with a medium containing 5% homologous serum from either control or tolerant rats. After the addition of the E. coli (2 x 10(7) cells per ml) to the perfusate, the hepatic clearance of the bacteria was followed for 30 min. The highest activation of the hepatic reticuloendothelial system was observed when serum from tolerant animals was added to the perfusate. Under these conditions phagocytosis was 47% (12% in controls), and 37 to 38% of the bacteria were killed (5% in controls). This activation was less when livers obtained from tolerant rats were perfused with serum from controls or with saline only. The data suggests that, during endotoxin tolerance, humoral factors play an important role in the activation of the hepatic reticulendothelial system, although a direct stimulation of Kupffer cells also occurs. The enhancement of phagocytosis by tolerant serum did not require the presence of homologous antibodies and involved the activation of the alternative complement pathway, since it was lost after removal of factor B activity. On the other hand, stimulation of intracellular killing required both complement and specific antibodies. The data suggest a role of endotoxin in the activation of humoral and cellular mechanisms involved in the host resistance to gram-negative bacterial infection.

Animals↗