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Biomedical subjects

M I Marks

Publications and source records attributed to M I Marks.

At least 37 records · Page 2Linked to original sources
PubMed1990

In vitro activity of E-1040, a 3-substituted cephalosporin, against pathogens from cystic fibrosis sputum.

On the basis of preliminary in vitro data, we evaluated E-1040, a new cephalosporin, against 188 cystic fibrosis (CF) sputum isolates obtained from 26 CF centers in the United States. These isolates included mucoid and nonmucoid Pseudomonas aeruginosa, Pseudomonas cepacia, Staphylococcus aureus, Haemophilus influenzae, and Escherichia coli. In addition to MICs measured under standard conditions, selected isolates were tested at various pH values, inoculum sizes, and diluent (CF serum and sputum) conditions. E-1040 activities (MICs for 50 and 90% of the strains) against the isolates were as follows: P. aeruginosa (mucoid and nonmucoid), 1 and 4 micrograms/ml; P. cepacia, 4 and 16 micrograms/ml; S. aureus, 8 and 8 micrograms/ml; H. influenzae, 1 and 4 micrograms/ml; and E. coli, less than or equal to 0.12 and less than or equal to 0.12 microgram/ml. E-1040 activity against mucoid P. aeruginosa was 4-fold greater than that of aztreonam, 16-fold greater than that of ceftazidime, and 32-fold greater than that of piperacillin. E-1040 was similar to other broad-spectrum cephalosporins against S. aureus, H. influenzae, and E. coli. Bactericidal activity was less than or equal to 1 dilution of MIC for 88% of the strains, although kinetic studies with mucoid strains of P. aeruginosa demonstrated effective killing only at eight times the MIC. Variations in pH from 5 to 8, in inoculum size from 10(3) to 10(7) CFU/ml, and in diluent (CF serum or CF sputum) did not affect E-1040 activity.

Bacteria↗
PubMed1987

Pharmacokinetics of two dosage regimens of ciprofloxacin during a two-week therapeutic trial in patients with cystic fibrosis.

Twenty-nine adult patients with cystic fibrosis received 750 or 1,000 mg of ciprofloxacin orally every 12 hours for two weeks. Pharmacokinetic data were collected on Days 1, 7, and 14. Pharmacokinetic analyses revealed minor differences between the dosage regimens, and results were similar on the first, seventh, and last day of therapy. Means for peak serum concentration (3.1 to 5.0 micrograms/ml), elimination half-life (4.8 to 5.3 hours), area under the time-concentration curve, and serum clearance (36.8 to 44.5 liter/hour) were similar to previously reported results for patients without cystic fibrosis. Sputum concentrations approximated serum values.

Adult↗
PubMed1987

Randomized study of two dosage regimens of ciprofloxacin for treating chronic bronchopulmonary infection in patients with cystic fibrosis.

Twenty-nine adult patients with cystic fibrosis who had chronic bronchopulmonary infection were randomly assigned to receive 750 or 1,000 mg of oral ciprofloxacin every 12 hours for two weeks. Assessments for efficacy and safety were made on treatment Days 7 and 14 and one week following completion of therapy, and pharmacokinetic data were collected on Days 1, 7, and 14. Fifteen of 28 evaluable patients showed clinical improvement, and none had clinical deterioration. The higher dosage of ciprofloxacin did not enhance the clinical response. Statistically significant, stepwise changes in clinical scores, pulmonary function, and sputum concentrations of Pseudomonas aeruginosa and Staphylococcus aureus were noted, but regression toward initial values occurred by one week after treatment. Although all P. aeruginosa isolates were initially inhibited by 2 mg/liter of ciprofloxacin or less, 45 and 35 percent of isolates were resistant after 14 days of therapy and one week later, respectively. Outpatient oral ciprofloxacin therapy was commonly associated with clinical improvement in adult patients with cystic fibrosis who have chronic bronchopulmonary infection, regardless of the emergence of resistant P. aeruginosa, and adverse reactions were infrequent. Further studies must delineate the long-term consequences of the frequent emergence of bacterial resistance.

Adolescent↗
PubMed1987

Soft-tissue infections caused by Mycobacterium fortuitum complex following penetrating injury.

Soft-tissue infections caused by rapidly growing mycobacteria may follow penetrating trauma. We present four immunologically normal patients in whom soft-tissue infections with Mycobacterium fortuitum developed after they stepped on nails. Their presentations were clinically indistinguishable from puncture wound infections caused by Pseudomonas aeruginosa and Staphylococcus aureus. The acid-fast organisms grew on standard bacteriologic media within three to five days. Speciation and antimicrobial susceptibility testing was performed. The primary mode of therapy was surgical; adjunctive antimicrobial therapy is recommended only for extensive or chronic infections and in immunocompromised hosts. All four of our patients had good outcomes after therapy.

Child↗
PubMed1987

Enoxacin pharmacokinetics and efficacy in CF-1 mice.

Mean peak enoxacin serum concentrations in nonfasted CF-1 mice following a single 50, 100, or 200 mg/kg oral dose were 2.0, 4.0 and 11.4 mg/l, respectively, with proportional increases in area under the serum concentration curves. Oral enoxacin was significantly more effective than tobramycin or dicloxacillin in experimental Pseudomonas aeruginosa and Staphylococcus aureus infections respectively. Enoxacin was as effective as tobramycin against P. cepacia and Escherichia coli infections. Enoxacin may be useful as an oral antimicrobial for the treatment of selected systemic bacterial infections.

Analysis of Variance↗
PubMed1987

Aerosolized ribavirin treatment of respiratory syncytial virus infection in infants hospitalized during an epidemic.

Thirty-three infants with predisposing conditions and/or severely symptomatic with respiratory syncytial virus (RSV) infection were treated with aerosolized ribavirin during a 12-week period at Oklahoma Children's Memorial Hospital. These patients were compared with 97 untreated patients with RSV infection hospitalized during the same epidemic. Despite preconditions which selected for a more seriously ill treatment group, patients who received ribavirin showed prompter resolution of the illness than did untreated controls. Greatest clinical improvement in treated patients occurred between the first and second days of ribavirin therapy; mean ribavirin treatment duration was 4.5 days. Ten of 22 ribavirin-treated patients continued to excrete RSV after conclusion of antiviral therapy. No adverse hematologic, renal or metabolic effects occurred with ribavirin therapy. Our experience with ribavirin therapy during a major epidemic confirms and extends the results of previous controlled evaluations demonstrating this treatment safe and effective in high risk and seriously ill infants with RSV bronchiolitis and bronchopneumonia.

Administration, Inhalation↗
PubMed1987

Synergistic action of amphotericin B and rifampin against Rhizopus species.

A 16-year-old diabetic patient developed Rhizopus pneumonia and was initially treated with amphotericin B for 7 days. Because of clinical deterioration of the patient, rifampin was added empirically. The patient improved clinically, and lung tissue removed surgically 8 weeks later showed no fungal elements by histopathological studies or by culture. An in vitro study of amphotericin B alone and in combination with rifampin against the isolate from the patient and 11 additional isolates of Rhizopus spp. was designed. The activity of amphotericin B in the presence of rifampin (10 or 5 micrograms/ml) increased fourfold against 9 of 10 clinical and 1 of 2 environmental isolates. Amphotericin B activity in the presence of 2 micrograms of rifampin per ml increased fourfold against 6 of 10 clinical isolates and increased twofold against an additional 3 clinical isolates. Amphotericin B in the presence of 1 microgram of rifampin per ml inhibited 9 of 10 isolates at a concentration of one-half the MIC of amphotericin B alone. These findings were confirmed by dose-response curves calculated from fungal dry weight determinations of Rhizopus spp. incubated in serial dilutions of amphotericin B combined with rifampin. These observations demonstrate in vitro, and possibly in vivo, synergy between amphotericin B and rifampin against Rhizopus spp.

Adolescent↗
PubMed1987

In vitro activity of BMY-28100 against common isolates from pediatric infections.

The antibacterial activity of BMY-28100, a new oral cephalosporin, was measured against 300 bacterial isolates from pediatric infections by standard agar dilution methodology. The effect of inoculum size on activity was also assessed. BMY-28100 was more active than cephalexin or cefaclor against all bacterial species tested.

Bacteria↗
PubMed1987

Pulmonary infections in children with cystic fibrosis.

Bronchopulmonary infections continue to be the major determinant of morbidity and mortality in patients with cystic fibrosis (CF). The basic pathogenesis of disease includes abnormal secretions and impaired mucociliary clearance. Colonization of the tracheobronchial tract with bacteria is then associated with a cycle of infection, inflammation and airway obstruction eventually leading to respiratory insufficiency. Early clinical features include persistent cough and failure to thrive. Hyperinflation and bronchial thickening are early radiographic changes suggestive of CF. Staphylococcus aureus is commonly the initial respiratory pathogen. Subsequently, Hemophilus influenzae and Pseudomonas aeruginosa colonize the respiratory tract. In addition, respiratory viruses and other pathogens such as Legionella and mycoplasma are implicated in the etiology of pulmonary infections. The culture of respiratory secretions such as sputum are important guidelines to the etiology of pulmonary infection in CF. The laboratory must be aware of the pathogens that are typical of this disease and use appropriate techniques and media. In large part, advances in treatment in CF over the past two decades are due to the availability of increasingly potent antibiotic agents. However, effective treatment must be multifaceted and include a variety of nonantimicrobial therapies. Different approaches to the antibiotic therapy of pulmonary infection in CF, including prevention, suppression, and definitive treatment are discussed. In addition to traditional antibiotic therapy, a variety of newer methods of therapy in CF are discussed. These include oral antipseudomonal antibiotics, corticosteroid therapy, aerosolized antibiotics, and continuous antimicrobial prophylaxis.

Anti-Bacterial Agents↗