Search PubMed⌕ Search

Biomedical subjects

M I Marks

Publications and source records attributed to M I Marks.

At least 145 records · Page 8Linked to original sources

Serial 67Ga-citrate imaging during treatment of acute osteomyelitis in childhood.

To test the hypothesis that abnormalities on 67Ga-citrate scans parallel the clinical course of acute osteomyelitis and revert to normal with successful antibiotic therapy, serial scans were performed in ten children. Scans improved markedly within the first two to four weeks of treatment, but abnormalities persisted at six or more weeks in over 50% of the cases, despite complete clinical resolutions of disease.

Acute Disease↗

Clinico-pharmacological studies of sisomicin in ill children.

Sisomicin, at 4.5 mg/kg per day, was prescribed for the therapy of serious bacterial infections of hospitalized infants, children, and adolescents. Eleven children received full treatment courses, with 10 clinical and 9 bacteriological cures. Three patients with underlying disease (two cystic fibrosis and one aplastic anemia) accounted for the failures. Mean half-life was 98.3 min (range, 26.1 to 159.3), and peak serum concentrations 10 min after intravenous infusion were similar (5 to 6 mug/ml) on days 1, 3, and 5 of therapy. Mean urinary concentrations were 54.3 mug/ml; 31 to 47% of the drug was excreted within the 8-h dosage interval. The drug was tolerated well by all patients; however, one patient, receiving the longest duration of therapy (26 days), developed reversible nephrotoxicity.

Adolescent↗

In vitro susceptibility of Haemophilus influenzae to sulfamethoxazole-trimethoprim and cefaclor, cephalexin, and cephradine.

Sulfamethoxazole-trimethoprim and three oral cephalosporins, cefaclor, cephalexin, and cephradine, were evaluated in vitro as possible alternatives to chloramphenicol in the treatment of non-central nervous system infections due to ampicillin-resistant Haemophilus influenzae. Sixty-four isolates of H. influenzae, including 31 beta-lactamase-positive strains, were tested by the agar dilution method. All strains were inhibited by 0.78/0.039 mug sulfamethoxazole-trimethoprim per ml and by 0.78 mug of chloramphenicol per ml. At 6.25 mug/ml, 100, 11, and 3% of all strains were inhibited by cefaclor, cephalexin, and cephradine, respectively. Thus, on the basis of drug concentrations presumably achievable in serum, 100% of strains were susceptible to sulfamethoxazole-trimethoprim, chloramphenicol, and cefaclor. However, a considerable inoculum effect was noted with both beta-lactamase-positive and -negative strains, when tested with sulfamethoxazole-trimethoprim; the minimal inhibitory concentrations of cefaclor were only slightly affected. Also, synergistic effects of sulfamethoxazole-trimethoprim, sulfamethoxazole-erythromycin, and sulfamethoxazole-cefaclor were seen when combinations were tested against both beta-lactamase-positive and -negative strains, as determined by minimal inhibitory concentrations measured by the broth dilution method and by killing curve analyses. These results support further evaluation of these combinations and of cefaclor alone for the treatment of non-central nervous system infections due to H. influenzae.

Cephalosporins↗

Serum standards for the bioassay of aminoglycosides in cerebrospinal fluid.

Four diluents were compared as reference standards for the assay of gentamicin in cerebrospinal fluid (CSF): human CSF, human serum, distilled water, and 150 mmol NaCl/4.5 mmol CaCl2. Standards prepared in pooled human serum were the best alternative to CSF for the assay of gentamicin and were also useful for the assay of tobramycin, netilmicin, amikacin, and sisomicin. The pH (6.0-9.8) of CSF did not alter the results of the assay.

Aminoglycosides↗

In vitro activity of netilmicin (SCH 20569) against bacterial isolates from ill children.

A new aminoglycoside antibiotic, netilmicin, was tested against 306 clinical isolates from ill children and compared with sisomicin and gentamicin. Activity against Enterobacteriaceae was similar to that of gentamicin but less than that of sisomicin. Two gentamicin-resistant strains of Enterobacteriaceae (Klebsiella, MIC 6.25 microgram/ml, Escherichia coli, MIC 12.5 microgram/ml) were susceptible to netilimicin (MIC 3.12 microgram/ml). Netilmicin was ineffective against almost all strains of Pseudomonas but active against the majority of strains of Staphylococcus, Neisseria meningitidis and Haemophilus influenzae tested. Disc diffusion sensitivity results correlated in general with the agar dilution test. Netilmicin had little activity against Pseudomonas but may be useful in the treatment of infections due to gentamicin-resistant Enterobacteriaceae.

Aminoglycosides↗

Adverse reactions to 1975 bivalent influenza vaccine in children.

A questionnaire survey was undertaken to investigate incidence and types of reactions to a bivalent, zonally purified, killed influenza vaccine administered to 155 children aged 1 to 18 years in 1975. Local or systemic reactions or both occurred in 42 children (27%). However, these reactions were not considered serious and should not constitute a major drawback to future influenza programs in children under 3 years of age.

Adolescent↗

Pneumococcal meningitis in children.

We review the clinical and laboratory features of 79 children with 83 episodes of pneumococcal meningitis over a 26-year period. The onset of illness was often severe, with convulsions occurring in 31% of the patients. The mortality was 10.8% and all deaths occurred in patients younger than 1 year of age; the death rate has dropped from 19% in the 1948 to 1962 era to 3% from 1963 to 1973. The association of pneumonia with meningitis, the presence of hypoglycorrhachia, and an increased CSF protein concentration were associated with a poor prognosis; bacteremia and convulsions were also more common in the fetal cases. Neurologic sequelae including recurrent meningitis, deafness, hydrocephalus, convulsions, and retardation were present in 56% of the patients observed. Findings from EEGs did not correlate well with the clinical picture during the acute or convalescent stage of the illness. Despite accurate diagnosis, prompt therapy, and a decrease in the mortality in the past decade, pneumococcal meningitis in children is still often associated with a serious outcome.

Adolescent↗

Successful treatment of Candida meningitis with amphotericin B and 5-fluorocytosine in combination.

The combined use of amphotericin B and 5-fluorocytosine in the treatment of two children with Candida albicans meningitis is described. Therapy consisted of nine to 13 days of iv amphotericin B, combined with, or followed by six to nine weeks of oral 5-FC. Each organism was sensitive to 5-FC before starting therapy. Resistance did not develop during therapy. CSF administration was not necessary and toxic reactions were minimal and transient; neither patient has suffered a recurrence four years and 14 months, respectively, after discontinuance of therapy. The combination of short-term therapy with iv amphotericin B plus long-term oral 5-FC was successful in these two patients.

Amphotericin B↗

Activity of newer aminoglycosides and carbenicillin, alone and in combination, against gentamicin-resistant Pseudomonas aeruginosa.

The in vitro activity of the aminoglycoside antibiotics tobramycin, sisomicin, amikacin, gentamicin, and netilmicin (SCH 20569) were compared against 26 gentamicin-resistant isolates of Pseudomonas aeruginosa cultured from hospitalized children. Tobramycin had the greatest activity on a weight basis, followed by sisomicin, gentamicin, amikacin, and netilmicin. All isolates were resistant to achievable concentrations of netilmicin and gentamicin, but 23% were inhibited by achievable concentrations of tobramycin, 8% by amikacin, and 4% by sisomicin. The combinations carbenicillin/tobramycin, carbenicillin/sisomicin, and carbenicillin/amikacin were synergistic for 92% of strains; antagonism was not encountered. These in vitro results suggest that tobramycin, sisomicin, or amikacin in combination with carbenicillin would be the safest initial regimen in the therapy of gentamicin-resistant Pseudomonas infections pending susceptibility studies.

Amikacin↗

Reevaluation of the disk diffusion method for sulfonamide susceptibility testing of Neisseria meningitidis.

Lack of correlation between quantitative minimal inhibitory concentration (MIC) determinations and disk diffusion susceptibility tests in our laboratory prompted a study to reevaluate the use of the disk diffusion test for sulfonamide susceptibility testing of Neisseria meningitidis. One hundred and sixty-three recent clinical isolates of N. meningitidis were examined for sulfonamide susceptibility by the agar dilution and disk diffusion methods. Optimal inocula for each of the tests were determined, and thereafter all disk diffusion tests were compared with quantitative MICs as determined by the agar dilution method using sulfadiazine and an inoculum of 10(6) colony-forming units (CFU)/ml. The clearest and most reproducible zone diameters were obtained with a 10(7)-CFU/ml inoculum in the disk diffusion test. There was complete correlation between the disk zone diameters for 300-mug disks of sulfadiazine and sulfathiazole and the agar dilution test MICs. All isolates with a zone diameter of <20 mm were resistant to sulfadiazine, whereas those with zone diameters of >/=30 mm were susceptible. False susceptible and false resistant readings were obtained with 300-mug sulfisoxazole disks. These data suggest that inocula and type of sulfonamide are critical factors in the disk diffusion test for meningococcal susceptibility testing. Sulfonamide disks are not interchangeable for susceptibility testing of meningococci.

Culture Media↗