Search PubMed⌕ Search

Biomedical subjects

B I Asmar

Publications and source records attributed to B I Asmar.

32 records · Page 2Linked to original sources
PubMed1991

Immunogenicity and reactogenicity of Haemophilus influenzae type b-meningococcus group B outer membrane protein conjugate vaccine in children 2-60 months of age.

Haemophilus influenzae b - Neisseria meningitidis group B outer membrane protein conjugate vaccine (Hib-OMP) was given to 571 children 2-60 months of age. Two doses of Hib-OMP were given, 2 months apart, to 2-11 month old infants, and a single dose to children 12-60 month old. Sera were obtained from a subset of vaccinees at each immunization, and at follow-up 1 month and 1 year after immunization. Geometric mean antibody concentration (micrograms/ml) before and after full immunization were respectively 0.111 and 3.549 for 2-3 month old, 0.108 and 5.048 for 4-5 month old, 0.082 and 6.933 for 6-11 month old; they were 0.103 and 3.500 for 12-17 month old, 0.167 and 7.791 for 18-23 month old and 0.243 and 12.781 for children greater than or equal to 24 months. Detectable antibody (greater than or equal to 0.125 micrograms/ml) failed to develop in 2/399 (0.5%) after primary immunization, and 12/252 (4.8%) lost detectable antibody 1 year later. Six of these 12 infants were less than 12 month old. The vaccine was immunogenic as early as 3-5 months of age. The need for booster immunization needs to be assessed.

Age Factors↗
PubMed1988

Antagonistic effect of chloramphenicol in combination with cefotaxime or ceftriaxone.

We evaluated the in vitro interaction at clinically attainable concentrations of cefotaxime and ceftriaxone with chloramphenicol against 26 clinical isolates of gram-negative rods, group B streptococci, and Staphylococcus aureus. Cefotaxime and ceftriaxone were bactericidal against all 26 organisms (MBC, 0.03 to 4 micrograms/ml). Chloramphenicol was bacteriostatic against 24 organisms (MBC, greater than or equal to 32 micrograms/ml) and bactericidal against two Escherichia coli isolates (MBC, 8 micrograms/ml). Checkerboard testing showed chloramphenicol to be antagonistic to the bactericidal activity of cefotaxime and ceftriaxone for all 24 bacteria for which chloramphenicol was bacteriostatic. Time kill curves for selected strains of E. coli and group B streptococci for which chloramphenicol was bacteriostatic showed antagonism of chloramphenicol to both cephalosporins. The combination of chloramphenicol with either cephalosporin was antagonistic in cases in which chloramphenicol was bacteriostatic against the above organisms and should be avoided in the treatment of infections caused by such organisms if bactericidal therapy is desired.

Bacteria↗
PubMed1987

Neonatal retropharyngeal cellulitis due to group B streptococcus.

Two neonates who presented with histories of poor feeding, irritability and noisy breathing had group B streptococcal (GBS) bacteremia and retropharyngeal cellulitis. One infant also had submandibular cellulitis. Retropharyngeal cellulitis has not been recognized as a manifestation of GBS disease. Evaluation of the upper airway should be part of the workup of any sick infant with noisy breathing and/or grunting. Retropharyngeal tissue enlargement may be an early indicator of GBS disease.

Cellulitis↗
PubMed1987

Escherichia coli cellulitis in children with idiopathic nephrotic syndrome.

Although Streptococcus pneumoniae is traditionally considered the preponderant bacterial pathogen in children with nephrotic syndrome, recent data suggest an increase of infections with encapsulated gram-negative organisms. We report two children with idiopathic nephrotic syndrome in relapse who developed spontaneous Escherichia coli cellulitis. The organism was recovered from the cellulitis tissue aspirate of one, and from the blood of the other. Both patients responded to appropriate antibiotic therapy. Initial treatment of sepsis, peritonitis or spontaneous cellulitis in nephrotic patients should include broad spectrum antibiotic coverage pending results of appropriate cultures.

Adolescent↗
PubMed1985

Cefotaxime diffusion into cerebrospinal fluid of children with meningitis.

Cefotaxime diffused consistently and in therapeutic levels into the cerebrospinal fluid (CSF) of 13 children successfully treated for bacterial meningitis. CSF cefotaxime levels early (6.0 micrograms/ml) and late (1.2 micrograms/ml) in treatment were severalfold the MBCs for the infecting organisms. After a single 40-mg/kg dose to each of five infants with ventriculostomies, mean CSF levels of cefotaxime were 6.4, 5.7, and 4.5 micrograms/ml at 2, 4, and 6 h, respectively.

Cefotaxime↗
PubMed1983

Pharmacokinetics of intravenously administered piperacillin in preadolescent children.

We studied the pharmacokinetics of piperacillin in 37 preadolescent children (mean age 52 months, range 1 month to 11 years) after 50 mg/kg IV doses. Pharmacokinetic parameters were determined after the initial dose in 18 instances and after subsequent doses in 32 instances. There were no significant differences between the initial doses and the subsequent doses in the plasma piperacillin concentrations at comparable times, the elimination rate constants, the elimination-phase plasma half-lives, the total body clearances, the apparent volumes of distribution, or the areas under the concentration curves. At the end of a 30-minute infusion of the drug, the plasma concentration was 166.2 +/- 42.2 mg/L (mean +/- SD) and ranged from 91.6 to 268.3 mg/L. The mean half-life was 31.0 +/- 9.4 minutes. The half-life of piperacillin in children 1 to 6 months of age (47.2 minutes) was significantly longer than in older children (28.8 minutes) (P less than 0.05). Likewise, the total body clearance of the drug in the younger age group (71.7 ml/min/m2) was significantly lower than in the older children (130.8 ml/min/m2) (P less than 0.05). The mean renal clearance of the drug was only 63% (range 39% to 85%) of the total body clearance, suggesting a variable but substantial nonrenal route of elimination. The intravenous administration of 50 mg/kg piperacillin every four hours results in adequate plasma concentrations for the treatment of most infections caused by gram-negative and gram-positive organisms.

Bacterial Infections↗
PubMed1981

Hematologic abnormalities after oral trimethoprim-sulfamethoxazole therapy in children.

The development of hematologic abnormalities was prospectively evaluated in 50 children treated for ten days each with oral trimethoprim-sulfamethoxazole and compared with a control group of 20 children with similar infections treated with amoxicillin trihydrate. Neutropenia (polymorphonuclear neutrophilic leukocyte counts, less than or equal to 1,500/cu mm) developed in 17 (34%) of the 50 children treated with trimethoprim-sulfamethoxazole compared with one (5%) in the control group of 20 children (P less than 0.001). Thrombocytopenia (platelet count, less than 150,000/cu mm) developed in six (12%) of the children treated with trimethoprim-sulfamethoxazole, but it did not develop in any of the amoxicillin-treated children (P less than .01). Neutropenia occurred mostly during the first week of treatment and lasted a mean of 8.9 days. Thrombocytopenia was noted between the seventh and 16th day (mean, 10.3 days) and lasted a mean of 12.7 days. Both side effects resolved spontaneously without ill effects. Children treated with oral trimethoprim-sulfamethoxazole should be followed up with biweekly leukocyte and platelet counts, and treatment should be discontinued if severe neutropenia or thrombocytopenia develops.

Amoxicillin↗
PubMed1978

Pneumococcal pneumonia with pneumatocele formation.

Two infants had pneumococcal pneumonia and bacteremia, complicated by pneumatocele formation. The pneumatoceles appeared during the recovery phase and were indistinguishable from those associated with staphylococcal pneumonia. Complete resolution occurred in both patients. Pneumatoceles occur in pneumonias caused by varied agents; therefore, determination of the cause is imperative for appropriate therapy.

Cysts↗
PubMed1978

Hemophilus influenzae type b pneumonia in 43 children.

Using positive blood, lung, or pleural fluid cultures as definitive criteria for bacterial infection, 43 examples of Hemophilus influenzae type b pneumonia were identified in a 43-month period. The mean age of the patients was 26 months; 12% were older than 5 years of age. Associated infections were found in 34 patients and included upper respiratory infections, otitis media, epiglottitis, and meningitis. Positive nasopharyngeal cultures were observed in only 33%. Radiologically, segmental or lobar infiltrates accounted for 85% of the pneumonias. In two cases, death was attributed to the pneumonia alone. Treatment with penicillin G or ampicillin was equally effective. Our data suggest that H. influenzae pneumonia is commonly a serious infection that cannot be distinguished clinically or radiologically from other pneumonias.

Ampicillin↗
PubMed1978

Violaceous discoloration in pneumococcal cellulitis.

Two patients with periobital cellulitis, one of whom also had buccal cellulitis, had violaceous discoloration of the skin. Blood cultures from both patients yielded Streptococcus pneumoniae. Therefore, pneumococci should be considered, in addition to Haemophilus influenzae, as possible causes of cellulitis with violaceous or bluish-red discoloration.

Cellulitis↗
PubMedDate not supplied

Ampicillin-chloramphenicol interaction against enteric Gram-negative organisms.

Because two children with Salmonella osteomyelitis responded differently to a combination of ampicillin and chloramphenicol, we investigated the activity of each antibiotic and the combination against 21 enteric organisms including Salmonella sp. and other Gram-negative bacilli. Ampicillin was bactericidal against all 21 organisms (minimal bactericidal concentration (MBC) range, 0.25 to 16 micrograms/ml). Chloramphenicol was bactericidal against 5 (MBC range, 2 to 16 micrograms/ml) and bacteriostatic against 16 (MBC, greater than or equal to 64 micrograms/ml). Fractional lethal indices indicated that chloramphenicol and ampicillin were antagonistic (fractional lethal concentration, greater than 1.2) against all 16 bacteria for which chloramphenicol was bacteriostatic, and the ampicillin MBC increased from a mean of 2.2 micrograms/ml to 37.2 micrograms/ml. The two antibiotics were synergistic (fractional lethal concentration, less than 0.8) against the five organisms for which chloramphenicol was bactericidal, and the ampicillin MBC was lowered from a mean of 3.0 micrograms/ml to 0.4 micrograms/ml. Our data indicate that the combination of ampicillin and chloramphenicol can be synergistic or antagonistic against Gram-negative enteric bacteria depending on whether chloramphenicol is bactericidal or bacteriostatic against the specific organism.

Ampicillin↗