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Biomedical subjects

M I Marks

Publications and source records attributed to M I Marks.

At least 127 records · Page 7Linked to original sources
PubMed1980

Is anti-Pseudomonas therapy warranted in acute respiratory exacerbations in children with cystic fibrosis?

A controlled study was designed to clarify the indications for antibiotic therapy in children with advanced cystic fibrosis hospitalized with respiratory exacerbations. Twenty-two children with severe CF and signs of acute lower respiratory infection were randomly assigned to receive either cloxacillin or carbenicillin plus gentamicin administered intravenously for ten days. Other aspects of therapy were constant. The groups were comparable in all respects and Pseudomonas aeruginosa was the predominant sputum pathogen in most patients. Clinical improvement, chest radiograph changes, evidence of airway obstruction, and bacteriologic flora of sputum were no different regardless of the regimen used. These results suggest that the use of anti-Pseudomonas medication in these children may not always be necessary. These observations need to be confirmed by blind-controlled studies in larger numbers of patients with mild as well as severe respiratory involvement.

Carbenicillin↗
PubMed1980

Yersinia enterocolitica gastroenteritis: a prospective study of clinical, bacteriologic, and epidemiologic features.

A prospective study was performed to estimate the frequency of gastroenteritis due to Yersinia enterocolitica in Montreal children and their families. Evidence of bacterial infection was correlated with clinical features and serologic responses. YE was isolated from the stools of 181 (index cases) of 6,364 children with gastroenteritis over a 15-month period; Salmonella was isolated from 280 and Shigella from 68. Median ages were 24, 30, and 41 months, respectively. All but 18 YE isolates were biotype 4, serotype 0:3. YE was not found in the stools of 545 children without gastrointestinal symptoms. Clinical manifestations of the index cases with YE biotype 4, serotype 0:3 (n = 57) included diarrhea (98%), fever (88%), abdominal pain (64.5%), and vomiting (38.5%) with mean durations of 14, 3.9, 7.7, and 2.4 days, respectively. The duration of excretion of YE in the stool ranged from 14 to 97 days (mean 42). Spread of YE occurred in 27 of 57 families studied, involving 15 of 41 children and 19 of 117 adult contacts; approximately one-third of infected contacts developed diarrhea. Agglutination titers of greater than or equal to 200 were demonstrated in all index cases infected with serotype 0:3, with the exception of two very young infants. YE is a frequent cause of bacterial gastroenteritis in Montreal children. The illness is characterized by persistent diarrhea and abdominal pain, prolonged YE excretion in the stools, and moderate communicability.

Adolescent↗
PubMed1980

Model of neonatal meningitis caused by Escherichia coli K1 in guinea pigs.

A total of 88 neonatal guinea pigs was inoculated intranasally with a clinical isolate of Escherichia coli K1 that had been passaged once in the peritoneum of an adult guinea pig; 74 animals became bacteremic, of which 54 had meningitis, 12 hr after inoculation. Bacteremia and/or meningitis occurred consistently in repeated experiments. It was possible to obtain serial specimens of cerebrospinal fluid by cisternal puncture without killing the animals. The induction of meningitis in a predictable fashion without disrupting the blood-brain barrier and the ability to study the cerebrospinal fluid without killing the animal make this a useful model of human neonatal meningitis caused by E. coli K1.

Aminoglycosides↗
PubMed1980

Antimicrobial susceptibility testing of Streptococcus pneumoniae by micro-broth dilution.

Thirty-three clinical isolates of Streptococcus pneumoniae were tested for susceptibility to penicillin and ampicillin by a standard agar dilution method. Results were compared to those obtained using a micro-broth dilution technique in which Mueller-Hinton broth was supplemented with 5% difibrinated whole sheep blood. Among the 33 strains, 2 were resistant (minimal inhibitory concentration, 8 micrograms/ml), 10 were relatively resistant (minimal inhibitory concentration, 0.12 to 0.5 micrograms/ml), and 20 were susceptible (minimal inhibitory concentration, less than or equal to 0.06 micrograms/ml) to penicillin by both methods. Only one stain showed a two-dilutional-step difference by micro-broth and agar dilution testing resulting in categorization as relatively resistant by the former method but susceptible by the latter. A 1-microgram oxacillin disk correctly identified 11 of the 12 resistant strains. The micro-broth dilution technique is a reliable, simple method for penicillin or ampicillin susceptibility testing of pneumococci and economically feasibile to perform manually or with a semiautomated system.

Ampicillin↗
PubMed1980

Oral antibiotic therapy of skeletal infections in children.

Oral and intravenous (IV) antibiotic regimens were compared in 15 children with etiologically defined osteomyelitis and/or septic arthritis. On admission all children were started on standard IV therapy; seven were changed to oral antibiotics within 72 hours and the remaining eight continued on IV therapy for four weeks. Oral antibiotic doses were adjusted to achieve a peak serum bactericidal titer of greater than or equal to 1:8 against the patient's own pathogen. All patients were treated in hospital for four weeks; therapy continued for a minimum of six weeks or until the erythrocyte sedimentation rate (ESR) fell below 20 mm/hr. The clinical course and outcome were similar in both groups. There were no treatment failures nor any relapses during a 12-month follow-up period. This prospective study supports, with controlled data, the concept that acute skeletal infections can be safely and successfully treated with carefully monitored oral therapy.

Administration, Oral↗
PubMed1979

Meningococcal meningitis in children.

Forty-four cases of meningococcal meningitis in children at one hospital between 1971 and 1975 inclusive were studied to document the course and complications of this disease in children in the current therapeutic era. The mortality was 5%. Of the 41 survivors 76% were healthy 1 to 5 years after the episode of meningitis. Permanent severe sequelae (facial palsy, optic atrophy and ptosis) were seen in three (7%) of the survivors, and mild hearing loss, hyperactivity and nervousness were noted in seven (17%). Electroencephalography was not useful in determining management or prognosis. Both the mortality and the frequency of early and late complications among the survivors were lower than those reported from earlier studies.

Adolescent↗
PubMed1979

Penicillin-insensitive pneumococci. Case report and review.

Infections due to pneumococci with decreased susceptibility (or resistance) to penicillin have been infrequently recognized. Our experience and that of others suggest that (1) penicillin susceptibility testing of significant pneumococcal isolates should become routine; (2) penicillin may not be adequate therapy for CNS infections due to pneumococci whose penicillin minimal inhibitory concentration is greater than 0.1 microgram/ml; and (3) long-term penicillin "prophylaxis" may be inappropriate in the splenectomized patient in areas where these organisms are prevalent.

Child↗
PubMed1979

Meningococcal colonization and infection in children and their household contacts.

A bacteriologic survey was performed to estimate the prevalence and duration of meningococcal carriage in children in Montreal, Canada. Infants and children with proven meningococcal infection, or with asymptomatic meningococcal nasopharyngeal (NP) carriage, and their household contacts, were also studied to define communicability. N. meningitidis was present in 30 (2.4%) of the NP cultures from 1238 asymptomatic infants and children in this civilian population during a non-epidemic period. Meningococcal carriage was not found in 278 subjects 1--60 days of age; there was no difference in carriage rates between the sexes and between hospitalized and non-hospitalized children in all age groups. Meningococci were initially isolated from 11 of 106 household contacts of 29 ill index cases and from 15 of 104 contacts of 29 asymptomatic carriers; 35% of all contacts (index cases and carriers) were colonized by the eighth week of surveillance. Duration of NP carriage was longer (mean 15.2 weeks) in disease-free families than in families of ill patients (mean 5.5 weeks). Serogroups B and C were most commonly isolated from both ill and asymptomatic subjects. Resistance to sulfadiazine (MIC greater than or equal to mg/100 ml) was present in 6.5% and 39.4% of group B and group C strains, respectively. Although chemoprophylaxis was not used, there were no secondary cases among the 29 families of index cases.

Adolescent↗
PubMed1979

Efficacy of cold enrichment techniques for recovery of Yersinia enterocolitica from human stools.

Stool specimens from children with gastroenteritis and their household contacts were cultured for Yersinia enterocolitica by direct plating onto routine laboratory media. These stools were also inoculated into phosphate-buffered saline and subcultured to the same media after 1 day or 3 weeks of incubation at 4 degrees C. Y. enterocolitica was isolated from 174 index cases and 34 household contacts. One hundred eighty-one isolates were of serotype O:3, and the remaining 21 belonged to other serotypes. Eighty-one percent (147/181) of O:3 isolates were recovered by direct plating, and 6.1% (11/181) and 13% (23/181) were recovered by 1-day and 3-week cold enrichment, respectively. For other serotypes, 26% (7/27), 0%, and 74% (20/27) were isolated by direct plating, 1-day cold enrichment, and 3-week cold enrichment, respectively. The efficacy of the cold enrichment for the patients were still symptomatic, 94 and 6% of Y. enterocolitica were identified by direct plating and cold enrichment, respectively. Isolation rates were 66% by direct plating and 34% by cold enrichment when stools were obtained from asymptomatic carriers or from those convalescing from Y. enterocolitica gastroenteritis. These results indicate that the cold enrichment methods increase the sensitivity of Y. entercolitica culture methods considerably in convalescent and asymptomatic subjects but only minimally in patients with diarrhea caused by serotype O:3.

Bacteriological Techniques↗
PubMed1978

Evaluation of three antibiotic programs in newborn infants.

Emergence of gram-negative bacteria resistnant to a number of antibiotics in intensive care nurseries for neonates emphasizes the need for alternatives in antibiotic combinations. One commonly used combination, gentamicin-ampicillin, and two newer combinations, tobramycin-cephalothin and amikacinampicillin, were evaluated prospectively in 60 newborns in such a nursery. Subjects were randomly assigned to one of the above therapy groups. Dosages in mg/kg.d were 100 for ampicillin and cephalothin, 6 for gentamicin and tobramycin and 15 for amikacin. Aminoglycoside serum concentrations, clinical tolerance and toxicity were monitored. Aminoglycoside concentrations after intravenous administration of the drugs were within the expected range (gentamicin and tobramycin 4 to 6 microgram/mL and amikacin 15 to 20 microgram/mL). There was no hematologic, renal or hepatic toxicity attributable to antibiotic therapy and the combinations were tolerated equally; no bilirubin displacement was detected in vitro or in vivo.

Amikacin↗
PubMed1978

Evaluation of amoxicillin therapy in ill children.

Ampicillin and amoxicillin were evaluated in 37 ill children. Detailed pharmacokinetic studies in 27 of these children demonstrated an advantage in oral absorption of amoxicillin over ampicillin at dosages of both 12.5 and 25 mg/kg per dose. Individual variation was great for both drugs. No sequence effect was noted for patients receiving ampicillin before either ampicillin or amoxicillin. Amoxicillin was tolerated well by the majority of patients, and the drug was not discontinued because of side effects in any patient. No toxicities were noted for amoxicillin in any of the 20 patients studied for abnormalities in hematologic hepatic, and renal functions. Pharmacokinetics, clinical efficacy, tolerance, and toxicity studies support the clinical usage of amoxicillin in pediatric infectious diseases. However, comparative, controlled clinicalinvestigations are needed to better define the clinical advantages of this drug over ampicillin.

Adolescent↗