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Biomedical subjects

H Mattie

Publications and source records attributed to H Mattie.

141 records · Page 8Linked to original sources
PubMedDate not supplied

Quantitative determination of the effect of granulocytes on the course of experimental infections during antibiotic treatment.

We are presenting a quantitative determination of the effect of granulocytes, monocytes and lymphocytes on the course of infection during antibiotic treatment. The animal model was a short-term infection of the thigh muscle in normal or irradiated mice. Two kinds of antibiotics were used: tobramycin for Pseudomonas aeruginosa infections and ampicillin for Escherichia coli infections. The number of granulocytes was changed by irradiating the mice before they were infected. The dose-effect relations for both combinations of bacteria and antibiotics were determined on various days after irradiation. Analysis of the results shows that the effect of an antibiotic was predominantly potentiated by granulocytes. This means that under the conditions of granulopenia, the dose of an antibiotic must be increased to obtain the same antibacterial effect. The present results indicate that the interrelation between host factors, bacterial proliferation and antibiotic treatment can be quantitated and may offer a useful model for screening antimicrobial drugs before they are clinically applied.

Agranulocytosis↗
PubMedDate not supplied

Brain abscess due to Streptobacillus moniliformis and Actinobacterium meyerii.

This paper deals with a case of brain abscess due to Streptobacillus moniliformis (the cause of the streptobacillary type of rat-bite fever) and Actinobacterium meyerii. Brain abscesses due to these micro-organisms are rare. The possible causative mechanisms in this particular case and the diagnostic and therapeutic management of brain abscesses in general are discussed.

Actinomycosis↗
PubMedDate not supplied

Limited value of acyclovir in the treatment of uncomplicated herpes zoster: a placebo-controlled study.

The effect of intravenous acyclovir (at a dosage of 30 mg/kg per day for five days) on uncomplicated herpes zoster was investigated in 51 patients in a double-blind study. Although existing herpes zoster lesions tended to heal more rapidly and new lesions ceased to appear somewhat earlier in the acyclovir group, these differences were not statistically significant. During treatment, patients on acyclovir had significantly lower pain scores than placebo-treated patients. At follow-up, however, there was no difference between the two groups. Complications of herpes zoster occurred only in the placebo groups (generalization in two and keratitis in two cases). With the possible exception of trigeminal zoster or severe pain, acyclovir seems to offer little benefit for immunocompetent patients with herpes zoster.

Acyclovir↗
PubMedDate not supplied

A multicentre, randomized comparative study of 500 mg versus 1,000 mg ceftazidime t.d.s. for treatment on gram-negative infections.

A multicentre, randomized study was performed to compare the clinical and bacteriological efficacy of 500 mg ceftazidime i.v. t.d.s. with 1,000 mg ceftazidime i.v. t.d.s. for treatment of hospitalised, non-compromised patients with gram-negative infections. The study was conducted in ten hospitals in The Netherlands. Hospitalised patients with a suspected gram-negative lower respiratory tract infection, complicated urinary tract infection or septicaemia were included. Excluded were patients with neutropenia, limited life expectancy, or severe renal insufficiency as well as those on antibiotics in the 48 h prior to entry. Ceftazidime was administered via an intravenous infusion every 8 h. For patients with moderately impaired renal function the frequency was reduced to 12 h. Treatment was continued for as long as clinically indicated. Clinical response (cure, improvement or failure) and bacteriological response (elimination, persistence or non-evaluable) were assessed primarily by the investigator. Final assessments were made by a panel of experts without prior knowledge. In total 127 patients were randomized, 64 patients to the 500 mg group and 63 to the 1,000 mg group; 47 patients were excluded from evaluation, usually due to an incorrect diagnosis prior to randomization. Ultimately 37 patients of the 500 mg group and 43 patients of the 1,000 mg group were available for evaluation. Between these two groups of evaluable patients there were no significant differences in baseline characteristics, types of infection, isolated bacterial pathogens or treatment characteristics.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Kinetics of antimicrobial action.

To better quantify the relative antibacterial activity of beta-lactam antibiotics in vitro, mathematical descriptions of bacterial growth were developed. Growth curves for the initial 2-to 4-hr period of exposure to antibiotic can be expressed as quadratic functions of time. Moreover, the rate of change of growth (a) shows a linear dependence on the logarithm of the antibiotic concentration. For some drug-organism interactions, the initial growth rate (k0) is also a concentration-dependent variable. This mathematical quantitation of the antibacterial action of a drug in vitro covers a range of concentrations above and below its minimal inhibitory concentration. The slope of the regression line of a on log concentration may vary for different microorganisms and antibiotics. However, several analogues yield parallel concentration-effect slopes, a circumstance allowing for the calculation of potency ratios. Two murine models were used to determine if these in vitro studies could predict activity in vivo. The relative efficacy in vivo also was expressed as a potency ratio, which was measured in terms of the number of bacteria in either homogenized kidney after intravenous challenge or an infected thigh muscle. For drugs with similar pharmacokinetics, the potency in vivo could be predicted from the value in vitro. However, for drugs with concentration curves in serum of different shapes, the potency in vivo varied from the value in vitro. A more prolonged course of drug in serum, which yielded a flatter concentration curve, appeared to be associated with greater activity in vivo.

Animals↗