Clinical Trial of Amikacin in the Treatment of Pyelonephritis in Children

Twenty-three patients with pyelonephritis, twenty-one of them children, were treated with twice-daily intramuscular injections of amikacin, a new aminoglycoside antibiotic. Adults were given 250 mg doses every 12 hours; children were given 5 mg/kg/day divided into two doses 12 hours apart. Treatment continued for ten days. Pre-treatment cultures and sensitivity tests revealed E. coli to be the responsible organism in fourteen cases, with Proteus mirabilis, Klebsiella aerobacter, Proteus rettgeri and Pseudomonas aeruginosa in the remaining cases. Eighteen of the twenty-three patients responded satisfactorily, with pathogens eradicated and clinical signs and symptoms resolved. Post-treatment urine cultures were performed up to 30 days. No adverse drug effects were noted clinically nor in pre-and post-treatment laboratory tests of renal, hepatic and hematopoietic function.

Antibacterial resistance of community-acquired respiratory tract pathogens recovered from patients in Latin America: results from the PROTEKT surveillance study (1999-2000)

PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) is a global surveillance study established in 1999 to monitor antibacterial resistance of respiratory tract organisms. Thirteen centers from Argentina, Brazil and Mexico participated during 1999-2000; they collected 1806 isolates (Streptococcus pneumoniae 518, Haemophilus influenzae 520, Moraxella catarrhalis 140, Staphylococcus aureus 351, S. pyogenes 277). Overall, 218 (42.1%) of the S. pneumoniae isolates had reduced susceptibility to penicillin, 79 (15.3%) were penicillin-resistant and 79 (15.3%) were erythromycin-resistant. Mexico had the highest prevalence of penicillin (76.5%) and erythromycin (31.2%) resistance. Of 77 erythromycin-resistant S. pneumoniae tested for resistance genotype, 43 possessed mef(A), 33 possessed erm(B) and 1 possessed both erm(B) and mef(A) mechanism. All S. pneumoniae isolates were fully susceptible to telithromycin, linezolid, teicoplanin and vancomycin. Among H. influenzae isolates, 88 (16.9%) produced beta-lactamase, ranging from 11% (Brazil) to 24.5% (Mexico). Among M. catarrhalis isolates, 138 (98.6%) produced beta-lactamase. Twenty-four (8.7%) of the S. pyogenes isolates were erythromycin-resistant; resistance being attributable to mefA (n=18), ermTR (n=5) and ermB (n=1). All H. influenzae, M. catarrhalis and S. pyogenes were fully susceptible to telithromycin. Methicillin resistance was found in 26.5% of the S. aureus isolates (Argentina 15%; Mexico 20%; Brazil 31.3%). Telithromycin was effective against 97.7% of methicillin-susceptible isolates. PROTEKT confirms that antibacterial resistance is an emerging problem in Latin America. The previously reported high levels of pneumococcal resistance to the beta-lactam and macrolides were exceeded. New agents that do not induce resistance or that exert low selective pressure, e.g. telithromycin, are essential to safeguard future antibacterial efficacy.

Hypertonic saline and pentoxifylline prevent lung injury and bacterial translocation after hemorrhagic shock

Previous reports have shown beneficial effects of pentoxifylline (PTX) and hypertonic saline (HS) in the treatment of hemorrhagic shock. We compared the effects of these solutions to those of conventional lactated Ringer's (LR) treatment on bacterial translocation (BT), lung injury and total and differential cell count in the bronchoalveolar lavage fluid (BAL) after hemorrhagic shock. Rats (280-330 g) were bled to a MAP of 35 mmHg for 1 h and then randomized into 4 groups: LR (3x shed blood); HS (7,5% NaCl, 4 mL/kg); LR+PTX (25 mg/kg) and SHAM (no shock, no treatment). Additionally, total shed blood was reinfused. At 24 h lung injury was analyzed by a pathologist blinded to the groups, and a score was calculated. BT was determined by microbiological cultures of mesenteric lymph node complex. BAL was performed on a separate set of animals that received the same treatments. Lung score was significantly higher in LR group (11.5+/-1.4) as compared to HS (6.8+/-0.9), and PTX treated animals (7.2+/-0.9). The percentage of neutrophils in the BAL of LR animals (15.8%) was also significantly higher as compared with HS (5.25%) and PTX groups (9.72%). BT was noted in 50% of rats for LR group, 30% for PTX, 10% for HS and 0% for sham group. HS and PTX reduced BT and lung injury after hemorrhage. Attenuation of lung injury could be the result of less neutrophil infiltration into the lungs of HS and PTX treated animals. LR resuscitation caused pronounced lung injury and BT.

Evaluation of the in vitro activity of 9 antimicrobials against bacterial strains isolated from patients in intensive care units in brazil: MYSTIC Antimicrobial Surveillance Program

Multi-resistant bacterial strains are increasingly prevalent in hospital environments. Bacterial resistance is an important problem, especially for practitioners in intensive care units (ICUs) because of the selective pressure on the prevalent bacteria in these environments. The MYSTIC (Meropenem Yearly Susceptibility Test Information Collection) study has been monitoring the performance of carbapenems and other antibiotics in different hospitals for at least 3 years. The in vitro activities of meropenem, imipenem, ceftazidime, cefepime, cefotaxime, ciprofloxacin, piperacilin/tazobactam, gentamicin, and tobramycin were compared against 452 recent clinical aerobic isolates. The isolates consisted of 19 species of Gram-negative bacteria (n=290) including K. pneumoniae (n=49), E. coli (n=48), A. baumannii (n=47), Enterobacter spp. (n=41), and P. aeruginosa (n=33) and 9 species of Gram-positive bacteria (n=162) including Staphylococcus aureus (n=63), Enterococcus faecalis (n=22), Streptococcus pneumoniae (n=22) and coagulase negative Staphylococci (n=21). All isolates were collected from ICU patients. Minimal inhibitory concentrations (MICs) were determined by Etest methodology, using standardized and controlled procedures. Meropenem and imipenem showed the lowest MIC(90) for all species tested. Gram-negative isolates showed the following overall resistance percentages to the other 7 drugs: tobramycin (43.1%), cefotaxime (38.6%), gentamicin (34.1%), ceftazidime (31.7%), ciprofloxacin (25.5%), piperacillin/tazobactam (26.9%), and cefepime (18.6%). Carbapenems were the most active drugs overall and only P. aeruginosa presented some degree of resistance (18.2%). We also evaluated the production of extended spectrum beta-lactamase (ESBL) among all Enterobacteriaceae members (n=176) by Etest/ESBL strip. ESBL production was detected in 51 strains (29.0%). Among them, Klebsiella pneumoniae was the most prevalent at 59.2%, followed by Enterobacter spp. (19.5%) and E. coli (14.6%). The high level of resistance against several antimicrobials and the alarming rate of ESBL production may restrict therapeutic choice to the carbapenems in this selected group of patients.

[Evaluation of polymorphonuclear neutrophils in moderate malnutrition]

PURPOSE

To evaluate the phagocytic function of polymorphonuclear neutrophils in moderate malnutrition.

METHODS

The phagocytic function of neutrophils obtained through peripheral blood sampling of twenty two children with moderate malnutrition without infections was analyzed. The results were compared to a group of twenty well nourished children matched for age (two to five years old). The phagocytic function was assessed by the ingestion of zymosan particles and nitro blue tetrazolium reduction among 200 cells.

RESULTS

The mean number of zymosan particles ingested by neutrophils incubated with homologous human serum and autologous human serum were 18, 41 and 46 in the malnutrition group compared to 20, 57 and 63 in the well nourished group. The spontaneous and stimulated reduction of nitro blue tetrazolium was 6 and 11 in the malnourished patients, respectively, and 12 and 17 in the well nourished group.

CONCLUSION

A decrease in the process of ingestion and digestion during phagocytosis occurs in malnourished patients.

[Study of the susceptibility of Staphylococcus sp. and Enterococcus sp. to teicoplanin and vancomycin]

PURPOSE

The study was performed in order to evaluate the susceptibility of Enterococcus and Staphylococcus to teicoplanin and vancomycin.

METHODS

150 Enterococcus strains and 450 Staphylococcus strains (298 Staphylococcus aureus and 152 negative coagulase strains) isolated in three Brazilian hospitals were studied. The MICs were determined using teicoplanin and vancomycin E Test strips. The range of the antimicrobial concentration in each strip went from 256 mcg/mL to 0.016 mcg/mL. Diffusion tests using disks impregnated with 10 mcg of teicoplanin and 30 mcg of vancomycin were also performed.

RESULTS

All the 298 Staphylococcus aureus strains were susceptible to the two antimicrobials. Three of the 152 negative coagulase strains presented intermediate susceptibility to teicoplanin (MICs between 8 and 16 mcg/mL). Four of the 150 Enterococcus strains presented intermediate susceptibility to vancomycin but were totally susceptible to teicoplanin.

CONCLUSION

According to these results teicoplanin and vancomycin are good therapeutical options in the treatment of staphylococcal and enterococcal infections.

Multiple-dose pharmacokinetics of the antimalarial drug Fansimef (pyrimethamine + sulfadoxine + mefloquine) in healthy subjects

Fansimef is a new antimalarial combination containing pyrimethamine, sulfadoxine and mefloquine in the weight proportions 1 + 20 + 10. It has been designed to fight plasmodia resistant to the presently used antimalarial drugs and to counter the development of new resistant forms of the parasites. In the present study tablets containing 25 mg pyrimethamine, 500 mg sulfadoxine and 250 mg mefloquine were used. Six Brazilian volunteers received a loading dose of 2 tablets followed by 20 maintenance doses of 1 tablet at a dosage interval of 7 days. The pharmacokinetic evaluation of each of the three components was based on the assumption of an open linear two-compartment model. After the last maintenance dose the following kinetic parameters were determined for pyrimethamine, sulfadoxine and mefloquine, respectively: elimination half-life = 123, 179 and 550 h; volume of distribution in the postdistributive phase = 2.5, 0.15 and 18.6 1 X kg-1, and total systemic clearance = 14.0, 0.64 and 24.0 ml X h-1 X kg-1. All these values agree fairly well with those measured in previous single-dose kinetic studies. At steady state, Cmin values of each of the three components generally showed small variations. No unexpected accumulation of any of the three components was observed, indicating that induction or inhibition of metabolic enzymes did not occur during the trial.

Agrammatism in a case-inflected language: comprehension of agent-object relations

Yugoslav agrammatic aphasics and normal control subjects were tested for comprehension of agent-object relations in a series of simple Serbo-Croatian sentences consisting of two nouns (N) and a transitive action verb (V). The availability of nominative and accusative case inflections and a semantic contrast was systematically varied across sentences. Sentences were also varied with respect to the two sequences NVN and VNN. An analysis of subjects' agent-object assignments yielded the following results: While Broca's aphasics did show some sensitivity to case inflections, their ability to process such cues was greatly impaired relative to normal subjects, for whom morphological cues were almost completely deterministic. To a lesser degree, Broca's aphasics were impaired in their ability to employ a strategy of "choose the first noun as agent" when case inflections and semantic contrasts were not available. While Broca's aphasics showed no impairment in their ability to exploit semantic contrasts for agent-object assignment, there was no absolute compensatory increase in the degree to which they relied on semantic cues. Differences in word sequence had no effect on agent--object assignment in Broca's aphasics. Finally, Broca's aphasic frequently responded unsystematically when cues to agent--object relations occurred in isolation or in competition with one another, but when there was a convergence of cues their performance approached that of normal subjects. This result was interpreted in terms of an accessing hypothesis.

Multiple-dose kinetic study of mefloquine in healthy male volunteers

250 mg mefloquine was administered orally once a week for 21 consecutive weeks to 5 volunteers. Blood samples were collected just before administration of the next dose, and the unchanged drug and its metabolite, Ro 21-5104, were measured in the plasma. The mean plasma levels minima in individual subjects measured at steady state were for mefloquine between 0.56 and 1.25 micrograms/ml, and for the metabolite between 1.47 and 5.55 micrograms/ml. The corresponding metabolite to mefloquine ratios ranged between 2.3 and 8.6. The half-life of mefloquine determined at the end of the trial agreed fairly well with values measured in single dose kinetics. This suggests that induction or inhibition of the metabolizing enzymes did not occur during the period of administration.

[Comparative study of the lepromin reaction performed on medical students and on a control group]

The lepromin test was studied in 64 medical students and in a control group consisted of 40 patients from the orthopedic clinic. Both groups matched with respect to age and sex, but differed with regard to socio-economical conditions. The Fernandez reaction showed low frequency of positive results in both groups: 10% in the first group and 5,6% in the second one. This difference was not significant. The Mitsuda reaction showed high frequency of positive results: 98,4% in the medical students and 85,0% in the control group. This difference was significant. The authors discuss the factors that might have caused the high positivity of the lepromin test among the medical students.

[Comparative study of the intradermal reaction performed with whole lepromin and ultrasonic-treated lepromin in normal subjects]

A comparative study on the Fernandez and on the Mitsuda reaction was made in 104 normal people employing whole and sonicated lepromin. Both types of lepromin can induce a good early reaction, and there was no significant difference in the results of the Fernandez reaction. The sonicated lepromin, though it contains all of the components of the original preparation, gives weaker late skin reactions. The results of the Mitsuda reaction were statistically significant.