[Five-year analysis of extrahospital consumption of betalactams in Spain]. / Cinco años de evolución del consumo extrahospitalario de betalactámicos en España (1993-1997).

We carried out a qualitative and quantitative study to determine extrahospital consumption of both broad-spectrum penicillins and cephalosporins in Spain in the period 1993-1997. Penicillins were the most consumed group, followed by macrolides and cephalosporins. Units and value (ptas.) of penicillins and cephalosporins during these five years show interannual variations. Nevertheless, monthly analysis of consumption for both groups showed a stable tendency, with peaks in winter months and drops in the summer. Both penicillins (54.38%) and cephalosporins (27.71%) were prescribed mainly for upper respiratory tract infections. Men received more penicillins and cephalosporins than women (51.02% and 55.09%). Children under 11 years were the main group for consumption of both types of antibiotic, while patients aged 55-64 years were the group with the least consumption.

[Comparison of the in vitro and in vivo effects of meropenem and ciprofloxacin on the morphology of Escherichia coli and Staphylococcus aureus]. / Comparación del efecto in vitro e in vivo de meropenem y ciprofloxacino sobre la morfología de Escherichia coli y Staphylococcus aureus.

In the treatment of infections, subinhibitory concentrations are commonly present and induce a wide range of effects. Some of these effects have been reported to improve the efficacy of these compounds. One of these effects, the change of the bacterial morphology, was assayed in this study both in vitro and in vivo, and their results were compared. Two antimicrobial agents (meropenem and ciprofloxacin) and two standard Gram-positive and Gram-negative strains (S. aureus y E. coli) were used. The methods employed included the in vitro exposure of microorganisms on Mueller-Hinton agar plates, and the in vivo intraperitoneal infection model in mice. With all the sub-MICs tested, the in vitro results showed that meropenem induced the formation of round cells (spheroplasts) on E. coli, while ciprofloxacin produced filaments. With S. aureus, the two antimicrobial agents induced the formation of cellular aggregates (clusters) with a diameter greater than 1 mm. The in vivo results confirmed those observed in vitro, but to a lesser extent. These results agree with those expected in relation with the mechanisms of action of each drug, and could be important in order to prevent a lost in efficacy when the levels of the drug are below the MIC.

Somatostatin binding to a fresh rat astrocyte-enriched suspension.

Since there are conflicting reports regarding the effects of somatostatin (SS) on cyclic AMP levels in astrocytes derived from rat cerebral cortex and, to date, the SS binding to mature astrocytes is unknown, the present study has determined SS binding and its effect on cyclic AMP accumulation in a fresh astrocyte-rich suspension from rat cerebral cortex. 125I-Tyr11-SS binding was inhibited by SS in a dose-dependent manner. The Scatchard analysis of binding data was linear and yielded a dissociation constant of 0.95 +/- 0.15 nM with a maximal binding capacity of 122 +/- 13 fmol/mg protein. Vasoactive intestinal peptide (VIP) stimulated cyclic AMP accumulation up to 2.3 times above the basal levels whereas SS had no effect. This effect at any of the VIP concentrations. Likewise, SS did not inhibit the stimulation of cyclic AMP accumulation provoked by other effectors such as isoproterenol and forskolin. In view of our results and those of other authors, SS receptor localized in astrocytes must be able to couple with signal transduction systems other than adenylate cyclase, in order to carry out its biological actions in the cell.