Antimicrobial susceptibilities and serotypes of invasive Streptococcus pneumoniae strains in Switzerland.

In 1993 and 1994, 10 microbiological laboratories in Switzerland collected 351 strains of Streptococcus pneumoniae from invasive infections. Susceptibilities to the main representatives of the chemical classes were as follows: penicillin, 93%; chloramphenicol, 92%; erythromycin, 94%; sulfamethoxazole-trimethoprim, 86%; tetracycline, 92%; vancomycin, 100%. Forty-three strains showed resistance to one agent, and 35 strains showed resistance to two or more antimicrobial agents simultaneously; i.

The interaction of macrophages and bacteria: a comparative study of the induction of tumoricidal activity and of reactive nitrogen intermediates.

The abilities of various bacteria to induce in a pure population of bone marrow-derived mononuclear phagocytes (BMM phi) tumoricidal activity and/or the generation of reactive nitrogen intermediates (RNI) were comparatively assessed. Interaction of BMM phi with bacteria led to expression of these functional activities, indicating that the organisms were recognized as foreign. As the majority of bacteria elicited in BMM phi either tumoricidal activity (that is maintained for days) or the production of RNI, measured by the release of nitrite (that is short-lived), it appears that the two functions are under separate control.

Role of topology in bioenergetics of sodium transport in complex epithelia.

There has been some controversy as to whether in sodium-transporting epithelia (e.g., frog skin, toad urinary bladder) the Na-O2 ratio is independent of the net rate of transepithelial sodium transport or remains constant over a wide range of transport rates.

Compartmental analysis of the Na+ flux ratio with application to data on frog skin epidermis.

In this computer simulation study, the role of the topological factor on the Na+ influx/backflux (efflux) ratio in multicompartmental model membranes with active Na+ transport has been investigated. As in the classical "three compartment model", so also in multicompartment models with series order of compartments (series topology), the flux ratios are time-independent. By contrast, in models with series-parallel order of compartments (series-parallel topology), inclusive shunt pathways, the flux ratios are time-dependent.

Sodium transport and distribution of electrolytes in frog skin.

The objective of this study on frog skin was to examine correlations between transepidermal active Na-transport and intracellular [Na]c, [K]c, [Cl]c homeostasis. Isolated, whole skins, and "split skins" were used in measurements of short-circuit current (SCC) and open skin potential (PD). Water and ion contents were estimated on split skins.