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Although blood cultures (BCs) are the “gold standard” for detecting bacteremia, the utility of BCs in patients with community-acquired pneumonia (CAP) is controversial. This study describes the proportion of patients with CAP and afebrile bacteremia and identifies the clinical characteristics predicting the necessity for BCs in patients who are afebrile.

Older cats (>10 years) with FLUTD (Feline Lower Urinary Tract Disease) symptoms are often affected by urinary tract infections. In most of these cats organ diseases (e.g. chronic renal failure, diabetes mellitus) or iatrogenic factors (immunosuppressive drugs, indwelling catheter) are found that clearly predispose cats to this kind of infection. From a diagnostic point of view, urinalysis and urine culture are the most important tools in detecting bacteriuria. The microbiological spectrum is thereby comparable to that found in dogs, revealing Escherichia ( E. ) coli but also Staphylococcus spp. and Enterococcus spp./ Streptococcus spp. Antibiotic therapy should be based on the results of susceptibility testing. If this kind of information is not available, drug selection has to be decided on an empirical basis unless it is a complicated urinary tract infection. Preferred antibiotics should have a high renal excretion rate and thus ensure therapeutically effective drug levels in the urine. In this respect, the fluoroquinolones belong to the group of appropriate drugs to be used in cats. The relevance of therapeutical drug concentrations achievable in the urine is discussed for the example of marbofloxacin, a third-generation fluoroquinolone. New pharmacokinetic data showed that marbofloxacin concentrations of ≥2µg/ml are maintained in the urine of healthy cats for 72 and 103 hours after administration of 2 and 4mg/kg BW s.c., respectively.

The mycorrhizal activity of spruce in a mixed-wood forest was monitored over 1 year by measuring biochemical characters in fine roots of six canopy trees and of a regrowth stand. The concentration of adenosine 5'-triphosphate (ATP), a measure of living biomass, showed two peaks per year, one at bud break and one after main shoot growth. The concentration of storage polysaccharides in mycorrhizae showed the same cycles even more pronouncedly. It is proposed that these changes reflect growth and senescence of mycorrhizae and that the timing of the cycles is controlled by translocation of assimilates from the shoot. Differences between mycorrhizae collected from canopy trees and the regrowth stand were small and not significant. Characters known to be related to fungal activity of the mycorrhizal symbiosis (concentration of trehalose, glucose uptake, respiration) also varied little among the six canopy trees. Large differences among fine-root samples from different canopy trees, however, were detected in the concentrations of ATP and storage polysaccharides, measures which seemed to be physiologically integrated within trees. If low concentrations in roots precede losses of foliage from trees, these two symptoms could be used as early indicators of growth decline in individual spruce trees.

On the basis of the reviews presented in this issue, the ecological significance of mycorrhizal symbioses is discussed. Mycorrhizas may have some importance in the acquisition of mineral nutrients during the productive phase of ecosystems in early stages of succession, but their main role is played during the protective phase of ecosystems in the final stages of succession when most resources are incorporated into biomass. In these successional stages, mycorrhizas short-circuit nutrient cycles by directly reacquiring nutrients in organic form from plant (and fungal) litter, and they may reallocate resources between different plant individuals, preventing loss of resources from the entire ecosystem.

Breathing at very low lung volumes might be affected by decreased expiratory airflow and air trapping. Our purpose was to detect expiratory flow limitation (EFL) and, as a consequence, intrinsic positive end-expiratory pressure (PEEPi) in grossly obese subjects (OS). Eight OS with a mean body mass index (BMI) of 44 ± 5 kg/m2and six age-matched normal-weight control subjects (CS) were studied in different body positions. Negative expiratory pressure (NEP) was used to determine EFL. In contrast to CS, EFL was found in two of eight OS in the upright position and in seven of eight OS in the supine position. Dynamic PEEPiand mean transdiaphragmatic pressure (mean Pdi) were measured in all six CS and in six of eight OS. In OS, PEEPiincreased from 0.14 ± 0.06 (SD) kPa in the upright position to 0.41 ± 0.11 kPa in the supine position (P< 0.05) and decreased to 0.20 ± 0.08 kPa in the right lateral position (P< 0.05, compared with supine), whereas, in CS, PEEPiwas significantly smaller (<0.05 kPa) in each position. In OS, mean Pdi in each position was significantly larger compared with CS. Mean Pdi increased from 1.02 ± 0.32 kPa in the upright position to 1.26 ± 0.17 kPa in the supine position (not significant) and decreased to 1.06 ± 0.26 kPa in the right lateral position (P< 0.05, compared with supine), whereas there were no significant changes in CS. We conclude that in OS1) tidal breathing can be affected by EFL and PEEPi;2) EFL and PEEPiare promoted by the supine posture; and 3) the increased diaphragmatic load in the supine position is, in part, related to PEEPi.