Effect of vitamin C on neutrophil function after high-intensity exercise.

High-intensity exercise leads to an increased risk of upper respiratory tract infections in athletes, which had been related to an exercise-induced impairment of neutrophil function. In this study, several indices of neutrophil function were analysed before and after a biathlon and the effect of oral vitamin C on neutrophil function was determined. Six athletes took 2 g vitamin C daily for 1 week prior to a biathlon and four athletes did not take any supplementation. Neutrophil phagocytosis was analysed by fluorescence microscopy and flow cytometry. Cytosolic calcium kinetics were assessed fluorometrically and neutrophil bactericidal ability was assessed by fluorescence microscopy. Reactive oxygen production was analysed by flow cytometry. Catecholamines were analysed by high-performance liquid chromatography. After high-intensity exercise there were significant reductions in the number of phagocytosed Escherichia coli per neutrophil and in neutrophil bactericidal ability. There was a significant exercise-dependent increase of catecholamines. There was no difference between the two groups of athletes. These results do not support the concept that vitamin C supplementation corrects neutrophil dysfunction after strenuous exercise.

The effect of fosfomycin on neutrophil function.

Fosfomycin (cis-1,2-epoxypropyl phosphonic acid) is a cell wall synthesis-inhibiting antibiotic. We investigated the effect of fosfomycin on several indices of neutrophil function. Neutrophil phagocytosis was analysed by flow cytometry. Cytosolic calcium kinetics were assessed fluorometrically and neutrophil bactericidal ability was assessed by fluorescence microscopy. Intracellular reactive oxygen intermediate (ROI) production was analysed by flow cytometry and extracellular ROI by cytochrome c reductase assay. After fosfomycin incubation, phagocytosis was unaffected as assessed by the FACS assay. Fosfomycin incubation resulted in enhanced bactericidal ability, in increased intracellular calcium concentrations, elevated extracellular ROI production and decreased chemotaxis but it did not affect intracellular ROI production and chemokinesis.

Assessment of neutrophil function in patients with septic shock: comparison of methods.

Patients with septic shock are shown to have decreased neutrophil phagocytic function by multiple assays, and their assessment by whole-blood assays (fluorescence-activated cell sorter analysis) correlates with assays requiring isolated neutrophils (microscopic and spectrophotometric assays). For patients with similar underlying conditions but without septic shock, this correlation does not occur.

Osteomyelitis of the hip joint associated with systemic cat-scratch disease in an adult.

Reported here is the case of a 29-year-old male with cervical lymphadenopathy, fever and weight loss, followed by acute painful osteomyelitis of the left hip joint due to cat-scratch disease. The diagnosis was established by detection of IgG antibodies to Bartonella henselae in serum and histologic examination of a lymph node including a positive polymerase chain reaction test. Treatment consisted of clarithromycin and cefotiam for 2 weeks. Four weeks after discharge, all of the patient's symptoms had completely resolved. Magnetic resonance imaging of the left hip joint showed marked regression of bone inflammation 4 months later and normalization after 8 months. Cat-scratch disease should be considered in the differential diagnosis of osteomyelitis in an adult, especially when lymphadenitis is present.

[Neuraminidase inhibitors in therapy of influenza]. / Neuraminidasehemmer in der Therapie der Influenza.

Neuraminidase promotes influenza virus release from infected cells and facilitates virus spread within the respiratory tract. Several specific inhibitors of these enzyme have been developed. Zanamivir and oseltamivir are the nowadays available neuraminidase inhibitors. In contrast to amantadine and rimantadine, which target the M2 protein of influenza A, they inhibit the replication of both influenza A and B. Zanamivir is delivered by inhalation because of its low oral bioavailability. Oseltamivir can be administered orally. Early treatment reduces the severity and duration of illness and associated complications. These drugs are not effective at afebrile, mild courses, or if the influenza symptoms have existed already for more than 2 days. They are not effective against other respiratory viruses. For an optimal usage of the neuraminidase inhibitors a rapid and reliable diagnosis is necessary. The clinical diagnosis is sufficient only in proven epidemics. An increased availability of sensitive and specifically diagnostical tests is necessary for individual therapy decisions. The influenza vaccination is the most effective measure against influenza.