Short-course antibiotic therapy for infections with a single causative pathogen

Studies evaluating short-course therapy have focused on prevalent infections with demonstrable aetiology. Metaanalyses of clinical trials demonstrate that uncomplicated acute otitis media in children can be successfully treated with a 5-day course of cefuroxime axetil. In the treatment of tonsillopharyngitis, 4 - 5-day courses of oral cephalosporins compared favourably with the standard 10-day penicillin V regimen. The clinical cure rate and the bacteriological eradication rate were both significantly higher for cephalosporins than for penicillin V. Bacteriological failure rates for cephalosporins were about half those for penicillin. In studies on acute bacterial exacerbations of chronic bronchitis, no difference in the clinical cure rates or relapse rates was found between short-course therapy using cephalosporins and standard courses. The short courses had the advantage of improved gastrointestinal tolerance compared with longer durations of treatment. The results suggest that new short-course dosing regimens are viable and may be favourable in terms of increased tolerability, reduction in healthcare costs, enhanced patient compliance and the control of the development of antibiotic resistance.

Stimulation of cellular sphingomyelin import by the chemokine connective tissue-activating peptide III

The selective import of phospholipids into cells could be mediated by proteins secreted from the cells into the extracellular compartment. We observed that the supernatants obtained from suspensions of thrombin-activated platelets stimulated the exchange of pyrene (py)-labeled sphingomyelin between lipid vesicles in vitro. The proteins with sphingomyelin transfer activity were purified and identified as the chemokine connective tissue-activating peptide III (CTAP-III) and platelet basic protein. Isolated CTAP-III stimulated the exchange of py-sphingomyelin between lipid vesicles but did not affect the translocations of py-labeled phosphatidylcholine and phosphatidylethanolamine. CTAP-III rapidly increased the transfer of py-sphingomyelin from low density lipoproteins into peripheral blood lymphocytes, other immune cells, and fibroblasts. In the presence of heparin, CTAP-III was unable to insert sphingomyelin into the peripheral blood lymphocytes. The activation energy of the py-sphingomyelin transfer suggested that the translocation proceeded entirely in a hydrophobic environment. [(3)H]Sphingomyelin transferred to the cells by CTAP-III was hydrolyzed to [(3)H]ceramide and [(3)H]sphingosine after activation with tumor necrosis factor alpha. The generation of the [(3)H]sphingolipid messengers was catalyzed by acid sphingomyelinase. Our results identify CTAP-III as the first mediator of the selective (endocytosis-independent) cellular import of sphingomyelin allowing the paracrine modulation of the sphingolipid signaling.

Influence of fluconazole on phagocytosis, oxidative burst and killing activity of human phagocytes. Using a flow cytometric method with whole blood

OBJECTIVES

The aim of this study was to investigate the influence of fluconazole, an antimycotic on phagocytosis, oxidative burst and killing activity of phagocytes in human whole blood with Candida albicans as a test strain using a flow cytometric method.

METHODS

Candida albicans was stained with Calcein AM, a greenfluorescent dye from Bioprobes (Molecular Probes, Inc., P.O. Box 22010, Eugene, OR 97402-0469, USA). To measure phagocytosis and burst activity diluted monoclonal antibody (CD-13-R-PE, Molecular Probes, Inc., P.O. Box 22010, Eugene, OR 97402-0469, USA) attaching at the surface of granulocytes and monocytes was added as well as Dihydroethidium solution (Molecular Probes, Inc., P.O. Box 22010, Eugene, OR 97402-0469, USA) which changes into red fluorescent Ethidium by oxidation when killing activity takes place. With Ethidium-Homodimer-1-solution (Molecular Probes, Inc., P.O. Box 22010, Eugene, OR 97402-0469, USA) killing activity can be observed. Three different tests, one incubating the Candida for 1- 4 hrs in advance, another incubating whole blood for 1 h, and the third incubating neither yeast nor blood, and a combined main test were carried out. Measurement of phagocytosis, burst- and killing activtiy was performed with a flow cytometric method (Coulter Company, type: Epics-Profile II).

RESULTS

Three different concentrations of fluconazole (5, 20 and 100 microg/ml) show neither decreasing nor increasing influence on phagocytosis and burst activity, irrespective of whether yeasts or phagocytes had been incubated with fluconazole in advance or not. Also after incubating the drug with phagocytes for 1 h, neither an increase nor a decrease of killing activity was observed. A significant increase was, however, found with increasing incubation time of yeasts and fluconazole. - The minimum concentration of fluconazole, just enough to show a significant increase of the killing rate was 1 microg/ml after 3hrs of incubation. No further significant increase was detected when the concentration exceeded 5 microg/ml.

CONCLUSION

1 h incubation of human phagocytes with fluconazole does not have any significant influence on cellular activities. After advanced incubation of Candida a corresponding increase of the intracellular killing rate in phagocytes occurs, probably due to changes of the cytomorphology of yeasts.

Activation of ERK1/2 and cPLA(2) by the p55 TNF receptor occurs independently of FAN

The generation of proinflammatory eicosanoids in response to tumor necrosis factor (TNF) involves the activation of cytosolic phospholipase A(2) (cPLA(2)), presumably by phosphorylation through extracellular signal-regulated kinases (ERK). Earlier results had suggested that a pathway involving the p55 TNF receptor (TNF-R55), neutral sphingomyelinase (N-SMase), and c-Raf-1 activates ERK and cPLA(2). We have previously shown that a cytoplasmic region of TNF-R55 distinct from the death domain regulates the activation of N-SMase through binding of the adapter protein FAN. Analysis of embryonal fibroblasts from FAN knockout mice revealed that TNF-induced activation of both ERK and cPLA(2) occurs without involvement of FAN. Furthermore, we provide evidence that the TNF-dependent activation of ERK and cPLA(2) requires the intact death domain of TNF-R55. Finally, we demonstrate that in murine fibroblasts cPLA(2) is phosphorylated in response to TNF solely by ERK, but not by p38 mitogen-activated protein kinase, suggesting a signaling pathway from TNF-R55 via the death domain to ERK and cPLA(2).

Short-course antibiotic treatment of 4782 culture-proven cases of group A streptococcal tonsillopharyngitis and incidence of poststreptococcal sequelae

A large-scale study with a 1-year follow-up was performed to compare 10 days of penicillin V with a short-course treatment (5 days) of other oral antibiotics in the treatment of group A beta-hemolytic streptococcus (GABHS) tonsillopharyngitis, to evaluate the efficacy and the incidence of poststreptococcal sequelae. The clinical response rates after completion of therapy were 94.5% in the 5-day group and 93.4% in the penicillin group (P<.001, equivalence test). The GABHS eradication rates were 83.3% in the 5-day group and 84.4% in the penicillin group (P=.022, equivalence test). Poststreptococcal sequelae were rare (5 patients) and did not occur in the context of this study. The efficacy of 5-day antibiotic regimens was equivalent to 10 days of penicillin V, but resolution of clinical symptoms was faster in the 5-day group (P<.001, Fisher's exact test). Recurrent tonsillopharyngitis occurs more frequently after treatment with penicillin (P=.03, Fisher's exact test).

An analysis of an inflammatory bowel disease practice in an urban community hospital

OBJECTIVES

To review an individual community gastroenterologist's experience with inflammatory bowel disease (IBD). The aspects studied were distribution of disease, need for hospital admission, immunosuppressants, systemic steroids, and surgery and its indications. The incidence of cancer was also reviewed.

PATIENTS AND METHODS

The charts of all IBD patients (n=373) seen between 1993 and 1996 by an individual gastroenterologist in an urban community hospital were reviewed for the aforementioned information. Patients seen during this period may have been diagnosed with IBD before or during the period of 1993 to 1996.

RESULTS

Of the 373 patients, 219 had Crohn's disease (CD) and 154 had ulcerative colitis (UC). The most common age of onset for both groups was 20 to 29 years. Distal UC and distal Crohn's colitis patients rarely required surgery, hospitalization, systemic steroids or immunosuppressants. Eighty per cent of patients with small bowel CD and 51% of those with ileocolonic CD required at least one operation. Of the UC patients, 10.4% required surgery. Of the UC patients undergoing surveillance for cancer, none developed cancer but one developed significant dysplasia.

CONCLUSIONS

In both CD and UC the site of the inflammation plays a major role in determining the need for hospitalization, surgery, systemic steroids and immunosuppressants. Distal UC, the most common form of UC in this group of patients, is a very benign disease. Of all forms of IBD, small bowel CD had the greatest need for hospitalization, surgery and systemic steroids.

Simultaneous cytofluorometric measurement of phagocytosis, burst production and killing of human phagocytes using Candida albicans and Staphylococcus aureus as target organisms

OBJECTIVE

Polymorphonuclear leukocytes (PMN) play a central role in the elimination of most extracellular pathogens, and an impairment of their functions predisposes an individual towards local and systemic bacterial and fungal infections. Here we describe a rapid and easy-to-perform cytofluorometric assay for investigation of PMN activity using Candida albicans and Staphylococcus aureus as target organisms.

METHODS

Phagocytes were stained with anti-CD13-RPE antibody, and microorganisms were stained with calcein-AM. Oxidative burst production was measured by oxidation of dihydroethidium. The percentage of killed target organisms after ingestion was determined by staining with ethidium-homodimer-1 after lysis of human cells. The dyes and procedures used in this method were chosen after comparison of different stains and cell preparation techniques described in previous assays.

RESULTS

Concerning phagocytosis, the percentages of active phagocytes and of ingested microorganisms were determined. Furthermore, the method allowed measurement of the resulting percentage of PMNs producing respiratory burst, and of the percentage of killed microorganisms. We minimized artifactual changes, which might have been the reason for the difficulties and conflicting results of other cytofluorometric methods.

CONCLUSIONS

The described method provides a new whole blood cytofluorometric assay, which combines rapid and simple handling with high reproducibility of results obtained by investigation of PMN activity using Candida albicans and Staphylococcus aureus as target organisms.

The management of bacterial infections of the upper respiratory tract in children: pharyngitis and otitis media

Despite changes in the activities of infectious microorganisms, particularly variations in their prevalences in different parts of the body, in clinically defined diseases, and in their susceptibilities to antibiotics, the established first-line agents for the empiric treatment of otitis media and pharyngitis are still valid. Nevertheless, a number of the newer antimicrobials have become valuable as second- and third-line medications when the first-choice drugs fail or are contraindicated. In terms of fundamental principles, the question of whether pharyngitis in children warrants routine antibiotic therapy remains unresolved; in practical terms, antibiotic treatment should be considered routinely.