The recruitment of neutrophil granulocytes to sites of tissue injury is one of the earliest events during host defense. Several chemotactic cytokines belonging to the CXC subfamily of chemokines are thought to be implicated in this kind of response. Especially those CXC chemokines that are stored in blood platelets and become immediately released upon activation are likely to dominate neutrophil-dependent host defense at the onset of inflammation. The major platelet-derived CXC chemokines are the ␤-thromboglobulins and platelet factor 4 (PF-4), which are both released into the blood at micromolar concentrations. The availability as well as the functional activity of these mediators appear to be subject to tight control by diverse regulatory mechanisms. These include proteolytic processing of chemokine precursors, oligomer formation, and the differential usage of neutrophil-expressed receptors. Herein we review our work on early neutrophil regulation by PF-4, the ␤-thromboglobulin neutrophil-activating peptide 2 (NAP-2) and its major precursor connective tissueactivating peptide III (CTAP-III). We moreover propose a model to assess the contribution by either of these chemokines to coordinated recruitment and activation of neutrophils in response to acute tissue injury. J. Leukoc. Biol. 67: 471-478; 2000.

In this study we applied a polymerase chain reaction (PCR) assay for the detection and species-specific identification of mycobacteria to samples from patients with sarcoidosis and mycobacterial infections and from control patients. The PCR-technique is based on the amplification of mycobacterial DNA coding for 16S rRNA, which is present in all mycobacterial species, and on the additional sequencing of the PCR fragment to determine the species. Mycobacterial DNA could be detected in lung tissues and bronchoalveolar lavage cells from cases of tuberculosis and infections with atypical mycobacteria. On the other hand, mycobacterial DNA was amplified only in lung tissue from one patient with sarcoidosis. Twenty-three samples from patients with sarcoidosis were negative for mycobacterial DNA. From our results we conclude that the granulomatous lesions in sarcoidosis may not be due to mycobacterial infections.

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A polymerase chain reaction (PCR) assay for the rapid and species-specific diagnosis of mycobacterial infections in paraffin-embedded clinical specimens was developed using oligonucleotide primers to amplify a fragment of the DNA coding for the ribosomal 16S RNA of mycobacteria. The oligonucleotide primers amplified DNA from all 14 species of mycobacteria tested. By means of a reamplification protocol, as few as one to two mycobacteria could be detected in the presence of human DNA. The method of DNA isolation and amplification was applied on sections of routinely formalin-fixed and paraffin-embedded tissues. PCR for the beta-actin gene served as a control for successful DNA isolation. Mycobacterial DNA could be detected in cases of mycobacterial infections. The mycobacterial species was determined by additional sequencing of the PCR fragment. This PCR method may be a powerful tool for the diagnosis of mycobacterial infections from histopathological material and for the assessment of those mycobacteria that cannot readily be cultured, such as Mycobacterium leprae.

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