Granulocyte colony‐stimulating factor (G‐CSF) has been shown to stimulate human neutrophil functions, both in vitro and in vivo. We examined the effects of G‐CSF administration on the surface expression of effector cell molecules on human neutrophils and monocytes. G‐CSF (50 μg/m2/d) was administered subcutaneously to five healthy volunteers once a day for 7 d. Venous blood was obtained immediately before and after the completion of G‐CSF administration and 1 week after the last G‐CSF administration. The surface expression of complement receptors (CR), Fc receptors for IgG (FcR) and cellular adhesion molecules on human neutrophils and monocytes were determined by indirect immunofluorescence using flow cytometry and monoclonal antibodies. The expression of CR1, CR3, FcRI and FcRII on neutrophils increased significantly after G‐CSF administration and then decreased after the last G‐CSF administration. The expression of human leucocyte adhesion molecule‐1 (LAM‐1) on neutrophils reflected the above expression. On the other hand, the administration of G‐CSF increased the expression of CR1, CR3, FcRI and FcRIII on monocytes. The expression of CR1, CR3 and FcRI on monocytes then decreased after the last G‐CSF administration, whereas the expression of FcRIII remained at an increased level. These findings indicate that G‐CSF administration modulates the expression of effector cell molecules on circulating monocytes as well as on neutrophils, resulting in enhanced defence against selected infections or in potentiation of the tumouricidal capacity of phagocytes in cancer patients.
For the purpose of nationwide surveillance of antimicrobial susceptibility of bacterial respiratory pathogens from patients in Japan, the Japanese Society of Chemotherapy (JSC) started a survey in 2006. From 2009, JSC continued the survey in collaboration with the Japanese Association for Infectious Diseases and the Japanese Society for Clinical Microbiology. The fourth-year survey was conducted during the period from January and April 2009 by the three societies. A total of 684 strains were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections. Susceptibility testing was evaluable with 635 strains (130 Staphylococcus aureus, 127 Streptococcus pneumoniae, 4 Streptococcus pyogenes, 123 Haemophilus influenzae, 70 Moraxella catarrhalis, 78 Klebsiella pneumoniae, and 103 Pseudomonas aeruginosa). A maximum of 45 antibacterial agents including 26 β-lactams (four penicillins, three penicillins in combination with β-lactamase inhibitors, four oral cephems, eight parenteral cephems, one monobactam, five carbapenems, and one penem), four aminoglycosides, four macrolides (including ketolide), one lincosamide, one tetracycline, two glycopeptides, six fluoroquinolones, and one oxazolidinone were used for the study. Analysis was conducted at the central reference laboratory according to the method recommended by the Clinical and Laboratory Standard Institute (CLSI). Incidence of methicillin-resistant S. aureus (MRSA) was as high as 58.5 %, and that of penicillin-intermediate and penicillin-resistant S. pneumoniae (PISP and PRSP) was 6.3 % and 0.0 %, respectively. Among H. influenzae, 21.1 % of them were found to be β-lactamase-non-producing ampicillin (ABPC)-intermediately resistant (BLNAI), 18.7 % to be β-lactamase-non-producing ABPC-resistant (BLNAR), and 5.7 % to be β-lactamase-producing ABPC-resistant (BLPAR) strains. A high frequency (76.5 %) of β-lactamase-producing strains has been suspected in Moraxella catarrhalis isolates. Four (3.2 %) extended-spectrum β-lactamase-producing K. pneumoniae were found among 126 strains. Four isolates (2.5 %) of P. aeruginosa were found to be metallo-β-lactamase-producing strains, including three (1.9 %) suspected multi-drug resistant strains showing resistance against imipenem, amikacin, and ciprofloxacin. Continuous national surveillance of the antimicrobial susceptibility of respiratory pathogens is crucial to monitor changing patterns of susceptibility and to be able to update treatment recommendations on a regular basis.
The leucocyte adhesion molecule-1 (LAM-1) is the human homologue of the murine peripheral lymph node homing receptor, MEL-14, and might play a crucial role in neutrophil localization at inflammatory sites. We have reported previously that recombinant human granulocyte colony-stimulating factor (rhG-CSF) stimulates or enhances several neutrophil functions in vivo, as well as in vitro. To further explore the possible role of G-CSF in inflammation we studied the effect of rhG-CSF on the surface expression of LAM-1 on human neutrophils, both in vitro and in vivo. The expression of LAM-1 by human neutrophils was investigated by indirect immunofluorescence using flow cytometry and monoclonal antibodies anti-Leu-8 and TQ1. A whole blood analysis was performed to minimize in vitro manipulation. Most circulating human neutrophils expressed LAM-1 on the cell surface. Brief exposure of neutrophils to rhG-CSF in vitro decreased the surface expression of LAM-1. rhG-CSF down-regulated neutrophil LAM-1 expression in a time- and dose-dependent manner. Neutrophils from healthy volunteers and from patients who were receiving rhG-CSF exhibited a decreased expression of LAM-1 after rhG-CSF administration, and the expression thereafter returned or overshot the pretreatment level after stopping rhG-CSF administration. These findings indicate that rhG-CSF down-regulates the surface expression of LAM-1 on human neutrophils in vivo, as well as in vitro, and G-CSF might participate in neutrophil-endothelial cell interaction in inflamed tissue.
To understand the gene expression of CAP18 (18-kDa cationic antibacterial protein), a member of cathelicidins, we evaluated mRNA and protein expression of CAP18 using human bone marrow cells and mature neutrophils. Northern blot analysis revealed that CAP18 mRNA was expressed more abundantly in bone marrow cells than mature neutrophils, whereas Western blot analysis indicated that CAP18 protein was more abundant in mature neutrophils than bone marrow cells. Consistent with this, in situ hybridization using bone marrow cells demonstrated that the expression of CAP18 mRNA was neutrophil lineage-specific and was observed primarily in myelocytes (G95%) with limited expression in more immature cells (promyelocytes) and mature cells (metamyelocytes, band cells, and segmented neutrophils). Furthermore, immunohistochemical study indicated that, coincident with the increase of CAP18 mRNA levels, CAP18-positive cells increased markedly at myelocyte stage, and the increased levels remained almost constant (G95%) in metamyelocytes, band cells, and segmented neutrophils, although the mRNA levels were remarkably reduced in these cells. Together these observations indicate that CAP18 gene transcription likely occurs lineageand stage-specifically at the myelocyte stage of neutrophil maturation in the bone marrow and results in the synthesis and cytoplasmic accumulation of CAP18, which is present in the subsequent stages of neutrophil maturation. J. Leukoc. Biol. 64: 845-852; 1998.
The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from patients in Japan, was conducted by Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases and Japanese Society for Clinical Microbiology in 2010. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period from January and April 2010 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical and Laboratory Standard Institutes using maximum 45 antibacterial agents. Susceptibility testing was evaluable with 954 strains (206 Staphylococcus aureus, 189 Streptococcus pneumoniae, 4 Streptococcus pyogenes, 182 Haemophilus influenzae, 74 Moraxella catarrhalis, 139 Klebsiella pneumoniae and 160 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was as high as 50.5%, and those of penicillin-intermediate and-resistant S. pneumoniae were 1.1% and 0.0%, respectively. Among H. influenzae, 17.6% of them were found to be b-lactamase-non-producing ampicillin (ABPC)-intermediately resistant, 33.5% to be b-lactamase-non-producing ABPC-resistant and 11.0% to be b-lac-tamase-producing ABPC-resistant strains. Extended spectrum b-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo b-lactamase were 2.9% and 0.6%, respectively. Continuous national surveillance of antimicrobial susceptibility of respiratory pathogens is crucial in order to monitor changing patterns of susceptibility and to be able to update treatment recommendations on a regular basis.
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