Neutrophil cannibalism – a back up when the macrophage clearance system is insufficient

BACKGROUND: During a lipopolysaccharide-induced lung inflammation, a massive accumulation of neutrophils occurs, which is normally cleared by macrophage phagocytosis following neutrophil apoptosis. However, in cases of extensive apoptosis the normal clearance system may fail, resulting in extensive neutrophil secondary necrosis. The aim of this study was to explore the hypothesis that neutrophils, in areas of the lung with extensive cellular infiltration, contribute to clearance by phagocytosing apoptotic cells and/or cell debris derived from secondary necrosis. METHODS: Intranasal lipopolysaccharide administration was used to induce lung inflammation in mice. The animals were sacrificed at seven time points following administration, bronchoalveolar lavage was performed and tissue samples obtained. Electron microscopy and histochemistry was used to assess neutrophil phagocytosis. RESULTS: Electron microscopic studies revealed that phagocytosing neutrophils was common, at 24 h after LPS administration almost 50% of the total number of neutrophils contained phagosomes, and the engulfed material was mainly derived from other neutrophils. Histochemistry on bronchoalvolar lavage cells further showed phagocytosing neutrophils to be frequently occurring. CONCLUSION: Neutrophils are previously known to phagocytose invading pathogens and harmful particles. However, this study demonstrates that neutrophils are also able to engulf apoptotic neutrophils or cell debris resulting from secondary necrosis of neutrophils. Neutrophils may thereby contribute to clearance and resolution of inflammation, thus acting as a back up system in situations when the macrophage clearance system is insufficient and/or overwhelmed

Effect of Dexamethasone Implant on Subfoveal Choroidal Thickness in Early Period in Vitrectomized Eyes with Diabetic Macular Edema

Aim. To investigate the change in subfoveal choroidal thickness (SFCT) in vitrectomized eyes with intravitreal dexamethasone (IVD) implant injection for the treatment of diabetic macular edema (DME). Method. In this prospective and controlled study, the vitrectomized eyes of diabetic patients were included. The study group (Group 1) was formed by diabetic vitrectomized eyes with DME. The control group (Group 2) was formed by diabetic vitrectomized eyes without DME. Only one intravitreal IVD implant was injected into the eyes in Group 1. In the first, second, and fourth months, choroidal layers were measured by optical coherence tomography and complete ophthalmologic examinations were performed for all cases. Results. Ninety-six eyes of 96 cases were included in the study. There were 48 eyes of 48 different patients in each group. After IVD injection, statistically significant improvement was observed in the best corrected visual acuity in Group 1. The mean SFCT in eyes with DME was statistically significantly thinner (p < 0.01) and thinness became more pronounced during the four-month follow-up period after IVD implant injection (p < 0.01). Conclusion. In the presence of DME in vitrectomized eyes, the thinness of the SFCT may become evident after dexamethasone implant injection

Effect of Dexamethasone Implant on Subfoveal Choroidal Thickness in Early Period in Vitrectomized Eyes with Diabetic Macular Edema

Aim. To investigate the change in subfoveal choroidal thickness (SFCT) in vitrectomized eyes with intravitreal dexamethasone (IVD) implant injection for the treatment of diabetic macular edema (DME). Method. In this prospective and controlled study, the vitrectomized eyes of diabetic patients were included. The study group (Group 1) was formed by diabetic vitrectomized eyes with DME. The control group (Group 2) was formed by diabetic vitrectomized eyes without DME. Only one intravitreal IVD implant was injected into the eyes in Group 1. In the first, second, and fourth months, choroidal layers were measured by optical coherence tomography and complete ophthalmologic examinations were performed for all cases. Results. Ninety-six eyes of 96 cases were included in the study. There were 48 eyes of 48 different patients in each group. After IVD injection, statistically significant improvement was observed in the best corrected visual acuity in Group 1. The mean SFCT in eyes with DME was statistically significantly thinner ( p  &lt; 0.01) and thinness became more pronounced during the four-month follow-up period after IVD implant injection ( p  &lt; 0.01). Conclusion. In the presence of DME in vitrectomized eyes, the thinness of the SFCT may become evident after dexamethasone implant injection.</jats:p

Evaluation of Children with Stenotrophomonas maltophilia Bacteremia

Introduction: Stenotrophomonas maltophilia (S. maltophilia) is a resistant gramnegative rod that can often cause serious infections, especially in patients with long hospital stays and using broad-spectrum antibiotics. In this study, clinical data, and mortality-related risk factors of patients with S. maltophilia bacteremia were evaluated. Materials and Methods: Patients with S. maltophilia bacteremia included in this study and evaluated retrospectively, when hospitalized between 2013 and 2018 in our pediatric wards and intensive care units. Results: A total of 67 patients had 100 S. maltophilia bacteremia in 70 different episodes. Sixty percent (n=40) of the cases were male and their median age were 9 months. Sixty-nine percent (n=46) of the cases were admitted in intensive care units. The most common comorbidity was malignancy. All bacteremias were healthcare associated, and 55% (n=55) were catheter-related. In the total of 70 episodes; 57% (n=37) of the patients had central venous catheters, 47% (n=33) were entubated. Fourty-seven percent (n=33) of the patients had broad spectrum antibiotic use over 14 days. In the blood cultures, 98% of S. maltophilia-producing strains were sensitive to trimethoprim-sulfamethoxazole. Ciprofloxacin and trimethoprim-sulfamethoxazole combination therapy had used for treatment. The mortality rate in the first 30 days was 16% (n=11). Mechanical ventilation was found to be significant (p<0.05) as a predisposing factor related to mortality. Conclusion: Stenotrophomonas maltophilia is the causative pathogen in healthcare associated bloodstream infections especially in intensive care unit. In our study, 69% of the cases were admitted in the intensive care unit and mechanical ventilation status increased mortality