Apoptotic Cell-Derived CD14(+) Microparticles Promote the Phagocytic Activity of Neutrophilic Precursor Cells in the Phagocytosis of Apoptotic Cells.

Membranous CD14 is crucial in the phagocytic activity of neutrophils. However, the role of CD14(+) microparticles (MPs) derived from apoptotic neutrophils (apo-MP) during the phagocytic process is not clear. All trans-retinoic acid (ATRA) induces acute promyelocytic leukemic NB4 cells along granulocytic differentiation. In this study, we investigated the role of CD14(+)apo-MP in the cell-cell interaction during the phagocytic process of apoptotic cells by viable ATRA-NB4 cells. We firstly demonstrate that CD14 expression and phagocytic activity of NB4 cells were upregulated simultaneously after ATRA treatment in a time-dependent manner, and both were significantly enhanced via concurrent lipopolysaccharide treatment. The phagocytic activity of ATRA-NB4 cells and lipopolysaccharide-treated ATRA-NB4 cells were both significantly attenuated by pre-treating cells with an antibody specific to either CD14 or TLR4. Further flow cytometric analysis demonstrates that apoptotic ATRA-NB4 cells release CD14(+)apo-MP in an idarubicin dosage-dependent manner. Both CD14 expression and the phagocytic activity of viable ATRA-NB4 cells were significantly enhanced after incubation with apo-MP harvested from apoptotic ATRA-NB4 cells, and the apo-MP-enhanced phagocytic activity was significantly attenuated by pre-treating apo-MP with an anti-CD14 antibody before incubation with viable cells. We conclude that CD14(+)apo-MP derived from apoptotic ATRA-NB4 cells promotes the phagocytic activity of viable ATRA-NB4 cells in engulfing apoptotic cells.

Total knee replacement for patients with severe hemophilic arthropathy in Taiwan: A nationwide population-based retrospective study.

BACKGROUND: Total knee replacement (TKR) surgery is a treatment option for advanced hemophilic arthropathy. Due to its rarity and complexity, previous reports could only demonstrate the results of single-site studies including few cases. This population-based study aimed to investigate the major epidemiological characteristics, mean consumption of coagulation factors, length of hospital stays, complications, and failure rate of primary TKR for severe hemophilia patients in Taiwan. METHODS: A cohort of 996 hemophilia patients registered between 1995 and 2011 was included, and 103 primary TKRs were performed on 75 patients. Unilateral TKR was performed on 47 patients and bilateral TKRs on the remaining 28 patients, including 12 simultaneous and 16 staged surgeries. The mean age at surgery was 32.3 years (range, 17.3-55.7), and the mean follow-up duration was 77.9 months (range, 2.3-176.8). RESULTS: Failure was noted in 8 patients (8.5%) at mean 32.8 months (range, 2.3-95) after surgery. Four patients revealed aseptic loosening, whereas infection in 4. The 10-year prosthesis survivorship was 88.6%. For patients receiving unilateral TKR, the mean length of hospital stay was 15 days (range, 7-32). The mean cost of factor supplement was United States Dollar (USD) 43 543 with a mean 4-unit packed red blood cells transfusion (range, 0-38). The total admission cost was USD 48 326 (range, USD 4165-262 619). CONCLUSION: The prevalence of TKA for hemophilia patients was 7.5% in Taiwan. The mean hospital stay was 14 days, and the 10-year prosthesis survivorship was 88.6%. The mean daily factor usage was decreased from 235.7 units preoperatively to 202.1 units postoperatively. In comparison with the staged-bilateral TKRs, the simultaneous procedures significantly reduced the mean total cost from USD 101 923 to USD 61 587 (p = 0.023). Therefore, in terms of cost-effectiveness, bilateral simultaneous TKR is more preferable than staged procedures.

CX3CL1(+) Microparticles-Induced MFG-E8 Enhances Apoptotic Cell Clearance by Alveolar Macrophages.

During the resolution phase of acute lung injury, apoptotic cells release CX3CL1 as a "find-me" signal to attract alveolar macrophage transmigration toward apoptotic cells for phagocytosis. However, it is still not clear whether CX3CL1 has pro-phagocytic activity on alveolar macrophage. In this study, we investigated the role of apoptotic NB4 cells-derived CX3CL1(+) microparticles (apo-MP) on the phagocytic activity of NR8383 cells. We demonstrate that exogenous CX3CL1 and apo-MP enhanced the phagocytic activity of NR8383 cells in a CX3 CR1-dependent manner. The apo-MP-enhanced phagocytic activity on NR8383 was attenuated when apo-MP and NR8383 cells were pre-treated with anti-CX3CL1 antibodies and anti-CX3CR1 antibody, respectively, before incubating both for phagocytic assay. Further studies demonstrate that exogenous CX3CL1 and apo-MP also enhanced NR8383 cells in their surface expression and release of MFG-E8 in a CX3CR1 dependent manner. The enhanced phagocytic activity of CX3CL1-treated NR8383 cells was attenuated when NR8383 cells were pre-treated with an anti-MFG-E8 antibody before CX3CL1 treatment. We conclude that apoptotic cell-derived CX3CL1(+) microparticles enhance the phagocytic activity of NR8383 cells by up-regulating their MFG-E8 as a bridge molecule, and these contribute to the formation of phagocytic synapses between apoptotic cells and alveolar macrophages for the subsequent phagocytic clearance of apoptotic cells.

Early clinical exposure improves medical students' recognition of the need for professionalism and interprofessional collaboration.

BACKGROUND: Medical students in Taiwan start their clerkship in their fifth year. A lack of early clinical exposure can mean they have a lack of medical professionalism and collaborative practice. This study investigates whether early engagement in hospital-based clinical practice could improve their understanding of these requirements. METHODS: From 2017 to 2019, a total of 59 medical students at the end of their third year joined a 2-week summer camp at the hospital. Every participant was assigned to work with one patient and they accompanied this patient throughout their hospital course. The students were also asked to interview other medical professionals within the hospital and to write up interview reports. In addition, they had to complete pre- and postcamp questionnaires which included 10 questions to evaluate their recognition of professionalism, doctor-patient relationships, and interprofessional collaboration. Answers to the questions were all rated using a 5-score Likert scale. RESULTS: The total postcamp Likert scores were significantly increased after the 2-week training camp compared with the precourse scores (pre- vs postcourse: 44.08 ± 0.45 vs 46.66 ± 0.33, p < 0.001). In addition, the students' recognition of medical professionalism, the importance of communication with patients, and their respect for other medical professionals were significantly improved after the 2-week training. CONCLUSION: Our data showed that early clinical exposure through a preclerkship summer camp can help medical students improve their recognition of medical professionalism and interprofessional collaboration.

Role-play of real patients improves the clinical performance of medical students.

BACKGROUND: This study aimed to evaluate whether the role-play (RP) of real patients by medical students as part of interactive clinical reasoning training can improve medical students' clinical performance. METHODS: A total of 26 medical students volunteered to portray real patients within this program and were treated as the RP group while the other 72 students as the non-RP group. In the interactive morning meeting, the medical students practiced how to approach the RP student as if they were encountering a real patient. All students were evaluated by mini-clinical evaluation exercises (mini-CEX) before and after this training program. RESULTS: We found that all students had an increased total mini-CEX score after 4-week training, especially for interviewing skills. Notably, after training, the RP students had significantly elevated total mini-CEX scores (51.23 ± 1.06 vs 53.12 ± 1.11, p = 0.028), and for counselling (7.15 ± 0.14 vs 7.54 ± 0.18, p = 0.015) and overall clinical competence (7.27 ± 0.15 vs 7.65 ± 0.16, p = 0.030). In contrast, the non-RP students had lower scores compared with the RP group, as revealed by both the pre- and post-training tests. Moreover, their mini-CEX scores were not improved after training. CONCLUSION: Medical students who were motivated to RP real patients had better performance scores than those who did not. In addition, RP can enhance their counselling skills and clinical competences.

Primary bone marrow lymphoma: A hematological emergency in adults with fever of unknown origin.

Primary bone marrow lymphoma (PBML) represents non-Hodgkin lymphoma (NHL) that primarily arises in the bone marrow (BM) without lymphadenopathy. This condition has various definitions and can be masked by prolonged fever, leading to delayed diagnosis. We aimed to identify clinical features and risk indicators of PBML. We enrolled 269 adults with fever of unknown origin (FUO) who underwent a BM study for potential PBML. Thirty patients were diagnosed with PBML (26 and 4 patients in the training and validation cohort, respectively), and 20 patients (67%) showed initial manifestation of hemophagocytic lymphohistiocytosis (HLH). Among PBML patients in the training cohort, their median overall survival is short (8 days), with pneumonia being the most common direct cause of early mortality, followed by life-threatening HLH. Despite extremely poor prognoses, some B-cell PBML patients who survived 30 days after BM studies achieved long-term survival with rituximab-based treatment. To assist general practitioners in early PBML diagnosis when approaching adults with naïve FUO, we identified several risk indicators, including elevated serum alkaline-phosphate levels, lowered serum immunoglobulin-G levels, cytopenia in ≥2 lineages, and peripheral blood leukoerythroblastosis. Our recently published scoring system, which can predict hematological BM disease in FUO adults, showed excellent ability in recognizing PBML early, with high sensitivity and specificity. We conclude that PBML is a specific "clinical" phenotype of NHL; moreover, we have identified diagnostic clues for early identification of FUO adults with underlying PBML, which should be considered a hematological emergency once suspected in any adult with FUO.

Peer-assisted learning model enhances clinical clerk's procedural skills.

BACKGROUND: Failure to transfer procedural skills learned in a laboratory to the bedside is commonly due to a lack of peer support/stimulation. A digital platform (Facebook) allows new clinical clerks to share experiences and tips that help augment their procedural skills in a peer-assisted learning/teaching method. This study aims to investigate the effectiveness of the innovation of using the digital platform to support the transfer of laboratory-trained procedural skills in the clinical units. METHODS: Volunteer clinical clerks (n = 44) were enrolled into the peer-assisted learning (PAL) group, which was characterized by the peer-assisted learning of procedural skills during their final 3-month clinical clerkship block. Other clerks (n = 51) did not join the procedural skills-specific Facebook group and served as the self-directed learning regular group. The participants in both the PAL and regular groups completed pre- and post-intervention self-assessments for general self-assessed efficiency ratings (GSER) and skills specific self-assessed efficiency ratings (SSSER) for performing vein puncture, intravenous (IV) catheter and nasogastric (NG) tube insertion. Finally, all clerks received the post-intervention 3-station Objective Structured Clinical Skills Examination (OSCE) to test their proficiency for the abovementioned three procedural skills. RESULTS: Higher cumulative numbers of vein punctures, IV catheter insertions and NG tube insertions at the bedside were carried out by the PAL group than the regular group. A greater improvement in GSERs and SSSERs for medical procedures was found in the PAL group than in the regular group. The PAL group obtained higher procedural skills scores in the post-intervention OSCEs than the regular group. CONCLUSION: Our study suggested that the implementation of a procedural skill-specific digital platform effectively helps clerks to transfer laboratory-trained procedural skills into the clinical units. In comparison with the regular self-directed learning group, the peer-assisted learning characteristics of Facebook give additional benefits to the PAL group by enhancing their procedural skills.

Voluntary attendance of small-group brainstorming tutoring courses intensify new clerk's "excellence in clinical care": a pilot study.

BACKGROUND: Clerkship provides a unique way of transferring the knowledge and skills gathered during medical school's curriculum into real-ward clinical care environment. The annual program evaluation has indicated that the training of clerks in diagnostic and clinical reasoning skills needed to be enhanced. Recently, "clinical excellence" program have been promoted in our institution to augment the excellence in clinical care of new clerks. Current study aims to evaluate whether this pilot program improve the "clinical excellence" of new clerks. METHODS: In a pilot study, groups of new clerks in years 2013 and 2014 voluntarily attended either a small-group brainstorming course or a didactic classroom tutoring courses as part of their 3-month internal medicine clinical rotation block. A third group of new clerks did not join either of the above courses and this group served as the control group. Pre-block/post-block self-assessment and post-block 5-station mini-Objective Subjective Clinical Examinations (OSCEs) were used to evaluate the effectiveness of these two additional courses that trained diagnostic and clinical reasoning skills. RESULTS: Overtime, the percentages of new clerks that attended voluntarily either the small-group brainstorming or classroom tutoring courses were increased. Higher post-block self-assessed diagnostic and clinical reasoning skill scores were found among individuals who attended the small-group brainstorming courses compared to either the didactic group or the control group. In a corresponding manner, the small-group brainstorming group obtained higher summary OSCEdiag and OSCEreason scores than either the didactic group or control group. For all basic images/laboratory OSCE stations, the individual diagnostic skill (OSCEdiag) scores of the small-group brainstorming group were higher than those of the didactic group. By way of contrast, only the clinical reasoning skill (OSCEreason) scores of the basic electrocardiogram and complete blood count + biochemistry OSCE station of thesmall-group brainstorming group were higher than those of the didactic group. Among the small-group brainstorming group, clerks with higher cumulative learning hours (>30-h) had significant higher OSCEdiag and OSCEreason scores (>400) than those with less cumulative learning hours. CONCLUSION: Our pilot study provides a successful example of the use of a small-group tutoring courses for augmenting the diagnostic and clinical reasoning skills of new clerks. The positive results obtained during the initial 2-year long pilot "clinical excellence" program have encouraged the formal implementation of this course as part of the clerkship curriculum.

Serum pentraxin-3 and tumor necrosis factor-like weak inducer of apoptosis (TWEAK) predict severity of infections in acute decompensated cirrhotic patients.

BACKGROUND: Pentraxin-3 (PTX3) and soluble tumor necrosis factor (TNF)-like weak inducer of apoptosis (sTWEAK) are new candidate prognostic markers for comorbidities and mortality in various inflammatory diseases. Acute decompensation of cirrhosis is characterized by acute exacerbation of chronic systemic inflammation. Recently, increased circulating PTX3 levels have been reported in nonalcoholic steatohepatitis patients and positively correlated with disease severity. This study aims to explore serum PTX3/sTWEAK levels and their relationship with clinical outcomes in cirrhotic patients with acute decompensation. METHODS: We analyzed serum PTX3/sTWEAK levels in relation to inhospital and 3-month new clinical events and survivals in cirrhotic patients with acute decompensation. RESULTS: During admission, serum PTX3/sTWEAK levels were significantly higher in acute decompensated cirrhotic patients than controls and positively correlated with protein-energy wasting (PEW), new infections, long hospital stays, high medical costs, and high mortality. During a 3-month follow-up, acute decompensated cirrhotic patients with high serum PTX3/sTWEAK levels had more episodes of unplanned readmission and high 3-month mortality. On multivariate analysis, high PTX3/sTWEAK levels and PEW were independent risk factors for high mortality. CONCLUSION: High serum PTX3/sTWEAK levels and PEW are common in cirrhotic patients with acute decompensation. As compared with low serum PTX3 and sTWEAK cases, cirrhotic patients with high serum PTX3/sTWEAK levels a have higher probability of new severe infections, severe sepsis, septic shock, type 1 hepatorenal syndrome, in-hospital, and 3-month follow-up mortalities. Therefore, high serum PTX3/sTWEAK levels on hospital admission predict disease severity and case fatality in cirrhotic patients with acute decompensation.

Risk of hemophagocytic lymphohistiocytosis in adults with fevers of unknown origin: the clinical utility of a new scoring system on early detection.

The diagnosis of hemophagocytic lymphohistiocytosis (HLH) is delayed by most physicians. This study aimed to identify early parameters and suitable scoring systems for the risk of HLH. Clinical and laboratory data collected ≤3 days after admission were defined as early parameters and used to calculate the number of HLH-2004 criteria met and bone marrow (BM) score. Between January 2006 and February 2016, 233 immunocompetent adults with naïve fever of unknown origin who underwent a BM study were enrolled to mimic patients at risk of HLH and randomly assigned into the developmental or validation cohort. Hemophagocytic lymphohistiocytosis was finally diagnosed in 47 patients, with non-Hodgkin lymphoma as the major etiology (51.1%). Upon admission, four-fifths of patients who developed subsequent HLH fulfilled ≤3 of 8 HLH-2004 criteria, and 6 early parameters were independent predictors of HLH: anemia (hemoglobin < 10 g/dL), thrombocytopenia (platelet count < 100 × 103 /µL), leukoerythroblastosis, hyperbilirubinemia (total bilirubin > 2 × upper normal limit), hyperferritinemia (ferritin > 1000 ng/mL), and splenomegaly. Compared with the HLH criteria met upon admission, the BM score was an independent predictor (odds ratio = 1.621; 95% confidence interval, 1.355-1.940) with excellent discrimination (area under the receiver operating characteristic curve = 0.920; 95% confidence interval, 0.883-0.958). The sensitivity and specificity for a BM score cutoff of 10 points were 95% and 75%, respectively. When approaching immunocompetent adults with a continuously high fever, the BM score at initial admission assists with early identification of patients at risk of HLH.

Decision-tree algorithm for optimized hematopoietic progenitor cell-based predictions in peripheral blood stem cell mobilization.

BACKGROUND: Enumerating hematopoietic progenitor cells (HPCs) by using an automated hematology analyzer is a rapid, inexpensive, and simple method for predicting a successful harvest compared with enumerating circulating CD34+ cells. However, the optimal HPC cutoff count and the indicating factors to be considered for improved predicting have not yet been determined. STUDY DESIGN AND METHODS: Between 2007 and 2012, a total of 189 consecutive patients who proceeded to peripheral blood stem cell (PBSC) harvesting were retrospectively recruited. Baseline characteristics were analyzed to identify the risk factors for a failed harvest, which were defined as less than 2 × 10(6) CD34+ cells/kg. Variables identified by multivariate logistic regression and correlation analysis for predicting a successful harvest were subjected to classification and regression tree (CART) analysis. RESULTS: PBSCs were successfully harvested in 154 (81.5%) patients. An age of at least 60 years, a diagnosis of a solid tumor, at least five prior chemotherapy cycles, prior radiotherapy, and mobilization with granulocyte-colony-stimulating factor alone or high-dose cyclophosphamide were independent baseline predictors of poor mobilization. In CART analysis, patients with zero to two host risk factors and either higher HPC (≥28 × 10(6) /L) or mononuclear cell (MNC; ≥3.5 × 10(9) /L) counts were categorized as good mobilizers and their harvest success rate was 92.3%. By contrast, 30.3% of harvests were adequate in the patients with three to five host risk factors and lower HPC and MNC counts. CONCLUSION: A CART algorithm incorporating host predictors and HPC and MNC counts improves predictions in a successful harvest and might reduce the necessity of monitoring peripheral CD34+ cells.

A model of four hierarchical levels to train Chinese residents' teaching skills for "practice-based learning and improvement" competency.

OBJECTIVES: The current study focused on validating a protocol for training and auditing the resident's practice-based learning and improvement (PBLI) and quality improvement (QI) competencies for primary care. METHODS: Twelve second-year (R2), 12 first-year (R1) and 12 postgraduate year-1 residents were enrolled into group A, B and C, respectively, as trainees. After three training protocols had been completed, a writing test, self-assessed questionnaire and mini-OSTE and end-of-rotation assessment were used in auditing the PBLI competency, performance and teaching ability of trainees. RESULTS: Baseline expert-assessed PBLI and QI knowledge application tool writing scores were low for the R1 and R2 residents. After three training protocols, PBLI and QI proficiencies, performance and teaching abilities were improved to similar levels cross the three training levels of residents based on the expert-assessed writing test-audited assessments and on the faculty and standardized clerk-assessed end-of-rotation-/mini-OSTE-audited assessments. CONCLUSION: The different four-level hierarchical protocols used to teach group A, B and C were equally beneficial and fitted their needs; namely the different levels of the trainees. Specifically, each level was able to augment their PBLI and QI proficiency. This educational intervention helps medical institutions to train residents as PBLI instructors.

Self- and rater-assessed effectiveness of "thinking-aloud" and "regular" morning report to intensify young physicians' clinical skills.

BACKGROUND: This study compared the effects of the "thinking aloud" (TA) morning report (MR), which is characterized by sequential and interactive case discussion by all participants, with "regular" MR for clinical skill training of young physicians. METHODS: Between February 2011 and February 2014, young physicians [including postgraduate year-1 (PGY1) residents, interns, and clerks) from our hospital were sequentially enrolled and followed for 3 months. The self- and rater-assessed educational values of two MR models for building up clinical skills of young physicians were compared. RESULTS: The junior (intern and clerk) attendees had higher self-assessed educational values scores and reported post-training application frequency of skills trained by TA MR compared with the senior (PGY1 resident) attendees. Higher average and percentage of increased overall rater-assessed OSCE scores were noted among the regular MR senior attendees and TA MR junior attendees than in their corresponding control groups (regular MR junior attendees and TA MR senior attendees). Interestingly, regular MRs provided additional beneficial effects for establishing the "professionalism, consulting skills and organization efficiency" aspects of clinical skills of senior/junior attendees. Moreover, senior and junior attendees benefited the most by participating in seven sessions of regular MR and TA MR each month, respectively. CONCLUSION: TA MR effectively trains junior attendees in basic clinical skills, whereas regular MR enhances senior attendees' "work reports, professionalism, organizational efficiency, skills in dealing with controversial and professional issues." Undoubtedly, all elements of the two MR models should be integrated together to ensure patient safety and good discipline among young physicians.

No increase of JAK2 46/1 haplotype frequency in essential thrombocythemia with CALR mutations: Functional effect of the haplotype limited to allele with JAK2V617F mutation but not CALR mutation.

The true frequency of the JAK2 46/1 haplotype in patients of myeloproliferative neoplasms (MPN) with CALR mutations was unknown. Totally 187 MPN cases with diagnosis of polycythemia vera (PV) and essential thrombocythemia (ET) were recruited. The frequency of 46/1 haplotype was significantly higher in JAK2V617F-positive PV (51%, p < 0.001) and ET (41%, p = 0.005) compared to normal controls. The exact location of JAK2V617F mutation was located at the cis-46/1 haplotype in 86.4% (32/37) PV patients and 87.5% (28/32) ET patients, respectively. Among the 51 patients of ET without JAK2V617F mutation, 38 (75%) patients harbored CALR mutations and 3 patients had MPL mutation. The frequency of 46/1 haplotype in the 38 ET patients with CALR mutations was 27%, which is not significantly different from that of normal control (p value = 0.879). Compared to non-46/1 haplotype, the presence of 46/1 haplotype had a trend to have higher white blood cell count in JAK2V617F-mutated PV and ET patients but not in CALR-mutated ET. We conclude that the 46/1 haplotype could have functioning effect but only in the context of JAK2V617F mutation.

A "bone marrow score" for predicting hematological disease in immunocompetent patients with fevers of unknown origin.

Delayed diagnosis of hematological malignancies in immunocompetent patients with fever of unknown origin (FUO) remains an exhausting challenge for non-hematologist physicians. This retrospective cohort study aimed to establish a scoring system, "bone marrow (BM) score", to identify FUO patients who require early bone marrow biopsy (BMB) to diagnose hematological disease. Two cohorts, comprising 85 (training) and 20 (validation) eligible immunocompetent patients, with FUOs diagnosed between January 1, 2006 and July 31, 2013, underwent BMBs and were enrolled in the study. Demographic, laboratory, imaging, diagnostic, and outcome data were collected and retrospectively analyzed. Factors associated with hematological etiologies diagnosed using BMBs in the training cohort were identified and scored according to the relative hazards. These were further validated using the validation cohort. For the training cohort, 29 of 85 (34.1%) patients had hematological etiologies diagnosed using BMB. Seven factors significantly predicted the diagnostic yield of hematological diseases in the BM and were scored, with the 6 points for leucoerythroblastic changes in peripheral blood smears, 5.5 for elevated ferritin level (>1000 ng/mL), 4 for splenomegaly, 2 for thrombocytopenia, 1.5 for each of elevated lactate dehydrogenase levels and anemia, and 1 for neutropenia. When the cut-off value of the scoring system was set to 6, its sensitivity and specificity to diagnose hematological diseases in the BM of immunocompetent FUO patients were 93% and 58%, respectively. For the validation cohort, 7 of 20 (35%) patients had hematological disease, and all had BM scores higher than the cut-off, with the sensitivity and specificity at 100% and 77%, respectively. As immunocompetent FUO patients with hematological disease have poor prognoses, the "BM score" is valuable for non-hematologist physicians to identify immunocompetent FUO patients requiring early BMB.

Role of CX3CL1 in the chemotactic migration of all-trans retinoic acid-treated acute promyelocytic leukemic cells toward apoptotic cells.

BACKGROUND: Phagocytic clearance of apoptotic neutrophils by tissue macrophages is a crucial component in the resolution phase of acute inflammation. However, the number of tissue macrophages is low and not likely to cope satisfactorily with the excess number of dying neutrophils. Although recent studies have reported that neutrophils are able to engulf apoptotic neutrophils, the mechanisms by which living neutrophils are attracted to apoptotic neutrophils are poorly defined. Increased amounts of CX3CL1 and microparticles (MPs) are rapidly released by apoptotic cells, and are involved in the chemoattraction of mononuclear phagocytes toward apoptotic cells. The current study investigated the role of CX3CL1 in the chemoattraction of all-trans retinoic acid (ATRA)-treated NB4 (ATRA-NB4) cells toward apoptotic cells. METHODS: Conditioning medium and MPs were harvested from apoptotic ATRA-NB4 cell cultures to determine their effects on living ATRA-NB4 cells by transmigration assay and adhesion assay. The cytokine levels in the conditioning medium were determined by enzyme-linked immunosorbent assay. Expression of CX3CR1 (a receptor of CX3CL1) on ATRA-NB4 cells was determined by flow cytometric analysis. RESULTS: ATRA-NB4 cells transmigrated toward the apoptotic ATRA-NB4 cells, and this chemoattraction was partially inhibited when the CX3CR1 on ATRA-NB4 cells was blocked by its specific antibody. Both exogenous CX3CL1 and MPs released by apoptotic ATRA-NB4 cells were able to enhance the chemoattraction of ATRA-NB4 cells toward apoptotic cells or the adhesion of ATRA-NB4 cells to endothelial cells. CX3CL1 was expressed on the surface of MPs, and blocking this CX3CL1 with its specific antibody was able to partially inhibit the chemoattractive property of MPs. CONCLUSION: CX3CL1, in either the free or MP form, is released rapidly by apoptotic ATRA-NB4 cells after induction of apoptosis to mediate the chemoattraction of living ATRA-NB4 cells toward apoptotic cells.

Increased risks of endotracheal tube cuff colonization after prolonged intubation.

Mechanical ventilation using endotracheal tube (ETT) intubation is crucial in saving life but may also cause ventilator-associated pneumonia resulting in morbidity and mortality. The purpose of this study was to examine the effects of intubation duration on pathogen colonization rates of ETT cuff region, and its association with the subsequent re-intubation and tracheostomy. We enrolled 92 patients who were successfully weaned from ventilator and were extubated within 20 days of intubation duration. Patients were divided into Group I and II based on intubation for 1-9 days and 10-20 days, respectively. Pathogen colonization over ETT cuff region and extra-cuff region (including sputum and ETT aspirates) were assessed. As compared to Group I patients, Group II patients had a significant higher pathogen colonization rate (100% vs. 69.2%; P < 0.001) in the ETT cuff samples, but not in the extra-cuff samples (92.6% vs. 84.8%; P = 0.442). Further studies demonstrated that there was no difference between Group I and II patients in the percentages of patients with the same pathogen over both the cuff and extra-cuff samples (35.5% vs. 30.8%; P = 0.925), suggesting that the increased pathogen colonization rate over the ETT cuff region was least likely from the extra-cuff region. In addition, the results showed that longer intubation was also associated with increased tracheostomy rate from 9.3% to 28.9% for Group I and Group II respectively (P = 0.025). We conclude that longer intubation has a higher pathogen colonization rate over the ETT cuff region in patients receiving mechanical ventilation support; longer intubation also increases the trend of receiving re-intubation and tracheostomy. Our findings indicate that it is crucial to remove ETT as soon as possible and perform pathogen culture over the ETT cuff regions immediately after extubation.

Serial changes in plasma annexin A1 and cortisol levels in sepsis patients.

Annexin A1 (AnxA1), originally identified as a glucocorticoid-regulated protein, is an impor- tant endogenous anti-inflammatory mediator during the resolution phase of inflammation, and its cir- culating level has been rarely studied in sepsis patients. Glucocorticoid has been extensively used in treating patients with sepsis. However, it is unclear whether endogenous cortisol or exogenous glucocor- ticoid contributes to the regulation of AnxA1 levels in peripheral blood of sepsis patients. The aim of this study was to investigate: [1] serial changes over time in the plasma levels of AnxA1 and cortisol in sepsis patients; and [2] prognostic value of AnxA1 level in the survival of sepsis patients. Fifty-eight adult sepsis patients admitted to an intensive care unit (ICU) were enrolled. The plasma levels of cortisol and AnxA1 were determined by specific enzyme-link immunosorbent assay. Results show that the median daily levels of cortisol at the 1st, 3rd, 5th and 7th day after admission to ICU were signifi- cantly elevated over the cortisol level of the control subjects. However, the AnxA1 level was elevated in only thirty-three patients (56%) over the observation period. There was no significant correlation between cortisol levels and AnxA1 levels. Further analysis indicated that steroid treatment resulted in significant elevation of the cortisol level over time, but did not affect the AnxA1 level. AnxA1 levels were also not statistically different between surviving and non-surviving patients. In conclusions, the circu- lating level of AnxA1 is elevated in a subgroup of sepsis patients, and the AnxA1 level does not correlate with the cortisol level in the peripheral blood of sepsis patients.

CX3CL1(+) microparticles mediate the chemoattraction of alveolar macrophages toward apoptotic acute promyelocytic leukemic cells.

BACKGROUND/AIMS: During the resolution phase of inflammation, release of "find-me" signals by apoptotic cells is crucial in the chemoattraction of macrophages toward apoptotic cells for subsequent phagocytosis, in which microparticles derived from apoptotic cells (apo-MPs) are involved. A recent study reports that CX3CL1 is released from apoptotic cells to stimulate macrophages chemotaxis. In this study, we investigated the role of CX3CL1 in the apo-MPs in the cell-cell interaction between alveolar macrophage NR8383 cells and apoptotic all-trans retinoic acid-treated NB4 (ATRA-NB4) cells. METHODS/RESULTS: Apoptotic ATRA-NB4 cells and their conditioning medium (CM) enhanced the chemoattraction of NR8383 cells as well as their phagocytosis activity in engulfing apoptotic ATRA-NB4 cells. The levels of CX3CL1(+) apo-MPs and CX3CL1 were rapidly elevated in the CM of ATRA-NB4 cell culture after induction of apoptosis. Both exogenous CX3CL1 and apo-MPs enhanced the transmigration of NR8383 cells toward apoptotic ATRA-NB4 cells. This pro-transmigratory activity was able to be partially inhibited either by blocking the CX3CR1 (CX3CL1 receptor) of NR8383 cells with its specific antibody or by blocking the surface CX3CL1 of apo-MPs with its specific antibody before incubating these apo-MPs with NR8383 cells. CONCLUSION: CX3CL1(+) apo-MPs released by apoptotic cells mediate the chemotactic transmigration of alveolar macrophages.

Plasma levels in sepsis patients of annexin A1, lipoxin A4, macrophage inflammatory protein-3a, and neutrophil gelatinase-associated lipocalin.

BACKGROUND: The relationship between the various cytokine responses that occur during sepsis remains controversial. Emerging evidence indicates that the proinflammatory and anti-inflammatory responses are regulated simultaneously from the beginning of sepsis. However, the roles of the novel anti-inflammatory mediators annexin (Anx)A1 and lipoxin (LX)A4 and the proinflammatory cytokines neutrophil gelatinase-associated lipocalin (NGAL) and macrophage inflammatory protein (MIP)-3a have been studied. METHODS: In this study, the plasma levels of AnxA1, LXA4, NGAL, MIP-3a, interleukin (IL)-8 and IL-6 in patients with sepsis were determined on admission to the intensive care unit. The patients were classified into survivors and non-survivors based on their outcome on day 28. RESULTS: AnxA1 and LXA4 levels were decreased in sepsis patients compared with control patients, whereas the levels of the proinflammatory cytokines MIP-3a, NGAL, IL-8, and IL-6 were elevated. Furthermore, a significantly higher level of MIP-3a was detected in nonsurviving patients compared with surviving patients (p < 0.05), whereas there were no significant differences between these two groups for the levels of the other mediators. Correlation analysis demonstrated that only NGAL level was closely correlated with the level of IL-6. Univariate analysis indicated that the levels of MIP-3a and IL-8 were independent factors associated with patient survival, but this was not confirmed by the multivariate analysis. CONCLUSION: AnxA1 and LXA4 plasma levels were found to be decreased in sepsis patients, whereas the levels of MIP-3a and NGAL were found to be elevated. This warrants further study in order to determine the clinical implications of these changes.